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Sample records for concentrated hyperpolarized solution

  1. A magnetic tunnel to shelter hyperpolarized fluids

    Energy Technology Data Exchange (ETDEWEB)

    Milani, Jonas, E-mail: jonas.milani@epfl.ch; Vuichoud, Basile; Bornet, Aurélien; Miéville, Pascal; Mottier, Roger [Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Batochime, CH-1015 Lausanne (Switzerland); Jannin, Sami [Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Batochime, CH-1015 Lausanne (Switzerland); Bruker BioSpin AG, Industriestrasse 26, CH-8117 Fällanden (Switzerland); Bodenhausen, Geoffrey [Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), Batochime, CH-1015 Lausanne (Switzerland); Département de Chimie, École Normale Supérieure-PSL Research University, 24 rue Lhomond, F-75005 Paris (France); Sorbonne Universités, UPMC Univ Paris 06, LBM, 4 place Jussieu, F-75005 Paris (France); CNRS, UMR 7203 LBM, F-75005 Paris (France)

    2015-02-15

    To shield solutions carrying hyperpolarized nuclear magnetization from rapid relaxation during transfer through low fields, the transfer duct can be threaded through an array of permanent magnets. The advantages are illustrated for solutions containing hyperpolarized {sup 1}H and {sup 13}C nuclei in a variety of molecules.

  2. A magnetic tunnel to shelter hyperpolarized fluids

    International Nuclear Information System (INIS)

    Milani, Jonas; Vuichoud, Basile; Bornet, Aurélien; Miéville, Pascal; Mottier, Roger; Jannin, Sami; Bodenhausen, Geoffrey

    2015-01-01

    To shield solutions carrying hyperpolarized nuclear magnetization from rapid relaxation during transfer through low fields, the transfer duct can be threaded through an array of permanent magnets. The advantages are illustrated for solutions containing hyperpolarized 1 H and 13 C nuclei in a variety of molecules

  3. Pulmonary hyperpolarized (129) Xe morphometry for mapping xenon gas concentrations and alveolar oxygen partial pressure: Proof-of-concept demonstration in healthy and COPD subjects.

    Science.gov (United States)

    Ouriadov, A; Farag, A; Kirby, M; McCormack, D G; Parraga, G; Santyr, G E

    2015-12-01

    Diffusion-weighted (DW) hyperpolarized (129) Xe morphometry magnetic resonance imaging (MRI) can be used to map regional differences in lung tissue micro-structure. We aimed to generate absolute xenon concentration ([Xe]) and alveolar oxygen partial pressure (pA O2 ) maps by extracting the unrestricted diffusion coefficient (D0 ) of xenon as a morphometric parameter. In this proof-of-concept demonstration, morphometry was performed using multi b-value (0, 12, 20, 30 s/cm(2) ) DW hyperpolarized (129) Xe images obtained in four never-smokers and four COPD ex-smokers. Morphometric parameters and D0 maps were computed and the latter used to generate [Xe] and pA O2 maps. Xenon concentration phantoms estimating a range of values mimicking those observed in vivo were also investigated. Xenon D0 was significantly increased (P = 0.035) in COPD (0.14 ± 0.03 cm(2) /s) compared with never-smokers (0.12 ± 0.02 cm(2) /s). COPD ex-smokers also had significantly decreased [Xe] (COPD = 8 ± 7% versus never-smokers = 13 ± 8%, P = 0.012) and increased pA O2 (COPD = 18 ± 3% versus never-smokers = 15 ± 3%, P = 0.009) compared with never-smokers. Phantom measurements showed the expected dependence of D0 on [Xe] over the range of concentrations anticipated in vivo. DW hyperpolarized (129) Xe MRI morphometry can be used to simultaneously map [Xe] and pA O2 in addition to providing micro-structural biomarkers of emphysematous destruction in COPD. Phantom measurements of D0 ([Xe]) supported the hypotheses that differences in subjects may reflect differences in functional residual capacity. © 2014 Wiley Periodicals, Inc.

  4. Transportable hyperpolarized metabolites

    Science.gov (United States)

    Ji, Xiao; Bornet, Aurélien; Vuichoud, Basile; Milani, Jonas; Gajan, David; Rossini, Aaron J.; Emsley, Lyndon; Bodenhausen, Geoffrey; Jannin, Sami

    2017-01-01

    Nuclear spin hyperpolarization of 13C-labelled metabolites by dissolution dynamic nuclear polarization can enhance the NMR signals of metabolites by several orders of magnitude, which has enabled in vivo metabolic imaging by MRI. However, because of the short lifetime of the hyperpolarized magnetization (typically <1 min), the polarization process must be carried out close to the point of use. Here we introduce a concept that markedly extends hyperpolarization lifetimes and enables the transportation of hyperpolarized metabolites. The hyperpolarized sample can thus be removed from the polarizer and stored or transported for use at remote MRI or NMR sites. We show that hyperpolarization in alanine and glycine survives 16 h storage and transport, maintaining overall polarization enhancements of up to three orders of magnitude. PMID:28072398

  5. Probing cardiac metabolism by hyperpolarized 13C MR using an exclusively endogenous substrate mixture and photo-induced nonpersistent radicals

    DEFF Research Database (Denmark)

    Bastiaansen, Jessica A M; Yoshihara, Hikari A I; Capozzi, Andrea

    2018-01-01

    dissolved, and the radical-free hyperpolarized solution was rapidly transferred into an injection pump located inside a 9.4T scanner. The hyperpolarized solution was injected in healthy rats to measure cardiac metabolism in vivo. Ultraviolet irradiation created nonpersistent radicals in a mixture containing......To probe the cardiac metabolism of carbohydrates and short chain fatty acids simultaneously in vivo following the injection of a hyperpolarized 13 C-labeled substrate mixture prepared using photo-induced nonpersistent radicals. Droplets of mixed [1-13 C]pyruvic and [1-13 C]butyric acids were frozen...... into glassy beads in liquid nitrogen. Ethanol addition was investigated as a means to increase the polarization level. The beads were irradiated with ultraviolet light and the radical concentration was measured by ESR spectroscopy. Following dynamic nuclear polarization in a 7T polarizer, the beads were...

  6. Hyperpolarized NMR Probes for Biological Assays

    Directory of Open Access Journals (Sweden)

    Sebastian Meier

    2014-01-01

    Full Text Available During the last decade, the development of nuclear spin polarization enhanced (hyperpolarized molecular probes has opened up new opportunities for studying the inner workings of living cells in real time. The hyperpolarized probes are produced ex situ, introduced into biological systems and detected with high sensitivity and contrast against background signals using high resolution NMR spectroscopy. A variety of natural, derivatized and designed hyperpolarized probes has emerged for diverse biological studies including assays of intracellular reaction progression, pathway kinetics, probe uptake and export, pH, redox state, reactive oxygen species, ion concentrations, drug efficacy or oncogenic signaling. These probes are readily used directly under natural conditions in biofluids and are often directly developed and optimized for cellular assays, thus leaving little doubt about their specificity and utility under biologically relevant conditions. Hyperpolarized molecular probes for biological NMR spectroscopy enable the unbiased detection of complex processes by virtue of the high spectral resolution, structural specificity and quantifiability of NMR signals. Here, we provide a survey of strategies used for the selection, design and use of hyperpolarized NMR probes in biological assays, and describe current limitations and developments.

  7. Hyperpolarized Nanodiamond Surfaces.

    Science.gov (United States)

    Rej, Ewa; Gaebel, Torsten; Waddington, David E J; Reilly, David J

    2017-01-11

    The widespread use of nanodiamond as a biomedical platform for drug-delivery, imaging, and subcellular tracking applications stems from its nontoxicity and unique quantum mechanical properties. Here, we extend this functionality to the domain of magnetic resonance, by demonstrating that the intrinsic electron spins on the nanodiamond surface can be used to hyperpolarize adsorbed liquid compounds at low fields and room temperature. By combining relaxation measurements with hyperpolarization, spins on the surface of the nanodiamond can be distinguished from those in the bulk liquid. These results are likely of use in signaling the controlled release of pharmaceutical payloads.

  8. USE CELLULOSE FOR CLEANING CONCENTRATED SUGAR SOLUTIONS

    Directory of Open Access Journals (Sweden)

    N. G. Kul’neva

    2015-01-01

    Full Text Available Summary. Producing high quality intermediate products in the boiling-crystallization station is an actual problem of sugar production. In the production of white sugar brown sugar syrup is not further purified that decreases the quality of the end product. Studies have been conducted using cellulose as an adsorbent for the purification of concentrated sugar solutions, having affinity to dyes and other impurities. Research have been carried out with the intermediate products of the Lebedyan sugar plant. Test results have shown cellulose ability to adsorb the dyes in sugar production. The influence of the adsorbent concentration and the mass fraction of solids in the syrup on the decolorization effect has been studied; rational process parameters have been obtained. It has been found that proceeding an additional adsorption purification of brown sugars syrup allows to reduce the solution color, increase the amount and quality of the end product. Adsorbing means, received from production wastes on the basis of organic resources, have many advantages: economical, environmentally friendly for disposal, safe to use, reliable and efficient in use. Conducted research on using cellulose as adsorbent for treatment of concentrated sugar solutions, having an affinity for colouring matter and other impurities. The experiments were carried out on the intermediates Lebedyanskiy sugar factory. The test results showed the ability of cellulose to adsorb coloring matter of sugar production. To evaluate the effect of bleaching depending on the mass fraction of dry substances prepared yellow juice filtration of sugar concentration of 55, 60, 65 % with subsequent adsorption purification of cellulose. The results of the experiment built adsorption isotherm of dyestuffs. The influence of the concentration of the adsorbent and a mass fraction of solids of juice filtration on the efficiency of decolorization obtained by rational parameters of the process. It is

  9. Analysis of Cancer Metabolism by Imaging Hyperpolarized Nuclei: Prospects for Translation to Clinical Research

    Directory of Open Access Journals (Sweden)

    John Kurhanewicz

    2011-02-01

    Full Text Available A major challenge in cancer biology is to monitor and understand cancer metabolism in vivo with the goal of improved diagnosis and perhaps therapy. Because of the complexity of biochemical pathways, tracer methods are required for detecting specific enzyme-catalyzed reactions. Stable isotopes such as 13C or 15N with detection by nuclear magnetic resonance provide the necessary information about tissue biochemistry, but the crucial metabolites are present in low concentration and therefore are beyond the detection threshold of traditional magnetic resonance methods. A solution is to improve sensitivity by a factor of 10,000 or more by temporarily redistributing the populations of nuclear spins in a magnetic field, a process termed hyperpolarization. Although this effect is short-lived, hyperpolarized molecules can be generated in an aqueous solution and infused in vivo where metabolism generates products that can be imaged. This discovery lifts the primary constraint on magnetic resonance imaging for monitoring metabolism—poor sensitivity—while preserving the advantage of biochemical information. The purpose of this report was to briefly summarize the known abnormalities in cancer metabolism, the value and limitations of current imaging methods for metabolism, and the principles of hyperpolarization. Recent preclinical applications are described. Hyperpolarization technology is still in its infancy, and current polarizer equipment and methods are suboptimal. Nevertheless, there are no fundamental barriers to rapid translation of this exciting technology to clinical research and perhaps clinical care.

  10. Radiolysis of concentrated nitric acid solutions

    International Nuclear Information System (INIS)

    Nagaishi, R.; Jiang, P.Y.; Katsumura, Y.; Domae, M.; Ishigure, K.

    1995-01-01

    A study on electron pulse- and 60 Co γ-radiolysis of concentrated nitric acid and nitrate solutions has been carried out to elucidate the radiation induced reactions taking place in the solutions. Dissociation into NO 2 - and O( 3 P) was proposed as a direct action of the radiation on nitrate and gave the G-values were dependent on the chemical forms of nitrate: g s2 (-NO 3 - )=1.6 and g s2 (-HNO 3 )=2.2 (molecules/100eV). Based on the experimental yields of HNO 2 and reduced Ce IV , the primary yields of radiolysis products of water, g w , were evaluated to clarify the effects of nitrate on spur reactions of water in various nitrate solutions. (author)

  11. Structural study of concentrated micellar solutions

    International Nuclear Information System (INIS)

    Zemb, Thomas

    1985-01-01

    This research thesis reports the study of the structure of concentrated soap-water binary micelles with a comparison of measurements of light, neutrons and X-ray scattering, and the relaxation induced by paramagnetic ions adsorbed at the interface. In the first part, the author discusses the specific sensitivity ranges of different experimental techniques, outlines the resolution which can be obtained with scattering experiments, and proposes a critical analysis of results published in the relevant literature. In a second part, the author discusses the compared results of the application of various techniques (magnetic resonance, X-light and neutron scattering) on the two most used model systems: sodium octanoate and sodium dodecyl sulfate (SDS) in solution. Then, the author addresses the case of ternary systems: study of the influence of the presence of a co-surfactant on the structure, study of the effect of interfacial charge on the micellar structure, use of the same previous quantitative methods to study the disturbances brought to the structure due to the presence of reactants [fr

  12. Field dependence of T1 for hyperpolarized [1-13C]pyruvate

    DEFF Research Database (Denmark)

    Chattergoon, N.; Martnez-Santiesteban, F.; Handler, W. B.

    2013-01-01

    conformation and properties of the dissolution media such as buffer composition, solution pH, temperature and magnetic field. We have measured the magnetic field dependence of the spin–lattice relaxation time of hyperpolarized [1-13C]pyruvate using field-cycled relaxometry. [1-13C]pyruvate was hyperpolarized...

  13. Properties of concentrated plutonium nitrate solutions

    International Nuclear Information System (INIS)

    Gray, J.H.; Swanson, J.L.

    1978-01-01

    Selected properties were measured for solutions containing about 500 and 700 g/l plutonium (IV) in 4--5M nitric acid: density, viscosity, vapor pressure, boiling point, radiolytic gas (H 2 ) evolution rates, and corrosion rate on Ti and 304L stainless steel. Pu solubility was determined to be 550 to 800 g/l in 2.5 to 7M HNO 3 at ambient temperature and 820 to 860 g/l in 3M HNO 3 at 50 0 C

  14. Nitrate concentrations in soil solutions below Danish forests

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Raulund-Rasmussen, Karsten; Gundersen, Per

    1999-01-01

    leaching in relation to land-use, a national monitoring programme has established sampling routines in a 7x7 km grid including 111 points in forests. During winters of 1986-1993, soil samples were obtained from a depth of 0-25, 25-50, 50-75 and 75-100 cm. Nitrate concentrations in soil solutions were...... species. A few sites deviated radically from the general pattern of low concentrations. The elevated concentrations recorded there were probably caused by high levels of N deposition due to emission from local sources or temporal disruptions of the N cycle. The nitrate concentration in the soil solution...

  15. Stability and Concentration Verification of Ammonium Perchlorate Dosing Solutions

    National Research Council Canada - National Science Library

    Tsui, David

    1998-01-01

    Stability and concentration verification was performed for the ammonium perchlorate dosing solutions used in the on-going 90-Day Oral Toxicity Study conducted by Springborn Laboratories, Inc. (SLI Study No. 3433.1...

  16. Microrheology of concentrated DNA solutions using optical tweezers

    Indian Academy of Sciences (India)

    . In this work, we report the determination of microrheological properties of concentrated, double-stranded calf thymus DNA (CT-DNA) solutions using passive, laser-scattering based particle-tracking methodology. From power spectral analysis, ...

  17. Ionic channels and membrane hyperpolarization in human macrophages

    NARCIS (Netherlands)

    Ince, C.; van Duijn, B.; Ypey, D. L.; van Bavel, E.; Weidema, F.; Leijh, P. C.

    1987-01-01

    Microelectrode impalement of human macrophages evokes a transient hyperpolarizing response (HR) of the membrane potential. This HR was found to be dependent on the extracellular concentration of K+ but not on that of Na+ or Cl-. It was not influenced by low temperature (12 degrees C) or by 0.2 mM

  18. A portable concentrator for processing plutonium containing solutions

    International Nuclear Information System (INIS)

    Chamberlain, D.B.; Conner, C.; Chen, L.

    1995-01-01

    This report describes a horizontal, compact agitated-film concentrator called a Rototherm, manufactured by Artisan Industries, Inc. which can be used to process aqueous solutions of radioactive wastes containing plutonium. The unit is designed to concentrate liquid streams to a high-solid content slurry

  19. Hyperpolarized 129Xe as an NMR probe for functional studies

    International Nuclear Information System (INIS)

    Wolber, J.

    2000-01-01

    The nuclear spin polarization of 129 Xe can be enhanced by several orders of magnitude using optical pumping techniques, resulting in a dramatic enhancement of the 129 Xe Nuclear Magnetic Resonance (NMR) signal. The 'hyperpolarized' gas can be used for Magnetic Resonance Imaging (MRI) of the void spaces of the lungs after introduction of the gas into the respiratory system. Furthermore, the high solubility of xenon in blood and lipids suggests the use of 129 Xe NMR for studying blood flow, permeability, perfusion and blood volume. Hyperpolarized 129 Xe MRI has the potential of combining the high sensitivity and functional information of radioactive tracer studies with the high spatial and temporal resolution of MRI. The spin-lattice relaxation time T 1 of 129 Xe in blood determines the loss of polarization during transit from the lungs to the tissue of interest. A difference in the relaxation times of xenon in oxygenated and deoxygenated blood could be used as a contrast mechanism in functional Magnetic Resonance Imaging (fMRI). In this thesis, the hyperpolarized 129 Xe T 1 in human blood is measured in vitro as a function of blood oxygenation, and the relevant relaxation mechanisms are discussed. A new and unexpected finding is that the hyperpolarized 129 Xe NMR spectrum in blood is highly sensitive to blood oxygenation. Therefore, hyperpolarized 129 Xe NMR provides a powerful means of measuring blood oxygenation quantitatively and non-invasively. The interaction of xenon with hemoglobin is responsible for an oxygen-dependent shift of the 129 Xe NMR resonance of xenon in red blood cells. Injection delivery of hyperpolarized 129 Xe in solution could be a more efficient method of administrating the gas for functional NMR studies. For this purpose, suitable biocompatible carrier media have been studied. In particular, the use of perfluorocarbon emulsions, which are already in use as blood substitutes, as delivery media for hyperpolarized 129 Xe has been investigates

  20. Salt type and concentration affect the viscoelasticity of polyelectrolyte solutions

    Science.gov (United States)

    Turkoz, Emre; Perazzo, Antonio; Arnold, Craig B.; Stone, Howard A.

    2018-05-01

    The addition of small amounts of xanthan gum to water yields viscoelastic solutions. In this letter, we show that the viscoelasticity of aqueous xanthan gum solutions can be tuned by different types of salts. In particular, we find that the decrease in viscoelasticity not only depends, as is known, on the salt concentration, but also is affected by the counterion ionic radius and the valence of the salt.

  1. Conductivity and electrochemical stability of concentrated aqueous choline chloride solutions

    Science.gov (United States)

    Grishina, E. P.; Kudryakova, N. O.

    2017-10-01

    The conductivity and electrochemical stability of choline chloride (ChCl) solutions with water contents ranging from 20 to 39 wt % are studied. Exposing ChCl to moist ambient air yields a highly concentrated aqueous solution that, as an electrolyte, exhibits the properties and variations in conductivity with temperature and concentration characteristic of other similar systems. Its electrochemical stability window, determined by cyclic voltammetry, is comparable to that of ChCl-based deep eutectic solvents (DESs). Products of the electrolysis of ChCl‒H2O mixtures seem to be less toxic than those of Reline, Ethaline, and Maline.

  2. Molecular MRI based on hyper-polarized xenon

    International Nuclear Information System (INIS)

    Tassali, Nawal

    2012-01-01

    Magnetic Resonance Imaging (MRI) has a high importance in medicine as it enables the observation of the organs inside the body without the use of radiative or invasive techniques. However it is known to suffer from poor sensitivity. To circumvent this limitation, a key solution resides in the use of hyper-polarized species. Among the entities with which we can drastically increase nuclear polarization, xenon has very specific properties through its interactions with its close environment that lead to a wide chemical shift bandwidth. The goal is thus to use it as a tracer. This PhD thesis focuses on the concept of 129 Xe MRI-based sensors for the detection of biological events. In this approach, hyper-polarized xenon is vectorized to biological targets via functionalized host systems, and then localized thanks to fast dedicated MRI sequences. The conception and set-up of a spin-exchange optical pumping device is first described. Then studies about the interaction of the hyper-polarized noble gas with new cryptophanes susceptible to constitute powerful host molecules are detailed. Also the implementation of recent MRI sequences optimized for the transient character of the hyper-polarization and taking profit of the xenon in-out exchange is described. Applications of this approach for the detection of metallic ions and cellular receptors are studied. Finally, our first in vivo results on a small animal model are presented. (author) [fr

  3. Development of system on predicting uranium concentration from pregnant solution

    International Nuclear Information System (INIS)

    Yi Weiping

    2004-01-01

    Uranium concentration from pregnant solution is primary index of process for in-situ leaching of uranium, and the suitable method with which to predicate this index and effective means to solve it with were continuously studied hard. SPUC-system on predicting uranium concentration based on GM model of gray system theory is developed, and the mathematical model, constitution, function and theory foundation of this system are introduced. (authors)

  4. Impact of solute concentration on the electrocatalytic conversion of dissolved gases in buffered solutions

    KAUST Repository

    Shinagawa, Tatsuya; Takanabe, Kazuhiro

    2015-01-01

    . These alterations of the electrolyte properties associated with the solute concentration are universally applicable to other aqueous gas-related electrochemical reactions because the currents are purely determined by mass transfer of the dissolved gases. © 2015

  5. Densities concentrations of aqueous of uranyl nitrate solutions

    International Nuclear Information System (INIS)

    Rodrigo Otero, A.; Rodriguez Hernandez, B.; Fernandez Rodriguez, L.

    1966-01-01

    The ratio density-concentration of aqueous uranyl nitrate solutions expressed as U 3 O 8 grams/liter, U grams/liter and hexahydrate uranyl nitrate weight percent at different temperatures, are established. Experimental values are graphically correlated and compared whit some published data. (Author) 2 refs

  6. Rheological properties of concentrated solutions of carboxymethyl starch

    Directory of Open Access Journals (Sweden)

    Stojanović Željko

    2003-01-01

    Full Text Available Carboxymethyl starch was synthesized by the esterification of starch with monochloroacetic acid in ethanol as a reaction medium. Three samples of carboxymethyl starch having different degrees of substitution were prepared. The influence of temperature on the viscosity of concentrated carboxymethyl starch solutions, as well as the dynamic-mechanical properties of the concentrated solutions were investigated. The activation energy of viscous flow was determined and it was found that it decreased with increasing degree of substitution. The results of the dynamic-mechanical measurements showed that solutions of starch and carboxymethyl starches with higher degrees of substitution behave as gels. Values of the storage modulus in the rubbery plateau were used to calculate the molar masses between two points of physical crosslinking, the density of crosslinking and the distance between two points of crosslinking.

  7. Acquisition and Analysis of Data from High Concentration Solutions

    KAUST Repository

    Besong, Tabot M.D.

    2016-05-13

    The problems associated with ultracentrifugal analysis of macromolecular solutions at high (>10 mg/ml) are reviewed. Especially for the case of solutes which are non-monodisperse, meaningful results are not readily achievable using sedimentation velocity approaches. It is shown however by both simulation and analysis of practical data that using a modified form of an algorithm (INVEQ) published in other contexts, sedimentation equilibrium (SE) profiles can be analysed successfully, enabling topics such as oligomer presence or formation to be defined.To achieve this, it is necessary to employ an approach in which the solution density, which in an SE profile is radius-dependent, is taken into consideration. Simulation suggests that any reasonable level of solute concentration can be analysed.

  8. Acquisition and Analysis of Data from High Concentration Solutions

    KAUST Repository

    Besong, Tabot M.D.; Rowe, Arthur J.

    2016-01-01

    The problems associated with ultracentrifugal analysis of macromolecular solutions at high (>10 mg/ml) are reviewed. Especially for the case of solutes which are non-monodisperse, meaningful results are not readily achievable using sedimentation velocity approaches. It is shown however by both simulation and analysis of practical data that using a modified form of an algorithm (INVEQ) published in other contexts, sedimentation equilibrium (SE) profiles can be analysed successfully, enabling topics such as oligomer presence or formation to be defined.To achieve this, it is necessary to employ an approach in which the solution density, which in an SE profile is radius-dependent, is taken into consideration. Simulation suggests that any reasonable level of solute concentration can be analysed.

  9. T1 nuclear magnetic relaxation dispersion of hyperpolarized sodium and cesium hydrogencarbonate-13 C.

    Science.gov (United States)

    Martínez-Santiesteban, Francisco M; Dang, Thien Phuoc; Lim, Heeseung; Chen, Albert P; Scholl, Timothy J

    2017-09-01

    In vivo pH mapping in tissue using hyperpolarized hydrogencarbonate- 13 C has been proposed as a method to study tumor growth and treatment and other pathological conditions related to pH changes. The finite spin-lattice relaxation times (T 1 ) of hyperpolarized media are a significant limiting factor for in vivo imaging. Relaxation times can be measured at standard magnetic fields (1.5 T, 3.0 T etc.), but no such data are available at low fields, where T 1 values can be significantly shorter. This information is required to determine the potential loss of polarization as the agent is dispensed and transported from the polarizer to the MRI scanner. The purpose of this study is to measure T 1 dispersion from low to clinical magnetic fields (0.4 mT to 3.0 T) of different hyperpolarized hydrogencarbonate formulations previously proposed in the literature for in vivo pH measurements. 13 C-enriched cesium and sodium hydrogencarbonate preparations were hyperpolarized using dynamic nuclear polarization, and the T 1 values of different samples were measured at different magnetic field strengths using a fast field-cycling relaxometer and a 3.0 T clinical MRI system. The effects of deuterium oxide as a dissolution medium for sodium hydrogencarbonate were also analyzed. This study finds that the cesium formulation has slightly shorter T 1 values compared with the sodium preparation. However, the higher solubility of cesium hydrogencarbonate- 13 C means it can be polarized at greater concentration, using less trityl radical than sodium hydrogencarbonate- 13 C. This study also establishes that the preparation and handling of sodium hydrogencarbonate formulations in relation to cesium hydrogencarbonate is more difficult, due to the higher viscosity and lower achievable concentrations, and that deuterium oxide significantly increases the T 1 of sodium hydrogencarbonate solutions. Finally, this work also investigates the influence of pH on the spin-lattice relaxation of cesium

  10. Concentration Fluctuations and Capacitive Response in Dense Ionic Solutions.

    Science.gov (United States)

    Uralcan, Betul; Aksay, Ilhan A; Debenedetti, Pablo G; Limmer, David T

    2016-07-07

    We use molecular dynamics simulations in a constant potential ensemble to study the effects of solution composition on the electrochemical response of a double layer capacitor. We find that the capacitance first increases with ion concentration following its expected ideal solution behavior but decreases upon approaching a pure ionic liquid in agreement with recent experimental observations. The nonmonotonic behavior of the capacitance as a function of ion concentration results from the competition between the independent motion of solvated ions in the dilute regime and solvation fluctuations in the concentrated regime. Mirroring the capacitance, we find that the characteristic decay length of charge density correlations away from the electrode is also nonmonotonic. The correlation length first decreases with ion concentration as a result of better electrostatic screening but increases with ion concentration as a result of enhanced steric interactions. When charge fluctuations induced by correlated ion-solvent fluctuations are large relative to those induced by the pure ionic liquid, such capacitive behavior is expected to be generic.

  11. Fissile materials in solution concentration measured by active neutron interrogation

    International Nuclear Information System (INIS)

    Romeyer Dherbey, J.; Passard, Ch.; Cloue, J.; Bignan, G.

    1993-01-01

    The use of the active neutron interrogation to measure the concentration of plutonium contained in flow solutions is particularly interesting for fuel reprocessing plants. Indeed, this method gives a signal which is in a direct relation with the fissile materials concentration. Moreover, it is less sensitive to the gamma dose rate than the other nondestructive methods. Two measure methods have been evolved in CEA. Their principles are given into details in this work. The first one consists to detect fission delayed neutrons induced by a 252 Cf source. In the second one fission prompt neutrons induced by a neutron generator of 14 MeV are detected. (O.M.)

  12. Small angle X-ray scattering on concentrated hemoglobin solutions

    International Nuclear Information System (INIS)

    Zinke, M.; Damaschun, G.; Mueller, J.J.; Ruckpaul, K.

    1978-01-01

    The small-angle X-ray scattering technique was used to determine the intermolecular structure and interaction potentials in oxi-and deoxi-hemoglobin solutions. The pair correlation function obtained by the ZERNICKE-PRINS equation characterizes the intermolecular structure of the hemoglobin molecules. The intermolecular structure is concentration dependent. The hemoglobin molecules have a 'short range order structure' with a range of about 4 molecule diameters at 324 g/l. The potential functions of the hemoglobin-hemoglobin interaction have been determined on the basis of fluid theories. Except for the deoxi-hemoglobin solution having the concentration 370 g/l, the pair interaction consists in a short repulsion and a weak short-range attraction against kT. The potential minimum is between 1.2 - 1.5 nm above the greatest hemoglobin diameter. (author)

  13. Osmotic potential calculations of inorganic and organic aqueous solutions over wide solute concentration levels and temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Cochrane, T. T., E-mail: agteca@hotmail.com [AGTECA S.A., 230 Oceanbeach Road, Mount Maunganui, Tauranga 3116 (New Zealand); Cochrane, T. A., E-mail: tom.cochrane@canterbury.ac.nz [Department of Civil and Natural Resources Engineering, University of Canterbury, Private Bag 4800, Christchurch 8140 (New Zealand)

    2016-01-15

    Purpose: To demonstrate that the authors’ new “aqueous solution vs pure water” equation to calculate osmotic potential may be used to calculate the osmotic potentials of inorganic and organic aqueous solutions over wide ranges of solute concentrations and temperatures. Currently, the osmotic potentials of solutions used for medical purposes are calculated from equations based on the thermodynamics of the gas laws which are only accurate at low temperature and solute concentration levels. Some solutions used in medicine may need their osmotic potentials calculated more accurately to take into account solute concentrations and temperatures. Methods: The authors experimented with their new equation for calculating the osmotic potentials of inorganic and organic aqueous solutions up to and beyond body temperatures by adjusting three of its factors; (a) the volume property of pure water, (b) the number of “free” water molecules per unit volume of solution, “N{sub f},” and (c) the “t” factor expressing the cooperative structural relaxation time of pure water at given temperatures. Adequate information on the volume property of pure water at different temperatures is available in the literature. However, as little information on the relative densities of inorganic and organic solutions, respectively, at varying temperatures needed to calculate N{sub f} was available, provisional equations were formulated to approximate values. Those values together with tentative t values for different temperatures chosen from values calculated by different workers were substituted into the authors’ equation to demonstrate how osmotic potentials could be estimated over temperatures up to and beyond bodily temperatures. Results: The provisional equations formulated to calculate N{sub f}, the number of free water molecules per unit volume of inorganic and organic solute solutions, respectively, over wide concentration ranges compared well with the calculations of N{sub f

  14. Osmotic potential calculations of inorganic and organic aqueous solutions over wide solute concentration levels and temperatures

    International Nuclear Information System (INIS)

    Cochrane, T. T.; Cochrane, T. A.

    2016-01-01

    Purpose: To demonstrate that the authors’ new “aqueous solution vs pure water” equation to calculate osmotic potential may be used to calculate the osmotic potentials of inorganic and organic aqueous solutions over wide ranges of solute concentrations and temperatures. Currently, the osmotic potentials of solutions used for medical purposes are calculated from equations based on the thermodynamics of the gas laws which are only accurate at low temperature and solute concentration levels. Some solutions used in medicine may need their osmotic potentials calculated more accurately to take into account solute concentrations and temperatures. Methods: The authors experimented with their new equation for calculating the osmotic potentials of inorganic and organic aqueous solutions up to and beyond body temperatures by adjusting three of its factors; (a) the volume property of pure water, (b) the number of “free” water molecules per unit volume of solution, “N f ,” and (c) the “t” factor expressing the cooperative structural relaxation time of pure water at given temperatures. Adequate information on the volume property of pure water at different temperatures is available in the literature. However, as little information on the relative densities of inorganic and organic solutions, respectively, at varying temperatures needed to calculate N f was available, provisional equations were formulated to approximate values. Those values together with tentative t values for different temperatures chosen from values calculated by different workers were substituted into the authors’ equation to demonstrate how osmotic potentials could be estimated over temperatures up to and beyond bodily temperatures. Results: The provisional equations formulated to calculate N f , the number of free water molecules per unit volume of inorganic and organic solute solutions, respectively, over wide concentration ranges compared well with the calculations of N f using recorded

  15. Impact of solute concentration on the electrocatalytic conversion of dissolved gases in buffered solutions

    KAUST Repository

    Shinagawa, Tatsuya

    2015-04-24

    To maintain local pH levels near the electrode during electrochemical reactions, the use of buffer solutions is effective. Nevertheless, the critical effects of the buffer concentration on electrocatalytic performances have not been discussed in detail. In this study, two fundamental electrochemical reactions, oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR), on a platinum rotating disk electrode are chosen as model gas-related aqueous electrochemical reactions at various phosphate concentrations. Our detailed investigations revealed that the kinetic and limiting diffusion current densities for both the ORR and HOR logarithmically decrease with increasing solute concentration (log|jORR|=-0.39c+0.92,log|jHOR|=-0.35c+0.73). To clarify the physical aspects of this phenomenon, the electrolyte characteristics are addressed: with increasing phosphate concentration, the gas solubility decrease, the kinematic viscosity of the solution increase and the diffusion coefficient of the dissolved gases decrease. The simulated limiting diffusion currents using the aforementioned parameters match the measured ones very well (log|jORR|=-0.43c+0.99,log|jHOR|=-0.40c+0.54), accurately describing the consequences of the electrolyte concentration. These alterations of the electrolyte properties associated with the solute concentration are universally applicable to other aqueous gas-related electrochemical reactions because the currents are purely determined by mass transfer of the dissolved gases. © 2015 The Authors.

  16. Automated assay of uranium solution concentration and enrichment

    International Nuclear Information System (INIS)

    Horley, E.C.; Gainer, K.; Hansen, W.J.; Kelley, T.A.; Parker, J.L.; Sampson, T.E.; Walton, G.; Jones, S.A.

    1992-01-01

    For the first time, the concentration and enrichment of uranium solutions can be measured in one step. We have developed a new instrument to automatically measure the concentration and enrichment of uranium solutions through the adaptation of a commercial robot. Two identical solution enrichment systems are being installed in the Portsmouth Gaseous Diffusion Plant. These automated systems will reduce radiation exposure to personnel and increase the reliability and repeatability of the measurements. Each robotic system can process up to 40 batch and 8 priority samples in an unattended mode. Both passive gamma-ray and x-ray fluorescence (XRF) analyses are performed to determine total uranium concentration and 235 U enrichment. Coded samples are read by a bar-code reader to determine measurement requirements, then assayed by either or both of the gamma-ray and XRF instruments. The robot moves the sample containers and operates all shield doors and shutters, reducing hardware complexity. If the robots is out of service, an operator can manually perform all operations

  17. Methylparaben concentration in commercial Brazilian local anesthetics solutions

    Directory of Open Access Journals (Sweden)

    Gustavo Henrique Rodriguez da Silva

    2012-08-01

    Full Text Available OBJECTIVE: To detect the presence and concentration of methylparaben in cartridges of commercial Brazilian local anesthetics. MATERIAL AND METHODS: Twelve commercial brands (4 in glass and 8 in plastic cartridges of local anesthetic solutions for use in dentistry were purchased from the Brazilian market and analyzed. Different lots of the commercial brands were obtained in different Brazilian cities (Piracicaba, Campinas and São Paulo. Separation was performed using high performance liquid chromatography (HPLC with UV-Vis detector. The mobile phase used was acetonitrile:water (75:25 - v/v, pH 4.5, adjusted with acetic acid at a flow rate of 1.0 ml.min-1. RESULTS: When detected in the solutions, the methylparaben concentration ranged from 0.01% (m/v to 0.16% (m/v. One glass and all plastic cartridges presented methylparaben. CONCLUSION: 1. Methylparaben concentration varied among solutions from different manufacturers, and it was not indicated in the drug package inserts; 2. Since the presence of methylparaben in dental anesthetics is not regulated by the Brazilian National Health Surveillance Agency (ANVISA and this substance could cause allergic reactions, it is important to alert dentists about its possible presence.

  18. Opalescence in monoclonal antibody solutions and its correlation with intermolecular interactions in dilute and concentrated solutions.

    Science.gov (United States)

    Raut, Ashlesha S; Kalonia, Devendra S

    2015-04-01

    Opalescence indicates physical instability of a formulation because of the presence of aggregates or liquid-liquid phase separation in solution and has been reported for monoclonal antibody (mAb) formulations. Increased solution opalescence can be attributed to attractive protein-protein interactions (PPIs). Techniques including light scattering, AUC, or membrane osmometry are routinely employed to measure PPIs in dilute solutions, whereas opalescence is seen at relatively higher concentrations, where both long- and short-range forces contribute to overall PPIs. The mAb molecule studied here shows a unique property of high opalescence because of liquid-liquid phase separation. In this study, opalescence measurements are correlated to PPIs measured in diluted and concentrated solutions using light scattering (kD ) and high-frequency rheology (G'), respectively. Charges on the molecules were calculated using zeta potential measurements. Results indicate that high opalescence and phase separation are a result of the attractive interactions in solution; however, the presence of attractive interactions do not always imply phase separation. Temperature dependence of opalescence suggests that thermodynamic contribution to opalescence is significant and Tcloud can be utilized as a potential tool to assess attractive interactions in solution. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  19. Effect of solution concentration on MEH-PPV thin films

    Science.gov (United States)

    Affendi, I. H. H.; Sarah, M. S. P.; Alrokayan, Salman A. H.; Khan, Haseeb A.; Rusop, M.

    2018-05-01

    MEH-PPV thin films were prepared with a mixture of THF (tetrahydrofuran) solution deposited by spin coating method. The surface topology of MEH-PPV thin film were characterize by atomic force microscopy (AFM) and optical properties of absorption spectra were characterized by using Ultraviolet-visible-near-infrared (UV-Vis-NIR). The MEH-PPV concentration variation affects the surface and optical properties of the thin film where 0.5 mg/ml MEH-PPV concentration have a good surface topology provided the same film also gives the highest absorption coefficient were then deposited to a TiO2 thin film forming composite layer. The composite layer then shows low current flow of short circuit current of Isc = -5.313E-7 A.

  20. Glacier Melting Increases the Solute Concentrations of Himalayan Glacial Lakes.

    Science.gov (United States)

    Salerno, Franco; Rogora, Michela; Balestrini, Raffaella; Lami, Andrea; Tartari, Gabriele A; Thakuri, Sudeep; Godone, Danilo; Freppaz, Michele; Tartari, Gianni

    2016-09-06

    Over the past two decades, we observed a substantial rise in ionic content that was mainly determined by the sulfate concentration at 20 remote high elevation lakes located in central southern Himalaya. At LCN9, which was monitored on an annual basis for the last 20 years, the sulfate concentrations increased over 4-fold. Among the main causes, we exclude a change in the composition of wet atmospheric deposition, as well as a possible influence of decrease in seasonal snow cover duration, which could have exposed larger basin surfaces to alteration processes. Glacier retreat likely was the main factor responsible for the observed increase of sulfate concentrations. We attribute this chemical changes mainly to the sulfide oxidation processes that occur in subglacial environments. Moreover, we observe that the weakened monsoon of the past two decades has only partially contributed to the lakes enrichment through runoff waters that are more concentrated in solutes or lowering the water table, resulting in more rock exposed to air and enhanced mineral oxidation.

  1. Intelligent fiber optic sensor for solution concentration examination

    Science.gov (United States)

    Borecki, Michal; Kruszewski, Jerzy

    2003-09-01

    This paper presents the working principles of intelligent fiber-optic intensity sensor used for solution concentration examination. The sensor head is the ending of the large core polymer optical fiber. The head works on the reflection intensity basis. The reflected signal level depends on Fresnel reflection and reflection on suspended matter when the head is submersed in solution. The sensor head is mounted on a lift. For detection purposes the signal includes head submerging, submersion, emerging and emergence is measured. This way the viscosity turbidity and refraction coefficient has an effect on measured signal. The signal forthcoming from head is processed electrically in opto-electronic interface. Then it is feed to neural network. The novelty of presented sensor is implementation of neural network that works in generalization mode. The sensor resolution depends on opto-electronic signal conversion precision and neural network learning accuracy. Therefore, the number and quality of points used for learning process is very important. The example sensor application for examination of liquid soap concentration in water is presented in the paper.

  2. Ion-exchange concentration of inorganic anions from aqueous solution

    Directory of Open Access Journals (Sweden)

    L. P. Bondareva

    2016-01-01

    Full Text Available Monitoring of natural waters in the present time - consuming process, the accuracy of which is influenced by many factors: the composition of water, the presence of impurities and "interfering" components. The water sample preparation process includes the step of concentration and separation of ions determined. The most versatile, efficient, and frequently used method is the concentration of inorganic anions from aqueous solutions by ion exchanger, which can optimize the composition of water to the optimal for identification and quantitative determination of anions. The characteristics of sorption chloride, nitrate and sulfate ions of basic anion exchange resin AВ-17 and Purolite A430 were compared in the article. The constants of protolysis of ion exchangers both AB 17 and Purolite A430 are the same and equal 0.037 ± 0,002. The value of total capacity (POE Purolite A430 was 4.3 mmol/g, AB 17 – 3.4 mmol/g. The studied ion exchangers have the same type of ionic groups – quaternary ammonium, but their number and denotes differ. The number of quaternary ammonium groups is higher in Purolite A430, respectively the number of absorbed anions of these ion exchanger is higher. The values of dynamic exchange capacity (DOE of ion exchanger Purolite A430 is higher than these values of AB-17 and equal to 1.48 ± 0.03 mmol / dm3 for chloride ion, 1.50 ± 0.03 mmol / dm3 for nitrate ion, 1.62 ± 0.03 mmol / dm3 for sulfate ion. The values of the POE and DOE of anion-exchange resins Purolite A430 and AV-17 and the characteristics of the individual sorption of chloride, nitrate, sulfate ions showed an advantage of the Purolite for the concentrationing of anions. It is found that times of anions sorption from triple-anion solutions by Purolite A430 are significantly different for different anions, and these times are close for anion-exchanger AV-17. It proves the possibility of quantitative separation and concentration by anion-exchanger Purolite A430.

  3. Radiation crosslinking of methylcellulose and hydroxyethylcellulose in concentrated aqueous solutions

    International Nuclear Information System (INIS)

    Wach, Radoslaw A.; Mitomo, Hiroshi; Nagasawa, Naotsugu; Yoshii, Fumio

    2003-01-01

    The effects of ionizing radiation on aqueous solutions of cellulose ethers, methylcellulose (MC) and hydroxyethylcellulose (HEC) were investigated. The well-established knowledge states that cellulose and its derivatives belong to degrading type of polymers. However, in our study intermolecular crosslinking initiated by gamma rays or electron beam leaded to the formation of insoluble gel. This is an opposite effect of irradiation to the degradation. Paste-like form of the initial specimen, i.e. concentration 20-30%, when water plasticizes the bulk of polymer; and a high dose rate were favorable for hydrogel formation. Gel fraction up to 60% and 70% was obtained from solutions of HEC and MC, respectively. Produced hydrogels swell markedly in aqueous media by imbibing and holding the solvent. Radiation parameters of irradiation, such as yields of degradation and crosslinking and the gelation dose, were evaluated by sol-gel analysis on the basis of Charlesby-Rosiak equation. Despite of the crosslinked structure, obtained hydrogels can be included into the group of biodegradable materials. They undergo decomposition by the action of cellulase enzyme or microorganisms from compost

  4. A Wavefront Division Polarimeter for the Measurements of Solute Concentrations in Solutions

    Directory of Open Access Journals (Sweden)

    Sergio Calixto

    2017-12-01

    Full Text Available Polarimeters are useful instruments that measure concentrations of optically active substances in a given solution. The conventional polarimetric principle consists of measuring the rotation angle of linearly polarized light. Here, we present a novel polarimeter based on the study of interference patterns. A Mach–Zehnder interferometer with linearly polarized light at the input is used. One beam passes through the liquid sample and the other is a reference beam. As the linearly polarized sample beam propagates through the optically active solution the vibration plane of the electric field will rotate. As a result, the visibility of the interference pattern at the interferometer output will decrease. Fringe contrast will be maximum when both beams present a polarization perpendicular to the plane of incidence. However, minimum visibility is obtained when, after propagation through the sample the polarization of the sample beam is oriented parallel to the plane of incidence. By using different solute concentrations, a calibration plot is obtained showing the behavior of visibility.

  5. A discussion about maximum uranium concentration in digestion solution of U3O8 type uranium ore concentrate

    International Nuclear Information System (INIS)

    Xia Dechang; Liu Chao

    2012-01-01

    On the basis of discussing the influence of single factor on maximum uranium concentration in digestion solution,the influence degree of some factors such as U content, H 2 O content, mass ratio of P and U was compared and analyzed. The results indicate that the relationship between U content and maximum uranium concentration in digestion solution was direct ratio, while the U content increases by 1%, the maximum uranium concentration in digestion solution increases by 4.8%-5.7%. The relationship between H 2 O content and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 46.1-55.2 g/L while H 2 O content increases by 1%. The relationship between mass ratio of P and U and maximum uranium concentration in digestion solution was inverse ratio, the maximum uranium concentration in digestion solution decreases by 116.0-181.0 g/L while the mass ratio of P and U increase 0.1%. When U content equals 62.5% and the influence of mass ratio of P and U is no considered, the maximum uranium concentration in digestion solution equals 1 578 g/L; while mass ratio of P and U equals 0.35%, the maximum uranium concentration decreases to 716 g/L, the decreased rate is 54.6%, so the mass ratio of P and U in U 3 O 8 type uranium ore concentrate is the main controlling factor. (authors)

  6. Contribution of the ''simple solutions'' concept to estimate density of actinides concentrated solutions

    International Nuclear Information System (INIS)

    Sorel, C.; Moisy, Ph.; Dinh, B.; Blanc, P.

    2000-01-01

    In order to calculate criticality parameters of nuclear fuel solution systems, number density of nuclides are needed and they are generally estimated from density equations. Most of the relations allowing the calculation of the density of aqueous solutions containing the electrolytes HNO 3 -UO 2 (NO 3 ) 2 -Pu(NO 3 ) 4 , usually called 'nitrate dilution laws' are strictly empirical. They are obtained from a fit of assumed polynomial expressions on experimental density data. Out of their interpolation range, such mathematical expressions show discrepancies between calculated and experimental data appearing in the high concentrations range. In this study, a physico-chemical approach based on the isopiestic mixtures rule is suggested. The behaviour followed by these mixtures was first observed in 1936 by Zdanovskii and expressed as: 'Binary solutions (i.e. one electrolyte in water) having a same water activity are mixed without variation of this water activity value'. With regards to this behaviour, a set of basic thermodynamic expressions has been pointed out by Ryazanov and Vdovenko in 1965 concerning enthalpy, entropy, volume of mixtures, activity and osmotic coefficient of the components. In particular, a very simple relation for the density is obtained from the volume mixture expression depending on only two physico-chemical variables: i) concentration of each component in the mixture and in their respectively binary solutions having the same water activity as the mixture and ii), density of each component respectively in the binary solution having the same water activity as the mixture. Therefore, the calculation needs the knowledge of binary data (water activity, density and concentration) of each component at the same temperature as the mixture. Such experimental data are largely published in the literature and are available for nitric acid and uranyl nitrate. Nevertheless, nitric acid binary data show large discrepancies between the authors and need to be

  7. Concentration of rhenium from dilute sodium chloride solutions

    Directory of Open Access Journals (Sweden)

    DRAGOLJUB M. LUKIC

    2008-03-01

    Full Text Available The conditions for the desorption of rhenium from the anion exchange resin Dowex 1-x8 by HNO3, HCl, H2SO4 and NaOH were determined. The solution (5.0´10-3 mol dm-3 Re in 0.15 mol dm-3 NaCl was passed through a column containing 0.10 g of the resin. The total sorbed amount of rhenium was 0.20 g/g of the resin. It was then eluted by the corresponding eluent in the concentration range up to about 3.0 mol dm-3. The highest elution efficiency and the most favourable elution profile were found with 3.0 mol dm-3 HNO3. Over 77 % of the sorbed rhenium was found in the first 5 ml of the eluate. Practically all the rhenium was recovered with 20 ml of the acid. Under the given experimental conditions, HCl and H2SO4 were less favourable while NaOH was not applicable, due to very low efficiency of rhenium elution.

  8. Studies to enhance the hyperpolarization level in PHIP-SAH-produced C13-pyruvate

    Science.gov (United States)

    Cavallari, Eleonora; Carrera, Carla; Aime, Silvio; Reineri, Francesca

    2018-04-01

    The use of [1-13C]pyruvate, hyperpolarized by dissolution-Dynamic Nuclear Polarization (d-DNP), in in vivo metabolic studies has developed quickly, thanks to the imaging probe's diagnostic relevance. Nevertheless, the cost of a d-DNP polarizer is quite high and the speed of hyperpolarization process is relatively slow, meaning that its use is limited to few research laboratories. ParaHydrogen Induced Polarization Side Arm Hydrogenation (PHIP-SAH) (Reineri et al., 2015) is a cost effective and easy-to-handle method that produces 13C-MR hyperpolarization in [1-13C]pyruvate and other metabolites. This work aims to identify the main determinants of the hyperpolarization levels observed in C13-pyruvate using this method. By dissecting the various steps of the PHIP-SAH procedure, it has been possible to assess the role of several experimental parameters whose optimization must be pursued if this method is to be made suitable for future translational steps. The search for possible solutions has led to improvements in the polarization of sodium [1-13C]pyruvate from 2% to 5%. Moreover, these results suggest that observed polarization levels could be increased considerably by an automatized procedure which would reduce the time required for the work-up passages that are currently carried out manually. The results reported herein mean that the attainment of polarization levels suitable for the metabolic imaging applications of these hyperpolarized substrates show significant promise.

  9. Hyperpolarization moves S4 sensors inward to open MVP, a methanococcal voltage-gated potassium channel.

    Science.gov (United States)

    Sesti, Federico; Rajan, Sindhu; Gonzalez-Colaso, Rosana; Nikolaeva, Natalia; Goldstein, Steve A N

    2003-04-01

    MVP, a Methanococcus jannaschii voltage-gated potassium channel, was cloned and shown to operate in eukaryotic and prokaryotic cells. Like pacemaker channels, MVP opens on hyperpolarization using S4 voltage sensors like those in classical channels activated by depolarization. The MVP S4 span resembles classical sensors in sequence, charge, topology and movement, traveling inward on hyperpolarization and outward on depolarization (via canaliculi in the protein that bring the extracellular and internal solutions into proximity across a short barrier). Thus, MVP opens with sensors inward indicating a reversal of S4 position and pore state compared to classical channels. Homologous channels in mammals and plants are expected to function similarly.

  10. The influence of surface roughness and solution concentration on pool boiling process in Diethanolamine aqueous solution

    Science.gov (United States)

    Khoshechin, Mohsen; Salimi, Farhad; Jahangiri, Alireza

    2018-04-01

    In this research, the effect of surface roughness and concentration of solution on bubble departing frequency and nucleation site density for pool boiling of water/diethanolamine (DEA) binary solution were investigated experimentally. In this investigation, boiling heat transfer coefficient, bubble departing frequency and nucleation site density have been experimentally investigated in various concentrations and heat fluxes. Microstructured surfaces with a wide range of well-defined surface roughness were fabricated, and a heat flux between 1.5-86 kW/m2 was achieved under atmospheric conditions. The Results indicated that surface roughness and concentration of solution increase the bubble departing frequency and nucleation site density with increasing heat flux. The boiling heat transfer coefficient in mixtures of water/DEA increases with increasing concentration of DEA in water. The experimental results were compared with predictions of several used correlations in the literatures. Results showed that the boiling heat transfer coefficients of this case study are much higher than the predicted values by major existing correlations and models. The excellent agreement for bubble departing frequency found between the models of Jackob and Fritz (1966) and experimental data and also the nucleation site density were in close agreement with the model of Paul (1983) data. f bubble departure frequency, 1/s or Hz N Number of nucleation sites per area per time R c Minimum cavity size, m D c critical diameter, m g gravitational acceleration, m/s2 ρ density, kg/m3 T temperature, °c ΔT temperature difference, °c d d vapor bubble diameter, m h fg enthalpy of vaporization, J/kg R Roughness, μm Ja Jakob number cp specific heat, J/kg °c Pr Prandtl number Ar Archimedes number h Heat transfer coefficient, J/(m2 °c) tg time it takes to grow a bubble, s q/A heat flux (kW/m2) tw time required to heat the layer, s gc Correction coefficient of incompatible units R a Surface

  11. Apparent rate constant mapping using hyperpolarized [1-(13) C]pyruvate

    DEFF Research Database (Denmark)

    Khegai, O.; Schulte, R. F.; Janich, M. A.

    2014-01-01

    Hyperpolarization of [1-13C]pyruvate in solution allows real-time measurement of uptake and metabolism using MR spectroscopic methods. After injection and perfusion, pyruvate is taken up by the cells and enzymatically metabolized into downstream metabolites such as lactate, alanine, and bicarbona...

  12. Iodine uptake by spinach (Spinacia oleracea L.) plants grown in solution culture: effects of iodine species and solution concentrations.

    Science.gov (United States)

    Zhu, Y-G; Huang, Y-Z; Hu, Y; Liu, Y-X

    2003-04-01

    A hydroponic experiment was carried out to investigate the effects of iodine species and solution concentrations on iodine uptake by spinach (Spinacia oleracea L.). Five iodine concentrations (0, 1, 10, 50 and 100 microM) for iodate (IO(3)(-)) and iodide (I(-)) were used. Results show that higher concentrations of I(-) (> or =10 microM) had some detrimental effect on plant growth, while IO(3)(-) had little effect on the biomass production of spinach plants. Increases in iodine concentration in the growth solution significantly enhanced I concentrations in plant tissues. The detrimental effect of I(-) on plant growth was probably due to the excessively high accumulation of I in plant tissues. The solution-to-spinach leaf transfer factors (TF(leaf), fresh weight basis) for plants treated with iodide were between 14.2 and 20.7 at different solution concentrations of iodide; TF(leaf) for plants treated with iodate decreased gradually from 23.7 to 2.2 with increasing solution concentrations of iodate. The distribution coefficients (DCs) of I between leaves and roots were constantly higher for plants treated with iodate than those treated with iodide. DCs for plants treated with iodide increased with increasing solution concentrations of iodide, while DCs for plants treated with iodate (around 5.5) were similar across the range of solution concentrations of iodate used in this experiment. The implications of iodine accumulation in leafy vegetables in human iodine nutrition are also discussed. Copyright 2002 Elsevier Science Ltd.

  13. Isolated effects of external bath osmolality, solute concentration, and electrical charge on solute transport across articular cartilage.

    Science.gov (United States)

    Pouran, Behdad; Arbabi, Vahid; Zadpoor, Amir A; Weinans, Harrie

    2016-12-01

    The metabolic function of cartilage primarily depends on transport of solutes through diffusion mechanism. In the current study, we use contrast enhanced micro-computed tomography to determine equilibrium concentration of solutes through different cartilage zones and solute flux in the cartilage, using osteochondral plugs from equine femoral condyles. Diffusion experiments were performed with two solutes of different charge and approximately equal molecular weight, namely iodixanol (neutral) and ioxaglate (charge=-1) in order to isolate the effects of solute's charge on diffusion. Furthermore, solute concentrations as well as bath osmolality were changed to isolate the effects of steric hindrance on diffusion. Bath concentration and bath osmolality only had minor effects on the diffusion of the neutral solute through cartilage at the surface, middle and deep zones, indicating that the diffusion of the neutral solute was mainly Fickian. The negatively charged solute diffused considerably slower through cartilage than the neutral solute, indicating a large non-Fickian contribution in the diffusion of charged molecules. The numerical models determined maximum solute flux in the superficial zone up to a factor of 2.5 lower for the negatively charged solutes (charge=-1) as compared to the neutral solutes confirming the importance of charge-matrix interaction in diffusion of molecules across cartilage. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  14. Ion permeabilities in mouse sperm reveal an external trigger for SLO3-dependent hyperpolarization.

    Directory of Open Access Journals (Sweden)

    Julio C Chávez

    Full Text Available Unlike most cells of the body which function in an ionic environment controlled within narrow limits, spermatozoa must function in a less controlled external environment. In order to better understand how sperm control their membrane potential in different ionic conditions, we measured mouse sperm membrane potentials under a variety of conditions and at different external K(+ concentrations, both before and after capacitation. Experiments were undertaken using both wild-type, and mutant mouse sperm from the knock-out strain of the sperm-specific, pH-sensitive, SLO3 K(+ channel. Membrane voltage data were fit to the Goldman-Hodgkin-Katz equation. Our study revealed a significant membrane permeability to both K(+ and Cl(- before capacitation, as well as Na(+. The permeability to both K(+ and Cl(- has the effect of preventing large changes in membrane potential when the extracellular concentration of either ion is changed. Such a mechanism may protect against undesired shifts in membrane potential in changing ionic environments. We found that a significant portion of resting membrane potassium permeability in wild-type sperm was contributed by SLO3 K(+ channels. We also found that further activation of SLO3 channels was the essential mechanism producing membrane hyperpolarization under two separate conditions, 1 elevation of external pH prior to capacitation and 2 capacitating conditions. Both conditions produced a significant membrane hyperpolarization in wild-type which was absent in SLO3 mutant sperm. Hyperpolarization in both conditions may result from activation of SLO3 channels by raising intracellular pH; however, demonstrating that SLO3-dependent hyperpolarization is achieved by an alkaline environment alone shows that SLO3 channel activation might occur independently of other events associated with capacitation. For example sperm may undergo stages of membrane hyperpolarization when reaching alkaline regions of the female genital tract

  15. Accurate Description of Calcium Solvation in Concentrated Aqueous Solutions

    Czech Academy of Sciences Publication Activity Database

    Kohagen, Miriam; Mason, Philip E.; Jungwirth, Pavel

    2014-01-01

    Roč. 118, č. 28 (2014), s. 7902-7909 ISSN 1520-6106 R&D Projects: GA ČR GBP208/12/G016; GA MŠk LH12001 Institutional support: RVO:61388963 Keywords : calcium chloride * aqueous solution * molecular dynamics * neutron scattering Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.302, year: 2014

  16. Plutonium solution in concentration range from 8 to 17 G/liter

    Energy Technology Data Exchange (ETDEWEB)

    Rothe, R.E.

    1997-06-01

    This paper very briefly discusses the need for a fundamental criticality study of low concentrations of plutonium solutions. Examples of the occurrence of such solutions, which are characteristic of waste, are cited. Due to the prevalence of decontaminating and decommissioning activities, low concentration solutions are expected to become an important concern. Technical deficiencies in previous calculations are also discussed as a reason for performing low concentration criticality studies. 3 refs.

  17. Plutonium solution in concentration range from 8 to 17 G/liter

    International Nuclear Information System (INIS)

    Rothe, R.E.

    1997-01-01

    This paper very briefly discusses the need for a fundamental criticality study of low concentrations of plutonium solutions. Examples of the occurrence of such solutions, which are characteristic of waste, are cited. Due to the prevalence of decontaminating and decommissioning activities, low concentration solutions are expected to become an important concern. Technical deficiencies in previous calculations are also discussed as a reason for performing low concentration criticality studies. 3 refs

  18. The use of erbium fiber laser relaxation frequency for sensing refractive index and solute concentration of aqueous solutions

    International Nuclear Information System (INIS)

    Arellano-Sotelo, H; Barmenkov, Yu O; Kir'yanov, A V

    2008-01-01

    We report a novel-principle fiber-laser intra-cavity sensor for measuring refractive index and solute concentration of aqueous solutions. The sensor operation is based on a variation of the laser oscillation relaxation frequency (the measured parameter), sensitive to the intra-cavity loss change. The sensor capacity is demonstrated on the example of measurements of sugar concentration in water. A modeling of the sensor operation is presented, allowing its performance optimization

  19. Whispering Gallery Mode Based Optical Fiber Sensor for Measuring Concentration of Salt Solution

    Directory of Open Access Journals (Sweden)

    Chia-Chin Chiang

    2013-01-01

    Full Text Available An optical fiber solution-concentration sensor based on whispering gallery mode (WGM is proposed in this paper. The WGM solution-concentration sensors were used to measure salt solutions, in which the concentrations ranged from 1% to 25% and the wavelength drifted from the left to the right. The experimental results showed an average sensitivity of approximately 0.372 nm/% and an R2 linearity of 0.8835. The proposed WGM sensors are of low cost, feasible for mass production, and durable for solution-concentration sensing.

  20. An isotherm-based thermodynamic model of multicomponent aqueous solutions, applicable over the entire concentration range.

    Science.gov (United States)

    Dutcher, Cari S; Ge, Xinlei; Wexler, Anthony S; Clegg, Simon L

    2013-04-18

    In previous studies (Dutcher et al. J. Phys. Chem. C 2011, 115, 16474-16487; 2012, 116, 1850-1864), we derived equations for the Gibbs energy, solvent and solute activities, and solute concentrations in multicomponent liquid mixtures, based upon expressions for adsorption isotherms that include arbitrary numbers of hydration layers on each solute. In this work, the long-range electrostatic interactions that dominate in dilute solutions are added to the Gibbs energy expression, thus extending the range of concentrations for which the model can be used from pure liquid solute(s) to infinite dilution in the solvent, water. An equation for the conversion of the reference state for solute activity coefficients to infinite dilution in water has been derived. A number of simplifications are identified, notably the equivalence of the sorption site parameters r and the stoichiometric coefficients of the solutes, resulting in a reduction in the number of model parameters. Solute concentrations in mixtures conform to a modified Zdanovskii-Stokes-Robinson mixing rule, and solute activity coefficients to a modified McKay-Perring relation, when the effects of the long-range (Debye-Hückel) term in the equations are taken into account. Practical applications of the equations to osmotic and activity coefficients of pure aqueous electrolyte solutions and mixtures show both satisfactory accuracy from low to high concentrations, together with a thermodynamically reasonable extrapolation (beyond the range of measurements) to extreme concentration and to the pure liquid solute(s).

  1. Reactivity of the cadmium ion in concentrated phosphoric acid solutions.

    Science.gov (United States)

    De Gyves, J; Gonzales, J; Louis, C; Bessiere, J

    1989-07-01

    The solvation transfer coefficients which characterize the changes of ion reactivity with phosphoric acid concentration have been calculated for cadmium from the constants of the successive chloride complexes, and for silver and diethyldithiophosphate from potentiometric measurements. They evidence the strong desolvation of the cadmium species in concentrated phosphoric acid media, causing a remarkable increase of its reactivity. They allow the results of liquid-liquid extraction, precipitation and flotation reactions to be correctly interpreted and their changes to be foreseen when the reagents are modified.

  2. Sedimentation Characteristics of Kaolin and Bentonite in Concentrated Solutions

    Directory of Open Access Journals (Sweden)

    Abdulah Obut

    2005-11-01

    Full Text Available The sedimentation characteristics of two clays, namely kaolinite and bentonite, were determinated at high clay (5 % wt/vol and electrolyte (1 N concentrations using various inorganic-organic compounds. It was observed that the settling behaviour of kaolinite (1:1 clay and montmorillonite (2:1 clay is quite different due to the structural differences between these minerals. Although, similar initial settling rates and final sediment volumes were obtained after 24 hours of settling time for kaolin suspensions, the corresponding rates and volumes for bentonite suspensions varied greatly with the used chemical compound. According to the experimental results, a further intensive theoretical and experimental investigation is needed to reveal the mechanism underlying the sedimentation characteristics of clay minerals at high clay and electrolyte concentrations.

  3. Influence of starch origin on rheological properties of concentrated aqueous solutions

    Directory of Open Access Journals (Sweden)

    Stojanović Željko P.

    2011-01-01

    Full Text Available The rheological properties of corn and potato starch concentrated aqueous solutions were investigated at 25ºC. The starches were previously dispersed in water and the solutions were obtained by heating of dispersions at 115-120ºC for 20 minutes. The solutions of potato starch were transparent, while the corn starch solutions were opalescent. The results of dynamic mechanical measurements showed that the values of viscosity, h, storage modulus, G′, and loss modulus, G″, of the corn starch solutions increased with the storage time. This phenomenon was not observed for the potato starch solutions. It was assumed that the increase of h, G′ and G″ is the result of starch solutions retrogradation. The potato starch solutions retrogradation did not occur probably because of the phosphates presence. The viscosity of 2 mass % corn starch solution is less than the viscosity of 2 mass % potato starch solution. By increasing the concentration of corn starch solution the gel with elastic behavior was formed. The corn starch solutions formed gel as early as at 4 mass % concentration, while potato starch solutions achieved the gel state at the concentration of 5 mass %. The value of exponent m (G′ and G″ µ wm during the transition of potato starch solutions to gel is 0.414, which gives the fractal dimensions for corn starch of 2.10. The obtained value of fractal dimension corresponds to slow aggregation. The corn starch solutions with the starch concentrations higher than 4 mass % form weak gels. For these solutions the values of modulus in rubber plateau were determined. It was found that the modulus in rubber plateau increased with the concentration by the exponent of 4.36. Such high exponent value was obtained in the case when the tridimensional network is formed, i.e. when supermolecular structures like associates or crystal domains are formed.

  4. Genealogical series method. Hyperpolar points screen effect

    International Nuclear Information System (INIS)

    Gorbatov, A.M.

    1991-01-01

    The fundamental values of the genealogical series method -the genealogical integrals (sandwiches) have been investigated. The hyperpolar points screen effect has been found. It allows one to calculate the sandwiches for the Fermion systems with large number of particles and to ascertain the validity of the iterated-potential method as well. For the first time the genealogical-series method has been realized numerically for the central spin-independent potential

  5. Hyperpolarized H2O MR angiography

    DEFF Research Database (Denmark)

    Ardenkjær-Larsen, Jan Henrik; Laustsen, Christoffer; Bowen, Sean

    2014-01-01

    polarization followed by dissolution in D2O. A water 1H signal enhancement of 77 times compared with 4.7 Tesla was obtained. This corresponds to a polarization of 3.5% for the 3.9 mol/L 1H in D2O . Moreover, a T1 in excess of 20 s was achieved. The use of hyperpolarized water as a contrast agent presents a new...

  6. Evanescent Wave Absorption Based Fiber Sensor for Measuring Glucose Solution Concentration

    Science.gov (United States)

    Marzuki, Ahmad; Candra Pratiwi, Arni; Suryanti, Venty

    2018-03-01

    An optical fiber sensor based on evanescent wave absorption designed for measuring glucose solution consentration was proposed. The sensor was made to detect absorbance of various wavelength in the glucose solution. The sensing element was fabricated by side polishing of multimode polymer optical fiber to form a D-shape. The sensing element was immersed in different concentration of glucoce solution. As light propagated through the optical fiber, the evanescent wave interacted with the glucose solution. Light was absorbed by the glucose solution. The larger concentration the glucose solution has, the more the evanescent wave was absorbed in particular wavelenght. Here in this paper, light absorbtion as function of glucose concentration was measured as function of wavelength (the color of LED). We have shown that the proposed sensor can demonstrated an increase of light absorption as function of glucose concentration.

  7. A new method to measure effective soil solution concentration predicts copper availability to plants.

    Science.gov (United States)

    Zhang, H; Zhao, F J; Sun, B; Davison, W; McGrath, S P

    2001-06-15

    Risk assessments of metal contaminated soils need to address metal bioavailability. To predict the bioavailability of metals to plants, it is necessary to understand both solution and solid phase supply processes in soils. In striving to find surrogate chemical measurements, scientists have focused either on soil solution chemistry, including free ion activities, or operationally defined fractions of metals. Here we introduce the new concept of effective concentration, CE, which includes both the soil solution concentration and an additional term, expressed as a concentration, that represents metal supplied from the solid phase. CE was measured using the technique of diffusive gradients in thin films (DGT) which, like a plant, locally lowers soil solution concentrations, inducing metal supply from the solid phase, as shown by a dynamic model of the DGT-soil system. Measurements of Cu as CE, soil solution concentration, by EDTA extraction and as free Cu2+ activity in soil solution were made on 29 different soils covering a large range of copper concentrations. Theywere compared to Cu concentrations in the plant material of Lepidium heterophyllum grown on the same soils. Plant concentrations were linearly related and highly correlated with CE but were more scattered and nonlinear with respect to free Cu2+ activity, EDTA extraction, or soil solution concentrations. These results demonstrate that the dominant supply processes in these soils are diffusion and labile metal release, which the DGT-soil system mimics. The quantity CE is shown to have promise as a quantitative measure of the bioavailable metal in soils.

  8. Soil solution Ni concentrations over which Kd is constant in Japanese agricultural soils

    International Nuclear Information System (INIS)

    Kamei-Ishikawa, Nao; Uchida, Shigeo; Tagami, Keiko; Satta, Naoya

    2011-01-01

    The soil-soil solution distribution coefficient (K d ) is one of the most important parameters required by the models used for radioactive waste disposal environmental impact assessment. The models are generally based on the assumption that K d is independent of the element concentration in soil solution. However, at high soil solution concentrations, this assumption is not valid. Since the sorption of most radionuclides in soil is influenced by their stable isotope concentrations, it is necessary to consider if the range in the naturally occurring stable isotope concentrations in the soil solution is within the range over which K d is valid. The objective of this study was to determine if the K d for nickel (Ni) can be assumed to be constant over the ranges of stable Ni concentration in five main Japanese agricultural soil types. To obtain Ni sorption isotherms for five Japanese soils, two types of batch sorption tests were carried out using radioactive 63 Ni as a tracer. The concentration at which the relationship between soil and soil solution concentration became nonlinear was determined using the two types of sorption isotherms: the Langmuir and Henry isotherms. The result showed that the Ni concentration in the soil solution at which the assumption of a constant K d becomes valid is at least ten times higher than the natural Ni concentrations in solutions of Japanese agricultural soils. This value is sufficient to treat K d for Ni as constant for environmental impact assessment models for the disposal of radioactive waste. (author)

  9. Problems of evaluating isotope analysis of concentrated salt solutions in potash mines

    International Nuclear Information System (INIS)

    Schmiedl, H.D.

    1980-01-01

    Three problems of quantitative evaluation of analytic D and 18 O isotope data of concentrated salt solutions are discussed: (1) Consideration of the influence of admixtures of hydrated salts in determining meteoric or marine water fractions in a concentrated salt solution, (2) analytic accuracy and detection limits in determining meteoric water in salt solutions, and (3) processes of isotopic exchange with reservoir rock and sample matrix

  10. Nanodiamond-enhanced MRI via in situ hyperpolarization

    Science.gov (United States)

    Waddington, David E. J.; Sarracanie, Mathieu; Zhang, Huiliang; Salameh, Najat; Glenn, David R.; Rej, Ewa; Gaebel, Torsten; Boele, Thomas; Walsworth, Ronald L.; Reilly, David J.; Rosen, Matthew S.

    2017-04-01

    Nanodiamonds are of interest as nontoxic substrates for targeted drug delivery and as highly biostable fluorescent markers for cellular tracking. Beyond optical techniques, however, options for noninvasive imaging of nanodiamonds in vivo are severely limited. Here, we demonstrate that the Overhauser effect, a proton-electron polarization transfer technique, can enable high-contrast magnetic resonance imaging (MRI) of nanodiamonds in water at room temperature and ultra-low magnetic field. The technique transfers spin polarization from paramagnetic impurities at nanodiamond surfaces to 1H spins in the surrounding water solution, creating MRI contrast on-demand. We examine the conditions required for maximum enhancement as well as the ultimate sensitivity of the technique. The ability to perform continuous in situ hyperpolarization via the Overhauser mechanism, in combination with the excellent in vivo stability of nanodiamond, raises the possibility of performing noninvasive in vivo tracking of nanodiamond over indefinitely long periods of time.

  11. Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

    Institute of Scientific and Technical Information of China (English)

    WANG Zixiao; YU Lei; LIU Zhiyong; SONG Ning

    2015-01-01

    Effect of an organic corrosion inhibitor (OCI) named PCI-2014 added in chloride solution on the critical chlo-ride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chlo-ride solution were investigated. The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution. Within a certain chloride ion concentration range, the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution. Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer. Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

  12. Isolation of transplutonium elements on ion exchangers from solutions of high salt concentration

    International Nuclear Information System (INIS)

    Guseva, L.I.; Tikhomirova, G.S.; Stepushkina, V.V.

    1985-01-01

    The behaviour of transplutonium elements (TPE) on cation and anion exchangers in aqueous alcoholic solutions of chlorides and nitrates of some alkali and alkaline earth metals depending on different factors: salt concentration, content of alcohol and of acid in the solution as well as the nature of a cation was studied. The data obtained were used to determine the optimal conditions of concentration of TPE on ion exchangers from solutions containing great quantities of salts. The advantages of the use of aqueous alcoholic solutions of nitric acid in the isolation of TPE are shown. (author)

  13. Investigation into sorption of uranium fron its high-concentrated nitric acid solutions on resin AMP

    International Nuclear Information System (INIS)

    Savel'eva, V.I.; Sudarikov, B.N.; Kireeva, G.N.; Ryzhkova, V.N.; Kandaryuk, V.V.

    1976-01-01

    Sorption of uranium has been studied on strongly basic anion-exchange resin from nitric acid solutions with concentration in metal 10-150 g/l in presence of sodium, calcium, and aluminium nitrates. Sorption of uranium from solutions has been performed by the static method with the aid of contacting the initial solution with airdry resin for 4 hours, resin to solution ratio being 1:12.5. It has been established that sorption of uranium increases with a rise in concentration of salting out agents in the following order: Al(NO 3 ) 3 > Ca(NO 3 ) 2 > Na(NO 3 ). It has been shown spectrophotometricatly that in solutions of nitrates and HNO 3 with a concentration 3 exceeds 6 mol/l

  14. Anomalous concentration gradient in NaI solutions inadvertently frozen in transit

    International Nuclear Information System (INIS)

    Billinghurst, M.W.; Abrams, D.N.; Coutts, A.D.

    1990-01-01

    Therapeutic doses of iodine-131 ( 131 I) are frequently dispensed volumetrically from a stock vial containing a solution of sodium iodide. During the winter months the authors have observed that initial aliquots do not always have the same radioactive concentration as that calculated for the bulk solution. In order to evaluate the cause and extent of this problem, they prepared a stock solution of low radioactive concentration sodium iodide with the same concentration of sodium thiosulfate and pH as that in the stock therapeutic iodine vial. Aliquots of this solution were transferred to plastic tubes and were stored at various temperatures. These results clearly show that when there is a risk of freezing during transportation of therapeutic solutions of sodium iodide it is essential to physically mix the liquid once thawing is complete if therapeutic doses are to be dispensed accurately on a volume basis

  15. Effect of calcium chelators on physical changes in casein micelles in concentrated micellar casein solutions

    NARCIS (Netherlands)

    Kort, de E.J.P.; Minor, M.; Snoeren, T.H.M.; Hooijdonk, van A.C.M.; Linden, van der E.

    2011-01-01

    The effect of calcium chelators on physical changes of casein micelles in concentrated micellar casein solutions was investigated by measuring calcium-ion activity, viscosity and turbidity, and performing ultracentrifugation. The highest viscosities were measured on addition of sodium

  16. Radiolysis of concentrated solutions. 2. Pulse and #betta#-radiolysis studies of direct and indirect effects in lithium iodide solutions

    International Nuclear Information System (INIS)

    Hadjadj, A.; Julien, R.; Pucheault, J.; Ferradini, C.; Hickel, B.

    1982-01-01

    In the preceding study of the radiolysis of concentrated aqueous LiCl solutions, one of the hypotheses used to explain the apparent inefficacy of Cl 2- formation by the direct effect was that molecular chlorine, not detectable by spectrophotometry, could be formed during the early stages of water radiolysis. Such an hypothesis is confirmed here for pulse and #betta#-radiolysis of concentrated aqueous neutral LiI solutions. Indeed, it is shown that, 10 ns after the pulse, molecular iodine, detected as I 3- , is formed with a yield that increases with the LiI concentration. The experimental results yields values of 4.8 and 7.3 respectively for the indirect and direct effects of total oxidation G/sub I 2- / + 2G/sub I 3- /. This last high value is discussed

  17. In vitro reduction of dental erosion by low-concentration TiF4 solutions

    NARCIS (Netherlands)

    Vieira, A.M.; Ruben, J.L.; Bronkhorst, E.M.; Huysmans, M.C.D.N.J.M.

    2011-01-01

    The aims of this study were to compare daily versus single applications of low-concentration TiF(4) solutions for reduction of enamel erosion and to evaluate the enamel surface loss due to application of these solutions. Sixty bovine enamel samples were randomly divided into 2 groups: single versus

  18. Computation of major solute concentrations and loads in German rivers using regression analysis.

    Science.gov (United States)

    Steele, T.D.

    1980-01-01

    Regression functions between concentrations of several inorganic solutes and specific conductance and between specific conductance and stream discharge were derived from intermittent samples collected for 2 rivers in West Germany. These functions, in conjunction with daily records of streamflow, were used to determine monthly and annual solute loadings. -from Author

  19. In vitro Reduction of Dental Erosion by Low-Concentration TiF4 Solutions

    NARCIS (Netherlands)

    Vieira, A. M.; Ruben, J. L.; Bronkhorst, E. M.; Huysmans, M. C. D. N. J. M.

    2011-01-01

    The aims of this study were to compare daily versus single applications of low-concentration TiF4 solutions for reduction of enamel erosion and to evaluate the enamel surface loss due to application of these solutions. Sixty bovine enamel samples were randomly divided into 2 groups: single versus

  20. Modelling trends in soil solution concentrations under five forest-soil combinations in the Netherlands

    NARCIS (Netherlands)

    Salm, van der C.; Vries, de W.; Kros, J.

    1996-01-01

    The influence of forest and soil properties on changes in soil solution concentration upon a reduction deposition was examined for five forest-soil combinations with the dynamic RESAM model. Predicted concentrations decreased in the direction Douglas fir - Scotch pine - oak, due to decreased

  1. Characterization of Chemical Exchange Using Relaxation Dispersion of Hyperpolarized Nuclear Spins.

    Science.gov (United States)

    Liu, Mengxiao; Kim, Yaewon; Hilty, Christian

    2017-09-05

    Chemical exchange phenomena are ubiquitous in macromolecules, which undergo conformational change or ligand complexation. NMR relaxation dispersion (RD) spectroscopy based on a Carr-Purcell-Meiboom-Gill pulse sequence is widely applied to identify the exchange and measure the lifetime of intermediate states on the millisecond time scale. Advances in hyperpolarization methods improve the applicability of NMR spectroscopy when rapid acquisitions or low concentrations are required, through an increase in signal strength by several orders of magnitude. Here, we demonstrate the measurement of chemical exchange from a single aliquot of a ligand hyperpolarized by dissolution dynamic nuclear polarization (D-DNP). Transverse relaxation rates are measured simultaneously at different pulsing delays by dual-channel 19 F NMR spectroscopy. This two-point measurement is shown to allow the determination of the exchange term in the relaxation rate expression. For the ligand 4-(trifluoromethyl)benzene-1-carboximidamide binding to the protein trypsin, the exchange term is found to be equal within error limits in neutral and acidic environments from D-DNP NMR spectroscopy, corresponding to a pre-equilibrium of trypsin deprotonation. This finding illustrates the capability for determination of binding mechanisms using D-DNP RD. Taking advantage of hyperpolarization, the ligand concentration in the exchange measurements can reach on the order of tens of μM and protein concentration can be below 1 μM, i.e., conditions typically accessible in drug discovery.

  2. Physical Property Modeling of Concentrated Cesium Eluate Solutions, Part I - Derivation of Models

    Energy Technology Data Exchange (ETDEWEB)

    Choi, A.S.; Pierce, R. A.; Edwards, T. B.; Calloway, T. B.

    2005-09-15

    Major analytes projected to be present in the Hanford Waste Treatment Plant cesium ion-exchange eluate solutions were identified from the available analytical data collected during radioactive bench-scale runs, and a test matrix of cesium eluate solutions was designed within the bounding concentrations of those analytes. A computer model simulating the semi-batch evaporation of cesium eluate solutions was run in conjunction with a multi-electrolyte aqueous system database to calculate the physical properties of each test matrix solution concentrated to the target endpoints of 80% and 100% saturation. The calculated physical properties were analyzed statistically and fitted into mathematical expressions for the bulk solubility, density, viscosity, heat capacity and volume reduction factor as a function of temperature and concentration of each major analyte in the eluate feed. The R{sup 2} of the resulting physical property models ranged from 0.89 to 0.99.

  3. In vivo assessment of intracellular redox state in rat liver using hyperpolarized [1-13 C]Alanine.

    Science.gov (United States)

    Park, Jae Mo; Khemtong, Chalermchai; Liu, Shie-Chau; Hurd, Ralph E; Spielman, Daniel M

    2017-05-01

    The intracellular lactate to pyruvate concentration ratio is a commonly used tissue assay biomarker of redox, being proportional to free cytosolic [NADH]/[NAD + ]. In this study, we assessed the use of hyperpolarized [1- 13 C]alanine and the subsequent detection of the intracellular products of [1- 13 C]pyruvate and [1- 13 C]lactate as a useful substrate for assessing redox levels in the liver in vivo. Animal experiments were conducted to measure in vivo metabolism at baseline and after ethanol infusion. A solution of 80-mM hyperpolarized [1- 13 C]alanine was injected intravenously at baseline (n = 8) and 45 min after ethanol infusion (n = 4), immediately followed by the dynamic acquisition of 13 C MRS spectra. In vivo rat liver spectra showed peaks from [1- 13 C] alanine and the products of [1- 13 C]lactate, [1- 13 C]pyruvate, and 13 C-bicarbonate. A significantly increased 13 C-lactate/ 13 C-pyruvate ratio was observed after ethanol infusion (8.46 ± 0.58 at baseline versus 13.58 ± 0.69 after ethanol infusion; P alanine is presented, with the validity of the proposed 13 C-pyruvate/ 13 C-lactate metric tested using an ethanol challenge to alter liver redox state. Magn Reson Med 77:1741-1748, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  4. A path-independent integral for the characterization of solute concentration and flux at biofilm detachments

    Science.gov (United States)

    Moran, B.; Kulkarni, S.S.; Reeves, H.W.

    2007-01-01

    A path-independent (conservation) integral is developed for the characterization of solute concentration and flux in a biofilm in the vicinity of a detachment or other flux limiting boundary condition. Steady state conditions of solute diffusion are considered and biofilm kinetics are described by an uptake term which can be expressed in terms of a potential (Michaelis-Menten kinetics). An asymptotic solution for solute concentration at the tip of the detachment is obtained and shown to be analogous to that of antiplane crack problems in linear elasticity. It is shown that the amplitude of the asymptotic solution can be calculated by evaluating a path-independent integral. The special case of a semi-infinite detachment in an infinite strip is considered and the amplitude of the asymptotic field is related to the boundary conditions and problem parameters in closed form for zeroth and first order kinetics and numerically for Michaelis-Menten kinetics. ?? Springer Science+Business Media, Inc. 2007.

  5. Stilbazolium Merocyanine Dye Determination in Different Solutions, Concentrations and Colloids Using SERS

    DEFF Research Database (Denmark)

    Pajchrowski, Grzegorz; Abdali, Salim; Nørbygaard, Thomas

    2006-01-01

    Surface Enhanced Raman Scattering (SERS) measurements were carried out on stilbazolium merocyanine dye in methanol and pyridine solvents. Both solutions were measured in series of concentrations, covering a range of 5·10-5 M to 5·10-8 M. In these measurements Ag and Au colloids were used and the ......Surface Enhanced Raman Scattering (SERS) measurements were carried out on stilbazolium merocyanine dye in methanol and pyridine solvents. Both solutions were measured in series of concentrations, covering a range of 5·10-5 M to 5·10-8 M. In these measurements Ag and Au colloids were used...... report here on the success of using SERS to obtain Raman spectra of merocyanine dye at very low concentration in an attempt of new approach, which can be used for further investigations of the dye. The SERS spectra will here be reported and the results from different solutions, colloids, concentrations...

  6. Methods to homogenize electrochemical concentration cell (ECC ozonesonde measurements across changes in sensing solution concentration or ozonesonde manufacturer

    Directory of Open Access Journals (Sweden)

    T. Deshler

    2017-06-01

    Full Text Available Ozone plays a significant role in the chemical and radiative state of the atmosphere. For this reason there are many instruments used to measure ozone from the ground, from space, and from balloons. Balloon-borne electrochemical cell ozonesondes provide some of the best measurements of the ozone profile up to the mid-stratosphere, providing high vertical resolution, high precision, and a wide geographic distribution. From the mid-1990s to the late 2000s the consistency of long-term records from balloon-borne ozonesondes has been compromised by differences in manufacturers, Science Pump (SP and ENSCI (EN, and differences in recommended sensor solution concentrations, 1.0 % potassium iodide (KI and the one-half dilution: 0.5 %. To investigate these differences, a number of organizations have independently undertaken comparisons of the various ozonesonde types and solution concentrations, resulting in 197 ozonesonde comparison profiles. The goal of this study is to derive transfer functions to allow measurements outside of standard recommendations, for sensor composition and ozonesonde type, to be converted to a standard measurement and thus homogenize the data to the expected accuracy of 5 % (10 % in the stratosphere (troposphere. Subsets of these data have been analyzed previously and intermediate transfer functions derived. Here all the comparison data are analyzed to compare (1 differences in sensor solution composition for a single ozonesonde type, (2 differences in ozonesonde type for a single sensor solution composition, and (3 the World Meteorological Organization's (WMO and manufacturers' recommendations of 1.0 % KI solution for Science Pump and 0.5 % KI for ENSCI. From the recommendations it is clear that ENSCI ozonesondes and 1.0 % KI solution result in higher amounts of ozone sensed. The results indicate that differences in solution composition and in ozonesonde type display little pressure dependence at pressures

  7. Effect of Sulfide Concentration on Copper Corrosion in Anoxic Chloride-Containing Solutions

    Science.gov (United States)

    Kong, Decheng; Dong, Chaofang; Xu, Aoni; Man, Cheng; He, Chang; Li, Xiaogang

    2017-04-01

    The structure and property of passive film on copper are strongly dependent on the sulfide concentration; based on this, a series of electrochemical methods were applied to investigate the effect of sulfide concentration on copper corrosion in anaerobic chloride-containing solutions. The cyclic voltammetry and x-ray photoelectron spectroscopy analysis demonstrated that the corrosion products formed on copper in anaerobic sulfide solutions comprise Cu2S and CuS. And the corrosion resistance of copper decreased with increasing sulfide concentration and faster sulfide addition, owing to the various structures of the passive films observed by the atomic force microscope and scanning electron microscope. A p-type semiconductor character was obtained under all experimental conditions, and the defect concentration, which had a magnitude of 1022-1023 cm-3, increased with increasing sulfide concentration, resulting in a higher rate of both film growth and dissolution.

  8. ELECTRODIALYSIS IN THE CONVERSION STEP OF THE CONCENTRATED SALT SOLUTIONS IN THE PROCESS OF BATTERY SCRAP

    Directory of Open Access Journals (Sweden)

    S. I. Niftaliev

    2014-01-01

    Full Text Available Summary. The concentrated sodium sulfate solution is formed during the processing of waste battery scrap. A promising way to further treatment of the concentrated salt solution could be the conversion of these salts into acid and bases by electrodialysis, that can be reused in the same technical process cycle. For carrying out the process of conversion of salts into the corresponding acid and base several cells schemes with different combinations of cation, anion and bipolar membranes are used. At this article a comparative analysis of these cells is carried out. In the cells there were used the membranes МC-40, МА-41 and МB-2I. Acid and base solutions with higher concentration may be obtained during the process of electrodialysis in the circulation mode, when a predetermined amount of salt in the closed loop is run through a set of membranes to obtain the desired concentration of the product. The disadvantages of this method are the high cost of buffer tanks and the need to work with small volumes of treated solutions. In industrial applications it is advisable to use continuous electrodialysis with bipolar membranes, since this configuration allows to increase the number of repeating sections, which is necessary to reduce the energy costs. The increase of the removal rate of salts can be achieved by increasing the process steps, and to produce a more concentrated products after the conversion step can be applied electrodialysis-concentrator or evaporator.

  9. Equilibrium and Dynamic Osmotic Behaviour of Aqueous Solutions with Varied Concentration at Constant and Variable Volume

    Science.gov (United States)

    Minkov, Ivan L.; Manev, Emil D.; Sazdanova, Svetla V.; Kolikov, Kiril H.

    2013-01-01

    Osmosis is essential for the living organisms. In biological systems the process usually occurs in confined volumes and may express specific features. The osmotic pressure in aqueous solutions was studied here experimentally as a function of solute concentration (0.05–0.5 M) in two different regimes: of constant and variable solution volume. Sucrose, a biologically active substance, was chosen as a reference solute for the complex tests. A custom made osmotic cell was used. A novel operative experimental approach, employing limited variation of the solution volume, was developed and applied for the purpose. The established equilibrium values of the osmotic pressure are in agreement with the theoretical expectations and do not exhibit any evident differences for both regimes. In contrast, the obtained kinetic dependences reveal striking divergence in the rates of the process at constant and varied solution volume for the respective solute concentrations. The rise of pressure is much faster at constant solution volume, while the solvent influx is many times greater in the regime of variable volume. The results obtained suggest a feasible mechanism for the way in which the living cells rapidly achieve osmotic equilibrium upon changes in the environment. PMID:24459448

  10. Radiolysis of concentrated solutions. 1. Pulse and γ radiolysis studies of direct and indirect effects in LiCl solutions

    International Nuclear Information System (INIS)

    Pucheault, J.; Ferradini, C.; Julien, R.; Deysine, A.; Gilles, L.; Moreau, M.

    1979-01-01

    This study of the radiolysis of concentrated aqueous LiCl solutions enables the relative contributions of the direct and indirect effects to be evaluated as a function of Cl - concentration and also permits an evaluation of the role of Cl - in the early stages of water radiolysis. Radicalar and molecular yields G/sub Cl 2 - /, G/sub OH/, G//sub e//sub aq/ - / + G/sub H/, G/sub H 2 O 2 /, and G/sub H 2 / are determined for all concentrations employed, and the material balance is verified. The main conclusions concerning the apparent inefficacy of the direct effect and the importance of OH scavenging in spurs are discussed

  11. Passivation behavior of a ferritic stainless steel in concentrated alkaline solutions

    Directory of Open Access Journals (Sweden)

    Arash Fattah-alhosseini

    2015-10-01

    Full Text Available The passivation behavior of AISI 430 ferritic stainless steel was investigated in concentrated alkaline solutions in relation to several test parameters, using electrochemical techniques. Increasing solution pH (varying from 11.5 to 14.0 leads to an increase in the corrosion rate of the alloy. Mott–Schottky analysis revealed that passive films formed on AISI 430 ferritic stainless steel behave as n-type semiconductor and the donor densities increased with pH. Electrochemical impedance spectroscopy (EIS results showed that the reciprocal capacitance of the passive film is directly proportional to its thickness, which decreases with pH increase. The results revealed that for this ferritic stainless steel in concentrated alkaline solutions, decreasing the solution pH offers better conditions for forming passive films with higher protection behavior, due to the growth of a much thicker and less defective film.

  12. Separation and Concentration of Succinic Adic from Multicomponent Aqueous Solutions by Nanofiltration Technique

    Directory of Open Access Journals (Sweden)

    Antczak Jerzy

    2014-06-01

    Full Text Available This paper applies the determined suitability of nanofiltration (NF membrane separation for selective isolation and concentration of succinic acid from aqueous solutions which are post-fermentation multicomponent fluids. The study analyzed the influence of concentration and the pH of the separated solutions on the efficiency and selectivity of NF process that runs in a module equipped with a ceramic membrane. Moreover, the effect of applied trans-membrane pressure on the retention of succinic acid and sodium succinate has been studied. The investigations have shown that in the used NF module the retention of succinic acid salt is equal almost 50% in the case of a three-component model solution, although the degree of retention depends on both the transmembrane pressure and the initial concentration of separated salt.

  13. Ammonia complexes of metals in aqueous solutions with high concentrations of ammonia

    International Nuclear Information System (INIS)

    Padar, T.G.; Novikov, L.K.; Stupko, T.V.; Isaev, I.D.; Pashkov, G.L.; Mironov, V.E.

    1991-01-01

    Potentiometric method, glass electrodes and Bierrum function were used to study the formation of ammonia complexes of magnesium, calcium, cadmium, zinc, copper(2) and silver in 2.0 mol/dm 3 aqueous solutions of ammonia nitrate with 0-18 mol/dm 3 ammonia concentrations at 25.0 deg C. Step constants of stability of studied complexes were calculated and their compositions were determined with account of nonideal character of aqueous-salt solutions with ammonia concentrations above 1.0 mol/dm 3 . Values of correction effects on salting out ammonia action for Bierrum function in solutions with 1.0-18 mol/dm 3 ammonia concentrations were found

  14. Determination of the uranium concentration in soil solutions by the fission track registration technique

    International Nuclear Information System (INIS)

    Fernandes, G.P.

    1980-02-01

    The fission tracks registration technique was used to determine the uranium concentration in soil solutions. The Makrofol KG, a synthetic plastic manufactured by Bayer, was used as a detector and the wet method was applied. From the calibration curves obtained, it was possible to determine uranium concentrations in soil solutions, from 90 to 320 μg U/l, with an error between 9.4% and 4.0%, respectively. The method was applied to a few soil samples from Pocos de Caldas, Minas Gerais in Brazil. The uranium concentrations in the sample and residues were also determined by other methods to compare the results obtained; only one sample showed deviation from the results obtained by the fission tracks method. And this discrepancy was explained in a reasonable way. It was shown that the fission tracks technique can be used with sucess for application in soil solutions. (Author) [pt

  15. Hydrogen-bonded structure in highly concentrated aqueous LiBr solutions

    International Nuclear Information System (INIS)

    Imano, Masahiro; Kameda, Yasuo; Usuki, Takeshi; Uemura, Osamu

    2001-01-01

    Neutron diffraction measurements were carried out for H/D isotopically substituted aqueous 10, 25 and 33 mol% LiBr solutions in order to obtain structural information on the intermolecular hydrogen bonds among water molecules in highly concentrated aqueous solutions. Observed scattering cross sections for D 2 O (99.9 % D), 0 H 2 O(35.9 % D) and 0-2 H 2 O(68.0 % D) solutions were combined to deduce partial structure factors, a HH (Q), a XH (Q) and a XX (Q) (X: O, Br and Li). The least squares fitting analysis was applied to the observed partial structure factors to determine the nearest neighbor interatomic distance, root-mean-square amplitude and coordination number. Intermolecular distances, r OH =1.91(1) A, r HH =2.38(1) A and r OO =3.02(1) A, between the nearest neighbor water molecules, were obtained for the 10 mol% LiBr solution. On the other hand, the intermolecular O···H interaction was found to almost disappear in concentrated 25 and 33 mol% LiBr solutions. The result implies that the hydrogen-bonded network is completely broken in highly concentrated aqueous LiBr solutions. (author)

  16. Hyperpolarized nanodiamond with long spin-relaxation times

    Science.gov (United States)

    Rej, Ewa; Gaebel, Torsten; Boele, Thomas; Waddington, David E. J.; Reilly, David J.

    2015-10-01

    The use of hyperpolarized agents in magnetic resonance, such as 13C-labelled compounds, enables powerful new imaging and detection modalities that stem from a 10,000-fold boost in signal. A major challenge for the future of the hyperpolarization technique is the inherently short spin-relaxation times, typically nanodiamond can be hyperpolarized at cryogenic and room temperature without the use of free radicals, and, owing to their solid-state environment, exhibit relaxation times exceeding 1 h. Combined with the already established applications of nanodiamonds in the life sciences as inexpensive fluorescent markers and non-cytotoxic substrates for gene and drug delivery, these results extend the theranostic capabilities of nanoscale diamonds into the domain of hyperpolarized magnetic resonance.

  17. Critical zone structure controls concentration-discharge relationships and solute generation in forested tropical montane watersheds

    Science.gov (United States)

    Wymore, Adam S.; Brereton, Richard L.; Ibarra, Daniel E.; Maher, Kate; McDowell, William H.

    2017-07-01

    Concentration-discharge (C-Q) relationships are poorly known for tropical watersheds, even though the tropics contribute a disproportionate amount of solutes to the global ocean. The Luquillo Mountains in Puerto Rico offer an ideal environment to examine C-Q relationships across a heterogeneous tropical landscape. We use 10-30 years of weekly stream chemistry data across 10 watersheds to examine C-Q relationships for weathering products (SiO2(aq), Ca2+, Mg2+, and Na+) and biologically controlled solutes (dissolved organic carbon [DOC], dissolved organic nitrogen [DON], NH4+, NO3-, PO43-, K+, and SO42-). We analyze C-Q relationships using power law equations and a solute production model and use principal component analysis to test hypotheses regarding how the structure of the critical zone controls solute generation. Volcaniclastic watersheds had higher concentrations of weathering solutes and smaller tributaries were approximately threefold more efficient at generating these solutes than larger rivers. Lithology and vegetation explained a significant amount of variation in the theoretical maximum concentrations of weathering solutes (r2 = 0.43-0.48) and in the C-Q relationships of PO43- (r2 = 0.63) and SiO2(aq) (r2 = 0.47). However, the direction and magnitude of these relationships varied. Across watersheds, various forms of N and P displayed variable C-Q relationships, while DOC was consistently enriched with increasing discharge. Results suggest that PO43- may be a useful indicator of watershed function. Relationships between C-Q and landscape characteristics indicate the extent to which the structure and function of the Critical zone controls watershed solute fluxes.

  18. 3D Hyperpolarized C-13 EPI with Calibrationless Parallel Imaging

    DEFF Research Database (Denmark)

    Gordon, Jeremy W.; Hansen, Rie Beck; Shin, Peter J.

    2018-01-01

    With the translation of metabolic MRI with hyperpolarized 13C agents into the clinic, imaging approaches will require large volumetric FOVs to support clinical applications. Parallel imaging techniques will be crucial to increasing volumetric scan coverage while minimizing RF requirements and tem...... strategies to accelerate and undersample hyperpolarized 13C data using 3D blipped EPI acquisitions and multichannel receive coils, and demonstrated its application in a human study of [1-13C]pyruvate metabolism....

  19. A NOVEL INTERPRETATION OF CONCENTRATION DEPENDENCE OF VISCOSITY OF DILUTE POLYMER SOLUTION

    Institute of Scientific and Technical Information of China (English)

    Yan Pan; Rong-shi Cheng

    2000-01-01

    The concentration dependence of the reduced viscosity of dilute polymer solution is interpreted in the light of a new concept of the self-association of polymer chains in dilute solution. The apparent self-association constant is defined as the molar association constant divided by the molar mass of individual polymer chain and is numerically interconvertible with the Huggins coefficient. The molar association constant is directly proportional to the effective hydrodynamic volume of the polymer chain in solution and is irrespective of the chain architecture. The effective hydrodynamic volume accounts for the non-spherical conformation of a short polymer chain in solution and is a product of a shape factor and hydrodynamic volume. The observed enhancement of Huggins coefficient for short chain and branched polymer is satisfactorily interpreted by the concept of self-association. The concept of self-association allows us to predict the existence of a boundary concentration Cs (dynamic contact concentration) which divides the dilute polymer solution into two regions.

  20. Influence of Concentration and Agitation of Sodium Hypochlorite and Peracetic Acid Solutions on Tissue Dissolution.

    Science.gov (United States)

    Tanomaru-Filho, Mário; Silveira, Bruna Ramos Franco; Martelo, Roberta Bosso; Guerreiro-Tanomaru, Juliane Maria

    2015-11-01

    To evaluated the tissue dissolution of sodium hypochlorite (NaOCl) and peracetic acid (PA) solutions at different concentrations, with or without ultrasonic agitation. The following solutions were analyzed: 2.5% NaOCl, 0.5, 1 and 2% PA, 1% PA associated with 6.5% hydrogen peroxide (HP) and saline. Fragments of bovine pulp tissue with 25 ± 2g mg were immersed into test tubes containing 4 mL of the solutions for 10 minutes. In the groups with agitation, pulp tissues were submitted to 2 cycles of 1 minute of ultrasonic agitation. The specimens were weighed after the removal from the solutions. The percentage of mass loss was calculated according to the difference of mass before and after exposure to solutions. Data were submitted to ANOVA and Tukey tests (p Peracetic acid solution has pulp tissue dissolution. However, this ability is lower than 2.5% NaOCl solution. The sodium hypochlorite solution shows higher ability to dissolve tissue than PA.

  1. Simulating Osmotic Equilibria: A New Tool for Calculating Activity Coefficients in Concentrated Aqueous Salt Solutions.

    Science.gov (United States)

    Bley, Michael; Duvail, Magali; Guilbaud, Philippe; Dufrêche, Jean-François

    2017-10-19

    Herein, a new theoretical method is presented for predicting osmotic equilibria and activities, where a bulk liquid and its corresponding vapor phase are simulated by means of molecular dynamics using explicit polarization. Calculated time-averaged number density profiles provide the amount of evaporated molecules present in the vapor phase and consequently the vapor-phase density. The activity of the solvent and the corresponding osmotic coefficient are determined by the vapor density at different solute concentrations with respect to the reference vapor density of the pure solvent. With the extended Debye-Hückel equation for the activity coefficient along with the corresponding Gibbs-Duhem relation, the activity coefficients of the solutes are calculated by fitting the osmotic coefficients. A simple model based on the combination of Poisson processes and Maxwell-Boltzmann velocity distributions is introduced to interpret statistical phenomena observed during the simulations, which are related to evaporation and recondensation. This method is applied to aqueous dysprosium nitrate [Dy(NO 3 ) 3 ] solutions at different concentrations. The obtained densities of the liquid bulk and the osmotic and activity coefficients are in good agreement with the experimental results for concentrated and saturated solutions. Density profiles of the liquid-vapor interface at different concentrations provide detailed insight into the spatial distributions of all compounds.

  2. A study on prediction of uranium concentration in pregnant solution from in-situ leaching

    International Nuclear Information System (INIS)

    Yi Weiping; Zhou Quan; Yu Yunzhen; Wang Shude; Yang Yihan; Lei Qifeng

    2005-01-01

    The modeling course on prediction of uranium concentration in pregnant solution from in-situ leaching of uranium is described, a mathematical model based on grey system theory is put forward, and a set of computer application software is correspondingly developed. (authors)

  3. Communication: Modeling of concentration dependent water diffusivity in ionic solutions: Role of intermolecular charge transfer

    Energy Technology Data Exchange (ETDEWEB)

    Yao, Yi; Berkowitz, Max L., E-mail: maxb@unc.edu, E-mail: ykanai@unc.edu; Kanai, Yosuke, E-mail: maxb@unc.edu, E-mail: ykanai@unc.edu [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States)

    2015-12-28

    The translational diffusivity of water in solutions of alkali halide salts depends on the identity of ions, exhibiting dramatically different behavior even in solutions of similar salts of NaCl and KCl. The water diffusion coefficient decreases as the salt concentration increases in NaCl. Yet, in KCl solution, it slightly increases and remains above bulk value as salt concentration increases. Previous classical molecular dynamics simulations have failed to describe this important behavior even when polarizable models were used. Here, we show that inclusion of dynamical charge transfer among water molecules produces results in a quantitative agreement with experiments. Our results indicate that the concentration-dependent diffusivity reflects the importance of many-body effects among the water molecules in aqueous ionic solutions. Comparison with quantum mechanical calculations shows that a heterogeneous and extended distribution of charges on water molecules around the ions due to ion-water and also water-water charge transfer plays a very important role in controlling water diffusivity. Explicit inclusion of the charge transfer allows us to model accurately the difference in the concentration-dependent water diffusivity between Na{sup +} and K{sup +} ions in simulations, and it is likely to impact modeling of a wide range of systems for medical and technological applications.

  4. Removing ferric ions from concentrated acid leaching solution of an uranium ore by jarosite

    International Nuclear Information System (INIS)

    Song Huanbi; Hu Yezang

    1997-01-01

    The author expounds the fundamental rules of removing ferric ions by jarosite and presents results of removing ferric ions from concentrated acid curing-trickle leaching solution of an uranium ore. It turns out that the method can be applied to uranium hydrometallurgical process effectively

  5. Membrane distillation with porous metal hollow fibers for the concentration of thermo-sensitive solutions

    NARCIS (Netherlands)

    Shukla, Sushumna

    2014-01-01

    This thesis presents an original approach for the concentration of thermo-sensitive solutions: the Sweep Gas Membrane Distillation (SGMD) process. A new membrane contactor with metallic hollow fibers has been designed and allows the distillation process to be operational at low temperature. Heat is

  6. The determination of hydroxide and carbonate in concentrated sodium chloride solutions

    NARCIS (Netherlands)

    Roolvink, W.B.; Bos, M.

    1980-01-01

    A computer method for the determination of carbonate and hydroxide in concentrated (2.89 M) sodium chloride solutions is described. The method is based on multiparametric curve-fitting and can also be applied to salts of dibasic acids with unknown equilibrium constants. The systematic error is not

  7. Sodium concentration in home made salt – sugar – solution (sss ...

    African Journals Online (AJOL)

    In a cohort of 210 young mothers, selected through cluster sampling technique from Ogida health district of Egor Local Government Area of Edo State, the electrolyte concentration of prepared salt-sugar-solutions (SSS) were evaluated. This was predicated on the need to determine the effects of introduction of various ...

  8. The relation between temperature and concentration gradients in superfluid sup 3 He- sup 4 He solutions

    CERN Document Server

    Zadorozhko, A A; Rudavskij, E Y; Chagovets, V K; Sheshin, G A

    2003-01-01

    The temperature and concentration gradients nabla T and nabla x in a superfluid sup 3 He- sup 4 He mixture with an initial concentration 9,8 % of sup 3 He are measured in a temperature range 70-500 mK. The gradients are produced by a steady thermal flow with heating from below. It is shown that the value of nabla x/nabla T observed in the experiment is in good agreement with the theoretical model derived from the temperature and concentration dependences of osmotic pressure. The experimental data permitted us to obtain a thermal diffusion ratio of the solution responsible for the thermal diffusion coefficient.

  9. Determination of the unfrozen water content of maximally freeze-concentrated carbohydrate solutions.

    Science.gov (United States)

    Hatley, R H; Mant, A

    1993-08-01

    The heat capacity change at T'g has been studied in freeze-concentrated carbohydrate solutions. The values obtained have been compared with those found for high concentration solutions that do not undergo freezing above Tg. The analysis has indicated that the freezing process influences the degree of stress in the glassy phase. This results in a complex power-time curve when frozen solutions are heated in a differential scanning calorimeter. The endotherm produced by the stress relaxation can cause considerable error in W'g measurement obtained by any method that relies on the integration of the power-time curve. A more reliable method for W'g determination is via the intersection of T'g with a previously prepared Tg/Wg calibration curve.

  10. Interaction of Celestine Concentrate and Reagent Grade SrSO4 with Oxalate Solutions

    Directory of Open Access Journals (Sweden)

    Abdullah Obut

    2012-12-01

    Full Text Available The interaction of reagent grade strontium sulphate and celestine concentrate with aqueous solutions of oxalic acid, sodiumoxalate and ammonium oxalate for the production of strontium carbonate were investigated for different oxalate compound:SrSO4 moleratios and reaction times using x-ray diffraction analysis and dissolution tests. Under the same experimental conditions, it was foundthat aqueous oxalic acid and sodium oxalate solutions had no or little effect on reagent grade strontium sulphate or celestineconcentrate, but aqueous ammonium oxalate solution converted them into strontium oxalate hydrate. Strontium carbonate was obtainedat conversion ratios of 74.7% for the celestine concentrate and 84.6 % for the reagent grade strontium sulphate by the decompositionof the obtained strontium oxalate hydrate at 600 °C under air atmosphere.

  11. Concentration and purification of plutonium solutions by means of ion-exchange columns

    Energy Technology Data Exchange (ETDEWEB)

    Durham, R W; Aikin, A M

    1953-02-15

    Equilibrium experiments using Dowex 50 ion-exchange resin and nitric acid solutions of Pu{sup 3+}, UO{sub 2}{sup 2+}, Fe{sup 2+} cations have yielded values for the absorption affinities for these ions. Trivalent plutonium was found to be far more strongly absorbed than UO{sub 2}{sup 2+} and Fe{sup 2+}. Column studies have shown that uranium can be completely separated from plutonium even when the initial concentration of uranium is very much greater than that of the plutonium. A plutonium concentration increase of about fifty-fold can be obtained from solutions about 10{sup -3} M in plutonium and 1.0M in nitric acid. The equation K{sub Pu}{sup 3+} = X{sub R} (1-X{sub S}){sup 3} C{sub S}{sup 2}/X{sub S} (1-X{sub R}){sup 3} C{sub R}{sup 2} for estimating the maximum amount of plutonium taken up by a column of resin of unit volume from a solution of total equivalent concentration, C{sub S} , has been shown to hold for values of C{sub S} up to 3 equivalents per litre. X{sub R}, the equivalent fraction of plutonium on the resin, is the number of equivalents of plutonium absorbed by the resin divided by the total capacity of the column. X{sub S}, the equivalent fraction of plutonium in solution, is the equivalent concentration of plutonium divided by the total equivalent concentration of cations in solution. C{sub R} is the total capacity of the resin in milli-equivalents per gram of dry resin. Recommendations have been made for the application and operation of ion-exchange columns in the Plutonium-Extraction Plant. (author)

  12. Thermodynamic characteristics of solutions of Bu4NI in dimethylsulfoxide over a wide concentration range

    International Nuclear Information System (INIS)

    Safonova, L.P.; Shmukler, L.Eh.; Kolker, A.M.

    2008-01-01

    The integral heats of solution of Bu 4 NI in dimethylsulfoxide (DMSO) were measured at 298.15, 313.15, and 328.15 K and concentrations from dilute to saturation. The standard enthalpies and heat capacities of solution and solvation of Bu 4 NI in DMSO at various temperatures and the C-bar p 0 (Bu 4 N + ) value at 298.15 K were calculated. The obtained and literature data were used to consider the influence of the nature of solvents on Δ sol H m (Bu 4 NI) and of the electrolyte on Δ sol H m in dimethylsulfoxide at 298.15 K. The dynamic viscosity and density of the Bu 4 NI-DMSO system were determined at various concentrations and temperatures. The Eyring equation was used to calculate the activation energy of viscous flow at all the concentrations studied [ru

  13. The thermodynamic characteristics of solutions of Bu4NI in dimethylsulfoxide over a wide concentration range

    Science.gov (United States)

    Safonova, L. P.; Shmukler, L. E.; Kolker, A. M.

    2008-05-01

    The integral heats of solution of Bu4NI in dimethylsulfoxide (DMSO) were measured at 298.15, 313.15, and 328.15 K and concentrations from dilute to saturation. The standard enthalpies and heat capacities of solution and solvation of Bu4NI in DMSO at various temperatures and the bar C_p^o (Bu_4 N^ + ) value at 298.15 K were calculated. The obtained and literature data were used to consider the influence of the nature of solvents on Δsol H m (Bu4NI) and of the electrolyte on Δsol H m in dimethylsulfoxide at 298.15 K. The dynamic viscosity and density of the Bu4NI-DMSO system were determined at various concentrations and temperatures. The Eyring equation was used to calculate the activation energy of viscous flow at all the concentrations studied.

  14. Effect of ion concentrations on uranium absorption from sodium carbonate solutions

    International Nuclear Information System (INIS)

    Traut, D.E.; El Hazek, N.M.T.; Palmer, G.R.; Nichols, I.L.

    1979-01-01

    The effect of various ion concentrations on uranium absorption from a sodium carbonate solution by a strong-base, anion resin was investigated in order to help assure an adequate uranium supply for future needs. The studies were conducted to improve the recovery of uranium from in situ leach solutions by ion exchange. The effects of carbonate, bicarbonate, chloride, and sulfate ions were examined. Relatively low (less than 5 g/l) concentrations of chloride, sulfate, and bicarbonate were found to be detrimental to the absorption of uranium. High (greater than 10 g/l) carbonate concentrations also adversely affected the uranium absorption. In addition, the effect of initial resin form was investigated in tests of the chloride, carbonate, and bicarbonate forms; resin form was shown to have no effect on the absorption of uranium

  15. assessment of concentration of air pollutants using analytical and numerical solution of the atmospheric diffusion equation

    International Nuclear Information System (INIS)

    Esmail, S.F.H.

    2011-01-01

    The mathematical formulation of numerous physical problems a results in differential equations actually partial or ordinary differential equations.In our study we are interested in solutions of partial differential equations.The aim of this work is to calculate the concentrations of the pollution, by solving the atmospheric diffusion equation(ADE) using different mathematical methods of solution. It is difficult to solve the general form of ADE analytically, so we use some assumptions to get its solution.The solutions of it depend on the eddy diffusivity profiles(k) and the wind speed u. We use some physical assumptions to simplify its formula and solve it. In the present work, we solve the ADE analytically in three dimensions using Green's function method, Laplace transform method, normal mode method and these separation of variables method. Also, we use ADM as a numerical method. Finally, comparisons are made with the results predicted by the previous methods and the observed data.

  16. Increase The Sugar Concentration of The Solution Sugar by Reverse Osmotic Membrane

    Science.gov (United States)

    Redjeki, S.; Hapsari, N.; Iriani

    2018-01-01

    Sugar is one of the basic needs of people and food and drink industry. As technology advances and the demand for efficient usage of sugar rises, crystal sugar is seen as less advantageous than liquid sugar. If sugar is always dissolved in water before use, then it will be more efficient and practical for consumers to use sugar in liquid form than in crystal form. Other than that, liquid sugar is also attractive to consumers because it is economical, hygienic, instantly soluble in hot and cold water, fresher and longer-lasting, able to thicken and enrich the texture of foods and drinks, and functions as sweetener, syrup, and flavor enhancer. Liquid sugar is also more beneficial for sugar producers because of simpler production process, cheaper production cost, and similar yield with no extra cost. In sugar production, separation process is found in most of its stages and therefore the use of membrane technology for separating solute and water content has a good potential. In this research, water content reduction of sugar solution was done in order to increase the sugar concentration of the solution. The parameters of this research were 4%, 5%, and 6% starting concentration of sugar solution; 20, 40, and 60 minutes of process time; and 85 and 60 PSI ΔP. The best result was acquired on 4% starting concentration, 60 PSI ΔP, and 60 minutes process time.

  17. Effects of potential and concentration of bicarbonate solution on stress corrosion cracking of annealed carbon steel

    International Nuclear Information System (INIS)

    Haruna, Takumi; Zhu, Liehong; Murakami, Makoto; Shibata, Toshio

    2000-01-01

    Effects of potential and concentration of bicarbonate on stress corrosion cracking (SCC) of annealed SM 400 B carbon steel has been investigated in bicarbonate solutions at 343 K. The surface of annealed specimen had decarburized layer of about 0. 5 mm thickness. A potentiostatic slow strain rate testing apparatus equipped with a charge coupled device camera system was employed to evaluate SCC susceptibility from the viewpoint of the crack behavior. In a constant bicarbonate concentration of 1 M, cracks were observed in the potential range from -800 to 600 mV Ag/ A gCl . and especially, the initiation and the propagation of the cracks were accelerated at -600 mV. At a constant potential of -600 mV, cracks were observed in the concentration range from 0.001 to 1 M, and the initiation and the propagation of the cracks were suppressed as the concentration decreased. Polarization curves for the decarburized surface were measured with two different scan rates. High SCC susceptibility may be expected in the potential range where the difference between the two current densities is large. It was found in this system that the potential with the maximum difference in the current density was -600 mV for 1 M bicarbonate solution, and the potential increased with a decrease in the concentration of bicarbonate. This means that an applied potential of -600 mV provides the highest SCC susceptibility for 1 M bicarbonate solution, and that the SCC susceptibility decreases as the concentration decreases. These findings support the dependence of the actual SCC behavior on the potential and the concentration of bicarbonate. (author)

  18. Toward new instruments for measurement of low concentration hydrogen sulfide in small-quantity aqueous solutions

    International Nuclear Information System (INIS)

    Wu, Xiao Chu; Wu, Dong Qing; Zhang, W J; Sammynaiken, R; Yang, Wei; Wang, Rui

    2008-01-01

    Endogenously generated hydrogen sulfide (H 2 S) has been found to play some important physiological roles in the nervous and cardiovascular systems, such as a neuromodulator and a vasorelaxant. These roles are in contrast to our common perception that H 2 S is toxic. However, whether H 2 S plays a positive or negative role is dependent on the H 2 S concentration levels in mammals. This further puts a high demand on the accurate measurement of H 2 S in mammals with a further desire to be real time, continuous and in vivo. Existing methods for H 2 S measurement require a large number of tissue samples with complex procedures, and these methods are extremely invasive. The development of new in vivo and real-time methods for measuring H 2 S is, however, a great challenge. In the present study, we proposed and examined five potential H 2 S measurement methods: (1) atomic force microscopy with coating materials, (2) Raman spectroscopy on the H 2 S solutions, (3) gas chromatography/mass spectroscopy (with the static headspace technique) on the H 2 S solutions, (4) mass spectroscopy on unfunctionalized carbon nanotubes treated with the H 2 S solutions and (5) Raman spectroscopy on unfunctionalized carbon nanotubes treated with the H 2 S solutions. Our study concluded that method (5) is the most promising one for detecting low concentration H 2 S in small-quantity aqueous solutions in terms of measurement resolution and non-invasiveness, but the method is not very robust

  19. Solute concentration affects bradykinin-mediated increases in renal prostaglandin E2

    International Nuclear Information System (INIS)

    Zenser, T.V.; Davis, E.S.; Rapp, N.S.; Davis, B.B.

    1981-01-01

    The effects of solute concentration on the bradykinin-mediated increase in inner medullary slice prostaglandin E2 (PGE2) synthesis were investigated. PG content was determined by specific RIA. Bradykinin stimulation was prevented by the addition of the following solutes to Krebs buffer: 1.0 M urea, 0.5 or 1.0 M NaCl, 0.5 or 1.0 M mannitol, 1.0 M urea plus 0.5 M NaCl, or 1.0 M mannitol plus 0.5 M NaCl. By contrast, basal PGE2 synthesis was increased by 1.0 M mannitol or by 1.0 M mannitol plus 0.5 M NaCl, but decreased by 1.0 M urea. Urea elicited a concentration-dependent, reversible inhibition of bradykinin stimulation, with 0.01 M urea being the lowest effective concentration. By contrast, basal PGE2 synthesis was only reduced at a urea concentration greater than 0.6 M. Arachidonic acid-mediated increases in both PGE2 and PGF2 alpha synthesis were not prevented by 1.0 M urea. The latter suggests that neither PG endoperoxide synthetase nor PG endoperoxide E isomerase are inhibited by urea. The data indicate that different hypertonic solutions have different effects on basal PG production, but all inhibit bradykinin stimulation

  20. Formation and stabilization of anionic metal complexes in concentrated aqueous quaternary ammonium salt solutions

    International Nuclear Information System (INIS)

    Aronson, F.L.; Hwang, L.L.Y.; Ronca, N.; Solomon, N.A.; Steigman, J.

    1985-01-01

    Anionic complexes of transition metals were stabilized in aqueous solutions containing high concentrations of various short-chain quaternary ammonium salts. Compounds with longer paraffin chains were effective in much less concentrated solution. Complex ions were detected spectrophotometrically. FeCl 4 - , which is usually formed in concentrated HCl, was the predominant Fe(III) complex in 30 m choline chloride containing only 0.12 M HCl. A yellow transitory Tc(VII) chloro-addition intermediate, formed in the reduction of TcO 4 - by concentrated HCl, was stabilized when the solution also contained 25 m choline chloride. Its spectrum, as well as the isolation of an already known Tc(VII) bipyridyl complex, is reported. Concentrated organic electrolytes also stabilized Tc(V) oxide halides against disproportionation and Tc(IV) hexahalides against hydrolysis. Halochromates of Cr(VI) were formed and stabilized in dilute acid containing quaternary ammonium salts. Their UV spectra showed the well-resolved vibronic fine structure associated with the symmetric chromium-to-oxygen charge-transfer band. It is known that these progressions are resolved in aprotic solvents, but not in aqueous acidic solution alone, and that the loss of fine structure in aqueous media is due to hydrogen bonding. The stabilization of anionic metal complexes and the resolution of vibronic structure in halochromates are probably consequences of water-structure-enforced ion paring. The present work suggests that the water molecules in immediate contact with the complex anions are more strongly hydrogen bonded to each other than to the complex. 21 references, 4 figures

  1. Scintillation detector with anticoincidence shield for determination of the radioactive concentration of standard solutions

    International Nuclear Information System (INIS)

    Broda, R.; Radoszewski, T.

    1982-01-01

    The construction and parameters of the prototype liquid scintillation detector for disintegration rate determination of standard solutions is described. The detector is equipped with a liquid scintillation anticoincidence shield with a volume of 40 l. The instrument is placed in the building of the Radioisotope Production and Distribution Centre in the Institute of Nuclear Research at Swierk. The results of instrument background reduction are described. The counting efficiency of several beta-emitters 3 H, 63 Ni, 14 C and 90 Sr + 90 Y is given, as well as the examples of a disintegration rate determination of low radioactivity concentration of standard solutions. (author)

  2. The prediction of concentration profiles for a NIMCIX column absorbing uranium from aqueous solution

    International Nuclear Information System (INIS)

    Wright, R.S.

    1979-01-01

    A procedure is proposed for the prediction of concentration profiles for a countercurrent ion-exchange absorption column, use being made of equilibrium and kinetic data derived from small-scale batch tests. A comparison is presented between the predictions and the measured performance of a column (2,5 m in diameter) absorbing uranium from solution. The method is shown to be adequate for design purposes provided that the data used are from tests in which the solution and resin conditions approximate those for which the plant is being designed [af

  3. Oxidative Pressure Leaching of Silver from Flotation Concentrates with Ammonium Thiocyanate Solution

    Science.gov (United States)

    Yang, Sheng-Hai; Yang, Jian-Guang; Liu, Wei; Chen, Geng-Tao; Tang, Mo-Tang; Qiu, Guan-Zhou

    2010-02-01

    The thermodynamics and technologies of the selective pressure leaching of silver from flotation concentrates were investigated in an ammonium thiocyanate medium. Thermodynamic analyses, which include silver solubility in NH4SCN solution and Eh-pH diagrams of the Me-MeS-NH4SCN-H2O system at 25 °C, were discussed. The effects of several factors, such as temperature, leaching time, oxidant, pH value, flotation concentrates concentration, surfactant concentration, and so on, on the extraction percentages of silver and zinc were investigated. The following optimal leaching conditions were obtained: NH4SCN concentration 1.5 M, lignin concentration 0.5 g/L, Fe3+ concentration 2 g/L, flotation concentrates addition 200 g/L, and oxygen pressure 1.2 MPa at 130 °C for 3 hours. Under these optimum conditions, the average extraction percentage of silver exceeded 94 pct, whereas the average extraction percentage of zinc was less than 3 pct. Only 7 pct of ammonium thiocyanate was consumed after 4 cycles, which indicated that ammonium thiocyanate hardly was oxidized under these oxidative pressure leaching conditions.

  4. Unusual concentration-dependent microscopic dynamics of dendrimers in aqueous solution

    International Nuclear Information System (INIS)

    Wong, Kaikin; Wu, Chin Ming; Lam, Hak Fai; Chathoth, Suresh M.

    2016-01-01

    Dendrimers are novel three-dimensional, hyperbranched globular nanopolymeric macromolecules. The nanoscopic size, narrow polydispersity index, excellent control over molecular structure, availability of multiple functional groups at the periphery, and cavities in the interior made them very attractive candidate for drug delivery. In this communication, we have studied the microscopic dynamics of tetra-acid and pentaerythritol glycidyl ether dendrimers dissolved in aqueous solution with different concentrations. The effects of concentration and temperature to their long-range diffusion process are investigated by dynamic light scattering. Experimental results show a huge variation in the translational diffusion coefficient for the two dendrimers samples. Besides, the dependence of diffusion coefficients on concentration is unusually different in these dendrimer samples. Although the diffusion process follows Arrhenius relation with the temperature in both systems, the activation energy for the diffusion process has a distinct concentration dependence.

  5. Unusual concentration-dependent microscopic dynamics of dendrimers in aqueous solution

    Science.gov (United States)

    Wong, Kaikin; Wu, Chin Ming; Lam, Hak Fai; Chathoth, Suresh M.

    2016-05-01

    Dendrimers are novel three-dimensional, hyperbranched globular nanopolymeric macromolecules. The nanoscopic size, narrow polydispersity index, excellent control over molecular structure, availability of multiple functional groups at the periphery, and cavities in the interior made them very attractive candidate for drug delivery. In this communication, we have studied the microscopic dynamics of tetra-acid and pentaerythritol glycidyl ether dendrimers dissolved in aqueous solution with different concentrations. The effects of concentration and temperature to their long-range diffusion process are investigated by dynamic light scattering. Experimental results show a huge variation in the translational diffusion coefficient for the two dendrimers samples. Besides, the dependence of diffusion coefficients on concentration is unusually different in these dendrimer samples. Although the diffusion process follows Arrhenius relation with the temperature in both systems, the activation energy for the diffusion process has a distinct concentration dependence.

  6. Unusual concentration-dependent microscopic dynamics of dendrimers in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Kaikin; Wu, Chin Ming; Lam, Hak Fai; Chathoth, Suresh M., E-mail: smavilac@cityu.edu.hk [City University of Hong Kong, Department of Physics and Materials Science (Hong Kong, People’s Republic of China) (China)

    2016-05-15

    Dendrimers are novel three-dimensional, hyperbranched globular nanopolymeric macromolecules. The nanoscopic size, narrow polydispersity index, excellent control over molecular structure, availability of multiple functional groups at the periphery, and cavities in the interior made them very attractive candidate for drug delivery. In this communication, we have studied the microscopic dynamics of tetra-acid and pentaerythritol glycidyl ether dendrimers dissolved in aqueous solution with different concentrations. The effects of concentration and temperature to their long-range diffusion process are investigated by dynamic light scattering. Experimental results show a huge variation in the translational diffusion coefficient for the two dendrimers samples. Besides, the dependence of diffusion coefficients on concentration is unusually different in these dendrimer samples. Although the diffusion process follows Arrhenius relation with the temperature in both systems, the activation energy for the diffusion process has a distinct concentration dependence.

  7. Direct Analysis of Proteins from Solutions with High Salt Concentration Using Laser Electrospray Mass Spectrometry

    Science.gov (United States)

    Karki, Santosh; Shi, Fengjian; Archer, Jieutonne J.; Sistani, Habiballah; Levis, Robert J.

    2018-05-01

    The detection of lysozyme, or a mixture of lysozyme, cytochrome c, and myoglobin, from solutions with varying salt concentrations (0.1 to 250 mM NaCl) is compared using laser electrospray mass spectrometry (LEMS) and electrospray ionization-mass spectrometry (ESI-MS). Protonated protein peaks were observed up to a concentration of 250 mM NaCl in the case of LEMS. In the case of ESI-MS, a protein solution with salt concentration > 0.5 mM resulted in predominantly salt-adducted features, with suppression of the protonated protein ions. The constituents in the mixture of proteins were assignable up to 250 mM NaCl for LEMS and were not assignable above a NaCl concentration of 0.5 mM for ESI. The average sodium adducts () bound to the 7+ charge state of lysozyme for LEMS measurements from salt concentrations of 2.5, 25, 50, and 100 mM NaCl are 1.71, 5.23, 5.26, and 5.11, respectively. The conventional electrospray measurements for lysozyme solution containing salt concentrations of 0.1, 1, 2, and 5 mM NaCl resulted in of 2.65, 6.44, 7.57, and 8.48, respectively. LEMS displays an approximately two orders of magnitude higher salt tolerance in comparison with conventional ESI-MS. The non-equilibrium partitioning of proteins on the surface of the charged droplets is proposed as the mechanism for the high salt tolerance phenomena observed in the LEMS measurements. [Figure not available: see fulltext.

  8. Relating soil solution Zn concentration to diffusive gradients in thin films measurements in contaminated soils.

    Science.gov (United States)

    Degryse, Fien; Smolders, Erik; Oliver, Ian; Zhang, Hao

    2003-09-01

    The technique of diffusive gradients in thin films (DGT) has been suggested to sample an available fraction of metals in soil. The objectives of this study were to compare DGT measurements with commonly measured fractions of Zn in soil, viz, the soil solution concentration and the total Zn concentration. The DGT technique was used to measure fluxes and interfacial concentrations of Zn in three series of field-contaminated soils collected in transects toward galvanized electricity pylons and in 15 soils amended with ZnCl2 at six rates. The ratio of DGT-measured concentration to pore water concentration of Zn, R, varied between 0.02 and 1.52 (mean 0.29). This ratio decreased with decreasing distribution coefficient, Kd, of Zn in the soil, which is in agreement with the predictions of the DGT-induced fluxes in soils (DIFS) model. The R values predicted with the DIFS model were generally larger than the observed values in the ZnCl2-amended soils at the higher Zn rates. A modification of the DIFS model indicated that saturation of the resin gel was approached in these soils, despite the short deployment times used (2 h). The saturation of the resin with Zn did not occur in the control soils (no Zn salt added) or the field-contaminated soils. Pore water concentration of Zn in these soils was predicted from the DGT-measured concentration and the total Zn content. Predicted values and observations were generally in good agreement. The pore water concentration was more than 5 times underpredicted for the most acid soil (pH = 3) and for six other soils, for which the underprediction was attributed to the presence of colloidal Zn in the soil solution.

  9. Effects of over-winter green cover on soil solution nitrate concentrations beneath tillage land.

    Science.gov (United States)

    Premrov, Alina; Coxon, Catherine E; Hackett, Richard; Kirwan, Laura; Richards, Karl G

    2014-02-01

    There is a growing need to reduce nitrogen losses from agricultural systems to increase food production while reducing negative environmental impacts. The efficacy of vegetation cover for reducing nitrate leaching in tillage systems during fallow periods has been widely investigated. Nitrate leaching reductions by natural regeneration (i.e. growth of weeds and crop volunteers) have been investigated to a lesser extent than reductions by planted cover crops. This study compares the efficacy of natural regeneration and a sown cover crop (mustard) relative to no vegetative cover under both a reduced tillage system and conventional plough-based system as potential mitigation measures for reducing over-winter soil solution nitrate concentrations. The study was conducted over three winter fallow seasons on well drained soil, highly susceptible to leaching, under temperate maritime climatic conditions. Mustard cover crop under both reduced tillage and conventional ploughing was observed to be an effective measure for significantly reducing nitrate concentrations. Natural regeneration under reduced tillage was found to significantly reduce the soil solution nitrate concentrations. This was not the case for the natural regeneration under conventional ploughing. The improved efficacy of natural regeneration under reduced tillage could be a consequence of potential stimulation of seedling germination by the autumn reduced tillage practices and improved over-winter plant growth. There was no significant effect of tillage practices on nitrate concentrations. This study shows that over winter covers of mustard and natural regeneration, under reduced tillage, are effective measures for reducing nitrate concentrations in free draining temperate soils. © 2013.

  10. Plant-Scale Concentration Column Designs for SHINE Target Solution Utilizing AG 1 Anion Exchange Resin

    Energy Technology Data Exchange (ETDEWEB)

    Stepinski, Dominique C. [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, G. F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-30

    Argonne is assisting SHINE Medical Technologies (SHINE) in their efforts to develop SHINE, an accelerator-driven process that will utilize a uranyl-sulfate solution for the production of fission product Mo-99. An integral part of the process is the development of a column for the separation and recovery of Mo-99, followed by a concentration column to reduce the product volume from 15-25 L to <1 L. Argonne has collected data from batch studies and breakthrough column experiments to utilize the VERSE (Versatile Reaction Separation) simulation program (Purdue University) to design plant-scale product recovery and concentration processes.

  11. Specific wavelength colorimeter. [for measuring given solute concentration in test sample

    Science.gov (United States)

    Brawner, C. C.; Mcdavid, L. S.; Walsh, J. M. (Inventor)

    1974-01-01

    A self contained, specific wavelength, single beam colorimeter is described for direct spectrophotometric measurement of the concentration of a given solute in a test sample. An electrical circuit employing a photoconductive cell converts the optical output into a linear, directly readable meter output. The colorimeter is simple to operate and is adapted for use in zero gravity conditions. In a specific application, the colorimeter is designed to analyze the concentration of iodine in potable water carried aboard a space vehicle such as the 4B stage of Skylab.

  12. Influence of chemical disorder on energy dissipation and defect evolution in concentrated solid solution alloys

    International Nuclear Information System (INIS)

    Zhang, Yanwen; Wang, Lumin; Caro, Alfredo; Weber, William J.; Univ. of Tennessee, Knoxville, TN

    2015-01-01

    A long-standing objective in materials research is to understand how energy is dissipated in both the electronic and atomic subsystems in irradiated materials, and how related non-equilibrium processes may affect defect dynamics and microstructure evolution. Here we show that alloy complexity in concentrated solid solution alloys having both an increasing number of principal elements and altered concentrations of specific elements can lead to substantial reduction in the electron mean free path and thermal conductivity, which has a significant impact on energy dissipation and consequentially on defect evolution during ion irradiation. Enhanced radiation resistance with increasing complexity from pure nickel to binary and to more complex quaternary solid solutions is observed under ion irradiation up to an average damage level of 1 displacement per atom. Understanding how materials properties can be tailored by alloy complexity and their influence on defect dynamics may pave the way for new principles for the design of radiation tolerant structural alloys

  13. Green synthesis of highly concentrated aqueous colloidal solutions of large starch-stabilised silver nanoplatelets.

    Science.gov (United States)

    Cheng, Fei; Betts, Jonathan W; Kelly, Stephen M; Hector, Andrew L

    2015-01-01

    A simple, environmentally friendly and cost-effective method has been developed to prepare a range of aqueous silver colloidal solutions, using ascorbic acid as a reducing agent, water-soluble starch as a combined crystallising, stabilising and solubilising agent, and water as the solvent. The diameter of silver nanoplatelets increases with higher concentrations of AgNO3 and starch. The silver nanoparticles are also more uniform in shape the greater the diameter of the nanoparticles. Colloidal solutions with a very high concentration of large, flat, hexagonal silver nanoplatelets (~230 nm in breadth) have been used to deposit and fix an antibacterial coating of these large starch-stabilised silver nanoplates on commercial cotton fibres, using a simple dip-coating process using water as the solvent, in order to study the dependence of the antibacterial properties of these nanoplatelets on their size. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Molecular Effects of Concentrated Solutes on Protein Hydration, Dynamics, and Electrostatics.

    Science.gov (United States)

    Abriata, Luciano A; Spiga, Enrico; Peraro, Matteo Dal

    2016-08-23

    Most studies of protein structure and function are performed in dilute conditions, but proteins typically experience high solute concentrations in their physiological scenarios and biotechnological applications. High solute concentrations have well-known effects on coarse protein traits like stability, diffusion, and shape, but likely also perturb other traits through finer effects pertinent at the residue and atomic levels. Here, NMR and molecular dynamics investigations on ubiquitin disclose variable interactions with concentrated solutes that lead to localized perturbations of the protein's surface, hydration, electrostatics, and dynamics, all dependent on solute size and chemical properties. Most strikingly, small polar uncharged molecules are sticky on the protein surface, whereas charged small molecules are not, but the latter still perturb the internal protein electrostatics as they diffuse nearby. Meanwhile, interactions with macromolecular crowders are favored mainly through hydrophobic, but not through polar, surface patches. All the tested small solutes strongly slow down water exchange at the protein surface, whereas macromolecular crowders do not exert such strong perturbation. Finally, molecular dynamics simulations predict that unspecific interactions slow down microsecond- to millisecond-timescale protein dynamics despite having only mild effects on pico- to nanosecond fluctuations as corroborated by NMR. We discuss our results in the light of recent advances in understanding proteins inside living cells, focusing on the physical chemistry of quinary structure and cellular organization, and we reinforce the idea that proteins should be studied in native-like media to achieve a faithful description of their function. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  15. Recrystallization of freezable bound water in aqueous solutions of medium concentrations

    Institute of Scientific and Technical Information of China (English)

    赵立山; 潘礼庆; 纪爱玲; 曹则贤; 王强

    2016-01-01

    For aqueous solutions with freezable bound water, vitrification and recrystallization are mingled, which brings diffi-culty to application and misleads the interpretation of relevant experiments. Here, we report a quantification scheme for the freezable bound water based on the water-content dependence of glass transition temperature, by which also the concentra-tion range for the solutions that may undergo recrystallization finds a clear definition. Furthermore, we find that depending on the amount of the freezable bound water, different temperature protocols should be devised to achieve a complete recrys-tallization. Our results may be helpful for understanding the dynamics of supercooled aqueous solutions and for improving their manipulation in various industries.

  16. Thermosolutal convection in saturated porous enclosure with concentrated energy and solute sources

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Di; Zhao, Fu-Yun; Tang, Guang-Fa [College of Civil Engineering, Hunan University, Changsha (China)

    2008-01-15

    Double diffusive natural convection within a vertical porous enclosure with localized heating and salting from one side is numerically studied by the finite element based finite volume method. In the formulation of the problem, use is made of the Darcy model, which allows the slip boundary condition on a solid wall to be satisfied. Comparisons with benchmark solutions for natural convection in fluid saturated porous enclosures are first presented to validate the code. Following that, an extensive series of numerical simulations is conducted in the range of -55 {<=} N {<=} + 55 and 0.125 {<=} L {<=} 0.875, where N and L are the buoyancy ratio and the element location, respectively. Streamlines, heatlines, masslines, isotherms and iso-concentrations in the system are produced to illustrate the flow structure transition from solutal dominated opposing to thermal dominated and solutal dominated aiding flows, respectively. The computed average Nusselt and Sherwood numbers provide guidance for locating the heating and salting element. (author)

  17. Thermosolutal convection in saturated porous enclosure with concentrated energy and solute sources

    Energy Technology Data Exchange (ETDEWEB)

    Liu Di [College of Civil Engineering, Hunan University, Changsha (China)], E-mail: liudi66@163.com; Zhao Fuyun [College of Civil Engineering, Hunan University, Changsha (China)], E-mail: zfycfdnet@163.com; Tang Guangfa [College of Civil Engineering, Hunan University, Changsha (China)], E-mail: gftangcfd@163.com

    2008-01-15

    Double diffusive natural convection within a vertical porous enclosure with localized heating and salting from one side is numerically studied by the finite element based finite volume method. In the formulation of the problem, use is made of the Darcy model, which allows the slip boundary condition on a solid wall to be satisfied. Comparisons with benchmark solutions for natural convection in fluid saturated porous enclosures are first presented to validate the code. Following that, an extensive series of numerical simulations is conducted in the range of -55 {<=} N {<=} + 55 and 0.125 {<=} L {<=} 0.875, where N and L are the buoyancy ratio and the element location, respectively. Streamlines, heatlines, masslines, isotherms and iso-concentrations in the system are produced to illustrate the flow structure transition from solutal dominated opposing to thermal dominated and solutal dominated aiding flows, respectively. The computed average Nusselt and Sherwood numbers provide guidance for locating the heating and salting element.

  18. Behaviour of solute and particle markers in the stomach of sheep given a concentrate diet

    International Nuclear Information System (INIS)

    Faichney, G.J.; Griffiths, D.A.

    1978-01-01

    Fistulated sheep given a concentrate diet were used to study the behaviour of solute ([ 51 Cr]EDTA) and particle ([ 103 Ru]phenanthroline) markers in the stomach under conditions of continuous feeding. An injection of a mixed dose of [ 51 Cr]EDTA and [ 103 Ru]phenanthroline was given into the rumen and the time course of marker concentrations in the rumen and the abomasum was recorded. The curves were analysed on the assumption that the stomach of the sheep could be represented as two mixing compartments (reticulo-rumen and abomasum) and a time delay (omasum). This model provided a very good description of the data. [ 103 Ru]-phenanthroline associated with small particles was retained in the rumen much longer than [ 51 Cr]EDTA. Although exchange of [ 103 Ru] phenanthroline occurred between large and small particle fractions, the results suggested that small particles may have been retained somewhat longer in the rumen than solutes. However, it was clear from the results that the mean retention times for particulate matter in the rumen could not be simply obtained using adsorbable markers. Cyclical fluctuations in the concentration of [ 51 Cr]EDTA in the rumen indicated that there were daily variations in net water flux in the rumen. The presence of protozoa was associated with much shorter retention times of both solutes and particles in the rumen. Protozoa were also associated with reduced rumen volumes. (author)

  19. Metrological assessment of TDR performance for measurement of potassium concentration in soil solution

    Directory of Open Access Journals (Sweden)

    Isaac de M. Ponciano

    2016-04-01

    Full Text Available ABSTRACT Despite the growing use of the time domain reflectometry (TDR technique to monitoring ions in the soil solution, there are few studies that provide insight into measurement error. To overcome this lack of information, a methodology, based on the central limit theorem error, was used to quantify the uncertainty associated with using the technique to estimate potassium ion concentration in two soil types. Mathematical models based on electrical conductivity and soil moisture derived from TDR readings were used to estimate potassium concentration, and the results were compared to potassium concentration determined by flame spectrophotometry. It was possible to correct for random and systematic errors associated with TDR readings, significantly increasing the accuracy of the potassium estimation methodology. However, a single TDR reading can lead to an error of up to ± 18.84 mg L-1 K+ in soil solution (0 to 3 dS m-1, with a 95.42% degree of confidence, for a loamy sand soil; and an error of up to ± 12.50 mg L-1 of K+ (0 to 2.5 dS m-1 in soil solution, with a 95.06% degree of confidence, for a sandy clay soil.

  20. Effect of solute atom concentration on vacancy cluster formation in neutron-irradiated Ni alloys

    Science.gov (United States)

    Sato, Koichi; Itoh, Daiki; Yoshiie, Toshimasa; Xu, Qiu; Taniguchi, Akihiro; Toyama, Takeshi

    2011-10-01

    The dependence of microstructural evolution on solute atom concentration in Ni alloys was investigated by positron annihilation lifetime measurements. The positron annihilation lifetimes in pure Ni, Ni-0.05 at.%Si, Ni-0.05 at.%Sn, Ni-Cu, and Ni-Ge alloys were about 400 ps even at a low irradiation dose of 3 × 10 -4 dpa, indicating the presence of microvoids in these alloys. The size of vacancy clusters in Ni-Si and Ni-Sn alloys decreased with an increase in the solute atom concentration at irradiation doses less than 0.1 dpa; vacancy clusters started to grow at an irradiation dose of about 0.1 dpa. In Ni-2 at.%Si, irradiation-induced segregation was detected by positron annihilation coincidence Doppler broadening measurements. This segregation suppressed one-dimensional (1-D) motion of the interstitial clusters and promoted mutual annihilation of point defects. The frequency and mean free path of the 1-D motion depended on the solute atom concentration and the amount of segregation.

  1. Solution Behavior and Activity of a Halophilic Esterase under High Salt Concentration

    Science.gov (United States)

    Rao, Lang; Zhao, Xiubo; Pan, Fang; Li, Yin; Xue, Yanfen; Ma, Yanhe; Lu, Jian R.

    2009-01-01

    Background Halophiles are extremophiles that thrive in environments with very high concentrations of salt. Although the salt reliance and physiology of these extremophiles have been widely investigated, the molecular working mechanisms of their enzymes under salty conditions have been little explored. Methodology/Principal Findings A halophilic esterolytic enzyme LipC derived from archeaon Haloarcula marismortui was overexpressed from Escherichia coli BL21. The purified enzyme showed a range of hydrolytic activity towards the substrates of p-nitrophenyl esters with different alkyl chains (n = 2−16), with the highest activity being observed for p-nitrophenyl acetate, consistent with the basic character of an esterase. The optimal esterase activities were found to be at pH 9.5 and [NaCl] = 3.4 M or [KCl] = 3.0 M and at around 45°C. Interestingly, the hydrolysis activity showed a clear reversibility against changes in salt concentration. At the ambient temperature of 22°C, enzyme systems working under the optimal salt concentrations were very stable against time. Increase in temperature increased the activity but reduced its stability. Circular dichroism (CD), dynamic light scattering (DLS) and small angle neutron scattering (SANS) were deployed to determine the physical states of LipC in solution. As the salt concentration increased, DLS revealed substantial increase in aggregate sizes, but CD measurements revealed the maximal retention of the α-helical structure at the salt concentration matching the optimal activity. These observations were supported by SANS analysis that revealed the highest proportion of unimers and dimers around the optimal salt concentration, although the coexistent larger aggregates showed a trend of increasing size with salt concentration, consistent with the DLS data. Conclusions/Significance The solution α-helical structure and activity relation also matched the highest proportion of enzyme unimers and dimers. Given that

  2. Structure and interaction of silk fibroin and graphene oxide in concentrated solution under shear.

    Science.gov (United States)

    Zhang, Chao; Shao, Huili; Luo, Jie; Hu, Xuechao; Zhang, Yaopeng

    2018-02-01

    Considering the high biocompatibility of regenerated silk fibroin (RSF) and the good enhancement effect of graphene oxide (GO), various RSF/GO composite materials have been previously investigated, and found that GO plays a vital role in the fabrication of high-performance RSF/GO materials. However, its effects on the structure of RSF solution are unclear. Therefore, in this work, we studied the rheological and optical properties, as well as the aggregation behavior of concentrated RSF/GO solution in response to applied shear. The results demonstrated that the presence of GO sheets in RSF solution increased the shear resistance, while delayed the sol-gel transition. Moreover, GO sheets were not favorable to the formation of the ordered structures of RSF. The results from small angle X-ray scattering (SAXS) of RSF/GO solution also showed that the shear process promoted the formation of RSF/GO interface. The data also provided insights into the structural evolution within the mixture solutions, which can be beneficial to the future design and fabrication of nanofiller-reinforced high-performance materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Effects of four additive solutions on canine leukoreduced red cell concentrate quality during storage.

    Science.gov (United States)

    Lacerda, Luciana A; Hlavac, Nicole R C; Terra, Silvia R; Back, Franciele P; Jane Wardrop, K; González, Félix H D

    2014-09-01

    Additive solutions (AS) and prestorage leukoreduction (LR) are important tools used to maintain erythrocyte viability during storage and avoid transfusion reactions in recipients, respectively. The purpose of the study was to determine the efficacy of a WBC filter (Immugard IIIRC) and compare the effect of 4 AS (phosphate-adenine-glucose-guanosine-gluconate-mannitol [PAGGGM], saline-adenine-glucose-mannitol [SAGM], Adsol, Optisol) on the in vitro quality of canine leukoreduced packed RBC units (pRBC) stored for 41 days. Five hundred milliliters of blood were collected from 8 healthy dogs each into 70 mL of citrate-phosphate-dextrose (CPD) solution, and were leukoreduced by a polyurethane filter. pRBC of each dog were divided equally into 4 bags containing a different AS. Bags were stored for 41 days at 4°C and evaluated every 10 days. Variables analyzed included pH, PCV, and% hemolysis, and lactate, glucose, potassium, sodium, ATP, and 2,3-diphosphoglycerate (2,3-DPG) concentrations. The LR resulted in residual WBC counts comparable to human standards. During storage, pH, and glucose, 2,3-DPG, and ATP concentrations decreased, and hemolysis, and lactate, sodium, and potassium concentrations increased (P 2,3-DPG concentrations. When compared with day 1 values, significant changes were seen in these variables by day 31 with all AS. © 2014 American Society for Veterinary Clinical Pathology and European Society for Veterinary Clinical Pathology.

  4. Physico-chemical stability of eribulin mesylate containing concentrate and ready-to-administer solutions.

    Science.gov (United States)

    Spindeldreier, Kirsten; Thiesen, Judith; Lipp, Hans-Peter; Krämer, Irene

    2014-06-01

    The aim of this study was to determine the stability of commercially available eribulin mesylate containing injection solution as well as diluted ready-to-administer solutions stored under refrigeration or at room temperature. Stability was studied by a novel developed stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) assay with ultraviolet detection (detection wavelength 200 nm). Triplicate test solutions of eribulin mesylate containing injection concentrate (0.5 mg/mL) and with 0.9% sodium chloride solution diluted ready-to-administer preparations (0.205 mg/mL eribulin mesylate in polypropylene (PP) syringes, 0.020 mg/mL eribulin mesylate in polypropylene/polyethylene (PE) bags) were stored protected from light either at room temperature (25) or under refrigeration (2-8). Samples were withdrawn on day 0 (initial), 1, 3, 5, 7, 14, 21 and 28 of storage and assayed. Physical stability was determined by measuring the pH value once a week and checking for visible precipitations or colour changes. The stability tests revealed that concentrations of eribulin mesylate remained unchanged over a period of 28 days irrespective of concentration, container material or storage temperature. Neither colour changes nor visible particles have been observed. The pH value varied slightly over time but remained in the stability favourable range of 5-9. Eribulin mesylate injection (0.5 mg/mL) is physico-chemically stable over a period of 28 days after first puncture of the vial. After dilution with 0.9% NaCl vehicle solution, ready-to-administer eribulin mesylate injection solutions (0.205 mg/mL in PP syringe) and infusion solutions (0.02 mg/mL in prefilled PP/PE bags) are physico-chemically stable for a period of at least four weeks either refrigerated or stored at room temperature. For microbiological reasons storage under refrigeration is recommended.

  5. K-edge x-ray fluorescence analysis for actinide and heavy elements solution concentration measurements

    International Nuclear Information System (INIS)

    Camp, D.C.

    1984-07-01

    Advantages of using Co-57 as an exciter for K XRFA include: a compact design that requires no x-ray tubes; the exciter-detector assembly locates remote from support electronics; on-line, at-line, or off-line configurations for monitor/measurements; systems that can be run by semi-skilled technicians, once programmed; and operated via remote terminals with results sent to control rooms; heavy element concentrations that are measurable thru industrial pipes; independent of minor changes in solution matrix or source half life with concentration results reported in near-real-time; a dynamic range of measurable concentrations that is greater than 10 4 ; measurement times that are reasonable even at 1 gram/liter; and for nuclear safeguards, it provides the <0.5% accuracy required by DOE for the accountability of U, Pu, or both, once the system is calibrated

  6. Magnetic resonance butterfly coils: Design and application for hyperpolarized 13C studies

    DEFF Research Database (Denmark)

    Giovannetti, Giulio; Frijia, Francesca; Attanasio, Simona

    2013-01-01

    Hyperpolarized 13C magnetic resonance spectroscopy in pig models enables cardiac metabolism assessment and provides a powerful tool for heart physiology studies, although the low molar concentration of derivate metabolites gives rise to technological limitations in terms of data quality. The desi...... throughout the volume of interest for cardiac imaging in pig. Experimental SNR-vs-depth profiles, extracted from the [1-13C]acetate phantom chemical shift image (CSI), permitted to highlight the performance of the proposed coils configuration. © 2013 Elsevier Ltd. All rights reserved....

  7. Hyperpolarized singlet NMR on a small animal imaging system

    DEFF Research Database (Denmark)

    Laustsen, Christoffer; Pileio, Giuseppe; Tayler, Michael C. D.

    2012-01-01

    Nuclear spin hyperpolarization makes a significant advance toward overcoming the sensitivity limitations of in vivo magnetic resonance imaging, particularly in the case of low-gamma nuclei. The sensitivity may be improved further by storing the hyperpolarization in slowly relaxing singlet...... populations of spin- 1/2 pairs. Here, we report hyperpolarized 13C spin order transferred into and retrieved from singlet spin order using a small animal magnetic resonance imaging scanner. For spins in sites with very similar chemical shifts, singlet spin order is sustained in high magnetic field without...... requiring strong radiofrequency irradiation. The demonstration of robust singlet-to-magnetization conversion, and vice versa, on a small animal scanner, is promising for future in vivo and clinical deployments....

  8. Solute concentration dependence of the decay curves of the liquid scintillation

    International Nuclear Information System (INIS)

    Onishi, Masayoshi; Niki, Eiji.

    1976-01-01

    The decay curves of the liquid scintillation of 2,5-diphenyloxazole (PPO) in toluene by the irradiation of β ray from 14 C were measured. Solute concentration dependences of the decay times of the fast and slow components were studied. The decay time tau sub(f) of the fast component of the air saturated scintillator was the smallest at 1.8x10 -2 --4.5x10 -2 mol/l, and about (3.4--3.5)ns. When the concentration became less than 1.8x10 -2 mol/l, the peak of the decay curve became roundish and the pulse width became large. The increase of the necessary time for the energy transfer due to the difficulty of the nonradiative transfer from excited solvent molecules to the solute was the reason. When the concentration became less than about 2.26x10 -3 mol/l, tau sub(f) became larger and the energy transfer became radiative. The pulse width and tau sub(f) were very small because of oxygen quenching compared with oxygen free. At higher concentrations such as 1.6x10 -1 and 2.3x10 -1 mol/l, the effect of the PPO excimer was observed on the fast component, and tau sub(f) became larger apparently. This denied the presumption of the close relation between PPO molecular interaction and the slow component together with the fact that the decay time tau sub(s) of the slow component was independent of PPO concentration. (auth.)

  9. Molecular studies of Cs adsorption sites in inorganic layered materials: the influence of solution concentration.

    Science.gov (United States)

    Sato, Kiminori; Hunger, Michael

    2017-07-19

    Radioactive Cs released into a soil environment migrates along with groundwater in a manner dependent on Cs concentration. Data on the variation of Cs adsorption as a function of solution concentration are an essential prerequisite to successful decontamination work in Fukushima. To aid the ongoing decontamination work, the adsorption of Cs in aqueous solution across a wide Cs + molarity range is studied for the case of saponite clay as adsorbent, an inorganic layered material that is an abundant mineral in the soil environment. The local molecular structures, i.e. nanosheet surfaces, nanosheet edges, and oncoming hexagonal cavities, participating in Cs adsorption are qualitatively highlighted by means of a recently developed analytical method using data from a conventional elution test, 133 Cs magic-angle-spinning nuclear magnetic resonance (MAS NMR), and the radiocesium interception potential (RIP) [K. Sato, et al., J. Phys. Chem. C, 2016, 120, 1270]. The concentrations of nanosheet edges amount to between 100 and 400 mmol kg -1 , which are not substantially different from those of the nanosheet surfaces, generally regarded as the main decontamination sites. This unambiguously implies that the nanosheet edges should be targeted as the molecular sites for decontaminating radioactive Cs, in addition to the nanosheet surfaces.

  10. Modification of a Turbulent Boundary Layer within a Homogeneous Concentration of Drag reducing Polymer Solution

    Science.gov (United States)

    Farsiani, Yasaman; Elbing, Brian

    2017-11-01

    High molecular weight polymer solutions in wall-bounded flows can reduce the local skin friction by as much as 80%. External flow studies have typical focused on injection of polymer within a developing turbulent boundary layer (TBL), allowing the concentration and drag reduction level to evolve with downstream distance. Modification of the log-law region of the TBL is directly related to drag reduction, but recent results suggest that the exact behavior is dependent on flow and polymer properties. Weissenberg number and the viscosity ratio (ratio of solvent viscosity to the zero-shear viscosity) are concentration dependent, thus the current study uses a polymer ocean (i.e. a homogenous concentration of polymer solution) with a developing TBL to eliminate uncertainty related to polymer properties. The near-wall modified TBL velocity profiles are acquired with particle image velocimetry. In the current presentation the mean velocity profiles and the corresponding flow (Reynolds number) and polymer (Weissenberg number, viscosity ratio, and length ratio) properties are reported. Note that the impact of polymer degradation on molecular weight will also be quantified and accounted for when estimating polymer properties This work was supported by NSF Grant 1604978.

  11. Study on the spectrum of photonic crystal cavity and its application in measuring the concentration of NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yun [Nanjing Agricultural Univ., Nanjing (China). Dept. of Physics; Wuxi Institute of Commerce, Wuxi (China). School of Electromechanical Technology; Xie, Xun; Hao, Jiong-Ju; Yang, Hong-Wei [Nanjing Agricultural Univ., Nanjing (China). Dept. of Physics; Yang, Ze-Kun [Lanzhou Univ. (China). School of Information Science and Engineering; Xu, Zhi-Gang [Nanjing Agricultural Univ., Nanjing (China). College of Agriculture

    2017-07-01

    In this article, we propose an approach to measure solution concentrations by using photonic crystal cavities. Based on the experimental data, the refractive index of a NaCl solution is proportional to the concentration. Filling the proposed photonic crystal cavity with a NaCl solution, we calculate the spectral transmission using the transfer matrix method. We found that the cavity transmittance was proportional to the refractive index of the NaCl solution, and thus we obtained a linear relationship between cavity transmittance and the concentration of the NaCl solution. The formula was found by fitting the simulation results with experimental data. Such a formula can be applied to the measurement of an unknown concentration of NaCl solution utilizing a photonic crystal cavity.

  12. Effect of Concentration on the Interfacial and Bulk Structure of Ionic Liquids in Aqueous Solution.

    Science.gov (United States)

    Cheng, H-W; Weiss, H; Stock, P; Chen, Y-J; Reinecke, C R; Dienemann, J-N; Mezger, M; Valtiner, M

    2018-02-27

    Bio and aqueous applications of ionic liquids (IL) such as catalysis in micelles formed in aqueous IL solutions or extraction of chemicals from biologic materials rely on surface-active and self-assembly properties of ILs. Here, we discuss qualitative relations of the interfacial and bulk structuring of a water-soluble surface-active IL ([C 8 MIm][Cl]) on chemically controlled surfaces over a wide range of water concentrations using both force probe and X-ray scattering experiments. Our data indicate that IL structuring evolves from surfactant-like surface adsorption at low IL concentrations, to micellar bulk structure adsorption above the critical micelle concentration, to planar bilayer formation in ILs with Interfacial structuring is controlled by mesoscopic bulk structuring at high water concentrations. Surface chemistry and surface charges decisively steer interfacial ordering of ions if the water concentration is low and/or the surface charge is high. We also demonstrate that controlling the interfacial forces by using self-assembled monolayer chemistry allows tuning of interfacial structures. Both the ratio of the head group size to the hydrophobic tail volume as well as the surface charging trigger the bulk structure and offer a tool for predicting interfacial structures. Based on the applied techniques and analyses, a qualitative prediction of molecular layering of ILs in aqueous systems is possible.

  13. Preferential solvation, ion pairing, and dynamics of concentrated aqueous solutions of divalent metal nitrate salts

    Science.gov (United States)

    Yadav, Sushma; Chandra, Amalendu

    2017-12-01

    We have investigated the characteristics of preferential solvation of ions, structure of solvation shells, ion pairing, and dynamics of aqueous solutions of divalent alkaline-earth metal nitrate salts at varying concentration by means of molecular dynamics simulations. Hydration shell structures and the extent of preferential solvation of the metal and nitrate ions in the solutions are investigated through calculations of radial distribution functions, tetrahedral ordering, and also spatial distribution functions. The Mg2+ ions are found to form solvent separated ion-pairs while the Ca2+ and Sr2+ ions form contact ion pairs with the nitrate ions. These findings are further corroborated by excess coordination numbers calculated through Kirkwood-Buff G factors for different ion-ion and ion-water pairs. The ion-pairing propensity is found to be in the order of Mg(NO3) 2 lead to the presence of substantial dynamical heterogeneity in these solutions of strongly interacting ions. The current study helps us to understand the molecular details of hydration structure, ion pairing, and dynamics of water in the solvation shells and also of ion diffusion in aqueous solutions of divalent metal nitrate salts.

  14. Effect of solute concentration on grain boundary migration with segregation in stainless steel and model alloys

    Science.gov (United States)

    Kanda, H.; Hashimoto, N.; Takahashi, H.

    The phenomenon of grain boundary migration due to boundary diffusion via vacancies is a well-known process for recrystallization and grain growth during annealing. This phenomenon is known as diffusion-induced grain boundary migration (DIGM) and has been recognized in various binary systems. On the other hand, grain boundary migration often occurs under irradiation. Furthermore, such radiation-induced grain boundary migration (RIGM) gives rise to solute segregation. In order to investigate the RIGM mechanism and the interaction between solutes and point defects during the migration, stainless steel and Ni-Si model alloys were electron-irradiated using a HVEM. RIGM was often observed in stainless steels during irradiation. The migration rate of boundary varied, and three stages of the migration were recognized. At lower temperatures, incubation periods up to the occurrence of the boundary migration were observed prior to first stage. These behaviors were recognized particularly for lower solute containing alloys. From the relation between the migration rates at stage I and inverse temperatures, activation energies for the boundary migration were estimated. In comparison to the activation energy without irradiation, these values were very low. This suggests that the RIGM is caused by the flow of mixed-dumbbells toward the grain boundary. The interaction between solute and point defects and the effective defect concentration generating segregation will be discussed.

  15. Electrochemical behaviour of brass in chloride solution concentrations found in eccrine fingerprint sweat

    Energy Technology Data Exchange (ETDEWEB)

    Bond, John W., E-mail: jwb13@le.ac.uk [Department of Chemistry, George Porter Building, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Lieu, Elaine [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

    2014-09-15

    Highlights: • Corrosion of brass in NaCl concentrations found in eccrine sweat was investigated. • Concentrations < 0.2 M produce a layer of mainly zinc oxide after 24 h. • A concentration of 0.2 M enables active corrosion of brass at room temperature. • 0.2 M NaCl gives both zinc and copper dissolution. • 24-h immersion of brass in 0.2 M NaCl gives an oxide film thickness of 1.3 nm. - Abstract: In this work, the corrosion properties of α phase brass immersed in concentrations of aqueous NaCl solutions that are typically found in eccrine fingerprint sweat and range between 0.01 M and 0.2 M have been analysed. Analysis methods employed were electrochemical techniques, X-ray photoelectron spectroscopy and optical profiling. For NaCl concentrations <0.2 M, active corrosion did not occur although, after a period of 24 h, a passivating layer of mainly zinc oxide formed. At a concentration of 0.2 M active corrosion did occur, with measured corrosion potentials consistent with both brass and copper dissolution. A 1 h contact time at this concentration (0.2 M) resulted in the formation of a zinc oxide passivating layer with the surface ratio of zinc oxide to copper oxide increasing with time. Film thickness was calculated to be of the order of 1.3 nm after 24 h contact. Formation of oxide layers on brass by fingerprint sweat as observed here may well have implications for the successful investigation of crime by the visualisation of corrosion fingerprint ridge patterns or the reduction of hospital environmental contamination by hand contact with brass objects such as door handles or taps.

  16. Corrosion of dissimilar metal crevices in simulated concentrated ground water solutions at elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, B.M.; Quinn, M.J

    2003-01-01

    The disposal of high-level nuclear waste in the Yucca Mountain, Nevada is under consideration by the US Department of Energy. The proposed facility will be located in the unsaturated zone approximately 300 m below the surface and 300 m above the water table. The proposed waste container consists of an outer corrosion-resistant Alloy 22 shell surrounding a 316 NG stainless steel structural inner container that encapsulates the used nuclear fuel waste. A titanium drip shield is proposed to protect the waste container from ground water seepage arid rock-fail. A cycle of dripping/evaporation could result in the generation of concentrated aggressive solutions, which could contact the waste container. The waste container material could be susceptible to crevice corrosion from such solutions. The experiments described in this report support the modeling of waste package degradation processes. The intent was to provide parameter values that are required to model crevice corrosion chemistry, as it relates to hydrogen pick-up, and stress corrosion cracking for selected candidate waste package materials. The purpose of the experiments was to study the crevice corrosion behavior of various candidate materials under near freely corroding conditions and to determine the pH developed in crevice solutions. Experimental results of crevice corrosion of dissimilar metal pairs (Alloy 22, Grade-7 and -16 titanium and 316 stainless steel) immersed in a simulated concentrated ground water at {approx}90{sup o}C are reported. The corrosion potential was measured during exposure periods of between 330 and 630 h. Following the experiments, the pH of the crevice solution was measured. The results indicate that a limited degree of crevice acidification occurred during the experiment. The values for corrosion potential suggest that crevice corrosion may have initiated. The total corrosion was limited, with little visible evidence for crevice corrosion being observed on the sample coupon faces

  17. Corrosion of dissimilar metal crevices in simulated concentrated ground water solutions at elevated temperature

    International Nuclear Information System (INIS)

    Ikeda, B.M.; Quinn, M.J.

    2003-01-01

    The disposal of high-level nuclear waste in the Yucca Mountain, Nevada is under consideration by the US Department of Energy. The proposed facility will be located in the unsaturated zone approximately 300 m below the surface and 300 m above the water table. The proposed waste container consists of an outer corrosion-resistant Alloy 22 shell surrounding a 316 NG stainless steel structural inner container that encapsulates the used nuclear fuel waste. A titanium drip shield is proposed to protect the waste container from ground water seepage arid rock-fail. A cycle of dripping/evaporation could result in the generation of concentrated aggressive solutions, which could contact the waste container. The waste container material could be susceptible to crevice corrosion from such solutions. The experiments described in this report support the modeling of waste package degradation processes. The intent was to provide parameter values that are required to model crevice corrosion chemistry, as it relates to hydrogen pick-up, and stress corrosion cracking for selected candidate waste package materials. The purpose of the experiments was to study the crevice corrosion behavior of various candidate materials under near freely corroding conditions and to determine the pH developed in crevice solutions. Experimental results of crevice corrosion of dissimilar metal pairs (Alloy 22, Grade-7 and -16 titanium and 316 stainless steel) immersed in a simulated concentrated ground water at ∼90 o C are reported. The corrosion potential was measured during exposure periods of between 330 and 630 h. Following the experiments, the pH of the crevice solution was measured. The results indicate that a limited degree of crevice acidification occurred during the experiment. The values for corrosion potential suggest that crevice corrosion may have initiated. The total corrosion was limited, with little visible evidence for crevice corrosion being observed on the sample coupon faces. The

  18. Solution-processed organic thermoelectric materials exhibiting doping-concentration-dependent polarity.

    Science.gov (United States)

    Hwang, Sunbin; Potscavage, William J; Yang, Yu Seok; Park, In Seob; Matsushima, Toshinori; Adachi, Chihaya

    2016-10-26

    Recent progress in conducting polymer-based organic thermoelectric generators (OTEGs) has resulted in high performance due to high Seebeck coefficient, high electrical conductivity (σ), and low thermal conductivity obtained by chemically controlling the materials's redox levels. In addition to improving the properties of individual OTEGs to obtain high performance, the development of solution processes for the fabrication of OTEG modules is necessary to realize large thermoelectric voltage and low-cost mass production. However, the scarcity of good candidates for soluble organic n-type materials limits the use of π-leg module structures consisting of complementary elements of p- and n-type materials because of unbalanced transport coefficients that lead to power losses. In particular, the extremely low σ of n-type materials compared with that of p-type materials is a serious challenge. In this study, poly(pyridinium phenylene) (P(PymPh)) was tested as an n-type semiconductor in solution-processed OTEGs, and the carrier density was controlled by a solution-based chemical doping process using the dopant sodium naphthalenide, a well-known reductant. The electronic structures and doping mechanism of P(PymPh) were explored based on the changes in UV-Vis-IR absorption, ultraviolet photoelectron, and X-ray photoelectron spectra. By controlling the dopant concentration, we demonstrate a maximum n-type power factor of 0.81 μW m -1 K -2 with high σ, and at higher doping concentrations, a switch from n-type to p-type TE operation. This is one of the first cases of a switch in polarity just by increasing the concentration of the reductant and may open a new route for simplified fabrication of complementary organic layers.

  19. On the Usage of Cyclic Voltammetry and Impedance Spectroscopy for Measuring the Concentration of Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Manuel Fiedler

    2015-02-01

    Full Text Available This article describes sensors for concentration measurement based on the electro- chemical properties of the liquid being measured. Herein two electrical methods, namely cyclic voltammetry and impedance spectroscopy, are being presented. The measurement can be performed quasi simultaneously using the same measurement medium. Further optimization of the combined methods is possible by adapting the geometric design of the electrode structure, the electrode material, the optional passivation and the electric coupling (galvanically or capacitively. In summary, by combining multiple sensory principles on a device it becomes possible to analyze mixtures of substances contained in a solution with respect to their composition.

  20. Existence and concentration of positive solutions for a quasilinear elliptic equation in R

    Directory of Open Access Journals (Sweden)

    Elisandra Gloss

    2010-05-01

    Full Text Available We study the existence and concentration of positive solutions for the quasilinear elliptic equation $$ -varepsilon^2u'' -varepsilon^2(u^2''u+V(x u = h(u $$ in $mathbb{R}$ as $varepsilono 0$, where the potential $V:mathbb{R}o mathbb{R}$ has a positive infimum and $inf_{partial Omega}V>inf_{ Omega}V$ for some bounded domain $Omega$ in $mathbb{R}$, and $h$ is a nonlinearity without having growth conditions such as Ambrosetti-Rabinowitz.

  1. Structural study of concentrated micelle-solutions of sodium octanoate by light scattering

    International Nuclear Information System (INIS)

    Hayoun, Marc

    1982-05-01

    Structural investigation of sodium octanoate (CH 3 -(CH 2 ) 6 -COONa) by light scattering has been made to study properties of concentrated aqueous micelle-solutions. From static light scattering data, the micellar weight and shape have been determined. The monomer aggregation number and the apparent micellar charge have been confirmed. Quasi-elastic light scattering, has been used to measure the effective diffusion coefficient as a function of the volume fraction. Extrapolation to the c.m.c. give the hydrodynamic radius of the micelles. At low micelle-concentration, strong exchange reaction between monomers and micelles affects the Brownian motion and resulting is an increase in the diffusion coefficient. The experimental data show a strong hydrodynamic contribution to S(q) (factor structure) and D(q) (effective diffusion coefficient) arising from hard spheres interactions with a large repulsive potential. (author) [fr

  2. Chemical concentration of a new natural spontaneously fissionable nuclide from solutions with low salt background

    International Nuclear Information System (INIS)

    Korotkin, Yu.S.; Ter-Akop'yan, G.M.; Popeko, A.G.; Drobina, T.P.; Zhuravleva, E.L.

    1982-01-01

    The results of experiments on further concentration of a new natural spontaneously fissionable nuclide, the concentrates of which form the Cheleken geothermal brines have been obtained, are presented. The conclusions are drown about the chemical nature of a new spontaneously fissionable nuclide. It is a chalcophile element which copreipitates with sulphides of copper, lead, arsenic and mercury from weakly acid solutions. The behaviour of the new nuclide in sulphide systems in many respects is similar to the behaviour of polonium, astatine and probably of bismuth. The most probable stable valence of the new nuclide varies from +1 up to +3. The data available on the chemical behaviour of the new nuclide as well as the analysis over contamination by spontaneously fissionable isotopes permit to state that the new natural spontaneously fissionable nuclide does not relate to the known isotopes

  3. Effect of applied voltage and initial concentration to desalting NaCl solution using electrodialysis

    International Nuclear Information System (INIS)

    Boubakri, Ali; Gzara, Lassaad; Dhahbi, Mahmoud; Bouguecha, Salah

    2009-01-01

    The desalination process of electrodialysis is one of membrane separation that competes with reverse osmosis for desalination of brackish water and seawater. In this work water desalination using a laboratory electrodialysis was performed and evaluated to desalting aqueous solutions containing 5000, 10000 and 20000 mg/L NaCl at different applied potential (10, 15 and 20 V) and at a constant flow rate of 3 L/min. Nine electrodialysis runs were performed. The results showed that the increasing of applied potential and decreasing of NaCl concentration have an important effect to enhance the electrodialysis performance. The efficiencies of each experiment were evaluated as function of specific power consumption with the electrical energy consumed in electrodialysis stack. It was obtained that the specific power consumption increased when the salt concentration and applied voltage increased. A laboratory electrodialysis stack containing fifteen cation exchange membranes and fifteen anion exchange membranes of 0,716 m 2 total effective area was used.

  4. Determination of the thermodynamic state of concentrated hemoglobin solutions by means of small angle X-ray scattering

    International Nuclear Information System (INIS)

    Zinke, M.

    1979-01-01

    Exemplified by hemoglobin, the thermodynamic equilibrium properties of the dissolved macromolecular system could be determined solely from the small angle X-ray scattering of concentrated macromolecular solutions via the intermolecular structure of the dissolved macromolecules and their intermolecular potentials. From the scattering experiment on concentrated Hb solutions the concentration dependence of the following properties of the dissolved Hb system were determined: fluctuation, isothermic compressibility, internal energy, surface tension, and osmotic pressure. (author)

  5. Concentration of Rutin Model Solutions from Their Mixtures with Glucose Using Ultrafiltration

    Directory of Open Access Journals (Sweden)

    Zaid S. Saleh

    2010-02-01

    Full Text Available Separation of polyphenolic phytochemical compounds from their mixtures with sugars is necessary to produce an added-value sugar-reduced extract with high biological activity from fruit juice processing industry waste streams. The separation characteristics of a binary mixture of rutin and glucose using a Pellicon-2 regenerated cellulose ultrafiltration membrane with an area of 0.1 m2 having nominal MWCO of 1,000 Da were investigated, to demonstrate the separation of phenolic compounds from sugars. The effects of the operating variables–transmembrane pressure, feed solution temperature and pH, initial feed concentration and feed flow rate–on the permeate flux and enrichment of rutin, were determined. The permeate flux increased with the increase in transmembrane pressure up to a certain limit and after that the flux remained more or less constant. The optimum transmembrane pressure was within 4–5 bar. The flux increased with the increase in feed solution temperature because of reduced feed viscosity, and better solubility. The concentration of rutin was optimum at lower temperature (30ºC, with an enrichment factor of 1.3. The effect of pH on permeate flux was less obvious. Lowering the feed solution pH increased the retention of rutin and the optimum separation was obtained within pH 3–4. The permeate flux decreased with the increase in feed concentration of rutin (concentration range 0.1–0.5 g/L. The enrichment of rutin was significant in the glucose concentration range 0.35–0.5 g/L. The feed flow rate had a significant effect on the flux and separation characteristics. Higher cross-flow through the membrane reduced the fouling by providing a shear force to sweep away deposited materials from the membrane surface. At high feed flow rate, more rutin was retained by the membrane with less sugar permeating through. The optimum feed flow rate was 1.5 L/min. For the separation of rutin (in the retentate and glucose (in the permeate, the

  6. Concentration dependence of solute atoms on vacancy cluster formation in neutron irradiated Ni alloy

    International Nuclear Information System (INIS)

    Sato, K.; Itoh, D.; Yoshiie, T.; Xu, Q.

    2007-01-01

    Full text of publication follows: One dimensional (1-D) motion of interstitial clusters is important for the microstructural evolution in metals. The movement of interstitial clusters was often observed in neutron irradiated metals by transmission electron microscopy (TEM). Alloying elements are expected to affect the motion of interstitial clusters. Yoshiie et al. have studied the effect of alloying elements in Ni. For example, in neutron irradiated pure Ni, well-developed dislocation networks and voids were observed at 573 K at a dose of 0.026 dpa by TEM. After the addition of 2at.%Si (-5.81% volume size factor to Ni) and Sn (74.08% volume size factor), no voids were detected by TEM observation and positron lifetime measurement. Alloying elements of Si and Sn were expected to prevent the 1-D motion of the interstitial clusters. In this study, the concentration dependence of alloying elements on the 1-D motion of the interstitial clusters was investigated by positron annihilation lifetime measurements, and the microstructural evolution was discussed. Specimens irradiated were 99.99 pure Ni (Johnson Matthey) and Ni based binary alloys, which contain Si, Cu, Ge and Sn as solute atoms. The concentration of solute atoms was 0.05at.%o, 0.3at.% and 2at.%. Neutron irradiation was performed with the Kyoto University Reactor (KUR) and Japan materials testing reactor (JMTR) at Japan Atomic Energy Agency. Neutron dose was 6x10 -5 -1x10 -2 dpa at KUR, and 8x10 -3 -0.3 dpa at JMTR. Irradiation temperature was 573 K at KUR and 563 K at JMTR. After the neutron irradiation, positron annihilation lifetime measurements were performed at room temperature. Microvoids were detected in pure Ni, Ni-0.05%Si, Ni-0.05%Sn, Ni-Cu and Ni-Ge alloys. In Ni-Si and Ni-Sn alloys, the size of microvoids decreased as the concentration of solute atoms increased. This is because the frequency of 1-D motion of the interstitial clusters depends on the alloy concentration. High concentration of alloying

  7. Concentration dependence of solute atoms on vacancy cluster formation in neutron irradiated Ni alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sato, K.; Itoh, D.; Yoshiie, T.; Xu, Q. [Kyoto Univ., Research Reactor Institute, Osaka (Japan)

    2007-07-01

    Full text of publication follows: One dimensional (1-D) motion of interstitial clusters is important for the microstructural evolution in metals. The movement of interstitial clusters was often observed in neutron irradiated metals by transmission electron microscopy (TEM). Alloying elements are expected to affect the motion of interstitial clusters. Yoshiie et al. have studied the effect of alloying elements in Ni. For example, in neutron irradiated pure Ni, well-developed dislocation networks and voids were observed at 573 K at a dose of 0.026 dpa by TEM. After the addition of 2at.%Si (-5.81% volume size factor to Ni) and Sn (74.08% volume size factor), no voids were detected by TEM observation and positron lifetime measurement. Alloying elements of Si and Sn were expected to prevent the 1-D motion of the interstitial clusters. In this study, the concentration dependence of alloying elements on the 1-D motion of the interstitial clusters was investigated by positron annihilation lifetime measurements, and the microstructural evolution was discussed. Specimens irradiated were 99.99 pure Ni (Johnson Matthey) and Ni based binary alloys, which contain Si, Cu, Ge and Sn as solute atoms. The concentration of solute atoms was 0.05at.%o, 0.3at.% and 2at.%. Neutron irradiation was performed with the Kyoto University Reactor (KUR) and Japan materials testing reactor (JMTR) at Japan Atomic Energy Agency. Neutron dose was 6x10{sup -5}-1x10{sup -2} dpa at KUR, and 8x10{sup -3} -0.3 dpa at JMTR. Irradiation temperature was 573 K at KUR and 563 K at JMTR. After the neutron irradiation, positron annihilation lifetime measurements were performed at room temperature. Microvoids were detected in pure Ni, Ni-0.05%Si, Ni-0.05%Sn, Ni-Cu and Ni-Ge alloys. In Ni-Si and Ni-Sn alloys, the size of microvoids decreased as the concentration of solute atoms increased. This is because the frequency of 1-D motion of the interstitial clusters depends on the alloy concentration. High

  8. Effect of Concentration on the Electrochemistry and Speciation of the Magnesium Aluminum Chloride Complex Electrolyte Solution.

    Science.gov (United States)

    See, Kimberly A; Liu, Yao-Min; Ha, Yeyoung; Barile, Christopher J; Gewirth, Andrew A

    2017-10-18

    Magnesium batteries offer an opportunity to use naturally abundant Mg and achieve large volumetric capacities reaching over four times that of conventional Li-based intercalation anodes. High volumetric capacity is enabled by the use of a Mg metal anode in which charge is stored via electrodeposition and stripping processes, however, electrolytes that support efficient Mg electrodeposition and stripping are few and are often prepared from highly reactive compounds. One interesting electrolyte solution that supports Mg deposition and stripping without the use of highly reactive reagents is the magnesium aluminum chloride complex (MACC) electrolyte. The MACC exhibits high Coulombic efficiencies and low deposition overpotentials following an electrolytic conditioning protocol that stabilizes species necessary for such behavior. Here, we discuss the effect of the MgCl 2 and AlCl 3 concentrations on the deposition overpotential, current density, and the conditioning process. Higher concentrations of MACC exhibit enhanced Mg electrodeposition current density and much faster conditioning. An increase in the salt concentrations causes a shift in the complex equilibria involving both cations. The conditioning process is strongly dependent on the concentration suggesting that the electrolyte is activated through a change in speciation of electrolyte complexes and is not simply due to the annihilation of electrolyte impurities. Additionally, the presence of the [Mg 2 (μ-Cl) 3 ·6THF] + in the electrolyte solution is again confirmed through careful analysis of experimental Raman spectra coupled with simulation and direct observation of the complex in sonic spray ionization mass spectrometry. Importantly, we suggest that the ∼210 cm -1 mode commonly observed in the Raman spectra of many Mg electrolytes is indicative of the C 3v symmetric [Mg 2 (μ-Cl) 3 ·6THF] + . The 210 cm -1 mode is present in many electrolytes containing MgCl 2 , so its assignment is of broad interest

  9. A simple model for predicting solute concentration in agricultural tile lines shortly after application

    Directory of Open Access Journals (Sweden)

    T. S. Steenhuis

    1997-01-01

    Full Text Available Agricultural tile drainage lines have been implicated as a source of pesticide contamination of surface waters. Field experiments were conducted and a simple model was developed to examine preferential transport of applied chemicals to agricultural tile lines. The conceptual model consists of two linear reservoirs, one near the soil surface and one near the tile drain. The connection between the two reservoirs is via preferential flow paths with very little interaction with the soil matrix. The model assumes that only part of the field contributes solutes to the tile drain. The model was evaluated with data from the field experiments in which chloride, 2,4-D, and atrazine concentrations were measured on eight tile-drained plots that were irrigated twice. Atrazine was applied two months prior to the experiment, 2,4-D was sprayed just before the first irrigation, and chloride before the second irrigation. All three chemicals were found in the tile effluent shortly after the rainfall began. Generally, the concentration increased with increased flow rates and decreased exponentially after the rainfall ceased. Although the simple model could simulate the observed chloride concentration patterns in the tile outflow for six of the eight plots, strict validation was not possible because of the difficulty with independent measurement of the data needed for a preferential flow model applied to field conditions. The results show that, to simulate pesticide concentration in tile lines, methods that can measure field averaged preferential flow characteristics need to be developed.

  10. Biodesulfurization of vanadium-bearing titanomagnetite concentrates and pH control of bioleaching solution

    Science.gov (United States)

    Liu, Xiao-rong; Jiang, Sheng-cai; Liu, Yan-jun; Li, Hui; Wang, Hua-jun

    2013-10-01

    Vanadium-bearing titanomagnetite concentrates were desulfurized with Acidithiobacillus ferrooxidans ( A. ferrooxidans). The sulfur content of the concentrates was reduced from 0.69wt% to 0.14wt% after bioleaching for 15 d with a 10% pulp density at 30°C. Maintaining a stable pH value during biodesulfurization was critical because of high acid consumption, resulting from a combination of nonoxidative and oxidative dissolution of pyrrhotite in acid solution. It is discovered that the citric acid-disodium hydrogen phosphate buffer of pH 2.0 can control the solution pH value smoothly in the optimal range of 2.0-3.0 for A. ferrooxidans growth. Using the buffer in the volume fraction range of 5.0%-15.0% stimulates A. ferrooxidans growth and improves the biodesulfurization efficiency. Compared with the buffer-free control case, the maximum increase of biodesulfurization rate is 29.7% using a 10.0vol% buffer. Bioleaching provides an alternative process for desulfurization of vanadium-bearing titanomagnetite ores.

  11. Effects of nanoparticle heating on the structure of a concentrated aqueous salt solution

    Science.gov (United States)

    Sindt, Julien O.; Alexander, Andrew J.; Camp, Philip J.

    2017-12-01

    The effects of a rapidly heated nanoparticle on the structure of a concentrated aqueous salt solution are studied using molecular dynamics simulations. A diamond-like nanoparticle of radius 20 Å is immersed in a sodium-chloride solution at 20% above the experimental saturation concentration and equilibrated at T = 293 K and P = 1 atm. The nanoparticle is then rapidly heated to several thousand degrees Kelvin, and the system is held under isobaric-isoenthalpic conditions. It is observed that after 2-3 ns, the salt ions are depleted far more than water molecules from a proximal zone 15-25 Å from the nanoparticle surface. This leads to a transient reduction in molality in the proximal zone and an increase in ion clustering in the distal zone. At longer times, ions begin to diffuse back into the proximal zone. It is speculated that the formation of proximal and distal zones, and the increase in ion clustering, plays a role in the mechanism of nonphotochemical laser-induced nucleation.

  12. Effects of nanoparticle heating on the structure of a concentrated aqueous salt solution.

    Science.gov (United States)

    Sindt, Julien O; Alexander, Andrew J; Camp, Philip J

    2017-12-07

    The effects of a rapidly heated nanoparticle on the structure of a concentrated aqueous salt solution are studied using molecular dynamics simulations. A diamond-like nanoparticle of radius 20 Å is immersed in a sodium-chloride solution at 20% above the experimental saturation concentration and equilibrated at T = 293 K and P = 1 atm. The nanoparticle is then rapidly heated to several thousand degrees Kelvin, and the system is held under isobaric-isoenthalpic conditions. It is observed that after 2-3 ns, the salt ions are depleted far more than water molecules from a proximal zone 15-25 Å from the nanoparticle surface. This leads to a transient reduction in molality in the proximal zone and an increase in ion clustering in the distal zone. At longer times, ions begin to diffuse back into the proximal zone. It is speculated that the formation of proximal and distal zones, and the increase in ion clustering, plays a role in the mechanism of nonphotochemical laser-induced nucleation.

  13. Temperature and concentration calibration of aqueous polyvinylpyrrolidone (PVP solutions for isotropic diffusion MRI phantoms.

    Directory of Open Access Journals (Sweden)

    Friedrich Wagner

    Full Text Available To use the "apparent diffusion coefficient" (Dapp as a quantitative imaging parameter, well-suited test fluids are essential. In this study, the previously proposed aqueous solutions of polyvinylpyrrolidone (PVP were examined and temperature calibrations were obtained. For example, at a temperature of 20°C, Dapp ranged from 1.594 (95% CI: 1.593, 1.595 μm2/ms to 0.3326 (95% CI: 0. 3304, 0.3348 μm2/ms for PVP-concentrations ranging from 10% (w/w to 50% (w/w using K30 polymer lengths. The temperature dependence of Dapp was found to be so strong that a negligence seems not advisable. The temperature dependence is descriptively modelled by an exponential function exp(c2 (T - 20°C and the determined c2 values are reported, which can be used for temperature calibration. For example, we find the value 0.02952 K-1 for 30% (w/w PVP-concentration and K30 polymer length. In general, aqueous PVP solutions were found to be suitable to produce easily applicable and reliable Dapp-phantoms.

  14. Hyperpolarized 13C MR Markers of Renal Tumor Aggressiveness

    Science.gov (United States)

    2015-12-01

    production in the presence of oxygen (11, 12). Increased glycolysis facilitates the uptake and incorporation of nutrients and biomass needed for cell... shell coil; (d) Hyperpolarized lactate images overlaid on T2 weighted anatomical images, clearly depicting the tumor voxels (Figure 5). As shown in

  15. Hyperpolarized C-13 MRS Cardiac Metabolism Studies in Pigs

    DEFF Research Database (Denmark)

    Giovannetti, G.; Hartwig, V.; Frijia, F.

    2012-01-01

    Cardiac metabolism assessment with hyperpolarized 13C magnetic resonance spectroscopy in pig models requires the design of dedicated coils capable of providing large field of view with high signal-to-noise ratio (SNR) data. This work presents a comparison between a commercial 13C quadrature...

  16. Fluconazole treatment hyperpolarizes the plasma membrane of Candida cells

    Czech Academy of Sciences Publication Activity Database

    Elicharová, Hana; Sychrová, Hana

    2013-01-01

    Roč. 51, č. 8 (2013), s. 785-798 ISSN 1369-3786 R&D Projects: GA ČR GAP302/12/1151 Institutional research plan: CEZ:AV0Z50110509 Institutional support: RVO:67985823 Keywords : drug resistance * fluconazol * yeast * hyperpolarization Subject RIV: EE - Microbiology, Virology Impact factor: 2.261, year: 2013

  17. Hyperpolarized 2-oxoglutarate as metabolic agent in mr

    DEFF Research Database (Denmark)

    2015-01-01

    Hyperpolarized 1-13C-2-oxoglutarate as contrast agent in13C Magnetic Resonance diagnostic technique (13C-MRI) for use in the diagnosis of cancer. In particular, upon administration of said 1-13C-2-oxoglutarate, signals of 1-13C-glutamate are detected. More in particular, different MR signals from13...

  18. Assessment of colour changes during storage of elderberry juice concentrate solutions using the optimization method.

    Science.gov (United States)

    Walkowiak-Tomczak, Dorota; Czapski, Janusz; Młynarczyk, Karolina

    2016-01-01

    Elderberries are a source of dietary supplements and bioactive compounds, such as anthocyanins. These dyes are used in food technology. The aim of the study was to assess the changes in colour parameters, anthocyanin contents and sensory attributes in solutions of elderberry juice concentrates during storage in a model system and to determine predictability of sensory attributes of colour in solutions based on regression equations using the response surface methodology. The experiment was carried out according to the 3-level factorial design for three factors. Independent variables included pH, storage time and temperature. Dependent variables were assumed to be the components and colour parameters in the CIE L*a*b* system, pigment contents and sensory attributes. Changes in colour components X, Y, Z and colour parameters L*, a*, b*, C* and h* were most dependent on pH values. Colour lightness L* and tone h* increased with an increase in experimental factors, while the share of the red colour a* and colour saturation C* decreased. The greatest effect on the anthocyanin concentration was recorded for storage time. Sensory attributes deteriorated during storage. The highest correlation coefficients were found between the value of colour tone h* and anthocyanin contents in relation to the assessment of the naturalness and desirability of colour. A high goodness-of-fit of the model to data and high values of R2 for regression equations were obtained for all responses. The response surface method facilitates optimization of experimental factor values in order to obtain a specific attribute of the product, but not in all cases of the experiment. Within the tested range of factors, it is possible to predict changes in anthocyanin content and the sensory attributes of elderberry juice concentrate solutions as food dye, on the basis of the lack of a fit test. The highest stability of dyes and colour of elderberry solutions was found in the samples at pH 3.0, which confirms

  19. Simultaneous determination of nitric acid and uranium concentrations in aqueous solution from measurements of electrical conductivity, density, and temperature

    International Nuclear Information System (INIS)

    Spencer, B.B.

    1991-01-01

    Nuclear fuel reprocessing plants handle aqueous solutions of nitric acid and uranium in large quantities. Automatic control of process operations requires reliable measurements of these solutes concentration, but this is difficult to directly measure. Physical properties such as solution density and electrical conductivity vary with solute concentration and temperature. Conductivity, density and temperature can be measured accurately with relatively simple and inexpensive devices. These properties can be used to determine solute concentrations will good correlations. This paper provides the appropriate correlations for solutions containing 2 to 6 Molar (M) nitric acid and 0 to 300 g/L uranium metal at temperatures from 25--90 degrees C. The equations are most accurate below 5 M nitric acid, due to a broad maximum in the conductivity curve at 6 M. 12 refs., 9 figs., 6 tabs

  20. Hydraulic conductivity in response to exchangeable sodium percentage and solution salt concentration

    Directory of Open Access Journals (Sweden)

    Jefferson Luiz de Aguiar Paes

    2014-10-01

    Full Text Available Hydraulic conductivity is determined in laboratory assays to estimate the flow of water in saturated soils. However, the results of this analysis, when using distilled or deionized water, may not correspond to field conditions in soils with high concentrations of soluble salts. This study therefore set out to determine the hydraulic conductivity in laboratory conditions using solutions of different electrical conductivities in six soils representative of the State of Pernambuco, with the exchangeable sodium percentage adjusted in the range of 5-30%. The results showed an increase in hydraulic conductivity with both decreasing exchangeable sodium percentage and increasing electrical conductivity in the solution. The response to the treatments was more pronounced in soils with higher proportion of more active clays. Determination of hydraulic conductivity in laboratory is routinely performed with deionized or distilled water. However, in salt affected soils, these determinations should be carried out using solutions of electrical conductivity different from 0 dS m-1, with values close to those determined in the saturation extracts.

  1. Method development for the enantiomeric purity determination of low concentrations of adrenaline in local anaesthetic solutions by capillary electrophoresis

    NARCIS (Netherlands)

    Sänger-Van De Griend, Cari E.; Ek, Anders G.; Widahl-Näsman, Monica E.; Andersson, E. K Margareta

    2006-01-01

    L-Adrenaline is often included in local anaesthetic (LA) solutions for injection to improve the quality of the anaesthetic block. The concentration of the LA is between 2.5 and 20 mg/ml and the concentration of adrenaline is typically ≤0.1% of the LA concentration. In order to follow the

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

    Science.gov (United States)

    Dodrill, Michael W; Fedan, Jeffrey S

    2010-10-01

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

  3. STUDY OF CHEMICAL INTERACTION OF MAGNESIA CEMENT WITH HIGH CONCENTRATION MAGNESIUM CHLORIDE SOLUTIONS

    Directory of Open Access Journals (Sweden)

    DEREVIANKO V. N.

    2015-10-01

    Full Text Available Problem statement. In activating MgO by electrolyte salts, as a result of formation of non water-resist magnesium silicate hydrate are obtained the durable cement stone having the low water-resist. I. P. Vyrodov considers [9; 5], that magnesia cement curing in mixing with sufficiently concentrated (C > 20 % solutions MgCl2 is caused with the crystallization of oxyhydrochloride composition: 3MgO∙MgCl2∙11Н2О, 5MgO∙MgCl2∙13Н2О and 7MgO∙MgCl2∙15Н2О. In the lower concentration parts of MgCl2 solution is formed a transitional compound of Mg[(OHnCl2-n] with isomorphous Mg(OH2 structure. At very low Cl concentration only Mg(OH2 is practically formed. Purpose. The Formation of water-resist magnesium silicate hydrates for obtaining of fast curing and solid structure of the magnesia stone. Conclusion. The dependence of the formation of the magnesia stone from the ratio (MgO/MgCl2 of the magnesia cement (MgO and the magnesium chloride solution (MgCl2 of different density has been identified in order to obtain the best content for oxyhydrochloride 3MgO•MgCl2•11Н2О, 5MgO•MgCl2•13Н2О and magnesium hydroxide (Mg(OH2. In putting into the system MgO∙–∙H2О of the silicic acid or fine ground quartz grains with size of less than 20 – 30 microns, over 1 month for the magnesium silicate hydrates formation is needed, where from 2 to 5 % of the total number of newgrowths are created. The study is proved by the expert opinion, that magnesium silicate hydrates do not have binding properties, unlike calcium silicate hydrates, and the main role in the system curing is played with the Mg(OH2 gel recrystallization, which provides the acceptable stone strength (R ≈ 30MPa in a few years. It has been also established, that in mixing of cement with low concentration MgO solutions of less than 1,5 mol/l (or 13% 1,1g/sm3, the final product in the stone structure is Mg(OH2. With increasing the sealer (MgCl2 solution there is formed by turn in

  4. Concentration Dependences of the Surface Tension and Density of Solutions of Acetone-Ethanol-Water Systems at 293 K

    Science.gov (United States)

    Dadashev, R. Kh.; Dzhambulatov, R. S.; Mezhidov, V. Kh.; Elimkhanov, D. Z.

    2018-05-01

    Concentration dependences of the surface tension and density of solutions of three-component acetone-ethanol-water systems and the bounding binary systems at 273 K are studied. The molar volume, adsorption, and composition of surface layers are calculated. Experimental data and calculations show that three-component solutions are close to ideal ones. The surface tensions of these solutions are calculated using semi-empirical and theoretical equations. Theoretical equations qualitatively convey the concentration dependence of surface tension. A semi-empirical method based on the Köhler equation allows us to predict the concentration dependence of surface tension within the experimental error.

  5. Aggregation in concentrated protein solutions: Insights from rheology, neutron scattering and molecular simulations

    Science.gov (United States)

    Castellanos, Maria Monica

    Aggregation of therapeutic proteins is currently one of the major challenges in the bio-pharmaceutical industry, because aggregates could induce immunogenic responses and compromise the quality of the product. Current scientific efforts, both in industry and academia, are focused on developing rational approaches to screen different drug candidates and predict their stability under different conditions. Moreover, aggregation is promoted in highly concentrated protein solutions, which are typically required for subcutaneous injection. In order to gain further understanding about the mechanisms that lead to aggregation, an approach that combined rheology, neutron scattering, and molecular simulations was undertaken. Two model systems were studied in this work: Bovine Serum Albumin in surfactant-free Phosphate Buffered Saline at pH = 7.4 at concentrations from 11 mg/mL up to ˜519 mg/mL, and a monoclonal antibody in 20 mM Histidine/Histidine Hydrochloride at pH = 6.0 with 60 mg/mL trehalose and 0.2 mg/mL polysorbate-80 at concentrations from 53 mg/mL up to ˜220 mg/mL. The antibody used here has three mutations in the CH2 domain, which result in lower stability upon incubation at 40 °C with respect to the wild-type protein, based on size-exclusion chromatography assays. This temperature is below 49 °C, where unfolding of the least stable, CH2 domain occurs, according to differential scanning calorimetry. This dissertation focuses on identifying the role of aggregation on the viscosity of protein solutions. The protein solutions of this work show an increase in the low shear viscosity in the absence of surfactants, because proteins adsorb at the air/water interface forming a viscoelastic film that affects the measured rheology. Stable surfactant-laden protein solutions behave as simple Newtonian fluids. However, the surfactant-laden antibody solution also shows an increase in the low shear viscosity from bulk aggregation, after prolonged incubation at 40 °C. Small

  6. Attractive interactions between reverse aggregates and phase separation in concentrated malonamide extractant solutions

    International Nuclear Information System (INIS)

    Erlinger, C.; Belloni, L.; Zemb, T.; Madic, C.

    1999-01-01

    Using small angle X-ray scattering, conductivity, and phase behavior determination, the authors show that concentrated solutions of malonamide extractants, dimethyldibutyltetradecylmalonamide (DMDBTDMA), are organized in reverse oligomeric aggregates which have many features in common with reverse micelles. The aggregation numbers of these reverse globular aggregates as well as their interaction potential are determined from absolute scattering curves. An attractive interaction is responsible for the demixing of the oil phase when in equilibrium with excess oil. Prediction of conductivity as well as the formation conditions for the third phase is possible using standard liquid theory applied to the extractant aggregates. The interactions, modeled with the sticky sphere model proposed by Baster, are shown to be due to steric interactions resulting from the hydrophobic tails of the extractant molecule and van der Waals forces between the highly polarizable water core of the reverse micelles. The attractive interaction in the oil phase, equilibrated with water, is determined as a function of temperature, extractant molecule concentration, and proton and neodynium(III) cation concentration. It is shown that van der Waals interactions, with an effective Hamaker constant of 3kT, quantitatively explain the behavior of DMDBTDMA in n-dodecane in terms of scattering as well as phase stability limits

  7. Dependence of aggregation behavior on concentration in triblock copolymer solutions: The effect of chain architecture

    International Nuclear Information System (INIS)

    Han, Xiang-Gang; Zhang, Xue-Feng

    2015-01-01

    Using the self-consistent field lattice technique, the effects of concentration and hydrophobic middle block length (where the chain length remains constant) on aggregation behavior are studied in amphiphilic symmetric triblock copolymer solutions. The heat capacity peak for the unimer-micelle transition and the distribution peaks for the different degrees of aggregation for micelles and small aggregates (submicelles) are calculated. Analysis of the conducted computer simulations shows that the transition broadness dependence on concentration is determined by the hydrophobic middle block length, and this dependence is distinctly different when the length of the hydrophobic middle block changes. Different size for small aggregates simultaneously appear in the transition region. As temperature decreases, the number of different size small aggregates for the large hydrophobic middle block length first ascends and then descends in aggregation degree order. These results indicate that any transition broadness change with concentration is related to the mechanism of fragmentation and fusion. These results are helpful for interpreting the aggregation process of amphiphilic copolymers at equilibrium

  8. MO-DE-206-03: Quantifying Metabolism with Hyperpolarized MR

    Energy Technology Data Exchange (ETDEWEB)

    Bankson, J. [The University of Texas M.D. Anderson Cancer Center (United States)

    2016-06-15

    In this symposium jointly sponsored by the World Molecular Imaging Society (WMIS) and the AAPM, luminary speakers on imaging metabolism will discuss three impactful topics. The first presentation on Cellular Metabolism of FDG will be given by Guillem Pratx (Stanford). This presentation will detail new work on looking at how the most common molecular imaging agent, fluoro-deoxy-glucose is metabolized at a cellular level. This will be followed by a talk on an improved approach to whole-body PET imaging by Simon Cherry (UC Davis). Simon’s work on a new whole-body PET imaging system promises to have dramatic improvement in our ability to detect and characterize cancer using PET. Finally, Jim Bankson (MD Anderson) will discuss extremely sophisticated approaches to quantifying hyperpolarized-13-C pyruvate metabolism using MR imaging. This technology promises to compliment the exquisite sensitivity of PET with an ability to measure not just uptake, but tumor metabolism. Learning Objectives: Understand the metabolism of FDG at a cellular level. Appreciate the engineering related to a novel new high-sensitivity whole-body PET imaging system. Understand the process of hyperpolarization, how pyruvate relates to metabolism and how advanced modeling can be used to better quantify this data. G. Pratx, Funding: 5R01CA186275, 1R21CA193001, and Damon Runyon Cancer Foundation. S. Cherry, National Institutes of Health; University of California, Davis; Siemens Medical SolutionsJ. Bankson, GE Healthcare; NCI P30-CA016672; CPRIT PR140021-P5.

  9. Molecular MRI in the Earth's Magnetic Field Using Continuous Hyperpolarization of a Biomolecule in Water.

    Science.gov (United States)

    Rovedo, Philipp; Knecht, Stephan; Bäumlisberger, Tim; Cremer, Anna Lena; Duckett, Simon B; Mewis, Ryan E; Green, Gary G R; Burns, Michael; Rayner, Peter J; Leibfritz, Dieter; Korvink, Jan G; Hennig, Jürgen; Pütz, Gerhard; von Elverfeldt, Dominik; Hövener, Jan-Bernd

    2016-06-30

    In this work, we illustrate a method to continuously hyperpolarize a biomolecule, nicotinamide, in water using parahydrogen and signal amplification by reversible exchange (SABRE). Building on the preparation procedure described recently by Truong et al. [ J. Phys. Chem. B , 2014 , 118 , 13882 - 13889 ], aqueous solutions of nicotinamide and an Ir-IMes catalyst were prepared for low-field NMR and MRI. The (1)H-polarization was continuously renewed and monitored by NMR experiments at 5.9 mT for more than 1000 s. The polarization achieved corresponds to that induced by a 46 T magnet (P = 1.6 × 10(-4)) or an enhancement of 10(4). The polarization persisted, although reduced, if cell culture medium (DPBS with Ca(2+) and Mg(2+)) or human cells (HL-60) were added, but was no longer observable after the addition of human blood. Using a portable MRI unit, fast (1)H-MRI was enabled by cycling the magnetic field between 5 mT and the Earth's field for hyperpolarization and imaging, respectively. A model describing the underlying spin physics was developed that revealed a polarization pattern depending on both contact time and magnetic field. Furthermore, the model predicts an opposite phase of the dihydrogen and substrate signal after one exchange, which is likely to result in the cancelation of some signal at low field.

  10. Determination of solute organic concentration in contaminated soils using a chemical-equilibrium soil column system

    DEFF Research Database (Denmark)

    Gamst, Jesper; Kjeldsen, Peter; Christensen, Thomas Højlund

    2007-01-01

    using two soils with different content of organic carbon (f(oc) of 1.5 and 6.5%, respectively). A quadruple blind test of the ER-V system using glass beads in stead of soil showed an acceptable recovery (65-85%) of all of the 11 VOCs tested. Only for the most volatile compound (heptane, K-H similar...... to 80) an unacceptable recovery was found (9%). The contact time needed for obtaining chemical equilibrium was tested in the ER-H system by performing five test with different duration (1, 2, 4, 7 and 19 days) using the low organic carbon soil. Seven days of contact time appeared sufficient...... for determination of solute concentration in a contaminated soil were developed; (1) a chemical Equilibrium and Recirculation column test for Volatile organic chemicals (ER-V) and (2) a chemical Equilibrium and Recirculation column test for Hydrophobic organic chemicals (ER-H). The two test systems were evaluated...

  11. Concentration in the European electricity industry: The internal market as solution?

    International Nuclear Information System (INIS)

    Domanico, Fabio

    2007-01-01

    This article offers an analysis of the present competitive and regulatory framework of the European electricity sector and the results achieved with the liberalisation process. Considering the reactions of incumbents to the liberalisation, the focus in this work is mainly on the problem of market concentration in the sector. The new trends toward the creation of 'national champions' as well as recent mergers between gas suppliers and electricity producers raise serious concerns about abuses of market power and risk of future collusion. In particular, the strategic linkage of existing markets and the expansion into new ones are analyzed in the light of the multimarket contact theory. Considering investment in interconnection among Member States, the internal market issue is investigated as a solution to the 'risks' coming from liberalisation

  12. Concentration in the European electricity industry: The internal market as solution?

    Energy Technology Data Exchange (ETDEWEB)

    Domanico, Fabio [Department of Economics, Luiss Guido Carli University, 1, Via O. Tommasini, 00162 Roma (Italy)

    2007-10-15

    This article offers an analysis of the present competitive and regulatory framework of the European electricity sector and the results achieved with the liberalisation process. Considering the reactions of incumbents to the liberalisation, the focus in this work is mainly on the problem of market concentration in the sector. The new trends toward the creation of 'national champions' as well as recent mergers between gas suppliers and electricity producers raise serious concerns about abuses of market power and risk of future collusion. In particular, the strategic linkage of existing markets and the expansion into new ones are analyzed in the light of the multimarket contact theory. Considering investment in interconnection among Member States, the internal market issue is investigated as a solution to the 'risks' coming from liberalisation. (author)

  13. Structure Manipulation of Carbon Aerogels by Managing Solution Concentration of Precursor and Its Application for CO2 Capture

    Directory of Open Access Journals (Sweden)

    Pingping He

    2018-04-01

    Full Text Available A series of carbon aerogels were synthesized by polycondensation of resorcinol and formaldehyde, and their structure was adjusted by managing solution concentration of precursors. Carbon aerogels were characterized by X-ray diffraction (XRD, Raman, Fourier transform infrared spectroscopy (FTIR, N2 adsorption/desorption and scanning electron microscope (SEM technologies. It was found that the pore structure and morphology of carbon aerogels can be efficiently manipulated by managing solution concentration. The relative micropore volume of carbon aerogels, defined by Vmicro/Vtol, first increased and then decreased with the increase of solution concentration, leading to the same trend of CO2 adsorption capacity. Specifically, the CA-45 (the solution concentration of precursors is 45 wt% sample had the highest CO2 adsorption capacity (83.71 cm3/g and the highest selectivity of CO2/N2 (53 at 1 bar and 0 °C.

  14. Influence of concentration on the radiolytic decomposition of thiamine, riboflavin, and pyridoxine in aqueous solution

    Directory of Open Access Journals (Sweden)

    Guadalupe Albarrán

    2014-10-01

    Full Text Available Vitamin loss during irradiation has been claimed as a critical area in food irradiation technology, especially that of thiamine (B1, which has been considered as the most sensitive to radiation. Although it has been suggested that no vitamin deficiency could result from consuming irradiated food, a long debate on the loss of vitamins and other nutrients during food irradiation has been maintained by the lack of experimental studies monitoring decomposition rates at different concentrations and doses. Since thiamine, riboflavin, and pyridoxine are labile vitamins, this study has focused on their radiolytic decomposition in dilute aqueous solutions in the presence of air. The decomposition process was followed by HPLC and UV-spectroscopy. The results obtained in aqueous solutions showed a dependence of the decomposition as a nonlinear function of the dose. Of these three compounds, the decomposition was higher for thiamine than for riboflavin and even less in pyridoxine.

  15. The present state of research on the vitrification of concentrated solutions of fission products (1962)

    International Nuclear Information System (INIS)

    Bonniaud, R.; Sombret, C.

    1961-01-01

    The present report gives the actual point of studies on vitrification of concentrated solutions of fission products. An active cell, giving glasses in crucibles, permitted to study various glass compositions. The leaching rate from the glass raises 1 to 2 10 -7 g of glass/cm 2 /day. Activity loss by volatility during vitrification remains weak and often below 0.1 per cent of total activity. Off gas cleaning is made easier by presence of filter which is compound of granules including iron oxide. After saturation the content of this filter can be melt. Moreover different processes are in experimentation for a more important production. Daily 72 liters of solution containing tracer activity are treated in a continuous calcination and vitrification plant. The loss in 106 Ru is still important and a modification of installation has been necessary. A pot vitrification plant is in study. In order to reduce cost of processing the possibility to pour glass after melting is actuality in study. A production set of very active glass is also in project. (authors) [fr

  16. Practical Considerations for Determination of Glass Transition Temperature of a Maximally Freeze Concentrated Solution.

    Science.gov (United States)

    Pansare, Swapnil K; Patel, Sajal Manubhai

    2016-08-01

    Glass transition temperature is a unique thermal characteristic of amorphous systems and is associated with changes in physical properties such as heat capacity, viscosity, electrical resistance, and molecular mobility. Glass transition temperature for amorphous solids is referred as (T g), whereas for maximally freeze concentrated solution, the notation is (T g'). This article is focused on the factors affecting determination of T g' for application to lyophilization process design and frozen storage stability. Also, this review provides a perspective on use of various types of solutes in protein formulation and their effect on T g'. Although various analytical techniques are used for determination of T g' based on the changes in physical properties associated with glass transition, the differential scanning calorimetry (DSC) is the most commonly used technique. In this article, an overview of DSC technique is provided along with brief discussion on the alternate analytical techniques for T g' determination. Additionally, challenges associated with T g' determination, using DSC for protein formulations, are discussed. The purpose of this review is to provide a practical industry perspective on determination of T g' for protein formulations as it relates to design and development of lyophilization process and/or for frozen storage; however, a comprehensive review of glass transition temperature (T g, T g'), in general, is outside the scope of this work.

  17. Experiments on the incorporation of concentrated solutions of fission products in glasses and micas

    International Nuclear Information System (INIS)

    Bonniaud, R.; Cohen, P.; Sombret, C.

    1958-01-01

    1) The plants designed for extracting the plutonium of the G1, G2, G3 reactors fuel rods will produce extremely concentrated solutions of fission products. 2) Let us consider a synthetic solution of the 'G2' type: (2N NO 3 H - 2,25 meq/cm 3 AI +++ - 5.10 -3 134 Cs - 137 Cs tracer). We made various glasses and micas by adding and mixing the necessary adjuvants and baking (900 to 1400 deg. C) in a graphite crucible. 3) The products obtained had either the shape of a cylindrical pellet or were reduced into a fine powder. They were mixed with 300 cm 3 of synthetic sea water during variable periods of time in order to study leaching of the activity. 4) Experiments were first carried on caesium because of its solubility. 5) Fabrication of micas on a large scale sets many technological problems more difficult to solve (1400 deg. C) than in the case of glasses (1000 deg. C). A comparative study on both micas and glasses showed that leaching of activity was more important in the micas. (author) [fr

  18. Effect of Na2CO3 degumming concentration on LiBr-formic acid-silk fibroin solution properties

    Directory of Open Access Journals (Sweden)

    Liu Zhi

    2016-01-01

    Full Text Available Salt-acid system has been proved to be of high efficiency for silk fibroin dissolution. Using salt-acid system to dissolve silk, native silk fibrils can be preserved in the regenerated solution. Increasing experiments indicate that acquirement of silk fibrils in solution is strongly associated with the degumming process. In this study, the effect of sodium carbonate degumming concentration on solution properties based on lithium bromide-formic acid dissolution system was systematically investigated. Results showed that the morphology transformation of silk fibroin in solution from nanospheres to nanofibrils is determined by sodium carbonate concentration during the degumming process. Solutions containing different silk fibroin structure exhibited different rheological behaviors and different electrospinnability, leading to different electrospun nanofibre properties. The results have guiding significance for preparation and application of silk fibroin solutions.

  19. Concentration dependence of the partial volume, viscosity, and electric conductivity of solutions of lithium salts in aliphatic alcohols

    International Nuclear Information System (INIS)

    Eliseeva, O.V.; Golubev, V.V.

    2003-01-01

    Concentration dependence of partial volumes, electric conductivity and viscosity of lithium nitrate and chloride solutions in methanol, propanol, isopropanol, butanol, isobutanol, pentanol and isopentanol at 298.15 K were studied by the methods of densimetry, conductometry and viscosimetry. Structural specific features of the solutions studied are discussed on the basis of the calculated volumetric characteristics of the substance dissolved and solvent [ru

  20. Concentrated aqueous sodium chloride solution in clays at thermodynamic conditions of hydraulic fracturing: Insight from molecular dynamics simulations

    Science.gov (United States)

    Svoboda, Martin; Lísal, Martin

    2018-06-01

    To address a high salinity of flow-back water during hydraulic fracturing, we use molecular dynamics (MD) simulations and study the thermodynamics, structure, and diffusion of concentrated aqueous salt solution in clay nanopores. The concentrated solution results from the dissolution of a cubic NaCl nanocrystal, immersed in an aqueous NaCl solution of varying salt concentration and confined in clay pores of a width comparable to the crystal size. The size of the nanocrystal equals to about 18 Å which is above a critical nucleus size. We consider a typical shale gas reservoir condition of 365 K and 275 bar, and we represent the clay pores as pyrophyllite and Na-montmorillonite (Na-MMT) slits. We employ the Extended Simple Point Charge (SPC/E) model for water, Joung-Cheatham model for ions, and CLAYFF for the slit walls. We impose the pressure in the normal direction and the resulting slit width varies from about 20 to 25 Å when the salt concentration in the surrounding solution increased from zero to an oversaturated value. By varying the salt concentration, we observe two scenarios. First, the crystal dissolves and its dissolution time increases with increasing salt concentration. We describe the dissolution process in terms of the number of ions in the crystal, and the crystal size and shape. Second, when the salt concentration reaches a system solubility limit, the crystal grows and attains a new equilibrium size; the crystal comes into equilibrium with the surrounding saturated solution. After crystal dissolution, we carry out canonical MD simulations for the concentrated solution. We evaluate the hydration energy, density profiles, orientation distributions, hydrogen-bond network, radial distribution functions, and in-plane diffusion of water and ions to provide insight into the microscopic behaviour of the concentrated aqueous sodium chloride solution in interlayer galleries of the slightly hydrophobic pyrophyllite and hydrophilic Na-MMT pores.

  1. Axonal and glial currents activated during the post-tetanic hyperpolarization in non-myelinated nerve.

    Science.gov (United States)

    Robert, A; Jirounek, P

    1998-07-01

    Changes in membrane potential and potassium concentration in the extracellular space ([K+]e) of rabbit vagus nerve were measured simultaneously during electrical activity and during the period of recovery using a modified sucrose-gap method and potassium-sensitive microelectrodes. After stimulation for 15 s at 15 Hz the main activity-induced increase in [K+]e reached 16.9 mM. This increase in [K+]e was paralleled by a depolarization of the preparation. The period of activity was followed by a post-tetanic hyperpolarization (PTH) lasting tens of seconds, generated by the axonal electrogenic Na+-K+ pump and to a lesser extent by the pump of the surrounding Schwann cells. The amplitude of the PTH dramatically increased in experiments in which inward currents were blocked by removal of Cl– or after application of Cs+ or Ba2+, indicating that under normal conditions the current generated by the Na+-K+ pump is strongly short-circuited. A pharmacological and kinetic study showed that these currents are: (1) the hyperpolarization-activated current I h, and (2) the inwardly rectifying I KIR current. The results show that the latter originates from Schwann cells. Our data indicate that in non-myelinated nerves there is a subtle association of inward ionic channels which (1) helps the cell to maintain an optimal membrane potential after a period of activity, and (2) contributes to the removal of excess K+ from the extracellular space.

  2. Separation of copper flotation concentrates into density fractions by means of polytungstate aqueous solution

    Directory of Open Access Journals (Sweden)

    Luszczkiewicz Andrzej

    2016-01-01

    Full Text Available Industrial and laboratory flotation copper concentrates were subjected to separation into density fractions by means of heavy liquids in the form of sodium polytungstate aqueous solutions. For two samples, three densities factions were created, however in different density ranges. The density fractions were analyzed to establish the content of copper, lead, silver and organic carbon. The size of particles in both samples was similar (90-95% −0.071 mm. It was found that the lightest density fractions −2.45 and −2.0 g/cm3 still contained sulfide minerals scattered in the organic carbon bearing particles. Removal of the lightest density fraction (−2.0 g/cm3 from the industrial concentrate samples led to considerable reduction of organic carbon (92% and increasing its quality from 13 to 28% Cu. The mineralogical analysis of the heavy liquid separation products showed that most sulfide minerals were evenly dissemination in the heaviest density fractions with the recovery of 95-98%. The lightest density fraction of −2.0 g/cm3, being the richest in organic carbon, contained approximately 3% of unliberated sulfide minerals.

  3. New Culture Medium Containing Ionic Concentrations of Nutrients Similar to Concentrations Found in the Soil Solution

    Science.gov (United States)

    Angle, J. Scott; McGrath, Stephen P.; Chaney, Rufus L.

    1991-01-01

    A new growth medium which closely approximates the composition of the soil solution is presented. This soil solution equivalent (SSE) medium contains the following components (millimolar): NO3, 2.5; NH4, 2.5; HPO4, 0.005; Na, 2.5; Ca, 4.0; Mg, 2.0; K, 0.503; Cl, 4.0; SO4, 5.0; ethylenediamine-di(o-hydroxyphenylacetic acid), 0.02; and MES [2-(N-morpholino)ethanesulfonic acid] (to maintain the pH at 6.0), 10, plus 0.1% arabinose. The advantages of the SSE medium are discussed. PMID:16348614

  4. [Influence of an infusion of 5- or 20% glucose solution on blood glucose and inorganic phosphate concentrations in dairy cows].

    Science.gov (United States)

    Aldaek, T A A; Failing, K; Wehrend, A; Klymiuk, M C

    2011-01-01

    The study was performed to evaluate the influence of an intravenous infusion of 5% and 20% dextrose solution on the plasma concentration of glucose and inorganic phosphate in healthy, dairy cows. Ten healthy, lactating, nonpregnant 3 to 6 year-old Holstein-Friesian cows were included in this investigation. The daily milk yield was 20.3±2.7 liters. Blood plasma concentrations of inorganic phosphate and glucose were determined before, during, immediately and 60 minutes after infusion of 0.9% physiological saline, 5% or 20% dextrose solution. A statistically significant influence of dextrose infusion on blood glucose concentration was observed. After 20% dextrose infusion (200 g dextrose) the blood glucose concentration increased by approximately 13.26 mmol/l. The administration of 5% dextrose solution (50 g dextrose) yielded an increase of blood glucose concentration by 3.31 mmol/l. There was no significant correlation between plasma inorganic phosphate concentrations and infusion of 0.9% saline, 5% or 20% dextrose solution. Intravenous administration of 1000 ml of 5% or 20% dextrose solution does not induce a lasting plasma phosphate reduction and is suitable for elevating the blood glucose concentration.

  5. A different interpretation of Einstein's viscosity equation provides accurate representations of the behavior of hydrophilic solutes to high concentrations.

    Science.gov (United States)

    Zavitsas, Andreas A

    2012-08-23

    Viscosities of aqueous solutions of many highly soluble hydrophilic solutes with hydroxyl and amino groups are examined with a focus on improving the concentration range over which Einstein's relationship between solution viscosity and solute volume, V, is applicable accurately. V is the hydrodynamic effective volume of the solute, including any water strongly bound to it and acting as a single entity with it. The widespread practice is to relate the relative viscosity of solute to solvent, η/η(0), to V/V(tot), where V(tot) is the total volume of the solution. For solutions that are not infinitely dilute, it is shown that the volume ratio must be expressed as V/V(0), where V(0) = V(tot) - V. V(0) is the volume of water not bound to the solute, the "free" water solvent. At infinite dilution, V/V(0) = V/V(tot). For the solutions examined, the proportionality constant between the relative viscosity and volume ratio is shown to be 2.9, rather than the 2.5 commonly used. To understand the phenomena relating to viscosity, the hydrodynamic effective volume of water is important. It is estimated to be between 54 and 85 cm(3). With the above interpretations of Einstein's equation, which are consistent with his stated reasoning, the relation between the viscosity and volume ratio remains accurate to much higher concentrations than those attainable with any of the other relations examined that express the volume ratio as V/V(tot).

  6. Determination of the free ion concentration of trace metals in soil solution using a soil column Donnan membrane technique

    NARCIS (Netherlands)

    Weng, L.; Temminghoff, E.J.M.; Riemsdijk, van W.H.

    2001-01-01

    Accurate measurement of the free metal ion is difficult, especially for trace metals present in very small concentrations (less than micromolar) in natural systems. The recently developed Donnan membrane technique can measure the concentrations in solution in the presence of inorganic and organic

  7. Magnetic Resonance Angiography in the Pig using Hyperpolarized Water

    DEFF Research Database (Denmark)

    Lipsø, Hans Kasper Wigh; Bowen, Sean; Laustsen, Christoffer

    , the magnetization achievable with hyperpolarized water is superior to other nuclei. Methods A 1 mL sample of 50% water and 50% glycerol with 30 mM TEMPO is polarized in a Spinlab (GE Healthcare) at 5 T, 0.9 K, 139.9 GHz for an hour. The sample is rapidly dissolved in 16 mL deoxygenized dissolution medium (DM......Introduction Magnetic Resonance Angiography (MRA) is an important tool in diagnostics of medical conditions such as emboli, stenosis and aneurysms. Sub-millimetre resolution can be obtained with proton imaging, and further optimization can be obtained with Gd-based blood pool agents1. However......, the acquisition time is several minutes, and conventional MRA methods thus fail to image within a single respiration or heartbeat and therefore suffers from motion artefacts. We demonstrate that hyperpolarized (HP) water can be used as an imaging agent to provide subsecond angiographies in pigs. Previous work...

  8. Continuous hyperpolarization with parahydrogen in a membrane reactor

    Science.gov (United States)

    Lehmkuhl, Sören; Wiese, Martin; Schubert, Lukas; Held, Mathias; Küppers, Markus; Wessling, Matthias; Blümich, Bernhard

    2018-06-01

    Hyperpolarization methods entail a high potential to boost the sensitivity of NMR. Even though the "Signal Amplification by Reversible Exchange" (SABRE) approach uses para-enriched hydrogen, p-H2, to repeatedly achieve high polarization levels on target molecules without altering their chemical structure, such studies are often limited to batch experiments in NMR tubes. Alternatively, this work introduces a continuous flow setup including a membrane reactor for the p-H2, supply and consecutive detection in a 1 T NMR spectrometer. Two SABRE substrates pyridine and nicotinamide were hyperpolarized, and more than 1000-fold signal enhancement was found. Our strategy combines low-field NMR spectrometry and a membrane flow reactor. This enables precise control of the experimental conditions such as liquid and gas pressures, and volume flow for ensuring repeatable maximum polarization.

  9. The influence of plutonium concentration and solution flow rate on the effective capacity of macroporous anion exchange resin

    International Nuclear Information System (INIS)

    Marsh, S.F.; Gallegos, T.D.

    1987-07-01

    The principal aqueous process used to recover and purify plutonium at the Los Alamos Plutonium Facility is anion exchange in nitric acid. Previous studies with gel-type anion exchange resin have shown an inverse relationship between plutonium concentration in the feed solution and the optimum flow rate for this process. Because gel-type resin has been replaced with macroporous resin at Los Alamos, the relationship between plutonium concentration and solution flow rate was reexamined with the selected Lewatit MP-500-FK resin using solutions of plutonium in nitric acid and in nitric acid with high levels of added nitrate salts. Our results with this resin differ significantly from previous data obtained with gel-type resin. Flow-rate variation from 10 to 80 liters per hour had essentially no effect on the measured quantities of plutonium sorbed by the macroporous resin. However, the effect of plutonium concentration in the feed solutions was pronounced, as feed solutions that contained the highest concentrations of plutonium also produced the highest resin loadings. The most notable effect of high concentrations of dissolved nitrate salts in these solutions was an increased resin capacity for plutonium at low flow rates. 16 refs., 7 figs., 2 tabs

  10. Absorption capacity and viscosity for CO_2 capture process using high concentrated PZ-DEAE aqueous solution

    International Nuclear Information System (INIS)

    Fu, Dong; Wang, LeMeng; Mi, ChenLu; Zhang, Pan

    2016-01-01

    Highlights: • Absorption of CO_2 in high concentrated DEAE-PZ aqueous solutions were measured. • Viscosities of CO_2-unloaded and CO_2-loaded DEAE-PZ aqueous solutions were measured. • Weiland equation was used to calculate the viscosities. • Effects of temperature, concentration and CO_2 loading on viscosity were demonstrated. - Abstract: The absorption capacity of CO_2 in piperazine (PZ) promoted 2-diethylaminoethanol (DEAE) aqueous solution was measured. The viscosities of both CO_2-unloaded and CO_2-loaded PZ-DEAE aqueous solutions were measured and then modelled. The temperatures ranged from 303.2 K to 323.2 K. The mass fraction of PZ and DEAE respectively ranged from 0 to 0.075 and 0.3 to 0.5. The temperature and concentration dependences of absorption capacity were determined. The effects of temperature, mass fraction and CO_2 loading on viscosities are demonstrated.

  11. The rheology of oxide dispersions and the role of concentrated electrolyte solutions

    International Nuclear Information System (INIS)

    Biggs, Simon; Tindley, Amy

    2007-01-01

    Stability control of particulate dispersions is critical to a wide range of industrial processes. In the UK nuclear industry, significant volumes of waste materials arising from the corrosion products of Magnox fuel rods currently require treatment and storage. The majority of this waste is present as aqueous dispersions of oxide particulates. Treatment of these dispersions will require a variety of unit operations including mobilisation, transport and solid- liquid separation. Typically these processes must operate across a narrow optimal range of pH and the dispersions are, almost without exception, found in complex electrolyte conditions of high overall concentration. Knowledge of the behaviour of oxides in various electrolyte conditions and over a large pH range is essential for the efficient design and control of any waste processing approach. The transport properties of particle dispersions are characterised by the rheological properties. It is well known that particle dispersion rheology is strongly influenced by particle-particle interaction forces, and that particle-particle interactions are strongly influenced by adsorbed ions on the particle surfaces. Here we correlate measurements of the shear yield stress and the particle zeta potentials to provide insight as to the role of ions in moderating particle interactions. The zeta potential of model TiO 2 suspensions were determined (Colloidal Dynamics Zeta Probe) over a range of pH for a series of alkali metal halides and quaternary ammonium halides at a range of solution concentrations (0.001 M - 1 M). The results show some surprising co-ion effects at high electrolyte concentrations (>0.5 M) and indicate that even ions generally considered to be indifferent induce a shift in iso-electric point (i.e.p.) which is inferred as being due to specific adsorption of ions. The shear yield stress values of concentrated titania dispersions were measured using a Bohlin C-VOR stress controlled rheometer. The shear

  12. Optical hyperpolarization of 13C nuclear spins in nanodiamond ensembles

    Science.gov (United States)

    Chen, Q.; Schwarz, I.; Jelezko, F.; Retzker, A.; Plenio, M. B.

    2015-11-01

    Dynamical nuclear polarization holds the key for orders of magnitude enhancements of nuclear magnetic resonance signals which, in turn, would enable a wide range of novel applications in biomedical sciences. However, current implementations of DNP require cryogenic temperatures and long times for achieving high polarization. Here we propose and analyze in detail protocols that can achieve rapid hyperpolarization of 13C nuclear spins in randomly oriented ensembles of nanodiamonds at room temperature. Our protocols exploit a combination of optical polarization of electron spins in nitrogen-vacancy centers and the transfer of this polarization to 13C nuclei by means of microwave control to overcome the severe challenges that are posed by the random orientation of the nanodiamonds and their nitrogen-vacancy centers. Specifically, these random orientations result in exceedingly large energy variations of the electron spin levels that render the polarization and coherent control of the nitrogen-vacancy center electron spins as well as the control of their coherent interaction with the surrounding 13C nuclear spins highly inefficient. We address these challenges by a combination of an off-resonant microwave double resonance scheme in conjunction with a realization of the integrated solid effect which, together with adiabatic rotations of external magnetic fields or rotations of nanodiamonds, leads to a protocol that achieves high levels of hyperpolarization of the entire nuclear-spin bath in a randomly oriented ensemble of nanodiamonds even at room temperature. This hyperpolarization together with the long nuclear-spin polarization lifetimes in nanodiamonds and the relatively high density of 13C nuclei has the potential to result in a major signal enhancement in 13C nuclear magnetic resonance imaging and suggests functionalized and hyperpolarized nanodiamonds as a unique probe for molecular imaging both in vitro and in vivo.

  13. Administration of platelet concentrates suspended in bicarbonated Ringer's solution in children who had platelet transfusion reactions.

    Science.gov (United States)

    Kobayashi, J; Yanagisawa, R; Ono, T; Tatsuzawa, Y; Tokutake, Y; Kubota, N; Hidaka, E; Sakashita, K; Kojima, S; Shimodaira, S; Nakamura, T

    2018-02-01

    Adverse reactions to platelet transfusions are a problem. Children with primary haematological and malignant diseases may experience allergic transfusion reactions (ATRs) to platelet concentrates (PCs), which can be prevented by giving washed PCs. A new platelet additive solution, using bicarbonated Ringer's solution and acid-citrate-dextrose formula A (BRS-A), may be better for platelet washing and storage, but clinical data are scarce. A retrospective cohort study for consecutive cases was performed between 2013 and 2017. For 24 months, we transfused washed PCs containing BRS-A to children with primary haematological and malignant diseases and previous adverse reactions. Patients transfused with conventional PCs (containing residual plasma) were assigned as controls, and results were compared in terms of frequency of ATRs, corrected count increment (CCI) and occurrence of bleeding. We also studied children transfused with PCs washed by a different system as historical controls. Thirty-two patients received 377 conventional PC transfusions. ATRs occurred in 12 (37·5%) patients from transfused with 18 (4·8%) bags. Thirteen patients, who experienced reactions to regular PCs in plasma, then received 119 transfusion bags of washed PCs containing BRS-A, and none had ATRs to washed PCs containing BRS-A. Before study period, six patients transfused 137 classical washed PCs with different platelet additive solution, under same indication, ATRs occurred in one (16·7%) patient from transfused with one (0·7%) bags. CCIs (24 h) in were lower with classical washed PCs (1·26 ± 0·54) compared to regular PCs in plasma (2·07 ± 0·76) (P < 0·001), but there was no difference between washed PCs containing BRS-A (2·14 ± 0·77) and regular PCs (2·21 ± 0·79) (P = 0·769), and we saw no post-transfusion bleeding. Washed PCs containing BRS-A appear to prevent ATRs without loss of transfusion efficacy in children with primary haematological and malignant

  14. In-core LOCA-s: analytical solution for the delayed mixing model for moderator poison concentration

    International Nuclear Information System (INIS)

    Firla, A.P.

    1995-01-01

    Solutions to dynamic moderator poison concentration model with delayed mixing under single pressure tube / calandria tube rupture scenario are discussed. Such a model is described by a delay differential equation, and for such equations the standard ways of solution are not directly applicable. In the paper an exact, direct time-domain analytical solution to the delayed mixing model is presented and discussed. The obtained solution has a 'marching' form and is easy to calculate numerically. Results of the numerical calculations based on the analytical solution indicate that for the expected range of mixing times the existing uniform mixing model is a good representation of the moderator poison mixing process for single PT/CT breaks. However, for postulated multi-pipe breaks ( which is very unlikely to occur ) the uniform mixing model is not adequate any more; at the same time an 'approximate' solution based on Laplace transform significantly overpredicts the rate of poison concentration decrease, resulting in excessive increase in the moderator dilution factor. In this situation the true, analytical solution must be used. The analytical solution presented in the paper may also serve as a bench-mark test for the accuracy of the existing poison mixing models. Moreover, because of the existing oscillatory tendency of the solution, special care must be taken in using delay differential models in other applications. (author). 3 refs., 3 tabs., 8 figs

  15. Evolution of ion damage at 773K in Ni- containing concentrated solid-solution alloys

    Science.gov (United States)

    Shi, Shi; He, Mo-Rigen; Jin, Ke; Bei, Hongbin; Robertson, Ian M.

    2018-04-01

    Quantitative analysis of the impact of the compositional complexity in a series of Ni-containing concentrated solid-solution alloys, Ni, NiCo, NiFe, NiCoCr, NiCoFeCr, NiCoFeCrMn and NiCoFeCrPd, on the evolution of defects produced by 1 MeV Kr ion irradiation at 773 K is reported. The dynamics of the evolution of the damage structure during irradiation to a dose of 2 displacements per atom were observed directly by performing the ion irradiations in electron transparent foils in a transmission electron microscope coupled to an ion accelerator. The defect evolution was assessed through measurement of the defect density, defect size and fraction of perfect and Frank loops. These three parameters were dependent on the alloying element as well as the number of elements. The population of loops was sensitive to the ion dose and alloy composition as faulted Frank loops were observed to unfault to perfect loops with increasing ion dose. These dependences are explained in terms of the influence of each element on the lifetime of the displacement cascade as well as on defect formation and migration energies.

  16. Radiation-induced segregation on defect clusters in single-phase concentrated solid-solution alloys

    International Nuclear Information System (INIS)

    Lu, Chenyang; Yang, Taini; Jin, Ke; Gao, Ning; Xiu, Pengyuan; Zhang, Yanwen; Gao, Fei; Bei, Hongbin; Weber, William J.; Sun, Kai; Dong, Yan; Wang, Lumin

    2017-01-01

    A group of single-phase concentrated solid-solution alloys (SP-CSAs), including NiFe, NiCoFe, NiCoFeCr, as well as a high entropy alloy NiCoFeCrMn, was irradiated with 3 MeV Ni"2"+ ions at 773 K to a fluence of 5 × 10"1"6 ions/cm"2 for the study of radiation response with increasing compositional complexity. Advanced transmission electron microscopy (TEM) with electron energy loss spectroscopy (EELS) was used to characterize the dislocation loop distribution and radiation-induced segregation (RIS) on defect clusters in the SP-CSAs. The results show that a higher fraction of faulted loops exists in the more compositionally complex alloys, which indicate that increasing compositional complexity can extend the incubation period and delay loop growth. The RIS behaviors of each element in the SP-CSAs were observed as follows: Ni and Co tend to enrich, but Cr, Fe and Mn prefer to deplete near the defect clusters. RIS level can be significantly suppressed by increasing compositional complexity due to the sluggish atom diffusion. According to molecular static (MS) simulations, “disk” like segregations may form near the faulted dislocation loops in the SP-CSAs. Segregated elements tend to distribute around the whole faulted loop as a disk rather than only around the edge of the loop.

  17. G eobacter sp. SD-1 with enhanced electrochemical activity in high-salt concentration solutions

    KAUST Repository

    Sun, Dan; Call, Douglas; Wang, Aijie; Cheng, Shaoan; Logan, Bruce E.

    2014-01-01

    © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd. Summary: An isolate, designated strain SD-1, was obtained from a biofilm dominated by Geobacter sulfurreducens in a microbial fuel cell. The electrochemical activity of strain SD-1 was compared with type strains, G.sulfurreducensPCA and Geobacter metallireducensGS-15, and a mixed culture in microbial electrolysis cells. SD-1 produced a maximum current density of 290±29Am-3 in a high-concentration phosphate buffer solution (PBS-H, 200mM). This current density was significantly higher than that produced by the mixed culture (189±44Am-3) or the type strains (<70Am-3). In a highly saline water (SW; 50mM PBS and 650mM NaCl), current by SD-1 (158±4Am-3) was reduced by 28% compared with 50mM PBS (220±4Am-3), but it was still higher than that of the mixed culture (147±19Am-3), and strains PCA and GS-15 did not produce any current. Electrochemical tests showed that the improved performance of SD-1 was due to its lower charge transfer resistance and more negative potentials produced at higher current densities. These results show that the electrochemical activity of SD-1 was significantly different than other Geobacter strains and mixed cultures in terms of its salt tolerance.

  18. G eobacter sp. SD-1 with enhanced electrochemical activity in high-salt concentration solutions

    KAUST Repository

    Sun, Dan

    2014-07-16

    © 2014 Society for Applied Microbiology and John Wiley & Sons Ltd. Summary: An isolate, designated strain SD-1, was obtained from a biofilm dominated by Geobacter sulfurreducens in a microbial fuel cell. The electrochemical activity of strain SD-1 was compared with type strains, G.sulfurreducensPCA and Geobacter metallireducensGS-15, and a mixed culture in microbial electrolysis cells. SD-1 produced a maximum current density of 290±29Am-3 in a high-concentration phosphate buffer solution (PBS-H, 200mM). This current density was significantly higher than that produced by the mixed culture (189±44Am-3) or the type strains (<70Am-3). In a highly saline water (SW; 50mM PBS and 650mM NaCl), current by SD-1 (158±4Am-3) was reduced by 28% compared with 50mM PBS (220±4Am-3), but it was still higher than that of the mixed culture (147±19Am-3), and strains PCA and GS-15 did not produce any current. Electrochemical tests showed that the improved performance of SD-1 was due to its lower charge transfer resistance and more negative potentials produced at higher current densities. These results show that the electrochemical activity of SD-1 was significantly different than other Geobacter strains and mixed cultures in terms of its salt tolerance.

  19. Effect of uranyl nitrate and free acid concentration in feed solution of gelation on UO2 kernel quality

    International Nuclear Information System (INIS)

    Masduki, B.; Wardaya; Widarmoko, A.

    1996-01-01

    An investigation on the effect of uranium and free nitric acid concentration of uranyl nitrate as feed of gelation process on quality of UO 2 kernel was done.The investigation is to look for some concentration of uranyl nitrate solutions those are optimum as feed for preparation of gelled UO 3 . Uranyl nitrate solution of various concentration of uranium (450; 500; 550; 600; 650; 700 g/l) and free nitric acid of (0.9; 1.0; 1.1 N) was made into feed solutions by adding urea and HMTA with mole ratio of urea/uranium and HMTA/uranium 2.1 and 2.0. The feed solutions were changed into spherical gelled UO 3 by dropping was done to get the optimum concentrations of uranyl nitrate solutions. The gelled UO 3 was soaked and washed with 2.5% ammonia solution for 17 hours, dried at 70 o C, calcined at 350 o C for 3 hours then reduced at 850 o C for 3 hours. At every step of the steps process the colour and percentage of well product of gelled UO 3 were noticed. The density and O/U ratio of end product (UO 2 kernel) was determined, the percentage of well product of all steps process was also determined. The three factor were used to chose the optimum concentration of uranyl nitrate solution. From this investigation it was concluded that the optimum concentration of uranyl nitrate was 600 g/l uranium with free nitric acid 0,9 - 1,0 N, the percentage of well product was 97% density of 6.12 - 4.8 g/cc and O/U ratio of 2.15 - 2.06. (author)

  20. [Analyze nanofiltration separation rule of chlorogenic acid from low concentration ethanol by Donnan effect and solution-diffusion effect].

    Science.gov (United States)

    Li, Cun-Yu; Liu, Li-Cheng; Jin, Li-Yang; Li, Hong-Yang; Peng, Guo-Ping

    2017-07-01

    To separate chlorogenic acid from low concentration ethanol and explore the influence of Donnan effect and solution-diffusion effect on the nanofiltration separation rule. The experiment showed that solution pH and ethanol volume percent had influences on the separation of chlorogenic acid. Within the pH values from 3 to 7 for chlorogenic acid in 30% ethanol, the rejection rate of chlorogenic acid was changed by 70.27%. Through the response surface method for quadratic regression model, an interaction had been found in molecule weight cut-off, pH and ethanol volume percent. In fixed nanofiltration apparatus, the existence states of chlorogenic acid determinedits separation rules. With the increase of ethanol concentration, the free form chlorogenic acid was easily adsorbed, dissolved on membrane surface and then caused high transmittance due to the solution-diffusion effect. However, at the same time, due to the double effects of Donnan effect and solution-diffusion effect, the ionic state of chlorogenic acid was hard to be adsorbed in membrane surface and thus caused high rejection rate. The combination of Box-Behnken design and response surface analysis can well optimize the concentrate process by nanofiltration, and the results showed that nanofiltration had several big advantages over the traditional vacuum concentrate technology, meanwhile, and solved the problems of low efficiency and serious component lossesin the Chinese medicines separation process for low concentration organic solvent-water solution. Copyright© by the Chinese Pharmaceutical Association.

  1. Predicting the activity coefficients of free-solvent for concentrated globular protein solutions using independently determined physical parameters.

    Directory of Open Access Journals (Sweden)

    Devin W McBride

    Full Text Available The activity coefficient is largely considered an empirical parameter that was traditionally introduced to correct the non-ideality observed in thermodynamic systems such as osmotic pressure. Here, the activity coefficient of free-solvent is related to physically realistic parameters and a mathematical expression is developed to directly predict the activity coefficients of free-solvent, for aqueous protein solutions up to near-saturation concentrations. The model is based on the free-solvent model, which has previously been shown to provide excellent prediction of the osmotic pressure of concentrated and crowded globular proteins in aqueous solutions up to near-saturation concentrations. Thus, this model uses only the independently determined, physically realizable quantities: mole fraction, solvent accessible surface area, and ion binding, in its prediction. Predictions are presented for the activity coefficients of free-solvent for near-saturated protein solutions containing either bovine serum albumin or hemoglobin. As a verification step, the predictability of the model for the activity coefficient of sucrose solutions was evaluated. The predicted activity coefficients of free-solvent are compared to the calculated activity coefficients of free-solvent based on osmotic pressure data. It is observed that the predicted activity coefficients are increasingly dependent on the solute-solvent parameters as the protein concentration increases to near-saturation concentrations.

  2. Thermodynamics of curium(III) in concentrated electrolyte solutions: formation of sulfate complexes in NaCl/Na2SO4 solutions

    International Nuclear Information System (INIS)

    Paviet, P.; Fanghaenel, T.; Klenze, R.; Kim, J.I.

    1996-01-01

    The formation of sulfate complexes of Curium in aqueous solutions is studied by time resolved laser fluorescence spectroscopy (TRLFS) at 25 C. The species Cm 3+ , Cm(SO 4 ) - , Cm(SO 4 ) - 2 and Cm(SO 4 ) 3- 3 are quantified spectroscopically in the trace concentration range by peak deconvolution of fluorescence emission spectra. The complex formation equilibria are measured in NaCl/ Na 2 SO 4 solutions of constant ionic strength (3 molal) as a function of the sulfate concentration. The stability constants of Cm(SO 4 ) + and Cm(SO 4 ) - 2 are determined to be log β 1 = 0.93±0.08 and log β 2 = 0.61±0.08, respectively. The complex Cm(SO 4 ) 3- 3 is found to be stable only at very high sulfate concentrations (above 1 molal) and therefore not considered for further evaluation. (orig.)

  3. Nitrogen and potassium concentrations in the nutrients solution for melon plants growing in coconut fiber without drainage.

    Science.gov (United States)

    Gratieri, Luiz Augusto; Cecílio Filho, Arthur Bernardes; Barbosa, José Carlos; Pavani, Luiz Carlos

    2013-01-01

    With the objective of evaluating the effects of N and K concentrations for melon plants, an experiment was carried out from July 1, 2011 to January 3, 2012 in Muzambinho city, Minas Gerais State, Brazil. The "Bonus no. 2" was cultivated at the spacing of 1.1 × 0.4. The experimental design was a randomized complete block with three replications in a 4 × 4 factorial scheme with four N concentrations (8, 12, 16, and 20 mmol L(-1)) and four K concentrations (4, 6, 8, and 10 mmol L(-1)). The experimental plot constituted of eight plants. It was observed that the leaf levels of N and K, of N-NO₃ and of K, and the electrical conductivity (CE) of the substrate increased with the increment of N and K in the nutrients' solution. Substratum pH, in general, was reduced with increments in N concentration and increased with increasing K concentrations in the nutrients' solution. Leaf area increased with increments in N concentration in the nutrients solution. Fertigation with solutions stronger in N (20 mmol L(-1)) and K (10 mmol L(-1)) resulted in higher masses for the first (968 g) and the second (951 g) fruits and crop yield (4,425 gm(-2)).

  4. Nitrogen and Potassium Concentrations in the Nutrients Solution for Melon Plants Growing in Coconut Fiber without Drainage

    Directory of Open Access Journals (Sweden)

    Luiz Augusto Gratieri

    2013-01-01

    Full Text Available With the objective of evaluating the effects of N and K concentrations for melon plants, an experiment was carried out from July 1, 2011 to January 3, 2012 in Muzambinho city, Minas Gerais State, Brazil. The “Bonus no. 2” was cultivated at the spacing of 1.1 × 0.4. The experimental design was a randomized complete block with three replications in a 4 × 4 factorial scheme with four N concentrations (8, 12, 16, and 20 mmol L−1 and four K concentrations (4, 6, 8, and 10 mmol L−1. The experimental plot constituted of eight plants. It was observed that the leaf levels of N and K, of N-NO3 and of K, and the electrical conductivity (CE of the substrate increased with the increment of N and K in the nutrients' solution. Substratum pH, in general, was reduced with increments in N concentration and increased with increasing K concentrations in the nutrients' solution. Leaf area increased with increments in N concentration in the nutrients solution. Fertigation with solutions stronger in N (20 mmol L−1 and K (10 mmol L−1 resulted in higher masses for the first (968 g and the second (951 g fruits and crop yield (4,425 gm−2.

  5. δ- and δ'-shock wave types of singular solutions of systems of conservation laws and transport and concentration processes

    International Nuclear Information System (INIS)

    Shelkovich, V M

    2008-01-01

    This is a survey of some results and problems connected with the theory of generalized solutions of quasi-linear conservation law systems which can admit delta-shaped singularities. They are the so-called δ-shock wave type solutions and the recently introduced δ (n) -shock wave type solutions, n=1,2,..., which cannot be included in the classical Lax-Glimm theory. The case of δ- and δ'-shock waves is analyzed in detail. A specific analytical technique is developed to deal with such solutions. In order to define them, some special integral identities are introduced which extend the concept of weak solution, and the Rankine-Hugoniot conditions are derived. Solutions of Cauchy problems are constructed for some typical systems of conservation laws. Also investigated are multidimensional systems of conservation laws (in particular, zero-pressure gas dynamics systems) which admit δ-shock wave type solutions. A geometric aspect of such solutions is considered: they are connected with transport and concentration processes, and the balance laws of transport of 'volume' and 'area' to δ- and δ'-shock fronts are derived for them. For a 'zero-pressure gas dynamics' system these laws are the mass and momentum transport laws. An algebraic aspect of these solutions is also considered: flux-functions are constructed for them which, being non-linear, are nevertheless uniquely defined Schwartz distributions. Thus, a singular solution of the Cauchy problem generates algebraic relations between its components (distributions).

  6. Behaviour of symmetric solutions of a nonlinear elliptic field equation in the semi-classical limit: Concentration around a circle

    Directory of Open Access Journals (Sweden)

    Teresa D'Aprile

    2000-11-01

    Full Text Available In this paper we study the existence of concentrated solutions of the nonlinear field equation $$ -h^{2}Delta v+V(xv-h^{p}Delta_{p}v+ W'(v=0,, $$ where $v:{mathbb R}^{N}o{mathbb R}^{N+1}$, $Ngeq 3$, $p>N$, the potential $V$ is positive and radial, and $W$ is an appropriate singular function satisfying a suitable symmetric property. Provided that $h$ is sufficiently small, we are able to find solutions with a certain spherical symmetry which exhibit a concentration behaviour near a circle centered at zero as $ho 0^{+}$. Such solutions are obtained as critical points for the associated energy functional; the proofs of the results are variational and the arguments rely on topological tools. Furthermore a penalization-type method is developed for the identification of the desired solutions.

  7. The effective concentration of red betel leaf (Piper crocatum infusion as root canal irrigant solution

    Directory of Open Access Journals (Sweden)

    Fani Pangabdian

    2012-03-01

    Full Text Available Background: Smear layer is a debris consisting of organic and inorganic particles of calcified tissue, necrotic tissue, pulp tissue, and dentinoblast and microorganism processes that can close the entrance to the dentin tubuli. Smear layer, will not only inhibit the penetration of disinfection materials and sealers to the dentin tubuli, but will also reduce the attachment of root canal filling material so that root canal irrigation solution is needed to dissolve the smear layer. Red betel leaf (Piper crocatum infusion, on the other hand, contains saponin characterized as “surfactants” which can dissolve smear layer. Nevertheless, the effective concentration of the red betel leaf infusion has still not been known clearly. Purpose: This study is aimed to determine the effective concentration of the red betel leaf infusion for cleaning root canal walls from smear layer. Methods: Fiveteen extracted human teeth with straight single roots were randomized into 5 groups (n=3. The specimens were then shaped by using rotary instruments up to a size of 25/.07. During instrumentation, each canal was irrigated with 10, 20, 30 and, 40% red betel leaf infusion for treatment groups, while another was irrigated with aquadest for the control group. Root canal cleanliness was observed by using scanning electron microscope (SEM. Results: There were significant differences among treatment groups (p<0.05, except in the treatment groups irrigated with red betel leaf infusion with concentrations of 30% and 40% (p>0.05. Conclusion: It can be concluded that red betel leaf infusion with a concentration of 30% is effective for cleaning the root canal walls from the smear layer.Latar belakang: Smear layer adalah suatu debris yang mengandung partikel organik dan anorganik dari jaringan terkalsifikasi, jaringan nekrotik, proses dentinoblas, jaringan pulpa dan mikroorganisme yang dapat menutup jalan masuk ke tubuli dentin. Smear layer akan menghalangi penetrasi dari bahan

  8. μ opioid receptor activation hyperpolarizes respiratory-controlling Kölliker-Fuse neurons and suppresses post-inspiratory drive.

    Science.gov (United States)

    Levitt, Erica S; Abdala, Ana P; Paton, Julian F R; Bissonnette, John M; Williams, John T

    2015-10-01

    the neuron in response to either current injection or local application of glutamate. In voltage-clamp recordings the outward current produced by the opioid agonist ME was concentration dependent, reversed at the potassium equilibrium potential and was blocked by BaCl2 , characteristics of a G protein-coupled inwardly rectifying potassium (GIRK) conductance. The clinically used drug morphine produced an outward current in KF neurons with similar potency to morphine-mediated currents in locus coeruleus brain slice preparations. Thus, the population of KF neurons that are hyperpolarized by μ opioid agonists are likely mediators of the opioid-induced loss of post-inspiration and induction of apneusis. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  9. Optimum Concentration of Caudal Ropivacaine & Clonidine - A Satisfactory Analgesic Solution for Paediatric Infraumbilical Surgery Pain.

    Science.gov (United States)

    Narasimhamurthy, Girish Chikkanayakanahalli; Patel, Muralidhara Danappa; Menezes, Yvonne; Gurushanth, Kavyashree Nagenahalli

    2016-04-01

    Ropivacaine is amide local anaesthetic pure S(-)enantiomer of bupivacaine. Its duration of analgesia is similar to that of Bupivacaine (in equivalent doses) but the motor block is slower in onset, less intense, shorter in duration for a given level of sensory block with lesser cardiac side effects but addition of an adjuvant like clonidine which is an imidazoline derivative has been studied for its sedative, anxiolytic and analgesic properties. This study was aimed to show the optimum concentrations of Ropivacaine and Clonidine to maximize analgesia without side effects by evaluating its safety and efficacy. Sixty children aged 2-10 years of ASA grade 1, scheduled to undergo infraumbilical surgeries were randomly allocated to Group A & Group B of 30 each. Group A received 0.2% Ropivacaine with normal saline and Group B received 0.2% Ropivacaine and preservative free Clonidine 1μg/kg, the total volume of solution being 1ml/kg haemodynamic changes were monitored intraoperatively and haemodynamic parameters along with motor blockade, pain score and sedation score were assessed postoperatively. Done with unpaired student t and Mann-Whitney test. The groups were comparable regarding demographic characterstics. The mean duration of analgesia was prolonged in group B (12+2.22 hours) than in group A (6.53+1.16 hours) with p-value <0.001 leading to less rescue analgesia in former group. None of the children in the groups had a pain score of ≥ 4 at the end of 2 hours. A 6.6% and 60% of group A children had score of ≥ 4 at the end of 4(th) & 6(th) hour respectively. None in Group B had a score of ≥ 4. At the end of 8(th) hour, only 6.6% of the children in Group B had a pain score of ≥ 4 whereas it was 33.33% in Group A which is statistically significant. No bradycardia or hypotension and no significant sedation. Combination of Ropivacaine and Clonidine in the concentration used (0.2% ropivacaine and 1μg/kg of clonidine) can be optimal for postoperative analgesia in

  10. Towards an understanding of induced-charge electrokinetics at large applied voltages in concentrated solutions.

    Science.gov (United States)

    Bazant, Martin Z; Kilic, Mustafa Sabri; Storey, Brian D; Ajdari, Armand

    2009-11-30

    The venerable theory of electrokinetic phenomena rests on the hypothesis of a dilute solution of point-like ions in quasi-equilibrium with a weakly charged surface, whose potential relative to the bulk is of order the thermal voltage (kT/e approximately 25 mV at room temperature). In nonlinear electrokinetic phenomena, such as AC or induced-charge electro-osmosis (ACEO, ICEO) and induced-charge electrophoresis (ICEP), several V approximately 100 kT/e are applied to polarizable surfaces in microscopic geometries, and the resulting electric fields and induced surface charges are large enough to violate the assumptions of the classical theory. In this article, we review the experimental and theoretical literatures, highlight discrepancies between theory and experiment, introduce possible modifications of the theory, and analyze their consequences. We argue that, in response to a large applied voltage, the "compact layer" and "shear plane" effectively advance into the liquid, due to the crowding of counterions. Using simple continuum models, we predict two general trends at large voltages: (i) ionic crowding against a blocking surface expands the diffuse double layer and thus decreases its differential capacitance, and (ii) a charge-induced viscosity increase near the surface reduces the electro-osmotic mobility; each trend is enhanced by dielectric saturation. The first effect is able to predict high-frequency flow reversal in ACEO pumps, while the second may explain the decay of ICEO flow with increasing salt concentration. Through several colloidal examples, such as ICEP of an uncharged metal sphere in an asymmetric electrolyte, we show that nonlinear electrokinetic phenomena are generally ion-specific. Similar theoretical issues arise in nanofluidics (due to confinement) and ionic liquids (due to the lack of solvent), so the paper concludes with a general framework of modified electrokinetic equations for finite-sized ions.

  11. Modeling reactive geochemical transport of concentrated aqueous solutions in variably saturated media

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Guoxiang; Zheng, Zuoping; Wan, Jiamin

    2004-01-28

    Concentrated aqueous solutions (CAS) have unique thermodynamic and physical properties. Chemical components in CAS are incompletely dissociated, especially those containing divalent or polyvalent ions. The problem is further complicated by the interaction between CAS flow processes and the naturally heterogeneous sediments. As the CAS migrates through the porous media, the composition may be altered subject to fluid-rock interactions. To effectively model reactive transport of CAS, we must take into account ion-interaction. A combination of the Pitzer ion-interaction and the ion-association model would be an appropriate way to deal with multiple-component systems if the Pitzer' parameters and thermodynamic data of dissolved components and the related minerals are available. To quantify the complicated coupling of CAS flow and transport, as well as the involved chemical reactions in natural and engineered systems, we have substantially extended an existing reactive biogeochemical transport code, BIO-CORE{sup 2D}{copyright}, by incorporating a comprehensive Pitzer ion-interaction model. In the present paper, the model, and two test cases against measured data were briefly introduced. Finally we present an application to simulate a laboratory column experiment studying the leakage of the high alkaline waste fluid stored in Hanford (a site of the U.S. Department of Energy, located in Washington State, USA). With the Pitzer ion-interaction ionic activity model, our simulation captures measured pH evolution. The simulation indicates that all the reactions controlling the pH evolution, including cation exchanges, mineral precipitation and dissolution, are coupled.

  12. Hyperpolarized krypton-83 as a contrast agent for magnetic resonance imaging.

    Science.gov (United States)

    Pavlovskaya, Galina E; Cleveland, Zackary I; Stupic, Karl F; Basaraba, Randall J; Meersmann, Thomas

    2005-12-20

    For the first time, magnetic resonance imaging (MRI) with hyperpolarized (hp) krypton-83 (83Kr) has become available. The relaxation of the nuclear spin of 83Kr atoms (I = 9/2) is driven by quadrupolar interactions during brief adsorption periods on surrounding material interfaces. Experiments in model systems reveal that the longitudinal relaxation of hp 83Kr gas strongly depends on the chemical composition of the materials. The relaxation-weighted contrast in hp 83Kr MRI allows for the distinction between hydrophobic and hydrophilic surfaces. The feasibility of hp 83Kr MRI of airways is tested in canine lung tissue by using krypton gas with natural abundance isotopic distribution. Additionally, the influence of magnetic field strength and the presence of a breathable concentration of molecular oxygen on longitudinal relaxation are investigated.

  13. Different nonideality relationships, different databases and their effects on modeling precipitation from concentrated solutions using numerical speciation codes

    Energy Technology Data Exchange (ETDEWEB)

    Brown, L.F.; Ebinger, M.H.

    1996-08-01

    Four simple precipitation problems are solved to examine the use of numerical equilibrium codes. The study emphasizes concentrated solutions, assumes both ideal and nonideal solutions, and employs different databases and different activity-coefficient relationships. The study uses the EQ3/6 numerical speciation codes. The results show satisfactory material balances and agreement between solubility products calculated from free-energy relationships and those calculated from concentrations and activity coefficients. Precipitates show slightly higher solubilities when the solutions are regarded as nonideal than when considered ideal, agreeing with theory. When a substance may precipitate from a solution dilute in the precipitating substance, a code may or may not predict precipitation, depending on the database or activity-coefficient relationship used. In a problem involving a two-component precipitation, there are only small differences in the precipitate mass and composition between the ideal and nonideal solution calculations. Analysis of this result indicates that this may be a frequent occurrence. An analytical approach is derived for judging whether this phenomenon will occur in any real or postulated precipitation situation. The discussion looks at applications of this approach. In the solutes remaining after the precipitations, there seems to be little consistency in the calculated concentrations and activity coefficients. They do not appear to depend in any coherent manner on the database or activity-coefficient relationship used. These results reinforce warnings in the literature about perfunctory or mechanical use of numerical speciation codes.

  14. A hyperpolarized equilibrium for magnetic resonance.

    Science.gov (United States)

    Hövener, Jan-Bernd; Schwaderlapp, Niels; Lickert, Thomas; Duckett, Simon B; Mewis, Ryan E; Highton, Louise A R; Kenny, Stephen M; Green, Gary G R; Leibfritz, Dieter; Korvink, Jan G; Hennig, Jürgen; von Elverfeldt, Dominik

    2013-01-01

    Nuclear magnetic resonance spectroscopy and imaging (MRI) play an indispensable role in science and healthcare but use only a tiny fraction of their potential. No more than ≈10 p.p.m. of all ¹H nuclei are effectively detected in a 3-Tesla clinical MRI system. Thus, a vast array of new applications lays dormant, awaiting improved sensitivity. Here we demonstrate the continuous polarization of small molecules in solution to a level that cannot be achieved in a viable magnet. The magnetization does not decay and is effectively reinitialized within seconds after being measured. This effect depends on the long-lived, entangled spin-order of parahydrogen and an exchange reaction in a low magnetic field of 10⁻³ Tesla. We demonstrate the potential of this method by fast MRI and envision the catalysis of new applications such as cancer screening or indeed low-field MRI for routine use and remote application.

  15. Fissile materials in solution concentration measured by active neutron interrogation; Mesure de concentration en matiere fissile dans les liquides par interrogation neutronique active

    Energy Technology Data Exchange (ETDEWEB)

    Romeyer Dherbey, J.; Passard, Ch.; Cloue, J.; Bignan, G.

    1993-12-31

    The use of the active neutron interrogation to measure the concentration of plutonium contained in flow solutions is particularly interesting for fuel reprocessing plants. Indeed, this method gives a signal which is in a direct relation with the fissile materials concentration. Moreover, it is less sensitive to the gamma dose rate than the other nondestructive methods. Two measure methods have been evolved in CEA. Their principles are given into details in this work. The first one consists to detect fission delayed neutrons induced by a {sup 252} Cf source. In the second one fission prompt neutrons induced by a neutron generator of 14 MeV are detected. (O.M.). 6 refs.

  16. Photoluminescence Spectroscopy of Rhodamine 800 Aqueous Solution and Dye-Doped Polymer Thin-Film: Concentration and Solvent Effects

    Science.gov (United States)

    Le, Khai Q.; Dang, Ngo Hai

    2018-05-01

    This paper investigates solvent and concentration effects on photoluminescence (PL) or fluorescence properties of Rhodamine 800 (Rho800) dyes formed in aqueous solution and polymer thin-film. Various commonly used organic solvents including ethanol, methanol and cyclopentanol were studied at a constant dye concentration. There were small changes in the PL spectra for the different solvents in terms of PL intensity and peak wavelength. The highest PL intensity was observed for cyclopentanol and the lowest for ethanol. The longest peak wavelength was found in cyclopentanol (716 nm) and the shortest in methanol (708 nm). Dissolving the dye powder in the methanol solvent and varying the dye concentration in aqueous solution from the high concentrated solution to highly dilute states, the wavelength tunability was observed between about 700 nm in the dilute state and 730 nm at high concentration. Such a large shift may be attributed to the formation of dye aggregates. Rho800 dye-doped polyvinyl alcohol (PVA) polymer thin-film was further investigated. The PL intensity of the dye in the form of thin-film is lower than that of the aqueous solution form whereas the peak wavelength is redshifted due to the presence of PVA. This paper, to our best knowledge, reports the first study of spectroscopic properties of Rho800 dyes in various forms and provides useful guidelines for production of controllable organic luminescence sources.

  17. Enthalpies of solution of methylcalix[4]resorcinarene in non-aqueous solvents as a function of concentration and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Riveros, Diana C. [Laboratorio de Termodinamica de Soluciones, Departamento de Quimica, Facultad de Ciencias, Universidad de los Andes, Bogota D.C. (Colombia); Martinez, Fleming [Grupo de Investigaciones Farmaceutico-Fisicoquimicas, Departamento de Farmacia, Facultad de Ciencias, Universidad Nacional de Colombia, Bogota D.C. (Colombia); Vargas, Edgar F., E-mail: edvargas@uniandes.edu.co [Laboratorio de Termodinamica de Soluciones, Departamento de Quimica, Facultad de Ciencias, Universidad de los Andes, Bogota D.C. (Colombia)

    2012-11-20

    Highlights: Black-Right-Pointing-Pointer The solution enthalpies of methylcalix[4]resorcinarene in alcohols have been measured. Black-Right-Pointing-Pointer The solution enthalpies of methylcalix[4]resorcinarene in alcohols are endothermic. Black-Right-Pointing-Pointer Enthalpies of transference are interpreted in terms of proton donor capacity of alcohols. - Abstract: Enthalpies of solution of 2,8,14,20-tetramethyl-4,6,10,12,16,18,22,24-octahydroxyresorci[4]arene in methanol, ethanol and propanol as a function of molal concentration at (288.15, 298.15 and 308.15) K were measured calorimetrically. The enthalpies of solvation were estimated. Using propanol as the referent solvent, transfer properties to other alcohols were also calculated. In addition, temperature dependence of the enthalpy of solution at infinite dilution was also obtained. The data were interpreted in terms of solute-solvent interactions.

  18. Influence of Monomer Concentration on the Morphologies and Electrochemical Properties of PEDOT, PANI, and PPy Prepared from Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Shalini Kulandaivalu

    2016-01-01

    Full Text Available Poly(3,4-ethylenedioxyhiophene (PEDOT, polyaniline (PANI, and polypyrrole (PPy were prepared on indium tin oxide (ITO substrate via potentiostatic from aqueous solutions containing monomer and lithium perchlorate. The concentration of monomers was varied between 1 and 10 mM. The effects of monomer concentration on the polymers formation were investigated and compared by using Fourier transform infrared spectroscopy (FTIR, Raman spectroscopy, scanning electron microscopy (SEM, cyclic voltammetry (CV, and electrochemical impedance spectroscopy (EIS measurements. FTIR and Raman spectra showed no changes in the peaks upon the increment of the concentration. Based on the SEM images, the increment in monomer concentration gives significant effect on morphologies and eventually affects the electrochemical properties. PEDOT electrodeposited from 10 mM solution showed excellent electrochemical properties with the highest specific capacitance value of 12.8 mF/cm2.

  19. Two-dimensional analytical solutions for chemical transport in aquifers. Part 1. Simplified solutions for sources with constant concentration. Part 2. Exact solutions for sources with constant flux rate

    International Nuclear Information System (INIS)

    Shan, C.; Javandel, I.

    1996-05-01

    Analytical solutions are developed for modeling solute transport in a vertical section of a homogeneous aquifer. Part 1 of the series presents a simplified analytical solution for cases in which a constant-concentration source is located at the top (or the bottom) of the aquifer. The following transport mechanisms have been considered: advection (in the horizontal direction), transverse dispersion (in the vertical direction), adsorption, and biodegradation. In the simplified solution, however, longitudinal dispersion is assumed to be relatively insignificant with respect to advection, and has been neglected. Example calculations are given to show the movement of the contamination front, the development of concentration profiles, the mass transfer rate, and an application to determine the vertical dispersivity. The analytical solution developed in this study can be a useful tool in designing an appropriate monitoring system and an effective groundwater remediation method

  20. Modelling LiBr-H2O solution concentration/crystallization of low thermal-powered absorption air conditioning system

    International Nuclear Information System (INIS)

    Abdullah, M.O.

    2000-01-01

    A computer model is developed to predict the concentration of lithium bromide - water (LiBr-H 2 O) solution for used in low thermal energy-driven absorption air conditioning plants design. The computer program is capable to alert the users from undesirable solidification or crystallization zones. Good agreements between simulated concentration and experimental data from standard chart/table have been obtained. (Author)

  1. Seasonal dynamics of nitrate and ammonium ion concentrations in soil solutions collected using MacroRhizon suction cups.

    Science.gov (United States)

    Kabala, Cezary; Karczewska, Anna; Gałka, Bernard; Cuske, Mateusz; Sowiński, Józef

    2017-07-01

    The aims of the study were to analyse the concentration of nitrate and ammonium ions in soil solutions obtained using MacroRhizon miniaturized composite suction cups under field conditions and to determine potential nitrogen leaching from soil fertilized with three types of fertilizers (standard urea, slow-release urea, and ammonium nitrate) at the doses of 90 and 180 kg ha -1 , applied once or divided into two rates. During a 3-year growing experiment with sugar sorghum, the concentration of nitrate and ammonium ions in soil solutions was the highest with standard urea fertilization and the lowest in variants fertilized with slow-release urea for most of the months of the growing season. Higher concentrations of both nitrogen forms were noted at the fertilizer dose of 180 kg ha -1 . One-time fertilization, at both doses, resulted in higher nitrate concentrations in June and July, while dividing the dose into two rates resulted in higher nitrate concentrations between August and November. The highest potential for nitrate leaching during the growing season was in July. The tests confirmed that the miniaturized suction cups MacroRhizon are highly useful for routine monitoring the concentration of nitrate and ammonium ions in soil solutions under field conditions.

  2. Trends in soil solution dissolved organic carbon (DOC) concentrations across European forests

    NARCIS (Netherlands)

    Camino-Serrano, Marta; Graf Pannatier, Elisabeth; Vicca, Sara; Luyssaert, Sebastiaan; Jonard, Mathieu; Ciais, Philippe; Guenet, Bertrand; Gielen, Bert; Peñuelas, Josep; Sardans, Jordi; Waldner, Peter; Sawicka, Kasia

    2016-01-01

    Dissolved organic carbon (DOC) in surface waters is connected to DOC in soil solution through hydrological pathways. Therefore, it is expected that long-term dynamics of DOC in surface waters reflect DOC trends in soil solution. However, a multitude of site studies have failed so far to establish

  3. Trends in soil solution dissolved organic carbon (DOC) concentrations across European forests

    NARCIS (Netherlands)

    Camino-Serrano, M.; Graf Pannatier, E.; Vicca, S.; Luyssaert, S.; Jonard, M.; Ciais, P.; Guenet, B.; Gielen, B.; Peñuelas, J.; Sardans, J.; Waldner, P.; Etzold, S.; Cecchini, G.; Clarke, N.; Galić, Z.; Gandois, L.; Hansen, K.; Johnson, J.; Klinck, U.; Lachmanová, Z.; Lindroos, A.J.; Meesenburg, H.; Nieminen, T.M.; Sanders, T.G.M.; Sawicka, K.; Seidling, W.; Thimonier, A.; Vanguelova, E.; Verstraeten, A.; Vesterdal, L.; Janssens, I.A.

    2016-01-01

    Dissolved organic carbon (DOC) in surface waters is connected to DOC in soil solution through hydrological pathways. Therefore, it is expected that long-term dynamics of DOC in surface waters reflect DOC trends in soil solution. However, a multitude of site studies have failed so far to establish

  4. Effect of membrane hyperpolarization induced by a K+ channel opener on histamine-induced Ca2+ mobilization in rabbit arterial smooth muscle.

    Science.gov (United States)

    Watanabe, Y; Suzuki, A; Suzuki, H; Itoh, T

    1996-03-01

    1. The role of membrane hyperpolarization on agonist-induced contraction was investigated in intact and alpha-toxin-skinned smooth muscles of rabbit mesenteric artery by use of the ATP-sensitive K+ channel opener, (-)-(3S,4R)-4-(N-acetyl-N-hydroxyamino)-6-cyano-3,4-dihydro-2,2- dimethyl-2H-1-benzopyran-3-ol (Y-26763), and either histamine (Hist) or noradrenaline (NA). 2. Hist (3 microM) and NA (10 microM) both produced a phasic, followed by a tonic increase in intracellular Ca2+ concentration ([Ca2+]i) and force. Y-26763 (10 microM) potently inhibited the NA-induced phasic and tonic increase in [Ca2+]i and force. In contrast, Y-26763 attenuated the Hist-induced phasic increase in [Ca2+]i and force but had almost no effect on the tonic response. However, ryanodine-treatment of muscles in order to inhibit the function of intracellular Ca2+ storage sites altered the action of Y-26763 which now attenuated the Hist-induced tonic increase in [Ca2+]i and force in a concentration-dependent manner (at concentrations > 1 microM). Glibenclamide (10 microM) attenuated the inhibitory action of Y-26763. 3. Hist (3 microM) depolarized the smooth muscle cells to the same extent as NA (10 microM). In the absence of either agonist, Y-26763 (over 30 nM) hyperpolarized the membrane and glibenclamide inhibited this hyperpolarization. Y-26763 (10 microM) almost abolished the NA-induced membrane depolarization, but only slightly attenuated the Hist-induced membrane depolarization in which the delta (delta) value (the difference before and after application of Hist) was not modified by any concentration of Y-26763. In ryanodine-treated smooth muscle cells, Y-26763 hyperpolarized the membrane and potently inhibited the membrane depolarization induced by Hist. 4. In ryanodine-treated muscle, Y-26763 had no measurable effect on the Hist-induced [Ca2+]i-force relationship. Y-26763 also had no apparent effect on the myofilament Ca(2+)-sensitivity in the presence of Hist in alpha

  5. Hyperpolarized 129Xe MRI: A viable functional lung imaging modality?

    International Nuclear Information System (INIS)

    Patz, Samuel; Hersman, F. William; Muradian, Iga; Hrovat, Mirko I.; Ruset, Iulian C.; Ketel, Stephen; Jacobson, Francine; Topulos, George P.; Hatabu, Hiroto; Butler, James P.

    2007-01-01

    The majority of researchers investigating hyperpolarized gas MRI as a candidate functional lung imaging modality have used 3 He as their imaging agent of choice rather than 129 Xe. This preference has been predominantly due to, 3 He providing stronger signals due to higher levels of polarization and higher gyromagnetic ratio, as well as its being easily available to more researchers due to availability of polarizers (USA) or ease of gas transport (Europe). Most researchers agree, however, that hyperpolarized 129 Xe will ultimately emerge as the imaging agent of choice due to its unlimited supply in nature and its falling cost. Our recent polarizer technology delivers vast improvements in hyperpolarized 129 Xe output. Using this polarizer, we have demonstrated the unique property of xenon to measure alveolar surface area noninvasively. In this article, we describe our human protocols and their safety, and our results for the measurement of the partial pressure of pulmonary oxygen (pO 2 ) by observation of 129 Xe signal decay. We note that the measurement of pO 2 by observation of 129 Xe signal decay is more complex than that for 3 He because of an additional signal loss mechanism due to interphase diffusion of 129 Xe from alveolar gas spaces to septal tissue. This results in measurements of an equivalent pO 2 that accounts for both traditional T 1 decay from pO 2 and that from interphase diffusion. We also provide an update on new technological advancements that form the foundation for an improved compact design polarizer as well as improvements that provide another order-of-magnitude scale-up in xenon polarizer output

  6. Astrocytic mitochondrial membrane hyperpolarization following extended oxygen and glucose deprivation.

    Directory of Open Access Journals (Sweden)

    Andrej Korenić

    Full Text Available Astrocytes can tolerate longer periods of oxygen and glucose deprivation (OGD as compared to neurons. The reasons for this reduced vulnerability are not well understood. Particularly, changes in mitochondrial membrane potential (Δψ(m in astrocytes, an indicator of the cellular redox state, have not been investigated during reperfusion after extended OGD exposure. Here, we subjected primary mouse astrocytes to glucose deprivation (GD, OGD and combinations of both conditions varying in duration and sequence. Changes in Δψ(m, visualized by change in the fluorescence of JC-1, were investigated within one hour after reconstitution of oxygen and glucose supply, intended to model in vivo reperfusion. In all experiments, astrocytes showed resilience to extended periods of OGD, which had little effect on Δψ(m during reperfusion, whereas GD caused a robust Δψ(m negativation. In case no Δψ(m negativation was observed after OGD, subsequent chemical oxygen deprivation (OD induced by sodium azide caused depolarization, which, however, was significantly delayed as compared to normoxic group. When GD preceded OD for 12 h, Δψ(m hyperpolarization was induced by both GD and subsequent OD, but significant interaction between these conditions was not detected. However, when GD was extended to 48 h preceding OGD, hyperpolarization enhanced during reperfusion. This implicates synergistic effects of both conditions in that sequence. These findings provide novel information regarding the role of the two main substrates of electron transport chain (glucose and oxygen and their hyperpolarizing effect on Δψ(m during substrate deprivation, thus shedding new light on mechanisms of astrocyte resilience to prolonged ischemic injury.

  7. Structure and Supersaturation of Highly Concentrated Solutions of Buckyball in 1-Butyl-3-Methylimidazolium Tetrafluoroborate

    DEFF Research Database (Denmark)

    Fileti, E. E.; Chaban, V. V.

    2014-01-01

    Solubilization of fullerenes is of high interest because of their wide usage in both fundamental research and numerous applications. This paper reports molecular dynamics (MD) simulations of saturated and supersaturated solutions of C-60 in 1-butyl-3-methylimidazolium tetrafluoroborate, [C4C1IM......-long real-time dynamics. The ion-molecular structure patterns in saturated and supersaturated solutions are distinguished in terms of radial distribution functions and cluster analysis of the solute particles. The cation separated solute pair is found to be a common structure in both saturated......][BF4], room-temperature ionic liquid (RTIL). The simulations cover a wide range of temperatures between 280 and 500 K at ambient pressure. Unlike in simpler solvents, C-60 in [C4C1IM][BF4] forms highly supersaturated solutions, whose internal arrangement remains unaltered during nearly a microsecond...

  8. Onset of local ordering in some copper-based alloys: critical solute concentration vis-a-vis various solutionhardening parameters

    Science.gov (United States)

    Butt, Muhammad Zakria; Noshi, Mozina; Bashir, Farooq

    2008-12-01

    The mode of planar distribution of solute atoms in Cu single crystals alloyed with 0.5 to 8.0 at.%Ge has been investigated via the temperature dependence of the critical resolved shear stress of these alloys. It is found that there exists a critical solute concentration c m ≈ 5 at.%Ge below which the distribution of solute atoms in the crystal is random, and above which some local ordering occurs. This together with such data available in the literature for Cu-Zn, Cu-Al and Cu-Mn alloys, i.e. c m ≈7 at. %Zn, 7 at.%Al and 1 at.%Mn, when examined as a function of the size-misfit factor δ = (1/ b)(d b/d c)of a given binary alloy system, shows that the value of c m strongly depends on δ; the smaller the magnitude of δ, the greater the value of c m and vice versa. Also, the value of c m is found to correlate well with the electron-to-atom ratio ( e/a)of the Cu-Zn, Cu-Al, Cu-Ge and Cu-Mn alloys with the solute concentration c = c m . However, no systematic correlation exists between the critical solute concentration c m for the onset of local ordering and the modulus-mismatch parameter η = (1/ G)(d G/d c).

  9. Brain Imaging Using Hyperpolarized 129Xe Magnetic Resonance Imaging.

    Science.gov (United States)

    Chahal, Simrun; Prete, Braedan R J; Wade, Alanna; Hane, Francis T; Albert, Mitchell S

    2018-01-01

    Hyperpolarized (HP) 129 Xe magnetic resonance imaging (MRI) is a novel iteration of traditional MRI that relies on detecting the spins of 1 H. Since 129 Xe is a gaseous signal source, it can be used for lung imaging. Additionally, 129 Xe dissolves in the blood stream and can therefore be detectable in the brain parenchyma and vasculature. In this work, we provide detailed information on the protocols that we have developed to image 129 Xe within the brains of both rodents and human subjects. © 2018 Elsevier Inc. All rights reserved.

  10. Mechanisms of hyperpolarization in regenerated mature motor axons in cat

    DEFF Research Database (Denmark)

    Moldovan, Mihai; Krarup, Christian

    2004-01-01

    We found persistent abnormalities in the recovery of membrane excitability in long-term regenerated motor nerve fibres in the cat as indicated in the companion paper. These abnormalities could partly be explained by membrane hyperpolarization. To further investigate this possibility, we compared...... the changes in excitability in control nerves and long-term regenerated cat nerves (3-5 years after tibial nerve crush) during manoeuvres known to alter axonal membrane Na(+)-K(+) pump function: polarization, cooling to 20 degrees C, reperfusion after 10 min ischaemia, and up to 60 s of repetitive stimulation...

  11. Hyperpolarized Xenon Nuclear Magnetic Resonance (NMR of Building Stone Materials

    Directory of Open Access Journals (Sweden)

    Michele Mauri

    2012-09-01

    Full Text Available We have investigated several building stone materials, including minerals and rocks, using continuous flow hyperpolarized xenon (CF-HP NMR spectroscopy to probe the surface composition and porosity. Chemical shift and line width values are consistent with petrographic information. Rare upfield shifts were measured and attributed to the presence of transition metal cations on the surface. The evolution of freshly cleaved rocks exposed to the atmosphere was also characterized. The CF-HP 129Xe NMR technique is non-destructive and it could complement currently used techniques, like porosimetry and microscopy, providing additional information on the chemical nature of the rock surface and its evolution.

  12. Dynamically Decoupled 13C Spins in Hyperpolarized Nanodiamond

    Science.gov (United States)

    Rej, Ewa; Gaebel, Torsten; Boele, Thomas; Waddington, David; Reilly, David

    The spin-spin relaxation time, T2, which determines how long a quantum state remains coherent, is an important factor for many applications ranging from MRI to quantum computing. A common technique used in quantum information technology to extend the T2, involves averaging out certain noise spectra via dynamical decoupling sequences. Depending on the nature of the noise in the system, specific sequences, such as CPMG, UDD or KDD, can be tailored to optimize T2. Here we combine hyperpolarization techniques and dynamical decoupling sequences to extend the T2 of 13C nuclear spins in nanodiamond by three orders of magnitude.

  13. The role of level anti-crossings in nuclear spin hyperpolarization

    NARCIS (Netherlands)

    Ivanov, Konstantin L.; Pravdivtsev, Andrey N.; Yurkovskaya, Alexandra V.; Vieth, Hans Martin; Kaptein, R

    2014-01-01

    Nuclear spin hyperpolarization is an important resource for increasing the sensitivity of NMR spectroscopy and MRI. Signal enhancements can be as large as 3-4 orders of magnitude. In hyperpolarization experiments, it is often desirable to transfer the initial polarization to other nuclei of choice,

  14. A novel MR contrast agent for angiography and perfusion: Hyperpolarized water

    DEFF Research Database (Denmark)

    Lipsø, Hans Kasper Wigh

    , hyperpolarized by dissolution Dynamic Nuclear Polarization (d-DNP), can be applied as an MRI contrast agent for angiography and perfusion. The first part of the project focuses on development of a protocol for production of large samples of hyperpolarized protons in D2O. The samples are polarized and dissolved...

  15. Metabolic imaging of patients with prostate cancer using hyperpolarized [1-¹³C]pyruvate

    DEFF Research Database (Denmark)

    Nelson, Sarah J; Kurhanewicz, John; Vigneron, Daniel B

    2013-01-01

    This first-in-man imaging study evaluated the safety and feasibility of hyperpolarized [1-¹³C]pyruvate as an agent for noninvasively characterizing alterations in tumor metabolism for patients with prostate cancer. Imaging living systems with hyperpolarized agents can result in more than 10,000-f...

  16. Can we predict uranium bioavailability based on soil parameters? Part 1: effect of soil parameters on soil solution uranium concentration.

    Science.gov (United States)

    Vandenhove, H; Van Hees, M; Wouters, K; Wannijn, J

    2007-01-01

    Present study aims to quantify the influence of soil parameters on soil solution uranium concentration for (238)U spiked soils. Eighteen soils collected under pasture were selected such that they covered a wide range for those parameters hypothesised as being potentially important in determining U sorption. Maximum soil solution uranium concentrations were observed at alkaline pH, high inorganic carbon content and low cation exchange capacity, organic matter content, clay content, amorphous Fe and phosphate levels. Except for the significant correlation between the solid-liquid distribution coefficients (K(d), L kg(-1)) and the organic matter content (R(2)=0.70) and amorphous Fe content (R(2)=0.63), there was no single soil parameter significantly explaining the soil solution uranium concentration (which varied 100-fold). Above pH=6, log(K(d)) was linearly related with pH [log(K(d))=-1.18 pH+10.8, R(2)=0.65]. Multiple linear regression analysis did result in improved predictions of the soil solution uranium concentration but the model was complex.

  17. Can we predict uranium bioavailability based on soil parameters? Part 1: Effect of soil parameters on soil solution uranium concentration

    International Nuclear Information System (INIS)

    Vandenhove, H.; Hees, M. van; Wouters, K.; Wannijn, J.

    2007-01-01

    Present study aims to quantify the influence of soil parameters on soil solution uranium concentration for 238 U spiked soils. Eighteen soils collected under pasture were selected such that they covered a wide range for those parameters hypothesised as being potentially important in determining U sorption. Maximum soil solution uranium concentrations were observed at alkaline pH, high inorganic carbon content and low cation exchange capacity, organic matter content, clay content, amorphous Fe and phosphate levels. Except for the significant correlation between the solid-liquid distribution coefficients (K d , L kg -1 ) and the organic matter content (R 2 = 0.70) and amorphous Fe content (R 2 = 0.63), there was no single soil parameter significantly explaining the soil solution uranium concentration (which varied 100-fold). Above pH = 6, log(K d ) was linearly related with pH [log(K d ) = - 1.18 pH + 10.8, R 2 = 0.65]. Multiple linear regression analysis did result in improved predictions of the soil solution uranium concentration but the model was complex. - Uranium solubility in soil can be predicted from organic matter or amorphous iron content and pH or with complex multilinear models considering several soil parameters

  18. Conformational Analysis of Proteins in Highly Concentrated Solutions by Dialysis-Coupled Hydrogen/Deuterium Exchange Mass Spectrometry

    DEFF Research Database (Denmark)

    Houde, Damian; Esmail Nazari, Zeinab; Bou-Assaf, George M

    2016-01-01

    When highly concentrated, an antibody solution can exhibit unusual behaviors, which can lead to unwanted properties, such as increased levels of protein aggregation and unusually high viscosity. Molecular modeling, along with many indirect biophysical measurements, has suggested that the cause fo...... in industry. Graphical Abstract ᅟ....

  19. Effect of solution concentration on sealing treatment of Mg-Al hydrotalcite film on AZ91D Mg alloy

    Directory of Open Access Journals (Sweden)

    Qiangsheng Dong

    2017-09-01

    Full Text Available Cerium-based sealing treatment was developed for Mg-Al hydrotalcite film on AZ91D Mg alloy, and the influence of cerium salt solution was investigated to modify the surface integrity and corrosion resistance. Scanning electron microscope (SEM and X-ray diffraction (XRD measurements were carried out to analyze the surface morphology and phase composition. The corrosion resistance of Mg-Al hydrotalcite film after sealing treatment was evaluated by the polarization curve and electrochemical impedance spectroscopy (EIS tests. The results showed that lower concentration of Ce-containing solution was beneficial to seal the micro-cracks on Mg-Al hydrotalcite film, and improve the surface integrity and corrosion resistance; higher concentration of Ce-containing solution could seal fewer micro-cracks, and the corrosion resistance was decreased owing to the disintegration of Mg-Al hydrotalcite film.

  20. Tomato root growth and phosphorus absorption kinetics by tomato plants as affected by phosphorus concentration in nutrient solution

    International Nuclear Information System (INIS)

    Fontes, P.C.R.; Barber, S.A.

    1984-01-01

    To evaluate the effects P concentrations in nutrient solution on root growth and on root physiological characteristics involved in P uptake by tomato Lycopersicon esculentum Mill plants, six seedlings were grown in nutrient solution at initial concentrations of 48.5, 97, 194 and 388 μMP until one day before harvest. They were then transferred to solutions with P at 20 μM and 30 μM, and the depletion curves and Michaelis-Menten parameters were determined. The conclusions were that as P supply increased and as the plant P contents are sufficient for maximum growth, the rate of P uptake tends to be lower. The results also indicate that total P uptake by tomato seedlings depends on the amount of root surface area exposed to P. (M.A.C.) [pt

  1. Oleate induces KATP channel-dependent hyperpolarization in mouse hypothalamic glucose-excited neurons without altering cellular energy charge.

    Science.gov (United States)

    Dadak, Selma; Beall, Craig; Vlachaki Walker, Julia M; Soutar, Marc P M; McCrimmon, Rory J; Ashford, Michael L J

    2017-03-27

    The unsaturated fatty acid, oleate exhibits anorexigenic properties reducing food intake and hepatic glucose output. However, its mechanism of action in the hypothalamus has not been fully determined. This study investigated the effects of oleate and glucose on GT1-7 mouse hypothalamic cells (a model of glucose-excited (GE) neurons) and mouse arcuate nucleus (ARC) neurons. Whole-cell and perforated patch-clamp recordings, immunoblotting and cell energy status measures were used to investigate oleate- and glucose-sensing properties of mouse hypothalamic neurons. Oleate or lowered glucose concentration caused hyperpolarization and inhibition of firing of GT1-7 cells by the activation of ATP-sensitive K + channels (K ATP ). This effect of oleate was not dependent on fatty acid oxidation or raised AMP-activated protein kinase activity or prevented by the presence of the UCP2 inhibitor genipin. Oleate did not alter intracellular calcium, indicating that CD36/fatty acid translocase may not play a role. However, oleate activation of K ATP may require ATP metabolism. The short-chain fatty acid octanoate was unable to replicate the actions of oleate on GT1-7 cells. Although oleate decreased GT1-7 cell mitochondrial membrane potential there was no change in total cellular ATP or ATP/ADP ratios. Perforated patch and whole-cell recordings from mouse hypothalamic slices demonstrated that oleate hyperpolarized a subpopulation of ARC GE neurons by K ATP activation. Additionally, in a separate small population of ARC neurons, oleate application or lowered glucose concentration caused membrane depolarization. In conclusion, oleate induces K ATP- dependent hyperpolarization and inhibition of firing of a subgroup of GE hypothalamic neurons without altering cellular energy charge. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. A method for the gravimetric determination of plutonium in pure plutonium nitrate concentrate solution

    International Nuclear Information System (INIS)

    Mair, M.A.; Savage, D.J.

    1986-12-01

    Plutonium nitrate solution is treated with sulphuric acid before being heated and finally ignited. The stoichiometric plutonium dioxide so formed is weighed and hence the plutonium content is calculated. (author)

  3. Comparison of nanoparticle diffusion using fluorescence correlation spectroscopy and differential dynamic microscopy within concentrated polymer solutions

    Science.gov (United States)

    Shokeen, Namita; Issa, Christopher; Mukhopadhyay, Ashis

    2017-12-01

    We studied the diffusion of nanoparticles (NPs) within aqueous entangled solutions of polyethylene oxide (PEO) by using two different optical techniques. Fluorescence correlation spectroscopy, a method widely used to investigate nanoparticle dynamics in polymer solution, was used to measure the long-time diffusion coefficient (D) of 25 nm radius particles within high molecular weight, Mw = 600 kg/mol PEO in water solutions. Differential dynamic microscopy (DDM) was used to determine the wave-vector dependent dynamics of NPs within the same polymer solutions. Our results showed good agreement between the two methods, including demonstration of normal diffusion and almost identical diffusion coefficients obtained by both techniques. The research extends the scope of DDM to study the dynamics and rheological properties of soft matter at a nanoscale. The measured diffusion coefficients followed a scaling theory, which can be explained by the coupling between polymer dynamics and NP motion.

  4. Separation of radionuclides from spent decontamination solutions and/or evaporator concentrates

    International Nuclear Information System (INIS)

    Sebesta, F.; John, J.; Rosikova, K.; Motl, A.

    1999-01-01

    Separation of radionuclides from spent alkaline decontamination solutions has been tested in model experiments with strontium separation from simulant solution. The composite absorbers tested included TiO-PAN and NaTiO-PAN materials (titanium dioxide or sodium titanate incorporated into a matrix of polyacrylonitrile binder). As an alkaline simulant, solution of 1 M NaOH + 1 M NaNO 3 + 10 -4 M Ca(NO 3 ) 2 + 10 -5 M Sr(NO 3 ) 2 spiked with a carrier-free 85 Sr tracer, was used. The experiments were performed at a flow rate of 12.5 BV/hr. Some experiments with real and simulant spent decontamination solutions are described

  5. Enthalpies of solution of methylcalix[4]resorcinarene in non-aqueous solvents as a function of concentration and temperature

    International Nuclear Information System (INIS)

    Riveros, Diana C.; Martínez, Fleming; Vargas, Edgar F.

    2012-01-01

    Highlights: ► The solution enthalpies of methylcalix[4]resorcinarene in alcohols have been measured. ► The solution enthalpies of methylcalix[4]resorcinarene in alcohols are endothermic. ► Enthalpies of transference are interpreted in terms of proton donor capacity of alcohols. - Abstract: Enthalpies of solution of 2,8,14,20-tetramethyl-4,6,10,12,16,18,22,24-octahydroxyresorci[4]arene in methanol, ethanol and propanol as a function of molal concentration at (288.15, 298.15 and 308.15) K were measured calorimetrically. The enthalpies of solvation were estimated. Using propanol as the referent solvent, transfer properties to other alcohols were also calculated. In addition, temperature dependence of the enthalpy of solution at infinite dilution was also obtained. The data were interpreted in terms of solute–solvent interactions.

  6. Regional alveolar partial pressure of oxygen measurement with parallel accelerated hyperpolarized gas MRI.

    Science.gov (United States)

    Kadlecek, Stephen; Hamedani, Hooman; Xu, Yinan; Emami, Kiarash; Xin, Yi; Ishii, Masaru; Rizi, Rahim

    2013-10-01

    Alveolar oxygen tension (Pao2) is sensitive to the interplay between local ventilation, perfusion, and alveolar-capillary membrane permeability, and thus reflects physiologic heterogeneity of healthy and diseased lung function. Several hyperpolarized helium ((3)He) magnetic resonance imaging (MRI)-based Pao2 mapping techniques have been reported, and considerable effort has gone toward reducing Pao2 measurement error. We present a new Pao2 imaging scheme, using parallel accelerated MRI, which significantly reduces measurement error. The proposed Pao2 mapping scheme was computer-simulated and was tested on both phantoms and five human subjects. Where possible, correspondence between actual local oxygen concentration and derived values was assessed for both bias (deviation from the true mean) and imaging artifact (deviation from the true spatial distribution). Phantom experiments demonstrated a significantly reduced coefficient of variation using the accelerated scheme. Simulation results support this observation and predict that correspondence between the true spatial distribution and the derived map is always superior using the accelerated scheme, although the improvement becomes less significant as the signal-to-noise ratio increases. Paired measurements in the human subjects, comparing accelerated and fully sampled schemes, show a reduced Pao2 distribution width for 41 of 46 slices. In contrast to proton MRI, acceleration of hyperpolarized imaging has no signal-to-noise penalty; its use in Pao2 measurement is therefore always beneficial. Comparison of multiple schemes shows that the benefit arises from a longer time-base during which oxygen-induced depolarization modifies the signal strength. Demonstration of the accelerated technique in human studies shows the feasibility of the method and suggests that measurement error is reduced here as well, particularly at low signal-to-noise levels. Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.

  7. Estimating soil solution nitrate concentration from dielectric spectra using PLS analysis

    Science.gov (United States)

    Fast and reliable methods for in situ monitoring of soil nitrate-nitrogen concentration are vital for reducing nitrate-nitrogen losses to ground and surface waters from agricultural systems. While several studies have been done to indirectly estimate nitrate-nitrogen concentration from time domain s...

  8. Optimising concentrations of antimicrobial agents in pharmaceutical preparations: Case of an oral solution of glycerol and an ophthalmic solution containing cysteamine.

    Science.gov (United States)

    Chan Hew Wai, A; Becasse, P; Tworski, S; Pradeau, D; Planas, V

    2014-11-01

    In the context of current distrust of antimicrobial preservatives, the quantities of these substances in two pharmaceutical formulas were studied: an ophthalmic solution of cysteamine preserved benzalkonium chloride at 1mg/5mL and Glycerotone(®) preserved with sorbic acid at 0.1g/100g. The purpose of this work was to verify that a reduction of the quantities of preservative continues to fulfil the requirements for antimicrobial preservation. The Test of efficacy of antimicrobial preservation, section 5.1.3 of the 8th edition of the European Pharmacopoeia, was carried out on each formulation prepared with decreasing quantities of preservative. The results show that formulations whose preservative concentration was reduced by a factor of four remained compliant with standards. It is to be noted that in formulas without preservative, fungal growth was observed in both the solution of Glycerotone(®) and the ophthalmic solution containing cysteamine. Although there is no question that an antimicrobial preservative is necessary, the quantity of preservative can be reduced without deteriorating the quality of the pharmaceutical product but the minimal effective concentration remains to be determined. The formulations of many pharmaceutical products should therefore be examined in order to limit the quantities of preservative while continuing to guarantee patient's safety. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  9. Measurement of properties of a lithium bromide aqueous solution for the determination of the concentration for a prototype absorption machine

    International Nuclear Information System (INIS)

    Labra, L.; Juárez-Romero, D.; Siqueiros, J.; Coronas, A.; Salavera, D.

    2017-01-01

    Highlights: • Determination of concentration of absorption mixture for absorption heat transformers. • Measurement of physical properties for heat transformer assessment. • Comparative behavior of Electric conductivity, Refractive index, and density of LiBr-H_2O. - Abstract: An electrolyte solution of Lithium Bromide (LiBr) water was chosen for study because of its wide use in prototype absorption machines. The LiBr must be operated close to the temperature and mass fraction at which lithium bromide achieves the highest efficiency. For the purpose of establishing the concentration in a prototype absorption machines, measurements were made of the properties that vary with temperature and concentration. The selected properties are electrical conductivity, density, refractive indexes and sound velocity. The resulting measured properties values were compared with some values found in previous works. The properties of aqueous lithium bromide solutions were measured at the concentration range of 45–65% of LiBr and temperatures range of 20–80 °C. Semi-empirical correlations that determine the properties of lithium bromide are also proposed. The methods for measuring the properties of aqueous solutions were considered taking into account their reliability, simplicity and sampling time.

  10. Analysis methods and performance of an automated system for measuring both concentration and enrichment of uranium in solutions

    International Nuclear Information System (INIS)

    Kelley, T.A.; Parker, J.L.; Sampson, T.E.

    1993-01-01

    For the 1992 INNM meeting, the authors reported on the general characteristics of an automated system--then under development--for measuring both the concentration and enrichment of uranium in solutions. That paper emphasized the automated control capability, the measurement sequences, and safety features of the system. In this paper, the authors report in detail on the measurement methods, the analysis algorithms, and the performance of the delivered system. The uranium concentration is measured by a transmission-corrected X-ray fluorescence method. Cobalt-57 is the fluorescing source and a combined 153 Gd and 57 Co source is used for the transmission measurements. Corrections are made for both the absorption of the exciting 57 Co gamma rays and the excited uranium X-rays. The 235 U concentration is measured by a transmission-corrected method, which employs the 185.7-keV gamma ray of 235 U and a transmission source of 75 Se to make corrections for the self-absorption of the 235 U gamma rays in the solution samples. Both measurements employ high-resolution gamma-ray spectrometry and use the same 50ml sample contained in a custom-molded, flat-bottomed, polypropylene bottle. Both measurements are intended for uranium solutions with concentrations ≥0.1 g U/l, although at higher enrichments the passive measurement will be even more sensitive

  11. Low-Concentration Indium Doping in Solution-Processed Zinc Oxide Films for Thin-Film Transistors

    Directory of Open Access Journals (Sweden)

    Xue Zhang

    2017-07-01

    Full Text Available We investigated the influence of low-concentration indium (In doping on the chemical and structural properties of solution-processed zinc oxide (ZnO films and the electrical characteristics of bottom-gate/top-contact In-doped ZnO thin-film transistors (TFTs. The thermogravimetry and differential scanning calorimetry analysis results showed that thermal annealing at 400 °C for 40 min produces In-doped ZnO films. As the In content of ZnO films was increased from 1% to 9%, the metal-oxygen bonding increased from 5.56% to 71.33%, while the metal-hydroxyl bonding decreased from 72.03% to 9.63%. The X-ray diffraction peaks and field-emission scanning microscope images of the ZnO films with different In concentrations revealed a better crystalline quality and reduced grain size of the solution-processed ZnO thin films. The thickness of the In-doped ZnO films also increased when the In content was increased up to 5%; however, the thickness decreased on further increasing the In content. The field-effect mobility and on/off current ratio of In-doped ZnO TFTs were notably affected by any change in the In concentration. Considering the overall TFT performance, the optimal In doping concentration in the solution-processed ZnO semiconductor was determined to be 5% in this study. These results suggest that low-concentration In incorporation is crucial for modulating the morphological characteristics of solution-processed ZnO thin films and the TFT performance.

  12. Association between mortality and replacement solution bicarbonate concentration in continuous renal replacement therapy: A propensity-matched cohort study.

    Directory of Open Access Journals (Sweden)

    Kianoush Kashani

    Full Text Available Given the known deleterious effects seen with bicarbonate supplementation for acidemia, we hypothesized that utilizing high bicarbonate concentration replacement solution in continuous venovenous hemofiltration (CVVH would be independently associated with higher mortality.In a propensity score-matched historical cohort study conducted at a single tertiary care center from December 9, 2006, through December 31, 2009, a total of 287consecutive adult critically ill patients with Stage III acute kidney injury (AKI requiring CVVH were enrolled. We excluded patients on maintenance dialysis, those who received other modalities of continuous renal replacement therapies, and patients that received a mixed of 22 and 32 mEq/L bicarbonate solution pre- and post-filter. The primary outcome was in-hospital and 90-day mortality rates.Among enrollees, 68 were used 32 mEq/L bicarbonate solution, and 219 received 22mEq/L bicarbonate solution for CVVH. Patients on 32 mEq/L bicarbonate solution were more often non-surgical, had lower pH and bicarbonate level but had higher blood potassium and phosphorus levels in comparison with those on 22 mEq/L bicarbonate solution. After adjustment for the baseline characteristics, the use of 32 bicarbonate solution was significantly associated with increased in-hospital (HR = 1.94; 95% CI 1.02-3.79 and 90-day mortality (HR = 1.50; 95% CI 1.03-2.14. There was a significant increase in the hospital (p = .03 and 90-day (p = .04 mortality between the 22 vs. 32 mEq/L bicarbonate solution groups following propensity matching.Our data showed there is a strong association between using high bicarbonate solution and mortality independent of severity of illness and comorbid conditions. These findings need to be evaluated further in prospective studies.

  13. Fermentation of solutions of glucose-protein concentrate in a cascade-multi-ray unit

    Energy Technology Data Exchange (ETDEWEB)

    Denshchikov, M T; Shashilova, V P

    1964-01-01

    Glucose-protein concentrate is a material obtained by the hydrolysis of corn, containing glucose 75 to 80, maltose, isomaltose, and other non-fermentable sugars 1.5 to 2, H/sub 2/O 15 to 17, mineral matter 1.9 to 1%, and N-containing materials 3.2 to 3.4 g/kg. In earlier fermentation trails with this material, after addition of H/sub 2/O, only 10 to 12% ethanol concentrations were obtained. With period addition of citric acid and replacement of the yeast at regular intervals, using a cascade-multitray unit, 12 to 13% concentrations of ethanol were obtained.

  14. A novel method of non-violent dissolution of sodium metal in a concentrated aqueous solution of Epsom salt

    International Nuclear Information System (INIS)

    Lakshmanan, A.R.; Prasad, M.V.R.; Ponraju, D.; Krishnan, H.

    2004-01-01

    A new technique of non-violent and fast dissolution of sodium metal in a concentrated aqueous solution of Epsom salt (MgSO 4 .7H 2 O) at room temperature (RT) has been developed. The dissolution process is mildly exothermic but could be carried out even in a glass beaker in air under swift stirring condition. The reaction products consist of mixed salts of MgSO 4 and Na 2 SO 4 as well as Mg(OH) 2 which are only mildly alkaline and hence are non-corrosive and non-hazardous unlike NaOH. A 50 mL solution having Epsom salt concentration of 2 M was found to give the optimal composition for disposal of 1 g of sodium. Supersaturated (>2.7 M), as well as dilute (<1.1 M) solutions, however, cause violent reactions and hence should be avoided. Repeated sodium dissolution in Epsom solution produced a solid waste of 4.7 g per g of sodium dissolved which is comparable with the waste (4 g) produced in 8 M NaOH solution. A 1.4 M Epsom solution sprayed with a high-pressure jet cleaner at RT in air easily removed the sodium blocked inside a metal pipe made of mild steel. The above jet also dissolved peacefully residual sodium collected on the metal tray after a sodium fire experiment. No sodium fire or explosion was observed during this campaign. The Epsom solution spray effectively neutralized the minor quantity of sodium aerosol produced during this campaign. This novel technique would hence be quite useful for draining sodium from fast breeder reactor components and bulk processing of sodium as well as for sodium fire fighting

  15. Using fractional extraction method to separate Mo from U in high concentration solution

    International Nuclear Information System (INIS)

    Zhao Pinzhi; Cheng Guangrong; Ma Xiuhua

    1996-01-01

    The author presents investigation on separating Mo from U in acid high concentration lixivium with fractional extraction of secondary amine (7203) and D2EHPA and preparing qualified products of ammonium molybdate and sodium diuranate

  16. Concentrated Polymer Solutions are Different from Melts: Role of Entanglement Molecular Weight

    DEFF Research Database (Denmark)

    Huang, Qian; Mednova, Olga; Rasmussen, Henrik K.

    2013-01-01

    We compare viscoelastic properties of several polystyrene solutions and melts with the same number of entanglements. It is demonstrated that the modulus and time can be shifted such that the linear viscoelastic properties are identical provided the number of entanglements are identical. However...

  17. Applications of Fertilizer Cations Affect Cadmium and Zinc Concentrations in Soil Solutions and Uptake by Plants

    DEFF Research Database (Denmark)

    Lorenz, S. E.; Hamon, R. E.; McGrath, S. P.

    1994-01-01

    A pot experiment was conducted to study changes over time of Cd and Zn in soil solution and in plants. Radish was grown in a soil which had been contaminated with heavy metals prior to 1961. Constant amounts of a fertilizer solution (NH4N03, KN03) were added daily. Soil solution was obtained......-metal (Cd, Zn) ions in soil solutions and a decrease in soil pH, probably due to ion-exchange mechanisms and the dissolution of carbonates. Uptake of Cd and Zn into leaves was correlated with the mass flow of Cd (adjusted r2 = 0.798) and Zn (adjusted r2=0.859). Uptake of K, Ca and Mg by the plants...... at intervals by displacement with water. The cumulative additions of small amounts of fertilizers were made equal to the plants' requirements at the final harvest but were found to exceed them during most of the experiment. Excess fertilizers caused substantial increases of major (K, Ca, Mg) and heavy...

  18. Bromfenac ophthalmic solution 0.09 %: human aqueous humor concentration detected by high-performance liquid chromatography.

    Science.gov (United States)

    Macrì, Angelo; Vagge, Aldo; Salis, Annalisa; Fucile, Carmen; Marini, Valeria; Martelli, Antonietta; Giuffrida, Sebastiano; Iester, Michele; Damonte, Gianluca; Mattioli, Francesca

    2017-04-01

    The purpose of this study was to evaluate the aqueous humor concentrations of bromfenac ophthalmic solution 0.09 % in patients undergoing phacoemulsification. Patients requiring cataract extraction received one drop (50 µL) of bromfenac 0.09 % solution in the eye to be operated, before bedtime the day before surgery or the morning of the surgery. The last administration was recorded. At the time of paracentesis, an aqueous humor sample was collected with a 30-gauge needle attached to a TB syringe and was later analyzed by high-performance liquid chromatography for drug concentration. 188 treated volunteers and 48 control, untreated, subjects were included in the study. The mean aqueous concentration of bromfenac in the treated group was 37.60 ± 68.86 and 0 nM (nmol/L) in the control group (p < 0.0001). Correlation coefficient in bromfenac group between time elapsed from instillation and drug concentration was -0.16 (p not significant). Bromfenac showed properties of good penetration and stable concentration in aqueous humor up to about 12 h after instillation.

  19. Effects of fulvic acid concentration and origin on photodegradation of polycyclic aromatic hydrocarbons in aqueous solution: Importance of active oxygen

    International Nuclear Information System (INIS)

    Xia Xinghui; Li Gongchen; Yang Zhifeng; Chen Yumin; Huang, Gordon H.

    2009-01-01

    With an Xe arc lamp house as simulated sunlight, the influences of fulvic acid (FA) concentration and origins on photodegradation of acenaphthene, fluorine, phenanthrene, fluoranthene and pyrene in aqueous solution have been studied. Similar effects of FAs, collected from five places around China, on polycyclic aromatic hydrocarbon (PAH) photodegradation have been observed. Active oxygen was of significance in PAH photodegradation with the presence of FAs. For systems with 1.25 mg L -1 FAs, the contributions of ·OH to PAH photodegradation rates were from 33% to 69%. FAs had two opposite effects, i.e., stimulating the generation of active oxygen and advancing PAH photodegradation; competing with PAHs for energy and photons and restraining PAH photodegradation. Generally, photodegradation rates of the 5 PAHs decreased with the increase of FAs concentration; except fluoranthene and pyrene were advanced in solutions with low FA concentration. The influences of FA concentration on PAH photodegradation were more significant than FA origin. - Influences of fulvic acid (FA) concentration on PAH photodegradation were more significant than FA origin, and active oxygen played an important role in PAH photodegradation

  20. Head to head comparison of the formulation and stability of concentrated solutions of HESylated versus PEGylated anakinra.

    Science.gov (United States)

    Liebner, Robert; Meyer, Martin; Hey, Thomas; Winter, Gerhard; Besheer, Ahmed

    2015-02-01

    Although PEGylation of biologics is currently the gold standard for half-life extension, the technology has a number of limitations, most importantly the non-biodegradability of PEG and the extremely high viscosity at high concentrations. HESylation is a promising alternative based on coupling to the biodegradable polymer hydroxyethyl starch (HES). In this study, we are comparing HESylation with PEGylation regarding the effect on the protein's physicochemical properties, as well as on formulation at high concentrations, where protein stability and viscosity can be compromised. For this purpose, the model protein anakinra is coupled to HES or PEG by reductive amination. Results show that coupling of HES or PEG had practically no effect on the protein's secondary structure, and that it reduced protein affinity by one order of magnitude, with HESylated anakinra more affine than the PEGylated protein. The viscosity of HESylated anakinra at protein concentrations up to 75 mg/mL was approximately 40% lower than that of PEG-anakinra. Both conjugates increased the apparent melting temperature of anakinra in concentrated solutions. Finally, HESylated anakinra was superior to PEG-anakinra regarding monomer recovery after 8 weeks of storage at 40°C. These results show that HESylating anakinra offers formulation advantages compared with PEGylation, especially for concentrated protein solutions. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  1. Solution of non-steady-state substrate concentration in the action of biosensor response at mixed enzyme kinetics

    Science.gov (United States)

    Senthamarai, R.; Jana Ranjani, R.

    2018-04-01

    In this paper, a mathematical model of an amperometric biosensor at mixed enzyme kinetics and diffusion limitation in the case of substrate inhibition has been developed. The model is based on time dependent reaction diffusion equation containing a non -linear term related to non -Michaelis - Menten kinetics of the enzymatic reaction. Solution for the concentration of the substrate has been derived for all values of parameters using the homotopy perturbation method. All the approximate analytic expressions of substrate concentration are compared with simulation results using Scilab/Matlab program. Finally, we have given a satisfactory agreement between them.

  2. Resin bead-thermal ionization mass spectrometry for determination of plutonium concentration in irradiated fuel dissolver solution

    International Nuclear Information System (INIS)

    Paul, Sumana; Shah, R.V.; Aggarwal, S.K.; Pandey, A.K.

    2015-01-01

    Determination of isotopic composition (IC) and concentration of plutonium (Pu) is necessary at various stages of nuclear fuel cycle which involves analysis of complex matrices like dissolver solution of irradiated fuel, nuclear waste stream etc. Mass spectrometry, e.g. thermal ionization mass spectrometry (TIMS) and inductively coupled plasma mass spectrometry (ICP-MS) are commonly used for determination of IC and concentration of plutonium. However, to circumvent matrix interferences, efficient separation as well as preconcentration of Pu is required prior to mass spectrometric analysis. Purification steps employing ion-exchange resins are widely used for the separation of Pu from dissolver solution or from mixture of other actinides e.g. U, Am. However, an alternative way is to selectively preconcentrate Pu on a resin bead, followed by direct loading of the bead on the filament of thermal ionization mass spectrometer

  3. [Effects of different types and concentration of oral sweet solution on reducing neonatal pain during heel lance procedures].

    Science.gov (United States)

    Leng, Hong-yao; Zheng, Xian-lan; Yan, Li; Zhang, Xian-hong; He, Hua-yun; Xiang, Ming

    2013-09-01

    To compare the effect of different types and concentrations of sweet solutions on neonatal pain during heel lance procedure. Totally 560 full term neonates (male 295, female 265) were randomized into 7 groups:placebo group (plain water), 10% glucose, 25% glucose, 50% glucose, 12% sucrose, 24% sucrose and 30% sucrose groups.In each group, 2 ml corresponding oral solutions were administered through a syringe by dripping into the neonate's mouth 2 minute before heel lance. The procedure process was recorded by videos, from which to collect heart rate, oxygen saturation and pain score 1 min before puncture, 3, 5 and 10 min after puncture. The average heart rate increase 3, 5 and 10 min after procedure in the 25% and 50% glucose groups, 12% and 24% and 30% sucrose groups was significantly lower than those in the placebo group (P lance (both P lance, but the best concentration of sucrose for pain relief needs further study.

  4. The extraction characteristic of Au-Ag from Au concentrate by thiourea solution

    Science.gov (United States)

    Kim, Bongju; Cho, Kanghee; On, Hyunsung; Choi, Nagchoul; Park, Cheonyoung

    2013-04-01

    The cyanidation process has been used commercially for the past 100 years, there are ores that are not amenable to treatment by cyanide. Interest in alternative lixiviants, such as thiourea, halogens, thiosulfate and malononitrile, has been revived as a result of a major increase in gold price, which has stimulated new developments in extraction technology, combined with environmental concern. The Au extraction process using the thiourea solvent has many advantages over the cyanidation process, including higher leaching rates, faster extraction time and less than toxicity. The purpose of this study was investigated to the extraction characteristic of Au-Ag from two different Au concentrate (sulfuric acid washing and roasting) under various experiment conditions (thiourea concentration, pH of solvent, temperature) by thiourea solvent. The result of extraction experiment showed that the Au-Ag extraction was a fast extraction process, reaching equilibrium (maximum extraction rate) within 30 min. The Au-Ag extraction rate was higher in the roasted concentrate than in the sulfuric acid washing. The higher the Au-Ag extraction rate (Au - 70.87%, Ag - 98.12%) from roasted concentrate was found when the more concentration of thiourea increased, pH decreased and extraction temperature increased. This study informs extraction method basic knowledge when thiourea was a possibility to eco-/economic resources of Au-Ag utilization studies including the hydrometallurgy.

  5. Analytical solutions to compartmental indoor air quality models with application to environmental tobacco smoke concentrations measured in a house.

    Science.gov (United States)

    Ott, Wayne R; Klepeis, Neil E; Switzer, Paul

    2003-08-01

    This paper derives the analytical solutions to multi-compartment indoor air quality models for predicting indoor air pollutant concentrations in the home and evaluates the solutions using experimental measurements in the rooms of a single-story residence. The model uses Laplace transform methods to solve the mass balance equations for two interconnected compartments, obtaining analytical solutions that can be applied without a computer. Environmental tobacco smoke (ETS) sources such as the cigarette typically emit pollutants for relatively short times (7-11 min) and are represented mathematically by a "rectangular" source emission time function, or approximated by a short-duration source called an "impulse" time function. Other time-varying indoor sources also can be represented by Laplace transforms. The two-compartment model is more complicated than the single-compartment model and has more parameters, including the cigarette or combustion source emission rate as a function of time, room volumes, compartmental air change rates, and interzonal air flow factors expressed as dimensionless ratios. This paper provides analytical solutions for the impulse, step (Heaviside), and rectangular source emission time functions. It evaluates the indoor model in an unoccupied two-bedroom home using cigars and cigarettes as sources with continuous measurements of carbon monoxide (CO), respirable suspended particles (RSP), and particulate polycyclic aromatic hydrocarbons (PPAH). Fine particle mass concentrations (RSP or PM3.5) are measured using real-time monitors. In our experiments, simultaneous measurements of concentrations at three heights in a bedroom confirm an important assumption of the model-spatial uniformity of mixing. The parameter values of the two-compartment model were obtained using a "grid search" optimization method, and the predicted solutions agreed well with the measured concentration time series in the rooms of the home. The door and window positions in

  6. Concentration of electrolyte reserves of the juvenile african catfish clarias gariepinus (burchell, 1822) exposed to sublethal concentrations of portland cement powder in solution

    International Nuclear Information System (INIS)

    Adamu, M.K.; Francis, O.A.

    2008-01-01

    The study investigated the effect of sublethal concentrations (39.10, 19.55, 9.87 and 0.00 mg/l) of Portland cement powder in solution on the electrolyte reserves (sodium, potassium, calcium, chloride and inorganic phosphorus) in the serum, liver and kidney of the juvenile African catfish Clarias gariepinus after a 15 day exposure period. The basic function of the determined electrolyte reserves in the body lies in controlling fluid distribution, intra and extra cellular acidobasic equilibrium, maintaining osmotic pressure of body fluid and normal neuro-muscular irritability. The result revealed significant (P 0.05) changes in inorganic phosphorus. Sodium, calcium, chloride and inorganic phosphorus and potassium were significantly (P 0.05) different in liver and kidney, respectively. Ipso-facto, the effector organs viz: liver and kidney of teleost species - Clarias gariepinus which are primarily responsible for regulating water and ionic movement between external and internal milieu of fishes are susceptible to deleterious effects of Portland cement powder thus sublethal concentration (39.10 mg/l) of Portland cement powder in solution after a 15 day exposure has been most toxic and debilitating to the test fish. (author)

  7. Separation of cadmium from solutions containing high concentration of zinc ions

    International Nuclear Information System (INIS)

    Sharma, K.D.; Bhutani, A.K.; Parvathisem, P.

    1984-01-01

    In hydrometallurgical process of extracting cadmium as a byproduct, zinc dust is added for separation of cadmium as cadimum sponge. High amounts of zinc are quite often noticed in the cadmium electrolyte subjected for electrowinning of the metal. This leads to poor quality of cadmium deposit and lower current efficiencies. Study of cadmium sponge cementation process revealed that zinc dust may be added to an acidic cadmium solution for precipitation of cadmium sponge without neutralization of the free acidity present in the system. This fact is utilized for obtaining a high cadmium sponge with 75-80 per cent cadmium and 5-10 per cent zinc with 98 per cent recovery of cadmium from the solution as sponge. The suggested process is confirmed in a cadmium production plant producing 11.0 MT of cadmium per month. (author)

  8. Study of the chemical interactions of actinide cations in solution at macroscopic concentrations

    International Nuclear Information System (INIS)

    Maurice, C.

    1983-01-01

    The aim of this work was to study the interactions of pentavalent neptunium in dodecane-diluted tributyl phosphate with other metallic cations, especially uranium VI and ruthenium present in reprocessing solutions. Pentavalent neptunium on its own was shown to exist in several forms complexed by water and TBP and also to dimerise. In the complex it forms with uranium VI the interaction via the neptunyl oxygen is considerably enhanced in organic solution. Dibutyl phosphoric acid strengthens the interaction between neptunium and uranium. The Np V-ruthenium interaction reveals the existence of a new cation-cation complex; the process takes place in two successive stage and leads to the formation, reinforced and accelerated by HDBP, of a highly to the formation, reinforced and accelerated by HDBP, of a highly stable complex. These results contribute towards a better knowledge of the behaviour of neptunium in the reprocessing operation [fr

  9. Molecular Dynamics Investigation of the Effects of Concentration on Hydrogen Bonding in Aqueous Solutions of Methanol, Ethylene Glycol and Glycerol

    International Nuclear Information System (INIS)

    Zhang, Ning; Li, Weizhong; Chen, Cong; Zuo, Jianguo; Weng, Lindong

    2013-01-01

    Hydrogen bonding interaction between alcohols and water molecules is an important characteristic in the aqueous solutions of alcohols. In this paper, a series of molecular dynamics simulations have been performed to investigate the aqueous solutions of low molecular weight alcohols (methanol, ethylene glycol and glycerol) at the concentrations covering a broad range from 1 to 90 mol %. The work focuses on studying the effect of the alcohols molecules on the hydrogen bonding of water molecules in binary mixtures. By analyzing the hydrogen bonding ability of the hydroxyl (-OH) groups for the three alcohols, it is found that the hydroxyl group of methanol prefers to form more hydrogen bonds than that of ethylene glycol and glycerol due to the intra-and intermolecular effects. It is also shown that concentration has significant effect on the ability of alcohol molecule to hydrogen bond water molecules. Understanding the hydrogen bonding characteristics of the aqueous solutions is helpful to reveal the cryoprotective mechanisms of methanol, ethylene glycol and glycerol in aqueous solutions

  10. Volumetric interpretation of protein adsorption: interfacial packing of protein adsorbed to hydrophobic surfaces from surface-saturating solution concentrations.

    Science.gov (United States)

    Kao, Ping; Parhi, Purnendu; Krishnan, Anandi; Noh, Hyeran; Haider, Waseem; Tadigadapa, Srinivas; Allara, David L; Vogler, Erwin A

    2011-02-01

    The maximum capacity of a hydrophobic adsorbent is interpreted in terms of square or hexagonal (cubic and face-centered-cubic, FCC) interfacial packing models of adsorbed blood proteins in a way that accommodates experimental measurements by the solution-depletion method and quartz-crystal-microbalance (QCM) for the human proteins serum albumin (HSA, 66 kDa), immunoglobulin G (IgG, 160 kDa), fibrinogen (Fib, 341 kDa), and immunoglobulin M (IgM, 1000 kDa). A simple analysis shows that adsorbent capacity is capped by a fixed mass/volume (e.g. mg/mL) surface-region (interphase) concentration and not molar concentration. Nearly analytical agreement between the packing models and experiment suggests that, at surface saturation, above-mentioned proteins assemble within the interphase in a manner that approximates a well-ordered array. HSA saturates a hydrophobic adsorbent with the equivalent of a single square or hexagonally-packed layer of hydrated molecules whereas the larger proteins occupy two-or-more layers, depending on the specific protein under consideration and analytical method used to measure adsorbate mass (solution depletion or QCM). Square or hexagonal (cubic and FCC) packing models cannot be clearly distinguished by comparison to experimental data. QCM measurement of adsorbent capacity is shown to be significantly different than that measured by solution depletion for similar hydrophobic adsorbents. The underlying reason is traced to the fact that QCM measures contribution of both core protein, water of hydration, and interphase water whereas solution depletion measures only the contribution of core protein. It is further shown that thickness of the interphase directly measured by QCM systematically exceeds that inferred from solution-depletion measurements, presumably because the static model used to interpret solution depletion does not accurately capture the complexities of the viscoelastic interfacial environment probed by QCM. Copyright © 2010

  11. On the radiolysis of concentrated alkaline and calcium-nitrate solutions

    International Nuclear Information System (INIS)

    Kiwi, J.T.; Daniels, M.

    1978-01-01

    Previous studies have shown that more nitrite is produced than can reasonably be accounted for by an indirect radiolysis mechanism based on the radical products of radiolysed water. Further results on the relative roles of indirect effect and direct effect (a chemical transformation in the solute due to its energy absorption) are presented. Major products are nitrite, peroxide and oxygen and yields can be accounted for using the electron fraction model. (author)

  12. Hydration of the chloride ion in concentrated aqueous solutions using neutron scattering and molecular dynamics

    Czech Academy of Sciences Publication Activity Database

    Pluhařová, Eva; Fischer, H. E.; Mason, Philip E.; Jungwirth, Pavel

    2014-01-01

    Roč. 112, 9/10 (2014), s. 1230-1240 ISSN 0026-8976 R&D Projects: GA ČR GBP208/12/G016; GA MŠk LH12001 Grant - others:GA MŠk(CZ) LM2010005 Institutional support: RVO:61388963 Keywords : lithium * solution * molecular dynamics * chloride * neutron scattering Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.720, year: 2014

  13. Barium low concentration determination in solutions using X rays energy spectrometry

    International Nuclear Information System (INIS)

    Barbosa, Joao Batista Santos; Pereira, Jose dos Santos Jorge

    1999-01-01

    This work was proposed to establish an analytical methodology for barium determination in samples from the Waste Supervision of CDTN. Barium is the focus here because it has the same chemical behaviour as radium. Therefore, barium can replace it as an inactive tracer in contention matrix studies. The methodology is made up of two phases; physical concentration and barium determination by an Energy Dispersive Spectrometer using an Am 241 photon excitation system. A very good set of results is found when Am 241 is used in fluorescing barium atoms. This fact, in addition to the physical concentration process, allows to detect up 12 ppb of elementary barium. (author)

  14. The effect of growing media and concentration of nutrient solution on growth, flowering and macroelement content of media and leaves of Tymophylla tenuiloba Small

    Directory of Open Access Journals (Sweden)

    Joanna Nowak

    2013-12-01

    Full Text Available Effects of growing media and concentration of nutrient solution on growth, flowering, evapotranspiration and macroelement content of media and leaves of Tymophylla tenuiloba were evaluated under ebb-and-flow conditions. Two media: peat and peat + perlite (3:l, v/v, and four concentrations of nutrient solution: 1.0, 1.5, 2.0, 2.5 mS cm-1 were applied. High quality plants were produced in both media and all concentration of nutrient solution. The lowest evapotranspiration was measured at the highest concentration of nutrient solution. N concentration of leaves was high in all treatments. Concentrations of K, Ca, and Mg decreased with increasing concentration of nutrient solution. Opposite was found for P. At the end of cultivation the lowest pH was measured in the upper layer of growing media. The highest total soluble salt level was measured in the upper layers. Upper layers accumulated more N-NO3, P, Ca, and Mg. Mineral element content of both media was high in all concentrations of nutrient solution. Low concentration of nutrient solution at 1.0 mS cm-1 is recommended, although -1Tymophylla tenuiloba-1 can be also cultivated at higher concentrations of nutrient solution up to 2.5mS cm-1, if placed on the same bench with other bedding plants requiring more nutrients.

  15. Eco-friendly luminescent solar concentrators with low reabsorption losses and resistance to concentration quenching based on aqueous-solution-processed thiolate-gold nanoclusters

    Science.gov (United States)

    Huang, H. Y.; Cai, K. B.; Chang, L. Y.; Chen, P. W.; Lin, T. N.; Lin, C. A. J.; Shen, J. L.; Talite, M. J.; Chou, W. C.; Yuan, C. T.

    2017-09-01

    Heavy-metal-containing quantum dots (QDs) with engineered electronic states have been served as luminophores in luminescent solar concentrators (LSCs) with impressive optical efficiency. Unfortunately, those QDs involve toxic elements and need to be synthesized in a hazardous solvent. Recently, biocompatible, eco-friendly gold nanoclusters (AuNCs), which can be directly synthesized in an aqueous solution, have gained much attention for promising applications in ‘green photonics’. Here, we explored the solid-state photophysical properties of aqueous-solution-processed, glutathione-stabilized gold nanoclusters (GSH-AuNCs) with a ligand-to-metal charge-transfer (LMCT) state for developing ‘green’ LSCs. We found that such GSH-AuNCs exhibit a large Stokes shift with almost no spectral overlap between the optical absorption and PL emission due to the LMCT states, thus, suppressing reabsorption losses. Compared with GSH-AuNCs in solution, the photoluminescence quantum yields (PL-QYs) of the LSCs can be enhanced, accompanied with a lengthened PL lifetime owing to the suppression of non-radiative recombination rates. In addition, the LSCs do not suffer from severe concentration-induced PL quenching, which is a common weakness for conventional luminophores. As a result, a common trade-off between light-harvesting efficiency and solid-state PL-QYs can be bypassed due to nearly-zero spectral overlap integral between the optical absorption and PL emission. We expect that GSH-AuNCs hold great promise for serving as luminophores for ‘green’ LSCs by further enhancing solid-state PL-QYs.

  16. Eco-friendly luminescent solar concentrators with low reabsorption losses and resistance to concentration quenching based on aqueous-solution-processed thiolate-gold nanoclusters.

    Science.gov (United States)

    Huang, H Y; Cai, K B; Chang, L Y; Chen, P W; Lin, T N; Lin, C A J; Shen, J L; Talite, M J; Chou, W C; Yuan, C T

    2017-09-15

    Heavy-metal-containing quantum dots (QDs) with engineered electronic states have been served as luminophores in luminescent solar concentrators (LSCs) with impressive optical efficiency. Unfortunately, those QDs involve toxic elements and need to be synthesized in a hazardous solvent. Recently, biocompatible, eco-friendly gold nanoclusters (AuNCs), which can be directly synthesized in an aqueous solution, have gained much attention for promising applications in 'green photonics'. Here, we explored the solid-state photophysical properties of aqueous-solution-processed, glutathione-stabilized gold nanoclusters (GSH-AuNCs) with a ligand-to-metal charge-transfer (LMCT) state for developing 'green' LSCs. We found that such GSH-AuNCs exhibit a large Stokes shift with almost no spectral overlap between the optical absorption and PL emission due to the LMCT states, thus, suppressing reabsorption losses. Compared with GSH-AuNCs in solution, the photoluminescence quantum yields (PL-QYs) of the LSCs can be enhanced, accompanied with a lengthened PL lifetime owing to the suppression of non-radiative recombination rates. In addition, the LSCs do not suffer from severe concentration-induced PL quenching, which is a common weakness for conventional luminophores. As a result, a common trade-off between light-harvesting efficiency and solid-state PL-QYs can be bypassed due to nearly-zero spectral overlap integral between the optical absorption and PL emission. We expect that GSH-AuNCs hold great promise for serving as luminophores for 'green' LSCs by further enhancing solid-state PL-QYs.

  17. The Determination of the Concentrations of Sugar Solutions by Laser Refractometry.

    Science.gov (United States)

    Hughes, Elvin, Jr.; And Others

    1988-01-01

    Presents an easily performed experiment to determine sucrose concentrations using a laser and a hollow glass prism. The experiment is suggested for high school, freshman college, and instrumental analysis classes. Notes an Erlenmeyer flask can be used instead of a prism. (MVL)

  18. Concentrations of danofloxacin 18% solution in plasma, milk and tissues after subcutaneous injection in dairy cows

    International Nuclear Information System (INIS)

    Mestorino, N.; Marchetti, M.L.; Turic, E.; Pesoa, J.; Errecalde, J.

    2009-01-01

    Danofloxacin is a fluoroquinolone developed for use in veterinary medicine. Its concentrations and pharmacokinetic profile in plasma, milk and tissues of lactating dairy cows were determined, and its milk withdrawal time (WT) calculated. Twenty-one dairy cows received a single subcutaneous administration of 18% mesylate danofloxacin salt (6 mg kg -1 ). Plasma and milk samples were obtained at different times until 48 h. Groups of three animals were sacrificed at different post-administration times and tissue samples (mammary gland, uterus, duodenum, jejunum, ileum, colon and mesenteric lymph nodes) obtained. Danofloxacin concentrations were determined by liquid chromatography with fluorescence detection. The milk WT was calculated by the Time to Safe Concentration method (Software WTM 1.4, EMEA). Danofloxacin was rapidly absorbed and its distribution from plasma to all sampled tissues and milk was extensive. Milk and tissues concentrations were several times above those found in plasma. Plasma area under the curve (AUCp) was 9.69 μg h mL -1 and its elimination half life (T β 1/2 ) was 12.53 h. AUC values for the various tissues and milk greatly exceeded AUCp. T β 1/2 from milk and tissues ranged between 4.57 and 21.91 h and the milk withdrawal time was 73.48 h. The reported results support the potential use of danofloxacin in the treatment of mastitis and other infections in milk cows with 3 days of withdrawal

  19. A simple relation for the concentration dependence of osmotic pressure and depletion thickness in polymer solutions

    NARCIS (Netherlands)

    Fleer, G.J.; Skvortsov, A.M.; Tuinier, R.

    2007-01-01

    We propose simple expressions II/IIo = 1 + and (omega/omega(ex))(3 alpha-1) and (delta(0)/delta)(2) = 1 + (omega/omega(ex))(2 alpha) for the osmotic pressure II and the depletion thickness 6 as a function of the polymer concentration omega. Here, IIo and delta 0 correspond to the dilute limit, and

  20. Leucoreduced platelet concentrates in additive solution: an evaluation of filters and storage containers

    NARCIS (Netherlands)

    van der Meer, P.; Pietersz, R.; Reesink, H.

    2001-01-01

    BACKGROUND: AND OBJECTIVE: Buffy coat (BC) pooling sets are integrated systems, consisting of a pooling bag, a filter and a platelet storage container, for the production of leucoreduced platelet concentrates (LR-PCs) from pooled BCs. It was our aim to compare various pooling sets that are currently

  1. New insights into lung diseases using hyperpolarized gas MRI.

    Science.gov (United States)

    Flors, L; Altes, T A; Mugler, J P; de Lange, E E; Miller, G W; Mata, J F; Ruset, I C; Hersman, F W

    2015-01-01

    Hyperpolarized (HP) gases are a new class of contrast agents that permit to obtain high temporal and spatial resolution magnetic resonance images (MRI) of the lung airspaces. HP gas MRI has become important research tool not only for morphological and functional evaluation of normal pulmonary physiology but also for regional quantification of pathologic changes occurring in several lung diseases. The purpose of this work is to provide an introduction to MRI using HP noble gases, describing both the basic principles of the technique and the new information about lung disease provided by clinical studies with this method. The applications of the technique in normal subjects, smoking related lung disease, asthma, and cystic fibrosis are reviewed. Copyright © 2014 SERAM. Published by Elsevier España, S.L.U. All rights reserved.

  2. Feasibility of Topical Applications of Natural High-Concentration Capsaicinoid Solutions in Patients with Peripheral Neuropathic Pain: A Retrospective Analysis

    Directory of Open Access Journals (Sweden)

    Fanny Bauchy

    2016-01-01

    Full Text Available Background. Capsaicin, one of several capsaicinoid compounds, is a potent TRPV1 agonist. Topical application at high concentration (high concentration, >1% induces a reversible disappearance of epidermal free nerve endings and is used to treat peripheral neuropathic pain (PNP. While the benefit of low-concentration capsaicin remains controversial, the 8%-capsaicin patch (Qutenza®, 2010, Astellas, Netherlands has shown its effectiveness. This patch is, however, costly and natural high-concentration capsaicinoid solutions may represent a cheaper alternative to pure capsaicin. Methods. In this retrospective study, 149 patients were screened, 132 were included with a diagnosis of neuropathic pain, and eighty-four were retained in the final analyses (median age: 57.5 years [IQR25–75: 44.7–67.1], male/female: 30/54 with PNP who were treated with topical applications of natural high-concentration capsaicinoid solutions (total number of applications: 137. Indications were postsurgical PNP (85.7% and nonsurgical PNP (14.3% (posttraumatic, HIV-related, postherpetic, and radicular PNP. Objectives. To assess the feasibility of topical applications of natural high-concentration capsaicinoid solutions for the treatment of PNP. Results. The median treated area was 250 cm2 [IQR25–75: 144–531]. The median amount of capsaicinoids was 55.1 mg [IQR25–75: 28.7–76.5] per plaster and the median concentration was 172.3 μg/cm2 [IQR25–75: 127.6–255.2]. Most patients had local adverse effects on the day of treatment, such as mild to moderate burning pain and erythema. 13.6–19.4% of the patients experienced severe pain or erythema. Following treatment, 62.5% of patients reported a lower pain intensity or a smaller pain surface, and 35% reported a sustained pain relief lasting for at least 4 weeks. Conclusion. Analgesic topical treatment with natural high-concentration capsaicinoid is feasible and may represent a low cost alternative to alleviate

  3. Influence of drainage and nutrient-solution nitrogen and potassium concentrations on the agronomic behavior of bell-pepper plants cultivated in a substrate.

    Science.gov (United States)

    Wamser, Anderson Fernando; Cecilio Filho, Arthur Bernardes; Nowaki, Rodrigo Hiyoshi Dalmazzo; Mendoza-Cortez, Juan Waldir; Urrestarazu, Miguel

    2017-01-01

    The interactive effects of N (6, 9, 12 and 15 mmol L-1) and K (3, 5, 7, and 9 mmol L-1) concentrations in nutrient solutions were evaluated on bell pepper grown in a coconut-coir substrate and fertilized without drainage. An additional treatment with drainage was evaluated using N and K concentrations of 12 and 7 mmol L-1, respectively. The hybrid Eppo cultivar of yellow bell pepper was cultivated for 252 days beginning 9 November 2012. Electrical conductivity (EC), the N and K concentrations in the substrate solution, marketable fruit yield, total dry weight and macronutrient concentrations in shoots were periodically evaluated. Fruit production was lower in the system without drainage, regardless of the N and K concentrations, compared to the recommended 10-20% drainage of the volume of nutrient solution applied. Higher K concentrations in the nutrient solution did not affect plant production in the system without drainage for the substrate with an initial K concentration of 331.3 mg L-1. Fruit yield was higher without drainage at a nutrient-solution N concentration of 10.7 mmol L-1. The upper EC limit of the substrate solution in the system without drainage was exceeded 181 days after planting. Either lower nutrient concentrations in the nutrient solution or a drainage system could thus control the EC in the substrate solution.

  4. EXTENDED STORAGE OF BUFFY-COAT PLATELET CONCENTRATES IN PLASMA OR A PLATELET ADDITIVE SOLUTION

    Science.gov (United States)

    Slichter, Sherrill J.; Bolgiano, Doug; Corson, Jill; Jones, Mary Kay; Christoffel, Todd; Bailey, S. Lawrence; Pellham, Esther

    2014-01-01

    Background Platelet concentrates prepared from whole blood in the U.S. are made using the platelet-rich-plasma (PRP) method. The platelet concentrates must be made within 8 hours of blood collection and stored for only 5 days. In Europe and Canada, platelet concentrates are made using the buffy-coat (BC) method from whole blood held overnight at 22°C and storage times may be up to 7 days. Our studies were designed to determine how long BC platelets can be stored in plasma or Plasmalyte while meeting the FDA’s post-storage viability criteria. Study Design, Materials, And Methods Normal subjects donated whole blood that was stored at 22°C for 22 ± 2 hours prior to preparation of BC platelets. Platelets were stored for 5 to 8 days in either plasma or Plasmalyte concentrations of 65% or 80%. Radiolabeled autologous stored versus fresh platelet recoveries and survivals were assessed as well as post-storage in vitro assays. Results BC platelets stored in either plasma or 65% Plasmalyte met FDA post-storage platelet recovery criteria for 7 days but survivals for only 6 days, while storage in 80% Plasmalyte gave very poor results. Both stored platelet recoveries and survivals correlated with the same donor’s fresh results, but the correlation was much stronger between recoveries than survivals. In vitro measures of extent of shape change, morphology score, and pH best predicted post-storage platelet recoveries, while annexin V binding best predicted platelet survivals. Conclusion BC platelets stored in either plasma or 65% Plasmalyte meet FDA’s post-storage viability criteria for 6 days. PMID:24673482

  5. Optimization of moistening solution concentration on xylanase activity in solid state fermentation from oil palm empty fruit bunches

    Science.gov (United States)

    Mardawati, Efri; Parlan; Rialita, Tita; Nurhadi, Bambang

    2018-03-01

    Xylanase is an enzyme used in the industrial world, including food industry. Xylanase can be utilized as a 1,4-β-xylosidic endo-hydrolysis catalyst of xylanase, a hemicellulose component for obtaining a xylose monomer. This study aims to determine the optimum concentration of the fermentation medium using Response Surface Method (RSM) in the production of xylanase enzyme from oil palm empty fruit bunches (OPEFB) through solid state fermentation process. The variables varied in this study used factor A (ammonium sulphate concentration 1.0-2.0 g/L), B (concentration of potassium dihydrogen phosphate 1.5-2.5 g/L) and C (urea concentration 0.2 – 0.5 g/L). The data was analysed by using Design Expert version 10.0.1.0 especially CCD with total 17 running including 3 times replicated of canter point. Trichoderma viride was used for the process production of xylanase enzyme. The ratio between substrate and moistening solution used was 0.63 g / mL with temperature of 32.80C, 60 h incubation time. The analysis of enzyme activity was done by DNS method with 1% xylan as substrate. Analysis of protein content in enzyme was done by Bradford method. The optimum of moistening solution concentration in this fermentation was obtained. They are, the ammonium sulphate concentration of 1.5 g/L, potassium dihydrogen phosphate 2.0 g/L and urea 0.35 g/L with activity of 684.70 U/mL, specific activity enzyme xylanase 6261.58 U/mg, protein content 0.1093 U/mg, the model was validated using experiment design with perfect reliability value 0.96.

  6. The electrochemical corrosion of bulk nanocrystalline ingot iron in HCl solutions with different concentrations

    International Nuclear Information System (INIS)

    Wang, S.G.; Sun, M.; Cheng, P.C.; Long, K.

    2011-01-01

    Highlights: → The corrosion resistance of BNII was enhanced in comparison with CPII in 0.1-0.4 mol L -1 solution. → The function work of BNII is 0.47 eV larger that of CPII. → The energy state density of 4s electrons of BNII is 13.73% less than that of CPII. → BNII corrosion resistance was enhanced due to its larger work function and less 4s electrons weight. → The specific adsorption of Cl - on BNII was weaker than that of CPII due to its larger function work. - Abstract: We studied the corrosion properties of bulk nanocrystalline ingot iron (BNII) and conventional polycrystalline ingot iron (CPII) in HCl solutions from 0.1 mol L -1 to 0.4 mol L -1 at room temperature. The corrosion resistance of BNII was enhanced in comparison with CPII. We investigated the surface energy state densities of BNII and CPII with ultra-violet photoelectron spectroscopy. The energy state density of BNII 4s electrons was 13.73% less than that of CPII. The function work of BNII was 0.47 eV larger that of CPII. The corrosion resistance of BNII was enhanced in comparison with CPII due to its less energy state density of 4s electrons, larger work function and weaker Cl - specific adsorption.

  7. Using MOF-74 for Hg{sup 2+} removal from ultra-low concentration aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Yang Yang; Li, Jian Qiang; Gong, Le Le; Feng, Xue Feng; Meng, Li Na; Zhang, Le; Meng, Pan Pan; Luo, Ming Biao; Luo, Feng, E-mail: ecitluofeng@163.com

    2017-02-15

    Mercury (Hg{sup 2+}) ions have very high toxicity and widely spread as environmental pollutants. At present, many efforts have been taken to remove the hazardous materials of mercury(II) by adsorption, and it is highly desirable to develop a novel adsorbent with high adsorptive capacities. However it is still a big challenge to remove the ultra-low-concentration mercury ions from water. In this paper, MOF-74-Zn is explored for such function, showing high removal rate of Hg(II) from water without any pretreatment, especially for the ultra-trace Hg(II) ions in the ppb magnitude with the removal rate reaching to 54.48%, 69.71%, 72.26% when the initial concentration of Hg(II) is 20ppb, 40ppb, 50ppb, respectively. - Graphical abstract: The absorption of mercury ions on MOF-74-Zn is due to somewhat weak interactions between MOF skeleton that is composed of carboxylate and hydroxy group and Hg2+ ions. - Highlights: • MOF-74-Zn shows high removal rate of Hg(II) from water without any pretreatment. • The MOF-74-Zn has a notable performance at ultra-low concentration of Hg(II). • MOF-74-Zn shows the potential for Hg(II) removal from industrial waste water.

  8. Using MOF-74 for Hg2+ removal from ultra-low concentration aqueous solution

    International Nuclear Information System (INIS)

    Xiong, Yang Yang; Li, Jian Qiang; Gong, Le Le; Feng, Xue Feng; Meng, Li Na; Zhang, Le; Meng, Pan Pan; Luo, Ming Biao; Luo, Feng

    2017-01-01

    Mercury (Hg 2+ ) ions have very high toxicity and widely spread as environmental pollutants. At present, many efforts have been taken to remove the hazardous materials of mercury(II) by adsorption, and it is highly desirable to develop a novel adsorbent with high adsorptive capacities. However it is still a big challenge to remove the ultra-low-concentration mercury ions from water. In this paper, MOF-74-Zn is explored for such function, showing high removal rate of Hg(II) from water without any pretreatment, especially for the ultra-trace Hg(II) ions in the ppb magnitude with the removal rate reaching to 54.48%, 69.71%, 72.26% when the initial concentration of Hg(II) is 20ppb, 40ppb, 50ppb, respectively. - Graphical abstract: The absorption of mercury ions on MOF-74-Zn is due to somewhat weak interactions between MOF skeleton that is composed of carboxylate and hydroxy group and Hg2+ ions. - Highlights: • MOF-74-Zn shows high removal rate of Hg(II) from water without any pretreatment. • The MOF-74-Zn has a notable performance at ultra-low concentration of Hg(II). • MOF-74-Zn shows the potential for Hg(II) removal from industrial waste water.

  9. Pre-concentration and determination of tartrazine dye from aqueous solutions using modified cellulose nanosponges.

    Science.gov (United States)

    Shiralipour, Roohollah; Larki, Arash

    2017-01-01

    In this study, a new absorbent based on cellulose nanosponges modified with methyltrioctylammonium chloride (aliquat 336) was prepared and used for pre-concentration, removal and determination of tartrazine dye, using UV-vis spectrophotometry. This adsorbent was fully characterized using various instrumental techniques such as SEM, FTIR and XRD spectra. The pre-concentration and removal procedures were studied in column and batch modes, respectively. The effects of parameters such as pH of the aqueous medium, methyltrioctylammounium chloride dose, adsorbent amount, desorbing conditions and interfering ions on the adsorption of tartrazine were investigated and optimized. The fitting experimental data with conventional isotherm models revealed that the adsorption followed the Brunauer-Emmett-Teller (BET) model and the maximum adsorption capacity for tartrazine was 180mg/g with modified nanosponges. Under the optimized conditions, the calibration curve was linear over the range of 2-300ng/mL and the limit of detection was 0.15ng/mL. The relative standard deviation (RSD) for 20 and 100ng/mL of tartrazine were 3.1% and 1.5%, respectively. The proposed method was applied for pre-concentration and determination of tartrazine dye in different water samples. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Effect of TCE concentration and dissolved groundwater solutes on NZVI-promoted TCE dechlorination and H2 evolution.

    Science.gov (United States)

    Liu, Yueqiang; Phenrat, Tanapon; Lowry, Gregory V

    2007-11-15

    Nanoscale zero-valent iron (NZVI) is used to remediate contaminated groundwater plumes and contaminant source zones. The target contaminant concentration and groundwater solutes (NO3-, Cl-, HCO3-, SO4(2-), and HPO4(2-)) should affect the NZVI longevity and reactivity with target contaminants, but these effects are not well understood. This study evaluates the effect of trichloroethylene (TCE) concentration and common dissolved groundwater solutes on the rates of NZVI-promoted TCE dechlorination and H2 evolution in batch reactors. Both model systems and real groundwater are evaluated. The TCE reaction rate constant was unaffected by TCE concentration for [TCE] TCE concentration up to water saturation (8.4 mM). For [TCE] > or = 0.46 mM, acetylene formation increased, and the total amount of H2 evolved at the end of the particle reactive lifetime decreased with increasing [TCE], indicating a higher Fe0 utilization efficiency for TCE dechlorination. Common groundwater anions (5mN) had a minor effect on H2 evolution but inhibited TCE reduction up to 7-fold in increasing order of Cl- TCE reduction but increased acetylene production and decreased H2 evolution. NO3- present at > 3 mM slowed TCE dechlorination due to surface passivation. NO3- present at 5 mM stopped TCE dechlorination and H2 evolution after 3 days. Dissolved solutes accounted for the observed decrease of NZVI reactivity for TCE dechlorination in natural groundwater when the total organic content was small (< 1 mg/L).

  11. Hyperpolarized [1-(13) C]pyruvate MRI for noninvasive examination of placental metabolism and nutrient transport: A feasibility study in pregnant guinea pigs.

    Science.gov (United States)

    Friesen-Waldner, Lanette J; Sinclair, Kevin J; Wade, Trevor P; Michael, Banoub; Chen, Albert P; de Vrijer, Barbra; Regnault, Timothy R H; McKenzie, Charles A

    2016-03-01

    To test the feasibility of hyperpolarized [1-(13) C]pyruvate magnetic resonance imaging (MRI) for noninvasive examination of guinea pig fetoplacental metabolism and nutrient transport. Seven pregnant guinea pigs with a total of 30 placentae and fetuses were anesthetized and scanned at 3T. T1 -weighted (1) H images were obtained from the maternal abdomen. An 80 mM solution of hyperpolarized [1-(13) C]pyruvate (hereafter referred to as pyruvate) was injected into a vein in the maternal foot. Time-resolved 3D (13) C images were acquired starting 10 seconds after the beginning of bolus injection and every 10 seconds after to 50 seconds. The pregnant guinea pigs were recovered after imaging. Regions of interest (ROIs) were drawn around the maternal heart and each placenta and fetal liver in all slices in the (1) H images. These ROIs were copied to the (13) C images and were used to calculate the sum of the pyruvate and lactate signal intensities for each organ. The signal intensities were normalized by the volume of the organ and the maximum signal in the maternal heart. No adverse events were observed in the pregnant guinea pigs and natural pupping occurred at term (∼68 days). Pyruvate signal was observed in all 30 placentae, and lactate, a by-product of pyruvate metabolism, was also observed in all placentae. The maximum pyruvate and lactate signals in placentae occurred at 20 seconds. In addition to the observation of pyruvate and lactate signals in the placentae, both pyruvate and lactate signals were observed in all fetal livers. The maximum pyruvate and lactate signals in the fetal livers occurred at 10 seconds and 20 seconds, respectively. This work demonstrates the feasibility of using hyperpolarized [1-(13) C]pyruvate MRI to noninvasively examine fetoplacental metabolism and transport of pyruvate in guinea pigs. Hyperpolarized (13) C MRI may provide a novel method for longitudinal studies of fetoplacental abnormalities. © 2015 Wiley Periodicals, Inc.

  12. Conditioning highly concentrated borate solutions with calcium sulfo-aluminate cement

    International Nuclear Information System (INIS)

    Champenois, J.B.; Cau dit Coumes, C.; Poulesquen, A.; Le Bescop, P.; Damidot, D.

    2012-01-01

    The early age hydration by borate solution of 3 calcium sulfo-aluminate cements (CSA), containing respectively 0%, 10% and 20% of gypsum by weight of cement was studied using isothermal calorimetry and dynamic mode rheo-metry. XRD and TGA analysis were carried out on pastes with increasing hydration degrees (up to 90 days) to specify the mineralogy and to figure out the mechanisms of borate immobilisation. It has been shown that the retarding effect of borate anions is due to the precipitation of the amorphous calcium borate C 2 B 3 H 8 ; borate anions were then incorporated in Aft-type phases. The macroscopic properties of hydrated binders (compressive strength, length change) were also followed during 180 days. It appears that the mechanical strength continuously increases with the hydration degree. Length changes under wet-curing and sealed bag remain moderate and seem to be stabilized after 180 days

  13. Bradsim-prediction of solute concentration. Temperature and physical property profiles along pulsed plate columns

    International Nuclear Information System (INIS)

    Logsdail, D.H.; Evans, S.F.; Jenkins, J.A.; Smith, I.J.

    1988-01-01

    Dynamic model of the operation of the BRADSIM pulsed plate column is developed. Examples of simulation of the pures process extraction system are given. Profiles of dissolved substances concentrations and profiles of physical properties of liquid along the column are provided. Calculated values are compared with the experimental data, obtained in case of the column 50 mm in diameter, Harwell extractional facility and Sellafield pulsed column 300 mm in diameter for extraction systems uranyl nitrate-nitric acid-20% and 30% TBP in kerosene. 2 refs.; 6 figs

  14. Dependence of the concentrations of "1"3"7Cs and potassium in extracted soil solutions on soil humidity before centrifugation

    International Nuclear Information System (INIS)

    Prorok, V.V.; Datsenko, O.Yi.; Bulavyin, L.A.; Zlens'kij, S.Je.; Melnichenko, L.Yu.; Rozuvan, S.G.; Poperenko, L.V.; White, P.J.

    2017-01-01

    Concentrations of 137Cs and potassium in solutions extracted by centrifugation from soils selected at some experimental sites in the 10-km Exclusion Zone of Chornobyl Nuclear Plant were determined. The results showed that for the majority of investigated soils, the concentration of 137Cs in soil solution depends on the humidity of the soil before centrifugation. It is possible to explain the dependence of the concentration of 137Cs in the soil solution on soil humidity from the dependence of the concentrations of molecules of different molecular-gravimetric fractions in soil solution on soil humidity. Considerable amount of 137Cs in soil solution is associated with these molecules, that is why the concentration of 137Cs in the extracted soil solution changes with the humidity of soil. These dependences differ between soils. For the majority of investigated soils the concentration of 137Cs in the extracted soil solution increases with increasing humidity of the soil. By contrast, soil humidity had no effect on the potassium concentration in the extracted soil solution for any soil investigated. It is concluded, that potassium is practically not associated with molecules of different molecular-gravimetric fractions in the extracted soil solutions

  15. CONCENTRATED CALCIUM NITRATE IS AN EFFECTIVE SOLUTION FOR MINERAL NUTRITION OF VEGETABLES GROWN THROUGH PROTECTED CULTIVATION

    Directory of Open Access Journals (Sweden)

    T. V. Grebennikova

    2017-01-01

    Full Text Available One of the basis water-soluble fertilizers that are used in greenhouse enterprises is  a Calcium  nitrate,  where  its production  and demand raise. At present time, calcium nitrate is produced  in a granulated and crystaline   form consisted of tetrahydrate, dihydrate and concentrated variants. These forms  are significantly distinguished  by their  chemical  composition.  Besides the  basic  form  of nitrogen – nitrate – there is ammoniacal nitrogen in the composition of Calcium nitrate that is found to be undesirable element, particularly with drip irrigation system in the  greenhouse. The new  product,  calcium  nitrate  has been worked out with minimal content of ammoniacal nitrogen  at  URALCHIM. The study  showed  the  advantages of the product for such characteristics as solubility and time of dissolving. It dissolves 3.4-7 time faster than those of tetrahydrate and dihydrate analogues. At present time, the concentrated  calcium  nitrate is used in many greenhouse  industrial  complexes  and  enterprises,  and has shown its efficiency in practice.

  16. The development of precisely analytical method for the concentrated boric acid solution in the NPP systems

    Energy Technology Data Exchange (ETDEWEB)

    Sung, G. B.; Jung, K. H.; Kang, D. W. [KEPRI, Taejon (Korea, Republic of); Park, C. S. [KEPCO, Taejon (Korea, Republic of)

    1999-05-01

    Boric acid is used for reactivity control in nuclear reactors, which frequently results in leftover boric acid. This extra boric acid is stored in boric acid storage tank after the concentration process by boric acid evaporator. Apart from this excess, highly concentrated boric acid is stored in safety-related boric acid storage tank. Accordingly, proper maintenance of these boric acid is one of the greatest safety concerns. The solubility of boric acid decreases with decreasing temperature resulting in its precipitation. Consequently, the temperature of boric acid storage tanks is maintained at high temperature. The following analysis should be also performed at the similar temperature to prevent the formation of boric acid precipitation, which is difficult to achieve affecting the accuracy of analytical results. This paper presents a new sampling and measuring technique that makes up for the difficulties mentioned above and shows several advantages including improved reliability and short analysis time. This method is based on gravimetry and dilution method and is expected to be widely used in field application.

  17. Dynamic coronary MR angiography in a pig model with hyperpolarized water

    DEFF Research Database (Denmark)

    Lipsø, Hans Kasper Wigh; Hansen, Esben Søvsø Szocska; Tougaard, Rasmus Stilling

    2018-01-01

    To investigate dynamic coronary MR angiography using hyperpolarized water as a positive contrast agent. Hyperpolarization can increase the signal by several orders of magnitude, and has recently been translated to human cardiac application. The aim was to achieve large 1 H signal enhancement...... to allow high-resolution imaging of the coronary arteries. Protons in D2 O were hyperpolarized by dissolution dynamic nuclear polarization. A total of 18 mL of hyperpolarized water was injected into the coronary arteries of healthy pigs (N = 9; 3 injections in 3 animals). The MRI images were acquired...... with a gradient-echo sequence in an oblique slab covering the main left coronary arteries with 0.55 mm in-plane resolution. The acquisition time was 870 ms per frame. A more than 200-fold signal enhancement compared with thermally polarized water at 3 T was obtained. Coronary angiographic images with a signal...

  18. Design of a 15N Molecular Unit to Achieve Long Retention of Hyperpolarized Spin State

    Science.gov (United States)

    Nonaka, Hiroshi; Hirano, Masashi; Imakura, Yuki; Takakusagi, Yoichi; Ichikawa, Kazuhiro; Sando, Shinsuke

    2017-01-01

    Nuclear hyperpolarization is a phenomenon that can be used to improve the sensitivity of magnetic resonance molecular sensors. However, such sensors typically suffer from short hyperpolarization lifetime. Herein we report that [15N, D14]trimethylphenylammonium (TMPA) has a remarkably long spin-lattice relaxation time (1128 s, 14.1 T, 30 °C, D2O) on its 15N nuclei and achieves a long retention of the hyperpolarized state. [15N, D14]TMPA-based hyperpolarized sensor for carboxylesterase allowed the highly sensitive analysis of enzymatic reaction by 15N NMR for over 40 min in phophate-buffered saline (H2O, pH 7.4, 37 °C).

  19. Hyperpolarized metabolic MR in the study of cardiac function and disease

    DEFF Research Database (Denmark)

    Lauritzen, M. H.; Søgaard, L. V.; Madsen, Pia Lisbeth

    2014-01-01

    Several diseases of the heart have been linked to an insufficient ability to generate enough energy (ATP) to sustain proper heart function. Hyperpolarized magnetic resonance (MR) is a novel technique that can visualize and quantify myocardial energy metabolism. Hyperpolarization enhances the MR...... signal from a biological molecule of interest by more than 10,000 times, making it possible to measure its cellular uptake and conversion in specific enzymatic pathways in real time. We review the role of hyperpolarized MR in identifying changes in cardiac metabolism in vivo, and present the extensive...... literature on hyperpolarized pyruvate that has been used to characterize cardiac disease in various in vivo models, such as myocardial ischemia, hypertension, diabetes, hyperthyroidism and heart failure. The technical aspects of the technique are presented as well as the challenges of translating...

  20. Stress corrosion cracking of X80 pipeline steel exposed to high pH solutions with different concentrations of bicarbonate

    Science.gov (United States)

    Fan, Lin; Du, Cui-wei; Liu, Zhi-yong; Li, Xiao-gang

    2013-07-01

    Susceptibilities to stress corrosion cracking (SCC) of X80 pipeline steel in high pH solutions with various concentrations of HCO{3/-} at a passive potential of -0.2 V vs. SCE were investigated by slow strain rate tensile (SSRT) test. The SCC mechanism and the effect of HCO{3/-} were discussed with the aid of electrochemical techniques. It is indicated that X80 steel shows enhanced susceptibility to SCC with the concentration of HCO{3/-} increasing from 0.15 to 1.00 mol/L, and the susceptibility can be evaluated in terms of current density at -0.2 V vs. SCE. The SCC behavior is controlled by the dissolution-based mechanism in these circumstances. Increasing the concentration of HCO{3/-} not only increases the risk of rupture of passive films but also promotes the anodic dissolution of crack tips. Besides, little susceptibility to SCC is found in dilute solution containing 0.05 mol/L HCO{3/-} for X80 steel. This can be attributed to the inhibited repassivation of passive films, manifesting as a more intensive dissolution in the non-crack tip areas than at the crack tips.

  1. Cryogenics free production of hyperpolarized 129Xe and 83Kr for biomedical MRI applications

    Science.gov (United States)

    Hughes-Riley, Theodore; Six, Joseph S.; Lilburn, David M. L.; Stupic, Karl F.; Dorkes, Alan C.; Shaw, Dominick E.; Pavlovskaya, Galina E.; Meersmann, Thomas

    2013-12-01

    As an alternative to cryogenic gas handling, hyperpolarized (hp) gas mixtures were extracted directly from the spin exchange optical pumping (SEOP) process through expansion followed by compression to ambient pressure for biomedical MRI applications. The omission of cryogenic gas separation generally requires the usage of high xenon or krypton concentrations at low SEOP gas pressures to generate hp 129Xe or hp 83Kr with sufficient MR signal intensity for imaging applications. Two different extraction schemes for the hp gasses were explored with focus on the preservation of the nuclear spin polarization. It was found that an extraction scheme based on an inflatable, pressure controlled balloon is sufficient for hp 129Xe handling, while 83Kr can efficiently be extracted through a single cycle piston pump. The extraction methods were tested for ex vivo MRI applications with excised rat lungs. Precise mixing of the hp gases with oxygen, which may be of interest for potential in vivo applications, was accomplished during the extraction process using a piston pump. The 83Kr bulk gas phase T1 relaxation in the mixtures containing more than approximately 1% O2 was found to be slower than that of 129Xe in corresponding mixtures. The experimental setup also facilitated 129Xe T1 relaxation measurements as a function of O2 concentration within excised lungs.

  2. Cryogenics free production of hyperpolarized 129Xe and 83Kr for biomedical MRI applications☆

    Science.gov (United States)

    Hughes-Riley, Theodore; Six, Joseph S.; Lilburn, David M.L.; Stupic, Karl F.; Dorkes, Alan C.; Shaw, Dominick E.; Pavlovskaya, Galina E.; Meersmann, Thomas

    2013-01-01

    As an alternative to cryogenic gas handling, hyperpolarized (hp) gas mixtures were extracted directly from the spin exchange optical pumping (SEOP) process through expansion followed by compression to ambient pressure for biomedical MRI applications. The omission of cryogenic gas separation generally requires the usage of high xenon or krypton concentrations at low SEOP gas pressures to generate hp 129Xe or hp 83Kr with sufficient MR signal intensity for imaging applications. Two different extraction schemes for the hp gasses were explored with focus on the preservation of the nuclear spin polarization. It was found that an extraction scheme based on an inflatable, pressure controlled balloon is sufficient for hp 129Xe handling, while 83Kr can efficiently be extracted through a single cycle piston pump. The extraction methods were tested for ex vivo MRI applications with excised rat lungs. Precise mixing of the hp gases with oxygen, which may be of interest for potential in vivo applications, was accomplished during the extraction process using a piston pump. The 83Kr bulk gas phase T1 relaxation in the mixtures containing more than approximately 1% O2 was found to be slower than that of 129Xe in corresponding mixtures. The experimental setup also facilitated 129Xe T1 relaxation measurements as a function of O2 concentration within excised lungs. PMID:24135800

  3. NMR study of hyper-polarized 129Xe and applications to liquid-phase NMR experiments

    International Nuclear Information System (INIS)

    Marion, D.

    2008-07-01

    In liquid samples where both nuclear polarization and spin density are strong, the magnetization dynamics, which can be analysed by NMR (nuclear magnetic resonance) methods, is deeply influenced by the internal couplings induced by local dipolar fields. The present thesis describes some of the many consequences associated to the presence in the sample of concentrated xenon hyper-polarized by an optical pumping process. First, we deal with the induced modifications in frequency and line width of the proton and xenon spectra, then we present the results of SPIDER, a coherent polarization transfer experiment designed to enhance the polarization of protons, in order to increase their NMR signal level. A third part is dedicated to the description of the apparition of repeated chaotic maser emissions by un unstable xenon magnetization coupled to the detection coil tuned at the xenon Larmor frequency (here 138 MHz). In the last part, we present a new method allowing a better tuning of any NMR detection probe and resulting in sensible gains in terms of sensitivity and signal shaping. Finally, we conclude with a partial questioning of the classical relaxation theory in the specific field of highly polarized and concentrated spin systems in a liquid phase. (author)

  4. Gamma and x radiation and thermal neutrons effects in lens solutions and the relation with proteins concentration

    International Nuclear Information System (INIS)

    Ramirez A, M.; Alarcon C, A.

    1996-01-01

    Radiation effects have been studied irradiating porcine lens solutions with doses which range between 52 Gy to 1042 Gy in the case of x-rays (30 kVp), 631 Gy to 4001 Gy in the case of 60 Co gamma rays and 314 Gy to 7596 Gy for thermal neutrons. The optics density time variation of solutions was determined using a Spectronic-501 spectrophotometer, and with this data an equation which describes the behavior in the mentioned cases was found. A phenomenological model is postulated which connects the optical time variation density increment macroscopic effect with proteins concentration in the crystalline lens obtaining relative biological effectiveness using the supra-molecular aggregate formation due to the denaturalization and destruction of lens proteins by radiation criteria. (authors). 5 refs., 3 figs

  5. Formulation and make-up of simulated concentrated water, high ionic content aqueous solution

    International Nuclear Information System (INIS)

    Gdowski, G.

    1997-01-01

    This procedure describes the formulation and make-up of Simulated Concentrated Water (SCW), a high-ionic-content water to be used for Activity E-20-50 Long-Term Corrosion Studies. This water has an ionic content which is nominally a factor of a thousand higher than that of representative waters at or near Yucca Mountain. Representative waters were chosen as J-13 well water [Harrar, 1990] and perched water at Yucca Mountain [Glassley, 1996]. J-13 well water is obtained from ground water that is in contact with the Topopah Spring tuff, which is the repository horizon rock. The perched water is located in the Topopah Spring tuff, but below the repository horizon and above the water table. A nominal thousand times higher ionic content was chosen to simulate the water that would result from the wetting of salts which have been previously deposited on a container surface

  6. Hyperpolarized Water Perfusion in the Porcine Brain – a Pilot Study

    DEFF Research Database (Denmark)

    Søvsø Szocska Hansen, Esben; Lipsø, Hans Kasper Wigh; Tougaard, Rasmus Stilling

    2017-01-01

    Dynamic Contrast-Enhanced MR (DCE-MR) perfusion assessment with gadolinium contrast agents is currently the most widely used cerebral perfusion MR method. Hyperpolarized water has recently been shown to succeed 13C probes as angiography probe. In this study, we demonstrate the feasibility...... of hyperpolarized water for visualizing the brain vasculature of a large animal in a clinically relevant setting. In detail, reference perfusion values were obtained and large to small arteries could be identified....

  7. Renal MR angiography and perfusion in the pig using hyperpolarized water

    DEFF Research Database (Denmark)

    Lipsø, Hans Kasper Wigh; Hansen, Esben Søvsø Szocska; Tougaard, Rasmus Stilling

    2016-01-01

    at 3 Tesla (T). Approximately 15 mL of hyperpolar-ized water was injected in the renal artery by hand over 4–5 s.Results: A liquid state polarization of 5.3 6 0.9% of 3.8 M pro-tons in 15 mL of deuterium oxide was achieved with a T1of24 6 1 s. This allowed injection through an arterial catheterinto...

  8. Corrosion of nickel and stainless steels in concentrated lithium hydroxide solutions

    International Nuclear Information System (INIS)

    Graydon, J.W.; Kirk, D.W.

    1990-06-01

    The corrosion behaviour of four alloys in 3 and 5 mol/L lithium hydroxide solutions under a hydrogen atmosphere at 95 degrees C was investigated. Corrosion of Nickel 200 and the stainless steels 316, 316L, and E-Brite 26-1 was assessed in two sets of immersion tests lasting 10 and 136 days. Corrosion rates were determined by weight loss, susceptibility to stress corrosion cracking was evaluated using U-bends, and the details of the corrosion process were studied on specimens with a mirror finish using light and electron microscopy, x-ray spectrometry and mapping, and x-ray diffraction. The long term corrosion rates were low for all alloys ( 2 , β-LiFeO 2 , and a very iron-rich β-LiFe 5 0 8 . The passivating layer on the nickel was Ni(OH) 2 . The underlying metal corroded evenly except for the 316 stainless steels. These showed a uniform intergranular corrosion with minor drop-out of smaller grains likely because of segregation of impurities to the grain boundaries. The walls of these intergranular crevices were covered with a passivating layer of chromium oxide. (8 figs., 5 tabs., 11 refs.)

  9. Solution growth of the Gd-Cu-Al systems in the low-gadolinium concentration range

    International Nuclear Information System (INIS)

    Uhlirova, Klara; Sechovsky, Vladimir

    2009-01-01

    Solution growth of Gd-Cu-Al resulted in the formation of single crystals of GdCu 4 Al 8 with tetragonal ThMn 12 -type structure (a = 8.751 Aa, c = 5.148 Aa), Gd 2 Cu 9.4-6.7 Al 7.6-10.3 with hexagonal Th 2 Zn 17 -type structure (a = 8.83 Aa c = 1.28 Aa), and Gd(Cu, Al) 4 with orthorhombic CeNi 2+x Sb 2-x -type structure. An antiferromagnetic ordering of GdCu 4 Al 8 was found below 35 K, which is in agreement with the previously reported T N = 35 K and T N = 32 K measured on polycrystalline samples. In the temperature range 50-320 K the magnetic susceptibility χ follows the Curie-Weiss law with μ eff = 7.8 μ B /f.u. and θ p = -17 K for B parallel c, μ eff = 7.9 μ B /f.u. and θ p = - 18 K for B perpendicular to c. The a-axis is the easy magnetization direction. The Gd(Cu, Al) 4 and Gd(Cu, Al) 4 compounds order antiferromagnetically below T N = 35 K and T N = 31 K, respectively. (orig.)

  10. Hyperpolarized [U-(2) H, U-(13) C]Glucose reports on glycolytic and pentose phosphate pathway activity in EL4 tumors and glycolytic activity in yeast cells.

    Science.gov (United States)

    Timm, Kerstin N; Hartl, Johannes; Keller, Markus A; Hu, De-En; Kettunen, Mikko I; Rodrigues, Tiago B; Ralser, Markus; Brindle, Kevin M

    2015-12-01

    A resonance at ∼181 ppm in the (13) C spectra of tumors injected with hyperpolarized [U-(2) H, U-(13) C]glucose was assigned to 6-phosphogluconate (6PG), as in previous studies in yeast, whereas in breast cancer cells in vitro this resonance was assigned to 3-phosphoglycerate (3PG). These peak assignments were investigated here using measurements of 6PG and 3PG (13) C-labeling using liquid chromatography tandem mass spectrometry (LC-MS/MS) METHODS: Tumor-bearing mice were injected with (13) C6 glucose and the (13) C-labeled and total 6PG and 3PG concentrations measured. (13) C MR spectra of glucose-6-phosphate dehydrogenase deficient (zwf1Δ) and wild-type yeast were acquired following addition of hyperpolarized [U-(2) H, U-(13) C]glucose and again (13) C-labeled and total 6PG and 3PG were measured by LC-MS/MS RESULTS: Tumor (13) C-6PG was more abundant than (13) C-2PG/3PG and the resonance at ∼181 ppm matched more closely that of 6PG. (13) C MR spectra of wild-type and zwf1Δ yeast cells showed a resonance at ∼181 ppm after labeling with hyperpolarized [U-(2) H, U-(13) C]glucose, however, there was no 6PG in zwf1Δ cells. In the wild-type cells 3PG was approximately four-fold more abundant than 6PG CONCLUSION: The resonance at ∼181 ppm in (13) C MR spectra following injection of hyperpolarized [U-(2) H, U-(13) C]glucose originates predominantly from 6PG in EL4 tumors and 3PG in yeast cells. © 2014 Wiley Periodicals, Inc.

  11. Uncertainty propagation for the coulometric measurement of the plutonium concentration in CRM126 solution provided by JAEA

    Energy Technology Data Exchange (ETDEWEB)

    Morales-Arteaga, Maria [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-11-07

    This GUM WorkbenchTM propagation of uncertainty is for the coulometric measurement of the plutonium concentration in a Pu standard material (C126) supplied as individual aliquots that were prepared by mass. The C126 solution had been prepared and as aliquoted as standard material. Samples are aliquoted into glass vials and heated to dryness for distribution as dried nitrate. The individual plutonium aliquots were not separated chemically or otherwise purified prior to measurement by coulometry in the F/H Laboratory. Hydrogen peroxide was used for valence adjustment.

  12. Characterization of the deviation to the ideality of concentrated actinide and lanthanide salt solutions: contribution of the Bimsa theory

    International Nuclear Information System (INIS)

    Ruas, A.

    2006-03-01

    The aim of this work is to describe the mean stoichiometric activity coefficients, osmotic coefficients or water activities of aqueous actinide nitrate salt solutions up to high concentration. These sets of data are required for a better control of the equilibria occurring in liquid-liquid extraction processes. Experimental acquisition of these thermodynamic properties, in the case of some actinide nitrates, is possible and was conducted before.But, many actinide salt solutions cannot be experimentally handled up to high concentration because of unstable oxidation state or very high radioactivity. As a consequence, a suitable predictive theory is necessary for the description of these nitrate salt solutions (such as Am (NO 3 ) 3 , Cm (NO 3 ) 3 ). The BIMSA ('Binding Mean Spherical Approximation') was chosen for this purpose. This theory, unlike other methods, uses a set of microscopic parameters that have some physical meaning, for the description of macroscopic thermodynamic properties (osmotic coefficients, activity coefficients).The following manuscript is divided by 4 chapters, corresponding to 4 articles accepted in the scientific journal 'Journal of Physical Chemistry'. Chapter 1 first reviews the basic thermodynamic concepts before describing the issues involved in acquiring actinides binary data. An approach based on the thermodynamic concept of simple solutions, the notion of fictive binary data, is described. Within this approach, the activity coefficient of an aqueous phase constituent depends on two parameters: the water activity of the system and total concentration of dissolved constituents. As a first application, new fictive binary data of uranyl nitrate are proposed from measurements on the ternary system UO 2 (NO 3 ) 2 /HNO 3 /H 2 O.Chapter 2 gives the main principles of the BIMSA theory. It shows also preliminary promising results obtained when modeling lanthanide(III) salt properties. Then, in chapter 3, two predictive capabilities of the theory

  13. Sustainable Solution for Crude Oil and Natural Gas Separation using Concentrated Solar Power Technology

    Science.gov (United States)

    Choudhary, Piyush; Srivastava, Rakesh K.; Nath Mahendra, Som; Motahhir, Saad

    2017-08-01

    In today’s scenario to combat with climate change effects, there are a lot of reasons why we all should use renewable energy sources instead of fossil fuels. Solar energy is one of the best options based on features like good for the environment, independent of electricity prices, underutilized land, grid security, sustainable growth, etc. This concept paper is oriented primarily focused on the use of Solar Energy for the crude oil heating purpose besides other many prospective industrial applications to reduce cost, carbon footprint and moving towards a sustainable and ecologically friendly Oil & Gas Industry. Concentrated Solar Power technology based prototype system is proposed to substitute the presently used system based on natural gas burning method. The hybrid system which utilizes the solar energy in the oil and gas industry would strengthen the overall field working conditions, safety measures and environmental ecology. 40% reduction on natural gas with this hybrid system is estimated. A positive implication for an environment, working conditions and safety precautions is the additive advantage. There could also decrease air venting of CO2, CH4 and N2O by an average of 30-35%.

  14. Macroscopic observation of thermal behavior of concentrated solution of coal extracts

    Energy Technology Data Exchange (ETDEWEB)

    Masao Suzuki; Koyo Norinaga; Masashi Iino [Tohoku University, Sendai (Japan). Institute of Multidisciplinary Research for Advanced Materials

    2004-11-01

    The solvent extracts of Upper Freeport and Illinois No.6 coals were mixed with N-methyl-2-pyrolidinone (NMP) and annealed at 353 K to produce the gelatinous materials. Differential scanning calorimetric measurements revealed that the materials can hold significant amounts of nonfreezable NMP (as much as 3 g NMP per 1 g coal extracts) which disperse in the materials on a molecular scale, indicating the materials are not phase separated. The thermal behaviors were measured macroscopically as a function of the extract concentration using a needle penetrometer during heating from 223 to 360 K. The penetration-temperature curves were analyzed to estimate the apparent viscosity ({eta}{sub a}). During the penetrations, {eta}{sub a} was decreased very rapidly, approximately four orders of the magnitude by a temperature increase of 20 K, suggesting that the coal extracts-NMP mixtures undergoes a gel to sol transition. The heats of dissociation of crosslinks ({Delta}H{sub m}) were estimated by applying Eldridge-Ferry equation. The {Delta}H{sub m} of coal extracts-NMP mixtures was relatively small, i.e. approximately 10 kJ/mol, whereas the ?Hm of polyvinyl alcohol-NMP gel in which the hydrogen bonds contribute the formation of the physical network structures, was about 65 kJ/mol. Not the specific interaction such as hydrogen bonds, but weak interactions such as van der Waals force were likely to contribute the formation of the coal extracts-NMP gel. 28 refs., 7 figs., 2 tabs.

  15. [Computer modeling the dependences of the membrane potential for polymeric membrane separated non-homogeneous electrolyte solutions on concentration Rayleigh number].

    Science.gov (United States)

    Slezak, Izabella H; Jasik-Slezak, Jolanta; Bilewicz-Wyrozumska, Teresa; Slezak, Andrzej

    2006-01-01

    On the basis of model equation describing the membrane potential delta psi(s) on concentration Rayleigh number (R(C)), mechanical pressure difference (deltaP), concentration polarization coefficient (zeta s) and ratio concentration of solutions separated by membrane (Ch/Cl), the characteristics delta psi(s) = f(Rc)(delta P, zeta s, Ch/Cl) for steady values of zeta s, R(C) and Ch/Cl in single-membrane system were calculated. In this system neutral and isotropic polymeric membrane oriented in horizontal plane, the non-homogeneous binary electrolytic solutions of various concentrations were separated. Nonhomogeneity of solutions is results from creations of the concentration boundary layers on both sides of the membrane. Calculations were made for the case where on a one side of the membrane aqueous solution of NaCl at steady concentration 10(-3) mol x l(-1) (Cl) was placed and on the other aqueous solutions of NaCl at concentrations from 10(-3) mol x l(-1) to 2 x 10(-2) mol x l(-1) (Ch). Their densities were greater than NaCl solution's at 10(-3) mol x l(-1). It was shown that membrane potential depends on hydrodynamic state of a complex concentration boundary layer-membrane-concentration boundary layer, what is controlled by deltaP, Ch/Cl, Rc and Zeta(s).

  16. Aqueous dispersion polymerization: a new paradigm for in situ block copolymer self-assembly in concentrated solution.

    Science.gov (United States)

    Sugihara, Shinji; Blanazs, Adam; Armes, Steven P; Ryan, Anthony J; Lewis, Andrew L

    2011-10-05

    Reversible addition-fragmentation chain transfer polymerization has been utilized to polymerize 2-hydroxypropyl methacrylate (HPMA) using a water-soluble macromolecular chain transfer agent based on poly(2-(methacryloyloxy)ethylphosphorylcholine) (PMPC). A detailed phase diagram has been elucidated for this aqueous dispersion polymerization formulation that reliably predicts the precise block compositions associated with well-defined particle morphologies (i.e., pure phases). Unlike the ad hoc approaches described in the literature, this strategy enables the facile, efficient, and reproducible preparation of diblock copolymer spheres, worms, or vesicles directly in concentrated aqueous solution. Chain extension of the highly hydrated zwitterionic PMPC block with HPMA in water at 70 °C produces a hydrophobic poly(2-hydroxypropyl methacrylate) (PHPMA) block, which drives in situ self-assembly to form well-defined diblock copolymer spheres, worms, or vesicles. The final particle morphology obtained at full monomer conversion is dictated by (i) the target degree of polymerization of the PHPMA block and (ii) the total solids concentration at which the HPMA polymerization is conducted. Moreover, if the targeted diblock copolymer composition corresponds to vesicle phase space at full monomer conversion, the in situ particle morphology evolves from spheres to worms to vesicles during the in situ polymerization of HPMA. In the case of PMPC(25)-PHPMA(400) particles, this systematic approach allows the direct, reproducible, and highly efficient preparation of either block copolymer vesicles at up to 25% solids or well-defined worms at 16-25% solids in aqueous solution.

  17. Isotope dilution alpha spectrometry for the determination of plutonium concentration in irradiated fuel dissolver solution : IDAS and R-IDAS

    International Nuclear Information System (INIS)

    Ramaniah, M.V.; Jain, H.C.; Aggarwal, S.K.; Chitambar, S.A.; Kavimandan, V.D.; Almaula, A.I.; Shah, P.M.; Parab, A.R.; Sant, V.L.

    1980-01-01

    The report presents a new technique, Isotope Dilution Alpha Spectrometry (IDAS) and Reverse Isotope Dilution Alpha Spectrometry (R-IDAS) for determining the concentration of plutonium in the irradiated fuel dissolver solution. The method exploits sup(238)Pu in IDAS and sup(239)Pu in R-IDAS as a spike and provides an alternative method to Isotope Dilution Mass Spectrometry (IDMS) which requires enriched sup(242)Pu as a spike. Depending upon the burn-up of the fuel, sup(238)Pu or sup(239)Pu is used as a spike to change the sup(238)Pu/(sup(239)Pu+sup(240)Pu)α activity ratio in the sample by a factor of 10. This change is determined by α-spectrometry on electrodeposited sources using a solid state silicon surface barrier detector coupled to a multichannel analyser. The validity of a simple method based on the geometric progression (G.P.) decrease for the far tail of the spectrum to correct for the tail contribution of sup(238)Pu peak (5.50 MeV) to the low energy sup(239)Pu + sup(240)Pu peak (5.17 MeV) is established. Results for the plutonium concentration on different irradiated fuel dissolver solutions with burn-uo ranging from J,000 to 100,000 MWD/TU are presented and compared with those obtained by IDMS. The values obtained by IDAS or R-IDAS and IDMS agree within 0.5%. (auth.)

  18. Effects of gamma radiation on phase behaviour and critical micelle concentration of Triton X-100 aqueous solutions

    International Nuclear Information System (INIS)

    Valdes Diaz, G.; Rodriguez-Calvo, S.; Perez-Gramatges, A.; Rapado-Paneque, M.; Fernandez-Lima, F. A.; Ponciano, C. R.; Silveira, E. F. . E-mail. apgram@instec.cu

    2007-01-01

    Ionising radiation used for sterilisation can have an effect on the physico-chemical properties of pharmaceutically relevant excipient systems, affecting therefore the stability of the formulation. The effect of gamma irradiation on the phase behaviour (cloud point - CP) and critical micelle concentration (CMC) of aqueous solutions of Triton X-100, used as a model nonionic surfactant, is investigated in this paper. Micellar solutions irradiated with ?-rays in a dose range between 0 and 70 kGy, including the sterilisation range of pharmaceutical preparations, were analysed using mass spectrometry. Results show a slight shift in molecular mass distribution of ethoxylated surfactant, which indicates degradation of polyethoxylated chains by water radical attacks. This fact, combined with the formation of cross-linked species, is considered to be responsible for the decrease observed in CP and CMC values of micellar solutions at all absorbed doses. There is no spectroscopic evidence of radiation damage to aromatic ring or hydrocarbon tail of surfactant. Models based on Flory-Huggins theory were employed to estimate CP from changes in mass distribution and to obtain cross-linking fractions. (Author)

  19. Electrical properties of (1 0 0)-predominant BaTiO3 films derived from alkoxide solutions of two concentrations

    International Nuclear Information System (INIS)

    Guo Yiping; Suzuki, Kazuyuki; Nishizawa, Kaori; Miki, Takeshi; Kato, Kazumi

    2006-01-01

    Lead-free piezoelectric films with thickness larger than 1 μm integrated on silicon substrates have been receiving considerable attention because of environmental concerns and their potential applications in microelectromechanical systems. We demonstrate that, by chemical solution deposition, it is possible to process (1 0 0)-predominant 1 μm BaTiO 3 films on LaNiO 3 /Pt/TiO x /SiO 2 /Si substrates using thinner high-crystallinity columnar BaTiO 3 films as buffer layers. We point out that this kind of buffer layer prepared with a lower concentration solution on the surface of an LaNiO 3 /Pt electrode is effective in enhancing the crystallinity and orientation degree of final BaTiO 3 films prepared with a higher concentration solution. The 1 μm BaTiO 3 films show good dielectric and insulating characteristics against an applied field, and the conduction current shows Schottky emission behavior at modest voltage and space-charge-limited behavior at higher voltage. We also demonstrate that the (1 0 0)-predominant 1 μm BaTiO 3 films have excellent piezoelectric properties: piezoelectric coefficients d 33 higher than 50 pm/V have been determined for the bare films using atomic force microscopy, which are comparable to those of Pb(Zr,Ti)O 3 films. These results indicate that the (1 0 0)-predominant BaTiO 3 films should be promising candidates for microelectromechanical systems applications

  20. On the Control of Solute Mass Fluxes and Concentrations Below Fields Irrigated With Low-Quality Water: A Numerical Study

    Science.gov (United States)

    Russo, David

    2017-11-01

    The main goal of this study was to test the capability of irrigation water-based and soil-based approaches to control nitrate and chloride mass fluxes and concentrations below the root zone of agricultural fields irrigated with treated waste water (TWW). Using numerical simulations of flow and transport in relatively a fine-textured, unsaturated, spatially heterogeneous, flow domain, scenarios examined include: (i) irrigating with TWW only (REF); (ii) irrigation water is substituted between TWW and desalinized water (ADW); (iii) soil includes a capillary barrier (CB) and irrigating with TWW only (CB + TWW); and (iv) combination of (ii) and a CB (CB + ADW). Considering groundwater quality protection, plausible goals are: (i) to minimize solute discharges leaving the root zone, and, (ii) to maximize the probability that solute concentrations leaving the root zone will not exceed a prescribed, critical value. Results of the analyses suggest that in the case of a seasonal crop (a corn field) subject to irrigations only, with respect to the first goal, the CB + TWW and CB + ADW scenarios provide similar, excellent results, better than the ADW scenario; with respect to the second goal, however, the CB + ADW scenario gave substantially better results than the CB + TWW scenario. In the case a multiyear, perennial crop (a citrus orchard), subject to a sequence of irrigation and rainfall periods, for both solutes, and, particularly, nitrate, with respect to the two goals, both the ADW and CB + ADW scenarios perform better than the CB + TWW scenario. As compared with the REF and CB + TWW scenarios, the ADW and CB + ADW scenarios substantially reduce nitrogen mass fluxes to the groundwater and to the atmosphere, and, essentially, did not reduce nitrogen mass fluxes to the trees. Similar results, even better, were demonstrated for a relatively coarse-textured, spatially heterogeneous soil.

  1. X-radiation effect on the hyperpolarization of cells, the adeninenucleotide content and the distribution of sodium and potassium ions

    Energy Technology Data Exchange (ETDEWEB)

    Frol' kis, V V [Akademiya Meditsinskikh Nauk Ukrainskoj SSR, Kiev. Inst. Gerontologii

    1975-03-01

    X-radiation prevents the progress of hyperpolarization of muscle and liver cells caused by hormones (estradioldipropyonate, deoxycorticosteron-acetate and insulin) and by the loss of blood. X-radiation offsets the redistribution of K/sup +/ and Na/sup +/ ions caused by hyperpolarization and does not change the level of ATP, ADP, CP and Pi. X-radiation is suggested to affect the hyperpolarization and the ionic shifts via the system of protein biosynthesis.

  2. Impact of soil properties on critical concentrations of cadmium, lead, copper, zinc, and mercury in soil and soil solution in view of ecotoxicological effects.

    Science.gov (United States)

    de Vries, Wim; Lofts, Steve; Tipping, Ed; Meili, Markus; Groenenberg, Jan E; Schütze, Gudrun

    2007-01-01

    Risk assessment for metals in terrestrial ecosystems, including assessments of critical loads, requires appropriate critical limits for metal concentrations in soil and soil solution. This chapter presents an overview of methodologies used to derive critical (i) reactive and total metal concentrations in soils and (ii) free metal ion and total metal concentrations in soil solution for Cd, Pb, Cu, Zn, and Hg, taking into account the effect of soil properties related to ecotoxicological effects. Most emphasis is given to the derivation of critical free and total metal concentrations in soil solution, using available NOEC soil data and transfer functions relating solid-phase and dissolved metal concentrations. This approach is based on the assumption that impacts on test organisms (plants, microorganisms, and soil invertebrates) are mainly related to the soil solution concentration (activity) and not to the soil solid-phase content. Critical Cd, Pb, Cu, Zn, and Hg concentrations in soil solution vary with pH and DOC level. The results obtained are generally comparable to those derived for surface waters based on impacts to aquatic organisms. Critical soil metal concentrations, related to the derived soil solution limits, can be described as a function of pH and organic matter and clay content, and varying about one order of magnitude between different soil types.

  3. Solute concentration at a well in non-Gaussian aquifers under constant and time-varying pumping schedule

    Science.gov (United States)

    Libera, Arianna; de Barros, Felipe P. J.; Riva, Monica; Guadagnini, Alberto

    2017-10-01

    Our study is keyed to the analysis of the interplay between engineering factors (i.e., transient pumping rates versus less realistic but commonly analyzed uniform extraction rates) and the heterogeneous structure of the aquifer (as expressed by the probability distribution characterizing transmissivity) on contaminant transport. We explore the joint influence of diverse (a) groundwater pumping schedules (constant and variable in time) and (b) representations of the stochastic heterogeneous transmissivity (T) field on temporal histories of solute concentrations observed at an extraction well. The stochastic nature of T is rendered by modeling its natural logarithm, Y = ln T, through a typical Gaussian representation and the recently introduced Generalized sub-Gaussian (GSG) model. The latter has the unique property to embed scale-dependent non-Gaussian features of the main statistics of Y and its (spatial) increments, which have been documented in a variety of studies. We rely on numerical Monte Carlo simulations and compute the temporal evolution at the well of low order moments of the solute concentration (C), as well as statistics of the peak concentration (Cp), identified as the environmental performance metric of interest in this study. We show that the pumping schedule strongly affects the pattern of the temporal evolution of the first two statistical moments of C, regardless the nature (Gaussian or non-Gaussian) of the underlying Y field, whereas the latter quantitatively influences their magnitude. Our results show that uncertainty associated with C and Cp estimates is larger when operating under a transient extraction scheme than under the action of a uniform withdrawal schedule. The probability density function (PDF) of Cp displays a long positive tail in the presence of time-varying pumping schedule. All these aspects are magnified in the presence of non-Gaussian Y fields. Additionally, the PDF of Cp displays a bimodal shape for all types of pumping

  4. Pathway to cryogen free production of hyperpolarized Krypton-83 and Xenon-129.

    Directory of Open Access Journals (Sweden)

    Joseph S Six

    Full Text Available Hyperpolarized (hp (129Xe and hp (83Kr for magnetic resonance imaging (MRI are typically obtained through spin-exchange optical pumping (SEOP in gas mixtures with dilute concentrations of the respective noble gas. The usage of dilute noble gases mixtures requires cryogenic gas separation after SEOP, a step that makes clinical and preclinical applications of hp (129Xe MRI cumbersome. For hp (83Kr MRI, cryogenic concentration is not practical due to depolarization that is caused by quadrupolar relaxation in the condensed phase. In this work, the concept of stopped flow SEOP with concentrated noble gas mixtures at low pressures was explored using a laser with 23.3 W of output power and 0.25 nm linewidth. For (129Xe SEOP without cryogenic separation, the highest obtained MR signal intensity from the hp xenon-nitrogen gas mixture was equivalent to that arising from 15.5±1.9% spin polarized (129Xe in pure xenon gas. The production rate of the hp gas mixture, measured at 298 K, was 1.8 cm(3/min. For hp (83Kr, the equivalent of 4.4±0.5% spin polarization in pure krypton at a production rate of 2 cm(3/min was produced. The general dependency of spin polarization upon gas pressure obtained in stopped flow SEOP is reported for various noble gas concentrations. Aspects of SEOP specific to the two noble gas isotopes are discussed and compared with current theoretical opinions. A non-linear pressure broadening of the Rb D(1 transition was observed and taken into account for the qualitative description of the SEOP process.

  5. Pathway to cryogen free production of hyperpolarized Krypton-83 and Xenon-129.

    Science.gov (United States)

    Six, Joseph S; Hughes-Riley, Theodore; Stupic, Karl F; Pavlovskaya, Galina E; Meersmann, Thomas

    2012-01-01

    Hyperpolarized (hp) (129)Xe and hp (83)Kr for magnetic resonance imaging (MRI) are typically obtained through spin-exchange optical pumping (SEOP) in gas mixtures with dilute concentrations of the respective noble gas. The usage of dilute noble gases mixtures requires cryogenic gas separation after SEOP, a step that makes clinical and preclinical applications of hp (129)Xe MRI cumbersome. For hp (83)Kr MRI, cryogenic concentration is not practical due to depolarization that is caused by quadrupolar relaxation in the condensed phase. In this work, the concept of stopped flow SEOP with concentrated noble gas mixtures at low pressures was explored using a laser with 23.3 W of output power and 0.25 nm linewidth. For (129)Xe SEOP without cryogenic separation, the highest obtained MR signal intensity from the hp xenon-nitrogen gas mixture was equivalent to that arising from 15.5±1.9% spin polarized (129)Xe in pure xenon gas. The production rate of the hp gas mixture, measured at 298 K, was 1.8 cm(3)/min. For hp (83)Kr, the equivalent of 4.4±0.5% spin polarization in pure krypton at a production rate of 2 cm(3)/min was produced. The general dependency of spin polarization upon gas pressure obtained in stopped flow SEOP is reported for various noble gas concentrations. Aspects of SEOP specific to the two noble gas isotopes are discussed and compared with current theoretical opinions. A non-linear pressure broadening of the Rb D(1) transition was observed and taken into account for the qualitative description of the SEOP process.

  6. Determination of semi-empirical relationship between the manganese and hydrogen atoms ratio, physical density and concentration in an aqueous solution of manganese sulphate

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues Bittencourt, Guilherme, E-mail: bittencourt@ird.gov.b [Instituto de Radioprotecao e Dosimetria LNMRI/IRD/CNEN, Av. Salvador Allende, s/n Recreio dos Bandeirantes, CEP 22780-160, Rio de Janeiro, RJ (Brazil); Souza Patrao, Karla Cristina de, E-mail: karla@ird.gov.b [Instituto de Radioprotecao e Dosimetria LNMRI/IRD/CNEN, Av. Salvador Allende, s/n Recreio dos Bandeirantes, CEP 22780-160, Rio de Janeiro, RJ (Brazil); Passos Leite, Sandro, E-mail: sandro@ird.gov.b [Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Caixa Postal 68509, 21945-970, Rio de Janeiro, RJ (Brazil); Wagner Pereira, Walsan, E-mail: walsan@ird.gov.b [Instituto de Radioprotecao e Dosimetria LNMRI/IRD/CNEN, Av. Salvador Allende, s/n Recreio dos Bandeirantes, CEP 22780-160, Rio de Janeiro, RJ (Brazil); Simoes da Fonseca, Evaldo, E-mail: evaldo@ird.gov.b [Instituto de Radioprotecao e Dosimetria LNMRI/IRD/CNEN, Av. Salvador Allende, s/n Recreio dos Bandeirantes, CEP 22780-160, Rio de Janeiro, RJ (Brazil)

    2010-12-15

    The Manganese sulphate solution has been used for neutron metrology through the method of Manganese Bath. This method uses physical parameters of manganese sulphate solution to obtain its corrections. This work established a functional relationship, using the gravimetric method, between those physical parameters: density, concentration and hydrogen to manganese ratio. Comparisons were done between manganese sulphate solution concentration from the Manganese Bath system of Laboratory of Metrology of Ionising Radiation and estimated values from the functional relationship obtained, showing percentage difference of less than 0.1%. This result demonstrates the usefulness in the correlation of the physical values of the solution to the MB.

  7. Detection of tobacco smoke deposition by hyperpolarized krypton-83 MRI.

    Science.gov (United States)

    Cleveland, Zackary I; Pavlovskaya, Galina E; Stupic, Karl F; Wooten, Jan B; Repine, John E; Meersmann, Thomas

    2008-02-01

    Despite the importance of the tobacco smoke particulate matter in the lungs to the etiology of pulmonary disease in cigarette smokers, little is currently known about the spatial distribution of particle deposition or the persistence of the resulting deposits in humans, and no satisfactory technique currently exists to directly observe tobacco smoke condensate in airways. In this proof-of-principle work, hyperpolarized (hp) 83Kr MRI and NMR spectroscopy are introduced as probes for tobacco smoke deposition in porous media. A reduction in the hp-83Kr longitudinal (T1) relaxation of up to 95% under near-ambient humidity, pressure and temperature conditions was observed when the krypton gas was brought into contact with surfaces that had been exposed to cigarette smoke. This smoke-induced acceleration of the 83Kr self-relaxation was observed for model glass surfaces that, in some experiments, were coated with bovine lung surfactant extract. However, a similar effect was not observed with hp-(129)Xe indicating that the 83Kr sensitivity to smoke deposition was not caused by paramagnetic species but rather by quadrupolar relaxation due to high adsorption affinity for the smoke deposits. The 83Kr T1 differences between smoke-treated and untreated surfaces were sufficient to produce a strong contrast in variable flip angle FLASH hp-83Kr MRI, suggesting that hp-83Kr may be a promising contrast agent for in vivo pulmonary MRI.

  8. Validating excised rodent lungs for functional hyperpolarized xenon-129 MRI.

    Directory of Open Access Journals (Sweden)

    David M L Lilburn

    Full Text Available Ex vivo rodent lung models are explored for physiological measurements of respiratory function with hyperpolarized (hp (129Xe MRI. It is shown that excised lung models allow for simplification of the technical challenges involved and provide valuable physiological insights that are not feasible using in vivo MRI protocols. A custom designed breathing apparatus enables MR images of gas distribution on increasing ventilation volumes of actively inhaled hp (129Xe. Straightforward hp (129Xe MRI protocols provide residual lung volume (RV data and permit for spatially resolved tracking of small hp (129Xe probe volumes during the inhalation cycle. Hp (129Xe MRI of lung function in the excised organ demonstrates the persistence of post mortem airway responsiveness to intravenous methacholine challenges. The presented methodology enables physiology of lung function in health and disease without additional regulatory approval requirements and reduces the technical and logistical challenges with hp gas MRI experiments. The post mortem lung functional data can augment histological measurements and should be of interest for drug development studies.

  9. Study of the transport characteristics of uranyl chloride in a highly concentrated aqueous solution of sodium chloride

    International Nuclear Information System (INIS)

    Murso, H.

    1986-01-01

    The purpose of this work was the study of the transport processes of uranyl chloride at various temperatures, in order to be able to estimate the danger potential of the intrusion of water during storage in salt form. For this the concentration dependency of the approximated principal diffusion coefficients of uranyl chloride in a table salt solution, which with a c(NaCl) = 5.2 mol/l is almost at the saturation point, was studied at 25, 40 and 50degC. The measurements were successful in the ternarian system UO 2 Cl 2 -NaCl-H 2 O with absorption optics. An unexpected temperature dependency of the diffusion coefficients was found, which reached its minimum at 40degC with UO 2 Cl 2 concentrations of less than 2x10 -2 mol/l. For comparison the diffusion coefficients were measured in the binary system UO 2 Cl 2 -H 2 O and compared with theoretical calculations. The cause for the poor correlation found here is thought to be the hydrolysis products, whose formation is strongly influenced by the foreign-electrolyte concentration (NaCl). For clarification, viscosity measurements and molar mass determinations (ultracentrifuge) will be done. Some pH-dependent hydrolysis equilibriums are being postulated and the equilibrium constants of uranyl hydroxo complexes are being determined by sedimentation analysis. (orig./RB) [de

  10. The effect of stocking rate on soil solution nitrate concentrations beneath a free-draining dairy production system in Ireland.

    Science.gov (United States)

    McCarthy, J; Delaby, L; Hennessy, D; McCarthy, B; Ryan, W; Pierce, K M; Brennan, A; Horan, B

    2015-06-01

    Economically viable and productive farming systems are required to meet the growing worldwide need for agricultural produce while at the same time reducing environmental impact. Within grazing systems of animal production, increasing concern exists as to the effect of intensive farming on potential N losses to ground and surface waters, which demands an appraisal of N flows within complete grass-based dairy farming systems. A 3-yr (2011 to 2013) whole-farm system study was conducted on a free-draining soil type that is highly susceptible to N loss under temperate maritime conditions. Soil solution concentrations of N from 3 spring-calving, grass-based systems designed to represent 3 alternative whole-farm stocking rate (SR) treatments in a post-milk quota situation in the European Union were compared: low (2.51 cows/ha), medium (2.92 cows/ha), and high SR (3.28 cows/ha). Each SR had its own farmlet containing 18 paddocks and 23 cows. Nitrogen loss from each treatment was measured using ceramic cups installed to a depth of 1m to sample the soil water. The annual and monthly average nitrate, nitrite, ammonia, and total N concentrations in soil solution collected were analyzed for each year using a repeated measures analysis. Subsequently, and based on the biological data collated from each farm system treatment within each year, the efficiency of N use was evaluated using an N balance model. Based on similar N inputs, increasing SR resulted in increased grazing efficiency and milk production per hectare. Stocking rate had no significant effect on soil solution concentrations of nitrate, nitrite, ammonia, or total N (26.0, 0.2, 2.4, and 32.3 mg/L, respectively). An N balance model evaluation of each treatment incorporating input and output data indicated that the increased grass utilization and milk production per hectare at higher SR resulted in a reduction in N surplus and increased N use efficiency. The results highlight the possibility for the sustainable

  11. Investigation of electrochemical synthesis of ferrate, Part I: Electrochemical behavior of iron and its several alloys in concentrated alkaline solutions

    Directory of Open Access Journals (Sweden)

    Čekerevac Milan I.

    2009-01-01

    Full Text Available In recent years, considerable attention has been paid to various applications of Fe(VI due to its unique properties such as oxidizing power, selective reactivity, stability of the salt, and non-toxic decomposition by-products of ferric ion. In environmental remediation processes, Fe(VI has been proposed as green oxidant, coagulant, disinfectant, and antifoulant. Therefore, it is considered as a promising multi-purpose water treatment chemical. Fe(VI has also potential applications in electrochemical energy source, as 'green cathode'. The effectiveness of ferrate as a powerful oxidant in the entire pH range, and its use in environmental applications for the removal of wide range of contaminants has been well documented by several researchers. There is scientific evidence that ferrate can effectively remove arsenic, algae, viruses, pharmaceutical waste, and other toxic heavy metals. Although Fe(VI was first discovered in early eighteen century, detailed studies on physical and chemical properties of Fe(VI had to wait until efficient synthetic and analytical methods of Fe(VI were developed by Schreyer et al. in the 1950s. Actually, there have been developed three ways for the preparation of Fe(VI compounds : the wet oxidation of Fe(II and Fe(III compounds, the dry oxidation of the same, and the electrochemistry method, mainly based on the trans passive oxidation of iron. High purity ferrates Fe(VI can be generated when electrode of the pure iron metal or its alloys are anodized in concentrated alkaline solution. It is known that the efficiency of electrochemical process of Fe(VI production depends on many factors such as current density, composition of anode material, types of electrolyte etc. In this paper, the electrochemical synthesis of ferrate(VI solution by the anodic dissolution of iron and its alloys in concentrated water solution of NaOH and KOH is investigated. The process of transpassive dissolution of iron to ferrate(VI was studied by

  12. Determination of free acid in highly concentrated organic and aqueous solutions of plutonium (IV) and uranium (VI) nitrate

    International Nuclear Information System (INIS)

    Wagner, J.F.; Lacour, J.L.

    1989-01-01

    Free acidity is an important parameter in the nuclear reprocessing control. The accuracy on the determination of free acidity is not really required in the nuclear reprocessing control itself but is necessary for certain types of analysis such as spectrophotometry (Pu (VI), Am (III),...), density determinations. A new titripotentiometric method for free acidity determination in concentrated U(VI) and Pu(IV) solutions is presented. This method is based on the complexing properties of dipicolinic acid (pyridine 2.6 dicarboxylic acid) and medium effect with H 2 O/DMSO mixture. This method can be used either in organic or aqueous phases with ratio /H + I/ metal ≥ 5.10 -2 and a relative standard deviation of 1%

  13. Effect of phosphorus concentration of the nutrient solution on the volatile constituents of leaves and bracts of Origanum dictamnus.

    Science.gov (United States)

    Economakis, C; Skaltsa, Helen; Demetzos, Costas; Soković, M; Thanos, Costas A

    2002-10-23

    The chemical composition of the essential oils obtained from the leaves and bracts of hydroponically cultivated Origanum dictamnus were analyzed by GC-MS techniques. Three different concentrations of phosphorus (5, 30, and 60 mg/L) in the nutrient solution were used for the cultivation, using the nutrient film technique (NFT). A total of 46 different compounds were identified and significant differences (qualitative and quantitative) were observed between the samples. Carvacrol and p-cymene were identified as the main compounds in all samples analyzed, whereas thymoquinone was found in higher percentage in the leaves than in bracts. The essential oils were tested for their antibacterial activity against Gram-positive and Gram-negative bacteria. The oils obtained from the bracts were found to be more active. The results obtained from GC-MS analyses were submitted to chemometric analysis.

  14. Effect of increasing concentrations of lead, cadmium, chromium, nickel, or zinc on lettuce grown in nutrient solution

    Energy Technology Data Exchange (ETDEWEB)

    Foroughi, M.; Hoffmann, G.; Teicher, K.; Venter, F.

    1975-01-01

    Experiments were performed to examine concentrations at which excess symptoms could be expected, which kind of damage symptoms appear and in which amount the heavy metals are enriched in roots and leaves. The following results were revealed. Lettuce (Lactuca sativa L. var. capitata L.) can tolerate amounts of Cd below 1 ppm, of Ni below 2 ppm and of Pb below 20 ppm in the nutrient solution without any symptoms of excess. The growth of lettuce was mostly influenced by Cd, least of all by Pb. Only Ni caused specific poisoning symptoms. Heavy metals were enriched in different amounts in roots and leaves. The contents of Cd and Ni were more than twice as high as those of Pb. The heavy metals influenced the uptake and distribution of macro-elements more (nitrogen) or less (potassium) vigorously.

  15. Specific features of concentrated phase under decomposition of weak solid /sup 3/He-/sup 4/He solution

    Energy Technology Data Exchange (ETDEWEB)

    Mikheev, V A; Majdamov, V A; Kal' noj, S E; Omelaenko, N I

    1988-06-01

    The decomposition of solid /sup 3/He-/sup 4/He solutuions is studied on the samples 0.54% /sup 3/He(V=20.55 cm/sup 3//mole) and 0.60% /sup 4/He (V=24.04-24.93 cm/sup 3//mole) using pulse NMR method. At T=100 mK the decomposition of a weak solution proceeds more than for 30 h, the decomposition rate and temperature being dependent on the sample prehistory. In the concentrated phase of the decomposed weak solution the spin diffraction of /sup 3/He is of the quasi-one-dimensional character with the diffusion coefficient D /similar to/ 10/sup -5/ cm/sup 2//sec typical of liquid /sup 3/He and exceeding that bulk solid /sup 3/He by two orders of magnitude. The longitudinal relaxation time in the quasi-one-dimensional phase (/similar to/ 1 sec) is characteristic of the solid state and coinsides with data for bulk /sup 3/He. The temperature behaviour of magnetization in the quasi-one-dimensional phase is well described by the Curie law.

  16. Extraction of soil solution by drainage centrifugation—effects of centrifugal force and time of centrifugation on soil moisture recovery and solute concentration in soil moisture of loess subsoils

    NARCIS (Netherlands)

    Fraters, D.; Boom, G.J.F.L.; Boumans, L.J.M.; Weerd, H. de; Wolters, M.

    2017-01-01

    The solute concentration in the subsoil beneath the root zone is an important parameter for leaching assessment. Drainage centrifugation is considered a simple and straightforward method of determining soil solution chemistry. Although several studies have been carried out to determine whether this

  17. The Effect of Potassium Concentration in Nutrient Solution on Lycopene, Vitamin C and Qualitative Characteristics of Cherry Tomato in Saline Conditions

    Directory of Open Access Journals (Sweden)

    E. Shabani Sangtarashani

    2013-06-01

    Full Text Available Potassium (K has a special place in improving the quality of agricultural products. To evaluate the effect of K concentration in nutrient solution on lycopene content, vitamin C and qualitative characteristics of cherry tomato in NaCl salinity conditions, an experiment was carried out as a completely randomized design with five treatments and three replications at university of Tabriz, Tabriz, Iran, in 2010. Treatments consisted of four concentrations of K (0.2, 2, 7 and 14 mM in nutrient solution with 60 mM NaCl concentration. A nutrient solution treatment without salinity was considered as control. The experiment was conducted in greenhouse, in a hydroponic system. The results indicated that increasing of K concentration increased lycopene content in fruit. Lycopene content in control treatment showed significant difference (P<0.01 in comparison with salinity treatments. With increasing the K concentration (except at 14 mM concentration, vitamin C content was increased, but indicated no statistically significant difference. Vitamin C content in saline conditions was more than control treatment, but showed no significant difference. Adding potassium concentration in nutrient solution improved yield and enhanced quality parameters such as percentage of dry matter, soluble solids and electrical conductivity of fruit extract. Since in saline conditions, the qualitative characteristics of tomato at 7 mM concentration were in the best situation, therefore using this concentration is recommended.

  18. Dry matter and nitrogen accumulation are not affected by superoptimal concentration of ammonium in flowing solution culture with pH control

    Science.gov (United States)

    Rideout, J. W.; Raper, C. D. Jr; Raper CD, J. r. (Principal Investigator)

    1994-01-01

    While it is known that superoptimal concentrations of the nitrate (NO3-) ion in solution culture do not increase NO3- uptake or dry matter accumulation, the same is not known for the ammonium (NH4+) ion. An experiment was conducted utilizing flowing solution culture with pH control to investigate the influence of superoptimal NH4+ concentrations on dry matter, nitrogen (N), potassium (K), calcium (Ca), and magnesium (Mg) accumulation by nonnodulated soybean plants. Increasing the NH4+ concentration in solution from 1 to 10 mM did not affect dry matter or N accumulation. Accumulations of K, Ca, and Mg were slightly decreased with increased NH4+ concentration. The NH4+ uptake system, which is saturated at less than 1mM NH4+, is able to regulate uptake of NH4+ at concentrations as high as 10 mM.

  19. A space-charge treatment of the increased concentration of reactive species at the surface of a ceria solid solution

    Energy Technology Data Exchange (ETDEWEB)

    Zurhelle, Alexander F.; Souza, Roger A. de [Institute of Physical Chemistry, RWTH Aachen University (Germany); Tong, Xiaorui; Mebane, David S. [Department of Mechanical and Aerospace Engineering, West Virginia University, Morgantown, WV (United States); Klein, Andreas [Institute of Materials Science, TU Darmstadt (Germany)

    2017-11-13

    A space-charge theory applicable to concentrated solid solutions (Poisson-Cahn theory) was applied to describe quantitatively as a function of temperature and oxygen partial pressure published data obtained by in situ X-ray photoelectron spectroscopy (XPS) for the concentration of Ce{sup 3+} (the reactive species) at the surface of the oxide catalyst Ce{sub 0.8}Sm{sub 0.2}O{sub 1.9}. In contrast to previous theoretical treatments, these calculations clearly indicate that the surface is positively charged and compensated by an attendant negative space-charge zone. The high space-charge potential that develops at the surface (>0.8 V) is demonstrated to be hardly detectable by XPS measurements because of the short extent of the space-charge layer. This approach emphasizes the need to take into account defect interactions and to allow deviations from local charge neutrality when considering the surfaces of oxide catalysts. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Influence of the current density on the electrochemical treatment of concentrated 1-butyl-3-methylimidazolium chloride solutions on diamond electrodes.

    Science.gov (United States)

    Marcionilio, Suzana M L de Oliveira; Alves, Gisele M; E Silva, Rachel B Góes; Marques, Pablo J Lima; Maia, Poliana D; Neto, Brenno A D; Linares, José J

    2016-10-01

    This paper focuses on the influence of the current density treatment of a concentrated 1-butyl-3-methylimidazolium chloride (BMImCl) solution on an electrochemical reactor with a boron-doped diamond (BDD) anode. The decrease in the total organic carbon (TOC) and the BMImCl concentration demonstrate the capability of BDD in oxidizing ionic liquids (ILs) and further mineralizing (to CO2 and NO3 (-)) more rapidly at higher current densities in spite of the reduced current efficiency of the process. Moreover, the presence of Cl(-) led to the formation of oxychlorinated anions (mostly ClO3 (-) and ClO4 (-)) and, in combination with the ammonia generated in the cathode from the nitrate reduction, chloramines, more intensely at higher current density. Finally, the analysis of the intermediates formed revealed no apparent influence of the current density on the BMImCl degradation mechanism. The current density presents therefore a complex influence on the IL treatment process that is discussed throughout this paper.

  1. Self-consistent field theoretic simulations of amphiphilic triblock copolymer solutions: Polymer concentration and chain length effects

    Directory of Open Access Journals (Sweden)

    X.-G. Han

    2014-06-01

    Full Text Available Using the self-consistent field lattice model, polymer concentration φP and chain length N (keeping the length ratio of hydrophobic to hydrophilic blocks constant the effects on temperature-dependent behavior of micelles are studied, in amphiphilic symmetric ABA triblock copolymer solutions. When chain length is increased, at fixed φP, micelles occur at higher temperature. The variations of average volume fraction of stickers φcos and the lattice site numbers Ncols at the micellar cores with temperature are dependent on N and φP, which demonstrates that the aggregation of micelles depends on N and φP. Moreover, when φP is increased, firstly a peak appears on the curve of specific heat CV for unimer-micelle transition, and then in addition a primary peak, the secondary peak, which results from the remicellization, is observed on the curve of CV. For a long chain, in intermediate and high concentration regimes, the shape of specific heat peak markedly changes, and the peak tends to be a more broad peak. Finally, the aggregation behavior of micelles is explained by the aggregation way of amphiphilic triblock copolymer. The obtained results are helpful in understanding the micellar aggregation process.

  2. Viscosity of concentrated solutions and of human erythrocyte cytoplasm determined from NMR measurement of molecular correlation times

    International Nuclear Information System (INIS)

    Endre, Z.H.; Kuchel, P.W.

    1986-01-01

    Metabolically active human erythrocytes were incubated with [α- 13 C]glycine which led to the specific enrichment of intracellular glutathione. The cells were then studied using 13 C-NMR in which the longitudinal relaxation times (T 1 ) and nuclear Overhauser enhancements of the free glycine and glutathione were measured. Bulk viscosities of the erythrocyte cytoplasm were measured using Ostwald capillary viscometry. Large differences existed between the latter viscosity estimates and those based upon NMR-T 1 measurements. The authors derived an equation from the theory of the viscosity of concentrated solutions which contains two phenomenological interaction parameters, a 'shape' factor and a 'volume' factor; it was fitted to data relating to the concentration dependence of viscosity measured by both methods. Under various conditions of extracellular osmotic pressure, erythrocytes change volume and thus the viscosity of the intracellular milieu is altered. The volume changes resulted in changes in the T 1 of [α- 13 C]glycine. Conversely, the authors showed that alterations in T 1 , when appropriately calibrated, could be used for monitoring changes in volume of metabolically active cells. (Auth.)

  3. [Optimization of benzalkonium chloride concentration in 0.0015% tafluprost ophthalmic solution from the points of ocular surface safety and preservative efficacy].

    Science.gov (United States)

    Asada, Hiroyuki; Takaoka-Shichijo, Yuko; Nakamura, Masatsugu; Kimura, Akio

    2010-06-01

    Optimization of benzalkonium chloride (alkyl dimethylbenzylammonium chloride: BAK) concentration as preservative in 0.0015% tafluprost ophthalmic solution (Tapros 0.0015% ophthalmic solution), an anti-glaucoma medicine, was examined from the points of ocular surface safety and preservative efficacy. BAKC(12), which is dodecyl dimethylbenzylammonium chloride, and BAKmix, which is the mixture of dodecyl, tetradecyl and hexadecyl dimethylbenzylammonium chloride were used in this study. The effects of BAKC(12) concentrations and the BAK types, BAKC(12) and BAKmix, in tafluprost ophthalmic solution on ocular surface safety were evaluated using the in vitro SV 40-immobilized human corneal epithelium cell line (HCE-T). Following treatments of Tafluprost ophthalmic solutions with BAKC(12), its concentration dependency was observed on cell viability of HCE-T. The cell viability of HCE-T after treatment of these solutions with 0.001% to 0.003% BAKC(12) for 5 minutes were the same level as that after treatment of the solution without BAK. Tafluprost ophthalmic solution with 0.01% BAKC(12) was safer for the ocular surface than the same solution with 0.01% BAKmix. Preservatives-effectiveness tests of tafluprost ophthalmic solutions with various concentrations of BAKC(12) were performed according to the Japanese Pharmacopoeia (JP), and solutions with more than 0.0005% BAKC(12) conformed to JP criteria. It was concluded that 0.0005% to 0.003% of BAKC(12) in tafluprost ophthalmic solution was optimal, namely, well-balanced from the points of ocular surface safety and preservative efficacy.

  4. [Serial change of perilymphatic potassium ion concentration in the scala tympani after introducing KCl-solution into the guinea pigs' tympanic cavity].

    Science.gov (United States)

    Ikeno, K

    1990-09-01

    Characteristic nystagmus similar to the Meniere's attack could be observed after introducing KCl solution into the tympanic cavity of guinea pigs. To confirm the fact that this nystagmus was provoked by the high perilymphatic potassium ion concentration, the K+ activity of perilymph was recorded serially through the K+ specific microelectrode inserted into the scala tympani. The rapid increment of K+ activity reached maximum at 120 minutes after introducing KCl solution, and then it decreased gradually to a half of the maximum activity. However, such change of perilymphatic potassium ion concentration was not observed by introducing sucrose solution as control.

  5. Washout and non-washout solutions of a system describing microbial fermentation process under the influence of growth inhibitions and maximal concentration of yeast cells.

    Science.gov (United States)

    Kasbawati; Gunawan, Agus Yodi; Sidarto, Kuntjoro Adjie

    2017-07-01

    An unstructured model for the growth of yeast cell on glucose due to growth inhibitions by substrate, products, and cell density is discussed. The proposed model describes the dynamical behavior of fermentation system that shows multiple steady states for a certain regime of operating parameters such as inlet glucose and dilution rate. Two types of steady state solutions are found, namely washout and non-washout solutions. Furthermore, different numerical impositions to the two parameters put in evidence three results regarding non-washout solution: a unique locally stable non-washout solution, a unique locally stable non-washout solution towards which other nearby solutions exhibit damped oscillations, and multiple non-washout solutions where one is locally stable while the other is unstable. It is also found an optimal inlet glucose which produces the highest cell and ethanol concentration. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Hyperpolarized Porous Silicon Nanoparticles: Potential Theragnostic Material for ²⁹Si Magnetic Resonance Imaging.

    Science.gov (United States)

    Seo, Hyeonglim; Choi, Ikjang; Whiting, Nicholas; Hu, Jingzhe; Luu, Quy Son; Pudakalakatti, Shivanand; McCowan, Caitlin; Kim, Yaewon; Zacharias, Niki; Lee, Seunghyun; Bhattacharya, Pratip; Lee, Youngbok

    2018-05-20

    Porous silicon nanoparticles have recently garnered attention as potentially-promising biomedical platforms for drug delivery and medical diagnostics. Here, we demonstrate porous silicon nanoparticles as contrast agents for ²⁹Si magnetic resonance imaging. Size-controlled porous silicon nanoparticles were synthesized by magnesiothermic reduction of silica nanoparticles and were surface activated for further functionalization. Particles were hyperpolarized via dynamic nuclear polarization to enhance their ²⁹Si MR signals; the particles demonstrated long ²⁹Si spin-lattice relaxation (T₁) times (~ 25 mins), which suggests potential applicability for medical imaging. Furthermore, ²⁹Si hyperpolarization levels were sufficient to allow ²⁹Si MRI in phantoms. These results underscore the potential of porous silicon nanoparticles that, when combined with hyperpolarized magnetic resonance imaging, can be a powerful theragnostic deep tissue imaging platform to interrogate various biomolecular processes in vivo. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Modeling non-linear kinetics of hyperpolarized [1-(13)C] pyruvate in the crystalloid-perfused rat heart

    NARCIS (Netherlands)

    Mariotti, E.; Orton, M. R.; Eerbeek, O.; Ashruf, J. F.; Zuurbier, C. J.; Southworth, R.; Eykyn, T. R.

    2016-01-01

    Hyperpolarized (13)C MR measurements have the potential to display non-linear kinetics. We have developed an approach to describe possible non-first-order kinetics of hyperpolarized [1-(13)C] pyruvate employing a system of differential equations that agrees with the principle of conservation of mass

  8. Extraction of soil solution by drainage centrifugation-effects of centrifugal force and time of centrifugation on soil moisture recovery and solute concentration in soil moisture of loess subsoils.

    Science.gov (United States)

    Fraters, Dico; Boom, Gerard J F L; Boumans, Leo J M; de Weerd, Henk; Wolters, Monique

    2017-02-01

    The solute concentration in the subsoil beneath the root zone is an important parameter for leaching assessment. Drainage centrifugation is considered a simple and straightforward method of determining soil solution chemistry. Although several studies have been carried out to determine whether this method is robust, hardly any results are available for loess subsoils. To study the effect of centrifugation conditions on soil moisture recovery and solute concentration, we sampled the subsoil (1.5-3.0 m depth) at commercial farms in the loess region of the Netherlands. The effect of time (20, 35, 60, 120 and 240 min) on recovery was studied at two levels of the relative centrifugal force (733 and 6597g). The effect of force on recovery was studied by centrifugation for 35 min at 117, 264, 733, 2932, 6597 and 14,191g. All soil moisture samples were chemically analysed. This study shows that drainage centrifugation offers a robust, reproducible and standardised way for determining solute concentrations in mobile soil moisture in silt loam subsoils. The centrifugal force, rather than centrifugation time, has a major effect on recovery. The maximum recovery for silt loams at field capacity is about 40%. Concentrations of most solutes are fairly constant with an increasing recovery, as most solutes, including nitrate, did not show a change in concentration with an increasing recovery.

  9. Morphological and Structural Analysis of Nano-hydroxyapatite (n-hap) Coatings Electrodeposited on Titanium Substrate : Effect of Deposition Solution Concentration

    International Nuclear Information System (INIS)

    Nik Norziehana Che Isa; Norjanah Yury; Yusairie Mohd

    2011-01-01

    Various concentration of deposition solutions containing CaCl 2 and NH 4 H 2 PO 4 (with Ca/P ratio equal to 1.67) were used to study the effect of deposition solution concentration on the surface morphology and structure of Hydroxyapatite (HAp) coatings. Each HAp coating was deposited onto Ti substrate by applying a constant potential of 1.5 V (vs Ag/ AgCl) at 80 degree Celsius. The formation of HAp coatings was confirmed by FTIR and XRD analyses. Various morphologies consisting of HAp nanoparticles were produced from different deposition solutions as observed by SEM. The concentration of deposition solution has significantly affected the morphology of n-HAp coatings. (author)

  10. Plant induced changes in concentrations of caesium, strontium and uranium in soil solution with reference to major ions and dissolved organic matter

    International Nuclear Information System (INIS)

    Takeda, Akira; Tsukada, Hirofumi; Takaku, Yuichi; Akata, Naofumi; Hisamatsu, Shun'ichi

    2008-01-01

    For a better understanding of the soil-to-plant transfer of radionuclides, their behavior in the soil solution should be elucidated, especially at the interface between plant roots and soil particles, where conditions differ greatly from the bulk soil because of plant activity. This study determined the concentration of stable Cs and Sr, and U in the soil solution, under plant growing conditions. The leafy vegetable komatsuna (Brassica rapa L.) was cultivated for 26 days in pots, where the rhizosphere soil was separated from the non-rhizosphere soil by a nylon net screen. The concentrations of Cs and Sr in the rhizosphere soil solution decreased with time, and were controlled by K + NH 4 + and Ca, respectively. On the other hand, the concentration of U in the rhizosphere soil solution increased with time, and was related to the changes of DOC; however, this relationship was different between the rhizosphere and non-rhizosphere soil

  11. Plant induced changes in concentrations of caesium, strontium and uranium in soil solution with reference to major ions and dissolved organic matter.

    Science.gov (United States)

    Takeda, Akira; Tsukada, Hirofumi; Takaku, Yuichi; Akata, Naofumi; Hisamatsu, Shun'ichi

    2008-06-01

    For a better understanding of the soil-to-plant transfer of radionuclides, their behavior in the soil solution should be elucidated, especially at the interface between plant roots and soil particles, where conditions differ greatly from the bulk soil because of plant activity. This study determined the concentration of stable Cs and Sr, and U in the soil solution, under plant growing conditions. The leafy vegetable komatsuna (Brassica rapa L.) was cultivated for 26 days in pots, where the rhizosphere soil was separated from the non-rhizosphere soil by a nylon net screen. The concentrations of Cs and Sr in the rhizosphere soil solution decreased with time, and were controlled by K+NH(4)(+) and Ca, respectively. On the other hand, the concentration of U in the rhizosphere soil solution increased with time, and was related to the changes of DOC; however, this relationship was different between the rhizosphere and non-rhizosphere soil.

  12. Metabolic Imaging of Patients with Prostate Cancer Using Hyperpolarized [1-13C]Pyruvate

    Science.gov (United States)

    Nelson, Sarah J.; Kurhanewicz, John; Vigneron, Daniel B.; Larson, Peder E. Z.; Harzstark, Andrea L.; Ferrone, Marcus; van Criekinge, Mark; Chang, Jose W.; Bok, Robert; Park, Ilwoo; Reed, Galen; Carvajal, Lucas; Small, Eric J.; Munster, Pamela; Weinberg, Vivian K.; Ardenkjaer-Larsen, Jan Henrik; Chen, Albert P.; Hurd, Ralph E.; Odegardstuen, Liv-Ingrid; Robb, Fraser J.; Tropp, James; Murray, Jonathan A.

    2014-01-01

    This first-in-man imaging study evaluated the safety and feasibility of hyperpolarized [1-13C]pyruvate as an agent for noninvasively characterizing alterations in tumor metabolism for patients with prostate cancer. Imaging living systems with hyperpolarized agents can result in more than 10,000-fold enhancement in signal relative to conventional magnetic resonance (MR) imaging. When combined with the rapid acquisition of in vivo 13C MR data, it is possible to evaluate the distribution of agents such as [1-13C]pyruvate and its metabolic products lactate, alanine, and bicarbonate in a matter of seconds. Preclinical studies in cancer models have detected elevated levels of hyperpolarized [1-13C]lactate in tumor, with the ratio of [1-13C]lactate/[1-13C]pyruvate being increased in high-grade tumors and decreased after successful treatment. Translation of this technology into humans was achieved by modifying the instrument that generates the hyperpolarized agent, constructing specialized radio frequency coils to detect 13C nuclei, and developing new pulse sequences to efficiently capture the signal. The study population comprised patients with biopsy-proven prostate cancer, with 31 subjects being injected with hyperpolarized [1-13C]pyruvate. The median time to deliver the agent was 66 s, and uptake was observed about 20 s after injection. No dose-limiting toxicities were observed, and the highest dose (0.43 ml/kg of 230 mM agent) gave the best signal-to-noise ratio for hyperpolarized [1-13C]pyruvate. The results were extremely promising in not only confirming the safety of the agent but also showing elevated [1-13C]lactate/[1-13C]pyruvate in regions of biopsy-proven cancer. These findings will be valuable for noninvasive cancer diagnosis and treatment monitoring in future clinical trials. PMID:23946197

  13. MR imaging of the stomach and relaxation measurement with intraluminal hyperpolarized 129Xenon gas

    International Nuclear Information System (INIS)

    Yanagawa, Yasuhiro; Kimura, Atsuomi; Fujiwara, Hideaki; Kinoshita, Yoshimasa; Hattori, Mineyuki; Hiraga, Takashi; Iida, Hidehiro

    2001-01-01

    Using laser optical pumping, the nuclear spin polarization of noble gases can be strongly enhanced. The purpose of this study was to make a simple apparatus that can provide hyperpolarized 129 Xe gas, which can then be used in an attempt to obtain magnetic resonance imaging (MRI). We would also like to study the relaxation behavior of hyperpolarized 129 Xe gas through the measurement of the relaxation time. First, we demonstrated that hyperpolarized 129 Xe gas can be applied to magnetic resonance imaging of the stomach, by using a rat as a model. This was performed under a 4.7 T magnet field using the following imaging parameters for the hyperpolarized 129 Xe gas: TR=50 ms, TE=15 ms, FOV=10 x 10 cm 2 , matrix size 64 x 64, THK=2.54 cm. By using these parameters, we were able to obtain a hyperpolarized image of the stomach in rats for the first time. Next, we measured the relaxation times of the hyperpolarized 129 Xe gas enclosed in cavities such as the stomach of rats as well as in phantoms created by glass and gelatin bulbs. The cavity size dependency of the relaxation time was analyzed on the basis of the kinetic theory of gases. This analysis showed a linear relationship between the relaxation rate (1/T 1 ) and a square inverse of the cavity diameter (1/d 2 ). From this relationship, the wall effect on the 129 Xe relaxation can be estimated in the novel parameter t 1 , wall . This shows drastic dependency on the material of the wall, suggesting a potential use of the relaxation experiment as a diagnostic tool for organ surfaces in the future. (author)

  14. An intercomparison experiment on isotope dilution thermal ionisation mass spectrometry using plutonium-239 spike for the determination of plutonium concentration in dissolver solution of irradiated fuel

    International Nuclear Information System (INIS)

    Aggarwal, S.K.; Shah, P.M.; Saxena, M.K.; Jain, H.C.; Gurba, P.B.; Babbar, R.K.; Udagatti, S.V.; Moorthy, A.D.; Singh, R.K.; Bajpai, D.D.

    1996-01-01

    Determination of plutonium concentration in the dissolver solution of irradiated fuel is one of the key measurements in the nuclear fuel cycle. This report presents the results of an intercomparison experiment performed between Fuel Chemistry Division (FCD) at BARC and PREFRE, Tarapur for determining plutonium concentration in dissolver solution of irradiated fuel using 239 Pu spike in isotope dilution thermal ionisation mass spectrometry (ID-TIMS). The 239 Pu spike method was previously established at FCD as viable alternative to the imported enriched 242 Pu or 244 Pu; the spike used internationally for plutonium concentration determination by IDMS in dissolver solution of irradiated fuel. Precision and accuracy achievable for determining plutonium concentration are compared under the laboratory and the plant conditions using 239 Pu spike in IDMS. For this purpose, two different dissolver solutions with 240 Pu/ 239 Pu atom ratios of about 0.3 and 0.07 corresponding, respectively, to high and low burn-up fuels, were used. The results of the intercomparison experiment demonstrate that there is no difference in the precision values obtained under the laboratory and the plant conditions; with mean precision values of better than 0.2%. Further, the plutonium concentration values determined by the two laboratories agreed within 0.3%. This exercise, therefore, demonstrates that ID-TIMS method using 239 Pu spike can be used for determining plutonium concentration in dissolver solution of irradiated fuel, under the plant conditions. 7 refs., 8 tabs

  15. The extraction of zinc and other minor metals from concentrated ammonium chloride solutions with D2EHPA and Cyanex 272

    Directory of Open Access Journals (Sweden)

    Amer, S.

    1995-12-01

    Full Text Available A comparative study is made of the extractants D2EHPA and Cyanex 272 for the zinc and minor metal extraction from aqueous concentrated ammonium chloride solutions, as those of the leaching liquors of the CENIM-LNETI process. Extraction equilibrium data for zinc are presented as extraction isotherms at constant pH and at a temperature of 50 °C. Zinc extraction and coextraction of minor metal ions as Cu, Ca, Pb, Mg, Cd, Co, Ni and Hg are studied. Mercury does not extract from concentrated ammonium chloride solutions. Cyanex 272 shows a better selectivity for zinc with regard to the minor metals than D2EHPA, which is especially remarkable for calcium, the most coextracted element by D2EHPA. Nickel and cadmium coextraction is negligible for both extractants. The possible use of the Cyanex 272 as an alternative to D2EHPA is considered.

    Se realiza un estudio comparativo del comportamiento del D2EHPA y del Cyanex 272 durante la extracción del cinc y otros metales minoritarios de soluciones acuosas concentradas de cloruro amónico, como las de las soluciones de lixiviación del proceso CENIM-LNETI. Se presentan los datos de equilibrio de extracción del cinc en forma de isotermas de extracción a una temperatura de 50 °C y pH constante y se estudia la coextracción de los metales minoritarios Cu, Ca, Pb, Mg, Cd, Co, Ni y Hg. El mercurio no se extrae de las soluciones concentradas de cloruro amónico. La selectividad del Cyanex 272 para el cinc respecto de esos metales minoritarios es mejor que la del D2EHPA, siendo verdaderamente notable para el calcio, que es la impureza que más se coextrae con el D2EHPA. La coextracción de níquel y de cadmio es muy pequeña para ambos extractantes. Se considera la posibilidad del uso alternativo del Cyanex 272 en lugar del D2EHPA.

  16. Studies on the concentration dependence of specific rotation of Alpha lactose monohydrate (α-LM) aqueous solutions and growth of α-LM single crystals

    Science.gov (United States)

    Vinodhini, K.; Divya Bharathi, R.; Srinivasan, K.

    2018-02-01

    Lactose is an optically active substance. As it is one of the reducing sugars, exhibits mutarotation in solution when it dissolves in any solvent. In solution, lactose exists in two isomeric forms, alpha-Lactose (α-L) and beta-lactose (β-L) through the mutarotation reaction. Mutarotation produces a dynamic equilibrium between two isomers in a solution and kinetics of this process determines the growth rate of alpha lactose monohydrate (α-LM) crystals. Since no data were available on the specific rotation of aqueous α-LM solutions at different concentrations at 33 °C, the initial experiments were carried out on the specific rotation of aqueous α-LM solutions at different concentrations at 33 °C. The specific rotations of the solutions were decreased with increasing time through the mutarotation reaction. The initial and final (equilibrium) specific rotations of the solutions were determined by using automatic digital polarimeter. The compositions of α and β-L in all prepared solutions were calculated from initial and final optical rotations by the method of Sharp and Doob. The composition of α-L decreased whereas, the composition of β-L increased in solutions with increasing concentration of α-LM at 33 °C. Experimental results revealed that this method could be easily and safely employed to study the dependence of specific rotation of solutions on their concentration. The effect of β-lactose on the morphology of nucleated α-LM single crystals has been studied at different experimental conditions.

  17. The vapour pressure of water as a function of solute concentration above aqueous solutions of fructose, sucrose, raffinose, erythritol, xylitol, and sorbitol

    DEFF Research Database (Denmark)

    Cooke, S.A.; Jonsdottir, Svava Osk; Westh, Peter

    2002-01-01

    The vapour pressure of water above an aqueous solution of sucrose at T = 298.06 K has been measured for 9 sucrose mole fractions up to 0.12. Vapour pressure measurements have also been made on aqueous solutions of meso-erythritol, xylitol, sorbitol, fructose, and raffinose at T = 317.99 K...

  18. Physical interactions of hyperpolarized gas in the lung

    Science.gov (United States)

    Chen, Xiu-Hao Josette

    1999-09-01

    This thesis addresses key interactions of hyperpolarized (HP) gas within the biological environment of the lung using magnetic resonance imaging (MRI). The first excised lung image was obtained in 1994 by Albert et al ., indicating the relative youth of the HP gas MRI field. Thus, there are a multitude of parameters which need to be explored to optimize contrast mechanisms and pulse sequences for in vivo applications. To perform HP gas MRI, both the production of HP gas and development of appropriate MRI pulse sequences were necessary. The apparatus for gas polarization was transferred from Princeton University, then modified and optimized to provide larger quantities and higher polarizations. It was ultimately replaced by a prototype commercial apparatus. Existing MRI pulse sequences were changed to accommodate and exploit the unique situation of non-equilibrium polarized gas. Several physical parameters of the gas relating to structure and function in the lung were investigated. It was found that using a range of excitation powers, acquisition windows, and ventilatory cycle segments yielded dramatically different types of images in the guinea pig. Spatially localized lineshapes of HP 3He showed differentiated peaks (corresponding to frequency shifts) which represent gas in major airways (2 ppm) and alveoli (1-2 ppm). Quantitative maps of the diffusion coefficient (D) showed evidence of free diffusion in the trachea (average of 2.4 cm2/s for 3He and 0.68 cm2/s for 129Xe) and restricted diffusion combined with effects of gas mixtures in the distal pulmonary airspaces (average of 0.16 cm2/s for 3He and 0.021 cm2/s for 129Xe). Experimental measurements were verified with gas mixture and porous media theory for both 3He and 129Xe. The dephasing parameter, T*2 , was mapped showing sensitivity to changes in tidal volume and oxygen level. The T*2 values ranged from 9.2 to 15.9 ms in the intrapulmonary airspaces depending on the breathing paradigm. Experimental results

  19. Concentrated Solutions of Single-Chain Nanoparticles: A Simple Model for Intrinsically Disordered Proteins under Crowding Conditions.

    Science.gov (United States)

    Moreno, Angel J; Lo Verso, Federica; Arbe, Arantxa; Pomposo, José A; Colmenero, Juan

    2016-03-03

    By means of large-scale computer simulations and small-angle neutron scattering (SANS), we investigate solutions of single-chain nanoparticles (SCNPs), covering the whole concentration range from infinite dilution to melt density. The analysis of the conformational properties of the SCNPs reveals that these synthetic nano-objects share basic ingredients with intrinsically disordered proteins (IDPs), as topological polydispersity, generally sparse conformations, and locally compact domains. We investigate the role of the architecture of the SCNPs in their collapse behavior under macromolecular crowding. Unlike in the case of linear macromolecules, which experience the usual transition from self-avoiding to Gaussian random-walk conformations, crowding leads to collapsed conformations of SCNPs resembling those of crumpled globules. This behavior is already found at volume fractions (about 30%) that are characteristic of crowding in cellular environments. The simulation results are confirmed by the SANS experiments. Our results for SCNPs--a model system free of specific interactions--propose a general scenario for the effect of steric crowding on IDPs: collapse from sparse conformations at high dilution to crumpled globular conformations in cell environments.

  20. Hydrothermally synthesized PZT film grown in highly concentrated KOH solution with large electromechanical coupling coefficient for resonator

    Science.gov (United States)

    Feng, Guo-Hua; Lee, Kuan-Yi

    2017-12-01

    This paper presents a study of lead zirconate titanate (PZT) films hydrothermally grown on a dome-shaped titanium diaphragm. Few articles in the literature address the implementation of hydrothermal PZT films on curved-diaphragm substrates for resonators. In this study, a 50-μm-thick titanium sheet is embossed using balls of designed dimensions to shape a dome-shaped cavity array. Through single-process hydrothermal synthesis, PZT films are grown on both sides of the processed titanium diaphragm with good adhesion and uniformity. The hydrothermal synthesis process involves a high concentration of potassium hydroxide solution and excess amounts of lead acetate and zirconium oxychloride octahydrate. Varied deposition times and temperatures of PZT films are investigated. The grown films are characterized by X-ray diffraction and scanning electron microscopy. The 10-μm-thick PZT dome-shaped resonators with 60- and 20-μm-thick supporting layers are implemented and further tested. Results for both resonators indicate that large electromechanical coupling coefficients and a series resonance of 95 MHz from 14 MHz can be attained. The device is connected to a complementary metal-oxide-semiconductor integrated circuit for analysis of oscillator applications. The oscillator reaches a Q value of 6300 in air. The resonator exhibits a better sensing stability when loaded with water when compared with air.

  1. MEH-PPV and PCBM Solution Concentration Dependence of Inverted-Type Organic Solar Cells Based on Eosin-Y-Coated ZnO Nanorod Arrays

    Directory of Open Access Journals (Sweden)

    Riski Titian Ginting

    2013-01-01

    Full Text Available The influence of polymer solution concentration on the performance of chlorobenzene- (CB- and chloroform- (CF- based inverted-type organic solar cells has been investigated. The organic photoactive layers consisted of poly(2-methoxy-5-(2-ethyl hexyloxy-1,4-phenylenevinylene (MEH-PPV and (6,6-phenyl C61 butyric acid methyl ester (PCBM were spin coated from CF with concentrations of 4, 6, and 8 mg/mL and from CB with concentrations of 6, 8, and 10 mg/mL onto Eosin-Y-coated ZnO nanorod arrays (NRAs. Fluorine doped tin oxide (FTO and silver (Ag were used as electron collecting electrode and hole collecting electrode, respectively. Experimental results showed that the short circuit current density and power conversion efficiency increased with decrease of solution concentration for both CB and CF devices, which could be attributed to reducing charge recombination in thinner photoactive layer and larger contact area between the rougher photoactive layer and Ag contact. However, the open circuit voltage decreased with decreasing solution concentration due to increase of leakage current from ZnO NRAs to Ag as the ZnO NRAs were not fully covered by the polymer blend. The highest power conversion efficiencies of 0.54 ± 0.10% and 0.87 ± 0.15% were achieved at the respective lowest solution concentrations of CB and CF.

  2. Influence of pH, temperature, and concentration on stabilization of aqueous hornet silk solution and fabrication of salt-free materials.

    Science.gov (United States)

    Kameda, Tsunenori

    2015-01-01

    We found that an aqueous solution of silk from cocoons produced by hornet larvae (hornet silk) can be obtained when the solution is adjusted to basic conditions of pH > 9.2. It is known that native hornet cocoons can be dissolved in concentrated aqueous solution of salts, such as lithium bromide (LiBr) and calcium chloride (CaCl2). Upon the removal of these salts from solution by dialysis, solidification, gelation, or sedimentation of hornet silk is known to occur. In the present study, under basic conditions, however, no such solidification occurred, even after salt removal. In this study, ammonia was used for alkalization of solution because it is volatilized during the casting process and pure hornet silk materials can be obtained after drying. The effects of the concentrations of hornet silk and ammonia, as well as dialysis temperature, on preventing gelation during dialysis were investigated. Dialysis conditions that limit the degradation of hornet silk by hydrolysis in alkali solution were identified. Moreover, casting conditions to prepare flexible and transparent hornet silk film from aqueous ammonia solution were optimized. Molecular structural analysis of hornet silk in aqueous ammonia solution and cast film indicated the formation of α-helix conformations. © 2014 Wiley Periodicals, Inc.

  3. Influence de la concentration de la solution nutritive sur la croissance et la nutrition minérale de la tomate

    OpenAIRE

    Morard, Philippe; Caumes, Edith; Silvestre, Jérôme

    2004-01-01

    L’influence de deux concentrations de solution nutritive a été étudiée sur la croissance et la nutrition minérale de la tomate en culture hydroponique sous serre au stade début floraison. La force ionique de la solution nutritive la plus concentrée était de 20.00 meq L–1 (SNC), valeur proche de celle qui est habituellement utilisée pour la culture de la tomate ; celle de la solution diluée (SND) était de 3.25 meq L–1. Pendant les deux semaines de l’expérimentation, la concentration du milieu ...

  4. Characterization and flip angle calibration of 13C surface coils for hyperpolarization studies

    DEFF Research Database (Denmark)

    Hansen, Rie Beck; Gutte, Henrik; Larsen, Majbrit M E

    The aim of the present work is to address the challenge of optimal The aim of the present work is to address the challenge of optimal flflip angle calibration of ip angle calibration of C surface coils in C surface coils in hyperpolarization studies. To this end, we characterize the spatial pro h...

  5. Role of endothelium-derived hyperpolarization in the vasodilatation of rat intrarenal arteries

    DEFF Research Database (Denmark)

    Pinilla, Estéfano; Sánchez-Pina, Ana; Muñoz Picos, Mercedes

    2016-01-01

    Background and purpose: Endothelium-dependent vasodilation plays an important role in the regulation of vascular tone in different vascular beds. Besides the release of prostacyclin (PGI2) and nitric oxide (NO), the endothelium mediates vasodilation through endothelium-derived hyperpolarization (...

  6. Large dose hyperpolarized water with dissolution-DNP at high magnetic field

    DEFF Research Database (Denmark)

    Lipsø, Hans Kasper Wigh; Bowen, Sean; Rybalko, Oleksandr

    2016-01-01

    was polarized and dissolved in a fluid path compatible with clinical polarizers. The volume of hyperpolarized water produced by this method enables angiography and perfusion measurements in large animals, as well as NMR experiments for studies of e.g. proton exchange and polarization transfer to other nuclei....

  7. Irreversible Catalyst Activation Enables Hyperpolarization and Water Solubility for NMR Signal Amplification by Reversible Exchange

    Science.gov (United States)

    2016-09-12

    G. R.; Duckett, S. B.; Spiess , H. W.; Schreiber, L. M.; Münnemann, K. Continuous Proton Hyperpolarization Via SABRE and Hollow Fibre Membranes. Proc...M.; Kindervater, P.; Raich, H.-P.; Bargon, J.; Spiess , H. W.; Muennemann, K. Continuous H-1 and C-13 Signal Enhancement in NMR Spectroscopy and MRI

  8. Phase dependency of electrotonic spread of hyperpolarizing current pulses in the rabbit sinoatrial node

    NARCIS (Netherlands)

    Duivenvoorden, J. J.; Bouman, L. N.; Bukauskas, F. F.; Opthof, T.; Jongsma, H. J.

    1990-01-01

    Electrotonic current spread in the SA node of the rabbit was measured by means of hyperpolarizing current pulses (1 to 10 microA, 60 ms), which were injected intracellularly through a K(+)-perfused suction electrode. The pulses were applied at the beginning, middle or end of the diastolic

  9. Hyperpolarized 3-helium MR imaging of the lungs: testing the concept of a central production facility

    International Nuclear Information System (INIS)

    Beek, E.J.R. van; Schmiedeskamp, J.; Filbir, F.; Heil, W.; Wolf, M.; Otten, E.; Wild, J.M.; Paley, M.N.J.; Fichele, S.; Woodhouse, N.; Swift, A.; Knitz, F.; Mills, G.H.

    2003-01-01

    The aim of this study was to test the feasibility of a central production facility with distribution network for implementation of hyperpolarized 3-helium MRI. The 3-helium was hyperpolarized to 50-65% using a large-scale production facility based at a university in Germany. Using a specially designed transport box, containing a permanent low-field shielded magnet and dedicated iron-free glass cells, the hyperpolarized 3-helium gas was transported via airfreight to a university in the UK. At this location, the gas was used to perform in vivo MR experiments in normal volunteers and patients with chronic obstructive lung diseases. Following initial tests, the transport (road-air-road cargo) was successfully arranged on six occasions (approximately once per month). The duration of transport to imaging averaged 18 h (range 16-20 h), which was due mainly to organizational issues such as working times and flight connections. During the course of the project, polarization at imaging increased from 20% to more than 30%. A total of 4 healthy volunteers and 8 patients with chronic obstructive pulmonary disease were imaged. The feasibility of a central production facility for hyperpolarized 3-helium was demonstrated. This should enable a wider distribution of gas for this novel technology without the need for local start-up costs. (orig.)

  10. Synthesis of long T silicon nanoparticles for hyperpolarized Si magnetic resonance imaging

    DEFF Research Database (Denmark)

    Atkins, T.M.; Ganguly, S.; Kauzlarich, S.M.

    2013-01-01

    silicide (Na Si) and silicon tetrachloride (SiCl) and were surface functionalized with a variety of passivating ligands. The synthesis scheme results in particles of diameter ~10 nm with long size-adjusted Si spin-lattice relaxation (T) times (>600 s), which are retained after hyperpolarization by low...

  11. Renal MR angiography and perfusion in the pig using hyperpolarized water.

    Science.gov (United States)

    Wigh Lipsø, Kasper; Hansen, Esben Søvsø Szocska; Tougaard, Rasmus Stilling; Laustsen, Christoffer; Ardenkjaer-Larsen, Jan Henrik

    2017-09-01

    To study hyperpolarized water as an angiography and perfusion tracer in a large animal model. Protons dissolved in deuterium oxide (D 2 O) were hyperpolarized in a SPINlab dissolution dynamic nuclear polarization (dDNP) polarizer and subsequently investigated in vivo in a pig model at 3 Tesla (T). Approximately 15 mL of hyperpolarized water was injected in the renal artery by hand over 4-5 s. A liquid state polarization of 5.3 ± 0.9% of 3.8 M protons in 15 mL of deuterium oxide was achieved with a T 1 of 24 ± 1 s. This allowed injection through an arterial catheter into the renal artery and subsequently high-contrast imaging of the entire kidney parenchyma over several seconds. The dynamic images allow quantification of tissue perfusion, with a mean cortical perfusion of 504 ± 123 mL/100 mL/min. Hyperpolarized water MR imaging was successfully demonstrated as a renal angiography and perfusion method. Quantitative perfusion maps of the kidney were obtained in agreement with literature and control experiments with gadolinium contrast. Magn Reson Med 78:1131-1135, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  12. In vivo single-shot (13)C spectroscopic imaging of hyperpolarized metabolites by spatiotemporal encoding

    DEFF Research Database (Denmark)

    Schmidt, Rita; Laustsen, Christoffer; Dumez, Jean-Nicolas

    2014-01-01

    are necessary. Several approaches have been customized for hyperpolarized (13)C MRI, including CSI with a center-out k-space encoding, EPSI, and spectrally selective pulses in combination with spiral EPI acquisitions. Recent studies have described the potential of single-shot alternatives based...... temporal) data sets were obtained at 7T from a murine lymphoma tumor model....

  13. Hyperpolarized 1-13C Pyruvate Imaging of Porcine Cardiac Metabolism shift by GIK Intervention

    DEFF Research Database (Denmark)

    Søvsø Szocska Hansen, Esben; Tougaard, Rasmus Stilling; Mikkelsen, Emmeli

    to evaluate the general feasibility to detect an imposed shift in metabolic substrate utilization during metabolic modulation with glucose, insulin and potassium (GIK) infusion. This study demonstrates that hyperpolarized 13C-pyruvate, in a large animal, is a feasible method for cardiac studies, and...

  14. Adsorption of low concentration ceftazidime from aqueous solutions using impregnated activated carbon promoted by Iron, Copper and Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xiang, E-mail: huxiang@mail.buct.edu.cn [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Research Centre for Environmental Pollution Control and Resource Reuse Engineering of Beijing City, Beijing 100029 (China); Zhang, Hua [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Research Centre for Environmental Pollution Control and Resource Reuse Engineering of Beijing City, Beijing 100029 (China); Sun, Zhirong, E-mail: zrsun@bjut.edu.cn [College of Environmental & Energy Engineering, Beijing University of Technology, Beijing 100124 (China)

    2017-01-15

    Graphical abstract: The graphic abstract describes the research that we used modified activated carbons impregnated with iron nitrate, copper nitrate and aluminium nitrate to adsorb ceftazidime from aqueous solution. The surface functional groups of the modified activated carbons were different, and thus resulted in the big difference in the adsorption performance of the modified activated carbons. The theory and the experiments both showed the preferable adsorption of ceftazidime could be achieved on modified activated carbons. - Highlights: • Three modified activated carbons were prepared by impregnating metal nitrate. • Characteristics of the modified activated carbons were analyzed. • Adsorption capacity of ceftazidime on modified activated carbons was improved. • The adsorption behavior of ceftazidime on modified activated carbons were revealed. • The nature of ceftazidime adsorption on modified activated carbons was elucidated. - Abstract: In this paper, three impregnated activated carbon IAC (AC-Cu, AC-Fe, and AC-Al) promoted by Iron, Copper and Aluminum were used for adsorption of ceftazidime. Iron(III), Copper(II) and Aluminum(III) nitrate were used as an impregnant. The IACs were characterized by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS).The influence of factors, such as ion strength, pH, temperature, initial concentration, and concentration of natural organic matter organic matter on the adsorption process were studied. The adsorption kinetics and isotherms of ceftazidime were studied for the three IACs. The results showed that the adsorption was accurately represented by pseudo-second order model. Under different temperature, the maximum adsorption quantity of ceftazidime on AC-Cu calculated by pseudo-second order kinetic model were 200.0 mg g{sup −1} (298 K), 196.1 mg g{sup −1} (303 K) and 185.2 mg g

  15. Adsorption of low concentration ceftazidime from aqueous solutions using impregnated activated carbon promoted by Iron, Copper and Aluminum

    International Nuclear Information System (INIS)

    Hu, Xiang; Zhang, Hua; Sun, Zhirong

    2017-01-01

    Graphical abstract: The graphic abstract describes the research that we used modified activated carbons impregnated with iron nitrate, copper nitrate and aluminium nitrate to adsorb ceftazidime from aqueous solution. The surface functional groups of the modified activated carbons were different, and thus resulted in the big difference in the adsorption performance of the modified activated carbons. The theory and the experiments both showed the preferable adsorption of ceftazidime could be achieved on modified activated carbons. - Highlights: • Three modified activated carbons were prepared by impregnating metal nitrate. • Characteristics of the modified activated carbons were analyzed. • Adsorption capacity of ceftazidime on modified activated carbons was improved. • The adsorption behavior of ceftazidime on modified activated carbons were revealed. • The nature of ceftazidime adsorption on modified activated carbons was elucidated. - Abstract: In this paper, three impregnated activated carbon IAC (AC-Cu, AC-Fe, and AC-Al) promoted by Iron, Copper and Aluminum were used for adsorption of ceftazidime. Iron(III), Copper(II) and Aluminum(III) nitrate were used as an impregnant. The IACs were characterized by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS).The influence of factors, such as ion strength, pH, temperature, initial concentration, and concentration of natural organic matter organic matter on the adsorption process were studied. The adsorption kinetics and isotherms of ceftazidime were studied for the three IACs. The results showed that the adsorption was accurately represented by pseudo-second order model. Under different temperature, the maximum adsorption quantity of ceftazidime on AC-Cu calculated by pseudo-second order kinetic model were 200.0 mg g"−"1 (298 K), 196.1 mg g"−"1 (303 K) and 185.2 mg g"−"1 (308 K

  16. The role of bicarbonate in platelet additive solution for apheresis platelet concentrates stored with low residual plasma.

    Science.gov (United States)

    Radwanski, Katherine; Min, Kyungyoon

    2013-03-01

    Complex platelet additive solutions (PASs) are required to store platelet (PLT) concentrates with plasma levels below 30%. Previously, apheresis PLTs stored with 5% plasma in acetate- and bicarbonate-containing PAS maintained stable pH and bicarbonate levels during 7-day storage. Due to this observation, the necessity of added bicarbonate in PAS was investigated and whether the concurrent increase in PAS pH after bicarbonate addition had any effect on PLT storage. Apheresis PLTs were stored in 5% plasma-95% high- or low-pH PAS, with or without bicarbonate (n=10 per arm). Bicarbonate PAS PLTs were paired and nonbicarbonate PAS PLTs were paired (split from same double-dose collection). PLTs were evaluated for in vitro variables on Days 1 and 7 and up to Day 14 if the Day 7 pH was higher than 6.2. PLT pH was maintained above 7.3 to Day 14 in bicarbonate PAS PLTs while pH failures below 6.2 were observed in 4 of 10 and 2 of 10 units on Day 7 in low- and high-pH nonbicarbonate PAS arms, respectively. Day 7 in vitro variables in nonbicarbonate PAS PLTs with pH values of higher than 6.2 were comparable to Day 7 variables in bicarbonate PAS PLTs. The pH of bicarbonate PAS did have a small effect on pH and bicarbonate levels in PLT units, but did not have an effect on functional variables and metabolism. Bicarbonate was not required to maintain in vitro PLT function in 5% plasma-95% PAS, but was required as a pH buffer and increased PAS pH did not significantly contribute to this effect. © 2012 American Association of Blood Banks.

  17. Gamma radiation and osmotic potential of the nutrient solution differentially affect macronutrient concentrations, pH and EC in chilhuacle pepper fruits

    International Nuclear Information System (INIS)

    Victor Garcia-Gaytan, Libia Iris Trejo-Tellez; Olga Tejeda-Sartorius; Maribel Ramirez-Martinez; Julian Delgadillo-Martinez; Fernando Carlos Gomez-Merino; Soledad Garcia-Morales

    2018-01-01

    Chilhuacle pepper (Capsicum annuum L.) seeds were exposed to gamma radiation (GR) doses (0, 10, 80 and 120 Gy), and plants were grown in hydroponics with different osmotic potentials (OP) (- 0.036, - 0.072, - 0.092, and - 0.108 MPa) in the nutrient solution. We measured the nutrient concentrations, pH and electrical conductivity (EC) in fruits at different time points after transplanting (70, 90 and 130 dat), and found the GR, nutrient solution OP and their interactions differentially affected N, P, K, Ca, and Mg concentrations, as well as pH and EC in chilhuacle peppers. (author)

  18. Effect of Nitrogen Form and pH of Nutrient Solution on the Shoot Concentration of Phosphorus, Nitrate, and Nitrogen of Spinach in Hydroponic Culture

    OpenAIRE

    N. Najafi; M. Parsazadeh

    2010-01-01

    In order to study the effect of nitrogen form and pH of nutrient solution on the shoot concentration of P, nitrate, organic N + inorganic ammonium, and total N of spinach, a factorial experiment was conducted with two factors including pH of nutrient solution in three levels (4.5, 6.5 and 8.0) and nitrate to ammonium ratio of nutrient solution in five levels (100:0, 75:25, 50:50, 25:75 and 0:100). This factorial experiment was carried out in a completely randomized design with four replicatio...

  19. The effect of temperature and concentration on the corrosion inhibition mechanism of an amphiphilic amido-amine in CO2 saturated solution

    OpenAIRE

    Desimone, Paula Mariela; Gordillo, Gabriel Jorge; Simison, Silvia Noemi

    2017-01-01

    The corrosion inhibition mechanism of the N-[2-[(2-aminoethyl)amino]ethyl]-9-octadecenamide on mild steel surface in CO2-saturated 5% NaCl solution has been studied. The inhibition efficiency decreases with increasing temperature. Adsorption of the inhibitor studied is found to follow the Frumkin adsorption isotherm. EIS results show that the mechanism of its corrosion inhibition at concentrations higher than critical micelle concentration is by forming a protective porous bi-layer. The a...

  20. Real-time tracking of dissociation of hyperpolarized 89Y-DTPA: a model for degradation of open-chain Gd3+ MRI contrast agents

    Science.gov (United States)

    Ferguson, Sarah; Niedbalski, Peter; Parish, Christopher; Kiswandhi, Andhika; Kovacs, Zoltan; Lumata, Lloyd

    Gadolinium (Gd) complexes are widely used relaxation-based clinical contrast agents in magnetic resonance imaging (MRI). Gd-based MRI contrast agents with open-chain ligand such as Gd-DTPA, commercially known as magnevist, are less stable compared to Gd complexes with macrocyclic ligands such as GdDOTA (Dotarem). The dissociation of Gd-DPTA into Gd ion and DTPA ligand under certain biological conditions such as high zinc levels can potentially cause kidney damage. Since Gd is paramagnetic, direct NMR detection of the Gd-DTPA dissociation is quite challenging due to ultra-short relaxation times. In this work, we have investigated Y-DTPA as a model for Gd-DPTA dissociation under high zinc content solutions. Using dissolution dynamic nuclear polarization (DNP), the 89Y NMR signal is amplified by several thousand-fold. Due to the the relatively long T1 relaxation time of 89Y which translates to hyperpolarization lifetime of several minutes, the dissociation of Y-DTPA can be tracked in real-time by hyperpolarized 89Y NMR spectroscopy. Dissociation kinetic rates and implications on the degradation of open-chain Gd3+ MRI contrast agents will be discussed. This work was supported by the U.S. Department of Defense Award Number W81XWH-14-1-0048 and by the Robert A. Welch Foundation research Grant Number AT-1877.

  1. [Effects of nitrogen deposition on the concentration and spectral characteristics of dissolved organic matter in soil solution in a young Cunninghamia lanceolata plantation.

    Science.gov (United States)

    Yuan, Xiao Chun; Chen, Yue Min; Yuan, Shuo; Zheng, Wei; Si, You Tao; Yuan, Zhi Peng; Lin, Wei Sheng; Yang, Yu Sheng

    2017-01-01

    To study the effects of nitrogen deposition on the concentration and spectral characteristics of dissolved organic matter (DOM) in the forest soil solution from the subtropical Cunninghamia lanceolata plantation, using negative pressure sampling method, the dynamics of DOM in soil solutions from 0-15 and 15-30 cm soil layer was monitored for two years and the spectroscopic features of DOM were analyzed. The results showed that nitrogen deposition significantly reduced the concentration of dissolved organic carbon (DOC), and increased the aromatic index (AI) and the humic index (HIX), but had no significant effect on dissolved organic nitrogen (DON) concentration in both soil layers. There was obvious seasonal variation in DOM concentration of the soil solution, which was prominently higher in summer and autumn than in spring and winter.Fourier-transform infrared (FTIR) absorption spectrometry indicated that the DOM in forest soil solution had absorption peaks in the similar position of six regions, being the highest in wave number of 1145-1149 cm -1 . Three-dimensional fluorescence spectra indicated that DOM was mainly consisted of protein-like substances (Ex/Em=230 nm/300 nm) and microbial degradation products (Ex/Em=275 nm/300 nm). The availability of protein-like substances from 0-15 cm soil layer was reduced in the nitrogen treatments. Nitrogen deposition significantly reduced the concentration of DOC in soil solution, maybe largely by reducing soil pH, inhibiting soil carbon mineralization and stimulating plant growth. In particular, the decline of DOC concentration in the surface layer was due to the production inhibition of the protein-like substances and carboxylic acids. Short-term nitrogen deposition might be beneficial to the maintenance of soil fertility, while the long-term accumulation of nitrogen deposition might lead to the hard utilization of soil nutrients.

  2. Effects of intravenous administration of two volumes of calcium solution on plasma ionized calcium concentration and recovery from naturally occurring hypocalcemia in lactating dairy cows.

    NARCIS (Netherlands)

    Doze, J.G.; Donders, R.; Kolk, J.H. van der

    2008-01-01

    OBJECTIVE: To compare the effects of administration of 2 volumes of a calcium solution (calcium oxide and calcium gluconate) on plasma ionized calcium concentration (PICaC) and clinical recovery from naturally occurring hypocalcemia (NOHC; milk fever) in lactating dairy cows. ANIMALS: 123 cows with

  3. Multisite Ion Model in Concentrated Solutions of Divalent Cations (MgCl2 and CaCl2): Osmotic Pressure Calculations

    Science.gov (United States)

    2015-01-01

    Accurate force field parameters for ions are essential for meaningful simulation studies of proteins and nucleic acids. Currently accepted models of ions, especially for divalent ions, do not necessarily reproduce the right physiological behavior of Ca2+ and Mg2+ ions. Saxena and Sept (J. Chem. Theor. Comput.2013, 9, 3538–3542) described a model, called the multisite-ion model, where instead of treating the ions as an isolated sphere, the charge was split into multiple sites with partial charge. This model provided accurate inner shell coordination of the ion with biomolecules and predicted better free energies for proteins and nucleic acids. Here, we expand and refine the multisite model to describe the behavior of divalent ions in concentrated MgCl2 and CaCl2 electrolyte solutions, eliminating the unusual ion–ion pairing and clustering of ions which occurred in the original model. We calibrate and improve the parameters of the multisite model by matching the osmotic pressure of concentrated solutions of MgCl2 to the experimental values and then use these parameters to test the behavior of CaCl2 solutions. We find that the concentrated solutions of both divalent ions exhibit the experimentally observed behavior with correct osmotic pressure, the presence of solvent separated ion pairs instead of direct ion pairs, and no aggregation of ions. The improved multisite model for (Mg2+ and Ca2+) can be used in classical simulations of biomolecules at physiologically relevant salt concentrations. PMID:25482831

  4. Analytical solution for a strained reinforcement layer bonded to lip-shaped crack under remote mode Ⅲ uniform load and concentrated load

    Institute of Scientific and Technical Information of China (English)

    You-wen LIU; Chao XIE; Chun-zhi JIANG; Qi-hong FANG

    2010-01-01

    In this paper,the analytical solution of stress field for a strained reinforcement layer bonded to a lip-shaped crack under a remote mode Ⅲ uniform load and a concentrated load is obtained explicitly in the series form by using the technical of conformal mapping and the method of analytic continuation.The effects of material combinations,bond of interface and geometric configurations on interfacial stresses generated by eigenstrain,remote load and concentrated load are studied.The results show that the stress concentration and interfacial stresses can be reduced by rational material combinations and geometric configurations designs for different load forms.

  5. Exact Solution of Fractional Diffusion Model with Source Term used in Study of Concentration of Fission Product in Uranium Dioxide Particle

    International Nuclear Information System (INIS)

    Fang Chao; Cao Jianzhu; Sun Lifeng

    2011-01-01

    The exact solution of fractional diffusion model with a location-independent source term used in the study of the concentration of fission product in spherical uranium dioxide (UO 2 ) particle is built. The adsorption effect of the fission product on the surface of the UO 2 particle and the delayed decay effect are also considered. The solution is given in terms of Mittag-Leffler function with finite Hankel integral transformation and Laplace transformation. At last, the reduced forms of the solution under some special physical conditions, which is used in nuclear engineering, are obtained and corresponding remarks are given to provide significant exact results to the concentration analysis of nuclear fission products in nuclear reactor. (nuclear physics)

  6. Flexible electromagnetic wave sensor operating at GHz frequencies for instantaneous concentration measurements of NaCl, KCl, MnCl2 and CuCl solutions

    International Nuclear Information System (INIS)

    Korostynska, O; Ortoneda-Pedrola, M; Mason, A; Al-Shamma'a, A I

    2014-01-01

    A novel electromagnetic wave sensor operating at GHz frequencies for real-time chlorides concentration analysis is reported. The sensor response to deionized water, NaCl, KCl, MnCl 2  and CuCl solutions at various concentrations was tested. The sensing element, in the form of a silver pattern antenna that emits an electromagnetic field, was printed on a polyimide flexible laminate substrate to form a sensor to suit a broad range of applications, where a sensor could be placed in water reservoirs or fluid-carrying pipes for continuous analysis. The developed system confirmed the viability of using microwaves for real-time chloride solutions monitoring as the reflected signals represented by S 11  parameters were unique with clearly observed shifts in the resonant frequencies and amplitude changes when placed in direct contact with 20 µl of each solution. (paper)

  7. Complete study of the existence and uniqueness of solutions for semilinear elliptic equations involving measures concentrated on boundary

    KAUST Repository

    Chen, Huyuan

    2017-02-06

    The purpose of this paper is to study the weak solutions of the fractional elliptic problem(Formula presented.) where (Formula presented.), (Formula presented.) or (Formula presented.), (Formula presented.) with (Formula presented.) is the fractional Laplacian defined in the principle value sense, (Formula presented.) is a bounded (Formula presented.) open set in (Formula presented.) with (Formula presented.), (Formula presented.) is a bounded Radon measure supported in (Formula presented.) and (Formula presented.) is defined in the distribution sense, i.e.(Formula presented.) here (Formula presented.) denotes the unit inward normal vector at (Formula presented.). In this paper, we prove that (0.1) with (Formula presented.) admits a unique weak solution when g is a continuous nondecreasing function satisfying(Formula presented.) Our interest then is to analyse the properties of weak solution when (Formula presented.) with (Formula presented.), including the asymptotic behaviour near (Formula presented.) and the limit of weak solutions as (Formula presented.). Furthermore, we show the optimality of the critical value (Formula presented.) in a certain sense, by proving the non-existence of weak solutions when (Formula presented.). The final part of this article is devoted to the study of existence for positive weak solutions to (0.1) when (Formula presented.) and (Formula presented.) is a bounded nonnegative Radon measure supported in (Formula presented.). We employ the Schauder’s fixed point theorem to obtain positive solution under the hypothesis that g is a continuous function satisfying(Formula presented.)-pagination

  8. Equilibrium solubility of CO{sub 2} in aqueous solutions of 1-amino-2-propanol as function of concentration, temperature, and pressure

    Energy Technology Data Exchange (ETDEWEB)

    Rebolledo-Morales, Miguel Angel; Rebolledo-Libreros, Maria Esther [Instituto Mexicano del Petroleo, Direccion de Investigacion y Posgrado, Programa de Ingenieria Molecular, Area de Investigacion de Termofisica, Eje Central Lazaro Cardenas Norte 152, 07730 Mexico, D.F. (Mexico); Trejo, Arturo, E-mail: atrejo@imp.m [Instituto Mexicano del Petroleo, Direccion de Investigacion y Posgrado, Programa de Ingenieria Molecular, Area de Investigacion de Termofisica, Eje Central Lazaro Cardenas Norte 152, 07730 Mexico, D.F. (Mexico)

    2011-05-15

    Research highlights: Gas solubility of CO{sub 2} in aqueous solutions of 1-amino-2-propanol was measured. Solubility increases as pressure and concentration of 1-amino-2-propanol increase. The Kent-Eisenberg model was used to correlate all the experimental results. Aqueous solutions of MIPA are an excellent alternative to use in gas purification. - Abstract: Using a dynamic method with recirculation of the vapour phase, experimental values for the gas solubility of carbon dioxide in aqueous solutions of 1-amino-2-propanol (MIPA) were measured at T = (313.15 and 393.15) K, over the pressure range of (0.2 to 2436.4) kPa. The concentrations of the studied aqueous MIPA solutions were (0.20, 0.30, 0.40, and 0.50) mass fraction. The results of gas solubility are given as the partial pressure of CO{sub 2}, p{sub CO{sub 2}}, against its mole ratio, {alpha}{sub CO{sub 2}} (mol CO{sub 2} {center_dot} mol{sup -1} MIPA), and its mole fraction, x{sub CO{sub 2}}. It is observed that the solubility of CO{sub 2} increases as the concentration of MIPA in solution increases, at a given temperature throughout the pressure range considered; also the solubility values increase, under constant temperature, as the pressure increases in the studied concentration range of MIPA. The physicochemical model of Kent and Eisenberg was used to correlate simultaneously all the experimental results of the solubility of CO{sub 2} in the studied aqueous solutions of MIPA. The model correlates satisfactorily the experimental results. The deviation for pressure was 96.9 kPa using 62 experimental solubility points. The solubility results of carbon dioxide presented in this work are compared with those reported in the literature for aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), diisopropanolamine (DIPA), and N-methyldiethanolamine (MDEA) and it is possible to conclude that the aqueous solutions of MIPA are an excellent alternative to use in gas purification processes, since the

  9. Influence of Proton and Salt Concentration on the Chromonic Liquid Crystal Phase Diagram of Disodium Cromoglycate Solutions: Prospects and Limitations of a Host for DNA Nanostructures.

    Science.gov (United States)

    Zhang, Bingru; Kitzerow, Heinz-S

    2016-03-31

    Lyotropic chromonic liquid crystals have recently been suggested for use as a self-organized host for dispersing and aligning self-organized DNA origami nanostructures. However, an appropriate pH value and a suitable cation concentration are necessary to stabilize such nanostructures and to avoid unfolding of the DNA. The present study shows that the nematic and columnar liquid crystal phases appearing in aqueous solutions of disodium cromoglycate are robust against the replacement of deionized water by a neutral or alkaline buffer solution. However, disodium cromoglycate precipitates when an acidic buffer is used or when the concentration of magnesium cations exceeds a critical concentration of about 0.6-0.7 mmol/L.

  10. Lowering of the critical concentration for micelle formation in aqueous soap solutions by action of truly dissolved hydrocarbon at various temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Markina, Z.N.; Kostova, N.Z.; Rebinder, P.A.

    1970-03-01

    The effect of dissolved hydrocarbons (octane, benzene, and ethylbenzene) on critical micelle concentration of aqueous solutions of sodium salts of fatty acids from caproate to sodium myristate at various temperatures was studied. Experimental results showed that formation of micelles is promoted by presence of hydrocarbons dissolved in the water phase. Such solutions have below normal critical micelle concentration. The change in critical micelle concentration decreases with increase in length of hydrocarbon chain in the soap molecule and with decrease of hydrocarbon solubility in pure water. The nature of the hydrocarbon also affects the forms and dimension of the micelle. Aromatic hydrocarbons increase micelle volume and greatly decrease C.M.C., while aliphatic hydrocarbons decrease C.M.C. slightly. (12 refs.)

  11. Solution phase thermodynamics of strong electrolytes based on ionic concentrations, hydration numbers and volumes of dissolved entities

    Czech Academy of Sciences Publication Activity Database

    Heyrovská, Raji

    2013-01-01

    Roč. 24, č. 6 (2013), s. 1895-1901 ISSN 1040-0400 Institutional support: RVO:68081707 Keywords : Solution thermodynamics * Aqueous electrolytes * Partial electrolytic dissociation Subject RIV: BO - Biophysics Impact factor: 1.900, year: 2013

  12. X-ray diffraction study on the structure of concentrated aqueous solutions involving alanine molecules with different optical activities

    International Nuclear Information System (INIS)

    Kameda, Yasuo; Okuyama, Aya; Amo, Yuko; Usuki, Takeshi; Kohara, Shinji

    2007-01-01

    X-ray diffraction measurements on aqueous 2.5 mol% DL-, L-, and D-alanine solutions in D 2 O were carried out at 26±2degC in order to obtain information concerning the difference in the hydrogen-bonded structure between aqueous solutions involving amino acid molecules with different optical activities. The difference function, Δi inter (Q), between intermolecular interference term observed for DL- and L-alanine and between DL- and D-alanine solutions both exhibited a first peak at Q=1.6 A -1 , followed by oscillatory features extending to higher-Q region, implying that there is a difference in the intermolecular structure is present between these solutions. The difference distribution function, Δg inter (r), obtained from the Fourier transform of the Δi inter (Q) between DL- and L-, and between DL- and D-alanine solutions showed an obvious negative peak at r=2.8 A, which was attributed to the nearest neighbor hydrogen-bonded O...O interaction. The least squares fitting analysis of the observed Δi inter (Q) showed that the intermolecular O...O distance and the difference in the coordination number between DL- and L-, and between DL- and D-alanine solutions are 2.76(2) A and -0.18(1), and 2.81(3) A and -0.18(1), respectively. It was concluded that the intermolecular hydrogen-bonded network in aqueous L- and D-alanine solutions is stronger than that in the DL-alanine solution. (author)

  13. Calibration of X-ray densitometers for the determination of uranium and plutonium concentrations in reprocessing input and product solutions

    International Nuclear Information System (INIS)

    Ottmar, H.; Eberle, H.; Michel-Piper, I.; Kuhn, E.; Johnson, E.

    1985-11-01

    In June 1985 a calibration exercise has been carried out, which included the calibration of the KfK K-Edge Densitometer for uranium assay in the uranium product solutions from reprocessing, and the calibration of the Hybrid K-Edge/K-XRF Instrument for the determination of total uranium and plutonium in reprocessing input solutions. The calibration measuremnts performed with the two X-ray densitometers are described and analyzed, and calibration constants are evaluated from the obtained results. (orig.)

  14. Np(V)/Np(IV) in concentrated carbonate/bicarbonate solutions; Np(V)/Np(IV) en solutions carbonate/bicarbonate concentrees

    Energy Technology Data Exchange (ETDEWEB)

    Delmau, L.H.; Vitorge, P.; Capdevila, H.

    1996-01-01

    A 1.5 M Na{sub 2}CO{sub 3} solution of Np(V) is electrolysed to Np(IV) at -2.0 V/SHE. -1g(H{sup +}) is decreased from 10.4 to 7.2 by bubbling CO{sub 2} in these solutions, where Np(IV) spectra can be interpreted with the only lost of one CO{sub 3}{sup 2-} anion from the Np(IV) limiting complex. From these spectral changes, the following parameters are fitted: 20.5 {+-} 2.1, 8.44 {+-} 0.9 and 28.9 {+-} 2.9 l/mol./cm for the Np(CO{sub 3}){sub 5}{sup 6-} molar absorptivity at 823, 990 and 1013 nm respectively, and 54.5 {+-} 5.5, 40.6 {+-} 4.1 and 8.53 {+-} 0.9 for the Np(CO{sub 3}){sub 4}{sup 4-} ones, and log((Np(CO{sub 3}){sub 5}{sup 6-}) / ((Np(CO{sub 3}){sub 4}{sup 4-})(CO{sub 3}{sup 2-}))) = 1.47 {+-} 0.08, 1.63 {+-} 0.05, 1.80 {+-} 0.04, 1.79 {+-} 0.10 and 2.21 {+-} 0.03 at the half point reaction in initially 0.2, 0.3, 0.4, 0.5 and 0.6 M Na{sub 2}CO{sub 3} solutions. These values are extrapolated to 0 ionic strength by using the Specific Interaction Theory (SIT). The redox potential of 0.3, 0.6, 1 and 1.5 M Na{sub 2}CO{sub 3} solutions of Np(V) and Np(IV) mixtures, is stable usually after three hours at T from 5 to 60 deg C, and then for up to three weeks at 21.5 deg C. At 25 deg C, its values are 0.247, 0.234, 0.244 and 0.228 V/SEH in 0.3, 0.6, 1 and 1.5 M Na{sub 2}CO{sub 3} solutions. When the tonic strength is equal to 0: E = 0.52 {+-} 0.1 V/SEH and {Delta}S/F = -1.1 {+-} 0.7 mV. deg C{sup -1}. Assuming this potential is controlled by the NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-} + 2 CO{sub 2} + e{sup -} {r_reversible} Np(CO{sub 3}){sub 5}{sup 6-} equilibrium, the formation constant of the limiting complex is deduced by using published values of the other needed equilibria: log {Beta}{sub 5}{sup d}eg = 38 {+-} 4. Qualitative results on the preparation and on the spectra of Np(IV) are used to explain the apparent contradictions between some published results. (authors). 39 refs., figs., tabs.

  15. Immediate Effect of 3% Diquafosol Ophthalmic Solution on Tear MUC5AC Concentration and Corneal Wetting Ability in Normal and Experimental Keratoconjunctivitis Sicca Rat Models.

    Science.gov (United States)

    Choi, Kwang-Eon; Song, Jong-Suk; Kang, Boram; Eom, Youngsub; Kim, Hyo-Myung

    2017-05-01

    To evaluate the immediate effect of 3% diquafosol ophthalmic solution on tear MUC5AC concentration, periodic acid-Schiff (PAS)-positive goblet cells, and tear film stability in normal and keratoconjunctivitis sicca (KCS) rat models. Rats were divided into normal and KCS groups. 3% of diquafosol solution was instilled into the right eye and normal saline into the left eye in both groups. To determine the peak time of tear MUC5AC concentration, tears were collected after 3% diquafosol instillation every 5 min up to 20 min. The tear film stability and the numbers of PAS-positive goblet cells were compared in both models. After diquafosol instillation, tear MUC5AC concentration increased steadily for 15 min, at which point the MUC5AC concentration reached its peak. In both normal and KCS groups, the MUC5AC concentration at 15 min was higher after instillation of 3% diquafosol solution (17.77 ± 2.09 ng/ml in the normal group, 9.65 ± 3.51 ng/ml in the KCS group) than that after saline instillation (13.74 ± 2.87 ng/ml in the normal group, 8.19 ± 3.99 ng/ml in the KCS group) (p = 0.018 for both). The corneal wetting ability was significantly longer after instillation of 3% diquafosol solution compared with that after instillation of normal saline in the normal group (p = 0.018). The percentage of PAS-positive goblet cells after the instillation of 3% diquafosol solution was significantly lower than that after instillation of normal saline in both models (p = 0.018 for both). Diquafosol ophthalmic solution was effective in stimulating mucin secretion in both normal and KCS rat models, and the peak time of tear MUC5AC concentration was 15 min after diquafosol instillation. The increased tear MUC5AC concentration was accompanied by improved tear film stability and a decreased percentage of PAS-positive goblet cells.

  16. Heavy metal toxicities in vegetable crops. VI. The effect of potassium and calcium concentration in the nutrient solution on manganese toxicities in vegetable crops

    Energy Technology Data Exchange (ETDEWEB)

    Osawa, T; Ikeda, H

    1977-01-01

    Eight species of vegetable crops were grown in solution culture in order to investigate the effect of potassium and calcium concentration in the nutrient solution on manganese toxicities in vegetable crops. Manganese was supplied at levels of 0.5, 30, and 100 ppm. At each manganese level potassium or calcium was supplied at rates of 2, 6, and 18 me/l. The pH of the nutrient solution was adjusted to 5. Manganese excess induced interveinal chlorosis on upper leaves in bean, eggplant, pepper, and spinach, and marginal chlorosis on lower leaves in cabbage, lettuce, and celery. In Welsh onions chlorosis was induced on lower leaves. Increasing the supply of potassium and calcium reduced the severity of manganese-induced chlorosis. This beneficial effect was generally more marked with calcium than with potassium. Increasing the supply of potassium and calcium was effective in alleviating the growth reduction of vegetable crops due to manganese excess. This effect also was more marked with calcium than with potassium. With increasing manganese level in the nutrient solution the manganese concentration in leaves of vegetable crops increased. Increasing the supply of potassium and calcium inhibited excessive accumulation of manganese in leaves. The influence of calcium was stronger than that of potassium. In any of the vegetable crops tested, regardless of potassium and calcium treatments, manganese concentration in leaves was closely related to manganese toxicities; the more the accumulation of manganese in leaves increased, the more the severity of manganese-induced chlorosis and growth reduction increased.

  17. Vitamin C and Poly(ethylene glycol) Protect Concentrated Poly(vinyl alcohol) Solutions against Radiation Cross-linking

    International Nuclear Information System (INIS)

    Oral, E.

    2006-01-01

    There is a need for an injectable material to augment damaged cartilage. We propose to make such self-associating poly(vinyl alcohol) (PVA) hydrogels. Physical associations can be formed in PVA using a gellant such as polyethylene glycol (PEG). The injectability of PVA solutions is compromised when sterilized due to chemical cross-linking. We hypothesized that an anticross-linking agent could prevent cross-linking of irradiated PVA solutions. PVA (17.5 wt/v %, MW= 115,000 g/mol) was prepared in water at 90 degree. PEG (MW=400 g/mol) was added at a ratio of PEG unit to PVA unit of 17, 86, 290, and 639 mol/mol. PVA solutions (17.5 wt/v %, MW= 16,000, 61,000, 81,000 and 115,000 g/mol) were also prepared. Vitamin C was added at a molar ratio of vitamin C to PVA unit of 0.75-10.4. Solutions were poured into syringes and γ-irradiated. The viscosity of injectable solutions was determined by using the bubble tube. Gel content of cross-linked samples was measured by boiling gels in water for 6 hours, drying at 90 degree and calculating the ratio of dry weight to 'as is' weight

  18. Investigating tumor perfusion and metabolism using multiple hyperpolarized 13C compounds: HP001, pyruvate and urea

    DEFF Research Database (Denmark)

    von Morze, Cornelius; Larson, Peder E.Z.; Hu, Simon

    2012-01-01

    The metabolically inactive hyperpolarized agents HP001 (bis-1,1-(hydroxymethyl)-[1-13C]cyclopropane-d8) and urea enable a new type of perfusion magnetic resonance imaging based on a direct signal source that is background-free. The addition of perfusion information to metabolic information obtained...... (T1=95 s ex vivo, 32 s in vivo at 3 T) using a pulse sequence with balanced steady-state free precession and ramped flip angle over time for efficient utilization of the hyperpolarized magnetization and three-dimensional echo-planar spectroscopic imaging of urea copolarized with [1-13C...... of separate dynamic HP001 imaging and copolarized pyruvate/urea imaging were compared. A strong and significant correlation (R=0.73, P=.02) detected between the urea and HP001 data confirmed the value of copolarizing urea with pyruvate for simultaneous assessment of perfusion and metabolism....

  19. Dysfunctional Hyperpolarization-Activated Cyclic Nucleotide-gated Ion Channels in Cardiac Diseases

    Directory of Open Access Journals (Sweden)

    Xiaoqi Zhao

    Full Text Available Abstract Hyperpolarization-activated cyclic nucleotide-gated (HCN channels are reverse voltage-dependent, and their activation depends on the hyperpolarization of the membrane and may be directly or indirectly regulated by the cyclic adenosine monophosphate (cAMP or other signal-transduction cascades. The distribution, quantity and activation states of HCN channels differ in tissues throughout the body. Evidence exhibits that HCN channels play critical roles in the generation and conduction of the electrical impulse and the physiopathological process of some cardiac diseases. They may constitute promising drug targets in the treatment of these cardiac diseases. Pharmacological treatment targeting HCN channels is of benefit to these cardiac conditions.

  20. A Liquid Inorganic Electrolyte Showing an Unusually High Lithium Ion Transference Number: A Concentrated Solution of LiAlCl4 in Sulfur Dioxide

    Directory of Open Access Journals (Sweden)

    Martin Winter

    2013-08-01

    Full Text Available We report on studies of an inorganic electrolyte: LiAlCl4 in liquid sulfur dioxide. Concentrated solutions show a very high conductivity when compared with typical electrolytes for lithium ion batteries that are based on organic solvents. Our investigations include conductivity measurements and measurements of transference numbers via nuclear magnetic resonance (NMR and by a classical direct method, Hittorf’s method. For the use of Hittorf’s method, it is necessary to measure the concentration of the electrolyte in a selected cell compartment before and after electrochemical polarization very precisely. This task was finally performed by potentiometric titration after hydrolysis of the salt. The Haven ratio was determined to estimate the association behavior of this very concentrated electrolyte solution. The measured unusually high transference number of the lithium cation of the studied most concentrated solution, a molten solvate LiAlCl4 × 1.6SO2, makes this electrolyte a promising alternative for lithium ion cells with high power ability.

  1. Measuring a 10,000-fold enhancement of singlet molecular oxygen (1O2*) concentration on illuminated ice relative to the corresponding liquid solution

    Science.gov (United States)

    Bower, Jonathan P.; Anastasio, Cort

    2013-08-01

    Much attention has focused on the highly reactive hydroxyl radical in the oxidation of trace organic compounds on snow and ice (and subsequent release of volatile organics to the atmospheric boundary layer) but other oxidants are likely also important in this processing. Here we examine the ice chemistry of singlet molecular oxygen (1O2*), which can be significant in atmospheric water drops but has not been examined in ice or snow. To examine 1O2* on ice we illuminate laboratory ices containing Rose Bengal (RB) as the source of 1O2*, furfuryl alcohol (FFA) as the probe, and Na2SO4 to control the total solute concentration. We find that the 1O2*-mediated loss of FFA (and, thus, the 1O2* concentration) is up to 11,000 times greater on ice than in the equivalent liquid sample at the same photon flux. We attribute this large increase in the 1O2* steady-state concentration to the freeze-concentration of solutes into liquid-like regions (LLRs) in/on ice: compared to the initial solution, in the LLRs of ice the sources for 1O2* are highly concentrated, while the concentration of the dominant sink for 1O2* (i.e., water) remains largely unchanged. Similar to results expected in liquid solution, rates of FFA loss in ice depend on both the initial sensitizer concentration and temperature, providing evidence that these reactions occur in LLRs. However, we find that the enhancement in 1O2* concentrations on ice does not follow predictions from freezing-point depression, likely because experiments were conducted below the eutectic temperature for sodium sulfate, where all of the salt should have precipitated. We also explore a method for separating 1O2* and rad OH contributions to FFA oxidation in laboratory ices and show its application to two natural snow samples. We find that 1O2* concentrations in these snows are approximately 100 times higher than observed in polluted, mid-latitude fog waters, showing that the enhancement of 1O2* on ice is environmentally relevant and that

  2. Imaging cerebral 2-ketoisocaproate metabolism with hyperpolarized (13)C Magnetic Resonance Spectroscopic Imaging

    DEFF Research Database (Denmark)

    Butt, Sadia Asghar; Søgaard, Lise Vejby-Christensen; Magnusson, Peter O.

    2012-01-01

    The branched chain amino acid transaminase (BCAT) has an important role in nitrogen shuttling and glutamate metabolism in the brain. The purpose of this study was to describe the cerebral distribution and metabolism of hyperpolarized 2-keto[1-(13)C]isocaproate (KIC) in the normal rat using magnet...... & Metabolism advance online publication, 28 March 2012; doi:10.1038/jcbfm.2012.34....

  3. The Complete Solution of Fick's Second Law of Diffusion with Time-dependent Diffusion Coefficient and Surface Concentration

    DEFF Research Database (Denmark)

    Mejlbro, Leif

    1996-01-01

    Fick's Second Law of Diffusion with time-dependent diffusioncoefficient and surface concentration is solved. Mimicking the classicalsolution, special time-dependent surface concentration functions areconsidered. These models are used in giving estimates of the lifetimeof the structure, when...... the concrete cover is given, as well as estimatesof the thickness of the concrete cover, when the expected lifetime is given.*Note: Book tilte: Durability of Concrete in Saline Environment...

  4. The role of hyperpolarized {sup 129}xenon in MR imaging of pulmonary function

    Energy Technology Data Exchange (ETDEWEB)

    Ebner, Lukas [Cardiothoracic Imaging, Duke University Medical Center, Department of Radiology, Duke University, Durham, NC (United States); Kammerman, Jeff [Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Driehuys, Bastiaan [Center for In Vivo Microscopy, Duke University, Durham, NC (United States); Schiebler, Mark L. [Department of Radiology, University of Wisconsin, Madison, WI (United States); Cadman, Robert V. [Department of Medical Physics, University of Wisconsin, Madison, WI (United States); Fain, Sean B., E-mail: sfain@wisc.edu [Departments of Medical Physics, Radiology, and Biomedical Engineering, University of Wisconsin, Madison, WI (United States)

    2017-01-15

    Highlights: • Recent advances in hyperpolarized 129Xe MRI are reviewed. • Xenon MRI allows for functional imaging of ventilation, diffusion, and gas exchange. • Xenon’s unique gas exchange imaging capabilities are highlighted. • Applications to obstructive and restrictive lung diseases are presented. • These advances are ready for translation to clinical applications. - Abstract: In the last two decades, functional imaging of the lungs using hyperpolarized noble gases has entered the clinical stage. Both helium ({sup 3}He) and xenon ({sup 129}Xe) gas have been thoroughly investigated for their ability to assess both the global and regional patterns of lung ventilation. With advances in polarizer technology and the current transition towards the widely available {sup 129}Xe gas, this method is ready for translation to the clinic. Currently, hyperpolarized (HP) noble gas lung MRI is limited to selected academic institutions; yet, the promising results from initial clinical trials have drawn the attention of the pulmonary medicine community. HP {sup 129}Xe MRI provides not only 3-dimensional ventilation imaging, but also unique capabilities for probing regional lung physiology. In this review article, we aim to (1) provide a brief overview of current ventilation MR imaging techniques, (2) emphasize the role of HP {sup 129}Xe MRI within the array of different imaging strategies, (3) discuss the unique imaging possibilities with HP {sup 129}Xe MRI, and (4) propose clinical applications.

  5. A catalyzing phantom for reproducible dynamic conversion of hyperpolarized [1-¹³C]-pyruvate.

    Science.gov (United States)

    Walker, Christopher M; Lee, Jaehyuk; Ramirez, Marc S; Schellingerhout, Dawid; Millward, Steven; Bankson, James A

    2013-01-01

    In vivo real time spectroscopic imaging of hyperpolarized ¹³C labeled metabolites shows substantial promise for the assessment of physiological processes that were previously inaccessible. However, reliable and reproducible methods of measurement are necessary to maximize the effectiveness of imaging biomarkers that may one day guide personalized care for diseases such as cancer. Animal models of human disease serve as poor reference standards due to the complexity, heterogeneity, and transient nature of advancing disease. In this study, we describe the reproducible conversion of hyperpolarized [1-¹³C]-pyruvate to [1-¹³C]-lactate using a novel synthetic enzyme phantom system. The rate of reaction can be controlled and tuned to mimic normal or pathologic conditions of varying degree. Variations observed in the use of this phantom compare favorably against within-group variations observed in recent animal studies. This novel phantom system provides crucial capabilities as a reference standard for the optimization, comparison, and certification of quantitative imaging strategies for hyperpolarized tracers.

  6. A catalyzing phantom for reproducible dynamic conversion of hyperpolarized [1-¹³C]-pyruvate.

    Directory of Open Access Journals (Sweden)

    Christopher M Walker

    Full Text Available In vivo real time spectroscopic imaging of hyperpolarized ¹³C labeled metabolites shows substantial promise for the assessment of physiological processes that were previously inaccessible. However, reliable and reproducible methods of measurement are necessary to maximize the effectiveness of imaging biomarkers that may one day guide personalized care for diseases such as cancer. Animal models of human disease serve as poor reference standards due to the complexity, heterogeneity, and transient nature of advancing disease. In this study, we describe the reproducible conversion of hyperpolarized [1-¹³C]-pyruvate to [1-¹³C]-lactate using a novel synthetic enzyme phantom system. The rate of reaction can be controlled and tuned to mimic normal or pathologic conditions of varying degree. Variations observed in the use of this phantom compare favorably against within-group variations observed in recent animal studies. This novel phantom system provides crucial capabilities as a reference standard for the optimization, comparison, and certification of quantitative imaging strategies for hyperpolarized tracers.

  7. Hyperpolarized Amino Acid Derivatives as Multivalent Magnetic Resonance pH Sensor Molecules.

    Science.gov (United States)

    Hundshammer, Christian; Düwel, Stephan; Ruseckas, David; Topping, Geoffrey; Dzien, Piotr; Müller, Christoph; Feuerecker, Benedikt; Hövener, Jan B; Haase, Axel; Schwaiger, Markus; Glaser, Steffen J; Schilling, Franz

    2018-02-15

    pH is a tightly regulated physiological parameter that is often altered in diseased states like cancer. The development of biosensors that can be used to non-invasively image pH with hyperpolarized (HP) magnetic resonance spectroscopic imaging has therefore recently gained tremendous interest. However, most of the known HP-sensors have only individually and not comprehensively been analyzed for their biocompatibility, their pH sensitivity under physiological conditions, and the effects of chemical derivatization on their logarithmic acid dissociation constant (p K a ). Proteinogenic amino acids are biocompatible, can be hyperpolarized and have at least two pH sensitive moieties. However, they do not exhibit a pH sensitivity in the physiologically relevant pH range. Here, we developed a systematic approach to tailor the p K a of molecules using modifications of carbon chain length and derivatization rendering these molecules interesting for pH biosensing. Notably, we identified several derivatives such as [1- 13 C]serine amide and [1- 13 C]-2,3-diaminopropionic acid as novel pH sensors. They bear several spin-1/2 nuclei ( 13 C, 15 N, 31 P) with high sensitivity up to 4.8 ppm/pH and we show that 13 C spins can be hyperpolarized with dissolution dynamic polarization (DNP). Our findings elucidate the molecular mechanisms of chemical shift pH sensors that might help to design tailored probes for specific pH in vivo imaging applications.

  8. Biochemical and structural analysis of the hyperpolarization-activated K(+) channel MVP.

    Science.gov (United States)

    Randich, Amelia M; Cuello, Luis G; Wanderling, Sherry S; Perozo, Eduardo

    2014-03-18

    In contrast to the majority of voltage-gated ion channels, hyperpolarization-activated channels remain closed at depolarizing potentials and are activated at hyperpolarizing potentials. The basis for this reverse polarity is thought to be a result of differences in the way the voltage-sensing domain (VSD) couples to the pore domain. In the absence of structural data, the molecular mechanism of this reverse polarity coupling remains poorly characterized. Here we report the characterization of the structure and local dynamics of the closed activation gate (lower S6 region) of MVP, a hyperpolarization-activated potassium channel from Methanococcus jannaschii, by electron paramagnetic resonance (EPR) spectroscopy. We show that a codon-optimized version of MVP has high expression levels in Escherichia coli, is purified as a stable tetramer, and exhibits expected voltage-dependent activity when reconstituted in liposomes. EPR analysis of the mid to lower S6 region revealed positions exhibiting strong spin-spin coupling, indicating that the activation gate of MVP is closed at 0 mV. A comparison of local environmental parameters along the activation gate for MVP and KcsA indicates that MVP adopts a different closed conformation. These structural details set the stage for future evaluations of reverse electromechanical coupling in MVP.

  9. Biochemical and Structural Analysis of the Hyperpolarization-Activated K+ Channel MVP

    Science.gov (United States)

    2015-01-01

    In contrast to the majority of voltage-gated ion channels, hyperpolarization-activated channels remain closed at depolarizing potentials and are activated at hyperpolarizing potentials. The basis for this reverse polarity is thought to be a result of differences in the way the voltage-sensing domain (VSD) couples to the pore domain. In the absence of structural data, the molecular mechanism of this reverse polarity coupling remains poorly characterized. Here we report the characterization of the structure and local dynamics of the closed activation gate (lower S6 region) of MVP, a hyperpolarization-activated potassium channel from Methanococcus jannaschii, by electron paramagnetic resonance (EPR) spectroscopy. We show that a codon-optimized version of MVP has high expression levels in Escherichia coli, is purified as a stable tetramer, and exhibits expected voltage-dependent activity when reconstituted in liposomes. EPR analysis of the mid to lower S6 region revealed positions exhibiting strong spin–spin coupling, indicating that the activation gate of MVP is closed at 0 mV. A comparison of local environmental parameters along the activation gate for MVP and KcsA indicates that MVP adopts a different closed conformation. These structural details set the stage for future evaluations of reverse electromechanical coupling in MVP. PMID:24490868

  10. Imaging Human Brain Perfusion with Inhaled Hyperpolarized 129Xe MR Imaging.

    Science.gov (United States)

    Rao, Madhwesha R; Stewart, Neil J; Griffiths, Paul D; Norquay, Graham; Wild, Jim M

    2018-02-01

    Purpose To evaluate the feasibility of directly imaging perfusion of human brain tissue by using magnetic resonance (MR) imaging with inhaled hyperpolarized xenon 129 ( 129 Xe). Materials and Methods In vivo imaging with 129 Xe was performed in three healthy participants. The combination of a high-yield spin-exchange optical pumping 129 Xe polarizer, custom-built radiofrequency coils, and an optimized gradient-echo MR imaging protocol was used to achieve signal sensitivity sufficient to directly image hyperpolarized 129 Xe dissolved in the human brain. Conventional T1-weighted proton (hydrogen 1 [ 1 H]) images and perfusion images by using arterial spin labeling were obtained for comparison. Results Images of 129 Xe uptake were obtained with a signal-to-noise ratio of 31 ± 9 and demonstrated structural similarities to the gray matter distribution on conventional T1-weighted 1 H images and to perfusion images from arterial spin labeling. Conclusion Hyperpolarized 129 Xe MR imaging is an injection-free means of imaging the perfusion of cerebral tissue. The proposed method images the uptake of inhaled xenon gas to the extravascular brain tissue compartment across the intact blood-brain barrier. This level of sensitivity is not readily available with contemporary MR imaging methods. © RSNA, 2017.

  11. The role of hyperpolarized 129xenon in MR imaging of pulmonary function

    International Nuclear Information System (INIS)

    Ebner, Lukas; Kammerman, Jeff; Driehuys, Bastiaan; Schiebler, Mark L.; Cadman, Robert V.; Fain, Sean B.

    2017-01-01

    Highlights: • Recent advances in hyperpolarized 129Xe MRI are reviewed. • Xenon MRI allows for functional imaging of ventilation, diffusion, and gas exchange. • Xenon’s unique gas exchange imaging capabilities are highlighted. • Applications to obstructive and restrictive lung diseases are presented. • These advances are ready for translation to clinical applications. - Abstract: In the last two decades, functional imaging of the lungs using hyperpolarized noble gases has entered the clinical stage. Both helium ( 3 He) and xenon ( 129 Xe) gas have been thoroughly investigated for their ability to assess both the global and regional patterns of lung ventilation. With advances in polarizer technology and the current transition towards the widely available 129 Xe gas, this method is ready for translation to the clinic. Currently, hyperpolarized (HP) noble gas lung MRI is limited to selected academic institutions; yet, the promising results from initial clinical trials have drawn the attention of the pulmonary medicine community. HP 129 Xe MRI provides not only 3-dimensional ventilation imaging, but also unique capabilities for probing regional lung physiology. In this review article, we aim to (1) provide a brief overview of current ventilation MR imaging techniques, (2) emphasize the role of HP 129 Xe MRI within the array of different imaging strategies, (3) discuss the unique imaging possibilities with HP 129 Xe MRI, and (4) propose clinical applications.

  12. A Bacterial Toxin with Analgesic Properties: Hyperpolarization of DRG Neurons by Mycolactone.

    Science.gov (United States)

    Song, Ok-Ryul; Kim, Han-Byul; Jouny, Samuel; Ricard, Isabelle; Vandeputte, Alexandre; Deboosere, Nathalie; Marion, Estelle; Queval, Christophe J; Lesport, Pierre; Bourinet, Emmanuel; Henrion, Daniel; Oh, Seog Bae; Lebon, Guillaume; Sandoz, Guillaume; Yeramian, Edouard; Marsollier, Laurent; Brodin, Priscille

    2017-07-18

    Mycolactone, a polyketide molecule produced by Mycobacterium ulcerans , is the etiological agent of Buruli ulcer. This lipid toxin is endowed with pleiotropic effects, presents cytotoxic effects at high doses, and notably plays a pivotal role in host response upon colonization by the bacillus. Most remarkably, mycolactone displays intriguing analgesic capabilities: the toxin suppresses or alleviates the pain of the skin lesions it inflicts. We demonstrated that the analgesic capability of mycolactone was not attributable to nerve damage, but instead resulted from the triggering of a cellular pathway targeting AT₂ receptors (angiotensin II type 2 receptors; AT₂R), and leading to potassium-dependent hyperpolarization. This demonstration paves the way to new nature-inspired analgesic protocols. In this direction, we assess here the hyperpolarizing properties of mycolactone on nociceptive neurons. We developed a dedicated medium-throughput assay based on membrane potential changes, and visualized by confocal microscopy of bis-oxonol-loaded Dorsal Root Ganglion (DRG) neurons. We demonstrate that mycolactone at non-cytotoxic doses triggers the hyperpolarization of DRG neurons through AT₂R, with this action being not affected by known ligands of AT₂R. This result points towards novel AT₂R-dependent signaling pathways in DRG neurons underlying the analgesic effect of mycolactone, with the perspective for the development of new types of nature-inspired analgesics.

  13. Acute hypertensive stress imaged by cardiac hyperpolarized [1-C]pyruvate magnetic resonance

    DEFF Research Database (Denmark)

    Tougaard, Rasmus Stilling; Hansen, Esben Søvsø Szocska; Laustsen, Christoffer

    2018-01-01

    PURPOSE: Deranged metabolism is now recognized as a key causal factor in a variety of heart diseases, and is being studied extensively. However, invasive methods may alter metabolism, and conventional imaging techniques measure tracer uptake but not downstream metabolism. These challenges may...... be overcome by hyperpolarized MR, a noninvasive technique currently crossing the threshold into human trials. The aim of this study was to image metabolic changes in the heart in response to endogastric glucose bolus and to acute hypertension. METHODS: Five postprandial pigs were scanned with hyperpolarized.......008) and ejection fraction decreased from 54 ± 2% to 47 ± 6% (P = 0.03) The hemodynamic changes were accompanied by increases in the hyperpolarized [1-13C]pyruvate MR derived ratios of lactate/alanine (from 0.58 ± 0.13 to 0.78 ± 0.06, P = 0.03) and bicarbonate/alanine (from 0.55 ± 0.12 to 0.91 ± 0.14, P = 0...

  14. Echo-planar MR imaging of dissolved hyperpolarized 129Xe. Potential for M angiography

    International Nuclear Information System (INIS)

    Maansson, S.

    2002-01-01

    Purpose: The feasibility of hyperpolarized 129 Xe for fast MR angiography (MRA) was evaluated using the echo-planar imaging (EPI) technique. Material and Methods: Hyperpolarized Xe gas was dissolved in ethanol; a carrier agent with high solubility for Xe (Ostwald solubility coefficient 2.5) and long relaxation times. The dissolved Xe was injected as a bolus into a flow phantom where the mean flow velocity was 15 cm/s. Ultrafast EPI images with 44 ms scan time were acquired of the flowing bolus and the signal-to-noise ratios (SNR) were measured. Results: The relaxation times of hyperpolarized Xe in ethanol were measured to T1=160±11 s and T2 ≅ 20 s. The resulting images of the flowing liquid were of reasonable quality and had an SNR of about 70. Conclusion: Based on the SNR of the obtained Xe EPI images; it was estimated that rapid in vivo MRA with 129 Xe may be feasible; provided that an efficient; biologically acceptable carrier for Xe can be found and polarization levels of more than 25% can be achieved in isotopically enriched 129 Xe

  15. Electrocatalytic reduction of nitrate at low concentration on coinage and transition-metal electrodes in acid solutions

    NARCIS (Netherlands)

    Dima, G.E.; Vooys, de A.C.A.; Koper, M.T.M.

    2003-01-01

    A comparative study was performed to determine the reactivity of nitrate ions at 0.1 M on eight different polycrystalline electrodes (platinum, palladium, rhodium, ruthenium, iridium, copper, silver and gold) in acidic solution using cyclic voltammetry (CV), chronoamperometry and differential

  16. Br2 production from the heterogeneous reaction of gas-phase OH with aqueous salt solutions: Impacts of acidity, halide concentration, and organic surfactants.

    Science.gov (United States)

    Frinak, Elizabeth K; Abbatt, Jonathan P D

    2006-09-07

    This study reports the first laboratory measurement of gas-phase Br2 production from the reaction between gas-phase hydroxyl radicals and aqueous salt solutions. Experiments were conducted at 269 K in a rotating wetted-wall flow tube coupled to a chemical-ionization mass spectrometer for analysis of gas-phase components. From both pure NaBr solutions and mixed NaCl/NaBr solutions, the amount of Br2 released was found to increase with increasing acidity, whereas it was found to vary little with increasing concentration of bromide ions in the sample. For mixed NaCl/NaBr solutions, Br2 was formed preferentially over Cl2 unless the Br- levels in the solution were significantly depleted by OH oxidation, at which point Cl2 formation was observed. Presence of a surfactant in solution, sodium dodecyl sulfate, significantly suppressed the formation of Br2; this is the first indication that an organic surfactant can affect the rate of interfacial mass transfer of OH to an aqueous surface. The OH-mediated oxidation of bromide may serve as a source of active bromine in the troposphere and contribute to the subsequent destruction of ozone that proceeds in marine-influenced regions of the troposphere.

  17. Effect of Nutrient Solution Concentration, Time and Frequency of Foliar Application on Growth of Leaf and Daughter Corms of Saffron (Crocus sativus L.

    Directory of Open Access Journals (Sweden)

    R Khorasani

    2015-07-01

    Full Text Available In order to investigate the effect of different levels of nutrient solution concentration and times and frequencies of foliar applications on dry weight, nitrogen, phosphorus and potassium concentrations of leaf and corm of saffron, a pot experiment was conducted as a completely randomized design with factorial arrangement and three replications under open door conditions in research garden of ferdowsi university, faculty of agriculture. The experimental treatments were included 4 levels of solution concentration (0, 4, 8 and 12 per 1000 and 7 levels of time and frequency of foliar applications (F1: foliar application on 3th February, F2: foliar application on 18th February, F3: foliar application on 5th March, F4: foliar applications on 3th and 18th February, F5: foliar applications on 3th February and 5th March, F6: foliar applications on 18th February and 5th March, F7: foliar applications on 3th and 18th February and 5th March. Results of variance analysis showed that fresh and dry weight of corm and leaf were not influenced by concentration, time and frequency of foliar applications. Also, comparison of nitrogen, phosphorus and potassium concentrations of leaf and corm showed that there was no significant difference between levels of foliar treatments and control. Therefore, it seems that due attention to pattern of leaf and low nutrient demand of saffron, foliar applications in different levels of nutrient solution concentrations and times and frequencies of foliar applications could not increase vegetative growth and consequently, could not improve the growth and nutritional properties of saffron corms.

  18. Some particularities of impurity center structure in concentrated solid solutions MeF2-GdF3, where Me-Ca2+, Sr2+ and Ba2+

    International Nuclear Information System (INIS)

    Karelin, V.V.; Orlov, Yu.N.; Bozhevol'nov, V.E.; Ivanov, L.N.

    1981-01-01

    The monocrystalline CaF 2 -GdF 3 , SrF 2 -GdF 3 and BaF 2 -GdF 3 systems are studied using the methods of EPR, photo-, radio-, cathode- and thermoluminescence. It is shown that the structure of fluorite solid solutions changes considerably with the growth of the rare earth component concentration. At that, in the systems investigated at least three concentration regions can be singled out: (up to 1%; from 1 to 15%, and > 15% GdF 3 ) which are characterized by their certain selection of impurity centres [ru

  19. Determination of the activity concentration of a 238 Pu solution by the defined solid angle method utilizing a novel dual diaphragm-detector assembly.

    Science.gov (United States)

    Aguiar, Julio C; Galiano, Eduardo; Arenillas, Pablo

    2005-08-01

    The activity concentration of a (238)Pu solution was measured by the determined solid angle method employing a novel dual diaphragm-detector assembly, which has been previously described. Due to the special requirements of the detector, a new type of source holder was developed, which consisted of sandwiching the radioisotope between two organic films called VYNS. It was experimentally demonstrated that the VYNS films do not absorb alpha particles, but reduce their energy by an average of 22 keV.A mean activity concentration for (238)Pu of 359.10+/-0.8 kBq/g was measured.

  20. Determination of the activity concentration of a {sup 238}Pu solution by the defined solid angle method utilizing a novel dual diaphragm-detector assembly

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Julio C. [Departamento de Postgrado, Universidad Tecnologica Nacional, Buenos Aires (Argentina); Galiano, Eduardo [Departament of Physics, Laurentian University, Sudbury, Ont. P3E 2C6 (Canada)]. E-mail: egalianoriveros@laurentian.ca; Arenillas, Pablo [Comision Nacional de Energia Atomica, CAE, Laboratorio de Metrologia de Radioisotopos, Buenos Aires (Argentina)

    2005-08-01

    The activity concentration of a {sup 238}Pu solution was measured by the determined solid angle method employing a novel dual diaphragm-detector assembly, which has been previously described. Due to the special requirements of the detector, a new type of source holder was developed, which consisted of sandwiching the radioisotope between two organic films called VYNS. It was experimentally demonstrated that the VYNS films do not absorb {alpha} particles, but reduce their energy by an average of 22keV.A mean activity concentration for {sup 238}Pu of 359.10+/-0.8kBq/g was measured.

  1. Determination of the activity concentration of a 238Pu solution by the defined solid angle method utilizing a novel dual diaphragm-detector assembly

    International Nuclear Information System (INIS)

    Aguiar, Julio C.; Galiano, Eduardo; Arenillas, Pablo

    2005-01-01

    The activity concentration of a 238 Pu solution was measured by the determined solid angle method employing a novel dual diaphragm-detector assembly, which has been previously described. Due to the special requirements of the detector, a new type of source holder was developed, which consisted of sandwiching the radioisotope between two organic films called VYNS. It was experimentally demonstrated that the VYNS films do not absorb α particles, but reduce their energy by an average of 22keV.A mean activity concentration for 238 Pu of 359.10+/-0.8kBq/g was measured

  2. Effect of the Precursor Solution Concentration of CuI Thin Film Deposited By Spin Coating Method

    International Nuclear Information System (INIS)

    Nur Amalina Muhmmad; Atiq, A.M.; Rusop, M.

    2011-01-01

    Copper (I) Iodide is a p-type semiconductor with bandgap of 3.1 eV. It is water insoluble solid with three crystalline phases α, β, γ. In this research, the effect of precursor concentration of CuI thin film deposited by spin coating method was studied. The wide band gap p type semiconductor CuI thin film was prepared by mixing the CuI powder (ALDRICH, 98 %) with 50 ml of acetonitrile as a solvent. The CuI concentration varies from 0.025 M to 0.5 M. The speed for spin coating is 1000 rpm for 60 seconds. After the deposition the CuI thin films were annealed at 150 degree Celsius. The electrical and optical properties were characterized by current-voltage (I-V) measurement using Solar Simulator (Bukoh Keiki EP-2000) and ultraviolet visible- near infrared (UV-VIS-NIR) measurement (Jasco V-670). The result shows the CuI thin film properties strongly depends on its precursor concentration. Thickness between 33.65 nm - 441.25 nm was obtained as the concentration increases. The increment of thickness affects the electrical properties which is the resistivity and conductivity of CuI thin film. For optical properties, the transmittance decreases with high concentration as high amount of CuI particle were observed in the thin films. From the transmittance, the absorption coefficient and optical band gap of CuI was determined using Taucs plot. (author)

  3. Alkali solution extraction of rice residue protein isolates: Influence of alkali concentration on protein functional, structural properties and lysinoalanine formation.

    Science.gov (United States)

    Hou, Furong; Ding, Wenhui; Qu, Wenjuan; Oladejo, Ayobami Olayemi; Xiong, Feng; Zhang, Weiwei; He, Ronghai; Ma, Haile

    2017-03-01

    This study evaluated the nutrient property and safety of the rice residue protein isolates (RRPI) product (extracted by different alkali concentrations) by exploring the protein functional, structural properties and lysinoalanine (LAL) formation. The results showed that with the rising of alkali concentration from 0.03M to 0.15M, the solubility, emulsifying and foaming properties of RRPI increased at first and then descended. When the alkali concentration was greater than 0.03M, the RRPI surface hydrophobicity decreased and the content of thiol and disulfide bond, Lys and Cys significantly reduced. By the analysis of HPLC, the content of LAL rose up from 276.08 to 15,198.07mg/kg and decreased to 1340.98mg/kg crude protein when the alkali concentration increased from 0.03 to 0.09M and until to 0.15M. These results indicated that RRPI alkaline extraction concentration above 0.03M may cause severe nutrient or safety problems of protein. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Electrodeposition of ZnO from DMSO solution: influence of anion nature and its concentration in the nucleation and growth mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Riveros, Gonzalo; Ramirez, Daniel, E-mail: gonzalo.riveros@uv.cl [Departamento de Quimica y Bioquimica, Facultad de Ciencias, Universidad de Valparaiso, Valparaiso (Chile); Tello, Alejandra; Schrebler, Ricardo; Henriquez, Rodrigo; Gomez, Humberto [Instituto de Quimica, Pontificia Universidad Catolica de Valparaiso, Curauma, Valparaiso (Chile)

    2012-03-15

    The influence of the anion nature and its concentration in the electrodeposition of ZnO onto a gold electrode from dimethylsulfoxide (DMSO) solutions was studied. Voltammetric experiments revealed important changes in the zinc oxide electrodeposition process depending on the employed anion as electrolyte. From chronoamperometric experiments, the corresponding current-time curves were fitted with different nucleation and growth mechanism models. The analysis of these results showed changes from an instantaneous to a progressive growth when the solution composition was changed from ZnCl{sub 2} to ZnCl{sub 2} + LiCl. The change of the mechanism is associated to the adsorption of chloride ion on the active sites of the electrode surface when LiCl is present in the solution. (author)

  5. Concentration dependences of the density, viscosity, and refraction index of Cu(NO3)2 · 3H2O solutions in DMSO at 298 K

    Science.gov (United States)

    Mamyrbekova, A. K.

    2013-03-01

    Physicochemical properties (density, dynamic viscosity, refraction index) of the DMSO-Cu(NO3)2 · 3H2O system are studied in the concentration range of 0.01-2 M at 298 K. The refraction index of a solution of copper(II) nitrate in dimethylsulfoxide (DMSO) is measured at 288-318 K. The excess and partial molar volumes of the solvent and dissolved substance are calculated analytically.

  6. The effect of temperature and concentration on the corrosion inhibition mechanism of an amphiphilic amido-amine in CO2 saturated solution

    International Nuclear Information System (INIS)

    Desimone, M.P.; Gordillo, G.; Simison, S.N.

    2011-01-01

    Highlights: → Behaviour of N-[2-[(2-aminoethyl)amino]ethyl]-9-octadecenamide (AAOA) as CO 2 corrosion inhibitor. → The adsorption of the AAOA corrosion inhibitor obeys a Frumkin adsorption isotherm. → The inhibition efficiency of the AAOA depends on temperature and concentration. → There is a change in the adsorption mode of the inhibitor with concentration. → AAOA is mainly physi- or chemisorbed for low or high concentrations, respectively. - Abstract: The corrosion inhibition mechanism of the N-[2-[(2-aminoethyl)amino]ethyl]-9-octadecenamide on mild steel surface in CO 2 -saturated 5% NaCl solution has been studied. The inhibition efficiency decreases with increasing temperature. Adsorption of the inhibitor studied is found to follow the Frumkin adsorption isotherm. EIS results show that the mechanism of its corrosion inhibition at concentrations higher than critical micelle concentration is by forming a protective porous bi-layer. The activation energy, thermodynamic parameters and electrochemical results reveal a change in the adsorption mode of the inhibitor studied: the inhibitor could primarily be physically adsorbed at low concentrations, while chemisorption is favoured as concentration increases.

  7. A New Approach to Look at the Electrical Conductivity of Streamflow: Decomposing a Bulk Signal to Recover Individual Solute Concentrations at High-Frequency

    Science.gov (United States)

    Benettin, P.; Van Breukelen, B. M.

    2017-12-01

    The ability to evaluate stream hydrochemistry is often constrained by the capacity to sample streamwater at an adequate frequency. While technology is no longer a limiting factor, economic and management efforts can still be a barrier to high-resolution water quality instrumentation. We propose a new framework to investigate the electrical conductivity (EC) of streamwater, which can be measured continuously through inexpensive sensors. We show that EC embeds information on ion content which can be isolated to retrieve solute concentrations at high resolution. The approach can already be applied to a number of datasets worldwide where water quality campaigns are conducted, provided continuous EC measurements can be collected. The essence of the approach is the decomposition of the EC signal into its "harmonics", i.e. the specific contributions of the major ions which conduct current in water. The ion contribution is used to explore water quality patterns and to develop algorithms that reconstruct solute concentrations during periods where solute measurements are not available. The approach is validated on a hydrochemical dataset from Plynlimon, Wales. Results show that the decomposition of EC is feasible and for at least two major elements the methodology provided improved estimates of high-frequency solute dynamics. Our results support the installation of EC probes to complement water quality campaigns and suggest that the potential of EC measurements in rivers is currently far from being fully exploited.

  8. Concentrated Aqueous Sodium Chloride Solution in Clays at Thermodynamic Conditions of Hydraulic Fracturing: Insight from Molecular Dynamics Simulations.

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Martin; Lísal, Martin

    2018-01-01

    Roč. 148, č. 22 (2018), č. článku 222806. ISSN 0021-9606 R&D Projects: GA ČR GA17-25100S EU Projects: European Commission(XE) 640979 - ShaleXenvironmenT Institutional support: RVO:67985858 Keywords : aqueous NaCl solutions * hydrogen bond networks * molecular dynamics simulations Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 2.965, year: 2016

  9. Concentration-discharge relationships during an extreme event: Contrasting behavior of solutes and changes to chemical quality of dissolved organic material in the Boulder Creek Watershed during the September 2013 flood: SOLUTE FLUX IN A FLOOD EVENT

    Energy Technology Data Exchange (ETDEWEB)

    Rue, Garrett P. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA; Rock, Nathan D. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA; Gabor, Rachel S. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA; Pitlick, John [Department of Geography, University of Colorado, Boulder Colorado USA; Tfaily, Malak [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland Washington USA; McKnight, Diane M. [Institute of Arctic and Alpine Research, University of Colorado, Boulder Colorado USA

    2017-07-01

    During the week of September 10-17, 2013, close to 20 inches of rain fell across Boulder County, Colorado, USA. This rainfall represented a 1000-year event that caused massive hillslope erosion, landslides, and mobilization of sediments. The resultant stream flows corresponded to a 100-year flood. For the Boulder Creek Critical Zone Observatory (BC-CZO), this event provided an opportunity to study the effect of extreme rainfall on solute concentration-discharge relationships and biogeochemical catchment processes. We observed base cation and dissolved organic carbon (DOC) concentrations at two sites on Boulder Creek following the recession of peak flow. We also isolated three distinct fractions of dissolved organic matter (DOM) for chemical characterization. At the upper site, which represented the forested mountain catchment, the concentrations of the base cations Ca, Mg and Na were greatest at the peak flood and decreased only slightly, in contrast with DOC and K concentrations, which decreased substantially. At the lower site within urban corridor, all solutes decreased abruptly after the first week of flow recession, with base cation concentrations stabilizing while DOC and K continued to decrease. Additionally, we found significant spatiotemporal trends in the chemical quality of organic matter exported during the flood recession, as measured by fluorescence, 13C-NMR spectroscopy, and FTICR-MS. Similar to the effect of extreme rainfall events in driving landslides and mobilizing sediments, our findings suggest that such events mobilize solutes by the flushing of the deeper layers of the critical zone, and that this flushing regulates terrestrial-aquatic biogeochemical linkages during the flow recession.

  10. Influence of irradiation time and solution concentration on the photochemical degradation of EDDHA/Fe3+: effect of its photodecomposition products on soybean growth.

    Science.gov (United States)

    Hernández-Apaolaza, Lourdes; Lucena, Juan J

    2011-08-30

    Ethylenediamine-N, N'-bis(2-hydroxyphenylacetic acid (EDDHA) is one of the most efficient iron-chelating agents employed to relieve iron chlorosis in plants. It has been well known for decades that this compound is photosensitive, but in spite of this fact its degradation pathways are virtually unknown. The aim of this work was to evaluate how the length of sunlight exposure and the concentration of irradiated EDDHA/Fe(3+) solutions influence the photostability of the chelate at constant pH. Moreover, the possible toxic effect of the chelate photodegradation products, elsewhere proposed, on soybean growth has been tested. The photodecomposition of the chelate increased as the time of sunlight exposure increased, and resulted in a partial decomposition of the organic ligand. Moreover, EDDHA/Fe(3+) photodecomposition was highly correlated with the concentration of solution exposed. Plants did not present differences in recovery from chlorosis among treatments with and without decomposition products. EDDHA/Fe(3+) undergoes photodegradation, like other aminopolycarboxylic acids, being more degraded as solution concentration decreases and exposure time increases. The photodecomposition products salicylic acid, salicylaldehide and Salicylaldehyde ethylenediamine diimine tested did not have negative effects on soybean growth, at least in the short-term hydroponic experimental design tested. Copyright © 2011 Society of Chemical Industry.

  11. Effect of precursor solutions stirring on deep level defects concentration and spatial distribution in low temperature aqueous chemical synthesis of zinc oxide nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Alnoor, Hatim, E-mail: hatim.alnoor@liu.se; Chey, Chan Oeurn; Pozina, Galia; Willander, Magnus; Nur, Omer [Department of Science and Technology (ITN), Campus Norrköping, Linköping University, SE-601 74 Norrköping (Sweden); Liu, Xianjie; Khranovskyy, Volodymyr [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-583 81 Linköping (Sweden)

    2015-08-15

    Hexagonal c-axis oriented zinc oxide (ZnO) nanorods (NRs) with 120-300 nm diameters are synthesized via the low temperature aqueous chemical route at 80 °C on silver-coated glass substrates. The influence of varying the precursor solutions stirring durations on the concentration and spatial distributions of deep level defects in ZnO NRs is investigated. Room temperature micro-photoluminesnce (μ-PL) spectra were collected for all samples. Cathodoluminescence (CL) spectra of the as-synthesized NRs reveal a significant change in the intensity ratio of the near band edge emission (NBE) to the deep-level emission (DLE) peaks with increasing stirring durations. This is attributed to the variation in the concentration of the oxygen-deficiency with increasing stirring durations as suggested from the X-ray photoelectron spectroscopy analysis. Spatially resolved CL spectra taken along individual NRs revealed that stirring the precursor solutions for relatively short duration (1-3 h), which likely induced high super saturation under thermodynamic equilibrium during the synthesis process, is observed to favor the formation of point defects moving towards the tip of the NRs. In contrary, stirring for longer duration (5-15 h) will induce low super saturation favoring the formation of point defects located at the bottom of the NRs. These findings demonstrate that it is possible to control the concentration and spatial distribution of deep level defects in ZnO NRs by varying the stirring durations of the precursor solutions.

  12. Influence of ionic strength and OH(-) ion concentration on the Cu(II) complex formation with EDTA in alkaline solutions.

    Science.gov (United States)

    Norkus, E; Vaskelis, A; Zakaite, I

    1996-03-01

    D.c. polarographic data show that the complex formation of copper ions with EDTA depends markedly on the ionic strength of the solution at pH 8-10. This is primarily associated with the dependence of the fourth deprotonization constant of EDTA on the solution ionic strength: when it increases from 0.4 to 3.4, the pK(a4) value decreases from 9.5 to 8.2. According to polarographic and spectrophotometric data the degree of Cu(II) complexation increases at pH>10 due to transformation of the complex CuY(2-) to the more stable CuY(OH)(3-) (Y(4-), a fully deprotonized anion of EDTA), but it decreases with increase in alkalinity in a highly alkaline solution (pH>13.5). The latter result could be explained by the decrease in the EDTA anion activity. The calculated values of the activity coefficient are lower than 0.05 at pH>14.

  13. Influence of calcium chelators on concentrated micellar casein solutions : from micellar structure to viscosity and heat stability

    NARCIS (Netherlands)

    Kort, de E.J.P.

    2012-01-01

    In practice it is challenging to prepare a concentrated medical product with high heat stability
    and low viscosity. Calcium chelators are often added to dairy products to improve heat stability,
    but this may increase viscosity through interactions with the casein proteins. The aim of

  14. Determination of trace concentrations of chlorine in aqueous solutions by high-resolution continuum source graphite furnace molecular absorption spectrometry

    Science.gov (United States)

    Machyňák, Ľubomír; Čacho, František; Němeček, Martin; Beinrohr, Ernest

    2016-11-01

    Trace concentrations of total chlorine were determined by means of molecular absorption of indium mono-chloride (InCl) at 267.217 nm using high-resolution continuum source graphite furnace molecular absorption spectrometry. The effects of chemical modifiers and the amount of In on the sensitivity and accuracy were investigated. The optimum pyrolysis and vaporization temperatures were 600 °C and 1400 °C, respectively. The limit of detection and characteristic mass were found to be 0.10 ng and 0.21 ng, respectively. Potential non-spectral and spectral interferences were tested for various metals and non-metals at concentrations up to 50 mg L- 1 and for phosphoric, sulphuric and nitric acids. No spectral interferences were observed. Significant non-spectral interferences were observed with F, Br, and I at concentrations higher than 1 mg L- 1, 5 mg L- 1 and 25 mg L- 1, respectively, which is probably caused by formation of competitive indium halogen molecules. Higher concentrations of mineral acids depressed the signal owing to the formation of volatile HCl. The calibration curve was linear in the range between 0.3 and 10 ng with a correlation coefficient of R = 0.993. The elaborated method was used for the chlorine determination in various waters and a drug sample.

  15. On large-time energy concentration in solutions to the Navier-Stokes equations in general domains

    Czech Academy of Sciences Publication Activity Database

    Skalák, Zdeněk

    2011-01-01

    Roč. 91, č. 9 (2011), s. 724-732 ISSN 0044-2267 R&D Projects: GA AV ČR IAA100190905 Institutional research plan: CEZ:AV0Z20600510 Keywords : Navier-Stokes equations * large-time behavior * energy concentration Subject RIV: BA - General Mathematics Impact factor: 0.863, year: 2011

  16. Removal of high concentration p-nitrophenol in aqueous solution by zero valent iron with ultrasonic irradiation (US–ZVI)

    International Nuclear Information System (INIS)

    Lai, Bo; Chen, Zhaoyu; Zhou, Yuexi; Yang, Ping; Wang, Juling; Chen, Zhiqiang

    2013-01-01

    Highlights: ► High concentration PNP can be reduced into the nontoxic p-aminophenol by US–ZVI. ► High removal efficiency of PNP is resulted from the synergistic reaction of ZVI and US. ► The reaction pathway of PNP in the US–ZVI system is proposed. ► Processing parameters of the US–ZVI system were optimized seriously. -- Abstract: In this study, the US–ZVI system was used to produce the strong reductants including ·H and nascent Fe 2+ ions to eliminate the toxicity of the high concentration p-nitrophenol (PNP) wastewater. The effect of the reactor structure, initial pH, ZVI dosage, ultrasonic power and initial PNP concentration on the removal efficiency of PNP from water was investigated intensively. The results show that a higher removal rate can be obtained by using a conical structure reactor, and the lower initial pH can aid the acceleration of PNP removal rate by using US–ZVI system. Furthermore, the removal efficiencies of PNP increased obviously with the increase of initial ZVI concentration from 0 to 15 g L −1 . Also, the treatment capacity of ZVI was enhanced remarkably by the ultrasonic irradiation, and the US–ZVI system can maintain high treatment efficiency for the high concentration PNP wastewater (500–10,000 mg L −1 ). Meanwhile, the high removal efficiency of PNP was mainly resulted from the synergistic reaction of ZVI and US. At last, the main degradation product (i.e., p-aminophenol) was detected by gas chromatography–mass spectrum (GC–MS). Thus, the reaction pathway of PNP in the US–ZVI system is proposed as a reducing process by the ·H and nascent Fe 2+ ions

  17. Removal of high concentration p-nitrophenol in aqueous solution by zero valent iron with ultrasonic irradiation (US–ZVI)

    Energy Technology Data Exchange (ETDEWEB)

    Lai, Bo, E-mail: laibo1981@163.com [School of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Chen, Zhaoyu [School of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Zhou, Yuexi [Research Center of Water Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Yang, Ping [School of Architecture and Environment, Sichuan University, Chengdu 610065 (China); Wang, Juling [Research Center of Water Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Chen, Zhiqiang [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China)

    2013-04-15

    Highlights: ► High concentration PNP can be reduced into the nontoxic p-aminophenol by US–ZVI. ► High removal efficiency of PNP is resulted from the synergistic reaction of ZVI and US. ► The reaction pathway of PNP in the US–ZVI system is proposed. ► Processing parameters of the US–ZVI system were optimized seriously. -- Abstract: In this study, the US–ZVI system was used to produce the strong reductants including ·H and nascent Fe{sup 2+} ions to eliminate the toxicity of the high concentration p-nitrophenol (PNP) wastewater. The effect of the reactor structure, initial pH, ZVI dosage, ultrasonic power and initial PNP concentration on the removal efficiency of PNP from water was investigated intensively. The results show that a higher removal rate can be obtained by using a conical structure reactor, and the lower initial pH can aid the acceleration of PNP removal rate by using US–ZVI system. Furthermore, the removal efficiencies of PNP increased obviously with the increase of initial ZVI concentration from 0 to 15 g L{sup −1}. Also, the treatment capacity of ZVI was enhanced remarkably by the ultrasonic irradiation, and the US–ZVI system can maintain high treatment efficiency for the high concentration PNP wastewater (500–10,000 mg L{sup −1}). Meanwhile, the high removal efficiency of PNP was mainly resulted from the synergistic reaction of ZVI and US. At last, the main degradation product (i.e., p-aminophenol) was detected by gas chromatography–mass spectrum (GC–MS). Thus, the reaction pathway of PNP in the US–ZVI system is proposed as a reducing process by the ·H and nascent Fe{sup 2+} ions.

  18. Morphologies and separation characteristics of polyphenyl sulfone-based solvent resistant nanofiltration membranes: Effect of polymer concentration in casting solution and membrane pretreatment condition

    International Nuclear Information System (INIS)

    Sani, Nur Aimie Abdullah; Lau, Woei Jye; Ismail, Ahmad Fauzi

    2015-01-01

    The performance of polyphenylsulfone (PPSU) solvent resistant nanofiltration (SRNF)-based flat sheet membranes prepared from phase inversion method was investigated by varying the concentration of polymer in the dope solution and condition of membrane pretreatment process. The membrane properties were characterized by SEM, FTIR, AFM and contact angle goniometer, while their performance was evaluated by measuring methanol flux and rejection of different molecular weight of dyes (ranging from 269 to 1,470 g/mol) in methanol. The experimental results showed that the polymer concentration has great impact not only on the final membrane morphology but also its separation characteristics. Increasing polymer concentration from 17 to 25wt% tended to suppress finger-like structure and more pear-like pores were developed, causing methanol flux to decrease. This can be explained by the decrease in molecular weight cut off (MWCO) of the membrane prepared at high polymer concentration. With respect to the effect of membrane pretreatment conditions, the rejection of membrane was negatively affected with longer immersion period in methanol solution prior to filtration experiment. The variation in membrane rejection can be attributed to the rearrangement of the polymer chain, which results in membrane swelling and/or change of membrane surface hydrophilicity

  19. Morphologies and separation characteristics of polyphenyl sulfone-based solvent resistant nanofiltration membranes: Effect of polymer concentration in casting solution and membrane pretreatment condition

    Energy Technology Data Exchange (ETDEWEB)

    Sani, Nur Aimie Abdullah; Lau, Woei Jye; Ismail, Ahmad Fauzi [Universiti Teknologi Malaysia, Skudai (Malaysia)

    2015-04-15

    The performance of polyphenylsulfone (PPSU) solvent resistant nanofiltration (SRNF)-based flat sheet membranes prepared from phase inversion method was investigated by varying the concentration of polymer in the dope solution and condition of membrane pretreatment process. The membrane properties were characterized by SEM, FTIR, AFM and contact angle goniometer, while their performance was evaluated by measuring methanol flux and rejection of different molecular weight of dyes (ranging from 269 to 1,470 g/mol) in methanol. The experimental results showed that the polymer concentration has great impact not only on the final membrane morphology but also its separation characteristics. Increasing polymer concentration from 17 to 25wt% tended to suppress finger-like structure and more pear-like pores were developed, causing methanol flux to decrease. This can be explained by the decrease in molecular weight cut off (MWCO) of the membrane prepared at high polymer concentration. With respect to the effect of membrane pretreatment conditions, the rejection of membrane was negatively affected with longer immersion period in methanol solution prior to filtration experiment. The variation in membrane rejection can be attributed to the rearrangement of the polymer chain, which results in membrane swelling and/or change of membrane surface hydrophilicity.

  20. An investigation to compare the performance of methods for the determination of free acid in highly concentrated solutions of plutonium and uranium nitrate

    International Nuclear Information System (INIS)

    Crossley, D.

    1980-08-01

    An investigation has been carried out to compare the performance of the direct titration method and the indirect mass balance method, for the determination of free acid in highly concentrated solutions of uranium nitrate and plutonium nitrate. The direct titration of free acid with alkali is carried out in a fluoride medium to avoid interference from the hydrolysis of uranium or plutonium, while free acid concentration by the mass balance method is obtained by calculation from the metal concentration, metal valency state, and total nitrate concentration in a sample. The Gran plot end-point prediction technique has been used extensively in the investigation to gain information concerning the hydrolysis of uranium and plutonium in fluoride media and in other complexing media. The use of the Gran plot technique has improved the detection of the end-point of the free acid titration which gives an improvement in the precision of the determination. The experimental results obtained show that there is good agreement between the two methods for the determination of free acidity, and that the precision of the direct titration method in a fluoride medium using the Gran plot technique to detect the end-point is 0.75% (coefficient of variation), for a typical separation plant plutonium nitrate solution. The performance of alternative complexing agents in the direct titration method has been studied and is discussed. (author)

  1. Molar concentration-depth profiles at the solution surface of a cationic surfactant reconstructed with angle resolved X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Wang Chuangye; Morgner, Harald

    2011-01-01

    In the current work, we first reconstructed the molar fraction-depth profiles of cation and anion near the surface of tetrabutylammonium iodide dissolved in formamide by a refined calculation procedure, based on angle resolved X-ray photoelectron spectroscopy experiments. In this calculation procedure, both the transmission functions of the core levels and the inelastic mean free paths of the photoelectrons have been taken into account. We have evaluated the partial molar volumes of surfactant and solvent by the densities of such solutions with different bulk concentrations. With those partial molar volumes, the molar concentration-depth profiles of tetrabutylammonium ion and iodide ion were determined. The surface excesses of both surfactant ions were then achieved directly by integrating these depth profiles. The anionic molar concentration-depth profiles and surface excesses have been compared with their counterparts determined by neutral impact ion scattering spectroscopy. The comparisons exhibit good agreements. Being capable of determining molar concentration-depth profiles of surfactant ions by core levels with different kinetic energies may extend the applicable range of ARXPS in investigating solution surfaces.

  2. Physicochemical, bioactive, and sensory properties of persimmon-based ice cream: technique for order preference by similarity to ideal solution to determine optimum concentration.

    Science.gov (United States)

    Karaman, Safa; Toker, Ömer Said; Yüksel, Ferhat; Çam, Mustafa; Kayacier, Ahmed; Dogan, Mahmut

    2014-01-01

    In the present study, persimmon puree was incorporated into the ice cream mix at different concentrations (8, 16, 24, 32, and 40%) and some physicochemical (dry matter, ash, protein, pH, sugar, fat, mineral, color, and viscosity), textural (hardness, stickiness, and work of penetration), bioactive (antiradical activity and total phenolic content), and sensory properties of samples were investigated. The technique for order preference by similarity to ideal solution approach was used for the determination of optimum persimmon puree concentration based on the sensory and bioactive characteristics of final products. Increase in persimmon puree resulted in a decrease in the dry matter, ash, fat, protein contents, and viscosity of ice cream mix. Glucose, fructose, sucrose, and lactose were determined to be major sugars in the ice cream samples including persimmon and increase in persimmon puree concentration increased the fructose and glucose content. Better melting properties and textural characteristics were observed for the samples with the addition of persimmon. Magnesium, K, and Ca were determined to be major minerals in the samples and only K concentration increased with the increase in persimmon content. Bioactive properties of ice cream samples improved and, in general, acetone-water extracts showed higher bioactivity compared with ones obtained using methanol-water extracts. The technique for order preference by similarity to ideal solution approach showed that the most preferred sample was the ice cream containing 24% persimmon puree. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. Conversion electron Moessbauer study of low carbon steel polarized in aqueous sulfate solution containing sulfite in low concentration

    International Nuclear Information System (INIS)

    Vertes, Cs.; Lakatos-Varsanyi, M.; Vertes, A.; Kuzmann, E.; Meisel, W.; Guetlich, P.

    1992-01-01

    The passivation of low carbon steel was studied in aqueous solution of 0.5 M Na 2 SO 4 +0.001 M NaHSO 3 at pH=3.5 and 6.5. The found major components at pH=3.5 were: γ-FeOOH and Fe 3 C, and also FeSO 4 .H 2 O could be identified on the surface of the low carbon steel as a minor component. At pH=6.5, the passive film contained only amorphous iron(III)-oxide or oxyhydroxide. (orig.)

  4. Concentration dependence of transmission losses in UV-laser irradiated bovine α-, βH-, βL- and γ-crystallin solutions

    International Nuclear Information System (INIS)

    Hott, J.L.; Borkman, R.F.

    1993-01-01

    Experiments with calf lens protein fractions in aqueous buffer solutions at room temperature showed that β H -, β L - and γ-crystallin fractions became opaque following ultraviolet exposure at 308 nm, while the α-crystallin fraction remained transparent. Transmission loss, due to UV-irradiation, for all of the crystallin samples was studied in the concentration range of 0.1 mg/mL to 1.0 mg/mL, and for α- and γ-crystallin, in the range up to 5 mg/mL. With increased concentrations of β H -, β L -and γ-crystalline, the rate of opacification increased. However, with α-crystallin, the loss of transmission was negligible for all of the concentrations and irradiation times studied. Opacification of the crystallins was accompanied by formation of higher molecular weight insoluble proteins as detected by SDS-PAGE. (Author)

  5. Sucrose in the concentrated solution or the supercooled “State”: A review of caramelisation reactions and physical behaviour

    OpenAIRE

    Quintas, M. A. C.; Fundo, J. F.; Silva, C. L. M.

    2010-01-01

    Sucrose is probably one of the most studied molecules by food scientists, since it plays an important role as an ingredient or preserving agent in many formulations and technological processes. When sucrose is present in a product with a concentration near or greater than the saturation point—i.e. in the supercooled state—it possesses high potentialities for the food industry in areas as different as pastry industry, dairy and frozen desserts or films and coatings production. This paper prese...

  6. ARSENIC REMOVAL BY PHYTOFILTRATION AND SILICON TREATMENT : A POTENTIAL SOLUTION FOR LOWERING ARSENIC CONCENTRATIONS IN FOOD CROPS

    OpenAIRE

    Sandhi, Arifin

    2017-01-01

    Use of arsenic-rich groundwater for crop irrigation can increase the arsenic (As) content in food crops and act as a carcinogen, compromising human health. Using aquatic plant based phytofiltration is a potential eco-technique for removing arsenic from water. The aquatic moss species Warnstorfia fluitans grows naturally in mining areas in northern Sweden, where high concentrations of arsenic occur in lakes and rivers. This species was selected as a model for field, climate chamber and greenho...

  7. Highly concentrated collagen solutions leading to transparent scaffolds of controlled three-dimensional organizations for corneal epithelial cell colonization.

    Science.gov (United States)

    Tidu, Aurélien; Ghoubay-Benallaoua, Djida; Teulon, Claire; Asnacios, Sophie; Grieve, Kate; Portier, François; Schanne-Klein, Marie-Claire; Borderie, Vincent; Mosser, Gervaise

    2018-05-29

    This study aimed at controlling both the organization and the transparency of dense collagen scaffolds making use of the lyotropic mesogen properties of collagen. Cholesteric or plywood-like liquid crystal phases were achieved using mixtures of acetic and hydrochloric acids as solvents. The critical pH at which the switch between the two phases occurred was around pH = 3. The use of the two acids led to fibrillated collagen I scaffolds, whose visual aspect ranged from opaque to transparent. Rheological investigations showed that viscoelastic properties of the plywood-like solutions were optimized for molding due to faster recovery. They also confirmed the correlation between the elastic modulus and the diameter of collagen fibrils obtained after fibrillogenesis under ammonia vapor. Human corneal epithelial cells, grown from donor limbal explants, were cultured both on transparent plywood-like matrices and on human amniotic membranes for 14 days. The development of corneal epithelium and the preservation of epithelial stem cells were checked by optical microscopy, colony formation assay, immuno-fluorescence and quantitative polymerase chain reaction. A higher level of amplification of limbal stem cells was obtained with collagen matrices compared with amniotic membranes, showing the high biocompatibility of our scaffolds. We therefore suggest that collagen solutions presenting both plywood-like organization and transparency might be of interest for biomedical applications in ophthalmology.

  8. Prediction of ore fluid metal concentrations from solid solution concentrations in ore-stage calcite: Application to the Illinois-Kentucky and Central Tennessee Mississippi Valley-type districts

    Science.gov (United States)

    Smith-Schmitz, Sarah E.; Appold, Martin S.

    2018-03-01

    Knowledge of the concentrations of Zn and Pb in Mississippi Valley-type (MVT) ore fluids is fundamental to understanding MVT deposit origin. Most previous attempts to quantify the concentrations of Zn and Pb in MVT ore fluids have focused on the analysis of fluid inclusions. However, these attempts have yielded ambiguous results due to possible contamination from secondary fluid inclusions, interferences from Zn and Pb in the host mineral matrix, and uncertainties about whether the measured Zn and Pb signals represent aqueous solute or accidental solid inclusions entrained within the fluid inclusions. The purpose of the present study, therefore, was to try to determine Zn and Pb concentrations in MVT ore fluids using an alternate method that avoids these ambiguities by calculating Zn and Pb concentrations in MVT ore fluids theoretically based on their solid solution concentrations in calcite. This method was applied to the Illinois-Kentucky and Central Tennessee districts, which both contain ore-stage calcite. Experimental partition coefficient (D) values from Rimstidt et al. (1998) and Tsusue and Holland (1966), and theoretical thermodynamic distribution coefficient (KD) values were employed in the present study. Ore fluid concentrations of Zn were likely most accurately predicted by Rimstidt et al. (1998) D values, based on their success in predicting known fluid inclusion concentrations of Mg and Mn, and likely also most accurately predicted ore fluid concentrations of Fe. All four of these elements have a divalent ionic radius smaller than that of Ca2+ and form carbonate minerals with the calcite structure. For both the Illinois-Kentucky and the Central Tennessee district, predicted ore fluid Zn and Fe concentrations were on the order of up to 10's of ppm. Ore fluid concentrations of Pb could only be predicted using Rimstidt et al. (1998) D values. However, these concentrations are unlikely to be reliable, as predicted ore fluid concentrations of Sr and Ba

  9. Measurement of actinide concentration in solution samples from the NUCEF reprocessing facility by X-ray and low energy gamma-ray spectroscopy

    International Nuclear Information System (INIS)

    Howarth, P.J.A.; Uchiyama, Gunzo; Asakura, Toshihide; Sawada, Mutsumi; Hagiya, Hiromichi; Fujine, Sachio

    1999-01-01

    X-ray and low-energy gamma-ray spectroscopy has been used to measure actinide concentration within the backend nuclear fuel reprocessing research facility at NUCEF. Research on advanced reprocessing techniques at NUCEF is based on the PARC refinement of the PUREX process which aims to recover Am and Cm from the highly active waste stream and to control and partition Np and Tc. It is hoped that the PARC process will mitigate the environmental impact of the wastes and improve the economy of reprocessing. The main actinides for which assay is required are U, Pu, Np and Am and knowledge of these concentrations will enable the following to be determined: i.) evaluation of the distribution of actinides throughout the reprocessing facility ii.) verification of the simulated actinide distribution from chemical kinetic simulations of the PARC process and iii.) assurance of safety and control over migrant radioactive species. The research presented here shows that passive measurement of x-rays and low-energy gamma-rays from solution samples provides an accurate and non-destructive means for assaying the concentration. The measurement technique is based on the use of the characteristic low energy gamma-rays and internal conversion x-ray emission from actinides (11 keV to 22 keV). The x-ray emission is a few orders of magnitude more intense than the characteristic gamma-ray emission and can be easily detected from solutions. The experimental system described here can be used for solution monitoring to a minimum concentration of typically 10-6 M for Pu, 10-10 M for Am and 10-6 M for Np. (author)

  10. Desirable levels of exchangeable K and Ca and their concentration in the soil solution to reduce uptake of radioactive Cs by rice plants

    International Nuclear Information System (INIS)

    Sekimoto, Hitoshi; Yamada, Takashi; Hotsuki, Tomoe; Matsuzaki, Akio; Mimura, Tetsuro

    2014-01-01

    K in the soil solution can control the uptake of radioactive Cs by rice plants, but this control is not accomplished only by K; it is affected by other ionic species. It is therefore important to investigate uptake of radioactive Cs from the perspective of the concentration of major cations such as Ca in the soil solution and the levels of exchangeable cations in the soil. To clarify the effects of K and Ca in the soil solution and of the levels of soil exchangeable cations to prevent uptake of radioactive Cs, we conducted a pot experiment and field experiments in a paddy soil in 2011 and 2012. To reduce the uptake of radioactive Cs, it was necessary to achieve a K concentration in the soil solution of 0.5 mmol L"-"1, and a Ca concentration higher than 2 mmol L"-"1 based on the results of the pot experiment. In addition, we obtained the desirable levels of exchangeable cations and the cation exchange capacity (CEC) in the soil from previous reports and the results of our field experiments. On this basis, we propose the following threshold levels for exchangeable cations and CEC in the soil as a standard: 0.53 K cmol_c kg"-"1, 18.0 Ca cmol_c kg"-"1, 2.0 Mg cmol_c kg"-"1, i.e. 25 mg K_2O 100 g"-"1, 505 mg CaO 100 g"-"1, 40 Mg O mg 100 g"-"1, and a CEC of 30 cmol_c kg"-"1. Converting these values into the corresponding levels in the soil solution, we obtained concentrations of 0.71 mmol K L"-"1, 4.22 mmol Ca L"-"1, and 1.35 mmol Mg L"-"1. These levels are within the improving standard for fertility of paddy soils in Japan. Consequently, it will be necessary to improve the fertility of paddy soils to control the uptake of radioactive Cs by rice plants. (author)

  11. Hormones of thyroid gland in sera of rats treated with different dose of concentrated potassium iodine solutions

    Directory of Open Access Journals (Sweden)

    Marković Ljiljana

    2010-01-01

    Full Text Available Introduction Potassium iodine (KI is used as a drug therapy for treating numerous diseases such as small-vessel vasculitis, erythema nodosum, vasculitis nodularis, Sweet's syndrome, tuberculosis and granulomatosis, and for iodized salt. At the same time, KI can be harmful. Iodine intake may increase the frequency of thyroiditis in humans, and may induce the occurrence of experimental thyroiditis (ET in animals. Investigations on an experimental model for the examination of thyroiditis in Wistar rats have clearly showed morphological changes in the rat thyroid evoked by KI administration. Objective The purpose of this study was to compare the effects of low and high doses of KI on the thyroid gland of Wistar rats and determine the effect on hormone status (T4, T3 and TSH in this rat strain. Methods Two groups of rats from the Wistar strain were treated with a low iodine dose (225 μg/g BW and with a high iodine dose (675 μg/g BW of KI solutions. Untreated nonimmunized animals served as controls. The solution was administrated daily intraperitoneally during the period of 26 consecutive days. Results Monitoring hormone status (TSH, T3 and T4 and morphological changes it was found that therapeutic doses of KI applied in treatment induced the occurrence of experimental thyroiditis (chronic destructive Hashimoto's thyroiditis in humans and cell necrosis in animals not carrying a genetic susceptibility. Significant inflammatory changes were observed in rats treated with a high iodine dose. Conclusion The early iodine induced cell necrosis and inflammation in the nonimmunized animals without genetic susceptibility is a new experimental model of thyroiditis. .

  12. Effect of electrolyte valency, alginate concentration and pH on engineered TiO₂ nanoparticle stability in aqueous solution.

    Science.gov (United States)

    Loosli, Frédéric; Le Coustumer, Philippe; Stoll, Serge

    2015-12-01

    Agglomeration and disagglomeration processes are expected to play a key role on the fate of engineered nanoparticles in natural aquatic systems. These processes are investigated here in detail by studying first the stability of TiO2 nanoparticles in the presence of monovalent and divalent electrolytes at different pHs (below and above the point of zero charge of TiO2) and discussing the importance of specific divalent cation adsorption with the help of the DLVO theory as well as the importance of the nature of the counterions. Then the impact of one polysaccharide (alginate) on the stability of agglomerates formed under pH and water hardness representative of Lake Geneva environmental conditions is investigated. In these conditions the large TiO2 agglomerates (diameter>1μm) are positively charged due to Ca(2+) and Mg(2+) specific adsorption and alginate, which is negatively charged, adsorbs onto the agglomerate surface. Our results indicate that the presence of alginate at typical natural organic matter concentration (1-10 mg L(-1)) strongly modifies the TiO2 agglomerate (50 mg L(-1)) stability by inducing their partial and rapid disagglomeration. The importance of disagglomeration is found dependent on the alginate concentration with maximum of disagglomeration obtained for alginate concentration ≥8 mg L(-1) and leading to 400 nm fragments. From an environmental point of view partial restabilization of TiO2 agglomerates in the presence of alginate constitutes an important outcome. Disagglomeration will enhance their transport and residence time in aquatic systems which is an important step in the current knowledge on risk assessment associated to engineered nanoparticles. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Characterization and optimization of the visualization performance of continuous flow overhauser DNP hyperpolarized water MRI: Inversion recovery approach.

    Science.gov (United States)

    Terekhov, Maxim; Krummenacker, Jan; Denysenkov, Vasyl; Gerz, Kathrin; Prisner, Thomas; Schreiber, Laura Maria

    2016-03-01

    Overhauser dynamic nuclear polarization (DNP) allows the production of liquid hyperpolarized substrate inside the MRI magnet bore as well as its administration in continuous flow mode to acquire MR images with enhanced signal-to-noise ratio. We implemented inversion recovery preparation in order to improve contrast-to-noise ratio and to quantify the overall imaging performance of Overhauser DNP-enhanced MRI. The negative enhancement created by DNP in combination with inversion recovery (IR) preparation allows canceling selectively the signal originated from Boltzmann magnetization and visualizing only hyperpolarized fluid. The theoretical model describing gain of MR image intensity produced by steady-state continuous flow DNP hyperpolarized magnetization was established and proved experimentally. A precise quantification of signal originated purely from DNP hyperpolarization was achieved. A temperature effect on longitudinal relaxation had to be taken into account to fit experimental results with numerical prediction. Using properly adjusted IR preparation, the complete zeroing of thermal background magnetization was achieved, providing an essential increase of contrast-to-noise ratio of DNP-hyperpolarized water images. To quantify and optimize the steady-state conditions for MRI with continuous flow DNP, an approach similar to that incorporating transient-state thermal magnetization equilibrium in spoiled fast field echo imaging sequences can be used. © 2015 Wiley Periodicals, Inc.

  14. Blood gas sample spiking with total parenteral nutrition, lipid emulsion, and concentrated dextrose solutions as a model for predicting sample contamination based on glucose result.

    Science.gov (United States)

    Jara-Aguirre, Jose C; Smeets, Steven W; Wockenfus, Amy M; Karon, Brad S

    2018-05-01

    Evaluate the effects of blood gas sample contamination with total parenteral nutrition (TPN)/lipid emulsion and dextrose 50% (D50) solutions on blood gas and electrolyte measurement; and determine whether glucose concentration can predict blood gas sample contamination with TPN/lipid emulsion or D50. Residual lithium heparin arterial blood gas samples were spiked with TPN/lipid emulsion (0 to 15%) and D50 solutions (0 to 2.5%). Blood gas (pH, pCO2, pO2), electrolytes (Na+, K+ ionized calcium) and hemoglobin were measured with a Radiometer ABL90. Glucose concentration was measured in separated plasma by Roche Cobas c501. Chart review of neonatal blood gas results with glucose >300 mg/dL (>16.65 mmol/L) over a seven month period was performed to determine whether repeat (within 4 h) blood gas results suggested pre-analytical errors in blood gas results. Results were used to determine whether a glucose threshold could predict contamination resulting in blood gas and electrolyte results with greater than laboratory-defined allowable error. Samples spiked with 5% or more TPN/lipid emulsion solution or 1% D50 showed glucose concentration >500 mg/dL (>27.75 mmol/L) and produced blood gas (pH, pO 2 , pCO 2 ) results with greater than laboratory-defined allowable error. TPN/lipid emulsion, but not D50, produced greater than allowable error in electrolyte (Na + ,K + ,Ca ++ ,Hb) results at these concentrations. Based on chart review of 144 neonatal blood gas results with glucose >250 mg/dL received over seven months, four of ten neonatal intensive care unit (NICU) patients with glucose results >500 mg/dL and repeat blood gas results within 4 h had results highly suggestive of pre-analytical error. Only 3 of 36 NICU patients with glucose results 300-500 mg/dL and repeat blood gas results within 4 h had clear pre-analytical errors in blood gas results. Glucose concentration can be used as an indicator of significant blood sample contamination with either TPN

  15. Adsorption of low concentration ceftazidime from aqueous solutions using impregnated activated carbon promoted by Iron, Copper and Aluminum

    Science.gov (United States)

    Hu, Xiang; Zhang, Hua; Sun, Zhirong

    2017-01-01

    In this paper, three impregnated activated carbon IAC (AC-Cu, AC-Fe, and AC-Al) promoted by Iron, Copper and Aluminum were used for adsorption of ceftazidime. Iron(III), Copper(II) and Aluminum(III) nitrate were used as an impregnant. The IACs were characterized by scanning electron microscope (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, Fourier transform infrared spectroscopy (FTIR) and X-ray Photoelectron Spectroscopy (XPS).The influence of factors, such as ion strength, pH, temperature, initial concentration, and concentration of natural organic matter organic matter on the adsorption process were studied. The adsorption kinetics and isotherms of ceftazidime were studied for the three IACs. The results showed that the adsorption was accurately represented by pseudo-second order model. Under different temperature, the maximum adsorption quantity of ceftazidime on AC-Cu calculated by pseudo-second order kinetic model were 200.0 mg g-1 (298 K), 196.1 mg g-1 (303 K) and 185.2 mg g-1 (308 K). It was much higher than that of AC-Fe and AC-Al. And the process was controlled by both film diffusion and intra particle mass transport. The results also showed that, the Freundlich and Temkin isotherm fit the adsorption well.

  16. Estimated glomerular filtration rate is a poor predictor of the concentration of middle molecular weight uremic solutes in chronic kidney disease.

    Directory of Open Access Journals (Sweden)

    Nathalie Neirynck

    Full Text Available BACKGROUND: Uremic solute concentration increases as Glomerular Filtration Rate (GFR declines. Weak associations were demonstrated between estimated GFR (eGFR and the concentrations of several small water-soluble and protein-bound uremic solutes (MW500 Da. MATERIALS AND METHODS: In 95 CKD-patients (CKD-stage 2-5 not on dialysis, associations between different eGFR-formulae (creatinine, Cystatin C-based or both and the natural logarithm of the concentration of several LMWP's were analyzed: i.e. parathyroid hormone (PTH, Cystatin C (CystC, interleukin-6 (IL-6, tumor necrosis factor-alpha (TNF-α, leptin, retinol binding protein (RbP, immunoglobin light chains kappa and lambda (Ig-κ and Ig-λ, beta-2-microglobulin (β(2M, myoglobin and fibroblast growth factor-23 (FGF-23. RESULTS: The regression coefficients (R(2 between eGFR, based on the CKD-EPI-Crea-CystC-formula as reference, and the examined LMWP's could be divided into three groups. Most of the LMWP's associated weakly (R(2 0.7. Almost identical R(2-values were found per LMWP for all eGFR-formulae, with exception of CystC and β(2M which showed weaker associations with creatinine-based than with CystC-based eGFR. CONCLUSION: The association between eGFR and the concentration of several LMWP's is inconsistent, with in general low R(2-values. Thus, the use of eGFR to evaluate kidney function does not reflect the concentration of several LMWP's with proven toxic impact in CKD.

  17. Fine root biomass, necromass and chemistry during seven years of elevated aluminium concentrations in the soil solution of a middle-aged Picea abies stand.

    Science.gov (United States)

    Eldhuset, Toril D; Lange, Holger; de Wit, Helene A

    2006-10-01

    Toxic effects of aluminium (Al) on Picea abies (L.) Karst. (Norway spruce) trees are well documented in laboratory-scale experiments, but field-based evidence is scarce. This paper presents results on fine root growth and chemistry from a field manipulation experiment in a P. abies stand that was 45 years old when the experiment started in 1996. Different amounts of dissolved aluminium were added as AlCl3 by means of periodic irrigation during the growing season in the period 1997-2002. Potentially toxic concentrations of Al in the soil solution were obtained. Fine roots were studied from direct cores (1996) and sequential root ingrowth cores (1999, 2001, 2002) in the mineral soil (0-40 cm). We tested two hypotheses: (1) elevated concentration of Al in the root zone leads to significant changes in root biomass, partitioning into fine, coarse, living or dead fractions, and distribution with depth; (2) elevated Al concentration leads to a noticeable uptake of Al and reduced uptake of Ca and Mg; this results in Ca and Mg depletion in roots. Hypothesis 1 was only marginally supported, as just a few significant treatment effects on biomass were found. Hypothesis 2 was supported in part; Al addition led to increased root concentrations of Al in 1999 and 2002 and reduced Mg/Al in 1999. Comparison of roots from subsequent root samplings showed a decrease in Al and S over time. The results illustrated that 7 years of elevated Al(tot) concentrations in the soil solution up to 200 microM are not likely to affect root growth. We also discuss possible improvements of the experimental approach.

  18. Molecular dynamics simulations of the electrical double layer on smectite surfaces contacting concentrated mixed electrolyte (NaCl-CaCl2) solutions.

    Science.gov (United States)

    Bourg, Ian C; Sposito, Garrison

    2011-08-15

    We report new molecular dynamics results elucidating the structure of the electrical double layer (EDL) on smectite surfaces contacting mixed NaCl-CaCl(2) electrolyte solutions in the range of concentrations relevant to pore waters in geologic repositories for CO(2) or high-level radioactive waste (0.34-1.83 mol(c) dm(-3)). Our results confirm the existence of three distinct ion adsorption planes (0-, β-, and d-planes), often assumed in EDL models, but with two important qualifications: (1) the location of the β- and d-planes are independent of ionic strength or ion type and (2) "indifferent electrolyte" ions can occupy all three planes. Charge inversion occurred in the diffuse ion swarm because of the affinity of the clay surface for CaCl(+) ion pairs. Therefore, at concentrations ≥0.34 mol(c) dm(-3), properties arising from long-range electrostatics at interfaces (electrophoresis, electro-osmosis, co-ion exclusion, colloidal aggregation) will not be correctly predicted by most EDL models. Co-ion exclusion, typically neglected by surface speciation models, balanced a large part of the clay mineral structural charge in the more concentrated solutions. Water molecules and ions diffused relatively rapidly even in the first statistical water monolayer, contradicting reports of rigid "ice-like" structures for water on clay mineral surfaces. Published by Elsevier Inc.

  19. Adsorption of proteins at the solution/air interface influenced by added nonionic surfactants at very low concentrations for both components. 3. Dilational surface rheology.

    Science.gov (United States)

    Fainerman, V B; Aksenenko, E V; Lylyk, S V; Lotfi, M; Miller, R

    2015-03-05

    The influence of the addition of the nonionic surfactants C12DMPO, C14DMPO, C10OH, and C10EO5 at concentrations between 10(-5) and 10(-1) mmol/L to solutions of β-casein (BCS) and β-lactoglobulin (BLG) at a fixed concentration of 10(-5) mmol/L on the dilational surface rheology is studied. A maximum in the viscoelasticity modulus |E| occurs at very low surfactant concentrations (10(-4) to 10(-3) mmol/L) for mixtures of BCS with C12DMPO and C14DMPO and for mixtures of BLG with C10EO5, while for mixture of BCS with C10EO5 the value of |E| only slightly increased. The |E| values calculated with a recently developed model, which assumes changes in the interfacial molar area of the protein molecules due to the interaction with the surfactants, are in satisfactory agreement with experimental data. A linear dependence exists between the ratio of the maximum modulus for the mixture to the modulus of the single protein solution and the coefficient reflecting the influence of the surfactants on the adsorption activity of the protein.

  20. Effects of solution concentration and capping agents on the properties of potassium titanyl phosphate noparticles synthesized using a co-precipitation method

    Science.gov (United States)

    Gharibshahian, E.; Jafar Tafershi, M.; Fazli, M.

    2018-05-01

    In this study, KTiOPO4 (KTP) nanoparticles were synthesized using a co-precipitation method. The effects of the solution concentration (M) and capping agents, such as PVA, oxalic acid, glycine, triethanolamine, and L-alanine, on the structural, microstructural, and optical properties of the products were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy. Decreasing the solution concentration decreased the crystallite size from 53.07 nm (for M = 2) to 39.42 nm (for M = 0.5). After applying different capping agents to the sample at the optimum concentration (M = 0.5), the crystallite size decreased again and grains as small as 10.61 nm were obtained. XRD and FTIR analyses indicated the formation of KTP nanoparticles with an orthorhombic structure in all of the samples. The optical band gap increased as the crystallite size decreased. Different morphological patterns such as spherical, needle shaped, polyhedron, and tablet forms were observed in the nanoparticles, which were correlated with the effects of the capping agents employed.

  1. Acetylene Black/Sulfur Composites Synthesized by a Solution Evaporation Concentration Crystallization Method and Their Electrochemical Properties for Li/S Batteries

    Directory of Open Access Journals (Sweden)

    Zhigao Yang

    2013-07-01

    Full Text Available A novel technique to prepare carbon/sulfur composites as cathode materials for Li/S batteries is proposed, which we call the ‘solution evaporation concentration crystallization’ method. Three composites with different S loadings were prepared, subject to two different solvent evaporation rates from acetylene black (AB/sulfur in carbon disulfide solutions. X-ray diffraction, environmental scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller measurements all show that the porous AB structure is well-filled with S. Composites prepared at a lower solvent evaporation rate with 50 wt % S content, had good electrochemical properties, with 1609.67 mAh g−1 after 100 cycles. Composites with better dispersibility at a low solvent evaporation rate can effectively prevent polysulfide from dissolving in the electrolyte, and serve to stabilize the structure of the S cathode during the charge-discharge process.

  2. Preparation of Organic/Inorganic Siloxane Composite Membranes and Concentration of n-butanol from ABE Solution by Pervaporation

    Energy Technology Data Exchange (ETDEWEB)

    Jee, Ki Yong; Lee, Yong Taek [Kyung Hee University, Yongin (Korea, Republic of)

    2013-10-15

    In this paper, polymer composite membranes and ceramic composite membranes were prepared in order to compare differences in pervaporation performances relative to the support layers. PVDF was used for the polymer support layers, and a-Al{sub 2}O{sub 3} was used for the ceramic support layers. For active layer was coated for PDMS, which is a rubbery polymer. The characterization of membranes were analysed by SEM, contact angle, and XPS. We studied performances relative to the composite membrane support layers in the ABE mixture solutions. The results of the pervaporation, the flux of the ceramic composite membrane was shown to be 250.87 g/m{sup 2}h, which was higher than that of polymer composite membranes, at 195.64 g/m{sup 2}h. However, it was determined that the separation factor of the polymer composite membranes was 31.98 which were higher than that of the ceramic composite membranes, at 20.66.

  3. The thermodynamic characteristics of the reaction between vanadium(5) and hydrogen peroxide in concentrated solutions of perchloric acid

    International Nuclear Information System (INIS)

    Vorob'ev, P.N.; Dmitrieva, N.G.; Poteshonkova, T.A.

    2001-01-01

    Stability constants of vanadium(5) complex with hydrogen peroxide and enthalpy of vanadium(5) complexing with hydrogen peroxide are determined at acidity of solution c(H + ) = 5.00 mol/l, temperature T = 298.15 K and values of ionic force: I = 5, 6 and 7. Standard thermodynamic characteristics of vanadium(5) peroxide complex formation were calculated. At zeroth ionic force the value of complexing enthalpy Δ r H 298.15 deg is equal to -48.59 ± 0.33 kJ/mol, standard enthalpy of peroxide vanadium(5) complex formation Δ f H 298.15 deg is equal to -895.49 ± 1.51 kJ/mol; Δ r G 298.15 deg = -36.51 kJ/mol, Δ r S 298.15 deg -40.51 J/(mol K). As it is shown by calculations, standard change in entropy of the reaction has a minus sign, that is unique to complexation with neutral ligand [ru

  4. Protein aggregation in aqueous casein solution. Effect of irradiation, dose level, concentration, storage and additives (carbohydrate and lipid)

    Energy Technology Data Exchange (ETDEWEB)

    Yousri, R M

    1980-06-01

    From the vast amount of research efforts dealing with various aspects of radiation effects on foods and food components, it is apparent up to now that much remains to be studied in depth, much may have to be added or corrected about radiation-induced physico-chemical changes in foods. A great many reactions that take place when foodstuffs are subjected to ionizing radiation are still not fully understood. The better understanding of some of the radiation-induced changes in pure proteins as such or in mixture with other food constituents could yield much data which could be meaningfully extrapolated to intact foods and consequently could help to improve the assessment of the wholesomeness of irradiated foods. It was the purpose of our investigations to elucidate some of the changes in the chemical structure of a pure protein (casein), irradiated as such or with added carbohydrate and/or lipid. The effect of subsequent storage of the irradiated solutions has been also examined. The formation of protein aggregates was studied by gel filtration technique. The application of thin-layer gel filtration, its speed and adaptability to very small samples facilitated the measurements of the extent of aggregation which occurred in protein molecules after irradiation.

  5. Lever conditioned stimulus-directed autoshaping induced by saccharin-ethanol unconditioned stimulus solution: effects of ethanol concentration and trial spacing.

    Science.gov (United States)

    Tomie, Arthur; Festa, Eugene D; Sparta, Dennis R; Pohorecky, Larissa A

    2003-05-01

    Two experiments were designed to evaluate whether brief access to a saccharin-ethanol solution would function as an effective unconditioned stimulus (US) in Pavlovian-autoshaping procedures. In these experiments, the insertion of a lever conditioned stimulus (CS) was followed by the brief presentation of a sipper tube containing saccharin-ethanol US solution. Experience with this Pavlovian-autoshaping procedure engendered lever CS-directed autoshaping conditioned responses (CRs) in all rats. In Experiment 1, the concentration of ethanol [0%, 2%, 4%, 6%, or 8% (vol./vol.)] in 0.1% saccharin was systematically increased within subjects across autoshaping sessions to evaluate the relation between a rat's drinking and lever pressing. In Experiment 2, the mean intertrial interval (ITI) duration (60, 90, 120 s) was systematically increased within subjects across autoshaping sessions to evaluate the effect of ITI duration on drinking and lever pressing. A pseudoconditioning control group received lever CS randomly with respect to the saccharin-ethanol US solution. In Experiment 1, lever-press autoshaping CRs developed in all rats, and the tendency of a rat to drink an ethanol concentration was predictive of the performance of lever-press autoshaping CRs. In Experiment 2, longer ITIs induced more lever CS-directed responding, and CS-US paired procedures yielded more lever CS-directed responding than that observed in CS-US random procedures. Saccharin-ethanol is an effective US in Pavlovian-autoshaping procedures, inducing more CS-directed responding than in pseudoconditioning controls receiving CS-US random procedures. More lever CS-directed responding was observed when there was more drinking of the saccharin-ethanol US solution (Experiment 1); when the CS and US were paired, rather than random (Experiment 2); and with longer mean ITI durations (Experiment 2). This pattern of results is consistent with the hypothesis that lever CS-directed responding reflects performance

  6. Data on the solute concentration within the subsurface flows of Little Lost Man Creek in response to a transport experiment, Redwood National Park, northwest California

    Science.gov (United States)

    Zellweger, Gary W.; Kennedy, V.C.; Bencala, K.E.; Avanzino, R.J.; Jackman, A.P.; Triska, F.J.

    1986-01-01

    A solute transport experiment was conducted on a 327-m reach of Little Lost Man Creek, a small stream in Humboldt County, California. Solutes were injected for 20 days. Chloride was used as a conservative tracer; lithium, potassium, and strontium were used as reactive tracers. In addition, nitrate and phosphate were added as biological reactants. Eighteen shallow wells were dug along the length of the study reach, 1-10 m laterally from the edge of the stream. The wells and sites in the stream were monitored for the injected solutes during and after the injection. Solute concentrations in the wells and stream are indicative of transport properties of stream and subsurface channel flow. This report presents the results of the analyses of the well samples and chemical data relevant to the interpretation of hydrological and chemical interaction between the stream and adjacent channel subsurface flows in the streambed. Calculations of the percentage of streamwater in the wellwater were made from conservative tracer measurements. The composition of wellwater ranged from 47% to 100% streamwater with most values above 90%. The time for water to travel from the beginning of the study reach to the wells was approximately three times as great as the travel time in the stream at the same distance down the reach. The three conclusions that can be drawn are (1) water in the stream exchanges extensively with water in the rest of the channel; (2) the interstitial water in the channel gravels achieves almost the same composition as the stream; and (3) under low flow conditions the stream gravels contain a significant portion of the stream volume. Plots of normalized chloride, lithium, and strontium concentrations at three stream sites are included. (Author 's abstract)

  7. Hyperpolarization-activated current (In is reduced in hippocampal neurons from Gabra5-/- mice.

    Directory of Open Access Journals (Sweden)

    Robert P Bonin

    Full Text Available Changes in the expression of γ-aminobutyric acid type A (GABAA receptors can either drive or mediate homeostatic alterations in neuronal excitability. A homeostatic relationship between α5 subunit-containing GABAA (α5GABAA receptors that generate a tonic inhibitory conductance, and HCN channels that generate a hyperpolarization-activated cation current (Ih was recently described for cortical neurons, where a reduction in Ih was accompanied by a reciprocal increase in the expression of α5GABAA receptors resulting in the preservation of dendritosomatic synaptic function. Here, we report that in mice that lack the α5 subunit gene (Gabra5-/-, cultured embryonic hippocampal pyramidal neurons and ex vivo CA1 hippocampal neurons unexpectedly exhibited a decrease in Ih current density (by 40% and 28%, respectively, compared with neurons from wild-type (WT mice. The resting membrane potential and membrane hyperpolarization induced by blockade of Ih with ZD-7288 were similar in cultured WT and Gabra5-/- neurons. In contrast, membrane hyperpolarization measured after a train of action potentials was lower in Gabra5-/- neurons than in WT neurons. Also, membrane impedance measured in response to low frequency stimulation was greater in cultured Gabra5-/- neurons. Finally, the expression of HCN1 protein that generates Ih was reduced by 41% in the hippocampus of Gabra5-/- mice. These data indicate that loss of a tonic GABAergic inhibitory conductance was followed by a compensatory reduction in Ih. The results further suggest that the maintenance of resting membrane potential is preferentially maintained in mature and immature hippocampal neurons through the homeostatic co-regulation of structurally and biophysically distinct cation and anion channels.

  8. Hyperpolarized Amino Acid Derivatives as Multivalent Magnetic Resonance pH Sensor Molecules

    Directory of Open Access Journals (Sweden)

    Christian Hundshammer

    2018-02-01

    Full Text Available pH is a tightly regulated physiological parameter that is often altered in diseased states like cancer. The development of biosensors that can be used to non-invasively image pH with hyperpolarized (HP magnetic resonance spectroscopic imaging has therefore recently gained tremendous interest. However, most of the known HP-sensors have only individually and not comprehensively been analyzed for their biocompatibility, their pH sensitivity under physiological conditions, and the effects of chemical derivatization on their logarithmic acid dissociation constant (pKa. Proteinogenic amino acids are biocompatible, can be hyperpolarized and have at least two pH sensitive moieties. However, they do not exhibit a pH sensitivity in the physiologically relevant pH range. Here, we developed a systematic approach to tailor the pKa of molecules using modifications of carbon chain length and derivatization rendering these molecules interesting for pH biosensing. Notably, we identified several derivatives such as [1-13C]serine amide and [1-13C]-2,3-diaminopropionic acid as novel pH sensors. They bear several spin-1/2 nuclei (13C, 15N, 31P with high sensitivity up to 4.8 ppm/pH and we show that 13C spins can be hyperpolarized with dissolution dynamic polarization (DNP. Our findings elucidate the molecular mechanisms of chemical shift pH sensors that might help to design tailored probes for specific pH in vivo imaging applications.

  9. A comparison of quantitative methods for clinical imaging with hyperpolarized (13)C-pyruvate.

    Science.gov (United States)

    Daniels, Charlie J; McLean, Mary A; Schulte, Rolf F; Robb, Fraser J; Gill, Andrew B; McGlashan, Nicholas; Graves, Martin J; Schwaiger, Markus; Lomas, David J; Brindle, Kevin M; Gallagher, Ferdia A

    2016-04-01

    Dissolution dynamic nuclear polarization (DNP) enables the metabolism of hyperpolarized (13)C-labelled molecules, such as the conversion of [1-(13)C]pyruvate to [1-(13)C]lactate, to be dynamically and non-invasively imaged in tissue. Imaging of this exchange reaction in animal models has been shown to detect early treatment response and correlate with tumour grade. The first human DNP study has recently been completed, and, for widespread clinical translation, simple and reliable methods are necessary to accurately probe the reaction in patients. However, there is currently no consensus on the most appropriate method to quantify this exchange reaction. In this study, an in vitro system was used to compare several kinetic models, as well as simple model-free methods. Experiments were performed using a clinical hyperpolarizer, a human 3 T MR system, and spectroscopic imaging sequences. The quantitative methods were compared in vivo by using subcutaneous breast tumours in rats to examine the effect of pyruvate inflow. The two-way kinetic model was the most accurate method for characterizing the exchange reaction in vitro, and the incorporation of a Heaviside step inflow profile was best able to describe the in vivo data. The lactate time-to-peak and the lactate-to-pyruvate area under the curve ratio were simple model-free approaches that accurately represented the full reaction, with the time-to-peak method performing indistinguishably from the best kinetic model. Finally, extracting data from a single pixel was a robust and reliable surrogate of the whole region of interest. This work has identified appropriate quantitative methods for future work in the analysis of human hyperpolarized (13)C data. © 2016 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.

  10. Ovariectomy increases the participation of hyperpolarizing mechanisms in the relaxation of rat aorta.

    Directory of Open Access Journals (Sweden)

    Ana Sagredo

    Full Text Available This study examines the downstream NO release pathway and the contribution of different vasodilator mediators in the acetylcholine-induced response in rat aorta 5-months after the loss of ovarian function. Aortic segments from ovariectomized and control female Sprague-Dawley rats were used to measure: the levels of superoxide anion, the superoxide dismutases (SODs activity, the cGMP formation, the cGMP-dependent protein kinase (PKG activity and the involvement of NO, cGMP, hydrogen peroxide and hyperpolarizing mechanisms in the ACh-induced relaxation. The results showed that ovariectomy did not alter ACh-induced relaxation; incubation with L-NAME, a NO synthase inhibitor, decreased the ACh-induced response to a lesser extent in aorta from ovariectomized than from control rats, while ODQ, a guanylate cyclase inhibitor, decreased that response to a similar extent; the blockade of hyperpolarizing mechanisms, by precontracting arteries with KCl, decreased the ACh-induced response to a greater extent in aortas from ovariectomized than those from control rats; catalase, that decomposes hydrogen peroxide, decreased the ACh-induced response only in aorta from ovariectomized rats. In addition, ovariectomy increased superoxide anion levels and SODs activity, decreased cGMP formation and increased PKG activity. Despite the increased superoxide anion and decreased cGMP in aorta from ovariectomized rats, ACh-induced relaxation is maintained by the existence of hyperpolarizing mechanisms in which hydrogen peroxide participates. The greater contribution of hydrogen peroxide in ACh-induced relaxation is due to increased SOD activity, in an attempt to compensate for increased superoxide anion formation. Increased PKG activity could represent a redundant mechanism to ensure vasodilator function in the aorta of ovariectomized rats.

  11. Assessing the transport rate of hyperpolarized pyruvate and lactate from the intra- to the extracellular space.

    Science.gov (United States)

    Reineri, Francesca; Daniele, Valeria; Cavallari, Eleonora; Aime, Silvio

    2016-08-01

    The use of [1-(13) C]pyruvate hyperpolarized by means of dynamic nuclear polarization provides a direct way to track the metabolic transformations of this metabolite in vivo and in cell cultures. The identification of the intra- and extracellular contributions to the (13) C NMR resonances is not straightforward. In order to obtain information about the rate of pyruvate and lactate transport through the cellular membrane, we set up a method that relies on the sudden 'quenching' of the extracellular metabolites' signal. The paramagnetic Gd-tetraazacyclododecane triacetic acid (Gd-DO3A) complex was used to dramatically decrease the longitudinal relaxation time constants of the (13) C-carboxylate resonances of both pyruvate and lactate. When Gd-DO3A was added to an MCF-7 cellular culture, which had previously received a dose of hyperpolarized [1-(13) C]pyruvate, the contributions of the extracellular pyruvate and lactate signals were deleted. From the analysis of the decay curves of the (13) C-carboxylate resonances of pyruvate and lactate it was possible to extract information about the exchange rate of the two metabolites across the cellular membrane. In particular, it was found that, in the reported experimental conditions, the lactate transport from the intra- to the extracellular space is not much lower than the rate of lactate formation. The method reported herein is non-destructive and it could be translated to in vivo studies. It opens a route for the use of hyperpolarized pyruvate to assess altered activity of carboxylate transporter proteins that may occur in pathological conditions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Effect of precursor solutions stirring on deep level defects concentration and spatial distribution in low temperature aqueous chemical synthesis of zinc oxide nanorods

    Directory of Open Access Journals (Sweden)

    Hatim Alnoor

    2015-08-01

    Full Text Available Hexagonal c-axis oriented zinc oxide (ZnO nanorods (NRs with 120-300 nm diameters are synthesized via the low temperature aqueous chemical route at 80 °C on silver-coated glass substrates. The influence of varying the precursor solutions stirring durations on the concentration and spatial distributions of deep level defects in ZnO NRs is investigated. Room temperature micro-photoluminesnce (μ-PL spectra were collected for all samples. Cathodoluminescence (CL spectra of the as-synthesized NRs reveal a significant change in the intensity ratio of the near band edge emission (NBE to the deep-level emission (DLE peaks with increasing stirring durations. This is attributed to the variation in the concentration of the oxygen-deficiency with increasing stirring durations as suggested from the X-ray photoelectron spectroscopy analysis. Spatially resolved CL spectra taken along individual NRs revealed that stirring the precursor solutions for relatively short duration (1-3 h, which likely induced high super saturation under thermodynamic equilibrium during the synthesis process, is observed to favor the formation of point defects moving towards the tip of the NRs. In contrary, stirring for longer duration (5-15 h will induce low super saturation favoring the formation of point defects located at the bottom of the NRs. These findings demonstrate that it is possible to control the concentration and spatial distribution of deep level defects in ZnO NRs by varying the stirring durations of the precursor solutions.

  13. Selective oxidation of glycerol to formic acid in highly concentrated aqueous solutions with molecular oxygen using V-substituted phosphomolybdic acids

    KAUST Repository

    Zhang, Jizhe

    2014-01-01

    Formic acid is an important commodity chemical as well as a promising medium for hydrogen storage and hydrogen production. In this paper, we report that formic acid can be produced through selective oxidation of glycerol, a low-cost by-product of biodiesel, by using vanadium-substituted phosphomolybdic acids as catalysts and molecular oxygen as the oxidant. Significantly, this catalytic system allows for high-concentration conversions and thus leads to exceptional efficiency. Specifically, 3.64 g of formic acid was produced from 10 g of glycerol/water (50/50 in weight) solution. © 2014 the Partner Organisations.

  14. Hyperpolarized 13C Urea Relaxation Mechanism Reveals Renal Changes in Diabetic Nephropathy

    DEFF Research Database (Denmark)

    Laustsen, Christoffer; Stokholm Nørlinger, Thomas; Christoffer Hansen, David

    2016-01-01

    Purpose: Our aim was to assess a novel 13C radial fast spin echo golden ratio single shot method for interrogating early renal changes in the diabetic kidney, using hyperpolarized (HP) [13C,15N2]urea as a T2 relaxation based contrast bio-probe. Methods: A novel HP 13C MR contrast experiment...... saturation level and the relaxation times were observed in the healthy controls. Conclusion: HP [13C,15N2]urea apparent T2 mapping may be a useful for interrogating local renal pO2 status and renal tissue alterations....

  15. Monitoring Cancer Response to Treatment with Hyperpolarized 13C MRS

    DEFF Research Database (Denmark)

    Eldirdiri, Abubakr

    , and the patient is exposed to ionizing radiation. The introduction of hyperpolarized 13C MRS has opened completely new possibilities to study the biochemical changes in disease processes. Numerous 13C-labeled compounds were proposed to interrogate various aspects of cancer cell metabolism. The aim of this study......Monitoring the cancer response to treatment, non-invasively, by medical imaging is a key element in the management of cancer. For patients undergoing treatment, it is crucial to determine responders from non-responders in order to guide treatment decisions. Currently, PET is the most widely used...

  16. Determination of iodine concentration in aqueous solutions by proton activation analysis: preliminary results for digested human thyroids

    International Nuclear Information System (INIS)

    Wojcik, A.K.; AGH University of Science and Technology, Krakow; Pawel Zagrodzki; Collegium Medicum Jagiellonian University, Krakow; Mietelski, J.W.; Bogdan Was

    2012-01-01

    The aim of our studies is to check the possibilities of using proton activation analysis as a competitive method over other analytical techniques applied for iodine determination. It is well known that long-term irradiation of biological samples leads to their decomposition and formation of gaseous radiolysis products, which increase the pressure inside the sample container. In case of using proton beam another problem with liquid samples appears. It is the production of 7 Be via spallation reactions 16 O(p, spall) 7 Be. The Compton effect from 7 Be γ-line increases the detection limits for isotopes with low-energy γ-lines. AIC-144 cyclotron at The Niewodniczanski Institute of Nuclear Physics Polish Academy of Science can accelerate protons up to energy of 60 MeV which is sufficient for (p,5n) reaction needed to obtain 123 I (T 1/2 = 13.27 h, Eγ = 159 keV, I 83%) from stable 127 I, thus the Compton effect from 7 Be was the main factor perturbing the analysis. Separation and removal of 7 Be is required to improve the detection limit. The paper presents a method and an example of its application to the determination of iodine concentration in digested fragments of human thyroids obtained during surgical treatment of patients with different types of thyroid tumor. (author)

  17. Hyperpolarized 13C MR imaging detects no lactate production in mutant IDH1 gliomas: Implications for diagnosis and response monitoring

    Directory of Open Access Journals (Sweden)

    Myriam M. Chaumeil

    2016-01-01

    Full Text Available Metabolic imaging of brain tumors using 13C Magnetic Resonance Spectroscopy (MRS of hyperpolarized [1-13C] pyruvate is a promising neuroimaging strategy which, after a decade of preclinical success in glioblastoma (GBM models, is now entering clinical trials in multiple centers. Typically, the presence of GBM has been associated with elevated hyperpolarized [1-13C] lactate produced from [1-13C] pyruvate, and response to therapy has been associated with a drop in hyperpolarized [1-13C] lactate. However, to date, lower grade gliomas had not been investigated using this approach. The most prevalent mutation in lower grade gliomas is the isocitrate dehydrogenase 1 (IDH1 mutation, which, in addition to initiating tumor development, also induces metabolic reprogramming. In particular, mutant IDH1 gliomas are associated with low levels of lactate dehydrogenase A (LDHA and monocarboxylate transporters 1 and 4 (MCT1, MCT4, three proteins involved in pyruvate metabolism to lactate. We therefore investigated the potential of 13C MRS of hyperpolarized [1-13C] pyruvate for detection of mutant IDH1 gliomas and for monitoring of their therapeutic response. We studied patient-derived mutant IDH1 glioma cells that underexpress LDHA, MCT1 and MCT4, and wild-type IDH1 GBM cells that express high levels of these proteins. Mutant IDH1 cells and tumors produced significantly less hyperpolarized [1-13C] lactate compared to GBM, consistent with their metabolic reprogramming. Furthermore, hyperpolarized [1-13C] lactate production was not affected by chemotherapeutic treatment with temozolomide (TMZ in mutant IDH1 tumors, in contrast to previous reports in GBM. Our results demonstrate the unusual metabolic imaging profile of mutant IDH1 gliomas, which, when combined with other clinically available imaging methods, could be used to detect the presence of the IDH1 mutation in vivo.

  18. Effects of structural and textural grain characteristics on leaching of sulphide minerals from a polymetallic concentrate by sodium nitrate and sulphuric acid solution

    Directory of Open Access Journals (Sweden)

    Sokić Miroslav D.

    2017-01-01

    Full Text Available In this paper, the influence of structural and textural characteristics of sulfide minerals on their leaching from a polymetallic concentrate by sulfuric acid and sodium nitrate solution is presented. The starting material was Pb–Zn–Cu sulphide polymetallic concentrate enriched during the flotation of a polymetallic ore in the "Rudnik" flotation plant (Rudnik – Serbia. Leaching experiments were carried out in a closed glass reactor, which provides stable hermetic conditions and allows heating at constant temperature. Chemical, XRD, qualitative and quantitative microscopic and SEM/EDX analyses were used to characterizes samples of the polymetallic concentrate and leach residue. It was determined that chalcopyrite, sphalerite, galena, pyrrhotite and quartz were present in the polymetallic concentrate. The content of sulphide minerals was 69.5%, of which 60.9% occurred as liberated grains: 88.3% of chalcopyrite, 59.3% of sphalerite, 25.1% of galena and 51.6% of pirrhotite. The rest of chalcopyrite, sphalerite, galena and pirrhotite grains were in the forms of inclusions, impregnations, and simple and complex intergrowths. During the leaching process by sodium nitrate and sulphuric acid solution, it was shown previously that the leaching rate of sulphide minerals decreased with time while a part of the sulphide minerals remained in the leach residue. After leaching at 80°C for 120 min, the yields were 69.8, 82.7 and 67.1% for Cu, Zn and Fe, respectively. Lead, in the form of insoluble anglesite, remained in the leach residue. In addition to the anglesite, unleached sulfide minerals and quartz, elemental sulfur was found in the solid residue. The content of sulphide minerals was 35% of which 33.7% minerals occur independently. In specific, 54.7% of chalcopyrite, 31.9% of sphalerite, 8.2% of galena and 37.6% of pyrrhotite appear as separate grains with highly corroded surfaces. Therefore, the structural assembly of sulphide grains in the

  19. Imaging regional metabolic changes in the ischemic rat heart in vivo using hyperpolarized(1-13C)Pyruvate

    DEFF Research Database (Denmark)

    Lauritzen, Mette Hauge; Magnusson, Peter; Laustsen, Christoffer

    2017-01-01

    in the in vivo rat heart in an open-chest model of ischemia reperfusion. Hyperpolarized MRI enables new possibilities for evaluating changes in cardiac metabolism noninvasively and in real time, which potentially could be used for research to evaluate new treatments and metabolic interventions for myocardial......We evaluated the use of hyperpolarized 13C magnetic resonance imaging (MRI) in an open-chest rat model of myocardial infarction to image regional changes in myocardial metabolism. In total, 10 rats were examined before and after 30 minutes of occlusion of the left anterior descending coronary...

  20. Transmit-Only/Receive-Only Radiofrequency System for Hyperpolarized 13C MRS Cardiac Metabolism Studies in Pigs

    DEFF Research Database (Denmark)

    Giovannetti, G.; Frijia, F.; Hartwig, V.

    2013-01-01

    Hyperpolarized 13C magnetic resonance spectroscopy in pig models enables metabolic activity mapping, providing a powerful tool for the study of the heart physiology, but requires the development of dedicated radiofrequency coils, capable of providing large field of view with high signal......-to-noise ratio (SNR) data. This work describes the simulations and the tests of a transmit-only (TX) volume coil/receive-only (RX) surface coil both designed for hyperpolarized studies of pig heart with a clinical 3T scanner. The coil characterization is performed by developing an SNR model for coil performance...