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Sample records for aot water reverse

  1. Ultrafast energy transfer in water-AOT reverse micelles

    NARCIS (Netherlands)

    Cringus, Dan; Bakulin, Artem; Lindner, Joerg; Voehringer, Peter; Pshenichnikov, Maxim S.; Wiersma, Douwe A.

    2007-01-01

    A spectroscopic investigation of the vibrational dynamics of water in a geometrically confined environment is presented. Reverse micelles of the ternary microemulsion H2O/AOT/n-octane (AOT = bis-2-ethylhexyl sulfosuccinate or aerosol-OT) with diameters ranging from 1 to 10 nm are used as a model sys

  2. Ultrafast energy transfer in water-AOT reverse micelles.

    Science.gov (United States)

    Cringus, Dan; Bakulin, Artem; Lindner, Jörg; Vöhringer, Peter; Pshenichnikov, Maxim S; Wiersma, Douwe A

    2007-12-27

    A spectroscopic investigation of the vibrational dynamics of water in a geometrically confined environment is presented. Reverse micelles of the ternary microemulsion H2O/AOT/n-octane (AOT = bis-2-ethylhexyl sulfosuccinate or aerosol-OT) with diameters ranging from 1 to 10 nm are used as a model system for nanoscopic water droplets surrounded by a soft-matter boundary. Femtosecond nonlinear infrared spectroscopy in the OH-stretching region of H2O fully confirms the core/shell model, in which the entrapped water molecules partition onto two molecular subensembles: a bulk-like water core and a hydration layer near the ionic surfactant headgroups. These two distinct water species display different relaxation kinetics, as they do not exchange vibrational energy. The observed spectrotemporal ultrafast response exhibits a local character, indicating that the spatial confinement influences approximately one molecular layer located near the water-amphiphile boundary. The core of the encapsulated water droplet is similar in its spectroscopic properties to the bulk phase of liquid water, i.e., it does not display any true confinement effects such as droplet-size-dependent vibrational lifetimes or rotational correlation times. Unlike in bulk water, no intermolecular transfer of OH-stretching quanta occurs among the interfacial water molecules or from the hydration shell to the bulk-like core, indicating that the hydrogen bond network near the H2O/AOT interface is strongly disrupted. PMID:18047308

  3. Integral physicochemical properties of reverse micelles of sodium bis(2-ethylhexyl) sulfosuccinate (AOT)

    Science.gov (United States)

    Fedyaeva, O. A.; Shubenkova, E. G.; Poshelyuzhnaya, E. G.; Lutaeva, I. A.

    2016-08-01

    The effect the degree of hydration has on optical and electrophysical properties of water/AOT/ n-hexane system is studied. It is found that AOT reverse micelles form aggregates whose dimensions grow along with the degree of hydration and temperature. Aggregation enhances their electrical conductivity and shifts the UV spectrum of AOT reverse emulsions to the red region. Four states of water are found in the structure of AOT reverse micelles.

  4. Kinetic Studies on the Lignin Peroxidase Catalyzed Oxidation of Veratryl Alcohol by H2O2 in AOT/Isooctane/Toluene/Water Reverse Micelles

    Institute of Scientific and Technical Information of China (English)

    LIU Jin-Ting; HUANG Xi-Rong; GAO Pei-ji

    2007-01-01

    The steady state kinetics of the lignin peroxidase (LIP) catalyzed oxidation of veratryl alcohol (VA) by H2O2 in a sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane/toluene/water reverse micellar medium was studied and a comparison with the corresponding aqueous medium was made to understand the effect of the reverse micellar medium on the catalytic mechanism and kinetic parameters. Results indicated that the model reaction in the AOT medium were the same as those in bulk aqueous medium, but the kinetic parameters except Km,H2O2 were greatly different in the two media. The kcat and Ki values in the reverse micelle were approximately 2 and 20 times smaller than the corresponding values in the aqueous solution, but the Michaelis constant of VA was approximately 100times greater than that in the aqueous solution. The above mentioned differences in the kinetic parameters were caused by the microheterogeneity and the interface of the AOT reverse micelle, which resulted in the partitioning of VA and H2O2, and by the changes of the conformation of LiP and the reactivity of the substrates.

  5. Wallenius waters AOT luftrenare

    OpenAIRE

    Panagoulas, Dimitri

    2012-01-01

    This bachelors thesis was made for Wallenius Water AB to develop a basis for an Air purifier prototype. Wallenius Water is one of the world's leading environmental technology companies engaged in chemical-free water treatment based on UV-radiation. The thesis aim was to produce a basis for a prototype that can be used in three applications: Standalone, RAS systems and ventilation systems. The work includes an introductory description of the theory behind AOP technology based on a literature r...

  6. Photophysical properties of pyronin dyes in reverse micelles of AOT

    International Nuclear Information System (INIS)

    The photophysical properties of pyronin B (PyB) and pyronin Y (PyY) in reverse micelles formed with water/sodium bis (2-ethyl-1-hexyl) sulfosuccinate (AOT)/n-heptane were investigated by UV–vis absorption, steady-state and time-resolved fluorescence spectroscopy techniques. This study was carried out a wide range of reverse micelle sizes, with hydrodynamic radii ranging from 1.85 to 9.38 nm. Significant photophysical parameters as band shifts, fluorescence quantum yields and fluorescence lifetimes were determined to understand how photophysical and spectroscopic features of the dye compounds were affected by the variation of reverse micelle sizes. In this regard, control of reverse micelle size by changing W0, the molar ratio of water to surfactant, allowed tuning the photophysical properties of the dyes in organic solvent via reverse micelle. Non-fluorescent H-aggregates of pyronin dyes were observed for the smaller reverse micelles whereas an increase in the reverse micelle size induced an increment in the amount of dye monomers instead of dye aggregates. Thus, the fluorescence intensities of the dyes were improved by increasing W0 due to the predomination of the fluorescent dye monomers. As a result, the fluorescence quantum yields also increased. The fluorescence lifetimes of the dyes in the reverse micelles were determined by the time-resolved fluorescence decay studies. Evaluation of the fluorescence lifetimes calculated for pyronin dyes in the reverse micelles showed that the size of reverse micelle affected the fluorescence lifetimes of pyronin dyes. -- Highlights: • The photophysical properties of pyronin dyes were examined by spectroscopic techniques. • Optical properties of the dyes were tuned by changing of W0 values. • The fluorescence lifetime and quantum yield values of the dyes in reverse micelles were discussed

  7. "Snap-shooting" the interface of AOT reverse micelles: use of chemical trapping

    Science.gov (United States)

    Srilakshmi; Chaudhuri

    2000-08-01

    The first use of the phenyl cation trapping technique in "snap-shooting" the local molar concentrations of water and sulfosuccinate head-groups in the interfacial region of AOT-2,2,4-trimethylpentane-water reverse micelles has been accomplished. Our results demonstrate that the interfacial concentrations of the sulfosuccinate head-groups in AOT (0.1 M)-2,2,4-trimethylpentane-water reverse micelles are remarkably high (2.75-2.34 M) across the W0 (the molar ratio of water to surfactant) range 12 to 44. However, the interfacial concentrations of water in AOT- 2,2,4-trimethylpentane-water reverse micelles across the same range of solution compositions are significantly lower (27.9-32.0 M) than the molar concentration of bulk water (55.5 M). The present results provide new insight on the microenvironments of interfacially located enzymes such as lipases entrapped in AOT-2,2,4-trimethylpentane-water reverse micelles, the most extensively exploited reverse-micellar system in micellar biotechnology. PMID:10985732

  8. Interactions between crystal violet and AOT in aqueous solutions and in AOT/isooctane/water microemulsions

    Institute of Scientific and Technical Information of China (English)

    HAO Xiaojuan; AN Xueqin; CHEN Zhiyun; SHEN Weiguo

    2004-01-01

    The absorbance of crystal violet (CV) in a series of aqueous solutions and a series of sodium bis(2-ethyl- hexyl) sulfosuccinate (AOT)/isooctane/water microemulsions has been determined. Association models have been used to analyse the experimental data to obtain the association constants of CV and AOT in the above two media. It was found that about up to 57% CV was associated by AOT in AOT/ isooctane/water microemulsions, which reduced the reaction rate of alkaline fading of crystal violet in the microemulsions.

  9. Molecular Dynamics Simulations of Cytochrome c un-folding in AOT Reverse Micelles: the first steps

    CERN Document Server

    Abel, Stéphane; Marchi, Massimo

    2009-01-01

    This paper explores the reduced form of horse cytochrome c confined in reverse micelles (RM) of so-dium bis-(2-ethylhexyl) sulfosuccinate (AOT) in isooctane by molecular dynamics simulation. RMs of two sizes were constructed at a water content of Wo = [H2O]/[AOT] = 5.5 and 9.1. Our results show that the protein secondary structure and the heme conformation both depend on micellar hydration. At low hydration, the protein structure and the heme moiety remain stable, whereas at high water content the protein becomes unstable and starts to unfold. At Wo = 9.1, according to the X-ray structure, conforma-tional changes are mainly localized on protein loops and around the heme moiety, where we observe a partial opening of the heme crevice. These findings suggest that within our time window (10 ns), the structural changes observed at the heme level are the first steps of the protein denaturation process, pre-viously described experimentally in micellar solutions. In addition, a specific binding of AOT molecules to a ...

  10. Dynamics of electron attachment to AOT/H2O reversed micelles

    International Nuclear Information System (INIS)

    Values of the observed rate constant, κobs, of excess electrons attaching to aerosol OT (AOT) reversed micelles encapsulating varying quantities of water were measured in isooctane and tetramethylsilane (TMS) at 21 degrees C using a picosecond-pulse conductivity technique. Dynamic light scattering was used to determine the micellar radii in TMS from which aggregation numbers of the micelles were determined. In the lower-mobility isooctane (μe = 5.3 cm2/(V s)), values of the κobs approach the diffusion-controlled attachment rate, κobs in TMS (μ3 = 100 cm2/(V s)) are 8-fold less than κd at the maximum ratio of H2O/AOT = 27 that was studied. Several factors that could contribute to κobs appearing to exceed κd in isooctane are discussed, and the less efficient attachment of electrons to the same reversed micelles in TMS compared to attachment in isooctane is interpreted in terms of the relative attachment time, τr. With this model, the τa of electrons attaching to micelles at a diffusion-controlled rate is <1 ps and may be identified with the solvation time of electrons in water. 54 refs., 5 figs., 2 tabs

  11. More evidence on the control of reverse micelles sizes. Combination of different techniques as a powerful tool to monitor AOT reversed micelles properties.

    Science.gov (United States)

    Durantini, Andrés M; Falcone, R Darío; Silber, Juana J; Correa, N Mariano

    2013-04-11

    In this work, we have investigated the behavior of 4-aminophthalimide (4-AP) in solvent mixtures of ethyl lactate (EL)- water and EL-n-heptane and in reversed micelles (RMs) media made of EL-water/sodium 1,4-bis(2-ethylhexyl)sulfosuccinate (AOT)/n-heptane. We have used dynamics light scattering (DLS) and absorption, steady-state and time-resolved emission (TRES) techniques. 4-AP is a very interesting and unique molecule used to study preferential solvation in water mixtures since its emission profile changes dramatically when its sphere shell is solvated by water molecules. Thus, in homogeneous media 4-AP is strongly solvated by water in the EL-water mixture and by EL in the EL-n-heptane mixture, results that show the importance of the hydrogen bonding in the 4-AP solvation. We were motivated by this feature of 4-AP and have used it to monitor properties in AOT RMs. Thus, we use 4-AP spectroscopic behavior in conjunction with DLS technique to reveal the location of each polar solvent of the mixture encapsulated within the RMs media. We found that in the EL-water/AOT/n-heptane RMs the results strongly depend on the amount of water dissolved. Below W0 = [water]/[AOT] = 5, there are no reversed micelles and EL, water, AOT and n-heptane forms a nonstructured mixture. For W0 values between 5 and 10, the droplet sizes are independent of the EL content because of its strong intermolecular interactions forms an EL polar core and only water is found at the interface. For W0 values higher than 10, the droplets size increase with the EL content and EL molecules are detected at the AOT RMs interface. We inferred that the RMs sizes will change only if the polar solvent encapsulated interacts with the interface changing the surfactant packing parameter. Then, we can assume that it is possible to create RMs with solvents that do not interact with the interface but can be encapsulated in the polar core. These results, give evidence that expand the knowledge about which are the

  12. Real structure of formamide entrapped by AOT nonaqueous reverse micelles: FT-IR and 1H NMR studies.

    Science.gov (United States)

    Correa, N Mariano; Pires, Paulo Augusto R; Silber, Juana J; El Seoud, Omar A

    2005-11-10

    Noninvasive techniques such as FT-IR and (1)H NMR spectroscopy have been employed to investigate the solubilization of formamide, FA, and its aqueous solution, FA-water, by sodium 1,4-bis(2-ethylhexyl)sulfosuccinate, AOT, in heptane or isooctane reverse micelles, respectively. Partially deuterated FA (FADH) was used in the FT-IR experiments and nu(OD), n(ND) were analyzed. Also, the nu(C=O) band of FA was investigated. For AOT, the changes of the SO(3)(-) group's symmetric, nu(s), and asymmetric, nu(a), bands were also studied. The results are showing that FA is interacting strongly with the Na+ counterions of the surfactant through electrostatic interactions maintaining their hydrogen bond network present in the FA bulk. Accordingly, partially deuterated FA is "frozen" inside the aggregates and it is possible to detect, by FT-IR technique, the cis and trans isomers. Curve fitting of the nu(OD) (in the FA-water mixture) band requires use of two peaks because the band is asymmetric, not because the solubilizate molecules are present in layers of different structure. The chemical shifts of the (1)H bound to N and C of FA were studied by (1)H NMR. The comparison of the chemical shift of AOT in reverse micelles with FA and the FA-water mixture in the polar core of the aggregate shows that there is a strong preferential solvation of Na+ by FA (through electrostatic interaction) and the AOT's sulfonate group by water (through hydrogen bond interaction). PMID:16853748

  13. Electron-transfer reactions between viologen radical cations and quinones in AOT reverse micelles studied by electron pulse radiolysis

    International Nuclear Information System (INIS)

    Electron-transfer reactions between viologen radical cations (CnVsm-bullet+, n = 1-18) and various quinones have been studied in aqueous and reverse micellar (AOT/isooctane/H2O) solution by use of the electron pulse radiolysis technique. By use of dynamic light scattering measurements, the concentration of water pools was determined and the number of electron-transfer reactants per water pool could be calculated. Rate constants measured for the reaction between CnVsm-bullet+ radicals and anthraquinonesulfonate ions (AQS-) decreased with increasing length of the aliphatic chain of the viologens, caused by association of the viologen with the surfactant interface

  14. Extraction of cobalt ion using reverse-micelle of F-AOT in liquid/supercritical CO2

    International Nuclear Information System (INIS)

    A green decontamination method using CO2 as an environmentally benign solvent has been studied for removal of contaminant in the nuclear power plant. We developed a decontamination technique using CO2 for removal of contamination in working dresses. Owing to the low solubilizing, A reverse micelle system was developed. Fluorinated AOT was synthesized and used as surfactants forming reverse-micelle with water. Cobalt was extracted by dissolution into reverse-micelle in liquid CO2. If this decontamination technique is applied to nuclear industry, the secondary waste during decontamination will be reverentially reduced. Negligibly small amount of water is a net waste, while the surfactants and solvent CO2 are recovered and reused in the system

  15. Activity, stability and kinetic parameters for -chymotrypsin catalysed reactions in AOT/isooctane reverse micelles with nonionic and zwitterionic mixed surfactants

    Indian Academy of Sciences (India)

    Santosh Kumar Verma; Kallol K Ghosh

    2013-07-01

    Reverse micelles (RMs) of sodium 1,4-bis(2-ethylhexyl)sulphosuccinate (AOT) in nonpolar organic solvents are widely known to have very high solubilization power for water. The method is applied to the hydrolysis of -nitrophenyl acetate (PNPA) catalysed by -chymotrypsin (-CT) in AOT/isooctane/buffer RMs. The increase in -CT activity and stability was an optimum at wo ([H2O]/[AOT]) = 10, z [Isooctane]/[AOT]) = 5. Three typical surfactants were selected based on their head group charges: a non-ionic surfactant Triton-X 100 and two zwitterionic sulphobetaine surfactants of the type CH2+1N+Me2 (CH2)3 SO$^{−}_{3}$ (n = 10; SB3-10, n = 16; SB3-16). The kinetic parameters (such as cat and M) of the -CT at 27°C were determined and compared in the absence and presence of three surfactants. The effect of chain length of zwitterionic surfactant (SB3-10 and SB3-16) on the enzymatic efficacy of -CT as a function of mixed surfactant addition has been investigated in AOT/isooctane RMs at pH 7.75.

  16. Lipophilic porphyrin microparticles induced by AOT reverse micelles: a fluorescence lifetime imaging study.

    Science.gov (United States)

    Togashi, Denisio M; Costa, Sílvia M B; Sobral, Abílio J F N

    2006-01-20

    Fluorescence Lifetime Imaging Microscopy (FLIM) technique was applied to investigate the fluorescence dynamics and structural features of large colloidal aggregates of meso-tetra(N-dodecyl-4-amino sulfonyl-phenyl)porphyrin (PC12) induced by Sodium 1,4-bis(2-ethyl hexyl)sulfosuccinate (AOT) reverse micelles. The aggregate's particle sizes (down to 1 microm) obtained from the confocal fluorescence images matched with the particle sizes measured in the images obtained from Scanning Electron Microscopy (SEM). The fluorescence decays for those aggregates in the micro spatial domain show triexponential fluorescence lifetimes (tau1 approximately 12 ns, tau2 approximately 3 ns and tau3 approximately 1 ns) which are independent of the aggregate's size. PMID:16154681

  17. Validation and divergence of the activation energy barrier crossing transition at the AOT/lecithin reverse micellar interface.

    Science.gov (United States)

    Narayanan, S Shankara; Sinha, Sudarson Sekhar; Sarkar, Rupa; Pal, Samir Kumar

    2008-03-13

    In this report, the validity and divergence of the activation energy barrier crossing model for the bound to free type water transition at the interface of the AOT/lecithin mixed reverse micelle (RM) has been investigated for the first time in a wide range of temperatures by time-resolved solvation of fluorophores. Here, picosecond-resolved solvation dynamics of two fluorescent probes, ANS (1-anilino-8-naphthalenesulfonic acid, ammonium salt) and Coumarin 500 (C-500), in the mixed RM have been carefully examined at 293, 313, 328, and 343 K. Using the dynamic light scattering (DLS) technique, the size of the mixed RMs at different temperatures was found to have an insignificant change. The solvation process at the reverse micellar interface has been found to be the activation energy barrier crossing type, in which interface-bound type water molecules get converted into free type water molecules. The activation energies, Ea, calculated for ANS and C-500 are 7.4 and 3.9 kcal mol(-1), respectively, which are in good agreement with that obtained by molecular dynamics simulation studies. However, deviation from the regular Arrhenius type behavior was observed for ANS around 343 K, which has been attributed to the spatial heterogeneity of the probe environments. Time-resolved fluorescence anisotropy decay of the probes has indicated the existence of the dyes in a range of locations in RM. With the increase in temperature, the overall anisotropy decay becomes faster revealing the lability of the microenvironment at elevated temperatures. PMID:18281975

  18. Effect of the constrained environment on the interactions between the surfactant and different polar solvents encapsulated within AOT reverse micelles.

    Science.gov (United States)

    Durantini, Andrés M; Falcone, R Dario; Silber, Juana J; Correa, N Mariano

    2009-08-24

    Herein, we report a study of the interactions between different nonaqueous polar solvents, namely, ethylene glycol (EG), propylene glycol (PG), glycerol (GY), dimethylformamide (DMF), and dimethylacetamide (DMA), and the polar heads of sodium 1,4-bis-2-ethylhexylsulfosuccinate (AOT) in nonaqueous AOT/n-heptane reverse micelles. The goal of our study is to gain insights into the unique reverse-micelle microenvironment created upon encapsulation of these polar solvents. For the first time, the study is focused on determining which regions of the AOT molecular structure are involved in the interactions with the polar solvents. We use FTIR spectroscopy--a noninvasive technique--to follow the changes in the AOT C=O band and the symmetric and asymmetric SO(3)(-) vibration modes upon increasing the content of polar solvents in the micelles. The results show that GY interacts through H bonds with the SO(3)(-) group, thereby removing the Na(+) counterions from the interface remaining in the polar core of the micelles. PG and EG interact through H bonds, mainly with the C=O group of AOT, penetrating into the oil side of the interface. Thus, they interact weakly with the Na(+) counterion, which seems to be close to the AOT sulfonate group. Finally, DMF and DMA, encapsulated inside the reverse micelles, interact neither with the C=O nor with the SO(3)(-) groups, but their weakly bulk-associated structure is broken because of the interactions with Na(+). We suggest that DMF and DMA can complex the Na(+) ions through their carbonyl and nitrogen groups. Hence, our results do not only give insights into how the constrained environment affects the bulk properties of polar solvents encapsulated within reverse micelles but--more importantly--they also help us to answer the tricky question about which regions of the AOT moiety are involved in the interactions with the polar solvents. We believe that our results show a clear picture of the interactions present at the nonaqueous reverse

  19. Electron capture in water pools of reversed micelles

    International Nuclear Information System (INIS)

    The rate constants of excess electron attachment to reversed H2O-AOT micelles in liquid isooctane were measured by a picosecond pulse-conductivity technique at 220C. Electron attachment rates were less than the diffusion-controlled rate at molar ratios ω0 =[H2O]/[AOT] less than 12 but increased to the diffusion-controlled rate of approx. 1015M-1s-1 at ω0 = 37 where the micelle radius was approx. 100A. The transition from nondiffusion-controlled to diffusion-controlled electron attachment implies that free or non-AOT bound water in the micellar water pools is required for efficient electron attachment, which is consistent with earlier NMR, fluorescence, and polarization studies of electron capture by reversed H2O-AOT micelles

  20. Anomalous change in interfacial tension induced by collapses of AOT microemulsions at heptane/water interface

    Science.gov (United States)

    Takahashi, Masahiko; Yui, Hiroharu; Ikezoe, Yasuhiro; Sawada, Tsuguo

    2004-05-01

    Dynamic behavior of water-in-oil microemulsions at the oil/water interface was investigated using the quasi-elastic laser scattering method. We observed an anomalous rebound behavior of interfacial tension γ induced by collapses of microemulsions and adsorptions of AOT molecules at the interface. γ rapidly decreased and reached a minimum value (5.5 mN/m) at about 500 s after the preparation of the interface, and then increased gradually for about 2000 s to the equilibrium value (8.0 mN/m). We considered the mechanism of the rebound behavior in terms of transient change in interfacial thickness induced by the collapses of AOT microemulsions.

  1. Dielectric Properties of Water in Butter and Water-AOT-Heptane Systems Measured using Terahertz Time-Domain Spectroscopy

    DEFF Research Database (Denmark)

    Møller, Uffe; Folkenberg, Jacob Riis; Jepsen, Peter Uhd

    2010-01-01

    We investigate the dielectric properties of water confined in nanometer-sized inverse micelles in mixtures of water, AOT, and heptane. We show that the dielectric properties of the confined water are dependent on the water pool size and different from those of bulk water. We also discuss the...... dielectric properties of different vegetable oils, lard, and butter, and use these properties to deduce the dielectric properties of water in butter, which are shown to deviate significantly from the dielectric properties of bulk water....

  2. Exploring the role of hydration and confinement in the aggregation of amyloidogenic peptides Aβ(16-22) and Sup35(7-13) in AOT reverse micelles.

    Science.gov (United States)

    Martinez, Anna Victoria; Małolepsza, Edyta; Rivera, Eva; Lu, Qing; Straub, John E

    2014-12-14

    Knowledge of how intermolecular interactions of amyloid-forming proteins cause protein aggregation and how those interactions are affected by sequence and solution conditions is essential to our understanding of the onset of many degenerative diseases. Of particular interest is the aggregation of the amyloid-β (Aβ) peptide, linked to Alzheimer's disease, and the aggregation of the Sup35 yeast prion peptide, which resembles the mammalian prion protein linked to spongiform encephalopathies. To facilitate the study of these important peptides, experimentalists have identified small peptide congeners of the full-length proteins that exhibit amyloidogenic behavior, including the KLVFFAE sub-sequence, Aβ16-22, and the GNNQQNY subsequence, Sup357-13. In this study, molecular dynamics simulations were used to examine these peptide fragments encapsulated in reverse micelles (RMs) in order to identify the fundamental principles that govern how sequence and solution environment influence peptide aggregation. Aβ16-22 and Sup357-13 are observed to organize into anti-parallel and parallel β-sheet arrangements. Confinement in the sodium bis(2-ethylhexyl) sulfosuccinate (AOT) reverse micelles is shown to stabilize extended peptide conformations and enhance peptide aggregation. Substantial fluctuations in the reverse micelle shape are observed, in agreement with earlier studies. Shape fluctuations are found to facilitate peptide solvation through interactions between the peptide and AOT surfactant, including direct interaction between non-polar peptide residues and the aliphatic surfactant tails. Computed amide I IR spectra are compared with experimental spectra and found to reflect changes in the peptide structures induced by confinement in the RM environment. Furthermore, examination of the rotational anisotropy decay of water in the RM demonstrates that the water dynamics are sensitive to the presence of peptide as well as the peptide sequence. Overall, our results

  3. Micellar interactions in water-AOT based droplet microemulsions containing hydrophilic and amphiphilic polymers

    Science.gov (United States)

    Appel, Markus; Spehr, Tinka Luise; Wipf, Robert; Moers, Christian; Frey, Holger; Stühn, Bernd

    2013-11-01

    We investigate the influence of addition of hydrophilic and amphiphilic polymer on percolation behavior and micellar interactions in AOT-based water-in-oil droplet microemulsions. We focus on two series of samples having constant molar water to surfactant ratio W = 20 and constant droplet volume fraction Φ = 30%, respectively. From dielectric spectroscopy experiments, we extract the bending rigidity of the surfactant shell by percolation temperature measurements. Depending on droplet size, we find stabilization and destabilization of the surfactant shell upon addition of hydrophilic poly(ethylene glycol) (PEG) (Mn = 3100 g mol-1) and amphiphilic poly(styrene)-b-poly(ethylene glycol) copolymer with comparable length of the hydrophilic block. Complementary small angle X-ray scattering experiments corroborate the finding of stabilization for smaller droplets and destabilization of larger droplets. Subsequent analysis of dielectric spectra enables us to extract detailed information about micellar interactions and clustering by evaluating the dielectric high frequency shell relaxation. We interpret the observed results as a possible modification of the inter-droplet charge transfer efficiency by addition of PEG polymer, while the amphiphilic polymer shows a comparable, but dampened effect.

  4. Correlation of insulin-enhancing properties of vanadium-dipicolinate complexes in model membrane systems: phospholipid langmuir monolayers and AOT reverse micelles.

    Science.gov (United States)

    Sostarecz, Audra G; Gaidamauskas, Ernestas; Distin, Steve; Bonetti, Sandra J; Levinger, Nancy E; Crans, Debbie C

    2014-04-22

    We explore the interactions of V(III) -, V(IV) -, and V(V) -2,6-pyridinedicarboxylic acid (dipic) complexes with model membrane systems and whether these interactions correlate with the blood-glucose-lowering effects of these compounds on STZ-induced diabetic rats. Two model systems, dipalmitoylphosphatidylcholine (DPPC) Langmuir monolayers and AOT (sodium bis(2-ethylhexyl)sulfosuccinate) reverse micelles present controlled environments for the systematic study of these vanadium complexes interacting with self-assembled lipids. Results from the Langmuir monolayer studies show that vanadium complexes in all three oxidation states interact with the DPPC monolayer; the V(III) -phospholipid interactions result in a slight decrease in DPPC molecular area, whereas V(IV) and V(V) -phospholipid interactions appear to increase the DPPC molecular area, an observation consistent with penetration into the interface of this complex. Investigations also examined the interactions of V(III) - and V(IV) -dipic complexes with polar interfaces in AOT reverse micelles. Electron paramagnetic resonance spectroscopic studies of V(IV) complexes in reverse micelles indicate that the neutral and smaller 1:1 V(IV) -dipic complex penetrates the interface, whereas the larger 1:2 V(IV) complex does not. UV/Vis spectroscopy studies of the anionic V(III) -dipic complex show only minor interactions. These results are in contrast to behavior of the V(V) -dipic complex, [VO2 (dipic)](-) , which penetrates the AOT/isooctane reverse micellar interface. These model membrane studies indicate that V(III) -, V(IV) -, and V(V) -dipic complexes interact with and penetrate the lipid interfaces differently, an effect that agrees with the compounds' efficacy at lowering elevated blood glucose levels in diabetic rats. PMID:24615733

  5. Photoluminescence and chemical properties of ZnS:Mn2+ nanocrystal powder synthesized in the AOT reverse micelles modified with lauryl phosphate

    International Nuclear Information System (INIS)

    A transparent colloidal solution of the ZnS:Mn2+ nanocrystal was prepared in hybrid reverse micelles comprising two kinds of surfactants: sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and lauryl phosphate (HLP). Then, the powdered sample was obtained from the colloidal solution by coagulation of these micelles. Modification of HLP surfactant increases the photoluminescence (PL) intensity due to the d-d transition of Mn2+ ions for both of the colloidal solution and the powder. FT-IR spectra and energy dispersive X-ray analysis (EDX) data reveal that HLP modifies ZnS:Mn2+ nanocrystals more preferentially than AOT. The detailed investigation on chemical interaction between HLP molecules and ZnS nanocrystals with and without Mn2+ is performed by solid-state nuclear magnetic resonance (NMR) techniques of 31P inversion recovery and 1H →31P cross-polarization (CP) in a magnetic field of 11.7 T using magic angle spinning (MAS) at a high spinning rate of 19 and 28 kHz, respectively. These NMR results suggest that most of HLP molecules strongly interact with nanocrystals through coordination bonds and/or hydrogen bonds

  6. Trend estimates of AERONET-observed and model-simulated AOTs between 1993 and 2013

    Science.gov (United States)

    Yoon, J.; Pozzer, A.; Chang, D. Y.; Lelieveld, J.; Kim, J.; Kim, M.; Lee, Y. G.; Koo, J.-H.; Lee, J.; Moon, K. J.

    2016-01-01

    Recently, temporal changes in Aerosol Optical Thickness (AOT) have been investigated based on model simulations, satellite and ground-based observations. Most AOT trend studies used monthly or annual arithmetic means that discard details of the generally right-skewed AOT distributions. Potentially, such results can be biased by extreme values (including outliers). This study additionally uses percentiles (i.e., the lowest 5%, 25%, 50%, 75% and 95% of the monthly cumulative distributions fitted to Aerosol Robotic Network (AERONET)-observed and ECHAM/MESSy Atmospheric Chemistry (EMAC)-model simulated AOTs) that are less affected by outliers caused by measurement error, cloud contamination and occasional extreme aerosol events. Since the limited statistical representativeness of monthly percentiles and means can lead to bias, this study adopts the number of observations as a weighting factor, which improves the statistical robustness of trend estimates. By analyzing the aerosol composition of AERONET-observed and EMAC-simulated AOTs in selected regions of interest, we distinguish the dominant aerosol types and investigate the causes of regional AOT trends. The simulated and observed trends are generally consistent with a high correlation coefficient (R = 0.89) and small bias (slope±2σ = 0.75 ± 0.19). A significant decrease in EMAC-decomposed AOTs by water-soluble compounds and black carbon is found over the USA and the EU due to environmental regulation. In particular, a clear reversal in the AERONET AOT trend percentiles is found over the USA, probably related to the AOT diurnal cycle and the frequency of wildfires. In most of the selected regions of interest, EMAC-simulated trends are mainly attributed to the significant changes of the dominant aerosols; e.g., significant decrease in sea salt and water soluble compounds over Central America, increase in dust over Northern Africa and Middle East, and decrease in black carbon and organic carbon over Australia.

  7. Changes in the bending modulus of AOT based microemulsions induced by the incorporation of polymers in the water core.

    Science.gov (United States)

    Kuttich, Björn; Grefe, Ann-Kathrin; Stühn, Bernd

    2016-08-14

    The bending modulus κ is known to be a crucial parameter for the stability of the droplet phase in microemulsion systems. For AOT based water in oil microemulsions the bending modulus of the surfactant has values close to kBT but can be influenced by the presence of polymers. In this work we focus on the water soluble polymer polyethylene glycol and how it influences the bending modulus. An increase by a factor of three is found. For the correct evaluation of the bending modulus via percolation temperatures and droplet radii, thus by dielectric spectroscopy and small angle X-ray scattering, the determination of the radii right at the percolation temperature is crucial as we will show, although it is often neglected. In order to precisely determine the droplet radii we will present a global fitting model which provides reliable results with a minimum number of free fitting parameters. PMID:27416768

  8. FT-IR studies on the conformation and effective head-group area of AOT molecules in W/O microemulsions

    Institute of Scientific and Technical Information of China (English)

    周国伟; 鲍猛; 李干佐; 陈文君

    2002-01-01

    Using Fourier transform infrared(FT-IR) spectroscopy technique, the carbonyl stretching vibration bands of AOT in sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/isooctane/water reverse (W/O) microemulsions system have been investigated by least square curve fitting. The results indicate that an asymmetric adsorbed peak of carbonyl stretching vibration of AOT molecule is situated in (1739 ± 1) and (1725 ± 2) cm-1. The two peaks correspond to different carbonyls in gauche conformation and trans conformation of AOT molecules, respectively. With different water contents (W0), the variations of peak intensity ratio (/= l1739/l1725) reflect the change of the ratio for the two conformation populations and the variations of the effective head-group area of AOT molecule have relations to the ratio of two conformation populations.

  9. Photoisomerization and reorientational mobility of symmetric carbocyanines in AOT/alkane/polar solvent microemulsions

    Science.gov (United States)

    Dandapat, Manika; Basu, Saswati; Ghosh, Deborin; Mandal, Debabrata

    2014-07-01

    Molecular motion of carbocyanine fluorophores DOCI, DODCI and DTDCI were studied in AOT/n-heptane microemulsions containing added polar solvents: water, methanol or acetonitrile. The response varied remarkably depending on the nature of the fluorophore and polar solvent. When the amount of added polar solvent was low, molecular mobility was invariably retarded, due to a combination of electrostatic and hydrophobic forces that induce the guest fluorophore to cling to the AOT molecules of the host reverse micelle. However, at high amounts of added methanol or water, these interactions diminished considerably, causing increase in the mobility of the guest fluorophores up to different extents.

  10. A small-angle neutron scattering study of intermicellar interactions in microemulsions of AOT, water, and near-critical propane

    International Nuclear Information System (INIS)

    Small-angle neutron scattering (SANS) measurements of high-pressure solutions of propane/sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/D2O have demonstrated that a water-in-oil microemulsion phase can be formed in propane. The dispersed droplets are, within experimental error, the same size as those formed in conventional microemulsions at the same water-to-surfactant ratio, and the size does not depend on propane density. The interdroplet interaction potential was modeled as a hard-core repulsion augmented by a strong and extremely short range attraction. This model describes droplets whose hydrocarbon tails are strongly attractive to the hydrocarbon tails of adjacent droplets. The SANS fit shows that the magnitude of the tail-tail attractive interactions may be much stronger than the longer range van der Waals type attractive interactions between the water cores of the droplets. These findings confirm results of IR and UV-vis spectroscopic studies of near-critical and supercritical fluid microemulsions

  11. USPIO assisting degradation of MXC by host/guest-type immobilized laccase in AOT reverse micelle system.

    Science.gov (United States)

    Yang, Yu-Xiang; Pi, Na; Zhang, Jian-Bo; Huang, Yan; Yao, Ping-Ping; Xi, Yan-Jie; Yuan, Hong-Ming

    2016-07-01

    The laccase and ultrasmall superparamagnetic iron oxide nanoparticles (USPIO) have been assembled inside the tubular mesoporous silica via co-adsorption technology to prepare host/guest-type immobilized laccase, which is applied to degrade methoxychlor (MXC) in aqueous and reverse micelle environments. The effects of various parameters on degradation of MXC were studied. Under the optimum conditions, the degradation rate could reach maximum value of 45.6 % and remain at 20.8 % after seven cycles. Moreover, the addition of small molecular compound 2, 2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) to the system could greatly improve the degradation efficiency. The MXC degradation process is a first-order reaction, and the activation energy of MXC degradation catalyzed by immobilized laccase (41.46 kJ mol(-1)) is relatively lower than that catalyzed by free laccase (44.91 kJ mol(-1)). Based on the degradation products measured by gas chromatograph-mass spectrometer (GC-MS) and nuclear magnetic resonance (NMR), the degradation mechanism of MXC has also been proposed. PMID:27023821

  12. Ramping of pH Across the Water-Pool of a Reverse Micelle.

    Science.gov (United States)

    Mukherjee, Puspal; Gupta, Shradhey; Rafiq, Shahnawaz; Yadav, Rajeev; Jain, Vipin Kumar; Raval, Jayraj; Sen, Pratik

    2016-02-23

    In this work, we have addressed the problem of "acidity" of the water-pool of a reverse micelle (RM) through the well-known inversion of sucrose reaction as a tool of investigation. This reaction has been performed inside positively and negatively charged RM and the rates are compared with that in bulk water. We propose that the buffer-like action in a water-pool is much stronger than expected earlier. The rate of sucrose hydrolysis slowed down in the negatively charged AOT reverse micelle while it sped up for the positively charged CTAB reverse micelle. However, temperature-dependent measurements showed that the activation energy remained the same for all the cases. It has been concluded that a proton gradient exists inside the water-pool of the reverse micelle and it determines the buffer-like action of the water-pool that persists until about 2 N of HCl in AOT RM of w0 = 10.5. PMID:26854978

  13. Factors Affecting Trypsin Extraction by AOT Reversed Micelles and Observation by STM%AOT反胶束萃取胰蛋白酶的STM及主要影响因素

    Institute of Scientific and Technical Information of China (English)

    周小华; 翁亚军

    2006-01-01

    In this article, the influence factors of trypsin extracted from crude pancreatin was investigated, and scanning tunneling microscope(STM) was used to observe the image of trypsin in butane-diacid-2-ethyl-hexyl-ester-sulfonic sodium (AOT)/iso-octane reversed micelles. The STM image showed that trypsins bounded in reversed micelles was rigid, which weakened its conjugative effect and caused maximum ultraviolet absorption and fluorescence emissive absorption moving toward blue waves. AOT concentration, pH and cations were the main influence factors of extraction. Specifically, extraction percentage of trypsin decreased with the increase of AOT concentration from 0.01 to 0.1mol·L-1. When pH value is from 5.30 to 10.0, i.e. less than pI of trypsin, the extraction percentage is raised with the different increase of pI-pH, but when the pH value is less than 5.20, the extraction percentage is decreased with the acidity added. Besides, the extraction efficiency is negative, related with the concentrations of Ca2+, Na+,K+ which were in the range of 0.2-1.0mol· L-1, and influence of concentration of Ca2+ is greater than that of Na+, and K+ which has the minimum impact with the same concentration. Finally, optimum conditions to extract trypsin were: AOT reversed micelles 0.05mol·L-1, trypsin concentration in crude pancreatin solution 3mg·ml-1, pH 5.2- 5.3, ratio (by volume) of extraction phase to strip-extraction phase 1:1, and time of 5min. The corresponding percentage of extraction was 22.7% and specific activity was 78.9 N-benzoyl-L-arginine ethyl ester (BAEE) U·mg-1 protein, three times than that in crude pancreatin. There was no lipase and amylopsin activity was decreased to 1/5 of crude pancreatin. Partly purifying solution was treated by condition mentioned above with 0.05mol·L-1 ceryl-trimethyl-ammonium bromide (CTAB), total extraction percentage of trypsin was 74.18% and specific activity was 3148.3 BAEE U·mg-1, i.e. 48.16 times purer than that in crude

  14. Modulation of dynamics and reactivity of water in reverse micelles of mixed surfactants.

    Science.gov (United States)

    Mitra, Rajib Kumar; Sinha, Sudarson Sekhar; Verma, Pramod Kumar; Pal, Samir Kumar

    2008-10-16

    In this contribution, we attempt to correlate the change in water dynamics in a reverse micellar (RM) core caused by the modification of the interface by mixing an anionic surfactant, sodium bis(2-ethylhexyl) sulfosuccinate (AOT), and a nonionic surfactant, tetraethylene glycol monododecyl ether (Brij-30), at different proportions, and its consequent effect on the reactivity of water, measured by monitoring the solvolysis reaction of benzoyl chloride (BzCl). The dimension of the RM droplets at different mixing ratios of AOT and Brij-30 (X(Brij-30)) has been measured using dynamic light scattering (DLS) technique. The physical properties of the RM water have been determined using Fourier transform infrared spectroscopy (FTIR) and compressibility studies, which show that with increasing X(Brij-30), the water properties tend toward that of bulk-like water. The solvation dynamics, probed by coumarin 500 dye, gets faster with X(Brij-30). The rotational anisotropy studies along with a wobbling-in-cone analysis show that the probe experiences less restriction at higher X(Brij-30). The kinetics of the water-mediated solvolysis also gets faster with X(Brij-30). The increased rate of solvolysis has been correlated with the accelerated solvation dynamics, which is another consequence of surfactant headgroup-water interaction. PMID:18808089

  15. Temperature control of pattern formation in the Ru(bpy)(3)(2+)-catalyzed BZ-AOT system.

    Science.gov (United States)

    McIlwaine, Rachel; Vanag, Vladimir K; Epstein, Irving R

    2009-03-14

    Using temperature as a control parameter, we observe a transition from stationary Turing patterns at T = 15-20 degrees C to traveling waves at T = 50 degrees C (and above) in the Ru(bpy)(3)(2+)-catalyzed Belousov-Zhabotinsky (BZ) reaction incorporated into the water nanodroplets of a water-in-oil aerosol OT (AOT) microemulsion. At constant chemical composition, molar ratio and droplet fraction, the transition takes place via a series of stable patterns, including oscillatory Turing patterns (at 35-40 degrees C) and reversed oscillatory Turing patterns (at 50 degrees C). We attribute the pattern transitions to a temperature-induced percolation transition of the BZ-AOT microemulsion, implying a change from isolated water nanodroplets to a system-spanning network of water channels. PMID:19240935

  16. Rotating Reverse-Osmosis for Water Purification

    Science.gov (United States)

    Lueptow, RIchard M.

    2004-01-01

    A new design for a water-filtering device combines rotating filtration with reverse osmosis to create a rotating reverse- osmosis system. Rotating filtration has been used for separating plasma from whole blood, while reverse osmosis has been used in purification of water and in some chemical processes. Reverse- osmosis membranes are vulnerable to concentration polarization a type of fouling in which the chemicals meant not to pass through the reverse-osmosis membranes accumulate very near the surfaces of the membranes. The combination of rotating filtration and reverse osmosis is intended to prevent concentration polarization and thereby increase the desired flux of filtered water while decreasing the likelihood of passage of undesired chemical species through the filter. Devices based on this concept could be useful in a variety of commercial applications, including purification and desalination of drinking water, purification of pharmaceutical process water, treatment of household and industrial wastewater, and treatment of industrial process water. A rotating filter consists of a cylindrical porous microfilter rotating within a stationary concentric cylindrical outer shell (see figure). The aqueous suspension enters one end of the annulus between the inner and outer cylinders. Filtrate passes through the rotating cylindrical microfilter and is removed via a hollow shaft. The concentrated suspension is removed at the end of the annulus opposite the end where the suspension entered.

  17. Absorption Complex between Porphyrin and Phenothiazine in Reverse Micelles

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The interaction between amphiphilic porphyrin and phenothiazine in AOT/isooctane/ water reverse micelle was investigated by UV-Vis spectra. A new absorption complex between the two species is formed in such circumstances, which is ascribed to the enrichment of the components by the reverse micelle. The fluorescence quenching of CHTTP by PTH becomes more efficient after the formation of the absorption complex.

  18. The influence of charge on the structure and dynamics of water encapsulated in reverse micelles.

    Science.gov (United States)

    Patra, Animesh; Luong, Trung Quan; Mitra, Rajib Kumar; Havenith, Martina

    2014-07-01

    Hydrogen-bonded structure and relaxation dynamics of water entrapped inside reverse micelles (RMs) composed of surfactants with different charged head groups: sodium bis(2-ethylhexyl) sulfosuccinate (AOT) (anionic), didodecyldimethylammonium bromide (DDAB) (cationic) and Igepal CO-520 (Igepal) (nonionic) in cyclohexane (Cy) have been studied as a function of hydration (defined by ). Sub-diffusive slow (sub-ns) relaxation dynamics of water has been measured by the time resolved fluorescence spectroscopy (TRFS) technique using two fluorophores, namely 8-anilino-1-naphthalenesulfonic acid (ANS) and coumarin-343 (C-343). The hydrogen bonded connectivity network of water confined in these RMs has been investigated by monitoring the hydrogen bond stretching and libration bands of water using far-infrared FTIR spectroscopy. In addition, the ultrafast collective relaxation dynamics of water inside these RMs has been determined by dielectric relaxation in the THz region (0.2-2.0 THz) using THz time domain spectroscopy (THz-TDS). While TRFS measurements establish the retardation of water dynamics for all the RM systems, FTIR and THz-TDS measurements provide with signature of charge specificity. PMID:24848870

  19. Nanoparticles synthesis of tungsten disulfide via AOT-based microemulsions

    Energy Technology Data Exchange (ETDEWEB)

    Ghoreishi, S.M., E-mail: ghoreshi@cc.iut.ac.ir [Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Nanotechnology and Advanced Materials Institute, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Meshkat, S.S. [Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Department of Chemical Engineering, Urmia University of Technology, Urmia 57155-419 (Iran, Islamic Republic of); Ghiaci, M. [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Dadkhah, A.A. [Department of Chemical Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2012-06-15

    Graphical abstract: A controlled synthesis of WS2 nanoparticles (most probably inorganic fullerene (IF)) via microemulsion was applied for the first time to prepare WS2 (7–12 nm) by acidification of the water cores of the AOT reverse microemulsion. Highlights: ► An innovative reverse microemulsion technique was developed for WS{sub 2} synthesis. ► WS{sub 2} nanoparticles were obtained with narrow size distribution in range of 7–12 nm. ► Operating cost of microemulsion was lower in contrast to quartz reactor method. ► WS{sub 2} morphology could be controlled to obtain highly active and selective catalysts. ► Lower size of WS{sub 2} in this study overcomes the shortcoming of quartz reactor method. -- Abstract: The tungsten disulfide (WS{sub 2}) nanoparticles (most probably inorganic fullerene (IF)) with a narrow size distribution were synthesized by a reverse micelle technique for the first time. The particle size was controlled by varying water-to-surfactant molar ratio (W{sub 0}), aging time and reagent concentration. The synthesized WS{sub 2} nanoparticles were characterized by zetasizer, UV–visible spectrophotometers and transmission electron microscopy (TEM). The WS{sub 2} nanoparticles with particle diameter size of 7–12 nm were obtained via 24 h aging time. The particle size was controlled by changing the aging time and molar ratio of water/surfactant. Doubling W{sub 0} increased the amount and particle size of WS{sub 2} by 22 and 26%, respectively. The effect of aging time in the range of 6–24 h was investigated and the complete disappearance of yellowish color at 24 h resulted in an optically clear solution, which was the indication of WS{sub 2} formation with 100% conversion of reactant ((NH{sub 4}){sub 2}WS{sub 4}) in the batch reactor.

  20. Nanoparticles synthesis of tungsten disulfide via AOT-based microemulsions

    International Nuclear Information System (INIS)

    Graphical abstract: A controlled synthesis of WS2 nanoparticles (most probably inorganic fullerene (IF)) via microemulsion was applied for the first time to prepare WS2 (7–12 nm) by acidification of the water cores of the AOT reverse microemulsion. Highlights: ► An innovative reverse microemulsion technique was developed for WS2 synthesis. ► WS2 nanoparticles were obtained with narrow size distribution in range of 7–12 nm. ► Operating cost of microemulsion was lower in contrast to quartz reactor method. ► WS2 morphology could be controlled to obtain highly active and selective catalysts. ► Lower size of WS2 in this study overcomes the shortcoming of quartz reactor method. -- Abstract: The tungsten disulfide (WS2) nanoparticles (most probably inorganic fullerene (IF)) with a narrow size distribution were synthesized by a reverse micelle technique for the first time. The particle size was controlled by varying water-to-surfactant molar ratio (W0), aging time and reagent concentration. The synthesized WS2 nanoparticles were characterized by zetasizer, UV–visible spectrophotometers and transmission electron microscopy (TEM). The WS2 nanoparticles with particle diameter size of 7–12 nm were obtained via 24 h aging time. The particle size was controlled by changing the aging time and molar ratio of water/surfactant. Doubling W0 increased the amount and particle size of WS2 by 22 and 26%, respectively. The effect of aging time in the range of 6–24 h was investigated and the complete disappearance of yellowish color at 24 h resulted in an optically clear solution, which was the indication of WS2 formation with 100% conversion of reactant ((NH4)2WS4) in the batch reactor.

  1. Phase behavior of supercritical CO2 microemulsion with food-grade surfactant AOT

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yongsheng; AN Xueqin; SHEN Weiguo; ZHANG Yinghua

    2006-01-01

    Phase behavior of scCO2 microemulsion formed with food grade surfactant sodium bis-(2-ethylhexyl) sulfosuccinate (AOT) was studied. Critical microemulsion concentration (cμc) was deduced from the dependence of pressure of cloud points on the concentration of surfactant AOT at constant temperature and water concentration. The results show that there are transition points on the cloud point curve in a very narrow range of concentration of surfactant AOT. The transition points were changed with the temperature and water concentration. These phenomena show that lower temperature is suitable to forming microemulsion droplet and the microemulsion with high water concentration is likely to absorb more surfactants to structure the interface.

  2. Ultrafast dynamics of water in cationic micelles.

    Science.gov (United States)

    Dokter, Adriaan M; Woutersen, Sander; Bakker, Huib J

    2007-03-28

    The effect of confinement on the dynamical properties of liquid water is investigated for water enclosed in cationic reverse micelles. The authors performed mid-infrared ultrafast pump-probe spectroscopy on the OH-stretch vibration of isotopically diluted HDO in D(2)O in cetyltrimethylammonium bromide (CTAB) reverse micelles of various sizes. The authors observe that the surfactant counterions are inhomogeneously distributed throughout the reverse micelle, and that regions of extreme salinity occur near the interfacial Stern layer. The authors find that the water molecules in the core of the micelles show similar orientational dynamics as bulk water, and that water molecules in the counterion-rich interfacial region are much less mobile. An explicit comparison is made with the dynamics of water confined in anionic sodium bis(2-ethythexyl) sulfosuccinate (AOT) reverse micelles. The authors find that interfacial water in cationic CTAB reverse micelles has a higher orientational mobility than water in anionic AOT reverse micelles. PMID:17411144

  3. Ultrafast dynamics of water in cationic micelles

    Science.gov (United States)

    Dokter, Adriaan M.; Woutersen, Sander; Bakker, Huib J.

    2007-03-01

    The effect of confinement on the dynamical properties of liquid water is investigated for water enclosed in cationic reverse micelles. The authors performed mid-infrared ultrafast pump-probe spectroscopy on the OH-stretch vibration of isotopically diluted HDO in D2O in cetyltrimethylammonium bromide (CTAB) reverse micelles of various sizes. The authors observe that the surfactant counterions are inhomogeneously distributed throughout the reverse micelle, and that regions of extreme salinity occur near the interfacial Stern layer. The authors find that the water molecules in the core of the micelles show similar orientational dynamics as bulk water, and that water molecules in the counterion-rich interfacial region are much less mobile. An explicit comparison is made with the dynamics of water confined in anionic sodium bis(2-ethythexyl) sulfosuccinate (AOT) reverse micelles. The authors find that interfacial water in cationic CTAB reverse micelles has a higher orientational mobility than water in anionic AOT reverse micelles.

  4. Reverse Osmosis in the Treatment of Drinking Water

    OpenAIRE

    Dupont, R. Ryan; Eisenberg, Talbert N.; Middlebrooks, E. Joe

    1982-01-01

    An extensive review of the literature was conducted and results were evaluated for the use of the reverse osmosis process in the treatment of drinking water supplies. All aspects of reverse osmosis technology, including pretreatment requirements; membrane type and configuration; membrane cleaning and maintenance; and reverse osmosis removal of organics, inorganics, and microbial contaminants were incorporated inot...

  5. Arsenic removal in drinking water by reverse osmosis

    OpenAIRE

    Ahmad, Md. Fayej

    2012-01-01

    Arsenic is widely distributed in nature in the air, water and soil. Acute and chronic arsenic exposure by drinking water has been reported in many countries, especially Argentina, Bangladesh, India, Mexico, Mongolia, Thailand and Taiwan. There are many techniques used to remove arsenic from drinking water. Among them reverse osmosis is widely used. Therefore the purpose of this study is to find the conditions favorable for removal of arsenic from drinking water by using reverse osmosis ...

  6. Treatment of contaminated waste water by reverse osmosis membrane

    International Nuclear Information System (INIS)

    This paper present the results obtained in treatment by reverse osmosis membrane of waste waters containing radioactive elements and other dissolved heavy or rare metals. Cellulose acetate reverse osmosis membranes were used for removal and recovery uranium from mine waters, pond waters and the other waste waters from ore processing. The flux permeate and rejection for solutes presented in solution were determined. The experiments were performed at laboratory scale. The operation conditions are described

  7. Complex permittivity of FeCl3/AOT/CCl4 microemulsions probed by AC impedance spectroscopy.

    Science.gov (United States)

    Calandra, Pietro; Ruggirello, Angela; Turco Liveri, Vincenzo

    2009-09-01

    The complex permittivity of FeCl(3)/AOT/CCl(4) microemulsions in the 1-10(5) Hz frequency range has been measured by the conventional AC complex impedance technique. Measurements as a function of the volume fraction of the dispersed phase (FeCl(3)+AOT) and temperature at fixed salt-to-AOT molar ratio (R, R = 0.5) show that the entrapment of FeCl(3) clusters significantly enhances the local permittivity of the AOT reverse micelles and the number density of charge carriers resulting from the peculiar state of the confined inorganic salt. An estimate of the apparent static permittivity of the FeCl(3) ionic clusters entrapped in the core of AOT reverse micelles gives the very high and quite surprisingly value of about 237. Moreover, a thorough analysis of conductivity data and of their temperature dependence strongly supports the hypothesis that the charge transport in these systems is mainly sustained by a mechanism of hopping consisting in the continuous jumping of charged species within supra-micellar aggregates of AOT reverse micelles whose aggregation is driven by fluctuating opposite charges on contacting micelles. PMID:19481764

  8. Correlation between AERONET AOT and VIIRS EDR AOT: A new EDR cell

    Science.gov (United States)

    Molinie, J.; Henry, J. L.; Clement, J.; Euphrasie-Clotilde, L.; Brute, F. N.

    2015-12-01

    Every year, a huge mass of desert dusts lifted from Saharan and sub Saharan regions is injected over the Atlantic Ocean and bring to the Caribbean and the American continent. Guadeloupe a West Indies island, is affected by the presence of dusts particles which impact the air quality and acts on human health. The effect produced by the particles in the atmosphere can be observed by satellite. VIIRS is one the latest tools provided by NASA, to help scientific community to have a better understanding of aerosol behavior. In this job we try to found a link between ground measurement AOT and VIIRS data.In Guadeloupe, AOT measurements have been performed with sun photometer of AERONET network. We calculated AOT at 500 nm mean daily sun photometer data in order to compare them with AOT EDR 550 data computed by NOAA Aerosol calibration and validation team. Three AOT EDR cells, located over the ocean and close to the East coast of the island of have been chosen to evaluate the correlation between ground and satellite data. We obtained using data performed from May to December 2012, correlation coefficient range between 0.8 and 0.87. We observed numerous AOT EDR 550 have been computed with a number of IP pixel, nAOT very low. We proposed to used only cases with nAOT equal or higher than 10. The correlation coefficients improved and reached 0.9. However, those good results have been obtained with a day number reduced by almost 50 per cent.In order to keep a good correlation and a higher number of day we rebuilt a cell by merging two cells. We obtained a new cell with an AOT EDR value equal to the mean AOT EDR of the two parents' value and a nAOT the sum of the previous nAOTs. The results with the new nAOT equal of higher than 10 is, r =0.91 and we keep 75 per cent of the cases.

  9. Vibrational energy relaxation of water in Aerosol OT reverse micelle

    Science.gov (United States)

    Pang, Yoonsoo; Deak, John; Dlott, Dana

    2005-03-01

    An IR-Raman technique with mid-IR pump and anti-Stokes Raman probe is used to investigate reverse micelle mixture of Aerosol OT, water, and carbon tetrachloride, where polar water phase and nonpolar oil phase is separated by a monolayer of surfactant molecules. Anti-Stokes Raman scattering is only dependent on the population of vibrationally excited states, thus time-dependent population changes of parent/daughter vibrations can be monitored with this technique. Vibrational energy from nanodroplet of water is transferred to the surfactant head group in 1.8 ps and then out to solvent in 10 ps. Vibrational energy directly pumped into the surfactant tail group results in a slower 20-40 ps energy transfer to solvent. This energy transfer cannot be explained by ordinary heat transfer, but the specific vibrational energy relaxation pathway such as sulfonate stretch of surfactant molecules should be used. We can change the water-to-solvent energy transfer rate by adopting different size of reverse micelles or changing pump frequency over the broad OH stretch mode of water due to hydrogen bond network. Water molecules confined in nanometer scale reverse micelles have very different properties from bulk water and we have found many differences between the vibrational dynamics of water in these reverse micelles and those of bulk water.

  10. Risk-based evaluation of Allowed Outage Times (AOTs) considering risk of shutdown

    International Nuclear Information System (INIS)

    When safety systems fail during power operation, Technical Specifications (TS) usually limit the repair within Allowed Outage Time (AOT). If the repair cannot be completed within the AOT, or no AOT is allowed, the plant is required to be shut down for the repair. However, if the capability to remove decay heat is degraded, shutting down the plant with the need to operate the affected decay-heat removal systems may impose a substantial risk compared to continued power operation over a usual repair time. Thus, defining a proper AOT in such situations can be considered as a risk-comparison between the repair in frill power state with a temporarily increased level of risk, and the altemative of shutting down the plant for the repair in zero power state with a specific associated risk. The methodology of the risk-comparison approach, with a due consideration of the shutdown risk, has been further developed and applied to the AOT considerations of residual heat removal and standby service water systems of a boiling water reactor (BWR) plant. Based on the completed work, several improvements to the TS requirements for the systems studied can be suggested

  11. Extraction of lysozyme, alpha-chymotrypsin, and pepsin into reverse micelles formed using an anionic surfactant, isooctane, and water.

    Science.gov (United States)

    Chang, Q; Liu, H; Chen, J

    1994-11-01

    The extraction of lysozyme, alpha-chymotrypsin, and pepsin from buffered salt solutions into reverse micelles was examined at different pH values and surfactant concentrations. The reverse micelles was formed by mixing aqueous buffer supplemented with KCl and an organic phase of isooctane(2,2,4-trimethylpentane), containing the anionic surfactant, Aerosol O. T. (dioctyl ester of sodium sulfosuccinic acid). The technique of dynamic laser scattering was used to measure the size of reverse micelles which were in equilibrium with the aqueous phase. It was found that the size of the reverse micelles decreased with increasing ionic strength but increased with increasing AOT concentration. In the process of extraction, the reverse micelles might have rearranged themselves to host the protein. The sizes of protein-filled and -unfilled reverse micelles were different, and an open equilibrium could be reached between them. Under the extraction conditions, only a small number of micelles were found to contain protein. PMID:7522474

  12. Treatment of produced waters by electrocoagulation and reverse osmosis

    Energy Technology Data Exchange (ETDEWEB)

    Tuggle, K.; Humenick, M.; Barker, F.

    1992-08-01

    Two oil field produced waters and one coal bed methane produced water from Wyoming were treated with electrocoagulation and reverse osmosis. All three produced waters would require treatment to meet the new Wyoming Department of Environmental Quality requirements for effluent discharge into a class III or IV stream. The removal of radium 226 and oil and grease was the primary focus of the study. Radium 226 and oil and grease were removed from the produced waters with electrocoagulation. The best removal of radium 226 (>84%) was achieved with use of a non-sacrificial anode (titanium). The best removal of oil and grease (>93%) was achieved using a sacrificial anode (aluminum). By comparison, reverse osmosis removed up to 87% of the total dissolved solids and up to 95% of the radium 226.

  13. REVERSE OSMOSIS FIELD TEST: TREATMENT OF WATTS NICKEL RINSE WATERS

    Science.gov (United States)

    A field test was conducted to determine the feasibility of using a polyamide reverse-osmosis membrane in hollow fine fiber configuration for closed-loop treatment of rinse water from a Watts-type nickel bath. Performance of the membrane module was determined by measuring the prod...

  14. Ultrafast vibrational dynamics of water confined in phospholipid reverse micelles

    Directory of Open Access Journals (Sweden)

    Elsaesser T.

    2013-03-01

    Full Text Available We study the ultrafast dynamics of OH stretching and bending vibrations of water inside dioleoylphosphatidylcholine (DOPC reverse micelles in a wide range of hydration. A strong hydration level dependence for the spectral diffusion rates is found and explained by the distinctly different environment for single water molecules bound to the anionic phosphate group. We show that the energy relaxation pathway of the OH stretching vibration at low hydration level involves the OH bending.

  15. Synthesis of nanocrystalline iron oxide by reverse micelle technique and its characterization

    International Nuclear Information System (INIS)

    Full text: Nanoparticles of Iron Oxide (Fe3O4) were synthesized in reverse micellar solutions. We used water-in-oil microemulsions consisting of water, twin tailed anionic bis (2-ethylhexyl) sodium sulfosuccinate (AOT) as a surfactant in isooctane (oil). Aqueous reactant FeSO4 and appropriate amount of Ammonium hydroxide were poured in the two microemulsions. All the steps of procedure carried out under the Argon atmosphere. The final precipitate was dried under vacuum condition. Reverse micelle route provides excellent control over particle size and particle shape. We studied the effect of Water/AOT ratio (w parameter) on controlling the particle size. The pure phase of magnetite (Fe3O4) was confirmed by X-Ray diffraction. The size of the prepared particles were determined by X-Ray and finally by SEM resulting in about 10 nm. Magnetic measurements carried out using VSM magnetometer. (authors)

  16. Reverse osmosis membrane of high urea rejection properties. [water purification

    Science.gov (United States)

    Johnson, C. C.; Wydeven, T. J. (Inventor)

    1980-01-01

    Polymeric membranes suitable for use in reverse osmosis water purification because of their high urea and salt rejection properties are prepared by generating a plasma of an unsaturated hydrocarbon monomer and nitrogen gas from an electrical source. A polymeric membrane is formed by depositing a polymer of the unsaturated monomer from the plasma onto a substrate, so that nitrogen from the nitrogen gas is incorporated within the polymer in a chemically combined form.

  17. Microstructure determination of AOT + phenol organogels utilizing small-angle X-ray scattering and atomic force microscopy.

    Science.gov (United States)

    Simmons, B A; Taylor, C E; Landis, F A; John, V T; McPherson, G L; Schwartz, D K; Moore, R

    2001-03-14

    Dry reverse micelles of the anionic twin-tailed surfactant bis(2-ethylhexyl) sulfosuccinate (AOT) dissolved in nonpolar solvents spontaneously form an organogel when p-chlorophenol is added in a 1:1 AOT:phenol molar ratio. The solvents used were benzene, toluene, m-xylene, 2,2,4-trimethylpentane (isooctane), decane, dodecane, tetradecane, hexadecane, and 2,6,10,14-tetramethylpentadecane (TMPD). The proposed microstructure of the gel is based on strands of stacked phenols linked to AOT through hydrogen bonding. Small-angle X-ray scattering (SAXS) spectra of the organogels suggest a characteristic length scale for these phenol-AOT strands that is independent of concentration but dependent on the chemical nature of the nonpolar solvent used. Correlation lengths determined from the SAXS spectra indicate that the strands self-assemble into fibers. Direct visualization of the gel in its native state is accomplished by using tapping mode atomic force microscopy (AFM). It is shown that these organogels consist of fiber bundle assemblies. The SAXS and AFM data reinforce the theory of a molecular architecture consisting of three length scales-AOT/phenolic strands (ca. 2 nm in diameter) that self-assemble into fibers (ca. 10 nm in diameter), which then aggregate into fiber bundles (ca. 20-100 nm in diameter) and form the organogel. PMID:11456891

  18. Sand Filter for Rainfall Water with Reverse Flow

    Directory of Open Access Journals (Sweden)

    Hilton Ruoso Junior

    2010-04-01

    Full Text Available The use of drinking water in activities that require no potable water is a waste of resources that could be avoided by using clean water, as the rainfall water. This procedure saves the amount spend on toilet discharges in washing cars, sidewalks, clothes and general irrigation as well as on the reduction of floods, helping to minimize environmental impacts on urban areas. This work aims to design, develop and test a sand filter to retain solid waste material from the rain water, allowing the improvement of their quality. The experimental work was developed in the laboratory of Environmental Engineering at the “Centro Universitário Franciscano”, using sand as a filter for a water reservoir of 250 liters, with filter materials such as gravel, sand, and geotextil and a electrical water-pump to test the system of reverse flow. By the results obtained the maximum flow filtration rate estimated is 11,800 L h-1. The filter controls 100% of particles larger than 0.15 mm. Filtered water in 75% of particles not removed by the filter has diameter less than 0.075 mm. The filter also provides efficiency of 79.12% in the removal of turbidity, 77.04% of color, electrical conductivity and 55.86% in 85.96% of total solids.

  19. A small angle neutron scattering study on the mixtures of pluronic L121 and anionic surfactant AOT

    Indian Academy of Sciences (India)

    G Ghosh; V K Aswal; D Varade

    2008-11-01

    Small angle neutron scattering (SANS) experiments have been carried out on the micellar solutions containing mixtures of a hydrophobic triblock copolymer (L121, EO5PO68EO5) and a hydrophobic anionic surfactant (AOT, sodium bis(2-ethylhexyl)sulphosuccinate) in water with varying ratio () of AOT to L121 for = 0.15, 0.2, 0.3, 0.5 and 0.6. It is known that either L121 or AOT alone forms vesicles in water, but in the mixture with appropriate ratio of the two components a thermodynamically stable, isotropic solution of apparently small micelle-like aggregates is formed. We find that these micelles are prolate ellipsoidal.

  20. AOT-based microemulsions accelerate the 1,3-cycloaddition of benzonitrile oxide to N-ethylmaleimide

    NARCIS (Netherlands)

    Engberts, J. B. F. N.; Fernandez, E.; Garcia-Rio, L.; Leis, J. R.

    2006-01-01

    We studied the 1,3-dipolar cycloaddition of benzonitrile oxide to N-ethylmaleimide in AOT/isooctane/water microemulsions at 25.0 degrees C and found the reaction rate to be roughly 150 and 35 times greater than that in isooctane and pure water, respectively. The accelerating effect of the microemuls

  1. A Well Water Reverse Osmosis Desalination Unit Diagnosis

    International Nuclear Information System (INIS)

    In this present work the diagnosis results of a reverse osmosis desalination unit are reported. Since 1997, the desalination unit was supplying a 1200 bed hotel. The feed water was driven from a well situated 300 m away form the sea. The water has an approximate salinity of 6gg.L-1. The unit was producing 600 m3 per day of desalinated water with a Total Dissolved Salts (TDS) of nearly 400 mg.L-1. The desalination unit has two stages with 67 pour cent and 42 pour cent yields respectively giving an average yield of 81 pour cent. The behavior of all water streams with respect to aggressiveness and scaling tendency was assessed. The 2nd stage reject water was shown to exhibit a very high scaling behavior with an instantaneous precipitation in the absence of feed water chemical treatment. The analyses have shown that the produced water was very aggressive. The second stage module autopsy has revealed a sharp decrease of the membrane performances because of mineral as well as organic fooling buildup. The inorganic scale was essentially made of coesite and calcite and kaolinite clay. The presence of silica and clay could be attributed to an inadequate filtration pre-treatment process that was not able to retain all the suspended matter in the feed water. Whereas the presence calcite crystals at the membrane surface, reveals that the chemical inhibition performed at the pre-treatment process without adjusting the water pH was not able to prevent calcium carbonate precipitation. A periodic acid wash of the 2nd stage membranes is then necessary to guarantee this stage desired objectives.

  2. A synthesis of AOT40-based response functions and critical levels of ozone for agricultural and horticultural crops

    Science.gov (United States)

    Mills, G.; Buse, A.; Gimeno, B.; Bermejo, V.; Holland, M.; Emberson, L.; Pleijel, H.

    Crop-response data from over 700 published papers and conference proceedings have been analysed with the aim of establishing ozone dose-response functions for a wide range of European agricultural and horticultural crops. Data that met rigorous selection criteria (e.g. field-based, ozone concentrations within European range, full season exposure period) were used to derive AOT40-yield response functions for 19 crops by first converting the published ozone concentration data into AOT40 (AOT40 is the hourly mean ozone concentration accumulated over a threshold ozone concentration of 40 ppb during daylight hours, units ppm h). For any individual crop, there were no significant differences in the linear response functions derived for experiments conducted in the USA or Europe, or for individual cultivars. Three statistically independent groups were identified: ozone sensitive crops (wheat, water melon, pulses, cotton, turnip, tomato, onion, soybean and lettuce); moderately sensitive crops (sugar beet, potato, oilseed rape, tobacco, rice, maize, grape and broccoli) and ozone resistant (barley and fruit represented by plum and strawberry). Critical levels of a 3 month AOT40 of 3 ppm h and a 3.5 month AOT40 of 6 ppm h were derived from the functions for wheat and tomato, respectively.

  3. AOT-microemulsions-based formation and evolution of PbWO$_{4}$ crystals

    CERN Document Server

    Chen, D; Tang Kai Bin; Liang Zhen Hua; Zheng Hua Gui

    2004-01-01

    Anionic surfactant-AOT-microemulsions-assisted formation and evolution of PbWO//4 nanostructures with bundles rodlike, ellipsoidlike, and spherelike prepared at different media conditions were studied by powder X-ray diffraction pattern, field emission scanning electron microscopy, and transmission electron microscopy. The possible mechanisms for the formation of PbWO//4 samples in series of microemulsion systems were discussed. Various comparison experiments show that several experimental parameters, such as the AOT concentration, the water content, and reaction temperature play important roles in the morphological control of PbWO//4 nanostructures. Room-temperature photoluminescence of PbWO//4 samples with different morphologies has also been investigated and the results reveal that all these samples showed similar features with emissions at 480 similar to 510 nm but different luminescence intensity. 40 Refs.

  4. Startling temperature effect on proteins when confined: single molecular level behaviour of human serum albumin in a reverse micelle.

    Science.gov (United States)

    Sengupta, Bhaswati; Yadav, Rajeev; Sen, Pratik

    2016-06-01

    The present work reports the effect of confinement, and temperature therein, on the conformational fluctuation dynamics of domain-I of human serum albumin (HSA) by fluorescence correlation spectroscopy (FCS). The water-pool of a sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reverse micelle has been used as the confined environment. It was observed that the conformational fluctuation time is about 6 times smaller compared to bulk medium when confined in a water-pool of 3.5 nm radius. On increasing the size of the water-pool the conformational fluctuation time was found to increase monotonically and approaches the bulk value. The effect of confinement is on par with the general belief about the restricted motion of a macromolecule upon confinement. However, the effect of temperature was found to be surprising. An increase in the temperature from 298 K to 313 K induces a larger change in the conformational fluctuation time in HSA, when confined. In the bulk medium, apparently there is no change in the conformational fluctuation time in the aforementioned temperature range, whereas, when HSA is present in an AOT water-pool of radius 3.5 nm, about an 88% increase in the fluctuation time was observed. The observed prominent thermal effect on the conformational dynamics of domain-I of HSA in the water-pool of an AOT reverse micelle as compared to in the bulk medium was concluded to arise from the confined solvent effect. PMID:27166785

  5. MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

    Energy Technology Data Exchange (ETDEWEB)

    T.M. Whitworth; Liangxiong Li

    2002-09-15

    This report describes work performed during the second year of the project ''Modified reverse osmosis system for treatment of produced waters.'' We performed two series of reverse osmosis experiments using very thin bentonite clay membranes compacted to differing degrees. The first series of 10 experiments used NaCl solutions with membranes that ranged between 0.041 and 0.064mm in thickness. Our results showed compaction of such ultra-thin clay membranes to be problematic. The thickness of the membranes was exceeded by the dimensional variation in the machined experimental cell and this is believed to have resulted in local bypassing of the membrane with a resultant decrease in solute rejection efficiency. In two of the experiments, permeate flow was varied as a percentage of the total flow to investigate results of changing permeate flow on solute rejection. In one experiment, the permeate flow was varied between 2.4 and 10.3% of the total flow with no change in solute rejection. In another experiment, the permeate flow was varied between 24.6 and 52.5% of the total flow. In this experiment, the solute rejection rate decreased as the permeate occupied greater fractions of the total flow. This suggests a maximum solute rejection efficiency for these clay membranes for a permeate flow of between 10.3 and 24.6% of the total; flow. Solute rejection was found to decrease with increasing salt concentration and ranged between 62.9% and 19.7% for chloride and between 61.5 and 16.8% for sodium. Due to problems with the compaction procedure and potential membrane bypassing, these rejection rates are probably not the upper limit for NaCl rejection by bentonite membranes. The second series of four reverse osmosis experiments was conducted with a 0.057mm-thick bentonite membrane and dilutions of a produced water sample with an original TDS of 196,250 mg/l obtained from a facility near Loco Hill, New Mexico, operated by an independent. These experiments

  6. New functions for estimating AOT40 from ozone passive sampling

    Science.gov (United States)

    De Marco, Alessandra; Vitale, Marcello; Kilic, Umit; Serengil, Yusuf; Paoletti, Elena

    2014-10-01

    AOT40 is the present European standard to assess whether ozone (O3) pollution is a risk for vegetation, and is calculated by using hourly O3 concentrations from automatic devices, i.e. by active monitoring. Passive O3 monitoring is widespread in remote environments. The Loibl function estimates the mean daily O3 profile and thus hourly O3 concentrations, and has been proposed to calculate AOT40 from passive samplers. We investigated whether this function performs well in inhomogeneous terrains such as over the Italian country. Data from 75 active monitoring stations (28 rural and 47 suburban) were analysed over two years. AOT40 was calculated from hourly O3 data either measured by active measurements or estimated by the Loibl function applied to biweekly averages of active-measurement hourly data. The latter approach simulated the data obtained from passive monitoring, as two weeks is the usual exposure window of passive samplers. Residuals between AOT40 estimated by applying the Loibl function and AOT40 calculated from active monitoring ranged from +241% to -107%, suggesting that the Loibl function is inadequate to accurately predict AOT40 in Italy. New statistical models were built for both rural and suburban areas by using non-linear models and including predictors that can be easily measured at forest sites. The modelled AOT40 values strongly depended on physical predictors (latitude and longitude), alone or in combination with other predictors, such as seasonal cumulated ozone and elevation. These results suggest that multi-variate, non-linear regression models work better than the Loibl-based approach in estimating AOT40.

  7. MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

    Energy Technology Data Exchange (ETDEWEB)

    T.M. Whitworth; Liangxiong Li

    2002-09-15

    This report describes work performed during the first year of the project ''Modified Reverse Osmosis System for Treatment of Produced Waters.'' This research project has two objectives. The first objective is to test the use of clay membranes in the treatment of produced waters by reverse osmosis. The second objective is to test the ability of a system patented by the New Mexico Tech Research Foundation to remove salts from reverse osmosis waste streams as a solid. We performed 12 experiments using clay membranes in cross-flow experimental cells. We found that, due to dispersion in the porous frit used adjacent to the membrane, the concentration polarization layer seems to be completely (or nearly completely) destroyed at low flow rates. This observation suggests that clay membranes used with porous frit material many reach optimum rejection rates at lower pumping rates than required for use with synthetic membranes. The solute rejection efficiency decreases with increasing solution concentration. For the membranes and experiments reported here, the rejection efficiency ranged from 71% with 0.01 M NaCl solution down to 12% with 2.3 M NaCl solution. More compacted clay membranes will have higher rejection capabilities. The clay membranes used in our experiments were relatively thick (approximately 0.5 mm). The active layer of most synthetic membranes is only 0.04 {micro}m (0.00004 mm), approximately 1250 times thinner than the clay membranes used in these experiments. Yet clay membranes as thin as 12 {micro}m have been constructed (Fritz and Eady, 1985). Since Darcy's law states that the flow through a material of constant permeability is inversely proportional to it's the material's thickness, then, based on these experimental observations, a very thin clay membrane would be expected to have much higher flow rates than the ones used in these experiments. Future experiments will focus on testing very thin clay membranes. The

  8. REMOVAL OF CHLORINATED AND BROMINATED ALKANES FROM DRINKING WATER USING REVERSE OSMOSIS

    Science.gov (United States)

    Membrane use in water treatment has historically focused on desalination. With the development of new membrane materials, attention began to focus on reverse osmosis and pervaporation as alternatives to traditional water treatment processes. This paper addresses the use of reve...

  9. Biosensors with reversed micelle-enzyme sensitive membrane

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effect of reversed micelle on the conformation of enzyme was studied by sensor techniques. By means of measurement of the response current of GOD enzyme membrane electrode, the effects of enzyme embedded in AOT reversed micellar on GOD conformation and catalytic activity are discussed. The results show that the response current increased greatly with decreasing ratio of GOD/AOT, meaning that the catalytic activity and the conformation stability of enzyme were enhanced.

  10. Reverse osmosis using for water demineralization for supplying the NPP and TPP steam generators

    International Nuclear Information System (INIS)

    Paper analyzes the conditions affecting the efficiency of water reverse-osmosis demineralization for NPP and TPP steam generators and presents an example of efficient application of a membrane reverse-osmosis facility serving as the first stage of water demineralization at the Mosehnergo Joint-Stock Company heating and power plant no. 23 to feed boilers

  11. Preparation and Characterization of Nanosized Hydroxyapatite Particles in AOT Inverse Microemulsion

    Institute of Scientific and Technical Information of China (English)

    REN Wei; LI Shi-pu; WANG You-fa; CAO Xian-ying; CHEN Xiao-ming

    2004-01-01

    Nanosized particles of hydroxyapatite (HAP) were synthesized by reacting Ca(H2PO4)2*H2O solution complex with equimolar Ca(OH)2 saturated solution in sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane water-in-oil microemulsion.The formation of microemulsion strongly depended on water content w (w=[H2O]/[AOT] molar ratio) and concentration of surfactant and cosurfactant (1-octanol).By the variety of conductivity with w and the partial ternary phase diagram derived from a series of demarcation points,we set the basic component of microemulsions:[AOT]=0.1M(mol/dm3),[1-octanol]=0.1M and w=3-9.Dynamic light scattering (DLS),UV-visible absorbance,TEM analysis and X-ray diffraction were used to characterize the microemulsion,formation of particles and resulting HAP particles.At low water content(w<9),the water pool radius of the droplet in the Ca(H2PO4)2*H2O microemulsion lineally depended on w.The size of final HAP particles was strongly affected by water content w and reactant concentration.With increasing water content w from 3 to 9,the size of HAP particles increased from 10-20nm to 40-50 nm at reactant concentration [Ca(H2PO4)2*H2O]=12×10-3 mol/dm3.The resulting HAP particles were poorly crystallized and spherical in morphology.

  12. MODIFIED REVERSE OSMOSIS SYSTEM FOR TREATMENT OF PRODUCED WATERS

    Energy Technology Data Exchange (ETDEWEB)

    Robert L. Lee; Junghan Dong

    2004-06-03

    This final report of ''Modified Reverse Osmosis System for Treatment of Produced Water,'' DOE project No. DE-FC26-00BC15326 describes work performed in the third year of the project. Several good results were obtained, which are documented in this report. The compacted bentonite membranes were replaced by supported bentonite membranes, which exhibited the same salt rejection capability. Unfortunately, it also inherited the clay expansion problem due to water invasion into the interlayer spaces of the compacted bentonite membranes. We noted that the supported bentonite membrane developed in the project was the first of its kind reported in the literature. An {alpha}-alumina-supported MFI-type zeolite membrane synthesized by in-situ crystallization was fabricated and tested. Unlike the bentonite clay membranes, the zeolite membranes maintained stability and high salt rejection rate even for a highly saline solution. Actual produced brines from gas and oil fields were then tested. For gas fields producing brine, the 18,300 ppm TDS (total dissolved solids) in the produced brine was reduced to 3060 ppm, an 83.3% rejection rate of 15,240 ppm salt rejection. For oilfield brine, while the TDS was reduced from 181,600 ppm to 148,900 ppm, an 18% rejection rate of 32,700 ppm reduction, the zeolite membrane was stable. Preliminary results show the dissolved organics, mainly hydrocarbons, did not affect the salt rejection. However, the rejection of organics was inconclusive at this point. Finally, the by-product of this project, the {alpha}-alumina-supported Pt-Co/Na Y catalytic zeolite membrane was developed and demonstrated for overcoming the two-step limitation of nonoxidation methane (CH{sub 4}) conversion to higher hydrocarbons (C{sub 2+}) and hydrogen (H{sub 2}). Detailed experiments to obtain quantitative results of H{sub 2} generation for various conditions are now being conducted. Technology transfer efforts included five manuscripts submitted to

  13. Reversibility, Water-Mediated Switching, and Directed Cell Dynamics

    OpenAIRE

    J. C. Phillips

    2008-01-01

    Reversible switching of the complex network dynamics of proteins is mimicked in selected network glasses and compacted small carbohydrate molecules. Protein transitions occur on long time scales ~ us -ms, evocative of the exponentially large viscosities found in glass-forming supercooled liquids just above the glass transition; in searching for mechanisms for reversibly slowed "geared activation", Kauzmann was led from proteins to glasses. I show here that selected network glasses and small c...

  14. Reversible assembly of oppositely charged hairy colloids in water

    NARCIS (Netherlands)

    Spruijt, E.; Bakker, H.E.; Kodger, T.E.; Sprakel, J.H.B.; Stuart, M.A.C.; Gucht, van der J.

    2011-01-01

    We present an experimental study of the fully reversible assembly of oppositely charged colloidal particles in aqueous solutions. Our polystyrene colloids are charged by a grafted polyelectrolyte brush on their surface and stabilized at all salt concentrations by a neutral adsorbed polymer layer. Be

  15. Mixed reverse micelles facilitated downstream processing of lipase involving water-oil-water liquid emulsion membrane.

    Science.gov (United States)

    Bhowal, Saibal; Priyanka, B S; Rastogi, Navin K

    2014-01-01

    Our earlier work for the first time demonstrated that liquid emulsion membrane (LEM) containing reverse micelles could be successfully used for the downstream processing of lipase from Aspergillus niger. In the present work, we have attempted to increase the extraction and purification fold of lipase by using mixed reverse micelles (MRM) consisting of cationic and nonionic surfactants in LEM. It was basically prepared by addition of the internal aqueous phase solution to the organic phase followed by the redispersion of the emulsion in the feed phase containing enzyme, which resulted in globules of water-oil-water (WOW) emulsion for the extraction of lipase. The optimum conditions for maximum lipase recovery (100%) and purification fold (17.0-fold) were CTAB concentration 0.075 M, Tween 80 concentration 0.012 M, at stirring speed of 500 rpm, contact time 15 min, internal aqueous phase pH 7, feed pH 9, KCl concentration 1 M, NaCl concentration 0.1 M, and ratio of membrane emulsion to feed volume 1:1. Incorporation of the nonionic surfactant (e.g., Tween 80) resulted in remarkable improvement in the purification fold (3.1-17.0) of the lipase. LEM containing a mixture of nonionic and cationic surfactants can be successfully used for the enhancement in the activity recovery and purification fold during downstream processing of enzymes/proteins. PMID:24930827

  16. Social, Economical and Technical Evaluation of a reverse osmosis drinking water plant in the Stockholm Archipelago

    OpenAIRE

    Lindkvist, Jonas

    2007-01-01

    The drinking water plant in this case study is a combined groundwater and reverse osmosisplant in the Stockholm archipelago. The reverse osmosis purification step was added to theplant in 1995. This technique is relatively new in Sweden and there are possibilities for it tobecome a good complement to conventional drinking water treatment. The plant has used thistechnique for over 10 years with good results. It is therefore of great interest to evaluate anddocument it for the possibility to im...

  17. Sand Filter for Rainfall Water with Reverse Flow

    OpenAIRE

    Hilton Ruoso Junior; Pedro Daniel da Cunha Kemerich; Afranio Almir Righes

    2010-01-01

    The use of drinking water in activities that require no potable water is a waste of resources that could be avoided by using clean water, as the rainfall water. This procedure saves the amount spend on toilet discharges in washing cars, sidewalks, clothes and general irrigation as well as on the reduction of floods, helping to minimize environmental impacts on urban areas. This work aims to design, develop and test a sand filter to retain solid waste material from the rain water, allowing the...

  18. Operation, Modeling and Analysis of the Reverse Water Gas Shift Process

    Science.gov (United States)

    Whitlow, Jonathan E.

    2001-01-01

    The Reverse Water Gas Shift process is a candidate technology for water and oxygen production on Mars under the In-Situ Propellant Production project. This report focuses on the operation and analysis of the Reverse Water Gas Shift (RWGS) process, which has been constructed at Kennedy Space Center. A summary of results from the initial operation of the RWGS, process along with an analysis of these results is included in this report. In addition an evaluation of a material balance model developed from the work performed previously under the summer program is included along with recommendations for further experimental work.

  19. Sensory quality of drinking water produced by reverse osmosis membrane filtration followed by remineralisation

    NARCIS (Netherlands)

    Vingerhoeds, M.H.; Nijenhuis, M.A.; Ruepert, N.; Bredie, W.L.P.; Kremer, S.

    2016-01-01

    Membrane filtration of ground, surface, or sea water by reverse osmosis results in permeate, which is almost free from minerals. Minerals may be added afterwards, not only to comply with (legal) standards and to enhance chemical stability, but also to improve the taste of drinking water made from pe

  20. Time scales of supercooled water and implications for reversible polyamorphism

    Science.gov (United States)

    Limmer, David T.; Chandler, David

    2015-09-01

    Deeply supercooled water exhibits complex dynamics with large density fluctuations, ice coarsening and characteristic time scales extending from picoseconds to milliseconds. Here, we discuss implications of these time scales as they pertain to two-phase coexistence and to molecular simulations of supercooled water. Specifically, we argue that it is possible to discount liquid-liquid criticality because the time scales imply that correlation lengths for such behavior would be bounded by no more than a few nanometers. Similarly, it is possible to discount two-liquid coexistence because the time scales imply a bounded interfacial free energy that cannot grow in proportion to a macroscopic surface area. From time scales alone, therefore, we see that coexisting domains of differing density in supercooled water can be no more than nano-scale transient fluctuations.

  1. Development of an optochemical sensor for continuous reversible determination of nitrate in drinking water and ground water

    International Nuclear Information System (INIS)

    An optochemical sensor has been developed for continuous reversible determination of nitrate in drinking water and ground water. The sensor is based on the combination of the anion selective liquid ion exchanger Ni(II[bathophenanthroline]32+ with phenolsulfonephtalein dyes in a polyvinylchloride membrane. (orig.)

  2. Integration of Ultrafiltration and Reverse Osmosis on purification of brackish waters: optimization trials

    OpenAIRE

    Travesset Mezquita, Marc

    2012-01-01

    Ultrafiltration (UF), due to its reliability, robustness and stable quality of the water produced , offers technical advantages over conventional pretreatments such as sand filtration coupled with coagulation/flocculation or activated carbon. In this study, the real case of a prototype designed, commissioned and operated consisting of an advanced Ultrafiltration unit (DOW™ UF) followed by a Reverse Osmosis system (Filmtec ™ Reverse Osmosis elements) is evaluated. The work prese...

  3. Supported lipid bilayer membranes for water purification by reverse osmosis.

    Science.gov (United States)

    Kaufman, Yair; Berman, Amir; Freger, Viatcheslav

    2010-05-18

    Some biological plasma membranes pass water with a permeability and selectivity largely exceeding those of commercial membranes for water desalination using specialized trans-membrane proteins aquaporins. However, highly selective transport of water through aquaporins is usually driven by an osmotic rather mechanical pressure, which is not as attractive from the engineering point of view. The feasibility of adopting biomimetic membranes for water purification driven by a mechanical pressure, i.e., filtration is explored in this paper. Toward this goal, it is proposed to use a commercial nanofiltration (NF) membrane as a support for biomimetic lipid bilayer membranes to render them robust enough to withstand the required pressures. It is shown in this paper for the first time that by properly tuning molecular interactions supported phospholipid bilayers (SPB) can be prepared on a commercial NF membrane. The presence of SPB on the surface was verified and quantified by several spectroscopic and microscopic techniques, which showed morphology close to the desired one with very few defects. As an ultimate test it is shown that hydraulic permeability of the SPB supported on the NF membrane (NTR-7450) approaches the values deduced from the typical osmotic permeabilities of intact continuous bilayers. This permeability was unaffected by the trans-membrane flow of water and by repeatedly releasing and reapplying a 10 bar pressure. Along with a parallel demonstration that aquaporins could be incorporated in a similar bilayer on mica, this demonstrates the feasibility of the proposed approach. The prepared SPB structure may be used as a platform for preparing biomimetic filtration membranes with superior performance based on aquaporins. The concept of SPBs on permeable substrates of the present type may also be useful in the future for studying transport of various molecules through trans-membrane proteins. PMID:20099798

  4. Obtaining water with a high degree of purity by using reverse osmosis

    Directory of Open Access Journals (Sweden)

    Nicolae Chirilă

    2011-12-01

    Full Text Available In this paper, we used the method of reverse osmosis in order to obtain water with a high degree of purity. For this aim, we used the TKA 20-120ECO device. We completed physic-chemical determinations for the water of supply, as well as for the water obtained after the osmosis process. The results that we obtained are relevant and interesting.

  5. Adenomatoid Odontogenic Tumor (AOT) Originating in a Unicystic Ameloblastoma: A Case Report

    OpenAIRE

    Jivan, Vibha; Altini, Mario; Meer, Shabnum; Mahomed, Farzana

    2007-01-01

    The follicular variant of the adenomatoid odontogenic tumor (AOT) is thought to originate from the reduced enamel epithelium of the dental follicle. The origin of the extra-follicular variant however, remains less clear. This paper presents a case of an extra-follicular AOT, which we believe originated from the epithelial lining of a unicystic ameloblastoma, and reviews the literature. The available evidence seems to indicate that some extra-follicular AOTs might arise as secondary phenomena ...

  6. Reversible assembly of magnetized particles: Application to water-borne pathogen enumeration

    Science.gov (United States)

    Ramadan, Qasem

    2009-12-01

    Reversible assembly of magnetized particles and cells has been proposed and implemented. The approach is based on magnetized particles or magnetically labeled cell immobilization in an array of individual particle/cell for optical counting. The device has been tested for few types of magnetic particles and one water-borne pathogen: Giardia Lamblia. An individual particle immobilization efficiency of 92% was achieved.

  7. Experiences on sea water reverse osmosis plant at Anuvijay township, Kudankulam Nuclear Power Plant

    International Nuclear Information System (INIS)

    Sea water reverse Osmosis plant SWRO of KKNPP is located at Anuvijay township, Chettikulam, Tirunelveli District, Tamilnadu. The objective of SWRO is to produce 2400 M3 of potable quality water per day. This plant consists of four streams, each having a capacity of 25 M3/hr. Each stream is having 9 pressure tube in parallel and each pressure tube has 6 polyamide spiral wound membrane in series. (author)

  8. Doping silver nanoparticles in AOT lyotropic lamellarphases

    Institute of Scientific and Technical Information of China (English)

    CHEN; Xiao

    2001-01-01

    aerosol OT/water/oil system, J. Colloid Interface Sci., 1979, 70: 577-583.[15]Fontell, K., The structure of the lamellar liquid crystalline phase in serosol OT-water system, J. Colloid Interface Sci.,1973, 44: 318-329.[16]Kotlarchyk, M., Sheu, E. Y., Capel, M., Structural and dynamical transformations between neighboring dense microemulsion phases, Phys. Rev. A, 1992, 46: 928-939.[17]Antelmi, D. A., Kekicheff, P., Measurement of the compressibility modulus in a lyotropic lamellar phase stabilized by undulation forces, J. Phys. Chem. B, 1997, 101: 8169-8179.[18]Wang, W., Efrima, S., Regev, O., Directing silver nanoparticles into colloid-surfactant lyotropic lamellar systems, J. Phys.Chem. B, 1999, 103: 5613-5621.[19]Chidichimo, G., La Mesa, C., Ranieri, G. A. et al., NMR investigation of the lamellar mesophase occuring in the system aerosol OT-water, Mol. Cryst. Liq. Cryst., 1987, 150b: 221-236.[20]Callaghan, P. T., Soderman, O., Examination of the lamellar phase of aerosol OT/water using pulsed field gradient nuclear magnetic resonance, J. Phys. Chem., 1983, 87: 1737-744.

  9. High-resolution modelling of AOT40 and stomatal ozone uptake in wheat and grassland: A comparison between 2000 and the hot summer of 2003 in Switzerland

    International Nuclear Information System (INIS)

    The aim was to compare the ozone risk for agricultural crops in Switzerland during the hot and dry year 2003 with the more 'normal' situation in 2000. An improved version of the Ozone DEposition Model ODEM was used at a 2 x 2 km resolution. The distribution of the index AOT40 was compared with the accumulated stomatal ozone flux, AFst. Averaged AOT40 at 2 m and at canopy height was much higher in 2003 than in 2000, but inter-annual differences in AFst for wheat and grasslands were small due to the limiting effect of low soil water contents in 2003. AOT40 suggested larger potential yield losses in wheat in 2003, while using AFst with a threshold of 6 nmol m-2 s-1 (AFst6) yielded similar estimates for both years. The data show that modelling of AFst can be used to differentiate ozone risks between regions and years at a national scale. - A national-scale assessment based on stomatal ozone flux, but not on AOT40, revealed similar risks for crops in years with different climates and ozone levels

  10. Polymerization of o-Phenylenediamine Catalyzed by Hemeproteins Encapsulated in Reversed Micelle

    Institute of Scientific and Technical Information of China (English)

    YANG Yong; MAO Lu-yuan; LI Liu-zhu; LIU Xiao-guang; SHI Jun; CAO Shao-kui

    2004-01-01

    Hemeproteins encapsulated in reversed micelle formulated with di-2-ethylhexyl sulfosuccinate (AOT)was found to catalyze the polymerization of o-phenylenediamine (o-PDA) with hydrogen peroxide, whereas o-PDA catalyzed by hemeproteins dissolved in water could only form its trimers. As the nanostructural environment in reversed micelle acts as a certain orientation surrounding medium, it offers a strong electrostatic field that alters the reductive potential of Fe3+/Fe2+ (Em7) in the heme of hemeproteins and thus increases the catalytic activity of peroxidase accordingly. According to the results of UV-Vis, 1H NMR and FTIR, the polymer catalyzed by hemoglobin(Hb) in reversed micelle was presumed to be constructed of lines and trapeziforms alternatively.

  11. Pump reversing water turbine and simplified propeller water turbine; Pump gyakuten suisha kan`i propeller suisha

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-10

    As a result of the joint research with the Tokyo Electric Power Co., Meidensha Corp. delivered a pump reversing water turbine and a simplified propeller water turbine to the Ayato power plant. For the purpose of effectively using the water gate-discharged for maintained discharge, the equipment is aimed at reducing construction cost. Therefore, by looking at it from a different angle, the submerged pump reversing water turbine and the outdoor-type distribution panel switchgear were adopted, and no building is needed. 1) Submerged pump reversing water turbine: 223kW-8.062m-3.733m{sup 3}/s; 2) Simplified propeller water turbine: 447kW-7.905m-7.633m{sup 3}/s. As features, the power plant runs the main two turbines alternately at the time of maintained discharge throughout a year, aiming at prolonging the equipment life. The plant runs two turbines at the time of increased discharge, aiming at increasing the output to maximum. (NEDO)

  12. Optical Properties of Silica-Encapsulated ZnSe Nanocrystals Prepared with Water-in-Oil Microemulsions

    Science.gov (United States)

    Liu, Kang; Kim, Ji Hyeon; Park, Sang Joon

    2013-01-01

    Silica-encapsulated ZnSe nanocrystals (NCs) were prepared by a safe and simple synthesis method, utilizing a sodium bis (2-ethylhexyl) sulfosuccinate (AOT)/water/cyclohexane microemulsion system and characterized by UV-vis analysis, photoluminescence (PL) spectroscopy, and transmission electron microscopy (TEM). For the encapsulations, two reverse micellar solutions [one for tetraethyl orthosilicate (TEOS) and the other for ZnSe] containing different water volumes were employed. The size of silica particles containing ZnSe NCs could be controlled from 13-37 nm by varying the water content W (W=[H2O]/[AOT]). On the other hand, the size of encapsulated ZnSe NCs was almost unchanged (about 2.5 nm) even though the size of the silica particles was increased. At W = 7, the maximum PL efficiency of 6% was obtained and the photostability was increased markedly after ZnSe NCs were encapsulated by silica.

  13. Rejection of Emerging Organic Contaminants by Nanofiltration and Reverse Osmosis Membranes: Effects of Fouling, Modelling and Water Reuse

    NARCIS (Netherlands)

    Yangali Quintanilla, V.

    2010-01-01

    The book contains a description of the presence of micropollutants (medicines, hormones, pesticides) in surface water and shows that conventional water treatment poorly removes micropollutants. Nanofiltration and reverse osmosis are more appropriate technologies; however removals can vary depending

  14. CTAB/water/chloroform reverse micelles: a closed or open association model?

    Science.gov (United States)

    Klíčová, L'ubica; Sebej, Peter; Štacko, Peter; Filippov, Sergey K; Bogomolova, Anna; Padilla, Marc; Klán, Petr

    2012-10-30

    The micellization of cetyltrimethylammonium bromide (CTAB) in chloroform in the presence of water was examined. Three scenarios of the reverse micelle formation, the closed, open and Eicke's association models, were considered in the interpretation of the experimental data. The growth of the aggregates was observed through the changes of NMR signals of associated water, probing the microenvironment of the premicellar aggregates and the interior of reverse micelles. This technique if combined with isothermal titration calorimetry (ITC) revealed that hydrated surfactant premicellar aggregates are already present at ∼6 mM CTAB. NMR, ITC and conductometry were used to determine the critical micelle concentration (cmc) to be ∼40 mM CTAB. It is suggested that the variation of the cmc values reflects the fact that the NMR analysis indicated the beginning of the reverse micelle formation, whereas conductometry and ITC measurements provided the upper limit and an average value of a so-called apparent cmc, respectively. The cmc values were found to be unaffected by the water content. The presence of reverse micelles, the existence of multiple equilibria, and high polydispersity of the samples were evidenced by DOSY NMR spectroscopy. As a result, we validated Eicke's association model, according to which cyclic inverse micelles are formed by a structural reorganization of linear associates within a narrow concentration range, called the apparent cmc. New experimental results have also been gained for micellization of cetyltrimethylammonium chloride (CTAC) in chloroform in the presence of water; a similar mechanism of reverse micelle formation has been suggested. PMID:23072317

  15. Effect of water matrices on removal of veterinary pharmaceuticals by nanofiltration and reverse osmosis membranes

    Institute of Scientific and Technical Information of China (English)

    Davor Dolar; Arna Vukovi(c); Danijela A(a)perger; Kre(s)imir Ko(s)ulti(c)

    2011-01-01

    This study explored the removal of five veterinary pharmaceuticals (VPs) (sulfamethoxazole (SMETOX),trimethopfim (TMP),ciprofloxacin (CIPRO),dexamethasone (DEXA) and febantel (FEBA)) from different water matrices (Milli-Q water,model water,tap water and real pharmaceutical wastewater using four types of nanofiltration (NF) membranes (NF90,NF270,NF and HL) and two reverse osmosis (RO) membranes (LFC-1 and XLE).All VPs were added to different water matrices at a concentration of 10 mg/L.Rejections of VPs and water flux were measured.The rejection increased with increase of molecular weight.The highest rejections were obtained with RO membranes (LFC-1,XLE) and tight NF (NF90) membrane.In general,the rejection of VPs was higher in model water and tap water than in Milli-Q water,but the water flux was lower.This was mainly explained by ion adsorption inside the membranes pores.Narrower pore size counteracted the effect of presence of low concentration of natural organic matter (NOM) in tap water.The NOM was assumed to enhance the adsorption of VPs onto membrane surface,increased the size exclusion and electrostatic repulsion also appeared during the transport.Investigated water matrices had influence on water flux decline due to their complexity.

  16. Sensory quality of drinking water produced by reverse osmosis membrane filtration followed by remineralisation.

    Science.gov (United States)

    Vingerhoeds, Monique H; Nijenhuis-de Vries, Mariska A; Ruepert, Nienke; van der Laan, Harmen; Bredie, Wender L P; Kremer, Stefanie

    2016-05-01

    Membrane filtration of ground, surface, or sea water by reverse osmosis results in permeate, which is almost free from minerals. Minerals may be added afterwards, not only to comply with (legal) standards and to enhance chemical stability, but also to improve the taste of drinking water made from permeate. Both the nature and the concentrations of added minerals affect the taste of the water and in turn its acceptance by consumers. The aim of this study was to examine differences in taste between various remineralised drinking waters. Samples selected varied in mineral composition, i.e. tap water, permeate, and permeate with added minerals (40 or 120 mg Ca/L, added as CaCO3, and 4 or 24 mg Mg/L added as MgCl2), as well as commercially available bottled drinking waters, to span a relevant product space in which the remineralised samples could be compared. All samples were analysed with respect to their physical-chemical properties. Sensory profiling was done by descriptive analysis using a trained panel. Significant attributes included taste intensity, the tastes bitter, sweet, salt, metal, fresh and dry mouthfeel, bitter and metal aftertaste, and rough afterfeel. Total dissolved solids (TDS) was a major determinant of the taste perception of water. In general, lowering mineral content in drinking water in the range examined (from <5 to 440 mg/L) shifted the sensory perception of water from fresh towards bitter, dry, and rough sensations. In addition, perceived freshness of the waters correlated positively with calcium concentration. The greatest fresh taste was found for water with a TDS between 190 and 350 mg/L. Remineralisation of water after reverse osmosis can improve drinking quality significantly. PMID:26925543

  17. Development of new reverse micellar microencapsulation technique to load water-soluble drug into PLGA microspheres.

    Science.gov (United States)

    Kim, Hyunjoo; Cho, Mihyun; Sah, Hongkee

    2005-03-01

    The objective of this study was to develop a new reverse micelle-based microencapsulation technique to load tetracycline hydrochloride into PLGA microspheres. To do so, a reverse micellar system was formulated to dissolve tetracycline hydrochloride and water in ethyl formate with the aid of cetyltrimethylammonium bromide. The resultant micellar solution was used to dissolve 0.3 to 0.75 g of PLGA, and microspheres were prepared following a modified solvent quenching technique. As a control experiment, the drug was encapsulated into PLGA microspheres via a conventional methylene chloride-based emulsion procedure. The microspheres were then characterized with regard to drug loading efficiency, their size distribution and morphology. The reverse micellar procedure led to the formation of free-flowing, spherical microspheres with the size mode of 88 microm. When PLGA microspheres were prepared following the conventional methylene chloride-based procedure, most of tetracycline hydrochloride leached to the aqueous external phase: A maximal loading efficiency observed our experimental conditions was below 5%. Their surfaces had numerous pores, while their internal architecture was honey-combed. In sharp contrast, the new reverse micellar encapsulation technique permitted the attainment of a maximal loading efficiency of 63.19 +/- 0.64%. Also, the microspheres had smooth and pore-free surfaces, and hollow cavities were absent from their internal matrices. The results of this study demonstrated that PLGA microspheres could be successfully prepared following the new reverse micellar encapsulation technique. PMID:15832828

  18. Robust time reversal focusing based on Maximin criterion in a waveguide with uncertain water depth

    Science.gov (United States)

    Pan, Xiang; Wang, Nan; Zhang, JiangFan; Xu, Wen; Gong, XianYi

    2013-10-01

    Time reversal processing (TRP) might be regarded as matched field processing with known environmental knowledge. However, the performance of TRP is degraded in an uncertain environment. A technique based on the Maximin criterion is proposed for enhancing the robustness of TRP in a waveguide with uncertain water depth. The relationship between the water depth and the focal spot translation is examined based on the waveguide-invariant theory. Then the time reversal transmission scheme with the Maximin criterion is performed to maximize the minimum transmission power on a target of interest. At the receiving end, coherent summation operation is carried out over the received data by a reception focusing bank. If it is necessary to enhance the target echo further, the iterative time reversal can be considered where the target echo corresponding to the first time reversal transmission is regarded as a secondary source. Numerical simulations and experimental results of the target localization in a waveguide tank have verified the effectiveness of robust TRP.

  19. EFFICIENCY OF DOMESTIC REVERSE OSMOSIS IN REMOVAL OF TRIHALOMETHANES FROM DRINKING WATER

    Directory of Open Access Journals (Sweden)

    S. Mazloomi ، R. Nabizadeh ، S. Nasseri ، K. Naddafi ، S. Nazmara ، A. H. Mahvi

    2009-10-01

    Full Text Available The reaction of disinfectants with natural organic matters existing in water lead to the formation of Disinfection By-Products. Potentially hazardous and carcinogenic characteristics of trihalomethanes (THMs are recognized. Thus removal of THMs or its precursors are necessary for human health. The aim of this study was to study the efficiency of domestic reverse osmosis (RO in removal of trihalomethanes from drinking water. A pilot scale of RO system with Polyamide membrane as Spiral-Wound, Tape wrapping module was used. Feed solution was made by using of pure chloroform. The samples containing chloroform were analyzed using a gas chromatograph equipped with a flame ionization detector. By increasing the flow, the removal rate of chloroform decreased and with declining removal of EC, the removal of chloroform declined too. In this research, at the worst condition, the efficiency of the pilot scale reverse osmosis reached to 80 % removal of chloroform.

  20. Reverse self-assemblies based on amphiphilic polyphosphazenes for encapsulation of water-soluble molecules

    International Nuclear Information System (INIS)

    A novel series of amphiphilic polyphosphazenes (PNIPAm/AA-PPP) containing hydrophilic oligo-(N-isopropylacrylamide) (oligo-NIPAm) and various hydrophobic aliphatic amines as co-substitutes was synthesized via a two-step substitution reaction. The extraction and solubilization of water-soluble substances such as fluorescein sodium and trypan blue from an aqueous phase into the chloroform phase were supposed to result from the formation of polyphosphazene reverse self-assemblies in the organic phase. A field emission scanning electronic microscope was adopted to characterize the morphology of reverse assemblies in chloroform. Additionally, a significant improvement of encapsulation and release profiles of water-soluble substances was found for poly(lactic-co-glycolic acid) (PLGA) microparticles in the presence of amphiphilic copolymers, which was associated with the chemical structure of copolymers as well as the content of copolymer in the microparticles

  1. Reverse self-assemblies based on amphiphilic polyphosphazenes for encapsulation of water-soluble molecules

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Liyan [College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Zhang Jianxiang [College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Yan Meiqiu [College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Jin Yi [College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Zhu Kangjie [Institute of Polymer Science, Zhejiang University, Hangzhou 310027 (China)

    2007-11-28

    A novel series of amphiphilic polyphosphazenes (PNIPAm/AA-PPP) containing hydrophilic oligo-(N-isopropylacrylamide) (oligo-NIPAm) and various hydrophobic aliphatic amines as co-substitutes was synthesized via a two-step substitution reaction. The extraction and solubilization of water-soluble substances such as fluorescein sodium and trypan blue from an aqueous phase into the chloroform phase were supposed to result from the formation of polyphosphazene reverse self-assemblies in the organic phase. A field emission scanning electronic microscope was adopted to characterize the morphology of reverse assemblies in chloroform. Additionally, a significant improvement of encapsulation and release profiles of water-soluble substances was found for poly(lactic-co-glycolic acid) (PLGA) microparticles in the presence of amphiphilic copolymers, which was associated with the chemical structure of copolymers as well as the content of copolymer in the microparticles.

  2. Effects of Morphology of Cerium Oxide Catalysts for Reverse Water Gas Shift Reaction

    OpenAIRE

    Kovasevic, M.; Mojet, B.L.; Ommen, van, B.; Lefferts, L.

    2016-01-01

    Reverse water gas shift reaction (RWGS) was investigated over cerium oxide catalysts of distinct morphologies: cubes, rods and particles. Catalysts were characterized by X-ray diffraction, Raman spectroscopy and temperature programmed reduction (TPR) in hydrogen. Nanoshapes with high concentration of oxygen vacancies contain less surface oxygen removable in TPR. Cerium oxide cubes exhibited two times higher activity per surface area as compared to rods and particles. Catalytic activity of the...

  3. Specific and reversible DNA-directed self-assembly of oil-in-water emulsion droplets

    OpenAIRE

    Hadorn, Maik; Bönzli, Eva; Sørensen, Kristian; Fellermann, Harold; Hotz, Peter Eggenberger; Hanczyc, Martin

    2012-01-01

    Higher-order structures that originate from the specific and reversible DNA-directed self-assembly of microscopic building blocks hold great promise for future technologies. Here, we functionalized biotinylated soft colloid oil-in-water emulsion droplets with biotinylated single-stranded DNA oligonucleotides using streptavidin as an intermediary linker. We show the components of this modular linking system to be stable and to induce sequence-specific aggregation of binary mixtures of emulsion...

  4. Shape evolution of Cu2S nanostructures in Triton X-100/cyclohexane/water reverse micelles

    International Nuclear Information System (INIS)

    The shape evolution of Cu2S nanostructures, which were produced in Triton X-100/cyclohexane/water reverse micelles, was investigated by the transmission electron microscopy technique as a function of aging time, and the effect of the molar ratio of water to surfactant on the size and shape of Cu2S nanostructures was also discussed. The results suggest that at the initial stage the nucleation process was dominant and the shape of Cu2S nanostructures was preferably confined by the reverse micelle droplets and took spherical forms. With the extension of the aging time, the growth gradually governed the process and the shape of Cu2S nanostructures evolved first to nanorods, and then to nanowires gradually. The formation of one-dimensional Cu2S nanostructures is attributed to a directed aggregation growth process mediated by reverse micelle droplets, which was confirmed by high-resolution transmission electron microscopy. Furthermore, the size and shape of Cu2S nanostructures can be controlled by changing the molar ratio of water to surfactant

  5. Structural Properties of Water Nano-pockets Encapsulated in Polymerized Reverse Micelles

    Science.gov (United States)

    Urquidi, Jacob; Banuelos, Jose L.; Levinger, Nancy

    2009-03-01

    Reverse micelles, that is, small surfactant coated droplets of polar solvent, can form in a range of systems of varying surfactant and polar solvent. SANS has been used to characterize the shape, size and polydispersity of these reverse micelle systems which are macroscopically clear but nanoscopically heterogeneous. Particular sensor applications have been developed using a reverse micellar starting material to create a sample that is macroscopically a robust solid with encapsulated nanoscopic pockets of fluid. This poster will discuss the nanopockets of the fluid phase (water in this case) within the matrix as investigated by small angle X-ray scattering (SAXS) and neutron scattering techniques. The SAXS technique was used to investigate the polydispersity, shape, and distribution of the nanopockets of fluid. Neutron scattering was used to lend insight into the nature of the water encapsulated within these micelles by looking at the position, width, and height of the First Sharp Diffraction Peak (FSDP) to probe the physical perturbations that the water is subject to.

  6. Droplet polydispersity and shape fluctuations in AOT [bis(2-ethylhexyl)sulfosuccinate sodium salt] microemulsions studied by contrast variation small-angle neutron scattering

    DEFF Research Database (Denmark)

    Arleth, L.; Pedersen, J.S.

    2001-01-01

    Microemulsions consisting of AOT water, and decane or iso-octane are studied in the region of the phase diagram where surfactant covered water droplets are formed. The polydispersity and shape fluctuations of the microemulsion droplets are determined and compared in the two different alkane types....... Conductivity measurements show that there is a pronounced dependence of the temperature behavior of the microemulsion on the type of alkane used. In both cases the microemulsion droplets start to form larger aggregates when the temperature increases. But in the system with decane this aggregation temperature...... occurs at a temperature about 10 degreesC lower than in a similar system with iso-octane. Aggregation phenomena are avoided and the two systems are at approximately the same reduced temperature with respect to the aggregation temperature when the temperature of the AOT/D2O/decane microemulsion is 10...

  7. Immobilization of RuS2 Nanoparticles Prepared in Reverse Micellar System onto Thiol-Modified Polystyrene Particles and their Photocatalytic Properties

    International Nuclear Information System (INIS)

    RuS2 nanoparticles, smaller than 3 nm in diameter, were prepared by H2S gas injection into the AOT/isooctane reverse micellar solution containing RuCl3 aqueous solution. The nanoparticle size was found to be independent of the Wo (water content) value of the reverse micellar system, as shown by TEM observation. The recovery and immobilization of the RuS2 nanoparticles from reverse micelles onto thiol-modified polystyrene particles (PSt-SH) were successfully carried out, by the addition of PSt-SH into the reverse micellar solution under conditions of mild stirring. The resulting composites, PSt-RuS2, showed photocatalytic activity for H2 generation form aqueous solution containing 2-propanol and Na2SO3 as sacrificial electron donors

  8. Water permeability of nanoporous graphene at realistic pressures for reverse osmosis desalination

    International Nuclear Information System (INIS)

    Nanoporous graphene (NPG) shows tremendous promise as an ultra-permeable membrane for water desalination thanks to its atomic thickness and precise sieving properties. However, a significant gap exists in the literature between the ideal conditions assumed for NPG desalination and the physical environment inherent to reverse osmosis (RO) systems. In particular, the water permeability of NPG has been calculated previously based on very high pressures (1000–2000 bars). Does NPG maintain its ultrahigh water permeability under real-world RO pressures (<100 bars)? Here, we answer this question by drawing results from molecular dynamics simulations. Our results indicate that NPG maintains its ultrahigh permeability even at low pressures, allowing a permeate water flux of 6.0 l/h-bar per pore, or equivalently 1041 ± 20 l/m2-h-bar assuming a nanopore density of 1.7 × 1013 cm−2

  9. Water permeability of nanoporous graphene at realistic pressures for reverse osmosis desalination

    Energy Technology Data Exchange (ETDEWEB)

    Cohen-Tanugi, David; Grossman, Jeffrey C. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2014-08-21

    Nanoporous graphene (NPG) shows tremendous promise as an ultra-permeable membrane for water desalination thanks to its atomic thickness and precise sieving properties. However, a significant gap exists in the literature between the ideal conditions assumed for NPG desalination and the physical environment inherent to reverse osmosis (RO) systems. In particular, the water permeability of NPG has been calculated previously based on very high pressures (1000–2000 bars). Does NPG maintain its ultrahigh water permeability under real-world RO pressures (<100 bars)? Here, we answer this question by drawing results from molecular dynamics simulations. Our results indicate that NPG maintains its ultrahigh permeability even at low pressures, allowing a permeate water flux of 6.0 l/h-bar per pore, or equivalently 1041 ± 20 l/m{sup 2}-h-bar assuming a nanopore density of 1.7 × 10{sup 13} cm{sup −2}.

  10. Sensory quality of drinking water produced by reverse osmosis membrane filtration followed by remineralisation

    DEFF Research Database (Denmark)

    Vingerhoeds, Monique H.; Nijenhuis-de Vries, Mariska A.; Ruepert, Nienke;

    2016-01-01

    to their physical-chemical properties. Sensory profiling was done by descriptive analysis using a trained panel.Significant attributes included taste intensity, the tastes bitter, sweet, salt, metal, fresh and dry mouthfeel, bitter and metal aftertaste, and rough afterfeel. Total dissolved solids (TDS) was a major...... determinant of the taste perception of water. In general, lowering mineral content in drinking water in the range examined (from......Membrane filtration of ground, surface, or sea water by reverse osmosis results in permeate, which is almost free from minerals. Minerals may be added afterwards, not only to comply with (legal) standards and to enhance chemical stability, but also to improve the taste of drinking water made from...

  11. Nanofiltration in Transforming Surface Water into Healthy Water: Comparison with Reverse Osmosis

    OpenAIRE

    Naidu, L. D.; Saravanan, S.; Chidambaram, M.; Mukesh Goel; Ashutosh Das; J. Sarat Chandra Babu

    2015-01-01

    The natural surface water, especially available through rivers, is the main source of healthy water for the living beings throughout the world from ancient days as it consists of all essential minerals. With the advent of industrialization, gradually even the most prominent rivers have been polluted in all parts of the world. Although there are lots of technologies, nanofiltration (NF) has been chosen to transform river water into healthy water due to its unique advantages of retaining optimu...

  12. Indirect desalination of Red Sea water with forward osmosis and low pressure reverse osmosis for water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor

    2011-10-01

    The use of energy still remains the main component of the costs of desalting water. Forward osmosis (FO) can help to reduce the costs of desalination, and extracting water from impaired sources can be beneficial in this regard. Experiments with FO membranes using a secondary wastewater effluent as a feed water and Red Sea water as a draw solution demonstrated that the technology is promising. FO coupled with low pressure reverse osmosis (LPRO) was implemented for indirect desalination. The system consumes only 50% (~1.5 kWh/m3) of the energy used for high pressure seawater RO (SWRO) desalination (2.5-4 kWh/m3), and produces a good quality water extracted from the impaired feed water. Fouling of the FO membranes was not a major issue during long-term experiments over 14 days. After 10 days of continuous FO operation, the initial flux declined by 28%. Cleaning the FO membranes with air scouring and clean water recovered the initial flux by 98.8%. A cost analysis revealed FO per se as viable technology. However, a minimum average FO flux of 10.5 L/m2-h is needed to compete with water reuse using UF-LPRO, and 5.5 L/m2-h is needed to recover and desalinate water at less cost than SWRO. © 2011 Elsevier B.V.

  13. Validation and empirical correction of MODIS AOT and AE over ocean

    Directory of Open Access Journals (Sweden)

    N. A. J. Schutgens

    2013-09-01

    Full Text Available We present a validation study of Collection 5 MODIS level 2 Aqua and Terra AOT (aerosol optical thickness and AE (Ångström exponent over ocean by comparison to coastal and island AERONET (AErosol RObotic NETwork sites for the years 2003–2009. We show that MODIS (MODerate-resolution Imaging Spectroradiometer AOT exhibits significant biases due to wind speed and cloudiness of the observed scene, while MODIS AE, although overall unbiased, exhibits less spatial contrast on global scales than the AERONET observations. The same behaviour can be seen when MODIS AOT is compared against Maritime Aerosol Network (MAN data, suggesting that the spatial coverage of our datasets does not preclude global conclusions. Thus, we develop empirical correction formulae for MODIS AOT and AE that significantly improve agreement of MODIS and AERONET observations. We show these correction formulae to be robust. Finally, we study random errors in the corrected MODIS AOT and AE and show that they mainly depend on AOT itself, although small contributions are present due to wind speed and cloud fraction in AOT random errors and due to AE and cloud fraction in AE random errors. Our analysis yields significantly higher random AOT errors than the official MODIS error estimate (0.03 + 0.05 τ, while random AE errors are smaller than might be expected. This new dataset of bias-corrected MODIS AOT and AE over ocean is intended for aerosol model validation and assimilation studies, but also has consequences as a stand-alone observational product. For instance, the corrected dataset suggests that much less fine mode aerosol is transported across the Pacific and Atlantic oceans.

  14. Nanofiltration in Transforming Surface Water into Healthy Water: Comparison with Reverse Osmosis

    Directory of Open Access Journals (Sweden)

    L. D. Naidu

    2015-01-01

    Full Text Available The natural surface water, especially available through rivers, is the main source of healthy water for the living beings throughout the world from ancient days as it consists of all essential minerals. With the advent of industrialization, gradually even the most prominent rivers have been polluted in all parts of the world. Although there are lots of technologies, nanofiltration (NF has been chosen to transform river water into healthy water due to its unique advantages of retaining optimum TDS (with essential minerals required for human body, consuming of lower energy, and no usage of any chemicals. The prominent parameters of surface water and macro/microminerals of treated water have been analyzed. It is shown that NF is better in producing healthy water with high flux by consuming low energy.

  15. Effect of water temperature on biofouling development in reverse osmosis membrane systems

    KAUST Repository

    Farhat, N.M.

    2016-07-14

    Understanding the factors that determine the spatial and temporal biofilm development is a key to formulate effective control strategies in reverse osmosis membrane systems for desalination and wastewater reuse. In this study, biofilm development was investigated at different water temperatures (10, 20, and 30 °C) inside a membrane fouling simulator (MFS) flow cell. The MFS studies were done at the same crossflow velocity with the same type of membrane and spacer materials, and the same feed water type and nutrient concentration, differing only in water temperature. Spatially resolved biofilm parameters such as oxygen decrease rate, biovolume, biofilm spatial distribution, thickness and composition were measured using in-situ imaging techniques. Pressure drop (PD) increase in time was used as a benchmark as to when to stop the experiments. Biofilm measurements were performed daily, and experiments were stopped once the average PD increased to 40 mbar/cm. The results of the biofouling study showed that with increasing feed water temperature (i) the biofilm activity developed faster, (ii) the pressure drop increased faster, while (iii) the biofilm thickness decreased. At an average pressure drop increase of 40 mbar/cm over the MFS for the different feed water temperatures, different biofilm activities, structures, and quantities were found, indicating that diagnosis of biofouling of membranes operated at different or varying (seasonal) feed water temperatures may be challenging. Membrane installations with a high temperature feed water are more susceptible to biofouling than installations fed with low temperature feed water.

  16. Electrodialysis reversal: Process and cost approximations for treating coal-bed methane waters

    Energy Technology Data Exchange (ETDEWEB)

    Sajtar, E.T.; Bagley, D.M. [University of Wyoming, Laramie, WY (United States)

    2009-02-15

    Brackish waters with total dissolved solids (TDS) concentrations less than 10,000 mg/L are extracted from coal-beds in the Wyoming Powder River basin to facilitate the production of coal-bed methane. These waters frequently require treatment before disposal or use. Electrodialysis reversal (EDR) has not yet been used to treat these waters but this technology should be suitable. The question is whether EDR would be cost-effective. The purpose of this work, then, was to develop models for predicting the cost of EDR for brackish waters. These models, developed from data available in the literature, were found to predict actual EDR costs as a function of TDS removal, influent flow rate, chemical rejection efficiency, water recovery, electricity use, and labor cost within 10% of reported values. The total amortized cost for removing 1,000 mg/L of TDS from 10,000 m{sup 3}/day of influent assuming no concentrate disposal costs was predicted to range from $0.23/m{sup 3} to $0.85/m{sup 3} and was highly dependent on capital cost and facility life. Concentrate disposal costs significantly affected total treatment cost, providing a total treatment cost range from $0.38/m{sup 3} to $6.38/m{sup 3}, depending on concentrate disposal cost and water recovery. Pilot demonstrations of EDR in the Powder River basin should be conducted to determine the achievable water recovery when treating these waters.

  17. Spraying enzymes in microemulsions of AOT in nonpolar organic solvents for fabrication of enzyme electrodes.

    Science.gov (United States)

    Shipovskov, Stepan; Trofimova, Daria; Saprykin, Eduard; Christenson, Andreas; Ruzgas, Tautgirdas; Levashov, Andrey V; Ferapontova, Elena E

    2005-11-01

    A new technique suitable for automated, large-scale fabrication of enzyme electrodes by air-spraying enzymes in organic inks is presented. Model oxidoreductases, tyrosinase (Tyr) and glucose oxidase (GOx), were adapted to octane-based ink by entrapment in a system of reverse micelles (RM) of surfactant AOT in octane to separate and stabilize the catalytically active forms of the enzymes in nonpolar organic media. Nonpolar caoutchouk polymer was also used to create a kind of "dry micelles" at the electrode/solution interface. Enzyme/RM/polymer-containing organic inks were air-brushed onto conductive supports and were subsequently covered by sprayed Nafion membranes. The air-brushed enzyme electrodes exhibited relevant bioelectrocatalytic activity toward catechol and glucose, with a linear detection range of 0.1-100 microM catechol and 0.5-7 mM glucose; the sensitivities were 2.41 A M(-1) cm(-2) and 2.98 mA M(-1) cm(-2) for Tyr and GOx electrodes, respectively. The proposed technique of air-brushing enzymes in organic inks enables automated construction of disposable enzyme electrodes of various designs on a mass-production scale. PMID:16255612

  18. Dynamics of water and solute transport in polymeric reverse osmosis membranes via molecular dynamics simulations

    CERN Document Server

    Shen, Meng; Lueptow, Richard M

    2016-01-01

    The Angstrom-scale transport characteristics of water and six different solutes, methanol, ethanol, 2-propanol, urea, Na+, and Cl-, were studied for a polyamide reverse osmosis (RO) membrane, FT-30, using non-equilibrium molecular dynamics (NEMD) simulations. Results indicate that water transport increases with an increasing fraction of connected percolated free volume, or water-accessible open space, in the membrane polymer structure. This free volume is enhanced by the dynamic structure of the membrane at the molecular level as it swells when hydrated and vibrates due to molecular collisions allowing a continuous path connecting the opposite membrane surfaces. The tortuous paths available for transport of solutes result in Brownian motion of solute molecules and hopping from pore to pore as they pass through the polymer network structure of the membrane. The transport of alcohol solutes decreases for solutes with larger Van der Waals volume, which corresponds to less available percolated free volume, or sol...

  19. Size-controlled synthesis of ZrO2-TiO2 nanoparticles prepared via reverse micelle method

    International Nuclear Information System (INIS)

    Zirconium-titanium mixed oxide nanoparticles have been synthesized using microreactors made of bis-(2-ethylhexyl) sulfosuccinate (AOT)/water/n-hexane microemulsions. The control of particle size was achieved by varying the process variables, such as water-to-surfactant molar ratio and reagent concentration. Their sizes, appearances, crystal structures, pore diameter and surface area were characterized by TEM, XRD, N2 adsorption/desorption methods. The results revealed that samples prepared in reverse micelles had no crystalline phase. The Beckmann rearrangement of cyclohexanone oxime on ZrO2-TiO2 nanoparticles was carried out in a fixed-bed down flow reactor to investigate the effect of particle size on catalytic activity and selectivity. Samples synthesized in reverse micelles had better reaction performance than samples prepared via sol-gel method. A parallel relationship could be drawn between the catalytic activity and the particle size as well as the selectivity of the catalyst

  20. Performances of nano filtration (NF) and reverse osmosis (RO) in textile industry waste water treatment

    International Nuclear Information System (INIS)

    Textile industry process (dyeing, bleaching, printing and finishing) require a high-water consumption generating high amounts of water. Reactive dyeing of 1Kg of cotton requires about 150 Litres of water and 40g reactive dye resulting in a large volume of strongly coloured effluents. This fact in combination with the current water scarcity makes necessary textile waste water reuse. In this paper experimental results obtained from the treatment by different membranes Micro filtration (MF), Nano filtration (NF) and Reverse Osmosis (RO) of Sitex industry waste water pretreated by biological activated sludge are presented and compared. The results obtained from direct Nano filtration performed at different transmembrane pressures (8-1 m-2 for a Volumetric Concentration Factor (VCF) of 4 and that the osmotic pressure π= 4Bars. A high quality of treated effluent in term of colour removal and desalination was obtained for a VCF of 2: salinity retention rate (RR) 57 pour cent and discoloration almost 100 pour cent at pressure of 12 bar. While, the permeate flux obtained using the combination MF/RO at a different pressures 25-1m-2 for a VCF of 6 indicating an important fouling. In this case, the osmotic pressure varied from 6 to 28 bars. The optimum salinity and colour retention rate (RR) were 86 pour cent and 100 pour cent respectively obtained at a VCF of 2.

  1. Use of water processed by reverse osmosis For vapor generation in tobacco industry

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Klimeck Gouvea

    2012-06-01

    Full Text Available This article presents a study due to the technical use of reverse osmosis to treat the boiler water for steam generation in a plant of tobacco processing in Santa Catarina, Brazil. The monitoring was conducted between the years 2006 to 2008, presenting the results concerning the improvement of water quality with emphasis on environmental and financial gains. Water quality can be observed by the reduction of 90% in silica content and 100% hardness, leading to a reduction of incrustation and corrosion of the system. Moreover, a reduction in the discharges water from the boiler volume reduced the water consumption by approximately 6,000 m3/year and also the consumption of chemicals used in wastewater treatment plant, with a reduction of 32.76 m3/day of effluents to treatment. The reducing of energy with natural gas for water heating replacement was almost 900,000 m3/year (19.45%, because of increased in heat exchange efficiency. The reducing in the CO2 emissions was in order of 1215,65 t/year. Finally, based on the achieved results obtained, can be possible to assume a reducing costs of production as a whole.

  2. Validation and empirical correction of MODIS AOT and AE over ocean

    OpenAIRE

    N. A. J. Schutgens; Nakata, M; Nakajima, T.

    2013-01-01

    We present a validation study of Collection 5 MODIS level 2 Aqua and Terra AOT (aerosol optical thickness) and AE (Ångström exponent) over ocean by comparison to coastal and island AERONET (AErosol RObotic NETwork) sites for the years 2003–2009. We show that MODIS (MODerate-resolution Imaging Spectroradiometer) AOT exhibits significant biases due to wind speed and cloudiness of the observed scene, while MODIS AE, although overall unbiased, exhibits less spatial contrast on global scales than ...

  3. Treatment of tailings water from uranium ore processing by reverse osmosis

    International Nuclear Information System (INIS)

    Mining and metallurgical waste waters are considered to be the major sources of heavy metal contamination. The need of economic and effective methods for metals removal have resulted in the development of new separation technologies. Precipitation, ion exchange, electrochemical processes, filtration and flotation are commonly applied for industrial effluents treatment. Occasionally, the application of such processes is limited because of technical or economical constraints. The search for new technologies regarding the recovery and removal of toxic metals from waste waters has directed attention to membrane processes. These processes are developed in the recent years due to the availability of many new types of membranes. This paper presents the laboratory test results for liquid radioactive effluent treatment from alkaline uranium ore processing by reverse osmosis. (author)

  4. Nanofiltration vs. reverse osmosis for the removal of emerging organic contaminants in water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor

    2011-10-01

    Reverse osmosis (RO) in existing water reuse facilities is a water industry standard. However, that approach may be questioned taking into consideration that "tight" NF can be equal or "better" than RO. NF can achieve the same removals of RO membranes when dealing with emerging organic contaminants (pharmaceuticals, pesticides, endocrine disruptors and others). Experiments using 18 emerging contaminants were performed using membranes NF200 and NF90 at bench-scale units, and for a more complete study, results of NF and RO pilot and full-scale experiments where compared to our experimental results. The removal results showed that NF can remove many emerging contaminants. The average removal by tight NF was 82% for neutral contaminants and 97% for ionic contaminants. The average removal by RO was 85% for neutral contaminants and 99% for ionic contaminants. Aquifer recharge and recovery (ARR) followed by NF can effectively remove emerging contaminants with removals over 90% when loose NF membranes are used.

  5. One-step reverse precipitation synthesis of water-dispersible superparamagnetic magnetite nanoparticles

    International Nuclear Information System (INIS)

    Hydrophilic functionalization of nanoparticle surface is essential for their biomedical applications. Herein, we report a facile one-step reverse precipitation method to synthesize water-dispersible, biocompatible, and carboxylate-functionalized superparamagnetic magnetite (Fe3O4) nanoparticles with the help of biocompatible sodium citrate salt. Transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), zeta potential measurement, dynamic light scattering (DLS), and superconducting quantum interference device (SQUID) were used to characterize the as-prepared magnetite nanoparticles. The size of the as-prepared magnetite nanoparticles was tuned from 27 ± 3.8 to 4.8 ± 1.9 nm by changing the sodium citrate concentration from 25 to 125 mM. The sodium citrate concentration also influenced the water-dispersible stability of the as-prepared magnetite nanoparticles, which was due to the electrostatic repulsion.Graphical Abstract

  6. A comparative study of boron and arsenic (III) rejection from brackish water by reverse osmosis membranes

    KAUST Repository

    Teychene, Benoît

    2013-02-01

    This study aims to compare at lab-scale the rejection efficiency of several reverse osmosis membranes (RO) toward arsenic (III) and boron during the filtration of a synthetic brackish water. The effect of pH and operating conditions on the rejection of each RO membrane was studied. Two types of membrane were investigated: "brackish water" and "sea water" membranes. Our results showed that the metalloid rejection depends on the membrane type, pH and transmembrane pressure applied. Increasing pH above the dissociation constant (pKa) of each specie improves significantly the metalloid rejection by RO membranes, whatever the membrane type. Moreover, at identical operating conditions (pH, transmembrane pressure), results showed that the brackish water membranes have a higher water flux and exhibit lower metalloid rejection. The highest As(III) rejection value for the tested brackish water membranes was 99% obtained at pH = 9.6 and 40 bars, whereas it was found that the sea water RO membranes could highly reject As(III), more than 99%, even at low pH and low pressure (pH = 7.6 and 24 bars).Regarding Boron rejection, similar conclusions could be drawn. The sea water RO membranes exert higher removal, with a high rejection value above 96% over the tested conditions. More generally, this study showed that, whatever the operating conditions or the tested membranes, the boron and As(III) permeate concentrations are below the WHO guidelines. In addition, new data about the boron and arsenic permeability of each tested RO membrane was brought thanks to a theoretical calculation. © 2012 Elsevier B.V.

  7. Preparation and water desalination properties of POSS-polyamide nanocomposite reverse osmosis membranes

    KAUST Repository

    Duan, Jintang

    2015-01-01

    The application of nanotechnology to thin-film nanocomposites (TFN) is a new route to enhance membrane performance in water desalination. Here, the potential of polyhedral oligomeric silsesquioxane (POSS) as the nanofiller in polyamide (PA) reverse osmosis membranes was systematically investigated. Four POSS materials (P-8Phenyl, P-8NH3Cl, P-8NH2 and P-1NH2) were introduced into the selective layer by physical blending or chemical fixation during standard interfacial polymerization. Water flux and NaCl rejection were measured with 2000ppm NaCl solution under 15.5bar pressure, and SEM and TEM images of membrane selective layers were obtained. Membranes prepared without POSS showed water flux of 20.0±0.5L/m2·h and salt rejection of 98.0±0.2%. TFN membranes prepared with 0.4% (w/v) P-8Phenyl in the organic phase showed a 65% increase in water flux compared to the pristine PA membrane while maintaining high salt rejection. The selective layer of this membrane maintained the typical ridge-and-valley structure of aromatic PA. Results with P-8NH3Cl and P-8NH2 added to the organic phase were similar. TFN membranes prepared with monoamine P-1NH2 in the organic phase had poor water flux of 3.2L/m2·h, a smooth and more hydrophobic surface, and a much thicker (~400nm) selective layer. One of the four POSS compounds studied, P-8NH3Cl, is sufficiently soluble in water for incorporation into the selective layer via the aqueous phase. Membranes were prepared with P-8NH3Cl in the aqueous phase at varying reaction time, loading, and additive (triethylamine) concentration. With these parameters optimized, water flux increased to 35.4L/m2·h.

  8. Proton transfer in ionic and neutral reverse micelles.

    Science.gov (United States)

    Lawler, Christian; Fayer, Michael D

    2015-05-14

    Proton-transfer kinetics in both ionic and neutral reverse micelles were studied by time-correlated single-photon counting investigations of the fluorescent photoacid 8-hydroxypyrene-1,3,6-trisulfonate (HPTS). Orientational dynamics of dissolved probe molecules in the water pools of the reverse micelles were also investigated by time-dependent fluorescence anisotropy measurements of MPTS, the methoxy derivative of HPTS. These experiments were compared to the same experiments in bulk water. It was found that in ionic reverse micelles (surfactant Aerosol OT, AOT), orientational motion (fluorescence anisotropy decay) of MPTS was relatively unhindered, consistent with MPTS being located in the water core of the reverse micelle away from the water-surfactant interface. In nonionic reverse micelles (surfactant Igepal CO-520, Igepal), however, orientational anisotropy displayed a slow multiexponential decay consistent with wobbling-in-a-cone behavior, indicating MPTS is located at the water-surfactant interface. HPTS proton transfer in ionic reverse micelles followed kinetics qualitatively like those in bulk water, albeit slower, with the long-time power law time dependence associated with recombination of the proton with the dissociated photoacid, suggesting a modified diffusion-controlled process. However, the power law exponents in the ionic reverse micelles are smaller (∼ -0.55) than that in bulk water (-1.1). In neutral reverse micelles, proton-transfer kinetics did not show discernible power law behavior and were best represented by a two-component model with one relatively waterlike population and a population with a faster fluorescence lifetime and negligible proton transfer. We explain the Igepal results on the basis of close association between the probe and the neutral water-surfactant interface, with the probe experiencing a distribution of more and less waterlike environments. In addition, the observation in bulk water of a power law t(-1.1) for diffusion

  9. Operation and performance of reverse osmosis modules in large sea water desalination plants

    International Nuclear Information System (INIS)

    Reverse osmosis (RO) processes, with advantages such as low energy and space requirements, have been adopted in the water purification system of the power generation industry. High quality boiler feedwater is increasingly in demand for power plants. Toyobo double element RO modules have been used in the sea water desalination plants installed in two nuclear power plants and in operation for more than 5 years. This RO module consists of a cellulose triacetate hollow fibre membrane, therefore it has several merits such as high salt rejection, chlorine tolerance and resistance to organic fouling. The operating data obtained from these sea water desalination plants demonstrate that RO performance (e.g. productivity and salt rejection) has been stable and met plant specifications for a long period of time. The RO performance monitoring system has been utilized effectively to minimize the annual replacement ratio of RO elements. Double element RO modules are also widely used in large sea water desalination plants in the Middle East because of the advantages they offer, such as high salt rejection and ease of operation and maintenance. (author)

  10. Contaminants of emerging concern in reverse osmosis brine concentrate from indirect/direct water reuse applications.

    Science.gov (United States)

    Romeyn, Travis R; Harijanto, Wesley; Sandoval, Sofia; Delagah, Saied; Sharbatmaleki, Mohamadali

    2016-01-01

    Water shortage is becoming more common due to droughts and global population increases resulting in the increasing popularity of water reuse to create new water sources. Reverse osmosis (RO) membrane systems are popular in these applications since they can produce drinking water quality effluent. Unfortunately, RO systems have the drawback of generating concentrate streams that contain contaminants rejected by the membrane including chemicals of emerging concern (CECs). CECs are chemicals such as hormones, steroids, pesticides, pharmaceuticals, and personal care products that are used for their intended purpose and then released into wastewater. CECs are believed to be detrimental to aquatic wildlife health and pose an unknown human health risk. This research gathered the existing knowledge on CEC presence in concentrate, available proven concentrate treatment methods, their CEC removal abilities, and current CEC regulations. It was found that 127 CECs have been measured in RO concentrate with 100 being detected at least once. The most potent treatment process available is UV/H2O2 as it offers the highest removal rates for the widest range of chemicals. The less expensive process of ozone/biologically activated carbon offers slightly lower removal abilities. This comprehensive report will provide the groundwork for better understanding, regulating and treating concentrate stream CECs. PMID:26819378

  11. Determination of water states and the structural parameters of W/O microemulsions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The states of water in sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane/water reverse(W/O) microemulsions system have been investigated by using Fourier transform infrared spectroscopy(FT-IR) technique. The broad peak obtained for hydroxy(O-H) of water has been resolved by least square curve-fitting. It has been observed that the water solubilized in microemulsion droplets has four states, i.e. bound water with sulfo-group, free water, bound water with sodium counterion in the water pool of microemulsion droplets and a small amount of trapped water in the palisade layer of microemulsion droplets. The following have also been determined: the aggregation number (n), the radius of the water pool in the microemulsions(rw), the thickness of the bound water with sulfo-group(d1), the thickness of the bound water with sodium counterion(d2), the total thickness of the bound water ( d ) and the effective area of head groups of AOT(AAOT).

  12. Diagnosis of small capacity reverse osmosis desalination unit for domestic water

    International Nuclear Information System (INIS)

    Tunisian norm of drinking water tolerates a maximum TDS of 1.5 g/L, and the domestic water presents usually a salinity grater than 500 mg/L. In the last years, several small capacity reverse osmosis desalination prototypes have been marketed. They are used to desalinate brackish water with TDS lower than 1.5 g/L. This RO unit, tested with tap waters during four years, was diagnosed. The RO unit produces 10-15 L/Hour with a recovery rate between 25 and 40 pour cent and salt rejection in order of 90 pour cent. The salinity of the tested domestic water is located between 0.4 and 1.4 g/L. Water pretreatment is composed of three filtration operations (cartridge filter, granulate active carbon filter and 5 =m cartridge filter). Pretreated water is pumped through RO membrane with maximum pressure of 6 bars. At the 4th year, the RO unit performances were substantial decreased. Recovery rate and salt rejection fall down more than 50 and 100% respectively and the pressure drop increase from 1 to 2.1 bar The membrane regeneration allowed only the rate recovery restoration. The membrane selectivity was not improved. The membrane seems irreversibly damaged by the tap water chlorine none retained by the deficient pretreatment. An autopsy of the used RO membrane was done by different analysis techniques as SEM/EDX, AFM, XRD and FTIR spectroscopy. The analysis of membrane (proper and used) surfaces show a deposit film on the used membrane witch evaluated to environ 2 =m, it indicates a fooling phenomenon. The SEM photos show deterioration on the active layer material of the membrane witch seems attacked by the tap water chlorine. The X Rays Diffraction and FTIR show that the deposit collected on the used membrane contains organic and mineral (Gypsum, SiO2 and clays) materials. Silicates and clays can exist in tap waters and reach the RO membrane when the pretreatment micro-filter became deficient. The Gypsum presence is due only to germination on the membrane.

  13. TR-ESR Investigation on Reaction of Vitamin C with Excited Triplet of 9,10-phenanthrenequinone in Reversed Micelle Solutions

    Science.gov (United States)

    Xu, Xin-sheng; Shi, Lei; Liu, Yi; Ji, Xue-han; Cui, Zhi-feng

    2011-04-01

    Time-resolved electron spin resonance has been used to study quenching reactions between the antioxidant Vitamin C (VC) and the triplet excited states of 9,10-phenanthrenequinone (PAQ) in ethylene glycol-water (EG-H2O) homogeneous and inhomogeneous reversed micelle solutions. Reversed micelle solutions were used to be the models of physiological environment of biological cell and tissue. In PAQ/EG-H2O homogeneous solution, the excited triplet of PAQ (3PAQ*) abstracts hydrogen atom from solvent EG. In PAQ/VC/EG-H2O solution, 3PAQ* abstracts hydrogen atom not only from solvent EG but also from VC. The quenching rate constant of 3PAQ* by VC is close to the diffusion-controlled value of 1.41 × 108 L/(mol ·s). In hexadecyltrimethylammonium bromide (CTAB)/EG-H2O and aerosol OT (AOT)/EG-H2O reversed micelle solutions, 3PAQ* and VC react around the water-oil interface of the reversed micelle. Exit of 3PAQ* from the lipid phase slows down the quenching reaction. For Triton X-100 (TX-100)/EG-H2O reversed micelle solution, PAQ and VC coexist inside the hydrophilic polyethylene glycol core, and the quenching rate constant of 3PAQ* by VC is larger than those in AOT/EG-H2O and CTAB/EG-H2O reversed micelle solutions, even a little larger than that in EG-H2O homogeneous solution. The strong emissive chemically induced dynamic electron polarization of As.- resulted from the effective TM spin polarization transfer in hydrogen abstraction of 3PAQ* from VC.

  14. Reverse water gas shift reaction over Co-precipitated Ni-CeO2 catalysts

    Institute of Scientific and Technical Information of China (English)

    WANG Luhui; ZHANG Shaoxing; LIU Yuan

    2008-01-01

    The Ni-CeO2 catalysts with different Ni contents were prepared by a co-precipitation method and used for Reverse Water Gas Shift (RWGS) reaction. 2wt.%Ni-CeO2 showed excellent catalytic performance in terms of activity, selectivity, and stability for RWGS reaction. Characterizations of the catalyst samples were conducted by XRD and TPR. The results indicated that, in Ni-CeO2 catalysts, there were three kinds of nickel, nickel ions in ceria lattice, highly dispersed NiO and bulk NiO. Oxygen vacancies were formed in CeO2 lattice due to the incorporation of Ni2+ ions into ceria lattice. Oxygen vacancies formed in ceda lattice and highly dispersed Ni were key active components for RWGS, and bulk Ni was key active component for methanation of CO2.

  15. Removal of bisphenol A (BPA) from water by various nanofiltration (NF) and reverse osmosis (RO) membranes.

    Science.gov (United States)

    Yüksel, Suna; Kabay, Nalan; Yüksel, Mithat

    2013-12-15

    The removal of an endocrine disrupting compound, bisphenol A (BPA), from model solutions by selected nanofiltration (NF) and reverse osmosis (RO) membranes was studied. The commercially available membranes NF 90, NF 270, XLE BWRO, BW 30 (Dow FilmTech), CE BWRO and AD SWRO (GE Osmonics) were used to compare their performances for BPA removal. The water permeability coefficients, rejection of BPA and permeate flux values were calculated for all membranes used. No significant changes in their BPA removal were observed for all tight polyamide based NF and RO membranes tested except for loose NF 270 membrane. The polyamide based membranes exhibited much better performance than cellulose acetate membrane for BPA removal. Almost a complete rejection (≥ 98%) for BPA was obtained with three polyamide based RO membranes (BW 30, XLE BWRO and AD SWRO). But cellulose acetate based CE BWRO membrane offered a low and variable (10-40%) rejection for BPA. PMID:23731784

  16. Subsurface intakes for seawater reverse osmosis facilities: Capacity limitation, water quality improvement, and economics

    KAUST Repository

    Missimer, Thomas M.

    2013-08-01

    The use of subsurface intake systems for seawater reverse osmosis (SWRO) desalination plants significantly improves raw water quality, reduces chemical usage and environmental impacts, decreases the carbon footprint, and reduces cost of treated water to consumers. These intakes include wells (vertical, angle, and radial type) and galleries, which can be located either on the beach or in the seabed. Subsurface intakes act both as intakes and as part of the pretreatment system by providing filtration and active biological treatment of the raw seawater. Recent investigations of the improvement in water quality made by subsurface intakes show lowering of the silt density index by 75 to 90%, removal of nearly all algae, removal of over 90% of bacteria, reduction in the concentrations of TOC and DOC, and virtual elimination of biopolymers and polysaccharides that cause organic biofouling of membranes. Economic analyses show that overall SWRO operating costs can be reduced by 5 to 30% by using subsurface intake systems. Although capital costs can be slightly to significantly higher compared to open-ocean intake system costs, a preliminary life-cycle cost analysis shows significant cost saving over operating periods of 10 to 30. years. © 2013 Elsevier B.V.

  17. Integrated pretreatment with capacitive deionization for reverse osmosis reject recovery from water reclamation plant.

    Science.gov (United States)

    Lee, Lai Yoke; Ng, How Yong; Ong, Say Leong; Tao, Guihe; Kekre, Kiran; Viswanath, Balakrishnan; Lay, Winson; Seah, Harry

    2009-10-01

    Reverse osmosis (RO) reject recovery from the water reclamation process was demonstrated feasible using an integrated pretreatment scheme followed by the Capacitive Deionization (CDI) process. The RO reject had an average total dissolved solids (TDS) of 1276+/-166 mg/L. Water recovery of 85% with water quality comparable with the RO feed was achieved. Pretreatments using biological activated carbon (BAC) and BAC-ultrafiltration (UF) attained total organic carbon (TOC) removal efficiencies of 23.5+/-6.0% and 39.9+/-9.0%, respectively. Organics removal of RO reject was attributed to simultaneous adsorption and biodegradation in the BAC pretreatment, while further biodegradation in the submerged UF membrane tank provided additional organics removal. Membrane and CDI fouling was reduced by pH adjustment of the pretreated RO reject to approximately 6.5, which prolonged the CDI operation time by at least two times. The CDI process was able to achieve more than 88 and 87% TDS and ion removals, respectively, while PO(4)(3-) and TOC removals were at 52-81% and 50-63%, respectively. PMID:19700181

  18. Removal of ionic dyes from water by solvent extraction using reverse micelles.

    Science.gov (United States)

    Pandit, P; Basu, S

    2004-04-15

    Several methods (e.g., UV/H2O2 oxidation, adsorption, flocculation-precipitation) are normally employed to remove dye from water. A new technique based on liquid/liquid extraction using reverse micelles is proposed whereby recovery of solvent and reuse of dye is possible. Experiments were conducted by mixing a known quantity of dye in aqueous phase and solvent-containing surfactants in a simple mixer. The separation of solvent phase, containing encapsulated dye in reverse micelles, from aqueous phase due to gravity results in separation of dye from water. The removal of different ionic dyes (e.g., eosin yellow, methylene blue, malachite green, methyl orange, orange G) from aqueous phase in the presence of different cationic and anionic surfactants [e.g., sodium dodecylbenzene sulfonate, sodium bis(2-ethylhexyl) sulfosuccinate, hexadecyltrimethylammonium bromide, and cetyl pyridinium chloride] in different solvents (e.g., amyl alcohol, benzyl alcohol, methyl benzoate, and isooctane) were studied by conducting experiments. The percentage removal of dye from aqueous phase increases with the decrease in dye concentration or with the increase in surfactants concentration. Furthermore, the percentage COD removal of dye is increased with the increase in surfactant concentration. The nature of solvent has minimal effect on percentage removal of dye. The ratio of solventto aqueous phase volume required for the removal of dye decreases with the increase in surfactant concentration. It is possible to back-extract dye into aqueous phase and recover solvent by using counterionic surfactants. The separation of aqueous phase from the aqueous-phase solvent dispersion is faster for amyl alcohol as compared to benzyl alcohol and methyl benzoate. A theoretical model based on ion-exchange reaction between surfactants and dye is used to analyze the experimental data. PMID:15116851

  19. Mechanisms of Cytochrome C Extraction by Reverse Micelles

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The extraction of cytochrome C was carried out by means of phase transfer technique with three different reverse micellar systems, i.e., a CTAB micellar solution in n-butyl alcohol-chloroform(volume ratio 4∶1), an AOT micellar solution in isooctane and a SDSS-D2EHPA micellar solution in isooctane. The extraction mechanisms were studied. The results show that the extraction mechanisms for the same proteins with different types of reverse micellar systems can be distinct. The extraction of cytochrome C with CTAB and SDSS-D2EHPA reverse micellar systems are carried out according to the mechanism of electrostatic interaction. However, in the extraction of cytochrome C with the AOT reverse micellar system, the electrostatic interaction between the protein and the surfactant is not important.

  20. Pilot-Scale Investigation of Forward/Reverse Osmosis Hybrid System for Seawater Desalination Using Impaired Water from Steel Industry

    OpenAIRE

    Ali, Hanaa M.; Hanaa Gadallah; Ali, Sahar S.; Rania Sabry; Gadallah, A. G.

    2016-01-01

    This paper was focused on the investigation of a forward osmosis- (FO-) reverse osmosis (RO) hybrid process to cotreat seawater and impaired water from steel industry. By using this hybrid process, seawater can be diluted before desalination, hence reducing the energy cost of desalination, and simultaneously contaminants present in the impaired water are prevented from migrating into the product water through the FO and RO membranes. The main objective of this work was to investigate on pilot...

  1. Data on daily fluoride intake based on drinking water consumption prepared by household desalinators working by reverse osmosis process.

    Science.gov (United States)

    Karbasdehi, Vahid Noroozi; Dobaradaran, Sina; Esmaili, Abdolhamid; Mirahmadi, Roghayeh; Ghasemi, Fatemeh Faraji; Keshtkar, Mozhgan

    2016-09-01

    In this data article, we evaluated the daily fluoride contents in 20 household desalinators working by reverse osmosis (RO) process in Bushehr, Iran. The concentration levels of fluoride in inlet and outlet waters were determined by the standard SPADNS method using a spectrophotometer (M501 Single Beam Scanning UV/VIS, UK). The fluoride content in outlet waters were compared with EPA and WHO guidelines for drinking water. PMID:27508234

  2. UV-Vis spectral investigation of photophysical properties of a solvatochromic electron donor/acceptor dye within a reverse micelle domain

    Science.gov (United States)

    Sarkar, Amrita; Kedia, Niraja; Purkayastha, Pradipta; Bagchi, Sanjib

    2014-01-01

    The optical response of a solvatochromic dye, [(E)-3-(1-methyl-1H-indol-3-yl)-1-phenylprop-2-en-1-one], N1, has been studied in the AOT/n-heptane/water reverse micellar media using steady-state and time-resolved techniques. To this end variation in the photophysical properties of N1 have been systematically studied as a function of water pool size (w0). Micropolarity, microviscosity, and relative permittivity of the immediate microenvironment surrounding the probe has been estimated from the limiting values of the photophysical parameters of N1 at high w0. Information about the location of the dye in the reverse micellar media has been obtained using the observed results.

  3. Using microbial desalination cells to reduce water salinity prior to reverse osmosis

    KAUST Repository

    Mehanna, Maha

    2010-01-01

    A microbial desalination cell (MDC) is a new method to reduce the salinity of one solution while generating electrical power from organic matter and bacteria in another (anode) solution. Substantial reductions in the salinity can require much larger volumes of the anode solution than the saline water, but any reduction of salinity will benefit the energy efficiency of a downstream reverse osmosis (RO) desalination system. We investigated here the use of an MDC as an RO pre-treatment method using a new type of air-cathode MDC containing three equally sized chambers. A single cycle of operation using a 1 g L -1 acetate solution reduced the conductivity of salt water (5 g L-1 NaCl) by 43 ± 6%, and produced a maximum power density of 480 mW m-2 with a coulombic efficiency of 68 ± 11%. A higher concentration of acetate (2 g L-1) reduced solution conductivity by 60 ± 7%, and a higher salt concentration (20 g L-1 NaCl) reduced solution conductivity by 50 ± 7%. The use of membranes with increased ion exchange capacities further decreased the solution conductivity by 63 ± 2% (20 g L-1 NaCl). These results demonstrate substantial (43-67%) desalination of water is possible using equal volumes of anode solution and salt water. These results show that MDC treatment could be used to substantially reduce salt concentrations and thus energy demands for downstream RO processing, while at the same time producing electrical power. © 2010 The Royal Society of Chemistry.

  4. Evaluation of emerging contaminants in a drinking water treatment plant using electrodialysis reversal technology.

    Science.gov (United States)

    Gabarrón, S; Gernjak, W; Valero, F; Barceló, A; Petrovic, M; Rodríguez-Roda, I

    2016-05-15

    Emerging contaminants (EC) have gained much attention with globally increasing consumption and detection in aquatic ecosystems during the last two decades from ng/L to lower ug/L. The aim of this study was to evaluate the occurrence and removal of pharmaceutically active compounds (PhACs), endocrine disrupting chemicals (EDCs) and related compounds in a Drinking Water Treatment Plant (DWTP) treating raw water from the Mediterranean Llobregat River. The DWTP combined conventional treatment steps with the world's largest electrodialysis reversal (EDR) facility. 49 different PhACs, EDCs and related compounds were found above their limit of quantification in the influent of the DWTP, summing up to a total concentration of ECs between 1600-4200 ng/L. As expected, oxidation using chlorine dioxide and granular activated carbon filters were the most efficient technologies for EC removal. However, despite the low concentration detected in the influent of the EDR process, it was also possible to demonstrate that this process partially removed ionized compounds, thereby constituting an additional barrier against EC pollution in the product. In the product of the EDR system, only 18 out of 49 compounds were quantifiable in at least one of the four experimental campaigns, showing in all cases removals higher than 65% and often beyond 90% for the overall DWTP process. PMID:26894293

  5. Molecular Thermodynamic Modeling of Reverse Micelles and Water-in-Oil Microemulsions.

    Science.gov (United States)

    Lukanov, Boris; Firoozabadi, Abbas

    2016-04-01

    Surfactant aggregation plays an important role in a variety of chemical and biological nanoscale processes. On a larger scale, using small amounts of amphiphiles compared to large volumes of bulk-phase modifiers can improve the efficiency and reduce the environmental impact of many chemical and industrial processes. To model ternary mixtures of polar, nonpolar, and amphiphilic molecules, we develop a molecular thermodynamic theory for polydisperse water-in-oil (W/O) droplet-type microemulsions and reverse micelles based on global minimization of the Gibbs free energy of the system. The incorporation of size polydispersity into the theoretical formulation has a significant effect on the Gibbs free energy landscape and allows us to accurately predict micelle size distributions and micelle size variation with composition. Results are presented for two sample ionic surfactant/water/oil systems and compared with experimental data. By predicting the structural and compositional characteristics of w/o microemulsions, the molecular thermodynamic approach provides an important bridge between the modeling of ternary systems at the molecular and the macroscopic level. PMID:26919199

  6. Using reverse osmosis to remove natural organic matter from power plant makeup water

    International Nuclear Information System (INIS)

    A field-scale reverse osmosis (RO) system was used to remove salts and natural organic matter (NOM) from a surface water source. The RO membrane exhibited an NOM solution hydraulic permeability of 8.33 x 10-9 m x s-1 x kPa-1, about 6% less than the clean water value, over pressures ranging from 414 to 1 000 kPa (60 to 145 psi). The rejection of salt and NOM were greater than 98% and 99%, respectively. Under controlled laboratory conditions, greater than 99% mass recovery of NOM could be obtained. A small fraction of NOM was not recovered using hydrodynamic cleaning but could be recovered with chemical cleaning (NaOH wash solution). The mass recovered in the NaOH solution increased from 6% with increasing transmembrane pressures from 414 kPa to 1 000 kPa, respectively. This is consistent with fouling that results from an increase in solution flux, and a concomitant decrease in tangential crossflow velocity. (orig.)

  7. Reverse polarity capillary zone electrophoresis analysis of nitrate and nitrite in natural water samples

    International Nuclear Information System (INIS)

    This paper describes the application of reverse polarity capillary zone electrophoresis (RPCE) for rapid and accurate determination of nitrate and nitrite in natural water samples. Using hexamethonium bromide (HMB) as an electroosmotic flow modifier in a borate buffer at pH 9.2, the resolution of nitrate and nitrite was accomplished in less than 3 minutes. RPCE was compared with ion chromatographic (IC) and cadmium reduction flow injection analysis (Cd-FIA) methods which are the two most commonly used standard methods for the analysis of natural water samples for nitrate and nitrite. When compared with the ion chromatographic method for the determination of nitrate and nitrite, RPCE reduced analysis time, decreased detection limits by a factor of 10, cut laboratory wastes by more than two orders of magnitude, and eliminated interferences commonly associated with IC. When compared with the cadmium reduction method, RPCE had the advantage of simultaneous determination of nitrate and nitrite, could be used in the presence of various metallic ions that normally interfere in cadmium reduction, and decreased detection limits by a factor of 10

  8. Reverse flow injection spectrophotometric determination of thiram and nabam fungicides in natural water samples

    International Nuclear Information System (INIS)

    A reverse flow injection (rFI) spectrophotometric method is reported for determination of thiram and nabam fungicides in natural water samples. The method is based on the reduction of iron(III) in the presence of thiram/nabam in acidic medium at 60 degree C and formation of iron(II)-ferricyanide complex was measured at 790 nm. The limits of detection (3s blank) were 0.01 and 0.05 micro g mL1 for thiram and nabam respectively with a sample throughput of 60 h1. Calibration graphs were linear over the range of 0.02 - 8.0 micro g mL1 (R2 = 0.9999, n = 8) and 0.1 - 30 micro g mL1 (R2 = 0.9982, n = 10) for thiram and nabam with relative standard deviations (RSDs; n = 3) in the range of 0.8 - 1.6% respectively. Experimental parameters and potential interferences were examined. Thiram and nabam were determined in natural water samples using solid-phase extraction (SPE) procedure and recoveries were in the range of 93+-3 - 105+-2% and 87+-4 - 102+-3% respectively. The results obtained were not significantly different compared with a HPLC method. (author)

  9. Reverse osmosis integrity monitoring in water reuse: The challenge to verify virus removal - A review.

    Science.gov (United States)

    Pype, Marie-Laure; Lawrence, Michael G; Keller, Jurg; Gernjak, Wolfgang

    2016-07-01

    A reverse osmosis (RO) process is often included in the treatment train to produce high quality reuse water from treated effluent for potable purposes because of its high removal efficiency for salinity and many inorganic and organic contaminants, and importantly, it also provides an excellent barrier for pathogens. In order to ensure the continued protection of public health from pathogen contamination, monitoring RO process integrity is necessary. Due to their small sizes, viruses are the most difficult class of pathogens to be removed in physical separation processes and therefore often considered the most challenging pathogen to monitor. To-date, there is a gap between the current log credit assigned to this process (determined by integrity testing approved by regulators) and its actual log removal capability as proven in a variety of laboratory and pilot studies. Hence, there is a challenge to establish a methodology that more closely links to the theoretical performance. In this review, after introducing the notion of risk management in water reuse, we provide an overview of existing and potentially new RO integrity monitoring techniques, highlight their strengths and drawbacks, and debate their applicability to full-scale treatment plants, which open to future research opportunities. PMID:27128885

  10. Nanofiltration vs. reverse osmosis for the removal of emerging organic contaminants in water reuse

    KAUST Repository

    Yangali-Quintanilla, Victor

    2011-01-01

    Reverse osmosis (RO) in existing water reuse facilities is a water industry standard. However, that approach may be questioned taking into consideration that "tight" NF can be equal or "better" than RO. NF can achieve the same removals of RO membranes when dealing with emerging organic contaminants (pharmaceuticals, pesticides, endocrine disruptors and others). Experiments using 18 emerging contaminants were performed using membranes NF200 and NF90 at bench-scale units, and for a more complete study, results of NF and RO pilot and fullscale experiments where compared to our experimental results. The removal results showed that NF can remove many emerging contaminants. The average removal by tight NF was 82% for neutral contaminants and 97% for ionic contaminants. The average removal by RO was 85% for neutral contaminants and 99% for ionic contaminants. Aquifer recharge and recovery (ARR) followed by NF can effectively remove emerging contaminants with removals over 90% when loose NF membranes are used. © 2011 2011 Desalination Publications. All rights reserved.

  11. Selective removal of arsenic and monovalent ions from brackish water reverse osmosis concentrate.

    Science.gov (United States)

    Xu, Pei; Capito, Marissa; Cath, Tzahi Y

    2013-09-15

    Concentrate disposal and management is a considerable challenge for the implementation of desalination technologies, especially for inland applications where concentrate disposal options are limited. This study has focused on selective removal of arsenic and monovalent ions from brackish groundwater reverse osmosis (RO) concentrate for beneficial use and safe environmental disposal using in situ and pre-formed hydrous ferric oxides/hydroxides adsorption, and electrodialysis (ED) with monovalent permselective membranes. Coagulation with ferric salts is highly efficient at removing arsenic from RO concentrate to meet a drinking water standard of 10 μg/L. The chemical demand for ferric chloride however is much lower than ferric sulfate as coagulant. An alternative method using ferric sludge from surface water treatment plant is demonstrated as an efficient adsorbent to remove arsenic from RO concentrate, providing a promising low cost, "waste treat waste" approach. The monovalent permselective anion exchange membranes exhibit high selectivity in removing monovalent anions over di- and multi-valent anions. The transport of sulfate and phosphate through the anion exchange membranes was negligible over a broad range of electrical current density. However, the transport of divalent cations such as calcium and magnesium increases through monovalent permselective cation exchange membranes with increasing current density. Higher overall salt concentration reduction is achieved around limiting current density while higher normalized salt removal rate in terms of mass of salt per membrane area and applied energy is attained at lower current density because the energy unitization efficiency decreases at higher current density. PMID:23892312

  12. Unexpected increasing AOT trends over northwest Bay of Bengal in the early postmonsoon season

    Energy Technology Data Exchange (ETDEWEB)

    Kishcha, P.; Starobinets, B.; Long, Charles N.; Alpert, P.

    2012-12-13

    The main point of our study is that aerosol trends can be created by changes in meteorology without changes in aerosol source strength. Over the 10 year period 2000–2009, in October, Moderate Resolution Imaging Spectroradiometer (MODIS) showed strong increasing aerosol optical thickness (AOT) trends of approximately 14% yr-1 over northwest Bay of Bengal (BoB) in the absence of AOT trends over the east of the Indian subcontinent. This was unexpected because sources of anthropogenic pollution were located over the Indian subcontinent and aerosol transport from the Indian subcontinent to northwest BoB was carried out by prevailing winds. In October, winds over the east of the Indian subcontinent were stronger than winds over northwest BoB, which resulted in wind convergence and accumulation of aerosol particles over northwest BoB. Moreover, there was an increasing trend in wind convergence over northwest BoB. This led to increasing trends in the accumulation of aerosol particles over northwest BoB and, consequently, to strong AOT trends over this area. In contrast to October, November showed no increasing AOT trends over northwest BoB or the nearby Indian subcontinent. The lack of AOT trends over northwest BoB corresponds to a lack of trends in wind convergence in that region. Finally, December domestic heating by the growing population resulted in positive AOT trends of similar magnitude over land and sea. Our findings illustrate that in order to explain and predict trends in regional aerosol loading, meteorological trends should be taken into consideration together with changes in aerosol source strength.

  13. The Reaction between Bromine and the Water Dimer and the Highly Exothermic Reverse Reaction.

    Science.gov (United States)

    Li, Guoliang; Wang, Hui; Li, Qian-Shu; Xie, Yaoming; Schaefer, Henry F

    2016-01-15

    The entrance complex, transition state, and exit complex for the bromine atom plus water dimer reaction Br + (H2O)2 → HBr + (H2O)OH and its reverse reaction have been investigated using the CCSD(T) method with correlation consistent basis sets up to cc-pVQZ-PP. Based on the CCSD(T)/cc-pVQZ-PP results, the reaction is endothermic by 31.7 kcal/mol. The entrance complex Br⋯(H2O)2 is found to lie 6.5 kcal/mol below the separated reactants. The classical barrier lies 28.3 kcal/mol above the reactants. The exit complex HBr⋯(H2O)OH is bound by 6.0 kcal/mol relative to the separated products. Compared with the corresponding water monomer reaction Br + H2 O → HBr + OH, the second water molecule lowers the relative energies of the entrance complex, transition state, and exit complex by 3.0, 3.8, and 3.7 kcal/mol, respectively. Both zero-point vibrational energies and spin-orbit coupling effects make significant changes to the above classical energetics. Including both effects, the predicted energies relation to separated Br + (H2O)2 are -3.0 kcal/mol [Br···(H2O)2 ], 28.2 kcal/mol [transition state], 26.4 kcal/mol [HBr···(H2O)OH], and 30.5 kcal/mol [separated HBr + (H2O)OH]. The potential energy surface for the Br + (H2O)2 reaction is related to that for the valence isoelectronic Cl + (H2O)2 system but radically different from the F + (H2O)2 system. PMID:26040856

  14. Influence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on zinc electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Lehr, I.L. [Instituto de Ingenieria Electroquimica y Corrosion (INIEC), Departamento de Ingenieria Quimica, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina); Saidman, S.B., E-mail: ssaidman@criba.edu.ar [Instituto de Ingenieria Electroquimica y Corrosion (INIEC), Departamento de Ingenieria Quimica, Universidad Nacional del Sur, Av. Alem 1253, 8000 Bahia Blanca (Argentina)

    2012-03-01

    This work is a study of the electrodeposition of zinc onto SAE 4140 steel electrodes using solutions containing zinc sulfate and bis(2-ethylhexyl) sodium sulfosuccinate (AOT). The influence of different parameters such as electrolyte concentration, electrodeposition time and temperature on the morphology of the electrodeposits was analyzed. The deposits were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction. The variation of open circuit potential over time in chloride solutions was also evaluated. The nucleation-growth process and consequently the morphology of the electrodeposits are modified in the presence of AOT. The surfactant induces the formation of a porous deposit.

  15. Energy consumption in membrane capacitive deionization for different water recoveries and flow rates, and comparison with reverse osmosis

    NARCIS (Netherlands)

    Zhao, R.; Porada, S.; Biesheuvel, P.M.; Wal, van der A.

    2013-01-01

    Membrane capacitive deionization (MCDI) is a non-faradaic, capacitive technique for desalinating brackish water by adsorbing ions in charged porous electrodes. To compete with reverse osmosis, the specific energy consumption of MCDI needs to be reduced to less than 1 kWh per m3 of freshwater produce

  16. Reverse electrodialysis : Performance of a stack with 50 cells on the mixing of sea and river water

    NARCIS (Netherlands)

    Veerman, J.; Saakes, M.; Metz, S. J.; Harmsen, G. J.

    2009-01-01

    The purpose of reverse electrodialysis (RED) is to produce electricity upon the mixing of two solutions. We studied the power density (W/m(2)) and the energy efficiency (the amount of energy produced from specified volumes of river and sea water in relation to the thermodynamic maximum). With a stac

  17. Speech and Language Disorders in a Dialysis Encephalopathy Patient and the Effect of Desferrioxamine and Reverse-Osmosis Water Treatment.

    Science.gov (United States)

    Lehtihalmes, Matti; And Others

    Dialysis encephalopathy is a progressive neurological disorder occurring after long-term hemodialysis in some renal failure patients. Accumulation of aluminum in the brain is suspected as its cause, and the use of reverse osmosis of the dialysis water and administration of desferrioxamine to the patient have been successful in reducing the…

  18. Use of propidium monoazide in reverse transcriptase PCR to distinguish between infectious and noninfectious enteric viruses in water samples

    Science.gov (United States)

    Human enteric viruses can be present in untreated and inadequately treated drinking water. Molecular methods, such as the reverse transcriptase PCR (RT-PCR), can detect viral genomes in a few hours, but they cannot distinguish between infectious and noninfectious viruses. Since o...

  19. Dialysis water treated by reverse osmosis decreases the levels of C-reactive protein in uremic patients

    OpenAIRE

    Thomé F.S.; Senger M.; Garcez C.; Garcez J.; Chemello C.; Manfro R.C.

    2005-01-01

    Atherosclerosis is a major complication of chronic renal failure. Microinflammation is involved in atherogenesis and is associated with uremia and dialysis. The role of dialysate water contamination in inducing inflammation has been debated. Our aim was to study inflammatory markers in patients on chronic dialysis, before and 3 to 6 months after switching the water purification system from deionization to reverse osmosis. Patients had demographic, clinical and nutritional information collecte...

  20. Rejection of Emerging Organic Contaminants by Nanofiltration and Reverse Osmosis Membranes: Effects of Fouling, Modelling and Water Reuse

    OpenAIRE

    Yangali Quintanilla, V.

    2010-01-01

    The book contains a description of the presence of micropollutants (medicines, hormones, pesticides) in surface water and shows that conventional water treatment poorly removes micropollutants. Nanofiltration and reverse osmosis are more appropriate technologies; however removals can vary depending on the properties of compounds and types of membranes. Thus, quantification of removals is studied by means of multivariate data analysis techniques and more understanding of the separation of micr...

  1. DRINKING WATER FROM DESALINATION OF SEAWATER: OPTIMIZATION OF REVERSE OSMOSIS SYSTEM OPERATING PARAMETERS

    Directory of Open Access Journals (Sweden)

    MARWAN M. SHAMEL

    2006-12-01

    Full Text Available This paper reports on the use of pilot scale membrane separation system coupled with another pilot scale plate heat exchanger to investigate the possibilities of sweetening seawater from Telok Kalong Beach, Terengganu, Malaysia. Reverse osmosis (RO membrane of a surface area of 0.5 m2 was used during the experimental runs. Experiments were conducted at different transmembrane pressures (TMP ranged from 40 to 55 bars, operation temperature ranged from 35 to 45oC, feed concentration (TDS ranged from 34900 to 52500 ppm and cross flow velocities ranged from 1.4 to 2.1 m/s. The result show that the flux values increased linearly with TMP as well as sodium ion rejection. Permeate flux values increased proportionally with the temperature and the later effect was more significant at high pressures. The temperature changing has also influenced the rejection of sodium ion. The minerals content especially NaCl and total dissolved solid (TDS in the drinking water produced in this research are conforming to the standards of World Health Organization (WHO.

  2. Continuous capacitive deionization-electrodialysis reversal through electrostatic shielding for desalination and deionization of water

    Energy Technology Data Exchange (ETDEWEB)

    Dermentzis, Konstantinos [Technological Education Institute, T.E.I. of Kavala, School of Technological Applications, Department of Science, Laboratory of Chemical Technology and Electrochemistry, Agios Loucas, 65404 Kavala (Greece); Ouzounis, Konstantinos [Democritus University of Thrace, School of Engineering, Department of Environmental Engineering, Laboratory of Environmental Chemistry, 67100 Xanthi (Greece)

    2008-10-15

    We report a new concept for capacitive deionization with simple and cheap porous bipolar intermediate graphite electrodes which is operated continuously by constant or alternating polarity without any down time for electrode saturation, regeneration and rinsing steps and certainly without any permselective ion exchange membranes. The proposed process utilizes the advantages of the classical electrodeionization technologies combining them all to a unified continuous capacitive deionization-continuous electrodeionization-electrodialysis-electrodialysis reversal process. Separate and unchanged diluate and concentrate compartments are created in two modes, first by periodical charging/discharging the bipolar intermediate electrodes through a pulsating electric field and second by simultaneous charging/discharging them through a constant or pulsating electric field and electrostatic shielding. Because of coion permeation and the convenience of alternating the polarity without any negative impact on the deionization process, the new technique is less affected by the known membrane associated limitation, such as concentration polarization, limiting current density or scaling. The new electrochemical deionization technique is suitable for regeneration of ion exchange resins and production of high purity deionized water, removal of heavy metal ions from industrial effluents and desalination of brackish or seawater. (author)

  3. Modeling and Analysis of the Reverse Water Gas Shift Process for In-Situ Propellant Production

    Science.gov (United States)

    Whitlow, Jonathan E.

    2000-01-01

    This report focuses on the development of mathematical models and simulation tools developed for the Reverse Water Gas Shift (RWGS) process. This process is a candidate technology for oxygen production on Mars under the In-Situ Propellant Production (ISPP) project. An analysis of the RWGS process was performed using a material balance for the system. The material balance is very complex due to the downstream separations and subsequent recycle inherent with the process. A numerical simulation was developed for the RWGS process to provide a tool for analysis and optimization of experimental hardware, which will be constructed later this year at Kennedy Space Center (KSC). Attempts to solve the material balance for the system, which can be defined by 27 nonlinear equations, initially failed. A convergence scheme was developed which led to successful solution of the material balance, however the simplified equations used for the gas separation membrane were found insufficient. Additional more rigorous models were successfully developed and solved for the membrane separation. Sample results from these models are included in this report, with recommendations for experimental work needed for model validation.

  4. Determination and occurrence of organic micropollutants in reverse osmosis treatment for advanced water reuse.

    Science.gov (United States)

    Gomez, Veronica; Majamaa, Katariina; Pocurull, Eva; Borrull, Francesc

    2012-01-01

    The growing demand on water resources has increased the interest in wastewater reclamation for multiple end-use applications such as indirect and direct potable reuse. In these applications, the removal of organic micropollutants is of a greater concern than in conventional wastewater treatment. This article presents a collection of data of trace organic micropollutants in an urban wastewater treatment plant (WWTP) in North East Spain using reverse osmosis (RO) membrane treatment. The RO rejection values of the organic molecules studied with a wide range of solute size and hydrophobicity were determined. Several chromatographic methods monitoring different endocrine disrupting chemicals (EDCs), pharmaceuticals and personal care products (PPCPs) were used. Results indicated that secondary effluents from this Spanish WWTP contained most of the studied organic compounds indicating incomplete removal of organics in the conventional treatment of the plant. However, the rejection of most micropollutants was high for all three RO membrane types (low energy, high rejection, fouling resistant) tested. It was observed that some selected micropollutants were less efficiently removed (e.g. the small and polar and the more hydrophobic) and the molecular weight and membrane material influenced removal efficiencies. PMID:22678201

  5. Effects of surface coating process conditions on the water permeation and salt rejection properties of composite polyamide reverse osmosis membranes

    KAUST Repository

    Louie, Jennifer Sarah

    2011-02-01

    The application of polymer surface coatings to improve the fouling resistance of reverse osmosis membranes tends to increase flow resistance across the membrane. This paper presents a systematic analysis on how membrane properties and performance are impacted by the coating process steps, and investigates how such effects could contribute to lower water flux. On one hand, simply pre-soaking dry aromatic polyamide composite membranes in aliphatic alcohols results in a significant increase in water flux, which is attributed to wetting of pores in the selective polyamide layer and to changes in the polymer structure. This flux increase was not readily reversible, based on a 300-h water permeation test. Conversely, drying a wetted membrane led to a decrease in water flux, which we hypothesize is caused by increased interchain hydrogen-bonding in the selective layer. This drop in water flux was not permanent; higher flux was observed if the same wetted/dried membrane was then re-soaked in ethanol prior to the water permeation experiment. An ethanol pre-soaking step also increased water flux of a PEBAX-coated membrane by nearly 70%. In contrast to the reduction in water flux caused by the specific treatment sequence of ethanol-swelling followed by drying, this same sequence actually increased gas transport. The eight- to ten-fold increase in Knudsen diffusion-based gas permeance after this pre-treatment was attributed to an increase in the number or size of membrane defects. © 2010 Elsevier B.V.

  6. Handling concentrated water with reverse osmosis technology and economize water%反渗透工艺处理浓水节约水资源

    Institute of Scientific and Technical Information of China (English)

    张秀玲; 杨潘溪; 吴华

    2012-01-01

    反渗透工艺作为一种高效、清洁的脱盐技术在各行各业中广泛应用,但是在生产过程中实际产水率70%左右,会有大约占总进水量30%左右的浓水排放掉,这一点在水资源日趋紧缺的今天造成了水资源的极大浪费,而且也严重污染了环境。现简要介绍对反渗透浓水采用反渗透技术和设备来进一步处理,可以使反渗透浓水的回收率达到80%-85%,回收水可以再利用,节约了水资源。%As a kind of high efficient, clean desalting technology, reverse osmosis technology is widely applied in all walks of life. However, actual rate of out flow is about 70% in production process, the rest 30% of the total water inflow concentrated water is drained off which not only causes a tremendous waste of water resources today when water resource is in short, but also it pollutes environment seriously. This paper briefly introduces adopting reverse osmosis technology and equipments to reverse osmosis concentrated water, which can make the rate of reverse osmosis concentrated water reach 80%-85%, recycled water can be reused and saving water resources.

  7. [Selective detection of viable pathogenic bacteria in water using reverse transcription quantitative PCR].

    Science.gov (United States)

    Lin, Yi-Wen; Li, Dan; Wu, Shu-Xu; He, Miao; Yang, Tian

    2012-11-01

    A reverse transcription q quantitative PCR (RT-qPCR) assay method was established, which can quantify the copy numbers of RNA in pathogenic bacteria of E. coli and Enterococcus faecium. The results showed that cDNA was generated with the RT-PCR reagents, target gene was quantified with the qPCR, the copy numbers of RNA were stable at about 1 copies x CFU(-1) for E. coli and 7.98 x 10(2) copies x CFU(-1) for Enterococcus faecium respectively during the stationary grow phase for the both indicator bacteria [E. coli (6-18 h) and Enterococcus faecium (10-38 h)]. The established RT-qPCR method can quantify the numbers of viable bacteria through detecting bacterial RNA targets. Through detecting the heat-treated E. coli and Enterococcus faecium by three methods (culture method, qPCR, RT-qPCR), we found that the qPCR and RT-qPCR can distinguish 1.43 lg copy non-viable E. coli and 2.5 lg copy non-viable Enterococcus faecium. These results indicated that the established methods could effectively distinguish viable bacteria from non-viable bacteria. Finally we used this method to evaluate the real effluents of the secondary sedimentation of wastewater treatment plant (WWTP), the results showed that the correlation coefficients (R2) between RT-qPCR and culture method were 0.930 (E. coli) and 0.948 (Enterococcus faecium), and this established RT-PCR method can rapidly detect viable pathogenic bacteria in genuine waters. PMID:23323443

  8. A comparison of surface water natural organic matter in raw filtered water samples, XAD, and reverse osmosis isolates

    Science.gov (United States)

    Maurice, P.A.; Pullin, M.J.; Cabaniss, S.E.; Zhou, Q.; Namjesnik-Dejanovic, K.; Aiken, G.R.

    2002-01-01

    This research compared raw filtered waters (RFWs), XAD resin isolates (XAD-8 and XAD-4), and reverse osmosis (RO) isolates of several surface water samples from McDonalds Branch, a small freshwater fen in the New Jersey Pine Barrens (USA). RO and XAD-8 are two of the most common techniques used to isolate natural organic matter (NOM) for studies of composition and reactivity; therefore, it is important to understand how the isolates differ from bulk (unisolated) samples and from one another. Although, any comparison between the isolation methods needs to consider that XAD-8 is specifically designed to isolate the humic fraction, whereas RO concentrates a broad range of organic matter and is not specific to humics. The comparison included for all samples: weight average molecular weight (Mw), number average molecular weight (Mn), polydispersity (??), absorbance at 280nm normalized to moles C (??280) (RFW and isolates); and for isolates only: elemental analysis, % carbon distribution by 13C NMR, and aqueous FTIR spectra. As expected, RO isolation gave higher yield of NOM than XAD-8, but also higher ash content, especially Si and S. Mw decreased in the order: RO>XAD-8>RFW>XAD-4. The Mw differences of isolates compared with RFW may be due to selective isolation (fractionation), or possibly in the case of RO to condensation or coagulation during isolation. 13C NMR results were roughly similar for the two methods, but the XAD-8 isolate was slightly higher in 'aromatic' C and the RO isolate was slightly higher in heteroaliphatic and carbonyl C. Infrared spectra indicated a higher carboxyl content for the XAD-8 isolates and a higher ester:carboxyl ratio for the RO isolates. The spectroscopic data thus are consistent with selective isolation of more hydrophobic compounds by XAD-8, and also with potential ester hydrolysis during that process, although further study is needed to determine whether ester hydrolysis does indeed occur. Researchers choosing between XAD and RO

  9. Small angle X-ray scattering studies to access the influence of bovine serum albumin (BSA) and carbonic anhydrase (Boca) on the size and interaction among Aerosol-O T reversed micelles as a function of the micellar hydration degree

    International Nuclear Information System (INIS)

    Full text: Reversed micelles (RMs) of AOT (sodium bis-2-ethylhexyl sulfosuccinate) has constitute an efficient system to investigate membrane interaction and physical chemical behavior of short biologically active peptides, proteins and enzymes in water controlled environment and apolar medium. Information may be obtained from protein-membrane interaction, including solubilization, binding location, conformational changes, activity size droplet-dependent, and changes in the properties of RM environment, useful in studies in biocatalysis and bioseparation systems [1]. In this work, changes in the structural features and interactive forces among AOT RMs in hexane were monitored in several stages of micellar hydration W (= [buffer]/[0.1M AOT]), and in the presence of BSA (66.5 kDa) and BCA (30 Kda), by SAXS. The interactive forces between the RMs with proteins were analyzed within the framework of repulsion and attractive interaction potentials through the pairing stick hardsphere (PSHS) model [2]. In this way, the spherical core radius to the system of pure AOT RMs at W = 4, 10, 20 and 30 were respectively 15, 22, 33 and 43 A (20% of polydispersity), evaluated from the particle form factor P(q) modeling [1]. The PSHS analysis from SAXS curves of AOT RMs with BSA and BCA at smaller droplets size of 4 and 10, showed, respectively, an interplay between attractive and repulsive interactions between the micelles (attractive component in S(q) was predominant) with the preservation of the discrete RM radius in the presence of protein. On the other hand, for protein confined in the bigger RM droplet size with W=30, the attractive inter micellar forces were of minor importance for BSA and the appearing of a predominant repulsive hard sphere component in SAXS curves accompanied by a decreasing of the micellar radius to 36 A were detected. For BCA, however, at higher W (30), a phase separation was observed probably associated to the formation of unstable large BCA aggregates

  10. Rapid Detection of Enteroviruses in Small Volumes of Natural Waters by Real-Time Quantitative Reverse Transcriptase PCR

    OpenAIRE

    Fuhrman, Jed A.; Liang, Xiaolin; Noble, Rachel T.

    2005-01-01

    Despite viral contamination of recreational waters, only bacterial, not viral, indicators are monitored routinely, due to a lack of rapid and cost-effective assays. We used negatively charged filters to capture enteroviruses from seawater and freshwater. Viral RNA was extracted using a commercial kit, and the viruses were quantified by real-time quantitative reverse transcriptase PCR (qRT-PCR). Poliovirus (6.6 to 330,000 virus particles/ml) was added to samples from watersheds in Los Angeles,...

  11. Hydrogen production from inexhaustible supplies of fresh and salt water using microbial reverse-electrodialysis electrolysis cells.

    Science.gov (United States)

    Kim, Younggy; Logan, Bruce E

    2011-09-27

    There is a tremendous source of entropic energy available from the salinity difference between river water and seawater, but this energy has yet to be efficiently captured and stored. Here we demonstrate that H(2) can be produced in a single process by capturing the salinity driven energy along with organic matter degradation using exoelectrogenic bacteria. Only five pairs of seawater and river water cells were sandwiched between an anode, containing exoelectrogenic bacteria, and a cathode, forming a microbial reverse-electrodialysis electrolysis cell. Exoelectrogens added an electrical potential from acetate oxidation and reduced the anode overpotential, while the reverse electrodialysis stack contributed 0.5-0.6 V at a salinity ratio (seawater:river water) of 50. The H(2) production rate increased from 0.8 to 1.6 m(3)-H(2)/m(3)-anolyte/day for seawater and river water flow rates ranging from 0.1 to 0.8 mL/ min. H(2) recovery, the ratio of electrons used for H(2) evolution to electrons released by substrate oxidation, ranged from 72% to 86%. Energy efficiencies, calculated from changes in salinities and the loss of organic matter, were 58% to 64%. By using a relatively small reverse electrodialysis stack (11 membranes), only ~1% of the produced energy was needed for pumping water. Although Pt was used on the cathode in these tests, additional tests with a nonprecious metal catalyst (MoS(2)) demonstrated H(2) production at a rate of 0.8 m(3)/m(3)/d and an energy efficiency of 51%. These results show that pure H(2) gas can efficiently be produced from virtually limitless supplies of seawater and river water, and biodegradable organic matter. PMID:21930953

  12. Hydrogen production from inexhaustible supplies of fresh and salt water using microbial reverse-electrodialysis electrolysis cells

    KAUST Repository

    Kim, Y.

    2011-09-19

    There is a tremendous source of entropic energy available from the salinity difference between river water and seawater, but this energy has yet to be efficiently captured and stored. Here we demonstrate that H(2) can be produced in a single process by capturing the salinity driven energy along with organic matter degradation using exoelectrogenic bacteria. Only five pairs of seawater and river water cells were sandwiched between an anode, containing exoelectrogenic bacteria, and a cathode, forming a microbial reverse-electrodialysis electrolysis cell. Exoelectrogens added an electrical potential from acetate oxidation and reduced the anode overpotential, while the reverse electrodialysis stack contributed 0.5-0.6 V at a salinity ratio (seawater:river water) of 50. The H(2) production rate increased from 0.8 to 1.6 m(3)-H(2)/m(3)-anolyte/day for seawater and river water flow rates ranging from 0.1 to 0.8 mL/ min. H(2) recovery, the ratio of electrons used for H(2) evolution to electrons released by substrate oxidation, ranged from 72% to 86%. Energy efficiencies, calculated from changes in salinities and the loss of organic matter, were 58% to 64%. By using a relatively small reverse electrodialysis stack (11 membranes), only ~1% of the produced energy was needed for pumping water. Although Pt was used on the cathode in these tests, additional tests with a nonprecious metal catalyst (MoS(2)) demonstrated H(2) production at a rate of 0.8 m(3)/m(3)/d and an energy efficiency of 51%. These results show that pure H(2) gas can efficiently be produced from virtually limitless supplies of seawater and river water, and biodegradable organic matter.

  13. Dialysis water treated by reverse osmosis decreases the levels of C-reactive protein in uremic patients

    Directory of Open Access Journals (Sweden)

    Thomé F.S.

    2005-01-01

    Full Text Available Atherosclerosis is a major complication of chronic renal failure. Microinflammation is involved in atherogenesis and is associated with uremia and dialysis. The role of dialysate water contamination in inducing inflammation has been debated. Our aim was to study inflammatory markers in patients on chronic dialysis, before and 3 to 6 months after switching the water purification system from deionization to reverse osmosis. Patients had demographic, clinical and nutritional information collected and blood drawn for determination of albumin, ferritin, C-reactive protein (CRP, interleukin-6, and tumor necrosis factor-alpha in both situations. Acceptable levels of water purity were less than 200 colony-forming units of bacteria and less than 1 ng/ml of endotoxin. Sixteen patients died. They had higher median CRP (26.6 vs 11.2 mg/dl, P = 0.007 and lower median albumin levels (3.1 vs 3.9 g/l, P < 0.05 compared to the 31 survivors. Eight patients were excluded because of obvious inflammatory conditions. From the 23 remaining patients (mean age ± SD: 51.3 ± 13.9 years, 18 had a decrease in CRP after the water treatment system was changed. Overall, median CRP was lower with reverse osmosis than with deionization (13.2 vs 4.5 mg/l, P = 0.022, N = 23. There was no difference in albumin, cytokines, subjective global evaluation, or clinical and biochemical parameters. In conclusion, uremic patients presented a clinically significant reduction in CRP levels when dialysate water purification system switched from deionization to reverse osmosis. It is possible that better water treatments induce less inflammation and eventually less atherosclerosis in hemodialysis patients.

  14. REVERSE MICROEMULSION OF IGEPAL Co-720 SYSTEM AS MICROREACTOR FOR CdS SYNTHESIS

    Directory of Open Access Journals (Sweden)

    Fitria Rahmawati

    2016-08-01

    Full Text Available A Research on CdS synthesis in reverse microemulsion of Igepal CO-720 system has been conducted at various weight ratio of water to surfactant. Igepal CO-720 naturally forms oil in water (o/w emulsion type due to its high HLB (Hydrophilic -Lipophilic Balance value. Therefore, in this research the Igepal CO-720 system was inversed into water in oil (w/o system before it was used as microreactor for CdS synthesis. As comparison, a system of AOT (Aerosol OT; sodium bis (2-ethylhexyl sulfosuccinate which is naturally w/o system was also used as microreactor for CdS synthesis. The prepared CdS was analyzed by X-ray diffraction for crystal identification, scanning electron microscope for morphological analysis, UV-Vis for absorption edge determination and photoelectrochemical testing for photoactivity. The results show that the Igepal CO -720 system can be inverted into w/o system and can be used as microreactor for CdS synthesis. The prepared CdS is in nanosize with the average diameter of 2.517 ± 0.014 nm and the average gap energy of 3.805 ± 0.178 eV. The prepared CdS in Igepal CO-720 system has less regular form in comparison with morphology of the prepared CdS in AOT system. As the ω values decreases the particle diameter decreases, the gap energy increases and the % IPCE increases. It indicates that high surfactant concentration allows small size micelles formation and produced smaller CdS particle that has high surface area and therefore provide higher photocatalytic activity which was indicated by high value of its % IPCE.

  15. Electrical, optical, and material characterizations of blue InGaN light emitting diodes submitted to reverse-bias stress in water vapor condition

    International Nuclear Information System (INIS)

    In this paper, we investigate degradation of InGaN/GaN light emitting diodes (LEDs) under reverse-bias operations in water vapor and dry air. To examine failure origins, electrical characterizations including current-voltage, breakdown current profiles, optical measurement, and multiple material analyses were performed. Our findings indicate that the diffusion of indium atoms in water vapor can expedite degradation. Investigation of reverse-bias stress can help provide insight into the effects of water vapor on LEDs

  16. Thermodynamics of the sorption of water-soluble vitamins in reverse-phase high performance liquid chromatography

    Science.gov (United States)

    Chirkin, V. A.; Karpov, S. I.; Selemenev, V. F.

    2012-12-01

    The thermodynamics of the sorption of certain water-soluble vitamins on a C18 reverse phase from water-acetonitrile solutions of different compositions is studied. The thermodynamic characteristics of the investigated chromatographic systems are calculated. The dependences of standard molar enthalpy and changes in entropy when the sorbate transfers from the bulk solution to the surface layer on the concentration of the organic component in the mobile phase are analyzed. The boundaries for applying the main retention models describing the sorption of the investigated compounds are discussed.

  17. Use of a self-assembling organogel as a reverse template in the preparation of imprinted porous polymer films.

    Science.gov (United States)

    Tan, Grace; Singh, Mohit; He, Jibao; John, Vijay T; McPherson, Gary L

    2005-09-27

    The concept of reverse templating of an organogel to form imprinted porous divinylbenzene polymer films with submicrometer channels is demonstrated. The organogel comprising a 1:1 molar ratio of two organogelators, that is, bis(2-ethylhexyl) sodium sulfosuccinate and 4-chlorophenol, was formed in divinylbenzene. The gel was cast as a thin film before UV polymerization of the solvent, and the organogelators were later removed by simple washing with water and isooctane. The integrity of the fiber bundles of the organogel was preserved during polymerization, and an exact hollow replica was obtained after the organogelators were leached away. It is easily possible to imprint gel fiber bundle structures into polymeric films through this technique. The gel can also be formed on macroporous substrates to yield supported thin porous polymeric films. With the incorporation of functional nanoparticles in AOT inverse micelles and hence the organogel, nanoparticle-containing porous polymer films exhibiting luminescence or magnetic properties are envisioned. PMID:16171368

  18. Extraction of monoclonal antibodies (IgG1) using anionic and anionic/nonionic reverse micelles.

    Science.gov (United States)

    George, Daliya A; Stuckey, David C

    2010-01-01

    Purification schemes for antibody production based on affinity chromatography are trying to keep pace with increases in cell culture expression levels and many current research initiatives are focused on finding alternatives to chromatography for the purification of Monoclonal antibodies (MAbs). In this article, we have investigated an alternative separation technique based on liquid-liquid extraction called the reverse micellar extraction. We extracted MAb (IgG1) using reverse micelles of an anionic surfactant, sodium bis 2-ethyl-hexyl sulfosuccinate (AOT) and a combination of anionic (AOT) and nonionic surfactants (Brij-30, Tween-85, Span-85) using isooctane as the solvent system. The extraction efficiency of IgG1 was studied by varying parameters, such as pH of the aqueous phase, cation concentration, and type and surfactant concentration. Using the AOT/Isooctane reverse micellar system, we could achieve good overall extraction of IgG1 (between 80 and 90%), but only 30% of the bioactivity of IgG1 could be recovered at the end of the extraction by using its binding to affinity chromatography columns as a surrogate measure of activity. As anionic surfactants were suspected as being one of the reasons for the reduced activity, we decided to combine a nonionic surfactant with an anionic surfactant and then study its effect on the extraction efficiency and bioactivity. The best results were obtained using an AOT/Brij-30/Isooctane reverse micellar system, which gave an overall extraction above 90 and 59% overall activity recovery. An AOT/Tween-85/Isooctane reverse micellar system gave an overall extraction of between 75 and 80% and overall activity recovery of around 40-45%. The results showed that the activity recovery of IgG1 can be significantly enhanced using different surfactant combination systems, and if the recovery of IgG1 can be further enhanced, the technique shows considerable promise for the downstream purification of MAbs. PMID:20665658

  19. CTAB/water/chloroform reverse micelles: a closed or open association model?

    Czech Academy of Sciences Publication Activity Database

    Klíčová, L.; Šebej, P.; Štacko, P.; Filippov, Sergey K.; Bogomolova, Anna; Padilla, M.; Klán, P.

    2012-01-01

    Roč. 28, č. 43 (2012), s. 15185-15192. ISSN 0743-7463 R&D Projects: GA ČR GAP108/12/0640 Institutional support: RVO:61389013 Keywords : CTAB * reverse micelles * AFM Subject RIV: CD - Macromolecular Chemistry Impact factor: 4.187, year: 2012

  20. Unmanned Water Craft Identification and Adaptive Control in Low-Speed and Reversing Regions

    DEFF Research Database (Denmark)

    Theisen, Lukas Roy Svane; Galeazzi, Roberto; Blanke, Mogens

    This paper treats L1 adaptive hovering control of an unmanned surface vehicle in a station-keeping mode where a region of zero control authority and under-actuation are main challenges. Low-speed and reversing dynamics are identied from full scale sea trials, and parameter uncertainty is estimated...

  1. Synthesis by reverse microemulsion of nano structured ferrite to be utilized in hydrogen production by water

    International Nuclear Information System (INIS)

    Micelle and reverse micelle microemulsions can be favourably utilized in producing nano sized particles. The paper reports a general description of microemulsions systems, as well as their application in materials synthesis. By using one of the described methods, nano structured manganese ferrite, to be utilized in hydrogen production. was synthesized and the produced material was characterized in terms of morphological, microstructure and thermal properties

  2. Development of STI/AOT optimization methodology and an application to the AFWPs with adverse effects

    International Nuclear Information System (INIS)

    Adverse effects caused by the surveillance test for the components of nuclear power plant involve plant transients, unnecessary wear, burden on licensee's time, and the radiation exposure to personnel along with the characteristics of each component. The optimization methodology of STI and AOT has been developed and applied to AFWPs of a reference plant. The approach proposed in this paper consists of the results in minimal mean unavailability of the two-out-of-four system with adverse effects are analytically calculated for the example system. The surveillance testing strategy are given by the sequential test, the staggered test and the train staggered test, which is a mixed test scheme. In the system level, the sensitivity analyses for the STI and AOT, are performed for the measure of the system unavailability of the top event in the fault tree developed for the example system. This methodology may contribute to establishing the basis for the risk-based regulations. (author)

  3. Sulfonsuccinate (AOT Capped Pure and Mn-Doped CdS Nanoparticles

    Directory of Open Access Journals (Sweden)

    D. Venkatesan

    2012-01-01

    Full Text Available CdS nanoparticles and thin films are well known for their excellent semiconducting properties. When transition metal ions are doped into the CdS, it exhibits magnetic properties in addition to semiconducting properties and they are termed as dilute magnetic semiconductors (DMSs. In this paper, we discuss the preparation of sodium bis(2-ethylhexyl sulfonsuccinate (AOT capped CdS nanoparticles and thin films doped with magnetic impurity Mn. Sodium bis(2-ethulexyl sulfonsuccinate (AOT, capping agent promotes the uniform formation of nanoparticles. Optical characterizations are made using the UV-Vis spectrometer, PL, and FTIR. XRD shows the hexagonal structure of the CdS. SEM images and EDS measurements were made for the thin films. EPR shows the clear hyperfine lines corresponding to Mn2+ ion in the CdS nanoparticles.

  4. Spatiotemporal Spectral Variations of AOT in India’s EEZ over Arabian Sea: Validation of OCM-II

    Directory of Open Access Journals (Sweden)

    C. P. Simha

    2012-01-01

    Full Text Available We report the results of sun-photometric measurements of Aerosol Optical Thickness (AOT in India’s Exclusive Economic Zone (EEZ over the Arabian Sea along with synchronous Ocean Color Monitor (OCM-II derived AOT estimates during December 12, 2009–January 10, 2010. Relatively higher values of Angstrom exponent (α around 1.2 near coast and 0.2–0.8 in the India’s EEZ, observed during the cruise period, indicate the presence of smaller particles near the coast due to anthropogenic activities; and larger particles in the India’s EEZ due to advection of pollutants from Indian subcontinent via long-range transport. Results related to α and its derivative reveal four different aerosol types (urban-industrial, desert-dust, clean-marine, and mixed-type with varying fraction during the study period. Surface radiative forcing due to aerosols is found to be 20 W/m2 over India’s EEZ. OCM-derived AOTs showed good corroboration with in situ measurements with a correlation coefficient of about 0.95. A reasonably good correlation was also observed between AOT and wind speed (R = 0.6; AOT and relative humidity (R = 0.58. The concurrent MODIS AOT data also agree well with those observed by the OCEANSAT (OCM-II satellite during the campaign period.

  5. Autoregressive spatially varying coefficients model for predicting daily PM2.5 using VIIRS satellite AOT

    Science.gov (United States)

    Schliep, E. M.; Gelfand, A. E.; Holland, D. M.

    2015-12-01

    There is considerable demand for accurate air quality information in human health analyses. The sparsity of ground monitoring stations across the United States motivates the need for advanced statistical models to predict air quality metrics, such as PM2.5, at unobserved sites. Remote sensing technologies have the potential to expand our knowledge of PM2.5 spatial patterns beyond what we can predict from current PM2.5 monitoring networks. Data from satellites have an additional advantage in not requiring extensive emission inventories necessary for most atmospheric models that have been used in earlier data fusion models for air pollution. Statistical models combining monitoring station data with satellite-obtained aerosol optical thickness (AOT), also referred to as aerosol optical depth (AOD), have been proposed in the literature with varying levels of success in predicting PM2.5. The benefit of using AOT is that satellites provide complete gridded spatial coverage. However, the challenges involved with using it in fusion models are (1) the correlation between the two data sources varies both in time and in space, (2) the data sources are temporally and spatially misaligned, and (3) there is extensive missingness in the monitoring data and also in the satellite data due to cloud cover. We propose a hierarchical autoregressive spatially varying coefficients model to jointly model the two data sources, which addresses the foregoing challenges. Additionally, we offer formal model comparison for competing models in terms of model fit and out of sample prediction of PM2.5. The models are applied to daily observations of PM2.5 and AOT in the summer months of 2013 across the conterminous United States. Most notably, during this time period, we find small in-sample improvement incorporating AOT into our autoregressive model but little out-of-sample predictive improvement.

  6. Water in oil microemulsions as reaction media for a Diels-Alder reaction between N-ethylmaleimide and cyclopentadiene

    NARCIS (Netherlands)

    Engberts, JBFN; Fernandez, E; Garcia-Rio, L; Leis, J.R.

    2006-01-01

    The Diels-Alder reaction between N-ethylmaleimide and cyclopentadiene in water/AOT/isooctane microemulsions, where AOT denotes sodium bis(2-ethylhexyl) sulfosuccinate, was studied. The rate of the reaction was found to be higher than that obtained in pure isooctane, irrespective of the particular mi

  7. Effect of Confinement on the Properties of Sequestered Mixed Polar Solvents: Enzymatic Catalysis in Nonaqueous 1,4-Bis-2-ethylhexylsulfosuccinate Reverse Micelles.

    Science.gov (United States)

    Durantini, Andres M; Falcone, R Dario; Silber, Juana J; Correa, N Mariano

    2016-06-01

    The influence of different glycerol, N,N-dimethylformamide (DMF) and water mixtures encapsulated in 1,4-bis-2-ethylhexylsulfosuccinate (AOT)/n-heptane reverse micelles (RMs) on the enzymatic hydrolysis of 2-naphthyl acetate by α-chymotrypsin is demonstrated. In the case of the mixtures with DMF and protic solvents it has been previously shown, using absorption, emission and dynamic light-scattering techniques, that solvents are segregated inside the polar core of the RMs. Protic solvents anchor to the AOT, whereas DMF locates to the polar core of the aggregate. Thus, DMF not only helps to solubilize the hydrophobic substrate, increasing its effective concentrations but surprisingly, it does not affect the enzyme activity. The importance of ensuring the presence of RMs, encapsulation of the polar solvents and the corrections by substrate partitioning in order to obtain reliable conclusions is highlighted. Moreover, the effect of a constrained environment on solvent-solvent interactions in homogenous media and its impact on the use of RMs as nanoreactors is stressed. PMID:26891863

  8. Layerwise decomposition of water dynamics in reverse micelles: A simulation study of two-dimensional infrared spectrum

    Science.gov (United States)

    Biswas, Rajib; Furtado, Jonathan; Bagchi, Biman

    2013-10-01

    We present computer simulation study of two-dimensional infrared spectroscopy (2D-IR) of water confined in reverse micelles (RMs) of various sizes. The present study is motivated by the need to understand the altered dynamics of confined water by performing layerwise decomposition of water, with an aim to quantify the relative contributions of different layers water molecules to the calculated 2D-IR spectrum. The 0-1 transition spectra clearly show substantial elongation, due to inhomogeneous broadening and incomplete spectral diffusion, along the diagonal in the surface water layer of different sized RMs. Fitting of the frequency fluctuation correlation functions reveal that the motion of the surface water molecules is sub-diffusive and indicate the constrained nature of their dynamics. This is further supported by two peak nature of the angular analogue of van Hove correlation function. With increasing system size, the water molecules become more diffusive in nature and spectral diffusion almost completes in the central layer of the larger size RMs. Comparisons between experiments and simulations establish the correspondence between the spectral decomposition available in experiments with the spatial decomposition available in simulations. Simulations also allow a quantitative exploration of the relative role of water, sodium ions, and sulfonate head groups in vibrational dephasing. Interestingly, the negative cross correlation between force on oxygen and hydrogen of O-H bond in bulk water significantly decreases in the surface layer of each RM. This negative cross correlation gradually increases in the central water pool with increasing RMs size and this is found to be partly responsible for the faster relaxation rate of water in the central pool.

  9. The Development of a Renewable-Energy-Driven Reverse Osmosis System for Water Desalination and Aquaculture Production

    Institute of Scientific and Technical Information of China (English)

    Clark C K Liu

    2013-01-01

    Water and energy are closely linked natural resources-the transportation, treatment, and distribution of water depends on low-cost energy;while power generation requires large volumes of water. Seawater desalination is a mature technology for increasing freshwater supply, but it is essentially a trade of energy for freshwater and is not a viable solution for regions where both water and energy are in short supply. This paper discusses the development and application of a renewable-energy-driven reverse osmosis (RO) system for water desalination and the treatment and reuse of aquaculture wastewater. The system consists of (1) a wind-driven pumping subsystem, (2) a pressure-driven RO membrane desalination subsystem, and (3) a solar-driven feedback control module. The results of the pilot experiments indicated that the system, operated under wind speeds of 3 m s-1 or higher, can be used for brackish water desalination by reducing the salinity of feedwater with total dissolved solids (TDS) of over 3 000 mg L-1 to product water or permeate with a TDS of 200 mg L-1 or less. Results of the pilot experiments also indicated that the system can remove up to 97%of the nitrogenous wastes from the fish pond effluent and can recover and reuse up to 56%of the freshwater supply for fish pond operation.

  10. Reversal of acidification in upland waters of the English Lake District

    Energy Technology Data Exchange (ETDEWEB)

    Tipping, E.; Carrick, T.R.; Hurley, M.A.; James, J.B.; Lawlor, A.J.; Lofts, S.; Rigg, E.; Sutcliffe, D.W.; Woof, C. [Institute of Freshwater Ecology, Ambleside (United Kingdom)

    1998-12-31

    Water chemistry data are reported for five high-altitude standing waters in the English Lake District, with current average pH values in the range 5-7. The waters show long-term increases in pH, ranging from 0.3 to 0.8 pH units, between 1974 and 1997. For the two intensively monitored sites (Devoke Water and Levers Waters), significant decreases in the concentration of non-marine sulphate are demonstrated; these have taken place concurrently with decreases in the atmospheric deposition of pollutant sulphur.

  11. Use of CuNi/YSZ and CuNi/SDC Catalysts for the Reverse Water Gas Shift Reaction

    OpenAIRE

    Maxime Lortie; Isaifan, Rima J.

    2015-01-01

    Cu50Ni50 nanoparticles were synthesized using a modified polyol method and deposited on samarium-doped ceria, SDC, and yttria-stabilized zirconia, YSZ, supports to form reverse water-gas shift, RWGS, catalysts. The best CO yields, obtained with the Cu50Ni50/SDC catalyst, were about 90% of the equilibrium CO yields. In contrast CO yields using Pt/SDC catalysts were equal to equilibrium CO yields at 700°C. Catalyst selectivity to CO was 100% at hydrogen partial pressures equal to CO2 partial...

  12. Characterisation of proton conducting oxide materials for use in reverse water gas shift catalysis and solid oxide fuel cells

    OpenAIRE

    De A. L. Viana, Hermenegildo

    2007-01-01

    This study concerned the preparation, characterisation and evaluation of different proton conductors for the Reverse Water Gas Shift Reaction (RWGS) and their evaluation as electrolytes for Solid Oxide Fuel Cells (SOFC) under H₂ and O₂. Materials with both catalytic and conductive properties are of a great interest, as their use in electrocatalytical systems may be very important. Sr₃CaZr₀.₅Ta₁.₅O₈.₇₅ (SCZT), BaCe₀.₉Y₀.₁O₂.₉₅ (BCY10) and Ba₃Ca₁.₁₈Nb₁.₈₂O₈.₇₃ (BCN18), were the initial material...

  13. A floating cogeneration system using the Russian KLT-40 reactor and Canadian reverse osmosis water purification technology

    International Nuclear Information System (INIS)

    As the global consumption of water increases with growing populations and rising levels of industrialization, major new sources of potable water production must be developed. To address this issue efficiently and economically, a new approach has been developed in Canada for the integration of reverse osmosis (RO) desalination systems with nuclear reactors as an energy source. The use of waste heat from the electrical generation process to preheat the RO feedwater, advanced feedwater pre-treatment and sophisticated system design integration and optimization techniques have led to improved water production efficiency, lower water production costs and reduced environmental impacts. CANDESAL Inc., has studied the use of its approach to the application of RO technology in the Russian APWS-80 floating nuclear desalination plant. Case studies show that water production efficiently improvements up to about 16% can be achieved. The energy consumed for the CANDESAL optimized APWS-80 design configuration is 4.2 kW·h/m3 compared to the base APWS-80 design value of 4.9 kW·h/m3. Although only a preliminary study, these results suggest that significant improvements in the cost of water production can be achieved. The potential benefits warrant further detailed evaluation followed by a demonstration project. (author). 1 ref., 6 figs, 2 tabs

  14. Use of reverse micelles in membrane protein structural biology

    International Nuclear Information System (INIS)

    Membrane protein structural biology is a rapidly developing field with fundamental importance for elucidating key biological and biophysical processes including signal transduction, intercellular communication, and cellular transport. In addition to the intrinsic interest in this area of research, structural studies of membrane proteins have direct significance on the development of therapeutics that impact human health in diverse and important ways. In this article we demonstrate the potential of investigating the structure of membrane proteins using the reverse micelle forming surfactant dioctyl sulfosuccinate (AOT) in application to the prototypical model ion channel gramicidin A. Reverse micelles are surfactant based nanoparticles which have been employed to investigate fundamental physical properties of biomolecules. The results of this solution NMR based study indicate that the AOT reverse micelle system is capable of refolding and stabilizing relatively high concentrations of the native conformation of gramicidin A. Importantly, pulsed-field-gradient NMR diffusion and NOESY experiments reveal stable gramicidin A homodimer interactions that bridge reverse micelle particles. The spectroscopic benefit of reverse micelle-membrane protein solubilization is also explored, and significant enhancement over commonly used micelle based mimetic systems is demonstrated. These results establish the effectiveness of reverse micelle based studies of membrane proteins, and illustrate that membrane proteins solubilized by reverse micelles are compatible with high resolution solution NMR techniques

  15. Use of reverse micelles in membrane protein structural biology

    Energy Technology Data Exchange (ETDEWEB)

    Van Horn, Wade D. [Vanderbilt University School of Medicine, Department of Biochemistry and Center for Structural Biology (United States); Ogilvie, Mark E.; Flynn, Peter F. [University of Utah, Department of Chemistry (United States)], E-mail: peter.flynn@utah.edu

    2008-03-15

    Membrane protein structural biology is a rapidly developing field with fundamental importance for elucidating key biological and biophysical processes including signal transduction, intercellular communication, and cellular transport. In addition to the intrinsic interest in this area of research, structural studies of membrane proteins have direct significance on the development of therapeutics that impact human health in diverse and important ways. In this article we demonstrate the potential of investigating the structure of membrane proteins using the reverse micelle forming surfactant dioctyl sulfosuccinate (AOT) in application to the prototypical model ion channel gramicidin A. Reverse micelles are surfactant based nanoparticles which have been employed to investigate fundamental physical properties of biomolecules. The results of this solution NMR based study indicate that the AOT reverse micelle system is capable of refolding and stabilizing relatively high concentrations of the native conformation of gramicidin A. Importantly, pulsed-field-gradient NMR diffusion and NOESY experiments reveal stable gramicidin A homodimer interactions that bridge reverse micelle particles. The spectroscopic benefit of reverse micelle-membrane protein solubilization is also explored, and significant enhancement over commonly used micelle based mimetic systems is demonstrated. These results establish the effectiveness of reverse micelle based studies of membrane proteins, and illustrate that membrane proteins solubilized by reverse micelles are compatible with high resolution solution NMR techniques.

  16. Efficiently Combining Water Reuse and Desalination through Forward Osmosis—Reverse Osmosis (FO-RO Hybrids: A Critical Review

    Directory of Open Access Journals (Sweden)

    Gaetan Blandin

    2016-07-01

    Full Text Available Forward osmosis (FO is a promising membrane technology to combine seawater desalination and water reuse. More specifically, in a FO-reverse osmosis (RO hybrid process, high quality water recovered from the wastewater stream is used to dilute seawater before RO treatment. As such, lower desalination energy needs and/or water augmentation can be obtained while delivering safe water for direct potable reuse thanks to the double dense membrane barrier protection. Typically, FO-RO hybrid can be a credible alternative to new desalination facilities or to implementation of stand-alone water reuse schemes. However, apart from the societal (public perception of water reuse for potable application and water management challenges (proximity of wastewater and desalination plants, FO-RO hybrid has to overcome technical limitation such as low FO permeation flux to become economically attractive. Recent developments (i.e., improved FO membranes, use of pressure assisted osmosis, PAO demonstrated significant improvement in water flux. However, flux improvement is associated with drawbacks, such as increased fouling behaviour, lower rejection of trace organic compounds (TrOCs in PAO operation, and limitation in FO membrane mechanical resistance, which need to be better considered. To support successful implementation of FO-RO hybrid in the industry, further work is required regarding up-scaling to apprehend full-scale challenges in term of mass transfer limitation, pressure drop, fouling and cleaning strategies on a module scale. In addition, refined economics assessment is expected to integrate fouling and other maintenance costs/savings of the FO/PAO-RO hybrid systems, as well as cost savings from any treatment step avoided in the water recycling.

  17. Efficiently Combining Water Reuse and Desalination through Forward Osmosis-Reverse Osmosis (FO-RO) Hybrids: A Critical Review.

    Science.gov (United States)

    Blandin, Gaetan; Verliefde, Arne R D; Comas, Joaquim; Rodriguez-Roda, Ignasi; Le-Clech, Pierre

    2016-01-01

    Forward osmosis (FO) is a promising membrane technology to combine seawater desalination and water reuse. More specifically, in a FO-reverse osmosis (RO) hybrid process, high quality water recovered from the wastewater stream is used to dilute seawater before RO treatment. As such, lower desalination energy needs and/or water augmentation can be obtained while delivering safe water for direct potable reuse thanks to the double dense membrane barrier protection. Typically, FO-RO hybrid can be a credible alternative to new desalination facilities or to implementation of stand-alone water reuse schemes. However, apart from the societal (public perception of water reuse for potable application) and water management challenges (proximity of wastewater and desalination plants), FO-RO hybrid has to overcome technical limitation such as low FO permeation flux to become economically attractive. Recent developments (i.e., improved FO membranes, use of pressure assisted osmosis, PAO) demonstrated significant improvement in water flux. However, flux improvement is associated with drawbacks, such as increased fouling behaviour, lower rejection of trace organic compounds (TrOCs) in PAO operation, and limitation in FO membrane mechanical resistance, which need to be better considered. To support successful implementation of FO-RO hybrid in the industry, further work is required regarding up-scaling to apprehend full-scale challenges in term of mass transfer limitation, pressure drop, fouling and cleaning strategies on a module scale. In addition, refined economics assessment is expected to integrate fouling and other maintenance costs/savings of the FO/PAO-RO hybrid systems, as well as cost savings from any treatment step avoided in the water recycling. PMID:27376337

  18. Removal of pharmaceuticals and endocrine disrupting compounds in a water recycling process using reverse osmosis systems

    OpenAIRE

    Al-Rifai, Jawad H.; Khabbaz, Hadi; Schaefer, Andrea I.

    2011-01-01

    A detailed investigation was carried out to evaluate the occurrence, persistence and fate of a range of micropollutants at different processing points at a full-scale water recycling plant (WRP) in Queensland, Australia. The WRP, which combines an advanced water treatment plant (AWTP) with a wastewater treatment plant (WWTP), produces high quality recycled water for industrial users. The concentrations of 11 pharmaceuticals from various therapeutic categories and two endocrine disrupting chem...

  19. Removal of pharmaceuticals and endocrine disrupting compounds in water recycling process using reverse osmosis systems

    OpenAIRE

    Al-Rifai, Jawad H.; Khabbazb, Hadi; Schäfer, Andrea

    2011-01-01

    A detailed investigation was carried out to evaluate the occurrence, persistence and fate of a range of micropollutants at different processing points at a full-scale water recycling plant (WRP) in Queensland, Australia. The WRP, which combines an advanced water treatment plant (AWTP) with a wastewater treatment plant (WWTP), produces high quality recycled water for industrial users. The concentrations of 11 pharmaceuticals from various therapeutic categories and two endocrine dis...

  20. Study of removal of uranium from spiked water using reverse osmosis technique

    International Nuclear Information System (INIS)

    Water is necessary for the sustenance of life form and clean water is essential for healthy living. Due to rapid population growth and subsequent industrialisation and urbanisation, the demand for adequate supply of fresh, safe and clean drinking water is growing around the globe. Water resources all over the world are threatened not only by over exploitation and poor management of the natural environment but also by ecological degradation. This can also be attributed to the anthropogenic activities such as discharge of untreated waste, dumping of industrial effluent, leaching from the waste dump sites, run-offs from agricultural fields, etc. Element like uranium which is radioactive and chemically toxic makes the case worse. It is a natural element present in water since inception of the earth. The chemical toxicity of uranium is overriding the radiological one due to its low specific activity

  1. Factors affecting fluoride and natural organic matter (NOM) removal from natural waters in Tanzania by nanofiltration/reverse osmosis.

    Science.gov (United States)

    Shen, Junjie; Schäfer, Andrea I

    2015-09-15

    This study examined the feasibility of nanofiltration (NF) and reverse osmosis (RO) in treating challenging natural tropical waters containing high fluoride and natural organic matter (NOM). A total of 166 water samples were collected from 120 sources within northern Tanzania over a period of 16 months. Chemical analysis showed that 81% of the samples have fluoride levels exceeding the WHO drinking guideline of 1.5mg/L. The highest fluoride levels were detected in waters characterized by high ionic strength, high inorganic carbon and on some occasions high total organic carbon (TOC) concentrations. Bench-scale experiments with 22 representative waters (selected based on fluoride concentration, salinity, origin and in some instances organic matter) and 6 NF/RO membranes revealed that ionic strength and recovery affected fluoride retention and permeate flux. This is predominantly due to osmotic pressure and hence the variation of diffusion/convection contributes to fluoride transport. Different membranes had distinct fluoride removal capacities, showing different raw water concentration treatability limits regarding the WHO guideline compliance. BW30, BW30-LE and NF90 membranes had a feed concentration limit of 30-40 mg/L at 50% recovery. NOM retention was independent of water matrices but is governed predominantly by size exclusion. NOM was observed to have a positive impact on fluoride removal. Several mechanisms could contribute but further studies are required before a conclusion could be drawn. In summary, NF/RO membranes were proved to remove both fluoride and NOM reliably even from the most challenging Tanzanian waters, increasing the available drinking water sources. PMID:26005995

  2. Pilot-Scale Investigation of Forward/Reverse Osmosis Hybrid System for Seawater Desalination Using Impaired Water from Steel Industry

    Directory of Open Access Journals (Sweden)

    Hanaa M. Ali

    2016-01-01

    Full Text Available This paper was focused on the investigation of a forward osmosis- (FO- reverse osmosis (RO hybrid process to cotreat seawater and impaired water from steel industry. By using this hybrid process, seawater can be diluted before desalination, hence reducing the energy cost of desalination, and simultaneously contaminants present in the impaired water are prevented from migrating into the product water through the FO and RO membranes. The main objective of this work was to investigate on pilot-scale system the performance of the combined FO pretreatment and RO desalination hybrid system and specifically its effects on membrane fouling and overall solute rejection. Firstly, optimization of the pilot-scale FO process to obtain the most suitable and stable operating conditions for practical application was investigated. Secondly, pilot-scale RO process performance as a posttreatment to FO process was evaluated in terms of water flux and rejection. The results indicated that the salinity of seawater reduced from 35000 to 13000 mg/L after 3 hrs using FO system, while after 6 hrs it approached 10000 mg/L. Finally, FO/RO system was tested on continuous operation for 15 hrs and it was demonstrated that no pollutant was detected neither in draw solution nor in RO permeate after the end of operating time.

  3. Reverse micelles extraction of nattokinase: From model system to real system

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Nattokinase is a novel fibrinolytic enzyme, which is homologous to Subtilisin Carlsberg. In this paper, Subtilisin Carlsberg was taken as a model protein of nattokinase. Effects of pH, ionic strength, concentration of isopropanol on the extraction of Subtilisin Carlsberg with AOT/isooctane reverse micelles system were investigated. Further, the process of reverse micelles extraction of nattokinase from fermentation broth was studied. By taking the reverse micelles of AOT/isooctane as extractant to perform a full extraction cycle, it was found that about eighty percent of the total activity of nattokinase in the fermentation broth could be recovered and the purification factor was about 2.5. Homologous protein could be reasonably used as model protein of a target protein.

  4. Formation of reverse micelles in supercritical carbon dioxide and its thermodynamics

    Institute of Scientific and Technical Information of China (English)

    WEN Zhen; DANG Zhi; ZONG Minhua; ZHU Zhixin

    2007-01-01

    The solubilization behavior of methyl orange as a solvation probe in multiple systems composed of supercritical carbon dioxide,surfactants and co-solvents,is studied.It is coneluded that some surfactants,such as sodium bis-(2-ethylhexyl)sulfosuccinate(AOT)and isooctyl phenol polyethoxylate (TX-10),could form reverse micelles in supercritical carbon dioxide under the action of butanol.The formation of reverse micelles is a spontaneous process thermodynamically.Specifically for the nonionic surfactant TX-10,the formation of reverse micelles is dependent on the entropy increase in the system,while for the anionic surfactant AOT,the micellization is mainly dominated by the increase in enthalpy at higher temperatures,but by the increase in entropy at lower temperatures.

  5. Fluorescence resonance energy transfer in AOT/4-chlorophenol/m-xylene organogels

    Energy Technology Data Exchange (ETDEWEB)

    Dandapat, Manika; Mandal, Debabrata, E-mail: dmandal.chemistry@gmail.com

    2015-06-15

    Fluorescence Resonance Energy Transfer (FRET) between donor coumarins (C102 and C153) and acceptor Rhodamine 6G were studied in AOT/4-chlorophenol/m-xylene organogels. The gel comprises a three-dimensional network of fiber bundles trapping the m-xylene solvent. Each fiber is an aggregate of several strands, and each strand consists of a central columnar stack of the phenols, surrounded by AOT headgroups. Our acceptor is ionic so that it was concentrated near the polar center of the strand, while the neutral donors were likely distributed over a wider region. With C153 as donor, clear evidence of FRET (time-constant~100 ps) was found, which indicated that the donor and acceptor may reside in neighboring strands within the same fiber. However, with C102 as donor, FRET probably occurred over an ultrashort, sub-picosecond time-scale suggesting that the donor and acceptor in this case resided in close vicinity. Thus, C102 tends to localize near the polar centre of the strands, compared to the more hydrophobic C153, which prefers to occupy the relatively non-polar peripheral regions of the strands and fibers. - Highlights: • FRET between coumarin donors and Rhodamine 6G acceptor studied in AOT organogels. • With Coumarin 153 donor, a ~100 ps FRET component detected in both donor and acceptor fluorescence. • With Coumarin 102 donor, FRET component too short to be detected with a time-resolution of ~70 ps. • The FRET rates reveal crucial differences in donor–acceptor distances for the two coumarin donors.

  6. High-pressure cloud point data for the system glycerol + olive oil + n-butane + AOT

    OpenAIRE

    J. P. Bender; A. Junges; Franceschi, E.; F. C. Corazza; C. Dariva; J. Vladimir Oliveira; M. L. Corazza

    2008-01-01

    This work reports high-pressure cloud point data for the quaternary system glycerol + olive oil + n-butane + AOT surfactant. The static synthetic method, using a variable-volume view cell, was employed for obtaining the experimental data at pressures up to 27 MPa. The effects of glycerol/olive oil concentration and surfactant addition on the pressure transition values were evaluated in the temperature range from 303 K to 343 K. For the system investigated, vapor-liquid (VLE), liquid-liquid (L...

  7. A predictive model of reverse micelles solubilizing water for solvent extraction.

    Science.gov (United States)

    Bley, Michael; Siboulet, Bertrand; Karmakar, Anwesa; Zemb, Thomas; Dufrêche, Jean-François

    2016-10-01

    Herein, a minimal model for the common case of W/O solubilization of badly soluble compounds present in an excess phase by reverse micellar aggregates in chemical equilibrium with its single compounds is introduced. A simple model of such liquid-liquid extractions is crucial for obtaining predictive parameter for the modelling of nuclear waste management and hydrometallurgic recycling strategies. The standard Gibbs free energy of aggregation and the concentration of the corresponding aggregate is calculated within a multiple-equilibria approach for a set of aggregate compositions of solute and amphiphilic extractant molecules. This minimal model provides potential surfaces estimating the stability of different aggregate compositions with 6.2kJmol(-1) as a generalized bending constant. The complete concentrations of free and aggregated extractant species as well as the favored aggregation numbers, the polydispersity, the activity of the organic solvent, and the critical concentrations are captured by this thermodynamic model. An increase of the apparent critical micelle concentration for an increasing solute content in the aqueous phase is detected by this method. PMID:27376975

  8. Lyophilization and Reconstitution of Reverse-Osmosis Concentrated Natural Organic Matter from a Drinking Water Source

    Science.gov (United States)

    Disinfection by-product (DBP) research can be complicated by difficulties in shipping large water quantities and changing natural organic matter (NOM) characteristics over time. To overcome these issues, it is advantageous to have a reliable method for concentrating NOM with min...

  9. Spatial and reversal learning in the Morris water maze are largely resistant to six hours of REM sleep deprivation following training

    OpenAIRE

    Walsh, Christine M.; Booth, Victoria; Poe, Gina R.

    2011-01-01

    This first test of the role of REM (rapid eye movement) sleep in reversal spatial learning is also the first attempt to replicate a much cited pair of papers reporting that REM sleep deprivation impairs the consolidation of initial spatial learning in the Morris water maze. We hypothesized that REM sleep deprivation following training would impair both hippocampus-dependent spatial learning and learning a new target location within a familiar environment: reversal learning. A 6-d protocol was...

  10. Microbial community analysis of fouled reverse osmosis membranes used in water recycling

    KAUST Repository

    Ayache, C.

    2013-06-01

    Biofouling on RO membranes has major cost implications in water reclamation. In this study membranes and water samples were collected from a RO pilot-plant operated on two sites to study the differences in microbial communities in order to develop a better understanding of the biofouling. For the two sites studied, the examination of the front membrane of the first stage and the tail membrane of the second stage of the RO train using 16S rRNA gene-based molecular technique showed that bacteria were similar on both stages and no significant effect of the membrane location within the RO train on the biofilm development could be discerned. However, the comparison of the identified bacteria from membrane samples between the two sites showed that each site is specific, leading to a different composition of microbial communities. The different nutrient concentrations in the RO feed water due to the different biological pre-treatments are one potential explanation for the observed differences in the microbial communities. Seasonal variations also play a major role in the development of microbial communities as shown by the significant differences observed between the communities measured in the samples in winter and summer on the second site. The results did not show similarity between the species identified on the RO membranes and in the feed water. Hence, the relationship of microbial community between the water generated during the pre-treatment process and RO membranes is not obvious. From this study, results showed that there is an actual need to investigate the development of microbial communities on membrane surface in real conditions in order to suggest tailored solutions for biofouling control and removal. © 2013 Elsevier Ltd.

  11. Reverse Osmosis, Ion Exchange and Other Processes for Point-of-Use (PostTreatment of Drinking Water – an Opinion from the Czech Republic

    Directory of Open Access Journals (Sweden)

    Janda Václav

    2009-12-01

    Full Text Available Utilization of apparatuses for point-of-use (e.g. chemical sorption, ion exchange and reverse osmosis is discussed. Simple rules for (potential consumers to use in selecting and maintaining the apparatuses are outlined. Such devices should be utilized very carefully, since although they can improve drinking water quality, they may deteriorate water quality for some other parameters. Moreover, drinking water quality from public drinking water networks is good and usually does not need to be improved. Therefore, utilization of an apparatus for drinking water quality improvement is suggested for individual water sources when specific contaminants of concern exist and should be removed.

  12. The Oxnard advanced water purification facility: combining indirect potable reuse with reverse osmosis concentrate beneficial use to ensure a California community's water sustainability and provide coastal wetlands restoration.

    Science.gov (United States)

    Lozier, Jim; Ortega, Ken

    2010-01-01

    The City of Oxnard in California is implementing a strategic water resources program known as the Groundwater Recovery Enhancement and Treatment (GREAT) program, which includes an Advanced Water Purification Facility (AWPF) that will use a major portion of the secondary effluent from the City's existing Water Pollution Control Facility to produce high-quality treated water to be used for irrigation of edible food crops, landscape irrigation, injection into the groundwater basin to form a barrier to seawater intrusion, and other industrial uses. The AWPF, currently under design by CH2M HILL, will employ a multiple-barrier treatment train consisting of microfiltration, reverse osmosis, and ultravioletlightbased advanced oxidation processes to purify the secondary effluent to conform to California Department of Public Health Title 22 Recycled Water Criteria for groundwater recharge. The AWPF, which will have initial and build-out capacities of ca. 24,000 and ca 95,000 m(3)/day, respectively, was limited to a 1.8-hectare site, with 0.4 hectares dedicated to a Visitor's Center and administration building. Further, the depth below grade and height of the AWPF's structures were constrained because of the high groundwater table at the site, the high cost of excavation and dewatering, and local codes. To accommodate these various restrictions, an innovative design approach has been developed. This paper summarizes the design constraints and innovative solutions for the design of the AWPF. PMID:20220237

  13. Nitrile group as infrared probe for the characterization of the conformation of bovine serum albumin solubilized in reverse micelles

    Science.gov (United States)

    Xue, Luyan; Zou, Feixue; Zhao, Yin; Huang, Xirong; Qu, Yinbo

    2012-11-01

    Infrared spectroscopy is a powerful technique for structure characterization. For a protein hosted in a reversed micellar medium, the spectral features of the protein are always interfered by the IR absorption bands of the medium in addition to the congestion in their IR spectra. Fortunately, there is a transparent window in the 2500-2200 cm-1 region. Incorporation of a vibrational probe with IR absorption frequencies in this region into proteins represents a promising strategy for the study of the conformation of a protein in a reverse micelle. In the present work, we incorporated 4-cyanobenzyl group (CN) into bovine serum albumin (BSA) via cysteine alkylation reactions under mild conditions. Circular dichroism spectroscopy showed that the Ctbnd N modified BSA (CNBSA) could retain its conformation. When CNBSA was hosted in AOT reverse micelle, it was found that the nitrile group on BSA was sensitive to the conformational change of BSA induced by urea as an additive in the reverse micelle. The peak splitting of nitrile group was also observed when the size of AOT reverse micelle and the concentration of an electrolyte were varied. Obviously, the shift of the IR absorption peak and/or peak splitting of nitrile group on BSA are correlated with the change of BSA conformation in AOT reverse micelle. So we conclude that the nitrile infrared probe can be used to study protein conformation in a reverse micelle.

  14. Assessment of nanofiltration and reverse osmosis potentialities to recover metals, sulfuric acid, and recycled water from acid gold mining effluent.

    Science.gov (United States)

    Ricci, Bárbara C; Ferreira, Carolina D; Marques, Larissa S; Martins, Sofia S; Amaral, Míriam C S

    2016-01-01

    This work assessed the potential of nanofiltration (NF) and reverse osmosis (RO) to treat acid streams contaminated with metals, such as effluent from the pressure oxidation process (POX) used in refractory gold ore processing. NF and RO were evaluated in terms of rejections of sulfuric acid and metals. Regarding NF, high sulfuric acid permeation (∼100%), was observed, while metals were retained with high efficiencies (∼90%), whereas RO led to high acid rejections (gold ore processing or commercialized. A metal-enriched stream could be also recovered in NF retentate and transferred to a subsequent metal recovery stage. In addition, considering the high acid rejection obtained through the proposed system, RO permeate could be used as recycling water. PMID:27438241

  15. Ambiphilic Frustrated Lewis Pair Exhibiting High Robustness and Reversible Water Activation: Towards the Metal-Free Hydrogenation of Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Étienne Rochette

    2015-06-01

    Full Text Available The synthesis and structural characterization of a phenylene-bridged Frustrated Lewis Pair (FLP having a 2,2,6,6‑tetramethylpiperidine (TMP as the Lewis base and a 9-borabicyclo[3.3.1]nonane (BBN as the Lewis acid is reported. This FLP exhibits unique robustness towards the products of carbon dioxide hydrogenation. The compound shows reversible splitting of water, formic acid and methanol while no reaction is observed in the presence of excess formaldehyde. The molecule is incredibly robust, showing little sign of degradation after heating at 80 °C in benzene with 10 equiv. of formic acid for 24 h. The robustness of the system could be exploited in the design of metal-free catalysts for the hydrogenation of carbon dioxide.

  16. Rapid detection of enteroviruses in small volumes of natural waters by real-time quantitative reverse transcriptase PCR.

    Science.gov (United States)

    Fuhrman, Jed A; Liang, Xiaolin; Noble, Rachel T

    2005-08-01

    Despite viral contamination of recreational waters, only bacterial, not viral, indicators are monitored routinely, due to a lack of rapid and cost-effective assays. We used negatively charged filters to capture enteroviruses from seawater and freshwater. Viral RNA was extracted using a commercial kit, and the viruses were quantified by real-time quantitative reverse transcriptase PCR (qRT-PCR). Poliovirus (6.6 to 330,000 virus particles/ml) was added to samples from watersheds in Los Angeles, California, and analysis showed that with 50-ml samples, a cellulose acetate/nitrate (HA) filter yielded final recovery of 51% (r2= 0.99) in fresh water and 23% (r2= 0.90) in seawater. However, for additions of low levels of virus (more likely to represent field samples; California: Topanga Creek (TC), a relatively pristine mountain creek, and Ballona Creek (BC), a concrete-lined urban storm drain. One TC site out of 10 and 2 BC sites out of 7 tested significantly positive for enteroviruses, with higher enterovirus concentrations in BC than in TC (ca. 10 to 25 versus 1 equivalent enterovirus particle/ml). The presented filtration-qRT-PCR approach is fast (contamination in environmental water samples. PMID:16085845

  17. Stronger sexual selection in warmer waters: the case of a sex role reversed pipefish.

    Directory of Open Access Journals (Sweden)

    Nuno M Monteiro

    Full Text Available In order to answer broader questions about sexual selection, one needs to measure selection on a wide array of phenotypic traits, simultaneously through space and time. Nevertheless, studies that simultaneously address temporal and spatial variation in reproduction are scarce. Here, we aimed to investigate the reproductive dynamics of a cold-water pipefish simultaneously through time (encompassing variation within each breeding cycle and as individuals grow and space (by contrasting populations experiencing distinct water temperature regimes in order to test hypothesized differences in sexual selection. Even though the sampled populations inhabited locations with very different water temperature regimes, they exhibited considerable similarities in reproductive parameters. The most striking was the existence of a well-defined substructure in reproductive activity, where larger individuals reproduce for longer periods, which seemed dependent on a high temperature threshold for breeding rather than on the low temperatures that vary heavily according to latitude. Furthermore, the perceived disparities among populations, such as size at first reproduction, female reproductive investment, or degree of sexual size dimorphism, seemed dependent on the interplay between seawater temperature and the operational sex ratio (OSR. Contrary to our expectations of an enhanced opportunity for sexual selection in the north, we found the opposite: higher female reproductive investment coupled with increased sexual size dimorphism in warmer waters, implying that a prolonged breeding season does not necessarily translate into reduced sexual selection pressure. In fact, if the limited sex has the ability to reproduce either continuously or recurrently during the entire breeding season, an increased opportunity for sexual selection might arise from the need to compete for available partners under strongly biased OSRs across protracted breeding seasons. A more general

  18. Fouling of reverse osmosis membranes by hydrocarbonated and fluorinated surfactants contained in firefighting water

    OpenAIRE

    Baudequin, Clement; Couallier, Estelle; Mai, Zhaohuan; Rakib, Mohammed; Deguerry, Isabelle; Severac, Romain; Pabon, Martial

    2012-01-01

    Large class B fires -- i.e. polar or non polar burning liquids -- can occur in places like refineries, airports or chemical plants. Such fires can be put out with the help of fire fighting foams prepared from specific aqueous formulations, called foam concentrates diluted in water to 1-6% and applied with a nozzle under the form of foam. Foam concentrates usually contain hydrocarbon surfactants or protein hydrolysates (synthetic or proteinic concentrate), and one or several fluorinated surfac...

  19. Risk assessments for forest trees: The performance of the ozone flux versus the AOT concepts

    Energy Technology Data Exchange (ETDEWEB)

    Karlsson, P.E. [Swedish Environmental Research Institute (IVL), PO Box 5302, S-400 14, Goeteborg (Sweden)]. E-mail: pererik.karlsson@ivl.se; Braun, S. [Institute for Applied Plant Biology, Schoenenbuch (Switzerland); Broadmeadow, M. [Environmental Research Branch, Forest Research Station, Alice Holt Lodge, Wrecclesham, Farnham, Surrey, GU10 4LH (United Kingdom); Elvira, S. [Ecotoxicidad de la Contaminacion Atmosferica, CIEMAT (ed 70), Avda. Complutense 22, 28040 Madrid (Spain); Emberson, L. [Stockholm Environment Institute at York, Box 373, University of York, York, YO10 5DD (United Kingdom); Gimeno, B.S. [Ecotoxicidad de la Contaminacion Atmosferica, CIEMAT (ed 70), Avda. Complutense 22, 28040 Madrid (Spain); Le Thiec, D. [I.N.R.A. Centre de Recherches Forestieres, UMR Ecologie et Ecophysiologie Forestieres Equipe Bioclimatologie, 54280 Champenoux (France); Novak, K. [WSL, Swiss Federal Research Institute, Zuercherstrasse 111, 8903 Birmensdorf (Switzerland); Oksanen, E. [Department of Biology, University of Joensuu, POB 111, 80101 Joensuu (Finland); Schaub, M. [WSL, Swiss Federal Research Institute, Zuercherstrasse 111, 8903 Birmensdorf (Switzerland); Uddling, J. [Department of Plant and Environmental Sciences, Goeteborg University, PO Box 461, SE-405 30 Goeteborg (Sweden); Wilkinson, M. [Environmental Research Branch, Forest Research Station, Alice Holt Lodge, Wrecclesham, Farnham, Surrey, GU10 4LH (United Kingdom)

    2007-04-15

    Published ozone exposure-response relationships from experimental studies with young trees performed at different sites across Europe were re-analysed in order to test the performance of ozone exposure indices based on AOTX (Accumulated exposure Over a Threshold of X nmol mol{sup -1}) and AF{sub st}Y (Accumulated Stomatal Flux above a threshold of Y nmol m{sup -2} s{sup -1}). AF{sub st}1.6 was superior, as compared to AOT40, for explaining biomass reductions, when ozone sensitive species with differing leaf morphology were included in the analysis, while this was not the case for less sensitive species. A re-analysis of data with young black cherry trees, subject to different irrigation regimes, indicated that leaf visible injuries were more strongly related to the estimated stomatal ozone uptake, as compared to the ozone concentration in the air. Experimental data with different clones of silver birch indicated that leaf thickness was also an important factor influencing the development of ozone induced leaf visible injury. - Ozone stomatal flux based indices were superior, as compared to AOT40, for explaining biomass reductions and leaf visible injury.

  20. Risk assessments for forest trees: The performance of the ozone flux versus the AOT concepts

    International Nuclear Information System (INIS)

    Published ozone exposure-response relationships from experimental studies with young trees performed at different sites across Europe were re-analysed in order to test the performance of ozone exposure indices based on AOTX (Accumulated exposure Over a Threshold of X nmol mol-1) and AFstY (Accumulated Stomatal Flux above a threshold of Y nmol m-2 s-1). AFst1.6 was superior, as compared to AOT40, for explaining biomass reductions, when ozone sensitive species with differing leaf morphology were included in the analysis, while this was not the case for less sensitive species. A re-analysis of data with young black cherry trees, subject to different irrigation regimes, indicated that leaf visible injuries were more strongly related to the estimated stomatal ozone uptake, as compared to the ozone concentration in the air. Experimental data with different clones of silver birch indicated that leaf thickness was also an important factor influencing the development of ozone induced leaf visible injury. - Ozone stomatal flux based indices were superior, as compared to AOT40, for explaining biomass reductions and leaf visible injury

  1. Ambient ozone phytotoxic potential over the Czech forests as assessed by AOT40

    Directory of Open Access Journals (Sweden)

    Hunova I

    2012-06-01

    Full Text Available Ambient ozone (O3 represents one of the most prominent air pollution pro­blems in Europe. We present an analysis on O3 with respect to its phytotoxic potential over Czech forests between 1994 and 2008. The phytotoxic potential is estimated based on the exposure index AOT40 for forests calculated from real-time monitoring data at 24 rural sites. Our results indicate high phytotoxic potential for most of the Czech Republic (CR with considerable inter-annual and spatial variability. The highest AOT40 values were 38-39 ppm·h. The cri­tical level for forest protection (5 ppm·h was usually exceeded early in the growing season, generally in May. In years with meteorological conditions conducive to ozone formation, the critical level was exceeded by 5-7 folds as compared to years with non-conducive conditions; nevertheless, all sites consi­stently exceeded the critical level since 1994. In the extremely hot and dry year 2003, the critical level for forests was exceeded over 31 % of the Czech forested area. More research is needed to translate these exceedances into forest injury in the CR.

  2. 反渗透系统浓水回收利用方案介绍%Introduction of Concentrated Water Recycling Scheme in Reverse Osmosis System

    Institute of Scientific and Technical Information of China (English)

    韩华全

    2012-01-01

    The application of reverse osmosis system in painting industry and several condense water treatment of reverse osmosis system technology which used broadly in home and abroad were briefly introduced. The recycling using situation of the condense water in reverse osmosis system was introduced, the status was analyzed and the recycling using of the condense water was proposed too.%简要介绍反渗透技术在涂装行业的应用及国内外目前使用较多的几种反渗透系统浓水处置方法,说明当前反渗透系统浓水回收利用情况,分析并提出浓水回收利用方案。

  3. Reverse-current circulation in connection-piping for hot-water storage tanks - Film; Waermeverluste durch Gegenstromzirkulation (rohrinterne Zirkulation) in an Speichern angeschlossenen Rohrleitungen

    Energy Technology Data Exchange (ETDEWEB)

    Vogelsanger, P.; Geisshuesler, S.; Lauber, A.; Daguenet, X.; Marty, H.

    2008-06-15

    This video film of 6.5 minutes duration shows on an impressive way the reverse-current circulation that takes place by natural convection in the connection-piping of a hot-water storage tank when no water is drawn off from the tank or circulated in the piping by means of a pump. The reverse-current circulation causes large heat losses and should be inhibited by means of heat traps or convection breaks. The laboratory experiments were performed using transparent piping. A blue dye was injected into the piping to visualise the water flow in its interior. The film also includes an excerpt of an older film from earlier research, in which the evidence of reverse-current circulation was first demonstrated in Switzerland.

  4. Modeling and optimization of hybrid wind–solar-powered reverse osmosis water desalination system in Saudi Arabia

    International Nuclear Information System (INIS)

    Highlights: • A hybrid wind/solar powered 1 kW reverse osmosis desalination system was modeled. • The system performance was simulated under Dhahran, Saudi Arabia, weather conditions. • The optimum system consists of 6 wind turbines, 66 PVs modules and 16 batteries. • The corresponding minimum cost of electric energy is 0.672 $/kW h. • Desalination costs $3.693–$3. 812/m3 depending on the raw water salinity. - Abstract: A hybrid wind/solar powered reverse osmosis desalination system has been modeled and simulated. The results of the simulation have been used to optimize the system for the minimum cost per cubic meter of the desalinated water. The performance of the hybrid wind/solar powered RO system has been analyzed under Dhahran, Saudi Arabia, weather data for a typical year. The performance has been evaluated under a constant RO load of 1 kW for 12 h/day and 24 h/day. The simulation results revealed that the optimum system that powers a 1-kW RO system for 12 h/day that yields a minimum levelized cost of energy comprises 2 wind turbines, 40 PVs modules and 6 batteries and the levelized cost of energy of such system is found to be 0.624 $/kW h. On the other hand, for a load of 1-kW for 24 h/day, the optimum system consists of 6 wind turbines, 66 PVs modules and 16 batteries with a minimum levelized cost of energy 0.672 $/kW h. Depending on the salinity of the raw water, the energy consumption for desalination ranges between 8 and 20 kW h/m3. This means that the cost of using the proposed optimum hybrid wind/solar system for water desalination will range between $3.693/m3 and $3. 812/m3 which is less than the range reported in the literature

  5. Simultaneous Hydrogen Sulphide and Carbon Dioxide Removal from Biogas by Water-Swollen Reverse Osmosis Membrane

    Czech Academy of Sciences Publication Activity Database

    Dolejš, Petr; Poštulka, Václav; Sedláková, Zuzana; Jandová, Věra; Vejražka, Jiří; Esposito, E.; Jansen, J.C.; Izák, Pavel

    2014-01-01

    Roč. 131, JUN 27 (2014), s. 108-116. ISSN 1383-5866 R&D Projects: GA ČR GAP106/10/1194; GA ČR GA14-12695S; GA TA ČR TE01020080; GA MŠk LH14006; GA MŠk(CZ) 7C11009; GA MŠk(CZ) LD13018 Grant ostatní: RFCS(XE) RFCRCT-2010-00009; PONRC(IT) PON01_01840 Institutional support: RVO:67985858 Keywords : agro-biogas upgrading * biomethane * water vapour Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 3.091, year: 2014

  6. Counterion exchange selectivity coefficients at water-in-oil microemulsion interface.

    Science.gov (United States)

    Gonçalves, Saulo A P; De Pauli, Silvia H; Tedesco, Antonio C; Quina, Frank H; Okano, Laura T; Bonilha, João B S

    2003-11-15

    The counterion binding at a water/Aerosol-OT (AOT)/heptane microemulsion interface was treated in the context of the pseudo-phase ion exchange formalism. Two approaches were used to determine the selectivity coefficient for copper/sodium counterion binding at the AOT microemulsion interface: measurements of the Cu(II) concentration taken up by the reverse micelle in a Winsor II microemulsion system and steady-state emission quenching measurements of an anionic water-solubilized probe, the tris-(4,4'-dicarboxy-2,2'-bipyridine) ruthenium (II) ion. In addition, the selectivity coefficient for methyl viologen/sodium at the microemulsion surface was determined by the same photophysical technique. The value for copper (II)/sodium exchange (K(Cu/Na)) is 1.1+/-0.3 and that for methyl viologen/sodium (K(MV/Na)) is 0.9+/-0.3. The results show that the pseudo-phase ion exchange model can be used to obtain the selectivity coefficient in a microemulsion system. PMID:14583227

  7. Use of perturbed angular correlation technique for studies of equilibrium systems: Cd-ions in water-pools of reversed micelles

    International Nuclear Information System (INIS)

    Possibilities and limitations of the perturbed angular correlation technique were investigated in a study of water-pools of reversed micelles of sodium-diethylhexylsulphosuccinate in iso-octane. Probe nuclide for the measurements was reactor produced 111mCd in the form of Cd2+-ions. The results indicate that Cd2+-ions are present inside the water-pool and predominantly experience the movements of the surrounding H2O molecules. An increase in the average number of Cd2+-ions per micelle seemed to have consequences for the size of the pools and, consequently, of the reversed micelles. (author)

  8. Thermal reversible gelation during phase separation of poly(N-isopropyl acrylamide)/water solution

    Institute of Scientific and Technical Information of China (English)

    曾钫[1; 刘新星[2; 童真[3; 杨燕银[4; 吴水珠[5

    2000-01-01

    By dynamic viscoelastic measurement for PNIPAM/water solution it has been found that below the phase separation temperature (about 32 ℃), the system is homogeneous fluid; while upon being heated to about 32 ℃, the solution undergoes phase separation and the storage modulus G’ increases sharply and exceeds the loss modulus G", indicating the physical network formation during the phase separation. Based on the percolation model, the gel points Tgel, were obtained by applying the dynamic scaling theory (DST) and winter’s criterion. The critical exponent n was also obtained to be 0.79 through DST, which is different from 0.67, the critical point of chemically crosslinked network predicted through DST. The obtained n value reflects the special property of physical network being different from chemical network.

  9. Evaluating the efficiency of different microfiltration and ultrafiltration membranes used as pretreatment for Red Sea water reverse osmosis desalination

    KAUST Repository

    Almashharawi, Samir

    2013-01-01

    Conventional processes are widely used as pretreatment for reverse osmosis (RO) desalination technology since its development. However, these processes require a large footprint and have some limitation issues such as difficulty to maintain a consistent silt density index, coagulation control at low total suspended solids, and management of higher waste sludge. Recently, there has been a rapid growth in the use of low-pressure membranes as pretreatment for RO systems replacing the conventional processes. However, despite the numerous advantages of using this integrated membrane system mainly providing good and stable water quality to RO membranes, many issues have to be addressed. The primary limitation is membrane fouling which reduces the permeate flux; therefore, higher pumping intensity is required to maintain a consistent volume of product. This paper aims to optimize the permeation flux and cleaning frequency by providing high permeate quality. Different low-pressure polyethersulfone membranes with different pore sizes ranging from 0.1 lm to 50 kDa were tested. Eight different filtration configurations have been applied including the variation of coagulant doses aiming to control membrane fouling. Results showed that all the configurations with/without coagulation, provided permeate with excellent water quality which improves the stability of RO performance. However, more stable fluxes with less-energy consumption were achieved by using the 0.1 lm and 100 kDa membranes with 1 mg/L FeCl3 coagulation. The use of UF membranes, having tight pores, without coagulation also proved to be an excellent option for Red Sea water RO pretreatment. © 2013 Desalination Publications.

  10. Comparison of Contrast Reduction based MODIS AOT estimates with AERONET measurements

    Science.gov (United States)

    Grosso, Nuno; Paronis, Dimitris

    2010-05-01

    Satellite remote sensing of aerosols offers global and seasonal coverage of aerosol distribution patterns resolving the spatial and temporal heterogeneities introduced by the existence of different sources and thus providing a more accurate and continuous quantification and characterization of the presence of aerosols in the atmosphere. Several retrieval methods have been implemented for various satellite sensors on an operational basis, providing global standard aerosol products such as Aerosol Optical Depth (AOD) and particle size related parameters. Current techniques such as dark pixel reflectance (MODIS, MERIS), multi-angle reflectance analysis (MISR, AATSR) or quantification of light polarisation by aerosols (POLDER) rely on known surface reflectance behaviours (e.g., low surface reflective bands or low sensitivity to polarised light) to separate the surface from the atmospheric signal by first modelling surface contribution. Their accuracy and has a limited application for highly reflective or heterogeneous surfaces such as urban, desert or snow covered areas. Another set of algorithms, the so-called Contrast Reduction based algorithms, might complement information given since their principle is based on the existence of a time invariant heterogeneous surface that allows AOT retrieval by measuring the contrast differences between a pair of images with similar viewing geometry. This paper presents the results of applying a contrast reduction based algorithm to a one year dateaset of MODIS images and comparing it to the AOT measurements of five European urban influenced AERONET stations (Barcelona, Cabo da Roca, Lille, Modena, Paris). Results demonstrate a high correlation (r=0.8, =0.05 and rmse=0.08) between the MODIS contrast reduction derived AOT results and the AERONET measurements, although a systematic overestimation is observed. The error analysis further shows sensitivity to observation geometry, time-lag between reference and polluted images

  11. Ultrafast IR Spectroscopy on Aqueous Reverse-Micellar Nano-Droplets

    NARCIS (Netherlands)

    Cringus, Dan; Milder, Maaike T.W.; Pshenichnikov, Maxim S.; Wiersma, Douwe A.; Lindner, Jörg; Vöhringer, Peter; Kobayashi, Takayoshi; Kobayashi, Tetsuro; Nelson, Keith A.; Okada, Tadashi; Silvestri, Sandro De

    2005-01-01

    The ultrafast dynamics of water nano-droplets (1-10 nm size) of the L2-phase of the ternary mixture H2O-AOT-CCl4 have been studied using frequency-resolved mid-infrared pump-probe spectroscopy in the spectral region of the OH-stretching vibration.

  12. Forward Osmosis/Low Pressure Reverse Osmosis for Water Reuse: Removal of Organic Micropollutants, Fouling and Cleaning

    KAUST Repository

    Linares, Rodrigo

    2011-07-01

    Forward osmosis (FO) is a natural process in which a solution with high concentration of solutes is diluted when being in contact, through a semipermeable membrane, with a low concentration solution. This osmotic process has been demonstrated to be efficient to recover wastewater effluents while diluting a saline draw solution. Nevertheless, the study of the removal of micropollutants by FO is barely described in the literature. This research focuses on the removal of these substances spiked in a secondary wastewater effluent, while diluting water from the Red Sea, generating feed water that can be desalinated with a low pressure reverse osmosis (LPRO) system. Another goal of this work is to characterize the fouling of the FO membrane, and its effect on micropollutants rejection, as well as the membrane cleaning efficiency of different methods. When considering only FO with a clean membrane, the rejection of the hydrophilic neutral compounds was between 48.6% and 84.7%, for the hydrophobic neutrals the rejection ranged from 40.0% to 87.5%, and for the ionic compounds the rejections were between 92.9% and 96.5%. With a fouled membrane, the rejections were between 44.6% to 95.2%, 48.7% to 91.5% and 96.9% to 98.6%, respectively. These results suggest that, except for the hydrophilic neutral compounds, the rejection of the micropollutants is increased by the fouling layer, possibly due to the higher hydrophilicity of the FO fouled membrane compared to the clean one, the increased adsorption capacity and reduced mass transport capacity, membrane swelling, and the higher negative charge of the surface, related to the foulants. However, when coupled with low pressure reverse osmosis, the rejections for both, the clean and fouled membrane, increased above 98%. The fouling layer, after characterizing the wastewater effluent and the concentrated wastewater after the FO process, proved to be composed of biopolymers, which can be removed with air scouring during short periods

  13. On the importance of steady-state isotopic techniques for the investigation of the mechanism of the reverse water-gas-shift reaction.

    Science.gov (United States)

    Tibiletti, Daniele; Goguet, Alexandre; Meunier, Frederic C; Breen, John P; Burch, Robbie

    2004-07-21

    The formation and reactivity of surface intermediates in the reverse water-gas-shift reaction on a Pt/CeO2 catalyst are critically dependent on the reaction conditions so that conclusions regarding the reaction mechanism cannot be inferred using ex operando conditions. PMID:15263955

  14. Spatial and Reversal Learning in the Morris Water Maze Are Largely Resistant to Six Hours of REM Sleep Deprivation Following Training

    Science.gov (United States)

    Walsh, Christine M.; Booth, Victoria; Poe, Gina R.

    2011-01-01

    This first test of the role of REM (rapid eye movement) sleep in reversal spatial learning is also the first attempt to replicate a much cited pair of papers reporting that REM sleep deprivation impairs the consolidation of initial spatial learning in the Morris water maze. We hypothesized that REM sleep deprivation following training would impair…

  15. High-pressure cloud point data for the system glycerol + olive oil + n-butane + AOT

    Directory of Open Access Journals (Sweden)

    J. P. Bender

    2008-09-01

    Full Text Available This work reports high-pressure cloud point data for the quaternary system glycerol + olive oil + n-butane + AOT surfactant. The static synthetic method, using a variable-volume view cell, was employed for obtaining the experimental data at pressures up to 27 MPa. The effects of glycerol/olive oil concentration and surfactant addition on the pressure transition values were evaluated in the temperature range from 303 K to 343 K. For the system investigated, vapor-liquid (VLE, liquid-liquid (LLE and vapor-liquid-liquid (VLLE equilibrium were recorded. It was experimentally observed that, at a given temperature and surfactant content, an increase in the concentration of glycerol/oil ratio led to a pronounced increase in the slope of the liquid-liquid coexistence curve. A comparison with results reported for the same system but using propane as solvent showed that much lower pressure transition values are obtained when using n-butane.

  16. Use of CuNi/YSZ and CuNi/SDC Catalysts for the Reverse Water Gas Shift Reaction

    Directory of Open Access Journals (Sweden)

    Maxime Lortie

    2015-01-01

    Full Text Available Cu50Ni50 nanoparticles were synthesized using a modified polyol method and deposited on samarium-doped ceria, SDC, and yttria-stabilized zirconia, YSZ, supports to form reverse water-gas shift, RWGS, catalysts. The best CO yields, obtained with the Cu50Ni50/SDC catalyst, were about 90% of the equilibrium CO yields. In contrast CO yields using Pt/SDC catalysts were equal to equilibrium CO yields at 700°C. Catalyst selectivity to CO was 100% at hydrogen partial pressures equal to CO2 partial pressures, 1 kPa, and decreased as methane was formed when the hydrogen partial pressure was 2 kPa or greater. The reaction results were explained using a combination of Eley-Rideal and Langmuir-Hinshelwood mechanisms that involved adsorption on the metal surface and the concentration of oxygen vacancies in the support. Finally the Cu50Ni50/SDC catalyst was found to be thermally stable for 48 hours at 600/700°C.

  17. Hot water tank: Sterilisation, reverse flow cooling and potential of calcification. Part 2. Computerized simulation; Trinkwassererwaermer: Entkeimung, Ruecklaufauskuehlung und Verkalkungspotential. T. 2. Numerische Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kunst, Bernhard [Fachhochschule Koeln (Germany)

    2010-06-15

    The good old hot water preparation has retired. Due to the legionnaires' disease, a sterilization reactor with a heating up of the drinking water resulted from this, at least within the hygienic sensitive range such as hospitals and old people's homes. Enhanced costs of energy additionally force for the application of long-distance heating, thermo technology and cogeneration units which all together require low hot water reverse flow temperatures. Thus, the sterilization should take place at moderate temperatures.

  18. A theoretical study of surface-structural sensitivity of the reverse water-gas shift reaction over Cu( hkl) surfaces

    Science.gov (United States)

    Wang, Gui-Chang; Jiang, Ling; Pang, Xian-Yong; Cai, Zun-Sheng; Pan, Yin-Ming; Zhao, Xue-Zhuang; Morikawa, Yoshitada; Nakamura, Junji

    2003-10-01

    The surface-structural sensitivity of the reverse water-gas shift (RWGS) reaction (CO 2 + H 2 → CO + H 2O) over the Cu(1 1 1), Cu(1 0 0), and Cu(1 1 0) surfaces has been studied by first-principle density functional calculations together with the UBI-QEP approach. Cluster models of the surface have been employed to simulate the adsorption of CO 2, H 2, H, O, OH, CO, and H 2O on the Cu( hkl) surfaces at low coverage. This sensitivity is determined by the difference in the activation barriers. It can be noticed that the most likely rate-determining step in RWGS reaction is the CO 2 dissociative adsorption, namely CO 2,g → CO s + O s. The trend in the calculated activation barriers for the reaction of CO 2 dissociative adsorption follows the order of Cu(1 1 0) reaction by copper is Cu(1 1 0), and the more densely packed Cu(1 1 1) surface is the least active among the Cu( hkl) surfaces studied here. As expected, the activation barriers for the recombinative reactions over Cu( hkl) are in the order of Cu(1 1 0) > Cu(1 0 0) > Cu(1 1 1), just opposite to the dissociative reactions. The interesting thing is that there is a good correlation between the adsorption bond length and the adsorption energy: The preferred adsorption site is the one with the shortest adsorption bond length. The present calculations are in good agreement with experimental observations.

  19. A Novelγ-Alumina Supported Fe-Mo Bimetallic Catalyst for Reverse Water Gas Shift Reaction

    Institute of Scientific and Technical Information of China (English)

    Abolfazl Gharibi Kharaji; Ahmad Shariati; Mohammad Ali Takassi

    2013-01-01

    In reverse water gas shift (RWGS) reaction CO2 is converted to CO which in turn can be used to pro-duce beneficial chemicals such as methanol. In the present study, Mo/Al2O3, Fe/Al2O3 and Fe-Mo/Al2O3 catalysts were synthesised using impregnation method. The structures of catalysts were studied using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) method, inductively coupled plasma atomic emission spectrometer (ICP-AES), temperature programmed reduction (H2-TPR), CO chemisorption, energy dispersive X-ray (EDX) and scanning electron microscopy (SEM) techniques. Kinetic properties of all catalysts were investigated in a batch re-actor for RWGS reaction. The results indicated that Mo existence in structure of Fe-Mo/Al2O3 catalyst enhances its activity as compared to Fe/Al2O3. This enhancement is probably due to better Fe dispersion and smaller particle size of Fe species. Stability test of Fe-Mo/Al2O3 catalyst was carried out in a fixed bed reactor and a high CO yield for 60 h of time on stream was demonstrated. Fe2(MoO4)3 phase was found in the structures of fresh and used catalysts. TPR results also indicate that Fe2(MoO4)3 phase has low reducibility, therefore the Fe2(MoO4)3 phase significantly inhibits the reduction of the remaining Fe oxides in the catalyst, resulted in high stability of Fe-Mo/Al2O3 catalyst. Overall, this study introduces Fe-Mo/Al2O3 as a novel catalyst with high CO yield, almost no by-products and fairly stable for RWGS reaction.

  20. Decrease of droplet size of the reverse microemulsion 1-butyl-3-methylimidazolium tetrafluoroborate/Triton X-100/cyclohexane by addition of water.

    Science.gov (United States)

    Gao, Yanan; Hilfert, Liane; Voigt, Andreas; Sundmacher, Kai

    2008-03-27

    In the present contribution, results concerning the role of small amounts of water in the 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4)-in-cyclohexane ionic liquid (IL) reverse microemulsions are reported. Dynamic light scattering (DLS) revealed that the size of microemulsion droplets decreased remarkably with increasing water content although water is often used as a polar component to swell reverse microemulsions. It was thus deduced that the number of microemulsion droplets was increased which was confirmed by conductivity measurements. The states of dissolved water were investigated by Fourier transform IR (FTIR) spectroscopic analysis showing that water molecules mainly act as bound water. 1H NMR along with two-dimensional rotating frame nuclear Overhauser effect (NOE) experiments (ROESY) further revealed that water molecules were mainly located in the periphery of the polar core of the microemulsion droplets and behave like a chock being inserted in the palisade layer of the droplet. This increased the curvature of the surfactant film at the IL/cyclohexane interface and thus led to the decrease of the microemulsion droplet size. The order of surfactant molecules arranged in the interface film was increased and thus induced a loss of entropy. Isothermal titration calorimetry (ITC) indicated that an enthalpy increase compensates for the loss of entropy during the process of microstructural transition. PMID:18318531

  1. Structure and dynamics of water in nonionic reverse micelles: a combined time-resolved infrared and small angle x-ray scattering study.

    Science.gov (United States)

    van der Loop, Tibert H; Panman, Matthijs R; Lotze, Stephan; Zhang, Jing; Vad, Thomas; Bakker, Huib J; Sager, Wiebke F C; Woutersen, Sander

    2012-07-28

    We study the structure and reorientation dynamics of nanometer-sized water droplets inside nonionic reverse micelles (water/Igepal-CO-520/cyclohexane) with time-resolved mid-infrared pump-probe spectroscopy and small angle x-ray scattering. In the time-resolved experiments, we probe the vibrational and orientational dynamics of the O-D bonds of dilute HDO:H(2)O mixtures in Igepal reverse micelles as a function of temperature and micelle size. We find that even small micelles contain a large fraction of water that reorients at the same rate as water in the bulk, which indicates that the polyethylene oxide chains of the surfactant do not penetrate into the water volume. We also observe that the confinement affects the reorientation dynamics of only the first hydration layer. From the temperature dependent surface-water dynamics, we estimate an activation enthalpy for reorientation of 45 ± 9 kJ mol(-1) (11 ± 2 kcal mol(-1)), which is close to the activation energy of the reorientation of water molecules in ice. PMID:22852627

  2. Structure and dynamics of water in nonionic reverse micelles: A combined time-resolved infrared and small angle x-ray scattering study

    Science.gov (United States)

    van der Loop, Tibert H.; Panman, Matthijs R.; Lotze, Stephan; Zhang, Jing; Vad, Thomas; Bakker, Huib J.; Sager, Wiebke F. C.; Woutersen, Sander

    2012-07-01

    We study the structure and reorientation dynamics of nanometer-sized water droplets inside nonionic reverse micelles (water/Igepal-CO-520/cyclohexane) with time-resolved mid-infrared pump-probe spectroscopy and small angle x-ray scattering. In the time-resolved experiments, we probe the vibrational and orientational dynamics of the O-D bonds of dilute HDO:H2O mixtures in Igepal reverse micelles as a function of temperature and micelle size. We find that even small micelles contain a large fraction of water that reorients at the same rate as water in the bulk, which indicates that the polyethylene oxide chains of the surfactant do not penetrate into the water volume. We also observe that the confinement affects the reorientation dynamics of only the first hydration layer. From the temperature dependent surface-water dynamics, we estimate an activation enthalpy for reorientation of 45 ± 9 kJ mol-1 (11 ± 2 kcal mol-1), which is close to the activation energy of the reorientation of water molecules in ice.

  3. A Pilot-scale Demonstration of Reverse Osmosis Unit for Treatment of Coal-bed Methane Co-produced Water and Its Modeling

    Institute of Scientific and Technical Information of China (English)

    钱智; 刘新春; 余志晟; 张洪勋; 琚宜文

    2012-01-01

    This study presents the first demonstration project in China for treatment of coal-bed methane(CBM) co-produced water and recycling.The work aims to provide a research and innovation base for solving the pollution problem of CBM extraction water.The reverse osmosis(RO) unit is applied to the treatment of CBM co-produced water.The results indicate that system operation is stable,the removal efficiency of the total dissolved solids(TDS) is as high as 97.98%,and Fe,Mn,and F-are almost completely removed.There is no suspended solids(SS) detected in the treated water.Furthermore,a model for the RO membrane separation process is developed to describe the quantitative relationship between key physical quantities-membrane length,flow velocity,salt concentration,driving pressure and water recovery rate,and the water recovery restriction equation based on mass balance is developed.This model provides a theoretical support for the RO system design and optimization.The TDS in the CBM co-produced water are removed to meet the "drinking water standards" and "groundwater quality standards" of China and can be used as drinking water,irrigation water,and livestock watering.In addition,the cost for treatment of CBM co-produced water is assessed,and the RO technology is an efficient and cost-effective treatment method to remove pollutants.

  4. Comparing concentration-based (AOT40) and stomatal uptake (PODY) metrics for ozone risk assessment to European forests.

    Science.gov (United States)

    Anav, Alessandro; De Marco, Alessandra; Proietti, Chiara; Alessandri, Andrea; Dell'Aquila, Alessandro; Cionni, Irene; Friedlingstein, Pierre; Khvorostyanov, Dmitry; Menut, Laurent; Paoletti, Elena; Sicard, Pierre; Sitch, Stephen; Vitale, Marcello

    2016-04-01

    Tropospheric ozone (O3 ) produces harmful effects to forests and crops, leading to a reduction of land carbon assimilation that, consequently, influences the land sink and the crop yield production. To assess the potential negative O3 impacts to vegetation, the European Union uses the Accumulated Ozone over Threshold of 40 ppb (AOT40). This index has been chosen for its simplicity and flexibility in handling different ecosystems as well as for its linear relationships with yield or biomass loss. However, AOT40 does not give any information on the physiological O3 uptake into the leaves since it does not include any environmental constraints to O3 uptake through stomata. Therefore, an index based on stomatal O3 uptake (i.e. PODY), which describes the amount of O3 entering into the leaves, would be more appropriate. Specifically, the PODY metric considers the effects of multiple climatic factors, vegetation characteristics and local and phenological inputs rather than the only atmospheric O3 concentration. For this reason, the use of PODY in the O3 risk assessment for vegetation is becoming recommended. We compare different potential O3 risk assessments based on two methodologies (i.e. AOT40 and stomatal O3 uptake) using a framework of mesoscale models that produces hourly meteorological and O3 data at high spatial resolution (12 km) over Europe for the time period 2000-2005. Results indicate a remarkable spatial and temporal inconsistency between the two indices, suggesting that a new definition of European legislative standard is needed in the near future. Besides, our risk assessment based on AOT40 shows a good consistency compared to both in-situ data and other model-based datasets. Conversely, risk assessment based on stomatal O3 uptake shows different spatial patterns compared to other model-based datasets. This strong inconsistency can be likely related to a different vegetation cover and its associated parameterizations. PMID:26492093

  5. Detection and Quantification of Infectious Avian Influenza A (H5N1) Virus in Environmental Water by Using Real-Time Reverse Transcription-PCR ▿

    OpenAIRE

    Dovas, C. I.; Papanastassopoulou, M.; Georgiadis, M. P.; Chatzinasiou, E.; Maliogka, V. I.; Georgiades, G. K.

    2010-01-01

    Routes of avian influenza virus (AIV) dispersal among aquatic birds involve direct (bird-to-bird) and indirect (waterborne) transmission. The environmental persistence of H5N1 virus in natural water reservoirs can be assessed by isolation of virus in embryonated chicken eggs. Here we describe development and evaluation of a real-time quantitative reverse transcription (RT)-PCR (qRT-PCR) method for detection of H5N1 AIV in environmental water. This method is based on adsorption of virus partic...

  6. Sizing of reverse micelles in microemulsions using NMR measurements of diffusion.

    Science.gov (United States)

    Law, Susan J; Britton, Melanie M

    2012-08-14

    This paper reports the size of reverse micelles (RMs) in AOT/octane/H(2)O and CTAB/hexanol/H(2)O microemulsions using magnetic resonance (MR) pulsed field gradient (PFG) measurements of diffusion. Diffusion data were measured using the pulsed gradient stimulated echo (PGSTE) experiment for surfactant molecules residing in the RM interface. Inverse Laplace transformation of these data generated diffusion coefficients for the RMs, which were converted into hydrodynamic radii using the Stokes-Einstein relation. This technique is complementary to those previously used to size RMs, such as dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS), but also offers several advantages, which are discussed. RM sizes, determined using the PGSTE method, in the AOT (sodium bis(2-ethylhexyl) sulfosuccinate) and CTAB (cetyltrimethylammonium bromide) microemulsions were compared with previous DLS and SAXS data, showing good agreement. Methods for determining number distributions from the PGSTE data, through the use of scaling factors, were investigated. PMID:22794150

  7. Multi-isotope (B, Li, O, H) tracing of reverse osmosis treated waste water recharged artificially into a coastal aquifer (Torreele/Wulpen, Belgium)

    International Nuclear Information System (INIS)

    Artificially enhanced aquifer recharge is gaining importance in the active management of groundwater resources, in particular in coastal areas endangered by marine intrusion. Within the FP6 project Reclaim Water, the site of Torreele/Wulpen, at the Belgium North Sea Coast, was investigated, where secondary treated municipal wastewater is further purified through ultrafiltration and reverse osmosis (RO) before being infiltrated into the coastal dunes in order to reduce the extraction of natural groundwater for potable water production and hold back saline intrusion. B and Li isotopes as well as stable isotopes of oxygen and hydrogen were analysed to evaluate the extension of the injected water in the aquifer body. The infiltration and mixing of RO-treated wastewater with natural groundwaters could be intimately monitored. B isotopes performed particularly well due to a characteristic waste water signature and high contrasts of natural end-members (total range > 25 per mille vs. NBS951) (author)

  8. Bioluminescence-Based Method for Measuring Assimilable Organic Carbon in Pretreatment Water for Reverse Osmosis Membrane Desalination ▿

    OpenAIRE

    Weinrich, Lauren A.; Schneider, Orren D.; LeChevallier, Mark W.

    2010-01-01

    A bioluminescence-based assimilable organic carbon (AOC) test was developed for determining the biological growth potential of seawater within the reverse osmosis desalination pretreatment process. The test uses Vibrio harveyi, a marine organism that exhibits constitutive luminescence and is nutritionally robust. AOC was measured in both a pilot plant and a full-scale desalination plant pretreatment.

  9. Main coolant pump resistance influence on single phase water reverse flow in the inverted U-tubes under natural circulation

    International Nuclear Information System (INIS)

    Based on nuclear power plant (NPP) best-estimate transient analysis with RELAP5/MOD3 code, the reactor point kinetics model in RELAP5/MOD3 code is replaced by the two-group, 3-D space and time dependent neutron kinetic model, and two-fluid model is replaced by drift flux model. A coupled three-dimensional physics and thermal-hydrodynamics model is used to develop its corresponding computing code, thus simulating natural circulation of single-phase flow for the PWR. In this paper, we report the forward and reverse flow distribution in the inverted U-tubes of the steam generator (SG) under some typical operating conditions in the natural circulation case, and analyze the influence of main coolant pump resistance on the forward and reverse flow distribution. The calculation results show that, the pressure drop between SG inlet and outlet plenum decreases, and the SG inlet and outlet mass flow decrease with an increased main coolant pump resistance, but net mass flux of reverse flow in inverted U-tubes, and the ratio of mass flow in all reverse flow tubes to that of main coolant pipeline increase, meanwhile, the secondary steam load is invariable in this process. (authors)

  10. Reversible Thermoassociation of Water-Soluble Polymers Thermoassociation réversible de polymères hydrosolubles

    Directory of Open Access Journals (Sweden)

    L'alloret F.

    2006-12-01

    Full Text Available In various industrial fields, water soluble polymers are commonly used as thickening agents to control the reology of aqueous fluids. Nevertheless, their properties are weakened as the temperature increases. In order to overcome this problem, the concept of thermoassociativewater soluble polymers was developed. Such new amphilic systems can be obtained by grafting on an hydrophilic backbone, side chains which become non water soluble above a Lower Critical Solution Temperature (LCST. Semidilute solutions of these copolymers present reversible thickening properties as the temperature increases and reaches a critical value, close to the side chains LCST. This behaviour can be related to the agregation of the grafts above their LCST, into hydrophobic microdomains , inducing the formation of a three dimensional network. At higher temperature, the viscosity of the solution sheared at a constant rate reaches a maximum value. This can be interpreted in terms of the reorganisation of the physical network under shear, from a structure with mainly intermolecular associationsto a system with an increasing number of intramolecular associations . Owing to the diversity of water soluble polymers exhibiting a phase separation on heating (LCST, different thermoassociativecopolymers were realized [1] and [2], using either polyelectrolyte or neutral hydrophilic backbone. In the aim of applications of such systems in the oilfield industry, copolymers containing 2-acrylamido 2-methyl propane sulfonic acid (AMPS were developed, using polyethylene oxide (PEO as LCST grafts. A general description of their rheological behaviour will be given here. Their properties can be controlled either by varying the solution characteristic (polymer concentration, salinity, etc. or by modifying the chemical structure of the copolymer (grafting ratio, molecular weight of the backbone, etc. . This rheological study showed the potentiality of the thermoassociativesystem, particularly

  11. Hydrophobic ion pairing of a minocycline/Ca(2+)/AOT complex for preparation of drug-loaded PLGA nanoparticles with improved sustained release.

    Science.gov (United States)

    Holmkvist, Alexander Dontsios; Friberg, Annika; Nilsson, Ulf J; Schouenborg, Jens

    2016-02-29

    Polymeric nanoparticles is an established and efficient means to achieve controlled release of drugs. Incorporation of minocycline, an antibiotic with anti-inflammatory and neuroprotective properties, into biodegradable nanoparticles may therefore provide an efficient means to combat foreign body reactions to implanted electrodes in the brain. However, minocycline is commonly associated with poor encapsulation efficiencies and/or fast release rates due to its high solubility in water. Moreover, minocycline is unstable under conditions of low and high pH, heat and exposure to light, which exacerbate the challenges of encapsulation. In this work drug loaded PLGA nanoparticles were prepared by a modified emulsification-solvent-diffusion technique and characterized for size, drug encapsulation and in vitro drug release. A novel hydrophobic ion pair complex of minocycline, Ca(2+) ions and the anionic surfactant AOT was developed to protect minocycline from degradation and prolong its release. The optimized formulation resulted in particle sizes around 220 nm with an entrapment efficiency of 43% and showed drug release over 30 days in artificial cerebrospinal fluid. The present results constitute a substantial increase in release time compared to what has hitherto been achieved for minocycline and indicate that such particles might provide useful for sustained drug delivery in the CNS. PMID:26773599

  12. Reverse-current circulation in connection-piping for hot-water storage tanks - Report; Waermeverluste durch Gegenstromzirkulation (rohrinterne Zirkulation) in an Speichern angeschlossenen Rohrleitungen

    Energy Technology Data Exchange (ETDEWEB)

    Vogelsanger, P.; Geisshuesler, S.; Lauber, A.; Daguenet, X.; Marty, H.

    2008-06-15

    This article deals with a set of commented presentation slides and a video presentation issued by the Swiss Solar Testing Institute (SPF) at the University of Applied Sciences in Rapperswil, Switzerland, in co-operation with the Swiss Federal Office of Energy and the Swiss Association of Architects and Engineers (SIA). It takes a look at reverse current circulation in the connections to hot-water storage tanks. This circulation causes large heat losses and, therefore, should be inhibited. The methods and equipment used to demonstrate and visualise the reverse-current effect are discussed and described, including references to earlier research carried out at the Paul Scherrer Institute. So-called 'heat-traps' and 'convection brakes' that help inhibit such circulation are described and discussed. Also, relevant international standards are looked at and measurements made with various configurations are quoted. Recommendations on the dimensioning of installations are made and suggestions for further research are listed.

  13. Study on technologies of forward extraction of protein from tomato by reverse micelles%反胶束溶液萃取番茄凝集素的前萃工艺探讨

    Institute of Scientific and Technical Information of China (English)

    朱澄云; 王岩; 赵琨; 韩国华; 徐璐; 黄小丽

    2011-01-01

    Objective To explore the possibility of extraction of tomato lectin by aerosol OT (AOT)isooctane reverse micelles system. Methods The effects of pH, AOT concentration, KC1 concentration on the forward extraction rate were investigated and analyzed. Results At the condition of KC1 concentration 50 mmol·L-1 ,AOT concentration 110 mmol·L-1 and pH 9.0 ,the forward protein extraction rate achieved 46. 51%. Conclusions It is possible to extract tomato lectin using reversed micelles of AOT-isooctane.%目的 探讨用丁二酸二异辛酯磺酸钠(aerosl OT,AOT)-异辛烷反胶束体系萃取番茄凝集素的可能性.方法 考察并分析了反胶束溶液萃取番茄凝集素时的几种因素如pH值、表面活性剂AOT的浓度、KC1的浓度等对蛋白前萃率的影响.结果 在KC1浓度为50 mmol·L-1、AOT浓度为110 mmol·L-1及pH值9.0条件下前萃取率为46.51%.结论 以AOT-异辛烷反胶束溶液萃取番茄凝集素是可行的.

  14. Reverse Engineering

    International Nuclear Information System (INIS)

    This book gives descriptions of reverse engineering with principle and structure of it, including what reverse engineering is, prospect and concerned laws, basic knowledge for reverse engineering like manual and back to user mode, using tool such as IDA installation, dependency walker and dump bin, network monitoring and universal extractor. It indicates analysis of malignant code, giving explanations of file virus, spy ware, an infection way of malignant code, anti debugging like Find window.

  15. Description and validation of an AOT product over land at the 0.6 μm channel of the SEVIRI sensor onboard MSG

    Science.gov (United States)

    Bernard, E.; Moulin, C.; Ramon, D.; Jolivet, D.; Riedi, J.; Nicolas, J.-M.

    2011-11-01

    The Spinning Enhanced Visible and InfraRed Imager (SEVIRI) aboard Meteosat Second Generation (MSG) launched in 2003 by EUMETSAT is dedicated to the Nowcasting applications and Numerical Weather Prediction and to the provision of observations for climate monitoring and research. We use the data in visible and near infrared (NIR) channels to derive the aerosol optical thickness (AOT) over land. The algorithm is based on the assumption that the top of the atmosphere (TOA) reflectance increases with the aerosol load. This is a reasonable assumption except in case of absorbing aerosols above bright surfaces. We assume that the minimum in a 14-days time series of the TOA reflectance is, once corrected from gaseous scattering and absorption, representative of the surface reflectance. The AOT and the aerosol model (a set of 5 models is used), are retrieved by matching the simulated TOA reflectance with the TOA reflectances measured by SEVIRI in its visible and NIR spectral bands. The high temporal resolution of the data acquisition by SEVIRI allows to retrieve the AOT every 15 min with a spatial resolution of 3 km at sub-satellite point, over the entire SEVIRI disk covering Europe, Africa and part of South America. The resulting AOT, a level 2 product at the native temporal and spatial SEVIRI resolutions, is presented and evaluated in this paper. The AOT has been validated using ground based measurements from AErosol RObotic NETwork (AERONET), a sun-photometer network, focusing over Europe for 3 months in 2006. The SEVIRI estimates correlate well with the AERONET measurements, r = 0.64, with a slight overestimate, bias = -0.017. The sources of errors are mainly the cloud contamination and the bad estimation of the surface reflectance. The temporal evolutions exhibited by both datasets show very good agreement which allows to conclude that the AOT Level 2 product from SEVIRI can be used to quantify the aerosol content and to monitor its daily evolution with a high temporal

  16. Development and evaluation of a culture-independent method for source determination of fecal wastes in surface and storm waters using reverse transcriptase-PCR detection of FRNA coliphage genogroup gene sequences.

    Science.gov (United States)

    A complete method, incorporating recently improved reverse transcriptase-PCR primer/probe assays and including controls for determining interferences to phage recoveries from water sample concentrates and for detecting interferences to their analysis, was developed for the direct...

  17. Analysis and modeling of PEM fuel cell stack performance: Effect of in situ reverse water gas shift reaction and oxygen bleeding

    Science.gov (United States)

    Karimi, G.; Li, Xianguo

    In this study the performance of a polymer electrolyte membrane (PEM) fuel cell stack is analyzed with a mathematical model when the stack operates on hydrocarbon reformate gas as the anode feed stream. It is shown that the effect of carbon dioxide dilution of the hydrogen dominated reformate gas has a minimal impact on the stack performance. However, the CO-poisoning effect due to the in situ reverse water gas shift reaction in the anode feed stream could have a very serious adverse impact on the stack performance, especially at high current densities. Thermodynamic calculations indicate that the equilibrium concentrations of CO could be as high as 100 ppm, generated by the in situ reverse water gas shift reaction, under the typical conditions of PEM fuel cell operation; and are influenced by the stack operating temperature and water content of the reformate anode feed. This CO-poisoning of the stack performance is shown mitigated effectively by introducing about 0.5-1% oxygen to the anode feed.

  18. The synthesis of methanol and the reverse water-gas shift reaction over Zn-deposited Cu(100) and Cu(110) surfaces: comparison with Zn/Cu(111)

    Science.gov (United States)

    Nakamura, I.; Fujitani, T.; Uchijima, T.; Nakamura, J.

    1998-03-01

    The catalytic activity of Zn vapor-deposited Cu(100) and Cu(110) surfaces for methanol synthesis by the hydrogenation of CO 2 and the reverse water-gas shift reaction were studied using an XPS apparatus combined with a high-pressure flow reactor (18 atm). At a reaction temperature of 523 K, no promotional effect of Zn was observed for the methanol synthesis on both Zn/Cu(100) and Zn/Cu(110). The results were quite different from those for Zn/Cu(111), on which a significant promotion of methanol synthesis activity appeared to be due to the deposition of Zn, indicating that the promotional effect of Zn was sensitive to the surface structure of Cu. However, hysteresis was observed in the catalytic activity for methanol synthesis over the Zn/Cu(110) surface upon heating above 543 K in the reaction mixture. The activity became twice that measured before heating, which was close to the methanol synthesis activity of Zn/Cu(111) at the same Zn coverage. On the other hand, no such hysteresis was observed for the reverse water-gas shift reaction on Zn/Cu(110), indicating that the active site for methanol synthesis was not identical to that for the reverse water-gas shift reaction. In the post-reaction surface analysis, formate species was detected on both Zn/Cu(100) and Zn/Cu(110), whose coverage increased with increasing Zn coverage at 0< ΘZn<0.2. No correlation between the formate coverage and the methanol synthesis activity was obtained, which was in contrast to the results for Zn/Cu(111). Thus, the structure sensitivity observed in the catalytic activity of methanol synthesis over Zn-deposited Cu surfaces is ascribed to the significant difference in the reactivity of the formate intermediate.

  19. Synthesis of CuNi/C and CuNi/γ-Al2O3 Catalysts for the Reverse Water Gas Shift Reaction

    OpenAIRE

    Maxime Lortie; Rima Isaifan; Yun Liu; Sander Mommers

    2015-01-01

    A new polyol synthesis method is described in which CuNi nanoparticles of different Cu/Ni atomic ratios were supported on both carbon and gamma-alumina and compared with Pt catalysts using the reverse water gas shift, RWGS, reaction. All catalysts were highly selective for CO formation. The concentration of CH4 was less than the detection limit. Cu was the most abundant metal on the CuNi alloy surfaces, as determined by X-ray photoelectron spectroscopy, XPS, measurements. Only one CuNi al...

  20. Effects of water ageing on the mechanical properties of flax and glass fibre composites: Degradation and reversibility

    OpenAIRE

    Apolinario, Guilherme; Ienny, Patrick; Corn, Stéphane; Léger, Romain; Bergeret, Anne; Haudin, Jean-Marc

    2015-01-01

    Mechanical properties of flax-fibre reinforced composites (FFRC) are strongly affected by water ageing compared to glass-fibre reinforced composites (GFRC). This study highlights the influence of water absorption during immersion at 30°C on mechanical properties of unsaturated polyester reinforced composites. Flax-fibre composites showed a Fickian absorption behaviour and a water uptake 15 times higher than that of glass-fibre composites. GFRC's tensile modulus and maximum stress were slightl...

  1. Role of solubilized water in the reverse ionic liquid microemulsion of 1-butyl-3-methylimidazolium tetrafluoroborate/TX-100/benzene.

    Science.gov (United States)

    Gao, Yan'an; Li, Na; Zheng, Liqiang; Bai, Xiangtao; Yu, Li; Zhao, Xueyan; Zhang, Jin; Zhao, Mingwei; Li, Zhen

    2007-03-15

    The ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) can form nonaqueous microemulsions with benzene by the aid of nonionic surfactant TX-100. The effect of water on ionic liquid-in-oil (IL/O) microemulsions was studied, and it was shown that the addition of small amount of water to the IL microemulsion contributed to the stability of microemulsion and thus increased the amount of solubilized bmimBF4 in the microemulsion. The conductivity measurements also showed that the attractive interactions between IL microdroplets were weakened, that is, the IL/O microemulsion becomes more stable in the present of some water. Fourier transform IR was carried out to analyze the states of the added water, and the result showed that these water molecules mainly behaved as bound water and trapped water, indicating that the water molecules are located in the palisade layers of the IL/O microemulsion. Furthermore, 1H NMR and 19F NMR spectra suggested that the added water molecules built the hydrogen binding network of imidazolium cations and H2O, BF4- anion and H2O, and at the same time the electronegative oxygen atoms of the oxyethylene units of TX-100 and water in the palisade layers, which made the palisade layers more firm and thus increased the stability of the microemulsion. The study can help in further understanding the formation mechanism of microemulsions. In addition, the characteristic solubilization behavior of the added water can provide an aqueous interface film for hydrolysis reactions and therefore may be used as an ideal medium to prepare porous or hollow nanomaterials. PMID:17305388

  2. Pilot study on arsenic removal from groundwater using a small-scale reverse osmosis system-Towards sustainable drinking water production.

    Science.gov (United States)

    Schmidt, Stefan-André; Gukelberger, Ephraim; Hermann, Mario; Fiedler, Florian; Großmann, Benjamin; Hoinkis, Jan; Ghosh, Ashok; Chatterjee, Debashis; Bundschuh, Jochen

    2016-11-15

    Arsenic contamination of groundwater is posing a serious challenge to drinking water supplies on a global scale. In India and Bangladesh, arsenic has caused the most serious public health issue in the world for nearly two decades. The aim of this work was to study an arsenic removal system based on reverse osmosis at pilot scale treating two different water sources from two different locations in the State of Bihar, India. For this purpose two villages, Bind Toli and Ramnagar in the Patna District were selected, both located very close to the river Ganga. The trials were conducted with aerated and non-aerated groundwater. It is the first time that the arsenic removal efficiency for aerated and non-aerated groundwater by reverse osmosis technology in combination with an energy-saving recovery system have been studied. As the principle of reverse osmosis requires a relatively high pressure, its energy demand is naturally high. By using an energy recovery system, this demand can be lowered, leading to an energy demand per liter permeate of 3-4Wh/L only. Due to high iron levels in the groundwater and as a consequence the precipitation of ferric (hydr)oxides, it was necessary to develop a granular media filter for the trials under aeration in order to protect the membrane from clogging. Two different materials, first locally available sand, and second commercially available anthracite were tested in the granular media filter. For the trials with aerated groundwater, total arsenic removal efficiency at both locations was around 99% and the arsenic concentration in permeate was in compliance with the WHO and National Indian Standard of 10μg/L. However, trials under anoxic conditions with non-aerated groundwater could not comply with this standard. Additionally a possible safe discharge of the reverse osmosis concentrate into an abandoned well was studied. It was observed that re-injection of reject water underground may offer a safe disposal option. However, long

  3. Interfacial hydrodynamic instabilities driven by cross-diffusion in reverse microemulsions

    Science.gov (United States)

    Budroni, M. A.; Carballido-Landeira, J.; Intiso, A.; De Wit, A.; Rossi, F.

    2015-06-01

    When two microemulsions are put in contact in the gravity field along a horizontal contact line, cross-diffusion can trigger the transport of one species in the presence of a gradient in concentration of another species. We show here theoretically that such cross-diffusion effects can induce buoyancy-driven convective instabilities at the interface between two solutions of different compositions even when initially the less dense solution lies on top of the denser one. Two different sources of convective modes are identified depending whether positive or negative cross-diffusion is involved. We evidence the two predicted cross-diffusion driven instabilities experimentally using a two-layer stratification of Aerosol-OT (AOT) water-in-oil microemulsions solutions with different water or AOT composition.

  4. Genome-wide association mapping combined with reverse genetics identifies new effectors of low water potential-induced proline accumulation in Arabidopsis.

    Science.gov (United States)

    Verslues, Paul E; Lasky, Jesse R; Juenger, Thomas E; Liu, Tzu-Wen; Kumar, M Nagaraj

    2014-01-01

    Arabidopsis (Arabidopsis thaliana) exhibits natural genetic variation in drought response, including varying levels of proline (Pro) accumulation under low water potential. As Pro accumulation is potentially important for stress tolerance and cellular redox control, we conducted a genome-wide association (GWAS) study of low water potential-induced Pro accumulation using a panel of natural accessions and publicly available single-nucleotide polymorphism (SNP) data sets. Candidate genomic regions were prioritized for subsequent study using metrics considering both the strength and spatial clustering of the association signal. These analyses found many candidate regions likely containing gene(s) influencing Pro accumulation. Reverse genetic analysis of several candidates identified new Pro effector genes, including thioredoxins and several genes encoding Universal Stress Protein A domain proteins. These new Pro effector genes further link Pro accumulation to cellular redox and energy status. Additional new Pro effector genes found include the mitochondrial protease LON1, ribosomal protein RPL24A, protein phosphatase 2A subunit A3, a MADS box protein, and a nucleoside triphosphate hydrolase. Several of these new Pro effector genes were from regions with multiple SNPs, each having moderate association with Pro accumulation. This pattern supports the use of summary approaches that incorporate clusters of SNP associations in addition to consideration of individual SNP probability values. Further GWAS-guided reverse genetics promises to find additional effectors of Pro accumulation. The combination of GWAS and reverse genetics to efficiently identify new effector genes may be especially applicable for traits difficult to analyze by other genetic screening methods. PMID:24218491

  5. The effect of operating parameters on ultrafiltration and reverse osmosis of palm oil mill effluent for reclamation and reuse of water

    Directory of Open Access Journals (Sweden)

    Nazatul Shima Azmi

    2013-02-01

    Full Text Available An attempt was made to reclaim and recover palm oil mill effluent (POME for water reuse using tubular ultrafiltration (UF and reverse osmosis (RO membranes. The reclaimed water was compared with the final discharged water of the local mill. The raw POME was first subjected to a physical pre-treatment process to remove the content of organic matter and suspended solids. The pre-treatment process was coupled with membrane technology (UF and RO to reclaim the clean water from POME. From the combined techniques of UF (5 bar and RO (30 bar the results showed that the turbidity and BOD5 were reduced by 99% and 98.9%, respectively. Compared to the final discharged POME, this suggested method gives a significant difference in BOD5 and turbidity. The final permeate of RO was found to comply with the standards for water reuse. Therefore, the combined UF and RO method is a viable alternative and has a great potential for use in the palm oil industry.

  6. Two 3D network complexes of Y(III) and Ce(III) with 2-fold interpenetration and reversible desorption-adsorption behavior of lattice water

    International Nuclear Information System (INIS)

    Two novel inorganic-organic 3D network, namely{[Ln(L)1.5(H2O)2].5H2O}n [Ln=Y (1), Ce (2)] [Ln(L)1.5(H2O)2].5H2O [Ln=Y (1), Ce (2)], have been prepared through the assembly of the ligand 1,2-bis[3-(1,2,4-triazolyl)-4-amino-5-carboxylmethylthio]ethane (H2L) and lanthanide (III) salts under hydrothermal condition and structurally characterized by single-crystal X-ray diffractions. In complexes 1 and 2, the L2- anions adopt three different coordination fashions (bidentate chelate, bidentate bridging and bidentate chelate bridging) connecting Ln(III) ions via the oxygen atoms from carboxylate moieties. Both 1 and 2 exhibit 3D network structures with 2-fold interpenetration. Interestingly, the reversible desorption-adsorption behavior of lattice water is significantly observed in the two compounds. The result shows their potential application as late-model water absorbent in the field of adsorption material. - Graphical abstract: Two inorganic-organic 3D network, namely {[Ln(L)1.5(H2O)2].5H2O}n [Ln=Y (1), Ce (2)], have been prepared under hydrothermal condition and structurally characterized by single-crystal X-ray diffractions. Both 1 and 2 exhibit 3D network structures with 2-fold interpenetration. Interestingly, the reversible desorption-adsorption behavior of lattice water is significantly observed in the two compounds. The result shows their potential application as late-model water absorbent in the field of adsorption material.

  7. Vasectomy Reversal

    Medline Plus

    Full Text Available ... is a realistic option for many patients. Today we are going to go to the operating room and show you microsurgical vasectomy reversal. We start the procedure by localizing the site of ...

  8. Vasectomy Reversal

    Medline Plus

    Full Text Available ... keep the vas well vascularized because ischemia will cause fibrosis and scarring and prevent the vasectomy reversal ... to make sure that we don't inadvertently cause any vascular to the vas or even to ...

  9. Vasectomy Reversal

    Medline Plus

    Full Text Available ... improving health. Hello, my name is Harris Nagler. I'm the Chairman of the Sol and Margaret ... Israel Medical Center in New York City. Today I'm going to perform a vasectomy reversal using ...

  10. Vasectomy Reversal

    Medline Plus

    Full Text Available ... Today we are going to go to the operating room and show you microsurgical vasectomy reversal. We ... vas and that will be examined under the operating- under the microscope to see if there’s sperm ...

  11. Reversible Sterilization

    Science.gov (United States)

    Largey, Gale

    1977-01-01

    Notes that difficult questions arise concerning the use of sterilization for alleged eugenic and euthenic purposes. Thus, how reversible sterilization will be used with relation to the poor, mentally ill, mentally retarded, criminals, and minors, is questioned. (Author/AM)

  12. Vasectomy Reversal

    Medline Plus

    Full Text Available Vasectomy Reversal Beth Israel Medical Center, New York, NY February 19, 2009 Welcome to this "OR Live" Webcast presentation premiering from Beth Israel Medical Center in New York City. ...

  13. Vasectomy Reversal

    Medline Plus

    Full Text Available Vasectomy Reversal Beth Israel Medical Center, New York, NY February 19, 2009 Welcome to this "OR Live" Webcast presentation premiering from Beth Israel Medical Center in New York City. During the ...

  14. Disinfection Byproduct Formation in Reverse-Osmosis Concentrated and Lyophilized Natural Organic Matter from a Drinking Water Source

    Science.gov (United States)

    Drinking water treatment and disinfection byproduct (DBP) research can be complicated by natural organic matter (NOM) temporal variability. NOM preservation by lyophilization (freeze-drying) has been long practiced to address this issue; however, its applicability for drinking wa...

  15. Hydrogen production from inexhaustible supplies of fresh and salt water using microbial reverse-electrodialysis electrolysis cells

    OpenAIRE

    Kim, Younggy; Logan, Bruce E.

    2011-01-01

    There is a tremendous source of entropic energy available from the salinity difference between river water and seawater, but this energy has yet to be efficiently captured and stored. Here we demonstrate that H2 can be produced in a single process by capturing the salinity driven energy along with organic matter degradation using exoelectrogenic bacteria. Only five pairs of seawater and river water cells were sandwiched between an anode, containing exoelectrogenic bacteria, and a cathode, for...

  16. Behavior of pharmaceuticals and drugs of abuse in a drinking water treatment plant (DWTP) using combined conventional and ultrafiltration and reverse osmosis (UF/RO) treatments

    Energy Technology Data Exchange (ETDEWEB)

    Boleda, Ma Rosa [AGBAR-Aiguees de Barcelona, Gral Batet 5-7, 08028 Barcelona (Spain); Galceran, Ma Teresa [University of Barcelona, Department Analytical Chemistry, Av. Diagonal 647, 08028 Barcelona (Spain); Ventura, Francesc, E-mail: fventura@agbar.es [AGBAR-Aiguees de Barcelona, Gral Batet 5-7, 08028 Barcelona (Spain)

    2011-06-15

    The behavior along the potabilization process of 29 pharmaceuticals and 12 drugs of abuse identified from a total of 81 compounds at the intake of a drinking water treatment plant (DWTP) has been studied. The DWTP has a common treatment consisting of dioxychlorination, coagulation/flocculation and sand filtration and then water is splitted in two parallel treatment lines: conventional (ozonation and carbon filtration) and advanced (ultrafiltration and reverse osmosis) to be further blended, chlorinated and distributed. Full removals were reached for most of the compounds. Iopromide (up to 17.2 ng/L), nicotine (13.7 ng/L), benzoylecgonine (1.9 ng/L), cotinine (3.6 ng/L), acetaminophen (15.6 ng/L), erythromycin (2.0 ng/L) and caffeine (6.0 ng/L) with elimination efficiencies {>=}94%, were the sole compounds found in the treated water. The advanced treatment process showed a slightly better efficiency than the conventional treatment to eliminate pharmaceuticals and drugs of abuse. - Highlights: > The presence of pharmaceuticals and drugs of abuse in surface water was demonstrated. > Elimination in both potabilization processes reached levels >99% for most compounds. > Four pharmaceuticals and three drugs of abuse survived the potabilization process. - The efficiency of potabilization processes to eliminate or transform pharmaceuticals and illicit drugs is evaluated.

  17. Lidar Observations of Low-level Wind Reversals over the Gulf of Lion and Characterization of Their Impact on the Water Vapour Variability

    Science.gov (United States)

    Di Girolamo, Paolo; Flamant, Cyrille; Cacciani, Marco; Summa, Donato; Stelitano, Dario; Mancini, Ignazio; Richard, Evelyne; Ducrocq, Véronique; Nuret, Mathieu; Said, Frédérique

    2016-06-01

    Water vapour measurements from a ground-based Raman lidar and an airborne differential absorption lidar, complemented by high resolution numerical simulations from two mesoscale models (Arome-WMED and MESO-NH), are considered to investigate transition events from Mistral/Tramontane to southerly marine flow taking place over the Gulf of Lion in Southern France in the time frame September-October 2012, during the Hydrological Cycle in the Mediterranean Experiment (HyMeX) Special Observation Period 1 (SOP1). Low-level wind reversals associated with these transitions are found to have a strong impact on water vapour transport, leading to a large variability of the water vapour vertical and horizontal distribution. The high spatial and temporal resolution of the lidar data allow to monitor the time evolution of the three-dimensional water vapour field during these transitions from predominantly northerly Mistral/Tramontane flow to a predominantly southerly flow, allowing to identify the quite sharp separation between these flows, which is also quite well captured by the mesoscale models.

  18. Behavior of pharmaceuticals and drugs of abuse in a drinking water treatment plant (DWTP) using combined conventional and ultrafiltration and reverse osmosis (UF/RO) treatments

    International Nuclear Information System (INIS)

    The behavior along the potabilization process of 29 pharmaceuticals and 12 drugs of abuse identified from a total of 81 compounds at the intake of a drinking water treatment plant (DWTP) has been studied. The DWTP has a common treatment consisting of dioxychlorination, coagulation/flocculation and sand filtration and then water is splitted in two parallel treatment lines: conventional (ozonation and carbon filtration) and advanced (ultrafiltration and reverse osmosis) to be further blended, chlorinated and distributed. Full removals were reached for most of the compounds. Iopromide (up to 17.2 ng/L), nicotine (13.7 ng/L), benzoylecgonine (1.9 ng/L), cotinine (3.6 ng/L), acetaminophen (15.6 ng/L), erythromycin (2.0 ng/L) and caffeine (6.0 ng/L) with elimination efficiencies ≥94%, were the sole compounds found in the treated water. The advanced treatment process showed a slightly better efficiency than the conventional treatment to eliminate pharmaceuticals and drugs of abuse. - Highlights: → The presence of pharmaceuticals and drugs of abuse in surface water was demonstrated. → Elimination in both potabilization processes reached levels >99% for most compounds. → Four pharmaceuticals and three drugs of abuse survived the potabilization process. - The efficiency of potabilization processes to eliminate or transform pharmaceuticals and illicit drugs is evaluated.

  19. Determination of diallyldimethylammonium chloride in drinking water by reversed-phase ion-pair chromatography-electrospray ionization mass spectrometry.

    Science.gov (United States)

    Jin, Fen; Hu, Jianying; Yang, Min; Jin, Xiaohui; He, Wenjie; Han, Hongda

    2006-01-01

    A method for the direct determination of diallyldimethylammonium chloride (DADMAC) in water samples, using ion-pair liquid chromatography-mass spectrometry system was developed. The chromatographic separation was performed using a C18 column. The type, the concentration of ion-pair reagent and the pH were optimized to give good chromatographic retention and sensitivity for DADMAC. Quantification was achieved in the positive electrospray ionization mode using selected ion monitoring. The cone voltage was also studied to establish the optimal experimental conditions. Finally, the reproducibility of the proposed method was shown by good run-to-run and day-to-day precision values. No sample preparation was required and the detection limit was 0.1 microg/L. The method was used to detect residual DADMAC at drinking water treatment plants in Tianjin, north China. The concentration of DADMAC observed in drinking water ranged from below quantitation limit to 22.0 microg/L. PMID:16243342

  20. Time reversal communication system

    Science.gov (United States)

    Candy, James V.; Meyer, Alan W.

    2008-12-02

    A system of transmitting a signal through a channel medium comprises digitizing the signal, time-reversing the digitized signal, and transmitting the signal through the channel medium. The channel medium may be air, earth, water, tissue, metal, and/or non-metal.

  1. Effect of urea on bovine serum albumin in aqueous and reverse micelle environments investigated by small angle X-ray scattering, fluorescence and circular dichroism

    International Nuclear Information System (INIS)

    The influence that urea has on the conformation of water-soluble globular protein, bovine serum albumin (BSA), exposed directly to the aqueous solution as compared to the condition where the macromolecule is confined in the Aerosol-OT (AOT - sodium bis-2-ethylhexyl sulfosuccinate)/n-hexane/water reverse micelle (RM) is addressed. Small angle X-ray scattering (SAXS), tryptophan (Trp) fluorescence emission and circular dichroism (CD) spectra of aqueous BSA solution in the absence and in the presence of urea (3M and 5M) confirm the known denaturing effect of urea in proteins. The loss of the globular native structure is observed by the increase in the protein maximum dimension and gyration radius, through the Trp emission increase and maximum red-shift as well as the decrease in helix content. In RMs, the Trp fluorescence and CD spectra show that BSA is mainly located in its interfacial region independently of the micellar size. Addition of urea in this BSA/RM system also causes changes in the Trp fluorescence (emission decrease and maximum red-shift) and in the BSA CD spectra (decrease in helix content), which are compatible with the denaturation of the protein and Trp exposition to a more apolar environment in the RM. The fact that urea causes changes in the protein structure when it is located in the interfacial region (evidenced by CD) is interpreted as an indication that the direct interaction of urea with the protein is the major factor to explain its denaturing effect. (author)

  2. Two-step preparation of nano-scaled magnetic chitosan particles using Triton X-100 reversed-phase water-in-oil microemulsion system

    International Nuclear Information System (INIS)

    Highlights: •A new two-step route for nano-scaled magnetic chitosan particles preparation. •Triton X-100 reversed-phase microemulsion system was used for chitosan coating. •Narrow size distribution of magnetic chitosan nanoparticles was achieved. •Quantitative evaluation of recoverability for the magnetic chitosan nanoparticles. -- Abstract: A new two-step route for the preparation of nano-scaled magnetic chitosan particles has been developed, different from reported one-step in situ preparation and two-step preparation method of reversed-phase suspension, Triton X-100 reversed-phase water-in-oil microemulsion encapsulation method was employed in coating the pre-prepared Fe3O4 nanoparticles with chitosan. The resultant magnetic chitosan particles owned a narrow size distribution ranging from 50 to 92 nm. X-ray diffraction patterns (XRD) indicated that the chitosan coating procedure did not change the spinal structure of Fe3O4 magnetic nanoparticles. The results of Fourier transform infrared (FTIR) analysis and thermogravimetric analysis (TGA) demonstrated that the chitosan was coated on Fe3O4 nanoparticles and its average mass content was ∼50%. The saturated magnetization of the magnetic Fe3O4/chitosan nanoparticles reached 18.62 emu/g, meanwhile, the nanoparticles showed the characteristics of superparamagnetism. The magnetic chitosan nanoparticles showed a high recoverability of 99.99% in 10 min when pH exceeded 4. The results suggested that the as-prepared magnetic chitosan particles were nano-scaled with a narrow size distribution and a high recoverability

  3. Two-step preparation of nano-scaled magnetic chitosan particles using Triton X-100 reversed-phase water-in-oil microemulsion system

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Zhengkun; Jiang, Feihong [College of Food Science and Engineering, Northwest A and F University, Yangling, Shaanxi 712100 (China); Lee, Tung-Ching, E-mail: lee@aesop.rutgers.edu [Department of Food Science, Rutgers, the State University of New Jersey, 65 Dudley Road, New Brunswick, NJ 08901 (United States); Yue, Tianli, E-mail: yuetl305@nwsuaf.edu.cn [College of Food Science and Engineering, Northwest A and F University, Yangling, Shaanxi 712100 (China)

    2013-12-25

    Highlights: •A new two-step route for nano-scaled magnetic chitosan particles preparation. •Triton X-100 reversed-phase microemulsion system was used for chitosan coating. •Narrow size distribution of magnetic chitosan nanoparticles was achieved. •Quantitative evaluation of recoverability for the magnetic chitosan nanoparticles. -- Abstract: A new two-step route for the preparation of nano-scaled magnetic chitosan particles has been developed, different from reported one-step in situ preparation and two-step preparation method of reversed-phase suspension, Triton X-100 reversed-phase water-in-oil microemulsion encapsulation method was employed in coating the pre-prepared Fe{sub 3}O{sub 4} nanoparticles with chitosan. The resultant magnetic chitosan particles owned a narrow size distribution ranging from 50 to 92 nm. X-ray diffraction patterns (XRD) indicated that the chitosan coating procedure did not change the spinal structure of Fe{sub 3}O{sub 4} magnetic nanoparticles. The results of Fourier transform infrared (FTIR) analysis and thermogravimetric analysis (TGA) demonstrated that the chitosan was coated on Fe{sub 3}O{sub 4} nanoparticles and its average mass content was ∼50%. The saturated magnetization of the magnetic Fe{sub 3}O{sub 4}/chitosan nanoparticles reached 18.62 emu/g, meanwhile, the nanoparticles showed the characteristics of superparamagnetism. The magnetic chitosan nanoparticles showed a high recoverability of 99.99% in 10 min when pH exceeded 4. The results suggested that the as-prepared magnetic chitosan particles were nano-scaled with a narrow size distribution and a high recoverability.

  4. MesoDyn Simulation Study on Phase Diagram of Aerosol OT/isooctane/water System

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A simple model, i.e. sodium di(2-ethylhexyl) sulfosuccinate (AOT) represented by one-head and two-tail beads tied together by a harmonic spring and water or isooctane by one bead, was put forward via Dissipative Particles Dynamics (DPD) simulation method. Using the changes of interfacial tension between water and oil phase, a ternary phase diagram of AOT/water/isooctane system was drawn. From the simulation, one conclusion is shown that DPD simulation can be considered as an adjunct to experiments.

  5. Evaluating the Efficiency of Different Microfiltration and Ultrafiltration Membranes Used as Pre-treatment for Reverse Osmosis Desalination of Red Sea Water

    KAUST Repository

    AlMashharawi, Samer

    2011-07-01

    . Collectively, results showed that all eight configurations provided permeate with excellent water quality to be fed to reverse osmosis membrane. However, using the 0.1 μm and 100kDa membranes with 1 mg/l FeCl3 concentration, respectively, steadier fluxes correspond to less increment of pumping intensity and better water quality was achieved.

  6. SISGR: Water dynamics in heterogeneous and confined environments: Salt solutions, reverse micelles, and lipid multi-bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, James

    2013-11-05

    Our goal is to understand the structure and dynamics of water, in its different phases, at the interfaces between these phases, and in confined and heterogeneous environments. To this end, linear and nonlinear vibrational spectroscopy is playing a very important role. We have developed techniques for calculating spectroscopic observables, and then used our results to analyze and interpret experiment.

  7. Reaction mechanism of the reverse water-gas shift reaction using first-row middle transition metal catalysts L'M (M = Fe, Mn, Co): a computational study.

    Science.gov (United States)

    Liu, Cong; Cundari, Thomas R; Wilson, Angela K

    2011-09-19

    The mechanism of the reverse water-gas shift reaction (CO(2) + H(2) → CO + H(2)O) was investigated using the 3d transition metal complexes L'M (M = Fe, Mn, and Co, L' = parent β-diketiminate). The thermodynamics and reaction barriers of the elementary reaction pathways were studied with the B3LYP density functional and two different basis sets: 6-311+G(d) and aug-cc-pVTZ. Plausible reactants, intermediates, transition states, and products were modeled, with different conformers and multiplicities for each identified. Different reaction pathways and side reactions were also considered. Reaction Gibbs free energies and activation energies for all steps were determined for each transition metal. Calculations indicate that the most desirable mechanism involves mostly monometallic complexes. Among the three catalysts modeled, the Mn complex shows the most favorable catalytic properties. Considering the individual reaction barriers, the Fe complex shows the lowest barrier for activation of CO(2). PMID:21838224

  8. Synthesis of CuNi/C and CuNi/γ-Al2O3 Catalysts for the Reverse Water Gas Shift Reaction

    Directory of Open Access Journals (Sweden)

    Maxime Lortie

    2015-01-01

    Full Text Available A new polyol synthesis method is described in which CuNi nanoparticles of different Cu/Ni atomic ratios were supported on both carbon and gamma-alumina and compared with Pt catalysts using the reverse water gas shift, RWGS, reaction. All catalysts were highly selective for CO formation. The concentration of CH4 was less than the detection limit. Cu was the most abundant metal on the CuNi alloy surfaces, as determined by X-ray photoelectron spectroscopy, XPS, measurements. Only one CuNi alloy catalyst, Cu50Ni50/C, appeared to be as thermally stable as the Pt/C catalysts. After three temperature cycles, from 400 to 700°C, the CO yield at 700°C obtained using the Cu50Ni50/C catalyst was comparable to that obtained using a Pt/C catalyst.

  9. Preconcentration and Speciation of Trace Mercury Compounds in Water Sample Using Dithizonates Extraction and Reverse Phased Liquid Chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Suh, J.K.; Cho, K.H. [Korea Research Institute of Standards and Science, Taejon (Korea); Lee, S.H. [Kyungpook National University, Taegu (Korea)

    2000-02-01

    A rapid preconcentration method was developed for the speciation of the trace mercury compounds in water sample. The mercury compounds were extracted and preconcentrated simply as their dithizone complexes by passing through the dithizone impregnated ultra-high molecular weight polyethylene (CHMWPE) membrane solvent inlet filter following sonification in methanol solvent. The concentrated dithizonates were separated by liquid chromatography on a C{sub 18} column. Complete resolution was obtained between methyl-, ethyl-, phenyl-, and inorganic mercury with a mobile phase of 0.05 M acetate buffer (pH=4)/THF/methanol(3:5:2). The separated mercury chelates were detected by spectrophotometrically at 475 nm. The proposed method was successfully applied to the speciation of mercury compounds in waste water with detection limit at the subnanogram/mL level. (author). 15 refs., 2 tabs., 8 figs.

  10. Neural network implementation for a reversal procedure for water and dry matter estimation on plant leaves using selected LED wavelengths.

    Science.gov (United States)

    Conejo, Elian; Frangi, Jean-Pierre; de Rosny, Gilles

    2015-06-10

    An inversion method based on a neural network was used to estimate water and dry matter contents on plant leaves, from transmittance and reflectance measurements, using light emitting diodes (LEDs) at specific wavelengths in NIR and FIR. The preliminary results for the predicted water content by the neural network method showed a RMSE value of 0.0027 g/cm(2) and |σ| value of approximately 3.53%, computed on 127 plant leaf samples over 51 species. Dry matter estimation also was performed, which showed potential implementation after future improvements. We believe this inversion method could be implemented in a portable system based on any silicon platform with the capability to perform in situ measurements on plant tissue. PMID:26192847

  11. RO膜反渗透水处理技术在煤矿的应用%Application of RO reverses osmosis membrane water treatment technology in coal mine

    Institute of Scientific and Technical Information of China (English)

    秦俏; 周吾昆; 张政

    2015-01-01

    using RO reverse osmosis water treatment technology for the advanced treatment, provides a more secure and efficient method to reduce the funds loss caused by hydraulic support and other large hydraulic equipment corrosion. The method, compared with the traditional method, has the high impurity removal rate, the neutrality of Yin and Yang ion is good, the water after treatment can reach the standard of pure water ,and can be drunk directly.%利用RO膜精密反渗透水处理技术对矿井水进行深度处理,为有效降低液压支架等大型液压设备腐蚀锈蚀造成的资金损耗提供了一种更加安全高效的方法与工艺。其处理方法与传统方法相比杂质去除率高、阴阳离子中和性好、处理后的水达到纯净水标准可直接饮用。

  12. Synthesis and Characterization of Poly(arylene ether sulfone)s for Reverse Osmosis Water Purification and Gas Separation Membranes

    OpenAIRE

    Sundell, Benjamin James

    2014-01-01

    Crosslinking is an effective technique for increasing the salt rejection of water purification membranes and the selectivity of gas separation membranes. An abundance of monomers, telechelic oligomers, and novel polymers were synthesized for use as separation membranes. These materials were often imbued with crosslinking functionalities to increase their performance during testing at the University of Texas-Austin. Crosslinking of sulfonated poly(arylene ether sulfone) oligomers was stud...

  13. Decreased proliferation in the adult rat hippocampus after exposure to the Morris water maze and its reversal by fluoxetine

    Czech Academy of Sciences Publication Activity Database

    Náměstková, Kateřina; Šimonová, Zuzana; Syková, Eva

    2005-01-01

    Roč. 163, č. 1 (2005), s. 26-32. ISSN 0166-4328 R&D Projects: GA ČR(CZ) GA304/03/1189; GA MŠk(CZ) LN00A065 Institutional research plan: CEZ:AV0Z50390512 Keywords : Antidepressant * Water maze * Neurogenesis Subject RIV: FJ - Surgery incl. Transplants Impact factor: 2.865, year: 2005

  14. Ionic liquid-in-oil microemulsions composed of double chain surface active ionic liquid as a surfactant: temperature dependent solvent and rotational relaxation dynamics of coumarin-153 in [Py][TF2N]/[C4mim][AOT]/benzene microemulsions.

    Science.gov (United States)

    Rao, Vishal Govind; Mandal, Sarthak; Ghosh, Surajit; Banerjee, Chiranjib; Sarkar, Nilmoni

    2012-07-19

    [Py][TF2N]-containing microemulsions is very small compared to the increase in solvation time on going from pure water to water-containing microemulsions. The average solvation time decreases with increasing R values at 298 K, but it shows only a small R dependence compared to microemulsions containing solvents capable of forming hydrogen bonds. We have also shown that the temperature has substantial effect on the solvent and rotational relaxation of C-153 in neat [Py][TF2N] compared to that of [Py][TF2N]/[C4mim][AOT]/benzene microemulsions at R = 0.69. PMID:22721252

  15. Positronium formation and annihilation in BHDC/water/benzene microemulsions

    International Nuclear Information System (INIS)

    Positron lifetime measurements have been made on BHDC/water/benzene microemulsions, at different water to surfactant molar ratios (w0) and different surfactant concentrations (CBHDC). Recently, a model has been proposed to explain the positronium formation and annihilation in AOT/water/isooctane microemulsions, which states that the majority of positronium formation occurs in the aqueous cores of the reverse micelles, and the o-Ps there formed diffuses out of the aqueous cores into the organic solvent bulk. The BHDC based microemulsion system has been chosen in order to study the influence of the cationic head group and of the chloride counterion present in the aqueous pseudophase on the Ps formation probability and on the o-Ps diffusion out of the aqueous cores. The results of this study are satisfactorily explained by the referred model. The radii of the aqueous cores for different w0 values and calculated from the o-Ps lifetime measurements, are in good agreement with the values reported in the literature. The measured o-Ps intensities in both the aqueous pseudophase and the organic phase were found to be in agreement with those calculated by taking into account the partial inhibition due to the chloride counterions present in the aqueous cores. (orig.)

  16. Synthesis and characterization of nanodispersed molecular aggregates of Prussian blue in aerosol OT reverse micelle.

    Science.gov (United States)

    Pramanik, Smritimoy; Das, Debasmita; Das, Kaushik; Bhattacharya, Subhash Ch

    2007-02-01

    Prussian Blue (PB) nanomolecular aggregates were prepared in a well-characterized, monodispersed biomimicking nanocavities formed by Aerosol OT (AOT) reverse micelle in H2O/AOT/heptane at different omega ([H2O]/[Surfactant]) employing coprecipitation technique. The formed nanomolecular aggregates of PB have been characterized by the UV-visible, Fourier Transformed Infrared (FTIR) spectroscopy as well as by Transmission Electron Microscopy (TEM) and Cyclic Voltammetric methods. Visible and FTIR spectroscopic measurements confirm the formation of PB nano aggregates. Experimental results reveal that the molar extinction coefficient of PB nanomolecular aggregates is different for two different regimes of omega of reverse micelles. TEM measurements show that the size of these reverse micellar entrapped nano aggregrates varied with hydration (omega). Studies on these nano sized particles indicate that Fe is present in a single mixed valence state along the Fe-C-N-Fe skeleton in PB and the half wave potential (E1/2) becomes more positive with increase in the size of the nano aggregates. PMID:17450811

  17. Reversible, Selective Trapping of Perchlorate from Water in Record Capacity by a Cationic Metal-Organic Framework.

    Science.gov (United States)

    Colinas, Ian R; Silva, Rachel C; Oliver, Scott R J

    2016-02-16

    We report the capture of ppm-level aqueous perchlorate in record capacity and kinetics via the complete anion exchange of a cationic metal-organic framework. Ambient conditions were used for both the synthesis of silver 4,4'-bipyridine nitrate (SBN) and the exchange, forming silver 4,4'-bipyridine perchlorate (SBP). The exchange was complete within 90 min, and the capacity was 354 mg/g, representing 99% removal. These values are greater than current anion exchangers such as the resins Amberlite IRA-400 (249 mg/g), Purolite A530E (104 mg/g), and layered double hydroxides (28 mg/g). Moreover, unlike resins and layered double hydroxides, SBN is fully reusable and displays 96% regeneration to SBN in nitrate solution, with new crystal formation allowing the indefinite cycling for perchlorate. We show seven cycles as proof of concept. Perchlorate contamination of water represents a serious health threat because it is a thyroid endocrine disruptor. This noncomplexing anionic pollutant is significantly mobile and environmentally persistent. Removal of other anionic pollutants from water such as chromate, pertechnetate, or arsenate may be possible by this methodology. PMID:26765213

  18. Severe 2010 Cold-Water Event Caused Unprecedented Mortality to Corals of the Florida Reef Tract and Reversed Previous Survivorship Patterns

    Science.gov (United States)

    Lirman, Diego; Schopmeyer, Stephanie; Manzello, Derek; Gramer, Lewis J.; Precht, William F.; Muller-Karger, Frank; Banks, Kenneth; Barnes, Brian; Bartels, Erich; Bourque, Amanda; Byrne, James; Donahue, Scott; Duquesnel, Janice; Fisher, Louis; Gilliam, David; Hendee, James; Johnson, Meaghan; Maxwell, Kerry; McDevitt, Erin; Monty, Jamie; Rueda, Digna; Ruzicka, Rob; Thanner, Sara

    2011-01-01

    Background Coral reefs are facing increasing pressure from natural and anthropogenic stressors that have already caused significant worldwide declines. In January 2010, coral reefs of Florida, United States, were impacted by an extreme cold-water anomaly that exposed corals to temperatures well below their reported thresholds (16°C), causing rapid coral mortality unprecedented in spatial extent and severity. Methodology/Principal Findings Reef surveys were conducted from Martin County to the Lower Florida Keys within weeks of the anomaly. The impacts recorded were catastrophic and exceeded those of any previous disturbances in the region. Coral mortality patterns were directly correlated to in-situ and satellite-derived cold-temperature metrics. These impacts rival, in spatial extent and intensity, the impacts of the well-publicized warm-water bleaching events around the globe. The mean percent coral mortality recorded for all species and subregions was 11.5% in the 2010 winter, compared to 0.5% recorded in the previous five summers, including years like 2005 where warm-water bleaching was prevalent. Highest mean mortality (15%–39%) was documented for inshore habitats where temperatures were climatic events can have on the persistence of coral reefs. Moreover, habitats and species most severely affected were those found in high-coral cover, inshore, shallow reef habitats previously considered the “oases” of the region, having escaped declining patterns observed for more offshore habitats. Thus, the 2010 cold-water anomaly not only caused widespread coral mortality but also reversed prior resistance and resilience patterns that will take decades to recover. PMID:21853066

  19. Salt-dependent increase in triterpenoids is reversible upon transfer to fresh water in mangrove plants Kandelia candel and Bruguiera gymnorrhiza.

    Science.gov (United States)

    Basyuni, Mohammad; Baba, Shigeyuki; Kinjo, Yuji; Putri, Lollie A P; Hakim, Luthfi; Oku, Hirosuke

    2012-12-15

    This study examined the salinity dependence of triterpenoid content and triterpenoid synthase gene expression in mangrove plants, Kandelia candel and Bruguiera gymnorrhiza (Rhizophoraceae) after long-term exposure to salinity and subsequent re-adaptation. Seedlings of the two mangrove species grown in varying salt concentrations for 4 months were divided into two treatment groups and grown for another 4 months, one group continued under the respective saline condition and the other in fresh water for re-adaptation. The total content of triterpenoids increased with increasing salinity in roots and leaves of K. candel, but only in roots in B. gymnorrhiza. This increase was reversed to a variable extent, depending on the species and organ, after transfer to fresh water. In contrast, the total content of phytosterols showed no correlation with salinity throughout the experiment. The increase in total triterpenoids was accompanied by an up-regulation of several triterpenoid synthase genes: KcMS, a multifunctional triterpenoid synthase, in roots and leaves of K. candel and BgLUS, a lupeol synthase, and BgbAS, a β-amyrin synthase, in roots of B. gymnorrhiza. The expression of root KcCAS, a cycloartenol synthase, which is involved in phytosterol biosynthesis, was not modulated by the salinity conditions but decreased with increasing salinity in leaves, followed by the restoration to the initial level after transfer to fresh water. The concentrations of individual triterpenoids, but not of phytosterols, in the roots positively correlated with the salinity. These results reinforced the importance of triterpenoids in the adaptation of mangroves to withstand salt and/or water stress. PMID:22921677

  20. Possible role of laccase from Fusarium incarnatum UC-14 in bioremediation of Bisphenol A using reverse micelles system.

    Science.gov (United States)

    Chhaya, Urvish; Gupte, Akshaya

    2013-06-15

    Bisphenol A [2,2 bis (4 hydroxyphenyl) propane] is widely used in the variety of industrial and residential applications such as the synthesis of polymers including polycarbonates, epoxy resins, phenol resins, polyesters and polyacrylates. BPA has been recognized as an Endocrine Disrupting Chemicals (EDC), thus it is necessary to assess its biodegradability or fate in the natural environment. In general, environmental pollutant such as BPA does not dissolve in aqueous media, owing to their high hydrophobicity, and hence non-aqueous catalysis can be employed to enhance biodegradability of phenolic environmental pollutant. Purified laccase hosted in reverse micelles using ternary system of isooctane: AOT [Bis (2-ethylhexyl) sulphosuccinate sodium salt)]:water having hydration ratio (Wo) of 30 with protein concentration of 43.5 μg/ml was found to eliminate 91.43% of 200 ppm of Bisphenol A at 50 °C, pH-6.0 when incubated with laccase/Reverse Micelles system for 75 min. GC-MS analysis of isooctane soluble fractions detected the presence of 4,4'-(2 hydroxy propane 1,2 diyl) diphenol, bis (4-hydroxylphenyl) butenal and 2-(1-(4-hydroxyphenyl) vinyl) pent-2-enal indicated degradation of BPA by two oxidation steps and one ring opening step (C-C bond cleavage). Laccase/RM system exhibited several advantages for the oxidative degradation of hydrophobic phenols mainly because of the solubility of either enzyme or substrate was improved in organic media and the stable activity of laccase in organic media was achieved. PMID:23611799

  1. Enzyme recovery using reversed micelles.

    OpenAIRE

    Dekker, M.

    1990-01-01

    The objective of this study was to develop a liquid-liquid extraction process for the recovery of extracellular enzymes. The potentials of reaching this goal by using reversed micelles in an organic solvent have been investigated.Reversed micelles are aggregates of surfactant molecules containing an inner core of water molecules, dispersed in a continuous organic solvent medium. The considerable biotechnological potential of these systems is derived principally from the ability of the water d...

  2. Reversible dementias

    OpenAIRE

    Tripathi, Manjari; Vibha, Deepti

    2009-01-01

    In recent years, more attention has been given to the early diagnostic evaluation of patients with dementia which is essential to identify patients with cognitive symptoms who may have treatable conditions. Guidelines suggest that all patients presenting with dementia or cognitive symptoms should be evaluated with a range of laboratory tests, and with structural brain imaging with computed tomography (CT) or magnetic resonance imaging (MRI). While many of the disorders reported as ‘reversible...

  3. FATE OF REVERSE OSMOSIS (RO) MEMBRANES DURING OXIDATION BY DISINFECTANTS USED IN WATER TREATMENT: IMPACT ON MEMBRANE STRUCTURE AND PERFORMANCES

    KAUST Repository

    Maugin, Thomas

    2013-12-01

    Providing pretreatment prior RO filtration is essential to avoid biofouling and subsequent loss of membrane performances. Chlorine is known to degrade polymeric membrane, improving or reducing membrane efficiency depending on oxidation conditions. This study aimed to assess the impact of alternative disinfectant, NH2Cl, as well as secondary oxidants formed during chloramination of seawater, e.g. HOBr, HOI, or used in water treatment e.g. ClO2, O3, on membrane structure and performances. Permeability, total and specific rejection (Cl-, SO4 2-, Br-, Boron), FTIR profile, elemental composition were analyzed. Results showed that each oxidant seems to react differently with the membrane. HOCl, HOBr, ClO2 and O3 improved membrane permeability but decreased rejection in different extent. In comparison, chloramines resulted in identical trends but oxidized membrane very slowly. On the contrary, iodine improved membrane rejection e.g. boron, but decreased permeability. Reaction conducted with chlorine, bromine, iodine and chloramines resulted in the incorporation of halogen in the membrane structure. All oxidant except iodine were able to break amide bonds of the membrane structure in our condition. In addition, chloramine seemed to react with membrane differently, involving a potential addition of nitrogen. Chloramination of seawater amplified membrane performances evolutions due to generation of bromochloramine. Moreover, chloramines reacted both with NOM and membrane during oxidation in natural seawater, leading to additional rejection drop.

  4. Preliminary design of seawater and brackish water reverse osmosis desalination systems driven by low-temperature solar organic Rankine cycles (ORC)

    International Nuclear Information System (INIS)

    In this paper, the coupling between the low-temperature solar organic Rankine cycle (ORC) and seawater and brackish water reverse osmosis desalination units has been carried out. Four substances have been considered as working fluids of the solar cycle (butane, isopentane, R245fa and R245ca). With these four fluids the volumetric flow of fresh water produced per unit of aperture area of stationary solar collector has been calculated. The former has been made with the optimized direct vapour generation (DVG) configuration and heat transfer fluid (HTF) configuration of the solar ORC. In the first one (DVG), working fluid of the ORC is directly heated inside the absorber of the solar collector. In the second one (HTF), a fluid different than the working fluid of the ORC (water in this paper) is heated without phase change inside the absorber of the solar collector. Once this fluid has been heated it is carried towards a heat exchanger where it is cooled. Thermal energy delivered in this cooling process is transferred to the working fluid of the ORC. Influence of condensation temperature of the ORC and regeneration's process effectiveness over productivity of the system has also been analysed. Finally, parameters of several preliminary designs of the low-temperature solar thermal driven RO desalination are supplied. R245fa is chosen as working fluid of the ORC in these preliminary designs. The information of the proposed preliminary designs can also be used, i.e., for the assessment of the use of thermal energy rejected by the solar cycle. Overall analysis of the efficiency of the solar thermal driven RO desalination technology is given with the results presented in this paper and the results obtained with the medium temperature solar thermal RO desalination system presented by the authors in previous papers. This work has been carried out within the framework of the OSMOSOL and POWERSOL projects.

  5. Linear modeling of the soil-water partition coefficient normalized to organic carbon content by reversed-phase thin-layer chromatography.

    Science.gov (United States)

    Andrić, Filip; Šegan, Sandra; Dramićanin, Aleksandra; Majstorović, Helena; Milojković-Opsenica, Dušanka

    2016-08-01

    Soil-water partition coefficient normalized to the organic carbon content (KOC) is one of the crucial properties influencing the fate of organic compounds in the environment. Chromatographic methods are well established alternative for direct sorption techniques used for KOC determination. The present work proposes reversed-phase thin-layer chromatography (RP-TLC) as a simpler, yet equally accurate method as officially recommended HPLC technique. Several TLC systems were studied including octadecyl-(RP18) and cyano-(CN) modified silica layers in combination with methanol-water and acetonitrile-water mixtures as mobile phases. In total 50 compounds of different molecular shape, size, and various ability to establish specific interactions were selected (phenols, beznodiazepines, triazine herbicides, and polyaromatic hydrocarbons). Calibration set of 29 compounds with known logKOC values determined by sorption experiments was used to build simple univariate calibrations, Principal Component Regression (PCR) and Partial Least Squares (PLS) models between logKOC and TLC retention parameters. Models exhibit good statistical performance, indicating that CN-layers contribute better to logKOC modeling than RP18-silica. The most promising TLC methods, officially recommended HPLC method, and four in silico estimation approaches have been compared by non-parametric Sum of Ranking Differences approach (SRD). The best estimations of logKOC values were achieved by simple univariate calibration of TLC retention data involving CN-silica layers and moderate content of methanol (40-50%v/v). They were ranked far well compared to the officially recommended HPLC method which was ranked in the middle. The worst estimates have been obtained from in silico computations based on octanol-water partition coefficient. Linear Solvation Energy Relationship study revealed that increased polarity of CN-layers over RP18 in combination with methanol-water mixtures is the key to better modeling of

  6. Preparation of ZrO2 nano-particles by the hydrolysis of ZrOCl2 solution in the reverse micelles

    Institute of Scientific and Technical Information of China (English)

    Chensha Li; Tongxiang Liang; Tianyong Luo

    2006-01-01

    Zirconia nano-particles have been produced by the hydrolysis of ZrOGl2 solution in the reverse micelles of a liquid-liquid two-phase system, in which sodium bis(2-ethylhexyl) sulfosuccinite (AOT) and toluene were chosen as the surfactant and organic phase, respectively. The reverse micelles prevented the aggregation of primary particles and reduced the diameters of zirconia nanoparticles. Superfine zirconia powders soft-aggregated by the zirconia nano-particles were obtained. The diameters of zirconia nanoparticles were influenced by the quantity of the surfactant.

  7. Reversible Statistics

    DEFF Research Database (Denmark)

    Tryggestad, Kjell

    2004-01-01

    The study aims is to describe how the inclusion and exclusion of materials and calculative devices construct the boundaries and distinctions between statistical facts and artifacts in economics. My methodological approach is inspired by John Graunt's (1667) Political arithmetic and more recent work...... within constructivism and the field of Science and Technology Studies (STS). The result of this approach is here termed reversible statistics, reconstructing the findings of a statistical study within economics in three different ways. It is argued that all three accounts are quite normal, albeit in...... different ways. The presence and absence of diverse materials, both natural and political, is what distinguishes them from each other. Arguments are presented for a more symmetric relation between the scientific statistical text and the reader. I will argue that a more symmetric relation can be achieved by...

  8. Artificial neural network modelling of retention of pesticides in various octadecylsiloxane-bonded reversed-phase columns and water-acetonitrile mobile phase

    International Nuclear Information System (INIS)

    Previously, retention of 26 pesticides in the reversed-phase column Gemini (Phenomenex) and water-acetonitrile mobile phase was modelled using a feed-forward artificial neural network (ANN) learned by error back-propagation, accounting for both the effect of solute structure and mobile phase composition. To this end, log Kow of solutes and four quantum chemical molecular descriptors (the dipole moment, the mean polarizability, the anisotropy of the polarizability and an hydrogen-bonding descriptor based on the atomic charges located on the acid and basic functional groups) and acetonitrile % (v/v) in the eluent (%ACN) were used as ANN inputs. The above ANN-based approach is here tested on further five similar octadecylsiloxane-bonded columns in water-acetonitrile mobile phase within the %ACN range 30-70%. A quite good predictive performance evaluated on three external solutes in the whole %ACN range is observed, prediction errors being lower than ±0.1 log k units or slightly higher although still within ±0.15 log k units. On the other hand, multilinear regression used in place of ANN provides a more diffuse and non-uniform residual distribution for all the investigated columns. ANN multiple-column retention prediction is attempted by adding to the above variables a column descriptor defined as the average retention of calibration solutes extrapolated to 100% water. This more general model is built using 16 solutes and five 5-μm columns in calibration, while its predictive performance is tested on the remaining 10 compounds. Under these conditions, prediction errors are generally within ±0.2 log k units regardless of the kind of column. The possibility of cross-column prediction is evaluated by column leave-one-out cross-validation within the five 5-μm stationary phases and on a 4-μm external column. This analysis reveals that accuracy of retention prediction for unknown solutes in unknown columns is acceptable provided that the external column is not very

  9. Process of forming compounds using reverse micelle or reverse microemulsion systems

    Science.gov (United States)

    Linehan, John C.; Fulton, John L.; Bean, Roger M.

    1998-01-01

    The present invention is directed to a process for producing a nanometer-sized metal compound. The process comprises forming a reverse micelle or reverse microemulsion system comprising a polar fluid in a non-polar or low-polarity fluid. A first reactant comprising a multi-component, water-soluble metal compound is introduced into the polar fluid in a non-polar or low-polarity fluid. This first reactant can be introduced into the reverse micelle or reverse microemulsion system during formation thereof or subsequent to the formation of the reverse micelle or microemulsion system. The water-soluble metal compound is then reacted in the reverse micelle or reverse microemulsion system to form the nanometer-sized metal compound. The nanometer-sized metal compound is then precipitated from the reverse micelle or reverse microemulsion system.

  10. Sorption-induced reversible oxidation of Fe(2) at the smectite/water interface under strictly anoxic conditions. A Moessbauer spectroscopy study

    International Nuclear Information System (INIS)

    sorption at the clay-water interface occurs in a two steps mechanism: sorption of individual Fe(II) cations, followed by an oxidation of some of them. As a first hypothesis, water could be the oxidizing agent. However in this case, the reversibility of the phenomenon cannot be explained. Thus we proposed, as a second hypothesis, that as pH is increased, protons H+ is removed from the clay surface and, more and more of highly reactive sites acquire steric properties that stabilize Fe(III) relative to Fe(II). This differential affinity induces in turn an Fe-to-clay particle electron transfer. The change in surface site local environment is shown by observed large pH induced change in the sorbed Fe(II) quadrupole splitting distributions. (authors)

  11. Determination of Methanol Increment in Mobile Phase Consisting of Methanol and Water by On-line UV Spectrometry in Reversed Phase Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    GENG,Xin-Du(耿信笃); REGNIER,Fred E(弗莱德 依 瑞格涅尔)

    2002-01-01

    An on-line UV spectrometric method for the quantitative determination of methanol increment of methanol-water in the mobile phase(i.e., ofgreater concentration than that of the mobile phase ) by frontal analysis (FA) of insulin in reversed phase liquid chromatography (RPLC) was presented. When the methanol increment concentration ranged from 0.05% to 0.50%, V( CH3OH)/ V(H2O), a set of elution curves could be obtained at 198 nm by a diode-array detector in the presence of 47% methanol, V(CH3OH)/V(H2O) containing 0.03% hydrochloric acid, V ( CH3OH-H2O ) / V ( HCl ) in the mobile phase. The plateau height of the elution curves of the methanol increment was found to be proportional to the methanol increment in the mobile phase. The methanol increment could be determined on a quantitative basis. When the method was used to investigate the elution curve of insulin by FA in RPLC, a small plateau, being the methanol increment,was detected before the usual insulin plateau of each elution curve. In this case the methanol increment was found to vary with insulin concentration in the mobile phase. When that concentration was between 0.025 mg/mL and 0.30 mg/mL,the methanol increment could be determined in the range from 0.03% to0.19% with a deviation of ±0.02% and a relative deviation of ± 10%. A nuclear magnetic resonance spectrometer (NMR) was also employed to confirm the obtained result. A methodology with a very rigorous experimental procedure for obtaining results of such accuracy is also included.The presented result may be used to prove that a displacement process definitely occurs as insulin is adsorbed by the RPLC stationary phase inFA.

  12. Theoretical studies on the catalysis of the reverse water-gas shift reaction using first-row transition metal beta-diketiminato complexes.

    Science.gov (United States)

    Liu, Cong; Munjanja, Lloyd; Cundari, Thomas R; Wilson, Angela K

    2010-06-01

    The reverse water-gas shift reaction CO(2) + H(2) --> H(2)O + CO has been investigated using a set of homogeneous catalyst models L'M(I) (L' = beta-diketiminate, C(3)N(2)H(5)(-); M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn). The thermodynamics of prototypical reaction pathways were simulated at two levels of theory: B3LYP/6-311+G(d) and B3LYP/aug-cc-pVTZ. The modeled catalytic reaction has been considered in the following steps: coordination of CO(2) by the catalyst to generate a carbon dioxide complex, L'M(CO(2)); scission of L'M(CO(2)) to yield L'M(CO) and L'M(O); L'M(O) hydrogenation to form L'M(H(2)O). The final products, H(2)O and CO, were obtained from the dissociation of L'M(H(2)O) and L'M(CO). All of the reactants, intermediates, and products were modeled, where different possible conformers and multiplicities were identified and considered as potential minima. The reaction enthalpy DeltaH, of all steps for each catalyst as a function of transition metal have been determined. The Mn and Fe catalysts show more thermodynamically accessible pathways than the other catalyst models studied. The overall reaction enthalpy has been determined not only by B3LYP/6-311+G(d) and B3LYP/aug-cc-pVTZ but also via a more rigorous ab initio electron-correlation-based approach, the correlation consistent Composite Approach (ccCA). PMID:20462216

  13. Reverse Osmosis Optimization

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-08-01

    This technology evaluation was prepared by Pacific Northwest National Laboratory on behalf of the U.S. Department of Energy’s Federal Energy Management Program (FEMP). The technology evaluation assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. This evaluation provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption. The evaluation is intended to help facility managers at Federal sites understand the basic concepts of the RO process and system optimization options, enabling them to make informed decisions during the system design process for either new projects or recommissioning of existing equipment. This evaluation is focused on commercial-sized RO systems generally treating more than 80 gallons per hour.

  14. Reverse Osmosis Optimization

    Energy Technology Data Exchange (ETDEWEB)

    McMordie Stoughton, Kate; Duan, Xiaoli; Wendel, Emily M.

    2013-08-26

    This technology evaluation was prepared by Pacific Northwest National Laboratory on behalf of the U.S. Department of Energy’s Federal Energy Management Program (FEMP). ¬The technology evaluation assesses techniques for optimizing reverse osmosis (RO) systems to increase RO system performance and water efficiency. This evaluation provides a general description of RO systems, the influence of RO systems on water use, and key areas where RO systems can be optimized to reduce water and energy consumption. The evaluation is intended to help facility managers at Federal sites understand the basic concepts of the RO process and system optimization options, enabling them to make informed decisions during the system design process for either new projects or recommissioning of existing equipment. This evaluation is focused on commercial-sized RO systems generally treating more than 80 gallons per hour.¬

  15. Aerosol optical thickness and spatial variability along coastal and offshore waters of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Menon, H.B.; Sangekar, N.; Lotliker, A.; Moorthy, K.K.; Vethamony, P.

    Data from the ocean-colour monitor (OCM) on board the Indian Remote Sensing Satellite P4 were used to analyse the spatial and temporal distribution of aerosol optical thickness (AOT) over the coastal and offshore waters of the eastern Arabian Sea...

  16. Effect of water temperature on reverse osmosis unit and countermeasures%水温对反渗透装置运行的影响及对策措施

    Institute of Scientific and Technical Information of China (English)

    陈乾荣; 何驹; 娄伦武; 王启延

    2015-01-01

    This paper sketches obvious effects of water temperature on operation pressure, desalination rate, pressure drop and producing water capacity, it also introduces producing water capacity in winter appears linear decrease with reduction of water temperature in reverse osmosis plants, through heating reverse osmosis feedwater with steam condensate, on condition of no-adding new device and energy consumption which solves producing water capacity low in winter, guaranteed efficiently water demand for follow-up devices.%简述了进水温度对反渗透装置的运行压力、脱盐率、压降以及产水能力影响极为明显,介绍该公司反渗透装置出现了冬季产水量随着水温降低而呈现线性下降的情况,通过换热装置用蒸汽冷凝液加热反渗透进水,在不增加新装置和能耗的前提下解决了冬季产水量少的问题,有效保障了后续装置的用水需求。

  17. OP-7/氯仿反胶束体系的制备及其增溶水量的研究%Study on preparation of OP-7/chloroform reverse micelle systems and their water solubilization performance

    Institute of Scientific and Technical Information of China (English)

    赵群; 陈怡秀; 朱青; 沈炎冰; 邓龙根; 马超; 阎克路

    2013-01-01

    The novel OP-7/chloroform reverse micelle system have been prepared by substituting chloroform for the alkanes of traditional reverse micelle systems,and the water solubilization behaviors of the systems have been investigated.The impact of OP-7' s concentration and the type of cosurfactant on the water solubilization amount of reverse micelle systems and the relationship between the water solubilization amount and the size and the conductivity of the systems were studied.The results showed that both the dosage of OP-7,the type and the concentration of the alcohol as cosufactant affect the water solubilization amount ; at the same time,the size and conductivity of the systems increased with increasing water solubilization amount,the OP-7/n-octanol/chloroform has the maximum water solubilization amount.%以氯仿代替传统的烃类溶剂,制备新型OP-7(非离子表面活性剂)/氯仿反胶束体系,并对该体系的增溶行为进行研究.考察了OP-7的浓度和不同的助表面活性剂对该体系增溶水量的影响及增溶水量与体系的粒径、电导率的关系.结果表明,OP-7的浓度、助表面活性剂醇的种类和用量都影响着体系的增溶水量;同时增溶水量增加,体系的粒径和电导率随之增加,OP-7/正辛醇/氯仿反胶束体系增溶水量最大.

  18. Responses of two birch ( Betula pendula Roth) clones to different ozone profiles with similar AOT40 exposure

    Science.gov (United States)

    Oksanen, Elina; Holopainen, Toini

    Saplings of two clones of European white birch ( Betula pendula Roth) were exposed to three different ozone profiles resulting in same AOT40 value of 13-14 ppm h in a chamber experiment. The sensitive clone 5 and the more tolerant clone 2 were growing (1) under filtered air (=control), or (2) were exposed to 70 ppb ozone for 24 h d -1 (=profile 1), (3) to 100 ppb ozone for 12 h d -1 at 8:00-20:00 (=profile 2), or (4) to 200 ppb ozone for 4.5 h d -1 at 9:30-14:00 (=profile 3) for 20 d. The saplings were determined for growth, visible leaf injuries, stomatal conductance, and concentrations of Rubisco, chlorophyll and carotenoids. Growth responses and induction of visible foliar injuries under different ozone profiles were variable, resulting in 4-17% lower dry mass of shoot, 16-46% reduction in stem height increment and 11-43% increase in visible injuries in clone 5, which was accompanied by higher leaf turnover rate under profile 3 indicating compensation growth. In clone 2, ozone-induced responses ranged from slight stimulation in stem height growth to 13% decrease in dry mass of shoot and 2-16% increase in visible injuries. Daytime stomatal conductance rates were lowered by 14-54% in clone 5 and 9-74% in clone 2, depending on profile. The additional power-weighted analyses revealed that high peak concentrations and exposure shape were important for induction of visible injuries in both clones and reduction in stomatal conductance in clone 5, whereas growth reductions were rather related to total cumulative exposure. The results indicate that profile of ozone exposure, night-time stomatal conductance (24 h flux), and recovery time for defence and compensations reactions should not be ignored in plant response and ozone flux modelling.

  19. Renewable synthesis-gas-production. Do hydrocarbons in the reactant flow of the reverse water-gas shift reaction cause coke formation?

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, A.; Kern, C.; Jess, A. [Bayreuth Univ. (Germany). Dept. of Chemical Engineering

    2013-11-01

    In a two-step synthetic fuel production process based on carbon dioxide and renewable hydrogen, the best possible selectivity towards liquid hydrocarbons (Hc) shall be implemented. The process consists of a combination of the Reverse Water-Gas Shift reaction and the Fischer-Tropsch synthesis. To achieve this goal, gaseous short-chained Hc from the FTS reactor are recycled in the RWGS unit. In this paper, challenges coming up with the implementation of a recycle loop are discussed. First of all, it has to be examined whether Hc are converted under conditions present in the RWGS reactor. The coking caused by the recycle of Hc is regarded, including thermal coking in the heating zone of the reactor and catalytic coking in the catalyst bed. Coking of course is unwanted, as it deactivates the catalyst. The scope of this work is to find out to which extent and under which conditions gaseous Hc can be recycled. Therefore, experiments were carried out in both, a quartz glass reactor using a commercial Ni-catalyst at ambient pressure and in a pressurized steel reactor (without catalyst) to examine coking during the thermal decomposition of Hc. The catalytic experiments at atmospheric pressure showed that a recycle of CH{sub 4} did not cause coking up to a ratio of CH{sub 4}/CO{sub 2} below one. For these conditions, long term stability was proved. The reaction rates of the CH{sub 4} conversion were below those of the RWGS reaction. However, replacing CH{sub 4} by C{sub 3}H{sub 8} leads to thermal and catalytic coking. Catalytic coking hits the maximum level at about 700 C and decreases for higher temperatures and, thus is not regarded as a problem for the RWGS reactor. In contrast to that, thermal coking raises with higher temperatures, but it can be supressed efficiently with additional injection of H{sub 2}O, which of course shifts the equilibrium towards the undesired reactant side. (orig.)

  20. The Application of Reverse Osmosis Technology in QingJiang Petrochemical Demineralized Water Process%反渗透技术在清江石化除盐水工艺中的应用

    Institute of Scientific and Technical Information of China (English)

    周健; 华伦

    2012-01-01

    This paper summarizes the structure,producing area and application industry of the Dow reverse osmosis membrane membrane.The technical process,the process control parameters(recovery rate,desalination rate,in-and-out water quality) and process flow and reverse osmosis desalting operation of the reverse osmosis desalting device in Qingjiang petrochemical plant are included.The use of Dow reverse osmosis membrane element,the characteristics and the application,design principle of process,process flow,parameters,and the cleaning frequency in application are also covered.At the same time,some relevant improvement measures are proposed.%综述了陶氏反渗透膜的膜结构、产地及应用行业。阐述了清江石化反渗透脱盐装置的工艺过程、工艺控制参数(回收率、脱盐率、进出水水质)及工艺流程和反渗透脱盐装置的运行情况,包括使用的陶氏反渗透膜元件的特点及应用,设计的工艺原理、流程、参数,以及应用中存在的清洗周期短、制水比居高不下等问题及相关改进措施。

  1. Non-chemical water purification a Westinghouse/Wallenius product for nuclear power plant needs

    International Nuclear Information System (INIS)

    Increasing demand for ecologically effective water treatment technologies has resulted in the development of several new oxidation methods. These technologies are generally labelled Advanced Oxidation Technologies (AOT) or Advanced Oxidation Processes (AOP) and currently represent the most widely recognized alternative for ecologically sound, high-tech water purification. Many years of intensive research have culminated in the innovative Wallenius-AOT technology, a patented method that is remarkable in several ways. It imitates nature's own water purification method. This means no chemical additives are needed. The technology utilizes the ability of light, together with photo-catalytic semiconductor surfaces, to produce free radicals, like nature does. These reactive radicals create an environment in which organic and inorganic substances oxidize, whereby a broad spectrum of organisms is rendered harmless more effectively than with conventional UV technology. The entire process takes just a few micro-seconds. A major advantage of the technology is that it can be adjusted according to the desired degree of purification. By altering the dynamics of the process, the purification can be designed for specific applications. In this way, AOT tackles precise problems, regardless of flow and whether the problem is chemical or biological. The product was originally introduced for ballast treatment in the shipping industry. Ballast water has created severe damages to the biology at many locations. By moving an organism from one ocean to another we have introduced a possible threat to the local ecosystem. This has been prevented by using the AOT water treatment units. During ballasting and de-ballasting, the units create radicals with the help of a catalyst and a light source. These radicals then destroy the cell membrane of microorganisms. The radicals, which never leave the unit, have a lifetime of only a few milliseconds and pose no risk to the environment or crew

  2. A Comparison of Seasonal and Interannual Variability of Soil Dust Aerosols Over the Atlantic Ocean as Inferred by the Toms AI and AVHRR AOT Retrievals

    Science.gov (United States)

    Cakmur, R. V.; Miller, R. L.; Tegen, Ina; Hansen, James E. (Technical Monitor)

    2001-01-01

    The seasonal cycle and interannual variability of two estimates of soil (or 'mineral') dust aerosols are compared: Advanced Very High Resolution Radiometer (AVHRR) aerosol optical thickness (AOT) and Total Ozone Mapping Spectrometer (TOMS) aerosol index (AI), Both data sets, comprising more than a decade of global, daily images, are commonly used to evaluate aerosol transport models. The present comparison is based upon monthly averages, constructed from daily images of each data set for the period between 1984 and 1990, a period that excludes contamination from volcanic eruptions. The comparison focuses upon the Northern Hemisphere subtropical Atlantic Ocean, where soil dust aerosols make the largest contribution to the aerosol load, and are assumed to dominate the variability of each data set. While each retrieval is sensitive to a different aerosol radiative property - absorption for the TOMS AI versus reflectance for the AVHRR AOT - the seasonal cycles of dust loading implied by each retrieval are consistent, if seasonal variations in the height of the aerosol layer are taken into account when interpreting the TOMS AI. On interannual time scales, the correlation is low at most locations. It is suggested that the poor interannual correlation is at least partly a consequence of data availability. When the monthly averages are constructed using only days common to both data sets, the correlation is substantially increased: this consistency suggests that both TOMS and AVHRR accurately measure the aerosol load in any given scene. However, the two retrievals have only a few days in common per month so that these restricted monthly averages have a large uncertainty. Calculations suggest that at least 7 to 10 daily images are needed to estimate reliably the average dust load during any particular month, a threshold that is rarely satisfied by the AVHRR AOT due to the presence of clouds in the domain. By rebinning each data set onto a coarser grid, the availability of

  3. Synthesis of nanosilver particles by reverse micelle method and study of their bactericidal properties

    Energy Technology Data Exchange (ETDEWEB)

    Tran Thi Ngoc Dung; Ngo Quoc Buu; Dang Viet Quang; Le Anh Bang; Nguyen Hoai Chau; Nguyen Thi Ly [Institute of Environmental Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Distr., Hanoi (Viet Nam); Huynh Thi Ha [Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet Road, Cau Giay Distr., Hanoi (Viet Nam); Nguyen Vu Trung [National Institute for Infectious and Tropical Diseases, 1 Ton That Tung, Dong Da Distr., Hanoi (Viet Nam)], E-mail: ttndzung@yahoo.com, E-mail: buu_nq@yahoo.com

    2009-09-01

    Nanosilver particles have been synthesized by the reverse micelle method, where AgNO{sub 3} was used as a silver ions source, NaBH{sub 4} and quercetin - as reducing agents, CTAB, SDOSS and AOT- as surfactants, while the stabilizer was Vietnamese chitosan. Studying the factors influencing the process of nanosilver particle formation, it was shown that the particle size of the nanosilver products depends on the concentration of the reaction components and their stoichiometric ratio. It was also shown that the reaction system using AOT surfactant is capable of producing nanosilver particles with smallest nanoparticles ({phi}{sub av} {approx} 5 nm) and good particle-size distribution. The study on bactericidal activity of the nanosilver products indicated that the disinfecting solution with a nanosilver concentration of 3 ppm was able to inhibit all E.coli and Coliforms, TPC and fungi at 15 ppm, while Vibrio cholerae cells were inactivated completely with 0.5 ppm of nanosilver after 30 minutes exposition.

  4. Removal of Mutagenic Organic Pollutants from Drinking Water by Combined Reverse Osmosis%反渗透组合工艺去除水中致突变有机物

    Institute of Scientific and Technical Information of China (English)

    张绍园; 姜兆春; 贾智萍; 李予江

    2001-01-01

    Using CODMn and Ames test as evaluation index,the reverse osmosisbase d process for drinking water treatment was studied on removal of mutagenic organ ic pollutants from tap water.The study results show that the activated carbon un it in the process can remove about 50% of organic pollutants,but the attenuation of tap water mutagenicity is poor.The reverse osmosis unit can remove organic p ollutants and attenuate mutagenicity simultaneously.This combined process is fea sible for providing safe potable water with good quality.%以高锰酸盐指数(CODMn)和Ames试验为评价指标,研究了以反渗透为主的组合工艺对自来水中致突变性有机物的去除效果。试验表明,组合工艺中的活性炭单元可以去除自来水中约50%的有机污染物,但对自来水的致突变性没有明显改善;反渗透膜单元能达到同时去除有机污染物和改善自来水致突变性的效果。此工艺是获得安全优质饮用水的一种可行办法。

  5. Phase diagram of soybean phosphatidylcholine-diacylglycerol-water studied by x-ray diffraction and 31P- and pulsed field gradient 1H-NMR: evidence for reversed micelles in the cubic phase.

    Science.gov (United States)

    Orädd, G; Lindblom, G; Fontell, K; Ljusberg-Wahren, H

    1995-05-01

    The phase equilibria of the system soybean phosphatidylcholine, diacylglycerol, and water has been determined using a combination of classical methods together with x-ray diffraction and NMR techniques. In particular, the extent of the phase regions of the lamellar, the reversed hexagonal, and the cubic phases have been determined. By pulsed field gradient 1H-NMR, the diffusion coefficients of all three components in a cubic phase composed of soybean phosphatidylcholine, diacylglycerol, and heavy water have been determined at 25 and 59 degrees C and also for the corresponding cubic phase composed of the chemically more well defined synthetic components 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-dioleoylglycerol (DOG), and heavy water. The extension of the phase region of the cubic phase did not seem to change appreciably for the two ternary systems studied. The translational diffusion coefficient of DOPC in this cubic phase is more than an order of magnitude smaller (3 x 10(-13) m2 s-1, 59 degrees C) than the lateral diffusion coefficient of DOPC in an oriented lipid bilayer (5 x 10(-12) m2 s-1, 35 degrees C), whereas the diffusion coefficients of water and DOG were found to be about two orders of magnitude larger than DOPC at 59 degrees C. It is concluded that the cubic phase is built built up of closed reversed micelles in accordance with the suggestion from previous x-ray diffraction studies. PMID:7612827

  6. Reversible arithmetic logic unit

    OpenAIRE

    zhou, Rigui; Shi, Yang; Zhang, Manqun

    2011-01-01

    Quantum computer requires quantum arithmetic. The sophisticated design of a reversible arithmetic logic unit (reversible ALU) for quantum arithmetic has been investigated in this letter. We provide explicit construction of reversible ALU effecting basic arithmetic operations. By provided the corresponding control unit, the proposed reversible ALU can combine the classical arithmetic and logic operation in a reversible integrated system. This letter provides actual evidence to prove the possib...

  7. Combining AOT, Angstrom Exponent and PM concentration data, with PSCF model, to distinguish fine and coarse aerosol intrusions in Southern France

    Science.gov (United States)

    Dimitriou, Konstantinos; Kassomenos, Pavlos

    2016-05-01

    In this paper, a cluster analysis of backward air mass trajectories, arriving in Avignon (Southern France), was combined with a Potential Source Contribution Function (PSCF) model on a 0.5° × 0.5° resolution grid, in order to indicate possible aerosol intrusions. A strict triple criterion was constructed from Aerosol Optical Thickness (AOT), Angstrom Exponent (AE), and PM (PM10 and PM2.5) concentration measurements, aiming to distinguish more effectively Episodes of Fine, Coarse and Overall Aerosols (FAE, CAE and OAE respectively). Large fractions of FAE (60.0%) and CAE (40.6%) were strongly attributed to the prevalence of Eastern and South-Southwest (S-SW) airflows respectively, whereas these distinct trajectory clusters also gathered large fractions of OAE (90.2% cumulatively). According to PSCF results, FAE events were strongly associated with the influence of air masses traveling over North Italy and Southern Germany, hence the impact of urban and industrial combustion was emerged. Main sources of coarse aerosols were principally isolated over the Mediterranean, thus the import of sea spray and dust from the Sahara desert is presumed. Satellite AOT observations were used for a more detailed identification of an intense 5-day intrusion of coarse aerosols. Short range slow moving air mass trajectories, were proven to be a clear marker of atmospheric stagnation, based on a wind speed analysis, triggering the accumulation of locally emitted anthropogenic aerosols (mainly PM2.5) and lack of city ventilation.

  8. Observation on Formation of Fresh Martensite from the Reversed Austenite During Water-Quenching Process in Fe-0.2C-5Mn Steel

    Science.gov (United States)

    Zhao, Chuan; Zhang, Chi; Cao, Wen-Quan; Yang, Zhi-Gang; Weng, Yu-Qing

    2015-09-01

    Phase transformation behavior during intercritical annealing in Fe-0.2C-5Mn was studied. Austenite lath formed and transformed at martensite lath during annealing. XRD revealed that retained austenite amount did not always increase with time. TEM result may firstly demonstrate that reversed austenite partly changed into fresh martensite during quenching while the remained part was retained as retained austenite. The final structure consisted of ferrite, retained austenite and fresh martensite. Simulation was done by DICTRA to support TEM result.

  9. Operation of waste water recycling system in reverse osmosis and ultra-filtration and its improvement%超滤反渗透污水回用系统的运行及改进

    Institute of Scientific and Technical Information of China (English)

    孙柏岩; 李晓巍; 孔剑锋; 隗华

    2012-01-01

      After four years operation of the water recycling system with ultra filtration and reverse osmosis in Gold East Paper, scale formation and dirt blockage occurred in reverse osmosis because of higher alkalinity, conductivity and water hardness. The composite membrane treatment project was adopted to reduce the running cost and fresh water consumption, eliminate the hidden danger.%  金东纸业超滤(UF)和反渗透(RO)污水处理回用系统在运行约四年后,由于反渗透进水水质存在波动,碱度、电导率和硬度常常偏高,导致反渗透系统非常容易结垢和污堵。采用综合膜处理方案,结合应用3D TRASAR膜自动化技术后,污水回用系统总运行费用(TCO)明显下降,减少了清水用量,从根本上消除了系统运行的隐患。

  10. Reverse osmosis application studies

    International Nuclear Information System (INIS)

    To assess the feasibility of applying reverse osmosis (RO) and ultrafiltration (UF) for effective treatment of process and waste streams from operations at Ontario Hydro's thermal and nuclear stations, an extensive literature survey has been carried out. It is concluded that RO is not at present economic for pretreatment of Great Lakes water prior to ion exchange demineralization for boiler makeup. Using both conventional and novel commercial membrane modules, RO pilot studies are recommended for treatment of boiler cleaning wastes, fly ash leachates, and flue gas desulphurization scrubber discharges for removal of heavy metals. Volume reduction and decontamination of nuclear station low-level active liquid waste streams by RO/UF also appear promising. Research programmes are proposed

  11. Water

    Science.gov (United States)

    ... www.girlshealth.gov/ Home Nutrition Nutrition basics Water Water Did you know that water makes up more ... to drink more water Other drinks How much water do you need? top Water is very important, ...

  12. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... you can use for reverse shoulder replacement. The standard delto-pectoral approach, or the superior approach, which ... that are different between a reverse and a standard total is, first of all, we don't ...

  13. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... the height perfectly to get anatomic head tuberosity relationships. If you're doing a reverse for a ... less limited with the superior reverse versus the traditional. And I assume the question means the approach: ...

  14. Water in oil microemulsions containing NaCl for transdermal delivery of fluorouracil%含电解质的W/O型微乳作为氟尿嘧啶透皮给药载体的研究

    Institute of Scientific and Technical Information of China (English)

    肖衍宇; 刘芳; 陈志鹏; 平其能

    2011-01-01

    This study is to prepare the W/O microemulsion containing NaC1 and fluorouracil (5-Fu) as a model drug to investigate the transdermal characteristics and skin irritation of the microemulsion in vitro. Isopropylmyristate (IPM) acting as oil phase, Aerosol-OT (AOT) as surfactant, Tween 85 as cosurfactant, NaC1 solution was added dropwise to the oil phase to prepare W/O microemulsion at room temperature using magnetic stirring, and then 5-Fu powder was added. According to the area of microemulsion based on the pseudo-tertiary phase diagrams, the optimum formulation was screened initially. And the permeation flux of fluorouracil across excised mice skin was determined in vitro using Franz: diffusion cells to study the influence of the amount of water and the drug loading capacity and optimize the formulation further. Refer to 5-Fu cream, the irritation of microemulsion on the rat skin was studied. The optimum formulation was composed of 0.7% (w/v) 5-Fu, 50% NaC1 solution (0.05 mol·L-1), 20% mix-surfactant (AOT/Tween 85, Km = 2) and 29.3% oil (IPM). The cumulative amount of fluorouracil permeated in 12 h was (2 013.4± 41.6) μg·cm-2, 20.23 folds and 10.38 folds more than 0.7% fluorouracil aqueous solution and 2.5% (w/w) fluorouracil cream, respectively. Microemulsion exhibited some irritation, but could be reversed after drug withdrawal. The addition of NaC1 significantly increased the content of water and the drug loading in microemulsion systems. The NaC1/AOT-Tween 85/IPM microemulsion system promoted the permeation of fluorouracil greatly, which may be a promising vehicle for the transdermal delivery of fluorouracil and other hydrophilic drug.%通过电解质氯化钠(NaCl)的加入,制备含水量高、载药量高且透过能力强的氟尿嘧啶(5-Fu)W/O型微乳,并研究其体外透皮特性及皮肤刺激性.以肉豆蔻酸异丙酯(IPM)为油相,磺化琥珀酸二辛酯钠(AOT)为表面活性剂,Tween 85为助表面活性剂,在室温下采用

  15. Reverse cholesterol transport revisited

    Institute of Scientific and Technical Information of China (English)

    Astrid; E; van; der; Velde

    2010-01-01

    Reverse cholesterol transport was originally described as the high-density lipoprotein-mediated cholesterol flux from the periphery via the hepatobiliary tract to the intestinal lumen, leading to fecal excretion. Since the introduction of reverse cholesterol transport in the 1970s, this pathway has been intensively investigated. In this topic highlight, the classical reverse cholesterol transport concepts are discussed and the subject reverse cholesterol transport is revisited.

  16. 同程布置冷水系统管网水力特性计算机分析%Computer calculation method of hydraulic characteristics of reversed return chilled water system

    Institute of Scientific and Technical Information of China (English)

    刘雪峰; 刘金平; 陈星龙; 陆继东

    2012-01-01

    以同程布置的冷水系统管网为研究对象,在充分考虑末端支路温度调节阀调节特性的基础上,建立了管网水力计算数学模型,提出了虚拟流量的计算机逻辑算法.以10个AHU支路的同程式管网为例,在所有末端支路水力可调、部分AHU关闭及部分AHU调节失灵3种情况下,分别计算了不同供回水压差下各支路温度调节阀的开度和实际流量,计算结果符合同程式管网的固有特性.%Taking a reverse-return chilled water system as the research object, based on full consideration of the regulating characteristics of temperature regulating valves in terminal branches, establishes a mathematical model of pipe network hydraulic characteristics, and puts forward a computer logic algorithm with virtual flow. Taking a reverse-return pipe network with ten AHU branches as the example, calculates the opening of temperature regulating valves and actual flow in branches respectively in the condition of different supply-return water pressure differences in three kinds of operating conditions of pipe network including all terminal branches being hydraulic adjustable, part AHU closing and part AHU being out of adjustment. The calculation results are in accord with the natural characteristics of reversed return pipe network.

  17. RESEARCH ON REVERSE OSMOSIS TREATMENT OF THE RECYCLE OF THE CONDENSATE FROM CANE MILLS TO THE BOILER SUPPLY WATER%反渗透处理糖厂二效汽凝水回用锅炉的研究

    Institute of Scientific and Technical Information of China (English)

    钮德明; 郝媛媛; 李耀熙

    2009-01-01

    The important measure to reduce energy consumption and discharge in cane mills is to use the condensate of the second effect evaporator to replace raw water as the boiler supply water. But the boilers are not used efficiently and securely when the sugar content of the condensate is too high. The condensate of the second effect evaporator has been purified carefully by using one stage reverse osmosis equipment. The results show that after the treatment, the desalination rate of the reverse osmosis system is stabilized about 87.82 % , and the effluent water quality has completely reached standards of the medium pressure boiler supply water. It is suggested that the new process of the condensate purification should be used in cane mills with medium pressure boilers.%糖厂以二效汽凝水取代原水回用锅炉是"节能减排"的重要措施,但含糖量过高的二效汽凝水回用锅炉后,将影响锅炉高效、安全使用.故此采用一级反渗透装置对二效汽凝水进行除糖净化处理.实验结果表明:反渗透系统的脱盐率能够稳定在87.82%左右,出水水质完全达到中压锅炉补充给水水质标准.建议拥有中压锅炉的糖厂采用糖厂锅炉补充给水除糖净化新工艺.

  18. APPLICATION OF REVERSE OSMOSIS TECHNOLOGY TO THE DESALINATION PROCESS IN SUPPLEMENT WATER FOR SUBMERGED ARC FURNACE%反渗透技术在矿热炉补充水除盐工艺的应用

    Institute of Scientific and Technical Information of China (English)

    吴秋勤; 曾世林; 王正

    2015-01-01

    This paper introduced the application of reverse osmosis technology to the desalination process in supplement water for submerged arc furnace. It tested the effects of original water suspended matter concentration,hardness and static pressure difference both sides of RO membrane on system operation, water yield and desalination rate. The result shows that original water suspended matter has great effects on system water production and original water hardness has less ef-fect on RO water production. It is beneficial to enhance desalination to decrease the static pressure difference both sides of RO membrane. It plays a key role in normal operation of system to increase combined deep pretreatment, decrease the original water concentration and strengthen germicide and algicide in pretreatment stage.%介绍了反渗透技术在矿热炉补充水除盐工艺中的应用,并进行了原水悬浮物浓度、硬度和RO膜两侧静压差对系统运行状况、产水量和除盐率影响的测试.结果表明,原水悬浮物对系统产水量有严重影响;原水硬度对RO产水量影响相对较小;RO膜两侧静差降低,有利于提高除盐率.增加组合深度预处理工序,降低原水的悬浮物浓度,强化预处理阶段杀菌灭藻,对除盐系统设备正常运行起关键作用.

  19. Process optimization for reverse micellar extraction of stem bromelain with a focus on back extraction.

    Science.gov (United States)

    Dhaneshwar, Amrut D; Chaurasiya, Ram Saran; Hebbar, H Umesh

    2014-01-01

    In the current study, reverse micellar extraction (RME) for the purification of stem bromelain was successfully achieved using the sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/isooctane system. A maximum forward extraction efficiency of 58.0% was obtained at 100 mM AOT concentration, aqueous phase pH of 8.0 and 0.2 M NaCl. Back extraction studies on altering stripping phase pH and KCl concentration, addition of counter-ion and iso-propyl alcohol (IPA) and mechanical agitation with glass beads indicated that IPA addition and agitation with glass beads have significant effects on extraction efficiency. The protein extraction was higher (51.9%) in case of the IPA (10% v/v) added system during back extraction as compared to a cetyltrimethylammonium bromide (100 mM) added system (9.42%). The central composite design technique was used to optimize the back extraction conditions further. Concentration of IPA, amount of glass beads, mixing time, and agitation speed (in rpm) were the variables selected. IPA concentration of 8.5% (v/v), glass bead concentration of 0.6 (w/v), and mixing time of 45 min at 400 rpm resulted in higher back extraction efficiency of 45.6% and activity recovery of 88.8% with purification of 3.04-fold. The study indicated that mechanical agitation using glass beads could be used for destabilizing the reverse micelles and release of bromelain back into the fresh aqueous phase. PMID:24616421

  20. Water Quality Analysis of Reverse Osmosis Desalination Brine%反渗透海水淡化后浓海水的水质特点研究

    Institute of Scientific and Technical Information of China (English)

    胡海燕; 周琳

    2012-01-01

      Seawater desalination develops fast as a significant method to solve the global water resource crisis. But there are rare report about the quality of concentrated sea water. In this paper,many parameters of seawater desalination water and original seawater are analyzed. the data we got may be something useful for the water environment management and scientific study.%  作为水资源的开源增量技术,海水淡化已经成为解决全球水资源危机的重要途径。通过对浓海水的水质分析,分析了海水淡化水质状况和存在的主要问题,为水源地的水环境管理和规划提供重要科学依据。

  1. States of water located in the continuous organic phase of 1-butyl-3-methylimidazolium tetrafluoroborate/Triton X-100/triethylamine reverse microemulsions.

    Science.gov (United States)

    Li, Na; Cao, Quan; Gao, Yanan; Zhang, Jin; Zheng, Liqiang; Bai, Xiangtao; Dong, Bin; Li, Zhen; Zhao, Mingwei; Yu, Li

    2007-10-22

    We demonstrate a novel ionic liquid (IL) microemulsion, consisting of 1-butyl-3-methylimidazolium tetrafluoroborate (bmimBF4) and nonionic surfactant Triton X-100 prepared in triethylamine which is used either as an organic solvent or a Lewis base. The effects of small amounts of added water on the microstructure of the IL microemulsion are investigated by various techniques. UV/Vis spectroscopic analysis and FTIR spectra indicate that these water molecules are not solubilized into the IL pools of the microemulsions. 1H NMR spectra further show that the added water binds with triethylamine to form a surrounding OH- base environment. Some of OH- ions enter the palisade layers of the IL microemulsions and a continuous base interface is created. The unique solubilization behavior of water reveals that it is possible to use the triethylamine microemulsions as a template to prepare metal hydroxides as well as metal oxides in the microemulsions, which is not possible when using traditional microemulsions. PMID:17886245

  2. Boiler feedwater treatment using reverse osmosis at Suncor OSG

    International Nuclear Information System (INIS)

    The installation of a new 1000 cu m/hr reverse osmosis water treatment system for boiler feedwater at a Suncor plant was discussed. The selection process began in 1993 when Suncor identified a need to increase its boiler feedwater capacity. The company reviewed many options available to increase the treated water capacity. These included: contracting the supply of treated water, adding additional capacity, replacing the entire plant, reverse osmosis, and demineralization. The eventual decision was to build a new 1000 cu m/hr reverse osmosis water treatment plant with the following key components: a Degremont Infilco Ultra Pulsator Clarifier and a Glegg Water Conditioning multimedia filter, Amberpack softeners and reverse osmosis arrays. The reverse osmosis plant was environmentally favourable over an equivalent demineralization plant. A technical comparison was provided between demineralization and reverse osmosis. The system has proven to be successful and economical in meeting the plants needs. 5 figs

  3. Offline solid-phase extraction for preconcentration of pharmaceuticals and personal care products in environmental water and their simultaneous determination using the reversed phase high-performance liquid chromatography method.

    Science.gov (United States)

    G Archana; Dhodapkar, Rita; Kumar, Anupama

    2016-09-01

    The present study reports a precise and simple offline solid-phase extraction (SPE) coupled with reversed-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous determination of five representative and commonly present pharmaceuticals and personal care products (PPCPs), a new class of emerging pollutants in the aquatic environment. The target list of analytes including ciprofloxacin, acetaminophen, caffeine benzophenone and irgasan were separated by a simple HPLC method. The column used was a reversed-phase C18 column, and the mobile phase was 1 % acetic acid and methanol (20:80 v/v) under isocratic conditions, at a flow rate of 1 mL min(-1). The analytes were separated and detected within 15 min using the photodiode array detector (PDA). The linearity of the calibration curves were obtained with correlation coefficients 0.98-0.99.The limit of detection (LOD), limit of quantification (LOQ), precision, accuracy and ruggedness demonstrated the reproducibility, specificity and sensitivity of the developed method. Prior to the analysis, the SPE was performed using a C18 cartridge to preconcentrate the targeted analytes from the environmental water samples. The developed method was applied to evaluate and fingerprint PPCPs in sewage collected from a residential engineering college campus, polluted water bodies such as Nag river and Pili river and the influent and effluent samples from a sewage treatment plant (STP) situated at Nagpur city, in the peak summer season. This method is useful for estimation of pollutants present in microquantities in the surface water bodies and treated sewage as compared to nanolevel pollutants detected by mass spectrometry (MS) detectors. PMID:27502523

  4. STUDY ON REMOVAL OF SULFATE FROM CIRCULATING WATER OF MINERAL PROCESSING BY REVERSE OSMOSIS%反渗透脱除选矿循环水中硫酸根的研究

    Institute of Scientific and Technical Information of China (English)

    宋敏娟; 熊守安; 张荣; 刘曙; 刘红

    2013-01-01

    Reverse osmosis was used for the treatment of sulfate from synthetic wastewater, and effects of operating rime, operating pressure as well as SO42-concentration of wastewater on separating performance of sulfete and membrane permeate flux were investigated.The actual wastewater was treated under optimal technical conditions.The results showed that under the different experimental conditions, the removal rate of sulfate from synthetic wastewater by reverse osmosis membrane was all steadily above 95%, but permeate flux changed greatly.When the operating pressure was 0.4 MPa and water temperature was 25 ℃, the removal rate of sulfate from circulating water of mineral processing was 98%.The concentration of sulfate and chloride, as well as the chroma and turbidity in the effluent all achieved the standard of GB/T 19923-2005, which met the requirements of water reuse.%采用反渗透处理废水中的SO42-,考察了运行时间、操作压力、废水中SO42-含量等因素对SO4-分离性能及膜产水量的影响,并于最佳工艺条件下处理选矿循环水.结果表明,在不同试验条件下,反渗透膜对模拟废水中SO42-的去除率均稳定在95%以上,但产水量变化较大;在操作压力0.4 MPa、温度25℃的条件下,选矿循环水中SO42-的去除率高达98%,出水中SO42-、Cl-含量及色度、浊度均达到GB/T 19923-2005标准,满足回用要求.

  5. On-line concentration of neutral analytes for micellar electrokinetic chromatography. VI. Stacking using reverse migrating micelles and a water plug.

    Science.gov (United States)

    Quirino, J P; Otsuka, K; Terabe, S

    1998-08-28

    Utility of a second enhanced field zone (water zone) is investigated for the on-line concentration of neutral analytes in micellar electrokinetic chromatography. Micellar solutions of sodium dodecyl sulfate prepared in acidic phosphate buffers are used as separation and sample solutions. Prior to long hydrodynamic injection of samples prepared in a low conductivity matrix, a long water plug is hydrodynamically injected to provide a second enhanced field zone. Practical and some fundamental considerations are presented. The technique is selective towards hydrophobic analytes. Notable detector response improvements (>100-fold) for several analytes are observed experimentally. PMID:9746232

  6. A model for triple helix formation on human telomerase reverse transcriptase (hTERT) promoter and stabilization by specific interactions with the water soluble perylene derivative, DAPER.

    Science.gov (United States)

    Rossetti, Luigi; D'Isa, Giuliana; Mauriello, Clementina; Varra, Michela; De Santis, Pasquale; Mayol, Luciano; Savino, Maria

    2007-08-01

    The promoter of human telomerase reverse transcriptase (hTERT) gene, in the region from -1000 to +1, contains two homopurine-homopyrimidine sequences (-835/-814 and -108/-90), that can be considered as potential targets to triple helix forming oligonucleotides (TFOs) for applying antigene strategy. We have chosen the sequence (-108/-90) on the basis of its unfavorable chromatin organization, evaluated by theoretical nucleosome positioning and nuclease hypersensitive sites mapping. On this sequence, anti-parallel triplex with satisfactory thermodynamic stability is formed by two TFOs, having different lengths. Triplex stability is significantly increased by specific interactions with the perylene derivative N,N'-bis[3,3'-(dimethylamino) propylamine]-3,4,9,10-perylenetetracarboxylic diimide (DAPER). Since DAPER is a symmetric molecule, the induced Circular Dichroism (CD) spectra in the range 400-600 nm allows us to obtain information on drug binding to triplex and duplex DNA. The drug-induced ellipticity is significantly higher in the case of triplex with respect to duplex and, surprisingly, it increases at decreasing of DNA. A model is proposed where self-stacked DAPER binds to triplex or to duplex narrow grooves. PMID:17560709

  7. Design of Reversible Counter

    OpenAIRE

    Md. Selim Al Mamun; B. K. Karmaker

    2014-01-01

    This article presents a research work on the design and synthesis of sequential circuits and flip-flops that are available in digital arena; and describes a new synthesis design of reversible counter that is optimized in terms of quantum cost, delay and garbage outputs compared to the existing designs. We proposed a new model of reversible T flip-flop in designing reversible counter.

  8. "Reverse" Nested Lottery Contests

    OpenAIRE

    Qiang Fu; Jingfeng Lu; Zhewei Wang

    2013-01-01

    This paper proposes a multi-prize "reverse" nested lottery contest model, which can be viewed as the "mirror image" of the conventional nested lottery contest of Clark and Riis (1996a). The reverse-lottery contest model determines winners by selecting losers based on contestants' one-shot effort through a hypothetical sequence of lotteries. We provide a microfoundation for the reverse-lottery contest from a perspective of (simultaneous) noisy performance ranking and establish that the model i...

  9. Posterior Reversible Encephalopathy Syndrome

    OpenAIRE

    J Gordon Millichap

    2013-01-01

    Investigators at Children's Hospital of Montefiore, Albert Einstein College of Medicine, NY, determined the incidence of posterior reversible encephalopathy syndrome (PRES) in a pediatric critical care unit.

  10. Relevant factors for membrane fouling in brackish water reverse osmosis desalination%苦咸水反渗透淡化中影响膜面的污染因素∗

    Institute of Scientific and Technical Information of China (English)

    宋跃飞; 李铁梅; 周建国; 苏保卫; 高从堦

    2015-01-01

    Fouling phenomenon, type and degree in brackish water reverse osmosis ( BWRO ) desalination are significantly different from seawater reverse osmosis ( SWRO) process, due to the complex components of brackish water in different regions and the higher concentrate factor ( CF ) value in the majority of BWRO processes. Currently, membrane fouling as one of the bottlenecks for the large⁃scale BWRO application, has attracted in creasing attentions. In this review, overseas and domestic research progresses in application factors influencing the fouling on membrane surface in BWRO desalination were summarized in detail. The fouling components, fouling potential and quality indicators in water resources, and the physical properties influencing membrane fouling were introduced respectively. Two types of pretreatment methods including conventional and membrane technology were analysed, and the advantage of consistently high quality independent of influent associated with for membrane pretreatment was pointed out. In addition, the problems and suggestions for the current research status were proposed.%由于苦咸水的化学组成和浓度分布在不同地区有着显著的差异,以及淡化工艺中普遍较高的浓缩因子( concentrate factor, CF)值(在4—10之间),苦咸水反渗透( brackish water reverse osmosis, BWRO)淡化过程中的膜污染现象、类型和程度较海水反渗透( seawater reverse osmosis, SWRO)淡化过程有明显的不同。目前,膜污染已成为BWRO大规模应用于苦咸水淡化领域的瓶颈之一,如何解决这一问题成为该领域的研究热点。本文详细综述了国内外BWRO淡化过程中影响膜面污染因素的应用研究进展,重点介绍了进水来源污染成分及污染倾向、进水水质优劣指标和进水物性对膜面污染的影响;按照分离技术的不同,分类讨论了常规预处理和膜法预处理工艺,指出后者不易受进水水质变化的

  11. 煤化工反渗透浓盐水处理和回用的探讨%On the Coal Chemical iIndustry of Reverse Osmosis Concentrated Water Treatment and Reuse of

    Institute of Scientific and Technical Information of China (English)

    陈海斌

    2012-01-01

      This paper explores how to study for coal chemical reverse osmosis concentrated brine was effective for treatment and reuse of wastewater, further improve the comprehensive reuse rate, greatly reduce discharge of wastewater and waste water discharged together with the chemical oxygen demand (COD)aggregates, which for the coal chemical industry and long-term development has important sense.%  研究探讨如何针对煤化工反渗透浓盐水进行有效处理回用,进一步提高废水的综合回用率,大幅度减少废水排放量以及随废水一同排放的化学耗氧量(COD)总量,这对于煤化工行业的长远发展具有重要意义。

  12. Treatment of reverse osmosis concentrated water by ClO2 three-phase catalytic oxidation%二氧化氯三相催化氧化法处理反渗透浓水试验研究

    Institute of Scientific and Technical Information of China (English)

    李常青; 杨岳; 刘发强; 刘光利; 江岩; 巫树峰

    2011-01-01

    In view of the fact that the reverse osmosis concentrated water from wastewater reuse device of Petrochemical Corporation is hard to be biodegraded for its high CODcr. And salt concentration, C1O2 three-phase catalytic oxidation process was used to treat the said kind of wastewater. The results of the test showed that: with the aid of catalyst under the condition that the optimal active components of the catalyst was CuO/NiO/La2O3/ CeO2, the optimal mole ratio of these metal oxides was 3 : 1 : 2 : 2; when the input flow of the reverse osmosis concentrated water was 50 L/h, the mass concentration of CODcr was 95 - 230 mg/L, the optimal pH value was 6.0 - 7.0, the C1O2 dosage was 90 - 120 mg/L, the air input was 0.6 - 0.9 mVh, the reaction time was 30 min, the removal rate of CODcr. Reached above 85%, the treated reverse osmosis concentrated water quality was stable and could meet the discharge standard. Thus it could draw a conclusion that, C1O2 three-phase catalytic oxidation is a feasible and competitive technology for reverse osmosis concentrated water treatment.%针对炼化企业污水回用装置反渗透单元浓水CODCr浓度高、难生化降解以及含盐量高等特点,利用ClO2三相催化氧化法处理反渗透浓水.试验结果表明:在催化剂存在条件下,催化剂的最佳活性组成为CuO/NiO/La2O3/CeO2,活性组分的最佳物质的量之比为3∶1∶2∶2;在反渗透浓水进水量为50 L/h、进水CODCr的质量浓度为95 ~ 230 mg/L时,最佳反应pH值为6.0~7.0,ClO2投加量为90~120 mg/L,空气进气量为0.6 ~ 0.9 m3/h,反应时间为30 min,CODCr去除率大于85%,处理后的反渗透浓水可以实现稳定达标排放.C1O2三相催化氧化处理反渗透浓水是一项具有良好实用性和很强竞争力的处理方法.

  13. Chemical reactions in reverse micelle systems

    Science.gov (United States)

    Matson, Dean W.; Fulton, John L.; Smith, Richard D.; Consani, Keith A.

    1993-08-24

    This invention is directed to conducting chemical reactions in reverse micelle or microemulsion systems comprising a substantially discontinuous phase including a polar fluid, typically an aqueous fluid, and a microemulsion promoter, typically a surfactant, for facilitating the formation of reverse micelles in the system. The system further includes a substantially continuous phase including a non-polar or low-polarity fluid material which is a gas under standard temperature and pressure and has a critical density, and which is generally a water-insoluble fluid in a near critical or supercritical state. Thus, the microemulsion system is maintained at a pressure and temperature such that the density of the non-polar or low-polarity fluid exceeds the critical density thereof. The method of carrying out chemical reactions generally comprises forming a first reverse micelle system including an aqueous fluid including reverse micelles in a water-insoluble fluid in the supercritical state. Then, a first reactant is introduced into the first reverse micelle system, and a chemical reaction is carried out with the first reactant to form a reaction product. In general, the first reactant can be incorporated into, and the product formed in, the reverse micelles. A second reactant can also be incorporated in the first reverse micelle system which is capable of reacting with the first reactant to form a product.

  14. 超滤-反渗透双膜法用于中水回用的中试研究%Pilot test on the reclaimed water by a ultrafiltration/reverse osmosis process

    Institute of Scientific and Technical Information of China (English)

    李倩; 汪后港; 于萍; 罗运柏

    2013-01-01

    To reduce their fresh water consumption,Wuhan Iron and Steel (Group) Corporation has attempted to reclaim its mixed treated wastewater.Due to the high conductivity,a integrated ultrafiltration/reverse osmosis (UF/RO) system was built.The influence of effluent water quality on the UF membrane flux,trans-membrane pressure and cross-flow velocity was investigated.The backwashing period was determined.The pollution situation of UF membrane was analyzed.After advanced treatment by the UF/RO process,the conductivity of producing water was reduced to 20 μS/cm and the average desalinization ratio reached to 96.9 %.%针对钢铁企业污水处理站出水回用时存在含盐量高的问题,采用超滤-反渗透双膜法对出水进行深度处理.试验考察了武钢污水处理站出水水质对超滤膜通量、跨膜压差和膜面流速的影响,确定了超滤反洗周期,分析了超滤膜的污染情况,经双膜法深度处理后的产水电导率保持在20 μ S/cm以下,平均除盐率为96.9%.

  15. 基于MCGS和PLC的反渗透水处理监控系统设计%Design of reverse osmosis water treatment monitoring system base on MCGS and PLC

    Institute of Scientific and Technical Information of China (English)

    徐惠芳; 曹嘉; 伍星

    2011-01-01

    For the purpose of enhancing system reliability, improving the control precision and the passing rate of water treatment and reducing the burden on operators, a reverse osmosis water treatment monitoring system was designed based on MCCS and PLC, combining the practice in certain plant. Automatic control, centralized data management, fault alarm, and many other functions were achieved; Graphical interface displays the whole process and operates easily. It works reliably in water plant and the passing rate substantially increases, so it has a high practical value.%为了增强系统运行的可靠性,提高控制精度和水质处理合格率,同时减轻操作负担,结合某厂实际,设计了基于MCGS组态软件和可编程控制器(PLC)的反渗透水处理监控系统.此系统实现了自动控制、数据集中管理、故障报警等多方面功能,图形化的人机界面显示了设备运行全过程,操作简明快捷.在水厂的实际运行中安全可靠,出水合格率大幅提高,具有很高的实用价值.

  16. Lidar Observations of Low-level Wind Reversals over the Gulf of Lion and Characterization of Their Impact on the Water Vapour Variability

    OpenAIRE

    Di Girolamo Paolo; Flamant Cyrille; Cacciani Marco; Summa Donato; Stelitano Dario; Mancini Ignazio; Richard Evelyne; Ducrocq Véronique; Nuret Mathieu; Said Frédérique

    2016-01-01

    International audience Water vapour measurements from a ground-based Raman lidar and an airborne differential absorption lidar, complemented by high resolution numerical simulations from two mesoscale models (Arome-WMED and MESO-NH), are considered to investigate transition events from Mistral/Tramontane to southerly marine flow taking place over the Gulf of Lion in Southern France in the time frame September-October 2012, during the Hydrological Cycle in the Mediterranean Experiment (HyMe...

  17. An alternative hybrid concept combining seawater desalination, solar energy and reverse electrodialysis for a sustainable production of sweet water and electrical energy

    OpenAIRE

    Brauns, E.

    2010-01-01

    Fresh water and oil/gas based energy will become scarce since their actual (increase in) consumption rate is definitely unsustainable, when considering their restricted world reserves. Moreover, the large scale burning of such fuels for the production of electrical energy or in industry/transport results in a significant rising of the carbon dioxide concentration in the atmosphere and therefore a rising of global temperatures. Research and development regarding alternative energy sources such...

  18. 反渗透深度处理维生素C凝结水的中试研究%Pilot test on reverse osmosis to treat condensed water containing vitamin C

    Institute of Scientific and Technical Information of China (English)

    肖入峰; 刘景洋; 张建强; 孙晓明; 陈雪

    2012-01-01

    针对沈阳某药厂维生素C生产工艺中凝结水产量大、处理成本高和杂质复杂等问题,提出了采用反渗透技术对工艺凝结水进行处理.通过建立中试规模膜装置,在间歇试验和连续试验的基础上,分析了膜通量、压力、运行时间、电导率、总有机碳(TOC)等指标关系,研究了运行临界通量、清洗方式等工艺条件.反渗透系统处理效果明显,脱盐率和TOC去除率分别维持在99.9%和99%以上,该工艺切实可行.%Aiming at the problems in vitamin C production process in some pharmacy plant in Shenyang, such as large condensed water quantity, high treatment cost, and complicated impurities, the reverse osmosis process was suggested to treat the production condensed water in this paper. Based on the bench experiments and continuous experiments, this paper analyzed the relationship between the indexes of membrane flux, pressure, operation time, electrical conductivity, total organic carbon (TOC) through the pilot scale membrane facility, meanwhile, some process parameters, including the critical operation flux and cleaning method, were also studied. The reverse osmosis showed good performance in study. The desalination rate and TOC removal rate were above 9 9.9% and 99 % , respectively, which indicated that this process was applicable.

  19. Reversible cerebral vasoconstriction syndrome

    Directory of Open Access Journals (Sweden)

    Saini Monica

    2009-01-01

    Full Text Available Reversible cerebral vasoconstriction syndromes (RCVS are a group of disorders that have in common an acute presentation with headache, reversible vasoconstriction of cerebral arteries, with or without neurological signs and symptoms. In contrast to primary central nervous system vasculitis, they have a relatively benign course. We describe here a patient who was diagnosed with RCVS.

  20. Quantum reverse hypercontractivity

    Energy Technology Data Exchange (ETDEWEB)

    Cubitt, Toby [Department of Computer Science, University College London, London, United Kingdom and Centre for Quantum Information and Foundations, DAMTP, University of Cambridge, Cambridge (United Kingdom); Kastoryano, Michael [NBIA, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen (Denmark); Montanaro, Ashley [School of Mathematics, University of Bristol, Bristol (United Kingdom); Temme, Kristan [Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, California 91125 (United States)

    2015-10-15

    We develop reverse versions of hypercontractive inequalities for quantum channels. By generalizing classical techniques, we prove a reverse hypercontractive inequality for tensor products of qubit depolarizing channels. We apply this to obtain a rapid mixing result for depolarizing noise applied to large subspaces and to prove bounds on a quantum generalization of non-interactive correlation distillation.

  1. Hydrogen-bond effects induced by alcohol on the structure and dynamics of ionic reverse micelles

    Science.gov (United States)

    Bardez, E.; Giordano, R.; Jannelli, M. P.; Migliardo, P.; Wanderlingh, U.

    1996-09-01

    In this work we report how the structure of Zn(AOT) 2/H 2O/d-cyclohexane microemulsions is affected by the presence of alcohol (normal pentanol) molecules as cosurfactant. The systems are investigated by small-angle neutron scattering (SANS) and by Fourier transform IR (FTIR) spectroscopy. The SANS technique allows the study of the evolution of the size, the shape and the possible correlation length of concentration fluctuations as a function of water and alcohol content. Moreover FTIR spectra, in the OH stretching region, is quite sensitive to the structural changes of the water, induced by the polarization effects of the polar heads of the micelle surface and the positive counterions and by the presence of the alcohol.

  2. Vibrational dynamics of ice in reverse micelles.

    Science.gov (United States)

    Dokter, Adriaan M; Petersen, Christian; Woutersen, Sander; Bakker, Huib J

    2008-01-28

    The ultrafast vibrational dynamics of HDO:D(2)O ice at 180 K in anionic reverse micelles is studied by midinfrared femtosecond pump-probe spectroscopy. Solutions containing reverse micelles are cooled to low temperatures by a fast-freezing procedure. The heating dynamics of the micellar solutions is studied to characterize the micellar structure. Small reverse micelles with a water content up to approximately 150 water molecules contain an amorphous form of ice that shows remarkably different vibrational dynamics compared to bulk hexagonal ice. The micellar amorphous ice has a much longer vibrational lifetime than bulk hexagonal ice and micellar liquid water. The vibrational lifetime is observed to increase linearly from 0.7 to 4 ps with the resonance frequency ranging from 3100 to 3500 cm(-1). From the pump dependence of the vibrational relaxation the homogeneous linewidth of the amorphous ice is determined (55+/-5 cm(-1)). PMID:18247971

  3. Vibrational dynamics of ice in reverse micelles

    Science.gov (United States)

    Dokter, Adriaan M.; Petersen, Christian; Woutersen, Sander; Bakker, Huib J.

    2008-01-01

    The ultrafast vibrational dynamics of HDO :D2O ice at 180K in anionic reverse micelles is studied by midinfrared femtosecond pump-probe spectroscopy. Solutions containing reverse micelles are cooled to low temperatures by a fast-freezing procedure. The heating dynamics of the micellar solutions is studied to characterize the micellar structure. Small reverse micelles with a water content up to approximately 150 water molecules contain an amorphous form of ice that shows remarkably different vibrational dynamics compared to bulk hexagonal ice. The micellar amorphous ice has a much longer vibrational lifetime than bulk hexagonal ice and micellar liquid water. The vibrational lifetime is observed to increase linearly from 0.7to4ps with the resonance frequency ranging from 3100to3500cm-1. From the pump dependence of the vibrational relaxation the homogeneous linewidth of the amorphous ice is determined (55±5cm-1).

  4. 反渗透技术用于高矿化度矿井水处理的研究%APPLICATION OF REVERSE OSMOSIS TECHNOLOGY IN THE TREATMENT OF HIGHLY MINERALIZED MINE WATER

    Institute of Scientific and Technical Information of China (English)

    杨慧敏; 何绪文; 何咏

    2009-01-01

    The reverse osmosis (RO) technology was adopted to treat mine water with high salinity,in which the removal of various ions in the mine water by the usage of CPA (Composite Polyamide) membrane were investigated. The results showed that: during the 24 d of systems operation, the treatment effect of RO process in treating the coal mine water was good, the average removal rates of various ions could reach above 98% (Ca~(2+)), above 94% (Cl~-), above 98% (SO_4~(2-)) and above 95% (Mg~(2+)) respectively, the system effluent quality is stable and the tested items of the effluent met the national drinking water standards; and the pollution characteristics of RO membrane was summarized according to the static cleaning of the polluted membrane, finally the optimal washing process was determined, that is washing the RO membrane firstly by alkali and later by acid.%采用反渗透技术对高矿化度矿井水进行处理,考察了CPA(芳香族聚酰胺)膜对矿井水中各种离子的去除效果.试验结果表明:系统运行24 d,对矿井水的处理效果显著,Ca~(2+)、Cl~-、SO_4~(2-)、Mg~(2+)各离子的平均去除率可分别达到98%、94%、98%、95%以上,系统出水水质稳定,出水达到国家饮用水标准;并根据静态清洗反渗透(RO)污染膜的分析结果,总结出反渗透膜的污染特征,最终优选出先碱洗后酸洗的膜清洗方案.

  5. ELECTRIC ADSORPTION TREATMENT STUDY ON REFINERY REVERSE OSMOSIS CONDENSED WATER DESALINATION%电吸附法处理炼化反渗透浓水脱盐研究

    Institute of Scientific and Technical Information of China (English)

    张国珍; 李娜; 武福平; 杨公博; 杨仕超

    2012-01-01

    采用电吸附法对反渗透浓水进行处理,先研究了不同盐含量、电压、流量、初始pH等因素对NaCl模拟水去除效果的影响,得出适宜参数,再分别通过单级和多级电吸附法处理反渗透浓水,分析脱盐效果.结果表明,NaCl模拟水在初始电导率为2 mS/cm时,pH为7.56、电压1.8V、体积流量10 mL/min时处理效果最优,单级脱盐率达到17.18%;反渗透浓水在初始电导率为2 mS/cm时,以pH为7.17、电压为1.8 V、体积流量为10 mL/min时处理,单级脱盐率达到15.86%,经过3级处理后脱盐率达到了46.02%.%The thesis adopted electric adsorption processing to treat the reverse osmosis condensed water, first, studying simulation solution of NaCl desalination effects on some factors such as different concentrations, voltage, flow, initial pH, and obtain the best parameters by experiment condition, then by dealing with reverse osmosis condensed water to analysis desalination effect with single stage and several stages respectively. The results showed that when the initial conductivity of the simulation solution of NaCl desalination in was 2 mS/cm, pH was 7.56, the voltage was 1.8 V, the velocity was 10 mL/min, the treatment effect achieved the best, the desalination rate reached 17.18%. When the initial conductivity of condensed water was 2 mS/cm, the pH was 7.17, the voltage was 1.8 V, the velocity was 10 mL/min, the single stage desalination rate reached 15.86%, which reached 46.02% after through three stages.

  6. Research on reverse osmosis membrane treatment technology of condensate water containing organic acid%反渗透膜处理含有机酸凝结水技术

    Institute of Scientific and Technical Information of China (English)

    李静; 刘景洋; 乔琦; 海热提; 孙晓明

    2012-01-01

    采用反渗透膜对某制药厂含甲酸、乙酸、丙酸、丁酸、戊酸、己酸、异丁酸和2-甲基丁酸的凝结水进行处理,研究了进水温度、压力和pH值对凝结水中有机酸截留效果的影响,讨论了反渗透膜对有机酸的截留机理。研究结果表明:温度为20~40℃、压力为0.5~1.5 MPa、pH值为4~10时,产水中丁酸、戊酸、己酸和2-甲基丁酸的浓度低于检测限,甲酸、乙酸、丙酸和异丁酸的截留率随着压力和pH值增加而增大,随着温度升高而降低;产水率随着压力增大、温度升高而增大,不受pH值变化影响。说明反渗透膜对有机酸的机械筛除作用及膜与有机酸之间的电荷作用对有机酸的截留具有重要影响。%This research focused on the application of reverse osmosis membrane to treat the condensate water containing formic acid,acetic acid,propionic acid,butyric acid,pentanoic acid,carproic acid,isobutyric acid and 2-methyl-butyric acid.The effects of water temperature,pressure and pH on retention rate of organic acids,as well as the retention mechanism were discussed.The results indicated the concentration of butyric acid,pentanoic acid and 2-methyl-butyric acid in producing water were below detection limit when the experimental conditions of water temperature at 20— 40 ℃,pressure at 0.5—1.5 MPa,pH at 4—10.The retention rate of formic acid,acetic acid,propionic acid and carproic acid decreased with the increase of water temperature and increased with the increase of pressure and pH.The water production rate increased when both water temperature and pressure increased.The mechanic screening of reverse osmosis membrane and the charge effect between organic acid and membrane should have important influences on the retention effect of organic acids.

  7. An Algebra of Reversible Computation

    OpenAIRE

    Wang, Yong

    2014-01-01

    We design an axiomatization for reversible computation called reversible ACP (RACP). It has four extendible modules, basic reversible processes algebra (BRPA), algebra of reversible communicating processes (ARCP), recursion and abstraction. Just like process algebra ACP in classical computing, RACP can be treated as an axiomatization foundation for reversible computation.

  8. On the construction of reversible automata for reversible languages

    OpenAIRE

    Lombardy, Sylvain

    2002-01-01

    International audience Reversible languages occur in many different domains. Although the decision for the membership of reversible languages was solved in 1992 by Pin, an effective construction of a reversible automaton for a reversible language was still unknown. We give in this paper a method to compute a reversible automaton from the minimal automaton of a reversible language. With this intention, we use the universal automaton of the language that can be obtained from the minimal auto...

  9. Reversible flowchart languages and the structured reversible program theorem

    DEFF Research Database (Denmark)

    Yokoyama, Tetsuo; Axelsen, Holger Bock; Glück, Robert

    2008-01-01

    Many irreversible computation models have reversible counterparts, but these are poorly understood at present. We introduce reversible flowcharts with an assertion operator and show that any reversible flowchart can be simulated by a structured reversible flowchart using only three control flow o...... justification for low-level machine code for reversible microprocessors as well as high-level block-structured reversible languages. We give examples for both such languages and illustrate them with a lossless encoder for permutations given by Dijkstra....

  10. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... stability and soft tissue envelope. In the early days of reverse arthroplasty, it used to be said ... often we'll drain these patients for a day to try to prevent hematoma formation, especially in ...

  11. Purchasing As Reverse Marketing

    OpenAIRE

    Blenkhorn, D L; Banting, P M

    1989-01-01

    This paper describes a new concept called reverse marketing, which is changing the conventional buyer-seller relationship and has important implications for the traditional role of the industrial marketer.

  12. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... replacement. There are two basic approaches you can use for reverse shoulder replacement. The standard delto-pectoral ... surgery or a deltoid defect because you can use the same incision and repair any deltoid defects ...

  13. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... the reverse allow patients to play tennis or sports where the arm swings backward. Our experience has ... who simply wants to be stronger or play sports better. But in terms of the patients that ...

  14. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... with an intact cuff, we would consider a traditional shoulder replacement. There are two basic approaches you ... less limited with the superior reverse versus the traditional. And I assume the question means the approach: ...

  15. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... in the United States. The indications are a patient with painful arthritis, absent rotator cuff, a less ... reverse arthroplasty is indicated for that type of patient. In a younger patient with an intact cuff, ...

  16. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... reverse shoulder arthroplasty for cuff deficient arthritis. You should be aware that I helped design the system ... the delto- pectoral approach. The three features you should watch for in this video are the things ...

  17. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... the height perfectly to get anatomic head tuberosity relationships. If you're doing a reverse for a ... able to start some gentle mobility of the body and the arm, and have better pain relief. ...

  18. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... a friction bite that if you try to work it around the corner, you can get an ... stability and soft tissue envelope. In the early days of reverse arthroplasty, it used to be said ...

  19. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... We usually lay this just at the inner table of the biceps groove next to the lesser ... is, does the reverse allow patients to play tennis or sports where the arm swings backward. Our ...

  20. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... is essentially a culture medium. So, I use antibiotic-impregnated cement when I do the reverses. I ... minimal. At our institution we keep them on antibiotics for 24 hours. And hopefully the drain output ...

  1. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... case of reverse shoulder arthroplasty for cuff deficient arthritis. You should be aware that I helped design ... in the last decade for cuff deficient shoulder arthritis in the United States. The indications are a ...

  2. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... dislocations, although it's also reported to have a higher rate of getting the components in not perfect ... about infection and other things. There is a higher rate of infection with reverse replacement, probably because ...

  3. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... here in New York to bring you a video of a recent case of reverse shoulder arthroplasty ... helped design the system that's shown in this video, so I receive royalties and therefore have a ...

  4. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... residents and do receive compensation for that, as well. Now, reverse shoulder arthroplasty is a new option ... t see the neck of the humerus as well, but on the other hand, you have a ...

  5. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... terminal range. The other thing to keep in mind is there's a fairly large dead space between ... the height perfectly to get anatomic head tuberosity relationships. If you're doing a reverse for a ...

  6. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available ... their arm up but they can't do it actively. And the reverse arthroplasty is indicated for ... those. The advantage of a superior approach is it's especially useful if you've had previous open ...

  7. Physicochemical investigation of biocompatible mixed surfactant reverse micelles: II. Dynamics of conductance percolation, energetics of droplet clustering, effect of additives and dynamic light scattering studies

    International Nuclear Information System (INIS)

    Graphical abstract: Tp/°C: Threshold temperature of percolation; ω: molar ratio of water to surfactant; IPM: isopropyl myristate; EO: ethyl oleate; IPP: isopropyl palmitate. Highlights: • Percolation temperature depends on contents of water, nonionic surfactant and [NaCl]. • Acetyl modified amino acids retard the temperature-induced percolation process. • The clustering process is spontaneous, endothermic and entropically driven. • Enthalpy and entropy of clustering process increase with increasing nonionic content. • Chemical structures of oils influence thermodynamic parameters of droplet clustering. -- Abstract: Temperature-induced percolation behavior in mixed reverse micellar systems (RMs) comprising sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and polyoxyethylene(20) sorbitan trioleate (Tween-85) in polar lipophilic oils e.g., ethyl oleate (EO), isopropyl myristate (IPM) and isopropyl palmitate (IPP) was studied at a total surfactant concentration (ST) of 0.25 ⋅ 103 mol ⋅ m−3 in absence and presence of the additives (acetyl modified amino acids (MAA) of different chemical structures). The threshold temperature of percolation (Tp) of these systems was found to be dependent on water content (ω), content of nonionic surfactant (XTween-85), and concentration of NaCl. The standard free energy change (ΔGcl0), enthalpy change (ΔHcl0) and entropy change (ΔScl0) of cluster formation were evaluated based on an association model at different physicochemical environments. The clustering process was spontaneous and found to be endothermic and entropically driven. Scaling laws for the temperature-induced percolation demonstrated dynamic nature of the percolation process. The activation energy, Ep of these systems was estimated both in absence and presence of additives. Droplet sizes of these systems were measured using dynamic light scattering (DLS) technique at different physicochemical environments (comparable to conductivity measurements) to

  8. Application of time reversal in underwater communication

    Institute of Scientific and Technical Information of China (English)

    LU Minghui; ZHANG Bixing; WANG Chenghao

    2004-01-01

    Time reversal is applied to the underwater spreading spectrum coding communication. On the base of analyzing the focusing characteristics of the time reversal in underwater waveguide, the time reversal is studied to overcome the wave distortion of the encoded signal caused by the multi-path effect. The experiment research for underwater coding communication is carried out in a lab water tank and the corresponding theoretical analysis is also conducted by Binary Phase Shift Keying (BPSK) encoding and Barker code with 7 chips for the spreading spectrum signal. The results show that the time reversal can improve the focusing gain and increase the ratio of the principal to the second lobe of the coding signal, and can decrease the bit error rate and increase the communication distance.

  9. Excited state intramolecular charge transfer reaction in non-aqueous reverse micelles: Effects of solvent confinement and electrolyte concentration

    Indian Academy of Sciences (India)

    Tuhin Pradhan; Harun Al Rasid Gazi; Biswajit Guchhait; Ranjit Biswas

    2012-03-01

    Steady state and time resolved fluorescence emission spectroscopy have been employed to investigate the effects of solvent confinement and electrolyte concentration on excited state intramolecular charge transfer (ICT) reaction in 4-(1-pyrrolidinyl) benzonitrile (P5C), 4-(1-piperidinyl) benzonitrile (P6C), and 4-(1-morpholenyl) benzonitrile (M6C) in AOT/n-heptane/acetonitrile and AOT/n-heptane/methanol reverse micelles. Dramatic confinement effects have been revealed via a huge reduction (factor ranging between 100 and 20) over bulk values of both equilibrium and reaction rate constants. A strong dependence on the size of the confinement () of these quantities has also been observed. dependent average static dielectric constant, viscosity and solvation time-scale have been determined. Estimated dielectric constants for confined methanol and acetonitrile show a decrease from the respective bulk values by a factor of 3-5 and viscosities increased by a factor of 2 at the highest considered. Addition of electrolyte at = 5 for acetonitrile is found to produce a linear increase of confined solvent viscosity but leads to a non-monotonic electrolyte concentration dependence of average solvation time. Reaction rate constant is found to decrease linearly with electrolyte concentration for P5C and P6C but non-monotonically for M6C, the highest decrease for all the molecules being ∼ 20% over the value in the absence of added electrolyte in the solvent pool. The observed huge reduction in reaction rate constant is attributed to the effects of decreased solution polarity, enhanced viscosity and slowed-down solvent reorganization of the solvent under confinement in these non-aqueous reverse micelles.

  10. Reverse vending machine update

    Energy Technology Data Exchange (ETDEWEB)

    Rypins, S.; Papke, C.

    1986-02-01

    The document discusses reverse vending machines. Placed outdoors in supermarket parking lots or indoors in the lobby of the grocery market, these hightech machines exchange aluminum cans (or other containers in more specialized machines) for cash, coupons or redeemable receipts. The placement of reverse venders (RV) in or near supermarkets has made recycling more visible and more convenient, although the machines have yet to fully reach industry goals.

  11. PROCESSING REVERSE LOGISTICS INVENTORIES

    OpenAIRE

    Bajor, Ivona; Novačko, Luka; Ogrizović, Dario

    2014-01-01

    Developed logistics systems have organized reverse logistics flows and are continuously analyzing product returns, tending to detect patterns in oscillations of returning products in certain time periods. Inventory management in reverse logistics systems depends on different criteria, regarding goods categories, formed contracts between subjects of supply chains, uncertainty in manufacturer’s quantities of DOA (dead on arrival) products, etc. The developing logistics systems, such as the Croa...

  12. Vasectomy reversal in humans

    OpenAIRE

    Bernie, Aaron M.; Osterberg, E Charles; Stahl, Peter J.; Ramasamy, Ranjith; Goldstein, Marc

    2012-01-01

    Vasectomy is the most common urological procedure in the United States with 18% of men having a vasectomy before age 45. A significant proportion of vasectomized men ultimately request vasectomy reversal, usually due to divorce and/or remarriage. Vasectomy reversal is a commonly practiced but technically demanding microsurgical procedure that restores patency of the male excurrent ductal system in 80–99.5% of cases and enables unassisted pregnancy in 40–80% of couples. The discrepancy between...

  13. On thermodynamic and microscopic reversibility

    Energy Technology Data Exchange (ETDEWEB)

    Crooks, Gavin E.

    2011-07-12

    The word 'reversible' has two (apparently) distinct applications in statistical thermodynamics. A thermodynamically reversible process indicates an experimental protocol for which the entropy change is zero, whereas the principle of microscopic reversibility asserts that the probability of any trajectory of a system through phase space equals that of the time reversed trajectory. However, these two terms are actually synonymous: a thermodynamically reversible process is microscopically reversible, and vice versa.

  14. Water

    International Nuclear Information System (INIS)

    An up-date overview of the situation of the Austrian waters is given by analyzing the status of the water quality (groundwater, surface waters) and water protection measures. Maps containing information of nitrate and atrazine in groundwaters (analyses at monitoring stations), nitrate contents and biological water quality of running waters are included. Finally, pollutants (nitrate, orthophosphate, ammonium, nitrite, atrazine etc.) trends in annual mean values and median values for the whole country for the years 1992-1999 are presented in tables. Figs. 5. (nevyjel)

  15. Reverse electrodialysis : evaluation of suitable electrode systems

    NARCIS (Netherlands)

    Veerman, J.; Saakes, M.; Metz, S. J.; Harmsen, G. J.

    2010-01-01

    Reverse electrodialysis (RED) is a method for directly extracting electrical energy from salinity gradients, especially from sea and river water. For the commercial implementation of RED, the electrode system is a key component. In this paper, novel electrode systems for RED were compared with exist

  16. Chemical recycling of carbon dioxide emissions from a cement plant into dimethyl ether, a case study of an integrated process in France using a Reverse Water Gas Shift (RWGS) step

    International Nuclear Information System (INIS)

    Recycling of carbon dioxide (CO2) and hydrogen (H2) into liquid fuel technology has recently gained wide public interest since it is a potential pathway to increase the liquid fuel supply and to mitigate CO2 emissions simultaneously. In France, the majority of the electricity production is derived from nuclear and renewable energy which have a low CO2 footprint. This electricity power enables a potential for massive hydrogen production with low carbon emissions. We studied the possibility to develop this technology at an industrial scale in the French context on a typical industrial example of a cement manufacture in the south of France. An integrated process is proposed, which enables the use of the heat released by the CO2 to fuel process to help to capture the CO2 released by the cement manufacture. Some technological issues are discussed, and a potential solution is proposed for the catalyst used in the critical step of the Reverse Water Gas-Shift reaction (RWGS) of the process. (authors)

  17. Treatment of Reverse Osmosis Concentrated Water in Refinery by Biological Activated Carbon Process%生物活性炭工艺处理炼油厂反渗透浓缩水

    Institute of Scientific and Technical Information of China (English)

    徐传海; 魏新; 郦和生; 王岽

    2011-01-01

    The reverse osmosis concentrated water in refinery was treated by biological activated carbon process. Under the conditions of cracked-anthracite-made activated carbon size 2. 4 -5. 9 mm, influent pH 7. 5, empty bed residence time 30 min and average influent COD 100 mg/L, the system can keep stable running for 48 d, the average removal rates of COD and A2Si are 50% and 77% respectively, and the effluent COD is below 60 mg/L, which can meet the first grade discharge standard of GB8978 - 1996.%采用生物活性炭工艺处理炼油厂反渗透浓缩水.在无烟煤破碎炭粒径为2.4~5.9 mm、进水pH为7.5、空床停留时间为30 min、平均进水COD为100 mg/L的条件下,系统可稳定运行48 d,平均COD去除率为50%,平均A254(反渗透浓缩水在波长254 nm处的吸光度)降低率为77%,出水COD低于60 mg/L,达到GB8978-1996《污水综合排放标准》中的一级排放标准.

  18. 微萃取/反相液相色谱法测定水中苯甲酰脲类农药%Determination of Benzoylurea Insecticides in Water by Microextraction Flask/Reversed-phase Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    周建科; 杨冬霞; 徐鹏

    2011-01-01

    A method using microextraction enrichment and reversed-phase high-performance liquid chromatography was used for determination of benzoylurea insecticides in surface water.The sample was extracted by isooctane.Benzoylurea insecticides were separated on Diamonsil C18 column with acetonitrile∶ methanol∶ water= 20∶ 65∶ 15 as mobile phase and determined using UV detector at 260 nm.For triflumuron, hexaflumuron and teflubenzuron, the average recoveries are 92.23%, 102.18% and 89.77% respectively.The relative standard deviations are less than 5.7%.The linearity is good in the range of 0.5 to 100 μg/mL with the correlation coefficients of equal to or more than 0.999 8.%以异辛烷作萃取剂,采用微萃取瓶富集,用反相高效液相色谱法测定地表水中的苯甲酰脲类农药.检测条件如下:Diamonsil C色谱柱,乙腈:甲醇:水=20:65:15流动相,260 nm紫外检测.该方法检测杀铃脲、氟铃脲和氟苯脲的平均回收率分别为92.23%、102.18%和89.77%,相对标准偏差<5.7%,在0.5~100μg/mL范围内三组分线性良好,相关系数≥0.999 8.

  19. Emerging micropollutants in water/wastewater: growing demand on removal technologies.

    Science.gov (United States)

    Trapido, M; Epold, I; Bolobajev, J; Dulova, N

    2014-11-01

    Developing advanced treatment technologies for improving the removal of micropollutants in water/wastewater is important. A suitable treatment is more likely to be used as the polishing step in the treatment scheme. Advanced oxidation technologies (AOTs) are relevant for removing micropollutants. The ability of direct UV photolysis and selected AOTs to degrade pharmaceuticals, endocrine-disrupting compound and herbicide has been studied and compared. The tested methods resulted in the degradation of the studied micropollutants; however, none of the methods was preferred for the removal of all tested compounds. The UV-active processes have strong potential for removal of the studied micropollutants. The utilisation of a moderate hydrogen peroxide admixture resulted in a more reliable treatment. PMID:24840356

  20. Logical Reversibility and Physical Reversibility in Quantum Measurement

    OpenAIRE

    Ueda, Masahito

    1997-01-01

    A quantum measurement is logically reversible if the premeasurement density operator of the measured system can be calculated from the postmeasurement density operator and from the outcome of the measurement. This paper analyzes why many quantum measurements are logically irreversible, shows how to make them logically reversible, and discusses reversing measurement that returns the postmeasurement state to the premeasurement state by another measurement (physical reversibility). Reversing mea...

  1. Economic impact of reversion

    International Nuclear Information System (INIS)

    Estimations of the Norwegian hydropower production and various reversion models' market value have been made. The value of the Norwegian hydropower production until 01.01.2007 is estimated to about Nok 289 billion after taxes, or about 2,42 Nok/kWh medium production, given an expected future electricity price of around 0,25 Nok/kWh and a discount rate at 6,5 percent in nominal terms after taxes. The estimate is slightly above the level of prices for Norwegian hydropower plants in the last 8-10 years. The value of reversion in private plants which today have a limited licence time is estimated to Nok 5,5 billion. The value of reversion in public-owned Norwegian hydropower plants are about Nok 21 billion with a 60 year licence period from 01.01.2007, and about 12 billion for 75 years (ml)

  2. Reversed extension flow

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Rasmussen, Henrik K.

    2008-01-01

    Afilament stretching rheometer (FSR) was used for measuring the start-up of uni-axial elongational flow followed by reversed bi-axial flow, both with a constant elongational rate. A narrow molecular mass distribution linear polystyrene with a molecular weight of 145 kg / mole wis subjected to the...... start-up of elongation for three Hencky strain units and subsequently the reversed flow. The integral molecular stress function formulation within the 'interchain pressure' concept agrees with the experiments. In the experiments the Hencky strain at which the str~ss becomes zero (the recovery strain) in...... the reversed flow has been identified. The recovery strain is found to increase with elongational rate, and has a maximum value of approximately 1.45. The Doi Edwards model using any stretch evolution equation is not able to predict the correct level of the recovery strain....

  3. Reversible deep disposal

    International Nuclear Information System (INIS)

    This presentation, given by the national agency of radioactive waste management (ANDRA) at the meeting of October 8, 2009 of the high committee for the nuclear safety transparency and information (HCTISN), describes the concept of deep reversible disposal for high level/long living radioactive wastes, as considered by the ANDRA in the framework of the program law of June 28, 2006 about the sustainable management of radioactive materials and wastes. The document presents the social and political reasons of reversibility, the technical means considered (containers, disposal cavities, monitoring system, test facilities and industrial prototypes), the decisional process (progressive development and blocked off of the facility, public information and debate). (J.S.)

  4. Climatology Analysis of Aerosol Effect on Marine Water Cloud from Long-Term Satellite Climate Data Records

    OpenAIRE

    Xuepeng Zhao; Andrew K. Heidinger; Andi Walther

    2016-01-01

    Satellite aerosol and cloud climate data records (CDRs) have been used successfully to study the aerosol indirect effect (AIE). Data from the Advanced Very High Resolution Radiometer (AVHRR) now span more than 30 years and allow these studies to be conducted from a climatology perspective. In this paper, AVHRR data are used to study the AIE on water clouds over the global oceans. Correlation analysis between aerosol optical thickness (AOT) and cloud parameters, including cloud droplet effecti...

  5. Studies on Model Water-in-Oil (w/o) Emulsions: Phase Behavior, Emulsion Stability, and Hydrate Formation

    OpenAIRE

    Hu, Qiufei; Kelkar, Aniruddha V.; Corti, David S.; Franses, Elias I.

    2014-01-01

    Colloidal dispersions are widely encountered in several industrial settings including in ink, paint, and food formulations, as well as during subsea oil production. The present study focusses on the formation of hydrates in subsea oil pipelines from colloidal precursors that cause plugging and have tremendous environmental and economic consequences. Model systems for hydrate precursors are studied – water in cyclopentane emulsions stabilized by either SPAN 80 or AOT surfactants. The phase beh...

  6. Characterization of hereditarily reversible posets

    OpenAIRE

    Kukieła, Michał

    2013-01-01

    A poset P is called reversible if every order preserving bijective self map of P is an order automorphism. P is called hereditarily reversible if every subposet of P is reversible. We give a complete characterization of hereditarily reversible posets in terms of forbidden subsets. A similar result is stated also for preordered sets. As a corollary we extend the list of known examples of hereditarily reversible topological spaces.

  7. Cerium oxide nanoparticles coated by surfactant sodium bis(2-ethylhexyl) sulphosuccinate (AOT): local atomic structures and x-ray absorption spectroscopic studies

    International Nuclear Information System (INIS)

    Cerium oxide nanoparticles coated by sodium bis(2-ethylhexyl) sulphosuccinate (AOT) were prepared by using a microemulsion method. Transmission electron microscopy revealed an average particle size of 2-3 nm. X-ray diffraction showed that the cerium oxide nanoparticles retain the CeF2-type cubic structures like the bulk crystal. The intermediate valence of formally tetravalent compounds had been detected by x-ray-absorption near-edge structure (XANES) spectra of Ce LIII absorption in bulk CeO2 and the cerium oxide nanoparticles. Two well resolved white lines can be assigned to the electron configurations of 4f0L and 4f1L, respectively, where L denotes a ligand hole. At the same time, the cerium oxide nanoparticles also showed the structural features of trivalent compounds, in comparison to the trivalent Ce(NO3)3·6H2O. Four Lorentzian functions and two arctan functions were used to fit the normalized XANES spectra. The extended x-ray-absorption fine-structure (EXAFS) technique was used to probe the local atomic structures around the absorber Ce. The multielectron excitation effect on the EXAFS spectra was eliminated. A core-shell model was used to deduce the near-neighbour structural parameters around cerium. Bulk CeO2 with eight oxygen atoms located at 2.343 A was used as the reference sample to extract the backscattering amplitude and phase shift of the Ce-O bond. One half of the atoms locate at the core part with the CeF2-type cubic structures (eight oxygens at 2.343 A around Ce), the other half of the atoms are amorphous phase located in the shell part (surface of the nanoparticles) with approximately Ce2O3 structural features (averaged seven oxygens at 2.50 A around Ce). (author)

  8. Reversing insect pollinator decline

    OpenAIRE

    Potts, Simon; Wentworth, Jonathan

    2013-01-01

    Pollination by insects enables the reproduction of flowering plants and is critical to UK agriculture.1 Insect pollinators have declined globally, with implications for food security and wild habitats. This POSTnote summarises the causes for the recent trends, gaps in knowledge and possible strategies for reversing pollinator decline.

  9. Reversal Strategies for NOACs

    DEFF Research Database (Denmark)

    Husted, Steen; Verheugt, Freek; Comuth, Willemijn

    2015-01-01

    , coagulation factor concentrates or NOAC-specific antidotes could be used. Coagulation factor concentrates can be used in patients with haemophilia and to reverse the effect of VKAs but, in NOAC-treated patients, results are inconsistent and these agents could potentially have pro-thrombotic effects. Specific...

  10. Reversible focal splenial lesions

    Energy Technology Data Exchange (ETDEWEB)

    Gallucci, Massimo; Limbucci, Nicola [University of L' Aquila, Department of Radiology, S. Salvatore Hospital, L' Aquila (Italy); Paonessa, Amalia [Loreto Nuovo Hospital, Department of Neuroradiology, Napoli (Italy); Caranci, Ferdinando [Federico II University, Department of Neurological Sciences, Napoli (Italy)

    2007-07-15

    Reversible focal lesions in the splenium of the corpus callosum (SCC) have recently been reported.They are circumscribed and located in the median aspect of the SCC. On MRI, they are hyperintense on T2-W and iso-hypointense on T1-W sequences, with no contrast enhancement. On DWI, SCC lesions are hyperintense with low ADC values, reflecting restricted diffusion due to cytotoxic edema. The common element is the disappearance of imaging abnormalities with time, including normalization of DWI. Clinical improvement is often reported. The most established and frequent causes of reversible focal lesions of the SCC are viral encephalitis, antiepileptic drug toxicity/withdrawal and hypoglycemic encephalopathy. Many other causes have been reported, including traumatic axonal injury. The similar clinical and imaging features suggest a common mechanism induced by different pathological events leading to the same results. Edema and diffusion restriction in focal reversible lesions of the SCC have been attributed to excitotoxic mechanisms that can result from different mechanisms; no unifying relationship has been found to explain all the pathologies associated with SCC lesions. In our opinion, the similar imaging, clinical and prognostic aspects of these lesions depend on a high vulnerability of the SCC to excitotoxic edema and are less dependent on the underlying pathology. In this review, the relevant literature concerning reversible focal lesions in the SCC is analyzed and hypotheses about their pathogenesis are proposed. (orig.)

  11. Reverse Coherent Information

    Science.gov (United States)

    García-Patrón, Raúl; Pirandola, Stefano; Lloyd, Seth; Shapiro, Jeffrey H.

    2009-05-01

    In this Letter we define a family of entanglement distribution protocols assisted by feedback classical communication that gives an operational interpretation to reverse coherent information, i.e., the symmetric counterpart of the well-known coherent information. This leads to the definition of a new entanglement distribution capacity that exceeds the unassisted capacity for some interesting channels.

  12. Reverse Shoulder Arthroplasty

    Medline Plus

    Full Text Available Reverse Shoulder Arthroplasty Zimmer, Inc. New York City, New York March 17, 2010 Welcome to this OR Live presentation, brought to you by Zimmer. Hi. I'm ... my partner, Brad Parsons. We're here in New York to bring you a video of a ...

  13. Reverse Coherent Information

    OpenAIRE

    García-Patrón, Raúl; Pirandola, Stefano; Lloyd, Seth; Shapiro, Jeffrey H.

    2008-01-01

    In this letter we define a family of entanglement distribution protocols assisted by feedback classical communication that gives an operational interpretation to reverse coherent information, i.e., the symmetric counterpart of the well known coherent information. This lead to the definition of a new entanglement distribution capacity that exceeds the unassisted capacity for some interesting channels.

  14. Non-Thermal Plasma (NTP) session overview: Second International Symposium on Environmental Applications of Advanced Oxidation Technologies (AOTs)

    International Nuclear Information System (INIS)

    Advanced Oxidation Technologies (used in pollution control and treating hazardous wastes) has expanded from using hydroxyl radicals to treat organic compounds in water, to using reductive free radicals as well, and to application to pollutants in both gases and aqueous media. Non-Thermal Plasma (NTP) is created in a gas by an electrical discharge or energetic electron injection. Highly reactive species (O atoms, OH, N radicals, plasma electrons) react with entrained hazardous organic chemicals in the gas, converting them to CO2, H2O, etc. NTP can be used to simultaneously remove different kinds of pollutants (eg, VOCs, SOx, NOx in flue gases). This paper presents an overview of NTP technology for pollution control and hazardous waste treatment; it is intended as an introduction to the NTP session of the symposium

  15. Study on Health Safety of Fine Drinking Water by Reverse Osmosis Membrane%反渗透膜制终端直饮水的健康安全性考察

    Institute of Scientific and Technical Information of China (English)

    庞小燕; 宿程远; 黄小玲; 吕明; 陈晶; 黄意

    2011-01-01

    通过动态试验,考察了反渗透膜制终端直饮水系统对有机物、TDS、氨氮、UV254以及硝酸盐等的去除效果;同时分析了进水UV254与CODMn的相关性。试验表明:该系统对CODMnTDS与硝酸盐氮的平均去除率分别为60%、95%和86%,出水的氨氮浓度基本为0;该系统对UV25。的平均去除率为90%,可保证饮水水质安全;同时试验表明进水UV254与CODMn之间有一定的相关性。%The removal effects for organic matters, TDS, NH4 -N, UV254 and nitrate nitrogen by reverse osmosis (RO) system were reviewed through dynamic experiments. This paper also analyzes the correlation between the inflow CODMn and UV254. The results showed that the removal rates of CODM., TDS and nitrate nitrogen by RO system were 60%, 95% and 86% respectively. The NH4 - N concentration of effluent was nearly zero. The average UV254 removal rate was 90%. The health safety of the drinking water is secured and the experiments also proved a certain degree of correlation between the inflow UV254 and CODMn.

  16. Gridded electron reversal ionizer

    Science.gov (United States)

    Chutjian, Ara (Inventor)

    1993-01-01

    A gridded electron reversal ionizer forms a three dimensional cloud of zero or near-zero energy electrons in a cavity within a filament structure surrounding a central electrode having holes through which the sample gas, at reduced pressure, enters an elongated reversal volume. The resultant negative ion stream is applied to a mass analyzer. The reduced electron and ion space-charge limitations of this configuration enhances detection sensitivity for material to be detected by electron attachment, such as narcotic and explosive vapors. Positive ions may be generated by generating electrons having a higher energy, sufficient to ionize the target gas and pulsing the grid negative to stop the electron flow and pulsing the extraction aperture positive to draw out the positive ions.

  17. Reverse engineering software ecosystems

    OpenAIRE

    Lungu, Mircea F.; Lanza, Michele

    2009-01-01

    Reverse engineering is an active area of research concerned with the development of techniques and tools that support the understanding of software systems. All the techniques that were pro- posed until now study individual systems in isolation. However, software systems are seldom developed in isolation; instead, they are developed together with other projects in the wider context of an organization. We call the collection of projects that are developed in such a con- text a software ...

  18. Time-reversal acoustics

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Mathias [Laboratoire Ondes et Acoustique, Ecole Superieure de Physique et de Chimie Industrielle de la Ville de Paris, Universite Denis Diderot, UMR CNRS 7587, 10 Rue Vauquelin, 75005 Paris (France)], E-mail: mathias.fink@espci.fr

    2008-10-15

    Time-reversal mirrors (TRMs) refocus an incident acoustic field to the position of the original source regardless of the complexity of the propagation medium. TRM's have now been implemented in a variety of physical scenarios from MHz ultrasonics with order centimeter aperture size to hundreds/thousands of Hz in ocean acoustics with order hundred meter aperture size. Common to this broad range of scales is a remarkable robustness exemplified by observations at all scales that the more complex the medium between the probe source and the TRM, the sharper the focus. The relation between the medium complexity and the size of the focal spot is studied in this paper. It is certainly the most exciting property of TRM compared to standard focusing devices. A TRM acts as an antenna that uses complex environments to appears wider than it is, resulting for a broadband pulse in a refocusing quality that does not depend of the TRM aperture. In this paper, we investigate the time-reversal approach in various media of increasing complexity and we discuss the link existing between time-reversal approach and local helioseismology where Green's functions can be extracted from diffusive noise.

  19. Designing Parity Preserving Reversible Circuits

    OpenAIRE

    Paul, Goutam; Chattopadhyay, Anupam; Chandak, Chander

    2013-01-01

    Making a reversible circuit fault-tolerant is much more difficult than classical circuit and there have been only a few works in the area of parity-preserving reversible logic design. Moreover, all of these designs are ad hoc, based on some pre-defined parity preserving reversible gates as building blocks. In this paper, we for the first time propose a novel and systematic approach towards parity preserving reversible circuits design. We provide some related theoretical results and give two a...

  20. A Study on Reverse Logistics

    OpenAIRE

    Reddy, Dhananjaya

    2011-01-01

    In the competitive world of manufacturing, companies are often searching for new ways to improve their process, customer satisfaction and stay ahead in the game with their competitors. Reverse logistics has been considered a strategy to bring these things to life for the past decade or so. This thesis work tries to shed some light on the basics of reverse logistics and how reverse logistics can be used as a management strategy. This paper points out the fundamentals of reverse logistics and l...

  1. Reverse Engineering of RFID devices

    OpenAIRE

    Bokslag, Wouter

    2015-01-01

    This paper discusses the relevance and potential impact of both RFID and reverse engineering of RFID technology, followed by a discussion of common protocols and internals of RFID technology. The focus of the paper is on providing an overview of the different approaches to reverse engineering RFID technology and possible countermeasures that could limit the potential of such reverse engineering attempts.

  2. REVIEWS OF TOPICAL PROBLEMS: Waves and patterns in reaction-diffusion systems. Belousov-Zhabotinsky reaction in water-in-oil microemulsions

    Science.gov (United States)

    Vanag, Vladimir K.

    2004-09-01

    Advances in nonequilibrium pattern formation in reaction-diffusion systems are reviewed. Special emphasis is placed on patterns found in the spatially extended Belousov-Zhabotinsky reaction dispersed in aerosol OT water-in-oil microemulsions (BZ-AOT system): Turing patterns, packet and standing waves, antispirals and segmented spirals, and accelerating waves and oscillons. All experimental results are explained theoretically and reproduced in computer simulations.

  3. Reversible brazing process

    Science.gov (United States)

    Pierce, Jim D.; Stephens, John J.; Walker, Charles A.

    1999-01-01

    A method of reversibly brazing surfaces together. An interface is affixed to each surface. The interfaces can be affixed by processes such as mechanical joining, welding, or brazing. The two interfaces are then brazed together using a brazing process that does not defeat the surface to interface joint. Interfaces of materials such as Ni-200 can be affixed to metallic surfaces by welding or by brazing with a first braze alloy. The Ni-200 interfaces can then be brazed together using a second braze alloy. The second braze alloy can be chosen so that it minimally alters the properties of the interfaces to allow multiple braze, heat and disassemble, rebraze cycles.

  4. Reverse engineering SPARQL queries

    OpenAIRE

    Arenas, M; Diaz, GI; Kostylev, E

    2016-01-01

    Semantic Web systems provide open interfaces for end-users to access data via a powerful high-level query language, SPARQL. But users unfamiliar with either the details of SPARQL or properties of the target dataset may find it easier to query by example — give examples of the information they want (or examples of both what they want and what they do not want) and let the system reverse engineer the desired query from the examples. This approach has been heavily used in th...

  5. Reverse Engineering Malicious Applications

    Directory of Open Access Journals (Sweden)

    Ioan Cristian Iacob

    2015-06-01

    Full Text Available Detecting new and unknown malware is a major challenge in today’s software. Security profession. A lot of approaches for the detection of malware using data mining techniques have already been proposed. Majority of the works used static features of malware. However, static detection methods fall short of detecting present day complex malware. Although some researchers proposed dynamic detection methods, the methods did not use all the malware features. In this work, an approach for the detection of new and unknown malware was proposed and implemented. Each sample was reverse engineered for analyzing its effect on the operating environment and to extract the static and behavioral features. 

  6. Reversal of dental fluorosis: A clinical study

    OpenAIRE

    Dhaval N Mehta; Shah, Jigna

    2013-01-01

    Aim: This study was conducted to evaluate the clinical reversal of dental fluorosis with various combinations of calcium, vitamin D3, and ascorbic acid, along with changes in levels of certain biochemical parameters concerned with dental fluorosis. The role of fluoride level of drinking water in the etiology of dental fluorosis and the prevalence of dental fluorosis in both dentitions and teeth were also assessed. Materials and Methods: A total number of 50 patients with clinical features of ...

  7. What Do Reversible Programs Compute?

    DEFF Research Database (Denmark)

    Axelsen, Holger Bock; Glück, Robert

    2011-01-01

    Reversible computing is the study of computation models that exhibit both forward and backward determinism. Understanding the fundamental properties of such models is not only relevant for reversible programming, but has also been found important in other fields, e.g., bidirectional model...... transformation, program transformations such as inversion, and general static prediction of program properties. Historically, work on reversible computing has focussed on reversible simulations of irreversible computations. Here, we take the viewpoint that the property of reversibility itself should be the...... starting point of a computational theory of reversible computing. We provide a novel semantics-based approach to such a theory, using reversible Turing machines (RTMs) as the underlying computation model. We show that the RTMs can compute exactly all injective, computable functions. We find that the RTMs...

  8. Reverse Quantum Waves

    Science.gov (United States)

    Boyd, Jeffrey

    2010-02-01

    As preposterous as it might sound, if quantum waves travel in the reverse direction from subatomic particles, then most of quantum physics can be explained without quantum weirdness or Schr"odinger's cat. Quantum mathematics is unchanged. The diffraction pattern on the screen of the double slit experiment is the same. This proposal is not refuted by the Innsbruck experiments; this is NOT a hidden local variable theory. Research evidence will be presented that is consistent with the idea waves travel in the opposite direction as neutrons. If one's thinking shifts from forwards to backwards quantum waves, the world changes so drastically it is almost unimaginable. Quantum waves move from the mathematical to the real world, multiply in number, and reverse in direction. Wave-particle duality is undone. In the double slit experiment every part of the target screen is emitting such quantum waves in all directions. Some pass through the two slits. Interference occurs on the opposite side of the barrier than is usually imagined. They impinge on ``S'' and an electron is released at random. Because of the interference it is more likely to follow some waves than others. It follows one and only one wave backward; hitting the screen where it's wave originated. )

  9. Reversibly Bistable Flexible Electronics

    KAUST Repository

    Alfaraj, Nasir

    2015-05-01

    Introducing the notion of transformational silicon electronics has paved the way for integrating various applications with silicon-based, modern, high-performance electronic circuits that are mechanically flexible and optically semitransparent. While maintaining large-scale production and prototyping rapidity, this flexible and translucent scheme demonstrates the potential to transform conventionally stiff electronic devices into thin and foldable ones without compromising long-term performance and reliability. In this work, we report on the fabrication and characterization of reversibly bistable flexible electronic switches that utilize flexible n-channel metal-oxide-semiconductor field-effect transistors. The transistors are fabricated initially on rigid (100) silicon substrates before they are peeled off. They can be used to control flexible batches of light-emitting diodes, demonstrating both the relative ease of scaling at minimum cost and maximum reliability and the feasibility of integration. The peeled-off silicon fabric is about 25 µm thick. The fabricated devices are transferred to a reversibly bistable flexible platform through which, for example, a flexible smartphone can be wrapped around a user’s wrist and can also be set back to its original mechanical position. Buckling and cyclic bending of such host platforms brings a completely new dimension to the development of flexible electronics, especially rollable displays.

  10. Preparations of nanosized TiO{sub 2} in reverse microemulsion and their photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Man Sig; Lee, Gun-Dae; Ju, Chang-Sik; Hong, Seong-Soo [Division of Chemical Engineering, Pukyong National University, San 100 Yongdang-dong, Nam-Ku, Pusan 608-739 (Korea, Republic of)

    2005-09-15

    Nanosized titania sol has been produced by the controlled hydrolysis of titanium tetraisopropoxide (TTIP) in sodium bis(2-ethylhexyl)sulfosuccinate (AOT) reverse micelles. The physical properties, such as surface area, crystallite size and crystallinity according to R and W{sub 0} ratio, have been investigated by TEM, XRD, BET, FT-IR, TGA and DTA. In addition, the photocatalytic decomposition of p-nitrophenol has been studied by using a batch reactor in the presence of UV light in order to compare the photocatalytic activity of prepared nanosized titania. It is shown that the anatase structure appears in the 300-600{sup o}C calcination temperature range and the transformation of anatase into rutile starts above 700{sup o}C. The crystallite size increases with increasing R and W{sub 0} ratio but W{sub 0} ratio shows a stronger effect on the crystallite size than R ratio. In the photocatalytic decomposition of p-nitrophenol, the photocatalytic activity is mainly determined by the crystallinity of titania. In addition, the titania calcined at 500{sup o}C shows the highest activity on the photocatalytic decomposition of p-nitrophenol(k=5.6x10{sup -3}min{sup -1}) and the pure anatase structure.

  11. Effects of residual scale inhibitors on the performance of reverse osmosis membrane in blow-down water from circulating water system%循环水排污水中残余阻垢剂对反渗透膜性能的影响

    Institute of Scientific and Technical Information of China (English)

    杨伟; 刘芳; 高雅; 闫茜; 张利

    2015-01-01

    循环水排污水中残余的阻垢剂会导致其水质的变化,从而影响反渗透膜性能。本文以循环水中常用的阻垢剂聚天冬氨酸(PASP)、羟基亚乙基=膦酸(HEDP)和氨基三亚甲基膦酸(ATMP)为研究对象,首先考察了它们的阻垢性能,然后在此基础上,通过静态浸泡试验和动态试验考察了它们的存在对反渗透膜性能的影响。研究结果表明,PASP、HEDP和ATMP中,PASP的阻垢性能最优,阻垢率高达84.21%,三者均会对反渗透膜的表面结构、组成成分、膜通量以及脱盐率产生一定的影响。当PASP、HEDP和ATMP的浓度分别为50mg/L、10mg/L和30mg/L时,在反渗透系统连续运行10h后,膜通量分别下降5.53%、4.89%和9.09%,小于空白时的18.95%;此外,脱盐率有不同程度的提高。%Residual scale inhibitors can cause water quality changes in circulating cooling process,thus affect the performances of reverse osmosis membrane. This study investigated the scale inhibition performance of scale inhibitors,PASP,HEDP and ATMP. The effects on the performance of reverse osmosis membrane were investigated by static test and dynamic test. Results showed that among PASP,HEDP and ATMP,the scale inhibition performances of PASP were best and scale inhibition rate could be as high as 84.21%. All the three materials had certain effects on the surface of the reverse osmosis membrane structure,composition and membrane flux. When the concentration of PASP, HEDP and ATMP was 50mg/L,10mg/L and 30mg/L respectively,the membrane flux decreased by 5.53%,4.89%,9.09%,less than 18.95% of the blank solution. In addition,desalination rates increased.

  12. Reversible posterior leukoencephalopathy syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Ja; Yu, Won Jong; Ahn, Kook Jin; Jung, So Lyung; Lee, Yeon Soo; Kim, Ji Chang; Kang, Si Won [The Catholic Univ. of Korea, Taejon (Korea, Republic of); Song, Chang Joon [Chungnam National Univ. School of Medicine, Cheonju (Korea, Republic of); Song, Soon-Young; Koo, Ja Hong [Kwandong Univ. College of Medicine, Myungji Hospital, Seoul (Korea, Republic of); Kim, Man Deuk [College of Medicine Pochon CHA Univ., Seoul (Korea, Republic of)

    2001-10-01

    To review reversible posterior leukoencephalopathy syndrome. We reviewed 22 patients (M:F=3:19; age, 17-46 years) with the characteristic clinical and imaging features of reversible posterior leukoencephalopathy syndrome. All underwent brain MRI, and in three cases both CT and MRI were performed. In one, MRA was obtained, and in eleven, follow-up MR images were obtained. We evaluated the causes of this syndrome, its clinical manifestations, and MR findings including the locations of lesions, the presence or absence of contrast enhancement, and the changes seen at follow-up MRI. Of the 22 patients, 13 had eclampsia (six during pregnancy and seven during puerperium). Four were receiving immunosuppressive therapy (three, cyclosporine ; one, FK 506). Four suffered renal failure and one had complicated migraine. The clinical manifestations included headache (n=12), visual disturbance (n=13), seizure (n=15), focal neurologic sign (n=3), and altered mental status (n=2). Fifteen patients had hypertension and the others normotension. MRI revealed that lesions were bilateral (n=20) or unilateral (n=2). In all patients the lesion was found in the cortical and subcortical areas of the parieto-occipital lobes ; other locations were the basal ganglia (n=9), posterior temporal lobe (n=8), frontal lobe (n=5), cerebellum (n=5), pons (n=2), and thalamus (n=1). All lesions were of high signal intensity on T2-weighted images, and of iso to low intensity on T1-weighted images. One was combined with acute hematoma in the left basal ganglia. In eight of 11 patients who underwent postcontrast T1-weighted MRI, there was no definite enhancement ; in one, enhancement was mild, and in tow, patchy. CT studies showed low attenuation, and MRA revealed mild vasospasm. The symptoms of all patients improved. Follow-up MRI in nine of 11 patients depicted complete resolution of the lesions ; in two, small infarctions remained but the extent of the lesions had decreased. Reversible posterior

  13. Reversible posterior leukoencephalopathy syndrome

    International Nuclear Information System (INIS)

    To review reversible posterior leukoencephalopathy syndrome. We reviewed 22 patients (M:F=3:19; age, 17-46 years) with the characteristic clinical and imaging features of reversible posterior leukoencephalopathy syndrome. All underwent brain MRI, and in three cases both CT and MRI were performed. In one, MRA was obtained, and in eleven, follow-up MR images were obtained. We evaluated the causes of this syndrome, its clinical manifestations, and MR findings including the locations of lesions, the presence or absence of contrast enhancement, and the changes seen at follow-up MRI. Of the 22 patients, 13 had eclampsia (six during pregnancy and seven during puerperium). Four were receiving immunosuppressive therapy (three, cyclosporine ; one, FK 506). Four suffered renal failure and one had complicated migraine. The clinical manifestations included headache (n=12), visual disturbance (n=13), seizure (n=15), focal neurologic sign (n=3), and altered mental status (n=2). Fifteen patients had hypertension and the others normotension. MRI revealed that lesions were bilateral (n=20) or unilateral (n=2). In all patients the lesion was found in the cortical and subcortical areas of the parieto-occipital lobes ; other locations were the basal ganglia (n=9), posterior temporal lobe (n=8), frontal lobe (n=5), cerebellum (n=5), pons (n=2), and thalamus (n=1). All lesions were of high signal intensity on T2-weighted images, and of iso to low intensity on T1-weighted images. One was combined with acute hematoma in the left basal ganglia. In eight of 11 patients who underwent postcontrast T1-weighted MRI, there was no definite enhancement ; in one, enhancement was mild, and in tow, patchy. CT studies showed low attenuation, and MRA revealed mild vasospasm. The symptoms of all patients improved. Follow-up MRI in nine of 11 patients depicted complete resolution of the lesions ; in two, small infarctions remained but the extent of the lesions had decreased. Reversible posterior

  14. Partial Reversible Gates(PRG) for Reversible BCD Arithmetic

    OpenAIRE

    Thapliyal, Himanshu; Arabnia, Hamid R; Bajpai, Rajnish; Sharma, Kamal K

    2007-01-01

    IEEE 754r is the ongoing revision to the IEEE 754 floating point standard and a major enhancement to the standard is the addition of decimal format. Furthermore, in the recent years reversible logic has emerged as a promising computing paradigm having its applications in low power CMOS, quantum computing, nanotechnology, and optical computing. The major goal in reversible logic is to minimize the number of reversible gates and garbage outputs. Thus, this paper proposes the novel concept of pa...

  15. Multiple stimulus reversible hydrogels

    Science.gov (United States)

    Gutowska, Anna; Krzyminski, Karol J.

    2006-04-25

    A polymeric solution capable of gelling upon exposure to a critical minimum value of a plurality of environmental stimuli is disclosed. The polymeric solution may be an aqueous solution utilized in vivo and capable of having the gelation reversed if at least one of the stimuli fall below, or outside the range of, the critical minimum value. The aqueous polymeric solution can be used either in industrial or pharmaceutical environments. In the medical environment, the aqueous polymeric solution is provided with either a chemical or radioisotopic therapeutic agent for delivery to a specific body part. The primary advantage of the process is that exposure to one environmental stimuli alone will not cause gelation, thereby enabling the therapeutic agent to be conducted through the body for relatively long distances without gelation occurring.

  16. Reverse photoacoustic standoff spectroscopy

    Science.gov (United States)

    Van Neste, Charles W.; Senesac, Lawrence R.; Thundat, Thomas G.

    2011-04-12

    A system and method are disclosed for generating a reversed photoacoustic spectrum at a greater distance. A source may emit a beam to a target and a detector measures signals generated as a result of the beam being emitted on the target. By emitting a chopped/pulsed light beam to the target, it may be possible to determine the target's optical absorbance by monitoring the intensity of light collected at the detector at different wavelengths. As the wavelength of light is changed, the target may absorb or reject each optical frequency. Rejection may increase the intensity at the sensing element and absorption may decrease the intensity. Accordingly, an identifying spectrum of the target may be made with the intensity variation of the detector as a function of illuminating wavelength.

  17. Arsenic and Antimony Removal from Drinking Water by Point-of-Entry Reverse Osmosis Coupled with Dual Plumbing Distribution - U.S. EPA Demonstration Project at Carmel Elementary School in Carmel, ME -Final Performance Evaluation Report

    Science.gov (United States)

    This report documents the activities performed for and the results obtained from the arsenic and antimony removal treatment technology demonstration project at the Carmel Elementary School (CES) in Carmel, ME. An innovative approach of employing point of entry (POE) reverse osmo...

  18. Graphite-teflon composite bienzyme electrodes for the determination of cholesterol in reversed micelles. Application to food samples.

    Science.gov (United States)

    Peña, N; Ruiz, G; Reviejo, A J; Pingarrón, J M

    2001-03-15

    A bienzyme amperometric composite biosensor for the determination of free and total cholesterol in food samples is reported. Cholesterol oxidase and horseradish peroxidase, together with potassium ferrocyanide as a mediator, are incorporated into a graphite-70% Teflon matrix. The compatibility of this biosensor design with predominantly nonaqueous media allows the use of reversed micelles as working medium. The reversed micelles are formed with ethyl acetate as continuous phase (in which cholesterol is soluble), a 4% final concentration of 0.05 mol L(-1) phosphate buffer solution, pH 7.4, as dispersed phase, and 0.1 mol L(-1) AOT as emulsifying agent. Studies on the repeatability of the amperometric response obtained at +0.10 V, with and without regeneration of the electrode surface by polishing, on the useful lifetime of one single biosensor and on the reproducibility in the fabrication of different pellets illustrate the robustness of the biosensor design. Determination of free and total cholesterol in food samples such as butter, lard, and egg yoke was carried out, and the obtained results were advantageously compared with those provided by using a commercial Boehringer test kit. PMID:11305650

  19. An Algebra of Reversible Quantum Computing

    OpenAIRE

    Wang, Yong

    2015-01-01

    Based on the axiomatization of reversible computing RACP, we generalize it to quantum reversible computing which is called qRACP. By use of the framework of quantum configuration, we show that structural reversibility and quantum state reversibility must be satisfied simultaneously in quantum reversible computation. RACP and qRACP has the same axiomatization modulo the so-called quantum forward-reverse bisimularity, that is, classical reversible computing and quantum reversible computing are ...

  20. Towards a Reversible Functional Language

    DEFF Research Database (Denmark)

    Yokoyama, Tetsuo; Axelsen, Holger Bock; Glück, Robert

    2011-01-01

    /equality operator also simplifies inverse computation and program inversion. We discuss the advantages of a reversible functional language using example programs, including run-length encoding. Program inversion is seen to be as lightweight as for imperative reversible languages and realized by recursive descent......We identify concepts of reversibility for a functional language by means of a set of semantic rules with specific properties. These properties include injectivity along with local backward determinism, an important operational property for an efficient reversible language. We define a concise...... reversible first-order functional language in which access to the backward semantics is provided to the programmer by inverse function calls. Reversibility guarantees that in this language a backward run (inverse interpretation) is as fast as the corresponding forward run itself. By adopting a symmetric...

  1. 油包水微乳液中抗体酶催化布洛芬酯选择性水解的酶学特性%Enzymological Characteristics of Catalytic Antibody-catalyzed enantioselective Hydrolysis of Ibuprofen Ester in Water-in-oil microemulsion

    Institute of Scientific and Technical Information of China (English)

    杨根生; 戚映丹; 欧志敏; 姚善泾

    2009-01-01

    The asymmetric hydrolyzation of racemic ibuprofen ester is one of the most important methods for chiral separation of ibuprofen. A catalytic antibody that accelerates the rate of enantioselective hydrolysis of ibuprofen methyl ester was successfully elicited against an immunogen consisting of tetrahedral sulfate hapten attached to bovine serum albumin (BSA). The rate constant enhancement factor Kcat/Kuncat was about 1.6x104. The catalytic activity of the catalytic antibody in a reverse micelle reaction system based on sodium b/s (2-ethylhexyl) sodium sulfosuccinate (AOT) in isooctane was studied. Kinetic analysis of the catalytic antibody-catalyzed reaction was found to be possible in this system. Kinetic studies showed that hydrolysis in the microemulsion system follow Michaelis-Menten kinetics. The catalytic antibody can also accelerate catalysis of S-ibuprofen methyl ester in the microemulsion system. Temperature effects, the pH profile, Km,app and Kcat were determined. The dependence of the catalytic antibody hydrolytic activity on the Wo (molar ratio of water to surfactant) showed a bell-shaped curve, presenting a maximum at about wo = 21.%根据过渡态理论设计和合成了能诱导产生催化选择性水解布洛芬甲酯的催化抗体的四面体硫酸盐半抗原,并与牛血清白蛋白(BSA)偶联制备成免疫源,通过免疫手段成功筛选出具有加速选择性水解生成S-布洛芬的特异性催化抗体.其Kcat,app/Kuncat,app达1.6x104.进一步地将催化抗体运用到W/O微乳体系(反胶束)中进行布洛芬酯的选择性水解研究,其动力学研究证明其催化过程同样遵循Michaelis.Menten方程.考察了pH值和温度对催化初速度影响,Wo(体系中水和琥珀酸二辛酯磺酸钠(AOT)的摩尔比)对催化初速度影响呈现为钟罩型,最适的Wo.为21.

  2. Company policy toward reverse logistics

    OpenAIRE

    Klapalová Alena; Králová Maria

    2012-01-01

    The paper deals with the results of questionnaire survey examining the character of companies’ policies towards management of reverse flows logistics, namely innovativeness of policy related to the reasons of involvement to manage reverse flows and to the planning system of reverse logistics. Answers from the informants and respondents from 150 Czech companies were analysed with the employment of statistical methods (frequencies, contingency tables and Man – Whitney test) to explore the poten...

  3. Geomagnetic Reversals during the Phanerozoic.

    Science.gov (United States)

    McElhinny, M W

    1971-04-01

    An antalysis of worldwide paleomagnetic measurements suggests a periodicity of 350 x 10(6) years in the polarity of the geomagnetic field. During the Mesozoic it is predominantly normal, whereas during the Upper Paleozoic it is predominantly reversed. Although geomagnetic reversals occur at different rates throughout the Phanerozoic, there appeaars to be no clear correlation between biological evolutionary rates and reversal frequency. PMID:17735224

  4. Magnetic reversals and mass extinctions

    Science.gov (United States)

    Raup, D. M.

    1985-01-01

    The results of a study of reversals of the earth's magnetic field over the past 165 Myr are presented. A stationary periodicity of 30 Myr emerges which predicts pulses of increased reversal activity centered at 10, 40, 70, . . . Myr before the present. The correlation between the reversal intensity and biological extinctions is examined, and a nontrivial discrepancy is found between the magnetic and extinction periodicity.

  5. Magnetic Reversal on Vicinal Surfaces

    OpenAIRE

    Hyman, R. A.; Zangwill, A.; Stiles, M. D.

    1998-01-01

    We present a theoretical study of in-plane magnetization reversal for vicinal ultrathin films using a one-dimensional micromagnetic model with nearest-neighbor exchange, four-fold anisotropy at all sites, and two-fold anisotropy at step edges. A detailed "phase diagram" is presented that catalogs the possible shapes of hysteresis loops and reversal mechanisms as a function of step anisotropy strength and vicinal terrace length. The steps generically nucleate magnetization reversal and pin the...

  6. 49 CFR 230.89 - Reverse gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Reverse gear. 230.89 Section 230.89 Transportation... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants... quadrant. Proper counterbalance shall be provided for the valve gear. (b) Air-operated power reverse...

  7. ASYMMETRIC SOLAR POLAR FIELD REVERSALS

    International Nuclear Information System (INIS)

    The solar polar fields reverse because magnetic flux from decaying sunspots moves toward the poles, with a preponderance of flux from the trailing spots. If there is a strong asymmetry, in the sense that most activity is in the northern hemisphere, then that excess flux will move toward the north pole and reverse that pole first. If there is more activity in the south later on, then that flux will help to reverse the south pole. In this way, two humps in the solar activity and a corresponding difference in the time of reversals develop (in the ideal case). Such a difference was originally noted in the very first observation of polar field reversal just after the maximum of the strongly asymmetric solar cycle 19, when the southern hemisphere was most active before sunspot maximum and the south pole duly reversed first, followed by the northern hemisphere more than a year later, when that hemisphere became most active. Solar cycles since then have had the opposite asymmetry, with the northern hemisphere being most active before solar maximum. We show that polar field reversals for these cycles have all happened in the north first, as expected. This is especially noteworthy for the present solar cycle 24. We suggest that the association of two or more peaks of solar activity when separated by hemispheres with correspondingly different times of polar field reversals is a general feature of the cycle, and that asymmetric polar field reversals are simply a consequence of the asymmetry of solar activity.

  8. Initiation of HIV Reverse Transcription

    Directory of Open Access Journals (Sweden)

    Roland Marquet

    2010-01-01

    Full Text Available Reverse transcription of retroviral genomes into double stranded DNA is a key event for viral replication. The very first stage of HIV reverse transcription, the initiation step, involves viral and cellular partners that are selectively packaged into the viral particle, leading to an RNA/protein complex with very specific structural and functional features, some of which being, in the case of HIV-1, linked to particular isolates. Recent understanding of the tight spatio-temporal regulation of reverse transcription and its importance for viral infectivity further points toward reverse transcription and potentially its initiation step as an important drug target.

  9. REVERSE LOGISTICS OF ELECTRONICS WASTE

    Directory of Open Access Journals (Sweden)

    ADRIANO NICOLAU SELPIS

    2012-07-01

    Full Text Available The growing demand for electronics equipment, its fast obsolescence, lack of oversight and legislation of its final destination, has contributed them to be discarted in common junk. Electronic equipments and their parts such as computers, TVs, cell phones, refrigerators, batteries, among others, contains highly toxic heavy metals such as mercury, cadmium, arsenic, copper, lead, and others, that if they are burned, pollute the air, besides being potential risk to the health of the garbage collectors, and also, when being in contact with the ground, they can pollute the water table, plants, animals, and consequently affect the human health. Based on research conducted by the analytical-descriptive method, we tried to link the the main threats to the environment and health that the incorrect disposal of waste electronics may represent, as well as identify and present some actions to minimize this impact. It was concluded that the main factors that contribute to the indiscriminate disposal of waste electronics are the lack of legislation to responsibility the manufacturers, strict supervision, tax incentives for the practice of reverse logistics, technology for sophisticated components recycling and environmental education.

  10. Decontamination of Tritiated-Water Using Super-hydrophobic Pt-Catalyst Synthesized with Water-in-Supercritical CO2

    International Nuclear Information System (INIS)

    . As the second approach, we utilize CO2 soluble Pt precursor, CODMe2Pt purchased from Sigma-Aldrich Co. and H2 gas as reducing agent, which could be completely mixed with SC-CO2. This system was well-known for Pt particle formation by auto-catalytic growth. The second approach was aiming at increasing Pt amount deposited in the gauze. This approach was successful in increasing Pt amount, but the Pt particle size also increased to be more than 50 nm, which was not suitable for catalyst. Finally, we synthesized the catalyst by the following procedure: firstly, a reducing agent of NaBH4 was deposited on the nano-textured hydrophobic layer on the gauze. This step was realized by forming reversed micelles of aqueous NaBH4 solution using a surfactant AOT and a co-surfactant 2,2,3,3,4,4,5,5,-octafluoro-1-pentanol (F-pentanol) in SC-CO2. This system of surfactant combination of AOT and F-pentanol has been found to work successfully in recent studies. In the second step, the gauze was contacted with CODMe2Pt dissolved in SC-CO2 to synthesize seeds of Pt particles for the auto-catalytic reaction proceeding by CODMe2Pt with hydrogen. The seeds were formed by the reaction between deposited NaBH4 and CODMe2Pt in SC-CO2. The physical characterization of this catalyst was performed by SEM-EDS. By this procedure, the Pt hydrophobic catalyst where Pt nanoparticle of 10 nm in diameter was locally deposited in the nano-textured layer was successfully prepared. Hydrophobicity after the chemical Pt deposition was tested by measurement of water absorbed on the gauze and the catalyst performance was evaluated by 1H2H formation through the scrambling reaction from 1H2 and 2H2 and the reaction was successfully observed. We demonstrated a new hydrophobic catalyst preparation using SC-CO2 effectively. We can conclude that the approach of creating Pt nanoparticles in SC-CO2 and depositing them in the super-hydrophobic structure on the metal surface is useful for synthesizing hydrophilic

  11. A Reversible Processor Architecture and its Reversible Logic Design

    DEFF Research Database (Denmark)

    Thomsen, Michael Kirkedal; Axelsen, Holger Bock; Glück, Robert

    2012-01-01

    We describe the design of a purely reversible computing architecture, Bob, and its instruction set, BobISA. The special features of the design include a simple, yet expressive, locally-invertible instruction set, and fully reversible control logic and address calculation. We have designed an arch...

  12. Liquid and solid waste reduction by using Reversed Osmose

    International Nuclear Information System (INIS)

    Full text of publication follows: Radioactive waste water produced at the NRG site in Petten is treated in our waste water treatment facility by membrane filtration and by the use of flocculant to reduce the amount of liquid waste. By using a flocculant a quite amount of sludge as secondary waste is produced. To reduce the amount of solid secondary waste tests have been performed with reversed osmosis. The effect of reverse osmoses was tested on: - different types of waste; - different concentrations of heavy metals such as Cr, Co, Ni, Cu, Zn, As, Cd, Sn, Hg, Pb...; - Kjiedahl nitrogen; - chemical oxygen demand. It was shown in the experiments with different original waste waters that for the greater part of waste streams a radionuclide concentration reduction of 90%-100% can be achieved. The reduction of nitrogen and oxygen is in the range of 65%-100% depending on the waste steam type. The introduction of reversed osmoses resulted in three advantages: - The amount of flocculant that has to be used can be reduced up to 50%. - It becomes possible to re-use waste water in certain cleaning processes which was not possible before the use of reversed osmoses. - The water which is released is much cleaner than without the use of reversed osmoses. (authors)

  13. Design of Reversible Sequential Circuit Using Reversible Logic Synthesis

    Directory of Open Access Journals (Sweden)

    Md. Mosharof Hossin

    2012-01-01

    Full Text Available Reversible logic is one of the most vital issue at present time and it has different areas for its application, those are low power CMOS, quantum computing, nanotechnology, cryptography, optical computing, DNA computing, digital signal processing (DSP, quantum dot cellular automata, communication, computer graphics. It is not possible to realize quantum computing without implementation of reversible logic. The main purposes of designing reversible logic are to decrease quantum cost, depth of the circuits and the number of garbage outputs. In this paper, we have proposed a new reversible gate. And we have designedRS flip flop and D flip flop by using our proposed gate and Peres gate. The proposed designs are better than the existing proposed ones in terms of number of reversible gates and garbage outputs. So, this realization is more efficient and less costly than other realizations.

  14. Design of Reversible Sequential Circuit Using Reversible Logic Synthesis

    Directory of Open Access Journals (Sweden)

    Md. Belayet Ali

    2011-12-01

    Full Text Available Reversible logic is one of the most vital issue at present time and it has different areas for its application,those are low power CMOS, quantum computing, nanotechnology, cryptography, optical computing, DNA computing, digital signal processing (DSP, quantum dot cellular auto meta, communication, computer graphics. It is not possible to realize quantum computing without implementation of reversible logic. The main purposes of designing reversible logic are to decrease quantum cost, depth of the circuits and the number of garbage outputs. In this paper, we have proposed a new reversible gate. And we have designed RS flip flop and D flip flop by using our proposed gate and Peres gate. The proposed designs are better than the existing proposed ones in terms of number of reversible gates and garbage outputs. So, this realization is more efficient and less costly than other realizations.

  15. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centers the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFC's with a major radius R = 2-6 cm, minor radius a approximately 2 cm, and a total length l approximately 35 cm. The observed temperatures are T/sub e/ approximately 100 eV and T/sub i/ = 150-350 eV with a peak density n approximately 2 x 1015 cm-3. After the plasma reaches equilibrium, the RFC remains stable for up to 30 μs followed by the rapid growth of the rotational m = 2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behavior of the m = 2 mode qualitatively agrees with the theoretically predicted instability for rotational velocities exceeding some critical value

  16. Driving forward in reverse

    International Nuclear Information System (INIS)

    We describe the use of TILLING in Lotus japonicus and the development of deletion (De)-TILLING in Medicago truncatula. The evolution of RevGenUK has been driven by the development of reverse genetics technologies in these two model legumes and Brassica rapa, which functions as a translational species for brassica crops. TILLING and De-TILLING, are underpinned by populations of plants mutagenised with either EMS (that causes point mutations) or fast neutrons (that cause deletions) respectively. They permit the isolation of either allelic series of mutants or knockouts. Mutation detection will be developed from a number of independent gel-based systems to be carried out on a single platform - capillary electrophoresis. We are currently TILLING in both model legumes, but these developments will be applied to all three species. The resource will develop an open source database-driven system to support laboratory information management, analysis and the cataloguing of mutants in a genome context across all the species. (author)

  17. Field reversal experiments (FRX)

    International Nuclear Information System (INIS)

    The equilibrium, confinement, and stability properties of the reversed-field configuration (RFC) are being studied in two theta-pinch facilities. The RFC is an elongated toroidal plasma confined in a purely poloidal field geometry. The open field lines of the linear theta pinch support the closed-field RFC much like the vertical field centres the toroidal plasma in a tokamak. Depending on stability and confinement properties, the RFC might be used to greatly reduce the axial losses in linear fusion devices such as mirrors, theta pinches, and liners. The FRX systems produce RFCs with a major radius R=2-6cm, a minor radius a approximately 2cm, and a total length l approximately 35cm. The observed temperatures are Tsub(e) approximately 100eV and Tsub(i)=150-350eV with a peak density n approximately 2x1015cm-3. After the plasma has reached equilibrium, the RFC remains stable for up to 30μs, followed by the rapid growth of the rotational m=2 instability, which terminates the confinement. During the stable equilibrium, the particle and energy confinement times are more than 10 times longer than in an open-field system. The behaviour of the m=2 mode agrees qualitatively with the theoretically predicted instability for rotational velocities exceeding some critical value. (author)

  18. Reversible micromachining locator

    Science.gov (United States)

    Salzer, L.J.; Foreman, L.R.

    1999-08-31

    This invention provides a device which includes a locator, a kinematic mount positioned on a conventional tooling machine, a part carrier disposed on the locator and a retainer ring. The locator has disposed therein a plurality of steel balls, placed in an equidistant position circumferentially around the locator. The kinematic mount includes a plurality of magnets which are in registry with the steel balls on the locator. In operation, a blank part to be machined is placed between a surface of a locator and the retainer ring (fitting within the part carrier). When the locator (with a blank part to be machined) is coupled to the kinematic mount, the part is thus exposed for the desired machining process. Because the locator is removably attachable to the kinematic mount, it can easily be removed from the mount, reversed, and reinserted onto the mount for additional machining. Further, the locator can likewise be removed from the mount and placed onto another tooling machine having a properly aligned kinematic mount. Because of the unique design and use of magnetic forces of the present invention, positioning errors of less than 0.25 micrometer for each machining process can be achieved. 7 figs.

  19. Driving Forward in Reverse

    International Nuclear Information System (INIS)

    We describe the use of TILLING in Lotus japonicus and the development of deletion (De)-TILLING in Medicago truncatula. The evolution of RevGen UK has been driven by the development of reverse genetics technologies in these two model legumes and Brassica rapa, which functions as a translational species for brassica crops. TILLING and De-TILLING are underpinned by populations of plants mutagenized with either EMS (that causes point mutations) or fast neutrons (that cause deletions), respectively. They permit the isolation of either allelic series of mutants or knockouts. Mutation detection will be developed from a number of independent gel-based systems to be carried out on a single platform - capillary electrophoresis. We are currently TILLING in both model legumes, but these developments will be applied to all three species. The resource will develop an open source database-driven system to support laboratory information management, analysis and the cataloguing of mutants in a genome context across all the species. (author)

  20. A novel hybrid process of reverse electrodialysis and reverse osmosis for low energy seawater desalination and brine management

    OpenAIRE

    Li, Y.; Krantz, B; Cornelissen, R; Post, W.; Verliefde, A.R.D.; Tang, Y.

    2013-01-01

    This paper introduces a novel concept for a hybrid desalination system that combines reverse electrodialysis (RED) and reverse osmosis (RO) processes. In this hybrid process the RED unit harvests the energy in the form of electricity from the salinity gradient between a highly concentrated solution (e.g., seawater or concentrated brine) and a low salinity solution (e.g., biologically treated secondary effluent or impaired water). The RED-treated high salinity solution has a lower salt concent...

  1. Technology of field reversed pinch

    International Nuclear Information System (INIS)

    This paper presents a review of field-reversed pinch technology. It covers the basic design requirements for various components involved in a field-reversed pinch device, such as circuit, switch, triggering system, transmission line, load assembly and power supply. Precautions against electric interferences are also mentioned

  2. Parkinson's disease managing reversible neurodegeneration.

    Science.gov (United States)

    Hinz, Marty; Stein, Alvin; Cole, Ted; McDougall, Beth; Westaway, Mark

    2016-01-01

    Traditionally, the Parkinson's disease (PD) symptom course has been classified as an irreversible progressive neurodegenerative disease. This paper documents 29 PD and treatment-induced systemic depletion etiologies which cause and/or exacerbate the seven novel primary relative nutritional deficiencies associated with PD. These reversible relative nutritional deficiencies (RNDs) may facilitate and accelerate irreversible progressive neurodegeneration, while other reversible RNDs may induce previously undocumented reversible pseudo-neurodegeneration that is hiding in plain sight since the symptoms are identical to the symptoms being experienced by the PD patient. Documented herein is a novel nutritional approach for reversible processes management which may slow or halt irreversible progressive neurodegenerative disease and correct reversible RNDs whose symptoms are identical to the patient's PD symptoms. PMID:27103805

  3. Fundamentals of reversible flowchart languages

    DEFF Research Database (Denmark)

    Yokoyama, Tetsuo; Axelsen, Holger Bock; Glück, Robert

    2016-01-01

    Abstract This paper presents the fundamentals of reversible flowcharts. They are intended to naturally represent the structure and control flow of reversible (imperative) programming languages in a simple computation model, in the same way classical flowcharts do for conventional languages......, structured reversible flowcharts are as expressive as unstructured ones, as shown by a reversible version of the classic Structured Program Theorem. We illustrate how reversible flowcharts can be concretized with two example programming languages, complete with syntax and semantics: a low-level unstructured...... language and a high-level structured language. We introduce concrete tools such as program inverters and translators for both languages, which follow the structure suggested by the flowchart model. To further illustrate the different concepts and tools brought together in this paper, we present two major...

  4. 普通反渗透复合膜处理高含盐量高硬度苦咸水实验研究%Experimental Study on Processing Blackish Water with High Salinity and High Hardness by Ordinary Reverse Osmosis Composite Membrane

    Institute of Scientific and Technical Information of China (English)

    李旭; 武福平

    2011-01-01

    According to the characteristics of groundwater with high hardness and salinity along Nanjiang railway,desalination experiments of blackish water were carried out by using BW30. 4040 ordinary reverse osmosis membrane. The effects of the desalination tine and the temperature of blackish water as well as the pressure on the separation performance and stability of reverse osmosis membrane were investigated. The best operation parameter has been determined,namely,recovery rate is 40~60%, operating pressure is 1. 3 ~1. 6 Mpa and temperature is 10~25 ℃. The results show that it is reasonable and effective to desalinate the high concentration blackish water with ordinary reverse osmosis composite membrane.%针对南疆铁路沿线地下水极高硬度及含盐量的水质特征,实验考察了采用普通反渗透复合膜处理其水质的可行性,考察了该膜的分离性能随操作压力、温度、运行时间等变化的影响及膜的运行稳定性,确定了最佳运行条件,即:回收率为:40%~60%,操作压力1.3~1.6 MPa,温度10~25℃.结果表明:采用普通反渗透复合膜来处理高含盐量高硬度苦咸水是可行的也是有效的.

  5. Reversed polarity patches at the CMB and geomagnetic field reversal

    Institute of Scientific and Technical Information of China (English)

    XU; Wenyao(徐文耀); WEI; Zigang(魏自刚)

    2002-01-01

    The International Geomagnetic Reference Field models (IGRF) for 1900-2000 are used to calculate the geomagnetic field distribution in the Earth' interior from the ground surface to the core-mantle boundary (CMB) under the assumption of insulated mantle. Four reversed polarity patches, as one of the most important features of the CMB field, are revealed. Two patches with +Z polarity (downward) at the southern African and the southern American regions stand out against the background of -Z polarity (upward) in the southern hemisphere, and two patches of -Z polarity at the North Polar and the northern Pacific regions stand out against the +Z background in the northern hemisphere. During the 1900-2000 period the southern African (SAF) patch has quickly drifted westward at a speed of 0.2-0.3°/a; meanwhile its area has expanded 5 times, and the magnetic flux crossing the area has intensified 30 times. On the other hand, other three patches show little if any change during this 100-year period. Extending upward, each of the reversed polarity patches at the CMB forms a chimney-shaped "reversed polarity column" in the mantle with the bottom at the CMB. The height of the SAF column has grown rapidly from 200km in 1900 to 900km in 2000. If the column grows steadily at the same rate in the future, its top will reach to the ground surface in 600-700 years. And then a reversed polarity patch will be observed at the Earth's surface, which will be an indicator of the beginning of a magnetic field reversal. On the basis of this study, one can describe the process of a geomagnetic polarity reversal, the polarity reversal may be observed firstly in one or several local regions; then the areas of these regions expand, and at the same time, other new reversed polarity regions may appear. Thus several poles may exist during a polarity reversal.

  6. Reversible computing and cellular automata - A survey

    OpenAIRE

    Morita, Kenichi

    2008-01-01

    Reversible computing is a paradigm where computing models are defined so that they reflect physical reversibility, one of the fundamental microscopic physical property of Nature. In this survey/tutorial paper, we discuss how computation can be carried out in a reversible system, how a universal reversible computer can be constructed by reversible logic elements, and how such logic elements are related to reversible physical phenomena. We shall see that, in reversible systems, computation can ...

  7. Boron Removal in Seawater Reverse Osmosis System

    KAUST Repository

    Rahmawati, Karina

    2011-07-01

    Reverse osmosis successfully proves to remove more than 99% of solute in seawater, providing fresh water supply with satisfied quality. Due to some operational constraints, however, some trace contaminants removal, such as boron, cannot be achieved in one pass system. The stringent criterion for boron from World Health Organization (WHO) and Saudi Arabia local standard (0.5 mg/l) is hardly fulfilled by single pass sea water reverse osmosis (SWRO) plants. Some design processes have been proposed to deal with boron removal, but they are not economically efficient due to high energy and chemical consumption. The objective of this study was to study boron removal by different reverse osmosis membranes in two pH conditions, with and without antiscalant addition. Thus, it was expected to observe the possibility of operating single pass system and necessity to operate two pass system using low energy membrane. Five membrane samples were obtained from two different manufacturers. Three types of feed water pH were used, pH 8, pH 10, and pH 10 with antiscalant addition. Experiment was conducted in parallel to compare membrane performance from two manufacturers. Filtration was run with fully recycle mode for three days. Sample of permeate and feed were taken every 12 hours, and analyzed for their boron and TDS concentration. Membrane samples were also tested for their surface charge. The results showed that boron rejection increases as the feed pH increases. This was caused by dissociation of boric acid to negatively charged borate ion and more negatively charged membrane surface at elevated pH which enhance boron rejection. This study found that single pass reverse osmosis system, with and without elevating the pH, may not be possible to be applied because of two reasons. First, permeate quality in term of boron, does not fulfill WHO and local Saudi Arabia regulations. Second, severe scaling occurs due to operation in alkaline condition, since Ca and Mg concentration are

  8. Reverse engineering for quality systems

    International Nuclear Information System (INIS)

    When the age of software engineering began, many companies were faced with a problem of how to support the older, pre-software-engineering, programs. The techniques of reverse engineering and re-engineering were developed to bridge the gap between the past and the present. Although reverse engineering can be used for generating missing documentation, it can also be used as a means to demonstrate quality in these older programs. This paper presents, in the form of a case study, how Rolls-Royce and Associates Limited addressed the quality issues of reverse engineering and re-engineering. (author)

  9. Development of reversible strain gage

    International Nuclear Information System (INIS)

    A high-temperature strain gage which can be peeled after taking required apparent strain measurements in a furnace and can be attached reverse-side-up at the point of interest on a test structure was developed. Using the ''reversible'' strain gage with selected room-temperature curing type polyester adhesive, one can expect to measure thermal strain accurately, especially for on large structures, at the first test in temperature up to 250 deg C. The repeatability of apparent strains for about 100 reversible gages was within 50 microstrains of difference at 250 deg C (within 30 microstrains of difference for 80 % of the test gages). (author)

  10. Reverse Engineering Quantum Field Theory

    OpenAIRE

    Oeckl, Robert

    2012-01-01

    An approach to the foundations of quantum theory is advertised that proceeds by "reverse engineering" quantum field theory. As a concrete instance of this approach, the general boundary formulation of quantum theory is outlined.

  11. An Overview of Reverse Logistics

    Institute of Scientific and Technical Information of China (English)

    WANG Jia-xiang; HE Xin

    2005-01-01

    Until recently, investment in logistics has focused mainly on the flows from companies to markets. Growing concerns for the environment and conserving resources have created new logistical approaches to more effectively manage the distribution function, and make better use of the resources available to an organization. One such approach is reverse logistics, which uses various methods to give scope for a back-load of finished products, components, waste, reusable packing, etc. from consumer to manufacturer. Back-loads allow manufacturers to reduce costs by using the distribution vehicle's return journey to create income or added value. This basic concept is now being developed to create novel solutions to the problems of reducing pollution, costs and vehicle movements, whilst maintaining high customer service levels. In this paper, the idea of reverse logistics is presented; motivations for it are analyzed, several successful practices are demonstrated and some important truths regarding successful reverse logistics are identified, trend of reverse logistics is provided.

  12. Reverse Knowledge Transfer in MNEs

    DEFF Research Database (Denmark)

    Mudambi, Ram; Piscitello, Lucia; Rabbiosi, Larissa

    2014-01-01

    positive correlation with the extent of reverse knowledge transfers to the parent MNE. Relying on the headquarters-subsidiary view of the MNE, we argue that, beyond a point, increasing subsidiary innovativeness will be associated with lower reverse knowledge transfers. Further, we argue that this...... relationship is sensitive to the subsidiary entry mode. Using data from a sample of 293 Italian subsidiaries, we find strong support for our hypotheses. In particular, our results confirm that the effect of subsidiary innovativeness on reverse knowledge transfers displays an inverted-U shape, and that the...... curvilinearity is greater for greenfield entries relative to acquisition entries. The U-shaped relationship between subsidiary innovativeness and reverse knowledge transfers, as well as the sensitivity of this result to entry mode are important new findings in the literature on the role of subsidiaries in...

  13. Designing the Reverse Supply Chain

    DEFF Research Database (Denmark)

    Gobbi, Chiara

    2011-01-01

    supply chain. Research limitations/implications – The focus is restricted to the industry of electrical and electronic products. Practical implications – Based on the outcome of the study, managers are able to determine the basic prerequisites for the design of their reverse supply chains. Originality......Purpose – The purpose of this paper is to explore the impact of the product residual value (PRV) and the loss of value over time of returned products in the reverse supply chain configuration. It also examines whether or not the distinction of Fisher's functional and innovative products holds for...... the reverse supply chain. Design/methodology/approach – In order to identify the relevance of the Fisher model, the model needs to be recast in terms of PRV, which, in this context, is considered the independent variable in the reverse logistics arena. Products defined as innovative in Fisher...

  14. A Typology of Reverse Innovation

    DEFF Research Database (Denmark)

    von Zedtwitz, Max; Corsi, Simone; Søberg, Peder Veng;

    2015-01-01

    Reverse innovation commonly refers to an innovation initially launched in a developing country and later introduced to an advanced country. Adopting a linear innovation model with the four sequential phases of concept ideation, product development, primary target market introduction, and subsequent...... secondary market introduction, this study expands the espoused definition of reverse innovation beyond its market-introduction focus with reversals in the flow of innovation in the ideation and product development phases. Recognizing that each phase can take place in different geographical locations, the...... taking place in an emerging country. This analytical framework allows recasting of current research at the intersection between innovation and international business. Of the 10 reverse innovation flows, six are new and have not been covered in the literature to date. The study addresses questions of...

  15. Liquid-liquid extraction by reversed micelles in biotechnological processes

    Directory of Open Access Journals (Sweden)

    Kilikian B. V.

    2000-01-01

    Full Text Available In biotechnology there is a need for new purification and concentration processes for biologically active compounds such as proteins, enzymes, nucleic acids, or cells that combine a high selectivity and biocompatibility with an easy scale-up. A liquid-liquid extraction with a reversed micellar phase might serve these purposes owing to its capacity to solubilize specific biomolecules from dilute aqueous solutions such as fermentation and cell culture media. Reversed micelles are aggregates of surfactant molecules containing an inner core of water molecules, dispersed in a continuous organic solvent medium. These reversed micelles are capable of selectively solubilizing polar compounds in an apolar solvent. This review gives an overview of liquid-liquid extraction by reversed micelles for a better understanding of this process.

  16. Proceedings of the Interdisciplinary colloquium on reversibility

    International Nuclear Information System (INIS)

    This document contains the contributions to a colloquium, presented either in full text or as Power Point presentations. After an opening speech on decision reversibility of waste retrieval, the contributions respectively addressed: The charge taking ability, Proving and demonstrating reversibility, The issue of reversibility in an evolutional system in the case of CO2 geological disposal, Interactions between reversibility and disposal safety, Reversible disposal of radioactive wastes, Reversibility and retrievability within debates on decision-making about nuclear wastes in Finland and United Kingdom, The political qualities of technologies (irreversibility and reversibility in nuclear waste management), The contribution of economic analysis to the reversibility of nuclear waste disposal, The economic cost of reversibility, The appropriation of the notion of reversibility by the Andra, Arguments about the notion of reversibility, The notion of reversibility as a political symbol or actual concern, The project of document space 'ExploRe' (opened pluri-disciplinary exploration of reversibility), The participatory documentarisation at the service of reversibility. Posters addressed the following topics: Andra and reversibility, Reversibility, operational safety and long term safety in geological disposal, Andra's R and D in relationship the monitoring and survey of reversible disposal installations, Numerical simulation for the prediction and the analysis of disposal operation and aid-to-decision for its management, Demand of reversibility with respect to disposal progressive development, Taking reversibility into account for the complementarity between warehousing and storage

  17. Automated Water-Purification System

    Science.gov (United States)

    Ahlstrom, Harlow G.; Hames, Peter S.; Menninger, Fredrick J.

    1988-01-01

    Reverse-osmosis system operates and maintains itself with minimal human attention, using programmable controller. In purifier, membranes surround hollow cores through which clean product water flows out of reverse-osmosis unit. No chemical reactions or phase changes involved. Reject water, in which dissolved solids concentrated, emerges from outer membrane material on same side water entered. Flow controls maintain ratio of 50 percent product water and 50 percent reject water. Membranes expected to last from 3 to 15 years.

  18. Laparoscopic reversal of Hartmann's procedure

    DEFF Research Database (Denmark)

    Svenningsen, Peter Olsen; Bulut, Orhan; Jess, Per

    2010-01-01

    A change in procedure from open to laparoscopic reversal of Hartmann's colostomy was implemented at our department between May 2005 and December 2008. The aim of the study was to investigate if this change was beneficial for the patients.......A change in procedure from open to laparoscopic reversal of Hartmann's colostomy was implemented at our department between May 2005 and December 2008. The aim of the study was to investigate if this change was beneficial for the patients....

  19. The multidimensional reverse Hardy inequalities

    Czech Academy of Sciences Publication Activity Database

    Gogatishvili, Amiran; Mustafayev, Rza

    2012-01-01

    Roč. 15, č. 1 (2012), s. 1-14. ISSN 1331-4343 R&D Projects: GA ČR GA201/08/0383 Institutional research plan: CEZ:AV0Z10190503 Keywords : multidimensional Hardy operator * Hardy inequality * reverse Hardy inequality Subject RIV: BA - General Math ematics Impact factor: 0.588, year: 2012 http://mia.ele- math .com/15-01/The-multidimensional-reverse-Hardy-inequalities

  20. Deciphering records of geomagnetic reversals

    Science.gov (United States)

    Valet, Jean-Pierre; Fournier, Alexandre

    2016-06-01

    Polarity reversals of the geomagnetic field are a major feature of the Earth's dynamo. Questions remain regarding the dynamical processes that give rise to reversals and the properties of the geomagnetic field during a polarity transition. A large number of paleomagnetic reversal records have been acquired during the past 50 years in order to better constrain the structure and geometry of the transitional field. In addition, over the past two decades, numerical dynamo simulations have also provided insights into the reversal mechanism. Yet despite the large paleomagnetic database, controversial interpretations of records of the transitional field persist; they result from two characteristics inherent to all reversals, both of which are detrimental to an ambiguous analysis. On the one hand, the reversal process is rapid and requires adequate temporal resolution. On the other hand, weak field intensities during a reversal can affect the fidelity of magnetic recording in sedimentary records. This paper is aimed at reviewing critically the main reversal features derived from paleomagnetic records and at analyzing some of these features in light of numerical simulations. We discuss in detail the fidelity of the signal extracted from paleomagnetic records and pay special attention to their resolution with respect to the timing and mechanisms involved in the magnetization process. Records from marine sediments dominate the database. They give rise to transitional field models that often lead to overinterpret the data. Consequently, we attempt to separate robust results (and their subsequent interpretations) from those that do not stand on a strong observational footing. Finally, we discuss new avenues that should favor progress to better characterize and understand transitional field behavior.

  1. Vasectomy reversal: a clinical update

    OpenAIRE

    Patel, Abhishek P; Smith, Ryan P.

    2016-01-01

    textabstractVasectomy is a safe and effective method of contraception used by 42-60 million men worldwide. Approximately 3%-6% of men opt for a vasectomy reversal due to the death of a child or divorce and remarriage, change in financial situation, desire for more children within the same marriage, or to alleviate the dreaded postvasectomy pain syndrome. Unlike vasectomy, vasectomy reversal is a much more technically challenging procedure that is performed only by a minority of urologists and...

  2. CEO Turnover in Reverse Splits

    OpenAIRE

    Li-Hsun Wang; Chu-Hsiung Lin; Hsien-Ming Chen

    2010-01-01

    This study examines the application of CEO turnover on reverse stock splits firms. Using Taiwanese samples, we find that non-CEO turnover firms receive negative long-term abnormal returns, and their financial performances continue to decline following reverse splits. These findings are consistent with prior studies. Contrarily, neither significantly negative long-term abnormal returns nor changes on financial performance were found for CEO turnover firms. This study concludes that applying CE...

  3. Reversals of the solar dipole

    OpenAIRE

    Moss, David; Kitchatinov, Leonid L.; Sokoloff, Dmitri

    2012-01-01

    During a solar magnetic field reversal the magnetic dipole moment does not vanish, but migrates between poles, in contradiction to the predictions of mean-field dynamo theory. We try to explain this as a consequence of magnetic fluctuations. We exploit the statistics of fluctuations to estimate observable signatures. Simple statistical estimates, taken with results from mean-field dynamo theory, suggest that a non-zero dipole moment may persist through a global field reversal. Fluctuations in...

  4. A study on Reverse Osmosis Concentrated Water of Petrochemical Enterprises Treated by Zeolite Loading TiO2%沸石负载型TiO2处理炼化反渗透浓缩水的研究

    Institute of Scientific and Technical Information of China (English)

    李进辉; 丁慧; 张秀霞; 刘娜; 黄文升

    2013-01-01

    This paper studies zeolite loading titanium dioxide which is used to deal with reverse osmosis concentrated water of petrochemical enterprises. Besides it researches the performance of the catalyst on concentrated water and analyzes the factors which affect the degradation. The study shows that: the degradation rate of TOC in reverse osmosis titanium dioxide concentrated water can reach 67.4% and the best conditions of degradation are as follows: the pH value of 4 to 6, temperature of 30℃ to 40℃, illumination time of 2. 5 h, and catalyst dosage of 1. 5g/L. The experiment provides a new basis for the development of concentrated water treatment technology.%利用沸石负载型二氧化钛对炼化企业的反渗透浓缩水进行研究,考察了催化剂对浓缩水的处理效果及影响降解的因素.由实验结果可知:沸石负载型二氧化钛对反渗透浓缩水TOC降解率达到67.4%,降解浓缩水的最佳条件为.pH值为4~6,温度30~40℃,光照时间2.5h,催化剂投加量为1.5g/L.实验为浓缩水处理技术的发展提供了新的依据.

  5. Garbage collection for reversible functional languages

    DEFF Research Database (Denmark)

    Mogensen, Torben Ægidius

    2015-01-01

    Reversible languages are programming languages where all programs can run both forwards and backwards. Reversible functional languages have been proposed that use symmetric pattern matching and data construction. To be reversible, these languages require linearity: Every variable must be used...

  6. Design of High speed Low Power Reversible Vedic multiplier and Reversible Divider

    OpenAIRE

    Srikanth G Department of Electronics & Communication Engineerig, Indur Institute of Engineering & Technology, Siddipet, Medak, JNTUH University, Telangana, India.; Nasam Sai Kumar

    2014-01-01

    This paper bring out a 32X32 bit reversible Vedic multiplier using "Urdhva Tiryakabhayam" sutra meaning vertical and crosswise, is designed using reversible logic gates, which is the first of its kind. Also in this paper we propose a new reversible unsigned division circuit. This circuit is designed using reversible components like reversible parallel adder, reversible left-shift register, reversible multiplexer, reversible n-bit register with parallel load line. The reversibl...

  7. Design of Reversible Random Access Memory

    OpenAIRE

    Mamun, Md. Selim Al; Hossain, Syed Monowar

    2013-01-01

    Reversible logic has become immensely popular research area and its applications have spread in various technologies for their low power consumption. In this paper we proposed an efficient design of random access memory using reversible logic. In the way of designing the reversible random access memory we proposed a reversible decoder and a write enable reversible master slave D flip-flop. All the reversible designs are superior in terms of quantum cost, delay and garbage outputs compared to ...

  8. Biocatalysis in water-in-ionic liquid microemulsions: a case study with horseradish peroxidase.

    Science.gov (United States)

    Moniruzzaman, M; Kamiya, N; Goto, M

    2009-01-20

    In this article we report the first results on the enzymatic activity of horseradish peroxidase (HRP) microencapsulated in water-in-ionic liquid (w/IL) microemulsions using pyrogallol as the substrate. Toward this goal, the system used in this study was composed of anionic surfactant AOT (sodium bis(2-ethyl-1-hexyl)sulfosuccinate)/hydrophobic IL [C(8)mim][Tf(2)N] (1-octyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)amide)/water/1-hexanol. In this system, the catalytic activity of HRP was measured as a function of substrate concentrations, W(0) (molar ratio of water to surfactant), pH, and 1-hexanol content. The curve of the activity-W(0) profile was found to be hyperbolic for the new microemulsion. The apparent Michaelis-Menten kinetic parameters (k(cat) and K(m)) were estimated and compared to those obtained from a conventional microemulsion. Apparently, it was found that HRP-catalyzed oxidation of pyrogallol by hydrogen peroxide in IL microemulsuions is much more effective than in a conventional AOT/water/isooctane microemulsion. The stability of HRP solubilized in the newly developed w/IL microemulsions was examined, and it was found that HRP retained almost 70% of its initial activity after incubation at 28 degrees C for 30 h. PMID:19113810

  9. Investigation on Single Phase Water Reverse Flow in Inverted U-Tubes of Steam Generator under Condition of Natural Circulation%自然循环蒸汽发生器倒U型管内单相流体倒流特性研究

    Institute of Scientific and Technical Information of China (English)

    王川; 于雷

    2011-01-01

    利用RELAP5/MOD3.3程序对某压水堆单相流体自然循环工况进行建模计算,给出了典型自然循环工况下蒸汽发生器(SG)倒U型传热管内正流和倒流的流最分布,分析了产生倒流现象的原因以及发生倒流的条件及判断依据.结果表明:SG倒U型管发生倒流的条件是SG出口腔压力高于入口腔压力;传热管内流体的提升压头不足以克服流动阻力压降.对于本文描述的核动力装置,在强迫循环转自然循环过程中,如果SG水位保持正常,则较短的倒U型传热管流量下滑更快且最终发生倒流.倒U型管内倒流流体温度分布均匀,与SG二次侧温度基本相同.%Using the code RELAP5/MOD3.3 to model and calculate the natural circulation of single-phase flow for the PWR, this paper provides the distribution of forward flow and reverse flow in the inverted U-tubes of the steam generator(SG) under some typical operating conditions in the natural circulation case, and analyzes the cause, occurrence condition and judgment principle of reverse flow phenomenon. The calculation results show that the occurrence conditions for reverse flow phenomenon are that the steam generator outlet pressure is higher than the inlet pressure and gravitational pressure drop is lower than the total of frictional pressure drop and area change pressure drop. As to the nuclear power plant described in this paper,if the water level of steam generator keeps normal, the mass flux of the shorter U-tubes will drop more quickly and reverse flow will occur. The temperature distributes uniformly in U-tubes with reverse flow and it is almost identical with that of SG in secondary side.

  10. Reversals in nature and the nature of reversals

    CERN Document Server

    Stefani, F; Günther, U; Sorriso-Valvo, L; Xu, M; G\\"unther, Uwe; Gerbeth, Gunter; Sorriso-Valvo, Luca; Stefani, Frank; Xu, Mingtian

    2007-01-01

    The asymmetric shape of reversals of the Earth's magnetic field indicates a possible connection with relaxation oscillations as they were early discussed by van der Pol. A simple mean-field dynamo model with a spherically symmetric $\\alpha$ coefficient is analysed with view on this similarity, and a comparison of the time series and the phase space trajectories with those of paleomagnetic measurements is carried out. For highly supercritical dynamos a very good agreement with the data is achieved. Deviations of numerical reversal sequences from Poisson statistics are analysed and compared with paleomagnetic data. The role of the inner core is discussed in a spectral theoretical context and arguments and numerical evidence is compiled that the growth of the inner core might be important for the long term changes of the reversal rate and the occurrence of superchrons.

  11. Vasectomy reversal: a clinical update.

    Science.gov (United States)

    Patel, Abhishek P; Smith, Ryan P

    2016-01-01

    Vasectomy is a safe and effective method of contraception used by 42-60 million men worldwide. Approximately 3%-6% of men opt for a vasectomy reversal due to the death of a child or divorce and remarriage, change in financial situation, desire for more children within the same marriage, or to alleviate the dreaded postvasectomy pain syndrome. Unlike vasectomy, vasectomy reversal is a much more technically challenging procedure that is performed only by a minority of urologists and places a larger financial strain on the patient since it is usually not covered by insurance. Interest in this procedure has increased since the operating microscope became available in the 1970s, which consequently led to improved patency and pregnancy rates following the procedure. In this clinical update, we discuss patient evaluation, variables that may influence reversal success rates, factors to consider in choosing to perform vasovasostomy versus vasoepididymostomy, and the usefulness of vasectomy reversal to alleviate postvasectomy pain syndrome. We also review the use of robotics for vasectomy reversal and other novel techniques and instrumentation that have emerged in recent years to aid in the success of this surgery. PMID:26975488

  12. Low Cost Reversible Signed Comparator

    Directory of Open Access Journals (Sweden)

    Farah Sharmin

    2013-10-01

    Full Text Available Nowadays exponential advancement in reversible comp utation has lead to better fabrication and integration process. It has become very popular ove r the last few years since reversible logic circuit s dramatically reduce energy loss. It consumes less p ower by recovering bit loss from its unique input-o utput mapping. This paper presents two new gates called RC-I and RC-II to design an n-bit signed binary comparator where simulation results show that the p roposed circuit works correctly and gives significa ntly better performance than the existing counterparts. An algorithm has been presented in this paper for constructing an optimized reversible n-bit signed c omparator circuit. Moreover some lower bounds have been proposed on the quantum cost, the numbers of g ates used and the number of garbage outputs generated for designing a low cost reversible sign ed comparator. The comparative study shows that the proposed design exhibits superior performance consi dering all the efficiency parameters of reversible logic design which includes number of gates used, quantum cost, garbage output and constant inputs. This proposed design has certainly outperformed all the other existing approaches.

  13. Vasectomy reversal: a clinical update

    Directory of Open Access Journals (Sweden)

    Abhishek P Patel

    2016-01-01

    Full Text Available Vasectomy is a safe and effective method of contraception used by 42-60 million men worldwide. Approximately 3%-6% of men opt for a vasectomy reversal due to the death of a child or divorce and remarriage, change in financial situation, desire for more children within the same marriage, or to alleviate the dreaded postvasectomy pain syndrome. Unlike vasectomy, vasectomy reversal is a much more technically challenging procedure that is performed only by a minority of urologists and places a larger financial strain on the patient since it is usually not covered by insurance. Interest in this procedure has increased since the operating microscope became available in the 1970s, which consequently led to improved patency and pregnancy rates following the procedure. In this clinical update, we discuss patient evaluation, variables that may influence reversal success rates, factors to consider in choosing to perform vasovasostomy versus vasoepididymostomy, and the usefulness of vasectomy reversal to alleviate postvasectomy pain syndrome. We also review the use of robotics for vasectomy reversal and other novel techniques and instrumentation that have emerged in recent years to aid in the success of this surgery.

  14. REVERSE LOGISTICS RETAIL LEVEL RETURN

    Directory of Open Access Journals (Sweden)

    Ivona Bajor

    2014-06-01

    Full Text Available Conducting scientific research regarding reverse logistics systems includes certain difficulties. Developed logistics systems are aimed at analysing reverse logistics issues and tend to continuously detect differences and oscillations in the flow of returned products and their characteristics. Developing logistics systems, as Croatian, find reverse logistics issues, regarding product returns, significantly complex and very often these issues are not observed as issues of priority. As distributive flow, reverse logistics systems fundaments should be also based on detailed analysis. Analysis in this flow presents amounts, reasons, process flows and quality of returned items. Because of complex product evaluation on individual level, reverse logistics procedures should be implemented as a methodology individually developed for every supply chain subject. This paper presents a research of retail level returns on the Croatian market, where the analysis implicated that the majority of products in return for this level is directed from final consumers and presents noncurrent inventories of distribution chain. The paper will present conducted research regarding characteristics of returns and routing these products from the retail level.

  15. International overview of seawater desalination plant by reverse osmosis technology

    OpenAIRE

    Kangwen, Shu

    2012-01-01

    In a world faced with increased urbanization, population growth, climate change and degradation of water supplies, the importance of a reliable source of technology to provide fresh water emphasizes the importance of seawater desalination. Over the years a variety of seawater desalination methods have been developed throughout the world. The most common technologies available for desalination around the world are membrane reverse osmosis (RO), thermal distillation (TD) and electrodialysis ...

  16. Fault Testing for Reversible Circuits

    CERN Document Server

    Patel, K N; Markov, I L; Patel, Ketan N.; Hayes, John P.; Markov, Igor L.

    2004-01-01

    Applications of reversible circuits can be found in the fields of low-power computation, cryptography, communications, digital signal processing, and the emerging field of quantum computation. Furthermore, prototype circuits for low-power applications are already being fabricated in CMOS. Regardless of the eventual technology adopted, testing is sure to be an important component in any robust implementation. We consider the test set generation problem. Reversibility affects the testing problem in fundamental ways, making it significantly simpler than for the irreversible case. For example, we show that any test set that detects all single stuck-at faults in a reversible circuit also detects all multiple stuck-at faults. We present efficient test set constructions for the standard stuck-at fault model as well as the usually intractable cell-fault model. We also give a practical test set generation algorithm, based on an integer linear programming formulation, that yields test sets approximately half the size o...

  17. Ice ages and geomagnetic reversals

    Science.gov (United States)

    Wu, Patrick

    1992-01-01

    There have been speculations on the relationship between climatic cooling and polarity reversals of the earth's magnetic field during the Pleistocene. Two of the common criticisms on this relationship have been the reality of these short duration geomagnetic events and the accuracy of their dates. Champion et al. (1988) have reviewed recent progress in this area. They identified a total of 10 short-duration polarity events in the last 1 Ma and 6 of these events have been found in volcanic rocks, which also have K-Ar dates. Supposing that the speculated relationship between climatic cooling and geomagnetic reversals actually exist, two mechanisms that assume climatic cooling causes short period magnetic reversals will be investigated. These two methods are core-mantle boundary topography and transfer of the rotational energy to the core.

  18. DNA polymerase beta reveals enhanced activity and processivity in reverse micelles.

    Science.gov (United States)

    Anarbaev, Rashid O; Rogozina, Anastasia L; Lavrik, Olga I

    2009-04-01

    Water is essential for the stability and functions of proteins and DNA. Reverse micelles are simple model systems where the structure and dynamics of water are controlled. We have estimated the size of complex reverse micelles by light scattering technique and examined the local microenvironment using fluorescein as molecular probe. The micelle size and water polarity inside reverse micelles depend on water volume fraction. We have investigated the different hydration and confinement effects on activity, processivity, and stability of mammalian DNA polymerase beta in reverse micelles. The enzyme displays high processivity on primed single-stranded M13mp19 DNA with maximal activity at 10% of water content. The processivity and activity of DNA polymerase strongly depend on the protein concentration. The enzyme reveals also the enhanced stability in the presence of template-primer and at high protein concentration. The data provide direct evidence for strong influence of microenvironment on DNA polymerase activity. PMID:19138815

  19. 反渗透和纳滤分离矿井水中营养组分和重金属离子的研究%Study on separation of nutrients and heavy metal ions from mine water by reverse osmosis and nanofiltration

    Institute of Scientific and Technical Information of China (English)

    钟常明; 王宗丽; 王汝胜; 吴坤泽

    2013-01-01

    论文选用M-RO2521超低压反渗透膜和M-N2521纳滤膜对矿井水中营养组分和重金属离子的分离效果进行了实验研究,实验考察了操作压力、温度和水回收率等因素对分离效果的影响.结果表明:反渗透膜对重金属离子及营养组分的平均截留率分别为97.5%和97%;纳滤膜对重金属离子及营养组分的平均截留率分别为92.75%和33.63%;在一定的操作条件下,组合工艺ULPRO+NF对矿井水营养组分和重金属离子的平均截留率均达97%以上,同时具有更高的水回收率.%The experimental study of mine water is conducted by a commercial ultra-low pressure reverse osmosis membrane (M-RO2521) and nanofiltration membrane (M-N2521). The effects of operating pressure, operating temperature and ratio of water callback on the performance of reverse osmosis membrane, nanofiltration membrane and combination process (ULPRO+NF) were investigated. Experiment results show that an average removal efficiency of heavy metal ions and nutrients by reverse osmosis membrane were 97.5 % and 97 % respectively; an average removal efficiency of heavy metal ions and nutrients by nanofiltration membrane were 92.75 % and 33.63 % respectively; however, an average removal efficiency of heavy metal ions and nutrients by combination process are more than 97 % and also have a higher water recovery.

  20. 电渗析组合反渗透过程处理头孢氨苄酶法母液废水的研究%Study on the treatment of waste water of the cephalexin enzymatic process by the combination process of electrodialysis and reverse osmosis

    Institute of Scientific and Technical Information of China (English)

    阮慧敏; 黄杰; 李健; 沈江南; 王家德; 高从堦

    2014-01-01

    利用电渗析技术脱除头孢氨苄酶法母液废水中的盐分,研究了操作电压、浓缩室与淡化室流速比、温度等因素对电渗析脱盐过程的影响,并研究了反渗透膜法处理脱盐母液废水的膜通量变化趋势。实验结果表明,当淡化室、浓缩室流量均为500 L/h(流速比1∶1),操作电压为25 V,温度<30℃时,电渗析在高效脱盐的同时具有理想的有机物截留率达99.50%以上,能耗3.65 kW⋅h/kg;反渗透膜法在处理脱盐母液废水时,膜通量衰减较慢,水回收率达到75.67%。实验结果表明,利用电渗析、反渗透组合工艺处理头孢氨苄酶法母液废水具有良好的可行性。%The-salt-in-the-waste-water-of-the-cephalexin-enzymatic-process-was-removed-by-electrodialysis.-The-influences-of-operating-voltage,velocity-ratio-and-temperature-on-the-desal-ination-process-were-investigated.-The-change-of-the-permeate-flux-in-the-reverse-osmosis-sepa-ration-process-was-also-studied.-The-results-showed-that-the-electrodialysis-process-performed-better-in-desalination-with-the-organic-matter-retention-rate-reaching-99.50%,the-energy-con-sumption-of-3.65-kW⋅h/kg-at-the-conditions-of-the-flow-of-500-L/h-(velocity-ratio-of-1∶1),the-operating-voltage-of-25-V-and-temperature<30℃.-During-the-reverse-osmosis-separation-pro-cess,the-decay-of-permeate-flux-was-slow-and-acceptable,and-the-water-recovery-rate-was-75.67%.-All-results-showed-that-it-was-feasible-to-treatment-the-waste-water-of-the-cephalexin-enzymatic-process-by-a-combined-process-of-electrodialysis-and-reverse-osmosis.