Sample records for residual nonaqueous phase

  1. Observation of the Dissolution from Residual Phase Multicomponent Nonaqueous Phase Liquids (United States)

    Brahma, P. P.; Harmon, T. C.


    Nonaqueous phase liquid (NAPL) subsurface contaminants (e.g., fuels, solvents) are typically complex mixtures. This work examines the impact of intra-NAPL diffusion and mixture nonideality on dissolution from multicomponent NAPL mixtures through a computational and experimental approach. Downstream concentrations are observed during the controlled dissolution of three-component residual NAPL in a three-dimensional model aquifer. These results, when compared to single-component residual NAPL results, are used to identify (1) if and when intra-NAPL interactions contribute significantly to the overall dissolution process, and (2) the role that factors, such as length scale, hydrodynamic conditions, and/or mixture ideality, play in determining (1). Model ternary mixtures were chosen to represent a range of ideality based on UNIFAC-estimated activity coefficients. In this case, tetrachloroethene (PCE), trichloroethene (TCE), and 1,1,1-trichloroethane (TCA) were selected as the ideal mixture. The mixture of PCE, TCE, and octanol was shown to exhibit significant deviations from ideality and selected to represent a nonideal mixture. Experimental results for the two mixtures are compared to each other and to analogous results from pure PCE dissolution experiments. The experimental results are further interpreted using a three-dimensional transport model subject to a boundary concentration history calculated using a ternary intra-NAPL diffusion/dissolution submodel. The combined experimental and computational findings are used to delineate conditions for which a detailed physical-chemical description of NAPL dissolution is warranted and those for which a simplified description will suffice.

  2. Carbon Tetrachloride Flow Behavior in Unsaturated Hanford Caliche Material: An Investigation of Residual Nonaqueous Phase Liquids

    International Nuclear Information System (INIS)

    Oostrom, Mart; Lenhard, Robert J.


    To obtain data that can be used to study the development of a residual NAPL saturation and to test corresponding models, a detailed transient experiment was conducted in a 170-cm long by 90-cm high by 5.5-cm wide flow cell. Fluid saturation measurements were obtained with a dual-energy gamma radiation system. The experimental conditions reflected those at the Hanford Site in Washington State, where an estimated 363-580 m3 of carbon tetrachloride was disposed to the subsurface. A key subsurface feature at the Hanford Site is a sloped Plio-Pleistocene caliche layer, which was reproduced in the experiment as a sloped lens in a medium-grained, uniform, sand matrix. The caliche contains considerable amounts of calcium carbonate and may have fluid wettability properties other than strongly water wet. A total of 800 ml of carbon tetrachloride was injected in the experimental domain at a rate of 0.5 ml min-1 from a small source area located at the surface. After apparent steady-state conditions were obtained with respect to carbon tetrachloride redistribution (i.e., the formation of residual DNAPL), saturation measurements indicate that all of the DNAPL that initially moved into the caliche, remained in this layer. This experimental result could not be reproduced with numerical multifluid flow simulations based on conventional constitutive relations between relative permeability, saturation, and fluid pressures. Water was subsequently applied to the surface at a constant rate over the full length of the caliche layer to study carbon tetrachloride displacement as a result of changing water saturations. Results show that as a result of this action, 29% of the DNAPL was removed from the caliche. However, the majority of the fluid remained in the caliche entrapped by water. Simulations with the multifluid flow simulator show that the current constitutive theory for relative permeability, saturation and capillary pressure does not describe displacement physics properly

  3. Acoustically enhanced nonaqueous phase liquid remediation in porous media (United States)

    Vogler, Eric Todd

    Groundwater contamination, caused by the presence of dense nonaqueous phase liquids (DNAPLs), remains a remediation challenge due to their low aqueous solubilities and residual phase immobility. To combat this challenge, the application of acoustic waves for remediation of water saturated porous media contaminated by DNAPL ganglia is proposed and investigated in this study. Experiments are performed to first determine the effects of acoustic waves on the transport of a conservative tracer in a water-saturated column packed with glass beads. From resulting experimental tracer data, the addition of acoustic waves, in the frequency range between 60 to 245 Hz, to a steady background fluid flow (base case) is found to enhance solute transport compared to the base case. Furthermore, the effective velocity of the solute is approximately inversely proportional to the frequency of the acoustic wave. Next, the effects of acoustic waves on the dissolution of trichloroethylene (TCE) DNAPL ganglia in a water saturated column, packed with glass beads are investigated. Acoustic waves with pressure amplitudes ranging from 0 to 1625 Pa and frequencies ranging from 0 to 285 Hz are employed to the interstitial fluid at the inlet of the packed column. Effluent dissolved TCE concentrations are observed to increase in the presence of acoustic pressure waves compared to the case where TCE dissolution without acoustic waves is monitored. The observed effluent dissolved TCE concentration increase is attributed to increased mass flux at the TCE-water interface, caused by acoustic waves. As an extension to the single component ganglia dissolution experiments, the impact of acoustic pressure waves on multicomponent DNAPL ganglia dissolution is also investigated. The multicomponent ganglia was composed of TCE and 1,1,2-trichloroethane (1,1,2-TCA) or TCE, 1,1,2-TCA, and tetrachloroethylene (PCE). Laboratory data from ganglia dissolution experiments with two and three component NAPL mixtures

  4. Development of a pore network simulation model to study nonaqueous phase liquid dissolution (United States)

    Dillard, Leslie A.; Blunt, Martin J.


    A pore network simulation model was developed to investigate the fundamental physics of nonequilibrium nonaqueous phase liquid (NAPL) dissolution. The network model is a lattice of cubic chambers and rectangular tubes that represent pore bodies and pore throats, respectively. Experimental data obtained by Powers [1992] were used to develop and validate the model. To ensure the network model was representative of a real porous medium, the pore size distribution of the network was calibrated by matching simulated and experimental drainage and imbibition capillary pressure-saturation curves. The predicted network residual styrene blob-size distribution was nearly identical to the observed distribution. The network model reproduced the observed hydraulic conductivity and produced relative permeability curves that were representative of a poorly consolidated sand. Aqueous-phase transport was represented by applying the equation for solute flux to the network tubes and solving for solute concentrations in the network chambers. Complete mixing was found to be an appropriate approximation for calculation of chamber concentrations. Mass transfer from NAPL blobs was represented using a corner diffusion model. Predicted results of solute concentration versus Peclet number and of modified Sherwood number versus Peclet number for the network model compare favorably with experimental data for the case in which NAPL blob dissolution was negligible. Predicted results of normalized effluent concentration versus pore volume for the network were similar to the experimental data for the case in which NAPL blob dissolution occurred with time.

  5. Dissolved organic carbon enhances the mass transfer of hydrophobic organic compounds from Nonaqueous Phase Liquids (NAPLs) into the aqueous phase

    NARCIS (Netherlands)

    Smith, K.E.C.; Thullner, M.; Wick, L.Y.; Harms, H.


    The hypothesis that dissolved organic carbon (DOC) enhances the mass transfer of hydrophobic organic compounds from nonaqueous phase liquids (NAPLs) into the aqueous phase above that attributable to dissolved molecular diffusion alone was tested. In controlled experiments, mass transfer rates of

  6. Biodegradation of naphthalene from nonaqueous-phase liquids

    International Nuclear Information System (INIS)

    Ghoshal, S.; Luthy, R.G.; Ramaswami, A.


    Dissolution of polycyclic aromatic hydrocarbons (PAHs) from a non-aqueous-phase liquid (NAPL) to the aqueous phase renders these compounds bioavailable to microorganisms. Subsequent biodegradation of organic phase PAH then results in a depletion of PAH from the NAPL. This study focuses on identifying the rate-controlling processes affecting naphthalene biomineralization from a complex multicomponent NAPL, coal tar, and a simple two-component NAPL. A simplified dissolution degradation model is presented to identify quantitative criteria to assess whether mass transfer or biokinetic limitations control the overall rate of biotransformation of PAH compounds. Results show that the rate of mass transfer may control the overall rate of biotransformation in certain systems. Mass transfer does not limit biodegradation in slurry systems when coal tar is distributed in the micropores of a large number of small microporous silica particles. The end points of naphthalene degradation from the NAPLs have been evaluated, and results suggest that depletion of a significant mass of naphthalene from the NAPL phase is possible

  7. Formation of residual NAPL in three-phase systems: Experiments and numerical simulations

    NARCIS (Netherlands)

    Hofstee, C.; Oostrom, M.


    The formation of residual, discontinuous nonaqueous phase liquids (NAPLs) in the vadose zone is a process that is not well understood. The simulators have conveniently implemented the Leverett concept (Leverett and Lewis, 1941) which states that in a water-wet porous media, when fluid wettabilities

  8. Field test of high molecular weight alcohol flushing for subsurface nonaqueous phase liquid remediation (United States)

    Falta, Ronald W.; Lee, Cindy M.; Brame, Scott E.; Roeder, Eberhard; Coates, John T.; Wright, Charles; Wood, A. Lynn; Enfield, Carl G.


    A pilot scale field test of non-aqueous phase liquid (NAPL) removal using high molecular weight alcohols was conducted at Operable Unit 1, Hill Air Force Base, Utah. Petroleum hydrocarbons and spent solvents were disposed of in chemical disposal pits at this site, and these materials are now present in the subsurface in the form of a light non-aqueous phase liquid (LNAPL). This LNAPL is a complex mixture of aromatic and aliphatic hydrocarbons, chlorinated solvents, and other compounds. The field experiment was performed in a 5 m by 3 m confined test cell, formed by driving interlocking sheet pile walls through the contaminated zone into an underlying clay. The test involved the injection and extraction of about four pore volumes (1 pore volume=7000 L) of a mixture of 80% tert-butanol and 15% n-hexanol. The contaminants were removed by a combination of NAPL mobilization and enhanced dissolution, and the results of postflood soil coring indicate better than 90% removal of the more soluble contaminants (trichloroethane, toluene, ethylbenzene, xylenes, trimethylbenzene, naphthalene) and 70-80% removal of less soluble compounds (decane and undecane). The results of preflood and postflood NAPL partitioning tracer tests show nearly 80% removal of the total NAPL content from the test cell. The field data suggest that a somewhat higher level of removal could be achieved with a longer alcohol injection.

  9. Equilibrium nonaqueous phase liquid pool geometry in coarse soils with discrete textural interfaces. (United States)

    Miller, C D; Durnford, D S; Fowler, A B


    This paper presents a model for the geometry of nonaqueous phase liquid (NAPL) pools and mounds in homogeneous soils and soils with discrete textural interfaces. It is shown that the concepts of capillary pressure-saturation curve hysteresis and entry pressures are integral to the complete conceptualization of pool and mound geometry. Unless hysteresis is included in the analysis, light NAPL (LNAPL) in homogeneous soils cannot exist in pools at all, and dense NAPL (DNAPL) will not mound on horizontal textural interfaces unless lateral confining boundaries are present. The proposed model also implies that remobilization of DNAPL pools will occur at lower hydraulic gradients than those predicted with previous models. Comparing predicted and experimental DNAPL and LNAPL pool thicknesses and the location of an LNAPL lens with respect to the top of the capillary fringe validate the model. Copyright 2003 Elsevier B.V.

  10. Containment and recovery of a light non-aqueous phase liquid plume at a woodtreating facility

    International Nuclear Information System (INIS)

    Crouse, D.; Powell, G.; Hawthorn, S.; Weinstock, S.


    A woodtreating site in Montana used a formulation (product) of 5 percent pentachlorophenol and 95 percent diesel fuel as a carrier liquid to pressure treat lumber. Through years of operations approximately 378,500 liters of this light non-aqueous phase liquid (LNAPL) product spilled onto the ground and soaked into the groundwater. A plume of this LNAPL product flowed in a northerly direction toward a stream located approximately 410 meters from the pressure treatment building. A 271-meter long high density polyethylene (HDPE) containment cutoff barrier wall was installed 15 meters from the stream to capture, contain, and prevent the product from migrating off site. This barrier was extended to a depth of 3.7 meters below ground surface and allowed the groundwater to flow beneath it. Ten product recovery wells, each with a dual-phase pumping system, were installed within the plume, and a groundwater model was completed to indicate how the plume would be contained by generating a cone of influence at each recovery well. The model indicated that the recovery wells and cutoff barrier wall would contain the plume and prevent further migration. To date, nearly 3 1/2 year's later, approximately 106,000 liters of product have been recovered

  11. The behaviour of dense, non-aqueous phase liquid contaminants in heterogeneous porous media

    Energy Technology Data Exchange (ETDEWEB)

    Kueper, B.H.


    Dense, non-aqueous phase liquids (DNAPLs) such as polychlorinated biphenyl oils, creosotes and chlorinated solvents represent a unique class of groundwater contaminants, with many being denser and less viscous than water, and only slightly soluble in water. The behavior of DNAPLs in naturally occurring sandy aquifers was examined with an emphasis on the influence of porous media heterogeneity. Extensive use is made of laboratory mesurements and numerical modelling to illustrate that the behavior of DNAPLs in heterogeneous porous media is governed by the spatial distribution of capillary properties. The degree of lateral spreading of DNAPLs on lenses of different permeability is found to be a function of fluid density, as well as interfacial tension between the fluids of concern and the source strength of DNAPL released. A two dimensional vertical section two phase flow model was developed using the finite difference technique. The numerical model was validated against a parallel plate laboratory experiment involving the infiltration of tetrachloroethylene into a heterogeneous sand pack, yielding excellent agreement between the experimental and numerical simulation results. Numerical simulations were performed in a statistically generated realization of the Borden aquifer to investigate the sensitivity of fluid properties and source strength on the migration of DNAPL in a field scale aquifer. Distribution of DNAPL was found to be extremely chaotic. 6 refs., 65 figs., 13 tabs.

  12. Multiphase flow and transport caused by spontaneous gas phase growth in the presence of dense non-aqueous phase liquid. (United States)

    Roy, James W; Smith, James E


    Disconnected bubbles or ganglia of trapped gas may occur below the top of the capillary fringe through a number of mechanisms. In the presence of dense non-aqueous phase liquid (DNAPL), the disconnected gas phase experiences mass transfer of dissolved gases, including volatile components from the DNAPL. The properties of the gas phase interface can also change. This work shows for the first time that when seed gas bubbles exist spontaneous gas phase growth can be expected to occur and can significantly affect water-gas-DNAPL distributions, fluid flow, and mass transfer. Source zone behaviour was observed in three different experiments performed in a 2-dimensional flow cell. In each case, a DNAPL pool was created in a zone of larger glass beads over smaller glass beads, which served as a capillary barrier. In one experiment effluent water samples were analyzed to determine the vertical concentration profile of the plume above the pool. The experiments effectively demonstrated a) a cycle of spontaneous gas phase expansion and vertical advective mobilization of gas bubbles and ganglia above the DNAPL source zone, b) DNAPL redistribution caused by gas phase growth and mobilization, and c) that these processes can significantly affect mass transport from a NAPL source zone.

  13. Laboratory study of non-aqueous phase liquid and water co-boiling during thermal treatment. (United States)

    Zhao, C; Mumford, K G; Kueper, B H


    In situ thermal treatment technologies, such as electrical resistance heating and thermal conductive heating, use subsurface temperature measurements in addition to the analysis of soil and groundwater samples to monitor remediation performance. One potential indication of non-aqueous phase liquid (NAPL) removal is an increase in temperature following observations of a co-boiling plateau, during which subsurface temperatures remain constant as NAPL and water co-boil. However, observed co-boiling temperatures can be affected by the composition of the NAPL and the proximity of the NAPL to the temperature measurement location. Results of laboratory heating experiments using single-component and multi-component NAPLs showed that local-scale temperature measurements can be mistakenly interpreted as an indication of the end of NAPL-water co-boiling, and that significant NAPL saturations (1% to 9%) remain despite observed increases in temperature. Furthermore, co-boiling of multi-component NAPL results in gradually increasing temperature, rather than a co-boiling plateau. Measurements of gas production can serve as a complementary metric for assessing NAPL removal by providing a larger-scale measurement integrated over multiple smaller-scale NAPL locations. Measurements of the composition of the NAPL condensate can provide ISTT operators with information regarding the progress of NAPL removal for multi-component sources. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Molecular dynamics simulation of cyclodextrin aggregation and extraction of Anthracene from non-aqueous liquid phase

    International Nuclear Information System (INIS)

    Zhu, Xinzhe; Wu, Guozhong; Chen, Daoyi


    Cyclodextrin (CD) extraction is widely used for the remediation of polycyclic aromatic hydrocarbons (PAH) pollution, but it remains unclear about the influence of CD aggregation on the PAH transport from non-aqueous liquid phase to water. The atomistic adsorption and complexation of PAHs (32 anthracenes) by CD aggregates (48 β-cyclodextrins) were studied by molecular dynamics simulations at hundreds of nanoseconds time scale. Results indicated that high temperature promoted the βCD aggregation in bulk oil, which was not found in bulk water. Nevertheless, the fractions of anthracenes entrapped inside the βCDs cavity in both scenarios were significantly increased when temperature increased from 298 to 328 K. Free energy calculation for the sub-steps of CD extraction demonstrated that the anthracenes could be extracted when the βCDs arrived at the water-oil interface or after the βCDs entered the bulk oil. The former was kinetic-controlled while the latter was thermodynamic-limited process. Results also highlighted the formation of porous structures by CD aggregates in water, which was able to sequestrate PAH clusters with the size obviously larger than the cavity diameter of individual CD. This provided an opportunity for the extraction of recalcitrant PAHs with molecular size larger than anthracenes by cyclodextrins.

  15. Mechanism for migration of light nonaqueous phase liquids beneath the water table

    International Nuclear Information System (INIS)

    Krueger, J.P.; Portman, M.E.


    This paper reports on an interesting transport mechanism may account for the presence of light nonaqueous phase liquid (LNAPL) found beneath the water table in fine-grained aquifers. During the course of two separate site investigations related to suspected releases from underground petroleum storage tanks, LNAPL was found 7 to 10 feet below the regional water table. In both cases, the petroleum was present within a sand seam which was encompassed within a deposit of finer-grained sediments. The presence of LNAPL below the water table is uncommon; typically, LNAPL is found floating on the water table or on the capillary fringe. The occurrence of LNAPL below the water table could have resulted from fluctuating regional water levels which allowed the petroleum to enter the sand when the water table was a lower stage or, alternately, could have occurred as a result of the petroleum depressing the water table beneath the level of the sand. In fine-grained soils where the lateral migration rate is low, the infiltrating LNAPL may depress the water table to significant depth. The LNAPL may float on the phreatic surface with the bulk of its volume beneath the phreatic surface. Once present in the sand and surrounded by water-saturated fine-grained sediments, capillary forces prevent the free movement of the petroleum back across the boundary from the coarse-grained sediments to the fine-grained sediments. Tapping these deposits with a coarser grained filter packed monitoring well releases the LNAPL, which may accumulate to considerable thickness in the monitoring well

  16. Determination of heavy polycyclic aromatic hydrocarbons by non-aqueous reversed phase liquid chromatography: Application and limitation in refining streams. (United States)

    Panda, Saroj K; Muller, Hendrik; Al-Qunaysi, Thunayyan A; Koseoglu, Omer R


    The heavy polycyclic aromatic hydrocarbons (HPAHs) cause detrimental effects to hydrocracker operations by deactivating the catalysts and depositing in the downstream of the reactor/ exchangers. Therefore, it is essential to continuously monitor the accumulation of HPAHs in a hydrocracker unit. To accurately measure the concentration of HPAHs, the development of a fast and reliable analytical method is inevitable. In this work, an analytical method based on non-aqueous reversed phase chromatography in combination with high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was developed. As a first step, five different types of stationary phases were evaluated for the separation of HPAHs in non-aqueous mode and the best suited phase was further used for the fractionation of HPAHs in a fractionator bottom sample obtained from a refinery hydrocracker unit. The eight major fractions or peaks obtained from the separation were further characterized by UV spectroscopy and FT-ICR MS and the compounds in the fractions were tentatively confirmed as benzoperylene, coronene, methylcoronene, naphthenocoronene, benzocoronene, dibenzoperylene, naphthocoronene and ovalene. The developed liquid chromatography method can be easily adapted in a refinery laboratory for the quantitation of HPAHs in hydrocracking products. The method was further tested to check the interference of sulfur aromatics and/or large alkylated aromatic hydrocarbons on the determination of HPAHs in hydrocracking products. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Nonideal equilibrium dissolution of trichloroethene from a decane-based nonaqueous phase liquid mixture: Experimental and modeling investigation (United States)

    McCray, John E.; Dugan, Pamela J.


    Batch equilibrium solubility studies were conducted to examine the solubilization behavior of a chlorinated solvent, trichloroethene (TCE), from a fuel-based nonaqueous phase liquid (NAPL) mixture. An alkane (n-decane) was used as a model compound because it is often a primary compound in jet fuel. The NAPL phase mole fractions of the chlorinated solvent in the mixture (XTCEN) that were investigated are typical of in situ values found at industrial and military waste sites (0.0001 >= XTCEN UNIFAC method greatly underpredicts the γTCEN in this surrogate fuel. A NAPL-mixture equilibrium-dissolution model was developed that incorporates the observed nonideal dissolution. This model indicates that nonideal NAPL dissolution is 4 times faster than ideal dissolution for a hypothetical NAPL mixture with an initial XTCEN = 0.001. The magnitude of this effect becomes more important as the initial value of the XTCEN is decreased.

  18. Partition coefficients for alcohol tracers between nonaqueous-phase liquids and water from UNIFAC-solubility method (United States)

    Wang, Peng; Dwarakanath, Varadarajan; Rouse, Bruce A.; Pope, Gary A.; Sepehrnoori, Kamy

    In this work, we have applied a group-contribution activity-coefficient model, UNIFAC, and the solubility of alcohols in water to estimate partition coefficients for alcohol tracers between water and nonaqueous-phase liquids (NAPLs). The effects of temperature and mutual solubility between NAPL and aqueous phases on the estimation of partition coefficients were also investigated. By comparing the estimated results with experimental partition coefficients for 30 alcohol tracers between 10 NAPLs and water, we found that: i) the UNIFAC-solubility method, in which the UNIFAC model in its infinite-dilution form is applied to the NAPL phase and the solubility of tracers in water is used for estimation of the activity coefficient in the aqueous phase, works better than the UNIFAC model; ii) a linear relation between the logarithm of partition coefficients and the logarithm of tracer solubility in water is observed for those tracers having a similar chemical structure (i.e. the same number of branched methyl groups). This can serve as a useful tool for quick selection of the tracers that exhibit the desired partition coefficients; iii) the effect of mutual solubility between NAPL and aqueous phases can be neglected because such miscibility is very small, usually of the order of 10 -3 mole/mole unit; and iv) temperature variation between 15° and 25°C does not significantly affect partition coefficients.

  19. Push-pull partitioning tracer tests using radon-222 to quantify non-aqueous phase liquid contamination. (United States)

    Davis, B M; Istok, J D; Semprini, L


    Naturally occurring radon in groundwater can be used as an in situ partitioning tracer for locating and quantifying non-aqueous phase liquid (NAPL) contamination in the subsurface. When combined with the single-well, push-pull test, this methodology has the potential to provide a low-cost alternative to inter-well partitioning tracer tests. During a push-pull test, a known volume of test solution (radon-free water containing a conservative tracer) is first injected ("pushed") into a well; flow is then reversed and the test solution/groundwater mixture is extracted ("pulled") from the same well. In the presence of NAPL radon transport is retarded relative to the conservative tracer. Assuming linear equilibrium partitioning, retardation factors for radon can be used to estimate NAPL saturations. The utility of this methodology was evaluated in laboratory and field settings. Laboratory push-pull tests were conducted in both non-contaminated and trichloroethene NAPL (TCE)-contaminated sediment. The methodology was then applied in wells located in non-contaminated and light non-aqueous phase liquid (LNAPL)-contaminated portions of an aquifer at a former petroleum refinery. The method of temporal moments and an approximate analytical solution to the governing transport equations were used to interpret breakthrough curves and estimate radon retardation factors; estimated retardation factors were then used to calculate TCE saturations. Numerical simulations were used to further investigate the behavior of the breakthrough curves. The laboratory and field push-pull tests demonstrated that radon retardation does occur in the presence of TCE and LNAPL and that radon retardation can be used to calculate TCE saturations. Laboratory injection-phase test results in TCE-contaminated sediment yielded radon retardation factors ranging from 1.1 to 1.5, resulting in calculated TCE saturations ranging from 0.2 to 0.9%. Laboratory extraction-phase test results in the same sediment

  20. Enhancement of Lipase Enzyme Activity in Non-Aqueous Media through a Rapid Three Phase Partitioning and Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    N. Saifuddin


    Full Text Available Three phase partitioning is fast developing as a novel bio-separation strategy with a wide range of applications including enzyme stability and enhancement of its catalytic activity. pH tuning of enzyme is now well known for use in non-aqueous systems. Tuned enzyme was prepared using a rapid drying technique of microwave dehydration (time required around 15 minutes. Further enhancement was achieved by three phase partitioning (TPP method. With optimal condition of ammonium sulphate and t-butanol, the protein appeared as an interfacial precipitate between upper t-butanol and lower aqueous phases. In this study we report the results on the lipase which has been subjected to pH tuning and TPP, which clearly indicate the remarkable increase in the initial rate of transesterification by 3.8 times. Microwave irradiation was found to increase the initial reaction rates by further 1.6 times, hence giving a combined increase in activity of about 5.4 times. Hence it is shown that microwave irradiation can be used in conjunction with other strategies (like pH tuning and TPP for enhancing initial reaction rates.

  1. Diffusive partitioning tracer test for the quantification of nonaqueous phase liquid (NAPL) in the vadose zone: performance evaluation for heterogeneous NAPL distribution. (United States)

    Werner, David; Karapanagioti, Hrissi K; Höhener, Patrick


    A partitioning tracer test based on gas-phase diffusion in the vadose zone yields estimates of the residual nonaqueous phase liquid (NAPL) saturation. The present paper investigates this technique further by studying diffusive tracer breakthrough curves in the vadose zone for a heterogeneous NAPL distribution. Tracer experiments were performed in a lysimeter with a horizontal layer of artificial kerosene embedded in unsaturated sand. Tracer disappearance curves at the injection point and tracer breakthrough curves at some distance from the injection point were measured inside and outside of the NAPL layer. A numerical code was used to generate independent model predictions based on the physicochemical sand, NAPL, and tracer properties. The measured and modeled tracer breakthrough curves were in good agreement confirming the validity of important modeling assumptions such as negligible sorption of chlorofluorocarbon (CFC) tracers to the uncontaminated sand and their fast reversible partitioning between the soil air and the NAPL phase. Subsequently, the model was used to investigate different configurations of NAPL contamination. The experimental and model results show that the tracer disappearance curves of a single-well diffusive partitioning tracer test (DPTT) are dominated by the near-field presence of NAPL around the tip of the soil gas probe. In contrast, breakthrough curves of inter-well tracer tests reflect the NAPL saturation in between the probes, although there is no unique interpretation of the tracer signals if the NAPL distribution is heterogeneous. Numerical modeling is useful for the planning of a DPTT application. Simulations suggest that several cubic meters of soil can be investigated with a single inter-well partitioning tracer test of 24-hour duration by placing the injection point in the center of the investigated soil volume and probes at up to 1 m distance for the monitoring of gaseous tracers.

  2. Modelling mass transfer during venting/soil vapour extraction: Non-aqueous phase liquid/gas mass transfer coefficient estimation (United States)

    Esrael, D.; Kacem, M.; Benadda, B.


    We investigate how the simulation of the venting/soil vapour extraction (SVE) process is affected by the mass transfer coefficient, using a model comprising five partial differential equations describing gas flow and mass conservation of phases and including an expression accounting for soil saturation conditions. In doing so, we test five previously reported quations for estimating the non-aqueous phase liquid (NAPL)/gas initial mass transfer coefficient and evaluate an expression that uses a reference NAPL saturation. Four venting/SVE experiments utilizing a sand column are performed with dry and non-saturated sand at low and high flow rates, and the obtained experimental results are subsequently simulated, revealing that hydrodynamic dispersion cannot be neglected in the estimation of the mass transfer coefficient, particularly in the case of low velocities. Among the tested models, only the analytical solution of a convection-dispersion equation and the equation proposed herein are suitable for correctly modelling the experimental results, with the developed model representing the best choice for correctly simulating the experimental results and the tailing part of the extracted gas concentration curve.

  3. A method of estimating multicomponent nonaqueous-phase liquid mass in porous media using aqueous concentration ratios. (United States)

    Devlint, J F; Barbaro, J R


    A simple dissolution model based on Raoult's Law was used to derive a log-linear equation for the estimation of multicomponent nonaqueous-phase liquid (NAPL) mass in porous media. The analysis, referred to here as the ratio mass estimation (RME) method, requires aqueous concentration ratios for two components of the NAPL mixture as well as their pure phase liquid solubilities. Application of the equation using data from a previously reported column experiment, in which 1.22 g of a benzene/toluene NAPL were flushed with water, yielded an estimate of 1.2 g of NAPL. In addition, data from two in situ field column experiments of gasoline dissolution were examined. In those experiments, three ratio pairs, benzene/toluene, ethylbenzene/toluene, and ethylbenzene/benzene, were considered from each cell, and the initial NAPL masses were estimated to be between 39 and 42 kg NAPL, within 30% of the true NAPL masses of 54 kg in each cell. Finally, data from the flushing of a controlled release of chlorinated solvents (chloroform, trichloroethene, and tetrachloroethene) inside a sheet pile cell were examined, and the initial NAPL mass was estimated to within 15% of the true value. The RME analysis is based on several simplifying assumptions and should be used with caution. However, this work shows it to be potentially useful under conditions that might be encountered at sites. The analysis is simple and based on data that are often collected routinely.

  4. Determination of Three-Dimensional Morphology and Inner Structure of Second-Phase Inclusions in Metals by Non-Aqueous Solution Electrolytic and Room Temperature Organic Methods


    Jing Guo; Keming Fang; Hanjie Guo; Yiwa Luo; Shengchao Duan; Xiao Shi; Wensheng Yang


    The secondary-phase particles in metals, particularly those composed of non-metallic materials, are often detrimental to the mechanical properties of metals; thus, it is crucial to control inclusion formation and growth. One of the challenges is determining the three-dimensional morphology and inner structures of such inclusions. In this study, a non-aqueous solution electrolytic method and a room-temperature organic technique were developed based on the principle of electrochemistry to deter...

  5. Estimating Mass Discharge From Dense Nonaqueous Phase Liquid Source Zones Using Upscaled Mass Transfer Coefficients: An Evaluation Using Multiphase Numerical Simulations (United States)


    parameters including groundwater velocity, mean hydraulic conductivity, and the extent of mass removal using best fit correlation parameters. These upscaled ...Estimating mass discharge from dense nonaqueous phase liquid source zones using upscaled mass transfer coefficients: An evaluation using multiphase...of a number of simplified models that rely upon upscaled (i.e., domain-averaged) mass transfer coefficients to approximate field-scale dissolution

  6. Rare Earth Element Phases in Bauxite Residue

    Directory of Open Access Journals (Sweden)

    Johannes Vind


    Full Text Available The purpose of present work was to provide mineralogical insight into the rare earth element (REE phases in bauxite residue to improve REE recovering technologies. Experimental work was performed by electron probe microanalysis with energy dispersive as well as wavelength dispersive spectroscopy and transmission electron microscopy. REEs are found as discrete mineral particles in bauxite residue. Their sizes range from <1 μm to about 40 μm. In bauxite residue, the most abundant REE bearing phases are light REE (LREE ferrotitanates that form a solid solution between the phases with major compositions (REE,Ca,Na(Ti,FeO3 and (Ca,Na(Ti,FeO3. These are secondary phases formed during the Bayer process by an in-situ transformation of the precursor bauxite LREE phases. Compared to natural systems, the indicated solid solution resembles loparite-perovskite series. LREE particles often have a calcium ferrotitanate shell surrounding them that probably hinders their solubility. Minor amount of LREE carbonate and phosphate minerals as well as manganese-associated LREE phases are also present in bauxite residue. Heavy REEs occur in the same form as in bauxites, namely as yttrium phosphates. These results show that the Bayer process has an impact on the initial REE mineralogy contained in bauxite. Bauxite residue as well as selected bauxites are potentially good sources of REEs.

  7. Field study of using naturally occurring radon to assess the dense non-aqueous phase liquid distribution in saturated zone. (United States)

    Chen, Yao-Tsung; Tung, Tien-Hsing; Wang, Lung-Chang; Lu, Chih-Jen


    The concept of radon deficiency such as the ratios of radon concentrations to the maximum measured value of a sample batch was employed as the survey methodology for this study to investigate contamination sources in an industrial zone that was suspected of causing subsurface dense non-aqueous phase liquid (DNAPL) contamination. The results showed that radon concentrations in certain wells were significantly lower than that in uncontaminated regions. Radon concentrations in groundwater are influenced by the in situ bioremediation of vegetable oil, which causes abnormal reductions of the radon in groundwater because radon partitions into vegetable oil and results in more variable for the radon deficit method to showing the impacts of remediation. Six contaminated regions were identified by integrating radon concentration ratios (divided into low (L), middle (M), and high (H) levels) and DNAPL concentrations (divided into low (L) and high (H) levels). Contaminated regions in the LH, MH, and HH categories are located in the vicinity of the contamination source, and those in the HL category are located far from the source zone. The ML and LL categories indicate the involvement of unknown factors, and that additional analyses are required to uncover the facts that affect radon and DNAPL concentrations. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Metal Oxide-Carbon Nanocomposites for Aqueous and Nonaqueous Supercapacitors, Phase I (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I effort focuses on development of novel metal-oxide-carbon nanocomposites for application in pseudocapacitive...

  9. Effect of water-table fluctuation on dissolution and biodegradation of a multi-component, light nonaqueous-phase liquid (United States)

    Dobson, Richard; Schroth, Martin H.; Zeyer, Josef


    Light nonaqueous-phase liquids (LNAPLs) such as gasoline and diesel fuel are among the most common causes of soil and groundwater contamination. Dissolution and subsequent advective transport of LNAPL components can negatively impact water supplies, while biodegradation is thought to be an important sink for this class of contaminants. We present a laboratory investigation of the effect of a water-table fluctuation on dissolution and biodegradation of a multi-component LNAPL (85% hexadecane, 5% toluene, 5% ethylbenzene, and 5% 2-methylnapthalene on a molar basis) in a pair of similar model aquifers (80 cm × 50 cm × 3 cm), one of which was subjected to a water-table fluctuation. Water-table fluctuation resulted in LNAPL and air entrapment below the water table, an increase in the vertical extent of the LNAPL source zone (by factor 6.7), and an increase in the volume of water passing through the source zone (by factor ˜ 18). Effluent concentrations of dissolved LNAPL components were substantially higher and those of dissolved nitrate lower in the model aquifer where a fluctuation had been induced. Thus, water-table fluctuation led to enhanced biodegradation activity (28.3 mmol of nitrate consumed compared to 16.3 mmol in the model without fluctuation) as well as enhanced dissolution of LNAPL components. Despite the increased biodegradation, fluctuation led to increased elution of dissolved LNAPL components from the system (by factors 10-20). Hence, water-table fluctuations in LNAPL-contaminated aquifers might be expected to result in increased exposure of downgradient receptors to LNAPL components. Accordingly, water-table fluctuations in contaminated aquifers are probably undesirable unless the LNAPL is of minimal solubility or the dissolved-phase plume is not expected to reach a receptor due to distance or the presence of some form of containment.

  10. Nonaqueous phase liquid dissolution and soil organic matter sorption in porous media: review of system similarities

    NARCIS (Netherlands)

    Heyse, Edward; Augustijn, Dionysius C.M.; Suresh, P.; Rao, C.; Delfino, Joseph J.


    We examine similarities in constraints to mass transfer of hydrophobic organic compounds (HOCs) between the aqueous and various organic phases in porous media at the grain scale. Published research and data are reviewed regarding equilibrium coefficients and first-order rate constants for mass

  11. Refinement of the Kansas City Plant site conceptual model with respect to dense non-aqueous phase liquids (DNAPL)

    International Nuclear Information System (INIS)

    Korte, N.E.; Hall, S.C.; Baker, J.L.


    This document presents a refinement of the site conceptual model with respect to dense non-aqueous phase liquid (DNAPL) at the US Department of Energy Kansas City Plant (KCP). This refinement was prompted by a review of the literature and the results of a limited study that was conducted to evaluate whether pools of DNAPL were present in contaminated locations at the KCP. The field study relied on the micropurge method of sample collection. This method has been demonstrated as a successful approach for obtaining discrete samples within a limited aquifer zone. Samples were collected at five locations across 5-ft well screens located at the base of the alluvial aquifer at the KCP. The hypothesis was that if pools of DNAPL were present, the dissolved concentration would increase with depth. Four wells with highly contaminated groundwater were selected for the test. Three of the wells were located in areas where DNAPL was suspected, and one where no DNAPL was believed to be present. The results demonstrated no discernible pattern with depth for the four wells tested. A review of the data in light of the available technical literature suggests that the fine-grained nature of the aquifer materials precludes the formation of pools. Instead, DNAPL is trapped as discontinuous ganglia that are probably widespread throughout the aquifer. The discontinuous nature of the DNAPL distribution prevents the collection of groundwater samples with concentrations approaching saturation. Furthermore, the results indicate that attempts to remediate the aquifer with conventional approaches will not result in restoration to pristine conditions because the tortuous groundwater flow paths will inhibit the efficiency of fluid-flow-based treatments


    Energy Technology Data Exchange (ETDEWEB)

    Michael G. Waddell; William J. Domoracki; Tom J. Temples; Jerome Eyer


    The Earth Sciences and Resources Institute, University of South Carolina is conducting a 14 month proof of concept study to determine the location and distribution of subsurface Dense Nonaqueous Phase Liquid (DNAPL) carbon tetrachloride (CCl{sub 4}) contamination at the 216-Z-9 crib, 200 West area, Department of Energy (DOE) Hanford Site, Washington by use of two-dimensional high resolution seismic reflection surveys and borehole geophysical data. The study makes use of recent advances in seismic reflection amplitude versus offset (AVO) technology to directly detect the presence of subsurface DNAPL. The techniques proposed are a noninvasive means towards site characterization and direct free-phase DNAPL detection. This report covers the results of Task 3 and change of scope of Tasks 4-6. Task 1 contains site evaluation and seismic modeling studies. The site evaluation consists of identifying and collecting preexisting geological and geophysical information regarding subsurface structure and the presence and quantity of DNAPL. The seismic modeling studies were undertaken to determine the likelihood that an AVO response exists and its probable manifestation. Task 2 is the design and acquisition of 2-D seismic reflection data designed to image areas of probable high concentration of DNAPL. Task 3 is the processing and interpretation of the 2-D data. Task 4, 5, and 6 were designing, acquiring, processing, and interpretation of a three dimensional seismic survey (3D) at the Z-9 crib area at 200 west area, Hanford.

  13. Comparison of iso-eluotropic mobile phases at different temperatures for the separation of triacylglycerols in Non-Aqueous Reversed Phase Liquid Chromatography. (United States)

    Hmida, Dorra; Abderrabba, Manef; Tchapla, Alain; Héron, Sylvie; Moussa, Fathi


    Triacylglycerols (TAGs) are a large class of neutral lipids that naturally occur in both plant and animal oils and fats. Their analyses in Non-Aqueous Reversed Phase Liquid Chromatography (NARP) require a mixture of weak solvent (mostly acetonitrile) and strong solvent. In the present work, we have established eluotropic solvent strength scale of several binary mobile phases on C18 bonded silica at different temperatures (acetonitrile/methylene chloride, acetonitrile/acetone, acetonitrile/ethyl acetate, acetonitrile/propan-2-ol, and acetonitrile/butan-1-ol at 25°C, 43°C, 63°C and 85°C); it is based on the methylene selectivity and the use of homologous series. We show that this scale is well suited to the TAGs analysis. The analysis of nine seed oils (Aleurites fordii, Calophyllum inophyllum, Glycina max, Olea europea, Orbignya olifeira, Pinus koraiensis, Pistacia lentiscus, Punica granatum and Ribes nigrum) in iso-eluotropic conditions leads to propose unambiguously the couple MeCN/BuOH at 25°C as the best system to separate TAGs. The use of butanol, as strong solvent, provides very good TAGs congeners separations and avoids the use of chlorinated solvents which gave to this day the best separations. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Nonaqueous Phase Liquid Dissolution in Porous Media: Multi-Scale Effects of Multi-Component Dissolution Kinetics on Cleanup Time

    Energy Technology Data Exchange (ETDEWEB)

    McNab, W; Ezzedine, S; Detwiler, R


    Industrial organic solvents such as trichloroethylene (TCE) and tetrachloroethylene (PCE) constitute a principal class of groundwater contaminants. Cleanup of groundwater plume source areas associated with these compounds is problematic, in part, because the compounds often exist in the subsurface as dense nonaqueous phase liquids (DNAPLs). Ganglia (or 'blobs') of DNAPL serve as persistent sources of contaminants that are difficult to locate and remediate (e.g. Fenwick and Blunt, 1998). Current understanding of the physical and chemical processes associated with dissolution of DNAPLs in the subsurface is incomplete and yet is critical for evaluating long-term behavior of contaminant migration, groundwater cleanup, and the efficacy of source area cleanup technologies. As such, a goal of this project has been to contribute to this critical understanding by investigating the multi-phase, multi-component physics of DNAPL dissolution using state-of-the-art experimental and computational techniques. Through this research, we have explored efficient and accurate conceptual and numerical models for source area contaminant transport that can be used to better inform the modeling of source area contaminants, including those at the LLNL Superfund sites, to re-evaluate existing remediation technologies, and to inspire or develop new remediation strategies. The problem of DNAPL dissolution in natural porous media must be viewed in the context of several scales (Khachikian and Harmon, 2000), including the microscopic level at which capillary forces, viscous forces, and gravity/buoyancy forces are manifested at the scale of individual pores (Wilson and Conrad, 1984; Chatzis et al., 1988), the mesoscale where dissolution rates are strongly influenced by the local hydrodynamics, and the field-scale. Historically, the physico-chemical processes associated with DNAPL dissolution have been addressed through the use of lumped mass transfer coefficients which attempt to

  15. Mass spectrometric elucidation of triacylglycerol content of Brevoortia tyrannus (menhaden) oil using non-aqueous reversed-phase liquid chromatography under ultra high pressure conditions. (United States)

    Dugo, Paola; Beccaria, Marco; Fawzy, Nermeen; Donato, Paola; Cacciola, Francesco; Mondello, Luigi


    A non-aqueous reversed phase high performance liquid chromatography method was developed, and optimized for triacylglycerol analysis in a Brevoortia tyrannus (menhaden) oil sample. Four columns were serially coupled to tackle such a task, for a total length of 60 cm of shell-packed stationary phase, and operated under ultra high pressure conditions. As detection, positive-ion atmospheric pressure chemical ionization mass spectrometry was used to attain identification of the analyzed sample components. A number of 137 triacylglycerols containing up to 19 fatty acids, with 14-22 carbon atom alkyl chain length and 0-6 double bonds, were positively identified in the complex lipidic sample. This is the first work that reports an extensive characterization of the triacylglycerol fraction of menhaden oil. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Separation and direct detection of long chain fatty acids and their methylesters by the non-aqueous reversed phase HPLC and Silver Ion Chromotography, combined with CO laser pumped thermal lens spectrometry

    NARCIS (Netherlands)

    Bicanic, D.D.; Mocnik, G.; Franko, M.; Niederlander, H.A.G.; Bovenkamp, van de P.; Cozijnsen, J.L.; Klift, van der E.J.C.


    The potential of the CO laser pumped dual beam thermal lens spectrometer (TLS) used as the detector of infrared (IR) absorbance in non-aqueous reversed-phase high pressure liquid chromatography (NARP-HPLC) and argentation chromatography (Ag-HPLC-TLS) has been investigated. The linoleic acid C18:2

  17. Characterization of fatty acid and triacylglycerol composition in animal fats using silver-ion and non-aqueous reversed-phase high-performance liquid chromatography/mass spectrometry and gas chromatography/flame ionization detection

    Czech Academy of Sciences Publication Activity Database

    Lísa, M.; Netušilová, K.; Franěk, L.; Dvořáková, H.; Vrkoslav, Vladimír; Holčapek, M.


    Roč. 1218, č. 42 (2011), s. 7499-7510 ISSN 0021-9673 R&D Projects: GA ČR GA203/09/0139 Institutional research plan: CEZ:AV0Z40550506 Keywords : silver-ion HPLC * non-aqueous reversed-phase HPLC * triacylglycerol Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.531, year: 2011

  18. Measurement of underground contamination of non-aqueous phase liquids (NAPLs) on the basis of the radon concentration in ground level air

    International Nuclear Information System (INIS)

    Schubert, M.


    It was investigated whether measurements of radon concentrations in ground level air are a suitable method of detecting sub-surface soil contamination with non-aqueous phase liquids (NAPLs). The working postulation was that, due to the very high solubility of radon in NAPLs, and the resulting accumulation of radon in NAPLs, radon exhalation to the ground level air in the proximity of such NAPL contamination should be locally reduced, thus indicating contamination of sub-surface soils with NAPLs. The research work reported was to verify the working theory by way of experiments, and to finally develop a reliable detection method for NAPL contaminations. The investigations comprised theoretical studies, laboratory experiments, experiments in defined soil columns, and extensive field studies [de

  19. Using a multi-method approach based on soil radon deficit, resistivity, and induced polarization measurements to monitor non-aqueous phase liquid contamination in two study areas in Italy and India. (United States)

    Castelluccio, Mauro; Agrahari, Sudha; De Simone, Gabriele; Pompilj, Francesca; Lucchetti, Carlo; Sengupta, Debashish; Galli, Gianfranco; Friello, Pierluigi; Curatolo, Pierpaolo; Giorgi, Riccardo; Tuccimei, Paola


    Geochemical and geophysical surveys employing radon deficit, resistivity, and induced polarization (IP) measurements were undertaken on soil contaminated with non-aqueous phase liquids (NAPLs) in two different sites in India and in Italy. Radon deficit, validated through the comparison with average soil radon in reference unpolluted areas, shows the extension of contamination in the upper part of the unsaturated aquifers. In site 1 (Italy), the spill is not recent. A residual film of kerosene covers soil grains, inhibiting their chargeability and reducing electrical resistivity difference with background unpolluted areas. No correlation between the two parameters is observed. Soil volatile organic compounds (VOCs) concentration is not linked with radon deficit, supporting the old age of the spillage. NAPL pollution in sites 2a and 2b (India) is more recent and probably still active, as demonstrated by higher values of electrical resistivity. A good correlation with IP values suggests that NAPL is still distributed as droplets or as a continuous phase in the pores, strengthening the scenario of a fresh spill or leakage. Residual fraction of gasoline in the pore space of sites 2a and 2b is respectively 1.5 and 11.8 kg per cubic meter of terrain. This estimation is referred to the shallower portion of the unsaturated aquifer. Electrical resistivity is still very high indicating that the gasoline has not been strongly degraded yet. Temperature and soil water content influence differently radon deficit in the three areas, reducing soil radon concentration and partly masking the deficit in sites 2a and 2b.

  20. Phase Chemistry of Tank Sludge Residual Components

    Energy Technology Data Exchange (ETDEWEB)

    J.L. Krumhansl


    The US Department of Energy (DOE) has millions of gallons of high level nuclear waste stored in underground tanks at Hanford, Washington and Savannah River, South Carolina. These tanks will eventually be emptied and decommissioned. This will leave a residue of sludge adhering to the interior tank surfaces that may contaminate nearby groundwaters with radionuclides and RCRA metals. Performance assessment (PA) calculations must be carried out prior to closing the tanks. This requires developing radionuclide release models from the sludges so that the PA calculations can be based on credible source terms. These efforts continued to be hindered by uncertainties regarding the actual nature of the tank contents and the distribution of radionuclides among the various phases. In particular, it is of vital importance to know what radionuclides are associated with solid sludge components. Experimentation on actual tank sludges can be difficult, dangerous and prohibitively expensive. The research funded under this grant for the past three years was intended to provide a cost-effective method for developing the needed radionuclide release models using non-radioactive artificial sludges. Insights gained from this work will also have more immediate applications in understanding the processes responsible for heel development in the tanks and in developing effective technologies for removing wastes from the tanks.

  1. Comparison of a wellpoint vacuum pump system to dual pump recovery system effectiveness for the extraction of light non-aqueous phase liquids

    International Nuclear Information System (INIS)

    Koll, C.S.; Palmerton, D.L. Jr.; Kunzel, R.G.


    The effectiveness of two light non-aqueous phase liquid (LNAPL) extraction systems is compared at a site in the Mid-New Jersey Atlantic Coastal Plains Region: an existing dual pump recovery system and a wellpoint vacuum pump system. Home heating oil was released to a shallow sand and gravel aquifer by a leaky underground distribution system in the early 1970s. Eight-inch-diameter dual pump recovery wells were used for the last nine years, to lower the water table and extract LNAPL at several spill sites located throughout a residential community of 1,500 homes. Several small LNAPL plumes still exist today with surface areas ranging from 400 ft 2 to over 28,000 ft 2 . LNAPL recovery peaked in 1985 using dual pump recovery systems, averaging 33 gallons per day (gpd). In 1987, four 24-inch wells were replaced by 11 8-inch-diameter recovery wells at six sites, and LNAPL recovery rates averaged 5 gpd. In recent years, the recovery of LNAPL has declined and when graphed, is asymptotic. In 1993, dual pump recovery of LNAPL averaged 0.3 gpd for all six sites

  2. Comparison of a wellpoint vacuum pump system to dual pump recovery system effectiveness for the extraction of light non-aqueous phase liquids

    Energy Technology Data Exchange (ETDEWEB)

    Koll, C.S.; Palmerton, D.L. Jr. (Blasland, Bouck and Lee Inc., Syracuse, NY (United States)); Kunzel, R.G. (Moretrench Environmental Services Inc., Rockaway, NJ (United States))

    The effectiveness of two light non-aqueous phase liquid (LNAPL) extraction systems is compared at a site in the Mid-New Jersey Atlantic Coastal Plains Region: an existing dual pump recovery system and a wellpoint vacuum pump system. Home heating oil was released to a shallow sand and gravel aquifer by a leaky underground distribution system in the early 1970s. Eight-inch-diameter dual pump recovery wells were used for the last nine years, to lower the water table and extract LNAPL at several spill sites located throughout a residential community of 1,500 homes. Several small LNAPL plumes still exist today with surface areas ranging from 400 ft[sup 2] to over 28,000 ft[sup 2]. LNAPL recovery peaked in 1985 using dual pump recovery systems, averaging 33 gallons per day (gpd). In 1987, four 24-inch wells were replaced by 11 8-inch-diameter recovery wells at six sites, and LNAPL recovery rates averaged 5 gpd. In recent years, the recovery of LNAPL has declined and when graphed, is asymptotic. In 1993, dual pump recovery of LNAPL averaged 0.3 gpd for all six sites.

  3. Determination of Three-Dimensional Morphology and Inner Structure of Second-Phase Inclusions in Metals by Non-Aqueous Solution Electrolytic and Room Temperature Organic Methods

    Directory of Open Access Journals (Sweden)

    Jing Guo


    Full Text Available The secondary-phase particles in metals, particularly those composed of non-metallic materials, are often detrimental to the mechanical properties of metals; thus, it is crucial to control inclusion formation and growth. One of the challenges is determining the three-dimensional morphology and inner structures of such inclusions. In this study, a non-aqueous solution electrolytic method and a room-temperature organic technique were developed based on the principle of electrochemistry to determine the three-dimensional morphologies and inner structures of non-metallic inclusions in Al-killed steel, Si-killed steel, and ductile cast iron. The inclusions were first extracted without any damage to the inclusions, and then the collected inclusions were wrapped and cut through Cu ion deposition. The results revealed that the inclusions in Al-killed steel had an irregular morphology, that those in the Si-killed steel were mainly spherical, and that almost all the spheroidal graphite in the ductile cast iron featured a uniform globular morphology. In addition, nucleation was not observed in the inner structures of the inclusions in the Al-killed steel, while some dendritic or rod-like MnS phase precipitates appeared on the silicate inclusion surfaces, and some silicate-rich phases were detected in their inner matrix. For spheroidal graphite, rare-earth oxides (one particle or more were observed as nuclei in the center of almost every graphite particle. The formation and evolution of inclusions in these types of metals can be better understood by means of the two developed methods.

  4. Flow Electrification in Nonaqueous Colloidal Suspensions, studied with Video Microscopy

    NARCIS (Netherlands)

    Tolpekin, V.A.; van den Ende, Henricus T.M.; Duits, Michael H.G.; Mellema, J.


    Flow electrification in nonaqueous suspensions has been scarcely reported in the literature but can significantly affect colloidal stability and (phase) behavior, perhaps even without being recognized. We have observed it in shear flow experiments on concentrated binary suspensions of hydrophobized

  5. Organic solvent modifier and temperature effects in non-aqueous size-exclusion chromatography on reversed-phase columns. (United States)

    Caltabiano, Anna M; Foley, Joe P; Striegel, André M


    Common reversed-phase columns (C 18 , C 4 , phenyl, and cyano) offer inert surfaces suitable for the analysis of polymers by size-exclusion chromatography (SEC). The effect of tetrahydrofuran (THF) solvent and the mixtures of THF with a variety of common solvents used in high performance liquid chromatography (acetonitrile, methanol, dimethylformamide, 2-propanol, ethanol, acetone and chloroform) on reversed-phase stationary phase characteristics relevant to size exclusion were studied. The effect of solvent on the elution of polystyrene (PS) and poly(methyl methacrylate) (PMMA) and the effect of column temperature (within a relatively narrow range corresponding to typical chromatographic conditions, i.e., 10°C-60°C) on the SEC partition coefficients K SEC of PS and PMMA polymers, were also investigated. The bonded phases show remarkable differences in size separations when binary mixtures of THF with other solvents are used as the mobile phase. The solvent impact can be two-fold: (i) change of the polymeric coil size, and possible shape, and (ii) change of the stationary phase pore volume. If the effect of this impact is properly moderated, then the greatest benefit of optimized solute resolution can be achieved. Additionally, this work provides an insight on solvent-stationary phase interactions and their effects on column pore volume. The only effect of temperature observed in our studies was a decreased elution volume of the polymers with increasing temperature. SEC partition coefficients were temperature-independent in the range of 10°C-60°C and therefore, over this temperature range elution of PS and PMMA polymers is by near-ideal SEC on reversed-phase columns. Non-ideal SEC appears to occur for high molar mass PMMA polymers on a cyano column when alcohols are used as mobile phase modifiers. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Characterisation of dense non-aqueous phase liquids of coal tar using comprehensive two-dimensional gas chromatography coupled with time of flight mass spectrometry. (United States)

    Gauchotte-Lindsay, Caroline; McGregor, Laura; Richards, Phil; Kerr, Stephanie; Glenn, Aliyssa; Thomas, Russell; Kalin, Robert


    Comprehensive two-dimensional gas chromatography (GCxGC) is a recently developed analytical technique in which two capillary columns with different stationary phases are placed in series enabling planar resolution of the analytes. The resolution power of GCxGC is one order of magnitude higher than that of one dimension gas chromatography. Because of its high resolution capacity, the use of GCxGC for complex environmental samples such as crude oils, petroleum derivatives and polychlorinated biphenyls mixtures has rapidly grown in recent years. We developed a one-step method for the forensic analysis of coal tar dense non-aqueous phase liquids (DNAPLs) from former manufactured gas plant (FMGP) sites. Coal tar is the by-product of the gasification of coal for heating and lighting and it is composed of thousands of organic and inorganic compounds. Before the boom of natural gases and oils, most towns and cities had one or several manufactured gas plants that have, in many cases, left a devastating environmental print due to coal tar contamination. The fate of coal tar DNAPLs, which can persist in the environment for more than a hundred years, is therefore of crucial interest. The presented analytical method consists of a unique clean-up/ extraction stage by pressurized liquid extraction and a single analysis of its organic chemical composition using GCxGC coupled with time of flight mass spectrometry (TOFMS). The chemical fingerprinting is further improved by derivatisation by N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) of the tar compounds containing -OH functions such as alcohols and carboxylic acids. We present here how, using the logical order of elution in GCxGC-TOFMS system, 1) the identification of never before observed -OH containing compounds is possible and 2) the isomeric selectivity of an oxidation reaction on a DNAPL sample can be revealed. Using samples collected at various FMGP sites, we demonstrate how this GCxGC method enables the simultaneous

  7. Effects of single-fracture aperture statistics on entrapment, dissolution and source depletion behavior of dense non-aqueous phase liquids. (United States)

    Yang, Zhibing; Niemi, Auli; Fagerlund, Fritjof; Illangasekare, Tissa


    Understanding of the entrapment and dissolution behavior of dense non-aqueous phase liquids (DNAPLs) in single fractures is important for modeling contaminant flux generation from fractured sites. Here a systematic numerical study is presented to investigate the effect of fracture aperture statistics on DNAPL migration, entrapment and dissolution within individual, variable-aperture fractures. Both fractures with open and closed bottom boundaries were considered. For the simulation a continuum-based two-phase model was used with a capillary pressure function which calculates the entry pressure based on the local aperture. Prior to application the model was compared against the invasion percolation approach and found more suitable for the present study, in particular as it allows a more versatile presentation of boundary conditions. The results showed that increasing aperture standard deviation and/or decreasing correlation length lead to larger amounts of entrapped DNAPL (due to the fact that larger standard deviation produces more distinct contrast between small and large aperture regions and the fact that longer correlation length provides more possible channels through the fracture) as well as larger maximum and average sizes of DNAPL blobs, and subsequently lead to longer times for complete dissolution. To understand the relationship between the solute flux and the remaining mass, a simplified source depletion function which links the outflow concentration to the DNAPL saturation was found adequate to describe the dissolution process for the case where the bottom boundary is open for DNAPL migration and thus the DNAPL does not accumulate to form a pool. The parameters in this function were not very sensitive to variations in correlation length but were sensitive to aperture standard deviation. The same average entrapped DNAPL saturation produced considerably smaller solute concentrations in cases with larger aperture variability due to the larger average size


    International Nuclear Information System (INIS)

    Waddell, Michael G.; Domoracki, William J.; Eyer, Jerome


    The Earth Sciences and Resources Institute, University of South Carolina is conducting a proof of concept study to determine the location and distribution of subsurface DNAPL carbon tetrachloride (CCl 4 ) contamination at the 216-Z-9 crib, 200 West area, DOE Hanford Site, Washington by use of two-dimensional high-resolution seismic reflection surveys and borehole geophysical data. The study makes use of recent advances in seismic reflection amplitude versus offset (AVO) technology to directly detect the presence of subsurface DNAPL. The techniques proposed are noninvasive means of site characterization and direct free-phase DNAPL detection. This final report covers the results of Tasks 1, 2, and 3. Task (1) contains site evaluation and seismic modeling studies. The site evaluation consists of identifying and collecting preexisting geological and geophysical information regarding subsurface structure and the presence and quantity of DNAPL. The seismic modeling studies were undertaken to determine the likelihood that an AVO response exists and its probable manifestation. Task (2) is the design and acquisition of 2-D seismic reflection data to image areas of probable high concentration of DNAPL. Task (3) is the processing and interpretation of the 2-D data. During the commission of these tasks four seismic reflection profiles were collected. Subsurface velocity information was obtained by vertical seismic profile surveys in three wells. The interpretation of these data is in two parts. Part one is the construction and interpretation of structural contour maps of the contact between the Hanford Fine unit and the underlying Plio/Pleistocene unit and of the contact between the Plio/Pleistocene unit and the underlying caliche layer. These two contacts were determined to be the most likely surfaces to contain the highest concentration CCl 4 . Part two of the interpretation uses the results of the AVO modeling to locate any seismic amplitude anomalies that might be


    Energy Technology Data Exchange (ETDEWEB)

    Michael G. Waddell; William J. Domoracki; Jerome Eyer


    The Earth Sciences and Resources Institute, University of South Carolina is conducting a proof of concept study to determine the location and distribution of subsurface DNAPL carbon tetrachloride (CCl{sub 4}) contamination at the 216-Z-9 crib, 200 West area, DOE Hanford Site, Washington by use of two-dimensional high-resolution seismic reflection surveys and borehole geophysical data. The study makes use of recent advances in seismic reflection amplitude versus offset (AVO) technology to directly detect the presence of subsurface DNAPL. The techniques proposed are noninvasive means of site characterization and direct free-phase DNAPL detection. This final report covers the results of Tasks 1, 2, and 3. Task (1) contains site evaluation and seismic modeling studies. The site evaluation consists of identifying and collecting preexisting geological and geophysical information regarding subsurface structure and the presence and quantity of DNAPL. The seismic modeling studies were undertaken to determine the likelihood that an AVO response exists and its probable manifestation. Task (2) is the design and acquisition of 2-D seismic reflection data to image areas of probable high concentration of DNAPL. Task (3) is the processing and interpretation of the 2-D data. During the commission of these tasks four seismic reflection profiles were collected. Subsurface velocity information was obtained by vertical seismic profile surveys in three wells. The interpretation of these data is in two parts. Part one is the construction and interpretation of structural contour maps of the contact between the Hanford Fine unit and the underlying Plio/Pleistocene unit and of the contact between the Plio/Pleistocene unit and the underlying caliche layer. These two contacts were determined to be the most likely surfaces to contain the highest concentration CCl{sub 4}. Part two of the interpretation uses the results of the AVO modeling to locate any seismic amplitude anomalies that might be

  10. Non-aqueous heavy oil extraction from oil sand

    Energy Technology Data Exchange (ETDEWEB)

    Bohnert, George [National Nuclear Security Administration (United States)


    The Kansas City plant operated by Honeywell has a long history of working with DOE NNSA on engineering and manufacturing services supporting national security requirements. The plant has developed a non-aqueous method for heavy oil extraction from oil sands. This method is environmentally friendly as it does not use any external body of water, which would normally be contaminated in the conventional method. It is a 2 phase process consisting of terpene, limonene or alpha pinene, and carbon dioxide. The CO2 and terpene phases are both closed loop systems which minimizes material loss. The limonene and alpha pinene are both naturally derived solvents that come from citrus sources or pine trees respectively. Carbon dioxide is an excellent co-solvent with terpene. There is also a possibility for heat loss recovery during the distillation phase. This process produces clean dry sand. Laboratory tests have concluded that this using non-aqueous liquids process works effectively.

  11. Application of non-aqueous solvents to batteries. I Physicochemical properties of propionitrile/water two-phase solvent relevant to zinc-bromine batteries (United States)

    Singh, P.; White, K.; Parker, A. J.


    The properties of bromine/propionitrile solution are investigated with a view to its use as an electrolyte in zinc-bromine batteries which use circulating electrolyte. The solution, which forms a two-phase system with water, has higher conductivity than the oils formed by complexation of bromine with organic salts such as N,N-methoxymethyl methylpiperidinium bromide and N,N-ethyl methylmorpholinium bromide. The activity of bromine in the aqueous phase of the bromine-propionitrile/water, two-phase system is very low; thus, coulombic efficiencies greater than 85 percent are achieved. Zinc-bromine batteries containing this solvent system show good charge/discharge characteristics.

  12. Oxidative Reactions with Nonaqueous Enzymes

    Energy Technology Data Exchange (ETDEWEB)

    Jonathan S. Dordick; Douglas Clark; Brian H Davison; Alexander Klibanov


    The objective of this work is to demonstrate a proof-of-concept of enzymatic oxidative processing in nonaqueous media using alkene epoxidation and phenolic polymerization as relevant targets. This project will provide both the fundamental and applied investigations necessary to initiate the implementation of oxidative biocatalysts as commercially relevant alternatives to chemical processing in general, and to phenolic polymerizations and alkene epoxidation specifically. Thus, this work will address the Bioprocessing Solicitation Area to: (1) makes major improvements to phenolic polymerization and alkene epoxidation technologies; (2) is expected to be cost competitive with competing conventional processes; and (3) produces higher yields with less waste.

  13. Young's modulus and residual stress of GeSbTe phase-change thin films

    NARCIS (Netherlands)

    Nazeer, H.; Bhaskaran, Harish; Woldering, L.A.; Abelmann, Leon


    The mechanical properties of phase change materials alter when the phase is transformed. In this paper, we report on experiments that determine the change in crucial parameters such as Young's modulus and residual stress for two of the most widely employed compositions of phase change films,

  14. One-Step Nonaqueous Synthesis of Pure Phase TiO2 Nanocrystals from TiCl4 in Butanol and Their Photocatalytic Properties

    Directory of Open Access Journals (Sweden)

    Tieping Cao


    Full Text Available Pure phase TiO2 nanomaterials were synthesized by an autoclaving treatment of TiCl4 with butanol as a single alcohol source. It was found that the control of molar ratio of TiCl4 to butanol played an important role in determining the TiO2 crystal phase and morphology. A high molar ratio of TiCl4 to butanol favored the formation of anatase nanoparticles, whereas rutile nanorods were selectively obtained at a low molar ratio of TiCl4 to butanol. Evaluation of the photocatalytic activity of the synthesized TiO2 was performed in terms of decomposition of organic dye rhodamine B under ultraviolet irradiation. It turned out that the as-synthesized TiO2 crystallites possessed higher photocatalytic activities toward bleaching rhodamine B than Degussa P25, benefiting from theirhigh surface area, small crystal size as well as high crystallinity.

  15. Music emotion recognition: The combined evidence of MFCC and residual phase

    Directory of Open Access Journals (Sweden)

    N.J. Nalini


    Full Text Available The proposed work combines the evidence from mel frequency cepstral coefficients (MFCC and residual phase (RP features for emotion recognition in music. Emotion recognition in music considers the emotions namely anger, fear, happy, neutral and sad. Residual phase feature is an excitation source feature and it is used to exploit emotion specific information present in music signal. The residual phase is defined as the cosine of the phase function of the analytic signal derived from the linear prediction (LP residual and also it is demonstrated that the residual phase signal contains emotion specific information that is complementary to the MFCC features. MFCC and residual phase features are used to create separate models for each emotion. The evidence from the models is combined at the score level for each emotion and it is used to recognize the emotion. The proposed method is evaluated using music files recorded from various websites and the method achieves a performance of 96.0%, 99.0%, 95.0% using AANN, SVM, RBFNN, respectively.

  16. Processes controlling the migration and biodegradation of non-aqueous phase liquids (NAPLs) within fractured rocks in the vadose zone. FY96 annual report

    International Nuclear Information System (INIS)

    Geller, J.T.; Holman, H.Y.; Conrad, M.; Pruess, K.; Hunter-Cevera, J.C.; Su, G.


    This project investigates both flow dynamics and microbial processes affecting NAPLs in fractured rock in a closely coupled, integrated manner. The objective is to develop a qualitative and quantitative understanding of the behavior of two and three immiscible fluid phases, microbial transformation and/or degradation, and to provide a scientific basis for field investigations, site characterization, and remedial action for NAPL contamination in fractured rocks. To achieve this, the program combines laboratory and theoretical investigations, coupled with the evaluation of conditions at relevant field sites. This report summarizes the work accomplished since inception of the project in April 1996

  17. Processes controlling the migration and biodegradation of non-aqueous phase liquids (NAPLs) within fractured rocks in the vadose zone. FY96 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Geller, J.T.; Holman, H.Y.; Conrad, M.; Pruess, K.; Hunter-Cevera, J.C. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.; Su, G. [Univ. of California, Berkeley, CA (United States). Dept. of Civil Engineering


    This project investigates both flow dynamics and microbial processes affecting NAPLs in fractured rock in a closely coupled, integrated manner. The objective is to develop a qualitative and quantitative understanding of the behavior of two and three immiscible fluid phases, microbial transformation and/or degradation, and to provide a scientific basis for field investigations, site characterization, and remedial action for NAPL contamination in fractured rocks. To achieve this, the program combines laboratory and theoretical investigations, coupled with the evaluation of conditions at relevant field sites. This report summarizes the work accomplished since inception of the project in April 1996.

  18. Non-aqueous cleaning solvent substitution (United States)

    Meier, Gerald J.


    A variety of environmental, safety, and health concerns exist over use of chlorinated and fluorinated cleaning solvents. Sandia National Laboratories, Lawrence Livermore National Laboratories, and the Kansas City Division of AlliedSignal have combined efforts to focus on finding alternative cleaning solvents and processes which are effective, environmentally safe, and compliant with local, state, and federal regulations. An alternative solvent has been identified, qualified, and implemented into production of complex electronic assemblies, where aqueous and semi-aqueous cleaning processes are not allowed. Extensive compatibility studies were performed with components, piece-parts, and materials. Electrical testing and accelerated aging were used to screen for detrimental, long-term effects. A terpene, d-limonene, was selected as the solvent of choice, and it was found to be compatible with the components and materials tested. A brief history of the overall project will be presented, along with representative cleaning efficiency results, compatibility results, and residual solvent data. The electronics industry is constantly searching for proven methods and environmentally-safe materials to use in manufacturing processes. The information in this presentation will provide another option to consider on future projects for applications requiring high levels of quality, reliability, and cleanliness from non-aqueous cleaning processes.

  19. Review on mechanisms and continuum models of multi-phase transport phenomena in porous structures of non-aqueous Li-Air batteries (United States)

    Yuan, Jinliang; Yu, Jong-Sung; Sundén, Bengt


    During recent years intensive research activities involving both experimental and modeling approaches have appeared for different aspects of Lithium-air (Li-air) battery. Multi-phase transport phenomena including dissolved oxygen and lithium ions (Li+) in the liquid electrolyte, as well as electrons in the solid materials, are strongly coupled with the porous structures and various reactions, particularly the solid product grown in the porous cathode during battery discharge. Understanding the mechanisms of transport phenomena and accurate evaluation of effective transport properties are significant for improving the battery capacities and design, especially at high rate conditions. In this paper, the transport governing equations commonly used for macroscopic continuum models at porous-average level are outlined and highlighted, with a purpose to provide a general overview of the validity and the limitation of these approaches. The most often used models in the open literature are reviewed and discussed focusing on the effective properties involving tortuosity factors, solid product morphologies, as well as effects on the void space clogging, surface area reduction and passivation. Comments and suggestions are also provided for better understanding of multi-phase transport phenomena and implementation of the detailed models for solid product generation and morphology growth in Li-air battery cathodes.

  20. A method to evaluate residual phase error for polar formatted synthetic aperture radar systems (United States)

    Musgrove, Cameron; Naething, Richard


    Synthetic aperture radar systems that use the polar format algorithm are subject to a focused scene size limit inherent to the polar format algorithm. The classic focused scene size limit is determined from the dominant residual range phase error term. Given the many sources of phase error in a synthetic aperture radar, a system designer is interested in how much phase error results from the assumptions made with the polar format algorithm. Autofocus algorithms have limits to the amount and type of phase error that can be corrected. Current methods correct only one or a few terms of the residual phase error. A system designer needs to be able to evaluate the contribution of the residual or uncorrected phase error terms to determine the new focused scene size limit. This paper describes a method to estimate the complete residual phase error, not just one or a few of the dominant residual terms. This method is demonstrated with polar format image formation, but is equally applicable to other image formation algorithms. A benefit for the system designer is that additional correction terms can be added or deleted from the analysis as necessary to evaluate the resulting effect upon image quality.

  1. Avaliação do desempenho de surfactantes para a solubilização de fases líquidas não aquosas em meio aquoso Evaluating surfactant performance as solubilizer of non-aqueous phase liquids within aqueous media

    Directory of Open Access Journals (Sweden)

    Elizabeth Fátima de Souza


    Full Text Available The presence of non-aqueous phase liquids (NAPLs in the subsurface is a threat to public health as well as a serious environmental issue. NAPLs may remain adsorbed or form lenses floating on aquifers causing long-term contaminations. Surfactants may increase NAPLs solubility, enhancing the pump-and-treatment performance. Size, shape, hydration and ionization degree of the micelles define the affinity and the space available for the solubilization of a particular contaminating agent. The tests carried out at laboratory scale, taking into account the NAPL to be removed and the medium characteristics were useful to select surfactants and evaluate their efficiency as NAPLs solubilizers.

  2. Characterization of asphaltenes by nonaqueous capillary electrophoresis

    NARCIS (Netherlands)

    Kok, W.T.; Tüdös, A.J.; Grutters, M.; Shepherd, A.G.


    Nonaqueous capillary electrophoresis was used for the separation and characterization of asphaltene samples from different sources. For the separation medium (background electrolyte), mixtures of tetrahydrofuran and a high-permittivity organic solvent could be used. The best results were obtained

  3. Residual stress delaying phase transformation in Y-TZP bio-restorations (United States)

    Allahkarami, Masoud; Hanan, Jay C.


    Engineering favorable residual stress for the complex geometry of bi-layer porcelain-zirconia crowns potentially prevents crack initiation and improves the mechanical performance and lifetime of the dental restoration. In addition to external load, the stress field depends on initial residual stress before loading. Residual stress is the result of factors such as the thermal expansion mismatch of layers and compliance anisotropy of zirconia grains in the process of sintering and cooling. Stress induced phase transformation in zirconia extensively relaxes the residual stress and changes the stress state. The objective of this study is to investigate the coupling between tetragonal to monoclinic phase transformations and residual stress. Residual stress, on the surface of the sectioned single load to failure crown, at 23 points starting from the pure tetragonal and ending at a fully monoclinic region were measured using the micro X-ray diffraction sin2 ψ method. An important observation is the significant range in measured residual stress from a compressive stress of -400 MPa up to tensile stress of 400 MPa and up to 100% tetragonal to monoclinic phase transformation.

  4. Enzyme Stability and Activity in Non-Aqueous Reaction Systems: A Mini Review

    Directory of Open Access Journals (Sweden)

    Shihui Wang


    Full Text Available Enormous interest in biocatalysis in non-aqueous phase has recently been triggered due to the merits of good enantioselectivity, reverse thermodynamic equilibrium, and no water-dependent side reactions. It has been demonstrated that enzyme has high activity and stability in non-aqueous media, and the variation of enzyme activity is attributed to its conformational modifications. This review comprehensively addresses the stability and activity of the intact enzymes in various non-aqueous systems, such as organic solvents, ionic liquids, sub-/super-critical fluids and their combined mixtures. It has been revealed that critical factors such as Log P, functional groups and the molecular structures of the solvents define the microenvironment surrounding the enzyme molecule and affect enzyme tertiary and secondary structure, influencing enzyme catalytic properties. Therefore, it is of high importance for biocatalysis in non-aqueous media to elucidate the links between the microenvironment surrounding enzyme surface and its stability and activity. In fact, a better understanding of the correlation between different non-aqueous environments and enzyme structure, stability and activity can contribute to identifying the most suitable reaction medium for a given biotransformation.

  5. Residual stress evaluation of quenched steel by neutron diffraction measurement and phase transformation analysis

    International Nuclear Information System (INIS)

    Mukai, Ryuji; Ju, Dong Yong; Minakawa, Nobuaki; Morii, Yukio; Moriai, Atsushi


    Neutron diffraction method is employed to measure the residual stress inside of quenched steel. To determine the residual stress, it is necessary to know the non-distortion lattice spacing and elastic constant of the material depending on gradient distribution of microstructure and carbon content. In this paper, metallo-thermo-mechanical simulation by finite element method is performed to estimate the distribution of martensite phase and carbon content. Non-distortion lattice spacing. Young's modulus and Poisson's ratio were measured in order to measure the residual stress of test piece of quenching. These values are decided by the distribution of carbon content and marten-site phase. After that, the residual stresses in cylinder specimen of quenched S45C and SCr420 steel are measured by the neutron diffraction method. In addition, the measured results of XRD, neutron diffraction as well as calculated value are compared and discussed. As the result, the non-distortion lattice spacing depend on martensite phase are verified. It is feasible to evaluate the residual stress inside of the quenching material combing with measured results and simulation values. (author)


    Directory of Open Access Journals (Sweden)

    Silas R. Ferreira


    Full Text Available Asphaltenes are blamed for various problems in the petroleum industry, especially formation of solid deposits and stabilization of water-in-oil emulsions. Many studies have been conducted to characterize chemical structures of asphaltenes and assess their phase behavior in crude oil or in model-systems of asphaltenes extracted from oil or asphaltic residues from refineries. However, due to the diversity and complexity of these structures, there is still much to be investigated. In this study, asphaltene (subfractions were extracted from an asphaltic residue (AR02, characterized by NMR, elemental analysis, X-ray fluorescence and MS-TOF, and compared to asphaltene subfractions obtained from another asphaltic residue (AR01 described in a previous article. The (subfractions obtained from the two residues were used to prepare model-systems containing 1 wt% of asphaltenes in toluene and their phase behavior was evaluated by measuring asphaltene precipitation onset using optical microscopy. The results obtained indicated minor differences between the asphaltene fractions obtained from the asphaltic residues of distinct origins, with respect to aromaticity, elemental composition (CHN, presence and content of heteroelements and average molar mass. Regarding stability, minor differences in molecule polarity appear to promote major differences in the phase behavior of each of the asphaltene fractions isolated.

  7. Local residue coupling strategies by neural network for InSAR phase unwrapping (United States)

    Refice, Alberto; Satalino, Giuseppe; Chiaradia, Maria T.


    Phase unwrapping is one of the toughest problems in interferometric SAR processing. The main difficulties arise from the presence of point-like error sources, called residues, which occur mainly in close couples due to phase noise. We present an assessment of a local approach to the resolution of these problems by means of a neural network. Using a multi-layer perceptron, trained with the back- propagation scheme on a series of simulated phase images, fashion the best pairing strategies for close residue couples. Results show that god efficiencies and accuracies can have been obtained, provided a sufficient number of training examples are supplied. Results show that good efficiencies and accuracies can be obtained, provided a sufficient number of training examples are supplied. The technique is tested also on real SAR ERS-1/2 tandem interferometric images of the Matera test site, showing a good reduction of the residue density. The better results obtained by use of the neural network as far as local criteria are adopted appear justified given the probabilistic nature of the noise process on SAR interferometric phase fields and allows to outline a specifically tailored implementation of the neural network approach as a very fast pre-processing step intended to decrease the residue density and give sufficiently clean images to be processed further by more conventional techniques.

  8. Appendix to the report from the low-residue soldering task force: Phase 2 results

    Energy Technology Data Exchange (ETDEWEB)

    Iman, R.L.; Anderson, D.J.; Huffman, D.D. [and others


    The LRSTF report for Phase I of its evaluation of low-residue soldering was issued in June 1995. This Appendix summarizes the results of follow-on testing performed in Phase II and compares electrical test results for both phases. Deliberate decisions were made by the LRSTF in Phase I to challenge the design guideline limits in MILSTD-275, Printed Wiring for Electronic Equipment The LRSTF considered this approach to produce a ``worst case`` design and provide useful information about the robustness of LR soldering processes. As such, good design practices were sometimes deliberately violated in designing the LRSTF board. This approach created some anomalies for both LR boards and RMA/cleaned controls. Phase II testing verified that problems that affected both RMA/cleaned and LR boards in Phase I were design related.

  9. Silica phases in sinters and residues from geothermal fields of New Zealand (United States)

    Rodgers, K. A.; Browne, P. R. L.; Buddle, T. F.; Cook, K. L.; Greatrex, R. A.; Hampton, W. A.; Herdianita, N. R.; Holland, G. R.; Lynne, B. Y.; Martin, R.; Newton, Z.; Pastars, D.; Sannazarro, K. L.; Teece, C. I. A.


    Five silica phases are major components of silica sinters, deposited from both near-neutral pH alkali-chloride and acid-sulfate thermal waters, and of silica residues formed at the surface of geothermal fields in New Zealand. In all cases, the initial silica is noncrystalline opal-A deposited commonly as microspheres that possess an underlying nanospherical substructure, upon different substrate templets, including microbes living in hot springs. Deposition may also occur monomerically upon earlier deposited silica. Following microsphere growth through Ostwald ripening, silica remains mobile throughout the postdepositional history of the sinter/residue deposits, resulting in a range of textures. These include the continuing growth of microspheres, the development of secondary microspheres and silica coatings, phase transformations, a reduction in sinter porosity, dissolution features, and late-stage deposition of drusy quartz and opal-A. The sinter mass attempts to achieve thermodynamic equilibrium through stepwise phase transformations (maturation): opal-A crystallises to paracrystalline opal-CT±opal-C, which recrystallises to microcrystalline α-quartz+moganite. No intermediate silica phases are produced, but gradual changes occur among different opal-A or opal-CT/-C phases. The phase maturation produces changes in particle densities, silanol water, and in X-ray powder response of the different silica phases, although the rates of change can be perturbed by heating, weathering, and dissolution of the sinter/residue. The properties of opal-A change little in a sinter/residue mass within the first 10,000 years, but reductions occur in the densities, silanol water, and X-ray scattering bandwidth of older sinters where opal-A can persist for up to 100,000 years. Eventually, opal-A transforms to opal-CT when silanol water is reduced sufficiently for enough -Si-O-Si- linkages to produce a crude diffraction-like X-ray response. The transformation is aided by heat, as

  10. On the extension of multi-phase models to sub-residual saturations

    International Nuclear Information System (INIS)

    Lingineni, S.; Chen, Y.T.; Boehm, R.F.


    This paper focuses on the limitations of applying multi-phase flow and transport models to simulate the hydrothermal processes occurring when the liquid saturation falls below residual levels. A typical scenario of a heat-generating high-level waste package emplaced in a backfilled drift of a waste repository is presented. The hydrothermal conditions in the vicinity of the waste package as well as in the far-field are determined using multi-phase, non-isothermal codes such as TOUGH2 and FEHM. As the waste package temperature increases, heat-pipe effects are created and water is driven away from the package into colder regions where it condenses. The variations in the liquid saturations close to the waste package are determined using these models with extended capillary pressure-saturations relationships to sub-residual regime. The predictions indicate even at elevated temperatures, waste package surroundings are not completely dry. However, if transport based modeling is used to represent liquid saturation variations in the sub-residual regime, then complete dry conditions are predicted within the backfill for extended periods of time. The relative humidity conditions near the waste package are also found to be sensitive to the representation of capillary pressure-saturation relationship used for sub-residual regime. An experimental investigation is carried out to study the variations in liquid saturations and relative humidity conditions in sub-residual regimes. Experimental results indicated that extended multi-phase models without interphase transport can not predict dry-out conditions and the simulations underpredict the humidity conditions near the waste package

  11. Tensile Residual Stress Mitigation Using Low Temperature Phase Transformation Filler Wire in Welded Armor Plates

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Zhili [ORNL; Bunn, Jeffrey R [ORNL; Tzelepis, Demetrios A [ORNL; Payzant, E Andrew [ORNL; Yu, Xinghua [ORNL


    Hydrogen induced cracking (HIC) has been a persistent issue in welding of high-strength steels. Mitigating residual stresses is one of the most efficient ways to control HIC. The current study develops a proactive in-process weld residual stress mitigation technique, which manipulates the thermal expansion and contraction sequence in the weldments during welding process. When the steel weld is cooled after welding, martensitic transformation will occur at a temperature below 400 C. Volume expansion in the weld due to the martensitic transformation will reduce tensile stresses in the weld and heat affected zone and in some cases produce compressive residual stresses in the weld. Based on this concept, a customized filler wire which undergoes a martensitic phase transformation during cooling was developed. The new filler wire shows significant improvement in terms of reducing the tendency of HIC in high strength steels. Bulk residual stress mapping using neutron diffraction revealed reduced tensile and compressive residual stresses in the welds made by the new filler wire.

  12. Fast thermal annealing of implantation defects in silicon. Solid phase epitaxy and residual imperfection recovery

    International Nuclear Information System (INIS)

    Adekoya, O.A.


    Basic processes ruling the crystal reconstitution in solid phase during fast thermal annealing are studied; the role of electronic and thermodynamic effects at the interface is precised, following the implantations of a donor element (p + ), an acceptor element (B + ) and an intrinsic element (Ge + ). Then, after recrystallization, the electric role of residual point defects is shown together with the possibility of total recovery and an important electric activation of the doping [fr

  13. Comparison of Various Types of Stationary Phases in Non-Aqueous Reversed-Phase High-Performance Liquid Chromatography–Mass Spectrometry of Glycerolipids in Blackcurrant Oil and Its Enzymatic Hydrolysis Mixture

    Czech Academy of Sciences Publication Activity Database

    Lísa, M.; Holčapek, M.; Sovová, Helena


    Roč. 1216, č. 47 (2009), s. 8371-8378 ISSN 0021-9673 Institutional research plan: CEZ:AV0Z40720504 Keywords : ultra high-performance liquid chromatography * C30 stationary phase * triacylglycerols Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.101, year: 2009

  14. Poly(isobutylene) nanoparticles via cationic polymerization in nonaqueous emulsions. (United States)

    Schuster, Thomas; Golling, Florian E; Krumpfer, Joseph W; Wagner, Manfred; Graf, Robert; Alsaygh, Abdulhamid A; Klapper, Markus; Müllen, Klaus


    The preparation of poly(isobutylene) (PIB) nanoparticles via cationic emulsion polymerization is presented. As a requirement, an oil-in-perfluoroalkane nonaqueous emulsion is developed, which is inert under the carbocationic polymerization conditions. To stabilize the dichloromethane/hexane droplets in the fluorinated, continuous phase, an amphiphilic block copolymer emulsifier is prepared containing PIB and 1H,1H-perfluoroalkylated poly(pentafluorostyrene) blocks. This system allows for the polymerization of isobutylene with number-average molecular weights (Mn) up to 27,000 g mol(-1). The particle morphologies are characterized via dynamic light scattering and electron microscopy. For Mn > 20,000 g mol(-1), the particles exhibit shape-persistence at room temperature and are ≈100 nm in diameter. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. On the phase characterization of the residues of the plant Comandante Pedro Soto Alba

    International Nuclear Information System (INIS)

    Diaz Ruano, A.; Fernandez Miranda, J.


    It has been studied of the phases present in the solid industrial residues of the plant Comandante Pedro Soto Alba (Moas's tails). It is done a preliminary qualitative characterization by X ray diffraction. It is done a characterization by differential and gravimetric thermal analysis and a quantitative valuation of SO 3 and H 2 O present in the samples. A complex of S and Al is detected. The results of SO 3 are compared with those obtained by the gravimetric method to verify those of Al, an elemental analysis by neutron activation was solicitated. A formula for the complex of S and Al is proposed. (author)

  16. Wide-band residual phase-noise measurements on 40-GHz monolithic mode-locked lasers

    DEFF Research Database (Denmark)

    Larsson, David; Hvam, Jørn Märcher


    We have performed wide-band residual phase-noise measurements on semiconductor 40-GHz mode-locked lasers by employing electrical waveguide components for the radio-frequency circuit. The intrinsic timing jitters of lasers with one, two, and three quantum wells (QW) are compared and our design...... prediction, concerning noise versus number of QWs, for the first time corroborated by experiments. A minimum jitter of 44 fs is found, by extrapolating to the Nyquist frequency, for the one-QW device having nearly transform-limited pulses of 1.2 ps. This jitter is nearly three times lower than for a three...

  17. Parboiled rice bran in japanese quail diets at growing phase and residual effect at laying period

    Directory of Open Access Journals (Sweden)

    Ednardo Rodrigues Freitas


    Full Text Available Rice is the second largest cereal crop in the world and the by-products resulting from rice processing for human consumption are potential feedstuffs to compose poultry diets. In this sense, it was evaluated the influence of parboiled rice bran (PRB in diets for Japanese quails in growing phase on the performance and digestibility, besides of residual effects and characteristics of egg quality in laying phase. A total of 324 Japanese quails with 7 days of age were distributed in a completely randomized design, with 6 treatments and 6 replicates of 9 birds. The treatments consisted of 6 isonutritives diets, being a control diet without PRB and the others containing 5, 10, 15, 20 and 25%. At the end of growing phase the birds were allotted in cages and fed the same diet without PRB at laying phase. At growing phase, the inclusion of PRB up to 5% promoted linear reduction in dry matter and gross energy digestibilities of diet; however a linear increase in metabolizable energy was noted. Feed intake, weight gain and final weight were reduced but not altering feed:gain ratio and body composition. At laying phase, the inclusion of PRB increased the age at first egg production but no influence was verified at age to reach 50% of egg production. No effect was verified at laying percentage, feed intake, weight and egg mass and feed:gain ratio. In economical evaluation, the inclusion of up to 25% of parboiled rice bran provided best economical indexes. The inclusion of PRB Japanese quails diets at growing phase can be recommended in levels up to 25%, without incurring future losses at laying phase.

  18. Processing of removed Scholven residue in liquid phase at 600 atm

    Energy Technology Data Exchange (ETDEWEB)



    This report listed data of the preliminary hydrogenation and gasolinification of anhydrogenous and phenol-less S-middle oil obtained from processing Scholven residue in liquid phase. A petrol was produced, at 250 atm with catalyst 8376/6434, that had practically the same naphthene. It had a slightly higher aromatic content than compound petrol obtained from the preliminary hydrogenation and gasolinification step (8376/6434) of the processing of Scholven S-middle oil. This petrol's octane number was 1.5 units higher than that of the compound petrol. Comments point out that the difference was more noticeable when the associated liquid-phase petrols were mixed. The report then described the process in detail, including a table with all the relevant data. 1 table.

  19. Anaerobic digestion of onion residuals using a mesophilic Anaerobic Phased Solids Digester

    International Nuclear Information System (INIS)

    Romano, Rowena T.; Zhang, Ruihong


    The anaerobic digestion of onion residual from an onion processing plant was studied under batch-fed and continuously-fed mesophilic (35 ± 2 o C) conditions in an Anaerobic Phased Solids (APS) Digester. The batch digestion tests were performed at an initial loading of 2.8 gVS L -1 and retention time of 14 days. The biogas and methane yields, and volatile solids reduction from the onion residual were determined to be 0.69 ± 0.06 L gVS -1 , 0.38 ± 0.05 L CH 4 gVS -1 , and 64 ± 17%, respectively. Continuous digestion tests were carried out at organic loading rates (OLRs) of 0.5-2.0 gVS L -1 d -1 . Hydrated lime (Ca(OH) 2 ) was added to the APS-Digester along with the onion residual at 16 mg Ca(OH) 2 gVS -1 to control the pH of the biogasification reactor above 7.0. At steady state the average biogas yields were 0.51, 0.56, and 0.62 L gVS -1 for the OLRs of 0.5, 1.0, and 2.0 gVS L -1 d -1 respectively. The methane yields at steady state were 0.29, 0.32, and 0.31 L CH 4 gVS -1 for the OLRs of 0.5, 1.0, and 2.0 gVS L -1 d -1 respectively. The study shows that the digestion of onion residual required proper alkalinity and pH control, which was possible through the use of caustic chemicals. However, such chemicals will begin to have an inhibitory effect on the microbial population at high loading rates, and therefore alternative operational parameters are needed. -- Highlights: → An APS-Digester was used to study biogas production from onion solid residues. → Biogas and methane yields from onion solids were determined. → Study showed substantial findings for treating onion solid residues.

  20. Co-composting of Non-aqueous Drilling Fluid Contaminated ...

    African Journals Online (AJOL)

    Drill cuttings (from Ologbo active oil field) contaminated with non-aqueous drilling fluid was co-composted with poultry manure and plant waste for eighteen weeks. A homogenized non-aqueous based fluid contaminated cutting was mixed with wood chips in a ratio of 1:1 and then mixed with soil, poultry and plant waste ...


    Reavis, J.G.; Leary, J.A.; Walsh, K.A.


    A method is presented for obtaining non-aqueous solutions or plutonium from massive forms of the metal. In the present invention massive plutonium is added to a salt melt consisting of 10 to 40 weight per cent of sodium chloride and the balance zinc chloride. The plutonium reacts at about 800 deg C with the zinc chloride to form a salt bath of plutonium trichloride, sodium chloride, and metallic zinc. The zinc is separated from the salt melt by forcing the molten mixture through a Pyrex filter.

  2. Non-aqueous titration of hydroxamic acids. (United States)

    Stamey, T W; Christian, R


    Benzohydroxamic acid is titrated with 0.1M tetrabutyl-anunonium hydroxide in nine non-aqueous solvents with three different indicating electrodes. The best results are obtained using dimethylformamide as solvent and platinum-platinum electrodes. Four monoprotic and three diprotic hydroxamie acids and iron(III) benzohydroxamate have been successfully titrated with this system. The effect of quantitative additions of carbon dioxide to the titrant on its apparent molarity are found to be dependent on the amount added, the strength and sample size of acid titrated and the solvent used.

  3. Chemical composition and mixing-state of ice residuals sampled within mixed phase clouds

    Directory of Open Access Journals (Sweden)

    M. Ebert


    Full Text Available During an intensive campaign at the high alpine research station Jungfraujoch, Switzerland, in February/March 2006 ice particle residuals within mixed-phase clouds were sampled using the Ice-counterflow virtual impactor (Ice-CVI. Size, morphology, chemical composition, mineralogy and mixing state of the ice residual and the interstitial (i.e., non-activated aerosol particles were analyzed by scanning and transmission electron microscopy. Ice nuclei (IN were identified from the significant enrichment of particle groups in the ice residual (IR samples relative to the interstitial aerosol. In terms of number lead-bearing particles are enriched by a factor of approximately 25, complex internal mixtures with silicates or metal oxides as major components by a factor of 11, and mixtures of secondary aerosol and carbonaceous material (C-O-S particles by a factor of 2. Other particle groups (sulfates, sea salt, Ca-rich particles, external silicates observed in the ice-residual samples cannot be assigned unambiguously as IN. Between 9 and 24% of all IR are Pb-bearing particles. Pb was found as major component in around 10% of these particles (PbO, PbCl2. In the other particles, Pb was found as some 100 nm sized agglomerates consisting of 3–8 nm sized primary particles (PbS, elemental Pb. C-O-S particles are present in the IR at an abundance of 17–27%. The soot component within these particles is strongly aged. Complex internal mixtures occur in the IR at an abundance of 9–15%. Most IN identified at the Jungfraujoch station are internal mixtures containing anthropogenic components (either as main or minor constituent, and it is concluded that admixture of the anthropogenic component is responsible for the increased IN efficiency within mixed phase clouds. The mixing state appears to be a key parameter for the ice nucleation behaviour that cannot be predicted from the sole knowledge of the main component of an individual particle.

  4. Hg and Pt-metals in meteorite carbon-rich residues - Suggestions for possible host phase for Hg (United States)

    Jovanovic, S.; Reed, G. W., Jr.


    Carbon-rich and oxide residual phases have been isolated from Allende and Murchison by acid demineralization for the determination of their Hg, Pt-metal, Cr, Sc, Co, and Fe contents. Experimental procedures used eliminated the possibility of exogenous and endogenous contaminant trace elements from coprecipitating with the residues. Large enrichments of Hg and Pt-metals were found in Allende but not in Murchison residues. Hg-release profiles from stepwise heating experiments suggest a sulfide as the host for Hg. Diffusion calculations for Hg based on these experiments indicate an activation energy of 7-8 kcal/mol, the same as that for Hg in troilite from an iron meteorite. This is further support for a sulfide host phase for Hg. Equilibration of Hg with this phase at approximately 900 K is indicated. Reasons for the presence of Pt-metals in noncosmic relative abundances are explored.

  5. Non-polar lipids characterization of Quinoa (Chenopodium quinoa) seed by comprehensive two-dimensional gas chromatography with flame ionization/mass spectrometry detection and non-aqueous reversed-phase liquid chromatography with atmospheric pressure chemical ionization mass spectrometry detection. (United States)

    Fanali, Chiara; Beccaria, Marco; Salivo, Simona; Tranchida, Peter; Tripodo, Giusy; Farnetti, Sara; Dugo, Laura; Dugo, Paola; Mondello, Luigi


    A chemical characterization of major lipid components, namely, triacylglycerols, fatty acids and the unsaponifiable fraction, in a Quinoa seed lipids sample is reported. To tackle such a task, non-aqueous reversed-phase high-performance liquid chromatography with mass spectrometry detection was employed. The latter was interfaced with atmospheric pressure chemical ionization for the analysis of triacylglycerols. The main triacylglycerols (>10%) were represented by OLP, OOL and OLL (P = palmitoyl, O = oleoyl, L = linoleoyl); the latter was present in the oil sample at the highest percentage (18.1%). Furthermore, fatty acid methyl esters were evaluated by gas chromatography with flame ionization detection. 89% of the total fatty acids was represented by unsaturated fatty acid methyl esters with the greatest percentage represented by linoleic and oleic acids accounting for approximately 48 and 28%, respectively. An extensive characterization of the unsaponifiable fraction of Quinoa seed lipids was performed for the first time, by using comprehensive two-dimensional gas chromatography with dual mass spectrometry/flame ionization detection. Overall, 66 compounds of the unsaponifiable fraction were tentatively identified, many constituents of which (particularly sterols) were confirmed by using gas chromatography with high-resolution time-of-flight mass spectrometry. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. A method for assessing residual NAPL based on organic chemical concentrations in soil samples

    International Nuclear Information System (INIS)

    Feenstra, S.; Mackay, D.M.; Cherry, J.A.


    Ground water contamination by non-aqueous phase liquid (NAPL) chemicals is a serious concern at many industrial facilities and waste disposal sites. NAPL in the form of immobile residual contamination, or pools of mobile or potentially mobile NAPL, can represent continuing sources of ground water contamination. In order to develop rational and cost-effective plans for remediation of soil and ground water contamination at such sites, it is essential to determine if non-aqueous phase liquid (NAPL) chemicals are present in the subsurface and delineate the zones of NAPL contamination. Qualitatively, soil analyses that exhibit chemical concentrations in the percent range or >10,000 mg/kg would generally be considered to indicate the presence of NAPL. However, the results of soil analyses are seldom used in a quantitative manner to assess the possible presence of residual NAPL contamination when chemical concentrations are lower and the presence of NAPL is not obvious. The assessment of the presence of NAPL in soil samples is possible using the results of chemical and physical analyses of the soil, and the fundamental principles of chemical partitioning in unsaturated or saturated soil. The method requires information on the soil of the type typically considered in ground water contamination studies and provides a simple tool for the investigators of chemical spill and waste disposal sites to assess whether soil chemical analyses indicate the presence of residual NAPL in the subsurface

  7. Chemical composition of ambient aerosol, ice residues and cloud droplet residues in mixed-phase clouds: single particle analysis during the Cloud and Aerosol Characterization Experiment (CLACE 6

    Directory of Open Access Journals (Sweden)

    M. Kamphus


    Full Text Available Two different single particle mass spectrometers were operated in parallel at the Swiss High Alpine Research Station Jungfraujoch (JFJ, 3580 m a.s.l. during the Cloud and Aerosol Characterization Experiment (CLACE 6 in February and March 2007. During mixed phase cloud events ice crystals from 5–20 μm were separated from larger ice aggregates, non-activated, interstitial aerosol particles and supercooled droplets using an Ice-Counterflow Virtual Impactor (Ice-CVI. During one cloud period supercooled droplets were additionally sampled and analyzed by changing the Ice-CVI setup. The small ice particles and droplets were evaporated by injection into dry air inside the Ice-CVI. The resulting ice and droplet residues (IR and DR were analyzed for size and composition by the two single particle mass spectrometers: a custom-built Single Particle Laser-Ablation Time-of-Flight Mass Spectrometer (SPLAT and a commercial Aerosol Time-of-Flight Mass Spectrometer (ATOFMS, TSI Model 3800. During CLACE 6 the SPLAT instrument characterized 355 individual IR that produced a mass spectrum for at least one polarity and the ATOFMS measured 152 IR. The mass spectra were binned in classes, based on the combination of dominating substances, such as mineral dust, sulfate, potassium and elemental carbon or organic material. The derived chemical information from the ice residues is compared to the JFJ ambient aerosol that was sampled while the measurement station was out of clouds (several thousand particles analyzed by SPLAT and ATOFMS and to the composition of the residues of supercooled cloud droplets (SPLAT: 162 cloud droplet residues analyzed, ATOFMS: 1094. The measurements showed that mineral dust was strongly enhanced in the ice particle residues. Close to all of the SPLAT spectra from ice residues did contain signatures from mineral compounds, albeit connected with varying amounts of soluble compounds. Similarly, close to all of the ATOFMS IR spectra show a

  8. Recent developments in nonaqueous plutonium coordination chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gaunt, A.J. [Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico (United States); Neu, M.P. [Associate Directorate for Chemistry, Life, and Earth Sciences, Los Alamos National Laboratory, Los Alamos, New Mexico (United States)


    This account highlights recent research from our laboratory on nonaqueous plutonium coordination chemistry. The preparation of organic-soluble synthons, the reactivity of plutonium with soft donor atom ligands, and initial characterization of resultant complexes are presented. Homoleptic soft donor complexes are targeted, to contrast with the much larger body of actinide chemistry that focuses covalency and reactivity within one to three sites in the coordination sphere. Structural parameters from X-ray structure determination and computation indicate small, yet significant, differences in covalency between isostructural plutonium and lanthanide complexes. Results are discussed in the context of our aim to expand the fundamental chemistry of plutonium, particularly to address challenges in the nuclear industry. (authors)

  9. Phase chemistry of tank sludge residual components. 1998 annual progress report

    International Nuclear Information System (INIS)

    Brady, P.V.; Krumhansl, J.L.; Liu, J.; Nagy, K.L.


    'The proposed research will provide a scientific basis for predicting the long-term fate of radionuclides remaining with the sludge in decommissioned waste tanks. Nuclear activities in the United States and elsewhere produce substantial volumes of highly radioactive semi-liquid slurries that traditionally are stored in large underground tanks while final waste disposal strategies are established. Although most of this waste will eventually be reprocessed a contaminated structure will remain which must either be removed or decommissioned in place. To accrue the substantial savings associated with in-place disposal will require a performance assessment which, in turn, means predicting the leach behavior of the radionuclides associated with the residual sludges. The phase chemistry of these materials is poorly known so a credible source term cannot presently be formulated. Further, handling of actual radioactive sludges is exceedingly cumbersome and expensive. This proposal is directed at: (1) developing synthetic nonradioactive sludges that match wastes produced by the various fuel processing steps, (2) monitoring the changes in phase chemistry of these sludges as they age, and (3) relating the mobility of trace amounts of radionuclides (or surrogates) in the sludge to the phase changes in the aging wastes. This report summarizes work carried out during the first year of a three year project. A prerequisite to performing a meaningful study was to learn in considerable detail about the chemistry of waste streams produced by fuel reprocessing. At Hanford this is not a simple task since over the last five decades four different reprocessing schemes were used: the early BiPO 4 separation for just Pu, the U recovery activity to further treat wastes left by the BiPO 4 activities, the REDOX process and most recently, the PUREX processes. Savannah River fuel reprocessing started later and only PUREX wastes were generated. It is the working premise of this proposal that most

  10. A Nitrogen-concentrated Phase in IA Iron Meteorite Acid Residue (United States)

    Hashizume, K.; Sugiura, N.


    Introduction: Iron meteorites are considered to have experienced a complex history, which is indicated by the variations in trace element chemistry (e.g., [1]). Among iron meteorite groups, the so called nonmagmatic groups, such as IAB, IIE, and IIICD, may have passed through different formation paths compared to others. Nitrogen isotopes can be a useful tool to understand the origin and formation processes of iron meteorites. Nikogen isotopes in a number of iron meteorites are measured [2,3], although trapping sites of nitrogen in iron meteorites are not yet clear. This is an important issue because nitrogen, a typical mobile element, may well reflect thermal history of their parent bodies (c.f., [4]). Generally, a major portion of nitrogen in iron meteorites is expected to be in a solid solution in Fe-Ni, especially in f.c.c. Fe-Ni (taenite). Franchi et al. [3] report that at least 25 to 35% of nitrogen in magmatic iron meteorites is in acid insoluble phases, however, not in those of non-magmatic meteorites. This result contradicts with the result [5] who report that a significant portion of nitrogen seems to be trapped in acid residues not only of magmatic meteorites but also of non- magmatic meteorites. To resolve the contradiction described above, and to identify the trapping site, we started measuring nitrogen isotopes in acid residues of iron metcorites. We report here preliminary results on acid residues of Canyon Diablo (IA). Procedures: Acid residues were prepared by Dr. J.-I. Matsuda and his colleagues. Different blocks of Canyon Diablo, "Can-1" and "Can-2" were treated by 14M HCl, 10M-HF + 1M-HCl, 1M-HCl, and by aqua regia, which destroyed Fe-Ni, sulfides, silicates, and shreibersite. Acid residues of these two blocks, "Can-1bn" and "Can-2b," yielded 0.102 wt% and 0.299 wt% of their original masses, respectively These residues seem to consist mostly of graphite No diamond was detected by powder X-ray analysis [6]. Preliminary Results: A predominant

  11. Simultaneous Determination of TetracyclinesResidues in Bovine Milk Samples by Solid Phase Extraction and HPLC-FL Method

    Directory of Open Access Journals (Sweden)

    Mehra Mesgari Abbasi


    Full Text Available Introduction:Tetracyclines (TCs are widely used in animal husbandry and their residues in milk may resultinharmful effects on human. The aim of this study was to investigate the presence of TCs residues in various bovine milk samples from local markets of Ardabil, Iran. Methods:One hundred and fourteen pasteurized, sterilized and raw milk samples were collected from markets of Ardabil. Tetracycline, Oxytetracycline and Chlortetracycline (TCs residues extraction carried out by Solid Phase Extraction method. Determination of TCs residues were performed by high performance liquid chromatography (HPLC method using Fluorescence detector.Results: The mean of total TCs residues in all samples (114 samples was 97.6 ±16.9ng/g and that of pasteurized, sterilized and raw milk samples were 87.1 ± 17.7, 112.0 ± 57.3 and 154.0 ± 66.3ng/g respectively. Twenty five point four percent of the all samples, and24.4%, 30% and 28.6% of the pasteurized, sterilized and raw milk samples, respectively had higher TCs residues than the recommended maximum levels (100ng/g. Conclusion:This study indicates the presence of tetracycline residues more than allowed amount. Regulatory authorities should ensure proper withdrawal period before milking the animals and definite supervisions are necessary on application of these drugs.

  12. Principles of interactions in non-aqueous electrolyte solutions

    NARCIS (Netherlands)

    Lyklema, J.


    In this paper a review is presented on the molecular interactions in non-aqueous media of low dielectric permittivity. Qualitative and quantitative distinctions with aqueous solutions are emphasized. The reviewed themes include dispersion forces, dissociation and association equilibria,

  13. The use of solid phase extraction method for analysis of residues of pesticides used in banana production in Costa Rica

    International Nuclear Information System (INIS)

    Castillo, L.E.; Ruepert, C.; Alfaro, A.R.; Solis, E.


    Different solid phase extraction devices were tested for the analysis of residues of eleven pesticides used in banana production in Costa Rica. The analysis was performed by using gas chromatograph equipped with NPD and ECD detectors. In general low recoveries and high variation coefficients were found for chlorothalonil, imazalil, terbufos and thiabendazole. For the other pesticides recoveries ranged between 60 and over 100%. (author)

  14. Ice residual properties in mixed-phase clouds at the high-alpine Jungfraujoch site (United States)

    Kupiszewski, Piotr; Zanatta, Marco; Mertes, Stephan; Vochezer, Paul; Lloyd, Gary; Schneider, Johannes; Schenk, Ludwig; Schnaiter, Martin; Baltensperger, Urs; Weingartner, Ernest; Gysel, Martin


    Ice residual (IR) and total aerosol properties were measured in mixed-phase clouds (MPCs) at the high-alpine Jungfraujoch research station. Black carbon (BC) content and coating thickness of BC-containing particles were determined using single-particle soot photometers. The ice activated fraction (IAF), derived from a comparison of IR and total aerosol particle size distributions, showed an enrichment of large particles in the IR, with an increase in the IAF from values on the order of 10-4 to 10-3 for 100 nm (diameter) particles to 0.2 to 0.3 for 1 μm (diameter) particles. Nonetheless, due to the high number fraction of submicrometer particles with respect to total particle number, IR size distributions were still dominated by the submicrometer aerosol. A comparison of simultaneously measured number size distributions of BC-free and BC-containing IR and total aerosol particles showed depletion of BC by number in the IR, suggesting that BC does not play a significant role in ice nucleation in MPCs at the Jungfraujoch. The potential anthropogenic climate impact of BC via the glaciation effect in MPCs is therefore likely to be negligible at this site and in environments with similar meteorological conditions and a similar aerosol population. The IAF of the BC-containing particles also increased with total particle size, in a similar manner as for the BC-free particles, but on a level 1 order of magnitude lower. Furthermore, BC-containing IR were found to have a thicker coating than the BC-containing total aerosol, suggesting the importance of atmospheric aging for ice nucleation.

  15. Nonaqueous Electrolyte Development for Electrochemical Capacitors

    Energy Technology Data Exchange (ETDEWEB)

    K. Xu; S. P. Ding; T. R. Jow


    The objectives of this project were to demonstrate and develop new nonaqueous electrolytes that enable the development of high power (in excess of 2 kW/kg) and high energy (in excess of 8 Wh/kg) capacitors. Electrochemical capacitors are attractive to use because of their long cycle life and inherent high-power (or fast charge/discharge) capabilities. To realize the inherent high-power nature of the capacitor, the resistance of the capacitor needs to be low. The main focus of this project is on the ionic part of capacitor resistance, which is largely determined by the electrolyte, especially the electrolyte's conductivity. To achieve the objectives of this project, two approaches were used. The first was to search for the proper solvent mixtures within the commercially available quaternary ammonium salts such as tetraethyl ammonium tetrafluoroborate (Et4NBF4) or tetraethyl ammonium hexafluorophosphate (Et4NPF6). The second approach was to use the commonly available solvent system s but develop new salts. Substantial advances were made in quaternary ammonium salts and solvent systems were identified that can withstand high voltage operations. However, improvement in the salt alone is not sufficient. Improvements in the low-temperature stability of a capacitor rely not only on the salts but also on the solvents. Likewise, the high-temperature stability of the capacitor will depend not only on the salts but also on the solvents and carbon electrode materials.

  16. Evaluation of nonaqueous processes for nuclear materials

    International Nuclear Information System (INIS)

    Musgrave, B.C.; Grens, J.Z.; Knighton, J.B.; Coops, M.S.


    A working group was assigned the task of evaluating the status of nonaqueous processes for nuclear materials and the prospects for successful deployment of these technologies in the future. In the initial evaluation, the study was narrowed to the pyrochemical/pyrometallurgical processes closely related to the processes used for purification of plutonium and its conversion to metal. The status of the chemistry and process hardware were reviewed and the development needs in both chemistry and process equipment technology were evaluated. Finally, the requirements were established for successful deployment of this technology. The status of the technology was evaluated along three lines: (1) first the current applications were examined for completeness, (2) an attempt was made to construct closed-cycle flow sheets for several proposed applications, (3) and finally the status of technical development and future development needs for general applications were reviewed. By using these three evaluations, three different perspectives were constructed that together present a clear picture of how complete the technical development of these processes are

  17. Nonaqueous liquid-liquid extraction of manganese from ethylene glycol solution with trioctylphosphine oxide

    International Nuclear Information System (INIS)

    Aoki, Toru


    The nonaqueous liquid-liquid extraction of manganese was investigated between the nonpolar solvents (cyclohexane or toluene) containing tri-n-octylphosphine oxide and ethylene glycol containing hydrogen chloride. Manganese was extracted in the two different hydrogen chloride concentration regions in the ethylene glycol phase. One of the manganese extractions was found at the higher hydrogen chloride concentration (above about 10 -2 M), and the extracted from was MnCl 2 .2TOPO. Another was caused at the lower hydrogen chloride concentration (below about 10 -3 M) and the extracted species was presumed to be manganese (deprotonated ethylene glycol) 2 .nTOPO complex. (author)


    Energy Technology Data Exchange (ETDEWEB)

    Duff, M; S Crump, S; Robert02 Ray, R; Donna Beals, D


    The Federal Bureau of Investigation (FBI) Laboratory currently does not have on site facilities for handling radioactive evidentiary materials and there are no established FBI methods or procedures for decontaminating high explosive (HE) evidence while maintaining evidentiary value. One experimental method for the isolation of HE residue involves using solid phase microextraction or SPME fibers to remove residue of interest. Due to their high affinity for organics, SPME fibers should have little affinity for most metals. However, no studies have measured the affinity of radionuclides for SPME fibers. The focus of this research was to examine the affinity of dissolved radionuclide ({sup 239/240}Pu, {sup 238}U, {sup 237}Np, {sup 85}Sr, {sup 133}Ba, {sup 137}Cs, {sup 60}Co and {sup 226}Ra) and stable radionuclide surrogate metals (Sr, Co, Ir, Re, Ni, Ba, Cs, Nb, Zr, Ru, and Nd) for SPME fibers at the exposure conditions that favor the uptake of HE residues. Our results from radiochemical and mass spectrometric analyses indicate these metals have little measurable affinity for these SPME fibers during conditions that are conducive to HE residue uptake with subsequent analysis by liquid or gas phase chromatography with mass spectrometric detection.

  19. Modelling the Effects of Surface Residual Stresses on Fatigue Behavior of PM Disk Alloys, Phase I (United States)

    National Aeronautics and Space Administration — A finite element based model will be developed and validated to capture the evolution of residual stresses and cold work at machined features of compressor and...

  20. Characterizing Phase Transformations and Their Effects on Ferritic Weld Residual Stresses with X-Rays and Neutrons (United States)

    Dai, H.; Francis, J. A.; Stone, H. J.; Bhadeshia, H. K. D. H.; Withers, P. J.


    Weld residual stresses often approach, or exceed, the yield strength of the material, with serious implications for the integrity of engineering structures. It is not always feasible to measure residual stresses, so integrity assessments often rely heavily on numerical models. In ferritic steels, the credibility of such models depends on their ability to account for solid-state phase transformations, which can have a controlling effect on the final residual stress state. Furthermore, a better understanding of weld transformations provides an opportunity to engineer the weld stress state and microstructure for improved life. In this article, the complementary merits of synchrotron X-ray and neutron diffraction are exploited both to verify and refine weld models and to inspire the development of weld filler metals to control weld stresses. In terms of weld filler metal design, X-ray diffraction is used to characterize phase transformations in real time during realistic weld cooling cycles, for understanding small-scale behavior and identifying features that need to be incorporated into finite-element models. Meanwhile, neutron diffraction is used to elucidate the practical consequences of solid-state phase transformations on the macroscopic scale, thereby providing crucial validatory structural integrity data.

  1. Fate of antibiotic and metal resistance genes during two-phase anaerobic digestion of residue sludge revealed by metagenomic approach. (United States)

    Wu, Ying; Cui, Erping; Zuo, Yiru; Cheng, Weixiao; Chen, Hong


    The prevalence and persistence of antibiotic resistance genes in wastewater treatment plants (WWTPs) is of growing interest, and residual sludge is among the main sources for the release of antibiotic resistance genes (ARGs). Moreover, heavy metals concentrated in dense microbial communities of sludge could potentially favor co-selection of ARGs and metal resistance genes (MRGs). Residual sludge treatment is needed to limit the spread of resistance from WWTPs into the environment. This study aimed to explore the fate of ARGs and MRGs during thermophilic two-phase (acidogenic/methanogenic phase) anaerobic digestion by metagenomic analysis. The occurrence and abundance of mobile genetic elements were also determined based on the SEED database. Among the 27 major ARG subtypes detected in feed sludge, large reductions (> 50%) in 6 ARG subtypes were achieved by acidogenic phase (AP), while 63.0% of the ARG subtypes proliferated in the following methanogenic phase (MP). In contrast, a 2.8-fold increase in total MRG abundance was found in AP, while the total abundance during MP decreased to the same order of magnitude as in feed sludge. The distinct dynamics of ARGs and MRGs during the two-phase anaerobic digestion are noteworthy, and more specific treatments are required to limit their proliferation in the environment.

  2. Residual stress induced crystalline to amorphous phase transformation in Nb2O5 quantum dots (United States)

    Dhawan, Sahil; Dhawan, Tanuj; Vedeshwar, Agnikumar G.


    Nb2O5 quantum dots (QDs) were grown using a simple technique of vacuum thermal evaporation. QDs were found to be crystalline in nature by selected area electron diffraction (SAED) in TEM. Samples with thickness up to 20 nm did not show any significant residual strain. Residual stress effect on band gap of crystalline Nb2O5 was studied for films thicker than 20 nm. Residual strain was determined using SAED of the films with reference to powder X-ray diffraction (XRD). Films thicker than 45 nm become amorphous as analyzed by both SAED and XRD. The optical absorption of films in the range 25-60 nm indicates significantly varying optical band gap of films. The varying band gap with film thickness scales linearly very well with the variation of residual stress with film thickness. The residual stress dependence of band gap of crystalline films yields stress free band gap as 3.37 eV with pressure coefficient of band gap (∂Eg/∂P)T = -29.3 meV/GPa. From this study, the crystalline to amorphous transformation in tetragonal form of M-Nb2O5 has been determined to be at about 14 GPa. Both pressure coefficient of band gap and crystalline to amorphous transition for tetragonal M-Nb2O5 have been determined for the first time in the literature.

  3. Recombinant Staphylococcal protein A with cysteine residue for preparation of affinity chromatography stationary phase and immunosensor applications

    Directory of Open Access Journals (Sweden)

    Gorbatiuk O. B.


    Full Text Available Aim. Engineering of recombinant Staphylococcal protein A with cysteine residue (SPA-Cys for preparation of affinity chromatography stationary phase and formation of bioselective element of immunosensor. Methods. DNA sequences encoding IgG-binding region of SPA, His-tag and cysteine were genetically fused and expressed in E. coli. SPA-Cys was immobilized on maleimide-functionalized silica beads for affinity chromatography stationary phase preparation and on a gold sensor surface as a bioselective element of immunosensor. Results. SPA-Cys was expressed at a high-level in a soluble form. The target protein was purified and showed a high IgG-binding activity. The capacity of the obtained SPA-Cys-based affinity chromatography stationary phase was 10–12 mg of IgG /ml. The purity of eluted IgG was more than 95 % in one-step purification procedure. The developed SPA-Cys-based bioselective element of immunosensor selectively interacted with human IgG and did not interact with the control proteins. Conclusions. The recombinant Staphylococcal protein A with cysteine residue was successfully used for the preparation of affinity chromatography stationary phase and formation of the bioselective element of immunosensor.

  4. Characterization of micro-scale residual stress around thermal grown oxide using micro-slotting method and geometric phase analysis (United States)

    Zhang, Q.; Xie, H.; Liu, Z.; Dai, X.


    Characterization of residual stress around thermal grown oxide (TGO) is important for understanding the spallation failure of thermal barrier coatings (TBCs). Cr3+ photoluminescence piezo-spectroscopy (CPLPS) is a nondestructive method for measuring the in-plane residual stress in the TGO layer. However, using CPLPS it is hard to evaluate the out-of-plane residual stress around TGO. Here, we adopted the micro-slotting method combined with geometric phase analysis (GPA) for measuring the in-plane and out-of-plane stresses around TGO, with measured areas of 6  ×  4 µm2. In the experiment, a grating and a slot were milled on the specimen surface using focused ion beam, and GPA was applied to analyze the grating structure before and after the slot milling for calculating the released displacement field. Then finite element analysis was used to infer the residual stress in the direction vertical to the micro-slot. Two experiments were performed on the in-service TBC specimen. The first experiment presented the in-plane compression in the TGO, while the second experiment presented the out-of-plane tension at the crest of the TGO/BC interface, thus validating the theoretical analysis.

  5. Evaluation of phase stresses of Al sub 2 O sub 3 /YAG binary MGC by synchrotron radiation. Residual stress states and stress behavior of YAG phase

    CERN Document Server

    Suzuki, H; Akita, K; Yoshioka, Y; Waku, Y


    Melt Growth Composite material (MGC) consists of multiple single crystal with fine entangled in three dimensional network structures. The MGCs are thermally stable and have higher creep resistance. Furthermore, the flexural strength at room temperature can be maintained almost up to the melting point. In this study, in order to discuss the generation mechanism of residual stress in an Al sub 2 O sub 3 /Y sub 3 Al sub 5 O sub 1 sub 2 (YAG) binary MGC, the residual stresses of YAG phase were measured by X-rays from synchrotron radiation source. We used a method for stress determination of single crystal by using a position sensitive proportional counter (PSPC) system and a specimen-oscillating device. Lattice strains of left brace 4 6 10 right brace in the YAG phase were measured. The residual stresses were from 40 to 120 MPa in tension in the longitudinal direction which corresponds to the solidification direction, 80MPa in compression in the thickness direction, and 70MPa in tension in the width direction. Si...

  6. Phase, Residual Stress, and Texture in Triode-Sputtered Tantalum Coatings on Steel

    National Research Council Canada - National Science Library

    Lee, S


    .... Our phase determination was based on X ray diffraction analysis, wavelength dispersive X ray fluorescence analysis, energy dispersive X ray analysis, and hardness and electrical resistivity measurements...

  7. Synthesis of nanocrystalline mixed metal fluorides in nonaqueous ...

    Indian Academy of Sciences (India)


    Synthesis of nanocrystalline mixed metal fluorides in nonaqueous medium. NEETU TYAGI, EPSITA GHANTI, NIKESH GUPTA, N P LALLA. † and. RAJAMANI NAGARAJAN*. Department of Chemistry, University of Delhi, Delhi 110 007, India. †. Inter University Consortium for DAE Facilities, University Campus, Indore 452 ...

  8. Synthesis of nanocrystalline mixed metal fluorides in nonaqueous ...

    Indian Academy of Sciences (India)


    Abstract. Synthesis of mixed metal fluorides of the general formula, KMF3 (M = Mg, Mn, Co, Ni, Cu and. Zn), possessing perovskite structure was investigated in non-aqueous medium. The fluorides were characte- rized by powder X-ray diffraction, FT–IR spectroscopy, thermal analysis, SEM and TEM. Monophasic cubic.

  9. Simulation investigation of thermal phase transformation and residual stress in single pulse EDM of Ti-6Al-4V (United States)

    Tang, Jiajing; Yang, Xiaodong


    The thermal phase transformation and residual stress are ineluctable in the electrical discharge machining (EDM) process, and they will greatly affect the working performances of the machined surface. This paper presents a simulation study on the thermal phase transformation and residual stress in single-pulse EDM of Ti-6Al-4V, which is the most popular titanium alloy in fields such as aircraft engine and some other leading industries. A multi-physics model including thermal, hydraulic, metallography and structural mechanics was developed. Based on the proposed model, the thickness and metallographic structure of the recast layer and heat affected layer (HAZ) were investigated. The distribution and characteristics of residual stress around the discharge crater were obtained. The recast layer and HAZ at the center of crater are found to be the thinnest, and their thicknesses gradually increase approaching the periphery of the crater. The recast layer undergoes a complete α‧ (martensitic) transformation, while the HAZ is mainly composed by the α  +  β  +  α‧ three-phase microstructure. Along the depth direction of crater, the Von Mises stress increases first and then decreases, reaching its maximal value near the interface of recast layer and HAZ. In the recast layer, both compressive stress component and tensile stress component are observed. ANOVA results showed that the influence of discharge current on maximal tensile stress is more significant than that of pulse duration, while the pulse duration has more significant influence on average thickness of the recast layer and the depth location of the maximal tensile stress. The works conducted in this study will help to evaluate the quality and integrity of EDMed surface, especially when the non-destructive testing is difficult to achieve.

  10. Phase II, Title I engineering assessment of radioactive sands and residues, Lowman Site, Lowman Idaho

    Energy Technology Data Exchange (ETDEWEB)


    An engineering assessment was performed of the problems resulting from the existence of radioactive uranium sand residues at the Lowman, Idaho, site. Services normally include the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and other radium-contaminated materials, the evaluation of resulting investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas release from the 90,000 tons of sand residues at the Lowman site constitutes the most significant environmental impact, although external gamma radiation is also a factor. The two alternative actions presented are dike construction, fencing, and maintenance (Option I); and consolidation of the piles, addition of a 2-ft-thick stabilization cover, and on-site cleanup (Option II). Both options include remedial action at off-site structures. Cost estimates for the two options are $393,000 and $590,000.

  11. Phase II, Title I engineering assessment of radioactive sands and residues, Lowman Site, Lowman Idaho

    International Nuclear Information System (INIS)


    An engineering assessment was performed of the problems resulting from the existence of radioactive uranium sand residues at the Lowman, Idaho, site. Services normally include the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and other radium-contaminated materials, the evaluation of resulting investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas release from the 90,000 tons of sand residues at the Lowman site constitutes the most significant environmental impact, although external gamma radiation is also a factor. The two alternative actions presented are dike construction, fencing, and maintenance (Option I); and consolidation of the piles, addition of a 2-ft-thick stabilization cover, and on-site cleanup (Option II). Both options include remedial action at off-site structures. Cost estimates for the two options are $393,000 and $590,000

  12. Quantitative prediction of residual wetting film generated in mobilizing a two-phase liquid in a capillary model

    Directory of Open Access Journals (Sweden)

    Harsh Joshi


    Full Text Available This research studies the motion of immiscible two-phase liquid flow in a capillary tube through a numerical approach employing the volume of fluid method, for simulating the core-annular flow and water flooding in oil reservoirs of porous media. More specifically, the simulations are a representation of water flooding at a pore scale. A capillary tube model is established with ANSYS Fluent and verified. The numerical results matches well with the existing data available in the literature. Penetration of a less viscous liquid in a liquid of higher viscosity and the development of a residual wetting film of the higher viscosity liquid are thoroughly investigated. The effects of Capillary number, Reynolds Number and Viscosity ratio on the residual wetting film are studied in detail, as the thickness is directly related to the residual oil left in the porous media after water flooding. It should be noticed that the liquids considered in this research can be any liquids of different viscosity not necessarily oil and water. The results of this study can be used as guidance in the field of water flooding.

  13. Basicity comparison for di-substituted 4-nitropyridine derivatives in polar non-aqueous media

    International Nuclear Information System (INIS)

    Gurzynski, Lukasz; Puszko, Aniela; Chmurzynski, Lech


    Acid dissociation, as well as cationic homoconjugation equilibria have been studied potentiometrically in systems involving four di-substituted 4-nitropyridines and conjugate cationic acids in the polar non-aqueous solvents - aprotic protophobic acetonitrile (AN) and propylene carbonate (PC), the amphiprotic methanol (MeOH), and in the aprotic protophilic dimethyl sulfoxide (DMSO). The influence of solvent effect on the obtained acidity constants has been discussed. The acidity constants (expressed as pK a values) were compared with those previously determined in another polar protophobic aprotic solvent - acetone (AC), and obtained for the unsubstituted pyridine (Py). A comparison of the acid dissociation constants determined in all media studied has proved that the strength of the cationic acids increases on going from acetonitrile through propylene carbonate, acetone, and methanol to dimethyl sulfoxide. Furthermore, the values of acidity constants in the non-aqueous media have shown that in all the solvents studied they change according to the substituent effects. It has been also found that substituted 4-nitropyridine derivatives studied exhibit no tendency towards cationic homoconjugation in acetonitrile, propylene carbonate, and methanol and dimethyl sulfoxide. Moreover, it has been demonstrated that the acid dissociation constants determined by potentiometric titration method in all the solutions investigated correlate well with the calculated energy parameters of the protonation reactions in the gaseous phase

  14. Basicity comparison for di-substituted 4-nitropyridine derivatives in polar non-aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Gurzynski, Lukasz [Department of General and Inorganic Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland); Puszko, Aniela [Department of Organic Chemistry, School of Economics, Wroclaw (Poland); Chmurzynski, Lech [Department of General and Inorganic Chemistry, University of Gdansk, Sobieskiego 18, 80-952 Gdansk (Poland)], E-mail:


    Acid dissociation, as well as cationic homoconjugation equilibria have been studied potentiometrically in systems involving four di-substituted 4-nitropyridines and conjugate cationic acids in the polar non-aqueous solvents - aprotic protophobic acetonitrile (AN) and propylene carbonate (PC), the amphiprotic methanol (MeOH), and in the aprotic protophilic dimethyl sulfoxide (DMSO). The influence of solvent effect on the obtained acidity constants has been discussed. The acidity constants (expressed as pK{sub a} values) were compared with those previously determined in another polar protophobic aprotic solvent - acetone (AC), and obtained for the unsubstituted pyridine (Py). A comparison of the acid dissociation constants determined in all media studied has proved that the strength of the cationic acids increases on going from acetonitrile through propylene carbonate, acetone, and methanol to dimethyl sulfoxide. Furthermore, the values of acidity constants in the non-aqueous media have shown that in all the solvents studied they change according to the substituent effects. It has been also found that substituted 4-nitropyridine derivatives studied exhibit no tendency towards cationic homoconjugation in acetonitrile, propylene carbonate, and methanol and dimethyl sulfoxide. Moreover, it has been demonstrated that the acid dissociation constants determined by potentiometric titration method in all the solutions investigated correlate well with the calculated energy parameters of the protonation reactions in the gaseous phase.

  15. Residual Stress Formation Relating to Peak Temperature- and Austenite Grain Size-based Phase Transformation of S355 Steel (United States)

    Klaproth, Fabian; Vollertsen, Frank

    Nowadays thermal forming processes of steel are state of the art in industrial applications. Nevertheless, the influences of thermal induced phase-transformation on residual stresses and strength have not been fully observed. Times needed for transformation are affected by the initial austenite grain size, while the prevailing peak temperature influences austenite grain growth. Higher temperatures lead to larger austenite grains, leading to increased times for transformation. In order to get an embraced understanding of such effects numerical simulations of phase-transformations are mandatory. In this paper simulations of thermal forming processes, using S355 steel, are presented. Different continuous-cooling-transformation-diagrams (cct-diagrams) of specific austenite grain sizes for temperatures between transformation point AC3 and melting temperature are implemented in the model. It is shown that resulting magnitudes of residual stresses vary between 248 N/mm2 and 550 N/mm2. Finally an approach for the impact on relevant peak temperatures in the heat affected zone is outlined.

  16. Effect of residual stresses on individual phase mechanical properties of austeno-ferritic duplex stainless steel

    International Nuclear Information System (INIS)

    Dakhlaoui, R.; Baczmanski, A.; Braham, C.; Wronski, S.; Wierzbanowski, K.; Oliver, E.C.


    The mechanical properties of both phases in duplex stainless steel have been studied in situ using neutron diffraction during mechanical loading. Important differences in the evolution of lattice strains are observed between tests carried out in tension and compression. An elastoplastic self-consistent model is used to predict the evolution of internal stresses during loading and to identify critical resolved shear stresses and strain hardening parameters of the material. The differences between tensile and compressive behaviours of the phases are explained when the initial stresses are taken into account in model calculations. The yield stresses in each phase of the studied steel have been experimentally determined and successfully compared with the results of the elastoplastic self-consistent model

  17. Separation and effect of residual moisture in liquid phase adsorption of xylene on y zeolites

    Directory of Open Access Journals (Sweden)

    P. Lahot


    Full Text Available The separation of p-xylene and m-xylene from C8 aromatic hydrocarbon feed using Y zeolites is investigated. Effect of residual moisture on p-xylene adsorption on BaY was measured in order to optimize the activation temperature of the adsorbent. The results show that with an increase in temperature the moisture on the adsorbent decreases. An optimum loading of moisture is required for adsorption of xylene on the adsorbents. The Everett equation is used to determine the adsorption capacity and selectivity. It has been found that the adsorbents best suited for the separation of p-xylene, m-xylene, o-xylene and ethyl benzene from the mixture of C8 aromatics are NaY, NaY, BaY and KY, respectively. The XRD results show that the crystallinity of the adsorbent decreases upon exchanging the zeolites to K+ and Ba2+ ions.

  18. Spectral phase shift and residual angular dispersion of an accousto-optic programme dispersive filter

    International Nuclear Information System (INIS)

    Boerzsoenyi, A.; Meroe, M.


    Complete text of publication follows. There is an increasing demand for active and precise dispersion control of ultrashort laser pulses. In chirped pulse amplification (CPA) laser systems, the dispersion of the optical elements of the laser has to be compensated at least to the fourth order to obtain high temporal contrast compressed pulses. Nowadays the most convenient device for active and programmable control of spectral phase and amplitude of broadband laser pulses is the acousto-optic programmable dispersive filter (AOPDF), claimed to be able to adjust the spectral phase up to the fourth order. Although it has been widely used, surprisingly enough there has been only a single, low resolution measurement reported on the accuracy of the induced spectral phase shift of the device. In our paper we report on the first systematic experiment aiming at the precise characterization of an AOPDF device. In the experiment the spectral phase shift of the AOPDF device was measured by spectrally and spatially resolved interferometry, which is especially powerful tool to determine small dispersion values with high accuracy. Besides the spectral phase dispersion, we measured both the propagation direction angular dispersion (PDAD) and the phase front angular dispersion (PhFAD). Although the two quantities are equal for plane waves, there may be noticeable difference for Gaussian pulses. PDAD was determined simply by focusing the beam on the slit of an imaging spectrograph, while PhFAD was measured by the use of an inverted Mach-Zehnder interferometer and an imaging spectrograph. In the measurements, the spectral phase shift and both types of angular dispersion have been recorded upon the systematic change of all the accessible functions of the acousto-optic programmable dispersive filter. The measured values of group delay dispersion (GDD) and third order dispersion (TOD) have been found to agree with the preset values within the error of the measurement (1 fs 2 and 10 fs 3

  19. Non-Aqueous Biocatalysis in Homogeneous Solvent Systems

    Directory of Open Access Journals (Sweden)

    Sebastián Torres


    Full Text Available Enzymes are highly specific catalysts that typically function in aqueous solvents. However, many enzymes retain their catalytic activities at high concentrations in non- aqueous environments, including neat hydrophilic organic solvents. In fact, enzymes can be used to carry out reactions in organic solvents that are not possible in aqueous systems. Therefore, biocatalysis in homogenous non-aqueous solvents offers possibilities for producing useful chemicals and several synthetic reactions have already been developed using this type of system. The current review discusses factors that influence enzyme catalysis in non-aqueous solvents such us water content, solvent concentration, interaction of solvent with protein structure, stability and activity. Also, new strategies for non-conventional biocatalysis using extremophiles and ionic solvents are mentioned.

  20. Epoxy-silica hybrids by nonaqueous sol-gel process

    Czech Academy of Sciences Publication Activity Database

    Ponyrko, Sergii; Kobera, Libor; Brus, Jiří; Matějka, Libor


    Roč. 54, č. 23 (2013), s. 6271-6282 ISSN 0032-3861 R&D Projects: GA ČR GAP108/12/1459 Grant - others:AV ČR(CZ) M200500903 Institutional support: RVO:61389013 Keywords : epoxy-silica hybrid * nonaqueous sol-gel process * gelation Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.766, year: 2013

  1. Acetonitrile extraction and dual-layer solid phase extraction clean-up for pesticide residue analysis in propolis. (United States)

    Oellig, Claudia


    Propolis is a very complex mixture of substances that is produced by honey bees and is known to be a rather challenging matrix for residue analysis. Besides resins, flavonoids and phenols, high amount of wax is co-extracted resulting in immense matrix effects. Therefore a suitable clean-up is crucial and indispensable. In this study, a reliable solid phase extraction (SPE) clean-up was developed for pesticide residue analysis in propolis. The clean-up success was quickly and easily monitored by high-performance thin-layer chromatography with different detection possibilities. The final method consists of the extraction of propolis with acetonitrile according to the QuEChERS method followed by an effective extract purification on dual-layer SPE cartridges with spherical hydrophobic polystyrene-divinylbenzene resin/primary secondary amine as sorbent and a mixture of toluene/acetone (95:5, v/v) for elution. Besides fat-soluble components like waxes, flavonoids, and terpenoids, more polar compounds like organic acids, fatty acids, sugars and anthocyanins were also removed to large extent. Method performance was assessed by recovery experiments at spiking levels of 0.5 and 1mg/kg (n=5) for fourteen pesticides that are relevant for propolis. Mean recoveries determined by HPLC-MS against solvent standards were between 40 and 101%, while calculation against matrix-matched standards provided recoveries of 79-104%. Precision of recovery, assessed by relative standard deviations, were below 9%. Thus, the developed dual-layer SPE clean-up enables the reliable pesticide residue analysis in propolis and provides a suitable alternative to time-consuming clean-up procedures proposed in literature. Copyright © 2016 Elsevier B.V. All rights reserved.


    International Nuclear Information System (INIS)

    Caram, J.A.; Suárez, J.F. Martínez; Gennaro, A.M.; Mirífico, M.V.


    Graphical abstract: Display Omitted - Highlights: • The dye is electro-reduced in two separated monoelectronic charge transfers. • Solvent/supporting electrolyte/acid/base modifies the electrochemical parameters. • A dissociation equilibrium of the dye in non-aqueous solvent is proposed. • The electro-generated and stable dye-radical is also chemically produced in EDA or KOH/DMF. • A new species is reversibly formed in KOH/EtOH or ACN. - Abstract: The electrochemical behaviour of methylene blue in solution of non-aqueous solvents with different supporting electrolytes was studied by cyclic voltammetry. Dye electro-reduction presents two well-defined processes of monoelectronic charge transfer yielding a free radical in the first process and an anion in the second electron transfer. Free radical and anion are long living species in some of the studied media. Effects of supporting electrolyte and solvent on the peak potentials, the peak current functions and the reversibility of the charge transfer processes are reported. A dissociation equilibrium of the dye in solution of non-aqueous solvents and the acid or base added determine markedly the electrochemical responses. In the particular cases of KOH/DMF or EDA basic media the chemical formation of the stable methylene blue radical was detected and it was characterized by EPR spectroscopy. A general reaction scheme is proposed

  3. Assembly of DNA Architectures in a Non-Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Thomas J. Proctor


    Full Text Available In the present work, the procedures for the creation of self-assembled DNA nanostructures in aqueous and non-aqueous media are described. DNA-Surfactant complex formation renders the DNA soluble in organic solvents offering an exciting way to bridge the transition of DNA origami materials electronics applications. The DNA retains its structural features, and these unique geometries provide an interesting candidate for future electronics and nanofabrication applications with potential for new properties. The DNA architectures were first assembled under aqueous conditions, and then characterized in solution (using circular dichroism (CD spectroscopy and on the surface (using atomic force microscopy (AFM. Following aqueous assembly, the DNA nanostructures were transitioned to a non-aqueous environment, where butanol was chosen for optical compatibility and thermal properties. The retention of DNA hierarchical structure and thermal stability in non-aqueous conditions were confirmed via CD spectroscopy. The formation and characterization of these higher order DNA-surfactant complexes is described in this paper.

  4. Adaptive Control of Non-Minimum Phase Modal Systems Using Residual Mode Filters2. Parts 1 and 2 (United States)

    Balas, Mark J.; Frost, Susan


    Many dynamic systems containing a large number of modes can benefit from adaptive control techniques, which are well suited to applications that have unknown parameters and poorly known operating conditions. In this paper, we focus on a direct adaptive control approach that has been extended to handle adaptive rejection of persistent disturbances. We extend this adaptive control theory to accommodate problematic modal subsystems of a plant that inhibit the adaptive controller by causing the open-loop plant to be non-minimum phase. We will modify the adaptive controller with a Residual Mode Filter (RMF) to compensate for problematic modal subsystems, thereby allowing the system to satisfy the requirements for the adaptive controller to have guaranteed convergence and bounded gains. This paper will be divided into two parts. Here in Part I we will review the basic adaptive control approach and introduce the primary ideas. In Part II, we will present the RMF methodology and complete the proofs of all our results. Also, we will apply the above theoretical results to a simple flexible structure example to illustrate the behavior with and without the residual mode filter.

  5. Solid-Phase Extraction and Large-Volume Sample Stacking-Capillary Electrophoresis for Determination of Tetracycline Residues in Milk

    Directory of Open Access Journals (Sweden)

    Gabriela Islas


    Full Text Available Solid-phase extraction in combination with large-volume sample stacking-capillary electrophoresis (SPE-LVSS-CE was applied to measure chlortetracycline, doxycycline, oxytetracycline, and tetracycline in milk samples. Under optimal conditions, the proposed method had a linear range of 29 to 200 µg·L−1, with limits of detection ranging from 18.6 to 23.8 µg·L−1 with inter- and intraday repeatabilities < 10% (as a relative standard deviation in all cases. The enrichment factors obtained were from 50.33 to 70.85 for all the TCs compared with a conventional capillary zone electrophoresis (CZE. This method is adequate to analyze tetracyclines below the most restrictive established maximum residue limits. The proposed method was employed in the analysis of 15 milk samples from different brands. Two of the tested samples were positive for the presence of oxytetracycline with concentrations of 95 and 126 µg·L−1. SPE-LVSS-CE is a robust, easy, and efficient strategy for online preconcentration of tetracycline residues in complex matrices.

  6. Production of Bioethanol from Agricultural Wastes Using Residual Thermal Energy of a Cogeneration Plant in the Distillation Phase

    Directory of Open Access Journals (Sweden)

    Raffaela Cutzu


    Full Text Available Alcoholic fermentations were performed, adapting the technology to exploit the residual thermal energy (hot water at 83–85 °C of a cogeneration plant and to valorize agricultural wastes. Substrates were apple, kiwifruit, and peaches wastes; and corn threshing residue (CTR. Saccharomyces bayanus was chosen as starter yeast. The fruits, fresh or blanched, were mashed; CTR was gelatinized and liquefied by adding Liquozyme® SC DS (Novozymes, Dittingen, Switzerland; saccharification simultaneous to fermentation was carried out using the enzyme Spirizyme® Ultra (Novozymes, Dittingen, Switzerland. Lab-scale static fermentations were carried out at 28 °C and 35 °C, using raw fruits, blanched fruits and CTR, monitoring the ethanol production. The highest ethanol production was reached with CTR (10.22% (v/v and among fruits with apple (8.71% (v/v. Distillations at low temperatures and under vacuum, to exploit warm water from a cogeneration plant, were tested. Vacuum simple batch distillation by rotary evaporation at lab scale at 80 °C (heating bath and 200 mbar or 400 mbar allowed to recover 93.35% (v/v and 89.59% (v/v of ethanol, respectively. These results support a fermentation process coupled to a cogeneration plant, fed with apple wastes and with CTR when apple wastes are not available, where hot water from cogeneration plant is used in blanching and distillation phases. The scale up in a pilot plant was also carried out.

  7. A residual-based a posteriori error estimator for single-phase Darcy flow in fractured porous media

    KAUST Repository

    Chen, Huangxin


    In this paper we develop an a posteriori error estimator for a mixed finite element method for single-phase Darcy flow in a two-dimensional fractured porous media. The discrete fracture model is applied to model the fractures by one-dimensional fractures in a two-dimensional domain. We consider Raviart–Thomas mixed finite element method for the approximation of the coupled Darcy flows in the fractures and the surrounding porous media. We derive a robust residual-based a posteriori error estimator for the problem with non-intersecting fractures. The reliability and efficiency of the a posteriori error estimator are established for the error measured in an energy norm. Numerical results verifying the robustness of the proposed a posteriori error estimator are given. Moreover, our numerical results indicate that the a posteriori error estimator also works well for the problem with intersecting fractures.

  8. Measuring the phase difference in network and residual voltages under the GTsN-195M pump self-starting

    International Nuclear Information System (INIS)

    Druba, V.V.; Druba, T.A.; Reznik, V.R.


    Determination of time dependence of phase difference of residual voltage on motor windings of the main circulation pumps (MCP) and voltage of power supply section under MCP self-starting under conditions of short-time breaks in electric power supply is one of the main problems to which reliability and safety of NPP operation is related. A method to measure this dependence in real conditions in case of MCP free run-out and run-out in generating mode is suggested. The method considered is used for tests of the Kalinin NPP-2 MCP-195M self-starting. Analysis of run-out curves in the case of a break in MCP power supply for 1.8 s shows that the most favourable conditions for MCP self-starting are 0.63±0.03 s after de-energizing. 2 refs.; 3 figs.; 1 tab

  9. The effect of residual chlorides on resultant properties of solid and liquid phases after carbonization process

    Energy Technology Data Exchange (ETDEWEB)

    Plevova Eva; Sugarkova Vera; Kaloc Miroslav [Institute of Geonics ASCR, Ostrava (Czech Republic). Laboratory of Petrology


    The low-concentration condition was employed to model the carbonisation mode for local (Czech Republic) coals with higher concentrations of some metals. After completing the carbonisation, mass balance calculations were performed. Results show that the presence of zinc dichloride, copper dichloride and sodium chloride caused the most pronounced impediment to the formation of tar in contrast to lead dichloride and aluminium chloride that increased tar. The results demonstrated that adding of chloride agents effect both the course of the coking process and the properties of solid and liquid products of coking. Evaluation of the solid phase showed that chloride addition caused a decrease of the caking and swelling value, which corresponds with measurements of plasticity values that are of significant influence on mechanical properties closely related to coking plant processes. Evaluation of the liquid phase pointed towards an increase of aromatic hydrocarbons and their derivatives (especially phenanthrene, fluoranthene, acenaphthylene, pyrene) but a decrease of naphthalene and methylnaphthalene. Chloride addition increased aromaticity and caused a difference in substitution rate at aromatic nucleus. Mesophase estimation indicated extensive mosaic, domain and laminated anisotropic texture occurrence after chloride addition, mainly NaCl and CuCl{sub 2} addition. A more detailed evaluation including detailed screening, TGA, IR and RTG analysis will be subject of further investigation. 4 refs., 2 figs., 5 tabs.

  10. A method for calculating the acid-base equilibria in aqueous and nonaqueous electrolyte solutions (United States)

    Tanganov, B. B.; Alekseeva, I. A.


    Concentrations of particles in acid-base equilibria in aqueous and nonaqueous solutions of electrolytes are calculated on the basis of logarithmic charts, activity coefficients, and equilibrium constants.

  11. The chemistry of nonaqueous solvents v.4 solution phenomena and aprotic solvents

    CERN Document Server

    Lagowski, J J


    The Chemistry of Nonaqueous Solvents, Volume IV: Solution Phenomena and Aprotic Solvents focuses on the chemistry of nonaqueous solvents, with emphasis on solution phenomena and aprotic solvents such as tetramethylurea, inorganic acid chlorides, cyclic carbonates, and sulfolane. This book is organized into seven chapters and begins with an overview of the theory of electrical conductivity and elementary experimental considerations, along with some of the interesting research on nonaqueous solvents. It then turns to a discussion on hydrogen bonding phenomena in nonaqueous systems as probed

  12. Cross-linked PAN-based thin-film composite membranes for non-aqueous nanofiltration

    KAUST Repository

    Pérez-Manríquez, Liliana


    A new approach on the development of cross-linked PAN based thin film composite (TFC) membranes for non-aqueous application is presented in this work. Polypropylene backed neat PAN membranes fabricated by phase inversion process were cross-linked with hydrazine to get excellent solvent stability toward dimethylformamide (DMF). By interfacial polymerization a selective polyamide active layer was coated over the cross-linked PAN using N,N′-diamino piperazine (DAP) and trimesoyl chloride (TMC) as monomers. Permeation and molecular weight cut off (MWCO) experiments using various dyes were done to evaluate the performance of the membranes. Membranes developed by such method show excellent solvent stability toward DMF with a permeance of 1.7 L/m2 h bar and a molecular weight cut-off of less than 600 Da.

  13. Residue processing

    Energy Technology Data Exchange (ETDEWEB)

    Gieg, W.; Rank, V.


    In the first stage of coal hydrogenation, the liquid phase, light and heavy oils were produced; the latter containing the nonliquefied parts of the coal, the coal ash, and the catalyst substances. It was the problem of residue processing to extract from these so-called let-down oils that which could be used as pasting oils for the coal. The object was to obtain a maximum oil extraction and a complete removal of the solids, because of the latter were returned to the process they would needlessly burden the reaction space. Separation of solids in residue processing could be accomplished by filtration, centrifugation, extraction, distillation, or low-temperature carbonization (L.T.C.). Filtration or centrifugation was most suitable since a maximum oil yield could be expected from it, since only a small portion of the let-down oil contained in the filtration or centrifugation residue had to be thermally treated. The most satisfactory centrifuge at this time was the Laval, which delivered liquid centrifuge residue and centrifuge oil continuously. By comparison, the semi-continuous centrifuges delivered plastic residues which were difficult to handle. Various apparatus such as the spiral screw kiln and the ball kiln were used for low-temperature carbonization of centrifuge residues. Both were based on the idea of carbonization in thin layers. Efforts were also being made to produce electrode carbon and briquette binder as by-products of the liquid coal phase.

  14. Impact of GPS antenna phase center and code residual variation maps on orbit and baseline determination of GRACE (United States)

    Mao, X.; Visser, P. N. A. M.; van den IJssel, J.


    Precision Orbit Determination (POD) is a prerequisite for the success of many Low Earth Orbiting (LEO) satellite missions. With high-quality, dual-frequency Global Positioning System (GPS) receivers, typically precisions of the order of a few cm are possible for single-satellite POD, and of a few mm for relative POD of formation flying spacecraft with baselines up to hundreds of km. To achieve the best precision, the use of Phase Center Variation (PCV) maps is indispensable. For LEO GPS receivers, often a-priori PCV maps are obtained by a pre-launch ground campaign, which is not able to represent the real space-borne environment of satellites. Therefore, in-flight calibration of the GPS antenna is more widely conducted. This paper shows that a further improvement is possible by including the so-called Code Residual Variation (CRV) maps in absolute/undifferenced and relative/Double-differenced (DD) POD schemes. Orbit solutions are produced for the GRACE satellite formation for a four months test period (August-November, 2014), demonstrating enhanced orbit precision after first using the in-flight PCV maps and a further improvement after including the CRV maps. The application of antenna maps leads to a better consistency with independent Satellite Laser Ranging (SLR) and K-band Ranging (KBR) low-low Satellite-to-Satellite Tracking (ll-SST) observations. The inclusion of the CRV maps results also in a much better consistency between reduced-dynamic and kinematic orbit solutions for especially the cross-track direction. The improvements are largest for GRACE-B, where a cross-talk between the GPS main antenna and the occultation antenna yields higher systematic observation residuals. For high-precision relative POD which necessitates DD carrier-phase ambiguity fixing, in principle frequency-dependent PCV maps would be required. To this aim, use is made of an Extended Kalman Filter (EKF) that is capable of optimizing relative spacecraft dynamics and iteratively fixing

  15. Enhanced Retention of Chelating Reagents in Octadecylsilyl Silica Phase by Interaction with Residual Silanol Groups in Solid Phase Extraction of Divalent Metal Ions. (United States)

    Ohmuro, Satoshi; Fujii, Kan; Yasui, Takashi; Takada, Kazutake; Yuchi, Akio; Kokusen, Hisao


    Solid-phase extraction (SPE) of divalent metal ions with a lipophilic and potentially divalent hexadentate chelating reagent (H2L), with which octadecylsilyl silica (ODS), was impregnated with was studied to gain more insight into and develop the potential of this methodology. This is the first time to demonstrate that this reagent as well as other common nitrogen-containing reagents were retained both by adsorption due to hydrogen bonding between nitrogen atoms of the reagent and residual silanol groups in the ODS phase and by simple distribution into the hydrophobic space. An appreciably large amount of this reagent could be retained by the adsorption mechanism even with a relatively thin loading solution. The divalent metal ions of Mn(2+), Co(2+) and Zn(2+) were extracted as 1:1 neutral complexes ([ML]), while Ni(2+) and Cu(2+) as ion-pairs of 1:1 cationic complex ([MHL](+)) with anion in SPE with H2L. The extractability and selectivity were substantially the same as that in liquid-liquid extraction.

  16. Rapid microwave pyrolysis of coal: methodology and examination of the residual and volatile phases

    Energy Technology Data Exchange (ETDEWEB)

    Monsef-Mirzai, P.; Ravindran, M.; McWhinnie, W.R.; Burchill, P. (Aston University, Birmingham (United Kingdom). Dept. of Chemical Engineering and Applied Chemistry)


    Substances such as CuO, Fe[sub 3]O[sub 4] and even metallurgical coke (termed 'receptors') heat rapidly in a microwave oven at 2.45 GHz. The receptor, when mixed with Creswell coal and subjected to microwave radiation, induces rapid pyrolysis of the coal. Condensable tar yields of 20 wt% are obtained with coke, 27 wt% with Fe[sub 3]O[sub 4] and as high as 49 wt% in some experiments with CuO. Despite the high final temperature (1200-1300[degree]C after 3 min), analyses suggest that the volatiles are released in the lower part of the temperature regime but that some secondary cracking does occur. The tars are similar in composition, although with coke the proportion of aromatic hydrogen is greater than with CuO and Fe[sub 3]O[sub 4]. X-ray photoelectron spectroscopy shows that both pyridinic and pyrrolic nitrogen are present in the tars and chars, and that the dominant form of tar sulfur is thiophenic. There is evidence that mineral sulfur is immobilized when CuO in particular is the receptor. The chars formed show a degree of graphitization and are themselves excellent microwave receptors. In the presence of oxide receptors, char-oxide redox reactions occur, with loss of char, reduction of oxide and enhanced yields of CO and CO[sub 2]. Of the lighter hydrocarbons identified in the gas phase, methane predominates. The data obtained are compared with those for other pyrolysis methods. 22 refs., 1 fig., 9 tabs.

  17. A multi-residue method for characterization of endocrine disruptors in gaseous and particulate phases of ambient air (United States)

    Alliot, Fabrice; Moreau-Guigon, Elodie; Bourges, Catherine; Desportes, Annie; Teil, Marie-Jeanne; Blanchard, Martine; Chevreuil, Marc


    A number of semi-volatile compounds occur in indoor air most of them being considered as potent endocrine disruptors and thus, exerting a possible impact upon health. To assess their concentration levels in indoor air, we developed and validated a method for sampling and multi-residue analysis of 58 compounds including phthalates, polycyclic aromatic hydrocarbons (PAHs), polybromodiphenylethers (PBDEs), polychlorobiphenyls (PCBs), parabens, bisphenol A (BPA) and tetrabromobisphenol A (TBBPA) in gaseous and particulate phases of air. We validated each step of procedures from extraction until analysis. Matrice spiking were performed at extraction, fractionation and purification stages. The more volatile compounds were analyzed with a gas chromatography system coupled with a mass spectrometer (GC/MS) or with a tandem mass spectrometer (GC/MS/MS). The less volatile compounds were analyzed with a liquid chromatography system coupled with a tandem mass spectrometer (LC/MS/MS). Labeled internal standard method was used ensuring high quantification accuracy. The instrumental detection limits were under 1 pg for all compounds and therefore, a limit of quantification averaging 1 pg m-3 for the gaseous and the particulate phases and a volume of 150 m3, except for phthalates, phenol compounds and BDE-209. Satisfactory recoveries were found except for phenol compounds. That method was successfully applied to several indoor air samples (office, apartment and day nursery) and most of the targeted compounds were quantified, mainly occurring in the gaseous phase. The most abundant were phthalates (up to 918 ng m-3 in total air), followed by PCBs > parabens > BPA > PAHs > PBDEs.

  18. Development of technology and equipment for manufacturing fluorides rare-earths via non-aqueous method

    International Nuclear Information System (INIS)

    Chatalov, V.V.; Kozlov, O.I.; Machirev, V.P.; Zvonarev, E.N.


    Full text: The works on technology and equipment for rare earths (RE) fluorides are very scarce. Presently RE-fluorides are manufactured by various methods. Conventionally they can be divided into two main groups. The first group comprises methods based on precipitation of fluorides from soluble salts of corresponding metals by fluohydric acid (aqueous methods) with following thermal decomposition of aquatic fluorides obtained until anhydric state is reached. The second group (called dry, gaseous or non-aqueous) comprises methods based on direct fluorizating (by fluorine hydride, fluor or other fluorating agents) have several important advantages compared to the aqueous methods: the fluorides obtained are anhydrous; the operations of fluoride precipitation, washing, decantation, filtration are excluded as well as their drying and calcination. The process of calcination is, as a rule, accompanied by pyrohydrolysis. The products manufactured by precipitation are inferior to those obtained by the non-aqueous technique. The world production practice uses both groups of methods. Nevertheless, the method of gaseous hydrofluorination is preferable. In all non-aqueous processes the initial materials are oxides RE which interact with gaseous fluorine hydride. The initial materials - oxides are obtained by thermal decomposition of carbonates, hydroxides, oxalates and so on. One of the best type of apparatus for thermal decomposition processes is a horizontal ring shaped vibrating apparatus with direct heating. The RE - fluorides is synthesized by way of RE-oxide interacting with hydrogen fluoride at 200-550 deg C in single continuous operation: (RE) 2 O 3 + 6 HF → 2 (RE)F 3 + 3 H 2 0 The apparatus consists of a nickel horizontal two tube screw. Reaction time is varied from 2 to 6 hours; the productivity of reactor is defined by feed screw rotation and initial material bulk density. Hydrogen fluoride was passing the reactor opposite to the solid phase. The degree

  19. Valuation of solid phase extraction disks in the determination of pesticide residues in surface and groundwater in Panama

    International Nuclear Information System (INIS)

    Jimenez, V.; Ramos de Jimenez, J.; Rojas, B.


    In Panama large quantities of pesticides are used in agriculture and livestock farming and there is increasing concern about their impact on public health and the environment. Chiriqui is the Province that registers the largest number of producers whose activities have impact on the environment, especially on surface and groundwater. Systematic monitoring programmes are non-existent due, in part, to the high cost of laboratory determination of environmental residues of pesticides. Within the framework of the FAO/IAEA/SIDA Coordinated Research Programme, efforts were focused on evaluating and optimising the use of solid phase extraction C 18 membrane disks in the analysis of surface and groundwater samples to determine pesticide residues. Factors studied were the effect of pre-washing and conditioning of the disks, flow rates, concentration level and matrix effects of field samples. Four pesticides, carbofuran, chlorothalonil, ametryn and chlorpyrifos were selected for these tests because preliminary analysis showed their presence in surface and groundwater. The technique significantly reduces the amount of organic solvents used as compared with the liquid-liquid extraction method. Quantifiable detection limits (Q L ) for the method were found to be 0.003 μg/L carbofuran, 0.016 μg/L chlorothalonil, 0.007 μg/L ametryn and 0.003 μg/L chlorpyrifos, when using standard spiked solutions. Recovery (%) was high when standard mixtures were used for the test runs but low when real surface water samples were tested, especially for chlorothalonil which was not recovered at all. (author)

  20. Neutron Diffraction Residual Strain Tensor Measurements Within The Phase IA Weld Mock-up Plate P-5

    Energy Technology Data Exchange (ETDEWEB)

    Hubbard, Camden R [ORNL


    Oak Ridge National Laboratory (ORNL) has worked with NRC and EPRI to apply neutron and X-ray diffraction methods to characterize the residual stresses in a number of dissimilar metal weld mockups and samples. The design of the Phase IA specimens aimed to enable stress measurements by several methods and computational modeling of the weld residual stresses. The partial groove in the 304L stainless steel plate was filled with weld beads of Alloy 82. A summary of the weld conditions for each plate is provided in Table 1. The plates were constrained along the long edges during and after welding by bolts with spring-loaded washers attached to the 1-inch thick Al backing plate. The purpose was to avoid stress relief due to bending of the welded stainless steel plate. The neutron diffraction method was one of the methods selected by EPRI for non-destructive through thickness strain and stress measurement. Four different plates (P-3 to P-6) were studied by neutron diffraction strain mapping, representing four different welding conditions. Through thickness neutron diffraction strain mappings at NRSF2 for the four plates and associated strain-free d-zero specimens involved measurement along seven lines across the weld and at six to seven depths. The mountings of each plate for neutron diffraction measurements were such that the diffraction vector was parallel to each of the three primary orthogonal directions of the plate: two in-plane directions, longitudinal and transverse, and the direction normal to the plate (shown in left figure within Table 1). From the three orthogonal strains for each location, the residual stresses along the three plate directions were calculated. The principal axes of the strain and stress tensors, however, need not necessarily align with the plate coordinate system. To explore this, plate P-5 was selected for examination of the possibility that the principal axes of strain are not along the sample coordinate system axes. If adequate data could

  1. Lecture Notes and Guidance for Course 21220 (Non-aqueous Inorganic Chemistry)

    DEFF Research Database (Denmark)


    The lecture notes contain the theoretical as well as the practical background material necessary for mastering the special laboratory techniques used in non-aqueous inorganic chemistry (cfr. Course Descriptions, DTU).......The lecture notes contain the theoretical as well as the practical background material necessary for mastering the special laboratory techniques used in non-aqueous inorganic chemistry (cfr. Course Descriptions, DTU)....

  2. Ion Movement in Polypyrrole/Dodecylbenzenesulphonate Films in aqueous and non-aqueous electrolytes

    DEFF Research Database (Denmark)

    Vidanapathirana, K.; Careem, M.A.; Skaarup, Steen


    . Investigations were carried out using aqueous and non-aqueous electrolytes to study the effect of solvent on the ion movement during redox processes. When PPy films are cycled in aqueous electrolytes transport of both anion and cation occurs during oxidation and reduction. However, when cycled in the nonaqueous...... electrolyte propylene carbonate (PC) only anion movement takes place....

  3. Residual Sorption and leaching of the herbicide diuron following de-oiled two-phase olive mill waste addition to soil

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Pineiro, A.; Albarran, A.; Cabrera, D.; Rato, J. M.; Munoz, A.; Flores, S.


    The residual sorption, desorption, degradation, and leaching of the herbicide diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) a herbicide widely used in olive groves, was studied following the addition to soils of de oiled two-phase olive mill waste (DTPOMW). Field experiments were conducted on an olive grove soil amended over seven years with DTPOMW. (Author)

  4. Residual Sorption and leaching of the herbicide diuron following de-oiled two-phase olive mill waste addition to soil

    International Nuclear Information System (INIS)

    Lopez-Pineiro, A.; Albarran, A.; Cabrera, D.; Rato, J. M.; Munoz, A.; Flores, S.


    The residual sorption, desorption, degradation, and leaching of the herbicide diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea) a herbicide widely used in olive groves, was studied following the addition to soils of de oiled two-phase olive mill waste (DTPOMW). Field experiments were conducted on an olive grove soil amended over seven years with DTPOMW. (Author)

  5. Non-aqueous electrolytes for lithium ion batteries (United States)

    Chen, Zonghai; Amine, Khalil


    The present invention is generally related to electrolytes containing anion receptor additives to enhance the power capability of lithium-ion batteries. The anion receptor of the present invention is a Lewis acid that can help to dissolve LiF in the passivation films of lithium-ion batteries. Accordingly, one aspect the invention provides electrolytes comprising a lithium salt; a polar aprotic solvent; and an anion receptor additive; and wherein the electrolyte solution is substantially non-aqueous. Further there are provided electrochemical devices employing the electrolyte and methods of making the electrolyte.

  6. Non-aqueous removal of sodium from reactor components

    International Nuclear Information System (INIS)

    Welch, F.H.; Steele, O.P.


    Reactor components from sodium-cooled systems. whether radioactive or not, must have the sodium removed before they can be safely handled for 1) disposal, 2) examination and test, or 3) decontamination, repair, and requalification. In the latter two cases, the sodium must be removed in a manner which will not harm the component. and prevent future use. Two methods for sodium removal using non-aqueous techniques have been studied extensively in the U.S.A. in the past few years: the Alcohol Process, which uses a fully denatured ethanol to react away the sodium; and the Evaporative Process, which uses heat and vacuum to evaporate the sodium from the component

  7. Table 2.2. Cell voltages with nonaqueous electrolyte systems (United States)

    Holze, R.

    This document is part of Volume 9 `Electrochemistry', Subvolume A, of Landolt-Börnstein - Group IV `Physical Chemistry'. The document lists the normal voltages of cells in nonaqueous electrolyte systems. The cells are composed of the following materials: silver (Ag), barium (Ba), calcium (Ca), cadmium (Cd), cerium (Ce), copper (Cu), hydrogen (H), mercury (Hg), potassium (K), lanthanum (La), lithium (Li), magnesium (Mg), natrium (Na), lead (Pb), platinum (Pt), rubidium (Rb), thallium (Tl), zinc (Zn). The compositions of the cells are given along with, where available, the temperatures of measurements of the voltages.

  8. Soy Sauce Residue Oil Extracted by a Novel Continuous Phase Transition Extraction under Low Temperature and Its Refining Process. (United States)

    Zhao, Lichao; Zhang, Yong; He, Liping; Dai, Weijie; Lai, Yingyi; Yao, Xueyi; Cao, Yong


    On the basis of previous single-factor experiments, extraction parameters of soy sauce residue (SSR) oil extracted using a self-developed continuous phase transition extraction method at low temperature was optimized using the response surface methodology. The established optimal conditions for maximum oil yield were n-butane solvent, 0.5 MPa extraction pressure, 45 °C temperature, 62 min extraction time, and 45 mesh raw material granularity. Under these conditions, the actual yield was 28.43% ± 0.17%, which is relatively close to the predicted yield. Meanwhile, isoflavone was extracted from defatted SSR using the same method, but the parameters and solvent used were altered. The new solvent was 95% (v/v) ethanol, and extraction was performed under 1.0 MPa at 60 °C for 90 min. The extracted isoflavones, with 0.18% ± 0.012% yield, mainly comprised daidzein and genistein, two kinds of aglycones. The novel continuous phase transition extraction under low temperature could provide favorable conditions for the extraction of nonpolar or strongly polar substances. The oil physicochemical properties and fatty acids compositions were analyzed. Results showed that the main drawback of the crude oil was the excess of acid value (AV, 63.9 ± 0.1 mg KOH/g) and peroxide value (POV, 9.05 ± 0.3 mmol/kg), compared with that of normal soybean oil. However, through molecular distillation, AV and POV dropped to 1.78 ± 0.12 mg KOH/g and 5.9 ± 0.08 mmol/kg, respectively. This refined oil may be used as feedstuff oil.

  9. Review of alternative residual contamination guides for the 324 Building B-Cell Cleanout Project. Phase 1

    International Nuclear Information System (INIS)

    Vargo, G.J.; Durham, J.S.; Brackenbush, L.W.


    This report provides a proposed residual contamination guide (RCG) for the 324 Building B-Cell Cleanout Project, Phase 1, at the Hanford Site. The RCG is expressed as a fraction of the amount of highly dispersible radioactive material that would result in offsite doses equal to the Pacific Northwest Laboratory radiological risk guidelines following the worst credible accident scenario for release of the holdup material. The proposed RCG is 10 -1 to 10 -2 of the PNL radiological risk guidelines. As part of the development of the RCG, a number of factors were considered. These include the need to provide an appropriate level of flexibility for other activities within the 324 Building that could contribute to the facility's overall radiological risk, uncertainties inherent in safety analyses, and the possible contribution of other 300 Area facilities to overall radiological risk. Because of these factors and the nature of the cleanout project, the RCG is expressed as a range rather than a point value. This report also provides guidance on determining conformance to the RCG, including inspection and measurement techniques, quality assurance requirements, and consideration of uncertainty

  10. Matrix solid phase dispersion-Soxhlet simultaneous extraction clean-up for determination of organochlorine pesticide residues in tobacco. (United States)

    Cai, Jibao; Gao, Yun; Zhu, Xiaolan; Su, Qingde


    A novel method combining matrix solid phase dispersion (MSPD) with Soxhlet simultaneous extraction clean-up (SSEC) was developed. Being a single-step extraction and clean-up procedure, it could be used instead of multistep solvent extraction and Florisol column clean-up. It not only reduces sample contamination during the procedure, but it also decreases the amount of organic solvent needed. The retention times of standards were used to qualitatively assess the method, and the external standard method was used to quantitatively assess it. Residues of organochlorine pesticides (OCP) in tobaccos were determined by gas chromatography-electron capture detection (GC-ECD), and their identities were confirmed by the standard addition method (SAM). The performance of the method was evaluated and validated: the detection limit was 0.01-0.02 microg g(-1), relative standard deviations were 5-26%, and recoveries were 72-99% at fortification levels of 0.10, 1.00 and 10.0 microg g(-1). The analytical characteristics of MSPD-SSEC compared very favorably with the results from the classical multistep solvent extraction and Florisol column clean-up method.

  11. The Role of Air-Electrode Structure on the Incorporation of Immiscible PFCs in Nonaqueous Li-O2Battery. (United States)

    Balaish, Moran; Ein-Eli, Yair


    Perfluorocarbons (PFCs) are considered advantageous additives to nonaqueous Li-O 2 battery due to their superior oxygen solubility and diffusivity compared to common battery electrolytes. Up to now, the main focus was concentrated on PFCs-electrolyte investigation; however, no special attention was granted to the role of carbon structure in the PFCs-Li-O 2 system. In our current research, immiscible PFCs, rather than miscible fluorinated ethers, were added to activated carbon class air electrode due to their higher susceptibility toward O 2 •- attack and to their ability to shift the reaction from two-phase to an artificial three-phase reaction zone. The results showed superior battery performance upon PFCs addition at lower current density (0.05 mA cm -2 ) but unexpectedly failed to do so at higher current density (0.1 and 0.2 mA cm -2 ), where oxygen transport limitation is best illustrated. The last was a direct result of liquid-liquid displacement phenomenon occurring when the two immiscible liquids were introduced into the porous carbon medium. The investigation and role of carbon structure on the mechanism upon PFCs addition to Li-O 2 system are suggested based on electrochemical characterization, wettability behavior studies, and the physical adsorption technique. Finally, we suggest an optimum air-electrode structure enabling the incorporation of immiscible PFCs in a nonaqueous Li-O 2 battery.

  12. Nonaqueous Dispersion Formed by an Emulsion Solvent Evaporation Method Using Block-Random Copolymer Surfactant Synthesized by RAFT Polymerization. (United States)

    Ezaki, Naofumi; Watanabe, Yoshifumi; Mori, Hideharu


    As surfactants for preparation of nonaqueous microcapsule dispersions by the emulsion solvent evaporation method, three copolymers composed of stearyl methacrylate (SMA) and glycidyl methacrylate (GMA) with different monomer sequences (i.e., random, block, and block-random) were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. Despite having the same comonomer composition, the copolymers exhibited different functionality as surfactants for creating emulsions with respective dispersed and continuous phases consisting of methanol and isoparaffin solvent. The optimal monomer sequence for the surfactant was determined based on the droplet sizes and the stabilities of the emulsions created using these copolymers. The block-random copolymer led to an emulsion with better stability than obtained using the random copolymer and a smaller droplet size than achieved with the block copolymer. Modification of the epoxy group of the GMA unit by diethanolamine (DEA) further decreased the droplet size, leading to higher stability of the emulsion. The DEA-modified block-random copolymer gave rise to nonaqueous microcapsule dispersions after evaporation of methanol from the emulsions containing colored dyes in their dispersed phases. These dispersions exhibited high stability, and the particle sizes were small enough for application to the inkjet printing process.

  13. The influence of water percolation on flow of light non aqueous phase liquids in soil

    NARCIS (Netherlands)

    Marsman, A.


    Keywords ,: multi-phase flow, entrapment, numerical modeling, similarity solution, horizontal migration, percolation theory, relative permeability.

    In this thesis the physical behavior of Light Non-Aqueous Phase Liquids (LNAPL) at the capillary

  14. Assessment of ex-vitro anaerobic digestion kinetics of crop residues through first order exponential models: effect of lag phase period and curve factor

    International Nuclear Information System (INIS)

    Sahito, A.R.; Brohi, K.M.


    Kinetic studies of AD (Anaerobic Digestion) process are useful to predict the performance of digesters and design appropriate digesters and also helpful in understanding inhibitory mechanisms of biodegradation. The aim of this study was to assess the anaerobic kinetics of crop residues digestion with buffalo dung. Seven crop residues namely, bagasse, banana plant waste, canola straw, cotton stalks, rice straw, sugarcane trash and wheat straw were selected from the field and were analyzed on MC (Moisture Contents), TS (Total Solids) and VS (Volatile Solids) with standard methods. In present study, three first order exponential models namely exponential model, exponential lag phase model and exponential curve factor model were used to assess the kinetics of the AD process of crop residues and the effect of lag phase and curve factor was analyzed based on statistical hypothesis testing and on information theory. Assessment of kinetics of the AD of crop residues and buffalo dung follows the first order kinetics. Out of the three models, the simple exponential model was the poorest model, while the first order exponential curve factor model is the best fit model. In addition to statistical hypothesis testing, the exponential curve factor model has least value of AIC (Akaike's Information Criterion) and can generate methane production data more accurately. Furthermore, there is an inverse linear relationship between the lag phase period and the curve factor. (author)

  15. Improved physical stability and injectability of non-aqueous in situ PLGA microparticle forming emulsions. (United States)

    Voigt, M; Koerber, M; Bodmeier, R


    The goal of this study was to obtain physically stable non-aqueous in situ forming microparticle (ISM) emulsions capable of forming biodegradable microparticles upon injection. ISM emulsions consist of a biocompatible organic PLGA solution dispersed in a continuous oil phase prepared in a two-syringe/connector system prior to administration. A variety of parenteral approved excipients were tested for a stability-enhancing effect and possible stabilization mechanisms evaluated. Glycerol monostearate (GMS) showed superior stabilizing potential prolonging the emulsion stability from a few minutes to more than 12h. Flow behavior analysis, differential scanning calorimetry, polarized light- and Cryo-electron microscopy revealed, that the stabilization was caused by an immediate, more than 5-fold viscosity increase in the continuous phase after emulsification and by a stabilized interface through a liquid crystalline GMS layer around the polymer solution droplets. Despite the viscosity increase the injectability of the stabilized ISM emulsion was improved by about 30% compared to the corresponding highly viscous PLGA solution (in situ implant) due to a pronounced shear thinning of the GMS containing oil phase. The injectability improvement allows a faster administration or enables the use of thinner needles and hence reduced patient discomfort. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Non-Aqueous Titration Method for Determining Suppressor Concentration in the MCU Next Generation Solvent (NGS)

    International Nuclear Information System (INIS)

    Taylor-Pashow, Kathryn M. L.; Jones, Daniel H.


    A non-aqueous titration method has been used for quantifying the suppressor concentration in the MCU solvent hold tank (SHT) monthly samples since the Next Generation Solvent (NGS) was implemented in 2013. The titration method measures the concentration of the NGS suppressor (TiDG) as well as the residual tri-n-octylamine (TOA) that is a carryover from the previous solvent. As the TOA concentration has decreased over time, it has become difficult to resolve the TiDG equivalence point as the TOA equivalence point has moved closer. In recent samples, the TiDG equivalence point could not be resolved, and therefore, the TiDG concentration was determined by subtracting the TOA concentration as measured by semi-volatile organic analysis (SVOA) from the total base concentration as measured by titration. In order to improve the titration method so that the TiDG concentration can be measured directly, without the need for the SVOA data, a new method has been developed that involves spiking of the sample with additional TOA to further separate the two equivalence points in the titration. This method has been demonstrated on four recent SHT samples and comparison to results obtained using the SVOA TOA subtraction method shows good agreement. Therefore, it is recommended that the titration procedure be revised to include the TOA spike addition, and this to become the primary method for quantifying the TiDG.

  17. Non-Aqueous Titration Method for Determining Suppressor Concentration in the MCU Next Generation Solvent (NGS)

    Energy Technology Data Exchange (ETDEWEB)

    Taylor-Pashow, Kathryn M. L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jones, Daniel H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    A non-aqueous titration method has been used for quantifying the suppressor concentration in the MCU solvent hold tank (SHT) monthly samples since the Next Generation Solvent (NGS) was implemented in 2013. The titration method measures the concentration of the NGS suppressor (TiDG) as well as the residual tri-n-octylamine (TOA) that is a carryover from the previous solvent. As the TOA concentration has decreased over time, it has become difficult to resolve the TiDG equivalence point as the TOA equivalence point has moved closer. In recent samples, the TiDG equivalence point could not be resolved, and therefore, the TiDG concentration was determined by subtracting the TOA concentration as measured by semi-volatile organic analysis (SVOA) from the total base concentration as measured by titration. In order to improve the titration method so that the TiDG concentration can be measured directly, without the need for the SVOA data, a new method has been developed that involves spiking of the sample with additional TOA to further separate the two equivalence points in the titration. This method has been demonstrated on four recent SHT samples and comparison to results obtained using the SVOA TOA subtraction method shows good agreement. Therefore, it is recommended that the titration procedure be revised to include the TOA spike addition, and this to become the primary method for quantifying the TiDG.

  18. Morphology and thermophysical properties of non-aqueous titania nanofluids (United States)

    Murshed, S. M. S.; Santos, F. J. V.; Nieto de Castro, C. A.; Patil, V. S.; Patil, K. R.


    This work deals with the experimental investigation on thermophysical properties of TiO2-nanofluids and characterization of morphology and structure of TiO2 nanoparticles. Non-aqueous liquids like silicone oil and ethylene glycol are used as base fluids to prepare the nanofluids. Thermophysical properties including viscosity and thermal conductivity of these nanofluids are measured at different concentrations and temperatures. Results showed that silicone oil-based TiO2 nanofluid is Newtonian and the viscosity of this nanofluid increases with the loading of nanoparticles but it decreases nonlinearly with increasing temperature. Existing viscosity models are found unable to predict the viscosity of nanofluids. Although the effective thermal conductivities of both the silicone oil and ethylene glycol-based nanofluids increased with the TiO2 concentration, their enhanced thermal conductivity was found to decrease with increasing temperature.

  19. Photochemical recovery of europium from non-aqueous solutions. (United States)

    Van den Bogaert, Bart; Gheeraert, Lore; Leblebici, Mumin Enis; Binnemans, Koen; Van Gerven, Tom


    The photochemical recovery of europium from non-aqueous media, more specifically alcohols, is studied. The recovery was performed by photochemical reduction of europium(iii) to europium(ii) and subsequent removal as the insoluble EuCl 2 . Two charge transfer bands are present in the UV-C region, one originating from the alcohol (around 230 nm) and the other from the chloride anion (at 271 nm), which are responsible for the photochemical reduction when the solution is illuminated by a medium-pressure mercury lamp. When using different alcohol solvents, a trend is observed with regards to the removal rate and efficiency, following methanol (MeOH) lamp phosphors (Y 2 O 3 :Eu 3+ ), which consist entirely of europium and yttrium with a Eu/Y molar ratio of 1/20-1/30.

  20. Non-aqueous Electrode Processing and Construction of Lithium-ion Coin Cells. (United States)

    Stein, Malcolm; Chen, Chien-Fan; Robles, Daniel J; Rhodes, Christopher; Mukherjee, Partha P


    Research into new and improved materials to be utilized in lithium-ion batteries (LIB) necessitates an experimental counterpart to any computational analysis. Testing of lithium-ion batteries in an academic setting has taken on several forms, but at the most basic level lies the coin cell construction. In traditional LIB electrode preparation, a multi-phase slurry composed of active material, binder, and conductive additive is cast out onto a substrate. An electrode disc can then be punched from the dried sheet and used in the construction of a coin cell for electrochemical evaluation. Utilization of the potential of the active material in a battery is critically dependent on the microstructure of the electrode, as an appropriate distribution of the primary components are crucial to ensuring optimal electrical conductivity, porosity, and tortuosity, such that electrochemical and transport interaction is optimized. Processing steps ranging from the combination of dry powder, wet mixing, and drying can all critically affect multi-phase interactions that influence the microstructure formation. Electrochemical probing necessitates the construction of electrodes and coin cells with the utmost care and precision. This paper aims at providing a step-by-step guide of non-aqueous electrode processing and coin cell construction for lithium-ion batteries within an academic setting and with emphasis on deciphering the influence of drying and calendaring.

  1. Increased component safety through improved methods for residual stress analysis. Subprojects. Consideration of the elastic-plastic material properties (Phase 2). Final report

    International Nuclear Information System (INIS)

    Mirbach, David von


    Residual stresses in mechanical components can result in both detrimental but also beneficial effects on the strength and lifetime of the components. The most detailed knowledge of the residual stress state is of advantage or a pre-requisite for the assessment of the component performance. Two commonly used methods for determination of residual stresses are the hole drilling method and the ring core method which can be regarded to the mechanical methods. In the context of reactor safety research of the German Federal Ministry of Economic and Energy (BMWi) two fundamental and interacting weak points of the hole drilling method as well as of the ring core method, respectively, in order to determine residual stresses are going to be investigated. As a consequence reliability of the methods will be improved in this joint research project. On the one hand there are effects of geometrical boundary conditions of the components and on the other hand there is the influence of plasticity due to notch effects both affecting the released strain field after removing material and after all the calculated residual stresses. The first issue mentioned above is under the responsibility of the Institute of Materials Engineering (Kassel University) and the last one is investigated by materials testing institute university Stuttgart. As a consequence of a successful project the knowledge base will be considerably improved resulting in benefits for various engineering fields. Especially the quantitative consideration of real residual stress states for optimized component designs will be possible and after all the consequences of residual stresses on safety of components which are used in nuclear facilities can be evaluated. In this second experimental research chapter (phase 2) the findings of the first numerical and theoretical research chapter (phase 1) where proofed. The developed differential calculation method with the method of adaptive calibration functions were compared with the

  2. Residual deposits (residual soil)

    International Nuclear Information System (INIS)

    Khasanov, A.Kh.


    Residual soil deposits is accumulation of new formate ore minerals on the earth surface, arise as a result of chemical decomposition of rocks. As is well known, at the hyper genes zone under the influence of different factors (water, carbonic acid, organic acids, oxygen, microorganism activity) passes chemical weathering of rocks. Residual soil deposits forming depends from complex of geologic and climatic factors and also from composition and physical and chemical properties of initial rocks

  3. Mastering analytical challenges for the characterization of pentacyclic triterpene mono- and diesters of Calendula officinalis flowers by non-aqueous C30 HPLC and hyphenation with APCI-QTOF-MS. (United States)

    Nicolaus, Christoph; Sievers-Engler, Adrian; Murillo, Renato; D'Ambrosio, Michele; Lämmerhofer, Michael; Merfort, Irmgard


    Pentacyclic triterpene mono- and diesters have been isolated from Calendula officinalis flowers. GC-MS, APCI-Exactive Orbitrap HR-MS and NMR allowed to identify the triterpene skeleton in various samples (different triterpene mixtures from Calendula n-hexane extract). NMR provided evidence that triterpene diesters are present in the samples as well. However, the corresponding quasi-molecular ions could not be detected by APCI-Exactive Orbitrap HR-MS. Instability of triterpene diesters and loss of a fatty acid residue, respectively, in the ion-source made their MS detection challenging. Thus, a set of new APCI-QTOF-MS methods (using the TripleTOF 5600+ mass spectrometer) were developed which made it eventually possible to solve this problem and confirm the diester structures by MS via quasi-molecular ion [M+H](+) detection. Direct infusion APCI-QTOF MS experiments in MS/MS high sensitivity scan mode with low collision energy and multi-channel averaging acquisition (MCA) allowed the detection of quasi-molecular ions of triterpene diesters for the first time and unequivocally confirmed the presence of faradiol 3,16-dimyristate and -dipalmitate, as well as the corresponding mixed diesters faradiol 3-myristate,16-palmitate and faradiol 3-palmitate,16-myristate. Preferential loss of the fatty acid in 16-position made it possible to distinguish the mixed diesters by MS/MS spectra. Their chromatographic separations turned out to be challenging due to their bulkiness and extended molecular dimensions. However, separation could be achieved by an uncommon non-aqueous RPLC mode with an in-house synthesized C30 phase. Finally, two (U)HPLC-APCI-QTOF-MS methods with C18- and C30-based non-aqueous RPLC provided suitable, sensitive assays to monitor the presence of monoesters and diesters of various triterpenes (faradiol, maniladiol, arnidiol, arnitriol A and lupane-3β,16β,20-triol esters) in the n-hexane extract of C. officinalis with high mass resolution and good mass accuracy

  4. Effect of the Basic Residue on the Energetics, Dynamics and Mechanisms of Gas- Phase Fragmentation of Protonated Peptides

    Energy Technology Data Exchange (ETDEWEB)

    Laskin, Julia; Yang, Zhibo; Song, Tao; Lam, Corey; Chu, Ivan K.


    The effect of the basic residue on the energetics, dynamics and mechanisms of backbone fragmentation of protonated peptides was investigated. Time- and collision energy-resolved surface-induced dissociation (SID) of singly protonated peptides with the N-terminal arginine residue and their analogs, in which arginine is replaced with less basic lysine and histidine residues was examined using in a specially configured Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS). SID experiments demonstrated very different kinetics of formation of several primary product ions of peptides with and without arginine residue. The energetics and dynamics of these pathways were determined from the RRKM modeling of the experimental data. Comparison between the kinetics and energetics of fragmentation of arginine-containing peptides and the corresponding methyl ester derivatives provides important information on the effect of dissociation pathways involving salt bridge (SB) intermediates on the observed fragmentation behavior. It is found that because pathways involving SB intermediates are characterized by low threshold energies, they efficiently compete with classical oxazolone pathways of arginine-containing peptides on a long timescale of the FT-ICR instrument. In contrast, fragmentation of histidine- and lysine-containing peptides is largely determined by classical oxazolone pathways. Because SB pathways are characterized by negative activation entropies, fragmentation of arginine-containing peptides is kinetically hindered and observed at higher collision energies as compared to their lysine- and histidine-containing analogs.

  5. Influence of residual phases on the properties of YBa{sub 2}Cu{sub 3}O{sub 7{minus}x}

    Energy Technology Data Exchange (ETDEWEB)

    Sargankova, I.; Diko, P.; Timko, M.; Slanco, P.; Matas, S.; Mihalik, M. [Slovak Academy of Sciences, Kosice (Slovakia). Inst. of Experimental Physics; Mihalik, J. [Slovak Academy of Sciences, Kosice (Slovakia). Inst. of Materials Research; Bunda, V. [Uzhorod State Univ. (Ukraine). Dept. of Physics of Semiconductors


    The partial melting in YBaCuO incompletely synthesized powders occurring at temperatures below the peritectic decomposition of the 123 (YBa{sub 2}Cu{sub 3}O{sub 7{minus}x}) compounds is related to the presence of residual phases. The results showed that the final ceramic has got a high porosity, which is independent on the temperature of sintering, the double grain size distribution and two transition temperatures up to the sintering temperature 940 C as a consequence of a higher content of the residual carbonate. The sintering at higher-temperature improved superconducting properties of ceramics. This progress is connected with cracking of large grain ceramic and with the decomposition of carbonate BaCO{sub 3}.

  6. Gender differences in quality of life and functional disability for depression outpatients with or without residual symptoms after acute phase treatment in China. (United States)

    Zhao, Na; Wang, Xiaohong; Wu, Wenyuan; Hu, Yongdong; Niu, Yajuan; Wang, Xueyi; Gao, Chengge; Zhang, Ning; Fang, Yiru; Huang, Jizhong; Liu, Tiebang; Jia, Fujun; Zhu, Xuequan; Hu, Jian; Wang, Gang


    Depression is associated with substantial personal suffering and reduced quality of life and functioning. The aim of this study was to investigate gender differences on quality of life and functional impairment of outpatients with depression after acute phase treatment. 1503 depression outpatients were recruited from eleven hospitals in China. Subjects were evaluated with sociodemographic characteristics, history and self-report instruments, related to severity of symptoms, function and quality of life. All data were analyzed to determine the gender differences. Men had a younger age at onset and the first onset age, higher education compared to women in total patients and with or without residual symptoms group. Using regression analysis, it was found that gender was significantly statistically related to severity scores of SDS and had no correlation with Q-LES-Q-SF total scores. In the residual symptoms group, greater functional impairment was noted by men in the area of work and social life. Significant gender differences of mood, work and sexual life in quality of life were observed. This is a cross-sectional study of depressed outpatients and duration of acute phase treatment may not an adequate time to measure changes. Depression appears to affect men more seriously than women after acute phase treatment. Men had a younger age at onset and the first onset age, higher education, more functional impairment and lower satisfaction of quality of life in mood, work and sexual life. Gender differences affect acute treatment, remission and recovery. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Autofocus Correction of Azimuth Phase Error and Residual Range Cell Migration in Spotlight SAR Polar Format Imagery


    Mao, Xinhua; Zhu, Daiyin; Zhu, Zhaoda


    Synthetic aperture radar (SAR) images are often blurred by phase perturbations induced by uncompensated sensor motion and /or unknown propagation effects caused by turbulent media. To get refocused images, autofocus proves to be useful post-processing technique applied to estimate and compensate the unknown phase errors. However, a severe drawback of the conventional autofocus algorithms is that they are only capable of removing one-dimensional azimuth phase errors (APE). As the resolution be...

  8. The oxidation mechanism of the antioxidant quercetin in nonaqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Sokolova, Romana, E-mail: [J. Heyrovsky Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejskova 3, 18223 Prague (Czech Republic); Degano, Ilaria [Department of Chemistry and Industrial Chemistry, University of Pisa, Via Risorgimento 35, 56100 Pisa (Italy); Ramesova, Sarka; Bulickova, Jana; Hromadova, Magdalena; Gal, Miroslav; Fiedler, Jan [J. Heyrovsky Institute of Physical Chemistry, v.v.i., Academy of Sciences of the Czech Republic, Dolejskova 3, 18223 Prague (Czech Republic); Valasek, Michal [Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, 16610 Prague 6 (Czech Republic)


    The knowledge of the degradation pathways of natural dyes used in medieval textiles is necessary for the restoration of their original color. Quercetin, one of such colorants, reportedly yields the wide spectrum of oxidation products in different types of media. This study deals with electrochemical oxidation mechanism of quercetin in nonaqueous solution, which has not been yet attempted. The final oxidation product at the first oxidation wave was identified by HPLC-DAD and GC-MS techniques as 2-(3',4'-dihydroxybenzoyl)-2,4,6-trihydroxybenzofuran-3(2H)-one. The apparent two-electron process at the potential of the first oxidation wave yields current-voltage shapes with one-electron characteristics. The in situ spectroelectrochemistry measurements proved the oxidation mechanism leading through a short-lived anion radical. Two possibilities of the oxidation mechanism are discussed: two one-electron transfers, which do not have identical but similar redox potentials, or the presence of a disproportionation chemical reaction following the first one electron transfer. The quinone formed in either case is stable only on the time scale of a fast spectroelectrochemistry and undergoes fast hydroxylation reaction, where 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxybenzofuran-3-one is formed. This compound is oxidized at the potential of the second oxidation wave of quercetin.

  9. Nonaqueous Hybrid Lithium-Ion and Sodium-Ion Capacitors. (United States)

    Wang, Huanwen; Zhu, Changrong; Chao, Dongliang; Yan, Qingyu; Fan, Hong Jin


    Hybrid metal-ion capacitors (MICs) (M stands for Li or Na) are designed to deliver high energy density, rapid energy delivery, and long lifespan. The devices are composed of a battery anode and a supercapacitor cathode, and thus become a tradeoff between batteries and supercapacitors. In the past two decades, tremendous efforts have been put into the search for suitable electrode materials to overcome the kinetic imbalance between the battery-type anode and the capacitor-type cathode. Recently, some transition-metal compounds have been found to show pseudocapacitive characteristics in a nonaqueous electrolyte, which makes them interesting high-rate candidates for hybrid MIC anodes. Here, the material design strategies in Li-ion and Na-ion capacitors are summarized, with a focus on pseudocapacitive oxide anodes (Nb 2 O 5 , MoO 3 , etc.), which provide a new opportunity to obtain a higher power density of the hybrid devices. The application of Mxene as an anode material of MICs is also discussed. A perspective to the future research of MICs toward practical applications is proposed to close. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. On the calculation of disjoining pressure isotherms for nonaqueous films. (United States)

    Correa, Rafael; Saramago, Benilde


    A review of the methods of London and Hamaker and of Lifshitz for calculating disjoining pressure isotherms of nonaqueous liquid films is presented. The disjoining pressure isotherms for films of n-octane and of three triglycerides (tributyrin, tricaprylin, and triolein) on glass were calculated using both methods. The disjoining pressure isotherms for films on silanized glass were calculated using only the London-Hamaker approach. The refractive indices and static dielectric constants, necessary for the calculations, were measured. The silanized glass was considered to be the original glass covered by a layer with the same characteristic frequency as the underlying glass and a smaller limiting value of the dielectric constant epsilon(0). The limiting dielectric constant epsilon(0) and the thickness of the surface layer were taken as adjustable parameters. The disjoining pressure isotherms indicate that all films are stable on glass. In contrast, the stability of the films formed on silanized glass was found to depend mainly on the value of epsilon(0) and, less strongly, on the thickness of the surface layer. The stability of the films decreased with the decrease of epsilon(0) and, for each value of epsilon(0), was maximal for the thinnest surface layer.

  11. Synthesis of iron oxide nanoparticles under oxidizing environment and their stabilization in aqueous and non-aqueous media

    International Nuclear Information System (INIS)

    Maity, D.; Agrawal, D.C.


    Synthesis of magnetite (Fe 3 O 4 ) nanoparticles under oxidizing environment by precipitation from aqueous media is not straightforward because Fe 2+ gets oxidized to Fe 3+ and thus the ratio of Fe 3+ :Fe 2+ =2:1 is not maintained during the precipitation. A molar ratio of Fe 3+ :Fe 2+ smaller than 2:1 has been used by many to compensate for the oxidation of Fe 2+ during the preparation. In this work, we have prepared iron oxide nanoparticles in air environment by the precipitation technique using initial molar ratios Fe 3+ :Fe 2+ ≤2:1. The phases of the resulting powders have been determined by several techniques. It is found that the particles consist mainly of maghemite with little or no magnetite phase. The particles have been suspended in non-aqueous and aqueous media by coating the particles with a single layer and a bilayer of oleic acid, respectively. The particle sizes, morphology and the magnetic properties of the particles and the ferrofulids prepared from these particles are reported. The average particle sizes obtained from the TEM micrographs are 14, 10 and 9 nm for the water, kerosene and dodecane-based ferrofluids, respectively, indicating a better dispersion in the non-aqueous media. The specific saturation magnetization (σ s ) value of the oleic-acid-coated particles (∼53 emu/g) is found to be lower than that for the uncoated particles (∼63 emu/g). Magnetization σ s of the dodecane-based ferrofluid is found to be 10.1 emu/g for a volume fraction of particles φ=0.019. Zero coercivity and zero remanance on the magnetization curves indicate that the particles are superparamagnetic (SPM) in nature

  12. A rapid, solid phase extraction (SPE technique for the extraction and gas chromatographic determination lindane pesticide residue in tissue and milk

    Directory of Open Access Journals (Sweden)



    Full Text Available Organochlorine pesticide contamination in feed can cause residue in animal product (tissue and milk, so its become a problem in food safety. Solid phase extraction (SPE has been carried out for determination organochlorine pesticide residues in food animal production. The technique was rapid, not costly and produce limited amount of hazardous-waste. Samples were homogenized with acetonitrile trough cartridge C18, eluted in fluorocyl column with 2% ether-petroleum or acetonitrile fortissue and milk samples respectively. The recoveries of tissue sample by addition lindane standard solution: 0.50 and 1.00 μg are 85.10 and 103.10% respectively, while that of milk with the addition of 0.50, 1.00 and 1.50 μg are 83.80, 88.69 and 91.24% respectively. Three replicates were carried out for every sample. According of validation criteria of FAO/IAEA the recovery for analysis of pesticide residues was 70-110%. Therefore, the method is applicable.

  13. Residual elastic strain measurement in heat-treated and/or plastically deformed two-phase stainless steel by neutron diffraction

    International Nuclear Information System (INIS)

    Harjo, S.; Sato, Hideo; Tomota, Yo; Ono, Masayoshi


    The testing method of microscopic residual stress in commercial material using neutral diffraction is not established yet like that using x-ray diffraction. Then, in this research a microscopic residual stress of α/γ two phase Fe-Cr-Ni alloy convenient for an experiment was tried by using neutron diffraction, to investigate its testing method. And further, a test using x-ray diffraction was also conducted for their comparison. As a result, some problems in the residual stress measurement using neutron diffraction were summarized shown as follows. On precision of d 0 , since proper reference material was difficult for material M to provide, a preferable result could not be obtained in the stress measurement using PSD method. On curve fitting, by changing from a multi order function to a Voigt function by using the curve-fitting method, it was found that the peak could be fit better. Furthermore, on the problem of testing condition, because of weak intensity of the neutron source, it was necessary to use a monochromator capable of collecting incident beam like Bent crystal, and to improve sample setting, counter and slit. (G.K.)

  14. A phase II study of intraperitoneal radioimmunotherapy with iodine-131-labeled monoclonal antibody OC-125 in patients with residual ovarian carcinoma. (United States)

    Mahé, M A; Fumoleau, P; Fabbro, M; Guastalla, J P; Faurous, P; Chauvot, P; Chetanoud, L; Classe, J M; Rouanet, P; Chatal, J F


    Standard treatment of advanced ovarian cancer is a combination of surgery and chemotherapy. Additional therapies using the i.p. route are considered as a potential means of improving the locoregional control rate. This Phase II study evaluated the efficacy of i.p. radioimmunotherapy (RIT) in patients with minimal residual ovarian adenocarcinoma after primary treatment with surgery and chemotherapy. Between February 1995 and March 1996, six patients with residual macroscopic (<5 mm) or microscopic disease as demonstrated by laparotomy and multiple biopsies received i.p. RIT. All had initial stage III epithelial carcinoma and were treated with debulking surgery and one line (four patients) or two lines (two patients) of chemotherapy. RIT was performed with 60 mg of OC 125 F(ab')2 monoclonal antibody labeled with 4.44 GBq (120 mCi) of 131I injected 5-10 days after the surgical procedure. Systematic laparoscopy or laparotomy with multiple biopsies performed 3 months after RIT in five patients (clinical progression was seen in one patient) showed no change in three patients and progression in two patients. Toxicity was mainly hematological, with grade III neutropenia and thrombocytopenia in two patients. Human antimouse antibody production was demonstrated in all six patients. This study showed little therapeutic benefit from i.p. RIT in patients with residual ovarian carcinoma.

  15. Determination of some selected pesticide residues in apple juice by solid-phase microextraction coupled to gas chromatography – mass spectrometry

    Directory of Open Access Journals (Sweden)

    Andrea Hercegová


    Full Text Available The performance of solid phase microextraction (SPME for enrichment of pesticides from apple juice was investigated. Samples were diluted with water, extracted by solid-phase microextraction and analysed by gas chromatography using mass-spectrometry detector (MSD in selected ion monitoring mode (SIM. The method was tested for the following pesticides used mostly in fruit culturing at Slovakia: tebuthylazine, fenitrothion, chlorpyrifos, myclobutanil, cyprodinil, phosalone, pyrimethanil, tebuconazole, kresoxim-methyl, methidathion, penconazole. All pesticides were extracted with polydimethylsiloxane fibre 100 μm thickness. The linear concentration range of application was 0.05 μg dm−3–10 μg dm−3. The method described provides detectabilities complying with the maximum residue levels (MRLs set by regulatory organizations for pesticides in apple juice matrices. The solvent – free SPME procedure was found to be quicker and more cost effective then the solvent extraction methods commonly used.

  16. Development of Fe-B Based Bulk Metallic Glasses: Morphology of Residual Phases in Fe50Ni16Mo6B18Zr10 Glass

    Directory of Open Access Journals (Sweden)

    Tiburce A. Aboki


    Full Text Available Iron-boron based bulk metallic glasses (BMG development has been initiated using Fe40Ni38Mo4B18 as precursor. Addition of zirconium up to 10 atomic % along with the reduction of Ni proportion improves the glass forming ability (GFA, which is optimum when Ni is suppressed in the alloy. However melting instability occurred during the materials fabrication resulting in the formation of residual crystalline phases closely related to the amorphous phase. Microstructure study shows an evolution from amorphous structure to peculiar acicular structure, particularly for Fe50Ni16Mo6B18Zr10, suggesting the amorphous structure as interconnected atomic sheets like “atomic mille feuilles” whose growth affects the alloys’ GFA.

  17. Lateral gradients of phases, residual stress and hardness in a laser heated Ti0.52Al0.48N coating on hard metal. (United States)

    Bartosik, M; Daniel, R; Zhang, Z; Deluca, M; Ecker, W; Stefenelli, M; Klaus, M; Genzel, C; Mitterer, C; Keckes, J


    The influence of a local thermal treatment on the properties of Ti-Al-N coatings is not understood. In the present work, a Ti 0.52 Al 0.48 N coating on a WC-Co substrate was heated with a diode laser up to 900 °C for 30 s and radially symmetric lateral gradients of phases, residual stress and hardness were characterized ex - situ using position-resolved synchrotron X-ray diffraction, Raman spectroscopy, transmission electron microscopy and nanoindentation. The results reveal (i) a residual stress relaxation at the edge of the irradiated area and (ii) a compressive stress increase of few GPa in the irradiated area center due to the Ti-Al-N decomposition, in particular due to the formation of small wurtzite (w) AlN domains. The coating hardness increased from 35 to 47 GPa towards the center of the heated spot. In the underlying heated substrate, a residual stress change from about - 200 to 500 MPa down to a depth of 6 μm is observed. Complementary, in - situ high-temperature X-ray diffraction analysis of stresses in a homogeneously heated Ti 0.52 Al 0.48 N coating on a WC-Co substrate was performed in the range of 25-1003 °C. The in - situ experiment revealed the origin of the observed thermally-activated residual stress oscillation across the laser heated spot. Finally, it is demonstrated that the coupling of laser heating to produce lateral thermal gradients and position-resolved experimental techniques opens the possibility to perform fast screening of structure-property relationships in complex materials.

  18. Nonaqueous capillary electrophoresis of imatinib mesylate and related substances. (United States)

    Ye, Lei; Huang, Yifei; Li, Jian; Xiang, Guangya; Xu, Li


    In the present study, nonaqueous capillary electrophoretic separation of imatinib mesylate (IM) and related substances, N-(5-amino-2-methylphenyl)-4-(3-pyridyl)-2-pyrimidinamine (PYA), N-(4-methyl-3-(4-(pyridin-3-yl)pyrimidin-2-ylamino)phenyl)-4-((piperazin-1-yl)methyl) benzamide (NDI) and 4-chloromethyl-N-(4-methyl-3-((4-(pyridin-3-yl) pyrimidin-2-yl) amino) phenyl) benzamide (CPB) was developed. The influential factors affecting separation, including type and concentration of the electrolyte, applied voltage, and buffer modifier were investigated. Baseline separation of the studied analytes was obtained using a buffer of 50 mM Tris and 50 mM methanesulfonic acid in methanol at a apparent pH (pH*) of 1.65. To enhance the sensitivity, large-volume sample stacking was employed for online concentration. The strongest analytical signal with a suitable separation was achieved when the injection time was 100 s. The linearity ranges of PYA and NDI were 0.100-2.50 μg mL(-1), and that of CPB was 0.125-2.50 μg mL(-1), with good coefficients (r(2) > 0.9948). The relative standard deviations of intra- and interday were satisfactory. Under the optimized conditions, seven batches of the synthesized samples were analyzed and CPB was detected in two batches. Owing to its simplicity, effectiveness, and low price, the developed method is promising for quality control of IM. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Bacillus subtilis with endocellulase and exocellulase activities isolated in the thermophilic phase from composting with coffee residues. (United States)

    Siu-Rodas, Yadira; Calixto-Romo, María de Los Angeles; Guillén-Navarro, Karina; Sánchez, José E; Zamora-Briseño, Jesús Alejandro; Amaya-Delgado, Lorena


    The goal of this study was to isolate, select and characterize bacteria with cellulolytic activity from two different coffee residue composting piles, one of which had an internal temperature of 57°C and pH 5.5 and the other, a temperature of 61°C, and pH 9.3. Culture media were manipulated with carboxymethylcellulose and crystalline cellulose as sole carbon sources. The enzyme activity was assessed by hydrolysis halo formation, reducing sugar production and zymograms. Three out of twenty isolated strains showed higher enzymatic activity and were identified as Bacillus subtilis according to their morphological, physiological, biochemical characteristics and based on the sequence analysis of 16S rDNA regions. The enzymatic extracts of the three selected strains showed exocellulase and endocellulase maximum activity of 0.254 and 0.519 U/ml, respectively; the activity of these enzymes was maintained even in acid pH (4.8) and basic (9.3) and at temperatures of up to 60°C. The enzymatic activities observed in this study are within the highest reported for cellulose produced by bacteria of the genus Bacillus. Endocellulase activity was shown in the zymograms from 24h until 144h of incubation. Furthermore, the pH effect on the endocellulase activity is reported for the first time by zymograms. The findings in this study entail the possibility to use these enzymes in the procurement of fermentable substrates for the production of energy from the large amount of residues generated by the coffee agroindustry. Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Monitoring of N-methyl carbamate pesticide residues in water using hollow fibre supported liquid membrane and solid phase extraction (United States)

    Msagati, Titus A. M.; Mamba, Bhekie B.

    The aim of this work was to develop a method for the determination of N-methyl carbamates in water involving hollow fibre supported liquid membrane (HFSLM) and solid phase extraction (SPE) as sample preparation methods. Four N-methyl carbamate pesticides, aldicarb, carbaryl, carbofuran and methiocarb sulfoxide, were simultaneously extracted and analysed by a liquid chromatograph with a diode array detector (LC-UV/DAD) and a liquid chromatograph coupled to a ion trap quadrupole mass spectrometer (LC-ESI-MS). The high performance liquid chromatography (HPLC) separation of carabamate extracts was performed on a C18 column with water-acetonitrile as the mobile phase. The mass spectrometry analyses were carried out in the positive mode, operating under both the selected ion monitoring (SIM) and full scan modes. The solid phase recoveries of the extracts ranged between 8% and 98%, with aldicarb having the highest recoveries, followed by carbaryl, carbofuran and methiocarb had the lowest recovery. The HFSLM recovery ranged between 8% and 58% and the order of recovery was similar to the SPE trend. Factors controlling the efficiency of the HFSLM extraction such as sample pH, stripping phase pH, enrichment time, stirring speed as well as organic solvent used for entrapment of analytes, were optimised to achieve the highest enrichment factors.

  1. Additive enhanced non-aqueous electrodeposition of silver on Ba2YCu3O7

    International Nuclear Information System (INIS)

    Rosamilia, J.M.; Miller, B.


    A non-aqueous plating bath for silver deposition on the Ba 2 YCu 3 O 7 superconductor has been modified with thiourea to give enhanced coverage of the metal film at low thicknesses. For both porous and high density ceramic substrates, SEM and optical microscopy show nucleation of silver deposits is increased by the additive. The resulting silver-superconductor contact resistances are comparable to those achieved without additives. Adhesion of the deposits and ease of mechanical handling are improved with thiourea. The combination of highly reactive oxidized substrate, non-aqueous solvent, and strongly surface active agent form a novel extension for electrodeposition science

  2. Determination of pesticide residues and related compounds in water and industrial effluent by solid-phase extraction and gas chromatography coupled to triple quadrupole mass spectrometry. (United States)

    Martins, Manoel L; Donato, Filipe F; Prestes, Osmar D; Adaime, Martha B; Zanella, Renato


    Pollution of drinking water supplies from industrial waste is a result of several industrial processes and disposal practices, and the establishment of analytical methods for monitoring organic compounds related to environmental and health problems is very important. In this work, a method using solid-phase extraction (SPE) and gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-QqQ-MS/MS) was developed and validated for the simultaneous determination of pesticide residues and related compounds in drinking and surface water as well as in industrial effluent. Optimization of the method was achieved by using a central composite design approach on parameters such as the sample pH and SPE eluent composition. A single SPE consisting of the loading on a polymeric sorbent of 100 mL of sample adjusted to pH 3 and elution with methanol/methylene chloride (10:90, v/v) permitted the obtaining of acceptable recoveries in most cases. The concentration factor associated with sensitivity of the chromatographic analysis permitted the achievement of the method limit of detection values between 0.01 and 0.25 μg L(-1). Recovery assays presented mean recoveries between 70 and 120% for most of the compounds with very good precision, despite the different chemical nature of the compounds analyzed. The selectivity of the method, evaluated through the relative intensity of quantification and qualification ions obtained by GC-QqQ-MS/MS, was considered adequate. The developed method was finally applied to the determination of target analytes in real samples. River water and treated industrial effluent samples presented residues of some compounds, but no detectable residues were found in the drinking water samples evaluated.

  3. Preconcentration of Trace Neonicotinoid Insecticide Residues Using Vortex-Assisted Dispersive Micro Solid-Phase Extraction with Montmorillonite as an Efficient Sorbent

    Directory of Open Access Journals (Sweden)

    Khwankaew Moyakao


    Full Text Available In this work, we investigated montmorillonite for adsorption of neonicotinoid insecticides in vortex-assisted dispersive micro-solid phase extraction (VA-d-μ-SPE. High-performance liquid chromatography with photodiode array detection was used for quantification and determination of neonicotinoid insecticide residues, including thiamethoxam, clothianidin, imidacloprid, acetamiprid, and thiacloprid. In this method, the solid sorbent was dispersed into the aqueous sample solution and vortex agitation was performed to accelerate the extraction process. Finally, the solution was filtered from the solid sorbent with a membrane filter. The parameters affecting the extraction efficiency of the proposed method were optimized, such as amount of sorbent, sample volume, salt addition, type and volume of extraction solvent, and vortex time. The adsorbing results show that montmorillonite could be reused at least 4 times and be used as an effective adsorbent for rapid extraction/preconcentration of neonicotinoid insecticide residues. Under optimum conditions, linear dynamic ranges were achieved between 0.5 and 1000 ng mL−1 with a correlation of determination (R2 greater than 0.99. Limit of detection (LOD ranged from 0.005 to 0.065 ng mL−1, while limit of quantification (LOQ ranged from 0.008 to 0.263 ng mL−1. The enrichment factor (EF ranged from 8 to 176-fold. The results demonstrated that the proposed method not only provided a more simple and sensitive method, but also can be used as a powerful alternative method for the simultaneous determination of insecticide residues in natural surface water and fruit juice samples.

  4. Analysis of carbamate and phenylurea pesticide residues in fruit juices by solid-phase microextraction and liquid chromatography-mass spectrometry. (United States)

    Sagratini, Gianni; Mañes, Jordi; Giardiná, Dario; Damiani, Pietro; Picó, Yolanda


    A new analysis method to detect carbamates and phenylurea pesticide residues in fruit juices was developed using solid-phase microextraction (SPME) coupled with liquid chromatography-single quadrupole mass spectrometry (LC/MS) and liquid chromatography-quadrupole ion trap mass spectrometry (LC/QIT-MS). The pesticide residues present in watery matrices as fruit juices were extracted using three types of fibers: 50-microm Carbowax/templated resin (CW/TPR), 60-mum poly(dimethylsiloxane)/divinylbenzene (PDMS/DVB) and 85-microm polyacrylate. The different extraction conditions were evaluated choosing as the best parameters 90 min (time), 20 degrees C (temperature) and 1 ml (volume). After extraction, the desorption (in a static mode) was performed in the specific interface chamber SPME/HPLC, previously filled with 70% methanol and 30% water. The best recoveries, evaluated at two fortification levels (0.2 and 0.5 mg kg(-1)) in fruit juices, were obtained using PDMS/DVB and CW/TPR fibers, and ranged from 25 to 82% (monolinuron, diuron and diethofencarb), with relative standard deviations (RSDs) from 1 to 17%. All the limits of quantification (LOQs) were in the range of 0.005-0.05 microg ml(-1) and, in any case, equal to, or lower than, maximum residue limits (MRLs) established by Italian and Spanish legislations. The mass spectrometry analyses were carried out using an electrospray ionization (ESI) source operating in the positive mode both for single quadrupole and for QIT mass analysers, operating in selected ion monitoring (SIM) and in multiple reaction monitoring (MRM) modes, respectively. The proposed new method can be applied to the determination of selected pesticides in real samples of fruit juices.

  5. Fabric phase sorptive extraction of selected penicillin antibiotic residues from intact milk followed by high performance liquid chromatography with diode array detection. (United States)

    Samanidou, Victoria; Michaelidou, Katia; Kabir, Abuzar; Furton, Kenneth G


    Fabric phase sorptive extraction (FPSE), a novel sorbent-based microextraction method, was evaluated as a simple and rapid strategy for the extraction of four penicillin antibiotic residues (benzylpenicillin, cloxacillin, dicloxacillin and oxacillin) from cows' milk, without prior protein precipitation. Time-consuming solvent evaporation and reconstitution steps were eliminated successfully from the sample preparation workflow. FPSE utilizes a flexible fabric substrate, chemically coated with sol-gel derived, highly efficient, organic-inorganic hybrid sorbent as the extraction medium. Herein short-chain poly(ethylene glycol) provided optimum extraction sensitivity for the selected penicillins, which were analysed using an RP-HPLC method, validated according to the European Decision 657/2002/EC. The limit of quantitation was 10μg/kg for benzylpenicillin, 20μg/kg for cloxacillin, 25μg/kg dicloxacillin and 30μg/kg oxacillin. These are a similar order of magnitude with those reported in the literature and (with the exception of benzylpenicillin) are less than the maximum residue limits (MRL) set by European legislation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. [A Simultaneous Determination Method with Acetonitrile-n-Hexane Partitioning and Solid-Phase Extraction for Pesticide Residues in Livestock and Marine Products by GC-MS]. (United States)

    Yoshizaki, Mayuko; Kobayashi, Yukari; Shimizu, Masanori; Maruyama, Kouichi


    A simultaneous determination method was examined for 312 pesticides (including isomers) in muscle of livestock and marine products by GC-MS. The pesticide residues extracted from samples with acetone and n-hexane were purified by acetonitrile-n-hexane partitioning, and C18 and SAX/PSA solid-phase extraction without using GPC. Matrix components such as cholesterol were effectively removed. In recovery tests performed by this method using pork, beef, chicken and shrimp, 237-257 pesticides showed recoveries within the range of 70-120% in each sample. Validity was confirmed for 214 of the target pesticides by means of a validation test using pork. In comparison with the Japanese official method using GPC, the treatment time of samples and the quantity of solvent were reduced substantially.

  7. Thermometric titration of some monoprotic and diprotic acids in aqueous and non-aqueous media. (United States)

    Harries, R J


    Some mono- and diprotic acids have been titrated thermometrically with strong alkalis in aqueous and non-aqueous media. Thermograms with sharp arrest points were obtained, from which heats of neutralization were measured. Heats of neutralization in the media used were compared and an effect attributable to hydrogen bonding was found.

  8. Anthraquinone with Tailored Structure for Nonaqueous Metal-Organic Redox Flow Battery

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei; Xu, Wu; Cosimbescu, Lelia; Choi, Daiwon; Li, Liyu; Yang, Zhenguo


    A nonaqueous, hybrid metal-organic redox flow battery based on tailored anthraquinone structure is demonstrated to have an energy efficiency of {approx}82% and a specific discharge energy density similar to aqueous redox flow batteries, which is due to the significantly improved solubility of anthraquinone in supporting electrolytes.

  9. Impact of Liquid-Vapor to Liquid-Liquid-Vapor Phase Transitions on Asphaltene-Rich Nanoaggregate Behavior in Athabasca Vacuum Residue + Pentane Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Long, Bingwen; Chodakowski, Martin; Shaw, John M. [Alberta; (Beijing U)


    The bulk phase behavior of heavy oil + alkane mixtures and the behavior of the asphaltenes that they contain are topics of importance for the design and optimization of processes for petroleum production, transport, and refining and for performing routine saturates, aromatics, resins, and asphaltenes (SARA) analyses. In prior studies, partial phase diagrams and phase behavior models for Athabasca vacuum residue (AVR) comprising 32 wt % pentane asphaltenes + n-alkanes were reported. For mixtures with pentane, observed phase behaviors included single-phase liquid as well as liquid–liquid, liquid–liquid–vapor, and liquid–liquid–liquid–vapor regions. Dispersed solids were detected under some conditions as well but not quantified. In this work, small-angle X-ray scattering (SAXS) is used to study nanostructured materials in liquid phases present in AVR + n-pentane mixtures from 50 to 170 °C at mixture bubble pressure. The investigation focuses on the impact of the transition from a single AVR-rich liquid to co-existing pentane-rich and AVR-rich liquids on the nanostructure and the nanostructures most resistant to aggregation as the pentane composition axis is approached. Background scattering subtraction was performed using global mixture composition. The robustness of this assumption with respect to values obtained for coefficients appearing in a two level Beaucage unified equation fit is demonstrated. The nanostructured material is shown to arise at two length scales from 1 to 100 wt % AVR. Smaller nanostructures possess mean radii less than 50 Å, while the larger nanostructures possess mean radii greater than 250 Å. The addition of pentane to the AVR causes an increasingly large fraction of the large and small nanostructures to grow in size. Only nanostructures resistant to aggregation remain in the pentane-rich phase as the 0 wt % AVR axis is approached. Step changes in aggregation identified from changes in average radius of gyration, scattering

  10. Pile composting of two-phase centrifuged olive husk residues: technical solutions and quality of cured compost. (United States)

    Alfano, G; Belli, C; Lustrato, G; Ranalli, G


    The present work proposed an economically sustainable solution for composting olive humid husks (OHH) and leaves (OL) at a small/medium sized olive oil mill. We planned and set up a composting plant, the prototype taking the form of a simplified low-cost turning machine, and evaluated the use of an inoculum of one year-old composted humid husks (CHH) and sheep manure (SM) to facilitate the starting phase of the process. Trials were carried out using four piles under different experimental conditions (turnover, static, and type of inoculum). The best results were achieved with turnover and an inoculum that induced fast start-up and a correct evolution of the composting process. The final product was a hygienically clean, cured compost.

  11. Non-aqueous metathesis as a general approach to prepare nanodispersed materials: Case study of scheelites

    Energy Technology Data Exchange (ETDEWEB)

    Afanasiev, Pavel, E-mail:


    A general approach to the preparation of inorganic nanoparticles is proposed, using metathesis of precursor salts in non-aqueous liquids. Nanoparticles of scheelites AMO{sub 4} (A=Ba, Sr, Ca; M=Mo, W), were obtained with a quantitative yield. Precipitations in formamide, N-methylformamide, propylene carbonate, DMSO and polyols often provide narrow particle size distributions. Advantageous morphology was explained by strong ionic association in non-aqueous solvents, leading to slow nucleation and negligible Ostwald ripening. Mean particle size below 10 nm and high specific surface areas were obtained for several Ca(Sr)Mo(W)O{sub 4} materials, making them promising for applications as adsorbents or catalysts. Zeta-potential of scheelites in aqueous suspensions showed negative values in a wide range of pH. Systematic study of optical properties demonstrated variation of optical gap in the sequences W>Mo and Ba>Sr>Ca. The observed trends were reproduced by DFT calculations. No quantum confinement effect was observed for small particles, though the surface states induce low-energy features in the optical spectra. - Graphical abstract: Scheelites AMO{sub 4} (A=Ca, Sr, Ba; M=Mo, W) were prepared in various non-aqueous liquids with high specific surface areas and narrow size distributions. The optical gap of scheelites changes in the series Canon-aqueous liquids. • Narrow size distributions explained by ionic association in non-aqueous media. • Nanoparticles of less than 10 nm size and highest ever specific surface areas were obtained. • Optical gap of scheelites changes in the series Ca

  12. Solid phase extraction-capillary electrophoresis determination of sulphonamide residues in milk samples by use of C18-carbon nanotubes as hybrid sorbent materials. (United States)

    Polo-Luque, M L; Simonet, B M; Valcárcel, M


    The exceptional sorption capabilities of carbon nanotubes were used to preconcentrate trace sulphonamides from milk samples. To this end, single walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) dispersed in the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate were retained on a C18 stationary phase to obtain a hybrid material in a simple manner. In this approach ionic liquids are an excellent alternative to improve the dispersion of CNTs, without chemical modification or the use of solid substances or organic solvents. MWNTs provided better results than SWNTs. Carbon nanotubes retained in the C18 sorbent matrix were found to confer aromatic character, increasing its preconcentration capacity as a result. The conventional C18 stationary phase played a two-fold role: as a support to retain carbon nanotubes in the cartridge and as a medium to prevent their aggregation. The modified MWNT/C18 and SWNT/C18 materials were used to preconcentrate residual sulphonamides (SAs) in milk samples for their determination at concentrations as low as 0.03-0.069 mg L(-1) by capillary electrophoresis. Analyte recoveries from spiked samples ranged from 103.2 to 98.8% and precision, as RSD, from 8.2 to 5.4%.

  13. Multi-residue analysis of drugs of abuse in wastewater and surface water by solid-phase extraction and liquid chromatography-positive electrospray ionisation tandem mass spectrometry. (United States)

    Baker, David R; Kasprzyk-Hordern, Barbara


    A new-multi residue method was developed for the environmental monitoring of 65 stimulants, opiod and morphine derivatives, benzodiazepines, antidepressants, dissociative anaesthetics, drug precursors, human urine indicators and their metabolites in wastewater and surface water. The proposed analytical methodology offers rapid analysis for a large number of compounds, with low limits of quantification and utilises only one solid-phase extraction-ultra performance liquid chromatography-positive electrospray ionisation tandem mass spectrometry (SPE-LC-MS/MS) method, thus overcoming the drawbacks of previously published procedures. The method employed solid phase extraction with the usage of Oasis MCX sorbent and subsequent ultra performance liquid chromatography-positive electrospray ionisation tandem mass spectrometry. The usage of a 1.7 μm particle size column (1 mm×150 mm) resulted in very low flow rates (0.04 mLmin(-1)), and as a consequence gave good sensitivity, low mobile phase consumption and short retention times for all compounds (from 2.9 to 23.1 min). High SPE recoveries (>60%) were obtained for the majority of compounds. The mean correlation coefficients of the calibration curves were typically higher than 0.997 and showed good linearity in the range 0-1000 μgL(-1). The method limits of detection ranged from 0.1 ngL(-1) for compounds including cocaine, benzoylecgonine, norbenzoylecgonine and 2-oxo-3-hydroxy-LSD to 100 ngL(-1) for caffeine. Method quantification limits ranged from 0.5 to 154.2 ngL(-1). Intra- and inter-day repeatabilities were on average less than 10%. The method accuracy range was within -33.1 to 30.1%. The new multi-residue method was used to analyse drugs of abuse in wastewater and river water in the UK environment. Of the targeted 65 compounds, 46 analytes were detected at levels above the method quantification limit (MQL) in wastewater treatment plant (WWTP) influent, 43 in WWTP effluent and 36 compounds in river water. Copyright

  14. Mineral Phases and Release Behaviors of As in the Process of Sintering Residues Containing As at High Temperature

    Directory of Open Access Journals (Sweden)

    Xingrun Wang


    Full Text Available To investigate the effect of sintering temperature and sintering time on arsenic volatility and arsenic leaching in the sinter, we carried out experimental works and studied the structural changes of mineral phases and microstructure observation of the sinter at different sintering temperatures. Raw materials were shaped under the pressure of 10 MPa and sintered at 1000~1350°C for 45 min with air flow rate of 2000 mL/min. The results showed that different sintering temperatures and different sintering times had little impact on the volatilization of arsenic, and the arsenic fixed rate remained above 90%; however, both factors greatly influenced the leaching concentration of arsenic. Considering the product’s environmental safety, the best sintering temperature was 1200°C and the best sintering time was 45 min. When sintering temperature was lower than 1000°C, FeAsS was oxidized into calcium, aluminum, and iron arsenide, mainly Ca3(AsO42 and AlAsO4, and the arsenic leaching was high. When it increased to 1200°C, arsenic was surrounded by a glass matrix and became chemically bonded inside the matrix, which lead to significantly lower arsenic leaching.

  15. Nonaqueous synthesis of metal oxide nanoparticles: Short review and doped titanium dioxide as case study for the preparation of transition metal-doped oxide nanoparticles (United States)

    Djerdj, Igor; Arčon, Denis; Jagličić, Zvonko; Niederberger, Markus


    The liquid-phase synthesis of metal oxide nanoparticles in organic solvents under exclusion of water is nowadays a well-established alternative to aqueous sol-gel chemistry. In this article, we highlight some of the advantages of these routes based on selected examples. The first part reviews some recent developments in the synthesis of ternary metal oxide nanoparticles by surfactant-free nonaqueous sol-gel routes, followed by the discussion of the morphology-controlled synthesis of lanthanum hydroxide nanoparticles, and the presentation of structural peculiarities of manganese oxide nanoparticles with an ordered Mn vacancy superstructure. These examples show that nonaqueous systems, on the one hand, allow the preparation of compositionally complex oxides, and, on the other hand, make use of the organic components (initially present or formed in situ) in the reaction mixture to tailor the morphology. Furthermore, obviously even the crystal structure can differ from the corresponding bulk material like in the case of MnO nanoparticles. In the second part of the paper we present original results regarding the synthesis of dilute magnetic semiconductor TiO 2 nanoparticles doped with cobalt and iron. The structural characterization as well as the magnetic properties with special attention to the doping efficiency is discussed.

  16. On-line solid phase extraction-ultra high performance liquid chromatography-tandem mass spectrometry as a powerful technique for the determination of sulfonamide residues in soils. (United States)

    Tetzner, Natália Fernanda; Maniero, Milena Guedes; Rodrigues-Silva, Caio; Rath, Susanne


    Sulfonamides are antimicrobials used widely as veterinary drugs, and their residues have been detected in environmental matrices. An analytical method for determining sulfadiazine, sulfathiazole, sulfamethazine, sulfamethoxazole, sulfadimethoxine and sulfaquinoxaline residues in soils employing a solid phase extraction on-line technique coupled with ultra-high performance liquid chromatography and tandem mass spectrometry (SPE-UHPLC-MS/MS) was developed and validated in this study. SPE and chromatographic separation were performed using an Oasis HLB column and an Acquity UPLC BEH C18 analytical column, respectively, at 40°C. Samples were prepared by extracting sulfonamides from soil using a solid-liquid extraction method with water:acetonitrile, 1:1v/v (recovery of 70.2-99.9%). The following parameters were evaluated to optimize the on-line SPE process: sorbent type (Oasis and C8), sample volume (100-400μL), loading solvent (water and different proportions of water:methanol) and washing volume (0.19-0.66mL). The method produced linear results for all sulfonamides from 0.5 to 12.5ngg(-1) with a linearity greater than 0.99. The precision of the method was less than 15%, and the matrix effect was -27% to -87%. The accuracy was in the range of 77-112% for all sulfonamides. The limit of quantitation in the two soils (clay and sand) was 0.5ngg(-1). The SPE column allowed for the analysis of many (more than 2000) samples without decreasing the efficiency. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. [Monitoring of the residue of fosthiazate in water samples using solid-phase extraction coupled with gas chromatography/mass spectrometry]. (United States)

    Zhu, Jing; Zhou, Xin; Fu, Chunmei; Liu, Sankang; Li, Zhangwan


    Solid-phase extraction (SPE) coupled with gas chromatography/mass spectrometry (GC/MS) was used to determine the fosthiazate residue in water samples. The water samples were first filtered through cellulose filters (0.45 microm pore size). A 100 mL volume of filtered water, in which 1 mL of methanol has been added, was then passed through a pre-conditioned 3 cm C18 cartridge at a flow-rate of 1.5 mL/min. Elution was performed by 1 mL of methanol. The eluant was finally dried under reduced pressure for solvent evaporation. The volume was quantitatively adjusted to 0.5 mL with methanol. The analysis was carried out on GC/MS. The mass spectrometer was operated in selected ion monitoring (SIM) mode. According to mass spectrum of fosthiazate, three selected ions at m/z of 126, 195, 283, respectively, were monitored for identification and quantification. High sensitivity and selectivity were achieved by using this method. The limit of detection for fosthiazate in water samples was determined to be 56.4 ng/L. The linearity was demonstrated over a wide range of concentrations covering from 0.282 to 141 microg/L. The recoveries were more than 85.5% and the relative standard deviations for the overall procedure were less than 4.42%. The fosthiazate residue was detected in the water samples from a pool near cropland where fosthiazate was used. The results demonstrate the suitability of the SPE-GC/MS approach for the analysis of fosthiazate in water.

  18. Fast extraction of amphenicols residues from raw milk using novel fabric phase sorptive extraction followed by high-performance liquid chromatography-diode array detection. (United States)

    Samanidou, Victoria; Galanopoulos, Lavrentis-Demetrios; Kabir, Abuzar; Furton, Kenneth G


    A simple, sensitive, reliable, and fast analytical method was developed for the simultaneous determination of amphenicols residues in raw milk by combining fabric phase sorptive extraction (FPSE) and high-performance liquid chromatography-diode array detection. FPSE, a new generation green sample preparation technique, efficiently incorporates the advanced and tunable material properties of sol-gel derived microextraction sorbents with the rich surface chemistry of a cellulose fabric substrate, resulting in a flexible, highly sensitive, and fast microextraction device capable of extracting target analytes directly from complicated sample matrices. Due to the strong chemical bonding between the sol-gel sorbent and substrate, the microextraction device demonstrates a very high chemical and solvent stability. Therefore, any organic solvent/solvent mixture can be used as the eluent/back-extraction solvent. Herein, a highly polar polymer coated FPSE media was created using short-chain poly(ethylene glycol) (PEG) and the applicability of this novel microextraction device to extract highly polar amphenicol antibiotics from raw milk was investigated. Due to the intense affinity of amphenicols towards the strongly polar sol-gel PEG-coated FPSE device, absolute recovery of the selected antibiotics residues were found to be 44% for thiamphenicol, 66.4% for florfenicol, and 81.4% for chloramphenicol. The developed method was validated in terms of sensitivity, linearity, accuracy, precision, and selectivity according to European Decision 657/2002/EC. Decision limit (CCα) values were 52.49 μg kg(-1) for thiamphenicol, 55.23 μg kg(-1) for florfenicol, and 53.8 μg kg(-1) for chloramphenicol, while the corresponding results for detection capability (CCβ) were 56.8 μg kg(-1), 58.99 μg kg(-1), and 55.9 μg kg(-1), respectively. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Oxygen electrocatalysts in metal-air batteries: from aqueous to nonaqueous electrolytes. (United States)

    Wang, Zhong-Li; Xu, Dan; Xu, Ji-Jing; Zhang, Xin-Bo


    With the development of renewable energy and electrified transportation, electrochemical energy storage will be more important in the future than it has ever been in the past. Although lithium-ion batteries (LIBs) are traditionally considered to be the most likeliest candidate thanks to their relatively long cycle life and high energy efficiency, their limited energy density as well as cost are still causing a bottleneck for their long-term application. Alternatively, metal-air batteries have been proposed as a very promising large-scale electricity storage technology with the replacement of the intercalation reaction mechanism by the catalytic redox reaction of a light weight metal-oxygen couple. Generally, based on the electrolyte, these metal-air batteries can be divided into aqueous and nonaqueous systems, corresponding to two typical batteries of Zn-air and Li-air, respectively. The prominent feature of both batteries are their extremely high theoretical energy density, especially for nonaqueous Li-air batteries, which far exceeds the best that can be achieved with LIBs. In this review, we focus on the major obstacle of sluggish kinetics of the cathode in both batteries, and summarize the fundamentals and recent advances related to the oxygen catalyst materials. According to the electrolyte, the aqueous and nonaqueous electrocatalytic mechanisms of the oxygen reduction and evolution reactions are discussed. Subsequently, seven groups of oxygen catalysts, which have played catalytic roles in both systems, are selectively reviewed, including transition metal oxides (single-metal oxides and mixed-metal oxides), functional carbon materials (nanostructured carbons and doped carbons), metal oxide-nanocarbon hybrid materials, metal-nitrogen complexes (non-pyrolyzed and pyrolyzed), transition metal nitrides, conductive polymers, and precious metals (alloys). Nonaqueous systems have the advantages of energy density and rechargeability over aqueous systems and have

  20. Flow of microemulsion through soil columns contaminated with asphaltic residue; Fluxo de microemulsoes atraves do solo contaminado com residuos asfalticos

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Marcia C.K.; Oliveira, Jose F. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE); Oliveira, Roberto C.G.; Gonzalez, Gazpar [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas


    Nowadays, soil contamination with nonaqueous phase liquids (NAPLs) such as petroleum hydrocarbons is a major environmental problem. Significant efforts have been devoted to the development of processes to remediate sites contaminated with NAPLs. Unfortunately, most of the developed processes proved to be inefficient to remove the organic heavy fraction present in the NAPLs. Nevertheless, in our preliminary bench scale tests it was observed that, due to their high solubilization capacity and stability, microemulsions are able to remove organic heavy fractions like asphaltenes and resins, typically present in crude oils. The present work was dimensioned to evaluate, under up-flow condition, the performance of different microemulsions specially designed to remove asphaltenes fractions from soils using a column test set-up. The contaminant residual concentration was quantified by UV spectroscopy and the microemulsion efficiency determined using mass balance. The results showed that the microemulsions tested have a high capacity for removing asphaltenes fractions from contaminated soils. It was also observed that the predominant removal mechanism, solubilization or mobilization, depends essentially on the microemulsion's chemical formulation. Finally it was verified that microemulsion's formulations based on natural solvents compounds are also efficient for removing asphaltic residues. (author)

  1. Dispersive solid-phase extraction cleanup combined with accelerated solvent extraction for the determination of carbamate pesticide residues in Radix Glycyrrhizae samples by UPLC-MS-MS. (United States)

    Yang, Ru-zhen; Wang, Jin-hua; Wang, Ming-lin; Zhang, Rong; Lu, Xiao-yu; Liu, Wei-hua


    Dispersive solid-phase extraction (DSPE) cleanup combined with accelerated solvent extraction (ASE) is described here as a new approach for the extraction of carbamate pesticides in Radix Glycyrrhizae samples prior to UPLC-MS-MS. In the DSPE-ASE method, 15 carbamate pesticides were extracted from Radix Glycyrrhizae samples with acetonitrile by the ASE method at 60 °C with a 5 min heating time and two static cycles. Cleanup of a 1 mL aliquot of the extract by the DSPE method used 20 mg PSA (primary secondary amine), 50 mg Al(2)O(3)-N, and 20 mg GCB (graphitized carbon black) (as cleanup sorbents) under the determined optimum conditions. The linearity of the method was in the range of 10 to 200 ng/mL with correlation coefficients (r(2)) of more than 0.996. The limits of detection were approximately 0.2 to 5.0 µg/kg. The method was successfully used for the analysis of target pesticides in Radix Glycyrrhizae samples. The recoveries of the carbamate pesticides at the spiking levels of 50, 100, and 200 µg/kg ranged from 79.7% to 99.3% with relative standard deviations lower than 10%. This multi-residue analytical method allows for a rapid, efficient, sensitive and reliable determination of target pesticides in Radix Glycyrrhizae and other medicinal herbs.

  2. Determination of Tetracycline Antibiotic Residues in Honey and Milk by Miniaturized Solid Phase Extraction Using Chitosan-Modified Graphitized Multiwalled Carbon Nanotubes. (United States)

    Xu, Jing-Jing; An, Mingrui; Yang, Rui; Tan, Zhijing; Hao, Jie; Cao, Jun; Peng, Li-Qing; Cao, Wan


    A rapid, simple, and strongly selective miniaturized solid phase extraction (SPE) technique, requiring only small amounts of sorbent (24 mg) and elution solvent (600 μL), coupled with ultrahigh-performance liquid chromatography and quadrupole time-of-flight mass spectrometry was developed for detecting tetracycline antibiotics. These analytes were extracted from honey and milk using chitosan-modified graphitized multiwalled carbon nanotubes (G-MWNTs) as the solid sorbent and acetonitrile/acetic acid (8:2, v/v) as the eluent in miniaturized SPE. Under the optimum experimental conditions, a satisfactory linearity (r(2) > 0.992) was obtained, and the limits of detection were in the range of 0.61-10.34 μg/kg for the analytes. The mean recoveries of the five tetracycline antibiotic residues in the real samples were between 81.5 and 101.4%. The results demonstrated that chitosan-modified G-MWNTs comprise a promising material for the enrichment of tetracycline antibiotics from complex food matrices.

  3. Determination of residual volatile organic compounds migrated from polystyrene food packaging into food simulant by headspace solid phase micro extraction-gas chromatography

    International Nuclear Information System (INIS)

    Mohd Marsin Sanagi; Ling, Susie Lu; Zalilah Nasir; Wan Aini Wan Ibrahim; Abu Naim, Ahmedy


    The residual styrene and other volatile organic compounds (VOCs) present in the polystyrene food packaging are of concern as these compounds have the potential to migrate into the food in contact. This work describes a method for quantitative determination of VOCs, namely styrene, toluene, ethyl benzene, iso-propylbenzene and n-propylbenzene that have migrated from polystyrene food packaging into food stimulant by gas chromatography-flame ionization detection (GC-FID). Headspace solid phase micro extraction (HS-SPME) technique was applied for migration test using water as food stimulant. The effects of extraction variables including sample volume, eluotropic strength, extraction temperature, extraction time, desorption time, sample agitation, and salt addition on the amounts of the extracted analyses were studied to obtain the optimal HS-SPME conditions. The optimized method was applied to test the VOCs migrated from polystyrene bowls and cups at storage temperatures ranging from 24 to 80 degree Celsius for 30 min. Styrene and ethyl benzene were found to migrate from the samples into the food stimulant. The migration of analyze was found to be strongly dependent upon the storage temperature. The HS-SPME is useful as an alternative method to determine the migration of VOCs from food packaging material into food stimulant. (author)

  4. Impact of microwave pre-treatment on the batch anaerobic digestion of two-phase olive mill solid residue: a kinetic approach

    International Nuclear Information System (INIS)

    Rincon, B.; Gonzalez de Canales, M.; Martin, A.; Borja, R.


    The effect of a microwave (MW) pre-treatment on two-phase olive mill solid residue (OMSR) or alperujo with a view to enhancing its anaerobic digestibility was studied. The MW pre-treatment was carried out at a power of 800 W and at a targeted temperature of 50 °C using different heating rates and holding times. The following specific energies were applied: 4377 kJ·kg TS−1 (MW1), 4830 kJ·kg TS−1 (MW2), 7170 kJ·kg TS−1 (MW3) and 7660 kJ·kg TS−1 (MW4). The maximum methane yield, 395±1 mL CH4·g VSadded−1, was obtained for MW4. The effect of the pre-treatment on the kinetics of the process was also studied. The methane production curves generated during the batch tests showed a first exponential stage and a second sigmoidal stage for all the cases studied. In the first stage, the kinetic constant for the pre-treatment MW1 was 54.8% higher than that obtained for untreated OMSR. [es

  5. Residuation theory

    CERN Document Server

    Blyth, T S; Sneddon, I N; Stark, M


    Residuation Theory aims to contribute to literature in the field of ordered algebraic structures, especially on the subject of residual mappings. The book is divided into three chapters. Chapter 1 focuses on ordered sets; directed sets; semilattices; lattices; and complete lattices. Chapter 2 tackles Baer rings; Baer semigroups; Foulis semigroups; residual mappings; the notion of involution; and Boolean algebras. Chapter 3 covers residuated groupoids and semigroups; group homomorphic and isotone homomorphic Boolean images of ordered semigroups; Dubreil-Jacotin and Brouwer semigroups; and loli

  6. NABTIT-a computer program for non-aqueous acid-base titration. (United States)

    Budevsky, O; Zikolova, T; Tencheva, J


    A program NABTIT written in BASIC has been developed for the treatment of data (ml/mV) obtained from potentiometric acid-base titrations in non-aqueous solvents. No preliminary information on equilibrium constants is required for the input. The treatment of the data is based on known equations and uses least-squares procedures. The essence of the method is to determine the equivalence volume (V(e)) accurately, and to use the data acquired by adding titrant after V(e) for the pH*-calibration of the non-aqueous potentiometric cell. As a by-product or the calculations, the pK* value of the substance titrated is also obtained, and in some cases the autoprotolysis constant of the medium (pK*(s)). Good agreement between experiment and theory was found in the treatment of data obtained for water and methanol-water mixtures.

  7. Modelling the aqueous and nonaqueous interfaces for CO2 electro-reduction over Sn catalysts (United States)

    Sheng, Tian; Sun, Shi-Gang


    In CO2 electroreduction, Sn catalysts with a high overpotential for hydrogen evolution reaction and a high selectivity towards formic acid formation are very attractive. Many efforts have been made for improving the catalytic performance and for understanding the mechanisms. In electrochemistry, the role of solvents for surface reactions was deserved to be investigated, in particular for some nonaqueous solvents. Here, we have modeled the aqueous (water) and nonaqueous (acetonitrile and dichloromethane) for investigation of CO2 electroreduction on Sn surface, by constrained ab initio molecular dynamics simulations and thermodynamic integrations, including a number of explicit solvent molecules in computational models. It was found that CO2 reduction is initiated from formate formation and solvents, in particular, water can effectively facilitate the reaction.

  8. Biamperometric analysis of nonaqueous scandium solutions containing lanthanides, lead and thorium

    International Nuclear Information System (INIS)

    Gevorgyan, A.M.; Talipov, Sh.T.; Kostylev, V.S.; Khadeev, V.A.; Nadol'skij, M.Ya.


    Investigated was a possibility of direct scandium titration in the presence of large rare earth quantities, and also a possibility of complexonometric scandium and rare earth sum determination at their joint presence in non-aqueous acetic acid solution. The titration was carried out at electrode voltage of 0.95V, background electrolyte concentration of lithium perchlorate being 0.2M. Non-aqueous magnesium complexonate was used as titrating reagent. Th and Pb complexonates are shown to be less stable as compared to Sc complexonate, and consequently, Th and Pb ions must not interfere with biamperometric titration of Sc ion. A method applied to analysis of binary mixture, containing scandium, and a method for model alloy and thortveitite mineral was developed. Well reproducible and precise enough results are obtained in all the cases. Ions of Bi, Cu, Cd, Zn, In, Ga and Ti interfere with determination

  9. Enzymes from solvent-tolerant microbes: useful biocatalysts for non-aqueous enzymology. (United States)

    Gupta, Anshu; Khare, S K


    Solvent-tolerant microbes are a newly emerging class that possesses the unique ability to thrive in the presence of organic solvents. Their enzymes adapted to mediate cellular and metabolic processes in a solvent-rich environment and are logically stable in the presence of organic solvents. Enzyme catalysis in non-aqueous/low-water media is finding increasing applications for the synthesis of industrially important products, namely peptides, esters, and other trans-esterification products. Solvent stability, however, remains a prerequisite for employing enzymes in non-aqueous systems. Enzymes, in general, get inactivated or give very low rates of reaction in non-aqueous media. Thus, early efforts, and even some recent ones, have aimed at stabilization of enzymes in organic media by immobilization, surface modifications, mutagenesis, and protein engineering. Enzymes from solvent-tolerant microbes appear to be the choicest source for studying solvent-stable enzymes because of their unique ability to survive in the presence of a range of organic solvents. These bacteria circumvent the solvent's toxic effects by virtue of various adaptations, e.g. at the level of the cytoplasmic membrane, by degradation and transformation of solvents, and by active excretion of solvents. The recent screening of these exotic microbes has generated some naturally solvent-stable proteases, lipases, cholesterol oxidase, cholesterol esterase, cyclodextrin glucanotransferase, and other important enzymes. The unique properties of these novel biocatalysts have great potential for applications in non-aqueous enzymology for a range of industrial processes.

  10. Multifunctional role of rare earth doping in optical materials: nonaqueous sol-gel synthesis of stabilized cubic HfO2 luminescent nanoparticles. (United States)

    Lauria, Alessandro; Villa, Irene; Fasoli, Mauro; Niederberger, Markus; Vedda, Anna


    In this work a strategy for the control of structure and optical properties of inorganic luminescent oxide-based nanoparticles is presented. The nonaqueous sol-gel route is found to be suitable for the synthesis of hafnia nanoparticles and their doping with rare earths (RE) ions, which gives rise to their luminescence either under UV and X-ray irradiation. Moreover, we have revealed the capability of the technique to achieve the low-temperature stabilization of the cubic phase through the effective incorporation of trivalent RE ions into the crystal lattice. Particular attention has been paid to doping with europium, causing a red luminescence, and with lutetium. Structure and morphology characterization by XRD, TEM/SEM, elemental analysis, and Raman/IR vibrational spectroscopies have confirmed the occurrence of the HfO2 cubic polymorph for dopant concentrations exceeding a threshold value of nominal 5 mol %, for either Lu(3+) or Eu(3+). The optical properties of the nanopowders were investigated by room temperature radio- and photoluminescence experiments. Specific features of Eu(3+) luminescence sensitive to the local crystal field were employed for probing the lattice modifications at the atomic scale. Moreover, we detected an intrinsic blue emission, allowing for a luminescence color switch depending on excitation wavelength in the UV region. We also demonstrate the possibility of changing the emission spectrum by multiple RE doping in minor concentration, while deputing the cubic phase stabilization to a larger concentration of optically inactive Lu(3+) ions. The peculiar properties arising from the solvothermal nonaqueous synthesis here used are described through the comparison with thermally treated powders.

  11. Online single particle analysis of ice particle residuals from mountain-top mixed-phase clouds using laboratory derived particle type assignment (United States)

    Schmidt, Susan; Schneider, Johannes; Klimach, Thomas; Mertes, Stephan; Schenk, Ludwig Paul; Kupiszewski, Piotr; Curtius, Joachim; Borrmann, Stephan


    In situ single particle analysis of ice particle residuals (IPRs) and out-of-cloud aerosol particles was conducted by means of laser ablation mass spectrometry during the intensive INUIT-JFJ/CLACE campaign at the high alpine research station Jungfraujoch (3580 m a.s.l.) in January-February 2013. During the 4-week campaign more than 70 000 out-of-cloud aerosol particles and 595 IPRs were analyzed covering a particle size diameter range from 100 nm to 3 µm. The IPRs were sampled during 273 h while the station was covered by mixed-phase clouds at ambient temperatures between -27 and -6 °C. The identification of particle types is based on laboratory studies of different types of biological, mineral and anthropogenic aerosol particles. The outcome of these laboratory studies was characteristic marker peaks for each investigated particle type. These marker peaks were applied to the field data. In the sampled IPRs we identified a larger number fraction of primary aerosol particles, like soil dust (13 ± 5 %) and minerals (11 ± 5 %), in comparison to out-of-cloud aerosol particles (2.4 ± 0.4 and 0.4 ± 0.1 %, respectively). Additionally, anthropogenic aerosol particles, such as particles from industrial emissions and lead-containing particles, were found to be more abundant in the IPRs than in the out-of-cloud aerosol. In the out-of-cloud aerosol we identified a large fraction of aged particles (31 ± 5 %), including organic material and secondary inorganics, whereas this particle type was much less abundant (2.7 ± 1.3 %) in the IPRs. In a selected subset of the data where a direct comparison between out-of-cloud aerosol particles and IPRs in air masses with similar origin was possible, a pronounced enhancement of biological particles was found in the IPRs.

  12. Light Nonaqueous-Phase Liquid Weathering at Various Fuel Release Sites, 2003 Update (United States)


    exist (e.g., the groundwater concentration of benzene is significantly less than its effective solubility [ Table 2.1]), the dissolution rate cannot be...for ethylbenzene, most likely as a result of its lower effective water solubility TABLE 5.4 FUEL COMPONENT (ONE POINT)a/ WEATHERING RATES IN JP-8

  13. Multiphase flow and enhanced biodegradation of dense non-aqueous phase liquids. Geologica Ultraiectina (303)

    NARCIS (Netherlands)

    Langevoort, M.


    Soil and groundwater pollution by chlorinated solvents, such as tetrachloroethylene (PCE) are common throughout the industrialized world. These so called DNAPLs pose environmental health risks and sites contaminated with DNAPLs often require remediation. One of the most effective and economically

  14. In-Situ Characterization of Dense Non-Aqueous Phase Liquids Using Partitioning Tracers

    Energy Technology Data Exchange (ETDEWEB)

    Gary A. Pope; Daene C. McKinney; Akhil Datta Gupta; Richard E. Jackson; Minquan Jin


    Majors advances have been made during the past three years in our research on interwell partitioning tracers tests (PITTs). These advances include (1) progress on the inverse problem of how to estimate the three-dimensional distribution of NAPL in aquifers from the tracer data, (2) the first ever partitioning tracer experiments in dual porosity media, (3) the first modeling of partitioning tracers in dual porosity media (4) experiments with complex NAPLs such as coal tar, (5) the development of an accurate and simple method to predict partition coefficients using the equivalent alkane carbon number approach, (6) partitioning tracer experiments in large model aquifers with permeability layers, (7) the first ever analysis of partitioning tracer data to estimate the change in composition of a NAPL before and after remediation (8) the first ever analysis of partitioning tracer data after a field demonstration of surfactant foam to remediate NAPL and (9) experiments at elevated temperatures .

  15. Sensitive Capillary Electrophoresis Microchip Determination of Trinitroaromatic Explosives in Nonaqueous Electrolyte Following Solid Phase Extraction

    National Research Council Canada - National Science Library

    Lu, Qin


    ...), 2.5 mM NaOH, 1 mM sodium dodecyl sulfate (sDs)). The chemical reaction of bases, e.g. hydroxide or methoxide ions, with trinitroaromatic compounds forms red colored derivatives that can be easily detected using a green light emitting diode...

  16. Dense Non-Aqueous Phase Liquids (DNAPLs): Review of Emerging Characterization and Remediation Technologies (United States)


    hazardous substances like creosote and coal tar. Not ordinarily released into the environment as pure or neat chemicals, DNAPLs are often discharged...of in situ treatment methods, including flushing, thermally enhanced methods, chemical oxidation, bioremediation , and sparging/vapor extraction...Laboratory work has also demonstrated applicability for coal tar/ creosote and PCB-containing mineral oils. • Design of in situ flushing can benefit from


    This issue paper provides a comprehensive literature review regarding the compatibility of NAPLs with a wide variety of materials used at hazardous waste sites. A condensed reference table of compatibility data for 207 chemicals and 28 commonly used well construction and sampling...

  18. Application of non-aqueous solvents to batteries (United States)

    Singh, P.


    The successful application of organic and aquo-organic solvents in lithium batteries and in zinc bromine batteries is discussed. Results are presented for a comparison of propylene carbonate and 50 percent propylene carbonate/acetonitrile for lithium intercalation cells at 25 C 1 M LiAsF6 as electrolyte and discharge at 2 mA/sq cm. Higher cathode utilization and energy efficiencies are achieved in PC/AN. It was found that the self-discharge problem of the zinc/bromine battery may be overcome by dissolving bromine and bromide salt in water-immiscible dipolar aprotic solvent-proprionitrile (PN). Cells using this PN/H2O two-phase system have an energy efficiency above 75 percent and coulombic efficiency above 85 percent.

  19. The Effect of Water on Quinone Redox Mediators in Nonaqueous Li-O2 Batteries. (United States)

    Liu, Tao; Frith, James T; Kim, Gunwoo; Kerber, Rachel N; Dubouis, Nicolas; Shao, Yuanlong; Liu, Zigeng; Magusin, Pieter C M M; Casford, Michael T L; Garcia-Araez, Nuria; Grey, Clare P


    The parasitic reactions associated with reduced oxygen species and the difficulty in achieving the high theoretical capacity have been major issues plaguing development of practical nonaqueous Li-O 2 batteries. We hereby address the above issues by exploring the synergistic effect of 2,5-di-tert-butyl-1,4-benzoquinone and H 2 O on the oxygen chemistry in a nonaqueous Li-O 2 battery. Water stabilizes the quinone monoanion and dianion, shifting the reduction potentials of the quinone and monoanion to more positive values (vs Li/Li + ). When water and the quinone are used together in a (largely) nonaqueous Li-O 2 battery, the cell discharge operates via a two-electron oxygen reduction reaction to form Li 2 O 2 , with the battery discharge voltage, rate, and capacity all being considerably increased and fewer side reactions being detected. Li 2 O 2 crystals can grow up to 30 μm, more than an order of magnitude larger than cases with the quinone alone or without any additives, suggesting that water is essential to promoting a solution dominated process with the quinone on discharging. The catalytic reduction of O 2 by the quinone monoanion is predominantly responsible for the attractive features mentioned above. Water stabilizes the quinone monoanion via hydrogen-bond formation and by coordination of the Li + ions, and it also helps increase the solvation, concentration, lifetime, and diffusion length of reduced oxygen species that dictate the discharge voltage, rate, and capacity of the battery. When a redox mediator is also used to aid the charging process, a high-power, high energy density, rechargeable Li-O 2 battery is obtained.

  20. DFT Study On Effects of CO2 Contamination in Non-Aqueous Li-Air Batteries

    DEFF Research Database (Denmark)

    Mekonnen, Yedilfana Setarge; Mýrdal, Jón Steinar Garðarsson; Vegge, Tejs


    Density Functional Theory (DFT) studies on the effects of carbon dioxide (CO2) contamination at the cathode of rechargeable non-aqueous Li-O2 batteries, where the insulating material Lithium peroxide (Li2O2) is the main discharge product. The Li2O2 growth mechanism and overpotentials...... and result in an increased battery capacity. However, CO2 contamination on the Li2O2 surface confirms an asymmetric increase in the overpotentials; particularly the charging overvoltage exhibits sustantial increase, which would reduce the efficiency of the Li-air battery....

  1. Electrochemical deposition of coatings of highly entropic alloys from non-aqueous solutions

    Directory of Open Access Journals (Sweden)

    Jeníček V.


    Full Text Available The paper deals with electrochemical deposition of coatings of highly entropic alloys. These relatively new materials have been recently intensively studied. The paper describes the first results of electrochemical coating with highly entropic alloys by deposition from non-aqueous solutions. An electrochemical device was designed and coatings were deposited. The coatings were characterised with electronic microscopy scanning, atomic absorption spectrometry and X-ray diffraction methods and the combination of methods of thermic analysis of differential scanning calorimetry and thermogravimetry.

  2. High voltage rechargeable magnesium batteries having a non-aqueous electrolyte (United States)

    Doe, Robert Ellis; Lane, George Hamilton; Jilek, Robert E.; Hwang, Jaehee


    A rechargable magnesium battery having an non-aqueous electrolyte is provided. The properties of the electrolyte include high conductivity, high Coulombic efficiency, and an electrochemical window that can exceed 3.5 V vs. Mg/Mg.sup.+2. The use of the electrolyte promotes the electrochemical deposition and dissolution of Mg without the use of any Grignard reagents, other organometallic materials, tetraphenyl borate, or tetrachloroaluminate derived anions. Other Mg-containing electrolyte systems that are expected to be suitable for use in secondary batteries are also described.

  3. Toward direct pore-scale modeling of three-phase displacements (United States)

    Mohammadmoradi, Peyman; Kantzas, Apostolos


    A stable spreading film between water and gas can extract a significant amount of bypassed non-aqueous phase liquid (NAPL) through immiscible three-phase gas/water injection cycles. In this study, the pore-scale displacement mechanisms by which NAPL is mobilized are incorporated into a three-dimensional pore morphology-based model under water-wet and capillary equilibrium conditions. The approach is pixel-based and the sequence of invasions is determined by the fluids' connectivity and the threshold capillary pressure of the advancing interfaces. In addition to the determination of three-phase spatial saturation profiles, residuals, and capillary pressure curves, dynamic finite element simulations are utilized to predict the effective permeabilities of the rock microtomographic images as reasonable representations of the geological formations under study. All the influential features during immiscible fluid flow in pore-level domains including wetting and spreading films, saturation hysteresis, capillary trapping, connectivity, and interface development strategies are taken into account. The capabilities of the model are demonstrated by the successful prediction of saturation functions for Berea sandstone and the accurate reconstruction of three-phase fluid occupancies through a micromodel.

  4. Residual risk

    African Journals Online (AJOL)

    ing the residual risk of transmission of HIV by blood transfusion. An epidemiological approach assumed that all HIV infections detected serologically in first-time donors were pre-existing or prevalent infections, and that all infections detected in repeat blood donors were new or incident infections. During 1986 - 1987,0,012%.

  5. Multi-phase flow modeling of soil contamination and soil remediation

    NARCIS (Netherlands)

    Dijke, van M.I.J.


    In this thesis multi-phase flow models are used to study the flow behavior of liquid contaminants in aquifers and of gases that are injected below the groundwater table for remediation purposes. Considered problems are redistribution of a lens of light nonaqueous phase

  6. A numerical investigation into factors affecting gas and aqueous phase plumes in the subsurface (United States)

    Thomson, N. R.; Sykes, J. F.; Van Vliet, D.


    An investigation into the face and transport of volatile organic compounds (VOCs) in the subsurface requires the consideration of contaminant mass in both the aqueous and soil gas phases. As a result of water/gas phase partitioning, contaminated by partitioning from underlying ground water pollution. Conversely, soil gas can be contaminated by partitioning from underlying ground water VOC plumes. This soil gas and aqueous phase interaction has motivated the popularity of soil gas sampling technology as a method of characterizing ground water VOC contamination. A finite-element-based numerical model was developed to accurately simulate the interaction between the soil gas phase and the aqueous phase. This interaction is complicated since the saturation of the aqueous phase varies dramatically across the capillary fringe. The two-phase flow equations for gas and water are used to describe the flow regime, while the advective-dispersive transport of the VOC is considered in both phases. Dissolution and volatilization from a non-mobile non-aqueous phase liquid is included as a volatile organic contaminant source. A deforming mesh allows the model to accurately track the water table movement, and a Eularian-Lagrangian formulation is used to control some of the numerical difficulties associated with the numerical solution of the advection-dispersion equation. An investigation into diffusion of a VOC from below the water table demonstrated that both the frequency and the magnitude of water table fluctuations have a profound influence on the degree of soil gas contamination. Two-dimensional large-scale, long-term simulations were performed to estimate the aqueous and soil gas phase plumes resulting from an immobilized trichloroethylene residual located in the unsaturated zone. The simulation results indicate that these plumes are very sensitive to the vertical position of the contaminant source. In addition, it was determined that seasonal fluctuations in soil gas VOC

  7. Non-aqueous energy storage devices using graphene nanosheets synthesized by green route

    Directory of Open Access Journals (Sweden)

    Dattakumar Mhamane


    Full Text Available In this paper we report the use of triethylene glycol reduced graphene oxide (TRGO as an electrode material for non-aqueous energy storage devices such as supercapacitors and Li-ion batteries. TRGO based non–aqueous symmetric supercapacitor is constructed and shown to deliver maximum energy and power densities of 60.4 Wh kg–1 and 0.15 kW kg–1, respectively. More importantly, symmetric supercapacitor shows an extraordinary cycleability (5000 cycles with over 80% of capacitance retention. In addition, Li-storage properties of TRGO are also evaluated in half-cell configuration (Li/TRGO and shown to deliver a reversible capacity of ∼705 mAh g–1 with good cycleability at constant current density of 37 mA g–1. This result clearly suggests that green-synthesized graphene can be effectively used as a prospective electrode material for non-aqueous energy storage systems such as Li-ion batteries and supercapacitors.

  8. On-line stacking techniques for the nonaqueous capillary electrophoretic determination of acrylamide in processed food

    International Nuclear Information System (INIS)

    Tezcan, Filiz; Erim, F. Bedia


    In the present study, field amplified sample stacking (FASS) techniques in the nonaqueous capillary electrophoresis method (NACE) were introduced for the on-line concentration of the acrylamide to improve acrylamide detection at 210 nm by diode-array detection. Acetonitrile (ACN) as a nonaqueous solvent permits acrylamide to be protonated through the change of its acid-base chemistry, allowing capillary electrophoretic separation of this compound. Choosing 30 mmol L -1 HClO 4 , 20 mmol L -1 NaClO 4 , 218 mmol L -1 CH 3 COOH in ACN as the separation electrolyte and employing sample stacking methods, the LOD value of acrylamide was decreased to 2.6 ng mL -1 with electrokinetic injection and 4.4 ng mL -1 with hydrodynamic injection. Optimized stacking conditions were applied to the determination of acrylamide in several foodstuffs. The method is simple, rapid, inexpensive, and widely applicable for the determination of acrylamide in food samples

  9. Challenges and Prospect of Non-aqueous Non-alkali (NANA) Metal-Air Batteries. (United States)

    Gelman, Danny; Shvartsev, Boris; Ein-Eli, Yair


    Non-aqueous non-alkali (NANA) metal-air battery technologies promise to provide electrochemical energy storage with the highest specific energy density. Metal-air battery technology is particularly advantageous being implemented in long-range electric vehicles. Up to now, almost all the efforts in the field are focused on Li-air cells, but other NANA metal-air battery technologies emerge. The major concern, which the research community should be dealing with, is the limited and rather poor rechargeability of these systems. The challenges we are covering in this review are related to the initial limited discharge capacities and cell performances. By comprehensively reviewing the studies conducted so far, we show that the implementation of advanced materials is a promising approach to increase metal-air performance and, particularly, metal surface activation as a prime achievement leading to respectful discharge currents. In this review, we address the most critical areas that need careful research attention in order to achieve progress in the understanding of the physical and electrochemical processes in non-aqueous electrolytes applied in beyond lithium and zinc air generation of metal-air battery systems.

  10. Prediction of aqueous and nonaqueous solubilities of chemicals with environmental interest by UNIFAC

    International Nuclear Information System (INIS)

    Kan, A.T.; Tomson, M.B.


    This paper is to investigate the accuracy and precision of predicting the aqueous and non-aqueous solubilities of a vast number of chemicals with significant environmental roles using the latest version of UNIFAC group interaction parameters. A few critical measurements to test specific UNIFAC calculations of nonaqueous solubilities are also reported. The chemicals included in the calculation have aqueous solubilities that span eleven orders of magnitude. Good agreement was observed between the UNIFAC predicted and literature reported aqueous solubilities for eleven groups of compounds. Similarly, UNIFAC successfully predicts the co-solvency of PCB in methanol/water solutions. The error between predicted and literature reported aqueous solubilities was larger for three groups of chemicals: long chain alkanes, phthalates, and chlorinated alkenes. The average absolute error in UNIFAC precision of aqueous solubilities is about 0.5 log units, but the average absolute error is only about 0.2 log units for chlorinated aromatic compounds in organic solvents. The application of UNIFAC approach to predict the fate of hydrocarbons and PCBs in soil column flushing, cosolvency and in natural gas pipeline liquids will be discussed

  11. Evaluation of a Non-aqueous Ibuprofen-Phospholipid Complex Formulation in Rats. (United States)

    Li, Chunhua; Xu, Songlin; Liu, Zhidong; Ding, Lingling; Zhao, Xiaobin; Lee, Robert J


    In the present study, a non-aqueous ibuprofen-phospholipid complex was developed to reduce the gastrointestinal (GI) toxicity of ibuprofen. A non-aqueous ibuprofen-phospholipid complex (IBU-PC) was prepared by mixing phosal-35SB and ibuprofen. In vitro release behavior was studied using a dissolution apparatus. Irritation to gastrointestinal (GI) tract and pharmacokinetics of IBU-PC were studied in rats. Rapid release of drug occurred with approximately 85% of ibuprofen released from the composition within the first 30 min. The GI injury in IBU-PC-treated rats was minimal compared to those of Advil Liqui-gels-treated group. There was no significant difference between IBU-PC and Motrin-treated groups. The area under the concentration-time curve (AUC0~24) of IBU-PC and Motrin were 366±115 and 391±105 μg/h/ml, respectively. The relative bioavailability of IBU-PC was 94.2%. IBU-PC can decrease GI adverse reaction induced by ibuprofen. Copyright © 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  12. SRC Residual fuel oils (United States)

    Tewari, Krishna C.; Foster, Edward P.


    Coal solids (SRC) and distillate oils are combined to afford single-phase blends of residual oils which have utility as fuel oils substitutes. The components are combined on the basis of their respective polarities, that is, on the basis of their heteroatom content, to assure complete solubilization of SRC. The resulting composition is a fuel oil blend which retains its stability and homogeneity over the long term.

  13. Comparison of an acetonitrile extraction/partitioning and “dispersive solid-phase extraction” method with classical multi-residue methods for the extraction of herbicide residues in barley samples

    NARCIS (Netherlands)

    Diez, C.; Traag, W.A.; Zommer, P.; Marinero, P.; Atienza, J.


    An acetonitrile/partitioning extraction and "dispersive solid-phase extraction (SPE)" method that provides high quality results with a minimum number of steps and a low solvent and glassware consumption was published in 2003. This method, suitable for the analysis of multiple classes of pesticide

  14. Residual basins

    International Nuclear Information System (INIS)

    D'Elboux, C.V.; Paiva, I.B.


    Exploration for uranium carried out over a major portion of the Rio Grande do Sul Shield has revealed a number of small residual basins developed along glacially eroded channels of pre-Permian age. Mineralization of uranium occurs in two distinct sedimentary units. The lower unit consists of rhythmites overlain by a sequence of black shales, siltstones and coal seams, while the upper one is dominated by sandstones of probable fluvial origin. (Author) [pt

  15. High-activity MgO-supported CoMo Hydrodesulfurization Catalysts Prepared by Non-aqueous Impregnation

    Czech Academy of Sciences Publication Activity Database

    Kaluža, Luděk; Gulková, Daniela; Vít, Zdeněk; Zdražil, Miroslav


    Roč. 162, JAN 2015 (2015), s. 430-436 ISSN 0926-3373 R&D Projects: GA ČR GAP106/11/0902 Institutional support: RVO:67985858 Keywords : CoMo/MgO * benzothiophene hydrodesulfurization * non-aqueous impregnation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 8.328, year: 2015

  16. Highly Conducting Nanosized Monodispersed Antimony-Doped Tin Oxide Particles Synthesized via Nonaqueous Sol−Gel Procedure

    Czech Academy of Sciences Publication Activity Database

    Müller, V.; Rasp, M.; Štefanić, G.; Ba, J.; Günther, S.; Rathouský, Jiří; Niederberger, M.; Fattakhova Rohlfing, D.


    Roč. 21, č. 21 (2009), s. 5229-5236 ISSN 0897-4756 Institutional research plan: CEZ:AV0Z40400503 Keywords : nanoparticles * nonaqueous Ssl-gel procedure * oxide materials Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.368, year: 2009

  17. Pyroacm Resin: An Acetamidomethyl Derived Resin for Solid Phase Synthesis of Peptides through Side Chain Anchoring of C-Terminal Cysteine Residues. (United States)

    Juvekar, Vinayak; Gong, Young Dae


    The design, synthesis and utilization of an efficient acetamidomethyl derived resin for the peptide synthesis is presented using established Fmoc and Boc protocols via side chain anchoring. Cleavage of the target peptide from the resin is performed using carboxymethylsulfenyl chloride under mild conditions which gave in situ thiol-sulfenyl protection of the cysteine residues. The utility of the resin is successfully demonstrated through applications to the syntheses of model peptides and natural products Riparin 1.1 and Riparin 1.2.

  18. Development and validation of a high-performance liquid chromatography method for determination of ractopamine residue in pork samples by solid phase extraction and pre-column derivatization. (United States)

    Ding, Guanglong; Li, Deguang; Qin, Jiao; Zhu, Juanli; Wang, Baitao; Geng, Qianqian; Guo, Mingcheng; Punyapitak, Darunee; Cao, Yongsong


    Ractopamine (RAC) has been approved as a feed additive for swine, cattle or turkey, and is likely to have residue in edible animal products and may pose a potential risk for consumer health. Therefore, it is essential to establish a method to detect the residue of RAC in animal products. This work presents a rapid and sensitive HPLC method for the determination of RAC in pork samples with pre-column derivatization. The RAC derivative was separated on a kromasil C18 column and detected at 284nm with a UV detector. The detection capability (CCβ) was 0.078μgg(-1) and the linearity was established over the concentration range of 0.15-100.0μgg(-1). The overall mean recovery in spike range of 0.2μgg(-1) to 100μgg(-1) was 89.9% with the overall mean relative standard deviation of 4.1%. This method can be used for the quantification of RAC in pork samples and help to establish adequate monitoring of the residue of RAC. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Transoral robotic surgery for residual and recurrent oropharyngeal cancers: Exploratory study of surgical innovation using the IDEAL framework for early-phase surgical studies. (United States)

    Paleri, Vinidh; Fox, Hannah; Coward, Sarah; Ragbir, Maniram; McQueen, Andrew; Ahmed, Omar; Meikle, David; Saleh, Daniel; O'Hara, James; Robinson, Max


    The purpose of this study was to identify the role of transoral robotic surgery (TORS) in the management of residual and recurrent oropharyngeal cancer. IDEAL (Idea, Development, Exploration, Assessment, Long-term Follow-up) 2a framework. Of 26 patients assessed for TORS, 21 underwent the procedure, 5 underwent open resection (4 due to unsuitable anatomy/tumor extent and 1 on the basis of patient choice). Three patients underwent intraoperative ultrasound-assisted robotic resection, and 3 received robotic-assisted free flap inset. A technical refinement for TORS of residual and recurrent oropharyngeal cancer of the tongue base is described. Actuarial plots showed estimated overall survival of 48.2%, local control of 76.6%, and disease-specific survival of 77.1% at 42.6 months. TORS is a valid management option for residual and recurrent oropharyngeal cancer. Oncologic outcomes are comparable to open surgery and transoral laser microsurgery, with the added advantages of en bloc resections, facility for intraoperative ultrasound imaging, and inset of free flaps without mandibular split. © 2017 Wiley Periodicals, Inc.

  20. Nonaqueous ionic liquids: superior reaction media for the catalytic Heck-vinylation of chloroarenes (United States)

    Bohm; Herrmann


    Nonaqueous ionic liquids, that is molten salts, constitute an activating and stabilizing noninnocent solvent for the palladium-catalyzed Heck-vinylation of all types of aryl halides. Especially with chloroarenes an improved activity and stability of almost any known catalyst system is observed as compared to conventional, molecular solvents (e.g. dimethylformamide (DMF), dimethylacetamide (DMAc), N-methyl-2-pyrrolidinone (NMP), or dioxane). Thus, even catalytic amounts of ligand-free PdCl2 yield stilbene from technically interesting chlorobenzene and styrene in high yield (turnover number (TON) = 18) without the need for further promoting salt additives such as tetraphenylphosphonium chloride. The scope of the new reaction medium is outlined for the first time for the vinylation of various aryl halides using different mono- and disubstituted olefins as well as a variety of known palladium(0) and palladium(II) catalyst systems. Furthermore, a novel means of catalyst recycling is presented and its scope is evaluated.

  1. Alkaline and non-aqueous proton-conducting pouch-cell batteries

    Energy Technology Data Exchange (ETDEWEB)

    Young, Kwo-hsiung; Nei, Jean; Meng, Tiejun


    Provided are sealed pouch-cell batteries that are alkaline batteries or non-aqueous proton-conducing batteries. A pouch cell includes a flexible housing such as is used for pouch cell construction where the housing is in the form of a pouch, a cathode comprising a cathode active material suitable for use in an alkaline battery, an anode comprising an anode active material suitable for use in an alkaline battery, an electrolyte that is optionally an alkaline or proton-conducting electrolyte, and wherein the pouch does not include or require a safety vent or other gas absorbing or releasing system as the anode active material and the cathode active material do not increase the internal atmospheric pressure any more than 2 psig during cycling. The batteries provided function contrary to the art recognized belief that such battery systems were impossible due to unacceptable gas production during cycling.

  2. A novel green nonaqueous sol-gel process for preparation of partially stabilized zirconia nanopowder

    Directory of Open Access Journals (Sweden)

    Guo Feng


    Full Text Available A novel green nonaqueous sol-gel process was developed to prepare 3 mol% Y2O3-doped ZrO2 nanopowder from zirconium oxychloride and without need for washing of the obtained particles. It was shown that highly dispersive nanometer-scale zirconia powder with the particle size of 15–25 nm and BET surface area of 41.2 m2/g can be prepared. The sintering behaviour was also investigated. Density of the translucent body sintered at 1400 °C is 98.7 ± 0.3% of its theoretical density and the surface and cross section areas are dense without holes or other defects. The bending strength of the sintered sample is 928 ± 64 MPa.

  3. Molecular dynamics investigation of carbon nanotube junctions in non-aqueous solutions

    KAUST Repository

    Gkionis, Konstantinos


    The properties of liquids in a confined environment are known to differ from those in the bulk. Extending this knowledge to geometries defined by two metallic layers in contact with the ends of a carbon nanotube is important for describing a large class of nanodevices that operate in non-aqueous environments. Here we report a series of classical molecular dynamics simulations for gold-electrode junctions in acetone, cyclohexane and N,N-dimethylformamide solutions and analyze the structure and the dynamics of the solvents in different regions of the nanojunction. The presence of the nanotube has little effect on the ordering of the solvents along its axis, while in the transversal direction deviations are observed. Importantly, the orientational dynamics of the solvents at the electrode-nanotube interface differ dramatically from that found when only the electrodes are present.

  4. Carbon dioxide assist for non-aqueous sodium–oxygen batteries

    KAUST Repository

    Das, Shyamal K.


    We report a novel non-aqueous Na-air battery that utilizes a gas mixture of CO2 and O2. The battery exhibits a high specific energy of 6500-7000 Whkg- 1 (based on the carbon mass) over a range of CO2 feed compositions. The energy density achieved is higher, by 200% to 300%, than that obtained in pure oxygen. Ex-situ FTIR and XRD analysis reveal that Na2O2, Na2C2O 4 and Na2CO3 are the principal discharge products. The Na-CO2/O2 and Mg-CO2/O 2 battery platforms provide a promising, new approach for CO 2 capture and generation of electrical energy. © 2012 Elsevier B.V. All rights reserved.

  5. Acid-base and coordination properties of Meso-substituted porphyrins in nonaqueous solutions (United States)

    Pukhovskaya, S. G.; Nam, Dao Tkhe; Fien, Chan Ding; Domanina, E. N.; Ivanova, Yu. B.; Semeikin, A. S.


    Acid-base and coordination properties of alkyl and aryl meso-substituted porphyrins are studied spectrophotometrically in nonaqueous solutions. It is found that the nature of the substituent greatly affects the basicity of ligands for porphyrins characterized by a flat structure of macrocycle. The electronic effects of substituents have a much weaker influence on the kinetics of complexing. These effects could be due to the opposite orientation of some factors: an increase in the basicity and stability of the N-H bonds of porphyrin reaction centers. Dissociation constants p K b of the cationic forms of meso-substituted derivatives of porphyrin are measured. The values of p K b are in good agreement with classic concepts of the nature of substituents, particularly those indirectly included in the macrocycle through phenyl buffer rings.

  6. Electrodeposition fabrication of Co-based superhydrophobic powder coatings in non-aqueous electrolyte (United States)

    Chen, Zhi; Hao, Limei; Duan, Mengmeng; Chen, Changle


    A rapid, facile, one-step process was developed to fabricate Co-based superhydrophobic powder coatings on the stainless steel surfaces with a nonaqueous electrolyte by the electrodeposition method. The structure and composition of the superhydrophobic surfaces were characterized by means of scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and contact angle measurement. The results show that the special hierarchical structures along with the low surface energy lead to the high superhydrophobicity of the substrate surface. The shortest process of constructing the superhydrophobic surface is only 30 seconds, the high contact angle is greater than 160°, and the rolling angle is less than 2°. The method can be used to fabricate the superhydrophobic powder coatings at any conductive cathodic surface, and the as-prepared superhydrophobic powder coatings have advantages of transferability, repairability, and durability. It is expected that this facile method will accelerate the large-scale production of superhydrophobic material.

  7. Influence of clay, surfactant and presence of dispersant in the non-aqueous fluids rheology

    International Nuclear Information System (INIS)

    Gomes, N.L.; Guedes, I.C.; Menezes, R.R.; Campos, L.F.A.; Ferreira, H.S.


    The bentonite clay used as a thickening agent in production of non-aqueous fluids and can not be used without a prior treatment to their organic surfaces become hydrophobic. These treated clays are called organoclays, and are usually obtained by adding, in aqueous solution, a quaternary ammonium salt. This work makes a detailed study of the variables involved in the dispersion of the bentonite clays in organophilization process, as well, the type of clay, type of surfactant and the presence of dispersant. It was observed this study that the process variables involved in the dispersion of the clays and organophilization, observed through characterization, have low influence on the peaks related to interplanar basal distance caused by the incorporation of the surfactant and bentonite clays been influential the type of clay and surfactant and the presence of sodium as dispersant agent, on the rheological properties. (author)


    Directory of Open Access Journals (Sweden)

    A. Zuber


    Full Text Available AbstractThe correlation of thermodynamic properties of nonaqueous electrolyte solutions is relevant to design and operation of many chemical processes, as in fertilizer production and the pharmaceutical industry. In this work, the Q-electrolattice equation of state (EOS is used to model vapor pressure, mean ionic activity coefficient, osmotic coefficient, and liquid density of sixteen methanol and ten ethanol solutions containing single strong 1:1 and 2:1 salts. The Q-electrolattice comprises the lattice-based Mattedi-Tavares-Castier (MTC EOS, the Born term and the explicit MSA term. The model requires two adjustable parameters per ion, namely the ionic diameter and the solvent-ion interaction energy. Predictions of osmotic coefficient at 298.15 K and liquid density at different temperatures are also presented.

  9. Ceria based catalyst for cathode in non-aqueous electrolyte based Li/O2 batteries (United States)

    Kalubarme, Ramchandra S.; Cho, Min-Seung; Kim, Jae-Kook; Park, Chan-Jin


    This study suggests combustion synthesized Ce1-xZrxO2 (CZO; x = 0.1-0.5) as a new catalyst for the cathode in non-aqueous electrolyte based Li/O2 cells. The spherical catalysts have a fluorite structure with a mean diameter of 5-17 nm. Zr doping into the ceria lattice leads to the reduction of Ce4+ to Ce3+, which further improves the catalyst performance. Electrochemical studies of CZO as a cathode catalyst in the Li/O2 cell show that CZO follows a two-electron pathway for oxygen reduction. A maximum discharge capacity of 1620 mAh g-1 is obtained for the Ce0.8Zr0.2O2 catalyst due to its high surface area and porosity. A composite of CZO and MnO2 shows even better performance as a cathode catalyst for the Li/O2 cell.

  10. High frequency titration in non-aqueous solvents. Application to HF and UF6

    International Nuclear Information System (INIS)

    Neveu, Claude


    In this research thesis, the author first presents the main theoretical notions regarding high frequency titration, notably by studying characteristic curves, i.e. the titration meter indication with respect to conductibility. He reports the use of this method for the study of various reactions in non-aqueous medium: reaction of AlCl 3 with pyridine in acetonitrile, of AlCl 3 with HCl in tetrachloroethane and in nitromethane. He also reports the attempt of application of this method to the titration of HF in presence of UF 6 in CCl 4 as solvent, or by using F acceptors like BF 3 , PF 5 or ClF 3 as reactants [fr


    This source category previously subjected to a technology-based standard will be examined to determine if health or ecological risks are significant enough to warrant further regulation for Coke Ovens. These assesments utilize existing models and data bases to examine the multi-media and multi-pollutant impacts of air toxics emissions on human health and the environment. Details on the assessment process and methodologies can be found in EPA's Residual Risk Report to Congress issued in March of 1999 (see web site). To assess the health risks imposed by air toxics emissions from Coke Ovens to determine if control technology standards previously established are adequately protecting public health.

  12. Application of a hybrid ordered mesoporous silica as sorbent for solid-phase multi-residue extraction of veterinary drugs in meat by ultra-high-performance liquid chromatography coupled to ion-trap tandem mass spectrometry. (United States)

    Casado, Natalia; Morante-Zarcero, Sonia; Pérez-Quintanilla, Damián; Sierra, Isabel


    A quick, sensitive and selective analytical reversed-phase multi-residue method using ultra-high performance liquid chromatography coupled to an ion-trap mass spectrometry detector (UHPLC-IT-MS/MS) operating in both positive and negative ion mode was developed for the simultaneous determination of 23 veterinary drug residues (β-blockers, β-agonists and Non-Steroidal Anti-inflammatory Drugs (NSAIDs)) in meat samples. The sample treatment involved a liquid-solid extraction followed by a solid-phase extraction (SPE) procedure. SBA-15 type mesoporous silica was synthetized and modified with octadecylsilane, and the resulting hybrid material (denoted as SBA-15-C18) was applied and evaluated as SPE sorbent in the purification of samples. The materials were comprehensively characterized, and they showed a high surface area, high pore volume and a homogeneous distribution of the pores. Chromatographic conditions and extraction procedure were optimized, and the method was validated according to the Commission Decision 2002/657/EC. The method detection limits (MDLs) and the method quantification limits (MQLs) were determined for all the analytes in meat samples and found to range between 0.01-18.75μg/kg and 0.02-62.50μg/kg, respectively. Recoveries for 15 of the target analytes ranged from 71 to 98%. In addition, for comparative purpose SBA-15-C18 was evaluated towards commercial C18 amorphous silica. Results revealed that SBA-15-C18 was clearly more successful in the multi-residue extraction of the 23 mentioned analytes with higher recovery values. The method was successfully tested to analyze prepacked preparations of mince bovine meat. Traces of propranolol, ketoprofen and diclofenac were detected in some samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Residual nilpotence and residual solubility of groups

    International Nuclear Information System (INIS)

    Mikhailov, R V


    The properties of the residual nilpotence and the residual solubility of groups are studied. The main objects under investigation are the class of residually nilpotent groups such that each central extension of these groups is also residually nilpotent and the class of residually soluble groups such that each Abelian extension of these groups is residually soluble. Various examples of groups not belonging to these classes are constructed by homological methods and methods of the theory of modules over group rings. Several applications of the theory under consideration are presented and problems concerning the residual nilpotence of one-relator groups are considered.

  14. Searching for stable Na-ordered phases in single-crystal samples of γ-NaxCoO2 (United States)

    Shu, G. J.; Prodi, Andrea; Chu, S. Y.; Lee, Y. S.; Sheu, H. S.; Chou, F. C.


    We report on the preparation and characterization of single-crystal γ phase NaxCoO2 with 0.25≤x≤0.84 using a nonaqueous electrochemical chronoamperemetry technique. By carefully mapping the overpotential versus x (for xfind six distinct stable phases with Na levels corresponding to xtilde 0.75, 0.71, 0.50, 0.43, 0.33, and 0.25. The composition with x≃0.55 appears to have a critical Na concentration which separates samples with different magnetic behavior as well as different Na ion diffusion mechanisms. Chemical analysis of an aged crystal reveals different Na ion diffusion mechanisms above and below xc˜0.53 , where the diffusion process above xc has a diffusion coefficient about five times larger than that below xc . The series of crystals were studied with x-ray diffraction, susceptibility, and transport measurements. The crystal with x=0.5 shows a weak ferromagnetic transition below T=27K in addition to the usual transitions at T=51 and 88K . The resistivity of the Curie-Weiss metallic Na0.71CoO2 composition has a very low residual resistivity, which attests to the high homogeneity of the crystals prepared by this improved electrochemical method. Our results on the various stable crystal compositions point to the importance of Na ion ordering across the phase diagram.

  15. Nitrogen availability of biogas residues

    Energy Technology Data Exchange (ETDEWEB)

    El-Sayed Fouda, Sara


    The objectives of this study were to characterize biogas residues either unseparated or separated into a liquid and a solid phase from the fermentation of different substrates with respect to their N and C content. In addition, short and long term effects of the application of these biogas residues on the N availability and N utilization by ryegrass was investigated. It is concluded that unseparated or liquid separated biogas residues provide N at least corresponding to their ammonium content and that after the first fertilizer application the C{sub org}:N{sub org} ratio of the biogas residues was a crucial factor for the N availability. After long term application, the organic N accumulated in the soil leads to an increased release of N.

  16. Residual stress by repair welds

    International Nuclear Information System (INIS)

    Mochizuki, Masahito; Toyoda, Masao


    Residual stress by repair welds is computed using the thermal elastic-plastic analysis with phase-transformation effect. Coupling phenomena of temperature, microstructure, and stress-strain fields are simulated in the finite-element analysis. Weld bond of a plate butt-welded joint is gouged and then deposited by weld metal in repair process. Heat source is synchronously moved with the deposition of the finite-element as the weld deposition. Microstructure is considered by using CCT diagram and the transformation behavior in the repair weld is also simulated. The effects of initial stress, heat input, and weld length on residual stress distribution are studied from the organic results of numerical analysis. Initial residual stress before repair weld has no influence on the residual stress after repair treatment near weld metal, because the initial stress near weld metal releases due to high temperature of repair weld and then stress by repair weld regenerates. Heat input has an effect for residual stress distribution, for not its magnitude but distribution zone. Weld length should be considered reducing the magnitude of residual stress in the edge of weld bead; short bead induces high tensile residual stress. (author)

  17. Enhanced conjugation of Candida rugosa lipase onto multiwalled carbon nanotubes using reverse micelles as attachment medium and application in nonaqueous biocatalysis. (United States)

    Raghavendra, Tripti; Vahora, Uzma; Shah, Amita R; Madamwar, Datta


    Three liquid phases (viz. aqueous, nonaqueous, and reverse micelles) were scrutinized as medium for attachment of the enzyme Candida rugosa lipase (CRL) onto multiwalled carbon nanotubes (CNTs). The nanotubes were functionalized to attain carboxyl and amino groups on their surfaces before enzyme conjugation. Transmission electron microscopy and Fourier transformation infrared spectroscopic studies were used for characterization of the nanotubes during the course of functionalization. High enzyme loadings associated with the functionalized CNTs were observed when reverse micelles were used as the attachment medium. In addition, high activity in terms of ester synthesis in organic solvents was also observed while using those preparations. The nanobioconjugates prepared using reverse micelles were found to be highly sturdy and exhibited appreciable operational stability of around 95 ± 3% at 20th cycle (in case of carboxylated nanotubes) and 90 ± 5% at 10th cycle (in case of aminated nanotubes) for esterification. This shows the potential application of reverse micelles as the attachment medium for surface active enzymes such as CRL onto CNTs. © 2014 American Institute of Chemical Engineers.

  18. Effects of precursor on the morphology and size of ZrO2 nanoparticles, synthesized by sol-gel method in non-aqueous medium

    Directory of Open Access Journals (Sweden)

    Mohammed Rafiq Hussain Siddiqui


    Full Text Available Pure zirconium oxide (ZrO2 nanoparticles with diameters 10-25 nm were synthesized from ZrOCl2.8H2O and Zr(SO42.H2O with benzyl alcohol as non-aqueous solvent medium using sol-gel method. Sodium lauryl sulfate was added as surfactants to control the particle size. The synthesized ZrO2 nanoparticles have a mixture of tetragonal and monoclinic structure. The XRD showed the purity of obtained ZrO2 nanoparticles with tetragonal and monoclinic phase and the crystallite size for ZrOCl2.8H2O precursor was estimated to be 18.1 nm and that from Zr(SO42.H2O was 9.7 nm. The transmission electron microscopy and scanning electron microscopic studies also shows different sizes of nanoparticles and different morphology depending on the precursor used for the synthesis of ZrO2 nanoparticles

  19. Effects of precursor on the morphology and size of ZrO{sub 2} nanoparticles, synthesized by sol-gel method in non-aqueous medium

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, Mohammed Rafiq Hussain; Al-Wassil, Abdulaziz Ibrahim; Mahfouz, Refaat Mohamad [King Saud University, Riyadh (Saudi Arabia). Department of Chemistry, College of Science; Al-Otaibi, Abdullah Mohmmed [King Abdulaziz City for Science and Technology (Saudi Arabia). The NationalProgram for Advanced Materials and Building Systems


    Pure zirconium oxide (ZrO{sub 2}) nanoparticles with diameters 10-25 nm were synthesized from ZrOCl{sub 2}.8H{sub 2}O and Zr(SO{sub 4})2.H{sub 2}O with benzyl alcohol as non-aqueous solvent medium using sol-gel method. Sodium lauryl sulfate was added as surfactants to control the particle size. The synthesized ZrO{sub 2} nanoparticles have a mixture of tetragonal and monoclinic structure. The XRD showed the purity of obtained ZrO{sub 2} nanoparticles with tetragonal and monoclinic phase and the crystallite size for ZrOCl{sub 2}.8H{sub 2}O precursor was estimated to be 18.1 nm and that from Zr(SO{sub 4})2.H{sub 2}O was 9.7 nm. The transmission electron microscopy and scanning electron microscopic studies also shows different sizes of nanoparticles and different morphology depending on the precursor used for the synthesis of ZrO{sub 2} nanoparticles. (author)

  20. Optimization and validation of a nonaqueous micellar electrokinetic chromatography method for determination of polycyclic musks in perfumes. (United States)

    Lopez-Gazpio, Josu; Garcia-Arrona, Rosa; Ostra, Miren; Millán, Esmeralda


    A nonaqueous micellar electrokinetic chromatography method was developed for determination of Tonalide®, Galaxolide®, and Traseolide® polycyclic musks (PCMs). These compounds are widely used as fragrance ingredients in cosmetics. The method was optimized by using a three variable Box-Behnken experimental design and response surface methodology. A modified chromatographic response function was defined in order to adequately weigh the terms in the response function. After optimization of experimental conditions, an electrolyte solution of 195 mM SDS and 40 mM NaH(2) PO(4) in formamide was selected for the separation of the three PCMs, and the applied voltage was fixed at 30 kV. The nonaqueous MEKC method was then checked in terms of linearity, limits of detection and quantification, repeatability, intermediate precision and accuracy, providing appropriate values (i.e. RSD values for precision never exceeding 7%, and accuracy 96-107%). Nonaqueous MEKC for determination of the selected compounds was successfully applied to the analysis of commercial perfume samples. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. A multi-residue method for determination of 70 organic micropollutants in surface waters by solid-phase extraction followed by gas chromatography coupled to tandem mass spectrometry. (United States)

    Terzopoulou, Evangelia; Voutsa, Dimitra; Kaklamanos, George


    A multi-residue method, based on gas chromatography coupled to tandem mass spectrometry (GC-MS/MS), has been developed for the determination of 70 organic micropollutants from various chemical classes (organochlorinated, organophosphorous, triazines, carbamate and urea, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, pharmaceuticals, phenols, etc.) in surface waters. A single-step SPE extraction using OASIS HLB cartridges was employed for the recovery of target micropollutants. The method has been validated according to monitoring performance criteria of the Water Framework Directive, taking into account the approved guidelines on quality assurance and quality control. The recoveries ranged from 60 to 110 %, the coefficient of variation from 0.84 to 27.4 %, and the uncertainty from 6 to 37 %. The LOD varied from 6.0 to 40 ng/L. The limits of quantification for the priority pollutants anthracene, alachlor, atrazine, benzo(a)pyrene, chlorfenvinphos, diuron, isoproturon, nonylphenol, simazine, and terbutryn fulfill the criterion of diuron, isoproturon, salicylic acid, chlorfenvinphos, 1,2-benzanthracene, pyrene, diflubenzuron, and carbaryl exhibited the highest detection frequencies.

  2. Development and validation of a solid-phase extraction method coupled to liquid chromatography with fluorescence detection for the determination of fluoroquinolone residues in powdered infant formulae. Application to the analysis of samples from the Spanish and Latin American market. (United States)

    Rodriguez, E; Moreno-Bondi, M C; Marazuela, M D


    This paper describes a new method for the effective extraction, clean-up and chromatographic analysis of residues of four fluoroquinolones (ciprofloxacin, enrofloxacin, danofloxacin and sarafloxacin) in powdered infant formulae and follow-on preparations. Samples were reconstituted following the manufacturer's recommendations and treated with trichloroacetic acid in methanol 10% (w/v) for deproteinization. Two solid-phase extraction cartridges have been evaluated for sample clean-up and preconcentration, Strata Screen A and Strata X and the later provided the best recoveries for all the analytes tested. Chromatographic analysis has been carried out using a polar endcapped column (AQUA C(18)) and fluorescence detection, with lomefloxacin (LOME) as internal standard. Method validation has been performed according to European Commission Decision 2002/657/EC criteria, in terms of linearity, recovery, precision, specificity, decision limit (CC(alpha)) and detection capability (CC(beta)). Typical recoveries ranged between 70 and 110% at levels below and above the maximum residue limits of the target analytes in bovine milk, with an excellent intralab reproducibility (RSDsmarket, using LC-MS/MS as confirmatory technique.

  3. Rapid analysis of pesticide residues in drinking water samples by dispersive solid-phase extraction based on multiwalled carbon nanotubes and pulse glow discharge ion source ion mobility spectrometry. (United States)

    Zou, Nan; Gu, Kejia; Liu, Shaowen; Hou, Yanbing; Zhang, Jialei; Xu, Xiang; Li, Xuesheng; Pan, Canping


    An analytical method based on dispersive solid-phase extraction with a multiwalled carbon nanotubes sorbent coupled with positive pulse glow discharge ion mobility spectrometry was developed for analysis of 30 pesticide residues in drinking water samples. Reduced ion mobilities and the mass-mobility correlation of 30 pesticides were measured. The pesticides were divided into five groups to verify the separation capability of pulse glow discharge in mobility spectrometry. The extraction conditions such as desorption solvent, ionic strength, conditions of adsorption and desorption, the amounts of multiwalled carbon nanotubes, and solution pH were optimized. The enrichment factors of pesticides were 5.4- to 48.7-fold (theoretical enrichment factor was 50-fold). The detection limits of pesticides were 0.01∼0.77 μg/kg. The linear range was 0.005-0.2 mg/L for pesticide standard solutions, with determination coefficients from 0.9616 to 0.9999. The method was applied for the analysis of practical and spiked drinking water samples. All results were confirmed by high-performance liquid chromatography with tandem mass spectrometry. The proposed method was proven to be a commendably rapid screening qualitative and semiquantitative technique for the analysis of pesticide residues in drinking water samples on site. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Formation of Li3O4 nano particles in the discharge products of non-aqueous lithium-oxygen batteries leads to lower charge overvoltage. (United States)

    Shi, L; Xu, A; Zhao, T S


    Density functional theory calculations are made for bulk thermodynamic properties and surface energies of Li2O2, a primary discharge product, and Li3O4, a possible byproduct in the discharge products, of the non-aqueous lithium-oxygen batteries. Results show that the standard formation Gibbs free energy of bulk Li3O4 is marginally higher than that of Li2O2, but the surface energy of Li3O4 is much lower. Low surface energy results in both lowered nucleation energy and formation Gibbs free energy in the nanometer regime, allowing the Li3O4 nano particles to nucleate ahead of Li2O2 during the discharge process and to exist stably when particle sizes are smaller than about 40 nm. The scanning transmission electron microscopy (STEM) image of Li3O4 crystals is simulated and compared with the measured STEM image of the discharge product particles. The consistency between the simulated and measured STEM images suggests that the Li3O4 phase can exist stably as a discharge product. The energy profile of the oxygen evolution reaction (OER) occurring on the most abundant surfaces of Li3O4 is also calculated. The predicted overpotential for the OER on the {0001} surface (0.30 V) shows a good agreement with experimental data. The presence of more electronically conductive Li3O4 nano particles in the primary discharge product Li2O2 tends to decrease the charge overvoltage of the batteries, explaining why the lower voltage area (<3.5 V) was widely observed during the charging of the batteries. An increase in the oxygen pressure or a decrease in temperature enhances the stability of the Li3O4 phase and increase the proportion of the Li3O4 phase in the discharge products, consequently leading to a lower overall charge overvoltage.

  5. Methodology for the determination of residues of organophosphorous pesticides in milk of domestic consumption by means of gas chromatography and extraction in solid phase

    International Nuclear Information System (INIS)

    Romero Blanco, Eric; Meza Nunez, Humberto; Poveda Calvo, Vanessa


    A new method oriented to the detection and quantification of 15 organophosphate pesticide in raw milk samples for national consumption has been developed by using a gas chromatograph equipped with polydimethylsiloxane capillary column and a nitrogen-phosphorus detector (NPD), in combination with the extraction technique in solid phase (SPE) for the sample cleaning process and pesticide extraction. Recovery percentages obtained were close to 100% and the detection limits obtained were lower than 20 μg/L for 13 of the organophosphates analyzed. Overall, the method showed important improvement as compared to conventional liquid/liquid extraction methodologies. (Author) [es

  6. Hollow fiber liquid-phase microextraction as clean-up step for the determination of organophosphorus pesticides residues in fish tissue by gas chromatography coupled with mass spectrometry. (United States)

    Sun, Xiaojin; Zhu, Fang; Xi, Jiabin; Lu, Tongbu; Liu, Hong; Tong, Yexiang; Ouyang, Gangfeng


    Hollow fiber liquid-phase microextraction (HF-LPME) technique was used as a clean-up procedure for the determination of organophosphorus pesticides (OPPs) in fish tissue. In this study, eight OPPs were first extracted with acetone from fish sample, the organic extract after rotatory evaporation was then redissolved with water-methanol (95:5, v/v) solution, followed by polyvinylidene difluoride (PVDF) HF-LPME. Experimental HF-LPME and other sample preparation conditions were carefully investigated and optimized. Under the optimum conditions, good linearity were observed in the range of 20-500 ng/g, limits of detections (LODs) were in the range of 2.1-4.5 ng/g. The repeatability and recovery of the method also showed satisfactory results. Compared with traditional sample preparation method for the determination of OPPs in fish tissue, the method developed in this study eliminated the solid phase extraction (SPE) step, simplified the sample preparation procedure and lowered the cost of analysis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Functionalization of carbon nanotubes with magnetic nanoparticles: general nonaqueous synthesis and magnetic properties

    International Nuclear Information System (INIS)

    Zhang Hui; Du Ning; Wu Ping; Chen Bingdi; Yang Deren


    A novel approach has been developed to synthesize magnetic nanoparticle and carbon nanotube (CNT) core-shell nanostructures, such as CoO/CNTs and Mn 3 O 4 /CNTs, by the nonaqueous solvothermal treatment of metal carbonyl on CNT templates using hexane as the solvent. The morphological and structural characterizations indicate that numerous cubic CoO or tetragonal Mn 3 O 4 nanoparticles are deposited on the surfaces of the CNTs to form CNT-based core-shell nanostructures. It is revealed that the hydrophobic interaction between nanoparticles and CNTs in hexane plays the critical role for the formation of CNT-based core-shell nanostructures. A physical property measurement system (PPMS-9, Quantum Design) analysis indicates that the CoO/CNT core-shell nanostructures show weak ferromagnetic performance at 300 K due to the ferromagnetic Co clusters and the uncompensated surface spin states, while the Mn 3 O 4 /CNT core-shell nanostructures display ferromagnetic behavior at low temperature (34.5 K), which transforms into paramagnetic behavior with increasing temperature

  8. Isolation of whiskers from natural sources and their dispersed in a non-aqueous medium

    Energy Technology Data Exchange (ETDEWEB)

    Vestena, Mauro; Gross, Idejan Padilha; Pires, Alfredo Tiburcio Nunes; Muller, Carmen Maria Olivera, E-mail: [Universidade Federal Santa Catarina (UFSC), Florianopolis, SC (Brazil)


    Whiskers have been used as a nano material dispersed in polymer matrices to modify the microscopic and macroscopic properties of the polymer. These nanomaterials can be isolated from cellulose, one of the most abundant natural renewable sources of biodegradable polymer. In this study, whiskers were isolated from sugarcane bagasse and corn cob straw fibers. Initially, the cellulose fiber was treated through an alkaline/oxidative process followed by acid hydrolysis. Dimethylformamide and dimethyl sulfoxide were used to replace the aqueous medium for the dispersion of the whiskers. For the solvent exchange, dimethylformamide or dimethyl sulfoxide was added to the aqueous dispersion and the water was then removed by fractional distillation. FTIR, TGA, XRD, TEM, Zeta and DLS techniques were used to evaluate the efficiency of the isolation process as well as the morphology and dimensions of the whiskers. The dimensions of the whiskers are comparable with values reported in the literature, maintaining the uniformity and homogeneity in both aqueous and non-aqueous solvents. (author)

  9. Highly Quantitative Electrochemical Characterization of Non-Aqueous Electrolytes & Solid Electrolyte Interphases

    Energy Technology Data Exchange (ETDEWEB)

    Sergiy V. Sazhin; Kevin L. Gering; Mason K. Harrup; Harry W. Rollins


    The methods to measure solid electrolyte interphase (SEI) electrochemical properties and SEI formation capability of non-aqueous electrolyte solutions are not adequately addressed in the literature. And yet, there is a strong demand in new electrolyte generations that promote stabilized SEIs and have an influence to resolve safety, calendar life and other limitations of Li-ion batteries. To fill this gap, in situ electrochemical approach with new descriptive criteria for highly quantitative characterization of SEI and electrolytes is proposed. These criteria are: SEI formation capacity, SEI corrosion rate, SEI maintenance rate, and SEI kinetic stability. These criteria are associated with battery parameters like irreversible capacity, self-discharge, shelf-life, power, etc. Therefore, they are especially useful for electrolyte development and standard fast screening, allowing a skillful approach to narrow down the search for the best electrolyte. The characterization protocol also allows retrieving information on interfacial resistance for SEI layers and the electrochemical window of electrolytes, the other important metrics of characterization. The method validation was done on electrolyte blends containing phosphazenes, developed at Idaho National Laboratory, as 1.2M LiPF6 [80 % EC-MEC (2:8) (v/v) + 20% Phosphazene variety] (v/v), which were targeted for safer electrolyte variations.

  10. Nanoscale carbon materials from hydrocarbons pyrolysis: Structure, chemical behavior, utilisation for non-aqueous supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Savilov, Serguei V., E-mail: [Lomonosov Moscow State University, Chemistry Department (Russian Federation); Strokova, Natalia E.; Ivanov, Anton S.; Arkhipova, Ekaterina A. [Lomonosov Moscow State University, Chemistry Department (Russian Federation); Desyatov, Andrey V. [D. Mendeleyev University of Chemical Technology of Russia (Russian Federation); Hui, Xia [Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology (China); Aldoshin, Serguei M. [Lomonosov Moscow State University, Faculty of Fundamental Physical and Chemical Engineering (Russian Federation); Lunin, Valery V. [Lomonosov Moscow State University, Chemistry Department (Russian Federation)


    Highlights: • N-doped and regular carbon nanomaterials were obtained by pyrolitic technique. • Dynamic vapor sorption of different solvents reveals smaller S{sub BET} values. • Steric hindrance and specific chemical interactions are the reasons for this. • Nitrogen doping leads to raise of capacitance and coulombic efficiency with non-aqueous N-containing electrolyte. - Abstract: This work systematically studies adsorption properties of carbon nanomaterials that are synthesized through hydrocarbons that is a powerful technique to fabricate different kinds of carbon materials, e.g., nanotubes, nanoshells, onions, including nitrogen substituted. The adsorption properties of the as-synthesized carbons are achieved by low temperature nitrogen adsorption and organic vapors sorption. Heptane, acetonitrile, water, ethanol, benzene and 1-methylimidazole, which are of great importance for development of supercapacitors, are used as substrates. It is discovered that while nitrogen adsorption reveals a high specific surface area, this parameter for most of organic compounds is rather small depending not only on the size of its molecule but also on chemical interactions for a pair adsorbent–adsorbate. The experimental values of heat of adsorption for carbon and N-substituted structures, when Coulomb cross-coupling of nitrogen atoms in adsorbent and adsorbate takes place, confirms this supposition.

  11. Enrichment of 13C by chemical exchange between CO2 and amine carbamate in nonaqueous solvent

    International Nuclear Information System (INIS)

    Raica, Paula; Axente, D.


    Full text: Enrichment of 13 C by chemical exchange between CO 2 and amine carbamate in nonaqueous solvent has been mathematically modelled in two ways. The height equivalent to a theoretical plate and steady-state separation, based on the two models, have been obtained. If only the isotopic exchange between CO 2 gas and amine carbamate is considered, the model can estimate the process performance for pressures close to the atmospheric one and room temperature. For process analysis at pressures higher than atmospheric one and lower temperatures, a two-step model has been developed. Using the two models the effects of pressure increasing have been studied. At atmospheric pressure and 2M DNBA - methanol solution the isotope transfer rate is lower at 5 deg. C than at 25 deg. C. The isotope transfer is supported by pressure increasing according the increase of the CO 2 concentration in the amine solution. A lower temperature determines also an increase in the concentration of dissolved CO 2 and, for this reason, at 5 deg.C and higher pressures the isotope exchange reaction rate is higher than at 25 deg. C, HETP being lower with more than 100% at 5 deg. C than at 25 deg. C. (authors)

  12. Reaction of nonaqueous halogen solutions with YBa2Cu3O(7-x) (United States)

    Vasquez, R. P.; Foote, M. C.; Hunt, B. D.


    The reaction of the surfaces of the new high-temperature superconductor YBa2Cu3O(7-x) with nonaqueous halogen solutions is investigated, and the species formed in the reactions are identified. Treatment of films with HF/EtOH (EtOH = HI in absolute ethanol) results in the formation of an oxyfluoride with Y:Ba:Cu relative concentrations of 1:4:3. Results of X-ray photoelectron spectroscopy of HF-treated films are consistent with the formation of CuF, a compound which does not exist in bulk form. Treatment of films with HCl/EtOH results primarily in the formation of BaCl2, with smaller amounts of YCl3, CuCl, and CuCl2. Treatment with Br2/EtOH or HBr/EtOH results in the formation of YBr3, BaBr2, and CuBr with relative concentrations of 1:4:3.

  13. Thermodynamic constrains for life based on non-aqueous polar solvents on free-floating planets. (United States)

    Badescu, Viorel


    Free-floating planets (FFPs) might originate either around a star or in solitary fashion. These bodies can retain molecular gases atmospheres which, upon cooling, have basal pressures of tens of bars or more. Pressure-induced opacity of these gases prevents such a body from eliminating its internal radioactive heat and its surface temperature can exceed for a long term the melting temperature of a life-supporting solvent. In this paper two non-aqueous but still polar solvents are considered: hydrogen sulfide and ammonia. Thermodynamic requirements to be fulfilled by a hypothetic gas constituent of a life-supporting FFP's atmosphere are studied. The three gases analyzed here (nitrogen, methane and ethane) are candidates. We show that bodies with ammonia oceans are possible in interstellar space. This may happen on FFPs of (significantly) smaller or larger mass than the Earth. Generally, in case of FFP smaller in size than the Earth, the atmosphere exhibits a convective layer near the surface and a radiative layer at higher altitudes while the atmosphere of FFPs larger in size than Earth does not exhibit a convective layer. The atmosphere mass of a life-hosting FFP of Earth size is two or three orders of magnitude larger than the mass of Earth atmosphere. For FFPs larger than the Earth and specific values of surface pressure and temperature, there are conditions for condensation (in the ethane atmosphere). Some arguments induce the conclusion than the associated surface pressures and temperatures should be treated with caution as appropriate life conditions.

  14. Isolation of whiskers from natural sources and their dispersed in a non-aqueous medium

    Directory of Open Access Journals (Sweden)

    Mauro Vestena

    Full Text Available Abstract Whiskers have been used as a nanomaterial dispersed in polymer matrices to modify the microscopic and macroscopic properties of the polymer. These nanomaterials can be isolated from cellulose, one of the most abundant natural renewable sources of biodegradable polymer. In this study, whiskers were isolated from sugarcane bagasse and corn cob straw fibers. Initially, the cellulose fiber was treated through an alkaline/oxidative process followed by acid hydrolysis. Dimethylformamide and dimethyl sulfoxide were used to replace the aqueous medium for the dispersion of the whiskers. For the solvent exchange, dimethylformamide or dimethyl sulfoxide was added to the aqueous dispersion and the water was then removed by fractional distillation. FTIR, TGA, XRD, TEM, Zeta and DLS techniques were used to evaluate the efficiency of the isolation process as well as the morphology and dimensions of the whiskers. The dimensions of the whiskers are comparable with values reported in the literature, maintaining the uniformity and homogeneity in both aqueous and non-aqueous solvents.

  15. Characterization of spreadability of nonaqueous ethylcellulose gel matrices using dynamic contact angle. (United States)

    Chow, Keat Theng; Chan, Lai Wah; Heng, Paul W S


    This study reports the characterization of spreadability of nonaqueous ethylcellulose (EC) gel matrices intended for topical drug delivery using a newly developed method based on dynamic contact angle. EC solutions were prepared using three grades of EC and propylene glycol dicaprylate/dicaprate. Dynamic contact angles of sessile drops of EC solutions on silicone elastomer were measured using a dynamic contact angle analyzer equipped with axisymmetric drop shape analysis-profile. Roughness of silicone elastomer, viscosity of EC solutions and compressibility of semisolid EC gels were determined by the atomic force microscope, cone-and-plate rheometer and tensile tester, respectively. The silicone elastomer employed as a substrate was demonstrated to have similar hydrophilic/lipophilic properties as the human skin. Spreadability of EC solutions was dependent on EC concentration, polymeric chain length and polydispersity. EC gel spreadability was governed by viscosity and the extent of gel-substrate interaction. From the apparent contact angle values, most EC gel formulations tested were found to be moderately spreadable. Linear correlation observed between spreading parameter and compressibility of EC gel verified the applicability of dynamic contact angle to characterize EC gel spreadability. Thus, the feasibility of employing dynamic contact angle as an alternative technique to measure gel spreadability was demonstrated. The spreadability demonstrated by EC gel would facilitate application on the skin indicating its potential usefulness as a topical dosage form.

  16. Effects of encapsulated nitrate on growth performance, carcass characteristics, nitrate residues in tissues, and enteric methane emissions in beef steers: Finishing phase. (United States)

    Lee, C; Araujo, R C; Koenig, K M; Beauchemin, K A


    A finishing feedlot study was conducted with beef steers to determine effects of encapsulated nitrate (EN) on growth performance, carcass characteristics, methane production, and nitrate (NO) residues in tissues. The 132 crossbred steers were backgrounded in a feedlot for 91 d and transitioned for 28 days to the high-concentrate diets evaluated in the present study, maintaining the treatment and pen assignments designated at the start of the backgrounding period. The steers were initially assigned to 22 pens (6 animals per pen) in a randomized complete block design with BW (18 pens) and animals designated for methane measurement (4 pens) as blocking factors. Five animals in each pen designated for methane measurement (total of 20 animals) were monitored for methane emissions in respiratory chambers twice during the experiment. Pens received 3 dietary treatments (7 pens each): Control, a finishing diet supplemented with urea; 1.25% EN, control diet supplemented with 1.25% encapsulated NO in dietary DM that partially replaced urea; and 2.5% EN, control diet supplemented with 2.5% EN (DM basis) fully replacing urea. The final pen designated only for methane measurement received a fourth dietary treatment, 2.3% UEN, the control diet supplemented with unencapsulated NO (UEN) fully replacing urea. The cattle weighed 449 ± SD 32 kg at the start of the 150-d finishing period. The 2.5% EN diet decreased ( methane production (g/d) and yield (g/kg DMI) were observed among treatments. Inclusion of EN in the diets increased ( ≤ 0.03) sorting in favor of large and medium particles and against small and fine particles. Plasma NO and NO concentrations were elevated ( < 0.01) with EN in a dose-response manner, but total blood methemoglobin levels for all treatments were low, below the detection limit. Feeding EN increased ( < 0.01) NO concentrations of samples from muscle, fat, liver, and kidney; NO concentrations of these tissues were similar between 1.25% EN and 2.3% UEN. In

  17. The distribution, solid-phase speciation, and desorption/dissolution of As in waste iron-based drinking water treatment residuals. (United States)

    Impellitteri, Christopher A; Scheckel, Kirk G


    Arsenic concentrations and solid-phase speciation were assessed as a function of depth through Fe-media beds for two commercially available products (Granular Ferric Hydroxide-GFH and Bayoxide E33-E33) from pilot-scale water treatment field tests. These results were compared with data from solution (de-ionized water-DI-H2O) concentrations of As equilibrated with Fe-media in an anoxic environment at 4 degrees C. The materials had a high capacity for As (GFH media 9620 mg kg(-1) As, E33 Media 5246 mg kg(-1)). Arsenic concentrations decreased with bed depth. For E33, X-ray absorption near-edge spectroscopy results showed that As(V) was the dominant solid-phase species. For GFH, As(III) was detected and the proportion (relative to As(V)) of As(III) increased with bed depth. Arsenic concentrations in DI-H2O equilibrated with the media were low (35 microg l(-1)) over a period of 50 d. Arsenic concentrations in the equilibrated solutions also decreased with depth. Results from tests on soluble As speciation show that As in solution is in the form of As(V). Kinetic desorption experiments carried out at different pH values (3, 5, 7, 8, and 9) show that the media exhibit some acid/base neutralization capacity and tend to bind As sufficiently. Concentrations of As in the pH desorption experiments were in the same order of magnitude as the toxicity characteristic leaching procedure extractions (tens of microgl(-1)) except at low pH values. For the GFH media tested at a pH of three, As increases in solution and is mainly associated with colloidal (operationally defined as between 0.1 and 1.0 microm) iron.

  18. Trace determination of five triazole fungicide residues in traditional Chinese medicine samples by dispersive solid-phase extraction combined with ultrasound-assisted dispersive liquid-liquid microextraction and UHPLC-MS/MS. (United States)

    Ma, Shuping; Yuan, Xucan; Zhao, Pengfei; Sun, Hong; Ye, Xiu; Liang, Ning; Zhao, Longshan


    A novel and reliable method for determination of five triazole fungicide residues (triadimenol, tebuconazole, diniconazole, flutriafol, and hexaconazol) in traditional Chinese medicine samples was developed using dispersive solid-phase extraction combined with ultrasound-assisted dispersive liquid-liquid microextraction before ultra-high performance liquid chromatography with tandem mass spectrometry. The clean up of the extract was conducted using dispersive solid-phase extraction by directly adding sorbents into the extraction solution, followed by shaking and centrifugation. After that, a mixture of 400 μL trichloromethane (extraction solvent) and 0.5 mL of the above supernatant was injected rapidly into water for the dispersive liquid-liquid microextraction procedure. The factors affecting the extraction efficiency were optimized. Under the optimum conditions, the calibration curves showed good linearity in the range of 2.0-400 (tebuconazole, diniconazole, and hexaconazole) and 4.0-800 ng/g (triadimenol and flutriafol) with the regression coefficients higher than 0.9958. The limit of detection and limit of quantification for the present method were 0.5-1.1 and 1.8-4.0 ng/g, respectively. The recoveries of the target analytes ranged from 80.2 to 103.2%. The proposed method has been successfully applied to the analysis of five triazole fungicides in traditional Chinese medicine samples, and satisfactory results were obtained. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Sol-gel-graphene-based fabric-phase sorptive extraction for cow and human breast milk sample cleanup for screening bisphenol A and residual dental restorative material before analysis by HPLC with diode array detection. (United States)

    Samanidou, Victoria; Filippou, Olga; Marinou, Eirini; Kabir, Abuzar; Furton, Kenneth G


    Fabric-phase sorptive extraction has already been recognized as a simple and green alternative to the conventional sorbent-based sorptive microextraction techniques, using hybrid organic-inorganic sorbent coatings chemically bonded to a flexible fabric surface. Herein, we have investigated the synergistic combination of the advanced material properties offered by sol-gel graphene sorbent and the simplicity of Fabric phase sorptive extraction approach in selectively extracting bisphenol A and residual monomers including bisphenol A glycerolatedimethacrylate, urethane dimethacrylate, and triethylene glycol dimethacrylate derived dental restorative materials from cow and human breast milk samples. Different coatings were evaluated. Final method development employed sol-gel graphene coated media. The main experimental parameters influencing extraction of the compounds, such as sorbent chemistry used, sample loading conditions, elution solvent, sorption stirring time, elution time, impact of protein precipitation, amount of sample, and matrix effect, were investigated and optimized. Absolute recovery values from standard solutions were 50% for bisphenol A, 78% for T triethylene glycol dimethacrylate, 110% for urethane dimethacrylate, and 103% for bisphenol A glycerolatedimethacrylate, while respective absolute recovery values from milk were 30, 52, 104, and 42%. Method validation was performed according to European Decision 657/2002/EC in terms of selectivity, sensitivity, linearity, accuracy, and precision. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Deep eutectic solvent based gas-assisted dispersive liquid-phase microextraction combined with gas chromatography and flame ionization detection for the determination of some pesticide residues in fruit and vegetable samples. (United States)

    Farajzadeh, Mir Ali; Sattari Dabbagh, Masoumeh; Yadeghari, Adeleh


    In this study, a gas-assisted dispersive liquid-phase microextraction method using a deep eutectic solvent as the extraction solvent combined with gas chromatography and flame ionization detection was developed for the extraction and determination of some pesticide residues in vegetable and fruit juice samples. In this method, choline chloride and 4-chlorophenol at a molar ratio of 1:2 were mixed. By heating and vortexing, a clear, water-immiscible, and homogeneous liquid was formed. The obtained deep eutectic solvent was added to an aqueous solution of the analytes in a conical test tube. Air was bubbled into the aqueous solution and a cloudy solution was obtained. During this step, the analytes were extracted into the fine droplets of the extraction solvent. After centrifugation, an aliquot of the settled phase was injected into the separation system. Under the optimum extraction conditions, enrichment factors, and extraction recoveries were obtained in the ranges of 247-355 and 49-71%, respectively. The obtained values for the limits of detection and quantification were in the ranges of 0.24-1.4 and 0.71-4.2 μg/L, respectively. The proposed method is simple, fast, efficient, and inexpensive. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Optimization of dispersive liquid-phase microextraction based on solidified floating organic drop combined with high-performance liquid chromatography for the analysis of glucocorticoid residues in food. (United States)

    Huang, Yuan; Zheng, Zhiqun; Huang, Liying; Yao, Hong; Wu, Xiao Shan; Li, Shaoguang; Lin, Dandan


    A rapid, simple, cost-effective dispersive liquid-phase microextraction based on solidified floating organic drop (SFOD-LPME) was developed in this study. Along with high-performance liquid chromatography, we used the developed approach to determine and enrich trace amounts of four glucocorticoids, namely, prednisone, betamethasone, dexamethasone, and cortisone acetate, in animal-derived food. We also investigated and optimized several important parameters that influenced the extraction efficiency of SFOD-LPME. These parameters include the extractant species, volumes of extraction and dispersant solvents, sodium chloride addition, sample pH, extraction time and temperature, and stirring rate. Under optimum experimental conditions, the calibration graph exhibited linearity over the range of 1.2-200.0ng/ml for the four analytes, with a reasonable linearity(r 2 : 0.9990-0.9999). The enrichment factor was 142-276, and the detection limits was 0.39-0.46ng/ml (0.078-0.23μg/kg). This method was successfully applied to analyze actual food samples, and good spiked recoveries of over 81.5%-114.3% were obtained. Copyright © 2017. Published by Elsevier B.V.

  2. Use of Interface Treatment to Reduce Emissions from Residuals in Lower Permeability Zones to Groundwater flowing Through More Permeable Zones (Invited) (United States)

    Johnson, P.; Cavanagh, B.; Clifton, L.; Daniels, E.; Dahlen, P.


    Many soil and groundwater remediation technologies rely on fluid flow for contaminant extraction or reactant delivery (e.g., soil vapor extraction, pump and treat, in situ chemical oxidation, air sparging, enhanced bioremediation). Given that most unconsolidated and consolidated settings have permeability contrasts, the outcome is often preferential treatment of more permeable zones and ineffective treatment of the lower permeability zones. When this happens, post-treatment contaminant emissions from low permeability zone residuals can cause unacceptable long-term impacts to groundwater in the transmissive zones. As complete remediation of the impacted lower permeability zones may not be practicable with conventional technologies, one might explore options that lead to reduction of the contaminant emissions to acceptable levels, rather than full remediation of the lower permeability layers. This could be accomplished either by creating a sustained emission reaction/attenuation zone at the high-low permeability interface, or by creating a clean soil zone extending sufficiently far into the lower permeability layer to cause the necessary reduction in contaminant concentration gradient and diffusive emission. These options are explored in proof-of-concept laboratory-scale physical model experiments. The physical models are prepared with two layers of contrasting permeability and either dissolved matrix storage or nonaqueous phase liquid (NAPL) in the lower permeability layer. A dissolved oxidant is then delivered to the interface via flow across the higher permeability layer and changes in contaminant emissions from the low permeability zone are monitored before, during, and after oxidant delivery. The use of three oxidants (dissolved oxygen, hydrogen peroxide and sodium persulfate) for treatment of emissions from petroleum hydrocarbon residuals is examined.

  3. Magnetic solid phase extraction based on magnetite/reduced graphene oxide nanoparticles for determination of trace isocarbophos residues in different matrices. (United States)

    Yan, Shan; Qi, Ting-Ting; Chen, De-Wen; Li, Zhao; Li, Xiu-Juan; Pan, Si-Yi


    A simple one-step solvothermal method was applied for the preparation of magnetite/reduced graphene oxide (MRGO), and the synthetic nanocomposites with a magnetic particle size of ∼8nm were used as an adsorbent for magnetic solid phase extraction of isocarbophos (ICP) in different sample matrices prior to gas chromatography (GC) detection. The identity of the nanomaterial was confirmed using Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. It was shown that Fe3O4 nanoparticles with a uniform size were homogeneously anchored on RGO nanosheets. Increased oxidation degrees of graphite oxide, big particle sizes and large loading amounts of Fe3O4 on the surface of RGO led to a decrease of adsorption capacity of MRGO to ICP. The adsorption behavior of this adsorbent was better fitted by the pseudo-second-order kinetic model. Several parameters affecting the extraction efficiency were investigated and optimized, including adsorbent dosage, extraction time, ionic strength and desorption conditions. And then, a rapid and effective method based on MRGO combined with GC was developed for the determination of ICP in aqueous samples. A linear range from 0.05 to 50ngmL(-1) was obtained with a high correlation coefficient (R(2)) of 0.9995, and the limit of detection was found to be 0.0044ngmL(-1). This method was successfully applied to the analysis of ICP in five kinds of samples, including apple, rice, lake water, cowpea and cabbage. The recoveries in different sample matrices were in the range from 81.00% to 108.51% with relative standard deviations less than 9.72%. It can be concluded that the proposed analytical method is highly-efficient, sensitive, precise, accurate and practicable. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Development of a two separate phase submerged biocatalytic membrane reactor for the production of fatty acids and glycerol from residual vegetable oil streams

    International Nuclear Information System (INIS)

    Chakraborty, S.; Drioli, E.; Giorno, L.


    Enzymatic membrane bioreactors (MBR) have been studied for very different applications since many years. Submerged MBR has also been successfully used for treatment of wastewater. In the existing submerged configuration, the membrane works as the separation unit operation while the bioconversion is carried out by microorganisms suspended in the tank reactor. In the present work, a novel approach that combines the concept of biocatalytic membranes and submerged modules is proposed for the treatment of biomass. Lipase enzyme from Candida rugosa has been immobilized in polyethersulphone hollow fiber (PES HF) membrane in order to develop a two separate phase biocatalytic submerged membrane reactor in which the membrane works as both catalytic and separation unit. Furthermore, the submerged biocatalytic membrane reactor is intended for production of valuable components from waste biomass, and different physical, chemical and fluid dynamics has been optimized. Response surface methodology (RSM) has been used to model the operating parameters and Box-Behnken method has been applied to maximize the fatty acids production and optimization. At TMP 80 ± 2 kPa, pH 7.40 ± 0.1, temperature 35 ± 0.5 °C with an axial velocity of 0.07 ± 0.01 ms −1 and organic stirring 89.01 rad s −1 the system showed the global examined value within the experimental scope. The proof of principle using fried cooked oils has been performed in later period. -- Highlights: ► Catalytic activity of enzyme in submerged condition has been studied. ► Optimization of submerged biocatalytic membrane reactor for production of value added components. ► Waste valorization by membrane reactor in order to minimization of waste. ► Three different waste oil (as waste biomass) has been studied in respect to product generation and different results obtained.

  5. Resíduo de polpas de frutas desidratadas na alimentação de leitões em fase de creche Powdered fruits pulp residue in the piglets feeding in the nursery phase

    Directory of Open Access Journals (Sweden)

    Messias Alves da Trindade Neto


    matter 96,01%, digestible energy 3448 kcal/kg, metabolizable energy 3389 kcal/kg. By bromatologic results and metabolism study, the powdered fruits pulp residue was characterized as an alternative to be evaluated in piglet diets. In the performance assay 90 piglets with initial weight of 6,60 ± 0,76 kg were allotted in a randomized block design, with six replications and three animals per experimental unit. The treatments were levels of powdered fruits pulp residue (0, 25, 50, 75 and 100% replacing the corn of the control diet. The studied phases were initial-1 (14 days, initial-2 (21 days and total period. On the performance there was no difference between the studied inclusion levels. For meal diets, the fruits pulp residue can replace the corn.

  6. On-line solid phase extraction-liquid chromatography-tandem mass spectrometry for insect repellent residue analysis in surface waters using atmospheric pressure photoionization. (United States)

    Molins-Delgado, Daniel; García-Sillero, Daniel; Díaz-Cruz, M Silvia; Barceló, Damià


    Insect repellents (IRs) are a group of organic chemicals whose function is to prevent the ability of insects of landing in a surface. These compounds have been found in the environment and may pose a risk to non-target organisms. In this study, an on-line solid phase extraction - high performance liquid chromatography-tandem mass spectrometry multiresidue method was developed using an atmospheric photoionization source (SPE-HPLC-(APPI)-MS/MS). The use of the APPI as an alternative ionization technique to electrospray (ESI) and atmospheric pressure chemical ionization (APCI) allowed expanding the range of analytical techniques suitable for the analysis of IRs, so far relied in gas chromatography. High sensitivity and precision was reached with method limits of quantification between 0.2 and 4.6 ng l -1 and interday and intraday precision equal or below 15%. The validated method was applied to the study of surface water samples from three European river basins with different flow regime (Adige River in Italy, Sava River in the Balkans, and Evrotas River in Greece). The results showed that two IRs (DEET and Bayrepel) were ubiquitous in the Sava and Evrotas basins, reaching concentrations as high as 105 μg l -1 of Bayrepel in the Sava River, and 5 μg l -1 of DEET in the Evrotas River. Densely populated areas and effluent waste waters are pointed out as the responsible for this pollution. In the alpine river Adige, only three samples showed low levels of IRs (6.01-37.8 ng l -1 ). The concentrations measured were used to perform an environmental risk assessment based on the hazard quotients (HQs) estimation approach by using the chronic and acute eco-toxicity data available. The results revealed that despite the high frequency and eventually high concentrations of these IRs determined in the three basins, only few sites were at risk, with 1 < HQs < 3.3. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

  7. Fe3O4/hydroxyapatite/graphene quantum dots as a novel nano-sorbent for preconcentration of copper residue in Thai food ingredients: Optimization of ultrasound-assisted magnetic solid phase extraction. (United States)

    Sricharoen, Phitchan; Limchoowong, Nunticha; Areerob, Yonrapach; Nuengmatcha, Prawit; Techawongstien, Suchila; Chanthai, Saksit


    Fe 3 O 4 /hydroxyapatite/graphene quantum dots (Fe 3 O 4 /HAP/GQDs) nanocomposite was synthesized and used as a novel magnetic adsorbent. This nanocomposite was characterized using scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, and magnetization property. The Fe 3 O 4 /HAP/GQDs was applied to pre-concentrate copper residues in Thai food ingredients (so-called "Tom Yum Kung") prior to determination by inductively coupled plasma-atomic emission spectrometry. Based on ultrasound-assisted extraction optimization, various parameters affecting the magnetic solid-phase extraction, such as solution pH, amount of magnetic nanoparticles, adsorption and desorption time, and type of elution solvent and its concentration were evaluated. Under optimal conditions, the linear range was 0.05-1500ngmL -1 (R 2 >0.999), limit of detection was 0.58ngmL -1 , and limit of quantification was 1.94ngmL -1 . The precision, expressed as the relative standard deviation of the calibration curve slope (n=5), for intra-day and inter-day analyses was 0.87% and 4.47%, respectively. The recovery study of Cu for real samples was ranged between 83.5% and 104.8%. This approach gave the enrichment factor of 39.2, which guarantees trace analysis of Cu residues. Therefore, Fe 3 O 4 /HAP/GQDs can be a potential and suitable candidate for the pre-concentration and separation of Cu from food samples. It can easily be reused after treatment with deionized water. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Electrodeposition of tantalum on carbon black in non-aqueous solution and its electrocatalytic properties

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Ara; Lee, Youngmi, E-mail:; Lee, Chongmok, E-mail:


    In this work, we synthesized tantalum (Ta) nanoclusters on carbon black (Ta/CB) via simple electrodeposition in non-aqueous solvent, acetonitrile (ACN) at ambient temperature. Transmission electron microscopy (TEM) images showed that the electrodeposited Ta nanoclusters consisted of tiny Ta nanoparticles. X-ray photoelectron spectroscopy (XPS) result represented that the outermost Ta formed the native oxide on Ta/CB due to its ambient exposure to air. Electrochemical catalytic properties of prepared Ta/CB on glassy carbon electrode (Ta/CB/GC) were investigated toward reductions of oxygen and hydrogen peroxide, and oxidations of ascorbic acid and dopamine. For oxygen reduction reaction (ORR) in acid, Ta/CB/GC represented a decent electrocatalytic performance which was better or comparable to bare Pt. The operational stability in acidic condition was maintained up to 500 repetitive potential cycles presumably due to the protective native Ta oxide layer. Ta/CB/GC also showed high amperometric sensitivity (4.5 (±0.1{sub 6}) mA mM{sup −1} cm{sup −2}, n = 5) for reduction of hydrogen peroxide in 0.1 M phosphate buffer solution (PBS, pH 7.4). In addition, Ta/CB/GC was demonstrated for the possibility of simultaneous detection of ascorbic acid and dopamine using differential pulse voltammetry (DPV). - Highlights: • We electrodeposited Ta nanoclusters (Ta/CB/GC) in acetonitrile at room temperature. • The Ta/CB/GC showed better or comparable performance to bare Pt for ORR. • The Ta/CB/GC showed high sensitivity for reduction of hydrogen peroxide at pH 7.4. • The Ta/CB/GC showed possible simultaneous detection of ascorbic acid and dopamine. • We extended the applicability of Ta electrode material for various electrocatalytic reactions.

  9. High-Performance Oligomeric Catholytes for Effective Macromolecular Separation in Nonaqueous Redox Flow Batteries (United States)


    Nonaqueous redox flow batteries (NRFBs) represent an attractive technology for energy storage from intermittent renewable sources. In these batteries, electrical energy is stored in and extracted from electrolyte solutions of redox-active molecules (termed catholytes and anolytes) that are passed through an electrochemical flow cell. To avoid battery self-discharge, the anolyte and catholyte solutions must be separated by a membrane in the flow cell. This membrane prevents crossover of the redox active molecules, while simultaneously allowing facile transport of charge-balancing ions. A key unmet challenge for the field is the design of redox-active molecule/membrane pairs that enable effective electrolyte separation while maintaining optimal battery properties. Herein, we demonstrate the development of oligomeric catholytes based on tris(dialkylamino)cyclopropenium (CP) salts that are specifically tailored for pairing with size-exclusion membranes composed of polymers of intrinsic microporosity (PIMs). Systematic studies were conducted to evaluate the impact of oligomer size/structure on properties that are crucial for flow battery performance, including cycling stability, charge capacity, solubility, electron transfer kinetics, and crossover rates. These studies have led to the identification of a CP-derived tetramer in which these properties are all comparable, or significantly improved, relative to the monomeric counterpart. Finally, a proof-of-concept flow battery is demonstrated by pairing this tetrameric catholyte with a PIM membrane. After 6 days of cycling, no crossover is detected, demonstrating the promise of this approach. These studies provide a template for the future design of other redox-active oligomers for this application. PMID:29532018

  10. Lithium ion quantification using mercury amalgams as in situ electrochemical probes in nonaqueous media. (United States)

    Barton, Zachary J; Rodríguez-López, Joaquín


    We report on the quantitative, spatially resolved study of ionic processes for energy materials in nonaqueous environments by in situ electrochemical means at the micro- and nanoscale. Mercury-capped platinum ultramicroelectrodes (Hg/Pt UMEs) were tested as probes for alkali ions in propylene carbonate (PC) in an oxygen- and water-free environment. Anodic stripping voltammetry (ASV) performed at Hg/Pt UMEs displayed a linear response to Li(+) concentration extending from 20 μM to at least 5 mM. The sensitivities of these probes for ionic lithium are 1.93 and -23.2 pA μM(-1) by the steady-state amalgamation current and the peak stripping current, respectively. These values showed excellent agreement with simulated results as well as to those obtained experimentally for Cd(2+) in H2O. We further explored the interfacial imaging of lithium ion flux at an electrified interface. Scanning electrochemical microscopy (SECM) using Hg/Pt UMEs showed that the steady-state amalgamation of ionic lithium could be used to reliably position a probe close to a substrate. Investigations on a selectively insulated gold electrode in an organic solvent system showcased the response of Hg/Pt UMEs to lithium uptake by an electroactive material. Additionally, lithium stripping voltammetry at Hg deposits on a 120 nm carbon nanoelectrode demonstrated the possibility of implementing the introduced imaging strategy at the nanoscale. This work opens a way to directly correlate material defects and reactive heterogeneity in energy materials with unprecedented spatial and temporal resolution.

  11. Polyfluorinated boron cluster based salts: A new electrolyte for application in nonaqueous asymmetric AC/Li{sub 4}Ti{sub 5}O{sub 12} supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Ionica-Bousquet, C.M.; Munoz-Rojas, D.; Palacin, M.R. [Institut de Ciencia de Materials de Barcelona, CSIC, Campus UAB, E-08193 Bellaterra (Spain); Casteel, W.J. Jr.; Pearlstein, R.M.; Kumar, G. Girish; Pez, G.P. [Air Products and Chemicals, Inc., 7201 Hamilton Blvd., Allentown, PA 18195 (United States)


    Solutions of novel fluorinated lithium dodecaborate (Li{sub 2}B{sub 12}F{sub x}H{sub 12-x}) salts have been evaluated as electrolytes in nonaqueous asymmetric supercapacitors with Li{sub 4}Ti{sub 5}O{sub 12} as negative electrode, and activated carbon (AC) as positive electrode. The results obtained with these new electrolytes were compared with those obtained with cells built using standard 1 M LiPF{sub 6} dissolved in ethylene carbonate and dimethyl carbonate (EC:DMC; 1:1, v/v) as electrolyte. The specific energy, rate capability, and cycling performances of nonaqueous asymmetric cells based on these new electrolyte salts were studied. Cells assembled using the new fluoroborate salts show excellent reversibility, coulombic efficiency, rate capability and improved cyclability when compared with the standard electrolyte. These features confirm the suitability of lithium-fluoro-borate based salts to be used in nonaqueous asymmetric supercapacitors. (author)

  12. Communication: The influence of CO2 poisoning on overvoltages and discharge capacity in non-aqueous Li-Air batteries

    DEFF Research Database (Denmark)

    Mekonnen, Yedilfana Setarge; Knudsen, Kristian Bastholm; Mýrdal, Jón Steinar Garðarsson


    The effects of Li2CO3 like species originating from reactions between CO2 and Li2O2 at the cathode of non-aqueous Li-air batteries were studied by density functional theory (DFT) and galvanostatic charge-discharge measurements. Adsorption energies of CO2 at various nucleation sites on a stepped (1...... the Li2O2 growth mechanism, capacity, and overvoltages. The charging processes are strongly influenced by CO2 contamination, and exhibit increased overvoltages and increased capacity, as a result of poisoning of nucleation sites: this effect is predicted from DFT calculations and observed experimentally...

  13. Multi-residue analysis of veterinary drugs, pesticides and mycotoxins in dairy products by liquid chromatography-tandem mass spectrometry using low-temperature cleanup and solid phase extraction. (United States)

    Xie, Jie; Peng, Tao; Zhu, Ailing; He, Jianli; Chang, Qiaoying; Hu, Xueyan; Chen, Hui; Fan, Chunlin; Jiang, Wenxiao; Chen, Min; Li, Jiancheng; Ding, Shuangyang; Jiang, Haiyang


    A multi-class multi-residue analysis method for determination of veterinary drugs, pesticides and mycotoxins in dairy products by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been established. These 17 classes, a total of 40 kinds of target compounds were chosen because their administration to food-producing animals is banned or regulated in China and may be potentially abused or misused. Samples were extracted with acetonitrile-ethyl acetate-acetic acid (49.5+49.5+1, v/v/v). Most of lipids in the extract were removed by low-temperature cleanup, prior to solid phase extraction on HLB cartridges. The quantification and confirmation of the 40 analytes were performed by LC-MS/MS with electro-spray ionization (ESI) interface in multiple reaction monitoring (MRM) mode. The limits of detection (LODs) and limits of quantification (LOQs) were 0.006-0.3μg/kg and 0.02-1.0μg/kg, respectively. The spiked recoveries in milk, yogurt, milk powder and cheese samples were from 67.3% to 106.9%. The repeatability and the within-laboratory reproducibility were less than 12.7% and 13.9%. Applying this method, our results revealed the presences of chloramphenicol, cimeterol, and flunixin at the concentration of 0.027-0.452μg/kg in some samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Microwave-assisted nonaqueous sol-gel deposition of different spinel ferrites and barium titanate perovskite thin films. (United States)

    Kubli, Martin; Luo, Li; Bilecka, Idalia; Niederberger, Markus


    Rapid and selective heating of solvents by microwave irradiation coupled to nonaqueous sol-gel chemistry makes it possible to simultaneously synthesize metal oxide nanoparticles within minutes and deposit them on substrates. The simple immersion of substrates, such as glass slides, in the reaction solution results after microwave heating in the deposition of homogeneous porous thin films whose thickness can be adjusted through the precursor concentration. Here we use such a microwave-assisted nonaqueous sol-gel process for the formation of various spinel ferrite MFe2O4 (M = Fe, Co, Mn, Ni) and BaTiO3 nanoparticles and their deposition as thin films. The approach offers high flexibility with respect to controlling the crystal size by adjusting the reaction time and/or temperature. Based on the example of CoFe2O4 nanoparticles, we show how the crystal size can carefully be tuned from 4 to 8 nm, resulting in a continuous change of the magnetic properties.

  15. Macromolecular Design Strategies for Preventing Active-Material Crossover in Non-Aqueous All-Organic Redox-Flow Batteries. (United States)

    Doris, Sean E; Ward, Ashleigh L; Baskin, Artem; Frischmann, Peter D; Gavvalapalli, Nagarjuna; Chénard, Etienne; Sevov, Christo S; Prendergast, David; Moore, Jeffrey S; Helms, Brett A


    Intermittent energy sources, including solar and wind, require scalable, low-cost, multi-hour energy storage solutions in order to be effectively incorporated into the grid. All-Organic non-aqueous redox-flow batteries offer a solution, but suffer from rapid capacity fade and low Coulombic efficiency due to the high permeability of redox-active species across the battery's membrane. Here we show that active-species crossover is arrested by scaling the membrane's pore size to molecular dimensions and in turn increasing the size of the active material above the membrane's pore-size exclusion limit. When oligomeric redox-active organics (RAOs) were paired with microporous polymer membranes, the rate of active-material crossover was reduced more than 9000-fold compared to traditional separators at minimal cost to ionic conductivity. This corresponds to an absolute rate of RAO crossover of less than 3 μmol cm -2  day -1 (for a 1.0 m concentration gradient), which exceeds performance targets recently set forth by the battery industry. This strategy was generalizable to both high and low-potential RAOs in a variety of non-aqueous electrolytes, highlighting the versatility of macromolecular design in implementing next-generation redox-flow batteries. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. The IUPAC aqueous and non-aqueous experimental pKa data repositories of organic acids and bases. (United States)

    Slater, Anthony Michael


    Accurate and well-curated experimental pKa data of organic acids and bases in both aqueous and non-aqueous media are invaluable in many areas of chemical research, including pharmaceutical, agrochemical, specialty chemical and property prediction research. In pharmaceutical research, pKa data are relevant in ligand design, protein binding, absorption, distribution, metabolism, elimination as well as solubility and dissolution rate. The pKa data compilations of the International Union of Pure and Applied Chemistry, originally in book form, have been carefully converted into computer-readable form, with value being added in the process, in the form of ionisation assignments and tautomer enumeration. These compilations offer a broad range of chemistry in both aqueous and non-aqueous media and the experimental conditions and original reference for all pKa determinations are supplied. The statistics for these compilations are presented and the utility of the computer-readable form of these compilations is examined in comparison to other pKa compilations. Finally, information is provided about how to access these databases.

  17. Effect of Porous Media and Fluid Properties on Dense Non-Aqueous Phase Liquid Migration and Dilution Mass Flux

    National Research Council Canada - National Science Library

    Totten, Christian T


    .... Media grain size and NAPL wettability were varied for relative comparisons. Fluid properties including density differential and interfacial tension between NAPL and water were varied for relative comparisons...

  18. Moving beyond pump-and-treat. [Treatment of groundwater contaminated by dense non-aqueous phase liquids (DNAPLs)

    Energy Technology Data Exchange (ETDEWEB)

    Hasbach, A.


    DNAPLs such as chlorinated solvents, creosotes, and PCB oils migrate downward through both the unsaturated and saturated zones of the subsurface environment. Pump-and-treat methods will not achieve complete clean-up at DNAPL sites. The EPA's Technology Innovation office has identified technologies that hold promise for either treating groundwater in place or improving the solubility of contaminants to enhance pump-and-treat. This article briefly reviews in situ treatment, pump-and-treat enhancement, and enhanced recovery technologies. The correct solution will be varied and site specific. A new technology center at the EPA's Robert S. Kerr Environmental Research Laboratory in Ada, Oklahoma will serve as a clearinghouse for both public and private research into groundwater contamination.

  19. On the kinetics between CO2 and alkanolamines both in aqueous and non-aqueous solutions—I. Primary and secondary amines

    NARCIS (Netherlands)

    Versteeg, G.F.; Swaaij, W.P.M. van


    The reaction between CO2 and primary and secondary alkanolamines (DEA and DIPA) has been studied both in aqueous and non-aqueous solutions (ethanol and n-butanol) at various temperatures. Reaction kinetics have been established by chemically enhanced mass transfer of CO2 into the various solutions.

  20. Universality in Nonaqueous Alkali Oxygen Reduction on Metal Surfaces: Implications for Li−O2 and Na−O2 Batteries

    DEFF Research Database (Denmark)

    Krishnamurthy, Dilip; Hansen, Heine Anton; Viswanathan, Venkatasubramanian


    Nonaqueous metal−oxygen batteries, particularly lithium−oxygen and sodium−oxygen, have emerged as possible high energy density alternatives to Li-ion batteries that could address the limited driving range issues faced by electric vehicles. Many fundamental questions remain unanswered, including t...

  1. Monitoring the extraction of additives and additive degradation products from polymer packaging into solutions by multi-residue method including solid phase extraction and ultra-high performance liquid chromatography-tandem mass spectrometry analysis. (United States)

    Pouech, Charlène; Lafay, Florent; Wiest, Laure; Baudot, Robert; Léonard, Didier; Cren-Olivé, Cécile


    The use of polymer materials in industry for product packaging is increasing. The presence of additives in the polymer matrix enables the modification or improvement of the properties and performance of the polymer, but these industries are concerned regarding the extractability of these additives. The quantification of these additives is particularly challenging because of the presence of these substances as contaminants in all the analytical equipment and the diversity of their physicochemical properties. In this context, a multi-residue analytical method was developed for the trace analysis of the twenty main additives (and their degradation products) authorized in plastic products such as pharmaceutical packaging (e.g., antioxidants, release agents, and light absorbers). This analytical method consisted of a solid phase extraction (SPE) followed by an analysis using ultra-high performance liquid chromatography coupled to a tandem mass spectrometer (UHPLC-MS/MS). A comparison of two ionization interfaces and the optimization of the extraction procedure were discussed. The influence of the quality of the solvent type (distilled versus not distilled) and the nature of the SPE cartridges (Polypropylene versus Teflon(®)) were demonstrated. The optimized method exhibited a quantification limit lower than 20 ng mL(-1) and recoveries between 70 % and 120 % for all compounds. Finally, the method was validated according to the ICH directive and was subsequently applied to the extraction of polymers under different pH conditions and storage temperatures. To the best of our knowledge, this study presents the first methodology allowing the simultaneous quantification of 24 additives at low ng mL(-1).

  2. Effect of weathering transformations of coal combustion residuals on trace element mobility in view of the environmental safety and sustainability of their disposal and use. I. Hydrogeochemical processes controlling pH and phase stability. (United States)

    Stefaniak, Sebastian; Miszczak, Ewa; Szczepańska-Plewa, Jadwiga; Twardowska, Irena


    Coal combustion residuals (CCRs) are one of the most abundant high-volume waste materials disposed in impoundments worldwide. Some methods of CCR recycling, e.g. their use as structural fill for low lying areas or as soil amendment, also expose this material to atmospheric conditions. Combustion processes result in concentration of trace elements in CCRs at about an order of magnitude compared to coal. In order to assess an effect of long-term weathering transformations of CCRs on trace element binding/release, a study has been carried out. It is based on the chemical composition of real pore solutions extracted from the most abundant primary alkaline Class F bituminous CCRs, 0 to >40 years old, sampled from the surface layer and vertical profiles at four different impoundments. In this part of the study, results of a hydrogeochemical simulation of the saturation state of real pore solutions with respect to mineral phases of CCRs with use of the PHREEQC program, related to actual pH values reflecting the full cycle of weathering transformations, have been discussed. This study is the first geochemical proof of the general trend towards a progressive acidification up to pH < 4 of primary alkaline CCRs due to release of protons during internal processes of formation of gibbsite and aluminosilicate minerals, buffered by carbonates at the alkaline - near-neutral stages, and followed by parallel dissolution and buffering by aluminosilicates at pH < 7 after carbonate depletion, to the level up to pH∼3.5-4.0. The intrinsic geochemical changes have resulted in the different susceptibility of trace elements to release and associated changes in risk to the environment at consecutive stages of weathering. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Investigation of the charge-transfer in photo-excited nanoparticles for CO2 reduction in non-aqueous media

    Directory of Open Access Journals (Sweden)

    Dimitrijević Nada M.


    Full Text Available Photoinduced charge separation in TiO2 and Cu2O semiconductor nanoparticles was examined using Electron Paramagnetic Resonance spectroscopy in order to get insight into the photocatalytic reduction of CO2 in nonaqueous media. For dissolution/grafting of CO2 we have used carboxy-PEG4-amine, and as a solvent poly(ethylene glycol 200. We have found that, in this system, reduction of CO2 starts at potential of -0.5 V vs Ag/AgCl, which is significantly more positive than the potential for electrochemical reduction of CO2 in most organic solvents and water (-2.0 V vs. Ag/AgCl. The electron transfer from excited nanoparticles to CO2 is governed both by thermodynamic and kinetic parameters, namely by the redox potential of conduction band electrons and adsorption/binding of CO2 on the surface of nanoparticles.

  4. Magnetic Properties and AC Losses in AFe2O4 (A = Mn, Co, Ni, Zn Nanoparticles Synthesized from Nonaqueous Solution

    Directory of Open Access Journals (Sweden)

    Oleksandr Yelenich


    Full Text Available Nanosized particles of AFe2O4 (A = Mn, Co, Ni, or Zn spinel ferrites were synthesized by coprecipitation from nonaqueous solutions using nitrate salts as starting reagents. The particles were characterized by X-ray diffraction, transmission electron microscopy, and magnetic measurements. Quasistatic magnetic measurements show superparamagnetic behavior with blocking temperature below room temperature for cobalt, nickel, and zinc spinel ferrite nanoparticles. Characteristic magnetic parameters of the particles including average magnetic moment of an individual nanoparticle and blocking temperature have been determined. The specific loss power which is released on the exposure of an ensemble of synthesized particles to a magnetic field is calculated and measured experimentally. It is shown that among all nanoferrites under study, the ZnFe2O4 nanoparticles demonstrate the highest heating efficiency in AC magnetic fields. The key parameters responsible for the heating efficiency in AC magnetic field have been determined. The directions to enhance the SLP value have been outlined.

  5. Residual gas analysis

    International Nuclear Information System (INIS)

    Berecz, I.


    Determination of the residual gas composition in vacuum systems by a special mass spectrometric method was presented. The quadrupole mass spectrometer (QMS) and its application in thin film technology was discussed. Results, partial pressure versus time curves as well as the line spectra of the residual gases in case of the vaporization of a Ti-Pd-Au alloy were demonstrated together with the possible construction schemes of QMS residual gas analysers. (Sz.J.)

  6. Drug release from non-aqueous suspensions. II. The release of methylxanthines from paraffin suspensions

    NARCIS (Netherlands)

    Blaey, C.J. de; Fokkens, J.G.


    The release of 3 methylxanthines, i.e. caffeine, theobromine and theophylline, from suspensions in liquid paraffin to an aqueous phase was determined in an in vitro apparatus. The release rates were determined as a function of the pH of the aqueous phase. It was proved that the release process was

  7. Agricultural pesticide residues

    International Nuclear Information System (INIS)

    Fuehr, F.


    The utilization of tracer techniques in the study of agricultural pesticide residues is reviewed under the following headings: lysimeter experiments, micro-ecosystems, translocation in soil, degradation of pesticides in soil, biological availability of soil-applied substances, bound residues in the soil, use of macro- and microautography, double and triple labelling, use of tracer labelling in animal experiments. (U.K.)

  8. Metal Oxide-Carbon Nanocomposites for Aqueous and Nonaqueous Supercapacitors Project (United States)

    National Aeronautics and Space Administration — This Small Business Technology Transfer Phase 2 effort focuses on development of a supercapacitor energy storage device based on novel metal oxide-carbon...

  9. Calcination/dissolution residue treatment

    International Nuclear Information System (INIS)

    Knight, R.C.; Creed, R.F.; Patello, G.K.; Hollenberg, G.W.; Buehler, M.F.; O'Rourke, S.M.; Visnapuu, A.; McLaughlin, D.F.


    Currently, high-level wastes are stored underground in steel-lined tanks at the Hanford site. Current plans call for the chemical pretreatment of these wastes before their immobilization in stable glass waste forms. One candidate pretreatment approach, calcination/dissolution, performs an alkaline fusion of the waste and creates a high-level/low-level partition based on the aqueous solubilities of the components of the product calcine. Literature and laboratory studies were conducted with the goal of finding a residue treatment technology that would decrease the quantity of high-level waste glass required following calcination/dissolution waste processing. Four elements, Fe, Ni, Bi, and U, postulated to be present in the high-level residue fraction were identified as being key to the quantity of high-level glass formed. Laboratory tests of the candidate technologies with simulant high-level residues showed reductive roasting followed by carbonyl volatilization to be successful in removing Fe, Ni, and Bi. Subsequent bench-scale tests on residues from calcination/dissolution processing of genuine Hanford Site tank waste showed Fe was separated with radioelement decontamination factors of 70 to 1,000 times with respect to total alpha activity. Thermodynamic analyses of the calcination of five typical Hanford Site tank waste compositions also were performed. The analyses showed sodium hydroxide to be the sole molten component in the waste calcine and emphasized the requirement for waste blending if fluid calcines are to be achieved. Other calcine phases identified in the thermodynamic analysis indicate the significant thermal reconstitution accomplished in calcination

  10. Handling of Solid Residues

    International Nuclear Information System (INIS)

    Medina Bermudez, Clara Ines


    The topic of solid residues is specifically of great interest and concern for the authorities, institutions and community that identify in them a true threat against the human health and the atmosphere in the related with the aesthetic deterioration of the urban centers and of the natural landscape; in the proliferation of vectorial transmitters of illnesses and the effect on the biodiversity. Inside the wide spectrum of topics that they keep relationship with the environmental protection, the inadequate handling of solid residues and residues dangerous squatter an important line in the definition of political and practical environmentally sustainable. The industrial development and the population's growth have originated a continuous increase in the production of solid residues; of equal it forms, their composition day after day is more heterogeneous. The base for the good handling includes the appropriate intervention of the different stages of an integral administration of residues, which include the separation in the source, the gathering, the handling, the use, treatment, final disposition and the institutional organization of the administration. The topic of the dangerous residues generates more expectation. These residues understand from those of pathogen type that are generated in the establishments of health that of hospital attention, until those of combustible, inflammable type, explosive, radio-active, volatile, corrosive, reagent or toxic, associated to numerous industrial processes, common in our countries in development

  11. Study of residual stresses in welded joints of dual phase HSLA steel used in automotive industry; Estudo das tensoes residuais em juntas soldadas de aco ARBL bifasico usado na industria automobilistica

    Energy Technology Data Exchange (ETDEWEB)

    Barbato, D.S.; Fonseca, M.P. Cindra; Marques Junior, A.S.; Chuvas, T.C.; Pardal, J.M., E-mail: mcindra@vm.uff.b [Universidade Federal Fluminense (PGMEC/UFF), Niteroi, RJ (Brazil). Programa de Pos-graduacao em Engenharia Mecanica; Berretta, J.R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)


    One way of weight reduction in automotive vehicles is through the use of high strength and low alloy (HSLA) steels, which enables the use of small thickness plates. Whereas the appearance of residual stresses is intrinsic to the welding process, this study evaluates the residual stresses generated in welded joints obtained by TIG and LASER welding processes and comparing them. Residual stresses were measured by X-rays diffraction technique, using a portable device with Cr{kappa}{alpha} radiation applying the double exposure method. It also evaluates the influence of shot peening treatment applied after welding, in the bend tests conducted for both welding conditions and TIG welded joints showed higher stability of compressive stresses after welding. The metallographic analysis by optical microscopy complemented the welded joints characterization. (author)

  12. Highly-dispersed Ta-oxide catalysts prepared by electrodeposition in a non-aqueous plating bath for polymer electrolyte fuel cell cathodes

    KAUST Repository

    Seo, Jeongsuk


    The Ta-oxide cathode catalysts were prepared by electrodeposition in a non-aqueous solution. These catalysts showed excellent catalytic activity and have an onset potential of 0.92 V RHE for the oxygen reduction reaction (ORR). The highly-dispersed Ta species at the nanometer scale on the carbon black was an important contributor to the high activity. © 2012 The Royal Society of Chemistry.

  13. A novel green chemistry method for nonaqueous extraction and high-performance liquid chromatography detection of first-, second-, and third-generation tetracyclines, 4-epitetracycline, and tylosin in animal feeds. (United States)

    Granados-Chinchilla, Fabio; Sánchez, Jorge; García, Fernando; Rodríguez, César


    Although tetracyclines and macrolides are common additives for animal nutrition, methods for their simultaneous determination in animal feeds are nonexistent. By coupling an organic extraction and solid-phase extraction cleanup to a high-performance liquid chromatography separation and a nonaqueous postcolumn derivatization, we succeeded in detecting from 0.2 to 24.0 μg kg(-1) of tetracycline, oxytetracycline, chlortetracycline, doxycycline, tigecycline, and 4-epitetracycline in this complex and heterogeneous matrix. Minocycline and tylosin could also be detected with our procedure, but using UV spectrophotometry (1.5 ≤ LOD ≤ 1.9 mg kg(-1)). Linear responses with correlation coefficients between 0.996 and 0.999 were obtained for all analytes in the 0.5-10 mg kg(-1) concentration range. Average recoveries between 59 and 97% and between 98 and 102% were obtained for the tetracyclines and tylosin, respectively. Replicate standard deviations were typically below 5%. When this method was applied to 20 feeds marketed in Costa Rica, we detected labeling inconsistencies, banned mixtures of tetracyclines, and tetracycline concentrations that contravene international regulation.

  14. Development and validation of alternative methods by non-aqueous acid-base titration and derivative ultraviolet spectrophotometry for quantification of sildenafil in raw material and tablets

    Directory of Open Access Journals (Sweden)

    Taízia Dutra Silva


    Full Text Available Sildenafil citrate (SILC is a potent phosphodiesterase-5 inhibitor used for erectile dysfunction and pulmonary hypertension. This study shows two simple, fast and alternative analytical methods for SILC determination by non-aqueous titration and by derivative ultraviolet spectrophotometry (DUS in active pharmaceutical ingredient and/or dosage forms. The quantitation method of SILC active pharmaceutical ingredient by non-aqueous acid-base titration was developed using methanol as solvent and 0.1 mol/L of perchloric acid in acetic acid as titrant. The endpoint was potentiometrically detected. The non-aqueous titration method shows satisfactory repeatability and intermediate precision (RSD 0.70-1.09%. The neutralization reaction occurred in the stoichiometric ratio 1:1 in methanol. The determination of SILC active pharmaceutical ingredient or dosage forms by DUS was developed in the linear range from 10 to 40 µg/mL, in 0.01 mol/L HCl, using the first order zero-peak method at λ 256 nm. The DUS method shows selectivity toward tablets excipients, appropriate linearity (R2 0.9996, trueness (recovery range 98.86-99.30%, repeatability and intermediate precision in three concentration levels (RSD 1.17-1.28%; 1.29-1.71%, respectively. Therefore, the methods developed are excellent alternatives to sophisticated instrumental methods and can be easily applied in any pharmaceutical laboratory routine due to simple and fast executions.

  15. [Residual neuromuscular blockade]. (United States)

    Fuchs-Buder, T; Schmartz, D


    Even small degrees of residual neuromuscular blockade, i. e. a train-of-four (TOF) ratio >0.6, may lead to clinically relevant consequences for the patient. Especially upper airway integrity and the ability to swallow may still be markedly impaired. Moreover, increasing evidence suggests that residual neuromuscular blockade may affect postoperative outcome of patients. The incidence of these small degrees of residual blockade is relatively high and may persist for more than 90 min after a single intubating dose of an intermediately acting neuromuscular blocking agent, such as rocuronium and atracurium. Both neuromuscular monitoring and pharmacological reversal are key elements for the prevention of postoperative residual blockade.

  16. TENORM: Wastewater Treatment Residuals (United States)

    Water and wastes which have been discharged into municipal sewers are treated at wastewater treatment plants. These may contain trace amounts of both man-made and naturally occurring radionuclides which can accumulate in the treatment plant and residuals.

  17. Residuation in orthomodular lattices

    Directory of Open Access Journals (Sweden)

    Chajda Ivan


    Full Text Available We show that every idempotent weakly divisible residuated lattice satisfying the double negation law can be transformed into an orthomodular lattice. The converse holds if adjointness is replaced by conditional adjointness. Moreover, we show that every positive right residuated lattice satisfying the double negation law and two further simple identities can be converted into an orthomodular lattice. In this case, also the converse statement is true and the corresponence is nearly one-to-one.

  18. Characterization of Hospital Residuals

    International Nuclear Information System (INIS)

    Blanco Meza, A.; Bonilla Jimenez, S.


    The main objective of this investigation is the characterization of the solid residuals. A description of the handling of the liquid and gassy waste generated in hospitals is also given, identifying the source where they originate. To achieve the proposed objective the work was divided in three stages: The first one was the planning and the coordination with each hospital center, in this way, to determine the schedule of gathering of the waste can be possible. In the second stage a fieldwork was made; it consisted in gathering the quantitative and qualitative information of the general state of the handling of residuals. In the third and last stage, the information previously obtained was organized to express the results as the production rate per day by bed, generation of solid residuals for sampled services, type of solid residuals and density of the same ones. With the obtained results, approaches are settled down to either determine design parameters for final disposition whether for incineration, trituration, sanitary filler or recycling of some materials, and storage politics of the solid residuals that allow to determine the gathering frequency. The study concludes that it is necessary to improve the conditions of the residuals handling in some aspects, to provide the cleaning personnel of the equipment for gathering disposition and of security, minimum to carry out this work efficiently, and to maintain a control of all the dangerous waste, like sharp or polluted materials. In this way, an appreciable reduction is guaranteed in the impact on the atmosphere. (Author) [es

  19. Validation of welded joint residual stress simulation

    International Nuclear Information System (INIS)

    Computational mechanics is being increasingly applied to predict the state of residual stress in welded joints for nuclear power plant applications. Motives for undertaking such calculations include optimising the design of welded joints and weld procedures, assessing the effectiveness of mitigation processes, providing more realistic inputs to structural integrity assessments and underwriting safety cases for operating nuclear power plant. Fusion welding processes involve intense localised heating to melt the surfaces to be joined and introduction of molten weld filler metal. A complex residual stress field develops at the weld through solidification, differential thermal contraction, cyclic thermal plasticity, phase transformation and chemical diffusion processes. The calculation of weld residual stress involves detailed non-linear analyses where many assumptions and approximations have to be made. In consequence, the accuracy and reliability of solutions can be highly variable. This paper illustrates the degree of variability that can arise in weld residual stress simulation results and summarises the new R6 guidelines which aim to improve the reliability and accuracy of computational predictions. The requirements for validating weld simulations are reviewed where residual stresses are to be used in fracture mechanics analysis. This includes a discussion of how to obtain and interpret measurements from mock-ups, benchmark weldments and published data. Benchmark weldments are described that illustrate some of the issues and show how validation of numerical prediction of weld residual stress can be achieved. Finally, plans for developing the weld modelling guidelines and associated benchmarks are outlined


    Energy Technology Data Exchange (ETDEWEB)

    Michael G. Waddell; William J. Domoracki; Tom J. Temples


    This semi-annual technical progress report is for Task 4 site evaluation, Task 5 seismic reflection design and acquisition, and Task 6 seismic reflection processing and interpretation on DOE contact number DE-AR26-98FT40369. The project had planned one additional deployment to another site other than Savannah River Site (SRS) or DOE Hanford. During this reporting period the project had an ASME peer review. The findings and recommendation of the review panel, as well at the project team response to comments, are in Appendix A. After the SUBCON midyear review in Albuquerque, NM and the peer review it was decided that two additional deployments would be performed. The first deployment is to test the feasibility of using non-invasive seismic reflection and AVO analysis as monitoring to assist in determining the effectiveness of Dynamic Underground Stripping (DUS) in removal of DNAPL. Under the rescope of the project, Task 4 would be performed at the Charleston Navy Weapons Station, Charleston, SC and not at the Dynamic Underground Stripping (DUS) project at SRS. The project team had already completed Task 4 at the M-area seepage basin, only a few hundred yards away from the DUS site. Because the geology is the same, Task 4 was not necessary. However, a Vertical Seismic Profile (VSP) was conducted in one well to calibrate the geology to the seismic data. The first deployment to the DUS Site (Tasks 5 and 6) has been completed. Once the steam has been turned off these tasks will be performed again to compare the results to the pre-steam data. The results from the first deployment to the DUS site indicated a seismic amplitude anomaly at the location and depths of the known high concentrations of DNAPL. The deployment to another site with different geologic conditions was supposed to occur during this reporting period. The first site selected was DOE Paducah, Kentucky. After almost eight months of negotiation, site access was denied requiring the selection of another site. An alternate, site the Department of Defense (DOD) Charleston Navy Weapons Station, Charleston, SC was selected in consultation with National Energy Technology Laboratory (NETL) and DOD Navy Facilities Engineering Command Southern Division (NAVFAC) personnel. Tasks 4, 5, and 6 will be performed at the Charleston Navy Weapons Station. Task 4 will be executed twice. The project team had almost completed Task 4 at Paducah before access was denied.


    Energy Technology Data Exchange (ETDEWEB)

    Michael G. Waddell; William J. Domoracki; Tom J. Temples


    This annual technical progress report is for part of Task 4 (site evaluation), Task 5 (2D seismic design, acquisition, and processing), and Task 6 (2D seismic reflection, interpretation, and AVO analysis) on DOE contact number DE-AR26-98FT40369. The project had planned one additional deployment to another site other than Savannah River Site (SRS) or DOE Hanford Site. After the SUBCON midyear review in Albuquerque, NM, it was decided that two additional deployments would be performed. The first deployment is to test the feasibility of using non-invasive seismic reflection and AVO analysis as a monitoring tool to assist in determining the effectiveness of Dynamic Underground Stripping (DUS) in removal of DNAPL. The second deployment is to the Department of Defense (DOD) Charleston Naval Weapons Station Solid Waste Management Unit 12 (SWMU-12), Charleston, SC to further test the technique to detect high concentrations of DNAPL. The Charleston Naval Weapons Station SWMU-12 site was selected in consultation with National Energy Technology Laboratory (NETL) and DOD Naval Facilities Engineering Command Southern Division (NAVFAC) personnel. Based upon the review of existing data and due to the shallow target depth, the project team collected three Vertical Seismic Profiles (VSP) and an experimental P-wave seismic reflection line. After preliminary data analysis of the VSP data and the experimental reflection line data, it was decided to proceed with Task 5 and Task 6. Three high resolution P-wave reflection profiles were collected with two objectives; (1) design the reflection survey to image a target depth of 20 feet below land surface to assist in determining the geologic controls on the DNAPL plume geometry, and (2) apply AVO analysis to the seismic data to locate the zone of high concentration of DNAPL. Based upon the results of the data processing and interpretation of the seismic data, the project team was able to map the channel that is controlling the DNAPL plume geometry. The AVO analysis located a major amplitude anomaly, which was tested using a Geoprobe{trademark} direct push system. The Geoprobe{trademark} was equipped with a membrane interface probe (MIP) that was interfaced with a sorbent trap/gas chromatograph (GC) system. Both the Photo Ionization Detector (PID) and Electron Capture Detector (ECD) on the GC exceeded the maximum measurement values through the anomaly. A well was installed to collect a water sample. The concentration of chlorinated solvents in the water sample was in excess of 500 ppm. Other amplitude anomalies located directly under an asphalt road were also tested. Both the PID and ECD were zero. It appears that editing of poor quality near-offset traces during data processing caused these anomalies. Not having the full range of source to receiver offset traces in those areas resulted in a false anomaly during AVO analysis. This phenomenon was also observed at the beginning and end of each seismic profile also for the same reason. Based upon the water samples and MIP probes, it appears that surface seismic and AVO analysis were able to detect the area of highest concentration of DNAPL.


    Energy Technology Data Exchange (ETDEWEB)

    Michael G. Waddell; William J. Domoracki; Tom J. Temples


    This semi-annual technical progress report is for part of Task 4 (site evaluation), on DOE contact number DE-AR26-98FT40369. The project had planned one additional deployment to another site other than Savannah River Site (SRS) or DOE Hanford. After the SUBCON midyear review in Albuquerque, NM, it was decided that two additional deployments would be performed. The first deployment is to test the feasibility of using non-invasive seismic reflection and AVO analysis as monitoring to assist in determining the effectiveness of Dynamic Underground Stripping (DUS) in removal of DNAPL. The Second deployment site is the Department of Defense (DOD) Charleston Navy Weapons Station, Solid Waste Management Unit 12 (SWMU-12) Charleston, SC was selected in consultation with National Energy Technology Laboratory (NETL) and DOD Navy Facilities Engineering Command Southern Division (NAVFAC) personnel. Base upon the review of existing data and due to the shallow target depth the project team has collected three Vertical Seismic Profiles (VSP) and experimental reflection line. At the time of preparing this report VSP data and experimental reflection line data has been collected and has have preliminary processing on the data sets.

  3. Metal and hydrocarbon behavior in sediments from Brazilian shallow waters drilling activities using nonaqueous drilling fluids (NAFs). (United States)

    do Carmo R Peralba, Maria; Pozebon, Dirce; dos Santos, João H Z; Maia, Sandra M; Pizzolato, Tânia M; Cioccari, Giovani; Barrionuevo, Simone


    The impact of drilling oil activities in the Brazilian Bonito Field/Campos Basin (Rio de Janeiro) shell drilling (300 m) using nonaqueous fluids (NAFs) was investigated with respect to Al, Fe, Mn, Ba, Co, Pb, Cu, As, Hg, Cr, Ni, Zn, Cd, V, and aliphatic and polynuclear aromatic hydrocarbons concentrations in the sediment. Sampling took place in three different times during approximately 33 months. For the metals Al, As, Co, Cr, Cu, Cd, Fe, Ni, Mn, V, and Zn, no significant variation was observed after drilling activities in most of the stations. However, an increase was found in Ba concentration--due to the drilling activity--without return to the levels found 22 months after drilling. High Ba contents was already detected prior to well drilling, probably due to drilling activities in other wells nearby. Hydrocarbon contents also suggest previous anthropogenic activities. Aliphatic hydrocarbon contents were in the range usually reported in other drilling sites. The same behavior was observed in the case of polyaromatic hydrocarbons. Nevertheless, the n-alkane concentration increased sharply after drilling, returning almost to predrilling levels 22 months after drilling activities.

  4. Cr(VI) adsorption on functionalized amorphous and mesoporous silica from aqueous and non-aqueous media

    International Nuclear Information System (INIS)

    Perez-Quintanilla, Damian; Hierro, Isabel del; Fajardo, Mariano; Sierra, Isabel


    A mesoporous silica (SBA-15) and amorphous silica (SG) have been chemically modified with 2-mercaptopyridine using the homogeneous route. This synthetic route involved the reaction of 2-mercaptopyridine with 3-chloropropyltriethoxysilane prior to immobilization on the support. The resulting material has been characterized by powder X-ray diffraction, nitrogen gas sorption, FT-IR and MAS NMR spectroscopy, thermogravimetry and elemental analysis. The solid was employed as a Cr(VI) adsorbent from aqueous and non-aqueous solutions at room temperature. The effect of several variables (stirring time, pH, metal concentration and solvent polarity) has been studied using the batch technique. The results indicate that under the optimum conditions, the maximum adsorption value for Cr(VI) was 1.83 ± 0.03 mmol/g for MP-SBA-15, whereas the adsorption capacity of the MP-SG was 0.86 ± 0.02 mmol/g. On the basis of these results, it can be concluded that it is possible to modify chemically SBA-15 and SG with 2-mercaptopyridine and to use the resulting modified silicas as effective adsorbents for Cr(VI)

  5. Non-aqueous capillary electrophoresis with red light emitting diode absorbance detection for the analysis of basic dyes. (United States)

    Fakhari, Ali Reza; Breadmore, Michael C; Macka, Miroslav; Haddad, Paul R


    Non-aqueous capillary electrophoresis was evaluated for the separation of five hydrophobic basic blue dyes for application in forensic dye analysis. The use of a red light emitting diode as a high intensity, low-noise light source provided sensitive detection of the blue dyes while also allowing the evaluation of solvents that absorb strongly in the UV region. Excellent peak shapes and separation selectivity were obtained in methanol, ethanol, acetonitrile and dimethylsulfoxide, however water, tetrahydrofuran, dimethylformamide and acetone were unsuitable as solvents due to poor peak shapes and a lack of sensitivity, most likely due to adsorption onto the capillary wall. Due to the known compatibility of methanol with capillary electrophoresis-mass spectrometry, this solvent was examined further with the relative acidity/basicity of the electrolyte being optimised with an artificial neural network. The optimised method was examined for the separation of ink samples from 6 fibre tip and 2 ball point blue or black pens and showed that a unique migration time for the main dye component in seven of the eight pens could be obtained.

  6. Electrochemical characterization of single-walled carbon nanotubes for electrochemical double layer capacitors using non-aqueous electrolyte

    International Nuclear Information System (INIS)

    Ruch, P.W.; Koetz, R.; Wokaun, A.


    Single-walled carbon nanotubes (SWCNTs) were investigated by cyclic voltammetry and electrochemical impedance spectroscopy in a non-aqueous electrolyte, 1 M Et 4 NBF 4 in acetonitrile, suitable for supercapacitors. Further, in situ dilatometry and in situ conductance measurements were performed on single electrodes and the results compared to an activated carbon, YP17. Both materials show capacitive behavior characteristic of high surface area electrodes for supercapacitors, with the maximum full cell gravimetric capacitance being 34 F/g for YP17 and 20 F/g for SWCNTs at 2.5 V with respect to the total active electrode mass. The electronic resistance of SWCNTs and activated carbon decreases significantly during charging, showing similarities of the two materials during electrochemical doping. The SWCNT electrode expands irreversibly during the first electrochemical potential sweep as verified by in situ dilatometry, indicative of at least partial debundling of the SWCNTs. A reversible periodic swelling and shrinking during cycling is observed for both materials, with the magnitude of expansion depending on the type of ions forming the double layer.

  7. Electrochemically synthesized CuInSe2 thin films from non-aqueous electrolyte for solar cell applications (United States)

    Londhe, Priyanka U.; Rohom, Ashwini B.; Lakhe, Manorama G.; Bhand, Ganesh R.; Chaure, Nandu B.


    Highly polycrystalline CuInSe2 (CIS) thin films have been electrodeposited from non-aqueous ethylene glycol (EG) solvent on fluorine-doped tin-oxide-coated glass substrates at 130 °C. The co-deposition potential for Cu, In and Se was optimized by using cyclic voltammetry. CIS layers have been electrodeposited from -1.1 V to -1.5 V versus the Ag/AgCl reference electrode. The effect of selenization on structural, morphological, optical and compositional properties has been studied extensively. Highly crystalline CIS thin films are electrodeposited for all reported growth potentials without post-annealing treatment. The Raman spectra of stoichiometric CIS thin films showed a dominant A1 mode with features receptive to the crystalline quality of the layers. Noticeable changes in the surface morphology and composition of films deposited at different deposition potential were observed. All CIS layers were void free, compact, uniform, and well adherent to the substrates with particle size ˜1-3 μm. Both as-deposited and selenized samples were Cu-rich, however, the composition of selenium remained closer to the ideal value, 50%. A typical solar cell prepared at -1.3 V measured V OC = 0.316 V, J SC = 26 mA, FF = 49, and η = 4.2, under illuminated conditions at 100 mW cm-2.

  8. Fingerprinting of Salvia miltiorrhiza Bunge by non-aqueous capillary electrophoresis compared with high-speed counter-current chromatography. (United States)

    Gu, Ming; Zhang, Shufeng; Su, Zhiguo; Chen, Yi; Ouyang, Fan


    The component of the traditional Chinese medicine (TCM) can be influenced by soil, climate, and growth stage, and fingerprint is an important means in its quality control. Our previous studies showed that high-speed counter-current chromatography (HSCCC) was helpful in the development of fingerprint of TCM. Since the HSCCC method is new, it is necessary to compare it with conventional ones, such as high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC) and high-performance capillary electrophoresis (HPCE). Comparison with HPLC was conducted in our previous study. In this study, HSCCC was compared with non-aqueous capillary electrophoresis (NACE). With NACE, seven stable components were separated within 55 min, respectively, from three crude samples of Salvia miltiorrhiza Bunge from different growth locations. In HSCCC separation, 12 components were separated, respectively, with good correspondence and precision within 13 h. Both NACE and HSCCC were effective in showing whole concentration distribution of all kinds of constituents. Principles of these two methods were very different, which led to different elution sequences and relative contents of peaks. HSCCC showed better performance in analysis of tanshinones, which made its fingerprint containing more chemical information than that of NACE. It was further proven that HSCCC could be a feasible and cost-effective method in the development of the fingerprint of TCM.

  9. Rare-earth metal oxide doped transparent mesoporous silica plates under non-aqueous condition as a potential UV sensor. (United States)

    Lee, Sang-Joon; Park, Sung Soo; Lee, Sang Hyun; Hong, Sang-Hyun; Ha, Chang-Sik


    Transparent mesoporous silica plates doped with rare-earth metal oxide were prepared using solvent-evaporation method based on the self-organization between structure-directing agent and silicate in a non-aqueous solvent. A triblock copolymer, Pluronic (F127 or P123), was used as the structure-directing agent, while tetraethyl orthosilicate (TEOS) was used as a silica source. The pore diameter and the surface area of the mesoporous silica plate prepared with the optimized conditions were ca 40 A and 600 m2 g(-1), respectively, for both structure-directing agent. Rare-earth metal oxides (Eu, Tb, Tm oxide) in mesochannel were formed via one-step synthetic route based on the preparation method of a silica plate. Optical properties of rare-earth metal oxide-doped mesoporous silica plates were investigated by UV irradiation and photoluminescence (PL) spectroscopy. Under the exitation wavelength of 254 nm, the doped mesoporous silica plates emitted red, green and blue for Eu, Tb and Tm oxides, respectively. Rare-earth metal oxide-doped mesoporous silica plates showed enhanced PL intensity compared to that of the bulk rare-earth metal oxide.

  10. Management of NORM Residues

    International Nuclear Information System (INIS)


    The IAEA attaches great importance to the dissemination of information that can assist Member States in the development, implementation, maintenance and continuous improvement of systems, programmes and activities that support the nuclear fuel cycle and nuclear applications, and that address the legacy of past practices and accidents. However, radioactive residues are found not only in nuclear fuel cycle activities, but also in a range of other industrial activities, including: - Mining and milling of metalliferous and non-metallic ores; - Production of non-nuclear fuels, including coal, oil and gas; - Extraction and purification of water (e.g. in the generation of geothermal energy, as drinking and industrial process water; in paper and pulp manufacturing processes); - Production of industrial minerals, including phosphate, clay and building materials; - Use of radionuclides, such as thorium, for properties other than their radioactivity. Naturally occurring radioactive material (NORM) may lead to exposures at some stage of these processes and in the use or reuse of products, residues or wastes. Several IAEA publications address NORM issues with a special focus on some of the more relevant industrial operations. This publication attempts to provide guidance on managing residues arising from different NORM type industries, and on pertinent residue management strategies and technologies, to help Member States gain perspectives on the management of NORM residues

  11. Study on the transport behavior of uranyl nitrate in aqueous and non-aqueous systems

    International Nuclear Information System (INIS)

    Roesel, B.


    The analytical ultracentrifuge has proven itself through diffusion measurements to be well suited for studying radioactive compounds. In the framework of this paper the extent to which the UV and schlieren optics of an analytical ultracentrifuge can be used for extraction-kinetic tests was tested. With this method there is also the possibility of determining the distribution coefficients right at the phase boundary. The results show the good possibility of application of the absorption and schlieren optics to the study of the transport behavior of uranyl nitrate in practice oriented solutions. (orig.) [de

  12. Micro-Encapsulation of non-aqueous solvents for energy-efficient carbon capture

    Energy Technology Data Exchange (ETDEWEB)

    Stolaroff, Joshua K; Ye, Congwang; Oakdale, James [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Baker, Sarah; Nugyen, Du; Smith, William; Aines, Roger


    Here, we demonstrate micro-encapsulation of several promising designer solvents: an IL, PCIL, and CO2BOL. We develop custom polymers that cure by UV light in the presence of each solvent while maintaining high CO2 permeability. We use several new process strategies to accommodate the viscosity and phase changes. We then measure and compare the CO2 absorption rate and capacity as well as the multi-cycle performance of the encapsulated solvents. These results are compared with previous work on encapsulated sodium carbonate solution. The prospects for designer solvents to reduce the cost of post-combustion capture and the implications for process design with encapsulated solvents are discussed.

  13. Residue management in the Bolivia-Brazil gas pipeline construction

    International Nuclear Information System (INIS)

    Freitas, Eduardo Lopes; Henrique, Paulo Roberto Pereira; Cantarino, Anderson Americo Alves


    The construction of the gas pipeline is a process sequential of assembly phases, where each one of those phases generates residues of the most varied types and amounts, being necessary the forecast of your generation in agreement with the activity that is being executed. During the accomplishment of the works they are generated a lot of times situations where are observed the inadequate disposition of the residues. Those practices, besides the environmental impact that they cause, it can cart in the future, the need of additional investments be proceeded in the recovery of the areas and removal of the residues. This work presents the Program of administration of Residues instituted during the construction of the pipeline Bolivia - Brazil, seeking, on a side to reduce to the minimum the generation of residues and of the other, moths handling guidelines and disposition, in way to minimize the environmental impacts caused by the same ones. (author)

  14. Residual-stress measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ezeilo, A.N.; Webster, G.A. [Imperial College, London (United Kingdom); Webster, P.J. [Salford Univ. (United Kingdom)


    Because neutrons can penetrate distances of up to 50 mm in most engineering materials, this makes them unique for establishing residual-stress distributions non-destructively. D1A is particularly suited for through-surface measurements as it does not suffer from instrumental surface aberrations commonly found on multidetector instruments, while D20 is best for fast internal-strain scanning. Two examples for residual-stress measurements in a shot-peened material, and in a weld are presented to demonstrate the attractive features of both instruments. (author).

  15. Separating excess surfactant from silver and gold nanoparticles in micellar concentrates by means of nonaqueous electrophoresis (United States)

    Bulavchenko, A. I.; Demidova, M. G.; Popovetskiy, P. S.; Podlipskaya, T. Yu.; Plyusnin, P. E.


    It is shown by physicochemical means (IR Fourier spectroscopy, CHN-analysis with preliminary sorption of surfactant on SiO2) that the content of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) in an electrophoretic concentrate remains unchanged during the electrophoretic concentration of silver and gold nanoparticles. Diluting the concentrate and carrying out the second stage of electrophoresis reduces the concentration of surfactant from 0.25 to 0.015 M while maintaining the mass concentration of nanoparticles. Nanoparticles in organosols before and after electrophoresis are characterized by means of photon correlation spectroscopy, phase analysis light scattering, and spectrophotometry. Conducting films on glass substrates are obtained from concentrates with a different contents of surfactant via water-alcohol treatment and thermolysis.

  16. Composition of carbonization residues

    Energy Technology Data Exchange (ETDEWEB)

    Hupfer; Leonhardt


    This report compared the composition of samples from Wesseling and Leuna. In each case the sample was a residue from carbonization of the residues from hydrogenation of the brown coal processed at the plant. The composition was given in terms of volatile components, fixed carbon, ash, water, carbon, hydrogen, oxygen, nitrogen, volatile sulfur, and total sulfur. The result of carbonization was given in terms of (ash and) coke, tar, water, gas and losses, and bitumen. The composition of the ash was given in terms of silicon dioxide, ferric oxide, aluminum oxide, calcium oxide, magnesium oxide, potassium and sodium oxides, sulfur trioxide, phosphorus pentoxide, chlorine, and titanium oxide. The most important difference between the properties of the two samples was that the residue from Wesseling only contained 4% oil, whereas that from Leuna had about 26% oil. Taking into account the total amount of residue processed yearly, the report noted that better carbonization at Leuna could save 20,000 metric tons/year of oil. Some other comparisons of data included about 33% volatiles at Leuna vs. about 22% at Wesseling, about 5 1/2% sulfur at Leuna vs. about 6 1/2% at Leuna, but about 57% ash for both. Composition of the ash differed quite a bit between the two. 1 table.

  17. Designing with residual materials

    NARCIS (Netherlands)

    Walhout, W.; Wever, R.; Blom, E.; Addink-Dölle, L.; Tempelman, E.


    Many entrepreneurial businesses have attempted to create value based on the residual material streams of third parties. Based on ‘waste’ materials they designed products, around which they built their company. Such activities have the potential to yield sustainable products. Many of such companies

  18. Sustainable System for Residual Hazards Management

    International Nuclear Information System (INIS)

    Kevin M. Kostelnik; James H. Clarke; Jerry L. Harbour


    Hazardous, radioactive and other toxic substances have routinely been generated and subsequently disposed of in the shallow subsurface throughout the world. Many of today's waste management techniques do not eliminate the problem, but rather only concentrate or contain the hazardous contaminants. Residual hazards result from the presence of hazardous and/or contaminated material that remains on-site following active operations or the completion of remedial actions. Residual hazards pose continued risk to humans and the environment and represent a significant and chronic problem that require continuous long-term management (i.e. >1000 years). To protect human health and safeguard the natural environment, a sustainable system is required for the proper management of residual hazards. A sustainable system for the management of residual hazards will require the integration of engineered, institutional and land-use controls to isolate residual contaminants and thus minimize the associated hazards. Engineered controls are physical modifications to the natural setting and ecosystem, including the site, facility, and/or the residual materials themselves, in order to reduce or eliminate the potential for exposure to contaminants of concern (COCs). Institutional controls are processes, instruments, and mechanisms designed to influence human behavior and activity. System failure can involve hazardous material escaping from the confinement because of system degradation (i.e., chronic or acute degradation) or by external intrusion of the biosphere into the contaminated material because of the loss of institutional control. An ongoing analysis of contemporary and historic sites suggests that the significance of the loss of institutional controls is a critical pathway because decisions made during the operations/remedial action phase, as well as decisions made throughout the residual hazards management period, are key to the long-term success of the prescribed system. In fact

  19. Cobalt and Vanadium Trimetaphosphate Polyanions: Synthesis, Characterization, and Electrochemical Evaluation for Non-aqueous Redox-Flow Battery Applications. (United States)

    Stauber, Julia M; Zhang, Shiyu; Gvozdik, Nataliya; Jiang, Yanfeng; Avena, Laura; Stevenson, Keith J; Cummins, Christopher C


    An electrochemical cell consisting of cobalt ([Co II/III (P 3 O 9 ) 2 ] 4-/3- ) and vanadium ([V III/II (P 3 O 9 ) 2 ] 3-/4- ) bistrimetaphosphate complexes as catholyte and anolyte species, respectively, was constructed with a cell voltage of 2.4 V and Coulombic efficiencies >90% for up to 100 total cycles. The [Co(P 3 O 9 ) 2 ] 4- (1) and [V(P 3 O 9 ) 2 ] 3- (2) complexes have favorable properties for flow-battery applications, including reversible redox chemistry, high stability toward electrochemical cycling, and high solubility in MeCN (1.09 ± 0.02 M, [PPN] 4 [1]·2MeCN; 0.77 ± 0.06 M, [PPN] 3 [2]·DME). The [PPN] 4 [1]·2MeCN and [PPN] 3 [2]·DME salts were isolated as crystalline solids in 82 and 68% yields, respectively, and characterized by 31 P NMR, UV/vis, ESI-MS(-), and IR spectroscopy. The [PPN] 4 [1]·2MeCN salt was also structurally characterized, crystallizing in the monoclinic P2 1 /c space group. Treatment of 1 with [(p-BrC 6 H 4 ) 3 N] + allowed for isolation of the one-electron-oxidized spin-crossover (SCO) complex, [Co(P 3 O 9 ) 2 ] 3- (3), which is the active catholyte species generated during cell charging. The success of the 1-2 cell provides a promising entry point to a potential future class of transition-metal metaphosphate-based all-inorganic non-aqueous redox-flow battery electrolytes.

  20. Solid phase extraction using magnetic core mesoporous shell microspheres with C18-modified interior pore-walls for residue analysis of cephalosporins in milk by LC-MS/MS. (United States)

    Liu, Xiaodan; Yu, Yingjia; Zhao, Meiyan; Zhang, Haiying; Li, Yan; Duan, Gengli


    A fast and effective extraction method has been developed for measuring the residue of cephalosporins (cefalexin, cefazolin, cefoperazone) in milk by using magnetic core-mesoporous shell microspheres with C18-functionalized interior pore-walls (C18-Fe3O4@mSiO2) as adsorbent. With no need for any protein precipitation procedure, the cephalosporins were directly adsorbed onto the C18-Fe3O4@mSiO2 microspheres through hydrophobic interaction with C18-groups (Octadecyl functional groups) functionalized in the interior walls of mesopore channels while the abundant proteins in milk sample were excluded out of the channel due to the size exclusion effect. Thereafter, the cephalosporins-absorbed C18-Fe3O4@mSiO2 microspheres were rapidly isolated by placing a magnet, and followed by liquid chromatography-tandem mass spectrometry analysis after eluted by methanol. Various parameters which could affect the extraction performance were optimised. The newly developed extraction method was successfully applied in determination of cephalosporin residues in milk samples, offering a valuable alternative to simplify and speed up the sample preparation step. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Pickering Interfacial Catalysts for solvent-free biomass transformation: physicochemical behavior of non-aqueous emulsions. (United States)

    Fan, Zhaoyu; Tay, Astrid; Pera-Titus, Marc; Zhou, Wen-Juan; Benhabbari, Samy; Feng, Xiaoshuang; Malcouronne, Guillaume; Bonneviot, Laurent; De Campo, Floryan; Wang, Limin; Clacens, Jean-Marc


    A key challenge in biomass conversion is how to achieve valuable molecules with optimal reactivity in the presence of immiscible reactants. This issue is usually tackled using either organic solvents or surfactants to promote emulsification, making industrial processes expensive and not environmentally friendly. As an alternative, Pickering emulsions using solid particles with tailored designed surface properties can promote phase contact within intrinsically biphasic systems. Here we show that amphiphilic silica nanoparticles bearing a proper combination of alkyl and strong acidic surface groups can generate stable Pickering emulsions of the glycerol/dodecanol system in the temperature range of 35-130°C. We also show that such particles can perform as Pickering Interfacial Catalysts for the acid-catalyzed etherification of glycerol with dodecanol at 150°C. Our findings shed light on some key parameters governing emulsion stability and catalytic activity of Pickering interfacial catalytic systems. This understanding is critical to pave the way toward technological solutions for biomass upgrading able to promote eco-efficient reactions between immiscible organic reagents with neither use of solvents nor surfactants. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Residual stresses in material processing (United States)

    Kozaczek, K. J.; Watkins, T. R.; Hubbard, C. R.; Wang, Xun-Li; Spooner, S.

    Material manufacturing processes often introduce residual stresses into the product. The residual stresses affect the properties of the material and often are detrimental. Therefore, the distribution and magnitude of residual stresses in the final product are usually an important factor in manufacturing process optimization or component life prediction. The present paper briefly discusses the causes of residual stresses. It then addresses the direct, nondestructive methods of residual stress measurement by X ray and neutron diffraction. Examples are presented to demonstrate the importance of residual stress measurement in machining and joining operations.

  3. 78 FR 33008 - Consideration of Rulemaking To Address Prompt Remediation of Residual Radioactivity During... (United States)


    ... Radioactivity During Operations AGENCY: Nuclear Regulatory Commission. ACTION: Notice of public Webinar and... potential rulemaking to address prompt remediation of residual radioactivity during the operational phase of... radioactivity during the operational phase with the objective of avoiding complex decommissioning challenges...

  4. Composition of carbonization residues

    Energy Technology Data Exchange (ETDEWEB)

    Hupfer; Leonhardt


    This report gave a record of the composition of several samples of residues from carbonization of various hydrogenation residue from processing some type of coal or tar in the Bergius process. These included Silesian bituminous coal processed at 600 atm. with iron catalyst, in one case to produce gasoline and middle oil and in another case to produce heavy oil excess, Scholven coal processed at 250 atm. with tin oxalate and chlorine catalyst, Bruex tar processed in a 10-liter oven using iron catalyst, and a pitch mixture from Welheim processed in a 10-liter over using iron catalyst. The values gathered were compared with a few corresponding values estimated for Boehlen tar and Gelsenberg coal based on several assumptions outlined in the report. The data recorded included percentage of ash in the dry residue and percentage of carbon, hydrogen, oxygen, nitrogen, chlorine, total sulfur, and volatile sulfur. The percentage of ash varied from 21.43% in the case of Bruex tar to 53.15% in the case of one of the Silesian coals. Percentage of carbon varied from 44.0% in the case of Scholven coal to 78.03% in the case of Bruex tar. Percentage of total sulfur varied from 2.28% for Bruex tar to a recorded 5.65% for one of the Silesian coals and an estimated 6% for Boehlen tar. 1 table.

  5. Comment on the treatment of residual water content in “A consistent set of parametric models for the two-phase flow of immiscible fluids in the subsurface” by L. Luckner et al. (United States)

    Nimmo, John R.


    Luckner et al. [1989] (hereinafter LVN) present a clear summary and generalization of popular formulations used for convenient representation of porous media fluid flow characteristics, including water content (θ) related to suction (h) and hydraulic conductivity (K) related to θ or h. One essential but problematic element in the LVN models is the concept of residual water content (θr; in LVN, θw,r). Most studies using θr determine its value as a fitted parameter and make the assumption that liquid flow processes are negligible at θ values less than θr. While the LVN paper contributes a valuable discussion of the nature of θr, it leaves several problems unresolved, including fundamental difficulties in associating a definite physical condition with θr, practical inadequacies of the models at low θ values, and difficulties in designating a main wetting curve.


    Sanders, JE; Fatone, S


    Management of residual limb volume affects decisions regarding timing of fit of the first prosthesis, when a new prosthetic socket is needed, design of a prosthetic socket, and prescription of accommodation strategies for daily volume fluctuations. The purpose of this systematic review was to assess what is known about measurement and management of residual limb volume change in persons with lower-limb amputation. Publications that met inclusion criteria were grouped into three categories: (I) descriptions of residual limb volume measurement techniques; (II) studies on people with lower-limb amputation investigating the effect of residual limb volume change on clinical care; and (III) studies of residual limb volume management techniques or descriptions of techniques for accommodating or controlling residual limb volume. The review showed that many techniques for the measurement of residual limb volume have been described but clinical use is limited largely because current techniques lack adequate resolution and in-socket measurement capability. Overall, there is limited evidence regarding the management of residual limb volume, and the evidence available focuses primarily on adults with trans-tibial amputation in the early post-operative phase. While we can draw some insights from the available research about residual limb volume measurement and management, further research is required. PMID:22068373

  7. Improving activity and enantioselectivity of lipase via immobilization on macroporous resin for resolution of racemic 1- phenylethanol in non-aqueous medium (United States)


    Background Burkholderia cepacia lipase (BCL) has been proved to be capable of resolution reactions. However, its free form usually exhibits low stability, bad resistance and no reusability, which restrict its further industrial applications. Therefore, it is of great importance to improve the catalytic performance of free lipase in non-aqueous medium. Results In this work, macroporous resin NKA (MPR-NKA) was utilized as support for lipase immobilization. Racemic transesterification of 1-phenylethanol with vinyl acetate was chosen as model reaction. Compared with its free form, the enzyme activity and enantioselectivity (ees) of the immobilized lipase have been significantly enhanced. The immobilized BCL exhibited a satisfactory thermostability over a wide range of temperature (from 10 to 65°C) and an excellent catalytic efficiency. After being used for more than 30 successive batches, the immobilized lipase still kept most of its activity. In comparison with other immobilized lipases, the immobilized BCL also exhibits better catalytic efficiency, which indicates a significant potential in industrial applications. Conclusion The results of this study have proved that MPR-NKA was an excellent support for immobilization of lipase via the methods of N2 adsorption–desorption, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Fourier transform-infrared spectroscopy (FT-IR). The improvement of enzyme activity and ees for the immobilized lipase was closely correlated with the alteration of its secondary structure. This information may contribute to a better understanding of the mechanism of immobilization and enzymatic biotransformation in non-aqueous medium. PMID:24168516

  8. Quadratic residues and non-residues selected topics

    CERN Document Server

    Wright, Steve


    This book offers an account of the classical theory of quadratic residues and non-residues with the goal of using that theory as a lens through which to view the development of some of the fundamental methods employed in modern elementary, algebraic, and analytic number theory. The first three chapters present some basic facts and the history of quadratic residues and non-residues and discuss various proofs of the Law of Quadratic Reciprosity in depth, with an emphasis on the six proofs that Gauss published. The remaining seven chapters explore some interesting applications of the Law of Quadratic Reciprocity, prove some results concerning the distribution and arithmetic structure of quadratic residues and non-residues, provide a detailed proof of Dirichlet’s Class-Number Formula, and discuss the question of whether quadratic residues are randomly distributed. The text is a valuable resource for graduate and advanced undergraduate students as well as for mathematicians interested in number theory.

  9. Sharing Residual Liability

    DEFF Research Database (Denmark)

    Carbonara, Emanuela; Guerra, Alice; Parisi, Francesco


    Economic models of tort law evaluate the efficiency of liability rules in terms of care and activity levels. A liability regime is optimal when it creates incentives to maximize the value of risky activities net of accident and precaution costs. The allocation of primary and residual liability...... the virtues and limits of loss-sharing rules in generating optimal (second-best) incentives and allocations of risk. We find that loss sharing may be optimal in the presence of countervailing policy objectives, homogeneous risk avoiders, and subadditive risk, which potentially offers a valuable tool...


    Directory of Open Access Journals (Sweden)

    Ainee Irum


    Full Text Available The present study was conducted to evaluate the extent of ß - lactam antibiotic, amoxicillin residues in market milk and meat. Samples were randomly collected from Faisalabad city, Pakistan. High Performance Liquid Chromatography (HPLC method with inflorescent detector was used to detect, identify and quantify the amoxicillin residues in milk and meat samples. The milk samples were purified by performing a protein precipitation step, followed by derivatization. To clean up tissue samples, a liquid extraction, followed by a solid-phase extraction procedure C18 (4.0X4.6mm, 5μm was performed. A 50% meat and 90% milk samples were found contaminated with residues. The residues of amoxicillin in milk were in range of 28 to 46μg/kg and in meat were 9 to 84μg/kg. All of the contaminated milk and 40 out of 50% meat samples fall in maximum residue limits.

  11. Salmon Muscle Adherence to Polymer Coatings and Determination of Antibiotic Residues by Reversed-Phase High-Performance Liquid Chromatography Coupled to Selected Reaction Monitoring Mass Spectrometry, Atomic Force Microscopy, and Fourier Transform Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    E. Zumelzu


    Full Text Available The persistent adhesion of salmon muscle to food container walls after treatment with urea solution was observed. This work evaluated the diffusion of antibiotics from the salmon muscle to the polyethylene terephthalate (PET coating protecting the electrolytic chromium coated steel (ECCS plates. New aquaculture production systems employ antibiotics such as florfenicol, florfenicol amine, oxytetracycline, and erythromycin to control diseases. The introduction of antibiotics is a matter of concern regarding the effects on human health and biodiversity. It is important to determine their impact on the adhesion of postmortem salmon muscle to can walls and the surface and structural changes affecting the functionality of multilayers. This work characterized the changes occurring in the multilayer PET polymer and steel of containers by electron microscopy, 3D atomic force microscopy (3D-AFM, X-ray photoelectron spectroscopy (XPS, and Fourier transform infrared spectroscopy (FT-IR analyses. A robust mass spectrometry methodology was employed to determine the presence of antibiotic residues. No evidence of antibiotics was observed on the protective coating in the range between 0.001 and 2.0 ng/mL; however, the presence of proteins, cholesterol, and alpha-carotene was detected. This in-depth profiling of the matrix-level elements is relevant for the use of adequate materials in the canning export industry.

  12. Bioenergy from sisal residues

    Energy Technology Data Exchange (ETDEWEB)

    Jungersen, G. [Dansk Teknologisk Inst. (Denmark); Kivaisi, A.; Rubindamayugi, M. [Univ. of Dar es Salaam (Tanzania, United Republic of)


    The main objectives of this report are: To analyse the bioenergy potential of the Tanzanian agro-industries, with special emphasis on the Sisal industry, the largest producer of agro-industrial residues in Tanzania; and to upgrade the human capacity and research potential of the Applied Microbiology Unit at the University of Dar es Salaam, in order to ensure a scientific and technological support for future operation and implementation of biogas facilities and anaerobic water treatment systems. The experimental work on sisal residues contains the following issues: Optimal reactor set-up and performance; Pre-treatment methods for treatment of fibre fraction in order to increase the methane yield; Evaluation of the requirement for nutrient addition; Evaluation of the potential for bioethanol production from sisal bulbs. The processing of sisal leaves into dry fibres (decortication) has traditionally been done by the wet processing method, which consumes considerable quantities of water and produces large quantities of waste water. The Tanzania Sisal Authority (TSA) is now developing a dry decortication method, which consumes less water and produces a waste product with 12-15% TS, which is feasible for treatment in CSTR systems (Continously Stirred Tank Reactors). (EG)

  13. Forest residues in cattle feed

    Directory of Open Access Journals (Sweden)

    João Elzeário Castelo Branco Iapichini


    amount of 1% over the live weight + 10% of intake. The results of the first phase of the research, for steers supplemented in pasture, showed good acceptability and consumption in the three levels of substitution, with an average of 3.0 kg of concentrate per head. No rejection was observed for consumption of the mixture, as well as any physiological negative / change and clinical levels tested The pine cone (strobilus without the pine nuts (seeds was obtained as a residue of genetically improved seed collection. Likely source of tannins and fiber, dried and triturated pine cones can contribute to lower production costs due to the substitution of an ingredient in feed formulation, as an aid in control of internal parasites and also in the possible mitigation of methane gas production, resulting from digestion of ruminants, one of the gases responsible for the greenhouse effect. The potential use of pine cone as an ingredient in replacement of roughage and concentrate in the diet of ruminants qualifies as a new source of revenue in pine forestry activity, since no such product currently has no commercial value timber and its accumulation along the dried leaves among the trees, increase the risk of forest fires. Finally, these technological and social innovations result in remarkable potential to leverage Regional Programs Sustainable Development.

  14. Multiresidue analysis of cotton defoliant, herbicide, and insecticide residues in water by solid-phase extraction and GC-NPD, GC-MS, and HPLC-diode array detection. (United States)

    Potter, T L; Marti, L; Belflower, S; Truman, C C


    A multiresidue procedure was developed for analysis of cotton pesticide and harvest-aid chemicals in water using solid-phase extraction and analysis by GC-NPD, GC-MS, and HPLC-DAD. Target compounds included the defoliants tribufos, dimethipin, thidiazuron; the herbicide diuron; and the insecticide methyl parathion. Three solid-phase extraction (SPE) media, octadecylsilyl (ODS), graphitized carbon black (GCB), and a divinylbenzene-N-vinyl pyrollidine copolymer (DVBVP), were evaluated. On GCB and ODS, recoveries varied depending on compound type. Recoveries were quantitative for all compounds on DVBVP, ranging from 87 to 115% in spiked deionized water and surface runoff. The method detection limit was less than 0.1 microg L(-)(1). SPE with DVBVP was applied to post-defoliation samples of surface runoff and tile drainage from a cotton research plot and surface runoff from a commercial field. The research plot was defoliated with a tank mixture of dimethipin and thidiazuron, and the commercial field, with tribufos. Dimethipin was detected (1.9-9.6 microg L(-)(1)) in all research plot samples. In the commercial field samples, tribufos concentration ranged from 0.1 to 135 microg L(-)(1). An exponentially decreasing concentration trend was observed with each successive storm event.

  15. Nonaqueous processing methods

    Energy Technology Data Exchange (ETDEWEB)

    Coops, M.S.; Bowersox, D.F.


    A high-temperature process utilizing molten salt extraction from molten metal alloys has been developed for purification of spent power reactor fuels. Experiments with laboratory-scale processing operations show that purification and throughput parameters comparable to the Barnwell Purex process can be achieved by pyrochemical processing in equipment one-tenth the size, with all wastes being discharged as stable metal alloys at greatly reduced volume and disposal cost. This basic technology can be developed for large-scale processing of spent reactor fuels. 13 references, 4 figures.

  16. Carbonation of residual brines produced by ammonia-soda process (United States)

    Filippova, I. V.; Piriou, P.; Filippov, L. O.; Yvon, J.; Grandjean, M.


    This work deals with the carbonation of residual brines produced during the manufacture of soda ash to avoid the unsuitable phase transformation during the land storage. The study resulted in a demonstration pilot, which showed the feasibility of such an approach and the possibility of his extension to an industrial scale. Carbonation of the residual brines is a promising process as it entirely transforms Ca(OH)2, "CaOHCl" and CSH into calcite, avoids the further phase evolution, allows to obtain a neutral pH which considerably reduce the land storage impact on environment and shorten by around 10 % the global CO2 emission of the ammonia-soda process.

  17. Marine Tar Residues: a Review


    Warnock, April M.; Hagen, Scott C.; Passeri, Davina L.


    Marine tar residues originate from natural and anthropogenic oil releases into the ocean environment and are formed after liquid petroleum is transformed by weathering, sedimentation, and other processes. Tar balls, tar mats, and tar patties are common examples of marine tar residues and can range in size from millimeters in diameter (tar balls) to several meters in length and width (tar mats). These residues can remain in the ocean environment indefinitely, decomposing or becoming buried in ...

  18. Cassava wastewater (manipueira treatment using a two-phase anaerobic biodigestor Tratamento de água residual do processamento de mandioca (manipueira utilizando biodigestor anaeróbio de duas fases

    Directory of Open Access Journals (Sweden)

    Ana Cláudia BARANA


    Full Text Available A two-phase anaerobic biodigestor was employed in order to analyze methane production with different manipueira organic loading rates. The acidogenic phase was carried out in a batch process whereas the methanogenic in an up-flow anaerobic fixed bed reactor with continuous feeding. The organic loading rates varied from 0.33 up to 8.48g of Chemical Demand Oxygen (COD/ The highest content of methane, 80.9%, was obtained with organic loading rate of 0.33g and the lowest, 56.8%, with 8.48gCOD/L.d. The highest reduction of COD, 88.89%, was obtained with organic loading rate of 2.25g and the lowest, 54.95%, with 8.48gCOD/L.d. From these data it was possible to realize that anaerobic biodigestion can be managed in at least two ways, i.e., for energy production (methane or for organic loading reduction. The organic loading rate should be calculated as part of the purpose of the treatment to be accomplished.Um biodigestor anaeróbio de duas fases foi utilizado para se analisar a produção de metano com diferentes cargas de entrada de manipueira. A fase acidogênica foi realizada em processo de batelada e a metanogênica em biodigestor anaeróbio de fluxo ascendente e leito fixo com alimentação contínua. As cargas orgânicas de entrada variaram de 0,33 a 8,48 gDQO (Demanda Química de Oxigênio/L.dia. A maior porcentagem de metano encontrada foi de 80,9%, com carga orgânica de 0,33g e a menor, 56,8%, obtida com 8,49gDQO/L.d. A maior taxa de redução de DQO foi de 88,89%, obtida com carga orgânica de 2,25g e a menor, 54,95%, com 8,48gDQO/L.d. Analisando-se os dados apresentados verificou-se que a biodigestão anaeróbia pode ser conduzida, pelo menos, de duas maneiras, ou seja, para produção de energia (metano ou para redução de carga orgânica. A carga orgânica de entrada deve ser calculada em função do objetivo a ser alcançado com a biodigestão anaeróbia.

  19. X-ray residual stress analysis on machined and tempered HPSN-ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Immelmann, S.; Welle, E.; Reimers, W. [Hahn-Meitner-Institut Berlin GmbH (Germany)


    The residual stress state induced by grinding and tempering of hot pressed silicon nitride (HPSN) samples is studied by X-ray diffraction. The results reveal that the residual stress values at the surface of the samples as well as their gradient within the penetration depth of the X-rays depend on the sintering aid and thus, on the glassy phase content of the HPSN. Tempering of the ground HPSN reduces the residual stress values due to microplastic deformation, whereas an oxidation of the glassy phase leads to the formation of compressive residual stresses. (orig.) 35 refs.

  20. Effect of surfactant species and electrophoretic medium composition on the electrophoretic behavior of neutral and water-insoluble linear synthetic polymers in nonaqueous capillary zone electrophoresis. (United States)

    Fukai, Nao; Kitagawa, Shinya; Ohtani, Hajime


    We have recently demonstrated the separation of neutral and water-insoluble linear synthetic polymers in nonaqueous capillary zone electrophoresis (NACZE) using a cationic surfactant of cetyltrimethylammonium chloride (CTAC). In this study, eight ionic surfactants were investigated for the separation of four synthetic polymers (polystyrene, polymethylmethacrylates, polybutadiene, and polycarbonate); only three surfactants (CTAC, dimethyldioctadecylammonium bromide, and sodium dodecylsulfate) caused their separation. The order of the interaction between the polymers and the surfactants depended on both the surfactant species and the composition of the electrophoretic medium. Their investigation revealed that the separation is majorly affected by the hydrophobic interactions between the polymers and the ionic surfactants. In addition, the electrophoretic behavior of polycarbonate suggested that electrostatic interaction also affects the selectivity of the polymers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Bench-Scale Development of a Non-Aqueous Solvent (NAS) CO2 Capture Process for Coal-Fired Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Lail, Marty


    The project aimed to advance RTI’s non-aqueous amine solvent technology by improving the solvent to reduce volatility, demonstrating long-term continuous operation at lab- (0.5 liters solvent) and bench-scale (~120 liters solvent), showing low reboiler heat duty measured during bench-scale testing, evaluating degradation products, building a rate-based process model, and evaluating the techno-economic performance of the process. The project team (RTI, SINTEF, Linde Engineering) and the technology performed well in each area of advancement. The modifications incorporated throughout the project enabled the attainment of target absorber and regenerator conditions for the process. Reboiler duties below 2,000 kJt/kg CO2 were observed in a bench-scale test unit operated at RTI.

  2. Evaluation of residue-residue contact predictions in CASP9

    KAUST Repository

    Monastyrskyy, Bohdan


    This work presents the results of the assessment of the intramolecular residue-residue contact predictions submitted to CASP9. The methodology for the assessment does not differ from that used in previous CASPs, with two basic evaluation measures being the precision in recognizing contacts and the difference between the distribution of distances in the subset of predicted contact pairs versus all pairs of residues in the structure. The emphasis is placed on the prediction of long-range contacts (i.e., contacts between residues separated by at least 24 residues along sequence) in target proteins that cannot be easily modeled by homology. Although there is considerable activity in the field, the current analysis reports no discernable progress since CASP8.

  3. Measuring the Absorption Rate of CO 2 in Nonaqueous CO 2 -Binding Organic Liquid Solvents with a Wetted-Wall Apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Mathias, Paul M. [Process Technology, Fluor Corporation, 3 Polaris Way Aliso Viejo CA 92698 USA; Zheng, Feng [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99352 USA; Heldebrant, David J. [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99352 USA; Zwoster, Andy [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99352 USA; Whyatt, Greg [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99352 USA; Freeman, Charles M. [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99352 USA; Bearden, Mark D. [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99352 USA; Koech, Phillip [Energy and Environment Directorate, Pacific Northwest National Laboratory, 902 Battelle Boulevard Richland WA 99352 USA


    The kinetics of the absorption of CO2 into two nonaqueous CO2-binding organic liquid (CO2BOL) solvents were measured at T=35, 45, and 55 °C with a wetted-wall column. Selected CO2 loadings were run with a so-called “first-generation” CO2BOL, comprising an independent base and alcohol, and a “second-generation” CO2BOL, in which the base and alcohol were conjoined. Liquid-film mass-transfer coefficient (k'g) values for both solvents were measured to be comparable to values for monoethanolamine and piperazine aqueous solvents under a comparable driving force, in spite of far higher solution viscosities. An inverse temperature dependence of the k'g value was also observed, which suggests that the physical solubility of CO2 in organic liquids may be making CO2 mass transfer faster than expected. Aspen Plus software was used to model the kinetic data and compare the CO2 absorption behavior of nonaqueous solvents with that of aqueous solvent platforms. This work continues our development of the CO2BOL solvents. Previous work established the thermodynamic properties related to CO2 capture. The present paper quantitatively studies the kinetics of CO2 capture and develops a rate-based model.

  4. MnO2-x nanosheets on stainless steel felt as a carbon- and binder-free cathode for non-aqueous lithium-oxygen batteries (United States)

    Wei, Z. H.; Zhao, T. S.; Zhu, X. B.; Tan, P.


    Manganese dioxide (MnO2) has been recognized as an effective catalyst for the oxygen reduction and oxygen evolution reactions in non-aqueous lithium-oxygen batteries. However, a further improvement in battery performance with the MnO2 catalyst is limited by its low electronic conductivity and catalytic activity, which strongly depend on the morphology and composition. In this work, we develop a carbon- and binder-free MnO2-x nanosheets/stainless steel (SS) cathode via a simple and effective electrodeposition-solvothermal route. The created Mn(III) and oxygen vacancy in MnO2-x nanosheets allows an significant increase in the electronic conductivity and catalytic activity. It is experimentally shown that the use of the present nanostructure MnO2-x/SS cathode in a non-aqueous lithium-oxygen battery results in a rechargeable specific capacity of 7300 mAh g-1 at a current density of 200 mA g-1, which is 39% higher than that with the MnO2/SS cathode. In addition, the specific capacities at 400 mA g-1 and 800 mA g-1 reach 5249 mAh g-1 and 2813 mAh g-1, respectively, which are over 30% higher than that with the MnO2/SS cathode. Furthermore, the discharge/charge cycle test shows no degradation for 120 cycles. All the results show that the present nanostructure MnO2-x/SS cathode is a promising candidate for high-performance lithium-oxygen batteries.

  5. Multi-residue method for the determination of over 400 priority and emerging pollutants in water and wastewater by solid-phase extraction and liquid chromatography-time-of-flight mass spectrometry. (United States)

    Robles-Molina, José; Lara-Ortega, Felipe J; Gilbert-López, Bienvenida; García-Reyes, Juan F; Molina-Díaz, Antonio


    This article describes the development and validation of a liquid chromatography high-resolution mass spectrometry method for the simultaneous determination of over 400 multi-class priority and emerging pollutants with different physicochemical properties in environmental waters (surface water and wastewater). The proposed approach is based on the use of a database consisting of retention time/exact mass (of selected ions) pairs implemented with specific software for data analysis. The targeted list comprises 430 contaminants belonging to different compound categories, including 105 multiclass pharmaceuticals (analgesics/anti-inflammatories, antibiotics, lipid regulators, β-blockers, antiepileptic/psychiatrics ulcer healings, diuretics, hormones and bronchodilatadors), life-style products (caffeine, nicotine), 21 drugs of abuse and their metabolites, 279 pesticides and some of their more relevant metabolites, nitrosamines, flame retardants, plasticizers and perfluorinated compounds. The proposed approach included a simple offline solid phase extraction (SPE) step using polymeric cartridges (Oasis HLB) with 200mL of water sample loaded, followed by analysis by rapid resolution liquid chromatography electrospray time-of-flight mass spectrometry (LC-TOFMS) in both positive and negative modes. The identification of the positive findings is accomplished with the data from accurate masses of the target ions along with retention time data and characteristic in-source fragment ions. The overall method performance was satisfactory with limits of quantification lower than 10ngL(-1) for the 44% of studied compounds. Recoveries between 50% and 130% were obtained for the 65% of the analytes (281 compounds). Matrix effects occurring with wastewater matrices were also assessed. The developed method was applied to the determination of target analytes in real surface water and wastewater samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Optimization and application of fabric phase sorptive extraction coupled to ultra-high performance liquid chromatography tandem mass spectrometry for the determination of cytostatic drug residues in environmental waters. (United States)

    Santana-Viera, Sergio; Guedes-Alonso, Rayco; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan; Kabir, Abuzar; Furton, Kenneth G


    Every year, hundreds of tons of organic pollutants reach the environment through effluents released from wastewater treatment plants worldwide, and many of these compounds have harmful effects on the aquatic ecosystem. A new class of emerging pollutants of high concern is cytostatic drugs, which are designed to treat different types of cancers by attacking cells. Environmental concentrations of cytostatic drugs are known to be in the range of ngL -1 , and for this reason, it is imperative to develop analytical methods of extraction and preconcentration to allow for subsequent instrumental analysis of these drugs. In this work, a rapid, simple and green method for the analysis of seven cytostatic drug compounds that are commonly used in anti-cancer therapies was developed using a novel extraction process based on a powerful miniaturized technique, fabric phase sorptive extraction (FPSE) coupled to ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The major parameters that affect the extraction process were optimized. The new method shows good linearity, with a relative standard deviation (RSD) of less than 12%. Relative recoveries higher than 40% were obtained for the studied compounds, and the detection limit of the method was within the values at which these compounds are usually found in environmental water (0.20ngL -1 to 80ngL -1 ). The Limit of Quantification ranged from 0.68 to 267ngL -1 . Significant suppression of the signal due to the matrix effect, a common shortcoming attributed to interference from the extraction process as well as the use of ionization mode, was not observed. Subsequently, the method was applied to real wastewater samples from an effluent obtained from a hospital area and three wastewater treatment plants located in Gran Canaria Island, Spain. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Landfilling of waste incineration residues

    DEFF Research Database (Denmark)

    Christensen, Thomas Højlund; Astrup, Thomas; Cai, Zuansi


    Residues from waste incineration are bottom ashes and air-pollution-control (APC) residues including fly ashes. The leaching of heavy metals and salts from the ashes is substantial and a wide spectrum of leaching tests and corresponding criteria have been introduced to regulate the landfilling...

  8. Advanced new technologies for residue upgrading

    International Nuclear Information System (INIS)

    Gillis, D.


    Viewgraphs summarizing UOP technologies for residue are provided. The upgrading technologies include: (1) Aquaconversion, (2) the Discriminatory Destructive Distillation process (3D), and (3) the RCD uniflex process. The Aquaconversion process is based on catalytic hydrovisbreaking. It makes use of a homogeneous (liquid phase) catalyst. The hydrogen is derived from water. The advantages of this process are improved residue stability and quality at higher conversion levels, high synthetic crude yields, low operational complexity, reduced transportation costs. The 3D process is a unique carbon rejection contaminant removal process which can process whole crudes through viscous residues. FCC type equipment is used. Performance characteristics and advantages of the process were highlighted. The RCD uniflex process makes use of proven fixed bed and ebullated bed technologies in a new process configuration in which the fixed bed system is located upstream of the ebullated bed system. In this process, the catalyst volume increases exponentially with increasing processing severity. Performance characteristics, design features, benefits and development progress to date are described. 1 tab., 21 figs

  9. Determination of maleic hydrazide residues in onion

    Directory of Open Access Journals (Sweden)

    Bursić Vojislava


    Full Text Available A simple HPLC determination method of maleic hydrazide residues in onions was introduced. The homogenized onion samples were extracted with methanol. The crude ex- tract was purified on SPE SampliQ SCX column. The maleic hydrazide was analyzed by HPLC with UV detection of 313 nm. The HPLC separation was performed on SynChropak Q column with 0.25 M phosphate buffer as the mobile phase. The recoveries of maleic hydrazide from the spiked onions with 1.5, 2.0, 3.0, 5.0, 7.0 and 10.0 mg ml-1, ranged from 89-103%. The detection limit of maleic hydrazide was 0.4 mg ml-1, and the quantification limit was 1.25 mg ml-1. The linearity coefficient was 0.9998. Such an optimized method was applied to the determination of residue content of maleic hydrazide in onions, treated with Royal MH-30 in the amount of 8.0 and 12.0 l ha-1. The samples were analysed after 8, 16 and 25 days from the moment of spraying. The obtained values of maleic hydrazide residues were below the maximum tolerable amount in the Republic of Serbia (10 mg kg-1, as well as the amount regulated by the EU (15 mg kg-1. .

  10. Statistical inference on residual life

    CERN Document Server

    Jeong, Jong-Hyeon


    This is a monograph on the concept of residual life, which is an alternative summary measure of time-to-event data, or survival data. The mean residual life has been used for many years under the name of life expectancy, so it is a natural concept for summarizing survival or reliability data. It is also more interpretable than the popular hazard function, especially for communications between patients and physicians regarding the efficacy of a new drug in the medical field. This book reviews existing statistical methods to infer the residual life distribution. The review and comparison includes existing inference methods for mean and median, or quantile, residual life analysis through medical data examples. The concept of the residual life is also extended to competing risks analysis. The targeted audience includes biostatisticians, graduate students, and PhD (bio)statisticians. Knowledge in survival analysis at an introductory graduate level is advisable prior to reading this book.

  11. Automatic prediction of catalytic residues by modeling residue structural neighborhood

    Directory of Open Access Journals (Sweden)

    Passerini Andrea


    Full Text Available Abstract Background Prediction of catalytic residues is a major step in characterizing the function of enzymes. In its simpler formulation, the problem can be cast into a binary classification task at the residue level, by predicting whether the residue is directly involved in the catalytic process. The task is quite hard also when structural information is available, due to the rather wide range of roles a functional residue can play and to the large imbalance between the number of catalytic and non-catalytic residues. Results We developed an effective representation of structural information by modeling spherical regions around candidate residues, and extracting statistics on the properties of their content such as physico-chemical properties, atomic density, flexibility, presence of water molecules. We trained an SVM classifier combining our features with sequence-based information and previously developed 3D features, and compared its performance with the most recent state-of-the-art approaches on different benchmark datasets. We further analyzed the discriminant power of the information provided by the presence of heterogens in the residue neighborhood. Conclusions Our structure-based method achieves consistent improvements on all tested datasets over both sequence-based and structure-based state-of-the-art approaches. Structural neighborhood information is shown to be responsible for such results, and predicting the presence of nearby heterogens seems to be a promising direction for further improvements.

  12. Effect of pasteurization on the residues of tetracyclines in milk

    Directory of Open Access Journals (Sweden)

    Eva Kellnerová


    Full Text Available The main aim of this work was to determine the effect of high pasteurization of milk (85 °C/3 s on the residues of tetracycline and oxytetracycline. The samples of raw cow’s milk, purchased from a vending machine, were spiked with standard solutions of tetracycline and oxytetracycline. The content of the residues of tetracycline antibiotics was measured before and after heating. Pre-cleaned samples were extracted by a mixed-mode solid phase extraction technique and analysed using high performance liquid chromatography/diode array detection. Whereas the residues of tetracycline decreased only by 5.74% and were not significantly different (P > 0.05, the residues of oxytetracycline decreased by 15.3% and this distinction was highly significant (P ≤ 0.01. Based on the results of our study, the tetracycline antibiotics were proved to have differences in the thermostability of particular substances at pasteurisation temperatures.

  13. Residual stresses and fatigue in a duplex stainless steel

    International Nuclear Information System (INIS)

    Johansson, Johan


    Duplex stainless steels, consisting of approximately equal amounts of austenite and ferrite, often combine the best features of austenitic and ferritic stainless steels. They generally have good mechanical properties, including high strength and ductility, and the corrosion resistance is often better than conventional austenitic grades. This has lead to a growing use of duplex stainless steels as a material in mechanically loaded constructions. However, detailed knowledge regarding its mechanical properties and deformation mechanisms are still lacking. In this thesis special emphasis has been placed on the residual stresses and their influence on mechanical behaviour of duplex stainless steels. Due to the difference in coefficient of thermal expansion between the two phases, tensile microstresses are found in the austenitic phase and balancing compressive microstresses in the ferritic phase. The first part of this thesis is a literature survey, which will give an introduction to duplex stainless steels and review the fatigue properties of duplex stainless steels and the influence of residual stresses in two-phase material. The second part concerns the evolution of the residual stress state during uniaxial loading. Initial residual stresses were found to be almost two times higher in the transverse direction compared to the rolling direction. During loading the absolute value of the microstresses increased in the macroscopic elastic regime but started to decrease with increasing load in the macroscopic plastic regime. A significant increase of the microstresses was also found to occur during unloading. Finite element simulations also show stress variation within one phase and a strong influence of both the elastic and plastic anisotropy of the individual phases on the simulated stress state. In the third part, the load sharing between the phases during cyclic loading is studied. X-ray diffraction stress analysis and transmission electron microscopy show that even if

  14. Residual stresses and fatigue in a duplex stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Johan


    Duplex stainless steels, consisting of approximately equal amounts of austenite and ferrite, often combine the best features of austenitic and ferritic stainless steels. They generally have good mechanical properties, including high strength and ductility, and the corrosion resistance is often better than conventional austenitic grades. This has lead to a growing use of duplex stainless steels as a material in mechanically loaded constructions. However, detailed knowledge regarding its mechanical properties and deformation mechanisms are still lacking. In this thesis special emphasis has been placed on the residual stresses and their influence on mechanical behaviour of duplex stainless steels. Due to the difference in coefficient of thermal expansion between the two phases, tensile microstresses are found in the austenitic phase and balancing compressive microstresses in the ferritic phase. The first part of this thesis is a literature survey, which will give an introduction to duplex stainless steels and review the fatigue properties of duplex stainless steels and the influence of residual stresses in two-phase material. The second part concerns the evolution of the residual stress state during uniaxial loading. Initial residual stresses were found to be almost two times higher in the transverse direction compared to the rolling direction. During loading the absolute value of the microstresses increased in the macroscopic elastic regime but started to decrease with increasing load in the macroscopic plastic regime. A significant increase of the microstresses was also found to occur during unloading. Finite element simulations also show stress variation within one phase and a strong influence of both the elastic and plastic anisotropy of the individual phases on the simulated stress state. In the third part, the load sharing between the phases during cyclic loading is studied. X-ray diffraction stress analysis and transmission electron microscopy show that even if

  15. Computation of Phase Equilibrium and Phase Envelopes

    DEFF Research Database (Denmark)

    Ritschel, Tobias Kasper Skovborg; Jørgensen, John Bagterp

    In this technical report, we describe the computation of phase equilibrium and phase envelopes based on expressions for the fugacity coefficients. We derive those expressions from the residual Gibbs energy. We consider 1) ideal gases and liquids modeled with correlations from the DIPPR database...... and 2) nonideal gases and liquids modeled with cubic equations of state. Next, we derive the equilibrium conditions for an isothermal-isobaric (constant temperature, constant pressure) vapor-liquid equilibrium process (PT flash), and we present a method for the computation of phase envelopes. We...... formulate the involved equations in terms of the fugacity coefficients. We present expressions for the first-order derivatives. Such derivatives are necessary in computationally efficient gradient-based methods for solving the vapor-liquid equilibrium equations and for computing phase envelopes. Finally, we...

  16. 40 CFR Appendix 6 to Subpart A of... - Reverse Phase Extraction (RPE) Method for Detection of Oil Contamination in Non-Aqueous Drilling... (United States)


    ... exposure. In addition, all sample preparation should be conducted in a well-ventilated area to limit the... duplicate samples to document accuracy and precision. The procedure for the preparation and analysis of... Part 435 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND...

  17. Influence of Wetting and Mass Transfer Properties of Organic Chemical Mixtures in Vadose Zone Materials on Groundwater Contamination by Nonaqueous Phase Liquids

    Energy Technology Data Exchange (ETDEWEB)

    Charles J Werth; Albert J Valocchi, Hongkyu Yoon


    Previous studies have found that organic acids, organic bases, and detergent-like chemicals change surface wettability. The wastewater and NAPL mixtures discharged at the Hanford site contain such chemicals, and their proportions likely change over time due to reaction-facilitated aging. The specific objectives of this work were to (1) determine the effect of organic chemical mixtures on surface wettability, (2) determine the effect of organic chemical mixtures on CCl4 volatilization rates from NAPL, and (3) accurately determine the migration, entrapment, and volatilization of organic chemical mixtures. Five tasks were proposed to achieve the project objectives. These are to (1) prepare representative batches of fresh and aged NAPL-wastewater mixtures, (2) to measure interfacial tension, contact angle, and capillary pressure-saturation profiles for the same mixtures, (3) to measure interphase mass transfer rates for the same mixtures using micromodels, (4) to measure multiphase flow and interphase mass transfer in large flow cell experiments, all using the same mixtures, and (5) to modify the multiphase flow simulator STOMP in order to account for updated P-S and interphase mass transfer relationships, and to simulate the impact of CCl4 in the vadose zone on groundwater contamination. Results and findings from these tasks and summarized in the attached final report.

  18. Clustering-driven residue filter for profile measurement system. (United States)

    Jiang, Jun; Cheng, Jun; Zhou, Ying; Chen, Guang


    The profile measurement system is widely used in industrial quality control, and phase unwrapping (PU) is a key technique. An algorithm-driven PU is often used to reduce the impact of noise-induced residues to retrieve the most reliable solution. However, measuring speed is lowered due to the searching of optimal integration paths or correcting of phase gradients. From the viewpoint of the rapidity of the system, this paper characterizes the noise-induced residues, and it proposes a clustering-driven residue filter based on a set of directional windows. The proposed procedure makes the wrapped phases included in the filtering window have more similar values, and it groups the correct and noisy phases into individual clusters along the local fringe direction adaptively. It is effective for the tightly packed fringes, and it converts the algorithm-driven PU to the residue-filtering-driven one. This improves the operating speed of the 3D reconstruction significantly. The tests performed on simulated and real projected fringes confirm the validity of our approach.

  19. 342 analytical investigation of selected pesticide residues from fruits

    African Journals Online (AJOL)


    Keywords: Pesticide residues, reverse phase high performance liquid chromatography, chlorpyrifos, ... liquid chromatography hyphenated with tandem ..... Toxicology,. Applications. Toronto: Wiley-VCH. p. 541. Ortelli, D., Edder, P. and Corvi, C. (2004),. Multiresidue analysis of 74 pesticides in fruits and vegetables by liquid.

  20. Analytical investigation of selected pesticide residues from fruits and ...

    African Journals Online (AJOL)

    Pesticide residues like chlorpyrifos, cypermethrin, deltamethrin and dichlorvos were monitored by an improved extraction method from apple, peach and potato using reverse phase high performance liquid chromatography. The selected pesticides were extracted from fruits and vegetable samples using smaller volume of ...

  1. Interplay between symmetries and residual interactions in rotating nuclei

    International Nuclear Information System (INIS)

    Cwiok, S.; Kvasil, J.; Nazmitdinov, R.G.


    Using the space rotation and translation invariance of the nuclear Hamiltonian, the residual interactions for a rotating nucleus are constructed. The connection is found between the Goldstone modes of motion (spurious states) and the symmetries of equations of motion in Random Phase Approximation for states near the yrast line. (author). 18 figs


    This document describes the residual risk assessment for the Ethylene Oxide Commercial Sterilization source category. For stationary sources, section 112 (f) of the Clean Air Act requires EPA to assess risks to human health and the environment following implementation of technology-based control standards. If these technology-based control standards do not provide an ample margin of safety, then EPA is required to promulgate addtional standards. This document describes the methodology and results of the residual risk assessment performed for the Ethylene Oxide Commercial Sterilization source category. The results of this analyiss will assist EPA in determining whether a residual risk rule for this source category is appropriate.

  3. Hanford tank residual waste - Contaminant source terms and release models

    International Nuclear Information System (INIS)

    Deutsch, William J.; Cantrell, Kirk J.; Krupka, Kenneth M.; Lindberg, Michael L.; Jeffery Serne, R.


    Highlights: → Residual waste from five Hanford spent fuel process storage tanks was evaluated. → Gibbsite is a common mineral in tanks with high Al concentrations. → Non-crystalline U-Na-C-O-P ± H phases are common in the U-rich residual. → Iron oxides/hydroxides have been identified in all residual waste samples. → Uranium release is highly dependent on waste and leachant compositions. - Abstract: Residual waste is expected to be left in 177 underground storage tanks after closure at the US Department of Energy's Hanford Site in Washington State, USA. In the long term, the residual wastes may represent a potential source of contamination to the subsurface environment. Residual materials that cannot be completely removed during the tank closure process are being studied to identify and characterize the solid phases and estimate the release of contaminants from these solids to water that might enter the closed tanks in the future. As of the end of 2009, residual waste from five tanks has been evaluated. Residual wastes from adjacent tanks C-202 and C-203 have high U concentrations of 24 and 59 wt.%, respectively, while residual wastes from nearby tanks C-103 and C-106 have low U concentrations of 0.4 and 0.03 wt.%, respectively. Aluminum concentrations are high (8.2-29.1 wt.%) in some tanks (C-103, C-106, and S-112) and relatively low ( 2 -saturated solution, or a CaCO 3 -saturated water. Uranium release concentrations are highly dependent on waste and leachant compositions with dissolved U concentrations one or two orders of magnitude higher in the tests with high U residual wastes, and also higher when leached with the CaCO 3 -saturated solution than with the Ca(OH) 2 -saturated solution. Technetium leachability is not as strongly dependent on the concentration of Tc in the waste, and it appears to be slightly more leachable by the Ca(OH) 2 -saturated solution than by the CaCO 3 -saturated solution. In general, Tc is much less leachable (<10 wt.% of the

  4. Residual stress analysis: a review

    International Nuclear Information System (INIS)

    Finlayson, T.R.


    The techniques which are or could be employed to measure residual stresses are outlined. They include X-ray and neutron diffraction. Comments are made on the reliability and accuracy to be expected from particular techniques

  5. OECD Maximum Residue Limit Calculator (United States)

    With the goal of harmonizing the calculation of maximum residue limits (MRLs) across the Organisation for Economic Cooperation and Development, the OECD has developed an MRL Calculator. View the calculator.

  6. Vesícula residual

    Directory of Open Access Journals (Sweden)

    Júlio C. U. Coelho

    Full Text Available Our objective is to report three patients with recurrent severe upper abdominal pain secondary to residual gallbladder. All patients had been subjected to cholecystectomy from 1 to 20 years before. The diagnosis was established after several episodes of severe upper abdominal pain by imaging exams: ultrasonography, tomography, or endoscopic retrograde cholangiography. Removal of the residual gallbladder led to complete resolution of symptoms. Partial removal of the gallbladder is a very rare cause of postcholecystectomy symptoms.

  7. Marine Tar Residues: a Review. (United States)

    Warnock, April M; Hagen, Scott C; Passeri, Davina L

    Marine tar residues originate from natural and anthropogenic oil releases into the ocean environment and are formed after liquid petroleum is transformed by weathering, sedimentation, and other processes. Tar balls, tar mats, and tar patties are common examples of marine tar residues and can range in size from millimeters in diameter (tar balls) to several meters in length and width (tar mats). These residues can remain in the ocean environment indefinitely, decomposing or becoming buried in the sea floor. However, in many cases, they are transported ashore via currents and waves where they pose a concern to coastal recreation activities, the seafood industry and may have negative effects on wildlife. This review summarizes the current state of knowledge on marine tar residue formation, transport, degradation, and distribution. Methods of detection and removal of marine tar residues and their possible ecological effects are discussed, in addition to topics of marine tar research that warrant further investigation. Emphasis is placed on benthic tar residues, with a focus on the remnants of the Deepwater Horizon oil spill in particular, which are still affecting the northern Gulf of Mexico shores years after the leaking submarine well was capped.

  8. Effect of shot peening treatment in the behavior of residual stress in duplex stainless steel during medium cycle fatigue

    International Nuclear Information System (INIS)

    Pedrosa, Peter D.S.; Rebello, Joao Marcos A.; Fonseca, Maria P. Cindra


    The lifetime of duplex stainless steel parts experiencing cyclic fatigue is directly influenced by the residual stresses present in the ferrite and austenite phases. The motivation for this work was to analyze the behaviour of the residual stresses fields introduced by shot peening treatment in both phases, in the sample surface as in the subsurface layers, in low fatigue cycles, using the X-rays diffraction technique. The results shows that the compressive residual stresses introduced by the shot peening treatment in both phases improved fatigue life of the material. However, the cyclical loads produce partial or total relief in these residual stresses fields. It was verified that the shot peening process induced the formation of microcracks only in the ferrite phase. The largest variations in the total compressive residual stresses fields also occurred in this phase. The samples surfaces were analyzed by scanning electron microscopy. (author)

  9. On tide-induced Lagrangian residual current and residual transport: 2. Residual transport with application in south San Francisco Bay, California (United States)

    Feng, Shizuo; Cheng, Ralph T.; Pangen, Xi


    The transports of solutes and other tracers are fundamental to estuarine processes. The apparent transport mechanisms are convection by tidal current and current-induced shear effect dispersion for processes which take place in a time period of the order of a tidal cycle. However, as emphasis is shifted toward the effects of intertidal processes, the net transport is mainly determined by tide-induced residual circulation and by residual circulation due to other processes. The commonly used intertidal conservation equation takes the form of a convection-dispersion equation in which the convective velocity is the Eulerian residual current, and the dispersion terms are often referred to as the phase effect dispersion or, sometimes, as the “tidal dispersion.” The presence of these dispersion terms is merely the result of a Fickian type hypothesis. Since the actual processes are not Fickian, thus a Fickian hypothesis obscures the physical significance of this equation. Recent research results on residual circulation have suggested that long-term transport phenomena are closely related to the Lagrangian residual current or the Lagrangian residual transport. In this paper a new formulation of an intertidal conservation equation is presented and examined in detail. In a weakly nonlinear tidal estuary the resultant intertidal transport equation also takes the form of a convection-dispersion equation without the ad hoc introduction of phase effect dispersion in a form of dispersion tensor. The convective velocity in the resultant equation is the first-order Lagrangian residual current (the sum of the Eulerian residual current and the Stokes drift). The remaining dispersion terms are important only in higher-order solutions; they are due to shear effect dispersion and turbulent mixing. There exists a dispersion boundary layer adjacent to shoreline boundaries. An order of magnitude estimate of the properties in the dispersion boundary layer is given. The present treatment

  10. Biodrying of animal slaughterhouse residues and heat production

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, Y. [Centre de recherche industrielle, Quebec City, PQ (Canada)


    Animal carcasses from slaughterhouses are usually composted on farms, but the composting process is not optimized and a large volumes of carbonaceous residues are needed. This type of composting takes place over a period of 6 to 9 months in a nonaerated static pile. Quebec's industrial research centre (CRIQ) developed an organic biodrying process (BIOSECO) adapted to large-scale operations in order to optimize the treatment of slaughterhouse residues. Biodrying is a form of composting, in which the thermophilic phase is optimized, making it possible to evaporate large amounts of water. Biodrying is done inside a building and reduces the amount of carbonaceous residues considerably. The process is optimized by the sequence in which the slaughterhouse residues are added, the choice of input and the aeration flow. Slaughterhouse residues can be treated non-stop throughout the entire year. Since the odours are nearly completed limited to the building, the biodrying can be done near the slaughterhouse. A large amount of heat was produced by the process during the pilot project. It was concluded that the BIOSECO biodrying process is suitable for treating slaughterhouse residues in an effective and economic manner, and has the added advantage of producing heat that could be used for various purposes.

  11. Evaluation of residue-residue contact prediction in CASP10

    KAUST Repository

    Monastyrskyy, Bohdan


    We present the results of the assessment of the intramolecular residue-residue contact predictions from 26 prediction groups participating in the 10th round of the CASP experiment. The most recently developed direct coupling analysis methods did not take part in the experiment likely because they require a very deep sequence alignment not available for any of the 114 CASP10 targets. The performance of contact prediction methods was evaluated with the measures used in previous CASPs (i.e., prediction accuracy and the difference between the distribution of the predicted contacts and that of all pairs of residues in the target protein), as well as new measures, such as the Matthews correlation coefficient, the area under the precision-recall curve and the ranks of the first correctly and incorrectly predicted contact. We also evaluated the ability to detect interdomain contacts and tested whether the difficulty of predicting contacts depends upon the protein length and the depth of the family sequence alignment. The analyses were carried out on the target domains for which structural homologs did not exist or were difficult to identify. The evaluation was performed for all types of contacts (short, medium, and long-range), with emphasis placed on long-range contacts, i.e. those involving residues separated by at least 24 residues along the sequence. The assessment suggests that the best CASP10 contact prediction methods perform at approximately the same level, and comparably to those participating in CASP9.

  12. Mineral phases in raw and processed municipal waste incineration residues


    Bayuseno, Athanasius Priharyoto (Dipl.)


    Die Eigenschaften von Filterstäuben und Schlacken aus deutschen Müllverbrennungsanlagen (MVA) und der chemisch-mineralogische Umsatz von Filterstäuben wurden mit dem Ziel erforscht, die enthaltenen Schwermetalle durch kristallchemische Substitution in beständigen Mineralphasen zu immobilisieren. Die Hauptgemengteile der frischen Schlacken sind Silikate und Oxide, außerdem ist ein hoher Gehalt an Glas vorhanden. Die frischen Filterstäube erhalten eine erhebliche Menge Glas und unterschiedliche...

  13. Enhanced flexoelectricity through residual ferroelectricity in barium strontium titanate

    International Nuclear Information System (INIS)

    Garten, Lauren M.; Trolier-McKinstry, Susan


    Residual ferroelectricity is observed in barium strontium titanate ceramics over 30 °C above the global phase transition temperature, in the same temperature range in which anomalously large flexoelectric coefficients are reported. The application of a strain gradient leads to strain gradient-induced poling or flexoelectric poling. This was observed by the development of a remanent polarization in flexoelectric measurements, an induced d 33 piezoelectric response even after the strain gradient was removed, and the production of an internal bias of 9 kV m −1 . It is concluded that residual ferroelectric response considerably enhances the observed flexoelectric response

  14. Enhanced flexoelectricity through residual ferroelectricity in barium strontium titanate

    Energy Technology Data Exchange (ETDEWEB)

    Garten, Lauren M., E-mail:; Trolier-McKinstry, Susan [Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)


    Residual ferroelectricity is observed in barium strontium titanate ceramics over 30 °C above the global phase transition temperature, in the same temperature range in which anomalously large flexoelectric coefficients are reported. The application of a strain gradient leads to strain gradient-induced poling or flexoelectric poling. This was observed by the development of a remanent polarization in flexoelectric measurements, an induced d{sub 33} piezoelectric response even after the strain gradient was removed, and the production of an internal bias of 9 kV m{sup −1}. It is concluded that residual ferroelectric response considerably enhances the observed flexoelectric response.

  15. Enhanced flexoelectricity through residual ferroelectricity in barium strontium titanate (United States)

    Garten, Lauren M.; Trolier-McKinstry, Susan


    Residual ferroelectricity is observed in barium strontium titanate ceramics over 30 °C above the global phase transition temperature, in the same temperature range in which anomalously large flexoelectric coefficients are reported. The application of a strain gradient leads to strain gradient-induced poling or flexoelectric poling. This was observed by the development of a remanent polarization in flexoelectric measurements, an induced d33 piezoelectric response even after the strain gradient was removed, and the production of an internal bias of 9 kV m-1. It is concluded that residual ferroelectric response considerably enhances the observed flexoelectric response.

  16. Residual stresses around Vickers indents

    International Nuclear Information System (INIS)

    Pajares, A.; Guiberteau, F.; Steinbrech, R.W.


    The residual stresses generated by Vickers indentation in brittle materials and their changes due to annealing and surface removal were studied in 4 mol% yttria partially stabilized zirconia (4Y-PSZ). Three experimental methods to gain information about the residual stress field were applied: (i) crack profile measurements based on serial sectioning, (ii) controlled crack propagation in post indentation bending tests and (iii) double indentation tests with smaller secondary indents located around a larger primary impression. Three zones of different residual stress behavior are deduced from the experiments. Beneath the impression a crack free spherical zone of high hydrostatic stresses exists. This core zone is followed by a transition regime where indentation cracks develop but still experience hydrostatic stresses. Finally, in an outward third zone, the crack contour is entirely governed by the tensile residual stress intensity (elastically deformed region). Annealing and surface removal reduce this crack driving stress intensity. The specific changes of the residual stresses due to the post indentation treatments are described and discussed in detail for the three zones

  17. Model Of Relaxation Of Residual Stresses In Hot-Rolled Strips

    Directory of Open Access Journals (Sweden)

    Milenin A.


    Full Text Available Residual stresses in hot-rolled strips are of practical importance when the laser cutting of these strip is applied. The factors influencing the residual stresses include the non uniform distribution of elastic-plastic deformations, phase transformation occurring during cooling and stress relaxation during rolling and cooling. The latter factor, despite its significant effect on the residual stress, is scarcely considered in the scientific literature. The goal of the present study was development of a model of residual stresses in hot-rolled strips based on the elastic-plastic material model, taking into account the stress relaxation.

  18. Rapid microwave-assisted nonaqueous synthesis and growth mechanism of AgCl/Ag, and its daylight-driven plasmonic photocatalysis. (United States)

    Jiang, Jing; Zhang, Lizhi


    We report on a rapid microwave-assisted nonaqueous synthesis and the growth mechanism of AgCl/Ag with controlled size and shape. By rationally varying the reaction temperature and the microwave irradiation time, we achieved the transformation of nanocubes to rounded triangular pyramids by a combined process of "oriented attachment" and Ostwald ripening. The surface plasmon resonance (SPR) properties of the as-prepared AgCl/Ag have been found to be somewhat dependent on the size, morphology, and composition. The as-prepared AgCl/Ag exhibits high photocatalytic activity and good reusability for decomposing organic pollutants (such as methyl orange (MO), rhodamine B (RhB), and pentachlorophenol (PCP)) under indoor artificial daylight illumination (ca. 1 mW cm(-2)). The AgCl/Ag has also been found to display a superior ability to harvest diffuse indoor daylight (ca. 5 mW cm(-2)), and could complete the degradation of 10 mg  L(-1) MO within 15 min. Experiments involving the trapping of active species have shown that the photocatalytic degradation of organic pollutants in the AgCl/Ag system may proceed through direct hole transfer. This study has revealed that plasmonic daylight photocatalysis may open a new frontier for indoor pollutant control around the clock under fluorescent lamp illumination. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Determination of subcellular concentrations of soluble carbohydrates in rose petals during opening by nonaqueous fractionation method combined with infiltration-centrifugation method. (United States)

    Yamada, Kunio; Norikoshi, Ryo; Suzuki, Katsumi; Imanishi, Hideo; Ichimura, Kazuo


    Petal growth associated with flower opening depends on cell expansion. To understand the role of soluble carbohydrates in petal cell expansion during flower opening, changes in soluble carbohydrate concentrations in vacuole, cytoplasm and apoplast of petal cells during flower opening in rose (Rosa hybrida L.) were investigated. We determined the subcellular distribution of soluble carbohydrates by combining nonaqueous fractionation method and infiltration-centrifugation method. During petal growth, fructose and glucose rapidly accumulated in the vacuole, reaching a maximum when petals almost reflected. Transmission electron microscopy showed that the volume of vacuole and air space drastically increased with petal growth. Carbohydrate concentration was calculated for each compartment of the petal cells and in petals that almost reflected, glucose and fructose concentrations increased to higher than 100 mM in the vacuole. Osmotic pressure increased in apoplast and symplast during flower opening, and this increase was mainly attributed to increases in fructose and glucose concentrations. No large difference in osmotic pressure due to soluble carbohydrates was observed between the apoplast and symplast before flower opening, but total osmotic pressure was much higher in the symplast than in the apoplast, a difference that was partially attributed to inorganic ions. An increase in osmotic pressure due to the continued accumulation of glucose and fructose in the symplast may facilitate water influx into cells, contributing to cell expansion associated with flower opening under conditions where osmotic pressure is higher in the symplast than in the apoplast.

  20. Adsorption of non-ionic ABC triblock copolymers: Surface modification of TiO2 suspensions in aqueous and non-aqueous medium (United States)

    Lerch, Jean-Philippe; Atanase, Leonard Ionut; Riess, Gérard


    A series of non-ionic ABC triblock copolymers, such as poly(butadiene)-b-poly(2-vinylpyrridine)-b-poly(ethylene oxide) (PB-P2VP-PEO) were synthesized by sequential anionic polymerizations. For these copolymers comprising an organo-soluble PB and a water-soluble PEO block, their P2VP middle block has been selected for its anchoring capacity on solid surfaces. The adsorption isotherms on TiO2 were obtained in heptane and in aqueous medium, as selective solvents. In both of these cases, the P2VP middle block provides the surface anchoring, whereas PB and PEO sequences are acting as stabilizing moieties in heptane and water respectively. By extension to ABC triblock copolymers of the scaling theory developed for diblock copolymers, the density of adsorbed chains could be correlated with the molecular characteristics of the PB-P2VP-PEO triblock copolymers. From a practical point a view, it could be demonstrated that these copolymers are efficient dispersing agents for the TiO2 pigments in both aqueous and non-aqueous medium.

  1. Analysis of dissolution residues of irradiated fuels

    International Nuclear Information System (INIS)

    Regnaud, F.; Tcherniatine, N.


    In the industrial dissolution conditions obtaining in reprocessing plants, the acid digests the irradiated nuclear fuels and leaves an insoluble product. This phenomenon is particularly conspicuous in the case of the UO 2 , PuO 2 mixed oxides of the fast neutron system irradiated at high specific burn-up. It is observed to a lesser degree in the case of UO 2 oxides of the ordinary water system. The quantity of insoluble product appears to depend on the specific burn-up. These residues are attributed to metallic phases comprising uranium, plutonium, ruthenium, palladium, rhodium and molybdenum. Owing to the existence of these residues, the radioactivity of which is high, the reprocessing plant requires a separation process, particular care in order to avoid their build-up, and packaging and storage facilities. This is why a programme on the physical-chemical study of the compounds has been initiated to develop a chemical digestion method, elemental analysis methods and the study of certain physical parameters such as granulometry [fr

  2. Residual stress in ceramics and ceramic composites

    International Nuclear Information System (INIS)

    Oden, M.


    Residual stresses in Si 3 N 4 and SiC have been measured with X-ray diffraction after grinding and thermal shock. The produced surface stresses are compressive after both treatments. The stresses show a strong dependence on the quenching temperature up to a certain temperature when cracks relax the stresses. The influence of the amount of reinforcing phase on the residual stress state in a Al 2 O 3 /SiC whisker composite was investigated and correlated to a modified Eshelby model. The agreement is excellent. The composite was quenched in liquid He (4K) and the stress state measured after show no relaxation of stresses, indicating elastic behaviour. An in situ strain measurement as a function of temperature conducted on a Al 2 O 3 /SiC whisker composite and a SiC/TiB 2 particle composite show very good agreement with the Eshelby model for the Al 2 O 3 /SiC system but not agreement for the SiC/TiB 2 system. The reason is believed to be stress relaxation during sample preparation. (au) (53 refs., 24 figs., 14 tabs.)

  3. Actinide recovery from pyrochemical residues

    International Nuclear Information System (INIS)

    Avens, L.R.; Clifton, D.G.; Vigil, A.R.


    A new process for recovery of plutonium and americium from pyrochemical waste has been demonstrated. It is based on chloride solution anion exchange at low acidity, which eliminates corrosive HCl fumes. Developmental experiments of the process flowsheet concentrated on molten salt extraction (MSE) residues and gave >95% plutonium and >90% americium recovery. The recovered plutonium contained 6 = from high chloride-low acid solution. Americium and other metals are washed from the ion exchange column with 1N HNO 3 -4.8M NaCl. The plutonium is recovered, after elution, via hydroxide precipitation, while the americium is recovered via NaHCO 3 precipitation. All filtrates from the process are discardable as low-level contaminated waste. Production-scale experiments are now in progress for MSE residues. Flow sheets for actinide recovery from electrorefining and direct oxide reduction residues are presented and discussed

  4. Actinide recovery from pyrochemical residues

    International Nuclear Information System (INIS)

    Avens, L.R.; Clifton, D.G.; Vigil, A.R.


    We demonstrated a new process for recovering plutonium and americium from pyrochemical waste. The method is based on chloride solution anion exchange at low acidity, or acidity that eliminates corrosive HCl fumes. Developmental experiments of the process flow chart concentrated on molten salt extraction (MSE) residues and gave >95% plutonium and >90% americium recovery. The recovered plutonium contained 6 2- from high-chloride low-acid solution. Americium and other metals are washed from the ion exchange column with lN HNO 3 -4.8M NaCl. After elution, plutonium is recovered by hydroxide precipitation, and americium is recovered by NaHCO 3 precipitation. All filtrates from the process can be discardable as low-level contaminated waste. Production-scale experiments are in progress for MSE residues. Flow charts for actinide recovery from electro-refining and direct oxide reduction residues are presented and discussed

  5. Alternatives to crop residues for soil amendment


    Powell, J.M.; Unger, P.W.


    Metadata only record In semiarid agroecosystems, crop residues can provide important benefits of soil and water conservation, nutrient cycling, and improved subsequent crop yields. However, there are frequently multiple competing uses for residues, including animal forage, fuel, and construction material. This chapter discusses the various uses of crop residues and examines alternative soil amendments when crop residues cannot be left on the soil.

  6. Stabilization of distearoylphosphatidylcholine lamellar phases in propylene glycol using cholesterol. (United States)

    Harvey, Richard D; Ara, Nargis; Heenan, Richard K; Barlow, David J; Quinn, Peter J; Lawrence, M Jayne


    Phospholipid vesicles (liposomes) formed in pharmaceutically acceptable nonaqueous polar solvents such as propylene glycol are of interest in drug delivery because of their ability to improve the bioavailability of drugs with poor aqueous solubility. We have demonstrated a stabilizing effect of cholesterol on lamellar phases formed by dispersion of distearoylphosphatidylcholine (DSPC) in water/propylene glycol (PG) solutions with glycol concentrations ranging from 0 to 100%. The stability of the dispersions was assessed by determining the effect of propylene glycol concentration on structural parameters of the lamellar phases using a complementary combination of X-ray and neutron scattering techniques at 25 °C and in the case of X-ray scattering at 65 °C. Significantly, although stable lamellar phases (and liposomes) were formed in all PG solutions at 25 °C, the association of the glycol with the liposomes' lamellar structures led to the formation of interdigitated phases, which were not thermostable at 65 °C. With the addition of equimolar quantities of cholesterol to the dispersions of DSPC, stable lamellar dispersions (and indeed liposomes) were formed in all propylene glycol solutions at 25 °C, with the significant lateral phase separation of the bilayer components only detectable in propylene glycol concentrations above 60% (w/w). We propose that the stability of lamellar phases of the cholesterol-containing liposomes formed in propylene glycol concentrations of up to 60% (w/w) represent potentially very valuable drug delivery vehicles for a variety of routes of administration.

  7. Leaching From Biomass Gasification Residues

    DEFF Research Database (Denmark)

    Allegrini, Elisa; Boldrin, Alessio; Polletini, A.


    The aim of the present work is to attain an overall characterization of solid residues from biomass gasification. Besides the determination of chemical and physical properties, the work was focused on the study of leaching behaviour. Compliance and pH-dependence leaching tests coupled with geoche......The aim of the present work is to attain an overall characterization of solid residues from biomass gasification. Besides the determination of chemical and physical properties, the work was focused on the study of leaching behaviour. Compliance and pH-dependence leaching tests coupled...

  8. Carbaryl residues in maize products

    International Nuclear Information System (INIS)

    Zayed, S.M.A.D.; Mansour, S.A.; Mostafa, I.Y.; Hassan, A.


    The 14 C-labelled insecticide carbaryl was synthesized from [1- 14 C]-1-naphthol at a specific activity of 3.18mCig -1 . Maize plants were treated with the labelled insecticide under simulated conditions of agricultural practice. Mature plants were harvested and studied for distribution of total residues in untreated grains as popularly roasted and consumed, and in the corn oil and corn germ products. Total residues found under these conditions in the respective products were 0.2, 0.1, 0.45 and 0.16ppm. (author)

  9. Combinatorial construction of toric residues


    Khetan, Amit; Soprounov, Ivan


    The toric residue is a map depending on n+1 semi-ample divisors on a complete toric variety of dimension n. It appears in a variety of contexts such as sparse polynomial systems, mirror symmetry, and GKZ hypergeometric functions. In this paper we investigate the problem of finding an explicit element whose toric residue is equal to one. Such an element is shown to exist if and only if the associated polytopes are essential. We reduce the problem to finding a collection of partitions of the la...

  10. Neutron and X-ray residual stress measurements of WC-Co alloys

    Energy Technology Data Exchange (ETDEWEB)

    Akiniwa, Yoshiaki; Tanaka, Keisuke [Dept. of Mechanical Engineering, Nagoya Univ. (Japan); Minakawa, Nobuaki; Morii, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kamiyama, Takashi [Tsukuba Univ., Ibaraki (Japan). Inst. of Materials Science


    As cemented carbides composed of metal carbides and pure metals had low deformation and excellent abrasion resistance at high temperature, they are used for various kinds of machining tools. As WC-Co is a typical cemented carbides, some residual stress when sintering a mixed molding of powdered WC and Co at 1400 to 1450 centigrade were introduced into the alloy, to largely affect strength of its materials. In this study, by using WC-Co alloys with various Co contents, thermal residual stress at each composing phase was tested by using X-ray and neutron methods, to investigate on effect of the Co content on the residual stress. And, a comparison with forecasting values using intercalated matters theory was also investigated. As a result, it was found that on the X-ray method, as thermal compressive residual stress increased with increase of content in Co phase, at more than 23.6 % it reduced and residual stress on vertical direction of specimen surface was nearly zero. And, it was also found that on neutron diffraction using angular dispersion method, residual stress in WC phase well agreed with forecasting value using the intercalated matters theory. Furthermore, it was also found that residual stress, when compensated by tested results of WC phase on 36.9 % material obtained by the angular dispersion method, showed good agreement with the forecasting values without relation to its testing methods. (G.K.)

  11. Neutron and X-ray residual stress measurements of WC-Co alloys

    International Nuclear Information System (INIS)

    Akiniwa, Yoshiaki; Tanaka, Keisuke; Minakawa, Nobuaki; Morii, Yukio; Kamiyama, Takashi


    As cemented carbides composed of metal carbides and pure metals had low deformation and excellent abrasion resistance at high temperature, they are used for various kinds of machining tools. As WC-Co is a typical cemented carbides, some residual stress when sintering a mixed molding of powdered WC and Co at 1400 to 1450 centigrade were introduced into the alloy, to largely affect strength of its materials. In this study, by using WC-Co alloys with various Co contents, thermal residual stress at each composing phase was tested by using X-ray and neutron methods, to investigate on effect of the Co content on the residual stress. And, a comparison with forecasting values using intercalated matters theory was also investigated. As a result, it was found that on the X-ray method, as thermal compressive residual stress increased with increase of content in Co phase, at more than 23.6 % it reduced and residual stress on vertical direction of specimen surface was nearly zero. And, it was also found that on neutron diffraction using angular dispersion method, residual stress in WC phase well agreed with forecasting value using the intercalated matters theory. Furthermore, it was also found that residual stress, when compensated by tested results of WC phase on 36.9 % material obtained by the angular dispersion method, showed good agreement with the forecasting values without relation to its testing methods. (G.K.)

  12. Bi-Metallic Composite Structures With Designed Internal Residual Stress Field (United States)

    Brice, Craig A.


    Shape memory alloys (SMA) have a unique ability to recover small amounts of plastic strain through a temperature induced phase change. For these materials, mechanical displacement can be accomplished by heating the structure to induce a phase change, through which some of the plastic strain previously introduced to the structure can be reversed. This paper introduces a concept whereby an SMA phase is incorporated into a conventional alloy matrix in a co-continuous reticulated arrangement forming a bi-metallic composite structure. Through memory activation of the mechanically constrained SMA phase, a controlled residual stress field is developed in the interior of the structure. The presented experimental data show that the memory activation of the SMA composite component significantly changes the residual stress distribution in the overall structure. Designing the structural arrangement of the two phases to produce a controlled residual stress field could be used to create structures that have much improved durability and damage tolerance properties.

  13. A single-step pesticide extraction and clean-up multi-residue analytical method by selective pressurized liquid extraction followed by on-line solid phase extraction and ultra-high-performance liquid chromatography-tandem mass spectrometry for complex matrices. (United States)

    Rodrigues, Elsa Teresa; Pardal, Miguel Ângelo; Salgueiro-González, Noelia; Muniategui-Lorenzo, Soledad; Alpendurada, Maria Fátima


    Pesticides, a group of compounds linked to human activity, may, when in toxic levels, have a profound effect on water quality, and hence result in adverse consequences to aquatic life and ultimately to human health. Analytical challenges arise when successfully trying to determine these levels in environmental complex matrices. Therefore, fast, simple, sensitive and selective analytical methodologies for multi-residue determination of pesticides (atrazine, azoxystrobin, bentazon, λ-cyhalothrin, penoxsulam and terbuthylazine) in sediment, macrophytes (algae and aquatic plants) and aquatic animals were developed and validated. The established methods were matrix-dependent and were based on Selective Pressurized Liquid Extraction (SPLE) followed by on-line Solid Phase Extraction and Ultra Performance Liquid Chromatography-tandem Mass Spectrometry (on-line SPE-UPLC-ESI-MS/MS). This cutting-edge research methodology uses a small amount of sample, is time saving and reduces the use of organic solvents in compliance with Green Chemistry principles. The analytical features were adequate for all compounds in all studied matrices. The established methodology was applied on real marine samples and no pesticide concentrations above their respective method quantification limits were measured in sediments or aquatic plants. However, terbuthylazine was found in the macroalgae Ulva spp. (108ngg(-1)dw) and all the prospected pesticides were measured above their respective method quantification limits in the bivalve Scrobicularia plana (atrazine: 48ngg(-1)dw, azoxystrobin: 64ngg(-1)dw, bentazon: 33ngg(-1)dw, λ-cyhalothrin: 2531ngg(-1)dw, penoxsulam: 50ngg(-1)dw, and terbuthylazine: 44ngg(-1)dw). Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Assessment of heterogeneity of residual variances using changepoint techniques

    Directory of Open Access Journals (Sweden)

    Toro Miguel A


    Full Text Available Abstract Several studies using test-day models show clear heterogeneity of residual variance along lactation. A changepoint technique to account for this heterogeneity is proposed. The data set included 100 744 test-day records of 10 869 Holstein-Friesian cows from northern Spain. A three-stage hierarchical model using the Wood lactation function was employed. Two unknown changepoints at times T1 and T2, (0 T1 T2 tmax, with continuity of residual variance at these points, were assumed. Also, a nonlinear relationship between residual variance and the number of days of milking t was postulated. The residual variance at a time t( in the lactation phase i was modeled as: for (i = 1, 2, 3, where λι is a phase-specific parameter. A Bayesian analysis using Gibbs sampling and the Metropolis-Hastings algorithm for marginalization was implemented. After a burn-in of 20 000 iterations, 40 000 samples were drawn to estimate posterior features. The posterior modes of T1, T2, λ1, λ2, λ3, , , were 53.2 and 248.2 days; 0.575, -0.406, 0.797 and 0.702, 34.63 and 0.0455 kg2, respectively. The residual variance predicted using these point estimates were 2.64, 6.88, 3.59 and 4.35 kg2 at days of milking 10, 53, 248 and 305, respectively. This technique requires less restrictive assumptions and the model has fewer parameters than other methods proposed to account for the heterogeneity of residual variance during lactation.

  15. Weld Residual Stress in Corner Boxing Joints


    Kazuyoshi, Matsuoka; Tokuharu, Yoshii; Ship Research Institute, Ministry of Transport; Ship Research Institute, Ministry of Transport


    Fatigue damage often occurs in corner boxing welded joints because of stress concentration and residual stress. The hot spot stress approach is applicable to stress concentration. However, the number of suitable methods for estimating residual stress in welded joints is limited. The purpose of this paper is to clarify the residual stress in corner boxing joints. The method of estimating residual stresses based on the inherent stress technique is presented. Residual stress measurements are per...

  16. Solidification process for sludge residue

    International Nuclear Information System (INIS)

    Pearce, K.L.


    This report investigates the solidification process used at 100-N Basin to solidify the N Basin sediment and assesses the N Basin process for application to the K Basin sludge residue material. This report also includes a discussion of a solidification process for stabilizing filters. The solidified matrix must be compatible with the Environmental Remediation Disposal Facility acceptance criteria

  17. Machine Arithmetic in Residual Classes, (United States)


    rsmainder/residue, as this ascape /-nsues from thp determination of system. It can be. zaalizpd ;n the presence of th- arithmetic urit, which wor~s in thz sys...modules Nj. Page 417. Proof. Proof ascaps /ensues directly from the theorem of Gauss. Actually/really, since according to condition (py, qj)-=-. then

  18. Residual stress in polyethylene pipes

    Czech Academy of Sciences Publication Activity Database

    Poduška, Jan; Hutař, Pavel; Kučera, J.; Frank, A.; Sadílek, J.; Pinter, G.; Náhlík, Luboš


    Roč. 54, SEP (2016), s. 288-295 ISSN 0142-9418 R&D Projects: GA MŠk LM2015069; GA MŠk(CZ) LQ1601 Institutional support: RVO:68081723 Keywords : polyethylene pipe * residual stress * ring slitting method * lifetime estimation Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.464, year: 2016

  19. Managing woodwaste: Yield from residue

    Energy Technology Data Exchange (ETDEWEB)

    Nielson, E. [LNS Services, Inc., North Vancouver, British Columbia (Canada); Rayner, S. [Pacific Waste Energy Inc., Burnaby, British Columbia (Canada)


    Historically, the majority of sawmill waste has been burned or buried for the sole purpose of disposal. In most jurisdictions, environmental legislation will prohibit, or render uneconomic, these practices. Many reports have been prepared to describe the forest industry`s residue and its environmental effect; although these help those looking for industry-wide or regional solutions, such as electricity generation, they have limited value for the mill manager, who has the on-hands responsibility for generation and disposal of the waste. If the mill manager can evaluate waste streams and break them down into their usable components, he can find niche market solutions for portions of the plant residue and redirect waste to poor/no-return, rather than disposal-cost, end uses. In the modern mill, residue is collected at the individual machine centre by waste conveyors that combine and mix sawdust, shavings, bark, etc. and send the result to the hog-fuel pile. The mill waste system should be analyzed to determine the measures that can improve the quality of residues and determine the volumes of any particular category before the mixing, mentioned above, occurs. After this analysis, the mill may find a niche market for a portion of its woodwaste.

  20. Leptogenesis and residual CP symmetry

    International Nuclear Information System (INIS)

    Chen, Peng; Ding, Gui-Jun; King, Stephen F.


    We discuss flavour dependent leptogenesis in the framework of lepton flavour models based on discrete flavour and CP symmetries applied to the type-I seesaw model. Working in the flavour basis, we analyse the case of two general residual CP symmetries in the neutrino sector, which corresponds to all possible semi-direct models based on a preserved Z 2 in the neutrino sector, together with a CP symmetry, which constrains the PMNS matrix up to a single free parameter which may be fixed by the reactor angle. We systematically study and classify this case for all possible residual CP symmetries, and show that the R-matrix is tightly constrained up to a single free parameter, with only certain forms being consistent with successful leptogenesis, leading to possible connections between leptogenesis and PMNS parameters. The formalism is completely general in the sense that the two residual CP symmetries could result from any high energy discrete flavour theory which respects any CP symmetry. As a simple example, we apply the formalism to a high energy S 4 flavour symmetry with a generalized CP symmetry, broken to two residual CP symmetries in the neutrino sector, recovering familiar results for PMNS predictions, together with new results for flavour dependent leptogenesis.

  1. Solow Residuals Without Capital Stocks

    DEFF Research Database (Denmark)

    Burda, Michael C.; Severgnini, Battista


    We use synthetic data generated by a prototypical stochastic growth model to assess the accuracy of the Solow residual (Solow, 1957) as a measure of total factor productivity (TFP) growth when the capital stock in use is measured with error. We propose two alternative measurements based on current...

  2. Acid transformation of bauxite residue: Conversion of its alkaline characteristics. (United States)

    Kong, Xiangfeng; Li, Meng; Xue, Shengguo; Hartley, William; Chen, Chengrong; Wu, Chuan; Li, Xiaofei; Li, Yiwei


    Bauxite residue (BR) is a highly alkaline solid hazardous waste produced from bauxite processing for alumina production. Alkaline transformation appears to reduce the environmental risk of bauxite residue disposal areas (BRDAs) whilst potentially providing opportunities for the sustainable reuse and on-going management of BR. Mineral acids, a novel citric acid and a hybrid combination of acid-gypsum treatments were investigated for their potential to reduce residue pH and total alkalinity and transform the alkaline mineral phase. XRD results revealed that with the exception of andradite, the primary alkaline solid phases of cancrinite, grossular and calcite were transformed into discriminative products based on the transformation used. Supernatants separated from BR and transformed bauxite residue (TBR) displayed distinct changes in soluble Na, Ca and Al, and a reduction in pH and total alkalinity. SEM images suggest that mineral acid transformations promote macro-aggregate formation, and the positive promotion of citric acid, confirming the removal or reduction in soluble and exchangeable Na. NEXAFS analysis of Na K-edge revealed that the chemical speciation of Na in TBRs was consistent with BR. Three acid treatments and gypsum combination had no effect on Na speciation, which affects the distribution of Na revealed by sodium STXM imaging. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. In situ non-aqueous nucleation and growth of next generation rare-earth-free permanent magnets. (United States)

    Yoon, Hyojung; Xu, Aoran; Sterbinsky, George E; Arena, Dario A; Wang, Ziying; Stephens, Peter W; Meng, Ying Shirley; Carroll, Kyler J


    Using a controllable wet chemical approach, the polyol process, we developed a cobalt carbide nanomagnet consisting of an assembly of Co2C and Co3C nanoparticles as an alternative to rare earth permanent magnets (PMs). The thermodynamically stable mixed phase cobalt carbide nanoparticles are shown to be acicular in morphology. Their exchange-coupled magnetic interaction possessing high maximum energy product of 20.7 kJ m(-3) and room temperature coercivity (2.9 kOe) has been confirmed through vibrating sample magnetometer (VSM) and first order reversal curves (FORCs). These metastable carbide nanoparticles offer improved magnetic properties compared to their pure bulk form. An understanding of the formation mechanism, using in situ time-resolved X-ray spectroscopy (TR-XAS), and the correlation between phase contributions to the properties are described in detail. Our strategy presents a controllable route to preparing the cobalt carbide nanomagnets, which could be potentially useful in permanent magnet clean energy applications. Additionally, the in situ apparatus offers a promising way to directly explore the effects of reaction variables for high-temperature wet chemical reactions.

  4. Analytical Methods for Detonation Residues of Insensitive Munitions (United States)

    Walsh, Marianne E.


    Analytical methods are described for the analysis of post-detonation residues from insensitive munitions. Standard methods were verified or modified to obtain the mass of residues deposited per round. In addition, a rapid chromatographic separation was developed and used to measure the mass of NTO (3-nitro-1,2,4-triazol-5-one), NQ (nitroguanidine) and DNAN (2,4-dinitroanisole). The HILIC (hydrophilic-interaction chromatography) separation described here uses a trifunctionally-bonded amide phase to retain the polar analytes. The eluent is 75/25 v/v acetonitrile/water acidified with acetic acid, which is also suitable for LC/MS applications. Analytical runtime was three minutes. Solid phase extraction and LC/MS conditions are also described.

  5. Radioactive material in residues of health services residues

    International Nuclear Information System (INIS)

    Costa R, A. Jr.; Recio, J.C.


    The work presents the operational actions developed by the one organ responsible regulator for the control of the material use radioactive in Brazil. Starting from the appearance of coming radioactive material of hospitals and clinical with services of nuclear medicine, material that that is picked up and transported in specific trucks for the gathering of residuals of hospital origin, and guided one it manufactures of treatment of residuals of services of health, where they suffer radiological monitoring before to guide them for final deposition in sanitary embankment, in the city of Sao Paulo, Brazil. The appearance of this radioactive material exposes a possible one violation of the norms that govern the procedures and practices in that sector in the country. (Author)


    African Journals Online (AJOL)

    Therefore 85 kg ha-1 N as labelled ammonium sulfate (9.764% atomic excess) was applied in a three-split application. Fertiliser N recovery by wheat in the first year was 33.1%. At harvest, 64.8% of fertiliser N was found in the 0 - 80 cm profile as residual fertiliser-derived N; 2.1% of the applied N could not be accounted for ...

  7. Experimental determination and theoretical analysis of local residual stress at grain scale

    NARCIS (Netherlands)

    Basu, Indranil; Ocelík, Václav; De Hosson, Jeff Th M.


    Grain/phase boundaries contribute significantly to build up of residual stresses, owing to varied plastic/thermal response of different grain orientations or phases during thermomechanical treatment. Hence, accurate quantification of such local scale stress gradients in commercial components is

  8. Raman study of molecular dynamics of inorganic fluoroxidizers in nonaqueous solutions: part 4. Xenon tetrafluoride and xenon hexafluoride in hydrogen fluoride. (United States)

    Nabiev, S S


    Raman spectra of XeF4 and XeF6 in the nonaqueous HF solutions at various concentrations and vibrational spectra of the [XeF5]+ cation in the solid state and in the HF solutions over a wide range of vibrational frequencies have been studied. The assignments of the observed vibrational bands of the [XeF5]+ cation and XeF6-HF system has been made. A number of associates or solvates being formed as a result of the donor-acceptor interaction between Lewis base and Lewis acid has been shown to exist alongside with ionized monomeric and polymeric modifications of XeF6 in the HF solution such as ([XeF5]+ F-)n (n = 1, 2, 4). The contours of the nu1(A1g) band of XeF4 with frequency 552 cm(-1) and bands of stretching modes of ([XeF5]+ F-)n (n = 1, 2, 4) with frequency in the range of 600-670 cm(-1) are analysed. The correlation functions of the vibrational and rotational relaxation as well as the corresponding characteristic time for these processes have been calculated. A conclusion has been driven at that it is vibrational dephasing that makes the major contribution to the formation of ([XeF5]+ F)4 and ([XeF5]+ F-)2 band contours, while in the case of [XeF5]+ F- and XeF4 the contributions of vibrational dephasing and rotational relaxation nearly coincide.

  9. Effects of non-aqueous fluids-associated drill cuttings discharge on shelf break macrobenthic communities in the Campos Basin, Brazil. (United States)

    Santos, Maria Fernanda L; Silva, Janete; Fachel, Jandyra M G; Pulgati, Fernando H


    This paper assesses the effects of non-aqueous fluids (NAF)-associated drill cuttings discharge on shelf break macrobenthic communities in the Campos Basin, off the southeast Brazilian coast, Rio de Janeiro State. Samples were taken with a 0.25-m2 box corer from surrounding two oil and gas wells on three monitoring cruises: before drilling, three months after drilling, and 22 months after drilling. Statistical methodologies used Bayesian geostatistical and analysis of variance models to evaluate the effects of the NAF-associated drill cuttings discharge and to define the impact area. The results indicated that marked variations were not observed in the number of families between cruises, though there were changes in the fauna composition. The changes seen in biological descriptors in both control and background situation areas were not considered significant, showing a temporal homogeneity in means. The impact area presented changes in biological descriptors of communities and trophic structure during the three cruises and such changes were correlated to chemical and physical variables related to the drilling activities, as a result of the mix of drill cuttings and sediment and the anoxic conditions established in the substrate. In that area, three months after drilling, a decrease in diversity and an increase in density, motile deposit-feeders and Pol/Crp ratio, and dominance of opportunistic organisms, such as the capitellid Capitella sp., were observed and, 22 months after drilling, an increase of diversity, reduction of dominance of capitellid polychaete, changes in the fauna composition, and a dominance of opportunistic burrowing and tube-building organisms were observed, indicating an ecological succession process.

  10. Compositional modeling of three-phase flow with gravity using higher-order finite element methods

    KAUST Repository

    Moortgat, Joachim


    A wide range of applications in subsurface flow involve water, a nonaqueous phase liquid (NAPL) or oil, and a gas phase, such as air or CO2. The numerical simulation of such processes is computationally challenging and requires accurate compositional modeling of three-phase flow in porous media. In this work, we simulate for the first time three-phase compositional flow using higher-order finite element methods. Gravity poses complications in modeling multiphase processes because it drives countercurrent flow among phases. To resolve this issue, we propose a new method for the upwinding of three-phase mobilities. Numerical examples, related to enhanced oil recovery and carbon sequestration, are presented to illustrate the capabilities of the proposed algorithm. We pay special attention to challenges associated with gravitational instabilities and take into account compressibility and various phase behavior effects, including swelling, viscosity changes, and vaporization. We find that the proposed higher-order method can capture sharp solution discontinuities, yielding accurate predictions of phase boundaries arising in computational three-phase flow. This work sets the stage for a broad extension of the higher-order methods for numerical simulation of three-phase flow for complex geometries and processes.

  11. The Cauchy method of residues

    CERN Document Server

    Mitrinović, Dragoslav S


    Volume 1, i. e. the monograph The Cauchy Method of Residues - Theory and Applications published by D. Reidel Publishing Company in 1984 is the only book that covers all known applications of the calculus of residues. They range from the theory of equations, theory of numbers, matrix analysis, evaluation of real definite integrals, summation of finite and infinite series, expansions of functions into infinite series and products, ordinary and partial differential equations, mathematical and theoretical physics, to the calculus of finite differences and difference equations. The appearance of Volume 1 was acknowledged by the mathematical community. Favourable reviews and many private communications encouraged the authors to continue their work, the result being the present book, Volume 2, a sequel to Volume 1. We mention that Volume 1 is a revised, extended and updated translation of the book Cauchyjev raeun ostataka sa primenama published in Serbian by Nau~na knjiga, Belgrade in 1978, whereas the greater part ...

  12. Determination of radon partition coefficients between water and different kinds of NAPLs for use in analysis of residual soil NAPLs

    Energy Technology Data Exchange (ETDEWEB)

    Bonfim, Sarah Andresa; Ferreira, Ângela Fortini Macedo, E-mail: [Universidade Federal de Migas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Franklin, Mariza Ramalho; Ferreira, Paulo Roberto Rocha [Instituto de Radioproteção e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Rocha, Zildete, E-mail: [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)


    Different studies indicate the applicability of natural radon as a tracer in the determination of contaminated environments by Non-Aqueous Phase Liquids (NAPLs). Such use being due to the non-homogeneous distribution of this element between water, air and NAPL. Thus, it is known that the concentration of radon in a given soil / aquifer and in a given area may indicate that such site is contaminated by NAPL. However, the simple measurement of radon concentration activity allows only a qualitative evaluation of the area contaminated in study. For a quantitative estimate of the NAPL saturation in the pore space, it is necessary to know the radon partition coefficients between the coexisting phases, considering the kind of NAPL present. The present study, the radon partitioning coefficients between air, water and diverse types of NAPL mixtures, such as gasoline, diesel fuel, alcohol, kerosene and olive oil was measured. In a closed system, was applied an analytical method based on the distribution of the radon between the present phases with the use of a system of Flow Injection Analysis (FIA). The measurement of the specific activity of radon was performed by using an AlphaGUARD monitor. It is observed that, in the presence of NAPL, the concentration of radon in water and air is significantly lower than in its absence, indicating a negative correlation and allowing the evaluation of the contamination of the area by NAPL. (author)

  13. A new approach of the understanding of sulfur dioxide reduction in non-aqueous solvent; Une nouvelle approche de la comprehension de la reduction du dioxyde de soufre en solvant non aqueux

    Energy Technology Data Exchange (ETDEWEB)

    Potteau, E.; Levillain, E.; Lelieur, J.P. [Laboratoire de Spectrochimie Infrarouge et Raman (LASIR, UPR 2631 CNRS) Haute Etudes Industrielles (HEI), 59 - Lille (France)


    The study of SO{sub 2} reduction in non-aqueous solvent can help to understand the functioning of Li/SO{sub 2} batteries and to find a simpler way for the synthesis of Li{sub 2}S{sub 2}O{sub 4} dithionite. This paper presents the results of electrochemical studies (cycle volt-amperometry in semi-infinite and thin film diffusion conditions, visible spectro-electrochemistry) and spectroscopic studies (UV, visible and RPE) performed on SO{sub 2} solutions. A mechanism of SO{sub 2} reduction is proposed and discussed. (J.S.) 18 refs.

  14. Characterisation and management of concrete grinding residuals. (United States)

    Kluge, Matt; Gupta, Nautasha; Watts, Ben; Chadik, Paul A; Ferraro, Christopher; Townsend, Timothy G


    Concrete grinding residue is the waste product resulting from the grinding, cutting, and resurfacing of concrete pavement. Potential beneficial applications for concrete grinding residue include use as a soil amendment and as a construction material, including as an additive to Portland cement concrete. Concrete grinding residue exhibits a high pH, and though not hazardous, it is sufficiently elevated that precautions need to be taken around aquatic ecosystems. Best management practices and state regulations focus on reducing the impact on such aquatic environment. Heavy metals are present in concrete grinding residue, but concentrations are of the same magnitude as typically recycled concrete residuals. The chemical composition of concrete grinding residue makes it a useful product for some soil amendment purposes at appropriate land application rates. The presence of unreacted concrete in concrete grinding residue was examined for potential use as partial replacement of cement in new concrete. Testing of Florida concrete grinding residue revealed no dramatic reactivity or improvement in mortar strength.

  15. Polychlorinated Biphenyls (PCB) Residue Effects Database (United States)

    U.S. Environmental Protection Agency — The PCB Residue Effects (PCBRes) Database was developed to assist scientists and risk assessors in correlating PCB and dioxin-like compound residues with toxic...

  16. Interpretation on Recycling Plastics from Shredder Residue (United States)

    EPA is considering an interpretation of its regulations that would generally allow for recycling of plastic separated from shredder residue under the conditions described in the Voluntary Procedures for Recycling Plastics from Shredder Residue.

  17. Impact of microwave pre-treatment on the batch anaerobic digestion of two-phase olive mill solid residue: a kinetic approach; Impacto del pretratamiento con microondas sobre la digestión anaerobia en régimen discontinuo de residuos sólidos de almazaras de dos fases: un enfoque cinético

    Energy Technology Data Exchange (ETDEWEB)

    Rincon, B.; Gonzalez de Canales, M.; Martin, A.; Borja, R.


    The effect of a microwave (MW) pre-treatment on two-phase olive mill solid residue (OMSR) or alperujo with a view to enhancing its anaerobic digestibility was studied. The MW pre-treatment was carried out at a power of 800 W and at a targeted temperature of 50 °C using different heating rates and holding times. The following specific energies were applied: 4377 kJ·kg TS−1 (MW1), 4830 kJ·kg TS−1 (MW2), 7170 kJ·kg TS−1 (MW3) and 7660 kJ·kg TS−1 (MW4). The maximum methane yield, 395±1 mL CH4·g VSadded−1, was obtained for MW4. The effect of the pre-treatment on the kinetics of the process was also studied. The methane production curves generated during the batch tests showed a first exponential stage and a second sigmoidal stage for all the cases studied. In the first stage, the kinetic constant for the pre-treatment MW1 was 54.8% higher than that obtained for untreated OMSR. [Spanish] El efecto del pretratamiento con microondas (MW) sobre el residuo semisólido procedente de la elaboración del aceite de oliva por el sistema de dos fases o alperujo fue estudiado con el objeto de aumentar su digestibilidad anaerobia. El pretratamiento fue llevado a cabo a una potencia de 800W y a una temperatura de 50 °C empleándose distintas velocidades de calentamiento así como diferentes tiempos de espera para obtener dichas condiciones. Las siguientes energías específicas fueron aplicadas: 4377 kJ·kg TS−1 (MW1), 4830 kJ·kg TS−1 (MW2), 7170 kJ·kg TS−1 (MW3) y 7660 kJ·kg TS−1 (MW4). El máximo rendimiento 395±1 mL CH4·g SVañadidos −1 se obtuvo para MW4. El efecto del pretratamiento en la cinética del proceso también fue estudiado. Las curvas de producción de metano durante los ensayos mostraron una etapa exponencial y una sigmoidal en todos los casos. En la primera etapa, la constante cinética para MW1 fue 54.8% mayor que la obtenida para el alperujo sin pretratar.

  18. Microchip Non-Aqueous Capillary Electrophoresis (MicronNACE) Method to Analyze Long-Chain Primary Amines (United States)

    Willis, Peter A.; Mora, Maria; Cable, Morgan L.; Stockton, Amanda M.


    A protocol was developed as a first step in analyzing the complex organic aerosols present on Saturn's moon Titan, as well as the analogues of these aerosols (tholins) made on Earth. Labeling of primary amines using Pacific Blue succinimidyl ester is effected in ethanol with 25 mM triethylamine to maintain basic conditions. This reaction is allowed to equilibrate for at least one hour. Separation of the labeled primary amines is performed in ethanol with 1.05 M acetic acid, and 50 mM ammonium acetate in a commercial two-layer glass device with a standard crossmicrochannel measuring 50 microns wide by 20 microns deep. Injection potentials are optimized at 2 kV from the sample (negative) to the waste well (positive), with slight bias applied to the other two wells ( 0.4 and 0.8 V) to pinch the injection plug for the 30-s injection. Separation is performed at a potential of 5 kV along the channel, which has an effective separation distance of 7 cm. The use of ethanol in this method means that long-chain primary amines can be dissolved. Due to the low pH of the separation buffer, electro-osmotic flow (EOF) is minimized to allow for separation of both short-chain and longchain amines. As the freezing point of ethanol is much lower than water, this protocol can perform separations at temperatures lower than 0 C, which would not be possible in aqueous phase. This is of particular importance when considering in situ sampling of Titan aerosols, where unnecessary heating of the sample (even to room temperature) would lead to decomposition or unpredictable side reactions, which would make it difficult to characterize the sample appropriately.

  19. Residual Analysis of Generalized Autoregressive Integrated Moving ...

    African Journals Online (AJOL)

    In this study, analysis of residuals of generalized autoregressive integrated moving average bilinear time series model was considered. The adequacy of this model was based on testing the estimated residuals for whiteness. Jarque-Bera statistic and squared-residual autocorrelations were used to test the estimated ...

  20. 9 CFR 311.39 - Biological residues. (United States)


    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Biological residues. 311.39 Section... Biological residues. Carcasses, organs, or other parts of carcasses of livestock shall be condemned if it is determined that they are adulterated because of the presence of any biological residues. ...

  1. Cycling of grain legume residue nitrogen

    DEFF Research Database (Denmark)

    Jensen, E.S.


    Symbiotic nitrogen fixation by legumes is the main input of nitrogen in ecological agriculture. The cycling of N-15-labelled mature pea (Pisum sativum L.) residues was studied during three years in small field plots and lysimeters. The residual organic labelled N declined rapidly during the initial...... management methods in order to conserve grain legume residue N sources within the soil-plant system....

  2. Neutron residual stress measurements in linepipe (United States)

    Law, Michael; Gnaëpel-Herold, Thomas; Luzin, Vladimir; Bowie, Graham


    Residual stresses in gas pipelines are generated by manufacturing and construction processes and may affect the subsequent pipe integrity. In the present work, the residual stresses in eight samples of linepipe were measured by neutron diffraction. Residual stresses changed with some coating processes. This has special implications in understanding and mitigating stress corrosion cracking, a major safety and economic problem in some gas pipelines.

  3. Neutron residual stress measurements in linepipe

    International Nuclear Information System (INIS)

    Law, Michael; Gnaepel-Herold, Thomas; Luzin, Vladimir; Bowie, Graham


    Residual stresses in gas pipelines are generated by manufacturing and construction processes and may affect the subsequent pipe integrity. In the present work, the residual stresses in eight samples of linepipe were measured by neutron diffraction. Residual stresses changed with some coating processes. This has special implications in understanding and mitigating stress corrosion cracking, a major safety and economic problem in some gas pipelines

  4. Glycogen is large molecules wherein Glucose residues

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Glycogen is large molecules wherein Glucose residues. Glycogen is large molecules wherein Glucose residues. linked by α-(1- 4) glycosidic bonds into chains and chains. branch via α-(1- 6) linkage. Branching points are about every fourth residue – allows. glucose ...

  5. Phase partitioning modeling of ethanol, isopropanol, and methanol with BTEX compounds in water

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kenneth Y. [Department of Civil and Environmental Engineering, University of Massachusetts Lowell, 1 University Avenue, Lowell, MA 01854 (United States)], E-mail:


    This study investigates the equilibrium phase partitioning behavior of ethanol, isopropanol, and methanol in a two-phase liquid-liquid system consisting of water and an individual BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) compound. A previously developed computer program is enhanced to generate ternary phase diagrams for analysis of each three-component cosolvent-nonaqueous phase liquid (NAPL)-water mixture combination. The required activity coefficients are estimated using the UNIFAC (Universal Quasichemical Functional group Activity Coefficient) model. The UNIFAC-derived ternary phase diagrams generally show good agreement against published experimental data, and similar phase partitioning behavior is observed for every BTEX compound in the presence of the same cosolvent. Furthermore, a set of laboratory experiments is conducted to determine the maximum single-phase water content for every mixture combination considered in this study where the volume composition of the cosolvent and the NAPL components is a blend of 85% alcohol and 15% BTEX compound. Comparison of experimentally-derived maximum single-phase water contents against UNIFAC-derived results shows good agreement for mixtures containing ethanol and methanol, but relatively poor agreement for mixtures containing isopropanol. - As a high-alcohol content fuel blend migrates through the subsurface and encounters water, phase partitioning of the mixture plays a critical role in the distribution and spreading of the pollutants.

  6. High internal phase emulsions (HIPEs) and polymerised HIPEs (PolyHIPEs)

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, Neil R


    High internal phase emulsions (HIPEs) possess an internal phase volume ratio ({phi}) greater than 0.74. Novel non-aqueous HIPEs can be obtained from a non-polar organic liquid, such as petroleum ether, dispersed in a highly polar medium, such as formamide or dimethylsulfoxide. The system is stabilised with block copolymer surfactants of suitable HLB number. Polymerisation of a HIPE continuous phase leads to a highly porous monolithic material known as PolyHIPE. These polymers often have a completely open-cellular structure. The mechanism for the formation of this morphology was elucidated by performing scanning electron microscopy (SEM) on frozen HIPE samples at various stages of polymerisation. The point of transition from emulsion to open-cell polymer was found to coincide with the gel-point of the system, implying that the interconnected structure forms as a result of contraction of the continuous phase thin films on polymerisation. Novel PolyHIPE materials have been prepared by chemical modification of crosslinked polystyrene polymers. Sulfonation, nitration and bromination of monolithic samples to moderate levels and reasonable uniformity have been performed with mild reagents in homogeneous reaction conditions. In addition, crosslinked poly(phenyl methacrylate) (PPMA) PolyHIPE materials have been synthesised and chemically modified with tris(hydroxymethyl)-aminomethane (TRIS) under basic conditions, again to a moderate degree. Elastomeric PolyHIPE materials were prepared by copolymerisation of styrene and divinyl benzene (DVB) with 2-ethylhexyl (meth)acrylate. The variation of their glass transition temperatures (Tg) with composition was found to be non-linear. This is proposed to be due to both intra- and intermolecular interactions between polymer chains. Novel PolyHIPE polymers with enhanced thermal properties have been obtained by copolymerisation of an end-capped aryl ether sulfone oligomer with a number of monomers in a non-aqueous HIPE system

  7. Modification and re-validation of the ethyl acetate-based multi-residue method for pesticides in produce

    NARCIS (Netherlands)

    Mol, J.G.J.; Rooseboom, A.; Dam, van R.; Roding, M.; Arondeus, K.; Sunarto, S.


    The ethyl acetate-based multi-residue method for determination of pesticide residues in produce has been modified for gas chromatographic (GC) analysis by implementation of dispersive solid-phase extraction (using primary¿secondary amine and graphitized carbon black) and large-volume (20 ¿L)

  8. Modification and re-validation of the ethyl acetate-based multi-residue method for pesticides in produce

    NARCIS (Netherlands)

    Mol, H.G.J.; Rooseboom, A.; Dam, R. van; Roding, M.; Arondeus, K.; Sunarto, S.


    The ethyl acetate-based multi-residue method for determination of pesticide residues in produce has been modified for gas chromatographic (GC) analysis by implementation of dispersive solid-phase extraction (using primary-secondary amine and graphitized carbon black) and large-volume (20 μL)

  9. Natural radioactivity in petroleum residues

    International Nuclear Information System (INIS)

    Gazineu, M.H.P.; Gazineu, M.H.P.; Hazin, C.A.; Hazin, C.A.


    The oil extraction and production industry generates several types of solid and liquid wastes. Scales, sludge and water are typical residues that can be found in such facilities and that can be contaminated with Naturally Occurring Radioactive Material (N.O.R.M.). As a result of oil processing, the natural radionuclides can be concentrated in such residues, forming the so called Technologically Enhanced Naturally Occurring Radioactive Material, or T.E.N.O.R.M.. Most of the radionuclides that appear in oil and gas streams belong to the 238 U and 232 Th natural series, besides 40 K. The present work was developed to determine the radionuclide content of scales and sludge generated during oil extraction and production operations. Emphasis was given to the quantification of 226 Ra, 228 Ra and 40 K since these radionuclides,are responsible for most of the external exposure in such facilities. Samples were taken from the P.E.T.R.O.B.R.A.S. unity in the State of Sergipe, in Northeastern Brazil. They were collected directly from the inner surface of water pipes and storage tanks, or from barrels stored in the waste storage area of the E and P unit. The activity concentrations for 226 Ra, 228 Ra and 40 K were determined by using an HP Ge gamma spectrometric system. The results showed concentrations ranging from 42.7 to 2,110.0 kBq/kg for 226 Ra, 40.5 to 1,550.0 kBq/kg for 228 Ra, and 20.6 to 186.6 kBq/kg for 40 K. The results highlight the importance of determining the activity concentration of those radionuclides in oil residues before deciding whether they should be stored or discarded to the environment. (authors)

  10. Natural radioactivity in petroleum residues

    Energy Technology Data Exchange (ETDEWEB)

    Gazineu, M.H.P. [UNICAP, Dept. de Quimica, Recife (Brazil); Gazineu, M.H.P.; Hazin, C.A. [UFPE, Dept. de Energia Nuclear, Recife (Brazil); Hazin, C.A. [Centro Regional de Ciencias Nucleares/ CNEN, Recife (Brazil)


    The oil extraction and production industry generates several types of solid and liquid wastes. Scales, sludge and water are typical residues that can be found in such facilities and that can be contaminated with Naturally Occurring Radioactive Material (N.O.R.M.). As a result of oil processing, the natural radionuclides can be concentrated in such residues, forming the so called Technologically Enhanced Naturally Occurring Radioactive Material, or T.E.N.O.R.M.. Most of the radionuclides that appear in oil and gas streams belong to the {sup 238}U and {sup 232}Th natural series, besides 40 K. The present work was developed to determine the radionuclide content of scales and sludge generated during oil extraction and production operations. Emphasis was given to the quantification of {sup 226}Ra, {sup 228}Ra and 40 K since these radionuclides,are responsible for most of the external exposure in such facilities. Samples were taken from the P.E.T.R.O.B.R.A.S. unity in the State of Sergipe, in Northeastern Brazil. They were collected directly from the inner surface of water pipes and storage tanks, or from barrels stored in the waste storage area of the E and P unit. The activity concentrations for {sup 226}Ra, {sup 228}Ra and 40 K were determined by using an HP Ge gamma spectrometric system. The results showed concentrations ranging from 42.7 to 2,110.0 kBq/kg for {sup 226}Ra, 40.5 to 1,550.0 kBq/kg for {sup 228}Ra, and 20.6 to 186.6 kBq/kg for 40 K. The results highlight the importance of determining the activity concentration of those radionuclides in oil residues before deciding whether they should be stored or discarded to the environment. (authors)

  11. Residual Liquefaction under Standing Waves

    DEFF Research Database (Denmark)

    Kirca, V.S. Ozgur; Sumer, B. Mutlu; Fredsøe, Jørgen


    This paper summarizes the results of an experimental study which deals with the residual liquefaction of seabed under standing waves. It is shown that the seabed liquefaction under standing waves, although qualitatively similar, exhibits features different from that caused by progressive waves....... The experimental results show that the buildup of pore-water pressure and the resulting liquefaction first starts at the nodal section and spreads towards the antinodal section. The number of waves to cause liquefaction at the nodal section appears to be equal to that experienced in progressive waves for the same...

  12. Process to recycle shredder residue (United States)

    Jody, Bassam J.; Daniels, Edward J.; Bonsignore, Patrick V.


    A system and process for recycling shredder residue, in which separating any polyurethane foam materials are first separated. Then separate a fines fraction of less than about 1/4 inch leaving a plastics-rich fraction. Thereafter, the plastics rich fraction is sequentially contacted with a series of solvents beginning with one or more of hexane or an alcohol to remove automotive fluids; acetone to remove ABS; one or more of EDC, THF or a ketone having a boiling point of not greater than about C. to remove PVC; and one or more of xylene or toluene to remove polypropylene and polyethylene. The solvents are recovered and recycled.

  13. Residual replacement strategies for Krylov subspace iterative methods for the convergence of true residuals

    NARCIS (Netherlands)

    Vorst, H.A. van der; Ye, Q.


    In this paper, a strategy is proposed for alternative computations of the residual vectors in Krylov subspace methods, which improves the agreement of the computed residuals and the true residuals to the level of O(u)kAkkxk. Building on earlier ideas on residual replacement and on insights in

  14. Residual stress measurements of welded stainless steel 304 plate using the HANARO residual stress instrument

    International Nuclear Information System (INIS)

    Mun, M. K.; Lee, C. H.; Em, V. T.


    In order to nondestructively measure in-depth residual stress distribution of the metallic materials, it is unique method to use neutron diffraction. In this paper the principles of residual stress measurements by neutron diffraction is described. The residual stress distribution of welded strainless steeel 304 plate using te HANARO residual stress instrument is also described

  15. 40 CFR 721.4500 - Isopropylamine distillation residues and ethylamine distillation residues. (United States)


    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Isopropylamine distillation residues and ethylamine distillation residues. 721.4500 Section 721.4500 Protection of Environment... residues and ethylamine distillation residues. (a) Chemical substances and significant new use subject to...

  16. Residual analysis for spatial point processes

    DEFF Research Database (Denmark)

    Baddeley, A.; Turner, R.; Møller, Jesper

    process. Residuals are ascribed to locations in the empty background, as well as to data points of the point pattern. We obtain variance formulae, and study standardised residuals. There is also an analogy between our spatial residuals and the usual residuals for (non-spatial) generalised linear models...... or covariate effects. Q-Q plots of the residuals are effective in diagnosing interpoint interaction. Some existing ad hoc statistics of point patterns (quadrat counts, scan statistic, kernel smoothed intensity, Berman's diagnostic) are recovered as special cases....

  17. Cycling of grain legume residue nitrogen

    DEFF Research Database (Denmark)

    Jensen, E.S.


    weeks of decomposition, due to high rates of residue N net mineralization and subsequent leaching and denitrification losses of N. Lysimeter experiments showed that pea residues may reduce leaching losses of N, probably due to their effect on the mineralization-immobilizalion turnover of N...... and denitrification. Winter barley succeeding field pea recovered 13% of the incorporated pea residue N by early December; the recovery was found to be 15% at maturity in July. A spring-sown crop of barley recovered less than half the amount of pea residue N recovered by winter barley. The residue N-use efficiencies...

  18. Injection, flow, and mixing of CO2 in porous media with residual gas.

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, C.M.; Doughty, C.A.


    Geologic structures associated with depleted natural gas reservoirs are desirable targets for geologic carbon sequestration (GCS) as evidenced by numerous pilot and industrial-scale GCS projects in these environments world-wide. One feature of these GCS targets that may affect injection is the presence of residual CH{sub 4}. It is well known that CH{sub 4} drastically alters supercritical CO{sub 2} density and viscosity. Furthermore, residual gas of any kind affects the relative permeability of the liquid and gas phases, with relative permeability of the gas phase strongly dependent on the time-history of imbibition or drainage, i.e., dependent on hysteretic relative permeability. In this study, the effects of residual CH{sub 4} on supercritical CO{sub 2} injection were investigated by numerical simulation in an idealized one-dimensional system under three scenarios: (1) with no residual gas; (2) with residual supercritical CO{sub 2}; and (3) with residual CH{sub 4}. We further compare results of simulations that use non-hysteretic and hysteretic relative permeability functions. The primary effect of residual gas is to decrease injectivity by decreasing liquid-phase relative permeability. Secondary effects arise from injected gas effectively incorporating residual gas and thereby extending the mobile gas plume relative to cases with no residual gas. Third-order effects arise from gas mixing and associated compositional effects on density that effectively create a larger plume per unit mass. Non-hysteretic models of relative permeability can be used to approximate some parts of the behavior of the system, but fully hysteretic formulations are needed to accurately model the entire system.

  19. Residual stress measurements in polycrystalline graphite with micro-Raman spectroscopy

    International Nuclear Information System (INIS)

    Krishna, Ram; Jones, Abbie N.; Edge, Ruth; Marsden, Barry J.


    Micro-Raman microscopy technique is applied to evaluate unevenly distributed residual stresses in the various constituents of polygranular reactor grades graphite. The wavenumber based Raman shift (cm −1 ) corresponds to the local residual stress and measurements of stress dependent first order Raman spectra in graphite have enabled localized residual stress values to be determined. The bulk polygranular graphite of reactor grades – Gilsocarbon, NBG-18 and PGA – are examined to illustrate the residual stress variations in their constituents. Binder phase and filler particles have shown to be under compressive and tensile stresses, respectively. Among the studied graphite grades, the binder phase in Gilsocarbon has the highest residual stress and NBG-18 has the lowest value. Filler particles in Gilsocarbon have the highest residual stress and PGA showed the lowest, this is most likely due to the morphology of the coke particles used in the manufacturing and applied processing techniques for fabrications. Stresses have also been evaluated along the peripheral of pores and at the tips of the cracks. Cracks in filler and binder phases have shown mixed behaviour, compressive as well as tensile, whereas pores in binder and filler particles have shown compressive behaviour. The stresses in these graphitic constituents are of the order of MPa. Non-destructive analyses presented in this study make the current state-of-the-art technique a powerful method for the study of stress variations near the graphite surface and are expected to increase its use further in property determination analysis of low to highly fluence irradiated graphite samples from the material test reactors. - Highlights: • Micro-Raman spectroscopy can measure significantly small residual stresses. • Gilsocarbon, NBG-18 and PGA graphite were evaluated for residual stresses. • Residual stresses in the constituents of graphite were evaluated. • Binder and filler particles are often found under

  20. Moon Phases (United States)

    Riddle, Bob


    When teaching Moon phases, the focus seems to be on the sequence of Moon phases and, in some grade levels, how Moon phases occur. Either focus can sometimes be a challenge, especially without the use of models and observations of the Moon. In this month's column, the author describes some of the lessons that he uses to teach the phases of the Moon…

  1. Visualization of residual organic liquid trapped in aquifers

    International Nuclear Information System (INIS)

    Conrad, S.H.; Wilson, J.L.; Mason, W.R.; Peplinski, W.J.


    Organic liquids that are essentially immiscible with water migrate through the subsurface under the influence of capillary, viscous, and buoyancy forces. These liquids originate from the improper disposal of hazardous wastes, and the spills and leaks of petroleum hydrocarbons and solvents. The flow visualization experiments described in this study examined the migration of organic liquids through the saturated zone of aquifers, with a primary focus on the behavior of the residual organic liquid saturation, referring to that portion of the organic liquid that is trapped by capillary forces. Etched glass micromodels were used to visually observe dynamic multiphase displacement processes in pore networks. The resulting fluid distributions were photographed. Pore and blob casts were produced by a technique in which an organic liquid was solidified in place within a sand column at the conclusion of a displacement. The columns were sectioned and examined under optical and scanning electron microscopes. Photomicrographs of these sections show the morphology of the organic phase and its location within the sand matrix. The photographs from both experimental techniques reveal that in the saturated zone large amounts of residual organic liquid are trapped as isolated blobs of microscopic size. The size, shape, and spatial distribution of these blobs of residual organic liquid affect the dissolution of organic liquid into the water phase and the biotransformation of organic components. These processes are of concern for the prediction of pollution migration and the design of aquifer remediation schemes

  2. Monitoring antibiotic residues in honey

    Directory of Open Access Journals (Sweden)

    Monica Cristina Cara,


    Full Text Available Next to the beta-lactam antibiotics in veterinary medicine, streptomycin is one of the mostly used antibiotics. High concentration of streptomycin could lead to ototoxic and nephrotoxic effects. Low concentration – as found in food – may cause allergies, destroy the intestinal flora and favor immunity to some pathogenic microorganisms. In 1948 chlortetracycline was isolated by Duggan as a metabolite and this was the first antibiotic substance of the group of tetracyclines. In the present paper there are presented the monitoring of the antibiotic residues in honey from Timis County. The residues of tetracycline and streptomycin in honey were determined by the method ELISA – a quantitative method of detection. The microtitre wells are coated with tetracycline and anti-streptomycin antibodies. Free antibiotic and immobilized antibiotic compete with the added antibiotic antibody (competitive immunoassay reaction. Any unbound antibody is then removed in a washing step. Bound conjugate enzymes convert the colorless chromogen into a blue product. The addition ofthe stop reagent leads to a color change from blue to yellow. The measurement is made photometrically at 450 nm. The absorption is inversely proportional to the antibiotic concentration in the sample.

  3. Residual Stresses In 3013 Containers

    International Nuclear Information System (INIS)

    Mickalonis, J.; Dunn, K.


    The DOE Complex is packaging plutonium-bearing materials for storage and eventual disposition or disposal. The materials are handled according to the DOE-STD-3013 which outlines general requirements for stabilization, packaging and long-term storage. The storage vessels for the plutonium-bearing materials are termed 3013 containers. Stress corrosion cracking has been identified as a potential container degradation mode and this work determined that the residual stresses in the containers are sufficient to support such cracking. Sections of the 3013 outer, inner, and convenience containers, in both the as-fabricated condition and the closure welded condition, were evaluated per ASTM standard G-36. The standard requires exposure to a boiling magnesium chloride solution, which is an aggressive testing solution. Tests in a less aggressive 40% calcium chloride solution were also conducted. These tests were used to reveal the relative stress corrosion cracking susceptibility of the as fabricated 3013 containers. Significant cracking was observed in all containers in areas near welds and transitions in the container diameter. Stress corrosion cracks developed in both the lid and the body of gas tungsten arc welded and laser closure welded containers. The development of stress corrosion cracks in the as-fabricated and in the closure welded container samples demonstrates that the residual stresses in the 3013 containers are sufficient to support stress corrosion cracking if the environmental conditions inside the containers do not preclude the cracking process.

  4. Residual Fragments after Percutaneous Nephrolithotomy

    Directory of Open Access Journals (Sweden)

    Kaan Özdedeli


    Full Text Available Clinically insignificant residual fragments (CIRFs are described as asymptomatic, noninfectious and nonobstructive stone fragments (≤4 mm remaining in the urinary system after the last session of any intervention (ESWL, URS or PCNL for urinary stones. Their insignificance is questionable since CIRFs could eventually become significant, as their presence may result in recurrent stone growth and they may cause pain and infection due to urinary obstruction. They may become the source of persistent infections and a significant portion of the patients will have a stone-related event, requiring auxilliary interventions. CT seems to be the ultimate choice of assessment. Although there is no concensus about the timing, recent data suggests that it may be performed one month after the procedure. However, imaging can be done in the immediate postoperative period, if there are no tubes blurring the assessment. There is some evidence indicating that selective medical therapy may have an impact on decreasing stone formation rates. Retrograde intrarenal surgery, with its minimally invasive nature, seems to be the best way to deal with residual fragments.

  5. On the reliability of neutron diffraction for residual stress measurement in cold-drawn steels

    International Nuclear Information System (INIS)

    Ruiz-Hervias, J; Atienza, J M; Mompean, F; Hofmann, M


    Residual strains were measured in the ferrite phase of pearlitic steel rods along the radial, axial and hoop directions. Two samples with different initial diameters were subjected to one drawing pass (using same drawing parameters) with 20% section reduction and measured in two different neutron diffraction instruments. The results show that the residual strain state is very similar in both cases, regardless of the diameter of the initial rod. This means that the final residual strain-stress state is unique and it is related to the cold-drawing process parameters. In addition, the results show the reliability of strain scanning with different neutron instruments and experimental conditions.

  6. Interaction of amines with native aluminium oxide layers in non-aqueous environment: Application to the understanding of the formation of epoxy-amine/metal interphases

    Energy Technology Data Exchange (ETDEWEB)

    Mercier, D.; Rouchaud, J.-C. [Centre d' Etudes de Chimie Metallurgique, CNRS, 15 rue Georges Urbain, 94407 Vitry Cedex (France); Barthes-Labrousse, M.-G. [Centre d' Etudes de Chimie Metallurgique, CNRS, 15 rue Georges Urbain, 94407 Vitry Cedex (France)], E-mail:


    Interaction of propylamine (PA), 1,2-diaminoethane (DAE) or 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophorone diamine, IPDA) with native aluminium oxide layers in non-aqueous environment has been studied using time-resolved inductively coupled plasma optical emission spectroscopy (ICP-OES) and X-ray photoelectron spectroscopy (XPS). The formation of several surface complexes has been evidenced. Monodentate and bidentate metal-bond surface complexes (MBSC) result from interactions between the amine terminations of the molecule and aluminium cations by donation of the N lone electron pair to the metal ion (Lewis-like mechanism leading to O-Al...N bonds). Monodentate and bidentate hydrogen-bond surface complexes (HBSC) are due to interaction of the amino group with surface hydroxyl groups by protonation of the amine termination (Bronsted-like mechanism leading to the formation of Al-OH...N bonds) or interaction with carbonaceous contamination (C{sub x}O{sub y}H{sub z}...N bonds). Diamines can also form mixed complexes with one amino group forming an O-Al...N bond and the other group forming an Al-OH...N or C{sub x}O{sub y}H{sub z}...N bond. Al-OH...N and C{sub x}O{sub y}H{sub z}...N bonds are less stable under vacuum than O-Al...N bonds, leading to partial desorption of the DAE molecules in vacuum and modification of the interaction modes. Only DAE and IPDA can lead to partial dissolution of the aluminium native (hydr)oxide films. A detailed mechanism of dissolution has been proposed based on the formation of mononuclear bidentate (chelate) MBSC by ligand exchange between the terminal {eta}{sup 1}-OH and bridged {mu}{sub 2}-OH surface sites and the amino terminations of the molecule. The detachment of this complex from the surface is likely to be the precursor step to the formation of the interphase in epoxy-amine/metal systems.

  7. Contaminant Leach Testing of Hanford Tank 241-C-104 Residual Waste

    Energy Technology Data Exchange (ETDEWEB)

    Cantrell, Kirk J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Snyder, Michelle M.V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Guohui [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Buck, Edgar C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    Leach testing of Tank C-104 residual waste was completed using batch and column experiments. Tank C-104 residual waste contains exceptionally high concentrations of uranium (i.e., as high as 115 mg/g or 11.5 wt.%). This study was conducted to provide data to develop contaminant release models for Tank C-104 residual waste and Tank C-104 residual waste that has been treated with lime to transform uranium in the waste to a highly insoluble calcium uranate (CaUO4) or similar phase. Three column leaching cases were investigated. In the first case, C-104 residual waste was leached with deionized water. In the second case, crushed grout was added to the column so that deionized water contacted the grout prior to contacting the waste. In the third case, lime was mixed in with the grout. Results of the column experiments demonstrate that addition of lime dramatically reduces the leachability of uranium from Tank C-104 residual waste. Initial indications suggest that CaUO4 or a similar highly insoluble calcium rich uranium phase forms as a result of the lime addition. Additional work is needed to definitively identify the uranium phases that occur in the as received waste and the waste after the lime treatment.

  8. Phase partitioning modeling of ethanol, isopropanol, and methanol with BTEX compounds in water. (United States)

    Lee, Kenneth Y


    This study investigates the equilibrium phase partitioning behavior of ethanol, isopropanol, and methanol in a two-phase liquid-liquid system consisting of water and an individual BTEX (Benzene, Toluene, Ethylbenzene, and Xylenes) compound. A previously developed computer program is enhanced to generate ternary phase diagrams for analysis of each three-component cosolvent-nonaqueous phase liquid (NAPL)-water mixture combination. The required activity coefficients are estimated using the UNIFAC (Universal Quasichemical Functional group Activity Coefficient) model. The UNIFAC-derived ternary phase diagrams generally show good agreement against published experimental data, and similar phase partitioning behavior is observed for every BTEX compound in the presence of the same cosolvent. Furthermore, a set of laboratory experiments is conducted to determine the maximum single-phase water content for every mixture combination considered in this study where the volume composition of the cosolvent and the NAPL components is a blend of 85% alcohol and 15% BTEX compound. Comparison of experimentally-derived maximum single-phase water contents against UNIFAC-derived results shows good agreement for mixtures containing ethanol and methanol, but relatively poor agreement for mixtures containing isopropanol.

  9. Phase Field (United States)

    Koyama, Toshiyuki

    The term phase field has recently become known across many fields of materials science. The meaning of phase field is the spatial and temporal order parameter field defined in a continuum-diffused interface model. By using the phase field order parameters, many types of complex microstructure changes observed in materials science are described effectively. This methodology has been referred to as the phase field method, phase field simulation, phase field modeling, phase field approach, etc. In this chapter, the basic concept and theoretical background for the phase field approach is explained in Sects. 21.1 and 21.2. The overview of recent applications of the phase field method is demonstrated in Sects. 21.3 to 21.6.

  10. Unwrapped phase inversion with an exponential damping

    KAUST Repository

    Choi, Yun Seok


    Full-waveform inversion (FWI) suffers from the phase wrapping (cycle skipping) problem when the frequency of data is not low enough. Unless we obtain a good initial velocity model, the phase wrapping problem in FWI causes a result corresponding to a local minimum, usually far away from the true solution, especially at depth. Thus, we have developed an inversion algorithm based on a space-domain unwrapped phase, and we also used exponential damping to mitigate the nonlinearity associated with the reflections. We construct the 2D phase residual map, which usually contains the wrapping discontinuities, especially if the model is complex and the frequency is high. We then unwrap the phase map and remove these cycle-based jumps. However, if the phase map has several residues, the unwrapping process becomes very complicated. We apply a strong exponential damping to the wavefield to eliminate much of the residues in the phase map, thus making the unwrapping process simple. We finally invert the unwrapped phases using the back-propagation algorithm to calculate the gradient. We progressively reduce the damping factor to obtain a high-resolution image. Numerical examples determined that the unwrapped phase inversion with a strong exponential damping generated convergent long-wavelength updates without low-frequency information. This model can be used as a good starting model for a subsequent inversion with a reduced damping, eventually leading to conventional waveform inversion.


    Directory of Open Access Journals (Sweden)

    J. A. Canova


    Full Text Available This study analyzes the effects of unserviceable tire residues on rendering mortar using lime and washed sand at a volumetric proportion of 1:6. The ripened composite was dried in an oven and combined with both cement at a volumetric proportion of 1:1.5:9 and rubber powder in proportional aggregate volumes of 6, 8, 10, and 12%. Water exudation was evaluated in the plastic state. Water absorption by capillarity, fresh shrinkage and mass loss, restrained shrinkage and mass loss, void content, flexural strength, and deformation energy under compression were evaluated in the hardened state. There was an improvement in the water exudation and water absorption by capillarity and drying shrinkage, as well as a reduction of the void content and flexural strength. The product studied significantly aided the water exudation from mortar and, capillary elevation in rendering.


    Directory of Open Access Journals (Sweden)

    José Aparecido Canova


    Full Text Available This study analyzes the effects of unserviceable tire residues on rendering mortar using lime and washed sand at a volumetric proportion of 1:6. The ripened composite was dried in an oven and combined with both cement at a volumetric proportion of 1:1.5:9 and rubber powder in proportional aggregate volumes of 6, 8, 10, and 12%. Water exudation was evaluated in the plastic state. Water absorption by capillarity, fresh shrinkage and mass loss, restrained shrinkage and mass loss, void content, flexural strength, and deformation energy under compression were evaluated in the hardened state. There was an improvement in the water exudation and water absorption by capillarity and drying shrinkage, as well as a reduction of the void content and flexural strength. The product studied significantly aided the water exudation from mortar and, capillary elevation in rendering.

  13. Landfill Mining of Shredder Residues

    DEFF Research Database (Denmark)

    Hansen, Jette Bjerre; Hyks, Jiri; Shabeer Ahmed, Nassera

    In Denmark, shredder residues (SR) are classified as hazardous waste and until January 2012 the all SR were landfilled. It is estimated that more than 1.8 million tons of SR have been landfilled in mono cells. This paper describes investigations conducted at two Danish landfills. SR were excavated...... from the landfills and size fractionated in order to recover potential resources such as metal and energy and to reduce the amounts of SR left for re-landfilling. Based on the results it is estimated that 60-70% of the SR excavated could be recovered in terms of materials or energy. Only a fraction...... with particle size less than 5 mm needs to be re-landfilled at least until suitable techniques are available for recovery of materials with small particle sizes....

  14. Synthesis of high specific active tritiated Leu-enkephalin in the leucine residue

    Energy Technology Data Exchange (ETDEWEB)

    Baba, S.; Hasegawa, H.; Shinohara, Y. (Tokyo Coll. of Pharmacy (Japan))


    Leu-enkephalin labelled with tritium in the Leu residue has been prepared. Synthesis of the precursor peptide, (4,5-dehydroLeu{sup 5}-)Leu-enkephalin, was carried out by solid phase synthesis using Fmoc amino acid derivatives. The peptide was tritiated catalytically yielding {sup 3}H-Leu-enkephalin with a specific radioactivity of 4.39 TBq/mmol. The distribution of tritium label was investigated by reversed-phase high performance liquid chromatography with a synchronized accumulating radioisotope detector following acidic and enzymatic hydrolysis, which confirmed that the tritium label was entirely located at the Leu residue. (author).

  15. Determination of ractopamine in animal hair: application to residue depletion in sheep and residue monitoring. (United States)

    Suo, Decheng; Zhao, Genlong; Wang, Ruiguo; Su, Xiaoou


    An ultra-performance liquid chromatography tandem mass spectrometry method to determine ractopamine (RAC) in hair samples from swine, sheep, and cattle was developed. The procedure to extract from incurred hair was optimized. The samples were extracted with 0.1mol/L HCl solution. The mixture was heated to 60°C in water bath for 4h. The extracts were purified by solid-phase extraction, dried under a stream of nitrogen, and then reconstituted in mobile phase for analysis, which was performed with a Waters BEH-C18 column. The limit of detection was 0.3ng/g, the limit of quantification was 1ng/g, the recoveries were between 87% and 105%, and the coefficient of variation was less than 15%. The depletion of RAC in hair was studied in healthy sheep after administration of RAC at 1000ng/g body weight for five consecutive days. The RAC residues were still detected with 82.5±7.2ng/g hair 27 days after drug administration. Five samples tested positive, in which the amount of RAC detected was 13-253ng/g from 569 hair samples collected from farms and slaughterhouses. These results show that animal hair is a suitable medium to monitor the illegal use of RAC in livestock production. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Detection of antibiotic residues in poultry meat. (United States)

    Sajid, Abdul; Kashif, Natasha; Kifayat, Nasira; Ahmad, Shabeer


    The antibiotic residues in poultry meat can pose certain hazards to human health among them are sensitivity to antibiotics, allergic reactions, mutation in cells, imbalance of intestinal micro biota and bacterial resistance to antibiotics. The purpose of the present paper was to detect antibiotic residue in poultry meat. During the present study a total of 80 poultry kidney and liver samples were collected and tested for detection of different antibiotic residues at different pH levels Eschericha coli at pH 6, 7 and Staphyloccocus aureus at pH 8 & 9. Out of 80 samples only 4 samples were positive for antibiotic residues. The highest concentrations of antibiotic residue found in these tissues were tetracycline (8%) followed by ampicilin (4%), streptomycine (2%) and aminoglycosides (1%) as compared to other antibiotics like sulfonamides, neomycine and gentamycine. It was concluded that these microorganism at these pH levels could be effectively used for detection of antibiotic residues in poultry meat.

  17. Distribution of residues and primitive roots

    Indian Academy of Sciences (India)

    Replacing the function f by g, we get the required estimate for N(p, N). D. Proof of Theorem 1.1. When p = 7, we clearly see that (1, 2) is a consecutive pair of quadratic residue modulo 7. Assume that p ≥ 11. If 10 is a quadratic residue modulo p, then we have (9, 10) as a consecutive pair of quadratic residues modulo p, ...

  18. Occurrence of pesticide non extractable residues in physical and chemical fractions from two natural soils. (United States)

    Andreou, K.; Jones, K.; Semple, K.


    Distribution of pesticide non extractable residues resulted from the incubation of two natural soils with each of the isoproturon, diazinon and cypermethrin pesticide was assessed in this study. Pesticide non extractable residues distribution in soil physical and chemical fractions is known to ultimately affect their fate. This study aimed to address the fate and behaviour of the non extractable residues in the context of their association with soil physical and chemical fractions with varying properties and characteristics. Non extractable residues were formed from incubation of each pesticide in the two natural soils over a period of 24 months. Soils containing the non extractable residues were fractionated into three solid phase fractions using a physical fractionation procedure as follows: Sediment (SED, >20 μm), (II) Microaggregate (MA, 20-2 μm) and (III) Colloid phase (COL, 2-0.05 μm). Each soil fraction was then fractionated into organic carbon chemical fractionations as follows: Fulvic acid (FA), Humic acid (HA) and Humin (HM). Significant amount of the pesticides was lost during the incubation period. Enrichment factors for the organic carbon and the 14C-pesticide residues were higher in the MA and COL fraction rather than the SED fraction. Greater association and enrichment of the fulvic acid fraction of the organic carbon in the soil was observed. Non extractable residues at the FA fraction showed to diminish while in the HA fraction were increased with decreasing the fraction size. An appreciable amount of non extractable residues were located in the HM fraction but this was less than the amount recovered in the humic substances. Long term fate of pesticide non extractable residues in the soil structural components is important in order to assess any risk associated with them.

  19. Artificial Neural Networks and Concentration Residual Augmented ...

    African Journals Online (AJOL)

    Artificial Neural Networks and Concentration Residual Augmented Classical Least Squares for the Simultaneous Determination of Diphenhydramine, Benzonatate, Guaifenesin and Phenylephrine in their Quaternary Mixture.


    DEFF Research Database (Denmark)

    Løkke, Hans


    Investigations have been carried out on residues of linuron and its breakdown products in carrots sprayed with Jinuron at 1, 2, or 4 kg a.i./ha, 0, 19, 28, 36 or 60 days after sowing (up to 57 days before harvesting). The extracted residues were separated into three fractions by liquid......,4-dichloroaniline and iodide ion, followed by gas chromatography with electron capture detector. Only 5-13% of the extract-able residues were breakdown products. Most of the detectable residue (87-95%) was identified as linuron. The relative proportions of linuron and breakdown products in carrots at the time...

  1. Electrolyte salts for nonaqueous electrolytes (United States)

    Amine, Khalil; Zhang, Zhengcheng; Chen, Zonghai


    Metal complex salts may be used in lithium ion batteries. Such metal complex salts not only perform as an electrolyte salt in a lithium ion batteries with high solubility and conductivity, but also can act as redox shuttles that provide overcharge protection of individual cells in a battery pack and/or as electrolyte additives to provide other mechanisms to provide overcharge protection to lithium ion batteries. The metal complex salts have at least one aromatic ring. The aromatic moiety may be reversibly oxidized/reduced at a potential slightly higher than the working potential of the positive electrode in the lithium ion battery. The metal complex salts may also be known as overcharge protection salts.

  2. Analysis of martensitic transformation and residual tension in an 304L stainless steel

    International Nuclear Information System (INIS)

    Alves, Juciane Maria


    The relationship between plastic deformation and the strain induced phase transformation, that provides a practical route to the development of new engineering materials with excellent mechanical properties, characterize the TRIP effect 'Transformation Induced Plasticity'. Among the stainless steels, the metastable 304 L austenitic steel is susceptible to transformation of austenite-martensite phase from tensile tests at room temperature by increments of plastic deformation. It is of great technological and scientific interest the knowledge of the evolution of phase transformation and residual stress from different levels and rates of plastic deformation imposed to the material. It is also important to evaluate the interference of metallographic preparation in quantitative analyzes of this steel. The main techniques used in this study consisted of X-rays diffraction and Ferritoscopy for the quantitation phase, and XRD to residual stress analysis also. As observed, the phase transformation quantification has not suffered significant influence of the metallographic preparation and evolved from increments of plastic deformation due to different stop charges and strain rates, leading to a further strengthening of the austenite matrix. The evaluation of residual stress resulting from the martensitic transformation was susceptible to the metallographic preparation and increased its value on comparison to sample without metallographic preparation. It was also observed that the residual stress decreased with the increase of the fraction of transformed martensite. (author)

  3. Phase transformations in engineering materials

    International Nuclear Information System (INIS)

    Bourke, M.A.M.; Lawson, A.C.; Dunand, D.C.


    Phase transformations in engineering materials are inevitably related to mechanical behavior and are often precursors to residual stress and distortion. Neutron scattering in general is a valuable tool for studying their effects, and pulsed neutrons are of special value, because of the inherently comprehensive crystallographic coverage they provide in each measurement. At the Manuel Lujan neutron scattering center several different research programs have addressed the relationships between phase transformation/mechanical behavior and residual strains. Three disparate examples are presented; (1) stress induced transformation in a NiTi shape memory alloy, (2) cryogenically induced transformation in a quenched 5180 steel, and (3) time resolved evolution of strain induced martensite in 304 stainless steel. In each case a brief description of the principle result will be discussed in the context of using neutrons for the measurement

  4. Isotopic Hg in an Allende carbon-rich residue (United States)

    Reed, G. W., Jr.; Jovanovic, S.


    A carbon-rich residue from Allende subjected to stepwise heating yielded two isotopically resolvable types of Hg: one with an (Hg-196)/(Hg-202) concentration ratio the same as terrestrial (monitor) Hg; the other enriched in Hg-196 relative to Hg-202 by about 60 percent. Hg with the 202 isotope enriched relative to 196, as is found in bulk Allende, was not observed. Whether the result of mass fractionation or nucleosynthesis, the distinct types of Hg entered different carrier phases and were not thermally mobilized since the accretion of the Allende parent body.

  5. Isotopic Hg in an Allende carbon-rich residue

    International Nuclear Information System (INIS)

    Reed, G.W. Jr.; Jovanovic, S.


    A carbon-rich residue from Allende subjected to stepwise heating yielded two isotopically resolvable types of Hg: one with an (Hg-196)/(Hg-202) concentration ratio the same as terrestrial (monitor) Hg; the other enriched in Hg-196 relative to Hg-202 by about 60 percent. Hg with the 202 isotope enriched relative to 196, as is found in bulk Allende, was not observed. Whether the result of mass fractionation or nucleosynthesis, the distinct types of Hg entered different carrier phases and were not thermally mobilized since the accretion of the Allende parent body. 9 refs

  6. Detailed monitoring of two biogas plants and mechanical solid-liquid separation of fermentation residues. (United States)

    Bauer, Alexander; Mayr, Herwig; Hopfner-Sixt, Katharina; Amon, Thomas


    The Austrian "green electricity act" (Okostromgesetz) has led to an increase in biogas power plant size and consequently to an increased use of biomass. A biogas power plant with a generating capacity of 500 kW(el) consumes up to 38,000 kg of biomass per day. 260 ha of cropland is required to produce this mass. The high water content of biomass necessitates a high transport volume for energy crops and fermentation residues. The transport and application of fermentation residues to farmland is the last step in this logistic chain. The use of fermentation residues as fertilizer closes the nutrient cycle and is a central element in the efficient use of biomass for power production. Treatment of fermentation residues by separation into liquid and solid phases may be a solution to the transport problem. This paper presents detailed results from the monitoring of two biogas plants and from the analysis of the separation of fermentation residues. Furthermore, two different separator technologies for the separation of fermentation residues of biogas plants were analyzed. The examined biogas plants correspond to the current technological state of the art and have designs developed specifically for the utilization of energy crops. The hydraulic retention time ranged between 45.0 and 83.7 days. The specific methane yields were 0.40-0.43 m(3)N CH(4) per kg VS. The volume loads ranged between 3.69 and 4.00 kg VS/m(3). The degree of degradation was between 77.3% and 82.14%. The screw extractor separator was better suited for biogas slurry separation than the rotary screen separator. The screw extractor separator exhibited a high throughput and good separation efficiency. The efficiency of slurry separation depended on the dry matter content of the fermentation residue. The higher the dry matter content, the higher the proportion of solid phase after separation. In this project, we found that the fermentation residues could be divided into 79.2% fluid phase with a dry matter

  7. Deep residual networks of residual networks for image super-resolution (United States)

    Wei, Xueqi; Yang, Fumeng; Wu, Congzhong


    Single image super-resolution (SISR), which aims at obtaining a high-resolution image from a single low-resolution image, is a classical problem in computer vision. In this paper, we address this problem based on a deep learning method with residual learning in an end-to-end manner. We propose a novel residual-network architecture, Residual networks of Residual networks (RoR), to promote the learning capability of residual networks for SISR. In residual network, the signal can be directly propagated from one unit to any other units in both forward and backward passes when using identity mapping as the skip connections. Based on it, we add level-wise connections upon original residual networks, to dig the optimization ability of residual networks. Our experiments demonstrate the effectiveness and versatility of RoR, it can get a faster convergence speed and gain higher resolution accuracy from considerably increased depth.

  8. Ammonia emission from crop residues : quantification of ammonia volatilization based on crop residue properties

    NARCIS (Netherlands)

    Ruijter, de F.J.; Huijsmans, J.F.M.


    This paper gives an overview of available literature data on ammonia volatilization from crop residues. From these data, a relation is derived for the ammonia emission depending on the N-content of crop residue.

  9. A study on residual stresses in laser surface hardening of a medium carbon steel

    International Nuclear Information System (INIS)

    Yang, Y.S.; Na, S.J.


    The transient thermal stress and the residual stress in laser surface-hardening treatment of a medium carbon steel were analysed by employing a new two-dimensional finite element model. In this formulation, a sliced solution domain, having one element in the hardening direction, was introduced to satisfy the self-equilibrium of the resultant force in the hardening direction. By using the proposed model, the thermal and residual stresses in the laser surface heat treatment were successively calculated. The thermal stress was induced mainly by the temperature gradient and the martensitic phase transformation; the phase transformation was found to have a greater influence on the residual stress than the temperature gradient. The simulation results revealed that a compressive residual stress region occurs near the hardened surface of the workpiece and a tensile residual stress region occurs in the interior of the workpiece, whereas the maximum tensile residual stress occurs along the centre of the laser scanning path in the interior region (y=0). In comparison with the gaussian distribution of the beam power, the square beam mode results in a wider, but shallower, hardened zone. The calculation results also showed that the high-power beam with the high scanning speed is more suitable for laser surface hardening than the low-power beam with the low scanning speed if the heat input per unit length of the workpiece is maintained constant. (orig.)

  10. Process for measuring residual stresses

    International Nuclear Information System (INIS)

    Elfinger, F.X.; Peiter, A.; Theiner, W.A.; Stuecker, E.


    No single process can at present solve all problems. The complete destructive processes only have a limited field of application, as the component cannot be reused. However, they are essential for the basic determination of stress distributions in the field of research and development. Destructive and non-destructive processes are mainly used if investigations have to be carried out on original components. With increasing component size, the part of destructive tests becomes smaller. The main applications are: quality assurance, testing of manufactured parts and characteristics of components. Among the non-destructive test procedures, X-raying has been developed most. It gives residual stresses on the surface and on surface layers near the edges. Further development is desirable - in assessment - in measuring techniques. Ultrasonic and magnetic crack detection processes are at present mainly used in research and development, and also in quality assurance. Because of the variable depth of penetration and the possibility of automation they are gaining in importance. (orig./RW) [de

  11. Quantitative phase microscopy: automated background leveling techniques and smart temporal phase unwrapping. (United States)

    Goldstein, Goldie; Creath, Katherine


    In order for time-dynamic quantitative phase microscopy to yield meaningful data to scientists, raw phase measurements must be converted to sequential time series that are consistently phase unwrapped with minimal residual background shape. Beyond the initial phase unwrapping, additional steps must be taken to convert the phase to time-meaningful data sequences. This consists of two major operations both outlined in this paper and shown to operate robustly on biological datasets. An automated background leveling procedure is introduced that consistently removes background shape and minimizes mean background phase value fluctuations. By creating a background phase value that is stable over time, the phase values of features of interest can be examined as a function of time to draw biologically meaningful conclusions. Residual differences between sequential frames of data can be present due to inconsistent phase unwrapping, causing localized regions to have phase values at similar object locations inconsistently changed by large values between frames, not corresponding to physical changes in the sample being observed. This is overcome by introducing a new method, referred to as smart temporal unwrapping that temporally unwraps and filters the phase data such that small motion between frames is accounted for and phase data are unwrapped consistently between frames. The combination of these methods results in the creation of phase data that is stable over time by minimizing errors introduced within the processing of the raw data.

  12. Immobilization in ceramic waste forms of the residues from treatment of mixed wastes

    International Nuclear Information System (INIS)

    Oversby, V.M.; van Konynenburg, R.A.; Glassley, W.E.; Curtis, P.G.


    The Environmental Restoration and Waste Management Applied Technology Program at LLNL is developing a Mixed Waste Management Facility to demonstrate treatment technologies that provide an alternative to incineration. As part of that program, we are developing final waste forms using ceramic processing methods for the immobilization of the treatment process residues. The ceramic phase assemblages are based on using Synroc D as a starting point and varying the phase assemblage to accommodate the differences in chemistry between the treatment process residues and the defense waste for which Synroc D was developed. Two basic formulations are used, one for low ash residues resulting from treatment of organic materials contaminated with RCRA metals, and one for high ash residues generated from the treatment of plastics and paper products. Treatment process residues are mixed with ceramic precursor materials, dried, calcined, formed into pellets at room temperature, and sintered at 1150 to 1200 degrees C to produce the final waste form. This paper discusses the chemical composition of the waste streams and waste forms, the phase assemblages that serve as hosts for inorganic waste elements, and the changes in waste form characteristics as a function of variation in process parameters

  13. Tank 12H residuals sample analysis report

    Energy Technology Data Exchange (ETDEWEB)

    Oji, L. N. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Shine, E. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Diprete, D. P. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Coleman, C. J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hay, M. S. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)


    The Savannah River National Laboratory (SRNL) was requested by Savannah River Remediation (SRR) to provide sample preparation and analysis of the Tank 12H final characterization samples to determine the residual tank inventory prior to grouting. Eleven Tank 12H floor and mound residual material samples and three cooling coil scrape samples were collected and delivered to SRNL between May and August of 2014.

  14. Does Bt Corn Really Produce Tougher Residues (United States)

    Bt corn hybrids produce insecticidal proteins that are derived from a bacterium, Bacillus thuringiensis. There have been concerns that Bt corn hybrids produce residues that are relatively resistant to decomposition. We conducted four experiments that examined the decomposition of corn residues und...

  15. Residual stresses in steel and zirconium weldments

    International Nuclear Information System (INIS)

    Root, J.H.; Coleman, C.E.; Bowden, J.W.


    Three-dimensional scans of residual stress within intact weldments provide insight into the consequences of various welding techniques and stress-relieving procedures. The neutron diffraction method for nondestructive evaluation of residual stresses has been applied to a circumferential weld in a ferritic steel pipe of outer diameter 114 mm and thickness 8.6 mm. The maximum tensile stresses, 250 MPa in the hoop direction, are found at mid-thickness of the fusion zone. The residual stresses approach zero within 20 mm from the weld center. The residual stresses caused by welding zirconium alloy components are partially to blame for failures due to delayed-hydride cracking. Neutron diffraction measurements in a GTA-welded Zr-2.5 Nb plate have shown that heat treatment at 530 C for 1 h reduces the longitudinal residual strain by 60%. Neutron diffraction has also been used to scan the residual stresses near circumferential electron beam welds in irradiated and unirradiated Zr-2.5 Nb pressure tubes. The residual stresses due to electron beam welding appear to be lower than 130 MPa, even in the as-welded state. No significant changes occur in the residual stress pattern of the electron-beam welded tube, during a prolonged exposure to thermal neutrons and the temperatures typical of an operating nuclear reactor

  16. Densification of FL Chains via Residuated Frames

    Czech Academy of Sciences Publication Activity Database

    Baldi, Paolo; Terui, K.


    Roč. 75, č. 2 (2016), s. 169-195 ISSN 0002-5240 R&D Projects: GA ČR GAP202/10/1826 Keywords : densifiability * standard completeness * residuated lattices * residuated frames * fuzzy logic Subject RIV: BA - General Mathematics Impact factor: 0.625, year: 2016

  17. Spatial resolution enhancement residual coding using hybrid ...

    Indian Academy of Sciences (India)

    a normal video frames possess distinct characteristics compared to a residual frame. In this paper, we .... analyze the characteristics of IP, MC and RE residuals (Kamisli 2010; Rao et al 2007). The estimation ..... Eslami R and Radha H 2007 A new family of nonredundant transforms using hybrid wavelets and directional filter ...

  18. Semantic Tagging with Deep Residual Networks

    NARCIS (Netherlands)

    Bjerva, Johannes; Plank, Barbara; Bos, Johan


    We propose a novel semantic tagging task, semtagging, tailored for the purpose of multilingual semantic parsing, and present the first tagger using deep residual networks (ResNets). Our tagger uses both word and character representations and includes a novel residual bypass architecture. We evaluate

  19. Soil water evaporation and crop residues (United States)

    Crop residues have value when left in the field and also when removed from the field and sold as a commodity. Reducing soil water evaporation (E) is one of the benefits of leaving crop residues in place. E was measured beneath a corn canopy at the soil suface with nearly full coverage by corn stover...

  20. Unicystic ameloblastoma arising from a residual cyst (United States)

    Mahajan, Amit D; Manjunatha, Bhari Sharanesha; Khurana, Neha M; Shah, Navin


    Intraoral swellings involving alveolar ridges in edentulous patients are clinically diagnosed as residual cysts, traumatic bone cysts, Stafne's jaw bone cavity, ameloblastoma and metastatic tumours of the jaw. This case report describes a residual cyst in a 68-year-old edentulous male patient which was enucleated and histopathologically confirmed as a unicystic ameloblastoma. PMID:25199192