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Sample records for separation technique based

  1. Plastic substrates based separation channels in electromigration techniques.

    PubMed

    Charvátová, Jana; Deyl, Zdenek; Klevar, Miroslav; Miksík, Ivan; Eckhardt, Adam

    2004-02-05

    Three types of plastic materials (polyester, polyurethane and polymethylmethacrylate) were tested as materials for manufacturing separation columns (polyester and polyurethane capillaries were used) or separation channels (polymethylmethacrylate) in the chip format. A set of 11 fluorescein isothiocyanate amino acid derivatives was used as the test mixture. Using alpha-cyclodextrin additive to the background electrolyte in the case of the chip separation was also tested. The main problem with all plastic separation media was the selectivity of the separation. The best results, practically identical with bare fused silica capillary, were obtained with the polymethylmethacrylate chip, provided that alpha-cyclodextrin in a concentration 40 mmol/l was added to the background electrolyte. An important observation was that in SDS containing background electrolyte all the plastic materials used exhibited a distinct electroosmotic flow, which was ascribe to the sorption of the negatively charged constituents of the background electrolyte to the capillary wall. Regarding the order in which the individual components of the test mixture were brought to the detector only a single change was observed. Histidine migrated in the polystyrene and polymethylmethacrylate separation channels more slowly than in the bare silica or polyurethane based capillaries.

  2. Separation techniques: Chromatography

    PubMed Central

    Coskun, Ozlem

    2016-01-01

    Chromatography is an important biophysical technique that enables the separation, identification, and purification of the components of a mixture for qualitative and quantitative analysis. Proteins can be purified based on characteristics such as size and shape, total charge, hydrophobic groups present on the surface, and binding capacity with the stationary phase. Four separation techniques based on molecular characteristics and interaction type use mechanisms of ion exchange, surface adsorption, partition, and size exclusion. Other chromatography techniques are based on the stationary bed, including column, thin layer, and paper chromatography. Column chromatography is one of the most common methods of protein purification. PMID:28058406

  3. Carbon Dioxide Capture and Separation Techniques for Gasification-based Power Generation Point Sources

    SciTech Connect

    Pennline, H.W.; Luebke, D.R.; Jones, K.L.; Morsi, B.I.; Heintz, Y.J.; Ilconich, J.B.

    2007-06-01

    The capture/separation step for carbon dioxide (CO2) from large-point sources is a critical one with respect to the technical feasibility and cost of the overall carbon sequestration scenario. For large-point sources, such as those found in power generation, the carbon dioxide capture techniques being investigated by the in-house research area of the National Energy Technology Laboratory possess the potential for improved efficiency and reduced costs as compared to more conventional technologies. The investigated techniques can have wide applications, but the research has focused on capture/separation of carbon dioxide from flue gas (post-combustion from fossil fuel-fired combustors) and from fuel gas (precombustion, such as integrated gasification combined cycle or IGCC). With respect to fuel gas applications, novel concepts are being developed in wet scrubbing with physical absorption; chemical absorption with solid sorbents; and separation by membranes. In one concept, a wet scrubbing technique is being investigated that uses a physical solvent process to remove CO2 from fuel gas of an IGCC system at elevated temperature and pressure. The need to define an ideal solvent has led to the study of the solubility and mass transfer properties of various solvents. Pertaining to another separation technology, fabrication techniques and mechanistic studies for membranes separating CO2 from the fuel gas produced by coal gasification are also being performed. Membranes that consist of CO2-philic ionic liquids encapsulated into a polymeric substrate have been investigated for permeability and selectivity. Finally, dry, regenerable processes based on sorbents are additional techniques for CO2 capture from fuel gas. An overview of these novel techniques is presented along with a research progress status of technologies related to membranes and physical solvents.

  4. Effect of temperature on acid-base equilibria in separation techniques. A review.

    PubMed

    Gagliardi, Leonardo G; Tascon, Marcos; Castells, Cecilia B

    2015-08-19

    Studies on the theoretical principles of acid-base equilibria are reviewed and the influence of temperature on secondary chemical equilibria within the context of separation techniques, in water and also in aqueous-organic solvent mixtures, is discussed. In order to define the relationships between the retention in liquid chromatography or the migration velocity in capillary electrophoresis and temperature, the main properties of acid-base equilibria have to be taken into account for both, the analytes and the conjugate pairs chosen to control the solution pH. The focus of this review is based on liquid-liquid extraction (LLE), liquid chromatography (LC) and capillary electrophoresis (CE), with emphasis on the use of temperature as a useful variable to modify selectivity on a predictable basis. Simplified models were evaluated to achieve practical optimizations involving pH and temperature (in LLE and CE) as well as solvent composition in reversed-phase LC.

  5. Error separation technique for measuring aspheric surface based on dual probes

    NASA Astrophysics Data System (ADS)

    Wei, Zhong-wei; Jing, Hong-wei; Kuang, Long; Wu, Shi-bin

    2013-09-01

    In this paper, we present an error separation method based on dual probes for the swing arm profilometer to calibrate the rotary table errors. Two probes and the rotation axis of swinging arm are in a plane. The scanning tracks cross each other as both probes scan the mirror edge to edge. Since the surface heights should ideally be the same at these scanning crossings, this crossings height information can be used to calibrate the rotary table errors. But the crossings height information contains the swing arm air bearing errors and measurement errors of probes. The errors seriously affect the correction accuracy of rotary table errors. The swing arm air bearing errors and measurement errors of probes are randomly distributed, we use least square method to remove these errors. In this paper, we present the geometry of the dual probe swing arm profilometer system, and the profiling pattern made by both probes. We analyze the influence the probe separation has on the measurement results. The algorithm for stitching together the scans into a surface is also presented. The difference of the surface heights at the crossings of the adjacent scans is used to find a transformation that describes the rotary table errors and then to correct for the errors. To prove the error separation method based on a dual probe can successfully calibrate the rotary table errors, we establish SAP error model and simulate the effect of the error separation method based on a dual probe on calibrating the rotary table errors.

  6. Survey of Biochemical Separation Techniques

    ERIC Educational Resources Information Center

    Nilsson, Melanie R.

    2007-01-01

    A simple laboratory exercise is illustrated that exposes students to wide range of separation techniques in one laboratory program and provides a nice complement to a project-oriented program. Students have learned the basic principles of syringe filtration, centricon, dialysis, gel filtration and solid-phase extraction methodologies and have got…

  7. Radioactive-gas separation technique

    NASA Technical Reports Server (NTRS)

    Haney, R.; King, K. J.; Nellis, D. O.; Nisson, R. S.; Robling, P.; Womack, W.

    1977-01-01

    Cryogenic technique recovers gases inexpensively. Method uses differences in vapor pressures, melting points, and boiling points of components in gaseous mixture. Series of temperature and pressure variations converts gases independently to solid and liquid states, thereby simplifying separation. Apparatus uses readily available cryogen and does not require expensive refrigeration equipment.

  8. Particle separations by electrophoretic techniques

    SciTech Connect

    Ballou, N.E.; Petersen, S.L.; Ducatte, G.R.; Remcho, V.T.

    1996-03-01

    A new method for particle separations based on capillary electrophoresis has been developed and characterized. It uniquely separates particles according to their chemical nature. Separations have been demonstrated with chemically modified latex particles and with inorganic oxide and silicate particles. Separations have been shown both experimentally and theoretically to be essentially independent of particle size in the range of about 0.2 {mu}m to 10 {mu}m. The method has been applied to separations of U0{sub 2} particles from environmental particulate material. For this, an integrated method was developed for capillary electrophoretic separation, collection of separated fractions, and determinations of U0{sub 2} and environmental particles in each fraction. Experimental runs with the integrated method on mixtures of UO{sub 2} particles and environmental particulate material demonstrated enrichment factors of 20 for UO{sub 2} particles in respect to environmental particles in the U0{sub 2}containing fractions. This enrichment factor reduces the costs and time for processing particulate samples by the lexan process by a factor of about 20.

  9. Approaches for enantioselective resolution of pharmaceuticals by miniaturised separation techniques with new chiral phases based on nanoparticles and monolithis.

    PubMed

    Sierra, Isabel; Marina, Maria Luisa; Pérez-Quintanilla, Damián; Morante-Zarcero, Sonia; Silva, Mariana

    2016-10-01

    This article discusses new developments in the preparation of nanoparticles and monoliths with emphasis upon their application as the stationary and pseudo-stationary phases for miniaturised liquid phase separation techniques, which have occurred in the last 10 years (from 2006 to the actuality). References included in this review represent current trends and state of the art in the application of these materials to the analysis, by EKC, CEC and miniaturised chromatography, of chiral compounds with environmental interest such as pharmaceuticals. Due to their extraordinary properties, columns prepared with these new chiral stationary or pseudo-stationary phases, based on materials such as gold nanoparticles, metal-organic frameworks, ordered mesoporous silicas, carbonaceous materials, polymeric-based and silica-based monoliths or molecularly imprinted materials, can usually show some improvements in the separation selectivity, column efficiency and chemical stability in comparison with conventional chiral columns available commercially.

  10. Ionic liquids in separation techniques.

    PubMed

    Berthod, A; Ruiz-Angel, M J; Carda-Broch, S

    2008-03-14

    The growing interest in ionic liquids (ILs) has resulted in an exponentially increasing production of analytical applications. The potential of ILs in chemistry is related to their unique properties as non-molecular solvents: a negligible vapor pressure associated to a high thermal stability. ILs found uses in different sub-disciplines of analytical chemistry. After drawing a rapid picture of the physicochemical properties of selected ILs, this review focuses on their use in separation techniques: gas chromatography (GC), liquid chromatography (LC) and electrophoretic methods (CE). In LC and CE, ILs are not used as pure solvents, but rather diluted in aqueous solutions. In this situation ILs are just salts. They are dual in nature. Too often the properties of the cations are taken as the properties of the IL itself. The lyotropic theory is recalled and the effects of a chaotropic anion are pointed out. Many results can be explained considering all ions present in the solution. Ion-pairing and ion-exchange mechanisms are always present, associated with hydrophobic interactions, when dealing with IL in diluted solutions. Chromatographic and electrophoretic methods are also mainly employed for the control and monitoring of ILs. These methods are also considered. ILs will soon be produced on an industrial scale and it will be necessary to develop reliable analytical procedures for their analysis and control.

  11. Wavelet-based artifact identification and separation technique for EEG signals during galvanic vestibular stimulation.

    PubMed

    Adib, Mani; Cretu, Edmond

    2013-01-01

    We present a new method for removing artifacts in electroencephalography (EEG) records during Galvanic Vestibular Stimulation (GVS). The main challenge in exploiting GVS is to understand how the stimulus acts as an input to brain. We used EEG to monitor the brain and elicit the GVS reflexes. However, GVS current distribution throughout the scalp generates an artifact on EEG signals. We need to eliminate this artifact to be able to analyze the EEG signals during GVS. We propose a novel method to estimate the contribution of the GVS current in the EEG signals at each electrode by combining time-series regression methods with wavelet decomposition methods. We use wavelet transform to project the recorded EEG signal into various frequency bands and then estimate the GVS current distribution in each frequency band. The proposed method was optimized using simulated signals, and its performance was compared to well-accepted artifact removal methods such as ICA-based methods and adaptive filters. The results show that the proposed method has better performance in removing GVS artifacts, compared to the others. Using the proposed method, a higher signal to artifact ratio of -1.625 dB was achieved, which outperformed other methods such as ICA-based methods, regression methods, and adaptive filters.

  12. On-line sample preconcentration and separation technique based on transient trapping in microchip micellar electrokinetic chromatography.

    PubMed

    Sueyoshi, Kenji; Kitagawa, Fumihiko; Otsuka, Koji

    2008-02-15

    This paper describes a novel on-line sample preconcentration and separation technique named transient trapping (tr-trapping), which improves the efficiencies of separation and concentration by using a partially injected short micellar plug in microchip electrophoresis. Although a longer separation length often provides a better resolution of complexed or closely migrating analytes, our proposed theoretical model indicated that a trap-and-release mechanism enables a short micellar zone, which was partially injected into the separation channel, to work as an effective concentration and separation field. Application of the tr-trapping technique to microchip micellar electrokinetic chromatography (MCMEKC) was performed on a newly fabricated 5-way-cross microchip by using sodium dodecyl sulfate and rhodamine dyes as test micelle and analytes, respectively. When the injection times of micelle (t(inj),M) and sample solution (t(inj),S) were 1.0 and 2.0 s, respectively, both the preconcentration and separation of the dyes were completely finished within only 3.0 s. At t(inj),S of 8.0 s, a 393-fold improvement of the detectability was achieved in comparison with conventional MCMEKC. The resolution obtained with tr-trapping-MCMEKC was also better than that with conventional MCMEKC in spite of the 160-fold shorter length of the injected micellar zone at t(inj),M of 1.0 s. These results clearly demonstrated that the tr-trapping technique in MCMEKC provides a rapid, high-resolution and detectability analysis even in the short separation channel on the microchips.

  13. Optimization-based technique for separation and detection of saccadic movements and eye-blinking in electrooculography biosignals.

    PubMed

    Krupiński, Robert; Mazurek, Przemysław

    2011-01-01

    Electrooculography (EOG) gives the possibility of eye tracking using biosignal measurements. Typical EOG signal consists of rapid value changes (saccades) separated by almost constant values. Additionally, the pulse shape from eyelid blinking is observed. The separation of them is possible using numerous methods, like median filtering. The proposed optimization method based on a model fitting using the variable number of parameters gives the possibility of features localization even for nearby saccades and blinking pulses.

  14. Magnetic separation techniques in diagnostic microbiology.

    PubMed Central

    Olsvik, O; Popovic, T; Skjerve, E; Cudjoe, K S; Hornes, E; Ugelstad, J; Uhlén, M

    1994-01-01

    The principles of magnetic separation aided by antibodies or other specific binding molecules have been used for isolation of specific viable whole organisms, antigens, or nucleic acids. Whereas growth on selective media may be helpful in isolation of a certain bacterial species, immunomagnetic separation (IMS) technology can isolate strains possessing specific and characteristic surface antigens. Further separation, cultivation, and identification of the isolate can be performed by traditional biochemical, immunologic, or molecular methods. PCR can be used for amplification and identification of genes of diagnostic importance for a target organism. The combination of IMS and PCR reduces the assay time to several hours while increasing both specificity and sensitivity. Use of streptavidin-coated magnetic beads for separation of amplified DNA fragments, containing both biotin and a signal molecule, has allowed for the conversion of the traditional PCR into an easy-to-read microtiter plate format. The bead-bound PCR amplicons can also easily be sequenced in an automated DNA sequencer. The latter technique makes it possible to obtain sequence data of 300 to 600 bases from 20 to 30 strains, starting with clinical samples, within 12 to 24 h. Sequence data can be used for both diagnostic and epidemiologic purposes. IMS has been demonstrated to be a useful method in diagnostic microbiology. Most recent publications describe IMS as a method for enhancing the specificity and sensitivity of other detection systems, such as PCR, and providing considerable savings in time compared with traditional diagnostic systems. The relevance to clinical diagnosis has, however, not yet been fully established for all of these new test principles. In the case of PCR, for example, the presence of specific DNA in a food sample does not demonstrate the presence of a live organism capable of inducing a disease. However, all tests offering increased sensitivity and specificity of detection

  15. Supramolecular structures based on regioisomers of cinnamyl-α-cyclodextrins – new media for capillary separation techniques

    PubMed Central

    Benkovics, Gabor; Hodek, Ondrej; Havlikova, Martina; Bosakova, Zuzana; Coufal, Pavel; Malanga, Milo; Fenyvesi, Eva; Darcsi, Andras; Beni, Szabolcs

    2016-01-01

    Summary This work focuses on the preparation and application of supramolecular structures based on mono-cinnamyl-α-cyclodextrins (Cin-α-CD). Pure regioisomers of Cin-α-CD having the cinnamyl moiety at the 2-O- or at the 3-O-position, respectively, were prepared, characterized and applied in capillary electrophoresis as additives to the background electrolyte. These new monomer units with a potential to self-organize into supramolecular structures were synthesized via a straightforward one-step synthetic procedure and purified using preparative reversed-phase chromatography allowing a large scale separation of the regioisomers. The ability of the monomers to self-assemble was proved by various methods including NMR spectroscopy and dynamic light scattering (DLS). The light scattering experiments showed that the monomer units have distinguishable ability to form supramolecular structures in different solvents and the size distribution of the aggregates in water can be easily modulated using different external stimuli, such as temperature or competitive guest molecules. The obtained results indicated that the two regioisomers of Cin-α-CD formed different supramolecular assemblies highlighting the fact that the position of the cinnamyl group plays an important role in the intermolecular complex formation. PMID:26877812

  16. Separation of plant membranes by electromigration techniques.

    PubMed

    Canut, H; Bauer, J; Weber, G

    1999-02-05

    The review focuses on the multiple separating regimes that offers the free flow electrophoresis technique: free flow zone electrophoresis, isoelectric focusing, isotachophoresis, free flow step electrophoresis. Also, the feasibility to apply either interval or continuous flow electrophoresis is evaluated. The free flow zone electrophoresis regime is generally selected for the separation of cells, organelles and membranes while the other regimes find their largest fields of applications in the purification of proteins and peptides. The latter regimes present the highest resolution efficiency. Therefore, a large part of this review is devoted to the applicabilities of these different regimes to the purification of organelles and membrane vesicles at the preparative scale. Recent developments, both in instrumentation and procedures, are described. The major achievements in plant membrane fractionation obtained with free flow electrophoresis are outlined. The related procedures are both analytical and preparative: they separate tonoplast and plasma membrane simultaneously from the same homogenate, they discriminate for one type of membrane vesicles of opposite orientation, and process large quantities of membrane material by reason of the continuous flow mode. Recent advances using electromigration techniques that permit confirmation of the dynamic state of membranes, characterisation of complex membrane-dependent functions and discovery of new membrane-localised activities are presented.

  17. Separation of single-walled carbon nanotubes by gel-based chromatography using surfactant step-gradient techniques and development of new instrumentation for studying SWCNT reaction processes

    NASA Astrophysics Data System (ADS)

    Breindel, Leonard M.

    Single-walled carbon nanotube (SWCNT) synthesis methods such as CoMoCATTM, HiPcoTM, pulsed laser vaporization (PLV), and catalytic chemical vapor deposition (CCVD) produce several different distributions of (n,m) SWCNT structures, where ( n,m) defines the nanotube diameter and chiral wrapping angle. Post-synthesis processing such as functionalization and/or separations must therefore be employed to yield high purity electronic or single (n,m) samples. Through the use of a surfactant gradient across a gel-based chromatographic column, separations of single (n,m) species can be achieved. Anionic surfactants such as SDS, SDBS, and AOT display different separation effectiveness for single (n,m) species. Results of near-infrared optical absorption for separated SWCNT surfactant suspensions will be discussed, leading to a broader understanding of the important factors necessary for the gel chromatography separation technique. In particular, the effects of SWCNT/surfactant micelle structure are found to be key to achieving fast, simple SWCNT electronic type separations. Additionally, development of new instrumentation for the near-infrared spectrofluorimetric analysis (NIR-SFA) of SWCNTs is useful to the advancement of fundamental SWCNT research and applications. NIR-SFA, for instance, allows for the (n,m) structures of a sample to be identified and monitored during the progress of a chemical reaction or separation experiment. Seeking to achieve the time resolutions necessary for such experiments, the design and optimizations of a system utilizing single-wavelength excitation by diode lasers coupled with a fast NIR detection system are presented.

  18. Design of pervaporation membrane for organic-liquid separation based on solubility control by plasma-graft filling polymerization technique

    SciTech Connect

    Yamaguchi, Takeo; Nakao, Shinichi; Kimura, Shoji )

    1993-05-01

    Pervaporation performance through the membranes showed the same tendency as solubility results. The authors have prepared the filling-polymerized membrane for pervaporation of organic-liquid mixtures by the plasma-graft polymerization technique. The membrane is composed of two different polymers: a porous substrate which can suppress membrane swelling and a grafted polymer which forms in the pores of the substrate and exhibits selectivity due to its solubility. The objectives of the present study are to design a suitable membrane for an organic-mixture system by the control of the filling-polymer solubility. Specifically, a porous high-density polyethylene membrane and poly(methylacrylate/acrylamide) copolymer were employed as the porous substrate and grafted polymer, respectively, and grafted copolymer solubility was predicted by Hansen solubility parameters (HSP). The grafted polymer composition and its solubility behavior could be controlled by varying the monomer composition, and the solubility change was in accordance with the prediction by HSP. Pervaporation performance through the membranes showed the same tendency as solubility results. The authors concluded that an optimum pervaporation membrane can be designed on the basis of solubility control through use of these techniques for polymerization and prediction.

  19. Technique to separate lidar signal and sunlight.

    PubMed

    Sun, Wenbo; Hu, Yongxiang; MacDonnell, David G; Weimer, Carl; Baize, Rosemary R

    2016-06-13

    Sunlight contamination dominates the backscatter noise in space-based lidar measurements during daytime. The background scattered sunlight is highly variable and dependent upon the surface and atmospheric albedo. The scattered sunlight contribution to noise increases over land and snow surfaces where surface albedos are high and thus overwhelm lidar backscatter from optically thin atmospheric constituents like aerosols and thin clouds. In this work, we developed a novel lidar remote sensing concept that potentially can eliminate sunlight induced noise. The new lidar concept requires: (1) a transmitted laser light that carries orbital angular momentum (OAM); and (2) a photon sieve (PS) diffractive filter that separates scattered sunlight from laser light backscattered from the atmosphere, ocean and solid surfaces. The method is based on numerical modeling of the focusing of Laguerre-Gaussian (LG) laser beam and plane-wave light by a PS. The model results show that after passing through a PS, laser light that carries the OAM is focused on a ring (called "focal ring" here) on the focal plane of the PS filter, very little energy arrives at the center of the focal plane. However, scattered sunlight, as a plane wave without the OAM, focuses at the center of the focal plane and thus can be effectively blocked or ducted out. We also find that the radius of the "focal ring" increases with the increase of azimuthal mode (L) of LG laser light, thus increasing L can more effectively separate the lidar signal away from the sunlight noise.

  20. Extraction and separation of lactate dehydrogenase inhibitors from Poria cocos (Schw.) Wolf based on a hyphenated technique and in vitro methods.

    PubMed

    Li, Sainan; Zhang, Jianxu; Li, Senlin; Liu, Chunming; Liu, Shu; Liu, Zhiqiang

    2017-02-20

    Stroke is one of the most common diseases worldwide. Lactate dehydrogenase inhibitors are widely used in the treatment of ischemic stroke, with natural products considered a promising source of lactate dehydrogenase inhibitors. In this study, ultrafiltration liquid chromatography coupled with mass spectrometry was used for the screening and identification of lactate dehydrogenase inhibitors from Poria cocos. Five lactate dehydrogenase inhibitors were selected: dehydropachymic acid, pachymic acid, dehydrotrametenolic acid, trametenolic acid, and eburicoic acid. The inhibitors were extracted and isolated with purities of 96.75, 98.15, 97.25, 95.46, and 94.88%, respectively, by using a new "hyphenated" strategy of microwave-assisted extraction coupled with counter-current chromatography and centrifugal partition chromatography by a two-phase solvent system of n-hexane/ethyl acetate/ethanol/water at the volume ratio 0.965:1.000:0.936:0.826 v/v/v/v. The bioactivity of the isolated compounds was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay in PC12 cells. The results also showed that the hyphenated technique of microwave-assisted extraction coupled with counter-current chromatography and centrifugal partition chromatography was an efficient method for the continuous extraction and online isolation of chemical constituents from medicinal herbs. Furthermore, the research route based on the activity screening, extraction, separation, and activity verification of the compounds offered advantages of efficiency, orientation, and objectivity.

  1. Separation/Preconcentration Techniques for Rare Earth Elements Analysis

    NASA Astrophysics Data System (ADS)

    Hu, Bin; He, Man; Chen, Beibei; Jiang, Zucheng

    2016-10-01

    The main aim of this chapter exactly characterizes the contribution. The analytical chemistry of the rare earth elements (REEs) very often is highly complicated and the determination of a specific element is impossible without a sample pre-concentration. Sample preparation can be carried out either by separation of the REEs from the matrix or by concentrating the REEs. The separation of REEs from each other is mainly made by chromatography. At the beginning of REE analysis, the method of precipitation/coprecipitation was applied for the treatment of REE mixtures. The method is not applicable for the separation of trace amounts of REEs. The majority of the methods used are based on the distribution of REEs in a two-phase system, a liquid-liquid or a liquid-solid system. Various techniques have been developed for the liquid-liquid extraction (LLE), in particular the liquid phase micro-extraction. The extraction is always combined with a pre-concentration of the REEs in a single drop of extractant or in a hollow fiber filled with the extractant. Further modified techniques for special applications and for difficult REE separation have been developed. Compared to the LLE, the solid phase micro-extraction is preferred. The method is robust and easy to handle, in which the solid phase loaded with the REEs can be used directly for subsequent determination methods. At present, very new solid materials, like nanotubes, are developed and tested for solid phase extraction.

  2. Separation techniques for auto shredder residue

    SciTech Connect

    Bonsignore, P.V.; Jody, B.J.; Daniels, E.J.

    1991-01-01

    Disposal of automobile shredder residue (ASR), remaining from the reclamation of steel from junked automobiles, promises to be an increasing environmental and economic concern. Argonne National Laboratory (ANL) is investigating alternative technology for recovering value from ASR while also, it is hoped, lessening landfill disposal concerns. Of the ASR total, some 20% by weight consists of plastics. Preliminary work at ANL is being directed toward developing a protocol, both mechanical and chemical (solvent dissolution), to separate and recover polyurethane foam and the major thermoplastic fraction from ASR. Feasibility has been demonstrated in laboratory-size equipment. 10 refs., 2 figs.

  3. Column-coupling strategies for multidimensional electrophoretic separation techniques.

    PubMed

    Kler, Pablo A; Sydes, Daniel; Huhn, Carolin

    2015-01-01

    Multidimensional electrophoretic separations represent one of the most common strategies for dealing with the analysis of complex samples. In recent years we have been witnessing the explosive growth of separation techniques for the analysis of complex samples in applications ranging from life sciences to industry. In this sense, electrophoretic separations offer several strategic advantages such as excellent separation efficiency, different methods with a broad range of separation mechanisms, and low liquid consumption generating less waste effluents and lower costs per analysis, among others. Despite their impressive separation efficiency, multidimensional electrophoretic separations present some drawbacks that have delayed their extensive use: the volumes of the columns, and consequently of the injected sample, are significantly smaller compared to other analytical techniques, thus the coupling interfaces between two separations components must be very efficient in terms of providing geometrical precision with low dead volume. Likewise, very sensitive detection systems are required. Additionally, in electrophoretic separation techniques, the surface properties of the columns play a fundamental role for electroosmosis as well as the unwanted adsorption of proteins or other complex biomolecules. In this sense the requirements for an efficient coupling for electrophoretic separation techniques involve several aspects related to microfluidics and physicochemical interactions of the electrolyte solutions and the solid capillary walls. It is interesting to see how these multidimensional electrophoretic separation techniques have been used jointly with different detection techniques, for intermediate detection as well as for final identification and quantification, particularly important in the case of mass spectrometry. In this work we present a critical review about the different strategies for coupling two or more electrophoretic separation techniques and the

  4. [Study of the effect of heat source separation distance on plasma physical properties in laser-pulsed GMAW hybrid welding based on spectral diagnosis technique].

    PubMed

    Liao, Wei; Hua, Xue-Ming; Zhang, Wang; Li, Fang

    2014-05-01

    In the present paper, the authors calculated the plasma's peak electron temperatures under different heat source separation distance in laser- pulse GMAW hybrid welding based on Boltzmann spectrometry. Plasma's peak electron densities under the corresponding conditions were also calculated by using the Stark width of the plasma spectrum. Combined with high-speed photography, the effect of heat source separation distance on electron temperature and electron density was studied. The results show that with the increase in heat source separation distance, the electron temperatures and electron densities of laser plasma did not changed significantly. However, the electron temperatures of are plasma decreased, and the electron densities of are plasma first increased and then decreased.

  5. Implementation of the Frequency Separation Technique in general lineshape codes

    NASA Astrophysics Data System (ADS)

    Alexiou, S.

    2013-06-01

    The Frequency Separation Technique (FST) has been proposed and theoretically documented. It is a technique capable of unifying and improving lineshape calculations, for both accuracy and speed. In this work, we briefly recall its key features and advantages and present a practical way of implementing it in lineshape codes. We note that the FST is a general technique, capable of working with practically any modern lineshape framework that can either employ or go beyond the standard framework.

  6. Technologies and microstructures for separation techniques in chemical analysis

    NASA Astrophysics Data System (ADS)

    Spiering, Vincent L.; Lammerink, Theo S. J.; Jansen, Henri V.; Fluitman, Jan H.; van den Berg, Albert

    1996-09-01

    The possibilities for microtechnology in chemical analysis and separation techniques are discussed. The combination of the materials and the dimensions of structures can limit the sample and waste volumes on the one hand, but also increases the performance of the chemical systems. Especially in high performance chromatography separation systems, where the separation quality is directly depending on the length to width ratio of the fluid channels, there is a large potential for applications. Novel technologies as well as demonstrator devices for different applications will be presented in this paper. Finally, a modular concept for microfluidic systems, in which these micromachined structures can be incorporated, is described and illustrated with a demonstrator.

  7. Separators - Technology review: Ceramic based separators for secondary batteries

    SciTech Connect

    Nestler, Tina; Schmid, Robert; Münchgesang, Wolfram; Bazhenov, Vasilii; Meyer, Dirk C.; Schilm, Jochen; Leisegang, Tilmann

    2014-06-16

    Besides a continuous increase of the worldwide use of electricity, the electric energy storage technology market is a growing sector. At the latest since the German energy transition ('Energiewende') was announced, technological solutions for the storage of renewable energy have been intensively studied. Storage technologies in various forms are commercially available. A widespread technology is the electrochemical cell. Here the cost per kWh, e. g. determined by energy density, production process and cycle life, is of main interest. Commonly, an electrochemical cell consists of an anode and a cathode that are separated by an ion permeable or ion conductive membrane - the separator - as one of the main components. Many applications use polymeric separators whose pores are filled with liquid electrolyte, providing high power densities. However, problems arise from different failure mechanisms during cell operation, which can affect the integrity and functionality of these separators. In the case of excessive heating or mechanical damage, the polymeric separators become an incalculable security risk. Furthermore, the growth of metallic dendrites between the electrodes leads to unwanted short circuits. In order to minimize these risks, temperature stable and non-flammable ceramic particles can be added, forming so-called composite separators. Full ceramic separators, in turn, are currently commercially used only for high-temperature operation systems, due to their comparably low ion conductivity at room temperature. However, as security and lifetime demands increase, these materials turn into focus also for future room temperature applications. Hence, growing research effort is being spent on the improvement of the ion conductivity of these ceramic solid electrolyte materials, acting as separator and electrolyte at the same time. Starting with a short overview of available separator technologies and the separator market, this review focuses on ceramic-based separators

  8. Separators - Technology review: Ceramic based separators for secondary batteries

    NASA Astrophysics Data System (ADS)

    Nestler, Tina; Schmid, Robert; Münchgesang, Wolfram; Bazhenov, Vasilii; Schilm, Jochen; Leisegang, Tilmann; Meyer, Dirk C.

    2014-06-01

    Besides a continuous increase of the worldwide use of electricity, the electric energy storage technology market is a growing sector. At the latest since the German energy transition ("Energiewende") was announced, technological solutions for the storage of renewable energy have been intensively studied. Storage technologies in various forms are commercially available. A widespread technology is the electrochemical cell. Here the cost per kWh, e. g. determined by energy density, production process and cycle life, is of main interest. Commonly, an electrochemical cell consists of an anode and a cathode that are separated by an ion permeable or ion conductive membrane - the separator - as one of the main components. Many applications use polymeric separators whose pores are filled with liquid electrolyte, providing high power densities. However, problems arise from different failure mechanisms during cell operation, which can affect the integrity and functionality of these separators. In the case of excessive heating or mechanical damage, the polymeric separators become an incalculable security risk. Furthermore, the growth of metallic dendrites between the electrodes leads to unwanted short circuits. In order to minimize these risks, temperature stable and non-flammable ceramic particles can be added, forming so-called composite separators. Full ceramic separators, in turn, are currently commercially used only for high-temperature operation systems, due to their comparably low ion conductivity at room temperature. However, as security and lifetime demands increase, these materials turn into focus also for future room temperature applications. Hence, growing research effort is being spent on the improvement of the ion conductivity of these ceramic solid electrolyte materials, acting as separator and electrolyte at the same time. Starting with a short overview of available separator technologies and the separator market, this review focuses on ceramic-based separators

  9. Filtrates and Residues: Gel Filtration--An Innovative Separation Technique.

    ERIC Educational Resources Information Center

    Blumenfeld, Fred; Gardner, James

    1985-01-01

    Gel filtration is a form of liquid chromatography that separates molecules primarily on the basis of their size. Advantages of using this technique, theoretical aspects, and experiments (including procedures used) are discussed. Several questions for students to answer (with answers) are also provided. (JN)

  10. Sample detection and analysis techniques for electrophoretic separation

    NASA Technical Reports Server (NTRS)

    Falb, R. D.; Hughes, K. E.; Powell, T. R.

    1975-01-01

    Methods for detecting and analyzing biological agents suitable for space flight operations were studied primarily by literature searches which were conducted of cell separation techniques. Detection methods discussed include: photometrometric, electric, radiometric, micrometry, ultrasonic, microscopic, and photographic. A bibliography, and a directory of vendors are included along with an index of commercial hardware.

  11. The use of micellar solutions for novel separation techniques

    SciTech Connect

    Roberts, B.L.

    1993-12-31

    Surfactant based separation techniques based on the solubilization of organic compounds into the nonpolar interior of a micelle or electrostatic attraction of ionized metals and metal complexes to the charged surface of a micelle were studied in this work. Micellar solutions were used to recover two model volatile organic compounds emitted by the printing and painting industries (toluene and amyl acetate) and to investigate the effect of the most important variables in the surfactant enhanced carbon regeneration (SECR) process. SECR for liquid phase applications was also investigated in which the equilibrium adsorption of cetyl pyridinium chloride (CPC) and sodium dodecyl sulfate (SDS) on activated carbon were measured. Micellar-enhanced ultrafiltration (MEUF) was investigated using spiral wound membranes for the simultaneous removal of organic compounds, metals and metal complexes dissolved in water, with emphasis on pollution control applications. Investigations of MEUF to remove 99+ per cent of trichloroethylene (TCE) from contaminated groundwater using criteria such as: membrane flux, solubilization equilibrium constant, surfactant molecular weight, and Krafft temperature led to the selection of an anionic disulfonate with a molecular weight of 642 (DOWFAX 8390). These data and results from supporting experiments were used to design a system which could clean-up water in a 100,000 gallon/day operation. A four stage process was found to be an effective design and estimated cost for such an operation were found to be in the range of the cost of mature competitive technologies.

  12. Enhanced Landfill Mining case study: Innovative separation techniques

    NASA Astrophysics Data System (ADS)

    Cuyvers, Lars; Moerenhout, Tim; Helsen, Stefan; Van de Wiele, Katrien; Behets, Tom; Umans, Luk; Wille, Eddy

    2014-05-01

    In 2011, a corporate vision on Enhanced Landfill Mining (ELFM)1 was approved by the OVAM Board of directors, which resulted in an operational programme over the period 2011-2015. OVAM (Public Waste Agency of Flanders) is the competent authority in charge of waste, Sustainable Materials Management (SMM) and contaminated soil management in Flanders. The introduction of the ELFM concept needs to be related with the concept of SMM and the broader shift to a circular economy. Within the concept of ELFM, landfills are no longer considered to be a final and static situation, but a dynamic part of the materials cycle. The main goal of this research programme is to develop a comprehensive policy on resource management to deal with the issue of former landfills. In order to investigate the opportunities of ELFM, the OVAM is applying a three step approach including mapping, surveying and mining of these former landfills. As a result of the mapping part over 2,000 landfill sites, that will need to be dealt with, were revealed. The valorisation potential of ELFM could be assigned to different goals, according to the R³P-concept : Recycling of Materials, Recovery of Energy, Reclamation of Land and Protection of drinking water supply. . On behalf of the OVAM, ECOREM was assigned to follow-up a pilot case executed on a former landfill, located in Zuienkerke, Flanders. Within this case study some technical tests were carried out on the excavated waste material to investigate the possibilities for a waste to resource conversion. The performance of both on site and off site techniques were evaluated. These testings also contribute to the mapping part of OVAM's research programme on ELFM and reveal more information on the composition of former landfills dating from different era's. In order to recover as many materials as possible, five contractors were assigned to perform separation tests on the bulk material from the Zuienkerke landfill. All used techniques were described

  13. Retrieval of a separated instrument using Masserann technique

    PubMed Central

    Thirumalai, Arun Kulandaivelu; Sekar, Mahalaxmi; Mylswamy, Sumitha

    2008-01-01

    The fracture of endodontic instruments is a procedural problem creating a major obstacle to normal routine therapy. The separated instrument, particularly a broken file, leads to metallic obstruction in the root canal and impedes efficient cleaning and shaping. When an attempt to bypass such a fragment becomes difficult, it should be retrieved by mechanical devices. Masserann kit is one such device for orthograde removal of intracanal metallic obstructions. These clinical cases demonstrate the usage of Masserann technique in removal of separated instruments in anterior and also the posterior teeth. PMID:20142883

  14. Beneficiation of coal pond ash by physical separation techniques.

    PubMed

    Lee, Sung-Joo; Cho, Hee-Chan; Kwon, Ji-Hoe

    2012-08-15

    In this study, investigations to develop a beneficiation process for separating coal pond ash into various products were undertaken. To this end, coal pond ash samples with different particle size ranges were tested in terms of their washability characteristics in a float-and-sink analysis. It was found that coal pond ash was heterogeneous in nature consisting of particles that varied in terms of their size and composition. However, it can be made more homogenous using a gravity separation method. Therefore, the possibility of separating coal pond ash was tested on standard equipment typically used for gravity concentration. To increase the separation efficiency, coal ash was separated according to the size of the particles and each size fraction was tested using equipment appropriate for the corresponding sizes. A hindered-settling column and a shaking table were tested for their ability to treat the 1.19 × 0.074 mm size fraction, and a Falcon concentrator was evaluated for its ability to treat the -0.074 mm size fraction. The results showed that various marketable products, such as lightweight aggregate, sand and high-carbon fuel, can be recovered from coal pond ash using simple physical separation techniques.

  15. Separation of similar yeast strains by IEF techniques.

    PubMed

    Horká, Marie; Růzicka, Filip; Holá, Veronika; Slais, Karel

    2009-06-01

    Rapid and reliable identification of the etiological agents of infectious diseases, especially species that are hardly distinguishable by routinely used laboratory methods, e.g. Candida albicans from C. dubliniensis, is necessary for early administration of an appropriate therapy. Similarly, the differentiation between biofilm-positive and biofilm-negative yeast strains is necessary for the choice of a therapeutic strategy due to higher resistance of the biofilm-positive strains to antifungals. In this study rapid separation and identification of similar strains of Candida, cells and/or their lysates, based on IEF are outlined. The isoelectric points of the monitored "similar pairs" of Candidas, C. albicans and C. dubliniensis and the biofilm-positive C. parapsilosis, C. tropicalis and their biofilm-negative strains were determined by CIEF with UV detection in the acidic pH gradient. The differences between their isoelectric points were up to 0.3 units of pI. Simultaneously, a fast and a simple technique was developed for the lysis of the outer membrane cell and characteristic fingerprints were found in lysate electrophoreograms and in gels from the capillary or the gel IEF, respectively.

  16. Floating-point scaling technique for sources separation automatic gain control

    NASA Astrophysics Data System (ADS)

    Fermas, A.; Belouchrani, A.; Ait-Mohamed, O.

    2012-07-01

    Based on the floating-point representation and taking advantage of scaling factor indetermination in blind source separation (BSS) processing, we propose a scaling technique applied to the separation matrix, to avoid the saturation or the weakness in the recovered source signals. This technique performs an automatic gain control in an on-line BSS environment. We demonstrate the effectiveness of this technique by using the implementation of a division-free BSS algorithm with two inputs, two outputs. The proposed technique is computationally cheaper and efficient for a hardware implementation compared to the Euclidean normalisation.

  17. Remove volatile organic compounds (VOCs) with membrane separation techniques.

    PubMed

    Zhang, Lin; Weng, Huan-xin; Chen, Huan-lin; Gao, Cong-jie

    2002-04-01

    Membrane separation, a new technology for removing VOCs including pervaporation, vapor permeation, membrane contactor, and membrane bioreactor was presented. Comparing with traditional techniques, these special techniques are an efficient and energy-saving technology. Vapor permeation can be applied to recovery of organic solvents from exhaust streams. Membrane contactor could be used for removing or recovering VOCs from air or wastewater. Pervaporation and vapor permeation are viable methods for removing VOCs from wastewater to yield a VOC concentrate which could either be destroyed by conventional means, or be recycled for reuse.

  18. Magnetic separation techniques in sample preparation for biological analysis: a review.

    PubMed

    He, Jincan; Huang, Meiying; Wang, Dongmei; Zhang, Zhuomin; Li, Gongke

    2014-12-01

    Sample preparation is a fundamental and essential step in almost all the analytical procedures, especially for the analysis of complex samples like biological and environmental samples. In past decades, with advantages of superparamagnetic property, good biocompatibility and high binding capacity, functionalized magnetic materials have been widely applied in various processes of sample preparation for biological analysis. In this paper, the recent advancements of magnetic separation techniques based on magnetic materials in the field of sample preparation for biological analysis were reviewed. The strategy of magnetic separation techniques was summarized. The synthesis, stabilization and bio-functionalization of magnetic nanoparticles were reviewed in detail. Characterization of magnetic materials was also summarized. Moreover, the applications of magnetic separation techniques for the enrichment of protein, nucleic acid, cell, bioactive compound and immobilization of enzyme were described. Finally, the existed problems and possible trends of magnetic separation techniques for biological analysis in the future were proposed.

  19. Aerodynamic measurement techniques. [laser based diagnostic techniques

    NASA Technical Reports Server (NTRS)

    Hunter, W. W., Jr.

    1976-01-01

    Laser characteristics of intensity, monochromatic, spatial coherence, and temporal coherence were developed to advance laser based diagnostic techniques for aerodynamic related research. Two broad categories of visualization and optical measurements were considered, and three techniques received significant attention. These are holography, laser velocimetry, and Raman scattering. Examples of the quantitative laser velocimeter and Raman scattering measurements of velocity, temperature, and density indicated the potential of these nonintrusive techniques.

  20. Planetary Gearbox Fault Detection Using Vibration Separation Techniques

    NASA Technical Reports Server (NTRS)

    Lewicki, David G.; LaBerge, Kelsen E.; Ehinger, Ryan T.; Fetty, Jason

    2011-01-01

    Studies were performed to demonstrate the capability to detect planetary gear and bearing faults in helicopter main-rotor transmissions. The work supported the Operations Support and Sustainment (OSST) program with the U.S. Army Aviation Applied Technology Directorate (AATD) and Bell Helicopter Textron. Vibration data from the OH-58C planetary system were collected on a healthy transmission as well as with various seeded-fault components. Planetary fault detection algorithms were used with the collected data to evaluate fault detection effectiveness. Planet gear tooth cracks and spalls were detectable using the vibration separation techniques. Sun gear tooth cracks were not discernibly detectable from the vibration separation process. Sun gear tooth spall defects were detectable. Ring gear tooth cracks were only clearly detectable by accelerometers located near the crack location or directly across from the crack. Enveloping provided an effective method for planet bearing inner- and outer-race spalling fault detection.

  1. Adaptive parameter blind source separation technique for wheel condition monitoring

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; Gao, Hongli; Liu, Qiyue; Farzadpour, F.; Grebe, C.; Tian, Ying

    2017-06-01

    Wheel condition monitoring has played a key role in the safe operation of railway vehicles. Blind source separation (BSS) is an attractive tool due to its excellent performance in separating source signals from their mixtures when no detailed knowledge of defective sources and the mixing process is assumed. In this paper, we propose an adaptive parameter BSS approach based on the adaptive time-frequency distributions theory in order to deal with the non-stationary blind separation problem and apply it to wheel defect monitoring. Some classical time-frequency signal analysis and BSS methods are applied in comparison with the proposed approach through frequency-varying non-stationary and time-varying non-stationary simulations. Experiments of single and multi-fault wheels have been conducted using the wheel/rail simulation facility to illustrate the effectiveness of the proposed method in processing the non-stationary signals with varying fault complexity.

  2. Ab Initio Molecular Dynamics Using Recursive, Spatially Separated, Overlapping Model Subsystems Mixed within an ONIOM-Based Fragmentation Energy Extrapolation Technique.

    PubMed

    Li, Junjie; Iyengar, Srinivasan S

    2015-09-08

    Here, we demonstrate the application of fragment-based electronic structure calculations in (a) ab initio molecular dynamics (AIMD) and (b) reduced dimensional potential calculations, for medium- and large-sized protonated water clusters. The specific fragmentation algorithm used here is derived from ONIOM, but includes multiple, overlapping “model” systems. The interaction between the various overlapping model systems is (a) approximated by invoking the principle of inclusion-exclusion at the chosen higher level of theory and (b) within a real calculation performed at the chosen lower level of theory. The fragmentation algorithm itself is written using bit-manipulation arithmetic, which will prove to be advantageous, since the number of fragments in such methods has the propensity to grow exponentially with system size. Benchmark calculations are performed for three different protonated water clusters: H₉O₄⁺, H₁₃O₆⁺ and H(H₂O)₂₁⁺. For potential energy surface benchmarks, we sample the normal coordinates and compare our surface energies with full MP2 and CCSD(T) calculations. The mean absolute error for the fragment-based algorithm is <0.05 kcal/mol, when compared with MP2 calculations, and <0.07 kcal/mol, when compared with CCSD(T) calculations over 693 different geometries for the H₉O₄⁺ system. For the larger H(H₂O)₂₁⁺ water cluster, the mean absolute error is on the order of a 0.1 kcal/mol, when compared with full MP2 calculations for 84 different geometries, at a fraction of the computational cost. Ab initio dynamics calculations were performed for H₉O₄⁺ and H₁₃O₆⁺, and the energy conservation was found to be of the order of 0.01 kcal/mol for short trajectories (on the order of a picosecond). The trajectories were kept short because our algorithm does not currently include dynamical fragmentation, which will be considered in future publications. Nevertheless, the velocity autocorrelation functions and their

  3. Separation of turkey lactate dehydrogenase isoenzymes using isoelectric focusing technique.

    PubMed

    Heinová, Dagmar; Kostecká, Zuzana; Csank, Tomáš

    2016-01-01

    Native polyacrylamide gel electrophoresis at pH 8.8 did not allow to separate lactate dehydrogenase (LDH) isoenzymes of turkey origin. Five electrophoretically distinguishable forms of the enzyme were detected in serum and tissues of turkey using IEF technique in a pH range of 3-9. Generally, three different groups were seen: (i) those having an anodic domination (heart, kidney, pancreas, and erythrocytes) with mainly LDH-1 fraction, (ii) those having a cathodic domination (breast muscle and serum) with prevalence of LDH-5, and (iii) those with a more uniform distribution (liver, spleen, lung, and brain). The specific enzyme activity was the highest in the breast muscle, followed by heart muscle, and brain. Low activities were detected in serum, kidney, and liver.

  4. A simple color separation technique for solar tissue photocoagulation

    NASA Astrophysics Data System (ADS)

    Batista, Nídia; Liang, Dawei

    2011-07-01

    Aiming at studying solar photocoagulation in biological tissue with both low energy and high energy portions of solar spectrum, a simple color separation technique is proposed. The chromatic aberration characteristic of Fresnel lens is exploited to achieve color separation by a plane mirror with a large central elliptical hole, reflecting the solar radiation above 600nm to one fused silica light guide, while allowing the passage of the remaining radiation to another guide. ZEMAX™ ray-tracing code is used to optimize the performance of each optical component. To attain a stable solar coagulation, the prototype is tested on a two-axis solar tracker. The ex vivo measurement is performed on chicken breasts at the solar power level of 30W and the exposure time of 60 seconds, attaining a uniform coagulation over a large area of 15mm x 15mm. A strong dependence of the penetration depth on wavelength is observed. Our cost effective solar photocoagulation prototype produces the same type and extent of tissue coagulation ordinarily achieved with surgical laser equipment.

  5. Composite separators and redox flow batteries based on porous separators

    DOEpatents

    Li, Bin; Wei, Xiaoliang; Luo, Qingtao; Nie, Zimin; Wang, Wei; Sprenkle, Vincent L.

    2016-01-12

    Composite separators having a porous structure and including acid-stable, hydrophilic, inorganic particles enmeshed in a substantially fully fluorinated polyolefin matrix can be utilized in a number of applications. The inorganic particles can provide hydrophilic characteristics. The pores of the separator result in good selectivity and electrical conductivity. The fluorinated polymeric backbone can result in high chemical stability. Accordingly, one application of the composite separators is in redox flow batteries as low cost membranes. In such applications, the composite separator can also enable additional property-enhancing features compared to ion-exchange membranes. For example, simple capacity control can be achieved through hydraulic pressure by balancing the volumes of electrolyte on each side of the separator. While a porous separator can also allow for volume and pressure regulation, in RFBs that utilize corrosive and/or oxidizing compounds, the composite separators described herein are preferable for their robustness in the presence of such compounds.

  6. Stable isotope enrichment techniques and ORNL separation status

    NASA Astrophysics Data System (ADS)

    Tracy, J. G.; Bell, W. A.; Veach, A. M.; Caudill, H. H.; Milton, H. T.

    1987-05-01

    The isotope separation program is described, emphasizing present state-of-the-art techniques utilized to achieve specific isotopic requirements. An interesting problem addressed here is the calutron enrichment of rare-earth isotopes where small quantities of feed (< 5 g) are available, and the unresolved feed is to be recovered and recycled. Conventional ion-source units using graphite and stainless steel deteriorate in the halogenating atmosphere or are permeable to rare-earth compounds, reducing the process efficiency. An ion source has been developed using boron nitride for containing the halogenating agent and rare-earth compounds. Tests have been successfully conducted using Lu 2O 3 and the in situ chlorinating technique with CCl 4. Collectively, 166 mg of 176Lu were recovered from two runs using 2.95 and 1.10 g of 44.5% 176Lu. Process efficiency of 10.5% was achieved, and 1.2 g of the unresolved feed were recovered. Material compatibility of the boron nitride, carbon tetrachloride, and lutetium compounds has been established.

  7. Sheathless Size-Based Acoustic Particle Separation

    PubMed Central

    Guldiken, Rasim; Jo, Myeong Chan; Gallant, Nathan D.; Demirci, Utkan; Zhe, Jiang

    2012-01-01

    Particle separation is of great interest in many biological and biomedical applications. Flow-based methods have been used to sort particles and cells. However, the main challenge with flow based particle separation systems is the need for a sheath flow for successful operation. Existence of the sheath liquid dilutes the analyte, necessitates precise flow control between sample and sheath flow, requires a complicated design to create sheath flow and separation efficiency depends on the sheath liquid composition. In this paper, we present a microfluidic platform for sheathless particle separation using standing surface acoustic waves. In this platform, particles are first lined up at the center of the channel without introducing any external sheath flow. The particles are then entered into the second stage where particles are driven towards the off-center pressure nodes for size based separation. The larger particles are exposed to more lateral displacement in the channel due to the acoustic force differences. Consequently, different-size particles are separated into multiple collection outlets. The prominent feature of the present microfluidic platform is that the device does not require the use of the sheath flow for positioning and aligning of particles. Instead, the sheathless flow focusing and separation are integrated within a single microfluidic device and accomplished simultaneously. In this paper, we demonstrated two different particle size-resolution separations; (1) 3 μm and 10 μm and (2) 3 μm and 5 μm. Also, the effects of the input power, the flow rate, and particle concentration on the separation efficiency were investigated. These technologies have potential to impact broadly various areas including the essential microfluidic components for lab-on-a-chip system and integrated biological and biomedical applications. PMID:22368502

  8. Use of Chromatography Techniques to Separate a Mixture of Substances

    ERIC Educational Resources Information Center

    Donaldson, W.

    1976-01-01

    Explains the separation of the constituents of mixtures on one piece of chromatography paper. The example presented involves a vitamin C tablet, a disprin tablet, and a glucose tablet. Outlined are two methods for separating the constituents. (GS)

  9. Controlled shear filtration: A novel technique for animal cell separation.

    PubMed

    Vogel, J H; Kroner, K H

    1999-06-20

    A novel rotary microfiltration technique specifically suited for the separation of animal cells has been developed. The concept allows the independent adjustment of wall shear stress, transmembrane pressure, and residence time, allowing straightforward optimization of the microfiltration process. By using a smooth, conically shaped rotor, it is possible to establish a controlled shear field in which animal cells experience a significant hydrodynamic lift away from the membrane surface. It is shown in preliminary experiments that shear-induced cell-rupture speeds up membrane clogging and that cell debris poses the most significant problem in harvesting of BHK cell cultures by dynamic microfiltration. However, a threshold value of shear stability exists which depends on the frequency of passing the shear field, the residence time in the shear field, as well as on cell status. By operating close to this threshold value, cell viability can be maintained while concentration polarization is efficiently minimized. By applying this concept, it is possible to attain flux rates several times higher compared to conventional crossflow filtration. Controlled shear filtration (CSF) can be used for batch harvesting as well as for cell retention in high cell density systems. In batch harvesting of hIL-2 from rBHK cell culture, a constant flux rate of 290 L h-1 m-2 has been adjusted without indication of membrane clogging or fouling.

  10. Developing synthesis techniques for zeolitic-imidazolate framework membranes for high resolution propylene/propane separation

    NASA Astrophysics Data System (ADS)

    Kwon, Hyuk Taek

    Propylene/propane separation is one of the most challenging separations, currently achieved by energy-intensive cryogenic distillation. Despite the great potentials for energy-efficient membrane-based propylene/propane separation processes, no commercial membranes are available due to the limitations (i.e., low selectivity) of current polymeric materials. Zeolitic imidazolate frameworks (ZIFs) are promising membrane materials primarily due to their well-defined ultra-micropores with controllable surface chemistry along with their relatively high thermal/chemical stabilities. In particular, ZIF-8 with the effective aperture size of ~ 4.0 A has been shown very promising for propylene/propane separation. Despite the extensive research on ZIF-8 membranes, only a few of ZIF-8 membranes have displayed good propylene/propane separation performances presumably due to the challenges of controlling the microstructures of polycrystalline membranes. Since the membrane microstructures are greatly influenced by processing techniques, it is critically important to develop new techniques. In this dissertation, three state-of-the-art ZIF membrane synthesis techniques are developed. The first is a one-step in-situ synthesis technique based on the concept of counter diffusion. The technique enabled us to obtain highly propylene selective ZIF-8 membranes in less than a couple of hours with exceptional mechanical strength. Most importantly, due to the nature of the counter-diffusion concept, the new method offered unique opportunities such as healing defective membranes (i.e., poorly-intergrown) as well as significantly reducing the consumption of costly ligands and organic solvents. The second is a microwave-assisted seeding technique. Using this new seeding technique, we were able to prepare seeded supports with a high packing density in a couple of minutes, which subsequently grown into highly propylene-selective ZIF-8 membranes with an average propylene/propane selectivity of ~40

  11. Achiral and Chiral Separations Using Micellar Electrokinetic Chromatography, Polyelectrolyte Multilayer Coatings, and Mixed Mode Separation Techniques with Molecular Micelles

    PubMed Central

    Luces, Candace A.; Warner, Isiah M.

    2014-01-01

    Mixed mode separation using a combination of micellar electrokinetic chromatography (MEKC) and polyelectrolyte multilayer (PEM) coatings is herein reported for the separation of achiral and chiral analytes. Many analytes are difficult to separate by MEKC and PEM coatings alone. Therefore, the implementation of a mixed mode separation provides several advantages for overcoming the limitations of these well-established methods. In this study, it was observed that achiral separations using MEKC and PEM coatings individually resulted in partial resolution of 8 very similar aryl ketones when the molecular micelle (sodium poly(N-undecanoyl-l-glycinate) (poly-SUG)) concentration was varied from 0.25% – 1.00% (w/v) and the bilayer number varied from 2 – 4. However, when mixed mode separation was introduced, baseline resolution was achieved for all 8 analytes. In the case of chiral separations, temazepam, aminoglutethimide, benzoin, benzoin methyl ether and coumachlor were separated using the three separation techniques. For chiral separations, the chiral molecular micelle, sodium poly(N-undecanoyl-l-leucylvalinate) (poly-l-SULV), was employed at concentrations of 0.25–1.50% (w/v) for both MEKC and PEM coatings. Overall, the results revealed partial separation with MEKC and PEM coatings individually. However, mixed mode separation enabled baseline separation of each chiral mixture. The separation of achiral and chiral compounds from different compound classes demonstrates the versatility of this mixed mode approach. PMID:20155738

  12. Metal-organic frameworks for membrane-based separations

    NASA Astrophysics Data System (ADS)

    Denny, Michael S.; Moreton, Jessica C.; Benz, Lauren; Cohen, Seth M.

    2016-12-01

    As research into metal-organic frameworks (MOFs) enters its third decade, efforts are naturally shifting from fundamental studies to applications, utilizing the unique features of these materials. Engineered forms of MOFs, such as membranes and films, are being investigated to transform laboratory-synthesized MOF powders to industrially viable products for separations, chemical sensors and catalysts. Following encouraging demonstrations of gas separations using MOF-based membranes, liquid-phase separations are now being explored in an effort to build effective membranes for these settings. In this Review, we highlight MOF applications that are in their nascent stages, specifically liquid-phase separations using MOF-based mixed-matrix membranes. We also highlight the analytical techniques that provide important insights into these materials, particularly at surfaces and interfaces, to better understand MOFs and their interactions with other materials, which will ultimately lead to their use in advanced technologies.

  13. Multi-stage separations based on dielectrophoresis

    DOEpatents

    Mariella, Jr., Raymond P.

    2004-07-13

    A system utilizing multi-stage traps based on dielectrophoresis. Traps with electrodes arranged transverse to the flow and traps with electrodes arranged parallel to the flow with combinations of direct current and alternating voltage are used to trap, concentrate, separate, and/or purify target particles.

  14. Separation of Acids, Bases, and Neutral Compounds

    NASA Astrophysics Data System (ADS)

    Fujita, Megumi; Mah, Helen M.; Sgarbi, Paulo W. M.; Lall, Manjinder S.; Ly, Tai Wei; Browne, Lois M.

    2003-01-01

    Separation of Acids, Bases, and Neutral Compounds requires the following software, which is available for free download from the Internet: Netscape Navigator, version 4.75 or higher, or Microsoft Internet Explorer, version 5.0 or higher; Chime plug-in, version compatible with your OS and browser (available from MDL); and Flash player, version 5 or higher (available from Macromedia).

  15. Shape-based separation of microparticles with magnetic fields

    NASA Astrophysics Data System (ADS)

    Wang, Cheng; Zhou, Ran

    2016-11-01

    Precise manipulations, e.g., sorting and focusing, of nonspherical micro-particles in fluidic environment has important applications in the fields of biology sciences and biomedical engineering. However, non-spherical microparticles are hard to manipulate because they tumble in shear flows. Most of existing techniques, including traditional filtration and centrifugation, and recent microfluidic technology, have difficulty in separating microparticles by shape. We demonstrate a novel shape-based separation technique by combining external magnetic fields with pressure-driven flows in a microchannel. Due to the magnetic field, prolate ellipsoidal particles migrate laterally at different speeds than the spherical ones, leading to effective separation. Our experimental investigations reveal the underlying physical mechanism of the observed shape-dependent migration. We find that the magnetic field breaks the rotational symmetry of the nonspherical particles, and induces shape-dependent lift force and migration velocity.

  16. Nonconventional techniques for separation of biosynthetic amino acids.

    PubMed

    Kloetzer, Lenuţa; Poştaru, Mădălina; Cheptea, Corina; Caşcaval, D; Galaction, Anca-Irina

    2014-01-01

    Amino acids can be obtained by biosynthesis, by protein hydrolysis or by extraction from natural sources. The most efficient methods are the first two, but the separation of amino acids from fermentation broths or protein hydrolysates is rather difficult. Amino acids dissociate in aqueous solutions, forming characteristic ionic species depending on the solution pH-value. These properties make amino acids to be hydrophilic at any pH-value. This paper presents a review of the separation studies of some amino acids by nonconventional methods, namely individual or selective reactive extraction. Separation of some amino acids from their mixture obtained either by fermentation or protein hydrolysis by reactive extraction with different extractants indicated the possibility of the amino acids selective separation as a function of the pH-value of aqueous solution correlated with the acidic or basic character of each amino acid.

  17. A new technique for the separation and analysis of organomercury compounds: HPLC-PCO-CVAAS

    SciTech Connect

    Engelhart, W.G.

    1994-12-31

    While methodologies and instrumentation for mercury are well established, a simple, reliable technique for quantifying organomercury compounds has not emerged. The environmental impact of organomercurials cannot be accurately assessed without data from reliable, standardized analytical procedures. AOAC methods do exist for the analysis of methylmercury in fish tissue and are used for compliance monitoring of the FDA`s 1 ppm action level. However, these gas chromatographic based methods exhibit poor selectivity for organomercury compounds and limited sensitivity due to the small injection volumes used. Virtually all other publications in the field are feasibility studies reporting results obtained using modified, experimental instrumentation. Difficulties in interfacing the instruments required for separation with the instruments performing the quantitation function have hindered adoption of these experimental approaches as routine analytical methods. A new technique for the separation and analysis of organomercury compounds that overcomes the limitations of other techniques has recently been demonstrated. This technique termed HPLC-PCO-CVAAS combines high performance liquid chromatography with a post column oxidation step by followed by cold vapor atomic absorption spectroscopy. The underlying principles of the HPLC-PCO-CVAAS technique will be discussed and contrasted with other techniques. Analytical results obtained with methyl, phenyl and ethyl mercury species, and inorganic mercury (II) will be reported.

  18. Pervaporation membranes--a novel separation technique for trace organics

    SciTech Connect

    Zhu, C.L.; Yuang, C.W.; Fried, J.R.; Greenberg, D.B.

    1983-05-01

    A viable separation of chlorinated hydrocarbons from dilute aqueous solutions can be achieved by a process known as pervaporation. It is applicable to the removal of chlorinated organics, pesticides, herbicides, etc., from industrial and municipal water supplies. The process separates trace amounts of hydrocarbons through polymer membranes by means of a liquid-vapor mass-transfer. The method involves the selective sorption of a liquid mixture, followed by diffusion, and then desorption into a vapor phase on the downstream side of the membrane. (JMT)

  19. Separation techniques: spiral-wound permeators for purification

    SciTech Connect

    Schell, W.J.; Houston, C.D.

    1982-10-01

    Separex Corp., through its subsidiary, Spectrum Separations, Inc., initiated work on membrane gas separation in 1979. Since that time, Spectrum has developed a cellulose acetate membrane and membrane element that exhibit greater selectivity and higher permeation rates for gas separations of commerical interest than previously found. These elements, when inserted into pipes, become part of a modular system capable of processing a wide range of feed flow rates. Up to 6 elements are connected in series in a single, 22-ft (6.7-m) long pipe or tube. A rubber U-cup attached to the element serves to seal the element with the inner diameter of the pressure tube, thereby forcing the feed gas to flow through the element. The pressure tubes usually contain 6 elements each and are mounted in racks on a skid. Commercial-size elements are typically 8 in. (203 mm) in diam by 42 in. (1070 mm) long and contain from 150 to 275 sq ft (14 to 26 sq m) of membrane area.

  20. Ionic liquids in chromatographic and electrophoretic techniques: toward additional improvements in the separation of natural compounds

    PubMed Central

    Freire, Carmen S. R.; Coutinho, João A. P.; Silvestre, Armando J. D.; Freire, Mara G.

    2016-01-01

    Due to their unique properties, in recent years, ionic liquids (ILs) have been largely investigated in the field of analytical chemistry. Particularly during the last sixteen years, they have been successfully applied in the chromatographic and electrophoretic analysis of value-added compounds extracted from biomass. Considering the growing interest in the use of ILs in this field, this critical review provides a comprehensive overview on the improvements achieved using ILs as constituents of mobile or stationary phases in analytical techniques, namely in capillary electrophoresis and its different modes, in high performance liquid chromatography, and in gas chromatography, for the separation and analysis of natural compounds. The impact of the IL chemical structure and the influence of secondary parameters, such as the IL concentration, temperature, pH, voltage and analysis time (when applied), are also critically addressed regarding the achieved separation improvements. Major conclusions on the role of ILs in the separation mechanisms and the performance of these techniques in terms of efficiency, resolution and selectivity are provided. Based on a critical analysis of all published results, some target-oriented ILs are suggested. Finally, current drawbacks and future challenges in the field are highlighted. In particular, the design and use of more benign and effective ILs as well as the development of integrated (and thus more sustainable) extraction–separation processes using IL aqueous solutions are suggested within a green chemistry perspective. PMID:27667965

  1. Ionic liquids in chromatographic and electrophoretic techniques: toward additional improvements in the separation of natural compounds.

    PubMed

    Soares, Belinda; Passos, Helena; Freire, Carmen S R; Coutinho, João A P; Silvestre, Armando J D; Freire, Mara G

    2016-09-07

    Due to their unique properties, in recent years, ionic liquids (ILs) have been largely investigated in the field of analytical chemistry. Particularly during the last sixteen years, they have been successfully applied in the chromatographic and electrophoretic analysis of value-added compounds extracted from biomass. Considering the growing interest in the use of ILs in this field, this critical review provides a comprehensive overview on the improvements achieved using ILs as constituents of mobile or stationary phases in analytical techniques, namely in capillary electrophoresis and its different modes, in high performance liquid chromatography, and in gas chromatography, for the separation and analysis of natural compounds. The impact of the IL chemical structure and the influence of secondary parameters, such as the IL concentration, temperature, pH, voltage and analysis time (when applied), are also critically addressed regarding the achieved separation improvements. Major conclusions on the role of ILs in the separation mechanisms and the performance of these techniques in terms of efficiency, resolution and selectivity are provided. Based on a critical analysis of all published results, some target-oriented ILs are suggested. Finally, current drawbacks and future challenges in the field are highlighted. In particular, the design and use of more benign and effective ILs as well as the development of integrated (and thus more sustainable) extraction-separation processes using IL aqueous solutions are suggested within a green chemistry perspective.

  2. A millisecond micro-RNA separation technique by a hybrid structure of nanopillars and nanoslits

    PubMed Central

    Wu, Qiong; Kaji, Noritada; Yasui, Takao; Rahong, Sakon; Yanagida, Takeshi; Kanai, Masaki; Nagashima, Kazuki; Tokeshi, Manabu; Kawai, Tomoji; Baba, Yoshinobu

    2017-01-01

    A millisecond micro-RNA separation of a mixture of total RNA and genomic DNA, extracted from cultured HeLa cells, was successfully achieved using a hybrid structure of nanopillars and nanoslits contained inside a microchannel. The nanopillars, 250-nm in diameter and 100-nm in height, were fabricated with a 750-nm space inside the nanoslits, which were 100-nm in height and 25-μm in width; the nanopillars were then applied as a new sieve matrix. This ultra-fast technique for the separation of miRNA can be an effective pretreatment for semiconductor nanopore DNA sequencing, which has an optimum reading speed of 1 base/ms to obtain effective signal-to-noise ratio and discriminate each base by ion or tunneling current during the passage of nucleic acids. PMID:28272420

  3. A millisecond micro-RNA separation technique by a hybrid structure of nanopillars and nanoslits.

    PubMed

    Wu, Qiong; Kaji, Noritada; Yasui, Takao; Rahong, Sakon; Yanagida, Takeshi; Kanai, Masaki; Nagashima, Kazuki; Tokeshi, Manabu; Kawai, Tomoji; Baba, Yoshinobu

    2017-03-08

    A millisecond micro-RNA separation of a mixture of total RNA and genomic DNA, extracted from cultured HeLa cells, was successfully achieved using a hybrid structure of nanopillars and nanoslits contained inside a microchannel. The nanopillars, 250-nm in diameter and 100-nm in height, were fabricated with a 750-nm space inside the nanoslits, which were 100-nm in height and 25-μm in width; the nanopillars were then applied as a new sieve matrix. This ultra-fast technique for the separation of miRNA can be an effective pretreatment for semiconductor nanopore DNA sequencing, which has an optimum reading speed of 1 base/ms to obtain effective signal-to-noise ratio and discriminate each base by ion or tunneling current during the passage of nucleic acids.

  4. Separation techniques: membranes for natural gas sweetening and CO/sub 2/ enrichment

    SciTech Connect

    Mazur, W.H.; Chan, M.C.

    1982-10-01

    The ability of polymeric membranes to separate gases has been poor since the 19th century. Early polymeric membranes showed poor selectivity (separation); even the most permeable of gases exhibited poor productivities (fluxes). Due to the inability to perfect a process to produce uniformly good membranes in quantity, practical industrial gas separation systems were not successful. In 1960, a technical breakthrough came with the development of asymmetric membranes for reverse osmosis and their subsequent adaptation to gaseous separation. Based upon development and commercialization of membranes for water desalination by reverse osmosis, Envirogenics Systems Co. has developed gas separation membranes suitable for large-scale industrial applications. The cellulose acetate membrane is produced in flat sheet form and to retain its asymmetric character the membrane is heat-treated and dried by proprietary techniques. This produces a highly selective, dense, active layer with a thick porous support layer having high mechanical stability to withstand high feed gas pressures and high pressure differentials. The membrane is incorporated into spiral-wound elements similar to those for reverse osmosis applications. The membrane, which has been field tested for sweetening natural gas, also can be used for enhanced oil recovery and oxygen enrichment.

  5. A temporally constrained ICA (TCICA) technique for artery-vein separation of cerebral microvasculature

    NASA Astrophysics Data System (ADS)

    Mehrabian, Hatef; Lindvere, Liis; Stefanovic, Bojana; Martel, Anne L.

    2010-03-01

    A fully automatic ICA based data driven technique which incorporates additional a priori information from physiological modeling of the cerebral microcirculation (gamma variate model) is developed for the separation of arteries and veins in contrast-enhanced studies of the cerebral microvasculature. A dynamic data set of 50 images taken by a two-photon laser scanning microscopy technique that monitors the passage of a bolus of dye through artery and vein is used here. A temporally constrained ICA (TCICA) technique is developed to extract the vessel specific dynamics of artery and vein by adding two constraints to classical ICA algorithm. One of the constraints guarantees that the extracted curves follow the gamma variate model of blood passage through vessels. Positivity as the second constraint indicates that none of the extracted component images that correspond to the artery, vein or other capillaries in the imaging field of view, has negative impact on the acquired images. Experimental results show improved performance of the proposed temporally constrained ICA (TCICA) over the most commonly used classical ICA technique (fast-ICA) in generating physiologically meaningful curves; they are also closer to that of pixel by pixel model fitting algorithms and perform better in handling noise. This technique is also fully automatic and does not require specifying regions of interest which is critical in model based techniques.

  6. Bibliography of articles and reports on mineral-separation techniques, processes, and applications

    NASA Technical Reports Server (NTRS)

    Harmon, R. S.

    1971-01-01

    A bibliography of published articles and reports on mineral-separation techniques, processes, and applications is presented along with an author and subject index. This information is intended for use in the mineral-separation facility of the Lunar Receiving Laboratory at the NASA Manned Spacecraft Center and as an aid and reference to persons involved or interested in mineral separation.

  7. Techniques of preparing plant material for chromatographic separation and analysis.

    PubMed

    Romanik, G; Gilgenast, E; Przyjazny, A; Kamiński, M

    2007-03-10

    This paper discusses preparation techniques of samples of plant material for chromatographic analysis. Individual steps of the procedures used in sample preparation, including sample collection from the environment or from tissue cultures, drying, comminution, homogenization, leaching, extraction, distillation and condensation, analyte enrichment, and obtaining the final extracts for chromatographic analysis are discussed. The techniques most often used for isolation of analytes from homogenized plant material, i.e., Soxhlet extraction, ultrasonic solvent extraction (sonication), accelerated solvent extraction, microwave-assisted extraction, supercritical-fluid extraction, steam distillation, as well as membrane processes are emphasized. Sorptive methods of sample enrichment and removal of interferences, i.e., solid-phase extraction, and solid-phase micro-extraction are also discussed.

  8. Complementary home mechanical ventilation techniques. SEPAR Year 2014.

    PubMed

    Chiner, Eusebi; Sancho-Chust, José N; Landete, Pedro; Senent, Cristina; Gómez-Merino, Elia

    2014-12-01

    This is a review of the different complementary techniques that are useful for optimizing home mechanical ventilation (HMV). Airway clearance is very important in patients with HMV and many patients, particularly those with reduced peak cough flow, require airway clearance (manual or assisted) or assisted cough techniques (manual or mechanical) and suctioning procedures, in addition to ventilation. In the case of invasive HMV, good tracheostomy cannula management is essential for success. HMV patients may have sleep disturbances that must be taken into account. Sleep studies including complete polysomnography or respiratory polygraphy are helpful for identifying patient-ventilator asynchrony. Other techniques, such as bronchoscopy or nutritional support, may be required in patients on HMV, particularly if percutaneous gastrostomy is required. Information on treatment efficacy can be obtained from HMV monitoring, using methods such as pulse oximetry, capnography or the internal programs of the ventilators themselves. Finally, the importance of the patient's subjective perception is reviewed, as this may potentially affect the success of the HMV.

  9. Interactions Between Antigens and Nanoemulsion Adjuvants: Separation and Characterization Techniques.

    PubMed

    Chan, Michelle Y; Fedor, Dawn M; Phan, Tony; V, Lucien Barnes; Kramer, Ryan M

    2017-01-01

    Determining the association of vaccine components in a formulation is of interest for designing and optimizing well characterized vaccines. Three methods are described to assess interactions between protein antigens and oil-in-water nanoemulsion adjuvants. The methods include (1) ultracentrifugation to measure free versus adjuvant-associated protein, (2) size exclusion chromatography (SEC) to qualitatively assess existing interactions, and (3) Native PAGE as a means to visualize the formulation run in its native state on a polyacrylamide gel. As with many techniques, the methods alone are not definitive, but data from multiple orthogonal assays can provide a more complete picture of protein-adjuvant interactions.

  10. Mode separation of Lamb waves based on dispersion compensation method.

    PubMed

    Xu, Kailiang; Ta, Dean; Moilanen, Petro; Wang, Weiqi

    2012-04-01

    Ultrasonic Lamb modes typically propagate as a combination of multiple dispersive wave packets. Frequency components of each mode distribute widely in time domain due to dispersion and it is very challenging to separate individual modes by traditional signal processing methods. In the present study, a method of dispersion compensation is proposed for the purpose of mode separation. This numerical method compensates, i.e., compresses, the individual dispersive waveforms into temporal pulses, which thereby become nearly un-overlapped in time and frequency and can thus be extracted individually by rectangular time windows. It was further illustrated that the dispersion compensation also provided a method for predicting the plate thickness. Finally, based on reversibility of the numerical compensation method, an artificial dispersion technique was used to restore the original waveform of each mode from the separated compensated pulse. Performances of the compensation separation techniques were evaluated by processing synthetic and experimental signals which consisted of multiple Lamb modes with high dispersion. Individual modes were extracted with good accordance with the original waveforms and theoretical predictions.

  11. Atmospheric Pressure Surface Sampling/Ionization Techniques for Direct Coupling of Planar Separations with Mass Spectrometry

    SciTech Connect

    Pasilis, Sofie P; Van Berkel, Gary J

    2010-01-01

    Planar separations, which include thin layer chromatography and gel electrophoresis, are in widespread use as important and powerful tools for conducting separations of complex mixtures. To increase the utility of planar separations, new methods are needed that allow in-situ characterization of the individual components of the separated mixtures. A large number of atmospheric pressure surface sampling and ionization techniques for use with mass spectrometry have emerged in the past several years, and several have been investigated as a means for mass spectrometric read-out of planar separations. In this article, we review the atmospheric pressure surface sampling and ionization techniques that have been used for the read-out of planar separation media. For each technique, we briefly explain the operational basics and discuss the analyte type for which it is appropriate and some specific applications from the literature.

  12. Residual matrix from different separation techniques impacts exosome biological activity

    PubMed Central

    Paolini, Lucia; Zendrini, Andrea; Noto, Giuseppe Di; Busatto, Sara; Lottini, Elisabetta; Radeghieri, Annalisa; Dossi, Alessandra; Caneschi, Andrea; Ricotta, Doris; Bergese, Paolo

    2016-01-01

    Exosomes are gaining a prominent role in research due to their intriguing biology and several therapeutic opportunities. However, their accurate purification from body fluids and detailed physicochemical characterization remain open issues. We isolated exosomes from serum of patients with Multiple Myeloma by four of the most popular purification methods and assessed the presence of residual contaminants in the preparations through an ad hoc combination of biochemical and biophysical techniques - including Western Blot, colloidal nanoplasmonics, atomic force microscopy (AFM) and scanning helium ion microscopy (HIM). The preparations obtained by iodixanol and sucrose gradients were highly pure. To the contrary, those achieved with limited processing (serial centrifugation or one step precipitation kit) resulted contaminated by a residual matrix, embedding the exosomes. The contaminated preparations showed lower ability to induce NfkB nuclear translocation in endothelial cells with respect to the pure ones, probably because the matrix prevents the interaction and fusion of the exosomes with the cell membrane. These findings suggest that exosome preparation purity must be carefully assessed since it may interfere with exosome biological activity. Contaminants can be reliably probed only by an integrated characterization approach aimed at both the molecular and the colloidal length scales. PMID:27009329

  13. Characterization and separation of ash from CANMET coprocessing residue by oil phase agglomeration techniques

    SciTech Connect

    Majid, A.; Coleman, R.D.; Toll, R.; Pleizier, G.; Deslandes, Y.; Sparks, B.D.; Ikura, M.

    1993-12-31

    CANMET`s coal/heavy oil coprocessing unit yields a solid residue that contains most of the ash originally associated with the feed coal as well as reacted catalyst solids. Removal of these ash solids would make it possible to recycle the material to extinction, thereby increasing production of lighter oils. In this investigation the authors have used surface characterization techniques such as Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Analysis (EDXA) and X-ray Photoelectron Spectroscopy (XPS) to characterize toluene insoluble solids associated with the pitch residue, in order to evaluate the separation potential using oil phase agglomeration techniques. Washability studies using float-sink tests were also carried out to determine empirically the level of ash separation attainable. Based on the results of these studies several tests were carried out to beneficiate the organic matter in the residue pitch, by using liquid phase agglomeration techniques. Levels of ash rejection in these tests ranged from 20% to 40%. SEM and EDXA analysis of the agglomerated product and the reject material and Inductively Coupled Plasma (ICP) analysis of the ash from both materials suggest that most of the iron from added catalyst is retained in the agglomerates.

  14. Fast centrifugal partition chromatography as a preparative-scale separation technique for citrus flavones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fast centrifugal partition chromatography (FCPC) is a preparative-scale separations methodology based on the principles of counter current chromatography. Separations by FCPC are typically achieved with higher recoveries and with lower solvent use compared to conventional column chromatography. HSCP...

  15. Electrical field-induced extraction and separation techniques: promising trends in analytical chemistry--a review.

    PubMed

    Yamini, Yadollah; Seidi, Shahram; Rezazadeh, Maryam

    2014-03-03

    Sample preparation is an important issue in analytical chemistry, and is often a bottleneck in chemical analysis. So, the major incentive for the recent research has been to attain faster, simpler, less expensive, and more environmentally friendly sample preparation methods. The use of auxiliary energies, such as heat, ultrasound, and microwave, is one of the strategies that have been employed in sample preparation to reach the above purposes. Application of electrical driving force is the current state-of-the-art, which presents new possibilities for simplifying and shortening the sample preparation process as well as enhancing its selectivity. The electrical driving force has scarcely been utilized in comparison with other auxiliary energies. In this review, the different roles of electrical driving force (as a powerful auxiliary energy) in various extraction techniques, including liquid-, solid-, and membrane-based methods, have been taken into consideration. Also, the references have been made available, relevant to the developments in separation techniques and Lab-on-a-Chip (LOC) systems. All aspects of electrical driving force in extraction and separation methods are too specific to be treated in this contribution. However, the main aim of this review is to provide a brief knowledge about the different fields of analytical chemistry, with an emphasis on the latest efforts put into the electrically assisted membrane-based sample preparation systems. The advantages and disadvantages of these approaches as well as the new achievements in these areas have been discussed, which might be helpful for further progress in the future.

  16. [Evidence-based TEP technique].

    PubMed

    Köckerling, F

    2017-01-13

    The guidelines of all international hernia societies recommend as procedures of choice the laparoendoscopic techniques total extraperitoneal patch plasty (TEP) and transabdominal preperitoneal patch plasty (TAPP) as well as the open Lichtenstein operation for elective inguinal hernia repair. The learning curve associated with the laparoendoscopic techniques, in particular TEP, is longer than that for the open Lichtenstein technique due to the complexity of the procedures. Accordingly, for laparoendoscopic techniques it is particularly important that the operations are conducted in a standardized manner in compliance with the evidence-based recommendations given for the technical details. When procedures are carried out in strict compliance with the guidelines of the international hernia societies, low rates of perioperative complications, complication-related reoperations, recurrences and chronic pain can be expected for TEP. Compliance with the guidelines can also positively impact mastery of the learning curve for TEP. The technical guidelines on TEP are based on study results and on the experiences of numerous experts; therefore, it is imperative that they are implemented in routine surgical practice.

  17. Separator Reconnection at the Magnetopause for Predominantly Northward and Southward IMF: Techniques and Results

    NASA Technical Reports Server (NTRS)

    Glocer, Alex; Dorelli, J.; Toth, G.; Komar, C. M.; Cassak, P. A.

    2016-01-01

    In this work, we demonstrate how to track magnetic separators in three-dimensional simulated magnetic fields with or without magnetic nulls, apply these techniques to enhance our understanding of reconnection at the magnetopause. We present three methods for locating magnetic separators and apply them to 3-D resistive MHD simulations of the Earth's magnetosphere using the Block-Adaptive-Tree Solar-wind Roe-type Upwind Scheme code. The techniques for finding separators and determining the reconnection rate are insensitive to interplanetary magnetic field (IMF) clock angle and can in principle be applied to any magnetospheric model. Moreover, the techniques have a number of advantages over prior separator finding techniques applied to the magnetosphere. The present work examines cases of high and low resistivity for two clock angles. We go beyond previous work examine the separator during Flux Transfer Events (FTEs). Our analysis of reconnection on the magnetopause yields a number of interesting conclusions: Reconnection occurs all along the separator even during predominately northward IMF cases. Multiple separators form in low-resistivity conditions, and in the region of an FTE the separator splits into distinct branches. Moreover, the local contribution to the reconnection rate, as determined by the local parallel electric field, drops in the vicinity of the FTE with respect to the value when there are none.

  18. Comparison Between Digital and Analog Pulse Shape Discrimination Techniques For Neutron and Gamma Ray Separation

    SciTech Connect

    R. Aryaeinejad; John K. Hartwell

    2005-11-01

    Recent advancement in digital signal processing (DSP) using fast processors and computer makes it possible to be used in pulse shape discrimination applications. In this study, we have investigated the feasibility of using a DSP to distinguish between the neutrons and gamma rays by the shape of their pulses in a liquid scintillator detector (BC501), and have investigated pulse shape-based techniques to improve the resolution performance of room-temperature cadmium zinc telluride (CZT) detectors. For the neutron/gamma discrimination, the advantage of using a DSP over the analog method is that in analog system two separate charge-sensitive ADC's are required. One ADC is used to integrate the beginning of the pulse risetime while the second ADC is for integrating the tail part. Using a DSP eliminates the need for separate ADCs as one can easily get the integration of two parts of the pulse from the digital waveforms. This work describes the performance of these DSP techniques and compares the results with the analog method.

  19. Structural characterization of bacterial lipopolysaccharides with mass spectrometry and on- and off-line separation techniques.

    PubMed

    Kilár, Anikó; Dörnyei, Ágnes; Kocsis, Béla

    2013-01-01

    The focus of this review is the application of mass spectrometry to the structural characterization of bacterial lipopolysaccharides (LPSs), also referred to as "endotoxins," because they elicit the strong immune response in infected organisms. Recently, a wide variety of MS-based applications have been implemented to the structure elucidation of LPS. Methodological improvements, as well as on- and off-line separation procedures, proved the versatility of mass spectrometry to study complex LPS mixtures. Special attention is given in the review to the tandem mass spectrometric methods and protocols for the analyses of lipid A, the endotoxic principle of LPS. We compare and evaluate the different ionization techniques (MALDI, ESI) in view of their use in intact R- and S-type LPS and lipid A studies. Methods for sample preparation of LPS prior to mass spectrometric analysis are also described. The direct identification of intrinsic heterogeneities of most intact LPS and lipid A preparations is a particular challenge, for which separation techniques (e.g., TLC, slab-PAGE, CE, GC, HPLC) combined with mass spectrometry are often necessary. A brief summary of these combined methodologies to profile LPS molecular species is provided.

  20. Battery Separators Based on Polyphenylquinoxaline Polymer Blends.

    DTIC Science & Technology

    1981-04-01

    concluded that PPQ/ Cellulose Acetate is a good candidate material for alkaline battery separators; however, because of cost considerations, it is not competative with similar state-of-the-art materials. (Author)

  1. Computational techniques for aerodynamic simulations of multiple objects emphasizing paratrooper-aircraft separation

    NASA Astrophysics Data System (ADS)

    Udoewa, Victor

    Our target is to develop computational techniques for studying aerodynamic interactions between multiple objects with emphasis on studying the fluid mechanics and dynamics of an object exiting and separating from an aircraft. The object could be a paratrooper jumping out of a transport aircraft or a package of emergency aid dropped from a cargo plane. These are applications with major practical significance, and what I learn and what I develop can make a major impact on this technology area. In all these cases, the computational challenge is to predict the dynamic behavior and path of the object, so that the separation process is safe and effective. This is a very complex problem because it has an unsteady, three-dimensional nature and requires the solution of complex equations that govern the fluid dynamics of the object and the aircraft together, with their relative positions changing in time. The gravitational and aerodynamic forces acting on the object determine its dynamics and path. Sometimes those aerodynamic forces are not properly computed due to excessively thick numerical boundary layers (numerical meaning unphysical and unreal). Methods for reducing this thickness are presented here. The aerodynamic forces heavily depend on the unsteady flow field around the aircraft. The computational tools I am developing are based on the simultaneous solution of the time-dependent Navier-Stokes equations governing the airflow around the aircraft and the separating object, as well as the equations governing the motion of that object. These computational methods include suitable mesh update techniques that are essential for simulations with my core computational technique---the Deforming-Spatial-Domain/Stabilized Space-Time (DSD/SST) formulation. In the research I present here, I focus on developing mesh update methods that help me perform my computations with more numerical accuracy and better computational efficiency. These methods range from remeshing tactics with

  2. Digital microfluidic magnetic separation for particle-based immunoassays.

    PubMed

    Ng, Alphonsus H C; Choi, Kihwan; Luoma, Robert P; Robinson, John M; Wheeler, Aaron R

    2012-10-16

    We introduce a new format for particle-based immunoassays relying on digital microfluidics (DMF) and magnetic forces to separate and resuspend antibody-coated paramagnetic particles. In DMF, fluids are electrostatically controlled as discrete droplets (picoliters to microliters) on an array of insulated electrodes. By applying appropriate sequences of potentials to these electrodes, multiple droplets can be manipulated simultaneously and various droplet operations can be achieved using the same device design. This flexibility makes DMF well-suited for applications that require complex, multistep protocols such as immunoassays. Here, we report the first particle-based immunoassay on DMF without the aid of oil carrier fluid to enable droplet movement (i.e., droplets are surrounded by air instead of oil). This new format allowed the realization of a novel on-chip particle separation and resuspension method capable of removing greater than 90% of unbound reagents in one step. Using this technique, we developed methods for noncompetitive and competitive immunoassays, using thyroid stimulating hormone (TSH) and 17β-estradiol (E2) as model analytes, respectively. We show that, compared to conventional methods, the new DMF approach reported here reduced reagent volumes and analysis time by 100-fold and 10-fold, respectively, while retaining a level of analytical performance required for clinical screening. Thus, we propose that the new technique has great potential for eventual use in a fast, low-waste, and inexpensive instrument for the quantitative analysis of proteins and small molecules in low sample volumes.

  3. Membrane-based technologies for biogas separations.

    PubMed

    Basu, Subhankar; Khan, Asim L; Cano-Odena, Angels; Liu, Chunqing; Vankelecom, Ivo F J

    2010-02-01

    Over the past two decades, membrane processes have gained a lot of attention for the separation of gases. They have been found to be very suitable for wide scale applications owing to their reasonable cost, good selectivity and easily engineered modules. This critical review primarily focuses on the various aspects of membrane processes related to the separation of biogas, more in specific CO(2) and H(2)S removal from CH(4) and H(2) streams. Considering the limitations of inorganic materials for membranes, the present review will only focus on work done with polymeric materials. An overview on the performance of commercial membranes and lab-made membranes highlighting the problems associated with their applications will be given first. The development studies carried out to enhance the performance of membranes for gas separation will be discussed in the subsequent section. This review has been broadly divided into three sections (i) performance of commercial polymeric membranes (ii) performance of lab-made polymeric membranes and (iii) performance of mixed matrix membranes (MMMs) for gas separations. It will include structural modifications at polymer level, polymer blending, as well as synthesis of mixed matrix membranes, for which addition of silane-coupling agents and selection of suitable fillers will receive special attention. Apart from an overview of the different membrane materials, the study will also highlight the effects of different operating conditions that eventually decide the performance and longevity of membrane applications in gas separations. The discussion will be largely restricted to the studies carried out on polyimide (PI), cellulose acetate (CA), polysulfone (PSf) and polydimethyl siloxane (PDMS) membranes, as these membrane materials have been most widely used for commercial applications. Finally, the most important strategies that would ensure new commercial applications will be discussed (156 references).

  4. 5 CFR 831.503 - Retirement based on involuntary separation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... separation. 831.503 Section 831.503 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... involuntary separation. (a) General. An employee who would otherwise be eligible for retirement based on involuntary separation from the service is not entitled to an annuity under section 8336(d)(1) of title...

  5. 5 CFR 831.503 - Retirement based on involuntary separation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... separation. 831.503 Section 831.503 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... involuntary separation. (a) General. An employee who would otherwise be eligible for retirement based on involuntary separation from the service is not entitled to an annuity under section 8336(d)(1) of title...

  6. 5 CFR 831.503 - Retirement based on involuntary separation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... separation. 831.503 Section 831.503 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... involuntary separation. (a) General. An employee who would otherwise be eligible for retirement based on involuntary separation from the service is not entitled to an annuity under section 8336(d)(1) of title...

  7. 5 CFR 831.503 - Retirement based on involuntary separation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... separation. 831.503 Section 831.503 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... involuntary separation. (a) General. An employee who would otherwise be eligible for retirement based on involuntary separation from the service is not entitled to an annuity under section 8336(d)(1) of title...

  8. 5 CFR 831.503 - Retirement based on involuntary separation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... separation. 831.503 Section 831.503 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL... involuntary separation. (a) General. An employee who would otherwise be eligible for retirement based on involuntary separation from the service is not entitled to an annuity under section 8336(d)(1) of title...

  9. Reprocessing system with nuclide separation based on chromatography in hydrochloric acid solution

    SciTech Connect

    Suzuki, Tatsuya; Tachibana, Yu; Koyama, Shi-ichi

    2013-07-01

    We have proposed the reprocessing system with nuclide separation processes based on the chromatographic technique in the hydrochloric acid solution system. Our proposed system consists of the dissolution process, the reprocessing process, the minor actinide separation process, and nuclide separation processes. In the reprocessing and separation processes, the pyridine resin is used as a main separation media. It was confirmed that the dissolution in the hydrochloric acid solution is easily achieved by the plasma voloxidation and by the addition of oxygen peroxide into the hydrochloric acid solution.

  10. Clusius-Dickel Separations (CDS): A new look at an old technique

    NASA Technical Reports Server (NTRS)

    Grodzka, P. G.

    1975-01-01

    The history, applications, and theoretical basis of the CDS technique are reviewed. The advantage to be realized by conduction of CDSs in low-g, space environments are deduced. The results are reported of investigations aimed at further improving CDS efficiencies by altering convective flow patterns. The question of whether multicellular flow or turbulence can introduce a new separation mechanism which would boost separation efficiencies at least an order of magnitude is considered. Results are presented and discussed.

  11. The use of extrapolation concepts to augment the Frequency Separation Technique

    NASA Astrophysics Data System (ADS)

    Alexiou, Spiros

    2015-03-01

    The Frequency Separation Technique (FST) is a general method formulated to improve the speed and/or accuracy of lineshape calculations, including strong overlapping collisions, as is the case for ion dynamics. It should be most useful when combined with ultrafast methods, that, however have significant difficulties when the impact regime is approached. These difficulties are addressed by the Frequency Separation Technique, in which the impact limit is correctly recovered. The present work examines the possibility of combining the Frequency Separation Technique with the addition of extrapolation to improve results and minimize errors resulting from the neglect of fast-slow coupling and thus obtain the exact result with a minimum of extra effort. To this end the adequacy of one such ultrafast method, the Frequency Fluctuation Method (FFM) for treating the nonimpact part is examined. It is found that although the FFM is unable to reproduce the nonimpact profile correctly, its coupling with the FST correctly reproduces the total profile.

  12. Charge separation technique for metal-oxide-silicon capacitors in the presence of hydrogen deactivated dopants

    SciTech Connect

    Witczak, Steven C.; Winokur, Peter S.; Lacoe, Ronald C.; Mayer, Donald C.

    2000-06-01

    An improved charge separation technique for metal-oxide-silicon (MOS) capacitors is presented which accounts for the deactivation of substrate dopants by hydrogen at elevated irradiation temperatures or small irradiation biases. Using high-frequency capacitance-voltage measurements, radiation-induced inversion voltage shifts are separated into components due to oxide trapped charge, interface traps, and deactivated dopants, where the latter is computed from a reduction in Si capacitance. In the limit of no radiation-induced dopant deactivation, this approach reduces to the standard midgap charge separation technique used widely for the analysis of room-temperature irradiations. The technique is demonstrated on a p-type MOS capacitor irradiated with {sup 60}Co {gamma} rays at 100 degree sign C and zero bias, where the dopant deactivation is significant.(c) 2000 American Institute of Physics.

  13. Optimal separable bases and molecular collisions

    SciTech Connect

    Poirier, Lionel W.

    1997-12-01

    A new methodology is proposed for the efficient determination of Green`s functions and eigenstates for quantum systems of two or more dimensions. For a given Hamiltonian, the best possible separable approximation is obtained from the set of all Hilbert space operators. It is shown that this determination itself, as well as the solution of the resultant approximation, are problems of reduced dimensionality for most systems of physical interest. Moreover, the approximate eigenstates constitute the optimal separable basis, in the sense of self-consistent field theory. These distorted waves give rise to a Born series with optimized convergence properties. Analytical results are presented for an application of the method to the two-dimensional shifted harmonic oscillator system. The primary interest however, is quantum reactive scattering in molecular systems. For numerical calculations, the use of distorted waves corresponds to numerical preconditioning. The new methodology therefore gives rise to an optimized preconditioning scheme for the efficient calculation of reactive and inelastic scattering amplitudes, especially at intermediate energies. This scheme is particularly suited to discrete variable representations (DVR`s) and iterative sparse matrix methods commonly employed in such calculations. State to state and cumulative reactive scattering results obtained via the optimized preconditioner are presented for the two-dimensional collinear H + H2 → H2 + H system. Computational time and memory requirements for this system are drastically reduced in comparison with other methods, and results are obtained for previously prohibitive energy regimes.

  14. Stable isotope production in the former USSR by electromagnetic separation techniques

    NASA Astrophysics Data System (ADS)

    Kaschejev, N. A.; Polyakov, L. A.; Tunin, V. V.

    1993-09-01

    The present paper gives a brief review of the status of electromagnetic isotope separation techniques in the former USSR. It describes the basic specifications of the equipment as well as the general scheme of the production process, and considers questions relating to the chemical processing of isotopic material and analytical control techniques. Finally, a summary is given of the main separation data obtained during the last ten years, and the prospects of future development and of enhancing the economical effectiveness of isotope production are discussed.

  15. Development of separation techniques for a direct contact thermal energy storage system

    SciTech Connect

    Min, T.C.; Tomlinson, J.J.

    1989-03-01

    In direct contact ice-making processes, the refrigerant will pick up water vapor through direct percolation and oil from the compressor. The purpose of this project is to investigate methods for separating water vapor and oil from a mixture to complete a refrigeration cycle. In this paper, we report critical review on two separation techniques. From a literature search, we have identified a third technique; and plan to evaluate this method by bench-scale experiments. A recommendation for future work is included.

  16. Novel platform for minimizing cell loss on separation process: Droplet-based magnetically activated cell separator

    NASA Astrophysics Data System (ADS)

    Kim, Youngho; Hong, Su; Lee, Sang Ho; Lee, Kangsun; Yun, Seok; Kang, Yuri; Paek, Kyeong-Kap; Ju, Byeong-Kwon; Kim, Byungkyu

    2007-07-01

    To reduce the problem of cell loss due to adhesion, one of the basic phenomena in microchannel, we proposed the droplet-based magnetically activated cell separator (DMACS). Based on the platform of the DMACS—which consists of permanent magnets, a coverslip with a circle-shaped boundary, and an injection tube—we could collect magnetically (CD45)-labeled (positive) cells with high purity and minimize cell loss due to adhesion. To compare separation efficiency between the MACS and the DMACS, the total number of cells before and after separation with both the separators was counted by flow cytometry. We could find that the number (3241/59940) of cells lost in the DMACS is much less than that (22360/59940) in the MACS while the efficiency of cell separation in the DMACS (96.07%) is almost the same as that in the MACS (96.72%). Practically, with fluorescent images, it was visually confirmed that the statistical data are reliable. From the viability test by using Hoechst 33 342, it was also demonstrated that there was no cell damage on a gas-liquid interface. Conclusively, DMACS will be a powerful tool to separate rare cells and applicable as a separator, key component of lab-on-a-chip.

  17. A Practical Introduction to Separation and Purification Techniques for the Beginning Organic Chemistry Laboratory.

    ERIC Educational Resources Information Center

    Leonard, Jack E.

    1981-01-01

    Describes a sequence of experiments developed at Texas A&M University for use in one-semester and two-semester (nonmajors) organic chemistry courses to teach a maximum number of separation and purification techniques such as distillations, recrystallization, liquid-liquid extraction, and chromatography. (SK)

  18. Anxiety: the importunate companion. Psychoanalytic theory of castration and separation anxieties and implications for clinical technique.

    PubMed

    Davies, Rosemary

    2012-10-01

    In this article I consider the implications of our differing psychoanalytic theories of anxiety on clinical technique. Drawing on differentiations between the focus on separation or castration anxiety and the relative neglect of the latter in contemporary writing, I look in detail at two clinical examples of psychoanalysis in borderline young adults to exemplify the issue.(1).

  19. Calibration of base flow separation methods with streamflow conductivity.

    PubMed

    Stewart, Mark; Cimino, Joseph; Ross, Mark

    2007-01-01

    The conductivity mass-balance (CMB) method can be used to calibrate analytical base flow separation methods. The principal CMB assumptions are base flow conductivity is equal to streamflow conductivity at lowest flows, runoff conductivity is equal to streamflow conductivity at highest flows, and base flow and runoff conductivities are assumed to be constants over the period of record. To test the CMB assumptions, fluid conductivities of ground water, surface runoff, and streamflow were measured during wet and dry conditions in a 12-km(2) stream basin. Ground water conductivities at wells varied an average of 6% from dry to wet conditions, while stream conductivities varied 58%. Shallow ground water conductivity varied significantly with distance from the stream, with lowest conductivities of 87 microS/cm near the divide, a maximum of 520 microS/cm 59 m from the stream, and 215 microS/cm 22 m from the stream. Runoff conductivities measured in three rain events remained nearly constant, with lower conductivities of 35 microS/cm near the divide and 50 microS/cm near the stream. The CMB method was applied to the records from 10 USGS stream-gauging stations in Texas, Kentucky, Georgia, and Florida to calibrate the USGS base flow separation technique, HYSEP, by varying the time parameter 2N*. There is a statistically significant relationship between basin areas and calibrated values of 2N*, expressed as N = 0.46A(0.44), with N in days and A in km(2). The widely accepted relationship N = 0.83A(0.2) is not valid for these basins. Other analytic methods can also be calibrated with the CMB method.

  20. Conceptual design of distillation-based hybrid separation processes.

    PubMed

    Skiborowski, Mirko; Harwardt, Andreas; Marquardt, Wolfgang

    2013-01-01

    Hybrid separation processes combine different separation principles and constitute a promising design option for the separation of complex mixtures. Particularly, the integration of distillation with other unit operations can significantly improve the separation of close-boiling or azeotropic mixtures. Although the design of single-unit operations is well understood and supported by computational methods, the optimal design of flowsheets of hybrid separation processes is still a challenging task. The large number of operational and design degrees of freedom requires a systematic and optimization-based design approach. To this end, a structured approach, the so-called process synthesis framework, is proposed. This article reviews available computational methods for the conceptual design of distillation-based hybrid processes for the separation of liquid mixtures. Open problems are identified that must be addressed to finally establish a structured process synthesis framework for such processes.

  1. ICA-based UHF RFID multi-tag hybrid data blind separation

    NASA Astrophysics Data System (ADS)

    Li, Hua; Wang, Hong-jun; Song, Zi-liang

    2013-03-01

    This work presents an ICA-based UHF RFID multi-tag hybrid data blind separation algorithm. After analysis, we find that UHF RFID multi-tag hybrid data is consistent with the requirements of ICA algorithm. Simulated experimental results show that excellent results can be obtained by using ICA techniques in blind separating of tags data. For evaluating the separation performance objectively, a new indicator- the Similarity of Sources and Results (SSR) is defined. The anti- noise performance of this algorithm is analyzed quantitatively too. A good theoretical and experimental basis for applying blind separation technology to UHF RFID tags anti-collision algorithm has been established in this paper.

  2. Development of Techniques for Separating Waterproof Layer from XLPE Cable Sheath by Hot Water Heating

    NASA Astrophysics Data System (ADS)

    Okazaki, Masato; Nakade, Masahiko; Okashita, Minoru; Tanimoto, Mihoko

    Waterproof layer is used to prevent penetration of water which is one of the factors of dielectric breakdown in XLPE cables more than 66kV class. A XLPE cable sheath with waterproof layer is done landfill disposal as industrial waste because separation of waterproof layer is difficult for technology and cost. However, around 20 years passes after waterproof layer was introduced, and social consciousness for environment changes during these 20 years, and responsibility of company for environment of a society grows bigger. We report the result that examined techniques for separating waterproof layer.

  3. Review of chemometric analysis techniques for comprehensive two dimensional separations data.

    PubMed

    Pierce, Karisa M; Kehimkar, Benjamin; Marney, Luke C; Hoggard, Jamin C; Synovec, Robert E

    2012-09-14

    Comprehensive two-dimensional (2D) separations, such as comprehensive 2D gas chromatography (GC×GC), liquid chromatography (LC×LC), and related instrumental techniques, provide very large and complex data sets. It is often up to the software to assist the analyst in transforming these complex data sets into useful information, and that is precisely where the field of chemometric data analysis plays a pivotal role. Chemometric tools for comprehensive 2D separations are continually being developed and applied as researchers make significant advances in novel state-of-the-art algorithms and software, and as the commercial sector continues to provide user friendly chemometric software. In this review, we build upon previous reviews of this topic, by focusing primarily on advances that have been reported in the past five years. Most of the reports focus on instrumental platforms using GC×GC with either flame ionization detection (FID) or time-of-flight mass spectrometry (TOFMS) detection, or LC×LC with diode array absorbance detection (DAD). The review covers the following general topics: data preprocessing techniques, target analyte techniques, comprehensive nontarget analysis techniques, and software for chemometrics in multidimensional separations.

  4. Development of novel separation techniques for biological samples in capillary electrophoresis

    SciTech Connect

    Chang, Huan -Tsung

    1994-07-27

    This dissertation includes three different topics: general introduction of capillary electrophoresis (CE); gradient in CE and CE in biological separations; and capillary gel electrophoresis (CGE) for DNA separation. Factors such as temperature, viscosity, pH, and the surface of capillary walls affecting the separation performance are demonstrated. A pH gradient between 3.0 and 5.2 is useful to improve the resolution among eight different organic acids. A flow gradient due to the change in the concentration of surfactant, which is able to coat to the capillary wall to change the flow rate and its direction, is also shown as a good way to improve the resolution for organic compounds. A temperature gradient caused by joule heat is shown by voltage programming to enhance the resolution and shorten the separation time for several phenolic compounds. The author also shows that self-regulating dynamic control of electroosmotic flow in CE by simply running separation in different concentrations of surfactant has less matrix effect on the separation performance. One of the most important demonstrations in this dissertation is that the author proposes on-column reaction which gives several advantages including the use of a small amount of sample, low risk of contamination, and time saving and kinetic features. The author uses this idea with laser induced fluorescence (LIF) as a detection mode to detect an on-column digestion of sub-ng of protein. This technique also is applied to single cell analysis in the group.

  5. Carbon dioxide capture and separation techniques for advanced power generation point sources

    SciTech Connect

    Pennline, H.W.; Luebke, D.R.; Morsi, B.I.; Heintz, Y.J.; Jones, K.L.; Ilconich, J.B.

    2006-09-01

    The capture/separation step for carbon dioxide (CO2) from large-point sources is a critical one with respect to the technical feasibility and cost of the overall carbon sequestration scenario. For large-point sources, such as those found in power generation, the carbon dioxide capture techniques being investigated by the in-house research area of the National Energy Technology Laboratory possess the potential for improved efficiency and costs as compared to more conventional technologies. The investigated techniques can have wide applications, but the research has focused on capture/separation of carbon dioxide from flue gas (postcombustion from fossil fuel-fired combustors) and from fuel gas (precombustion, such as integrated gasification combined cycle – IGCC). With respect to fuel gas applications, novel concepts are being developed in wet scrubbing with physical absorption; chemical absorption with solid sorbents; and separation by membranes. In one concept, a wet scrubbing technique is being investigated that uses a physical solvent process to remove CO2 from fuel gas of an IGCC system at elevated temperature and pressure. The need to define an ideal solvent has led to the study of the solubility and mass transfer properties of various solvents. Fabrication techniques and mechanistic studies for hybrid membranes separating CO2 from the fuel gas produced by coal gasification are also being performed. Membranes that consist of CO2-philic silanes incorporated into an alumina support or ionic liquids encapsulated into a polymeric substrate have been investigated for permeability and selectivity. An overview of two novel techniques is presented along with a research progress status of each technology.

  6. Separation of oil-water-sludge emulsions coming from palm oil mill process through microwave techniques.

    PubMed

    Pérez-Páez, Rocío; Catalá-Civera, José Manuel; García-Baños, Beatriz; Castillo, Edgar F; Bastos, Johanna M; Zambrano, Luz S

    2008-01-01

    The palm oil mills extraction process requires the separation of oil-water-sludge emulsions. For this purpose, the use of sedimentation and/or centrifugation techniques have been required until now. However, significant losses persist in different process flows and new methods are needed to further decrease them, such as methods based on electromagnetic waves application. In the study, emulsions obtained from two flow processes, namely press liquor stream (PL) and recovered stream of the centrifugal step (RC), were exposed to microwave radiation with different exposure times. In the case of the press liquor stream, different oil/water dilution ratios were also studied. The sedimentation speed and efficiency were studied for the irradiated samples and compared to those obtained for the same fluids with no radiation. Also, chromatographic tests were performed on the recovered oil to determine the effect on the oil quality after microwave radiation. The obtained results allow us to conclude that microwave exposure during periods below 1 minute lead to better sedimentation speed and efficiency. It was observed that microwaves facilitate the break of the charges and polarities balances in the emulsions at considerably lower temperatures than the corresponding in the conventional process, without affecting the recovered oil quality.

  7. An exactly solvable Ogston model of gel electrophoresis: X. Application to high-field separation techniques.

    PubMed

    Gauthier, Michel G; Slater, Gary W

    2003-01-01

    Recently, we generalized our lattice model of gel electrophoresis to study the net velocity of particles being pulled by a high-intensity electric field through an arbitrary distribution of immobile obstacles (Gauthier, M. G., Slater, G. W., J. Chem. Phys. 2002, 117, 6745-6756). In this article, we show how the high-field version of our model can be used to compare the velocity of particles with different electric charges and/or physical sizes. We then investigate specific two-dimensional distributions of obstacles that can be used to separate particles, e.g., in a microfluidic device. More precisely, we compare the velocity of differently charged or sized analytes in sieving, trapping and deflecting systems to model various electrophoretic separation techniques. In particular, we study the nonlinear effects present in ratchet systems and how they can be combined with time-asymmetric pulsed fields to provide new modes of separation.

  8. Enhanced protein electrophoresis technique for separating human skeletal muscle myosin heavy chain isoforms

    NASA Technical Reports Server (NTRS)

    Bamman, M. M.; Clarke, M. S.; Talmadge, R. J.; Feeback, D. L.

    1999-01-01

    Talmadge and Roy (J. Appl. Physiol. 1993, 75, 2337-2340) previously established a sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) protocol for separating all four rat skeletal muscle myosin heavy chain (MHC) isoforms (MHC I, IIa, IIx, IIb); however, when applied to human muscle, the type II MHC isoforms (Ila, IIx) are not clearly distinguished. In this brief paper we describe a modification of the SDS-PAGE protocol which yields distinct and consistent separation of all three adult human MHC isoforms (MHC I, IIa, IIx) in a minigel system. MHC specificity of each band was confirmed by Western blot using three monoclonal IgG antibodies (mAbs) immunoreactive against MHCI (mAb MHCs, Novacastra Laboratories), MHCI+IIa (mAb BF-35), and MHCIIa+IIx (mAb SC-71). Results provide a valuable SDS-PAGE minigel technique for separating MHC isoforms in human muscle without the difficult task of casting gradient gels.

  9. Biophysical separation of Staphylococcus epidermidis strains based on antibiotic resistance

    PubMed Central

    Jones, Paul V.; Huey, Shannon; Davis, Paige; McLemore, Ryan; McLaren, Alex

    2015-01-01

    Electrophoretic and dielectrophoretic approaches to separations can provide unique capabilities. In the past, capillary and microchip-based approaches to electrophoresis have demonstrated extremely high-resolution separations. More recently, dielectrophoretic systems have shown excellent results for the separation of bioparticles. Here we demonstrate resolution of a difficult pair of targets: gentamicin resistant and susceptible strains of Staphylococcus epidermidis. This separation has significant potential implications for healthcare. This establishes a foundation for biophysical separations as a direct diagnostic tool, potentially improving nearly every figure of merit for diagnostics and antibiotic stewardship. The separations are performed on a modified gradient insulator-based dielectrophoresis (g-iDEP) system and demonstrate that the presence of antibiotic resistance enzymes (or secondary effects) produces a sufficient degree of electrophysical difference to allow separation. The differentiating factor is the ratio of electrophoretic to dielectrophoretic mobilities. This factor is 4.6 ± 0.6 × 109 V m–2 for the resistant strain, versus 9.2 ± 0.4 × 109 V m–2 for the susceptible strain. Using g-iDEP separation, this difference produces clear and easily discerned differentiation of the two strains. PMID:26086047

  10. Development of a Technique for Separating Raman Scattering Signals from Background Emission with Single-Shot Measurement Potential

    NASA Technical Reports Server (NTRS)

    Hartfield, Roy J., Jr.; Dobson, Chris; Eskridge, Richard; Wehrmeyer, Joseph A.

    1997-01-01

    A novel technique for extracting Q-branch Raman signals scattered by a diatomic species from the emission spectrum resulting from the irradiation of combustion products using a broadband excimer laser has been developed. This technique is based on the polarization characteristics of vibrational Raman scattering and can be used for both single-shot Raman extraction and time-averaged data collection. The Q-branch Raman signal has a unique set of polarization characteristics which depend on the direction of the scattering while fluorescence signals are unpolarized. For the present work, a calcite crystal is used to separate the horizonal component of a collected signal from the vertical component. The two components are then sent through a UV spectrometer and imaged onto an intensified CCD camera separately. The vertical component contains both the Raman signal and the interfering fluorescence signal. The horizontal component contains the fluorescence signal and a very weak component of the Raman signal; hence, the Raman scatter can be extracted by taking the difference between the two signals. The separation of the Raman scatter from interfering fluorescence signals is critically important to the interpretation of the Raman for cases in which a broadband ultraviolet (UV) laser is used as an excitation source in a hydrogen-oxygen flame and in all hydrocarbon flames. The present work provides a demonstration of the separation of the Raman scatter from the fluorescence background in real time.

  11. Protein separation using affinity-based reversed micelles

    PubMed

    Sun; Gu; Tong; Bai; Ichikawa; Furusaki

    1999-05-01

    Reversed micellar two-phase extraction is a developing technique for protein separation. Introduction of an affinity ligand is considered to be an effective approach to increase the selectivity and capacity of reversed micelles. In this article, Cibacron Blue F3G-A (CB) as an affinity ligand was immobilized to reversed micelles composed of soybean lecithin by a two-phase reaction. The affinity partitioning of lysozyme and bovine serum albumin (BSA) to the CB-lecithin micelles was studied. Formation of mixed micelles by additionally introducing a nonionic surfactant, Tween 85, to the CB-lecithin micelles was effective to increase the solubilization of lysozyme due to the increase of W0 (water/surfactant molar ratio)/micellar size. The partitioning isotherms of lysozyme to the CB-lecithin micelles with and without Tween 85 were expressed by the Langmuir equation. The dissociation constants in the Langmuir equation decreased on addition of Tween 85, indicating the increase of the effectiveness of lysozyme binding to the immobilized CB. On addition of 20 g/L Tween 85 to 50 g/L lecithin/hexane micellar phase containing 0.1 mmol/L CB, the extraction capacity for lysozyme could be increased by 42%. Moreover, the CB-lecithin micelles with or without Tween 85 showed significant size exclusion for BSA due to its high molecular weight. Thus, lysozyme and BSA were separated from artificial solutions containing the two proteins. In addition, the affinity-based reversed micellar phase containing Tween 85 was recycled three times for lysozyme purification from crude egg-white solutions. Lysozyme purity increased by 16-18-fold, reaching 60-70% in the recycled use.

  12. Blood separation on microfluidic paper-based analytical devices.

    PubMed

    Songjaroen, Temsiri; Dungchai, Wijitar; Chailapakul, Orawon; Henry, Charles S; Laiwattanapaisal, Wanida

    2012-09-21

    A microfluidic paper-based analytical device (μPAD) for the separation of blood plasma from whole blood is described. The device can separate plasma from whole blood and quantify plasma proteins in a single step. The μPAD was fabricated using the wax dipping method, and the final device was composed of a blood separation membrane combined with patterned Whatman No.1 paper. Blood separation membranes, LF1, MF1, VF1 and VF2 were tested for blood separation on the μPAD. The LF1 membrane was found to be the most suitable for blood separations when fabricating the μPAD by wax dipping. For blood separation, the blood cells (both red and white) were trapped on blood separation membrane allowing pure plasma to flow to the detection zone by capillary force. The LF1-μPAD was shown to be functional with human whole blood of 24-55% hematocrit without dilution, and effectively separated blood cells from plasma within 2 min when blood volumes of between 15-22 μL were added to the device. Microscopy was used to confirm that the device isolated plasma with high purity with no blood cells or cell hemolysis in the detection zone. The efficiency of blood separation on the μPAD was studied by plasma protein detection using the bromocresol green (BCG) colorimetric assay. The results revealed that protein detection on the μPAD was not significantly different from the conventional method (p > 0.05, pair t-test). The colorimetric measurement reproducibility on the μPAD was 2.62% (n = 10) and 5.84% (n = 30) for within-day and between day precision, respectively. Our proposed blood separation on μPAD has the potential for reducing turnaround time, sample volume, sample preparation and detection processes for clinical diagnosis and point-of care testing.

  13. A Technique for Separating the Gravitational Torques of Bars and Spirals in Disk Galaxies

    NASA Astrophysics Data System (ADS)

    Buta, R.; Block, D. L.; Knapen, J. H.

    2003-09-01

    We describe a Fourier-based method of separating bars from spirals in near-infrared images. The method takes advantage of the fact that a bar is typically a feature with a relatively fixed position angle and uses the simple assumption that the relative Fourier amplitudes due to the bar decline with radius past a maximum in the same or a similar manner as they rose to that maximum. With such an assumption, the bar can be extrapolated into the spiral region and removed from an image, leaving just the spiral and the axisymmetric background disk light. We refer to such a bar-subtracted image as the ``spiral plus disk'' image. The axisymmetric background (Fourier index m=0 image) can then be added back to the bar image to give the ``bar plus disk'' image. The procedure allows us to estimate the maximum gravitational torque per unit mass per unit square of the circular speed for the bar and spiral forcing separately, parameters that quantitatively define the bar strength Qb and the spiral strength Qs following the recent study of Buta & Block. For the first time, we are able to measure the torques generated by spiral arms alone, and we can now define spiral torque classes, in the same manner as bar torque classes are delineated. We outline the complete procedure here using a 2.1 μm image of NGC 6951, a prototypical SAB(rs)bc spiral having an absolute blue magnitude of -21 and a maximum rotation velocity of 230 km s-1. Comparison between a rotation curve predicted from the m=0 near-infrared light distribution and an observed rotation curve suggests that NGC 6951 is maximum disk in its bar and main spiral region, implying that our assumption of a constant mass-to-light ratio in our analysis is probably reliable. We justify our assumption on how to make the bar extrapolation using an analysis of NGC 4394, a barred spiral with only weak near-infrared spiral structure, and we justify the number of needed Fourier terms using NGC 1530, one of the most strongly barred galaxies

  14. Battery separators based on polyphenylquinoxaline polymer blends. Final report

    SciTech Connect

    Angres, I.; Kowalchik, L.; Parkhurst, W.

    1981-04-01

    This document is a final report on battery separators based on polyphenylquinoxaline (PPQ) polymer blends. The report describes the preparation of the polymer blends and their extrusion into membranes, reports a series of quality assurance tests for the membranes, and reports cycle life testing of the new membranes. The test results for the PPQ blend membranes are compared with the results obtained for standard separator membranes. It is concluded that PPQ/Cellulose Acetate is a good candidate material for alkaline battery separators; however, because of cost considerations, it is not competative with similar state-of-the-art materials.

  15. Separations systems data base: a users' manual. Revision I

    SciTech Connect

    Roddy, J.W.; McDowell, W.J.

    1981-01-01

    A separations systems data base (SEPSYS), designed specifically for the retrieval of information needed in chemical separations problems (i.e., how to perform a given separation under given conditions), is described. Included are descriptions of the basic methods of searching and retrieving information from the data base, the procedure for entering records into the data base, a listing of additional references concerning the computer information process, and an example of a typical record. The initial entries are concerned primarily with liquid-liquid extraction and liquid-solid ion exchange methods for metal ions and salts; however, the data base is constructed so that almost any separation process can be accommodated. Each record is indexed with information provided under the following fields: author; title; publication source; date of publication; organization sponsoring the work; brief abstract of the work; abstract number if the work has been so referenced, and/or abstractors initials; type of separation system used (e.g., flotation); specific or generic name of the separation agent used (e.g., acetylacetone); list of substances separated (e.g., gold, copper); qualitative description of the supporting medium or matrix containing the substances before separation (e.g., nitrate); type of literature where the record was printed (e.g., book); and type of information that the article contains. Each of these fields may be searched independently of the others (or in combination), and the last six fields contain specific key words that are listed in the report. Definitions are provided for the 36 information terms.

  16. A Convex Geometry-Based Blind Source Separation Method for Separating Nonnegative Sources.

    PubMed

    Yang, Zuyuan; Xiang, Yong; Rong, Yue; Xie, Kan

    2015-08-01

    This paper presents a convex geometry (CG)-based method for blind separation of nonnegative sources. First, the unaccessible source matrix is normalized to be column-sum-to-one by mapping the available observation matrix. Then, its zero-samples are found by searching the facets of the convex hull spanned by the mapped observations. Considering these zero-samples, a quadratic cost function with respect to each row of the unmixing matrix, together with a linear constraint in relation to the involved variables, is proposed. Upon which, an algorithm is presented to estimate the unmixing matrix by solving a classical convex optimization problem. Unlike the traditional blind source separation (BSS) methods, the CG-based method does not require the independence assumption, nor the uncorrelation assumption. Compared with the BSS methods that are specifically designed to distinguish between nonnegative sources, the proposed method requires a weaker sparsity condition. Provided simulation results illustrate the performance of our method.

  17. Neuroproteomic profiling of human brain tissue using multidimensional separation techniques and selective enrichment of membrane proteins.

    PubMed

    Musunuri, Sravani; Shevchenko, Ganna; Bergquist, Jonas

    2012-12-01

    Hydrophobic membrane proteins (MPs) occupy a unique niche in the brain proteome research due to their important physiological roles. Therefore, the extraction, separation, and identification of MPs are of great interest in proteomic analysis. We applied various proteomic techniques to enrich, separate, and analyze the human brain proteome, including membrane proteome. Temperature-induced phase fractionation with the nonionic surfactant Triton X-114 was used to simultaneously extract, separate, and concentrate low abundant hydrophobic and high abundant hydrophilic proteins from human brain tissue. The extracted and delipidated proteins were analyzed by two-dimensional gel electrophoresis (2DE). Approximately 600 spots were detected in the gels. In-solution digestion was performed on 3 kDa spin filters. Tryptic peptides were separated using RP nano-LC and analyzed using two different high performance mass spectrometers, linear ion trap-Fourier transform and a linear ion trap-Orbitrap to reveal the low abundant MPs. In total, 837 and 780 unique proteins were identified by using linear ion trap-Fourier transform and linear ion trap-Orbitrap mass spectrometers, respectively. More than 29% of the identified proteins were classified as MPs with significant biological functions such as ion channels and transporters. Our study establishes a simple and rapid shotgun approach for the characterization of the brain proteome, and allows comprehensive analysis of brain membrane proteomes.

  18. Capillarity-driven blood plasma separation on paper-based devices.

    PubMed

    Kar, Shantimoy; Maiti, Tapas Kumar; Chakraborty, Suman

    2015-10-07

    We demonstrate capillarity-driven plasma separation from whole blood on simple paper-based H-channels. This methodology, unlike other reported techniques, does not necessitate elaborate and complex instrumentation, and the usage of expensive consumables. We believe that this technique will be ideally suited to be implemented in rapid and portable blood diagnostic devices designed to be operative at locations with limited resources.

  19. Drop Size Distribution - Based Separation of Stratiform and Convective Rain

    NASA Technical Reports Server (NTRS)

    Thurai, Merhala; Gatlin, Patrick; Williams, Christopher

    2014-01-01

    For applications in hydrology and meteorology, it is often desirable to separate regions of stratiform and convective rain from meteorological radar observations, both from ground-based polarimetric radars and from space-based dual frequency radars. In a previous study by Bringi et al. (2009), dual frequency profiler and dual polarization radar (C-POL) observations in Darwin, Australia, had shown that stratiform and convective rain could be separated in the log10(Nw) versus Do domain, where Do is the mean volume diameter and Nw is the scaling parameter which is proportional to the ratio of water content to the mass weighted mean diameter. Note, Nw and Do are two of the main drop size distribution (DSD) parameters. In a later study, Thurai et al (2010) confirmed that both the dual-frequency profiler based stratiform-convective rain separation and the C-POL radar based separation were consistent with each other. In this paper, we test this separation method using DSD measurements from a ground based 2D video disdrometer (2DVD), along with simultaneous observations from a collocated, vertically-pointing, X-band profiling radar (XPR). The measurements were made in Huntsville, Alabama. One-minute DSDs from 2DVD are used as input to an appropriate gamma fitting procedure to determine Nw and Do. The fitted parameters - after averaging over 3-minutes - are plotted against each other and compared with a predefined separation line. An index is used to determine how far the points lie from the separation line (as described in Thurai et al. 2010). Negative index values indicate stratiform rain and positive index indicate convective rain, and, moreover, points which lie somewhat close to the separation line are considered 'mixed' or 'transition' type precipitation. The XPR observations are used to evaluate/test the 2DVD data-based classification. A 'bright-band' detection algorithm was used to classify each vertical reflectivity profile as either stratiform or convective

  20. Recent trends in analytical methods and separation techniques for drugs of abuse in hair.

    PubMed

    Baciu, T; Borrull, F; Aguilar, C; Calull, M

    2015-01-26

    Hair analysis of drugs of abuse has been a subject of growing interest from a clinical, social and forensic perspective for years because of the broad time detection window after intake in comparison to urine and blood analysis. Over the last few years, hair analysis has gained increasing attention and recognition for the retrospective investigation of drug abuse in a wide variety of contexts, shown by the large number of applications developed. This review aims to provide an overview of the state of the art and the latest trends used in the literature from 2005 to the present in the analysis of drugs of abuse in hair, with a special focus on separation analytical techniques and their hyphenation with mass spectrometry detection. The most recently introduced sample preparation techniques are also addressed in this paper. The main strengths and weaknesses of all of these approaches are critically discussed by means of relevant applications.

  1. Spectral separation of optical spin based on antisymmetric Fano resonances

    PubMed Central

    Piao, Xianji; Yu, Sunkyu; Hong, Jiho; Park, Namkyoo

    2015-01-01

    We propose a route to the spectral separation of optical spin angular momentum based on spin-dependent Fano resonances with antisymmetric spectral profiles. By developing a spin-form coupled mode theory for chiral materials, the origin of antisymmetric Fano spectra is clarified in terms of the opposite temporal phase shift for each spin, which is the result of counter-rotating spin eigenvectors. An analytical expression of a spin-density Fano parameter is derived to enable quantitative analysis of the Fano-induced spin separation in the spectral domain. As an application, we demonstrate optical spin switching utilizing the extreme spectral sensitivity of the spin-density reversal. Our result paves a path toward the conservative spectral separation of spins without any need of the magneto-optical effect or circular dichroism, achieving excellent purity in spin density superior to conventional approaches based on circular dichroism. PMID:26561372

  2. Comparison Between Digital and Analog Pulse Shape Discrimination Techniques for Neutron and Gamma Ray Separation

    SciTech Connect

    Rahmat Aryaeinejad

    2005-10-01

    Recent advancements in digital signal processing (DSP) using fast processors and a computer allows one to envision using it in pulse shape discrimination. In this study, we have investigated the feasibility of using a DSP to distinguish between neutrons and gamma rays by the shape of their pulses in a liquid scintillator detector (BC501). For neutron/gamma discrimination, the advantage of using a DSP over the analog method is that in an analog system, two separate charge-sensitive ADCs are required. One ADC is used to integrate the beginning of the pulse rise time while the second ADC is for integrating the tail part. In DSP techniques the incoming pulses coming directly from the detector are immediately digitized and can be decomposed into individual pulses waveforms. This eliminates the need for separate ADCs as one can easily get the integration of two parts of the pulse from the digital waveforms. This work describes the performance of these DSP techniques and compares the results with the analog method.

  3. Improved Separability Criteria Based on Bloch Representation of Density Matrices

    PubMed Central

    Shen, Shu-Qian; Yu, Juan; Li, Ming; Fei, Shao-Ming

    2016-01-01

    The correlation matrices or tensors in the Bloch representation of density matrices are encoded with entanglement properties. In this paper, based on the Bloch representation of density matrices, we give some new separability criteria for bipartite and multipartite quantum states. Theoretical analysis and some examples show that the proposed criteria can be more efficient than the previous related criteria. PMID:27350031

  4. Techniques for Enhancing Web-Based Education.

    ERIC Educational Resources Information Center

    Barbieri, Kathy; Mehringer, Susan

    The Virtual Workshop is a World Wide Web-based set of modules on high performance computing developed at the Cornell Theory Center (CTC) (New York). This approach reaches a large audience, leverages staff effort, and poses challenges for developing interesting presentation techniques. This paper describes the following techniques with their…

  5. Base-Catalyzed Depolymerization of Lignin: Separation of Monomers

    SciTech Connect

    Vigneault, A.; Johnson, D. K.; Chornet, E.

    2007-12-01

    In our quest for fractionating lignocellulosic biomass and valorizing specific constitutive fractions, we have developed a strategy for the separation of 12 added value monomers generated during the hydrolytic based-catalyzed depolymerization of a Steam Exploded Aspen Lignin. The separation strategy combines liquid-liquid-extraction (LLE), followed by vacuum distillation, liquid chromatography (LC) and crystallization. LLE, vacuum distillation and flash LC were tested experimentally. Batch vacuum distillation produced up to 4 fractions. Process simulation confirmed that a series of 4 vacuum distillation columns could produce 5 distinct monomer streams, 3 of which require further chromatography and crystallization for purification.

  6. Auto white balance method using a pigmentation separation technique for human skin color

    NASA Astrophysics Data System (ADS)

    Tanaka, Satomi; Kakinuma, Akihiro; Kamijo, Naohiro; Takahashi, Hiroshi; Tsumura, Norimichi

    2017-02-01

    The human visual system maintains the perception of colors of an object across various light sources. Similarly, current digital cameras feature an auto white balance function, which estimates the illuminant color and corrects the color of a photograph as if the photograph was taken under a certain light source. The main subject in a photograph is often a person's face, which could be used to estimate the illuminant color. However, such estimation is adversely affected by differences in facial colors among individuals. The present paper proposes an auto white balance algorithm based on a pigmentation separation method that separates the human skin color image into the components of melanin, hemoglobin and shading. Pigment densities have a uniform property within the same race that can be calculated from the components of melanin and hemoglobin in the face. We, thus, propose a method that uses the subject's facial color in an image and is unaffected by individual differences in facial color among Japanese people.

  7. Auto white balance method using a pigmentation separation technique for human skin color

    NASA Astrophysics Data System (ADS)

    Tanaka, Satomi; Kakinuma, Akihiro; Kamijo, Naohiro; Takahashi, Hiroshi; Tsumura, Norimichi

    2016-11-01

    The human visual system maintains the perception of colors of an object across various light sources. Similarly, current digital cameras feature an auto white balance function, which estimates the illuminant color and corrects the color of a photograph as if the photograph was taken under a certain light source. The main subject in a photograph is often a person's face, which could be used to estimate the illuminant color. However, such estimation is adversely affected by differences in facial colors among individuals. The present paper proposes an auto white balance algorithm based on a pigmentation separation method that separates the human skin color image into the components of melanin, hemoglobin and shading. Pigment densities have a uniform property within the same race that can be calculated from the components of melanin and hemoglobin in the face. We, thus, propose a method that uses the subject's facial color in an image and is unaffected by individual differences in facial color among Japanese people.

  8. Sample preparation and separation techniques for bioanalysis of morphine and related substances.

    PubMed

    Hansen, Steen Honoré

    2009-03-01

    In present time the use or misuse of morphine and its derivatives are monitored by assaying the presence of the drug and its metabolites in biofluids. In the present review, focus is placed on the sample preparation and on the separation techniques used in the current best practices of bioanalysis of morphine and its major metabolites. However, as methods for testing the misuse of heroin, a morphine derivative, often involve bioanalytical methods that cover a number of other illicit drug substances, such methods are also included in the review. Furthermore, the review also includes bioanalysis in a broader perspective as analysis of plant materials, cell cultures and environmental samples. The review is not intended to cover all publications that include bioanalysis of morphine but is more to be considered a view into the current best practices of bioanalysis of morphine, its metabolites and other related substances.

  9. Graphene reflux: improving the yield of liquid-exfoliated nanosheets through repeated separation techniques

    NASA Astrophysics Data System (ADS)

    Rountree, Kyler S.; Shah, Smit A.; Sweeney, Charles B.; Irin, Fahmida; Green, Micah J.

    2016-12-01

    Scalable production of graphene through liquid-phase exfoliation has been plagued by low yields. Although several recent studies have attempted to improve graphene exfoliation technology, the problem of separating colloidal nanosheets from unexfoliated parent material has received far less attention. Here we demonstrate a scalable method for improving nanosheet yield through a facile washing process. By probing the sedimentation of liquid-phase exfoliated slurries of graphene nanosheets and parent material, we found that a portion of exfoliated graphene is entrapped in the sediment, but can be recovered by repeatedly washing the slurry of nanosheet and parent material with additional solvent. We found this process to significantly increase the overall yield of graphene (graphene/parent material) and recover a roughly constant proportion of graphene with each wash. The cumulative amount of graphene recovered is only a function of total solvent volume. Moreover, we found this technique to be applicable to other types of nanosheets such as boron nitride nanosheets.

  10. A hydrophobic ionic liquid compartmentalized sampling/labeling and its separation techniques in polydimethylsiloxane microchip capillary electrophoresis.

    PubMed

    Quan, Hong Hua; Li, Ming; Huang, Yan; Hahn, Jong Hoon

    2017-01-01

    This paper demonstrates a novel compartmentalized sampling/labeling method and its separation techniques using a hydrophobic ionic liquid (IL)-1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imidate (BmimNTf2 )-as the immiscible phase, which is capable of minimizing signal losses during microchip capillary electrophoresis (MCE). The MCE device consists of a silica tube connected to a straight polydimethylsiloxane (PDMS) separation channel. Poly(diallyldimethylammonium chloride) (PDDAC) was coated on the inner surface of channel to ease the introduction of IL plugs and enhance the IL wetting on the PDMS surface for sample releasing. Electroosmotic flow (EOF)-based sample compartmentalization was carried out through a sequenced injection into sampling tubes with the following order: leading IL plug/sample segment/terminal IL plug. The movement of the sample segment was easily controlled by applying an electrical voltage across both ends of the chip without a sample volume change. This approach effectively prevented analyte diffusion before injection into MCE channels. When the sample segment was manipulated to the PDDAC-modified PDMS channel, the sample plug then was released from isolation under EOF while IL plugs adsorbed onto channel surfaces owing to strong adhesion. A mixture of flavin adenine nucleotides (FAD) and flavin mononucleotides (FMN) was successfully separated on a 2.5 cm long separation channel, for which the theoretical numbers of plates were 15 000 and 17 000, respectively. The obtained peak intensity was increased 6.3-fold over the corresponding value from conventional electrokinetic injection with the same sampling time. Furthermore, based on the compartmented sample segment serving as an interim reactor, an on-chip fluorescence labeling is demonstrated.

  11. Application of capillary fluid management techniques to the design of a phase separating microgravity bioreactor

    NASA Technical Reports Server (NTRS)

    Finger, Barry W.; Neville, Gale E., Jr.; Sager, John C.

    1993-01-01

    Manned space missions require the development of compact, efficient, and reliable life support systems. A number of aqueous biological conversion processes are associated with bioregenerative life support systems. Vessels, or bioreactors, capable of supporting these processes in microgravity must be developed. An annular flow bioreactor has been conceived. It has the potential to incorporate containment, phase separation, gas exchange, and illumination into a single vessel. The bioreactor utilizes capillary fluid management techniques and is configured as a cylindrical tube in which a two-phase liquid-gas flow is maintained. Vanes placed around the inner perimeter enhance capillary forces and cause the liquid phase to attach and flow along the interior surface of the tube. No physical barrier is required to complete phase separation. It is shown analytically that liquid film thickness is limited only by vane geometry and that an annular flow bioreactor capable of managing 284 liters would occupy 0.7 cubic m, less than half the volume of a Spacelab experiment rack.

  12. Carbonylation as a separation technique for removal of non-radioactive species for tank waste

    SciTech Connect

    Visnapuu, A.; Hollenberg, G.W.; Creed, R.F. Jr.

    1994-05-01

    Much of the waste generated from five decades of weapons production in the US Department of Energy complex contains highly radioactive constituents. With the high cost of permanent disposal space, it is necessary to separate as many of the nonradioactive species from the radioactive as possible. This paper discusses the transfer of carbonyl processing technology from mineral beneficiation and powder metallurgy operations to the separation of Fe and Ni from radioactively contaminated waste streams. Samples of simulated composite Hanford Tank Waste residue were first processed with a calcine/dissolution technique which resulted in a residue powder consisting of 31.9 pct Fe and 3.3 pct Ni. Because of the specification for waste glass compositions, these two constituents become important in determining the number of waste glass logs produced. Pyrometallurgical reduction of the residue powders, followed by subsequent carbonylation, extracted up to 92.0 pct of the Fe and 95.7 pct of the Ni. The resultant product contained as little as 4.9 pct Fe and 0.3 pct Ni. At this level, Fe would no longer be a limiting constituent in the waste glass.

  13. Metal separation from mixed types of batteries using selective precipitation and liquid-liquid extraction techniques.

    PubMed

    Provazi, Kellie; Campos, Beatriz Amaral; Espinosa, Denise Crocce Romano; Tenório, Jorge Alberto Soares

    2011-01-01

    The purpose of this paper is to study metal separation from a sample composed of a mixture of the main types of spent household batteries, using a hydrometallurgical route, comparing selective precipitation and liquid-liquid extraction separation techniques. The preparation of the solution consisted of: grinding the waste of mixed batteries, reduction and volatile metals elimination using electric furnace and acid leaching. From this solution two different routes were studied: selective precipitation with sodium hydroxide and liquid-liquid extraction using Cyanex 272 [bis(2,4,4-trimethylpentyl) phosphoric acid] as extracting agent. The best results were obtained from liquid-liquid extraction in which Zn had a 99% extraction rate at pH 2.5. More than 95% Fe was extracted at pH 7.0, the same pH at which more than 90% Ce was extracted. About 88% Mn, Cr and Co was extracted at this pH. At pH 3.0, more than 85% Ni was extracted, and at pH 3.5 more than 80% of Cd and La was extracted.

  14. Subspace-Based Bayesian Blind Source Separation for Hyperspectral Imagery

    DTIC Science & Technology

    2009-12-01

    Subspace-based Bayesian blind source separation for hyperspectral imagery Nicolas Dobigeon∗, Saı̈d Moussaoui†, Martial Coulon∗, Jean-Yves Tourneret...In this paper, a fully Bayesian algorithm for endmember extraction and abundance estimation for hyperspectral imagery is in- troduced. Following the...linear mixing model, each pixel spectrum of the hyperspectral image is decomposed as a linear combination of pure endmember spectra. The estimation of

  15. Preliminary investigation of a technique to separate fission noble metals from fission product mixtures

    SciTech Connect

    Mellinger, G.B.; Jensen, G.A.

    1982-08-01

    A variation of the gold-ore fire assay technique was examined as a method for recovering Pd, Rh and Ru from fission products. The mixture of fission product oxides is combined with glass-forming chemicals, a metal oxide such as PbO (scavenging agent), and a reducing agent such as charcoal. When this mixture is melted, a metal button is formed which extracts the noble metals. The remainder cools to form a glass for nuclear waste storage. Recovery depended only on reduction of the scavenger oxide to metal. When such reduction was achieved, no difference in noble metal recovery efficiency was found among the scavengers studied (PbO, SnO, CuO, Bi/sub 2/O/sub 3/, Sb/sub 2/O/sub 3/). Not all reducing agents studied, however, were able to reduce all scavenger oxides to metal. Only graphite would reduce SnO and CuO and allow noble metal recovery. The scavenger oxides Sb/sub 2/O/sub 3/, Bi/sub 2/O/sub 3/, and PbO, however, were reduced by all of the reducing agents tested. Similar noble metal recovery was found with each. Lead oxide was found to be the most promising of the potential scavengers. It was reduced by all of the reducing agents tested, and its higher density may facilitate the separation. Use of lead oxide also appeared to have no deterimental effect on the glass quality. Charcoal was identified as the preferred reducing agent. As long as a separable metal phase was formed in the melt, noble metal recovery was not dependent on the amount of reducing agent and scavenger oxide. High glass viscosities inhibited separation of the molten scavenger, while low viscosities allowed volatile loss of RuO/sub 4/. A viscosity of approx. 20 poise at the processing temperature offered a good compromise between scavenger separation and Ru recovery. Glasses in which PbO was used as the scavenging agent were homogeneous in appearance. Resistance to leaching was close to that of certain waste glasses reported in the literature. 12 figures. 7 tables.

  16. High throughput SNP detection system based on magnetic nanoparticles separation.

    PubMed

    Liu, Bin; Jia, Yingying; Ma, Man; Li, Zhiyang; Liu, Hongna; Li, Song; Deng, Yan; Zhang, Liming; Lu, Zhuoxuan; Wang, Wei; He, Nongyue

    2013-02-01

    Single-nucleotide polymorphism (SNP) was one-base variations in DNA sequence that can often be helpful to find genes associations for hereditary disease, communicable disease and so on. We developed a high throughput SNP detection system based on magnetic nanoparticles (MNPs) separation and dual-color hybridization or single base extension. This system includes a magnetic separation unit for sample separation, three high precision robot arms for pipetting and microtiter plate transferring respectively, an accurate temperature control unit for PCR and DNA hybridization and a high accurate and sensitive optical signal detection unit for fluorescence detection. The cyclooxygenase-2 gene promoter region--65G > C polymorphism locus SNP genotyping experiment for 48 samples from the northern Jiangsu area has been done to verify that if this system can simplify manual operation of the researchers, save time and improve efficiency in SNP genotyping experiments. It can realize sample preparation, target sequence amplification, signal detection and data analysis automatically and can be used in clinical molecule diagnosis and high throughput fluorescence immunological detection and so on.

  17. Fabrication and testing of novel blood separation devices based on microchannel bend structures

    NASA Astrophysics Data System (ADS)

    Blattert, C.; Jurischka, R.; Schoth, A.; Kerth, P.; Menz, W.

    2005-02-01

    Most clinical chemistry tests are performed on cell-free serum or plasma. Therefore micro assay devices for blood tests require integrated on-chip microfluidics for separation of plasma or serum from blood. Polymers are ideally suited for these applications due to their material properties and their applicability for high volume production. These requirements are achieved by a new on-chip blood separation technique based on microchannel bend structures and a rapid processing technology for micro assay devices using injection molding or hot embossing. Different prototype polymer chips with channel dimensions down to 20 μm and aspect ratios of 4 have been fabricated by injection molding and hot embossing. The inserts for the molding tools were fabricated by an UV-LIGA technology. The separation efficiency of these chips has been tested with human blood samples. The results show different separation efficiencies up to 100 % for blood cells and plasma depending on microchannel geometry as well as cell concentration. As compared to present microfluidic devices for the separation of blood cells like filters, membranes or filtration by diffusion the microchannel bend is an integrated on-chip blood separation method. It combines the advantages of rapid separation times and a simple geometry that leads to cost-effective high volume production using injection molding.

  18. Chromatographic Studies of Protein-Based Chiral Separations.

    PubMed

    Bi, Cong; Zheng, Xiwei; Azaria, Shiden; Beeram, Sandya; Li, Zhao; Hage, David S

    2016-09-01

    The development of separation methods for the analysis and resolution of chiral drugs and solutes has been an area of ongoing interest in pharmaceutical research. The use of proteins as chiral binding agents in high-performance liquid chromatography (HPLC) has been an approach that has received particular attention in such work. This report provides an overview of proteins that have been used as binding agents to create chiral stationary phases (CSPs) and in the use of chromatographic methods to study these materials and protein-based chiral separations. The supports and methods that have been employed to prepare protein-based CSPs will also be discussed and compared. Specific types of CSPs that are considered include those that employ serum transport proteins (e.g., human serum albumin, bovine serum albumin, and alpha1-acid glycoprotein), enzymes (e.g., penicillin G acylase, cellobiohydrolases, and α-chymotrypsin) or other types of proteins (e.g., ovomucoid, antibodies, and avidin or streptavidin). The properties and applications for each type of protein and CSP will also be discussed in terms of their use in chromatography and chiral separations.

  19. Chromatographic Studies of Protein-Based Chiral Separations

    PubMed Central

    Bi, Cong; Zheng, Xiwei; Azaria, Shiden; Beeram, Sandya; Li, Zhao; Hage, David S.

    2016-01-01

    The development of separation methods for the analysis and resolution of chiral drugs and solutes has been an area of ongoing interest in pharmaceutical research. The use of proteins as chiral binding agents in high-performance liquid chromatography (HPLC) has been an approach that has received particular attention in such work. This report provides an overview of proteins that have been used as binding agents to create chiral stationary phases (CSPs) and in the use of chromatographic methods to study these materials and protein-based chiral separations. The supports and methods that have been employed to prepare protein-based CSPs will also be discussed and compared. Specific types of CSPs that are considered include those that employ serum transport proteins (e.g., human serum albumin, bovine serum albumin, and alpha1-acid glycoprotein), enzymes (e.g., penicillin G acylase, cellobiohydrolases, and α-chymotrypsin) or other types of proteins (e.g., ovomucoid, antibodies, and avidin or streptavidin). The properties and applications for each type of protein and CSP will also be discussed in terms of their use in chromatography and chiral separations. PMID:28344977

  20. Separation of peptides on superficially porous particle based macrocyclic glycopeptide liquid chromatography stationary phases: consideration of fast separations.

    PubMed

    Wimalasinghe, Rasangi M; Breitbach, Zachary S; Lee, Jauh T; Armstrong, Daniel W

    2017-03-01

    Macrocyclic glycopeptide based liquid chromatography stationary phases are known for their highly selective peptide separations. Fast and ultrafast (t R < 1 min) high-efficiency separations were achieved with superficially porous particle (SPP)-based stationary phases. Separations of pharmaceutically important classes of peptides such as enkephalins and bradykinins have been achieved in less than 5 min in isocratic elution modes. Selectivity for peptides structurally similar to one another was increased with use of teicoplanin-based stationary phases compared with commercial C18 stationary phases. Ultrafast isocratic separations of structurally related peptides were achieved with teicoplanin- and vancomycin-based short SPP columns. Acidic mobile phases produced better separations. Ammonium formate was the optimal mobile phase buffer additive. Use of an appropriate combination of a macrocyclic glycopeptide stationary phase and a mobile phase permits faster and more electrospray ionization mass spectrometry compatible isocratic separations than previous gradient approaches. The tryptic peptide separation characteristics of the teicoplanin stationary phase are demonstrated. Additionally, compared with commercial C18 stationary phases, teicoplanin showed tryptic peptide separations with different selectivities. Graphical Abstract Ultrafast separation of enkephalin peptide epimers.

  1. High-Throughput Genetic Analysis and Combinatorial Chiral Separations Based on Capillary Electrophoresis

    SciTech Connect

    Zhong, Wenwan

    2003-01-01

    Capillary electrophoresis (CE) offers many advantages over conventional analytical methods, such as speed, simplicity, high resolution, low cost, and small sample consumption, especially for the separation of enantiomers. However, chiral method developments still can be time consuming and tedious. They designed a comprehensive enantioseparation protocol employing neutral and sulfated cyclodextrins as chiral selectors for common basic, neutral, and acidic compounds with a 96-capillary array system. By using only four judiciously chosen separation buffers, successful enantioseparations were achieved for 49 out of 54 test compounds spanning a large variety of pKs and structures. Therefore, unknown compounds can be screened in this manner to identify optimal enantioselective conditions in just one rn. In addition to superior separation efficiency for small molecules, CE is also the most powerful technique for DNA separations. Using the same multiplexed capillary system with UV absorption detection, the sequence of a short DNA template can be acquired without any dye-labels. Two internal standards were utilized to adjust the migration time variations among capillaries, so that the four electropherograms for the A, T, C, G Sanger reactions can be aligned and base calling can be completed with a high level of confidence. the CE separation of DNA can be applied to study differential gene expression as well. Combined with pattern recognition techniques, small variations among electropherograms obtained by the separation of cDNA fragments produced from the total RNA samples of different human tissues can be revealed. These variations reflect the differences in total RNA expression among tissues. Thus, this Ce-based approach can serve as an alternative to the DNA array techniques in gene expression analysis.

  2. Gravity packaging final waste recovery based on gravity separation and chemical imaging control.

    PubMed

    Bonifazi, Giuseppe; Serranti, Silvia; Potenza, Fabio; Luciani, Valentina; Di Maio, Francesco

    2017-02-01

    Plastic polymers are characterized by a high calorific value. Post-consumer plastic waste can be thus considered, in many cases, as a typical secondary solid fuels according to the European Commission directive on End of Waste (EoW). In Europe the practice of incineration is considered one of the solutions for waste disposal waste, for energy recovery and, as a consequence, for the reduction of waste sent to landfill. A full characterization of these products represents the first step to profitably and correctly utilize them. Several techniques have been investigated in this paper in order to separate and characterize post-consumer plastic packaging waste fulfilling the previous goals, that is: gravity separation (i.e. Reflux Classifier), FT-IR spectroscopy, NIR HyperSpectralImaging (HSI) based techniques and calorimetric test. The study demonstrated as the proposed separation technique and the HyperSpectral NIR Imaging approach allow to separate and recognize the different polymers (i.e. PolyVinyl Chloride (PVC), PolyStyrene (PS), PolyEthylene (PE), PoliEtilene Tereftalato (PET), PolyPropylene (PP)) in order to maximize the removal of the PVC fraction from plastic waste and to perform the full quality control of the resulting products, can be profitably utilized to set up analytical/control strategies finalized to obtain a low content of PVC in the final Solid Recovered Fuel (SRF), thus enhancing SRF quality, increasing its value and reducing the "final waste".

  3. Laser vaporization/ionization interface for coupling microscale separation techniques with mass spectrometry

    DOEpatents

    Yeung, Edward S.; Chang, Yu-chen

    1999-06-29

    The present invention provides a laser-induced vaporization and ionization interface for directly coupling microscale separation processes to a mass spectrometer. Vaporization and ionization of the separated analytes are facilitated by the addition of a light-absorbing component to the separation buffer or solvent.

  4. Laser vaporization/ionization interface for coupling microscale separation techniques with mass spectrometry

    DOEpatents

    Yeung, E.S.; Chang, Y.C.

    1999-06-29

    The present invention provides a laser-induced vaporization and ionization interface for directly coupling microscale separation processes to a mass spectrometer. Vaporization and ionization of the separated analytes are facilitated by the addition of a light-absorbing component to the separation buffer or solvent. 8 figs.

  5. Multilocus amplification of genomic DNA from single cysts of Giardia duodenalis separated using micromanipulation technique.

    PubMed

    Aguiar, Juliana Martins; Silva, Sheila Oliveira da; Santos, Valdir Antônio Dos; Rossa, Giselle Ayres Razera; Taniwaki, Sueli Akemi; Gregori, Fabio; Keid, Lara Borges; Soares, Rodrigo Martins

    2015-10-01

    Giardia duodenalis is divided into at least eight groups, named assemblages A to H. Assemblages A and B are the only ones able to infect humans and other mammals. The species status for these assemblies is a moot point, but has not gained general acceptance because sexual activity in Giardia is not completely understood. Heterozygosity in G. duodenalis can be detected through simultaneous identification of multiple loci in single cysts or trophozoites. In this paper, we describe a technique that enables simultaneous detection of fragments from four genes from single cysts of G. duodenalis recovered from stool samples. Each cyst from a fecal sample of human origin was separated, the DNA was extracted and amplified by means of multiplex PCR directed to four genes and the multiplex PCR product was further re-amplified using four single PCR (one for each gene). The following loci were detected: beta giardin (bg), GLORF-C4 (orfC4), triose phosphate isomerase (tpi) and glutamate dehydrogenase (gdh). This procedure should make it possible to investigate multiple genes from a single cyst of G. duodenalis assemblage A or B.

  6. Electrophoretic separation techniques and their hyphenation to mass spectrometry in biological inorganic chemistry.

    PubMed

    Holtkamp, Hannah; Grabmann, Gerlinde; Hartinger, Christian G

    2016-04-01

    Electrophoretic methods have been widely applied in research on the roles of metal complexes in biological systems. In particular, CE, often hyphenated to a sensitive MS detector, has provided valuable information on the modes of action of metal-based pharmaceuticals, and more recently new methods have been added to the electrophoretic toolbox. The range of applications continues to expand as a result of enhanced CE-to-MS interfacing, with sensitivity often at picomolar level, and evolved separation modes allowing for innovative sample analysis. This article is a followup to previous reviews about CE methods in metallodrug research (Electrophoresis, 2003, 24, 2023-2037; Electrophoresis, 2007, 28, 3436-3446; Electrophoresis, 2012, 33, 622-634), also providing a comprehensive overview of metal species studied by electrophoretic methods hyphenated to MS. It highlights the latest CE developments, takes a sneak peek into gel electrophoresis, traces biomolecule labeling, and focuses on the importance of early-stage drug development.

  7. Dehumidification via membrane separation for space-based applications

    NASA Technical Reports Server (NTRS)

    Gienger, Jane Kucera; Ray, Roderick J.; Chullen, Cinda

    1988-01-01

    The paper describes the development of a membrane-based dehumidification process for space-based applications, such as spacecraft cabins and EVA space suits. Results presented are from: (1) screening tests conducted to determine the efficacy of various membranes to separate water vapor from air, and (2) parametric and long-term tests of membranes operated at conditions that simulate the range of environmental conditions (e.g., temperature and relative humidity) expected in the planned Space Station. Also included in this paper is a discussion of preliminary designs of membrane-based dehumidification processes for the Space Station and EVA space suits. These designs result in compact and energy-efficient systems that offer significant advantages over conventional dehumidification processes.

  8. Nitrogen Trifluoride-Based Fluoride- Volatility Separations Process: Initial Studies

    SciTech Connect

    McNamara, Bruce K.; Scheele, Randall D.; Casella, Andrew M.; Kozelisky, Anne E.

    2011-09-28

    This document describes the results of our investigations on the potential use of nitrogen trifluoride as the fluorinating and oxidizing agent in fluoride volatility-based used nuclear fuel reprocessing. The conceptual process uses differences in reaction temperatures between nitrogen trifluoride and fuel constituents that produce volatile fluorides to achieve separations and recover valuable constituents. We provide results from our thermodynamic evaluations, thermo-analytical experiments, kinetic models, and provide a preliminary process flowsheet. The evaluations found that nitrogen trifluoride can effectively produce volatile fluorides at different temperatures dependent on the fuel constituent.

  9. An Improved Method for Detectingand Separating Cloud from Drizzle Radar Signatures Using a Time Domain Parametric Technique

    NASA Astrophysics Data System (ADS)

    Nguyen, C.; Chandra, C. V.

    2014-12-01

    The separation of radar signatures depicting cloud and drizzle within a pulse radar volume is a fundamental problem whose solution is required to decouple the microphysical and dynamical processes introduced by turbulence. Such a solution would lead to the development of new meteorological products.In this presentation, a method to detect, separate and estimate multiple radar echoes from cloud and drizzle obtained from vertically pointing cloud Doppler spectra is described. In the case when only clouds are present, the Doppler spectrum is symmetrical and is well approximated by a Gaussian. To extract cloud echoes, a parametric maximum likelihood estimator in the time domain is employed using the recorded radar Doppler spectra data. To detect skewness in the radar spectrum, goodness of fit parameters are defined. It is shown that these new detection parameters exhibit a low level sensitivity to poor signal-to-noise ratios and large signal spectrum widths. The proposed method can consequently be applied to signals with shorter integration time; this significantly reduces the impact of small-scale dynamics present in the Doppler spectrum. Additionally, signals near the cloud top and cloud base are used as constraints to optimize the detection and estimation algorithm's performance.The applications of the technique include inference of the vertical air motion and the particle size distribution of the drizzle. The method will be tested on datasets that have been collected by the ARM cloud radars.

  10. Separation of Fission Products Based on Ionic Liquids: Anion Effect

    SciTech Connect

    Luo, Huimin; Dai, Sheng; Bonnesen, Peter V.

    2004-03-28

    The applications of ionic liquids (ILs) as new separation media have been actively investigated recently. The most commonly studied class of ILs for such applications is based on dialkyl imidazolium cations. In comparison with conventional molecular solvents, ILs exhibit enhanced distribution coefficients for a number of complexing neutral ligands in extraction of metal ions from aqueous solutions. The effect of the alkyl chain length of imidazolium cations on the distribution coefficients of solvent extraction using crown ethers was the subject of a number of the previous investigations. The distribution coefficients have been found to decrease with the alkyl chain length of the IL cations. This observation implies that the extraction process also involves the exchange of the IL cations with metal ions. The longer the alkyl chain lengths of the IL cations are, the more hydrophobic the IL cations are and the more difficult to be transported into aqueous phases via ion exchange. Accordingly, the ion-exchange process is another unique property of IL-based extractions involving charged species. Here, we report the investigation about the effect of the variation of IL anions on the solvent extraction of metal ions using crown ethers as extractants. The elucidation of different solvation effects involved in ionic liquids could lead to optimized separation media for these novel solvents.

  11. Novel nanostructured biodegradable polymer matrices fabricated by phase separation techniques for tissue regeneration.

    PubMed

    Hsu, S-H; Huang, S; Wang, Y-C; Kuo, Y-C

    2013-06-01

    Biomimetic nanostructures have a wide range of applications. In particular, biodegradable polymer nanostructures that mimic the subtleties of extracellular matrix may provide favorable cell interactions. In this study, a co-solvent system was developed to configure a thermodynamically metastable biodegradable polymer solution, from which novel nanostructured matrices subsequently formed via wet phase separation (quaternary) or a combination with thermally induced phase separation. Three-dimensional (3D) nanostructured porous matrices were further fabricated by combination with particle-leaching (100-300μm glucose). The new co-solvent system may generate matrices with reproducible nanostructures from a variety of biodegradable polymers such as poly(d,l-lactide) (PLA), poly(ε-caprolactone) (PCL) and PCL-based polyurethane. In vitro cell culture experiments were performed with mouse pre-osteoblasts (MC3T3-E1) and human bone marrow-derived mesenchymal stem cells (hBM-MSC) to evaluate the osteoinductive potential of PLA nanostructures. The results showed that nanofibrous (<100nm) membranes promoted the bone-related marker gene expression and matrix mineralization of MC3T3-E1 at 14days. Nanofibrous 3D matrices seeded with hBM-MSC without osteogenic induction supplements demonstrated a 2.5-fold increase in bone matrix deposition vs. the conventional microporous matrices after 14 and 21days. Antimicrobial nanofibers were further obtained by plasma-assisted coating of chitosan on PLA nanofibers. This study reveals a platform for fabricating novel biodegradable nanofibrous architecture, with potential in tissue regeneration.

  12. Chitosan-based membrane chromatography for protein adsorption and separation.

    PubMed

    Liu, Yezhuo; Feng, Zhicheng; Shao, Zhengzhong; Chen, Xin

    2012-08-01

    A chitosan-based membrane chromatography was set up by using natural chitosan/carboxymethylchitosan (CS/CMCS) blend membrane as the matrix. The dynamic adsorption property for protein (lysozyme as model protein) was detailed discussed with the change in pore size of the membrane, the flow rate and the initial concentration of the feed solution, and the layer of membrane in membrane stack. The best dynamic adsorption capacity of lysozyme on the CS/CMCS membrane chromatography was found to be 15.3mg/mL under the optimal flow conditions. Moreover, the CS/CMCS membrane chromatography exhibited good repeatability and reusability with the desorption efficiency of ~90%. As an application, lysozyme and ovalbumin were successfully separated from their binary mixture through the CS/CMCS membrane chromatography. This implies that such a natural chitosan-based membrane chromatography may have great potential on the bioseparation field in the future.

  13. Charge- and size-based separation of macromolecules using ultrathin silicon membranes.

    PubMed

    Striemer, Christopher C; Gaborski, Thomas R; McGrath, James L; Fauchet, Philippe M

    2007-02-15

    Commercial ultrafiltration and dialysis membranes have broad pore size distributions and are over 1,000 times thicker than the molecules they are designed to separate, leading to poor size cut-off properties, filtrate loss within the membranes, and low transport rates. Nanofabricated membranes have great potential in molecular separation applications by offering more precise structural control, yet transport is also limited by micrometre-scale thicknesses. This limitation can be addressed by a new class of ultrathin nanostructured membranes where the membrane is roughly as thick (approximately 10 nm) as the molecules being separated, but membrane fragility and complex fabrication have prevented the use of ultrathin membranes for molecular separations. Here we report the development of an ultrathin porous nanocrystalline silicon (pnc-Si) membrane using straightforward silicon fabrication techniques that provide control over average pore sizes from approximately 5 nm to 25 nm. Our pnc-Si membranes can retain proteins while permitting the transport of small molecules at rates an order of magnitude faster than existing materials, separate differently sized proteins under physiological conditions, and separate similarly sized molecules carrying different charges. Despite being only 15 nm thick, pnc-Si membranes that are free-standing over 40,000 microm2 can support a full atmosphere of differential pressure without plastic deformation or fracture. By providing efficient, low-loss macromolecule separations, pnc-Si membranes are expected to enable a variety of new devices, including membrane-based chromatography systems and both analytical and preparative microfluidic systems that require highly efficient separations.

  14. Charge- and size-based separation of macromolecules using ultrathin silicon membranes

    NASA Astrophysics Data System (ADS)

    Striemer, Christopher C.; Gaborski, Thomas R.; McGrath, James L.; Fauchet, Philippe M.

    2007-02-01

    Commercial ultrafiltration and dialysis membranes have broad pore size distributions and are over 1,000 times thicker than the molecules they are designed to separate, leading to poor size cut-off properties, filtrate loss within the membranes, and low transport rates. Nanofabricated membranes have great potential in molecular separation applications by offering more precise structural control, yet transport is also limited by micrometre-scale thicknesses. This limitation can be addressed by a new class of ultrathin nanostructured membranes where the membrane is roughly as thick (~10nm) as the molecules being separated, but membrane fragility and complex fabrication have prevented the use of ultrathin membranes for molecular separations. Here we report the development of an ultrathin porous nanocrystalline silicon (pnc-Si) membrane using straightforward silicon fabrication techniques that provide control over average pore sizes from approximately 5nm to 25nm. Our pnc-Si membranes can retain proteins while permitting the transport of small molecules at rates an order of magnitude faster than existing materials, separate differently sized proteins under physiological conditions, and separate similarly sized molecules carrying different charges. Despite being only 15nm thick, pnc-Si membranes that are free-standing over 40,000μm2 can support a full atmosphere of differential pressure without plastic deformation or fracture. By providing efficient, low-loss macromolecule separations, pnc-Si membranes are expected to enable a variety of new devices, including membrane-based chromatography systems and both analytical and preparative microfluidic systems that require highly efficient separations.

  15. Multiview video codec based on KTA techniques

    NASA Astrophysics Data System (ADS)

    Seo, Jungdong; Kim, Donghyun; Ryu, Seungchul; Sohn, Kwanghoon

    2011-03-01

    Multi-view video coding (MVC) is a video coding standard developed by MPEG and VCEG for multi-view video. It showed average PSNR gain of 1.5dB compared with view-independent coding by H.264/AVC. However, because resolutions of multi-view video are getting higher for more realistic 3D effect, high performance video codec is needed. MVC adopted hierarchical B-picture structure and inter-view prediction as core techniques. The hierarchical B-picture structure removes the temporal redundancy, and the inter-view prediction reduces the inter-view redundancy by compensated prediction from the reconstructed neighboring views. Nevertheless, MVC has inherent limitation in coding efficiency, because it is based on H.264/AVC. To overcome the limit, an enhanced video codec for multi-view video based on Key Technology Area (KTA) is proposed. KTA is a high efficiency video codec by Video Coding Expert Group (VCEG), and it was carried out for coding efficiency beyond H.264/AVC. The KTA software showed better coding gain than H.264/AVC by using additional coding techniques. The techniques and the inter-view prediction are implemented into the proposed codec, which showed high coding gain compared with the view-independent coding result by KTA. The results presents that the inter-view prediction can achieve higher efficiency in a multi-view video codec based on a high performance video codec such as HEVC.

  16. Stereoisomers Separation

    NASA Astrophysics Data System (ADS)

    Wieczorek, Piotr

    The use of capillary electrophoresis for enantiomer separation and optical purity determination is presented. The contents start with basic information about the nature of stereoizomers and the mechanism of enantioseparation using capillary electrophoresis techniques. The molecules to be separated show identical chemical structure and electrochemical behavior. Therefore, the chiral recognition of enantiomers is possible only by bonding to chiral selector and the separation based on very small differences in complexation energies of diastereomer complexes formed. This method is useful for this purpose due to the fact that different compounds can be used as chiral selectors. The mostly used chiral selectors like cyclodextrins, crown ethers, chiral surfactants, macrocyclic antibiotics, transition metal complexes, natural, and synthetic polymers and their application for this purpose is also discussed. Finally, examples of practical applications of electromigration techniques for enantiomers separation and determination are presented.

  17. Localized Ambient Solidity Separation Algorithm Based Computer User Segmentation.

    PubMed

    Sun, Xiao; Zhang, Tongda; Chai, Yueting; Liu, Yi

    2015-01-01

    Most of popular clustering methods typically have some strong assumptions of the dataset. For example, the k-means implicitly assumes that all clusters come from spherical Gaussian distributions which have different means but the same covariance. However, when dealing with datasets that have diverse distribution shapes or high dimensionality, these assumptions might not be valid anymore. In order to overcome this weakness, we proposed a new clustering algorithm named localized ambient solidity separation (LASS) algorithm, using a new isolation criterion called centroid distance. Compared with other density based isolation criteria, our proposed centroid distance isolation criterion addresses the problem caused by high dimensionality and varying density. The experiment on a designed two-dimensional benchmark dataset shows that our proposed LASS algorithm not only inherits the advantage of the original dissimilarity increments clustering method to separate naturally isolated clusters but also can identify the clusters which are adjacent, overlapping, and under background noise. Finally, we compared our LASS algorithm with the dissimilarity increments clustering method on a massive computer user dataset with over two million records that contains demographic and behaviors information. The results show that LASS algorithm works extremely well on this computer user dataset and can gain more knowledge from it.

  18. Localized Ambient Solidity Separation Algorithm Based Computer User Segmentation

    PubMed Central

    Sun, Xiao; Zhang, Tongda; Chai, Yueting; Liu, Yi

    2015-01-01

    Most of popular clustering methods typically have some strong assumptions of the dataset. For example, the k-means implicitly assumes that all clusters come from spherical Gaussian distributions which have different means but the same covariance. However, when dealing with datasets that have diverse distribution shapes or high dimensionality, these assumptions might not be valid anymore. In order to overcome this weakness, we proposed a new clustering algorithm named localized ambient solidity separation (LASS) algorithm, using a new isolation criterion called centroid distance. Compared with other density based isolation criteria, our proposed centroid distance isolation criterion addresses the problem caused by high dimensionality and varying density. The experiment on a designed two-dimensional benchmark dataset shows that our proposed LASS algorithm not only inherits the advantage of the original dissimilarity increments clustering method to separate naturally isolated clusters but also can identify the clusters which are adjacent, overlapping, and under background noise. Finally, we compared our LASS algorithm with the dissimilarity increments clustering method on a massive computer user dataset with over two million records that contains demographic and behaviors information. The results show that LASS algorithm works extremely well on this computer user dataset and can gain more knowledge from it. PMID:26221133

  19. Clogging-free microfluidics for continuous size-based separation of microparticles

    PubMed Central

    Yoon, Yousang; Kim, Seonil; Lee, Jusin; Choi, Jaewoong; Kim, Rae-Kwon; Lee, Su-Jae; Sul, Onejae; Lee, Seung-Beck

    2016-01-01

    In microfluidic filtration systems, one of the leading obstacles to efficient, continuous operation is clogging of the filters. Here, we introduce a lateral flow microfluidic sieving (μ-sieving) technique to overcome clogging and to allow continuous operation of filter based microfluidic separation. A low frequency mechanical oscillation was added to the fluid flow, which made possible the release of aggregated unwanted polystyrene (PS) particles trapped between the larger target PS particles in the filter demonstrating continuous μ-sieving operation. We achieved collection of the target PS particles with 100% separation efficiency. Also, on average, more than 98% of the filtered target particles were retrieved after the filtration showing high retrieval rates. Since the oscillation was applied to the fluid but not to the microfluidic filter system, mechanical stresses to the system was minimized and no additional fabrication procedures were necessary. We also applied the μ-sieving technique to the separation of cancer cells (MDA-MB-231) from whole blood and showed that the fluidic oscillations prevented the filters from being blocked by the filtered cancer cells allowing continuous microfluidic separation with high efficiency. PMID:27198601

  20. Expanded separation technique for chlorophyll metabolites in Oriental tobacco leaf using non aqueous reversed phase chromatography.

    PubMed

    Ishida, Naoyuki

    2011-08-26

    An improved separation method for chlorophyll metabolites in Oriental tobacco leaf was developed. While Oriental leaf still gives the green color even after the curing process, little attention has been paid to the detailed composition of the remaining green pigments. This study aimed to identify the green pigments using non aqueous reversed phase chromatography (NARPC). To this end, liquid chromatograph (LC) equipped with a photo diode array detector (DAD) and an atmospheric pressure chemical ionization/mass spectrometer (APCI/MSD) was selected, because it is useful for detecting low polar non-volatile compounds giving green color such as pheophytin a. Identification was based on the wavelength spectrum, mass spectrum and retention time, comparing the analytes in Oriental leaf with the commercially available and synthesized components. Consequently, several chlorophyll metabolites such as hydroxypheophytin a, solanesyl pheophorbide a and solanesyl hydroxypheophorbide a were newly identified, in addition to typical green pigments such as chlorophyll a and pheophytin a. Chlorophyll metabolites bound to solanesol were considered the tobacco specific components. NARPC expanded the number of detectable low polar chlorophyll metabolites in Oriental tobacco leaf.

  1. PVA-based tunable buffering membranes for isoelectric trapping separations.

    PubMed

    Fleisher-Craver, Helen C; Vigh, Gyula

    2008-11-01

    PVA-based buffering membranes with tunable pH values were prepared on a PVA substrate by reacting PVA, glycerol-1,3-diglycidyl ether, -NH2 group-containing buffers and -NH2 group-containing titrants in the presence of sodium hydroxide. The pH of the buffering membranes could be tuned in the 3separate proteins having a DeltapI as small as 0.1. The membranes were mechanically and hydrolytically stable and could be stored, even in 10

  2. Hydrate-based heavy metal separation from aqueous solution

    PubMed Central

    Song, Yongchen; Dong, Hongsheng; Yang, Lei; Yang, Mingjun; Li, Yanghui; Ling, Zheng; Zhao, Jiafei

    2016-01-01

    A novel hydrate-based method is proposed for separating heavy metal ions from aqueous solution. We report the first batch of experiments and removal characteristics in this paper, the effectiveness and feasibility of which are verified by Raman spectroscopy analysis and cross-experiment. 88.01–90.82% of removal efficiencies for Cr3+, Cu2+, Ni2+, and Zn2+ were obtained. Further study showed that higher R141b–effluent volume ratio contributed to higher enrichment factor and yield of dissociated water, while lower R141b–effluent volume ratio resulted in higher removal efficiency. This study provides insights into low-energy, intensive treatment of wastewater. PMID:26887357

  3. Introducing the concept of centergram. A new tool to squeeze data from separation techniques-mass spectrometry couplings.

    PubMed

    Erny, Guillaume L; Simó, Carolina; Cifuentes, Alejandro; Esteves, Valdemar I

    2014-02-21

    In separation techniques hyphenated to mass spectrometry (MS) the bulk from the separation step is continuously flowing into the mass spectrometer where the compounds, arriving at each separation time, are ionized and further separated based on their m/z ratio. An MS detector is recognized as being a universal detector, although it can also be a very selective instrument. In spite of these advantages, classical two dimensional representations from these hyphenated systems, such as those based on the base peak of electropherogram/chromatogram or on the total ion of electropherogram/chromatogram, usually hide a large number of features that if correctly assessed will show the presence of co-migrating species and/or the low abundant ones. The uses of peak picking algorithms to detect and measure as many peaks as possible from a dataset allow extracting much more information. However, a single migrating compound usually produces a multiplicity of ions, making difficult to differentiate peaks generated by the same compound from other peaks due e.g., to closely co-migrating/eluting species. In this work, a new representation is proposed and its usefulness demonstrated with experimental data from capillary electrophoresis-hyphenated to a time of flight mass spectrometer via an electrospray interface. This representation, called centergram, is obtained after using a peak picking methodology that detects electrophoretic peaks of single ions and measure their positions. The centergram is the histogram (i.e. the count of the number of observations that fall into each one of the intervals, known as bins, as determined by the user) of the measured positions. The intensity of the bars in this histogram will indicate the amount of peaks in the whole dataset whose centers are within each interval. As a compound that has been separated and has entered the MS instrument will produce multiple images at the same position along the m/z dimension, the centergram will exhibit a series of

  4. GC-Based Techniques for Breath Analysis: Current Status, Challenges, and Prospects.

    PubMed

    Xu, Mingjun; Tang, Zhentao; Duan, Yixiang; Liu, Yong

    2016-07-03

    Breath analysis is a noninvasive diagnostic method that profiles a person's physical state by volatile organic compounds in the breath. It has huge potential in the field of disease diagnosis. In order to offer opportunities for practical applications, various GC-based techniques have been investigated for on-line breath analysis since GC is the most preferred technique for mixed gas separation. This article reviews the development of breath analysis and GC-based techniques in basic breath research, involving sampling methods, preconcentration methods, conventional GC-based techniques, and newly developed GC techniques for breath analysis. The combination of GC and newly developed detection techniques takes advantages of the virtues of each. In addition, portable GC or micro GC are poised to become field GC-based techniques in breath analysis. Challenges faced in GC-based techniques for breath analysis are discussed candidly. Effective cooperation of experts from different fields is urgent to promote the development of breath analysis.

  5. Intact protein separation by chromatographic and/or electrophoretic techniques for top-down proteomics.

    PubMed

    Capriotti, Anna Laura; Cavaliere, Chiara; Foglia, Patrizia; Samperi, Roberto; Laganà, Aldo

    2011-12-09

    Mass spectrometry used in combination with a wide variety of separation methods is the principal methodology for proteomics. In bottom-up approach, proteins are cleaved with a specific proteolytic enzyme, followed by peptide separation and MS identification. In top-down approach intact proteins are introduced into the mass spectrometer. The ions generated by electrospray ionization are then subjected to gas-phase separation, fragmentation, fragment separation, and automated interpretation of mass spectrometric and chromatographic data yielding both the molecular weight of the intact protein and the protein fragmentation pattern. This approach requires high accuracy mass measurement analysers capable of separating the multi-charged isotopic cluster of proteins, such as hybrid ion trap-Fourier transform instruments (LTQ-FTICR, LTQ-Orbitrap). Front-end separation technologies tailored for proteins are of primary importance to implement top-down proteomics. This review intends to provide the state of art of protein chromatographic and electrophoretic separation methods suitable for MS coupling, and to illustrate both monodimensional and multidimensional approaches used for LC-MS top-down proteomics. In addition, some recent progresses in protein chromatography that may provide an alternative to those currently employed are also discussed.

  6. An osmolyte-based micro-volume ultrafiltration technique.

    PubMed

    Ghosh, Raja

    2014-12-07

    This paper discusses a novel, simple, and inexpensive micro-volume ultrafiltration technique for protein concentration, desalting, buffer exchange, and size-based protein purification. The technique is suitable for processing protein samples in a high-throughput mode. It utilizes a combination of capillary action, and osmosis for drawing water and other permeable species from a micro-volume sample droplet applied on the surface of an ultrafiltration membrane. A macromolecule coated on the permeate side of the membrane functions as the osmolyte. The action of the osmolyte could, if required, be augmented by adding a supersorbent polymer layer over the osmolyte. The mildly hydrophobic surface of the polymeric ultrafiltration membrane used in this study minimized sample droplet spreading, thus making it easy to recover the retained material after separation, without sample interference and cross-contamination. High protein recoveries were observed in the micro-volume ultrafiltration experiments described in the paper.

  7. Process for separating carbon dioxide from flue gas using sweep-based membrane separation and absorption steps

    DOEpatents

    Wijmans, Johannes G.; Baker, Richard W.; Merkel, Timothy C.

    2012-08-21

    A gas separation process for treating flue gases from combustion processes, and combustion processes including such gas separation. The invention involves routing a first portion of the flue gas stream to be treated to an absorption-based carbon dioxide capture step, while simultaneously flowing a second portion of the flue gas across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas to the combustor.

  8. Multiplexed Affinity-Based Separation of Proteins and Cells Using Inertial Microfluidics

    PubMed Central

    Sarkar, Aniruddh; Hou, Han Wei; Mahan, Alison. E.; Han, Jongyoon; Alter, Galit

    2016-01-01

    Isolation of low abundance proteins or rare cells from complex mixtures, such as blood, is required for many diagnostic, therapeutic and research applications. Current affinity-based protein or cell separation methods use binary ‘bind-elute’ separations and are inefficient when applied to the isolation of multiple low-abundance proteins or cell types. We present a method for rapid and multiplexed, yet inexpensive, affinity-based isolation of both proteins and cells, using a size-coded mixture of multiple affinity-capture microbeads and an inertial microfluidic particle sorter device. In a single binding step, different targets–cells or proteins–bind to beads of different sizes, which are then sorted by flowing them through a spiral microfluidic channel. This technique performs continuous-flow, high throughput affinity-separation of milligram-scale protein samples or millions of cells in minutes after binding. We demonstrate the simultaneous isolation of multiple antibodies from serum and multiple cell types from peripheral blood mononuclear cells or whole blood. We use the technique to isolate low abundance antibodies specific to different HIV antigens and rare HIV-specific cells from blood obtained from HIV+ patients. PMID:27026280

  9. Optical cell separation from three-dimensional environment in photodegradable hydrogels for pure culture techniques.

    PubMed

    Tamura, Masato; Yanagawa, Fumiki; Sugiura, Shinji; Takagi, Toshiyuki; Sumaru, Kimio; Matsui, Hirofumi; Kanamori, Toshiyuki

    2014-05-07

    Cell sorting is an essential and efficient experimental tool for the isolation and characterization of target cells. A three-dimensional environment is crucial in determining cell behavior and cell fate in biological analysis. Herein, we have applied photodegradable hydrogels to optical cell separation from a 3D environment using a computer-controlled light irradiation system. The hydrogel is composed of photocleavable tetra-arm polyethylene glycol and gelatin, which optimized cytocompatibility to adjust a composition of crosslinker and gelatin. Local light irradiation could degrade the hydrogel corresponding to the micropattern image designed on a laptop; minimum resolution of photodegradation was estimated at 20 µm. Light irradiation separated an encapsulated fluorescent microbead without any contamination of neighbor beads, even at multiple targets. Upon selective separation of target cells in the hydrogels, the separated cells have grown on another dish, resulting in pure culture. Cell encapsulation, light irradiation and degradation products exhibited negligible cytotoxicity in overall process.

  10. Separation techniques for the clean-up of radioactive mixed waste for ICP-AES/ICP-MS analysis

    SciTech Connect

    Swafford, A.M.; Keller, J.M.

    1993-03-17

    Two separation techniques were investigated for the clean-up of typical radioactive mixed waste samples requiring elemental analysis by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) or Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). These measurements frequently involve regulatory or compliance criteria which include the determination of elements on the EPA Target Analyte List (TAL). These samples usually consist of both an aqueous phase and a solid phase which is mostly an inorganic sludge. Frequently, samples taken from the waste tanks contain high levels of uranium and thorium which can cause spectral interferences in ICP-AES or ICP-MS analysis. The removal of these interferences is necessary to determine the presence of the EPA TAL elements in the sample. Two clean-up methods were studied on simulated aqueous waste samples containing the EPA TAL elements. The first method studied was a classical procedure based upon liquid-liquid extraction using tri-n- octylphosphine oxide (TOPO) dissolved in cyclohexane. The second method investigated was based on more recently developed techniques using extraction chromatography; specifically the use of a commercially available Eichrom TRU[center dot]Spec[trademark] column. Literature on these two methods indicates the efficient removal of uranium and thorium from properly prepared samples and provides considerable qualitative information on the extraction behavior of many other elements. However, there is a lack of quantitative data on the extraction behavior of elements on the EPA Target Analyte List. Experimental studies on these two methods consisted of determining whether any of the analytes were extracted by these methods and the recoveries obtained. Both methods produced similar results; the EPA target analytes were only slightly or not extracted. Advantages and disadvantages of each method were evaluated and found to be comparable.

  11. Stage Separation Failure: Model Based Diagnostics and Prognostics

    NASA Technical Reports Server (NTRS)

    Luchinsky, Dmitry; Hafiychuk, Vasyl; Kulikov, Igor; Smelyanskiy, Vadim; Patterson-Hine, Ann; Hanson, John; Hill, Ashley

    2010-01-01

    Safety of the next-generation space flight vehicles requires development of an in-flight Failure Detection and Prognostic (FD&P) system. Development of such system is challenging task that involves analysis of many hard hitting engineering problems across the board. In this paper we report progress in the development of FD&P for the re-contact fault between upper stage nozzle and the inter-stage caused by the first stage and upper stage separation failure. A high-fidelity models and analytical estimations are applied to analyze the following sequence of events: (i) structural dynamics of the nozzle extension during the impact; (ii) structural stability of the deformed nozzle in the presence of the pressure and temperature loads induced by the hot gas flow during engine start up; and (iii) the fault induced thrust changes in the steady burning regime. The diagnostic is based on the measurements of the impact torque. The prognostic is based on the analysis of the correlation between the actuator signal and fault-induced changes in the nozzle structural stability and thrust.

  12. Microchip separations-based sensors for cellular analysis

    NASA Astrophysics Data System (ADS)

    Manica, Drew Prentice

    The objective of this thesis has been to introduce and develop novel methods for microchip separations for bioanalytical applications. A novel detection scheme is introduced, involving simultaneous dual amperometric and fluorescence detection on a microchip. Dual detection is shown to increase selectivity and throughput, resolve co-migrating species that may be selectively detected, and provide a convenient means to normalize for the irreproducibility of migration times often encountered in CE applications. Such normalization is expected to facilitate the use of microchip CE to monitor biological samples, which are inclined to exacerbate the irreproducibility of migration times. The use of electrochemical detection presents a unique and fundamental challenge. An effective method for reproducibly regenerating a clean surface is demonstrated. The method is optimized and utilized to achieve high sensitivity even for highly adsorptive compounds, such as those released from mast cells. The development of an in-situ electrode-cleaning protocol is an essential step toward reliably monitoring cellular release on a microchip CEEC device. Two novel techniques are presented which are capable of producing disposable microanalytical systems on glass. Electrodes and channels produced with these methods exhibit performance characteristics that are comparable to examples in current literature. These techniques demonstrate the feasibility of manufacturing a disposable glass lab-on-a-chip, which may be used for cellular analysis or as a point-of-use sensor. Increased interest in analyzing biological samples has led to the development of a wide range of derivatizing agents for biological compounds such as amino acids and peptides. A common tag that is both fluorescent and electroactive is naphthalene-2,3-dicarboxaldehyde (NDA). While there has been much discussion regarding the stability of a similar compound, o-phthalaldehyde, there has been no discussion regarding the stability of

  13. Separation of phytochemicals from Helichrysum italicum: An analysis of different isolation techniques and biological activity of prepared extracts.

    PubMed

    Maksimovic, Svetolik; Tadic, Vanja; Skala, Dejan; Zizovic, Irena

    2017-06-01

    Helichrysum italicum presents a valuable source of natural bioactive compounds. In this work, a literature review of terpenes, phenolic compounds, and other less common phytochemicals from H. italicum with regard to application of different separation methods is presented. Data including extraction/separation methods and experimental conditions applied, obtained yields, number of identified compounds, content of different compound groups, and analytical techniques applied are shown as corresponding tables. Numerous biological activities of both isolates and individual compounds are emphasized. In addition, the data reported are discussed, and the directions for further investigations are proposed.

  14. Biomagnetic separation of Salmonella Typhimurium with high affine and specific ligand peptides isolated by phage display technique

    NASA Astrophysics Data System (ADS)

    Steingroewer, Juliane; Bley, Thomas; Bergemann, Christian; Boschke, Elke

    2007-04-01

    Analyses of food-borne pathogens are of great importance in order to minimize the health risk for customers. Thus, very sensitive and rapid detection methods are required. Current conventional culture techniques are very time consuming. Modern immunoassays and biochemical analysis also require pre-enrichment steps resulting in a turnaround time of at least 24 h. Biomagnetic separation (BMS) is a promising more rapid method. In this study we describe the isolation of high affine and specific peptides from a phage-peptide library, which combined with BMS allows the detection of Salmonella spp. with a similar sensitivity as that of immunomagnetic separation using antibodies.

  15. Electromagnetic Separation of Isotopes at Oak Ridge: An informal account of history, techniques, and accomplishments.

    PubMed

    Love, L O

    1973-10-26

    In 1960 I attended a European conference on isotope separation, after which I visited the Niels Bohr Institute in Copenhagen. A staff member there ventured the opinion that the separation of isotopes will be first on the list of important contributions to the peaceful uses of the atom when the Atomic Energy Commission's memoirs are written in the year 2000. In 1968 the AEC Division of Research contracted with the National Research Council of the National Academy of Sciences to conduct a review of the AEC program for the separation of stable isotopes by electromagnetic and thermal diffusion methods. This ad hoc panel comprised seven scientists from the fields of chemistry, classical physics, geochemistry, geophysics, medicine, and physics. In their final report on national uses and needs for separated stable isotopes (9), they referred to the store of separated isotopes as a "real national asset that attains increasing value as science and technology develop" and recommended "continuation of the program as a national resource of great value to the United States." Later, in a discussion of this report with A. M. Weinberg, J. Koch, himself a pioneer in electromagnetic isotope separation and member of the Danish Atomic Energy Program, said he would correct the statement that the Oak Ridge electromagnetic facility is a "national asset" to read "international asset." From my narrow viewpoint after an extended and complete engrossment with this program for so many years, it is gratifying to learn that such men as those mentioned above share my belief that the work has indeed been worthwhile.

  16. Proteomic changes in bovine heart mitochondria with age: using a novel technique for organelle separation and enrichment.

    PubMed

    Kiri, Ajay N; Tran, Hung-Cuong; Drahos, Kate L; Lan, Wenkui; McRorie, Donald K; Horn, Marcus J

    2005-12-01

    Separation and enrichment of organelles from complex biological mixtures are important for proteomic analysis. Two widely used current standard techniques to isolate individual organelles include differential and density-gradient centrifugation. Although these techniques have proven useful for processing small volumes of sample, multiple rounds of centrifugation are required when performing a large-scale purification. In this report, we have introduced a novel technique: continuous-flow ultracentrifugation using a sucrose gradient to separate, accumulate, and highly enrich bovine heart mitochondria in one step. To demonstrate the advantage of the technique, mitochondrial proteins from two different bovine hearts (3-8 mo and 18-30 mo old) were examined. For each age group, 100 g of bovine heart tissue were homogenized by a blending procedure. After removal of the nuclei, the entire remaining homogenate was loaded onto a proteomics continuous-flow ultracentrifuge to separate and enrich the organelles. Fractions were collected and mitochondria-enriched fractions were identified by Western blot analysis. To study the protein profile changes with aging in the mitochondrial proteome, the mitochondria-enriched fractions were applied to two-dimensional gel electrophoresis. The resulting two-dimensional PAGE gels were subsequently analyzed by image analysis software to identify proteins unique to each age group and proteins with at least twofold differences in protein expression. These proteins were then digested with trypsin and identified by mass spectrometer. Significant differences in the protein profiles of the two differently aged mitochondria preparations were found. The continuous-flow ultracentrifugation technique was demonstrated to be a powerful tool for separation and enrichment of organelles and their sub-types.

  17. Experimental Studies of Surface-Driven Capillary Flow in PMMA Microfluidic Devices Prepared by Direct Bonding Technique and Passive Separation of Microparticles in Microfluidic Laboratory-On Systems

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Subhadeep; Banerjee, J. P.; Mathur, Ashish; Tweedie, M.; McLaughlin, J. A.; Roy, Susanta Sinha

    2015-05-01

    Proper bonding technique is investigated to achieve leakage-free surface-driven capillary flow in polymethylmethacrylate (PMMA) microfluidic devices. SU-8-based silicon stamp is fabricated by maskless lithography. This stamp is used to produce PMMA microchannel structure by hot embossing lithography. A direct bonding technique is mainly employed for leakage-free sealing inside PMMA microfluidic devices. The effect of surface wettability on surface-driven capillary flow is also investigated in PMMA microfluidic devices. The separation of polystyrene microparticles in PMMA laboratory-on-a-chip systems is investigated with the reduction of separation time by air dielectric barrier discharge (DBD) plasma processing of channel surfaces. This study is useful to fabricate the microfluidic laboratory-on-a-chip systems and to understand the surface-driven capillary flow.

  18. RBF-based technique for statistical demodulation of pathological tremor.

    PubMed

    Gianfelici, Francesco

    2013-10-01

    This paper presents an innovative technique based on the joint approximation capabilities of radial basis function (RBF) networks and the estimation capability of the multivariate iterated Hilbert transform (IHT) for the statistical demodulation of pathological tremor from electromyography (EMG) signals in patients with Parkinson's disease. We define a stochastic model of the multichannel high-density surface EMG by means of the RBF networks applied to the reconstruction of the stochastic process (characterizing the disease) modeled by the multivariate relationships generated by the Karhunen-Loéve transform in Hilbert spaces. Next, we perform a demodulation of the entire random field by means of the estimation capability of the multivariate IHT in a statistical setting. The proposed method is applied to both simulated signals and data recorded from three Parkinsonian patients and the results show that the amplitude modulation components of the tremor oscillation can be estimated with signal-to-noise ratio close to 30 dB with root-mean-square error for the estimates of the tremor instantaneous frequency. Additionally, the comparisons with a large number of techniques based on all the combinations of the RBF, extreme learning machine, backpropagation, support vector machine used in the first step of the algorithm; and IHT, empirical mode decomposition, multiband energy separation algorithm, periodic algebraic separation and energy demodulation used in the second step of the algorithm, clearly show the effectiveness of our technique. These results show that the proposed approach is a potential useful tool for advanced neurorehabilitation technologies that aim at tremor characterization and suppression.

  19. Separations techniques for recovery and/or removal of toxic metals from spent textile dyebaths

    SciTech Connect

    Babocsi, E.E.; Hallen, R.T.

    1994-02-01

    The Textile Resource Conservation Project (TReC) is a major initiative of the American Textile Partnership (AMTEX) focusing on energy and the environment. The largest proposed project in the TReC is Raw Material Recovery and Reuse. The main task within the Raw Material Recovery and Reuse Project is Textile Chemical Recovery. The initial focus of this task is the separation/removal of colorants from solution. Screening studies were performed at a number of US Department of Energy National Laboratories to identify promising technologies for the treatment and recovery of dyes containing toxic metals. These dyes were chosen because of the environmental concern associated with their disposal. The research group at Pacific Northwest Laboratory (PNL) took two approaches to the removal and recovery of the toxic metals in the dyes. One approach was to react or destroy the organic fraction of the dye, releasing the metals for conventional separation such as ion exchange. PNL evaluated the Rapid Thermal Decomposition of precursors in Solution (RTDS) and Corona Discharge processes for metal release. The other approach was to separate and concentrate the dye, metal-complex intact, from the bulk of the spent solution. Membrane separation was evaluated for recovery of the dyes with the metals left intact. The RTDS process was found to be effective for destroying color and releasing or precipitating metals for recovery. Corona Discharge was effective at selectively destroying color, but the metals were not sufficiently released to allow recovery with a chelating resin. Ultrafiltration membranes were effective for separating and recovering the metal-containing dye as a potentially reusable concentrated stream.

  20. A Time Series Separation and Reconstruction (TSSR) Technique to Estimate Daily Suspended Sediment Concentrations

    EPA Science Inventory

    High suspended sediment concentrations (SSCs) from natural and anthropogenic sources are responsible for biological impairments of many streams, rivers, lakes, and estuaries, but techniques to estimate sediment concentrations or loads accurately at the daily temporal resolution a...

  1. A TRUEX-based separation of americium from the lanthanides

    SciTech Connect

    Bruce J. Mincher; Nicholas C. Schmitt; Mary E. Case

    2011-03-01

    Abstract: The inextractability of the actinide AnO2+ ions in the TRUEX process suggests the possibility of a separation of americium from the lanthanides using oxidation to Am(V). The only current method for the direct oxidation of americium to Am(V) in strongly acidic media is with sodium bismuthate. We prepared Am(V) over a wide range of nitric acid concentrations and investigated its solvent extraction behavior for comparison to europium. While a separation is achievable in principal, the presence of macro amounts of cerium competes for the sparingly soluble oxidant and the oxidant itself competes for CMPO complexation. These factors conspire to reduce the Eu/Am separation factor from ~40 using tracer solutions to ~5 for extractions from first cycle raffinate simulant solution. To separate pentavalent americium directly from the lanthanides using the TRUEX process, an alternative oxidizing agent will be necessary.

  2. Analytical-scale separations of lanthanides : a review of techniques and fundamentals.

    SciTech Connect

    Nash, K. L.; Jensen, M. P.

    1999-10-27

    Separations chemistry is at the heart of most analytical procedures to determine the rare earth content of both man-made and naturally occurring materials. Such procedures are widely used in mineral exploration, fundamental geology and geochemistry, material science, and in the nuclear industry. Chromatographic methods that rely on aqueous solutions containing complexing agents sensitive to the lanthanide cationic radius and cation-exchange phase transfer reactions (using a variety of different solid media) have enjoyed the greatest success for these procedures. In this report, they will briefly summarize the most important methods for completing such analyses. they consider in some detail the basic aqueous (and two-phase) solution chemistry that accounts for separations that work well and offer explanations for why others are less successful.

  3. Blind Source Separation Techniques for the Decomposition of Multiply Labeled Fluorescence Images

    PubMed Central

    Neher, Richard A.; Mitkovski, Mišo; Kirchhoff, Frank; Neher, Erwin; Theis, Fabian J.; Zeug, André

    2009-01-01

    Methods of blind source separation are used in many contexts to separate composite data sets according to their sources. Multiply labeled fluorescence microscopy images represent such sets, in which the sources are the individual labels. Their distributions are the quantities of interest and have to be extracted from the images. This is often challenging, since the recorded emission spectra of fluorescent dyes are environment- and instrument-specific. We have developed a nonnegative matrix factorization (NMF) algorithm to detect and separate spectrally distinct components of multiply labeled fluorescence images. It operates on spectrally resolved images and delivers both the emission spectra of the identified components and images of their abundance. We tested the proposed method using biological samples labeled with up to four spectrally overlapping fluorescent labels. In most cases, NMF accurately decomposed the images into contributions of individual dyes. However, the solutions are not unique when spectra overlap strongly or when images are diffuse in their structure. To arrive at satisfactory results in such cases, we extended NMF to incorporate preexisting qualitative knowledge about spectra and label distributions. We show how data acquired through excitations at two or three different wavelengths can be integrated and that multiple excitations greatly facilitate the decomposition. By allowing reliable decomposition in cases where the spectra of the individual labels are not known or are known only inaccurately, the proposed algorithms greatly extend the range of questions that can be addressed with quantitative microscopy. PMID:19413985

  4. A frequency-control particle separation device based on resultant effects of electroosmosis and dielectrophoresis

    NASA Astrophysics Data System (ADS)

    Lin, Shiang-Chi; Tung, Yi-Chung; Lin, Chih-Ting

    2016-08-01

    Particle separation plays an important role in microfluidic sample preparation for various biomedical applications. In this paper, we report a particle manipulation and separation scheme using a microfluidic device based on low-volume/low-voltage electrokinetic frequency modulation. Utilizing a circular micro-electrode array, both electroosmosis and dielectrophoresis can be contributed to manipulate particles in the device by controlling the frequency of applied sinusoidal travelling wave signals. Theoretical simulations based on finite-element methods are employed to establish fundamental understanding of the developed scheme. For experimental demonstration, polystyrene beads (6 μm in diameter) and human promyelocytic leukaemia cells (HL-60) are used to validate the frequency-modulation effect. Furthermore, different diameter polystyrene beads (6 μm and 10 μm in diameter) are mixed to show potentials of precise particle separations (˜90% efficiency) by the reported frequency-controlled electrokinetic device. The developed technique can be exploited as an actuation scheme and particle manipulation method for microfluidic sample preparations of low ionic concentration samples.

  5. Entropy-based separation of yeast cells using a microfluidic system of conjoined spheres

    SciTech Connect

    Huang, Kai-Jian; Qin, S.-J. Bai, Zhong-Chen; Zhang, Xin; Mai, John D.

    2013-11-21

    A physical model is derived to create a biological cell separator that is based on controlling the entropy in a microfluidic system having conjoined spherical structures. A one-dimensional simplified model of this three-dimensional problem in terms of the corresponding effects of entropy on the Brownian motion of particles is presented. This dynamic mechanism is based on the Langevin equation from statistical thermodynamics and takes advantage of the characteristics of the Fokker-Planck equation. This mechanism can be applied to manipulate biological particles inside a microfluidic system with identical, conjoined, spherical compartments. This theoretical analysis is verified by performing a rapid and a simple technique for separating yeast cells in these conjoined, spherical microfluidic structures. The experimental results basically match with our theoretical model and we further analyze the parameters which can be used to control this separation mechanism. Both numerical simulations and experimental results show that the motion of the particles depends on the geometrical boundary conditions of the microfluidic system and the initial concentration of the diffusing material. This theoretical model can be implemented in future biophysics devices for the optimized design of passive cell sorters.

  6. Assessment of Carbon- and Metal-Based Nanoparticle DNA Damage with Microfluidic Electrophoretic Separation Technology.

    PubMed

    Schrand, Amanda M; Powell, Thomas; Robertson, Tiffany; Hussain, Saber M

    2015-02-01

    In this study, we examined the feasibility of extracting DNA from whole cell lysates exposed to nanoparticles using two different methodologies for evaluation of fragmentation with microfluidic electrophoretic separation. Human lung macrophages were exposed to five different carbon- and metal-based nanoparticles at two different time points (2 h, 24 h) and two different doses (5 µg/ml, 100 µg/ml). The primary difference in the banding patterns after 2 h of nanoparticle exposure is more DNA fragmentation at the higher NP concentration when examining cells exposed to nanoparticles of the same composition. However, higher doses of carbon and silver nanoparticles at both short and long dosing periods can contribute to erroneous or incomplete data with this technique. Also comparing DNA isolation methodologies, we recommend the centrifugation extraction technique, which provides more consistent banding patterns in the control samples compared to the spooling technique. Here we demonstrate that multi-walled carbon nanotubes, 15 nm silver nanoparticles and the positive control cadmium oxide cause similar DNA fragmentation at the short time point of 2 h with the centrifugation extraction technique. Therefore, the results of these studies contribute to elucidating the relationship between nanoparticle physicochemical properties and DNA fragmentation results while providing the pros and cons of altering the DNA isolation methodology. Overall, this technique provides a high throughput way to analyze subcellular alterations in DNA profiles of cells exposed to nanomaterials to aid in understanding the consequences of exposure and mechanistic effects. Future studies in microfluidic electrophoretic separation technologies should be investigated to determine the utility of protein or other assays applicable to cellular systems exposed to nanoparticles.

  7. Stormflow-hydrograph separation based on isotopes: the thrill is gone--what's next?

    USGS Publications Warehouse

    Burns, Douglas A.

    2002-01-01

    Beginning in the 1970s, the promise of a new method for separatingstormflow hydrographs using18O,2H, and3Hprovedanirresistibletemptation, and was a vast improvement over graphical separationand solute tracer methods that were prevalent at the time. Eventu-ally, hydrologists realized that this new method entailed a plethoraof assumptions about temporal and spatial homogeneity of isotopiccomposition (many of which were commonly violated). Nevertheless,hydrologists forged ahead with dozens of isotope-based hydrograph-separation studies that were published in the 1970s and 1980s.Hortonian overland flow was presumed dead. By the late 1980s,the new isotope-based hydrograph separation technique had movedinto adolescence, accompanied by typical adolescent problems suchas confusion and a search for identity. As experienced hydrologistscontinued to use the isotope technique to study stormflow hydrol-ogy in forested catchments in humid climates, their younger peersfollowed obligingly—again and again. Was Hortonian overland flowreally dead and forgotten, though? What about catchments in whichpeople live and work? And what about catchments in dry climatesand the tropics? How useful were study results when several of theassumptions about the homogeneity of source waters were commonlyviolated? What if two components could not explain the variation ofisotopic composition measured in the stream during stormflow? Andwhat about uncertainty? As with many new tools, once the initialshine wore off, the limitations of the method became a concern—oneof which was that isotope-based hydrograph separations alone couldnot reveal much about the flow paths by which water arrives at astream channel during storms.

  8. Separation of the atmospheric variability into non-Gaussian multidimensional sources by projection pursuit techniques

    NASA Astrophysics Data System (ADS)

    Pires, Carlos A. L.; Ribeiro, Andreia F. S.

    2017-02-01

    We develop an expansion of space-distributed time series into statistically independent uncorrelated subspaces (statistical sources) of low-dimension and exhibiting enhanced non-Gaussian probability distributions with geometrically simple chosen shapes (projection pursuit rationale). The method relies upon a generalization of the principal component analysis that is optimal for Gaussian mixed signals and of the independent component analysis (ICA), optimized to split non-Gaussian scalar sources. The proposed method, supported by information theory concepts and methods, is the independent subspace analysis (ISA) that looks for multi-dimensional, intrinsically synergetic subspaces such as dyads (2D) and triads (3D), not separable by ICA. Basically, we optimize rotated variables maximizing certain nonlinear correlations (contrast functions) coming from the non-Gaussianity of the joint distribution. As a by-product, it provides nonlinear variable changes `unfolding' the subspaces into nearly Gaussian scalars of easier post-processing. Moreover, the new variables still work as nonlinear data exploratory indices of the non-Gaussian variability of the analysed climatic and geophysical fields. The method (ISA, followed by nonlinear unfolding) is tested into three datasets. The first one comes from the Lorenz'63 three-dimensional chaotic model, showing a clear separation into a non-Gaussian dyad plus an independent scalar. The second one is a mixture of propagating waves of random correlated phases in which the emergence of triadic wave resonances imprints a statistical signature in terms of a non-Gaussian non-separable triad. Finally the method is applied to the monthly variability of a high-dimensional quasi-geostrophic (QG) atmospheric model, applied to the Northern Hemispheric winter. We find that quite enhanced non-Gaussian dyads of parabolic shape, perform much better than the unrotated variables in which concerns the separation of the four model's centroid regimes

  9. Localized modes of the Hirota equation: Nth order rogue wave and a separation of variable technique

    NASA Astrophysics Data System (ADS)

    Mu, Gui; Qin, Zhenyun; Chow, Kwok Wing; Ee, Bernard K.

    2016-10-01

    The Hirota equation is a special extension of the intensively studied nonlinear Schrödinger equation, by incorporating third order dispersion and one form of the self-steepening effect. Higher order rogue waves of the Hirota equation can be calculated theoretically through a Darboux-dressing transformation by a separation of variable approach. A Taylor expansion is used and no derivative calculation is invoked. Furthermore, stability of these rogue waves is studied computationally. By tracing the evolution of an exact solution perturbed by random noise, it is found that second order rogue waves are generally less stable than first order ones.

  10. 100% foundry compatible packaging and full wafer release and die separation technique for surface micromachined devices

    SciTech Connect

    OLIVER,ANDREW D.; MATZKE,CAROLYN M.

    2000-04-06

    A completely foundry compatible chip-scale package for surface micromachines has been successfully demonstrated. A pyrex (Corning 7740) glass cover is placed over the released surface micromachined die and anodically bonded to a planarized polysilicon bonding ring. Electrical feedthroughs for the surface micromachine pass underneath the polysilicon sealing ring. The package has been found to be hermetic with a leak rate of less than 5 x 10{sup {minus}8} atm cm{sup {minus}3}/s. This technology has applications in the areas of hermetic encapsulation and wafer level release and die separation.

  11. Plasma separation: physical separation at the molecular level

    NASA Astrophysics Data System (ADS)

    Gueroult, Renaud; Rax, Jean-Marcel; Fisch, Nathaniel J.

    2016-09-01

    Separation techniques are usually divided in two categories depending on the nature of the discriminating property: chemical or physical. Further to this difference, physical and chemical techniques differ in that chemical separation typically occurs at the molecular level, while physical separation techniques commonly operate at the macroscopic scale. Separation based on physical properties can in principle be realized at the molecular or even atomic scale by ionizing the mixture. This is in essence plasma based separation. Due to this fundamental difference, plasma based separation stands out from other separation techniques, and features unique properties. In particular, plasma separation allows separating different elements or chemical compounds based on physical properties. This could prove extremely valuable to separate macroscopically homogeneous mixtures made of substances of similar chemical formulation. Yet, the realization of plasma separation techniques' full potential requires identifying and controlling basic mechanisms in complex plasmas which exhibit suitable separation properties. In this paper, we uncover the potential of plasma separation for various applications, and identify the key physics mechanisms upon which hinges the development of these techniques.

  12. Protein elasticity probed with two synchrotron-based techniques.

    PubMed

    Leu, Bogdan M; Alatas, Ahmet; Sinn, Harald; Alp, E Ercan; Said, Ayman H; Yavaş, Hasan; Zhao, Jiyong; Sage, J Timothy; Sturhahn, Wolfgang

    2010-02-28

    Compressibility characterizes three interconnecting properties of a protein: dynamics, structure, and function. The compressibility values for the electron-carrying protein cytochrome c and for other proteins, as well, available in the literature vary considerably. Here, we apply two synchrotron-based techniques--nuclear resonance vibrational spectroscopy and inelastic x-ray scattering--to measure the adiabatic compressibility of this protein. This is the first report of the compressibility of any material measured with this method. Unlike the methods previously used, this novel approach probes the protein globally, at ambient pressure, does not require the separation of protein and solvent contributions to the total compressibility, and uses samples that contain the heme iron, as in the native state. We show, by comparing our results with molecular dynamics predictions, that the compressibility is almost independent of temperature. We discuss potential applications of this method to other materials beyond proteins.

  13. Protein elasticity probed with two synchrotron-based techniques.

    SciTech Connect

    Leu, B. M.; Alatas, A.; Sinn, H.; Alp, E. E.; Said, A.; Yavas, H.; Zhao, J.; Sage, J. T.; Sturhahn, W.; X-Ray Science Division; Hasylab; Northeastern Univ.

    2010-02-25

    Compressibility characterizes three interconnecting properties of a protein: dynamics, structure, and function. The compressibility values for the electron-carrying protein cytochrome c and for other proteins, as well, available in the literature vary considerably. Here, we apply two synchrotron-based techniques - nuclear resonance vibrational spectroscopy and inelastic x-ray scattering - to measure the adiabatic compressibility of this protein. This is the first report of the compressibility of any material measured with this method. Unlike the methods previously used, this novel approach probes the protein globally, at ambient pressure, does not require the separation of protein and solvent contributions to the total compressibility, and uses samples that contain the heme iron, as in the native state. We show, by comparing our results with molecular dynamics predictions, that the compressibility is almost independent of temperature. We discuss potential applications of this method to other materials beyond proteins.

  14. Using Essential Oils to Teach Advanced-Level Organic Chemistry Separation Techniques and Spectroscopy

    ERIC Educational Resources Information Center

    Bott, Tina M.; Wan, Hayley

    2013-01-01

    Students sometimes have difficulty grasping the importance of when and how basic distillation techniques, column chromatography, TLC, and basic spectroscopy (IR and NMR) can be used to identify unknown compounds within a mixture. This two-part experiment uses mixtures of pleasant-smelling, readily available terpenoid compounds as unknowns to…

  15. Evaporation-based Ge/.sup.68 Ga Separation

    DOEpatents

    Mirzadeh, Saed; Whipple, Richard E.; Grant, Patrick M.; O'Brien, Jr., Harold A.

    1981-01-01

    Micro concentrations of .sup.68 Ga in secular equilibrium with .sup.68 Ge in strong aqueous HCl solution may readily be separated in ionic form from the .sup.68 Ge for biomedical use by evaporating the solution to dryness and then leaching the .sup.68 Ga from the container walls with dilute aqueous solutions of HCl or NaCl. The chloro-germanide produced during the evaporation may be quantitatively recovered to be used again as a source of .sup.68 Ga. If the solution is distilled to remove any oxidizing agents which may be present as impurities, the separation factor may easily exceed 10.sup.5. The separation is easily completed and the .sup.68 Ga made available in ionic form in 30 minutes or less.

  16. Fetoscopic Amniotic Band Release in a Case of Chorioamniotic Separation: An Innovative New Technique

    PubMed Central

    Belfort, Michael A.; Whitehead, William E.; Ball, Robert; Silver, Robert; Shamshirsaz, Alireza; Ruano, Rodrigo; Espinoza, Jimmy; Becker, Judith; Olutoye, Olutoyin; Hollier, Larry

    2016-01-01

    Introduction Fetoscopic release of amniotic bands has proved its life- and limb-saving potential. Rupture of the amnion and separation of chorion from the amnion and uterine wall can however preclude the standard fetoscopic approach to release the amniotic bands using a single port. Methods and Materials A 28-year-old G1P0 woman was referred to our unit at 19 weeks due to amniotic band syndrome involving the left ankle, the infrapatellar region of the right leg, and the umbilical cord. Of note, part of the fetus was seen outside the amniotic cavity by ultrasonography and the left ankle and foot were severely swollen. The patient underwent a laparotomy and fetoscopic release of the amniotic bands as well as partial amnionectomy using two uterine ports and CO2 as distention. Results The surgery and postoperative recovery course were uneventful. At 341/7 weeks the patient went into labor, which was augmented resulting vaginal delivery of a 2,460-g male infant. The infant was noted to have a shallow skin indentation on the left lower extremity near the ankle. The infant was discharged in excellent condition. Conclusion In those cases where release of an amniotic band is impossible due to membrane separation, surgery in a CO2-filled uterus offers an option. PMID:27298754

  17. Separation and preconcentration of aluminum in parenteral solutions and bottled mineral water using different analytical techniques.

    PubMed

    Kazi, Tasneem G; Khan, Sumaira; Baig, Jameel A; Kolachi, Nida F; Afridi, Hassan I; Kandhro, Ghulam A; Kumar, Sham; Shah, Abdul Q

    2009-12-30

    A new method is reported for the separation of aluminum ions [Al(III)] from interfering elements in parenteral and pharmaceutical solutions (PS) and bottled mineral water (BMW) samples, through solid-phase extraction with 2-methyl-8-hydroxyquinoline (quinaldine) adsorbed onto activated silica gel. While the enrichment step of separated Al(III) was carried out by cloud point extraction (CPE) using 8-hydroxyquinoline as complexing reagent, the resulted complex was entrapped in a non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114). The enriched Al(III) in sample solutions were determined by spectrofluorometry (SPF) at lambda(excitation) 370 nm and lambda(emission) 510 nm, and flame atomic absorption spectrometry (FAAS) for comparative purpose. The variables affecting the complexation and extraction steps were studied and optimized. The validity of methodology was checked with certified reference material of water and standard addition method. The enrichment factor and detection limit of Al(III) for the preconcentration of 50 ml of PS and BMW were found to be 100 and 0.25 microg/L, respectively. The proposed method has been applied for the determination of trace amount of Al(III) in PS and BMW samples with satisfactory results. In PS the levels of Al(III) are above than permissible limit (25 microg/L).

  18. Kinetics study of phase separation in polyacrylic acid/nematic LC system by optical technique

    NASA Astrophysics Data System (ADS)

    Mucha, Maria; Krolikowski, Z.

    2002-06-01

    Thin polymer layers containing liquid crystal LC of non- linear optical properties were obtained from polyacrylic acid. Samples were produced by phase separation as a consequence of chemical polymerization (PIPS method) resulting in precipitation of liquid crystals in the form of droplets in a polymer matrix being formed. Films were produced in variable conditions of polymerization time and temperature and different content of an initiator (1 - 3 wt%). They contained of 10 - 40 wt% of LC. The cell thickness was constant and equal to 20 micrometers . Systems obtained in this way were subjected to thermo-optical and electro-optical studies, morphological structure investigation and DSC analysis. The polymerization time has a significant influence on the size and number of LC droplets. The presence of benzoyl peroxide can cause partial destruction of LC properties which is reflected by a decrease of isotropization temperature TI of the liquid crystal. An increase of the initiator amount shortens the time of polymerization (ti), while process enthalpy ((Delta) H) increases. Hence, the liquid crystal separation time decreases as well. Films prepared by this method present good electro-optical properties. Rise and decay times of orientation are short and equal to 2 - 17 ms (depending on driving voltage applied) and about 80 ms, respectively. Threshold voltage for the best sample is equal to 5 V. Optimal conditions are found: LC content equals 20%, wt(i) equals 1%, polymerization temperature Tp equals 100 - 110 degree(s)C.

  19. NOTE: Entropy-based automated classification of independent components separated from fMCG

    NASA Astrophysics Data System (ADS)

    Comani, S.; Srinivasan, V.; Alleva, G.; Romani, G. L.

    2007-03-01

    Fetal magnetocardiography (fMCG) is a noninvasive technique suitable for the prenatal diagnosis of the fetal heart function. Reliable fetal cardiac signals can be reconstructed from multi-channel fMCG recordings by means of independent component analysis (ICA). However, the identification of the separated components is usually accomplished by visual inspection. This paper discusses a novel automated system based on entropy estimators, namely approximate entropy (ApEn) and sample entropy (SampEn), for the classification of independent components (ICs). The system was validated on 40 fMCG datasets of normal fetuses with the gestational age ranging from 22 to 37 weeks. Both ApEn and SampEn were able to measure the stability and predictability of the physiological signals separated with ICA, and the entropy values of the three categories were significantly different at p <0.01. The system performances were compared with those of a method based on the analysis of the time and frequency content of the components. The outcomes of this study showed a superior performance of the entropy-based system, in particular for early gestation, with an overall ICs detection rate of 98.75% and 97.92% for ApEn and SampEn respectively, as against a value of 94.50% obtained with the time-frequency-based system.

  20. Recovery of Escherichia coli O157:H7 by immunomagnetic separation techniques and potential for regrowth in finished composts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: Mature, finished compost made from various feedstocks should undergo testing for the presence of Escherichia coli O157:H7 to ensure thermal destruction of the pathogen during composting. Immunomagnetic separation (IMS) –based methods may provide an assay which can be conducted within...

  1. Primary Energy Efficiency Analysis of Different Separate Sensible and Latent Cooling Techniques

    SciTech Connect

    Abdelaziz, Omar

    2015-01-01

    Separate Sensible and Latent cooling (SSLC) has been discussed in open literature as means to improve air conditioning system efficiency. The main benefit of SSLC is that it enables heat source optimization for the different forms of loads, sensible vs. latent, and as such maximizes the cycle efficiency. In this paper I use a thermodynamic analysis tool in order to analyse the performance of various SSLC technologies including: multi-evaporators two stage compression system, vapour compression system with heat activated desiccant dehumidification, and integrated vapour compression with desiccant dehumidification. A primary coefficient of performance is defined and used to judge the performance of the different SSLC technologies at the design conditions. Results showed the trade-off in performance for different sensible heat factor and regeneration temperatures.

  2. A study of heart sound and lung sound separation by independent component analysis technique.

    PubMed

    Chien, Jen-Chien; Huang, Ming-Chuan; Lin, Yue-Der; Chong, Fok-ching

    2006-01-01

    In the hospital, using percussion and auscultation are the most common ways for physical examination. Recently, in order to develop tele-medicine and home care system and to assist physician getting better auscultation results; electric stethoscope and computer analysis have become an inevitable trend. However, two important physical signals heart sound and lung sound recorded from chest overlap on spectrum chart. Therefore, in order to reduce human factor (ex. misplace or untrained of using) and minimize correlated effect in computer analysis; it's necessary for separated heart sound and lung sound. Independent component analysis can divide these sounds efficiency. In this paper, we use two microphones to collect signals from left and right chest. We have successfully divide heart and lung sounds by fast ICA algorithm. Therefore, it can assist physician examine and also using on tele-medicine and home care by this way.

  3. Risk-Based Causal Modeling of Airborne Loss of Separation

    NASA Technical Reports Server (NTRS)

    Geuther, Steven C.; Shih, Ann T.

    2015-01-01

    Maintaining safe separation between aircraft remains one of the key aviation challenges as the Next Generation Air Transportation System (NextGen) emerges. The goals of the NextGen are to increase capacity and reduce flight delays to meet the aviation demand growth through the 2025 time frame while maintaining safety and efficiency. The envisioned NextGen is expected to enable high air traffic density, diverse fleet operations in the airspace, and a decrease in separation distance. All of these factors contribute to the potential for Loss of Separation (LOS) between aircraft. LOS is a precursor to a potential mid-air collision (MAC). The NASA Airspace Operations and Safety Program (AOSP) is committed to developing aircraft separation assurance concepts and technologies to mitigate LOS instances, therefore, preventing MAC. This paper focuses on the analysis of causal and contributing factors of LOS accidents and incidents leading to MAC occurrences. Mid-air collisions among large commercial aircraft are rare in the past decade, therefore, the LOS instances in this study are for general aviation using visual flight rules in the years 2000-2010. The study includes the investigation of causal paths leading to LOS, and the development of the Airborne Loss of Separation Analysis Model (ALOSAM) using Bayesian Belief Networks (BBN) to capture the multi-dependent relations of causal factors. The ALOSAM is currently a qualitative model, although further development could lead to a quantitative model. ALOSAM could then be used to perform impact analysis of concepts and technologies in the AOSP portfolio on the reduction of LOS risk.

  4. Nuclear based techniques for detection of contraband

    SciTech Connect

    Gozani, T.

    1993-12-31

    The detection of contraband such as explosives and drugs concealed in luggage or other container can be quite difficult. Nuclear techniques offer capabilities which are essential to having effective detection devices. This report describes the features of various nuclear techniques and instrumentation.

  5. Thermal stability and separation characteristics of anti-sticking layers of Pt/Cr films for the hot slumping technique

    NASA Astrophysics Data System (ADS)

    Ma, Shuang; Wen, Ming-Wu; Wang, Zhan-Shan

    2016-07-01

    The thermal stability and separation characteristics of anti-sticking layers of Pt/Cr films are studied in this paper. Several types of adhesion layers were investigated: 10.0 nm Pt, 1.5 nm Cr + 50.0 nm Pt, 2.5 nm Cr + 50.0 nm Pt and 3.5 nm Cr + 50.0 nm Pt fabricated using direct current magnetron sputtering. The variation of layer thickness, roughness, crystallization and surface topography of Pt/Cr films were analyzed by grazing incidence X-ray reflectometry, large angle X-ray diffraction and optical profiler before and after heating. 2.5 nm Cr + 50.0 nm Pt film exhibits the best thermal stability and separation characteristics according to the heating and hot slumping experiments. The film was also applied as an anti-sticking layer to optimize the maximum temperature of the hot slumping technique. Supported by CAS XTP project XDA04060605

  6. Optimization of the separation of lysergic acid diethylamide in urine by a sweeping technique using micellar electrokinetic chromatography.

    PubMed

    Fang, Ching; Liu, Ju-Tsung; Lin, Cheng-Huang

    2002-07-25

    The separation and on-line concentrations of lysergic acid diethylamide (LSD), iso-lysergic acid diethylamide (iso-LSD) and lysergic acid N,N-methylpropylamide (LAMPA) in human urine were investigated by capillary electrophoresis-fluorescence spectroscopy using sodium dodecyl sulfate (SDS) as an anionic surfactant. A number of parameters such as buffer pH, SDS concentration, Brij-30 concentration and the content of organic solvent used in separation, were optimized. The techniques of sweeping-micellar electrokinetic chromatography (sweeping-MEKC) and cation-selective exhaustive injection-sweep-micellar electrokinetic chromatography (CSEI-sweep-MEKC) were used for determining on-line concentrations. The advantages and disadvantages of this procedure with respect to sensitivity, precision and simplicity are discussed and compared.

  7. Cryptosporidium Oocyst Detection in Water Samples: Floatation Technique Enhanced with Immunofluorescence Is as Effective as Immunomagnetic Separation Method

    PubMed Central

    Koompapong, Khuanchai; Sutthikornchai, Chantira

    2009-01-01

    Cryptosporidium can cause gastrointestinal diseases worldwide, consequently posing public health problems and economic burden. Effective techniques for detecting contaminated oocysts in water are important to prevent and control the contamination. Immunomagnetic separation (IMS) method has been widely employed recently due to its efficiency, but, it is costly. Sucrose floatation technique is generally used for separating organisms by using their different specific gravity. It is effective and cheap but time consuming as well as requiring highly skilled personnel. Water turbidity and parasite load in water sample are additional factors affecting to the recovery rate of those 2 methods. We compared the efficiency of IMS and sucrose floatation methods to recover the spiked Cryptosporidium oocysts in various turbidity water samples. Cryptosporidium oocysts concentration at 1, 101, 102, and 103 per 10 µl were spiked into 3 sets of 10 ml-water turbidity (5, 50, and 500 NTU). The recovery rate of the 2 methods was not different. Oocyst load at the concentration < 102 per 10 ml yielded unreliable results. Water turbidity at 500 NTU decreased the recovery rate of both techniques. The combination of sucrose floatation and immunofluorescense assay techniques (SF-FA) showed higher recovery rate than IMS and immunofluorescense assay (IMS-FA). We used this SF-FA to detect Cryptosporidium and Giardia from the river water samples and found 9 and 19 out of 30 (30% and 63.3%) positive, respectively. Our results favored sucrose floatation technique enhanced with immunofluorescense assay for detecting contaminated protozoa in water samples in general laboratories and in the real practical setting. PMID:19967082

  8. Cryptosporidium oocyst detection in water samples: floatation technique enhanced with immunofluorescence is as effective as immunomagnetic separation method.

    PubMed

    Koompapong, Khuanchai; Sutthikornchai, Chantira; Sukthana, Yowalark

    2009-12-01

    Cryptosporidium can cause gastrointestinal diseases worldwide, consequently posing public health problems and economic burden. Effective techniques for detecting contaminated oocysts in water are important to prevent and control the contamination. Immunomagnetic separation (IMS) method has been widely employed recently due to its efficiency, but, it is costly. Sucrose floatation technique is generally used for separating organisms by using their different specific gravity. It is effective and cheap but time consuming as well as requiring highly skilled personnel. Water turbidity and parasite load in water sample are additional factors affecting to the recovery rate of those 2 methods. We compared the efficiency of IMS and sucrose floatation methods to recover the spiked Cryptosporidium oocysts in various turbidity water samples. Cryptosporidium oocysts concentration at 1, 10(1), 10(2), and 10(3) per 10 microl were spiked into 3 sets of 10 ml-water turbidity (5, 50, and 500 NTU). The recovery rate of the 2 methods was not different. Oocyst load at the concentration < 10(2) per 10 ml yielded unreliable results. Water turbidity at 500 NTU decreased the recovery rate of both techniques. The combination of sucrose floatation and immunofluorescense assay techniques (SF-FA) showed higher recovery rate than IMS and immunofluorescense assay (IMS-FA). We used this SF-FA to detect Cryptosporidium and Giardia from the river water samples and found 9 and 19 out of 30 (30% and 63.3%) positive, respectively. Our results favored sucrose floatation technique enhanced with immunofluorescense assay for detecting contaminated protozoa in water samples in general laboratories and in the real practical setting.

  9. Gas separation device based on electrical swing adsorption

    DOEpatents

    Judkins, Roddie R.; Burchell, Timothy D.

    1999-10-26

    A method and apparatus for separating one constituent, especially carbon dioxide, from a fluid mixture, such as natural gas. The fluid mixture flows through an adsorbent member having an affinity for molecules of the one constituent, the molecules being adsorbed on the adsorbent member. A voltage is applied to the adsorbent member, the voltage imparting a current flow which causes the molecules of the one constituent to be desorbed from the adsorbent member.

  10. New Developments in Membrane-Based Chemical Separations

    DTIC Science & Technology

    2007-11-02

    triacetate polymeric membrane with a crown ether incorporated as a carrier. They studied the properties and stability of these membranes for metal ion...authors is consistent with the thermodynamic stability of the crown ether with these ions as well as the trend in transport of these ions in other liquid...pyridine from quinine . Figure 4, shows the UV absorbance spectra of the feed and the permeate solutions in a molecular- separation experiment. Such

  11. Bacteriophage-based nanoprobes for rapid bacteria separation

    NASA Astrophysics Data System (ADS)

    Chen, Juhong; Duncan, Bradley; Wang, Ziyuan; Wang, Li-Sheng; Rotello, Vincent M.; Nugen, Sam R.

    2015-10-01

    The lack of practical methods for bacterial separation remains a hindrance for the low-cost and successful development of rapid detection methods from complex samples. Antibody-tagged magnetic particles are commonly used to pull analytes from a liquid sample. While this method is well-established, improvements in capture efficiencies would result in an increase of the overall detection assay performance. Bacteriophages represent a low-cost and more consistent biorecognition element as compared to antibodies. We have developed nanoscale bacteriophage-tagged magnetic probes, where T7 bacteriophages were bound to magnetic nanoparticles. The nanoprobe allowed the specific recognition and attachment to E. coli cells. The phage magnetic nanprobes were directly compared to antibody-conjugated magnetic nanoprobes. The capture efficiencies of bacteriophages and antibodies on nanoparticles for the separation of E. coli K12 at varying concentrations were determined. The results indicated a similar bacteria capture efficiency between the two nanoprobes.The lack of practical methods for bacterial separation remains a hindrance for the low-cost and successful development of rapid detection methods from complex samples. Antibody-tagged magnetic particles are commonly used to pull analytes from a liquid sample. While this method is well-established, improvements in capture efficiencies would result in an increase of the overall detection assay performance. Bacteriophages represent a low-cost and more consistent biorecognition element as compared to antibodies. We have developed nanoscale bacteriophage-tagged magnetic probes, where T7 bacteriophages were bound to magnetic nanoparticles. The nanoprobe allowed the specific recognition and attachment to E. coli cells. The phage magnetic nanprobes were directly compared to antibody-conjugated magnetic nanoprobes. The capture efficiencies of bacteriophages and antibodies on nanoparticles for the separation of E. coli K12 at varying

  12. Size based separation of micro-particles using adhesive ciliated surfaces: Mimicing the behaviour of suspension feeders

    NASA Astrophysics Data System (ADS)

    Tripathi, Anurag; Bhattacharya, Amitabh; Balazs, Anna

    2013-03-01

    Separation of different size micro-particles in microfluidic devices is important for many biomedical applications. Inspired by the selective intake of small food particles by marine suspension feeders, we propose a novel separation mechanism of micro-particles using active cilia arrays with adhesive tips. By means of Lattice Boltzmann simulations, we show that mixture of two different size particles with size ratio greater than or equal to two can be nearly completely separated by tuning adhesion strength and cilia stiffness. The proposed technique can be used even at low Reynolds number (Re << 1) where separation mechanisms based on inertial effects will be of little use. For a given cilia-particle interaction, the balance of hydrodynamic and adhesive forces favors capture of particles below a critical size, which can be predicted by a simple analytical model.

  13. Production of monozygotic twin calves using the blastomere separation technique and Well of the Well culture system.

    PubMed

    Tagawa, M; Matoba, S; Narita, M; Saito, N; Nagai, T; Imai, K

    2008-03-15

    The present study was conducted to establish a simple and efficient method of producing monozygotic twin calves using the blastomere separation technique. To produce monozygotic twin embryos from zona-free two- and eight-cell embryos, blastomeres were separated mechanically by pipetting to form two demi-embryos; each single blastomere from the two-cell embryo and tetra-blastomeres from the eight-cell embryo were cultured in vitro using the Well of the Well culture system (WOW). This culture system supported the successful arrangement of blastomeres, resulting in their subsequent aggregation to form a demi-embryo developing to the blastocyst stage without a zona pellucida. There was no significant difference in the development to the blastocyst stage between blastomeres separated from eight-cell (72.0%) and two-cell (62.0%) embryos. The production rates of the monozygotic pair blastocysts and transferable paired blastocysts for demi-embryos obtained from eight-cell embryos (64.0 and 45.0%, respectively) were higher than those for demi-embryos obtained from two-cell embryos (49.0 and 31.0%, P<0.05). The separated demi-embryos obtained from eight-cell embryos produced by IVM/IVF of oocytes collected by ovum pick-up (OPU) from elite cows and cultured in wells tended to have a higher pregnancy rate (78.9% vs. 57.1%) and similar monozygotic twinning rate (40.0% vs. 33.3%) compared with monozygotic twin blastocysts obtained by the conventional bisection of in vivo derived blastocysts. In conclusion, producing twins by separation of blastomeres in OPU-IVF embryos, followed by the WOW culture system, yielded viable monozygotic demi-embryos, resulting in high rates of pregnancy and twinning rates after embryo transfer.

  14. Synergistic Separation Behavior of Boron in Metallurgical Grade Silicon Using a Combined Slagging and Gas Blowing Refining Technique

    NASA Astrophysics Data System (ADS)

    Wu, Jijun; Zhou, Yeqiang; Ma, Wenhui; Xu, Min; Yang, Bin

    2017-02-01

    A combined slagging and gas blowing refining technique for boron removal from metallurgical grade silicon using the CaO-SiO2-CaCl2 slag and the mixed Ar-O2-H2O gas is investigated. The oxygen gas blowing in combination with water vapor shows a wonderful removal efficiency of boron compared with the single oxygen or the single water vapor blowing. It is analyzed from the thermodynamics that a synergistic separation behavior of boron is resulted from CaCl2 and O2. Boron is removed and reduced from 22 to 0.75 ppmw with a removal efficiency of 96.6 pct.

  15. Membrane gas separation. (Latest citations from the NTIS data base). Published Search

    SciTech Connect

    Not Available

    1992-08-01

    The bibliography contains citations concerning the research and development of gas separation and purification techniques involving the use of plastic and metal membranes. Among the topics included are isotope separation, osmotic techniques, reverse osmosis, and preparation of membranes for specific separation processes. The permeability of polymer membranes is discussed in terms of physical properties as well as molecular structure. The selectivity of polymeric films for a variety of gases is also included. (Contains a minimum of 168 citations and includes a subject term index and title list.)

  16. DCT-based cyber defense techniques

    NASA Astrophysics Data System (ADS)

    Amsalem, Yaron; Puzanov, Anton; Bedinerman, Anton; Kutcher, Maxim; Hadar, Ofer

    2015-09-01

    With the increasing popularity of video streaming services and multimedia sharing via social networks, there is a need to protect the multimedia from malicious use. An attacker may use steganography and watermarking techniques to embed malicious content, in order to attack the end user. Most of the attack algorithms are robust to basic image processing techniques such as filtering, compression, noise addition, etc. Hence, in this article two novel, real-time, defense techniques are proposed: Smart threshold and anomaly correction. Both techniques operate at the DCT domain, and are applicable for JPEG images and H.264 I-Frames. The defense performance was evaluated against a highly robust attack, and the perceptual quality degradation was measured by the well-known PSNR and SSIM quality assessment metrics. A set of defense techniques is suggested for improving the defense efficiency. For the most aggressive attack configuration, the combination of all the defense techniques results in 80% protection against cyber-attacks with PSNR of 25.74 db.

  17. Separation of rare oligodendrocyte progenitor cells from brain using a high-throughput multilayer thermoplastic-based microfluidic device.

    PubMed

    Didar, Tohid Fatanat; Li, Kebin; Veres, Teodor; Tabrizian, Maryam

    2013-07-01

    Despite the advances made in the field of regenerative medicine, the progress in cutting-edge technologies for separating target therapeutic cells are still at early stage of development. These cells are often rare, such as stem cells or progenitor cells that their overall properties should be maintained during the separation process for their subsequent application in regenerative medicine. This work, presents separation of oligodendrocyte progenitor cells (OPCs) from rat brain primary cultures using an integrated thermoplastic elastomeric (TPE)- based multilayer microfluidic device fabricated using hot-embossing technology. OPCs are frequently used in recovery, repair and regeneration of central nervous system after injuries. Indeed, their ability to differentiate in vitro into myelinating oligodendrocytes, are extremely important for myelin repair. OPCs form 5-10% of the glial cells population. The traditional macroscale techniques for OPCs separation require pre-processing of cells and/or multiple time consuming steps with low efficiency leading very often to alteration of their properties. The proposed methodology implies to separate OPCs based on their smaller size compared to other cells from the brain tissue mixture. Using aforementioned microfluidic chip embedded with a 5 μm membrane pore size and micropumping system, a separation efficiency more than 99% was achieved. This microchip was able to operate at flow rates up to 100 μl/min, capable of separating OPCs from a confluent 75 cm(2) cell culture flask in less than 10 min, which provides us with a high-throughput and highly efficient separation expected from any cell sorting techniques.

  18. Carbon nanotube-based separation columns for microchip electrochromatography.

    PubMed

    Mogensen, K B; Delacourt, B; Kutter, J P

    2015-01-01

    Fabrication of the stationary phase for microchip chromatography is most often done by packing of the individual separation channel after fabrication of the microfluidic chip, which is a very time-consuming and costly process (Kutter. J Chromatogr A 1221:72-82, 2012). Here, we describe in detail the fabrication and operation protocols for devices with microfabricated carbon nanotube stationary phases for reverse-phase chromatography. In this protocol, the lithographically defined stationary phase is fabricated in the channel before bonding of a lid, thereby circumventing the difficult packaging procedures used in more conventional protocols.

  19. Applying knowledge compilation techniques to model-based reasoning

    NASA Technical Reports Server (NTRS)

    Keller, Richard M.

    1991-01-01

    Researchers in the area of knowledge compilation are developing general purpose techniques for improving the efficiency of knowledge-based systems. In this article, an attempt is made to define knowledge compilation, to characterize several classes of knowledge compilation techniques, and to illustrate how some of these techniques can be applied to improve the performance of model-based reasoning systems.

  20. A comparative study of Sephadex, glass wool and Percoll separation techniques on sperm quality and IVF results for cryopreserved bovine semen.

    PubMed

    Lee, Hae-Lee; Kim, Sue-Hee; Ji, Dong-Beom; Kim, Yong-Jun

    2009-09-01

    The aim of this study was to compare the effects of spermatozoa separation techniques on sperm quality and in-vitro fertilization (IVF) results for cryopreserved bovine semen. Sephadex, glass wool and Percoll gradient separation techniques were used for sperm separation and sperm motility, morphology and membrane integrity were evaluated before and after separation. Also, cleavage and blastocyst developmental rate were investigated after IVF with sperm recovered by each separation technique. The motility of samples obtained by the three separation techniques were greater compared to the control samples (p < 0.05). The percentage of spermatozoa with intact plasma-membrane integrity, identified by 6-carboxyfluoresceindiacetate/ propidium iodide fluorescent staining and the hypo-osmotic swelling test, was highest in the glass wool filtration samples (p < 0.05). The cleavage and blastocyst rate of total oocytes produced from glass wool filtration samples were also higher than the control and Sephadex filtration samples (p < 0.05), but were not significantly different from Percoll separation samples. However, a significantly greater number of cleaved embryos produced by glass wool filtration developed to blastocyst stage than those produced by Percoll separation (p < 0.05). These results indicate that spermatozoa with good quality can be achieved by these three separation techniques and can be used for bovine IVF. In particular, it suggests that glass wool filtration would be the most effective method of the three for improving sperm quality and embryo production for cryopreserved bovine spermatozoa.

  1. Mechanically durable, superoleophobic coatings prepared by layer-by-layer technique for anti-smudge and oil-water separation

    PubMed Central

    Brown, Philip S.; Bhushan, Bharat

    2015-01-01

    Superoleophobic surfaces are of interest for anti-fouling, self-cleaning, anti-smudge, low-drag, anti-fog, and oil-water separation applications. Current bioinspired surfaces are of limited use due to a lack of mechanical durability. A so-called layer-by-layer approach, involving charged species with electrostatic interactions between layers, can provide the flexibility needed to improve adhesion to the substrate while providing a low surface tension coating at the air interface. In this work, a polyelectrolyte binder, SiO2 nanoparticles, and a fluorosurfactant are spray deposited separately to create a durable, superoleophobic coating. Polydiallyldimethylammonium chloride (PDDA) polyelectrolyte was complexed with a fluorosurfactant layer (FL), which provides oil repellency while being hydrophilic. This oleophobic/superhydrophilic behavior was enhanced through the use of roughening with SiO2 particles resulting in a superoleophobic coating with hexadecane contact angles exceeding 155° and tilt angles of less than 4°. The coating is also superhydrophilic, which is desirable for oil-water separation applications. The durability of these coatings was examined through the use of micro- and macrowear experiments. These coatings currently display characteristics of transparency. Fabrication of these coatings via the layer-by-layer technique results in superoleophobic surfaces displaying improved durability compared to existing work where either the durability or the oil-repellency is compromised. PMID:25731716

  2. Mechanically durable, superoleophobic coatings prepared by layer-by-layer technique for anti-smudge and oil-water separation

    NASA Astrophysics Data System (ADS)

    Brown, Philip S.; Bhushan, Bharat

    2015-03-01

    Superoleophobic surfaces are of interest for anti-fouling, self-cleaning, anti-smudge, low-drag, anti-fog, and oil-water separation applications. Current bioinspired surfaces are of limited use due to a lack of mechanical durability. A so-called layer-by-layer approach, involving charged species with electrostatic interactions between layers, can provide the flexibility needed to improve adhesion to the substrate while providing a low surface tension coating at the air interface. In this work, a polyelectrolyte binder, SiO2 nanoparticles, and a fluorosurfactant are spray deposited separately to create a durable, superoleophobic coating. Polydiallyldimethylammonium chloride (PDDA) polyelectrolyte was complexed with a fluorosurfactant layer (FL), which provides oil repellency while being hydrophilic. This oleophobic/superhydrophilic behavior was enhanced through the use of roughening with SiO2 particles resulting in a superoleophobic coating with hexadecane contact angles exceeding 155° and tilt angles of less than 4°. The coating is also superhydrophilic, which is desirable for oil-water separation applications. The durability of these coatings was examined through the use of micro- and macrowear experiments. These coatings currently display characteristics of transparency. Fabrication of these coatings via the layer-by-layer technique results in superoleophobic surfaces displaying improved durability compared to existing work where either the durability or the oil-repellency is compromised.

  3. Mechanically durable, superoleophobic coatings prepared by layer-by-layer technique for anti-smudge and oil-water separation.

    PubMed

    Brown, Philip S; Bhushan, Bharat

    2015-03-03

    Superoleophobic surfaces are of interest for anti-fouling, self-cleaning, anti-smudge, low-drag, anti-fog, and oil-water separation applications. Current bioinspired surfaces are of limited use due to a lack of mechanical durability. A so-called layer-by-layer approach, involving charged species with electrostatic interactions between layers, can provide the flexibility needed to improve adhesion to the substrate while providing a low surface tension coating at the air interface. In this work, a polyelectrolyte binder, SiO2 nanoparticles, and a fluorosurfactant are spray deposited separately to create a durable, superoleophobic coating. Polydiallyldimethylammonium chloride (PDDA) polyelectrolyte was complexed with a fluorosurfactant layer (FL), which provides oil repellency while being hydrophilic. This oleophobic/superhydrophilic behavior was enhanced through the use of roughening with SiO2 particles resulting in a superoleophobic coating with hexadecane contact angles exceeding 155° and tilt angles of less than 4°. The coating is also superhydrophilic, which is desirable for oil-water separation applications. The durability of these coatings was examined through the use of micro- and macrowear experiments. These coatings currently display characteristics of transparency. Fabrication of these coatings via the layer-by-layer technique results in superoleophobic surfaces displaying improved durability compared to existing work where either the durability or the oil-repellency is compromised.

  4. Hydrodynamic size-based separation and characterization of protein aggregates from total cell lysates

    PubMed Central

    Tanase, Maya; Zolla, Valerio; Clement, Cristina C; Borghi, Francesco; Urbanska, Aleksandra M; Rodriguez-Navarro, Jose Antonio; Roda, Barbara; Zattoni, Andrea; Reschiglian, Pierluigi; Cuervo, Ana Maria; Santambrogio, Laura

    2016-01-01

    Herein we describe a protocol that uses hollow-fiber flow field-flow fractionation (FFF) coupled with multiangle light scattering (MALS) for hydrodynamic size-based separation and characterization of complex protein aggregates. The fractionation method, which requires 1.5 h to run, was successfully modified from the analysis of protein aggregates, as found in simple protein mixtures, to complex aggregates, as found in total cell lysates. In contrast to other related methods (filter assay, analytical ultracentrifugation, gel electrophoresis and size-exclusion chromatography), hollow-fiber flow FFF coupled with MALS allows a flow-based fractionation of highly purified protein aggregates and simultaneous measurement of their molecular weight, r.m.s. radius and molecular conformation (e.g., round, rod-shaped, compact or relaxed). The polyethersulfone hollow fibers used, which have a 0.8-mm inner diameter, allow separation of as little as 20 μg of total cell lysates. In addition, the ability to run the samples in different denaturing and nondenaturing buffer allows defining true aggregates from artifacts, which can form during sample preparation. The protocol was set up using Paraquat-induced carbonylation, a model that induces protein aggregation in cultured cells. This technique will advance the biochemical, proteomic and biophysical characterization of molecular-weight aggregates associated with protein mutations, as found in many CNS degenerative diseases, or chronic oxidative stress, as found in aging, and chronic metabolic and inflammatory conditions. PMID:25521790

  5. An investigation of paper based microfluidic devices for size based separation and extraction applications.

    PubMed

    Zhong, Z W; Wu, R G; Wang, Z P; Tan, H L

    2015-09-01

    Conventional microfluidic devices are typically complex and expensive. The devices require the use of pneumatic control systems or highly precise pumps to control the flow in the devices. This work investigates an alternative method using paper based microfluidic devices to replace conventional microfluidic devices. Size based separation and extraction experiments conducted were able to separate free dye from a mixed protein and dye solution. Experimental results showed that pure fluorescein isothiocyanate could be separated from a solution of mixed fluorescein isothiocyanate and fluorescein isothiocyanate labeled bovine serum albumin. The analysis readings obtained from a spectrophotometer clearly show that the extracted tartrazine sample did not contain any amount of Blue-BSA, because its absorbance value was 0.000 measured at a wavelength of 590nm, which correlated to Blue-BSA. These demonstrate that paper based microfluidic devices, which are inexpensive and easy to implement, can potentially replace their conventional counterparts by the use of simple geometry designs and the capillary action. These findings will potentially help in future developments of paper based microfluidic devices.

  6. Silica/polyacrylonitrile hybrid nanofiber membrane separators via sol-gel and electrospinning techniques for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Yanilmaz, Meltem; Lu, Yao; Zhu, Jiadeng; Zhang, Xiangwu

    2016-05-01

    Silica/polyacrylonitrile (SiO2/PAN) hybrid nanofiber membranes were fabricated by using sol-gel and electrospinning techniques and their electrochemical performance was evaluated for use as separators in lithium-ion batteries. The aim of this study was to design high-performance separator membranes with enhanced electrochemical performance and good thermal stability compared to microporous polyolefin membranes. In this study, SiO2 nanoparticle content up to 27 wt% was achieved in the membranes by using sol-gel technique. It was found that SiO2/PAN hybrid nanofiber membranes had superior electrochemical performance with good thermal stability due to their high SiO2 content and large porosity. Compared with commercial microporous polyolefin membranes, SiO2/PAN hybrid nanofiber membranes had larger liquid electrolyte uptake, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. SiO2/PAN hybrid nanofiber membranes with different SiO2 contents (0, 16, 19 and 27 wt%) were also assembled into lithium/lithium iron phosphate cells, and high cell capacities and good cycling performance were demonstrated at room temperature. In addition, cells using SiO2/PAN hybrid nanofiber membranes with high SiO2 contents showed superior C-rate performance compared to those with low SiO2 contents and commercial microporous polyolefin membrane.

  7. Magnetic separation of iron-based nanosorbents from watery solutions

    NASA Astrophysics Data System (ADS)

    Medvedeva, Irina; Bakhteeva, Iuliia; Zhakov, Sergey; Baerner, Klaus

    2016-04-01

    Iron and iron oxide magnetic nanoparticles (MNP) both naked and with chemically modified surface are promising agents for different environmental applications, in particular for water purification and for analytical control of water and soil pollution. The MNP can be used as sorbents with selective abilities due to designed surface functionalization. While a lot of research has been devoted to the impurity sorption processes, the second part, that is the efficient removal of the MNP sorbents from the watery solution, has not been sufficiently studied so far. For that particles with magnetic cores are especially attractive due to the possibility of their subsequent magnetic separation from water without using coagulants, i.e. without a secondary water pollution, just by applying external magnetic fields B. In order to remove magnetic sorbent nanoparticles ( 10-100 nm) effectively from the water solution gradient magnetic fields are required. Depending on the MNP size, the magnetic moment, the chemical properties of the solution, the water purification conditions , either the low gradient magnetic separation (LGMS) with dB/dz < 100 T/m or the high gradient magnetic separation (HGMS) with dB/dz > 100 T/m is used. The gradient magnetic field is provided by permanent magnets or electromagnets of different configuration. In this work the sedimentation dynamics of naked Fe3O4 and Fe3O4@SiO2 nanoparticles (10-30 nm) in water was studied in a vertical gradient magnetic field (B1 ≤ 0.3T, dB/dz ≤ 0.13 T/cm). By this LGMS , the sedimentation time of the naked Fe3O4 NP is reduced down from several days to several minutes. The sedimentation time for Fe3O4@SiO2 decreases from several weeks to several hours and to several minutes when salts Na2SO4, CaCl2, NaH2PO4 are added to the solution. The results are interpreted in terms of MNP aggregate formation caused by electrostatic, steric and magnetic inter-particle interactions in the watery solution. ACKNOWLEDGMENTS The work was

  8. Gold nanomaterials based pseudostationary phases in capillary electrophoresis: a brand-new attempt at chondroitin sulfate isomers separation.

    PubMed

    Zhao, Ting; Zhou, Guanglian; Wu, Yuanhong; Liu, Xiumei; Wang, Fengshan

    2015-02-01

    In this work, a CE method with bare gold nanorods (GNRs) based pseudostationary phase was developed and applied for the separation of chondroitin sulfate (CS) isomers, CS, and dermatan sulfate (DS). The separation efficiency was investigated by varying the experimental parameters such as concentration and pH of the BGE, separation voltage, internal diameter of capillary, different size, and morphology of gold nanomaterials. Results showed that different size and morphology of gold nanomaterials had different effects on the separation of CS and DS. The best separation of CS and DS was achieved in the BGE composed of aqueous 150 mmol/L (mM) ethylenediamine + 20 mM sodium dihydrogen phosphate + 30% v/v GNRs, pH 4.5, at the separation voltage of -10 kV. Capillary was 59.2 cm in length (effective length 49 cm), 50 μm id capillary thermostated at 25°C. CE with bare GNRs used as pseudostationary phase was shown to be a suitable technique for the separation of CS and DS mixtures with wider peaks. RSD of migration time and peak area of CS and DS were 0.13, 0.14 and 0.86, 1.07%, respectively.

  9. Onsets, autocorrelation functions and spikes for direction-based sound source separation

    NASA Astrophysics Data System (ADS)

    Smith, Leslie S.; Fraser, Dagmar S.

    2005-04-01

    The aim of this work is separation of foreground speech from background sound sources using selective remixing of bandpass filtered channels. Clearly, the remixing parameters must be dynamic since the speech and noise spectra are highly non-stationary. Remixing parameters are recomputed at onsets, detected using biologically motivated techniques [L. S. Smith and D. S. Fraser, IEEE TNNS 15, 1125-1134 (2004)]. However, onsets may originate from the foreground or the background. To select appropriate onsets from the foreground source (whose direction is known) a two microphone system is used, selecting onsets for which the estimated direction in that channel corresponds to the foreground direction. Two different techniques for direction estimation are used: a channel by channel short-term autocorrelation technique, and a channel by channel spike based phase synchronous system (SBPSS), computing ITDs [L. S. Smith, in Artificial Neural Networks, Proc ICANN 2001, LNCS 2130, pp. 1103-1108 (Springer, 2001)] and IIDs [L. S. Smith, in From Animals to Animats, Vol. 7, pp. 60-61 (MIT Press, 2002)]. Results comparing the performance of autocorrelation and SBPSS on single source and source plus noise signals in an office environment are presented. [Work supported by UK EPSRC.

  10. Blind I/Q Signal Separation-Based Solutions for Receiver Signal Processing

    NASA Astrophysics Data System (ADS)

    Valkama, Mikko; Renfors, Markku; Koivunen, Visa

    2005-12-01

    This paper introduces some novel digital signal processing (DSP)-based approaches to some of the most fundamental tasks of radio receivers, namely, channel equalization, carrier synchronization, and I/Q mismatch compensation. The leading principle is to show that all these problems can be solved blindly (i.e., without training signals) by forcing the I and Q components of the observed data as independent as possible. Blind signal separation (BSS) is then introduced as an efficient tool to carry out these tasks, and simulation examples are used to illustrate the performance of the proposed approaches. The main application area of the presented carrier synchronization and I/Q mismatch compensation techniques is in direct-conversion type receivers, while the proposed channel equalization principles basically apply to any radio architecture.

  11. A Model of Turbulence, Sediment Transport and Morphodynamics of Lateral Separation Zones in Canyon Rivers using Detached Eddy Simulation Technique

    NASA Astrophysics Data System (ADS)

    Alvarez, L. V.; Schmeeckle, M. W.; Grams, P. E.; Moreno, H. A.

    2015-12-01

    Lateral separation zones are featured by large-scale flow separation, secondary recirculation zones and free shear layers. In the Colorado River, lateral separation zones are the principal source of fine sediment for eddy sandbars. A parallelized, three-dimensional turbulence-resolving model is coupled with a continuum sediment transport model and tested in lateral separation zones located in two pools along the Colorado River in Marble Canyon. The model aims to study the flow and sediment dynamics of lateral separation zones, recognizing the important role that these processes play in the erosion, deposition and morphodynamics of eddy sandbars. The Detached Eddy Simulation (DES) technique is employed for fully resolved turbulence at larger scales than the Sub-Grid-Scale (SGS) while SGS turbulence is modeled using the Spalart-Allmaras one equation turbulence closure model. This DES-3D flow model is coupled to a sediment advection-diffusion formulation, wherein advection is provided by the DES velocity field minus particles settling velocity, and diffusion is provided by the SGS. The Smith and McLean suspended sediment boundary condition is used to calculate the upward and downward settling of sediment fluxes in the near-bed grid cells. Five groups of sediment sizes are employed and estimated using a mixing layer model. Each fraction of the grain size group is redistributed every time step. Thus, the model is able to predict the exposure and burial of bedrock by fine grain size sediment. The simulated results show a pattern of unsteady pulsations in the exchange of concentration of sediment and deposition fluxes between the primary zone and the main channel. This exchange occurs at the convergence and divergence zones. These pulsations are more accentuated at the convergence zone, but still evidenced at the divergence zone. Along the simulated river-reach, the concentration values increase in the constrictions and decrease in the main channel. At both rapids, net

  12. Evolutionary multi-objective optimization based comparison of multi-column chromatographic separation processes for a ternary separation.

    PubMed

    Heinonen, Jari; Kukkonen, Saku; Sainio, Tuomo

    2014-09-05

    Performance characteristics of two advanced multi-column chromatographic separation processes with discontinuous feed, Multi-Column Recycling Chromatogrphy (MCRC) and Japan Organo (JO), were investigated for a ternary separation using multi-objective optimization with an evolutionary algorithm. Conventional batch process was used as a reference. Fractionation of a concentrated acid hydrolysate of wood biomass into sulfuric acid, monosaccharide, and acetic acid fractions was used as a model system. Comparison of the separation processes was based on selected performance parameters in their optimized states. Flow rates and step durations were taken as decision variables whereas the column configuration and dimensions were fixed. The MCRC process was found to be considerably more efficient than the other processes with respect to eluent consumption. The batch process gave the highest productivity and the JO process the lowest. Both of the multi-column processes gave significantly higher monosaccharide yield than the batch process. When eluent consumption and monosaccharide yield are taken into account together with productivity, the MCRC process was found to be the most efficient in the studied case.

  13. Lab-chip HPLC with integrated droplet-based microfluidics for separation and high frequency compartmentalisation.

    PubMed

    Kim, Jin-Young; Cho, Soong-Won; Kang, Dong-Ku; Edel, Joshua B; Chang, Soo-Ik; deMello, Andrew J; O'Hare, Danny

    2012-09-21

    We demonstrate the integration of a droplet-based microfluidic device with high performance liquid chromatography (HPLC) in a monolithic format. Sequential operations of separation, compartmentalisation and concentration counter were conducted on a monolithic chip. This describes the use of droplet-based microfluidics for the preservation of chromatographic separations, and its potential application as a high frequency fraction collector.

  14. Selective surface modification technique for improvement of chromatographic separation selectivity for sugar derivatives.

    PubMed

    Hosoya, Ken; Yoshizako, Kimihiro; Kubo, Takuya; Ikegami, Tohru; Tanaka, Nobuo; Haginaka, Jun

    2002-01-01

    Highly cross-linked macroporous polymers were prepared utilizing ethylene dimethacrylate as a cross-linking agent, in the presence or absence of methyl-alpha-D-glucoside as a kind of template molecule with methacrylic acid as a functional monomer. After the preparation of the polymers, we applied a high temperature to the cross-linked polymers to study the changes of adsorption properties of the polymers for sugar derivatives including the template molecule utilized. Interestingly, the heat treatment up to 250 degrees C afforded improvement of relative adsorption affinity for several sugar derivatives including the template molecule, while heat treatment up to 150 degrees C did not afford those improvements. The detailed studies including polymers prepared using acrylic acid as a functional monomer instead of methacrylic acid prove that temperatures higher than the Tg temperature of the polymer derived from a functional monomer such as methacrylic acid and higher than the melting point (mp) of the sugar template are necessary to afford the observed improvement of relative affinity based on the surface modification effects through the heat treatment to cross-linked polymers.

  15. Using Separable Nonnegative Matrix Factorization Techniques for the Analysis of Time-Resolved Raman Spectra.

    PubMed

    Luce, Robert; Hildebrandt, Peter; Kuhlmann, Uwe; Liesen, Jörg

    2016-09-01

    The key challenge of time-resolved Raman spectroscopy is the identification of the constituent species and the analysis of the kinetics of the underlying reaction network. In this work we present an integral approach that allows for determining both the component spectra and the rate constants simultaneously from a series of vibrational spectra. It is based on an algorithm for nonnegative matrix factorization that is applied to the experimental data set following a few pre-processing steps. As a prerequisite for physically unambiguous solutions, each component spectrum must include one vibrational band that does not significantly interfere with the vibrational bands of other species. The approach is applied to synthetic "experimental" spectra derived from model systems comprising a set of species with component spectra differing with respect to their degree of spectral interferences and signal-to-noise ratios. In each case, the species involved are connected via monomolecular reaction pathways. The potential and limitations of the approach for recovering the respective rate constants and component spectra are discussed.

  16. On Bitstream Based Edge Detection Techniques

    DTIC Science & Technology

    2009-01-01

    IEEE Transactions on, vol. 38, no. 1, pp. xviii– iv, Feb 1992. [5] Rafael C. Gonzalez and Richard E. Woods, Digital Image Processing, Addison-Wesley...Carmona-Poyato, R. Medina- Carnicer, and F. J. Madrid- Cuevas , “Automatic genera- tion of consensus ground truth for the comparison of edge detection techniques,” Image Vision Comput., vol. 26, no. 4, pp. 496–511, 2008.

  17. Sample injection and electrophoretic separation on a simple laminated paper based analytical device.

    PubMed

    Xu, Chunxiu; Zhong, Minghua; Cai, Longfei; Zheng, Qingyu; Zhang, Xiaojun

    2016-02-01

    We described a strategy to perform multistep operations on a simple laminated paper-based separation device by using electrokinetic flow to manipulate the fluids. A laminated crossed-channel paper-based separation device was fabricated by cutting a filter paper sheet followed by lamination. Multiple function units including sample loading, sample injection, and electrophoretic separation were integrated on a single paper based analytical device for the first time, by applying potential at different reservoirs for sample, sample waste, buffer, and buffer waste. As a proof-of-concept demonstration, mixed sample solution containing carmine and sunset yellow were loaded in the sampling channel, and then injected into separation channel followed by electrophoretic separation, by adjusting the potentials applied at the four terminals of sampling and separation channel. The effects of buffer pH, buffer concentration, channel width, and separation time on resolution of electrophoretic separation were studied. This strategy may be used to perform multistep operations such as reagent dilution, sample injection, mixing, reaction, and separation on a single microfluidic paper based analytical device, which is very attractive for building micro total analysis systems on microfluidic paper based analytical devices.

  18. Baseflow separation in a premontane transitional rainforest using stable isotope techniques

    NASA Astrophysics Data System (ADS)

    Miller, G. R.; DuMont, A.; Roark, E.; Cahill, A. T.; Brumbelow, J. K.

    2013-12-01

    Hydrologic, geologic, and biologic processes are critical to understanding the ecosystem in the tropical premontane transitional forests of Costa Rica. Precipitation is significantly lower during the dry season, and incoming rainfall can be completely intercepted and re-evaporated by the canopy during light events. These canopy processes can affect the rates of runoff and infiltration by changing the quantity and timing of rainfall reaching the ground surface. However, the resulting partitioning of stream water sources between event-water and baseflow from groundwater is not well quantified due to limited accessibility and complex subsurface conditions. This study focuses on research conducted at the Texas A&M Soltis Center for Education and Research, near San Ramón, Costa Rica. We have monitored a 2.2 ha watershed there, measuring precipitation and transpiration rates for over two years, and groundwater levels and stream flow rates for nearly one year. Precipitation rates for the watershed averaged 4.4 m/yr since 2010. Stream flow (runoff, spring flow, and baseflow) averaged 0.09 m^3/sec during the 2012-2013 wet seasons. At 1.2 mm/day, transpiration was a relatively minor component of the water budget. Over a 40-day span during summer 2013, we collected a combination of daily and rain-event based samples from locations throughout the watershed. Sources included: the main stream and two small tributaries, groundwater from piezometers, pore water from suction lysimeters, throughfall and stemflow from under canopy collection systems, and xylem water from 8 tree species across the watershed. We then measured stable isotope fractions (δ18O and δD) in the water using a Picarro L2120i CRDS. Isotope ratios for all surface water averaged -5.50‰ for δ18O and -28.00‰ for δD, while that measured under baseflow conditions were -5.45‰ for δ18O and -29.18‰ for δD. These results indicate that baseflow is the dominate source of stream water even in the wet season

  19. A search technique for planets in nearby binary stars using a ground-based interferometer

    NASA Astrophysics Data System (ADS)

    Traub, W. A.; Carleton, N. P.; Porro, I. L.

    1996-04-01

    A search for Jovian-type planets in 100 nearby binary stars could be carried out with the existing ground-based infrared-optical telescope array (IOTA) interferometer. We would study binaries with sufficiently great separation (25-50 AU; typical separation around 0.4 arcsec) that such a planet could be in a stable orbit about one member of the pair. The method is to measure the angular separation of stars in each binary, with a single-measurement accuracy sufficient to detect the amplitude of a Uranus orbiting one of the stars. The technique is based on an auxiliary device, the pupil-splitting interferometer (PSI), which substantially reduces systematic and random errors by converting a measurement of angular separation into a measurement of the differential optical delay between the two components of the binary. The program would be relatively economical, and could begin soon.

  20. Chemical shift-based water/fat separation in the presence of susceptibility-induced fat resonance shift

    PubMed Central

    Karampinos, Dimitrios C.; Yu, Huanzhou; Shimakawa, Ann; Link, Thomas M.; Majumdar, Sharmila

    2011-01-01

    Chemical shift-based water/fat separation methods have been emerging due to the growing clinical need for fat quantification in different body organs. Accurate quantification of proton-density fat fraction requires the assessment of many confounding factors, including the need of modeling the presence of multiple peaks in the fat spectrum. Most recent quantitative chemical shift-based water/fat separation approaches rely on a multi-peak fat spectrum with pre-calibrated peak locations and pre-calibrated or self-calibrated peak relative amplitudes. However, water/fat susceptibility differences can induce fat spectrum resonance shifts depending on the shape and orientation of the fatty inclusions. The effect is of particular interest in the skeletal muscle due to the anisotropic arrangement of extracellular lipids. In the present work, the effect of susceptibility-induced fat resonance shift on the fat fraction is characterized in a conventional complex-based chemical shift-based water/fat separation approach that does not model the susceptibility-induced fat resonance shift. A novel algorithm is then proposed in order to quantify the resonance shift in a complex-based chemical shift-based water/fat separation approach that considers the fat resonance shift in the signal model, aiming to extract information about the orientation/geometry of lipids. The technique is validated in a phantom and preliminary in vivo results are shown in the calf musculature of healthy and diabetic subjects. PMID:22247024

  1. Separation of thorium and uranium in nitric acid solution using silica based anion exchange resin.

    PubMed

    Chen, Yanliang; Wei, Yuezhou; He, Linfeng; Tang, Fangdong

    2016-09-30

    To separate thorium and uranium in nitric acid solution using anion exchange process, a strong base silica-based anion exchange resin (SiPyR-N4) was synthesized. Batch experiments were conducted and the separation factor of thorium and uranium in 9M nitric acid was about 10. Ion exchange chromatography was applied to separate thorium and uranium in different ratios. Uranium could be eluted by 9M nitric acid and thorium was eluted by 0.1M nitric acid. It was proved that thorium and uranium can be separated and recovered successfully by this method.

  2. WE-G-18C-07: Accelerated Water/fat Separation in MRI for Radiotherapy Planning Using Multi-Band Imaging Techniques

    SciTech Connect

    Crijns, S; Stemkens, B; Sbrizzi, A; Lagendijk, J; Berg, C van den; Andreychenko, A

    2014-06-15

    Purpose: Dixon sequences are used to characterize disease processes, obtain good fat or water separation in cases where fat suppression fails and to obtain pseudo-CT datasets. Dixon's method uses at least two images acquired with different echo times and thus requires prolonged acquisition times. To overcome associated problems (e.g., for DCE/cine-MRI), we propose to use a method for water/fat separation based on spectrally selective RF pulses. Methods: Two alternating RF pulses were used, that imposes a fat selective phase cycling over the phase encoding lines, which results in a spatial shift for fat in the reconstructed image, identical to that in CAIPIRINHA. Associated aliasing artefacts were resolved using the encoding power of a multi-element receiver array, analogous to SENSE. In vivo measurements were performed on a 1.5T clinical MR-scanner in a healthy volunteer's legs, using a four channel receiver coil. Gradient echo images were acquired with TE/TR = 2.3/4.7ms, flip angle 20°, FOV 45×22.5cm{sup 2}, matrix 480×216, slice thickness 5mm. Dixon images were acquired with TE,1/TE,2/TR=2.2/4.6/7ms. All image reconstructions were done in Matlab using the ReconFrame toolbox (Gyrotools, Zurich, CH). Results: RF pulse alternation yields a fat image offset from the water image. Hence the water and fat images fold over, which is resolved using in-plane SENSE reconstruction. Using the proposed technique, we achieved excellent water/fat separation comparable to Dixon images, while acquiring images at only one echo time. Conclusion: The proposed technique yields both inphase water and fat images at arbitrary echo times and requires only one measurement, thereby shortening the acquisition time by a factor 2. In future work the technique may be extended to a multi-band water/fat separation sequence that is able to achieve single point water/fat separation in multiple slices at once and hence yields higher speed-up factors.

  3. Paper-based device for separation and cultivation of single microalga.

    PubMed

    Chen, Chih-Chung; Liu, Yi-Ju; Yao, Da-Jeng

    2015-12-01

    Single-cell separation is among the most useful techniques in biochemical research, diagnosis and various industrial applications. Microalgae species have great economic importance as industrial raw materials. Microalgae species collected from environment are typically a mixed and heterogeneous population of species that must be isolated and purified for examination and further application. Conventional methods, such as serial dilution and a streaking-plate method, are intensive of labor and inefficient. We developed a paper-based device for separation and cultivation of single microalga. The fabrication was simply conducted with a common laser printer and required only a few minutes without lithographic instruments and clean-room. The driving force of the paper device was simple capillarity without a complicated pump connection that is part of most devices for microfluidics. The open-structure design of the paper device makes it operable with a common laboratory micropipette for sample transfer and manipulation with a naked eye or adaptable to a robotic system with functionality of high-throughput retrieval and analysis. The efficiency of isolating a single cell from mixed microalgae species is seven times as great as with a conventional method involving serial dilution. The paper device can serve also as an incubator for microalgae growth on simply rinsing the paper with a growth medium. Many applications such as highly expressed cell selection and various single-cell analysis would be applicable.

  4. PIE: A Dynamic Failure-Based Technique

    NASA Technical Reports Server (NTRS)

    Voas, Jeffrey M.

    1990-01-01

    This paper presents a dynamic technique for statistically estimating three program characteristics that affect a program's computational behavior: (1) the probability that a particular section of a program is executed, (2) the probability that the particular section affects the data state, and (3) the probability that a data state produced by that section has an effect on program output. These three characteristics can be used to predict whether faults are likely to be uncovered by software testing. Index Terms: Software testing, data state, fault, failure, testability. 1 Introduction

  5. Liquid Tunable Microlenses based on MEMS techniques

    PubMed Central

    Zeng, Xuefeng; Jiang, Hongrui

    2013-01-01

    The recent rapid development in microlens technology has provided many opportunities for miniaturized optical systems, and has found a wide range of applications. Of these microlenses, tunable-focus microlenses are of special interest as their focal lengths can be tuned using micro-scale actuators integrated with the lens structure. Realization of such tunable microlens generally relies on the microelectromechanical system (MEMS) technologies. Here, we review the recent progress in tunable liquid microlenses. The underlying physics relevant to these microlenses are first discussed, followed by description of three main categories of tunable microlenses involving MEMS techniques, mechanically driven, electrically driven, and those integrated within microfluidic systems. PMID:24163480

  6. Chip electrochromatographic systems: Novel vertically aligned carbon nanotube and silica monoliths based separations

    NASA Astrophysics Data System (ADS)

    Goswami, Shubhodeep

    2009-12-01

    Miniaturized chemical analysis systems, also know as 'lab-on-a-chip' devices have been rapidly developing over the last decade. Capillary electrochromatography (CEC), a multidimensional separation technique combining capillary electrophoresis (CE) and liquid chromatography (LC) has been of great interest for chip based applications. Preliminary work has been undertaken to develop vertically aligned carbon nanotubes and photopolymerizable silica solgel as novel stationary phase materials for 'chip CEC' separations. Patterned growth of CNTs in a specific location of the channel has been carried out using a solid phase Fe-Al catalyst as well as a vapor deposited ferrocene catalyst. Characterization of the CNT "forests" was achieved using optical microscopy, secondary electron microscopy, high resolution tunneling electron microscopy and Raman spectroscopy. Proof-of-concept applications were demonstrated using reversed phase CEC separations as well as solid phase extraction of a glycosylated protein using concanavilin A immobilized onto the CNT bed. Photopolymerizable silica solgel materials were developed as stationary phase for microfluidic electrochromatographic separations in disposable polydimethylsiloxane (PDMS) chip devices. Effect on morphology and pore size of gels were studied as function of UV and solgel polymerization conditions, porogen, salt additives, geometry and hydrolyzable methoxy-ies. Structural morphologies were studied with Secondary Electron Microscopy (SEM). Pore size and pore volumes were characterized by thermal porometry, nitrogen BET adsorptions and differential scanning calorimetry. Computational fluid dynamics and confocal microscopy tools were employed to study the transport of fluids and model analytes. These investigations were directed towards evolving improved strategies for rinsing of uncrosslinked monomers to form porous monoliths as well as to effect a desired separation under a set of electrochromatograhic conditions

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

    PubMed

    Pellegrino, John

    2003-03-01

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

  8. Towards mosquito sterile insect technique programmes: exploring genetic, molecular, mechanical and behavioural methods of sex separation in mosquitoes.

    PubMed

    Gilles, Jeremie R L; Schetelig, Marc F; Scolari, Francesca; Marec, František; Capurro, Margareth L; Franz, Gerald; Bourtzis, Kostas

    2014-04-01

    When considering a mosquito release programme, one of the first issues to be addressed is how to eliminate/separate the females. The greatest number of options might eventually be available for those who can use transgenic mosquitoes, but the inherent characteristics of the target species may also provide possibilities for interim measures until more efficient methods can be developed. Differences in intrinsic size, in behaviour and in development rate between females and males are often available and useful for sexing. Efficient species-specific systems for eliminating females at the embryo stage have been developed, but most have since been discarded due to lack of use. Ideal systems specifically kill female embryos using some treatment that can be manipulated during production. Such killing systems are far more efficient than using intrinsic sexual differences, but they systems require selectable genetic markers and sex-linkage created by rare random chromosomal rearrangements. While intrinsic sexual differences should not be considered as long-term candidates for the development of robust and efficient sexing approaches, in the absence of these, the accessibility and integration of less efficient systems can provide a stop-gap measure that allows rapid start up with a minimum of investment. The International Atomic Energy Agency is funding over a 5 year period (2013-2018) a new Coordinated Research Project on "Exploring Genetic, Molecular, Mechanical and Behavioural Methods of Sex Separation in Mosquitoes" to network researchers and to address the critical need of genetic sexing strains for the implementation of the sterile insect technique (using radiation-sterilised or transgenic male mosquitoes) and for insect incompatibility technique programmes against disease-transmitting mosquitoes.

  9. Apprenticeship Learning Techniques for Knowledge Based Systems

    DTIC Science & Technology

    1988-12-01

    domain, such as medicine. The Odysseus explanation-based learning program constructs explanations of problem-solving actions in the domain of medical...theories and empirical methods so as to allow construction of an explanation. The Odysseus learning program provides the first demonstration of using the... Odysseus explanation-based learning program is presfuted, which constructs explanations of human problem-solving actions in the domain of medical di

  10. Evaluation of strategies for size based separation of polydisperse vesicle suspensions

    NASA Astrophysics Data System (ADS)

    Storslett, Kari J.; Muller, Susan J.

    2016-11-01

    Microfluidic devices can be used to separate suspensions of deformable particles with different intrinsic characteristics (e.g. size) with reasonable throughputs and without external labeling. Using vesicle suspensions to test microfluidic separation schemes provides insight into cell separation. Two schemes for separating vesicle suspensions by size are discussed: filtration and inertial focusing. The filter physically prevents most large vesicles from passing through. The filtrate is collected at one outlet and the larger vesicles are collected at another. This device showed good size separation between the two collected suspensions and was able to reduce the polydispersity of the collected suspensions relative to the original suspension. The inertial separation device was based on a design studied by Di Carlo et al.. This design was modified for our suspension and showed an ability to separate the suspension by size; however, the separated suspension's polydispersity was only slightly reduced. The advantage of the inertial separation device was its greatly increased throughput. A separation strategy may be selected based on the relative importance of high throughput vs. reduced polydispersity.

  11. Aluminum oxyhydroxide based separator/electrolyte and battery system, and a method of making the same

    SciTech Connect

    Gerald, II; Rex E.; Klingler, Robert J.; Rathke, Jerome W.

    2011-02-15

    The instant invention relates a solid-state electrochemical cell and a novel separator/electrolyte incorporated therein. The invented electrochemical cell generally comprising: a unique metal oxyhydroxide based (i.e. AlOOH) separator/electrolyte membrane sandwiched between a first electrode and a second electrode. The novel separator/electrolyte comprises a nanoparticulate metal oxyhydroxide, preferably AlOOH and a salt which are mixed and then pressed together to form a monolithic metal oxyhydroxide-salt membrane.

  12. Conventional and Advanced Separations in Mass Spectrometry-Based Metabolomics: Methodologies and Applications

    SciTech Connect

    Heyman, Heino M.; Zhang, Xing; Tang, Keqi; Baker, Erin Shammel; Metz, Thomas O.

    2016-02-16

    Metabolomics is the quantitative analysis of all metabolites in a given sample. Due to the chemical complexity of the metabolome, optimal separations are required for comprehensive identification and quantification of sample constituents. This chapter provides an overview of both conventional and advanced separations methods in practice for reducing the complexity of metabolite extracts delivered to the mass spectrometer detector, and covers gas chromatography (GC), liquid chromatography (LC), capillary electrophoresis (CE), supercritical fluid chromatography (SFC) and ion mobility spectrometry (IMS) separation techniques coupled with mass spectrometry (MS) as both uni-dimensional and as multi-dimensional approaches.

  13. Trends and Techniques for Space Base Electronics

    NASA Technical Reports Server (NTRS)

    Trotter, J. D.; Wade, T. E.; Gassaway, J. D.

    1979-01-01

    Simulations of various phosphorus and boron diffusions in SOS were completed and a sputtering system, furnaces, and photolithography related equipment were set up. Double layer metal experiments initially utilized wet chemistry techniques. By incorporating ultrasonic etching of the vias, premetal cleaning a modified buffered HF, phosphorus doped vapox, and extended sintering, yields of 98% were obtained using the standard test pattern. A two dimensional modeling program was written for simulating short channel MOSFETs with nonuniform substrate doping. A key simplifying assumption used is that the majority carriers can be represented by a sheet charge at the silicon dioxide silicon interface. Although the program is incomplete, the two dimensional Poisson equation for the potential distribution was achieved. The status of other Z-D MOSFET simulation programs is summarized.

  14. Performance impact of dynamic surface coatings on polymeric insulator-based dielectrophoretic particle separators.

    PubMed

    Davalos, Rafael V; McGraw, Gregory J; Wallow, Thomas I; Morales, Alfredo M; Krafcik, Karen L; Fintschenko, Yolanda; Cummings, Eric B; Simmons, Blake A

    2008-02-01

    Efficient and robust particle separation and enrichment techniques are critical for a diverse range of lab-on-a-chip analytical devices including pathogen detection, sample preparation, high-throughput particle sorting, and biomedical diagnostics. Previously, using insulator-based dielectrophoresis (iDEP) in microfluidic glass devices, we demonstrated simultaneous particle separation and concentration of various biological organisms, polymer microbeads, and viruses. As an alternative to glass, we evaluate the performance of similar iDEP structures produced in polymer-based microfluidic devices. There are numerous processing and operational advantages that motivate our transition to polymers such as the availability of numerous innate chemical compositions for tailoring performance, mechanical robustness, economy of scale, and ease of thermoforming and mass manufacturing. The polymer chips we have evaluated are fabricated through an injection molding process of the commercially available cyclic olefin copolymer Zeonor 1060R. This publication is the first to demonstrate insulator-based dielectrophoretic biological particle differentiation in a polymeric device injection molded from a silicon master. The results demonstrate that the polymer devices achieve the same performance metrics as glass devices. We also demonstrate an effective means of enhancing performance of these microsystems in terms of system power demand through the use of a dynamic surface coating. We demonstrate that the commercially available nonionic block copolymer surfactant, Pluronic F127, has a strong interaction with the cyclic olefin copolymer at very low concentrations, positively impacting performance by decreasing the electric field necessary to achieve particle trapping by an order of magnitude. The presence of this dynamic surface coating, therefore, lowers the power required to operate such devices and minimizes Joule heating. The results of this study demonstrate that iDEP polymeric

  15. CANDU in-reactor quantitative visual-based inspection techniques

    NASA Astrophysics Data System (ADS)

    Rochefort, P. A.

    2009-02-01

    This paper describes two separate visual-based inspection procedures used at CANDU nuclear power generating stations. The techniques are quantitative in nature and are delivered and operated in highly radioactive environments with access that is restrictive, and in one case is submerged. Visual-based inspections at stations are typically qualitative in nature. For example a video system will be used to search for a missing component, inspect for a broken fixture, or locate areas of excessive corrosion in a pipe. In contrast, the methods described here are used to measure characteristic component dimensions that in one case ensure ongoing safe operation of the reactor and in the other support reactor refurbishment. CANDU reactors are Pressurized Heavy Water Reactors (PHWR). The reactor vessel is a horizontal cylindrical low-pressure calandria tank approximately 6 m in diameter and length, containing heavy water as a neutron moderator. Inside the calandria, 380 horizontal fuel channels (FC) are supported at each end by integral end-shields. Each FC holds 12 fuel bundles. The heavy water primary heat transport water flows through the FC pressure tube, removing the heat from the fuel bundles and delivering it to the steam generator. The general design of the reactor governs both the type of measurements that are required and the methods to perform the measurements. The first inspection procedure is a method to remotely measure the gap between FC and other in-core horizontal components. The technique involves delivering vertically a module with a high-radiation-resistant camera and lighting into the core of a shutdown but fuelled reactor. The measurement is done using a line-of-sight technique between the components. Compensation for image perspective and viewing elevation to the measurement is required. The second inspection procedure measures flaws within the reactor's end shield FC calandria tube rolled joint area. The FC calandria tube (the outer shell of the FC) is

  16. Accelerator based techniques for contraband detection

    NASA Astrophysics Data System (ADS)

    Vourvopoulos, George

    1994-05-01

    It has been shown that narcotics, explosives, and other contraband materials, contain various chemical elements such as H, C, N, O, P, S, and Cl in quantities and ratios that differentiate them from each other and from other innocuous substances. Neutrons and γ-rays have the ability to penetrate through various materials at large depths. They are thus able, in a non-intrusive way, to interrogate volumes ranging from suitcases to Sea-Land containers, and have the ability to image the object with an appreciable degree of reliability. Neutron induced reactions such as (n, γ), (n, n') (n, p) or proton induced γ-resonance absorption are some of the reactions currently investigated for the identification of the chemical elements mentioned above. Various DC and pulsed techniques are discussed and their advantages, characteristics, and current progress are shown. Areas where use of these methods is currently under evaluation are detection of hidden explosives, illicit drug interdiction, chemical war agents identification, nuclear waste assay, nuclear weapons destruction and others.

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

    PubMed

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

    2012-08-01

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

  18. 5 CFR 843.311 - Annuity based on death of a separated employee.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... beginning on the day after the death of the separated employee. (ii) The rate of the adjusted annuity equals... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Annuity based on death of a separated... SERVICE REGULATIONS (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-DEATH BENEFITS AND EMPLOYEE...

  19. A protein molecular weight map of ES2 clear cell ovarian carcinoma cells using a two-dimensional liquid separations/mass mapping technique.

    PubMed

    Wang, Haixing; Kachman, Maureen T; Schwartz, Donald R; Cho, Kathleen R; Lubman, David M

    2002-09-01

    A molecular weight map of the protein content of ES2 human clear cell ovarian carcinoma cells has been produced using a two-dimensional (2-D) liquid separations/mass mapping technique. This method uses a 2-D liquid separation of proteins from whole cell lysates coupled on-line to an electrospray ionization-time of flight (ESI-TOF) mass spectrometer to map the accurate intact molecular weight (M(r)) of the protein content of the cells. The two separation dimensions involve the use of liquid isoelectric focusing as the first phase and nonporous silica reversed-phase high-performance liquid chromatography (HPLC) as the second phase of separation. The detection by ESI-TOF-MS provides an image of pI versus M(r) analogous to 2-D gel electrophoresis. Each protein is then identified based upon matrix-assisted laser desorption/ionization (MALDI)-TOF-MS peptide mapping and intact M(r) so that a standard map is produced against which other ovarian carcinoma cell lines can be compared. The accurate intact M(r) together with the pI fraction, and peptide map serve to tag the protein for future interlysate comparisons. An internal standard is also used to provide a means for quantitation for future interlysate studies. In the ES2 cell line under study it is shown that nearly 900 M(r) bands are detected over 17 pI fractions from pH 4 to 12 and a M(r) range up to 85 kDa and that around 290 of these bands can be identified using mass spectrometric based techniques. The protein M(r) is detected within an accuracy of 150 ppm and it is shown that many of the proteins in this human cancer sample are modified compared to the database. The protein M(r) map may serve as a highly reproducible standard Web-based method for comparing proteins from related human cell lines.

  20. A Nanoscale, Liquid-Phase DNA Separation Device Based on Brownian Ratchets

    NASA Astrophysics Data System (ADS)

    Bader, Joel S.

    1998-03-01

    Realizing the goals of the Human Genome Project depends on the ability to perform size-based separations of DNA molecules. DNA analysis has traditionally required inconvenient gel-based electrophoretic separations. We describe a novel, micromachined, non-electrophoretic device suitable for lab-on-a-chip applications. The device is designed to transport DNA using an asymmetric, periodic potential to rectify Brownian motion. The separation occurs in a homogeneous liquid, avoiding the use of gels or other special media. Experimental results from a working prototype NanoNiagara device validate theoretical predictions of its ability to transport DNA molecules based on size.

  1. Depth-based signal separation with vertical line arrays in the deep ocean.

    PubMed

    McCargar, Reid; Zurk, Lisa M

    2013-04-01

    Deep vertical line arrays can exploit the reliable acoustic path (RAP), which provides low transmission loss (TL) for targets at moderate ranges, and increased TL for distant interferers. However, nearby surface interference also has favorable RAP propagation and cannot be separated from a submerged target without horizontal aperture. In this work, a physics-based Fourier transform variant is introduced, which achieves depth-based signal separation by exploiting the spatial structure resulting from the coherent addition of the direct and surface-reflected propagation paths present for submerged sources. Simulation results demonstrate depth-based signal separation without requiring knowledge of the ocean environment.

  2. Shape-based Particle Separation via Elasto-Inertia Pinched Flow Fractionation (eiPFF)

    NASA Astrophysics Data System (ADS)

    Lu, Xinyu; Xuan, Xiangchun

    2015-11-01

    We report in this talk a continuous-flow shape-based separation of spherical and peanut-shaped rigid particles of equal volume via elasto-inertial pinched flow fractionation (eiPFF). This separation exploits the shape-dependence of the cross-stream particle migration induced by the elaso-inertial lift force in viscoelastic fluids. The parametric effects on this separation are systematically investigated in terms of dimensionless numbers. It is found that this separation is strongly affected by the Reynolds number, Weissenberg number and channel aspect ratio. Interestingly, the elasto-inertial deflection of peanut particles can be either greater or smaller than that of spherical particles.

  3. 38 CFR 21.7045 - Eligibility based on involuntary separation, voluntary separation, or participation in the Post...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... involuntary separation, voluntary separation, or participation in the Post-Vietnam Era Veterans' Educational..., voluntary separation, or participation in the Post-Vietnam Era Veterans' Educational Assistance Program. An.... (Authority: 38 U.S.C. 3018B) (d) Alternate eligibility requirements for participants in the Post-Vietnam...

  4. 38 CFR 21.7045 - Eligibility based on involuntary separation, voluntary separation, or participation in the Post...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... involuntary separation, voluntary separation, or participation in the Post-Vietnam Era Veterans' Educational..., voluntary separation, or participation in the Post-Vietnam Era Veterans' Educational Assistance Program. An.... (Authority: 38 U.S.C. 3018B) (d) Alternate eligibility requirements for participants in the Post-Vietnam...

  5. 38 CFR 21.7045 - Eligibility based on involuntary separation, voluntary separation, or participation in the Post...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... involuntary separation, voluntary separation, or participation in the Post-Vietnam Era Veterans' Educational..., voluntary separation, or participation in the Post-Vietnam Era Veterans' Educational Assistance Program. An.... (Authority: 38 U.S.C. 3018B) (d) Alternate eligibility requirements for participants in the Post-Vietnam...

  6. 38 CFR 21.7045 - Eligibility based on involuntary separation, voluntary separation, or participation in the Post...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... involuntary separation, voluntary separation, or participation in the Post-Vietnam Era Veterans' Educational..., voluntary separation, or participation in the Post-Vietnam Era Veterans' Educational Assistance Program. An.... (Authority: 38 U.S.C. 3018B) (d) Alternate eligibility requirements for participants in the Post-Vietnam...

  7. Sound field separating on arbitrary surfaces enclosing a sound scatterer based on combined integral equations.

    PubMed

    Fan, Zongwei; Mei, Deqing; Yang, Keji; Chen, Zichen

    2014-12-01

    To eliminate the limitations of the conventional sound field separation methods which are only applicable to regular surfaces, a sound field separation method based on combined integral equations is proposed to separate sound fields directly in the spatial domain. In virtue of the Helmholtz integral equations for the incident and scattering fields outside a sound scatterer, combined integral equations are derived for sound field separation, which build the quantitative relationship between the sound fields on two arbitrary separation surfaces enclosing the sound scatterer. Through boundary element discretization of the two surfaces, corresponding systems of linear equations are obtained for practical application. Numerical simulations are performed for sound field separation on different shaped surfaces. The influences induced by the aspect ratio of the separation surfaces and the signal noise in the measurement data are also investigated. The separated incident and scattering sound fields agree well with the original corresponding fields described by analytical expressions, which validates the effectiveness and accuracy of the combined integral equations based separation method.

  8. Novel Nanofiber-based Membrane Separators for Lithium-Ion Batteries

    NASA Astrophysics Data System (ADS)

    Yanilmaz, Meltem

    Lithium-ion batteries have been widely used in electronic devices including mobile phones, laptop computers, and cameras due to their high specific energy, high energy density, long cycling lifetime, and low self-discharge rate. Nowadays, lithium-ion batteries are finding new applications in electric/hybrid vehicles and energy storage for smart grids. To be used in these new applications, novel battery components are needed so that lithiumion batteries with higher cell performance, better safety, and lower cost can be developed. A separator is an important component to obtain safe batteries and its primary function is to prevent electronic contact between electrodes while regulating cell kinetics and ionic flow. Currently, microporous membranes are the most commonly used separator type and they have good mechanical properties and chemical stability. However, their wettability and thermal stabilities are not sufficient for applications that require high operating temperature and high performance. Due to the superior properties such as large specific surface area, small pore size and high porosity, electrospun nanofiber membranes can be good separator candidate for highperformance lithium-ion batteries. In this work, we focus our research on fabricating nanofiber-based membranes to design new high-performance separators with good thermal stability, as well as superior electrochemical performance compared to microporous polyolefin membranes. To combine the good mechanical strength of PP nonwovens with the excellent electrochemical properties of SiO2/polyvinylidene fluoride (PVDF) composite nanofibers, SiO 2/PVDF composite nanofiber-coated PP nonwoven membranes were prepared. It was found that the addition of SiO2 nanoparticles played an important role in improving the overall performance of these nanofiber-coated nonwoven membranes. Although ceramic/polymer composites can be prepared by encapsulating ceramic particles directly into polymer nanofibers, the performance

  9. Lipid-Based Immuno-Magnetic Separation of Archaea from a Mixed Community

    NASA Astrophysics Data System (ADS)

    Frickle, C. M.; Bailey, J.; Lloyd, K. G.; Shumaker, A.; Flood, B.

    2014-12-01

    Despite advancing techniques in microbiology, an estimated 98% of all microbial species on Earth have yet to be isolated in pure culture. Natural samples, once transferred to the lab, are commonly overgrown by "weed" species whose metabolic advantages enable them to monopolize available resources. Developing new methods for the isolation of thus-far uncultivable microorganisms would allow us to better understand their ecology, physiology and genetic potential. Physically separating target organisms from a mixed community is one approach that may allow enrichment and growth of the desired strain. Here we report on a novel method that uses known physiological variations between taxa, in this case membrane lipids, to segregate the desired organisms while keeping them alive and viable for reproduction. Magnetic antibodies bound to the molecule squalene, which is found in the cell membranes of certain archaea, but not bacteria, enable separation of archaea from bacteria in mixed samples. Viability of cells was tested by growing the separated fractions in batch culture. Efficacy and optimization of the antibody separation technique are being evaluated using qPCR and cell counts. Future work will apply this new separation technique to natural samples.

  10. An incentive-based source separation model for sustainable municipal solid waste management in China.

    PubMed

    Xu, Wanying; Zhou, Chuanbin; Lan, Yajun; Jin, Jiasheng; Cao, Aixin

    2015-05-01

    Municipal solid waste (MSW) management (MSWM) is most important and challenging in large urban communities. Sound community-based waste management systems normally include waste reduction and material recycling elements, often entailing the separation of recyclable materials by the residents. To increase the efficiency of source separation and recycling, an incentive-based source separation model was designed and this model was tested in 76 households in Guiyang, a city of almost three million people in southwest China. This model embraced the concepts of rewarding households for sorting organic waste, government funds for waste reduction, and introducing small recycling enterprises for promoting source separation. Results show that after one year of operation, the waste reduction rate was 87.3%, and the comprehensive net benefit under the incentive-based source separation model increased by 18.3 CNY tonne(-1) (2.4 Euros tonne(-1)), compared to that under the normal model. The stakeholder analysis (SA) shows that the centralized MSW disposal enterprises had minimum interest and may oppose the start-up of a new recycling system, while small recycling enterprises had a primary interest in promoting the incentive-based source separation model, but they had the least ability to make any change to the current recycling system. The strategies for promoting this incentive-based source separation model are also discussed in this study.

  11. FDI and Accommodation Using NN Based Techniques

    NASA Astrophysics Data System (ADS)

    Garcia, Ramon Ferreiro; de Miguel Catoira, Alberto; Sanz, Beatriz Ferreiro

    Massive application of dynamic backpropagation neural networks is used on closed loop control FDI (fault detection and isolation) tasks. The process dynamics is mapped by means of a trained backpropagation NN to be applied on residual generation. Process supervision is then applied to discriminate faults on process sensors, and process plant parameters. A rule based expert system is used to implement the decision making task and the corresponding solution in terms of faults accommodation and/or reconfiguration. Results show an efficient and robust FDI system which could be used as the core of an SCADA or alternatively as a complement supervision tool operating in parallel with the SCADA when applied on a heat exchanger.

  12. A robust physiology-based source separation method for QRS detection in low amplitude fetal ECG recordings.

    PubMed

    Vullings, R; Peters, C H L; Hermans, M J M; Wijn, P F F; Oei, S G; Bergmans, J W M

    2010-07-01

    The use of the non-invasively obtained fetal electrocardiogram (ECG) in fetal monitoring is complicated by the low signal-to-noise ratio (SNR) of ECG signals. Even after removal of the predominant interference (i.e. the maternal ECG), the SNR is generally too low for medical diagnostics, and hence additional signal processing is still required. To this end, several methods for exploiting the spatial correlation of multi-channel fetal ECG recordings from the maternal abdomen have been proposed in the literature, of which principal component analysis (PCA) and independent component analysis (ICA) are the most prominent. Both PCA and ICA, however, suffer from the drawback that they are blind source separation (BSS) techniques and as such suboptimum in that they do not consider a priori knowledge on the abdominal electrode configuration and fetal heart activity. In this paper we propose a source separation technique that is based on the physiology of the fetal heart and on the knowledge of the electrode configuration. This technique operates by calculating the spatial fetal vectorcardiogram (VCG) and approximating the VCG for several overlayed heartbeats by an ellipse. By subsequently projecting the VCG onto the long axis of this ellipse, a source signal of the fetal ECG can be obtained. To evaluate the developed technique, its performance is compared to that of both PCA and ICA and to that of augmented versions of these techniques (aPCA and aICA; PCA and ICA applied on preprocessed signals) in generating a fetal ECG source signal with enhanced SNR that can be used to detect fetal QRS complexes. The evaluation shows that the developed source separation technique performs slightly better than aPCA and aICA and outperforms PCA and ICA and has the main advantage that, with respect to aPCA/PCA and aICA/ICA, it performs more robustly. This advantage renders it favorable for employment in automated, real-time fetal monitoring applications.

  13. Fabrication of zirconia composite membrane by in-situ hydrothermal technique and its application in separation of methyl orange.

    PubMed

    Kumar, R Vinoth; Ghoshal, Aloke Kumar; Pugazhenthi, G

    2015-11-01

    The main objective of the work was preparation of zirconia membrane on a low cost ceramic support through an in-situ hydrothermal crystallization technique for the separation of methyl orange dye. To formulate the zirconia film on the ceramic support, hydrothermal reaction mixture was prepared using zirconium oxychloride as a zirconia source and ammonia as a precursor. The synthesized zirconia powder was characterized by X-ray diffractometer (XRD), N2 adsorption/desorption isotherms, Thermogravimetric analysis (TGA), Fourier transform infrared analysis (FTIR), Energy-dispersive X-ray (EDX) analysis and particle size distribution (PSD) to identify the phases and crystallinity, specific surface area, pore volume and pore size distribution, thermal behavior, chemical composition and size of the particles. The porosity, morphological structure and pure water permeability of the prepared zirconia membrane, as well as ceramic support were investigated using the Archimedes' method, Field emission scanning electron microscopy (FESEM) and permeability. The specific surface area, pore volume, pore size distribution of the zirconia powder was found to be 126.58m(2)/g, 3.54nm and 0.3-10µm, respectively. The porosity, average pore size and pure water permeability of the zirconia membrane was estimated to be 42%, 0.66µm and 1.44×10(-6)m(3)/m(2)skPa, respectively. Lastly, the potential of the membrane was investigated with separation of methyl orange by means of flux and rejection as a function of operating pressure and feed concentration. The rejection was found to decrease with increasing the operating pressure and increases with increasing feed concentrations. Moreover, it showed a high ability to reject methyl orange from aqueous solution with a rejection of 61% and a high permeation flux of 2.28×10(-5)m(3)/m(2)s at operating pressure of 68kPa.

  14. A Belief-Based Model of Air Traffic Controllers Performing Separation Assurance

    NASA Technical Reports Server (NTRS)

    Landry, S.J.

    2009-01-01

    A model of an air traffic controller performing a separation assurance task was produced. The model was designed to be simple to use and deploy in a simulator, but still provide realistic behavior. The model is based upon an evaluation of the safety function of the controller for separation assurance, and utilizes fast and frugal heuristics and belief networks to establish a knowledge set for the controller model. Based on this knowledge set, the controller acts to keep aircraft separated. Validation results are provided to demonstrate the model s performance.

  15. Recent advances in enrichment and separation strategies for mass spectrometry-based phosphoproteomics

    PubMed Central

    Yang, Chenxi; Zhong, Xuefei; Li, Lingjun

    2016-01-01

    Due to the significance of protein phosphorylation in various biological processes and signaling events, new analytical techniques for enhanced phosphoproteomics have been rapidly introduced in recent years. The combinatorial use of the phospho-specific enrichment techniques and prefractionation methods prior to MS analysis enables comprehensive profiling of the phosphoproteome and facilitates deciphering the critical roles that phosphorylation plays in signaling pathways in various biological systems. This review places special emphasis on the recent five-year (2009–2013) advances for enrichment and separation techniques that have been utilized for phosphopeptides prior to MS analysis. PMID:24687451

  16. Conductivity of carbonate- and perfluoropolyether-based electrolytes in porous separators

    NASA Astrophysics Data System (ADS)

    Devaux, Didier; Chang, Yu H.; Villaluenga, Irune; Chen, X. Chelsea; Chintapalli, Mahati; DeSimone, Joseph M.; Balsara, Nitash P.

    2016-08-01

    In lithium batteries, a porous separator filled with an electrolyte is placed in between the electrodes. Properties of the separator such as porosity and wettability strongly influence the conductivity of the electrolyte-separator composite. This study focuses on three commercial separators: a single layer polypropylene (Celgard 2500), a trilayer polypropylene-polyethylene-polypropylene (PP-PE-PP), and a porous polytetrafluoroethylene (PTFE). Electron microscopy was used to characterize the pore structure, and these experiments reveal large differences in pore morphology. The separators were soaked in both carbonate- and perfluoropolyether-based electrolytes. The conductivity of the neat electrolytes (σ0) varied from 6.46 × 10-6 to 1.76 × 10-2 S cm-1. The porosity and wettability of the separator affect the electrolyte uptake that in turn affect the conductivity of electrolyte-separator composites. The conductivity of the electrolyte-separator composites (σ) was found to follow a master equation, σ = 0.51·σ0·ϕc3.2±0.2, where ϕc is the volume fraction of the electrolyte in each separator.

  17. Microfluidic system for dielectrophoretic separation based on a trapezoidal electrode array.

    PubMed

    Choi, Sungyoung; Park, Je-Kyun

    2005-10-01

    This paper presents a novel microfluidic device for dielectrophoretic separation based on a trapezoidal electrode array (TEA). In this method, particles with different dielectric properties are separated by the device composed of the TEA for the dielectrophoretic deflection of particles under negative dielectrophoresis (DEP) and poly(dimethylsiloxane)(PDMS) microfluidic channel with a sinuous and expanded region. Polystyrene microparticles are exposed to an electric field generated from the TEA in the microfluidic channel and are dielectrophoretically focused to make all of them line up to one sidewall. When these particles arrive at the region of another TEA for dielectrophoretic separation, they are separated having different positions along the perpendicular direction to the fluid flow due to their different dielectrophoretic velocities. To evaluate the separation process and performance, both the effect of the flow rate on dielectrophoretic focusing and the influence of the number of trapezoidal electrodes on dielectrophoretic separation are investigated. Now that this method utilizes the TEA as a source of negative DEP, non-specific particle adhering to the electrode surface can be prevented; conventional separation approaches depending on the positive DEP force suffer from this problem. In addition, since various particle types are continuously separated, this method can be easily applicable to the separation and analysis of various dielectric particles with high particle recovery and selectivity.

  18. Suspended nanoparticles in surfactant media as a microextraction technique for simultaneous separation and preconcentration of cobalt, nickel and copper ions for electrothermal atomic absorption spectrometry determination.

    PubMed

    Dadfarnia, Shayessteh; Shakerian, Farid; Shabani, Ali Mohammad Haji

    2013-03-15

    The aim of this study was to describe a new method of microextraction based on the suspension of alumina nanoparticles in the surfactant media for simultaneous separation and preconcentration of the ultra-traces of cobalt, nickel and copper ions. In this technique, the alumina nanoparticles were suspended in the non-ionic surfactant solution of Triton X-114. The analytes in the sample solution were adsorbed onto the nanoparticles. After the phase separation based on the cloud point of the mixture at 40 °C, the nanoparticles settled down in the surfactant rich phase. Then 120 μL of nitric acid (3.0 mol L(-1)) was added to the surfactant rich phase which caused desorption of the analytes. Finally, the liquid phase was separated by centrifugation from the nanoparticles and was used for the quantification of the analytes by the electrothermal atomic absorption spectrometry (ETAAS). The parameters affecting the extraction and detection processes were optimized. Under the optimized experimental conditions (i.e. pH∼8, Triton X-114, 0.05% (v/v); temperature 40 °C), a sample volume of 25 mL resulted in the enhancement factors of 198, 205 and 206 and detection limits (defined as 3Sb/m) of 2.5, 2.8 and 2.6 ng L(-1) for Co(II), Ni(II) and Cu(II) respectively. The sorbent showed high capacity for these metal ions (30-40 mg g(-1) sorbent). The method was successfully applied to the determination of the analytes in natural water samples.

  19. Comparison of background ozone estimates over the western United States based on two separate model methodologies

    NASA Astrophysics Data System (ADS)

    Dolwick, Pat; Akhtar, Farhan; Baker, Kirk R.; Possiel, Norm; Simon, Heather; Tonnesen, Gail

    2015-05-01

    Two separate air quality model methodologies for estimating background ozone levels over the western U.S. are compared in this analysis. The first approach is a direct sensitivity modeling approach that considers the ozone levels that would remain after certain emissions are entirely removed (i.e., zero-out modeling). The second approach is based on an instrumented air quality model which tracks the formation of ozone within the simulation and assigns the source of that ozone to pre-identified categories (i.e., source apportionment modeling). This analysis focuses on a definition of background referred to as U.S. background (USB) which is designed to represent the influence of all sources other than U.S. anthropogenic emissions. Two separate modeling simulations were completed for an April-October 2007 period, both focused on isolating the influence of sources other than domestic manmade emissions. The zero-out modeling was conducted with the Community Multiscale Air Quality (CMAQ) model and the source apportionment modeling was completed with the Comprehensive Air Quality Model with Extensions (CAMx). Our analysis shows that the zero-out and source apportionment techniques provide relatively similar estimates of the magnitude of seasonal mean daily 8-h maximum U.S. background ozone at locations in the western U.S. when base case model ozone biases are considered. The largest differences between the two sets of USB estimates occur in urban areas where interactions with local NOx emissions can be important, especially when ozone levels are relatively low. Both methodologies conclude that seasonal mean daily 8-h maximum U.S. background ozone levels can be as high as 40-45 ppb over rural portions of the western U.S. Background fractions tend to decrease as modeled total ozone concentrations increase, with typical fractions of 75-100 percent on the lowest ozone days (<25 ppb) and typical fractions between 30 and 50% on days with ozone above 75 ppb. The finding that

  20. An efficient technique for nuclei segmentation based on ellipse descriptor analysis and improved seed detection algorithm.

    PubMed

    Xu, Hongming; Lu, Cheng; Mandal, Mrinal

    2014-09-01

    In this paper, we propose an efficient method for segmenting cell nuclei in the skin histopathological images. The proposed technique consists of four modules. First, it separates the nuclei regions from the background with an adaptive threshold technique. Next, an elliptical descriptor is used to detect the isolated nuclei with elliptical shapes. This descriptor classifies the nuclei regions based on two ellipticity parameters. Nuclei clumps and nuclei with irregular shapes are then localized by an improved seed detection technique based on voting in the eroded nuclei regions. Finally, undivided nuclei regions are segmented by a marked watershed algorithm. Experimental results on 114 different image patches indicate that the proposed technique provides a superior performance in nuclei detection and segmentation.

  1. Deformability based cell margination--a simple microfluidic design for malaria-infected erythrocyte separation.

    PubMed

    Hou, Han Wei; Bhagat, Ali Asgar S; Chong, Alvin Guo Lin; Mao, Pan; Tan, Kevin Shyong Wei; Han, Jongyoon; Lim, Chwee Teck

    2010-10-07

    In blood vessels with luminal diameter less than 300 µm, red blood cells (RBCs) which are smaller in size and more deformable than leukocytes, migrate to the axial centre of the vessel due to flow velocity gradient within the vessels. This phenomenon displaces the leukocytes to the vessel wall and is aptly termed as margination. Here, we demonstrate using microfluidics that stiffer malaria-infected RBCs (iRBCs) behave similar to leukocytes and undergo margination towards the sidewalls. This provides better understanding of the hemodynamic effects of iRBCs in microcirculation and its contribution to pathophysiological outcome relating to cytoadherence to endothelium. In this work, cell margination is mimicked for the separation of iRBCs from whole blood based on their reduced deformability. The malaria infected sample was tested in a simple long straight channel microfluidic device fabricated in polydimethylsiloxane. In this microchannel, cell margination was directed along the channel width with the iRBCs aligning near each sidewall and then subsequently removed using a 3-outlet system, thus achieving separation. Tests were conducted using ring stage and late trophozoite/schizont stage iRBCs. Device performance was quantified by analyzing the distribution of these iRBCs across the microchannel width at the outlet and also conducting flow cytometry analysis. Results indicate recovery of approximately 75% for early stage iRBCs and >90% for late stage iRBCs at the side outlets. The simple and passive system operation makes this technique ideal for on-site iRBCs enrichment in resource-limited settings, and can be applied to other blood cell diseases, e.g. sickle cell anemia and leukemia, characterized by changes in cell stiffness.

  2. A Word-Based Compression Technique for Text Files.

    ERIC Educational Resources Information Center

    Vernor, Russel L., III; Weiss, Stephen F.

    1978-01-01

    Presents a word-based technique for storing natural language text in compact form. The compressed text consists of a dictionary and a text that is a combination of actual running text and pointers to the dictionary. This technique has shown itself to be effective for both text storage and retrieval. (VT)

  3. There's plenty of gloom at the bottom: the many challenges of accurate quantitation in size-based oligomeric separations.

    PubMed

    Striegel, André M

    2013-11-01

    There is a variety of small-molecule species (e.g., tackifiers, plasticizers, oligosaccharides) the size-based characterization of which is of considerable scientific and industrial importance. Likewise, quantitation of the amount of oligomers in a polymer sample is crucial for the import and export of substances into the USA and European Union (EU). While the characterization of ultra-high molar mass macromolecules by size-based separation techniques is generally considered a challenge, it is this author's contention that a greater challenge is encountered when trying to perform, for quantitation purposes, separations in and of the oligomeric region. The latter thesis is expounded herein, by detailing the various obstacles encountered en route to accurate, quantitative oligomeric separations by entropically dominated techniques such as size-exclusion chromatography, hydrodynamic chromatography, and asymmetric flow field-flow fractionation, as well as by methods which are, principally, enthalpically driven such as liquid adsorption and temperature gradient interaction chromatography. These obstacles include, among others, the diminished sensitivity of static light scattering (SLS) detection at low molar masses, the non-constancy of the response of SLS and of commonly employed concentration-sensitive detectors across the oligomeric region, and the loss of oligomers through the accumulation wall membrane in asymmetric flow field-flow fractionation. The battle is not lost, however, because, with some care and given a sufficient supply of sample, the quantitation of both individual oligomeric species and of the total oligomeric region is often possible.

  4. Single channel speech separation in modulation frequency domain based on a novel pitch range estimation method

    NASA Astrophysics Data System (ADS)

    Mahmoodzadeh, Azar; Abutalebi, Hamid Reza; Soltanian-Zadeh, Hamid; Sheikhzadeh, Hamid

    2012-12-01

    Computational Auditory Scene Analysis (CASA) has been the focus in recent literature for speech separation from monaural mixtures. The performance of current CASA systems on voiced speech separation strictly depends on the robustness of the algorithm used for pitch frequency estimation. We propose a new system that estimates pitch (frequency) range of a target utterance and separates voiced portions of target speech. The algorithm, first, estimates the pitch range of target speech in each frame of data in the modulation frequency domain, and then, uses the estimated pitch range for segregating the target speech. The method of pitch range estimation is based on an onset and offset algorithm. Speech separation is performed by filtering the mixture signal with a mask extracted from the modulation spectrogram. A systematic evaluation shows that the proposed system extracts the majority of target speech signal with minimal interference and outperforms previous systems in both pitch extraction and voiced speech separation.

  5. Production and separation of no-carrier-added radioactive tracers of yttrium, strontium and rubidium from heavy-ion irradiated germanium target: applicability to the standardization of a separation technique for production of positron-emitting radionuclide 86Y.

    PubMed

    Pal, Sujit; Chattopadhyay, Sankha; Das, M K; Sudersanan, M

    2006-12-01

    Among various positron-emitting radionuclides, certain radioisotopes of Y, Sr and Rb have important applications in diagnostic and therapeutic nuclear medicine. In the present work, an attempt has been made to produce some of those radioisotopes by irradiating a natural Ge-target material with heavy-ion oxygen ((16)O(+6)) projectiles. An effective radiochemical separation scheme was developed to isolate Y, Sr and Rb radiotracers from the irradiated Ge-matrix in no-carrier-added form with a view to applying those radiotracers for standardization of a technique for the radiochemical separation of Y from natural Sr target. The standardized separation technique could be utilized for the production of the positron-emitting (86)Y from an enriched (86)Sr target irradiated at a medical cyclotron.

  6. A low sample volume particle separation device with electrokinetic pumping based on circular travelling-wave electroosmosis.

    PubMed

    Lin, Shiang-Chi; Lu, Jau-Ching; Sung, Yu-Lung; Lin, Chih-Ting; Tung, Yi-Chung

    2013-08-07

    Particle separation is a crucial step in sample preparation processes. The preparation of low volume samples is especially important for clinical diagnosis and chemical analysis. The advantages of microfluidic techniques have lead them to become potential candidates for particle separation. However, existing microfluidic devices require external pumping sources and extensive geometric patterns to attain high separation efficiency, which is disadvantageous when handling low volume samples. This paper presents a low sample volume particle separation microfluidic device with low voltage electrokinetic pumping based on circular travelling-wave electroosmosis (TWEO). Computational numerical software was utilized to simulate two electrokinetic mechanisms: circular TWEO and dielectrophoresis (DEP). The circular TWEO shear flow generates a velocity gradient in the radial direction which causes a shear stress-induced force to drag particles into the center region of the device. In contrast, the non-parallel electrodes induce negative DEP forces which push polystyrene beads towards the peripheral regions; the magnitude of the DEP forces are dependent on the sizes of the polystyrene beads. We used particles of various sizes to experimentally prove the concept of particle separation. Our experiments show that 15 μm beads are dragged into the center region due to the shear stress-induced force, and 1 μm beads move towards the outer region because of the large negative DEP force. The results show a separation purity of 94.4% and 80.0% for 15 μm and 1 μm beads respectively. We further demonstrated particle isolation from a sample of containing a small proportion of 6 μm beads mixed with 1 μm beads at a concentration ratio of 1 : 300. Therefore, the innovative device developed in this paper provides a promising solution to allow particle separation in sample volumes as low as 50 nL.

  7. An efficient solution technique for shockwave-boundary layer interactions with flow separation and slot suction effects

    NASA Technical Reports Server (NTRS)

    Edwards, Jack R.; Mcrae, D. Scott

    1991-01-01

    An efficient method for computing two-dimensional compressible Navier-Stokes flow fields is presented. The solution algorithm is a fully-implicit approximate factorization technique based on an unsymmetric line Gauss-Seidel splitting of the equation system Jacobian matrix. Convergence characteristics are improved by the addition of acceleration techniques based on Shamanskii's method for nonlinear equations and Broyden's quasi-Newton update. Characteristic-based differencing of the equations is provided by means of Van Leer's flux vector splitting. In this investigation, emphasis is placed on the fast and accurate computation of shock-wave-boundary layer interactions with and without slot suction effects. In the latter context, a set of numerical boundary conditions for simulating the transpiration flow in an open slot is devised. Both laminar and turbulent cases are considered, with turbulent closure provided by a modified Cebeci-Smith algebraic model. Comparisons with computational and experimental data sets are presented for a variety of interactions, and a fully-coupled simulation of a plenum chamber/inlet flowfield with shock interaction and suction is also shown and discussed.

  8. Chemometric experimental design based optimization techniques in capillary electrophoresis: a critical review of modern applications.

    PubMed

    Hanrahan, Grady; Montes, Ruthy; Gomez, Frank A

    2008-01-01

    A critical review of recent developments in the use of chemometric experimental design based optimization techniques in capillary electrophoresis applications is presented. Current advances have led to enhanced separation capabilities of a wide range of analytes in such areas as biological, environmental, food technology, pharmaceutical, and medical analysis. Significant developments in design, detection methodology and applications from the last 5 years (2002-2007) are reported. Furthermore, future perspectives in the use of chemometric methodology in capillary electrophoresis are considered.

  9. A Compound fault diagnosis for rolling bearings method based on blind source separation and ensemble empirical mode decomposition.

    PubMed

    Wang, Huaqing; Li, Ruitong; Tang, Gang; Yuan, Hongfang; Zhao, Qingliang; Cao, Xi

    2014-01-01

    A Compound fault signal usually contains multiple characteristic signals and strong confusion noise, which makes it difficult to separate week fault signals from them through conventional ways, such as FFT-based envelope detection, wavelet transform or empirical mode decomposition individually. In order to improve the compound faults diagnose of rolling bearings via signals' separation, the present paper proposes a new method to identify compound faults from measured mixed-signals, which is based on ensemble empirical mode decomposition (EEMD) method and independent component analysis (ICA) technique. With the approach, a vibration signal is firstly decomposed into intrinsic mode functions (IMF) by EEMD method to obtain multichannel signals. Then, according to a cross correlation criterion, the corresponding IMF is selected as the input matrix of ICA. Finally, the compound faults can be separated effectively by executing ICA method, which makes the fault features more easily extracted and more clearly identified. Experimental results validate the effectiveness of the proposed method in compound fault separating, which works not only for the outer race defect, but also for the rollers defect and the unbalance fault of the experimental system.

  10. Charge-based separation of proteins and peptides by electrically induced dynamic pH profiles.

    PubMed

    Brod, E; S Ben-Yosef, V; Bandhakavi, S; Sivan, U

    2016-01-29

    A new method for generating complex, dynamic pH profiles in an ampholyte-free separation channel is presented together with the theory behind its operation. The pH is modulated by an array of proton and hydroxide ion injectors placed along the separation channel. The ions generated in-situ by electrically driven water splitting across a bipolar membrane are injected to the channel in the presence of a longitudinal electric field, leading to the formation of a multi-step pH profile. Real-time control over the pH profile along the channel facilitates new dynamic separation strategies as well as steering and harvesting of focused molecules, which are both impossible with conventional separation methods. These freedoms are particularly attractive for Lab-on-a-Chip applications. The pH step-like profile alleviates one of the main hurdles of conventional isoelectric separation methods, namely, the slowing down of focused molecules as they approach their focusing spot. As a result, separation is completed within minutes for both peptides and proteins, even with low applied electric fields. We demonstrate protein and peptide separation within minutes, and resolution of ΔpI=0.2. Novel separation strategies based on spatio-temporal pH control are demonstrated as well.

  11. Continuous size-based separation of microparticles in a microchannel with symmetric sharp corner structures.

    PubMed

    Fan, Liang-Liang; He, Xu-Kun; Han, Yu; Du, Li; Zhao, Liang; Zhe, Jiang

    2014-03-01

    A new microchannel with a series of symmetric sharp corner structures is reported for passive size-dependent particle separation. Micro particles of different sizes can be completely separated based on the combination of the inertial lift force and the centrifugal force induced by the sharp corner structures in the microchannel. At appropriate flow rate and Reynolds number, the centrifugal force effect on large particles, induced by the sharp corner structures, is stronger than that on small particles; hence after passing a series of symmetric sharp corner structures, large particles are focused to the center of the microchannel, while small particles are focused at two particle streams near the two side walls of the microchannel. Particles of different sizes can then be completely separated. Particle separation with this device was demonstrated using 7.32 μm and 15.5 μm micro particles. Experiments show that in comparison with the prior multi-orifice flow fractionation microchannel and multistage-multiorifice flow fractionation microchannel, this device can completely separate two-size particles with narrower particle stream band and larger separation distance between particle streams. In addition, it requires no sheath flow and complex multi-stage separation structures, avoiding the dilution of analyte sample and complex operations. The device has potentials to be used for continuous, complete particle separation in a variety of lab-on-a-chip and biomedical applications.

  12. The detection of bulk explosives using nuclear-based techniques

    SciTech Connect

    Morgado, R.E.; Gozani, T.; Seher, C.C.

    1988-01-01

    In 1986 we presented a rationale for the detection of bulk explosives based on nuclear techniques that addressed the requirements of civil aviation security in the airport environment. Since then, efforts have intensified to implement a system based on thermal neutron activation (TNA), with new work developing in fast neutron and energetic photon reactions. In this paper we will describe these techniques and present new results from laboratory and airport testing. Based on preliminary results, we contended in our earlier paper that nuclear-based techniques did provide sufficiently penetrating probes and distinguishable detectable reaction products to achieve the FAA operational goals; new data have supported this contention. The status of nuclear-based techniques for the detection of bulk explosives presently under investigation by the US Federal Aviation Administration (FAA) is reviewed. These include thermal neutron activation (TNA), fast neutron activation (FNA), the associated particle technique, nuclear resonance absorption, and photoneutron activation. The results of comprehensive airport testing of the TNA system performed during 1987-88 are summarized. From a technical point of view, nuclear-based techniques now represent the most comprehensive and feasible approach for meeting the operational criteria of detection, false alarms, and throughput. 9 refs., 5 figs., 2 tabs.

  13. Enantiomeric separation of biaryl atropisomers using cyclofructan based chiral stationary phases.

    PubMed

    Woods, Ross M; Patel, Darshan C; Lim, Yeeun; Breitbach, Zachary S; Gao, Hongyin; Keene, Craig; Li, Gongqiang; Kürti, László; Armstrong, Daniel W

    2014-08-29

    Normal phase chiral HPLC methods are presented for the enantiomeric separation of 30 biaryl atropisomers including 18 new compounds recently produced via a novel synthetic approach. Three new cyclofructan based chiral stationary phases were evaluated. Separations were achieved for all but six analytes and the LARIHC™ CF6-P alone provided 15 baseline separations. Effects of polar modifiers and temperature effects also were studied. Apparent thermodynamic parameters were determined by van't Hoff plots. Preparative scale methods were developed and employed resulting in the first ever isolation of these novel atropisomers in their pure enantiomeric form. Insights into the mechanism of retention and chiral discrimination are presented.

  14. Enantiomeric Separation of Biaryl Atropisomers Using Cyclofructan Based Chiral Stationary Phases

    PubMed Central

    Woods, Ross M.; Patel, Darshan C.; Lim, Yeeun; Breitbach, Zachary S.; Gao, Hongyin; Keene, Craig; Li, Gongqiang; Kürti, László

    2014-01-01

    Normal phase chiral HPLC methods are presented for the enantiomeric separation of 30 biaryl atropisomers including 18 new compounds recently produced via a novel synthetic approach. Three new cyclofructan based chiral stationary phases were evaluated. Separations were achieved for all but six analytes and the LARIHC™ CF6-P alone provided 15 baseline separations. Effects of polar modifiers and temperature effects also were studied. Apparent thermodynamic parameters were determined by van't Hoff plots. Preparative scale methods were developed and employed resulting in the first ever isolation of these novel atropisomers in their pure enantiomeric form. Insights into the mechanism of retention and chiral discrimination are presented. PMID:24835594

  15. Aluminum oxyhydroxide based separator/electrolyte and battery system, and a method making the same

    SciTech Connect

    Gerald, II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.

    2011-03-08

    The instant invention relates a solid-state electrochemical cell and a novel separator/electrolyte incorporated therein. A preferred embodiment of the invented electrochemical cell generally comprises a unique metal oxyhydroxide based (i.e. AlOOH) separator/electrolyte membrane sandwiched between a first electrode and a second electrode. A preferred novel separator/electrolyte comprises a nanoparticulate metal oxyhydroxide, preferably AlOOH and a salt which are mixed and then pressed together to form a monolithic metal oxyhydroxide-salt membrane.

  16. Influence of anionic species on uranium separation from acid mine water using strong base resins.

    PubMed

    Ladeira, Ana Claudia Queiroz; Gonçalves, Carlos Renato

    2007-09-30

    The presence of uranium and other elements in high concentrations in acid mine drainage at Poços de Caldas Uranium Mine (Brazil) is a matter of concern. The acid water pH is around 2.7, the uranium concentration is in the range of 6-14 mg L(-1), sulfate concentration near 1400 mg L(-1), fluoride 140 mg L(-1) and iron 180 mg L(-1). In this solution, where sulfate is present in elevated concentrations, uranium is basically in the form of UO(2)(SO(4))(3)(4-). This study investigated the separation of uranium from the other anions present in the acid water under batch and column mode using ion exchange technique. The pH studied was 2.7 and 3.9. Two strong base anionic resins were tested. The influence of ions, commonly found in acid waters like sulfate and fluoride, on ion exchange process was also assessed. Equilibrium studies were carried out to determine the maximum adsorption capacities of the resins. The resins showed a significant capacity for uranium uptake which varied from 66 to 108 mg g(-1) for IRA 910U and 53 to 79 mg g(-1) for Dowex A. The results also showed that SO(4)(2-) is the most interfering ion and it had a deleterious effect on the recovery in the pH range studied. Fluoride did not affect uranium removal.

  17. Separation of piracetam derivatives on polysaccharide-based chiral stationary phases.

    PubMed

    Kažoka, H; Koliškina, O; Veinberg, G; Vorona, M

    2013-03-15

    High-performance liquid chromatography was used for the enantiomeric separation of two chiral piracetam derivatives. The suitability of six commercially available polysaccharide-based chiral stationary phases (CSPs) under normal phase mode for direct enantioseparation has been investigated. The influence of the CSPs as well the nature and content of an alcoholic modifier in the mobile phase on separation and elution order was studied. It was established that CSP Lux Amylose-2 shows high chiral recognition ability towards 4-phenylsubstituted piracetam derivatives.

  18. Characterization and application of a semi-automated separation and analysis technique for polychlorinated biphenyls in Great Lakes wildlife

    SciTech Connect

    Williams, L.L.

    1993-01-01

    Polychlorinated hydrocarbons (PCHs) are toxic, persistent compounds in the environment. The non-ortho substituted PCB congeners comprise most of the Ah receptor-mediated PCH toxicity in aquatic systems. The proportion of the most toxic congeners to the total concentration of PCBs is suspected to vary in the environment, but these congeners are difficult to quantify. The studies described here focus on the development and use of a semi-automated separation of the non-ortho substituted congeners from interferences using porous graphitic carbon (PGC). The PGC method developed it faster and uses less solvent than previous separations based on carbon columns. This method is both precise and accurate, with no discernable interferences. Results obtained from this method can be used with TCDD equivalency factors (TEFs) to calculate TCDD-equivalents (TEQs) derived from PCBs. The PGC method was used successfully to measure PCB congeners in eggs of fish-eating birds. Variability in TEQ and PCB concentrations among eggs within a double-crested cormorant colony was investigated. No significant differences in concentrations of PCBs to TEQs were observed among eggs from nests with different reproductive outcomes; therefore, concentrations of TEQs and PCBs could not be related to reproductive success of nests within a single colony. TEQs determined in an H4IIE bioassay for EROD activity were significantly greater than TEQs calculated from concentrations of PCB congeners. In another study, concentrations of TEQs and PCBs in red-breasted merganser eggs collected 13 years apart were compared. Concentrations of TEQs and PCBs declined significantly between 1977 and 1990, but the ratio of TEQ to total PCBH did not change.

  19. Ionic liquid-based materials: a platform to design engineered CO2 separation membranes.

    PubMed

    Tomé, Liliana C; Marrucho, Isabel M

    2016-05-21

    During the past decade, significant advances in ionic liquid-based materials for the development of CO2 separation membranes have been accomplished. This review presents a perspective on different strategies that use ionic liquid-based materials as a unique tuneable platform to design task-specific advanced materials for CO2 separation membranes. Based on compilation and analysis of the data hitherto reported, we provide a judicious assessment of the CO2 separation efficiency of different membranes, and highlight breakthroughs and key challenges in this field. In particular, configurations such as supported ionic liquid membranes, polymer/ionic liquid composite membranes, gelled ionic liquid membranes and poly(ionic liquid)-based membranes are detailed, discussed and evaluated in terms of their efficiency, which is attributed to their chemical and structural features. Finally, an integrated perspective on technology, economy and sustainability is provided.

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

    PubMed

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

    2013-11-05

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

  1. Interaction of High Flash Point Electrolytes and PE-Based Separators for Li-Ion Batteries.

    PubMed

    Hofmann, Andreas; Kaufmann, Christoph; Müller, Marcus; Hanemann, Thomas

    2015-08-27

    In this study, promising electrolytes for use in Li-ion batteries are studied in terms of interacting and wetting polyethylene (PE) and particle-coated PE separators. The electrolytes are characterized according to their physicochemical properties, where the flow characteristics and the surface tension are of particular interest for electrolyte-separator interactions. The viscosity of the electrolytes is determined to be in a range of η = 4-400 mPa∙s and surface tension is finely graduated in a range of γL = 23.3-38.1 mN∙m(-1). It is verified that the technique of drop shape analysis can only be used in a limited matter to prove the interaction, uptake and penetration of electrolytes by separators. Cell testing of Li|NMC half cells reveals that those cell results cannot be inevitably deduced from physicochemical electrolyte properties as well as contact angle analysis. On the other hand, techniques are more suitable which detect liquid penetration into the interior of the separator. It is expected that the results can help fundamental researchers as well as users of novel electrolytes in current-day Li-ion battery technologies for developing and using novel material combinations.

  2. Interaction of High Flash Point Electrolytes and PE-Based Separators for Li-Ion Batteries

    PubMed Central

    Hofmann, Andreas; Kaufmann, Christoph; Müller, Marcus; Hanemann, Thomas

    2015-01-01

    In this study, promising electrolytes for use in Li-ion batteries are studied in terms of interacting and wetting polyethylene (PE) and particle-coated PE separators. The electrolytes are characterized according to their physicochemical properties, where the flow characteristics and the surface tension are of particular interest for electrolyte–separator interactions. The viscosity of the electrolytes is determined to be in a range of η = 4–400 mPa∙s and surface tension is finely graduated in a range of γL = 23.3–38.1 mN∙m−1. It is verified that the technique of drop shape analysis can only be used in a limited matter to prove the interaction, uptake and penetration of electrolytes by separators. Cell testing of Li|NMC half cells reveals that those cell results cannot be inevitably deduced from physicochemical electrolyte properties as well as contact angle analysis. On the other hand, techniques are more suitable which detect liquid penetration into the interior of the separator. It is expected that the results can help fundamental researchers as well as users of novel electrolytes in current-day Li-ion battery technologies for developing and using novel material combinations. PMID:26343636

  3. Single-channel mixed signal blind source separation algorithm based on multiple ICA processing

    NASA Astrophysics Data System (ADS)

    Cheng, Xiefeng; Li, Ji

    2017-01-01

    Take separating the fetal heart sound signal from the mixed signal that get from the electronic stethoscope as the research background, the paper puts forward a single-channel mixed signal blind source separation algorithm based on multiple ICA processing. Firstly, according to the empirical mode decomposition (EMD), the single-channel mixed signal get multiple orthogonal signal components which are processed by ICA. The multiple independent signal components are called independent sub component of the mixed signal. Then by combining with the multiple independent sub component into single-channel mixed signal, the single-channel signal is expanded to multipath signals, which turns the under-determined blind source separation problem into a well-posed blind source separation problem. Further, the estimate signal of source signal is get by doing the ICA processing. Finally, if the separation effect is not very ideal, combined with the last time's separation effect to the single-channel mixed signal, and keep doing the ICA processing for more times until the desired estimated signal of source signal is get. The simulation results show that the algorithm has good separation effect for the single-channel mixed physiological signals.

  4. Wavelet-based techniques for the gamma-ray sky

    DOE PAGES

    McDermott, Samuel D.; Fox, Patrick J.; Cholis, Ilias; ...

    2016-07-01

    Here, we demonstrate how the image analysis technique of wavelet decomposition can be applied to the gamma-ray sky to separate emission on different angular scales. New structures on scales that differ from the scales of the conventional astrophysical foreground and background uncertainties can be robustly extracted, allowing a model-independent characterization with no presumption of exact signal morphology. As a test case, we generate mock gamma-ray data to demonstrate our ability to extract extended signals without assuming a fixed spatial template. For some point source luminosity functions, our technique also allows us to differentiate a diffuse signal in gamma-rays from darkmore » matter annihilation and extended gamma-ray point source populations in a data-driven way.« less

  5. Wavelet-based techniques for the gamma-ray sky

    SciTech Connect

    McDermott, Samuel D.; Fox, Patrick J.; Cholis, Ilias; Lee, Samuel K.

    2016-07-01

    Here, we demonstrate how the image analysis technique of wavelet decomposition can be applied to the gamma-ray sky to separate emission on different angular scales. New structures on scales that differ from the scales of the conventional astrophysical foreground and background uncertainties can be robustly extracted, allowing a model-independent characterization with no presumption of exact signal morphology. As a test case, we generate mock gamma-ray data to demonstrate our ability to extract extended signals without assuming a fixed spatial template. For some point source luminosity functions, our technique also allows us to differentiate a diffuse signal in gamma-rays from dark matter annihilation and extended gamma-ray point source populations in a data-driven way.

  6. Efficient Plant Supervision Strategy Using NN Based Techniques

    NASA Astrophysics Data System (ADS)

    Garcia, Ramon Ferreiro; Rolle, Jose Luis Calvo; Castelo, Francisco Javier Perez

    Most of non-linear type one and type two control systems suffers from lack of detectability when model based techniques are applied on FDI (fault detection and isolation) tasks. In general, all types of processes suffer from lack of detectability also due to the ambiguity to discriminate the process, sensors and actuators in order to isolate any given fault. This work deals with a strategy to detect and isolate faults which include massive neural networks based functional approximation procedures associated to recursive rule based techniques applied to a parity space approach.

  7. Towards DMD-Based Estimation and Control of Flow Separation using an Array of Surface Pressure Sensors

    NASA Astrophysics Data System (ADS)

    Deem, Eric; Cattafesta, Louis; Zhang, Hao; Rowley, Clancy

    2016-11-01

    Closed-loop control of flow separation requires the spatio-temporal states of the flow to be fed back through the controller in real time. Previously, static and dynamic estimation methods have been employed that provide reduced-order model estimates of the POD-coefficients of the flow velocity using surface pressure measurements. However, this requires a "learning" dataset a priori. This approach is effective as long as the dynamics during control do not stray from the learning dataset. Since only a few dynamical features are required for feedback control of flow separation, many of the details provided by full-field snapshots are superfluous. This motivates a state-observation technique that extracts key dynamical features directly from surface pressure, without requiring PIV snapshots. The results of identifying DMD modes of separated flow through an array of surface pressure sensors in real-time are presented. This is accomplished by employing streaming DMD "on the fly" to surface pressure snapshots. These modal characteristics exhibit striking similarities to those extracted from PIV data and the pressure field obtained via solving Poisson's equation. Progress towards closed-loop separation control based on the dynamic modes of surface pressure will be discussed. Supported by AFOSR Grant FA9550-14-1-0289.

  8. Design of Low-Cost FPGA Hardware for Real-time ICA-Based Blind Source Separation Algorithm

    NASA Astrophysics Data System (ADS)

    Charoensak, Charayaphan; Sattar, Farook

    2005-12-01

    Blind source separation (BSS) of independent sources from their convolutive mixtures is a problem in many real-world multisensor applications. In this paper, we propose and implement an efficient FPGA hardware architecture for the realization of a real-time BSS. The architecture can be implemented using a low-cost FPGA (field programmable gate array). The architecture offers a good balance between hardware requirement (gate count and minimal clock speed) and separation performance. The FPGA design implements the modified Torkkola's BSS algorithm for audio signals based on ICA (independent component analysis) technique. Here, the separation is performed by implementing noncausal filters, instead of the typical causal filters, within the feedback network. This reduces the required length of the unmixing filters as well as provides better separation and faster convergence. Description of the hardware as well as discussion of some issues regarding the practical hardware realization are presented. Results of various FPGA simulations as well as real-time testing of the final hardware design in real environment are given.

  9. Community-based surveillance to monitor trends in unaccompanied and separated children in eastern DRC.

    PubMed

    Rubenstein, Beth L; Spencer, Craig; Mansourian, Hani; Noble, Eva; Munganga, Gustave B; Stark, Lindsay

    2015-12-01

    Children who are separated from their families and usual caregivers in emergencies face a multitude of risks. The humanitarian community lacks methods to systematically capture changes in the frequency and nature of such separations over time. A mobile phone-based community surveillance system was piloted in the Democratic Republic of the Congo. The goal was to identify new cases of unaccompanied and separated children on a weekly basis. Over an 11-week period, community focal points reported 62 cases of separation across 10 communities. The majority of children had been under the care of their parents prior to separation. More than half of the children were unaccompanied, meaning that they were living without an adult relative or customary caregiver. The pilot results suggest that implementing a mobile phone-based surveillance system in a humanitarian setting may be feasible and cost-effective and fills a critical gap in the measurement of separated and unaccompanied children in emergencies. A longer pilot to better understand how the system performs over time is recommended.

  10. High temperature stable Li-ion battery separators based on polyetherimides with improved electrolyte compatibility

    NASA Astrophysics Data System (ADS)

    l'Abee, Roy; DaRosa, Fabien; Armstrong, Mark J.; Hantel, Moritz M.; Mourzagh, Djamel

    2017-03-01

    We report (electro-)chemically stable, high temperature resistant and fast wetting Li-ion battery separators produced through a phase inversion process using novel polyetherimides (PEI) based on bisphenol-aceton diphthalic anhydride (BPADA) and para-phenylenediamine (pPD). In contrast to previous studies using PEI based on BPADA and meta-phenylenediamine (mPD), the separators reported herein show limited swelling in electrolytes and do not require fillers to render sufficient mechanical strength and ionic conductivity. In this work, the produced 15-25 μm thick PEI-pPD separators show excellent electrolyte compatibility, proven by low degrees of swelling in electrolyte solvents, low contact angles, fast electrolyte wicking and high electrolyte uptake. The separators cover a tunable range of morphologies and properties, leading to a wide range of ionic conductivities as studied by Electrochemical Impedance Spectroscopy (EIS). Dynamic Mechanical Analysis (DMA) demonstrated dimensional stability up to 220 °C. Finally, single layer graphite/lithium nickel manganese cobalt oxide (NMC) pouch cells were assembled using this novel PEI-pPD separator, showing an excellent capacity retention of 89.3% after 1000 1C/2C cycles, with a mean Coulombic efficiency of 99.77% and limited resistance build-up. We conclude that PEI-pPD is a promising new material candidate for high performance separators.

  11. Clustering Algorithm for Unsupervised Monaural Musical Sound Separation Based on Non-negative Matrix Factorization

    NASA Astrophysics Data System (ADS)

    Park, Sang Ha; Lee, Seokjin; Sung, Koeng-Mo

    Non-negative matrix factorization (NMF) is widely used for monaural musical sound source separation because of its efficiency and good performance. However, an additional clustering process is required because the musical sound mixture is separated into more signals than the number of musical tracks during NMF separation. In the conventional method, manual clustering or training-based clustering is performed with an additional learning process. Recently, a clustering algorithm based on the mel-frequency cepstrum coefficient (MFCC) was proposed for unsupervised clustering. However, MFCC clustering supplies limited information for clustering. In this paper, we propose various timbre features for unsupervised clustering and a clustering algorithm with these features. Simulation experiments are carried out using various musical sound mixtures. The results indicate that the proposed method improves clustering performance, as compared to conventional MFCC-based clustering.

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

    PubMed

    Rathore, A S; Shirke, A

    2011-01-01

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

  13. Active control of massively separated high-speed/base flows with electric arc plasma actuators

    NASA Astrophysics Data System (ADS)

    DeBlauw, Bradley G.

    The current project was undertaken to evaluate the effects of electric arc plasma actuators on high-speed separated flows. Two underlying goals motivated these experiments. The first goal was to provide a flow control technique that will result in enhanced flight performance for supersonic vehicles by altering the near-wake characteristics. The second goal was to gain a broader and more sophisticated understanding of these complex, supersonic, massively-separated, compressible, and turbulent flow fields. The attainment of the proposed objectives was facilitated through energy deposition from multiple electric-arc plasma discharges near the base corner separation point. The control authority of electric arc plasma actuators on a supersonic axisymmetric base flow was evaluated for several actuator geometries, frequencies, forcing modes, duty cycles/on-times, and currents. Initially, an electric arc plasma actuator power supply and control system were constructed to generate the arcs. Experiments were performed to evaluate the operational characteristics, electromagnetic emission, and fluidic effect of the actuators in quiescent ambient air. The maximum velocity induced by the arc when formed in a 5 mm x 1.6 mm x 2 mm deep cavity was about 40 m/s. During breakdown, the electromagnetic emission exhibited a rise and fall in intensity over a period of about 340 ns. After breakdown, the emission stabilized to a near-constant distribution. It was also observed that the plasma formed into two different modes: "high-voltage" and "low-voltage". It is believed that the plasma may be switching between an arc discharge and a glow discharge for these different modes. The two types of plasma do not appear to cause substantial differences on the induced fluidic effects of the actuator. In general, the characterization study provided a greater fundamental understanding of the operation of the actuators, as well as data for computational model comparison. Preliminary investigations

  14. Separation of soybean isoflavone aglycone homologues by ionic liquid-based extraction.

    PubMed

    Cao, Yifeng; Xing, Huabin; Yang, Qiwei; Bao, Zongbi; Su, Baogen; Yang, Yiwen; Ren, Qilong

    2012-04-04

    The separation of a compound of interest from its structurally similar homologues is an important and challenging problem in producing high-purity natural products, such as the separation of genistein from other soybean isoflavone aglycone (SIA) homologues. The present work provided a novel method for separating genistein from its structurally similar homologues by ionic liquid (IL)-based liquid-liquid extraction using hydrophobic IL-water or hydrophilic IL/water-ethyl acetate biphasic systems. Factors that influence the distribution equilibrium of SIAs, including the structure and concentration of IL, pH value of the aqueous phase, and temperature, were investigated. Adequate distribution coefficients and selectivities over 7.0 were achieved with hydrophilic IL/water-ethyl acetate biphasic system. Through a laboratory-scale simulation of fractional extraction process containing four extraction stages and four scrubbing stages, genistein was separated from the SIA homologues with a purity of 95.3% and a recovery >90%.

  15. Separating stratiform and convective rain types based on the drop size distribution characteristics using 2D video disdrometer data

    NASA Astrophysics Data System (ADS)

    Thurai, M.; Gatlin, P. N.; Bringi, V. N.

    2016-03-01

    A technique for separating stratiform and convective rain types using the characteristics of two of the main drop size distribution (DSD) parameters is presented. The method was originally developed based on observations from dual-frequency profiler and dual-polarization radar observations in Darwin, Australia. In this paper, we will present the testing of the method using data from 2D video disdrometers (2DVD) from two very different locations, namely, Ontario, Canada, and Huntsville, Alabama, USA. One-minute DSDs from 2DVD are used as input to a gamma-fitting procedure and our separation technique uses the fitted values of log10(NW) and D0 (where NW is the scaling parameter and D0 is the median volume diameter) and an "index" to quantify where the points lie in the log10(NW) versus D0 domain. For the Ontario location, the output of the classification is compared with simultaneous observations from a collocated, vertically pointing, X-band Doppler radar. A "bright-band" detection algorithm is used to classify each height profile as either stratiform or convective, depending on whether or not a clearly defined melting layer is present at an expected height. If present, the maximum reflectivity within the melting layer and the corresponding height are determined. Similar testing is carried out for two events in Huntsville and compared with observations from a collocated UHF profiler (with Doppler capability). Additional case studies are required, but these results indicate our separation technique seems to be applicable to many different locations and climatologies based on previously published data.

  16. Diode laser based water vapor DIAL using modulated pulse technique

    NASA Astrophysics Data System (ADS)

    Pham, Phong Le Hoai; Abo, Makoto

    2014-11-01

    In this paper, we propose a diode laser based differential absorption lidar (DIAL) for measuring lower-tropospheric water vapor profile using the modulated pulse technique. The transmitter is based on single-mode diode laser and tapered semiconductor optical amplifier with a peak power of 10W around 800nm absorption band, and the receiver telescope diameter is 35cm. The selected wavelengths are compared to referenced wavelengths in terms of random error and systematic errors. The key component of modulated pulse technique, a macropulse, is generated with a repetition rate of 10 kHz, and the modulation within the macropulse is coded according to a pseudorandom sequence with 100ns chip width. As a result, we evaluate both single pulse modulation and pseudorandom coded pulse modulation technique. The water vapor profiles conducted from these modulation techniques are compared to the real observation data in summer in Japan.

  17. Dissociation techniques in mass spectrometry-based proteomics.

    PubMed

    Jones, Andrew W; Cooper, Helen J

    2011-09-07

    The field of proteomics, the large-scale analysis of proteins, has undergone a huge expansion over the past decade. Mass spectrometry-based proteomics relies on the dissociation of peptide and/or protein ions to provide information on primary sequence and sites of post-translational modifications. Fragmentation techniques include collision-induced dissociation, electron capture dissociation and electron transfer dissociation. Here, we describe each of these techniques and their use in proteomics. The principles, advantages, limitations, and applications are discussed.

  18. Image analysis techniques associated with automatic data base generation.

    NASA Technical Reports Server (NTRS)

    Bond, A. D.; Ramapriyan, H. K.; Atkinson, R. J.; Hodges, B. C.; Thomas, D. T.

    1973-01-01

    This paper considers some basic problems relating to automatic data base generation from imagery, the primary emphasis being on fast and efficient automatic extraction of relevant pictorial information. Among the techniques discussed are recursive implementations of some particular types of filters which are much faster than FFT implementations, a 'sequential similarity detection' technique of implementing matched filters, and sequential linear classification of multispectral imagery. Several applications of the above techniques are presented including enhancement of underwater, aerial and radiographic imagery, detection and reconstruction of particular types of features in images, automatic picture registration and classification of multiband aerial photographs to generate thematic land use maps.

  19. Model based separation of transmitted and received signal for single transducer distance measurement applications

    NASA Astrophysics Data System (ADS)

    Schröder, A.; Henning, B.

    2012-05-01

    Single transducer distance measurement systems have a blind zone which is increased if the transmitted signals are coded to reduce errors due to crosstalk. A method to reduce this blind zone is a model based separation of the transmitted and received signal. This contribution compares two systems, one working with the measured band pass signals, and another one which is based on I/Q-demodulated base band signals.

  20. Evaluation of two immunomagnetic separation techniques for the detection and recovery of E. coli O157:H7 from finished composts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two rapid immunomagnetic separation (IMS) protocols were evaluated to recover 1-2 log CFU/g inoculated E. coli O157:H7 from 30 different commercial, finished compost samples. Both protocols detected E. coli O157:H7 in compost samples; PCR techniques required the removal of inhibitors to reduce poss...

  1. Novel Perfluorinated Polymer-Based Pervaporation Membranes for Separation of Solvent/Water Mixtures.

    PubMed

    Smuleac, V; Wu, J; Nemser, S; Majumdar, S; Bhattacharyya, D

    2010-04-15

    Traditionally, the pervaporation of water-solvent mixtures where the solvent is the major component is performed using hydrophilic membranes (such as PVA or zeolites). In the present paper a new type of pervaporation membrane (amorphous perfluorinated polymer, hydrophobic) was studied for separation of water-solvent mixtures. This membrane has high free volume and is inert for all solvents, and has a remarkable mechanical, chemical and thermal stability. The water is transported by solution diffusion model and the separation of solvent is primarily based on molecular sieving (size exclusion) principles. The membrane shows a high stability for operation over a broad range of feed concentrations without swelling; the operating temperature does not have a significant effect on membrane separation performance. Separation factors as high as 349 and 500 for water-ethanol and water-IPA mixtures (2-98 % wt water-solvent) and fluxes of 0.15 and 0.05 kg/m(2)h, respectively were obtained at 22 °C. The permeance-based selectivities were also calculated, and the selectivity is approximately constant for a wide range of feed concentrations. The pervaporation of more complex (ternary) mixtures of water-ethanol-ethyl acetate showed that this system could be successfully applied for solute separation based on size exclusion.

  2. A new technique for minimally invasive abdominal wall reconstruction of complex incisional hernias: totally laparoscopic component separation and incisional hernia repair.

    PubMed

    Moazzez, Ashkan; Mason, Rodney J; Katkhouda, Namir

    2010-10-01

    Since Ramirez et al. presented the first case of component separation for abdominal wall hernias in 1990, it has undergone multiple modifications. This technique, which has been mainly used for large hernias where primary closure of the abdominal wall is not feasible, or for staged management of patients with open abdomens, results in multiple wound complications. In 2007, Rosen et al. reported on the laparoscopic approach to component separation that is associated with less subcutaneous dissection and the consequent advantage of a decreased risk of flap necrosis and wound infection. Here we discuss our totally laparoscopic approach to abdominal wall reconstruction. A minimally invasive abdominal wall reconstruction consists of a bilateral component separation, an intra-abdominal adhesiolysis, primary approximation of rectus muscles, and placement of an intraperitoneal mesh for reinforcing the repair, all performed laparoscopically. Patient-selection criteria, detailed operative technique, tips in preventing and managing the potential pitfalls, and postoperative care are discussed.

  3. Pig slurry acidification and separation techniques affect soil N and C turnover and N2O emissions from solid, liquid and biochar fractions.

    PubMed

    Gómez-Muñoz, B; Case, S D C; Jensen, L S

    2016-03-01

    The combined effects of pig slurry acidification, subsequent separation techniques and biochar production from the solid fraction on N mineralisation and N2O and CO2 emissions in soil were investigated in an incubation experiment. Acidification of pig slurry increased N availability from the separated solid fractions in soil, but did not affect N2O and CO2 emissions. However acidification reduced soil N and C turnover from the liquid fraction. The use of more advanced separation techniques (flocculation and drainage > decanting centrifuge > screw press) increased N mineralisation from acidified solid fractions, but also increased N2O and CO2 emissions in soil amended with the liquid fraction. Finally, the biochar production from the solid fraction of pig slurry resulted in a very recalcitrant material, which reduced N and C mineralisation in soil compared to the raw solid fractions.

  4. The load separation technique in the elastic-plastic fracture analysis of two- and three-dimensional geometries

    NASA Technical Reports Server (NTRS)

    Sharobeam, Monir H.

    1994-01-01

    Load separation is the representation of the load in the test records of geometries containing cracks as a multiplication of two separate functions: a crack geometry function and a material deformation function. Load separation is demonstrated in the test records of several two-dimensional geometries such as compact tension geometry, single edge notched bend geometry, and center cracked tension geometry and three-dimensional geometries such as semi-elliptical surface crack. The role of load separation in the evaluation of the fracture parameter J-integral and the associated factor eta for two-dimensional geometries is discussed. The paper also discusses the theoretical basis and the procedure for using load separation as a simplified yet accurate approach for plastic J evaluation in semi-elliptical surface crack which is a three-dimensional geometry. The experimental evaluation of J, and particularly J(sub pl), for three-dimensional geometries is very challenging. A few approaches have been developed in this regard and they are either complex or very approximate. The paper also presents the load separation as a mean to identify the blunting and crack growth regions in the experimental test records of precracked specimens. Finally, load separation as a methodology in elastic-plastic fracture mechanics is presented.

  5. Toner and paper-based fabrication techniques for microfluidic applications.

    PubMed

    Coltro, Wendell Karlos Tomazelli; de Jesus, Dosil Pereira; da Silva, José Alberto Fracassi; do Lago, Claudimir Lucio; Carrilho, Emanuel

    2010-08-01

    The interest in low-cost microfluidic platforms as well as emerging microfabrication techniques has increased considerably over the last years. Toner- and paper-based techniques have appeared as two of the most promising platforms for the production of disposable devices for on-chip applications. This review focuses on recent advances in the fabrication techniques and in the analytical/bioanalytical applications of toner and paper-based devices. The discussion is divided in two parts dealing with (i) toner and (ii) paper devices. Examples of miniaturized devices fabricated by using direct-printing or toner transfer masking in polyester-toner, glass, PDMS as well as conductive platforms as recordable compact disks and printed circuit board are presented. The construction and the use of paper-based devices for off-site diagnosis and bioassays are also described to cover this emerging platform for low-cost diagnostics.

  6. Separation studies of As(III), Sb(III) and Bi(III) by reversed-phase paper chromatographic technique

    SciTech Connect

    Raman, B.; Shinde, V.M.

    1987-07-01

    Reversed-phase paper chromatographic separations of As(III), Sb(III) and Bi(III) have been carried out on Whatman No 1 filter paper impregnated with triphenylphosphine oxide as stationary phase and using organic complexing agents such as sodium acetate, sodium succinate and sodium malonate solutions as active mobile phases. Results for the separation of binary and ternary mixtures are reported and the method has been successfully applied to the separation and detection of these elements present in real samples and at ppm level concentration.

  7. Laser-based direct-write techniques for cell printing.

    PubMed

    Schiele, Nathan R; Corr, David T; Huang, Yong; Raof, Nurazhani Abdul; Xie, Yubing; Chrisey, Douglas B

    2010-09-01

    Fabrication of cellular constructs with spatial control of cell location (+/-5 microm) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing.

  8. Laser-based direct-write techniques for cell printing

    PubMed Central

    Schiele, Nathan R; Corr, David T; Huang, Yong; Raof, Nurazhani Abdul; Xie, Yubing; Chrisey, Douglas B

    2016-01-01

    Fabrication of cellular constructs with spatial control of cell location (±5 μm) is essential to the advancement of a wide range of applications including tissue engineering, stem cell and cancer research. Precise cell placement, especially of multiple cell types in co- or multi-cultures and in three dimensions, can enable research possibilities otherwise impossible, such as the cell-by-cell assembly of complex cellular constructs. Laser-based direct writing, a printing technique first utilized in electronics applications, has been adapted to transfer living cells and other biological materials (e.g., enzymes, proteins and bioceramics). Many different cell types have been printed using laser-based direct writing, and this technique offers significant improvements when compared to conventional cell patterning techniques. The predominance of work to date has not been in application of the technique, but rather focused on demonstrating the ability of direct writing to pattern living cells, in a spatially precise manner, while maintaining cellular viability. This paper reviews laser-based additive direct-write techniques for cell printing, and the various cell types successfully laser direct-written that have applications in tissue engineering, stem cell and cancer research are highlighted. A particular focus is paid to process dynamics modeling and process-induced cell injury during laser-based cell direct writing. PMID:20814088

  9. A novel viscoelastic-based ferrofluid for continuous sheathless microfluidic separation of nonmagnetic microparticles.

    PubMed

    Zhang, Jun; Yan, Sheng; Yuan, Dan; Zhao, Qianbin; Tan, Say Hwa; Nguyen, Nam-Trung; Li, Weihua

    2016-10-05

    Separation of microparticles has found broad applications in biomedicine, industry and clinical diagnosis. In a conventional aqueous ferrofluid, separation of microparticles usually employs a sheath flow or two offset magnets to confine particle streams for downstream particle sorting. This complicates the fluid control, device fabrication, and dilutes the particle sample. In this work, we propose and develop a novel viscoelastic ferrofluid by replacing the Newtonian base medium of the conventional ferrofluid with non-Newtonian poly(ethylene oxide) (PEO) aqueous solution. The properties of both viscoelastic 3D focusing and negative magnetophoresis of the viscoelastic ferrofluid were verified and investigated. By employing the both properties in a serial manner, continuous and sheathless separation of nonmagnetic particles based on particle size has been demonstrated. This novel viscoelastic ferrofluid is expected to bring more flexibility and versatility to the design and functionality in microfluidic devices.

  10. Heat-Flow-Driven Oligonucleotide Gelation Separates Single-Base Differences.

    PubMed

    Morasch, Matthias; Braun, Dieter; Mast, Christof B

    2016-06-01

    DNA phase transitions are often induced by the addition of condensation agents or by dry concentration. Herein, we show that the non-equilibrium setting of a moderate heat flow across a water-filled chamber separates and gelates DNA strands with single-base resolution. A dilute mix of DNA with two slightly different gel-forming sequences separates into sequence-pure hydrogels under constant physiological solvent conditions. A single base change in a 36 mer DNA inhibits gelation. Only sequences with the ability to form longer strands are concentrated, further elongated, and finally gelated by length-dependent thermal trapping. No condensation agents, such as multivalent ions, were added. Equilibrium aggregates from dry concentration did not show any sequence separation. RNA is expected to behave identically owing to its equal thermophoretic properties. The highly sequence-specific phase transition points towards new possibilities for non-equilibrium origins of life.

  11. Fully automated objective-based method for master recession curve separation.

    PubMed

    Posavec, Kristijan; Parlov, Jelena; Nakić, Zoran

    2010-01-01

    The fully automated objective-based method for master recession curve (MRC) separation was developed by using Microsoft Excel spreadsheet and Visual Basic for Applications (VBA) code. The core of the program code is used to construct an MRC by using the adapted matching strip method (Posavec et al. 2006). Criteria for separating the MRC into two or three segments are determined from the flow-duration curve and are represented as the probable range of percent of flow rate duration. Successive separations are performed automatically on two and three MRCs using sets of percent of flow rate duration from selected ranges and an optimal separation model scenario, having the highest average coefficient of determination R(2), is selected as the most appropriate one. The resulting separated master recession curves are presented graphically, whereas the statistics are presented numerically, all in separate sheets. Examples of field data obtained from two springs in Istria, Croatia, are used to illustrate its application. The freely available Excel spreadsheet and VBA program ensures the ease of use and applicability for larger data sets.

  12. An overview of the use of microchips in electrophoretic separation techniques: fabrication, separation modes, sample preparation opportunities, and on-chip detection.

    PubMed

    Hendrickx, Stijn; de Malsche, Wim; Cabooter, Deirdre

    2015-01-01

    This chapter is intended as a basic introduction to microchip-based capillary electrophoresis to set the scene for newcomers and give pointers to reference material. An outline of some commonly used setups and key concepts is given, many of which are explored in greater depth in later chapters.

  13. A simple and rapid technique for radiochemical separation of iodine radionuclides from irradiated tellurium using an activated charcoal column.

    PubMed

    Chattopadhyay, Sankha; Saha Das, Sujata

    2009-10-01

    A simple and inexpensive method for the separation of medically useful no-carrier-added (nca) iodine radionuclides from bulk amounts of irradiated tellurium dioxide (TeO(2)) target was developed. The beta(-) emitting (131)I radionuclide, produced by the decay of (131)Te through the (nat)Te(n, gamma)(131)Te nuclear reaction, was used for standardization of the radiochemical separation procedure. The radiochemical separation was performed by precipitation followed by column (activated charcoal) chromatography. Quantitative post-irradiation recovery of the TeO(2) target material (98-99%), in a form suitable for reuse in future irradiations, was achieved. The overall radiochemical yield for the complete separation of (131)I was 75-85% (n=8). The separated nca (131)I was of high, approximately 99%, radionuclidic and radiochemical purities and did not contain detectable amounts of the target material. This method can be adopted for the radiochemical separation of other different iodine radionuclides produced from tellurium matrices through cyclotron as well as reactor irradiation.

  14. Integrated separation of blood plasma from whole blood for microfluidic paper-based analytical devices.

    PubMed

    Yang, Xiaoxi; Forouzan, Omid; Brown, Theodore P; Shevkoplyas, Sergey S

    2012-01-21

    Many diagnostic tests in a conventional clinical laboratory are performed on blood plasma because changes in its composition often reflect the current status of pathological processes throughout the body. Recently, a significant research effort has been invested into the development of microfluidic paper-based analytical devices (μPADs) implementing these conventional laboratory tests for point-of-care diagnostics in resource-limited settings. This paper describes the use of red blood cell (RBC) agglutination for separating plasma from finger-prick volumes of whole blood directly in paper, and demonstrates the utility of this approach by integrating plasma separation and a colorimetric assay in a single μPAD. The μPAD was fabricated by printing its pattern onto chromatography paper with a solid ink (wax) printer and melting the ink to create hydrophobic barriers spanning through the entire thickness of the paper substrate. The μPAD was functionalized by spotting agglutinating antibodies onto the plasma separation zone in the center and the reagents of the colorimetric assay onto the test readout zones on the periphery of the device. To operate the μPAD, a drop of whole blood was placed directly onto the plasma separation zone of the device. RBCs in the whole blood sample agglutinated and remained in the central zone, while separated plasma wicked through the paper substrate into the test readout zones where analyte in plasma reacted with the reagents of the colorimetric assay to produce a visible color change. The color change was digitized with a portable scanner and converted to concentration values using a calibration curve. The purity and yield of separated plasma was sufficient for successful operation of the μPAD. This approach to plasma separation based on RBC agglutination will be particularly useful for designing fully integrated μPADs operating directly on small samples of whole blood.

  15. Separation of nuclear isomers for cancer therapeutic radionuclides based on nuclear decay after-effects

    NASA Astrophysics Data System (ADS)

    Bhardwaj, R.; van der Meer, A.; Das, S. K.; de Bruin, M.; Gascon, J.; Wolterbeek, H. T.; Denkova, A. G.; Serra-Crespo, P.

    2017-03-01

    177Lu has sprung as a promising radionuclide for targeted therapy. The low soft tissue penetration of its β‑ emission results in very efficient energy deposition in small-size tumours. Because of this, 177Lu is used in the treatment of neuroendocrine tumours and is also clinically approved for prostate cancer therapy. In this work, we report a separation method that achieves the challenging separation of the physically and chemically identical nuclear isomers, 177mLu and 177Lu. The separation method combines the nuclear after-effects of the nuclear decay, the use of a very stable chemical complex and a chromatographic separation. Based on this separation concept, a new type of radionuclide generator has been devised, in which the parent and the daughter radionuclides are the same elements. The 177mLu/177Lu radionuclide generator provides a new production route for the therapeutic radionuclide 177Lu and can bring significant growth in the research and development of 177Lu based pharmaceuticals.

  16. Separation of nuclear isomers for cancer therapeutic radionuclides based on nuclear decay after-effects.

    PubMed

    Bhardwaj, R; van der Meer, A; Das, S K; de Bruin, M; Gascon, J; Wolterbeek, H T; Denkova, A G; Serra-Crespo, P

    2017-03-13

    (177)Lu has sprung as a promising radionuclide for targeted therapy. The low soft tissue penetration of its β(-) emission results in very efficient energy deposition in small-size tumours. Because of this, (177)Lu is used in the treatment of neuroendocrine tumours and is also clinically approved for prostate cancer therapy. In this work, we report a separation method that achieves the challenging separation of the physically and chemically identical nuclear isomers, (177m)Lu and (177)Lu. The separation method combines the nuclear after-effects of the nuclear decay, the use of a very stable chemical complex and a chromatographic separation. Based on this separation concept, a new type of radionuclide generator has been devised, in which the parent and the daughter radionuclides are the same elements. The (177m)Lu/(177)Lu radionuclide generator provides a new production route for the therapeutic radionuclide (177)Lu and can bring significant growth in the research and development of (177)Lu based pharmaceuticals.

  17. Separation of nuclear isomers for cancer therapeutic radionuclides based on nuclear decay after-effects

    PubMed Central

    Bhardwaj, R.; van der Meer, A.; Das, S. K.; de Bruin, M.; Gascon, J.; Wolterbeek, H. T.; Denkova, A. G.; Serra-Crespo, P.

    2017-01-01

    177Lu has sprung as a promising radionuclide for targeted therapy. The low soft tissue penetration of its β− emission results in very efficient energy deposition in small-size tumours. Because of this, 177Lu is used in the treatment of neuroendocrine tumours and is also clinically approved for prostate cancer therapy. In this work, we report a separation method that achieves the challenging separation of the physically and chemically identical nuclear isomers, 177mLu and 177Lu. The separation method combines the nuclear after-effects of the nuclear decay, the use of a very stable chemical complex and a chromatographic separation. Based on this separation concept, a new type of radionuclide generator has been devised, in which the parent and the daughter radionuclides are the same elements. The 177mLu/177Lu radionuclide generator provides a new production route for the therapeutic radionuclide 177Lu and can bring significant growth in the research and development of 177Lu based pharmaceuticals. PMID:28287131

  18. Mechanical modeling of battery separator based on microstructure image analysis and stochastic characterization

    NASA Astrophysics Data System (ADS)

    Xu, Hongyi; Zhu, Min; Marcicki, James; Yang, Xiao Guang

    2017-03-01

    A microstructure-based modeling method is developed to predict the mechanical behaviors of lithium-ion battery separators. Existing battery separator modeling methods cannot capture the structural features on the microscale. To overcome this issue, we propose an image-based microstructure Representative Volume Element (RVE) modeling method, which facilitates the understanding of the separators' complex macro mechanical behaviors from the perspective of microstructural features. A generic image processing workflow is developed to identify different phases in the microscopic image. The processed RVE image supplies microstructural information to the Finite Element Analysis (FEA). Both mechanical behavior and microstructure evolution are obtained from the simulation. The evolution of microstructure features is quantified using the stochastic microstructure characterization methods. The proposed method successfully captures the anisotropic behavior of the separator under tensile test, and provides insights into the microstructure deformation, such as the growth of voids. We apply the proposed method to a commercially available separator as the demonstration. The analysis results are validated using experimental testing results that are reported in literature.

  19. Dip-separated structural filtering using seislet transform and adaptive empirical mode decomposition based dip filter

    NASA Astrophysics Data System (ADS)

    Chen, Yangkang

    2016-07-01

    The seislet transform has been demonstrated to have a better compression performance for seismic data compared with other well-known sparsity promoting transforms, thus it can be used to remove random noise by simply applying a thresholding operator in the seislet domain. Since the seislet transform compresses the seismic data along the local structures, the seislet thresholding can be viewed as a simple structural filtering approach. Because of the dependence on a precise local slope estimation, the seislet transform usually suffers from low compression ratio and high reconstruction error for seismic profiles that have dip conflicts. In order to remove the limitation of seislet thresholding in dealing with conflicting-dip data, I propose a dip-separated filtering strategy. In this method, I first use an adaptive empirical mode decomposition based dip filter to separate the seismic data into several dip bands (5 or 6). Next, I apply seislet thresholding to each separated dip component to remove random noise. Then I combine all the denoised components to form the final denoised data. Compared with other dip filters, the empirical mode decomposition based dip filter is data-adaptive. One only needs to specify the number of dip components to be separated. Both complicated synthetic and field data examples show superior performance of my proposed approach than the traditional alternatives. The dip-separated structural filtering is not limited to seislet thresholding, and can also be extended to all those methods that require slope information.

  20. Reduction of stochastic conductance-based neuron models with time-scales separation.

    PubMed

    Wainrib, Gilles; Thieullen, Michèle; Pakdaman, Khashayar

    2012-04-01

    We introduce a method for systematically reducing the dimension of biophysically realistic neuron models with stochastic ion channels exploiting time-scales separation. Based on a combination of singular perturbation methods for kinetic Markov schemes with some recent mathematical developments of the averaging method, the techniques are general and applicable to a large class of models. As an example, we derive and analyze reductions of different stochastic versions of the Hodgkin Huxley (HH) model, leading to distinct reduced models. The bifurcation analysis of one of the reduced models with the number of channels as a parameter provides new insights into some features of noisy discharge patterns, such as the bimodality of interspike intervals distribution. Our analysis of the stochastic HH model shows that, besides being a method to reduce the number of variables of neuronal models, our reduction scheme is a powerful method for gaining understanding on the impact of fluctuations due to finite size effects on the dynamics of slow fast systems. Our analysis of the reduced model reveals that decreasing the number of sodium channels in the HH model leads to a transition in the dynamics reminiscent of the Hopf bifurcation and that this transition accounts for changes in characteristics of the spike train generated by the model. Finally, we also examine the impact of these results on neuronal coding, notably, reliability of discharge times and spike latency, showing that reducing the number of channels can enhance discharge time reliability in response to weak inputs and that this phenomenon can be accounted for through the analysis of the reduced model.

  1. Fractionation of Exosomes and DNA using Size-Based Separation at the Nanoscale

    NASA Astrophysics Data System (ADS)

    Wunsch, Benjamin; Smith, Joshua; Wang, Chao; Gifford, Stacey; Brink, Markus; Bruce, Robert; Solovitzky, Gustavo; Austin, Robert; Astier, Yann

    Exosomes, a key target of ``liquid biopsies'', are nano-vesicles found in nearly all biological fluids. Exosomes are secreted by eukaryotic and prokaryotic cells alike, and contain information about their originating cells, including surface proteins, cytoplasmic proteins, and nucleic acids. One challenge in studying exosome morphology is the difficulty of sorting exosomes by size and surface markers. Common separation techniques for exosomes include ultracentrifugation and ultrafiltration, for preparation of large volume samples, but these techniques often show contamination and significant heterogeneity between preparations. To date, deterministic lateral displacement (DLD) pillar arrays in silicon have proven an efficient technology to sort, separate, and enrich micron-scale particles including human parasites, eukaryotic cells, blood cells, and circulating tumor cells in blood; however, the DLD technology has never been translated to the true nanoscale, where it could function on bio-colloids such as exosomes. We have fabricated nanoscale DLD (nanoDLD) arrays capable of rapidly sorting colloids down to 20 nm in continuous flow, and demonstrated size sorting of individual exosome vesicles and dsDNA polymers, opening the potential for on-chip biomolecule separation and diagnosti

  2. Application of Silica-Based Hyper-Crosslinked Sulfonate-Modified Reversed Stationary Phases for Separating Highly Hydrophilic Basic Compounds

    PubMed Central

    Luo, Hao; Ma, Lianjia; Paek, Changyub; Carr, Peter W.

    2008-01-01

    The separation and determination of hydrophilic basic compounds are of great importance in many fields including clinical and biological research, pharmaceutical development and forensic analysis. However, the most widely used analytical separation technique in these disciplines, reversed-phase liquid chromatography (RPLC), usually does not provide sufficient retention for several of the important classes of highly hydrophilic basic compounds including catecholamines, many drug metabolites and many drugs of abuse. Commonly eluents having little or no organic modifier and/or strong ion pairing agents must be used to achieve sufficient retention and separation. Use of highly aqueous eluents can lead to column failure by dewetting, resulting in poor retention, selectivity, reproducibility and slow recovery of performance. The use of a strong ion pairing agent to increase retention renders the separation incompatible with mass spectrometric detection and complicates preparative separations. This paper describes the successful applications of a novel type of silica-based, hyper-crosslinked, sulfonate-modified reversed stationary phase, denoted as −SO3-HC-C8-L, for the separation of highly hydrophilic cations and related compounds by a hydrophobically assisted cation-exchange mechanism. Compared to conventional reversed-phases, the −SO3-HC-C8-L phase showed significantly improved retention and separation selectivity. Concurrently, due to the presence of both cation-exchange and reversed-phase retention mechanisms and the high acid stability of hyper-crosslinked phases, the separation can be optimized by changing the type or concentration of ionic additive or organic modifier, and by varying the column temperature. In addition, gradients generated by programming the concentration of either the ionic additive or the organic modifier can be applied to reduce the analysis time without compromising resolution. Furthermore, remarkably different chromatographic

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

    EPA Science Inventory

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

    Leland M. Vane, Ph.D.
    U.S. Environmental Protection Agency
    Office of Research & Development
    Cincinnati, OH 45268
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  4. Metal-organic framework-based separator for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Bai, Songyan; Liu, Xizheng; Zhu, Kai; Wu, Shichao; Zhou, Haoshen

    2016-07-01

    Lithium-sulfur batteries are a promising energy-storage technology due to their relatively low cost and high theoretical energy density. However, one of their major technical problems is the shuttling of soluble polysulfides between electrodes, resulting in rapid capacity fading. Here, we present a metal-organic framework (MOF)-based battery separator to mitigate the shuttling problem. We show that the MOF-based separator acts as an ionic sieve in lithium-sulfur batteries, which selectively sieves Li+ ions while efficiently suppressing undesired polysulfides migrating to the anode side. When a sulfur-containing mesoporous carbon material (approximately 70 wt% sulfur content) is used as a cathode composite without elaborate synthesis or surface modification, a lithium-sulfur battery with a MOF-based separator exhibits a low capacity decay rate (0.019% per cycle over 1,500 cycles). Moreover, there is almost no capacity fading after the initial 100 cycles. Our approach demonstrates the potential for MOF-based materials as separators for energy-storage applications.

  5. Cholinium-based supported ionic liquid membranes: a sustainable route for carbon dioxide separation.

    PubMed

    Tomé, Liliana C; Patinha, David J S; Ferreira, Rui; Garcia, Helga; Silva Pereira, Cristina; Freire, Carmen S R; Rebelo, Luís Paulo N; Marrucho, Isabel M

    2014-01-01

    Aiming at full sustainability of CO2 separation processes, a series of supported ionic liquid membranes based on environmentally friendly cholinium carboxylate ionic liquids were successfully prepared. Their gas permeation properties were measured and high permselectivities were obtained for both CO2 /CH4 and CO2 /N2 .

  6. Concurrent DNA Preconcentration and Separation in Bipolar Electrode-Based Microfluidic Device

    PubMed Central

    Song, Hongjun; Wang, Yi; Garson, Charles; Pant, Kapil

    2015-01-01

    This paper presents a bipolar electrode (BPE) device in a microfluidic dual-channel design for concurrent preconcentration and separation of composite DNA containing samples. The novelty of the present effort relies on the combination of BPE-induced ion concentration polarization (ICP) and end-labeled free-solution electrophoresis (ELFSE). The ion concentration polarization effect arising from the faradaic reaction on the BPE is utilized to exert opposing electrophoretic and electroosmotic forces on the DNA samples. Meanwhile, end-labeled free-solution electrophoresis alters the mass-charge ratio to enable simultaneous DNA separation in free solution. The microfluidic device was fabricated using standard and soft lithography techniques to form gold-on-glass electrode capped with a PDMS microfluidic channel. Experimental testing with various DNA samples was carried out over a range of applied electric field. Concentration ratios up to 285× within 5 minutes for a 102-mer DNA, and concurrent preconcentration and free-solution separation of binary mixture of free and bound 102-mer DNA within 6 minutes was demonstrated. The effect of applied electric field was also interrogated with respect to pertinent performance metrics of preconcentration and separation. PMID:26005497

  7. A Novel Nanofabrication Technique of Silicon-Based Nanostructures.

    PubMed

    Meng, Lingkuan; He, Xiaobin; Gao, Jianfeng; Li, Junjie; Wei, Yayi; Yan, Jiang

    2016-12-01

    A novel nanofabrication technique which can produce highly controlled silicon-based nanostructures in wafer scale has been proposed using a simple amorphous silicon (α-Si) material as an etch mask. SiO2 nanostructures directly fabricated can serve as nanotemplates to transfer into the underlying substrates such as silicon, germanium, transistor gate, or other dielectric materials to form electrically functional nanostructures and devices. In this paper, two typical silicon-based nanostructures such as nanoline and nanofin have been successfully fabricated by this technique, demonstrating excellent etch performance. In addition, silicon nanostructures fabricated above can be further trimmed to less than 10 nm by combing with assisted post-treatment methods. The novel nanofabrication technique will be expected a new emerging technology with low process complexity and good compatibility with existing silicon integrated circuit and is an important step towards the easy fabrication of a wide variety of nanoelectronics, biosensors, and optoelectronic devices.

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

    PubMed

    Carasek, Eduardo; Merib, Josias

    2015-06-23

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

  9. A Novel Nanofabrication Technique of Silicon-Based Nanostructures

    NASA Astrophysics Data System (ADS)

    Meng, Lingkuan; He, Xiaobin; Gao, Jianfeng; Li, Junjie; Wei, Yayi; Yan, Jiang

    2016-11-01

    A novel nanofabrication technique which can produce highly controlled silicon-based nanostructures in wafer scale has been proposed using a simple amorphous silicon (α-Si) material as an etch mask. SiO2 nanostructures directly fabricated can serve as nanotemplates to transfer into the underlying substrates such as silicon, germanium, transistor gate, or other dielectric materials to form electrically functional nanostructures and devices. In this paper, two typical silicon-based nanostructures such as nanoline and nanofin have been successfully fabricated by this technique, demonstrating excellent etch performance. In addition, silicon nanostructures fabricated above can be further trimmed to less than 10 nm by combing with assisted post-treatment methods. The novel nanofabrication technique will be expected a new emerging technology with low process complexity and good compatibility with existing silicon integrated circuit and is an important step towards the easy fabrication of a wide variety of nanoelectronics, biosensors, and optoelectronic devices.

  10. Performance Metrics for Depth-based Signal Separation Using Deep Vertical Line Arrays

    NASA Astrophysics Data System (ADS)

    Boyle, John K.

    Vertical line arrays (VLAs) deployed below the critical depth in the deep ocean can exploit reliable acoustic path (RAP) propagation, which provides low transmission loss (TL) for targets at moderate ranges, and increased TL for distant interferers. However, sound from nearby surface interferers also undergoes RAP propagation, and without horizontal aperture, a VLA cannot separate these interferers from submerged targets. A recent publication by McCargar and Zurk (2013) addressed this issue, presenting a transform-based method for passive, depth-based separation of signals received on deep VLAs based on the depth-dependent modulation caused by the interference between the direct and surface-reflected acoustic arrivals. This thesis expands on that work by quantifying the transform-based depth estimation method performance in terms of the resolution and ambiguity in the depth estimate. Then, the depth discrimination performance is quantified in terms of the number of VLA elements.

  11. Enhance separations with electricity

    SciTech Connect

    Muralidhara, H.S.

    1994-05-01

    To satisfy growing environmental regulations, control energy costs, or just to stay competitive, one must improve existing separation technologies and make them more efficient. New challenges in food processing and requirements for novel purification technologies in the biotech industry also will require more efficient separation techniques. This paper discusses some enhanced separation processes based on the application of an electric field in the combined-fields approach. In a combined-fields approach, the emphasis is on the generation of additional driving forces to work simultaneously with the conventional driving force of the process. Here the authors concentrate on the application of an electric field to generate the additional driving force.

  12. Chiral Separations

    NASA Astrophysics Data System (ADS)

    Stalcup, A. M.

    2010-07-01

    The main goal of this review is to provide a brief overview of chiral separations to researchers who are versed in the area of analytical separations but unfamiliar with chiral separations. To researchers who are not familiar with this area, there is currently a bewildering array of commercially available chiral columns, chiral derivatizing reagents, and chiral selectors for approaches that span the range of analytical separation platforms (e.g., high-performance liquid chromatography, gas chromatography, supercritical-fluid chromatography, and capillary electrophoresis). This review begins with a brief discussion of chirality before examining the general strategies and commonalities among all of the chiral separation techniques. Rather than exhaustively listing all the chiral selectors and applications, this review highlights significant issues and differences between chiral and achiral separations, providing salient examples from specific classes of chiral selectors where appropriate.

  13. An improved cell separation technique for marine subsurface sediments: applications for high-throughput analysis using flow cytometry and cell sorting

    PubMed Central

    Morono, Yuki; Terada, Takeshi; Kallmeyer, Jens; Inagaki, Fumio

    2013-01-01

    Summary Development of an improved technique for separating microbial cells from marine sediments and standardization of a high-throughput and discriminative cell enumeration method were conducted. We separated microbial cells from various types of marine sediment and then recovered the cells using multilayer density gradients of sodium polytungstate and/or Nycodenz, resulting in a notably higher percent recovery of cells than previous methods. The efficiency of cell extraction generally depends on the sediment depth; using the new technique we developed, more than 80% of the total cells were recovered from shallow sediment samples (down to 100 meters in depth), whereas ∼ 50% of cells were recovered from deep samples (100–365 m in depth). The separated cells could be rapidly enumerated using flow cytometry (FCM). The data were in good agreement with those obtained from manual microscopic direct counts over the range 104–108 cells cm−3. We also demonstrated that sedimentary microbial cells can be efficiently collected using a cell sorter. The combined use of our new cell separation and FCM/cell sorting techniques facilitates high-throughput and precise enumeration of microbial cells in sediments and is amenable to various types of single-cell analyses, thereby enhancing our understanding of microbial life in the largely uncharacterized deep subseafloor biosphere. PMID:23731283

  14. Blind separation of convolutive sEMG mixtures based on independent vector analysis

    NASA Astrophysics Data System (ADS)

    Wang, Xiaomei; Guo, Yina; Tian, Wenyan

    2015-12-01

    An independent vector analysis (IVA) method base on variable-step gradient algorithm is proposed in this paper. According to the sEMG physiological properties, the IVA model is applied to the frequency-domain separation of convolutive sEMG mixtures to extract motor unit action potentials information of sEMG signals. The decomposition capability of proposed method is compared to the one of independent component analysis (ICA), and experimental results show the variable-step gradient IVA method outperforms ICA in blind separation of convolutive sEMG mixtures.

  15. Sheath-Free Elasto-Inertia Separation of Particles Based on Shape in Straight Rectangular Microchannels

    NASA Astrophysics Data System (ADS)

    Xuan, Xiangchun; Lu, Xinyu

    2016-11-01

    We demonstrate the use of straight rectangular microchannels to obtain a shape-based separation of equal-volumed spherical and peanut-shaped particles in viscoelastic fluids. This continuous sheath-free separation arises from the shape-dependent equilibrium particle positions as a result of the flow-induced elasto-inertial lift. A continuous transition from single to dual and to triple equilibrium positions is observed for both types of particles with the increase of flow rate. However, the flow rate at which the transition occurs differs with the particle shape, which is thought to correlate the rotational effects of non-spherical particles.

  16. [Separation of enantiomers by supercritical fluid chromatography on polysaccharide derivative-based chiral stationary phases].

    PubMed

    Li, Dongyan; Wu, Xi; Hao, Fangli; Yang, Yang; Chen, Xiaoming

    2016-01-01

    Eleven kinds of chiral compounds have been well separated within 10 min on polysaccharide derivative-based chiral stationary phases named Chiralpak IA, IB, IC, ID, IE and IF by supercritical fluid chromatography (SFC). The chiral recognition of these chiral compounds has demonstrated good complementary enantioselectivities of the six chiral columns, which were proved to be useful for chiral SFC. Both the elution time and enantioselectivies could be significantly affected by the modifier types and their concentrations, such as methanol, ethanol and isopropanol, which should be optimized during the experiments. In addition, the solvent versatility of the immobilized chiral stationary phase on the optimization of the chiral separation was helpful.

  17. Synthesis and Characterization of Thiazolium-Based Room Temperature Ionic Liquids for Gas Separations

    SciTech Connect

    Hillesheim, Patrick C; Mahurin, Shannon Mark; Fulvio, Pasquale F; Yeary, Joshua S; Oyola, Yatsandra; Jiang, Deen; Dai, Sheng

    2012-01-01

    A series of novel thiazolium-bis(triflamide) based ionic liquids has been synthesized and characterized. Physicochemical properties of the ionic liquids such as thermal stability, phase transitions, and infrared spectra were analysed and compared to the imidazolium-based congeners. Several unique classes of ancillary substitutions are examined with respect to impacts on overall structure, in addition to their carbon dioxide absorption properties in supported ionic-liquid membranes for gas separation.

  18. Fission-Product Separation Based on Room-Temperature Ionic Liquids

    SciTech Connect

    Luo, Huimin; Hussey, Charles L.

    2005-09-30

    The objectives of this project are (a) to synthesize new ionic liquids tailored for the extractive separation of Cs + and Sr 2+; (b) to select optimum macrocyclic extractants through studies of complexation of fission products with macrocyclic extractants and transport in new extraction systems based on ionic liquids; (c) to develop efficient processes to recycle ionic liquids and crown ethers; and (d) to investigate chemical stabilities of ionic liquids under strong acid, strong base, and high-level-radiation conditions.

  19. Synthesis and Characterization of Thiazolium-Based Room Temperature Ionic Liquids for Gas Separations

    SciTech Connect

    Hillesheim, PC; Mahurin, SM; Fulvio, PF; Yeary, JS; Oyola, Y; Jiang, DE; Dai, S

    2012-09-05

    A series of novel thiazolium-bis(triflamide) based ionic liquids has been synthesized and characterized. Physicochemical properties of the ionic liquids such as thermal stability, phase transitions, and infrared spectra were analyzed and compared to the imidazolium-based congeners. Several unique classes of ancillary substitutions are examined with respect to impacts on overall structure, in addition to their carbon dioxide absorption properties in supported ionic-liquid membranes for gas separation.

  20. Size-based separation and collection of mouse pancreatic islets for functional analysis.

    PubMed

    Nam, Ki-Hwan; Yong, Wang; Harvat, Tricia; Adewola, Adeola; Wang, Shesun; Oberholzer, Jose; Eddington, David T

    2010-10-01

    Islet size has recently been demonstrated to be an important factor in determining human islet transplantation outcomes. In this study, a multi-layered microfluidic device was developed and quantified for size-based separation of a heterogeneous population of mouse islets. The device was fabricated using standard soft lithography and polydimethylsiloxane (PDMS). Size-based separation was first demonstrated via injection of a heterogeneous population of glass beads between 50-300 microm in diameter which were separated into five sub-populations based on their diameter. Next, a heterogeneous population of mouse pancreatic islets, between 50-250 microm in diameter was separated into four sub-populations. Throughout this process the islets remained intact without any signs of damage, as indicated by cell viability staining. Islet glucose-stimulated insulin secretion of each sub-population of islets was also evaluated demonstrating that islets smaller than 150 microm have superior stimulation indexes (SI) compared to islets larger than 150 microm. In this study, we found that islets between 100 microm and 150 microm in diameter had the greatest SI value in a heterogeneous population of islets.

  1. Continuous separation of racemic 3,5-dinitrobenzoyl-amino acids in a centrifugal contact separator with the aid of cinchona-based chiral host compounds.

    PubMed

    Hallett, Andrew J; Kwant, Gerard J; de Vries, Johannes G

    2009-01-01

    Resolution through revolution: It is possible to extract 3,5-dinitrobenzoyl-protected amino acids enantioselectively with the aid of a table-top centrifugal contact separator and a catalytic amount of a chiral host compound based on the Cinchona alkaloids. Enantioselectivities of up to 80 % could be reached in a single pass. This allows the development of a process for the continuous separation of racemates.The resolution of racemates is mostly performed by crystallisation of diastereomeric salts. Direct physical separation could be much more efficient, but so far most concepts, with the exception of SMB, have proven to be non-scaleable. Here we report the first scalable process for the resolution of N-protected amino acid derivatives through selective extraction, with the aid of a catalytic amount of a chiral host compound based on Cinchona alkaloids. The method hinges on the use of centrifugal contact separators (CCSs) for fast mixing and separation. Although the highest ee obtained was only 80 %, the concept can be extended through the use of a series of CCSs in countercurrent mode to effect full separation.

  2. Membrane gas separation. January 1970-May 1981 (citations from the Engineering Index Data Base). Report for Jan 70-May 81

    SciTech Connect

    Not Available

    1981-05-01

    This retrospective bibliography discusses the current literature on gas separation and purification using polymeric and metallic membranes. Included are topics such as isotope separation, osmotic techniques, reverse osmosis and preparation of membranes for specific separation processes. The permeability of polymer membranes is discussed in terms of physical properties of the membrane as well as its molecular structure. The selectivity of polymeric films for a variety of gases is also considered. (Contains 51 citations fully indexed and including a title list.)

  3. Membrane gas separation. January 1976-May 1981 (citations from the Energy Data Base). Report for Jan 76-May 81

    SciTech Connect

    Not Available

    1981-05-01

    This retrospective bibliography discusses the current literature on gas separation and purification using polymeric and metallic membranes. Included are topics such as isotope separation, osmotic techniques, reverse osmosis and preparation of membranes for specific separation processes. The permeability of polymer membranes is discussed in terms of physical properties of the membrane as well as its molecular structure. The selectivity of polymeric films for a variety of gases is also considered. (Contains 65 citations fully indexed and including a title list.)

  4. Membrane gas separation. January 1970-May 1981 (citations from the NTIS data base). Report for Jan 70-May 81

    SciTech Connect

    Not Available

    1981-05-01

    This retrospective bibliography discusses the current literature on gas separation and purification using polymeric and metallic membranes. Included are topics such as isotope separation, osmotic techniques, reverse osmosis, and preparation of membranes for specific separation processes. The permeability of polymer membranes is discussed in terms of physical properties, of the membrane as well as its molecular structure. The selectivity of polymeric films for a variety of gases is also considered. (Contains 78 citations fully indexed and including a title list.)

  5. Impact of tuning CO2-philicity in polydimethylsiloxane-based membranes for carbon dioxide separation

    DOE PAGES

    Hong, Tao; Chatterjee, Sabornie; Mahurin, Shannon M.; ...

    2017-02-22

    Amidoxime-functionalized polydimethylsiloxane (AO-PDMSPNB) membranes with various amidoxime compositions were synthesized via ring-opening metathesis polymerization followed by post-polymerization modification. Compared to other previously reported PDMS-based membranes, the amidoxime-functionalized membranes show enhanced CO2 permeability and CO2/N2 selectivity. The overall gas separation performance (CO2 permeability 6800 Barrer; CO2/N2 selectivity 19) of the highest performing membrane exceeds the Robeson upper bound line, and the excellent permeability of the copolymer itself provides great potential for real world applications where huge volumes of gases are separated. This study details how tuning the CO2-philicity within rubbery polymer matrices influences gas transport properties. Key parameters for tuning gasmore » transport properties are discussed, and the experimental results show good consistency with theoretical calculations. Finally, this study provides a roadmap to enhancing gas separation performance in rubbery polymers by tuning gas solubility selectivity.« less

  6. Gearbox coupling modulation separation method based on match pursuit and correlation filtering

    NASA Astrophysics Data System (ADS)

    He, Guolin; Ding, Kang; Lin, Huibin

    2016-01-01

    The vibration signal of faulty gearbox commonly involves complex coupling modulation components. The method of sparse representation has been successfully used for gearbox fault diagnosis, but most of the literatures only focus on the extraction of impact modulation and always neglect the steady modulation representing the distributed faults. This paper presents a new method for separating coupling modulation from vibration signal of gearbox based on match pursuit and correlation filtering. To separate the steady modulation caused by distributed fault and the impact modulation caused by impact fault, two sub-dictionaries are specially designed according to the gearbox operating and structural parameters and the characteristics of vibration signal. The new dictionaries have clear physical meaning and good adaptability. In addition, an amplitude recovery step is conducted to improve the matching accuracy in the match pursuit. Simulation and experimental results show that the proposed method can separate the coupling components of gearbox vibration signal effectively under intensive background noise.

  7. Optical supervised filtering technique based on Hopfield neural network

    NASA Astrophysics Data System (ADS)

    Bal, Abdullah

    2004-11-01

    Hopfield neural network is commonly preferred for optimization problems. In image segmentation, conventional Hopfield neural networks (HNN) are formulated as a cost-function-minimization problem to perform gray level thresholding on the image histogram or the pixels' gray levels arranged in a one-dimensional array [R. Sammouda, N. Niki, H. Nishitani, Pattern Rec. 30 (1997) 921-927; K.S. Cheng, J.S. Lin, C.W. Mao, IEEE Trans. Med. Imag. 15 (1996) 560-567; C. Chang, P. Chung, Image and Vision comp. 19 (2001) 669-678]. In this paper, a new high speed supervised filtering technique is proposed for image feature extraction and enhancement problems by modifying the conventional HNN. The essential improvement in this technique is to use 2D convolution operation instead of weight-matrix multiplication. Thereby, neural network based a new filtering technique has been obtained that is required just 3 × 3 sized filter mask matrix instead of large size weight coefficient matrix. Optical implementation of the proposed filtering technique is executed easily using the joint transform correlator. The requirement of non-negative data for optical implementation is provided by bias technique to convert the bipolar data to non-negative data. Simulation results of the proposed optical supervised filtering technique are reported for various feature extraction problems such as edge detection, corner detection, horizontal and vertical line extraction, and fingerprint enhancement.

  8. Video Multiple Watermarking Technique Based on Image Interlacing Using DWT

    PubMed Central

    Ibrahim, Mohamed M.; Abdel Kader, Neamat S.; Zorkany, M.

    2014-01-01

    Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT) is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video) are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth. PMID:25587570

  9. Video multiple watermarking technique based on image interlacing using DWT.

    PubMed

    Ibrahim, Mohamed M; Abdel Kader, Neamat S; Zorkany, M

    2014-01-01

    Digital watermarking is one of the important techniques to secure digital media files in the domains of data authentication and copyright protection. In the nonblind watermarking systems, the need of the original host file in the watermark recovery operation makes an overhead over the system resources, doubles memory capacity, and doubles communications bandwidth. In this paper, a robust video multiple watermarking technique is proposed to solve this problem. This technique is based on image interlacing. In this technique, three-level discrete wavelet transform (DWT) is used as a watermark embedding/extracting domain, Arnold transform is used as a watermark encryption/decryption method, and different types of media (gray image, color image, and video) are used as watermarks. The robustness of this technique is tested by applying different types of attacks such as: geometric, noising, format-compression, and image-processing attacks. The simulation results show the effectiveness and good performance of the proposed technique in saving system resources, memory capacity, and communications bandwidth.

  10. Capillary electrophoresis-based proteomic techniques for biomarker discovery.

    PubMed

    Fang, Xueping; Wang, Chenchen; Lee, Cheng S

    2013-01-01

    Besides proteome complexity, the greatest bioanalytical challenge facing comprehensive proteomic analysis, particularly in the identification of low abundance proteins, is related to the large variation of protein relative abundances. In contrast to universally enriching all analytes by a similar degree, the result of the capillary isotachophoresis (CITP) stacking process is that major components may be diluted, but trace compounds are concentrated. Such selective enhancement toward low abundance proteins drastically reduces the range of relative protein abundances within complex proteomes and greatly enhances the resulting proteome coverage. Furthermore, CITP offers seamless combination with nano-reversed phase liquid chromatography (nano-RPLC) as two highly resolving and completely orthogonal separation techniques critically needed for analyzing complex proteomes.

  11. FAIR exempting separate T (1) measurement (FAIREST): a novel technique for online quantitative perfusion imaging and multi-contrast fMRI.

    PubMed

    Lai, S; Wang, J; Jahng, G H

    2001-01-01

    A new pulse sequence, dubbed FAIR exempting separate T(1) measurement (FAIREST) in which a slice-selective saturation recovery acquisition is added in addition to the standard FAIR (flow-sensitive alternating inversion recovery) scheme, was developed for quantitative perfusion imaging and multi-contrast fMRI. The technique allows for clean separation between and thus simultaneous assessment of BOLD and perfusion effects, whereas quantitative cerebral blood flow (CBF) and tissue T(1) values are monitored online. Online CBF maps were obtained using the FAIREST technique and the measured CBF values were consistent with the off-line CBF maps obtained from using the FAIR technique in combination with a separate sequence for T(1) measurement. Finger tapping activation studies were carried out to demonstrate the applicability of the FAIREST technique in a typical fMRI setting for multi-contrast fMRI. The relative CBF and BOLD changes induced by finger-tapping were 75.1 +/- 18.3 and 1.8 +/- 0.4%, respectively, and the relative oxygen consumption rate change was 2.5 +/- 7.7%. The results from correlation of the T(1) maps with the activation images on a pixel-by-pixel basis show that the mean T(1) value of the CBF activation pixels is close to the T(1) of gray matter while the mean T(1) value of the BOLD activation pixels is close to the T(1) range of blood and cerebrospinal fluid.

  12. Elastic reverse-time migration based on amplitude-preserving P- and S-wave separation

    NASA Astrophysics Data System (ADS)

    Yang, Jia-Jia; Luan, Xi-Wu; Fang, Gang; Liu, Xin-Xin; Pan, Jun; Wang, Xiao-Jie

    2016-09-01

    Imaging the PP- and PS-wave for the elastic vector wave reverse-time migration requires separating the P- and S-waves during the wave field extrapolation. The amplitude and phase of the P- and S-waves are distorted when divergence and curl operators are used to separate the P- and S-waves. We present a P- and S-wave amplitude-preserving separation algorithm for the elastic wavefield extrapolation. First, we add the P-wave pressure and P-wave vibration velocity equation to the conventional elastic wave equation to decompose the P- and S-wave vectors. Then, we synthesize the scalar P- and S-wave from the vector Pand S-wave to obtain the scalar P- and S-wave. The amplitude-preserved separated P- and S-waves are imaged based on the vector wave reverse-time migration (RTM). This method ensures that the amplitude and phase of the separated P- and S-wave remain unchanged compared with the divergence and curl operators. In addition, after decomposition, the P-wave pressure and vibration velocity can be used to suppress the interlayer reflection noise and to correct the S-wave polarity. This improves the image quality of P- and S-wave in multicomponent seismic data and the true-amplitude elastic reverse time migration used in prestack inversion.

  13. Microfluidic device based on a micro-hydrocyclone for particle-liquid separation.

    PubMed

    Bhardwaj, P; Bagdi, P; Sen, A K

    2011-12-07

    This paper presents theoretical analysis, design, simulation, fabrication and test of a microfluidic device ('Micro-hydrocyclone') for separation of micron and submicron size solid particles from liquid in a particle liquid mixture. A theoretical analysis of the micro-hydrocyclone is performed to understand the physics and develop suitable design models. The structure of the proposed device is designed based on the Bradley model, as it offers lower cut-size thus making it suitable for microfluidics applications. The operational parameters are derived from the dimensional group model. The particle separation process inside the micro-hydrocyclone is simulated by solving fluid flows using Navier-Stokes equations and particle dynamics using a Lagrangian approach in a Eulerian fluid. The influence of inlet velocity and density on separation efficiency is investigated. The device is fabricated with SU-8 photoresist on a PMMA substrate using a combination of photolithography and micro-milling. Experiments are performed to demonstrate particle-liquid separation using polystyrene microbeads suspended in PBS as the feed sample. The influence of inlet velocity and particle size on particle separation efficiency is measured and compared with that obtained from simulations and a good match was found. The proposed device can be easily integrated with micro-environments thus it is suitable for lab-on-chip and microsystems development. The device may have applications in chemical analysis, materials research, point-of-care, blood sample preparation and other biomedical applications.

  14. Separate collection of household food waste for anaerobic degradation - Comparison of different techniques from a systems perspective

    SciTech Connect

    Bernstad, A.; Cour Jansen, J. la

    2012-05-15

    Highlight: Black-Right-Pointing-Pointer Four modern and innovative systems for household food waste collection are compared. Black-Right-Pointing-Pointer Direct emissions and resource use were based on full-scale data. Black-Right-Pointing-Pointer Conservation of nutrients/energy content over the system was considered. Black-Right-Pointing-Pointer Systems with high energy/nutrient recovery are most environmentally beneficial. - Abstract: Four systems for household food waste collection are compared in relation the environmental impact categories eutrophication potential, acidification potential, global warming potential as well as energy use. Also, a hotspot analysis is performed in order to suggest improvements in each of the compared collection systems. Separate collection of household food waste in paper bags (with and without drying prior to collection) with use of kitchen grinders and with use of vacuum system in kitchen sinks were compared. In all cases, food waste was used for anaerobic digestion with energy and nutrient recovery in all cases. Compared systems all resulted in net avoidance of assessed environmental impact categories; eutrophication potential (-0.1 to -2.4 kg NO{sub 3}{sup -}eq/ton food waste), acidification potential (-0.4 to -1.0 kg SO{sub 2}{sup -}eq/ton food waste), global warming potential (-790 to -960 kg CO{sub 2}{sup -}eq/ton food waste) and primary energy use (-1.7 to -3.6 GJ/ton food waste). Collection with vacuum system results in the largest net avoidance of primary energy use, while disposal of food waste in paper bags for decentralized drying before collection result in a larger net avoidance of global warming, eutrophication and acidification. However, both these systems not have been taken into use in large scale systems yet and further investigations are needed in order to confirm the outcomes from the comparison. Ranking of scenarios differ largely if considering only emissions in the foreground system, indicating the

  15. Comparison of laser-based rapid prototyping techniques

    NASA Astrophysics Data System (ADS)

    Humphreys, Hugh; Wimpenny, David

    2002-04-01

    A diverse range of Rapid Prototyping, or layer manufacturing techniques have evolved since the introduction of the first process in the late 1980s. Many, although not all, rapid prototyping processes rely on lasers to provide a localised and controllable source of light for curing a liquid photopolymer or heat to fuse thermoplastic powders to form objects. This paper will provide an overview of laser based rapid prototyping methods and discuss the future direction of this technology in light of the threats posed by low cost 3D printing techniques and the opportunity for the direct manufacture of metal components.

  16. Separating the Research Question from the Laboratory Techniques: Advancing High-School Biology Teachers' Ability to Ask Research Questions

    ERIC Educational Resources Information Center

    Hasson, Eilat; Yarden, Anat

    2012-01-01

    Inquiry is essentially a process in which research questions are asked and an attempt is made to find the answers. However, the formulation of operational research questions of the sort used in authentic scientific inquiry is not a trivial task. Here, we set out to explore the possible influence of separating the research question from the…

  17. Removal of High Concentration Chromium by a Foam-separating Technique Using Casein Proteins as a Foaming Reagent

    NASA Astrophysics Data System (ADS)

    Sugimoto, Futoshi

    Foam separation of high concentration chromium in leather tanning wastewater was investigated using casein protein as a foaming reagent5mL of5w/v% ammonium acetate buffer was added to the sample chromium water. After adjusting the pH to 9.0,4g/L concentrations of casein and gelatin solution were added to recovery the coagulating flocs of chromium resulting foam separation. The sample water containing chromium flocs was incased in reactor, then mixed with distilled water and 1mL of ethanol to sum 200mL total. The foam separation was performed at time intervals of 3min with an air flow rate of 300mL/min. With casein reagent, the removal rate of chromium was not influenced by the presence of NaCl, however, the rate decreased tendency using with the use of gelatin. The proposed method, utilizing 4g/L of casein solution with water, was not influenced by the presence of calcium (<34mM), magnesium (<1mM), carbonate (<0.5mM), bicarbonate (<1.2mM) nor sulfate (<350mM) ions, and is ideal for foam separation in chromium concentrations of about 100mgCr/L.

  18. A Preliminary Assessment of Phase Separator Ground-Based and Reduced-Gravity Testing for ALS Systems

    NASA Technical Reports Server (NTRS)

    Hall, Nancy Rabel

    2006-01-01

    A viewgraph presentation of phase separator ground-based and reduced-gravity testing for Advanced Life Support (ALS) systems is shown. The topics include: 1) Multiphase Flow Technology Program; 2) Types of Separators; 3) MOBI Phase Separators; 4) Experiment set-up; and 5) Preliminary comparison/results.

  19. Graphene-based terahertz photodetector by noise thermometry technique

    SciTech Connect

    Wang, Ming-Jye; Wang, Ji-Wun; Wang, Chun-Lun; Chiang, Yen-Yu; Chang, Hsian-Hong

    2014-01-20

    We report the characteristics of graphene-based terahertz (THz) photodetector based on noise thermometry technique by measuring its noise power at frequency from 4 to 6 GHz. Hot electron system in graphene microbridge is generated after THz photon pumping and creates extra noise power. The equivalent noise temperature and electron temperature increase rapidly in low THz pumping regime and saturate gradually in high THz power regime which is attributed to a faster energy relaxation process involved by stronger electron-phonon interaction. Based on this detector, a conversion efficiency around 0.15 from THz power to noise power in 4–6 GHz span has been achieved.

  20. Calculations of helium separation via uniform pores of stanene-based membranes

    PubMed Central

    Gao, Guoping; Jiao, Yan; Jiao, Yalong; Ma, Fengxian; Kou, Liangzhi

    2015-01-01

    Summary The development of low energy cost membranes to separate He from noble gas mixtures is highly desired. In this work, we studied He purification using recently experimentally realized, two-dimensional stanene (2D Sn) and decorated 2D Sn (SnH and SnF) honeycomb lattices by density functional theory calculations. To increase the permeability of noble gases through pristine 2D Sn at room temperature (298 K), two practical strategies (i.e., the application of strain and functionalization) are proposed. With their high concentration of large pores, 2D Sn-based membrane materials demonstrate excellent helium purification and can serve as a superior membrane over traditionally used, porous materials. In addition, the separation performance of these 2D Sn-based membrane materials can be significantly tuned by application of strain to optimize the He purification properties by taking both diffusion and selectivity into account. Our results are the first calculations of He separation in a defect-free honeycomb lattice, highlighting new interesting materials for helium separation for future experimental validation. PMID:26885459

  1. Complete chromogen separation and analysis in double immunohistochemical stains using Photoshop-based image analysis.

    PubMed

    Lehr, H A; van der Loos, C M; Teeling, P; Gown, A M

    1999-01-01

    Simultaneous detection of two different antigens on paraffin-embedded and frozen tissues can be accomplished by double immunohistochemistry. However, many double chromogen systems suffer from signal overlap, precluding definite signal quantification. To separate and quantitatively analyze the different chromogens, we imported images into a Macintosh computer using a CCD camera attached to a diagnostic microscope and used Photoshop software for the recognition, selection, and separation of colors. We show here that Photoshop-based image analysis allows complete separation of chromogens not only on the basis of their RGB spectral characteristics, but also on the basis of information concerning saturation, hue, and luminosity intrinsic to the digitized images. We demonstrate that Photoshop-based image analysis provides superior results compared to color separation using bandpass filters. Quantification of the individual chromogens is then provided by Photoshop using the Histogram command, which supplies information on the luminosity (corresponding to gray levels of black-and-white images) and on the number of pixels as a measure of spatial distribution. (J Histochem Cytochem 47:119-125, 1999)

  2. Optical center alignment technique based on inner profile measurement method

    NASA Astrophysics Data System (ADS)

    Wakayama, Toshitaka; Yoshizawa, Toru

    2014-05-01

    Center alignment is important technique to tune up the spindle of various precision machines in manufacturing industry. Conventionally such a tool as a dial indicator has been used to adjust and to position the axis by manual operations of a technical worker. However, it is not easy to precisely control its axis. In this paper, we developed the optical center alignment technique based on inner profile measurement using a ring beam device. In this case, the center position of the cylinder hole can be determined from circular profile detected by optical sectioning method using a ring beam device. In our trials, the resolution of the center position is proved less than 10 micrometers in extreme cases. This technique is available for practical applications in machine tool industry.

  3. Copyright protection scheme based on chaos and secret sharing techniques

    NASA Astrophysics Data System (ADS)

    Lou, Der-Chyuan; Shieh, Jieh-Ming; Tso, Hao-Kuan

    2005-11-01

    A copyright protection scheme based on chaos and secret sharing techniques is proposed. Instead of modifying the original image to embed a watermark in it, the proposed scheme extracts a feature from the image first. Then, the extracted feature and the watermark are scrambled by a chaos technique. Finally, the secret sharing technique is used to construct a shadow image. The watermark can be retrieved by performing an XOR operation between the shadow images. The proposed scheme has the following advantages. Firstly, the watermark retrieval does not need the original image. Secondly, the scheme does not need to modify the original image for embedding the watermark. Thirdly, compared with several schemes, the scheme is secure and robust in resisting various attacks.

  4. Fault diagnosis in gas turbines using a model-based technique

    NASA Astrophysics Data System (ADS)

    Merrington, G. L.

    1994-04-01

    Reliable methods for diagnosing faults and detecting degraded performance in gas turbine engines are continually being sought. In this paper, a model-based technique is applied to the problem of detecting degraded performance in a military turbofan engine from take-off acceleration-type transients. In the past, difficulty has been experienced in isolating the effects of some of the physical processes involved. One such effect is the influence of the bulk metal temperature on the measured engine parameters during large power excursions. It will be shown that the model-based technique provides a simple and convenient way of separating this effect from the faster dynamic components. The important conclusion from this work is that good fault coverage can be gleaned from the resultant pseudo-steady-state gain estimates derived in this way.

  5. MEMS-based power generation techniques for implantable biosensing applications.

    PubMed

    Lueke, Jonathan; Moussa, Walied A

    2011-01-01

    Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS)-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient.

  6. MEMS-Based Power Generation Techniques for Implantable Biosensing Applications

    PubMed Central

    Lueke, Jonathan; Moussa, Walied A.

    2011-01-01

    Implantable biosensing is attractive for both medical monitoring and diagnostic applications. It is possible to monitor phenomena such as physical loads on joints or implants, vital signs, or osseointegration in vivo and in real time. Microelectromechanical (MEMS)-based generation techniques can allow for the autonomous operation of implantable biosensors by generating electrical power to replace or supplement existing battery-based power systems. By supplementing existing battery-based power systems for implantable biosensors, the operational lifetime of the sensor is increased. In addition, the potential for a greater amount of available power allows additional components to be added to the biosensing module, such as computational and wireless and components, improving functionality and performance of the biosensor. Photovoltaic, thermovoltaic, micro fuel cell, electrostatic, electromagnetic, and piezoelectric based generation schemes are evaluated in this paper for applicability for implantable biosensing. MEMS-based generation techniques that harvest ambient energy, such as vibration, are much better suited for implantable biosensing applications than fuel-based approaches, producing up to milliwatts of electrical power. High power density MEMS-based approaches, such as piezoelectric and electromagnetic schemes, allow for supplemental and replacement power schemes for biosensing applications to improve device capabilities and performance. In addition, this may allow for the biosensor to be further miniaturized, reducing the need for relatively large batteries with respect to device size. This would cause the implanted biosensor to be less invasive, increasing the quality of care received by the patient. PMID:22319362

  7. New Flutter Analysis Technique for CFD-based Unsteady Aeroelasticity

    NASA Technical Reports Server (NTRS)

    Pak, Chan-gi; Jutte, Christine V.

    2009-01-01

    This paper presents a flutter analysis technique for the transonic flight regime. The technique uses an iterative approach to determine the critical dynamic pressure for a given mach number. Unlike other CFD-based flutter analysis methods, each iteration solves for the critical dynamic pressure and uses this value in subsequent iterations until the value converges. This process reduces the iterations required to determine the critical dynamic pressure. To improve the accuracy of the analysis, the technique employs a known structural model, leaving only the aerodynamic model as the unknown. The aerodynamic model is estimated using unsteady aeroelastic CFD analysis combined with a parameter estimation routine. The technique executes as follows. The known structural model is represented as a finite element model. Modal analysis determines the frequencies and mode shapes for the structural model. At a given mach number and dynamic pressure, the unsteady CFD analysis is performed. The output time history of the surface pressure is converted to a nodal aerodynamic force vector. The forces are then normalized by the given dynamic pressure. A multi-input multi-output parameter estimation software, ERA, estimates the aerodynamic model through the use of time histories of nodal aerodynamic forces and structural deformations. The critical dynamic pressure is then calculated using the known structural model and the estimated aerodynamic model. This output is used as the dynamic pressure in subsequent iterations until the critical dynamic pressure is determined. This technique is demonstrated on the Aerostructures Test Wing-2 model at NASA's Dryden Flight Research Center.

  8. Separation of large DNA molecules by size exclusion chromatography-based microchip with on-chip concentration structure

    NASA Astrophysics Data System (ADS)

    Azuma, Naoki; Itoh, Shintaro; Fukuzawa, Kenji; Zhang, Hedong

    2016-06-01

    The separation of DNA molecules according to their size represents a fundamental bioanalytical procedure. Here, we report the development of a chip-sized device, consisting of micrometer-sized fence structures fabricated in a microchannel, for the separation of large DNA molecules (over 10 kbp) based on the principle of size exclusion chromatography (SEC). In order to achieve separation, two approaches were utilized: first, the DNA samples were concentrated immediately prior to separation using nanoslit structures, with the aim of improving the resolution. Second, a theoretical model of SEC-based separation was established and applied in order to predict the optimal voltage range for separation. In this study, we achieved separation of λ DNA (48.5 kbp) and T4 DNA (166 kbp) using the present SEC-based microchip.

  9. Electrocardiogram signal denoising based on empirical mode decomposition technique: an overview

    NASA Astrophysics Data System (ADS)

    Han, G.; Lin, B.; Xu, Z.

    2017-03-01

    Electrocardiogram (ECG) signal is nonlinear and non-stationary weak signal which reflects whether the heart is functioning normally or abnormally. ECG signal is susceptible to various kinds of noises such as high/low frequency noises, powerline interference and baseline wander. Hence, the removal of noises from ECG signal becomes a vital link in the ECG signal processing and plays a significant role in the detection and diagnosis of heart diseases. The review will describe the recent developments of ECG signal denoising based on Empirical Mode Decomposition (EMD) technique including high frequency noise removal, powerline interference separation, baseline wander correction, the combining of EMD and Other Methods, EEMD technique. EMD technique is a quite potential and prospective but not perfect method in the application of processing nonlinear and non-stationary signal like ECG signal. The EMD combined with other algorithms is a good solution to improve the performance of noise cancellation. The pros and cons of EMD technique in ECG signal denoising are discussed in detail. Finally, the future work and challenges in ECG signal denoising based on EMD technique are clarified.

  10. Chiral derivatizations applied for the separation of unusual amino acid enantiomers by liquid chromatography and related techniques.

    PubMed

    Ilisz, István; Aranyi, Anita; Péter, Antal

    2013-06-28

    Amino acids are essential for life, and have many functions in metabolism. One particularly important function is to serve as the building blocks of peptides and proteins, giving rise complex three dimensional structures through disulfide bonds or crosslinked amino acids. Peptides are frequently cyclic and contain proteinogenic as well as nonproteinogenic amino acids in many instances. Since most of the proteinogenic α-amino acids contain at least one stereogenic center (with the exception of glycine), the stereoisomers of all these amino acids and the peptides in which they are to be found may possess differences in biological activity in living systems. The impetus for advances in chiral separation has been highest in the past 25 years and this still continues to be an area of high focus. The important analytical task of the separation of isomers is achieved mainly by chromatographic and electrophoretic methods. This paper reviews indirect separation approaches, i.e. derivatization reactions aimed at creating the basis for the chromatographic resolution of biologically and pharmaceutically important enantiomers of unusual amino acids and related compounds, with emphasis on the literature published from 1980s. The main aspects of the chiral derivatization of amino acids are discussed, i.e. derivatization on the amino group, transforming the molecules into covalently bonded diastereomeric derivatives through the use of homochiral derivatizing agents. The diastereomers formed (amides, urethanes, urea and thiourea derivatives, etc.) can be separated on achiral stationary phases. The applications are considered, and in some cases different derivatizing agents for the resolution of complex mixtures of proteinogenic d,l-amino acids, non-proteinogenic amino acids and peptides/amino acids from peptide syntheses or microorganisms are compared.

  11. TL and ESR based identification of gamma-irradiated frozen fish using different hydrolysis techniques

    NASA Astrophysics Data System (ADS)

    Ahn, Jae-Jun; Akram, Kashif; Shahbaz, Hafiz Muhammad; Kwon, Joong-Ho

    2014-12-01

    Frozen fish fillets (walleye Pollack and Japanese Spanish mackerel) were selected as samples for irradiation (0-10 kGy) detection trials using different hydrolysis methods. Photostimulated luminescence (PSL)-based screening analysis for gamma-irradiated frozen fillets showed low sensitivity due to limited silicate mineral contents on the samples. Same limitations were found in the thermoluminescence (TL) analysis on mineral samples isolated by density separation method. However, acid (HCl) and alkali (KOH) hydrolysis methods were effective in getting enough minerals to carry out TL analysis, which was reconfirmed through the normalization step by calculating the TL ratios (TL1/TL2). For improved electron spin resonance (ESR) analysis, alkali and enzyme (alcalase) hydrolysis methods were compared in separating minute-bone fractions. The enzymatic method provided more clear radiation-specific hydroxyapatite radicals than that of the alkaline method. Different hydrolysis methods could extend the application of TL and ESR techniques in identifying the irradiation history of frozen fish fillets.

  12. 81929 - Fission-Product Separation Based on Room - Temperature Ionic Liquids

    SciTech Connect

    Robin D. Rogers

    2004-12-09

    This project has demonstrated that Sr2+ and Cs+ can be selectively extracted from aqueous solutions into ionic liquids using crown ethers and that unprecedented large distribution coefficients can be achieved for these fission products. The volume of secondary wastes can be significantly minimized with this new separation technology. Through the current EMSP funding, the solvent extraction technology based on ionic liquids has been shown to be viable and can potentially provide the most efficient separation of problematic fission products from high level wastes. The key results from the current funding period are the development of highly selective extraction process for cesium ions based on crown ethers and calixarenes, optimization of selectivities of extractants via systematic change of ionic liquids, and investigation of task-specific ionic liquids incorporating both complexant and solvent characteristics.

  13. Gabor-based fusion technique for Optical Coherence Microscopy.

    PubMed

    Rolland, Jannick P; Meemon, Panomsak; Murali, Supraja; Thompson, Kevin P; Lee, Kye-sung

    2010-02-15

    We recently reported on an Optical Coherence Microscopy technique, whose innovation intrinsically builds on a recently reported - 2 microm invariant lateral resolution by design throughout a 2 mm cubic full-field of view - liquid-lens-based dynamic focusing optical probe [Murali et al., Optics Letters 34, 145-147, 2009]. We shall report in this paper on the image acquisition enabled by this optical probe when combined with an automatic data fusion method developed and described here to produce an in-focus high resolution image throughout the imaging depth of the sample. An African frog tadpole (Xenopus laevis) was imaged with the novel probe and the Gabor-based fusion technique, demonstrating subcellular resolution in a 0.5 mm (lateral) x 0.5 mm (axial) without the need, for the first time, for x-y translation stages, depth scanning, high-cost adaptive optics, or manual intervention. In vivo images of human skin are also presented.

  14. Polymer-based separations: Synthesis and application of polymers for ionic and molecular recognition

    SciTech Connect

    Alexandratos, S.D.

    1992-01-01

    Polymer-based separations have utilized resins such as sulfonic, acrylic, and iminodiacetic acid resins and the XAD series. Selective polymeric reagents for reaction with a targeted metal ion were synthesized as polymers with two different types of functional groups, each operating on the ions through a different mechanism. There are 3 classes of DMBPs (dual mechanism bifunctional polymers). Research during this period dealing with metal ion recognition focused on two of these classes (reduction of metal ions to metal; selective complexation).

  15. Method and apparatus for separating gases based on electrically and magnetically enhanced monolithic carbon fiber composite sorbents

    DOEpatents

    Judkins, R.R.; Burchell, T.D.

    1999-07-20

    A method for separating gases or other fluids involves placing a magnetic field on a monolithic carbon fiber composite sorption material to more preferentially attract certain gases or other fluids to the sorption material to which a magnetic field is applied. This technique may be combined with the known pressure swing adsorption'' technique utilizing the same sorption material. 1 fig.

  16. Method and apparatus for separating gases based on electrically and magnetically enhanced monolithic carbon fiber composite sorbents

    DOEpatents

    Judkins, Roddie R.; Burchell, Timothy D.

    1999-01-01

    A method for separating gases or other fluids involves placing a magnetic field on a monolithic carbon fiber composite sorption material to more preferentially attract certain gases or other fluids to the sorption material to which a magnetic field is applied. This technique may be combined with the known "pressure swing adsorption" technique utilizing the same sorption material.

  17. New Combined Object-Based Technique for Efficient Urban Classsification Using WORLDVIEW-2 Data

    NASA Astrophysics Data System (ADS)

    Elsharkawy, A.; Elhabiby, M.; El-Sheimy, N.

    2012-07-01

    The new advances of having eight bands satellite mission similar to WorldView-2, WV-2, give the chance to address and solve some of the traditional problems related to the low spatial and/or spectral resolution; such as the lack of details for certain features or the inability of the conventional classifiers to detect some land-cover types because of missing efficient spectrum information and analysis techniques. High-resolution imagery is particularly well suited to urban applications. High spectral and spatial resolution of WorldView-2 data introduces challenges in detailed mapping of urban features. Classification of Water, Shadows, Red roofs and concrete buildings spectrally exhibit significant confusion either from the high similarity in the spectral response (e.g. water and Shadows) or the similarity in material type (e.g. red roofs and concrete buildings). This research study assesses the enhancement of the classification accuracy and efficiency for a data set of WorldView-2 satellite imagery using the full 8-bands through integrating the output of classification process using three band ratios with another step involves an object-based technique for extracting shadows, water, vegetation, building, Bare soil and asphalt roads. Second generation curvelet transform will be used in the second step, specifically to detect buildings' boundaries, which will aid the new algorithm of band ratios classification through efficient separation of the buildings. The combined technique is tested, and the preliminary results show a great potential of the new bands in the WV-2 imagery in the separation between confusing classes such as water and shadows, and the testing is extended to the separation between bare soils and asphalt roads. The Integrated band ratio-curvelet transform edge detection techniques increased the percentage of building detection by more than 30%.

  18. Optimization design of satellite separation systems based on Multi-Island Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Hu, Xingzhi; Chen, Xiaoqian; Zhao, Yong; Yao, Wen

    2014-03-01

    The separation systems are crucial for the launch of satellites. With respect to the existing design issues of satellite separation systems, an optimization design approach based on Multi-Island Genetic Algorithm is proposed, and a hierarchical optimization of system mass and separation angular velocity is designed. Multi-Island Genetic Algorithm is studied for the problem and the optimization parameters are discussed. Dynamic analysis of ADAMS used to validate the designs is integrated with iSIGHT. Then the optimization method is employed for a typical problem using the helical compression spring mechanism, and the corresponding objective functions are derived. It turns out that the mass of compression spring catapult is decreased by 30.7% after optimization and the angular velocity can be minimized considering spring stiffness errors. Moreover, ground tests and on-orbit flight indicate that the error of separation speed is controlled within 1% and the angular velocity is reduced by nearly 90%, which proves the design result and the optimization approach.

  19. Domestic wash water reclamation for reuse as commode water supply using filtration: Reverse-osmosis separation technique

    NASA Technical Reports Server (NTRS)

    Hall, J. B., Jr.; Batten, C. E.; Wilkins, J. R.

    1974-01-01

    A combined filtration-reverse-osmosis water recovery system has been evaluated to determine its capability to reclaim domestic wash water for reuse as a commode water supply. The system produced water that met all chemical and physical requirements established by the U.S. Public Health Service for drinking water with the exception of carbon chloroform extractables, methylene blue active substances, and phenols. It is thought that this water is of sufficient quality to be reused as commode supply water. The feasibility of using a combined filtration and reverse-osmosis technique for reclaiming domestic wash water has been established. The use of such a technique for wash-water recovery will require a maintenance filter to remove solid materials including those less than 1 micron in size from the wash water. The reverse-osmosis module, if sufficiently protected from plugging, is an attractive low-energy technique for removing contaminants from domestic wash water.

  20. Capillary Separation: Micellar Electrokinetic Chromatography

    NASA Astrophysics Data System (ADS)

    Terabe, Shigeru

    2009-07-01

    Micellar electrokinetic chromatography (MEKC), a separation mode of capillary electrophoresis (CE), has enabled the separation of electrically neutral analytes. MEKC can be performed by adding an ionic micelle to the running solution of CE without modifying the instrument. Its separation principle is based on the differential migration of the ionic micelles and the bulk running buffer under electrophoresis conditions and on the interaction between the analyte and the micelle. Hence, MEKC's separation principle is similar to that of chromatography. MEKC is a useful technique particularly for the separation of small molecules, both neutral and charged, and yields high-efficiency separation in a short time with minimum amounts of sample and reagents. To improve the concentration sensitivity of detection, several on-line sample preconcentration techniques such as sweeping have been developed.

  1. A Different Web-Based Geocoding Service Using Fuzzy Techniques

    NASA Astrophysics Data System (ADS)

    Pahlavani, P.; Abbaspour, R. A.; Zare Zadiny, A.

    2015-12-01

    Geocoding - the process of finding position based on descriptive data such as address or postal code - is considered as one of the most commonly used spatial analyses. Many online map providers such as Google Maps, Bing Maps and Yahoo Maps present geocoding as one of their basic capabilities. Despite the diversity of geocoding services, users usually face some limitations when they use available online geocoding services. In existing geocoding services, proximity and nearness concept is not modelled appropriately as well as these services search address only by address matching based on descriptive data. In addition there are also some limitations in display searching results. Resolving these limitations can enhance efficiency of the existing geocoding services. This paper proposes the idea of integrating fuzzy technique with geocoding process to resolve these limitations. In order to implement the proposed method, a web-based system is designed. In proposed method, nearness to places is defined by fuzzy membership functions and multiple fuzzy distance maps are created. Then these fuzzy distance maps are integrated using fuzzy overlay technique for obtain the results. Proposed methods provides different capabilities for users such as ability to search multi-part addresses, searching places based on their location, non-point representation of results as well as displaying search results based on their priority.

  2. Surgical technique for repair of complex anterior skull base defects

    PubMed Central

    Reinard, Kevin; Basheer, Azam; Jones, Lamont; Standring, Robert; Lee, Ian; Rock, Jack

    2015-01-01

    Background: Modern microsurgical techniques enable en bloc resection of complex skull base tumors. Anterior cranial base surgery, particularly, has been associated with a high rate of postoperative cerebrospinal fluid (CSF) leak, meningitis, intracranial abscess, and pneumocephalus. We introduce simple modifications to already existing surgical strategies designed to minimize the incidence of postoperative CSF leak and associated morbidity and mortality. Methods: Medical records from 1995 to 2013 were reviewed in accordance with the Institutional Review Board. We identified 21 patients who underwent operations for repair of large anterior skull base defects following removal of sinonasal or intracranial pathology using standard craniofacial procedures. Patient charts were screened for CSF leak, meningitis, or intracranial abscess formation. Results: A total of 15 male and 6 female patients with an age range of 26–89 years were included. All patients were managed with the same operative technique for reconstruction of the frontal dura and skull base defect. Spinal drainage was used intraoperatively in all cases but the lumbar drain was removed at the end of each case in all patients. Only one patient required re-operation for repair of persistent CSF leak. None of the patients developed meningitis or intracranial abscess. There were no perioperative mortalities. Median follow-up was 10 months. Conclusion: The layered reconstruction of large anterior cranial fossa defects resulted in postoperative CSF leak in only 5% of the patients and represents a simple and effective closure option for skull base surgeons. PMID:25722926

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

    PubMed Central

    Kang, Wei; Cannon, Jennifer L.

    2015-01-01

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

  4. Sequence-based separation of single-stranded DNA using nucleotides in capillary electrophoresis: focus on phosphate.

    PubMed

    Zhang, Xueru; McGown, Linda B

    2013-06-01

    DNA analysis has widespread applicability in biology, medicine, biotechnology, and forensics. DNA separation by length is readily achieved using sieving gels in electrophoresis. Separation by sequence is less simple, generally requiring adequate differences in native or induced conformation or differences in thermal or chemical stability of the strands that are hybridized prior to measurement. We previously demonstrated separation of four single-stranded DNA 76-mers that differ by only a few A-G substitutions based solely on sequence using guanosine-5'-monophosphate (GMP) in the running buffer. We attributed separation to the unique self-assembly of GMP to form higher order structures. Here, we examine an expanded set of 76-mers designed to probe the mechanism of the separation and effects of experimental conditions. We were surprised to find that other ribonucleotides achieved the similar separation to GMP, and that some separation was achieved using sodium phosphate instead of GMP. Potassium phosphate achieved almost as good separations as the ribonucleotides. This suggests that the separation medium provides a physicochemical environment for the DNA that effects strand migration in a sequence-selective manner. Further investigation is needed to determine whether the mechanism involves specific interactions between the phosphates and the DNA strands or is a result of other properties of the separation medium. Phosphate generally has been avoided in DNA separations by capillary gel electrophoresis because its high ionic strength exacerbates Joule heating. Our results suggest that phosphate compounds should be examined for separation of DNA based on sequence.

  5. Separation of epidermal cells by density centrifugation: a new technique for studies on normal and pathological differentiation.

    PubMed

    Fischer, S M; Nelson, K D; Reiners, J J; Viaje, A; Pelling, J C; Slaga, T J

    1982-02-01

    Murine keratinocytes, isolated by flotation trypsinization of skin, can be separated into five groups by centrifugation through Percoll, a colloidal silica gradient. Within each group a good correlation was found between density, plating efficiency, morphological appearance, DNA synthesis, and degree of keratinization/cornification. This method can be applied equally well to fetal, newborn, or adult keratinocytes and should be useful in a variety of studies including isolation of subpopulations of pathological cell types, work on chalones and hyperplastic diseases such as psoriasis, and in vitro transformation studies.

  6. X-Ray microanalytical techniques based on synchrotron radiation.

    PubMed

    Snigireva, Irina; Snigirev, Anatoly

    2006-01-01

    The development of 3rd generation synchrotron radiation sources like European Synchrotron Radiation Facility (ESRF) in parallel with recent advances in the technology of X-ray microfocusing elements like Kirkpatrick-Baez (KB) mirrors, diffractive (Fresnel zone plates, FZP) and refractive (compound refractive lenses, CRL) optics, makes it possible to use X-ray microscopy techniques with high energy X-rays (energy superior to 4 keV). Spectroscopy, imaging, tomography and diffraction studies of samples with hard X-rays at micrometre and sub-micrometre spatial resolutions are now possible. The concept of combining these techniques as a high-energy microscopy has been proposed and successfully realized at the ESRF beamlines. Therefore a short summary of X-ray microscopy techniques is presented first. The main emphasis will be put on those methods which aim to produce sub-micron and nanometre resolution. These methods fall into three broad categories: reflective, refractive and diffractive optics. The basic principles and recent achievements will be discussed for all optical devices. Recent applications of synchrotron based microanalytical techniques to characterise radioactive fuel particles (UO(2)) released from the Chernobyl reactor are reported.

  7. Introducing Students to Protein Analysis Techniques: Separation and Comparative Analysis of Gluten Proteins in Various Wheat Strains

    ERIC Educational Resources Information Center

    Pirinelli, Alyssa L.; Trinidad, Jonathan C.; Pohl, Nicola L. B.

    2016-01-01

    Polyacrylamide gel electrophoresis (PAGE) is commonly taught in undergraduate laboratory classes as a traditional method to analyze proteins. An experiment has been developed to teach these basic protein gel skills in the context of gluten protein isolation from various types of wheat flour. A further goal is to relate this technique to current…

  8. Membrane-based sample preparation for ion chromatography-Techniques, instrumental configurations and applications.

    PubMed

    Frenzel, Wolfgang; Markeviciute, Inga

    2017-01-06

    Sample preparation is the bottleneck of many analytical methods, including ion chromatography (IC). Procedures based on the application of membranes are important, yet not well appreciated means for clean-up and analyte preconcentration of liquid samples. Filtration, ultrafiltration, the variety of dialysis techniques, i.e. passive dialysis, Donnan dialysis and electrodialysis, as well as gas-diffusion are being reviewed here with respect to their application in combination with IC. Instrumental aspects including hardware requirements, configuration of membrane separation units and membrane characteristics are presented. Operation in batch and flow-through mode is described with emphasis on the latter to in-line coupling with IC, permitting fully automated operation. Attention is also drawn to dialysis probes and microdialysis both providing options for in-situ measurements with inherent selective sampling of analytes and sample preparation. The respective features of the various techniques are outlined with respect to the possibilities of matrix removal and selectivity enhancement. In this article, we provide examples of application of the diverse membrane separation techniques and discuss the benefits and limitations thereof.

  9. Synergistic extraction and separation of Co(II)/Ni(II) by solvent extraction technique using TIOA/TOPO as carriers

    NASA Astrophysics Data System (ADS)

    Okatan, Ahmet; Eyüpoǧlu, Volkan; Kumbasar, Recep Ali; Turgut, Halil Ibrahim

    2016-04-01

    Cobalt and its compounds have wide range applications in some industrial and technological fields. These metals show excellent resistance to oxidation and corrosion under extreme conditions. However, these metals found together within metal ores in nature. This situation makes their separation difficult from each other. They have very similar physical and chemical properties making them very hard to be purified with using traditional separation pathways. Moreover, increasing supply-demand gap between them and decreasing valuable ores because of limited deposit in earth crust have been limited the sources of them. Under the light of this knowledge, one of the practical solutions should be produced to recycle cobalt and nickel from solid and liquid waste containing trace amounts of them. In this study, we investigated the selective and the synergistic cobalt extraction from acidic aqueous solutions by solvent extraction using tri-iso-octylamine (TIOA) and Tri-n-octyl phosphine oxide (TOPO) as carriers. The effective parameters on the extraction and the stripping of the cobalt were investigated, and optimum synergistic extraction and stripping conditions were identified. The cobalt extraction from aqueous Co/Ni solutions in various molar concentrations was examined in the optimum conditions to determine the synergism between TIOA and TOPO.

  10. Noninvasive in vivo glucose sensing using an iris based technique

    NASA Astrophysics Data System (ADS)

    Webb, Anthony J.; Cameron, Brent D.

    2011-03-01

    Physiological glucose monitoring is important aspect in the treatment of individuals afflicted with diabetes mellitus. Although invasive techniques for glucose monitoring are widely available, it would be very beneficial to make such measurements in a noninvasive manner. In this study, a New Zealand White (NZW) rabbit animal model was utilized to evaluate a developed iris-based imaging technique for the in vivo measurement of physiological glucose concentration. The animals were anesthetized with isoflurane and an insulin/dextrose protocol was used to control blood glucose concentration. To further help restrict eye movement, a developed ocular fixation device was used. During the experimental time frame, near infrared illuminated iris images were acquired along with corresponding discrete blood glucose measurements taken with a handheld glucometer. Calibration was performed using an image based Partial Least Squares (PLS) technique. Independent validation was also performed to assess model performance along with Clarke Error Grid Analysis (CEGA). Initial validation results were promising and show that a high percentage of the predicted glucose concentrations are within 20% of the reference values.

  11. Apprenticeship learning techniques for knowledge-based systems

    SciTech Connect

    Wilkins, D.C.

    1987-01-01

    This thesis describes apprenticeship learning techniques for automation of the transfer of expertise. Apprenticeship learning is a form of learning by watching, in which learning occurs as a byproduct of building explanations of human problem-solving actions. As apprenticeship is the most-powerful method that human experts use to refine and debug their expertise in knowledge-intensive domains such as medicine; this motivates giving such capabilities to an expert system. The major accomplishment in this thesis is showing how an explicit representation of the strategy knowledge to solve a general problem class, such as diagnosis, can provide a basis for learning the knowledge that is specific to a particular domain, such as medicine. The Odysseus learning program provides the first demonstration of using the same technique to transfer of expertise to and from an expert system knowledge base. Another major focus of this thesis is limitations of apprenticeship learning. It is shown that extant techniques for reasoning under uncertainty for expert systems lead to a sociopathic knowledge base.

  12. Rapid and Efficient Filtration-Based Procedure for Separation and Safe Analysis of CBRN Mixed Samples

    PubMed Central

    Bentahir, Mostafa; Laduron, Frederic; Irenge, Leonid; Ambroise, Jérôme; Gala, Jean-Luc

    2014-01-01

    Separating CBRN mixed samples that contain both chemical and biological warfare agents (CB mixed sample) in liquid and solid matrices remains a very challenging issue. Parameters were set up to assess the performance of a simple filtration-based method first optimized on separate C- and B-agents, and then assessed on a model of CB mixed sample. In this model, MS2 bacteriophage, Autographa californica nuclear polyhedrosis baculovirus (AcNPV), Bacillus atrophaeus and Bacillus subtilis spores were used as biological agent simulants whereas ethyl methylphosphonic acid (EMPA) and pinacolyl methylphophonic acid (PMPA) were used as VX and soman (GD) nerve agent surrogates, respectively. Nanoseparation centrifugal devices with various pore size cut-off (30 kD up to 0.45 µm) and three RNA extraction methods (Invisorb, EZ1 and Nuclisens) were compared. RNA (MS2) and DNA (AcNPV) quantification was carried out by means of specific and sensitive quantitative real-time PCRs (qPCR). Liquid chromatography coupled to time-of-flight mass spectrometry (LC/TOFMS) methods was used for quantifying EMPA and PMPA. Culture methods and qPCR demonstrated that membranes with a 30 kD cut-off retain more than 99.99% of biological agents (MS2, AcNPV, Bacillus Atrophaeus and Bacillus subtilis spores) tested separately. A rapid and reliable separation of CB mixed sample models (MS2/PEG-400 and MS2/EMPA/PMPA) contained in simple liquid or complex matrices such as sand and soil was also successfully achieved on a 30 kD filter with more than 99.99% retention of MS2 on the filter membrane, and up to 99% of PEG-400, EMPA and PMPA recovery in the filtrate. The whole separation process turnaround-time (TAT) was less than 10 minutes. The filtration method appears to be rapid, versatile and extremely efficient. The separation method developed in this work constitutes therefore a useful model for further evaluating and comparing additional separation alternative procedures for a safe handling and

  13. Rapid and efficient filtration-based procedure for separation and safe analysis of CBRN mixed samples.

    PubMed

    Bentahir, Mostafa; Laduron, Frederic; Irenge, Leonid; Ambroise, Jérôme; Gala, Jean-Luc

    2014-01-01

    Separating CBRN mixed samples that contain both chemical and biological warfare agents (CB mixed sample) in liquid and solid matrices remains a very challenging issue. Parameters were set up to assess the performance of a simple filtration-based method first optimized on separate C- and B-agents, and then assessed on a model of CB mixed sample. In this model, MS2 bacteriophage, Autographa californica nuclear polyhedrosis baculovirus (AcNPV), Bacillus atrophaeus and Bacillus subtilis spores were used as biological agent simulants whereas ethyl methylphosphonic acid (EMPA) and pinacolyl methylphophonic acid (PMPA) were used as VX and soman (GD) nerve agent surrogates, respectively. Nanoseparation centrifugal devices with various pore size cut-off (30 kD up to 0.45 µm) and three RNA extraction methods (Invisorb, EZ1 and Nuclisens) were compared. RNA (MS2) and DNA (AcNPV) quantification was carried out by means of specific and sensitive quantitative real-time PCRs (qPCR). Liquid chromatography coupled to time-of-flight mass spectrometry (LC/TOFMS) methods was used for quantifying EMPA and PMPA. Culture methods and qPCR demonstrated that membranes with a 30 kD cut-off retain more than 99.99% of biological agents (MS2, AcNPV, Bacillus Atrophaeus and Bacillus subtilis spores) tested separately. A rapid and reliable separation of CB mixed sample models (MS2/PEG-400 and MS2/EMPA/PMPA) contained in simple liquid or complex matrices such as sand and soil was also successfully achieved on a 30 kD filter with more than 99.99% retention of MS2 on the filter membrane, and up to 99% of PEG-400, EMPA and PMPA recovery in the filtrate. The whole separation process turnaround-time (TAT) was less than 10 minutes. The filtration method appears to be rapid, versatile and extremely efficient. The separation method developed in this work constitutes therefore a useful model for further evaluating and comparing additional separation alternative procedures for a safe handling and

  14. Functional Allocation for Ground-Based Automated Separation Assurance in NextGen

    NASA Technical Reports Server (NTRS)

    Prevot, Thomas; Mercer, Joey; Martin, Lynne; Homola, Jeffrey; Cabrall, Christopher; Brasil, Connie

    2010-01-01

    As part of an ongoing research effort into functional allocation in a NextGen environment, a controller-in-the-loop study on ground-based automated separation assurance was conducted at NASA Ames' Airspace Operations Laboratory in February 2010. Participants included six FAA front line managers, who are currently certified professional controllers and four recently retired controllers. Traffic scenarios were 15 and 30 minutes long where controllers interacted with advanced technologies for ground-based separation assurance, weather avoidance, and arrival metering. The automation managed the separation by resolving conflicts automatically and involved controllers only by exception, e.g., when the automated resolution would have been outside preset limits. Results from data analyses show that workload was low despite high levels of traffic, Operational Errors did occur but were closely tied to local complexity, and safety acceptability ratings varied with traffic levels. Positive feedback was elicited for the overall concept with discussion on the proper allocation of functions and trust in automation.

  15. Separation of purine and pyrimidine bases and nucleosides by hydrophilic interaction chromatography.

    PubMed

    Marrubini, Giorgio; Mendoza, Bolivar Enrique Castillo; Massolini, Gabriella

    2010-03-01

    The separation of 12 model compounds chosen among purine and pyrimidine bases and nucleosides was studied by using hydrophilic interaction chromatography (HILIC). The compounds investigated were small molecules with relevant properties for biomedical and pharmaceutical studies. The mixture of pyrimidines and purines was applied on a ZIC-HILIC 150 x 2.1 mm, 5 microm, and two TSKgel Amide-80 150 x 2.0 mm, 5 microm and 3 microm particle size columns. The retention of the analytes was studied by varying ACN%, ammonium formate concentration, pH, and column temperature. The results obtained confirmed the elution order of nucleobases, nucleosides, and nucleotides based on their hydrophobicity. The retention mechanism of the columns was studied considering the models used for describing partitioning and surface adsorption. The influence on retention of chromatographic conditions (ACN%, salt concentration, pH, and temperature) was described and discussed for both columns. The optimization of the conditions studied allowed to assess a gradient method for the separation of the 12 analytes. The developed method is a valuable alternative to existing methods for the separation of the compounds concerned.

  16. Feature-based attentional modulation increases with stimulus separation in divided-attention tasks.

    PubMed

    Sally, Sharon L; Vidnyánsky, Zoltán; Papathomas, Thomas V

    2009-01-01

    Attention modifies our visual experience by selecting certain aspects of a scene for further processing. It is therefore important to understand factors that govern the deployment of selective attention over the visual field. Both location and feature-specific mechanisms of attention have been identified and their modulatory effects can interact at a neural level (Treue and Martinez-Trujillo, 1999). The effects of spatial parameters on feature-based attentional modulation were examined for the feature dimensions of orientation, motion and color using three divided-attention tasks. Subjects performed concurrent discriminations of two briefly presented targets (Gabor patches) to the left and right of a central fixation point at eccentricities of +/-2.5 degrees , 5 degrees , 10 degrees and 15 degrees in the horizontal plane. Gabors were size-scaled to maintain consistent single-task performance across eccentricities. For all feature dimensions, the data show a linear increase in the attentional effects with target separation. In a control experiment, Gabors were presented on an isoeccentric viewing arc at 10 degrees and 15 degrees at the closest spatial separation (+/-2.5 degrees ) of the main experiment. Under these conditions, the effects of feature-based attentional effects were largely eliminated. Our results are consistent with the hypothesis that feature-based attention prioritizes the processing of attended features. Feature-based attentional mechanisms may have helped direct the attentional focus to the appropriate target locations at greater separations, whereas similar assistance may not have been necessary at closer target spacings. The results of the present study specify conditions under which dual-task performance benefits from sharing similar target features and may therefore help elucidate the processes by which feature-based attention operates.

  17. Blind source separation based x-ray image denoising from an image sequence.

    PubMed

    Yu, Chun-Yu; Li, Yan; Fei, Bin; Li, Wei-Liang

    2015-09-01

    Blind source separation (BSS) based x-ray image denoising from an image sequence is proposed. Without priori knowledge, the useful image signal can be separated from an x-ray image sequence, for original images are supposed as different combinations of stable image signal and random image noise. The BSS algorithms such as fixed-point independent component analysis and second-order statistics singular value decomposition are used and compared with multi-frame averaging which is a common algorithm for improving image's signal-to-noise ratio (SNR). Denoising performance is evaluated in SNR, standard deviation, entropy, and runtime. Analysis indicates that BSS is applicable to image denoising; the denoised image's quality will get better when more frames are included in an x-ray image sequence, but it will cost more time; there should be trade-off between denoising performance and runtime, which means that the number of frames included in an image sequence is enough.

  18. Highly accurate and fast optical penetration-based silkworm gender separation system

    NASA Astrophysics Data System (ADS)

    Kamtongdee, Chakkrit; Sumriddetchkajorn, Sarun; Chanhorm, Sataporn

    2015-07-01

    Based on our research work in the last five years, this paper highlights our innovative optical sensing system that can identify and separate silkworm gender highly suitable for sericulture industry. The key idea relies on our proposed optical penetration concepts and once combined with simple image processing operations leads to high accuracy in identifying of silkworm gender. Inside the system, there are electronic and mechanical parts that assist in controlling the overall system operation, processing the optical signal, and separating the female from male silkworm pupae. With current system performance, we achieve a very highly accurate more than 95% in identifying gender of silkworm pupae with an average system operational speed of 30 silkworm pupae/minute. Three of our systems are already in operation at Thailand's Queen Sirikit Sericulture Centers.

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

    DOEpatents

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

    2001-01-01

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

  20. New modulation-based watermarking technique for video

    NASA Astrophysics Data System (ADS)

    Lemma, Aweke; van der Veen, Michiel; Celik, Mehmet

    2006-02-01

    Successful watermarking algorithms have already been developed for various applications ranging from meta-data tagging to forensic tracking. Nevertheless, it is commendable to develop alternative watermarking techniques that provide a broader basis for meeting emerging services, usage models and security threats. To this end, we propose a new multiplicative watermarking technique for video, which is based on the principles of our successful MASK audio watermark. Audio-MASK has embedded the watermark by modulating the short-time envelope of the audio signal and performed detection using a simple envelope detector followed by a SPOMF (symmetrical phase-only matched filter). Video-MASK takes a similar approach and modulates the image luminance envelope. In addition, it incorporates a simple model to account for the luminance sensitivity of the HVS (human visual system). Preliminary tests show algorithms transparency and robustness to lossy compression.

  1. Simultaneous determination of iron (II) and ascorbic acid in pharmaceuticas based on flow sandwich technique.

    PubMed

    Vakh, Christina; Freze, Elena; Pochivalov, Alexsey; Evdokimova, Ekaterina; Kamencev, Mihail; Moskvin, Leonid; Bulatov, Andrey

    2015-01-01

    The simple and easy performed flow system based on sandwich technique has been developed for the simultaneous separate determination of iron (II) and ascorbic acid in pharmaceuticals. The implementation of sandwich technique assumed the injection of sample solution between two selective reagents and allowed the carrying out in reaction coil two chemical reactions simultaneously: iron (II) with 1,10-phenanthroline and ascorbic acid with sodium 2,6-dichlorophenolindophenol. For achieving of excellent repeatability and considerable reagent saving the various parameters such as flow rate, sample and reagent volumes, reaction coil length were also optimized. The limits of detection (LODs) obtained by using the developed flow sandwich-type approach were 0.2 mg L(-1) for iron (II) and 0.7 mg L(-1) for ascorbic acid. The suggested approach was validated according to the following parameters: linearity and sensitivity, precision, recoveries and accuracy. The sampling frequency was 41 h(-1).

  2. An acoustic-array based structural health monitoring technique for wind turbine blades

    NASA Astrophysics Data System (ADS)

    Aizawa, Kai; Poozesh, Peyman; Niezrecki, Christopher; Baqersad, Javad; Inalpolat, Murat; Heilmann, Gunnar

    2015-04-01

    This paper proposes a non-contact measurement technique for health monitoring of wind turbine blades using acoustic beamforming techniques. The technique works by mounting an audio speaker inside a wind turbine blade and observing the sound radiated from the blade to identify damage within the structure. The main hypothesis for the structural damage detection is that the structural damage (cracks, edge splits, holes etc.) on the surface of a composite wind turbine blade results in changes in the sound radiation characteristics of the structure. Preliminary measurements were carried out on two separate test specimens, namely a composite box and a section of a wind turbine blade to validate the methodology. The rectangular shaped composite box and the turbine blade contained holes with different dimensions and line cracks. An acoustic microphone array with 62 microphones was used to measure the sound radiation from both structures when the speaker was located inside the box and also inside the blade segment. A phased array beamforming technique and CLEAN-based subtraction of point spread function from a reference (CLSPR) were employed to locate the different damage types on both the composite box and the wind turbine blade. The same experiment was repeated by using a commercially available 48-channel acoustic ring array to compare the test results. It was shown that both the acoustic beamforming and the CLSPR techniques can be used to identify the damage in the test structures with sufficiently high fidelity.

  3. Charge-based separation of particles and cells with similar sizes via the wall-induced electrical lift.

    PubMed

    Thomas, Cory; Lu, Xinyu; Todd, Andrew; Raval, Yash; Tzeng, Tzuen-Rong; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

    2017-01-01

    The separation of particles and cells in a uniform mixture has been extensively studied as a necessity in many chemical and biomedical engineering and research fields. This work demonstrates a continuous charge-based separation of fluorescent and plain spherical polystyrene particles with comparable sizes in a ψ-shaped microchannel via the wall-induced electrical lift. The effects of both the direct current electric field in the main-branch and the electric field ratio in between the inlet branches for sheath fluid and particle mixture are investigated on this electrokinetic particle separation. A Lagrangian tracking method based theoretical model is also developed to understand the particle transport in the microchannel and simulate the parametric effects on particle separation. Moreover, the demonstrated charge-based separation is applied to a mixture of yeast cells and polystyrene particles with similar sizes. Good separation efficiency and purity are achieved for both the cells and the particles.

  4. Investigation of liquid and gas chromatography techniques for separation of diastereomers of beta-(alpha-methylbenzyl) amino isobutyric acid.

    PubMed

    Held, Charles B; Robbins, David K

    2003-09-01

    Cryptophycins are macrolides investigated as potential anticancer agents. These large cyclic molecules are generated via a convergent process, utilizing the coupling of several smaller fragments synthesized individually. During early synthetic development of the beta-amino acid fragment C, analytical methods are necessary for the characterization of products resulting from the various routes being studied. One route being evaluated produces (RR) and (RS) diastereomers of beta-(alpha-methylbenzyl) amino isobutyric acid as intermediates. To measure diastereomeric excess (%de), assay conditions using high-performance liquid chromatography (HPLC) and capillary gas chromatographic (GC) techniques are explored. Derivatization methods using trifluoroacetyl- and silyl-derivatives are investigated for use with capillary GC. The results of the GC investigations are found to be only partially successful. Ion-pair HPLC is determined to be the optimal technique, utilizing pentanesulfonic acid as the counter ion to the amine group of beta-(alpha-methylbenzyl) amino isobutyric acid.

  5. Vision based techniques for rotorcraft low altitude flight

    NASA Technical Reports Server (NTRS)

    Sridhar, Banavar; Suorsa, Ray; Smith, Philip

    1991-01-01

    An overview of research in obstacle detection at NASA Ames Research Center is presented. The research applies techniques from computer vision to automation of rotorcraft navigation. The development of a methodology for detecting the range to obstacles based on the maximum utilization of passive sensors is emphasized. The development of a flight and image data base for verification of vision-based algorithms, and a passive ranging methodology tailored to the needs of helicopter flight are discussed. Preliminary results indicate that it is possible to obtain adequate range estimates except at regions close to the FOE. Closer to the FOE, the error in range increases since the magnitude of the disparity gets smaller, resulting in a low SNR.

  6. Quantitative depth profiling in glow discharge spectroscopies - A new deconvolution technique to separate effects of an uneven erosion crater shape.

    PubMed

    Prässler, F; Hoffmann, V; Schumann, J; Wetzig, K

    1996-07-01

    An algorithm is presented as a concept for the quantification in direct current and radiofrequency glow discharge (GD) modes for GD optical emission spectroscopy. The algorithm is divided into excitation and sputtering part and thus it is possible to distinguish between the different excitation processes and to consider equivalent sputtering crater formations in both modes. Intensity-time profiles are affected corresponding to the method by several effects. One important effect is that sputtering occurs at a single time in different depths because of curved crater bottoms, this is usually called crater effect. The main purpose is to introduce an iterative deconvolution technique which for the quantification numerically takes into account the curved sputtering crater bottom. Input data for the deconvolution technique are the calibrated mass-time profile, the partial densities of the sample constituents and the measured final shape of the sputtering crater. Using a relatively simple model for ion sputtering the deconvolution technique improves iteratively the calculated layer structure by means of information on crater formation. The mathematical handling is illustrated for the quantification of a depth profile of a multilayer sample of ten 100 nm layers. The resulting concentration-depth profile reflects excellently the real elemental distribution of the multilayer system.

  7. DHARMA - Discriminant hyperplane abstracting residuals minimization algorithm for separating clusters with fuzzy boundaries. [data points pattern recognition technique

    NASA Technical Reports Server (NTRS)

    Dasarathy, B. V.

    1976-01-01

    Learning of discriminant hyperplanes in imperfectly supervised or unsupervised training sample sets with unreliably labeled samples along the fuzzy joint boundaries between sample clusters is discussed, with the discriminant hyperplane designed to be a least-squares fit to the unreliably labeled data points. (Samples along the fuzzy boundary jump back and forth from one cluster to the other in recursive cluster stabilization and are considered unreliably labeled.) Minimization of the distances of these unreliably labeled samples from the hyperplanes does not sacrifice the ability to discriminate between classes represented by reliably labeled subsets of samples. An equivalent unconstrained linear inequality problem is formulated and algorithms for its solution are indicated. Landsat earth sensing data were used in confirming the validity and computational feasibility of the approach, which should be useful in deriving discriminant hyperplanes separating clusters with fuzzy boundaries, given supervised training sample sets with unreliably labeled boundary samples.

  8. Acoustic Biometric System Based on Preprocessing Techniques and Linear Support Vector Machines

    PubMed Central

    del Val, Lara; Izquierdo-Fuente, Alberto; Villacorta, Juan J.; Raboso, Mariano

    2015-01-01

    Drawing on the results of an acoustic biometric system based on a MSE classifier, a new biometric system has been implemented. This new system preprocesses acoustic images, extracts several parameters and finally classifies them, based on Support Vector Machine (SVM). The preprocessing techniques used are spatial filtering, segmentation—based on a Gaussian Mixture Model (GMM) to separate the person from the background, masking—to reduce the dimensions of images—and binarization—to reduce the size of each image. An analysis of classification error and a study of the sensitivity of the error versus the computational burden of each implemented algorithm are presented. This allows the selection of the most relevant algorithms, according to the benefits required by the system. A significant improvement of the biometric system has been achieved by reducing the classification error, the computational burden and the storage requirements. PMID:26091392

  9. Acoustic Biometric System Based on Preprocessing Techniques and Linear Support Vector Machines.

    PubMed

    del Val, Lara; Izquierdo-Fuente, Alberto; Villacorta, Juan J; Raboso, Mariano

    2015-06-17

    Drawing on the results of an acoustic biometric system based on a MSE classifier, a new biometric system has been implemented. This new system preprocesses acoustic images, extracts several parameters and finally classifies them, based on Support Vector Machine (SVM). The preprocessing techniques used are spatial filtering, segmentation-based on a Gaussian Mixture Model (GMM) to separate the person from the background, masking-to reduce the dimensions of images-and binarization-to reduce the size of each image. An analysis of classification error and a study of the sensitivity of the error versus the computational burden of each implemented algorithm are presented. This allows the selection of the most relevant algorithms, according to the benefits required by the system. A significant improvement of the biometric system has been achieved by reducing the classification error, the computational burden and the storage requirements.

  10. Guide to CO{sub 2} separations in imidazolium-based room-temperature ionic liquids

    SciTech Connect

    Bara, J.E.; Carlisle, T.K.; Gabriel, C.J.; Camper, D.; Finotello, A.; Gin, D.L.; Noble, R.D.

    2009-03-18

    Room-temperature ionic liquids (RTILs) are nonvolatile, tunable solvents. The solubilities of gases, particularly CO{sub 2}, N{sub 2}, and CH{sub 4}, have been studied in a number of RTILs. Process temperature and the chemical structures of the cation and anion have significant impacts on gas solubility and gas pair selectivity. Models based on regular solution theory and group contributions are useful to predict and explain CO{sub 2} solubility and selectivity in imidazolium-based RTILs. In addition to their role as a physical solvent, RTILs might also be used in supported ionic liquid membranes (SILMs) as a highly permeable and selective transport medium. Performance data for SILMs indicates that they exhibit large permeabilities as well as CO{sub 2}/N{sub 2} selectivities that outperform many polymer membranes. Furthermore, the greatest potential of RTILs for CO{sub 2} separations might lie in their ability to chemically capture CO{sub 2} when used in combination with amines. Amines can be tethered to the cation or the anion, or dissolved in RTILs, providing a wide range of chemical solvents for CO{sub 2} capture. However, despite all of their promising features, RTILs do have drawbacks to use in CO{sub 2} separations, which have been overlooked as appropriate comparisons of RTILs to common organic solvents and polymers have not been reported. A thorough summary of the capabilities-and limitations-of imidazolium-based RTILs in CO{sub 2}-based separations with respect to a variety of materials is thus provided.

  11. Sliding-triboelectric nanogenerators based on in-plane charge-separation mechanism.

    PubMed

    Wang, Sihong; Lin, Long; Xie, Yannan; Jing, Qingshen; Niu, Simiao; Wang, Zhong Lin

    2013-05-08

    Aiming at harvesting ambient mechanical energy for self-powered systems, triboelectric nanogenerators (TENGs) have been recently developed as a highly efficient, cost-effective and robust approach to generate electricity from mechanical movements and vibrations on the basis of the coupling between triboelectrification and electrostatic induction. However, all of the previously demonstrated TENGs are based on vertical separation of triboelectric-charged planes, which requires sophisticated device structures to ensure enough resilience for the charge separation, otherwise there is no output current. In this paper, we demonstrated a newly designed TENG based on an in-plane charge separation process using the relative sliding between two contacting surfaces. Using Polyamide 6,6 (Nylon) and polytetrafluoroethylene (PTFE) films with surface etched nanowires, the two polymers at the opposite ends of the triboelectric series, the newly invented TENG produces an open-circuit voltage up to ~1300 V and a short-circuit current density of 4.1 mA/m(2) with a peak power density of 5.3 W/m(2), which can be used as a direct power source for instantaneously driving hundreds of serially connected light-emitting diodes (LEDs). The working principle and the relationships between electrical outputs and the sliding motion are fully elaborated and systematically studied, providing a new mode of TENGs with diverse applications. Compared to the existing vertical-touching based TENGs, this planar-sliding TENG has a high efficiency, easy fabrication, and suitability for many types of mechanical triggering. Furthermore, with the relationship between the electrical output and the sliding motion being calibrated, the sliding-based TENG could potentially be used as a self-powered displacement/speed/acceleration sensor.

  12. An open trial of Acceptance-based Separated Family Treatment (ASFT) for adolescents with anorexia nervosa.

    PubMed

    Timko, C Alix; Zucker, Nancy L; Herbert, James D; Rodriguez, Daniel; Merwin, Rhonda M

    2015-06-01

    Family based-treatments have the most empirical support in the treatment of adolescent anorexia nervosa; yet, a significant percentage of adolescents and their families do not respond to manualized family based treatment (FBT). The aim of this open trial was to conduct a preliminary evaluation of an innovative family-based approach to the treatment of anorexia: Acceptance-based Separated Family Treatment (ASFT). Treatment was grounded in Acceptance and Commitment Therapy (ACT), delivered in a separated format, and included an ACT-informed skills program. Adolescents (ages 12-18) with anorexia or sub-threshold anorexia and their families received 20 treatment sessions over 24 weeks. Outcome indices included eating disorder symptomatology reported by the parent and adolescent, percentage of expected body weight achieved, and changes in psychological acceptance/avoidance. Half of the adolescents (48.0%) met criteria for full remission at the end of treatment, 29.8% met criteria for partial remission, and 21.3% did not improve. Overall, adolescents had a significant reduction in eating disorder symptoms and reached expected body weight. Treatment resulted in changes in psychological acceptance in the expected direction for both parents and adolescents. This open trial provides preliminary evidence for the feasibility, acceptability, and efficacy of ASFT for adolescents with anorexia. Directions for future research are discussed.

  13. Antimisting kerosene: Base fuel effects, blending and quality control techniques

    NASA Technical Reports Server (NTRS)

    Yavrouian, A. H.; Ernest, J.; Sarohia, V.

    1984-01-01

    The problems associated with blending of the AMK additive with Jet A, and the base fuel effects on AMK properties are addressed. The results from the evaluation of some of the quality control techniques for AMK are presented. The principal conclusions of this investigation are: significant compositional differences for base fuel (Jet A) within the ASTM specification DI655; higher aromatic content of the base fuel was found to be beneficial for the polymer dissolution at ambient (20 C) temperature; using static mixer technology, the antimisting additive (FM-9) is in-line blended with Jet A, producing AMK which has adequate fire-protection properties 15 to 20 minutes after blending; degradability of freshly blended and equilibrated AMK indicated that maximum degradability is reached after adequate fire protection is obtained; the results of AMK degradability as measured by filter ratio, confirmed previous RAE data that power requirements to decade freshly blended AMK are significantly higher than equilibrated AMK; blending of the additive by using FM-9 concentrate in Jet A produces equilibrated AMK almost instantly; nephelometry offers a simple continuous monitoring capability and is used as a real time quality control device for AMK; and trajectory (jet thurst) and pressure drop tests are useful laboratory techniques for evaluating AMK quality.

  14. Color demosaicking using deinterlacing and median-based filtering techniques

    NASA Astrophysics Data System (ADS)

    Huang, Wen-Tsung; Chen, Wen-Jan; Tai, Shen-Chuan

    2010-10-01

    Color demosaicking is critical to the image quality of single-sensor-based imaging devices. Caused by the sampling pattern of color filter array (CFA), the demosaicked images typically suffer from visual color artifacts in regions of high frequency and sharp edge structures, degrading the quality of camera output. We present a new high-quality demosaicking algorithm by taking advantage of deinterlacing and median-based filtering techniques. We treat the sampled green data of Bayer CFA as a form of diagonal interlaced green planes and make use of some key concepts about spatial deinterlacing to help the edge estimation in terms of both various directions and accuracy. In addition, a specific edge feature, sharp line edge of width 1 pixel, can also be handed well by the proposed method. The median-based filtering techniques are developed for suppressing most visual demosaicking artifacts, such as zipper effect, false color artifact, and interpolation artifact. Experimental results show that our algorithm is effective in suppressing visual artifacts, preserving the edges of image with sharpness and satisfying visual inspection, while keeping computational efficiency.

  15. Severe Hemolysis in a Patient With Erythrocytosis During Coupled Plasma Filtration Adsorption Therapy Was Prevented by Changing From Membrane-Based Technique to a Centrifuge-Based One.

    PubMed

    Fan, Rong; Wu, Buyun; Kong, Ling; Gong, Dehua

    2016-01-01

    Coupled plasma filtration adsorption (CPFA) usually adopts membrane to separate plasma from blood. Here, we reported a case with erythrocytosis experienced severe hemolysis and membrane rupture during CPFA, which was avoided by changing from membrane-based technique to a centrifuge-based one. A 66-year-old man was to receive CPFA for severe hyperbilirubinemia (total bilirubin 922 μmol/L, direct bilirubin 638 μmol/L) caused by obstruction of biliary tract. He had erythrocytosis (hemoglobin 230 g/L, hematocrit 0.634) for years because of untreated tetralogy of Fallot. Severe hemolysis and membrane rupture occurred immediately after blood entering into the plasma separator even at a low flow rate (50 mL/min) and persisted after changing a new separator. Finally, centrifugal plasma separation technique was used for CPFA in this patient, and no hemolysis occurred. After 3 sessions of CPFA, total bilirubin level decreased to 199 μmol/L with an average decline by 35% per session. Thereafter, the patient received endoscopic biliary stent implantation, and total bilirubin level returned to nearly normal. Therefore, centrifugal-based plasma separation can also be used in CPFA and may be superior to a membrane-based one in patients with hyperviscosity.

  16. Ceramic separators based on Li+-conducting inorganic electrolyte for high-performance lithium-ion batteries with enhanced safety

    NASA Astrophysics Data System (ADS)

    Jung, Yun-Chae; Kim, Seul-Ki; Kim, Moon-Sung; Lee, Jeong-Hye; Han, Man-Seok; Kim, Duck-Hyun; Shin, Woo-Cheol; Ue, Makoto; Kim, Dong-Won

    2015-10-01

    Flexible ceramic separators based on Li+-conducting lithium lanthanum zirconium oxide are prepared as thin films and directly applied onto negative electrode to produce a separator-electrode assembly with good interfacial adhesion and low interfacial resistances. The ceramic separators show an excellent thermal stability and high ionic conductivity as compared to conventional polypropylene separator. The lithium-ion batteries assembled with graphite negative electrode, Li+-conducting ceramic separator and LiCoO2 positive electrode exhibit good cycling performance in terms of discharge capacity, capacity retention and rate capability. It is also demonstrated that the use of a ceramic separator can greatly improve safety over cells employing a polypropylene separator, which is highly desirable for lithium-ion batteries with enhanced safety.

  17. Gearbox diagnostics using wavelet-based windowing technique

    NASA Astrophysics Data System (ADS)

    Omar, F. K.; Gaouda, A. M.

    2009-08-01

    In extracting gear box acoustic signals embedded in excessive noise, the need for an online and automated tool becomes a crucial necessity. One of the recent approaches that have gained some acceptance within the research arena is the Wavelet multi-resolution analysis (WMRA). However selecting an accurate mother wavelet, defining dynamic threshold values and identifying the resolution levels to be considered in gearboxes fault detection and diagnosis are still challenging tasks. This paper proposes a novel wavelet-based technique for detecting, locating and estimating the severity of defects in gear tooth fracture. The proposed technique enhances the WMRA by decomposing the noisy data into different resolution levels while data sliding it into Kaiser's window. Only the maximum expansion coefficients at each resolution level are used in de-noising, detecting and measuring the severity of the defects. A small set of coefficients is used in the monitoring process without assigning threshold values or performing signal reconstruction. The proposed monitoring technique has been applied to a laboratory data corrupted with high noise level.

  18. Radiation-Based Medical Imaging Techniques: An Overview

    NASA Astrophysics Data System (ADS)

    Prior, John O.; Lecoq, Paul

    This chapter will present an overview of two radiation-based medical imaging techniques using radiopharmaceuticals used in nuclear medicine/molecular imaging, namely, single-photon emission computed tomography (SPECT) and positron emission tomography (PET). The relative merits in terms of radiation sensitivity and image resolution of SPECT and PET will be compared to the main conventional radiologic modalities that are computed tomography (CT) and magnetic resonance (MR) imaging. Differences in terms of temporal resolution will also be outlined, as well as the other similarities and dissimilarities of these two techniques, including their latest and upcoming multimodality combination. The main clinical applications are briefly described and examples of specific SPECT and PET radiopharmaceuticals are listed. SPECT and PET imaging will be then further detailed in the two subsequent chapters describing in greater depth the basics and future trends of each technique (see Chaps. 37, "SPECT Imaging: Basics and New Trends" 10.1007/978-3-642-13271-1_37 and 38, "PET Imaging: Basics and New Trends" 10.1007/978-3-642-13271-1_38.

  19. Separation of sperm and epithelial cells based on the hydrodynamic effect for forensic analysis

    PubMed Central

    Liu, Weiran; Chen, Weixing; Liu, Ran; Ou, Yuan; Liu, Haoran; Xie, Lan; Lu, Ying; Li, Caixia; Li, Bin; Cheng, Jing

    2015-01-01

    In sexual assault cases, forensic samples are a mixture of sperm from the perpetrator and epithelial cells from the victim. To obtain an independent short tandem repeat (STR) profile of the perpetrator, sperm cells must be separated from the mixture of cells. However, the current method used in crime laboratories, namely, differential extraction, is a time-consuming and labor-intensive process. To achieve a rapid and automated sample pretreatment process, we fabricated a microdevice for hydrodynamic and size-based separation of sperm and epithelial cells. When cells in suspension were introduced into the device's microfluidic channels, they were forced to flow along different streamlines and into different outlets due to their different diameters. With the proposed microdevice, sperm can be separated within a short period of time (0.5 h for a 50-μl mock sample). The STR profiles of the products in the sperm outlet reservoir demonstrated that a highly purified male DNA fraction could be obtained (94.0% male fraction). This microdevice is of low-cost and can be easily integrated with other subsequent analysis units, providing great potential in the process of analyzing sexual assault evidence as well as in other areas requiring cell sorting. PMID:26392829

  20. Automated integer programming based separation of arteries and veins from thoracic CT images.

    PubMed

    Payer, Christian; Pienn, Michael; Bálint, Zoltán; Shekhovtsov, Alexander; Talakic, Emina; Nagy, Eszter; Olschewski, Andrea; Olschewski, Horst; Urschler, Martin

    2016-12-01

    Automated computer-aided analysis of lung vessels has shown to yield promising results for non-invasive diagnosis of lung diseases. To detect vascular changes which affect pulmonary arteries and veins differently, both compartments need to be identified. We present a novel, fully automatic method that separates arteries and veins in thoracic computed tomography images, by combining local as well as global properties of pulmonary vessels. We split the problem into two parts: the extraction of multiple distinct vessel subtrees, and their subsequent labeling into arteries and veins. Subtree extraction is performed with an integer program (IP), based on local vessel geometry. As naively solving this IP is time-consuming, we show how to drastically reduce computational effort by reformulating it as a Markov Random Field. Afterwards, each subtree is labeled as either arterial or venous by a second IP, using two anatomical properties of pulmonary vessels: the uniform distribution of arteries and veins, and the parallel configuration and close proximity of arteries and bronchi. We evaluate algorithm performance by comparing the results with 25 voxel-based manual reference segmentations. On this dataset, we show good performance of the subtree extraction, consisting of very few non-vascular structures (median value: 0.9%) and merged subtrees (median value: 0.6%). The resulting separation of arteries and veins achieves a median voxel-based overlap of 96.3% with the manual reference segmentations, outperforming a state-of-the-art interactive method. In conclusion, our novel approach provides an opportunity to become an integral part of computer aided pulmonary diagnosis, where artery/vein separation is important.

  1. A rapid technique for lymphocyte preparation prior to two-color immunofluorescence analysis of lymphocyte subsets using flow cytometry. Comparison with density gradient separation.

    PubMed

    Mansour, I; Bourin, P; Rouger, P; Doinel, C

    1990-02-20

    A technique is described for lymphocyte preparation which permits analyses by two-color immunofluorescence and flow cytometry. It consists, briefly, of the lysis of red blood cells and washing of white blood cells prior to labeling. We tested this technique with a large panel of monoclonal antibodies in mono- and dual immunofluorescence. By comparing these results to those obtained after density gradient separation, we found the following statistically significant differences: the count of the phenotype B1+ was higher after whole blood lysis preparation than after density gradient separation; whereas, the corresponding counts of OKT4+ and Leu-4-Leu-7+ phenotypes were lower. No difference was detected with OKT8+, Leu-4+, OKT8+Leu-4+, OKT8+Leu-4-, OKT8-Leu-4+, OKT8+Leu-7+, Leu-4+Leu-7+, Leu-4-Leu-11c+, OKT8+Leu-11c+ and OKT8+Leu-15+ phenotypes. We have studied the reproducibility of both methods and the correlation between them. The disparity of the lymphocyte subset count between these two methods, though statistically significant, was relatively weak and seems to be due to the density gradient separation. Since the preparation of lymphocytes using the density gradient method is time consuming, we propose whole blood lysis as an alternative lymphocyte separation method when assessing immune status in human disease by flow cytometry. It offers the following advantages: (i) it does not require additional steps, (ii) it permits two-color immunofluorescence through the labeling of white blood cells after washing, (iii) it is reliable, (iv) it is reproducible, and (v) it is helpful in studies of lymphopenia since it offers the possibility of lymphocyte enrichment.

  2. Selection and Separation of Viable Cells Based on a Cell-Lethal Assay

    PubMed Central

    Xu, Wei; Herman, Annadele; Phillips, Colleen; Pai, Jeng-Hao; Sims, Christopher E.; Allbritton, Nancy L.

    2010-01-01

    A method to select and separate viable cells based on the results of a cell-lethal assay was developed. Cells were plated on an array of culture sites with each site composed of closely spaced, releasable micropallets. Clonal colonies spanning multiple micropallets on individual culture sites were established within 72 h of plating. Adjacent sites were widely spaced with 100% of the colonies remaining sequestered on a single culture site during expansion. A laser-based method mechanically released a micropallet underlying a colony to segment the colony into two genetically identical colonies. One portion of the segmented colony was collected with 90% efficiency while viability of both fractions was 100%. The segmented colonies released from the array were fixed and subjected to immunofluorescence staining of intracellular phospho-ERK kinase to identify colonies that were highly resistant or sensitive to phorbol ester-induced activation of ERK. These resistant and sensitive cells were then matched to the corresponding viable colonies on the array. Sensitive and resistant colonies on the array were released and cultured. When these cultured cells were reanalyzed for phorbol ester-induced ERK activity, the cells retained the sensitive or resistant phenotype of the originally screened subcolony. Thus cells were separated and collected based using the result of a cell-lethal assay as selection criteria. These microarrays enabling clonal colony segmentation permitted sampling and manipulation of the colonies at very early times and at small cell numbers to reduce reagent, time and manpower requirements. PMID:21142138

  3. A computational approach to predicting ligand selectivity for the size-based separation of trivalent lanthanides

    SciTech Connect

    Ivanov, Alexander S.; Bryantsev, Vyacheslav S.

    2016-06-20

    An accurate description of solvation effects for trivalent lanthanide ions is a main stumbling block to the qualitative prediction of selectivity trends along the lanthanide series. In this work, we propose a simple model to describe the differential effect of solvation in the competitive binding of a ligand by lanthanide ions by including weakly co-ordinated counterions in the complexes of more than a +1 charge. The success of the approach to quantitatively reproduce selectivities obtained from aqueous phase complexation studies demonstrates its potential for the design and screening of new ligands for efficient size-based separation.

  4. Temperature effect on thin lipid film elasticity and phase separation: insights from Langmuir monolayer and fluorescence microscopy techniques

    NASA Astrophysics Data System (ADS)

    Khattari, Z.; Maghrabi, M.; Al-Abdullah, T.

    2015-07-01

    Langmuir monolayer pressure isotherms and compressibility modulus measurements of phospholipid mixtures in several Langmuir monolayer systems at the air/water interface were investigated in this study. The ultimate aim was to carry out a comparison of the elasticity modulus for monolayers with different mixtures of l,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), l,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and chicken egg yolk sphingomyelin (eSM), in the presence/absence of cholesterol (Chol). In particular, we were able to propose that the leading force beyond the phase separation into liquid expanded (LE-) and liquid condensed (LC-) phases emerges from the increasing barrier to incorporate DOPC molecules into a highly ordered LC-phase. In addition, our findings suggest that DOPC lipid molecules have a priority to incorporate in a disordered LE-phase, while DPPC and eSM prefer the ordered one. Also, Chol seems to split almost equally into both phases, indicating that Chol has no priority for either phase and there are no particular interactions between Chol and saturated lipid molecules.

  5. Rapid detection of Escherichia coli and enterococci in recreational water using an immunomagnetic separation/adenosine triphosphate technique

    USGS Publications Warehouse

    Bushon, R.N.; Brady, A.M.; Likirdopulos, C.A.; Cireddu, J.V.

    2009-01-01

    Aims: The aim of this study was to examine a rapid method for detecting Escherichia coli and enterococci in recreational water. Methods and Results: Water samples were assayed for E. coli and enterococci by traditional and immunomagnetic separation/adenosine triphosphate (IMS/ATP) methods. Three sample treatments were evaluated for the IMS/ATP method: double filtration, single filtration, and direct analysis. Pearson's correlation analysis showed strong, significant, linear relations between IMS/ATP and traditional methods for all sample treatments; strongest linear correlations were with the direct analysis (r = 0.62 and 0.77 for E. coli and enterococci, respectively). Additionally, simple linear regression was used to estimate bacteria concentrations as a function of IMS/ATP results. The correct classification of water-quality criteria was 67% for E. coli and 80% for enterococci. Conclusions: The IMS/ATP method is a viable alternative to traditional methods for faecal-indicator bacteria. Significance and Impact of the Study: The IMS/ATP method addresses critical public health needs for the rapid detection of faecal-indicator contamination and has potential for satisfying US legislative mandates requiring methods to detect bathing water contamination in 2 h or less. Moreover, IMS/ATP equipment is considerably less costly and more portable than that for molecular methods, making the method suitable for field applications. ?? 2009 The Authors.

  6. Thiophene-based monolayer OFETs prepared by Langmuir techniques

    NASA Astrophysics Data System (ADS)

    Agina, Elena V.; Sizov, Alexey S.; Anisimov, Daniil S.; Trul, Askold A.; Borshchev, Oleg V.; Paraschuk, Dmitry Y.; Shcherbina, Maxim A.; Chvalun, Sergey N.; Ponomarenko, Sergey A.

    2015-08-01

    A novel fast, easily processible and highly reproducible approach to thiophene-based monolayer OFETs fabrication by Langmuir-Blodgett or Langmuir-Schaefer techniques was developed and successfully applied. It is based on selfassembly of organosilicon derivatives of oligothiophenes or benzothienobenzothiophene on the water-air interface. Influence of the conjugation length and the anchor group chemistry of the self-assembling molecules on the monolayer structure and electric performance of monolayer OFETs was systematically investigated. The efficient monolayer OFETs with the charge carrier mobilities up to 0.01 cm2/Vs and on/off ratio up to 106 were fabricated, and their functionality in integrated circuits under normal air conditions was demonstrated.

  7. Evolutionary Based Techniques for Fault Tolerant Field Programmable Gate Arrays

    NASA Technical Reports Server (NTRS)

    Larchev, Gregory V.; Lohn, Jason D.

    2006-01-01

    The use of SRAM-based Field Programmable Gate Arrays (FPGAs) is becoming more and more prevalent in space applications. Commercial-grade FPGAs are potentially susceptible to permanently debilitating Single-Event Latchups (SELs). Repair methods based on Evolutionary Algorithms may be applied to FPGA circuits to enable successful fault recovery. This paper presents the experimental results of applying such methods to repair four commonly used circuits (quadrature decoder, 3-by-3-bit multiplier, 3-by-3-bit adder, 440-7 decoder) into which a number of simulated faults have been introduced. The results suggest that evolutionary repair techniques can improve the process of fault recovery when used instead of or as a supplement to Triple Modular Redundancy (TMR), which is currently the predominant method for mitigating FPGA faults.

  8. Risk-based maintenance--techniques and applications.

    PubMed

    Arunraj, N S; Maiti, J

    2007-04-11

    Plant and equipment, however well designed, will not remain safe or reliable if it is not maintained. The general objective of the maintenance process is to make use of the knowledge of failures and accidents to achieve the possible safety with the lowest possible cost. The concept of risk-based maintenance was developed to inspect the high-risk components usually with greater frequency and thoroughness and to maintain in a greater manner, to achieve tolerable risk criteria. Risk-based maintenance methodology provides a tool for maintenance planning and decision making to reduce the probability of failure of equipment and the consequences of failure. In this paper, the risk analysis and risk-based maintenance methodologies were identified and classified into suitable classes. The factors affecting the quality of risk analysis were identified and analyzed. The applications, input data and output data were studied to understand their functioning and efficiency. The review showed that there is no unique way to perform risk analysis and risk-based maintenance. The use of suitable techniques and methodologies, careful investigation during the risk analysis phase, and its detailed and structured results are necessary to make proper risk-based maintenance decisions.

  9. Modern Micro and Nanoparticle-Based Imaging Techniques

    PubMed Central

    Ryvolova, Marketa; Chomoucka, Jana; Drbohlavova, Jana; Kopel, Pavel; Babula, Petr; Hynek, David; Adam, Vojtech; Eckschlager, Tomas; Hubalek, Jaromir; Stiborova, Marie; Kaiser, Jozef; Kizek, Rene

    2012-01-01

    The requirements for early diagnostics as well as effective treatment of insidious diseases such as cancer constantly increase the pressure on development of efficient and reliable methods for targeted drug/gene delivery as well as imaging of the treatment success/failure. One of the most recent approaches covering both the drug delivery as well as the imaging aspects is benefitting from the unique properties of nanomaterials. Therefore a new field called nanomedicine is attracting continuously growing attention. Nanoparticles, including fluorescent semiconductor nanocrystals (quantum dots) and magnetic nanoparticles, have proven their excellent properties for in vivo imaging techniques in a number of modalities such as magnetic resonance and fluorescence imaging, respectively. In this article, we review the main properties and applications of nanoparticles in various in vitro imaging techniques, including microscopy and/or laser breakdown spectroscopy and in vivo methods such as magnetic resonance imaging and/or fluorescence-based imaging. Moreover the advantages of the drug delivery performed by nanocarriers such as iron oxides, gold, biodegradable polymers, dendrimers, lipid based carriers such as liposomes or micelles are also highlighted. PMID:23202187

  10. A polarization-based Thomson scattering technique for burning plasmas

    NASA Astrophysics Data System (ADS)

    Parke, E.; Mirnov, V. V.; Den Hartog, D. J.

    2014-02-01

    The traditional Thomson scattering diagnostic is based on measurement of the wavelength spectrum of scattered light, where electron temperature measurements are inferred from thermal broadening of the spectrum. At sufficiently high temperatures, especially those predicted for ITER and other burning plasmas, relativistic effects cause a change in the degree of polarization (P) of the scattered light; for fully polarized incident laser light, the scattered light becomes partially polarized. The resulting reduction of polarization is temperature dependent and has been proposed by other authors as a potential alternative to the traditional spectral decomposition technique. Following the previously developed Stokes vector approach, we analytically calculate the degree of polarization for incoherent Thomson scattering. For the first time, we obtain exact results valid for the full range of incident laser polarization states, scattering angles, and electron temperatures. While previous work focused only on linear polarization, we show that circularly polarized incident light optimizes the degree of depolarization for a wide range of temperatures relevant to burning plasmas. We discuss the feasibility of a polarization based Thomson scattering diagnostic for ITER-like plasmas with both linearly and circularly polarized light and compare to the traditional technique.

  11. Membrane gas separation. January 1970-September 1989 (Citations from the NTIS data base). Report for January 1970-September 1989

    SciTech Connect

    Not Available

    1989-09-01

    This bibliography contains citations concerning the research and development of gas separation and purification utilizing plastic and metal membranes. Among the topics included are isotope separation, osmotic techniques, reverse osmosis, and preparation of membranes for specific separation processes. The permeability of polymer membranes is discussed in terms of physical properties as well as molecular structure. The selectivity of polymeric films for a variety of gases is also included. (This updated bibliography contains 100 citations, 18 of which are new entries to the previous edition.)

  12. Membrane gas separation. January 1970-September 1988 (Citations from the NTIS data base). Report for January 1970-September 1988

    SciTech Connect

    Not Available

    1988-09-01

    This bibliography contains citations concerning the research and development of gas separation and purification utilizing plastic and metal membranes. Among the topics included are isotope separation, osmotic techniques, reverse osmosis, and preparation of membranes for specific separation processes. The permeability of polymer membranes is discussed in terms of physical properties as well as molecular structure. The selectivity of polymeric films for a variety of gases is also included. (This updated bibliography contains 150 citations, 27 of which are new entries to the previous edition.)

  13. Hydrodynamic and direct-current insulator-based dielectrophoresis (H-DC-iDEP) microfluidic blood plasma separation.

    PubMed

    Mohammadi, Mahdi; Madadi, Hojjat; Casals-Terré, Jasmina; Sellarès, Jordi

    2015-06-01

    Evaluation and diagnosis of blood alterations is a common request for clinical laboratories, requiring a complex technological approach and dedication of health resources. In this paper, we present a microfluidic device that owing to a novel combination of hydrodynamic and dielectrophoretic techniques can separate plasma from fresh blood in a microfluidic channel and for the first time allows optical real-time monitoring of the components of plasma without pre- or post-processing. The microchannel is based on a set of dead-end branches at each side and is initially filled using capillary forces with a 2-μL droplet of fresh blood. During this process, stagnation zones are generated at the dead-end branches and some red blood cells (RBCs) are trapped there. An electric field is then applied and dielectrophoretic trapping of RBCs is used to prevent more RBCs entering into the channel, which works like a sieve. Besides, an electroosmotic flow is generated to sweep the rest of the RBCs from the central part of the channel. Consequently, an RBC-free zone of plasma is formed in the middle of the channel, allowing real-time monitoring of the platelet behavior. To study the generation of stagnation zones and to ensure RBC trapping in the initial constrictions, two numerical models were solved. The proposed experimental design separates up to 0.1 μL blood plasma from a 2-μL fresh human blood droplet. In this study, a plasma purity of 99 % was achieved after 7 min, according to the measurements taken by image analysis. Graphical Abstract Schematics of a real-time plasma monitoring system based on a Hydrodynamic and direct-current insulator-based dielectrophoresis microfluidic channel.

  14. Separate collection of household food waste for anaerobic degradation - Comparison of different techniques from a systems perspective.

    PubMed

    Bernstad, A; la Cour Jansen, J

    2012-05-01

    Four systems for household food waste collection are compared in relation the environmental impact categories eutrophication potential, acidification potential, global warming potential as well as energy use. Also, a hotspot analysis is performed in order to suggest improvements in each of the compared collection systems. Separate collection of household food waste in paper bags (with and without drying prior to collection) with use of kitchen grinders and with use of vacuum system in kitchen sinks were compared. In all cases, food waste was used for anaerobic digestion with energy and nutrient recovery in all cases. Compared systems all resulted in net avoidance of assessed environmental impact categories; eutrophication potential (-0.1 to -2.4kg NO(3)(-)eq/ton food waste), acidification potential (-0.4 to -1.0kg SO(2)(-)eq/ton food waste), global warming potential (-790 to -960kg CO(2)(-)eq/ton food waste) and primary energy use (-1.7 to -3.6GJ/ton food waste). Collection with vacuum system results in the largest net avoidence of primary energy use, while disposal of food waste in paper bags for decentralized drying before collection result in a larger net avoidence of global warming, eutrophication and acidification. However, both these systems not have been taken into use in large scale systems yet and further investigations are needed in order to confirm the outcomes from the comparison. Ranking of scenarios differ largely if considering only emissions in the foreground system, indicating the importance of taking also downstream emissions into consideration when comparing different collection systems. The hot spot identification shows that losses of organic matter in mechanical pretreatment as well as tank connected food waste disposal systems and energy in drying and vacuum systems reply to the largest impact on the results in each system respectively.

  15. Early stage phase separation in pharmaceutical solid dispersion thin films under high humidity: improved spatial understanding using probe-based thermal and spectroscopic nanocharacterization methods.

    PubMed

    Qi, Sheng; Moffat, Jonathan G; Yang, Ziyi

    2013-03-04

    Phase separation in pharmaceutical solid dispersion thin films under high humidity is still poorly understood on the submicrometer scale. This study investigated the phase separation of a model solid dispersion thin film, felodipine-PVP K29/32, prepared by spin-coating and analyzed using probe-based methods including atomic force microscopy, nanothermal analysis, and photothermal infrared microspectroscopy. The combined use of these techniques revealed that the phase separation process occurring in the thin films under high humidity is different from that in dry conditions reported previously. The initial stage of phase separation is primarily initiated in the bulk of the films as amorphous drug domains. Drug migration toward the surface of the solid dispersion film was then observed to occur under exposure to increased humidity. PVP cannot prevent phase separation of felodipine under high humidity but can minimize the crystallization of amorphous felodipine domains in the solid dispersion thin films. This study demonstrates the unique abilities of these nanocharacterization methods for studying, in three dimensions, the phase separation of thin films for pharmaceutical applications.

  16. All-optical packet header and payload separation based on two TOADs for optical packet switched networks

    NASA Astrophysics Data System (ADS)

    Ji, Wei; Zhang, Min; Ye, Peida

    2006-09-01

    We present a novel all-optical header and payload separation technique that can be utilized in Un-Slotted optical packet switched networks. The technique uses two modified TOADs, one is for packet header extraction with differential modulation scheme and the other performs a simple XOR operation between the packet and its self-derived header to get the separated payload. The main virtue of this system is simple structure and low power consumption. Through numerical simulations, the operating characteristics of the scheme are illustrated. In addition, the system parameters are discussed and designed to optimize the performance of the proposed scheme.

  17. Separation & Fixation of Toxic Components in Salt Brines Using a Water-Based Process

    SciTech Connect

    Franks, Carrie J.; Quach, Anh P.; Birnie, Dunbar P.; Ela, Wendell P.; Saez, Avelino E.; Zelinski, Brian J.; Smith, Harry D.; Smith, Gary Lynn L.

    2004-12-01

    Efforts to implement new water quality standards, increase water reuse and reclamation, and minimize the cost of waste storage motivate the development of new processes for stabilizing waste water residuals that minimize waste volume, water content and the long-term environmental risk from related by products. This work explores the use of an aqueous-based emulsion process to create an epoxy/rubber matrix for separating and encapsulating waste components from salt laden, arsenic contaminated, amorphous iron hydrate sludges. Such sludges are generated from conventional water purification precipitation/adsorption processes, used to convert aqueous brine streams to semi-solid waste streams, such as ion exchange/membrane separation, and from other precipitative heavy metal removal operations. In this study, epoxy and polystyrene butadiene (PSB) rubber emulsions are mixed together and then combined with a surrogate sludge. The surrogate sludge consists of amorphous iron hydrate with 1 part arsenic fixed to the surface of the hydrate per 10 parts iron mixed with sodium nitrate and chloride salts and water. The resulting emulsion is cured and dried at 80 C to remove water. Microstructure characterization by electron microscopy confirms that the epoxy/PSB matrix surrounds and encapsulates the arsenic laden amorphous iron hydrate phase while allowing the salt to migrate to internal and external surfaces of the sample. Salt extraction studies indicate that the porous nature of the resulting matrix promotes the separation and removal of as much as 90% of the original salt content in only one hours time. Long term leaching studies based on the use of the infinite slab diffusion model reveal no evidence of iron migration or, by inference, arsenic migration, and demonstrate that the diffusion coefficients of the unextracted salt yield leachability indices within regulations for non-hazardous landfill disposal. Because salt is the most mobile species, it is inferred that arsenic

  18. Separation and Fixation of Toxic Components in Salt Brines Using a Water-Based Process

    SciTech Connect

    Franks, C.; Quach, A.; Birnie III, D.; Ela, W.; Saez, A.E.; Zelinski, B.; Smith, H.; Smith, G.

    2004-01-01

    Efforts to implement new water quality standards, increase water reuse and reclamation, and minimize the cost of waste storage motivate the development of new processes for stabilizing wastewater residuals that minimize waste volume, water content and the long-term environmental risk from related by-products. This work explores the use of an aqueous-based emulsion process to create an epoxy/rubber matrix for separating and encapsulating waste components from salt laden, arsenic contaminated, amorphous iron hydrate sludges. Such sludges are generated from conventional water purification precipitation/adsorption processes, used to convert aqueous brine streams to semi-solid waste streams, such as ion exchange/membrane separation, and from other precipitative heavy metal removal operations. In this study, epoxy and polystyrene butadiene (PSB) rubber emulsions are mixed together and then combined with a surrogate sludge. The surrogate sludge consists of amorphous iron hydrate with 1 part arsenic fixed to the surface of the hydrate per 10 parts iron mixed with sodium nitrate and chloride salts and water. The resulting emulsion is cured and dried at 80 °C to remove water. Microstructure characterization by electron microscopy confirms that the epoxy/PSB matrix surrounds and encapsulates the arsenic laden amorphous iron hydrate phase while allowing the salt to migrate to internal and external surfaces of the sample. Salt extraction studies indicate that the porous nature of the resulting matrix promotes the separation and removal of as much as 90% of the original salt content in only one hour. Long term leaching studies based on the use of the infinite slab diffusion model reveal no evidence of iron migration or, by inference, arsenic migration, and demonstrate that the diffusion coefficients of the unextracted salt yield leachability indices within regulations for non-hazardous landfill disposal. Because salt is the most mobile species, it is inferred that arsenic

  19. DNA separation and fluorescent detection in an optofluidic chip with sub-base-pair resolution

    NASA Astrophysics Data System (ADS)

    Pollnau, Markus; Hammer, Manfred; Dongre, Chaitanya; Hoekstra, Hugo J.

    2015-03-01

    DNA sequencing in a lab-on-a-chip aims at providing cheap, high-speed analysis of low reagent volumes to, e.g., identify genomic deletions or insertions associated with genetic illnesses. Detecting single base-pair insertions/deletions from DNA fragments in the diagnostically relevant range of 150-1000 base-pairs requires a sizing accuracy of S < 10-3. Here we demonstrate S = 4×10-4. A microfluidic chip was post-processed by femtosecond-laser writing of an optical waveguide. 12 blue-labeled and 23 red-labeled DNA fragments were separated in size by capillary electrophoresis, each set excited by either of two lasers power-modulated at different frequencies, their fluorescence detected by a photomultiplier, and blue/red signals distinguished by Fourier analysis. Different calibration strategies were tested: a) use either set of DNA molecules as reference to calibrate the set-up and identify the base-pair sizes of the other set in the same flow experiment, thereby eliminating variations in temperature, wall-coating and sieving-gel conditions, and actuation voltages; b) use the same molecular set as reference and sample with the same fluorescence label, flown in consecutive experiments; c) perform cross-experiments based on different molecular sets with different labels, flown in consecutive experiments. From the results we conclude: Applying quadratic instead of linear fit functions improves the calibration accuracy. Blue-labeled molecules are separated with higher accuracy. The influence of dye label is higher than fluctuations between two experiments. Choosing a single, suitable dye label combined with reference calibration and sample investigation in consecutive experiments results in S = 4×10-4, enabling detection of single base-pair insertion/deletion in a lab-on-a-chip.

  20. Combination of three-stage sink-float method and selective flotation technique for separation of mixed post-consumer plastic waste.

    PubMed

    Pongstabodee, Sangobtip; Kunachitpimol, Napatr; Damronglerd, Somsak

    2008-01-01

    The aim of this research was to separate the different plastics of a mixed post-consumer plastic waste by the combination of a three-stage sink-float method and selective flotation. By using the three-stage sink-float method, six mixed-plastic wastes, belonging to the 0.3-0.5 cm size class and including high density polyethylene (HDPE), polypropylene (PP), polyvinylchloride (PVC), polystyrene (PS), polyethylene terephthalate (PET) and acrylonitrile-butadiene-styrene copolymers (ABS) were separated into two groups, i.e., a low density plastic group (HDPE and PP) and a high density plastic group (PET, PVC, PS and ABS) by tap water. Plastic whose density is less than that of the medium solution floats to the surface, while the one whose density is greater than that of the medium solution sinks to the bottom. The experimental results elucidated that complete separation of HDPE from PP was achieved by the three-stage sink-float method with 50% v/v ethyl alcohol. To succeed in the separation of a PS/ABS mixture from a PET/PVC mixture by the three-stage sink-float method, a 30% w/v calcium chloride solution was employed. To further separate post-consumer PET/PVC and PS/ABS based on plastic type, selective flotation was carried out. In order to succeed in selective flotation separation, it is necessary to render hydrophilic the surface of one or more species while the others are kept in a hydrophobic state. In flotation studies, the effects of wetting agent, frother, pH of solution and electrolyte on separation were determined. The selective flotation results showed that when using 500 mg l(-1) calcium lignosulfonate, 0.01 ppm MIBC, and 0.1 mg l(-1) CaCl2 at pH 11, PET could be separated from PVC. To separate ABS from PS, 200 mg l(-1) calcium lignosulfonate and 0.1 mg l(-1) CaCl2 at pH 7 were used as a flotation solution. Wettability of plastic increases when adding CaCl2 and corresponds to a decrease in its contact angles and to a reduction in the recovery of plastic in

  1. Advanced SuperDARN meteor wind observations based on raw time series analysis technique

    NASA Astrophysics Data System (ADS)

    Tsutsumi, M.; Yukimatu, A. S.; Holdsworth, D. A.; Lester, M.

    2009-04-01

    The meteor observation technique based on SuperDARN raw time series analysis has been upgraded. This technique extracts meteor information as biproducts and does not degrade the quality of normal SuperDARN operations. In the upgrade the radar operating system (RADOPS) has been modified so that it can oversample every 15 km during the normal operations, which have a range resolution of 45 km. As an alternative method for better range determination a frequency domain interferometry (FDI) capability was also coded in RADOPS, where the operating radio frequency can be changed every pulse sequence. Test observations were conducted using the CUTLASS Iceland East and Finland radars, where oversampling and FDI operation (two frequencies separated by 3 kHz) were simultaneously carried out. Meteor ranges obtained in both ranging techniques agreed very well. The ranges were then combined with the interferometer data to estimate meteor echo reflection heights. Although there were still some ambiguities in the arrival angles of echoes because of the rather long antenna spacing of the interferometers, the heights and arrival angles of most of meteor echoes were more accurately determined than previously. Wind velocities were successfully estimated over the height range of 84 to 110 km. The FDI technique developed here can be further applied to the common SuperDARN operation, and study of fine horizontal structures of F region plasma irregularities is expected in the future.

  2. Enhancing the effectiveness of IST through risk-based techniques

    SciTech Connect

    Floyd, S.D.

    1996-12-01

    Current IST requirements were developed mainly through deterministic-based methods. While this approach has resulted in an adequate level of safety and reliability for pumps and valves, insights from probabilistic safety assessments suggest a better safety focus can be achieved at lower costs. That is, some high safety impact pumps and valves are currently not tested under the IST program and should be added, while low safety impact valves could be tested at significantly greater intervals than allowed by the current IST program. The nuclear utility industry, through the Nuclear Energy Institute (NEI), has developed a draft guideline for applying risk-based techniques to focus testing on those pumps and valves with a high safety impact while reducing test frequencies on low safety impact pumps and valves. The guideline is being validated through an industry pilot application program that is being reviewed by the U.S. Nuclear Regulatory Commission. NEI and the ASME maintain a dialogue on the two groups` activities related to risk-based IST. The presenter will provide an overview of the NEI guideline, discuss the methodological approach for applying risk-based technology to IST and provide the status of the industry pilot plant effort.

  3. Spiral microchannel with rectangular and trapezoidal cross-sections for size based particle separation

    PubMed Central

    Guan, Guofeng; Wu, Lidan; Bhagat, Ali Asgar; Li, Zirui; Chen, Peter C. Y.; Chao, Shuzhe; Ong, Chong Jin; Han, Jongyoon

    2013-01-01

    The paper reports a new method for three-dimensional observation of the location of focused particle streams along both the depth and width of the channel cross-section in spiral inertial microfluidic systems. The results confirm that particles are focused near the top and bottom walls of the microchannel cross-section, revealing clear insights on the focusing and separation mechanism. Based on this detailed understanding of the force balance, we introduce a novel spiral microchannel with a trapezoidal cross-section that generates stronger Dean vortices at the outer half of the channel. Experiments show that particles focusing in such device are sensitive to particle size and flow rate, and exhibits a sharp transition from the inner half to the outer half equilibrium positions at a size-dependent critical flow rate. As particle equilibration positions are well segregated based on different focusing mechanisms, a higher separation resolution is achieved over conventional spiral microchannels with rectangular cross-section. PMID:23502529

  4. Cell adhesion to proteins separated by lithium dodecyl sulfate-polyacrylamide gel electrophoresis and blotted onto a polyvinylidene difluoride membrane: a new cell-blotting technique.

    PubMed

    Seshi, B

    1994-12-02

    Cell blotting, although conceptually simple, has failed to achieve wide practical application. Described here is a new cell-blotting technique which involves cell adhesion to protein bands after separation by lithium dodecyl sulfate-polyacrylamide gel electrophoresis (LDS-PAGE) and blotting onto polyvinylidene difluoride (PVDF) membrane at 4 degrees C. Cell bands adherent on PVDF are detected using hematoxylin, or propidium iodide (PI) staining followed by viewing under ultraviolet (UV) light. The technique allows quick microscopic visualization of adherent cells composing the bands, without requiring clearing of the membrane. Representative cell adhesion proteins from different sources, i.e., plant lectins (e.g., phytohemagglutinin, PHA; concanavalin A, ConA; and wheat germ agglutinin, WGA); extracellular matrix (ECM) proteins; and integral membrane proteins (e.g., recombinant soluble vascular cell adhesion molecule-1, rs VCAM-1) were tested for cell binding by the new cell-blotting technique using human lymphoid progenitor (NALM-6) and myeloid progenitor (KG1a) cell lines. Cell adhesion proteins retained their adhesion function in all cases tested. Specificity of cell binding on PVDF blot was demonstrated by inhibition of cell adhesion to WGA protein bands using an appropriate sugar, i.e., N-acetyl D-glucosamine. The cell blotting assay was comparable in sensitivity to Coomassie blue staining of protein bands. The ability to conduct protein extraction, separation and blotting at low temperature avoids thermal denaturation, thereby preserving the adhesion properties of the proteins. The electrophoretic/blotting system has unique detergent removal/protein renaturation properties and the ability to preserve functionally active adhesion protein complexes. The cell-blotting technique described is sufficiently robust for routine application in the investigation of novel cell adhesion proteins.

  5. Separation of time-based and trial-based accounts of the partial reinforcement extinction effect.

    PubMed

    Bouton, Mark E; Woods, Amanda M; Todd, Travis P

    2014-01-01

    Two appetitive conditioning experiments with rats examined time-based and trial-based accounts of the partial reinforcement extinction effect (PREE). In the PREE, the loss of responding that occurs in extinction is slower when the conditioned stimulus (CS) has been paired with a reinforcer on some of its presentations (partially reinforced) instead of every presentation (continuously reinforced). According to a time-based or "time-accumulation" view (e.g., Gallistel and Gibbon, 2000), the PREE occurs because the organism has learned in partial reinforcement to expect the reinforcer after a larger amount of time has accumulated in the CS over trials. In contrast, according to a trial-based view (e.g., Capaldi, 1967), the PREE occurs because the organism has learned in partial reinforcement to expect the reinforcer after a larger number of CS presentations. Experiment 1 used a procedure that equated partially and continuously reinforced groups on their expected times to reinforcement during conditioning. A PREE was still observed. Experiment 2 then used an extinction procedure that allowed time in the CS and the number of trials to accumulate differentially through extinction. The PREE was still evident when responding was examined as a function of expected time units to the reinforcer, but was eliminated when responding was examined as a function of expected trial units to the reinforcer. There was no evidence that the animal responded according to the ratio of time accumulated during the CS in extinction over the time in the CS expected before the reinforcer. The results thus favor a trial-based account over a time-based account of extinction and the PREE. This article is part of a Special Issue entitled: Associative and Temporal Learning.

  6. A variation in the component separation technique that preserves linea semilunaris: a study in cadavers and a clinical case.

    PubMed

    Barbosa, Marcus Vinicius Jardini; Nahas, Fabio Xerfan; de Oliveira Filho, Renato Santos; Ayaviri, Natalia Alinda Montecinos; Novo, Neil Ferreira; Ferreira, Lydia Masako

    2010-03-01

    The purpose of this study is to evaluate and compare the effect of the incision of the external oblique aponeurosis along the semilunaris in amount of tension present after the undermining of the anterior rectus sheaths. Forty fresh adult cadavers were studied and divided into two groups: group A (n=20) and group B (n=20). Traction indexes were compared in three situations: (1) before any aponeurotic undermining (similar on both groups); (2) after incision and undermining of the anterior rectus sheaths (similar on both groups) and (3) group A: after undermining of the external oblique muscles with the incision of their aponeurosis along the semilunaris and group B: undermining of a continuous layer of the anterior rectus sheaths and the external oblique aponeurosis, after release of the lateral aspect of the rectus sheaths. Significance of differences was assessed using non-parametric tests. There was a significant tension reduction after each stage of dissection in both supra- and infra-umbilical levels and on both groups. Comparisons between groups A and B did not show statistically significant differences in all sites and stages of the dissections. Therefore, both techniques showed similar aponeurotic tension reduction after each stage of the dissections in cadavers.

  7. Boronic Acid-Based Approach for Separation and Immobilization of Glycoproteins and Its Application in Sensing

    PubMed Central

    Wang, Xiaojin; Xia, Ning; Liu, Lin

    2013-01-01

    Glycoproteins influence a broad spectrum of biological processes including cell-cell interaction, host-pathogen interaction, or protection of proteins against proteolytic degradation. The analysis of their glyco-structures and concentration levels are increasingly important in diagnosis and proteomics. Boronic acids can covalently react with cis-diols in the oligosaccharide chains of glycoproteins to form five- or six-membered cyclic esters. Based on this interaction, boronic acid-based ligands and materials have attracted much attention in both chemistry and biology as the recognition motif for enrichment and chemo/biosensing of glycoproteins in recent years. In this work, we reviewed the progress in the separation, immobilization and detection of glycoproteins with boronic acid-functionalized materials and addressed its application in sensing. PMID:24141187

  8. Deformability-based red blood cell separation in deterministic lateral displacement devices-A simulation study.

    PubMed

    Krüger, Timm; Holmes, David; Coveney, Peter V

    2014-09-01

    We show, via three-dimensional immersed-boundary-finite-element-lattice-Boltzmann simulations, that deformability-based red blood cell (RBC) separation in deterministic lateral displacement (DLD) devices is possible. This is due to the deformability-dependent lateral extension of RBCs and enables us to predict a priori which RBCs will be displaced in a given DLD geometry. Several diseases affect the deformability of human cells. Malaria-infected RBCs, for example, tend to become stiffer than their healthy counterparts. It is therefore desirable to design microfluidic devices which can detect diseases based on the cells' deformability fingerprint, rather than preparing samples using expensive and time-consuming biochemical preparation steps. Our findings should be helpful in the development of new methods for sorting cells and particles by deformability.

  9. A Novel Methodology for Metal Ion Separation Based on Molecularly Imprinting

    SciTech Connect

    Zuo, Xiaobin; Mosha, Donnati; Hassan, Mansour M.; Givens, Richard S.; Busch, Daryle H.

    2004-03-31

    The siderophore-based extraction of iron from the soil by bacteria is proposed as a model for a new separation methodology labeled the soil poutice, a molecular device that would selectively retrieve the complex of a targeted metal ion. In this report we described the synthesis and characterization of molecularly imprinted polymers and their application in the specific recognition of macrocyclic metal complexes. The imprinting is based on non-covalent interactions such as hydrogen bonding, electrostatic attractions and minor metal-ligand coordination. Good rebinding capacity for the imprinting metal complex was observed in acetonitrile as well as in water. The polymers are resistant to strong acids and oxidizing agents and showed an increase of rebinding capacity during cycles of reuse. The imprinting procedure, combined with the previously known selective chelation of macrocyclic ligands, supports the feasibility of a new methodology that can be used to extract waste metal ions effectively and selectively from soils and ground water.

  10. Polymeric nanopore membranes for hydrophobicity-based separations by conformal initiated chemical vapor deposition.

    PubMed

    Asatekin, Ayse; Gleason, Karen K

    2011-02-09

    High-aspect ratio hydrophobic, cylindrical nanopores having diameters as low as 5 nm are rapidly fabricated using conformal vapor deposition of fluorinated polymeric layers into porous track-etched polycarbonate membranes. The resultant selectivity of these membranes for pairs of small molecules of similar size, but of different hydrophobicity, arises from solute-pore wall interactions emphasized by confinement. Increasing selectivity was observed as pore diameter decreased and as the surface of the pore became more hydrophobic. Cylindrical pores provided higher selectivity than bottleneck-shaped pores having the same minimum diameter. A maximum selectivity of 234 was achieved between mesitylene and phloroglucinol by the best performing membrane. Membranes with small fluorinated pores exhibited an effective cutoff based on the polar surface area of the molecules, with limited correlation with solute size. This technology could lead to a new generation of membrane separations based on specific interactions.

  11. Actuator fault tolerant multi-controller scheme using set separation based diagnosis

    NASA Astrophysics Data System (ADS)

    Seron, María M.; De Doná, José A.

    2010-11-01

    We present a fault tolerant control strategy based on a new principle for actuator fault diagnosis. The scheme employs a standard bank of observers which match the different fault situations that can occur in the plant. Each of these observers has an associated estimation error with distinctive dynamics when an estimator matches the current fault situation of the plant. Based on the information from each observer, a fault detection and isolation (FDI) module is able to reconfigure the control loop by selecting the appropriate control law from a bank of controllers, each of them designed to stabilise and achieve reference tracking for one of the given fault models. The main contribution of this article is to propose a new FDI principle which exploits the separation of sets that characterise healthy system operation from sets that characterise transitions from healthy to faulty behaviour. The new principle allows to provide pre-checkable conditions for guaranteed fault tolerance of the overall multi-controller scheme.

  12. A New MRI-Based Pediatric Subcortical Segmentation Technique (PSST).

    PubMed

    Loh, Wai Yen; Connelly, Alan; Cheong, Jeanie L Y; Spittle, Alicia J; Chen, Jian; Adamson, Christopher; Ahmadzai, Zohra M; Fam, Lillian Gabra; Rees, Sandra; Lee, Katherine J; Doyle, Lex W; Anderson, Peter J; Thompson, Deanne K

    2016-01-01

    Volumetric and morphometric neuroimaging studies of the basal ganglia and thalamus in pediatric populations have utilized existing automated segmentation tools including FIRST (Functional Magnetic Resonance Imaging of the Brain's Integrated Registration and Segmentation Tool) and FreeSurfer. These segmentation packages, however, are mostly based on adult training data. Given that there are marked differences between the pediatric and adult brain, it is likely an age-specific segmentation technique will produce more accurate segmentation results. In this study, we describe a new automated segmentation technique for analysis of 7-year-old basal ganglia and thalamus, called Pediatric Subcortical Segmentation Technique (PSST). PSST consists of a probabilistic 7-year-old subcortical gray matter atlas (accumbens, caudate, pallidum, putamen and thalamus) combined with a customized segmentation pipeline using existing tools: ANTs (Advanced Normalization Tools) and SPM (Statistical Parametric Mapping). The segmentation accuracy of PSST in 7-year-old data was compared against FIRST and FreeSurfer, relative to manual segmentation as the ground truth, utilizing spatial overlap (Dice's coefficient), volume correlation (intraclass correlation coefficient, ICC) and limits of agreement (Bland-Altman plots). PSST achieved spatial overlap scores ≥90% and ICC scores ≥0.77 when compared with manual segmentation, for all structures except the accumbens. Compared with FIRST and FreeSurfer, PSST showed higher spatial overlap (p FDR  < 0.05) and ICC scores, with less volumetric bias according to Bland-Altman plots. PSST is a customized segmentation pipeline with an age-specific atlas that accurately segments typical and atypical basal ganglia and thalami at age 7 years, and has the potential to be applied to other pediatric datasets.

  13. Plasma and trap-based techniques for science with positrons

    NASA Astrophysics Data System (ADS)

    Danielson, J. R.; Dubin, D. H. E.; Greaves, R. G.; Surko, C. M.

    2015-01-01

    In recent years, there has been a wealth of new science involving low-energy antimatter (i.e., positrons and antiprotons) at energies ranging from 102 to less than 10-3 eV . Much of this progress has been driven by the development of new plasma-based techniques to accumulate, manipulate, and deliver antiparticles for specific applications. This article focuses on the advances made in this area using positrons. However, many of the resulting techniques are relevant to antiprotons as well. An overview is presented of relevant theory of single-component plasmas in electromagnetic traps. Methods are described to produce intense sources of positrons and to efficiently slow the typically energetic particles thus produced. Techniques are described to trap positrons efficiently and to cool and compress the resulting positron gases and plasmas. Finally, the procedures developed to deliver tailored pulses and beams (e.g., in intense, short bursts, or as quasimonoenergetic continuous beams) for specific applications are reviewed. The status of development in specific application areas is also reviewed. One example is the formation of antihydrogen atoms for fundamental physics [e.g., tests of invariance under charge conjugation, parity inversion, and time reversal (the CPT theorem), and studies of the interaction of gravity with antimatter]. Other applications discussed include atomic and materials physics studies and the study of the electron-positron many-body system, including both classical electron-positron plasmas and the complementary quantum system in the form of Bose-condensed gases of positronium atoms. Areas of future promise are also discussed. The review concludes with a brief summary and a list of outstanding challenges.

  14. Detecting Molecular Properties by Various Laser-Based Techniques

    SciTech Connect

    Hsin, Tse-Ming

    2007-01-01

    Four different laser-based techniques were applied to study physical and chemical characteristics of biomolecules and dye molecules. These techniques are liole burning spectroscopy, single molecule spectroscopy, time-resolved coherent anti-Stokes Raman spectroscopy and laser-induced fluorescence microscopy. Results from hole burning and single molecule spectroscopy suggested that two antenna states (C708 & C714) of photosystem I from cyanobacterium Synechocystis PCC 6803 are connected by effective energy transfer and the corresponding energy transfer time is ~6 ps. In addition, results from hole burning spectroscopy indicated that the chlorophyll dimer of the C714 state has a large distribution of the dimer geometry. Direct observation of vibrational peaks and evolution of coumarin 153 in the electronic excited state was demonstrated by using the fs/ps CARS, a variation of time-resolved coherent anti-Stokes Raman spectroscopy. In three different solvents, methanol, acetonitrile, and butanol, a vibration peak related to the stretch of the carbonyl group exhibits different relaxation dynamics. Laser-induced fluorescence microscopy, along with the biomimetic containers-liposomes, allows the measurement of the enzymatic activity of individual alkaline phosphatase from bovine intestinal mucosa without potential interferences from glass surfaces. The result showed a wide distribution of the enzyme reactivity. Protein structural variation is one of the major reasons that are responsible for this highly heterogeneous behavior.

  15. Model-checking techniques based on cumulative residuals.

    PubMed

    Lin, D Y; Wei, L J; Ying, Z

    2002-03-01

    Residuals have long been used for graphical and numerical examinations of the adequacy of regression models. Conventional residual analysis based on the plots of raw residuals or their smoothed curves is highly subjective, whereas most numerical goodness-of-fit tests provide little information about the nature of model misspecification. In this paper, we develop objective and informative model-checking techniques by taking the cumulative sums of residuals over certain coordinates (e.g., covariates or fitted values) or by considering some related aggregates of residuals, such as moving sums and moving averages. For a variety of statistical models and data structures, including generalized linear models with independent or dependent observations, the distributions of these stochastic processes tinder the assumed model can be approximated by the distributions of certain zero-mean Gaussian processes whose realizations can be easily generated by computer simulation. Each observed process can then be compared, both graphically and numerically, with a number of realizations from the Gaussian process. Such comparisons enable one to assess objectively whether a trend seen in a residual plot reflects model misspecification or natural variation. The proposed techniques are particularly useful in checking the functional form of a covariate and the link function. Illustrations with several medical studies are provided.

  16. Investigations on landmine detection by neutron-based techniques.

    PubMed

    Csikai, J; Dóczi, R; Király, B

    2004-07-01

    Principles and techniques of some neutron-based methods used to identify the antipersonnel landmines (APMs) are discussed. New results have been achieved in the field of neutron reflection, transmission, scattering and reaction techniques. Some conclusions are as follows: The neutron hand-held detector is suitable for the observation of anomaly caused by a DLM2-like sample in different soils with a scanning speed of 1m(2)/1.5 min; the reflection cross section of thermal neutrons rendered the determination of equivalent thickness of different soil components possible; a simple method was developed for the determination of the thermal neutron flux perturbation factor needed for multi-elemental analysis of bulky samples; unfolded spectra of elastically backscattered neutrons using broad-spectrum sources render the identification of APMs possible; the knowledge of leakage spectra of different source neutrons is indispensable for the determination of the differential and integrated reaction rates and through it the dimension of the interrogated volume; the precise determination of the C/O atom fraction requires the investigations on the angular distribution of the 6.13MeV gamma-ray emitted in the (16)O(n,n'gamma) reaction. These results, in addition to the identification of landmines, render the improvement of the non-intrusive neutron methods possible.

  17. Background correction in separation techniques hyphenated to high-resolution mass spectrometry - Thorough correction with MS scans recorded as profile spectra.

    PubMed

    Erny, Guillaume L; Acunha, Tanize; Simó, Carolina; Cifuentes, Alejandro; Alves, Arminda

    2017-03-01

    Separation techniques hyphenated with high-resolution mass spectrometry have been a true revolution in analytical separation techniques. Such instruments not only provide unmatched resolution, but they also allow measuring the peaks accurate masses that permit identifying monoisotopic formulae. However, data files can be large, with a major contribution from background noise and background ions. Such unnecessary contribution to the overall signal can hide important features as well as decrease the accuracy of the centroid determination, especially with minor features. Thus, noise and baseline correction can be a valuable pre-processing step. The methodology that is described here, unlike any other approach, is used to correct the original dataset with the MS scans recorded as profiles spectrum. Using urine metabolic studies as examples, we demonstrate that this thorough correction reduces the data complexity by more than 90%. Such correction not only permits an improved visualisation of secondary peaks in the chromatographic domain, but it also facilitates the complete assignment of each MS scan which is invaluable to detect possible comigration/coeluting species.

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

    NASA Astrophysics Data System (ADS)

    Shan, Wenqian

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

  19. Validation techniques for fault emulation of SRAM-based FPGAs

    DOE PAGES

    Quinn, Heather; Wirthlin, Michael

    2015-08-07

    A variety of fault emulation systems have been created to study the effect of single-event effects (SEEs) in static random access memory (SRAM) based field-programmable gate arrays (FPGAs). These systems are useful for augmenting radiation-hardness assurance (RHA) methodologies for verifying the effectiveness for mitigation techniques; understanding error signatures and failure modes in FPGAs; and failure rate estimation. For radiation effects researchers, it is important that these systems properly emulate how SEEs manifest in FPGAs. If the fault emulation systems does not mimic the radiation environment, the system will generate erroneous data and incorrect predictions of behavior of the FPGA inmore » a radiation environment. Validation determines whether the emulated faults are reasonable analogs to the radiation-induced faults. In this study we present methods for validating fault emulation systems and provide several examples of validated FPGA fault emulation systems.« less

  20. Validation techniques for fault emulation of SRAM-based FPGAs

    SciTech Connect

    Quinn, Heather; Wirthlin, Michael

    2015-08-07

    A variety of fault emulation systems have been created to study the effect of single-event effects (SEEs) in static random access memory (SRAM) based field-programmable gate arrays (FPGAs). These systems are useful for augmenting radiation-hardness assurance (RHA) methodologies for verifying the effectiveness for mitigation techniques; understanding error signatures and failure modes in FPGAs; and failure rate estimation. For radiation effects researchers, it is important that these systems properly emulate how SEEs manifest in FPGAs. If the fault emulation systems does not mimic the radiation environment, the system will generate erroneous data and incorrect predictions of behavior of the FPGA in a radiation environment. Validation determines whether the emulated faults are reasonable analogs to the radiation-induced faults. In this study we present methods for validating fault emulation systems and provide several examples of validated FPGA fault emulation systems.

  1. Diagnosis of Dengue Infection Using Conventional and Biosensor Based Techniques

    PubMed Central

    Parkash, Om; Hanim Shueb, Rafidah

    2015-01-01

    Dengue is an arthropod-borne viral disease caused by four antigenically different serotypes of dengue virus. This disease is considered as a major public health concern around the world. Currently, there is no licensed vaccine or antiviral drug available for the prevention and treatment of dengue disease. Moreover, clinical features of dengue are indistinguishable from other infectious diseases such as malaria, chikungunya, rickettsia and leptospira. Therefore, prompt and accurate laboratory diagnostic test is urgently required for disease confirmation and patient triage. The traditional diagnostic techniques for the dengue virus are viral detection in cell culture, serological testing, and RNA amplification using reverse transcriptase PCR. This paper discusses the conventional laboratory methods used for the diagnosis of dengue during the acute and convalescent phase and highlights the advantages and limitations of these routine laboratory tests. Subsequently, the biosensor based assays developed using various transducers for the detection of dengue are also reviewed. PMID:26492265

  2. Mars laser altimeter based on a single photon ranging technique

    NASA Technical Reports Server (NTRS)

    Prochazka, Ivan; Hamal, Karel; Sopko, B.; Pershin, S.

    1993-01-01

    The Mars 94/96 Mission will carry, among others things, the balloon probe experiment. The balloon with the scientific cargo in the gondola underneath will drift in the Mars atmosphere, its altitude will range from zero, in the night, up to 5 km at noon. The accurate gondola altitude will be determined by an altimeter. As the Balloon gondola mass is strictly limited, the altimeter total mass and power consumption are critical; maximum allowed is a few hundred grams a few tens of mWatts of average power consumption. We did propose, design, and construct the laser altimeter based on the single photon ranging technique. Topics covered include the following: principle of operation, altimeter construction, and ground tests.

  3. Diagnosis of Dengue Infection Using Conventional and Biosensor Based Techniques.

    PubMed

    Parkash, Om; Shueb, Rafidah Hanim

    2015-10-19

    Dengue is an arthropod-borne viral disease caused by four antigenically different serotypes of dengue virus. This disease is considered as a major public health concern around the world. Currently, there is no licensed vaccine or antiviral drug available for the prevention and treatment of dengue disease. Moreover, clinical features of dengue are indistinguishable from other infectious diseases such as malaria, chikungunya, rickettsia and leptospira. Therefore, prompt and accurate laboratory diagnostic test is urgently required for disease confirmation and patient triage. The traditional diagnostic techniques for the dengue virus are viral detection in cell culture, serological testing, and RNA amplification using reverse transcriptase PCR. This paper discusses the conventional laboratory methods used for the diagnosis of dengue during the acute and convalescent phase and highlights the advantages and limitations of these routine laboratory tests. Subsequently, the biosensor based assays developed using various transducers for the detection of dengue are also reviewed.

  4. Phase-based cell imaging techniques for microbeam irradiations

    NASA Astrophysics Data System (ADS)

    Ross, G. J.; Bigelow, A. W.; Randers–Pehrson, G.; Peng, C. C.; Brenner, D. J.

    2005-12-01

    The microbeam facility at Columbia University is expanding current protocols for single-particle, single-cell irradiations, so experimenters can locate and irradiate nuclei and cytoplasm of unstained cells. The ion beamline is located directly under the dish, therefore, any new techniques must use reflection microscopy. Two approaches are being integrated and neither require the removal of the cell growth medium prior to irradiation. A novel immersion-based Mirau interferometry lens which uses low-coherence light sources to inhibit unwanted fringing is under design. The process requires tens of nanometers or better precision of vertical stage motion, which will be accomplished with our custom high-precision z-stage. Quantitative Phase microscopy is under testing, also using the z-stage. Future plans include optimization of software routines to decrease time between irradiations. Both methods will be compared further with the automated location routines which use nuclear and cytoplasm stains.

  5. Ionospheric Plasma Drift Analysis Technique Based On Ray Tracing

    NASA Astrophysics Data System (ADS)

    Ari, Gizem; Toker, Cenk

    2016-07-01

    Ionospheric drift measurements provide important information about the variability in the ionosphere, which can be used to quantify ionospheric disturbances caused by natural phenomena such as solar, geomagnetic, gravitational and seismic activities. One of the prominent ways for drift measurement depends on instrumentation based measurements, e.g. using an ionosonde. The drift estimation of an ionosonde depends on measuring the Doppler shift on the received signal, where the main cause of Doppler shift is the change in the length of the propagation path of the signal between the transmitter and the receiver. Unfortunately, ionosondes are expensive devices and their installation and maintenance require special care. Furthermore, the ionosonde network over the world or even Europe is not dense enough to obtain a global or continental drift map. In order to overcome the difficulties related to an ionosonde, we propose a technique to perform ionospheric drift estimation based on ray tracing. First, a two dimensional TEC map is constructed by using the IONOLAB-MAP tool which spatially interpolates the VTEC estimates obtained from the EUREF CORS network. Next, a three dimensional electron density profile is generated by inputting the TEC estimates to the IRI-2015 model. Eventually, a close-to-real situation electron density profile is obtained in which ray tracing can be performed. These profiles can be constructed periodically with a period of as low as 30 seconds. By processing two consequent snapshots together and calculating the propagation paths, we estimate the drift measurements over any coordinate of concern. We test our technique by comparing the results to the drift measurements taken at the DPS ionosonde at Pruhonice, Czech Republic. This study is supported by TUBITAK 115E915 and Joint TUBITAK 114E092 and AS CR14/001 projects.

  6. Chelating fibers prepared with a wet spinning technique using a mixture of a viscose solution and a polymer ligand for the separation of metal ions in an aqueous solution.

    PubMed

    Kagaya, Shigehiro; Miyazaki, Hiroyuki; Inoue, Yoshinori; Kato, Toshifumi; Yanai, Hideyuki; Kamichatani, Waka; Kajiwara, Takehiro; Saito, Mitsuru; Tohda, Koji

    2012-02-15

    Chelating fibers containing polymer ligands such as carboxymethylated polyallylamine, carboxymethylated polyethyleneimine, and a copolymer of diallylamine hydrochloride/maleic acid were prepared with a wet spinning technique using mixtures of a viscose solution and the polymer ligands. The chelating fibers obtained effectively adsorbed various metal ions, including Cd(II), Co(II), Cr(III), Cu(II), Fe(III), Mn(II), Ni(II), Pb(II), Ti(IV), and Zn(II). The metal ions adsorbed could be readily desorbed using 0.1 or 0.5 mol L(-1) HNO(3). The chelating fiber containing carboxymethylated polyallylamine was available for the separation of some metal ions in synthetic wastewater containing a large amount of Na(2)SO(4). The wet spinning technique using a solution containing a base polymer and a polymer ligand was quite simple and effective and would be applicable for preparing various chelating fibers.

  7. A review of exosome separation techniques and characterization of B16-F10 mouse melanoma exosomes with AF4-UV-MALS-DLS-TEM.

    PubMed

    Petersen, Kevin E; Manangon, Eliana; Hood, Joshua L; Wickline, Samuel A; Fernandez, Diego P; Johnson, William P; Gale, Bruce K

    2014-12-01

    Exosomes participate in cancer metastasis, but studying them presents unique challenges as a result of their small size and purification difficulties. Asymmetrical field flow fractionation with in-line ultraviolet absorbance, dynamic light scattering, and multi-angle light scattering was applied to the size separation and characterization of non-labeled B16-F10 exosomes from an aggressive mouse melanoma cell culture line. Fractions were collected and further analyzed using batch mode dynamic light scattering, transmission electron microscopy and compared with known size standards. Fractogram peak positions and computed radii show good agreement between samples and across fractions. Ultraviolet absorbance fractograms in combination with transmission electron micrographs were able to resolve subtle heterogeneity of vesicle retention times between separate batches of B16-F10 exosomes collected several weeks apart. Further, asymmetrical field flow fractionation also effectively separated B16-F10 exosomes into vesicle subpopulations by size. Overall, the flow field flow fractionation instrument combined with multiple detectors was able to rapidly characterize and separate exosomes to a degree not previously demonstrated. These approaches have the potential to facilitate a greater understanding of exosome function by subtype, as well as ultimately allow for "label-free" isolation of large scale clinical exosomes for the purpose of developing future exosome-based diagnostics and therapeutics.

  8. Wavelet-based fMRI analysis: 3-D denoising, signal separation, and validation metrics.

    PubMed

    Khullar, Siddharth; Michael, Andrew; Correa, Nicolle; Adali, Tulay; Baum, Stefi A; Calhoun, Vince D

    2011-02-14

    We present a novel integrated wavelet-domain based framework (w-ICA) for 3-D denoising functional magnetic resonance imaging (fMRI) data followed by source separation analysis using independent component analysis (ICA) in the wavelet domain. We propose the idea of a 3-D wavelet-based multi-directional denoising scheme where each volume in a 4-D fMRI data set is sub-sampled using the axial, sagittal and coronal geometries to obtain three different slice-by-slice representations of the same data. The filtered intensity value of an arbitrary voxel is computed as an expected value of the denoised wavelet coefficients corresponding to the three viewing geometries for each sub-band. This results in a robust set of denoised wavelet coefficients for each voxel. Given the de-correlated nature of these denoised wavelet coefficients, it is possible to obtain more accurate source estimates using ICA in the wavelet domain. The contributions of this work can be realized as two modules: First, in the analysis module we combine a new 3-D wavelet denoising approach with signal separation properties of ICA in the wavelet domain. This step helps obtain an activation component that corresponds closely to the true underlying signal, which is maximally independent with respect to other components. Second, we propose and describe two novel shape metrics for post-ICA comparisons between activation regions obtained through different frameworks. We verified our method using simulated as well as real fMRI data and compared our results against the conventional scheme (Gaussian smoothing+spatial ICA: s-ICA). The results show significant improvements based on two important features: (1) preservation of shape of the activation region (shape metrics) and (2) receiver operating characteristic curves. It was observed that the proposed framework was able to preserve the actual activation shape in a consistent manner even for very high noise levels in addition to significant reduction in false

  9. Preparations of PAN-based adsorbers for separation of cesium and cobalt from radioactive wastes.

    PubMed

    Nilchi, A; Atashi, H; Javid, A H; Saberi, R

    2007-05-01

    Ion-exchange adsorbers are widely used for radioisotope separation, as well as for the removal of hazardous fission products from aqueous waste prior to discharge to the environment. Inorganic exchangers are of particular interest because of their resistance to radiolytic damage and selectivity for specific fission products. Composite inorganic-organic adsorbers represent a group of inorganic ion exchangers modified by using binding organic material, polyacrylonitrile, for preparation of larger size particles with higher granular strength. At the same time, kinetics of ion exchange and sorption capacity of such composite adsorbers are not influenced by the binding polymer. The contents of active component in composite adsorber were varied over a very broad range of 5-95% of the dry weight of the composite adsorber, and tested for separation and concentration of various stimulated wastes. Three different inorganic sorbents, granular hexacyanoferrate-based ion exchanger, were developed for the removal of Cs and Co ions from waste solutions containing different complexing agents as detergents. Radiation and thermal stability studies show that these adsorbents can be used for medium-active waste treatment.

  10. Adsorption mechanism-based screening of cyclodextrin polymers for adsorption and separation of pesticides from water.

    PubMed

    Liu, Huihui; Cai, Xiyun; Wang, Yu; Chen, Jingwen

    2011-05-01

    A rational screening of cyclodextrin-based polymer (CDP), in terms of the relationship between adsorption potential and adsorbent-adsorbate, was investigated to adsorb and separate pesticides from water. Seven spherical porous CDPs were prepared with onefold or composite cyclodextrin(s) as complex and epichlorohydrin as cross-linking reagent. The adsorption kinetics and isotherms of the polymers toward a mixture of ten distinct pesticides clearly demonstrate that the adsorbents with a homogeneous open network structure can absorb pesticides via multiple adsorption interactions such as CD inclusion, loading into swelling water and physical adsorption on network. The multivariate regression analysis distinguishes the quantitative contributions of polymer properties to its adsorption potential, among which CD content, swelling capacity and pore size appear to be major influencing factors. Consequently, a facile mixture of three CDPs (i.e., β-CDP, RM-CDP and HP-CDP) was screened to obtain above prerequisite properties. The multiplex polymer could superiorly separate the pesticides at environmentally relevant levels from water.

  11. A lab-on-a-chip for monolith-based preconcentration and electrophoresis separation of phosphopeptides.

    PubMed

    Araya-Farias, Monica; Dziomba, Szymon; Carbonnier, Benjamin; Guerrouache, Mohamed; Ayed, Ichraf; Aboud, Nacera; Taverna, Myriam; Tran, N Thuy

    2017-01-26

    A microdevice combining online preconcentration and separation of phosphopeptides was developed in a glass microchip. An ethylene glycol methacrylate phosphate (EGMP), acrylamide (AM) and bisacrylamide (BAA) based monolith was synthesized within microchannels through a photo-driven process. Morphological investigations revealed a homogeneous monolithic structure composed of uniform nodules (∼0.8 μm), with a large pore volume (0.62 cm(3) g(-1)) and sufficiently high specific surface area (34.1 m(2) g(-1)). These features make the monolith particularly interesting for preconcentration purposes. Immobilization of Zr(4+) ions on the phosphate groups present at the poly(EGMP-co-AM-co-BAA) monolith surface leads to immobilized metal affinity chromatography support. This monolith-Zr(4+) showed a great capacity to capture phosphopeptides. Successful preconcentration and separation of a mixture of ERK2 derived peptides differing only by their phosphorylation degree and sites could be achieved with signal enhancement factors between 340 and 910 after only 7 min of preconcentration. This integrated microdevice represents a novel approach for phosphoproteomic applications.

  12. Rapid Filtration Separation-Based Sample Preparation Method for Bacillus Spores in Powdery and Environmental Matrices

    PubMed Central

    Isabel, Sandra; Boissinot, Maurice; Charlebois, Isabelle; Fauvel, Chantal M.; Shi, Lu-E; Lévesque, Julie-Christine; Paquin, Amélie T.; Bastien, Martine; Stewart, Gale; Leblanc, Éric; Sato, Sachiko

    2012-01-01

    Authorities frequently need to analyze suspicious powders and other samples for biothreat agents in order to assess environmental safety. Numerous nucleic acid detection technologies have been developed to detect and identify biowarfare agents in a timely fashion. The extraction of microbial nucleic acids from a wide variety of powdery and environmental samples to obtain a quality level adequate for these technologies still remains a technical challenge. We aimed to develop a rapid and versatile method of separating bacteria from these samples and then extracting their microbial DNA. Bacillus atrophaeus subsp. globigii was used as a simulant of Bacillus anthracis. We studied the effects of a broad variety of powdery and environmental samples on PCR detection and the steps required to alleviate their interference. With a benchmark DNA extraction procedure, 17 of the 23 samples investigated interfered with bacterial lysis and/or PCR-based detection. Therefore, we developed the dual-filter method for applied recovery of microbial particles from environmental and powdery samples (DARE). The DARE procedure allows the separation of bacteria from contaminating matrices that interfere with PCR detection. This procedure required only 2 min, while the DNA extraction process lasted 7 min, for a total of <10 min. This sample preparation procedure allowed the recovery of cleaned bacterial spores and relieved detection interference caused by a wide variety of samples. Our procedure was easily completed in a laboratory facility and is amenable to field application and automation. PMID:22210204

  13. Novel electrode structures for large scale dielectrophoretic separations based on textile technology.

    PubMed

    Abidin, Zurina Z; Downes, Les; Markx, Gerard H

    2007-06-15

    The use of dielectrophoresis (DEP) to date has mainly been limited to processing small volumes due to difficulties in the fabrication of microelectrodes over large surface areas. To overcome this problem a novel approach to the construction of micro-electrode arrays has been developed based on weaving. A plain weave cloth was made from 100 microm diameter stainless steel wires and 75 decitex polyester yarns. The stainless steel wires formed the weft, and were kept parallel and apart by a warp of flexible polyester yarns, with a gap of around 150 microm between the metal wires. The metal wires were alternately connected to earth and signal of an AC power source, and it was shown that it was possible to collect yeast cells suspended in deionised water at the metal wire surfaces by dielectrophoresis. The polyester yarn was also found to distort the electric field, creating further areas of electric field non-uniformity around the polyester yarns, further enhancing the capability of the system to attract cells. A 14 ml separation chamber was built from the cloth by alternately sandwiching perspex slabs and cloth together. The DEP chamber was able to effectively collect life yeast from a flow of suspended cells through the cloth using an applied field of 1 MHz at flow rates up to 5 ml min-1. However, some loss occurred due to sedimentation. Also, the chamber was able to separate dead and live yeast cells at 30 Vpk-pk, 2 MHz, with some cell loss due to sedimentation.

  14. Rapid filtration separation-based sample preparation method for Bacillus spores in powdery and environmental matrices.

    PubMed

    Isabel, Sandra; Boissinot, Maurice; Charlebois, Isabelle; Fauvel, Chantal M; Shi, Lu-E; Lévesque, Julie-Christine; Paquin, Amélie T; Bastien, Martine; Stewart, Gale; Leblanc, Eric; Sato, Sachiko; Bergeron, Michel G

    2012-03-01

    Authorities frequently need to analyze suspicious powders and other samples for biothreat agents in order to assess environmental safety. Numerous nucleic acid detection technologies have been developed to detect and identify biowarfare agents in a timely fashion. The extraction of microbial nucleic acids from a wide variety of powdery and environmental samples to obtain a quality level adequate for these technologies still remains a technical challenge. We aimed to develop a rapid and versatile method of separating bacteria from these samples and then extracting their microbial DNA. Bacillus atrophaeus subsp. globigii was used as a simulant of Bacillus anthracis. We studied the effects of a broad variety of powdery and environmental samples on PCR detection and the steps required to alleviate their interference. With a benchmark DNA extraction procedure, 17 of the 23 samples investigated interfered with bacterial lysis and/or PCR-based detection. Therefore, we developed the dual-filter method for applied recovery of microbial particles from environmental and powdery samples (DARE). The DARE procedure allows the separation of bacteria from contaminating matrices that interfere with PCR detection. This procedure required only 2 min, while the DNA extraction process lasted 7 min, for a total of <10 min. This sample preparation procedure allowed the recovery of cleaned bacterial spores and relieved detection interference caused by a wide variety of samples. Our procedure was easily completed in a laboratory facility and is amenable to field application and automation.

  15. Phosphonium-based ionic liquids in electrokinetic capillary chromatography for the separation of neutral analytes.

    PubMed

    Wiedmer, Susanne K; King, Alistair W T; Riekkola, Marja-Liisa

    2012-08-31

    In this work we elucidated the applicability of phosphonium-based ionic liquids (ILs) as pseudostationary phase in electrokinetic capillary chromatography (EKC) with UV-detection. The phosphonium ILs studied contain bromide, chlorine, or tosylate ions, as counter ions, and alkyl side chains of variable length on the phosphorous atom. The effects of the type and concentration of the IL, pH, ionic strength, and type of background electrolyte solution on the electroosmotic flow (EOF) and on the effective electrophoretic mobilities of some neutral model analytes were investigated and large variations in the migration times were observed. Especially the IL employed remarkably affected the strength and direction of the EOF Successful separations were obtained for neutral aromatic singly substituted analytes, namely benzene, toluene, phenol, and nitrobenzene. The results demonstrated the potential of capillary electromigration methods for rapid interaction studies between ILs and analytes, which is useful for the development of novel materials for sample preparation and separation purposes or for novel catalyst and chemical processing studies.

  16. Indications and Outcomes of the Components Separation Technique in the Repair of Complex Abdominal Wall Hernias: Experience From the Cambridge Plastic Surgery Department

    PubMed Central

    Adekunle, Shola; Pantelides, Nicholas M.; Hall, Nigel R.; Praseedom, Raaj; Malata, Charles M.

    2013-01-01

    Objectives: The components separation technique (CST) is a widely described abdominal wall reconstructive technique. There have, however, been no UK reports of its use, prompting the present review. Methods: Between 2008 and 2012, 13 patients who underwent this procedure by a single plastic surgeon (C.M.M.) were retrospectively evaluated. The indications, operative details, and clinical outcomes were recorded. Results: There were 7 women and 6 men in the series with a mean age of 53 years (range: 30-80). Patients were referred from a variety of specialties, often as a last resort. The commonest indication for CST was herniation following abdominal surgery. All operations except 1 were jointly performed with general surgeons (for bowel resection, stoma reversal, and hernia dissection). The operations lasted a mean of 5 hours (range: 3-8 hours). There were no major intra- and postoperative problems, except in 1 patient who developed intra-abdominal compartment syndrome, secondary to massive hemorrhage. All patients were satisfied with the cosmetic improvement in their abdominal contours. None of the patients have developed a clinical recurrence after a mean follow-up of 16 months (range: 3-38 months). Conclusions: The components separation technique is an effective method of treating large recalcitrant hernias but appears to be underutilized in the United Kingdom. The management of large abdominal wall defects requires a multidisciplinary approach, with input across a variety of specialities. Liaison with plastic surgery teams should be encouraged at an early stage and the CST should be more widely considered when presented with seemingly intractable abdominal wall defects. PMID:24058718

  17. Skull base tumours part I: imaging technique, anatomy and anterior skull base tumours.

    PubMed

    Borges, Alexandra

    2008-06-01

    Advances in cross-sectional imaging, surgical technique and adjuvant treatment have largely contributed to ameliorate the prognosis, lessen the morbidity and mortality of patients with skull base tumours and to the growing medical investment in the management of these patients. Because clinical assessment of the skull base is limited, cross-sectional imaging became indispensable in the diagnosis, treatment planning and follow-up of patients with suspected skull base pathology and the radiologist is increasingly responsible for the fate of these patients. This review will focus on the advances in imaging technique; contribution to patient's management and on the imaging features of the most common tumours affecting the anterior skull base. Emphasis is given to a systematic approach to skull base pathology based upon an anatomic division taking into account the major tissue constituents in each skull base compartment. The most relevant information that should be conveyed to surgeons and radiation oncologists involved in patient's management will be discussed.

  18. Damage detection technique by measuring laser-based mechanical impedance

    SciTech Connect

    Lee, Hyeonseok; Sohn, Hoon

    2014-02-18

    This study proposes a method for measurement of mechanical impedance using noncontact laser ultrasound. The measurement of mechanical impedance has been of great interest in nondestructive testing (NDT) or structural health monitoring (SHM) since mechanical impedance is sensitive even to small-sized structural defects. Conventional impedance measurements, however, have been based on electromechanical impedance (EMI) using contact-type piezoelectric transducers, which show deteriorated performances induced by the effects of a) Curie temperature limitations, b) electromagnetic interference (EMI), c) bonding layers and etc. This study aims to tackle the limitations of conventional EMI measurement by utilizing laser-based mechanical impedance (LMI) measurement. The LMI response, which is equivalent to a steady-state ultrasound response, is generated by shooting the pulse laser beam to the target structure, and is acquired by measuring the out-of-plane velocity using a laser vibrometer. The formation of the LMI response is observed through the thermo-mechanical finite element analysis. The feasibility of applying the LMI technique for damage detection is experimentally verified using a pipe specimen under high temperature environment.

  19. The effects of processing techniques on magnesium-based composite

    NASA Astrophysics Data System (ADS)

    Rodzi, Siti Nur Hazwani Mohamad; Zuhailawati, Hussain

    2016-12-01

    The aim of this study is to investigate the effect of processing techniques on the densification, hardness and compressive strength of Mg alloy and Mg-based composite for biomaterial application. The control sample (pure Mg) and Mg-based composite (Mg-Zn/HAp) were fabricated through mechanical alloying process using high energy planetary mill, whilst another Mg-Zn/HAp composite was fabricated through double step processing (the matrix Mg-Zn alloy was fabricated by planetary mill, subsequently HAp was dispersed by roll mill). As-milled powder was then consolidated by cold press into 10 mm diameter pellet under 400 MPa compaction pressure before being sintered at 300 °C for 1 hour under the flow of argon. The densification of the sintered pellets were then determined by Archimedes principle. Mechanical properties of the sintered pellets were characterized by microhardness and compression test. The results show that the density of the pellets was significantly increased by addition of HAp, but the most optimum density was observed when the sample was fabricated through double step processing (1.8046 g/cm3). Slight increment in hardness and ultimate compressive strength were observed for Mg-Zn/HAp composite that was fabricated through double step processing (58.09 HV, 132.19 MPa), as compared to Mg-Zn/HAp produced through single step processing (47.18 HV, 122.49 MPa).

  20. Hyperspectral-imaging-based techniques applied to wheat kernels characterization

    NASA Astrophysics Data System (ADS)

    Serranti, Silvia; Cesare, Daniela; Bonifazi, Giuseppe

    2012-05-01

    Single kernels of durum wheat have been analyzed by hyperspectral imaging (HSI). Such an approach is based on the utilization of an integrated hardware and software architecture able to digitally capture and handle spectra as an image sequence, as they results along a pre-defined alignment on a surface sample properly energized. The study was addressed to investigate the possibility to apply HSI techniques for classification of different types of wheat kernels: vitreous, yellow berry and fusarium-damaged. Reflectance spectra of selected wheat kernels of the three typologies have been acquired by a laboratory device equipped with an HSI system working in near infrared field (1000-1700 nm). The hypercubes were analyzed applying principal component analysis (PCA) to reduce the high dimensionality of data and for selecting some effective wavelengths. Partial least squares discriminant analysis (PLS-DA) was applied for classification of the three wheat typologies. The study demonstrated that good classification results were obtained not only considering the entire investigated wavelength range, but also selecting only four optimal wavelengths (1104, 1384, 1454 and 1650 nm) out of 121. The developed procedures based on HSI can be utilized for quality control purposes or for the definition of innovative sorting logics of wheat.