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Sample records for fluid membrane-based soluble

  1. A Fluid Membrane-Based Soluble Ligand Display System for Live CellAssays

    SciTech Connect

    Nam, Jwa-Min; Nair, Pradeep N.; Neve, Richard M.; Gray, Joe W.; Groves, Jay T.

    2005-10-14

    Cell communication modulates numerous biological processes including proliferation, apoptosis, motility, invasion and differentiation. Correspondingly, there has been significant interest in the development of surface display strategies for the presentation of signaling molecules to living cells. This effort has primarily focused on naturally surface-bound ligands, such as extracellular matrix components and cell membranes. Soluble ligands (e.g. growth factors and cytokines) play an important role in intercellular communications, and their display in a surface-bound format would be of great utility in the design of array-based live cell assays. Recently, several cell microarray systems that display cDNA, RNAi, or small molecules in a surface array format were proven to be useful in accelerating high-throughput functional genetic studies and screening therapeutic agents. These surface display methods provide a flexible platform for the systematic, combinatorial investigation of genes and small molecules affecting cellular processes and phenotypes of interest. In an analogous sense, it would be an important advance if one could display soluble signaling ligands in a surface assay format that allows for systematic, patterned presentation of soluble ligands to live cells. Such a technique would make it possible to examine cellular phenotypes of interest in a parallel format with soluble signaling ligands as one of the display parameters. Herein we report a ligand-modified fluid supported lipid bilayer (SLB) assay system that can be used to functionally display soluble ligands to cells in situ (Figure 1A). By displaying soluble ligands on a SLB surface, both solution behavior (the ability to become locally enriched by reaction-diffusion processes) and solid behavior (the ability to control the spatial location of the ligands in an open system) could be combined. The method reported herein benefits from the naturally fluid state of the supported membrane, which allows

  2. Lamellar biogels: Fluid-membrane-based hydrogels containing polymer lipids

    SciTech Connect

    Warriner, H.E.; Idziak, S.H.J.; Slack, N.L.

    1996-02-16

    A class of lamellar biological hydrogels comprised of fluid membranes of lipids and surfactants with small amounts of low molecular weight poly(ethylene glycol)-derived polymer pipids (PEG-lipids) were studied by x-ray diffraction, polarized light microscopy, and rheometry. In contrast to isotropic hydrogels of polymer networks, these membrane-based birefringent liquid crystalline biogels, labeled L{sub {alpha},g,} form the gel phase when water is added to the liquid-like lamellar L{sub {alpha}} phase, which reenters a liquid-like mixed phase upon further dilution. Furthermore, gels with larger water content require less PEG-lipid to remain stable. Although concentrated ({approx}50 weight percent) mixtures of free PEG (molecular weight, 5000) and water do not gel, gelatin does occur in mixtures containing as little as 0.5 weight percent PEG lipid. A defining signature of the L{sub {alpha}, g} regime as it sets in from the fluid lamellar L{sub {alpha}} phase is the proliferation of layer-dislocation-type defects, which are stabilized by the segregation of PEG-lipids to the defect regions of high membrane curvature that connect the membranes. 32 refs., 5 figs.

  3. Controls on Calcite Solubility in Metamorphic and Magmatic Fluids

    NASA Astrophysics Data System (ADS)

    Manning, C. E.; Eguchi, J.; Galvez, M.

    2015-12-01

    Calcite is an important hydrothermal alteration product in a wide range of environments. The role of calcite in hydrothermal alteration depends on its solubility in geologic fluids, especially H2O. At ambient T and P, calcite solubility is low and it exhibits well-known declining, or "reverse", solubility with rising T. However, experimental and theoretical studies show that increasing P yields higher solubility and restricts the region of reverse solubility behavior to higher temperature. At 0.2 GPa the reverse solubility region lies at T>600°C; at 0.5 GPa, >800°C. Thus, whereas calcite possesses relatively low solubility in pure H2O in shallow hydrothermal systems (typically <10 ppm C), it is substantially more soluble at conditions of middle and lower crustal metamorphism and magmatism, reaching concentrations ≥1000 ppm. At the higher P of subduction zones, aragonite solubility in H2O is even greater. Thus, neglecting other solubility controls, calcite precipitation is favored as crustal fluids cool and/or decompress. However, the solubility of calcite in H2O also depends strongly on other solutes, pH, and fO2. Sources of alkalinity decrease calcite solubility. In contrast, sources of acidity such as CO2 and Cl increase solubility. Crustal fluids can be enriched in alkali halides such as NaCl. Calcite solubility increases with increasing salt content at a given P and T. From approximately seawater salinity to salt saturation, the fluid behaves as a dilute molten salt and calcite solubility increases as the square of the salt mole fraction regardless of the alkali (Li, Na, K, Cs) or halogen (F, Cl, Br, I) considered. Similar behavior is seen in mixed salt solutions. At lower salinities, solubility behavior is as expected in dilute electrolyte solutions. The transition from dilute electrolyte to molten salt is fundamental to the properties of crustal fluids. Reduction of carbonate species or CO2 in the fluid to CH4, which is common during serpentinization of

  4. Dietary fiber content influences soluble carbohydrate levels in ruminal fluids.

    PubMed

    Pinder, R S; Patterson, J A; O'Bryan, C A; Crandall, P G; Ricke, S C

    2012-01-01

    The soluble carbohydrate concentration of ruminal fluid, as affected by dietary forage content (DFC) and/or ruminally undegradable intake protein content (UIPC), was determined. Four ruminally cannulated steers, in a 4 × 4 Latin square design, were offered diets containing high (75 % of DM) or low (25 % of DM) DFC and high (6 % of DM) or low (5 % of DM) UIPC, in a 2 × 2 factorial arrangement. Zinc-treated SBM was the primary UIP source. Soluble hexose concentration (145.1 μM) in ruminal fluid (RF) of steers fed low DFC diets exhibited a higher trend (P = 0.08) than that (124.5 μM) of steers fed high DFC diets. UIPC did not modulate (P = 0.54) ruminal soluble hexose concentrations. Regardless of diet, soluble hexose concentration declined immediately after feeding and did not rise until 3 h after feeding (P < 0.0001). Cellobiose (≈90 %) and glucose (≈10 %) were the major soluble hexoses present in RF. Maltose was not detected. Soluble glucose concentration (13.0 μM) was not modified by either UIPC (P = 0.40) nor DFC (P = 0.61). However, a DFC by post-prandial time interaction was detected (P = 0.02). Pentose concentrations were greater (P = 0.02) in RF of steers fed high DFC (100.2 μM) than steers fed low DFC (177.0 μM). UIPC did not influence (P = 0.35) soluble pentose concentration. The identity of soluble pentoses in ruminal fluid could not be determined. However, unsubstituted xylose and arabinose were excluded. These data indicate that: (i) soluble carbohydrate concentrations remain in ruminal fluid during digestion and fermentation; (ii) slight diurnal changes began after feeding; (iii) DFC influences the soluble carbohydrate concentration in RF; and (iv) UIPC of these diets does not affect the soluble carbohydrate concentration of RF.

  5. Potentiometric analysis of water soluble cutting fluid-metal combinations

    SciTech Connect

    Kelley, E.E.

    1991-12-01

    The results of corrosion studies conducted by the University of Kansas under Contract G257763 for Allied-Signal Inc., Kansas City Division (KCD), are given. These potentiometric studies evaluate the corrosivity of two water soluble cutting fluids at varying concentrations on samples of 304 stainless steel, 6061-T6 aluminum, and beryllium copper. This testing serves two purposes: (1) to develop effective test procedures adaptable to existing KCD corrosion measurement equipment for corrosion analysis of cutting fluid-metals combinations, and (2) to understand the relative corrosiveness of the varying water soluble cutting fluids on different metals. The tests used were adapted from the American Society of Testing Materials (ASTM). Future testing will identify polarization techniques for establishing corrosion rates which will be used in evaluating both water soluble cutting fluids and other aqueous solutions used at KCD.

  6. Development of supercritical fluid extraction and supercritical fluid chromatography purification methods using rapid solubility screening with multiple solubility chambers.

    PubMed

    Gahm, Kyung H; Huang, Ke; Barnhart, Wesley W; Goetzinger, Wolfgang

    2011-01-01

    Rapid solubility screening in diverse supercritical fluids (SCFs) was carried out via multiple solubility chambers with a trapping device and online ultraviolet (UV) detection. With this device, it was possible to rapidly study the solubility variations of multiple components in a mixture. Results from solubility studies have been used to develop efficient supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC) methods. After the investigation of solubilities of theophylline and caffeine in several neat organic solvents and SCFs, advantages of SFE over conventional organic solvent extraction were demonstrated with a model mixture of theophylline and caffeine. The highest solubility ratio of 1:40 (theophylline:caffeine) was observed in the SCF with 20% acetonitrile (MeCN), where a ratio of 1:11 was the highest in the neat organic solvents. A model mixture of theophylline:caffeine (85:15 w/w, caffeine as an impurity) was successfully purified by SFE by leveraging the highest solubility difference. The SCF with 20% MeCN selectively removed caffeine and left theophylline largely intact. Rapid SCF solubility screening was applied to development of SFE and SFC methods in a drug discovery environment. Two successful applications were demonstrated with proprietary Amgen compounds to either remove an achiral impurity before chiral purification or enhance chiral chromatographic throughput.

  7. Solubilities in supercritical fluids: the application of chromatographic measurement methods

    SciTech Connect

    Smith, R.D.; Udseth, H.R.; Wright, B.W.; Yonker, C.R.

    1987-01-01

    New methods are described for the measurement of the solubilities of solids in supercritical fluids. These methods utilize instrumentation developed for capillary supercritical fluid chromatography consisting of deactivated, small diameter, fused silica tubing, coupled with detection methods based upon on flame ionization and mass spectrometric detectors. The methods involve (a) direct solubility determination where the fused silica capillary is used as an equilibrium cell, and (b) a pressure of threshold solubility technique which resembles chromatography and uses a programmed pressure increase and sensitive detection to determine the onset of solute migration. Results are also presented which suggest that solubilities can be determined, within certain limitations, from actual chromatographic experiments. The methods are illustrated using aromatic hydrocarbons and complex mycotoxins of the trichothecene group.

  8. Cross-linked high conductive membranes based on water soluble ionomer for high performance proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Jiang, Hao; Guo, Xin; Zhang, Gang; Ni, Jing; Zhao, Chengji; Liu, Zhongguo; Zhang, Liyuan; Li, Mingyu; Xu, Shuai; Na, Hui

    2013-11-01

    In this paper, a series of proton exchange membranes prepared by “Click Reaction” are reported. The cross-linked membranes are based on water soluble sulfonated poly (ether ether ketone) containing dipropenyl groups (SDPEEK-nE/nH). Compared with self-crosslinked membranes (SDPEEK-nS), this “Click” cross-linked membranes using 1,2-Ethanedithiol and 1,6-Hexanedithiol as the cross-linker exhibit extremely reduced water uptake and swelling ratio. The lowest proton conductivity at 80 °C of the “Click” cross-linked membranes reaches to 0.168 S cm-1, and the highest methanol permeability of the “Click” cross-linked SDPEEK-8E is only 4.13 × 10-7 cm2 s-1, which is 5 times lower than that of Nafion 117 membrane. All the results imply that the cross-linked membranes with novel thiol cross-linker are promising alternative material for fuel cell application.

  9. Frenkel line and solubility maximum in supercritical fluids.

    PubMed

    Yang, C; Brazhkin, V V; Dove, M T; Trachenko, K

    2015-01-01

    A new dynamic line, the Frenkel line, has recently been proposed to separate the supercritical state into rigid-liquid and nonrigid gaslike fluid. The location of the Frenkel line on the phase diagram is unknown for real fluids. Here we map the Frenkel line for three important systems: CO(2), H(2)O, and CH(4). This provides an important demarcation on the phase diagram of these systems, the demarcation that separates two distinct physical states with liquidlike and gaslike properties. We find that the Frenkel line can have a similar trend as the melting line above the critical pressure. Moreover, we discuss the relationship between unexplained solubility maxima and Frenkel line, and we propose that the Frenkel line corresponds to the optimal conditions for solubility.

  10. Ethanol effects on apparent solubility of poorly soluble drugs in simulated intestinal fluid.

    PubMed

    Fagerberg, Jonas H; Al-Tikriti, Yassir; Ragnarsson, Gert; Bergström, Christel A S

    2012-07-02

    Ethanol intake can lead to an unexpected and possibly problematic increase in the bioavailability of druglike compounds. In this work we investigated the effect of ethanol on the apparent solubility and dissolution rate of poorly soluble compounds in simulated intestinal fluid representing a preprandial state. A series of 22 structurally diverse, poorly soluble compounds were measured for apparent solubility and intrinsic dissolution rate (37 °C) in phosphate buffer pH 6.5 (PhB6.5) and fasted state simulated intestinal fluid (FaSSIF, pH 6.5) with and without ethanol at 5% v/v or 20% v/v. The obtained data were used to understand for which molecules ethanol results in an increased apparent solubility and, therefore, may increase the amount of drug absorbed. In FaSSIF20%ethanol 59% of the compounds displayed >3-fold higher apparent solubility than in pure FaSSIF, whereas the effects of 5% ethanol on solubility, in most cases, were negligible. Acidic and neutral compounds were more solubilized by the addition of ethanol than by lecithin/taurocholate aggregates, whereas bases showed a more substance-specific response to the additives in the buffer. The stronger solubilizing capacity of ethanol as compared to the mixed lipid aggregates in FaSSIF was further identified through Spearman rank analyses, which showed a stronger relationship between FaSSIF20%ethanol and PhB6.5,20%ethanol (rS of 0.97) than FaSSIF20%ethanol and FaSSIF (rS of 0.86). No relationships were found between solubility changes in media containing ethanol and single physicochemical properties, but multivariate data analysis showed that inclusion of ethanol significantly reduced the negative effect of compound lipophilicity on solubility. For this data set the higher concentration of ethanol gave a dose number (Do) <1 for 30% of the compounds that showed incomplete dissolution in FaSSIF. Significant differences were shown in the melting point, lipophilicity, and dose profiles between the compounds

  11. Highly potent soluble amyloid-β seeds in human Alzheimer brain but not cerebrospinal fluid

    PubMed Central

    Kaeser, Stephan A.; Maia, Luis F.; Portelius, Erik; Pinotsi, Dorothea; Kaminski, Clemens F.; Winkler, David T.; Maetzler, Walter; Keyvani, Kathy; Spitzer, Philipp; Wiltfang, Jens; Kaminski Schierle, Gabriele S.; Zetterberg, Henrik; Staufenbiel, Matthias; Jucker, Mathias

    2017-01-01

    The soluble fraction of brain samples from patients with Alzheimer’s disease contains highly biologically active amyloid-β seeds. In this study, we sought to assess the potency of soluble amyloid-β seeds derived from the brain and cerebrospinal fluid. Soluble Alzheimer’s disease brain extracts were serially diluted and then injected into the hippocampus of young, APP transgenic mice. Eight months later, seeded amyloid-β deposition was evident even when the hippocampus received subattomole amounts of brain-derived amyloid-β. In contrast, cerebrospinal fluid from patients with Alzheimer’s disease, which contained more than 10-fold higher levels of amyloid-β peptide than the most concentrated soluble brain extracts, did not induce detectable seeding activity in vivo. Similarly, cerebrospinal fluid from aged APP-transgenic donor mice failed to induce cerebral amyloid-β deposition. In comparison to the soluble brain fraction, cerebrospinal fluid largely lacked N-terminally truncated amyloid-β species and exhibited smaller amyloid-β-positive particles, features that may contribute to the lack of in vivo seeding by cerebrospinal fluid. Interestingly, the same cerebrospinal fluid showed at least some seeding activity in an in vitro assay. The present results indicate that the biological seeding activity of soluble amyloid-β species is orders of magnitude greater in brain extracts than in the cerebrospinal fluid. PMID:25212850

  12. A review of drug solubility in human intestinal fluids: implications for the prediction of oral absorption.

    PubMed

    Augustijns, Patrick; Wuyts, Benjamin; Hens, Bart; Annaert, Pieter; Butler, James; Brouwers, Joachim

    2014-06-16

    The purpose of this paper is to collate all recently published solubility data of orally administered drugs in human intestinal fluids (HIF) that were aspirated from the upper small intestine (duodenum and jejunum). The data set comprises in total 102 solubility values in fasted state HIF and 37 solubility values in fed state HIF, covering 59 different drugs. Despite differences in the protocol for HIF sampling and subsequent handling, this summary of HIF solubilities provides a critical reference data set to judge the value of simulated media for intestinal solubility estimation. In this regard, the review includes correlations between the reported solubilizing capacity of HIF and fasted or fed state simulated intestinal fluid (FaSSIF/FeSSIF). Correlating with HIF solubilities enables the optimal use of solubility measurements in simulated biorelevant media to obtain accurate estimates of intestinal solubility during drug development. Considering the fraction of poorly soluble new molecular entities in contemporary drug discovery, adequate prediction of intestinal solubility is critical for efficient lead optimization, early candidate profiling, and further development.

  13. Purification method development for chiral separation in supercritical fluid chromatography with the solubilities in supercritical fluid chromatographic mobile phases.

    PubMed

    Gahm, Kyung H; Tan, Helming; Liu, Jodi; Barnhart, Wesley; Eschelbach, John; Notari, Steve; Thomas, Samuel; Semin, David; Cheetham, Janet

    2008-04-14

    A comprehensive approach was applied to develop a chiral purification method for an analyte that was found to be unusually difficult to scale-up in supercritical fluid chromatography (SFC). This was performed by studying major factors such as the solubility of an analyte in SFC mobile phases, impurity profiles, and cycle time. For this case study, the solubility in SFC mobile phase was measured by a packed column technique, coupled with a novel trapping mechanism to enhance measurement precision in SFC conditions. The solubility studies in SFC mobile phases suggested a couple of possible SFC mobile phases, in which the analyte would potentially be most soluble. The SFC methods were developed to purify a sample containing 15% of an impurity, after considering impurity profiles and cycle times of several potential methods in addition to SFC mobile phase solubility. An equal volume mixture of acetonitrile and ethanol was chosen for the final purification method, since this mixture demonstrated the relatively high SFC solubility among all solvent combinations with enhanced resolution between the analyte and the impurity as well as the shortest run time. The solubility of the compound was also determined in various organic solvents using a high throughput solubility screening system to better understand relative change of solubility from neat solution to SFC mobile phases.

  14. Selectively plugging subterranean formations with a hydrocarbon soluble fluid

    SciTech Connect

    Falk, D. O.

    1984-11-13

    Highly permeable zones in a subterranean formation vertically bounded by a relatively less permeable zone are selectively plugged by injecting an emulsion of melamine and formaldehyde in an alcohol medium via a well into the highly permeable zones. The emulsion is hydrocarbon soluble are preferentially envelops the highly permeable zones where it reacts to form a resin at a temperature of from about 80/sup 0/ C. to about 250/sup 0/ C. and a pH of from about 7 to 12 and over a period of from about 1 to 4 days. The resulting resin substantially plugs the highly permeable zones in the formation.

  15. Soluble Megalin is Reduced in Cerebrospinal Fluid Samples of Alzheimer’s Disease Patients

    PubMed Central

    Spuch, Carlos; Antequera, Desireé; Pascual, Consuelo; Abilleira, Soledad; Blanco, María; Moreno-Carretero, María José; Romero-López, Jesús; Ishida, Tetsuya; Molina, Jose Antonio; Villarejo, Alberto; Bermejo-Pareja, Felix; Carro, Eva

    2015-01-01

    Megalin or low-density lipoprotein receptor-related protein-2 is a member of the low-density lipoprotein receptor family, which has been linked to Alzheimer’s disease (AD) by clearing brain amyloid β-peptide (Aβ) across the blood–cerebrospinal fluid barrier at the choroid plexus. Here, we found a soluble form of megalin secreted from choroid plexus epithelial cells. Soluble megalin levels were also localized in the human cerebrospinal fluid (CSF), being reduced in AD patients. We have also shown that soluble megalin binding to Aβ is decreased in the CSF of AD patients, suggesting that decreased sequestration of Aβ in the CSF could be associated with defective clearance of Aβ and an increase of brain Aβ levels. Thus, therapies, which increase megalin expression, at the choroid plexus and/or enhance circulating soluble megalin hold potential to control brain Aβ-related pathologies in AD. PMID:25926771

  16. Solubility of Aragonite in Aqueous Fluids at High Pressure and High Temperature

    NASA Astrophysics Data System (ADS)

    Facq, Sébastien; Daniel, Isabelle; Petitgirard, Sylvain; Cardon, Hervé; Sverjensky, Dimitri

    2014-05-01

    Deep crustal and mantle aqueous fluids play a crucial role in geologic processes occurring in the Earth's interior, especially at high PT conditions. Dissolved carbon appears to be a major element constituting these aqueous fluids, occurring under the form of molecular species (CO2, CO, CH4), ionic species such as carbonate or bicarbonate ions or some more complex organic compounds [1]. However, the nature and the content of the chemical species constituting these C-bearing aqueous fluids may strongly be affected by the environmental geologic conditions such as the pressure and the temperature range. If fluid speciation and solubility of carbonate minerals are well characterized at HT and relatively low pressure, less is evident at pressure above 2 GPa where experimental challenges make trickier speciation and solubility measurements. Thanks to recent advances in theoretical aqueous geochemistry [1-3], combined experimental and theoretical efforts allow now the investigation of speciation and solubility of carbonate minerals with pure water at higher PT conditions than previously feasible [4]. However, direct measurements of solubility of carbonate minerals at HP-HT conditions are still needed to help to the development of quantitative models of carbon transport by aqueous fluids in subduction zones and validate existing aqueous speciation model. In this study, we present recent X-ray fluorescence measurements and thermodynamic model of solubility of carbonate in aqueous fluids at pressure up to 5 GPa. The amount of dissolved aragonite in the fluid has been measured from the intensity of the Ca K-lines at the ESRF-ID27 using an externally-heated membrane-type diamond anvil cell and an incident monochromatic focused X-Ray beam at 20 keV. The combination of the XRF data on dissolution of CaCO3mineral combined to previous speciation results permits now to calculate the solubility KS of aragonite a pressure in excess of 2 GPa. [1] Manning, C. E. et al., Review in

  17. New water-soluble metal working fluids additives from phosphonic acid derivatives for aluminum alloy materials.

    PubMed

    Kohara, Ichitaro; Tomoda, Hideyuki; Watanabe, Shoji

    2007-01-01

    Water-soluble metal working fluids are used for processing of aluminum alloy materials. This short paper describes properties of new additives for water-soluble cutting fluids for aluminum alloy materials. Some alkyldiphosphonic acids were prepared with known method. Amine salts of these phosphonic acids showed anti-corrosion property for aluminum alloy materials. However, they have no hard water tolerance. Monoesters of octylphosphonic acid were prepared by the reaction of octylphosphonic acid dichloride with various alcohols in the presence of triethylamine. Amine salts of monoester of octylphosphonic acid with diethyleneglycol monomethyl ether, ethyleneglycol monomethyl ether and triethyleneglycol monomethyl ether showed both of a good anti-corrosion property for aluminum alloy materials and hard water tolerance.

  18. A New Model for the Solubility of Water+Carbon Dioxide Mixed Fluids in Magmatic Systems

    NASA Astrophysics Data System (ADS)

    Ghiorso, M. S.; Gualda, G. A.

    2012-12-01

    A model is calibrated that permits estimation of the thermodynamic properties of dissolved H2O and CO2 components in silicate liquids of magmatic composition.The model is internally consistent with thermodynamic data/model collections in both MELTS (CMP 119; 197-212) and rhyolite-MELTS (JP 53, 875-890). It is calibrated from extensive literature data collected over a broad range of melt compositions (mafic to silicic) on the solubility of water (>1225 experiments, 700°-1600°C, 0-3 GPa), carbon dioxide (>450 experiments, 1150°-1800°C, 0-3.5 GPa), and mixed H2O-CO2 fluids (>140 experiments, 950°-1650°C, 0-3 GPa) in silicate liquids. The model reproduces these solubility data without bias over the entire range of temperature, pressure and composition. At lower pressures (<1 GPa) model residuals are within experimental uncertainty, but residuals are systematically larger at more elevated pressures. The model formulation relies on the EOS of Duan and Zhang (GCA 70, 2311-2324) for estimation of thermodynamic properties of fluid end members and of the mixed fluid. Melt properties are modeled under the simplifying assumption that water disassociates to hydroxyl species in the melt and that carbon dioxide dissolves as a molecular species. Both of these assumptions have been tested against more refined approximations involving speciation, with insufficient improvement of model recovery for solubility data to warrant the additional complexity. The calibrated mixed fluid model is an extension of and is backward compatible with the thermodynamic model for dissolved water in MELTS and rhyolite-MELTS. Additional calibration parameters for the mixed fluid include the enthalpy, entropy and volume of the CO2-melt component as well as regular solution-type interaction parameters between CO2 and "anhydrous" melt components (after MELTS); a total of 12 parameters in all. We find no compelling experimental evidence to justify a CO2-H2O interaction term in the melt. In addition to

  19. Supercritical fluid particle design for poorly water-soluble drugs (review).

    PubMed

    Sun, Yongda

    2014-01-01

    Supercritical fluid particle design (SCF PD) offers a number of routes to improve solubility and dissolution rate for enhancing the bioavailability of poorly water-soluble drugs, which can be adopted through an in-depth knowledge of SCF PD processes and the molecular properties of active pharmaceutical ingredients (API) and drug delivery system (DDS). Combining with research experiences in our laboratory, this review focuses on the most recent development of different routes (nano-micron particles, polymorphic particles, composite particles and bio-drug particles) to improve solubility and dissolution rate of poorly water-soluble drugs, covering the fundamental concept of SCF and the principle of SCF PD processes which are typically used to control particle size, shape, morphology and particle form and hence enable notable improvement in the dissolution rate of the poorly water-soluble drugs. The progress of the industrialization of SCF PD processes in pharmaceutical manufacturing environment with scaled-up plant under current good manufacturing process (GMP) specification is also considered in this review.

  20. The apparent solubilizing capacity of simulated intestinal fluids for poorly water-soluble drugs.

    PubMed

    Schwebel, Hervé J; van Hoogevest, Peter; Leigh, Mathew L S; Kuentz, Martin

    2011-06-01

    Drug solubility testing in biorelevant media has become an indispensable tool in pharmaceutical development. Despite this importance, there is still an incomplete understanding of how poorly soluble compounds interact with these media. The aim of this study was to apply the concept of the apparent solubilization capacity to fasted and fed state simulated intestinal fluid (FaSSIF and FeSSIF, respectively). A set of non-ionized poorly soluble compounds was studied in biorelevant media prepared from an instantly dissolving complex (SIF(™) Powder) at 37°C. The values of the solubilization capacity were different between FaSSIF and FeSSIF but correlated. Drug inclusion into the mixed micelles was highly specific for a given compound. The ratio of the FeSSIF to FaSSIF solubility was in particular considered and discussed in terms of the apparent solubilizing capacity. The apparent solubilization concept appears to be useful for the interpretation of biorelevant solubility tests. Further studies are needed to explore acidic and basic drugs.

  1. The effect of oxygen fugacity on the solubility of carbon-oxygen fluids in basaltic melt

    NASA Technical Reports Server (NTRS)

    Pawley, Alison R.; Holloway, John R.; Mcmillan, Paul F.

    1992-01-01

    The solubility of CO2-CO fluids in a midocean ridge basalt have been measured at 1200 C, 500-1500 bar, and oxygen fugacities between NNO and NNO-4. In agreement with results of previous studies, the results reported here imply that, at least at low pressures, CO2 dissolves in basaltic melt only in the form of carbonate groups. The dissolution reaction is heterogeneous, with CO2 molecules in the fluid reacting directly with reactive oxygens in the melt to produce CO3(2-). CO, on the other hand, is insoluble, dissolving neither as carbon, molecular CO, nor CO3(2-). It is shown that, for a given pressure and temperature, the concentration of dissolved carbon-bearing species in basaltic melt in equilibrium with a carbon-oxygen fluid is proportional to the mole fraction of CO2 in the fluid, which is a function of fO2. At low pressures CO2 solubility is a linear function of CO2 fugacity at constant temperatures.

  2. Equilibrium drug solubility measurements in 96-well plates reveal similar drug solubilities in phosphate buffer pH 6.8 and human intestinal fluid.

    PubMed

    Heikkilä, Tiina; Karjalainen, Milja; Ojala, Krista; Partola, Kirsi; Lammert, Frank; Augustijns, Patrick; Urtti, Arto; Yliperttula, Marjo; Peltonen, Leena; Hirvonen, Jouni

    2011-02-28

    This study was conducted to develop a high throughput screening (HTS) method for the assessment of equilibrium solubility of drugs. Solid-state compounds were precipitated from methanol in 96-well plates, in order to eliminate the effect of co-solvent. Solubility of twenty model drugs was analyzed in water and aqueous solutions (pH 1.2 and 6.8) in 96-well plates and in shake-flasks (UV detection). The results obtained with the 96-well plate method correlated well (R(2)=0.93) between the shake-flask and 96-well plates over the wide concentration scale of 0.002-169.2mg/ml. Thereafter, the solubility tests in 96-well plates were performed using fasted state human intestinal fluid (HIF) from duodenum of healthy volunteers. The values of solubility were similar in phosphate buffer solution (pH 6.8) and HIF over the solubility range of 10(2)-10(5)μg/ml. The new 96-well plate method is useful for the screening of equilibrium drug solubility during the drug discovery process and it also allows the use of human intestinal fluid in solubility screening.

  3. Preparations and properties of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials.

    PubMed

    Watanabe, Shoji

    2008-01-01

    This short review describes various types of anti-corrosion additives of water-soluble metal working fluids for aluminum alloy materials. It is concerned with synthetic additives classified according to their functional groups; silicone compounds, carboxylic acids and dibasic acids, esters, Diels-Alder adducts, various polymers, nitrogen compounds, phosphoric esters, phosphonic acids, and others. Testing methods for water-soluble metal working fluids for aluminum alloy materials are described for a practical application in a laboratory.

  4. Composition of COH fluids at 1 GPa: an experimental study on speciation and solubility

    NASA Astrophysics Data System (ADS)

    Tiraboschi, Carla; Tumiati, Simone; Recchia, Sandro; Ulmer, Peter; Pettke, Thomas; Fumagalli, Patrizia; Poli, Stefano

    2014-05-01

    convoying evolved gases to a QMS through a heated line to avoid the condensation of water. This type of analyzer ensures superior performances in terms of selectivity of molecules to be detected, high acquisition rates and extended linear response range. The influence of dissolved solutes on fluid speciation has been evaluated by comparing experiments in the pure COH system and in the COH+forsterite system. To determine the solubility of forsterite in COH fluids we performed a second set of experiments at the same P , T and fO2 conditions above. Fluids trapped in a diamond layer were analysed by the cryogenic LA-ICP-MS technique described by Aerts et al. (2010). With this method the aqueous part of the COH fluid is frozen prior the opening and maintained frozen during the analysis to avoid any precipitation of solutes. The results will highlight the importance of fluids for the mass transport in subduction zones. Comparison between experimental data and thermodynamic calculation will also be shown. References: Aerts, M., Hack, A.C., Reusser, E., Ulmer, P. (2010) Am. Mineral. 95, 1523-1526. Newton, R.C., Manning, C.E. (2002) Geochim. Cosmochim. Ac. 66, 4165-4176.

  5. Solubility of indium-tin oxide in simulated lung and gastric fluids: Pathways for human intake.

    PubMed

    Andersen, Jens Christian Østergård; Cropp, Alastair; Paradise, Diane Caroline

    2017-02-01

    From being a metal with very limited natural distribution, indium (In) has recently become disseminated throughout the human society. Little is known of how In compounds behave in the natural environment, but recent medical studies link exposure to In compounds to elevated risk of respiratory disorders. Animal tests suggest that exposure may lead to more widespread damage in the body, notably the liver, kidneys and spleen. In this paper, we investigate the solubility of the most widely used In compound, indium-tin oxide (ITO) in simulated lung and gastric fluids in order to better understand the potential pathways for metals to be introduced into the bloodstream. Our results show significant potential for release of In and tin (Sn) in the deep parts of the lungs (artificial lysosomal fluid) and digestive tract, while the solubility in the upper parts of the lungs (the respiratory tract or tracheobronchial tree) is very low. Our study confirms that ITO is likely to remain as solid particles in the upper parts of the lungs, but that particles are likely to slowly dissolve in the deep lungs. Considering the prolonged residence time of inhaled particles in the deep lung, this environment is likely to provide the major route for uptake of In and Sn from inhaled ITO nano- and microparticles. Although dissolution through digestion may also lead to some uptake, the much shorter residence time is likely to lead to much lower risk of uptake.

  6. Modeling of CO2 solubility in single and mixed electrolyte solutions using statistical associating fluid theory

    NASA Astrophysics Data System (ADS)

    Jiang, Hao; Panagiotopoulos, Athanassios Z.; Economou, Ioannis G.

    2016-03-01

    Statistical associating fluid theory (SAFT) is used to model CO2 solubilities in single and mixed electrolyte solutions. The proposed SAFT model implements an improved mean spherical approximation in the primitive model to represent the electrostatic interactions between ions, using a parameter K to correct the excess energies ("KMSA" for short). With the KMSA formalism, the proposed model is able to describe accurately mean ionic activity coefficients and liquid densities of electrolyte solutions including Na+, K+, Ca2+, Mg2+, Cl-, Br- and SO42- from 298.15 K to 473.15 K using mostly temperature independent parameters, with sole exception being the volume of anions. CO2 is modeled as a non-associating molecule, and temperature-dependent CO2-H2O and CO2-ion cross interactions are used to obtain CO2 solubilities in H2O and in single ion electrolyte solutions. Without any additional fitting parameters, CO2 solubilities in mixed electrolyte solutions and synthetic brines are predicted, in good agreement with experimental measurements.

  7. Using Computational Fluid Dynamics to investigate the generation of soluble bedrock forms

    NASA Astrophysics Data System (ADS)

    Myre, J. M.; Covington, M. D.

    2014-12-01

    The roles and interactions of processes that generate bedforms in soluble bedrock settings are not yet fully understood. One outstanding puzzle is the morphogenesis of scallops. Current chemical theory does not allow dissolution rate to spatially vary under many of the conditions at which scallops are thought to form. This lack of variation in dissolution rate disagrees with the creation and existence of scallops for a large portion of the range of scallop sizes that are found in nature. Previous studies that have examined processes that generate bedforms using computational fluid dynamics (CFD) have made simplifying assumptions to ensure tractability. Consequently, tractability is sacrificed and some fine scale effects associated with the driving processes are not modeled. We incorporate Large-Eddy Simulation (LES) and adaptive meshing into a lattice-Boltzmann CFD method for fluid flow, chemical dissolution, and solute transport allowing relaxation of simplifying assumptions employed in previous models. These methods can model sub-grid scale turbulence and resolve the dissolution and precipitation processes occurring at the fluid-solid interface. We use this CFD model to simulate flow and dissolution over scallops and flutes to investigate the formational processes responsible for variations in dissolution rate that drive the spatio-temporal evolution of these features.

  8. Method for separating metal chelates from other materials based on solubilities in supercritical fluids

    DOEpatents

    Wai, Chien M.; Smart, Neil G.; Phelps, Cindy

    2001-01-01

    A method for separating a desired metal or metalloi from impurities using a supercritical extraction process based on solubility differences between the components, as well as the ability to vary the solvent power of the supercritical fluid, is described. The use of adduct-forming agents, such as phosphorous-containing ligands, to separate metal or metalloid chelates in such processes is further disclosed. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of .beta.-diketones; phosphine oxides, such as trialkylphosphine oxides, triarylphosphine oxides and alkylarylphosphine oxides; phosphinic acids; carboxylic acids; phosphates, such as trialkylphosphates, triarylphosphates and alkylarylphosphates; crown ethers; dithiocarbamates; phosphine sulfides; phosphorothioic acids; thiophosphinic acids; halogenated analogs of these chelating agents; and mixtures of these chelating agents. In especially preferred embodiments, at least one of the chelating agents is fluorinated.

  9. Optimization of subcritical fluid extraction of bioactive compounds using Hansen solubility parameters.

    PubMed

    Srinivas, K; King, J W; Monrad, J K; Howard, L R; Hansen, C M

    2009-08-01

    Process engineering operations in food and nutraceutical industries pertaining to the design of extraction of value-added products from biomass using pressurized liquids involve a careful selection of the solvent and optimal temperature conditions to achieve maximum yield. Complex molecular structure and limited physical property data in the literature of biological solutes extracted from biomass compounds have necessitated the process modeling of such operations. In this study, we have applied the Hansen 3-dimensional solubility parameter concept to optimize the extraction of molecularly complex solutes using subcritical fluid solvents. Hansen solubility spheres characterized by the relative energy differences (RED) have been used to characterize and quantify the solute-subcritical solvent interactions as a function of temperature. The solvent power of subcritical water and compressed hydroethanolic mixtures above their boiling points has been characterized using the above-mentioned method. The use of group contribution methods in collaboration with computerized algorithms to plot the Hansen spheres provides a quantitative prediction tool for optimizing the design of extraction conditions. The method can be used to estimate conditions for solute-solvent miscibility, an optimum temperature range for conducting extractions under pressurized conditions, and approximate extraction conditions of solutes from natural matrices.

  10. Solubility of Albite + Paragonite +/- Quartz in H2O at 1 GPa, 580° C: Implications for Metamorphic Fluids

    NASA Astrophysics Data System (ADS)

    Antignano, A.; Manning, C.

    2003-12-01

    One of the most common mineral assemblages in crustal metamorphism is feldspar + quartz; however, little is known about the solubility of this assemblage in metamorphic fluids. We measured the solubility of albite and albite+quartz in H2O at 580° C and 1.0 GPa using a piston cylinder apparatus. Experiments were conducted using Amelia albite in NaCl-graphite assemblies. Experiments were conducted using a double capsule arrangement. Inner capsules consisting of perforated 1.6 mm OD Pt capsules containing a single albite crystal were load in 3.5mm OD outer capsules containing ultra pure H2O +/- quartz. Solubility was determined by the weight loss of single albite and quartz grains after 8 hr runs. Time series experiments on this system show no variation in fluid composition or solubility after 4hrs. Albite exhibited incongruent dissolution, yielding paragonite as a husk that mantles the albite grain. The composition of the fluid was determined by mass balance as determined by the weights of albite, quartz, and paragonite. In the albite-only experiments, the concentration of total dissolved solids (TDS) were 0.628 molal, with Na, Al and Si in the fluid of 0.137, 0.081, and 0.41 molal, respectively, and Na/Al of 1.691. In the presence of quartz, there is an increase in the overall TDS to 0.777 molal. Albite-quartz experiments produce an increase in Si concentration to 0.628 molal, with lower Na and Al concentrations of 0.098 and 0.051 molal, respectively, and Na/Al of 1.922. The aqueous Si concentrations in the albite-only experiments are higher than those in fluid equilibrated with quartz (Manning, 1994, GCA, 58, 4831) at the same conditions. This is consistent with the data of Anderson and Burnham (1983, Am. J. Sci., 283-A, 283) on albite. In the quartz-present experiments results show still higher Si concentration in the fluid phase. Our results demonstrate enhanced solubility of silica in the presence of albite and albite+quartz, relative to quartz alone

  11. Statistical investigation of simulated intestinal fluid composition on the equilibrium solubility of biopharmaceutics classification system class II drugs.

    PubMed

    Khadra, Ibrahim; Zhou, Zhou; Dunn, Claire; Wilson, Clive G; Halbert, Gavin

    2015-01-25

    A drug's solubility and dissolution behaviour within the gastrointestinal tract is a key property for successful administration by the oral route and one of the key factors in the biopharmaceutics classification system. This property can be determined by investigating drug solubility in human intestinal fluid (HIF) but this is difficult to obtain and highly variable, which has led to the development of multiple simulated intestinal fluid (SIF) recipes. Using a statistical design of experiment (DoE) technique this paper has investigated the effects and interactions on equilibrium drug solubility of seven typical SIF components (sodium taurocholate, lecithin, sodium phosphate, sodium chloride, pH, pancreatin and sodium oleate) within concentration ranges relevant to human intestinal fluid values. A range of poorly soluble drugs with acidic (naproxen, indomethacin, phenytoin, and piroxicam), basic (aprepitant, carvedilol, zafirlukast, tadalafil) or neutral (fenofibrate, griseofulvin, felodipine and probucol) properties have been investigated. The equilibrium solubility results determined are comparable with literature studies of the drugs in either HIF or SIF indicating that the DoE is operating in the correct space. With the exception of pancreatin, all of the factors individually had a statistically significant influence on equilibrium solubility with variations in magnitude of effect between the acidic and basic or neutral compounds and drug specific interactions were evident. Interestingly for the neutral compounds pH was the factor with the second largest solubility effect. Around one third of all the possible factor combinations showed a significant influence on equilibrium solubility with variations in interaction significance and magnitude of effect between the acidic and basic or neutral compounds. The least number of significant media component interactions were noted for the acidic compounds with three and the greatest for the neutral compounds at seven

  12. Interleukin 2 (IL 2) inhibitor in rheumatoid synovial fluid: Correlation with prognosis and soluble IL 2 receptor levels

    SciTech Connect

    Miossec, P.; Elhamiani, M.; Chichehian, B.; D'Angeac, A.D.; Sany, J.; Hirn, M. )

    1990-03-01

    A soluble activity inhibiting over 50% of the CTLL-2 cell line response to recombinant human interleukin 2 (IL 2) was found in 17 of 29 (59%) rheumatoid synovial fluids. To study the prognosis value of this activity, 16 rheumatoid synovial fluids were collected before a radiation synovectomy of the knee with 7 mCi of 90Y. Patients with a good clinical result after the synovectomy had a lower IL 2 inhibitory activity than those with a bad or incomplete result (P less than 0.01). Levels of inhibitory activity and of soluble IL 2 receptors were correlated with each other and with the response of the synovitis to the radiation synovectomy. These results extend the clinical usefulness of soluble IL 2 receptor measurements and indicate a correlation between the immune activation of the rheumatoid synovitis and its clinical activity.

  13. Solubility of 238U radionuclide from various types of soil in synthetic gastrointestinal fluids using "US in vitro" digestion method

    NASA Astrophysics Data System (ADS)

    Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok

    2015-04-01

    238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by "US P in vitro" digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 - 0.209 ppm) than gastrointestinal fluids (0.024 - 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.

  14. Intraocular soluble intracellular adhesion molecule-1 correlates with subretinal fluid height of diabetic macular edema

    PubMed Central

    Zhu, Dan; Zhu, He; Wang, Chunyan; Yang, Dayong

    2014-01-01

    Objective: To investigate the correlations between aqueous concentrations of vascular endothelial growth factor (VEGF), monocyte chemoattractant protein-1 (MCP-1), soluble intracellular adhesion molecule-1 (sICAM-1) and diabetic macular edema (DME). Materials and Methods: VEGF, MCP-1 and sICAM-1 concentrations in aqueous humor samples of 22 patients with DME and 23 patients with cataract of a control group were measured with solid-phase chemiluminescence immunoassay. Results: Aqueous VEGF (89.2 ± 58.5 pg/ml versus 48.5 ± 27.8 pg/ml, P = 0.006), MCP-1 (684.2 ± 423.4 pg/ml versus 432.4 ± 230.4 pg/ml, P = 0.019) and sICAM-1 (3213.8 ± 2581.6 pg/ml versus 260.2 ± 212.2 pg/ml, P < 0.001) all vary significantly between DME group and control group. Maximum height of submacular fluid measured by Optical coherence tomography (OCT) was significantly associated with aqueous sICAM-1 (r = -0.45, P = 0.034). The maximum height of macular thickness measured by OCT was not significantly associated with either VEGF (P = 0.300), MCP-1 (P = 0.320) or sICAM-1 (P = 0.285). Conclusions: Our results suggest that sICAM-1 may majorly contribute to the formation of subretinal fluid in DME patients and imply that MCP-1 and sICAM-1 may be the potential therapy targets, besides VEGF. PMID:23619489

  15. Role of Phenol-Soluble Modulins in Formation of Staphylococcus aureus Biofilms in Synovial Fluid

    PubMed Central

    Dastgheyb, Sana S.; Villaruz, Amer E.; Le, Katherine Y.; Tan, Vee Y.; Duong, Anthony C.; Chatterjee, Som S.; Cheung, Gordon Y. C.; Joo, Hwang-Soo; Hickok, Noreen J.

    2015-01-01

    Staphylococcus aureus is a leading cause of prosthetic joint infections, which, as we recently showed, proceed with the involvement of biofilm-like clusters that cause recalcitrance to antibiotic treatment. Here we analyzed why these clusters grow extraordinarily large, reaching macroscopically visible extensions (>1 mm). We found that while specific S. aureus surface proteins are a prerequisite for agglomeration in synovial fluid, low activity of the Agr regulatory system and subsequent low production of the phenol-soluble modulin (PSM) surfactant peptides cause agglomerates to grow to exceptional dimensions. Our results indicate that PSMs function by disrupting interactions of biofilm matrix molecules, such as the polysaccharide intercellular adhesin (PIA), with the bacterial cell surface. Together, our findings support a two-step model of staphylococcal prosthetic joint infection: As we previously reported, interaction of S. aureus surface proteins with host matrix proteins such as fibrin initiates agglomeration; our present results show that, thereafter, the bacterial agglomerates grow to extremely large sizes owing to the lack of PSM expression under the specific conditions present in joints. Our findings provide a mechanistic explanation for the reported extreme resistance of joint infection to antibiotic treatment, lend support to the notions that Agr functionality and PSM production play a major role in defining different forms of S. aureus infection, and have important implications for antistaphylococcal therapeutic strategies. PMID:25964472

  16. Rutile Solubility in Supercritical Albite-H2O fluids: Implications for Element Mobility in Subduction Zones

    NASA Astrophysics Data System (ADS)

    Antignano, A.; Manning, C. E.

    2006-12-01

    Supercritical fluids with compositions intermediate between H2O and silicate are widely invoked as important transport agents in subduction zones. This proposal is in part motivated by the expectation that such fluids might have greater ability to dissolve and transport key trace elements at high P and T. As a test of this hypothesis, we measured the solubility of rutile (TiO2) in supercritical albite (ab, NaAlSi3O8)-H2O at 900°C, 1.5 GPa, from Xab = 0 to 0.3. At this P and T, rutile has very low solubility in H2O and there is full miscibility between H2O and ab melt. Experiments were conducted in a piston-cylinder apparatus with NaCl-graphite furnaces. In each, a 1.6 mm OD Pt inner capsule with a synthetic rutile crystal was lightly crimped and placed in a 3.5 OD Pt capsule with ultra pure H2O and powdered Amelia albite. Equilibrium was achieved after 4 hrs. Solubility was determined by the weight loss of the rutile grain. Quench textures consistent with supercritical behavior were observed in all runs. Residual corundum is present in the H2O-rich runs, but it decreases with increasing ab concentration. Results show that rutile solubility initially rises sharply with increasing ab concentration from 38 ppm in pure H2O to 739 ppm at Xab =0.05 (44 wt%). With further increase in ab, rutile solubility increases only slightly, to 922 ppm at Xab =0.25 (83 wt%). No significant solubility increase was noted near the critical compositon (~50 wt% ab). Our results show that intermediate fluids do not significantly enhance Ti solubility above dilute silicate-bearing solutions. The presence of residual Al2O3 and the sharp initial rise in rutile solubility at low Xab imply that, by analogy with silicate melts, Ti is present in solution as Na-Ti-O complexes (e.g., Dickenson and Hess, 1985, GCA, 49, 2289). However, the lack of residual corundum at high Xab suggests a transiton to different Ti species, perhaps aqueous NaAlSi3O8-like complexes. Our results give insight into rutile

  17. Refractive index and solubility control of para-cymene solutions for index-matched fluid-structure interaction studies

    NASA Astrophysics Data System (ADS)

    Fort, Charles; Fu, Christopher D.; Weichselbaum, Noah A.; Bardet, Philippe M.

    2015-12-01

    To deploy optical diagnostics such as particle image velocimetry or planar laser-induced fluorescence (PLIF) in complex geometries, it is beneficial to use index-matched facilities. A binary mixture of para-cymene and cinnamaldehyde provides a viable option for matching the refractive index of acrylic, a common material for scaled models and test sections. This fluid is particularly appropriate for large-scale facilities and when a low-density and low-viscosity fluid is sought, such as in fluid-structure interaction studies. This binary solution has relatively low kinematic viscosity and density; its use enables the experimentalist to select operating temperature and to increase fluorescence signal in PLIF experiments. Measurements of spectral and temperature dependence of refractive index, density, and kinematic viscosity are reported. The effect of the binary mixture on solubility control of Rhodamine 6G is also characterized.

  18. Thermodynamic equilibrium solubility measurements in simulated fluids by 96-well plate method in early drug discovery.

    PubMed

    Bharate, Sonali S; Vishwakarma, Ram A

    2015-04-01

    An early prediction of solubility in physiological media (PBS, SGF and SIF) is useful to predict qualitatively bioavailability and absorption of lead candidates. Despite of the availability of multiple solubility estimation methods, none of the reported method involves simplified fixed protocol for diverse set of compounds. Therefore, a simple and medium-throughput solubility estimation protocol is highly desirable during lead optimization stage. The present work introduces a rapid method for assessment of thermodynamic equilibrium solubility of compounds in aqueous media using 96-well microplate. The developed protocol is straightforward to set up and takes advantage of the sensitivity of UV spectroscopy. The compound, in stock solution in methanol, is introduced in microgram quantities into microplate wells followed by drying at an ambient temperature. Microplates were shaken upon addition of test media and the supernatant was analyzed by UV method. A plot of absorbance versus concentration of a sample provides saturation point, which is thermodynamic equilibrium solubility of a sample. The established protocol was validated using a large panel of commercially available drugs and with conventional miniaturized shake flask method (r(2)>0.84). Additionally, the statistically significant QSPR models were established using experimental solubility values of 52 compounds.

  19. Water-soluble metal working fluids additives derived from the esters of acid anhydrides with higher alcohols for aluminum alloy materials.

    PubMed

    Yamamoto, Syutaro; Tomoda, Hideyuki; Watanabe, Shoji

    2007-01-01

    Water-soluble metal working fluids are used for processing of aluminum alloy materials. This short article describes properties of new additives in water-soluble metal working fluids for aluminum alloy materials. Many half esters or diesters were prepared from the reactions of higher alcohols with acid anhydrides. Interestingly, diesters of PTMG (tetrahydrofuran oligomer, MW = 650 and 1000) and polybutylene oxide (MW = 650) with maleic anhydride and succinic anhydride showed both of an excellent anti-corrosion property for aluminum alloy and a good hard water tolerance. The industrial soluble type processing oils including these additives also showed anti-corrosion property and hard water tolerance.

  20. Rutile solubility in NaF–NaCl–KCl-bearing aqueous fluids at 0.5–2.79GPa and 250–650°C

    DOE PAGES

    Tanis, Elizabeth A.; Simon, Adam; Zhang, Youxue; ...

    2016-01-14

    The complex nature of trace element mobility in subduction zone environments is thought to be primarily controlled by fluid-rock interactions, episodic behavior of fluids released, mineral assemblages, and element partitioning during phase transformations and mineral breakdown throughout the transition from hydrated basalt to blueschist to eclogite. Quantitative data that constrain the partitioning of trace elements between fluid(s) and mineral(s) are required in order to model trace element mobility during prograde and retrograde metamorphic fluid evolution in subduction environments. The stability of rutile has been proposed to control the mobility of HFSE during subduction, accounting for the observed depletion of Nbmore » and Ta in arc magmas. Recent experimental studies demonstrate that the solubility of rutile in aqueous fluids at temperatures >700 degrees C and pressures <2 GPa increases by several orders of magnitude relative to pure H2O as the concentrations of ligands (e.g., F and Cl) in the fluid increase. Considering that prograde devolatilization in arcs begins at similar to 300 degrees C, there is a need for quantitative constraints on rutile solubility and the partitioning of HFSE between rutile and aqueous fluid over a wider range of temperature and pressure than is currently available. In this study, new experimental data are presented that quantify the solubility of rutile in aqueous fluids from 0.5 to 2.79 GPa and 250 to 650 degrees C. Rutile solubility was determined by using synchrotron X-ray fluorescence to measure the concentration of Zr in an aqueous fluid saturated with a Zr-bearing rutile crystal within a hydrothermal diamond anvil cell. At the PT conditions of the experiments, published diffusion data indicate that Zr is effectively immobile (log D-Zr similar to 10(-25) m(2)/s at 650 degrees C and similar to 10(-30) m(2)/s at 250 degrees C) with diffusion length-scales of <0.2 mu m in rutile for our run durations (<10 h). Hence, the Zr

  1. Rutile solubility in NaF–NaCl–KCl-bearing aqueous fluids at 0.5–2.79GPa and 250–650°C

    SciTech Connect

    Tanis, Elizabeth A.; Simon, Adam; Zhang, Youxue; Chow, Paul; Xiao, Yuming; Hanchar, John M.; Tschauner, Oliver; Shen, Guoyin

    2016-01-14

    The complex nature of trace element mobility in subduction zone environments is thought to be primarily controlled by fluid-rock interactions, episodic behavior of fluids released, mineral assemblages, and element partitioning during phase transformations and mineral breakdown throughout the transition from hydrated basalt to blueschist to eclogite. Quantitative data that constrain the partitioning of trace elements between fluid(s) and mineral(s) are required in order to model trace element mobility during prograde and retrograde metamorphic fluid evolution in subduction environments. The stability of rutile has been proposed to control the mobility of HFSE during subduction, accounting for the observed depletion of Nb and Ta in arc magmas. Recent experimental studies demonstrate that the solubility of rutile in aqueous fluids at temperatures >700 degrees C and pressures <2 GPa increases by several orders of magnitude relative to pure H2O as the concentrations of ligands (e.g., F and Cl) in the fluid increase. Considering that prograde devolatilization in arcs begins at similar to 300 degrees C, there is a need for quantitative constraints on rutile solubility and the partitioning of HFSE between rutile and aqueous fluid over a wider range of temperature and pressure than is currently available. In this study, new experimental data are presented that quantify the solubility of rutile in aqueous fluids from 0.5 to 2.79 GPa and 250 to 650 degrees C. Rutile solubility was determined by using synchrotron X-ray fluorescence to measure the concentration of Zr in an aqueous fluid saturated with a Zr-bearing rutile crystal within a hydrothermal diamond anvil cell. At the PT conditions of the experiments, published diffusion data indicate that Zr is effectively immobile (log D-Zr similar to 10(-25) m(2)/s at 650 degrees C and similar to 10(-30) m(2)/s at 250 degrees C) with diffusion length-scales of <0.2 mu m in rutile for our run durations (<10 h). Hence, the Zr/Ti ratio

  2. Rutile solubility in NaF-NaCl-KCl-bearing aqueous fluids at 0.5-2.79 GPa and 250-650 °C

    NASA Astrophysics Data System (ADS)

    Tanis, Elizabeth A.; Simon, Adam; Zhang, Youxue; Chow, Paul; Xiao, Yuming; Hanchar, John M.; Tschauner, Oliver; Shen, Guoyin

    2016-03-01

    The complex nature of trace element mobility in subduction zone environments is thought to be primarily controlled by fluid-rock interactions, episodic behavior of fluids released, mineral assemblages, and element partitioning during phase transformations and mineral breakdown throughout the transition from hydrated basalt to blueschist to eclogite. Quantitative data that constrain the partitioning of trace elements between fluid(s) and mineral(s) are required in order to model trace element mobility during prograde and retrograde metamorphic fluid evolution in subduction environments. The stability of rutile has been proposed to control the mobility of HFSE during subduction, accounting for the observed depletion of Nb and Ta in arc magmas. Recent experimental studies demonstrate that the solubility of rutile in aqueous fluids at temperatures >700 °C and pressures <2 GPa increases by several orders of magnitude relative to pure H2O as the concentrations of ligands (e.g., F and Cl) in the fluid increase. Considering that prograde devolatilization in arcs begins at ∼300 °C, there is a need for quantitative constraints on rutile solubility and the partitioning of HFSE between rutile and aqueous fluid over a wider range of temperature and pressure than is currently available. In this study, new experimental data are presented that quantify the solubility of rutile in aqueous fluids from 0.5 to 2.79 GPa and 250 to 650 °C. Rutile solubility was determined by using synchrotron X-ray fluorescence to measure the concentration of Zr in an aqueous fluid saturated with a Zr-bearing rutile crystal within a hydrothermal diamond anvil cell. At the PT conditions of the experiments, published diffusion data indicate that Zr is effectively immobile (log DZr ∼10-25 m2/s at 650 °C and ∼10-30 m2/s at 250 °C) with diffusion length-scales of <0.2 μm in rutile for our run durations (<10 h). Hence, the Zr/Ti ratio of the starting rutile, which was quantified, does not change

  3. Soluble and Catalytically Active Endothelin Converting Enzyme-1 is Present in Cerebrospinal Fluid of Subarachnoid Hemorrhage Patients

    PubMed Central

    Kuruppu, Sanjaya; Chou, Sherry H.-Y.; Feske, Steven K.; Suh, Sarah; Hanchapola, Iresha; Lo, Eng H.; Ning, MingMing; Smith, A. Ian

    2014-01-01

    Endothelin converting Enzyme-1 (ECE-1) is essential for the production of Endothelin-1 (ET-1), which is associated with vasospasm following subarachnoid hemorrhage (SAH). We have previously demonstrated the presence of a catalytically active soluble form of ECE-1 in the media of endothelial cells. We aimed to determine if this form of ECE-1 exists in vivo, in cerebrospinal fluid (CSF) of SAH patients. We examined CSF taken from SAH subjects for the presence of soluble ECE-1 using a bradykinin based quenched fluorescent substrate assay. We obtained further confirmation by characterizing the CSF mediated cleavage products of BigET-1 and BigET18–34 (6 μg/ml) using mass spectrometry. The specificity of cleavage was confirmed using the ECE-1 inhibitor CGS35066 5nmol/L. SAH CSF samples had mean ECE-1 activity of 0.127 ± 0.037 μmols of substrate cleaved/μl of CSF/24 h. The C-terminal peptides generated upon the cleavage of BigET-1 and BigET18–34 were detected 48 h after incubation of these substrates with CSF. Cleavage of these substrates was inhibited by CGS35066. Results of Western blots also produced strong evidence for the presence of truncated soluble ECE-1 in CSF. These results strongly suggest the presence of a truncated but catalytically active form of ECE-1 in the CSF of SAH subjects. Further studies are necessary to determine the biological significance of soluble ECE-1 in CSF of SAH subjects, including an association with vasospasm after SAH. PMID:23816989

  4. Oxidized As (V) in fore-arc mantle serpentinites: Transfer of fluid-soluble elements from slabs to arc magmas

    NASA Astrophysics Data System (ADS)

    Hattori, K. H.; Takahashi, Y.; Guillot, S.; Johanson, B.

    2004-12-01

    Fluids released from subducting slabs and sediments hydrate the overlying peridotites in mantle wedges. Such hydrated peridotites (serpentinites) are enriched in fluid-soluble elements, although insoluble elements show the refractory geochemical signature. The enrichment pattern of serpentinites is similar to that of arc magmas (Hattori & Guillot, 2003 in Geology). Arsenic is one of the most enriched soluble elements, reaching greater than 1000 times of the primitive mantle value. We examined the speciation and occurrence of As in serpentinites to understand how such a highly mobile element can be transferred from subducting slabs to arc magmas via mantle wedges. Our study used serpentinites associated with the Tso Morari eclogitic rocks in the Indus Suture Zone of Himalaya. They represent the hydrated peridotites at the base of mantle wedge beneath the margin of Eurasia and were exhumed from the depth of about 100 km during the active subduction of the Indian continental margin. The serpentinites are made up of antigorite, chromite, minor talc. It contains As ranging from 6 to 275 ppm and S up to 51 ppm, but most have S below detection limit, 4 ppm. X-ray absorption spectroscopy data show that As is mostly As(V) and combined with oxygen, although Minute grains of As-bearing sulphides and arsenides are identified in samples. The fractions of As(V), calculated from the X-ray absorption near-edge structure, are greater in samples with higher As contents. High proportion of As(V) in the fore-arc mantle serpentinites contasts with high As(III) in the serpentinite at the base of the Nidar ophiolite. The source of As (V) in the serpentinites is most likely As adsorped on Fe- and Mn-oxides in subducted sediments and slabs. It was released during the subduction of slab and sediments at low temperatures, \\< 350° C, and shallow depths, \\< 25 km. Continuous flux of water from slabs at the base of the mantle wedge likely maintained As in oxidized condition. Arsenic in the

  5. Solubility of Two Root-End Filling Materials over Different Time Periods in Synthetic Tissue Fluid: a Comparative Study

    PubMed Central

    Shojaee, Nooshin Sadat; Sahebi, Safoora; Karami, Elahe; Sobhnamayan, Fereshte

    2015-01-01

    Statement of the Problem Insolubility is an important criterion for an ideal root-end filling material to both prevent any microleakage between the root canal and the periradicular space and provide sealing ability. Purpose Many recent studies have shown that mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) have acceptable sealing ability. The purpose of this in vitro study was to evaluate the solubility of these root-end filling materials. Materials and Method Forty stainless steel ring moulds with an internal diameter of 10±1 mm and a height of 2±0.1 mm were selected. Samples of MTA and CEM were mixed according to the manufacturer’s instructions and inserted into the moulds. The specimens were divided into 4 experimental groups and kept in synthetic tissue fluid (STF) for 2 different time periods (7 and 28 days). The control group contained 8 empty rings. The moulds’ weights were recorded before and after immersion in STF. The changes in the weight of the samples were measured and compared using a two- way ANOVA test at a significance level of 5%. Specimens were evaluated with scanning electron microscopy (SEM) at a magnification of 500×. Results There was no significant difference in weight changes between MTA and CEM samples (p> 0.05). Conclusion MTA and CEM have similar solubility in STF in different time periods. PMID:26331148

  6. Release of a Poorly Soluble Drug from Hydrophobically Modified Poly (Acrylic Acid) in Simulated Intestinal Fluids

    PubMed Central

    Knöös, Patrik

    2015-01-01

    A large part of new pharmaceutical substances are characterized by a poor solubility and high hydrophobicity, which might lead to a difference in drug adsorption between fasted and fed patients. We have previously evaluated the release of hydrophobic drugs from tablets based on Pemulen TR2 and showed that the release can be manipulated by adding surfactants. Here we further evaluate the possibility to use Pemulen TR2 in controlled release tablet formulations containing a poorly soluble substance, griseofulvin. The release is evaluated in simulated intestinal media that model the fasted state (FaSSIF medium) or fed state (FeSSIF). The rheology of polymer gels is studied in separate experiments, in order to gain more information on possible interactions. The release of griseofulvin in tablets without surfactant varied greatly and the slowest release were observed in FeSSIF. Addition of SDS to the tablets eliminated the differences and all tablets showed a slow linear release, which is of obvious relevance for robust drug delivery. Comparing the data from the release studies and the rheology experiment showed that the effects on the release from the different media could to a large extent be rationalised as a consequence of the interactions between the polymer and the surfactants in the media. The study shows that Pemulen TR2 is a candidate for controlled release formulations in which addition of surfactant provides a way to eliminate food effects on the release profile. However, the formulation used needs to be designed to give a faster release rate than the tablets currently investigated. PMID:26473964

  7. THE RELATION OF INFLAMMATION TO THE MOLECULAR STRUCTURE OF CARBON COMPOUNDS SOLUBLE IN THE FLUIDS OF THE BODY.

    PubMed

    OPIE, E L

    1965-04-01

    The peritoneal, like the pleural cavity, gives opportunity to measure with adequate accuracy the activity of inflammatory reactions defined by movement of fluid within the cavity, by migration of leucocytes into it, and by exudation of proteins from the plasma. The activity of inflammatory reactions caused by saccharides or by alcohols that were tested varied in accord with their molecular weight, the osmotic pressure maintained by solutions of corresponding concentration, their boiling point, or by other colligative properties. Blood serum or globulin in the concentration with which it occurs in blood serum injected into the peritoneal cavity caused changes which differed little from those caused by physiological salt solution. Protein with molecular weight as low as that of cytochrome C (12,000) or ovalbumin (45,000) when in dilute solution (1 per cent) were rapidly absorbed, whereas trypsin and chymotrypsin under the same conditions caused very active inflammatory reactions because they set free amino acids and perhaps polypeptides with amino acids in short chains. The activity of inflammatory reactions caused by carbon compounds soluble in body fluids varied in accord with their colligative properties.

  8. Hematite solubility in NaCl- and CaSiO3-bearing aqueous fluids at 10 kbar and 800 C

    NASA Astrophysics Data System (ADS)

    Wykes, J. L.; Manning, C. E.

    2005-12-01

    A distinguishing characteristic of arc-related magmas is their high oxidation state, manifest as elevated Fe3+/Fe(total) relative to OIB and MORB. However, there is no consensus on the process and agents responsible for arc-magma oxidation. The subducting slab represents an obvious source of oxidized material, particularly lithologies rich in ferric iron-bearing minerals and sulfates produced through seawater interaction. Fe3+ and SO4}2- represent the most readily available agents for mantle-wedge oxidation. Hydrous fluids and brines equilibrated with these oxidized portions of the slab may be effective oxidizing agents. To assess this possibility, we measured the solubility of hematite in NaCl-H2O fluids at 10 kbar and 800°C. Experiments were conducted in a piston-cylinder apparatus with graphite-NaCl furnace assemblies. Solubility was determined by weight loss of either sintered reagent-grade hematite pellets or rounded specular hematite fragments (1 wt% TiO2). The ultra-fine grained reagent hematite tended to recrystallize during experiments; however, in some cases the final pellets were quite friable, leading to material loss during weighing. These experiments were discounted because their weight changes were spurious. Two methods were employed to control fO2. Either a sealed Mn2O3-filled Pt capsule was run inside the fluid filled outer capsule, buffering at the Mn2O3-Mn3O4 equilibrium, or the outer capsule was packed in MnO2 powder inside the graphite heater assembly, acting as a H2 sink. External MnO2 resulted in some recrystallization of the Pt capsules. However, hematite solubility was identical for both methods, suggesting both techniques control fO2 to a similar degree. The solubility of hematite in H2O-NaCl fluids was measured from 0-72 wt% NaCl. Hematite solubility in pure H2O was 5.5×10-4 molal total Fe, with a detection limit of 8.3×10-5. With increasing NaCl conentration, hematite solubility increased from ~0.001 molal total Fe at 13 wt% NaCl to

  9. Soluble Toll-Like Receptors 2 and 4 in Cerebrospinal Fluid of Patients with Acute Hydrocephalus following Aneurysmal Subarachnoid Haemorrhage

    PubMed Central

    Sokół, Bartosz; Jankowski, Roman; Hołysz, Marcin; Więckowska, Barbara; Jagodziński, Paweł

    2016-01-01

    Background Toll-like receptor (TLR) signalling begins early in subarachnoid haemorrhage (SAH), and plays a key role in inflammation following cerebral aneurysm rupture. Available studies suggest significance of endogenous first-line blockers of a TLR pathway—soluble TLR2 and 4. Methods Eighteen patients with SAH and acute hydrocephalus underwent endovascular coiling and ventriculostomy; sTLR2 and 4 levels were assayed in cerebrospinal fluid (CSF) collected on post-SAH days 0–3, 5, and 10–12. Release kinetics were defined. CSF levels of sTLR2 and 4 were compared with a control group and correlated with the clinical status on admission, the findings on imaging, the degree of systemic inflammation and the outcome following treatment. Results None of study group showed detectable levels of sTLR2 and 4 on post-SAH day 0–3. 13 patients showed increased levels in subsequent samples. In five SAH patients sTLR2 and 4 levels remained undetectable; no distinctive features of this group were found. On post-SAH day 5 the strongest correlation was found between sTLR2 level and haemoglobin level on admission (cc = -0.498, P = 0.037). On post-SAH day 10–12 the strongest correlation was revealed between sTLR2 and treatment outcome (cc = -0.501, P = 0.076). Remaining correlations with treatment outcome, status at admission, imaging findings and inflammatory markers on post-SAH day 5 and 10–12 were negligible or low (-0.5 ≤ cc ≤ 0.5). Conclusions In the majority of cases, rupture of a cerebral aneurysm leads to delayed release of soluble TLR forms into CSF. sTLR2 and 4 seem to have minor role in human post-SAH inflammation due to delayed release kinetics and low levels of these protein. PMID:27223696

  10. Solubility of {sup 238}U radionuclide from various types of soil in synthetic gastrointestinal fluids using “US in vitro” digestion method

    SciTech Connect

    Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok

    2015-04-29

    238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by “US P in vitro” digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 – 0.209 ppm) than gastrointestinal fluids (0.024 – 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.

  11. Rutile solubility in H2O-NaAlSi3O8 fluids at High T and P: Implications form HFSE mobility in Subduction zones

    NASA Astrophysics Data System (ADS)

    Antignano, A.; Manning, C. E.

    2005-12-01

    The trace element signatures of arc magmas are characterized by HFSE depletion relative to the LILE. Rutile, a common accessory phase in high-pressure assemblages, is an important reservoir for the HFSE and is often invoked to explain the HFSE depletion of arc magmas. This model is in part based on experimental studies, which show that rutile has very low solubility in pure H2O. However, rutile is also a common accessory to eclogite-facies vein assemblages of albite, paragonite and quartz, which likely precipitated from slab-derived fluids. This observation requires either that fluid fluxes were unrealistically high, or that current estimates of Ti solubility are too low. A possible solution to this problem is that dissolved silicate components can enhance Ti solubility via complexing. To test this, we measured the solubility of rutile in H2O-NaAlSi3O8 (albite) bearing fluids at high T and P. Experiments were conducted using a piston-cylinder apparatus with NaCl-graphite furnaces. A single synthetic rutile crystal was loaded into a 1.6 mm OD Pt inner capsule, which was lightly crimped and then placed in a 3.5 OD Pt outer capsule with ultra pure H2O and powdered Amelia albite. Solubility was determined by the weight loss of the rutile grain after 10 hrs. A time series demonstrates that equilibrium is achieved after 8-10 hrs. Preliminary results at 800°C, 1.0 GPa, show that rutile solubility rises with increasing NaAlSi3O8 concentration from 1.15(12) millimolal at 2.18 wt% NaAlSi3O8 to 3.77(13) at 8.80 wt% NaAlSi3O8. Corundum mats + fluid are observed in 3.4-8.80 wt% NaAlSi3O8 and are interpreted to be the result of incongruent dissolution of albite. Quenched melt spheres where observed in an experiment containing ~15 wt% NaAlSi3O8, but not at 8.80 wt%. At 8.80 wt% NaAlSi3O8, rutile solubility is higher by a factor of 6 relative to that in pure H2O. Our results suggest that TiO2 solubility is increased by complexing with Na-Al-Si-bearing fluid components. It has

  12. Evaluating Soluble EMMPRIN as a Marker of Disease Activity in Multiple Sclerosis: Studies of Serum and Cerebrospinal Fluid

    PubMed Central

    Kaushik, Deepak K.; Yong, Heather Y. F.; Hahn, Jennifer N.; Silva, Claudia; Casha, Steven; Hurlbert, R. John; Jacques, Francois H.; Lisak, Robert; Khan, Omar; Ionete, Carolina; Larochelle, Catherine; Prat, Alex; Bar-Or, Amit; Yong, V. Wee

    2016-01-01

    Extracellular matrix metalloproteinase inducer (EMMPRIN, CD147) is an inducer of matrix metalloproteinases and has roles in leukocyte activation and migration. We reported previously that in MS and its animal model, experimental autoimmune encephalomyelitis, cell surface-associated EMMPRIN was significantly elevated in leukocytes around inflammatory perivascular cuffs in the CNS. In this study we report that activated T-cells can secrete soluble form of EMMPRIN (sEMMPRIN) upon activation. As sEMMPRIN is also present in biological fluids, we determined whether sEMMPRIN is altered in the CSF and sera of MS subjects. Sera from individuals without neurological conditions served as controls, while CSFs collected from subjects undergoing discectomy, and without evidence of CNS pathology, were used as a comparator group. We found that serum levels of sEMMPRIN from clinically stable MS patients or other inflammatory conditions did not differ from control subjects. Paired serum and CSF samples demonstrated poor correlation of sEMMPRIN. Interestingly, sEMMPRIN levels were approximately 60% higher in CSFs compared to sera. sEMMPRIN CSF levels were significantly higher in secondary progressive compared to primary progressive subjects. Thus we conclude that measurement of sEMMPRIN in serum is not informative for disease activity in MS. The differential expression of sEMMPRIN in the CSF of primary and secondary progressive MS invites hypotheses of the still undefined roles of EMMPRIN in the CNS. PMID:27727297

  13. Genetic regulation of amniotic fluid TNF-alpha and soluble TNF receptor concentrations affected by race and preterm birth.

    PubMed

    Menon, Ramkumar; Velez, Digna R; Morgan, Nicole; Lombardi, Salvatore J; Fortunato, Stephen J; Williams, Scott M

    2008-10-01

    Racial disparity in spontaneous preterm birth (PTB) between African Americans and Caucasians in the US is unexplained, but is probably related to differences in amniotic fluid (AF) inflammatory cytokine profiles. Therefore, this study analyzed the association of 34 single nucleotide polymorphisms (SNPs) in TNF-alpha and its receptor genes (TNFR1 and TNFR2) with AF TNF-alpha and soluble TNF receptor (R1 and R2) concentrations in PTB. Samples consisted of African American and Caucasian cases (PTB), and controls (term birth) for which both cytokine, and maternal and fetal genotype data were available. Analyses were performed with genotype, case, and maker-status interaction in the model for log transformed cytokine concentrations. In Caucasians, two interactions between genotype and pregnancy outcome associated with cytokine concentrations, whereas 14 gene variants in African Americans showed interactions with pregnancy outcome, and 13 showed association with genetic markers. In conclusion, cytokine concentrations in African American preterm births can be partially explained by interactions between pregnancy outcome, SNPs and infection. This does not appear to be the case in Caucasians. These findings may be important in understanding disparity in rates of PTB between the two populations.

  14. Levels of Soluble Receptor for Advanced Glycation End Products in Bronchoalveolar Lavage Fluid in Patients with Various Inflammatory Lung Diseases

    PubMed Central

    Kamo, Tetsuro; Tasaka, Sadatomo; Tokuda, Yuriko; Suzuki, Shoji; Asakura, Takanori; Yagi, Kazuma; Namkoong, Ho; Ishii, Makoto; Hasegawa, Naoki; Betsuyaku, Tomoko

    2015-01-01

    Receptor for advanced glycation end products (RAGE) is a multiligand receptor of S100/calgranulins, high-mobility group box 1, and others, and it is associated with the pathogenesis of various inflammatory and circulatory diseases. The soluble form of RAGE (sRAGE) is a decoy receptor and competitively inhibits membrane-bound RAGE activation. In this study, we measured sRAGE levels in bronchoalveolar lavage fluid (BALF) of 78 patients, including 41 with interstitial pneumonia, 11 with sarcoidosis, 9 with respiratory infection, 7 with ARDS, 5 with lung cancer, and 5 with vasculitis. Among them, sRAGE was detectable in BALF of 73 patients (94%). In patients with ARDS and vasculitis, the sRAGE levels were significantly higher than in the control subjects and those with interstitial pneumonia. The sRAGE levels were positively correlated with total cell counts in BALF and serum levels of surfactant protein-D, lactate dehydrogenase, and C-reactive protein. There was an inverse correlation between PaO2/FIO2 ratio and sRAGE levels. These results indicate that sRAGE in BALF might be considered as a biomarker of lung inflammatory disorders, especially ARDS and vasculitis. PMID:27147899

  15. Characterizing metal(loid) solubility in airborne PM10, PM2.5 and PM1 in Frankfurt, Germany using simulated lung fluids

    NASA Astrophysics Data System (ADS)

    Wiseman, Clare L. S.; Zereini, Fathi

    2014-06-01

    The purpose of this study is to assess the solubility of traffic-related metal(loid)s associated with airborne PM of human health concern, employing a physiologically-based extraction test with simulated lung fluids (artificial lysosomal fluid (ALF) and Gamble's solution). Airborne PM (PM10, PM2.5 and PM1) samples were collected in Frankfurt am Main, Germany, using a high volume sampler. Following extraction of the soluble metal(loid) fractions, sample filters were digested with a high pressure asher. Metal(loid) concentrations (As, Ce, Co, Cr, Cu, Mn, Ni, Pb, Sb, Ti and V) were determined in extracts and digests per ICP-Q-MS. All metal(loid)s occurred at detectable concentrations in the three airborne PM fractions. Copper was the most abundant element in mass terms, with mean concentrations of 105 and 53 ng/m3 in PM10 and PM2.5, respectively. Many of the metal(loid)s were observed to be soluble in simulated lung fluids, with Cu, As, V and Sb demonstrating the highest overall mobility in airborne PM. For instance, all four elements associated with PM10 had a solubility of >80% in ALF (24 h). Clearly, solubility is strongly pH dependent, as reflected by the higher relative mobility of samples extracted with the acidic ALF. Given their demonstrated solubility, this study provides indirect evidence that a number of toxic metal(loid)s are likely to possess an enhanced pulmonary toxic potential upon their inhalation. The co-presence of many toxic elements of concern in airborne PM suggests an assessment of health risk must consider the possible interactive impacts of multi-element exposures.

  16. The effect of CO2 and N2 on phase relations, fluid composition, and quartz solubility in amphibolite facies metamorphic rocks

    NASA Astrophysics Data System (ADS)

    Artimenko, Margaret V.

    2016-12-01

    Phase equilibria in the system SiO2-TiO2-Al2O3-Fe2O3-MnO-MgO-CaO-Na2O-K2O-P2O5-H2O-CO2-N2 are calculated to illustrate phase relations in amphibolite facies metasediments over a wide range of X[H2O-CO2-N2] conditions at 600 °C and 4.4 kb. Calculations are performed using the Gibbs free energy minimization technique. Results are presented in plots showing stable mineral assemblages as a function of total carbon in the system at varying water (a_{{{{H}}2 {{O}}}} = 1) content in the presence/absence of N2 in the fluid. The calculations indicate that the typical assemblage plagioclase—quartz—biotite—ilmenite—garnet—apatite is restricted to the rocks with CO2 saturation and X_{{{{H}}_{ 2} {{O}}}} higher than 60% in the fluid. Significant decrease in X_{{{{CO}}2 }} favors the stability of muscovite rather than garnet, whereas the decrease in X_{{{{H}}_{ 2} {{O}}}} leads to the stability of microcline over all range of X_{{{{CO}}2 }}. This paper also presents the composition and parameters (pH, Eh) of the fluid equilibrated with mineral assemblage. It is shown that the presence of low concentrations of N2 causes the fluid to consist of two phases when an aqueous supercritical solution (AS) coexists with a supercritical fluid with gas-like properties (SF). At high concentration of N2, the fluid consists of SF alone; in the absence of nitrogen, the fluid consists of AS alone. The solubility of monomer SiO 2 0 and dimer Si2O 4 0 decreases with increasing CO2 and after CO2 saturation point is held constant. The magnitude of the silica solubility at CO2 saturation depends upon the water content in AS. The effect of nitrogen on quartz solubility has been demonstrated to be negligible.

  17. Ex vivo permeability experiments in excised rat intestinal tissue and in vitro solubility measurements in aspirated human intestinal fluids support age-dependent oral drug absorption.

    PubMed

    Annaert, Pieter; Brouwers, Joachim; Bijnens, Ann; Lammert, Frank; Tack, Jan; Augustijns, Patrick

    2010-01-31

    The possible influence of advanced age on intestinal drug absorption was investigated by determining the effects of aging on (i) solubility of model drugs in human intestinal fluids (HIF) obtained from two age groups (18-25 years; 62-72 years); and (ii) transepithelial permeation of model drugs across intestinal tissue excised from young, adult and old rats. Average equilibrium solubility values for 10 poorly soluble compounds in HIF aspirated from both age groups showed high interindividual variability, but did not reveal significant differences. Characterization of the HIF from both age groups demonstrated comparable pH profiles, while concentrations of individual bile salts showed pronounced variability between individuals, however without statistical differences between age groups. Transepithelial permeation of the transcellular probe metoprolol was significantly increased in old rats (38 weeks) compared to the younger age groups, while the modulatory role of P-glycoprotein in transepithelial talinolol transport was observed in adult and old rats but not in young rats. In conclusion, age-dependent permeability of intestinal tissue (rather than age-dependent luminal drug solubility) may contribute to altered intestinal drug absorption in older patients compared to young adults.

  18. Modeling of the solubility of a one-component H2O or CO2 fluid in silicate liquids

    NASA Astrophysics Data System (ADS)

    Papale, Paolo

    The modeling of the solubility of water and carbon dioxide in silicate liquids (flash problem) is performed by assuming mechanical, thermal, and chemical equilibrium between the liquid magma and the gas phase. The liquid phase is treated as a mixture of ten silicate components+H2O or CO2, and the gas phase as a pure H2O or CO2. A general model for the solubility of a volatile component in a liquid is adopted. This requires the definition of a mixing equation for the excess Gibbs free energy of the liquid phase and an appropriate reference state for the dissolved volatile. To constrain the model parameters and identify the most appropriate form of the solubility equations for each dissolved volatile, a large number of experimental solubility determinations (640 for H2O and 263 for CO2) have been used. These determinations cover a large region of the P-T-composition space of interest. The resultant water and carbon dioxide solubility models differ in that the water model is regular and isometric, and the carbon dioxide model is regular and non-isometric. This difference is consistent with the different speciation modalities of the two volatiles in the silicate liquids, producing a composition-independent partial molar volume of dissolved water and a composition-dependent partial molar volume of dissolved carbon dioxide. The H2O solubility model may be applied to natural magmas of virtually any composition in the P-T range 0.1 MPa-1 GPa and > 1000 K, whereas the CO2 solubility model may be applied to several GPa pressures. The general consistency of the water solubility data and their relatively large number as compared to the calibrated model parameters (11) contrast with the large inconsistencies of the carbon dioxide solubility determinations and their low number with respect to the CO2 model parameters (22). As a result, most of the solubility data in the database are reproduced within 10% of approximation in the case of water, and 30% in the case of carbon

  19. Nanofibrous membrane-based absorption refrigeration system

    SciTech Connect

    Isfahani, RN; Sampath, K; Moghaddam, S

    2013-12-01

    This paper presents a study on the efficacy of highly porous nanofibrous membranes for application in membrane-based absorbers and desorbers. Permeability studies showed that membranes with a pore size greater than about one micron have a sufficient permeability for application in the absorber heat exchanger. Membranes with smaller pores were found to be adequate for the desorber heat exchanger. The membranes were implemented in experimental membrane-based absorber and desorber modules and successfully tested. Parametric studies were conducted on both absorber and desorber processes. Studies on the absorption process were focused on the effects of water vapor pressure, cooling water temperature, and the solution velocity on the absorption rate. Desorption studies were conducted on the effects of wall temperature, vapor and solution pressures, and the solution velocity on the desorption rate. Significantly higher absorption and desorption rates than in the falling film absorbers and desorbers were achieved. Published by Elsevier Ltd.

  20. Solubility of aliphatic hydrocarbons in piperidinium ionic liquids: measurements and modeling in terms of perturbed-chain statistical associating fluid theory and nonrandom hydrogen-bonding theory.

    PubMed

    Paduszyński, Kamil; Domańska, Urszula

    2011-11-03

    Ionic liquids (ILs) reveal many unique properties which make them very interesting for applications in modern "green" technologies. For that reason, detailed knowledge about correlations between the ions' structure, their combinations, and the bulk properties is of great importance. That knowledge can be accessed by reliable measurements and modeling of systems with ILs in terms of various theoretical approaches. In this paper we report new experimental results on liquid-liquid equilibrium (LLE) measurements of 10 binary systems composed of piperidinium ILs [namely, 1-propyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide and 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide] and aliphatic hydrocarbons (n-hexane, n-heptane, n-octane, cyclohexane, and cycloheptane). Moreover, new results on liquid density of pure 1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide are presented. Upper critical solution temperature type of phase behavior for all studied systems was observed. Decrease of solubility of n-alkane with an increase of its alkyl chain length and increase of solubility when changing linear into cyclic structure of hydrocarbon were detected. LLE modeling of investigated systems was performed in terms of two modern theories, namely, perturbed-chain statistical associating fluid theory (PC-SAFT) and nonrandom hydrogen-bonding theory (NRHB). Pure fluid parameters of the models were obtained from fitting of experimental liquid density and solubility parameter data at ambient pressure and tested against high pressure densities. Then literature values of activity coefficients of n-alkanes and cycloalkanes at infinitely diluted mixtures with ILs were used to optimize binary interaction parameters of the models. Finally, the LLE phase diagrams were calculated with average absolute relative deviations of 4.1% and 3.4% of the IL mole fraction for PC-SAFT and NRHB, respectively. The PC-SAFT and NRHB models were both able to capture phase

  1. The speciation of soluble sulphur compounds in bacterial culture fluids by X-ray absorption near edge structure spectroscopy.

    PubMed

    Franz, Bettina; Lichtenberg, Henning; Hormes, Josef; Dahl, Christiane; Prange, Alexander

    2009-11-01

    Over the last decade X-ray absorption near edge structure (XANES) spectroscopy has been used in an increasing number of microbiological studies. In addition to other applications it has served as a valuable tool for the investigation of the sulphur globules deposited intra- or extracellularly by certain photo- and chemotrophic sulphur-oxidizing (Sox) bacteria. For XANES measurements, these deposits can easily be concentrated by filtration or sedimentation through centrifugation. However, during oxidative metabolism of reduced sulphur compounds, such as sulphide or thiosulphate, sulphur deposits are not the only intermediates formed. Soluble intermediates such as sulphite may also be produced and released into the medium. In this study, we explored the potential of XANES spectroscopy for the detection and speciation of sulphur compounds in culture supernatants of the phototrophic purple sulphur bacterium Allochromatium vinosum. More specifically, we investigated A. vinosum DeltasoxY, a strain with an in frame deletion of the soxY gene. This gene encodes an essential component of the thiosulphate-oxidizing Sox enzyme complex. Improved sample preparation techniques developed for the DeltasoxY strain allowed for the first time not only the qualitative but also the quantitative analysis of bacterial culture supernatants by XANES spectroscopy. The results thus obtained verified and supplemented conventional HPLC analysis of soluble sulphur compounds. Sulphite and also oxidized organic sulphur compounds were shown by XANES spectroscopy to be present, some of which were not seen when standard HPLC protocols were used.

  2. Solubility of uranium and thorium from a healing earth in synthetic gut fluids: a case study for use in dose assessments.

    PubMed

    Höllriegl, Vera; Li, Wei Bo; Leopold, Karsten; Gerstmann, Udo; Oeh, Uwe

    2010-11-01

    The aim of this case study was to estimate the bioaccessibility of uranium ((238)U) and thorium ((232)Th) from a healing earth by analysing the solubility of these radionuclides in synthetic gastric and intestinal fluids. An easy applicable in vitro test system was used to investigate the fractional mobilization of the soil contaminants being potentially available for absorption under human in vivo conditions. These findings provided the basis for a prospective dose assessment. The solubility experiments were performed using two different in vitro digestion methods. The concentrations of (238)U and (232)Th in the solutions extracted from the soil were measured by inductively coupled plasma mass spectrometry (ICP-MS). The dissolved fractions in the synthetic gastrointestinal fluid ranged in average from 10.3% to 13.8% for (238)U and from 0.3% to 1.6% for (232)Th, respectively, depending on the digestion method. Subsequently, the committed effective doses from intake of (238)U and (232)Th after ingestion of the healing earth during 1 year were evaluated for adult persons. Thereby ingestion dose coefficients calculated as a function of bioaccessibility were used. The dose assessments ranged between 4.3 × 10(-7)-1.9 × 10(-6) Sv y(-1) for (238)U and 5.6 × 10(-7)-3.3 × 10(-6) Sv y(-1) for (232)Th, respectively. On the basis of the assumptions and estimations made, the present work indicates a relatively low radiation risk due to (238)U and (232)Th after internal exposure of the healing earth.

  3. Novel spray freeze-drying technique using four-fluid nozzle-development of organic solvent system to expand its application to poorly water soluble drugs.

    PubMed

    Niwa, Toshiyuki; Shimabara, Hiroko; Danjo, Kazumi

    2010-02-01

    Spray freeze-drying (SFD) technique using four-fluid nozzle (4N), which is a novel particle design technique previously developed by authors, has been further developed to expand its application in pharmaceutical industry. The organic solvent was utilized as a spray solvent to dissolve the poorly soluble drug instead of conventional aqueous solution. Acetonitrile solution of the drug and aqueous solution of the polymeric carrier were separately and simultaneously atomized through 4N, and collided each other at the tip of nozzle edge. The spray mists were immediately frozen in the liquid nitrogen to form a suspension. Then, the iced droplets were freeze-dried to prepare the composite particles of the drug and carrier according to our proprietary method developed before. The resultant composite particles with phenytoin prepared by using acetonitrile (4N-SFD-MeCN system) were deeply characterized compared to those using aqueous solution (4N-SFD-aqua system) from morphological and physicochemical perspectives. The characteristic porous structure was observed in 4N-SFD-MeCN particles as well as 4N-SFD-aqua particles. However, it was found that the size and quantity of pore in 4N-SFD-MeCN particles were smaller than those of 4N-SFD-aqua particles. As a result, the former particles had 2- to 3-times smaller specific surface area than the latter particles independent of the type of carrier loaded. The slight difference of release profiles from the particles prepared between both systems was discussed from the microscopically structural viewpoint. In addition, ciclosporin was applied to organic solvent SFD system because this drug was poorly water soluble and cannot be applied to conventional aqueous SFD system. The release profiles from SFD particles were dramatically improved compared to the bulk material, suggesting that the new SFD technique using organic solvent has potential to develop the novel solubilized formulation for poorly water-soluble active pharmaceutical

  4. Original research paper. A superior preparation method for daidzein-hydroxypropyl-β-cyclodextrin complexes with improved solubility and dissolution: Supercritical fluid process.

    PubMed

    Pan, Hao; Wang, Han-Bing; Yu, Yi-Bin; Cheng, Bing-Chao; Wang, Xiao-Yu; Li, Ying

    2017-03-01

    Advantages of the supercritical fluid (SCF) process compared to the conventional solution stirring method (CSSM) in the preparation of daidzein-hydroxypropyl-β-cyclodextrin (HPβCD) complexes were investigated. Formation of daidzein/ HPβCD inclusion complexes was confirmed by Fourier transformed-infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Particle size, inclusion yield, drug solubility and dissolution of daidzein/HPβCD complexes were evaluated. Compared to CSSM, the SCF process resulted in higher inclusion yield and higher solubility. Also, extended dissolution of daidzein from the SCF processed HPβCD inclusion complexes was observed, with only 22.94 % released in 45 min, compared to its rapid release from those prepared by CSSM, with 98.25 % drug release in 15 min. This extended release of daidzein from SCF prepared inclusion complexes was necessary to avoid drug precipitation and improve drug solubilisation in the gastrointestinal tract. The results showed that the SCF process is a superior preparation method for daidzein-hydroxypropyl-β-cyclodextrin complexes.

  5. A review of chromatographic methods for the determination of water- and fat-soluble vitamins in biological fluids.

    PubMed

    Karaźniewicz-Łada, Marta; Główka, Anna

    2016-01-01

    Vitamins are an essential element of nutrition and thus contribute to human health. Vitamins catalyze many biochemical reactions and their lack or excess can cause health problems. Therefore, monitoring vitamin concentrations in plasma or other biological fluids may be useful in the diagnosis of various disorders as well as in the treatment process. Several chromatographic methods have been developed for the determination of these compounds in biological samples, including high-performance liquid chromatography with UV and fluorescence detection. Recently, high-performance liquid chromatography with tandem mass spectrometry methods have been widely used for the determination of vitamins in complex matrices because of their high sensitivity and selectivity. This method requires preconditioning of samples for analysis, including protein precipitation and/or various extraction techniques. The choice of method may depend on the desired cost, convenience, turnaround time, specificity, and accuracy of the information to be obtained. This article reviews the recently reported chromatographic methods used for determination of vitamins in biological fluids. Relevant papers published mostly during the last 5 years were identified by an extensive PubMed search using appropriate keywords. Particular attention was given to the preparation steps and extraction techniques. This report may be helpful in the selection of procedures that are appropriate for certain types of biological materials and analytes.

  6. Simultaneous analysis for water- and fat-soluble vitamins by a novel single chromatography technique unifying supercritical fluid chromatography and liquid chromatography.

    PubMed

    Taguchi, Kaori; Fukusaki, Eiichiro; Bamba, Takeshi

    2014-10-03

    Chromatography techniques usually use a single state in the mobile phase, such as liquid, gas, or supercritical fluid. Chromatographers manage one of these techniques for their purpose but are sometimes required to use multiple methods, or even worse, multiple techniques when the target compounds have a wide range of chemical properties. To overcome this challenge, we developed a single method covering a diverse compound range by means of a "unified" chromatography which completely bridges supercritical fluid chromatography and liquid chromatography. In our method, the phase state was continuously changed in the following order; supercritical, subcritical and liquid. Moreover, the gradient of the mobile phase starting at almost 100% CO2 was replaced with 100% methanol at the end completely. As a result, this approach achieved further extension of the polarity range of the mobile phase in a single run, and successfully enabled the simultaneous analysis of fat- and water-soluble vitamins with a wide logP range of -2.11 to 10.12. Furthermore, the 17 vitamins were exceptionally separated in 4min. Our results indicated that the use of dense CO2 and the replacement of CO2 by methanol are practical approaches in unified chromatography covering diverse compounds. Additionally, this is a first report to apply the novel approach to unified chromatography, and can open another door for diverse compound analysis in a single chromatographic technique with single injection, single column and single system.

  7. Effect of salts on the solubility of ionic liquids in water: experimental and electrolyte Perturbed-Chain Statistical Associating Fluid Theory†

    PubMed Central

    Mohammad, Sultan; Schleinitz, Miko; Coutinhoa, João A. P.; Freire, Mara G.

    2016-01-01

    Due to scarce available experimental data, as well as due to the absence of predictive models, the influence of salts on the solubility of ionic liquids (ILs) in water is still poorly understood. To this end, this work addresses the solubility of the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4C1im][NTf2]), at 298.15 K and 0.1 MPa, in aqueous salt solutions (from 0.1 to 1.5 mol kg−1). At salt molalities higher than 0.2 mol kg−1, all salts caused salting-out of [C4C1im][NTf2] from aqueous solution with their strength decreasing in the following order: Al2(SO4)3 > ZnSO4 > K3C6H5O7 > KNaC4H4O6 > K3PO4 > Mg(CH3CO2)2 > K2HPO4 > MgSO4 > KH2PO4 > KCH3CO2. Some of these salts lead however to the salting-in of [C4C1im][NTf2] in aqueous medium at salt molalities lower than 0.20 mol kg−1. To attempt the development of a model able to describe the salt effects, comprising both the salting-in and salting-out phenomena observed, the electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-SAFT) was applied using ion-specific parameters. The gathered experimental data was modelled using ePC-SAFT parameters complemented by fitting a single binary parameter between K+ and the IL-ions to the IL solubility in K3PO4 aqueous solutions. Based on this approach, the description of anion-specific salting-out effects of the remaining potassium salts was found to be in good agreement with experimental data. Remarkably, ePC-SAFT is even able to predict the salting-in effect induced by K2HPO4, based on the single K+/IL-ions binary parameter which was fitted to an exclusively salting-out effect promoted by K3PO4. Finally, ePC-SAFT was applied to predict the influence of other sodium salts on the [C4C1im][NTf2] solubility in water, with experimental data taken from literature, leading to an excellent description of the liquid–liquid phase behaviour. PMID:26575280

  8. Effect of salts on the solubility of ionic liquids in water: experimental and electrolyte Perturbed-Chain Statistical Associating Fluid Theory.

    PubMed

    Neves, Catarina M S S; Held, Christoph; Mohammad, Sultan; Schleinitz, Miko; Coutinho, João A P; Freire, Mara G

    2015-12-21

    Due to scarce available experimental data, as well as due to the absence of predictive models, the influence of salts on the solubility of ionic liquids (ILs) in water is still poorly understood. To this end, this work addresses the solubility of the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C4C1im][NTf2]), at 298.15 K and 0.1 MPa, in aqueous salt solutions (from 0.1 to 1.5 mol kg(-1)). At salt molalities higher than 0.2 mol kg(-1), all salts caused salting-out of [C4C1im][NTf2] from aqueous solution with their strength decreasing in the following order: Al2(SO4)3 > ZnSO4 > K3C6H5O7 > KNaC4H4O6 > K3PO4 > Mg(CH3CO2)2 > K2HPO4 > MgSO4 > KH2PO4 > KCH3CO2. Some of these salts lead however to the salting-in of [C4C1im][NTf2] in aqueous medium at salt molalities lower than 0.2 mol kg(-1). To attempt the development of a model able to describe the salt effects, comprising both the salting-in and salting-out phenomena observed, the electrolyte Perturbed-Chain Statistical Associating Fluid Theory (ePC-SAFT) was applied using ion-specific parameters. The gathered experimental data was modelled using ePC-SAFT parameters complemented by fitting a single binary parameter between K(+) and the IL-ions to the IL solubility in K3PO4 aqueous solutions. Based on this approach, the description of anion-specific salting-out effects of the remaining potassium salts was found to be in good agreement with experimental data. Remarkably, ePC-SAFT is even able to predict the salting-in effect induced by K2HPO4, based on the single K(+)/IL-ions binary parameter which was fitted to an exclusively salting-out effect promoted by K3PO4. Finally, ePC-SAFT was applied to predict the influence of other sodium salts on the [C4C1im][NTf2] solubility in water, with experimental data taken from literature, leading to an excellent description of the liquid-liquid phase behaviour.

  9. Significant Solubility of Carbon dioxide in Soluplus® Facilitates Impregnation of Ibuprofen Using Supercritical Fluid Technology.

    PubMed

    Obaidat, Rana; Alnaief, Mohammed; Jaeger, Philip

    2017-04-04

    Treatment of Soluplus® with supercritical carbon dioxide allows promising applications in preparing dispersions of amorphous solids. Several characterization techniques ware employed to reveal this effect, including CO2 gas sorption under high pressure and physicochemical characterizations techniques. A gravimetric method was used to determine the solubility of carbon dioxide in the polymer at elevated pressure. The following physicochemical characterizations were used: thermal analysis, X-ray diffraction, Fourier transform, infra-red spectroscopy and scanning electron microscopy. Drug loading of the polymer with ibuprofen as a model drug was also investigated. The proposed treatment with supercritical carbon dioxide allows to prepare solid solutions of Soluplus® in less than two hours at temperatures that do not exceed 45°C, which is a great advantage to be used for thermolabile drugs. The advantages of using this technology for Soluplus® formulations lies behind the high sorption capability of carbon dioxide inside the polymer. This will ensure rapid diffusion of the dissolved/dispersed drug inside the polymer under process conditions and rapid precipitation of the drug in the amorphous form during depressurization accompanied by foaming of the polymer.

  10. Membrane-based wet electrostatic precipitation

    SciTech Connect

    David J. Bayless; Liming Shi; Gregory Kremer; Ben J. Stuart; James Reynolds; John Caine

    2005-06-01

    Emissions of fine particulate matter, PM2.5, in both primary and secondary form, are difficult to capture in typical dry electrostatic precipitators (ESPs). Wet (or waterbased) ESPs are well suited for collection of acid aerosols and fine particulates because of greater corona power and virtually no re-entrainment. However, field disruptions because of spraying (misting) of water, formation of dry spots (channeling), and collector surface corrosion limit the applicability of current wet ESPs in the control of secondary PM2.5. Researchers at Ohio University have patented novel membrane collection surfaces to address these problems. Water-based cleaning in membrane collectors made of corrosion-resistant fibers is facilitated by capillary action between the fibers, maintaining an even distribution of water. This paper presents collection efficiency results of lab-scale and pilot-scale testing at First Energy's Bruce Mansfield Plant for the membrane-based wet ESP. The data indicate that a membrane wet ESP was more effective at collecting fine particulates, acid aerosols, and oxidized mercury than the metal-plate wet ESP, even with {approximately}15% less collecting area. 15 refs., 7 figs., 6 tabs.

  11. Membrane-based wet electrostatic precipitation.

    PubMed

    Bayless, David J; Shi, Liming; Kremer, Gregory; Stuart, Ben J; Reynolds, James; Caine, John

    2005-06-01

    Emissions of fine particulate matter, PM2.5, in both primary and secondary form, are difficult to capture in typical dry electrostatic precipitators (ESPs). Wet (or water-based) ESPs are well suited for collection of acid aerosols and fine particulates because of greater corona power and virtually no re-entrainment. However, field disruptions because of spraying (misting) of water, formation of dry spots (channeling), and collector surface corrosion limit the applicability of current wet ESPs in the control of secondary PM2.5. Researchers at Ohio University have patented novel membrane collection surfaces to address these problems. Water-based cleaning in membrane collectors made of corrosion-resistant fibers is facilitated by capillary action between the fibers, maintaining an even distribution of water. This paper presents collection efficiency results of lab-scale and pilot-scale testing at FirstEnergy's Bruce Mansfield Plant for the membrane-based wet ESP. The data indicate that a membrane wet ESP was more effective at collecting fine particulates, acid aerosols, and oxidized mercury than the metal-plate wet ESP, even with approximately 15% less collecting area.

  12. Ammonium in aqueous fluids to 600 °C, 1.3 GPa: A spectroscopic study on the effects on fluid properties, silica solubility, and K-feldspar to muscovite reactions

    NASA Astrophysics Data System (ADS)

    Schmidt, Christian; Watenphul, Anke

    2010-12-01

    The behavior of ammonium, NH 4+, in aqueous systems was studied based on Raman spectroscopic experiments to 600 °C and about 1.3 GPa. Spectra obtained at ambient conditions revealed a strong reduction of the dynamic three-dimensional network of water with addition of ammonium chloride, particularly at small solute concentrations. The differential scattering cross section of the ν 1-NH 4+ Raman band in these solutions was found to be similar to that of salammoniac. The Raman band of silica monomers at ˜780 cm -1 was present in all spectra of the fluid at high temperatures in hydrothermal diamond-anvil cell experiments with H 2O ± NH 4Cl and quartz or the assemblage quartz + kyanite + K-feldspar ± muscovite/tobelite. However, these spectra indicated that dissolved silica is less polymerized in ammonium chloride solutions than in comparable experiments with water. Quantification based on the normalized integrated intensity of the H 4SiO 40 band showed that the silica solubility in experiments with H 2O + NH 4Cl was significantly lower than that in equimolal NaCl solutions. This suggests that ammonium causes a stronger decrease in the activity of water in chloridic solutions than sodium. The Raman spectra of the fluid also showed that a significant fraction of ammonium was converted to ammonia, NH 3, in all experiments at temperatures above 300 °C. This indicates a shift towards acidic conditions for experiments without a buffering mineral assemblage. The estimated pH of the fluid was ˜2 at 600 °C, 0.26 GPa, 6.6 m initial NH 4Cl, based on the ratio of the integrated ν 1-NH 3 and ν 1-NH 4+ intensities and the HCl 0 dissociation constant. The NH 3/NH 4+ ratio increased with temperature and decreased with pressure. This implies that more ammonium should be retained in K-bearing minerals coexisting with chloridic fluids upon high- P low- T metamorphism. At 500 °C, 0.73 GPa, ammonium partitions preferentially into the fluid, as constrained from infrared

  13. Soluble complement receptor type 1 in serum and cerebrospinal fluid of patients with Guillain-Barré syndrome and multiple sclerosis.

    PubMed

    Vedeler, C A; Matre, R; Sadallah, S; Schifferli, J

    1996-06-01

    Activation of complement is critically involved in inflammatory reactions in both Guillain-Barré syndrome (GBS) and multiple sclerosis (MS). Soluble human complement receptor 1 (sCR1) blocks complement activation by both classical and alternative pathways. We studied serum and cerebrospinal fluid (CSF) concentrations of sCR1 in 23 patients with GBS, 27 patients with MS and 30 controls. No significant differences were found between patients and controls. Transient liver affection probably caused high serum sCR1 levels in two patients with GBS. The serum and CSF sCR1 levels were not correlated to the disease activity of GBS and MS, nor to the relapsing-remitting or chronic-progressive forms of MS. In GBS the CSF sCR1 levels correlated with the CSF total protein concentrations (r = 0.9, P < 0.01), suggesting that sCR1 leaks from serum into CSF via a damaged blood-nerve barrier. The serum sCR1 levels in GBS were slightly higher than in MS (P < 0.05). Whether this reflects changes in the release or consumption of sCR1 in these patients is at present unknown.

  14. Supercritical fluid chromatographic resolution of water soluble isomeric carboxyl/amine terminated peptides facilitated via mobile phase water and ion pair formation.

    PubMed

    Patel, M A; Riley, F; Ashraf-Khorassani, M; Taylor, L T

    2012-04-13

    Both analytical scale and preparative scale packed column supercritical fluid chromatography (SFC) have found widespread applicability for chiral separations of multiple polar pharmaceutical candidates. However, SFC is rapidly becoming an achiral technique. More specifically, ion pair SFC is finding greater utility for separation of ionic analytes such as amine salts and organic sulfonates. The key to this success is, in part, the incorporation of additives such as trifluoroacetic acid and ammonium acetate into the mobile phase in association with a wide variety of both bonded silica stationary phases and high purity bare silica. Ion pairing SFC coupled with evaporative light scattering detection and mass spectrometric detection is presented here for the separation of water soluble, uncapped, isomeric peptide pairs that differ in amino acid arrangement. The separation is best achieved on either diol-bonded silica or bare silica with 1-5% (w/w) water as a significant ingredient in the mobile phase. Nitrogenous stationary phases such as 2-ethylpyridine, which had been very successful for the separation of capped peptides failed to yield the desired separation regardless of the mobile phase composition. A HILIC type retention mechanism is postulated for the separation of both isomeric uncapped peptide pairs.

  15. The transition from dilute electrolyte aqueous solution to molten salt in geologic fluids: evidence from calcite solubility measurement in Na-halide solutions at 8 kbar and 700 °C

    NASA Astrophysics Data System (ADS)

    Galvez, M.; Manning, C. E.

    2014-12-01

    Fluids are major agents of mass and heat transport in the Earth crust and in subduction zones. Fluid inclusions, metasomatic field relations and experimental evidence suggest that these fluids can contain important ligands, including halogens, sulfates, sulfides, etc. The ligands participate in the complexation of rock-forming elements during mineral dissolution to high-T and P. Although models of high- element metasomatism typically assume that H2O dominates the fluid's solvent properties, however, H2O may be a relatively minor component in the high-PT brines that are increasingly recognized in the lower crust and mantle. Understanding the evolution of solubility mechanisms as fluids change from dilute aqueous solutions to salt-rich brines is hindered by the absence of experimental investigation of this transition. To address this problem, we conducted experiments on the solubility of calcite in sodium-halide solutions at 8 kbar and 700 °C using hydrothermal piston-cylinder weight-loss methods. Investigated salts were NaL , where L=F, Cl, Br, I, at concentrations ranging from 0.15 molal to 20 molal (XNaL ~ 0.3). At these conditions, the fluid is a single supercritical fluid phase . Run durations were 4 to 20 hours. Results demonstrate systematic trends with ligand ionic size, and locate a major mechanistic transition in the vicinity of XNaL~ 0.1 for all calcite-H2O-NaL systems. At lower than this critical composition (Xcrit), calcite solubility displays a pronounced concave shape indicating involvement of water during the dissolution process. At XNaL> Xcrit , the shape becomes convex with no apparent effect of decreased H2O activity in the fluid. The solubility patterns suggest that the solvent properties are dominated by those of H2O at XNaL< Xcrit, but at XNaL> Xcrit, H2O is a solute in a solution behaving as a molten salt. Geological evidence suggests that salt concentrations may reach values similar to or greater than Xcrit in a range of metamorphic and

  16. The calculated solubility of platinum and gold in oxygen-saturated fluids and the genesis of platinum-palladium and gold mineralization in the unconformity-related uranium deposits

    NASA Astrophysics Data System (ADS)

    Jaireth, S.

    1992-01-01

    Thermodynamic calculations on the solubility of platinum and gold indicate that saline (1 m NaCl), fluids saturated with atmospheric oxygen can transport geologically realistic concentrations of platinum-group-elements (PGE), gold, and uranium as chloro-complexes. A number of calculations involving fluid-rock interaction suggest that the oxygen-saturated fluids flowing through rocks containing quartz, muscovite, kaolinite, magnetite and hematite, initially oxidize any magnetite to hematite, allowing subsequent batches of ore fluids to retain their high oxidation state. During their migration through the aquifer, the oxidizing fluids would move the oxidation-reduction interface deeper into the aquifer, leaching and redepositing platinum and gold. The redissolution of earlier precipitated platinum and gold depends on the fluid/ rock ratio and the associated increase in the oxidation state. Therefore, lowering of fluid/rock ratios and/or mixing of the oxidized fluids with a large amount of reduced fluid will precipitate uranium, PGE, and gold. It is suggested that this model can explain the genesis of gold and PGE mineralization in the unconformity-related uranium deposits of the Alligator Rivers Uranium Field in the Northern Territory, Australia.

  17. A new sandwich immunoassay for detection of the α-secretase cleaved, soluble amyloid-β protein precursor in cerebrospinal fluid and serum.

    PubMed

    Taverna, Mara; Straub, Tobias; Hampel, Harald; Rujescu, Dan; Lichtenthaler, Stefan F

    2013-01-01

    Alzheimer's disease (AD) is the most common neurodegenerative disorder. Frequently used diagnostic biomarkers are amyloid-β42 (Aβ42), tau, and phospho-tau, which are measured in cerebrospinal fluid (CSF), and allow a reasonable, but not full, separation of AD patients and controls. Besides Aβ42, additional proteolytic cleavage products of the amyloid-β protein precursor (AβPP) have been investigated as potential biomarkers. This includes the α-secretase cleaved soluble AβPP ectodomain (sAβPPα). However, some studies found a reduction of sAβPPα, whereas other studies reported an increase of sAβPPα in the CSF of AD patients. The divergent findings may result from the detection of sAβPPα with antibodies, such as 6E10, which do not exclusively detect sAβPPα, but also the alternative β-secretase cleavage product sAβPPβ'. Here, we used the sAβPPα-specific antibody 14D6 and developed an ELISA-like sandwich immunoassay. The assay specifically detected sAβPPα in cell culture supernatants, in human CSF and even in serum, which is more readily accessible than CSF. The assay was used to analyze sAβPPα levels in CSF and serum of AD patients and controls. The assay detected a mild, but significant increase in sAβPPα in the CSF of AD patients compared to non-demented controls, while a mild reduction was observed in serum. The 14D6 assay in CSF allowed a better separation of AD patients from controls compared to the 6E10 antibody. Taken together, the new assay is widely applicable for specific sAβPPα measurement in culture media, CSF, and serum.

  18. Amniotic fluid soluble myeloid differentiation-2 (sMD-2) as regulator of intra-amniotic inflammation in infection-induced preterm birth

    PubMed Central

    Dulay, Antonette T.; Buhimschi, Catalin S.; Zhao, Guomao; Oliver, Emily; Abdel-Razeq, Sonya S.; Shook, Lydia L.; Bahtiyar, Mert O.; Buhimschi, Irina A.

    2015-01-01

    Problem TLR4 mediates host responses to pathogens through a mechanism that involves protein myeloid differentiation-2 (MD-2) and its soluble form sMD-2. The role of sMD2 in intra-amniotic inflammation induced preterm birth has not been previously explored. Method of study Human amniotic fluid (AF) sMD-2 was studied by Western blotting in 152 AF samples of patients who had an amniocentesis to rule-out infection (yes infection, n=50; no infection, n=50) or women with normal pregnancy outcome (2nd trimester genetic karyotyping, n=26; 3rd trimester lung maturity testing, n=26). Histologic localization and mRNA expression of MD2 in fetal membranes were studied by immunohistochemistry and RT-PCR. The ability of fetal membrane to release sMD-2 and inflammatory cytokines was studied in-vitro. Results Human AF contains three sMD-2 proteoforms whose levels of expression were lower at term. Intra-amniotic infection up-regulated sMD-2. MD-2 mRNA and immunohistochemistry findings concurred. In vitro, LPS and monensin increased while cycloheximide decreased sMD-2 production. Recombinant sMD-2 modulated TNF-α and IL-6 levels in a dose and time-dependent fashion. Conclusion sMD2 proteoforms are constitutively present in human AF. The intensity of the intra-amniotic inflammatory response to bacteria or perhaps to other TLR4 ligands may be facilitated through synthesis and release of sMD2 by the amniochorion. PMID:25605324

  19. Amniotic Fluid Angiopoietin-1, Angiopoietin-2, and Soluble Receptor Tunica Interna Endothelial Cell Kinase-2 Levels and Regulation in Normal Pregnancy and Intraamniotic Inflammation-Induced Preterm Birth

    PubMed Central

    Buhimschi, Catalin S.; Bhandari, Vineet; Dulay, Antonette T.; Thung, Stephen; Razeq, Sonya S. Abdel-; Rosenberg, Victor; Han, Christina S.; Ali, Unzila A.; Zambrano, Eduardo; Zhao, Guomao; Funai, Edmund F.; Buhimschi, Irina A.

    2010-01-01

    Background: Angiopoietin-1 (Ang-1) and Ang-2 act selectively on endothelial cells by engaging the Tunica interna endothelial cell kinase-2 (Tie2) receptor. A soluble form of Tie2 (sTie2) blocks angiopoietin bioactivity. Objective: The aim of the study was to characterize changes and expression patterns of Ang-1, Ang-2, and sTie2 in amniotic fluid (AF) and placenta during human pregnancy and intraamniotic inflammation (IAI)-induced preterm birth. Design and Setting: We conducted a cross-sectional study at a tertiary university hospital. Patients: AF levels of Ang-1, Ang-2, and sTie2 were evaluated in 176 women during second trimester (n = 40), third trimester (n = 37), and preterm labor (positive IAI, n = 50; negative IAI, n = 49). Placenta and cord blood of select women were analyzed. Main Outcome Measures: Ang-1, Ang-2, sTie2, and IL-6 were evaluated by ELISA. Real-time PCR measured Ang-1, Ang-2, and Tie2 placental mRNA levels. Placenta was immunostained for Ang-1 and Ang-2. Placental explant cultures were stimulated with lipopolysaccharide, Pam3Cys, and modulators of protein synthesis/secretion (cycloheximide, monensin, and brefeldin A). Results: In normal pregnancy, the levels and ratios of AF Ang-1, Ang-2, and sTie2 varied with gestational age (GA) (P < 0.001). PCR revealed corresponding changes in placental Ang-1 and Ang-2, but not Tie2, mRNA. IAI raised AF Ang-1, Ang-2, and sTie2 above the expected level for GA without affecting their placental mRNA. Ang-2 immunoreactivity appeared enhanced in areas of villous edema. AF Ang-2/Ang-1 ratio was an important determinant of cord blood IL-6 (P < 0.001). Ex-vivo, sTie2 release was increased by Golgi disrupting but not bacterial mimic agents. Conclusions: Ang-1, Ang-2, and sTie2 are physiological constituents of AF that are GA and IAI regulated. Ang-2/Ang-1 ratio may play a role in modulating the fetal inflammatory response to IAI. Placental sTie2 shedding likely involves a Golgi-mediated mechanism. PMID:20410222

  20. Mineral oil soluble borate compositions

    SciTech Connect

    Dulat, J.

    1981-09-15

    Alkali metal borates are reacted with fatty acids or oils in the presence of a low hlb value surfactant to give a stable mineral oil-soluble product. Mineral oil containing the borate can be used as a cutting fluid.

  1. A thermodynamic model for calculating methane solubility, density and gas phase composition of methane-bearing aqueous fluids from 273 to 523 K and from 1 to 2000 bar

    NASA Astrophysics Data System (ADS)

    Duan, Zhenhao; Mao, Shide

    2006-07-01

    A thermodynamic model is presented to calculate methane solubility, liquid phase density and gas phase composition of the H 2O-CH 4 and H 2O-CH 4-NaCl systems from 273 to 523 K (possibly up to 573 K), from 1 to 2000 bar and from 0 to 6 mol kg -1 of NaCl with experimental accuracy. By a more strict theoretical approach and using updated experimental data, this model made substantial improvements over previous models: (1) the accuracy of methane solubility in pure water in the temperature range between 273 and 283 K is increased from about 10% to about 5%, but confirms the accuracy of the Duan model [Duan Z., Moller N., Weare J.H., 1992a. Prediction of methane solubilities in natural waters to high ionic strength from 0 to 250 °C and from 0 to 1600 bar. Geochim. Cosmochim. Acta56, 1451-1460] above 283 K up to 2000 bar; (2) the accuracy of methane solubility in the NaCl aqueous solutions is increased from >12% to about 6% on average from 273 K and 1 bar to 523 K and 2000 bar; (3) this model is able to calculate water content in the gas phase and liquid phase density, which cannot be calculated by previous models; and (4) it covers a wider range of temperature and pressure space. With a simple approach, this model is extended to predict CH 4 solubility in other aqueous salt solutions containing Na +, K +, Mg 2+, Ca 2+, Cl - and SO42-, such as seawater and geothermal brines, with excellent accuracy. This model is also able to calculate homogenization pressure of fluid inclusions (CH 4-H 2O-NaCl) and CH 4 solubility in water at gas-liquid-hydrate phase equilibrium. A computer code is developed for this model and can be downloaded from the website: www.geochem-model.org/programs.htm.

  2. Membrane-Based Characterization of a Gas Component — A Transient Sensor Theory

    PubMed Central

    Lazik, Detlef

    2014-01-01

    Based on a multi-gas solution-diffusion problem for a dense symmetrical membrane this paper presents a transient theory of a planar, membrane-based sensor cell for measuring gas from both initial conditions: dynamic and thermodynamic equilibrium. Using this theory, the ranges for which previously developed, simpler approaches are valid will be discussed; these approaches are of vital interest for membrane-based gas sensor applications. Finally, a new theoretical approach is introduced to identify varying gas components by arranging sensor cell pairs resulting in a concentration independent gas-specific critical time. Literature data for the N2, O2, Ar, CH4, CO2, H2 and C4H10 diffusion coefficients and solubilities for a polydimethylsiloxane membrane were used to simulate gas specific sensor responses. The results demonstrate the influence of (i) the operational mode; (ii) sensor geometry and (iii) gas matrices (air, Ar) on that critical time. Based on the developed theory the case-specific suitable membrane materials can be determined and both operation and design options for these sensors can be optimized for individual applications. The results of mixing experiments for different gases (O2, CO2) in a gas matrix of air confirmed the theoretical predictions. PMID:24608004

  3. Solubility Database

    National Institute of Standards and Technology Data Gateway

    SRD 106 IUPAC-NIST Solubility Database (Web, free access)   These solubilities are compiled from 18 volumes (Click here for List) of the International Union for Pure and Applied Chemistry(IUPAC)-NIST Solubility Data Series. The database includes liquid-liquid, solid-liquid, and gas-liquid systems. Typical solvents and solutes include water, seawater, heavy water, inorganic compounds, and a variety of organic compounds such as hydrocarbons, halogenated hydrocarbons, alcohols, acids, esters and nitrogen compounds. There are over 67,500 solubility measurements and over 1800 references.

  4. The solubility of platinum and gold in NaCl brines at 1.5 kbar, 600 to 800°C: A laser ablation ICP-MS pilot study of synthetic fluid inclusions

    NASA Astrophysics Data System (ADS)

    Hanley, Jacob J.; Pettke, Thomas; Mungall, James E.; Spooner, Edward T. C.

    2005-05-01

    The concentration and distribution of Pt and Au in a fluid-melt system has been investigated by reacting the metals with S-free, single-phase aqueous brines (20, 50, 70 wt% eq. NaCl) ± peraluminous melt at a confining pressure of 1.5 kbar and temperatures of 600 to 800 °C, trapping the fluid in synthetic fluid inclusions (quartz-hosted) and vesicles (silicate melt-hosted), and quantifying the metal content of the trapped fluid and glass by laser ablation ICP-MS. HCl concentration was buffered using the assemblage albite-andalusite-quartz and f was buffered using the assemblage Ni-NiO. Over the range of experimental conditions, measured concentrations of Pt and Au in the brines ( CPtfluid, CAufluid) are on on the order of 1-10 3 ppm. Concentrations of Pt and Au in the melt ( CPtmelt, CAumelt) are ˜35-100 ppb and ˜400-1200 ppb, respectively. Nernst partition coefficients ( DPtfluid/melt, DAufluid/melt) are on the order of 10 2-10 3 and vary as a function of Cmetalfluid (non-Henry's Law behavior). Trapped fluids show a significant range of metal concentrations within populations of inclusions from single experiments (˜ 1 log unit variability for Au; ˜2-3 log unit variability for Pt). Variability in metal concentration within single inclusion groups is attributed to premature brine entrapment (prior to metal-fluid-melt equilibrium being reached); this allows us to make only minimum estimates of metal solubility using metal concentrations from primary inclusions. The data show two trends: (i) maximum and average values of CAufluid and CPtfluid in inclusions decrease ˜2 orders of magnitude as fluid salinity ( m∑Clfluid) increases from ˜4 to 40 molal (20 to 70 wt % eq. NaCl) at a constant temperature; (ii) maximum and average values of CAufluid increase approximately 1 order of magnitude for every 100°C increase temperature at a fixed m∑Clfluid. The observed behavior may be described by the general expression: log⁡(mmetalfluid,T,1.5kbar

  5. Cell or Cell Membrane-Based Drug Delivery Systems

    PubMed Central

    Tan, Songwei; Wu, Tingting; Zhang, Dan; Zhang, Zhiping

    2015-01-01

    Natural cells have been explored as drug carriers for a long period. They have received growing interest as a promising drug delivery system (DDS) until recently along with the development of biology and medical science. The synthetic materials, either organic or inorganic, are found to be with more or less immunogenicity and/or toxicity. The cells and extracellular vesicles (EVs), are endogenous and thought to be much safer and friendlier. Furthermore, in view of their host attributes, they may achieve different biological effects and/or targeting specificity, which can meet the needs of personalized medicine as the next generation of DDS. In this review, we summarized the recent progress in cell or cell membrane-based DDS and their fabrication processes, unique properties and applications, including the whole cells, EVs and cell membrane coated nanoparticles. We expect the continuing development of this cell or cell membrane-based DDS will promote their clinic applications. PMID:26000058

  6. Membrane-based microextraction techniques in analytical chemistry: A review.

    PubMed

    Carasek, Eduardo; Merib, Josias

    2015-06-23

    The use of membrane-based sample preparation techniques in analytical chemistry has gained growing attention from the scientific community since the development of miniaturized sample preparation procedures in the 1990s. The use of membranes makes the microextraction procedures more stable, allowing the determination of analytes in complex and "dirty" samples. This review describes some characteristics of classical membrane-based microextraction techniques (membrane-protected solid-phase microextraction, hollow-fiber liquid-phase microextraction and hollow-fiber renewal liquid membrane) as well as some alternative configurations (thin film and electromembrane extraction) used successfully for the determination of different analytes in a large variety of matrices, some critical points regarding each technique are highlighted.

  7. Experimental investigation of talc solubility in H sub 2 O-MgCl sub 2 -NaCl-HCl fluids in the range 500-700C, 2 kb

    SciTech Connect

    Grabman, K.B.; Popp, R.K. )

    1991-10-01

    The equilibrium solubility of the talc-quartz mineral assemblage in H{sub 2}O-MgCl{sub 2}-NaCl-HCl fluids at 2 kb and temperatures in the range 500-700C has been determined using rapid-quench hydrothermal techniques. At 500C, the concentration of Mg measured in the fluid after quench decreased in a systematic, nonlinear fashion with increasing concentrations of NaCl, from 2.8 m Mg in NaCl-free solutions to 1.5 m in 5.1 m NaCl. In contrast, at 600 and 700C Mg molalities increased with increasing NaCl molalities. At 600C, the concentration of Mg increased from 0.072 to 0.12 m as the concentration of NaCl increased from 0.0 to 6.1 m. At 700C, Mg molality increased from an NaCl-free value of 0.0078 m, to 0.031 m in 6.3 m NaCl. The observed solubilities were compared to concentrations of aqueous species calculated by solving the series of mass-action and mass-balance equations that describe the activities and molalities of the relevant species in the fluid. It is concluded that at 500C, MgCl{sub 2}{sup 0}, MgCl+, and Mg{sup 2+} are the only Mg-species necessary to account for the observed behavior. The calculations suggest that the decrease in Mg results from both the increasing concentrations of Cl{sup {minus}} as NaCl concentration increases, and the changing dielectric properties of the fluid. At 600 and 700C, the presence of Mg-species in addition to MgCl{sub 2}{sup 0}, MgCl{sup +}, and Mg{sup 2+} may be required to describe the increased solubility observed in the experiments. Use of the slope-quantification method for identifying aqueous species indicates that higher order Mg-Cl species or Na-Mg-Cl species are possible, but the precision of the technique is not sufficient to uniquely identify the species.

  8. Gallium nitride electrodes for membrane-based electrochemical biosensors

    NASA Astrophysics Data System (ADS)

    Schubert, T.; Steinhoff, G.; von Ribbeck, H.-G.; Stutzmannn, M.; Eickhoff, M.; Tanaka, M.

    2009-10-01

    We report on the deposition of planar lipid bilayers (supported membranes) on gallium nitride (GaN) electrodes for potential applications as membrane-based biosensors. The kinetics of the lipid membrane formation upon vesicle fusion were monitored by simultaneous measurements of resistance and capacitance of the membrane using AC impedance spectroscopy in the frequency range between 50mHz and 50kHz. We could identify a two-step process of membrane spreading and self-healing. Despite its relatively low resistance, the membrane can be modeled by a parallel combination of an ideal resistor and capacitor, indicating that the membrane efficiently blocks the diffusion of ions.

  9. Membrane-based processes for sustainable power generation using water.

    PubMed

    Logan, Bruce E; Elimelech, Menachem

    2012-08-16

    Water has always been crucial to combustion and hydroelectric processes, but it could become the source of power in membrane-based systems that capture energy from natural and waste waters. Two processes are emerging as sustainable methods for capturing energy from sea water: pressure-retarded osmosis and reverse electrodialysis. These processes can also capture energy from waste heat by generating artificial salinity gradients using synthetic solutions, such as thermolytic salts. A further source of energy comes from organic matter in waste waters, which can be harnessed using microbial fuel-cell technology, allowing both wastewater treatment and power production.

  10. Gallium nitride electrodes for membrane-based electrochemical biosensors.

    PubMed

    Schubert, T; Steinhoff, G; von Ribbeck, H-G; Stutzmannn, M; Eickhoff, M; Tanaka, M

    2009-10-01

    We report on the deposition of planar lipid bilayers (supported membranes) on gallium nitride (GaN) electrodes for potential applications as membrane-based biosensors. The kinetics of the lipid membrane formation upon vesicle fusion were monitored by simultaneous measurements of resistance and capacitance of the membrane using AC impedance spectroscopy in the frequency range between 50 mHz and 50 kHz. We could identify a two-step process of membrane spreading and self-healing. Despite its relatively low resistance, the membrane can be modeled by a parallel combination of an ideal resistor and capacitor, indicating that the membrane efficiently blocks the diffusion of ions.

  11. Preparation of olanzapine and methyl-β-cyclodextrin complexes using a single-step, organic solvent-free supercritical fluid process: An approach to enhance the solubility and dissolution properties.

    PubMed

    Rudrangi, Shashi Ravi Suman; Trivedi, Vivek; Mitchell, John C; Wicks, Stephen Richard; Alexander, Bruce David

    2015-10-15

    The purpose of this study was to evaluate a single-step, organic solvent-free supercritical fluid process for the preparation of olanzapine-methyl-β-cyclodextrin complexes with an express goal to enhance the dissolution properties of olanzapine. The complexes were prepared by supercritical carbon dioxide processing, co-evaporation, freeze drying and physical mixing. The prepared complexes were then analysed by differential scanning calorimetry, X-ray powder diffraction, scanning electron microscopy, solubility and dissolution studies. Computational molecular docking studies were performed to study the formation of molecular inclusion complexation of olanzapine with methyl-β-cyclodextrin. All the binary mixtures of olanzapine with methyl-β-cyclodextrin, except physical mixture, exhibited a faster and greater extent of drug dissolution than the drug alone. Products obtained by the supercritical carbon dioxide processing method exhibited the highest apparent drug dissolution. The characterisation by different analytical techniques suggests complete complexation or amorphisation of olanzapine and methyl-β-cyclodextrin complexes prepared by supercritical carbon dioxide processing method. Therefore, organic solvent-free supercritical carbon dioxide processing method proved to be novel and efficient for the preparation of solid inclusion complexes of olanzapine with methyl-β-cyclodextrin. The preliminary data also suggests that the complexes of olanzapine with methyl-β-cyclodextrin will lead to better therapeutic efficacy due to better solubility and dissolution properties.

  12. Membrane-Based Water Evaporator for a Space Suit

    NASA Technical Reports Server (NTRS)

    Ungar, Eugene K.; McCann, Charles J.; O'Connell, Mary K.; Andrea, Scott

    2004-01-01

    A membrane-based water evaporator has been developed that is intended to serve as a heat-rejection device for a space suit. This evaporator would replace the current sublimator that is sensitive to contamination of its feedwater. The design of the membrane-based evaporator takes advantage of recent advances in hydrophobic micropore membranes to provide robust heat rejection with much less sensitivity to contamination. The low contamination sensitivity allows use of the heat transport loop as feedwater, eliminating the need for the separate feedwater system used for the sublimator. A cross section of the evaporator is shown in the accompanying figure. The space-suit cooling loop water flows into a distribution plenum, through a narrow annulus lined on both sides with a hydrophobic membrane, into an exit plenum, and returns to the space suit. Two perforated metal tubes encase the membranes and provide structural strength. Evaporation at the membrane inner surface dissipates the waste heat from the space suit. The water vapor passes through the membrane, into a steam duct and is vented to the vacuum environment through a back-pressure valve. The back-pressure setting can be adjusted to regulate the heat-rejection rate and the water outlet temperature.

  13. Rare earth element enrichment using membrane based solvent extraction

    NASA Astrophysics Data System (ADS)

    Makertiharta, I. G. B. N.; Dharmawijaya, P. T.; Zunita, M.; Wenten, I. G.

    2017-01-01

    The chemical, catalytic, electrical, magnetic, and optical properties of rare earth elements are required in broad applications. Rare earth elements have similar physical and chemical properties thus it is difficult to separate one from each other. Rare earth element is relatively abundant in earth's crust but rarely occur in high concentrated deposits. Traditionally, ion-exchange and solvent extraction techniques have been developed to separate and purify single rare earth solutions or compounds. Recently, membrane starts to gain attention for rare earth separation by combining membrane and proven technologies such as solvent extraction. Membrane-based process offers selective, reliable, energy efficient and easy to scale up separation. During membrane-based separation process, one phase passes through membrane pores while the other phase is rejected. There is no direct mixing of two phases thus the solvent loss is very low. Membrane can also lower solvent physical properties requirement (viscosity, density) and backmixing, eliminate flooding phenomenon and provide large interfacial area for mass transfer. This paper will summarize research efforts in developing membrane technology for rare earth element separation. Special attention will be given to solvent extraction related process as the commonly used method for rare earth element separation. Furthermore, membrane configuration and its potentials will also be discussed.

  14. Soluble surfactants favorably modify fluid structure and wall shear stress profiles during near-occluding bubble motion in a computational model of intravascular gas embolism

    NASA Astrophysics Data System (ADS)

    Swaminathan, T. N.; Ayyaswamy, P. S.; Eckmann, D. M.

    2009-11-01

    Finite sized gas bubble motion in a blood vessel causes temporal and spatial gradients of shear stress at the endothelial cell surface lining the vessel wall as the bubble approaches the cell, moves over it and passes it by. Rapid reversals occur in the sign of the shear stress imparted to the cell surface during this motion. The sign-reversing shear is a potently coupled source of cell surface mechanical stretch, potentiating cell injury. The presence of a suitable soluble surfactant in the bulk medium considerably reduces the level of the shear stress gradients imparted to the cell surface as compared to an equivalent surfactant-free system. The bubble shape and the film thickness between the bubble and the vessel wall are also different. Furthermore, the bubble residence time near the proximity of a cell surface changes in comparison. These results based on our modeling may help explain several phenomena observed in experimental studies related to gas embolism, a significant problem in cardiac surgery and decompression sickness.

  15. [Membrane-based photochemical systems as models for photosynthetic cells

    SciTech Connect

    Hurst, J.K.

    1992-01-01

    The objectives of this research are to improve our conceptual view of the ways in which membranes and interfaces can be used to control chemical reactivity. We have focused on understanding three elementary processes that are central to developing membrane-based integrated chemical systems for water photolysis or related photoconversion/photostorage processes. Specifically, we have sought to identify: the influence of interfaces upon charge separation/recombination reactions, pathways for transmembrane charge separation across hydrocarbon bilayer membranes, and mechanisms of water oxidation catalyzed by transition metal coordination complexes. Historically, the chemical dynamics of each of these processes has been poorly understood, with numerous unresolved issues and conflicting viewpoints appearing in the literature. As described in this report our recent research has led to considerable clarification of the underlying reaction mechanisms.

  16. Development of polymer-membrane based electrodes for suramin.

    PubMed

    Yu, Andrew; Shepherd, Brandon; Wagner, Meghan; Clapper, Jamie; Esson, Joan M

    2011-02-07

    The development of a polymer membrane-based electrode to measure the anionic drug suramin in buffered saline and biological samples is described. A large non-equilibrium, steady state EMF response is observed toward suramin, and judicious choice of the polymer membrane components allows for adjustment of the dynamic range of the electrode. The optimized membrane for use in the toxic suramin range consists of 25 wt% tridodecylmethyl ammonium chloride, 55 wt% bis-2-ethylhexyl sebacate, and 20 wt% Pellethane. Although this electrode can be used to directly quantify suramin in human plasma, determination of suramin that is not affected by the background concentration of small anions is best achieved by simple potentiometric titrations with polycationic protamine monitored with a protamine-sensitive electrode.

  17. Osmosensing by Bacteria: Signals and Membrane-Based Sensors

    PubMed Central

    Wood, Janet M.

    1999-01-01

    Bacteria can survive dramatic osmotic shifts. Osmoregulatory responses mitigate the passive adjustments in cell structure and the growth inhibition that may ensue. The levels of certain cytoplasmic solutes rise and fall in response to increases and decreases, respectively, in extracellular osmolality. Certain organic compounds are favored over ions as osmoregulatory solutes, although K+ fluxes are intrinsic to the osmoregulatory response for at least some organisms. Osmosensors must undergo transitions between “off” and “on” conformations in response to changes in extracellular water activity (direct osmosensing) or resulting changes in cell structure (indirect osmosensing). Those located in the cytoplasmic membranes and nucleoids of bacteria are positioned for indirect osmosensing. Cytoplasmic membrane-based osmosensors may detect changes in the periplasmic and/or cytoplasmic solvent by experiencing changes in preferential interactions with particular solvent constituents, cosolvent-induced hydration changes, and/or macromolecular crowding. Alternatively, the membrane may act as an antenna and osmosensors may detect changes in membrane structure. Cosolvents may modulate intrinsic biomembrane strain and/or topologically closed membrane systems may experience changes in mechanical strain in response to imposed osmotic shifts. The osmosensory mechanisms controlling membrane-based K+ transporters, transcriptional regulators, osmoprotectant transporters, and mechanosensitive channels intrinsic to the cytoplasmic membrane of Escherichia coli are under intensive investigation. The osmoprotectant transporter ProP and channel MscL act as osmosensors after purification and reconstitution in proteoliposomes. Evidence that sensor kinase KdpD receives multiple sensory inputs is consistent with the effects of K+ fluxes on nucleoid structure, cellular energetics, cytoplasmic ionic strength, and ion composition as well as on cytoplasmic osmolality. Thus, osmoregulatory

  18. Membrane-based systems for carbon capture and hydrogen purification

    SciTech Connect

    Berchtold, Kathryn A

    2010-11-24

    This presentation describes the activities being conducted at Los Alamos National Laboratory to develop carbon capture technologies for power systems. This work is aimed at continued development and demonstration of a membrane based pre- and post-combustion carbon capture technology and separation schemes. Our primary work entails the development and demonstration of an innovative membrane technology for pre-combustion capture of carbon dioxide that operates over a broad range of conditions relevant to the power industry while meeting the US DOE's Carbon Sequestration Program goals of 90% CO{sub 2} capture at less than a 10% increase in the cost of energy services. Separating and capturing carbon dioxide from mixed gas streams is a first and critical step in carbon sequestration. To be technically and economically viable, a successful separation method must be applicable to industrially relevant gas streams at realistic temperatures and pressures as well as be compatible with large gas volumes. Our project team is developing polymer membranes based on polybenzimidazole (PBI) chemistries that can purify hydrogen and capture CO{sub 2} at industrially relevant temperatures. Our primary objectives are to develop and demonstrate polymer-based membrane chemistries, structures, deployment platforms, and sealing technologies that achieve the critical combination of high selectivity, high permeability, chemical stability, and mechanical stability all at elevated temperatures (> 150 C) and packaged in a scalable, economically viable, high area density system amenable to incorporation into an advanced Integrated Gasification Combined-Cycle (IGCC) plant for pre-combustion CO{sub 2} capture. Stability requirements are focused on tolerance to the primary synthesis gas components and impurities at various locations in the IGCC process. Since the process stream compositions and conditions (temperature and pressure) vary throughout the IGCC process, the project is focused on the

  19. Evolution of strategies to achieve baseline separation of ten anionic, water-soluble sulfated estrogens via achiral packed column supercritical fluid chromatography.

    PubMed

    Patel, M A; Hardink, M A; Wrisely, L; Riley, F W; Hudalla, C J; Ashraf-Khorassani, M; Taylor, L T

    2014-11-28

    Near baseline separation of ten sulfated sodium salts of various structurally related estrogens employing a variety of bonded stationary phase packed columns was obtained using a conventional supercritical fluid chromatograph coupled with UV detection. Critical pairs 2/3 (8,9-dehydroestrone/17β-dihydroequilin) and 6/7 (17α-estradiol or 17α-dihydroequilin/estrone), however, failed to baseline separate. In all preliminary separations, 10mM ammonium acetate and variable percentages of H2O were initially used as co-additives in conjunction with methanol as a modifier. Different modifier programs and temperatures were employed to optimize the separation in a timely manner. A 2-ethylpyridine column provided the best separation compared to bare silica, diol, and cyano-based bonded phase columns. The employment of both salt and water as additives to the methanol-modified CO2 mobile phase suggested a mixed mode separation mechanism involving both ion pairing of each anionic sulfated estrogen with ammonium ion and hydrophilic interaction facilitated by partitioning of analyte between the aqueous solvated stationary phase and the aqueous component of the mobile phase. Upon more extensive study with either iso-propylamine or formic acid-ammonium formate buffer, the critical anionic pairs were 95% baseline resolved.

  20. High Levels of Soluble C5b-9 Complex in Dialysis Fluid May Predict Poor Prognosis in Peritonitis in Peritoneal Dialysis Patients

    PubMed Central

    Mizuno, Masashi; Suzuki, Yasuhiro; Higashide, Keiko; Sei, Yumi; Iguchi, Daiki; Sakata, Fumiko; Horie, Masanobu; Maruyama, Shoichi; Matsuo, Seiichi; Morgan, B. Paul; Ito, Yasuhiko

    2017-01-01

    Background We searched for indicators to predict the prognosis of infectious peritonitis by measuring levels of complement proteins and activation products in peritoneal dialysis (PD) fluid (PDF) of patients at early stages of peritonitis. We retrospectively analyzed the relationship between the levels of sC5b-9, C3 and C4 in PDF and the subsequent clinical prognosis. Methods We measured levels of sC5b-9, C3 and C4 in PDF on days 1, 2 and 5 post-onset of peritonitis in 104 episodes of infectious peritonitis in PD patients from 2008 and retrospectively compared levels with clinical outcomes. Further analysis for the presence of causative microorganisms or to demonstrate bacterial culture negative peritonitis was performed and correlated with change of levels of sC5b-9 in PDF. Results When PD patients with peritonitis were divided into groups that either failed to recover from peritonitis and were finally withdrawn from PD (group 1; n = 25) or recovered (group 2; n = 79), levels of sC5b-9, C3 and C4 in PDF were significantly higher in group 1 patients compared to those in group 2 on day5. Analysis of microorganisms showed significantly higher sC5b-9 levels in PDF of peritonitis cases caused by culture negative peritonitis in group 1 compared with group 2 when we analyzed for individual microorganisms. Of note, on day5, the sC5b-9 levels in PDF were similarly high in peritonitis caused by fungi or other organisms. Conclusion Our results suggested that levels of complement markers in PDF, especially sC5b-9, have potential as surrogate markers to predict prognosis of PD-related peritonitis. PMID:28046064

  1. Anhydrite Solubility and Ca Isotope Fractionation in the Vapor-Liquid Field of the NaCl-H2O System: Implications for Hydrothermal Vent Fluids at Mid-ocean Ridges

    NASA Astrophysics Data System (ADS)

    Scheuermann, P.; Syverson, D. D.; Higgins, J. A.; Seyfried, W. E., Jr.

    2015-12-01

    Hydrothermal experiments were performed at 410, 420 and 450°C between 180-450 bar to investigate anhydrite (CaSO4) solubility and Ca isotope fractionation in the liquid-vapor stability field of the NaCl-H2O system. Experiments were conducted in flexible gold reaction cells and a fixed volume Ti reactor to reach all pressures between the critical curve and three-phase boundary. During isothermal decompression at 410°C, anhydrite solubility in the liquid phase increases (1 to 9 mmol/kg Ca), whereas the solubility decreases in the vapor phase (130 to < 10 umol/kg Ca). At 410°C and 290-270 bar, the partition coefficient, log Km = log (mv / ml), for Ca decreases from -1.35 to -2.46, and that of SO4 decreases from -1.76 to -2.82. At 420°C the Ca:SO4 ratio of the starting solution was 2:1, and the pH25°C decreases in the liquid and increases in the vapor upon decompression. Ca hydrolysis in the liquid and complex interactions between undetermined aqueous species in the vapor could explain this pattern. At 410 and 450°C, the experiments started with a Ca:SO4 ratio of 1:1. Along the 410°C isotherm, pH25°C initially increases in both the liquid and vapor, potentially caused by precipitation of an H+ bearing salt, such as NaHSO4. 30-40 bar below the critical curve there is a sudden decrease in pH25°C as the putative salt phase may become unstable and dissolve. At 450°C, pH25°C decreases in the vapor and increases in the liquid, as HCl and H2SO4 partition into the vapor. Ca isotope data at 420°C between 375-300 bar indicate that the vapor is isotopically light relative to the liquid. At lower pressures both phases approach the isotopic composition of the coexisting anhydrite, suggesting that dissolved Ca speciation becomes more structurally similar to anhydrite. This study furthers our understanding of elemental partitioning and isotopic fractionation in mineral-fluid systems with implications for mass transfer reactions at/near the magma-hydrothermal boundary at

  2. Interaction of vitamin D with membrane-based signaling pathways

    PubMed Central

    Larriba, María Jesús; González-Sancho, José Manuel; Bonilla, Félix; Muñoz, Alberto

    2014-01-01

    Many studies in different biological systems have revealed that 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) modulates signaling pathways triggered at the plasma membrane by agents such as Wnt, transforming growth factor (TGF)-β, epidermal growth factor (EGF), and others. In addition, 1α,25(OH)2D3 may affect gene expression by paracrine mechanisms that involve the regulation of cytokine or growth factor secretion by neighboring cells. Moreover, post-transcriptional and post-translational effects of 1α,25(OH)2D3 add to or overlap with its classical modulation of gene transcription rate. Together, these findings show that vitamin D receptor (VDR) cannot be considered only as a nuclear-acting, ligand-modulated transcription factor that binds to and controls the transcription of target genes. Instead, available data support the view that much of the complex biological activity of 1α,25(OH)2D3 resides in its capacity to interact with membrane-based signaling pathways and to modulate the expression and secretion of paracrine factors. Therefore, we propose that future research in the vitamin D field should focus on the interplay between 1α,25(OH)2D3 and agents that act at the plasma membrane, and on the analysis of intercellular communication. Global analyses such as RNA-Seq, transcriptomic arrays, and genome-wide ChIP are expected to dissect the interactions at the gene and molecular levels. PMID:24600406

  3. Experimental determination of quartz solubility and melting in the system SiO2-H2O-NaCl at 15-20 kbar and 900-1100 °C: implications for silica polymerization and the formation of supercritical fluids

    NASA Astrophysics Data System (ADS)

    Cruz, Miguel F.; Manning, Craig E.

    2015-10-01

    We investigated quartz solubility and melting in the system SiO2-NaCl-H2O at 15-20 kbar and 900-1100 °C using hydrothermal piston-cylinder methods. The solubility of natural, high-purity quartz was determined by weight loss. Quartz solubility decreases with increasing NaCl mole fraction ( X NaCl) at fixed pressure and temperature. The decline is greatest at low X NaCl. The solubility patterns can be explained by changes in the concentration and identity of silica oligomers. Modeling of results at 1000 °C, 15 kbar, reveals that silica monomers and dimers predominate at low Si concentration (high X NaCl), that higher oligomers assumed to be trimers become detectable at X NaCl = 0.23, and that the trimers contain >50 % of dissolved Si at X NaCl = 0. The modeling further implies a hydration number for the silica monomer of 1.6, significantly lower than is observed in previous studies. Results at 15 kbar and 1100 °C provide evidence of two coexisting fluid phases. Although solubility could not be determined directly in these cases, the presence or absence of phases over a range of bulk compositions permitted mapping of the topology of the phase diagram. At 1100 °C, 15 kbar, addition of only a small amount of NaCl ( X NaCl = 0.05) leads to separation of two fluid phases, one rich in H2O and SiO2, the other rich in NaCl with lower SiO2. Textural identification of two fluids is supported by very low quench pH due to preferential partitioning of Na into the fluid that is rich in SiO2 and H2O, confirmed by electron microprobe analyses. The addition of NaCl causes the upper critical end point on the SiO2-H2O melting curve to migrate to significantly higher pressure. Correspondence between depolymerization and phase separation of SiO2-H2O-NaCl fluids indicates that polymerization plays a fundamental role in producing critical mixing behavior in silicate-fluid systems.

  4. Soluble vs. insoluble fiber

    MedlinePlus

    ... soluble and insoluble. Both are important for health, digestion, and preventing diseases. Soluble fiber attracts water and turns to gel during digestion. This slows digestion. Soluble fiber is found in ...

  5. Amorphous solid dispersion enhances permeation of poorly soluble ABT-102: true supersaturation vs. apparent solubility enhancement.

    PubMed

    Frank, Kerstin J; Rosenblatt, Karin M; Westedt, Ulrich; Hölig, Peter; Rosenberg, Jörg; Mägerlein, Markus; Fricker, Gert; Brandl, Martin

    2012-11-01

    Amorphous solid dispersions (ASDs) represent a promising formulation approach for poorly soluble drugs. We explored the formulation-related impact of ASDs on permeation rate, apparent solubility and molecular solubility of the poorly soluble drug ABT-102. The influence of fasted state simulated intestinal fluid (FaSSIF) as dispersion medium was also studied. ASDs were prepared by hot-melt extrusion. Permeation rate was assessed by the Caco-2 transwell assay. Cell viability and barrier integrity were assured by AlamarBlue©, TEER and permeability of the hydrophilic marker carboxyfluorescein. Apparent solubility and molecular solubility were evaluated by using centrifugation and inverse dialysis, respectively. The in vitro permeation rate of ABT-102 from aqueous dispersions of the ASD was found 4 times faster than that from the dispersions of the crystals, while apparent solubility and molecular solubility of ABT-102 were increased. Yet, a further increase in apparent solubility due to micellar solubilization as observed when dispersing the ASD in FaSSIF, did not affect molecular solubility or permeation rate. Overall, a good correlation between permeation rate and molecular solubility but not apparent solubility was seen.

  6. Fluid imbalance

    MedlinePlus

    ... up in the body. This is called fluid overload (volume overload). This can lead to edema (excess fluid in ... Water imbalance; Fluid imbalance - dehydration; Fluid buildup; Fluid overload; Volume overload; Loss of fluids; Edema - fluid imbalance; ...

  7. System and method for air temperature control in an oxygen transport membrane based reactor

    DOEpatents

    Kelly, Sean M

    2016-09-27

    A system and method for air temperature control in an oxygen transport membrane based reactor is provided. The system and method involves introducing a specific quantity of cooling air or trim air in between stages in a multistage oxygen transport membrane based reactor or furnace to maintain generally consistent surface temperatures of the oxygen transport membrane elements and associated reactors. The associated reactors may include reforming reactors, boilers or process gas heaters.

  8. System and method for temperature control in an oxygen transport membrane based reactor

    DOEpatents

    Kelly, Sean M.

    2017-02-21

    A system and method for temperature control in an oxygen transport membrane based reactor is provided. The system and method involves introducing a specific quantity of cooling air or trim air in between stages in a multistage oxygen transport membrane based reactor or furnace to maintain generally consistent surface temperatures of the oxygen transport membrane elements and associated reactors. The associated reactors may include reforming reactors, boilers or process gas heaters.

  9. Membrane-Based Functions in the Origin of Cellular Life

    NASA Technical Reports Server (NTRS)

    Wilson, Michael A.

    2003-01-01

    How simple membrane peptides performed such essential proto-cellular functions as transport of ions and organic matter across membranes separating the interior of the cell from the environment, capture and utilization of energy, and transduction of environmental signals, is a key question in protobiological evolution. On the basis of detailed, molecular-level computer simulations we investigate how these peptides insert into membranes, self-assemble into higher-order structures and acquire functions. We have studied the insertion of an a-helical peptide containing leucine (L) and serine (S) of the form (LSLLLSL)S into a model membrane. The transmembrane state is metastable, and approximately 15 kcal/mol is required to insert the peptide into the membrane. Investigations of dimers formed by (LSLLLSL)S and glycophorin A demonstrate how the favorable free energy of helix association can offset the unfavorable free energy of insertion, leading to self- assembly of peptide helices in the membrane. An example of a self-assembled structure is the tetrameric transmembrane pore of the influenza virus M2 protein, which is an efficient and selective voltage-gated proton channel. Our simulations explain the gating mechanism and provide guidelines how to reengineering the channel to act as a simple proton pump. In general, emergence of integral membrane proteins appears to be quite feasible and may be easier to envision than the emergence of water-soluble proteins.

  10. Experimental determination of synthetic NdPO4 monazite end-member solubility in water from 21°C to 300°C: implications for rare earth element mobility in crustal fluids1 1Associate editor: D. J. Wesolowski

    NASA Astrophysics Data System (ADS)

    Poitrasson, Franck; Oelkers, Eric; Schott, Jacques; Montel, Jean-Marc

    2004-05-01

    The solubility of synthetic NdPO 4 monazite end-member has been determined experimentally from 21 to 300°C in aqueous solutions at pH = 2, and at 21°C and pH = 2 for GdPO 4. Measurements were performed in batch reactors, with regular solution sampling for pH measurement, rare earths and phosphorous analysis by inductively coupled plasma mass spectrometry (ICP-MS) coupled with a desolvation system. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were employed to check that no reprecipitation of secondary phases occurred and that the mineral surfaces remained those of a monazite. Coupled with speciation calculations, measured solution compositions permitted the determination of NdPO 4 and GdPO 4 solubility products which are in general agreement with previous experimental determination on rhabdophane at 25°C, but showing that monazite is more than two orders of magnitude less soluble than inferred on the basis of previous thermodynamic estimates. The temperature evolution from 21 to 300°C of the equilibrium constant (K) of the NdPO 4 monazite end-member dissolution reaction given by: NdPO4( s) ⇆ Nd3++ PO43- can be described by the equation: -log K= 7.621+ 0.04163T+ 1785/T where T is in Kelvins. Integration of this expression permitted the determination of the enthalpy, free energy and entropy of dissolution and formation of the NdPO 4 monazite end-member. Solubility-speciation calculations show that the presence of aqueous ligands, notably fluoride, carbonate or hydroxide in water strongly affect monazite solubility, depending on pH and temperature. These calculations also show that monazite will exhibit retrograde solubility only under acidic conditions from 70°C to 300°C and to a lesser extent in neutral aqueous solutions from 150°C to 300°C. Solubility-speciation calculations performed on natural seafloor vent hydrothermal fluids and on thermal springwaters from granitic areas at aquifer temperature show that these fluids

  11. A smart membrane based on an antigen-responsive hydrogel.

    PubMed

    Zhang, Rongsheng; Bowyer, Adrian; Eisenthal, Robert; Hubble, John

    2007-07-01

    Hydrogel membranes have been fabricated that incorporate antibody/antigen moieties. The permeability of large solutes through these membranes is dependent on the presence of soluble antigen that can compete with the internal interactions between antibody and antigen leading to an increase in gel mesh size. Specifically, the membrane's structure is based on a dextran backbone grafted with a fluorescein isothiocyanate (FITC) antigen and a sheep anti-FITC IgG antibody. The backbone is covalently cross-linked by conjugated divinyl sulfone (DVS) groups. The gel structure is additionally stabilized by affinity crosslinks formed by biospecific interactions between the bound IgG and FITC. FTIR spectra of the gel are consistent with formation of covalent bonds between cysteine groups in the IgG and DVS groups in the dextran. Results obtained using isothermal titration calorimetry (ITC) confirmed the competitive interaction binding between IgG-FITC-dextran and free sodium fluorescein at pH 5.0. Scanning electron microscopy (SEM) of samples prepared using cryofixation and cryofracturing techniques showed that observed changes in permeability correlate with free fluorescein-dependent structural changes in the gel. Three-dimensional images obtained from confocal laser scanning microscopy show that these changes occur throughout the gel and indicate that SEM results are not artifacts of sample preparation. The permeability of these gels, as shown by blue-dextran (12 kDa) diffusion, increases in response to the presence of free fluorescein of the external medium, which causes competitive displacement of the affinity cross-links. Sequential addition and removal of sodium fluorescein showed that these permeability changes are reversible.

  12. Fluid extraction

    DOEpatents

    Wai, Chien M.; Laintz, Kenneth E.

    1999-01-01

    A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated .beta.-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated .beta.-diketone and a trialkyl phosphate, or a fluorinated .beta.-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated .beta.-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The method is particularly useful for extracting actinides and lanthanides from acidic solutions. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

  13. The Solubility of Oxygen and Ozone in Liquids

    NASA Astrophysics Data System (ADS)

    Battino, Rubin; Rettich, Timothy R.; Tominaga, Toshihiro

    1983-04-01

    This review covers the solubility of oxygen and ozone in liquids as a function of temperature and pressure. Solubility data for individual systems were critically evaluated and recommended or tentative values presented in many cases. The trend of solubilities in homologous series or related solvents is discussed. Liquids include water; seawater; aqueous salt solutions; mixed solvents; hydrocarbons; organic compounds containing oxygen, halogen, sulfur, nitrogen, or silicon; olive oil; and human blood. For ozone, only its solubility in water is presented. Key words: aqueous solutions; biological fluids; gas solubility; hydrocarbons; mixed solvents; organic solvents; oxygen; ozone; seawater; water.

  14. Recent developments in membrane-based separations in biotechnology processes: review.

    PubMed

    Rathore, A S; Shirke, A

    2011-01-01

    Membrane-based separations are the most ubiquitous unit operations in biotech processes. There are several key reasons for this. First, they can be used with a large variety of applications including clarification, concentration, buffer exchange, purification, and sterilization. Second, they are available in a variety of formats, such as depth filtration, ultrafiltration, diafiltration, nanofiltration, reverse osmosis, and microfiltration. Third, they are simple to operate and are generally robust toward normal variations in feed material and operating parameters. Fourth, membrane-based separations typically require lower capital cost when compared to other processing options. As a result of these advantages, a typical biotech process has anywhere from 10 to 20 membrane-based separation steps. In this article we review the major developments that have occurred on this topic with a focus on developments in the last 5 years.

  15. Oxygen transport membrane based advanced power cycle with low pressure synthesis gas slip stream

    DOEpatents

    Kromer, Brian R.; Litwin, Michael M.; Kelly, Sean M.

    2016-09-27

    A method and system for generating electrical power in which a high pressure synthesis gas stream generated in a gasifier is partially oxidized in an oxygen transport membrane based reactor, expanded and thereafter, is combusted in an oxygen transport membrane based boiler. A low pressure synthesis gas slip stream is split off downstream of the expanders and used as the source of fuel in the oxygen transport membrane based partial oxidation reactors to allow the oxygen transport membrane to operate at low fuel pressures with high fuel utilization. The combustion within the boiler generates heat to raise steam to in turn generate electricity by a generator coupled to a steam turbine. The resultant flue gas can be purified to produce a carbon dioxide product.

  16. Supercritical fluid extraction

    DOEpatents

    Wai, Chien M.; Laintz, Kenneth

    1994-01-01

    A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated or lipophilic crown ether or fluorinated dithiocarbamate. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.

  17. MEMBRANE TECHNOLOGY: OPPORTUNITIES FOR POLYHEDRAL OLIGOMERIC SILSESQUIOXANES (POSS) IN MEMBRANE-BASED SEPARATIONS

    EPA Science Inventory

    Membrane Technology: Opportunities for Polyhedral Oligomeric Silsesquioxanes (POSS?) in Membrane-Based Separations

    Leland M. Vane, Ph.D.
    U.S. Environmental Protection Agency
    Office of Research & Development
    Cincinnati, OH 45268
    Vane.Leland@epa.gov

    A sign...

  18. Amyloid Fibril Solubility.

    PubMed

    Rizzi, L G; Auer, S

    2015-11-19

    It is well established that amyloid fibril solubility is protein specific, but how solubility depends on the interactions between the fibril building blocks is not clear. Here we use a simple protein model and perform Monte Carlo simulations to directly measure the solubility of amyloid fibrils as a function of the interaction between the fibril building blocks. Our simulations confirms that the fibril solubility depends on the fibril thickness and that the relationship between the interactions and the solubility can be described by a simple analytical formula. The results presented in this study reveal general rules how side-chain-side-chain interactions, backbone hydrogen bonding, and temperature affect amyloid fibril solubility, which might prove to be a powerful tool to design protein fibrils with desired solubility and aggregation properties in general.

  19. Efficient long-term and high-yielded production of a recombinant proteoglycan in eukaryotic HEK293 cells using a membrane-based bioreactor.

    PubMed

    Adam, Estelle; Sarrazin, Stéphane; Landolfi, Cindy; Motte, Vincent; Lortat-Jacob, Hugues; Lassalle, Philippe; Delehedde, Maryse

    2008-05-02

    Standard culture systems of eukaryotic cells generally failed to deliver sufficient amounts of recombinant proteins without increasing the costs of production. We here showed that membrane-based bioreactors, initially developed for the production of monoclonal antibodies, can be very useful for the production using engineered HEK293 cells, of a recombinant proteoglycan called endocan, with achievement of high level expression and efficient long-term production. When compared to standard procedures, the growth in suspension and at high density of these cells in one bioreactor promoted a 60-fold increase of the concentration of the soluble recombinant endocan. These culture conditions did not affect cell viability, stable expression, recognition by specific monoclonal antibodies or electrophoretic profile of the recombinant endocan. Such an easy to scale up system to produce recombinant protein should open soon new opportunities to study structure and functions of endocan or any other glycosylated cell products newly investigated.

  20. Mass spectrometry with direct supercritical fluid injection

    SciTech Connect

    Smith, R.D.; Udseth, H.R.

    1983-12-01

    Direct fluid injection mass spectrometry utilizes supercritical fluids for solvation and transfer of materials to a mass spectrometer chemical ionization (CI) source. Available data suggest that any material soluble in a supercritical fluid is transferred efficiently to the ionization region. Mass spectra are presented for mycotoxins of the trichothecene group obtained by use of supercritical carbon dioxide with isobutane as the CI reagent gas. Direct fluid injection MS/MS is also illustrated for major ions in the isobutane chemical ionization of T-2 toxin. The effect of pressure and temperature upon solubility in supercritical fluids is described and illustrated for diacetoxycirpenol. A potential method is also demonstrated for on-line fraction during MS analysis using pressure to control supercritical fluid solubility. Mass spectra are also presented for polar compounds, using supercritical ammonia, and the extension to complex mixtures is described. The fundamental basis and experimental requirements of the direct fluid injection process are discussed. 34 references, 11 figures, 1 table.

  1. Mass spectrometry with direct supercritical fluid injection

    SciTech Connect

    Smith, R.D.; Udseth, H.R.

    1983-12-01

    Direct fluid injection mass spectrometry utilizes supercritical fluids for solvation and transfer of materials to a mass spectrometer chemical ionization (CI) source. Available data suggest that any material soluble in a supercritical fluid is transferred efficiently to the ionization region. Mass spectra are presented for mycotoxins of the trichothecene group obtained by use of supercritical carbon dioxide with isobutane as the CI reagent gas. Direct fluid injection MS/MS is also illustrated for major ions in the isobutane chemical ionization of T-2 toxin. The effect of pressure and temperature upon solubility in supercritical fluids is described and illustrated for diacetoxyscirpenol. A potential method is also demonstrated for ''on-line fractionation'' during MS analysis using pressure to control supercritical fluid solubility. Mass spectra are also presented for polar compounds, using supercritical ammonia, and the extension to complex mixtures is described. The fundamental basis and experimental requirements of the direct fluid injection process are discussed. 1 figure, 11 tables.

  2. Biorelevant solubility of poorly soluble drugs: rivaroxaban, furosemide, papaverine and niflumic acid.

    PubMed

    Takács-Novák, Krisztina; Szőke, Vera; Völgyi, Gergely; Horváth, Péter; Ambrus, Rita; Szabó-Révész, Piroska

    2013-09-01

    In this work the biorelevant solubility of four drugs representing different acid-base property, wide range of lipohilicity and low aqueous solubility was studied. The equilibrium solubility of rivaroxaban (non-ionizable), furosemide (acid), papaverine (base) and niflumic acid (ampholyte) was determined in simulated gastric fluid (SGF pH 1.2), in simulated intestinal fluid fasted state (FaSSIF pH 6.5) and fed state (FeSSIF pH 5.0) and their corresponding blank buffers at a temperature of 37 °C using saturation shake-flask method. The concentration was measured by optimized HPLC analysis. The solubilizing effect of bile acid/lipid micelles as additive components of biorelevent media (BRM) is expressed with the solubility ratio (SR: SBRM/Sblank buffer) and the food effect was estimated from SFeSSIF/SFaSSIF coefficient. It was revealed that ionization plays primarily role in solubility of compounds which undergo ionization in BRM. The solubilizing effect in FaSSIF was marginal for the neutral compound (rivaroxaban) and for molecules are anionic at pH 6.5 (furosemide and niflumic acid). The higher concentration of solubilizing agents in FeSSIF improved the solubility of papaverine carrying positive charge and niflumic acid being partially zwitterionic at pH 5.0.

  3. Inter-subject variability in intestinal drug solubility.

    PubMed

    Rabbie, Sarit Cohen; Flanagan, Talia; Martin, Paul D; Basit, Abdul W

    2015-05-15

    Variability in oral drug absorption is a well-known phenomenon, but it is often overlooked for its potential effects in oral drug delivery. Understanding the mechanisms behind absorption variability is crucial to understanding and predicting drug pharmacokinetics. In this study, the solubility of furosemide and dipyridamole - drugs known to have highly variable oral bioavailabilities - was investigated in individual ileostomy fluids from 10 subjects with ulcerative colitis. For comparison, drug solubility was also determined in pooled upper gastrointestinal fluids from healthy human subjects and simulated intestinal fluids. Ileostomy fluid characterization revealed high variability in buffer capacity and to a lesser degree for pH. Drug solubility in ileostomy fluids showed high variability. Correlation analysis revealed that dipyridamole solubility in these fluids is pH-dependent, whereas furosemide solubility was highly correlated to buffer capacity and pH. The implications of these results might partly explain the high variability in bioavailability in vivo, assuming that most of the observed variability is due to the absorption, and not the elimination, process.

  4. The use of conducting polymers in membrane-based separations: a review and recent developments.

    PubMed

    Pellegrino, John

    2003-03-01

    As a material family, pi-conjugated polymers (also known as intrinsically conductive polymers) elicit the possibility of both exploiting the chemical and physical attributes of the polymer for membrane-based separations and incorporating its electronic and electrochemical properties to enhance the separation figures-of-merit. This review article, although by no means comprehensive, provides a current snapshot of the investigations from many research laboratories in the use of conducting polymers for membrane-based separations. The review focuses primarily on polyaniline, polypyrrole, and substituted-polythiophene and includes applications in gas separations, liquid (and/or vapor) separations, and ion separations. Additionally, we discuss the broad challenges and accomplishments in membrane formation from conducting polymers.

  5. A comparative study on the membrane based palm oil mill effluent (POME) treatment plant.

    PubMed

    Ahmad, A L; Chong, M F; Bhatia, S

    2009-11-15

    The discharge of palm oil mill effluent (POME) causes serious pollution problems and the membrane based POME treatment is suggested as a solution. Three different designs, namely Design A, B and C distinguished by their different types and orientations of membrane system are proposed. The results at optimum condition proved that the quality of the recovered water for all the designs met the effluent discharge standards imposed by the Department of Environment (DOE). The economic analysis at the optimum condition shows that the total treatment cost for Design A was the highest (RM 115.11/m(3)), followed by Design B (RM 23.64/m(3)) and Design C (RM 7.03/m(3)). In this study, the membrane system operated at high operating pressure with low membrane unit cost is preferable. Design C is chosen as the optimal design for the membrane based POME treatment system based on the lowest total treatment cost.

  6. Development of a two-stage membrane-based wash-water reclamation subsystem

    NASA Technical Reports Server (NTRS)

    Mccray, S. B.

    1988-01-01

    A two-stage membrane-based subsystem was designed and constructed to enable the recycle of wash waters generated in space. The first stage is a fouling-resistant tube-side-feed hollow-fiber ultrafiltration module, and the second stage is a spiral-wound reverse-osmosis module. Throughout long-term tests, the subsystem consistently produced high-quality permeate, processing actual wash water to 95 percent recovery.

  7. Supercritical fluid thermodynamics for coal processing

    SciTech Connect

    van Swol, F. . Dept. of Chemical Engineering); Eckert, C.A. . School of Chemical Engineering)

    1988-09-15

    The main objective of this research is to develop an equation of state that can be used to predict solubilities and tailor supercritical fluid solvents for the extraction and processing of coal. To meet this objective we have implemented a two-sided. approach. First, we expanded the database of model coal compound solubilities in higher temperature fluids, polar fluids, and fluid mixtures systems. Second, the unique solute/solute, solute/cosolvent and solute/solvent intermolecular interactions in supercritical fluid solutions were investigated using spectroscopic techniques. These results increased our understanding of the molecular phenomena that affect solubility in supercritical fluids and were significant in the development of an equation of state that accurately reflects the true molecular makeup of the solution. (VC)

  8. Well servicing fluid

    SciTech Connect

    Liao, A.

    1991-07-02

    This patent describes a well servicing fluid. It comprises an aqueous medium from about 0.2 to about 5 pounds per barrel of a partially hydrolyzed homopolymer of acrylamide having an average molecular weight greater than 1 million, and a calcium-controlling additive. It comprises from about 0.1 to about 2.5 pounds per barrel of the fluid of an alkali metal bicarbonate, from about 0.1 to about 2.5 pounds per barrel of the fluid of a water-soluble, carboxylic acid, and from about 0.1 to about 1.5 pounds per barrel of the fluid of a terpolymer containing from about 40 to about 70% by weight acrylamide, from about 20 to about 40% by weight of an acrylic acid and from about 5 to about 20% by weight of 2-acrylamido-2-methylpropanesulfonic acid, the terpolymer having an average molecular weight of from about 5 to about 10 million.

  9. What Variables Affect Solubility?

    ERIC Educational Resources Information Center

    Baker, William P.; Leyva, Kathryn

    2003-01-01

    Helps middle school students understand the concept of solubility through hands-on experience with a variety of liquids and solids. As they explore factors that affect solubility and saturation, students gain content mastery and an understanding of the inquiry process. Also enables teachers to authentically assess student performance on several…

  10. Applications of Solubility Data

    ERIC Educational Resources Information Center

    Tomkins, Reginald P. T.

    2008-01-01

    This article describes several applications of the use of solubility data. It is not meant to be exhaustive but rather to show that knowledge of solubility data is required in a variety of technical applications that assist in the design of chemical processes. (Contains 3 figures and 1 table.)

  11. Theoretical Analysis on Mechanical Deformation of Membrane-Based Photomask Blanks

    NASA Astrophysics Data System (ADS)

    Marumoto, Kenji; Aya, Sunao; Yabe, Hedeki; Okada, Tatsunori; Sumitani, Hiroaki

    2012-04-01

    Membrane-based photomask is used in proximity X-ray lithography including that in LIGA (Lithographie, Galvanoformung und Abformung) process, and near-field photolithography. In this article, out-of-plane deformation (OPD) and in-plane displacement (IPD) of membrane-based photomask blanks are theoretically analyzed to obtain the mask blanks with flat front surface and low stress absorber film. First, we derived the equations of OPD and IPD for the processing steps of membrane-based photomask such as film deposition, back-etching and bonding, using a theory of symmetrical bending of circular plates with a coaxial circular hole and that of deformation of cylinder under hydrostatic pressure. The validity of the equations was proved by comparing the calculation results with experimental ones. Using these equations, we investigated the relation between the geometry of the mask blanks and the distortions generally, and gave the criterion to attain the flat front surface. Moreover, the absorber stress-bias required to obtain zero-stress on finished mask blanks was also calculated and it has been found that only little stress-bias was required for adequate hole size of support plate.

  12. Remediation of textile effluents by membrane based treatment techniques: a state of the art review.

    PubMed

    Dasgupta, Jhilly; Sikder, Jaya; Chakraborty, Sudip; Curcio, Stefano; Drioli, Enrico

    2015-01-01

    The textile industries hold an important position in the global industrial arena because of their undeniable contributions to basic human needs satisfaction and to the world economy. These industries are however major consumers of water, dyes and other toxic chemicals. The effluents generated from each processing step comprise substantial quantities of unutilized resources. The effluents if discharged without prior treatment become potential sources of pollution due to their several deleterious effects on the environment. The treatment of heterogeneous textile effluents therefore demands the application of environmentally benign technology with appreciable quality water reclamation potential. These features can be observed in various innovative membrane based techniques. The present review paper thus elucidates the contributions of membrane technology towards textile effluent treatment and unexhausted raw materials recovery. The reuse possibilities of water recovered through membrane based techniques, such as ultrafiltration and nanofiltration in primary dye houses or auxiliary rinse vats have also been explored. Advantages and bottlenecks, such as membrane fouling associated with each of these techniques have also been highlighted. Additionally, several pragmatic models simulating transport mechanism across membranes have been documented. Finally, various accounts dealing with techno-economic evaluation of these membrane based textile wastewater treatment processes have been provided.

  13. A simple cellulose acetate membrane-based small lanes technique for protein electrophoresis.

    PubMed

    Na, Na; Liu, Tingting; Yang, Xiaojun; Sun, Binjie; Ouyang, Jenny; Ouyang, Jin

    2012-08-01

    Combining electrophoresis with a cellulose acetate membrane-based technique, we developed a simple and low-cost method, named cellulose acetate membrane-based small lanes (CASL), for protein electrophoresis. A home-made capillary plotter controlled by a 3D moving stage was used to create milli-to-micro channels by printing poly(dimethylsiloxane) on to a hydrophilic cellulose acetate membrane. In the hydrophilic channels, 5 nL protein mixture was separated on the basis of electro-migration under an electric field. Compared with polyacrylamide gel electrophoresis (PAGE), CASL resulted in higher protein signal intensity for separation of mixtures containing the same mass of protein. The platform was easily fabricated at low cost (approx. $0.005 for each 1-mm-wide channel), and separation of three protein mixtures was completed in 15 min. Both electrophoresis time and potential affected the separation. Rather than chromatographic separation, this method accomplished application of microchannel techniques for cellulose acetate membrane-based protein electrophoresis. It has potential in proteomic analysis, especially for rapid, low-cost, and low-volume sample analysis in clinical diagnosis.

  14. An Environmentally Friendly Process Involving Refining and Membrane-Based Electrolysis for Magnesium Recovery from Partially Oxidized Scrap Alloy

    NASA Astrophysics Data System (ADS)

    Guan, Xiaofei; Pal, Uday B.; Powell, Adam C.

    2013-10-01

    Magnesium is recovered from partially oxidized scrap alloy by combining refining and solid oxide membrane (SOM) electrolysis. In this combined process, a molten salt eutectic flux (45 wt.% MgF2-55 wt.% CaF2) containing 10 wt.% MgO and 2 wt.% YF3 was used as the medium for magnesium recovery. During refining, magnesium and its oxide are dissolved from the scrap into the molten flux. Forming gas is bubbled through the flux and the dissolved magnesium is removed via the gas phase and condensed in a separate condenser at a lower temperature. The molten flux has a finite solubility for magnesium and acts as a selective medium for magnesium dissolution, but not aluminum or iron, and therefore the magnesium recovered has high purity. After refining, SOM electrolysis is performed in the same reactor to enable electrolysis of the dissolved magnesium oxide in the molten flux producing magnesium at the cathode and oxygen at the SOM anode. During SOM electrolysis, it is necessary to decrease the concentration of the dissolved magnesium in the flux to improve the faradaic current efficiency and prevent degradation of the SOM. Thus, for both refining and SOM electrolysis, it is very important to measure and control the magnesium solubility in the molten flux. High magnesium solubility facilitates refining whereas lower solubility benefits the SOM electrolysis process. Computational fluid dynamics modeling was employed to simulate the flow behavior of the flux stirred by the forming gas. Based on the modeling results, an optimized design of the stirring tubes and its placement in the flux are determined for efficiently removing the dissolved magnesium and also increasing the efficiency of the SOM electrolysis process.

  15. What Should We Teach Beginners about Solubility and Solubility Products?

    ERIC Educational Resources Information Center

    Hawkes, Stephen J.

    1998-01-01

    Argues that consideration should be given to whether teaching solubility product calculations is at all useful. Claims that experienced teachers seriously misunderstand and misuse solubility product calculations. (DDR)

  16. Experimental measurement of solid solutes solubility in nanofluids

    NASA Astrophysics Data System (ADS)

    Fard, Manouchehr Manouchehrian; Beiki, Hossein

    2016-08-01

    The solubility of benzoic and salicylic acids was measured at a temperature range from 293 to 333 K in two types of water based nanofluids employed as the solvent. Silica and γ-alumina nanoparticles with volume concentrations of 0.025, 0.05, 0.1, 0.2 and 0.4 % were dispersed into de-ionized water as the based fluid. The results revealed that the solubility of nanofluid followed the same trend as pure water solubility with increasing temperature. At low temperatures, below 330 K for γ-Al2O3 nanofluids and 323 K for SiO2 nanofluids, nanoparticles had no effect on solubility, but by increasing the temperature, nanofluid solubility decreased. The maximum reduction in the solubility of compounds was observed at the temperature of 333 K and in 0.1 % γ-Alumina nanofluid and 0.025 % Silica nanofluids. Nanofluids solubility decreased up to a critical nanoparticles concentration while increased by increasing nanoparticles concentration further. The maximum reduction of nanofluids solubility at critical concentration was about 12.43 % for salicylic acid and 10.24 % for benzoic acid in 0.025 % SiO2 nanofluid. Nanofluids solubility was found to be strongly dependent on nanoparticles size. Bigger nanoparticles were more effective than smaller ones on nanofluids solubility.

  17. Amniotic fluid

    MedlinePlus

    ... carefully. Removing a sample of the fluid through amniocentesis can provide information about the sex, health, and development of the fetus. Images Amniocentesis Amniotic fluid Polyhydramnios Amniotic fluid References Cunningham FG, ...

  18. Learning about Solubility

    ERIC Educational Resources Information Center

    Salinas, Dino G.; Reyes, Juan G.

    2015-01-01

    Qualitative questions are proposed to assess the understanding of solubility and some of its applications. To improve those results, a simple quantitative problem on the precipitation of proteins is proposed.

  19. Protein solubility modeling

    NASA Technical Reports Server (NTRS)

    Agena, S. M.; Pusey, M. L.; Bogle, I. D.

    1999-01-01

    A thermodynamic framework (UNIQUAC model with temperature dependent parameters) is applied to model the salt-induced protein crystallization equilibrium, i.e., protein solubility. The framework introduces a term for the solubility product describing protein transfer between the liquid and solid phase and a term for the solution behavior describing deviation from ideal solution. Protein solubility is modeled as a function of salt concentration and temperature for a four-component system consisting of a protein, pseudo solvent (water and buffer), cation, and anion (salt). Two different systems, lysozyme with sodium chloride and concanavalin A with ammonium sulfate, are investigated. Comparison of the modeled and experimental protein solubility data results in an average root mean square deviation of 5.8%, demonstrating that the model closely follows the experimental behavior. Model calculations and model parameters are reviewed to examine the model and protein crystallization process. Copyright 1999 John Wiley & Sons, Inc.

  20. Optimizing solubility: kinetic versus thermodynamic solubility temptations and risks.

    PubMed

    Saal, Christoph; Petereit, Anna Christine

    2012-10-09

    The aim of this study was to assess the usefulness of kinetic and thermodynamic solubility data in guiding medicinal chemistry during lead optimization. The solubility of 465 research compounds was measured using a kinetic and a thermodynamic solubility assay. In the thermodynamic assay, polarized-light microscopy was used to investigate whether the result referred to the crystalline or to the amorphous compound. From the comparison of kinetic and thermodynamic solubility data it was noted that kinetic solubility measurements frequently yielded results which show considerably higher solubility compared to thermodynamic solubility. This observation is ascribed to the fact that a kinetic solubility assay typically delivers results which refer to the amorphous compound. In contrast, results from thermodynamic solubility determinations more frequently refer to a crystalline phase. Accordingly, thermodynamic solubility data--especially when used together with an assessment of the solid state form--are deemed to be more useful in guiding solubility optimization for research compounds.

  1. Freestanding eggshell membrane-based electrodes for high-performance supercapacitors and oxygen evolution reaction

    NASA Astrophysics Data System (ADS)

    Geng, Jing; Wu, Hao; Al-Enizi, Abdullah M.; Elzatahry, Ahmed A.; Zheng, Gengfeng

    2015-08-01

    A type of freestanding, light-weight eggshell membrane-based electrode is demonstrated for supercapacitors and for oxygen evolution reaction (OER) catalysis. As a widely available daily waste, eggshell membranes have unique porous three-dimensional grid-like fibrous structures with relatively high surface area and abundant macropores, allowing for effective conjugation of carbon nanotubes and growth of NiCo2O4 nanowire arrays, an effective supercapacitor material and OER catalyst. The three-dimensional fibrous eggshell membrane frameworks with carbon nanotubes offer efficient pathways for charge transport, and the macropores between adjacent fibers are fully accessible for electrolytes and bubble evolution. As a supercapacitor, the eggshell membrane/carbon nanotube/NiCo2O4 electrode shows high specific capacitances at current densities from 1 to 20 A g-1, with excellent capacitance retention (>90%) at 10 A g-1 for over 10 000 cycles. When employed as an OER catalyst, this eggshell membrane-based electrode exhibits an OER onset potential of 1.53 V vs. the reversible hydrogen electrode (RHE), and a stable catalytic current density of 20 mA cm-2 at 1.65 V vs. the RHE.A type of freestanding, light-weight eggshell membrane-based electrode is demonstrated for supercapacitors and for oxygen evolution reaction (OER) catalysis. As a widely available daily waste, eggshell membranes have unique porous three-dimensional grid-like fibrous structures with relatively high surface area and abundant macropores, allowing for effective conjugation of carbon nanotubes and growth of NiCo2O4 nanowire arrays, an effective supercapacitor material and OER catalyst. The three-dimensional fibrous eggshell membrane frameworks with carbon nanotubes offer efficient pathways for charge transport, and the macropores between adjacent fibers are fully accessible for electrolytes and bubble evolution. As a supercapacitor, the eggshell membrane/carbon nanotube/NiCo2O4 electrode shows high specific

  2. Freestanding eggshell membrane-based electrodes for high-performance supercapacitors and oxygen evolution reaction.

    PubMed

    Geng, Jing; Wu, Hao; Al-Enizi, Abdullah M; Elzatahry, Ahmed A; Zheng, Gengfeng

    2015-09-14

    A type of freestanding, light-weight eggshell membrane-based electrode is demonstrated for supercapacitors and for oxygen evolution reaction (OER) catalysis. As a widely available daily waste, eggshell membranes have unique porous three-dimensional grid-like fibrous structures with relatively high surface area and abundant macropores, allowing for effective conjugation of carbon nanotubes and growth of NiCo2O4 nanowire arrays, an effective supercapacitor material and OER catalyst. The three-dimensional fibrous eggshell membrane frameworks with carbon nanotubes offer efficient pathways for charge transport, and the macropores between adjacent fibers are fully accessible for electrolytes and bubble evolution. As a supercapacitor, the eggshell membrane/carbon nanotube/NiCo2O4 electrode shows high specific capacitances at current densities from 1 to 20 A g(-1), with excellent capacitance retention (>90%) at 10 A g(-1) for over 10,000 cycles. When employed as an OER catalyst, this eggshell membrane-based electrode exhibits an OER onset potential of 1.53 V vs. the reversible hydrogen electrode (RHE), and a stable catalytic current density of 20 mA cm(-2) at 1.65 V vs. the RHE.

  3. In vitro dynamic solubility test: influence of various parameters.

    PubMed Central

    Thélohan, S; de Meringo, A

    1994-01-01

    This article discusses the dissolution of mineral fibers in simulated physiological fluids (SPF), and the parameters that affect the solubility measurement in a dynamic test where an SPF runs through a cell containing fibers (Scholze and Conradt test). Solutions simulate either the extracellular fluid (pH 7.6) or the intracellular fluid (pH 4.5). The fibers have various chemical compositions and are either continuously drawn or processed as wool. The fiber solubility is determined by the amount of SiO2 (and occasionally other ions) released in the solution. Results are stated as percentage of the initial silica content released or as dissolution rate v in nm/day. The reproducibility of the test is higher with the less soluble fibers (10% solubility), than with highly soluble fibers (20% solubility). The influence of test parameters, including SPF, test duration, and surface area/volume (SA/V), has been studied. The pH and the inorganic buffer salts have a major influence: industrial glasswool composition is soluble at pH 7.6 but not at pH 4.5. The opposite is true for rock- (basalt) wool composition. For slightly soluble fibers, the dissolution rate v remains constant with time, whereas for highly soluble fibers, the dissolution rate decreases rapidly. The dissolution rates believed to occur are v1, initial dissolution rate, and v2, dissolution rate of the residual fibers. The SA of fibers varies with the mass of the fibers tested, or with the fiber diameter at equal mass. Volume, V, is the chosen flow rate. An increase in the SA/V ratio leads to a decrease in the dissolution rate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7882964

  4. Metal solubility enhancing peptides derived from barley protein.

    PubMed

    Eckert, Ewelina; Bamdad, Fatemeh; Chen, Lingyun

    2014-09-15

    Mineral supplements are required to be soluble as their bioavailability is highly correlated to their solubility in body fluids. In this study, metal binding capacity of barley protein hydrolysates and their purified fractions was investigated and expressed as increase in solubility of metal ions. Metal ions in the presence of hydrolysates exhibited a remarkable increase in solubility: 118, 32, 10, 29 and 35-fold for Fe(2+), Fe(3+), Ca(2+), Cu(2+) and Zn(2+), respectively. A mixture of low molecular weight peptides possesses a synergistic combination of both charged and hydrophobic residues and achieves the best binding metal ions. Electrostatic interactions via charged side chains and coordination binding with His and Cys, initially attract the metal ions and, afterward, hydrophobic interactions and aromatic ring stacking stabilize the positioning of metal ions in the structure of the peptide. Barley hordein hydrolysates show potential as dietary supplements that enhance both mineral solubility and bioavailability.

  5. Rocky core solubility in Jupiter and giant exoplanets.

    PubMed

    Wilson, Hugh F; Militzer, Burkhard

    2012-03-16

    Gas giants are believed to form by the accretion of hydrogen-helium gas around an initial protocore of rock and ice. The question of whether the rocky parts of the core dissolve into the fluid H-He layers following formation has significant implications for planetary structure and evolution. Here we use ab initio calculations to study rock solubility in fluid hydrogen, choosing MgO as a representative example of planetary rocky materials, and find MgO to be highly soluble in H for temperatures in excess of approximately 10,000 K, implying the potential for significant redistribution of rocky core material in Jupiter and larger exoplanets.

  6. Combined dispersant fluid loss control additives

    SciTech Connect

    Villa, J. L.; Zeiner, R. N.

    1985-12-31

    Water soluble polymer compositions containing polyacrylic acid and copolymer of itaconic acid and acrylamide are useful as combined dispersant and fluid loss control additives for aqueous drilling fluids, particularly fresh water, gypsum and seawater muds. An example is a polymer composition containing about 80% by weight polyacrylic acid and about 20% by weight copolymer of itaconic acid and acrylamide in its ammonium salt form.

  7. Soluble BACE-1 Activity and sAβPPβ Concentrations in Alzheimer's Disease and Age-Matched Healthy Control Cerebrospinal Fluid from the Alzheimer's Disease Neuroimaging Initiative-1 Baseline Cohort.

    PubMed

    Savage, Mary J; Holder, Daniel J; Wu, Guoxin; Kaplow, June; Siuciak, Judith A; Potter, William Z

    2015-01-01

    β-site amyloid precursor protein-cleaving enzyme 1 (BACE1) plays an important role in the development of Alzheimer's disease (AD), freeing the amyloid-β (Aβ) N-terminus from the amyloid-β protein precursor (AβPP), the first step in Aβ formation. Increased BACE1 activity in AD brain or cerebrospinal fluid (CSF) has been reported. Other studies, however, found either no change or a decrease with AD diagnosis in either BACE1 activity or sAβPPβ, the N-terminal secreted product of BACE1 (sBACE1) activity on AβPP. Here, sBACE1 enzymatic activity and secreted AβPPβ (sAβPPβ) were measured in Alzheimer's Disease Neuroimaging Initiative-1 (ADNI-1) baseline CSF samples and no statistically significant changes were found in either measure comparing healthy control, mild cognitively impaired, or AD individual samples. While CSF sBACE1 activity and sAβPPβ demonstrated a moderate yet significant degree of correlation with each other, there was no correlation of either analyte to CSF Aβ peptide ending at residue 42. Surprisingly, a stronger correlation was demonstrated between CSF sBACE1 activity and tau, which was comparable to that between CSF Aβ₄₂ and tau. Unlike for these latter two analytes, receiver-operator characteristic curves demonstrate that neither CSF sBACE1 activity nor sAβPPβ concentrations can be used to differentiate between healthy elderly and AD individuals.

  8. Fluorine (soluble fluoride)

    Integrated Risk Information System (IRIS)

    Fluorine ( soluble fluoride ) ; CASRN 7782 - 41 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for No

  9. Nickel, soluble salts

    Integrated Risk Information System (IRIS)

    Nickel , soluble salts ; CASRN Various Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  10. Uranium, soluble salts

    Integrated Risk Information System (IRIS)

    Uranium , soluble salts ; no CASRN Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  11. Membrane-Based Emitter for Coupling Microfluidics with Ultrasensitive Nanoelectrospray Ionization-Mass Spectrometry

    SciTech Connect

    Sun, Xuefei; Kelly, Ryan T.; Tang, Keqi; Smith, Richard D.

    2011-06-09

    An integrated poly(dimethylsiloxane) (PDMS) membrane-based microfluidic emitter for high performance nanoelectrospray ionization-mass spectrometry (nanoESI-MS) has been fabricated and evaluated. The ~100-μm-thick emitter was created by cutting a PDMS membrane that protrudes beyond the bulk substrate. The reduced surface area at the emitter enhances the electric field and reduces wetting of the surface by the electrospray solvent. As such, the emitter provides highly stable electrospray at flow rates as low as 10 nL/min, and is compatible with electrospray solvents containing a large organic component (e.g., 90% methanol). This approach enables facile emitter construction, and provides excellent stability, reproducibility and sensitivity, as well as compatibility with multilayer soft lithography.

  12. Membrane-based emitter for coupling microfluidics with ultrasensitive nanoelectrospray ionization-mass spectrometry.

    PubMed

    Sun, Xuefei; Kelly, Ryan T; Tang, Keqi; Smith, Richard D

    2011-07-15

    An integrated poly(dimethylsiloxane) (PDMS) membrane-based microfluidic emitter for high-performance nanoelectrospray ionization mass spectrometry has been fabricated and evaluated. The ∼100-μm-thick emitter was created by cutting a PDMS membrane that protrudes beyond the bulk substrate. The reduced surface area at the emitter enhances the electric field and reduces wetting of the surface by the electrospray solvent. As such, the emitter enables highly stable electrosprays at flow rates as low as 10 nL/min and is compatible with electrospray solvents containing a large organic component (e.g., 90% methanol). This approach enables facile emitter construction and provides excellent stability, reproducibility, and sensitivity as well as compatibility with multilayer soft lithography.

  13. Reduction of VOC emissions by a membrane-based gas absorption process.

    PubMed

    Li, Rui; Xu, Jun; Wang, Lianjun; Li, Jiansheng; Sun, Xiuyun

    2009-01-01

    A membrane-based gas absorption (MGA) process was evaluated for the removal of volatile organic compounds (VOCs) based on C6H6/N2 mixture. The absorption of C6H6 from a C6H6/N2 mixture was investigated using a hydrophobic polypropylene hollow fiber membrane contactor and the aqueous solution of N-formyl morpholine (NFM) as absorbent. The effects of various factors on the overall mass transfer coefficient was investigated. The experimental results showed that the removal efficiency of C6H6 could reach 99.5% in present studied system. A mathematical model based on resistance-in-series concept was presented to predict the value of overall mass transfer coefficient. The average error between the predicted and experimental values is 7.9%. In addition, conventional packed columns for VOCs removal was also evaluated for comparison.

  14. Ultrasensitive cDNA Detection of Dengue Virus RNA Using Electrochemical Nanoporous Membrane-Based Biosensor

    PubMed Central

    Rai, Varun; Hapuarachchi, Hapuarachchige C.; Ng, Lee Ching; Soh, Siew Hwa; Leo, Yee Sin; Toh, Chee-Seng

    2012-01-01

    A nanoporous alumina membrane-based ultrasensitive DNA biosensor is constructed using 5′-aminated DNA probes immobilized onto the alumina channel walls. Alumina nanoporous membrane-like structure is carved over platinum wire electrode of 76 µm diameter dimension by electrochemical anodization. The hybridization of complementary target DNA with probe DNA molecules attached inside the pores influences the pore size and ionic conductivity. The biosensor demonstrates linear range over 6 order of magnitude with ultrasensitive detection limit of 9.55×10−12 M for the quantification of ss-31 mer DNA sequence. Its applicability is challenged against real time cDNA PCR sample of dengue virus serotype1 derived from asymmetric PCR. Excellent specificity down to one nucleotide mismatch in target DNA sample of DENV3 is also demonstrated. PMID:22927927

  15. Green materials science and engineering reduces biofouling: approaches for medical and membrane-based technologies

    PubMed Central

    Dobosz, Kerianne M.; Kolewe, Kristopher W.; Schiffman, Jessica D.

    2015-01-01

    Numerous engineered and natural environments suffer deleterious effects from biofouling and/or biofilm formation. For instance, bacterial contamination on biomedical devices pose serious health concerns. In membrane-based technologies, such as desalination and wastewater reuse, biofouling decreases membrane lifetime, and increases the energy required to produce clean water. Traditionally, approaches have combatted bacteria using bactericidal agents. However, due to globalization, a decline in antibiotic discovery, and the widespread resistance of microbes to many commercial antibiotics and metallic nanoparticles, new materials, and approaches to reduce biofilm formation are needed. In this mini-review, we cover the recent strategies that have been explored to combat microbial contamination without exerting evolutionary pressure on microorganisms. Renewable feedstocks, relying on structure-property relationships, bioinspired/nature-derived compounds, and green processing methods are discussed. Greener strategies that mitigate biofouling hold great potential to positively impact human health and safety. PMID:25852659

  16. Preparation, Characterization, and Analytical Application of Ramipril Membrane-Based Ion-Selective Electrode

    PubMed Central

    Arida, Hassan; Ahmed, Mona; Ali, Abdallah

    2009-01-01

    The fabrication and electrochemical evaluation of two PVC membrane-based Ion-Selective electrodes responsive for ramipril drug have been proposed. The sensitive membranes were prepared using ramipril-phosphomolibdate and ramipril-tetraphenylborate ion-pair complexes as electroactive sensing materials in plasticized PVC support. The electrodes based on these materials provide near-Nernestian response (sensitivity of 53 ± 0.5–54 ± 0.5 mV/concentration decade) covering the concentration range of 1.0 × 10−2–1.0 × 10−5 mol L−1 with a detection limit of 3.0 × 10−6–4.0 × 10−6 mol L−1. The suggested electrodes have been successfully used in the determination of ramipril drug in some pharmaceutical formulations using direct potentiometry with average recovery of >96% and mean standard deviation of <3% (n = 5). PMID:20140081

  17. Modeling and Simulation of Membrane-Based Dehumidification and Energy Recovery Process

    SciTech Connect

    Gao, Zhiming; Abdelaziz, Omar; Qu, Ming

    2017-01-01

    This paper introduces a first-order physics-based model that accounts for the fundamental heat and mass transfer between a humid-air vapor stream on feed side to another flow stream on permeate side. The model comprises a few optional submodels for membrane mass transport; and it adopts a segment-by-segment method for discretizing heat and mass transfer governing equations for flow streams on feed and permeate sides. The model is able to simulate both dehumidifiers and energy recovery ventilators in parallel-flow, cross-flow, and counter-flow configurations. The predicted tresults are compared reasonably well with the measurements. The open-source codes are written in C++. The model and open-source codes are expected to become a fundament tool for the analysis of membrane-based dehumidification in the future.

  18. Green materials science and engineering reduces biofouling: approaches for medical and membrane-based technologies.

    PubMed

    Dobosz, Kerianne M; Kolewe, Kristopher W; Schiffman, Jessica D

    2015-01-01

    Numerous engineered and natural environments suffer deleterious effects from biofouling and/or biofilm formation. For instance, bacterial contamination on biomedical devices pose serious health concerns. In membrane-based technologies, such as desalination and wastewater reuse, biofouling decreases membrane lifetime, and increases the energy required to produce clean water. Traditionally, approaches have combatted bacteria using bactericidal agents. However, due to globalization, a decline in antibiotic discovery, and the widespread resistance of microbes to many commercial antibiotics and metallic nanoparticles, new materials, and approaches to reduce biofilm formation are needed. In this mini-review, we cover the recent strategies that have been explored to combat microbial contamination without exerting evolutionary pressure on microorganisms. Renewable feedstocks, relying on structure-property relationships, bioinspired/nature-derived compounds, and green processing methods are discussed. Greener strategies that mitigate biofouling hold great potential to positively impact human health and safety.

  19. Analysis of a membrane-based condesate recovery heat exchanger (CRX)

    NASA Technical Reports Server (NTRS)

    Newbold, D.D.

    1993-01-01

    The development of a temperature and humidity control system that can remove heat and recover water vapor is key to the development of an Environmental Control and Life Support System (ECLSS). Large quantities of water vapor must be removed from air, and this operation has proven difficult in the absense of gravity. This paper presents the modeling results from a program to develop a novel membrane-based heat exchanger known as the condensate recovery heat exchanger (CRX). This device cools and dehumidifies humid air and simultaneously recovers water-vapor condensate. In this paper, the CRX is described and the results of an analysis of the heat- and mass-transfer characteristics of the device are given.

  20. Development of Membrane-Based Desiccant Fiber for Vacuum Desiccant Cooling.

    PubMed

    Yang, Yifan; Rana, Dipak; Lan, Christopher Q; Matsuura, Takeshi

    2016-06-22

    A novel hydrophobic membrane-based desiccant fiber (MDF) was developed by loading lithium chloride into hydrophobic hollow fiber membranes. The MDF thus made was then tested for vapor absorption under controlled conditions. Furthermore, an MDF pad, which was made by weaving MDF into a piece of garment, was built into a laboratory vacuum desiccant cooling (VDC) setup, which included the MDF pad as the desiccant layer and a cooling towel saturated with water as the water reservoir, to test the cooling effects at atmospheric pressure and vacuum of 25 in. of Hg. Results indicate that MDF is suitable for applications such as in VDC. Mass and heat transfer of vapor absorption by MDF were also analyzed.

  1. A membrane-based subsystem for very high recoveries of spacecraft waste waters

    NASA Technical Reports Server (NTRS)

    Ray, Roderick J.; Retzlaff, Sandra E.; Radke-Mitchell, Lyn; Newbold, David D.; Price, Donald F.

    1986-01-01

    This paper describes the continued development of a membrane-based subsystem designed to recover up to 99.5 percent of the water from various spacecraft waste waters. Specifically discussed are: (1) the design and fabrication of an energy-efficient reverse-osmosis (RO) breadboard subsystem; (2) data showing the performance of this subsystem when operated on a synthetic wash-water solution - including the results of a 92-day test; and (3) the results of pasteurization studies, including the design and operation of an in-line pasteurizer. Also included in this paper is a discussion of the design and performance of a second RO stage. This second stage results in higher-purity product water at a minimal energy requirement and provides a substantial redundancy factor to this subsystem.

  2. Microfabrication of membrane-based devices by deep-reactive ion etching (DRIE) of silicon

    SciTech Connect

    Manginell, R.P.; Frye-Mason, G.C.; Schubert, W.K.; Shul, R.J.; Willison, C.G.

    1998-08-01

    Deep reactive ion etching (DRIE) of silicon was utilized to fabricate dielectric membrane-based devices such as microhotplates, valves and flexural plate wave (FPW) devices. Through-wafer DRIE is characterized by fast etch rates ({approximately} 3 {micro}m/min), crystal orientation independence, vertical sidewall profiles and CMOS compatibility. Low-stress silicon nitride, a popular membrane material, has an appreciable DRIE etch rate. To overcome this limitations DRIE can be accompanied by a brief wet chemical etch. This approach has been demonstrated using KOH or HF/Nitric/Acetic etchants, both of which have significantly lower etch rates on silicon nitride than does DRIE. The DRIE etch properties of composite membranes consisting of silicon dioxide and silicon nitride layers are also under evaluation due to the higher DRIE selectivity to silicon dioxide.

  3. Multifunctional membranes based on spinning technologies: the synergy of nanofibers and nanoparticles

    NASA Astrophysics Data System (ADS)

    Roso, Martina; Sundarrajan, Subramanian; Pliszka, Damian; Ramakrishna, Seeram; Modesti, Michele

    2008-07-01

    A multicomponent membrane based on polysulfone nanofibers and titanium dioxide nanoparticles is produced by the coupling of electrospinning and electrospraying techniques. The manufactured product can satisfy a number of conflicting requirements begetting its technical and functional versatility as well as the reliability of the process. As nanoparticle dispersion is a critical issue in nanoparticle technology, their distribution and morphology have been extensively studied before and after electrospraying, and process optimization has been carried out to obtain nanoparticles uniformly spread over electrospun nanofibers. These membranes have been proved to be a good candidate for supported catalysis due to the photocatalytic activity of TiO2, tested for degradation of CEPS, a mustard agent simulant. At the same time, an effective improvement in filtering properties in terms of pressure drop has also been studied.

  4. Membrane-based recovery of glucose from enzymatic hydrolysis of ionic liquid pretreated cellulose.

    PubMed

    Abels, Christian; Thimm, Kristof; Wulfhorst, Helene; Spiess, Antje Christine; Wessling, Matthias

    2013-12-01

    In this work, a membrane-based downstream process for the recovery of glucose from cellulose hydrolysis is described and evaluated. The cellulose is pretreated with the ionic liquid 1,3-dimethyl-imidazolium dimethylphosphate to reduce its crystallinity. After enzymatic conversion of cellulose to glucose the hydrolysate is filtered with an ultrafiltration membrane to remove residual particulates and enzymes. Nanofiltration is applied to purify the glucose from molecular intermediates, such as cellobiose originating from the hydrolysis reaction. Finally, the ionic liquid is removed from the hydrolysate via electrodialysis. Technically, these process steps are feasible. An economic analysis of the process reveals that the selling price of glucose from this production process is about 2.75 €/kg which is too high as compared to the current market price.

  5. Angiogenesis mediated by soluble forms of E-selectin and vascular cell adhesion molecule-1

    NASA Astrophysics Data System (ADS)

    Koch, Alisa E.; Halloran, Margaret M.; Haskell, Catherine J.; Shah, Manisha R.; Polverini, Peter J.

    1995-08-01

    ENDOTHELIAL adhesion molecules facilitate the entry of leukocytes into inflamed tissues. This in turn promotes neovascularization, a process central to the progression of rheumatoid arthritis, tumour growth and wound repair1. Here we test the hypothesis that soluble endothelial adhesion molecules promote angiogenesis2á¤-4. Human recombinant soluble E-selectin and soluble vascular cell adhesion molecule-1 induced chemotaxis of human endothelial cells in vitro and were angiogenic in rat cornea. Soluble E-selectin acted on endothelial cells in part through a sialyl Lewis-X-dependent mechanism, while soluble vascular cell adhesion molecule-1 acted on endothelial cells in part through a very late antigen (VLA)-4 dependent mechanism. The chemotactic activity of rheumatoid synovial fluid for endothelial cells, and also its angiogenic activity, were blocked by antibodies to either soluble E-selectin or soluble vascular cell adhesion molecule-1. These results suggest a novel function for soluble endothelial adhesion molecules as mediators of angiogenesis.

  6. Measurement and Accurate Interpretation of the Solubility of Pharmaceutical Salts.

    PubMed

    He, Yan; Ho, Chris; Yang, Donglai; Chen, Jeane; Orton, Edward

    2017-01-30

    Salt formation is one of the primary approaches to improve the developability of ionizable poorly water-soluble compounds. Solubility determination of the salt candidates in aqueous media or biorelevant fluids is a critical step in salt screening. Salt solubility measurements can be complicated due to dynamic changes in both solution and solid phases. Because of the early implementation of salt screening in research, solubility measurements often are performed using minimal amount of material. Some salts have transient high solubility on dissolution. Recognition of these transients can be critical in developing these salts into drug products. This minireview focuses on challenges in salt solubility measurements due to the changes in solution caused by self-buffering effects of dissolved species and the changes in solid phase due to solid-state phase transformations. Solubility measurements and their accurate interpretation are assessed in the context of dissolution monitoring and solid-phase analysis technologies. A harmonized method for reporting salt solubility measurements is recommended to reduce errors and to align with the U.S. Pharmacopeial policy and Food and Drug Administration recommendations for drug products containing pharmaceutical salts.

  7. Solubility enhancement of rosiglitazone by using melt sonocrystallization technique.

    PubMed

    Jagtap, Vaibhavkumar A; Vidyasagar, G; Dvivedi, S C

    2014-03-01

    The poor solubility and low dissolution rate in gastro-intestinal fluid, especially for class-II drugs according to Biopharmaceutics Classification System (BCS) the bioavailability enhanced by increasing the solubility and dissolution rate. A novel melt sonocrystallization technique of particle engineering to enhance solubility as well as dissolution of hydrophobic drug and to study its effect on crystal properties of drug. The present study leads to use investigate solubility of melt sonocrystallization technique to modify the undesirable properties of Rosiglitazone is antidiabetic drug in thiozolidione category with (BCS II) to forms agglomerates with number of shallow circular pits on the surface leads to increase solubility. Melt sonocrystallization process was developed for Rosiglitazone in which Rosiglitazone melt was poured in deionized water and simultaneously subjected to ultrasonic energy for 20 min at amplitude 80 %. The product obtained was evaluated using scanning electron microscopy, differential scanning calorimetry, X-ray powder diffractometry (XPRD), Fourier transformed infrared spectroscopy (FTIR), solubility and dissolution rate. The irregular agglomerates with porous surface were obtained having different crystal habit which increases solubility and dissolution rate. FTIR shows thermal behavior of untreated Rosiglitazone and treated Rosiglitazone have no significant difference low intensity peaks in XPRD of treated Rosiglitazone were noticed crystals habit changes and lattice defects during processing have causes favorable changes in the physicochemical properties of Rosiglitazone. The use of melt sonocrystallization technique is promising technique that may affords powder with improved flow as well as improved solubility and dissolution.

  8. Fluid Mechanics.

    ERIC Educational Resources Information Center

    Drazin, Philip

    1987-01-01

    Outlines the contents of Volume II of "Principia" by Sir Isaac Newton. Reviews the contributions of subsequent scientists to the physics of fluid dynamics. Discusses the treatment of fluid mechanics in physics curricula. Highlights a few of the problems of modern research in fluid dynamics. Shows that problems still remain. (CW)

  9. Formulation of soluble oils with synthetic and petroleum sulfonates

    SciTech Connect

    Eckard, A.; Riff, I.; Weaver, J.

    1997-06-01

    Metalworking fluids for metal removal are formulated to provide cooling, lubrication, and rust protection when cutting and machining metals. There are basically four types of cutting fluids: straight oils, synthetics, semisynthetic fluids and soluble oils. The last type is the most widely used for metal removal operations such as cutting, drilling and grinding. Soluble oils used for metalworking operations are normally the oil-in-water type, with oil as the internal phase and water as the external phase. The soluble oils can have rather complex compositions, usually containing two or more emulsifiers and coupling agents, as well as additives to provide rust inhibition, lubricity, detergency, resistance to bacterial attack and foam control. The dominant emulsifier in a soluble oil is usually sodium sulfonate which also has the secondary benefit of being a rust inhibitor. Soluble oil emulsions based on petroleum or synthetic sulfonates have been found to improve lubrication and cleaning of metal parts and equipment. As has been done previously, a series of emulsification studies were conducted using petroleum and synthetic sulfonates. Emulsifier level, coemulsifiers and minor formulation adjustments were made to optimize each system. This study was made using naphthenic oil basestock. Formulations were evaluated using criteria including concentrate stability, hard and soft water emulsion stability, emulsibility, foaming tendency and response to defoamers, antirust properties and cost effectiveness of individual formulations. The results of these evaluations are presented in the present paper.

  10. Soluble and insoluble fiber (image)

    MedlinePlus

    Dietary fiber is the part of food that is not affected by the digestive process in the body. ... of the stool. There are two types of dietary fiber, soluble and insoluble. Soluble fiber retains water and ...

  11. A Perspective on Solubility Rules.

    ERIC Educational Resources Information Center

    Monroe, Manus; Abrams, Karl

    1984-01-01

    Presents four generalizations about solubilities. These generalizations (rules), are useful in introducing the dynamic topics of solubility and in helping high school and introductory college chemistry students make some order out of the tremendous number of facts available. (JN)

  12. Viscous fingering with partial miscible fluids

    NASA Astrophysics Data System (ADS)

    Fu, Xiaojing; Cueto-Felgueroso, Luis; Juanes, Ruben

    2015-11-01

    When a less viscous fluid displaces a more viscous fluid, the contrast in viscosity destabilizes the interface between the two fluids, leading to the formation of fingers. Studies of viscous fingering have focused on fluids that are either fully miscible or perfectly immiscible. In practice, however, the miscibility of two fluids can change appreciably with temperature and pressure, and often falls into the case of partial miscibility, where two fluids have limited solubility in each other. Following our recent work for miscible (Jha et al., PRL 2011, 2013) and immiscible systems (Cueto-Felgueroso and Juanes, PRL 2012, JFM 2014), here we propose a phase-field model for fluid-fluid displacements in a Hele-Shaw cell, when the two fluids have limited (but nonzero) solubility in one another. Partial miscibility is characterized through the design of thermodynamic free energy of the two-fluid system. We elucidate the key dimensionless groups that control the behavior of the system. We present high-resolution numerical simulations of the model applied to the viscous fingering problem. On one hand, we demonstrate the effect of partial miscibility on the hydrodynamic instability. On the other, we elucidate the role of the degree of fingering on the rate of mutual fluid dissolution.

  13. Electrorheological fluids

    SciTech Connect

    Adolf, D.; Anderson, R.; Garino, T.; Halsey, T.C.; Hance, B.; Martin, J.E.; Odinek, J.

    1996-10-01

    An Electrorheological fluid is normally a low-viscosity colloidal suspension, but when an electric field is applied, the fluid undergoes a reversible transition to a solid, being able to support considerable stress without yield. Commercial possibilities for such fluids are enormous, including clutches, brakes, valves,shock absorbers, and stepper motors. However, performance of current fluids is inadequate for many proposed applications. Our goal was to engineer improved fluids by investigating the key technical issues underlying the solid-phase yield stress and the liquid to solid switching time. Our studies focused on field-induced interactions between colloidal particles that lead to solidification, the relation between fluid structure and performance (viscosity, yield stress), and the time evolution of structure in the fluid as the field is switched on or off.

  14. Anhydrite solubility in differentiated arc magmas

    NASA Astrophysics Data System (ADS)

    Masotta, M.; Keppler, H.

    2015-06-01

    The solubility of anhydrite in differentiated arc magmas was experimentally studied at 200 MPa and 800-1000 °C over a range of oxygen fugacities, from 0.5 log units above the Ni-NiO buffer to the hematite-magnetite buffer. Anhydrite is stable only at oxidizing conditions (fO2 ⩾ Re-ReO2), whereas sulfides only form under reducing conditions. The solubility of anhydrite in the melt ultimately regulates the amount of sulfur available to partition between melt and fluid phase during the eruption. At oxidizing conditions, the solubility product of anhydrite increases with temperature, nbo/t and melt water content. We provide a new calibration of the anhydrite solubility product (KSP = XCaO * XSO3), which reproduces all available experimental data with greatly improved accuracy: In this equation, the molar fractions XCaO and XSO3 in the melt as well as the number of non-bridging oxygen atoms per tetrahedron (nbo/t) are calculated on an anhydrous basis (H2O refers to the melt water content, T is temperature in Kelvin). We apply our model to estimate the sulfur yield of some recent volcanic eruptions and we show that the sulfur yield of the 1991 Mt. Pinatubo dacite eruption was unusually large, because only a small fraction of the sulfur was locked up in anhydrite. In general, high sulfur yields are expected when anhydrite solubility in the melt is high, i.e. for somewhat depolymerized melts. For rhyolitic systems, most of the available sulfur will be locked up in anhydrite, so that even very large eruptions may only have a small effect on global surface temperatures. Our model therefore allows improved predictions of the environmental impact of explosive volcanic eruptions.

  15. IMMUNOLOGICAL REACTIONS OF PNEUMONIC PLEURAL FLUIDS

    PubMed Central

    Finland, Maxwell

    1932-01-01

    Pleuritic exudates from patients with lobar pneumonia may be sterile or infected. Sterile fluids, at or about the time of crisis, contain actively acquired antibodies similar to those in the blood serum. Infected fluids do not contain such antibodies, presumably because of the presence in them of large amounts of soluble specific substance. Sterile fluids from patients treated with immune sera have both horse serum and antibodies similar to those injected. Infected fluids from serum-treated cases contain horse serum and such heterologous antibodies as were contained in the therapeutic sera together with homologous soluble specific substance. The concentration of horse serum and antibodies in pneumonic fluids is usually the same or somewhat less than that of the corresponding blood sera. PMID:19869983

  16. An Investigation of Dental Luting Cement Solubility as a Function of the Marginal Gap.

    DTIC Science & Technology

    1988-05-01

    be non-irritating to the dental pulp , and have low solubility. A critical property of luting cement is its solubility in oral fluids. If the cement...25 micron and 100 micron cement margins. In another investigation, hollow orthodontic tubing and the acid etch composite resin technique were used to...evaluate cement solubility. (lbbetson 1985) Hollow orthodontic tubing, with a 0.05 mm diameter, was filled with dental cement and attached to the

  17. Comparison of biorelevant simulated media mimicking the intestinal environment to assess the solubility profiles of poorly soluble drugs.

    PubMed

    Prasad, Dev; Gu, Chong-Hui; Kuldipkumar, Anuj

    2016-01-01

    During the discovery stage in lead identification/optimization, compounds are characterized for their solubilities in biorelevant media and these data are often used to model the in vivo behavior of the compounds and predict the fraction absorbed. These media are selected to closely approximate the composition of human intestinal fluid. Owing to the complexity and variability in human intestinal fluid composition, it is essential that the chosen simulated media mimic the in vivo condition as closely as possible. Several recipes have been developed and are routinely used in assessing the solubilities of compounds. It is necessary to revisit these recipes and modify them as the understanding of the human GI tract increases. In the present work, we have evaluated the solubilities of six model compounds in several media and have proposed slight modifications to the currently used recipes based on our own data and that reported in the literature.

  18. Bioconcentration factors and lipid solubility

    SciTech Connect

    Banerjee, S. ); Baughman, G.L. )

    1991-03-01

    The log-log relationship between bioconcentration and hydrophobicity breaks down for several medium and high molecular weight solutes that bioconcentrate either to a small extent or not at all. Much of the failure is attributed to the relatively low solubility of these compounds in lipid. Inclusion of a term in octanol solubility (in place of lipid solubility, which is generally unavailable) considerably improves the quality of the relationship (r = 0.95). It is speculated that the octanol solubility term compensates for the relatively low solubility of large compounds in lipid.

  19. Solubility and Solubility Product Determination of a Sparingly Soluble Salt: A First-Level Laboratory Experiment

    ERIC Educational Resources Information Center

    Bonomo, Raffaele P.; Tabbi, Giovanni; Vagliasindi, Laura I.

    2012-01-01

    A simple experiment was devised to let students determine the solubility and solubility product, "K"[subscript sp], of calcium sulfate dihydrate in a first-level laboratory. The students experimentally work on an intriguing equilibrium law: the constancy of the product of the ion concentrations of a sparingly soluble salt. The determination of…

  20. Soluble porphyrin polymers

    DOEpatents

    Gust, Jr., John Devens; Liddell, Paul Anthony

    2015-07-07

    Porphyrin polymers of Structure 1, where n is an integer (e.g., 1, 2, 3, 4, 5, or greater) ##STR00001## are synthesized by the method shown in FIGS. 2A and 2B. The porphyrin polymers of Structure 1 are soluble in organic solvents such as 2-MeTHF and the like, and can be synthesized in bulk (i.e., in processes other than electropolymerization). These porphyrin polymers have long excited state lifetimes, making the material suitable as an organic semiconductor for organic electronic devices including transistors and memories, as well as solar cells, sensors, light-emitting devices, and other opto-electronic devices.

  1. Parallel detection of harmful algae using reverse transcription polymerase chain reaction labeling coupled with membrane-based DNA array.

    PubMed

    Zhang, Chunyun; Chen, Guofu; Ma, Chaoshuai; Wang, Yuanyuan; Zhang, Baoyu; Wang, Guangce

    2014-03-01

    Harmful algal blooms (HABs) are a global problem, which can cause economic loss to aquaculture industry's and pose a potential threat to human health. More attention must be made on the development of effective detection methods for the causative microalgae. The traditional microscopic examination has many disadvantages, such as low efficiency, inaccuracy, and requires specialized skill in identification and especially is incompetent for parallel analysis of several morphologically similar microalgae to species level at one time. This study aimed at exploring the feasibility of using membrane-based DNA array for parallel detection of several microalgae by selecting five microaglae, including Heterosigma akashiwo, Chaetoceros debilis, Skeletonema costatum, Prorocentrum donghaiense, and Nitzschia closterium as test species. Five species-specific (taxonomic) probes were designed from variable regions of the large subunit ribosomal DNA (LSU rDNA) by visualizing the alignment of LSU rDNA of related species. The specificity of the probes was confirmed by dot blot hybridization. The membrane-based DNA array was prepared by spotting the tailed taxonomic probes onto positively charged nylon membrane. Digoxigenin (Dig) labeling of target molecules was performed by multiple PCR/RT-PCR using RNA/DNA mixture of five microalgae as template. The Dig-labeled amplification products were hybridized with the membrane-based DNA array to produce visible hybridization signal indicating the presence of target algae. Detection sensitivity comparison showed that RT-PCR labeling (RPL) coupled with hybridization was tenfold more sensitive than DNA-PCR-labeling-coupled with hybridization. Finally, the effectiveness of RPL coupled with membrane-based DNA array was validated by testing with simulated and natural water samples, respectively. All of these results indicated that RPL coupled with membrane-based DNA array is specific, simple, and sensitive for parallel detection of microalgae which

  2. High temperature fuel cell membranes based on poly(arylene ether)s containing benzimidazole groups

    SciTech Connect

    Kim, Dae Sik; Kim, Yu Seung; Lee, Kwan - Soo; Boncella, James M; Kuiper, David; Guiver, Michael D

    2009-01-01

    Development of new high-performance polymer membranes that retain their proton conductivity under low humidity conditions is one of the most critical requirements to commercialize PEMFC systems. Current sulfonated proton exchange membranes acquire proton conductivity by water that solvates ion and carries proton. Consequently, a loss of water under low RH conditions immediately results in a loss of proton conductivity. One approach to maintain proton conductivity under low RH conditions is to replace water with a less volatile proton solvent. Kreuer has pointed out the possibility to develop fully polymeric proton-conducting membranes based on nitrogen-containing heterocycles such as imidazole, benzimidazole, and pyrazole. We have attempted to blend those less volatile proton solvent with sulfonated copolymers such as polystyrene sulfonic acid, Nafion, poly(arylene ether sulfone, BPSH-xx). [Ref. DOE review meeting 2007 and 2008] However, we observed that imidazole was slowly sublimated out as temperature and humidity increases which could cause poisoning of electro-catalyst, corrosion and losing conductivity. In this presentation, we report the synthesis of novel poly(arylene ether sulfone)s containing benzimidazole groups These benzimidazole containing polymer was blended with sulfonated poly(arylene ether sulfone). In the blend system, benzimidazole group attached to the polysulfone acts as a medium through the basic nitrogen for transfer of protons between the sulfonic acid groups. Proton conductivity of the blend membranes was investigated as a function of water content at 80 C and compared the performance with water based proton conduction system.

  3. A membrane-based subsystem for water-vapor recovery from plant-growth chambers

    NASA Technical Reports Server (NTRS)

    Ray, R. J.

    1992-01-01

    Bioregenerative systems--life-support systems to regenerate oxygen, food, and water--are the key to establishing man's permanent presence in space. NASA is investigating the use of plant-growth chambers (PGC's) for space missions and for bases on the moon and Mars. PGC's serve several important purposes, including the following: (1) oxygen and food production; (2) carbon-dioxide removal; and (3) water purification and reuse. The key to the successful development of PGC's is a system to recover and reuse the water vapor that is transpired by the leaves of the growing plants. In this program we propose to develop a simple, reliable, membrane-based system that allows the recovery, purification, and reuse of the transpired water vapor through control of temperature and humidity levels in the PGC. This system has characteristics that make it ideally suited to use in space: (1) minimal power requirements; (2) small volume and mass; (3) simplicity; (4) reliability; and (5) versatility. In Phase 1 we will do the following: (1) develop an accurate, predictive model of our temperature- and humidity-control system, based on parametric tests of membrane modules; and (2) use this model to design systems for selected PGC's. In Phase 2, we will seek to design, fabricate, test, and deliver a breadboard unit to NASA for testing on a PGC.

  4. 2D fluorescence spectroscopy for monitoring ion-exchange membrane based technologies - Reverse electrodialysis (RED).

    PubMed

    Pawlowski, Sylwin; Galinha, Claudia F; Crespo, João G; Velizarov, Svetlozar

    2016-01-01

    Reverse electrodialysis (RED) is one of the emerging, membrane-based technologies for harvesting salinity gradient energy. In RED process, fouling is an undesirable operation constraint since it leads to a decrease of the obtainable net power density due to increasing stack electric resistance and pressure drop. Therefore, early fouling detection is one of the main challenges for successful RED technology implementation. In the present study, two-dimensional (2D) fluorescence spectroscopy was used, for the first time, as a tool for fouling monitoring in RED. Fluorescence excitation-emission matrices (EEMs) of ion-exchange membrane surfaces and of natural aqueous streams were acquired during one month of a RED stack operation. Fouling evolvement on the ion-exchange membrane surfaces was successfully followed by 2D fluorescence spectroscopy and quantified using principal components analysis (PCA). Additionally, the efficiency of cleaning strategy was assessed by measuring the membrane fluorescence emission intensity before and after cleaning. The anion-exchange membrane (AEM) surface in contact with river water showed to be significantly affected due to fouling by humic compounds, which were found to cross through the membrane from the lower salinity (river water) to higher salinity (sea water) stream. The results obtained show that the combined approach of using 2D fluorescence spectroscopy and PCA has a high potential for studying fouling development and membrane cleaning efficiency in ion exchange membrane processes.

  5. Improved Membrane-Based Sensor Network for Reliable Gas Monitoring in the Subsurface

    PubMed Central

    Lazik, Detlef; Ebert, Sebastian

    2012-01-01

    A conceptually improved sensor network to monitor the partial pressure of CO2 in different soil horizons was designed. Consisting of five membrane-based linear sensors (line-sensors) each with 10 m length, the set-up enables us to integrate over the locally fluctuating CO2 concentrations (typically lower 5%vol) up to the meter-scale gaining valuable concentration means with a repetition time of about 1 min. Preparatory tests in the laboratory resulted in a unexpected highly increased accuracy of better than 0.03%vol with respect to the previously published 0.08%vol. Thereby, the statistical uncertainties (standard deviations) of the line-sensors and the reference sensor (nondispersive infrared CO2-sensor) were close to each other. Whereas the uncertainty of the reference increases with the measurement value, the line-sensors show an inverse uncertainty trend resulting in a comparatively enhanced accuracy for concentrations >1%vol. Furthermore, a method for in situ maintenance was developed, enabling a proof of sensor quality and its effective calibration without demounting the line-sensors from the soil which would disturb the established structures and ongoing processes. PMID:23235447

  6. Novel Membrane-Based Electrochemical Sensor for Real-Time Bio-Applications

    PubMed Central

    Alatraktchi, Fatima AlZahra'a; Bakmand, Tanya; Dimaki, Maria; Svendsen, Winnie E.

    2014-01-01

    This article presents a novel membrane-based sensor for real-time electrochemical investigations of cellular- or tissue cultures. The membrane sensor enables recording of electrical signals from a cell culture without any signal dilution, thus avoiding loss of sensitivity. Moreover, the porosity of the membrane provides optimal culturing conditions similar to existing culturing techniques allowing more efficient nutrient uptake and molecule release. The patterned sensor electrodes were fabricated on a porous membrane by electron-beam evaporation. The electrochemical performance of the membrane electrodes was characterized by cyclic voltammetry and chronoamperometry, and the detection of synthetic dopamine was demonstrated down to a concentration of 3.1 pM. Furthermore, to present the membrane-sensor functionality the dopamine release from cultured PC12 cells was successfully measured. The PC12 cells culturing experiments showed that the membrane-sensor was suitable as a cell culturing substrate for bio-applications. Real-time measurements of dopamine exocytosis in cell cultures were performed, where the transmitter release was recorded at the point of release. The developed membrane-sensor provides a new functionality to the standard culturing methods, enabling sensitive continuous in vitro monitoring and closely mimicking the in vivo conditions. PMID:25421738

  7. Conductivity Scaling Relationships in Nanostructured Membranes based on Protic Polymerized Ionic Liquids

    NASA Astrophysics Data System (ADS)

    Sanoja, Gabriel; Lynd, Nathaniel; Segalman, Rachel

    2015-03-01

    Nanostructured membranes based on protic polymerized ionic liquids are of great interest for a variety of electrochemical applications. Understanding the relationship between composition, structure, and ionic conductivity for these materials is essential for designing novel membranes with improved properties. In this work, we explore the effect of volume fraction of ionic liquid on conductivity, σ using a model system composed of poly[isoprene-block-(ethylene oxide-stat-histamine glycidyl ether) diblock copolymers [PI- b - P(EO-stat-HGE)] and the resulting [PI- b - P(EO-stat-IL)] obtained after treatment with trifluoroacetic acid. These materials self-assemble into lamellar structures with volume fractions of ionic liquid ranging from 0.50 to 0.90 as demonstrated by SAXS. PI- b - P(EO-stat-IL) membranes exhibit conductivities up to 4 x 10-3 S/cm at room temperature. In addition, PI- b - P(EO-stat-IL) based membranes have lower water uptake (λ = 8-10) in comparison with most proton conducting membranes reported elsewhere. The low λ in these membranes might translate into a stronger effect of morphology on transport properties. Joint Center for Artificial Photosynthesis.

  8. Approach for Self-Calibrating CO₂ Measurements with Linear Membrane-Based Gas Sensors.

    PubMed

    Lazik, Detlef; Sood, Pramit

    2016-11-17

    Linear membrane-based gas sensors that can be advantageously applied for the measurement of a single gas component in large heterogeneous systems, e.g., for representative determination of CO₂ in the subsurface, can be designed depending on the properties of the observation object. A resulting disadvantage is that the permeation-based sensor response depends on operating conditions, the individual site-adapted sensor geometry, the membrane material, and the target gas component. Therefore, calibration is needed, especially of the slope, which could change over several orders of magnitude. A calibration-free approach based on an internal gas standard is developed to overcome the multi-criterial slope dependency. This results in a normalization of sensor response and enables the sensor to assess the significance of measurement. The approach was proofed on the example of CO₂ analysis in dry air with tubular PDMS membranes for various CO₂ concentrations of an internal standard. Negligible temperature dependency was found within an 18 K range. The transformation behavior of the measurement signal and the influence of concentration variations of the internal standard on the measurement signal were shown. Offsets that were adjusted based on the stated theory for the given measurement conditions and material data from the literature were in agreement with the experimentally determined offsets. A measurement comparison with an NDIR reference sensor shows an unexpectedly low bias (<1%) of the non-calibrated sensor response, and comparable statistical uncertainty.

  9. Integration of an interferometric IR absorber into an epoxy membrane based CO2 detector

    NASA Astrophysics Data System (ADS)

    Ashraf, S.; Mattsson, C. G.; Thungström, G.; Rödjegård, H.

    2014-05-01

    Measurements of carbon dioxide levels in the environment are commonly performed by using non-dispersive infrared technology (NDIR). Thermopile detectors are often used in NDIR systems because of their non-cooling advantages. The infrared absorber has a major influence on the detector responsivity. In this paper, the fabrication of a SU-8 epoxy membrane based Al/Bi thermopile detector and the integration of an interferometric infrared absorber structure of wavelength around 4 μm into the detector is reported. The membrane of thermopile detector has been utilized as a dielectric medium in an interferometric absorption structure. By doing so, a reduction in both thermal conductance and capacitance is achieved. In the fabrication of the thermopile, metal evaporation and lift off process had been used for the deposition of serially interconnected Al/Bi thermocouples. Serial resistance of fabricated thermopile was measured as 220 kΩ. The response of fabricated thermopile detector was measured using a visible to infrared source of radiation flux 3.23 mW mm-2. The radiation incident on the detector was limited using a band pass filter of wavelength 4.26 μm in front of the detector. A responsivity of 27.86 V mm2 W-1 at room temperature was achieved using this setup. The fabricated detector was compared to a reference detector with a broad band absorber. From the comparison it was concluded that the integrated interferometric absorber is functioning correctly.

  10. Approach for Self-Calibrating CO2 Measurements with Linear Membrane-Based Gas Sensors

    PubMed Central

    Lazik, Detlef; Sood, Pramit

    2016-01-01

    Linear membrane-based gas sensors that can be advantageously applied for the measurement of a single gas component in large heterogeneous systems, e.g., for representative determination of CO2 in the subsurface, can be designed depending on the properties of the observation object. A resulting disadvantage is that the permeation-based sensor response depends on operating conditions, the individual site-adapted sensor geometry, the membrane material, and the target gas component. Therefore, calibration is needed, especially of the slope, which could change over several orders of magnitude. A calibration-free approach based on an internal gas standard is developed to overcome the multi-criterial slope dependency. This results in a normalization of sensor response and enables the sensor to assess the significance of measurement. The approach was proofed on the example of CO2 analysis in dry air with tubular PDMS membranes for various CO2 concentrations of an internal standard. Negligible temperature dependency was found within an 18 K range. The transformation behavior of the measurement signal and the influence of concentration variations of the internal standard on the measurement signal were shown. Offsets that were adjusted based on the stated theory for the given measurement conditions and material data from the literature were in agreement with the experimentally determined offsets. A measurement comparison with an NDIR reference sensor shows an unexpectedly low bias (<1%) of the non-calibrated sensor response, and comparable statistical uncertainty. PMID:27869656

  11. Microfabrication of membrane-based devices by HARSE and combined HARSE/wet etching

    SciTech Connect

    Manginell, R.P.; Frye-Mason, G.C.; Schubert, W.K.; Shul, R.J.; Willison, C.G.

    1998-08-01

    Deep-reactive ion etching (DRIE) of silicon, also known as high-aspect-ratio silicon etching (HARSE), is distinguished by fast etch rates ({approximately}3 {micro}m/min), crystal orientation independence, anisotropy, vertical sidewall profiles and CMOS compatibility. By using through-wafer HARSE and stopping on a dielectric film placed on the opposite side of the wafer, freestanding dielectric membranes were produced. Dielectric membrane-based sensors and actuators fabricated in this way include microhotplates, flow sensors, valves and magnetically-actuated flexural plate wave (FPW) devices. Unfortunately, low-stress silicon nitride, a common membrane material, has an appreciable DRI etch rate. To overcome this problem HARSE can be followed by a brief wet chemical etch. This approach has been demonstrated using KOH or HF/Nitric/Acetic etchants, both of which have significantly smaller etch rates on silicon nitride than does DRIE. Composite membranes consisting of silicon dioxide and silicon nitride layers are also under evaluation due to the higher DRIE selectivity to silicon dioxide.

  12. Modelling heat and mass transfer in a membrane-based air-to-air enthalpy exchanger

    NASA Astrophysics Data System (ADS)

    Dugaria, S.; Moro, L.; Del, D., Col

    2015-11-01

    The diffusion of total energy recovery systems could lead to a significant reduction in the energy demand for building air-conditioning. With these devices, sensible heat and humidity can be recovered in winter from the exhaust airstream, while, in summer, the incoming air stream can be cooled and dehumidified by transferring the excess heat and moisture to the exhaust air stream. Membrane based enthalpy exchangers are composed by different channels separated by semi-permeable membranes. The membrane allows moisture transfer under vapour pressure difference, or water concentration difference, between the two sides and, at the same time, it is ideally impermeable to air and other contaminants present in exhaust air. Heat transfer between the airstreams occurs through the membrane due to the temperature gradient. The aim of this work is to develop a detailed model of the coupled heat and mass transfer mechanisms through the membrane between the two airstreams. After a review of the most relevant models published in the scientific literature, the governing equations are presented and some simplifying assumptions are analysed and discussed. As a result, a steady-state, two-dimensional finite difference numerical model is setup. The developed model is able to predict temperature and humidity evolution inside the channels. Sensible and latent heat transfer rate, as well as moisture transfer rate, are determined. A sensitive analysis is conducted in order to determine the more influential parameters on the thermal and vapour transfer.

  13. Promising aquivion composite membranes based on fluoroalkyl zirconium phosphate for fuel cell applications.

    PubMed

    Donnadio, Anna; Pica, Monica; Subianto, Surya; Jones, Deborah J; Cojocaru, Paula; Casciola, Mario

    2014-08-01

    Layered zirconium phosphate (ZP) that bears fluorinated alkyl chains bonded covalently to the layers (ZPR) was used as a nanofiller in membranes based on a short-side-chain perfluorosulfonic acid (PFSA) to mechanically reinforce the PFSA hydrophobic component. Compared to the pristine PFSA, membranes with a ZPR loading up to 30 wt% show enhanced mechanical properties, and the largest improvement of elastic modulus (E) and yield stress (σY ) are observed for the 10 wt% ZPR membrane: ΔE/E up to 90% and ΔσY /σY up 70% at 70°C and 80% relative humidity (RH). In the RH range 50-95%, the in-plane conductivity of the composite membranes reaches 0.43 S cm(-1) for 10 wt% ZPR at 110°C and is on average 30% higher than the conductivity of the pristine PFSA. The 10 wt % ZPR membrane is as hydrated as the neat PFSA membrane at 50% RH but becomes progressively less hydrated with increasing RH both at 80 and 110°C. The fuel cell performance of this membrane, at 80°C and 30% RH, is better than that of the unmodified PFSA.

  14. Sequential Vapor Infiltration Treatment Enhances the Ionic Current Rectification Performance of Composite Membranes Based on Mesoporous Silica Confined in Anodic Alumina.

    PubMed

    Liang, Yanyan; Liu, Zhengping

    2016-12-20

    Ionic current rectification of nanofluidic diode membranes has been studied widely in recent years because it is analogous to the functionality of biological ion channels in principle. We report a new method to fabricate ionic current rectification membranes based on mesoporous silica confined in anodic aluminum oxide (AAO) membranes. Two types of mesostructured silica nanocomposites, hexagonal structure and nanoparticle stacked structure, were used to asymmetrically fill nanochannels of AAO membranes by a vapor-phase synthesis (VPS) method with aspiration approach and were further modified via sequence vapor infiltration (SVI) treatment. The ionic current measurements indicated that SVI treatment can modulate the asymmetric ionic transport in prepared membranes, which exhibited clear ionic current rectification phenomenon under optimal conditions. The ionic current rectifying behavior is derived from the asymmetry of surface conformations, silica species components, and hydrophobic wettability, which are created by the asymmetrical filling type, silica depositions on the heterogeneous membranes, and the condensation of silanol groups. This article provides a considerable strategy to fabricate composite membranes with obvious ionic current rectification performance via the cooperation of the VPS method and SVI treatment and opens up the potential of mesoporous silica confined in AAO membranes to mimic fluid transport in biological processes.

  15. Solubility and Phase Behavior of CL20 in Supercritical Fluids

    DTIC Science & Technology

    2006-09-01

    the system was modeled in FORTRAN computer language with a cubic equation of state such as Peng - Robinson Equation of State (Peng and Robinson 1976...Soave or the Peng Robin- son equations. The Peng - Robinson equation is used in this work. The Peng - Robinson equation for a mixture is (Modell and Reid...parameters. For the Peng - Robinson equation of state, these mix- ture parameters are evaluated from mixing rules where the pure component analogues

  16. Drilling fluids and thinners therefor

    SciTech Connect

    Allison, G.M. III

    1986-10-21

    This patent describes an aqueous drilling fluid comprising water, finely divided solids and a first agent and a second agent. The first agent comprises a sulfoalkylated tannin containing no complexing heavy metal. The second agent comprises at least one at least partly water-soluble metal compound comprising tin. The weight ratio of the first agent to the second agent is in the range from about 100;1 to about 1:1.

  17. Paper membrane-based SERS platform for the determination of glucose in blood samples.

    PubMed

    Torul, Hilal; Çiftçi, Hakan; Çetin, Demet; Suludere, Zekiye; Boyacı, Ismail Hakkı; Tamer, Uğur

    2015-11-01

    In this report, we present a paper membrane-based surface-enhanced Raman scattering (SERS) platform for the determination of blood glucose level using a nitrocellulose membrane as substrate paper, and the microfluidic channel was simply constructed by wax-printing method. The rod-shaped gold nanorod particles were modified with 4-mercaptophenylboronic acid (4-MBA) and 1-decanethiol (1-DT) molecules and used as embedded SERS probe for paper-based microfluidics. The SERS measurement area was simply constructed by dropping gold nanoparticles on nitrocellulose membrane, and the blood sample was dropped on the membrane hydrophilic channel. While the blood cells and proteins were held on nitrocellulose membrane, glucose molecules were moved through the channel toward the SERS measurement area. Scanning electron microscopy (SEM) was used to confirm the effective separation of blood matrix, and total analysis is completed in 5 min. In SERS measurements, the intensity of the band at 1070 cm(-1) which is attributed to B-OH vibration decreased depending on the rise in glucose concentration in the blood sample. The glucose concentration was found to be 5.43 ± 0.51 mM in the reference blood sample by using a calibration equation, and the certified value for glucose was 6.17 ± 0.11 mM. The recovery of the glucose in the reference blood sample was about 88 %. According to these results, the developed paper-based microfluidic SERS platform has been found to be suitable for use for the detection of glucose in blood samples without any pretreatment procedure. We believe that paper-based microfluidic systems may provide a wide field of usage for paper-based applications.

  18. A membrane-based purification process for cell culture-derived influenza A virus.

    PubMed

    Weigel, Thomas; Solomaier, Thomas; Wehmeyer, Sebastian; Peuker, Alessa; Wolff, Michael W; Reichl, Udo

    2016-02-20

    A simple membrane-based purification process for cell culture-derived influenza virus was established that relies on only two chromatographic unit operations to achieve the contamination limits required according to regulatory authorities. After clarification and concentration, a pseudo-affinity membrane adsorber (sulfated cellulose, SCMA) was applied for virus capture. The subsequent polishing step consisted of a salt-tolerant anion exchange membrane adsorber (STMA) to bind residual DNA. For the presented process neither a buffer exchange step nor a nuclease step for further DNA digestion were required. As a starting point, a two-salt strategy (including a polyvalent ion) was employed to screen STMA conditions in a 96-well plate format. After optimization on chromatographic laboratory scale, the virus recovery was up to 97% with a residual DNA level below 0.82%. In addition, the STMA was characterized regarding its dynamic binding capacity and the impact of flow rate on yields and contamination levels. Overall, the total virus yield for influenza virus A/PR/8/34 (H1/N1) of this two-step membrane process was 75%, while the protein and the DNA contamination level could be reduced to 24% and at least 0.5%, respectively. With 19.8μg protein and 1.2ng DNA per monovalent dose, this purity level complies with the limits of the European Pharmacopeia for cell culture-derived vaccines for human use. Overall, the presented downstream process might serve as a generic and economic platform technology for production of cell culture-derived viruses and viral vectors.

  19. A large format membrane-based x-ray mask for microfluidic chip fabrication

    NASA Astrophysics Data System (ADS)

    Wang, Lin; Zhang, Min; Desta, Yohannes; Melzak, J.; Wu, C. H.; Peng, Zhengchun

    2006-02-01

    X-ray lithography is a very good option for the fabrication of micro-devices especially when high aspect ratio patterns are required. Membrane-based x-ray masks are commonly used for high-resolution x-ray lithography. A thin layer of silicon nitride (Si3N4) or silicon carbide (SiC) film (1-2 µm) is normally used as the membrane material for x-ray mask fabrication (Wells G M, Reilly M, Nachman R, Cerrina F, El-Khakani M A and Chaker M 1993 Mater. Res. Soc. Conf. Proc. 306 81-9 Shoki T, Nagasawa H, Kosuga H, Yamaguchi Y, Annaka N, Amemiya I and Nagarekawa O 1993 SPIE Proc. 1924 450-6). The freestanding membrane window of an x-ray mask, which defines the exposing area of the x-ray mask, can be obtained by etching a pre-defined area on a silicon wafer from the backside (Wang L, Desta Y, Fettig R K, Goettert J, Hein H, Jakobs P and Chulz J 2004 J. Micromech. Microeng. 14 722-6). Usually, the window size of an x-ray mask is around 20 × 20 mm because of the low tensile stress of the membrane (10-100 MPa), and the larger window dimension of an x-ray mask may cause the deformation of membranes and lower the mask quality. However, x-ray masks with larger windows are preferred for micro-device fabrication in order to increase the productivity. We analyzed the factors which influence the flatness of large format x-ray masks and fabricated x-ray masks with a window size of 55 × 55 mm and 46 × 65 mm on 1 µm thick membranes by increasing the tensile stress of the membranes (>300 MPa) and optimizing the stress of the absorber layer. The large format x-ray mask was successfully applied for the fabrication of microfluidic chips.

  20. Differential membrane-based nanocalorimeter for high-resolution measurements of low-temperature specific heat.

    PubMed

    Tagliati, S; Krasnov, V M; Rydh, A

    2012-05-01

    A differential, membrane-based nanocalorimeter for general specific heat studies of very small samples, ranging from 0.5 mg to sub-μg in mass, is described. The calorimeter operates over the temperature range from above room temperature down to 0.5 K. It consists of a pair of cells, each of which is a stack of heaters and thermometer in the center of a silicon nitride membrane, in total giving a background heat capacity less than 100 nJ/K at 300 K, decreasing to 10 pJ/K at 1 K. The device has several distinctive features: (i) The resistive thermometer, made of a Ge(1 - x)Au(x) alloy, displays a high dimensionless sensitivity ∣dlnR∕dlnT∣ ≳ 1 over the entire temperature range. (ii) The sample is placed in direct contact with the thermometer, which is allowed to self-heat. The thermometer can thus be operated at high dc current to increase the resolution. (iii) Data are acquired with a set of eight synchronized lock-in amplifiers measuring dc, 1st and 2nd harmonic signals of heaters and thermometer. This gives high resolution and allows continuous output adjustments without additional noise. (iv) Absolute accuracy is achieved via a variable-frequency-fixed-phase technique in which the measurement frequency is automatically adjusted during the measurements to account for the temperature variation of the sample heat capacity and the device thermal conductance. The performance of the calorimeter is illustrated by studying the heat capacity of a small Au sample and the specific heat of a 2.6 μg piece of superconducting Pb in various magnetic fields.

  1. Membrane-based, sedimentation-assisted plasma separator for point-of-care applications.

    PubMed

    Liu, Changchun; Mauk, Michael; Gross, Robert; Bushman, Frederic D; Edelstein, Paul H; Collman, Ronald G; Bau, Haim H

    2013-11-05

    Often, high-sensitivity, point-of-care (POC) clinical tests, such as HIV viral load, require large volumes of plasma. Although centrifuges are ubiquitously used in clinical laboratories to separate plasma from whole blood, centrifugation is generally inappropriate for on-site testing. Suitable alternatives are not readily available to separate the relatively large volumes of plasma from milliliters of blood that may be needed to meet stringent limit-of-detection specifications for low-abundance target molecules. We report on a simple-to-use, low-cost, pump-free, membrane-based, sedimentation-assisted plasma separator capable of separating a relatively large volume of plasma from undiluted whole blood within minutes. This plasma separator consists of an asymmetric, porous, polysulfone membrane housed in a disposable chamber. The separation process takes advantage of both gravitational sedimentation of blood cells and size exclusion-based filtration. The plasma separator demonstrated a "blood in-plasma out" capability, consistently extracting 275 ± 33.5 μL of plasma from 1.8 mL of undiluted whole blood within less than 7 min. The device was used to separate plasma laden with HIV viruses from HIV virus-spiked whole blood with recovery efficiencies of 95.5% ± 3.5%, 88.0% ± 9.5%, and 81.5% ± 12.1% for viral loads of 35,000, 3500, and 350 copies/mL, respectively. The separation process is self-terminating to prevent excessive hemolysis. The HIV-laden plasma was then injected into our custom-made microfluidic chip for nucleic acid testing and was successfully subjected to reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP), demonstrating that the plasma is sufficiently pure to support high-efficiency nucleic acid amplification.

  2. Potentiometric Response Characteristics of Membrane-Based Cs + -Selective Electrodes Containing Ionophore-Functionalized Polymeric Microspheres

    DOE PAGES

    Peper, Shane; Gonczy, Chad

    2011-01-01

    Csmore » + -selective solvent polymeric membrane-based ion-selective electrodes (ISEs) were developed by doping ethylene glycol-functionalized cross-linked polystyrene microspheres (P-EG) into a plasticized poly(vinyl chloride) (PVC) matrix containing sodium tetrakis-(3,5-bis(trifluoromethyl)phenyl) borate (TFPB) as the ion exchanger. A systematic study examining the effects of the membrane plasticizers bis(2-ethylhexyl) sebacate (DOS), 2-nitrophenyl octyl ether (NPOE), and 2-fluorophenyl nitrophenyl ether (FPNPE) on the potentiometric response and selectivity of the corresponding electrodes was performed. Under certain conditions, P-EG-based ion-selective electrodes (ISEs) containing TFPB and plasticized with NPOE exhibited a super-Nernstian response between 1 × 10 − 3 and 1 × 10 − 4  M+ , a response characteristic not observed in analogous membranes plasticized with either DOS or FPNPE. Additionally, the performance of P-EG-based ISEs was compared to electrodes based on two mobile ionophores, a neutral lipophilic ethylene glycol derivative (ethylene glycol monooctadecyl ether (U-EG)) and a charged metallacarborane ionophore, sodium bis(dicarbollyl)cobaltate(III) (CC). In general, P-EG-based electrodes plasticized with FPNPE yielded the best performance, with a linear range from 10 -1 –10 -5  M+ , a conventional lower detection limit of 8.1 × 10 − 6  M+ , and a response slope of 57.7 mV/decade. The pH response of P-EG ISEs containing TFPB was evaluated for membranes plasticized with either NPOE or FPNPE. In both cases, the electrodes remained stable throughout the pH range 3–12, with only slight proton interference observed below pH 3.« less

  3. Water soluble laser dyes

    DOEpatents

    Hammond, Peter R.; Feeman, James F.; Field, George F.

    1998-01-01

    Novel water soluble dyes of the formula I are provided ##STR1## wherein R.sup.1 and R.sup.4 are alkyl of 1 to 4 carbon atoms or hydrogen; or R.sup.1 -R.sup.2 or R.sup.2 -R.sup.4 form part of aliphatic heterocyclic rings; R.sup.2 is hydrogen or joined with R.sup.1 or R.sup.4 as described above; R.sup.3 is --(CH.sub.2).sub.m --SO.sub.3.sup.-, where m is 1 to 6; X is N, CH or ##STR2## where Y is 2 --SO.sub.3.sup.- ; Z is 3, 4, 5 or 6 --SO.sub.3.sup.-. The novel dyes are particularly useful as the active media in water solution dye lasers.

  4. Water soluble laser dyes

    DOEpatents

    Hammond, P.R.; Feeman, J.F.; Field, G.F.

    1998-08-11

    Novel water soluble dyes of the formula 1 are provided by the formula described in the paper wherein R{sup 1} and R{sup 4} are alkyl of 1 to 4 carbon atoms or hydrogen; or R{sup 1}--R{sup 2} or R{sup 2}--R{sup 4} form part of aliphatic heterocyclic rings; R{sup 2} is hydrogen or joined with R{sup 1} or R{sup 4} as described above; R{sup 3} is --(CH{sub 2}){sub m}--SO{sub 3}{sup {minus}}, where m is 1 to 6; X is N, CH or formula 2 given in paper where Y is 2 --SO{sub 3}{sup {minus}} ; Z is 3, 4, 5 or 6 --SO{sub 3}{sup {minus}}. The novel dyes are particularly useful as the active media in water solution dye lasers.

  5. The Solubility of Nitrogen and Air in Liquids

    NASA Astrophysics Data System (ADS)

    Battino, Rubin; Rettich, Timothy R.; Tominaga, Toshihiro

    1984-04-01

    This review covers the solubility of nitrogen and air in liquids as a function of temperature and pressure. Solubility data for individual systems were critically evaluated. Recommended or tentative values are presented as smoothing equations and/or in tabular form. Trends in homologous series or related solvents are discussed. Data for the n-alkanes were smoothed with respect to temperature, pressure, and carbon number. Liquids include: water; heavy water; seawater; aqueous salt solutions; mixed solvents; hydrocarbons; organic compounds containing oxygen, halogen, sulfur, nitrogen, or silicon; olive oil; various biological fluids; H2S; SO2; NH3; CO2; nitrogen oxides; and several halogen and boron containing inorganic solvents.

  6. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, M.; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Lauriie, S.; Garcia, K.; Sargsyan, A.; Martin, D.; Ribeiro, L.; Lui, J.; Macias, B.; Arbeille, P.; Danielson, R.; Chang, D.; Johnston, S.; Ploutz-Snyder, R.; Smith, S.

    2016-01-01

    NASA is focusing on long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low-Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but more than 50% of ISS astronauts experienced more profound, chronic changes with objective structural and functional findings such as papilledema and choroidal folds. Globe flattening, optic nerve sheath dilation, and optic nerve tortuosity also are apparent. This pattern is referred to as the visual impairment and intracranial pressure (VIIP) syndrome. VIIP signs and symptoms, as well as postflight lumbar puncture data, suggest that elevated intracranial pressure (ICP) may be associated with the spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight, and to correlate these findings with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as the VIIP-related effects of those shifts, is predicted by the crewmember's preflight conditions and responses to acute hemodynamic manipulations (such as head-down tilt). Lastly, we will evaluate the patterns of fluid distribution in ISS astronauts during acute reversal of fluid shifts through application of lower body negative pressure (LBNP) interventions to characterize and explain general and individual responses. METHODS: We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the Figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, calcaneus tissue thickness (by

  7. Wellbore fluid

    SciTech Connect

    Dorsey, D.L.; Corley, W.T.

    1983-12-27

    A clay-based or clay-free aqueous thixotropic wellbore fluid having improved fluid loss control, desirable flow characteristics and low shale sensitivity for use in drilling a well comprising water or a brine base including an effective amount of an additive comprising a crosslinked potato starch, a heteropolysaccharide derived from a carbohydrate by bacteria of the genus Xanthomonas, and hydroxyethylcellulose or carboxymethylcellulose, is disclosed. This drilling fluid has been found to be nondamaging to the formations through which the well is drilled.

  8. Pure Phase Solubility Limits: LANL

    SciTech Connect

    C. Stockman

    2001-01-26

    The natural and engineered system at Yucca Mountain (YM) defines the site-specific conditions under which one must determine to what extent the engineered and the natural geochemical barriers will prevent the release of radioactive material from the repository. Most important mechanisms for retention or enhancement of radionuclide transport include precipitation or co-precipitation of radionuclide-bearing solid phases (solubility limits), complexation in solution, sorption onto surfaces, colloid formation, and diffusion. There may be many scenarios that could affect the near-field environment, creating chemical conditions more aggressive than the conditions presented by the unperturbed system (such as pH changes beyond the range of 6 to 9 or significant changes in the ionic strength of infiltrated waters). For an extended period of time, the near-field water composition may be quite different and more extreme in pH, ionic strength, and CO{sub 2} partial pressure (or carbonate concentration) than waters at some distance from the repository. Reducing conditions, high pH (up to 11), and low carbonate concentration may be present in the near-field after reaction of infiltrating groundwater with engineered barrier systems, such as cementitious materials. In the far-field, conditions are controlled by the rock-mass buffer providing a near-neutral, oxidizing, low-ionic-strength environment that controls radionuclide solubility limits and sorption capacities. There is the need for characterization of variable chemical conditions that affect solubility, speciation, and sorption reactions. Modeling of the groundwater chemistry is required and leads to an understanding of solubility and speciation of the important radionuclides. Because experimental studies cannot be performed under the numerous potential chemical conditions, solubility limitations must rely on geochemical modeling of the radionuclide's chemistry. Fundamental thermodynamic properties, such as solubility

  9. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, M. B.; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Laurie, S.; Garcia, K.; Sargsyan, A.; Martin, D.; Lui, J.; Macias, B.; Arbeille, P.; Danielson, R.; Chang, D.; Gunga, H.; Johnston, S.; Westby, C.; Ribeiro, L.; Ploutz-Snyder, R.; Smith, S.

    2015-01-01

    INTRODUCTION: Mechanisms responsible for the ocular structural and functional changes that characterize the visual impairment and intracranial pressure (ICP) syndrome (VIIP) are unclear, but hypothesized to be secondary to the cephalad fluid shift experienced in spaceflight. This study will relate the fluid distribution and compartmentalization associated with long-duration spaceflight with VIIP symptoms. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as the VIIP-related effects of those shifts, can be predicted preflight with acute hemodynamic manipulations, and also if lower body negative pressure (LBNP) can reverse the VIIP effects. METHODS: Physiologic variables will be examined pre-, in- and post-flight in 10 International Space Station crewmembers including: fluid compartmentalization (D2O and NaBr dilution); interstitial tissue thickness (ultrasound); vascular dimensions and dynamics (ultrasound and MRI (including cerebrospinal fluid pulsatility)); ocular measures (optical coherence tomography, intraocular pressure, ultrasound); and ICP measures (tympanic membrane displacement, otoacoustic emissions). Pre- and post-flight measures will be assessed while upright, supine and during 15 deg head-down tilt (HDT). In-flight measures will occur early and late during 6 or 12 month missions. LBNP will be evaluated as a countermeasure during HDT and during spaceflight. RESULTS: The first two crewmembers are in the preflight testing phase. Preliminary results characterize the acute fluid shifts experienced from upright, to supine and HDT postures (increased stroke volume, jugular dimensions and measures of ICP) which are reversed with 25 millimeters Hg LBNP. DISCUSSION: Initial results indicate that acute cephalad fluid shifts may be related to VIIP symptoms, but also may be reversible by LBNP. The effect of a chronic fluid shift has yet to be evaluated. Learning Objectives: Current spaceflight VIIP research is described

  10. Electrorheological fluids

    SciTech Connect

    Halsey, T.C.; Martin, J.E.

    1993-10-01

    An electrorheological fluid is a substance whose form changes in the presence of electric fields. Depending on the strength of the field to which it is subjected, an electrorheological fluid can run freely like water, ooze like honey or solidify like gelatin. Indeed, the substance can switch from ne state to another within a few milliseconds. Electrorheological fluids are easy to make; they consist of microscopic particles suspended in an insulating liquid. Yet they are not ready for most commercial applications. They tend to suffer from a number of problems, including structural weakness as solids, abrasiveness as liquids and chemical breakdown, especially at high temperatures. Automotive engineers could imagine, for instance, constructing an electrorheological clutch. It was also hoped that electrorheological fluids would lead to valveless hydraulic systems, in which solidifying fluid would shut off flow through a thin section of pipe. Electrorheological fluids also offer the possibility of a shock absorber that provides response times of milliseconds and does not require mechanical adjustments. 3 refs.

  11. Detection of weak-binding sugar activity using membrane-based carbohydrates.

    PubMed

    Yamamoto, Kazuo; Kawasaki, Norihito

    2010-01-01

    Protein-sugar interactions underlie many biological events. Although protein-sugar interactions are weak, they are regulated in physiological conditions including clustering, association with other proteins, pH condition, and so on. The elucidation of the precise specificities of sugar-binding proteins is essential for understanding their biological functions. To detect the weak-binding activity of carbohydrate-binding proteins to sugar ligands, we studied lectin tetramer binding to cell-surface carbohydrates by flow cytometry. Tetramerization of lectins enhanced their avidity for sugar ligands, and sugar chains displayed on the cell surfaces were easily accessible to such soluble lectins. In this chapter, we describe methods to (1) prepare biotinylated soluble lectin, (2) obtain R-phycoerythrin-labeled lectin tetramer, and (3) measure tetramer binding to various lectin-resistant cell lines or cells treated with sugar-processing inhibitors. This approach enabled us to detect the weak sugar-binding activity of lectins (K(a) approximately 10(4)M(-1)), especially those from animals, and also to elucidate their specificity for sugar ligands.

  12. The Ksp-Solubility Conundrum.

    ERIC Educational Resources Information Center

    Clark, Roy W.; Bonicamp, Judith M.

    1998-01-01

    Argues that there are only a few cases in which solubility and Ksp are related in a simple way. States that illustrations of the solubility product principle for one-to-one salts are adequate for students. Contains 23 references. (DDR)

  13. "Ready-to-use" hollow nanofiber membrane-based glucose testing strips.

    PubMed

    Ji, Xiaoyuan; Su, Zhiguo; Wang, Ping; Ma, Guanghui; Zhang, Songping

    2014-12-21

    A novel "ready-to-use" glucose test strip based on a polyurethane hollow nanofiber membrane was fabricated through facile co-axial electrospinning. By utilizing glucose oxidase and horseradish peroxidase in the core-phase solution, and a chromogenic agent either in the core solution (in which case 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) was used) or in the shell-phase solution (in which case o-dianisidine was used) for co-axial electrospinning, in situ co-encapsulation of the two enzymes within the hollow nano-chamber and incorporation of chromogenic agents either inside the nano-chamber or in the shell of the hollow nanofibers was realized. Such unique "all-in-one" feature enabled the prepared hollow nanofiber membrane-based test strips to be applied either as colorimetric sensors in solution or as an optical biosensor operated in the "dip-and-read" mode. When used as a colorimetric biosensor in solution, the test strip with o-dianisidine as chromogenic agent shows an excellent linear response range between 0.01 mM to 20 mM and a high apparent lumped activity recovery of 62.1% as compared to the reaction rate of the free bi-enzyme system. While the activity recovery of the test strip with ABTS as chromogenic agent is only 18.0%, and the test strip is found to be unstable due to spontaneous-oxidation of the ABTS. The o-dianisidine test strip was also applied as an optical biosensor, visible rufous color was quickly developed on the surface of the membrane upon dropping 10 μL of glucose sample, and an excellent correlation between differential diffusive reflectance of the test strip at 440 nm and glucose concentration was obtained in the range of 0.5-50 mM. The test strips also exhibited excellent long-term storage stability with a half-life at 25 °C as long as four months.

  14. A colorimetric reaction to quantify fluid mixing

    NASA Astrophysics Data System (ADS)

    Oates, Peter M.; Harvey, Charles F.

    2006-11-01

    We found the colorimetric reaction of Tiron (1,2-dihydroxybenzene-3,5-disulfonic acid) and molybdate suitable for optical quantification of chemical reaction during fluid-fluid mixing in laboratory chambers. This reaction consists of two colorless reagents that mix to rapidly form colored, stable, soluble products. These products can be digitally imaged and quantified using light absorbance to study fluid-fluid mixing. Here we provide a model and equilibrium constants for the relevant complexation reactions. We also provide methods for relating light absorbance to product concentrations. Practical implementation issues of this reaction are discussed and an example of imaged absorbances for fluid-fluid mixing in heterogeneous porous media is given.

  15. Recombinant soluble adenovirus receptor

    DOEpatents

    Freimuth, Paul I.

    2002-01-01

    Disclosed are isolated polypeptides from human CAR (coxsackievirus and adenovirus receptor) protein which bind adenovirus. Specifically disclosed are amino acid sequences which corresponds to adenovirus binding domain D1 and the entire extracellular domain of human CAR protein comprising D1 and D2. In other aspects, the disclosure relates to nucleic acid sequences encoding these domains as well as expression vectors which encode the domains and bacterial cells containing such vectors. Also disclosed is an isolated fusion protein comprised of the D1 polypeptide sequence fused to a polypeptide sequence which facilitates folding of D1 into a functional, soluble domain when expressed in bacteria. The functional D1 domain finds application for example in a therapeutic method for treating a patient infected with a virus which binds to D1, and also in a method for identifying an antiviral compound which interferes with viral attachment. Also included is a method for specifically targeting a cell for infection by a virus which binds to D1.

  16. Fluid Management System (FMS) fluid systems overview

    NASA Technical Reports Server (NTRS)

    Baird, R. S.

    1990-01-01

    Viewgraphs on fluid management system (FMS) fluid systems overview are presented. Topics addressed include: fluid management system description including system requirements (integrated nitrogen system, integrated water system, and integrated waste gas system) and physical description; and fluid management system evolution.

  17. Numerical simulation of drop and bubble dynamics with soluble surfactant

    NASA Astrophysics Data System (ADS)

    Wang, Qiming; Siegel, Michael; Booty, Michael R.

    2014-05-01

    Numerical computations are presented to study the effect of soluble surfactant on the deformation and breakup of an axisymmetric drop or bubble stretched by an imposed linear strain flow in a viscous fluid. At the high values of bulk Peclet number Pe in typical fluid-surfactant systems, there is a thin transition layer near the interface in which the surfactant concentration varies rapidly. The large surfactant gradients are resolved using a fast and accurate "hybrid" numerical method that incorporates a separate, singular perturbation analysis of the dynamics in the transition layer into a full numerical solution of the free boundary problem. The method is used to investigate the dependence of drop deformation on parameters that characterize surfactant solubility. We also compute resolved examples of tipstreaming, and investigate its dependence on parameters such as flow rate and bulk surfactant concentration.

  18. Supercritical fluid thermodynamics for coal processing

    SciTech Connect

    van Swol, F. . Dept. of Chemical Engineering); Eckert, C.A. . School of Chemical Engineering)

    1990-01-01

    Because of their unusual solvating and mass transfer properties, supercritical fluids show potential for a variety of coal processing applications. We have established a database of coal model compound equilibria; to add to this database, we have developed and are testing methods of rapidly measuring cosolvent effects on solubility. In addition, we have used fluorescence spectroscopy to study the nature of cosolvent effects on molecular level. The solubility and spectroscopic measurements are being used to guide the development of an equation of state that includes both physical and chemical interactions. The equation of state will be used to predict solubility behavior to systems can be designed for the processing of coal with supercritical fluids. 8 figs.

  19. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, Michael; Hargens, A.; Dulchavsky, S.; Ebert, D.; Lee, S.; Sargsyan, A.; Martin, D.; Lui, J.; Macias, B.; Arbeille, P.; Platts, S.

    2014-01-01

    NASA is focusing on long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but more than 30% of ISS astronauts experience more profound, chronic changes with objective structural and functional findings such as papilledema and choroidal folds. Globe flattening, optic nerve sheath dilation, and optic nerve tortuosity also are apparent. This pattern is referred to as the visual impairment and intracranial pressure (VIIP) syndrome. VIIP signs and symptoms, as well as postflight lumbar puncture data, suggest that elevated intracranial pressure (ICP) may be associated with the space flight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration space flight, and to correlate these findings with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during space flight, as well as the VIIP-related effects of those shifts, is predicted by the crewmember's pre-flight condition and responses to acute hemodynamic manipulations (such as head-down tilt). Lastly, we will evaluate the patterns of fluid distribution in ISS astronauts during acute reversal of fluid shifts through application of lower body negative pressure (LBNP) interventions to characterize and explain general and individual responses. We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the Figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, calcaneus tissue thickness (by ultrasound

  20. Concomitant intake of alcohol may increase the absorption of poorly soluble drugs.

    PubMed

    Fagerberg, Jonas H; Sjögren, Erik; Bergström, Christel A S

    2015-01-25

    Ethanol can increase the solubility of poorly soluble and hence present a higher drug concentration in the gastrointestinal tract. This may produce a faster and more effective absorption resulting in variable and/or high drug plasma concentrations, both of which can lead to adverse drug reactions. In this work we therefore studied the solubility and absorption effects of nine diverse compounds when ethanol was present. The apparent solubility was measured using the μDiss Profiler Plus (pION, MA) in four media representing gastric conditions with and without ethanol. The solubility results were combined with in-house data on solubility in intestinal fluids (with and without ethanol) and pharmacokinetic parameters extracted from the literature and used as input in compartmental absorption simulations using the software GI-Sim. Apparent solubility increased more than 7-fold for non-ionized compounds in simulated gastric fluid containing 20% ethanol. Compounds with weak base functions (cinnarizine, dipyridamole and terfenadine) were completely ionized at the studied gastric pH and their solubility was therefore unaffected by ethanol. Compounds with low solubility in intestinal media and a pronounced solubility increase due to ethanol in the upper gastric compartments showed an increased absorption in the simulations. The rate of absorption of the acidic compounds indomethacin and indoprofen was slightly increased but the extent of absorption was unaffected as the complete doses were readily absorbed even without ethanol. This was likely due to a high apparent solubility in the intestinal compartment where the weak acids are ionized. The absorption of the studied non-ionizable compounds increased when ethanol was present in the gastric and intestinal media. These results indicate that concomitant intake of alcohol may significantly increase the solubility and hence, the plasma concentration for non-ionizable, lipophilic compounds with the potential of adverse drug

  1. Understanding Solubility through Excel Spreadsheets

    NASA Astrophysics Data System (ADS)

    Brown, Pamela

    2001-02-01

    This article describes assignments related to the solubility of inorganic salts that can be given in an introductory general chemistry course. Le Châtelier's principle, solubility, unit conversion, and thermodynamics are tied together to calculate heats of solution by two methods: heats of formation and an application of the van't Hoff equation. These assignments address the need for math, graphing, and computer skills in the chemical technology program by developing skill in the use of Microsoft Excel to prepare spreadsheets and graphs and to perform linear and nonlinear curve-fitting. Background information on the value of understanding and predicting solubility is provided.

  2. Phenylated Polyimides With Greater Solubility

    NASA Technical Reports Server (NTRS)

    Harris, Frank W.

    1991-01-01

    In experiments, 3,6-diphenylpyromellitic dianhydride monomer prepared and polymerized with several different diamines. Polyimides with pendent phenyl groups along polymer backbones considerably more soluble than PMDA-based materials. Increased solubility eases processing, providing increased potential use in variety of applications. Because most polymers soluble in organic solvents, usable in microelectronics applications. Excellent thermal stabilities and high transition temperatures make them ideally suited. Many polymers extremely rigid and useful as reinforcing polymers in molecular composites. More flexible compositions useful as matrix resins in carbon-reinforced composites.

  3. Critical review of coupled flux formulations for clay membranes based on nonequilibrium thermodynamics.

    PubMed

    Malusis, Michael A; Shackelford, Charles D; Maneval, James E

    2012-09-01

    Extensive research conducted over the past several decades has indicated that semipermeable membrane behavior (i.e., the ability of a porous medium to restrict the passage of solutes) may have a significant influence on solute migration through a wide variety of clay-rich soils, including both natural clay formations (aquitards, aquicludes) and engineered clay barriers (e.g., landfill liners and vertical cutoff walls). Restricted solute migration through clay membranes generally has been described using coupled flux formulations based on nonequilibrium (irreversible) thermodynamics. However, these formulations have differed depending on the assumptions inherent in the theoretical development, resulting in some confusion regarding the applicability of the formulations. Accordingly, a critical review of coupled flux formulations for liquid, current, and solutes through a semipermeable clay membrane under isothermal conditions is undertaken with the goals of explicitly resolving differences among the formulations and illustrating the significance of the differences from theoretical and practical perspectives. Formulations based on single-solute systems (i.e., uncharged solute), single-salt systems, and general systems containing multiple cations or anions are presented. Also, expressions relating the phenomenological coefficients in the coupled flux equations to relevant soil properties (e.g., hydraulic conductivity and effective diffusion coefficient) are summarized for each system. A major difference in the formulations is shown to exist depending on whether counter diffusion or salt diffusion is assumed. This difference between counter and salt diffusion is shown to affect the interpretation of values for the effective diffusion coefficient in a clay membrane based on previously published experimental data. Solute transport theories based on both counter and salt diffusion then are used to re-evaluate previously published column test data for the same clay membrane

  4. Development and understanding of new membranes based on aromatic polymers and heterocycles for fuel cells

    NASA Astrophysics Data System (ADS)

    Li, Wen

    Direct methanol fuel cells (DMFC) are appealing as a power source for portable devices as they do not require recharging with an electrical outlet. However, the DMFC technology is confronted with the high crossover of methanol fuel from the anode to the cathode through the currently used Nafion membrane, which not only wastes the fuel but also poisons the cathode platinum catalyst. With an aim to overcome the problems encountered with the Nafion membrane, this dissertation focuses on the design and development of new polymeric membrane materials for DMFC and a fundamental understanding of their structure-property-performance relationships. Several polymeric blend membranes based on acid-base interactions between an aromatic acidic polymer such as sulfonated ploy(ether ether ketone) (SPEEK) and an aromatic basic polymer such as heterocycle tethered poly(sulfone) (PSf) have been explored. Various heterochylces like nitro-benzimidazole (NBIm), 1H-Perimidine (PImd), and 5-amino-benzotriazole (BTraz) have been tethered to PSf to understand the influence of pKa values and the size of the hetrocycles. The blend membranes show lower methanol crossover and better performance in DMFC than plain SPEEK due to an enhancement in proton conductivity through acid-base interactions and an insertion of the heterocycle side groups into the ionic clusters of SPEEK as indicated by small angle X-ray scattering and TEM data. The SPEEK/PSf-PImd blend membrane shows the lowest methanol crossover due to the larger size of the side groups, while the SPEEK/PSf-BTraz blend membrane shows the highest proton conductivity and maximum power density. To further investigate the methanol-blocking effect of the heterocycles, N,N'-Bis-(1H-benzimidazol-2-yl)-isophthalamide (BBImIP) having two amino-benzimidazole groups bonded to a phenyl ring has been incorporated into sulfonated polysulfone (SPSf) and SPEEK membranes. With two 2-amino-benzimidazole groups, which could greatly increase the proton

  5. The environmental applications and implications of nanotechnology in membrane-based separations for water treatment

    NASA Astrophysics Data System (ADS)

    Shan, Wenqian

    This dissertation presents results of three related projects focused on the applications of membrane separation technology to water treatment: 1) Experimental design and evaluation of polyelectrolyte multilayer films as regenerable membrane coatings with controllable surface properties; 2) Modeling of the interactions of nanoscale TiO2 and NOM molecules in aqueous solutions of environmentally relevant compositions; 3) Experimental design and preliminary testing of a membrane-based crossflow filtration hydrocyclone process for the separation of oil-in-water dispersions. Chapter 2 describes the design of polyelectrolyte multilayers as nanoscale membrane coatings and their application in nanofiltration of feed waters that contain suspended colloids and dissolved species. Layer-by-layer deposition of anionic and cationic polyelectrolytes was employed to prepare membrane coatings allowing for a fine control over their surface properties. This approach to membrane design also affords a possibility of regenerating coatings after they are fouled by colloids. This project demonstrated, for first time, the possibility of designing nanofiltration membranes with regenerable skin. Chapter 3 describes a study on the mechanisms of natural organic matter (NOM) adsorption onto the surface of titania nanoparticles. Titainia (TiO 2) is often used in the fabrication of ceramic membranes and understanding how NOM interacts with TiO2 can help to better predict ceramic membrane fouling by NOM-containing waters. The combined effect of pH and calcium on the interactions of nonozonated and ozonated NOM with nanoscale TiO 2 was investigated by applying extended Derjaguin --- Landau --- Verwey - Overbeek (XDLVO) modeling. XDLVO surface energy analysis predicted NOM adsorption onto TiO2 in the ozone-controlled regime but not in the calcium-controlled regime. In both regimes, short range NOM-NOM and NOM-TiO2 interactions were governed by acid-base and van der Waals forces, whereas the role of

  6. New composite membranes based on modified Nafion or Flemion for PEM fuel cell application

    NASA Astrophysics Data System (ADS)

    Tian, Huimin

    A new composite membrane based on Nafion or Flemion and Silicotungstic acid (STA) was fabricated using a simple solvent evaporation procedure. The optimum evaporation temperature and the amount of STA have been investigated. The evaporation of solvent can be divided into two steps during membrane preparation. Firstly, the solvent was evaporated at 70°C for two hours. Secondly, the evaporated membrane was kept in an vacuum oven at 135°C overnight. The optimum amount of STA in the casting electrolyte solution is in the range from 5 x 10-4 to 5 x 10-3 M. The obtained cast composite membranes exhibit good thermal and mechanical properties. Study of the ionic conductivity shows that the composite membrane with STA gives a higher ionic conductivity than that without STA. The conductivity of composite membrane increases with the increase of STA concentration. When the STA concentration in the 10mL casting electrolyte solution is 5 x 10-3M, the conductivities of the composite membranes can reach up to 0.120 ohm-1 · cm-1 for Nafion/STA membrane and 0.133 ohm -1 · cm-1 for Flemion/STA membrane. On the other hand, the water uptake measurement shows that the water content of the composite membrane with STA is higher than that of composite membrane without STA. Consequently, due to the high conductivity and the high hydrated abiliy of STA, ionic conductivity and water uptake of the composite membrane can be significantly improved by the addition of STA. The morphology of the composite membrane was studied using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results of AFM and SEM showed that the STA was uniformly dispersed in the Nafion and Flemion composite membranes. The structure of a composite membrane with STA has been studied by X-ray diffraction (XRD), the fourier transform infrared spectroscopy (FTIR), thermoanalysis and X-ray photoelectron spectroscopy (XPS). The results indicated that STA was successfully introduced into the structure of

  7. Fluid Shifts

    NASA Technical Reports Server (NTRS)

    Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.; Liu, J.; Macias, B.; Martin, D. S.; Minkoff, L.; Ploutz-Snyder, R.; Ribeiro, L. C.; Sargsyan, A.; Smith, S. M.

    2017-01-01

    Introduction. NASA's Human Research Program is focused on addressing health risks associated with long-duration missions on the International Space Station (ISS) and future exploration-class missions beyond low Earth orbit. Visual acuity changes observed after short-duration missions were largely transient, but now more than 50 percent of ISS astronauts have experienced more profound, chronic changes with objective structural findings such as optic disc edema, globe flattening and choroidal folds. These structural and functional changes are referred to as the visual impairment and intracranial pressure (VIIP) syndrome. Development of VIIP symptoms may be related to elevated intracranial pressure (ICP) secondary to spaceflight-induced cephalad fluid shifts, but this hypothesis has not been tested. The purpose of this study is to characterize fluid distribution and compartmentalization associated with long-duration spaceflight and to determine if a relation exists with vision changes and other elements of the VIIP syndrome. We also seek to determine whether the magnitude of fluid shifts during spaceflight, as well as any VIIP-related effects of those shifts, are predicted by the crewmember's pre-flight status and responses to acute hemodynamic manipulations, specifically posture changes and lower body negative pressure. Methods. We will examine a variety of physiologic variables in 10 long-duration ISS crewmembers using the test conditions and timeline presented in the figure below. Measures include: (1) fluid compartmentalization (total body water by D2O, extracellular fluid by NaBr, intracellular fluid by calculation, plasma volume by CO rebreathe, interstitial fluid by calculation); (2) forehead/eyelids, tibia, and calcaneus tissue thickness (by ultrasound); (3) vascular dimensions by ultrasound (jugular veins, cerebral and carotid arteries, vertebral arteries and veins, portal vein); (4) vascular dynamics by MRI (head/neck blood flow, cerebrospinal fluid

  8. Water-soluble vitamins.

    PubMed

    Konings, Erik J M

    2006-01-01

    Simultaneous Determination of Vitamins.--Klejdus et al. described a simultaneous determination of 10 water- and 10 fat-soluble vitamins in pharmaceutical preparations by liquid chromatography-diode-array detection (LC-DAD). A combined isocratic and linear gradient allowed separation of vitamins in 3 distinct groups: polar, low-polar, and nonpolar. The method was applied to pharmaceutical preparations, fortified powdered drinks, and food samples, for which results were in good agreement with values claimed. Heudi et al. described a separation of 9 water-soluble vitamins by LC-UV. The method was applied for the quantification of vitamins in polyvitaminated premixes used for the fortification of infant nutrition products. The repeatability of the method was evaluated at different concentration levels and coefficients of variation were <6.5%. The concentrations of vitamins found in premixes with the method were comparable to the values declared. A disadvantage of the methods mentioned above is that sample composition has to be known in advance. According to European legislation, for example, foods might be fortified with riboflavin phosphate or thiamin phosphate, vitamers which are not included in the simultaneous separations described. Vitamin B2.--Viñas et al. elaborated an LC analysis of riboflavin vitamers in foods. Vitamin B2 can be found in nature as the free riboflavin, but in most biological materials it occurs predominantly in the form of 2 coenzymes, flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD). Several methods usually involve the conversion of these coenzymes into free riboflavin before quantification of total riboflavin. According to the authors, there is growing interest to know flavin composition of foods. The described method separates the individual vitamers isocratically. Accuracy of the method is tested with 2 certified reference materials (CRMs). Vitamin B5.-Methods for the determination of vitamin B5 in foods are limited

  9. water-soluble fluorocarbon coating

    NASA Technical Reports Server (NTRS)

    Nanelli, P.

    1979-01-01

    Water-soluble fluorocarbon proves durable nonpolluting coating for variety of substrates. Coatings can be used on metals, masonry, textiles, paper, and glass, and have superior hardness and flexibility, strong resistance to chemicals fire, and weather.

  10. Method for estimating solubility parameter

    NASA Technical Reports Server (NTRS)

    Lawson, D. D.; Ingham, J. D.

    1973-01-01

    Semiempirical correlations have been developed between solubility parameters and refractive indices for series of model hydrocarbon compounds and organic polymers. Measurement of intermolecular forces is useful for assessment of material compatibility, glass-transition temperature, and transport properties.

  11. Tough, Soluble, Aromatic, Thermoplastic Copolyimides

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G. (Inventor)

    1998-01-01

    Tough, soluble, aromatic, thermoplastic copolyimides were prepared by reacting 4,4'-oxydiphthalic anhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydianiline. These copolyimides were found to be soluble in common amide solvents such as N,N'-dimethyl acetamide, N-methylpyrrolidinone, and dimethylformamide allowing them to be applied as the fully imidized copolymer and to be used to prepare a wide range of articles.

  12. Uphill transport of rare-earth metals through a highly stable supported liquid membrane based on an ionic liquid.

    PubMed

    Kubota, Fukiko; Shimobori, Yousuke; Koyanagi, Yusuke; Shimojo, Kojiro; Kamiya, Noriho; Goto, Masahiro

    2010-01-01

    We have developed a highly stable supported liquid membrane based on ionic liquids (ILs) for the separation of rare-earth metals, employing N,N-dioctyldiglycol amic acid as a mobile carrier. The quantitative transport of Y and Eu through the membrane was successfully attained, and separation from metal impurities, Zn, was efficiently accomplished. A membrane stable enough for long-term operation was constructible from imidazolium-based ILs having a longer alkyl chain, such as octyl or dodecyl groups in an imidazolium cation.

  13. More than a drop in the bucket: decentralized membrane-based drinking water refill stations in southeast Asia.

    PubMed

    Sima, Laura C; Elimelech, Menachem

    2013-07-16

    Decentralized membrane-based water treatment and refill stations represent a viable and growing business model in Southeast Asia, which rely upon the purchase of water from refill stations by consumers. This feature article discusses these water treatment and refill stations, including the appropriateness of the technology, the suitability of the business models employed, and the long-term environmental and operational sustainability of these systems. We also provide an outlook for the sector, highlighting key technical challenges that need to be addressed in order to improve the capacity of these systems, such that they can become an effective and financially viable solution.

  14. Fluid Mechanics

    NASA Astrophysics Data System (ADS)

    Pnueli, David; Gutfinger, Chaim

    1997-01-01

    This text is intended for the study of fluid mechanics at an intermediate level. The presentation starts with basic concepts, in order to form a sound conceptual structure that can support engineering applications and encourage further learning. The presentation is exact, incorporating both the mathematics involved and the physics needed to understand the various phenomena in fluid mechanics. Where a didactical choice must be made between the two, the physics prevails. Throughout the book the authors have tried to reach a balance between exact presentation, intuitive grasp of new ideas, and creative applications of concepts. This approach is reflected in the examples presented in the text and in the exercises given at the end of each chapter. Subjects treated are hydrostatics, viscous flow, similitude and order of magnitude, creeping flow, potential flow, boundary layer flow, turbulent flow, compressible flow, and non-Newtonian flows. This book is ideal for advanced undergraduate students in mechanical, chemical, aerospace, and civil engineering. Solutions manual available.

  15. The solubility of noble gases in crude oil at 25-100°C

    USGS Publications Warehouse

    Kharaka, Yousif K.; Specht, Daniel J.

    1988-01-01

    The solubility of the noble gases He, Ne, Ar, Kr and Xe was measured in two typical crude oils at temperatures of 25–100°C. The oil samples were obtained from the Elk Hills oil field located in southern San Joaquin Valley, California. The experimental procedure consisted of placing a known amount of gas with a known volume of crude oil in a stainless steel hydrothermal pressure vessel. The vessel was housed inside an oven and the entire unit rotates providing continuous mixing. The amount of gas dissolved in oil at a measured temperature and partial pressure of gas was used to calculate the solubility constants for these gases. Results show that the solubility of He and Ne in both oils is approximately the same; solubility then increases with atomic mass, with the solubility of Xe at 25°C being two orders of magnitude higher than that of He. The gas solubilities are somewhat higher in the lower density (higher API gravity) oil. The solubility of Ar is approximately constant in the range of temperatures of this study. The solubilities of He and Ne increase, but those of Kr and Xe decrease with increasing temperatures. Solubilities of noble gases in crude oil are significantly higher than their solubilities in water. For example, the solubilities of He and Xe at 25°C in the light oil of this study are, respectively, 3 and 24 times higher than their solubilities in pure water, and they are 15 and 300 times higher than in a brine with a salinity of 350,000 mg/l dissolved solids. These large and variable differences in the solubilities of noble gases in oil and water indicate that, in sedimentary basins with oil, these gases must be partitioned between oil, water and natural gas before they are used to deduce the origin and residence time of these fluids.

  16. Union soluble oil flood in El Dorado cores

    SciTech Connect

    Chiou, C.S.

    1983-02-01

    Results are presented of laboratory experiments using Union's soluble oil flood process in El Dorado cores. The core flood is to provide complete information on fluid compositions and phase behavior of the effluents such that adequate core flood match using the chemical flood simulator can be made. This step is essential for evaluating reservoir performance on the South Pattern of the El Dorado Micellar-Polymer Project. The results show the caustic preflush in the flood process causes face plugging of the field cores. The problem was controlled by using chelating agents along with the caustic fluid to keep divalent cations in solution. The required amount of chelating agent was determined to be ca 25 times as strong as the original design for the field test. Liquid chromatography analysis of sulfonate provides valuable information on selective fractionation of monosulfonate in the micellar fluid. 10 references.

  17. Thermodynamic modeling for solubility prediction of indomethacin in self-nanoemulsifying drug delivery system (SNEDDS) and its individual components.

    PubMed

    Shakeel, Faiyaz; Haq, Nazrul; Alanazi, Fars K; Alsarra, Ibrahim A

    2014-09-01

    Abstract For the development of an effective self-nanoemulsifying drug delivery system (SNEDDS) of poorly soluble drugs, the knowledge of the solubility in its oil phase and SNEDDS are one of the most important factors to avoid possibility of drug to get phase separated or precipitated upon dilution with gastrointestinal fluids. With this background, this study was undertaken to determine the equilibrium saturated solubility as well as mole fraction solubility of indomethacin in prepared SNEDDS and its individual components at the temperature range of 295.15 to 320.15 K. The equilibrium solubilities of indomethacin in each sample matrices were determined by an isothermal mechanical shaking method and the resulting data was analyzed by regression analysis. The experimental mole fraction solubility data of indomethacin at various temperatures was well correlated with the modified Apelblat model. The equilibrium saturated solubility as well as mole fraction solubility of indomethacin was found to be increased with increase in temperature in SNEDDS as well as in its individual components. The mole fraction solubility of indomethacin was found to be significantly higher in Tween-80 than SNEDDS, Labrafil-M1944CS and Transcutol-HP. These preliminary studies on solubility could be a useful tool for the development of an efficient and thermodynamically stable SNEDDS formulation of various poorly soluble drugs to enhance their solubility/dissolution and oral bioavailability.

  18. The Chemical Behavior of Fluids Released during Deep Subduction Based on Fluid Inclusions

    NASA Astrophysics Data System (ADS)

    Frezzotti, M. L.; Ferrando, S.

    2014-12-01

    We present a review of current research on fluid inclusions in (HP-) UHP metamorphic rocks that, combined with existing experimental research and thermodynamic models, allow us to investigate the chemical and physical properties of fluids released during deep subduction, their solvent and element transport capacity, and the subsequent implications for the element recycling in the mantle wedge. An impressive number of fluid inclusion studies indicate three main populations of fluid inclusions in HP and UHP metamorphic rocks: i) aqueous and/or non-polar gaseous fluid inclusions (FI), ii) multiphase solid inclusions (MSI), and iii) melt inclusions (MI). Chemical data from preserved fluid inclusions in rocks match with and implement "model" fluids by experiments and thermodynamics, revealing a continuity behind the extreme variations of physico-chemical properties of subduction-zone fluids. From fore-arc to sub-arc depths, fluids released by progressive devolatilization reactions from slab lithologies change from relatively diluted chloride-bearing aqueous solutions (± N2), mainly influenced by halide ligands, to (alkali) aluminosilicate-rich aqueous fluids, in which polymerization probably governs the solubility and transport of major (e.g., Si and Al) and trace elements (including C). Fluid inclusion data implement the petrological models explaining deep volatile liberation in subduction zones, and their flux into the mantle wedge.

  19. Fabricating neuromast-inspired gel structures for membrane-based hair cell sensing

    NASA Astrophysics Data System (ADS)

    Tamaddoni, Nima J.; Stephens, Christopher P.; Sarles, S. A.

    2012-04-01

    Recent research has shown that a new class of mechanical sensor, assembled from biomolecules and which features an artificial cell membrane as the sensing element, can be used to mimic basic hair cell mechanotransduction in vertebrates. The work presented in this paper is motivated by the need to increase sensor performance and stability by refining the methods used to fabricate and connect lipid-encapsulated hydrogels. Inspired by superficial neuromasts found on fish, three hydrogel materials are compared for their ability to be readily shaped into neuromast-inspired geometries and enable lipid bilayer formation using self-assembly at an oil/water interface. Agarose, polyethylene glycol (PEG, 6kg/mole), and hydroxyethyl methacrylate (HEMA) gel materials are compared. The results of this initial study determined that UV-curable gel materials such as PEG and HEMA enable more accurate shaping of the gel-needed for developing a sensor that uses a gel material both for mechanical support and membrane formation-compared to agarose. However, the lower hydrophobicity of agarose and PEG materials provide a more fluid, water-like environment for membrane formation-unlike HEMA. In working toward a neuromast-inspired design, a final experiment demonstrates that a bilayer can also be formed directly between two lipid-covered PEG surfaces. These initial results suggest that candidate gel materials with a low hydrophobicity, high fluidity, and a low modulus can be used to provide membrane support.

  20. Predicting the Solubility Advantage of Amorphous Pharmaceuticals: A Novel Thermodynamic Approach.

    PubMed

    Paus, Raphael; Ji, Yuanhui; Vahle, Lisa; Sadowski, Gabriele

    2015-08-03

    For the solubility and bioavailability of poorly soluble active pharmaceutical ingredients (APIs) to be improved, the transformation of crystalline APIs to the amorphous state has often been shown to be advantageous. As it is often difficult to measure the solubility of amorphous APIs, the application of thermodynamic models is the method of choice for determining the solubility advantage. In this work, the temperature-dependent solubility advantage of an amorphous API versus its crystalline form was predicted for five poorly soluble APIs in water (glibenclamide, griseofulvin, hydrochlorothiazide, indomethacin, and itraconazole) based on modeling the API/solvent phase diagrams using the perturbed-chain statistical associating fluid theory (PC-SAFT). Evaluation of the performance of this approach was performed by comparing the predicted solubility advantage to experimental data and to the solubility advantage calculated by the commonly applied Gibbs-energy-difference method. For all of the systems considered, PC-SAFT predictions of the solubility advantage are significantly more accurate than the results obtained from the Gibbs-energy-difference method.

  1. Solubility Classification of Airborne Uranium Products from LWR-Fuel Plants

    SciTech Connect

    kalkwarf, D. R.

    1980-08-01

    Airborne dust samples were obtained from various locations within plants manufacturing fuel elements for light-water reactors, and the dissolution rates of uranium from these samples into simulated lung fluid at 37°C were measured. These measurements were used to classify the solubilities of the samples in terms of the lung clearance model proposed by the International Commission on Radiological Protection. Similar evaluations were performed for samples of pure uranium compounds expected as components in plant dust. The variation in solubility classifications of dust encountered along the fuel production lines is described and correlated with the process chemistry and the solubility classifications of the pure uranium compounds.

  2. The Solubility Rules: Why Are All Acetates Soluble?

    NASA Astrophysics Data System (ADS)

    van der Sluys, William G.

    2001-01-01

    According to the solubility rules presented in many introductory chemistry texts, all (or most) acetate salts are soluble in aqueous solution. The thermodynamic factors that contribute to the solubility of acetates are compared with those of other slightly basic anions. In particular, the hydration enthalpy of acetate is calculated using the Born-Haber approach, from lattice energies, heats of solution, and the hydration energies of several cations. The hydration enthalpy of acetate (-375 kJ/mol) is similar to that of chloride ({355 kJ/mol), nitrite ({383 kJ/mol), and nitrate ({370 kJ/mol), which are all considerably less exothermic than fluoride ({497 kJ/mol). This was somewhat unexpected, since hydration enthalpies generally correlate well with the acid-base properties of an ion, and acetate is more basic than fluoride. Factors influencing the solubility and acid-base properties of acetates, such as the electron donating and hydrophobic nature of the methyl group, are discussed in light of the thermodynamic data.

  3. Preliminary considerations concerning actinide solubilities

    SciTech Connect

    Newton, T.W.; Bayhurst, B.P.; Daniels, W.R.; Erdal, B.R.; Ogard, A.E.

    1980-01-01

    Work at the Los Alamos Scientific Laboratory on the fundamental solution chemistry of the actinides has thus far been confined to preliminary considerations of the problems involved in developing an understanding of the precipitation and dissolution behavior of actinide compounds under environmental conditions. Attempts have been made to calculate solubility as a function of Eh and pH using the appropriate thermodynamic data; results have been presented in terms of contour maps showing lines of constant solubility as a function of Eh and pH. Possible methods of control of the redox potential of rock-groundwater systems by the use of Eh buffers (redox couples) is presented.

  4. Drilling fluid

    SciTech Connect

    Russell, J.A.; Patel, B.B.

    1987-11-03

    A drilling fluid additive mixture is described consisting essentially of a sulfoalkylated tannin in admixture with a non-sulfoalkylated alkali-solubilized lignite wherein the weight ratio of the sulfoalkylated tannin to the non-sulfoalkylated lignite is in the range from about 2:1 to about 1:1. The sulfoalkylated tannin has been sulfoalkylated with at least one -(C(R-)/sub 2/-SO/sub 3/M side chain, wherein each R is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to about 5 carbon atoms, and M is selected from the group consisting of ammonium and the alkali metals.

  5. Solubility limits on radionuclide dissolution

    SciTech Connect

    Kerrisk, J.F.

    1984-12-31

    This paper examines the effects of solubility in limiting dissolution rates of a number of important radionuclides from spent fuel and high-level waste. Two simple dissolution models were used for calculations that would be characteristics of a Yucca Mountain repository. A saturation-limited dissolution model, in which the water flowing through the repository is assumed to be saturated with each waste element, is very conservative in that it overestimates dissolution rates. A diffusion-limited dissolution model, in which element-dissolution rates are limited by diffusion of waste elements into water flowing past the waste, is more realistic, but it is subject to some uncertainty at this time. Dissolution rates of some elements (Pu, Am, Sn, Th, Zr, Sm) are always limited by solubility. Dissolution rates of other elements (Cs, Tc, Np, Sr, C, I) are never solubility limited; their release would be limited by dissolution of the bulk waste form. Still other elements (U, Cm, Ni, Ra) show solubility-limited dissolution under some conditions. 9 references, 3 tables.

  6. Non-noble metal based electro-catalyst compositions for proton exchange membrane based water electrolysis and methods of making

    DOEpatents

    Kumta, Prashant N.; Kadakia, Karan Sandeep; Datta, Moni Kanchan; Velikokhatnyi, Oleg

    2017-02-07

    The invention provides electro-catalyst compositions for an anode electrode of a proton exchange membrane-based water electrolysis system. The compositions include a noble metal component selected from the group consisting of iridium oxide, ruthenium oxide, rhenium oxide and mixtures thereof, and a non-noble metal component selected from the group consisting of tantalum oxide, tin oxide, niobium oxide, titanium oxide, tungsten oxide, molybdenum oxide, yttrium oxide, scandium oxide, cooper oxide, zirconium oxide, nickel oxide and mixtures thereof. Further, the non-noble metal component can include a dopant. The dopant can be at least one element selected from Groups III, V, VI and VII of the Periodic Table. The compositions can be prepared using a surfactant approach or a sol gel approach. Further, the compositions are prepared using noble metal and non-noble metal precursors. Furthermore, a thin film containing the compositions can be deposited onto a substrate to form the anode electrode.

  7. A composite membrane based on a biocompatible cellulose as a host of gel polymer electrolyte for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Xiao, S. Y.; Yang, Y. Q.; Li, M. X.; Wang, F. X.; Chang, Z.; Wu, Y. P.; Liu, X.

    2014-12-01

    A composite polymer membrane is prepared by coating poly(vinylidene fluoride) (PVDF) on the surface of a membrane based on methyl cellulose (MC) which is environmentally friendly and cheap. Its characteristics are investigated by scanning electron microscopy, FT-IR, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The outer PVDF layers are porous which results in high electrolyte uptake and the lithium ion transference number is much larger than that of the pure MC. Moreover, the cell based on Li//LiFePO4 delivers high discharge capacity and good rate behavior in the range of 4.2-2.5 V when the composite membrane is used as the separator and the host of a gel polymer electrolyte, lithium as the counter and reference electrode, and LiFePO4 as cathode. The obtained results suggest that this unique composite membrane shows great attraction in the lithium ion batteries with high safety and low cost.

  8. [Membrane-based photochemical systems as models for photosynthetic cells]. Progress report, February 15, 1990--August 31, 1992

    SciTech Connect

    Hurst, J.K.

    1992-12-31

    The objectives of this research are to improve our conceptual view of the ways in which membranes and interfaces can be used to control chemical reactivity. We have focused on understanding three elementary processes that are central to developing membrane-based integrated chemical systems for water photolysis or related photoconversion/photostorage processes. Specifically, we have sought to identify: the influence of interfaces upon charge separation/recombination reactions, pathways for transmembrane charge separation across hydrocarbon bilayer membranes, and mechanisms of water oxidation catalyzed by transition metal coordination complexes. Historically, the chemical dynamics of each of these processes has been poorly understood, with numerous unresolved issues and conflicting viewpoints appearing in the literature. As described in this report our recent research has led to considerable clarification of the underlying reaction mechanisms.

  9. A Visual Basic simulation software tool for performance analysis of a membrane-based advanced water treatment plant.

    PubMed

    Pal, P; Kumar, R; Srivastava, N; Chowdhury, J

    2014-02-01

    A Visual Basic simulation software (WATTPPA) has been developed to analyse the performance of an advanced wastewater treatment plant. This user-friendly and menu-driven software is based on the dynamic mathematical model for an industrial wastewater treatment scheme that integrates chemical, biological and membrane-based unit operations. The software-predicted results corroborate very well with the experimental findings as indicated in the overall correlation coefficient of the order of 0.99. The software permits pre-analysis and manipulation of input data, helps in optimization and exhibits performance of an integrated plant visually on a graphical platform. It allows quick performance analysis of the whole system as well as the individual units. The software first of its kind in its domain and in the well-known Microsoft Excel environment is likely to be very useful in successful design, optimization and operation of an advanced hybrid treatment plant for hazardous wastewater.

  10. [Development and preclinical studies of insulating membranes based on poly-3-hydroxybutyrate-co-3-hydroxyvalerate for guided bone regeneration].

    PubMed

    Ivanov, S Yu; Bonartsev, A P; Gazhva, Yu V; Zharkova, I I; Mukhametshin, R F; Mahina, T K; Myshkina, V L; Bonartseva, G A; Voinova, V V; Andreeva, N V; Akulina, E A; Kharitonova, E S; Shaitan, K V; Muraev, A A

    2015-01-01

    Bone tissue damages are one of the dominant causes of temporary disability and developmental disability. Currently, there are some methods of guided bone regeneration employing different osteoplastic materials and insulation membranes used in surgery. In this study, we have developed a method of preparation of porous membranes from the biopolymer poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), produced by a strain of Azotobacter chroococcum 7B. The biocompatibility of the porous membranes was investigated in vitro using mesenchymal stem cells (MSCs) and in vivo on laboratory animals. The cytotoxicity test showed the possibility of cell attachment on membrane and histological studies confirmed good insulating properties the material. The data obtained demonstrate the high biocompatibility and the potential application of insulating membranes based on PHBV in bone tissue engineering.

  11. Microporous membrane-based liver tissue engineering for the reconstruction of three-dimensional functional liver tissues in vitro.

    PubMed

    Kasuya, Junichi; Tanishita, Kazuo

    2012-01-01

    To meet the increasing demand for liver tissue engineering, various three-dimensional (3D) liver cell culture techniques have been developed. Nevertheless, conventional liver cell culture techniques involving the suspending cells in extracellular matrix (ECM) components and the seeding of cells into 3D biodegradable scaffolds have an intrinsic shortcoming, low cell-scaffold ratios. We have developed a microporous membrane-based liver cell culture technique. Cell behaviors and tissue organization can be controlled by membrane geometry, and cell-dense thick tissues can be reconstructed by layering cells cultured on biodegradable microporous membranes. Applications extend from liver parenchymal cell monoculture to multi-cell type cultures for the reconstruction of 3D functional liver tissue. This review focuses on the expanding role for microporous membranes in liver tissue engineering, primarily from our research.

  12. Perfluorinated carbon-chain copolymers with functional groups and cation exchange membranes based on them: synthesis, structure and properties

    NASA Astrophysics Data System (ADS)

    Kirsh, Yu E.; Smirnov, S. A.; Popkov, Yu M.; Timashev, Sergei F.

    1990-06-01

    The review is devoted to perfluorinated polymers with sulphonic and carboxylic acid groups and to cation exchange membranes based on them. The synthesis is described of copolymers of tetrafluoroethylene with perfluorovinyl ethers containing functional groups by radical copolymerisation in an organic medium and in aqueous emulsions. Special features of the copolymerisation and approaches to obtaining copolymers with set characteristics are discussed. Data are presented on the structure and physicochemical properties of the polymeric films. Attempts to form membranes from the polymers obtained, the means of strengthening them and methods for chemical modification are described. Data are correlated on the influence of structure and polymer composition and the nature of the functional groups on the electrochemical characteristics of membranes. Special features of the functioning of perfluorinated membranes in the process for making chlorine and alkali by the electrolysis of sodium chloride solution are considered. The bibliography has 104 references.

  13. Solubility characterization of airborne uranium from a uranium recycling plant.

    PubMed

    Metzger, Robert; Cole, Leslie

    2004-07-01

    Solubility profiles of uranium dusts in a uranium recycling plant were determined by performing in vitro solubility tests on breathing zone air samples conducted in all process areas of the processing plant. The recycling plant produces high density shields, closed end tubes that are punched and formed from uranium sheet metal, and high-fired uranium oxide, which is used as a catalyst. The recycled uranium is cut and melted in a vacuum furnace, and part of the molten uranium is poured into molds for further processing. Air samples were taken in process areas under normal working conditions. The dissolution rate of the uranium in a simulant solution of extracellular airway lining fluid (Gamble's solution) was then determined over the next 28 d. Airborne uranium in the oxide section of the plant was found to be highly insoluble with 99% of the uranium having a dissolution half time in excess of 100 d. The solubility of the airborne uranium in other areas of the facility was only slightly more soluble with over 90% of the airborne uranium having dissolution half times in excess of 90 d.

  14. Supercritical fluid thermodynamics for coal processing. Final report, September 15, 1988--September 14, 1991

    SciTech Connect

    van Swol, F.; Eckert, C.A.

    1988-09-15

    The main objective of this research is to develop an equation of state that can be used to predict solubilities and tailor supercritical fluid solvents for the extraction and processing of coal. To meet this objective we have implemented a two-sided. approach. First, we expanded the database of model coal compound solubilities in higher temperature fluids, polar fluids, and fluid mixtures systems. Second, the unique solute/solute, solute/cosolvent and solute/solvent intermolecular interactions in supercritical fluid solutions were investigated using spectroscopic techniques. These results increased our understanding of the molecular phenomena that affect solubility in supercritical fluids and were significant in the development of an equation of state that accurately reflects the true molecular makeup of the solution. (VC)

  15. Viscous fingering with partially miscible fluids

    NASA Astrophysics Data System (ADS)

    Fu, X.; Cueto-Felgueroso, L.; Juanes, R.

    2015-12-01

    When a less viscous fluid displaces a more viscous fluid, the contrast in viscosity destabilizes the interface between the two fluids, leading to the formation of fingers. Experimental and numerical studies of viscous fingering have focused on fluids that are either fully miscible (e.g. water and glycerol) or perfectly immiscible (e.g. water and oil). In practice, however, the miscibility of two fluids can change appreciably with temperature and pressure, and often falls into the case of partial miscibility, where two fluids have limited solubility in each other (e.g. CO2 and water). Following our recent work for miscible systems (Jha et al., PRL 2011, 2013) and immiscible systems (Cueto-Felgueroso and Juanes, PRL 2012, JFM 2014), here we propose a phase-field model for fluid-fluid displacements in a porous medium, when the two fluids have limited (but nonzero) solubility in one another. In our model, partial miscibility is characterized through the design of the thermodynamic free energy of the two-fluid system. We express the model in dimensionless form and elucidate the key dimensionless groups that control the behavior of the system. We present high-resolution numerical simulations of the model applied to the viscous fingering problem. On one hand, we demonstrate the effect of partial miscibility on the hydrodynamic instability. On the other, we elucidate the role of the degree of fingering on the rate of mutual fluid dissolution. Figure caption: final snapshots in simulations of viscous fingering with a two-fluid system mimicking that of CO2 and water. The colormap corresponds to the concentration of CO2. A band of less viscous gas phase rich in CO2 (red) displaces through the more viscous liquid phase that is undersaturated with CO2 (blue). At the fluid interface, an exchange of CO2 occurs as a result of local chemical potentials that drives the system towards thermodynamic equilibrium. This results in a shrinkage of gas phase as well as a local increase in

  16. Solubility of sparingly soluble drug derivatives of anthranilic acid.

    PubMed

    Domańska, Urszula; Pobudkowska, Aneta; Pelczarska, Aleksandra

    2011-03-24

    This work is a continuation of our systematic study of the solubility of pharmaceuticals (Pharms). All substances here are derivatives of anthranilic acid, and have an anti-inflammatory direction of action (niflumic acid, flufenamic acid, and diclofenac sodium). The basic thermal properties of pure Pharms, i.e., melting and glass-transition temperatures as well as the enthalpy of melting, have been measured with the differential scanning microcalorimetry technique (DSC). Molar volumes have been calculated with the Barton group contribution method. The equilibrium mole fraction solubilities of three pharmaceuticals were measured in a range of temperatures from 285 to 355 K in three important solvents for Pharm investigations: water, ethanol, and 1-octanol using a dynamic method and spectroscopic UV-vis method. The experimental solubility data have been correlated by means of the commonly known G(E) equation: the NRTL, with the assumption that the systems studied here have revealed simple eutectic mixtures. pK(a) precise measurement values have been investigated with the Bates-Schwarzenbach spectrophotometric method.

  17. Terpolymer composition for aqueous drilling fluids

    SciTech Connect

    Giddings, D.M.; Williamson, C.D.

    1987-07-07

    A method is described of improving high temperature fluid loss and rheology stabilization of high calcium brine clay-containing aqueous oil well drilling fluids which comprises adding a stabilizing amount of a water-soluble terpolymer composition comprising: a polymer prepared by polymerizing the following monomer ingredients; the composition containing lignin, modified lignin, brown coal or modified brown coal in an amount ranging between 5-95% with the brown coal or modified brown coal having been presented during the polymerization of the water-soluble polymer. The lignin, modified lignin, brown coal or modified brown coal is from the group consisting of lignites, sulphonated lignites, lignins, leonardites, lignosulfonates, alkali metal humic acid salts, humic acids, and sulphonated humic acids.

  18. Overexpression of Soluble Recombinant Human Lysyl Oxidase by Using Solubility Tags: Effects on Activity and Solubility

    PubMed Central

    Smith, Madison A.; Gonzalez, Jesica; Hussain, Anjum; Oldfield, Rachel N.; Johnston, Kathryn A.; Lopez, Karlo M.

    2016-01-01

    Lysyl oxidase is an important extracellular matrix enzyme that has not been fully characterized due to its low solubility. In order to circumvent the low solubility of this enzyme, three solubility tags (Nus-A, Thioredoxin (Trx), and Glutathione-S-Transferase (GST)) were engineered on the N-terminus of mature lysyl oxidase. Total enzyme yields were determined to be 1.5 mg for the Nus-A tagged enzyme (0.75 mg/L of media), 7.84 mg for the Trx tagged enzyme (3.92 mg/L of media), and 9.33 mg for the GST tagged enzyme (4.67 mg/L of media). Enzymatic activity was calculated to be 0.11 U/mg for the Nus-A tagged enzyme and 0.032 U/mg for the Trx tagged enzyme, and no enzymatic activity was detected for the GST tagged enzyme. All three solubility-tagged forms of the enzyme incorporated copper; however, the GST tagged enzyme appears to bind adventitious copper with greater affinity than the other two forms. The catalytic cofactor, lysyl tyrosyl quinone (LTQ), was determined to be 92% for the Nus-A and Trx tagged lysyl oxidase using the previously reported extinction coefficient of 15.4 mM−1 cm−1. No LTQ was detected for the GST tagged lysyl oxidase. Given these data, it appears that Nus-A is the most suitable tag for obtaining soluble and active recombinant lysyl oxidase from E. coli culture. PMID:26942005

  19. A New Simulated Plasma for Assessing the Solubility of Mineral Trioxide Aggregate

    PubMed Central

    Samiei, Mohammad; Shahi, Shahriar; Aslaminabadi, Naser; Valizadeh, Hadi; Aghazadeh, Zahra; Pakdel, Seyyed Mahdi Vahid

    2015-01-01

    Introduction: Solubility of mineral trioxide aggregate (MTA) is an important characteristic that affects other properties such as microleakage and biocompatibility. Distilled water (DW) has previously been used for solubility tests. This experimental study compared the solubility of MTA in DW, synthetic tissue fluid (STF) and new simulated plasma (SP). Methods and Materials: In this study, 36 samples of tooth-colored ProRoot MTA were prepared and divided into three groups (n=12) to be immersed in three different solutions (DW, STF, and SP). Solubility tests were conducted at 2, 5, 9, 14, 21, 30, 50, and 78-day intervals. The unequal variance F-test (Welch test) was utilized to determine the effect of solubility media and Games-Howell analysis was used for pairwise comparisons. The repeated-measures ANOVA was used to assess the importance of immersion duration. Results: Welch test showed significant differences in solubility rates of samples between all the different solubility media at all the study intervals (P<0.05) except for the 14-day interval (P=0.094). The mixed repeated-measures ANOVA revealed a significant difference in solubility rate of MTA in three different solutions at all time-intervals (P=0.000). Games-Howell post-hoc test revealed that all pairwise comparisons were statistically significant at all time-intervals (P=0.000). Conclusion: Based on the findings of this study, the long-term solubility of MTA in simulated plasma was less than that in synthetic tissue fluid and distilled water. PMID:25598806

  20. Soluble metalloendopeptidases and neuroendocrine signaling.

    PubMed

    Shrimpton, Corie N; Smith, A Ian; Lew, Rebecca A

    2002-10-01

    Peptidases play a vital and often highly specific role in the physiological and pathological generation and termination of peptide hormone signals. The thermolysin-like family of metalloendopeptidases involved in the extracellular processing of neuroendocrine and cardiovascular peptides are of particular significance, reflecting both their specificity for particular peptide substrates and their utility as therapeutic targets. Although the functions of the membrane-bound members of this family, such as angiotensin-converting enzyme and neutral endopeptidase, are well established, a role for the predominantly soluble family members in peptide metabolism is only just emerging. This review will focus on the biochemistry, cell biology, and physiology of the soluble metalloendopeptidases EC 3.4.24.15 (thimet oligopeptidase) and EC 3.4.24.16 (neurolysin), as well as presenting evidence that both peptidases play an important role in such diverse functions as reproduction, nociception, and cardiovascular homeostasis.

  1. Tough soluble aromatic thermoplastic copolyimides

    NASA Technical Reports Server (NTRS)

    Bryant, Robert G. (Inventor)

    2000-01-01

    Tough, soluble, aromatic, thermoplastic copolyimides were prepared by reacting 4,4'-oxydiphthalic anhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydianiline. Alternatively, these copolyimides may be prepared by reacting 4,4'-oxydiphthalic anhydride with 3,4,3',4'-biphenyltetracarboxylic dianhydride and 3,4'-oxydiisocyanate. Also, the copolyimide may be prepared by reacting the corresponding tetra acid and ester precursors of 4,4'-oxydiphthalic anhydride and 3,4,3',4'-biphenyltetracarboxylic dianhydride with 3,4'-oxydianiline. These copolyimides were found to be soluble in common amide solvents such as N,N'-dimethyl acetamide, N-methylpyrrolidinone, and dimethylformamide allowing them to be applied as the fully imidized copolymer and to be used to prepare a wide range of articles.

  2. Droplet evaporation on a soluble substrate

    NASA Astrophysics Data System (ADS)

    Mailleur, Alexandra; Pirat, Christophe; Colombani, Jean; CNES Collaboration

    2015-11-01

    Stains left by evaporated droplets are ubiquitous in everyday life as well as in industrial processes. Whatever the composition of the evaporating liquid (colloidal suspensions, biological fluids...), the stains are mostly constituted by a deposit at the periphery of the dried drop, similar to a coffee stain (Deegan, 1997). All these studies have been carried with non-reacting solids. In this presentation, we focus on the behavior of a pure-water droplet evaporating on a soluble substrate which is more complex, since three phenomena are strongly interacting: the dissolution of the substrate, the diffusion/convection of the dissolved species into the drop and the evaporation of the liquid. NaCl and KCl single crystals have been chosen for this experimental study as they are fast-dissolving solids. We have observed that the dissolution induces a pinning of the triple line from the beginning of the evaporation, leading to a decrease of the contact angle in time. At the end of the evaporation, a peripheral deposit is always formed, proof of an outward flow inside the drop (coffee-ring effect). The authors would like to thank the CNES for the financial support.

  3. Synthesis of water soluble graphene.

    PubMed

    Si, Yongchao; Samulski, Edward T

    2008-06-01

    A facile and scalable preparation of aqueous solutions of isolated, sparingly sulfonated graphene is reported. (13)C NMR and FTIR spectra indicate that the bulk of the oxygen-containing functional groups was removed from graphene oxide. The electrical conductivity of thin evaporated films of graphene (1250 S/m) relative to similarly prepared graphite (6120 S/m) implies that an extended conjugated sp (2) network is restored in the water soluble graphene.

  4. Soluble Precursor Route to Polyanilines

    DTIC Science & Technology

    1993-01-01

    condensation were not successful, but further work produced polymer under the following conditions: Synthesis Diketone I (2.40 g, 10.0 mmol) in 10 mL...goal of producing a processible form of the conducting polymer polyaniline (PANI), the Phase I program concentrated on development of the synthesis of...extension of the original research to a Phase II effort. Diketone - Diamine Polycondensation Towards a Soluble PAni Precursor To achieve the

  5. Thermophysical Properties of Fluids and Fluid Mixtures

    SciTech Connect

    Sengers, Jan V.; Anisimov, Mikhail A.

    2004-05-03

    The major goal of the project was to study the effect of critical fluctuations on the thermophysical properties and phase behavior of fluids and fluid mixtures. Long-range fluctuations appear because of the presence of critical phase transitions. A global theory of critical fluctuations was developed and applied to represent thermodynamic properties and transport properties of molecular fluids and fluid mixtures. In the second phase of the project, the theory was extended to deal with critical fluctuations in complex fluids such as polymer solutions and electrolyte solutions. The theoretical predictions have been confirmed by computer simulations and by light-scattering experiments. Fluctuations in fluids in nonequilibrium states have also been investigated.

  6. Thermally stable drilling fluid additive comprised of a copolymer of catechol-based monomer

    SciTech Connect

    Patel, A.D.

    1986-06-17

    A water soluble polymer is described having thermal stability and exhibiting utility as an aqueous drilling fluid additive comprising: (a) a major portion of a catechol based monomer; (b) a minor portion of a dicarboxylic acid monomer.

  7. Magnetized drive fluids

    SciTech Connect

    Rosensweig, R.E.; Zahn, M.

    1986-04-01

    A process is described for recovering a first fluid from a porous subterranean formation which comprises injecting a displacement fluid in an effective amount to displace the first fluid, injecting a ferrofluid, applying a magnetic field containing a gradient of field intensity within the formation, driving the displacement fluid through the formation with the ferrofluid and recovering first fluid.

  8. Fluid sampling tool

    DOEpatents

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    2000-01-01

    A fluid-sampling tool for obtaining a fluid sample from a container. When used in combination with a rotatable drill, the tool bores a hole into a container wall, withdraws a fluid sample from the container, and seals the borehole. The tool collects fluid sample without exposing the operator or the environment to the fluid or to wall shavings from the container.

  9. [Soluble of Metals within TSP in Shanghai].

    PubMed

    Chang, Yan; Feng, Chong; Qu, Jian-guo; Zhang, Jing

    2015-04-01

    The dissolution of metals within aerosol particles is meaningful to evaluate the bioavailability and mobility of metals. Total suspended particles (TSP) samples were collected in Shanghai. We extracted the water soluble and acid soluble (pH = 2) metals by the mini-recirculation-leach-system and measured their concentrations by the high resolution inductively coupled plasma mass spectrometry. The dissolution kinetics were rapid, the maximum solubility of metals could be reached in a few minutes. Overall, the average water-soluble concentrations were low for Co, Cr, Cd, V and Ni, median for Cu, Pb and Mn and high for Fe, Al, Zn and Mg. Combine the soluble metal concentrations with the back trajectory, the original air mass had significant impacts on water soluble metal concentrations. The water solubility and acid solubility were different for various metals, the water solubility of Fe was the lowest (2.0%), others followed an order: Al, Cr, V, Pb, Co, Ni, Cu, Cd, Mn, Mg, Zn. The metals' solubility was increased with the decrease of the solvent pH value. While the chemical speciation of metals was the internal cause of metals' solubility, the metals' ionic potential and the water solubility was negatively correlated.

  10. The role of fluids in HFSE fractionation

    NASA Astrophysics Data System (ADS)

    Rapp, Jennifer; Klemme, Stephan; Scherer, Erik

    2010-05-01

    High field strength elements are important geochemical indicators in many geological settings, in particular in subduction zones. The HFSE signature of arc magmas is depleted relative to MORB, and there is much debate about the cause of this. Interaction between crustal and mantle rocks, and fluids liberated during metamorphism are critical for the transport of elements within the Earth, and the generation of diverse geochemical signatures. Relative depletions in HFSE have been attributed to the immobility of Ti in crustal fluids, and hence the retention of Ti and HFSE in rutile within the subducted slab. A fundamental premise of most mass-flux calculations in fluid transport is that Ti is essentially immobile in these metamorphic systems due to its low solubility in fluid, coupled with strong retention in Ti-bearing minerals such as rutile, ilmenite and titanite. As a consequence, the ‘constant Ti' frame of reference is widely used with evaluation of metasomatism and open-system behaviour, supported by experiments that have demonstrated quite low Ti solubility in aqueous fluids [1-3]. We have performed novel experiments in saline fluids, which indicate that F (and Cl) greatly enhances the solubility of rutile, and hence increases the mobility of Ti. We will show that this has implications for the mobility of the other HFSE, which are strongly sequestered into Ti-phases such as rutile [4,5]. The experimental run products have been analysed using isotope dilution ICP-MS techniques [6,7] to estimate rutile/fluid partition coefficients which may be used to determine the relative mobility of HFSE in some potential metamorphic fluids. We will show that fluids may have a strong fractionating influence on the HFSE budget of metamorphic rocks, and may influence our interpretation of the global Nb/Ta budget. References [1] Antignano, A. and Manning, C.E. (2008) Chem. Geology 255 283-293 [2] Audetat, A. and Keppler, H. (2001) Earth Planet. Sci. Lett. 232 393-402 [3

  11. Sensitivity and directionality of lipid bilayer mechanotransduction studied using a revised, highly durable membrane-based hair cell sensor

    NASA Astrophysics Data System (ADS)

    Tamaddoni, Nima; Freeman, Eric C.; Sarles, Stephen A.

    2015-06-01

    A bioinspired, membrane-based hair cell sensor consists of a planar lipid bilayer formed between two lipid-coated water droplets that connect to an artificial hair. This assembly enables motion of the hair caused by mechanical stimuli to vibrate the bilayer and produce a capacitive current. In this work, the mechanoelectrical transduction mechanism and sensing performance is experimentally characterized for a more-durable, revised hair cell embodiment that includes a cantilevered hair rooted firmly in the surrounding solid substrate. Specifically, this study demonstrates that the revised membrane-based hair cell sensor produces higher time rates of change in capacitance (0.8-6.0 nF s-1) in response to airflow across the hair compared to the original sensor (45-60 pF s-1) that did not feature a cantilevered hair. The 10-fold to 100-fold increase in the time rate change of capacitance corresponds to greater membrane bending and, thus, higher sensing currents. Membranes in the revised sensor exhibit changes in area due to bending on the order of 0.2-2.0%, versus 0.02% for the original sensor. Experiments also reveal that the bilayer displays highest sensitivity to mechanical perturbations normal to the plane of the bilayer, a membrane can transduce hair motion at frequencies below the hair’s characteristic frequency, and bilayers formed between polymerized hydrogel volumes exhibit a higher sensing currents than those formed between liquid aqueous volumes. Finally, measurements of sensitivity (5-35 pA m-1 s-1) and minimum (4.0-0.6 m s-1) and maximum (28-13 m s-1) sensing thresholds to airflow are performed for the first time, and we observe maximum electrical power (˜65 pW) in the membrane occurs for combinations of slower airflow and higher voltage. These results highlight that along with the dimensions of the hair and the compositions of the aqueous volumes, sensing performance can be tuned with applied voltage.

  12. A COMPOSITE HOLLOW FIBER MEMBRANE-BASED PERVAPORATION PROCESS FOR SEPARATION OF VOCS FROM AQUEOUS SURFACTANT SOLUTIONS. (R825511C027)

    EPA Science Inventory

    The separation and recovery of VOCs from surfactant-containing aqueous solutions by a composite hollow fiber membrane-based pervaporation process has been studied. The process employed hydrophobic microporous polypropylene hollow fibers having a thin plasma polymerized silicon...

  13. Fluid Inclusion Gas Analysis

    DOE Data Explorer

    Dilley, Lorie

    2013-01-01

    Fluid inclusion gas analysis for wells in various geothermal areas. Analyses used in developing fluid inclusion stratigraphy for wells and defining fluids across the geothermal fields. Each sample has mass spectrum counts for 180 chemical species.

  14. A note on the coating of an inclined plane in the presence of soluble surfactant.

    PubMed

    Edmonstone, B D; Matar, O K; Craster, R V

    2006-01-01

    We consider the flow of a thin liquid film coating an inclined plane in the presence of a soluble surfactant. A two-dimensional three-equation model is derived using lubrication theory in the rapid diffusion limit and then used to investigate the stability of the fluid height and the surfactant surface and bulk concentrations. We present solutions for an insoluble surfactant system, which are then contrasted with those obtained for a system containing a soluble surfactant; both transient growth and fully nonlinear two-dimensional simulation results are discussed. Our results indicate that the characteristics of the fingering phenomena which accompany the flow are altered by the effects of solubility. In particular, we find that these effects de-stabilise the system further over an intermediate range of surfactant solubility.

  15. A Quantitative Analysis of Brain Soluble Tau and the Tau Secretion Factor.

    PubMed

    Han, Pengcheng; Serrano, Geidy; Beach, Thomas G; Caselli, Richard J; Yin, Junxiang; Zhuang, Ningning; Shi, Jiong

    2017-01-09

    Neurofibrillary tangles (NFTs) represent products of insoluble tau protein in the brains of patients with Alzheimer disease (AD). The cerebrospinal fluid (CSF) tau level is a biomarker in AD diagnosis. The soluble portion of tau protein in brain parenchyma is presumably the source for CSF tau but this has not previously been quantified. We measured CSF tau and soluble brain tau at autopsy in temporal and frontal brain tissue samples from 7 cognitive normal, 12 mild cognitively impaired, and 19 AD subjects. Based on the measured brain soluble tau, we calculated the whole brain tau load and estimated tau secretion factor. Our results suggest that the increase in NFT in AD is likely attributable to post-translational processes; the increase in CSF tau in AD patients is due to an accelerated carrier-based secretion. Moreover, cognitive dysfunction assessed by final Mini-Mental State Examination scores correlated with the secretion factor but not with the soluble tau.

  16. Experiments of CO2 Solubility in the Synthetic Brine from the Erdos Basin, China

    NASA Astrophysics Data System (ADS)

    Wang, L.; Yu, Q.

    2015-12-01

    Solubility trapping of CO2 in saline aquifers is accepted to be the promising method in terms of carbon capture and storage (CCS). CO2 solubility at geological sequestration conditions is of great significance in evaluating the carbon capture potential of brine formation. Unfortunately, most CO2 solubility studies focus mainly on single-salt solutions, and only sparse literature exist for the data of CO2 solubility in aqueous solutions containing the mixture of K+, Na+, Ca2+ and Mg2+. To fill the research gap, an experimental investigation on the CO2 solubility in the synthetic brine is carried out. The samples were extracted through the injection wells of the Shenhua Carbon Capture and Storage project in the Erdos Basin located in northern China. The proportion of K+, Na+, Ca2+ and Mg2+ was determined by chemical analysis of the samples in the aquifers. The synthetic brine is used in this study, and the experimental process were improved to lower the risk of penetration of the supercritical fluid. Solubility data were measured over the temperature and pressure ranges of 318-348 K and 8-11 MPa. In the range studied, the average absolute deviation of CO2 solubility between literature and experimental results was 2.7%, and the maximum absolute deviation was less than 5.4%. Krichevsky-Kasarnovsky (KK) equation was established to analyze the experimental data and the effect of different ions on CO2 solubility was quantified using an optimization process. The liner fit between the CO2 solubility and mixed ion concentration is satisfied with correlation coefficient of 0.91. The proposed model and experimental data therefore possess broad adaptability to geological carbon storage. This ambiguity in the mechanism of the ion effect drives our efforts toward a better understanding of the factors controlling CO2 solubility in formation brine.

  17. [Removal of CO2 from simulated flue gas of power plants by membrane-based gas absorption processes].

    PubMed

    Yang, Ming-Fen; Fang, Meng-Xiang; Zhang, Wei-Feng; Wang, Shu-Yuan; Xu, Zhi-Kang; Luo, Zhong-Yang; Cen, Ke-Fa

    2005-07-01

    Three typical absorbents such as aqueous of aminoacetic acid potassium (AAAP), monoethanolamine (MEA) and methyldiethanolamine(MDEA) are selected to investigate the performance of CO2 separation from flue gas via membrane contactors made of hydrophobic hollow fiber polypropylene porous membrane. Impacts of absorbents, concentrations and flow rates of feeding gas and absorbent solution, cyclic loading of CO2 on the removal rate and the mass transfer velocity of CO2 are discussed. The results demonstrate that the mass transfer velocity was 7.1 mol x (m2 x s)(-1) for 1 mol x L(-1) MEA with flow rate of 0.1 m x s(-1) and flue gas with that of 0.211 m x s(-1). For 1 mol L(-1) AAAP with flow rate of 0.05 m x s(-1) and flue gas of 0.211 m x s(-1), CO2 removal rate (eta) was 93.2 % and eta was 98% for 4 mol x L(-1) AAAP under the same conditions. AAAP being absorbent, eta was higher than 90% in a wider range of concentrations of CO2. It indicates that membrane-based absorption process is a widely-applied and promising way of CO2 removal from flue gas of power plants, which not only appropriates for CO2 removal of flue gas of widely-used PF and NGCC, but also for that of flue gas of IGCC can be utilized widely in future.

  18. A Nanoporous Alumina Membrane Based Electrochemical Biosensor for Histamine Determination with Biofunctionalized Magnetic Nanoparticles Concentration and Signal Amplification.

    PubMed

    Ye, Weiwei; Xu, Yifan; Zheng, Lihao; Zhang, Yu; Yang, Mo; Sun, Peilong

    2016-10-22

    Histamine is an indicator of food quality and indispensable in the efficient functioning of various physiological systems. Rapid and sensitive determination of histamine is urgently needed in food analysis and clinical diagnostics. Traditional histamine detection methods require qualified personnel, need complex operation processes, and are time-consuming. In this study, a biofunctionalized nanoporous alumina membrane based electrochemical biosensor with magnetic nanoparticles (MNPs) concentration and signal amplification was developed for histamine determination. Nanoporous alumina membranes were modified by anti-histamine antibody and integrated into polydimethylsiloxane (PDMS) chambers. The specific antibody modified MNPs were used to concentrate histamine from samples and transferred to the antibody modified nanoporous membrane. The MNPs conjugated to histamine were captured in the nanopores via specific reaction between histamine and anti-histamine antibody, resulting in a blocking effect that was amplified by MNPs in the nanopores. The blockage signals could be measured by electrochemical impedance spectroscopy across the nanoporous alumina membrane. The sensing platform had great sensitivity and the limit of detection (LOD) reached as low as 3 nM. This biosensor could be successfully applied for histamine determination in saury that was stored in frozen conditions for different hours, presenting a potentially novel, sensitive, and specific sensing system for food quality assessment and safety support.

  19. A Nanoporous Alumina Membrane Based Electrochemical Biosensor for Histamine Determination with Biofunctionalized Magnetic Nanoparticles Concentration and Signal Amplification

    PubMed Central

    Ye, Weiwei; Xu, Yifan; Zheng, Lihao; Zhang, Yu; Yang, Mo; Sun, Peilong

    2016-01-01

    Histamine is an indicator of food quality and indispensable in the efficient functioning of various physiological systems. Rapid and sensitive determination of histamine is urgently needed in food analysis and clinical diagnostics. Traditional histamine detection methods require qualified personnel, need complex operation processes, and are time-consuming. In this study, a biofunctionalized nanoporous alumina membrane based electrochemical biosensor with magnetic nanoparticles (MNPs) concentration and signal amplification was developed for histamine determination. Nanoporous alumina membranes were modified by anti-histamine antibody and integrated into polydimethylsiloxane (PDMS) chambers. The specific antibody modified MNPs were used to concentrate histamine from samples and transferred to the antibody modified nanoporous membrane. The MNPs conjugated to histamine were captured in the nanopores via specific reaction between histamine and anti-histamine antibody, resulting in a blocking effect that was amplified by MNPs in the nanopores. The blockage signals could be measured by electrochemical impedance spectroscopy across the nanoporous alumina membrane. The sensing platform had great sensitivity and the limit of detection (LOD) reached as low as 3 nM. This biosensor could be successfully applied for histamine determination in saury that was stored in frozen conditions for different hours, presenting a potentially novel, sensitive, and specific sensing system for food quality assessment and safety support. PMID:27782087

  20. Membrane-based energy efficient dewatering of microalgae in biofuels production and recovery of value added co-products.

    PubMed

    Bhave, Ramesh; Kuritz, Tanya; Powell, Lawrence; Adcock, Dale

    2012-05-15

    The objective of this paper is to describe the use of membranes for energy efficient biomass harvesting and dewatering. The dewatering of Nannochloropsis sp. was evaluated with polymeric hollow fiber and tubular inorganic membranes to demonstrate the capabilities of a membrane-based system to achieve microalgal biomass of >150 g/L (dry wt.) and ∼99% volume reduction through dewatering. The particle free filtrate containing the growth media is suitable for recycle and reuse. For cost-effective processing, hollow fiber membranes can be utilized to recover 90-95% media for recycle. Tubular membranes can provide additional media and water recovery to achieve target final concentrations. Based on the operating conditions used in this study and taking into scale-up considerations, an integrated hollow fiber-tubular membrane system can process microalgal biomass with at least 80% lower energy requirement compared to traditional processes. Backpulsing was found to be an effective flux maintenance strategy to minimize flux decline at high biomass concentration. An effective chemical cleaning protocol was developed for regeneration of fouled membranes.

  1. Biopolymer-induced calcium phosphate scaling in membrane-based water treatment systems: Langmuir model films studies.

    PubMed

    Dahdal, Yara N; Oren, Yoram; Schwahn, Dietmar; Pipich, Vitaliy; Herzberg, Moshe; Ying, Wang; Kasher, Roni; Rapaport, Hanna

    2016-07-01

    Biofouling and scaling on reverse osmosis (RO) or nanofiltration (NF) membranes during desalination of secondary and tertiary effluents pose an obstacle that limits the reuse of wastewater. In this study we explored the mineral scaling induced by biopolymers originated from bacterial biofilms: bovine serum albumin (BSA), fibrinogen, lysozyme and alginic acid, as well as an extracts of extracellular polymeric substances (EPS) from bio-fouled RO membranes from wastewater treatment facility. Mineralization studies were performed on Langmuir films of the biopolymers deposited at the interface of a solution simulating RO desalination of secondary-treated wastewater effluents. All studied biopolymers and EPS induced heterogeneous mineralization of mainly calcium phosphate. Using IR spectroscopy coupled with systematic quantitative analysis of the surface pressure versus molecular-area isotherms, we determined the mineralization tendencies of the biopolymers to be in the order of: fibrinogen>lysozyme>BSA>alginic acid. The biopolymers and EPS studied here were found to be accelerators of calcium-phosphate mineralization. This study demonstrates the utilization of Langmuir surface-pressure area isotherms and a model solution in quantitatively assessing the mineralization tendencies of various molecular components of EPS in context of membrane-based water treatment systems.

  2. Porous polymer composite membrane based nanogenerator: A realization of self-powered wireless green energy source for smart electronics applications

    NASA Astrophysics Data System (ADS)

    Ghosh, Sujoy Kumar; Sinha, Tridib Kumar; Mahanty, Biswajit; Jana, Santanu; Mandal, Dipankar

    2016-11-01

    An efficient, flexible and unvaryingly porous polymer composite membrane based nanogenerator (PPCNG) without any electrical poling treatment has been realised as wireless green energy source to power up smart electronic gadgets. Owing to self-polarized piezo- and ferro-electretic phenomenon of in situ platinum nanoparticles (Pt-NPs) doped porous poly(vinylidenefluoride-co-hexafluoropropylene)-membrane, a simple, inexpensive and scalable PPCNG fabrication is highlighted. The molecular orientations of the -CH2/-CF2 dipoles that cause self-polarization phenomenon has been realized by angular dependent near edge X-ray absorption fine structure spectroscopy. The square-like hysteresis loop with giant remnant polarization, Pr ˜ 68 μC/cm2 and exceptionally high piezoelectric charge coefficient, d33 ˜ - 836 pC/N promises a best suited ferro- and piezo-electretic membrane. The PPCNG exhibits a high electrical throughput such as, ranging from 2.7 V to 23 V of open-circuit voltage (Voc) and 2.9 μA to 24.7 μA of short-circuit current (Isc) under 0.5 MPa to 4.3 MPa of imparted stress amplitude by periodic human finger motion. The harvested mechanical and subsequent electrical energy by PPCNG is shown to transfer wirelessly via visible and infrared transmitter-receiver systems, where 17% and 49% of wireless power transfer efficiency, respectively, has been realized to power up several consumer electronics.

  3. Membrane-Based Energy Efficient Dewatering of Microalgae in Biofuels Production and Recovery of Value Added Co-Products

    SciTech Connect

    Bhave, Ramesh R; Kuritz, Tanya; Powell, Lawrence E; Adcock, Kenneth Dale

    2012-01-01

    The objective of this paper is to describe the use of membranes for energy efficient biomass harvesting and dewatering. We have evaluated the dewatering of Nannochloropsis sp. with polymeric hollow fiber and tubular inorganic membranes to demonstrate the capabilities of a membrane-based system to achieve microalgal biomass of >150 g/L (dry wt.) and ~99% volume reduction through dewatering. The particle free filtrate containing the growth media is suitable for recycle and reuse. For cost-effective processing, hollow fiber membranes can be utilized to recover 90-95% media for recycle. Tubular membranes can provide additional media and water recovery to achieve target final concentrations. Based on the operating conditions used in this study and taking into scale-up considerations, it can be shown that an integrated hollow fiber-tubular membrane system can process microalgal biomass with at least 80% lower energy requirement compared to traditional processes. Backpulsing was found to be an effective flux maintenance strategy to minimize flux decline at high biomass concentration. An effective chemical cleaning protocol was developed for regeneration of fouled membranes.

  4. Membrane-Based Air Composition Control for Light-Duty Diesel Vehicles: A Benefit and Cost Assessment

    SciTech Connect

    K. Stork; R. Poola

    1998-10-01

    This report presents the methodologies and results of a study conducted by Argonne National Laboratory (Argonne) to assess the benefits and costs of several membrane-based technologies. The technologies evaluated will be used in automotive emissions-control and performance-enhancement systems incorporated into light-duty diesel vehicle engines. Such engines are among the technologies that are being considered to power vehicles developed under the government-industry Partnership for a New Generation of Vehicles (PNGV). Emissions of nitrogen oxides (NO{sub x}) from diesel engines have long been considered a barrier to use of diesels in urban areas. Recently, particulate matter (PM) emissions have also become an area of increased concern because of new regulations regarding emissions of particulate matter measuring 2.5 micrometers or less (PM{sub 2.5}). Particulates are of special concern for diesel engines in the PNGV program; the program has a research goal of 0.01 gram per mile (g/mi) of particulate matter emissions under the Federal Test Procedure (FTP) cycle. This extremely low level (one-fourth the level of the Tier II standard) could threaten the viability of using diesel engines as stand-alone powerplants or in hybrid-electric vehicles. The techniques analyzed in this study can reduce NO{sub x} and particulate emissions and even increase the power density of the diesel engines used in light-duty diesel vehicles.

  5. Experimental and theoretical studies on physico-chemical parameters affecting the solubility of phosphogypsum.

    PubMed

    Papanicolaou, Fanos; Antoniou, Stella; Pashalidis, Ioannis

    2009-10-01

    Phosphogypsum is a waste by-product of the phosphate fertilizer industry, which is usually disposed in the environment because of its restricted use in industrial applications. Physico-chemical conditions existing in stack fluids and leachates are of major importance and determine solubility and redox stability of phosphogypsum, as well as radionuclide release from stacks to terrestrial environments. The aim of this study is to assess the effect of key parameters (e.g. ionic strength, temperature, pH) on the solubility of phosphogypsum. Phosphogypsum sampling and in-situ measurements were carried out at a coastal stack in Cyprus, solubility experiments were performed in simulated laboratory systems and thermodynamic calculations by means of MINTEQA2, an equilibrium speciation model. Generally, increasing ionic strength and temperature leads to increased phosphogypsum solubility, with the former being much more effective. The increased solubility of phosphogypsum in saline solutions is attributed solely to ionic strength effects on the activity of ionic species in solution and no solid phase transformations could be observed. The effect of pH on phosphogypsum solubility seems to be insignificant at least in a pH range between 4 and 8. Regarding uranium levels, there is a strong correlation between salinity and uranium concentration and linear correlation between phosphogypsum solubility and uranium levels in stack solutions, indicating the incorporation of uranium into the gypsum lattice and the formation of a solid solution.

  6. Wettability, water sorption and water solubility of seven silicone elastomers used for maxillofacial prostheses.

    PubMed

    Hulterström, Anna Karin; Berglund, Anders; Ruyter, I Eystein

    2008-01-01

    The wettability, water sorption and solubility of silicone elastomers used for maxillofacial prostheses were studied. The hypothesis was, that a material that has absorbed water would show an increase in the wettability and thus also the surface free energy of the material. Seven silicone elastomers, both addition- and condensation type polymers, were included. Five specimens of each material were subjected to treatment according to ISO standards 1567:1999 and 10477: 2004 for water sorption and solubility. The volumes of the specimens were measured according to Archimedes principle. The contact angle was measured with a contact angle goniometer at various stages of the sorption/solubility test. Wettability changed over the test period, but not according to theory. The addition type silicones showed little or no sorption and solubility, but two of the condensation type polymers tested had a significant sorption and solubility. This study showed that condensation type polymers may show too large volumetric changes when exposed to fluids, and therefore should no longer be used in prosthetic devices. The results of this study also suggests that it might be of interest to test sorption and solubility of materials that are to be implanted, since most of the materials had some solubility.

  7. Solubility of small-chain carboxylic acids in supercritical carbon dioxide

    DOE PAGES

    Sparks, Darrell L.; Estevez, L. Antonio; Hernandez, Rafael; ...

    2010-07-08

    The solubility of heptanoic acid and octanoic acid in supercritical carbon dioxide has been determined at temperatures of (313.15, 323.15, and 333.15) K over a pressure range of (8.5 to 30.0) MPa, depending upon the solute. The solubility of heptanoic acid ranged from a solute concentration of (0.08 ± 0.03) kg • m-3 (T = 323.15 K, p = 8.5 MPa) to (147 ± 0.2) kg • m-3 (T = 323.15 K, p = 20.0 MPa). The lowest octanoic acid solubility obtained was a solute concentration of (0.40 ± 0.1) kg • m-3 (T = 333.15 K, p = 10.0more » MPa), while the highest solute concentration was (151 ± 2) kg • m-3 (T = 333.15 K, p = 26.7 MPa). In addition, solubility experiments were performed for nonanoic acid in supercritical carbon dioxide at 323.15 K and pressures of (10.0 to 30.0) MPa to add to the solubility data previously published by the authors. In general, carboxylic acid solubility increased with increasing solvent density. The results also showed that the solubility of the solutes decreased with increasing molar mass at constant supercritical-fluid density. Additionally, the efficacy of Chrastil's equation and other density-based models was evaluated for each fatty acid.« less

  8. Solubility of small-chain carboxylic acids in supercritical carbon dioxide

    SciTech Connect

    Sparks, Darrell L.; Estevez, L. Antonio; Hernandez, Rafael; McEwen, Jason; French, Todd

    2010-07-08

    The solubility of heptanoic acid and octanoic acid in supercritical carbon dioxide has been determined at temperatures of (313.15, 323.15, and 333.15) K over a pressure range of (8.5 to 30.0) MPa, depending upon the solute. The solubility of heptanoic acid ranged from a solute concentration of (0.08 ± 0.03) kg • m-3 (T = 323.15 K, p = 8.5 MPa) to (147 ± 0.2) kg • m-3 (T = 323.15 K, p = 20.0 MPa). The lowest octanoic acid solubility obtained was a solute concentration of (0.40 ± 0.1) kg • m-3 (T = 333.15 K, p = 10.0 MPa), while the highest solute concentration was (151 ± 2) kg • m-3 (T = 333.15 K, p = 26.7 MPa). In addition, solubility experiments were performed for nonanoic acid in supercritical carbon dioxide at 323.15 K and pressures of (10.0 to 30.0) MPa to add to the solubility data previously published by the authors. In general, carboxylic acid solubility increased with increasing solvent density. The results also showed that the solubility of the solutes decreased with increasing molar mass at constant supercritical-fluid density. Additionally, the efficacy of Chrastil's equation and other density-based models was evaluated for each fatty acid.

  9. Statistical investigation of simulated fed intestinal media composition on the equilibrium solubility of oral drugs.

    PubMed

    Zhou, Zhou; Dunn, Claire; Khadra, Ibrahim; Wilson, Clive G; Halbert, Gavin W

    2017-03-01

    Gastrointestinal fluid is a complex milieu and it is recognised that gut drug solubility is different to that observed in simple aqueous buffers. Simulated gastrointestinal media have been developed covering fasted and fed states to facilitate in vitro prediction of gut solubility and product dissolution. However, the combination of bile salts, phospholipids, fatty acids and proteins in an aqueous buffered system creates multiple phases and drug solubility is therefore a complex interaction between these components, which may create unique environments for each API. The impact on solubility can be assessed through a statistical design of experiment (DoE) approach, to determine the influence and relationships between factors. In this paper DoE has been applied to fed simulated gastrointestinal media consisting of eight components (pH, bile salt, lecithin, sodium oleate, monoglyceride, buffer, salt and pancreatin) using a two level D-optimal design with forty-four duplicate measurements and four centre points. The equilibrium solubility of a range of poorly soluble acidic (indomethacin, ibuprofen, phenytoin, valsartan, zafirlukast), basic (aprepitant, carvedilol, tadalafil, bromocriptine) and neutral (fenofibrate, felodipine, probucol, itraconazole) drugs was investigated. Results indicate that the DoE provides equilibrium solubility values that are comparable to literature results for other simulated fed gastrointestinal media systems or human intestinal fluid samples. For acidic drugs the influence of pH predominates but other significant factors related to oleate and bile salt or interactions between them are present. For basic drugs pH, oleate and bile salt have equal significance along with interactions between pH and oleate and lecithin and oleate. Neutral drugs show diverse effects of the media components particularly with regard to oleate, bile salt, pH and lecithin but the presence of monoglyceride, pancreatin and buffer have significant but smaller effects

  10. Membrane-based microarrays

    NASA Astrophysics Data System (ADS)

    Dawson, Elliott P.; Hudson, James; Steward, John; Donnell, Philip A.; Chan, Wing W.; Taylor, Richard F.

    1999-11-01

    Microarrays represent a new approach to the rapid detection and identification of analytes. Studies to date have shown that the immobilization of receptor molecules (such as DNA, oligonucleotides, antibodies, enzymes and binding proteins) onto silicon and polymeric substrates can result in arrays able to detect hundreds of analytes in a single step. The formation of the receptor/analyte complex can, itself, lead to detection, or the complex can be interrogated through the use of fluorescent, chemiluminescent or radioactive probes and ligands.

  11. Fluid mechanics in fluids at rest.

    PubMed

    Brenner, Howard

    2012-07-01

    Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity v(v). The term "compressibility" as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci. 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and gases.

  12. Fluid mechanics in fluids at rest

    NASA Astrophysics Data System (ADS)

    Brenner, Howard

    2012-07-01

    Using readily available experimental thermophoretic particle-velocity data it is shown, contrary to current teachings, that for the case of compressible flows independent dye- and particle-tracer velocity measurements of the local fluid velocity at a point in a flowing fluid do not generally result in the same fluid velocity measure. Rather, tracer-velocity equality holds only for incompressible flows. For compressible fluids, each type of tracer is shown to monitor a fundamentally different fluid velocity, with (i) a dye (or any other such molecular-tagging scheme) measuring the fluid's mass velocity v appearing in the continuity equation and (ii) a small, physicochemically and thermally inert, macroscopic (i.e., non-Brownian), solid particle measuring the fluid's volume velocity vv. The term “compressibility” as used here includes not only pressure effects on density, but also temperature effects thereon. (For example, owing to a liquid's generally nonzero isobaric coefficient of thermal expansion, nonisothermal liquid flows are to be regarded as compressible despite the general perception of liquids as being incompressible.) Recognition of the fact that two independent fluid velocities, mass- and volume-based, are formally required to model continuum fluid behavior impacts on the foundations of contemporary (monovelocity) fluid mechanics. Included therein are the Navier-Stokes-Fourier equations, which are now seen to apply only to incompressible fluids (a fact well-known, empirically, to experimental gas kineticists). The findings of a difference in tracer velocities heralds the introduction into fluid mechanics of a general bipartite theory of fluid mechanics, bivelocity hydrodynamics [Brenner, Int. J. Eng. Sci.10.1016/j.ijengsci.2012.01.006 54, 67 (2012)], differing from conventional hydrodynamics in situations entailing compressible flows and reducing to conventional hydrodynamics when the flow is incompressible, while being applicable to both liquids and

  13. Rational formulation development and in vitro assessment of SMEDDS for oral delivery of poorly water soluble drugs.

    PubMed

    Sprunk, Angela; Strachan, Clare J; Graf, Anja

    2012-08-15

    The aims of this study were to formulate a self-microemulsifying drug delivery system (SMEDDS) by a rational formulation approach using mixture experimental design and to derive general concepts that make the development of such systems more feasible. Various types of oils and surfactants were systematically combined and the phase behaviour upon dilution with simulated gastric fluid examined by construction of phase diagrams. The systems solubilising the highest amount of simulated gastric fluid in the continuous microemulsion area were selected for investigation and optimisation of drug solubility. Simvastatin was added as a poorly water-soluble, lipophilic model drug. Two different mixture experimental designs using D-optimal design were set up and used to investigate the solubility of simvastatin in the SMEDDS before and after dilution with simulated gastric fluid respectively. The solubility in each mixture region was analysed by fitting quadratic models using partial least squares analysis. The established models revealed the influence of mixture components on phase behaviour and drug solubility and gave the rationale for formulation optimisation. This study demonstrated that the development of complex self-emulsifying formulations with sufficient solubilisation capacity for poorly water-soluble drugs upon oral administration can be more feasible when using experimental design.

  14. Membrane-based air composition control for light-duty diesel vehicles : a benefit and cost assessment.

    SciTech Connect

    Poola, R.; Stork, K.

    1998-11-09

    This report presents the methodologies and results of a study conducted by Argonne National Laboratory (Argonne) to assess the benefits and costs of several membrane-based technologies. The technologies evaluated will be used in automotive emissions-control and performance-enhancement systems incorporated into light-duty diesel vehicle engines. Such engines are among the technologies that are being considered to power vehicles developed under the government-industry Partnership for a New Generation of Vehicles (PNGV). Emissions of nitrogen oxides (NO{sub x}) from diesel engines have long been considered a barrier to use of diesels in urban areas. Recently, particulate matter (PM) emissions have also become an area of increased concern because of new regulations regarding emissions of particulate matter measuring 2.5 micrometers or less (PM2.5). Particulates are of special concern for diesel engines in the PNGV program; the program has a research goal of 0.01 gram per mile (g/mi) of particulate matter emissions under the Federal Test Procedure (FTP) cycle. This extremely low level (one-fourth the level of the Tier II standard) could threaten the viability of using diesel engines as stand-alone powerplants or in hybrid-electric vehicles. The techniques analyzed in this study can reduce NO{sub x} and particulate emissions and even increase the power density of the diesel engines used in light-duty diesel vehicles. For nearly a decade, Argonne has been evaluating membrane-based methods to control the composition of air used in combustion. Membranes are the only practical method of modifying air composition for on-board use. The applicability of the technique depends strongly on both the technical and economic feasibility of implementing it on a vehicle. Over the past 10 years, significant technical advances have been made in the development of air-separation membranes. Researchers have developed and commercialized novel membrane materials that can efficiently separate

  15. Method to Estimate the Dissolved Air Content in Hydraulic Fluid

    NASA Technical Reports Server (NTRS)

    Hauser, Daniel M.

    2011-01-01

    In order to verify the air content in hydraulic fluid, an instrument was needed to measure the dissolved air content before the fluid was loaded into the system. The instrument also needed to measure the dissolved air content in situ and in real time during the de-aeration process. The current methods used to measure the dissolved air content require the fluid to be drawn from the hydraulic system, and additional offline laboratory processing time is involved. During laboratory processing, there is a potential for contamination to occur, especially when subsaturated fluid is to be analyzed. A new method measures the amount of dissolved air in hydraulic fluid through the use of a dissolved oxygen meter. The device measures the dissolved air content through an in situ, real-time process that requires no additional offline laboratory processing time. The method utilizes an instrument that measures the partial pressure of oxygen in the hydraulic fluid. By using a standardized calculation procedure that relates the oxygen partial pressure to the volume of dissolved air in solution, the dissolved air content is estimated. The technique employs luminescent quenching technology to determine the partial pressure of oxygen in the hydraulic fluid. An estimated Henry s law coefficient for oxygen and nitrogen in hydraulic fluid is calculated using a standard method to estimate the solubility of gases in lubricants. The amount of dissolved oxygen in the hydraulic fluid is estimated using the Henry s solubility coefficient and the measured partial pressure of oxygen in solution. The amount of dissolved nitrogen that is in solution is estimated by assuming that the ratio of dissolved nitrogen to dissolved oxygen is equal to the ratio of the gas solubility of nitrogen to oxygen at atmospheric pressure and temperature. The technique was performed at atmospheric pressure and room temperature. The technique could be theoretically carried out at higher pressures and elevated

  16. The Solubility of Diopside in Water at 10 to 15 kbar and 650 to 900 C

    NASA Astrophysics Data System (ADS)

    Macris, C. A.; Manning, C. E.

    2005-12-01

    Subduction zone fluids play a critical role in mass transfer and mantle-wedge metasomatism, yet little is known about their composition and chemical behavior. One way to better understand these important fluids is to investigate the solubility of minerals at subduction zone conditions. The solubility of diopside in H2O was measured at 10 to 15 kbar, 650 to 900 °C using a piston-cylinder apparatus with NaCl-graphite furnaces. A single gem-quality diopside crystal was placed in an inner Pt capsule, which then was perforated to allow fluid ingress and added with H2O to an outer Pt capsule, which was then sealed. The solubility was determined by the weight loss of the diopside crystals. All charges were carefully examined by SEM for composition and textural characteristics of quench material. SEM analysis revealed that in several experiments small diopside crystals nucleated and grew in the outer capsule or on the walls of the inner capsule due to fluid convection within the charge. These experiments yielded erroneously high solubilities and were omitted from final plots and equation calculations. Diopside was found to dissolve incongruently to forsterite + dissolved species at all conditions investigated. The forsterite occurs as euhedral crystals in pits etched from the diopside grain covering less than 5% of its surface. In addition, long thin wollastonite blades and a layer of SiO2 "mud" form upon quenching of the run. Experiments at 700 °C and varying times showed that diopside plus forsterite plus fluid reached equilibrium by 12 hours. The solubility of diopside + forsterite in H2O increases with increasing pressure and temperature. At 10 kbar, solubility increases from 0.004 molal at 650 °C to 0.012 molal at 900 °C. At 800 °C and 10 to 15 kbar, solubility increases from 0.008 to 0.015 molal. These preliminary data yield the equation: log mdi+fo = -0.7539 + -2135.7/T + 0.6355P, where T is in K and P is in GPa. Because temperature enhances solubility more

  17. Fluid transport container

    DOEpatents

    DeRoos, Bradley G.; Downing, Jr., John P.; Neal, Michael P.

    1995-01-01

    An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitment for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container.

  18. Fluid transport container

    DOEpatents

    DeRoos, B.G.; Downing, J.P. Jr.; Neal, M.P.

    1995-11-14

    An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitting for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container. 13 figs.

  19. Drug Solubility: Importance and Enhancement Techniques

    PubMed Central

    Savjani, Ketan T.; Gajjar, Anuradha K.; Savjani, Jignasa K.

    2012-01-01

    Solubility, the phenomenon of dissolution of solute in solvent to give a homogenous system, is one of the important parameters to achieve desired concentration of drug in systemic circulation for desired (anticipated) pharmacological response. Low aqueous solubility is the major problem encountered with formulation development of new chemical entities as well as for the generic development. More than 40% NCEs (new chemical entities) developed in pharmaceutical industry are practically insoluble in water. Solubility is a major challenge for formulation scientist. Any drug to be absorbed must be present in the form of solution at the site of absorption. Various techniques are used for the enhancement of the solubility of poorly soluble drugs which include physical and chemical modifications of drug and other methods like particle size reduction, crystal engineering, salt formation, solid dispersion, use of surfactant, complexation, and so forth. Selection of solubility improving method depends on drug property, site of absorption, and required dosage form characteristics. PMID:22830056

  20. pH-Dependent Solubility and Dissolution Behavior of Carvedilol--Case Example of a Weakly Basic BCS Class II Drug.

    PubMed

    Hamed, Rania; Awadallah, Areeg; Sunoqrot, Suhair; Tarawneh, Ola; Nazzal, Sami; AlBaraghthi, Tamadur; Al Sayyad, Jihan; Abbas, Aiman

    2016-04-01

    The objective of this study was to investigate the pH-dependent solubility and dissolution of weakly basic Biopharmaceutical Classification Systems (BCS) class II drugs, characterized by low solubility and high permeability, using carvedilol, a weak base with a pK a value of 7.8, as a model drug. A series of solubility and in vitro dissolution studies was carried out using media that simulate the gastric and intestinal fluids and cover the physiological pH range of the GI from 1.2 to 7.8. The effect of ionic strength, buffer capacity, and buffer species of the dissolution media on the solubility and dissolution behavior of carvedilol was also investigated. The study revealed that carvedilol exhibited a typical weak base pH-dependent solubility profile with a high solubility at low pH (545.1-2591.4 μg/mL within the pH range 1.2-5.0) and low solubility at high pH (5.8-51.9 μg/mL within the pH range 6.5-7.8). The dissolution behavior of carvedilol was consistent with the solubility results, where carvedilol release was complete (95.8-98.2% released within 60 min) in media simulating the gastric fluid (pH 1.2-5.0) and relatively low (15.9-86.2% released within 240 min) in media simulating the intestinal fluid (pH 6.5-7.8). It was found that the buffer species of the dissolution media may influence the solubility and consequently the percentage of carvedilol released by forming carvedilol salts of varying solubilities. Carvedilol solubility and dissolution decreased with increasing ionic strength, while lowering the buffer capacity resulted in a decrease in carvedilol solubility and dissolution rate.

  1. Metal Oxide Solubility and Molten Salt Corrosion.

    DTIC Science & Technology

    1982-03-29

    METAL OXIDE SOLUBILITY AND MOLTEN SALT CORROSION.(U) MAR 82 K H STERN UNCLASSI E DL R L-4772NL EL .2. MICROCOPY RESOLUTION TEST CHART NATIONAL BURALU...METAL OXIDE SOLUBILITY AND MOLTEN SALT Interim report on a continuing CORROSION NRL problem. S. PERFORMING a4. REPORT NUMlER 7. AuTtwORr) S. CONTRACT OR...EQUILIBRIA AND OXIDE SOLUTION RELATIONS IN MOLTEN SALTS ............................................. 2 IV. METHODS FOR DETERMINING SOLUBILITIES

  2. Rare earth element budgets in subduction-zone fluids

    NASA Astrophysics Data System (ADS)

    Tsay, A.; Zajacz, Z.; Sanchez-Valle, C.

    2012-12-01

    Subduction zone fluids play a fundamental role in the geochemical cycle of the Earth. The nature and composition of these fluids are determined by complex processes and still poorly understood. As a result of a variety of metasomatic and partial melting events, arc-related magmas display a typical trace element abundance spectrum, in which the rare earth elements' (REE) signature is an important record of petrogenetic processes. Therefore, investigating the behavior of REE in fluids at high pressure (P) and temperature (T) conditions is crucial for constraining fluid composition, as well as understanding subduction-zone processes in general. However, up to date, the experimental studies on REE solubility and speciation are limited to quite low P-T conditions (300 °C, saturated water vapor pressure) [1]. The theoretical predictions of the stability of REE complexes have been performed up to 350 °C [2] and 1000 °C, 0.5 GPa [3] by the extrapolation of thermodynamic data obtained at ambient conditions. In this study we present new experimental data on REE silicate (REE2Si2O7) solubility in aqueous quartz saturated fluids, containing various ligands, at conditions relevant for subducting slabs (600, 700, 800 °C, 2.6 GPa). The aim of the experiments was to investigate the relative effect of temperature and ligands on the solubility of REE. The experiments were conducted in an end-loaded piston-cylinder apparatus and the fluids were in situ sampled at P-T in the form of primary fluid inclusions in quartz [4]. The gold capsule was typically loaded with a chip of synthetic REE silicate (La,Nd,Gd,Dy,Er,Yb)2Si2O7, an aqueous fluid (~20 wt.%) and a piece of natural quartz. During the experiment (24-48 h) a thermal gradient along the capsule promoted intensive dissolution of quartz at the hottest part and precipitation of new quartz at the cooler part of the capsule, allowing the primary fluid inclusions to be trapped (~30-50 μm). Rubidium and cesium were added to the

  3. Saturated brine well treating fluids and additives therefore

    SciTech Connect

    Dobson, J.W. Jr.; Mondshine, A.T.; Mondshine, T.C.

    1989-04-18

    A well treating fluid is described, comprising a saturated aqueous saline solution, a water soluble particulate salt which is insoluble in the saturated aqueous saline solution, a xanthomonas gum, and an eicholorhydrin crosslinked hydroxypropyl starch wherein the concentration of the xanthomonas gum is from about 0l.5 kg/m/sup 3/ to about 5.7 kg/m/sup 3/ of the well treating fluid and the concentration of the epichlorohydrin crosslinked hyroxypropyl starch is from about 0.7 kg/cm/sup 3/ to about 42 kg/m/sup 3/ of the well treating fluid.

  4. Water-soluble hydrophobically associating polymers for improved oil recovery: A literature review

    SciTech Connect

    Taylor, K.C.; Nasr-El-Din, H.A.

    1995-11-01

    Water-soluble hydrophobically associating polymers are reviewed with particular emphasis on their application in improved oil recovery (IOR). These polymers are very similar to conventional water-soluble polymers used in IOR, except that they have a small number of hydrophobic groups incorporated into the polymer backbone. At levels of incorporation of less than 1 mol%, these hydrophobic groups can significantly change polymer performance. These polymers have potential for use in mobility control, drilling fluids and profile modification. This review includes synthesis, characterization, stability, rheology and flow in porous media of associating polymers in IOR are also examined. 100 refs., 2 tabs.

  5. Solubility of methane in water under natural conditions: a laboratory study. Final report, April 1, 1978-June 30, 1982

    SciTech Connect

    Blount, C.W.; Price, L.C.

    1982-06-01

    The solubility of methane in aqueous solutions has been determined over a broad range of temperature, pressure and salinities. The effect of dissolved carbon dioxide and ethane on methane solubility has been determined at 302{sup 0}F. Also the solubility of crude oil and water in methane has been determined over a broad range of temperatures and pressures. The solubility of methane is raised by increasing pressure and temperature (above about 170{sup 0}F). There is a solubility minimum near 170{sup 0}F at constant pressure and salinity. Ionic salts effectively salt methane out of solution at all concentrations investigated. The effect of the addition of small amounts of carbon dioxide or ethane to the gas dissolved in aqueous solutions is to enhance methane solubility compared to solutions without other gases. Higher concentrations of dissolved gases, depending upon the salinity and the gas involved, decrease aqueous methane solubility. The addition of carbon dioxide always increased total gas content even when reducing the concentration of methane. With increasing concentration of ethane in the dissolved gases the total gas content reaches a maximum and then both methane and total gas content decrease. Comparison of experimental methane solubilities with gas/water ratios, salinities, bottom hole temperatures and pressures of geopressure test wells suggests that some formation fluids may be near saturation, while many others seem to be undersaturated. Petroleum is soluble in methane. Increasing pressure increases the solubility of crude oil in methane gas. At an elevated pressure, which depends upon the temperature, oil and gas form a single fluid phase.

  6. Fluid fluxes from petrological record: links to mineral-fluid thermodynamics and implications for flow patterns

    NASA Astrophysics Data System (ADS)

    Dolejš, D.

    2012-04-01

    Fluid flow through the Earth's lithosphere is an inevitable consequence of fluid production during sediment compaction, prograde metamorphic reactions, and magmatic degassing, in settings ranging from subducting zones, continental crust underplating to shallow magma chambers. In addition, high buoyancy and low viscosity of aqueous fluid in a rock environment make flow universally viable and efficient. Fluids are not preserved in their pathways and much of their evidence including chemical composition is often retrieved from mineral mode, chemical, or isotopic variations. Several important links, advantages and artifacts arising from dimensional consistency and from correlations with mineral-fluid thermodynamics are worthy to revisit. The magnitude of fluid-rock interaction is measured by the fluid-rock ratio (mfl3 mr-3) or a time-integrated fluid flux (mfl3 mr-2). These two measures differ by mr, the characteristic distance of alteration or front propagation, parallel to the flow direction. As a consequence, the fluid-rock ratios depend on spatial relationships between flow direction, temperature- and pressure-gradient orientation, and alteration zone or vein geometry. The reservoir ratios, which are required in mass-balance or phase-equilibrium calculations, can still be unambiguously defined when the above variables are scaled to the flow direction. Gradients in mole amounts of reaction progress or mineral precipitated, n, per unit temperature or pressure are directly related to standard reaction enthalpy and volume, respectively. The effects of pressure are commonly assumed to be negligible. Systematic evaluation of mineral solubilities, however, reveals that (i) dn/dT is nearly identical for a variety of phases and from subduction to collisional geotherms but minerals dissolving into charged species exhibit higher solubilities, therefore, yield greater reaction progress and lower fluid fluxes along low-dT /dzgeotherms; (ii) during lateral (isobaric) flow, dn

  7. Postoperative fluid management

    PubMed Central

    Kayilioglu, Selami Ilgaz; Dinc, Tolga; Sozen, Isa; Bostanoglu, Akin; Cete, Mukerrem; Coskun, Faruk

    2015-01-01

    Postoperative care units are run by an anesthesiologist or a surgeon, or a team formed of both. Management of postoperative fluid therapy should be done considering both patients’ status and intraoperative events. Types of the fluids, amount of the fluid given and timing of the administration are the main topics that determine the fluid management strategy. The main goal of fluid resuscitation is to provide adequate tissue perfusion without harming the patient. The endothelial glycocalyx dysfunction and fluid shift to extracellular compartment should be considered wisely. Fluid management must be done based on patient’s body fluid status. Patients who are responsive to fluids can benefit from fluid resuscitation, whereas patients who are not fluid responsive are more likely to suffer complications of over-hydration. Therefore, common use of central venous pressure measurement, which is proved to be inefficient to predict fluid responsiveness, should be avoided. Goal directed strategy is the most rational approach to assess the patient and maintain optimum fluid balance. However, accessible and applicable monitoring tools for determining patient’s actual fluid need should be further studied and universalized. The debate around colloids and crystalloids should also be considered with goal directed therapies. Advantages and disadvantages of each solution must be evaluated with the patient’s specific condition. PMID:26261771

  8. Filtrates & Residues: An Experiment on the Molar Solubility and Solubility Product of Barium Nitrate.

    ERIC Educational Resources Information Center

    Wruck, Betty; Reinstein, Jesse

    1989-01-01

    Provides a two hour experiment using direct gravimetric methods to determine solubility constants. Provides methodology and sample results. Discusses the effect of the common ion on the solubility constant. (MVL)

  9. Partitioning of naturally-occurring radionuclides (NORM) in Marcellus Shale produced fluids influenced by chemical matrix.

    PubMed

    Nelson, Andrew W; Johns, Adam J; Eitrheim, Eric S; Knight, Andrew W; Basile, Madeline; Bettis, E Arthur; Schultz, Michael K; Forbes, Tori Z

    2016-04-01

    Naturally-occurring radioactive materials (NORM) associated with unconventional drilling produced fluids from the Marcellus Shale have raised environmental concerns. However, few investigations into the fundamental chemistry of NORM in Marcellus Shale produced fluids have been performed. Thus, we performed radiochemical experiments with Marcellus Shale produced fluids to understand the partitioning behavior of major radioelements of environmental health concern (uranium (U), thorium (Th), radium (Ra), lead (Pb), and polonium (Po)). We applied a novel radiotracer, (203)Pb, to understand the behavior of trace-levels of (210)Pb in these fluids. Ultrafiltration experiments indicated U, Th, and Po are particle reactive in Marcellus Shale produced fluids and Ra and Pb are soluble. Sediment partitioning experiments revealed that >99% of Ra does not adsorb to sediments in the presence of Marcellus Shale produced fluids. Further experiments indicated that although Ra adsorption is related to ionic strength, the concentrations of heavier alkaline earth metals (Ba, Sr) are stronger predictors of Ra solubility.

  10. Diamond Synthesis and Carbon Solubility in a Hydrous Granitoid System

    NASA Astrophysics Data System (ADS)

    Renfro, A.; Dobrzhinetskaya, L. P.

    2004-12-01

    An increasing number of UHP metamorphic terranes incorporated in collisional orogenic belts have been identified since the first discovery of diamonds within felsic metamorphic rocks of Kokchetav massif, Kazakhstan, extending up to ˜4000 km in length in the Dabie-SuLu-Qinling belt of China. Some have suggested that all orogenic belt diamonds formed from a carbonate or calc-alkaline melt similar to those derived from kimberlitic pipes, or alternatively that they formed from a carbon-enriched silicate melt with a granitoid bulk chemistry composition. Another group has suggested that orogenic belt diamonds crystallized from a COH-rich supercritical fluid. While the diversity of the minor components accompanying the SiO2-dominated inclusions from Kokchetav diamonds, as well as the presence of cavities bearing traces of a former fluid, suggest the idea of diamond growth from a COH fluid, a Si-rich melt as a source for diamond formation cannot be ruled out. Although many experiments were performed on diamond synthesis and on the petrology of diamond-bearing rocks, no consensus has been reached as to which of the mentioned growth media is correct to explain orogenic belt diamond formation. We report here the results of an experimental program undertaken to determine the critical point of the Si-Al-K-C-H2O system (and thus, to distinguish a melt environment from a fluid one) and to provide an understanding of how diamond is crystallized in hydrous subducted felsic continental crust. Carbon solubility in these systems was qualitatively determined based on the observed diamond growth rates. Experiments were performed at in a Walker-style multianvil apparatus at P=7 GPa and T=1500-1700° C with SiO2 ranging from 90 wt. %, imitating diamondiferous quartzite, to 62 wt. %, imitating a wide range of feldspathic diamondiferous gneisses. An additional parameter, oxygen fugacity, was also varied to test its affects on the solubility of carbon in Si-rich melt/fluid.

  11. A Membrane-Based Electro-Separation Method (MBES) for Sample Clean-Up and Norovirus Concentration

    PubMed Central

    Kang, Wei; Cannon, Jennifer L.

    2015-01-01

    Noroviruses are the leading cause of acute gastroenteritis and foodborne illnesses in the United States. Enhanced methods for detecting noroviruses in food matrices are needed as current methods are complex, labor intensive and insensitive, often resulting in inhibition of downstream molecular detection and inefficient recovery. Membrane-based electro-separation (MBES) is a technique to exchange charged particles through a size-specific dialysis membrane from one solution to another using electric current as the driving force. Norovirus has a net negative surface charge in a neutrally buffered environment, so when placed in an electric field, it moves towards the anode. It can then be separated from the cathodic compartment where the sample is placed and then collected in the anodic compartment for downstream detection. In this study, a MBES-based system was designed, developed and evaluated for concentrating and recovering murine norovirus (MNV-1) from phosphate buffer. As high as 30.8% MNV-1 migrated from the 3.5 ml sample chamber to the 1.5 ml collection chamber across a 1 μm separation membrane when 20 V was applied for 30 min using 20 mM sodium phosphate with 0.01% SDS (pH 7.5) as the electrolyte. In optimization of the method, weak applied voltage (20 V), moderate duration (30 min), and low ionic strength electrolytes with SDS addition were needed to increase virus movement efficacy. The electric field strength of the system was the key factor to enhance virus movement, which could only be improved by shortening the electrodes distance, instead of increasing system applied voltage because of virus stability. This study successfully demonstrated the norovirus mobility in an electric field and migration across a size-specific membrane barrier in sodium phosphate electrolyte. With further modification and validation in food matrixes, a novel, quick, and cost-effective sample clean-up technique might be developed to separate norovirus particles from food

  12. Calculation of Drug Solubilities by Pharmacy Students.

    ERIC Educational Resources Information Center

    Cates, Lindley A.

    1981-01-01

    A method of estimating the solubilities of drugs in water is reported that is based on a principle applied in quantitative structure-activity relationships. This procedure involves correlation of partition coefficient values using the octanol/water system and aqueous solubility. (Author/MLW)

  13. Solubility Characteristics of PCBM and C60.

    PubMed

    Boucher, David; Howell, Jason

    2016-11-10

    Empirical data indicate that several good solvents for C60 and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) have substantial polar and hydrogen-bonding components, which are not intrinsic to the structure of the C60 and PCBM molecules themselves. Functional solubility parameter (FSP) and convex solubility parameter (CSP) computations are performed on C60 and PCBM using solubility data available in the literature. The CSP and FSP results are compared to previously reported Hansen solubility parameters (HSPs) and to the parameters calculated using additive functional group contribution methods. The CSP and FSP methods confirm the anomalously large polar and hydrogen-bonding parameters, δP and δH, obtained experimentally for C60 and PCBM. This behavior, which is quite irregular given the structure of the molecules, is due to the fact that several good solvents have high δP and δH values. Thus, these irregularities are highlighted by the CSP and FSP calculations. Additional contradictory solubility characteristics are disclosed by comparing the experimental solubility parameters to a linear solvation energy relationship (LSER) model, additive functional group calculations, and COSMO-RS computations. The FSP solubility function strongly suggests that the solubility parameters do not accurately represent the cohesive energy density properties of C60 and PCBM, as intended, but rather they manifest the properties of the solvents, e.g., high δP and δH values, that are necessary to accommodate these molecules in the liquid phase.

  14. A Colorful Solubility Exercise for Organic Chemistry

    ERIC Educational Resources Information Center

    Shugrue, Christopher R.; Mentzen, Hans H., II; Linton, Brian R.

    2015-01-01

    A discovery chemistry laboratory has been developed for the introductory organic chemistry student to investigate the concepts of polarity, miscibility, solubility, and density. The simple procedure takes advantage of the solubility of two colored dyes in a series of solvents or solvent mixtures, and the diffusion of colors can be easily…

  15. Fluid sampling pump

    SciTech Connect

    Allen, P.V.; Nimberger, M.; Ward, R.L.

    1991-12-24

    This patent describes a fluid sampling pump for withdrawing pressurized sample fluid from a flow line and for pumping a preselected quantity of sample fluid with each pump driving stroke from the pump to a sample vessel, the sampling pump including a pump body defining a pump bore therein having a central axis, a piston slideably moveable within the pump bore and having a fluid inlet end and an opposing operator end, a fluid sample inlet port open to sample fluid in the flow line, a fluid sample outlet port for transmitting fluid from the pump bore to the sample vessel, and a line pressure port in fluid pressure sample fluid in the flow line, an inlet valve for selectively controlling sample fluid flow from the flow line through the fluid sample inlet port, an operator unit for periodically reciprocating the piston within the pump bore, and a controller for regulating the stroke of the piston within the pump bore, and thereby the quantity of fluid pumped with each pump driving stroke. It comprises a balanced check valve seat; a balanced check valve seal; a compression member; and a central plunger.

  16. Light extinction method for solubility measurement

    NASA Astrophysics Data System (ADS)

    Wang, Shui; Wang, Jingkang; Yin, Qiuxiang; Wang, Yongli

    2005-03-01

    A novel measurement method for chemical solubility determination is brought forward, in which the advantages of two kinds of traditional methods are united. The results show that the concentration of unsolved particles suspending in the solution can be determined by measuring I/I0 (ratio of the transmission intensity to the incident intensity) of the laser beam permeating through the solution according to Lamben-Beer law. The biggest relative deviation for the solubility data determined is less than 1.5% for the sparingly soluble substances and 0.3% for the opulently soluble substances. By comparison of the experimental solubility data with previous data, the light extinction method is demonstrated to be stable and reliable.

  17. Water-soluble conductive polymers

    DOEpatents

    Aldissi, Mahmoud

    1989-01-01

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  18. Water-soluble conductive polymers

    DOEpatents

    Aldissi, Mahmoud

    1990-01-01

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  19. Water-soluble conductive polymers

    DOEpatents

    Aldissi, M.

    1988-02-12

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  20. Environmentally safe fluid extractor

    DOEpatents

    Sungaila, Zenon F.

    1993-01-01

    An environmentally safe fluid extraction device for use in mobile laboratory and industrial settings comprising a pump, compressor, valving system, waste recovery tank, fluid tank, and a exhaust filtering system.

  1. Pleural fluid analysis

    MedlinePlus

    ... of fluid that has collected in the pleural space. This is the space between the lining of the outside of the ... the chest. When fluid collects in the pleural space, the condition is called pleural effusion .

  2. Pleural fluid smear

    MedlinePlus

    ... the fluid that has collected in the pleural space. This is the space between the lining of the outside of the ... the chest. When fluid collects in the pleural space, the condition is called pleural effusion .

  3. Peritoneal fluid analysis

    MedlinePlus

    ... at fluid that has built up in the space in the abdomen around the internal organs. This area is called the peritoneal space. ... sample of fluid is removed from the peritoneal space using a needle and syringe. Your health care ...

  4. Fluid sampling tool

    DOEpatents

    Johnston, Roger G.; Garcia, Anthony R. E.; Martinez, Ronald K.

    2001-09-25

    The invention includes a rotatable tool for collecting fluid through the wall of a container. The tool includes a fluid collection section with a cylindrical shank having an end portion for drilling a hole in the container wall when the tool is rotated, and a threaded portion for tapping the hole in the container wall. A passageway in the shank in communication with at least one radial inlet hole in the drilling end and an opening at the end of the shank is adapted to receive fluid from the container. The tool also includes a cylindrical chamber affixed to the end of the shank opposite to the drilling portion thereof for receiving and storing fluid passing through the passageway. The tool also includes a flexible, deformable gasket that provides a fluid-tight chamber to confine kerf generated during the drilling and tapping of the hole. The invention also includes a fluid extractor section for extracting fluid samples from the fluid collecting section.

  5. Electric fluid pump

    DOEpatents

    Van Dam, Jeremy Daniel; Turnquist, Norman Arnold; Raminosoa, Tsarafidy; Shah, Manoj Ramprasad; Shen, Xiaochun

    2015-09-29

    An electric machine is presented. The electric machine includes a hollow rotor; and a stator disposed within the hollow rotor, the stator defining a flow channel. The hollow rotor includes a first end portion defining a fluid inlet, a second end portion defining a fluid outlet; the fluid inlet, the fluid outlet, and the flow channel of the stator being configured to allow passage of a fluid from the fluid inlet to the fluid outlet via the flow channel; and wherein the hollow rotor is characterized by a largest cross-sectional area of hollow rotor, and wherein the flow channel is characterized by a smallest cross-sectional area of the flow channel, wherein the smallest cross-sectional area of the flow channel is at least about 25% of the largest cross-sectional area of the hollow rotor. An electric fluid pump and a power generation system are also presented.

  6. Pericardial fluid culture

    MedlinePlus

    ... medlineplus.gov/ency/article/003720.htm Pericardial fluid culture To use the sharing features on this page, please enable JavaScript. Pericardial fluid culture is a test performed on a sample of ...

  7. Environmentally safe fluid extractor

    DOEpatents

    Sungaila, Zenon F.

    1993-07-06

    An environmentally safe fluid extraction device for use in mobile laboratory and industrial settings comprising a pump, compressor, valving system, waste recovery tank, fluid tank, and a exhaust filtering system.

  8. Peritoneal fluid culture

    MedlinePlus

    Culture - peritoneal fluid ... sent to the laboratory for Gram stain and culture. The sample is checked to see if bacteria ... based on more than just the peritoneal fluid culture (which may be negative even if you have ...

  9. Fluid force transducer

    DOEpatents

    Jendrzejczyk, Joseph A.

    1982-01-01

    An electrical fluid force transducer for measuring the magnitude and direction of fluid forces caused by lateral fluid flow, includes a movable sleeve which is deflectable in response to the movement of fluid, and a rod fixed to the sleeve to translate forces applied to the sleeve to strain gauges attached to the rod, the strain gauges being connected in a bridge circuit arrangement enabling generation of a signal output indicative of the magnitude and direction of the force applied to the sleeve.

  10. Effects of drilling fluids on soils and plants: II. Complete drilling fluid mixtures

    SciTech Connect

    Miller, R.W.; Pesaran, P.

    1980-01-01

    Six typical drilling fluids (muds) and a drilling fluid base were mixed with six soils at ratios of 1:1 and 1:4 volumes of liquid mud/soil; these mixtures were tested for their effects on plant growth. Green beans (Phaseolus vulgaris) and sweet corn (Zea mays var. succharata (Sturtev.) Bailey) in pots in the greenhouse grew normally in a few mixtures, but in most instances plants had reduced growth when compared to those growing in soil alone (controls). It was concluded that high levels of soluble salts or the high exchangeable sodium percentages were the primary causes of reduced plant growth. The high salt content in some fluids was mostly from added potassium chloride, sodium hydroxide, and sodium dichromate. Dispersion of mud-treated soils caused by high exchangeable sodium percentages occurred in these samples because of the sodium hydroxide and sodium dichromate added to typical muds.

  11. Fluid Movement and Creativity

    ERIC Educational Resources Information Center

    Slepian, Michael L.; Ambady, Nalini

    2012-01-01

    Cognitive scientists describe creativity as fluid thought. Drawing from findings on gesture and embodied cognition, we hypothesized that the physical experience of fluidity, relative to nonfluidity, would lead to more fluid, creative thought. Across 3 experiments, fluid arm movement led to enhanced creativity in 3 domains: creative generation,…

  12. Toward a Molecular Understanding of Protein Solubility: Increased Negative Surface Charge Correlates with Increased Solubility

    PubMed Central

    Kramer, Ryan M.; Shende, Varad R.; Motl, Nicole; Pace, C. Nick; Scholtz, J. Martin

    2012-01-01

    Protein solubility is a problem for many protein chemists, including structural biologists and developers of protein pharmaceuticals. Knowledge about how intrinsic factors influence solubility is limited due to the difficulty of obtaining quantitative solubility measurements. Solubility measurements in buffer alone are difficult to reproduce, because gels or supersaturated solutions often form, making it impossible to determine solubility values for many proteins. Protein precipitants can be used to obtain comparative solubility measurements and, in some cases, estimations of solubility in buffer alone. Protein precipitants fall into three broad classes: salts, long-chain polymers, and organic solvents. Here, we compare the use of representatives from two classes of precipitants, ammonium sulfate and polyethylene glycol 8000, by measuring the solubility of seven proteins. We find that increased negative surface charge correlates strongly with increased protein solubility and may be due to strong binding of water by the acidic amino acids. We also find that the solubility results obtained for the two different precipitants agree closely with each other, suggesting that the two precipitants probe similar properties that are relevant to solubility in buffer alone. PMID:22768947

  13. An embedded boundary method for soluble surfactants with interface tracking for two-phase flows

    NASA Astrophysics Data System (ADS)

    Khatri, Shilpa; Tornberg, Anna-Karin

    2014-01-01

    Surfactants, surface reacting agents, lower the surface tension of the interface between fluids in multiphase flow. This capability of surfactants makes them ideal for many applications, including wetting, foaming, and dispersing. Due to their molecular composition, surfactants are adsorbed from the bulk fluid to the interface between the fluids, leading to different concentrations on the interface and in the fluid. In a previous paper [21], we introduced a new second order method using uniform grids to simulate insoluble surfactants in multiphase flow. This method used Strang splitting allowing for a fully second order treatment in time. Here, we use the same numerical methods to explicitly represent the singular interface, treat the interfacial surfactant concentration, and couple with the Navier-Stokes equations. Now, we introduce a second order method for the surfactants in the bulk that continues to allow the use of regular grids for the full problem. Difficulties arise since the boundary condition for the bulk concentration, which handles the flux of surfactant between the interface and bulk fluid, is applied at the interface which cuts arbitrarily through the regular grid. We extend the embedded boundary method, introduced in [22], to handle this challenge. Through our results, we present the effect of the solubility of the surfactants. We show results of drop dynamics due to resulting Marangoni stresses and of drop deformations in shear flow in the presence of soluble surfactants. There is a large nondimensional parameter space over which we try to understand the drop dynamics.

  14. Solubility prediction of drugs in mixed solvents using partial solubility parameters.

    PubMed

    Jouyban, Abolghasem; Shayanfar, Ali; Panahi-Azar, Vahid; Soleymani, Jafar; Yousefi, Behrooz H; Acree, William E; York, Peter

    2011-10-01

    Solubility of drugs in binary and ternary solvent mixtures composed of water and pharmaceutical cosolvents at different temperatures were predicted using the Jouyban-Acree model and a combination of partial solubility parameters as interaction descriptors in the solution. The generally trained version of the model produced the overall mean percentage deviation values for the back-calculated solubility of drugs in binary solvents of 34.3% and the predicted solubilities in ternary solvent mixtures of 38.0%. In addition, the applicability of the trained model for predicting the solvent composition providing the maximum solubility of a drug was investigated. The results of collected solubility data of drugs in various mixed solvents and the newly measured solubility data of five drugs in ethanol + propylene glycol + water mixtures at 25°C showed that the model provided acceptable predictions and could be used in the pharmaceutical industry.

  15. Soluble metals in residual oil fly ash alter innate and adaptive pulmonary immune responses to bacterial infection in rats

    SciTech Connect

    Roberts, Jenny R. . E-mail: jur6@cdc.gov; Young, Shih-Houng; Castranova, Vincent; Antonini, James M.

    2007-06-15

    The soluble metals of the pollutant, residual oil fly ash (ROFA), have been shown to alter pulmonary bacterial clearance in rats. The goal of this study was to determine the potential effects on both the innate and adaptive lung immune responses after bacterial infection in rats pre-exposed to the soluble metals in ROFA. Sprague-Dawley rats were intratracheally dosed (i.t.) at day 0 with ROFA (R-Total) (1.0 mg/100 g body weight), the soluble fraction of ROFA (R-Soluble), the soluble sample subject to a chelator (R-Chelex), or phosphate-buffered saline (Saline). On day 3, rats were administered an i.t. dose of 5 x 10{sup 4} Listeria monocytogenes. On days 6, 8, and 10, bacterial pulmonary clearance was monitored and bronchoalveolar lavage (BAL) was performed on days 3 (pre-infection), 6, 8, and 10. A concentrated first fraction of lavage fluid was retained for analysis of lactate dehydrogenase and albumin to assess lung injury. BAL cell number, phenotype, and production of reactive oxygen (ROS) and nitrogen species (RNS) were assessed, and a variety of cytokines were measured in the BAL fluid. Rats pre-treated with R-Soluble showed elevated lung injury/cytotoxicity and increased cellular influx into the lungs. R-Soluble-treatment also altered ROS, RNS, and cytokine levels, and caused a degree of macrophage and T cell inhibition. These effects of R-Soluble result in increased pulmonary bacterial burden after infection. The results suggest that soluble metals in ROFA increase lung injury and inflammation, and alter both innate and adaptive pulmonary immune responses.

  16. Drug carrier systems for solubility enhancement of BCS class II drugs: a critical review.

    PubMed

    Kumar, Sumit; Bhargava, Deepak; Thakkar, Arti; Arora, Saahil

    2013-01-01

    Poor aqueous solubility impedes a drug's bioavailability and challenges its pharmaceutical development. Pharmaceutical development of drugs with poor water solubility requires the establishment of a suitable formulation layout among various techniques. Various approaches have been investigated extensively to improve the aqueous solubility and poor dissolution rate of BCS class II and IV drugs. In this literature review, novel formulation options, particularly for class II drugs designed for applications such as micronization, self-emulsification, cyclodextrin complexation, co-crystallisation, super critical fluid technology, solubilisation by change in pH, salt formation, co-solvents, melt granulation, and solid dispersion, liposomal/niosomal formulations, are discussed in detail to introduce biopharmaceutical challenges and recent approaches to facilitate more efficient drug formulation and development.

  17. Salt formation to improve drug solubility.

    PubMed

    Serajuddin, Abu T M

    2007-07-30

    Salt formation is the most common and effective method of increasing solubility and dissolution rates of acidic and basic drugs. In this article, physicochemical principles of salt solubility are presented, with special reference to the influence of pH-solubility profiles of acidic and basic drugs on salt formation and dissolution. Non-ideality of salt solubility due to self-association in solution is also discussed. Whether certain acidic or basic drugs would form salts and, if salts are formed, how easily they would dissociate back into their free acid or base forms depend on interrelationships of several factors, such as S0 (intrinsic solubility), pH, pKa, Ksp (solubility product) and pHmax (pH of maximum solubility). The interrelationships of these factors are elaborated and their influence on salt screening and the selection of optimal salt forms for development are discussed. Factors influencing salt dissolution under various pH conditions, and especially in reactive media and in presence of excess common ions, are discussed, with practical reference to the development of solid dosage forms.

  18. Bibliography on contaminants and solubility of organic compounds in oxygen

    NASA Technical Reports Server (NTRS)

    Ordin, P. M. (Compiler)

    1975-01-01

    A compilation of a number of document citations is presented which contains information on contaminants in oxygen. Topics covered include contaminants and solubility of organic compounds in oxygen, reaction characteristics of organic compounds with oxygen, and sampling and detection limits of impurities. Each citation in the data bank contains many items of information about the document. Some of the items are title, author, abstract, corporate source, description of figures pertinent to hazards or safety, key references, and descriptors (keywords) by which the document can be retrieved. Each citation includes an evaluation of the technical contents as to being good/excellent, acceptable, or poor. The descriptors used to define the contents of the documents and subsequently used in the computerized search operations were developed for the cryogenic fluid safety by experts in the cryogenics field.

  19. Polymer particulates control fluid loss during well completions

    SciTech Connect

    Ali, S.A.; Nguyen, P.D.; Weaver, J.D.

    1997-05-12

    In its Gulf of Mexico operations, Chevron U.S.A. Production Co. has effectively controlled completion fluid loss to the formation by including nondamaging, soluble particulates (NSP) in the fluid. In seven Chevron wells recently completed in the Gulf of Mexico, fluid loss dropped to very low levels or zero with NSP included in the completion fluid. Conventional particulate-based, fluid-loss control methods have shown varying degrees of fluid-loss control. But these methods have the potential to cause near well bore damage and long cleanup periods. In contrast, the NSP fluid-loss additive can be cleaned up readily and causes very little decrease in formation permeability. NSP is stable enough to store and is provided as a slurry concentrate that can be dispersed easily in completion fluid. It can be pumped and mixed in the field with conventional equipment. NSP forms a barrier or filter cake that covers the surface of the formation or perforation where fluid loss is occurring.

  20. Goal directed fluid therapy.

    PubMed

    Marik, Paul E; Desai, Himanshu

    2012-01-01

    The cornerstone of treating patients with shock remains as it has for decades, intravenous fluids. Surprisingly, dosing intravenous fluid during resuscitation of shock remains largely empirical. Recent data suggests that early aggressive resuscitation of critically ill patients may limit and/or reverse tissue hypoxia, progression to organ failure and improve outcome. However, overzealous fluid resuscitation has been associated with increased complications, increased length of intensive care unit (ICU) and hospital stay and increased mortality. This review focuses on methods to assess fluid responsiveness and the application of these methods for goal directed fluid therapy in critically ill and peri-operative patients.

  1. Soluble for crosslinked graft copolymers of lignin based on hydroxyethylmethacrylate and acrylamide

    SciTech Connect

    Meister, J.J.

    1992-06-16

    This patent describes a method for recovering oil from subterranean wells. It comprises dispersing a soluble graft-copolymer of lignin-(2-propenamide)-(2-methyl-3-oxo-4-oxyhex-1-ene-6-ol) in injection water to form a mixture; injecting the mixture into the subterranean formation and allowing it form a foam; and moving the injection fluid through the formation as a hydraulic ram, thereby pushing the resident oil to a production well.

  2. Placement in an acidic environment increase the solubility of white mineral trioxide aggregate

    PubMed Central

    Yavari, Hamid Reza; Borna, Zahra; Rahimi, Saeed; Shahi, Shahriar; Valizadeh, Hadi; Ghojazadeh, Morteza

    2013-01-01

    Aims: The aim of the present study was to evaluate solubility of white mineral trioxide aggregate (WMTA) in an acidic environment. Materials and Methods: Twenty-four metal rings were prepared, filled with WMTA and randomly divided into two groups. The samples in groups 1 and 2 were set in synthetic tissue fluid with pH values of 7.4 and 4.4, respectively and then were transferred to beakers containing synthetic tissue fluid with pH values of 7.7 and 4.4. Solubility of WMTA samples were calculated at the 9 experimental intervals. Data was analyzed with two-factor ANOVA and Bonferroni test (P < 0.03). Results: The total solubility of WMTA in groups 1 and 2 were −9.1796 ± 1.9158% and −1.1192 ± 2.6236%, (P = 0.028) with weight changes of 9.1574 ± 2.1432% and 7.3276 ± 1.5823%, respectively (P = 0.002). Statistical analysis revealed significant differences between the two groups. Conclusions: It was concluded that solubility of WMTA increases in acidic environments and additional therapeutic precautions should be taken to decrease inflammation in endodontic treatment. PMID:23833462

  3. Oxygen solubility and permeability of carbohydrates.

    PubMed

    Whitcombe, Michael J; Parker, Roger; Ring, Stephen G

    2005-06-13

    The saturated oxygen concentration in a series of aqueous solutions of sorbitol (up to 35% w/w) and maltitol (up to 50% w/w) was measured using colorimetric reagent vials based on Rhodazine D. The results indicate that the solubility of oxygen in low-water carbohydrates is considerably lower than its solubility in pure water. It was concluded that the low-oxygen solubility is a major factor contributing to the barrier properties of low-water content carbohydrates used in the encapsulation of flavours, lipids, peptides and other oxidisable species.

  4. Spinning fluids reactor

    DOEpatents

    Miller, Jan D; Hupka, Jan; Aranowski, Robert

    2012-11-20

    A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.

  5. Perioperative Fluid Restriction

    PubMed Central

    Bleier, Joshua I.S.; Aarons, Cary B.

    2013-01-01

    Perioperative fluid management of the colorectal surgical patient has evolved significantly over the last five decades. Older notions espousing aggressive hydration have been shown to be associated with increased complications. Newer data regarding fluid restriction has shown an association with improved outcomes. Management of perioperative fluid administration can be considered in three primary phases: In the preoperative phase, data suggests that avoidance of preoperative bowel preparation and avoidance of undue preoperative dehydration can improve outcomes. Although the type of intraoperative fluid given does not have a significant effect on outcome, data do suggest that a restrictive fluid regimen results in improved outcomes. Finally, in the postoperative phase of fluid management, a fluid-restrictive regimen, coupled with early enteral feeding also seems to result in improved outcomes. PMID:24436675

  6. Fluid cooled electrical assembly

    DOEpatents

    Rinehart, Lawrence E.; Romero, Guillermo L.

    2007-02-06

    A heat producing, fluid cooled assembly that includes a housing made of liquid-impermeable material, which defines a fluid inlet and a fluid outlet and an opening. Also included is an electrical package having a set of semiconductor electrical devices supported on a substrate and the second major surface is a heat sink adapted to express heat generated from the electrical apparatus and wherein the second major surface defines a rim that is fit to the opening. Further, the housing is constructed so that as fluid travels from the fluid inlet to the fluid outlet it is constrained to flow past the opening thereby placing the fluid in contact with the heat sink.

  7. A novel approach on fluid dispensing for a DNA/RNA extraction chip package

    NASA Astrophysics Data System (ADS)

    Xie, Ling; Premachandran, C. S.; Chew, Michelle; Yao, Qiang; Xu, Diao; Pinjala, D.

    2008-02-01

    Micro fluidic package with integrated reservoirs has been developed for DNA /RNA extraction application. A membrane based pump which consists of a reservoir to store reagents and a pin valve to control the fluid is developed to dispense the reagents into the chip. A programmable external actuator is fabricated to dispense the fluid from the membrane pump into the DNA chip. An elastic and high elongation thin rubber membrane is used to seal the membrane pump and at the same time prevent actuator from mixing with different reagents in the micro fluidic package. Break displacement during actuation of membrane pump sealing material is studied with different ratios of PDMS and other types of rubber materials. The fluid flow from the reservoir to the chip is controlled by a pin valve which is activated during the external actuation. A CFD simulation is performed to study the pumping action dusting the external actuation and is validated with experimental results.

  8. Solubility and diffusion of oxygen in phospholipid membranes.

    PubMed

    Möller, Matías N; Li, Qian; Chinnaraj, Mathivanan; Cheung, Herbert C; Lancaster, Jack R; Denicola, Ana

    2016-11-01

    The transport of oxygen and other nonelectrolytes across lipid membranes is known to depend on both diffusion and solubility in the bilayer, and to be affected by changes in the physical state and by the lipid composition, especially the content of cholesterol and unsaturated fatty acids. However, it is not known how these factors affect diffusion and solubility separately. Herein we measured the partition coefficient of oxygen in liposome membranes of dilauroyl-, dimiristoyl- and dipalmitoylphosphatidylcholine in buffer at different temperatures using the equilibrium-shift method with electrochemical detection. The apparent diffusion coefficient was measured following the fluorescence quenching of 1-pyrenedodecanoate inserted in the liposome bilayers under the same conditions. The partition coefficient varied with the temperature and the physical state of the membrane, from below 1 in the gel state to above 2.8 in the liquid-crystalline state in DMPC and DPPC membranes. The partition coefficient was directly proportional to the partial molar volume and was then associated to the increase in free-volume in the membrane as a function of temperature. The apparent diffusion coefficients were corrected by the partition coefficients and found to be nearly the same, with a null dependence on viscosity and physical state of the membrane, probably because the pyrene is disturbing the surrounding lipids and thus becoming insensitive to changes in membrane viscosity. Combining our results with those of others, it is apparent that both solubility and diffusion increase when increasing the temperature or when comparing a membrane in the gel to one in the fluid state.

  9. Simulations of solvation free energies and solubilities in supercritical solvents

    NASA Astrophysics Data System (ADS)

    Su, Zemin; Maroncelli, Mark

    2006-04-01

    Computer simulations are used to study solvation free energies and solubilities in supercritical solvents. Solvation free energies are calculated using the particle insertion method. The equilibrium solvent configurations required for these calculations are based on molecular dynamics simulations employing model solvent potentials previously tuned to reproduce liquid-vapor coexistence properties of the fluids Xe, C2H6, CO2, and CHF3. Solutes are represented by all-atom potentials based on ab initio calculations and the OPLS-AA parameter set. Without any tuning of the intermolecular potentials, such calculations are found to reproduce the solvation free energies of a variety of typical solid solutes with an average accuracy of ±2kJ /mol. Further calculations on simple model solutes are also used to explore general aspects of solvation free energies in supercritical solvents. Comparisons of solutes in Lennard-Jones and hard-sphere representations of Xe show that solvation free energies and thus solubilities are not significantly influenced by solvent density fluctuations near the critical point. The solvation enthalpy and entropy do couple to these fluctuations and diverge similarly to solute partial molar volumes. Solvation free energies are also found to be little affected by the local density augmentation characteristic of the compressible regime. In contrast to solute-solvent interaction energies, which often provide a direct measure of local solvent densities, solvation free energies are remarkably insensitive to the presence of local density augmentation.

  10. Hydrocarbon soluble polymer complexes useful as viscosifiers in fracturing operations

    SciTech Connect

    Lundberg, R.D.; Peiffer, D.G.; Sedillo, L.P.; Newlove, J.C.

    1986-04-01

    This patent describes a process for fracturing a subterranean formation surrounding a gas or oil well. This process consists of injecting into the subterranean formation under fracturing pressure a fluid comprising about 0.01 to about 25 weight percent of a polymer complex dissolved in a solvent system of a nonpolar organic liquid hydrocarbon having a solubility parameter of less then 9.5. The polymer complex consists of the interaction product of a sulfonated polymer and an amine containing polymer which is hydrocarbon soluble, wherein the sulfonated polymer is selected from the group consisting of sulfonated polystyrene, sulfonated EPDM terpolymer, sulfonated polyisoprene, sulfonated ethylene, sulfonated propylene, sulfonated ethylene/propylene copolymers, sulfonated styrene/acrylonitrile copolymers and sulfonated styrene/methyl methacrylate copolymers. The sulfonate content of the sulfonated polymer is about 4 meq. per 100 gram of polymer to about 200 meq. per 100 gram of polymer and the basic nitrogen content of the amine containing polymer is about 4 meq. per 100 gram of polymer to about 500 meq. per 100 gram of polymer. The amine containing polymer is a copolymer of vinyl pyridine with other vinyl monomers and the number average molecular weight of the amine containg polymer is about 10,000 to about 10,000,000, and the number average molecular weight of the sulfonated polymer is from 1,000 to 10,000,000. The mole ratio of the sulfonated polymer to the amine-containing polymer is about 1:15 to 15:1.

  11. Effect of Cyclodextrin Types and Co-Solvent on Solubility of a Poorly Water Soluble Drug

    PubMed Central

    Charumanee, Suporn; Okonogi, Siriporn; Sirithunyalug, Jakkapan; Wolschann, Peter; Viernstein, Helmut

    2016-01-01

    The aim of the study was to investigate the solubility of piroxicam (Prx) depending on the inclusion complexation with various cyclodextrins (CDs) and on ethanol as a co-solvent. The phase-solubility method was applied to determine drug solubility in binary and ternary systems. The results showed that in systems consisting of the drug dissolved in ethanol–water mixtures, the drug solubility increased exponentially with a rising concentration of ethanol. The phase solubility measurements of the drug in aqueous solutions of CDs, β-CD and γ-CD exhibited diagrams of AL-type, whereas 2,6-dimethyl-β-CD revealed AP-type. The destabilizing effect of ethanol as a co-solvent was observed for all complexes regardless of the CD type, as a consequence of it the lowering of the complex formation constants. In systems with a higher concentration of ethanol, the drug solubility was increased in opposition to the decreasing complex formation constants. According to this study, the type of CDs played a more important role on the solubility of Prx, and the use of ethanol as a co-solvent exhibited no synergistic effect on the improvement of Prx solubility. The Prx solubility was increased again due to the better solubility in ethanol. PMID:27763573

  12. Determining time-weighted average concentrations of nitrate and ammonium in freshwaters using DGT with ion exchange membrane-based binding layers.

    PubMed

    Huang, Jianyin; Bennett, William W; Welsh, David T; Teasdale, Peter R

    2016-12-08

    Commercially-available AMI-7001 anion exchange and CMI-7000 cation exchange membranes were utilised as binding layers for DGT measurements of NO3-N and NH4-N in freshwaters. These ion exchange membranes are easier to prepare and handle than DGT binding layers consisting of hydrogels cast with ion exchange resins. The membranes showed good uptake and elution efficiencies for both NO3-N and NH4-N. The membrane-based DGTs are suitable for pH 3.5-8.5 and ionic strength ranges (0.0001-0.014 and 0.0003-0.012 mol L(-1) as NaCl for the AMI-7001 and CMI-7000 membrane, respectively) typical of most natural freshwaters. The binding membranes had high intrinsic binding capacities for NO3-N and NH4-N of 911 ± 88 μg and 3512 ± 51 μg, respectively. Interferences from the major competing ions for membrane-based DGTs are similar to DGTs employing resin-based binding layers but with slightly different selectivity. This different selectivity means that the two DGT types can be used in different types of freshwaters. The laboratory and field experiments demonstrated that AMI-DGT and CMI-DGT can be an alternative to A520E-DGT and PrCH-DGT for measuring NO3-N and NH4-N, respectively, as (i) membrane-based DGT have a consistent composition, (ii) avoid the use of toxic chemicals, (iii) provided highly representative results (CDGT : CSOLN between 0.81 and 1.3), and (iv) agreed with resin-based DGTs to within 85-120%.

  13. Drilling fluids with scavengers help control H[sub 2]S

    SciTech Connect

    Scott, P. )

    1994-05-23

    Maintaining a high pH and using chemical sulfide scavengers in oil-based and water-based drilling muds can neutralize hydrogen sulfide (H[sub 2]S). Safe, successful drilling of H[sub 2]S-bearing formations requires good drilling practices, extra attention to casing design, and proper drilling fluid formulation. The drilling fluid must be capable of controlling formation pressures, protecting workers, inhibiting corrosion, limiting drilling fluid contamination, maintaining well bore stability, and removing sulfide contamination rapidly. High-alkalinity drilling fluids with excess lime are recommended to provide buffering capacity for pH neutralization. Following the detection of soluble sulfides, the fluid should be immediately treated with the applicable scavenger. Sulfide scavengers must react with soluble sulfides to form an insoluble metal sulfide precipitate. Effective scavengers must have rapid and complete reactions with H[sup 2]S, HS[sup [minus

  14. DEVELOPMENT OF SOLUBILITY PRODUCT VISUALIZATION TOOLS

    SciTech Connect

    T.F. Turner; A.T. Pauli; J.F. Schabron

    2004-05-01

    Western Research Institute (WRI) has developed software for the visualization of data acquired from solubility tests. The work was performed in conjunction with AB Nynas Petroleum, Nynashamn, Sweden who participated as the corporate cosponsor for this Jointly Sponsored Research (JSR) task. Efforts in this project were split between software development and solubility test development. The Microsoft Windows-compatible software developed inputs up to three solubility data sets, calculates the parameters for six solid body types to fit the data, and interactively displays the results in three dimensions. Several infrared spectroscopy techniques have been examined for potential use in determining bitumen solubility in various solvents. Reflectance, time-averaged absorbance, and transmittance techniques were applied to bitumen samples in single and binary solvent systems. None of the techniques were found to have wide applicability.

  15. Predicting the octanol solubility of organic compounds.

    PubMed

    Admire, Brittany; Yalkowsky, Samuel H

    2013-07-01

    The molar octanol solubility of an organic nonelectrolytes can be reasonably predicted solely from its melting point provided that its liquid (or a hypothetical super-cooled liquid) form is miscible with octanol. The aim of this work is to develop criteria to determine if the real or hypothetical liquid form of a given compound will be miscible with octanol based on its molar volume and solubility parameter. Fortunately, most organic compounds (including most drugs) conform to the criteria for complete liquid miscibility, and therefore have solubilities that are proportional to their melting points. The results show that more than 95% of the octanol solubilities studied are predicted with an error of less than 1 logarithmic unit.

  16. Acid soluble, pepsin resistant platelet aggregating material

    SciTech Connect

    Schneider, M.D.

    1982-08-31

    Disclosed is an acid soluble, pepsin resistant, platelet aggregating material isolated from equine arterial tissue by extraction with dilute aqueous acid. The method of isolation and use to control bleeding are described. 4 figs.

  17. An Introduction to the Understanding of Solubility.

    ERIC Educational Resources Information Center

    Letcher, Trevor M.; Battino, Rubin

    2001-01-01

    Explores different solubility processes and related issues, including the second law of thermodynamics and ideal mixtures, real liquids, intermolecular forces, and solids in liquids or gases in liquids. (Contains 22 references.) (ASK)

  18. Solubility of carbohydrates in heavy water.

    PubMed

    Cardoso, Marcus V C; Carvalho, Larissa V C; Sabadini, Edvaldo

    2012-05-15

    The solubility of several mono-(glucose and xylose), di-(sucrose and maltose), tri-(raffinose) and cyclic (α-cyclodextrin) saccharides in H(2)O and in D(2)O were measured over a range of temperatures. The solution enthalpies for the different carbohydrates in the two solvents were determined using the vant' Hoff equation and the values in D(2)O are presented here for the first time. Our findings indicate that the replacement of H(2)O by D(2)O remarkably decreases the solubilities of the less soluble carbohydrates, such as maltose, raffinose and α-cyclodextrin. On the other hand, the more soluble saccharides, glucose, xylose, and sucrose, are practically insensitive to the H/D replacement in water.

  19. Organogel formation rationalized by Hansen solubility parameters.

    PubMed

    Raynal, Matthieu; Bouteiller, Laurent

    2011-08-07

    Some organic compounds gelate particular solvents by forming a network of anisotropic fibres. We show that Hansen solubility parameters can be used to predict the range of solvents that are likely to be gelled by any given gelator.

  20. Computational identification of a metal organic framework for high selectivity membrane-based CO2/CH4 separations: Cu(hfipbb)(H2hfipbb)0.5.

    PubMed

    Watanabe, Taku; Keskin, Seda; Nair, Sankar; Sholl, David S

    2009-12-28

    The identification of membrane materials with high selectivity for CO(2)/CH(4) mixtures could revolutionize this industrially important separation. We predict using computational methods that a metal organic framework (MOF), Cu(hfipbb)(H(2)hfipbb)(0.5), has unprecedented selectivity for membrane-based separation of CO(2)/CH(4) mixtures. Our calculations combine molecular dynamics, transition state theory, and plane wave DFT calculations to assess the importance of framework flexibility in the MOF during molecular diffusion. This combination of methods should also make it possible to identify other MOFs with attractive properties for kinetic separations.

  1. Fluid sampling pump

    SciTech Connect

    Allen, P.V.; Nimberger, S.M.; Ward, R.L.

    1992-03-03

    This patent describes a pump for pumping a preselected quantity of fluid with each pump driving stroke from a fluid inlet port to a fluid outlet port, an inlet valve for selectively controlling fluid flow through the fluid inlet port, a pump body defining a pump bore therein, a piston slidably movable within the pump bore and having a fluid inlet end and an opposing operator end, an operator unit for reciprocating the piston within the pump bore, and a manifold interconnect with the pump body. It comprises a flow path therein extending from a manifold inlet port to a manifold outlet port, flow path being in communication with the fluid outlet port in the pump body, a purge passageway extending from the flow path to the outlet passageway, a purge valve for regulating fluid flow through the purge passageway, and a filter positioned within the manifold and extending across a portion of the flow path, the filter defining a filtered zone within the flow path adjoining the inlet port in the pump body, and an unfiltered zone within the flow path extending from the manifold inlet to the manifold outlet, such that filtered fluid enters the pump bore while unfiltered fluid bypasses the filter and passes out the manifold outlet port.

  2. Correlation of Helium Solubility in Liquid Nitrogen

    NASA Technical Reports Server (NTRS)

    VanDresar, Neil T.; Zimmerli, Gregory A.

    2012-01-01

    A correlation has been developed for the equilibrium mole fraction of soluble gaseous helium in liquid nitrogen as a function of temperature and pressure. Experimental solubility data was compiled and provided by National Institute of Standards and Technology (NIST). Data from six sources was used to develop a correlation within the range of 0.5 to 9.9 MPa and 72.0 to 119.6 K. The relative standard deviation of the correlation is 6.9 percent.

  3. GADOLINIUM SOLUBILITY AND VOLATILITY DURING DWPF PROCESSING

    SciTech Connect

    Reboul, S

    2008-01-30

    Understanding of gadolinium behavior, as it relates to potential neutron poisoning applications at the DWPF, has increased over the past several years as process specific data have been generated. Of primary importance are phenomena related to gadolinium solubility and volatility, which introduce the potential for gadolinium to be separated from fissile materials during Chemical Process Cell (CPC) and Melter operations. Existing data indicate that gadolinium solubilities under moderately low pH conditions can vary over several orders of magnitude, depending on the quantities of other constituents that are present. With respect to sludge batching processes, the gadolinium solubility appears to be highly affected by iron. In cases where the mass ratio of Fe:Gd is 300 or more, the gadolinium solubility has been observed to be low, one milligram per liter or less. In contrast, when the ratio of Fe:Gd is 20 or less, the gadolinium solubility has been found to be relatively high, several thousands of milligrams per liter. For gadolinium to serve as an effective neutron poison in CPC operations, the solubility needs to be limited to approximately 100 mg/L. Unfortunately, the Fe:Gd ratio that corresponds to this solubility limit has not been identified. Existing data suggest gadolinium and plutonium are not volatile during melter operations. However, the data are subject to inherent uncertainties preventing definitive conclusions on this matter. In order to determine if gadolinium offers a practical means of poisoning waste in DWPF operations, generation of additional data is recommended. This includes: Gd solubility testing under conditions where the Fe:Gd ratio varies from 50 to 150; and Gd and Pu volatility studies tailored to quantifying high temperature partitioning. Additional tests focusing on crystal aging of Gd/Pu precipitates should be pursued if receipt of gadolinium-poisoned waste into the Tank Farm becomes routine.

  4. Correlation of Catalytic Rates With Solubility Parameters

    NASA Technical Reports Server (NTRS)

    Lawson, Daniel D.; England, Christopher

    1987-01-01

    Catalyst maximizes activity when its solubility parameter equals that of reactive species. Catalytic activities of some binary metal alloys at maximum when alloy compositions correspond to Hildebrand solubility parameters equal to those of reactive atomic species on catalyst. If this suggestive correlation proves to be general, applied to formulation of other mixed-metal catalysts. Also used to identify reactive species in certain catalytic reactions.

  5. Sibutramine characterization and solubility, a theoretical study

    NASA Astrophysics Data System (ADS)

    Aceves-Hernández, Juan M.; Nicolás Vázquez, Inés; Hinojosa-Torres, Jaime; Penieres Carrillo, Guillermo; Arroyo Razo, Gabriel; Miranda Ruvalcaba, René

    2013-04-01

    Solubility data from sibutramine (SBA) in a family of alcohols were obtained at different temperatures. Sibutramine was characterized by using thermal analysis and X-ray diffraction technique. Solubility data were obtained by the saturation method. The van't Hoff equation was used to obtain the theoretical solubility values and the ideal solvent activity coefficient. No polymorphic phenomena were found from the X-ray diffraction analysis, even though this compound is a racemic mixture of (+) and (-) enantiomers. Theoretical calculations showed that the polarisable continuum model was able to reproduce the solubility and stability of sibutramine molecule in gas phase, water and a family of alcohols at B3LYP/6-311++G (d,p) level of theory. Dielectric constant, dipolar moment and solubility in water values as physical parameters were used in those theoretical calculations for explaining that behavior. Experimental and theoretical results were compared and good agreement was obtained. Sibutramine solubility increased from methanol to 1-octanol in theoretical and experimental results.

  6. Chromatographic determination of solubilities in superheated water.

    PubMed

    Jones, Neil; Clifford, Anthony A; Bartle, Keith D; Myers, Peter

    2010-10-01

    Superheated water (SHW) is an effective solvent for the extraction of a variety of environmental pollutants, but knowledge of the solubilities in water at elevated temperatures necessary to maximise the efficiency of the process is often lacking. Ambient temperature aqueous solubilities have been measured by reverse-phase HPLC from correlations with retention factors, k, but for poorly soluble organics the eluent must contain a proportion of organic modifier followed by extrapolation to pure water. The use of SHW as mobile phase allows direct determination of aqueous solubility from measurement of k on a modified HPLC system in which the eluent is cooled before detection to improve baseline stability. Alumina-bonded octadecylsilane columns were found to be more stable in SHW chromatography than their silica-bonded counterparts. To validate the procedure, measurements of k were made between 100 and 200°C for toluene and correlated with literature solubilities; the solubilities at 170°C of a number of related aromatics were then determined from their k-values.

  7. How Soluble GARP Enhances TGFβ Activation

    PubMed Central

    Fridrich, Sven; Hahn, Susanne A.; Linzmaier, Marion; Felten, Matthias; Zwarg, Jenny; Lennerz, Volker; Tuettenberg, Andrea; Stöcker, Walter

    2016-01-01

    GARP (glycoprotein A repetitions predominant) is a cell surface receptor on regulatory T-lymphocytes, platelets, hepatic stellate cells and certain cancer cells. Its described function is the binding and accommodation of latent TGFβ (transforming growth factor), before the activation and release of the mature cytokine. For regulatory T cells it was shown that a knockdown of GARP or a treatment with blocking antibodies dramatically decreases their immune suppressive capacity. This confirms a fundamental role of GARP in the basic function of regulatory T cells. Prerequisites postulated for physiological GARP function include membrane anchorage of GARP, disulfide bridges between the propeptide of TGFβ and GARP and connection of this propeptide to αvβ6 or αvβ8 integrins of target cells during mechanical TGFβ release. Other studies indicate the existence of soluble GARP complexes and a functionality of soluble GARP alone. In order to clarify the underlying molecular mechanism, we expressed and purified recombinant TGFβ and a soluble variant of GARP. Surprisingly, soluble GARP and TGFβ formed stable non-covalent complexes in addition to disulfide-coupled complexes, depending on the redox conditions of the microenvironment. We also show that soluble GARP alone and the two variants of complexes mediate different levels of TGFβ activity. TGFβ activation is enhanced by the non-covalent GARP-TGFβ complex already at low (nanomolar) concentrations, at which GARP alone does not show any effect. This supports the idea of soluble GARP acting as immune modulator in vivo. PMID:27054568

  8. Ammonia Solubility in High Concentration Salt Solutions

    SciTech Connect

    HEDENGREN, D.C.

    2000-02-01

    Solubility data for ammonia in water and various dilute solutions are abundant in the literature. However, there is a noticeable lack of ammonia solubility data for high salt, basic solutions of various mixtures of salts including those found in many of the Hanford Washington underground waste tanks. As a result, models based on solubility data for dilute salt solutions have been used to extrapolate to high salt solutions. These significant extrapolations need to be checked against actual laboratory data. Some indirect vapor measurements have been made. A more direct approach is to determine the ratio of solubility of ammonia in water to its solubility in high salt solutions. In various experiments, pairs of solutions, one of which is water and the other a high salt solution, are allowed to come to equilibrium with a common ammonia vapor pressure. The ratio of concentrations of ammonia in the two solutions is equal to the ratio of the respective ammonia solubilities (Henry's Law constants) at a given temperature. This information can then be used to refine the models that predict vapor space compositions of ammonia. Ammonia at Hanford is of concern because of its toxicity in the environment and its contribution to the flammability of vapor space gas mixtures in waste tanks.

  9. A Comparative Proteomic Analysis of the Soluble Immune Factor Environment of Rectal and Oral Mucosa

    PubMed Central

    Romas, Laura M.; Hasselrot, Klara; Aboud, Lindsay G.; Birse, Kenzie D.; Ball, T. Blake; Broliden, Kristina; Burgener, Adam D.

    2014-01-01

    Objective Sexual transmission of HIV occurs across a mucosal surface, which contains many soluble immune factors important for HIV immunity. Although the composition of mucosal fluids in the vaginal and oral compartments has been studied extensively, the knowledge of the expression of these factors in the rectal mucosa has been understudied and is very limited. This has particular relevance given that the highest rates of HIV acquisition occur via the rectal tract. To further our understanding of rectal mucosa, this study uses a proteomics approach to characterize immune factor components of rectal fluid, using saliva as a comparison, and evaluates its antiviral activity against HIV. Methods Paired salivary fluid (n = 10) and rectal lavage fluid (n = 10) samples were collected from healthy, HIV seronegative individuals. Samples were analyzed by label-free tandem mass spectrometry to comprehensively identify and quantify mucosal immune protein abundance differences between saliva and rectal fluids. The HIV inhibitory capacity of these fluids was further assessed using a TZM-bl reporter cell line. Results Of the 315 proteins identified in rectal lavage fluid, 72 had known immune functions, many of which have described anti-HIV activity, including cathelicidin, serpins, cystatins and antileukoproteinase. The majority of immune factors were similarly expressed between fluids, with only 21 differentially abundant (p<0.05, multiple comparison corrected). Notably, rectal mucosa had a high abundance of mucosal immunoglobulins and antiproteases relative to saliva, Rectal lavage limited HIV infection by 40–50% in vitro (p<0.05), which is lower than the potent anti-HIV effect of oral mucosal fluid (70–80% inhibition, p<0.005). Conclusions This study reveals that rectal mucosa contains many innate immune factors important for host immunity to HIV and can limit viral replication in vitro. This indicates an important role for this fluid as the first line of defense

  10. Room-temperature ionic liquids: temperature dependence of gas solubility selectivity

    SciTech Connect

    Alexia Finotello; Jason E. Bara; Dean Camper; Richard D. Noble

    2008-05-15

    This study focuses on bulk fluid solubility of carbon dioxide (CO{sub 2}), methane (CH{sub 4}), hydrogen (H{sub 2}), and nitrogen (N{sub 2}) gases in the imidazolium-based RTILs: 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ((emim)(Tf{sub 2}N)),1-ethyl-3-methylimidazolium tetrafluoroborate ((emim)(BF{sub 4})),1-n-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide((hmim)(Tf{sub 2}N)), and 1,3-dimethylimidazolium methyl sulfate ((mmim)(MeSO{sub 4})) as a function of temperature (25, 40, 55, and 70{sup o}C) at near-atmospheric pressures. The experimental behaviors are explained in terms of thermodynamic relationships that account for the negligible vapor pressure of the RTIL as well as the low solubilities of the gases. Results show that, as temperature increases, the solubility of CO{sub 2} decreases in all RTILs, the solubility of CH{sub 4} remains constant in (emim)(Tf{sub 2}N) and (hmim)(Tf{sub 2}N) but increases in(mmim)(MeSO{sub 4}) and (emim)(BF{sub 4}), and the solubility of N{sub 2} and H{sub 2} increases. Also, the ideal solubility selectivity (ratio of pure-component solubilities) increases as temperature decreases for CO{sub 2}/N{sub 2}, CO{sub 2}/CH{sub 4}, and CO{sub 2}/H{sub 2} systems. Experimental values for the enthalpy and entropy of solvation are reported.

  11. Microwave fluid flow meter

    DOEpatents

    Billeter, Thomas R.; Philipp, Lee D.; Schemmel, Richard R.

    1976-01-01

    A microwave fluid flow meter is described utilizing two spaced microwave sensors positioned along a fluid flow path. Each sensor includes a microwave cavity having a frequency of resonance dependent upon the static pressure of the fluid at the sensor locations. The resonant response of each cavity with respect to a variation in pressure of the monitored fluid is represented by a corresponding electrical output which can be calibrated into a direct pressure reading. The pressure drop between sensor locations is then correlated as a measure of fluid velocity. In the preferred embodiment the individual sensor cavities are strategically positioned outside the path of fluid flow and are designed to resonate in two distinct frequency modes yielding a measure of temperature as well as pressure. The temperature response can then be used in correcting for pressure responses of the microwave cavity encountered due to temperature fluctuations.

  12. Fiber optic fluid detector

    DOEpatents

    Angel, S. Michael

    1989-01-01

    Particular gases or liquids are detected with a fiber optic element (11, 11a to 11j) having a cladding or coating of a material (23, 23a to 23j) which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector (24, 24a to 24j) may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses.

  13. Fiber optic fluid detector

    DOEpatents

    Angel, S.M.

    1987-02-27

    Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.

  14. Applications of supercritical fluids.

    PubMed

    Brunner, Gerd

    2010-01-01

    This review discusses supercritical fluids in industrial and near-to-industry applications. Supercritical fluids are flexible tools for processing materials. Supercritical fluids have been applied to mass-transfer processes, phase-transition processes, reactive systems, materials-related processes, and nanostructured materials. Some applications are already at industrial capacity, whereas others remain under development. In addition to extraction, application areas include impregnation and cleaning, multistage countercurrent separation, particle formation, coating, and reactive systems such as hydrogenation, biomass gasification, and supercritical water oxidation. Polymers are modified with supercritical fluids, and colloids and emulsions as well as nanostructured materials exhibit interesting phenomena when in contact with supercritical fluids that can be industrially exploited. For these applications to succeed, the properties of supercritical fluids in combination with the materials processed must be clearly determined and fundamental knowledge of the complex behavior must be made readily available.

  15. Disposal of drilling fluids

    SciTech Connect

    Bryson, W.R.

    1983-06-01

    Prior to 1974 the disposal of drilling fluids was not considered to be much of an environmental problem. In the past, disposal of drilling fluids was accomplished in various ways such as spreading on oil field lease roads to stabilize the road surface and control dust, spreading in the base of depressions of sandy land areas to increase water retention, and leaving the fluid in the reserve pit to be covered on closure of the pit. In recent years, some states have become concerned over the indescriminate dumping of drilling fluids into pits or unauthorized locations and have developed specific regulations to alleviate the perceived deterioration of environmental and groundwater quality from uncontrolled disposal practices. The disposal of drilling fluids in Kansas is discussed along with a newer method or treatment in drilling fluid disposal.

  16. Cocrystal Transition Points: Role of Cocrystal Solubility, Drug Solubility, and Solubilizing Agents.

    PubMed

    Lipert, Maya P; Rodríguez-Hornedo, Naír

    2015-10-05

    In this manuscript we bring together concepts that are relevant to the solubilization and thermodynamic stability of cocrystals in the presence of drug solubilizing agents. Simple equations are derived that allow calculation of cocrystal solubilization and transition point solubility. Analysis of 10 cocrystals in 6 different solubilizing agents shows that cocrystal solubilization is quantitatively predicted from drug solubilization. Drug solubilizing agents such as surfactants and lipid-based media are also shown to induce cocrystal transition points, where drug and cocrystal solubilities are equal, and above which the cocrystal solubility advantage over drug is eliminated. We have discovered that cocrystal solubility at the transition point (S*) is independent of solubilizing agent, and can be predicted from knowledge of only the aqueous solubilities of drug and cocrystal. For 1:1 cocrystals, S* = (Scocrystal,aq)(2)/Sdrug,aq. S* is a key indicator of cocrystal thermodynamic stability and establishes the upper solubility limit below which cocrystal is more soluble than the constituent drug. These findings have important implications to tailor cocrystal solubility and stability in pharmaceutical formulations from commonly available drug solubility descriptors.

  17. Persistent interface fluid syndrome.

    PubMed

    Hoffman, Richard S; Fine, I Howard; Packer, Mark

    2008-08-01

    We present an unusual case of persistent interface fluid that would not resolve despite normal intraocular pressure and corneal endothelial replacement with Descemet-stripping endothelial keratoplasty. Dissection, elevation, and repositioning of the laser in situ keratomileusis flap were required to resolve the interface fluid. Circumferential corneal graft-host margin scar formation acting as a mechanical strut may have been the cause of the intractable interface fluid.

  18. Solar heat transport fluid

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The progress made on the development and delivery of noncorrosive fluid subsystems is reported. These subsystems are to be compatible with closed-loop solar heating or combined heating and hot water systems. They are also to be compatible with both metallic and non-metallic plumbing systems. At least 100 gallons of each type of fluid recommended by the contractor will be delivered under the contract. The performance testing of a number of fluids is described.

  19. Fluid pumping system

    SciTech Connect

    Heath, R.T.; Gerlach, C.R.

    1986-05-13

    A fluid pumping system is described for use with a natural gas dehydrating system or the like having an absorber apparatus for removing water from wet natural gas to produce dry natural gas by use of a dessicant agent such as glycol, and a glycol treater apparatus for producing a source of dry glycol from wet glycol received from the absorber apparatus. The system consists of: a fluid pump means operatively connected between dry glycol source and absorber apparatus for pumping dry glycol from the dry glycol source to the absorber apparatus; a fluid operable piston motor means operatively associated with the pump means for driving the pump means and having fluid inlet passage means for receiving wet glycol from the absorber and fluid outlet passage means for delivering wet glycol to the glycol reboiler means wherein energy derived from the flow of fluid passing through the fluid inlet passage means provides the entire motivating force for the motor means and the pump means; the fluid pump means comprising a first pair of equal diameter chamber portion of a double acting piston means having a piston rod with two oppositely positioned piston heads at terminal ends thereof received within two oppositely positioned cylinders mounted on a fixed central body which slidably supports the piston rod; the fluid operable motor means comprising a second pair of equal diameter chamber portions of the double acting piston means; the effective areas of outwardly directed faces of the piston heads being substantially greater than the effective areas of inwardly directed faces of the piston heads; and a wet glycol passage shifting means associated with the fluid motor means for automatically changing the porting of the fluid motor means at the end of a piston stroke for producing reciprocal piston motion in the fluid motor means including toggle means actuated by the piston rod.

  20. Metalworking and machining fluids

    DOEpatents

    Erdemir, Ali; Sykora, Frank; Dorbeck, Mark

    2010-10-12

    Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction, prevent galling and severe wear problems on cutting and forming tools.

  1. Perioperative Fluid Therapy.

    PubMed

    Fantoni, Denise; Shih, Andre C

    2017-03-01

    Anesthesia can lead to pathophysiologic changes that dramatically alter the fluid balance of the body compartments and the intravascular space. Fluid administration can be monitored and evaluated using static and dynamic indexes. Guidelines for fluid rates during anesthesia begin with 3 mL/kg/h in cats and 5 mL/kg/h in dogs. If at all possible, patients should be stabilized and electrolyte disturbances should be corrected before general anesthesia.

  2. Current Trends in Self-Emulsifying Drug Delivery Systems (SEDDSs) to Enhance the Bioavailability of Poorly Water-Soluble Drugs.

    PubMed

    Karwal, Rohit; Garg, Tarun; Rath, Goutam; Markandeywar, Tanmay S

    2016-01-01

    The main object of the self-emulsifying drug-delivery system (SEDDS) is oral bioavailability (BA) enhancement of a poorly water-soluble drug. Low aqueous solubility and low oral BA are major concerns for formulation scientists. As many drugs are lipophilic in nature, their lower solubility and dissolution are major drawbacks for their successful formulation into oral dosage forms. More than 60% of drugs have a lipophilic nature and exhibit poor aqueous solubility. Various strategies are reported in the literature to improve the solubility and enhance BA of lipophilic drugs, including the formation of a cyclodextrin complex, solid dispersions, and micronization. SEDDSs are ideally isotropic mixtures of drug, oil, surfactant, and/or cosurfactant. SEDDSs have gained increasing attention for enhancing oral BA and reducing drug dose. SEDDSs also provide an effective and excellent solution to the various issues related to the formulation of hydrophobic drugs that have limited solubility in gastrointestinal fluid. Our major focus of this review is to highlight the importance of SEDDSs in oral BA enhancement of poorly water-soluble drugs.

  3. Thermogelling magnetorheological fluids

    NASA Astrophysics Data System (ADS)

    Shahrivar, Keshvad; de Vicente, Juan

    2014-02-01

    A novel approach is proposed for the formulation of kinetically stable magnetorheological (MR) fluids exhibiting an MR effect. Thermoresponsive carrier fluids are used which develop a sol-gel transition on increasing the temperature. Turbidity measurements, multiwave rheology and steady shear flow tests are carried out on model conventional MR fluids prepared by dispersion of carbonyl iron microparticles in triblock copolymer solutions of type PEOx-PPOy-PEOx with x = 100 and y = 65. Experiments demonstrate that the MR fluids remain stable against sedimentation in the gel phase and exhibit a very large (relative) MR effect (up to 1000%) in the sol phase.

  4. The Fluids RAP

    NASA Astrophysics Data System (ADS)

    Nedyalkov, Ivaylo

    2016-11-01

    After fifteen years of experience in rap, and ten in fluid mechanics, "I am coming here with high-Reynolds-number stamina; I can beat these rap folks whose flows are... laminar." The rap relates fluid flows to rap flows. The fluid concepts presented in the song have varying complexity and the listeners/viewers will be encouraged to read the explanations on a site dedicated to the rap. The music video will provide an opportunity to share high-quality fluid visualizations with a general audience. This talk will present the rap lyrics, the vision for the video, and the strategy for outreach. Suggestions and comments will be welcomed.

  5. Peritoneal Fluid Analysis

    MedlinePlus

    ... tests for viruses, mycobacteria ( AFB testing in identifying tuberculosis ), and parasites Adenosine deaminase – rarely ordered for detecting tuberculosis in peritoneal fluid ^ Back to top When is ...

  6. Electrorheological fluids and methods

    DOEpatents

    Green, Peter F.; McIntyre, Ernest C.

    2015-06-02

    Electrorheological fluids and methods include changes in liquid-like materials that can flow like milk and subsequently form solid-like structures under applied electric fields; e.g., about 1 kV/mm. Such fluids can be used in various ways as smart suspensions, including uses in automotive, defense, and civil engineering applications. Electrorheological fluids and methods include one or more polar molecule substituted polyhedral silsesquioxanes (e.g., sulfonated polyhedral silsesquioxanes) and one or more oils (e.g., silicone oil), where the fluid can be subjected to an electric field.

  7. Spiral fluid separator

    NASA Technical Reports Server (NTRS)

    Robertson, Glen A. (Inventor)

    1993-01-01

    A fluid separator for separating particulate matter such as contaminates is provided which includes a series of spiral tubes of progressively decreasing cross sectional area connected in series. Each tube has an outlet on the outer curvature of the spiral. As fluid spirals down a tube, centrifugal force acts to force the heavier particulate matter to the outer wall of the tube, where it exits through the outlet. The remaining, and now cleaner, fluid reaches the next tube, which is smaller in cross sectional area, where the process is repeated. The fluid which comes out the final tube is diminished of particulate matter.

  8. Fluid dynamic effects on precision cleaning with supercritical fluids

    SciTech Connect

    Phelps, M.R.; Hogan, M.O.; Silva, L.J.

    1994-06-01

    Pacific Northwest Laboratory staff have assembled a small supercritical fluids parts cleaning test stand to characterize how system dynamics affect the efficacy of precision cleaning with supercritical carbon dioxide. A soiled stainless steel coupon, loaded into a ``Berty`` autoclave, was used to investigate how changes in system turbulence and solvent temperature influenced the removal of test dopants. A pulsed laser beam through a fiber optic was used to investigate real-time contaminant removal. Test data show that cleaning efficiency is a function of system agitation, solvent density, and temperature. These data also show that high levels of cleaning efficiency can generally be achieved with high levels of system agitation at relatively low solvent densities and temperatures. Agitation levels, temperatures, and densities needed for optimal cleaning are largely contaminant dependent. Using proper system conditions, the levels of cleanliness achieved with supercritical carbon dioxide compare favorably with conventional precision cleaning methods. Additional research is currently being conducted to generalize the relationship between cleaning performance and parameters such as contaminant solubilities, mass transfer rates, and solvent agitation. These correlations can be used to optimize cleaning performance, system design, and time and energy consumption for particular parts cleaning applications.

  9. Solubility Limits in Lennard-Jones Mixtures: Effects of Disparate Molecule Geometries

    PubMed Central

    Dyer, Kippi M.; Perkyns, John S.; Pettitt, B. Montgomery

    2016-01-01

    In order to better understand general effects of the size and energy disparities between macromolecules and solvent molecules in solution, especially for macromolecular constructs self-assembled from smaller molecules, we use the first- and second-order exact bridge diagram extensions of the HNC integral equation theory to investigate single-component, binary, ternary, and quaternary mixtures of Lennard-Jones fluids. For pure fluids, we find that the HNCH3 bridge function integral equation (i.e., exact to third order in density) is necessary to quantitatively predict the pure gas and pure liquid sides of the coexistence region of the phase diagram of the Lennard-Jones fluid. For the mixtures, we find that the HNCH2 bridge function integral equation is sufficient to qualitatively predict solubility in the binary, ternary, and quaternary mixtures, up to the nominal solubility limit. The results, as limiting cases, should be useful to several problems, including accurate phase diagram predictions for complex mixtures, design of self-assembling nanostructures via solvent controls, and the solvent contributions to the conformational behavior of macromolecules in complex fluids. PMID:25621892

  10. Solubility Limits in Lennard-Jones Mixtures: Effects of Disparate Molecule Geometries.

    PubMed

    Dyer, Kippi M; Perkyns, John S; Pettitt, B Montgomery

    2015-07-23

    In order to better understand general effects of the size and energy disparities between macromolecules and solvent molecules in solution, especially for macromolecular constructs self-assembled from smaller molecules, we use the first- and second-order exact bridge diagram extensions of the HNC integral equation theory to investigate single-component, binary, ternary, and quaternary mixtures of Lennard-Jones fluids. For pure fluids, we find that the HNCH3 bridge function integral equation (i.e., exact to third order in density) is necessary to quantitatively predict the pure gas and pure liquid sides of the coexistence region of the phase diagram of the Lennard-Jones fluid. For the mixtures, we find that the HNCH2 bridge function integral equation is sufficient to qualitatively predict solubility in the binary, ternary, and quaternary mixtures, up to the nominal solubility limit. The results, as limiting cases, should be useful to several problems, including accurate phase diagram predictions for complex mixtures, design of self-assembling nanostructures via solvent controls, and the solvent contributions to the conformational behavior of macromolecules in complex fluids.

  11. Severe Hemolysis in a Patient With Erythrocytosis During Coupled Plasma Filtration Adsorption Therapy Was Prevented by Changing From Membrane-Based Technique to a Centrifuge-Based One.

    PubMed

    Fan, Rong; Wu, Buyun; Kong, Ling; Gong, Dehua

    2016-01-01

    Coupled plasma filtration adsorption (CPFA) usually adopts membrane to separate plasma from blood. Here, we reported a case with erythrocytosis experienced severe hemolysis and membrane rupture during CPFA, which was avoided by changing from membrane-based technique to a centrifuge-based one. A 66-year-old man was to receive CPFA for severe hyperbilirubinemia (total bilirubin 922 μmol/L, direct bilirubin 638 μmol/L) caused by obstruction of biliary tract. He had erythrocytosis (hemoglobin 230 g/L, hematocrit 0.634) for years because of untreated tetralogy of Fallot. Severe hemolysis and membrane rupture occurred immediately after blood entering into the plasma separator even at a low flow rate (50 mL/min) and persisted after changing a new separator. Finally, centrifugal plasma separation technique was used for CPFA in this patient, and no hemolysis occurred. After 3 sessions of CPFA, total bilirubin level decreased to 199 μmol/L with an average decline by 35% per session. Thereafter, the patient received endoscopic biliary stent implantation, and total bilirubin level returned to nearly normal. Therefore, centrifugal-based plasma separation can also be used in CPFA and may be superior to a membrane-based one in patients with hyperviscosity.

  12. Mixed Hydrotropy: Novel Science of Solubility Enhancement

    PubMed Central

    Maheshwari, R. K.; Jagwani, Y.

    2011-01-01

    Conventional furosemide tablets are practically insoluble in water, have slow onset of action (45-60 min) and poor bioavailability (39-53%), and therefore cannot be given in emergency clinical situations like hypertension or pulmonary edema. So purpose of research was to provide a fast dissolving oral dosage form of furosemide, which can provide quick onset of action by using concept of mixed hydrotropy. Initially solubility of furosemide was determined individually in 4 hydrotropic agents namely urea, sodium acetate, sodium benzoate, sodium citrate at concentration of 10, 20, 30 and 40% w/v solutions using purified water as solvent. Highest solubility was obtained in 40% sodium benzoate solution. Then different combinations of 2, 3 and 4 hydrotropic agents in different ratios were used to determine solubility, so that total concentration of hydrotropic agents was always 40%. Highest solubility was obtained in solution of urea+sodium benzoate+sodium citrate at optimum ratio of 15:20:5. This optimized combination was utilized in preparing solid dispersions by common solvent technique using distilled water as solvent. Solid dispersions were evaluated for flow properties, XRD, DSC, SEM and were also compressed to form tablets. Dissolution studies of conventional and prepared tablets were done using USP Type II apparatus. It was concluded that the concept of mixed hydrotropic solid dispersion is novel, safe and cost-effective technique for enhancing bioavailability of poorly water-soluble drugs by dissolving drug in nonionized form. The magical enhancement in solubility of furosemide is clear indication of its potential to be used in future for other poorly water-soluble drugs in which low bioavailability is major concern. PMID:22303061

  13. Redefining solubility parameters: the partial solvation parameters.

    PubMed

    Panayiotou, Costas

    2012-03-21

    The present work reconsiders a classical and universally accepted concept of physical chemistry, the solubility parameter. Based on the insight derived from modern quantum chemical calculations, a new definition of solubility parameter is proposed, which overcomes some of the inherent restrictions of the original definition and expands its range of applications. The original single solubility parameter is replaced by four partial solvation parameters reflecting the dispersion, the polar, the acidic and the basic character of the chemical compounds as expressed either in their pure state or in mixtures. Simple rules are adopted for the definition and calculation of these four parameters and their values are tabulated for a variety of common substances. In contrast, however, to the well known Hansen solubility parameters, their design and evaluation does not rely exclusively on the basic rule of "similarity matching" for solubility but it makes also use of the other basic rule of compatibility, namely, the rule of "complementarity matching". This complementarity matching becomes particularly operational with the sound definition of the acidic and basic components of the solvation parameter based on the third σ-moments of the screening charge distributions of the quantum mechanics-based COSMO-RS theory. The new definitions are made in a simple and straightforward manner, thus, preserving the strength and appeal of solubility parameter stemming from its simplicity. The new predictive method has been applied to a variety of solubility data for systems of pharmaceuticals and polymers. The results from quantum mechanics calculations are critically compared with the results from Abraham's acid/base descriptors.

  14. Low Soluble Syndecan-1 Precedes Preeclampsia

    PubMed Central

    Gandley, Robin E.; Althouse, Andrew; Jeyabalan, Arundhathi; Bregand-White, Julia M.; McGonigal, Stacy; Myerski, Ashley C.; Gallaher, Marcia; Powers, Robert W.; Hubel, Carl A.

    2016-01-01

    Introduction Syndecan-1 (Sdc1; CD138) is a major transmembrane heparan sulfate proteoglycan expressed on the extracellular, luminal surface of epithelial cells and syncytiotrophoblast, thus comprising a major component of the glycocalyx of these cells. The “soluble” (shed) form of Sdc1 has paracrine and autocrine functions and is normally produced in a regulated fashion. We compared plasma soluble Sdc1 concentrations, in relation to placental Sdc1 expression, in uncomplicated (control) and preeclamptic pregnancies. Methods We evaluated soluble Sdc1 across uncomplicated pregnancy, and between preeclamptic, gestational hypertensive and control patients at mid-pregnancy (20 weeks) and 3rd trimester by ELISA. Placental expression level of Sdc1 was compared between groups in relation to pre-delivery plasma soluble Sdc1. Participants were recruited from Magee-Womens Hospital. Results In uncomplicated pregnancy, plasma soluble Sdc1 rose significantly in the 1st trimester, and reached an approximate 50-fold increase at term compared to post pregnancy levels. Soluble Sdc1 was lower at mid-pregnancy in women who later developed preeclampsia (P<0.05), but not gestational hypertension, compared to controls, and remained lower at late pregnancy in preeclampsia (P<0.01) compared to controls. Sdc1 was prominently expressed on syncytiotrophoblast of microvilli. Syncytiotrophoblast Sdc1 immunostaining intensities, and mRNA content in villous homogenates, were lower in preeclampsia vs. controls (P<0.05). Soluble Sdc1 and Sdc1 immunostaining scores were inversely associated with systolic blood pressures, and positively correlated with infant birth weight percentile. Conclusion Soluble Sdc1 is significantly lower before the clinical onset of preeclampsia, with reduced expression of Sdc1 in the delivered placenta, suggesting a role for glycocalyx disturbance in preeclampsia pathophysiology. PMID:27299886

  15. Laboratory and field evaluation of a combined fluid-loss-control additive and gel breaker for fracturing fluids

    SciTech Connect

    Cantu, L.A.; Boyd, P.A. )

    1990-08-01

    More than 200% increase in fracture conductivity and permeability was obtained when a new degradable fluid-loss-control additive was used in place of silica flour (SF) in 40-lbm crosslinked hydroxypropyl-guar (HPG) fracturing-fluid systems. The new additive, and organic acid particulate (OAP), slowly degraded into water-soluble monomeric units at temperatures {ge}150{degrees}F after fracture stimulation experiments. The high-acid-content degradation product then acted as an excellent HPG gel breaker and effectively cleaned the proppant packs. As a fluid-loss-control additive, the measured wall-building coefficients were as good as, or better than, those of SF in crosslinked-gel, linear-gel, and N{sub 2}-foam systems. This paper summarizes a 2-year study of the evaluation and application of this new product in fracturing-fluid systems.

  16. Recovery of Minerals in Martian Soils Via Supercritical Fluid Extraction

    NASA Astrophysics Data System (ADS)

    Debelak, Kenneth A.; Roth, John A.

    2001-03-01

    We are investigating the use of supercritical fluids to extract mineral and/or carbonaceous material from Martian surface soils and its igneous crust. Two candidate supercritical fluids are carbon dioxide and water. The Martian atmosphere is composed mostly of carbon dioxide (approx. 95.3%) and could therefore provide an in-situ source of carbon dioxide. Water, although present in the Martian atmosphere at only approx. 0.03%, is also a candidate supercritical solvent. Previous work done with supercritical fluids has focused primarily on their solvating properties with organic compounds. Interestingly, the first work reported by Hannay and Hogarth at a meeting of the Royal Society of London in 1879 observed that increasing or decreasing the pressure caused several inorganic salts e.g., cobalt chloride, potassium iodide, and potassium bromide, to dissolve or precipitate in supercritical ethanol. In high-pressure boilers, silica, present in most boiler feed waters, is dissolved in supercritical steam and transported as dissolved silica to the turbine blades. As the pressure is reduced the silica precipitates onto the turbine blades eventually requiring the shutdown of the generator. In supercritical water oxidation processes for waste treatment, dissolved salts present a similar problem. The solubility of silicon dioxide (SiO2) in supercritical water is shown. The solubility curve has a shape characteristic of supercritical systems. At a high pressure (greater than 1750 atmospheres) increasing the temperature results in an increase in solubility of silica, while at low pressures, less than 400 atm., the solubility decreases as temperature increases. There are only a few studies in the literature where supercritical fluids are used in extractive metallurgy. Bolt modified the Mond process in which supercritical carbon monoxide was used to produce nickel carbonyl (Ni(CO)4). Tolley and Tester studied the solubility of titanium tetrachloride (TiCl4) in supercritical CO2

  17. Ultrasound influence on the solubility of solid dispersions prepared for a poorly soluble drug.

    PubMed

    Pereira, Simone Vieira; Colombo, Fábio Belotti; de Freitas, Luis Alexandre Pedro

    2016-03-01

    Solid dispersions have been successfully used to enhance the solubility of several poorly water soluble drugs. Solid dispersions are produced by melting hydrophilic carriers and mixing in the poorly water soluble drug. Supersaturation is obtained by quickly cooling the mixture until it solidifies, thereby entrapping the drug. The effects of using ultrasound to homogenize the molten carrier and drug mixture were studied. In particular, the increase in drug solubility for the resulting solid dispersions was analyzed. Piroxicam, which has very low water solubility, was used as a model drug. A full factorial design was used to analyze how sonication parameters affected the solubility and in vitro release of the drug. The results show that the use of ultrasound can significantly increase the solubility and dissolution rate of the piroxicam solid dispersion. Pure piroxicam presented a solubility of 13.3 μg/mL. A maximum fourfold increase in solubility, reaching 53.8 μg/mL, was observed for a solid dispersion sonicated at 19 kHz for 10 min and 475 W. The in vitro dissolution rate test showed the sonicated solid dispersion reached a maximum rate of 18%/min, a sixfold increase over the piroxicam rate of 2.9%/min. Further solid state characterization by thermal, X-ray diffraction and Fourier transform infrared analyses also showed that the sonication process, in the described conditions, did not adversely alter the drug or significantly change its polymorphic form. Ultrasound is therefore an interesting technique to homogenize drug/carrier mixtures with the objective of increasing the solubility of drugs with poor water solubility.

  18. Space Station fluid management logistics

    NASA Technical Reports Server (NTRS)

    Dominick, Sam M.

    1990-01-01

    Viewgraphs and discussion on space station fluid management logistics are presented. Topics covered include: fluid management logistics - issues for Space Station Freedom evolution; current fluid logistics approach; evolution of Space Station Freedom fluid resupply; launch vehicle evolution; ELV logistics system approach; logistics carrier configuration; expendable fluid/propellant carrier description; fluid carrier design concept; logistics carrier orbital operations; carrier operations at space station; summary/status of orbital fluid transfer techniques; Soviet progress tanker system; and Soviet propellant resupply system observations.

  19. Measurements of the solubility of metal dithiocarbamates in supercritical carbon dioxide

    SciTech Connect

    Bartle, K.D.; Cowey, C.M.; Burford, M.D.; Clifford, A.A.

    1996-10-01

    Heavy metal contamination of the environmental has been traditionally analyzed by acid digestion and organic solvent extraction methods. However, recently supercritical fluids such as carbon dioxide have been investigated as a potentially more rapid and environmentally friendly extraction procedure for metal recovery. Direct extraction of metal ions by pure supercritical carbon dioxide has previously proved ineffective as charge neutralization of the ion using a ligand is required to significantly enhance the solute solvent interactions. Commercial chelating agents such as dithiocarbamates have been extensively used in both conventional and supercritical extractions for the recovery of a wide range of heavy metal. Initial studies using diethldithiocarbamate metal complexes at low supercritical temperatures (50 {degrees}C) and pressure (100 atm.) Showed poor solubility (1x10{sup {minus}6}mol dm{sup 3}) in supercritical carbon dioxide. In this study, the solubility of Pb, Cd, Fe, Zn, and Cu dithiocarbamates were measures at both high and low supercritical fluid temperatures and pressures and a significant increase in the solubility of the metal complexes (e.g. two orders of magnitude) was achieved using 100 {degrees}C, 350 atm supercritical carbon dioxide. Increasing the alkyl chain length of the dithiocarbamate ligand was also investigated and it was shown that as the hydrocarbon content of the ligand increased and became more non-polar in nature the solubility of the corresponding metal complex increased. The results from the solubility study will be subsequently used to assists in the optimization of methods used for the extraction of metals in environmental samples.

  20. Fluids and Combustion Facility: Fluids Integrated Rack

    NASA Technical Reports Server (NTRS)

    Corban, Robert R.; Winsa, Edward A.

    1998-01-01

    The Fluids Integrated Rack (FIR) is a modular, multi-user facility to accommodate a wide variety of microgravity fluid physics science experiments on-board the US Laboratory Module of the International Space Station (ISS). The FIR is one of three racks comprising the Fluids and Combustion Facility (FCF). The FCF is being designed to increase the amount and quality of scientific data and decrease the development cost of an individual experiment relative to the era of Space Shuttle experiments. The unique, long-term, microgravity environment and long operational times on the ISS will offer experimenters the opportunity to modify experiment parameters based on their findings similar to what can be accomplished in ground laboratories. The FIR concept has evolved over time to provide a flexible, 'optics bench' approach to meet the wide variety of anticipated research needs. The FIR's system architecture presented is designed to meet the needs of the fluid physics community while operating within the constraints of the available ISS resources.

  1. Solubility of pllutonium in alkaline salt solutions

    SciTech Connect

    Hobbs, D.T.; Edwards, T.B.

    1993-02-26

    Plutonium solubility data from several studies have been evaluated. For each data set, a predictive model has been developed where appropriate. In addition, a statistical model and corresponding prediction intervals for plutonium solubility as a quadratic function of the hydroxide concentration have been developed. Because of the wide range of solution compositions, the solubility of plutonium can vary by as much as three orders of magnitude for any given hydroxide concentration and still remain within the prediction interval. Any nuclear safety assessments that depend on the maximum amount of plutonium dissolved in alkaline salt solutions should use concentrations at least as great as the upper prediction limits developed in this study. To increase the confidence in the prediction model, it is recommended that additional solubility tests be conducted at low hydroxide concentrations and with all of the other solution components involved. To validate the model for application to actual waste solutions, it is recommended that the plutonium solubilities in actual waste solutions be determined and compared to the values predicted by the quadratic model.

  2. Extraction and analysis of soluble carbohydrates.

    PubMed

    Maness, Niels

    2010-01-01

    Soluble sugars are a universal component of most living organisms and a fundamental building block in biosynthetic processes. It is no wonder that both qualitative and quantitative changes in carbohydrates often accompany plant's responses to stress. Depending on the speed of onset of stress, plant tissues can exhibit rapid and very site-specific shifts in their soluble carbohydrate pool - rapid and precise tissue collection and stabilization are necessary if analytical results are to truly represent the sugar composition at the instant of harvest. Since soluble carbohydrates are, by definition, soluble in the cell's aqueous environment, they may be analyzed directly from liquids obtained from plants or they may require extraction from the plant matrix. During extraction and prior to analysis, steps should be taken to avoid change in form or quantity of sugars by endogenous active enzyme conversion or by contaminating microbial growth. Many procedures for soluble sugar analysis exist; the choice of the most appropriate analytical protocol is ultimately dictated by the depth of information required to substantiate findings for a particular purpose.

  3. New recommendations for measuring collagen solubility.

    PubMed

    Latorre, María E; Lifschitz, Adrian L; Purslow, Peter P

    2016-08-01

    The heat-solubility of intramuscular collagen is usually conducted in 1/4 Ringer's solution at pH7.4, despite this ionic strength and pH being inappropriate for post-rigor meat. The current work studied the percentage of soluble collagen and hydrothermal isometric tension characteristics of perimysial strips on bovine semitendinosus muscles in either 1/4 Ringer's solution, distilled water, PBS, or a solution of the same salt concentration as 1/4 Ringer's but at pH5.6. Values of % soluble collagen were lower at pH7.4 than 5.6. Increasing ionic strength reduced % soluble collagen. The maximum perimysial isometric tension was independent of the bathing medium, but the percent relaxation was higher at pH7.4 than at pH5.6, and increased with ionic strength of the media. It is recommended that future measurements of collagen solubility and tests on connective tissue components of post-rigor meat should be carried out in a solution of concentrations NaCl and KCl equivalent to those in 1/4 Ringer's, but at pH5.6, a pH relevant to post-rigor meat.

  4. Melt extrusion with poorly soluble drugs.

    PubMed

    Shah, Sejal; Maddineni, Sindhuri; Lu, Jiannan; Repka, Michael A

    2013-08-30

    Melt extrusion (ME) over recent years has found widespread application as a viable drug delivery option in the drug development process. ME applications include taste masking, solid-state stability enhancement, sustained drug release and solubility enhancement. While ME can result in amorphous or crystalline solid dispersions depending upon several factors, solubility enhancement applications are centered around generating amorphous dispersions, primarily because of the free energy benefits they offer. In line with the purview of the current issue, this review assesses the utility of ME as a means of enhancing solubility of poorly soluble drugs/chemicals. The review describes major processing aspects of ME technology, definition and understanding of the amorphous state, manufacturability, analytical characterization and biopharmaceutical performance testing to better understand the strength and weakness of this formulation strategy for poorly soluble drugs. In addition, this paper highlights the potential advantages of employing a fusion of techniques, including pharmaceutical co-crystals and spray drying/solvent evaporation, facilitating the design of formulations of API exhibiting specific physico-chemical characteristics. Finally, the review presents some successful case studies of commercialized ME based products.

  5. Fluid Bubble Eliminator

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R. (Inventor); Tsao, Yow-Min (Inventor); Lee, Wenshan (Inventor)

    2005-01-01

    A gas-liquid separator uses a helical passageway to impart a spiral motion to a fluid passing therethrough. The centrifugal fore generated by the spiraling motion urges the liquid component of the fluid radially outward which forces the gas component radially inward. The gas component is then filtered through a gas-permeable, liquid-impervious membrane and discharged through a central passageway.

  6. Fluid bubble eliminator

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R. (Inventor); Tsao, Yow-Min D. (Inventor); Lee, Wenshan (Inventor)

    2005-01-01

    A gas-liquid separator uses a helical passageway to impart a spiral motion to a fluid passing therethrough. The centrifugal fore generated by the spiraling motion urges the liquid component of the fluid radially outward which forces the gas component radially inward. The gas component is then filtered through a gas-permeable, liquid-impervious membrane and discharged through a central passageway.

  7. Fluid delivery control system

    SciTech Connect

    Hoff, Brian D.; Johnson, Kris William; Algrain, Marcelo C.; Akasam, Sivaprasad

    2006-06-06

    A method of controlling the delivery of fluid to an engine includes receiving a fuel flow rate signal. An electric pump is arranged to deliver fluid to the engine. The speed of the electric pump is controlled based on the fuel flow rate signal.

  8. Time Independent Fluids

    ERIC Educational Resources Information Center

    Collyer, A. A.

    1973-01-01

    Discusses theories underlying Newtonian and non-Newtonian fluids by explaining flow curves exhibited by plastic, shear-thining, and shear-thickening fluids and Bingham plastic materials. Indicates that the exact mechanism governing shear-thickening behaviors is a problem of further study. (CC)

  9. Fluid Power Technician

    ERIC Educational Resources Information Center

    Moore, Pam

    2008-01-01

    Fluid power technicians, sometimes called hydraulic and pneumatic technicians, work with equipment that utilizes the pressure of a liquid or gas in a closed container to transmit, multiply, or control power. Working under the supervision of an engineer or engineering staff, they assemble, install, maintain, and test fluid power equipment.…

  10. Fluid-loss control

    SciTech Connect

    Crowe, C.W.; Trittipo, B.L. ); Hutchinson, B.H. )

    1989-08-01

    Acid fluid loss is extremely difficult to control and is generally considered to be the major factor limiting the effectiveness of acid fracturing treatments. Chemical erosion of fracture faces and the development of wormholes are largely responsible for the reduced efficiency of acid fracturing fluids. The creation of acid wormholes increases the effective area from which leakoff occurs, thus reducing the acid hydraulic efficiency. Once wormholes form, most acid fluid loss originates from these wormholes rather than penetrating uniformly into the fracture face. Methods of acid fluid-loss control are discussed and evaluated with an improved fluid-loss test procedure. This procedure uses limestone cores of sufficient length to contain wormhole growth. Studies demonstrate that if wormhole growth can be controlled, acid fluid loss approaches that of nonreactive fluids. An improved acid fracturing fluid having unique rheological characteristics is described. This acid has a low initial viscosity but temporarily becomes extremely viscous during leakoff. This high leakoff viscosity blocks wormhole development and prevents acid entry into natural fractures. After the treatment, spent-acid viscosity declines rapidly to ensure easier cleanup.

  11. FLUID SELECTING APPARATUS

    DOEpatents

    Stinson, W.J.

    1958-09-16

    A valve designed to selectively sample fluids from a number of sources is described. The valve comprises a rotatable operating lever connected through a bellows seal to a rotatable assembly containing a needle valve, bearings, and a rotational lock. The needle valve is connected through a flexible tube to the sample fluid outlet. By rotating the lever the needle valve is placed over . one of several fluid sources and locked in position so that the fluid is traasferred through the flexible tubing and outlet to a remote sampling system. The fluids from the nonselected sources are exhausted to a waste line. This valve constitutes a simple, dependable means of selecting a sample from one of several scurces.

  12. Fluid structure interaction

    NASA Astrophysics Data System (ADS)

    Komatsu, K.

    A few nonflow field problems are considered, taking into account mainly fluid-shell dynamic interaction and fluid-solid impact. Fluid-shell systems are used as models for sloshing and POGO (structure-propulsion coupling oscillation) in liquid rockets, floating lids of oil tanks, large tanks containing fluid, nuclear containment vessels, and head injury studies in biomechanics. The study of structure-water impact finds applications in the problems associated with water landings of reentry vehicles, water entry of torpedoes, and slamming of ships in heavy seas. At least three different methods can be used in handling wet structures. Attention is given to the method which treats fluid by boundary elements and structure by finite elements.

  13. Fluid blade disablement tool

    DOEpatents

    Jakaboski, Juan-Carlos [Albuquerque, NM; Hughs, Chance G [Albuquerque, NM; Todd, Steven N [Rio Rancho, NM

    2012-01-10

    A fluid blade disablement (FBD) tool that forms both a focused fluid projectile that resembles a blade, which can provide precision penetration of a barrier wall, and a broad fluid projectile that functions substantially like a hammer, which can produce general disruption of structures behind the barrier wall. Embodiments of the FBD tool comprise a container capable of holding fluid, an explosive assembly which is positioned within the container and which comprises an explosive holder and explosive, and a means for detonating. The container has a concavity on the side adjacent to the exposed surface of the explosive. The position of the concavity relative to the explosive and its construction of materials with thicknesses that facilitate inversion and/or rupture of the concavity wall enable the formation of a sharp and coherent blade of fluid advancing ahead of the detonation gases.

  14. Constraining the dark fluid

    SciTech Connect

    Kunz, Martin; Liddle, Andrew R.; Parkinson, David; Gao Changjun

    2009-10-15

    Cosmological observations are normally fit under the assumption that the dark sector can be decomposed into dark matter and dark energy components. However, as long as the probes remain purely gravitational, there is no unique decomposition and observations can only constrain a single dark fluid; this is known as the dark degeneracy. We use observations to directly constrain this dark fluid in a model-independent way, demonstrating, in particular, that the data cannot be fit by a dark fluid with a single constant equation of state. Parametrizing the dark fluid equation of state by a variety of polynomials in the scale factor a, we use current kinematical data to constrain the parameters. While the simplest interpretation of the dark fluid remains that it is comprised of separate dark matter and cosmological constant contributions, our results cover other model types including unified dark energy/matter scenarios.

  15. Microgravity Fluid Management Symposium

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The NASA Microgravity Fluid Management Symposium, held at the NASA Lewis Research Center, September 9 to 10, 1986, focused on future research in the microgravity fluid management field. The symposium allowed researchers and managers to review space applications that require fluid management technology, to present the current status of technology development, and to identify the technology developments required for future missions. The 19 papers covered three major categories: (1) fluid storage, acquisition, and transfer; (2) fluid management applications, i.e., space power and thermal management systems, and environmental control and life support systems; (3) project activities and insights including two descriptions of previous flight experiments and a summary of typical activities required during development of a shuttle flight experiment.

  16. Influence of Polymer Molecular Weight on Drug-Polymer Solubility: A Comparison between Experimentally Determined Solubility in PVP and Prediction Derived from Solubility in Monomer.

    PubMed

    Knopp, Matthias Manne; Olesen, Niels Erik; Holm, Per; Langguth, Peter; Holm, René; Rades, Thomas

    2015-09-01

    In this study, the influence of polymer molecular weight on drug-polymer solubility was investigated using binary systems containing indomethacin (IMC) and polyvinylpyrrolidone (PVP) of different molecular weights. The experimental solubility in PVP, measured using a differential scanning calorimetry annealing method, was compared with the solubility calculated from the solubility of the drug in the liquid analogue N-vinylpyrrolidone (NVP). The experimental solubility of IMC in the low-molecular-weight PVP K12 was not significantly different from that in the higher molecular weight PVPs (K25, K30, and K90). The calculated solubilities derived from the solubility in NVP (0.31-0.32 g/g) were found to be lower than those experimentally determined in PVP (0.38-0.40 g/g). Nevertheless, the similarity between the values indicates that the analogue solubility can provide valuable indications on the solubility in the polymer. Hence, if a drug is soluble in an analogue of the polymer, it is most likely also soluble in the polymer. In conclusion, the solubility of a given drug-polymer system is determined by the strength of the drug-polymer interactions rather than the molecular weight of the polymer. Therefore, during the first screenings for drug solubility in polymers, only one representative molecular weight per polymer is needed.

  17. Prediction of seawater solubility of aromatic compounds

    SciTech Connect

    Hashimoto, Y.; Tokura, K.; Kishi, H.; Strachan, W.M.J.

    1984-01-01

    The salting-out effect by seawater constituents on the water solubilities of 11 aromatic compounds, anthracene, pyrene, phenanthrene, biphenyl, naphthalene, p-nitrotoluene, p-toluidine, o-nitrophenol, m-nitrophenol, p-nitrophenol and phenol was investigated. A best fit equation for the salting-out parameters, K, and distilled water solubilities, S/sub 0/, at 20/sup 0/C was found to be K = -0.0298 log S/sub 0/ + 0.114. Seawater solubilities, S, predicted for solutions of ionic strength, I, using the equation log S = (0.0298 I + 1)logS/sub 0/ - 0.114 I were in agreement with observed values within 13% and there were no significant differences between values from the Pacific Ocean seawater and those from 35% NaCl solutions. It was concluded that dissolved organic matter in seawater had an insignificant effect for the test chemicals.

  18. Diffusion and solubility of oxygen in silver

    NASA Technical Reports Server (NTRS)

    Eichenauer, W.; Miller, G.

    1985-01-01

    The diffusion and solubility of oxygen in Ag in the temperature range between 412 and 862 C was determined. The following interpolation formula was found for the solubility: L = 8.19.1/100.exp(-11 860/RT)Mol O2/g.At.Ag.at 1/.5. The process obeys the Sieverts square root law within the limits of error. The dissolution of oxygen in Ag may be accompanied by the dissociation of the oxygen molecules into atoms. The tests on Ag-foils reveal that below a temperature of about 500 C a higher solubility is simulated by the adsorption of oxygen. The diffusion coefficient of oxygen in silver obeys the following equation: D = 2.72.1/100.exp(-11 000/RT)sq cm/s. The relatively low activation energy of 11 kcal/g.At suggests that the diffusion of oxygen takes places over interstitial sites.

  19. Gaseous Sulfate Solubility in Glass: Experimental Method

    SciTech Connect

    Bliss, Mary

    2013-11-30

    Sulfate solubility in glass is a key parameter in many commercial glasses and nuclear waste glasses. This report summarizes key publications specific to sulfate solubility experimental methods and the underlying physical chemistry calculations. The published methods and experimental data are used to verify the calculations in this report and are expanded to a range of current technical interest. The calculations and experimental methods described in this report will guide several experiments on sulfate solubility and saturation for the Hanford Waste Treatment Plant Enhanced Waste Glass Models effort. There are several tables of sulfate gas equilibrium values at high temperature to guide experimental gas mixing and to achieve desired SO3 levels. This report also describes the necessary equipment and best practices to perform sulfate saturation experiments for molten glasses. Results and findings will be published when experimental work is finished and this report is validated from the data obtained.

  20. AW-101 entrained solids - Solubility versus temperature

    SciTech Connect

    GJ Lumetta; RC Lettau; GF Piepel

    2000-03-31

    This report describes the results of a test conducted by Battelle to assess the solubility of the solids entrained in the diluted AW-101 low-activity waste (LAW) sample. BNFL requested Battelle to dilute the AW-1-1 sample using de-ionized water to mimic expected plant operating conditions. BNFL further requested Battelle to assess the solubility of the solids present in the diluted AW-101 sample versus temperature conditions of 30, 40, and 50 C. BNFL requested these tests to assess the composition of the LAW supernatant and solids versus expected plant-operating conditions. The work was conducted according to test plan BNFL-TP-29953-7, Rev. 0, Determination of the Solubility of LAW Entrained Solids. The test went according to plan, with no deviations from the test plan.

  1. Cosolvency of dimethyl isosorbide for steroid solubility.

    PubMed

    Zia, H; Ma, J K; O'Donnell, J P; Luzzi, L A

    1991-04-01

    Dimethyl isosorbide (DMI), which is currently under investigation for its potential use as a pharmaceutical vehicle and drug permeation enhancer, is a water-miscible liquid with relatively low viscosity. The solubilization behavior of DMI as a cosolvent for nonpolar drugs was characterized via dielectric constant measurements of binary solvent systems containing DMI and either water, propylene glycol (PG), or polyethylene glycol (PEG). Evidence from the dielectric constant profiles and NMR studies suggest that DMI undergoes complexation with water and PG, but not with PEG, through hydrogen bonding interactions. The solvent complexation exhibited a major effect on the solubilities of prednisone, dexamethasone, and prednisolone in the mixed solvent systems. Maximum solubility of each drug was found to occur near a DMI/water or DMI/PG concentration ratio of 1:2. In the DMI-PEG mixed system, while there is no apparent interaction between DMI and PEG molecules, the solubility of prednisone was found to increase with decreasing dielectric constant.

  2. Water-Soluble Metallocene-Containing Polymers.

    PubMed

    Alkan, Arda; Wurm, Frederik R

    2016-09-01

    Metallocenes are organometallic compounds with reversible redox profiles and tunable oxidation and reduction potentials, depending on the metal and substituents at the cyclopentadienyl rings. Metallocenes have been introduced in macromolecules to combine the redox-activity with polymer properties. There are many examples of such hydrophobic polymer materials, but much fewer water-soluble examples are found scattered across the polymer literature. However, in terms of drug delivery and other biological applications, water solubility is essential. For this very reason, all the synthetic routes to water-soluble metallocene containing polymers are collected and discussed here. The focus is on neutral ferrocene- and ruthenocene-containing and charged cobaltocenium-containing macromolecules (i.e., symmetrical sandwich complexes). The synthetic protocols, self-assembly behavior, and other benefits of the obtained materials are discussed.

  3. [Soluble nitrogen and soluble phosphorus dynamics during foliar litter decomposition in winter in alinine forest streams].

    PubMed

    Zhang, Chuan; Yang, Wan-qin; Yue, Kai; Huang, Chun-ping; Peng, Yan; Wu, Fu-zhong

    2015-06-01

    In order to understand the dynamic pattern of soluble nitrogen and soluble phosphorus in the headwater streams during the process of litter decomposition in winter, a field experiment using litterbag method was conducted in an alpine forest in Western Sichuan, China. The foliar litter of two dominant canopy trees (Sabina saltuaria, and Larix mastersiana) and two shrubs (Salix paraplesia and Rhododendron lapponicum) were selected. The litterbags were placed in a headwater stream, river, riparian zone and closed canopy, and sampled in different freezing-thawing periods of winter (pre-freezing period, freezing period and thawing period). The results indicated that the soluble nitrogen content of foliar litter showed little changes over a whole winter decomposition regardless of species. In contrast, the soluble phosphorus content displayed the order as river < stream < riparian zone < closed canopy, and showed a decrease tendency in stream, river and riparian, although little changes under closed canopy over a whole winter decomposition. Correlation analysis suggested that the dynamics of soluble phosphorus content significantly correlated to the average temperature, positive accumulated temperature, negative accumulated temperature and flow velocity during the decomposition in winter. The dynamics of soluble nitrogen content only exhibited significant correlations with positive accumulated temperature. Additionally, litter quality (species) also controlled the dynamics of soluble nitrogen and soluble phosphorus content as litter decomposition proceeded. The results implied that soluble phosphorus could be more liable to loss in streams and rivers during litter decomposition compared with soluble nitrogen, which could further provide some new ideas in understanding nitrogen and phosphorus cycling in this alpine forest.

  4. Dissolution of beryllium in artificial lung alveolar macrophage phagolysosomal fluid.

    PubMed

    Stefaniak, Aleksandr B; Virji, M Abbas; Day, Gregory A

    2011-05-01

    Dissolution of a lung burden of poorly soluble beryllium particles is hypothesized to be necessary for development of chronic beryllium lung disease (CBD) in humans. As such, particle dissolution rate must be sufficient to activate the lung immune response and dissolution lifetime sufficient to maintain chronic inflammation for months to years to support development of disease. The purpose of this research was to investigate the hypothesis that poorly soluble beryllium compounds release ions via dissolution in lung fluid. Dissolution kinetics of 17 poorly soluble particulate beryllium materials that span extraction through ceramics machining (ores, hydroxide, metal, copper-beryllium [CuBe] fume, oxides) and three CuBe alloy reference materials (chips, solid block) were measured over 31 d using artificial lung alveolar macrophage phagolysosomal fluid (pH 4.5). Differences in beryllium-containing particle physicochemical properties translated into differences in dissolution rates and lifetimes in artificial phagolysosomal fluid. Among all materials, dissolution rate constant values ranged from 10(-5) to 10(-10)gcm(-2)d(-1) and half-times ranged from tens to thousands of days. The presence of magnesium trisilicate in some beryllium oxide materials may have slowed dissolution rates. Materials associated with elevated prevalence of CBD had faster beryllium dissolution rates [10(-7)-10(-8)gcm(-2)d(-1)] than materials not associated with elevated prevalence (p<0.05).

  5. Solubilities of krypton and xenon in dichlorodifluoromethane

    SciTech Connect

    Shaffer, J.H.; Shockley, W.E.; Greene, C.W.

    1984-07-01

    The solubility behavior of krypton and xenon in dichlorodifluoromethane was investigated for the Consolidated Fuel Reprocessing Program (CFRP) in support of the fluorocarbon absorption process. The solubility data derived from solute radioisotopes had uncertainties of approx. 0.1%. Values for Henry's law constants were initially determined under equilibrium conditions at infinite solute dilution. Based on these results, the study was extended to finite solute concentrations. Nonidealities in the two binary systems were expressed as gas phase fugacity coefficients for each solute at 10/sup 0/ intervals over the range -30 to +50/sup 0/C. 22 references, 4 figures, 2 tables.

  6. Laboratory and Field Evaluation of Fluid-Loss Additive Systems Used in the Williston Basin

    SciTech Connect

    Woo, G.T.; Cramer, D.D.

    1984-05-01

    Many formations in the Williston Basin are naturally fractured limestones and dolomites. Naturally fractured reservoirs are typically the most difficult to maintain control of fracturing fluid leakoff. Treatments in the Mission Canyon, Midale and Ratcliffe formations of the Madison Group have had high fracturing fluid leakoffs. Polymer/inert solids mixtures, 100 mesh sand, silica flour and oil-soluble resins have been used in an attempt to control fluid loss. These additives have not consistently solved the problem of excessive fluid loss, and frequent screenouts, gel-outs or pressure-outs have resulted. A laboratory simulation of naturally fractured reservoir leakoff was employed to evaluate the efficiency of ten fluid loss additive systems. Tapered-slot fluid loss tests and proppant pack damage tests were performed using each additive system. Five fluid loss additive systems were identified which performed well in both tests. This paper also summarizes the results of a field evaluation of nine of the original ten fluid loss additive systems used in 70 wells in the Madison Group. Two fluid loss additive systems, a mixture of silica flour and 100 mesh sand, and a mixture of oil-soluble resin (nominal 250 mesh) and 100 mesh sand, performed well in the laboratory tests and had a high success rate in the field.

  7. Connecting the solubility and CCN activation of complex organic aerosols: a theoretical study using solubility distributions

    NASA Astrophysics Data System (ADS)

    Riipinen, I.; Rastak, N.; Pandis, S. N.

    2015-06-01

    We present a theoretical study investigating the cloud activation of multicomponent organic particles. We modeled these complex mixtures using solubility distributions (analogous to volatility distributions in the VBS, i.e., volatility basis set, approach), describing the mixture as a set of surrogate compounds with varying water solubilities in a given range. We conducted Köhler theory calculations for 144 different mixtures with varying solubility range, number of components, assumption about the organic mixture thermodynamics and the shape of the solubility distribution, yielding approximately 6000 unique cloud condensation nucleus (CCN)-activation points. The results from these comprehensive calculations were compared to three simplifying assumptions about organic aerosol solubility: (1) complete dissolution at the point of activation; (2) combining the aerosol solubility with the molar mass and density into a single effective hygroscopicity parameter κ; and (3) assuming a fixed water-soluble fraction ϵeff. The complete dissolution was able to reproduce the activation points with a reasonable accuracy only when the majority (70-80%) of the material was dissolved at the point of activation. The single-parameter representations of complex mixture solubility were confirmed to be powerful semi-empirical tools for representing the CCN activation of organic aerosol, predicting the activation diameter within 10% in most of the studied supersaturations. Depending mostly on the condensed-phase interactions between the organic molecules, material with solubilities larger than about 0.1-100 g L-1 could be treated as soluble in the CCN activation process over atmospherically relevant particle dry diameters and supersaturations. Our results indicate that understanding the details of the solubility distribution in the range of 0.1-100 g L-1 is thus critical for capturing the CCN activation, while resolution outside this solubility range will probably not add

  8. Fluid sampling tool

    DOEpatents

    Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.

    1999-05-25

    A fluid sampling tool for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall.

  9. FRACTURING FLUID CHARACTERIZATION FACILITY

    SciTech Connect

    Subhash Shah

    2000-08-01

    Hydraulic fracturing technology has been successfully applied for well stimulation of low and high permeability reservoirs for numerous years. Treatment optimization and improved economics have always been the key to the success and it is more so when the reservoirs under consideration are marginal. Fluids are widely used for the stimulation of wells. The Fracturing Fluid Characterization Facility (FFCF) has been established to provide the accurate prediction of the behavior of complex fracturing fluids under downhole conditions. The primary focus of the facility is to provide valuable insight into the various mechanisms that govern the flow of fracturing fluids and slurries through hydraulically created fractures. During the time between September 30, 1992, and March 31, 2000, the research efforts were devoted to the areas of fluid rheology, proppant transport, proppant flowback, dynamic fluid loss, perforation pressure losses, and frictional pressure losses. In this regard, a unique above-the-ground fracture simulator was designed and constructed at the FFCF, labeled ''The High Pressure Simulator'' (HPS). The FFCF is now available to industry for characterizing and understanding the behavior of complex fluid systems. To better reflect and encompass the broad spectrum of the petroleum industry, the FFCF now operates under a new name of ''The Well Construction Technology Center'' (WCTC). This report documents the summary of the activities performed during 1992-2000 at the FFCF.

  10. Micromachined Fluid Inertial Sensors

    PubMed Central

    Liu, Shiqiang; Zhu, Rong

    2017-01-01

    Micromachined fluid inertial sensors are an important class of inertial sensors, which mainly includes thermal accelerometers and fluid gyroscopes, which have now been developed since the end of the last century for about 20 years. Compared with conventional silicon or quartz inertial sensors, the fluid inertial sensors use a fluid instead of a solid proof mass as the moving and sensitive element, and thus offer advantages of simple structures, low cost, high shock resistance, and large measurement ranges while the sensitivity and bandwidth are not competitive. Many studies and various designs have been reported in the past two decades. This review firstly introduces the working principles of fluid inertial sensors, followed by the relevant research developments. The micromachined thermal accelerometers based on thermal convection have developed maturely and become commercialized. However, the micromachined fluid gyroscopes, which are based on jet flow or thermal flow, are less mature. The key issues and technologies of the thermal accelerometers, mainly including bandwidth, temperature compensation, monolithic integration of tri-axis accelerometers and strategies for high production yields are also summarized and discussed. For the micromachined fluid gyroscopes, improving integration and sensitivity, reducing thermal errors and cross coupling errors are the issues of most concern. PMID:28216569

  11. Fluid sampling tool

    DOEpatents

    Garcia, A.R.; Johnston, R.G.; Martinez, R.K.

    1999-05-25

    A fluid sampling tool is described for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall. 6 figs.

  12. Micromachined Fluid Inertial Sensors.

    PubMed

    Liu, Shiqiang; Zhu, Rong

    2017-02-14

    Micromachined fluid inertial sensors are an important class of inertial sensors, which mainly includes thermal accelerometers and fluid gyroscopes, which have now been developed since the end of the last century for about 20 years. Compared with conventional silicon or quartz inertial sensors, the fluid inertial sensors use a fluid instead of a solid proof mass as the moving and sensitive element, and thus offer advantages of simple structures, low cost, high shock resistance, and large measurement ranges while the sensitivity and bandwidth are not competitive. Many studies and various designs have been reported in the past two decades. This review firstly introduces the working principles of fluid inertial sensors, followed by the relevant research developments. The micromachined thermal accelerometers based on thermal convection have developed maturely and become commercialized. However, the micromachined fluid gyroscopes, which are based on jet flow or thermal flow, are less mature. The key issues and technologies of the thermal accelerometers, mainly including bandwidth, temperature compensation, monolithic integration of tri-axis accelerometers and strategies for high production yields are also summarized and discussed. For the micromachined fluid gyroscopes, improving integration and sensitivity, reducing thermal errors and cross coupling errors are the issues of most concern.

  13. The effect of the cation alkyl chain branching on mutual solubilities with water and toxicities

    PubMed Central

    Kurnia, Kiki A.; Sintra, Tânia E.; Neves, Catarina M. S. S.; Shimizu, Karina; Lopes, José N. Canongia; Gonçalves, Fernando; Ventura, Sónia P. M.; Freire, Mara G.; Santos, Luís M. N. B. F.; Coutinho, João A. P.

    2014-01-01

    The design of ionic liquids has been focused on the cation-anion combinations but other more subtle approaches can be used. In this work the effect of the branching of the cation alkyl chain on the design of ionic liquids (ILs) is evaluated. The mutual solubilities with water and toxicities of a series of bis(trifluoromethylsulfonyl)-based ILs, combined with imidazolium, pyridinium, pyrrolidinium, and piperidinium cations with linear or branched alkyl chains, are reported. The mutual solubility measurements were carried out in the temperature range from (288.15 to 323.15) K. From the obtained experimental data, the thermodynamic properties of the solution (in the water-rich phase) were determined and discussed. The COnductor like Screening MOdel for Real Solvents (COSMO-RS) was used to predict the liquid-liquid equilibrium. Furthermore, molecular dynamic simulations were also carried out aiming to get a deeper understanding of these fluids at the molecular level. The results show that the increase in the number of atoms at the cation ring (from five to six) leads to a decrease in the mutual solubilities with water while increasing their toxicity, and as expected from the well-established relationship between toxicities and hydrophobicities of ILs. The branching of the alkyl chain was observed to decrease the water solubility in ILs, while increasing the ILs solubility in water. The inability of COSMO-RS to correctly predict the effect of branching alkyl chains toward water solubility on them was confirmed using molecular dynamic simulations to be due to the formation of nano-segregated structures of the ILs that are not taken into account by the COSMO-RS model. In addition, the impact of branched alkyl chains on the toxicity is shown to be not trivial and to depend on the aromatic nature of the ILs. PMID:25119425

  14. Fundamentals of fluid sealing

    NASA Technical Reports Server (NTRS)

    Zuk, J.

    1976-01-01

    The fundamentals of fluid sealing, including seal operating regimes, are discussed and the general fluid-flow equations for fluid sealing are developed. Seal performance parameters such as leakage and power loss are presented. Included in the discussion are the effects of geometry, surface deformations, rotation, and both laminar and turbulent flows. The concept of pressure balancing is presented, as are differences between liquid and gas sealing. Mechanisms of seal surface separation, fundamental friction and wear concepts applicable to seals, seal materials, and pressure-velocity (PV) criteria are discussed.

  15. Fundamentals of fluid lubrication

    NASA Technical Reports Server (NTRS)

    Hamrock, Bernard J.

    1991-01-01

    The aim is to coordinate the topics of design, engineering dynamics, and fluid dynamics in order to aid researchers in the area of fluid film lubrication. The lubrication principles that are covered can serve as a basis for the engineering design of machine elements. The fundamentals of fluid film lubrication are presented clearly so that students that use the book will have confidence in their ability to apply these principles to a wide range of lubrication situations. Some guidance on applying these fundamentals to the solution of engineering problems is also provided.

  16. Geophysical fluid flow experiment

    NASA Technical Reports Server (NTRS)

    Broome, B. G.; Fichtl, G.; Fowlis, W.

    1979-01-01

    The essential fluid flow processes associated with the solar and Jovian atmospheres will be examined in a laboratory experiment scheduled for performance on Spacelab Missions One and Three. The experimental instrumentation required to generate and to record convective fluid flow is described. Details of the optical system configuration, the lens design, and the optical coatings are described. Measurement of thermal gradient fields by schlieren techniques and measurement of fluid flow velocity fields by photochromic dye tracers is achieved with a common optical system which utilizes photographic film for data recording. Generation of the photochromic dye tracers is described, and data annotation of experimental parameters on the film record is discussed.

  17. Space Station fluid resupply

    NASA Astrophysics Data System (ADS)

    Winters, Al

    Viewgraphs on space station fluid resupply are presented. Space Station Freedom is resupplied with supercritical O2 and N2 for the ECLSS and USL on a 180 day resupply cycle. Resupply fluids are stored in the subcarriers on station between resupply cycles and transferred to the users as required. ECLSS contingency fluids (O2 and N2) are supplied and stored on station in a gaseous state. Efficiency and flexibility are major design considerations. Subcarrier approach allows multiple manifest combinations. Growth is achieved by adding modular subcarriers.

  18. Multiphase fluid characterization system

    SciTech Connect

    Sinha, Dipen N.

    2014-09-02

    A measurement system and method for permitting multiple independent measurements of several physical parameters of multiphase fluids flowing through pipes are described. Multiple acoustic transducers are placed in acoustic communication with or attached to the outside surface of a section of existing spool (metal pipe), typically less than 3 feet in length, for noninvasive measurements. Sound speed, sound attenuation, fluid density, fluid flow, container wall resonance characteristics, and Doppler measurements for gas volume fraction may be measured simultaneously by the system. Temperature measurements are made using a temperature sensor for oil-cut correction.

  19. Magnetic Fluids--Part 1.

    ERIC Educational Resources Information Center

    Hoon, S. R.; Tanner, B. K.

    1985-01-01

    Basic physical concepts of importance in understanding magnetic fluids (fine ferromagnetic particles suspended in a liquid) are discussed. They include home-made magnetic fluids, stable magnetic fluids, and particle surfactants. (DH)

  20. Modern supercritical fluid technology for food applications.

    PubMed

    King, Jerry W

    2014-01-01

    This review provides an update on the use of supercritical fluid (SCF) technology as applied to food-based materials. It advocates the use of the solubility parameter theory (SPT) for rationalizing the results obtained when employing sub- and supercritical media to food and nutrient-bearing materials and for optimizing processing conditions. Total extraction and fractionation of foodstuffs employing SCFs are compared and are illustrated by using multiple fluids and unit processes to obtain the desired food product. Some of the additional prophylactic benefits of using carbon dioxide as the processing fluid are explained and illustrated with multiple examples of commercial products produced using SCF media. I emphasize the role of SCF technology in the context of environmentally benign and sustainable processing, as well as its integration into an overall biorefinery concept. Conclusions are drawn in terms of current trends in the field and future research that is needed to secure new applications of the SCF platform as applied in food science and technology.

  1. Detection of pulmonary and extrapulmonary tuberculosis patients with the 38-kilodalton antigen from Mycobacterium tuberculosis in a rapid membrane-based assay.

    PubMed Central

    Zhou, A T; Ma, W L; Zhang, P Y; Cole, R A

    1996-01-01

    A rapid membrane-based serologic assay using the 38-kDa antigen from Mycobacterium tuberculosis for the diagnosis of tuberculosis (TB) was evaluated with 201 patients with pulmonary TB, 67 patients with extrapulmonary TB, 79 Mycobacterium bovis BCG-vaccinated healthy controls, and 77 non-TB respiratory patients. The overall sensitivities, specificities, and positive and negative predictive values were, respectively, 92, 92, 84, and 96% for sputum-positive TB patients; 70, 92, 87, and 79% for sputum-negative TB patients; and 76, 92, 80, and 90% for extrapulmonary-TB patients. Only 2% (1 of 44) of the healthy control BCG-vaccinated subjects gave weak positive signals in the assay, indicating that this rapid serological assay is a valuable aid in clinical diagnosis for both pulmonary and extrapulmonary TB. PMID:8705680

  2. The Effect of Nano-Morphology Modification Using an Amphiphilic Polymer on the Proton Conductivity of Composite Membrane for a Polymer Membrane-Based Fuel Cell.

    PubMed

    Roh, Sung-Hee; Rho, Seon-Gyun; Kim, Sang-Chai; Kim, Ju-Young; Jung, Ho-Young

    2016-02-01

    The effect of morphology modification using an amphiphilic polymer on the proton conductivity of composite membrane for a polymer membrane-based fuel cell was investigated. The proton conductivity of each composite membrane was analyzed by the electrochemical impedance spectroscopy (EIS). The morphological change was confirmed by scanning electron microscope (SEM). In the composite membrane, the proton conductive component was sulfonated poly(ether ether ketone) (sPEEK), while the nonconductive component was poly(vinylidenedifluoride) and the amphiphilic polymer as a compatibilizer was urethane acrylate non-ionomer (UAN). UAN as a compatibilizer improved the interfacial stability between sPEEK and PVdF polymers, even though two polymers were apparently immiscible. The homogeneous distribution of sPEEK and PVdF domains in the composite membrane was obtained with the introduction of UAN due to the amphiphilicity. Therefore, it was found that the proton conductivity of the composite membrane increased with the incorporation of UAN as a compatibilizer.

  3. The Nakhlite Secondary Mineralogy and Fluid.

    NASA Astrophysics Data System (ADS)

    Bridges, J.; Schwenzer, S. P.

    2011-12-01

    The nakhlite olivine clinopyroxenite meteorites preserve a detailed record of water-rock interaction on Mars. Detailed knowledge of the mineralogy of the secondary assemblages [1,2,3] now allow us to accurately model the fluid from which it was deposited [4]. This combined mineralogical and fluid characterisation provides constraints on the near surface conditions associated with the similar assemblages identified e.g. with CRISM on the surface of Mars [5]. Brittle fractures in the olivine grains of the Lafayette nakhlite are filled with a zoned assemblage of siderite at the margins of veins, then phyllosilicate, and finally silicate gel in the centre of the veins [2,3]. The mesostasis also contains parts of this alteration assemblage. The silicate gel is the most abundant secondary phase within the nakhlites. The phyllosilicate in Lafayette is a complex mixture of 2:1 and 1:1 phyllosilicate: Fe smectite and Fe serpentine. Soluble salts are also present although some of these e.g. in Y000749 are terrestrial contamination. The gel has a similar composition to the Lafayette phyllosilicate, with its amorphous nature shown by HRTEM [3]. The carbonate and gel compositions vary between in respect to their position in the nakhlite cumulate pile [2,3]. For instance, Lafayette and NWA998, which sample the bottom of the nakhlite cumulate pile [6] near the fluid source have a high gel Mg#, and the nakhlites which sample levels closer to the martian surface, a lower Mg#. We have used CHILLER [7] to model the hydrothermal brine from which the secondary minerals were deposited. The starting materials are derived from a mixture of Lafayette bulk, Lafayette olivine and mesostasis. The early parts of the fluid's history with formation of the siderite are associated with dissolution of the olivine. The carbonate compositions in the nakhlites suggest water/rock (W/R) ratios ~10, 100oC, pH 5.5. As the fluid evolved the bulk and mesostasis become components of the dissolved rock

  4. Water-soluble constituents of dill.

    PubMed

    Ishikawa, Toru; Kudo, Masato; Kitajima, Junichi

    2002-04-01

    From the water-soluble portion of the methanol extract of dill (fruit of Anethum graveolens L.), which has been used as a spice and medicine, thirty-three compounds, including a new monoterpenoid, six new monoterpenoid glycosides, a new aromatic compound glucoside and a new alkyl glucoside were obtained. Their structures were clarified by spectral investigation.

  5. Golden rule for buttressing vulnerable soluble proteins.

    PubMed

    Fernández, Ariel; Berry, R Stephen

    2010-05-07

    Local weaknesses in the structure of soluble proteins have received little attention. The structure may be inherently weak at sites where hydration of the protein backbone is locally hampered by formation of an intramolecular hydrogen bond which in turn is not fully stabilized through burial within a hydrophobic environment. The result is insufficient compensation for the thermodynamic cost of dehydrating the backbone polar groups. This work shows that these structural deficiencies, the unburied backbone hydrogen bonds, are compensated in natural proteins by disulfide bonds that are needed to maintain the structural integrity. Examination of all PDB-reported soluble structures reveals that, after suitable normalization, the number of disulfide bonds, X, correlates tightly with the number of unburied backbone hydrogen bonds, Y, beyond the baseline level Y = 20, revealing a simple balance relation: Y = 5X + 20. This equation introduces a 1:5 ratio associated with the buttressing of soluble proteins with structural deficiencies. The results are justified on thermodynamic grounds and have implications for biomolecular engineering as they introduce two constants of universal applicability determining the architecture of soluble proteins.

  6. Assessing Students' Conceptual Understanding of Solubility Equilibrium.

    ERIC Educational Resources Information Center

    Raviolo, Andres

    2001-01-01

    Presents a problem on solubility equilibrium which involves macroscopic, microscopic, and symbolic levels of representation as a resource for the evaluation of students, and allows for assessment as to whether students have acquired an adequate conceptual understanding of the phenomenon. Also diagnoses difficulties with regard to previous…

  7. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, B.F.; Robison, T.W.; Gohdes, J.W.

    1999-04-06

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polyvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  8. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, Barbara F.; Robison, Thomas W.; Gohdes, Joel W.

    2002-01-01

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  9. Water-soluble polymers and compositions thereof

    DOEpatents

    Smith, Barbara F.; Robison, Thomas W.; Gohdes, Joel W.

    1999-01-01

    Water-soluble polymers including functionalization from the group of amino groups, carboxylic acid groups, phosphonic acid groups, phosphonic ester groups, acylpyrazolone groups, hydroxamic acid groups, aza crown ether groups, oxy crown ethers groups, guanidinium groups, amide groups, ester groups, aminodicarboxylic groups, permethylated polyvinylpyridine groups, permethylated amine groups, mercaptosuccinic acid groups, alkyl thiol groups, and N-alkylthiourea groups are disclosed.

  10. Surface shear inviscidity of soluble surfactants

    PubMed Central

    Zell, Zachary A.; Nowbahar, Arash; Mansard, Vincent; Leal, L. Gary; Deshmukh, Suraj S.; Mecca, Jodi M.; Tucker, Christopher J.; Squires, Todd M.

    2014-01-01

    Foam and emulsion stability has long been believed to correlate with the surface shear viscosity of the surfactant used to stabilize them. Many subtleties arise in interpreting surface shear viscosity measurements, however, and correlations do not necessarily indicate causation. Using a sensitive technique designed to excite purely surface shear deformations, we make the most sensitive and precise measurements to date of the surface shear viscosity of a variety of soluble surfactants, focusing on SDS in particular. Our measurements reveal the surface shear viscosity of SDS to be below the sensitivity limit of our technique, giving an upper bound of order 0.01 μN·s/m. This conflicts directly with almost all previous studies, which reported values up to 103–104 times higher. Multiple control and complementary measurements confirm this result, including direct visualization of monolayer deformation, for SDS and a wide variety of soluble polymeric, ionic, and nonionic surfactants of high- and low-foaming character. No soluble, small-molecule surfactant was found to have a measurable surface shear viscosity, which seriously undermines most support for any correlation between foam stability and surface shear rheology of soluble surfactants. PMID:24563383

  11. A new expanded solubility parameter approach.

    PubMed

    Stefanis, Emmanuel; Panayiotou, Costas

    2012-04-15

    The partial or Hansen solubility parameters (HSP) are important properties of the various substances and very useful tools for the selection of their solvents or the prediction of their behaviour in numerous applications. Their design and evaluation relies on the basic rule of "similarity matching" for solubility. The present work attempts to enhance the capacity of HSPs by incorporating into their evaluation the other basic rule of solubility, namely, the rule of "complementarity matching". This is done in a simple and straightforward manner by splitting the hydrogen bonding HSP into its acidic or proton donor component and its basic or proton acceptor one. The splitting is based on the third σ-moments of the screening charge distributions or sigma profiles of the quantum-mechanics based COSMO-RS theory. The whole development and application does not involve any sophisticated calculations or any strong specific background. The new method has been applied to a variety of solubility data for systems of pharmaceutical interest in order to verify the significant improvement over the classical HSP approach. The application of the new method requires, of course, the knowledge of the HSPs. For this reason, in Appendix A is presented an updated version of a robust and reliable group-contribution method for the calculation of the HSPs. The key features of this combined tool are critically discussed.

  12. Determination of water-soluble and fat-soluble vitamins in tears and blood serum of infants and parents by liquid chromatography/mass spectrometry.

    PubMed

    Khaksari, Maryam; Mazzoleni, Lynn R; Ruan, Chunhai; Kennedy, Robert T; Minerick, Adrienne R

    2016-12-23

    Tears serve as a viable diagnostic fluid with advantages including less invasive sample to collect and less complex to prepare for analysis. Several water-soluble and fat-soluble vitamins were detected and quantified in human tears and compared with blood serum levels. Samples from 15 family pairs, each pair consisting of a four-month-old infant and one parent were analyzed; vitamin concentrations were compared between tears and blood serum for individual subjects, between infants and parents, and against self-reported dietary intakes. Water-soluble vitamins B1, B2, B3 (nicotinamide), B5, B9 and fat-soluble vitamin E (α-tocopherol) were routinely detected in tears and blood serum while fat-soluble vitamin A (retinol) was detected only in blood serum. Water-soluble vitamin concentrations measured in tears and blood serum of single subjects were comparable, while higher concentrations were measured in infants compared to their parents. Fat-soluble vitamin E concentrations were lower in tears than blood serum with no significant difference between infants and parents. Serum vitamin A concentrations were higher in parents than infants. Population trends were compiled and quantified using a cross correlation factor. Strong positive correlations were found between tear and blood serum concentrations of vitamin E from infants and parents and vitamin B3 concentrations from parents, while slight positive correlations were detected for infants B3 and parents B1 and B2 concentrations. Correlations between infants and parents were found for the concentrations of B1, B2, B3, and E in tears, and the concentrations of B2, A, and E in blood serum. Stronger vitamin concentration correlations were found between infants and parents for the breast-fed infants, while no significant difference was observed between breast-fed and bottle-fed infants. This work is the first to demonstrate simultaneous vitamin A, B, and E detection and to quantify correlations between vitamin

  13. Solubility enhancement of BCS Class II drug by solid phospholipid dispersions: Spray drying versus freeze-drying.

    PubMed

    Fong, Sophia Yui Kau; Ibisogly, Asiye; Bauer-Brandl, Annette

    2015-12-30

    The poor aqueous solubility of BCS Class II drugs represents a major challenge for oral dosage form development. Using celecoxib (CXB) as model drug, the current study adopted a novel solid phospholipid nanoparticle (SPLN) approach and compared the effect of two commonly used industrial manufacturing methods, spray- and freeze-drying, on the solubility and dissolution enhancement of CXB. CXB was formulated with Phospholipoid E80 (PL) and trehalose at different CXB:PL:trehalose ratios, of which 1:10:16 was the optimal formulation. Spherical amorphous SPLNs with average diameters <1μm were produced by spray-drying; while amorphous 'matrix'-like structures of solid PL dispersion with larger particle sizes were prepared by freeze-drying. Formulations from both methods significantly enhanced the dissolution rates, apparent solubility, and molecularly dissolved concentration of CXB in phosphate buffer (PBS, pH 6.5) and in biorelevant fasted state simulated intestinal fluid (FaSSIF, pH 6.5) (p<0.05). While similar dissolution rates were found, the spray-dried SPLNs had a larger enhancement in apparent solubility (29- to 132-fold) as well as molecular solubility (18-fold) of CXB at equilibrium (p<0.05). The strong capability of the spray-dried SPLNs to attain 'true' supersaturation state makes them a promising approach for bioavailability enhancement of poorly soluble drugs.

  14. Basic fluid system trainer

    DOEpatents

    Semans, Joseph P.; Johnson, Peter G.; LeBoeuf, Jr., Robert F.; Kromka, Joseph A.; Goron, Ronald H.; Hay, George D.

    1993-01-01

    A trainer, mounted and housed within a mobile console, is used to teach and reinforce fluid principles to students. The system trainer has two centrifugal pumps, each driven by a corresponding two-speed electric motor. The motors are controlled by motor controllers for operating the pumps to circulate the fluid stored within a supply tank through a closed system. The pumps may be connected in series or in parallel. A number of valves are also included within the system to effect different flow paths for the fluid. In addition, temperature and pressure sensing instruments are installed throughout the closed system for measuring the characteristics of the fluid, as it passes through the different valves and pumps. These measurements are indicated on a front panel mounted to the console, as a teaching aid, to allow the students to observe the characteristics of the system.

  15. Lighter fluid poisoning

    MedlinePlus

    ... in lighter fluids are called hydrocarbons. They include: Benzene Butane Hexamine Lacolene Naptha Propane Where Found Various ... PA: Elsevier Saunders; 2014:chap 158. Mirkin DB. Benzene and related aromatic hydrocarbons. In: Shannon MW, Borron ...

  16. Polymer Fluid Dynamics.

    ERIC Educational Resources Information Center

    Bird, R. Byron

    1980-01-01

    Problems in polymer fluid dynamics are described, including development of constitutive equations, rheometry, kinetic theory, flow visualization, heat transfer studies, flows with phase change, two-phase flow, polymer unit operations, and drag reduction. (JN)

  17. Pericardial fluid Gram stain

    MedlinePlus

    ... a bacterial infection. The Gram stain method is one of the most commonly used techniques for the rapid diagnosis of bacterial infections. How the Test is Performed A sample of fluid will be taken from the sac ...

  18. Improved perfluoroalkylether fluid development

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.; Paciorek, K.; Nakahara, J.; Smythe, M.; Kratzer, R.

    1986-01-01

    The feasibility of transforming a commercial linear perfluoroalkylether fluid into a material stable in the presence of metals and metal alloys in oxidizing atmospheres at 300 C without the loss of the desirable viscosity temperature characteristics was determined. The approach consisted of thermal oxidative treatment in the presence of catalyst to remove weak links, followed by transformation of the created functional groups into phospha-s-triazine linkages. It it found that the experimental material obtained in 66% yield from the commercial fluid exhibits, over an 8 hr period at 300 C in the presence of Ti(4Al, 4Mn) alloy, thermal oxidative stability better by a factor of 2.6x1000 based on volatiles evolved than the commercial product. The viscosity and molecular weight of the developed fluid are unchanged and are essentially identical with the commercial material. No metal corrosion occurs with the experimental fluid at 300 C.

  19. Culture - joint fluid

    MedlinePlus

    Joint fluid culture ... fungi, or viruses grow. This is called a culture. If these germs are detected, other tests may ... is no special preparation needed for the lab culture. How to prepare for the removal of joint ...

  20. Our World: Fluid Shift

    NASA Video Gallery

    Learn about the circulatory system and how gravity aids blood flow in our bodies here on Earth. Find out how NASA flight surgeons help the astronauts deal with the fluid shift that happens during s...

  1. Cerebrospinal fluid culture

    MedlinePlus

    ... Alternative Names Culture - CSF; Spinal fluid culture; CSF ... In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods . 23d ed. Philadelphia, PA: Elsevier; ...

  2. Windshield washer fluid

    MedlinePlus

    ... support, including oxygen, breathing tube through the mouth (intubation), and breathing machine (ventilator) Blood and urine tests ... Methanol, the main ingredient in windshield washing fluid, is extremely ... As little as 2 tablespoons (30 milliliters) can be deadly ...

  3. Pericardial Fluid Analysis

    MedlinePlus

    ... this test may be used to help detect tuberculosis (TB) . Less commonly ordered tests for infectious diseases, ... fluid in a person with symptoms that suggest tuberculosis means it is likely that person has a ...

  4. Fluid pumping apparatus

    DOEpatents

    West, Phillip B.

    2006-01-17

    A method and apparatus suitable for coupling seismic or other downhole sensors to a borehole wall in high temperature and pressure environments. In one embodiment, one or more metal bellows mounted to a sensor module are inflated to clamp the sensor module within the borehole and couple an associated seismic sensor to a borehole wall. Once the sensing operation is complete, the bellows are deflated and the sensor module is unclamped by deflation of the metal bellows. In a further embodiment, a magnetic drive pump in a pump module is used to supply fluid pressure for inflating the metal bellows using borehole fluid or fluid from a reservoir. The pump includes a magnetic drive motor configured with a rotor assembly to be exposed to borehole fluid pressure including a rotatable armature for driving an impeller and an associated coil under control of electronics isolated from borehole pressure.

  5. Fluid management system technology discipline

    NASA Technical Reports Server (NTRS)

    Symons, E. Patrick

    1990-01-01

    Viewgraphs on fluid management system technology discipline for Space Station Freedom are presented. Topics covered include: subcritical cryogenic storage and transfer; fluid handling; and components and instrumentation.

  6. Production and Characterization of Monoclonal Antibodies to Soluble Rat Lung Guanylate Cyclase

    NASA Astrophysics Data System (ADS)

    Brandwein, Harvey; Lewicki, John; Murad, Ferid

    1981-07-01

    Four monoclonal antibodies to rat lung soluble guanylate cyclase [GTP pyrophosphate-lyase (cyclizing) EC 4.6.1.2] have been produced by fusing spleen cells from immunized BALB/c mice with SP-2/0 myeloma cells. The antibodies were detected by their ability to bind immobilized guanylate cyclase and by immunoprecipitation of purified enzyme in the presence of second (rabbit anti-mouse) antibody. After subcloning by limiting dilution, hybridomas were injected intraperitoneally into mice to produce ascitic fluid containing 2-5 mg of antibody per ml. The four antibodies obtained had titers of between 1:1580 and 1:3160 but were detectable at dilutions greater than 1:20,000. Soluble guanylate cyclase from several rat tissues were crossreactive with the four monoclonal antibodies, suggesting that the soluble enzyme from different rat tissues is antigenically similar. The antibodies also recognized soluble lung enzyme from rat, beef, and pig, while enzyme from rabbit was not crossreactive and mouse enzyme was recognized by only one of the antibodies. Particulate guanylate cyclase from a number of tissues had only minimal crossreactivity with the antibodies. Immunoprecipitated guanylate cyclase retained catalytic activity, could be activated with sodium nitroprusside, and was inhibited by cystamine. None of the antibodies were inhibitory under the conditions examined. These antibodies will be useful probes for the study of guanylate cyclase regulation and function under a variety of physiological conditions.

  7. Influence of chemical and mechanical polishing on water sorption and solubility of denture base acrylic resins.

    PubMed

    Rahal, Juliana Saab; Mesquita, Marcelo Ferraz; Henriques, Guilherme Elias Pessanha; Nóbilo, Mauro Antonio Arruda

    2004-01-01

    Influence of polishing methods on water sorption and solubility of denture base acrylic resins was studied. Eighty samples were divided into groups: Classico (CL), and QC 20 (QC) - hot water bath cured; Acron MC (AC), and Onda Cryl (ON) - microwave cured; and submitted to mechanical polishing (MP) - pumice slurry, chalk powder, soft brush and felt cone in a bench vise; or chemical polishing (CP) - heated monomer fluid in a chemical polisher. The first desiccation process was followed by storage in distilled water at 37 +/- 1 degrees C for 1 h, 1 day, 1, 2, 3 and 4 weeks. Concluding each period, water sorption was measured. After the fourth week, a second desiccation process was done to calculate solubility. Data were submitted to analysis of variance, followed by Tukey test (psolubility (%), respectively, were: CL-MP: 1.92 and 0.02; CL-CP: 1.98 and 0.52; QC-MP: 2.31 and -0.05; QC-CP: 2.32 and 0.25; AC-MP: 2.45 and -0.07; AC-CP: 2.43 and 0.41; ON-MP: 2.32 and -0.06; ON-CP: 2.34 and 0.27. Mechanical polishing promoted significantly lower solubility of acrylic resins; initially, water sorption values were higher for chemically polished samples, however, after 4 weeks all groups were similar.

  8. [Diagnosis: synovial fluid analysis].

    PubMed

    Gallo Vallejo, Francisco Javier; Giner Ruiz, Vicente

    2014-01-01

    Synovial fluid analysis in rheumatological diseases allows a more accurate diagnosis in some entities, mainly infectious and microcrystalline arthritis. Examination of synovial fluid in patients with osteoarthritis is useful if a differential diagnosis will be performed with other processes and to distinguish between inflammatory and non-inflammatory forms. Joint aspiration is a diagnostic and sometimes therapeutic procedure that is available to primary care physicians.

  9. Fluid infusion system

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Performance testing carried out in the development of the prototype zero-g fluid infusion system is described and summarized. Engineering tests were performed in the course of development, both on the original breadboard device and on the prototype system. This testing was aimed at establishing baseline system performance parameters and facilitating improvements. Acceptance testing was then performed on the prototype system to verify functional performance. Acceptance testing included a demonstration of the fluid infusion system on a laboratory animal.

  10. Fluid therapy in shock.

    PubMed

    Mandell, D C; King, L G

    1998-05-01

    The goal of treatment for all types of shock is the improvement of tissue perfusion and oxygenation. The mainstay of therapy for hypovolemic and septic shock is the expansion of the intravascular volume by fluid administration, including crystalloids, colloids, and blood products. Frequent physical examinations and monitoring enable the clinician to determine the adequacy of tissue oxygenation and thus the success of the fluid therapy.

  11. Drilling fluid disposal

    SciTech Connect

    Nesbitt, L.E.; Sander, J.A.

    1981-01-01

    This paper attempts to review the effect of the regulatory process on the selection and handling of drilling fluids for proper disposal. It is shown that a maze of regulations and regulatory agencies coupled with uncertainty in interpretation of environmental data and an evolving system of disposal engineering will require industry action to monitor the area and derive a solid engineering basis for disposal of spent drilling fluid. 16 refs.

  12. Volatile Solubilities in Mt. Somma-Vesuvius Phonolite Melt and New Insights on Degassing of Sulfur, Chlorine, and Water

    NASA Astrophysics Data System (ADS)

    Webster, J. D.; Sintoni, M. F.; de Vivo, B.; Lima, A.

    2007-05-01

    To better understand volatile exsolution, degassing, and eruptive processes in subduction-related magmas, we have conducted thirty H2O plus S plus Cl solubility experiments with phonolite melt at 905 to 1000 deg. C, 200 MPa, and relatively oxidizing conditions. The experiments include an 8000-year old Mt. Somma-Vesuvius phonolite, distilled H2O, NaCl, KCl, and CaSO4, and they involve a new method of constraining the concentration of S in the run-product fluids. Unlike prior S-solubility experiments, the S concentration in fluid is determined as proportional to the mass loss of the anhydrite crystals in the starting charges of the experiments. This method provides accurate S contents of fluids. The H2O, Cl, and S concentrations of the phonolitic glasses of our experiments range from 4 to 8, 0.38 to 0.84, and 0.01 to 0.19 wt.%, respectively. Sulfur solubility increases with increasing CaO and FeO (total iron) in melt, decreasing Cl and K2O in melt, decreasing Cl in fluid(s), and with increasing oxygen fugacity values greater than NNO. Chlorine solubility in melt increases with decreasing S content of melt and decreasing S and H2O in the coexisting fluid(s). Water solubility in melt shows no systematic variation with melt composition, but varies strongly with the composition of fluids. The partition coefficients (wt.% of X in fluid[s]/wt.% of X in phonolitic melt) range from 40 to > 200 for S and from 12 to 87 for Cl. At pressure-temperature-oxygen fugacity conditions similar to those of this study, these partition coefficients are equivalent to those determined previously for natural equilibria involving andesite melt plus Cl-free, S-bearing aqueous fluid (Scaillet and Pichavant, 2003) and experimental equilibria with andesite melt plus S-free, Cl-bearing aqueous fluid (Webster et al., 1999), respectively. Our research also shows that these partition coefficients for S and Cl are inversely proportional to one another. Silicate melt inclusions in pyroxene phenocrysts

  13. Transdermal Delivery of Iron Using Soluble Microneedles: Dermal Kinetics and Safety.

    PubMed

    Modepalli, Naresh; Shivakumar, H Nanjappa; McCrudden, Maeliosa T C; Donnelly, Ryan F; Banga, Ajay; Murthy, S Narasimha

    2016-03-01

    Currently, the iron compounds are administered via oral and parenteral routes in patients of all ages, to treat iron deficiency. Despite continued efforts to supplement iron via these conventional routes, iron deficiency still remains the most prevalent nutritional disorder all over the world. Transdermal replenishment of iron is a novel, potential approach of iron replenishment. Ferric pyrophosphate (FPP) was found to be a suitable source of iron for transdermal replenishment. The safety of FPP was assessed in this project by challenging the dermal fibroblast cells with high concentration of FPP. The cell viability assay and reactive oxygen species assay were performed. The soluble microneedle array was developed, incorporated with FPP and the kinetics of free iron in the skin; extracellular fluid following dermal administration of microneedle array was investigated in hairless rats. From the cell based assays, FPP was selected as one of the potential iron sources for transdermal delivery. The microneedles were found to dissolve in the skin fluid within 3 hours of administration. The FPP concentration in the dermal extracellular fluid declined after complete dissolution of the microneedle array. Overall, the studies demonstrated the safety of FPP for dermal delivery and the feasibility of soluble microneedle approach for transdermal iron replenishment therapy.

  14. Thermodynamically Consistent Fluid Mixing in Porous Media Induced by Viscous Fingering and Channeling of Multiphase Flow

    NASA Astrophysics Data System (ADS)

    Amooie, Mohammad Amin; Soltanian, Mohammad Reza; Moortgat, Joachim

    2016-11-01

    Fluid mixing and its interplay with viscous fingering as well as flow channeling through heterogeneous media have been traditionally studied for fully (im)miscible conditions in which a (two-) single-phase system is represented by two components, e.g. a solvent and a solute, with (zero) infinite mutual solubility. However, many subsurface problems, e.g. gas injection/migration in hydrocarbon reservoirs, involve multiple species transfer. Multicomponent fluid properties behave non-linearly, through an equation of state, as a function of temperature, pressure, and compositions. Depending on the minimum miscibility pressure, a two-phase region with finite, non-zero mutual solubility may develop, e.g. in a partially-miscible system. Here we study mixing of fluids with partial mutual solubility, induced by viscous flow fingering, channeling, and species transport within and between phases. We uncover non-linear mixing dynamics of a finite-size slug of a less viscous fluid attenuated by a carrier fluid during rectilinear displacement. We perform accurate numerical simulations that are thermodynamically-consistent to capture fingering patterns and complex phase behavior of mixtures. The results provide a broad perspective into how multiphase flow can alter fluid mixing in porous media.

  15. State of the art of nanocrystals technology for delivery of poorly soluble drugs

    NASA Astrophysics Data System (ADS)

    Zhou, Yuqi; Du, Juan; Wang, Lulu; Wang, Yancai

    2016-09-01

    Formulation of nanocrystals is a distinctive approach which can effectively improve the delivery of poorly water-soluble drugs, thus enticing the development of the nanocrystals technology. The characteristics of nanocrystals resulted in an exceptional drug delivery conductance, including saturation solubility, dissolution velocity, adhesiveness, and affinity. Nanocrystals were treated as versatile pharmaceuticals that could be delivered through almost all routes of administration. In the current review, oral, pulmonary, and intravenous routes of administration were presented. Also, the targeting of drug nanocrystals, as well as issues of efficacy and safety, were also discussed. Several methods were applied for nanocrystals production including top-down production strategy (media milling, high-pressure homogenization), bottom-up production strategy (antisolvent precipitation, supercritical fluid process, and precipitation by removal of solvent), and the combination approaches. Moreover, this review also described the evaluation and characterization of the drug nanocrystals and summarized the current commercial pharmaceutical products utilizing nanocrystals technology.

  16. Levels of soluble E-cadherin in breast, gastric, and colorectal cancers.

    PubMed

    Repetto, Ombretta; De Paoli, Paolo; De Re, Valli; Canzonieri, Vincenzo; Cannizzaro, Renato

    2014-01-01

    Soluble E-cadherin is a 80 kDa protein fragment coming from the proteolytic cleavage of the extracellular domain of the full length epithelial cadherin, a molecule involved in cell adhesion/polarity and tissue morphogenesis. In comparison with normal epithelia, cancer cells show a decreased cadherin-mediated intercellular adhesion, and sE-cad levels normally increase in body fluids (blood and urine). This review focuses on soluble E-cadherin in sera of patients affected by three solid cancers (breast, gastric, and colorectal cancers) and how its levels correlate or not with some cancer parameters (e.g., dimension, progression, and localisation). We will describe the main proteomics approaches adopted to measure sE-cad both in vivo and in vitro and the most important findings about its behaviour in cancer dynamics.

  17. Solubility of NaCl in aqueous electrolyte solutions from 10 to 100°C

    USGS Publications Warehouse

    Clynne, M.A.; Potter, R.W.; Haas, J.L.

    1981-01-01

    The solubilities of NaCl in aqueous KCl, MgCl2, CaCl2, and mixed CaCl2-KCl solutions have been determined from 10 to 100??C. The data were fit to an equation, and the equation was used to calculate values of the change in solubility of NaCl, ???[NaCl]/???T. These values are required for calculations of the rate of migration of fluids in a thermal gradient in rock salt. The data obtained here indicate that the values of ???[NaCl]/???T are 36-73% greater for solutions containing divalent ions than for the NaCl-H2O system.

  18. Method for removing impurities from an impurity-containing fluid stream

    DOEpatents

    Ginosar, Daniel M.; Fox, Robert V.

    2010-04-06

    A method of removing at least one polar component from a fluid stream. The method comprises providing a fluid stream comprising at least one nonpolar component and at least one polar component. The fluid stream is contacted with a supercritical solvent to remove the at least one polar component. The at least one nonpolar component may be a fat or oil and the at least one polar component may be water, dirt, detergents, or mixtures thereof. The supercritical solvent may decrease solubility of the at least one polar component in the fluid stream. The supercritical solvent may function as a solvent or as a gas antisolvent. The supercritical solvent may dissolve the nonpolar components of the fluid stream, such as fats or oils, while the polar components may be substantially insoluble. Alternatively, the supercritical solvent may be used to increase the nonpolarity of the fluid stream.

  19. Solubility Enhancement of a Poorly Water Soluble Drug by Forming Solid Dispersions using Mechanochemical Activation

    PubMed Central

    Rojas-Oviedo, I.; Retchkiman-Corona, B.; Quirino-Barreda, C. T.; Cárdenas, J.; Schabes-Retchkiman, P. S.

    2012-01-01

    Mechanochemical activation is a practical cogrinding operation used to obtain a solid dispersion of a poorly water soluble drug through changes in the solid state molecular aggregation of drug-carrier mixtures and the formation of noncovalent interactions (hydrogen bonds) between two crystalline solids such as a soluble carrier, lactose, and a poorly soluble drug, indomethacin, in order to improve its solubility and dissolution rate. Samples of indomethacin and a physical mixture with a weight ratio of 1:1 of indomethacin and lactose were ground using a high speed vibrating ball mill. Particle size was determined by electron microscopy, the reduction of crystallinity was determined by calorimetry and transmission electron microscopy, infrared spectroscopy was used to find evidence of any interactions between the drug and the carrier and the determination of apparent solubility allowed for the corroboration of changes in solubility. Before grinding, scanning electron microscopy showed the drug and lactose to have an average particle size of around 50 and 30 μm, respectively. After high speed grinding, indomethacin and the mixture had a reduced average particle size of around 5 and 2 μm, respectively, showing a morphological change. The ground mixture produced a solid dispersion that had a loss of crystallinity that reached 81% after 30 min of grinding while the drug solubility of indomethacin within the solid dispersion increased by 2.76 fold as compared to the pure drug. Drug activation due to hydrogen bonds between the carboxylic group of the drug and the hydroxyl group of lactose as well as the decrease in crystallinity of the solid dispersion and the reduction of the particle size led to a better water solubility of indomethacin. PMID:23798775

  20. Novel electrosprayed nanospherules for enhanced aqueous solubility and oral bioavailability of poorly water-soluble fenofibrate

    PubMed Central

    Yousaf, Abid Mehmood; Mustapha, Omer; Kim, Dong Wuk; Kim, Dong Shik; Kim, Kyeong Soo; Jin, Sung Giu; Yong, Chul Soon; Youn, Yu Seok; Oh, Yu-Kyoung; Kim, Jong Oh; Choi, Han-Gon

    2016-01-01

    Purpose The purpose of the present research was to develop a novel electrosprayed nanospherule providing the most optimized aqueous solubility and oral bioavailability for poorly water-soluble fenofibrate. Methods Numerous fenofibrate-loaded electrosprayed nanospherules were prepared with polyvinylpyrrolidone (PVP) and Labrafil® M 2125 as carriers using the electrospray technique, and the effect of the carriers on drug solubility and solvation was assessed. The solid state characterization of an optimized formulation was conducted by scanning electron microscopy, powder X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopic analyses. Oral bioavailability in rats was also evaluated for the formulation of an optimized nanospherule in comparison with free drug and a conventional fenofibrate-loaded solid dispersion. Results All of the electrosprayed nanospherule formulations had remarkably enhanced aqueous solubility and dissolution compared with free drug. Moreover, Labrafil M 2125, a surfactant, had a positive influence on the solubility and dissolution of the drug in the electrosprayed nanospherule. Increases were observed as the PVP/drug ratio increased to 4:1, but higher ratios gave no significant increases. In particular, an electrosprayed nanospherule composed of fenofibrate, PVP, and Labrafil M 2125 at the weight ratio of 1:4:0.5 resulted in a particle size of <200 nm with the drug present in the amorphous state. It demonstrated the highest solubility (32.51±2.41 μg/mL), an excellent dissolution (~85% in 10 minutes), and an oral bioavailability ~2.5-fold better than that of the free drug. It showed similar oral bioavailability compared to the conventional solid dispersion. Conclusion Electrosprayed nanospherules, which provide improved solubility and bioavailability, are promising drug delivery tools for oral administration of poorly water-soluble fenofibrate. PMID:26834471

  1. [Fluid management: estimation of fluid status].

    PubMed

    Renner, Jochen; Broch, Ole; Bein, Berthold

    2012-07-01

    Cardiac filling pressures alone are not appropriate to estimate the effect of a volume challenge on the corresponding change in stroke volume. Dynamic variables of fluid responsiveness have been shown to discriminate with acceptable sensitivity and specificity between responders and non-responders to a volume challenge. However, several clinical confounders have been indentified which potentially influence the predictive power of these variables. Sound knowledge of these confounders and the acknowledgement that there is no unique threshold value for volume optimisation but a considerable "gray zone" is necessary to fully exploit the advantages of functional haemodynamic monitoring.

  2. Preparation of drug delivery systems using supercritical fluid technology.

    PubMed

    Kompella, U B; Koushik, K

    2001-01-01

    Small changes in temperature and pressure near the critical region induce dramatic changes in the density and solubility of supercritical fluids, thereby facilitating the use of environmentally benign agents such as CO2 for their solvent and antisolvent properties in processing a wide variety of materials. While supercritical fluid technologies have been in commercial use in the food and chromatography industries for several years, only recently has this technology made inroads in the formulation of drug delivery systems. This review summarizes some of the recent applications of supercritical fluid technology in the preparation of drug delivery systems. Drugs containing polymeric particles, plain drug particles, solute-containing liposomes, and inclusion complexes of drug and carrier have been formulated using this technology. Also, polymer separation using this technology is enabling the selection of a pure fraction of a polymer, thereby allowing a more precise control of drug release from polymeric delivery systems.

  3. Blood-Mimicking Fluid for Testing Ultrasonic Diagnostic Instrument

    NASA Astrophysics Data System (ADS)

    Tanaka, Kouhei; Yoshida, Tomoji; Sato, Kazuishi; Kondo, Toshio; Yasukawa, Kazuhiro; Miyamoto, Nobuaki; Taniguchi, Masahiko

    2012-07-01

    We present a blood-mimicking fluid (BMF) for the Doppler test object of medical diagnostic instruments. Accurate measurement in a flow Doppler test requires a BMF that has the acoustic velocity and density defined in the International Electrotechnical Commission (IEC) standard, and furthermore, they must be stable over time. To formulate a fluid with the desired density and acoustic velocity, we have developed a new fluid made of glycerine and water-soluble silicone oil. The new BMF includes dispersed polystyrene particles as scatterers. The density of the liquid can be adjusted to maintain it at the same value as that of the polystyrene particles, thus ensuring neutral buoyancy of the particles. The MBF was stable over a period of 2 weeks, during which the density and acoustic velocity did not change.

  4. Fluid extraction using carbon dioxide and organophosphorus chelating agents

    DOEpatents

    Smart, Neil G.; Wai, Chien M.; Lin, Yuehe; Kwang, Yak Hwa

    1998-01-01

    Methods for extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical CO.sub.2, and a chelating agent are described. The chelating agent forms a chelate with the species, the chelate being soluble in the fluid to allow removal of the species from the material. In preferred embodiments the extraction solvent is supercritical CO.sub.2 and the chelating agent comprises an organophosphorous chelating agent, particularly sulfur-containing organophosphorous chelating agents, including mixtures of chelating agents. Examples of chelating agents include monothiophosphinic acid, di-thiophosphinic acid, phosphine sulfite, phosphorothioic acid, and mixtures thereof. The method provides an environmentally benign process for removing metal and metalloids from industrial waste solutions, particularly acidic solutions. Both the chelate and the supercritical fluid can be regenerated and the contaminant species recovered to provide an economic, efficient process.

  5. Fluid extraction using carbon dioxide and organophosphorus chelating agents

    DOEpatents

    Smart, N.G.; Wai, C.M.; Lin, Y.; Kwang, Y.H.

    1998-11-24

    Methods for extracting metalloid and metal species from a solid or liquid material by exposing the material to a fluid solvent, particularly supercritical CO{sub 2}, and a chelating agent are described. The chelating agent forms a chelate with the species, the chelate being soluble in the fluid to allow removal of the species from the material. In preferred embodiments the extraction solvent is supercritical CO{sub 2} and the chelating agent comprises an organophosphorous chelating agent, particularly sulfur-containing organophosphorous chelating agents, including mixtures of chelating agents. Examples of chelating agents include monothiophosphinic acid, di-thiophosphinic acid, phosphine sulfite, phosphorothioic acid, and mixtures thereof. The method provides an environmentally benign process for removing metal and metalloids from industrial waste solutions, particularly acidic solutions. Both the chelate and the supercritical fluid can be regenerated and the contaminant species recovered to provide an economic, efficient process. 1 fig.

  6. Fluid loss control differences of crosslinked and linear fracturing fluids

    SciTech Connect

    Zigrye, J.L.; Whitfill, D.L.; Sievert, J.A.

    1983-01-01

    Three fracturing fluids--a crosslinked guar, a delayed hydrating guar, and a linear guar--were tested for fluid loss control at set time intervals while being conditioned in a heated, pressurized flow loop. Each fluid was tested with 3 different fluid loss additive systems: diesel, silica flour, and a combination of diesel and silica flour. The crosslinked system was tested also with 2 additional fluid loss additive systems. These fluids were diesel plus an anionic surfactant and the combination of diesel/silica flour plus the anionic surfactant. These tests show that the fluid loss of crosslinked fracturing fluids is best controlled by using diesel in combination with a surfactant or a properly sized particulate material. The fluid loss of linear fluids is controlled best with particulate additives.

  7. Valence effects on solubility and sorption: the solubility of Tc(IV) oxides

    SciTech Connect

    Meyer, R.E.; Arnold, W.D.; Case, F.I.

    1986-03-01

    The solubilities of technetium (IV) oxides have been determined in solutions of NaCl, HCl, and synthetic groundwaters in the pH range 0 to 10. Oxides were prepared either by electroreduction from Tc(VII) solutions onto platinum electrodes or by precipitation of Tc from Tc(VII) solutions using hydrazine. In some of the determinations, the oxide was precipitated onto purified sand by use of hydrazine. The oxide-covered sand was then placed into a column and the test solution continuously recirculated through the column. The oxide plated on platinum was placed into a small cell and the test solution stirred. Solubilities were determined by measuring the beta radiation of /sup 99/Tc in the stirred or circulated solution in contact with the oxide. In the pH range 4 to 10, solubilities were in the range 7.5 x 10/sup -9/ to 5 x 10/sup -8/ mol/L, and most of the determinations were in the range 1 x 10/sup -8/ to 2 x 10/sup -8/ mol/L. In acid solutions the solubilities were generally higher for hydrazine-precipitated oxide than for the electrodeposited oxide, and they increased as the pH was lowered. Solubilities of Tc(IV) oxides will be useful for calculation of transport rates of technetium for the case of solubility-limited transport in nuclear waste repository environments.

  8. Water solubility in pyrope at high pressures

    NASA Astrophysics Data System (ADS)

    Mookherjee, M.; Karato, S.-

    2006-12-01

    To address how much water is stored within the Earth's mantle, we need to understand the water solubility in the nominally anhydrous minerals. Much is known about olivine and pyroxene. Garnet is another important component, approaching 40% by volume in the transition zone. Only two studies on water solubility in pyrope at high-pressures exist which contradict each other. Lu and Keppler (1997) observed increase in water solubility in a natural pyrope up to 200 ppm wt of water, till 10 GPa. They concluded that the proton is located in the interstitial site. Withers et al. (1998) on the contrary, observed increasing water content in Mg-rich pyrope till 6 GPa, then sudden decrease of water, beyond detection, at 7 GPa. Based on infrared spectra, Withers et al. (1998), concluded hydrogarnet (Si^{4+} replaced by 4H+ to form O4H4) substitution in synthetic magnesium rich pyrope. They argued that at high pressure owing to larger volume, hydrogarnet substitution is unstable and water is expelled out of garnet. In transition zone conditions, however, majorite garnet seems to contain around 600-700 ppm wt of water (Bolfan-Casanova et al. 2000; Katayama et al. 2003). The cause for such discrepancy is not clear and whether garnet could store a significant amount of water at mantle condition is unconstrained. In order to understand the solubility mechanism of water in pyrope at high-pressure, we have conducted high- pressure experiments on naturally occurring single crystals of pyrope garnet (from Arizona, Aines and Rossman, 1984). To ascertain water-saturated conditions, we use olivine single-crystal as an internal standard. Preliminary results indicate that natural pyrope is capable of dissolving water at high-pressures, however, water preferentially enters olivine than in pyrope. We are undertaking systematic study to estimate the solubility of water in pyrope as a function of pressure. This will enable us to develop solubility models to understand the defect mechanisms

  9. Intravenous Fluid Generation System

    NASA Technical Reports Server (NTRS)

    McQuillen, John; McKay, Terri; Brown, Daniel; Zoldak, John

    2013-01-01

    The ability to stabilize and treat patients on exploration missions will depend on access to needed consumables. Intravenous (IV) fluids have been identified as required consumables. A review of the Space Medicine Exploration Medical Condition List (SMEMCL) lists over 400 medical conditions that could present and require treatment during ISS missions. The Intravenous Fluid Generation System (IVGEN) technology provides the scalable capability to generate IV fluids from indigenous water supplies. It meets USP (U.S. Pharmacopeia) standards. This capability was performed using potable water from the ISS; water from more extreme environments would need preconditioning. The key advantage is the ability to filter mass and volume, providing the equivalent amount of IV fluid: this is critical for remote operations or resource- poor environments. The IVGEN technology purifies drinking water, mixes it with salt, and transfers it to a suitable bag to deliver a sterile normal saline solution. Operational constraints such as mass limitations and lack of refrigeration may limit the type and volume of such fluids that can be carried onboard the spacecraft. In addition, most medical fluids have a shelf life that is shorter than some mission durations. Consequently, the objective of the IVGEN experiment was to develop, design, and validate the necessary methodology to purify spacecraft potable water into a normal saline solution, thus reducing the amount of IV fluids that are included in the launch manifest. As currently conceived, an IVGEN system for a space exploration mission would consist of an accumulator, a purifier, a mixing assembly, a salt bag, and a sterile bag. The accumulator is used to transfer a measured amount of drinking water from the spacecraft to the purifier. The purifier uses filters to separate any air bubbles that may have gotten trapped during the drinking water transfer from flowing through a high-quality deionizing cartridge that removes the impurities in

  10. Improved perfluoroalkylether fluid development

    NASA Technical Reports Server (NTRS)

    Paciorek, K. L.; Masuda, S. R.; Nakahara, J. H.; Kratzer, R. H.

    1987-01-01

    The objective of this program was to optimize and scale up the linear perfluoroalkylether stabilization process and to provide test data regarding the fluids' thermal oxidative stability in the presence of metal alloys. The stabilization of Fomblin Z-25 was scaled up to 300 g of fluid. The modified fluid was stable at 316 C in oxygen in the presence of M-50 alloy for more than 24 hrs but less than 40 hrs; the amount of volatiles produced after 24 hrs was 5.5 mg/g. In the presence of Ti(4Al,4Mn) alloy, under the above conditions, following an exposure of 24 hrs, the amount of volatiles formed was 6.2 mg/g; 56 hrs exposure yielded 13.9 mg/g. The commercial fluid at 288 C (in oxygen) in the presence of M-50 after 15 hrs of exposure decomposed extensively, 342 mg/g; in the presence of Ti(4Al,4Mn) alloy after only 8 hrs at 288 C, the amount of volatiles was 191 mg/g. Formulation of the commercial fluid with C2PN3 additive was not as effective as the stabilization processing. All the perfluoroalkylether fluids studied were stable in nitrogen at 343 C. The thermal oxidative stability in the absence of metal alloys varied, with Aflunox exhibiting the best behavior. All the fluids were degraded in oxygen at 316 C during 24 hrs exposure to Ti(4Al,4Mn) alloy with the exception of a perfluoroalkylether substituted triazine and the modified Z-25.

  11. Orbital Fluid Transfer System

    NASA Technical Reports Server (NTRS)

    Johnston, A. S., (Nick); Ryder, Mel; Tyler, Tony R.

    1998-01-01

    An automated fluid and power interface system needs to be developed for future space missions which require on orbit consumable replenishment. Current method of fluid transfer require manned vehicles and extravehicular activity. Currently the US does not have an automated capability for consumable transfer on-orbit. This technology would benefit both Space Station and long duration satellites. In order to provide this technology the Automated Fluid Interface System (AFIS) was developed. The AFIS project was an advanced development program aimed at developing a prototype satellite servicer for future space operations. This mechanism could transfer propellants, cryogens, fluids, gasses, electrical power, and communications from a tanker unit to the orbiting satellite. The development of this unit was a cooperative effort between Marshall Space Flight Center in Huntsville, Alabama, and Moog, Inc. in East Aurora, New York. An engineering model was built and underwent substantial development testing at Marshall Space Flight Center (MSFC). While the AFIS is not suitable for spaceflight, testing and evaluation of the AFIS provided significant experience which would be beneficial in building a flight unit. The lessons learned from testing the AFIS provided the foundation for the next generation fluid transfer mechanism, the Orbital Fluid Transfer System (OFTS). The OFTS project was a study contract with MSFC and Moog, Inc. The OFTS was designed for the International Space Station (ISS), but its flexible design could used for long duration satellite missions and other applications. The OFTS was designed to be used after docking. The primary function was to transfer bipropellants and high pressure gases. The other items addressed by this task included propellant storage, hardware integration, safety and control system issues. A new concept for high pressure couplings was also developed. The results of the AFIS testing provided an excellent basis for the OFTS design. The OFTS

  12. Solubility Control of Technetium Release from Saltstone by Tc02•xH20

    SciTech Connect

    Cantrell, Kirk J.; Williams, Benjamin D.

    2013-11-12

    Saltstone leaching experiments were conducted using a modified single-pass flow-through method under anoxic conditions. The analytical results of leachates collected from these experiments were evaluated using thermodynamic modeling to determine if the data were consistent with potential solubility controlling phases. The results demonstrate that technetium concentrations in water in contact with Saltstone under anoxic conditions is controlled by the solubility of TcO2•xH2O (likely TcO2•1.6H2O). In our system equilibrium solubility appears to have been reached within two weeks at a concentration of approximately 1.5 x 10-6 M. This concentration is likely to vary as the composition of Saltstone pore fluid evolves over time. As the pH goes from the initial high values (~12.5-13) to lower values, the solubility of technetium will decrease significantly. The thermodynamic data used to determine the solubility of TcO2•1.6H2O were taken from the tabulation of critically selected thermodynamic data determined by the Nuclear Energy Agency. Solid phase characterization to demonstrate the presence of TcO2•xH2O was not possible due to the low concentrations of technetium in our samples. Previous solid phase characterization studies with cementitious waste forms that were very similar to our Saltstone samples as well as reaction products derived from reductive immobilization of TcO4- by amorphous FeS clearly indicate the presence of TcO2 with varying degrees of hydration. Although, the presence of TcSx or other reduced technetium sulfide phases in our samples cannot be ruled out, release of technetium from Saltstone will be controlled by TcO2•1.6H2O because of its higher solubility. Our results clearly demonstrate that the release mechanism of technetium from Saltstone under reducing conditions is solubility controlled by TcO2•xH2O (likely TcO2•1.6H2O); however, distribution coefficients (Kds), that describe sorption and not solubility, were calculated for

  13. Experimental evidence for high noble gas solubilities in silicate melts under mantle pressures

    NASA Astrophysics Data System (ADS)

    Schmidt, Burkhard C.; Keppler, Hans

    2002-02-01

    The solubilities of Ar and Xe in Fe-free synthetic haplogranitic and tholeiitic melts were experimentally determined in the pressure range of 1-11 GPa and at temperatures between 1500 and 2000°C. Experiments were performed in a piston cylinder apparatus (1-3 GPa) and in a multi-anvil apparatus (2-11 GPa). The noble gas concentrations in the quenched glasses were determined with electron microprobe. As a function of pressure, Ar solubility increases linearly up to about 4-5 GPa where it reaches about 4.0 and 0.8 wt% for the haplogranitic and tholeiitic melt, respectively. At higher pressure the amount of dissolved Ar remains constant, suggesting that some threshold concentration is reached. The Xe solubility in tholeiite melt exhibits a very similar pattern. It increases linearly up to about 6 GPa, where a threshold concentration of 0.8 wt% is reached. A further increase of pressure up to 11 GPa does not result in changes in Xe solubility. The leveling off in noble gas solubility at high pressures may imply that the interstitial sites in the melt structure, suitable for the accommodation of noble gas atoms, are fully occupied. Indeed, the experimental data can be successfully reproduced with the Langmuir isotherm, implying a solubility model in which the gas atoms occupy a certain population of interstitial sites. However, the data can be equally well described by a model assuming mixing of the noble gas atoms with the oxygen atoms of the silicate melt. From a thermodynamic point of view, the constant noble gas solubility at high pressures simply implies that the partial molar volumes of the respective noble gas in the fluid and in the melt are equal. Our results differ from those of Chamorro-Perez et al. [Earth Planet. Sci. Lett. 145 (1996) 97-107; Nature 393 (1998) 352-355] who reported an abrupt, order-of-magnitude drop of Ar solubility in silica and olivine melt at around 5 GPa, suggesting that melt densification results in an abrupt decrease of the hole size

  14. Application of mineral bed materials during fast pyrolysis of rice husk to improve water-soluble organics production.

    PubMed

    Li, R; Zhong, Z P; Jin, B S; Zheng, A J

    2012-09-01

    Fast pyrolysis of rice husk was performed in a spout-fluid bed to produce water-soluble organics. The effects of mineral bed materials (red brick, calcite, limestone, and dolomite) on yield and quality of organics were evaluated with the help of principal component analysis (PCA). Compared to quartz sand, red brick, limestone, and dolomite increased the yield of the water-soluble organics by 6-55% and the heating value by 16-19%. The relative content of acetic acid was reduced by 23-43% with calcite, limestone and dolomite when compared with quartz sand. The results from PCA showed all minerals enhanced the ring-opening reactions of cellulose into furans and carbonyl compounds rather than into monomeric sugars. Moreover, calcite, limestone, and dolomite displayed the ability to catalyze the degradation of heavy compounds and the demethoxylation reaction of guaiacols into phenols. Minerals, especially limestone and dolomite, were beneficial to the production of water-soluble organics.

  15. Oxygen supersaturated fluid using fine micro/nanobubbles

    PubMed Central

    Matsuki, Noriaki; Ishikawa, Takuji; Ichiba, Shingo; Shiba, Naoki; Ujike, Yoshihito; Yamaguchi, Takami

    2014-01-01

    Microbubbles show peculiar properties, such as shrinking collapse, long lifetime, high gas solubility, negative electric charge, and free radical production. Fluids supersaturated with various gases can be easily generated using microbubbles. Oxygen microbubble fluid can be very useful for oxygen delivery to hypoxic tissues. However, there have been no reports of comparative investigations into adding fluids containing oxygen fine micro/nanobubbles (OFM-NBs) to common infusion solutions in daily medical care. In this study, it was demonstrated that OFMNBs can generate oxygen-supersaturated fluids, and they may be sufficiently small to infuse safely into blood vessels. It was found that normal saline solution is preferable for generating an oxygen-rich infusion fluid, which is best administered as a 30-minute intravenous infusion. It was also concluded that dextran solution is suitable for drug delivery substances packing oxygen gas over a 1-hour intravenous infusion. In addition, normal saline solution containing OFMNBs was effective for improving blood oxygenation. Thus, the use of OFMNB-containing fluids is a potentially effective novel method for improving blood oxygenation in cases involving hypoxia, ischemic diseases, infection control, and anticancer chemoradiation therapies. PMID:25285003

  16. Effect Of Pressure On The Temperature Dependence Of Water Solubility In Forsterite

    NASA Astrophysics Data System (ADS)

    Bali, E.; Bolfan-Casanova, N.; Koga, K.

    2005-12-01

    Water storage capacity of the upper mantle largely depends on water solubility in mantle olivine. Realistic models must take into account the simultaneous effects of variables such as pressure, temperature, iron content and silica activity. Previous experimental studies have shown that the water solubility in olivine increases with increasing water fugacity up to 12 GPa at 1100°C. Water incorporation in olivine was also observed to increase with increasing temperature and increasing iron content at 0.3 GPa, however the temperature dependence was not studied at higher pressures. Interestingly, the only high-pressure data available, that is for wadsleyite and ringwoodite, show that their water solubility decreases with increasing temperature. The goal of this study is to determine the dependence of water maximum concentration on temperature at pressures higher than 0.3 GPa. We performed experiments at 3 and 6 GPa, and temperatures ranging from 1000 to 1400°C in the MgO-SiO2-H2O system using a multi-anvil apparatus. The olivine and orthopyroxene molar ratio was 1 to 1 in the starting material with 5 wt% H2O. The samples were analyzed using scanning electron microscopy and Fourier transform infrared spectroscopy. The mineralogical assemblage consisted of olivine+orthopyroxene+fluid at temperatures below 1250°C both at 3 and 6 GPa and olivine+melt+/-orthopyroxene at higher temperatures. At 3 GPa, above 1325°C orthopyroxene was missing from the assemblage, whereas in case of the 6 GPa experiments it was present even at higher temperatures. This indicates a change in fluid composition from 3 to 6 GPa. Preliminary data using unpolarized FTIR measurements, but comparing same orientations, indicate that water solubility in olivine at 6 GPa decreases with increasing temperature. This observation agrees with the results on wadsleyite and ringwoodite, but contradict the results of the existing low-pressure data. The explaination we propose for the change in temperature

  17. Thermodynamics of geothermal fluids

    SciTech Connect

    Rogers, P.S.Z.

    1981-03-01

    A model to predict the thermodynamic properties of geothermal brines, based on a minimum amount of experimental data on a few key systems, is tested. Volumetric properties of aqueous sodium chloride, taken from the literature, are represented by a parametric equation over the range 0 to 300{sup 0}C and 1 bar to 1 kbar. Density measurements at 20 bar needed to complete the volumetric description also are presented. The pressure dependence of activity and thermal properties, derived from the volumetric equation, can be used to complete an equation of state for sodium chloride solutions. A flow calorimeter, used to obtain heat capacity data at high temperatures and pressures, is described. Heat capacity measurements, from 30 to 200{sup 0}C and 1 bar to 200 bar, are used to derive values for the activity coefficient and other thermodynamic properties of sodium sulfate solutions as a function of temperature. Literature data on the solubility of gypsum in mixed electrolyte solutions have been used to evaluate model parameters for calculating gypsum solubility in seawater and natural brines. Predictions of strontium and barium sulfate solubility in seawater also are given.

  18. Amniotic fluid embolism

    PubMed Central

    Kaur, Kiranpreet; Bhardwaj, Mamta; Kumar, Prashant; Singhal, Suresh; Singh, Tarandeep; Hooda, Sarla

    2016-01-01

    Amniotic fluid embolism (AFE) is one of the catastrophic complications of pregnancy in which amniotic fluid, fetal cells, hair, or other debris enters into the maternal pulmonary circulation, causing cardiovascular collapse. Etiology largely remains unknown, but may occur in healthy women during labour, during cesarean section, after abnormal vaginal delivery, or during the second trimester of pregnancy. It may also occur up to 48 hours post-delivery. It can also occur during abortion, after abdominal trauma, and during amnio-infusion. The pathophysiology of AFE is not completely understood. Possible historical cause is that any breach of the barrier between maternal blood and amniotic fluid forces the entry of amniotic fluid into the systemic circulation and results in a physical obstruction of the pulmonary circulation. The presenting signs and symptoms of AFE involve many organ systems. Clinical signs and symptoms are acute dyspnea, cough, hypotension, cyanosis, fetal bradycardia, encephalopathy, acute pulmonary hypertension, coagulopathy etc. Besides basic investigations lung scan, serum tryptase levels, serum levels of C3 and C4 complements, zinc coproporphyrin, serum sialyl Tn etc are helpful in establishing the diagnosis. Treatment is mainly supportive, but exchange transfusion, extracorporeal membrane oxygenation, and uterine artery embolization have been tried from time to time. The maternal prognosis after amniotic fluid embolism is very poor though infant survival rate is around 70%. PMID:27275041

  19. Boiler using combustible fluid

    DOEpatents

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  20. Fluid Mechanics: The Pamphlet

    NASA Astrophysics Data System (ADS)

    Variano, Evan

    2012-11-01

    One impediment to student learning in introductory fluid mechanics courses is that the fundamental laws of physics can become lost in the ``noise'' of dozens of semi-empirical equations describing special cases. This can be exacerbated by trends in textbooks and other teaching media. This talk will explore a minimalist approach, whereby the entire content of introductory fluids is distilled to a single 1-page pamphlet, designed to emphasize the governing equations and their near-universal applicability. We are particularly interested in hearing feedback from the audience on ways to further distill the content while keeping it accessible and useful. To further emphasize the difference between the fundamental laws and the many specific cases, we have begun assembling a complementary resource: a field guide to fluid phenomena, which mixes the approach of Van Dyke's book with a standard field guide. This is designed to emphasize that there is a ``zoology'' of fluid phenomena, to which the same small set of fundamental laws has been applied repeatedly. These materials may be useful in helping AP Physics teachers cover fluid mechanics, which is an under-utilized opportunity to introduce young scientists to our field of study.