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Sample records for measured include ph

  1. 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.

  2. A solid-state pH sensor for nonaqueous media including ionic liquids.

    Science.gov (United States)

    Thompson, Brianna C; Winther-Jensen, Orawan; Winther-Jensen, Bjorn; MacFarlane, Douglas R

    2013-04-02

    We describe a solid state electrode structure based on a biologically derived proton-active redox center, riboflavin (RFN). The redox reaction of RFN is a pH-dependent process that requires no water. The electrode was fabricated using our previously described 'stuffing' method to entrap RFN into vapor phase polymerized poly(3,4-ethylenedioxythiophene). The electrode is shown to be capable of measuring the proton activity in the form of an effective pH over a range of different water contents including nonaqueous systems and ionic liquids (ILs). This demonstrates that the entrapment of the redox center facilitates direct electron communication with the polymer. This work provides a miniaturizable system to determine pH (effective) in nonaqueous systems as well as in ionic liquids. The ability to measure pH (effective) is an important step toward the ability to customize ILs with suitable pH (effective) for catalytic reactions and biotechnology applications such as protein preservation.

  3. 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.

  4. 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...

  5. 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...

  6. 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

  7. 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.

  8. 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...

  9. Evaluation of the 11CO2 positron emission tomographic method for measuring brain pH. I. pH changes measured in states of altered PCO2

    International Nuclear Information System (INIS)

    Buxton, R.B.; Alpert, N.M.; Babikian, V.; Weise, S.; Correia, J.A.; Ackerman, R.H.

    1987-01-01

    The 11 CO 2 method for measuring local brain pH with positron emission tomography (PET) has been experimentally evaluated, testing the adequacy of the kinetic model and the ability of the method to measure changes in brain pH. Plasma and tissue time/activity curves measured during and following continuous inhalation of 11 CO 2 were fit with a kinetic model that includes effects of tissue pH, blood flow, and fixation of CO 2 into compounds other than dissolved gas and bicarbonate ions. For each of ten dogs, brain pH was measured with PET at two values of PaCO 2 (range 21-67 mm Hg). The kinetic model fit the data well during both inhalation and washout of the label, with residual root mean square (RMS) deviations of the model from the measurements consistent with the statistical quality of the PET data. Brain pH calculated from the PET data shows a linear variation with log(PaCO 2 ). These results were in good agreement with previously reported measurements of brain pH, both in absolute value and in variation with PCO 2 . The interpretation of these pH values in normal and pathological states is discussed

  10. 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...

  11. Characterisation and deployment of an immobilised pH sensor spot towards surface ocean pH measurements.

    Science.gov (United States)

    Clarke, Jennifer S; Achterberg, Eric P; Rérolle, Victoire M C; Abi Kaed Bey, Samer; Floquet, Cedric F A; Mowlem, Matthew C

    2015-10-15

    The oceans are a major sink for anthropogenic atmospheric carbon dioxide, and the uptake causes changes to the marine carbonate system and has wide ranging effects on flora and fauna. It is crucial to develop analytical systems that allow us to follow the increase in oceanic pCO2 and corresponding reduction in pH. Miniaturised sensor systems using immobilised fluorescence indicator spots are attractive for this purpose because of their simple design and low power requirements. The technology is increasingly used for oceanic dissolved oxygen measurements. We present a detailed method on the use of immobilised fluorescence indicator spots to determine pH in ocean waters across the pH range 7.6-8.2. We characterised temperature (-0.046 pH/°C from 5 to 25 °C) and salinity dependences (-0.01 pH/psu over 5-35), and performed a preliminary investigation into the influence of chlorophyll on the pH measurement. The apparent pKa of the sensor spots was 6.93 at 20 °C. A drift of 0.00014 R (ca. 0.0004 pH, at 25 °C, salinity 35) was observed over a 3 day period in a laboratory based drift experiment. We achieved a precision of 0.0074 pH units, and observed a drift of 0.06 pH units during a test deployment of 5 week duration in the Southern Ocean as an underway surface ocean sensor, which was corrected for using certified reference materials. The temperature and salinity dependences were accounted for with the algorithm, R=0.00034-0.17·pH+0.15·S(2)+0.0067·T-0.0084·S·1.075. This study provides a first step towards a pH optode system suitable for autonomous deployment. The use of a short duration low power illumination (LED current 0.2 mA, 5 μs illumination time) improved the lifetime and precision of the spot. Further improvements to the pH indicator spot operations include regular application of certified reference materials for drift correction and cross-calibration against a spectrophotometric pH system. Desirable future developments should involve novel

  12. Biodiesel transesterification kinetics monitored by pH measurement.

    Science.gov (United States)

    Clark, William M; Medeiros, Nicholas J; Boyd, Donal J; Snell, Jared R

    2013-05-01

    Quantification of a pH change that was observed over the course of the transesterification reaction that converts vegetable oil to biodiesel may provide a simple method to monitor the reaction. Transesterification of canola oil at 6:1 methanol to oil ratio with 0.5 wt.% KOH as catalyst was studied at 25, 35, and 45 °C. Reaction conversion was correlated to pH measurements and the results were shown to be in agreement with an independent measure of conversion using an enzymatic assay for glycerol. Rate constants obtained from these measurements are consistent with those in the literature. The measured pH change appears to be related to dilution of OH(-) ions as the oil is converted to products rather than to depletion of OH(-) due to reaction. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Noninvasive Ph-telemetric Measurement of Gastrointestinal Function

    Science.gov (United States)

    Tietze, Karen J.

    1991-01-01

    The purpose of this study was to gain experience with and validate the Heidelberg pH-telemetric methodology in order to determine if the pH-telemetric methodology would be a useful noninvasive measure of gastrointestinal transit time for future ground-based and in-flight drug evaluation studies. The Heidelberg pH metering system is a noninvasive, nonradioactive telemetric system that, following oral ingestion, continuously measures intraluminal pH of the stomach, duodenum, small bowel, ileocecal junction, and large bowel. Gastrointestinal motility profiles were obtained in normal volunteers using the lactulose breath-hydrogen and Heidelberg pH metering techniques. All profiles were obtained in the morning after an overnight fast. Heidelberg pH profiles were obtained in the fasting and fed states; lactulose breath-hydrogen profiles were obtained after a standard breakfast. Mouth-to-cecum transit time was measured as the interval from administration of lactulose (30 ml; 20 g) to a sustained increase in breath-hydrogen of 10 ppm or more. Gastric emptying time was measured as the interval from the administration of the Heidelberg capsule to a sustained increase in pH of three units or more.

  14. Nanosensors for pH measurements in plants

    OpenAIRE

    Ytting, Cecilie Karkov; Fuglsang, Anja Thoe

    2007-01-01

    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...

  15. The Possible "Proton Sponge " Effect of Polyethylenimine (PEI) Does Not Include Change in Lysosomal pH

    DEFF Research Database (Denmark)

    Søndergaard, Rikke Vicki; Mattebjerg, Maria Ahlm; Henriksen, Jonas Rosager

    2013-01-01

    is still elusive. The "proton sponge " hypothesis remains the most generally accepted mechanism, although it is heavily debated. This hypothesis is associated with the large buffering capacity of PEI and other polycations, which has been interpreted to cause an increase in lysosomal pH even though...... no conclusive proof has been provided. In the present study, we have used a nanoparticle pH sensor that was developed for pH measurements in the endosomal/lysosomal pathway. We have carried out quantitative measurements of lysosomal pH as a function of PEI content and correlate the results to the "proton sponge...... " hypothesis. Our measurements show that PEI does not induce change in lysosomal pH as previously suggested and quantification of PEI concentrations in lysosomes makes it uncertain that the "proton sponge " effect is the dominant mechanism of polyplex escape.Molecular Therapy (2012); doi:10.1038/mt.2012.185....

  16. Canonical correlation of waste glass compositions and durability, including pH

    International Nuclear Information System (INIS)

    Oeksoy, D.; Pye, L.D.; Bickford, D.F.; Ramsey, W.G.

    1993-01-01

    Control of waste glass durability is a major concern in the immobilization of radioactive and mixed wastes. Leaching rate in standardized laboratory tests is being used as a demonstration of consistency of the response of waste glasses in the final disposal environment. The leaching of silicate and borosilicate glasses containing alkali or alkaline earth elements is known to be autocatalytic, in that the initial ion exchange of alkali in the glass for hydrogen ions in water results in the formation of OH and increases the pH of the leachate. The increased pH then increases the rate of silicate network attack, accelerating the leaching effect. In well formulated glasses this effect reaches a thermodynamic equilibrium when leachate saturation of a critical species, such as silica, or a dynamic equilibrium is reached when the pH shift caused by incremental leaching has negligible effect on pH. This report analyzes results of a seven leach test on waste glasses

  17. In vivo intracellular pH measurements in tobacco and Arabidopsis reveal an unexpected pH gradient in the endomembrane system.

    Science.gov (United States)

    Martinière, Alexandre; Bassil, Elias; Jublanc, Elodie; Alcon, Carine; Reguera, Maria; Sentenac, Hervé; Blumwald, Eduardo; Paris, Nadine

    2013-10-01

    The pH homeostasis of endomembranes is essential for cellular functions. In order to provide direct pH measurements in the endomembrane system lumen, we targeted genetically encoded ratiometric pH sensors to the cytosol, the endoplasmic reticulum, and the trans-Golgi, or the compartments labeled by the vacuolar sorting receptor (VSR), which includes the trans-Golgi network and prevacuoles. Using noninvasive live-cell imaging to measure pH, we show that a gradual acidification from the endoplasmic reticulum to the lytic vacuole exists, in both tobacco (Nicotiana tabacum) epidermal (ΔpH -1.5) and Arabidopsis thaliana root cells (ΔpH -2.1). The average pH in VSR compartments was intermediate between that of the trans-Golgi and the vacuole. Combining pH measurements with in vivo colocalization experiments, we found that the trans-Golgi network had an acidic pH of 6.1, while the prevacuole and late prevacuole were both more alkaline, with pH of 6.6 and 7.1, respectively. We also showed that endosomal pH, and subsequently vacuolar trafficking of soluble proteins, requires both vacuolar-type H(+) ATPase-dependent acidification as well as proton efflux mediated at least by the activity of endosomal sodium/proton NHX-type antiporters.

  18. Methodologically controlled variations in laboratory and field pH measurements in waterlogged soils

    DEFF Research Database (Denmark)

    Elberling, Bo; Matthiesen, Henning

    2007-01-01

    artefacts is critical. But the study includes agricultural and forest soils for comparison. At a waterlogged site, Laboratory results were compared with three different field methods: calomel pH probes inserted in the soil from pits, pH measurements of soil solution extracted from the soil, and pH profiles...... using a solid-state pH electrode pushed into the soil from the surface. Comparisons between in situ and laboratory methods revealed differences of more than 1 pH unit. The content of dissolved ions in soil solution and field observations of O2 and CO2 concentrations were used in the speciation model...... PHREEQE in order to predict gas exchange processes. Changes in pH in soil solution following equilibrium in the laboratory could be explained mainly by CO2 degassing. Only soil pH measured in situ using either calomel or solid-state probes inserted directly into the soil was not affected by gas exchange...

  19. Comparison of pH Data Measured with a pH Sensor Array Using Different Data Fusion Methods

    OpenAIRE

    Yi-Hung Liao; Jung-Chuan Chou

    2012-01-01

    This paper introduces different data fusion methods which are used for an electrochemical measurement using a sensor array. In this study, we used ruthenium dioxide sensing membrane pH electrodes to form a sensor array. The sensor array was used for detecting the pH values of grape wine, generic cola drink and bottled base water. The measured pH data were used for data fusion methods to increase the reliability of the measured results, and we also compared the fusion results with other differ...

  20. Comparison of pH Data Measured with a pH Sensor Array Using Different Data Fusion Methods

    Directory of Open Access Journals (Sweden)

    Yi-Hung Liao

    2012-09-01

    Full Text Available This paper introduces different data fusion methods which are used for an electrochemical measurement using a sensor array. In this study, we used ruthenium dioxide sensing membrane pH electrodes to form a sensor array. The sensor array was used for detecting the pH values of grape wine, generic cola drink and bottled base water. The measured pH data were used for data fusion methods to increase the reliability of the measured results, and we also compared the fusion results with other different data fusion methods.

  1. 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

  2. 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...

  3. Extraction of indirectly captured information for use in a comparison of offline pH measurement technologies.

    Science.gov (United States)

    Ritchie, Elspeth K; Martin, Elaine B; Racher, Andy; Jaques, Colin

    2017-06-10

    Understanding the causes of discrepancies in pH readings of a sample can allow more robust pH control strategies to be implemented. It was found that 59.4% of differences between two offline pH measurement technologies for an historical dataset lay outside an expected instrument error range of ±0.02pH. A new variable, Osmo Res , was created using multiple linear regression (MLR) to extract information indirectly captured in the recorded measurements for osmolality. Principal component analysis and time series analysis were used to validate the expansion of the historical dataset with the new variable Osmo Res . MLR was used to identify variables strongly correlated (p<0.05) with differences in pH readings by the two offline pH measurement technologies. These included concentrations of specific chemicals (e.g. glucose) and Osmo Res, indicating culture medium and bolus feed additions as possible causes of discrepancies between the offline pH measurement technologies. Temperature was also identified as statistically significant. It is suggested that this was a result of differences in pH-temperature compensations employed by the pH measurement technologies. In summary, a method for extracting indirectly captured information has been demonstrated, and it has been shown that competing pH measurement technologies were not necessarily interchangeable at the desired level of control (±0.02pH). Copyright © 2017 Elsevier B.V. All rights reserved.

  4. 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.

  5. 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

  6. Characterizing the variation in pH measurements with apheresis platelets.

    Science.gov (United States)

    Moroff, Gary; Seetharaman, Shalini; Kurtz, James; Wagner, Stephen J

    2011-11-01

    pH measurements of platelet (PLT) components remain a key parameter when assessing how storage and shipping conditions influence the retention of PLT properties. Studies were conducted to characterize variations in pH measured with two pH meters and a blood gas analyzer. Samples were obtained from apheresis PLT units that were stored with or without continuous agitation to measure a range of pH values. pH values were determined with pH meters at room temperature (20-24°C) upon placing of samples in 5-mL sterile polypropylene tubes and with the blood gas analyzer at 37°C upon injection of identical samples, with conversion to 22°C. The calculated coefficient of variation (%CV) of pH measurements using pH meters (n = 10) was 0.43% or less. The %CV values were comparable with different samples having pH values ranging from 6.0 to 7.4. The %CV levels with the blood gas analyzer were comparable to those observed with the pH meters. The difference in the mean pH values for the two pH meters was no greater than 0.10 units, with 9 of 10 samples having differences in values of 0.05 or less; however, greater differences of values (0.1 to 0.2) were observed between pH measured using the blood gas analyzer and pH meters. Our data show good precision and comparability of pH measurements with two pH meters. Differences in pH values were greater on comparison of the blood gas analyzer with the pH meters. © 2011 American Association of Blood Banks.

  7. ISFET sensor evaluation and modification for seawater pH measurement

    Science.gov (United States)

    Martz, T. R.; Johnson, K. S.; Jannasch, H.; Coletti, L.; Barry, J.; Lovera, C.

    2008-12-01

    In the future, short-term cycles (daily to subannual) and long-term trends (annual and greater) in the carbonate system will be observed by autonomous sensors operating from a variety of platforms (e.g., moorings, profiling floats, AUVs, etc.). Of the four carbonate parameters, pH measurement has the longest history of development - yet robust autonomous sensing techniques remain elusive due to a catalog of technical challenges. Existing commercial sensor technologies generally do not meet the stringent demands of accuracy, long-term stability, low power, pressure tolerance, resistance to biofouling, and ease of use required by the oceanographic community. We report here on some recent advances in Ion Sensitive Field Effect Transistor (ISFET) technology that may open the door for more widespread autonomous seawater pH measurements. Much of our work has focused on applications of the Honeywell Durafet pH sensor, a product designed for industrial process control. Initial results from laboratory testing and deployments in the MBARI test tank and near shore moorings will be presented. Sensor calibration techniques will be addressed. Applications of now-available off-the-shelf sensors including shipboard underway measurement, shallow water mooring deployment, and a gas controlled seawater aquarium for pH perturbation experiments will be discussed. We hope that an ongoing collaboration between MBARI and Honeywell will result in a commercially available product, designed specifically for oceanographic applications, within the next several years.

  8. pH measurement of tubular vacuoles of an arbuscular mycorrhizal fungus, Gigaspora margarita.

    Science.gov (United States)

    Funamoto, Rintaro; Saito, Katsuharu; Oyaizu, Hiroshi; Aono, Toshihiro; Saito, Masanori

    2015-01-01

    Arbuscular mycorrhizal fungi play an important role in phosphate supply to the host plants. The fungal hyphae contain tubular vacuoles where phosphate compounds such as polyphosphate are accumulated. Despite their importance for the phosphate storage, little is known about the physiological properties of the tubular vacuoles in arbuscular mycorrhizal fungi. As an indicator of the physiological state in vacuoles, we measured pH of tubular vacuoles in living hyphae of arbuscular mycorrhizal fungus Gigaspora margarita using ratio image analysis with pH-dependent fluorescent probe, 6-carboxyfluorescein. Fluorescent images of the fine tubular vacuoles were obtained using a laser scanning confocal microscope, which enabled calculation of vacuolar pH with high spatial resolution. The tubular vacuoles showed mean pH of 5.6 and a pH range of 5.1-6.3. These results suggest that the tubular vacuoles of arbuscular mycorrhizal fungi have a mildly acidic pH just like vacuoles of other fungal species including yeast and ectomycorrhizal fungi.

  9. Polymeric pH nanosensor with extended measurement range bearing octaarginine as cell penetrating peptide

    DEFF Research Database (Denmark)

    Ke, Peng; Sun, Honghao; Liu, Mingxing

    2016-01-01

    A synthetic peptide octaarginine which mimics human immunodeficiency virus-1, Tat protein is used as cell penetrating moiety for new pH nanosensors which demonstrate enhanced cellular uptake and expanded measurement range from pH 3.9 to pH 7.3 by simultaneously incorporating two complemental pH-s......H-sensitive fluorophores in a same nanoparticle. The authors believe that this triple fluorescent pH sensor provides a new tool to pH measurements that can have application in cellular uptake mechanism study and new nanomedicine design.......A synthetic peptide octaarginine which mimics human immunodeficiency virus-1, Tat protein is used as cell penetrating moiety for new pH nanosensors which demonstrate enhanced cellular uptake and expanded measurement range from pH 3.9 to pH 7.3 by simultaneously incorporating two complemental p...

  10. Measurement of pH, exudate composition and temperature in wound healing: a systematic review.

    Science.gov (United States)

    Power, G; Moore, Z; O'Connor, T

    2017-07-02

    To assess the potential of measurements of pH, exudate composition and temperature in wounds to predict healing outcomes and to identify the methods that are employed to measure them. A systematic review based on the outcomes of a search strategy of quantitative primary research published in the English language was conducted. Inclusion criteria limited studies to those involving in vivo and human participants with an existing or intentionally provoked wound, defined as 'a break in the epithelial integrity of the skin', and excluded in vitro and animal studies. Data synthesis and analysis was performed using structured narrative summaries of each included study arranged by concept, pH, exudate composition and temperature. The Evidence Based Literature (EBL) Critical Appraisal Checklist was implemented to appraise the quality of the included studies. A total of 23 studies, three for pH (mean quality score 54.48%), 12 for exudate composition (mean quality score 46.54%) and eight for temperature (mean quality score 36.66%), were assessed as eligible for inclusion in this review. Findings suggest that reduced pH levels in wounds, from alkaline towards acidic, are associated with improvements in wound condition. Metalloproteinase-9 (MMP-9), matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase (TIMP), neutrophil elastase (NE) and albumin, in descending order, were the most frequently measured analytes in wounds. MMP-9 emerged as the analyte which offers the most potential as a biomarker of wound healing, with elevated levels observed in acute or non-healing wounds and decreasing levels in wounds progressing in healing. Combined measures of different exudate components, such as MMP/TIMP ratios, also appeared to offer substantial potential to indicate wound healing. Finally, temperature measurements are highest in non-healing, worsening or acute wounds and decrease as wounds progress towards healing. Methods used to measure pH, exudate composition and

  11. In situ measurements reveal extremely low pH in soil

    DEFF Research Database (Denmark)

    Nielsen, Knud Erik; Loibide, Amaia Irixar; Nielsen, Lars Peter

    2017-01-01

    We measured pH in situ in the top organic soil horizons in heathland and pine forest and found values between 2.6 and 3.2. This was 0.5e0.8 units lower than concurrent laboratory pH measurements of the same soil, which raises questions about the interpretation of pH measurements. We propose that ...... that the higher pH recorded by standard laboratory methods may be due to buffering ions from soil biota released from drying, grinding and rewetting of soil samples, whereas the in situ pH reflects the correct level of acidification....

  12. Measures for Ph.D. Evaluation: The Recruitment Process

    Science.gov (United States)

    D'Agostino, Antonella; Fruzzetti, Stefania; Ghellini, Giulio; Neri, Laura

    2011-01-01

    In the last years the quality of Higher Education (HE) system and its evaluation have been key issues of the political and scientific debate on education policies all over Europe. In the wide landscape that involves the entire HE system we draw attention on the third level of its organization, i.e. the Ph.D. In particular, this paper discusses the…

  13. Skin physiology in men and women: in vivo evaluation of 300 people including TEWL, SC hydration, sebum content and skin surface pH.

    Science.gov (United States)

    Luebberding, S; Krueger, N; Kerscher, M

    2013-10-01

    Evidence is given that differences in skin physiological properties exist between men and women. However, despite an assessable number of available publications, the results are still inconsistent. Therefore, the aim of this clinical study is the first systematic assessment of gender-related differences in skin physiology in men and women, with a special focus on changes over lifetime. A total of 300 healthy male and female subjects (20-74 years) were selected following strict criteria including age, sun behaviour or smoking habits. TEWL, hydration level, sebum production and pH value were measured with worldwide-acknowledged biophysical measuring methods at forehead, cheek, neck, volar forearm and dorsum of hand. Until the age of 50 men's TEWL is significantly lower than the water loss of women of the same age, regardless of the location. With ageing gender-related differences in TEWL assimilate. Young men show higher SC hydration in comparison with women. But, whereas SC hydration is stable or even increasing in women over lifetime, the skin hydration in men is progressively decreasing, beginning at the age of 40. Sebum production in male skin is always higher and stays stable with increasing age, whereas sebum production in women progressively decreases over lifetime. Across all localizations and age groups, the pH value in men is below 5, the pH value of female subjects is, aside from limited expectations, higher than 5. Skin physiological distinctions between the sexes exist and are particularly remarkable with regard to sebum production and pH value. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  14. Meta-Cresol Purple Reference Material® (RM) for Seawater pH Measurements

    Science.gov (United States)

    Easley, R. A.; Waters, J. F.; Place, B. J.; Pratt, K. W.

    2016-02-01

    The pH of seawater is a fundamental quantity that governs the carbon dioxide - carbonate system in the world's oceans. High quality pH measurements for long-term monitoring, shipboard studies, and shorter-term biological studies (mesocosm and field experiments) can be ensured through a reference material (RM) that is compatible with existing procedures and which is traceable to primary pH measurement metrology. High-precision spectrophotometric measurements of seawater pH using an indicator dye such as meta-cresol purple (mCP) are well established. However, traceability of these measurements to the International System of Units (SI) additionally requires characterizing the spectrophotometric pH response of the dye in multiple artificial seawater buffers that themselves are benchmarked via primary pH (Harned cell) measurements at a range of pH, salinity, and temperature. NIST is currently developing such a mCP pH RM using this approach. This material will also incorporate new procedures developed at NIST for assessing the purity and homogeneity of the mCP reagent itself. The resulting mCP will provide long-term (years) stability and ease of shipment compared to artificial seawater pH buffers. These efforts will provide the oceanographic user community with a NIST issued mCP (RM), characterized as to its molar absorptivity values and acid dissociation constants (pKa), with uncertainties that comply with the Guide to the Expression of Uncertainty in Measurement (GUM).

  15. pH measurements of FET-based (bio)chemical sensors using portable measurement system.

    Science.gov (United States)

    Voitsekhivska, T; Zorgiebel, F; Suthau, E; Wolter, K-J; Bock, K; Cuniberti, G

    2015-01-01

    In this study we demonstrate the sensing capabilities of a portable multiplex measurement system for FET-based (bio)chemical sensors with an integrated microfluidic interface. We therefore conducted pH measurements with Silicon Nanoribbon FET-based Sensors using different measurement procedures that are suitable for various applications. We have shown multiplexed measurements in aqueous medium for three different modes that are mutually specialized in fast data acquisition (constant drain current), calibration-less sensing (constant gate voltage) and in providing full information content (sweeping mode). Our system therefore allows surface charge sensing for a wide range of applications and is easily adaptable for multiplexed sensing with novel FET-based (bio)chemical sensors.

  16. In vivo measurement of cytosolic and mitochondrial pH using a pH-sensitive GFP derivative in Saccharomyces cerevisiae reveals a relation between intracellular pH and growth

    NARCIS (Netherlands)

    Orij, R.; Postmus, J.; ter Beek, A.; Brul, S.; Smits, G.J.

    2009-01-01

    The specific pH values of cellular compartments affect virtually all biochemical processes, including enzyme activity, protein folding and redox state. Accurate, sensitive and compartment-specific measurements of intracellular pH (pHi) dynamics in living cells are therefore crucial to the

  17. Measurement of the Extracellular pH of Adherently Growing Mammalian Cells with High Spatial Resolution Using a Voltammetric pH Microsensor.

    Science.gov (United States)

    Munteanu, Raluca-Elena; Stǎnicǎ, Luciana; Gheorghiu, Mihaela; Gáspár, Szilveszter

    2018-05-15

    There are only a few tools suitable for measuring the extracellular pH of adherently growing mammalian cells with high spatial resolution, and none of them is widely used in laboratories around the world. Cell biologists very often limit themselves to measuring the intracellular pH with commercially available fluorescent probes. Therefore, we built a voltammetric pH microsensor and investigated its suitability for monitoring the extracellular pH of adherently growing mammalian cells. The voltammetric pH microsensor consisted of a 37 μm diameter carbon fiber microelectrode modified with reduced graphene oxide and syringaldazine. While graphene oxide was used to increase the electrochemically active surface area of our sensor, syringaldazine facilitated pH sensing through its pH-dependent electrochemical oxidation and reduction. The good sensitivity (60 ± 2.5 mV/pH unit), reproducibility (coefficient of variation ≤3% for the same pH measured with 5 different microsensors), and stability (pH drift around 0.05 units in 3 h) of the built voltammetric pH sensors were successfully used to investigate the acidification of the extracellular space of both cancer cells and normal cells. The results indicate that the developed pH microsensor and the perfected experimental protocol based on scanning electrochemical microscopy can reveal details of the pH regulation of cells not attainable with pH sensors lacking spatial resolution or which cannot be reproducibly positioned in the extracellular space.

  18. Global Analysis of Solar Neutrino Oscillations Including SNO CC Measurement

    CERN Document Server

    Bahcall, J N; Peña-Garay, C; Bahcall, John N; Peña-Garay, Carlos

    2001-01-01

    For active and sterile neutrinos, we present the globally allowed solutions for two neutrino oscillations. We include the SNO CC measurement and all other relevant solar neutrino and reactor data. Five active neutrino oscillation solutions (LMA, LOW, SMA, VAC, and Just So2) are currently allowed at 3 sigma; three sterile neutrino solutions (Just So2, SMA, and VAC) are allowed at 3 sigma. The goodness of fit is satisfactory for all eight solutions. We also investigate the robustness of the allowed solutions by carrying out global analyses with and without: 1) imposing solar model constraints on the 8B neutrino flux, 2) including the Super-Kamiokande spectral energy distribution and day-night data, 3) using an enhanced CC cross section for deuterium (due to radiative corrections), and 4) a optimistic, hypothetical reduction by a factor of three of the error of the SNO CC rate. For every analysis strategy used in this paper, the most favored solutions all involve large mixing angles: LMA, LOW, or VAC. The favore...

  19. Apoplastic pH in corn root gravitropism: a laser scanning confocal microscopy measurement

    International Nuclear Information System (INIS)

    Taylor, D.P.; Slattery, J.; Leopold, A.C.

    1996-01-01

    The ability to measure the pH of the apoplast in situ is of special interest as a test of the cell wall acidification theory. Optical sectioning of living seedlings of corn roots using the laser scanning confocal microscope (LSCM) permits us to make pH measurements in living tissue. The pH of the apoplast of corn roots was measured by this method after infiltration with CI-NERF, a pH-sensitive dye, along with Texas Red Dextran 3000, a pH-insensitive dye, as an internal standard. In the elongation zone of corn roots, the mean apoplastic pH was 4.9. Upon gravitropic stimulation, the pH on the convex side of actively bending roots was 4.5. The lowering of the apoplastic pH by 0.4 units appears to be sufficient to account for the increased growth on that side. This technique provides site-specific evidence for the acid growth theory of cell elongation. The LSCM permits measurements of the pH of living tissues, and has a sensitivity of approximately 0.2 pH units. (author)

  20. Predicting and measurement of pH of seawater reverse osmosis concentrates

    KAUST Repository

    Waly, Tarek; Kennedy, Maria Dolores; Witkamp, Geert-Jan; Amy, Gary L.; Schippers, Jan Cornelis

    2011-01-01

    The pH of seawater reverse osmosis plants (SWRO) is the most influential parameter in determining the degree of supersaturation of CaCO3 in the concentrate stream. For this, the results of pH measurements of the concentrate of a seawater reverse

  1. Measurement of pH micro-heterogeneity in natural cheese matrices by fluorescence lifetime imaging

    Directory of Open Access Journals (Sweden)

    Zuzana eBurdikova

    2015-03-01

    Full Text Available Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g. pH, redox potential due to their metabolic activity. While cheese pH may be measured at macro level there remains a significant knowledge gap relating to the degree of micro-heterogeneity of pH within the cheese matrix and its relationship with microbial, enzymatic and physiochemical parameters and ultimately with cheese quality, consistency and ripening patterns. The pH of cheese samples was monitored both at macroscopic scale and at microscopic scale, using a non-destructive microscopic technique employing C-SNARF-4 and Oregon Green 488 fluorescent probes. The objectives of this work were to evaluate the suitability of these dyes for microscale pH measurements in natural cheese matrices and to enhance the sensitivity and extend the useful pH range of these probes using fluorescence lifetime imaging (FLIM. In particular, fluorescence lifetime of Oregon Green 488 proved to be sensitive probe to map pH micro heterogeneity within cheese matrices. Good agreement was observed between macroscopic scale pH measurement by FLIM and by traditional pH methods, but in addition considerable localized microheterogeneity in pH was evident within the curd matrix with pH range between 4.0 and 5.5. This technique provides significant potential to further investigate the relationship between cheese matrix physico-chemistry and bacterial metabolism during cheese manufacture and ripening.

  2. Measurement of pH micro-heterogeneity in natural cheese matrices by fluorescence lifetime imaging.

    Science.gov (United States)

    Burdikova, Zuzana; Svindrych, Zdenek; Pala, Jan; Hickey, Cian D; Wilkinson, Martin G; Panek, Jiri; Auty, Mark A E; Periasamy, Ammasi; Sheehan, Jeremiah J

    2015-01-01

    Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level there remains a significant knowledge gap relating to the degree of micro-heterogeneity of pH within the cheese matrix and its relationship with microbial, enzymatic and physiochemical parameters and ultimately with cheese quality, consistency and ripening patterns. The pH of cheese samples was monitored both at macroscopic scale and at microscopic scale, using a non-destructive microscopic technique employing C-SNARF-4 and Oregon Green 488 fluorescent probes. The objectives of this work were to evaluate the suitability of these dyes for microscale pH measurements in natural cheese matrices and to enhance the sensitivity and extend the useful pH range of these probes using fluorescence lifetime imaging (FLIM). In particular, fluorescence lifetime of Oregon Green 488 proved to be sensitive probe to map pH micro heterogeneity within cheese matrices. Good agreement was observed between macroscopic scale pH measurement by FLIM and by traditional pH methods, but in addition considerable localized microheterogeneity in pH was evident within the curd matrix with pH range between 4.0 and 5.5. This technique provides significant potential to further investigate the relationship between cheese matrix physico-chemistry and bacterial metabolism during cheese manufacture and ripening.

  3. Measuring pH variability using an experimental sensor on an underwater glider

    Science.gov (United States)

    Hemming, Michael P.; Kaiser, Jan; Heywood, Karen J.; Bakker, Dorothee C. E.; Boutin, Jacqueline; Shitashima, Kiminori; Lee, Gareth; Legge, Oliver; Onken, Reiner

    2017-05-01

    Autonomous underwater gliders offer the capability of measuring oceanic parameters continuously at high resolution in both vertical and horizontal planes, with timescales that can extend to many months. An experimental ion-sensitive field-effect transistor (ISFET) sensor measuring pH on the total scale was attached to a glider during the REP14-MED experiment in June 2014 in the Sardinian Sea in the northwestern Mediterranean. During the deployment, pH was sampled at depths of up to 1000 m along an 80 km transect over a period of 12 days. Water samples were collected from a nearby ship and analysed for dissolved inorganic carbon concentration and total alkalinity to derive the pH for validating the ISFET sensor measurements. The vertical resolution of the pH sensor was good (1 to 2 m), but stability was poor and the sensor drifted in a non-monotonous fashion. In order to remove the sensor drift, a depth-constant time-varying offset was applied throughout the water column for each dive, reducing the spread of the data by approximately two-thirds. Furthermore, the ISFET sensor required temperature- and pressure-based corrections, which were achieved using linear regression. Correcting for this decreased the apparent sensor pH variability by a further 13 to 31 %. Sunlight caused an apparent sensor pH decrease of up to 0.1 in surface waters around local noon, highlighting the importance of shielding the sensor from light in future deployments. The corrected pH from the ISFET sensor is presented along with potential temperature, salinity, potential density anomalies (σθ), and dissolved oxygen concentrations (c(O2)) measured by the glider, providing insights into the physical and biogeochemical variability in the Sardinian Sea. The pH maxima were identified close to the depth of the summer chlorophyll maximum, where high c(O2) values were also found. Longitudinal pH variations at depth (σθ > 28. 8 kg m-3) highlighted the variability of water masses in the Sardinian

  4. CMOS COLOUR SENSOR BASED pH MEASUREMENT FOR WATER QUALITY ANALYSIS

    OpenAIRE

    Sanjay Kumar; Arvind Singh

    2016-01-01

    A Real-Time pH measurement system using a novel design Programmable CMOS optical Colour light to frequency converter TCS230 is presented. The system uses Bogen’s universal indicator solution combined with a white light source and the Programmable CMOS colour sensor TCS230 to measure pH as a function of colour change in a sample. Bogen’s universal indicator solution causes a colour change in a sample according to the pH of the sample. The output frequency from the colour-sensitive CM...

  5. An analysis of dietary fiber and fecal fiber components including pH in rural Africans with colorectal cancer

    Directory of Open Access Journals (Sweden)

    Mohammed Faruk

    2018-01-01

    Full Text Available Background/Aims: Colorectal cancer (CRC is now a major public health problem with heavy morbidity and mortality in rural Africans despite the lingering dietary fiber-rich foodstuffs consumption. Studies have shown that increased intake of dietary fiber which contribute to low fecal pH and also influences the activity of intestinal microbiota, is associated with a lowered risk for CRC. However, whether or not the apparent high dietary fiber consumption by Africans do not longer protects against CRC risk is unknown. This study evaluated dietary fiber intake, fecal fiber components and pH levels in CRC patients. Methods: Thirty-five subjects (CRC=21, control=14, mean age 45 years were recruited for the study. A truncated food frequency questionnaire and modified Goering and Van Soest procedures were used. Results: We found that all subjects consumed variety of dietary fiber-rich foodstuffs. There is slight preponderance in consumption of dietary fiber by the control group than the CRC patients. We also found a significant difference in the mean fecal neutral detergent fiber, acid detergent fiber, hemicellulose, cellulose and lignin contents from the CRC patients compared to the controls (P<0.05. The CRC patients had significantly more fecal pH level than the matched apparently healthy controls (P=0.017. Conclusions: The identified differences in the fecal fiber components and stool pH levels between the 2 groups may relate to CRC incidence and mortality in rural Africans. There is crucial need for more hypothesis-driven research with adequate funding on the cumulative preventive role of dietary fiber-rich foodstuffs against colorectal cancer in rural Africans “today.”

  6. An analysis of dietary fiber and fecal fiber components including pH in rural Africans with colorectal cancer.

    Science.gov (United States)

    Faruk, Mohammed; Ibrahim, Sani; Adamu, Ahmed; Rafindadi, Abdulmumini Hassan; Ukwenya, Yahaya; Iliyasu, Yawale; Adamu, Abdullahi; Aminu, Surajo Mohammed; Shehu, Mohammed Sani; Ameh, Danladi Amodu; Mohammed, Abdullahi; Ahmed, Saad Aliyu; Idoko, John; Ntekim, Atara; Suleiman, Aishatu Maude; Shah, Khalid Zahir; Adoke, Kasimu Umar

    2018-01-01

    Colorectal cancer (CRC) is now a major public health problem with heavy morbidity and mortality in rural Africans despite the lingering dietary fiber-rich foodstuffs consumption. Studies have shown that increased intake of dietary fiber which contribute to low fecal pH and also influences the activity of intestinal microbiota, is associated with a lowered risk for CRC. However, whether or not the apparent high dietary fiber consumption by Africans do not longer protects against CRC risk is unknown. This study evaluated dietary fiber intake, fecal fiber components and pH levels in CRC patients. Thirty-five subjects (CRC=21, control=14), mean age 45 years were recruited for the study. A truncated food frequency questionnaire and modified Goering and Van Soest procedures were used. We found that all subjects consumed variety of dietary fiber-rich foodstuffs. There is slight preponderance in consumption of dietary fiber by the control group than the CRC patients. We also found a significant difference in the mean fecal neutral detergent fiber, acid detergent fiber, hemicellulose, cellulose and lignin contents from the CRC patients compared to the controls ( P fiber components and stool pH levels between the 2 groups may relate to CRC incidence and mortality in rural Africans. There is crucial need for more hypothesis-driven research with adequate funding on the cumulative preventive role of dietary fiber-rich foodstuffs against colorectal cancer in rural Africans "today."

  7. Dual mode antimony electrode for simultaneous measurements of PO2 and pH.

    Science.gov (United States)

    Sjöberg, F; Nilsson, G

    2000-01-01

    In biomedical research and clinical medicine there is a demand for potent sensors to measure the components that make up blood gas analyses. Today, as when the electrochemical PO2, PCO2 and pH electrodes were first introduced, these measurements are usually made with the same type of sensor technology. The aims of the present study were, firstly, to find out whether the platinum cathode in the Clark electrode can be replaced by antimony for oxygen measurements (amperometry (A)); secondly, whether, during oxygen measurements, the inherent corrosion potential of the antimony metal can be used for measurement of pH in the same measurement area (potentiometry (P)). An electrode of purified, crystallographically orientated monocrystalline antimony (COMA) connected to a reference electrode (silver-silver chloride) was used for the P measurements. Measurements of A (at -900 mV) and P were made in an aqueous environment regulated for oxygen, pH, and temperature. Reproducible oxygen sensitivities of 0.925 nA/% oxygen (2% CV (coefficient of variation)) (A), 10.7 mV/% (P), and 0.7 mV/% (P) were found in the oxygen range: 0-21%, <5%, and above 5%, respectively. The pH sensitivity was 57 mV/pH unit (P). Oxygen and pH measurements were less accurate at oxygen concentrations close to 0%. Both the oxygen and pH part of the composite electrode signal can be identified by this dual mode technique (A and P). The sensor seems to be promising as it provides measurements of two separate variables (oxygen and pH) and also has the desirable characteristics of a solid state sensor.

  8. Optimization of the automated colorimetric measurement system for pH of liquid

    Directory of Open Access Journals (Sweden)

    Katin Oleg

    2017-01-01

    Full Text Available This article considers the issue of automatic control of the acidity of the aquatic environment, which is relevant in such branches of agriculture as hydroponics and aeroponics. A method for measuring the pH of a liquid using a potentiometric method is considered. This method allows to obtain the most accurate pH values, but has some drawbacks. In particular, the article analyzes the advantages of this method over the use of a universal indicator paper and a color sensor for pH determination, describes the components, the conditions of their operation and storage, describes the basic principles of the measuring system operation. A method for converting a signal received at a pH electrode into a microcontroller suitable for processing is also contemplated. The main goal of the development and application of the measuring system described in the article is to achieve a high degree of autonomy and automation of aeroponic and hydroponic greenhouse complexes.

  9. Measurements for testing of fluoroscopic screens, including the photofluorographic units

    International Nuclear Information System (INIS)

    Balfanz, R.

    1986-01-01

    Image quality control measurements for fluoroscopic screens and photofluorographs have shown that both types of equipment have a long operating life, so that constancy and technical performance tests are absolutely necessary. It is recommended to conclude in-service maintenance contracts with the manufacturers. (DG) [de

  10. Measurements of spectral responses for developing fiber-optic pH sensor

    Science.gov (United States)

    Yoo, Wook Jae; Heo, Ji Yeon; Jang, Kyoung Won; Seo, Jeong Ki; Moon, Jin Soo; Park, Jang-Yeon; Park, Byung Gi; Cho, Seunghyun; Lee, Bongsoo

    2011-01-01

    In this study, we have fabricated a fiber-optic pH sensor, which is composed of a light source, a pH-sensing probe, plastic optical fibers and a spectrometer, for determining the degree of infection by Helicobacter pylori in the stomach. As pH indicators, phenol red and m-cresol purple are used, and pH liquid solutions are prepared by mixing phenol red or m-cresol purple solutions and various kinds of pH buffer solutions. The light emitted by a light source is guided by plastic optical fibers to the pH liquid solution, and the optical characteristic of a reflected light is changed according to the color variations of the pH indicator in the pH-sensing probe. Therefore, we have measured the intensities and wavelength shifts of the reflected lights, which change according to the color variations of indicators at different pH values, by using a spectrometer for spectral analysis. Also, the relationships between the pH values of liquid solutions and the optical properties of the modulated lights are obtained on the basis of the changes of the colors of indicators.

  11. A tunable ratiometric pH sensor based on carbon nanodots for the quantitative measurement of the intracellular pH of whole cells.

    Science.gov (United States)

    Shi, Wen; Li, Xiaohua; Ma, Huimin

    2012-06-25

    The whole picture: Carbon nanodots labeled with two fluorescent dyes have been developed as a tunable ratiometric pH sensor to measure intracellular pH. The nanosensor shows good biocompatibility and cellular dispersibility. Quantitative determinations on intact HeLa cells and pH fluctuations associated with oxidative stress were performed. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Drilling and associated drillhole measurements of the pilot hole ONK-PH12

    International Nuclear Information System (INIS)

    Toropainen, V.; Tarvainen, A.-M.; Poellaenen, J.; Pekkanen, J.; Pere, T.; Kaepyaho, E.; Lahti, M.

    2011-01-01

    The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are drillholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes are aimed to confirm the quality of the rock mass for tunnel construction, and in particular to identify water conductive fractured zones and to provide information that could result in modifications of the existing construction plans. The pilot hole ONK-PH12 was drilled from ONKALO chainage 4092 to chainage 4215 in January 2010. The length of the hole is 123.96 metres. The drilling method was orientated core drilling. The deviation of the drillhole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss, and weathering. The rock mechanical logging was based on Q-classification. The test to determine rock strength and deformation were made with Rock Tester -equipment. Water conductivity of the fractures or fractured zones was measured by Posiva Flow Log equipment. The measurements were done in two phases. During flow measurements also grounding resistance electric conductivity and temperature were measured. In flow logging test, sections of 0.5 m with increments of 0.1 m were used. Water loss measurements were conducted in the drillhole section 5.0-123.85 m dhd. Geophysical logging as well as optical and acoustic imaging of the pilot hole included the fieldwork of all surveys, the integration of the data as well as interpretation of the acoustic and drillhole radar data. Groundwater sampling was not applicable because no

  13. Development of a colorimetric microfluidic pH sensor for autonomous seawater measurements.

    Science.gov (United States)

    Rérolle, Victoire M C; Floquet, Cedric F A; Harris, Andy J K; Mowlem, Matt C; Bellerby, Richard R G J; Achterberg, Eric P

    2013-07-05

    High quality carbonate chemistry measurements are required in order to fully understand the dynamics of the oceanic carbonate system. Seawater pH data with good spatial and temporal coverage are particularly critical to apprehend ocean acidification phenomena and their consequences. There is a growing need for autonomous in situ instruments that measure pH on remote platforms. Our aim is to develop an accurate and precise autonomous in situ pH sensor for long term deployment on remote platforms. The widely used spectrophotometric pH technique is capable of the required high-quality measurements. We report a key step towards the miniaturization of a colorimetric pH sensor with the successful implementation of a simple microfluidic design with low reagent consumption. The system is particularly adapted to shipboard deployment: high quality data was obtained over a period of more than a month during a shipboard deployment in northwest European shelf waters, and less than 30 mL of indicator was consumed. The system featured a short term precision of 0.001 pH (n=20) and an accuracy within the range of a certified Tris buffer (0.004 pH). The quality of the pH system measurements have been checked using various approaches: measurements of certified Tris buffer, measurement of certified seawater for DIC and TA, comparison of measured pH against calculated pH from pCO2, DIC and TA during the cruise in northwest European shelf waters. All showed that our measurements were of high quality. The measurements were made close to in situ temperature (+0.2°C) in a sampling chamber which had a continuous flow of the ship's underway seawater supply. The optical set up was robust and relatively small due to the use of an USB mini-spectrometer, a custom made polymeric flow cell and an LED light source. The use of a three wavelength LED with detection that integrated power across the whole of each LED output spectrum indicated that low wavelength resolution detectors can be used

  14. A method for measuring pH at high temperatures is presented

    International Nuclear Information System (INIS)

    Chaudon, Luc.

    1979-01-01

    Two hydrogen electrodes are used and set up in a PTFE cell comprising two chambers connected through a saturated potassium chloride solution bridge. This cell is put in an autoclave containing hydrogen. The potential difference of the following cell is measured: H 2 , Pt, R solution - KCl saturated solution at 25 0 C - X solution, Pt, H 2 - The pH of the reference solution R is known up to 300 0 C and the X solution must have its pH to be determined. The precision of the measures at 300 0 C is estimated about +-0,1 pH unit. The dissociation constant of water is calculated from pH variations of alcaline solutions up to 300 0 C. The method has helped to measure the pH at 300 0 C of some boric acid solutions, with or without lithium hydroxide additions, in the following concentration range: B: 250 to 1500 ppm and Li: 0 to 3 ppm. Some concentrations are in fact those chosen for the primary circuits of pressurized water reactors. The pH of ammoniacal solutions is measured too and helped to determine the variations of the dissociation constant of ammonia with temperature [fr

  15. A miniature integrated multimodal sensor for measuring pH, EC and temperature for precision agriculture.

    Science.gov (United States)

    Futagawa, Masato; Iwasaki, Taichi; Murata, Hiroaki; Ishida, Makoto; Sawada, Kazuaki

    2012-01-01

    Making several simultaneous measurements with different kinds of sensors at the same location in a solution is difficult because of crosstalk between the sensors. In addition, because the conditions at different locations in plant beds differ, in situ measurements in agriculture need to be done in small localized areas. We have fabricated a multimodal sensor on a small Si chip in which a pH sensor was integrated with electrical conductivity (EC) and temperature sensors. An ISFET with a Si(3)N(4) membrane was used for the pH sensor. For the EC sensor, the electrical conductivity between platinum electrodes was measured, and the temperature sensor was a p-n junction diode. These are some of the most important measurements required for controlling the conditions in plant beds. The multimodal sensor can be inserted into a plant bed for in situ monitoring. To confirm the absence of crosstalk between the sensors, we made simultaneous measurements of pH, EC, and temperature of a pH buffer solution in a plant bed. When the solution was diluted with hot or cold water, the real time measurements showed changes to the EC and temperature, but no change in pH. We also demonstrated that our sensor was capable of simultaneous in situ measurements in rock wool without being affected by crosstalk.

  16. A Miniature Integrated Multimodal Sensor for Measuring pH, EC and Temperature for Precision Agriculture

    Directory of Open Access Journals (Sweden)

    Hiroaki Murata

    2012-06-01

    Full Text Available Making several simultaneous measurements with different kinds of sensors at the same location in a solution is difficult because of crosstalk between the sensors. In addition, because the conditions at different locations in plant beds differ, in situ measurements in agriculture need to be done in small localized areas. We have fabricated a multimodal sensor on a small Si chip in which a pH sensor was integrated with electrical conductivity (EC and temperature sensors. An ISFET with a Si3N4 membrane was used for the pH sensor. For the EC sensor, the electrical conductivity between platinum electrodes was measured, and the temperature sensor was a p-n junction diode. These are some of the most important measurements required for controlling the conditions in plant beds. The multimodal sensor can be inserted into a plant bed for in situ monitoring. To confirm the absence of crosstalk between the sensors, we made simultaneous measurements of pH, EC, and temperature of a pH buffer solution in a plant bed. When the solution was diluted with hot or cold water, the real time measurements showed changes to the EC and temperature, but no change in pH. We also demonstrated that our sensor was capable of simultaneous in situ measurements in rock wool without being affected by crosstalk.

  17. Assessment of Tandem Measurements of pH and Total Gut Transit Time in Healthy Volunteers

    OpenAIRE

    Mikolajczyk, Adam E; Watson, Sydeaka; Surma, Bonnie L; Rubin, David T

    2015-01-01

    Objectives: The variation of luminal pH and transit time in an individual is unknown, yet is necessary to interpret single measurements. This study aimed to assess the intrasubject variability of gut pH and transit time in healthy volunteers using SmartPill devices (Covidien, Minneapolis, MN). Methods: Each subject (n=10) ingested two SmartPill devices separated by 24?h. Mean pH values were calculated for 30?min after gastric emptying (AGE), before the ileocecal (BIC) valve, after the ileocec...

  18. Cross-linked self-assembled micelle based nanosensor for intracellular pH measurements

    DEFF Research Database (Denmark)

    Ek, Pramod Kumar; Søndergaard, Rikke Vicki; Windschiegl, Barbara

    2014-01-01

    A micelle based nanosensor was synthesized and investigated as a ratiometric pH sensor for use in measurements in living cells by fluorescent microscopy. The nanosensor synthesis was based on self-assembly of an amphiphilic triblock copolymer, which was chemically cross-linked after micelle......-linked by an amidation reaction using 3,6,9-trioxaundecandioic acid cross-linker. The cross-linked micelle was functionalized with two pH sensitive fluorophores and one reference fluorophore, which resulted in a highly uniform ratiometric pH nanosensor with a diameter of 29 nm. The use of two sensor fluorophores...... provided a sensor with a very broad measurement range that seems to be influenced by the chemical design of the sensor. Cell experiments show that the sensor is capable of monitoring the pH distributions in HeLa cells....

  19. Measuring interstitial pH and pO2 in mouse tumors.

    Science.gov (United States)

    Jain, Rakesh K; Munn, Lance L; Fukumura, Dai

    2013-07-01

    This protocol outlines methods to measure two extravascular parameters, interstitial pH and partial pressure of oxygen (pO2), in mouse tumors. The method for measuring interstitial pH uses fluorescence ratio imaging microscopy (FRIM) of the pH-sensitive fluorescent dye 2',7'-bis-(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF). The method for measuring interstitial pO2 is based on the oxygen-dependent quenching of the phosphorescence of albumin-bound palladium meso-tetra(4-carboxyphenyl)porphyrin, and can be used to measure microvascular as well as interstitial pO2. In addition, the two methods can be used sequentially to measure both pH and pO2 in the same tissues.

  20. Detection of irradiated peppers by viscosity measurement at extremely high pH

    International Nuclear Information System (INIS)

    Hayashi, Toru; Todoriki, Setsuko

    1996-01-01

    The viscosities of aqueous suspensions of irradiated peppers determined after heat gelatinization were influenced by the pH of the suspension to a greater degree than those of unirradiated ones. Viscosity measurement under an extremely alkaline condition (pH 13.8) resulted in a significant different between irradiated peppers and unirradiated ones, irrespective of the planting locality and storage period. All of the pepper samples irradiated at 5 kGy showed viscosity values significantly lower than unirradiated ones. (Author)

  1. Measurement of pH micro-heterogeneity in natural cheese matrices by fluorescence lifetime imaging

    OpenAIRE

    Zuzana eBurdikova; Zdenek eSvindrych; Jan ePala; Cian eHickey; Martin G. Wilkinson; Jiri ePanek; Mark A. E. Auty; Ammasi ePeriasamy; Jeremiah J. Sheehan

    2015-01-01

    Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level there remains a signi...

  2. Measurement of pH micro-heterogeneity in natural cheese matrices by flourescence lifetime imaging

    OpenAIRE

    Burdikova, Suzana; Svindrych, Zdenek; Pala, Jan; Hickey, Cian D; Wilkinson, Martin G.; Panek, Jiri; Auty, Mark A.E.; Periasamy, Ammasi; Sheehan, Jeremiah J.

    2015-01-01

    peer-reviewed Cheese, a product of microbial fermentation may be defined as a protein matrix entrapping fat, moisture, minerals and solutes as well as dispersed bacterial colonies. The growth and physiology of bacterial cells in these colonies may be influenced by the microenvironment around the colony, or alternatively the cells within the colony may modify the microenvironment (e.g., pH, redox potential) due to their metabolic activity. While cheese pH may be measured at macro level ther...

  3. Predicting and measurement of pH of seawater reverse osmosis concentrates

    KAUST Repository

    Waly, Tarek

    2011-10-01

    The pH of seawater reverse osmosis plants (SWRO) is the most influential parameter in determining the degree of supersaturation of CaCO3 in the concentrate stream. For this, the results of pH measurements of the concentrate of a seawater reverse osmosis pilot plant were compared with pH calculations based on the CO2-HCO3 --CO3 2- system equilibrium equations. Results were compared with two commercial software programs from membrane suppliers and also the software package Phreeqc. Results suggest that the real concentrate pH is lower than that of the feed and that none of the used programs was able to predict correctly real pH values. In addition, the effect of incorporating the acidity constant calculated for NaCl medium or seawater medium showed a great influence on the concentrate pH determination. The HCO3 - and CO3 2- equilibrium equation using acidity constants developed for seawater medium was the only method able to predict correctly the concentrate pH. The outcome of this study indicated that the saturation level of the concentrate was lower than previously anticipated. This was confirmed by shutting down the acid and the antiscalants dosing without any signs of scaling over a period of 12 months. © 2011 Elsevier B.V.

  4. Distributed plastic optical fibre measurement of pH using a photon counting OTDR

    International Nuclear Information System (INIS)

    Saunders, C; Scully, P J

    2005-01-01

    Distributed measurement of pH was demonstrated at a sensitised region 4m from the distal end of a 20m length of plastic optical fibre. The cladding was removed from the fibre over 150mm and the bare core was exposed to an aqueous solution of methyl red at three values of pH, between 2.89 and 9.70. The optical fibre was interrogated at 648nm using a Luciol photon counting optical time domain reflectometer, and demonstrated that the sensing region was attenuated as a function of pH. The attenuation varied from 16.3 dB at pH 2.89 to 8.6 dB at pH 9.70; this range equated to -1.13 ± 0.04 dB/pH. It is thus possible to determine both the position to ± 12mm and pH to an estimated ± 0.5pH at the sensing region

  5. Expanding the dynamic measurement range for polymeric nanoparticle pH sensors

    DEFF Research Database (Denmark)

    Sun, Honghao; Almdal, Kristoffer; Andresen, Thomas Lars

    2011-01-01

    Conventional optical nanoparticle pH sensors that are designed for ratiometric measurements in cells have been based on utilizing one sensor fluorophore and one reference fluorophore in each nanoparticle, which results in a relatively narrow dynamic measurement range. This results in substantial...

  6. A wireless pH sensor using magnetoelasticity for measurement of body fluid acidity.

    Science.gov (United States)

    Pang, Pengfei; Gao, Xianjuan; Xiao, Xilin; Yang, Wenyue; Cai, Qingyun; Yao, Shouzhuo

    2007-04-01

    The determination of body fluid acidity using a wireless magnetoelastic pH-sensitive sensor is described. The sensor was fabricated by casting a layer of pH-sensitive polymer on a magnetoelastic ribbon. In response to an externally applied time-varying magnetic field, the magnetoelastic sensor mechanically vibrates at a characteristic frequency that is inversely dependent upon the mass of the pH polymer film, which varies as the film swells and shrinks in response to pH. As the magnetoelastic sensor is magnetostrictive, the mechanical vibrations of the sensor launch magnetic flux that can be detected remotely using a pickup coil. The sensor can be used for direct measurements of body fluid acidity without a pretreatment of the sample by using a filtration membrane. A reversible and linear response was obtained between pH 5.0 and 8.0 with a measurement resolution of pH 0.1 and a slope of 0.2 kHz pH(-1). Since there are no physical connections between the sensor and the instrument, the sensor can be applied to in vivo and in situ monitoring of the physiological pH and its fluctuations.

  7. Drilling and associated drillhole measurements of the pilot hole ONK-PH11

    International Nuclear Information System (INIS)

    Karttunen, P.; Mancini, P.; Pekkanen, J.; Poellaenen, J.; Tarvainen, A.-M.; Toropainen, V.; Pere, T.

    2011-01-01

    The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are drillholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes are aimed to confirm the quality of the rock mass for tunnel construction, and in particular to identify water conductive fractured zones and to provide information that could result in modifications of the existing construction plans. The pilot hole ONK-PH11 was drilled from chainage 3922 to chainage 4053 in October 2009. The length of the hole is 131.21 metres. The aim during the drilling work was to orient core samples as much as possible. The deviation of the drillhole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Hydraulic conductivity of the fractures or fractured zones was measured by Posiva Flow Log equipment. During flow measurements also electric conductivity and temperature were measured. In flow logging test sections of 0.5 m and increments of 0.1 m were used. The water loss measurements were performed after drilling was completed by the drilling company. Logging of the core samples included the following parameters: lithology, foliation, fracturing, RQD, fractured zones, weathering and possible intersections. The rock mechanical logging was based on Q-classification. The rock strength and deformation were determined with Rock Tester -equipment. Geophysical logging and optical imaging of the pilot hole included the fieldwork of all surveys, the integration of the data as well as interpretation of the acoustic and drillhole radar data. The groundwater samples were collected from the open hole without any packers. The collected groundwater samples were

  8. pH tolerance in freshwater bacterioplankton: trait variation of the community as measured by leucine incorporation.

    Science.gov (United States)

    Bååth, Erland; Kritzberg, Emma

    2015-11-01

    pH is an important factor determining bacterial community composition in soil and water. We have directly determined the community tolerance (trait variation) to pH in communities from 22 lakes and streams ranging in pH from 4 to 9 using a growth-based method not relying on distinguishing between individual populations. The pH in the water samples was altered to up to 16 pH values, covering in situ pH ± 2.5 U, and the tolerance was assessed by measuring bacterial growth (Leu incorporation) instantaneously after pH adjustment. The resulting unimodal response curves, reflecting community tolerance to pH, were well modeled with a double logistic equation (mean R(2) = 0.97). The optimal pH for growth (pHopt) among the bacterial communities was closely correlated with in situ pH, with a slope (0.89 ± 0.099) close to unity. The pH interval, in which growth was ≥90% of that at pHopt, was 1.1 to 3 pH units wide (mean 2.0 pH units). Tolerance response curves of communities originating from circum-neutral pH were symmetrical, whereas in high-pH (8.9) and especially in low-pH (pH waters, decreasing pH was more detrimental for bacterial growth than increasing pH, with a tendency for the opposite for high-pH waters. A pH tolerance index, using the ratio of growth at only two pH values (pH 4 and 8), was closely related to pHopt (R(2) = 0.83), allowing for easy determination of pH tolerance during rapid changes in pH. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. 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

  10. Measuring pH variability using an experimental sensor on an underwater glider

    Directory of Open Access Journals (Sweden)

    M. P. Hemming

    2017-05-01

    Full Text Available Autonomous underwater gliders offer the capability of measuring oceanic parameters continuously at high resolution in both vertical and horizontal planes, with timescales that can extend to many months. An experimental ion-sensitive field-effect transistor (ISFET sensor measuring pH on the total scale was attached to a glider during the REP14-MED experiment in June 2014 in the Sardinian Sea in the northwestern Mediterranean. During the deployment, pH was sampled at depths of up to 1000 m along an 80 km transect over a period of 12 days. Water samples were collected from a nearby ship and analysed for dissolved inorganic carbon concentration and total alkalinity to derive the pH for validating the ISFET sensor measurements. The vertical resolution of the pH sensor was good (1 to 2 m, but stability was poor and the sensor drifted in a non-monotonous fashion. In order to remove the sensor drift, a depth-constant time-varying offset was applied throughout the water column for each dive, reducing the spread of the data by approximately two-thirds. Furthermore, the ISFET sensor required temperature- and pressure-based corrections, which were achieved using linear regression. Correcting for this decreased the apparent sensor pH variability by a further 13 to 31 %. Sunlight caused an apparent sensor pH decrease of up to 0.1 in surface waters around local noon, highlighting the importance of shielding the sensor from light in future deployments. The corrected pH from the ISFET sensor is presented along with potential temperature, salinity, potential density anomalies (σθ, and dissolved oxygen concentrations (c(O2 measured by the glider, providing insights into the physical and biogeochemical variability in the Sardinian Sea. The pH maxima were identified close to the depth of the summer chlorophyll maximum, where high c(O2 values were also found. Longitudinal pH variations at depth (σθ > 28. 8 kg m−3 highlighted the variability of

  11. Measurement of peritoneal fluid pH in patients with non-serosal invasive gastric cancer.

    Science.gov (United States)

    Noh, Seung Moo

    2003-02-01

    The accurate pH range of peritoneal fluid is clinically valuable for the evaluation of some pathological conditions of the body, however, it is not easy to measure in healthy individuals. The aim of this study was to measure; pH, pCO2, pO2, Na+, K++, Ca++, HCO3-, and O2 saturation of the peritoneal fluid in patients with non-serosal invasive gastric cancer. One hundred and thirty four patients (86 men and 48 women), ranging in age from 24 to 91 years were enrolled in this study. After opening the abdominal wall, the probe of a portable pH meter was placed in the peritoneal fluid in the subhepatic space. In addition, I collected the peritoneal fluid from the subhepatic space to measure, pH, pCO2, pO2, Na+, K++, Ca++, HCO3-, and O2 saturation using an autoanalyzer. The pHs of the peritoneal fluids tested has a mean of 7.73 (range 7.46 - 8.10), and the other parameters were pCO2, 22.81 mmHg; pO2, 136.49 mmHg; Na+, 146.57 mmol/L; K++, 4.80 mmol/L; Ca++, 0.89 mmol/L; HCO3-, 30.54 mmol/L, and O2 saturation, 99.74%. This study describes a practical method of measuring the pH of peritoneal fluid. The result obtained reflects the normal adult peritoneal pH value, which I propose as a reference value.

  12. Live-cell Microscopy and Fluorescence-based Measurement of Luminal pH in Intracellular Organelles

    Directory of Open Access Journals (Sweden)

    Li Ma

    2017-08-01

    Full Text Available Luminal pH is an important functional feature of intracellular organelles. Acidification of the lumen of organelles such as endosomes, lysosomes, and the Golgi apparatus plays a critical role in fundamental cellular processes. As such, measurement of the luminal pH of these organelles has relevance to both basic research and translational research. At the same time, accurate measurement of intraorganellar pH in living cells can be challenging and may be a limiting hurdle for research in some areas. Here, we describe three powerful methods to measure rigorously the luminal pH of different intracellular organelles, focusing on endosomes, lysosomes, and the Golgi apparatus. The described methods are based on live imaging of pH-sensitive fluorescent probes and include: (1 A protocol based on quantitative, ratiometric measurement of endocytosis of pH-sensitive and pH-insensitive fluorescent conjugates of transferrin; (2 A protocol for the use of proteins tagged with a ratiometric variant of the pH-sensitive intrinsically fluorescent protein pHluorin; and (3 A protocol using the fluorescent dye LysoSensor™. We describe necessary reagents, key procedures, and methods and equipment for data acquisition and analysis. Examples of implementation of the protocols are provided for cultured cells derived from a cancer cell line and for primary cultures of mouse hippocampal neurons. In addition, we present strengths and weaknesses of the different described intraorganellar pH measurement methods. These protocols are likely to be of benefit to many researchers, from basic scientists to those conducting translational research with a focus on diseases in patient-derived cells.

  13. Spectrophotometric high-precision seawater pH determination for use in underway measuring systems

    Directory of Open Access Journals (Sweden)

    S. Aßmann

    2011-10-01

    Full Text Available Autonomous sensors are required for a comprehensive documentation of the changes in the marine carbon system and thus to differentiate between its natural variability and anthropogenic impacts. Spectrophotometric determination of pH – a key variable of the seawater carbon system – is particularly suited to achieve precise and drift-free measurements. However, available spectrophotometric instruments are not suitable for integration into automated measurement systems (e.g. FerryBox since they do not meet the major requirements of reliability, stability, robustness and moderate cost. Here we report on the development and testing of a~new indicator-based pH sensor that meets all of these requirements. This sensor can withstand the rough conditions during long-term deployments on ships of opportunity and is applicable to the open ocean as well as to coastal waters with a complex matrix and highly variable conditions. The sensor uses a high resolution CCD spectrometer as detector connected via optical fibers to a custom-made cuvette designed to reduce the impact of air bubbles. The sample temperature can be precisely adjusted (25 °C ± 0.006 °C using computer-controlled power supplies and Peltier elements thus avoiding the widely used water bath. The overall setup achieves a measurement frequency of 1 min−1 with a precision of ±0.0007 pH units, an average offset of +0.0005 pH units to a reference system, and an offset of +0.0081 pH units to a certified standard buffer. Application of this sensor allows monitoring of seawater pH in autonomous underway systems, providing a key variable for characterization and understanding of the marine carbon system.

  14. pH Tolerance in Freshwater Bacterioplankton: Trait Variation of the Community as Measured by Leucine Incorporation

    OpenAIRE

    Bååth, Erland; Kritzberg, Emma

    2015-01-01

    pH is an important factor determining bacterial community composition in soil and water. We have directly determined the community tolerance (trait variation) to pH in communities from 22 lakes and streams ranging in pH from 4 to 9 using a growth-based method not relying on distinguishing between individual populations. The pH in the water samples was altered to up to 16 pH values, covering in situ pH ± 2.5 U, and the tolerance was assessed by measuring bacterial growth (Leu incorporation) in...

  15. pH homeostasis in Escherichia coli: measurement by 31P nuclear magnetic resonance of methylphosphonate and phosphate

    International Nuclear Information System (INIS)

    Slonczewski, J.L.; Rosen, B.P.; Alger, J.R.; Macnab, R.M.

    1981-01-01

    The intracellular pH of Escherichia coli cells, respiring on endogenous energy sources, was monitored continuously by 31 P NMR over an extracellular pH range between 5.5 and 9. pH homeostasis was found to be good over the entire range, with the data conforming to the simple relationship intracellular pH = 7.6 + 0.1(external pH - 7.6) so that the extreme values observed for intracellular pH were 7.4 and 7.8 external pH 5.5 and 9, respectively. As well as inorganic phosphate, we employed the pH-sensitive NMR probe methylphosphonate, which was taken up by glycerol-grown cells and was nontoxic; its pK/sub a/ of 7.65 made it an ideal probe for measurement of cytoplasmic pH and alkaline external pH

  16. Sol gel based fiber optic sensor for blook pH measurement

    International Nuclear Information System (INIS)

    Grant, S. A.; Glass, R. S.

    1996-01-01

    This paper describes a fiber-optic pH sensor based upon sol-gel encapsulation of a self-referencing dye, seminaphthorhodamine-1 carboxylate (SNARF-1C). The simple sol-gel fabrication procedure and low coating leachability are ideal for encapsulation and immobilization of dye molecules onto the end of an optical fiber. A miniature bench-top fluorimeter system was developed for use with the optical fiber to obtain pH measurements. Linear and reproducible responses were obtained in human blood in the pH range 6.8 to 8.0, which encompasses the clinically-relevant range. Therefore, this sensor can be considered for in vivo use

  17. Drilling and associated Drillhole measurements of the Pilot Hole ONK-PH14

    International Nuclear Information System (INIS)

    Aalto, P.; Toropainen, V.; Tarvainen, A.-M.; Pekkanen, J.; Poellaenen, J.; Lamminmaeki, T.

    2011-09-01

    The construction of ONKALO access tunnel started in September 2004 at Olkiluoto. During the construction, investigations serving both research and construction purposes need to be done. Investigations can be done for example in so called pilot holes. Pilot holes are cored drillholes to be drilled to the tunnel profile. The length of the holes varies from some tens of metres to some hundreds of metres. The purpose of the holes is to confirm the quality of the rock mass for tunnel construction, especially to identify water conductive fractures/fractured zones and to provide information that could result in modifications of the existing construction plans. The pilot hole ONK-PH14 was drilled in June 2010. Drilling was started in chainage 4313.6. The length of the hole was 150.80 metres. The deviation of the drillhole was measured during and after the drilling. Additionally, oriented core samples were collected from the drill core and the electric conductivity of returning water was measured. Logging of the core samples included following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The strength and deformation properties of the rock were defined by using Rock-Tester equipment. Hydraulic measurements were made by using the PFL DIFF (Posiva Flow log, Difference Flow Method). PFL DIFF measurements were performed with a 0.5 m section length and with 0.1 m length increments. With PFL DIFF tool the locations of transmissive fractures were detected. Simultaneously, the electric conductivity (EC) of the drillhole water and fracture specific water, temperature of the drillhole water, single point resistance (SPR) of the drillhole wall and the prevailing water pressure were measured. Water loss measurements were done after the drilling by the tool developed by Posiva. The tool was in test use during the measurements. The groundwater sample was

  18. Drilling and associated Drillhole measurements of the Pilot Hole ONK-PH14

    Energy Technology Data Exchange (ETDEWEB)

    Aalto, P. (ed.); Lahti, M.; Kosunen, P.; Pere, T. [Posiva Oy, Helsinki (Finland); Toropainen, V.; Tarvainen, A.-M. [Suomen Malmi Oy, Espoo (Finland); Pekkanen, J.; Poellaenen, J. [Poeyry Finland Oy, Espoo (Finland); Lamminmaeki, T. [Teollisuuden Voima Oyj, Helsinki (Finland)

    2011-08-15

    The construction of ONKALO access tunnel started in September 2004 at Olkiluoto. During the construction, investigations serving both research and construction purposes need to be done. Investigations can be done for example in so called pilot holes. Pilot holes are cored drillholes to be drilled to the tunnel profile. The length of the holes varies from some tens of metres to some hundreds of metres. The purpose of the holes is to confirm the quality of the rock mass for tunnel construction, especially to identify water conductive fractures/fractured zones and to provide information that could result in modifications of the existing construction plans. The pilot hole ONK-PH14 was drilled in June 2010. Drilling was started in chainage 4313.6. The length of the hole was 150.80 metres. The deviation of the drillhole was measured during and after the drilling. Additionally, oriented core samples were collected from the drill core and the electric conductivity of returning water was measured. Logging of the core samples included following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The strength and deformation properties of the rock were defined by using Rock-Tester equipment. Hydraulic measurements were made by using the PFL DIFF (Posiva Flow log, Difference Flow Method). PFL DIFF measurements were performed with a 0.5 m section length and with 0.1 m length increments. With PFL DIFF tool the locations of transmissive fractures were detected. Simultaneously, the electric conductivity (EC) of the drillhole water and fracture specific water, temperature of the drillhole water, single point resistance (SPR) of the drillhole wall and the prevailing water pressure were measured. Water loss measurements were done after the drilling by the tool developed by Posiva. The tool was in test use during the measurements. The groundwater sample was

  19. Drilling and the associated borehole measurements of the pilot hole ONK-PH2

    International Nuclear Information System (INIS)

    Oehberg, A.; Aaltonen, I.; Kemppainen, K.; Mattila, J.; Heikkinen, E.; Lahti, M.; Pussinen, V.; Niemonen, J.; Paaso, N.; Rouhiainen, P.

    2005-11-01

    The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are boreholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes will mostly aim to confirm the quality of the rock mass for tunnel construction, and in particular at identifying water conductive fractured zones and at providing information that could result in modifications of the existing construction plans. The pilot hole ONK-PH2 was drilled in December 2004. The length of the borehole is about 122 metres. The aim during the drilling work was to orientate core samples as much as possible. The deviation of the borehole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The tests to determine rock strength and deformation properties were made with a Rock Tester-equipment. Difference Flow method was used for the determination of hydraulic conductivity and hydraulic head in fractures and fractured zones in the borehole. The overlapping i.e. the detailed flow logging mode was used. The flow logging was performed with 0.5 m section length and with 0.1 m depth increments. Geophysical borehole logging and optical imaging surveys of the pilot hole PH2 included the field work of all the surveys, the integration of the data as well as interpretation of the acoustic and borehole radar data. One of the objectives of the geochemical study was to get information of composition of ONKALO's groundwater before the construction will

  20. Drilling and the associated drillhole measurements of the pilot hole ONK-PH4

    International Nuclear Information System (INIS)

    Oehberg, A.; Heikkinen, E.; Hirvonen, H.; Kemppainen, K.; Majapuro, J.; Niemonen, J.; Poellaenen, J.; Rouhiainen, P.; Rautio, T.

    2006-09-01

    The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are drillholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes are mostly aimed to confirm the quality of the rock mass for tunnel construction, and in particular to identify water conductive fractured zones and to provide information that could result in modifications of the existing construction plans. The pilot hole ONK-PH4 was drilled in October 2005. The length of the hole is 96.01 metres. During the drilling work core samples were oriented as much as possible. The deviation of the hole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Geological logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The tests to determine rock strength and deformation properties were made with a Rock Tester-equipment. Difference Flow method was used for the determination of hydraulic conductivity in fractures and fractured zones in the hole. The overlapping i.e. the detailed flow logging mode was used. The flow logging was performed with 0.5 m section length and with 0.1 m depth increment. Water loss tests (Lugeon tests) were used to give background information for the grouting design. Geophysical logging and optical imaging of the pilot hole PH4 included the field work of all surveys, the integration of the data as well as interpretation of the acoustic and drillhole radar data. One of the objectives of the geochemical study was to get information of composition of ONKALO

  1. Drilling and the associated borehole measurements of the pilot hole ONK-PH3

    International Nuclear Information System (INIS)

    Oehberg, A.; Heikkinen, E.; Hirvonen, H.; Kemppainen, K.; Majapuro, J.; Niemonen, J.; Poellaenen, J.; Rouhiainen, P.

    2006-03-01

    The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are boreholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes will mostly aim to confirm the quality of the rock mass for tunnel construction, and in particular at identifying water conductive fractured zones and at providing information that could result in modifications of the existing construction plans. The pilot hole ONK-PH3 was drilled in September 2005. The length of the borehole is 145.04 metres. The aim during the drilling work was to orientate core samples as much as possible. The deviation of the borehole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The tests to determine rock strength and deformation properties were made with a Rock Tester-equipment. Difference Flow method was used for the determination of hydraulic conductivity in fractures and fractured zones in the borehole. The overlapping i.e. the detailed flow logging mode was used. The flow logging was performed with 0.5 m section length and with 0.1 m depth increments. Water loss tests (Lugeon tests) and a pressure build-up test were used to give background information for the grouting design. Geophysical borehole logging and optical imaging surveys of the pilot hole PH3 included the field work of all the surveys, the integration of the data as well as interpretation of the acoustic and borehole radar data. One of the objectives of the

  2. A hydrogel based nanosensor with an unprecedented broad sensitivity range for pH measurements in cellular compartments

    DEFF Research Database (Denmark)

    Zhang, M.; Søndergaard, Rikke Vicki; Ek, Pramod Kumar

    2015-01-01

    Optical pH nanosensors have been applied for monitoring intracellular pH in real-time for about two decades. However, the pH sensitivity range of most nanosensors is too narrow, and measurements that are on the borderline of this range may not be correct. Furthermore, ratiometric measurements...... of acidic intracellular pH (pH sensor, a fluorophore based nanosensor, with an unprecedented broad measurement range from pH 1.4 to 7.0. In this nanosensor, three p......H-sensitive fluorophores (difluoro-Oregon Green, Oregon Green 488, and fluorescein) and one pH-insensitive fluorophore (Alexa 568) were covalently incorporated into a nanoparticle hydrogel matrix. With this broad range quadruple-labelled nanosensor all physiological relevant pH levels in living cells can be measured...

  3. Titration and Spectroscopic Measurements of Poultry Litter pH Buffering Capacity.

    Science.gov (United States)

    Cassity-Duffey, Kate; Cabrera, Miguel; Mowrer, Jake; Kissel, David

    2015-07-01

    The pH value of poultry litter is affected by nitrification, mineralization, and the addition of acidifying chemicals, all acting on the poultry litter pH buffering capacity (pHBC). Increased understanding of poultry litter pHBC will aid in modeling NH volatilization from surface-applied poultry litter as well as estimating rates of alum applications. Our objectives were to (i) determine the pHBC of a wide range of poultry litters; (ii) assess the accuracy of near-infrared reflectance spectroscopy (NIRS) for determining poultry litter pHBC; and (iii) demonstrate the use of poultry litter pHBC to increase the accuracy of alum additions. Litter pHBC was determined by titration and calculated from linear and sigmoidal curves. For the 37 litters measured, linear pHBC ranged from 187 to 537 mmol (pH unit) kg dry litter. The linear and sigmoidal curves provided accurate predictions of pHBC, with most > 0.90. Results from NIRS analysis showed that the linear pHBC expressed on an "as is" water content basis had a NIRS coefficient of calibration (developed using a modified partial least squares procedure) of 0.90 for the 37 poultry litters measured. Using the litter pHBC, an empirical model was derived to determine the amount of alum needed to create a target pH. The model performed well in the range of pH 6.5 to 7.5 (RMSE = 0.07) but underpredicted the amount of alum needed to reach pH litter, which prevented its hydrolysis. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  4. Difference flow measurements and hydraulic interference test in ONKALO at Olkiluoto drillholes ONK-PH16 and ONK-PH17

    Energy Technology Data Exchange (ETDEWEB)

    Komulainen, J.; Pekkanen, J. [Poyry Finland Oy, Espoo (Finland)

    2012-08-15

    The Posiva Flow Log, Difference Flow Method (PFL DIFF) uses a flowmeter that incorporates a flow guide and can be used for relatively quick determinations of hydraulic conductivity and hydraulic head in fractures/fractured zones in cored drillholes. This report presents the principles of the method as well as the results of the measurements carried out in the underground facilities of ONKALO. The measurements were conducted in pilot holes ONK-PH16 and ONK-PH17 between October 12 and December 29, 2010. The aim of the measurements was to detect water conducting fractures and hydraulic interference between pilot holes ONK-PH16 and ONK-PH17. The flow rate into a 0.5 m long test section was measured using 0.1 m point intervals. The flowing fractures in both pilot holes were obtained between 50 m - 80 m. For hydraulic interference test one drillhole was closed with packers to increase its pressure. Flow response to the increased pressure was measured in the other drillhole. The flow guide of the PFL DIFF probe encloses an electrode for single point resistance measurement, which was carried out with 0.01 m point intervals during the automatic flow measurements. The flow measurement and the single point resistance measurement were used to locate flowing fractures and evaluate their transmissivity. Electrical conductivity (EC) and temperature of water were registered during automatic flow logging. The conductivity values are temperature corrected to 25 deg C. The distance between the drillholes is about 14 m. Flow response in fractures of open ONK-PH16 could be detected when pressure was changed in ONK-PH17. (orig.)

  5. Drilling and associated drillhole measurements of the pilot hole ONK-PH9

    International Nuclear Information System (INIS)

    Karttunen, P.; Pekkanen, J.; Poellaenen, J.; Tarvainen, A.-M.; Toropainen, V.; Lamminmaeki, T.; Kosunen, P.

    2010-01-01

    The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are drillholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes are aimed to confirm the quality of the rock mass for tunnel construction, and in particular to identify water conductive fractured zones and to provide information that could result in modifications of the existing construction plans. The pilot hole ONK-PH9 was drilled from chainage 3263 to chainage 3413.27 in November 2008. The length of the hole is 150.3 metres. The aim during the drilling work was to orient core samples as much as possible. The deviation of the drillhole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Hydraulic conductivity of the fractures or fractured zones was measured by Posiva Flow Log equipment. The measurements were done in two phases. During flow measurements also electric conductivity, grounding resistance and temperature were measured. In flow logging test sections of 0.5 m and increments of 0.1 m were used. The water loss measurements were performed after drilling was completed by the drilling company. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss, and weathering. The rock mechanical logging was based on Q-classification. The rock strength and deformation were determined with Rock Tester equipment. Geophysical logging and optical imaging of the pilot hole included the fieldwork of all surveys, the integration of the data as well as interpretation of the acoustic and drillhole radar data. One of the objectives of the geochemical study

  6. Drilling and associated drillhole measurements of the pilot hole ONK-PH10

    International Nuclear Information System (INIS)

    Mancini, P.; Karttunen, P.; Lokkila, M.; Pekkanen, J.; Poellaenen, J.; Tarvainen, A.-M.; Toropainen, V.; Kosunen, P.; Pere, T.

    2010-08-01

    The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are drillholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes are aimed to confirm the quality of the rock mass for tunnel construction, and in particular to identify water conductive fractured zones and to provide information that could result in modifications of the existing construction plans. The pilot hole ONK-PH10 was drilled from chainage 3459 to chainage 3639 in March 2009. The length of the hole is 180.00 metres. The drilling was done as orientated core drilling. The deviation of the drillhole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss, and weathering. The rock mechanical logging was based on Q-classification. The test to determine rock strength and deformation were made with Rock Tester -equipment. Water conductivity of the fractures or fractured zones was measured by Posiva Flow Log equipment. The measurements were done in two phases. During flow measurements also grounding resistance electric conductivity and temperature were measured. In flow logging test, sections of 0.5 m with increments of 0.1 m were used. Water loss measurements were conducted in the hole section 3.70-180.00 m dhd. Geophysical logging and optical imaging of the pilot hole included the fieldwork of all surveys, the integration of the data as well as interpretation of the acoustic and drillhole radar data. One of the objectives of the geochemical study was to get information of the composition of

  7. Drilling and the associated drillhole measurements of the pilot hole ONK-PH8

    International Nuclear Information System (INIS)

    Karttunen, P.; Poellaenen, J.; Rautio, T.; Tarvainen, A.-M.; Lamminmaeki, T.; Kemppainen, K.; Kosunen, P.; Lampinen, H.

    2009-02-01

    The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are drillholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes are aimed to confirm the quality of the rock mass for tunnel construction, and in particular to identify water conductive fractured zones and to provide information that could result in modifications of the existing construction plans. The pilot hole ONK-PH8 was drilled from chainage 3116 to chainage 3266.29 in June- July 2008. The length of the hole is 150.29 metres. The aim during the drilling work was to orient core samples as much as possible. The deviation of the drillhole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Water conductivity of the fractures or fractured zones was measured by Posiva Flow Log equipment. The measurements were done in two phases. During flow measurements also grounding resistance, electric conductivity and temperature were measured. In flow logging test sections of 0.5 m and increments of 0.1 m were used. The water loss measurements failed. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss, and weathering. The rock mechanical logging was based on Q-classification. The test to determine rock strength and deformation were made with Rock Tester-equipment. Geophysical logging and optical imaging of the pilot hole included the fieldwork of all surveys, the integration of the data as well as interpretation of the acoustic and drillhole radar data. One of the objectives of the geochemical study was to get information of the composition of ONKALO

  8. Ex vivo Porcine Model to Measure pH Dependence of gagCEST in the Inter-Vertebral Disc

    Science.gov (United States)

    Melkus, Gerd; Grabau, Michelle; Karampinos, Dimitrios C.; Majumdar, Sharmila

    2013-01-01

    Purpose Studies have linked low pH and loss of glycosaminoglycan (GAG) in the intervertebral discs (IVDs) of patients with discogenic back pain. The purpose of the present study is to determine whether the chemical exchange saturation transfer (CEST) effect of GAG (gagCEST) is pH-dependent and whether it can be used to detect pH changes in IVD specimens. Iopromide, a FDA approved agent for CT/X-Ray, was also evaluated as a pH-sensitive CEST probe to explore the agents’ potential to measure IVD pH. Methods The pH dependency of the CEST effect of chondroitin sulfate (containing GAG) and Iopromide phantoms was investigated at 7 T. Z-spectra from porcine IVD specimens were acquired before and after manipulating the pH with sodium lactate. Iopromide was injected into the specimens and the calibration curve was used to determine the pH status. Results Chondroitin sulfate showed a non-linear dependence of gagCEST effect with pH and gagCEST signal differences were detected in the specimens. The CEST effect of Iopromide resulted in a sigmoidal relation with pH and was used to measure pH. Conclusion gagCEST is sensitive to pH and enables investigation of the IVD pH status. Iopromide CEST is independent of the local GAG concentration and has the potential for measuring pH in the IVD. PMID:23818244

  9. Measurement of brain pH using 11CO2 and positron emission tomography

    International Nuclear Information System (INIS)

    Buxton, R.B.; Wechsler, L.R.; Alpert, N.M.; Ackerman, R.H.; Elmaleh, D.R.; Correia, J.A.

    1984-01-01

    We have examined the feasibility of measuring local brain pH in vivo with 11 CO 2 and positron emission tomography. In particular, we have addressed two objections that have been raised against this method: the assumed need to estimate local tissue PCO 2 and the rapid fixation of 11 C in tissue. From a reexamination of the basic theory, we argue that after administration of 11 CO 2 the time-dependent distribution of 11 C between tissue and blood is independent of the distribution of CO 2 already in the body, making it unnecessary to estimate local tissue PCO 2 . Assuming that the blood--brain barrier is impermeable to bicarbonate ions, there will be equal partial pressures of 11 CO 2 in blood and tissue at equilibrium. To overcome the problem of fixation in the tissue we have developed a kinetic model of the time-dependent distribution of 11 C that accounts for regional variations in blood flow, CO 2 extraction, pH, and rate of fixation. The values of the model parameters can be estimated from sequential measurements of tissue activity concentration during administration of 11 CO 2 . Tissue pH can then be calculated from one of the parameter values, a measurement of arterial pH, and known constants. Numerical calculations based on the kinetic model with assumed values of the parameters were used to optimize the experimental design. The calculations show that problems with fixation are much less severe with continuous infusion of activity than with bolus administration. During infusion the tissue curve depends strongly on tissue pH but only weakly on the rate of fixation

  10. Microfabricated Collector-Generator Electrode Sensor for Measuring Absolute pH and Oxygen Concentrations.

    Science.gov (United States)

    Dengler, Adam K; Wightman, R Mark; McCarty, Gregory S

    2015-10-20

    Fast-scan cyclic voltammetry (FSCV) has attracted attention for studying in vivo neurotransmission due to its subsecond temporal resolution, selectivity, and sensitivity. Traditional FSCV measurements use background subtraction to isolate changes in the local electrochemical environment, providing detailed information on fluctuations in the concentration of electroactive species. This background subtraction removes information about constant or slowly changing concentrations. However, determination of background concentrations is still important for understanding functioning brain tissue. For example, neural activity is known to consume oxygen and produce carbon dioxide which affects local levels of oxygen and pH. Here, we present a microfabricated microelectrode array which uses FSCV to detect the absolute levels of oxygen and pH in vitro. The sensor is a collector-generator electrode array with carbon microelectrodes spaced 5 μm apart. In this work, a periodic potential step is applied at the generator producing transient local changes in the electrochemical environment. The collector electrode continuously performs FSCV enabling these induced changes in concentration to be recorded with the sensitivity and selectivity of FSCV. A negative potential step applied at the generator produces a transient local pH shift at the collector. The generator-induced pH signal is detected using FSCV at the collector and correlated to absolute solution pH by postcalibration of the anodic peak position. In addition, in oxygenated solutions a negative potential step at the generator produces hydrogen peroxide by reducing oxygen. Hydrogen peroxide is detected with FSCV at the collector electrode, and the magnitude of the oxidative peak is proportional to absolute oxygen concentrations. Oxygen interference on the pH signal is minimal and can be accounted for with a postcalibration.

  11. Fetal short time variation during labor: a non-invasive alternative to fetal scalp pH measurements?

    OpenAIRE

    Schiermeier, Sven; Reinhard, Joscha; Hatzmann, Hendrike; Zimmermann, Ralf C.; Westhof, Gregor

    2009-01-01

    Objective: To determine whether short time variation (STV) of fetal heart beat correlates with scalp pH measurements during labor. Patients and methods: From 1279 deliveries, 197 women had at least one fetal scalp pH measurement. Using the CTG-Player®, STVs were calculated from the electronically saved cardiotocography (CTG) traces and related to the fetal scalp pH measurements. Results: There was no correlation between STV and fetal scalp pH measurements (r=−0.0592). Conclusions: Fetal ST...

  12. Solid State Sensor for Simultaneous Measurement of Total Alkalinity and pH of Seawater.

    Science.gov (United States)

    Briggs, Ellen M; Sandoval, Sergio; Erten, Ahmet; Takeshita, Yuichiro; Kummel, Andrew C; Martz, Todd R

    2017-09-22

    A novel design is demonstrated for a solid state, reagent-less sensor capable of rapid and simultaneous measurement of pH and Total Alkalinity (A T ) using ion sensitive field effect transistor (ISFET) technology to provide a simplified means of characterization of the aqueous carbon dioxide system through measurement of two "master variables": pH and A T . ISFET-based pH sensors that achieve 0.001 precision are widely used in various oceanographic applications. A modified ISFET is demonstrated to perform a nanoliter-scale acid-base titration of A T in under 40 s. This method of measuring A T , a Coulometric Diffusion Titration, involves electrolytic generation of titrant, H + , through the electrolysis of water on the surface of the chip via a microfabricated electrode eliminating the requirement of external reagents. Characterization has been performed in seawater as well as titrating individual components (i.e., OH - , HCO 3 - , CO 3 2- , B(OH) 4 - , PO 4 3- ) of seawater A T . The seawater measurements are consistent with the design in reaching the benchmark goal of 0.5% precision in A T over the range of seawater A T of ∼2200-2500 μmol kg -1 which demonstrates great potential for autonomous sensing.

  13. Measuring efficiency of university-industry Ph.D. projects using best worst method.

    Science.gov (United States)

    Salimi, Negin; Rezaei, Jafar

    A collaborative Ph.D. project, carried out by a doctoral candidate, is a type of collaboration between university and industry. Due to the importance of such projects, researchers have considered different ways to evaluate the success, with a focus on the outputs of these projects. However, what has been neglected is the other side of the coin-the inputs. The main aim of this study is to incorporate both the inputs and outputs of these projects into a more meaningful measure called efficiency. A ratio of the weighted sum of outputs over the weighted sum of inputs identifies the efficiency of a Ph.D. The weights of the inputs and outputs can be identified using a multi-criteria decision-making (MCDM) method. Data on inputs and outputs are collected from 51 Ph.D. candidates who graduated from Eindhoven University of Technology. The weights are identified using a new MCDM method called Best Worst Method (BWM). Because there may be differences in the opinion of Ph.D. candidates and supervisors on weighing the inputs and outputs, data for BWM are collected from both groups. It is interesting to see that there are differences in the level of efficiency from the two perspectives, because of the weight differences. Moreover, a comparison between the efficiency scores of these projects and their success scores reveals differences that may have significant implications. A sensitivity analysis divulges the most contributing inputs and outputs.

  14. PH measurement under pressure and at high temperatures; Mesure du pH sous pression et a temperature elevee

    Energy Technology Data Exchange (ETDEWEB)

    Fournie, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Le Peintre, M; Mahieu, C [Centre National de la Recherche Scientifique (CNRS), 91 - Gif-sur-Yvette (France)

    1961-07-01

    In the first part the development and operation of a glass electrode under pressure at room temperature is described. The pressure equilibrium between the inside and outside of the glass membrane several centimetres thick is obtained instantaneously by means of a siphon. The use of a silicone oil as electrical insulator makes possible the working of the glass electrode with the siphon at high pressures (100 kg/cm{sup 2}). In the second part, we determined the pH of various buffer solutions up to 250 deg. C using a cell of our design having two hydrogen electrodes. The values thus obtained for the buffer solutions make it possible to verify and calibrate the pH electrodes independently of the oxido-reduction potential of the medium. In the third part we give the results obtained up to 200 deg. C with the glass electrodes developed in conjunction with the Societe St Gobain. (author) [French] Dans une premiere partie, nous exposons la mise au point et le fonctionnement d'une electrode en verre sous pression a la temperature ordinaire. L'equilibrage instantane de la pression a l'interieur et a l'exterieur de la membrane en verre de quelques diziemes de millimetres d'epaisseur s'effectue par l'intermediaire d'un siphon. L'emploi d'une huile de silicone comme isolant electrique a permis le fonctionnement de l'electrode en verre a siphon sous haute pression (1000 kg/cm{sup 2}). Dans une deuxieme partie, nous avons determine jusqu'a 250 deg. C les valeurs du pH des diverses solutions tampons avec une cellule de notre conception a deux electrodes d'hydrogene. Les valeurs des solutions tampons ainsi obtenues permettent de verifier et d'etalonner les electrodes a pH independantes du potentiel d'oxydo-reduction du milieu. Dans une troisieme partie, nous relatons les resultats obtenus jusqu'a 200 deg. C avec les electrodes en verre mis au point en collaboration avec la Societe Saint-Gobain. (auteur)

  15. Drilling and the associated drillhole measurements of the pilot hole ONK-PH7

    International Nuclear Information System (INIS)

    Oehberg, A.; Kemppainen, K.; Lampinen, H.; Niemonen, J.; Poelloenen, J.; Rouhiainen, P.; Rautio, T.; Tarvainen, A.-M.

    2007-12-01

    The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are drillholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes are aimed to confirm the quality of the rock mass for tunnel construction, and in particular to identify water conductive fractured zones and to provide information that could result in modifications of the existing construction plans. The pilot hole ONK-PH7 was drilled from chainage 1880 to chainage 1980.31 in February 2007. The length of the hole is 100.31 m. The aim during the drilling work was to orient core samples as much as possible. The deviation of the drillhole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The tests to determine rock strength and deformation properties were made with a Rock Tester-equipment. Difference Flow method was used for the determination of hydraulic conductivity in fractures and fractured zones in the drillhole. The overlapping i.e. the detailed flow logging mode was used. Besides flow logging Single Point Resistance (SPR), Electric Conductivity (EC) and temperature of the drillhole water were also measured. The flow logging was performed with 0.5 m section length and with 0.1 m depth increment. Water loss measurements were conducted between the hole depth of 1.18 m and the hole bottom. Geophysical logging and optical imaging of the pilot hole included the fieldwork of all surveys, the integration of the data as

  16. Determination of very small contents of boron by pH difference measurement

    International Nuclear Information System (INIS)

    Boehm, H.; Kirmse, E.M.; Schilbach, U.

    1983-01-01

    For the determination of boron as a trace element for food of plants in a very complicated salt matrix an analytical proceeding was developed, which allows to determine the content of boron without separation. The principle of analysis is based on the esterification of boric acid with a multivalent alcohol, which leeds to a monovalent strong complex acid. The change of the pH value of the analysing solution is measured. From the initial pH number, the end pH number, the volume of the analysing solution and the ionic product of water corresponding with the operating temperature the quantity of boric acid of boron that is equivalent the produced quantity of H + -ions is calculated by means of a linear program. The standard deviation of analytical proceeding amounts to 13.9 ng B. For the determination of the contents of boron of an unknown sample, five to ten separate measurements are carried out. For solutions, which are about 1x10 -6 M of boric acid, there are necessary 10 ml of sample for each separate measurement. The confidence interval of analytical results is found to be between +- 0.5 and +- 15.5% (P=0.99). For the determination of the content of boron in plant materials about 50-100 mg of dry weight are necessary. (Author)

  17. Soil pH Errors Propagation from Measurements to Spatial Predictions - Cost Benefit Analysis and Risk Assessment Implications for Practitioners and Modelers

    Science.gov (United States)

    Owens, P. R.; Libohova, Z.; Seybold, C. A.; Wills, S. A.; Peaslee, S.; Beaudette, D.; Lindbo, D. L.

    2017-12-01

    The measurement errors and spatial prediction uncertainties of soil properties in the modeling community are usually assessed against measured values when available. However, of equal importance is the assessment of errors and uncertainty impacts on cost benefit analysis and risk assessments. Soil pH was selected as one of the most commonly measured soil properties used for liming recommendations. The objective of this study was to assess the error size from different sources and their implications with respect to management decisions. Error sources include measurement methods, laboratory sources, pedotransfer functions, database transections, spatial aggregations, etc. Several databases of measured and predicted soil pH were used for this study including the United States National Cooperative Soil Survey Characterization Database (NCSS-SCDB), the US Soil Survey Geographic (SSURGO) Database. The distribution of errors among different sources from measurement methods to spatial aggregation showed a wide range of values. The greatest RMSE of 0.79 pH units was from spatial aggregation (SSURGO vs Kriging), while the measurement methods had the lowest RMSE of 0.06 pH units. Assuming the order of data acquisition based on the transaction distance i.e. from measurement method to spatial aggregation the RMSE increased from 0.06 to 0.8 pH units suggesting an "error propagation". This has major implications for practitioners and modeling community. Most soil liming rate recommendations are based on 0.1 pH unit increments, while the desired soil pH level increments are based on 0.4 to 0.5 pH units. Thus, even when the measured and desired target soil pH are the same most guidelines recommend 1 ton ha-1 lime, which translates in 111 ha-1 that the farmer has to factor in the cost-benefit analysis. However, this analysis need to be based on uncertainty predictions (0.5-1.0 pH units) rather than measurement errors (0.1 pH units) which would translate in 555-1,111 investment that

  18. Drilling and the associated drillhole measurements of the pilot hole ONK-PH6

    International Nuclear Information System (INIS)

    Oehberg, A.; Hirvonen, H.; Kemppainen, K.; Niemonen, J.; Nordbaeck, N.; Poellaenen, J.; Rouhiainen, P.; Rautio, T.; Tarvainen, A.-M.

    2007-08-01

    The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are drillholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes are aimed to confirm the quality of the rock mass for tunnel construction, and in particular to identify water conductive fractured zones and to provide information that could result in modifications of the existing construction plans. The pilot hole ONK-PH6 was drilled from chainage 1404 to chainage 1559 in September 2006. The length of the hole is 155.04 m. The aim during the drilling work was to orient core samples as much as possible. The deviation of the drillhole was measured during and after the drilling phase. One steering operation by wedging was made at the hole depth of 94.05 metres (top of the wedge). Electric conductivity was measured from the collected returning water samples. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The tests to determine rock strength and deformation properties were made with a Rock Tester-equipment. Difference Flow method was used for the determination of hydraulic conductivity in fractures and fractured zones in the drillhole. The overlapping i.e. the detailed flow logging mode was used. Besides flow logging Single Point Resistance (SPR), Electric Conductivity (EC) and temperature of the drillhole water were also measured. The flow logging was performed with 0.5 m section length and with 0.1 m depth increment. Water loss tests were conducted in the hole excluding the section 89.04 - 101.04 metres due to the wedge. Geophysical logging

  19. Biocompatible click chemistry enabled compartment-specific pH measurement inside E. coli.

    Science.gov (United States)

    Yang, Maiyun; Jalloh, Abubakar S; Wei, Wei; Zhao, Jing; Wu, Peng; Chen, Peng R

    2014-09-19

    Bioorthogonal reactions, especially the Cu(I)-catalysed azide-alkyne cycloaddition, have revolutionized our ability to label and manipulate biomolecules under living conditions. The cytotoxicity of Cu(I) ions, however, has hindered the application of this reaction in the internal space of living cells. By systematically surveying a panel of Cu(I)-stabilizing ligands in promoting protein labelling within the cytoplasm of Escherichia coli, we identify a highly efficient and biocompatible catalyst for intracellular modification of proteins by azide-alkyne cycloaddition. This reaction permits us to conjugate an environment-sensitive fluorophore site specifically onto HdeA, an acid-stress chaperone that adopts pH-dependent conformational changes, in both the periplasm and cytoplasm of E. coli. The resulting protein-fluorophore hybrid pH indicators enable compartment-specific pH measurement to determine the pH gradient across the E. coli cytoplasmic membrane. This construct also allows the measurement of E. coli transmembrane potential, and the determination of the proton motive force across its inner membrane under normal and acid-stress conditions.

  20. Residual stress measurements via neutron diffraction of additive manufactured stainless steel 17-4 PH.

    Science.gov (United States)

    Masoomi, Mohammad; Shamsaei, Nima; Winholtz, Robert A; Milner, Justin L; Gnäupel-Herold, Thomas; Elwany, Alaa; Mahmoudi, Mohamad; Thompson, Scott M

    2017-08-01

    Neutron diffraction was employed to measure internal residual stresses at various locations along stainless steel (SS) 17-4 PH specimens additively manufactured via laser-powder bed fusion (L-PBF). Of these specimens, two were rods (diameter=8 mm, length=80 mm) built vertically upward and one a parallelepiped (8×80×9 mm 3 ) built with its longest edge parallel to ground. One rod and the parallelepiped were left in their as-built condition, while the other rod was heat treated. Data presented provide insight into the microstructural characteristics of typical L-PBF SS 17-4 PH specimens and their dependence on build orientation and post-processing procedures such as heat treatment. Data have been deposited in the Data in Brief Dataverse repository (doi:10.7910/DVN/T41S3V).

  1. Residual stress measurements via neutron diffraction of additive manufactured stainless steel 17-4 PH

    Directory of Open Access Journals (Sweden)

    Mohammad Masoomi

    2017-08-01

    Full Text Available Neutron diffraction was employed to measure internal residual stresses at various locations along stainless steel (SS 17-4 PH specimens additively manufactured via laser-powder bed fusion (L-PBF. Of these specimens, two were rods (diameter=8 mm, length=80 mm built vertically upward and one a parallelepiped (8×80×9 mm3 built with its longest edge parallel to ground. One rod and the parallelepiped were left in their as-built condition, while the other rod was heat treated. Data presented provide insight into the microstructural characteristics of typical L-PBF SS 17-4 PH specimens and their dependence on build orientation and post-processing procedures such as heat treatment. Data have been deposited in the Data in Brief Dataverse repository (doi:10.7910/DVN/T41S3V.

  2. Drilling and associated drillhole measurements of the pilot hole ONK-PH13

    International Nuclear Information System (INIS)

    Tarvainen, A.-M.; Toropainen, V.; Pekkanen, J.; Poellaenen, J.; Kosunen, P.; Lahti, M.; Pere, T.; Aalto, P.

    2011-04-01

    . Groundwater samples were not collected due to too low inflow to the drillhole. Geophysical surveys included natural gamma radiation, gamma-gamma density, magnetic susceptibility, Wenner resistivity, short and long normal resistivity, single point resistance, drillhole radar and full waveform sonic measurements as well as optical and acoustic imaging. The results were joined with the available geological data received from Posiva. A group of geoscientists produced an integrated interpretation based on the investigation results of ONK-PH13. In single-hole interpretation the objective is to identify and describe the general characteristics of major rock units and possible deformation zones within a drillhole. A single-hole interpretation involves integrated interpretation of the data from the geological mapping, geophysical logging as well as hydrogeological investigations. The method is regarded useful for integrated and detailed modelling for the use of the RSC (Rock Suitability Criteria) program. (orig.)

  3. Cellular pH measurements in Emiliania huxleyi reveal pronounced membrane proton permeability.

    Science.gov (United States)

    Suffrian, K; Schulz, K G; Gutowska, M A; Riebesell, U; Bleich, M

    2011-05-01

    • To understand the influence of changing surface ocean pH and carbonate chemistry on the coccolithophore Emiliania huxleyi, it is necessary to characterize mechanisms involved in pH homeostasis and ion transport. • Here, we measured effects of changes in seawater carbonate chemistry on the fluorescence emission ratio of BCECF (2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein) as a measure of intracellular pH (pH(i)). Out of equilibrium solutions were used to differentiate between membrane permeation pathways for H(+), CO(2) and HCO(3)(-). • Changes in fluorescence ratio were calibrated in single cells, resulting in a ratio change of 0.78 per pH(i) unit. pH(i) acutely followed the pH of seawater (pH(e)) in a linear fashion between pH(e) values of 6.5 and 9 with a slope of 0.44 per pH(e) unit. pH(i) was nearly insensitive to changes in seawater CO(2) at constant pH(e) and HCO(3)(-). An increase in extracellular HCO(3)(-) resulted in a slight intracellular acidification. In the presence of DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid), a broad-spectrum inhibitor of anion exchangers, E. huxleyi acidified irreversibly. DIDS slightly reduced the effect of pH(e) on pH(i). • The data for the first time show the occurrence of a proton permeation pathway in E. huxleyi plasma membrane. pH(i) homeostasis involves a DIDS-sensitive mechanism. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  4. Fetal short time variation during labor: a non-invasive alternative to fetal scalp pH measurements?

    Science.gov (United States)

    Schiermeier, Sven; Reinhard, Joscha; Hatzmann, Hendrike; Zimmermann, Ralf C; Westhof, Gregor

    2009-01-01

    To determine whether short time variation (STV) of fetal heart beat correlates with scalp pH measurements during labor. From 1279 deliveries, 197 women had at least one fetal scalp pH measurement. Using the CTG-Player, STVs were calculated from the electronically saved cardiotocography (CTG) traces and related to the fetal scalp pH measurements. There was no correlation between STV and fetal scalp pH measurements (r=-0.0592). Fetal STV is an important parameter with high sensitivity for antenatal fetal acidosis. This study shows that STV calculations do not correlate with fetal scalp pH measurements during labor, hence are not helpful in identifying fetal acidosis.

  5. pH-Free Measurement of Relative Acidities, Including Isotope Effects.

    Science.gov (United States)

    Perrin, Charles L

    2017-01-01

    A powerful pH-free multicomponent NMR titration method can measure relative acidities, even of closely related compounds, with excellent accuracy. The history of the method is presented, along with details of its implementation and a comparison with earlier NMR titrations using a pH electrode. Many of its areas of applicability are described, especially equilibrium isotope effects. The advantages of the method, some practical considerations, and potential pitfalls are considered. © 2017 Elsevier Inc. All rights reserved.

  6. Drilling and the associated drillhole measurements of the pilot hole ONK-PH5

    International Nuclear Information System (INIS)

    Oehberg, A.; Hirvonen, H.; Jurvanen, T.; Kemppainen, K.; Mustonen, A.; Niemonen, J.; Poellaenen, J.; Rouhiainen, P.; Rautio, T.

    2006-09-01

    The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are drillholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes are aimed to confirm the quality of the rock mass for tunnel construction, and in particular to identify water conductive fractured zones and to provide information that could result in modifications of the existing construction plans. The pilot hole ONK-PH5 was drilled from chainage 991.4 to chainage 1194 in January 2006. The length of the hole is 202.64 m and the vertical depth of the hole from zero level is about 88.2-107.5 m. The aim during the drilling work was to orient core samples as much as possible. The deviation of the drillhole was measured during and after the drilling phase. One steering operation by wedging was made at the hole depth of 128.58 metres. Electric conductivity was measured from the collected returning water samples. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The tests to determine rock strength and deformation properties were made with a Rock Tester-equipment. Due to high inflow (c. 200 L/min) mainly from the depth section 56-58 metres no geophysical surveys were carried out in the hole. Flow logging was carried out only from 58 metres to the bottom of the hole. Difference Flow method was used for the determination of hydraulic conductivity in fractures and fractured zones in the drillhole. The overlapping i.e. the detailed flow logging mode was used. The flow logging was performed with 0.5 m section length and with 0.1 m depth increment. Flow

  7. Microenvironmental pH measurement during sodium naproxenate dissolution in acidic medium by UV/vis imaging

    DEFF Research Database (Denmark)

    Ostergaard, Jesper; Jensen, Henrik; Larsen, Susan W

    2014-01-01

    Variable dissolution from sodium salts of drugs containing a carboxylic acid group after passing the acidic environment of the stomach may affect oral bioavailability. The aim of the present proof of concept study was to investigate pH effects in relation to the dissolution of sodium naproxenate...... in 0.01M hydrochloric acid. For this purpose a UV/vis imaging-based approach capable of measuring microenvironmental pH in the vicinity of the solid drug compact as well as monitoring drug dissolution was developed. Using a pH indicating dye real-time spatially resolved measurement of pH was achieved....... Sodium naproxenate, can significantly alter the local pH of the dissolution medium, is eventually neutralized and precipitates as the acidic species naproxen. The developed approach is considered useful for detailed studies of pH dependent dissolution phenomena in dissolution testing....

  8. Assessment of the suitability of Durafet-based sensors for pH measurement in dynamic estuarine environments

    Science.gov (United States)

    Gonski, Stephen F.; Cai, Wei-Jun; Ullman, William J.; Joesoef, Andrew; Main, Christopher R.; Pettay, D. Tye; Martz, Todd R.

    2018-01-01

    The suitability of the Honeywell Durafet to the measurement of pH in productive, high-fouling, and highly-turbid estuarine environments was investigated at the confluence of the Murderkill Estuary and Delaware Bay (Delaware, USA). Three different flow configurations of the SeapHOx sensor equipped with a Honeywell Durafet and its integrated internal (Ag/AgCl reference electrode containing a 4.5 M KCl gel liquid junction) and external (solid-state chloride ion selective electrode, Cl-ISE) reference electrodes were deployed for four periods between April 2015 and September 2016. In this environment, the Honeywell Durafet proved capable of making high-resolution and high-frequency pH measurements on the total scale between pH 6.8 and 8.4. Natural pH fluctuations of >1 pH unit were routinely captured over a range of timescales. The sensor pH collected between May and August 2016 using the most refined SeapHOx configuration exhibited good agreement with multiple sets of independently measured reference pH values. When deployed in conjunction with rigorous discrete sampling and calibration schemes, the sensor pH had a root-mean squared error ranging between 0.011 and 0.036 pH units across a wide range of salinity relative to both pHT calculated from measured dissolved inorganic carbon and total alkalinity and pHNBS measured with a glass electrode corrected to pHT at in situ conditions. The present work demonstrates the viability of the Honeywell Durafet to the measurement of pH to within the weather-level precision defined by the Global Ocean Acidification Observing Network (GOA-ON, ≤ 0.02 pH units) as a part of future estuarine CO2 chemistry studies undertaken in dynamic environments.

  9. 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

  10. Conformational changes in human serum albumin around the neutral pH from circular dichroic measurements

    NARCIS (Netherlands)

    Wilting, J.; Weideman, M.M.; Roomer, A.C.J.; Perrin, J.H.

    1979-01-01

    The molar ellipticity of the warfarin-albumin complex at 310 nm increases with pH from 6 to 9. This pH dependence runs parallel with that of the molar ellipticity of the albumin alone at 292 nm. The change in molar ellipticity with pH occurs in a smaller pH interval after addition of the

  11. Standard test method for measuring pH of soil for use in corrosion testing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1995-01-01

    1.1 This test method covers a procedure for determining the pH of a soil in corrosion testing. The principle use of the test is to supplement soil resistivity measurements and thereby identify conditions under which the corrosion of metals in soil may be accentuated (see G 57 - 78 (1984)). 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  12. Polymeric nanosensors for measuring the full dynamic pH range of endosomes and lysosomes in mammalian cells

    DEFF Research Database (Denmark)

    Sun, Honghao; Andresen, Thomas Lars; Benjaminsen, Rikke Vicki

    2009-01-01

    Polymer nanoparticle sensors have been constructed for studying pH in the endocytic pathway in mammalian cells. The pH sensors for fluorescence ratiometric measurements were prepared using inverse microemulsion polymerization with rhodamine as reference fluorophor and fluorescein and oregon green...... was used to introduce a net positive charge in the cationic particles. It was found that the positively charged particle sensors were internalized spontaneously by HepG2 cancer cells. These new pH nanosensors are potential tools in time resolved quantification of pH in the endocytic pathway of living cells....

  13. Scintigraphy, pH measurement and radiography in the evaluation of gastroesophageal reflux

    International Nuclear Information System (INIS)

    Kaul, B.; Petersen, H.; Grette, K.; Erichsen, H.; Myrvold, H.E.

    1985-01-01

    Scintigraphy as a diagnostic tool has been explored in 69 patients with gastroesophageal reflux (GER) symptoms and endoscopic esophagitis. In all subjects the presence of reflux was also evaluated by radiography and intraesophageal pH measurements (standard acid reflux test). The overall sensitivity of scintigraphy (85.5%) was significantly higher than those of radiography (27.5%) and pH measurements (69.5%). Scintigraphy was performed with normal saline and with acidified orange juice as the transport medium for the isotope 99mTc. The yield of positive scintigrams was higher (22.3 to 61.1%, depending on the grade of endoscopic esophagitis) with the latter variant. Moreover, demonstration of spontaneous reflux was greatly facilitated by the acid scintigraphy. This was particularly obvious in the grade I esophagitis, in which the freqency of spontaneous reflux with saline method was 3.4% and with acid medium 34/3%. Reflux (induced or spontaneous) was seen in 22 normal control subjects with the saline method, and in 1 subject only with the acid method. On the basis of these findings it is concluded that scintigraphy, especially the acid variant of the technique, is a valuable diagnostic procedure in GER disease

  14. Scintigraphy, pH measurement and radiography in the evaluation of gastroesophageal reflux

    Energy Technology Data Exchange (ETDEWEB)

    Kaul, B.; Petersen, H.; Grette, K.; Erichsen, H.; Myrvold, H.E.

    1985-01-01

    Scintigraphy as a diagnostic tool has been explored in 69 patients with gastroesophageal reflux (GER) symptoms and endoscopic esophagitis. In all subjects the presence of reflux was also evaluated by radiography and intraesophageal pH measurements (standard acid reflux test). The overall sensitivity of scintigraphy (85.5%) was significantly higher than those of radiography (27.5%) and pH measurements (69.5%). Scintigraphy was performed with normal saline and with acidified orange juice as the transport medium for the isotope 99mTc. The yield of positive scintigrams was higher (22.3 to 61.1%, depending on the grade of endoscopic esophagitis) with the latter variant. Moreover, demonstration of spontaneous reflux was greatly facilitated by the acid scintigraphy. This was particularly obvious in the grade I esophagitis, in which the freqency of spontaneous reflux with saline method was 3.4% and with acid medium 34/3%. Reflux (induced or spontaneous) was seen in 22 normal control subjects with the saline method, and in 1 subject only with the acid method. On the basis of these findings it is concluded that scintigraphy, especially the acid variant of the technique, is a valuable diagnostic procedure in GER disease.

  15. Peptide-targeted delivery of a pH sensor for quantitative measurements of intraglycosomal pH in live Trypanosoma brucei.

    Science.gov (United States)

    Lin, Sheng; Morris, Meredith T; Ackroyd, P Christine; Morris, James C; Christensen, Kenneth A

    2013-05-28

    Studies of dynamic changes in organelles of protozoan parasite Trypanosoma brucei have been limited, in part because of the difficulty of targeting analytical probes to specific subcellular compartments. Here we demonstrate application of a ratiometric probe for pH quantification in T. brucei glycosomes. The probe consists of a peptide encoding the peroxisomal targeting sequence (F-PTS1, acetyl-CKGGAKL) coupled to fluorescein, which responds to pH. When incubated with living parasites, the probe is internalized within vesicular structures that colocalize with a glycosomal marker. Inhibition of uptake of F-PTS1 at 4 °C and pulse-chase colocalization with fluorescent dextran suggested that the probe is initially taken up by non-receptor-mediated endocytosis but is subsequently transported separately from dextran and localized within glycosomes, prior to the final fusion of labeled glycosomes and lysosomes as part of glycosomal turnover. Intraorganellar measurements and pH calibration with F-PTS1 in T. brucei glycosomes indicate that the resting glycosomal pH under physiological conditions is 7.4 ± 0.2. However, incubation in glucose-depleted buffer triggered mild acidification of the glycosome over a period of 20 min, with a final observed pH of 6.8 ± 0.3. This glycosomal acidification was reversed by reintroduction of glucose. Coupling of ratiometric fluorescent sensors and reporters to PTS peptides offers an invaluable tool for monitoring in situ glycosomal response(s) to changing environmental conditions and could be applied to additional kinetoplastid parasites.

  16. Continuous measurement of intra-oral pH and temperature: development, validation of an appliance and a pilot study.

    Science.gov (United States)

    Choi, J E; Loke, C; Waddell, J N; Lyons, K M; Kieser, J A; Farella, M

    2015-08-01

    To describe a novel approach for continuous measurement of intra-oral pH and temperature in individuals carrying out normal daily activities over 24 h. We designed, validated and constructed a custom-made appliance fitted with a pH probe and a thermocouple. Six subjects wore the appliance over a 24-h period for two non-consecutive days, while the intra-oral pH and temperature were measured continuously and recorded. Intra-oral pH and temperature were very similar across different recording days, the difference being not statistically significant (P ≥ 0.14). There was a noticeable difference in the pattern of variation of pH between day and night. During the day, the mean pH was 7.3 (±0.4) and dropped markedly only after consumption of acidic food and drinks. The intra-oral pH decreased slowly during sleep with an average pH of 6.6 (±0.4) being recorded. The difference between day and night was statistically significant (P = 0.002). The mean intra-oral temperature was 33.9 °C (±0.9) during daytime and 35·9 °C (±0·5) during sleep (P = 0.013) with minor fluctuations occurring over 24 h. The continuous and simultaneous intra-oral pH and temperature measurement system described in this report is reliable, easy to construct, able to measure variables over a sustained period and may serve as a future diagnostic tool in a number of applications. © 2015 John Wiley & Sons Ltd.

  17. Label-free silicon nanodots featured ratiometric fluorescent aptasensor for lysosomal imaging and pH measurement.

    Science.gov (United States)

    Zhang, Yanan; Guo, Shan; Cheng, Shibo; Ji, Xinghu; He, Zhike

    2017-08-15

    The homeostasis of lysosomal pH is crucial in cell physiology. Developing small fluorescent nanosensors for lysosome imaging and ratiometric measurement of pH is highly demanded yet challenging. Herein, a pH-sensitive fluorescein tagged aptamer AS1411 has been utilized to covalently modify the label-free fluorescent silicon nanodots via a crosslinker for construction of a ratiometric pH biosensor. The established aptasensor exhibits the advantages of ultrasmall size, hypotoxicity, excellent pH reversibility and good photostability, which favors its application in an intracellular environment. Using human breast MCF-7 cancer cells and MCF-10A normal cells as the model, this aptasensor shows cell specificity for cancer cells and displays a wide pH response range of 4.5-8.0 in living cells. The results demonstrate that the pH of MCF-7 cells is 5.1, which is the expected value for acidic organelles. Lysosome imaging and accurate measurement of pH in MCF-7 cells have been successfully conducted based on this nanosensor via fluorescent microscopy and flow cytometry. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Measurement of pH, alkalinity and acidity in ultra-soft waters

    African Journals Online (AJOL)

    drinie

    2001-10-04

    Oct 4, 2001 ... A blend composed of the raw water, sodium chloride (to increase conductivity), and standard bicarbonate (to increase buffering capacity) was titrated with standard strong acid in two pH regions: 6.3 pH < 4.0. In both methods, total alkalinity was determined using the latter set of points, ...

  19. Validation of the measurement of pH in water of the secondary circuit in the range 9 to 10 at 25 deg. C

    International Nuclear Information System (INIS)

    Gorgoschidse, Marina; Zilli, Mariano; Echeverria, Paola; Schonbord, Betina

    2012-09-01

    pH measurement is a control parameter used for water conditioning in the secondary circuit at Atucha Nuclear Plant. As such it is an important indicator of the protection of structural components against corrosion. Its magnitude and importance determines the dosing and selection appropriate chemical agents for using in the CNAI's, therefore the need, for a measurement methodology validation. A pH measurement made in the wrong way can lead the deterioration due the alkaline environment in which we are working. In this paper we review the methods to study various experimental parameters involved in the measurements: characteristics of the state of the electrochemical cell, including measurement time, liquid junction and agitation error. Lastly, results are described in terms of precision parameters (repeatability and reproducibility) and accuracy (authors)

  20. Time-to-Fatigue and Intramuscular pH Measured via NIRS During Handgrip Exercise in Trained and Sedentary Individuals

    Science.gov (United States)

    Everett, M. E.; Lee, S. M. C.; Stroud, L.; Scott, P.; Hagan, R. D.; Soller, B. R.

    2009-01-01

    In exercising muscles force production and muscular endurance are impaired by a decrease in intramuscular pH. The effects of aerobic training (AT) on preventing acidosis and prolonging exercise time in muscles not specifically targeted by the training are unknown. Purpose: To compare interstitial pH, measured non-invasively with near infrared spectroscopy (NIRS), in the flexor digitorum profundus (FDP) during rhythmic handgrip exercise in sedentary subjects and those who participate in AT activities that target the lower body. Methods: Maximal isometric force (MIF) was measured on three separate days in AT (n=5) and sedentary (n=8) subjects using a handgrip dynamometer (HGD). Isometric muscular endurance (IME) was measured during five trials, each separated by at least 48 hrs. For each IME trial subjects rhythmically squeezed (4 sec at 40% of MVC) and relaxed (2 sec) to fatigue or failure to reach the target force in three consecutive contractions or four non-consecutive contractions. Interstitial pH was derived from spectra collected using a NIRS sensor adhered to the skin over the FDP. The first four IME trials served to familiarize subjects with the protocol; the fifth trial was used for analysis. NIRS-derived pH was averaged in 30 sec increments. Between group differences in MIF and exercise time were tested using paired t-tests. A repeated measures ANOVA was used to analyze effects of AT and exercise time on pH. Results: MIF was not different between groups (mean SD; aerobic=415.6 95.4 N vs. sedentary =505.1 107.4 N). Time to fatigue was greater in the AT than in the sedentary group (mean SD: 611 173 sec vs. 377 162 sec, p<0.05). pH was not different between groups at any time point. Average pH decreased (p<0.05) in both groups from rest (pH=7.4) through 90 sec of exercise (pH=6.9), but did not decrease further throughout the remainder of exercise. Conclusion: Although between group differences in pH were not detected, differences during the onset of exercise

  1. Self-Assembled Fluorescent Bovine Serum Albumin Nanoprobes for Ratiometric pH Measurement inside Living Cells.

    Science.gov (United States)

    Yang, Qiaoyu; Ye, Zhongju; Zhong, Meile; Chen, Bo; Chen, Jian; Zeng, Rongjin; Wei, Lin; Li, Hung-wing; Xiao, Lehui

    2016-04-20

    In this work, we demonstrated a new ratiometric method for the quantitative analysis of pH inside living cells. The structure of the nanosensor comprises a biofriendly fluorescent bovine serum albumin (BSA) matrix, acting as a pH probe, and pH-insensitive reference dye Alexa 594 enabling ratiometric quantitative pH measurement. The fluorescent BSA matrix was synthesized by cross-linking of the denatured BSA proteins in ethanol with glutaraldehyde. The size of the as-synthesized BSA nanoparticles can be readily manipulated from 30 to 90 nm, which exhibit decent fluorescence at the peak wavelength of 535 nm with a pH response range of 6-8. The potential of this pH sensor for intracellular pH monitoring was demonstrated inside living HeLa cells, whereby a significant change in fluorescence ratio was observed when the pH of the cell was switched from normal to acidic with anticancer drug treatment. The fast response of the nanosensor makes it a very powerful tool in monitoring the processes occurring within the cytosol.

  2. Force measuring valve assemblies, systems including such valve assemblies and related methods

    Science.gov (United States)

    DeWall, Kevin George [Pocatello, ID; Garcia, Humberto Enrique [Idaho Falls, ID; McKellar, Michael George [Idaho Falls, ID

    2012-04-17

    Methods of evaluating a fluid condition may include stroking a valve member and measuring a force acting on the valve member during the stroke. Methods of evaluating a fluid condition may include measuring a force acting on a valve member in the presence of fluid flow over a period of time and evaluating at least one of the frequency of changes in the measured force over the period of time and the magnitude of the changes in the measured force over the period of time to identify the presence of an anomaly in a fluid flow and, optionally, its estimated location. Methods of evaluating a valve condition may include directing a fluid flow through a valve while stroking a valve member, measuring a force acting on the valve member during the stroke, and comparing the measured force to a reference force. Valve assemblies and related systems are also disclosed.

  3. Synthesis and Characterization of a Micelle-Based pH Nanosensor with an Unprecedented Broad Measurement Range

    DEFF Research Database (Denmark)

    Ek, Pramod Kumar; Feldborg, Lise N.; Almdal, Kristoffer

    2013-01-01

    A new cross-linked micelle pH nanosensor design was investigated. The nanosensor synthesis was based on self-assembly of an amphiphilic triblock copolymer, poly(ethylene glycol)-b-poly(2-amino ethyl methacrylate)-b-poly(coumarin methacrylate) (PEG-b-PAEMA-b-PCMA), which was synthesized by isolated...... irradiation (320 nm pH nanosensors by binding the pH-sensitive fluorophores oregon green 488 and 2′,7′-bis-(2-carboxyethyl)-5-(and-6......) carboxyfluorescein and a reference fluorophore Alexa 633 to the PAEMA shell region of the micelles. Fluorescence measurements show that these pH nanosensors are sensitive in a surprisingly broad pH range of 3.4–8.0, which is hypothesized to be due to small differences in the individual fluorophores’ local...

  4. Single molecule force measurements delineate salt, pH and surface effects on biopolymer adhesion

    International Nuclear Information System (INIS)

    Pirzer, T; Geisler, M; Hugel, T; Scheibel, T

    2009-01-01

    In this paper we probe the influence of surface properties, pH and salt on the adhesion of recombinant spider silk proteins onto solid substrates with single molecule force spectroscopy. A single engineered spider silk protein (monomeric C 16 or dimeric (QAQ) 8 NR3) is covalently bound with one end to an AFM tip, which assures long-time measurements for hours with one and the same protein. The tip with the protein is brought into contact with various substrates at various buffer conditions and then retracted to desorb the protein. We observe a linear dependence of the adhesion force on the concentration of three selected salts (NaCl, NaH 2 PO 4 and NaI) and a Hofmeister series both for anions and cations. As expected, the more hydrophobic C 16 shows a higher adhesion force than (QAQ) 8 NR3, and the adhesion force rises with the hydrophobicity of the substrate. Unexpected is the magnitude of the dependences—we never observe a change of more than 30%, suggesting a surprisingly well-regulated balance between dispersive forces, water-structure-induced forces as well as co-solute-induced forces in biopolymer adhesion

  5. Single molecule force measurements delineate salt, pH and surface effects on biopolymer adhesion

    Science.gov (United States)

    Pirzer, T.; Geisler, M.; Scheibel, T.; Hugel, T.

    2009-06-01

    In this paper we probe the influence of surface properties, pH and salt on the adhesion of recombinant spider silk proteins onto solid substrates with single molecule force spectroscopy. A single engineered spider silk protein (monomeric C16 or dimeric (QAQ)8NR3) is covalently bound with one end to an AFM tip, which assures long-time measurements for hours with one and the same protein. The tip with the protein is brought into contact with various substrates at various buffer conditions and then retracted to desorb the protein. We observe a linear dependence of the adhesion force on the concentration of three selected salts (NaCl, NaH2PO4 and NaI) and a Hofmeister series both for anions and cations. As expected, the more hydrophobic C16 shows a higher adhesion force than (QAQ)8NR3, and the adhesion force rises with the hydrophobicity of the substrate. Unexpected is the magnitude of the dependences—we never observe a change of more than 30%, suggesting a surprisingly well-regulated balance between dispersive forces, water-structure-induced forces as well as co-solute-induced forces in biopolymer adhesion.

  6. Preparation of acridine orange-doped silica nanoparticles for pH measurement

    International Nuclear Information System (INIS)

    Liu, Jinshui; Zang, Lingjie; Wang, Yiru; Liu, Guoning

    2014-01-01

    Acridine orange was first encapsulated into silica shell via a facile reverse microemusion method to built core–shell fluorescent nanoparticles. The nanoparticles are all in spherical shape and have a narrow size distribution, and its application as a optical pH sensor has been demonstrated. This novel sensor is based on the pH-dependent fluorescence intensities of acridine orange in different pH value. The fluorescence intensity of acridine orange-doped silica nanoparticles was decreased by increasing pH value. Under optimum conditions, the changes of fluorescence intensity were proportional to the pH value in the range of 8.00–10.90. In addition, the sensor can be easily separated by centrifugation and adds no pollution to the environment compared to the free dyes. Furthermore, the effects of ionic strength and co-existing substances were proved to have little influence on the determination of pH. The sensor has been successfully applied to determine the pH of two artificial samples. Hence, the core–shell fluorescent nanoparticles show potential for practical application. -- Highlights: • Acridine orange was encapsulated into silica shell via a facile reverse microemusion method to built core–shell fluorescent nanoparticles. • The fluorescence intensity of acridine orange-doped silica nanoparticles was decreased by increasing pH value. • Its can be used as an optical pH sensor. • The sensor can be easily separated by centrifugation and adds no pollution to the environment compared to the free dyes. • The sensor has been successfully applied to determine the pH of artificial samples

  7. Development of novel Sol-Gel Indicators (SGI's) for in-situ environmental measurements: Part 1, Program and a new pH Sol-Gel Indicator

    International Nuclear Information System (INIS)

    Livingston, R.R.; Baylor, L.; Wicks, G.G.

    1992-01-01

    The feasibility of incorporating analytical indicators into a sol-gel glassy matrix and then coating substrates with this composite material has bee demonstrated. Substrates coated include paper, wood, glass, and the lens of an analytical probe. The first SRTC sol-gel indicator, comprising bromophenol blue dispersed in a silica matrix, was fabricated and successfully used to measure solution pH in the range of pH 3.0 to 7.5. material exhibited a quick response time, as measured by color changes both qualitatively and quantitatively, and the measuring device was reversible or reusable. Additional indicators with responses over other ranges as well as indicators sensitive to the presence of elements of interest, are also under development. The new SGI composites possess promising properties and an excellent potential for performing a variety important in-situ environmental measurements and area discussed in this report

  8. Measurement of the internal pH of mast cell granules using microvolumetric fluorescence and isotopic techniques

    International Nuclear Information System (INIS)

    De Young, M.B.; Nemeth, E.F.; Scarpa, A.

    1987-01-01

    The intragranular pH of isolated mast cell granules was measured. Because of the minute amounts of isolated granules available, two techniques were developed by modifying aminoacridine fluorescence and [ 14 C]methylamine accumulation techniques to permit measurements with microliter sample volumes. Granule purity was demonstrated by electron microscopy, ruthenium red exclusion, and biochemical (histamine, mast cell granule protease) analysis. The internal pH was determined to be 5.55 +/- 0.06, indicating that the pH environment within mast cell granules is not significantly different from that of previously studied granule types (i.e., chromaffin, platelet, pancreatic islet, and pituitary granules). Collapse of the pH gradient by NH+4 was demonstrated with both techniques. No evidence of Cl-/OH- or specific cation/H+ transport was found, and major chloride permeability could not be unequivocably demonstrated. Ca 2+ and Cl- at concentrations normally present extracellularly destabilized granules in the presence of NH+4, but this phenomenon does not necessarily indicate a role for these ions in the exocytotic release of granule contents from intact cells. The pH measurement techniques developed for investigating the properties of granules in mast cells may be useful for studying other granules that can be obtained only in limited quantities

  9. A genetically encoded ratiometric sensor to measure extracellular pH in microdomains bounded by basolateral membranes of epithelial cells.

    Science.gov (United States)

    Urra, Javier; Sandoval, Moisés; Cornejo, Isabel; Barros, L Felipe; Sepúlveda, Francisco V; Cid, L Pablo

    2008-10-01

    Extracellular pH, especially in relatively inaccessible microdomains between cells, affects transport membrane protein activity and might have an intercellular signaling role. We have developed a genetically encoded extracellular pH sensor capable of detecting pH changes in basolateral spaces of epithelial cells. It consists of a chimerical membrane protein displaying concatenated enhanced variants of cyan fluorescence protein (ECFP) and yellow fluorescence protein (EYFP) at the external aspect of the cell surface. The construct, termed pHCECSensor01, was targeted to basolateral membranes of Madin-Darby canine kidney (MDCK) cells by means of a sequence derived from the aquaporin AQP4. The fusion of pH-sensitive EYFP with pH-insensitive ECFP allows ratiometric pH measurements. The titration curve of pHCECSensor01 in vivo had a pK (a) value of 6.5 +/- 0.04. Only minor effects of extracellular chloride on pHCECSensor01 were observed around the physiological concentrations of this anion. In MDCK cells, the sensor was able to detect changes in pH secondary to H(+) efflux into the basolateral spaces elicited by an ammonium prepulse or lactate load. This genetically encoded sensor has the potential to serve as a noninvasive tool for monitoring changes in extracellular pH microdomains in epithelial and other tissues in vivo.

  10. Electrochemiluminescent pH sensor measured by the emission potential of TiO2 nanocrystals and its biosensing application.

    Science.gov (United States)

    Liu, Xuan; Wang, Nianyue; Zhao, Wei; Jiang, Hui

    2015-02-01

    This work reports for the first time a potential-based nano-electrochemiluminescent (ECL) pH sensor, using anatase TiO2 nanocrystals (NCs) as the ECL probe. The first ECL peak potential of the TiO2 NCs shifted negatively with increasing pH, showing a linear range from -0.47 V (vs Ag/AgCl) at pH 3 to -1.06 V at pH 10. This phenomenon was attributed to the absorption of 'potential-determining ions' of OH(-) on the surface of TiO2 NCs, leading to larger impedance of the electron injection. Other common 'potential-determining ions', such as phosphate, induced a slight potential shift of 0.03 V at a concentration of 0.1 M. Using urease as an enzyme model, a urea biosensor was developed by the simultaneous modification of urease and TiO2 NCs on indium-tin oxide (ITO) electrodes. The biosensor, measured on the basis of the pH increase caused by the enzyme catalysis reaction, had a linear range of 0.01-2.0 mM, with a potential shift of 0.175 V. The as-prepared pH sensor, which has simple construction procedures and acceptable sensitivity and selectivity, may provide new avenues for the construction of ECL bioanalytical methodologies. Copyright © 2014 John Wiley & Sons, Ltd.

  11. Use of stream water pH and specific conductance measurements to identify ground water discharges of fly ash leachate

    International Nuclear Information System (INIS)

    Price, R.M.

    1992-01-01

    Low pH and high specific conductance are typical chemical characteristics of coal fly ash leachate. Measurements of these parameters in streams adjacent to a fly ash facility were used to identify areas of ground water discharge into the streams. In-situ specific conductance and pH were determined at approximately 50 surface water stations from on-site and off-site streams. The results of the in-situ determinations were used to select twelve surface water stations for more detailed chemical analyses. The chemical character of the stream water affected by ground water discharges was similar to the water quality of sedimentation ponds which received drainage from the fly ash embankment. The results indicated that in-situ measurements of indicator parameters such as pH and specific conductance can be used as a screening method for identifying surface water quality impacts at fly ash facilities

  12. Measuring Outcomes in Adult Weight Loss Studies That Include Diet and Physical Activity: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Rachel A. Millstein

    2014-01-01

    Full Text Available Background. Measuring success of obesity interventions is critical. Several methods measure weight loss outcomes but there is no consensus on best practices. This systematic review evaluates relevant outcomes (weight loss, BMI, % body fat, and fat mass to determine which might be the best indicator(s of success. Methods. Eligible articles described adult weight loss interventions that included diet and physical activity and a measure of weight or BMI change and body composition change. Results. 28 full-text articles met inclusion criteria. Subjects, settings, intervention lengths, and intensities varied. All studies measured body weight (−2.9 to −17.3 kg, 9 studies measured BMI (−1.1 to −5.1 kg/m2, 20 studies measured % body fat (−0.7 to −10.2%, and 22 studies measured fat mass (−0.9 to −14.9 kg. All studies found agreement between weight or BMI and body fat mass or body fat % decreases, though there were discrepancies in degree of significance between measures. Conclusions. Nearly all weight or BMI and body composition measures agreed. Since body fat is the most metabolically harmful tissue type, it may be a more meaningful measure of health change. Future studies should consider primarily measuring % body fat, rather than or in addition to weight or BMI.

  13. Comparative study of two modes of gastroesophageal reflux measuring: conventional esophageal pH monitoring and wireless pH monitoring

    Directory of Open Access Journals (Sweden)

    Rimon Sobhi Azzam

    2012-06-01

    Full Text Available CONTEXT: Esophageal pH monitoring is considered to be the gold standard for the diagnosis of gastroesophageal acid reflux. However, this method is very troublesome and considerably limits the patient's routine activities. Wireless pH monitoring was developed to avoid these restrictions. OBJECTIVE: To compare the first 24 hours of the conventional and wireless pH monitoring, positioned 3 cm above the lower esophageal sphincter, in relation to: the occurrence of relevant technical failures, the ability to detect reflux and the ability to correlate the clinical symptoms to reflux. METHODS: Twenty-five patients referred for esophageal pH monitoring and with typical symptoms of gastroesophageal reflux disease were studied prospectively, underwent clinical interview, endoscopy, esophageal manometry and were submitted, with a simultaneous initial period, to 24-hour catheter pH monitoring and 48-hour wireless pH monitoring. RESULTS: Early capsule detachment occurred in one (4% case and there were no technical failures with the catheter pH monitoring (P = 0.463. Percentages of reflux time (total, upright and supine were higher with the wireless pH monitoring (P < 0.05. Pathological gastroesophageal reflux occurred in 16 (64% patients submitted to catheter and in 19 (76% to the capsule (P = 0.355. The symptom index was positive in 12 (48% patients with catheter pH monitoring and in 13 (52% with wireless pH monitoring (P = 0.777. CONCLUSIONS: 1 No significant differences were reported between the two methods of pH monitoring (capsule vs catheter, in regard to relevant technical failures; 2 Wireless pH monitoring detected higher percentages of reflux time than the conventional pH-metry; 3 The two methods of pH monitoring were comparable in diagnosis of pathological gastroesophageal reflux and comparable in correlating the clinical symptoms with the gastroesophageal reflux.

  14. Characterization of PEBBLEs as a Tool for Real-Time Measurement of Dictyostelium discoideum Endosomal pH

    Directory of Open Access Journals (Sweden)

    Everett Moding

    2009-01-01

    Full Text Available The measurement of intracellular ion concentration change is important for understanding the cellular mechanisms for communication. Recently developed nanosensors, (Photonic Explorers for Biomedical use with Biologically Localized Embedding PEBBLEs, have a number of advantages for measuring ions in cells over established methods using microelectrodes, unbound fluorescent dyes, or NMR. PEBBLE sensors have been shown to work in principle for measuring dynamic ion changes, but few in vivo applications have been demonstrated. We modified the protocol for the fabrication of pH sensing PEBBLEs and developed a protocol for the utilization of these sensors for the monitoring of dynamic pH changes in the endosomes of slime mold Dictyostelium discoideum (D. discoideum. Oregon Green 514-CdSe Quantum Dot PEBBLEs were used to measure real-time pH inside D. discoideum endosomes during cAMP stimulation. Endosomal pH was shown to decrease during cAMP signaling, demonstrating a movement of protons into the endosomes of D. discoideum amoebae.

  15. Use of Pourbaix diagrams and the eH and pH measurements in hydrometallurgy. Part 2-Applications

    International Nuclear Information System (INIS)

    Teixeira, L.A.C.

    1987-01-01

    The interpretation of Pourbaix diagrams, presenting as examples; acid lixiviation of uranium ore, iron ion removal from process solutions, lixiviation of copper ores and cyaniding of Au ores containing Cu and Fe is presented. Practical aspects on eH and pH measurement in solutions of hydrometallurgical process. (M.C.K.) [pt

  16. Portable instrumentation for quantitatively measuring radioactive surface contaminations, including 90Sr

    International Nuclear Information System (INIS)

    Brodzinski, R.L.

    1983-10-01

    In order to measure the effectiveness of decontamination efforts, a quantitative analysis of the radiocontamination is necessary, both before and after decontamination. Since it is desirable to release the decontaminated material for unrestricted use or disposal, the assay equipment must provide adequate sensitivity to measure the radioactivity at or below the release limit. In addition, the instrumentation must be capable of measuring all kinds of radiocontaminants including fission products, activation products, and transuranic materials. Finally, the survey instrumentation must be extremely versatile in order to assay the wide variety of contaminated surfaces in many environments, some of which may be extremely hostile or remote. This communication describes the development and application of portable instrumentation capable of quantitatively measuring most transuranics, activation products, and fission products, including 90 Sr, on almost any contaminated surface in nearly any location

  17. Initial steps in defining the environment of the prepuce of the bull by measuring pH and temperature.

    Science.gov (United States)

    Koziol, J H; Fraser, N S; Passler, T; Wolfe, D F

    2017-12-01

    To determine the baseline pH and temperature of the preputial cavity of bulls. We enrolled 55 bulls ranging in age from 15 to 84 months. The preputial temperature and pH were measured by insertion of temperature and pH probes, respectively, into the preputial orifice prior to routine breeding soundness examinations. Information was obtained from owners regarding the diet of each bull and categorised as one of three categories: forage only, grain supplemented or silage supplemented. The average temperature of the prepuce was 37.81°C ± 1.76 and the median pH of the prepuce was 8.45 (6.35-9.46). Preputial temperatures of the bull weakly correlated with ambient temperatures (r s  = -0.29, P = 0.028). The preputial pH of silage-fed bulls was significantly lower than that of bulls fed forage only (P = 0.025) or grain-supplemented diets (P = 0.002). The median preputial pH of bulls fed a silage-based diet was 7.6 (6.3-8.9) compared with a median pH 8.7 (7.8-9.1) for bulls fed forage-based diets or a median of 8.5 (7.7-9.4) for those given grain-supplemented diets. Diet and ambient temperature can, respectively, affect pH and the temperature in the prepuce. Further studies to describe and understand the microbiota of the prepuce and penis may assist in developing treatments for diseases of the genital tract in bulls. © 2017 Australian Veterinary Association.

  18. Assessment of uncertainties in measurement of pH in hostile environments characteristic of nuclear repositories

    International Nuclear Information System (INIS)

    Kreider, K.G.; Tarlov, M.J.; Huang, P.H.

    1991-10-01

    This report focuses on evaluation and characteristics of sputtered thin film pH electrodes which can be used to assess the corrosivity of hot (100 degree C) aqueous solutions present in nuclear repositories. Sputtered thin films have the advantages of high temperature capability, ruggedness, and low cost. The iridium oxide films were found to have a linear, 58 mV/pH, response to changes in pH. They had little hysteresis but drifted approximately 0.2 V over a period of two days exposure to pH 2--12 solutions. The films were found to be insensitive to interference from most ions such as alkali ions but had redox sensitivity to ferri-/ferrocyanide ions. Although special surface treatments were needed for the films for good adherence at 200 degree C the films were not degraded after 20 hours exposure at pH 4, 7, and 10 at 200 degree C. Ruthenium oxide sputtered films performed equally well to the iridium oxide films in parallel tests. The report also contains information on electrochemistry and testing of thin film electrodes and the characterization of the thin films by x-ray photoemission spectroscopy, ultraviolet photoemission spectroscopy, and ion scattering spectroscopy. 123 refs., 29 figs., 7 tabs

  19. Measuring efficiency of university-industry Ph.D. projects using best worst method

    NARCIS (Netherlands)

    Salimi, N.; Rezaei, J.

    2016-01-01

    A collaborative Ph.D. project, carried out by a doctoral candidate, is a type of collaboration between university and industry. Due to the importance of such projects, researchers have considered different ways to evaluate the success, with a focus on the outputs of these projects. However, what

  20. Measurement of pH, alkalinity and acidity in ultra-soft waters | Lahav ...

    African Journals Online (AJOL)

    In the "blend" method, equilibrium chemistry data were used to calculate total acidity for each point based on the known total alkalinity, pH reading, temperature and ionic strength. The two methods gave excellent results (in terms of both repetition and accuracy) as compared to characterisation based on total alkalinity and ...

  1. 31P MR spectroscopic measurement of intracellular pH in normal human hearts

    International Nuclear Information System (INIS)

    Kwon, Jae Hyun; Lee, Hui Joong; Jang, Yong Min

    2002-01-01

    To assess the usefulness of intracellular pH (pHi), calculated by determining the shift of a high-energy metabolite such as inorganic phosphate (Pi) of γ-ATP after performing MRS with ECG-gated two-dimensional 31 P CSI (chemical shift imaging), as a parameter for the overall state of the intracellular milieu. Proto decoupled 31 P CSI was performed on a 1.5-T scanner using a 1 H 31 P dual-tuned surface coil. Cardiac MRS data were obtained from eight normal volunteers aged 24-32 years with no history of heart disease. From the spectra obtained from several regions of the heart, peack position and peak area were estimated. The metabolic ratios of α-, β-, γ-ATP, PCr, Pi, phosphodiester and diphosphoglycerate were calculated, and pHi was estimated from the chemical shift of Pi and γ-ATP resonance. We then compared the data for the anterior myocardium with those previously published. The major phosphorous metabolites identified in these human hearts were as follows: PCr, at -0.1 to +0.1 ppm; three phosphate peaks from ATP, with a chemical shift centered at about -2.7 ppm (γ-ATP), -7.8 ppm (α-ATP), and -16.3 ppm (β-ATP); and phosphodiester (PDE) at 2-3 ppm, inorganic phosphate (Pi) at 4.5-5.4 ppm, and diphosphoglycerate (DPG) at 5.4-6.3 ppm. The PCr/β-ATP ratio was 2.20±0.17 and the PDE/β-ATP ratio, 1.04±0.09 pHi readings were 7.31±0.23 (calculated by the shift of Pi) and 6.81±0.20 (calculated by the shift of γ-ATP). Pi/PCR was 0.539, a ratio higher than that mentioned in previously published reports. The measurement of intracellular metabolism was affected by various kinds of factors. We believe, however, that pHi readings indicate the overall state of the cardiac intracellular milieu. An unexpected pHi readings, seen at MRS, may reflect errors in the MR procedure itself and, or in the analytical method

  2. {sup 31}P MR spectroscopic measurement of intracellular pH in normal human hearts

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Jae Hyun; Lee, Hui Joong; Jang, Yong Min [Kyungpook National Univ., Taegu (Korea, Republic of)] [and others

    2002-05-01

    To assess the usefulness of intracellular pH (pHi), calculated by determining the shift of a high-energy metabolite such as inorganic phosphate (Pi) of {gamma}-ATP after performing MRS with ECG-gated two-dimensional {sup 31}P CSI (chemical shift imaging), as a parameter for the overall state of the intracellular milieu. Proto decoupled {sup 31}P CSI was performed on a 1.5-T scanner using a {sup 1}H{sup 31}P dual-tuned surface coil. Cardiac MRS data were obtained from eight normal volunteers aged 24-32 years with no history of heart disease. From the spectra obtained from several regions of the heart, peack position and peak area were estimated. The metabolic ratios of {alpha}-, {beta}-, {gamma}-ATP, PCr, Pi, phosphodiester and diphosphoglycerate were calculated, and pHi was estimated from the chemical shift of Pi and {gamma}-ATP resonance. We then compared the data for the anterior myocardium with those previously published. The major phosphorous metabolites identified in these human hearts were as follows: PCr, at -0.1 to +0.1 ppm; three phosphate peaks from ATP, with a chemical shift centered at about -2.7 ppm ({gamma}-ATP), -7.8 ppm ({alpha}-ATP), and -16.3 ppm ({beta}-ATP); and phosphodiester (PDE) at 2-3 ppm, inorganic phosphate (Pi) at 4.5-5.4 ppm, and diphosphoglycerate (DPG) at 5.4-6.3 ppm. The PCr/{beta}-ATP ratio was 2.20{+-}0.17 and the PDE/{beta}-ATP ratio, 1.04{+-}0.09 pHi readings were 7.31{+-}0.23 (calculated by the shift of Pi) and 6.81{+-}0.20 (calculated by the shift of {gamma}-ATP). Pi/PCR was 0.539, a ratio higher than that mentioned in previously published reports. The measurement of intracellular metabolism was affected by various kinds of factors. We believe, however, that pHi readings indicate the overall state of the cardiac intracellular milieu. An unexpected pHi readings, seen at MRS, may reflect errors in the MR procedure itself and, or in the analytical method.

  3. Alcohol intake and colorectal cancer: a comparison of approaches for including repeated measures of alcohol consumption

    DEFF Research Database (Denmark)

    Thygesen, Lau Caspar; Wu, Kana; Grønbaek, Morten

    2008-01-01

    BACKGROUND: In numerous studies, alcohol intake has been found to be positively associated with colorectal cancer risk. However, the majority of studies included only one exposure measurement, which may bias the results if long-term intake is relevant.METHODS: We compared different approaches...... for including repeated measures of alcohol intake among 47,432 US men enrolled in the Health Professionals Follow-up Study. Questionnaires including questions on alcohol intake had been completed in 1986, 1990, 1994, and 1998. The outcome was incident colorectal cancer during follow-up from 1986 to 2002.RESULTS......: During follow-up, 868 members of the cohort experienced colorectal cancer. Baseline, updated, and cumulative average alcohol intakes were positively associated with colorectal cancer, with only minor differences among the approaches. These results support moderately increased risk for intake >30 g...

  4. The effect of a hay grid feeder on feed consumption and measurement of the gastric pH using an intragastric electrode device in horses: a preliminary report.

    Science.gov (United States)

    Aristizabal, F; Nieto, J; Yamout, S; Snyder, J

    2014-07-01

    Obesity and gastric ulceration are highly prevalent in horses. Management modifications for preventing squamous gastric ulceration include frequent feeding and free access to pasture; however, these practices may predispose horses to obesity. To compare the percentage of hay consumed, intragastric pH and horse activity between feeding from the ground and a hay grid feeder. Crossover experimental study. A pH electrode was inserted into the stomach to record the intragastric pH for 48 h. Horses received 1% of their body weight in grass hay twice a day. Horses were assigned to be fed from the ground or a commercial hay grid feeder for 24 h and then switched to the opposite protocol for an additional 24 h. Horses were continuously video-recorded and the percentage of time spent eating or drinking, walking or standing, and lying down were calculated. Two point data were compared by paired t test and pH over time was compared by repeated measures ANOVA. Horses consumed significantly greater amounts of grass hay when fed on the ground compared with a hay grid feeder (n = 9; PpH values (n = 6; P = 0.97), mean intragastric pH over time (n = 6; P = 0.45) the length of time the pH was below 4.0 (n = 6; P = 0.54), and the percentage of time horses spent eating or drinking (n = 9; P = 0.52), walking or standing (n = 9; P = 0.3), or lying down (n = 9; P = 0.4). Within each group horses spent more time eating during the day compared with the night (n = 9; hay grid feeder P = 0.003; ground feeding P = 0.007). The hay grid feeder studied may be used to reduce the amount of hay ingested by horses without reducing the time horses spend eating. © 2013 EVJ Ltd.

  5. Laser induced breakdown spectroscopy of the uranium including calcium. Time resolved measurement spectroscopic analysis (Contract research)

    International Nuclear Information System (INIS)

    Akaoka, Katsuaki; Maruyama, Youichiro; Oba, Masaki; Miyabe, Masabumi; Otobe, Haruyoshi; Wakaida, Ikuo

    2010-05-01

    For the remote analysis of low DF TRU (Decontamination Factor Transuranic) fuel, Laser Breakdown Spectroscopy (LIBS) was applied to uranium oxide including a small amount of calcium oxide. The characteristics, such as spectrum intensity and plasma excitation temperature, were measured using time-resolved spectroscopy. As a result, in order to obtain the stable intensity of calcium spectrum for the uranium spectrum, it was found out that the optimum observation delay time of spectrum is 4 microseconds or more after laser irradiation. (author)

  6. Including health insurance in poverty measurement: The impact of Massachusetts health reform on poverty.

    Science.gov (United States)

    Korenman, Sanders D; Remler, Dahlia K

    2016-12-01

    We develop and implement what we believe is the first conceptually valid health-inclusive poverty measure (HIPM) - a measure that includes health care or insurance in the poverty needs threshold and health insurance benefits in family resources - and we discuss its limitations. Building on the Census Bureau's Supplemental Poverty Measure, we construct a pilot HIPM for the under-65 population under ACA-like health reform in Massachusetts. This pilot demonstrates the practicality, face validity and value of a HIPM. Results suggest that public health insurance benefits and premium subsidies accounted for a substantial, one-third reduction in the health inclusive poverty rate. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. IntelliGO: a new vector-based semantic similarity measure including annotation origin

    Directory of Open Access Journals (Sweden)

    Devignes Marie-Dominique

    2010-12-01

    Full Text Available Abstract Background The Gene Ontology (GO is a well known controlled vocabulary describing the biological process, molecular function and cellular component aspects of gene annotation. It has become a widely used knowledge source in bioinformatics for annotating genes and measuring their semantic similarity. These measures generally involve the GO graph structure, the information content of GO aspects, or a combination of both. However, only a few of the semantic similarity measures described so far can handle GO annotations differently according to their origin (i.e. their evidence codes. Results We present here a new semantic similarity measure called IntelliGO which integrates several complementary properties in a novel vector space model. The coefficients associated with each GO term that annotates a given gene or protein include its information content as well as a customized value for each type of GO evidence code. The generalized cosine similarity measure, used for calculating the dot product between two vectors, has been rigorously adapted to the context of the GO graph. The IntelliGO similarity measure is tested on two benchmark datasets consisting of KEGG pathways and Pfam domains grouped as clans, considering the GO biological process and molecular function terms, respectively, for a total of 683 yeast and human genes and involving more than 67,900 pair-wise comparisons. The ability of the IntelliGO similarity measure to express the biological cohesion of sets of genes compares favourably to four existing similarity measures. For inter-set comparison, it consistently discriminates between distinct sets of genes. Furthermore, the IntelliGO similarity measure allows the influence of weights assigned to evidence codes to be checked. Finally, the results obtained with a complementary reference technique give intermediate but correct correlation values with the sequence similarity, Pfam, and Enzyme classifications when compared to

  8. Spectral interferometry including the effect of transparent thin films to measure distances and displacements

    International Nuclear Information System (INIS)

    Hlubina, P.

    2004-01-01

    A spectral-domain interferometric technique is applied for measuring mirror distances and displacements in a dispersive Michelson interferometer when the effect of transparent thin films coated onto the interferometer beam splitter and compensator is known. We employ a low-resolution spectrometer in two experiments with different amounts of dispersion in a Michelson interferometer that includes fused-silica optical sample. Knowing the thickness of the optical sample and the nonlinear phase function of the thin films, the positions of the interferometer mirror are determined precisely by a least-squares fitting of the theoretical spectral interferograms to the recorded ones. We compare the results of the processing that include and do not include the effect of transparent thin films (Author)

  9. UV-photodegradation of desipramine: Impact of concentration, pH and temperature on formation of products including their biodegradability and toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Khaleel, Nareman D.H.; Mahmoud, Waleed M.M. [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Leuphana University of Lüneburg, Scharnhorststraße 1 C13, DE 21335 Lüneburg (Germany); Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Suez Canal University, Ismailia 41522 (Egypt); Olsson, Oliver [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Leuphana University of Lüneburg, Scharnhorststraße 1 C13, DE 21335 Lüneburg (Germany); Kümmerer, Klaus, E-mail: klaus.kuemmerer@leuphana.de [Sustainable Chemistry and Material Resources, Institute of Sustainable and Environmental Chemistry, Leuphana University of Lüneburg, Scharnhorststraße 1 C13, DE 21335 Lüneburg (Germany)

    2016-10-01

    Desipramine (DMI) is a widely used tricyclic antidepressant, and it is the major metabolite of imipramine (IMI) and lofepramine (LMI); IMI and LMI are two of the most commonly used tricyclic antidepressants. If DMI enters the aquatic environment, it can be transformed by the environmental bacteria or UV radiation. Therefore, photolysis of DMI in water was performed using a simulated sunlight Xenon-lamp and a UV-lamp. Subsequently, the biodegradability of DMI and its photo-transformation products (PTPs) formed during its UV photolysis was studied. The influence of variable conditions, such as initial DMI concentration, solution pH, and temperature, on DMI UV photolysis behavior was also studied. The degree of mineralization of DMI and its PTPs was monitored. A Shimadzu HPLC-UV apparatus was used to follow the kinetic profile of DMI during UV-irradiation; after that, ion-trap and high-resolution mass spectrometry coupled with chromatography were used to monitor and identify the possible PTPs. The environmentally relevant properties and selected toxicity properties of DMI and the non-biodegradable PTPs were predicted using different QSAR models. DMI underwent UV photolysis with first-order kinetics. Quantum yields were very low. DOC values indicated that DMI formed new PTPs and was not completely mineralized. Analysis by means of high-resolution mass spectrometry revealed that the photolysis of DMI followed three main photolysis pathways: isomerization, hydroxylation, and ring opening. The photolysis rate was inversely proportional to initial DMI concentration. The pH showed a significant impact on the photolysis rate of DMI, and on the PTPs in terms of both formation kinetics and mechanisms. Although temperature was expected to increase the photolysis rate, it showed a non-significant impact in this study. Results from biodegradation tests and QSAR analysis revealed that DMI and its PTPs are not readily biodegradable and that some PTPs may be human and/or eco

  10. How to measure PhD. students' conceptions of academic writing - and are they related to well-being?

    Directory of Open Access Journals (Sweden)

    Kirsti Lonka

    2014-02-01

    Full Text Available This study investigated PhD students’ conceptions of writing and how they saw themselves as writers. The Writing Process Questionnaire was created to analyse PhD students’ ideas of academic writing. In addition, it was of interest, what the relation between conceptions of writing and the PhD students’ well-being was. The participants were 669 PhD students from a major Finnish university who volunteered to fill in a questionnaire. The present study covered scales for measuring six distinct theoretical constructs that were created by forming sum variables of 26 questions: Blocks, Procrastination, Perfectionism, Innate ability, Knowledge transforming, and Productivity. Confirmatory factor analysis (CFA was used to verify the six-dimension construct. Exhaustion, stress, anxiety and lack of interest all correlated positively with Blocks, Procrastination, and Perfectionism, and negatively with Productivity. Confirmatory factor analysis conducted by LISREL confirmed the six-factor structure of the writing scale. In conclusion, there is good evidence that the questionnaire is a reliable and valid tool, and it captures some essential aspectsof academic writing process and its emotional dimensions.

  11. 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.

  12. Direct Measurement of pH in Individual Particles via Raman Microspectroscopy and Variation in Acidity with Relative Humidity.

    Science.gov (United States)

    Rindelaub, Joel D; Craig, Rebecca L; Nandy, Lucy; Bondy, Amy L; Dutcher, Cari S; Shepson, Paul B; Ault, Andrew P

    2016-02-18

    Atmospheric aerosol acidity is an important characteristic of aqueous particles, which has been linked to the formation of secondary organic aerosol by catalyzing reactions of oxidized organic compounds that have partitioned to the particle phase. However, aerosol acidity is difficult to measure and traditionally estimated using indirect methods or assumptions based on composition. Ongoing disagreements between experiments and thermodynamic models of particle acidity necessitate improved fundamental understanding of pH and ion behavior in high ionic strength atmospheric particles. Herein, Raman microspectroscopy was used to determine the pH of individual particles (H2SO4+MgSO4) based on sulfate and bisulfate concentrations determined from νs(SO4(2-)) and νs(HSO4(-)), the acid dissociation constant, and activity coefficients from extended Debye-Hückel calculations. Shifts in pH and peak positions of νs(SO4(2-)) and νs(HSO4(-)) were observed as a function of relative humidity. These results indicate the potential for direct spectroscopic determination of pH in individual particles and the need to improve fundamental understanding of ion behavior in atmospheric particles.

  13. Optimization of screen-printed ruthenium dioxide electrodes for pH measurements

    International Nuclear Information System (INIS)

    Wyzkiewicz, I.

    2002-01-01

    Optimization of disposable, screen-printed pH-sensors based on ruthenium dioxide is described in this paper. The electrodes were prepared with the use of thick-film technology. The pH-sensitive layers were deposited onto polyester foil. Polymer graphite paste containing ruthenium dioxide from 0% to 90% has been investigated. The dependence of the pH-sensitive layers related to ruthenium dioxide content is presented. The investigation proved that the electrodes containing 40-60% ruthenium dioxide exhibit linear high sensitivity (∼ 50 mV/pH) in the wide range of pH (2 - 11) as well as very good reproducibility. (author)

  14. Prenatal Triclosan Exposure and Anthropometric Measures Including Anogenital Distance in Danish Infants

    DEFF Research Database (Denmark)

    Lassen, Tina Harmer; Frederiksen, Hanne; Kyhl, Henriette Boye

    2016-01-01

    , Swan SH, Main KM, Andersson AM, Lind DV, Husby S, Wohlfahrt-Veje C, Skakkebæk NE, Jensen TK. 2016. Prenatal triclosan exposure and anthropometric measures including anogenital distance in Danish infants. Environ Health Perspect 124:1261-1268; http://dx.doi.org/10.1289/ehp.1409637.......BACKGROUND: Triclosan (TCS) is widely used as an antibacterial agent in consumer products such as hand soap and toothpaste, and human exposure is widespread. TCS is suspected of having endocrine-disrupting properties, but few human studies have examined the developmental effects of prenatal TCS...

  15. Commentary on guidelines for radiation measurement and treatment of substances including naturally occurring radioactive materials

    International Nuclear Information System (INIS)

    Sakurai, Naoyuki; Ishiguro, Hideharu

    2007-01-01

    Study group on safety regulation on research reactors in Ministry of Education, Culture, Sports, Science and Technology (MEXT) reported the guidelines of 'Guidelines on radiation measurement and treatment of naturally occurring radioactive materials (NORM)' on 6 February 2006. RANDEC made the website contents 'Study on use and safety of the substances including uranium or thorium', based on the contract with MEXT to make theirs contents. This paper describes the outline of the website in MEXT homepage, background and contents of NORM guidelines in order to understand easily and visually the NORM guidelines, adding in some flowcharts and figures. (author)

  16. Prevalence of oral lesions and measurement of salivary pH in the different trimesters of pregnancy.

    Science.gov (United States)

    Jain, Kanu; Kaur, Harshaminder

    2015-01-01

    Oral changes observed during pregnancy have been studied for many years, but their magnitude and frequency have not been stressed upon. This study was undertaken to assess the prevalence of oral lesions during different trimesters of pregnancy and their correlation with salivary pH change. The gingival, simplified oral hygiene, community periodontal and decayed-missing-filled teeth indices were used to assess a total of 120 pregnant women (40 in each trimester group) and 40 nonpregnant women (control group). Salivary pH was measured using a digital pH meter. Presence of any oral lesions was determined via oral examination. Scores for all indices increased while salivary pH decreased from the control group to the first trimester group, through to the third. Oral lesions were seen in 44.2% of pregnant women. Lesions were seen in 27.5%, 52.5% and 52.5% of women in the first, second and third trimesters, respectively. The percentage of pregnant women with one oral lesion was highest in the second trimester (47.5%), whereas the third trimester had the highest prevalence (17.5%) of two concurrent oral lesions. The incidence of fissured tongue was highest in the first trimester group, and that of gingival enlargement was highest in the third trimester group. In the second trimester group, there was an almost equal incidence of fissured tongue and gingival/mucosal enlargement. Most changes in oral tissues during pregnancy can be avoided with good oral hygiene. Salivary pH could be used to assess the prevalence of oral lesions in the different trimesters of pregnancy.

  17. The measurement of the temperature, pH and the electric properties of the liquid of the borehole

    International Nuclear Information System (INIS)

    Duran, O.; Magnusson, K.Aa.

    1980-05-01

    Some new measurement methods to log variations of properties in a borehole have been described. The measurements have been made 'in situ' at resp Kraakemaala, Finnsjoen and Studsvik, all in Sweden. The investigation is assumed to give evidence of the fissures in the bedrock. The work is part of a programme concerning waste management. The following properties in boreholes are presented in a number of graphs: temperature, liquid resistivity, pH, self potentials and redox potentials. The experimental results are reproducible and systematic. (G.B.)

  18. PH in Rockwool Propagation Blocks: a Method to Measure the pH Buffer Capacity of Rockwool and Other Mineral Wool Media

    NARCIS (Netherlands)

    Blok, C.; Kaarsemaker, R.C.

    2013-01-01

    Within the framework of the international KIWA quality label for rooting media representatives of plant propagators and the rockwool industry agreed to develop a method to characterize the influence of the rooting medium materials on the pH in cultivation. A method for the characterization of

  19. Validity of a questionnaire measuring motives for choosing foods including sustainable concerns.

    Science.gov (United States)

    Sautron, Valérie; Péneau, Sandrine; Camilleri, Géraldine M; Muller, Laurent; Ruffieux, Bernard; Hercberg, Serge; Méjean, Caroline

    2015-04-01

    Since the 1990s, sustainability of diet has become an increasingly important concern for consumers. However, there is no validated multidimensional measurement of motivation in the choice of foods including a concern for sustainability currently available. In the present study, we developed a questionnaire that measures food choice motives during purchasing, and we tested its psychometric properties. The questionnaire included 104 items divided into four predefined dimensions (environmental, health and well-being, economic and miscellaneous). It was administered to 1000 randomly selected subjects participating in the Nutrinet-Santé cohort study. Among 637 responders, one-third found the questionnaire complex or too long, while one-quarter found it difficult to fill in. Its underlying structure was determined by exploratory factor analysis and then internally validated by confirmatory factor analysis. Reliability was also assessed by internal consistency of selected dimensions and test-retest repeatability. After selecting the most relevant items, first-order analysis highlighted nine main dimensions: labeled ethics and environment, local and traditional production, taste, price, environmental limitations, health, convenience, innovation and absence of contaminants. The model demonstrated excellent internal validity (adjusted goodness of fit index = 0.97; standardized root mean square residuals = 0.07) and satisfactory reliability (internal consistency = 0.96, test-retest repeatability coefficient ranged between 0.31 and 0.68 over a mean 4-week period). This study enabled precise identification of the various dimensions in food choice motives and proposed an original, internally valid tool applicable to large populations for assessing consumer food motivation during purchasing, particularly in terms of sustainability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. 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...

  1. Constraints on inflation revisited. An analysis including the latest local measurement of the Hubble constant

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Rui-Yun [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Zhang, Xin [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Peking University, Center for High Energy Physics, Beijing (China)

    2017-12-15

    We revisit the constraints on inflation models by using the current cosmological observations involving the latest local measurement of the Hubble constant (H{sub 0} = 73.00 ± 1.75 km s{sup -1} Mpc{sup -1}). We constrain the primordial power spectra of both scalar and tensor perturbations with the observational data including the Planck 2015 CMB full data, the BICEP2 and Keck Array CMB B-mode data, the BAO data, and the direct measurement of H{sub 0}. In order to relieve the tension between the local determination of the Hubble constant and the other astrophysical observations, we consider the additional parameter N{sub eff} in the cosmological model. We find that, for the ΛCDM+r+N{sub eff} model, the scale invariance is only excluded at the 3.3σ level, and ΔN{sub eff} > 0 is favored at the 1.6σ level. Comparing the obtained 1σ and 2σ contours of (n{sub s},r) with the theoretical predictions of selected inflation models, we find that both the convex and the concave potentials are favored at 2σ level, the natural inflation model is excluded at more than 2σ level, the Starobinsky R{sup 2} inflation model is only favored at around 2σ level, and the spontaneously broken SUSY inflation model is now the most favored model. (orig.)

  2. Non-invasive technique to measure biogeochemical parameters (pH and O2) in a microenvironment: Design and applications

    Science.gov (United States)

    Li, Biting; Seliman, Ayman; Pales, Ashley; Liang, Weizhen; Sams, Allison; Darnault, Christophe; Devol, Timothy

    2017-04-01

    The primary objectives of this research are to do the pH and O2 sensor foils calibration and then to test them in applications. Potentially, this project can be utilized to monitor the fate and transport of radionuclides in porous media. The information for physical and chemical parameters (e.g. pH and O2) is crucial to know when determining contaminants' behavior and transport in the environment. As a non-invasive method, optical imaging technique using a DSLR camera could capture data on the foil when it fluoresces, and gives a high temporal and spatial resolution during the experimental period. The calibration procedures were done in cuvettes in a row. The preliminary experiments could measure pH value in the range from 4.5 to 7.5, and O2 concentration from 0 mg/L to 20.74 mg/L. Applications of sensor foils have involved nano zero valent and acid rain experiments in order to obtain a gradient of parameter changes.

  3. Incidence of spontaneous bacterial peritonitis in patients with ascites. Diagnostic value of white blood cell count and pH measurement in ascitic fluid

    DEFF Research Database (Denmark)

    Storgaard, J S; Svendsen, Jesper Hastrup; Hegnhøj, J

    1991-01-01

    During a 21-month period, 65 consecutive patients admitted with ascites were included in a prospective study of the incidence of spontaneous bacterial peritonitis, and paracentesis was performed on admission. The ascitic fluid was cultured, ascitic leucocytes were counted and pH was measured....... Bacterial growth was found in five patients with chronic liver disease, who were diagnosed as having spontaneous bacterial peritonitis (SBP), since no intra-abdominal focus could be demonstrated. Thus, the incidence of SBP in this material was 7.7% (95% confidence limits: 2.5-17%). SBP was caused...

  4. PhD Dissertation Proposal - Introduction to Dark Mix Concept: Gamma Measurements of Capsule Mixture

    Energy Technology Data Exchange (ETDEWEB)

    Meaney, Kevin Daniel [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-06

    Presentation slides: Intro to Inertial Confinement Fusion; Types of Mixture in ICF capsules; Previous mixture experiments; Dark Mix Concept; Measuring Dark Mix with Gamma Cherenkov Detector; Dissertation Outline.

  5. 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 ...

  6. Future global manpower shortages in nuclear industries with special reference to india including remedial measures

    International Nuclear Information System (INIS)

    Ghosh Hazra, G.S.

    2008-01-01

    -2050. Service sector in India accounts for about 50% of GDP which will continue to increase further and will provide more jobs and better paid jobs than core industries and there will be continued shift of choice of employment towards service sector creating deep gap of manpower resource requirement in basic and core industries. There are reports that some countries may have to abandon some future projects because of non availability skilled manpower in core industries. The installed capacity of nuclear power in India in the year 2052 will be about 200 G We from the present about 4 G We which will be a manifold increase. This will need about estimated 1,30,000 skilled manpower from the present about 12,000 persons in nuclear industries. Moreover, the need for competent persons in nuclear industries because of high safety requirements of nuclear installations will further add to the problem. The following short-term strategies to retain and attract new employees in nuclear industries may be envisaged amongst others: - Recruit employees prior to the departure of experienced technical staff to facilitate knowledge transfer in time. - Increase compensation and the number of higher level positions. - Increase permanent entry-level intake of skilled manpower taking into account historical turn-over rate. - Implement attractive student loan repayment programs by tying up with banks and financial institutions. - Implement well researched strategies and measures including reassessing the practical capacity which nations including India can achieve in power generation in future taking practical aspects of manpower shortage. - Implement advanced technology which requires lesser manpower. - Implement higher level of automation in nuclear industries. The paper aims to highlight the acute problems of future manpower shortages in nuclear industries globally with special reference to India and discusses some remedial measures which may be taken to address the issue. (author)

  7. Measurement of pH, alkalinity and acidity in ultra-soft waters

    African Journals Online (AJOL)

    drinie

    The paper is a very welcome addition to improving these measurements of natural waters, not only because of the techniques used but also because the approach is based on a detailed analysis of the fundamentals of carbonate chemistry in these waters. However, the paper appears to overlook the significance of.

  8. Development of a downhole tool measuring real-time concentration of ionic tracers and pH in geothermal reservoirs

    Science.gov (United States)

    Hess, Ryan F.; Boyle, Timothy J.; Limmer, Steven; Yelton, William G.; Bingham, Samuel; Stillman, Greg; Lindblom, Scott; Cieslewski, Grzegorz

    2014-06-01

    For enhanced or Engineered Geothermal Systems (EGS) geothermal brine is pumped to the surface via the production wells, the heat extracted to turn a turbine to generate electricity, and the spent brine re-injected via injection wells back underground. If designed properly, the subsurface rock formations will lead this water back to the extraction well as heated brine. Proper monitoring of these geothermal reservoirs is essential for developing and maintaining the necessary level of productivity of the field. Chemical tracers are commonly used to characterize the fracture network and determine the connectivity between the injection and production wells. Currently, most tracer experiments involve injecting the tracer at the injection well, manually collecting liquid samples at the wellhead of the production well, and sending the samples off for laboratory analysis. While this method provides accurate tracer concentration data at very low levels of detection, it does not provide information regarding the location of the fractures which were conducting the tracer between wellbores. Sandia is developing a high-temperature electrochemical sensor capable of measuring tracer concentrations and pH downhole on a wireline tool. The goal of this effort is to collect real-time pH and ionic tracer concentration data at temperatures up to 225 °C and pressures up to 3000 psi. In this paper, a prototype electrochemical sensor and the initial data obtained will be presented detailing the measurement of iodide tracer concentrations at high temperature and pressure in a newly developed laboratory scale autoclave.

  9. ORP and pH measurements to detect redox and acid-base anomalies from hydrothermal activity

    Science.gov (United States)

    Santana-Casiano, J. M.; González-Dávila, M.; Fraile-Nuez, E.

    2017-12-01

    The Tagoro submarine volcano is located 1.8 km south of the Island of El Hierro at 350 m depth and rises up to 88 m below sea level. It was erupting melting material for five months, from October 2011 to March 2012, changing drastically the physical-chemical properties of the water column in the area. After this eruption, the system evolved to a hydrothermal system. The character of both reduced and acid of the hydrothermal emissions in the Tagoro submarine volcano allowed us to detect anomalies related with changes in the chemical potential and the proton concentration using ORP and pH sensors, respectively. Tow-yos using a CTD-rosette with these two sensors provided the locations of the emissions plotting δ(ORP)/δt and ΔpH versus the latitude or longitude. The ORP sensor responds very quickly to the presence of reduced chemicals in the water column. Changes in potential are proportional to the amount of reduced chemical species present in the water. The magnitude of these changes are examined by the time derivative of ORP, δ(ORP)/δt. To detect changes in the pH, the mean pH for each depth at a reference station in an area not affected by the vent emission is subtracted from each point measured near the volcanic edifice, defining in this way ΔpH. Detailed surveys of the volcanic edifice were carried out between 2014 and 2016 using several CTD-pH-ORP tow-yo studies, localizing the ORP and pH changes, which were used to obtain surface maps of anomalies. Moreover, meridional tow-yos were used to calculate the amount of volcanic CO2 added to the water column. The inputs of CO2 along multiple sections combined with measurements of oceanic currents produced an estimated volcanic CO2 flux = 6.0 105 ± 1.1 105 kg d-1 which increases the acidity above the volcano by 20%. Sites like the Tagoro submarine volcano, in its degasification stage, provide an excellent opportunity to study the carbonate system in a high CO2 world, the volcanic contribution to the global

  10. Measurement network design including traveltime determinations to minimize model prediction uncertainty

    NARCIS (Netherlands)

    Janssen, G.M.C.M.; Valstar, J.R.; Zee, van der S.E.A.T.M.

    2008-01-01

    Traveltime determinations have found increasing application in the characterization of groundwater systems. No algorithms are available, however, to optimally design sampling strategies including this information type. We propose a first-order methodology to include groundwater age or tracer arrival

  11. De Svante Arrhenius ao peagâmetro digital: 100 anos de medida de acidez From Svante Arrhenius to the digital ph meter: a century of acidity measurement

    Directory of Open Access Journals (Sweden)

    Michelle da Silva Gama

    2007-02-01

    Full Text Available This work describes the establishment of the concept of pH and the evolution of its measurement. The origin of the pH definition can be found in the development of the chemistry of aqueous solutions during the XIXth century. The electrolytic dissociation theory by Svante Arrhenius played a central role. After the proposal of the pH scale by Sörensen, many years were necessary for the acceptance of this new parameter among chemists in general. Its importance was first recognized in biochemistry and related areas. Twenty years after, its importance had been recognized in many industrial and laboratorial practices. The previous methods were based on colorimetric and electrometric methods, but both suffered from many problems. Acceptance of pH in Chemistry was only possible after the development of experimental trustable measurements. The invention of the pH meter was the primordial step.

  12. A climate index derived from satellite measured spectral infrared radiation. Ph.D. Thesis

    Science.gov (United States)

    Abel, M. D.; Fox, S. K.

    1982-01-01

    The vertical infrared radiative emitting structure (VIRES) climate index, based on radiative transfer theory and derived from the spectral radiances typically used to retrieve temperature profiles, is introduced. It is assumed that clouds and climate are closely related and a change in one will result in a change in the other. The index is a function of the cloud, temperature, and moisture distributions. It is more accurately retrieved from satellite data than is cloudiness per se. The VIRES index is based upon the shape and relative magnitude of the broadband weighting function of the infrared radiative transfer equation. The broadband weighting curves are retrieved from simulated satellite infrared sounder data (spectral radiances). The retrieval procedure is described and the error error sensitivities of the method investigated. Index measuring options and possible applications of the VIRES index are proposed.

  13. Experimental measurements of the solubilities of selected long-lived fission products, activation products and actinide daughters under high pH conditions

    International Nuclear Information System (INIS)

    Pilkington, N.J.; Shadbolt, P.J.; Wilkins, J.D.

    1988-05-01

    Solubility measurements of several elements have been attempted under high pH and oxic conditions in a range of concrete leachates. The elements investigated were niobium, tin, selenium, lead and thorium. (author)

  14. PDF uncertainties in precision electroweak measurements, including the W mass, in ATLAS

    CERN Document Server

    Cooper-Sarkar, Amanda; The ATLAS collaboration

    2015-01-01

    Now that the Higgs mass is known all the parameters of the SM are known- but with what accuracy? Precision EW measurements test the self-consistency of the SM- and thus can give hints of BSM physics. Precision measurements of $sin^2\\theta _W$ and the W mass are limited by PDF uncertainties This contribution discusses these uncertainties and what can be done to improve them.

  15. Measuring system for in situ measurements of pH, Eh, pS2-,SP and temperature in boreholes

    International Nuclear Information System (INIS)

    Johansson, B.-E.; Lund, J.

    1981-01-01

    The instrument has a computer controlled measuring system and an improved design of electrodes and connections. The electrode potential is digitalized in the probe and is transferred via optocouplings to the central unit to be stored on band or on printer tape. Preliminary tests are presented. (G.B.)

  16. Final report on CCQM-K9.2 : subsequent key comparison on pH determination of phosphate buffer by Harned cell measurements

    OpenAIRE

    Spitzer, Petra; Giera, Janine; Fraga, Isabel Cristina Serta; Jakobsen, Pia Tonnes; Jensen, Hans D.; Hyllested, Peter; Karpov, Oleg; Kutovoy, Viatcheslav; Nakamura, Susumu; Vospelova, Alena; Zvezdina, Valentina

    2008-01-01

    CCQM-K9.2 was performed supplementary to the key comparison CCQM-K9 [1] on the pH determination of a phosphate buffer with nominal pH ~ 6.9 (at 25 °C). The sample composition was very similar in both comparisons. Only the source of the starting material used for sample preparation was different. The comparison was restricted to the use of the primary method for pH (Harned cell measurement) as defined in the IUPAC Recommendations [2]. The measurement temperatures were15 °C, 25 °C , 37...

  17. Constraining dark energy with Hubble parameter measurements: an analysis including future redshift-drift observations

    International Nuclear Information System (INIS)

    Guo, Rui-Yun; Zhang, Xin

    2016-01-01

    The nature of dark energy affects the Hubble expansion rate (namely, the expansion history) H(z) by an integral over w(z). However, the usual observables are the luminosity distances or the angular diameter distances, which measure the distance.redshift relation. Actually, the property of dark energy affects the distances (and the growth factor) by a further integration over functions of H(z). Thus, the direct measurements of the Hubble parameter H(z) at different redshifts are of great importance for constraining the properties of dark energy. In this paper, we show how the typical dark energy models, for example, the ΛCDM, wCDM, CPL, and holographic dark energy models, can be constrained by the current direct measurements of H(z) (31 data used in total in this paper, covering the redshift range of z @ element of [0.07, 2.34]). In fact, the future redshift-drift observations (also referred to as the Sandage-Loeb test) can also directly measure H(z) at higher redshifts, covering the range of z @ element of [2, 5]. We thus discuss what role the redshift-drift observations can play in constraining dark energy with the Hubble parameter measurements. We show that the constraints on dark energy can be improved greatly with the H(z) data from only a 10-year observation of redshift drift. (orig.)

  18. High-resolution gamma ray attenuation density measurements on mining exploration drill cores, including cut cores

    Science.gov (United States)

    Ross, P.-S.; Bourke, A.

    2017-01-01

    Physical property measurements are increasingly important in mining exploration. For density determinations on rocks, one method applicable on exploration drill cores relies on gamma ray attenuation. This non-destructive method is ideal because each measurement takes only 10 s, making it suitable for high-resolution logging. However calibration has been problematic. In this paper we present new empirical, site-specific correction equations for whole NQ and BQ cores. The corrections force back the gamma densities to the "true" values established by the immersion method. For the NQ core caliber, the density range extends to high values (massive pyrite, 5 g/cm3) and the correction is thought to be very robust. We also present additional empirical correction factors for cut cores which take into account the missing material. These "cut core correction factors", which are not site-specific, were established by making gamma density measurements on truncated aluminum cylinders of various residual thicknesses. Finally we show two examples of application for the Abitibi Greenstone Belt in Canada. The gamma ray attenuation measurement system is part of a multi-sensor core logger which also determines magnetic susceptibility, geochemistry and mineralogy on rock cores, and performs line-scan imaging.

  19. Noninvasive, near infrared spectroscopic-measured muscle pH and PO2 indicate tissue perfusion for cardiac surgical patients undergoing cardiopulmonary bypass

    Science.gov (United States)

    Soller, Babs R.; Idwasi, Patrick O.; Balaguer, Jorge; Levin, Steven; Simsir, Sinan A.; Vander Salm, Thomas J.; Collette, Helen; Heard, Stephen O.

    2003-01-01

    OBJECTIVE: To determine whether near infrared spectroscopic measurement of tissue pH and Po2 has sufficient accuracy to assess variation in tissue perfusion resulting from changes in blood pressure and metabolic demand during cardiopulmonary bypass. DESIGN: Prospective clinical study. SETTING: Academic medical center. SUBJECTS: Eighteen elective cardiac surgical patients. INTERVENTION: Cardiac surgery under cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: A near infrared spectroscopic fiber optic probe was placed over the hypothenar eminence. Reference Po2 and pH sensors were inserted in the abductor digiti minimi (V). Data were collected every 30 secs during surgery and for 6 hrs following cardiopulmonary bypass. Calibration equations developed from one third of the data were used with the remaining data to investigate sensitivity of the near infrared spectroscopic measurement to physiologic changes resulting from cardiopulmonary bypass. Near infrared spectroscopic and reference pH and Po2 measurements were compared for each subject using standard error of prediction. Near infrared spectroscopic pH and Po2 at baseline were compared with values during cardiopulmonary bypass just before rewarming commenced (hypotensive, hypothermic), after rewarming (hypotensive, normothermic) just before discontinuation of cardiopulmonary bypass, and at 6 hrs following cardiopulmonary bypass (normotensive, normothermic) using mixed-model analysis of variance. Near infrared spectroscopic pH and Po2 were well correlated with the invasive measurement of pH (R2 =.84) and Po2 (R 2 =.66) with an average standard error of prediction of 0.022 +/- 0.008 pH units and 6 +/- 3 mm Hg, respectively. The average difference between the invasive and near infrared spectroscopic measurement was near zero for both the pH and Po2 measurements. Near infrared spectroscopic Po2 significantly decreased 50% on initiation of cardiopulmonary bypass and remained depressed throughout the bypass and

  20. Continuous measurement of reticuloruminal pH values in dairy cows during the transition period from barn to pasture feeding using an indwelling wireless data transmitting unit.

    Science.gov (United States)

    Gasteiner, J; Horn, M; Steinwidder, A

    2015-04-01

    This study was performed to investigate the effect of the transition from barn feeding to pasture on the pattern of reticuloruminal pH values in 8 multiparous dairy cows. A indwelling wireless data transmitting system for pH measurement was given to 8 multiparous cows orally. Reticuloruminal pH values were measured every 600 s over a period of 42 days. After 7 days of barn feeding (period 1), all of the animals were pastured with increasing grazing times from 2 to 7 h/day over 7 days (period 2). From day 15 to day 21 (period 3), the cows spent 7 h/day on pasture. Beginning on day 22, the animals had 20 h/day access to pasture (day and night grazing). To study reticuloruminal adaptation to pasture feeding, the phase of day and night grazing was subdivided into another 3 weekly periods (periods 4-6). Despite a mild transition period from barn feeding to pasture, significant effects on reticuloruminal pH values were observed. During barn feeding, the mean reticuloruminal pH value for all of the cows was 6.44 ± 0.14, and the pH values decreased significantly (p pH values increased again (pH 6.25 ± 0.22; pH 6.31 ± 0.17; pH 6.37 ± 0.16). Our results showed that the animals had significantly lowered reticuloruminal pH during the periods of feed transition from barn to pasture feeding. Despite these significant changes, the decrease was not harmful, as indicated by data of feed intake and milk production. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  1. Simultaneous measurements of work function and H‒ density including caesiation of a converter surface

    Science.gov (United States)

    Cristofaro, S.; Friedl, R.; Fantz, U.

    2017-08-01

    Negative hydrogen ion sources rely on the surface conversion of neutral atomic hydrogen and positive hydrogen ions to H-. The efficiency of this process depends on the actual work function of the converter surface. By introducing caesium into the source the work function decreases, enhancing the negative ion yield. In order to study the impact of the work function on the H- surface production at similar conditions to the ones in ion sources for fusion devices like ITER and DEMO, fundamental investigations are performed in a flexible laboratory experiment. The work function of the converter surface can be absolutely measured by photoelectric effect, while a newly installed cavity ring-down spectroscopy system (CRDS) measures the H- density. The CRDS is firstly tested and characterized by investigations on H- volume production. Caesiation of a stainless steel sample is then performed in vacuum and the plasma effect on the Cs layer is investigated also for long plasma-on times. A minimum work function of (1.9±0.1) eV is reached after some minutes of plasma treatment, resulting in a reduction by a value of 0.8 eV compared to vacuum measurements. The H- density above the surface is (2.1±0.5)×1015 m-3. With further plasma exposure of the caesiated surface, the work function increases up to 3.75 eV, due to the impinging plasma particles which gradually remove the Cs layer. As a result, the H- density decreases by a factor of at least 2.

  2. Multiple shooting applied to robust reservoir control optimization including output constraints on coherent risk measures

    DEFF Research Database (Denmark)

    Codas, Andrés; Hanssen, Kristian G.; Foss, Bjarne

    2017-01-01

    The production life of oil reservoirs starts under significant uncertainty regarding the actual economical return of the recovery process due to the lack of oil field data. Consequently, investors and operators make management decisions based on a limited and uncertain description of the reservoir....... In this work, we propose a new formulation for robust optimization of reservoir well controls. It is inspired by the multiple shooting (MS) method which permits a broad range of parallelization opportunities and output constraint handling. This formulation exploits coherent risk measures, a concept...

  3. Cost and benefit including value of life, health and environmental damage measured in time units

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager; Friis-Hansen, Peter

    2009-01-01

    Key elements of the authors' work on money equivalent time allocation to costs and benefits in risk analysis are put together as an entity. This includes the data supported dimensionless analysis of an equilibrium relation between total population work time and gross domestic product leading...... of this societal value over the actual costs, used by the owner for economically optimizing an activity, motivates a simple risk accept criterion suited to be imposed on the owner by the public. An illustration is given concerning allocation of economical means for mitigation of loss of life and health on a ferry...

  4. A new approach to pH of point of zero charge measurement: crystal-face specificity by scanning force microscopy (SFM)

    Science.gov (United States)

    Eggleston, Carrick M.; Jordan, Guntram

    1998-06-01

    The pH of point of zero charge (pH pzc) is a fundamentally important property used in modeling the interaction of solid surfaces with aqueous solutions and solutes. The pH pzc is normally measured by acid-base titration of solid suspensions. Here, a scanning force microscope (SFM) is used to measure forces of repulsion or attraction between chemically tailored tips and quartz (101) and hematite (001) surfaces, as a function of tip-surface separation and pH. The force at contact (FAC) is at a minimum near the expected point of pH pzc for a chemically similar tip and sample. The results are compared to predicted interaction forces from a simple DLVO model, which shows that the SFM technique for pH pzc measurement is most promising for surfaces (such as iron oxides) that have not-too-widely spaced pK a1 and pK a2 values for surface site deprotonation. However, improvements in precision will be necessary to fully utilize the technique. The SFM approach to pH pzc measurement may in future allow the measurement of crystal-face-specific pH pzc, rather than a weighted average of all exposed surface sites, and thus allow us to ask better-defined structure-reactivity questions for mineral surfaces. The approach can in theory be extended to the single-site scale in order to probe the properties (e.g., potential and charge) of individual terrace, step, or kink sites.

  5. Gravity-driven pH adjustment for site-specific protein pKa measurement by solution-state NMR

    Science.gov (United States)

    Li, Wei

    2017-12-01

    To automate pH adjustment in site-specific protein pKa measurement by solution-state NMR, I present a funnel with two caps for the standard 5 mm NMR tube. The novelty of this simple-to-build and inexpensive apparatus is that it allows automatic gravity-driven pH adjustment within the magnet, and consequently results in a fully automated NMR-monitored pH titration without any hardware modification on the NMR spectrometer.

  6. Design and Optimization of Capacitated Supply Chain Networks Including Quality Measures

    Directory of Open Access Journals (Sweden)

    Krystel K. Castillo-Villar

    2014-01-01

    Full Text Available This paper presents (1 a novel capacitated model for supply chain network design which considers manufacturing, distribution, and quality costs (named SCND-COQ model and (2 five combinatorial optimization methods, based on nonlinear optimization, heuristic, and metaheuristic approaches, which are used to solve realistic instances of practical size. The SCND-COQ model is a mixed-integer nonlinear problem which can be used at a strategic planning level to design a supply chain network that maximizes the total profit subject to meeting an overall quality level of the final product at minimum costs. The SCND-COQ model computes the quality-related costs for the whole supply chain network considering the interdependencies among business entities. The effectiveness of the proposed solution approaches is shown using numerical experiments. These methods allow solving more realistic (capacitated supply chain network design problems including quality-related costs (inspections, rework, opportunity costs, and others within a reasonable computational time.

  7. An assessment of PCB degradation by microogransims including methods for measuring mineralization

    Energy Technology Data Exchange (ETDEWEB)

    Hadden, C.; Edenborn, H.; Osborne, T.; Holdsworth, G.; Revis, N.

    1990-12-31

    These studies sought to isolate and identify organism(s) from PCB contaminated soil and sediment that degrade PCB; to provide information on the potential of organisms in soil samples taken from a PCB-contaminated area to mineralize or dechlorinate PCB congeners; to assess potential enhancement of PCB biodegradation as a result of nutritional amendment of the samples; and to carry out analyses of successive lysimeter samples to determine whether field treatments have had an effect on the capacity of soil microbes to mineralize PCBS. We have expended considerable effort to validate the fractionation procedure used to assess mineralization and conversion of PCB substrates. The assessment relies on the ability to measure [{sup 14}C]-labeled CO{sub 2} in the presence of potentially volatile [{sup 14}C]-labeled PCB and degradation products to differentiate between volatile and non-volatile [{sup 14}C]-labeled compounds between water-soluble products of metabolism and a mixture of unchanged substrate and other water-insoluble products and between metabolism and loss or non-extractability of the substrate.

  8. An assessment of PCB degradation by microogransims including methods for measuring mineralization

    International Nuclear Information System (INIS)

    Hadden, C.; Edenborn, H.; Osborne, T.; Holdsworth, G.; Revis, N.

    1990-01-01

    These studies sought to isolate and identify organism(s) from PCB contaminated soil and sediment that degrade PCB; to provide information on the potential of organisms in soil samples taken from a PCB-contaminated area to mineralize or dechlorinate PCB congeners; to assess potential enhancement of PCB biodegradation as a result of nutritional amendment of the samples; and to carry out analyses of successive lysimeter samples to determine whether field treatments have had an effect on the capacity of soil microbes to mineralize PCBS. We have expended considerable effort to validate the fractionation procedure used to assess mineralization and conversion of PCB substrates. The assessment relies on the ability to measure [ 14 C]-labeled CO 2 in the presence of potentially volatile [ 14 C]-labeled PCB and degradation products to differentiate between volatile and non-volatile [ 14 C]-labeled compounds between water-soluble products of metabolism and a mixture of unchanged substrate and other water-insoluble products and between metabolism and loss or non-extractability of the substrate

  9. Low impedance pH sensitive electrochemical devices that are potentially applicable to transcutaneous PCO2 measurements.

    Science.gov (United States)

    Yeung, H N; Beran, A V; Huxtable, R F

    1978-01-01

    Two cases of low impedance, non-glass membrane electrodes for pH measurement were evaluated: (I) Metal--metal oxide electrodes and (II) Reduction-oxidation electrodes. The fundamental cause of oxygen sensitivity of metal-metal oxide electrodes were examined and three approaches for its suppression were proposed. For the case of Sb--Sb2Ox electordes, oxygen sensitivity can be attenuated partially by cell loading, either directly across the reference electrode or indirectly across a third slave electrode. In a PO2 range of 8--54 kPa, more than 95% of the PO2 response can be suppressed by loading the cell emf to half of tis open-circuit value. The oxygen sensitivity also was observed to diminished by grinding the metal-metal oxide and pressing it under high pressure into a pellet electrode. Other metal-metal oxide electrodes that have promise in transcutaneous measurement are the Pd-PdO2 electrodes. The redox electrodes are typified by the Quinhydrone electrode. A membrane Quinhydrome electrode showed a sensitivity of 56 mV/Decade at 37 degree C and no oxygen sensitivity up to 50 kPa and a drift of 1 mV/h over a 24-h period. However, the stability deteriorated over a long-term period.

  10. Metrological challenges for measurements of key climatological observables: oceanic salinity and pH, and atmospheric humidity. Part 1: overview

    Science.gov (United States)

    Feistel, R.; Wielgosz, R.; Bell, S. A.; Camões, M. F.; Cooper, J. R.; Dexter, P.; Dickson, A. G.; Fisicaro, P.; Harvey, A. H.; Heinonen, M.; Hellmuth, O.; Kretzschmar, H.-J.; Lovell-Smith, J. W.; McDougall, T. J.; Pawlowicz, R.; Ridout, P.; Seitz, S.; Spitzer, P.; Stoica, D.; Wolf, H.

    2016-02-01

    Water in its three ambient phases plays the central thermodynamic role in the terrestrial climate system. Clouds control Earth’s radiation balance, atmospheric water vapour is the strongest ‘greenhouse’ gas, and non-equilibrium relative humidity at the air-sea interface drives evaporation and latent heat export from the ocean. On climatic time scales, melting ice caps and regional deviations of the hydrological cycle result in changes of seawater salinity, which in turn may modify the global circulation of the oceans and their ability to store heat and to buffer anthropogenically produced carbon dioxide. In this paper, together with three companion articles, we examine the climatologically relevant quantities ocean salinity, seawater pH and atmospheric relative humidity, noting fundamental deficiencies in the definitions of those key observables, and their lack of secure foundation on the International System of Units, the SI. The metrological histories of those three quantities are reviewed, problems with their current definitions and measurement practices are analysed, and options for future improvements are discussed in conjunction with the recent seawater standard TEOS-10. It is concluded that the International Bureau of Weights and Measures, BIPM, in cooperation with the International Association for the Properties of Water and Steam, IAPWS, along with other international organizations and institutions, can make significant contributions by developing and recommending state-of-the-art solutions for these long standing metrological problems in climatology.

  11. Potential of on-line visible and near infrared spectroscopy for measurement of pH for deriving variable rate lime recommendations.

    Science.gov (United States)

    Tekin, Yücel; Kuang, Boyan; Mouazen, Abdul M

    2013-08-08

    This paper aims at exploring the potential of visible and near infrared (vis-NIR) spectroscopy for on-line measurement of soil pH, with the intention to produce variable rate lime recommendation maps. An on-line vis-NIR soil sensor set up to a frame was used in this study. Lime application maps, based on pH predicted by vis-NIR techniques, were compared with maps based on traditional lab-measured pH. The validation of the calibration model using off-line spectra provided excellent prediction accuracy of pH (R2 = 0.85, RMSEP = 0.18 and RPD = 2.52), as compared to very good accuracy obtained with the on-line measured spectra (R2 = 0.81, RMSEP = 0.20 and RPD = 2.14). On-line predicted pH of all points (e.g., 2,160) resulted in the largest overall field virtual lime requirement (1.404 t), as compared to those obtained with 16 validation points off-line prediction (0.28 t), on-line prediction (0.14 t) and laboratory reference measurement (0.48 t). The conclusion is that the vis-NIR spectroscopy can be successfully used for the prediction of soil pH and for deriving lime recommendations. The advantage of the on-line sensor over sampling with limited number of samples is that more detailed information about pH can be obtained, which is the reason for a higher but precise calculated lime recommendation rate.

  12. Potential of On-Line Visible and Near Infrared Spectroscopy for Measurement of pH for Deriving Variable Rate Lime Recommendations

    Directory of Open Access Journals (Sweden)

    Yücel Tekin

    2013-08-01

    Full Text Available This paper aims at exploring the potential of visible and near infrared (vis-NIR spectroscopy for on-line measurement of soil pH, with the intention to produce variable rate lime recommendation maps. An on-line vis-NIR soil sensor set up to a frame was used in this study. Lime application maps, based on pH predicted by vis-NIR techniques, were compared with maps based on traditional lab-measured pH. The validation of the calibration model using off-line spectra provided excellent prediction accuracy of pH (R2 = 0.85, RMSEP = 0.18 and RPD = 2.52, as compared to very good accuracy obtained with the on-line measured spectra (R2 = 0.81, RMSEP = 0.20 and RPD = 2.14. On-line predicted pH of all points (e.g., 2,160 resulted in the largest overall field virtual lime requirement (1.404 t, as compared to those obtained with 16 validation points off-line prediction (0.28 t, on-line prediction (0.14 t and laboratory reference measurement (0.48 t. The conclusion is that the vis-NIR spectroscopy can be successfully used for the prediction of soil pH and for deriving lime recommendations. The advantage of the on-line sensor over sampling with limited number of samples is that more detailed information about pH can be obtained, which is the reason for a higher but precise calculated lime recommendation rate.

  13. Clarifying the use of aggregated exposures in multilevel models: self-included vs. self-excluded measures.

    Directory of Open Access Journals (Sweden)

    Etsuji Suzuki

    Full Text Available Multilevel analyses are ideally suited to assess the effects of ecological (higher level and individual (lower level exposure variables simultaneously. In applying such analyses to measures of ecologies in epidemiological studies, individual variables are usually aggregated into the higher level unit. Typically, the aggregated measure includes responses of every individual belonging to that group (i.e. it constitutes a self-included measure. More recently, researchers have developed an aggregate measure which excludes the response of the individual to whom the aggregate measure is linked (i.e. a self-excluded measure. In this study, we clarify the substantive and technical properties of these two measures when they are used as exposures in multilevel models.Although the differences between the two aggregated measures are mathematically subtle, distinguishing between them is important in terms of the specific scientific questions to be addressed. We then show how these measures can be used in two distinct types of multilevel models-self-included model and self-excluded model-and interpret the parameters in each model by imposing hypothetical interventions. The concept is tested on empirical data of workplace social capital and employees' systolic blood pressure.Researchers assume group-level interventions when using a self-included model, and individual-level interventions when using a self-excluded model. Analytical re-parameterizations of these two models highlight their differences in parameter interpretation. Cluster-mean centered self-included models enable researchers to decompose the collective effect into its within- and between-group components. The benefit of cluster-mean centering procedure is further discussed in terms of hypothetical interventions.When investigating the potential roles of aggregated variables, researchers should carefully explore which type of model-self-included or self-excluded-is suitable for a given situation

  14. Dual-lifetime referencing (DLR: a powerful method for on-line measurement of internal pH in carrier-bound immobilized biocatalysts

    Directory of Open Access Journals (Sweden)

    Boniello Caterina

    2012-03-01

    conditions of continuous measurement. During hydrolysis of cephalosporin C by the immobilizate in a stirred reactor with bulk pH maintained at 8.0, the intraparticle pH dropped initially by about 1 pH unit and gradually returned to the bulk pH, reflecting the depletion of substrate from solution. These results support measurement of intraparticle pH as a potential analytical processing tool for proton-forming/consuming biotransformations catalyzed by carrier-bound immobilized enzymes. Conclusions Fluorescein and Ru(dpp constitute a useful pair of luminophores in by DLR-based intraparticle pH monitoring. The pH range accessible by the chosen DLR system overlaps favorably with the pH ranges at which enzymes are optimally active and stable. DLR removes the restriction of working with static immobilized enzyme particles, enabling suspensions of particles to be characterized also. The pH gradient developed between particle and bulk liquid during reaction steady state is an important carrier selection parameter for enzyme immobilization and optimization of biocatalytic conversion processes. Determination of this parameter was rendered possible by the presented DLR method.

  15. Birth asphyxia measured by the pH value of the umbilical cord blood may predict an increased risk of attention deficit hyperactivity disorder.

    Science.gov (United States)

    Mikkelsen, Susanne Hvolgaard; Olsen, Jørn; Bech, Bodil Hammer; Wu, Chunsen; Liew, Zeyan; Gissler, Mika; Obel, Carsten; Arah, Onyebuchi

    2017-06-01

    Although birth asphyxia is a major risk factor for neonatal and childhood morbidity and mortality, it has not been investigated much in relation to attention deficit hyperactivity disorder (ADHD). We examined whether birth asphyxia measured by the pH of the blood in the umbilical artery cord was associated with childhood ADHD. A population-based cohort of 295 687 children born in Finland between 1991 and 2002 was followed until December 31, 2007. ADHD was identified by the International Classification of Diseases, 10th edition, as a diagnosis of hyperkinetic disorder. We examined the risk of ADHD with varying pH values using Cox regression, taking time trends into consideration. When compared to the reference group, a pH value below 7.10 was significantly associated with an increased risk of ADHD. The strongest risks were observed among children with a pH value value did not contribute much to the risk among children with an Apgar score of 0-3. Birth asphyxia, defined by low pH value, may predict an increased risk of ADHD in childhood. The association between the pH value and ADHD was homogenous when stratified by gestational age and the Apgar score. ©2017 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.

  16. Combination of On-line pH and Oxygen Transfer Rate Measurement in Shake Flasks by Fiber Optical Technique and Respiration Activity MOnitoring System (RAMOS

    Directory of Open Access Journals (Sweden)

    Jochen Büchs

    2007-12-01

    Full Text Available Shake flasks are commonly used for process development in biotechnologyindustry. For this purpose a lot of information is required from the growth conditions duringthe fermentation experiments. Therefore, Anderlei et al. developed the RAMOS technology[1, 2], which proviedes on-line oxygen and carbondioxide transfer rates in shake flasks.Besides oxygen consumption, the pH in the medium also plays an important role for thesuccessful cultivation of micro-organisms and for process development. For online pHmeasurement fiber optical methods based on fluorophores are available. Here a combinationof the on-line Oxygen Transfer Rate (OTR measurements in the RAMOS device with anon-line, fiber optical pH measurement is presented. To demonstrate the application of thecombined measurement techniques, Escherichia coli cultivations were performed and on-line pH measurements were compared with off-line samples. The combination of on-lineOTR and pH measurements gives a lot of information about the cultivation and, therefore, itis a powerful technique for monitoring shake flask experiments as well as for processdevelopment.

  17. Uso de membranas de Nafion para a construção de sensores ópticos para medidas de pH Use of Nafion® membranes for the construction of optical sensors for pH measurements

    Directory of Open Access Journals (Sweden)

    Silvia Cristina Lopes Pinheiro

    2005-10-01

    Full Text Available The behaviour of Nafion® polymeric membranes containing acid-base dyes, bromothymol blue (BB and methyl violet (MV, were studied aiming at constructing an optical sensor for pH measurement. BB revealed to be inadequate for developing sensing phases due to the electrostatic repulsion between negative groups of their molecules and the negative charge of the sulfonate group of the Nafion®, which causes leaching of the dye from the membrane. On the other hand, MV showed to be suitable due to the presence of positive groups in its structure. The membrane prepared from a methanolic solution whose Nafion®/dye molar ratio was 20 presented the best analytical properties, changing its color from green to violet in the pH range from 0.6 to 3.0. The membrane can be prepared with good reproducibility, presenting durability of ca. 6 months and response time of 22 s, making possible its use for pH determination in flow analysis systems.

  18. KEY COMPARISON: Final report on CCQM-K9.2: Subsequent key comparison on pH determination of phosphate buffer by Harned cell measurements

    Science.gov (United States)

    Spitzer, Petra; Giera, Janine; Fraga, Isabel C.; Tønnes Jakobsen, Pia; Jensen, Hans D.; Hyllested, Peter; Karpov, Oleg; Kutovoy, Viatcheslav; Nakamura, Susumu; Vospelova, Alena; Zvezdina, Valentina

    2008-01-01

    CCQM-K9.2 was performed supplementary to the key comparison CCQM-K9 on the pH determination of a phosphate buffer with nominal pH ~ 6.9 (at 25 °C). The sample composition was very similar in both comparisons. Only the source of the starting material used for sample preparation was different. The comparison was restricted to the use of the primary method for pH (Harned cell measurement) as defined in the IUPAC Recommendations [2]. The measurement temperatures were 15 °C, 25 °C, 37 °C. CCQM-K9.2, CCQM-K.9 and the first supplementary comparison CCQM-K9.1 [5] are activities of the Electrochemical Working Group (EAWG) of the CCQM. All three comparisons were coordinated by the PTB, Germany. The Danish Primary Laboratory (DPL) successfully took part in the CCQM-K9. Meanwhile the primary set-up for pH in Denmark moved from DPL affiliated to Radiometer Medical to DFM, Denmark. The subsequent comparison allows assessing the degree of equivalence for the measurement of pH at DFM after the move. Due to the interest of other laboratories in demonstrating their progress in pH measurements on the primary level the CCQM-K9.2 supplementary comparison was extended to other participants than DFM, namely NMIJ, VNIIFTRI, INMETRO and CMI. The reported quantity for CCQM-K9.2 was not the pH of the sample but the acidity function at zero chloride molality (see chapter 12). To calculate the pH value from the acidity function it is necessary to know the ionic strength of the sample buffer solution, which was undisclosed by the coordinator. With the exception of the Czech Metrology Institute, CMI, good agreement in the determined acidity function is found between the participants. The results reported by DFM and by PTB agree within their measurement uncertainty at all measurement temperatures. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report

  19. Continuous measurement of electrical characteristics in plants. 3. Shokubutsu seitai no denki tokusei sokuteiho. 3. ; Suikoeki pH chosei heno tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Sekiyama, T; Haniyu, H; Saiki, H

    1989-09-01

    Controlling pH of nutrient solution and keeping the other conditions unchanged, measurements of variation in electric potential difference between leaf and hypocotyl of a bush bean plant was performed for about seven days. Silver electrodes 0.3mm in diameter were glued on the surface of the plant using conductive paste prepared by dissolving gelatine in Ringel {prime} s solution. The results obtained are summarized as follws: first, when pH of the solution is suddenly increased or decreased, the potential of leave becomes high or low with respect to that of hypocotyl respectively; second, the variation in potential difference between them is affected by the rate at which pH of the solution is adjusted, although the total variation of pH is controlled to be the same, and in particular by mild adjustment (0.02 - 0.05pH/min) it is reduced to 1/2 - 1/4 of that produced by sudden change; third, abrupt change in pH of the solution cause to the plant the temporary suppression of its water absorption having a duration of 7 - 15 minutes. A short account is given of a non-contact type measurement of bioelectric potential performanced by making use of a Faraday {prime} s cage. 11 refs., 12 figs.

  20. Estimation of Hydrazine Decomposition on Measuring the High-Temperature pH in Hydrazine/ETA Solutions at 553 K

    International Nuclear Information System (INIS)

    Hwang, Jae Sik; Yeon, Jei Won; Yun, Myung Hee; Song, Kyu Seok; Lee, Sang Ill

    2010-01-01

    Hydrazine is one of the most excellent oxygen scavengers used in the secondary circuit of nuclear power plants. Furthermore, in some pants, the hydrazine is used as a source of hydrogen required to suppress radiolysis of the coolant water in the primary loop. When hydrazine was exposed in the high temperature and high pressure water, it can be decomposed into the various products such as NH 3 , N 2 , H 2 , and NO 3 ions. As the result, the pH of solution containing hydrazine in the condition of the high temperature and high pressure can be changed by those decomposed products. In the present work, we investigated the decomposition behavior of hydrazine in ETA (ethanol amine) solution. In addition, we measured the high temperature pH at 553 K on the various hydrazine/ETA solutions for confirming the applicability of the yttria stabilized zirconia (YSZ)- based pH electrode in secondary circuit of the nuclear power plants

  1. [Medical therapy of gastroesophageal reflux. Evaluation of the activity of clebopride by continuous intraluminal pH measurement].

    Science.gov (United States)

    Alvisi, V; Onofrio, W; Intrieri, L; D'Ambrosi, A

    1987-10-15

    Seven female and three male outpatients (mean age 45, range 37-54), suffering from gastroesophageal reflux underwent therapy with clebopride, a new selective antidopaminergic agent. Before and after treatment (1 mg b.i.d. for ten days) 24 h-continuous monitoring of esophageal pH was done. Clebopride significantly lowered the number and the extension of gastroesophageal acid refluxes.

  2. Round robin test for define an accurate protocol to measure the pore fluid pH of low-pH cementitious materials

    International Nuclear Information System (INIS)

    Alonso, M.C.; Garcia Calvo, J.L.; Pettersson, S.; Puigdomenech, I.; Cunado, M.A.; Vuorio, M.; Weber, H.; Ueda, H.; Naito, M.; Walker, C.; Takeshi, Y.; Cau Dit Coumes, C.

    2012-01-01

    The present research belongs to an international project where several of the main nuclear waste management agencies have been involved. The main objective is the development of agreed procedures or protocols for measuring the pH value using low-pH cementitious products (LopHC). The Pore Fluid Expression (PFE) has been identified as reference method and Ex-situ Leaching methods (ELS) with two variants (filtering and without filtering the obtained suspension) have been identified as routine methods. Both methodologies are based on the extraction of the pore solution of the concrete before pH determination. The protocols employed were based on a broad literature review and in fitting the more critical parameters, such as the sample size, the carbonation affection, the leaching of cement hydrates during the measurement, etc. Moreover, the routine methods were validated with respect to the pore fluid expression results. It appears that the repeatability of the 3 pH measurement protocols is very good and that the results obtained with both ESL procedures agree well with the results given by the PFE technique in the case of low-pH cementitious materials and are acceptable in the case of cementitious materials with high pore fluid pH values, in that case some corrections considering the Ca content of the solution may be needed

  3. PH Measurements of the Brain Using Phosphorus Magnetic Resonance Spectroscopy (31PMRS) in Healthy Men – Comparison of Two Analysis Methods

    International Nuclear Information System (INIS)

    Cichocka, Monika; Kozub, Justyna; Urbanik, Andrzej

    2015-01-01

    Intracellular pH provides information on homeostatic mechanisms in neurons and glial cells. The aim of this study was to define pH of the brain of male volunteers using phosphorus magnetic resonance spectroscopy ( 31 PMRS) and to compare two methods of calculating this value. In this study, 35 healthy, young, male volunteers (mean age: 25 years) were examined by 31 PMRS in 1.5 T MR system (Signa Excite, GE). The FID CSI (Free Induction Decay Chemical Shift Imaging) sequence was used with the following parameters: TR=4000 ms, FA=90°, NEX=2. Volume of interest (VOI) was selected depending on the size of the volunteers’ brain (11–14 cm 3 , mean 11.53 cm 3 ). Raw data were analyzed using SAGE (GE) software. Based on the chemical shift of peaks in the 31 PMRS spectrum, intracellular pH was calculated using two equations. In both methods the mean pH was slightly alkaline (7.07 and 7.08). Results were compared with a t-test. Significant difference (p<0.05) was found between these two methods. The 31 PMRS method enables non-invasive in vivo measurements of pH. The choice of the calculation method is crucial for computing this value. Comparing the results obtained by different teams can be done in a fully credible way only if the calculations were performed using the same formula

  4. Usefulness of saliva for measurement of 3,4-methylenedioxymethamphetamine and its metabolites: correlation with plasma drug concentrations and effect of salivary pH.

    Science.gov (United States)

    Navarro, M; Pichini, S; Farré, M; Ortuño, J; Roset, P N; Segura, J; de la Torre, R

    2001-10-01

    Saliva is an alternative biologic matrix for drugs-of-abuse testing that offers the advantages of noninvasive, rapid, and easy sampling. We studied the excretion profile of 3,4-methylenedioxymethamphetamine (MDMA) and its metabolites in both saliva and plasma, as well the effect of the drug on salivary pH. Saliva and plasma samples were obtained from eight healthy MDMA consumers after ingestion of a single 100-mg dose of the drug. Concentrations of MDMA and its main metabolites, 3,4-methylenedioxyamphetamine (MDA) and 4-hydroxy-3-methoxymethamphetamine (HMMA), in saliva and plasma were measured by gas chromatography-mass spectrometry. Apparent pharmacokinetic parameters for MDMA in saliva were estimated, and the saliva-to-plasma ratio at each time interval was calculated and correlated with salivary pH. MDMA, MDA, and HMMA were detected in saliva. Salivary concentrations of MDMA were 1728.9-6510.6 microg/L and peaked at 1.5 h after drug intake. This was followed by a progressive decrease, with a mean concentration of 126.2 microg/L at 24 h. The saliva-to-plasma ratio was 32.3-1.2, with a peak of 18.1 at 1.5 h after drug administration. Salivary pH seemed to be affected by MDMA administration; pH values decreased by 0.6 units (mean pH values of 6.9 and 6.8 at 1.5 and 4 h after drug administration vs predose pH of 7.4). Measurement of MDMA in saliva is a valuable alternative to determination of plasma drug concentrations in both clinical and toxicologic studies. On-site testing is also facilitated by noninvasive and rapid collection of salivary specimens.

  5. Sorption of Sr, Co and Zn on illite: Batch experiments and modelling including Co in-diffusion measurements on compacted samples

    Science.gov (United States)

    Montoya, V.; Baeyens, B.; Glaus, M. A.; Kupcik, T.; Marques Fernandes, M.; Van Laer, L.; Bruggeman, C.; Maes, N.; Schäfer, T.

    2018-02-01

    Experimental investigations on the uptake of divalent cations (Sr, Co and Zn) onto illite (Illite du Puy, Le-Puy-en-Velay, France) were carried out by three different international research groups (Institute for Nuclear Waste Disposal, KIT (Germany), Group Waste & Disposal, SCK-CEN, (Belgium) and Laboratory for Waste Management, PSI (Switzerland)) in the framework of the European FP7 CatClay project. The dependence of solid-liquid distribution ratios (Rd values) on pH at trace metal conditions (sorption edges) and on the metal ion concentration (sorption isotherms) was determined in dilute suspensions of homo-ionic Na-illite (Na-IdP) under controlled N2 atmosphere. The experimental results were modelled using the 2 Site Protolysis Non Electrostatic Surface Complexation and Cation Exchange (2SPNE SC/CE) sorption model. The sorption of Sr depends strongly on ionic strength, while a rather weak pH dependence is observed in a pH range between 3 and 11. The data were modelled with cation exchange reactions, taking into account competition with H, K, Ca, Mg and Al, and surface complexation on weak amphotheric edge sites at higher pH values. The sorption of Co on Na-IdP, however, is strongly pH dependent. Cation exchange on the planar sites and surface complexation on strong and weak amphoteric edge sites were used to describe the Co sorption data. Rd values for Co derived from in-diffusion measurements on compacted Na-IdP samples (bulk-dry density of 1700 kg m-3) between pH 5.0 and 9.0 are in good agreement with the batch sorption data. The equivalence of both approaches to measure sorption was thus confirmed for the present test system. In addition, the results highlight the importance of both major and minor surface species for the diffusive transport behaviour of strongly sorbing metal cations. While surface complexes at the edge sites determine largely the Rd value, the diffusive flux may be governed by those species bound to the planar sites, even at low fractional

  6. Detection of Micrococcus luteus biofilm formation in microfluidic environments by pH measurement using an ion-sensitive field-effect transistor.

    Science.gov (United States)

    Matsuura, Koji; Asano, Yuka; Yamada, Akira; Naruse, Keiji

    2013-02-18

    Biofilm formation in microfluidic channels is difficult to detect because sampling volumes are too small for conventional turbidity measurements. To detect biofilm formation, we used an ion-sensitive field-effect transistor (ISFET) measurement system to measure pH changes in small volumes of bacterial suspension. Cells of Micrococcus luteus (M. luteus) were cultured in polystyrene (PS) microtubes and polymethylmethacrylate (PMMA)-based microfluidic channels laminated with polyvinylidene chloride. In microtubes, concentrations of bacteria and pH in the suspension were analyzed by measuring turbidity and using an ISFET sensor, respectively. In microfluidic channels containing 20 μL of bacterial suspension, we measured pH changes using the ISFET sensor and monitored biofilm formation using a microscope. We detected acidification and alkalinization phases of M. luteus from the ISFET sensor signals in both microtubes and microfluidic channels. In the alkalinization phase, after 2 day culture, dense biofilm formation was observed at the bottom of the microfluidic channels. In this study, we used an ISFET sensor to detect biofilm formation in clinical and industrial microfluidic environments by detecting alkalinization of the culture medium. 

  7. Detection of Micrococcus Luteus Biofilm Formation in Microfluidic Environments by pH Measurement Using an Ion-Sensitive Field-Effect Transistor

    Directory of Open Access Journals (Sweden)

    Keiji Naruse

    2013-02-01

    Full Text Available Biofilm formation in microfluidic channels is difficult to detect because sampling volumes are too small for conventional turbidity measurements. To detect biofilm formation, we used an ion-sensitive field-effect transistor (ISFET measurement system to measure pH changes in small volumes of bacterial suspension. Cells of Micrococcus luteus (M. luteus were cultured in polystyrene (PS microtubes and polymethylmethacrylate (PMMA-based microfluidic channels laminated with polyvinylidene chloride. In microtubes, concentrations of bacteria and pH in the suspension were analyzed by measuring turbidity and using an ISFET sensor, respectively. In microfluidic channels containing 20 μL of bacterial suspension, we measured pH changes using the ISFET sensor and monitored biofilm formation using a microscope. We detected acidification and alkalinization phases of M. luteus from the ISFET sensor signals in both microtubes and microfluidic channels. In the alkalinization phase, after 2 day culture, dense biofilm formation was observed at the bottom of the microfluidic channels. In this study, we used an ISFET sensor to detect biofilm formation in clinical and industrial microfluidic environments by detecting alkalinization of the culture medium.

  8. Sensitivities of Key Parameters in the Preparation of Silver/Silver Chloride Electrodes Used in Harned Cell Measurements of pH

    Directory of Open Access Journals (Sweden)

    Richard J. C. Brown

    2011-08-01

    Full Text Available A questionnaire was completed by fourteen world leading national metrology institutes to study the influence of several variables in the preparation of Ag/AgCl electrodes on the accuracy of Harned cell measurements of pH. The performance of each institute in the last decade has been assessed based on their results in eight key comparisons, organized by the Bureau International des Poids et Measures Consultative Committee for Amount of Substance, involving the measurement of pH of phosphate, phthalate, carbonate, borate and tetroxalate buffer solutions. The performance of each laboratory has been correlated to the results of the questionnaire to determine the critical parameters in the preparation of Ag/AgCl electrodes and their sensitivities with respect to the accuracy of pH measurement. This study reveals that the parameters most closely correlated to performance in comparisons are area of electrode wire exposed to the electrolyte, diameter and porosity of the Ag sphere prior to anodisation, amount of Ag converted to AgCl during anodisation, stability times employed for electrodes to reach equilibrium in solution prior to measurement, electrode rejection criteria employed and purity of reagents.

  9. 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.

  10. Evaluation and study of advanced optical contamination, deposition, measurement, and removal techniques. [including computer programs and ultraviolet reflection analysis

    Science.gov (United States)

    Linford, R. M. F.; Allen, T. H.; Dillow, C. F.

    1975-01-01

    A program is described to design, fabricate and install an experimental work chamber assembly (WCA) to provide a wide range of experimental capability. The WCA incorporates several techniques for studying the kinetics of contaminant films and their effect on optical surfaces. It incorporates the capability for depositing both optical and contaminant films on temperature-controlled samples, and for in-situ measurements of the vacuum ultraviolet reflectance. Ellipsometer optics are mounted on the chamber for film thickness determinations, and other features include access ports for radiation sources and instrumentation. Several supporting studies were conducted to define specific chamber requirements, to determine the sensitivity of the measurement techniques to be incorporated in the chamber, and to establish procedures for handling samples prior to their installation in the chamber. A bibliography and literature survey of contamination-related articles is included.

  11. Reliability of Measured Data for pH Sensor Arrays with Fault Diagnosis and Data Fusion Based on LabVIEW

    OpenAIRE

    Liao, Yi-Hung; Chou, Jung-Chuan; Lin, Chin-Yi

    2013-01-01

    Fault diagnosis (FD) and data fusion (DF) technologies implemented in the LabVIEW program were used for a ruthenium dioxide pH sensor array. The purpose of the fault diagnosis and data fusion technologies is to increase the reliability of measured data. Data fusion is a very useful statistical method used for sensor arrays in many fields. Fault diagnosis is used to avoid sensor faults and to measure errors in the electrochemical measurement system, therefore, in this study, we use fault diagn...

  12. Reference value standards and primary standards for pH measurements in D2O and aqueous-organic solvent mixtures: new accessions and assessments

    International Nuclear Information System (INIS)

    Mussini, P.R.; Mussini, T.; Rondinini, S.

    1997-01-01

    Recommended Reference Value Standards based on the potassium hydro-genphthalate buffer at various temperatures are reported for pH measurements in various binary solvent mixtures of water with eight organic solvents: methanol, ethanol, 2-propanol, 1,2-ethanediol, 2-methoxyethanol (''methylcellosolve''), acetonitrile, 1,4-dioxane, and dimethyl sulfoxide, together with Reference Value Standard based on the potassium deuterium phthalate buffer for pD measurements in D 2 O. In addition are reported Primary Standards for pH based on numerous buffers in various binary solvent mixtures of water with methanol, ethanol, and dimethyl sulfoxide, together with Primary Standards for pD in D 2 O based on the citrate, phosphate and carbonate buffers. (author)

  13. Reliability of measured data for pH sensor arrays with fault diagnosis and data fusion based on LabVIEW.

    Science.gov (United States)

    Liao, Yi-Hung; Chou, Jung-Chuan; Lin, Chin-Yi

    2013-12-13

    Fault diagnosis (FD) and data fusion (DF) technologies implemented in the LabVIEW program were used for a ruthenium dioxide pH sensor array. The purpose of the fault diagnosis and data fusion technologies is to increase the reliability of measured data. Data fusion is a very useful statistical method used for sensor arrays in many fields. Fault diagnosis is used to avoid sensor faults and to measure errors in the electrochemical measurement system, therefore, in this study, we use fault diagnosis to remove any faulty sensors in advance, and then proceed with data fusion in the sensor array. The average, self-adaptive and coefficient of variance data fusion methods are used in this study. The pH electrode is fabricated with ruthenium dioxide (RuO2) sensing membrane using a sputtering system to deposit it onto a silicon substrate, and eight RuO2 pH electrodes are fabricated to form a sensor array for this study.

  14. Reliability of Measured Data for pH Sensor Arrays with Fault Diagnosis and Data Fusion Based on LabVIEW

    Directory of Open Access Journals (Sweden)

    Yi-Hung Liao

    2013-12-01

    Full Text Available Fault diagnosis (FD and data fusion (DF technologies implemented in the LabVIEW program were used for a ruthenium dioxide pH sensor array. The purpose of the fault diagnosis and data fusion technologies is to increase the reliability of measured data. Data fusion is a very useful statistical method used for sensor arrays in many fields. Fault diagnosis is used to avoid sensor faults and to measure errors in the electrochemical measurement system, therefore, in this study, we use fault diagnosis to remove any faulty sensors in advance, and then proceed with data fusion in the sensor array. The average, self-adaptive and coefficient of variance data fusion methods are used in this study. The pH electrode is fabricated with ruthenium dioxide (RuO2 sensing membrane using a sputtering system to deposit it onto a silicon substrate, and eight RuO2 pH electrodes are fabricated to form a sensor array for this study.

  15. New method of measuring lichen respiration: response of selected species to temperature, pH and sulphur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Baddeley, M S; Ferry, B W; Finegan, E J

    1971-01-01

    The respiration of selected lichens and their response to temperature, pH and sulphur dioxide concentration were investigated in aqueous solution using an oxygen electrode. Respiration rates increased to a maximum at 40/sup 0/ C although some individual species showed variations from this general pattern. The optimal pH for respiration was found to be 4.2 except in Hypogymnia physodes (3.2) and Ramalina fastigiata (5.2). Sulfur dioxide at concentrations similar to those likely to be encountered in heavily polluted areas in nature had marked inhibitory effects of the respiration rate of all species investigated but as these variations did not entirely correspond to the tolerances of the species in the field some other factors must also be involved in the sensitivity of lichens to sulphur dioxide pollution. The advantages of using an oxygen electrode rather than manometric or other techniques in studies on the respiration rate of lichens are discussed. 29 references, 3 figures, 2 tables.

  16. Comprehensive analysis of proteins of pH fractionated samples using monolithic LC/MS/MS, intact MW measurement and MALDI-QIT-TOF MS

    Science.gov (United States)

    Yoo, Chul; Patwa, Tasneem H.; Kreunin, Paweena; Miller, Fred R.; Huber, Christian G.; Nesvizhskii, Alexey I.; Lubman, David M.

    2012-01-01

    A comprehensive platform that integrates information from the protein and peptide levels by combining various MS techniques has been employed for the analysis of proteins in fully malignant human breast cancer cells. The cell lysates were subjected to chromatofocusing fractionation, followed by tryptic digestion of pH fractions for on-line monolithic RP-HPLC interfaced with linear ion trap MS analysis for rapid protein identification. This unique approach of direct analysis of pH fractions resulted in the identification of large numbers of proteins from several selected pH fractions, in which approximately 1.5 μg of each of the pH fraction digests was consumed for an analysis time of ca 50 min. In order to combine valuable information retained at the protein level with the protein identifications obtained from the peptide level information, the same pH fraction was analyzed using nonporous (NPS)-RP-HPLC/ESI-TOF MS to obtain intact protein MW measurements. In order to further validate the protein identification procedures from the fraction digest analysis, NPS-RP-HPLC separation was performed for off-line protein collection to closely examine each protein using MALDI-TOF MS and MALDI-quadrupole ion trap (QIT)-TOF MS, and excellent agreement of protein identifications was consistently observed. It was also observed that the comparison to intact MW and other MS information was particularly useful for analyzing proteins whose identifications were suggested by one sequenced peptide from fraction digest analysis. PMID:17206599

  17. Variability of O2, H2S, and pH in intertidal sediments measured on a highly resolved spatial and temporal scale

    Science.gov (United States)

    Walpersdorf, E.; Werner, U.; Bird, P.; de Beer, D.

    2003-04-01

    We investigated the variability of O_2, pH, and H_2S in intertidal sediments to assess the time- and spatial scales of changes in environmental conditions and their effects on bacterial activities. Measurements were performed over the tidal cycle and at different seasons by the use of microsensors attached to an autonomous in-situ measuring device. This study was carried out at a sand- and a mixed flat in the backbarrier area of Spiekeroog (Germany) within the frame of the DFG research group "Biogeochemistry of the Wadden Sea". Results showed that O_2 variability was not pronounced in the coastal mixed flat, where only extreme weather conditions could increase O_2 penetration. In contrast, strong dynamics in O_2 availability, pH and maximum penetration depths of several cm were found at the sandflat. In these highly permeable sediments, we directly observed tidal pumping: at high tide O_2-rich water was forced into the plate and at low tide anoxic porewater drained off the sediment. From the lower part of the plate where organic rich clayey layers were embedded in the sediment anoxic water containing H_2S leaked out during low tide. Thus advective processes, driven by the tidal pump, waves and currents, control O_2 penetration and depth distribution of H_2S and pH. The effects of the resulting porewater exchange on mineralization rates and microbial activities will be discussed.

  18. In-situ pH measurements and sample analyses in glass-iron-clay systems at 90 deg. C and 150 deg. C

    International Nuclear Information System (INIS)

    Rozsypal, Christophe; Mosser-Ruck, Regine; Truche, Laurent; Pignatelli, Isabella; Randi, Aurelien; Bartier, Daniele; Cathelineau, Michel; Michau, Nicolas

    2012-01-01

    Document available in extended abstract form only. The long term repository of long life and high activity radioactive waste consists in the burial of steel overpacks of vitrified waste in a clay-stone. As the natural interstitial fluid of the clay-stone is a potential corrosion enhancer for the containers, the viability of the repository requires previous data acquisition on the interactions between clays, water, metallic iron, and glass. A set of experiments have been performed in autoclaves at 90 deg. C (thermal peak of the site) in order to follow the pH evolution and to characterize fluids with time and solids at the end of the experiments. Another set of experiments at 150 deg. C have also been carried out in order to increase the rates of the involved chemical reactions and mineralogical transformations. The objectives of those two sets of experiments were to measure the in-situ pH, to study how it was influenced by various parameters, such as the presence of glass and/or iron, to estimate the increase of the CO 2 and H 2 pressures, and to analyze gas and liquids taken in the course or at the end of experiments and solids recovered at the end of the experiments. The initial aqueous solution simulating the natural interstitial fluid was made of 22 mM of sodium, 4 mM of calcium, 29.75 mM of chloride, and 0.25 mM of bromide as a tracer. The initial solution/clay mass ratio was 10 for all the experiments, the metallic iron/clay or glass/clay mass ratios were 0.1 or 0. The list of the experiments and their characteristics is given in Table (1). The first results concern the evolution of the in-situ pH during the A90pH experiment and are reported on Figure (1). The measurements started after a 48 hours stabilization time of the pH probe. The pH seemed to tend reaching a plateau after several weeks. (authors)

  19. Possibilities of new materials surface sensibility express determination based on ZnSe-CdS system by pH isoelectric state measurements of the surface state

    Science.gov (United States)

    Kirovskaya, I. A.; Mironova, E. V.; Ushakov, O. V.; Nor, P. E.; Yureva, A. V.; Matyash, Yu I.

    2018-01-01

    A method for determining the hydrogen index of the surfaces isoelectric state (pHiso) at various gases pressures -possible components of the surrounding and technological media has been developed. With its use, changes in pH of binary and more complex semiconductors-components of the new system-ZnSe-CdS under the influence of nitrogen dioxide-have been found. The limiting sensitivity of surfaces - minimum PNO2, causing a change in pH has been estimated. The most active components of ZnSe-CdS system, recommended as materials for measuring cells of NO2, have been revealed. The relationship between the changing patterns with the composition of surface (acid-base) and bulk (in particular, theoretical calculated crystal density) properties has been established, allowing to find the most effective materials for sensor technology and for semiconductor analysis.

  20. Lung disease severity in idiopathic pulmonary fibrosis is more strongly associated with impedance measures of bolus reflux than pH parameters of acid reflux alone.

    Science.gov (United States)

    Gavini, S; Borges, L F; Finn, R T; Lo, W-K; Goldberg, H J; Burakoff, R; Feldman, N; Chan, W W

    2017-05-01

    Gastroesophageal reflux (GER) has been associated with idiopathic pulmonary fibrosis (IPF). Pathogenesis may be related to chronic micro-aspiration. We aimed to assess objective measures of GER on multichannel intraluminal impedance and pH study (MII-pH) and their relationship with pulmonary function testing (PFT) results, and to compare the performance of pH/acid reflux parameters vs corresponding MII/bolus parameters in predicting pulmonary dysfunction in IPF. This was a retrospective cohort study of IPF patients undergoing prelung transplant evaluation with MII-pH off acid suppression, and having received PFT within 3 months. Patients with prior fundoplication were excluded. Severe pulmonary dysfunction was defined using diffusion capacity of the lung for carbon monoxide (DLCO) ≤40%. Six pH/acid reflux parameters with corresponding MII/bolus reflux measures were specified a priori. Multivariate analyses were applied using forward stepwise logistic regression. Predictive value of each parameter for severe pulmonary dysfunction was calculated by area-under-the-receiver-operating-characteristic-curve or c-statistic. Forty-five subjects (67% M, age 59, 15 mild-moderate vs 30 severe) met criteria for inclusion. Patient demographics and clinical characteristics were similar between pulmonary dysfunction groups. Abnormal total reflux episodes and prolonged bolus clearance time were significantly associated with pulmonary dysfunction severity on univariate and multivariate analyses. No pH parameters were significant. The c-statistic of each pH parameter was lower than its MII counterpart in predicting pulmonary dysfunction. MII/bolus reflux, but not pH/acid reflux, was associated with pulmonary dysfunction in prelung transplant patients with IPF. MII-pH may be more valuable than pH testing alone in characterizing GER in IPF. © 2016 John Wiley & Sons Ltd.

  1. Technical standards and guidelines: prenatal screening for Down syndrome that includes first-trimester biochemistry and/or ultrasound measurements.

    Science.gov (United States)

    Palomaki, Glenn E; Lee, Jo Ellen S; Canick, Jacob A; McDowell, Geraldine A; Donnenfeld, Alan E

    2009-09-01

    This statement is intended to augment the current general ACMG Standards and Guidelines for Clinical Genetics Laboratories and to address guidelines specific to first-trimester screening for Down syndrome. The aim is to provide the laboratory the necessary information to ensure accurate and reliable Down syndrome screening results given a screening protocol (e.g., combined first trimester and integrated testing). Information about various test combinations and their expected performance are provided, but other issues such as availability of reagents, patient interest in early test results, access to open neural tube defect screening, and availability of chorionic villus sampling are all contextual factors in deciding which screening protocol(s) will be selected by individual health care providers. Individual laboratories are responsible for meeting the quality assurance standards described by the Clinical Laboratory Improvement Act, the College of American Pathologists, and other regulatory agencies, with respect to appropriate sample documentation, assay validation, general proficiency, and quality control measures. These guidelines address first-trimester screening that includes ultrasound measurement and interpretation of nuchal translucency thickness and protocols that combine markers from both the first and second trimesters. Laboratories can use their professional judgment to make modification or additions.

  2. Technological study about a disposal measures of low-level radioactive waste including uranium and long-half-life radionuclides

    International Nuclear Information System (INIS)

    Sugaya, Toshikatsu; Nakatani, Takayoshi; Sakai, Akihiro; Sakamoto, Yoshiaki; Sasaki, Toshihisa; Nakamura, Yasuo

    2017-02-01

    Japan Atomic Energy Agency (JAEA) performed the technical studies contributed for the disposal measures of uranium-bearing waste with low concentration and intermediate depth disposal-based waste occurring from the process of the nuclear fuel cycle. (1) Study of the trench disposal of uranium-bearing waste. As a part of the study of disposal measures of the uranium-bearing waste, we carried out the safety assessment (exposure dose assessment) and derived the upper limit of radioactivity concentration of uranium which was allowed to be included in radioactive waste for trench disposal. (2) Preliminary study for the expansion of material applied to clearance in uranium-bearing waste. Currently, the clearance level of uranium handling facilities was derived from the radioactivity concentration of uranium corresponding to dose criterion about the exposure pathways of the reuse and recycle of metal. Therefore, we preliminarily evaluated whether metal and concrete were able to be applied to clearance by the method of the undergrounding disposal. (3) Study of the concentration limitation scenarios for the intermediate depth disposal-based waste. We carried out dose assessment of intermediate depth disposal of radioactive waste generated from JAEA about radioactive concentration limitation scenarios of which the concept was shown by the study team in Nuclear Regulation Authority. Based on the results, we discussed whether the waste was applied to radioactive waste conforming to concept of intermediate depth disposal. (author)

  3. Mathematical modeling of HIV prevention measures including pre-exposure prophylaxis on HIV incidence in South Korea.

    Science.gov (United States)

    Kim, Sun Bean; Yoon, Myoungho; Ku, Nam Su; Kim, Min Hyung; Song, Je Eun; Ahn, Jin Young; Jeong, Su Jin; Kim, Changsoo; Kwon, Hee-Dae; Lee, Jeehyun; Smith, Davey M; Choi, Jun Yong

    2014-01-01

    Multiple prevention measures have the possibility of impacting HIV incidence in South Korea, including early diagnosis, early treatment, and pre-exposure prophylaxis (PrEP). We investigated how each of these interventions could impact the local HIV epidemic, especially among men who have sex with men (MSM), who have become the major risk group in South Korea. A mathematical model was used to estimate the effects of each these interventions on the HIV epidemic in South Korea over the next 40 years, as compared to the current situation. We constructed a mathematical model of HIV infection among MSM in South Korea, dividing the MSM population into seven groups, and simulated the effects of early antiretroviral therapy (ART), early diagnosis, PrEP, and combination interventions on the incidence and prevalence of HIV infection, as compared to the current situation that would be expected without any new prevention measures. Overall, the model suggested that the most effective prevention measure would be PrEP. Even though PrEP effectiveness could be lessened by increased unsafe sex behavior, PrEP use was still more beneficial than the current situation. In the model, early diagnosis of HIV infection was also effectively decreased HIV incidence. However, early ART did not show considerable effectiveness. As expected, it would be most effective if all interventions (PrEP, early diagnosis and early treatment) were implemented together. This model suggests that PrEP and early diagnosis could be a very effective way to reduce HIV incidence in South Korea among MSM.

  4. Measurement of Rapid Amiloride-Dependent pH Changes at the Cell Surface Using a Proton-Sensitive Field-Effect Transistor.

    Science.gov (United States)

    Schaffhauser, Daniel; Fine, Michael; Tabata, Miyuki; Goda, Tatsuro; Miyahara, Yuji

    2016-03-30

    We present a novel method for the rapid measurement of pH fluxes at close proximity to the surface of the plasma membrane in mammalian cells using an ion-sensitive field-effect transistor (ISFET). In conjuction with an efficient continuous superfusion system, the ISFET sensor was capable of recording rapid changes in pH at the cells' surface induced by intervals of ammonia loading and unloading, even when using highly buffered solutions. Furthermore, the system was able to isolate physiologically relevant signals by not only detecting the transients caused by ammonia loading and unloading, but display steady-state signals as would be expected by a proton transport-mediated influence on the extracellular proton-gradient. Proof of concept was demonstrated through the use of 5-(N-ethyl-N-isopropyl)amiloride (EIPA), a small molecule inhibitor of sodium/hydrogen exchangers (NHE). As the primary transporter responsible for proton balance during cellular regulation of pH, non-electrogenic NHE transport is notoriously difficult to detect with traditional methods. Using the NHE positive cell lines, Chinese hamster ovary (CHO) cells and NHE3-reconstituted mouse skin fibroblasts (MSF), the sensor exhibited a significant response to EIPA inhibition, whereas NHE-deficient MSF cells were unaffected by application of the inhibitor.

  5. Effect of Na, Ca and pH on simultaneous uptake of Cd, Cu, Ni, Pb, and Zn in the water flea Daphnia magna measured using stable isotopes

    International Nuclear Information System (INIS)

    Komjarova, I.; Blust, R.

    2009-01-01

    The present study investigates the effects of Na + , Ca 2+ and pH on the kinetics of Cd, Cu, Ni, Pb, and Zn uptake in Daphnia magna at low exposure concentrations measured using a stable isotope technique. Using experimental data the uptake rate constants were calculated for each metal individually on the basis of total metal concentrations. The copper uptake was not significantly affected by variations in chemical composition of the test medium. Calcium had a suppressing effect on the uptake of Cd, Ni, Pb and Zn. Specifically, Cd and Ni uptake rate constants decreased with increases in calcium concentrations from 0.1 to 2.5 mM. The uptake of Zn and Pb was significantly suppressed only at 2.5 mM Ca. The effect of sodium was less clear. There was no effect of varying sodium concentrations on the Ni uptake rate constants. Cd and Pb showed an increase in uptake rate constants at elevated sodium concentrations (2-8 mM Na + for Cd and 8 mM Na + for Pb). A bell-shaped response on increasing Na + concentrations was observed for Zn with a maximum value of uptake rate constant at the middle value (2 mM Na + ). Variation in pH of the medium affected Cd, Ni and Zn uptake processes. When Daphnia were exposed to acidic conditions (pH 6), the Cd and Ni uptake rate constants were the highest, while similarly low values were observed at neutral and basic conditions. In contrast, the uptake rates of Zn were linearly increasing with increasing pH of the medium.

  6. Birth asphyxia measured by the pH value of the umbilical cord blood may predict an increased risk of attention deficit hyperactivity disorder

    DEFF Research Database (Denmark)

    Mikkelsen, Susanne Hvolgaard; Olsen, Jørn; Bech, Bodil Hammer

    2017-01-01

    AIM: Although birth asphyxia is a major risk factor for neonatal and childhood morbidity and mortality, it has not been investigated much in relation to attention deficit hyperactivity disorder (ADHD). We examined whether birth asphyxia measured by the pH of the blood in the umbilical artery cord...... was associated with childhood ADHD. METHOD: A population-based cohort of 295 687 children born in Finland between 1991 and 2002 was followed until December 31, 2007. ADHD was identified by the International Classification of Diseases, 10th edition, as a diagnosis of hyperkinetic disorder. We examined the risk...

  7. 76 FR 81004 - Imposition of Nonproliferation Measures Against Foreign Persons, Including a Ban on U.S...

    Science.gov (United States)

    2011-12-27

    ... DEPARTMENT OF STATE [Public Notice: 7741] Imposition of Nonproliferation Measures Against Foreign... Nonproliferation, Department of State. ACTION: Notice. SUMMARY: A determination has been made that a number of foreign entities and one foreign person have engaged in activities that warrant the imposition of measures...

  8. Bias and other limitations affect measures of journals in integrative and complementary medicineKa-wai Fan, PhD.

    Science.gov (United States)

    Fan, Ka-wai

    2015-07-01

    Publishing articles in a prestigious journal is a golden rule for university professors and researchers nowadays. Impact factor, journal rank, and citation count, included in Science Citation Index managed by Thomson Reuters Web of Science, are the most important indicators for evaluating the quality of academic journals. By listing the journals encompassed in the "Integrative and Complementary Medicine" category of Science Citation Index from 2003 to 2013, this paper examines the publication trends of journals in the category. The examination includes number, country of origin, ranking, and languages of journals. Moreover, newly listed or removed journals in the category, journal publishers, and open access strategies are examined. It is concluded that the role of journal publisher should not be undermined in the "Integrative and Complementary Medicine" category.

  9. 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.

  10. Inertial acceleration as a measure of linear vection: An alternative to magnitude estimation. Ph.D. Thesis

    Science.gov (United States)

    Carpenter-Smith, Theodore R.; Futamura, Robert G.; Parker, Donald E.

    1995-01-01

    The present study focused on the development of a procedure to assess perceived self-motion induced by visual surround motion - vection. Using an apparatus that permitted independent control of visual and inertial stimuli, prone observers were translated along their head x-axis (fore/aft). The observers' task was to report the direction of self-motion during passive forward and backward translations of their bodies coupled with exposure to various visual surround conditions. The proportion of 'forward' responses was used to calculate each observer's point of subjective equality (PSE) for each surround condition. The results showed that the moving visual stimulus produced a significant shift in the PSE when data from the moving surround condition were compared with the stationary surround and no-vision condition. Further, the results indicated that vection increased monotonically with surround velocities between 4 and 40/s. It was concluded that linear vection can be measured in terms of changes in the amplitude of whole-body inertial acceleration required to elicit equivalent numbers of 'forward' and 'backward' self-motion reports.

  11. 49 CFR 23.25 - What measures must recipients include in their ACDBE programs to ensure nondiscriminatory...

    Science.gov (United States)

    2010-10-01

    ... Transportation Office of the Secretary of Transportation PARTICIPATION OF DISADVANTAGED BUSINESS ENTERPRISE IN... race-neutral measures you can implement: (1) Locating and identifying ACDBEs and other small businesses...) Ensuring that competitors for concession opportunities are informed during pre-solicitation meetings about...

  12. The Accuracy of Parameter Estimation in System Identification of Noisy Aircraft Load Measurement. Ph.D. Thesis

    Science.gov (United States)

    Kong, Jeffrey

    1994-01-01

    This thesis focuses on the subject of the accuracy of parameter estimation and system identification techniques. Motivated by a complicated load measurement from NASA Dryden Flight Research Center, advanced system identification techniques are needed. The objective of this problem is to accurately predict the load experienced by the aircraft wing structure during flight determined from a set of calibrated load and gage response relationship. We can then model the problem as a black box input-output system identification from which the system parameter has to be estimated. Traditional LS (Least Square) techniques and the issues of noisy data and model accuracy are addressed. A statistical bound reflecting the change in residual is derived in order to understand the effects of the perturbations on the data. Due to the intrinsic nature of the LS problem, LS solution faces the dilemma of the trade off between model accuracy and noise sensitivity. A method of conflicting performance indices is presented, thus allowing us to improve the noise sensitivity while at the same time configuring the degredation of the model accuracy. SVD techniques for data reduction are studied and the equivalence of the Correspondence Analysis (CA) and Total Least Squares Criteria are proved. We also looked at nonlinear LS problems with NASA F-111 data set as an example. Conventional methods are neither easily applicable nor suitable for the specific load problem since the exact model of the system is unknown. Neural Network (NN) does not require prior information on the model of the system. This robustness motivated us to apply the NN techniques on our load problem. Simulation results for the NN methods used in both the single load and the 'warning signal' problems are both useful and encouraging. The performance of the NN (for single load estimate) is better than the LS approach, whereas no conventional approach was tried for the 'warning signals' problems. The NN design methodology is also

  13. Response of Listeria monocytogenes to disinfection stress at the single-cell and population levels as monitored by intracellular pH measurements and viable-cell counts

    DEFF Research Database (Denmark)

    Kastbjerg, Vicky Gaedt; Nielsen, Dennis S.; Arneborg, Nils

    2009-01-01

    of the bacterium. In situ analyses of Listeria monocytogenes single cells were performed during exposure to different concentrations of the disinfectant Incimaxx DES to study a possible population subdivision. Bacterial survival was quantified with plate counting and disinfection stress at the single-cell level...... by measuring intracellular pH (pHi) over time by fluorescence ratio imaging microscopy. pHi values were initially 7 to 7.5 and decreased in both attached and planktonic L. monocytogenes cells during exposure to sublethal and lethal concentrations of Incimaxx DES. The response of the bacterial population...... was homogenous; hence, subpopulations were not detected. However, pregrowth with NaCl protected the planktonic bacterial cells during disinfection with Incimaxx (0.0015%) since pHi was higher (6 to 6.5) for the bacterial population pregrown with NaCl than for cells grown without NaCl (pHi 5 to 5.5) (P

  14. The FARE: A new way to express FAlls Risk among older persons including physical activity as a measure of Exposure

    NARCIS (Netherlands)

    Wijlhuizen, G.J.; Chorus, A.M.J.; Hopman-Rock, M.

    2010-01-01

    Background: Common expressions of falls risk do not include exposure to hazards. We compared two expressions: the commonly used population incidence (fallers per 1000 person-years) and the FARE (FAlls Risk by Exposure): the number of fallers per 1000 physically active person-days. Methods:

  15. The FARE: a new way to express FAlls Risk among older persons including physical activity as a measure of exposure

    NARCIS (Netherlands)

    Wijlhuizen, G.J.; Chorus, A.M.J.; Hopman-Rock, M.

    2010-01-01

    Background: Common expressions of falls risk do not include exposure to hazards. We compared two expressions: the commonly used population incidence (fallers per 1000 person-years) and the FARE (FAlls Risk by Exposure): the number of fallers per 1000 physically active person-days. Methods:

  16. Stability enhancement of an atomic force microscope for long-term force measurement including cantilever modification for whole cell deformation

    Science.gov (United States)

    Weafer, P. P.; McGarry, J. P.; van Es, M. H.; Kilpatrick, J. I.; Ronan, W.; Nolan, D. R.; Jarvis, S. P.

    2012-09-01

    Atomic force microscopy (AFM) is widely used in the study of both morphology and mechanical properties of living cells under physiologically relevant conditions. However, quantitative experiments on timescales of minutes to hours are generally limited by thermal drift in the instrument, particularly in the vertical (z) direction. In addition, we demonstrate the necessity to remove all air-liquid interfaces within the system for measurements in liquid environments, which may otherwise result in perturbations in the measured deflection. These effects severely limit the use of AFM as a practical tool for the study of long-term cell behavior, where precise knowledge of the tip-sample distance is a crucial requirement. Here we present a readily implementable, cost effective method of minimizing z-drift and liquid instabilities by utilizing active temperature control combined with a customized fluid cell system. Long-term whole cell mechanical measurements were performed using this stabilized AFM by attaching a large sphere to a cantilever in order to approximate a parallel plate system. An extensive examination of the effects of sphere attachment on AFM data is presented. Profiling of cantilever bending during substrate indentation revealed that the optical lever assumption of free ended cantilevering is inappropriate when sphere constraining occurs, which applies an additional torque to the cantilevers "free" end. Here we present the steps required to accurately determine force-indentation measurements for such a scenario. Combining these readily implementable modifications, we demonstrate the ability to investigate long-term whole cell mechanics by performing strain controlled cyclic deformation of single osteoblasts.

  17. 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)

  18. Evaluation, including effects of storage and repeated freezing and thawing, of a method for measurement of urinary creatinine

    DEFF Research Database (Denmark)

    Garde, A H; Hansen, Åse Marie; Kristiansen, J

    2003-01-01

    The aims of this study were to elucidate to what extent storage and repeated freezing and thawing influenced the concentration of creatinine in urine samples and to evaluate the method for determination of creatinine in urine. The creatinine method was based on the well-known Jaffe's reaction...... and measured on a COBAS Mira autoanalyser from Roche. The main findings were that samples for analysis of creatinine should be kept at a temperature of -20 degrees C or lower and frozen and thawed only once. The limit of detection, determined as 3 x SD of 20 determinations of a sample at a low concentration (6...

  19. Quality assessment and consistency check of measured nuclear data up to 20 MeV including the range of resonances

    International Nuclear Information System (INIS)

    Boedy, Z.T.

    1984-09-01

    This is the final report of a research contract with the IAEA. The object is the compilation and evaluation of all the data on (n,t) and (n,3He) reactions cross-sections, respectively. The main results of the research are given (some discrepancies in the experimental data; analytic formulas for an empirical description of the data, separately for the even and odd nuclei with z>20; methods to extrapolate to energies where measurements are missing; mass regions where data are needed), and publications by the authors with the detailed results are quoted

  20. Validation of Measured Damping Trends for Flight-Like Vehicle Panel/Equipment including a Range of Cable Harness Assemblies

    Science.gov (United States)

    Smith, Andrew M.; Davis, R. Benjamin; LaVerde, Bruce T.; Fulcher, Clay W.; Jones, Douglas C.; Waldon, James M.; Craigmyle, Benjamin B.

    2012-01-01

    This validation study examines the effect on vibroacoustic response resulting from the installation of cable bundles on a curved orthogrid panel. Of interest is the level of damping provided by the installation of the cable bundles and whether this damping could be potentially leveraged in launch vehicle design. The results of this test are compared with baseline acoustic response tests without cables. Damping estimates from the measured response data are made using a new software tool that leverages a finite element model of the panel in conjunction with advanced optimization techniques. While the full test series is not yet complete, the first configuration of cable bundles that was assessed effectively increased the viscous critical damping fraction of the system by as much as 0.02 in certain frequency ranges.

  1. Alterações da motilidade antroduodenal e do pH gástrico após ressecção gástrica parcial incluindo a área correspondente ao marca-passo do estômago de cães Antroduodenal motility and pH changes after partial gastrectomy including the pacemaker region of the dog's stomach

    Directory of Open Access Journals (Sweden)

    Paulo Afonso Nunes Nassif

    2003-06-01

    motility in dogs. METHODS: The study was designed in three steps and performed with 20 dogs: first, construction of a cervical esophagostomy to measure the antroduodenal motility and gastric pH-metry as validation step. The manometry was performed by means of a six point electronic manometry probe and both manometry and pH-metry were recorded during 4 hours. Second, the stomach's pacemaker region and gastric reservoir were resected by videolaparoscopy. Third, the antroduodenal motility and gastric pH-metry were measured again. RESULTS: In the validation step, there was established a typical dogs' antroduodenal motility pattern, with a three-shaped interdigestive motility complex (IMC (phases 1 to 3; the gastric pH-metry showed a baseline at pH 1,15. After partial gastric resection, overall there was an increase in contractions' frequency, an increase in phase 2 and a decrease in phase 3 participation on the IMC's. Regarding the gastric pH measurements, there was an increase in pH intervals 0-1 and 1-2 and a decrease in pH intervals 6-7; overall, there was a decrease in the stomach's pH and a decrease in the prandial time. CONCLUSION: The resection of the stomach's pacemaker region and gastric reservoir correlated with alterations in antroduodenal motility, maintaining however the typical IMC pattern.

  2. Recent Developments in R.F. Magnetron Sputtered Thin Films for pH Sensing Applications—An Overview

    OpenAIRE

    D. K. Maurya; A. Sardarinejad; K. Alameh

    2014-01-01

    pH sensors are widely used in chemical and biological applications. Metal oxides-based pH sensors have many attractive features including insolubility, stability, mechanical strength, electrocatalyst and manufacturing technology. Various metal oxide thin films prepared by radio frequency (R.F.) magnetron sputtering have attractive features, including high pH sensitivity, fast response, high resolution, good stability and reversibility as well as potential for measuring pH under conditions th...

  3. Nonlinear method for including the mass uncertainty of standards and the system measurement errors in the fitting of calibration curves

    International Nuclear Information System (INIS)

    Pickles, W.L.; McClure, J.W.; Howell, R.H.

    1978-01-01

    A sophisticated nonlinear multiparameter fitting program was used to produce a best fit calibration curve for the response of an x-ray fluorescence analyzer to uranium nitrate, freeze dried, 0.2% accurate, gravimetric standards. The program is based on unconstrained minimization subroutine, VA02A. The program considers the mass values of the gravimetric standards as parameters to be fit along with the normal calibration curve parameters. The fitting procedure weights with the system errors and the mass errors in a consistent way. The resulting best fit calibration curve parameters reflect the fact that the masses of the standard samples are measured quantities with a known error. Error estimates for the calibration curve parameters can be obtained from the curvature of the ''Chi-Squared Matrix'' or from error relaxation techniques. It was shown that nondispersive XRFA of 0.1 to 1 mg freeze-dried UNO 3 can have an accuracy of 0.2% in 1000 s. 5 figures

  4. BER-3.2 report: Methodology for justification and optimization of protective measures including a case study

    International Nuclear Information System (INIS)

    Hedemann Jensen, P.; Sinkko, K.; Walmod-Larsen, O.; Gjoerup, H.L.; Salo, A.

    1992-07-01

    This report is a part of the Nordic BER-3 project's work to propose and harmonize Nordic intervention levels for countermeasures in case of nuclear accidents. This report focuses on the methodology for justification and optimization of protective measures in case of a reactor accident situation with a large release of fission products to the environment. The down-wind situation is very complicated. The dose to the exposed society is almost unpredictable. The task of the radiation protection experts: To give advice to the decision makers on averted doses by the different actions at hand in the situation - is complicated. That of the decision makers is certainly more: On half of the society they represent, they must decide if they wish to follow the advices from their radiation protection experts or if they wish to add further arguments - economical or political (or personal) - into their considerations before their decisions are taken. Two analysis methods available for handling such situations: cost-benefit analysis and multi-attribute utility analysis are described in principle and are utilized in a case study: The impacts of a Chernobyl-like accident on the Swedish island of Gotland in the Baltic Sea are analyzed with regard to the acute consequences. The use of the intervention principles found in international guidance (IAEA 91, ICRP 91), which can be summarized as the principles of justification, optimization and avoidance of unacceptable doses, are described. How to handle more intangible factors of a psychological or political character is indicated. (au) (6 tabs., 3 ills., 17 refs.)

  5. Calculation of extracted ion beam particle distribution including within-extractor collisions from H-alpha Doppler shift measurements

    International Nuclear Information System (INIS)

    Kim, Tae-Seong; Kim, Jinchoon; In, Sang Ryul; Jeong, Seung Ho

    2008-01-01

    Prototype long pulse ion sources are being developed and tested toward the goal of a deuterium beam extraction of 120 keV/65 A. The latest prototype source consists of a magnetic bucket plasma generator and a four-grid copper accelerator system with multicircular apertures of 568 holes. To measure the angular divergence and the ion species of the ion beam, an optical multichannel analyzer (OMA) system for a Doppler-shifted H-alpha lights was set up at the end of a gas-cell neutralizer. But the OMA data are very difficult to analyze due to a large background level on the top of the three energy peaks (coming from H + , H 2 + , and H 3 + ). These background spectra in the OMA signals seem to result from partially accelerated ion beams in the accelerator. Extracted ions could undergo a premature charge exchange as the accelerator column tends to have a high hydrogen partial pressure from the unused gas from the plasma generator, resulting in a continuous background of partially accelerated beam particles at the accelerator exit. This effect is calculated by accounting for all the possible atomic collision processes and numerically summing up three ion species across the accelerator column. The collection of all the atomic reaction cross sections and the numerical summing up will be presented. The result considerably depends on the background pressure and the ion beam species ratio (H + , H 2 + , and H 3 + ). This effect constitutes more than 20% of the whole particle distribution. And the energy distribution of those suffering from collisions is broad and shows a broad maximum in the vicinity of the half and the third energy region

  6. 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 ...

  7. Conformational changes in human serum albumin studied by fluorescence and absorption spectroscopy. Distance measurements as a function of pH and fatty acids

    DEFF Research Database (Denmark)

    Honoré, B; Pedersen, A O

    1989-01-01

    pH- and fatty acid-induced conformational changes in human serum albumin were investigated by fluorescence-energy transfer, determining the distance between Trp-214 and bound bilirubin at 25 degrees C. This distance changes significantly with the pH, being 2.52 +/- 0.01 nm at pH 6, 2.31 +/- 0.04 nm...... at pH 9, 2.13 +/- 0.07 nm at pH 11.0 and 2.77 nm at pH 11.9. The influence of different fatty acids on the distance was also determined. At pH 7.4 medium-chain fatty acids seem to increase this distance, whereas long-chain fatty acids, at low concentrations, decrease the distance between the two...... chromophores. The contraction of the protein carrying long-chain saturated fatty acids is even more pronounced at pH 9. Udgivelsesdato: 1989-Feb-15...

  8. In vivo measurement of intracellular pH in human brain during different tensions of carbon dioxide in arterial blood. A 31P-NMR study

    DEFF Research Database (Denmark)

    Jensen, K E; Thomsen, C; Henriksen, O

    1988-01-01

    The effect of changes in carbon dioxide tension in arterial blood upon intracellular pH in brain tissue was studied in seven healthy volunteers, aged 22-45 years. The pH changes were monitored by use of 31P nuclear magnetic resonance spectroscopy, performed on a whole-body 1.5 Tesla Siemens imaging...

  9. Initial dissolution rate of a Japanese simulated high-level waste glass P0798 as a function of pH and temperature measured by using micro-channel flow-through test method

    International Nuclear Information System (INIS)

    Inagaki, Yaohiro; Makigaki, Hikaru; Idemitsu, Kazuya; Arima, Tatsumi; Mitsui, Sei-ichiro; Noshita, Kenji

    2012-01-01

    Aqueous dissolution tests were performed for a Japanese type of simulated high-level waste (HLW) glass P0798 by using a newly developed test method of micro-channel flow-through (MCFT) method, and the initial dissolution rate of glass matrix, r 0 , was measured as a function of solution pH (3-11) and temperature (25-90degC) precisely and consistently for systematic evaluation of the dissolution kinetics. The MCFT method using a micro-channel reactor with a coupon shaped glass specimen has the following features to provide precise and consistent data on the glass dissolution rate: (1) any controlled constant solution condition can be provided over the test duration; (2) the glass surface area actually reacting with solution can be determined accurately; and (3) direct and totally quantitative analyses of the reacted glass surface can be performed for confirming consistency of the test results. The present test results indicated that the r 0 shows a 'V-shaped' pH dependence with a minimum at around pH 6 at 25degC, but it changes to a 'U-shaped' one with a flat bottom at neutral pH at elevated temperatures of up to 90degC. The present results also indicated that the r 0 increases with temperature according to an Arrhenius law at any pH, and the apparent activation energy evaluated from Arrhenius relation increases with pH from 54 kJ/mol at pH 3 to 76 kJ/mol at pH 10, which suggests that the dissolution mechanism changes depending on pH. (author)

  10. 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.

  11. Simultaneous estimation of a binary mixture of a weak acid and a strong acid by volumetric titration and pH measurement

    International Nuclear Information System (INIS)

    Karmakar, Sanat; Mallika, C.; Kamachi Mudali, U.

    2012-01-01

    High level liquid waste (HLLW) generated in the aqueous reprocessing of spent nuclear fuels for the separation of uranium and plutonium by PUREX process, comprises the fission and corrosion products in 4 M nitric acid. Reduction in waste volume is accomplished by destroying the acidity of the waste solution from 4 to less than 2 M by treating it with formaldehyde and subsequent concentration by evaporation. In the denitration by HCHO, nitric acid in the waste solution is reduced to NOx and water via nitrous acid as the intermediate product: whereas formaldehyde is oxidized to formic acid which is converted to CO 2 and H 2 O subsequently. The reaction is highly exothermic and the release of all gaseous products may lead to uncontrollable process conditions. Hence, for the safe operation, it is desirable to estimate the concentration of residual formic acid as well as nitric acid in the product stream as a function of time. The acidity in the feed solution is 4 M and the concentration of HNO 3 in the product solution is in the range 1- 4 M. Since the formic acid generated during the reaction will be consumed immediately, the concentration of residual acid will be in the range 0.05-0.5 M. A simultaneous titration method based on pH measurement and volumetric analysis has been developed in the present work for the quantitative determination of the weak acid (HCOOH)with known pKa value and the strong acid (HNO 3 ) in the binary mixture

  12. Effect of diet phase change, dietary Ca and P level and phytase on bird performance and real-time gizzard pH measurements.

    Science.gov (United States)

    Lee, S A; Dunne, J; Mottram, T; Bedford, M R

    2017-06-01

    In this study, a novel capsule technique was used to capture real-time pH readings from the gizzard over several hours, in response to different dietary treatments. 1. The first experiment was a preliminary study into capsule administration and pH recordings using 9 male Ross 308 broilers from 20 d. In the second experiment, broilers (576) were fed in two phases (0-21 and 21-42 d) with 4 treatment groups; low and adequate Ca and AvP diets with and without Quantum Blue phytase (1500 FTU/kg). Capsules were administered to 8 birds from each treatment group, pre and post diet phase change, with readings captured over a 2.5 h period. 2. Phytase addition improved body weight gain (BWG) and feed conversion ratio (FCR) of birds fed low dietary Ca, while having no significant effect on birds fed adequate Ca diets. Unexpectantly, diets with higher Ca levels gave a lower average gizzard pH compared to the low Ca diet. Phytase addition, irrespective of Ca level, increased average gizzard pH. Fluctuations in gizzard pH (0.6-3.8) were observed across all treatment groups. Higher frequencies of pH readings below pH 1.0 were seen in birds fed an adequate Ca diet and with phytase supplementation of a low Ca diet. 3. These results signify the potential use of capsule techniques to monitor real-time pH changes. The implication on gastric protein and fibre hydrolysis as a result of large fluctuations in pH should be considered.

  13. 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.

  14. 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.

  15. Measurement and evaluation of the effects of pH gradients on the antimicrobial and antivirulence activities of chitosan nanoparticles in Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Fadilah Sfouq Aleanizy

    2018-01-01

    Full Text Available Objective: The purpose of this study was to study the antimicrobial activity of chitosan nanoparticles (CSNPs on Pseudomonas aeruginosa with special emphasis on their sensitivity to pH and the effect of pH on their activity. Methodology: Antimicrobial activity of CSNPs against Pseudomonas aeruginosa at different pH was tested using broth dilution method. Further assessment of antivirulence activity and sensitization of CSNPs on Pseudomonas aeruginosa were examined. Results: Significant antimicrobial effects of CSNPs against Pseudomonas aeruginosa were detected at slightly acidic pH 5, whereas the activity was abolished at a pH of greater than 7. The antivirulence activity of CSNPs was then investigated and treatment with CSNPs (1000 ppm resulted in a significant reduction or even complete inhibition of pyocyanin production by P. aeruginosa compared with untreated P. aeruginosa indicating the antivirulence activity of CSNPs. CSNPs also sensitized P. aeruginosa to the lytic effects of sodium dodecyl sulfate (SDS; such sensitization was not blocked by washing chitosan-treated cells prior to SDS exposure revealing that CSNPs disturb the outer membrane leading to irreversible sensitivity to detergent even at low concentration (100 ppm. Conclusions: These findings highlight CSNPs as potentially useful as indirect antimicrobial agents for a variety of applications. Keywords: Chitosan nanoparticles, Pseudomonas aeruginosa, pH, Antimicrobial, Virulence

  16. Continuous and long term measurement of reticuloruminal pH in crossbreed dairy cows in Brazil by an indwelling and wireless data transmitting unit

    Directory of Open Access Journals (Sweden)

    J. Gasteiner

    2015-04-01

    Full Text Available O objetivo do presente experimento foi medir continuamente valores de pH e temperatura em vacas leiteiras usando uma unidade interna de transmissão de dados sem fio. Valores de pH retículo-ruminais foram medidos automaticamente a cada 600 segundos por um período de 50 dias em três vacas leiteiras Holandesas, no pós-parto recente. Valores de pH retículo-ruminais médios diferiram (P<0,05 entre as três vacas (5,69±0,20; 6,10±0,18; 5,99±0,15, assim como o tempo em minutos por dia (332; 23; 18 mantido abaixo de pH 5,5. A variação diurna de pH nas vacas 2 e 3 demonstrou um padrão circadiano e frequente, como consequência dos momentos de fornecimento da alimentação e da ingestão alimentar, respectivamente. Esse padrão diário não pode ser observado no padrão de pH da vaca 1. Os picos e os valores baixos de pH na vaca 1 eram aleatórios, sem relação evidente com os momentos de alimentação, e as amplitudes de pH eram igualmente desordenadas. O valor de pH retículo-ruminal permaneceu anormalmente baixo nesta vaca durante todo o período de observação, caracterizando uma acidose ruminal subaguda. A temperatura retículo-ruminal da vaca 1 foi mais baixa (38.8°C; 39.1°C; 39.0°C e ela bebeu mais frequentemente por dia (9,5; 6,4; 7,0 quando comparada com as vacas 2 e 3 (P<0,05. O exame clínico revelou um deslocamento de abomaso à esquerda (DAE. Pela literatura consultada, este é o primeiro relato indicando um padrão de pH e temperatura em uma vaca com DAE.

  17. 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...

  18. Metal/Metal Oxide Differential Electrode pH Sensors

    Science.gov (United States)

    West, William; Buehler, Martin; Keymeulen, Didier

    2007-01-01

    Solid-state electrochemical sensors for measuring the degrees of acidity or alkalinity (in terms of pH values) of liquid solutions are being developed. These sensors are intended to supplant older electrochemical pH sensors that include glass electrode structures and reference solutions. The older sensors are fragile and subject to drift. The present developmental solid-state sensors are more rugged and are expected to be usable in harsh environments. The present sensors are based on a differential-electrode measurement principle. Each sensor includes two electrodes, made of different materials, in equilibrium with the solution of interest.

  19. Intracellular pH in human brain measured by P-31 MR spectroscopy during changes in arterial CO/sub 2/ tension

    International Nuclear Information System (INIS)

    Jensen, K.E.; Thomsen, C.; Henriksen, O.

    1987-01-01

    Six healthy volunteers were examined. A 1.5-T Siemens whole-body scanner was used. A three-turn solenoid surface coil was used. Sixty-four acquisitions with a repetition time of 6 seconds were recorded. The subjects hyperventilated and inhaled air with 5% and 7% CO/sub 2/. The breathing of air with 5% CO/sub 2/ resulted in an arterial blood tension of 40 mm Hg, and no changes in pH could be detected. Breathing of air with 7% CO/sub 2/ resulted in arterial tension of 55 mm Hg and gave a decrease of 0.1 pH unit. The spectra after 15 minutes of hyperventilation showed an increase of 0.1 pH unit

  20. Kinetic Rate Law Parameter Measurements on a Borosilicate Waste Glass: Effect of Temperature, pH, and Solution Composition on Alkali Ion Exchange

    International Nuclear Information System (INIS)

    Pierce, Eric M.; McGrail, B PETER.; Icenhower, J P.; Rodriguez, Elsa A.; Steele, Jackie L.; Baum, Steven R.

    2004-01-01

    The reaction kinetics of glass is controlled by matrix dissolution and ion exchange (IEX). Dissolution of an alkali-rich simulated borosilicate waste glass was investigated using single-pass flow-through (SPFT) experiments. Experiments were conducted as a function of temperature, pH, and solution composition by varying the SiO 2 (aq) activity in the influent solution. Results showed that under dilute conditions matrix dissolution increased with increasing pH and temperature, and decreased with increasing SiO 2 (aq) activity. IEX rates decreased with increasing pH and temperature, and increased with increasing SiO 2 (aq) activity. Over the solution composition range interrogated in this study the dominant dissolution mechanism changed from matrix dissolution to IEX. These results suggest that ''secondary'' reactions may become dominant under certain environmental conditions and emphasize the need to incorporate these reactions into dissolution rate models

  1. Reproducibility of 24-hour combined multiple intraluminal impedance (MII) and pH measurements in infants and children. Evaluation of a diagnostic procedure for gastroesophageal reflux disease

    DEFF Research Database (Denmark)

    Dalby, Kasper; Nielsen, Rasmus G; Markoew, Simone

    2007-01-01

    Gastroesophageal reflux disease (GERD) is a common disease in infants and children. Prolonged (24-hr) pH monitoring in the esophagus for determination of increased acid exposure has, together with endoscopy, been the only routinely implemented method for GERD diagnosis. The recently introduced...... of nonacid and acidic reflux episodes) and pH in the esophagus in infants and children. Upper endoscopy followed by 2 x 24-hr consecutive combined MII and pH monitoring was performed in 33 infants and children referred to a tertiary center for evaluation of GERD. The study was performed in a hospital setting...... without dietary restrictions. Bland-Altman difference versus mean plots and calculation of the limits of agreement (LOA) were used for assessment of the reproducibility of the total number of acidic and nonacidic reflux episodes. LOA for the number of acidic reflux episodes on day 2 were 0.2-5.3 times...

  2. K[subscript a] and K[subscript b] from pH and Conductivity Measurements: A General Chemistry Laboratory Exercise

    Science.gov (United States)

    Nyasulu, Frazier; Moehring, Michael; Arthasery, Phyllis; Barlag, Rebecca

    2011-01-01

    The acid ionization constant, K[subscript a], of acetic acid and the base ionization constant, K[subscript b], of ammonia are determined easily and rapidly using a datalogger, a pH sensor, and a conductivity sensor. To decrease sample preparation time and to minimize waste, sequential aliquots of a concentrated standard are added to a known volume…

  3. BioPhotonics workstation: A versatile setup for simultaneous optical manipulation, heat stress, and intracellular pH measurements of a live yeast cell

    DEFF Research Database (Denmark)

    Aabo, Thomas; Bañas, Andrew Rafael; Glückstad, Jesper

    2011-01-01

    for fast temperature variations while trapping. Using this modified BWS setup, we investigated the internal pH (pHi) response and membrane integrity of an optically trapped Saccharomyces cerevisiae cell at 5 mW subject to increasing temperatures. The pHi of the cell is obtained from the emission of 5-(and...

  4. Monitoring of the Proton Electrochemical Gradient in Reconstituted Vesicles: Quantitative Measurements of Both Transmembrane Potential and Intravesicular pH by Ratiometric Fluorescent Probes

    Czech Academy of Sciences Publication Activity Database

    Holoubek, A.; Večeř, J.; Sigler, Karel

    2007-01-01

    Roč. 17, - (2007), s. 201-213 ISSN 1053-0509 Institutional research plan: CEZ:AV0Z50200510 Keywords : transmembrane potential * intracellular ph * oxonol dyes Subject RIV: EE - Microbiology, Virology Impact factor: 2.101, year: 2007

  5. Optoelectronic pH Meter: Further Details

    Science.gov (United States)

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

    2009-01-01

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

  6. A simple, generalizable method for measuring individual research productivity and its use in the long-term analysis of departmental performance, including between-country comparisons.

    Science.gov (United States)

    Wootton, Richard

    2013-01-14

    A simple, generalizable method for measuring research output would be useful in attempts to build research capacity, and in other contexts. A simple indicator of individual research output was developed, based on grant income, publications and numbers of PhD students supervised. The feasibility and utility of the indicator was examined by using it to calculate research output from two similarly-sized research groups in different countries. The same indicator can be used to assess the balance in the research "portfolio" of an individual researcher. Research output scores of 41 staff in Research Department A had a wide range, from zero to 8; the distribution of these scores was highly skewed. Only about 20% of the researchers had well-balanced research outputs, with approximately equal contributions from grants, papers and supervision. Over a five-year period, Department A's total research output rose, while the number of research staff decreased slightly, in other words research productivity (output per head) rose. Total research output from Research Department B, of approximately the same size as A, was similar, but slightly higher than Department A. The proposed indicator is feasible. The output score is dimensionless and can be used for comparisons within and between countries. Modeling can be used to explore the effect on research output of changing the size and composition of a research department. A sensitivity analysis shows that small increases in individual productivity result in relatively greater increases in overall departmental research output. The indicator appears to be potentially useful for capacity building, once the initial step of research priority setting has been completed.

  7. Effect of pH on structure, function, and stability of mitochondrial carbonic anhydrase VA.

    Science.gov (United States)

    Idrees, Danish; Shahbaaz, Mohd; Bisetty, Krishna; Islam, Asimul; Ahmad, Faizan; Hassan, Md Imtaiyaz

    2017-02-01

    Mitochondrial carbonic anhydrase VA (CAVA) catalyzes the hydration of carbon dioxide to produce proton and bicarbonate which is primarily expressed in the mitochondrial matrix of liver, and involved in numerous physiological processes including lipogenesis, insulin secretion from pancreatic cells, ureagenesis, gluconeogenesis, and neuronal transmission. To understand the effect of pH on the structure, function, and stability of CAVA, we employed spectroscopic techniques such as circular dichroism, fluorescence, and absorbance measurements in wide range of pH (from pH 2.0 to pH 11.5). CAVA showed an aggregation at acidic pH range from pH 2.0 to pH 5.0. However, it remains stable and maintains its secondary structure in the pH range, pH 7.0-pH 11.5. Furthermore, this enzyme has an appreciable activity at more than pH 7.0 (7.0 < pH ≤ 11.5) with maximum activity at pH 9.0. The maximal values of k cat and k cat /K m at pH 9.0 are 3.7 × 10 6  s -1 and 5.5 × 10 7  M -1  s -1 , respectively. However, this enzyme loses its activity in the acidic pH range. We further performed 20-ns molecular dynamics simulation of CAVA to see the dynamics at different pH values. An excellent agreement was observed between in silico and in vitro studies. This study provides an insight into the activity of CAVA in the pH range of subcellular environment.

  8. Aerosol measurement: the use of optical light scattering for the determination of particulate size distribution, and particulate mass, including the semi-volatile fraction.

    Science.gov (United States)

    Grimm, Hans; Eatough, Delbert J

    2009-01-01

    The GRIMM model 1.107 monitor is designed to measure particle size distribution and particulate mass based on a light scattering measurement of individual particles in the sampled air. The design and operation of the instrument are described. Protocols used to convert the measured size number distribution to a mass concentration consistent with U.S. Environmental Protection Agency protocols for measuring particulate matter (PM) less than 10 microm (PM10) and less than 2.5 microm (PM2.5) in aerodynamic diameter are described. The performance of the resulting continuous monitor has been evaluated by comparing GRIMM monitor PM2.5 measurements with results obtained by the Rupprecht and Patashnick Co. (R&P) filter dynamic measurement system (FDMS). Data were obtained during month-long studies in Rubidoux, CA, in July 2003 and in Fresno, CA, in December 2003. The results indicate that the GRIMM monitor does respond to total PM2.5 mass, including the semi-volatile components, giving results comparable to the FDMS. The data also indicate that the monitor can be used to estimate water content of the fine particles. However, if the inlet to the monitor is heated, then the instrument measures only the nonvolatile material, more comparable to results obtained with a conventional heated filter tapered element oscillating microbalance (TEOM) monitor. A recent modification of the model 180, with a Nafion dryer at the inlet, measures total PM2.5 including the nonvolatile and semi-volatile components, but excluding fine particulate water. Model 180 was in agreement with FDMS data obtained in Lindon, UT, during January through February 2007.

  9. 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

  10. 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.

  11. 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.

  12. Measurement of distribution coefficients of U series radionuclides on soils under shallow land environment (2). pH dependence of distribution coefficients

    International Nuclear Information System (INIS)

    Sakamoto, Yoshiaki; Takebe, Shinichi; Ogawa, Hiromichi; Inagawa, Satoshi; Sasaki, Tomozou

    2001-01-01

    In order to study sorption behavior of U series radionuclides (Pb, Ra, Th, Ac, Pa and U) under aerated zone environment (loam-rain water system) and aquifer environment (sand-groundwater system) for safety assessment of U bearing waste, pH dependence of distribution coefficients of each element has been obtained. The pH dependence of distribution coefficients of Pb, Ra, Th, Ac and U was analyzed by model calculation based on aqueous speciation of each element and soil surface charge characteristics, which is composed of a cation exchange capacity and surface hydroxyl groups. From the model calculation, the sorption behavior of Pb, Ra, Th, Ac and U could be described by a combination of cation exchange reaction and surface-complexation model. (author)

  13. Field Measurements of Trace Gases and Aerosols Emitted by Undersampled Combustion Sources Including Wood and Dung Cooking Fires, Garbage and Crop Residue Burning, and Indonesian Peat Fires

    Science.gov (United States)

    Stockwell, C.; Jayarathne, T. S.; Goetz, D.; Simpson, I. J.; Selimovic, V.; Bhave, P.; Blake, D. R.; Cochrane, M. A.; Ryan, K. C.; Putra, E. I.; Saharjo, B.; Stone, E. A.; DeCarlo, P. F.; Yokelson, R. J.

    2017-12-01

    Field measurements were conducted in Nepal and in the Indonesian province of Central Kalimantan to improve characterization of trace gases and aerosols emitted by undersampled combustion sources. The sources targeted included cooking with a variety of stoves, garbage burning, crop residue burning, and authentic peat fires. Trace gas and aerosol emissions were studied using a land-based Fourier transform infrared spectrometer, whole air sampling, photoacoustic extinctiometers (405 and 870nm), and filter samples that were analyzed off-line. These measurements were used to calculate fuel-based emission factors (EFs) for up to 90 gases, PM2.5, and PM2.5 constituents. The aerosol optical data measured included EFs for the scattering and absorption coefficients, the single scattering albedo (at 870 and 405 nm), as well as the absorption Ångström exponent. The emissions varied significantly by source, although light absorption by both brown and black carbon (BrC and BC, respectively) was important for all non-peat sources. For authentic peat combustion, the emissions of BC were negligible and absorption was dominated by organic aerosol. The field results from peat burning were in reasonable agreement with recent lab measurements of smoldering Kalimantan peat and compare well to the limited data available from other field studies. The EFs can be used with estimates of fuel consumption to improve regional emissions inventories and assessments of the climate and health impacts of these undersampled sources.

  14. Direct measurement of CO2 solubility and pH in NaCl hydrothermal solutions by combining in-situ potentiometry and Raman spectroscopy up to 280 °C and 150 bar

    Science.gov (United States)

    Truche, Laurent; Bazarkina, Elena F.; Berger, Gilles; Caumon, Marie-Camille; Bessaque, Gilles; Dubessy, Jean

    2016-03-01

    The in-situ monitoring of aqueous solution chemistry at elevated temperatures and pressures is a major challenge in geochemistry. Here, we combined for the first time in-situ Raman spectroscopy for concentration measurements and potentiometry for pH measurement in a single hydrothermal cell equipped with sampling systems and operating under controlled conditions of temperature and pressure. Dissolved CO2 concentration and pH were measured at temperatures up to 280 °C and pressures up to 150 bar in the H2O-CO2 and H2O-CO2-NaCl systems. A Pitzer specific-ion-interaction aqueous model was developed and confirmed the accuracy and consistency of the measurements, at least up to 250 °C. The revised Pitzer parameters for the H2O-CO2-NaCl system were formatted for the Phreeqc geochemical software. Significant changes with respect to the Pitzer.dat database currently associated with Phreeqc were observed. The new model parameters are now available for further applications. The Raman and pH probes tested here may also be applied to field monitoring of hydrothermal springs, geothermal wells, and oil and gas boreholes.

  15. Prediction of preterm birth in multiple pregnancies: development of a multivariable model including cervical length measurement at 16 to 21 weeks' gestation.

    Science.gov (United States)

    van de Mheen, Lidewij; Schuit, Ewoud; Lim, Arianne C; Porath, Martina M; Papatsonis, Dimitri; Erwich, Jan J; van Eyck, Jim; van Oirschot, Charlotte M; Hummel, Piet; Duvekot, Johannes J; Hasaart, Tom H M; Groenwold, Rolf H H; Moons, Karl G M; de Groot, Christianne J M; Bruinse, Hein W; van Pampus, Maria G; Mol, Ben W J

    2014-04-01

    To develop a multivariable prognostic model for the risk of preterm delivery in women with multiple pregnancy that includes cervical length measurement at 16 to 21 weeks' gestation and other variables. We used data from a previous randomized trial. We assessed the association between maternal and pregnancy characteristics including cervical length measurement at 16 to 21 weeks' gestation and time to delivery using multivariable Cox regression modelling. Performance of the final model was assessed for the outcomes of preterm and very preterm delivery using calibration and discrimination measures. We studied 507 women, of whom 270 (53%) delivered models for preterm and very preterm delivery had a c-index of 0.68 (95% CI 0.63 to 0.72) and 0.68 (95% CI 0.62 to 0.75), respectively, and showed good calibration. In women with a multiple pregnancy, the risk of preterm delivery can be assessed with a multivariable model incorporating cervical length and other predictors.

  16. Ultrasonic measurement of elastic moduli of 17-4 pH stainless steel and uranium -2 molybdenum from -400C to 8000C

    International Nuclear Information System (INIS)

    Gieske, J.H.

    1980-10-01

    Young's Modulus, shear modulus, and Poisson's ratio for 17-4 pH stainless steel and uranium -2 molybdenum are calculated from ultrasonic longitudinal and shear velocities determined from -40 0 C to 800 0 C. The ultrasonic velocities were determined at elevated temperatures using a through-transmission buffer rod arrangement. An indium-gallium slurry bond was used as an ultrasonic couplant between Cupernickel 10 alloy buffer rods and the specimen. Microstructural changes and phase transitions in the specimens are evident from the temperature dependence of the ultrasonic data. 10 figures, 3 tables

  17. 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.

  18. 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.

  19. Using patient reported outcome measures in health services: A qualitative study on including people with low literacy skills and learning disabilities

    Directory of Open Access Journals (Sweden)

    Jahagirdar Deepa

    2012-11-01

    Full Text Available Abstract Background Patient reported outcome measures (PROMs are self-report measures of health status increasingly promoted for use in healthcare quality improvement. However people with low literacy skills or learning disabilities may find PROMs hard to complete. Our study investigated stakeholder views on the accessibility and use of PROMs to develop suggestions for more inclusive practice. Methods Taking PROMs recommended for chronic obstructive pulmonary disease (COPD as an example, we conducted 8 interviews with people with low literacy skills and/or learning disabilities, and 4 focus groups with 20 health professionals and people with COPD. Discussions covered the format and delivery of PROMs using the EQ-5D and St George Respiratory Questionnaire as prompts. Thematic framework analysis focused on three main themes: Accessibility, Ease of Use, and Contextual factors. Results Accessibility included issues concerning the questionnaire format, and suggestions for improvement included larger font sizes and more white space. Ease of Use included discussion about PROMs’ administration. While health professionals suggested PROMs could be completed in waiting rooms, patients preferred settings with more privacy and where they could access help from people they know. Contextual Factors included other challenges and wider issues associated with completing PROMs. While health professionals highlighted difficulties created by the system in managing patients with low literacy/learning disabilities, patient participants stressed that understanding the purpose of PROMs was important to reduce intimidation. Conclusions Adjusting PROMs’ format, giving an explicit choice of where patients can complete them, and clearly conveying PROMs’ purpose and benefit to patients may help to prevent inequality when using PROMs in health services.

  20. The 100th anniversary of pH (1909-2009. Negative logarithms for measuring hydrogen ions: are they essential in medicine? Part I

    Directory of Open Access Journals (Sweden)

    Francesco Sgambato

    2013-03-01

    Full Text Available Introduction: It has been 100 years since the concept of pH (1909-2009 was ‘‘invented’’ by the Danish chemist-mathematician Søren Peter Lauritz Sørensen (1868-1939 in the chemistry laboratories of the Carlsberg Brewery in Copenhagen. The anniversary provides an opportunity to examine the crucial importance in human life of acid-base balance. Materials and methods: The authors review the historical process that led to the creation of the pH scale, with citation of passages from the original work of Sørensen published 100 years ago. This is followed by a critical analysis of the debate regarding the use of logarithmstomeasure hydrogen ion concentrations based on data from scientific papers published over the past 50 years (1960-2010. Results and discussion: The authors conclude that the concept of acid-base balance can be approached and taught in a simpler, more exciting, and even pleasant fashion without using the infamous and abstruse Henderson-Hasselbalch equation. The whole rationale underlying the understanding and clinical application of this vital topic is clearly and unquestionably inherent simpler, more manageable formula introduced by Henderson (without logs, which is useful and quite adequate for use in medical education.

  1. 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...

  2. Unexpected results from direct measurement, with a torsion microbalance in a closed system, of calcification rates of the coral Agaricia agaricites (Scleractinia:Agariicidae and concomitant changes in seawater pH

    Directory of Open Access Journals (Sweden)

    Ian M. Sandeman

    2014-09-01

    Full Text Available Ocean acidification is impacting the calcification of corals, but the mechanisms of calcification are still unclear. To explore the relationship between calcification and pH, small pieces of coral were suspended from a torsion microbalance in gently stirred, temperature controlled, seawater in a closed chamber. Net calcification rate and pH were continuously monitored while light, temperature or pH could be manipulated. The coral pieces were from the edges of thin plates of Agaricia agaricites and were studied alive and freshly collected. Unexpectedly, when calcification was taking place (n=9, 0.082 mg.hr-1.cm-2, as determined by weight increase, the pH of the surrounding seawater medium changed little (n=10, -0.0047 pH units.hr-1.cm-2. When calcification was not taking place the decrease of seawater pH was an order of magnitude higher, -0.013 pH units.hr-1.cm-2. This is the opposite of what is expected when calcium carbonate (CaCO3 forms. Similarly, fresh skeleton initially showed no change of pH in the seawater medium although the rates of weight gain were high (upto 1.0 mg hr-1.cm-2. After 10 hours, as the rate of deposition decreased following a generalized Michaelis-Menten growth curve, the pH began to decrease dramatically indicating an increase of CO2 in the seawater. These unexpected results can be explained if unstable calcium bicarbonate (Ca(HCO³2 is formed in the organic matrix/carbonic anhydrase surface and slowly transforms later to CaCO3. Pieces of living coral monitored in the chamber for 30 hours gained weight during the day and loss it at night. The loss would be consistent with the transformation of Ca(HCO³2 to CaCO3 with the release of CO2. The mean calcification rate of live coral was greater (n=8, p=0.0027 in high light (120 μmol.s-1.m-2 at 0.098 mg.hr-1.cm-2, compared to 0.063 mg.hr-1.cm-2 in low light (12 μmol.s-1.m-2. However, at the same time the mean rate of pH change was -0.0076 under low light compared to -0

  3. Umbilical Cord Blood pH in Intrapartum Hypoxia.

    Science.gov (United States)

    Perveen, Fouzia; Khan, Ayesha; Ali, Tahmina; Rabia, Syeda

    2015-09-01

    To determine the association of cord arterial blood pH with neonatal outcome in cases of intrapartum fetal hypoxia. Descriptive analytical study. Gynaecology Unit-II, Civil Hospital, Karachi, from September 2011 to November 2012. All singleton cephalic fetuses at term gestation were included in the study. Those with any anomaly, malpresentation, medical disorders, maternal age 7.25, neonatal outcome measures (healthy, NICU admission or neonatal death), color of liquor and mode of delivery recorded on predesigned proforma. Statistical analysis performed by SPSS 16 by using independent-t test or chi-square test and ANOVA test as needed. A total of 204 newborns were evaluated. The mean pH level was found to be significantly different (p=0.007) in two groups. The pH value 7.25 had significant association (p 7.25. Majority (63.6%) cases needed caesarean section as compared to 31.4% controls. There is a significant association of cord arterial blood pH at birth with neonatal outcome at pH 7.25; but below the level of pH 7.25 it is still inconclusive.

  4. Effect of temperature, pH, and water activity on biofilm formation by Salmonella enterica enteritidis PT4 on stainless steel surfaces as indicated by the bead vortexing method and conductance measurements.

    Science.gov (United States)

    Giaouris, E; Chorianopoulos, N; Nychas, G J E

    2005-10-01

    An assay was developed in an effort to elucidate the effect of important environmental parameters (temperature, pH, and water activity [aw]) on Salmonella Enteritidis biofilm formation on stainless steel surfaces. To achieve this, a modified microbiological technique used for biofilm studying (the bead vortexing method) and a rapid method based on conductivity measurements were used. The ability of the microorganism to generate biofilm on the stainless surfaces was studied at three temperatures (5, 20, and 37 degrees C), four pH values (4.5, 5.5, 6.5, and 7.4), and four aw values (0.5, 1.5, 5.5, and 10.5% NaCl). Results obtained by the bead vortexing method show that maximum numbers of adherent bacteria per square centimeter (106 CFU/cm2) were attained in 6 days at 20 degrees C. Biofilm formation after 7 days of incubation at 20 degrees C was found to be independent of the pH value. In addition, the high concentration of sodium chloride (10.5% NaCl, aw = 0.94) clearly inhibited the adherence of cells to the coupons. Conductance measurements were used as a supplementary tool to measure indirectly the attachment and biofilm formation of bacterial cells on stainless steel surfaces via their metabolic activity (i.e., changes in the conductance of the growth medium due to microbial growth or metabolism). Results obtained by conductance measurements corresponded well to those of the bead vortexing method. Furthermore, we were able to detect cells that remained attached on the metal surfaces even after vortexing via their metabolic activity. The results, except for demonstrating environmental-dependent Salmonella Enteritidis biofilm formation, indicated that traditional vortexing with beads did not remove completely biofilm cells from stainless steel; hence, conductance measurements seem to provide a more sensitive test capable to detect down to one single viable organism.

  5. Empirical algorithms to estimate water column pH in the Southern Ocean

    Science.gov (United States)

    Williams, N. L.; Juranek, L. W.; Johnson, K. S.; Feely, R. A.; Riser, S. C.; Talley, L. D.; Russell, J. L.; Sarmiento, J. L.; Wanninkhof, R.

    2016-04-01

    Empirical algorithms are developed using high-quality GO-SHIP hydrographic measurements of commonly measured parameters (temperature, salinity, pressure, nitrate, and oxygen) that estimate pH in the Pacific sector of the Southern Ocean. The coefficients of determination, R2, are 0.98 for pH from nitrate (pHN) and 0.97 for pH from oxygen (pHOx) with RMS errors of 0.010 and 0.008, respectively. These algorithms are applied to Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) biogeochemical profiling floats, which include novel sensors (pH, nitrate, oxygen, fluorescence, and backscatter). These algorithms are used to estimate pH on floats with no pH sensors and to validate and adjust pH sensor data from floats with pH sensors. The adjusted float data provide, for the first time, seasonal cycles in surface pH on weekly resolution that range from 0.05 to 0.08 on weekly resolution for the Pacific sector of the Southern Ocean.

  6. 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

  7. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system

    OpenAIRE

    Raimondo, Joseph V.; Joyce, Bradley; Kay, Louise; Schlagheck, Theresa; Newey, Sarah E.; Srinivas, Shankar; Akerman, Colin J.

    2013-01-01

    Within the nervous system, intracellular Cl− and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission, and network excitability. Cl− and pH are often co-regulated, and network activity results in the movement of both Cl− and H+. Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl− and pH sensors have been described previously, these either l...

  8. 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.

  9. Uncertainty in Measurement: A Review of Monte Carlo Simulation Using Microsoft Excel for the Calculation of Uncertainties Through Functional Relationships, Including Uncertainties in Empirically Derived Constants

    Science.gov (United States)

    Farrance, Ian; Frenkel, Robert

    2014-01-01

    The Guide to the Expression of Uncertainty in Measurement (usually referred to as the GUM) provides the basic framework for evaluating uncertainty in measurement. The GUM however does not always provide clearly identifiable procedures suitable for medical laboratory applications, particularly when internal quality control (IQC) is used to derive most of the uncertainty estimates. The GUM modelling approach requires advanced mathematical skills for many of its procedures, but Monte Carlo simulation (MCS) can be used as an alternative for many medical laboratory applications. In particular, calculations for determining how uncertainties in the input quantities to a functional relationship propagate through to the output can be accomplished using a readily available spreadsheet such as Microsoft Excel. The MCS procedure uses algorithmically generated pseudo-random numbers which are then forced to follow a prescribed probability distribution. When IQC data provide the uncertainty estimates the normal (Gaussian) distribution is generally considered appropriate, but MCS is by no means restricted to this particular case. With input variations simulated by random numbers, the functional relationship then provides the corresponding variations in the output in a manner which also provides its probability distribution. The MCS procedure thus provides output uncertainty estimates without the need for the differential equations associated with GUM modelling. The aim of this article is to demonstrate the ease with which Microsoft Excel (or a similar spreadsheet) can be used to provide an uncertainty estimate for measurands derived through a functional relationship. In addition, we also consider the relatively common situation where an empirically derived formula includes one or more ‘constants’, each of which has an empirically derived numerical value. Such empirically derived ‘constants’ must also have associated uncertainties which propagate through the functional

  10. Uncertainty in measurement: a review of monte carlo simulation using microsoft excel for the calculation of uncertainties through functional relationships, including uncertainties in empirically derived constants.

    Science.gov (United States)

    Farrance, Ian; Frenkel, Robert

    2014-02-01

    The Guide to the Expression of Uncertainty in Measurement (usually referred to as the GUM) provides the basic framework for evaluating uncertainty in measurement. The GUM however does not always provide clearly identifiable procedures suitable for medical laboratory applications, particularly when internal quality control (IQC) is used to derive most of the uncertainty estimates. The GUM modelling approach requires advanced mathematical skills for many of its procedures, but Monte Carlo simulation (MCS) can be used as an alternative for many medical laboratory applications. In particular, calculations for determining how uncertainties in the input quantities to a functional relationship propagate through to the output can be accomplished using a readily available spreadsheet such as Microsoft Excel. The MCS procedure uses algorithmically generated pseudo-random numbers which are then forced to follow a prescribed probability distribution. When IQC data provide the uncertainty estimates the normal (Gaussian) distribution is generally considered appropriate, but MCS is by no means restricted to this particular case. With input variations simulated by random numbers, the functional relationship then provides the corresponding variations in the output in a manner which also provides its probability distribution. The MCS procedure thus provides output uncertainty estimates without the need for the differential equations associated with GUM modelling. The aim of this article is to demonstrate the ease with which Microsoft Excel (or a similar spreadsheet) can be used to provide an uncertainty estimate for measurands derived through a functional relationship. In addition, we also consider the relatively common situation where an empirically derived formula includes one or more 'constants', each of which has an empirically derived numerical value. Such empirically derived 'constants' must also have associated uncertainties which propagate through the functional relationship

  11. 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....

  12. No psychological distress in sportsmen aged 45 years and older after cardiovascular screening, including cardiac CT: The Measuring Athlete's Risk of Cardiovascular events (MARC) study.

    Science.gov (United States)

    Schurink, M M; Braber, T L; Prakken, N H J; Doevendans, P A F M; Backx, F J G; Grobbee, D E; Rienks, R; Nathoe, H M; Bots, M L; Velthuis, B K; Mosterd, A

    2017-04-01

    Psychological distress caused by cardiovascular pre-participation screening (PPS) may be a reason not to implement a PPS program. We assessed the psychological impact of PPS, including cardiac computed tomography (CT), in 318 asymptomatic sportsmen aged ≥45 years. Coronary artery disease (CAD) was defined as a coronary artery calcium score ≥100 Agatson units and/or ≥50% luminal stenosis on contrast-enhanced cardiac CT. Psychological impact was measured with the Impact of Event Scale (IES) (seven items) on a six-point scale (grade 0-5). A sum score ≥19 indicates clinically relevant psychological distress. A Likert scale was used to assess overall experiences and impact on sports and lifestyle. A total of 275 participants (86.5% response rate, 95% CI 83-90%) with a mean age of 54.5 ± 6.4 years completed the questionnaires, 48 (17.5%, 95% CI 13-22%) of whom had CAD. The median IES score was 1 (IQR 0-2, [0-23]). IES was slightly higher in those with CAD (mean rank 175 vs. 130, p psychological distress (IES = 23). Participants reported numerous benefits, including feeling safer exercising (58.6%, 95% CI 53-65%) and positive lifestyle changes, especially in those with CAD (17.2 vs. 52.1%, p psychological distress in older sportsmen. Psychological distress should not be a reason to forego screening in sportsmen.

  13. Simulation and measurement of complete dye sensitised solar cells: including the influence of trapping, electrolyte, oxidised dyes and light intensity on steady state and transient device behaviour.

    Science.gov (United States)

    Barnes, Piers R F; Anderson, Assaf Y; Durrant, James R; O'Regan, Brian C

    2011-04-07

    A numerical model of the dye sensitised solar cell (DSSC) is used to assess the importance of different loss pathways under various operational conditions. Based on our current understanding, the simulation describes the processes of injection, regeneration, recombination and transport of electrons, oxidised dye molecules and electrolyte within complete devices to give both time dependent and independent descriptions of performance. The results indicate that the flux of electrons lost from the nanocrystalline TiO(2) film is typically at least twice as large under conditions equivalent to 1 sun relative to dark conditions at matched TiO(2) charge concentration. This is in agreement with experimental observations (Barnes et al. Phys. Chem. Chem. Phys. [DOI: 10.1039/c0cp01855d]). The simulated difference in recombination flux is shown to be due to variation in the concentration profile of electron accepting species in the TiO(2) pores between light and dark conditions and to recombination to oxidised dyes in the light. The model is able to easily incorporate non-ideal behaviour of a cell such as the variation of open circuit potential with light intensity and non-first order recombination of conduction band electrons. The time dependent simulations, described by the multiple trapping model of electron transport and recombination, show good agreement with both small and large transient photocurrent and photovoltage measurements at open circuit, including photovoltage rise measurements. The simulation of photovoltage rise also suggests the possibility of assessing the interfacial resistance between the TiO(2) and substrate. When cells with a short diffusion length relative to film thickness were modelled, the simulated small perturbation photocurrent transients at short circuit (but not open circuit) yielded significantly higher effective diffusion coefficients than expected from the mean concentration of electrons and the electrolyte in the cell. This implies that

  14. The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Measurement and errors of crater statistics. Ph.D. Thesis

    Science.gov (United States)

    Leake, M. A.

    1982-01-01

    Planetary imagery techniques, errors in measurement or degradation assignment, and statistical formulas are presented with respect to cratering data. Base map photograph preparation, measurement of crater diameters and sampled area, and instruments used are discussed. Possible uncertainties, such as Sun angle, scale factors, degradation classification, and biases in crater recognition are discussed. The mathematical formulas used in crater statistics are presented.

  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. 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.

  17. Affinity of hemoglobin for the cytoplasmic fragment of human erythrocyte membrane band 3. Equilibrium measurements at physiological pH using matrix-bound proteins: the effects of ionic strength, deoxygenation and of 2,3-diphosphoglycerate.

    Science.gov (United States)

    Chétrite, G; Cassoly, R

    1985-10-05

    The cytoplasmic fragment of band 3 protein isolated from the human erythrocyte membrane was linked to a CNBr-activated Sepharose matrix in an attempt to measure, in batch experiments, its equilibrium binding constant with oxy- and deoxyhemoglobin at physiological pH and ionic strength values and in the presence or the absence of 2,3-diphosphoglycerate. All the experiments were done at pH 7.2, and equilibrium constants were computed on the basis of one hemoglobin tetramer bound per monomer of fragment. In 10 mM-phosphate buffer, a dissociation constant KD = 2 X 10(-4)M was measured for oxyhemoglobin and was shown to increase to 8 X 10(-4)M in the presence of 50 mM-NaCl. Association could not be demonstrated at higher salt concentrations. Diphosphoglycerate-stripped deoxyhemoglobin was shown to associate more strongly with the cytoplasmic fragment of band 3. In 10 mM-bis-Tris (pH 7.2) and in the presence of 120 mM-NaCl, a dissociation constant KD = 4 X 10(-4)M was measured. Upon addition of increasing amounts of 2,3-diphosphoglycerate, the complex formed between deoxyhemoglobin and the cytoplasmic fragment of band 3 was dissociated. On the reasonable assumption that the hemoglobin binding site present on band 3 fragment was not modified upon linking the protein to the Sepharose matrix, the results indicated that diphosphoglycerate-stripped deoxyhemoglobin or partially liganded hemoglobin tetramers in the T state could bind band 3 inside the intact human red blood cell.

  18. Assessment of a correlation between Canine Atopic Dermatitis Extent and Severity Index (CADESI-03) and selected biophysical skin measures (skin hydration, pH, and erythema intensity) in dogs with naturally occurring atopic dermatitis.

    Science.gov (United States)

    Zając, Marcin; Szczepanik, Marcin P; Wilkołek, Piotr M; Adamek, Łukasz R; Pomorski, Zbigniew J H; Sitkowski, Wiesław; Gołyński, Marcin

    2015-04-01

    Atopic dermatitis is a common allergic skin disease in dogs. The aim of this study was to examine the possibility of a correlation between biophysical skin variables: skin hydration (SH), skin pH, and erythema intensity measured in 10 different body regions and both total Canine Atopic Dermatitis Extent and Severity Index (CADESI-03) and CADESI measured in a given region (CADESI L). The study was conducted using 33 dogs with atopic dermatitis. The assessment of the biophysical variables was done in 10 body regions: the lumbar region, right axillary fossa, right inguinal region, ventral abdominal region, right lateral thorax region, internal surface of the auricle, interdigital region of right forelimb, cheek, bridge of nose, and lateral site of antebrachum. Positive correlations were found between SH and CADESI L for the following regions: the inguinal region (r = 0.73) and the interdigital region (r = 0.82), as well as between total CADESI and SH on digital region (r = 0.52). Also, positive correlations were reported for skin pH and CADESI L in the lumbar region (r = 0.57), the right lateral thorax region (r = 0.40), and the lateral antebrachum (r = 0.35). Positive correlations were found in the interdigital region between erythema intensity and the total CADESI-03 (r = 0.60) as well as the CADESI L (r = 0.7). The results obtained suggest that it may be possible to use skin hydration, pH, and erythema intensity to assess the severity of skin lesion but positive correlation was only found in < 13.3% of possible correlations and usage of these measures in dogs is limited.

  19. 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.

  20. The intercrater plains of Mercury and the Moon: Their nature, origin and role in terrestrial planet evolution. Areal measurement of Mercury's first quadrant. Ph.D. Thesis

    Science.gov (United States)

    Leake, M. A.

    1982-01-01

    Various linear and areal measurements of Mercury's first quadrant which were used in geological map preparation, map analysis, and statistical surveys of crater densities are discussed. Accuracy of each method rests on the determination of the scale of the photograph, i.e., the conversion factor between distances on the planet (in km) and distances on the photograph (in cm). Measurement errors arise due to uncertainty in Mercury's radius, poor resolution, poor coverage, high Sun angle illumination in the limb regions, planetary curvature, limited precision in measuring instruments, and inaccuracies in the printed map scales. Estimates are given for these errors.

  1. Saturação de oxigênio fetal medida pela oximetria de pulso durante o trabalho de parto: relações com o ph da artéria umbilical Fetal oxygen saturation measured by pulse oximetry during labor: relation to umbilical artery pH

    Directory of Open Access Journals (Sweden)

    Edson Nunes de Morais

    1999-04-01

    Full Text Available Objetivos: estudar os níveis de saturação de oxigênio fetal (SpO2 durante o trabalho de parto pela técnica da oximetria de pulso e sua relação com o pH da artéria umbilical (AU. Pacientes e Métodos: a SpO2 fetal foi medida durante o parto por meio da técnica da oximetria de pulso em 50 casos. Comparou-se a média dos valores de SpO2 entre os dois períodos do trabalho de parto, sendo o primeiro subdividido em fases, segundo a dilatação cervical ( ou = 7,20 e ou = 30,0%. Resultados: as médias da SpO2 fetal no primeiro período do parto foram de 53,0 ± 7,3% e 44,2 ± 6,8%, e no segundo 46,8 ± 7,7% e 38,4 ± 7,1% (pH da AU > ou = 7,20 e ou = 7,20 foram de 55,1 ± 5,1% (Purpose: to study fetal oxygen saturation (SpO2 levels during labor by continuous pulse oximetry tecnique, and its relation to umbilical artery (UA pH. Patients and Methods: fetal SpO2 levels were measured during labor by the pulse oximetry technique in 50 subjects. Average values of SpO2 were compared between the first and second stage of labor, with the first stage further subdivided into phases, according to cervical dilatation of ( or = 7.20 and or = 30.0% was considered normal. Results: fetal SpO2 averages during the first stage were 53.0 ± 7.3% and 44.2 ± 6.8% (UA pH > or = 7.20 and or = 7.20 were 55.1 ± 5.1% (<=4 cm, 52.3 ± 4.6% (5-7 cm and 51.5 ± 7.2% (8-9 cm; for UA pH <7.20, the fetal SpO2 averages were 46.3 ± 5.1% (<=4 cm, 43.6 ± 6.7% (5-7 cm and 42.8 ± 5.8% (8-9 cm. Considering the UA pH, these differences were statistically significant (p<0.01. Conclusion: a significant decrease of oxygen saturation values was observed during labor when fetal pulse oximetry was used.

  2. Using patient reported outcome measures in health services: A qualitative study on including people with low literacy skills and learning disabilities

    NARCIS (Netherlands)

    Jahagirdar, D.; Kroll, T.; Ritchie, K.; Wyke, S.

    2012-01-01

    ABSTRACT: BACKGROUND: Patient reported outcome measures (PROMs) are self-report measures of health status increasingly promoted for use in healthcare quality improvement. However people with low literacy skills or learning disabilities may find PROMs hard to complete. Our study investigated

  3. Modelling lamb carcase pH and temperature decline parameters: relationship to shear force and abattoir variation.

    Science.gov (United States)

    Hopkins, David L; Holman, Benjamin W B; van de Ven, Remy J

    2015-02-01

    Carcase pH and temperature decline rates influence lamb tenderness; therefore pH decline parameters are beneficial when modelling tenderness. These include pH at temperature 18 °C (pH@Temp18), temperature when pH is 6 (Temp@pH6), and pH at 24 h post-mortem (pH24). This study aimed to establish a relationship between shear force (SF) as a proxy for tenderness and carcase pH decline parameters estimated using both linear and spline estimation models for the m. longissimus lumborum (LL). The study also compared abattoirs regarding their achievement of ideal pH decline, indicative of optimal tenderness. Based on SF measurements of LL and m. semimembranosus collected as part of the Information Nucleus slaughter programme (CRC for Sheep Industry Innovation) this study found significant relationships between tenderness and pH24LL, consistent across the meat cuts and ageing periods examined. Achievement of ideal pH decline was shown not to have significantly differed across abattoirs, although rates of pH decline varied significantly across years within abattoirs.

  4. Micro Electrochemical pH Sensor Applicable for Real-Time Ratiometric Monitoring of pH Values in Rat Brains.

    Science.gov (United States)

    Zhou, Jie; Zhang, Limin; Tian, Yang

    2016-02-16

    To develop in vivo monitoring meter for pH measurements is still the bottleneck for understanding the role of pH plays in the brain diseases. In this work, a selective and sensitive electrochemical pH meter was developed for real-time ratiometric monitoring of pH in different regions of rat brains upon ischemia. First, 1,2-naphthoquinone (1,2-NQ) was employed and optimized as a selective pH recognition element to establish a 2H(+)/2e(-) approach over a wide range of pH from 5.8 to 8.0. The pH meter demonstrated remarkable selectivity toward pH detection against metal ions, amino acids, reactive oxygen species, and other biological species in the brain. Meanwhile, an inner reference, 6-(ferrocenyl)hexanethiol (FcHT), was selected as a built-in correction to avoid the environmental effect through coimmobilization with 1,2-NQ. In addition, three-dimensional gold nanoleaves were electrodeposited onto the electrode surface to amplify the signal by ∼4.0-fold and the measurement was achieved down to 0.07 pH. Finally, combined with the microelectrode technique, the microelectrochemical pH meter was directly implanted into brain regions including the striatum, hippocampus, and cortex and successfully applied in real-time monitoring of pH values in these regions of brain followed by global cerebral ischemia. The results demonstrated that pH values were estimated to 7.21 ± 0.05, 7.13 ± 0.09, and 7.27 ± 0.06 in the striatum, hippocampus, and cortex in the rat brains, respectively, in normal conditions. However, pH decreased to 6.75 ± 0.07 and 6.52 ± 0.03 in the striatum and hippocampus, upon global cerebral ischemia, while a negligible pH change was obtained in the cortex.

  5. Measure Guideline: Summary of Interior Ducts in New Construction, Including an Efficient, Affordable Method to Install Fur-Down Interior Ducts

    Energy Technology Data Exchange (ETDEWEB)

    Beal, D. [BA-PIRC, Cocoa, FL (United States); McIlvaine, J. [BA-PIRC, Cocoa, FL (United States); Fonorow, K. [BA-PIRC, Cocoa, FL (United States); Martin, E. [BA-PIRC, Cocoa, FL (United States)

    2011-11-01

    This document illustrates guidelines for the efficient installation of interior duct systems in new housing, including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces.

  6. Intracapillary HbO2 saturations in murine tumours and human tumour xenografts measured by cryospectrophotometry: relationship to tumour volume, tumour pH and fraction of radiobiologically hypoxic cells.

    Science.gov (United States)

    Rofstad, E K; Fenton, B M; Sutherland, R M

    1988-05-01

    Frequency distributions for intracapillary HbO2 saturation were determined for two murine tumour lines (KHT, RIF-1) and two human ovarian carcinoma xenograft lines (MLS, OWI) using a cryospectrophotometric method. The aim was to search for possible relationships between HbO2 saturation status and tumour volume, tumour pH and fraction of radiobiologically hypoxic cells. Tumour pH was measured by 31P NMR spectroscopy. Hypoxic fractions were determined from cell survival curves for tumours irradiated in vivo and assayed in vitro. Tumours in the volume range 100-4000 mm3 were studied and the majority of the vessels were found to have HbO2 saturations below 10%. The volume-dependence of the HbO2 frequency distributions differed significantly among the four tumour lines; HbO2 saturation status decreased with increasing tumour volume for the KHT, RIF-1 and MLS lines and was independent of tumour volume for the OWI line. The data indicated that the rate of decrease in HbO2 saturation status during tumour growth was related to the rate of development of necrosis. The volume-dependence of tumour pH was very similar to that of the HbO2 saturation status for all tumour lines. Significant correlations were therefore found between HbO2 saturation status and tumour pH, both within tumour lines and across the four tumour lines, reflecting that the volume-dependence of both parameters probably was a compulsory consequence of reduced oxygen supply conditions during tumour growth. Hypoxic fraction increased during tumour growth for the KHT, RIF-1 and MLS lines and was volume-independent for the OWI line, suggesting a relationship between HbO2 saturation status and hypoxic fraction within tumour lines. However, there was no correlation between these two parameters across the four tumour lines, indicating that the hypoxic fraction of a tumour is not determined only by the oxygen supply conditions; other parameters may also be important, e.g. oxygen diffusivity, rate of oxygen

  7. Application of time-correlated single photon counting and stroboscopic detection methods with an evanescent-wave fibre-optic sensor for fluorescence-lifetime-based pH measurements

    International Nuclear Information System (INIS)

    Henning, Paul E; Geissinger, Peter

    2012-01-01

    Quasi-distributed optical fibre sensor arrays containing luminescent sensor molecules can be read out spatially resolved utilizing optical time-of-flight detection (OTOFD) methods, which employ pulsed laser interrogation of the luminosensors and time-resolved detection of the sensor signals. In many cases, sensing is based on a change in sensor luminescence intensity; however, sensing based on luminescence lifetime changes is preferable because it reduces the need for field calibration. Because in OTOFD detection is time-resolved, luminescence-lifetime information is already available through the signal pulses, although in practise applications were restricted to sensors with long luminescence lifetimes (hundreds of ns). To implement lifetime-based sensing in crossed-optical-fibre-sensor arrays for sensor molecules with lifetimes less than 10 ns, two time-domain methods, time-correlated single photon counting and stroboscopic detection, were used to record the pH-dependent emission of a fluorescein derivative covalently attached to a highly-porous polymer. A two-term nonexponential decay function yielded both a good fit for experimental lifetime data during reconvolution and a pH response that matches Henderson–Hasselbalch behaviour, yielding a sensor accuracy of 0.02 pH units. Moreover, strong agreement was obtained for the two lifetime determination methods and with intensity-based measurements taken previously. (paper)

  8. Cerebral NMR spectroscopy to study intracellular space in vivo: methodological development for diffusion weighted spectroscopy at short time scale and for pH measurement using 31P detection

    International Nuclear Information System (INIS)

    Marchadour, Charlotte

    2013-01-01

    NMR spectroscopy is a unique modality to evaluate intracellular environment in vivo. Indeed observed molecules are specifically intracellular and generally have a biochemistry role and a specific cellular compartmentation. That could be a useful tool to understand cell functioning in their environment. My thesis work consisted in development of new sequence in both diffusion and phosphorus NMR spectroscopy.My first study was to develop a diffusion-weighted spectroscopy at ultra-short diffusion time to look at the anomalous diffusion in the rat brain. ADC evolution as a function of time shows that brain metabolites motion is mainly due to random diffusion and that active transport (if exist) are negligible. Data modeling evidences that diffusion at short diffusion time is sensitive to cytoplasm viscosity and short scale crowding. In collaboration with the pharmaceutical company, this technique was chosen to follow up transgenic mice (rTg4510), model of tau pathology. Preliminary results show significant differences of ADC at an early stage of neuro-degenerescence (3 and 6 months).Phosphorus spectroscopy allows observation of metabolites directly implicated in energetic processes. During this thesis, localization sequences were developed to measure intracellular pH in the primate striatum. These sequences are supposed to be used to evaluate the potential of pH as a bio-marker of neuro-degenerescence in a phenotypic model of the Huntington disease in the non-human primate. (author) [fr

  9. Evaluation of the dependence of CEST-EPI measurement on repetition time, RF irradiation duty cycle and imaging flip angle for enhanced pH sensitivity

    International Nuclear Information System (INIS)

    Sun, Phillip Zhe; Lu Jie; Wu Yin; Xiao Gang; Wu Renhua

    2013-01-01

    Chemical exchange saturation transfer (CEST) is a magnetic resonance imaging (MRI) contrast mechanism that can detect dilute CEST agents and microenvironmental properties, with a host of promising applications. Experimental measurement of the CEST effect is complex, and depends on not only CEST agent concentration and exchange rate, but also experimental parameters such as RF irradiation amplitude and scheme. Although echo planar imaging (EPI) has been increasingly used for CEST MRI, the relationship between CEST effect and repetition time (TR), RF irradiation duty cycle (DC) and EPI flip angle (α) has not been fully evaluated and optimized to enhance CEST MRI sensitivity. In addition, our study evaluated gradient echo CEST-EPI by quantifying the CEST effect and its signal-to-noise ratio per unit time (SNR put ) as functions of TR, DC and α. We found that CEST effect increased with TR and DC but decreased with α. Importantly, we found that SNR put peaked at intermediate TRs of about twice the T 1 and α, at approximately 75°, and increased with RF DC. The simulation results were validated using a dual-pH creatine-gel CEST phantom. In summary, our study provides a useful framework for optimizing CEST MRI experiments. (note)

  10. 13 CFR 123.402 - Can your business include its relocation as a mitigation measure in an application for a pre...

    Science.gov (United States)

    2010-01-01

    ... participating in the Pre-Disaster Mitigation Program and SFHAs or visit the FEMA Web site at http://www.fema.gov. ... relocation as a mitigation measure in an application for a pre-disaster mitigation loan? 123.402 Section 123.402 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION DISASTER LOAN PROGRAM Pre-Disaster...

  11. 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)

  12. No psychological distress in sportsmen aged 45 years and older after cardiovascular screening, including cardiac CT : The Measuring Athlete's Risk of Cardiovascular events (MARC) study

    NARCIS (Netherlands)

    Schurink, M. M.; Braber, T. L.; Prakken, N. H. J.; Doevendans, P. A. F. M.; Backx, F. J. G.; Grobbee, D. E.; Rienks, R.; Nathoe, H. M.; Bots, M. L.; Velthuis, B. K.; Mosterd, A.

    Background Psychological distress caused by cardiovascular pre-participation screening (PPS) may be a reason not to implement a PPS program. We assessed the psychological impact of PPS, including cardiac computed tomography (CT), in 318 asymptomatic sportsmen aged >= 45 years. Methods Coronary

  13. No psychological distress in sportsmen aged 45 years and older after cardiovascular screening, including cardiac CT : The Measuring Athlete’s Risk of Cardiovascular events (MARC) study

    NARCIS (Netherlands)

    Schurink, M. M.; Braber, T. L.; Prakken, N. H J; Doevendans, P. A F M; Backx, F. J G; Grobbee, D. E.; Rienks, R.; Nathoe, H. M.; Bots, M. L.; Velthuis, B. K.; Mosterd, A.

    2017-01-01

    Background Psychological distress caused by cardiovascular pre-participation screening (PPS) may be a reason not to implement a PPS program. We assessed the psychological impact of PPS, including cardiac computed tomography (CT), in 318 asymptomatic sportsmen aged ≥45 years. Methods Coronary artery

  14. Subjective and objective measurement of the intelligibility of synthesized speech impaired by the very low bit rate STANAG 4591 codec including packet loss

    NARCIS (Netherlands)

    Počta, P.; Beerends, J.G.

    2017-01-01

    This paper deals with the intelligibility of speech coded by the STANAG 4591 standard codec, including packet loss, using synthesized speech input. Both subjective and objective assessments are used. It is shown that this codec significantly degrades intelligibility when compared to a standard

  15. Measurement of the structure functions F2 and xF3 and comparison with QCD predictions including kinematical and dynamical higher twist effects

    International Nuclear Information System (INIS)

    Varvell, K.; Wells, J.; Sansum, R.A.; Bullock, F.W.; Fitch, P.J.; Armenise, N.; Calicchio, M.; Erriquez, O.; Natali, S.; Nuzzo, S.; Ruggieri, F.; Baton, J.P.; Gerbier, G.; Kasper, P.; Kochowski, C.; Neveu, M.; Brisson, V.; Petiau, P.; Vallee, C.; Clayton, E.F.; Iaselli, G.; Mobayyen, M.M.; Petrides, A.; Jones, G.T.; Middleton, R.P.; O'Neale, S.W.; Mermikides, M.; Simopoulou, E.; Vayaki, A.

    1987-01-01

    The isoscalar nucleon structure functions F 2 (x,Q 2 ) and xF 3 (x,Q 2 ) are measured in the range 0 2 2 , 1.7 2 2 , x 2 values, it is found that a low Λsub(anti Manti S) value in the neighbourhood of 100 MeV describes the data adequately and that the contribution of dynamical higher twist effects is small and negative. (orig.)

  16. Yogurt made from milk heated at different pH values.

    Science.gov (United States)

    Ozcan, Tulay; Horne, David S; Lucey, John A

    2015-10-01

    Milk for yogurt manufacture is subjected to high heat treatment to denature whey proteins. Low milk pH values (≤ 6.5) at heating result in most denatured whey proteins becoming associated with casein micelles, whereas high milk pH values (≥ 7.0) at heating result in the formation of mostly soluble (nonmicellar) denatured whey protein complexes. There are conflicting reports on the relative importance of soluble and casein-bound whey protein aggregates on the properties of acid gels. Prior studies investigating the effect of pH of milk at heating used model gels in which milk was acidified by glucono-δ-lactone; in this study, we prepared yogurt gels using commercial starter cultures. Model acid gels can have very different texture and physical properties from those made by fermentation with starter cultures. In this study, we investigated the effects of different pH values of milk at heating on the rheological, light backscatter, and microstructural properties of yogurt gels. Reconstituted skim milk was adjusted to pH values 6.2, 6.7, and 7.2 and heated at 85°C for 30 min. A portion of the heated milk samples was readjusted back to pH 6.7 after heating. Milks were inoculated with 3% (wt/wt) yogurt starter culture and incubated at 40°C until pH 4.6. Gel formation was monitored using dynamic oscillatory rheology, and parameters measured included the storage modulus (G') and loss tangent (LT) values. Light-backscattering properties, such as the backscatter ratio (R) and the first derivative of light backscatter ratio (R'), were also monitored during fermentation. Fluorescence microscopy was used to observe gel microstructure. The G' values at pH 4.6 were highest in gels made from milk heated at pH 6.7 and lowest in milk heated at pH 6.2, with or without pH adjustment after heating. The G' values at pH 4.6 were lower in samples after adjustment back to pH 6.7 after heating. No maximum in the LT parameter was observed during gelation for yogurts made from milk

  17. Salivary pH as a marker of plasma adiponectin concentrations in Women.

    Science.gov (United States)

    Tremblay, Monique; Loucif, Yacine; Methot, Julie; Brisson, Diane; Gaudet, Daniel

    2012-02-03

    Plasma adiponectin is a significant correlate of the pro-inflammatory cardiometabolic risk profile associated with obesity and type 2 diabetes. Salivary pH is influenced by several cardiometabolic risk components such as inflammation, oxidation and numerous oral and systemic health modulators, including the menopausal status. This study aimed to assess the association between plasma adiponectin concentrations and salivary pH in women according to the menopausal status. Unstimulated saliva collection was performed in 151 Caucasian women of French-Canadian origin (53 premenopausal women (PMW) and 98 menopausal women (MW)). Student's t test, ANOVA and linear regression models were used to assess the association between plasma adiponectin concentrations and salivary pH. Plasma adiponectin levels increased as a function of salivary pH in the whole sample and among MW (r = 0.29 and r = 0.36, p salivary pH (R2) was 10.8% (p salivary pH quartiles (p = 0.005). These results suggest that salivary pH is a significant correlate of plasma adiponectin levels in women. With the increasing prevalence of type 2 diabetes and obesity, new technologies should be developed to more easily monitor health status, disease onset and progression. Salivary pH, a simple, inexpensive and non-invasive measure, could be a very promising avenue.

  18. Relieving Dry Mouth: Varying Levels of pH Found in Bottled Water.

    Science.gov (United States)

    Fisher, Bailey Jean; Spencer, Angela; Haywood, Van; Konchady, Gayathri

    2017-07-01

    It is estimated that 30% of people older than 60 years suffer from hyposalivation or dry mouth. Drinking water frequently has been recommended as a safe, non-pharmacologic way to combat hyposalivation. The saliva in patients with dry mouth is acidic. Beverages consumed daily may have an erosive potential on teeth. The pH and the mineral content of the beverage determine its erosive potential. An acidic beverage, therefore, may have harmful effects on mineralized tooth structures, causing erosion of enamel, dentin, and cementum. Because bottled water is both convenient and easily available, the authors tested the pH of eight common brands of bottled water. (One brand included two different bottle types, for a total of nine bottled waters tested.) To standardize the pH electrode, pH buffers of 4.7 and 10 were used. The pH was measured using the Denver Instruments basic pH meter. Six recordings were used for each brand and then averaged to report the pH. Two of the bottled water samples tested were below the critical level of 5.2 pH to 5.5 pH, the level at which erosion of enamel occurs. Six of the samples tested were below the critical pH of 6.8, at which erosion of root dentin occurs. The authors conclude that both patients and clinicians incorrectly presume bottled water to be innocuous. Clinicians should be cognizant of the erosive potential of different brands of bottled water to both educate patients and to recommend water with neutral or alkaline pH for patients with symptoms of dry mouth to prevent further deterioration and demineralization of tooth structure.

  19. Determination of potassium in several plants and study of potassium transfer to different beverages, including tequila, by measurement of 40K

    International Nuclear Information System (INIS)

    Navarrete, J.M.; Muller, G.; Cabrera, L.; Martinez, T.

    2006-01-01

    Measurement of 40 K was used for determination of potassium concentrations in leaves of agave and maguey cactus leaves, and coffee beans of various origins. The procedure was also used to study potassium transfer to tequila (alcoholic drink made of agave cactus), and the cactus and coffee infusions using 40 K as a natural radioactive tracer. Counting of 40 K in Marinelli containers with the aid of a low background NaI(Tl) scintillation detection system for 12-24 hours was employed. The method appeared to be simple and suitable for determination of potassium concentrations in large samples, which eliminates homogeneity problems. (author)

  20. Automated analysis of off-line measured gamma-spectra using UniSampo gamma-ray spectrum analysis software including criterias for alarming systems

    International Nuclear Information System (INIS)

    Nikkinen, M.T.

    2005-01-01

    In many laboratories the number of measured routine gamma-spectra can be significant and the labour work to review all the data is time consuming and expensive task. In many cases the routine sample does not normally contain radiation above a detectable level, and still the review of the spectra has to be performed. By introducing simple rules for emerging conditions, the review work can be significantly reduced. In one case the need to review the environmental measurement spectra was reduced to less than 1% compared to the original need, which in turn made the review personnel available for more useful functions. Using the UniSampo analysis system, the analysis results of spectra that are causing alarming conditions can be transmitted via e-mail to any address. Some systems are even equipped with the capability to forward these results to hand-portable telephones or pagers. This is a very practical solution for automated environmental monitoring, when the sample spectra are collected automatically and transmitted to central computer for further analysis. Set up of an automatic analysis system, rules for the emerging conditions, technical solutions for an automated alarming system and a generic hypothesis test for the alarming system developed for UniSampo analysis software are described. (author)

  1. Measurement of the structure functions F 2 and xF 3 and comparison with QCD predictions including kinematical and dynamical higher twist effects

    Science.gov (United States)

    Varvell, K.; Cooper-Sarkar, A. M.; Parker, M. A.; Sansum, R. A.; Aderholz, M.; Armenise, N.; Baton, J. P.; Bullock, F. W.; Berggren, M.; Bertrand, D.; Brisson, V.; Burkot, W.; Calcchio, M.; Claytoh, E. F.; Coghen, T.; Erriquez, O.; Fitch, P. J.; Gerbier, G.; Guy, J.; Hulth, P. O.; Iaselli, G.; Jones, G. T.; Kasper, P.; Klein, H.; Kochowski, C.; Marage, P.; Mermikides, M.; Middleton, R. P.; Morrison, D. R. O.; Mobayyen, M. M.; Natali, S.; Neveu, M.; Nuzzo, S.; O'Neale, S. W.; Petiau, P.; Petrides, A.; Ruggieri, F.; Sacton, J.; Simopoulou, E.; Vallee, C.; Vayaki, A.; Venus, W. A.; Wachsmuth, H.; Wells, J.; Wittek, W.

    1987-03-01

    The isoscalar nucleon structure functions F 2( x, Q 2) and xF 3( x, Q 2) are measured in the range 0< Q 2<64 GeV2, 1.7< W 2<250 GeV2, x<0.7 using ν andbar v interactions on neon in BEBC. The data are used to evaluate possible higher twist contributions and to determine their impact on the evaluation of the QCD parameter Λ. In contrast to previous analyses reaching to such low W 2 values, it is found that a lowΛ _{overline {MS} } value in the neighbourhood of 100 MeV describes the data adequately and that the contribution of dynamical higher twist effects is small and negative.

  2. Measure Guideline: Summary of Interior Ducts in New Construction, Including an Efficient, Affordable Method to Install Fur-Down Interior Ducts

    Energy Technology Data Exchange (ETDEWEB)

    Beal, D.; McIlvaine , J.; Fonorow, K.; Martin, E.

    2011-11-01

    This document illustrates guidelines for the efficient installation of interior duct systems in new housing, including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. This document illustrates guidelines for the efficient installation of interior duct systems in new housing. Interior ducts result from bringing the duct work inside a home's thermal and air barrier. Architects, designers, builders, and new home buyers should thoroughly investigate any opportunity for energy savings that is as easy to implement during construction, such as the opportunity to construct interior duct work. In addition to enhanced energy efficiency, interior ductwork results in other important advantages, such as improved indoor air quality, increased system durability and increased homeowner comfort. While the advantages of well-designed and constructed interior duct systems are recognized, the implementation of this approach has not gained a significant market acceptance. This guideline describes a variety of methods to create interior ducts including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. As communication of the intent of an interior duct system, and collaboration on its construction are paramount to success, this guideline details the critical design, planning, construction, inspection, and verification steps that must be taken. Involved in this process are individuals from the design team; sales/marketing team; and mechanical, insulation, plumbing, electrical, framing, drywall and solar contractors.

  3. Advanced Biotelemetry Systems for Space Life Sciences: PH Telemetry

    Science.gov (United States)

    Hines, John W.; Somps, Chris; Ricks, Robert; Kim, Lynn; Connolly, John P. (Technical Monitor)

    1995-01-01

    The SENSORS 2000! (S2K!) program at NASA's Ames Research Center is currently developing a biotelemetry system for monitoring pH and temperature in unrestrained subjects. This activity is part of a broader scope effort to provide an Advanced Biotelemetry System (ABTS) for use in future space life sciences research. Many anticipated research endeavors will require biomedical and biochemical sensors and related instrumentation to make continuous inflight measurements in a variable-gravity environment. Since crew time is limited, automated data acquisition, data processing, data storage, and subject health monitoring are required. An automated biochemical and physiological data acquisition system based on non invasive or implantable biotelemetry technology will meet these requirements. The ABTS will ultimately acquire a variety of physiological measurands including temperature, biopotentials (e.g. ECG, EEG, EMG, EOG), blood pressure, flow and dimensions, as well as chemical and biological parameters including pH. Development activities are planned in evolutionary, leveraged steps. Near-term activities include 1) development of a dual channel pH/temperature telemetry system, and 2) development of a low bandwidth, 4-channel telemetry system, that measures temperature, heart rate, pressure, and pH. This abstract describes the pH/temperature telemeter.

  4. pH sensitive quantum dot-anthraquinone nanoconjugates

    Science.gov (United States)

    Ruedas-Rama, Maria Jose; Hall, Elizabeth A. H.

    2014-05-01

    Semiconductor quantum dots (QDs) have been shown to be highly sensitive to electron or charge transfer processes, which may alter their optical properties. This feature can be exploited for different sensing applications. Here, we demonstrate that QD-anthraquinone conjugates can function as electron transfer-based pH nanosensors. The attachment of the anthraquinones on the surface of QDs results in the reduction of electron hole recombination, and therefore a quenching of the photoluminescence intensity. For some anthraquinone derivatives tested, the quenching mechanism is simply caused by an electron transfer process from QDs to the anthraquinone, functioning as an electron acceptor. For others, electron transfer and energy transfer (FRET) processes were found. A detailed analysis of the quenching processes for CdSe/ZnS QD of two different sizes is presented. The photoluminescence quenching phenomenon of QDs is consistent with the pH sensitive anthraquinone redox chemistry. The resultant family of pH nanosensors shows pKa ranging ˜5-8, being ideal for applications of pH determination in physiological samples like blood or serum, for intracellular pH determination, and for more acidic cellular compartments such as endosomes and lysosomes. The nanosensors showed high selectivity towards many metal cations, including the most physiologically important cations which exist at high concentration in living cells. The reversibility of the proposed systems was also demonstrated. The nanosensors were applied in the determination of pH in samples mimicking the intracellular environment. Finally, the possibility of incorporating a reference QD to achieve quantitative ratiometric measurements was investigated.

  5. pH sensitive quantum dot–anthraquinone nanoconjugates

    International Nuclear Information System (INIS)

    Ruedas-Rama, Maria Jose; Hall, Elizabeth A H

    2014-01-01

    Semiconductor quantum dots (QDs) have been shown to be highly sensitive to electron or charge transfer processes, which may alter their optical properties. This feature can be exploited for different sensing applications. Here, we demonstrate that QD-anthraquinone conjugates can function as electron transfer-based pH nanosensors. The attachment of the anthraquinones on the surface of QDs results in the reduction of electron hole recombination, and therefore a quenching of the photoluminescence intensity. For some anthraquinone derivatives tested, the quenching mechanism is simply caused by an electron transfer process from QDs to the anthraquinone, functioning as an electron acceptor. For others, electron transfer and energy transfer (FRET) processes were found. A detailed analysis of the quenching processes for CdSe/ZnS QD of two different sizes is presented. The photoluminescence quenching phenomenon of QDs is consistent with the pH sensitive anthraquinone redox chemistry. The resultant family of pH nanosensors shows pK a ranging ∼5–8, being ideal for applications of pH determination in physiological samples like blood or serum, for intracellular pH determination, and for more acidic cellular compartments such as endosomes and lysosomes. The nanosensors showed high selectivity towards many metal cations, including the most physiologically important cations which exist at high concentration in living cells. The reversibility of the proposed systems was also demonstrated. The nanosensors were applied in the determination of pH in samples mimicking the intracellular environment. Finally, the possibility of incorporating a reference QD to achieve quantitative ratiometric measurements was investigated

  6. 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.

  7. Persistence of long term isokinetic strength deficits in subjects with lateral ankle sprain as measured with a protocol including maximal preloading.

    Science.gov (United States)

    Perron, Marc; Moffet, Hélène; Nadeau, Sylvie; Hébert, Luc J; Belzile, Sylvain

    2014-12-01

    The assessment of muscle function is a cornerstone in the management of subjects who have sustained a lateral ankle sprain. The ankle range of motion being relatively small, the use of preloading allows to measure maximal strength throughout the whole amplitude and therefore to better characterize ankle muscles weaknesses. This study aimed to assess muscle strength of the injured and uninjured ankles in subjects with a lateral ankle sprain, to document the timeline of strength recovery, and to determine the influence of sprain grade on strength loss. Maximal torque of the periarticular muscles of the ankle in a concentric mode using a protocol with maximal preloading was tested in 32 male soldiers at 8 weeks and 6 months post-injury. The evertor muscles of the injured ankles were weaker than the uninjured ones at 8 weeks and 6 months post-injury (Pankles at 8 weeks (P=0.0014, effect size=0.52-0.58) while at 6 months, only the subjects with a grade II sprain displayed such weaknesses (Pankle sprain in very active individuals. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Effectiveness of interventions on physical activity in overweight or obese children: a systematic review and meta-analysis including studies with objectively measured outcomes.

    Science.gov (United States)

    Nooijen, C F J; Galanti, M R; Engström, K; Möller, J; Forsell, Y

    2017-02-01

    There is no consensus on interventions to be recommended in order to promote physical activity among overweight or obese children. The objective of this review was to assess the effects on objectively measured physical activity, of interventions promoting physical activity among overweight or obese children or adolescents, compared to no intervention or to interventions without a physical activity component. Publications up to December 2015 were located through electronic searches for randomized controlled trials resulting in inclusion of 33 studies. Standardized mean differences from baseline to post-intervention and to long-term follow-up were determined for intervention and control groups and meta-analysed using random effects models. The meta-analysis showed that interventions had no effect on total physical activity of overweight and obese children, neither directly post-intervention (-0.02 [-0.15, 0.11]) nor at long-term follow-up (0.07 [-0.27, 0.40]). Separate analyses by typology of intervention (with or without physical fitness, behavioural or environmental components) showed similar results (no effect). In conclusion, there is no evidence that currently available interventions are able to increase physical activity among overweight or obese children. This questions the contribution of physical activity to the treatment of overweight and obesity in children in the studied interventions and calls for other treatment strategies. © 2017 World Obesity Federation.

  9. Investigation of optimized experimental parameters including laser wavelength for boron measurement in photovoltaic grade silicon using laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Darwiche, S.; Benmansour, M.; Eliezer, N.; Morvan, D.

    2010-01-01

    The quantification of boron and other impurities in photovoltaic grade silicon was investigated using the LIBS technique with attention to the laser wavelength employed, temporal parameters, and the nature of the ambient gas. The laser wavelength was found to have a moderate effect on the performance of the process, while the type of purge gas and temporal parameters had a strong effect on the signal-to-background ratio (SBR) of the boron spectral emission, which was used to determine the boron concentration in silicon. The three parameters are not independent, meaning that for each different purge gas, different optimal temporal parameters are observed. Electron density was also calculated from Stark broadening of the 390.5 nm silicon emission line in order to better understand the different performances observed when using different gases and gating parameters. Calibration curves were made for boron measurement in silicon using certified standards with different purge gases while using the temporal parameters which had been optimized for that gas. By comparing the calibration curves, it was determined that argon is superior to helium or air for use as the analysis chamber purge gas with an UV laser.

  10. LHCb: Measurements of the relative branching fractions of the decay channel $B^{\\pm}\\to p \\bar{p} K^{\\pm}$ including charmonium contributions at LHCb

    CERN Multimedia

    Cardinale, Roberta

    2011-01-01

    The study of the $B^{\\pm}\\to p \\bar{p} K^{\\pm}$ decay channel at LHCb is of great interest since it gives the possibility to study different aspects of the Standard Model and possibly Beyond Standard Model physics. A measurement of the direct CP asymmetry can be performed. Moreover intermediate states such as charmonium and "charmonium-like" resonances in the $p \\bar{p}$ final state can be observed and studied along with their characteristics. A multivariate selection has been implemented to select the interesting events using kinematic and topological variables and the particle identification information using the Ring Imaging Cherenkov detectors. The selection has a high signal efficiency and high background rejection capability. The ratios of the branching fractions of the $B^{\\pm}\\to p \\bar{p} K^{\\pm}$ decay channel, of the charmless component with $M_{p \\bar{p}} < 2.85 \\,{\\rm GeV/}c^{2}$ and of the charmonium contribution $\\eta_{c}$, ${\\mathcal B} (B^{\\pm}\\to \\eta_{c} K^{\\pm})\\times {\\mathcal B} (\\eta...

  11. 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...

  12. Design of an optically stable pH sensor based on immobilization of Giemsa on triacetylcellulose membrane.

    Science.gov (United States)

    Khodadoust, Saeid; Kouri, Narges Cham; Talebiyanpoor, Mohammad Sharif; Deris, Jamile; Pebdani, Arezou Amiri

    2015-12-01

    In this work a simple, inexpensive, and sensitive optical sensor based on triacetylcellulose membrane as solid support was developed by using immobilization of Giemsa indicator for pH measurement. In this method, the influence variables on the membrane performance including pH concentration of indicator, response time, ionic strength, and reversibility were investigated. At optimum values of all variables the response of optical pH sensor is linear in the pH range of 3.0-12.0. This optical sensor was produced through simultaneous binding of the Giemsa on the activated triacetylcellulose membrane which responded to the pH changes in a broader linear range within less than 2.0 min and suitable reproducibility (RSDsensor was stable after 6 months of storage in the water/ethanol (50:50, v/v) solution without any measurable divergence in response properties (less than 5% RSD). Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Rheumatoid factor testing in Spanish primary care: A population-based cohort study including 4.8 million subjects and almost half a million measurements.

    Science.gov (United States)

    Morsley, Klara; Miller, Anne; Luqmani, Raashid; Fina-Aviles, Francesc; Javaid, Muhammad Kassim; Edwards, Christopher J; Pinedo-Villanueva, Rafael; Medina, Manuel; Calero, Sebastian; Cooper, Cyrus; Arden, Nigel; Prieto-Alhambra, Daniel

    2018-02-26

    Rheumatoid factor (RF) testing is used in primary care in the diagnosis of rheumatoid arthritis (RA); however a positive RF may occur without RA. Incorrect use of RF testing may lead to increased costs and delayed diagnoses. The aim was to assess the performance of RF as a test for RA and to estimate the costs associated with its use in a primary care setting. A retrospective cohort study using the Information System for the Development of Research in Primary Care database (contains primary care records and laboratory results of >80% of the Catalonian population, Spain). Participants were patients ≥18 years with ≥1 RF test performed between 01/01/2006 and 31/12/2011, without a pre-existing diagnosis of RA. Outcome measures were an incident diagnosis of RA within 1 year of testing, and the cost of testing per case of RA. 495,434/4,796,498 (10.3%) patients were tested at least once. 107,362 (21.7%) of those tested were sero-positive of which 2768 (2.6%) were diagnosed with RA within 1 year as were 1141/388,072 (0.3%) sero-negative participants. The sensitivity of RF was 70.8% (95% CI 69.4-72.2), specificity 78.7% (78.6-78.8), and positive and negative predictive values 2.6% (2.5-2.7) and 99.7% (99.6-99.7) respectively. Approximately €3,963,472 was spent, with a cost of €1432 per true positive case. Although 10% of patients were tested for RF, most did not have RA. Limiting testing to patients with a higher pre-test probability would significantly reduce the cost of testing. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

  14. 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.

  15. Effect of pH grade on polymer-gel dosimeter and its brachytherapy application

    International Nuclear Information System (INIS)

    Spevacek, V.; Hrbacek, J.; Dvorak, P.; Cechak, T.; Novotny, J.

    2003-01-01

    To evaluate impact of pH grade on characteristics of polymer-gel dosimeter and its application in dose distribution verification in brachytherapy. A polymer-gel dosimeter based on radiation induced polymerization and crosslinking of acrylic monomers (acrylic acid, N,N' methylen-bis-acrylamide) was investigated with respect to its pH grade. pH grade of a dosimeter was varied by concentration of natrium hydroxide. Afterwards, dosimeter was split into several samples which were uniformly irradiated with Co-60 gamma rays. The range of doses applied was usually from 0 to 50 Gy with the main interest in region up to 20 Gy. Evaluation of dosimeter dose response was performed using MRI (T2). Dose response curves obtained were evaluated with respect to pH grade as a parameter. In parallel, there was studied temperature resistance (melting temperature) of gels with various pH grade. pH grade modified polymer-gel dosimeter was then used to compare dose distribution calculated with brachytherapy treatment planning system for simple irradiation geometry with Ir-192 HDR source. Additionaly, Monte Carlo calculated data were also included in the brachytherapy study. There was observed effect of pH grade on dose-response curve parameters (slope of linear fit, background response, linear range and maximum measurable dose). In general, the lower pH grade the higher sensitivity. Another positive effect of decreased pH grade is significantly higher maximum measurable dose. Maximum melting temperature of a gel was observed with pH grade between 3.5 and 4. For both higher and lower pH grades the melting temperature was lower. Using pH modified polymer-gel dosimeter simple brachytherapy dose distribution was measured and compared with calculated and Monte Carlo simulated data. There was observed strong dependence of dose-response relationship on pH grade of polymer-gel dosimeter resulting in significant improvement of dosimeter characteristics, namely sensitivity, applicable range of

  16. 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 ...

  17. Low pH Cements

    International Nuclear Information System (INIS)

    Savage, David; Benbow, Steven

    2007-05-01

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit ≤ 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio ≤ 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  18. Low pH Cements

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-05-15

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit {<=} 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio {<=} 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  19. Streptococcus oligofermentans Inhibits Streptococcus mutans in Biofilms at Both Neutral pH and Cariogenic Conditions.

    Science.gov (United States)

    Bao, Xudong; de Soet, Johannes Jacob; Tong, Huichun; Gao, Xuejun; He, Libang; van Loveren, Cor; Deng, Dong Mei

    2015-01-01

    Homeostasis of oral microbiota can be maintained through microbial interactions. Previous studies showed that Streptococcus oligofermentans, a non-mutans streptococci frequently isolated from caries-free subjects, inhibited the cariogenic Streptococcus mutans by the production of hydrogen peroxide (HP). Since pH is a critical factor in caries formation, we aimed to study the influence of pH on the competition between S. oligofermentans and S. mutans in biofilms. To this end, S. mutans and S. oligofermentans were inoculated alone or mixed at 1:1 ratio in buffered biofilm medium in a 96-well active attachment model. The single- and dual-species biofilms were grown under either constantly neutral pH or pH-cycling conditions. The latter includes two cycles of 8 h neutral pH and 16 h pH 5.5, used to mimic cariogenic condition. The 48 h biofilms were analysed for the viable cell counts, lactate and HP production. The last two measurements were carried out after incubating the 48 h biofilms in buffers supplemented with 1% glucose (pH 7.0) for 4 h. The results showed that S. oligofermentans inhibited the growth of S. mutans in dual-species biofilms under both tested pH conditions. The lactic acid production of dual-species biofilms was significantly lower than that of single-species S. mutans biofilms. Moreover, dual-species and single-species S. oligofermentans biofilms grown under pH-cycling conditions (with a 16 h low pH period) produced a significantly higher amount of HP than those grown under constantly neutral pH. In conclusion, S. oligofermentans inhibited S. mutans in biofilms not only under neutral pH, but also under pH-cycling conditions, likely through HP production. S. oligofermentans may be a compelling probiotic candidate against caries.

  20. 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.

  1. Genetically encoded proton sensors reveal activity-dependent pH changes in neurons

    Directory of Open Access Journals (Sweden)

    Joseph Valentino Raimondo

    2012-05-01

    Full Text Available The regulation of hydrogen ion concentration (pH is fundamental to cell viability, metabolism and enzymatic function. Within the nervous system, the control of pH is also involved in diverse and dynamic processes including development, synaptic transmission and the control of network excitability. As pH affects neuronal activity, and can also itself be altered by neuronal activity, the existence of tools to accurately measure hydrogen ion fluctuations is important for understanding the role pH plays under physiological and pathological conditions. Outside of their use as a marker of synaptic release, genetically encoded pH sensors have not been utilised to study hydrogen ion fluxes associated with network activity. By combining whole-cell patch clamp with simultaneous two-photon or confocal imaging, we quantified the amplitude and time course of neuronal, intracellular, acidic transients evoked by epileptiform activity in two separate in vitro models of temporal lobe epilepsy. In doing so, we demonstrate the suitability of three genetically encoded pH sensors: deGFP4, E2GFP and Cl-sensor for investigating activity-dependent pH changes at the level of single neurons.

  2. Genetically encoded proton sensors reveal activity-dependent pH changes in neurons.

    Science.gov (United States)

    Raimondo, Joseph V; Irkle, Agnese; Wefelmeyer, Winnie; Newey, Sarah E; Akerman, Colin J

    2012-01-01

    The regulation of hydrogen ion concentration (pH) is fundamental to cell viability, metabolism, and enzymatic function. Within the nervous system, the control of pH is also involved in diverse and dynamic processes including development, synaptic transmission, and the control of network excitability. As pH affects neuronal activity, and can also itself be altered by neuronal activity, the existence of tools to accurately measure hydrogen ion fluctuations is important for understanding the role pH plays under physiological and pathological conditions. Outside of their use as a marker of synaptic release, genetically encoded pH sensors have not been utilized to study hydrogen ion fluxes associated with network activity. By combining whole-cell patch clamp with simultaneous two-photon or confocal imaging, we quantified the amplitude and time course of neuronal, intracellular, acidic transients evoked by epileptiform activity in two separate in vitro models of temporal lobe epilepsy. In doing so, we demonstrate the suitability of three genetically encoded pH sensors: deGFP4, E(2)GFP, and Cl-sensor for investigating activity-dependent pH changes at the level of single neurons.

  3. Effect of single oral dose of tramadol on gastric secretions pH

    Directory of Open Access Journals (Sweden)

    Khan Mueen Ullah

    2015-01-01

    Full Text Available Background: Tramadol is an atypical analgesic agent. It has been shown that intramuscular or intravenous injection tramadol is able to inhibit M3 muscarinic receptors. Tramadol is able to mediate smooth muscles contraction and glandular secretions. We have evaluated the effects of single oral dose of tramadol given preoperatively on gastric juices pH in patients electively scheduled for laparoscopic cholecystectomy. Materials and Methods: Sixty adult, American Society of Anesthesiologist I and II patients scheduled for laparoscopic cholecystectomy were included in the study. Patients were randomly assigned to receive either placebo (n = 30 or oral tramadol 50 mg (n = 30. General anesthesia was induced using propofol, fentanyl and cisatracurium. After induction of anesthesia 5 ml of gastric fluid was aspirated through orogastric tube. The gastric fluid pH was measured using pH meter. Result: There was no significant difference in the pH between the groups. Gastric pH of the placebo and tramadol groups was 1.97 versus 1.98 (P = 0.092 respectively. Conclusion: Preoperatively single oral dose of tramadol was unable to elevate the desired level of gastric acid secretions pH (>2.5. This may be due to pharmacokinetic disparity between the analgesic and pH elevating properties of tramadol.

  4. Inhibitors of acid secretion can benefit gastric wound repair independent of luminal pH effects on the site of damage

    Science.gov (United States)

    Demitrack, Elise S; Aihara, Eitaro; Kenny, Susan; Varro, Andrea; Montrose, Marshall H

    2012-01-01

    Background and aims The authors’ goal was to measure pH at the gastric surface (pHo) to understand how acid secretion affects the repair of microscopic injury to the gastric epithelium. Methods Microscopic gastric damage was induced by laser light, during confocal/two-photon imaging of pH-sensitive dyes (Cl-NERF, BCECF) that were superfused over the mucosal surface of the exposed gastric corpus of anaesthetised mice. The progression of repair was measured in parallel with pHo. Experimental conditions included varying pH of luminal superfusates, and using omeprazole (60 mg/kg ip) or famotidine (30 mg/kg ip) to inhibit acid secretion. Results Similar rates of epithelial repair and resting pHo values (~pH 4) were reported in the presence of luminal pH 3 or pH 5. Epithelial repair was unreliable at luminal pH 2 and pHo was lower (2.5±0.2, P pH 3). Epithelial repair was slower at luminal pH 7 and pHo was higher (6.4±0.1, PpH 3 or pH 7, omeprazole reduced maximal damage size and accelerated epithelial repair, although only at pH 3 did omeprazole further increase surface pH above the level caused by imposed damage. At luminal pH 7, famotidine also reduced maximal damage size and accelerated epithelial repair. Neither famotidine nor omeprazole raised plasma gastrin levels during the time course of the experiments. Conclusions Epithelial repair in vivo is affected by luminal pH variation, but the beneficial effects of acutely blocking acid secretion extend beyond simply raising luminal and/or surface pH. PMID:21997560

  5. 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

  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. Monitoring Intracellular pH Change with a Genetically Encoded and Ratiometric Luminescence Sensor in Yeast and Mammalian Cells.

    Science.gov (United States)

    Zhang, Yunfei; Robertson, J Brian; Xie, Qiguang; Johnson, Carl Hirschie

    2016-01-01

    "pHlash" is a novel bioluminescence-based pH sensor for measuring intracellular pH, which is developed based on Bioluminescence Resonance Energy Transfer (BRET). pHlash is a fusion protein between a mutant of Renilla luciferase (RLuc) and a Venus fluorophore. The spectral emission of purified pHlash protein exhibits pH dependence in vitro. When expressed in either yeast or mammalian cells, pHlash reports basal pH and cytosolic acidification. In this chapter, we describe an in vitro characterization of pHlash, and also in vivo assays including in yeast cells and in HeLa cells using pHlash as a cytoplasmic pH indicator.

  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. Determination of water pH using absorption-based optical sensors: evaluation of different calculation methods

    Science.gov (United States)

    Wang, Hongliang; Liu, Baohua; Ding, Zhongjun; Wang, Xiangxin

    2017-02-01

    Absorption-based optical sensors have been developed for the determination of water pH. In this paper, based on the preparation of a transparent sol-gel thin film with a phenol red (PR) indicator, several calculation methods, including simple linear regression analysis, quadratic regression analysis and dual-wavelength absorbance ratio analysis, were used to calculate water pH. Results of MSSRR show that dual-wavelength absorbance ratio analysis can improve the calculation accuracy of water pH in long-term measurement.

  12. 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.

  13. Noninvasive model including right ventricular speckle tracking for the evaluation of pulmonary hypertension.

    Science.gov (United States)

    Mahran, Yossra; Schueler, Robert; Weber, Marcel; Pizarro, Carmen; Nickenig, Georg; Skowasch, Dirk; Hammerstingl, Christoph

    2016-08-26

    To find parameters from transthorathic echocardiography (TTE) including speckle-tracking (ST) analysis of the right ventricle (RV) to identify precapillary pulmonary hypertension (PH). Forty-four patients with suspected PH undergoing right heart catheterization (RHC) were consecutively included (mean age 63.1 ± 14 years, 61% male gender). All patients underwent standardized TTE including ST analysis of the RV. Based on the subsequent TTE-derived measurements, the presence of PH was assessed: Left ventricular ejection fraction (LVEF) was calculated by Simpsons rule from 4Ch. Systolic pulmonary artery pressure (sPAP) was assessed with continuous wave Doppler of systolic tricuspid regurgitant velocity and regarded raised with values ≥ 30 mmHg as a surrogate parameter for RA pressure. A concomitantly elevated PCWP was considered a means to discriminate between the precapillary and postcapillary form of PH. PCWP was considered elevated when the E/e' ratio was > 12 as a surrogate for LV diastolic pressure. E/e' ratio was measured by gauging systolic and diastolic velocities of the lateral and septal mitral valve annulus using TDI mode. The results were then averaged with conventional measurement of mitral valve inflow. Furthermore, functional testing with six minutes walking distance (6MWD), ECG-RV stress signs, NT pro-BNP and other laboratory values were assessed. PH was confirmed in 34 patients (precapillary PH, n = 15, postcapillary PH, n = 19). TTE showed significant differences in E/e' ratio (precapillary PH: 12.3 ± 4.4, postcapillary PH: 17.3 ± 10.3, no PH: 12.1 ± 4.5, P = 0.02), LV volumes (ESV: 25.0 ± 15.0 mL, 49.9 ± 29.5 mL, 32.2 ± 13.6 mL, P = 0.027; EDV: 73.6 ± 24.0 mL, 110.6 ± 31.8 mL, 87.8 ± 33.0 mL, P = 0.021) and systolic pulmonary arterial pressure (sPAP: 61.2 ± 22.3 mmHg, 53.6 ± 20.1 mmHg, 31.2 ± 24.6 mmHg, P = 0.001). STRV analysis showed significant differences for apical RV longitudinal strain (RVAS: -7.5% ± 5.6%, -13.3% ± 4.3%, -14

  14. 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.

  15. 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...

  16. pH matters

    DEFF Research Database (Denmark)

    Inaba, Masanori; Quinson, Jonathan; Arenz, Matthias

    2017-01-01

    We investigated the influence of the ink properties of proton exchange membrane fuel cell (PEMFC) catalysts on the oxygen reduction reaction (ORR) activity determined in thin film rotating disk electrode (TF-RDE) measurements. It was found that the adaption of a previously reported ink recipe...

  17. 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

  18. Salivary pH as a marker of plasma adiponectin concentrations in Women

    Directory of Open Access Journals (Sweden)

    Tremblay Monique

    2012-02-01

    Full Text Available Abstract Background Plasma adiponectin is a significant correlate of the pro-inflammatory cardiometabolic risk profile associated with obesity and type 2 diabetes. Salivary pH is influenced by several cardiometabolic risk components such as inflammation, oxidation and numerous oral and systemic health modulators, including the menopausal status. This study aimed to assess the association between plasma adiponectin concentrations and salivary pH in women according to the menopausal status. Method Unstimulated saliva collection was performed in 151 Caucasian women of French-Canadian origin (53 premenopausal women (PMW and 98 menopausal women (MW. Student's t test, ANOVA and linear regression models were used to assess the association between plasma adiponectin concentrations and salivary pH. Results Plasma adiponectin levels increased as a function of salivary pH in the whole sample and among MW (r = 0.29 and r = 0.36, p 2 was 10.8% (p Conclusions These results suggest that salivary pH is a significant correlate of plasma adiponectin levels in women. With the increasing prevalence of type 2 diabetes and obesity, new technologies should be developed to more easily monitor health status, disease onset and progression. Salivary pH, a simple, inexpensive and non-invasive measure, could be a very promising avenue.

  19. High pH ammonia toxicity, and the search for life on the Jovian planets.

    Science.gov (United States)

    Deal, P H; Souza, K A; Mack, H M

    1975-10-01

    Jovian plants have enviroments apparently suitable for the evolution of life, but nevertheless, present severe challenges to organisms. One such challenge arises from the presence of ammonia. Ammonia is an efficient biocide, its effect being dependent on pH as well as on concentration. The effects of pH and ammonia concentration were studied separately, where possible, on a variety of organisms, including some isolated from natural enviornments of high pH and/or ammonia concentration. Escherichia coli and Bacillus subtilis are both extremely sensitive to ammonia. An aerobic organism (growth up to pH 11.4) from an alkaline spring is more resistant, but exhibits a toxic response to ammonia at a pH much lower than its maximum for growth. The greatest ammonia resistance has been found in an unidentified organism growing at near neutral pH. Even in this case, however, survival at ammonia concentrations reasonably expected on the Jovian planets is measured in hours. This is, nevertheless, two to three orders of magnitude longer than for E. coli. Our data support the tentative conclusion that contamination of the Jovian planets with terrestrial organisms that can grow is unlikely. However, the range of toxic response noted, coupled with the observation that terrestrial life has not been exposed to high ammonia concentrations for millions of years, suggests that adaptation to greater ammonia tolerance may be possible.

  20. CARINA data synthesis project: pH data scale unification and cruise adjustments

    Science.gov (United States)

    Velo, A.; Pérez, F. F.; Lin, X.; Key, R. M.; Tanhua, T.; de La Paz, M.; Olsen, A.; van Heuven, S.; Jutterström, S.; Ríos, A. F.

    2010-05-01

    Data on carbon and carbon-relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruise data sets in the Artic Mediterranean Seas (AMS), Atlantic Ocean and Southern Ocean have been retrieved and merged to a new database: CARINA (CARbon IN the Atlantic Ocean). These data have gone through rigorous quality control (QC) procedures to assure the highest possible quality and consistency. The data for most of the measured parameters in the CARINA database were objectively examined in order to quantify systematic differences in the reported values. Systematic biases found in the data have been corrected in the data products, three merged data files with measured, calculated and interpolated data for each of the three CARINA regions; AMS, Atlantic Ocean and Southern Ocean. Out of a total of 188 cruise entries in the CARINA database, 59 reported pH measured values. All reported pH data have been unified to the Sea-Water Scale (SWS) at 25 °C. Here we present details of the secondary QC of pH in the CARINA database and the scale unification to SWS at 25 °C. The pH scale has been converted for 36 cruises. Procedures of quality control, including crossover analysis between cruises and inversion analysis are described. Adjustments were applied to the pH values for 21 of the cruises in the CARINA dataset. With these adjustments the CARINA database is consistent both internally as well as with the GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s. Based on our analysis we estimate the internal consistency of the CARINA pH data to be 0.005 pH units. The CARINA data are now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates, for ocean acidification assessment and for model validation.

  1. CARINA data synthesis project: pH data scale unification and cruise adjustments

    Directory of Open Access Journals (Sweden)

    A. Velo

    2010-05-01

    Full Text Available Data on carbon and carbon-relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruise data sets in the Artic Mediterranean Seas (AMS, Atlantic Ocean and Southern Ocean have been retrieved and merged to a new database: CARINA (CARbon IN the Atlantic Ocean.

    These data have gone through rigorous quality control (QC procedures to assure the highest possible quality and consistency. The data for most of the measured parameters in the CARINA database were objectively examined in order to quantify systematic differences in the reported values. Systematic biases found in the data have been corrected in the data products, three merged data files with measured, calculated and interpolated data for each of the three CARINA regions; AMS, Atlantic Ocean and Southern Ocean. Out of a total of 188 cruise entries in the CARINA database, 59 reported pH measured values. All reported pH data have been unified to the Sea-Water Scale (SWS at 25 °C.

    Here we present details of the secondary QC of pH in the CARINA database and the scale unification to SWS at 25 °C. The pH scale has been converted for 36 cruises. Procedures of quality control, including crossover analysis between cruises and inversion analysis are described. Adjustments were applied to the pH values for 21 of the cruises in the CARINA dataset. With these adjustments the CARINA database is consistent both internally as well as with the GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s. Based on our analysis we estimate the internal consistency of the CARINA pH data to be 0.005 pH units. The CARINA data are now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates, for ocean acidification assessment and for model validation.

  2. 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

  3. Salivary pH changes in children after industrialized fruit juice consumption

    OpenAIRE

    Juliana Yassue Barbosa da SILVA; João Armando BRANCHER; João Gilberto DUDA; Estela Maris LOSSO

    2008-01-01

    Introduction: The children presented dental erosion and caries in early infancy that were associated to a rich diet in sugars, including the frequent ingestion of industrialized fruit juice (conditioned in boxes).The drink ingestion with pH lower than 5.5 can cause teeth erosion mainly if it is associated with frequent and prolonged teeth contact.The natural protection of teeth is the saliva through its buffering capacity.Objective: Measure the children salivary pH before and after the grape ...

  4. Critical review of pH sensing with optical fibers

    Science.gov (United States)

    Baldini, Francesco

    1999-02-01

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

  5. 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.

  6. [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.

  7. Zonal NePhRO scoring system: a superior renal tumor complexity classification model.

    Science.gov (United States)

    Hakky, Tariq S; Baumgarten, Adam S; Allen, Bryan; Lin, Hui-Yi; Ercole, Cesar E; Sexton, Wade J; Spiess, Philippe E

    2014-02-01

    Since the advent of the first standardized renal tumor complexity system, many subsequent scoring systems have been introduced, many of which are complicated and can make it difficult to accurately measure data end points. In light of these limitations, we introduce the new zonal NePhRO scoring system. The zonal NePhRO score is based on 4 anatomical components that are assigned a score of 1, 2, or 3, and their sum is used to classify renal tumors. The zonal NePhRO scoring system is made up of the (Ne)arness to collecting system, (Ph)ysical location of the tumor in the kidney, (R)adius of the tumor, and (O)rganization of the tumor. In this retrospective study, we evaluated patients exhibiting clinical stage T1a or T1b who underwent open partial nephrectomy performed by 2 genitourinary surgeons. Each renal unit was assigned both a zonal NePhRO score and a RENAL (radius, exophytic/endophytic properties, nearness of tumor to the collecting system or sinus in millimeters, anterior/posterior, location relative to polar lines) score, and a blinded reviewer used the same preoperative imaging study to obtain both scores. Additional data points gathered included age, clamp time, complication rate, urine leak rate, intraoperative blood loss, and pathologic tumor size. One hundred sixty-six patients underwent open partial nephrectomy. There were 37 perioperative complications quantitated using the validated Clavien-Dindo system; their occurrence was predicted by the NePhRO score on both univariate and multivariate analyses (P = .0008). Clinical stage, intraoperative blood loss, and tumor diameter were all correlated with the zonal NePhRO score on univariate analysis only. The zonal NePhRO scoring system is a simpler tool that accurately predicts the surgical complexity of a renal lesion. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Evaluation of Macerating Pectinase Enzyme Activity under Various Temperature, pH and Ethanol Regimes

    Directory of Open Access Journals (Sweden)

    Andrew G. Reynolds

    2018-02-01

    Full Text Available The polygalacturonase (PGU, hemicellulase (mannanase and protease enzyme activities in commercial macerating, pectinase-enzyme preparations commonly used by wineries in Ontario (Scottzyme Color X and Color Pro were measured under various simulated process conditions (temperature, pH, and ethanol concentration. Treatments included three temperatures (15, 20 and 30 °C; pH = 3.0, 3.5, 4.0 and 5.0; ethanol = 0%, four pH levels (3.0, 3.5, 4.0 and 5.0; temperature = 15, 20, 30 and 50 °C; ethanol = 0%, and four ethanol concentrations ((2.5, 5, 7.5 and 10%; temperature = 20 °C and pH = 3.5. Polygalacturonase enzyme activity in Color X increased linearly with temperature at all pH levels, and increased with pH at all temperature regimes. Polygalacturonase activity decreased with increasing ethanol. Color X mannanase activity increased with temperatures between 15 and 40 °C, and decreased with increased pH between 3.0 and 5.0. Response of mannanase to ethanol was cubic with a sharp decrease between 8 and 10% ethanol. Protease activity increased linearly with temperatures between 20 and 40 °C. These data suggest that the PGU, mannanase and protease components in these enzyme products provide sufficient activities within the ranges of pH, temperature, and ethanol common during the initial stages of red wine fermentations, although low must temperatures (<20 °C and presence of ethanol would likely lead to sub-optimal enzyme activities.

  9. PhD supervisor-student relationship

    Directory of Open Access Journals (Sweden)

    FILIPE PRAZERES

    2017-10-01

    but also improve their coping skills, including critical thinking and problem-solving methods (5. The act of sharing knowledge and experiences can motivate the PhD students to persevere in their studies (10. When needed, supervisors should use their power of influence to increase the time that the student has available to devote to research while maintaining a part of their employment activities (health care‑related or not, since many PhD students are also full-time workers. Last but not least, supervisors and faculty members must encourage PhD students to pursue the available funding opportunities. Socioeconomic problems are known to be an issue for PhD students (5. Without the supervisor’s support – by dealing with PhD student’s emotions and personality –, research time, funding, and the student’s proactiviness, the doctoral journey may not attain success.

  10. 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 ...

  11. 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 ...

  12. 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.

  13. 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.

  14. Live imaging of intra- and extracellular pH in plants using pHusion, a novel genetically encoded biosensor

    Science.gov (United States)

    Gjetting, Kisten Sisse Krag; Ytting, Cecilie Karkov; Schulz, Alexander; Fuglsang, Anja Thoe

    2012-01-01

    Changes in pH are now widely accepted as a signalling mechanism in cells. In plants, proton pumps in the plasma membrane and tonoplast play a key role in regulation of intracellular pH homeostasis and maintenance of transmembrane proton gradients. Proton transport in response to external stimuli can be expected to be finely regulated spatially and temporally. With the ambition to follow such changes live, a new genetically encoded sensor, pHusion, has been developed. pHusion is especially designed for apoplastic pH measurements. It was constitutively expressed in Arabidopsis and targeted for expression in either the cytosol or the apoplast including intracellular compartments. pHusion consists of the tandem concatenation of enhanced green fluorescent protein (EGFP) and monomeric red fluorescent protein (mRFP1), and works as a ratiometric pH sensor. Live microscopy at high spatial and temporal resolution is highly dependent on appropriate immobilization of the specimen for microscopy. Medical adhesive often used in such experiments destroys cell viability in roots. Here a novel system for immobilizing Arabidopsis seedling roots for perfusion experiments is presented which does not impair cell viability. With appropriate immobilization, it was possible to follow changes of the apoplastic and cytosolic pH in mesophyll and root tissue. Rapid pH homeostasis upon external pH changes was reflected by negligible cytosolic pH fluctuations, while the apoplastic pH changed drastically. The great potential for analysing pH regulation in a whole-tissue, physiological context is demonstrated by the immediate alkalinization of the subepidermal apoplast upon external indole-3-acetic acid administration. This change is highly significant in the elongation zone compared with the root hair zone and control roots. PMID:22407646

  15. Live imaging of intra- and extracellular pH in plants using pHusion, a novel genetically encoded biosensor.

    Science.gov (United States)

    Gjetting, Kisten Sisse Krag; Ytting, Cecilie Karkov; Schulz, Alexander; Fuglsang, Anja Thoe

    2012-05-01

    Changes in pH are now widely accepted as a signalling mechanism in cells. In plants, proton pumps in the plasma membrane and tonoplast play a key role in regulation of intracellular pH homeostasis and maintenance of transmembrane proton gradients. Proton transport in response to external stimuli can be expected to be finely regulated spatially and temporally. With the ambition to follow such changes live, a new genetically encoded sensor, pHusion, has been developed. pHusion is especially designed for apoplastic pH measurements. It was constitutively expressed in Arabidopsis and targeted for expression in either the cytosol or the apoplast including intracellular compartments. pHusion consists of the tandem concatenation of enhanced green fluorescent protein (EGFP) and monomeric red fluorescent protein (mRFP1), and works as a ratiometric pH sensor. Live microscopy at high spatial and temporal resolution is highly dependent on appropriate immobilization of the specimen for microscopy. Medical adhesive often used in such experiments destroys cell viability in roots. Here a novel system for immobilizing Arabidopsis seedling roots for perfusion experiments is presented which does not impair cell viability. With appropriate immobilization, it was possible to follow changes of the apoplastic and cytosolic pH in mesophyll and root tissue. Rapid pH homeostasis upon external pH changes was reflected by negligible cytosolic pH fluctuations, while the apoplastic pH changed drastically. The great potential for analysing pH regulation in a whole-tissue, physiological context is demonstrated by the immediate alkalinization of the subepidermal apoplast upon external indole-3-acetic acid administration. This change is highly significant in the elongation zone compared with the root hair zone and control roots.

  16. Valuation of Green Walls and Green Roofs as Soundscape Measures: Including Monetised Amenity Values Together with Noise-attenuation Values in a Cost-benefit Analysis of a Green Wall Affecting Courtyards

    Science.gov (United States)

    Veisten, Knut; Smyrnova, Yuliya; Klæboe, Ronny; Hornikx, Maarten; Mosslemi, Marjan; Kang, Jian

    2012-01-01

    Economic unit values of soundscape/acoustic effects have been based on changes in the number of annoyed persons or on decibel changes. The normal procedure has been the application of these unit values to noise-attenuation measures affecting the noisier façade of a dwelling. Novel modular vegetation-based soundscape measures, so-called green walls, might be relevant for both noisy and quieter areas. Moreover, their benefits will comprise noise attenuation as well as non-acoustic amenity effects. One challenge is to integrate the results of some decades of non-acoustic research on the amenity value of urban greenery into design of the urban sound environment, and incorporate these non-acoustic properties in the overall economic assessment of noise control and overall sound environment improvement measures. Monetised unit values for green walls have been included in two alternative cases, or demonstration projects, of covering the entrances to blocks of flats with a green wall. Since these measures improve the noise environment on the quiet side of the dwellings and courtyards, not the most exposed façade, adjustment factors to the nominal quiet side decibel reductions to arrive at an estimate of the equivalent overall acoustic improvement have been applied. A cost-benefit analysis of the green wall case indicates that this measure is economically promising, when valuing the noise attenuation in the quieter area and adding the amenity/aesthetic value of the green wall. PMID:23202816

  17. Valuation of Green Walls and Green Roofs as Soundscape Measures: Including Monetised Amenity Values Together with Noise-attenuation Values in a Cost-benefit Analysis of a Green Wall Affecting Courtyards

    Directory of Open Access Journals (Sweden)

    Jian Kang

    2012-10-01

    Full Text Available Economic unit values of soundscape/acoustic effects have been based on changes in the number of annoyed persons or on decibel changes. The normal procedure has been the application of these unit values to noise-attenuation measures affecting the noisier façade of a dwelling. Novel modular vegetation-based soundscape measures, so-called green walls, might be relevant for both noisy and quieter areas. Moreover, their benefits will comprise noise attenuation as well as non-acoustic amenity effects. One challenge is to integrate the results of some decades of non-acoustic research on the amenity value of urban greenery into design of the urban sound environment, and incorporate these non-acoustic properties in the overall economic assessment of noise control and overall sound environment improvement measures. Monetised unit values for green walls have been included in two alternative cases, or demonstration projects, of covering the entrances to blocks of flats with a green wall. Since these measures improve the noise environment on the quiet side of the dwellings and courtyards, not the most exposed façade, adjustment factors to the nominal quiet side decibel reductions to arrive at an estimate of the equivalent overall acoustic improvement have been applied. A cost-benefit analysis of the green wall case indicates that this measure is economically promising, when valuing the noise attenuation in the quieter area and adding the amenity/aesthetic value of the green wall.

  18. New seismograph includes filters

    Energy Technology Data Exchange (ETDEWEB)

    1979-11-02

    The new Nimbus ES-1210 multichannel signal enhancement seismograph from EG and G geometrics has recently been redesigned to include multimode signal fillers on each amplifier. The ES-1210F is a shallow exploration seismograph for near subsurface exploration such as in depth-to-bedrock, geological hazard location, mineral exploration, and landslide investigations.

  19. Next Generation Qualification: Nanometrics T120PH Seismometer Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, Bion J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Slad, George William [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-01

    Sandia National Laboratories has tested and evaluated three seismometers, the Trillium 120PH, manufactured by Nanometrics. These seismometers measure broadband ground velocity using a UVW configuration with feedback control in a mechanically levelled borehole package. The purpose of the seismometer evaluation was to determine a measured sensitivity, response, self- noise, dynamic range, and self-calibration ability. The Nanometrics Trillium 120PH seismometers are being evaluated for the U.S. Air Force as part of their Next Generation Qualification effort.

  20. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system

    Science.gov (United States)

    Raimondo, Joseph V.; Joyce, Bradley; Kay, Louise; Schlagheck, Theresa; Newey, Sarah E.; Srinivas, Shankar; Akerman, Colin J.

    2013-01-01

    Within the nervous system, intracellular Cl− and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission, and network excitability. Cl− and pH are often co-regulated, and network activity results in the movement of both Cl− and H+. Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl− and pH sensors have been described previously, these either lack ion specificity or are unsuitable for neuronal use. Here we present ClopHensorN—a new genetically-encoded ratiometric Cl− and pH sensor that is optimized for the nervous system. We demonstrate the ability of ClopHensorN to dissociate and simultaneously quantify Cl− and H+ concentrations under a variety of conditions. In addition, we establish the sensor's utility by characterizing activity-dependent ion dynamics in hippocampal neurons. PMID:24312004

  1. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system.

    Science.gov (United States)

    Raimondo, Joseph V; Joyce, Bradley; Kay, Louise; Schlagheck, Theresa; Newey, Sarah E; Srinivas, Shankar; Akerman, Colin J

    2013-01-01

    Within the nervous system, intracellular Cl(-) and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission, and network excitability. Cl(-) and pH are often co-regulated, and network activity results in the movement of both Cl(-) and H(+). Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl(-) and pH sensors have been described previously, these either lack ion specificity or are unsuitable for neuronal use. Here we present ClopHensorN-a new genetically-encoded ratiometric Cl(-) and pH sensor that is optimized for the nervous system. We demonstrate the ability of ClopHensorN to dissociate and simultaneously quantify Cl(-) and H(+) concentrations under a variety of conditions. In addition, we establish the sensor's utility by characterizing activity-dependent ion dynamics in hippocampal neurons.

  2. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system

    Directory of Open Access Journals (Sweden)

    Joseph Valentino Raimondo

    2013-11-01

    Full Text Available Within the nervous system, intracellular Cl- and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission and network excitability. Cl- and pH are often co-regulated, and network activity results in the movement of both Cl- and H+. Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl- and pH sensors have been described previously, these either lack ion specificity or are unsuitable for neuronal use. Here we present ClopHensorN - a new genetically-encoded ratiometric Cl- and pH sensor that is optimized for the nervous system. We demonstrate the ability of ClopHensorN to dissociate and simultaneously quantify Cl- and H+ concentrations under a variety of conditions. In addition, we establish the sensor’s utility by characterizing activity-dependent ion dynamics in hippocampal neurons.

  3. δ11B as monitor of calcification site pH in divergent marine calcifying organisms

    Science.gov (United States)

    Sutton, Jill N.; Liu, Yi-Wei; Ries, Justin B.; Guillermic, Maxence; Ponzevera, Emmanuel; Eagle, Robert A.

    2018-03-01

    The boron isotope composition (δ11B) of marine biogenic carbonates has been predominantly studied as a proxy for monitoring past changes in seawater pH and carbonate chemistry. However, a number of assumptions regarding chemical kinetics and thermodynamic isotope exchange reactions are required to derive seawater pH from δ11B biogenic carbonates. It is also probable that δ11B of biogenic carbonate reflects seawater pH at the organism's site of calcification, which may or may not reflect seawater pH. Here, we report the development of methodology for measuring the δ11B of biogenic carbonate samples at the multi-collector inductively coupled mass spectrometry facility at Ifremer (Plouzané, France) and the evaluation of δ11BCaCO3 in a diverse range of marine calcifying organisms reared for 60 days in isothermal seawater (25 °C) equilibrated with an atmospheric pCO2 of ca. 409 µatm. Average δ11BCaCO3 composition for all species evaluated in this study range from 16.27 to 35.09 ‰, including, in decreasing order, coralline red alga Neogoniolithion sp. (35.89 ± 3.71 ‰), temperate coral Oculina arbuscula (24.12 ± 0.19 ‰), serpulid worm Hydroides crucigera (19.26 ± 0.16 ‰), tropical urchin Eucidaris tribuloides (18.71 ± 0.26 ‰), temperate urchin Arbacia punctulata (16.28 ± 0.86 ‰), and temperate oyster Crassostrea virginica (16.03 ‰). These results are discussed in the context of each species' proposed mechanism of biocalcification and other factors that could influence skeletal and shell δ11B, including calcifying site pH, the proposed direct incorporation of isotopically enriched boric acid (instead of borate) into biogenic calcium carbonate, and differences in shell/skeleton polymorph mineralogy. We conclude that the large inter-species variability in δ11BCaCO3 (ca. 20 ‰) and significant discrepancies between measured δ11BCaCO3 and δ11BCaCO3 expected from established relationships between abiogenic δ11BCaCO3 and seawater pH arise

  4. A cow-level association of ruminal pH on body condition score, serum beta-hydroxybutyrate and postpartum disorders in Thai dairy cattle.

    Science.gov (United States)

    Chaidate, Inchaisri; Somchai, Chanpongsang; Jos, Noordhuizen; Henk, Hogeveen

    2014-09-01

    Subacute ruminal acidosis in dairy cows occurs when ruminal pH is below about 5.5. However, the exact threshold level of ruminal pH affecting cow health is still in debate. This investigation was carried out in 505 cows within 31 farms. The postpartum disorders, including dystocia, retained placenta, anestrus, cystic ovary, metritis, clinical mastitis and lameness, were analyzed. Ruminal pH, serum beta-hydroxy butyrate (SBHB), serum urea nitrogen and body condition score (BCS) were measured once during the 3 to 6 weeks postpartum, while BCS was determined once more at 1 week before calving. Ruminal pH was determined by ruminocentesis technique. The ruminal pH was evaluated to study the association with BCS, SBHB and postpartum disorders using linear regression in a generalized linear mixed model with farm as a random effect. The results show that low ruminal pH was associated with dystocia, metritis and lameness. Moreover, a low ruminal pH can be found in cows with a high loss of BCS after calving and also in cows with low SBHB postpartum. These findings confirmed the feasibility of the ruminocentesis technique and the association of low ruminal pH on various postpartum disorders at the individual cow level. However, the consequences of low ruminal pH on dairy cow health still needs more exploration for a better understanding of the physiological mechanisms. © 2014 Japanese Society of Animal Science.

  5. Analytic device including nanostructures

    KAUST Repository

    Di Fabrizio, Enzo M.; Fratalocchi, Andrea; Totero Gongora, Juan Sebastian; Coluccio, Maria Laura; Candeloro, Patrizio; Cuda, Gianni

    2015-01-01

    A device for detecting an analyte in a sample comprising: an array including a plurality of pixels, each pixel including a nanochain comprising: a first nanostructure, a second nanostructure, and a third nanostructure, wherein size of the first nanostructure is larger than that of the second nanostructure, and size of the second nanostructure is larger than that of the third nanostructure, and wherein the first nanostructure, the second nanostructure, and the third nanostructure are positioned on a substrate such that when the nanochain is excited by an energy, an optical field between the second nanostructure and the third nanostructure is stronger than an optical field between the first nanostructure and the second nanostructure, wherein the array is configured to receive a sample; and a detector arranged to collect spectral data from a plurality of pixels of the array.

  6. Saskatchewan resources. [including uranium

    Energy Technology Data Exchange (ETDEWEB)

    1979-09-01

    The production of chemicals and minerals for the chemical industry in Saskatchewan are featured, with some discussion of resource taxation. The commodities mentioned include potash, fatty amines, uranium, heavy oil, sodium sulfate, chlorine, sodium hydroxide, sodium chlorate and bentonite. Following the successful outcome of the Cluff Lake inquiry, the uranium industry is booming. Some developments and production figures for Gulf Minerals, Amok, Cenex and Eldorado are mentioned.

  7. Monte Carlo simulated corrections for beam commissioning measurements with circular and MLC shaped fields on the CyberKnife M6 System: a study including diode, microchamber, point scintillator, and synthetic microdiamond detectors

    Science.gov (United States)

    Francescon, P.; Kilby, W.; Noll, J. M.; Masi, L.; Satariano, N.; Russo, S.

    2017-02-01

    Monte Carlo simulation was used to calculate correction factors for output factor (OF), percentage depth-dose (PDD), and off-axis ratio (OAR) measurements with the CyberKnife M6 System. These include the first such data for the InCise MLC. Simulated detectors include diodes, air-filled microchambers, a synthetic microdiamond detector, and point scintillator. Individual perturbation factors were also evaluated. OF corrections show similar trends to previous studies. With a 5 mm fixed collimator the diode correction to convert a measured OF to the corresponding point dose ratio varies between  -6.1% and  -3.5% for the diode models evaluated, while in a 7.6 mm  ×  7.7 mm MLC field these are  -4.5% to  -1.8%. The corresponding microchamber corrections are  +9.9% to  +10.7% and  +3.5% to  +4.0%. The microdiamond corrections have a maximum of  -1.4% for the 7.5 mm and 10 mm collimators. The scintillator corrections are  15%, reducing to    d max were  M6 Systems and retrospectively checking estimated corrections used previously. We recommend the PDD and OAR corrections are used to guide detector selection and inform the evaluation of results rather than to explicitly correct measurements.

  8. A Reliable and Non-destructive Method for Monitoring the Stromal pH in Isolated Chloroplasts Using a Fluorescent pH Probe

    Directory of Open Access Journals (Sweden)

    Pai-Hsiang Su

    2017-12-01

    Full Text Available The proton gradient established by the pH difference across a biological membrane is essential for many physiological processes, including ATP synthesis and ion and metabolite transport. Currently, ionophores are used to study proton gradients, and determine their importance to biological functions of interest. Because of the lack of an easy method for monitoring the proton gradient across the inner envelope membrane of chloroplasts (ΔpHenv, whether the concentration of ionophores used can effectively abolish the ΔpHenv is not proven for most experiments. To overcome this hindrance, we tried to setup an easy method for real-time monitoring of the stromal pH in buffered, isolated chloroplasts by using fluorescent pH probes; using this method the ΔpHenv can be calculated by subtracting the buffer pH from the measured stromal pH. When three fluorescent dyes, BCECF-AM [2′,7′-bis-(2-carboxyethyl-5-(and-6-carboxyfluorescein acetoxymethyl ester], CFDA-SE [5(6-Carboxyfluorescein diacetate succinimidyl ester] and SNARF-1 carboxylic acid acetate succinimidyl ester were incubated with isolated chloroplasts, BCECF-AM and CFDA-SE, but not the ester-formed SNARF-1 were taken up by chloroplasts and digested with esterase to release high levels of fluorescence. According to its relatively higher pKa value (6.98, near the physiological pH of the stroma, BCECF was chosen for further development. Due to shielding of the excitation and emission lights by chloroplast pigments, the ratiometric fluorescence of BCECF was highly dependent on the concentration of chloroplasts. By using a fixed concentration of chloroplasts, a highly correlated standard curve of pH to the BCECF ratiometric fluorescence with an r-square value of 0.98 was obtained, indicating the reliability of this method. Consistent with previous reports, the light-dependent formation of ΔpHenv can be detected ranging from 0.15 to 0.33 pH units upon illumination. The concentration of the ionophore

  9. 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

  10. RARE DECAYS INCLUDING PENGUINS

    Energy Technology Data Exchange (ETDEWEB)

    Eigen, G

    2003-12-04

    The authors present a preliminary measurement of the exclusive charmless semileptonic B decays, B {yields} {rho}{ell}{nu}, and the extraction of the CKM parameters V{sub ub}. IN a data sample of 55 x 10{sup 6} B{bar B} events they measure a branching fraction of {Beta}(B {yields} {rho}{ell}{nu}) = (3.39 {+-} 0.44{sub stat} {+-} 0.52{sub sys} {+-} 0.60{sub th}) x 10{sup -4} yielding |V{sub ub}| = (3.69 {+-} 0.23{sub stat} {+-} 0.27{sub sys -0.59th}{sup +0.40}) x 10{sup -3}. Next, they report on a preliminary study of the radiative penguin modes B {yields} K{ell}{sup +}{ell}{sup -} and B {yields} K*{ell}{sup +}{ell}{sup -}. In a data sample of 84 x 10{sup 6} B{bar B} events they observe a significant signal (4.4{sigma}) in B {yields} K{ell}{sup +}{ell}{sup -}, yielding a branching fraction of {Beta}(B {yields} K{ell}{sup +}{ell}{sup -}) = (0.78{sub -0.20-0.18}{sup +0.24+0.11}) x 10{sup -6}. In B {yields} K*{ell}{sup +}{ell}{sup -} the observed yield is not yet significant (2.8{sigma}), yielding an upper limit of the branching fraction of {Beta}(B {yields} K*{ell}{sup +}{ell}{sup -}) 3.0 x 10{sup -6} {at} 90% confidence level. Finally, they summarize preliminary results of searches for B {yields} {rho}({omega}){gamma}, B{sup +} {yields} K{sup +} {nu}{bar {nu}} and B{sup 0} {yields} {ell}{sup +}{ell}{sup -}.

  11. Regulation of intracellular pH in cnidarians: response to acidosis in Anemonia viridis.

    Science.gov (United States)

    Laurent, Julien; Venn, Alexander; Tambutté, Éric; Ganot, Philippe; Allemand, Denis; Tambutté, Sylvie

    2014-02-01

    The regulation of intracellular pH (pHi) is a fundamental aspect of cell physiology that has received little attention in studies of the phylum Cnidaria, which includes ecologically important sea anemones and reef-building corals. Like all organisms, cnidarians must maintain pH homeostasis to counterbalance reductions in pHi, which can arise because of changes in either intrinsic or extrinsic parameters. Corals and sea anemones face natural daily changes in internal fluids, where the extracellular pH can range from 8.9 during the day to 7.4 at night. Furthermore, cnidarians are likely to experience future CO₂-driven declines in seawater pH, a process known as ocean acidification. Here, we carried out the first mechanistic investigation to determine how cnidarian pHi regulation responds to decreases in extracellular and intracellular pH. Using the anemone Anemonia viridis, we employed confocal live cell imaging and a pH-sensitive dye to track the dynamics of pHi after intracellular acidosis induced by acute exposure to decreases in seawater pH and NH₄Cl prepulses. The investigation was conducted on cells that contained intracellular symbiotic algae (Symbiodinium sp.) and on symbiont-free endoderm cells. Experiments using inhibitors and Na⁺-free seawater indicate a potential role of Na⁺/H⁺ plasma membrane exchangers (NHEs) in mediating pHi recovery following intracellular acidosis in both cell types. We also measured the buffering capacity of cells, and obtained values between 20.8 and 43.8 mM per pH unit, which are comparable to those in other invertebrates. Our findings provide the first steps towards a better understanding of acid-base regulation in these basal metazoans, for which information on cell physiology is extremely limited. © 2013 FEBS.

  12. Exhaled breath condensate pH and hydrogen peroxide as non-invasive markers for asthma

    International Nuclear Information System (INIS)

    Al-Obaidy, Amina H.; Al-Samarai, Abdul-Gahni M.

    2007-01-01

    Objective was to estimate the predictive value of exhaled breath condensate (EBC) hydrogen peroxide (H2O2) concentration and pH as non-invasive markers in asthma. Fifty patients with unstable, steroid naive atopic asthma were included in this study, 25 with persistent asthma. Asthma diagnosis was according to the National Heart Lung and Blood Institute guidelines for the diagnosis and management of asthma. Forced expiratory volume in one second (FEV1) was measured by computerized spirometry. The EBC H2O2 assay was carried out using the colorimetric assay. The study was conducted from January to December 2005 in the Asthma and Allergy Center, Tikrit, Iraq. The EBC H2O2 concentration was higher in the asthmatic group (0.91mol) as compared with the control (0.23 mol). There was inverse correlation between EBC H2O2 concentration and FEV1 predicted percent for asthmatic patients. The mean EBC pH was lower in the asthmatic than the control group. There was a positive correlation between EBC pH and FEV 1 predicted percent for asthmatic patients. There was an inverse correlation between EBC H2O2 concentration and pH for all asthmatic patients, intermittent, and persistent asthmatic group. Exhaled breath condensate hydrogen peroxide concentration and pH was a good non-invasive marker for asthma, whether it was with a persistent or intermittent course. (author)

  13. High Ph, Ammonia Toxicity, and the Search for Life on the Jovian Planets

    Science.gov (United States)

    Deal, P. H.; Souza, K. A.; Mack, H. M.

    1975-01-01

    The effects of pH and ammonia concentration were studied separately, where possible, on a variety of organisms, including some isolated from natural environments of high pH and/or ammonia concentration. Escherichia coli and Bacillus subtilis are both extremely sensitive to ammonia. An aerobic organism (growth up to pH 11.4) from an alkaline spring is more resistant, but exhibits a toxic response to ammonia at a pH much lower than its maximum for growth. The greatest ammonia resistance has been found in an unidentified organism growing at near neutral pH. Even in this case, however, urvival at ammonia concentrations reasonably expected on the Jovian planets is measured in hours. This is two to three orders of magnitude longer than for E. coli. Results support the tentative conclusion that contamination of the Jovian planets with terrestrial organisms that can grow is unlikely. However, the range of toxic response noted, coupled with the observation that terrestrial life has not been exposed to high ammonia concentrations for millions of years, suggests that adaptation to greater ammonia tolerance may be possible.

  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. Being Included and Excluded

    DEFF Research Database (Denmark)

    Korzenevica, Marina

    2016-01-01

    Following the civil war of 1996–2006, there was a dramatic increase in the labor mobility of young men and the inclusion of young women in formal education, which led to the transformation of the political landscape of rural Nepal. Mobility and schooling represent a level of prestige that rural...... politics. It analyzes how formal education and mobility either challenge or reinforce traditional gendered norms which dictate a lowly position for young married women in the household and their absence from community politics. The article concludes that women are simultaneously excluded and included from...... community politics. On the one hand, their mobility and decision-making powers decrease with the increase in the labor mobility of men and their newly gained education is politically devalued when compared to the informal education that men gain through mobility, but on the other hand, schooling strengthens...

  16. Stratum corneum hydration and skin surface pH in patients with atopic dermatitis.

    Science.gov (United States)

    Knor, Tanja; Meholjić-Fetahović, Ajša; Mehmedagić, Aida

    2011-01-01

    Atopic dermatitis (AD) is a chronically relapsing skin disease with genetic predisposition, which occurs most frequently in preschool children. It is considered that dryness and pruritus, which are always present in AD, are in correlation with degradation of the skin barrier function. Measurement of hydration and pH value of the stratum corneum is one of the noninvasive methods for evaluation of skin barrier function. The aim of the study was to assess skin barrier function by measuring stratum corneum hydration and skin surface pH of the skin with lesions, perilesional skin and uninvolved skin in AD patients, and skin in a healthy control group. Forty-two patients were included in the study: 21 young and adult AD patients and 21 age-matched healthy controls. Capacitance, which is correlated with hydration of stratum corneum and skin surface pH were measured on the forearm in the above areas by SM810/CM820/pH900 combined units (Courage AND Khazaka, Germany). The mean value of water capacitance measured in AD patients was 44.1 ± 11.6 AU (arbitrary units) on the lesions, 60.2 ± 12.4 AU on perilesional skin and 67.2 ± 8.8 AU on uninvolved skin. In healthy controls, the mean value was 74.1 ± 9.2 AU. The mean pH value measured in AD patients was 6.13 ± 0.52 on the lesions, 5.80 ± 0.41 on perilesional skin, and 5.54 ± 0.49 on uninvolved skin. In control group, the mean pH of the skin surface was 5.24 ± 0.40. The values of both parameters measured on lesional skin were significantly different (capacitance decreased and pH increased) from the values recorded on perilesional skin and uninvolved skin. The same held for the relation between perilesional and uninvolved skin. According to study results, the uninvolved skin of AD patients had significantly worse values of the measured parameters as compared with control group. The results of this study suggested the skin barrier function to be degraded in AD patients, which is specifically expressed in lesional skin.

  17. Biobased, Internally pH-Sensitive Materials: Immobilized Yellow Fluorescent Protein as an Optical Sensor for Spatiotemporal Mapping of pH Inside Porous Matrices.

    Science.gov (United States)

    Consolati, Tanja; Bolivar, Juan M; Petrasek, Zdenek; Berenguer, Jose; Hidalgo, Aurelio; Guisán, Jose M; Nidetzky, Bernd

    2018-02-28

    The pH is fundamental to biological function and its measurement therefore crucial across all biosciences. Unlike homogenous bulk solution, solids often feature internal pH gradients due to partition effects and confined biochemical reactions. Thus, a full spatiotemporal mapping for pH characterization in solid materials with biological systems embedded in them is essential. In here, therefore, a fully biocompatible methodology for real-time optical sensing of pH within porous materials is presented. A genetically encoded ratiometric pH sensor, the enhanced superfolder yellow fluorescent protein (sYFP), is used to functionalize the internal surface of different materials, including natural and synthetic organic polymers as well as silica frameworks. By using controlled, tailor-made immobilization, sYFP is homogenously distributed within these materials and so enables, via self-referenced imaging analysis, pH measurements in high accuracy and with useful spatiotemporal resolution. Evolution of internal pH is monitored in consequence of a proton-releasing enzymatic reaction, the hydrolysis of penicillin by a penicillin acylase, taking place in solution or confined to the solid surface of the porous matrix. Unlike optochemical pH sensors, which often interfere with biological function, labeling with sYFP enables pH sensing without altering the immobilized enzyme's properties in any of the materials used. Fast response of sYFP to pH change permits evaluation of biochemical kinetics within the solid materials. Thus, pH sensing based on immobilized sYFP represents a broadly applicable technique to the study of biology confined to the internally heterogeneous environment of solid matrices.

  18. Empirical Algorithms to Predict pH and Aragonite Saturation State on SOCCOM Biogeochemical Argo Floats in the Pacific Sector of the Southern Ocean

    Science.gov (United States)

    Williams, N. L.; Juranek, L. W.; Feely, R. A.; Johnson, K. S.; Russell, J. L.

    2016-02-01

    The Southern Ocean plays a major role in the global uptake, transport, and storage of both heat and carbon, yet it remains one of the least-sampled regions of the ocean. The Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project aims to fill the observational gaps by deploying over 200 autonomous profiling floats in the Southern Ocean over the next several years. Initial float deployments have greatly expanded our observational capability to include wintertime measurements as well as under-ice measurements, and many of these floats include novel biogeochemical sensors (pH, nitrate, oxygen). Here we present empirical algorithms that can be used to predict pH and ΩAragonite from other float-measured parameters (temperature, salinity, pressure, nitrate, oxygen). These algorithms were trained using bottle measurements from high-quality repeat hydrographic GO-SHIP cruises. We obtained R2 values of 0.98 (pH) and 0.99 (ΩAragonite) and RMS errors of 0.007 (pH) and 0.052 (ΩAragonite) for data between 100-1500 m. These algorithms will allow us to both validate pH data from these sensors, as well as predict ΩAragonite and pH on floats that do not have pH sensors. Here we present estimated pH and ΩAragonite over 20 months of deployment for several SOCCOM floats in the Pacific Sector of the Southern Ocean. The results show seasonal ranges in surface pH and ΩAragonite of 0.05 and 0.1, respectively.

  19. pH control and rapid mixing in spinning NMR samples

    Science.gov (United States)

    Yesinowski, James P.; Sunberg, Richard J.; Benedict, James J.

    An apparatus is described which permits the acquisition of NMR spectra from spinning 20-mm sample tubes while: (1) constantly monitoring the pH; (2) adding reagents to maintain constant pH (pH-statting); (3) efficiently mixing the added reagent. The apparatus was built to study the spontaneous precipitation of calcium phosphates from supersaturated solutions using 31P NMR. Other applications include the rapid determination of NMR titration curves, and the minimization of temperature gradients in large sample tubes. The apparatus was used to measure the 31P chemical shift titration of dilute phosphoric acid, which yielded accurate shifts for the three species of protonated orthophosphate ion. The bulk magnetic susceptibility of 85% H 3PO 4 relative to a dilute aqueous sample was also measured, and is shown to contribute significantly to chemical shift measurements.

  20. 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.

  1. 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,

  2. 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...

  3. Development of measures to assess the safety of existing NPPs and the effectiveness of regulations and regulatory actions (including 'prescriptive' and 'performance based' approaches). Peer discussions on regulatory practices

    International Nuclear Information System (INIS)

    1996-09-01

    This report arises from the fourth series of peer discussions on regulatory practices entitled D evelopment of measures to assess the safety of existing nuclear power plants and the effectiveness of regulations and regulatory actions (including 'prescriptive' and 'performance based' approaches) . Senior regulators from 23 Member States participated in four peer group discussions during 1995-1996. This report presents the outcome of these meetings and recommendations of good practices identified by these senior regulators. The purpose of this report is to disseminate the views which the senior regulators presented at the meetings relating to measures used for assessing the safety of existing nuclear power plants and evaluating the effectiveness of regulators and regulatory actions. The intention in doing this is to assist Member States in the enhancement of their regulatory practices by identifying commonly accepted good practices. This report is structured so that it covers the subject matter under the following main headings: 'Prescriptive and Performance Based' Approaches to Regulation; Common Features of Regulatory Approaches; Effectiveness of the Regulator and Regulatory Actions; Recommendations of Good Practice. It is important to note that recommendations of good practice are included if they have been identified by at least one of the groups. It does not follow that all of the groups or individual Member States would necessarily endorse all of the recommendations. However, it is considered that if a single group of senior regulators judge that a particular practice is worthy of recommendation then it should be included for serious consideration. In some cases the same recommendations arise from all of the Groups

  4. 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.

  5. 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...

  6. 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.

  7. 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....

  8. 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.

  9. Update of the BIPM.RI(II)-K1.Tc-99m comparison of activity measurements for the radionuclide {sup 99m}Tc to include new results for the LNE-LNHB and the NPL

    Energy Technology Data Exchange (ETDEWEB)

    Michotte, C.; Courte, S.; Ratel, G. [Bureau International des Poids et Mesures (BIPM), 92 - Sevres (France); Moune, M. [LNE-LNHB, Laboratoire national de metrologie et d' essais-Laboratoire National Henri Becquerel, Gif sur Yvette (France); Johansson, L.; Keightley, J. [National Physical Laboratory (NPL), Middlesex (United Kingdom)

    2010-12-15

    In 2007 and 2008 respectively, the Laboratoire national de metrologie et d'essais -Laboratoire national Henri Becquerel (LNE-LNHB), France and the National Physical Laboratory (NPL), UK, submitted ampoules with between 10 MBq and 130 MBq activity of {sup 99m}Tc to the International Reference System (SIR), to update their results in the BIPM.RI(II)-K1.Tc-99m comparison. Together with the four other national metrology institutes (NMI) that are participants, thirteen samples have been submitted since 1983. The key comparison reference value (KCRV) has been recalculated to include the latest primary results of the PTB and the LNE-LNB as this makes the evaluation more robust. The degrees of equivalence between each equivalent activity measured in the SIR are given in the form of a matrix for all six NMIs. A graphical presentation is also given. (authors)

  10. Intracellular pH distribution as a cell health indicator in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Aabo, Thomas; Glückstad, Jesper; Siegumfeldt, Henrik

    2011-01-01

    .d.(pHint)) to describe the internal pH distributions. The cellular pH distributional response to external stress such as heat has not previously been determined. In this study, the intracellular pH (pHi) and the s.d.(pHint) of Saccharomyces cerevisiae cells exposed to supralethal temperatures were measured using...

  11. Open-Source Low-Cost Wireless Potentiometric Instrument for pH Determination Experiments

    Science.gov (United States)

    Jin, Hao; Qin, Yiheng; Pan, Si; Alam, Arif U.; Dong, Shurong; Ghosh, Raja; Deen, M. Jamal

    2018-01-01

    pH determination is an essential experiment in many chemistry laboratories. It requires a potentiometric instrument with extremely low input bias current to accurately measure the voltage between a pH sensing electrode and a reference electrode. In this technology report, we propose an open-source potentiometric instrument for pH determination…

  12. pH within pores in plant fiber cell walls assessed by Fluorescence Ratio Imaging

    DEFF Research Database (Denmark)

    Hidayat, Budi Juliman; Thygesen, Lisbeth Garbrecht; Johansen, Katja Salomon

    2013-01-01

    The pH within cell wall pores of filter paper fibers and hemp fibers was assessed by Fluorescence Ratio Imaging (FRIM). It was found that the Donnan effect affected the pH measured within the fibers. When the conductivity of the added liquid was low (0. 7 mS), pH values were lower within the cell...

  13. The effect of pH profiles in methanogenic aggregates on the kinetics of acetate conversion

    NARCIS (Netherlands)

    Beer, de D.; Huisman, J.W.; Heuvel, van den J.C.; Ottengraf, S.P.P.

    1993-01-01

    Due to the conversion of acetic acid into the weaker carbonic acid and CH4, the pH inside methanogenic aggregates is higher than in the bulk liq. The pH profiles in aggregates were measured with pH microelectrodes. These profiles strongly det. the macro-kinetics of the aggregate, by their influence

  14. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, Spectrophotometer for pH measurement and other instruments from the HESPERIDES in the North Atlantic Ocean from 2003-04-08 to 2003-04-24 (NODC Accession 0108098)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0108098 includes chemical, discrete sample, physical and profile data collected from HESPERIDES in the North Atlantic Ocean from 2003-04-08 to...

  15. 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.

  16. Variation in bacterial ATP concentration during rapid changes in extracellular pH and implications for the activity of attached bacteria.

    Science.gov (United States)

    Albert, Lynal S; Brown, Derick G

    2015-08-01

    In this study we investigated the relationship between a rapid change in extracellular pH and the alteration of bacterial ATP concentration. This relationship is a key component of a hypothesis indicating that bacterial bioenergetics - the creation of ATP from ADP via a proton gradient across the cytoplasmic membrane - can be altered by the physiochemical charge-regulation effect, which results in a pH shift at the bacteria's surface upon adhesion to another surface. The bacterial ATP concentration was measured during a rapid change in extracellular pH from a baseline pH of 7.2 to pH values between 3.5 and 10.5. Experiments were conducted with four neutrophilic bacterial strains, including the Gram-negative Escherichia coli and Pseudomonas putida and the Gram-positive Bacillus subtilis and Staphylococcus epidermidis. A change in bulk pH produced an immediate response in bacterial ATP, demonstrating a direct link between changes in extracellular pH and cellular bioenergetics. In general, the shifts in ATP were similar across the four bacterial strains, with results following an exponential relationship between the extracellular pH and cellular ATP concentration. One exception occurred with S. epidermidis, where there was no variation in cellular ATP at acidic pH values, and this finding is consistent with this species' ability to thrive under acidic conditions. These results provide insight into obtaining a desired bioenergetic response in bacteria through (i) the application of chemical treatments to vary the local pH and (ii) the selection and design of surfaces resulting in local pH modification of attached bacteria via the charge-regulation effect. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Acid skim milk gels: The gelation process as affected by preheated pH

    NARCIS (Netherlands)

    Lakemond, C.M.M.; Vliet, van T.

    2008-01-01

    The effect of preheating milk (10 min 80 [degree sign]C) at pH values from 6.20 to 6.90 on formation of acid skim milk gels was studied by dynamic oscillation measurements. Up to pH 6.65 a higher pH of heating (pHheating) resulted in a higher G'. Since below pH 4.9 the development of

  18. The enhanced cyan fluorescent protein: a sensitive pH sensor for fluorescence lifetime imaging.

    Science.gov (United States)

    Poëa-Guyon, Sandrine; Pasquier, Hélène; Mérola, Fabienne; Morel, Nicolas; Erard, Marie

    2013-05-01

    pH is an important parameter that affects many functions of live cells, from protein structure or function to several crucial steps of their metabolism. Genetically encoded pH sensors based on pH-sensitive fluorescent proteins have been developed and used to monitor the pH of intracellular compartments. The quantitative analysis of pH variations can be performed either by ratiometric or fluorescence lifetime detection. However, most available genetically encoded pH sensors are based on green and yellow fluorescent proteins and are not compatible with multicolor approaches. Taking advantage of the strong pH sensitivity of enhanced cyan fluorescent protein (ECFP), we demonstrate here its suitability as a sensitive pH sensor using fluorescence lifetime imaging. The intracellular ECFP lifetime undergoes large changes (32 %) in the pH 5 to pH 7 range, which allows accurate pH measurements to better than 0.2 pH units. By fusion of ECFP with the granular chromogranin A, we successfully measured the pH in secretory granules of PC12 cells, and we performed a kinetic analysis of intragranular pH variations in living cells exposed to ammonium chloride.

  19. Exhaled breath condensate pH does not discriminate asymptomatic gastroesophageal reflux or the response to lansoprazole treatment in children with poorly controlled asthma.

    Science.gov (United States)

    Fitzpatrick, Anne M; Holbrook, Janet T; Wei, Christine Y; Brown, Meredith S; Wise, Robert A; Teague, W Gerald

    2014-01-01

    Although exhaled breath condensate (EBC) pH has been identified as an "emerging" biomarker of interest for asthma clinical trials, the clinical determinants of EBC pH remain poorly understood. Other studies have associated acid reflux-induced respiratory symptoms, for example, cough, with transient acidification of EBC. We sought to determine the clinical and physiologic correlates of EBC acidification in a highly characterized sample of children with poorly controlled asthma. We hypothesized that (1) children with asymptomatic gastroesophageal reflux determined by 24-hour esophageal pH monitoring would have a lower EBC pH than children without gastroesophageal reflux, (2) treatment with lansoprazole would alter EBC pH in those children, and (3) EBC acidification would be associated with increased asthma symptoms, poorer asthma control and quality of life, and increased formation of breath nitrogen oxides (NOx). A total of 110 children, age range 6 to 17 years, with poor asthma control and esophageal pH data enrolled in the Study of Acid Reflux in Children with Asthma (NCT00442013) were included. Children submitted EBC samples for pH and NOx measurement at randomization and at study weeks 8, 16, and 24. Serial EBC pH measurements failed to distinguish asymptomatic gastroesophageal reflux and was not associated with breath NOx formation. EBC pH also did not discriminate asthma characteristics such as medication and health care utilization, pulmonary function, and asthma control and quality of life both at baseline and across the study period. Despite the relative ease of EBC collection, EBC pH as a biomarker does not provide useful information of children with asthma who were enrolled in asthma clinical trials. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  20. Optical fiber pH sensors for high temperature water. Final report

    International Nuclear Information System (INIS)

    McCrae, D.; Saaski, E.

    1994-11-01

    The goal of this program was the development of an optical pH measurement system capable of operating in a high-temperature aqueous environment. This project built upon a dual-wavelength fiber optic sensing system previously developed by Research International which utilizes light-emitting diodes as light sources and provides remote absorption spectroscopy via a single bidirectional optical fiber. Suitable materials for constructing an optical pH sensing element were identified during the program. These included a sapphire/Ti/Pt/Au thin-film reflector, quartz and sapphire waveguides, a poly(benzimidazole) matrix, and an azo chromophore indicator. By a suitable combination of these design elements, it appears possible to optically measure pH in aqueous systems up to a temperature of about 150 degrees C. A pH sensing system capable of operating in high-purity, low-conductivity water was built using quasi-evanescent wave sensing techniques. The sensing element incorporated a novel, mixed cellulose/cellulose acetate waveguide to which an azo indicator was bound. Testing revealed that the system could reproducibly respond to pH changes arising from 1 ppm differences in the morpholine content of low-conductivity water without influencing the measurement. The sensing system was stable for 150 hrs at room temperature, and no loss or degradation of the pH-responsive optical indicator was seen in 160 hrs at 50 degrees C. However, the prototype polymer waveguide lost transparency at 1.7% per day during this same 50 degrees C test. Additional effort is warranted in the areas of water-compatible waveguides and evanescent-wave detection methods

  1. In Vivo EPR Assessment of pH, pO2, Redox Status, and Concentrations of Phosphate and Glutathione in the Tumor Microenvironment.

    Science.gov (United States)

    Bobko, Andrey A; Eubank, Timothy D; Driesschaert, Benoit; Khramtsov, Valery V

    2018-03-16

    This protocol demonstrates the capability of low-field electron paramagnetic resonance (EPR)-based techniques in combination with functional paramagnetic probes to provide quantitative information on the chemical tumor microenvironment (TME), including pO2, pH, redox status, concentrations of interstitial inorganic phosphate (Pi), and intracellular glutathione (GSH). In particular, an application of a recently developed soluble multifunctional trityl probe provides unsurpassed opportunity for in vivo concurrent measurements of pH, pO2 and Pi in Extracellular space (HOPE probe). The measurements of three parameters using a single probe allow for their correlation analyses independent of probe distribution and time of the measurements.

  2. 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.

  3. 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....

  4. Influence of sodium chloride, pH, and lactic acid bacteria on anaerobic lactic acid utilization during fermented cucumber spoilage.

    Science.gov (United States)

    Johanningsmeier, Suzanne D; Franco, Wendy; Perez-Diaz, Ilenys; McFeeters, Roger F

    2012-07-01

    by spoilage microorganisms in reduced salt, even with pH as low as 3.2. Efforts to reduce salt in commercial brining operations will need to include control measures for this increased susceptibility to spoilage. Lactobacillus buchneri was identified as a potential causative agent and could be used as a target in development of such control measures. Journal of Food Science © 2012 Institute of Food Technologists® No claim to original US government works.

  5. Monitoring the Productivity of Coastal Systems Using PH ...

    Science.gov (United States)

    The impact of nutrient inputs to the eutrophication of coastal ecosystems has been one of the great themes of coastal ecology. There have been countless studies devoted to quantifying how human sources of nutrients, in particular nitrogen (N), effect coastal water bodies. These studies, which often measure in situ concentrations of nutrients, chlorophyll, and dissolved oxygen, are often spatially and/or temporally intensive and expensive. We provide evidence from experimental mesocosms, coupled with data from the water column of a well-mixed estuary, that pH can be a quick, inexpensive, and integrative measure of net ecosystem metabolism. In some cases, this approach is a more sensitive tracer of production than direct measurements of chlorophyll and carbon-14. Taken together, our data suggest that pH is a sensitive, but often overlooked, tool for monitoring estuarine production. This presentation will explore the potential utility of pH as an indicator of ecosystem productivity. Our data suggest that pH is a sensitive and potentially integrator of net ecosystem production. It should not be overlooked, that measuring pH is quick, easy, and inexpensive, further increasing its value as an analytical tool.

  6. Qualitative methods in PhD theses from general practice in Scandinavia

    DEFF Research Database (Denmark)

    Malterud, Kirsti; Hamberg, Katarina; Reventlow, Susanne

    2017-01-01

    . Qualitative studies are often included in Ph.D. theses from general practice in Scandinavia. Still, the Ph.D. programs across nations and institutions offer only limited training in qualitative methods. In this opinion article, we draw upon our observations and experiences, unpacking and reflecting upon...... values and challenges at stake when qualitative studies are included in Ph.D. theses. Hypotheses to explain these observations are presented, followed by suggestions for standards of evaluation and improvement of Ph.D. programs. The authors conclude that multimethod Ph.D. theses should be encouraged...

  7. The pH of beverages in the United States.

    Science.gov (United States)

    Reddy, Avanija; Norris, Don F; Momeni, Stephanie S; Waldo, Belinda; Ruby, John D

    2016-04-01

    Dental erosion is the chemical dissolution of tooth structure in the absence of bacteria when the environment is acidic (pH beverage's erosive potential. In addition, citrate chelation of calcium ions may contribute to erosion at higher pH. The authors of this study determined the erosive potential measured by the pH of commercially available beverages in the United States. The authors purchased 379 beverages from stores in Birmingham, Alabama, and categorized them (for example, juices, sodas, flavored waters, teas, and energy drinks) and assessed their pH. They used a pH meter to measure the pH of each beverage in triplicate immediately after it was opened at a temperature of 25°C. The authors recorded the pH data as mean (standard deviation). Most (93%, 354 of 379) beverages had a pH of less than 4.0, and 7% (25 of 379) had a pH of 4.0 or more. Relative beverage erosivity zones based on studies of apatite solubility in acid indicated that 39% (149 of 379) of the beverages tested in this study were considered extremely erosive (pH beverages in the United States found that most are potentially erosive to the dentition. This study's findings provide dental clinicians and auxiliaries with information regarding the erosive potential of commercially available beverages. Specific dietary recommendations for the prevention of dental erosion may now be developed based on the patient's history of beverage consumption. Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.

  8. 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.

  9. Ratiometric Imaging of Extracellular pH in Dental Biofilms

    DEFF Research Database (Denmark)

    Schlafer, Sebastian; Dige, Irene

    2016-01-01

    The pH in bacterial biofilms on teeth is of central importance for dental caries, a disease with a high worldwide prevalence. Nutrients and metabolites are not distributed evenly in dental biofilms. A complex interplay of sorption to and reaction with organic matter in the biofilm reduces...... the diffusion paths of solutes and creates steep gradients of reactive molecules, including organic acids, across the biofilm. Quantitative fluorescent microscopic methods, such as fluorescence life time imaging or pH ratiometry, can be employed to visualize pH in different microenvironments of dental biofilms...... allows monitoring both vertical and horizontal pH gradients in real-time without mechanically disturbing the biofilm. However, care must be taken to differentiate accurately between extra- and intracellular compartments of the biofilm. Here, the ratiometric dye, seminaphthorhodafluor-4F 5-(and-6...

  10. 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

  11. Measurement

    NARCIS (Netherlands)

    Boumans, M.; Durlauf, S.N.; Blume, L.E.

    2008-01-01

    Measurement theory takes measurement as the assignment of numbers to properties of an empirical system so that a homomorphism between the system and a numerical system is established. To avoid operationalism, two approaches can be distinguished. In the axiomatic approach it is asserted that if the

  12. Quantified pH imaging with hyperpolarized (13) C-bicarbonate.

    Science.gov (United States)

    Scholz, David Johannes; Janich, Martin A; Köllisch, Ulrich; Schulte, Rolf F; Ardenkjaer-Larsen, Jan H; Frank, Annette; Haase, Axel; Schwaiger, Markus; Menzel, Marion I

    2015-06-01

    Because pH plays a crucial role in several diseases, it is desirable to measure pH in vivo noninvasively and in a spatially localized manner. Spatial maps of pH were quantified in vitro, with a focus on method-based errors, and applied in vivo. In vitro and in vivo (13) C mapping were performed for various flip angles for bicarbonate (BiC) and CO2 with spectral-spatial excitation and spiral readout in healthy Lewis rats in five slices. Acute subcutaneous sterile inflammation was induced with Concanavalin A in the right leg of Buffalo rats. pH and proton images were measured 2 h after induction. After optimizing the signal to noise ratio of the hyperpolarized (13) C-bicarbonate, error estimation of the spectral-spatial excited spectrum reveals that the method covers the biologically relevant pH range of 6 to 8 with low pH error (< 0.2). Quantification of pH maps shows negligible impact of the residual bicarbonate signal. pH maps reflect the induction of acute metabolic alkalosis. Inflamed, infected regions exhibit lower pH. Hyperpolarized (13) C-bicarbonate pH mapping was shown to be sensitive in the biologically relevant pH range. The mapping of pH was applied to healthy in vivo organs and interpreted within inflammation and acute metabolic alkalosis models. © 2014 Wiley Periodicals, Inc.

  13. 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 ...

  14. Effects of pH on the toxicity and uptake of [14C]lindane in the midge, Chironomus riparius

    International Nuclear Information System (INIS)

    Fisher, S.W.

    1985-01-01

    The toxicity of the insecticide, lindane, was measured in the midge, Chironomus riparius, at pH 4, 6, and 8 with the finding that lindane is significantly more toxic at pH 6 than at pH 4 and 8. The higher toxicity of lindane at pH 6 is a product of two factors. First the penetration of the compound into the midge is lower at pH 4 than at pH 6 and 8. Second, a greater percentage of total radioactivity is contributed by parent compound at pH 6

  15. Dissolved inorganic carbon, pH and other variables measured from laboratory experiment studies from an experimental carbonate exposure system from 2013-05-15 to 2013-07-12 (NODC Accession 0123316)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains the carbon chemistry measurements of a laboratory experiment study to understand the effects of ocean acidification on winter...

  16. Dissolved inorganic carbon, pH and other variables measured from laboratory experiment studies from an experimental carbonate exposure system from 2013-12-09 to 2014-01-31 (NODC Accession 0123317)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains the carbon chemistry measurements of a laboratory experiment study to understand the effects of ocean acidification on winter...

  17. Dissolved inorganic carbon, pH and other variables measured from laboratory experiment studies from an experimental carbonate exposure system from 2012-02-29 to 2012-05-11 (NODC Accession 0123315)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archival package contains the carbon chemistry measurements of a laboratory experiment study to understand the effects of ocean acidification on winter...

  18. Oceanographic temperature, salinity, oxygen, phosphate, total phosphorus, silicate, nitrite, pH, alkalinity measurements collected using bottle on multiple platforms in the Pacific, Atlantic, Arctic, Mediterranean from 1910 to 1982 (NODC Accession 0038350)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Temperature, salinity, nutrients, oxygen, and other measurements found in dataset OSD taken from the AGASSIZ; A., ALBACORE and other platforms in the Coastal N...

  19. 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...

  20. Evaluation of the relation between lipid coat, transepidermal water loss, and skin pH.

    Science.gov (United States)

    Algiert-Zielińska, Barbara; Batory, Mirella; Skubalski, Janusz; Rotsztejn, Helena

    2017-11-01

    The epidermis is an epidermal barrier which accumulates lipid substances and participates in skin moisturizing. An evaluation of the epidermal barrier efficiency can be made, among others, by the measurement of the following values: the lipid coat, the transepidermal water loss (TEWL) index, and pH. The study involved 50 Caucasian, healthy women aged 19-35 years (mean 20.56). Measurements were made using Courage & Khazaka Multi Probe Adapter MPA 580: Tewameter TM 300, pH-Meter PH 905, Sebumeter SM 815. The areas of measurements included forehead, nose, left cheek, right cheek, chin, and thigh. In the T-zone, the lipid coat was in the range between 0 and 270 μg/cm 2 (mean 128 μg/cm 2 ), TEWL between 1 and 55 g/m 2 /h (mean 11.1 g/m 2 /h), and pH 4.0-5.6 (mean 5.39). Lower values of the lipid coat up to 100 μg/cm 2 were accompanied by TEWL greater than 30 g/m 2 /h and less acidic pH of 5.6-9.0. In the U-zone the range of lipid coat was up to 200 μg/cm 2 (mean 65.2 μg/cm 2 ), the skin pH remained 4.0-5.6 (mean 5.47), and TEWL was in the range between 1 and 20 g/m 2 /h (mean 8.7 g/m 2 /h). Lower values of the lipid coat up to 100 μg/cm 2 were accompanied by TEWL between 1 and 20 g/m 2 /h and less acidic pH of 5.6-9.0. High values of the lipid coat between 180 and 200 μg/cm 2 were connected with TEWL of 1-15 g/m 2 /h. On the skin of the thigh, we observed a very thin lipid coat - 35 μg/cm 2 (mean 5.6 μg/cm 2 ), pH (mean 5.37), and TEWL (mean 8.5 g/m 2 /h) were considered by us to be within regular limits. In the T-zone, a thinner lipid coat resulted in relatively high TEWL and pH levels changing toward alkaline. In the U-zone, thinner lipid coat was accompanied by lower TEWL and pH changing toward alkaline. We also observed that lower values of lipid coat up to 100 μg/cm 2 were associated with higher pH values ranging toward the basic character pH 5.6-9.0). © 2017 The International Society of Dermatology.

  1. Pathways to the PhD in Nursing: An Analysis of Similarities and Differences.

    Science.gov (United States)

    Nehls, Nadine; Barber, Gale; Rice, Elizabeth

    2016-01-01

    New educational pathways are needed to increase the number of doctor of philosophy (PhD)-prepared nurses. To address this need, an early-entry PhD option designed to engage students in PhD coursework and research during the undergraduate nursing major was developed at the University of Wisconsin-Madison. An evaluation comparing the early-entry option with two more conventional entry points was conducted. Three groups (N = 84) comprised the sample: (a) early-entry students admitted as undergraduates or immediately upon graduation (N = 29), (b) mid-entry students with baccalaureate degrees and at least 1 year of work experience (N = 27), and (c) delayed-entry students with master's degrees and 1 or more years of work experience (N = 28). Qualitative and quantitative data were collected from the 3 groups of students who were admitted from 2002 to 2011. The sources of data were transcriptions of individual interviews and reviews of existing data. Seventy-seven percent of the sample participated in the individual interviews. The database review included all students who matriculated into the PhD program. Common themes among the 3 groups included a need for educational funding, the importance of a faculty mentor, and concern about preparation for the teaching role and the academic work environment. The groups were also comparable in terms of research productivity during doctoral study and postgraduation employment. Differences were found on measures of diversity, program progression, and perceptions of clinical competence. The findings provide needed data for the development and expansion of educational pathways to the PhD in nursing. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. 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

  3. Traceability of pH to the Mole

    Directory of Open Access Journals (Sweden)

    Maria Filomena Camões

    2015-08-01

    Full Text Available Free acidity of aqueous solutions was initially defined in 1909 by Søren Peter Lauritz Sørensen as pH = −lgcH+ (c/mol·dm−3 or m/mol·kg−1 of the free hydrogen ions in solution, H+ soon (1910 was changed to pH = paH+ = −lgaH+, integrating the new concepts of activity, ai and activity coefficient γi, for the ionic species i under concern, H+ in this case; it is ai = −lg(miγi. Since individual ions do not exist alone in solution, primary pH values cannot be assigned solely by experimental measurements, requiring extra thermodynamic model assumptions for the activity coefficient, γH+, which has put pH in a unique situation of not being fully traceable to the International System of Units (SI. Also the concept of activity is often not felt to be as perceptible as that of concentration which may present difficulties, namely with the interpretation of data. pH measurements on unknown samples rely on calibration of the measuring setup with adequate reference pH buffers. In this work, the assignment of pH values to buffers closely matching the samples, e.g., seawater, is revisited. An approach is presented to assess the quantity pmH+ = −lgmH+ profiting from the fact that, contrary to single ion activity coefficients, mean activity coefficients,   can be assessed based on experimentally assessed quantities alone, γExp ±, thus ensuring traceability to the mole, the SI base unit for amount of substance. Compatibility between γExp ± and mean activity coefficient calculated by means of Pitzer model equations, γPtz ±, validates the model for its intended use.

  4. Factors that facilitate or inhibit interest of domestic students in the engineering PhD: A mixed methods study

    Science.gov (United States)

    Howell Smith, Michelle C.

    Given the increasing complexity of technology in our society, the United States has a growing demand for a more highly educated technical workforce. Unfortunately, the proportion of United States citizens earning a PhD in engineering has been declining and there is concern about meeting the economic, national security and quality of life needs of our country. This mixed methods sequential exploratory instrument design study identified factors that facilitate or inhibit interest in engineering PhD programs among domestic engineering undergraduate students in the United States. This study developed a testable theory for how domestic students become interested in engineering PhD programs and a measure of that process, the Exploring Engineering Interest Inventory (EEII). The study was conducted in four phases. The first phase of the study was a qualitative grounded theory exploration of interest in the engineering PhD. Qualitative data were collected from domestic engineering students, engineering faculty and industry professional who had earned a PhD in engineering. The second phase, instrument development, developed the Exploring Engineering Interest Inventory (EEII), a measurement instrument designed with good psychometric properties to test a series of preliminary hypotheses related to the theory generated in the qualitative phase. In the third phase of the study, the EEII was used to collect data from a larger sample of junior and senior engineering majors. The fourth phase integrated the findings from the qualitative and quantitative phases. Four factors were identified as being significant influences of interest in the engineering PhD: Personal characteristics, educational environment, misperceptions of the economic and personal costs, and misperceptions of engineering work. Recommendations include increasing faculty encouragement of students to pursue an engineering PhD and programming to correct the misperceptions of the costs of the engineering PhD and the

  5. pH tolerance of Daphnia pulex (leydig, emend. , richard)

    Energy Technology Data Exchange (ETDEWEB)

    Davis, P; Ozburn, G W

    1969-01-01

    The survival time and reproduction of female Daphnia pulex in solutions varying in pH have been observed. Dilute sodium hydroxide or sulfuric acid solutions were added to four different diluent waters: distilled water, aerated tap water, aerated and filtered tap water from an aquarium containing Dace minnows, and Mcintyre River water. D. Pulex (initially up to 72 hours old) survived for the duration of the experiment (32 hours) in river water within a pH range of 6.1 to 10.3; in aquarium water within a pH range of 4.3 to 10.4; only at pH 6.4 and pH 7.6 in distilled water; and in none of the solutions using aerated tap water. The dissolved oxygen content was measured at the beginning and end of every experiment and was found never to fall below 6.2 p.p.M. Those individuals which survived were cultured in the laboratory and parthenogenesis was observed at pH values between 7.0 and 8.7.

  6. Soil pH Mapping with an On-The-Go Sensor

    OpenAIRE

    Schirrmann, Michael; Gebbers, Robin; Kramer, Eckart; Seidel, Jan

    2011-01-01

    Soil pH is a key parameter for crop productivity, therefore, its spatial variation should be adequately addressed to improve precision management decisions. Recently, the Veris pH ManagerTM, a sensor for high-resolution mapping of soil pH at the field scale, has been made commercially available in the US. While driving over the field, soil pH is measured on-the-go directly within the soil by ion selective antimony electrodes. The aim of this study was to evaluate the Veris pH ManagerTM under ...

  7. Clinical Study Monitoring the pH on Tooth Surfaces in Patients with and without Erosion

    OpenAIRE

    Lussi, Adrian; von Salis-Marincek, Maya; Ganss, Carolina; Hellwig, Elmar; Cheaib, Zeinab; Jaeggi, Thomas

    2012-01-01

    The aim of this study was to compare tooth surface pH after drinking orange juice or water in 39 patients with dental erosion and in 17 controls. The following investigations were carried out: measurement of pH values on selected tooth surfaces after ingestion of orange juice followed by ingestion of water (acid clearance), measurement of salivary flow rate and buffering capacity. Compared with the controls, patients with erosion showed significantly greater decreases in pH after drinking ora...

  8. Identification of a molecular pH sensor in coral.

    Science.gov (United States)

    Barott, Katie L; Barron, Megan E; Tresguerres, Martin

    2017-11-15

    Maintaining stable intracellular pH (pHi) is essential for homeostasis, and requires the ability to both sense pH changes that may result from internal and external sources, and to regulate downstream compensatory pH pathways. Here we identified the cAMP-producing enzyme soluble adenylyl cyclase (sAC) as the first molecular pH sensor in corals. sAC protein was detected throughout coral tissues, including those involved in symbiosis and calcification. Application of a sAC-specific inhibitor caused significant and reversible pHi acidosis in isolated coral cells under both dark and light conditions, indicating sAC is essential for sensing and regulating pHi perturbations caused by respiration and photosynthesis. Furthermore, pHi regulation during external acidification was also dependent on sAC activity. Thus, sAC is a sensor and regulator of pH disturbances from both metabolic and external origin in corals. Since sAC is present in all coral cell types, and the cAMP pathway can regulate virtually every aspect of cell physiology through post-translational modifications of proteins, sAC is likely to trigger multiple homeostatic mechanisms in response to pH disturbances. This is also the first evidence that sAC modulates pHi in any non-mammalian animal. Since corals are basal metazoans, our results indicate this function is evolutionarily conserved across animals. © 2017 The Author(s).

  9. Data collection and analysis strategies for phMRI.

    Science.gov (United States)

    Mandeville, Joseph B; Liu, Christina H; Vanduffel, Wim; Marota, John J A; Jenkins, Bruce G

    2014-09-01

    Although functional MRI traditionally has been applied mainly to study changes in task-induced brain function, evolving acquisition methodologies and improved knowledge of signal mechanisms have increased the utility of this method for studying responses to pharmacological stimuli, a technique often dubbed "phMRI". The proliferation of higher magnetic field strengths and the use of exogenous contrast agent have boosted detection power, a critical factor for successful phMRI due to the restricted ability to average multiple stimuli within subjects. Receptor-based models of neurovascular coupling, including explicit pharmacological models incorporating receptor densities and affinities and data-driven models that incorporate weak biophysical constraints, have demonstrated compelling descriptions of phMRI signal induced by dopaminergic stimuli. This report describes phMRI acquisition and analysis methodologies, with an emphasis on data-driven analyses. As an example application, statistically efficient data-driven regressors were used to describe the biphasic response to the mu-opioid agonist remifentanil, and antagonism using dopaminergic and GABAergic ligands revealed modulation of the mesolimbic pathway. Results illustrate the power of phMRI as well as our incomplete understanding of mechanisms underlying the signal. Future directions are discussed for phMRI acquisitions in human studies, for evolving analysis methodologies, and for interpretative studies using the new generation of simultaneous PET/MRI scanners. This article is part of the Special Issue Section entitled 'Neuroimaging in Neuropharmacology'. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Determination of pH by flow-injection analysis and by fiber-optrode analysis

    International Nuclear Information System (INIS)

    Pia, S.H.; Waltman, D.P.; Hillman, D.C.

    1988-07-01

    Two new procedures for measuring pH were developed. The first measures pH colorimetrically using a proprietary indicator-dye mixture in a flow injection analysis (FIA) procedure. The second measures pH using a fiber-optic chemical sensor (FOCS) specifically developed for pH determinations. The FOCS method measures pH by monitoring the fluorescence of a fluorescein derivative bonded to the distal end of a fiber-optic cable called an optrade. The FIA method currently has a precision and accuracy of about + or - 0.2 pH units and can measure 100 samples/hour. The FOCS method has a precision of + or - 0.05-0.20 pH units and an accuracy of + or - 0.1 to 0.6 pH units. About 10 to 60 samples can be analyzed. The characteristics of the FOCS Method will vary significantly with individual optrodes. The experimental results indicate that either flow-injection analysis or fiber optic chemical sensor analysis could form the basis for an alternative to electrometric measurement of pH in certain circumstances

  11. The training, careers, and work of Ph.D. physical scientists: Not simply academic

    Science.gov (United States)

    Smith, Steven J.; Pedersen-Gallegos, Liane; Riegle-Crumb, Catherine

    2002-11-01

    We present an in-depth portrait of the training, careers, and work of recent Ph.D. physical scientists. Use of specialized training varies widely, with about half often using knowledge of their Ph.D. specialty area in their jobs. The use of specialized training does not, however, correlate with job satisfaction. In this and other important measures, there are relatively few differences between "academics" and "nonacademics." Important job skills for all employment sectors include writing, oral presentation, management, data analysis, designing projects, critical thinking, and working in an interdisciplinary context. Rankings given by respondents of graduate training in some of these skill areas were significantly lower than the importance of these skills in the workplace. We also found that the rated quality of graduate training varies relatively little by department or advisor. Finally, although nonacademic aspirations among graduate students are fairly common, these do not appear to be well supported while in graduate school.

  12. Explaining the variation in the shear force of lamb meat using sarcomere length, the rate of rigor onset and pH.

    Science.gov (United States)

    Hopkins, D L; Toohey, E S; Lamb, T A; Kerr, M J; van de Ven, R; Refshauge, G

    2011-08-01

    The temperature when the pH=6.0 (temp@pH6) impacts on the tenderness and eating quality of sheep meat. Due to the expense, sarcomere length is not routinely measured as a variable to explain variation in shear force, but whether measures such as temp@pH6 are as useful a parameter needs to be established. Measures of rigor onset in 261 carcases, including the temp@pH6, were evaluated in this study for their ability to explain some of the variation in shear force. The results show that for 1 day aged product combinations of the temp@pH6, the pH at 18 °C and the pH at 24 h provided a larger reduction (almost double) in total shear force variation than sarcomere length alone, with pH at 24 h being the single best measure. For 5 day aged product, pH at 18 °C was the single best measure. Inclusion of sarcomere length did represent some improvement, but the marginal increase would not be cost effective. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  13. Graphene Channel Liquid Container Field Effect Transistor as ph Sensor

    International Nuclear Information System (INIS)

    Li, X.; Shi, J.; Pang, J.; Liu, W.; Wang, X.; Liu, H.

    2014-01-01

    Graphene channel liquid container field effect transistor ph sensor with interdigital micro trench for liquid ion testing is presented. Growth morphology and ph sensing property of continuous few-layer graphene (FLG) and quasi-continuous monolayer graphene (MG) channels are compared. The experiment results show that the source-to-drain current of the graphene channel FET has a significant and fast response after adsorption of the measured molecule and ion at the room temperature; at the same time, the FLG response time is less than 4 s. The resolution of MG (0.01) on ph value is one order of magnitude higher than that of FLG (0.1). The reason is that with fewer defects, the MG is more likely to adsorb measured molecule and ion, and the molecules and ions can make the transport property change. The output sensitivities of MG are from 34.5% to 57.4% when the ph value is between 7 and 8, while sensitivity of FLG is 4.75% when the Ph=6. The sensor fabrication combines traditional silicon technique and flexible electronic technology and provides an easy way to develop graphene-based electrolyte gas sensor or even biological sensors.

  14. Model-based pH monitor for sensor assessment.

    Science.gov (United States)

    van Schagen, Kim; Rietveld, Luuk; Veersma, Alex; Babuska, Robert

    2009-01-01

    Owing to the nature of the treatment processes, monitoring the processes based on individual online measurements is difficult or even impossible. However, the measurements (online and laboratory) can be combined with a priori process knowledge, using mathematical models, to objectively monitor the treatment processes and measurement devices. The pH measurement is a commonly used measurement at different stages in the drinking water treatment plant, although it is a unreliable instrument, requiring significant maintenance. It is shown that, using a grey-box model, it is possible to assess the measurement devices effectively, even if detailed information of the specific processes is unknown.

  15. Gastroesophageal reflux disease and eosinophilic esophagitis in infants and children. A study of esophageal pH, multiple intraluminal impedance and endoscopic ultrasound

    DEFF Research Database (Denmark)

    Dalby, Kasper; Nielsen, Rasmus; Kruse-Andersen, Søren

    2010-01-01

    Eosinophilic esophagitis (EE) and gastroesophageal reflux disease (GERD) in childhood share aspects of symptomatology. In order to characterize EE and GERD in infants and children with symptoms of GERD we performed a prospective investigation including prolonged esophageal pH measurement, multiple...

  16. pH Sensing and Regulation in Cancer

    Directory of Open Access Journals (Sweden)

    Mehdi eDamaghi

    2013-12-01

    Full Text Available 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. In this review, we will discuss some of the major players in proton sensing at the plasma membrane and their downstream consequences in cancer cells and how these pH-mediated changes affect processes such as migration and metastasis. The complex mechanisms by which they transduce acid pH signals to the cytoplasm and nucleus are not well understood. However, there is evidence that expression of proton-sensing GPCRs such as GPR4, TDAG8, and OGR1 can regulate aspects of tumorigenesis and invasion, including colfilin and talin regulated actin (de-polymerization. Major mechanisms for maintenance of pHi homeostasis include monocarboxylate, bicarbonate and proton transporters. Notably, there is little evidence suggesting a link between their activities and those of the extracellular H+-sensors, suggesting a mechanistic disconnect between intra- and extra-cellular pH. Understanding the mechanisms of pH sensing and regulation may lead to novel and informed therapeutic strategies that can target acidosis, a common physical hallmark of solid tumors.

  17. Measuring $\

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Jessica Sarah [Univ. of Cambridge (United Kingdom)

    2011-01-01

    The MINOS Experiment consists of two steel-scintillator calorimeters, sampling the long baseline NuMI muon neutrino beam. It was designed to make a precise measurement of the ‘atmospheric’ neutrino mixing parameters, Δm2 atm. and sin2 (2 atm.). The Near Detector measures the initial spectrum of the neutrino beam 1km from the production target, and the Far Detector, at a distance of 735 km, measures the impact of oscillations in the neutrino energy spectrum. Work performed to validate the quality of the data collected by the Near Detector is presented as part of this thesis. This thesis primarily details the results of a vμ disappearance analysis, and presents a new sophisticated fitting software framework, which employs a maximum likelihood method to extract the best fit oscillation parameters. The software is entirely decoupled from the extrapolation procedure between the detectors, and is capable of fitting multiple event samples (defined by the selections applied) in parallel, and any combination of energy dependent and independent sources of systematic error. Two techniques to improve the sensitivity of the oscillation measurement were also developed. The inclusion of information on the energy resolution of the neutrino events results in a significant improvement in the allowed region for the oscillation parameters. The degree to which sin2 (2θ )= 1.0 could be disfavoured with the exposure of the current dataset if the true mixing angle was non-maximal, was also investigated, with an improved neutrino energy reconstruction for very low energy events. The best fit oscillation parameters, obtained by the fitting software and incorporating resolution information were: | Δm2| = 2.32+0.12 -0.08×10-3 eV2 and sin2 (2θ ) > 0.90(90% C.L.). The analysis provides the current world best measurement of the atmospheric neutrino mass

  18. Binding of sodium dodecyl sulfate with linear and branched polyethyleneimines in aqueous solution at different pH values.

    Science.gov (United States)

    Wang, Hao; Wang, Yilin; Yan, Haike; Zhang, Jin; Thomas, Robert K

    2006-02-14

    Isothermal titration microcalorimetry (ITC), conductivity, and turbidity measurements have been carried out to study the interaction of sodium dodecyl sulfate (SDS) with polyethyleneimines (PEI) including linear PEI and branched PEI at different pH values of 3, 7, and 10. In all cases, the polymers show a remarkable affinity toward SDS. At pH 3, the polymer PEI is a strong polycation, and the binding is dominated by electrostatic 1:1 charge neutralization with the anionic surfactant. At pH 7, the electrostatic attraction between SDS and PEI is weak, and the hydrophobic interaction becomes stronger. At the natural pH of 10, PEI is essentially nonionic and binds SDS in the form of polymer-bound surfactant aggregates. The charge neutralization concentration (C1) of SDS for the PEI-SDS complex can be derived from the curves of variation of the enthalpy, conductivity, and turbidity with SDS concentration. There is good agreement between the results from the three methods and all show a decrease with increasing pH. The total interaction enthalpies (deltaH(total)) of PEI with SDS are obtained from the observed enthalpy curves and the difference enthalpy (deltaH*) between the total enthalpy of branched PEI with SDS, and the total enthalpy of linear PEI with SDS can be derived from the obtained deltaH(total). The difference deltaH* increases dramatically as pH increases, which indicates that the interactions are different for linear PEI and branched PEI at high pH values. A schematic map of the different states of aggregation is presented.

  19. In situ electrochemical enrichment and isolation of a magnetite-reducing bacterium from a high pH serpentinizing spring.

    Science.gov (United States)

    Rowe, Annette R; Yoshimura, Miho; LaRowe, Doug E; Bird, Lina J; Amend, Jan P; Hashimoto, Kazuhito; Nealson, Kenneth H; Okamoto, Akihiro

    2017-06-01

    Serpentinization is a geologic process that produces highly reduced, hydrogen-rich fluids that support microbial communities under high pH conditions. We investigated the activity of microbes capable of extracellular electron transfer in a terrestrial serpentinizing system known as 'The Cedars'. Measuring current generation with an on-site two-electrode system, we observed daily oscillations in current with the current maxima and minima occurring during daylight hours. Distinct members of the microbial community were enriched. Current generation in lab-scale electrochemical reactors did not oscillate, but was correlated with carbohydrate amendment in Cedars-specific minimal media. Gammaproteobacteria and Firmicutes were consistently enriched from lab electrochemical systems on δ-MnO 2 and amorphous Fe(OH) 3 at pH 11. However, isolation of an electrogenic strain proved difficult as transfer cultures failed to grow after multiple rounds of media transfer. Lowering the bulk pH in the media allowed us to isolate a Firmicutes strain (Paenibacillus sp.). This strain was capable of electrode and mineral reduction (including magnetite) at pH 9. This report provides evidence of the in situ activity of microbes using extracellular substrates as sinks for electrons at The Cedars, but also highlights the potential importance of community dynamics for supporting microbial life through either carbon fixation, and/or moderating pH stress. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  20. Capturing intracellular pH dynamics by coupling its molecular mechanisms within a fully tractable mathematical model.

    Directory of Open Access Journals (Sweden)

    Yann Bouret

    Full Text Available We describe the construction of a fully tractable mathematical model for intracellular pH. This work is based on coupling the kinetic equations depicting the molecular mechanisms for pumps, transporters and chemical reactions, which determine this parameter in eukaryotic cells. Thus, our system also calculates the membrane potential and the cytosolic ionic composition. Such a model required the development of a novel algebraic method that couples differential equations for slow relaxation processes to steady-state equations for fast chemical reactions. Compared to classical heuristic approaches based on fitted curves and ad hoc constants, this yields significant improvements. This model is mathematically self-consistent and allows for the first time to establish analytical solutions for steady-state pH and a reduced differential equation for pH regulation. Because of its modular structure, it can integrate any additional mechanism that will directly or indirectly affect pH. In addition, it provides mathematical clarifications for widely observed biological phenomena such as overshooting in regulatory loops. Finally, instead of including a limited set of experimental results to fit our model, we show examples of numerical calculations that are extremely consistent with the wide body of intracellular pH experimental measurements gathered by different groups in many different cellular systems.

  1. Assessment of the Effect of Fruit (Apple and Plain Yoghurt Consumption on Plaque pH

    Directory of Open Access Journals (Sweden)

    Peyvand Moeiny

    2017-09-01

    Full Text Available Introduction: Nowadays, thanks to improvements in fruit yoghurt tastes, more tendencies are seen in their consumption especially among children. Therefore, their cariogenicity evaluation as healthy snacks is important. The goal of this study was the assessment of the consumption effect of two kinds of Iranian fruit (apple and plain yoghurts on dental plaque PH. Methods: In this experimental study, 10 healthy dentistry students were selected upon inclusion criteria. Plaque pH in the certain areas of the mouth was measured by microelectrode and digital pH meter. PH was measured at the baseline and intervals of 2, 5, 7, 10, 15, 20, 30, 40, 50 and 60 minutes after eating test products: fruit yoghurt (apple and plain Yoghurt. For positive control group, just the baseline PH and at intervals of 2 and 5 min after swishing with 10% sucrose solutions were recorded. The results were analyzed using repeated measures ANOVA. Results: Lowest pH was obtained after fruit yoghurt consumption followed by plain yoghurt and %10 sucrose solution and the plaque PH difference was significant (P=0.05. Furthermore, time duration which remained below the critical pH was longer after consuming fruit yoghurt. Conclusion: Both kinds of yoghurts were considered cariogenic since plaque pH drop below critical points. Average of plaque pH after consuming fruit yoghurt was significantly lower in almost all the time intervals

  2. Field Performance of ISFET based Deep Ocean pH Sensors

    Science.gov (United States)

    Branham, C. W.; Murphy, D. J.

    2017-12-01

    Historically, ocean pH time series data was acquired from infrequent shipboard grab samples and measured using labor intensive spectrophotometry methods. However, with the introduction of robust and stable ISFET pH sensors for use in ocean applications a paradigm shift in the methods used to acquire long-term pH time series data has occurred. Sea-Bird Scientific played a critical role in the adoption this new technology by commercializing the SeaFET pH sensor and float pH Sensor developed by the MBARI chemical sensor group. Sea-Bird Scientific continues to advance this technology through a concerted effort to improve pH sensor accuracy and reliability by characterizing their performance in the laboratory and field. This presentation will focus on calibration of the ISFET pH sensor, evaluate its analytical performance, and validate performance using recent field data.

  3. Fabrication of triple-labeled polyelectrolyte microcapsules for localized ratiometric pH sensing.

    Science.gov (United States)

    Song, Xiaoxue; Li, Huanbin; Tong, Weijun; Gao, Changyou

    2014-02-15

    Encapsulation of pH sensitive fluorophores as reporting molecules provides a powerful approach to visualize the transportation of multilayer capsules. In this study, two pH sensitive dyes (fluorescein and oregon green) and one pH insensitive dye (rhodamine B) were simultaneously labeled on the microcapsules to fabricate ratiometric pH sensors. The fluorescence of the triple-labeled microcapsule sensors was robust and nearly independent of other intracellular species. With a dynamic pH measurement range of 3.3-6.5, the microcapsules can report their localized pH at a real time. Cell culture experiments showed that the microcapsules could be internalized by RAW 246.7 cells naturally and finally accumulated in acidic organelles with a pH value of 5.08 ± 0.59 (mean ± s.d.; n=162). Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Pb and Cd binding to natural freshwater biofilms developed at different pH: the important role of culture pH.

    Science.gov (United States)

    Hua, Xiuyi; Dong, Deming; Ding, Xiaoou; Yang, Fan; Jiang, Xu; Guo, Zhiyong

    2013-01-01

    The effects of solution pH on adsorption of trace metals to different types of natural aquatic solid materials have been studied extensively, but few studies have been carried out to investigate the effect of pH at which the solid materials were formed on the adsorption. The purpose of present study is to examine this effect of culture pH on metal adsorption to natural freshwater biofilms. The adsorption of Pb and Cd to biofilms which were developed at different culture pH values (ranging from 6.5 to 9.0) was measured at the same adsorption pH value (6.5). The culture pH had considerable effects on both composition and metal adsorption ability of the biofilms. Higher culture pH usually promoted the accumulation of organic material and Fe oxides in the biofilms. The culture pH also affected the quantity and species of algae in the biofilms. The adsorption of Pb and Cd to the biofilms generally increased with the increase of culture pH. This increase was minor at lower pH range and significant at higher pH range and was more remarkable for Cd adsorption than for Pb adsorption. The notable contribution of organic material to the adsorption at higher culture pH values was also observed. The profound impacts of culture pH on adsorption behavior of biofilms mainly resulted from the variation of total contents of the biofilm components and were also affected by the alteration of composition and properties of the components.

  5. Measurement of toverline{t} production with additional jet activity, including b quark jets, in the dilepton decay channel using pp collisions at √{s} = 8 {TeV}

    Science.gov (United States)

    Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Knünz, V.; König, A.; Krammer, M.; Krätschmer, I.; Liko, D.; Matsushita, T.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schieck, J.; Schöfbeck, R.; Strauss, J.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Cornelis, T.; de Wolf, E. A.; Janssen, X.; Knutsson, A.; Lauwers, J.; Luyckx, S.; van de Klundert, M.; van Haevermaet, H.; van Mechelen, P.; van Remortel, N.; van Spilbeeck, A.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; Daci, N.; de Bruyn, I.; Deroover, K.; Heracleous, N.; Keaveney, J.; Lowette, S.; Moreels, L.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; van Doninck, W.; van Mulders, P.; van Onsem, G. P.; van Parijs, I.; Barria, P.; Brun, H.; Caillol, C.; Clerbaux, B.; de Lentdecker, G.; Fasanella, G.; Favart, L.; Grebenyuk, A.; Karapostoli, G.; Lenzi, T.; Léonard, A.; Maerschalk, T.; Marinov, A.; Perniè, L.; Randle-Conde, A.; Reis, T.; Seva, T.; Vander Velde, C.; Yonamine, R.; Vanlaer, P.; Yonamine, R.; Zenoni, F.; Zhang, F.; Adler, V.; Beernaert, K.; Benucci, L.; Cimmino, A.; Crucy, S.; Dobur, D.; Fagot, A.; Garcia, G.; Gul, M.; McCartin, J.; Ocampo Rios, A. A.; Poyraz, D.; Ryckbosch, D.; Salva, S.; Sigamani, M.; Strobbe, N.; Tytgat, M.; van Driessche, W.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bondu, O.; Brochet, S.; Bruno, G.; Caudron, A.; Ceard, L.; da Silveira, G. G.; Delaere, C.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Mertens, A.; Musich, M.; Nuttens, C.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Beliy, N.; Hammad, G. H.; Júnior, W. L. Aldá; Alves, F. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Hamer, M.; Hensel, C.; Mora Herrera, C.; Moraes, A.; Pol, M. E.; Rebello Teles, P.; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Custódio, A.; da Costa, E. M.; de Jesus Damiao, D.; de Oliveira Martins, C.; Fonseca de Souza, S.; Huertas Guativa, L. M.; Malbouisson, H.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado da Silva, W. L.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Ahuja, S.; Bernardes, C. A.; de Souza Santos, A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Moon, C. S.; Novaes, S. F.; Padula, Sandra S.; Romero Abad, D.; Ruiz Vargas, J. C.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Cheng, T.; Du, R.; Jiang, C. H.; Plestina, R.; Romeo, F.; Shaheen, S. M.; Spiezia, A.; Tao, J.; Wang, C.; Wang, Z.; Zhang, H.; Asawatangtrakuldee, C.; Ban, Y.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; Gomez Moreno, B.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Puljak, I.; Ribeiro Cipriano, P. M.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Micanovic, S.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Bodlak, M.; Finger, M.; Finger, M.; El Sawy, M.; El-Khateeb, E.; Elkafrawy, T.; Mohamed, A.; Salama, E.; Calpas, B.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Pekkanen, J.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Machet, M.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Zghiche, A.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Chapon, E.; Charlot, C.; Dahms, T.; Davignon, O.; Filipovic, N.; Florent, A.; Granier de Cassagnac, R.; Lisniak, S.; Mastrolorenzo, L.; Miné, P.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Pigard, P.; Regnard, S.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Strebler, T.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Merlin, J. A.; Skovpen, K.; van Hove, P.; Gadrat, S.; Beauceron, S.; Bernet, C.; Boudoul, G.; Bouvier, E.; Carrillo Montoya, C. A.; Chierici, R.; Contardo, D.; Courbon, B.; Depasse, P.; El Mamouni, H.; Fan, J.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Lagarde, F.; Laktineh, I. B.; Lethuillier, M.; Mirabito, L.; Pequegnot, A. L.; Perries, S.; Ruiz Alvarez, J. D.; Sabes, D.; Sgandurra, L.; Sordini, V.; Vander Donckt, M.; Verdier, P.; Viret, S.; Toriashvili, T.; Lomidze, D.; Autermann, C.; Beranek, S.; Edelhoff, M.; Feld, L.; Heister, A.; Kiesel, M. K.; Klein, K.; Lipinski, M.; Ostapchuk, A.; Preuten, M.; Raupach, F.; Schael, S.; Schulte, J. F.; Verlage, T.; Weber, H.; Wittmer, B.; Zhukov, V.; Ata, M.; Brodski, M.; Dietz-Laursonn, E.; Duchardt, D.; Endres, M.; Erdmann, M.; Erdweg, S.; Esch, T.; Fischer, R.; Güth, A.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Klingebiel, D.; Knutzen, S.; Kreuzer, P.; Merschmeyer, M.; Meyer, A.; Millet, P.; Olschewski, M.; Padeken, K.; Papacz, P.; Pook, T.; Radziej, M.; Reithler, H.; Rieger, M.; Scheuch, F.; Sonnenschein, L.; Teyssier, D.; Thüer, S.; Cherepanov, V.; Erdogan, Y.; Flügge, G.; Geenen, H.; Geisler, M.; Hoehle, F.; Kargoll, B.; Kress, T.; Kuessel, Y.; Künsken, A.; Lingemann, J.; Nehrkorn, A.; Nowack, A.; Nugent, I. M.; Pistone, C.; Pooth, O.; Stahl, A.; Aldaya Martin, M.; Asin, I.; Bartosik, N.; Behnke, O.; Behrens, U.; Bell, A. J.; Borras, K.; Burgmeier, A.; Campbell, A.; Choudhury, S.; Costanza, F.; Diez Pardos, C.; Dolinska, G.; Dooling, S.; Dorland, T.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Flucke, G.; Gallo, E.; Garcia, J. Garay; Geiser, A.; Gizhko, A.; Gunnellini, P.; Hauk, J.; Hempel, M.; Jung, H.; Kalogeropoulos, A.; Karacheban, O.; Kasemann, M.; Katsas, P.; Kieseler, J.; Kleinwort, C.; Korol, I.; Lange, W.; Leonard, J.; Lipka, K.; Lobanov, A.; Lohmann, W.; Mankel, R.; Marfin, I.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mittag, G.; Mnich, J.; Mussgiller, A.; Naumann-Emme, S.; Nayak, A.; Ntomari, E.; Perrey, H.; Pitzl, D.; Placakyte, R.; Raspereza, A.; Roland, B.; Sahin, M. Ö.; Saxena, P.; Schoerner-Sadenius, T.; Schröder, M.; Seitz, C.; Spannagel, S.; Trippkewitz, K. D.; Walsh, R.; Wissing, C.; Blobel, V.; Centis Vignali, M.; Draeger, A. R.; Erfle, J.; Garutti, E.; Goebel, K.; Gonzalez, D.; Görner, M.; Haller, J.; Hoffmann, M.; Höing, R. S.; Junkes, A.; Klanner, R.; Kogler, R.; Lapsien, T.; Lenz, T.; Marchesini, I.; Marconi, D.; Meyer, M.; Nowatschin, D.; Ott, J.; Pantaleo, F.; Peiffer, T.; Perieanu, A.; Pietsch, N.; Poehlsen, J.; Rathjens, D.; Sander, C.; Schettler, H.; Schleper, P.; Schlieckau, E.; Schmidt, A.; Schwandt, J.; Sola, V.; Stadie, H.; Steinbrück, G.; Tholen, H.; Troendle, D.; Usai, E.; Vanelderen, L.; Vanhoefer, A.; Vormwald, B.; Akbiyik, M.; Barth, C.; Baus, C.; Berger, J.; Böser, C.; Butz, E.; Chwalek, T.; Colombo, F.; de Boer, W.; Descroix, A.; Dierlamm, A.; Fink, S.; Frensch, F.; Friese, R.; Giffels, M.; Gilbert, A.; Haitz, D.; Hartmann, F.; Heindl, S. M.; Husemann, U.; Katkov, I.; Kornmayer, A.; Lobelle Pardo, P.; Maier, B.; Mildner, H.; Mozer, M. U.; Müller, T.; Müller, Th.; Plagge, M.; Quast, G.; Rabbertz, K.; Röcker, S.; Roscher, F.; Sieber, G.; Simonis, H. J.; Stober, F. M.; Ulrich, R.; Wagner-Kuhr, J.; Wayand, S.; Weber, M.; Weiler, T.; Wöhrmann, C.; Wolf, R.; Anagnostou, G.; Daskalakis, G.; Geralis, T.; Giakoumopoulou, V. A.; Kyriakis, A.; Loukas, D.; Psallidas, A.; Topsis-Giotis, I.; Agapitos, A.; Kesisoglou, S.; Panagiotou, A.; Saoulidou, N.; Tziaferi, E.; Evangelou, I.; Flouris, G.; Foudas, C.; Kokkas, P.; Loukas, N.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Strologas, J.; Bencze, G.; Hajdu, C.; Hazi, A.; Hidas, P.; Horvath, D.; Sikler, F.; Veszpremi, V.; Vesztergombi, G.; Zsigmond, A. J.; Beni, N.; Czellar, S.; Karancsi, J.; Molnar, J.; Szillasi, Z.; Bartók, M.; Makovec, A.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Mal, P.; Mandal, K.; Sahoo, D. K.; Sahoo, N.; Swain, S. K.; Bansal, S.; Beri, S. B.; Bhatnagar, V.; Chawla, R.; Gupta, R.; Bhawandeep, U.; Kalsi, A. K.; Kaur, A.; Kaur, M.; Kumar, R.; Mehta, A.; Mittal, M.; Singh, J. B.; Walia, G.; Kumar, Ashok; Bhardwaj, A.; Choudhary, B. C.; Garg, R. B.; Kumar, A.; Malhotra, S.; Naimuddin, M.; Nishu, N.; Ranjan, K.; Sharma, R.; Sharma, V.; Bhattacharya, S.; Chatterjee, K.; Dey, S.; Dutta, S.; Jain, Sa.; Majumdar, N.; Modak, A.; Mondal, K.; Mukherjee, S.; Mukhopadhyay, S.; Roy, A.; Roy, D.; Roy Chowdhury, S.; Sarkar, S.; Sharan, M.; Abdulsalam, A.; Chudasama, R.; Dutta, D.; Jha, V.; Kumar, V.; Mohanty, A. K.; Pant, L. M.; Shukla, P.; Topkar, A.; Aziz, T.; Banerjee, S.; Bhowmik, S.; Chatterjee, R. M.; Dewanjee, R. K.; Dugad, S.; Ganguly, S.; Ghosh, S.; Guchait, M.; Gurtu, A.; Kole, G.; Kumar, S.; Mahakud, B.; Maity, M.; Majumder, G.; Mazumdar, K.; Mitra, S.; Mohanty, G. B.; Parida, B.; Sarkar, T.; Sur, N.; Sutar, B.; Wickramage, N.; Chauhan, S.; Dube, S.; Sharma, S.; Bakhshiansohi, H.; Behnamian, H.; Etesami, S. M.; Fahim, A.; Goldouzian, R.; Khakzad, M.; Mohammadi Najafabadi, M.; Naseri, M.; Paktinat Mehdiabadi, S.; Rezaei Hosseinabadi, F.; Safarzadeh, B.; Zeinali, M.; Felcini, M.; Grunewald, M.; Abbrescia, M.; Calabria, C.; Caputo, C.; Colaleo, A.; Creanza, D.; Cristella, L.; de Filippis, N.; de Palma, M.; Fiore, L.; Iaselli, G.; Maggi, G.; Miniello, G.; Maggi, M.; My, S.; Nuzzo, S.; Pompili, A.; Pugliese, G.; Radogna, R.; Ranieri, A.; Selvaggi, G.; Silvestris, L.; Venditti, R.; Verwilligen, P.; Abbiendi, G.; Battilana, C.; Benvenuti, A. C.; Bonacorsi, D.; Braibant-Giacomelli, S.; Brigliadori, L.; Campanini, R.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Chhibra, S. S.; Codispoti, G.; Cuffiani, M.; Dallavalle, G. M.; Fabbri, F.; Fanfani, A.; Fasanella, D.; Giacomelli, P.; Grandi, C.; Guiducci, L.; Marcellini, S.; Masetti, G.; Montanari, A.; Navarria, F. L.; Perrotta, A.; Rossi, A. M.; Primavera, F.; Rovelli, T.; Siroli, G. 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F.; Khatiwada, A.; Prosper, H.; Weinberg, M.; Baarmand, M. M.; Bhopatkar, V.; Colafranceschi, S.; Hohlmann, M.; Kalakhety, H.; Noonan, D.; Roy, T.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Bucinskaite, I.; Cavanaugh, R.; Evdokimov, O.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Kurt, P.; O'Brien, C.; Sandoval Gonzalez, L. D.; Silkworth, C.; Turner, P.; Varelas, N.; Wu, Z.; Zakaria, M.; Bilki, B.; Clarida, W.; Dilsiz, K.; Durgut, S.; Gandrajula, R. P.; Haytmyradov, M.; Khristenko, V.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Snyder, C.; Tiras, E.; Wetzel, J.; Yi, K.; Anderson, I.; Anderson, I.; Barnett, B. A.; Blumenfeld, B.; Eminizer, N.; Fehling, D.; Feng, L.; Gritsan, A. V.; Maksimovic, P.; Martin, C.; Osherson, M.; Roskes, J.; Sady, A.; Sarica, U.; Swartz, M.; Xiao, M.; Xin, Y.; You, C.; Xiao, M.; Baringer, P.; Bean, A.; Benelli, G.; Bruner, C.; Kenny, R. P.; Majumder, D.; Majumder, D.; Malek, M.; Murray, M.; Sanders, S.; Stringer, R.; Wang, Q.; Ivanov, A.; Kaadze, K.; Khalil, S.; Makouski, M.; Maravin, Y.; Mohammadi, A.; Saini, L. K.; Skhirtladze, N.; Toda, S.; Lange, D.; Rebassoo, F.; Wright, D.; Anelli, C.; Baden, A.; Baron, O.; Belloni, A.; Calvert, B.; Eno, S. C.; Ferraioli, C.; Gomez, J. A.; Hadley, N. J.; Jabeen, S.; Jabeen, S.; Kellogg, R. G.; Kolberg, T.; Kunkle, J.; Lu, Y.; Mignerey, A. C.; Shin, Y. H.; Skuja, A.; Tonjes, M. B.; Tonwar, S. C.; Apyan, A.; Barbieri, R.; Baty, A.; Bierwagen, K.; Brandt, S.; Bierwagen, K.; Busza, W.; Cali, I. A.; Demiragli, Z.; Di Matteo, L.; Gomez Ceballos, G.; Goncharov, M.; Gulhan, D.; Iiyama, Y.; Innocenti, G. M.; Klute, M.; Kovalskyi, D.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Marini, A. C.; McGinn, C.; Mironov, C.; Narayanan, S.; Niu, X.; Paus, C.; Ralph, D.; Roland, C.; Roland, G.; Salfeld-Nebgen, J.; Stephans, G. S. F.; Sumorok, K.; Varma, M.; Velicanu, D.; Veverka, J.; Wang, J.; Wang, T. W.; Wyslouch, B.; Yang, M.; Zhukova, V.; Dahmes, B.; Evans, A.; Finkel, A.; Gude, A.; Hansen, P.; Kalafut, S.; Kao, S. C.; Klapoetke, K.; Kubota, Y.; Lesko, Z.; Mans, J.; Nourbakhsh, S.; Ruckstuhl, N.; Rusack, R.; Tambe, N.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Bose, S.; Claes, D. R.; Dominguez, A.; Fangmeier, C.; Gonzalez Suarez, R.; Kamalieddin, R.; Keller, J.; Knowlton, D.; Kravchenko, I.; Meier, F.; Monroy, J.; Ratnikov, F.; Siado, J. E.; Snow, G. R.; Alyari, M.; Dolen, J.; George, J.; Godshalk, A.; Harrington, C.; Iashvili, I.; Kaisen, J.; Kharchilava, A.; Kumar, A.; Rappoccio, S.; Roozbahani, B.; Alverson, G.; Barberis, E.; Baumgartel, D.; Chasco, M.; Hortiangtham, A.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; Teixeira de Lima, R.; Trocino, D.; Wang, R.-J.; Wood, D.; Zhang, J.; Hahn, K. A.; Kubik, A.; Mucia, N.; Odell, N.; Pollack, B.; Pozdnyakov, A.; Schmitt, M.; Stoynev, S.; Sung, K.; Trovato, M.; Velasco, M.; Brinkerhoff, A.; Dev, N.; Hildreth, M.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Lynch, S.; Marinelli, N.; Meng, F.; Mueller, C.; Musienko, Y.; Pearson, T.; Planer, M.; Reinsvold, A.; Ruchti, R.; Smith, G.; Taroni, S.; Valls, N.; Wayne, M.; Wolf, M.; Woodard, A.; Antonelli, L.; Brinson, J.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Hart, A.; Hill, C.; Hughes, R.; Ji, W.; Kotov, K.; Ling, T. Y.; Liu, B.; Luo, W.; Puigh, D.; Rodenburg, M.; Winer, B. L.; Wulsin, H. W.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Koay, S. A.; Lujan, P.; Marlow, D.; Medvedeva, T.; Mooney, M.; Olsen, J.; Palmer, C.; Piroué, P.; Saka, H.; Stickland, D.; Tully, C.; Zuranski, A.; Malik, S.; Barnes, V. E.; Benedetti, D.; Bortoletto, D.; Gutay, L.; Jha, M. K.; Jones, M.; Jung, K.; Miller, D. H.; Neumeister, N.; Primavera, F.; Radburn-Smith, B. C.; Shi, X.; Shipsey, I.; Silvers, D.; Sun, J.; Svyatkovskiy, A.; Wang, F.; Xie, W.; Xu, L.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Chen, Z.; Ecklund, K. M.; Geurts, F. J. M.; Guilbaud, M.; Li, W.; Michlin, B.; Northup, M.; Padley, B. P.; Redjimi, R.; Roberts, J.; Rorie, J.; Tu, Z.; Zabel, J.; Betchart, B.; Bodek, A.; de Barbaro, P.; Demina, R.; Eshaq, Y.; Ferbel, T.; Galanti, M.; Galanti, M.; Garcia-Bellido, A.; Han, J.; Harel, A.; Hindrichs, O.; Hindrichs, O.; Khukhunaishvili, A.; Petrillo, G.; Tan, P.; Verzetti, M.; Arora, S.; Barker, A.; Chou, J. P.; Contreras-Campana, C.; Contreras-Campana, E.; Duggan, D.; Ferencek, D.; Gershtein, Y.; Gray, R.; Halkiadakis, E.; Hidas, D.; Hughes, E.; Kaplan, S.; Kunnawalkam Elayavalli, R.; Lath, A.; Nash, K.; Panwalkar, S.; Park, M.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Foerster, M.; Riley, G.; Rose, K.; Spanier, S.; York, A.; Bouhali, O.; Castaneda Hernandez, A.; Dalchenko, M.; de Mattia, M.; Delgado, A.; Dildick, S.; Dildick, S.; Eusebi, R.; Gilmore, J.; Kamon, T.; Krutelyov, V.; Krutelyov, V.; Mueller, R.; Osipenkov, I.; Pakhotin, Y.; Patel, R.; Patel, R.; Perloff, A.; Rose, A.; Safonov, A.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Cowden, C.; Damgov, J.; Dragoiu, C.; Dudero, P. R.; Faulkner, J.; Kunori, S.; Lamichhane, K.; Lee, S. W.; Libeiro, T.; Undleeb, S.; Volobouev, I.; Appelt, E.; Delannoy, A. G.; Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Mao, Y.; Melo, A.; Ni, H.; Sheldon, P.; Snook, B.; Tuo, S.; Velkovska, J.; Xu, Q.; Arenton, M. W.; Cox, B.; Francis, B.; Goodell, J.; Hirosky, R.; Ledovskoy, A.; Li, H.; Lin, C.; Neu, C.; Sinthuprasith, T.; Sun, X.; Wang, Y.; Wolfe, E.; Wood, J.; Xia, F.; Clarke, C.; Harr, R.; Karchin, P. E.; Kottachchi Kankanamge Don, C.; Lamichhane, P.; Sturdy, J.; Belknap, D. A.; Carlsmith, D.; Cepeda, M.; Dasu, S.; Dodd, L.; Duric, S.; Gomber, B.; Grothe, M.; Hall-Wilton, R.; Herndon, M.; Hervé, A.; Klabbers, P.; Lanaro, A.; Levine, A.; Long, K.; Loveless, R.; Mohapatra, A.; Ojalvo, I.; Perry, T.; Pierro, G. A.; Polese, G.; Ruggles, T.; Sarangi, T.; Savin, A.; Sharma, A.; Smith, N.; Smith, W. H.; Taylor, D.; Woods, N.; CMS Collaboration

    2016-07-01

    Jet multiplicity distributions in top quark pair ({t}{overline{t}}) events are measured in pp collisions at a centre-of-mass energy of 8 TeV with the CMS detector at the LHC using a data set corresponding to an integrated luminosity of 19.7 {fb}^ {-1}. The measurement is performed in the dilepton decay channels (e^+e^-, μ^+ μ^-, and e^{±} μ^{∓}). The absolute and normalized differential cross sections for {t}overline{t} production are measured as a function of the jet multiplicity in the event for different jet transverse momentum thresholds and the kinematic properties of the leading additional jets. The differential {t overline{t} b} and {t overline{t} b overline{b}} cross sections are presented for the first time as a function of the kinematic properties of the leading additional b jets. Furthermore, the fraction of events without additional jets above a threshold is measured as a function of the transverse momenta of the leading additional jets and the scalar sum of the transverse momenta of all additional jets. The data are compared and found to be consistent with predictions from several perturbative quantum chromodynamics event generators and a next-to-leading order calculation.

  6. PH5 for integrating and archiving different data types

    Science.gov (United States)

    Azevedo, Steve; Hess, Derick; Beaudoin, Bruce

    2016-04-01

    PH5 is IRIS PASSCAL's file organization of HDF5 used for seismic data. The extensibility and portability of HDF5 allows the PH5 format to evolve and operate on a variety of platforms and interfaces. To make PH5 even more flexible, the seismic metadata is separated from the time series data in order to achieve gains in performance as well as ease of use and to simplify user interaction. This separation affords easy updates to metadata after the data are archived without having to access waveform data. To date, PH5 is currently used for integrating and archiving active source, passive source, and onshore-offshore seismic data sets with the IRIS Data Management Center (DMC). Active development to make PH5 fully compatible with FDSN web services and deliver StationXML is near completion. We are also exploring the feasibility of utilizing QuakeML for active seismic source representation. The PH5 software suite, PIC KITCHEN, comprises in-field tools that include data ingestion (e.g. RefTek format, SEG-Y, and SEG-D), meta-data management tools including QC, and a waveform review tool. These tools enable building archive ready data in-field during active source experiments greatly decreasing the time to produce research ready data sets. Once archived, our online request page generates a unique web form and pre-populates much of it based on the metadata provided to it from the PH5 file. The data requester then can intuitively select the extraction parameters as well as data subsets they wish to receive (current output formats include SEG-Y, SAC, mseed). The web interface then passes this on to the PH5 processing tools to generate the requested seismic data, and e-mail the requester a link to the data set automatically as soon as the data are ready. PH5 file organization was originally designed to hold seismic time series data and meta-data from controlled source experiments using RefTek data loggers. The flexibility of HDF5 has enabled us to extend the use of PH5 in several

  7. Development of a fluorescence endoscopic system for pH mapping of gastric tissue

    Science.gov (United States)

    Rochon, Philippe; Mordon, Serge; Buys, Bruno; Dhelin, Guy; Lesage, Jean C.; Chopin, Claude

    2003-10-01

    Measurement of gastro intestinal intramucosal pH (pHim) has been recognized as an important factor in the detection of hypoxia induced dysfonctions. However, current pH measurements techniques are limited in terms of time and spatial resolutions. A major advance in accurate pH measurement was the development of the ratiometric fluorescent indicator dye, 2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF). BCECF which pKa is in the physiological pH range is suitable for pH tissue measurements in vivo. This study aimed to develop and evaluate an endoscopic imaging system for real time pH measurements in the stomach in order to provide to ICU a new tool for gastro intestinal intramucosal pH (pHim) measurements. This fluorescence imaging technique should allow the temporal exploration of sequential events, particularly in ICU where the pHim provides a predictive information of the patient' status. The experimental evaluations of this new and innovative endoscopic fluorescence system confirms the accuracy of pH measurement using BCECF.

  8. Graphite Screen-Printed Electrodes Applied for the Accurate and Reagentless Sensing of pH.

    Science.gov (United States)

    Galdino, Flávia E; Smith, Jamie P; Kwamou, Sophie I; Kampouris, Dimitrios K; Iniesta, Jesus; Smith, Graham C; Bonacin, Juliano A; Banks, Craig E

    2015-12-01

    A reagentless pH sensor based upon disposable and economical graphite screen-printed electrodes (GSPEs) is demonstrated for the first time. The voltammetric pH sensor utilizes GSPEs which are chemically pretreated to form surface immobilized oxygenated species that, when their redox behavior is monitored, give a Nernstian response over a large pH range (1-13). An excellent experimental correlation is observed between the voltammetric potential and pH over the entire pH range of 1-13 providing a simple approach with which to monitor solution pH. Such a linear response over this dynamic pH range is not usually expected but rather deviation from linearity is encountered at alkaline pH values; absence of this has previously been attributed to a change in the pKa value of surface immobilized groups from that of solution phase species. This non-deviation, which is observed here in the case of our facile produced reagentless pH sensor and also reported in the literature for pH sensitive compounds immobilized upon carbon electrodes/surfaces, where a linear response is observed over the entire pH range, is explained alternatively for the first time. The performance of the GSPE pH sensor is also directly compared with a glass pH probe and applied to the measurement of pH in "real" unbuffered samples where an excellent correlation between the two protocols is observed validating the proposed GSPE pH sensor.

  9. The oxygen sensitivity of a multipoint antimony electrode for tissue pH measurements. A study of the sensitivity for in vivo PO2 variations below 6 kPa.

    Science.gov (United States)

    Sjöberg, F; Edwall, G; Lund, N

    1987-02-01

    Monocrystalline micro antimony electrodes in a multipoint arrangement as described by Lund et al. were placed on the skeletal muscle surface of the rabbit. Tissue oxygen levels were measured simultaneously with the MDO (Mehrdraht Dortmund Oberfläche) oxygen electrode. The sensitivity for variations in tissue PO2 (PO2(t)) was evaluated for the antimony metal-metal oxide sensor. The sensitivity (delta E/delta log10 PO2)+/- SE was found to be 21.8 +/- 1.2 mV in the interval between 0.1 kPa and 1 kPa and 53 +/- 5 mV in the interval between 1 kPa and 6 kPa. These results are not consistent with the oxygen sensitivity of monocrystalline antimony described in vitro, but are in agreement with the findings of Nilsson & Edwall. A plausible explanation for the S-shaped oxygen sensitivity curve of antimony at oxygen levels below 10 kPa could be an interaction, at the electrode surface, between the dissolved oxygen and the oxygen bound to haemoglobin. If this is the case, the use of an antimony electrode would make possible the determination of the dissociation of oxyhaemoglobin in tissues.

  10. A New Experiment for the Measurement of nJ(C,P) Coupling Constants Including 3J(C4'i,Pi) and 3J(C4'i,Pi+1) in Oligonucleotides

    International Nuclear Information System (INIS)

    Richter, Christian; Reif, Bernd; Woerner, Karlheinz; Quant, Stefanie; Marino, John P.; Engels, Joachim W.; Griesinger, Christian; Schwalbe, Harald

    1998-01-01

    A new experiment for the measurement of nJ(C,P) coupling constants along the phosphodiester backbone in RNA and DNA based on a quantitative-J HCP experiment is presented. In addition to coupling constants, in which a carbon atom couples to only one phosphorus atom, both the intraresidual 3J(C4'i,Pi) and the sequential 3J(C4'i,Pi+1) for the C4' resonances that couple to two phosphorus atoms can be obtained. Coupling constants obtained by this new method are compared to values obtained from the P-FIDS experiment. Together with 3J(H,P) coupling constants measured using the P-FIDS experiment, the backbone angles β and element of can be determined

  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...... over the optic nerve in the eyes of domestic pigs....

  12. The importance of dietary composition for efficacy of iron absorption measured in a whole diet that includes rye bread fortified with ferrous fumerate: A radioisotope study in young women

    DEFF Research Database (Denmark)

    Tetens, Inge; Larsen, T.M.; Kristensen, M.B.

    2005-01-01

    randomised to three groups, each of which was given two of six test diets containing either low/high amounts of vitamin C, meat or phytic acid, respectively, in a cross-over design. Each diet was served throughout a 5 d period. Fe-fortified rye bread, extrinsically labelled with Fe-59, was given with all......Fe absorption is affected by many dietary factors. The objective of the present study was to measure the effects of high v. low content of vitamin C, meat and phytic acid in whole diets with Fe-fortified bread on the efficacy of Fe absorption. Thirty-two healthy women with low Fe stores were...... main meals. Fe absorption was determined from whole-body counter measurements of Fe-59 retention. The fractional non-haem Fe absorption (corrected to a 40 % standard absorption by measurements from the reference dose) was 1.9% v. 3.4% (P=0.04) for the low/high vitamin C diets, 3.0% v. 3.5% (P=0...

  13. Imidazole as a pH Probe: An NMR Experiment for the General Chemistry Laboratory

    Science.gov (United States)

    Hagan, William J., Jr.; Edie, Dennis L.; Cooley, Linda B.

    2007-01-01

    The analysis describes an NMR experiment for the general chemistry laboratory, which employs an unknown imidazole solution to measure the pH values. The described mechanism can also be used for measuring the acidity within the isolated cells.

  14. Salivary pH levels and caries among siblings and parents within families.

    Science.gov (United States)

    Basch, Yaffa; Peretz, Benjamin

    2013-01-01

    High level of caries activity is related to organisms in the dental plaque with high acidogenesis capacity. To test salivary pH in children of the same family and compare it with their caries status. To compare pH levels between children and their parents. To examine the relationship between pH and caries status among children of the same family and their parents. We examined 123 children and adolescents aged 3-18, (73 boys and 50 girls) and 33 adults, (12 men and 21 women), parents of these children. Caries status was examined clinically, using DMF index. Salivary pH measurements were made by a digital pH meter. Among adults, increase in patient age led to increased DMF (p = 0.005). The higher the pH, the lower the DMF (p = 0.037). Among men, DMF was lower by 3 compared to women (p = 0.049). Children's pH correlated with the parents' (p = 0.004). Children's DMF correlated to their pH (p = 0.001). Children's pH was the best predictor of their DMF (R2 = 0.309, p = 0.001). Among children, the higher the pH, the lower the DMFT. Children's pH was the best predictor of their DMF.

  15. A protein-dye hybrid system as a narrow range tunable intracellular pH sensor.

    Science.gov (United States)

    Anees, Palapuravan; Sudheesh, Karivachery V; Jayamurthy, Purushothaman; Chandrika, Arunkumar R; Omkumar, Ramakrishnapillai V; Ajayaghosh, Ayyappanpillai

    2016-11-18

    Accurate monitoring of pH variations inside cells is important for the early diagnosis of diseases such as cancer. Even though a variety of different pH sensors are available, construction of a custom-made sensor array for measuring minute variations in a narrow biological pH window, using easily available constituents, is a challenge. Here we report two-component hybrid sensors derived from a protein and organic dye nanoparticles whose sensitivity range can be tuned by choosing different ratios of the components, to monitor the minute pH variations in a given system. The dye interacts noncovalently with the protein at lower pH and covalently at higher pH, triggering two distinguishable fluorescent signals at 700 and 480 nm, respectively. The pH sensitivity region of the probe can be tuned for every unit of the pH window resulting in custom-made pH sensors. These narrow range tunable pH sensors have been used to monitor pH variations in HeLa cells using the fluorescence imaging technique.

  16. [pH values in the pharynx of the patients presenting with compromised nasal breathing of inflammatory and non-inflammatory genesis concomitant with gastroesophageal reflux disease].

    Science.gov (United States)

    Subbotina, M V; Temnikova, I V; Onuchina, E V

    2015-01-01

    The objective of the present study was to estimate the influence of gastroesophageal reflux disease (GERD) on the pH values in the pharynx and nose. It included 87 patients at the age varying from 18 to 81 years admitted to the Irkutsk-based Railway Clinical Hospital and allocated to four groups. Group 1 was comprised of 25 patients presenting with gastroesophageal reflux disease and chronic rhinosinusitis (CRS), group 2 consisted of 29 patients with CRS in the absence of GERD, group 3 included 22 patients with nasal septum deformations (NSD) and GERD, group 4 included 11 patients with NSD and motor rhinitis without GERD. The control group was formed from 10 volunteers. pH was measured by the contact method with the use ofEkokhim indicator paper. Gastroesophageal reflux disease was diagnosed following the recommendations of the Montreal consensus. It was shown that pH values in the pharynx of the patients with compromised nasal breathing of any origin in combination with GERD were lower than in the absence of GERD and in the healthy volunteers. The study groups did not differ in terms of pH values in the nasal cavity. It is concluded that pH values 4 or lower may serve as the criterion for pharyngo-laryngeal reflux (PLR) concomitant with HERD while pH 5 occurs more frequently in the patients with compromised nasal breathing of any etiology, regardless of the presence or absence of GERD.Disordered nasal breathing of any genesis in the patients presenting with gastroesophageal reflux disease was associated with the feeling of the lump in the throat, congestion of the respiratory tract and the nose, pain in the ears, cardialgia, and irregular heartbeat. It isrecommended to use pH measurements as a criterion for diagnostics of pharyngo-laryngeal reflux in the patients presenting with gastroesophageal reflux disease.

  17. Digestion products of the PH20 hyaluronidase inhibit remyelination.

    Science.gov (United States)

    Preston, Marnie; Gong, Xi; Su, Weiping; Matsumoto, Steven G; Banine, Fatima; Winkler, Clayton; Foster, Scott; Xing, Rubing; Struve, Jaime; Dean, Justin; Baggenstoss, Bruce; Weigel, Paul H; Montine, Thomas J; Back, Stephen A; Sherman, Larry S

    2013-02-01

    Oligodendrocyte progenitor cells (OPCs) recruited to demyelinating lesions often fail to mature into oligodendrocytes (OLs) that remyelinate spared axons. The glycosaminoglycan hyaluronan (HA) accumulates in demyelinating lesions and has been implicated in the failure of OPC maturation and remyelination. We tested the hypothesis that OPCs in demyelinating lesions express a specific hyaluronidase, and that digestion products of this enzyme inhibit OPC maturation. Mouse OPCs grown in vitro were analyzed for hyaluronidase expression and activity. Gain of function studies were used to define the hyaluronidases that blocked OPC maturation. Mouse and human demyelinating lesions were assessed for hyaluronidase expression. Digestion products from different hyaluronidases and a hyaluronidase inhibitor were tested for their effects on OPC maturation and functional remyelination in vivo. OPCs demonstrated hyaluronidase activity in vitro and expressed multiple hyaluronidases, including HYAL1, HYAL2, and PH20. HA digestion by PH20 but not other hyaluronidases inhibited OPC maturation into OLs. In contrast, inhibiting HA synthesis did not influence OPC maturation. PH20 expression was elevated in OPCs and reactive astrocytes in both rodent and human demyelinating lesions. HA digestion products generated by the PH20 hyaluronidase but not another hyaluronidase inhibited remyelination following lysolecithin-induced demyelination. Inhibition of hyaluronidase activity lead to increased OPC maturation and promoted increased conduction velocities through lesions. We determined that PH20 is elevated in demyelinating lesions and that increased PH20 expression is sufficient to inhibit OPC maturation and remyelination. Pharmacological inhibition of PH20 may therefore be an effective way to promote remyelination in multiple sclerosis and related conditions. Copyright © 2012 American Neurological Association.

  18. Effect of pH on sludge composting

    International Nuclear Information System (INIS)

    Hashimoto, Shoji; Watanabe, Hiromasa; Nishimura, Koichi; Kawakami, Waichiro

    1984-01-01

    The effect of pH on composting of irradiated sewage sludge was discussed. Inorganic materials, such as activated alumina, Kanuma-soil, and Akadama-soil, were used as bulking agents. Na 2 CO 3 was used as a pH adjuster. The fermentations were done isothermally at the optimum temperature, 50 0 C. The rate of CO 2 evolution increased initially with time, and then, decreased. The peak value of CO 2 evolution and the time to attain the peak varied by the addition of Na 2 CO 3 . When Kanuma-soil was used as the bulking agent, for example, the peak value became larger as the amount of Na 2 CO 3 was increased to 1.0 % and became smaller over this value. From pH measurements, it was found that the optimum pH for fermentation was ranged from 6 to 8 when activated alumina was used. When other bulking agents were used, the maximum value of CO 2 evolution rate was obtained at pH 7 to 8.5. The peak value and the peak time also varied by the addition of NH 3 in the aeration gas. (author)

  19. Chemical Composition and Evaluation of Nicotine, Tobacco Alkaloids, pH and Selected Flavors in e-Cigarette Cartridges and Refill Solutions

    Science.gov (United States)

    Lisko, Joseph G.; Tran, Hang; Stanfill, Stephen B.; Blount, Benjamin C.; Watson, Clifford H.

    2015-01-01

    Introduction Electronic cigarette (e-cigarette) use is increasing dramatically in developed countries, but little is known about these rapidly evolving products. This study analyzed and evaluated the chemical composition including nicotine, tobacco alkaloids, pH and flavors in 36 e-liquids brands from four manufacturers. Methods We determined the concentrations of nicotine, alkaloids, and select flavors and measured pH in solutions used in e-cigarettes. E-cigarette products were chosen based upon favorable consumer approval ratings from online review websites. Quantitative analyses were performed using strict quality assurance/quality control (QC) validated methods previously established by our lab for the measurement of nicotine, alkaloids, pH and flavors. Results Three-quarters of the products contained lower measured nicotine levels than the stated label values (6% - 42% by concentration). The pH for e-liquids ranged from 5.1 – 9.1. Minor tobacco alkaloids were found in all samples containing nicotine, and their relative concentrations varied widely among manufacturers. A number of common flavor compounds were analyzed in all e-liquids. Conclusions Free nicotine levels calculated from the measurement of pH correlated with total nicotine content. The direct correlation between the total nicotine concentration and pH suggests that the alkalinity of nicotine drives the pH of e-cigarette solutions. A higher percentage of nicotine exists in the more absorbable free form as total nicotine concentration increases. A number of products contained tobacco alkaloids at concentrations that exceed U.S. Pharmacopeia limits for impurities in nicotine used in pharmaceutical and food products. PMID:25636907

  20. Chemical Composition and Evaluation of Nicotine, Tobacco Alkaloids, pH, and Selected Flavors in E-Cigarette Cartridges and Refill Solutions.

    Science.gov (United States)

    Lisko, Joseph G; Tran, Hang; Stanfill, Stephen B; Blount, Benjamin C; Watson, Clifford H

    2015-10-01

    Electronic cigarette (e-cigarette) use is increasing dramatically in developed countries, but little is known about these rapidly evolving products. This study analyzed and evaluated the chemical composition including nicotine, tobacco alkaloids, pH, and flavors in 36 e-liquids brands from 4 manufacturers. We determined the concentrations of nicotine, alkaloids, and select flavors and measured pH in solutions used in e-cigarettes. E-cigarette products were chosen based upon favorable consumer approval ratings from online review websites. Quantitative analyses were performed using strict quality assurance/quality control validated methods previously established by our lab for the measurement of nicotine, alkaloids, pH, and flavors. Three-quarters of the products contained lower measured nicotine levels than the stated label values (6%-42% by concentration). The pH for e-liquids ranged from 5.1-9.1. Minor tobacco alkaloids were found in all samples containing nicotine, and their relative concentrations varied widely among manufacturers. A number of common flavor compounds were analyzed in all e-liquids. Free nicotine levels calculated from the measurement of pH correlated with total nicotine content. The direct correlation between the total nicotine concentration and pH suggests that the alkalinity of nicotine drives the pH of e-cigarette solutions. A higher percentage of nicotine exists in the more absorbable free form as total nicotine concentration increases. A number of products contained tobacco alkaloids at concentrations that exceed U.S. pharmacopeia limits for impurities in nicotine used in pharmaceutical and food products. © Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  1. Effect of habitual arecanut chewing on resting whole mouth salivary flow rate and pH

    OpenAIRE

    Rooban T; Mishra G; Elizabeth J; Ranganathan K; Saraswathi T

    2006-01-01

    BACKGROUND: Resting whole mouth salivary flow rate (SFR) and pH play a significant role in pathogenesis of various oral diseases and conditions. AIM: To observe the effect of habitual use of arecanut and various arecanut containing products (AN) on SFR and pH. DESIGN: Cross sectional. SETTING: Outpatient Department of Dental College. PARTICIPANTS: AN chewers and non-chewers attending Dental college. MEASUREMENTS: SFR and pH. VARIABLES: Type, frequency, duration and exposure time of AN, Smokin...

  2. Nanowire-templated microelectrodes for high-sensitivity pH detection

    DEFF Research Database (Denmark)

    Antohe, V.A.; Radu, Adrian; Mátéfi-Tempfli, Mária

    2009-01-01

    A highly sensitive pH capacitive sensor has been designed by confined growth of vertically aligned nanowire arrays on interdigited microelectrodes. The active surface of the device has been functionalized with an electrochemical pH transducer (polyaniline). We easily tune the device features...... by combining lithographic techniques with electrochemical synthesis. The reported electrical LC resonance measurements show considerable sensitivity enhancement compared to conventional capacitive pH sensors realized with microfabricated interdigited electrodes. The sensitivity can be easily improved...

  3. [Molecular genetics in chronic myeloid leukemia with variant Ph translocation].

    Science.gov (United States)

    Wu, Wei; Li, Jian-yong; Zhu, Yu; Qiu, Hai-rong; Pan, Jin-lan; Xu, Wei; Chen, Li-juan; Shen, Yun-feng; Xue, Yong-quan

    2007-08-01

    To explore the value of fluorescence in situ hybridization (FISH) and multiplex fluorescence in situ hybridization (M-FISH) techniques in the detection of genetic changes in chronic myeloid leukemia (CML) with variant Philadelphia translocation (vPh). Cytogenetic preparations from 10 CML patients with vPh confirmed by R banding were assayed with dual color dual fusion FISH technique. If only one fusion signal was detected in interphase cells, metaphase cells were observed to determine if there were derivative chromosome 9[der (9)] deletions. Meanwhile, the same cytogenetic preparations were assayed with M-FISH technique. Of the 10 CML patients with vPh, 5 were detected with der (9) deletions by FISH technique. M-FISH technique revealed that besides the chromosome 22, chromosomes 1, 3, 5, 6, 8, 10, 11 and 17 were also involved in the vPh. M-FISH technique also detected the abnormalities which were not found with conventional cytogenetics (CC), including two never reported abnormalities. The combination of CC, FISH and M-FISH technique could refine the genetic diagnosis of CML with vPh.

  4. Proceedings of the ICTSS 2012 PhD Workshop - Preface

    DEFF Research Database (Denmark)

    Nielsen, Brian; Weise, Carsten

    2012-01-01

    and their thesis work and receive constructive feedback from experts in the field as well as from peers. Also it is an opportunity for researchers to get an insight into new research topics in the field. Ph.D. students at any stage of their doctoral studies may participate. Seven abstracts were submitted......This technical report contains the proceedings of the Ph.D. Workshop held in conjunction with the The 24th IFIP Int. Conference on Testing Software and Systems (ICTSS'12) in Aalborg, Denmark, November 19, 2012. The well‐established ICTSS series of international conferences addresses the conceptual......, theoretic, and practical challenges of testing software systems, including communication protocols, services, distributed platforms, middleware, embedded systems, and security infrastructures. The aims of the ICTSS Doctoral Workshop is to provide a forum for PhD students to present preliminary results...

  5. Direct reduction of N-acetoxy-PhIP by tea polyphenols: a possible mechanism for chemoprevention against PhIP-DNA adduct formation

    International Nuclear Information System (INIS)

    Lin Dongxin; Thompson, Patricia A.; Teitel, Candee; Chen Junshi; Kadlubar, Fred F.

    2003-01-01

    The chemopreventive effect of tea against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-DNA adduct formation and its mechanism were studied. Rats were exposed to freshly prepared aqueous extracts of green tea (3% (w/v)) as the sole source of drinking water for 10 days prior to administration with a single dose of PhIP (10 mg/kg body weight) by oral gavage. PhIP-DNA adducts in the liver, colon, heart, and lung were measured using the 32 P-postlabelling technique. Rats pre-treated with tea and given PhIP 20 h before sacrifice had significantly reduced levels of PhIP-DNA adducts as compared with controls given PhIP alone. The possible mechanism of protective effect of tea on PhIP-DNA adduct formation was then examined in vitro. It was found that an aqueous extract of green and black tea, mixtures of green and black tea polyphenols, as well as purified polyphenols could strongly inhibit the DNA binding of N-acetoxy-PhIP, a putative ultimate carcinogen of PhIP formed in vivo via metabolic activation. Among these, epigallocatechin gallate was exceptionally potent. HPLC analyses of these incubation mixtures containing N-acetoxy-PhIP and the tea polyphenols each revealed the production of the parent amine, PhIP, indicating the involvement of a redox mechanism. In view of the presence of relatively high levels of tea polyphenols in rat and human plasma after ingestion of tea, this study suggests that direct reduction of the ultimate carcinogen N-acetoxy-PhIP by tea polyphenols is likely to be involved in the mechanism of chemoprotection of tea against this carcinogen

  6. Homogeneous plate based antibody internalization assay using pH sensor fluorescent dye.

    Science.gov (United States)

    Nath, Nidhi; Godat, Becky; Zimprich, Chad; Dwight, Stephen J; Corona, Cesear; McDougall, Mark; Urh, Marjeta

    2016-04-01

    Receptor-mediated antibody internalization is a key mechanism underlying several anti-cancer antibody therapeutics. Delivering highly toxic drugs to cancer cells, as in the case of antibody drug conjugates (ADCs), efficient removal of surface receptors from cancer cells and changing the pharmacokinetics profile of the antibody drugs are some of key ways that internalization impacts the therapeutic efficacy of the antibodies. Over the years, several techniques have been used to study antibody internalization including radiolabels, fluorescent microscopy, flow cytometry and cellular toxicity assays. While these methods allow analysis of internalization, they have limitations including a multistep process and limited throughput and are generally endpoint assays.