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Sample records for separator characterization studies

  1. Separation, Characterization and Initial Reaction Studies of Magnetite Particles from Hanford Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Donald R.; Grosz, Andrew E.; Ilton, Eugene S.; Krupka, Kenneth M.; Liu, Juan; Penn, Ryland L.; Pepin, Alex

    2010-04-24

    Magnetic and density separation methods have been applied to composite sediment sample from the Hanford formation from sediment recovered during drilling of an uncontaminated borehole located near the 200 West Area of the Hanford Site in southeastern Washington State. This paper describes the results of using those separation methods and from the characterization and initial reactivity measurements on a highly magnetic fraction isolated from that sediment. X-ray diffraction (XRD) analysis of the highly magnetic sediment fraction indicates that this material contains predominantly magnetite (Fe3O4). Particle morphology observed by scanning electron microscopy (SEM) and compositions determined energy dispersive spectroscopy (EDS) are consistent with this identification. Analyses by X-ray photoelectron spectroscopy (XPS) indicates that there is a thin coating on the particles that are likely a type of aluminosilicate. This highly magnetic fraction of material is not reactive with indigo carmine, an organic redox probe molecule that was shown to readily react with synthetic magnetite. Because of the limited amounts of material readily available, initial tests have been conducted that demonstrate the ability to complete U(VI) sorption on individual particles (nominally ~100 µm in size) of the isolated sediment and to remove and mount these individual particles for analysis of the concentration and chemical state of the sorbed U species using small area XPS.

  2. Separation, characterization and initial reaction studies of magnetite particles from Hanford sediments

    Science.gov (United States)

    Baer, D. R.; Grosz, A. E.; Ilton, E. S.; Krupka, K. M.; Liu, J.; Penn, R. L.; Pepin, A.

    Magnetic and density separation methods have been applied to composite sediment samples from the Hanford formation from sediment recovered during drilling of an uncontaminated borehole located near the 200 West Area of the Hanford Site in southeastern Washington State. This paper describes the results of using those separation methods and from the characterization and initial reactivity measurements on a highly magnetic fraction isolated from that sediment. X-ray diffraction (XRD) analysis of the highly magnetic sediment fraction indicates that this material contains predominantly magnetite (Fe 3O 4). Particle morphology observed by scanning electron microscopy (SEM) and compositions determined energy dispersive spectroscopy (EDS) are consistent with this identification. Analyses by X-ray photoelectron spectroscopy (XPS) indicates that there is a thin coating on the particles that are likely a type of aluminosilicate. This highly magnetic fraction of material is not reactive with indigo carmine, an organic redox probe molecule that was shown to readily react with synthetic magnetite. Because of the limited amounts of material readily available, initial tests have been conducted that demonstrate the ability to complete U(VI) sorption on individual particles (nominally ∼100 μm in size) of the isolated sediment and to remove and mount these individual particles for analysis of the concentration and chemical state of the sorbed U species using small area XPS.

  3. Separation, Characterization and Initial Reaction Studies of Magnetite Particles from Hanford Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Donald R.; Grosz, Andrew E.; Ilton, Eugene S.; Krupka, Kenneth M.; Liu, Juan; Penn, Ryland L.; Pepin, Alex

    2010-08-01

    Magnetic and density separation methods have been applied to composite sediment sample from the Hanford formation from sediment recovered during drilling of an uncontaminated borehole located near the 200 West Area of the Hanford Site in southeastern Washington State. This paper describes the results of using those separation methods and from the characterization and initial reactivity measurements on a highly magnetic fraction isolated from that sediment. X-ray diffraction (XRD) analysis of the highly magnetic sediment fraction indicates that this material contains predominantly magnetite (Fe3O4). Particle morphology observed by scanning electron microscopy (SEM) and compositions determined energy dispersive spectroscopy (EDS) are consistent with this identification. Analyses by X-ray photoelectron spectroscopy (XPS) indicates that there is a thin coating on the particles that are likely a type of aluminosilicate. This highly magnetic fraction of material is not reactive with indigo carmine, an organic redox probe molecule that was shown to readily react with synthetic magnetite. Because of the limited amounts of material readily available, initial tests have been conducted that demonstrate the ability to complete U(VI) sorption on individual particles (nominally ~100 µm in size) of the isolated sediment and to remove and mount these individual particles for analysis of the concentration and chemical state of the sorbed U species using small area XPS.

  4. Characterization of gelatin-agar based phase separated hydrogel, emulgel and bigel: a comparative study.

    Science.gov (United States)

    Wakhet, Senggam; Singh, Vinay K; Sahoo, Saikat; Sagiri, Sai Sateesh; Kulanthaivel, Senthilguru; Bhattacharya, Mrinal K; Kumar, Naresh; Banerjee, Indranil; Pal, Kunal

    2015-02-01

    The current study describes the in-depth characterization of agar-gelatin based co-hydrogels, emulgels and bigels to have an insight about the differences in the properties of the formulations. Hydrogels have been extensively studied as vehicle for controlled drug release, whereas, the concept of emulgels and bigels is relatively new. The formulations were characterized by scanning electron microscopy, FTIR spectroscopy, XRD and mechanical properties. The biocompatibility and the ability of the formulations to be used as drug delivery vehicle were also studied. The scanning electron micrographs suggested the presence of internal phases within the agar-gelatin composite matrices of co-hydrogel, emulgel and bigel. FTIR and XRD studies suggested higher crystallinity of emulgels and bigels. Electrical impedance and mechanical stability of the emulgel and the bigel was higher than the hydrogel. The prepared formulations were found to be biocompatible and suitable for drug delivery applications.

  5. Characterization and Separation Studies of a Fine Sedimentary Phosphate Ore Slime

    Directory of Open Access Journals (Sweden)

    Xin Liu

    2017-06-01

    Full Text Available Detailed characterization and recovery of apatite from a sedimentary phosphate ore slime of a gravity plant of Yichang, China, were investigated. The phosphate ore slime consisted mainly of apatite, quartz, dolomite, and clay. To start with, the ore slime was characterized in sufficient detail to reveal that it is extremely fine in distribution with a d50 of 65 μm. Other different characterizations, such as apatite grain size distribution, apatite liberation, particle density distribution, and theoretical grade recovery, were also analyzed by mineral liberation analyser (MLA. Based on the results, a new gravity-flotation process, which was comprised of spiral gravity and reverse flotation, was proposed to process the slime. In the new process, the apatite was firstly recovered by two-stage spiral gravity, avoiding direct flotation. The gravity concentrate was the feed for the reverse flotation. A phosphate concentrate of 30.51% P2O5 with a P2O5 recovery of 89.00% can be produced from the slime analyzing 24.25% P2O5. Compared to the conventional direct-reverse flotation process, it was found that the reagent cost of the new gravity-flotation process was lower a quarter than that of the direct-reverse flotation flowsheet.

  6. Electrokinetic characterization of whey protein separation

    DEFF Research Database (Denmark)

    Keiding, Kristian; Stougård, Anders; Christensen, Morten Lykkegaard

    Cross flow filtration of whey protein has been performed on 3 different membranes. The rejections have been determined by HPLC analysis of the feed and permeate. The pure membranes as well as the fouled membranes have been characterized by measurements of the streaming potential along the membrane...

  7. Separation and characterization of asphaltenic subfractions

    Energy Technology Data Exchange (ETDEWEB)

    Honse, Siller O.; Ferreira, Silas R.; Mansur, Claudia R. E.; Lucas, Elizabete F. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano; Gonzalez, Gaspar, E-mail: elucas@ima.ufrj.br [Centro de Pesquisas da PETROBRAS (CENPES), Rio de Janeiro, RJ (Brazil)

    2012-07-01

    The structure of the various asphaltenic subfractions found in crude oil was evaluated. For this purpose, C5 asphaltenes were extracted from an asphaltic residue using n-pentane as the flocculant solvent. The different subfractions were isolated from the C5 asphaltenes by the difference in solubility in different solvents. These were characterized by infrared spectroscopy, nuclear magnetic resonance, X-ray fluorescence, elementary analysis and mass spectrometry. The results confirmed that the subfractions extracted with higher alkanes had greater aromaticity and molar mass. However, small solubility variations between the subfractions were attributed mainly to the variation in the concentrations of cyclical hydrocarbon compounds and metals (author)

  8. Characterization and Analytical Separation of Fluorescent Carbon Nanodots

    Directory of Open Access Journals (Sweden)

    Qin Hu

    2017-01-01

    Full Text Available Carbon nanodots (C-dots are recently discovered fluorescent carbon nanoparticles with typical sizes of <10 nm. The C-dots have been reported to have excellent photophysical and chemical characteristics. In recent years, the advances in the development and improvement in C-dots synthesis, characterization, and applications are burgeoning. In this review, we introduce the most commonly used techniques for the characterization of C-dots. The characterization techniques for C-dots are briefly classified, described, and illustrated with applied examples. In addition, the analytical separation methods for C-dots (including electrophoresis, chromatography, density gradient centrifugation, differential centrifugation, solvent extraction, and dialysis are included and discussed according to their analytical characteristics. The review concludes with an outlook towards the future developments in the characterization and the analytical separation of C-dots. The comprehensive overview of the characterization and the analytical separation techniques will safeguard people to use each technique more wisely.

  9. Separation and characterization of phenolic compounds from ...

    African Journals Online (AJOL)

    Terminalia ivoriensis A. Chev. (Combretaceae) is an Ivorian medicinal plant. There is little ethnobotanical and almost no chemical information available for this species. The aim of this study was to isolate phenolic compounds from T. ivoriensis. In this way, its ethyl acetate extract (Ea) was fractionated by silica gel column ...

  10. Separation and characterization of phenolic compounds from ...

    African Journals Online (AJOL)

    Attioua

    2013-07-03

    Jul 3, 2013 ... Phytochemical and antifungal studies on Terminalia mollis and. Terminalia brachystemma. Fitoterapia 80:369-373. Martino V, Morales J, Martínez-Irujo JJ, Font M, Monge A, Coussio S. (2004). Two ellagitannins from the leaves of Terminalia tri[fllig]ora · with inhibitory activity on HIV-1 reverse transcriptase.

  11. Photovoltaic solar panels of crystalline silicon: Characterization and separation.

    Science.gov (United States)

    Dias, Pablo Ribeiro; Benevit, Mariana Gonçalves; Veit, Hugo Marcelo

    2016-03-01

    Photovoltaic panels have a limited lifespan and estimates show large amounts of solar modules will be discarded as electronic waste in a near future. In order to retrieve important raw materials, reduce production costs and environmental impacts, recycling such devices is important. Initially, this article investigates which silicon photovoltaic module's components are recyclable through their characterization using X-ray fluorescence, X-ray diffraction, energy dispersion spectroscopy and atomic absorption spectroscopy. Next, different separation methods are tested to favour further recycling processes. The glass was identified as soda-lime glass, the metallic filaments were identified as tin-lead coated copper, the panel cells were made of silicon and had silver filaments attached to it and the modules' frames were identified as aluminium, all of which are recyclable. Moreover, three different components segregation methods have been studied. Mechanical milling followed by sieving was able to separate silver from copper while chemical separation using sulphuric acid was able to detach the semiconductor material. A thermo gravimetric analysis was performed to evaluate the use of a pyrolysis step prior to the component's removal. The analysis showed all polymeric fractions present degrade at 500 °C. © The Author(s) 2016.

  12. Characterization of microglass wet laid nonwovens used as battery separators

    Energy Technology Data Exchange (ETDEWEB)

    Zientek, M.J.; Bender, R.J. [Schuller International, Inc., Toledo, OH (United States)

    1996-11-01

    Significant advancements have been made during the past few years in the battery industry with the development of Valve Regulated Lead-Acid (VRLA) cells for a variety of applications. Today, most sealed or gas recombining, lead-acid batteries utilize absorptive microglass separators in their design. The 100% microglass battery separator mat used in rechargeable lead-acid batteries has been identified as being a critical component necessary for the operation of these cells. With the growing importance of the microglass separator in modern battery technology, an understanding of the various properties of the separator is essential to better understand the impact separators have on battery performance. A method for characterizing microglass separators is described by surface area, mechanical, chemical, and microscopy techniques.

  13. Urban and Rural MSW Stream Characterization for Separate Collection Improvement

    Directory of Open Access Journals (Sweden)

    Simona Ciuta

    2015-01-01

    Full Text Available In the new legislation framework enacted by new member countries of the European Union (EU, the characterization of municipal solid waste (MSW represents an important instrument for local governments and sanitation operators in setting and achieving targets for waste recycling and recovery. This paper presents the results of a study conducted in accordance with the Romanian methodology for domestic wastes characterization ROMECOM, aiming to provide a proper basis for developing clear and realistic forecasts in current municipal waste management, based on MSW composition and generation rate. The analyzed MSW came both from areas where the waste is collected in mixed and separate ways, in urban and rural areas. The MSW composition by fraction is detailed for dense urban areas, urban areas, rural and touristic areas from Romania. Based on these results, the MSW composition was determined for the eight development regions in Romania, and a generation rate of 0.9·kgMSW inhabitant−1·day−1 for the urban region and 0.4·kgMSW inh−1·day−1 for the rural region was established. The calorific values of urban and rural areas were determined as 6801 kJ·kg−1 and 5613 kJ·kg−1, respectively. In the perspective of sustainable development in this technical area, based on the obtained results and on the prognosis made for the following years, two proposals for urban and rural areas were developed for MSW treating options improvement. The two systems are characterized by selective collection (different efficiencies for urban and rural areas with subsequent recovery of the separated materials and energy recovery of the residual waste in a large-scale waste to energy (WTE plant.

  14. Material Characterization for the Analysis of Skin/Stiffener Separation

    Science.gov (United States)

    Davila, Carlos G.; Leone, Frank A.; Song, Kyongchan; Ratcliffe, James G.; Rose, Cheryl A.

    2017-01-01

    Test results show that separation failure in co-cured skin/stiffener interfaces is characterized by dense networks of interacting cracks and crack path migrations that are not present in standard characterization tests for delamination. These crack networks result in measurable large-scale and sub-ply-scale R curve toughening mechanisms, such as fiber bridging, crack migration, and crack delving. Consequently, a number of unknown issues exist regarding the level of analysis detail that is required for sufficient predictive fidelity. The objective of the present paper is to examine some of the difficulties associated with modeling separation failure in stiffened composite structures. A procedure to characterize the interfacial material properties is proposed and the use of simplified models based on empirical interface properties is evaluated.

  15. A plateau-valley separation method for multifunctional surfaces characterization

    DEFF Research Database (Denmark)

    Godi, Alessandro; Kühle, A.; De Chiffre, Leonardo

    2012-01-01

    method based on the separation between the plateau and valley regions has been developed. After properly determining a threshold between plateaus and valleys, the two regions are divided in two distinct profiles, which can be studied separately according to the specific function....

  16. Study Of Phase Separation In Glass

    Science.gov (United States)

    Neilson, George F.; Weinberg, Michael C.; Smith, Gary L.

    1989-01-01

    Report describes an experimental study of effect of hydroxide content on phase separation in soda/silica glasses. Ordinary and gel glasses melted at 1,565 degree C, and melts stirred periodically. "Wet" glasses produced by passing bubbles of N2 saturated with water through melts; "dry" glasses prepared in similar manner, except N2 dried before passage through melts. Analyses of compositions of glasses performed by atomic-absorption and index-of-refraction measurements. Authors conclude hydroxide speeds up phase separation, regardless of method (gel or ordinary) by which glass prepared. Eventually helps material scientists to find ways to control morphology of phase separation.

  17. [Separation and purification and structural characterization of baicalein].

    Science.gov (United States)

    Li, Yun-xia; Suo, Quan-ling; He, Wen-zhi; Li, Chun-ping; Huang, Yan-chun

    2008-08-01

    The root of scutellaria baicalensis georgi that contains a variety of flavonoids is a very old and well-known drug in traditional Chinese medicine, which is widely used for treatment of bronchitis, tumors and inflammatory diseases. The baicalein is the main active component from traditional Chinese medicine-scutellaria baicalensis georgi. It is a very significance research work that the baicalein was separated and purified, and its composition and molecular structure are analyzed and determined for the pharmacology study of Chinese medicine-scutellaria baicalensis georgi. The main works in this paper are as follows. Powdered roots (100 g) were extracted with methanol by three times, each time for 48 hours. The crude extracts were purified by polyamide column chromatography and CH3Cl-C2H5OH gradient desorption. A short yellow prismatic crystal was acquired by recrystallizing technique and its composition and molecular structure were characterized by color reactions and spectral analysis methods as FTIR, UV-Vis, MS and 1H NMR, 13C-NMR. The FTIR spectrum appears the absorption bands for hydroxyls, pyrone carbonyl, aromatic C=C bond and singly substituted phenyl. The characteristic absorption peaks and the vibration modes in FTIR spectrum were identified as corresponding groups. The UV-Vis spectrum in methanol solution and the mix solution of methanol with 5 diagnostic reagents, NaOMe, NaOAc, NaOAc/H3BO3, AlCl3, AlCl3/HCl, respectively indicate that the yellow prismatic crystal is flavone with 5-hydroxyl, 4-carbonyl and 5,6,7- or 5,7,8-trihydroxyls on ring A. The structure of the crystal was characterized by three different MS. The results of FAB-, ESI- and EI-MS show that it is not a flavone glocuside but the flavone with three phenyl hydroxyls on ring A, and no OH group and other substituted groups on ring B. The molecular ion and fragment ions are identified by MS, which include such as m/z 270 M+, m/z 242 [M-CO]+, m/z 168 A, m/z 140 [A1-CO]+, m/z 105 B, m/z 102 B

  18. Density Gradient Separation of Detonation Soot for Nanocarbon Characterization

    Science.gov (United States)

    Ringstrand, Bryan; Jungjohann, Katie; Seifert, Sonke; Firestone, Millicent; Podlesak, David

    2017-06-01

    Detonation of high explosives (HE) can expand our understanding of chemical bonding at extreme conditions as well as the opportunity to prepare carbon nanomaterials. In order to understand detonation mechanisms, nanocarbon characterization contained within the soot is paramount. Thus, benign purification methods for detonation soot are important for its characterization. Progress towards a non-traditional approach to detonation soot processing is presented. Purification of soot using heavy liquid media such as sodium polytungstate to separate soot components based on their density was tested based on the premise that different nanocarbons possess different densities [ ρ = 1.79 g/cm3 (graphene) and ρ = 3.05 g/cm3 (nanodiamond)]. Analysis using XRD, SAXS, WAXS, Raman, XPS, TEM, and NMR provided information about particle morphology and carbon hybridization. Detonation synthesis offers an avenue for the discovery of new carbon frameworks. In addition, understanding reactions at extreme conditions provides for more accurate predictions of HE performance, explosion intent, and simulation refinement. These results are of interest to both the nanoscience and shock physics communities. We acknowledge the support of the U.S. Department of Energy LANL/LDRD Program (LANL #20150050DR). LA-UR-17-21502.

  19. Characterization and Modeling of Materials for Kr-Xe Separations

    Energy Technology Data Exchange (ETDEWEB)

    Forster, Paul [Univ. of Nevada, Las Vegas, NV (United States); Naduvalath, Balakrishnan [Univ. of Nevada, Las Vegas, NV (United States); Czerwinski, Ken [Univ. of Nevada, Las Vegas, NV (United States)

    2015-11-16

    We sought to identify practical adsorbents for the separation of Kr from Xe through pressure swing adsorption. We spent appreciable efforts on two categories of materials: metal-organic frameworks (MOFs) and zeolites. MOFs represent a new and exciting sorbent with numerous new framework topologies and surface chemistries. Zeolites are widely used and available commercial adsorbents. We have employed a combination of gas sorption analysis to analyze gas – surface interactions, computational modelling to both aid in interpreting experimental results and to predict practical adsorbents, and in-situ crystallographic studies to confirm specific experimental results.

  20. Experimental studies on transitional separated boundary layers

    OpenAIRE

    Serna Serrano, José

    2013-01-01

    Separated transitional boundary layers appear on key aeronautical processes such as the flow around wings or turbomachinery blades. The aim of this thesis is the study of these flows in representative scenarios of technological applications, gaining knowledge about phenomenology and physical processes that occur there and, developing a simple model for scaling them. To achieve this goal, experimental measurements have been carried out in a low speed facility, ensuring the flow homogeneity and...

  1. Separation and characterization of nanoparticles in complex food and environmental samples by field-flow fractionation

    DEFF Research Database (Denmark)

    Kammer, Frank von der; Legros, Samuel; Hofmann, Thilo

    2011-01-01

    has been applied for separation of various types of NP (e.g., organic macromolecules, and carbonaceous or inorganic NPs) in different types of media (e.g., natural waters, soil extracts or food samples).FFF can be coupled to different types of detectors that offer additional information...... sample preparation, field-flow fractionation (FFF) is one of the most promising techniques to achieve relevant characterization.The objective of this review is to present the current status of FFF as an analytical separation technique for the study of NPs in complex food and environmental samples. FFF...... constituents in the samples require contradictory separation conditions. The potential of FFF analysis should always be evaluated bearing in mind the impact of the necessary sample preparation, the information that can be retrieved from the chosen detection systems and the influence of the chosen separation...

  2. Preparation and Characterization of Membranes Formed by Nonsolvent Induced Phase Separation: A Review

    KAUST Repository

    Guillen, Gregory R.

    2011-04-06

    The methods and mechanisms of nonsolvent induced phase separation have been studied for more than fifty years. Today, phase inversion membranes are widely used in numerous chemical industries, biotechnology, and environmental separation processes. The body of knowledge has grown exponentially in the past fifty years, which suggests the need for a critical review of the literature. Here we present a review of nonsolvent induced phase separation membrane preparation and characterization for many commonly used membrane polymers. The key factors in membrane preparation discussed include the solvent type, polymer type and concentration, nonsolvent system type and composition, additives to the polymer solution, and film casting conditions. A brief introduction to membrane characterization is also given, which includes membrane porosity and pore size distribution characterization, membrane physical and chemical properties characterization, and thermodynamic and kinetic evaluation of the phase inversion process. One aim of this review is to lay out the basics for selecting polymer solvent nonsolvent systems with appropriate film casting conditions to produce membranes with the desired performance, morphology, and stability, and to choose the proper way to characterize these properties of nonsolvent induced phase inversion membranes. © 2011 American Chemical Society.

  3. Modelling centrifugal partition chromatography separation behavior to characterize influencing hydrodynamic effects on separation efficiency.

    Science.gov (United States)

    Schwienheer, C; Krause, J; Schembecker, G; Merz, J

    2017-04-07

    In addition to the selection or adjustment of phase systems to gain a suitable partition coefficient for the target molecule, the separation efficiency in centrifugal partition chromatography (CPC) is strongly influenced by the hydrodynamic interactions of the mobile and the stationary phase in the chambers. Thus, the hydrodynamic interactions must be investigated and understood in order to enhance a CPC separation run. Different hydrodynamic effects like mass transfer, back mixing and the non-ideal behavior of stationary phase, which cannot be determined directly, are known, but quantifying these effects and their influence on separation performance is barely achieved. In order to understand their influence, a physically detailed mathematical model of a CPC chamber was developed. The model includes a parameter representing the hydrodynamic effects mentioned above and is able to determine the parameters significance by fitting them to separation experiment data. The acquired knowledge is used to correlate the effects of the hydrodynamic influences on the separation performance and can be used to forecast hydrodynamic and separation behavior in a CPC device. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Experimental Study of Separate Type Thermosyphon

    Science.gov (United States)

    Hirashima, Masao; Kawahata, Kenya; Negishi, Kanji

    The passages of vapor flow and the returning liquid flow are perfectly partitioned in a separate type thermosyphon. Therefore the flooding limit can be eliminated and practicability based on its construction is highly evaluated. The carry-over of the liquid into the condensing section accompanied with the rising vapor flow should be avoided in the separate type thermosyphon, since it causes to decrease the heat transfer coefficient on the heat transfer surface in the condenser. In the present work, the effect of liquid level, the heat input into the evaporating section, the charging rate of the liquid, and the dimension of the adiabatic section supposed on the generation of carry-over were studied experimentally. The frequency of the bumping and the velocity of the vapor in the adiabatic section were examined as the function of the termination of the carry-over. The experimental correlation representing the relation among the elapsed time, the liquid temperature and the charging rate of the liquid were also derived.

  5. Biochemical characterization of density-separated human erythrocytes.

    Science.gov (United States)

    Cohen, N S; Ekholm, J E; Luthra, M G; Hanahan, D J

    1976-01-21

    A simple, reproducible method for the separation of human erythrocytes, described recently (Murphy, J. R. (1973) J. Lab. Clin. Med. 82, 334-341) has been utilized for the purpose of obtaining a wide range of biochemical data on these cells. Using phthalate ester density centrifugation of the fractions obtained by Murphy's method, we established that the cells were separated exclusively on the basis of their densities. Data on a wide range of biochemical and hematological parameters, when compared with previously reported density separation procedures showed that this simple technique can be used to fractionate the cells according to their densities (age) in their own plasma. Cells of increasing density consistently and reproducibly exhibited an increase in hemoglobin concentration, a moderate elevation in Na+ and a decrease in the following: K+, acetylcholinesterase, sialic acid, membrane protein, 2,3-diphosphoglycerate, ATP, cholesterol, phospholipid, mean corpuscular volume and critical hemolytic volume, However, no change in mean corpuscular hemoglobin was evident. The observed differences were not artifacts of the centrifugation process. This was determined in recentrifuged top fractions from which new top and bottom cells were obtained. The latter cells resembled the top fraction from which they were obtained, rather than the original bottom fraction. Whereas the parameters mentioned above exhibited consistency and reproducibility, such was not the case with the ATPase values. Depending on the cell density group examined and/or buffer as well as other conditions, significant variability in the activity levels of the ouabain sensitive, as well as the Ca2+ -stimulated ATPase, was observed. Use of these enzyme activities as indicators of cell age must be viewed with caution.

  6. Synthesis and characterization of microporous inorganic membranes for propylene/propane separation

    Science.gov (United States)

    Ma, Xiaoli

    Membrane-based gas separation is promising for efficient propylene/propane (C3H6/C3H8) separation with low energy consumption and minimum environment impact. Two microporous inorganic membrane candidates, MFI-type zeolite membrane and carbon molecular sieve membrane (CMS) have demonstrated excellent thermal and chemical stability. Application of these membranes into C3H6/C3H 8 separation has not been well investigated. This dissertation presents fundamental studies on membrane synthesis, characterization and C3H 6/C3H8 separation properties of MFI zeolite membrane and CMS membrane. MFI zeolite membranes were synthesized on α-alumina supports by secondary growth method. Novel positron annihilation spectroscopy (PAS) techniques were used to non-destructively characterize the pore structure of these membranes. PAS reveals a bimodal pore structure consisting of intracrystalline zeolitic micropores of ~0.6 nm in diameter and irregular intercrystalline micropores of 1.4 to 1.8 nm in size for the membranes. The template-free synthesized membrane exhibited a high permeance but a low selectivity in C3H 6/C3H8 mixture separation. CMS membranes were synthesized by coating/pyrolysis method on mesoporous gamma-alumina support. Such supports allow coating of thin, high-quality polymer films and subsequent CMS membranes with no infiltration into support pores. The CMS membranes show strong molecular sieving effect, offering a high C3H 6/C3H8 mixture selectivity of ~30. Reduction in membrane thickness from 500 nm to 300 nm causes an increase in C3H8 permeance and He/N2 selectivity, but a decrease in the permeance of He, N 2 and C3H6 and C3H6/C 3H8 selectivity. This can be explained by the thickness dependent chain mobility of the polymer film resulting in final carbon membrane of reduced pore size with different effects on transport of gas of different sizes, including possible closure of C3H6-accessible micropores. CMS membranes demonstrate excellent C3H6/C 3H8 separation

  7. Isolation, separation, and characterization of epithelial and connective cells from rat palate

    Energy Technology Data Exchange (ETDEWEB)

    Terranova, Victor Paul [Univ. of Rochester, NY (United States)

    1979-01-01

    Epithelial and connective tissue cells were isolated from rat palate by sequential collagenase, hyaluronidase and trypsin digestion of the extracellular matrix. Differences between the two populations were noted with respect to total cell protein, total cell water, proline uptake and incorporation, percent collagen synthesized, effects of parathyroid hormone, metabolism of D-valine and cell density. Basal epithelial cells were subsequently separated from the heterogeneous epithelial cell population on shallow linear density gradients by velocity centrifugation. The type of collagen synthesized by the basal epithelial cells was compared to the type of collagen synthesized by the connective tissue cells by means of labeled amino acid incorporation ratios. Cells isolated from the epithelial and connective tissue were compared. From these studies it can be concluded that epithelial and connective tissue cells can be isolated from rat palate as viable and distinct populations with respect to the biochemical parameters examined. Furthermore, subpopulations can be separated and biochemically characterized.

  8. A Regenerable VOC Control System (RVCS) for Characterizing Properties of Sorbents Used in Separation Technologies

    Science.gov (United States)

    Nolek, Sara D.; Monje, Oscar A.

    2010-01-01

    This slide presentation reviews the design, method of operation, and testing of a regenerable Volatile Organic Compound (VOC) control system that characterizes properties of sorbents used in separation technologies.

  9. [Separation and characterization of mitochondrial COI pseudogenes in Scylla paramamosain].

    Science.gov (United States)

    Zhang, Feng-Ying; Ma, Ling-Bo; Qiao, Zhen-Guo; Ma, Chun-Yan

    2006-01-01

    Mitochondrial DNA marker has been applied in genetic structure and phylogenetic analysis, but the differences between nuclear mitochondrial pseudogenes (Numts) and mitochondrial DNA complicate phylogenetic analysis. Using the universal and special primers, 34 pseudogene sequences (Numts) and 5 real mtDNA COI sequences were amplified respectively from 34 individuals of Scylla paramamosain from the coast of southeast China. Twenty-nine haplotypes were identified and two groups (Group I and Group II) were determined according to the homology of the 34 pseudogene sequences. Two insertions and an 8-bp deletion were found in some sequences of Group I, but no indel (insertion and deletion) was found in Group II. Compared to mtDNA COI sequences, the two groups had their conservative sites respectively. At least two independent nuclear transfer events are required to explain the codon position biases revealed through the pairwise comparisons of the 34 Numts, one for Group I and one for Group II. The results showed the necessity of great care in interpreting PCR-generated mtDNA sequences using universal primers when used in population or evolutionary studies in genus Scylla.

  10. Separation and characterization of vanadium and nickel organometallic compounds in heavy crudes

    Energy Technology Data Exchange (ETDEWEB)

    Nali, M.; Corana, F.; Scilingo, A.; Scotti, R. (Eniricerche S.p.A., Milan (Italy))

    1994-01-01

    A new separation scheme has been developed to concentrate nickel and vanadium complexes in selected fractions before attempting a molecular characterization of these organometallic species in heavy crude oils. It involves a combination of solubility- (n-heptane deasphalting and pyridine/water extraction of asphaltenes) and polarity- (SO[sub 3]-modified silica gel column) based steps. The proposed method has been applied to Belayim crude oil. The nature of pyridine/water extract from asphaltenes has been investigated using both preparative gel permeation chromatography (GPC) and reverse phase liquid chromatography (RP-HPLC) combined (off-line) to graphite furnace atomic absorption (GFAA). The fractions obtained after the separation of the extract on a SO[sub 3]-modified silica gel column have been submitted to a series of analytical techniques. All the analytical evidence arising from the present study, indicates that vanadium, present in pyridine/water extract obtained from asphaltenes, is mostly bound in porphyrin structures, although the coordination sphere around vanadyl species, present in the most polar fraction obtained from the extract separation by column chromatography, shows different EPR parameter. On the other hand, nickel complexes are smaller and more polar than common Ni-porphyrins, which are concentrated in deasphalted oil. 16 refs., 9 figs., 2 tabs.

  11. Characterization of Printed Circuit Boards for Metal and Energy Recovery after Milling and Mechanical Separation

    Directory of Open Access Journals (Sweden)

    Waldir A. Bizzo

    2014-06-01

    Full Text Available The proper disposal of electrical and electronic waste is currently a concern of researchers and environmental managers not only because of the large volume of such waste generated, but also because of the heavy metals and toxic substances it contains. This study analyzed printed circuit boards (PCBs from discarded computers to determine their metal content and characterized them as solid waste and fuel. The analysis showed that PCBs consist of approximately 26% metal, made up mainly of copper, lead, aluminum, iron and tin, as well as other heavy metals such as cadmium and nickel. Comparison with the results of other studies indicated that the concentration of precious metals (gold and silver has declined over time. Analysis of the leachate revealed high concentrations of cadmium and lead, giving the residue the characteristics of hazardous waste. After milling the PCBs, we found that larger amounts of metal were concentrated in smaller fractions, while the lightest fraction, obtained by density separation, had a gross calorific value of approximately 11 MJ/kg, although with a high ash content. Milling followed by density separation proved potentially useful for recovery of metals and energy-rich fractions.

  12. Characterization of new types of stationary phases for fast and ultra-fast liquid chromatography by signal processing based on AutoCovariance Function: a case study of application to Passiflora incarnata L. extract separations.

    Science.gov (United States)

    Pietrogrande, Maria Chiara; Dondi, Francesco; Ciogli, Alessia; Gasparrini, Francesco; Piccin, Antonella; Serafini, Mauro

    2010-06-25

    In this study, a comparative investigation was performed of HPLC Ascentis (2.7 microm particles) columns based on fused-core particle technology and Acquity (1.7 microm particles) columns requiring UPLC instruments, in comparison with Chromolith RP-18e columns. The study was carried out on mother and vegetal tinctures of Passiflora incarnata L. on one single or two coupled columns. The fundamental attributions of the chromatographic profiles are evaluated using a chemometric procedure, based on the AutoCovariance Function (ACVF). Different chromatographic systems are compared in terms of their separation parameters, i.e., number of total chemical components (m(tot)), separation efficiency (sigma), peak capacity (n(c)), overlap degree of peaks and peak purity. The obtained results show the improvements achieved by HPLC columns with narrow size particles in terms of total analysis time and chromatographic efficiency: comparable performance are achieved by Ascentis (2.7 microm particle) column and Acquity (1.7 microm particle) column requiring UPLC instruments. The ACVF plot is proposed as a simplified tool describing the chromatographic fingerprint to be used for evaluating and comparing chemical composition of plant extracts by using the parameters D% - relative abundance of the deterministic component - and c(EACF) - similarity index computed on ACVF. Copyright 2010 Elsevier B.V. All rights reserved.

  13. Separation of Salmonella typhimurium DT2 and DT135: Molecular characterization of isolates of avian origin

    DEFF Research Database (Denmark)

    Baggesen, Dorte Lau; Skov, M. N.; Brown, D. J.

    1997-01-01

    characterization of 23 Danish isolates, 10 German isolates and the two type strains have subsequently been performed. With only minor exceptions, strains examined could be separated by combination of 0:5 agglutination, ribotyping, and PFGE typing into two major groups in conformity with their phage types...

  14. A Novel Strategy for Characterization of Glycosylated Proteins Separated by Gel Electrophoresis

    DEFF Research Database (Denmark)

    Larsen, Martin; Skottrup, Peter; Enghild, Jan Johannes

    at a sensitivity level comparable with state-of-the-art proteomics. Whereas techniques exist for characterization of high abundant glycoproteins, no single method is presently capable of providing information on both site occupancy and glycan structure on a single band or spot excised from an electrophoretic gel....... We present a new technique, which allows full characterization of low amounts of glycoproteins separated by gel electrophoresis. The method takes advantage of sequential specific and non-specific enzymatic treatment, followed by selective purification and characterization of the glycopeptides using...

  15. A Novel Strategy for Characterization of Glycosylated Proteins Separated by Gel Electrophoresis

    DEFF Research Database (Denmark)

    Larsen, Martin; Skottrup, Peter; Enghild, Jan J.

    2005-01-01

    at a sensitivity level comparable with state-of-the-art proteomics. Whereas techniques exist for characterization of high abundant glycoproteins, no single method is presently capable of providing information on both site occupancy and glycan structure on a single band or spot excised from an electrophoretic gel....... We present a new technique, which allows full characterization of low amounts of glycoproteins separated by gel electrophoresis. The method takes advantage of sequential specific and non-specific enzymatic treatment, followed by selective purification and characterization of the glycopeptides using...

  16. Preparation and characterization of a Lithium-ion battery separator from cellulose nanofibers

    Directory of Open Access Journals (Sweden)

    Hongfeng Zhang

    2015-10-01

    Full Text Available Optimizing the desired properties for stretch monolayer separators used in Lithium-ion batteries has been a challenge. In the present study a cellulose nanofiber/PET nonwoven composite separator is successfully fabricated, using a wet-laid nonwoven (papermaking process, which can attain optimal properties in wettability, mechanical strength, thermal resistance, and electrochemical performance simultaneously. The PET nonwoven material, which is fabricated from ultrafine PET fibers by a wet-laid process, is a mechanical support layer. The porous structure of the composite separator was created by cellulose nanofibers coating the PET in a papermaking process. Cellulose nanofibers (CNFs, which are an eco-friendly sustainable resource, have been drawing considerable attention due to their astounding properties, such as: incredible specific surface area, thermal and chemical stability, high mechanical strength and hydrophilicity. The results show that the CNF separator exhibits higher porosity (70% than a PP (polypropylene separator (40%. The CNF separator can also be wetted by electrolyte in a few seconds while a PP separator cannot be entirely wetted after 1 min. The CNF separator has an electrolyte uptake of 250%, while a PP separator has only 65%. Another notable finding is that the CNF separator has almost no shrinkage when exposed to 180 °C for 1 h, whereas a PP separator shrinks by more than 50%. Differential Scanning Calorimetry (DSC shows that the CNF separator has a higher melting point than a PP separator. These findings all indicate that the CNF 29 separator will be more favorable than stretch film for use in Lithium-ion batteries.

  17. Battery Separator Characterization and Evaluation Procedures for NASA's Advanced Lithium-Ion Batteries

    Science.gov (United States)

    Baldwin, Richard S.; Bennet, William R.; Wong, Eunice K.; Lewton, MaryBeth R.; Harris, Megan K.

    2010-01-01

    To address the future performance and safety requirements for the electrical energy storage technologies that will enhance and enable future NASA manned aerospace missions, advanced rechargeable, lithium-ion battery technology development is being pursued within the scope of the NASA Exploration Technology Development Program s (ETDP's) Energy Storage Project. A critical cell-level component of a lithium-ion battery which significantly impacts both overall electrochemical performance and safety is the porous separator that is sandwiched between the two active cell electrodes. To support the selection of the optimal cell separator material(s) for the advanced battery technology and chemistries under development, laboratory characterization and screening procedures were established to assess and compare separator material-level attributes and associated separator performance characteristics.

  18. Separation and characterization of maternal cardiac and vascular sounds in the third trimester of pregnancy.

    Science.gov (United States)

    Riknagel, Diana; Zimmermann, Henrik; Farlie, Richard; Hammershøi, Dorte; Schmidt, Samuel E; Hedegaard, Morten; Humaidan, Peter; Struijk, Johannes J

    2017-06-01

    To characterize the vascular sounds of the uteroplacental blood flow obtained by microphones. The present retrospective study took place in an anechoic chamber facility at Aalborg University, Aalborg, Denmark, in 2012, and included pregnant participants aged 18-40 years with a singleton pregnancy at 32-36 weeks and a parity of 0-2. Abdominal Doppler ultrasonography was performed bilaterally on the uterine arteries. Subsequently, in the same positions, sound recordings were performed with microphones. The derived raw sound signal was separated into two frequency ranges, and characterized accordingly. The mean pregnancy length among 25 participants was 33.6 ± 2.0 weeks. The pulsatility index of the uterine artery was 0.67 ± 0.24. All 50 recordings displayed the first and second maternal heart sounds (frequency 25-100 Hz), and in 17 of 50 recordings, maternal vascular murmurs (frequency 200-800 Hz) were present. The average pulse wave velocity between the maternal aortic valve and the uterine artery was estimated to be 6.6 ± 1.5 m/s. Maternal vascular murmurs in the frequency range of 200-800 Hz were identified as a possible marker of abnormal uteroplacental blood flow, and provide a means to measure the arterial pulse wave velocity. © 2017 International Federation of Gynecology and Obstetrics.

  19. Studies on separation and properties of lumbrokinase in Pheretima praepinguis

    Directory of Open Access Journals (Sweden)

    Tang Mei

    2016-04-01

    Full Text Available The purpose of this study was to separate lumbrokinase in Pheretima praepinguis and examine its enzymatic properties. With P. praepinguis as material, lumbrokinase was separated with the salting out method. Lumbrokinase activity was measured with casein medium plate method. Effect of pH and temperature on lumbrokinase activity was studied. Results of lumbrokinase separated from P. praepinguis was relatively high. Lumbrokinase activity in neutral or slightly alkaline environment was higher. Lumbrokinase had tolerance ability to high temperature, with highly enzymatic activity under 60°C and wide range of temperature adaptation.

  20. Advanced Characterization of Molecular Interactions in TALSPEAK-like Separations Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nash, Kenneth [Washington State Univ., Pullman, WA (United States); Guelis, Artem [Argonne National Lab. (ANL), Argonne, IL (United States); Lumetta, Gregg J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sinkov, Sergey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-10-21

    Combining unit operations in advanced aqueous reprocessing schemes brings obvious process compactness advantages, but at the same time greater complexity in process design and operation. Unraveling these interactions requires increasingly sophisticated analytical tools and unique approaches for adequate analysis and characterization that probe molecular scale interactions. Conventional slope analysis methods of solvent extraction are too indirect to provide much insight into such interactions. This project proposed the development and verification of several analytical tools based on studies of TALSPEAK-like aqueous processes. As such, the chemistry of trivalent fission product lanthanides, americium, curium, plutonium, neptunium and uranium figure prominently in these studies. As the project was executed, the primary focus fell upon the chemistry or trivalent lanthanides and actinides. The intent of the investigation was to compare and contrast the results from these various complementary techniques/studies to provide a stronger basis for predicting the performance of extractant/diluent mixtures as media for metal ion separations. As many/most of these techniques require the presence of metal ions at elevated concentrations, it was expected that these studies would take this investigation into the realm of patterns of supramolecular organization of metal complexes and extractants in concentrated aqueous/organic media. We expected to advance knowledge of the processes that enable and limit solvent extraction reactions as a result of the application of fundamental chemical principles to explaining interactions in complex media.

  1. Design Study on a New Separator for PEEM3

    CERN Document Server

    Wan, Weishi; Padmore, Howard A

    2005-01-01

    A new aberration-corrected Photoemission Electron Microscope, called PEEM3, is under development at the Advanced Light Source. The resolution and transmission improvement is realized by correcting the lowest order spherical and chromatic aberrations using an electron mirror. A separator is required to separate the incoming uncorrected electron beam to the mirror from the corrected outgoing electron beam to the projector column. In this paper, we present a design study of a new separator for PEEM3. The layout, the Gaussian optics, the analysis of aberrations and the tolerance on power supply stability and alignment errors are reported.

  2. Geometric characterization of separability and entanglement in pure Gaussian states by single-mode unitary operations

    Science.gov (United States)

    Adesso, Gerardo; Giampaolo, Salvatore M.; Illuminati, Fabrizio

    2007-10-01

    We present a geometric approach to the characterization of separability and entanglement in pure Gaussian states of an arbitrary number of modes. The analysis is performed adapting to continuous variables a formalism based on single subsystem unitary transformations that has been recently introduced to characterize separability and entanglement in pure states of qubits and qutrits [S. M. Giampaolo and F. Illuminati, Phys. Rev. A 76, 042301 (2007)]. In analogy with the finite-dimensional case, we demonstrate that the 1×M bipartite entanglement of a multimode pure Gaussian state can be quantified by the minimum squared Euclidean distance between the state itself and the set of states obtained by transforming it via suitable local symplectic (unitary) operations. This minimum distance, corresponding to a , uniquely determined, extremal local operation, defines an entanglement monotone equivalent to the entropy of entanglement, and amenable to direct experimental measurement with linear optical schemes.

  3. Dielectric barrier discharge ionization in characterization of organic compounds separated on thin-layer chromatography plates.

    Science.gov (United States)

    Cegłowski, Michał; Smoluch, Marek; Babij, Michał; Gotszalk, Teodor; Silberring, Jerzy; Schroeder, Grzegorz

    2014-01-01

    A new method for on-spot detection and characterization of organic compounds resolved on thin layer chromatography (TLC) plates has been proposed. This method combines TLC with dielectric barrier discharge ionization (DBDI), which produces stable low-temperature plasma. At first, the compounds were separated on TLC plates and then their mass spectra were directly obtained with no additional sample preparation. To obtain good quality spectra the center of a particular TLC spot was heated from the bottom to increase volatility of the compound. MS/MS analyses were also performed to additionally characterize all analytes. The detection limit of proposed method was estimated to be 100 ng/spot of compound.

  4. An improved matrix separation method for characterization of ultrapure germanium (8N).

    Science.gov (United States)

    Reddy, M A; Shekhar, R; Jai Kumar, Sunil

    2016-10-01

    An improved matrix separation method has been described to characterize ultrapure germanium of 8N (99.999999%) purity. In this method, temperature of the reaction vessel in which in-situ generated chlorine gas reacts with germanium solid material directly is optimized to quantitatively remove Ge matrix from all its impurities. Optimized reaction temperature has been found to be 230±5°C. Recovery studies on more than 60 elements have been carried out at the optimized temperature. Recoveries of all the analytes except As, Se, Sn, Hg, Tl are found to be quantitative. The method has been examined for various amounts of Ge material and found to be suitable even for 10g of Ge sample and provides low parts per billion and trillion levels of process blanks. Determination of concentrations of impurities has been done by inductively coupled plasma quadrupole mass spectrometer (ICP-QMS) and high resolution continuum source graphite furnace atomic absorption spectrometer (HR-CS-GFAAS). In the absence of certified reference materials for ultrapure germanium, accuracy of the proposed method is established by spike recovery tests. Precision of this method is found to vary from 7% to 50% for concentrations between 4 and 0.004ngg(-1). Limits of detection (LOD) for the target analytes are found to be between 6 and 0.011ngmL(-1) or 1.8-0.003ngg(-1) for the proposed procedure. The method has been successfully applied for that characterization of ultrapure germanium material of 8N purity. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Hemicelluloses prior to aspen chemithermomechanical pulping: pre-extraction, separation, and characterization.

    Science.gov (United States)

    Liu, Wei; Hou, Qingxi; Mao, Changbin; Yuan, Zhirun; Li, Kecheng

    2012-05-16

    A portion of hemicelluloses and acetic acid can be pre-extracted with dilute sulfuric acid prior to the aspen chemithermomechanical pulp process. The streams collected from the second press-impregnation stage after acid pre-extraction contain a significant amount of acid pre-extracted hemicelluloses. Most of the total sugars obtained from the pressate were xylan, in which xylan was further hydrolyzed to sugar monomers under the acid pre-extraction condition. To fully understand the characteristics of hemicelluloses yielded prior to pulping, the pre-extracted hemicelluloses were separated and characterized by FT-IR, (1)H NMR, and thermogravimetric analysis in this study. Most of the FT-IR bonds from the hemicelluloses agreed well with the other two spectra of birch xylan and CA0050 xylan, except a new absorption at 1734 cm(-1) contributed to acetyl groups. The hemicelluloses obtained from acid pre-extraction began to decompose significantly at about 225 °C, slightly lower in comparison with organosolv and alkaline hemicelluloses reported in the literature.

  6. Synthesis and characterization of ZIF-69 membranes and separation for CO2/CO mixture

    KAUST Repository

    Liu, Yunyang

    2010-05-01

    Continuous and c-oriented ZIF-69 membranes were successfully synthesized on porous alpha-alumina substrates by an in situ solvothermal method. The membranes were characterized by XRD, SEM and single-gas permeation tests. The BET measurements on crystals taken from the same mother liquor that was used for membrane synthesis yield a Langmuir surface area of 1138 m(2)/g. The stability of the membrane towards heat and different solvents were studied. Single-gas permeation experiments through ZIF-69 membranes were carried out by a vacuum method at room temperature using H-2, CH4, CO, CO2 and SF6, respectively. The permeances were in the order of H-2 > CO2 > CH4 > CO > SF6. The separation of CO2/CO gas mixture was investigated by gas chromatograph (GC) and the permselectivity of CO2/CO was 3.5 +/- 0.1 with CO2 permeance of 3.6 +/- 0.3 x 10(-8) mol m(-2) s(-1) Pa-1 at room temperature. (C) 2010 Elsevier B.V. All rights reserved.

  7. Wall shear stress characterization of a 3D bluff-body separated flow

    Science.gov (United States)

    Fourrié, Grégoire; Keirsbulck, Laurent; Labraga, Larbi

    2013-10-01

    Efficient flow control strategies aimed at reducing the aerodynamic drag of road vehicles require a detailed knowledge of the reference flow. In this work, the flow around the rear slanted window of a generic car model was experimentally studied through wall shear stress measurements using an electrochemical method. The mean and fluctuating wall shear stress within the wall impact regions of the recirculation bubble and the main longitudinal vortex structures which develop above the rear window are presented. Correlations allow a more detailed characterization of the recirculation phenomenon within the separation bubble. In the model symmetry plane the recirculation structure compares well with simpler 2D configurations; specific lengths, flapping motion and shedding of large-scale vortices are observed, these similarities diminish when leaving the middle plane due to the strong three-dimensionality of the flow. A specific attention is paid to the convection processes occurring within the recirculation: a downstream convection velocity is observed, in accordance with 2D recirculations from the literature, and an upstream convection is highlighted along the entire bubble length which has not been underlined in some previous canonical configurations.

  8. Synthesis and Characterization of Quaternary Metal Chalcogenide Aerogels for Gas Separation and Volatile Hydrocarbon Adsorption

    KAUST Repository

    Edhaim, Fatimah A.

    2017-11-01

    In this dissertation, the metathesis route of metal chalcogenide aerogel synthesis was expanded by conducting systematic studies between polysulfide building blocks and the 1st-row transition metal linkers. Resulting materials were screened as sorbents for selective gas separation and volatile organic compounds adsorption. They showed preferential adsorption of polarizable gases (CO2) and organic compounds (toluene). Ion exchange and heavy metal remediation properties have also been demonstrated. The effect of the presence of different counter-ion within chalcogel frameworks on the adsorption capacity of the chalcogels was studied on AFe3Zn3S17 (A= K, Na, and Rb) chalcogels. The highest adsorption capacity toward hydrocarbons and gases was observed on Rb based chalcogels. Adopting a new building block [BiTe3]3- with the 1st-row transition metal ions results in the formation of three high BET surface area chalcogels, KCrBiTe3, KZnBiTe3, and KFeBiTe3. The resulting chalcogels showed preferential adsorption of toluene vapor, and remarkable selectivity of CO2, indicating the potential future use of chalcogels in adsorption-based gas or hydrocarbon separation processes. The synthesis and characterization of the rare earth chalcogels NaYSnS4, NaGdSnS4, and NaTbSnS4 are also reported. Rare earth metal ions react with the thiostannate clusters in formamide solution forming extended polymeric networks by gelation. Obtained chalcogels have high BET surface areas, and showed notable adsorption capacity toward CO2 and toluene vapor. These chalcogels have also been engaged in the absorption of different organic molecules. The results reveal the ability of the chalcogels to distinguish among organic molecules on their electronic structures; hence, they could be used as sensors. Furthermore, the synthesis of metal chalcogenide aerogels Co0.5Sb0.33MoS4 and Co0.5Y0.33MoS4 by the sol-gel method is reported. In this system, the building blocks [MoS4]2- chelated with Co2+ and (Sb3

  9. Influence study of flow separation on the nozzle vibration response

    Directory of Open Access Journals (Sweden)

    Geng Li

    2016-06-01

    Full Text Available In the present paper, the vibration response difference of the upper stage nozzle with higher expansion ratio between ground and altitude simulation hot-firing test is analyzed. It indicates that the acceleration response of the nozzle under ground hot-firing test is much higher than that of the altitude condition. In order to find the essential reason, the experimental and numerical simulation studies of the flow separation are developed by using the test engine nozzle. The experimental data show that the nozzle internal flow occurred flow separation and the divergence cone internal wall pressure pulsation increased significantly downstream from the separation location. The numerical simulation and experimental results indicate that the increase of internal wall pressure and turbulence pulsating pressure are the substantial reason of vibration response increasing aggravatingly during the ground firing test.

  10. Quark and Gluon Jet Separation and QCD Studies at CMS

    CERN Document Server

    AUTHOR|(CDS)2077240

    Jets are among the most studied structures at hadron colliders. Their importance is due to the fact that they are involved in a large number of processes, and that they retain some memory of the properties of the parton they originate from. The ability to separate quark jets from gluon jets is an important tool for signal discrimination in analyses containing jets in their final state, like some typical decays of the Higgs boson. This separation, however, is not completely achievable due to the statistical nature of hadronization. Using variables obtained from the CMS Particle Flow algorithm, which allow an accurate reconstruction of jets with a high granularity, we can exploit the structural differences between quark and gluon hadronization to derive a likelihood-based discriminant which statistically separates quark from gluon jets. The performance of the discriminator is tested both on real and simulated data; some typical problems arising from high luminosity of the LHC (pileup) are also taken into accoun...

  11. Study on the Effect of the Separating Unit Optimization on the Economy of Stable Isotope Separation

    Directory of Open Access Journals (Sweden)

    YANG Kun

    2015-01-01

    Full Text Available An economic criterion called as yearly net profit of single separating unit (YNPSSU was presented to evaluate the influence of structure optimization on the economy. Using YNPSSU as a criterion, economic analysis was carried out for the structure optimization of separating unit in the case of separating SiF4 to obtain the 28Si and 29Si isotope. YNPSSU was calculated and compared with that before optimization. The results showed that YNPSSU was increased by 12.3% by the structure optimization. Therefore, the structure optimization could increase the economy of the stable isotope separation effectively.

  12. Dielectric barrier discharge ionization in characterization of organic compounds separated on thin-layer chromatography plates.

    Directory of Open Access Journals (Sweden)

    Michał Cegłowski

    Full Text Available A new method for on-spot detection and characterization of organic compounds resolved on thin layer chromatography (TLC plates has been proposed. This method combines TLC with dielectric barrier discharge ionization (DBDI, which produces stable low-temperature plasma. At first, the compounds were separated on TLC plates and then their mass spectra were directly obtained with no additional sample preparation. To obtain good quality spectra the center of a particular TLC spot was heated from the bottom to increase volatility of the compound. MS/MS analyses were also performed to additionally characterize all analytes. The detection limit of proposed method was estimated to be 100 ng/spot of compound.

  13. Real-time shape-based particle separation and detailed in situ particle shape characterization.

    Science.gov (United States)

    Beranek, Josef; Imre, Dan; Zelenyuk, Alla

    2012-02-07

    Particle shape is an important attribute in determining particle properties and behavior, but it is difficult to control and characterize. We present a new portable system that offers, for the first time, the ability to separate particles with different shapes and characterize their chemical and physical properties, including their dynamic shape factors (DSFs) in the transition and free-molecular regimes, with high precision, in situ, and in real-time. The system uses an aerosol particle mass analyzer (APM) to classify particles of one mass-to-charge ratio, transporting them to a differential mobility analyzer (DMA) that is tuned to select particles of one charge, mobility diameter, and for particles with one density, one shape. These uniform particles are then ready for use and/or characterization by any application or analytical tool. We combine the APM and DMA with our single-particle mass spectrometer, SPLAT II, to form the ADS and demonstrate its utility to measure individual particle compositions, vacuum aerodynamic diameters, and particle DSFs in two flow regimes for each selected shape. We applied the ADS to the characterization of aspherical ammonium sulfate and NaCl particles, demonstrating that both have a wide distribution of particle shapes with DSFs from approximately 1 to 1.5. © 2012 American Chemical Society

  14. Heterogeneous glycoform separation by process chromatography: I: Monomer purification and characterization.

    Science.gov (United States)

    Li, Yi; Xu, Xuankuo; Shupe, Alan; Yang, Rong; Bai, Kevin; Das, Tapan; Borys, Michael C; Li, Zheng Jian

    2015-07-24

    Fc fusion proteins with high and low sialylation were purified and separated by preparative ion-exchange and hydrophobic interaction chromatography. Heterogeneity in sialylation and glycosylation led to variation in surface charge and hydrophobicity, and resulted in multiple distinct glycoform populations in response to various purification conditions. Monomer with high sialic acid content has higher surface charge and adsorbs stronger to ion-exchange resin, while the less sialylated monomer interacts more favorably with hydrophobic resin. Extensive biophysical characterization was carried out for purified monomers at different level of sialylation. In general, different monomeric glycoforms have different surface charge and hydrophobicity, different thermal stability, and different aggregation propensity. The surface charge corresponds well with sialic acid content, as evidenced by electrophoresis, N-link domain analysis, and zeta potential results. The sialylation also contributes to minor modification of protein size, molecular mass and tertiary structure. Notably, fluorescence emission spectra and thermal transition became less distinguishable when the monomers containing low and high sialic acid were prepared in high ionic strength solution. Such finding reiterates the fact that the electrostatic forces, which are largely dependent on sialic acid content of protein, plays a dominant role in many intra- and inter-molecular interactions. Overall, the characterization data agreed well with separation behaviors and provided valuable insight to control of glycoform profile in purification process. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. A Weldability Study of Structural Materials for Manufacturing Bearing Separators

    Directory of Open Access Journals (Sweden)

    V. S. Drizhov

    2016-01-01

    Full Text Available The aim is to analyze the possibility for using the 08YUT steel separator tape to manufacture separators, which are to be further applied to the bearing assembly via projection welding.Reliability of rolling bearings is determined by many factors such as surface quality of balls and rings and assembly precision, including the seal strength of hemiseparators.The technology based on the double-pulsed condenser projection welding belongs to one of the most efficient technologies to provide the assembly of bearing, for it allows welding of separator simultaneously in all currents. The paper shows that the required condition to assure high reliability of the bearing is induastial development and implementation of an effective and positive quality control system, which will reduce the probability of damages occurring both when welding and in the course of operation.The work used the static tensile test methods, as well as metallographic analysis.The experimental study used the 08YUT steel hemiseparators. A tape thickness of the hemiseparators was of 1.5mm. The number of simultaneously welded points were 8. The experimental studies of the metal damage of welding joints of the the 08YUT steel separator have shown that with a wide range of the changing welding current and compressed electrode force the quality assurance of welding points at the parent metal level could not be retrieved.The metallographic analysis of the metal damage nature of a welded joint revealed that between the atoms on the surfaces of hemiseparators there are no strong bonds – a bond was formed in the contact zone. This phenomenon leads to reduced tensile seal strength.The study has shown that aluminum and titanium added to the low-carbon steel in order to have a more fine-grained metal structure has a negative effect on the quality of welded joint via projection welding.

  16. Separability studies of construction and demolition waste recycled sand.

    Science.gov (United States)

    Ulsen, Carina; Kahn, Henrique; Hawlitschek, Gustav; Masini, Eldon A; Angulo, Sérgio C

    2013-03-01

    The quality of recycled aggregates from construction and demolition waste (CDW) is strictly related to the content of porous and low strength phases, and specifically to the patches of cement that remain attached to the surface of natural aggregates. This phase increases water absorption and compromises the consistency and strength of concrete made from recycled aggregates. Mineral processing has been applied to CDW recycling to remove the patches of adhered cement paste on coarse recycled aggregates. The recycled fine fraction is usually disregarded due to its high content of porous phases despite representing around 50% of the total waste. This paper focus on laboratory mineral separability studies for removing particles with a high content of cement paste from natural fine aggregate particles (quartz/feldspars). The procedure achieved processing of CDW by tertiary impact crushing to produce sand, followed by sieving and density and magnetic separability studies. The attained results confirmed that both methods were effective in reducing cement paste content and producing significant mass recovery (80% for density concentration and 60% for magnetic separation). The production of recycled sand contributes to the sustainability of the construction environment by reducing both the consumption of raw materials and disposal of CDW, particularly in large Brazilian centers with a low quantity of sand and increasing costs of this material due to long transportation distances. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. FABRICATION AND CHARACTERIZATION OF POLYIMIDE/POLYETHERSULFONE-FUMED SILICA MIXED MATRIX MEMBRANE FOR GAS SEPARATION

    Directory of Open Access Journals (Sweden)

    A. F. Ismail

    2012-01-01

    Full Text Available This study is performed primarily to investigate the feasibility of fumed silica as inorganic material towards gas separation performance of mixed matrix membrane. In this study, polyimide/polyethersulfone (PES-fumed silica mixed matrix membranes were casted using dry/wet technique. The results from the FESEM, DSC and FTIR analysis confirmed that the structure and physical properties of membrane is influenced by inorganic filler. FESEM’s cross-section view indicated good compatibility between polymer and fumed silica for all of range fumed silica used in this study. The gas separation performance of the mixed matrix membranes with fumed silica were relatively higher compared to that of the neat PI/PES membrane. PI/PES-fumed silica 5 wt% yielded significant selectivity enhancement of 7.21 and 40.47 for O2/N2, and CO2/CH4, respectively.

  18. Characterization of Microparticle Separation Utilizing Electrokinesis within an Electrodeless Dielectrophoresis Chip

    Directory of Open Access Journals (Sweden)

    Jr-Lung Lin

    2013-02-01

    Full Text Available This study demonstrated the feasibility of utilizing electrokinesis in an electrodeless dielectrophoresis chip to separate and concentrate microparticles such as biosamples. Numerical simulations and experimental observations were facilitated to investigate the phenomena of electrokinetics, i.e., electroosmosis, dielectrophoresis, and electrothermosis. Moreover, the proposed operating mode can be used to simultaneously convey microparticles through a microfluidic device by using electroosmotic flow, eliminating the need for an additional micropump. These results not only revealed that the directions of fluids could be controlled with a forward/backward electroosmotic flow but also categorized the optimum separating parameters for various microparticle sizes (0.5, 1.0 and 2.0 μm. Separation of microparticles can be achieved by tuning driving frequencies at a specific electric potential (90 Vpp·cm−1. Certainly, the device can be designed as a single automated device that carries out multiple functions such as transportation, separation, and detection for the realization of the envisioned Lab-on-a-Chip idea.

  19. Chromatographic Studies of Protein-Based Chiral Separations

    Science.gov (United States)

    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. Thermodynamic Studies to Support Actinide/Lanthanide Separations

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Linfeng [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-09-01

    This milestone report summarizes the data obtained in FY15 on the complexation of HEDTA with Np(V) and U(VI) in a temperature range from 25 to 70°C. The results show the effect of temperature on the chemical speciation of Np(V) and U(VI) in the modified TALSPEAK Process, and help to evaluate the effectiveness of the process when the operation envelope (e.g., temperature) varies. Eventually, the results from this study will help to achieve a better control of the separation process based on the HEDTA/HEH[EHP] combination.

  1. Synthesis and characterization of imprinted sorbent for separation of gramine from bovine serum albumin

    Energy Technology Data Exchange (ETDEWEB)

    Luliński, Piotr; Klejn, Dorota; Maciejewska, Dorota, E-mail: dmaciejewska@wum.edu.pl

    2016-08-01

    The aim of this study was to develop an efficient sorbent for separation of N,N-dimethyl-3-aminomethylindole (gramine) from bovine serum albumin. An imprinting technology was involved in the synthesis of polymers from nine different functional monomers in the presence of ethylene glycol dimethacrylate as a cross-linker. The analysis of binding capacities showed that the highest specificity towards gramine was achieved when 4-vinylbenzoic acid was used as the functional monomer in methanol to form the bulk imprinted polymer, MIP1 (imprinting factor equal to 21.3). The Scatchard analysis of MIP1 showed two classes of binding sites with the dissociation constants K{sub d} equal to 0.105 and 6.52 μmol L{sup −1}. The composition and morphology of polymers were defined by {sup 13}C CP/MAS NMR, BET and SEM-EDS analyses. The recognition mechanism of MIP1 was tested using the structurally related bioanalytes, and the dominant role of indole moiety and ethylamine side chain was revealed. A new MISPE protocol was optimized for separation of gramine. The total recoveries on MIP1 were equal to 94 ± 12 % from standard solutions and 85 ± 11 % from bovine serum albumin. - Highlights: • Indole alkaloid (gramine) imprinted polymer was synthesized. • Very high specifity of sorbent towards gramine was achieved. • Physico-chemical characteristics of novel material was presented. • Efficient MISPE protocol was proposed for separation of gramine from model sample.

  2. Separation and characterization of maternal cardiac and vascular sounds in the third trimester of pregnancy

    DEFF Research Database (Denmark)

    Riknagel, Diana; Zimmermann, Henrik; Farlie, Richard

    2017-01-01

    OBJECTIVE: To characterize the vascular sounds of the uteroplacental blood flow obtained by microphones. METHODS: The present retrospective study took place in an anechoic chamber facility at Aalborg University, Aalborg, Denmark, in 2012, and included pregnant participants aged 18-40 years...

  3. Characterization of Passive Flow-Actuated Microflaps Inspired by Shark Skin for Separation Control

    Science.gov (United States)

    Morris, Jackson; Devey, Sean; Lang, Amy; Hubner, Paul

    2017-11-01

    Thanks to millions of years of natural selection, sharks have evolved into quick apex predators. Previous research has proven shark skin to reduce flow separation, which would result in lower pressure drag. Mako shark skin is made up of microscopic scales on the order of 0.2 mm in size. These scales are hypothesized to be a flow control mechanism, capable of being passively actuated by reversed flow. We believe shark scales are strategically sized to interact with the lower 5 percent of the boundary layer, where reversed flow occurs near the wall. Previous wind tunnel research has shown that it is possible to passively actuate 2D flaps in the lower regions of the boundary layer. This research aims to identify reverse flow conditions that will cause small 3D flaps to actuate. Several sets of microflaps (about 4 mm in length) geometrically similar to shark scales were 3D printed. These microflaps were tested in a low-speed wind tunnel in various reverse flow conditions. Microflaps were observed to be actuated by the reversing flow and flow conditions were characterized using a hot-wire probe. These microflaps have the potential to mimic the mako shark type of flow control in air, passively actuated by reverse flow conditions. This research was supported by Boeing, the US Army, and the National Science Foundation REU program.

  4. Synthesis and characterization of a porous and hydrophobic cellulose-based composite for efficient and fast oil-water separation.

    Science.gov (United States)

    Wang, Xiangyun; Xu, Shimei; Tan, Yun; Du, Juan; Wang, Jide

    2016-04-20

    Oily wastewater is generated in diverse industrial processes, and its treatment has become crucial due to increasing environmental concerns. Herein, silanized cellulose was prepared by sol-gel reaction between microcrystalline cellulose (MCC) and hexadecyltrimethoxysilane (HDTMS) using for oil-water separation. The silanized cellulose was characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). A higher mass ratio of HDTMS to MCC made silanized cellulose become looser, and showed lower water absorbency. The silanized cellulose exhibited specific separation performance towards vegetable oil-water mixture (not for mineral oil-water mixture) with separation efficiency of 99.93%. Moreover, the separation was fast with a water flux of 4628.5Lm(-2)h(-1). The separation efficiency still remained at 99.77% even after recycling for 10 times. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Characterization of two novel sialyl N-acetyllactosaminyl nucleotides separated from ovine colostrum

    OpenAIRE

    Sasaki, Masashi; Nakamura, Tadashi; Hirayama, Kentaro; Fukuda, Kenji; Saito, Tadao; Urashima, Tadasu; Asakuma, Sadaki

    2016-01-01

    The milk/colostrum of some mammalian species is known to contain sugar nucleotides including uridine diphosphate (UDP) oligosaccharides in addition to lactose and milk oligosaccharides, but the detailed structures of these UDP oligosaccharides have not so far been clarified. In this study we isolated two UDP-sialyl N-acetyllactosamines from ovine colostrum and characterized them using H-1-NMR and MALDITOFMS spectroscopies. Their structures were found to be Neu5Gc(alpha 2 - 3) Gal (beta 1 - 4)...

  6. Separation, Characterization and Fouling Potential of Sludge Waters from Different Biological Wastewater Treatment Processes

    KAUST Repository

    Xue, Jinkai

    2011-07-01

    The major limitation, which hinders the wider application of membrane technology and increases the operating costs of membranes involved in wastewater treatment plants, is membrane fouling induced by organic matter. Extracellular polymeric products (EPS) and soluble microbial products (SMP) are the two most mentioned major foulants in publications, for which the debate on precise definitions seems to be endless. Therefore, a concept of sludge water, which conceptually covers both EPS and SMP, has been developed in this research. A standard procedure of sludge water separation, which is centrifugation at 4000g for 15 min followed by 1.2μm glass fiber filter filtration, was established based on separation experiments with membrane tank sludge from the KAUST MBR wastewater treatment plant. Afterwards, sludge waters from the KAUST MBR WWTP anoxic tank, aerobic tank and membrane tank as well as sludge waters from the Jeddah WWTP anoxic tank, aerobic tank and secondary effluent were produced through the previously developed standard procedure. The obtained sludge water samples were thereafter characterized with TOC/COD, LC-­‐OCD and F-­‐EEM, which showed that KAUST anoxic/ aerobic /membrane tank sludge waters had similar characteristics for all investigated parameters, yet the influent naturally had a higher DOC and biopolymer concentration. Moreover, lower TOC/COD, negligible biopolymers and low levels of humics were found in KAUST effluent. Compared with the KAUST MBR WWTP, the Jeddah WWTP’s sludge waters generally had higher DOC and biopolymer concentrations. To investigate sludge water fouling potential, the KAUST membrane tank sludge water as well as the Jeddah secondary effluent were filtrated through a membrane array consisting of an ultrafiltration (UF) Millipore RC10kDa at the first step followed by a nanofiltration (NF) KOCH Acid/Base stable NF200 at the second step. It was found that cake layer and standard blocking occurred simultaneously during both

  7. Enhanced Landfill Mining case study: Innovative separation techniques

    Science.gov (United States)

    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

  8. Separation of Cd and Ni from multicomponent aqueous solutions by nanofiltration and characterization of membrane using IT model

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhari, Latesh B. [Department of Chemical Engineering, S.V. National Institute of Technology, Surat 395007, Gujarat (India); Department of Chemical Engineering, N.G. Patel Polytechnic, Isroli-Afwa, Tal. Bardoli, Dist. Surat 394620, Gujarat (India); Murthy, Z.V.P., E-mail: zvpm2000@yahoo.com [Department of Chemical Engineering, S.V. National Institute of Technology, Surat 395007, Gujarat (India)

    2010-08-15

    Removal of heavy metals from wastewater is of critical importance due to their high toxicity and tendency to accumulate in living organisms. In the present work, performance of a nanofiltration (NF) membrane has been studied to separate cadmium and nickel ions from multicomponent aqueous solutions at different operating conditions. It is observed that the separation of cadmium and nickel ions increases with increase in applied pressure and decreases with increase in feed concentration at a constant feed flow rate. The maximum observed solutes rejection of cadmium and nickel ions are 80.57% and 85.27% for CdCl{sub 2}-NiCl{sub 2}-water system and 97.26% and 98.90% for CdSO{sub 4}-NiSO{sub 4}-water system, respectively, for an initial feed concentration of 0.005 g/L. This difference in rejection is due to the charge density of the anions. It is also observed that the order of solute rejection sequence is inversely proportional to the diffusion coefficient. The NF membrane is characterized by an irreversible thermodynamics (IT) based Spiegler-Kedem model, coupled with film theory. Boundary-layer thickness and membrane transport parameters are estimated using Levenberg-Marquadt method. The estimated parameters are used to predict the membrane performance and found that the predicted values are in satisfactory agreement with the experimental results.

  9. Preparation and characterization of new zeolite membranes. Application to gaseous separation; Preparation et caracterisation de nouvelles membranes de zeolithe application a la separation gazeuse

    Energy Technology Data Exchange (ETDEWEB)

    Anstett, M.

    1996-11-25

    Zeolites are interesting for the preparation of inorganic membranes which could be used for the continuous separation of gas and liquids by gas permeation and pervaporation. Zeolites membranes are obtained by hydrothermal synthesis and are characterized by XRD, SEM, TDA, IR, chemical analysis, EPMA, NMR, MAS NMR and gas permeation. After some tests of preparation of zeolite CHA and MFI self supporting membranes, the work is turned towards the preparation of zeolite MFI membranes supported by porous disks or {alpha} alumina, glass and tubes of carbon covered with a thin layer or zirconium dioxide. It is shown that the characteristics of the support (reactivity, pores dimensions, ...) strongly influence the quality of the prepared membrane. Two originals preparation processes are finalized. For the alumina disks, a gel precursor of zeolite is firs formed at the surface of the support by immersing successively that support in two non miscible liquids before the crystallisation. The gel is then converted into the zeolite by contact with water vapor. The zeolite layer obtained is localized at the surface of the support and present not only at the outside but also at the inside of the support. The characteristics of the zeolite layer can be controlled and the method can be adapted to various porous supports. The membrane obtained is interesting for hydrocarbons separations, for example the separation of methane and isobutane. In the case of Vycor glass disks, the reactivity of the support is first enhanced by contact with saturated water vapour. The temperature of the synthesis is then chosen relatively low in order to limit the attack of the support. With that method, a basic solution can be used without degradation of the support.The basicity leads to the formation of little crystals whose assembling is compact and homogeneous. The membrane obtained is interesting for example for the separation of normal butane and isobutane. (author) 71 refs.

  10. Separation and Loss: A Study on the Impact of Divorce

    Directory of Open Access Journals (Sweden)

    Janaina Andrade Tenório Araújo

    2016-11-01

    Full Text Available This article emerged starting of a search that had as aimed to understand the feelings that emerge in men and women when they lose marital bond. It was carried under a qualitative basis and counted on the participation of three men and four women, all divorced. The tool used was the semi-structured interview and the collected data was submitted to the Thematic Content Analysis. This analysis led to the conception of two categories: the emerging emotions and feelings in the loss context due to the divorce and the repercussions of such loss about the personal identity. The results indicated that searching and establishing a new affective bond was a strategy used by the participants involved in the study, in order to strengthen and support the resignification of their personal identity. The majority of the interviewees earned such resignification by becoming independent and capable of developing their own potentialities. About the feelings and emotions lived through the critical period of separation; they ranged from “happiness and peace” to “failure and sadness”.

  11. Calixarene receptors in the selective separation of alachlor. Characterization of the separated complexes; Receptores calixarenicos en la separacion selectiva de alaclor. Caracterizacion de los complejos separados

    Energy Technology Data Exchange (ETDEWEB)

    Garcia G, M.C

    2004-07-01

    Pesticides have been necessary in the agriculture since the plagues control have been remedied thanks to them but it has also provoked pollution. Nowadays, there are several methods which help to decrease or remedy such a pollution provoked. Unfortunately, any of them work out the environmental problem totally. Therefore, alternatives have to be found. The organic and tri dimensional characteristics of these macrocycles afford them a high versatility in such a way that these hosts can interact with organic guests selectively. Alachlor is a chlorinated organic herbicide useful in the plagues control of annual grasses and many broad-leave weeds which grow in maize, peanuts and soyabean. The ability of calixarenes to host organic guests with chemical characteristics similar to pesticides let them to be good candidates to compete with others methods which are used presently to separate organic pesticides. In this direction one of the advantages of proposing the use of calixarenes is, its facility of being modified in the lower and/or upper rims, to adapt them to aqueous, organic, gaseous and aqueous-organic media. Once the characteristics of reagents informed in the literature were confirmed and complemented with others found in this work, we studied, in solution, the interaction of the calixarenes with alachlor using 1 x 10{sup -5} to 1 x 10{sup -3} M solutions in acetonitrile for calixarenes fitted with phosphinoyl pendant arms in the lower rim, B{sub n}bL{sup n}, n= 4, 6) and in chloroform for parents calixarenes (H{sub n}bL{sup n} n = 4, 6, 8). Meticulous studies monitored by UV-Vis and luminescence were carried out, and the best stoichiometry to be used in further studies resulted to be 1(host): 1(alachlor). Therefore, we chose the 1 x 10{sup -4} M concentration to find how long the host-guest should be interacting in order to guarantee the formation in solution of the calixarene-alachlor species. It was found 168 h for the alachlor-B{sub n}bL{sup n} interaction

  12. Improving class separability using extended pixel planes: a comparative study.

    Science.gov (United States)

    Orlov, Nikita V; Eckley, D Mark; Shamir, Lior; Goldberg, Ilya G

    2012-09-01

    In this work we explored class separability in feature spaces built on extended representations of pixel planes (EPP) produced using scale pyramid, subband pyramid, and image transforms. The image transforms included Chebyshev, Fourier, wavelets, gradient and Laplacian; we also utilized transform combinations, including Fourier, Chebyshev and wavelets of the gradient transform, as well as Fourier of the Laplacian transform. We demonstrate that all three types of EPP promote class separation. We also explored the effect of EPP on suboptimal feature libraries, using only textural features in one case and only Haralick features in another. The effect of EPP was especially clear for these suboptimal libraries, where the transform-based representations were found to increase separability to a greater extent than scale or subband pyramids. EPP can be particularly useful in new applications where optimal features have not yet been developed.

  13. Characterization of polysorbate 85, a nonionic surfactant, by liquid chromatography vs. ion mobility separation coupled with tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Solak Erdem, Nilüfer; Alawani, Nadrah; Wesdemiotis, Chrys, E-mail: wesdemiotis@uakron.edu

    2014-01-15

    Graphical abstract: -- Highlights: •Liquid chromatography (LC) separates amphiphilic blends according to hydrophobicity. •Ion mobility (IM) spectrometry separates these blends based on molecular size/shape. •LC–MS provides the separation resolution needed for quantifying fatty acid content. •IM–MS enables rapid, solvent-free separation and the detection of trace components. •With either method, tandem MS allows to count the hydrophobic substituents. -- Abstract: Liquid chromatography (LC) and ion mobility (IM) separation have been coupled with mass spectrometry (MS) and tandem mass spectrometry (MS{sup 2}) to characterize a commercially important nonionic surfactant, polysorbate 85. The constituents of this amphiphilic blend contained a sorbitan or isosorbide core that was chain extended with poly(ethylene oxide) (PEO) and partially esterified at the PEO termini with oleic acid or, to a lesser extent, other fatty acids. Using interactive LC in reverse-phase mode, the oligomers of the surfactant were separated according to their hydrophobicity/hydrophilicity balance. On the other hand, IM spectrometry dispersed the surfactant oligomers by their charge and collision cross section (i.e. size/shape). With either separation method, an increased number of fatty ester groups and/or lack of the polar sorbitan (or isosorbide) core led to higher retention/drift times, enabling the separation of isobaric species or species with superimposed isotope patterns, so that their ester content could be conclusively identified by MS{sup 2}. LC–MS and IM–MS permitted the detection of several byproducts besides the major PEO-sorbitan oleate oligomers. LC–MS provides the separation resolution needed for quantitative determination of the degree of esterification. IM–MS, which minimizes analysis time and solvent use, is ideally suitable for a fast, qualitative survey of samples differing in their minor constituents or impurities.

  14. Using a Microscale Approach to Rapidly Separate and Characterize Three Photosynthetic Pigment Species from Fern

    Science.gov (United States)

    Ayudhya, Theppawut Israsena Na; Posey, Frederick T.; Tyus, Jessica C.; Dingra, Nin N.

    2015-01-01

    A rapid separation of three photosynthetic pigments (chlorophyll "a" and "b" and xanthophyll) from fern ("Polystichum acrostichoides") is described using microscale solvent extraction and traditional thin layer chromatography that minimizes use of harmful chemicals and lengthy procedures. The experiment introduces…

  15. Characterization of composite cellulosic separators for rechargeable lithium-ion batteries

    Science.gov (United States)

    Kuribayashi, Isao

    Thin composite cellulosic separators (39-85 lem thickness), composed of fine fibrilliform cellulosic fibres (diameter 0.5 to 5.0 μm) embedded in microporous (pore diameter: 10-200 nm) cellulosic film and soaked in ethylene carbonate or other aprotic solvent, are found to possess fair-to-moderate physical strength, an apparent complete freedom from pinholes, and a complex impedance equal to or lower than that of conventional polyolefin separators for rechargeable lithium-ion batteries. Laboratory-scale cells that comprise LiCoO 2/petroleum coke electrodes, 1.0 M LiBF 4/PC:EC:BL (25:25:50 by volume, propylene carbonate:ethylene carbonate: γ-butyrolactone) electrolyte and the cellulosic separators exhibit good initial discharge capacity and capacity retention over 41 charge/discharge cycles. The latter are indistinguishable from those obtained from a similar cell with conventional polyolefin separator.

  16. Chromatographic separation and partial characterization of microbial low-molecular-weight proteinase inhibitors.

    Science.gov (United States)

    Kourteva, I

    1988-07-27

    A crude preparation, inhibiting trypsin (T), chymotrypsin (C) and papain (P), was isolated from the culture filtrate of Actinomyces sp. 9 by butanol extraction. Ion-exchange high-performance liquid chromatography (HPLC) of this preparation on a Mono S column resulted in the separation of two inhibitory fractions: one active against T (TI-9) and the other active against C and P (CPI-9). These two fractions, having the same inhibitory specificity, were also obtained from the crude extract by size-exclusion HPLC on a Superose 12 column. This method proved to be better in terms of the purity of the fractionated inhibitors than ion-exchange chromatography. Further purification of TI-9 and CPI-9 was achieved by using reversed-phase HPLC on a PEP RPC column. In this case, TI-9 was obtained as an apparently homogeneous peak. Studies on the physicochemical properties of the purified inhibitors showed them to be small molecules, similar in hydrophobicity, pH and thermal stability, but differing in solubility. Amino acid and spectral analyses provided the peptidic structure of TI-9 and gave a molecular weight of 1643, while parallel analyses of CPI-9 showed that it lacks the common amino acids.

  17. Characterization of two novel sialyl N-acetyllactosaminyl nucleotides separated from ovine colostrum.

    Science.gov (United States)

    Sasaki, Masashi; Nakamura, Tadashi; Hirayama, Kentaro; Fukuda, Kenji; Saito, Tadao; Urashima, Tadasu; Asakuma, Sadaki

    2016-10-01

    The milk/colostrum of some mammalian species is known to contain sugar nucleotides including uridine diphosphate (UDP) oligosaccharides in addition to lactose and milk oligosaccharides, but the detailed structures of these UDP oligosaccharides have not so far been clarified. In this study we isolated two UDP-sialyl N-acetyllactosamines from ovine colostrum and characterized them using (1)H-NMR and MALDI-TOFMS spectroscopies. Their structures were found to be Neu5Gc(α2-3)Gal(β1-4)GlcNAcα1-UDP and Neu5Gc(α2-6)Gal(β1-4)GlcNAcα1-UDP.

  18. A numerical study of separation on a spheroid at incidence

    Science.gov (United States)

    Rosenfeld, M.; Israeli, M.; Wolfshtein, M.

    1986-01-01

    The three-dimensional incompressible, steady and laminar flow field around a prolate spheroid at incidence is considered. The parabolized Navier-Stokes equations are solved numerically. The method can handle vortex types as well as bubble type flow separation because the pressure is one of the dependent variables. Here, the distribution of the skin friction is reported for two test cases. The first test case is a prolate spheroid of aspect ratio of 4:1 at 6 degrees incidence and Reynolds number of 1 million (based on half the major axis). The second case is a spheroid with a 6:1 aspect ratio at 10 degrees incidence and Reynolds number of 0.8 x 1 million. The properties of the flow field near the body are discussed on the basis of the pattern of the skin friction lines, and the shape of the separation lines. Favorable agreement with experimental results is obtained.

  19. a Study of Pairing Interaction in a Separable Form

    Science.gov (United States)

    Tian, Yuan; Ma, Zhongyu; Ring, P.

    2008-04-01

    The pairing force of Gogny in the 1S0 channel has been applied with great success in many applications in finite nuclei. It is of finite range and therefore rather complicated. Based on this force, we propose a new rather simple pairing interaction, which has basically the same properties as the Gogny force. It is separable in momentum space, translational invariant and, as the Gogny force of finite range. Using techniques of Talmi and Moshinsky, we show, that it can be represented as a sum of separable terms in oscillator space, which converges quickly. Because of its separability it is very easy to handle. It is fully determined by the Gogny force. It is used for the calculation of pairing properties of finite nuclei in the Relativistic Hartree Bogoliubov (RHB) approach. It is found that this new force can well depict the pairing properties on almost the same footing as the original pairing interaction not only in nuclear matter, but also in finite nuclei. This simple force can be easily applied in the calculation of deformed nuclei, and the investigation of pairing properties in nuclei close to the drip lines as well as for further investigations going beyond mean field.

  20. Application of directly coupled HPLC MMR to separation and characterization of lipoproteins from human serum

    DEFF Research Database (Denmark)

    Daykin, C. A.; Corcoran, O.; Hansen, S. H.

    2001-01-01

    with plasma proteins such as albumin occurred, and this clearly limits quantitation of that species by HPLC peak integration. We also show, for the first time, the application of directly coupled HPLC H-1 NMR spectroscopy to confirm the identification of the three major lipoproteins, The full chromatographic...... by the HPLC separation and that their gross supramolecular organization was intact....

  1. Orthogonal Separation Techniques for the Characterization of the Yeast Nuclear Proteome

    NARCIS (Netherlands)

    Gauci, Sharon; Veenhoff, Liesbeth M.; Heck, Albert J. R.; Krijgsveld, Jeroen

    The presence of the nucleus is the distinguishing feature of eukaryotic cells, separating the genome from the cytoplasm. Key cellular events, including transcription, DNA replication, RNA-processing and ribosome biogenesis all take place in the nucleus. All of these processes can be regulated

  2. Studies on semi-technical separation of Mung bean starch

    Energy Technology Data Exchange (ETDEWEB)

    Haase, N.U.; Tegge, G.; Thu, N.M. (Bundesforschungsanstalt fuer Getreide- und Kartoffelverarbeitung, Detmold (Germany, F.R.))

    1991-02-01

    Starch of mung beans is the raw material for high grade glass noodles, but until now industrial starch separation is often less efficient. For testing new fields of commercial use it is of benerfit to experiment with very pure starches. Regarding this, possibilities of starch isolation on a semi-technical scale are described, which resulted in most pure starches. Crude protein content could be lowered down to 0.3% and crude fibre content down to 0.5% dry matter base. (orig.).

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Identification and characterization of a peptidoglycan hydrolase, MurA, of Listeria monocytogenes, a muramidase needed for cell separation.

    Science.gov (United States)

    Carroll, Shannon A; Hain, Torsten; Technow, Ulrike; Darji, Ayub; Pashalidis, Philippos; Joseph, Sam W; Chakraborty, Trinad

    2003-12-01

    A novel cell wall hydrolase encoded by the murA gene of Listeria monocytogenes is reported here. Mature MurA is a 66-kDa cell surface protein that is recognized by the well-characterized L. monocytogenes-specific monoclonal antibody EM-7G1. MurA displays two characteristic features: (i) an N-terminal domain with homology to muramidases from several gram-positive bacterial species and (ii) four copies of a cell wall-anchoring LysM repeat motif present within its C-terminal domain. Purified recombinant MurA produced in Escherichia coli was confirmed to be an authentic cell wall hydrolase with lytic properties toward cell wall preparations of Micrococcus lysodeikticus. An isogenic mutant with a deletion of murA that lacked the 66-kDa cell wall hydrolase grew as long chains during exponential growth. Complementation of the mutant strain by chromosomal reintegration of the wild-type gene restored expression of this murein hydrolase activity and cell separation levels to those of the wild-type strain. Studies reported herein suggest that the MurA protein is involved in generalized autolysis of L. monocytogenes.

  5. SEPARATION AND CHARACTERIZATION OF NEW CELLULOSIC FIBRES FROM THE JUNCUS ACUTUS L PLANT

    OpenAIRE

    Amel El Ghali,; Imed Ben Marzoug,; Mohamed Hassen V Baouab,; Mohamed Sadok Roudesli

    2012-01-01

    Cellulose fibres from the Juncus acutus L plant were isolated and characterized. The isolation of the fibres was performed by sequential NaOH treatment and H2O2 bleaching under different extraction conditions. The chemical and surface morphological structures of the Juncus acutus L fibres were characterized with FTIR, SEM, AFM, DSC, surface energy, diameter, density, and lignin content determination. Changes in structure and properties of the obtained fibres were observed by varying the conce...

  6. Preparation and Characterization of Silicone Liquid Core/Polymer Shell Microcapsules via Internal Phase Separation

    DEFF Research Database (Denmark)

    Gonzalez, Lidia; Kostrzewska, Malgorzata; Ma, Baoguang

    2014-01-01

    Microcapsules with a silicone liquid core surrounded by a polymeric shell were synthesisedthrough the controlled phase separation. The dispersed silicone phase consisted of the shellpolymer PMMA, a good solvent for the PMMA (dichloromethane, DCM) and a poor solvent(methylhydrosiloxane dimethylsil......Microcapsules with a silicone liquid core surrounded by a polymeric shell were synthesisedthrough the controlled phase separation. The dispersed silicone phase consisted of the shellpolymer PMMA, a good solvent for the PMMA (dichloromethane, DCM) and a poor solvent......(methylhydrosiloxane dimethylsiloxane) for thePMMA. The morphology of the PMMA micro-capsules was investigated by ATR-FTIR and byoptical microscopy. Microcapsules were preparedwith different emulsifiers and different concen-trations of acetone and PMMA in the oil phase.The thermal stability of the PMMA microcapsuleand the content...... of the silicone oil core wereassessed by TGA.1H-NMR spectroscopy and anextraction method were also used to determine the content of the silicone liquid core in the microcapsules....

  7. High-performance liquid chromatography of bile pigments: separation and characterization of the urobilinoids.

    Science.gov (United States)

    Bull, R V; Lim, C K; Gray, C H

    1981-11-20

    The detailed analysis of faecal bile pigments by high-performance liquid chromatography is described. Non-aqueous reversed-phase systems with acetonitrile-dimethyl sulphoxide or acetonitrile-dimethyl sulphoxide-methanol as the mobile phase on C1, C8 or C18-bonded silica are used for the group separation of verdinoids, violinoids and urobilinoids. A silica column, with acetonitrile-water-tetraethylene-pentamine as mobile phase, separates the laevorotatory stercobilin (C33H46N4O6) and half-stercobilin (C33H44N4O6) from the optically inactive urobilin (C33H42N4O6). The diastereoisomers are resolved by converting the urobilinoids into their dimethyl esters before chromatography on a silica column with n-heptane-methyl acetate-methanol containing 1% of diethylamine as the solvent system.

  8. New graph classes characterized by weak vertex separators and two-pairs

    Directory of Open Access Journals (Sweden)

    Terry A. McKee

    2017-04-01

    Full Text Available A set of vertices whose deletion from a graph would increase the distance between two remaining vertices is called a weak vertex separator of the graph. Two vertices form a two-pair if all chordless paths between them have length 2. I prove that every inclusion-minimal weak vertex separator of every induced subgraph of a graph G induces a complete subgraph if and only if nonadjacent vertices of induced C4 subgraphs of G always form two-pairs of G; moreover, this is also true when “complete” and C4 are replaced with “edgeless” and K4−e (≅K1,1,2. The first of the resulting new graph classes generalizes chordal graphs, and the second generalizes unichord-free graphs; they both generalize distance-hereditary graphs and geodetic graphs.

  9. Characterization of silver nanoparticles-alginate complexes by combined size separation and size measurement techniques.

    Science.gov (United States)

    António, Diana C; Cascio, Claudia; Gilliland, Douglas; Nogueira, António J A; Rossi, François; Calzolai, Luigi

    2016-12-16

    The detection and quantification of nanoparticles is a complex issue due to the need to combine "classical" identification and quantification of the constituent material, with the accurate determination of the size of submicrometer objects, usually well below the optical diffraction limit. In this work, the authors show that one of the most used analytical methods for silver nanoparticles, asymmetric flow field-flow fractionation, can be strongly influenced by the presence of dissolved organic matter (such as alginate) and lead to potentially misleading results. The authors explain the anomalies in the separation process and show a very general way forward based on the combination of size separation and size measurement techniques. This combination of techniques results in more robust AF4-based methods for the sizing of silver nanoparticles in environmental conditions and could be generally applied to the sizing of nanoparticles in complex matrices.

  10. Characterization of magnetic ion-exchange composites for protein separation from biosuspensions.

    Science.gov (United States)

    Käppler, Tobias E; Hickstein, Birgit; Peuker, Urs A; Posten, Clemens

    2008-06-01

    Downstream processing is a major issue in biotechnological production. A multitude of unit operations with nonsatisfying yield are often used to reach the desired product purity. Direct recovery technologies such as high-gradient magnetic fishing (HGMF) are advantageous because of their ability to separate the desired product in early stages from crude cultivation broths. However, the use of magnetic particles to capture valuable biotechnological products is often linked to the drawback that support particles are expensive and not available in greater quantities. This current work presents new composite magnetic particles that can be used in biotechnology. They are manufactured by a spray drying process. During this process, the nanosized magnetite particles as well as functional ion-exchange nanoparticles are integrated into one particle in which they are linked by a matrix polymer. The production procedure is flexible, scalable, and therefore economical. These particles have good adsorption capacities of up to 85 mg/g adsorbed protein and good binding kinetics. They are resistant to harsh conditions such as short ultrasonic treatment or extreme pHs. In order to test their usefulness in biosuspensions, model proteins were separated using these particles. The anion and cation exchanger particles separated lysozyme (LZ) or BSA from cultivation suspensions. The selectivity of recovery was dependent on other proteins present as is usual for ion-exchange binding mechanisms.

  11. Oxidation, characterization, and separation of non-pertechnetate species in Hanford wastes

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, N.C. [Los Alamos National Lab., NM (United States)

    1997-10-01

    Under DOE`s privatization initiative, Lockheed Martin and British Nuclear Fuels Limited are preparing to stabilize the caustic tank waste generated from plutonium production at the Hanford Site. Pretreatment of Hanford tank waste will separate it into low-level waste (LLW) and high-level waste (HLW) fractions. The scope of the technetium problem is indicated by its inventory in the waste: {approximately}2000 kg. Technetium would normally exist as the pertechnetate anion, TcO{sub 4}{sup {minus}}, in aqueous solution. However, evidence obtained at Los Alamos National Laboratory (LANL) indicates that the combination of radiolysis, heat, organic complexants, and time may have reduced and complexed a significant fraction of the technetium in the tank waste. These species are in a form that is not amenable to current separation techniques based on pertechnetate removal. Thus, it is crucial that methods be developed to set technetium to pertechnetate so these technologies can meet the required technetium decontamination factor. If this is not possible, then alternative separation processes will need to be developed to remove these non-pertechnetate species from the waste. The simplest, most cost-effective approach to this problem is to convert the non-pertechnetate species to pertechnetate. Chemical, electrochemical, and photochemical oxidation methods, as well as hydrothermal treatment, are being applied to Hanford waste samples to ensure that the method works on the unknown technetium species in the waste. The degree of oxidation will be measured by determining the technetium distribution coefficient, {sup Tc}K{sub d}, between the waste and Reillex{trademark}-HPQ resin, and comparing it to the true pertechnetate K{sub d} value for the waste matrix. Other species in the waste, including all the organic material, could be oxidized by these methods, thus selective oxidation is desirable to minimize the cost, time, and secondary waste generation.

  12. Recent advances in chromatographic separation and spectroscopic characterization of the higher fullerenes C76 and C84.

    Science.gov (United States)

    Jovanovic, T; Koruga, Dj

    2014-01-01

    The basic and the higher fullerenes were chromatographically isolated from the obtained series of carbon soot extracts, in increased yields, by the new, advanced methods, on Al2O3 columns. The elution was performed continuously, in one phase of each process, at ambient conditions, with the several different original hexane-toluene gradients. Various separation systems were used previously. The unique and the main, dominant absorption maxima of the purified higher fullerenes were registered in the spectral regions where they intensively absorb, applying the IR and UV/VIS techniques. All the observed absorption bands are in excellent agreement with theoretical calculations, indicating the achieved advancement in chromatographic separation and spectroscopic characterization. The isolated fullerenes are important for investigation of their remarkable optical and electronic properties, as well as for the numerous possible applications in chemistry, physics, biomedicine, diagnostic and therapeutic agents, sensors, polymers, nanophotonic materials, special lenses, optical limiting, organic field effect transistors, solar cells etc.

  13. Separation and characterization of oxidized isomeric lipid-peptide adducts by ion mobility mass spectrometry.

    Science.gov (United States)

    Milic, Ivana; Kipping, Marc; Hoffmann, Ralf; Fedorova, Maria

    2015-12-01

    Phospholipids are major components of cell membranes and lipoprotein complexes. They are prone to oxidation by endogenous and exogenous reactive oxygen species yielding a large variety of modified lipids including small aliphatic and phospholipid bound aldehydes and ketones. These carbonyls are strong electrophiles that can modify proteins and, thereby, alter their structures and functions triggering various pathophysiological conditions. The analysis of lipid-protein adducts by liquid chromatography-MS is challenged by their mixed chemical nature (polar peptide and hydrophobic lipid), low abundance in biological samples, and formation of multiple isomers. Thus, we investigated traveling wave ion mobility mass spectrometry (TWIMS) to analyze lipid-peptide adducts generated by incubating model peptides corresponding to the amphipathic β1 sheet sequence of apolipoprotein B-100 with 1-palmitoyl-2-(oxo-nonanoyl)-sn-glycerophosphatidylcholine (PONPC). The complex mixture of peptides, lipids, and peptide-lipid adducts was separated by TWIMS, which was especially important for the identification of two mono-PONPC-peptide isomers containing Schiff bases at different lysine residues. Moreover, TWIMS separated structural conformers of one peptide-lipid adduct possessing most likely different orientations of the hydrophobic sn-1 fatty acyl residue and head group of PONPC, relative to the peptide backbone. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Separation and characterization of alpha-chain subunits from tilapia (Tilapia zillii) skin gelatin using ultrafiltration.

    Science.gov (United States)

    Chen, Shulin; Tang, Lanlan; Su, Wenjin; Weng, Wuyin; Osako, Kazufumi; Tanaka, Munehiko

    2015-12-01

    Alpha-chain subunits were separated from tilapia skin gelatin using ultrafiltration, and the physicochemical properties of obtained subunits were investigated. As a result, α1-subunit and α2-subunit could be successfully separated by 100 kDa MWCO regenerated cellulose membranes and 150 kDa MWCO polyethersulfone membranes, respectively. Glycine was the most dominant amino acid in both α1-subunit and α2-subunit. However, the tyrosine content was higher in α2-subunit than in α1-subunit, resulting in strong absorption near 280 nm observed in the UV absorption spectrum. Based on the DSC analysis, it was found that the glass transition temperatures of gelatin, α1-subunit and α2-subunit were 136.48 °C, 126.77 °C and 119.43 °C, respectively. Moreover, the reduced viscosity and denaturation temperature of α1-subunit were higher than those of α2-subunit, and the reduced viscosity reached the highest when α-subunits were mixed with α1/α2 ratio of approximately 2, suggesting that α1-subunit plays a more important role in the thermostability of gelatin than α2-subunit. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Fabrication and characterization of LATP/PAN composite fiber-based lithium-ion battery separators

    Energy Technology Data Exchange (ETDEWEB)

    Liang Yinzheng [Department of Textile Materials Science and Product Design, College of Textile, Donghua University, Shanghai 201620 (China); Fiber and Polymer Science Program, Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC 27695-8301 (United States); Lin Zhan [Fiber and Polymer Science Program, Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC 27695-8301 (United States); Qiu Yiping [Department of Textile Materials Science and Product Design, College of Textile, Donghua University, Shanghai 201620 (China); Zhang Xiangwu, E-mail: xiangwu_zhang@ncsu.edu [Fiber and Polymer Science Program, Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC 27695-8301 (United States)

    2011-07-15

    Lithium aluminum titanium phosphate (LATP)/polyacrylonitrile (PAN) composite fiber-based membranes were prepared by electrospinning dispersions of LATP particles in PAN solutions. The electrolyte uptakes of the electrospun LATP/PAN composite fiber-based membranes were measured and the results showed that the electrolyte uptake increased as the LATP content increased. The lithium ion conductivity, the electrochemical oxidation limit and the interface resistance of liquid electrolyte-soaked electrospun LATP/PAN composite fiber-based membranes were also measured and it was found that as the LATP content increased, the electrospun LATP/PAN composite fiber-based membranes had higher lithium ion conductivity, better electrochemical stability, and lower interfacial resistance with lithium electrode. Additionally, lithium//1 M LiPF{sub 6}/EC/EMC//lithium iron phosphate cells using LATP/PAN composite fiber-based membranes as the separator demonstrated high charge/discharge capacity and good cycle performance.

  16. Study on Separation of Structural Isomer with Magneto-Archimedes method

    Science.gov (United States)

    Kobayashi, T.; Mori, T.; Akiyama, Y.; Mishima, F.; Nishijima, S.

    2017-09-01

    Organic compounds are refined by separating their structural isomers, however each separation method has some problems. For example, distillation consumes large energy. In order to solve these problems, new separation method is needed. Considering organic compounds are diamagnetic, we focused on magneto-Archimedes method. With this method, particle mixture dispersed in a paramagnetic medium can be separated in a magnetic field due to the difference of the density and magnetic susceptibility of the particles. In this study, we succeeded in separating isomers of phthalic acid as an example of structural isomer using MnCl2 solution as the paramagnetic medium. In order to use magneto-Archimedes method for separating materials for food or medicine, we proposed harmless medium using oxygen and fluorocarbon instead of MnCl2 aqueous solution. As a result, the possibility of separating every structural isomer was shown.

  17. Characterization of Thermally Cross-Linkable Hollow Fiber Membranes for Natural Gas Separation

    KAUST Repository

    Chen, Chien-Chiang

    2013-01-23

    The performance of thermally cross-linkable hollow fiber membranes for CO2/CH4 separation and the membrane stability against CO2 plasticization was investigated. The fiber membranes were thermally cross-linked at various conditions. Cross-linking temperature was found to have a significant effect, while shorter soak time and the presence of trace oxidizer (O2 or N2O) had a negligible effect. The cross-linked fibers were tested using high CO2 content feeds (50-70% CO2) at a variety of feed pressures (up to 1000 psia), temperatures, and permeate pressures (up to 100 psia) to evaluate membrane performance under various realistic operating conditions. The results demonstrated that cross-linking improves membrane selectivity and effectively eliminates swelling-induced hydrocarbon loss at high pressures. Excellent stability under aggressive feeds (with CO2 partial pressure up to 700 psia) suggests that cross-linked hollow fiber membranes have great potential for use in diverse aggressive applications, even beyond the CO2/CH4 example explored in this work. © 2012 American Chemical Society.

  18. Ordered macroporous quercetin molecularly imprinted polymers: Preparation, characterization, and separation performance.

    Science.gov (United States)

    Feng, Yonggang; Liu, Qin; Ye, Lifang; Wu, Quanzhou; He, Jianfeng

    2017-02-01

    Ordered macroporous molecularly imprinted polymers were prepared by a combination of the colloidal crystal templating method and the molecular imprinting technique by using SiO2 colloidal crystal as the macroporogen, quercetin as the imprinting template, acrylamide as the functional monomer, ethylene glycol dimethacrylate as the cross-linker and tetrahydrofuran as the solvent. Scanning electron microscopy and Brunauer-Emmett-Teller measurements show that the ordered macroporous molecularly imprinted polymers have a more regular macroporous structure, a narrower pore distribution and a greater porosity compared with the traditional bulk molecularly imprinted polymers. The kinetic and isothermal adsorption behaviors of the polymers were investigated. The results indicate that the ordered macroporous molecularly imprinted polymers have a faster intraparticle mass transfer process and a higher adsorption capacity than the traditional bulk molecularly imprinted polymers. The ordered macroporous molecularly imprinted polymers were further employed as a sorbent for a solid-phase extraction. The results show that the ordered macroporous molecularly imprinted polymers can effectively separate quercetin from the Gingko hydrolysate. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Fabrication and characterization of porous poly(L-lactide) scaffolds using solid-liquid phase separation.

    Science.gov (United States)

    Goh, Yan Qi; Ooi, Chui Ping

    2008-06-01

    Freeze-extraction, which involves phase separation principle, gave highly porous scaffolds without the time and energy consuming freeze-drying process. The presented method eliminates the problem of formation of surface skin observed in freeze-drying methods. The effects of different freezing temperature (-80 and -24 degrees C), medium (dry ice/ethanol bath and freezer) and polymer concentrations (1, 3, and 5 wt.%) on the scaffold properties were investigated in connection with the porous morphology and physicomechanical characteristics of the final scaffolds. The FESEM micrographs showed porous PLLA scaffolds with ladder-like architecture. The size of the longitudinal pores was in the range of 20-40 microm and the scaffolds had high porosity values ranging from 90% to 98%. Variation in porosity, mechanical resistance, and degree of regularity in the spatial organization of pores were observed when polymer concentration was changed. More open scaffold architecture with enhanced pore interconnectivity was achieved when a dry ice/ethanol bath of -80 degrees C was used. Polymer concentration played an important role in fabricating highly porous scaffolds, with ladder-like architecture only appearing at polymer concentrations of above 3 wt.%. With the freeze-extraction method used here, highly porous and interconnected poly(L-lactide) scaffolds were successfully fabricated, holding great potential for tissue engineering applications.

  20. Green synthesis, characterization and catalytic activity of silver nanoparticles using Cassia auriculata flower extract separated fraction

    Science.gov (United States)

    Muthu, Karuppiah; Priya, Sethuraman

    2017-05-01

    Cassia auriculata L., the flower aqueous extract was fractionated by separating funnel using n-hexane (A1), chloroform (A2), ethyl acetate (A3) and triple distilled water (A4). The A4 fraction was concentrated and determined the presence of preliminary phytochemicals such as tannins, flavonoids, glycosides, carbohydrates and polyphenolic compounds. These phytochemical compounds acted as reducing as well as a stabilizing agent in the green synthesis of Ag NPs from aqueous silver ions. Initially, the colour change and UV-vis absorbance surface Plasmon resonance strong, wide band located at 435 nm has confirmed the synthesis of Ag NPs. The X-ray diffraction (XRD) pattern of Ag NPs shows a face-centered cubic crystal structure. The observed values were calculated by Debye-Scherrer equation to theoretical confirms the particle size of 18 nm. The surface morphology of Ag NPs was viewed by HRTEM, the particles are spherical and triangle shapes with sizes from 10 to 35 nm. Further, the Ag NPs was effective catalytic activity in the reduction of highly environmental polluted organic compounds of 4-nitrophenol and methyl orange. The green synthesis of Ag NPs seems to eco-friendly, cost-effective, conventional one spot synthesis and greater performance of catalytic degradation of environmentally polluted organic dyes.

  1. CHARACTERIZATION OF MODIFIED MONOSODIUM TITANATE - AN IMPROVED SORBENT FOR STRONTIUM AND ACTINIDE SEPARATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.; Taylor-Pashow, K.; Missimer, D.

    2010-12-21

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove {sup 134,137}Cs, {sup 90}Sr, and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. An inorganic sorbent, monosodium titanate (MST), is currently used to remove {sup 90}Sr and alpha-emitting radionuclides, while a caustic-side solvent extraction process is used for removing {sup 134,137}Cs. A new peroxotitanate material, modified MST, or mMST, has recently been developed and has shown increased removal kinetics and capacity for {sup 90}Sr and alpha-emitting radionuclides compared to the current baseline material, MST. This paper describes recent results focused on further characterization of this material.

  2. Density Functional Reactivity Theory Characterizes Charge Separation Propensity in Proton-Coupled Electron Transfer Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Shubin [Univ. of North Carolina, Chapel Hill, NC (United States); Ess, Daniel H. [Brigham Young Univ., Provo, UT (United States); Univ. of North Carolina, Chapel Hill, NC (United States); Schauer, Cynthia [Univ. of North Carolina, Chapel Hill, NC (United States)

    2011-04-20

    Proton-coupled electron transfer (PCET) reactions occur in many biological and artificial solar energy conversion processes. In these reactions the electron is often transferred to a site distant to the proton acceptor site. In this work, we employ the dual descriptor and the electrophilic Fukui function from density functional reactivity theory (DFRT) to characterize the propensity for an electron to be transferred to a site other than the proton acceptor site. The electrophilic regions of hydrogen bond or van der Waal reactant complexes were examined using these DFRT descriptors to determine the region of space to which the electron is most likely to be transferred. This analysis shows that in PCET reactions the electrophilic region of the reactant complex does not include the proton acceptor site.

  3. Characterizing quantum channels with non-separable states of classical light

    Science.gov (United States)

    Ndagano, Bienvenu; Perez-Garcia, Benjamin; Roux, Filippus S.; McLaren, Melanie; Rosales-Guzman, Carmelo; Zhang, Yingwen; Mouane, Othmane; Hernandez-Aranda, Raul I.; Konrad, Thomas; Forbes, Andrew

    2017-04-01

    High-dimensional entanglement with spatial modes of light promises increased security and information capacity over quantum channels. Unfortunately, entanglement decays due to perturbations, corrupting quantum links that cannot be repaired without performing quantum tomography on the channel. Paradoxically, the channel tomography itself is not possible without a working link. Here we overcome this problem with a robust approach to characterize quantum channels by means of classical light. Using free-space communication in a turbulent atmosphere as an example, we show that the state evolution of classically entangled degrees of freedom is equivalent to that of quantum entangled photons, thus providing new physical insights into the notion of classical entanglement. The analysis of quantum channels by means of classical light in real time unravels stochastic dynamics in terms of pure state trajectories, and thus enables precise quantum error correction in short- and long-haul optical communication, in both free space and fibre.

  4. Hyperbranched polyglycerol-grafted titanium oxide nanoparticles: synthesis, derivatization, characterization, size separation, and toxicology

    Science.gov (United States)

    Qin, Hongmei; Maruyama, Kyouhei; Amano, Tsukuru; Murakami, Takashi; Komatsu, Naoki

    2016-10-01

    We have been developing surface functionalization of various nanoparticles including nanodiamond and iron oxide nanoparticles in view of biomedical applications. In this context, TiO2 nanoparticles (TiO2 NP) are functionalized with polyglycerol (PG) to provide water-dispersible TiO2-PG, which is further derivatized through multi-step organic transformations. The resulting TiO2-PG and its derivatives are fully characterized by various analyses including solution-phase 1H and 13C NMR. TiO2-PG was size-tuned with centrifugation by changing the acceleration and duration. At last, no cytotoxicity of TiO2 NP, TiO2-PG, and TiO2-PG functionalized with RGD peptide was observed under dark conditions.

  5. Systematic Study of Separators in Air-Breathing Flat-Plate Microbial Fuel Cells—Part 2: Numerical Modeling

    Directory of Open Access Journals (Sweden)

    Sona Kazemi

    2016-01-01

    Full Text Available The separator plays a key role on the performance of passive air-breathing flat-plate MFCs (FPMFC as it isolates the anaerobic anode from the air-breathing cathode. The goal of the present work was to study the separator characteristics and its effect on the performance of passive air-breathing FPMFCs. This was performed partially through characterization of structure, properties, and performance correlations of eight separators presented in Part 1. Current work (Part 2 presents a numerical model developed based on the mixed potential theory to investigate the sensitivity of the electrode potentials and the power output to the separator characteristics. According to this numerical model, the decreased peak power results from an increase in the mass transfer coefficients of oxygen and ethanol, but mainly increasing mixed potentials at the anode by oxygen crossover. The model also indicates that the peak power is affected by the proton transport number of the separator, which affects the cathode pH. Anode pH, on the other hand, remains constant due to application of phosphate buffer solution as the electrolyte. Also according to this model, the peak power is not sensitive to the resistivity of the separator because of the overshadowing effect of the oxygen crossover.

  6. Preparation and Characterization of HDPE/EVA Flat Sheet Membranes by Thermally Induced Phase Separation Method

    Directory of Open Access Journals (Sweden)

    Zahra Shoeyb

    2015-06-01

    Full Text Available The adjustment of material composition in fabrication of modified polymeric membrane has been considered the most efficient and easiest method. For this purpose blended membranes of high density polyethylene (HDPE–ethylene vinyl acetate (EVA were prepared by thermally induced phase separation method. The impact of EVA in the presence of diluent on the crystalization temperature was assessed using differential scanning calorimetry (DSC. The obtained results showed that EVA has no significant effect on the crystalization temperature of HDPE. The absorption frequencies at 1248 and 1749 cm-1, respectively, due to C-O and C=O streching vibrations of EVA functional groups, confirmed the existence of EVA in HDPE membrane. The pure water permeability of HDPE/EVA blend was measured and compared with that of neat HDPE membrane. The results showed that an EVA content up to 2.5 wt% raised water permeability considerably and the leafy structure of the membranes contracted and the pure water permeation dropped with higher EVA content. The results of porosity measurement and scanning electronic microscopic (SEM analysis also confirmed these findings. Contact angel measurements and atomic force microscopy (AFM examinations and static absorption of collagen protein on the membrane surfaces revealed that EVA content up to 5 wt% lowered the hydrophobicity of the membrane. By EVA content above 10 wt%, due to the structural alteration on the membrane surface, the contact angel and the collagen absorption on the surface of membrane increased. The measurement of tensile strength showed that with increasing EVA content the mechanical properties of the membranes improved due to interactions of polar groups in EVA.

  7. A study of phase separation in ternary alloys

    Indian Academy of Sciences (India)

    Keywords. Ternary systems; Cahn–Hilliard equations; spinodal decomposition. Abstract. We have studied the evolution of microstructure when a disordered ternary alloy is quenched into a ternary miscibility gap. We have used computer simulations based on multicomponent Cahn–Hilliard (CH) equations for A and B, ...

  8. Development and characterization of polyethersulfone/TiO2 mixed matrix membranes for CO2/CH4 separation

    Science.gov (United States)

    Galaleldin, S.; Mannan, H. A.; Mukhtar, H.

    2017-12-01

    In this study, mixed matrix membranes comprised of polyethersulfone as the bulk polymer phase and titanium dioxide (TiO2) nanoparticles as the inorganic discontinuous phase were prepared for CO2/CH4 separation. Membranes were synthesized at filler loading of 0, 5, 10 and 15 wt % via dry phase inversion method. Morphology, chemical bonding and thermal characteristics of membranes were scrutinized utilizing different techniques, namely: Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform InfraRed (FTIR) spectra and Thermogravimetric analysis (TGA) respectively. Membranes gas separation performance was evaluated for CO2 and CH4 gases at 4 bar feed pressure. The highest separation performance was achieved by mixed matrix membrane (MMM) at 5 % loading of TiO2.

  9. Characterization of steel grit recovered from ornamental rocks waste by magnetic separation; Caracterizacao da granalha de aco recuperada do residuo de rochas ornamentais por separacao magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Junca, E.; Telles, V.B.; Rodrigues, G.F.; Oliveira, J.R. de; Tenorio, J.A.S., E-mail: eduardojunca@gmail.co [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia Metalurgica e de Materiais; Instituto Federal de Ciencia e Tecnologia do Espirito Santo (IFES), Vitoria, ES (Brazil)

    2010-07-01

    The aim of this work is characterization of steel grit recovered from ornamental rock waste by magnetic separation. The magnetic separation was realized in three steps: first, using a high intensity wet magnetic separator, which used only the remaining magnetic field of equipment. In the second step, the magnetic material obtained in the first phase was subjected to a new manual magnetic separation using rare earth magnets. In a third step, magnetic material obtained with rare earth magnets was subjected to manual magnetic separation using ferrite magnets. After the magnetic separation, the material was sent to characterization which was obtained by chemical analysis, scanning electron microscopy, X-ray diffraction and size analysis. The size analysis showed that the concentrate range from 0,5 to 563,67 {mu}m with 4 wt.% over 100 {mu}m and content metallic iron of 93 wt%. (author)

  10. Residents’ Household Solid Waste (HSW Source Separation Activity: A Case Study of Suzhou, China

    Directory of Open Access Journals (Sweden)

    Hua Zhang

    2014-09-01

    Full Text Available Though the Suzhou government has provided household solid waste (HSW source separation since 2000, the program remains largely ineffective. Between January and March 2014, the authors conducted an intercept survey in five different community groups in Suzhou, and 505 valid surveys were completed. Based on the survey, the authors used an ordered probit regression to study residents’ HSW source separation activities for both Suzhou and for the five community groups. Results showed that 43% of the respondents in Suzhou thought they knew how to source separate HSW, and 29% of them have source separated HSW accurately. The results also found that the current HSW source separation pilot program in Suzhou is valid, as HSW source separation facilities and residents’ separation behavior both became better and better along with the program implementation. The main determinants of residents’ HSW source separation behavior are residents’ age, HSW source separation facilities and government preferential policies. The accessibility to waste management service is particularly important. Attitudes and willingness do not have significant impacts on residents’ HSW source separation behavior.

  11. Separation and characterization of two chemically distinct lipopolysaccharides in two Pectinatus species.

    Science.gov (United States)

    Helander, I M; Hurme, R; Haikara, A; Moran, A P

    1992-05-01

    Lipopolysaccharides (LPS) from the type strains of the anaerobic beer spoilage bacteria Pectinatus cerevisiiphilus and P. frisingensis were extracted with the 5:5:8 volume ratio modification of the phenolchloroform-petroleum ether method (H. Brade and C. Galanos, Eur. J. Biochem. 122:233-237, 1982). Sequential precipitations of LPS with water and acetone from the phenol phase yielded LPS which differed in that water-precipitable material (LPS-H2O; 0.1 to 0.4% of the dry weight of the cells) was rough-type LPS, whereas acetone-precipitable material (LPS-Ac; 4.6 to 5.8% of the dry weight) contained both rough-type LPS and high-molecular-weight material resembling smooth LPS. The LPS were chemically characterized, and they contained D-glucosamine, 4-amino-4-deoxy-L-arabinose, 3-deoxy-D-manno-2-octulosonic acid, D-fucose, D-galactose, D-glucose, D-mannose, and phosphate. D-Fucose was present mostly in LPS-Ac, suggesting that it is a constituent of the O antigen. The major fatty acids were ester- and amide-linked (R)-3-hydroxytridecanoic and ester-linked undecanoic acids, with minor amounts of ester-linked tridecanoic and (R)-3-hydroxyundecanoic acids. The chemical compositions of LPS-H2O and LPS-Ac suggested that they differ not only in their smooth or rough nature but also in the structure of their core regions. This may explain their different precipitabilities from the extraction mixture. The extraction method was also shown to be applicable to the isolation of smooth-type LPS from Salmonella enterica serovar Typhimurium. Extraction of two Typhimurium strains carrying chemically different O antigens resulted in high yields (8% of the dry weight) of LPS. Strain SH2183, which contains the relatively hydrophobic O-4,5,12 antigen yielded almost exclusively LPS-Ac, whereas the LPS of strain SH5770, which has a hydrophilic O-6,7 antigen, was exclusively LPS-H2O. No fractionation to smooth and rough LPS occurred with the Typhimurium strains.

  12. A study on fiy ash: ballistic separation of a fly ash

    Directory of Open Access Journals (Sweden)

    Peris Mora, Eduardo

    1991-09-01

    Full Text Available The object of this study is the characterization of several sized fractions from a "spanish fly ash" originating in the thermoelectric power plant in Andorra (Teruel. Physical (size distributions, densities chemical (chemical composition and mineralogical characteristics (X-ray diffractograms and infrared spectra for those sized fractions have been analyzed. Initial fly ash was ballistically separated (horizontal draft into four fractions using an aerodynamic tunnel with horizontal air current The separation effectivity was adapted for our later studies. The results obtained were interesting: in the first case, the simplicity of the separation method, by this way we will be able to use it for further studies on sized fractions. On the other hand, differences on granulometric distributions and vitreous nature will allow us to study the effect of several fractions on mechanic properties of concrete with them.

    El objeto de este estudio es la caracterización de las diferentes fracciones de distintas granulometrías y tamaños obtenidas de una ceniza volante española producida en la central termoeléctrica de Andorra (Teruel. Se han estudiado las propiedades físicas (distribución granulométrica, densidad químicas (composición química y mineralógicas (difracción de rayos X y espectroscopia infrarroja de dichas fracciones. La técnica de separación aplicada es la "balística" (tiro horizontal, de la que se obtienen cuatro fracciones. Se usó un túnel aerodinámico con corriente horizontal de aire. La efectividad de la separación conseguida fue satisfactoria para nuestros objetivos. Los resultados obtenidos son interesantes desde dos puntos de vista: Por una parte, la simplicidad del método permite aplicarlo para posteriores estudios en cantidades importantes. Por otra parte, las diferencias en las distribuciones granulométricas y su naturaleza vitrea nos permitirá diseñar un estudio posterior acerca de la influencia

  13. Characterization of Metal-Doped Methylated Microporous Silica for Molecular Separations

    DEFF Research Database (Denmark)

    El-Feky, Hany Hassan; Briceno, Kelly; Szalata, Kamila

    2015-01-01

    Novel silica xerogels are prepared and developed by sol-gel method in the present study. The preparation involves cobalt-doping within the organic templated silica matrices, where methyltriethoxysilane (MTES), which contains methyl groups as a covalently bonded organic template is used. The synth...

  14. Gold nanorod separation and characterization by asymmetric-flow field flow fractionation with UV-Vis detection.

    Science.gov (United States)

    Gigault, Julien; Cho, Tae Joon; MacCuspie, Robert I; Hackley, Vincent A

    2013-02-01

    The application of asymmetric-flow field flow fractionation (A4F) for low aspect ratio gold nanorod (GNR) fractionation and characterization was comprehensively investigated. We report on two novel aspects of this application. The first addresses the analytical challenge involved in the fractionation of positively charged nanoparticles by A4F, due to the interaction that exists between the negatively charged native membrane and the analyte. We show that the mobile phase composition is a critical parameter for controlling fractionation and mitigating the membrane-analyte interaction. A mixture of ammonium nitrate and cetyl trimethyl ammonium bromide at different molar ratios enables separation of GNRs with high recovery. The second aspect is the demonstration of shape-based separation of GNRs in A4F normal mode elution (i.e., Brownian mode). We show that the elution of GNRs is due both to aspect ratio and a steric-entropic contribution for GNRs with the same diameter. This latter effect can be explained by their orientation vector inside the A4F channel. Our experimental results demonstrate the relevance of the theory described by Beckett and Giddings for non-spherical fractionation (Beckett and Giddings, J Colloid and Interface Sci 186(1):53-59, 1997). However, it is shown that this theory has its limit in the case of complex GNR mixtures, and that shape (i.e., aspect ratio) is the principal material parameter controlling elution of GNRs in A4F; the apparent translational diffusion coefficient of GNRs increases with aspect ratio. Finally, the performance of the methodology developed in this work is evaluated by the fractionation and characterization of individual components from a mixture of GNR aspect ratios.

  15. Quantitative characterization of magnetic separators: Comparison of systems with and without integrated microfluidic mixers

    DEFF Research Database (Denmark)

    Lund-Olesen, Torsten; Bruus, Henrik; Hansen, Mikkel Fougt

    2006-01-01

    micrographs, and simulations and analytical models of bead trajectories, capture efficiencies, and capture distributions. We show that the efficiencies of both systems compare favorably to those in the literature. For the studied geometries, the mixer is demonstrated to increase the bead capture......-and-release efficiency for a fixed flow rate by up to a factor of two. Moreover, high capture efficiencies can be achieved in the system with mixer at up to ten times higher flow rates than in the system without mixer....

  16. Characterization of Metal-Doped Methylated Microporous Silica for Molecular Separations

    DEFF Research Database (Denmark)

    El-Feky, Hany Hassan; Briceno, Kelly; Szalata, Kamila

    2015-01-01

    Novel silica xerogels are prepared and developed by sol-gel method in the present study. The preparation involves cobalt-doping within the organic templated silica matrices, where methyltriethoxysilane (MTES), which contains methyl groups as a covalently bonded organic template is used....... The synthesis and surface properties of cobalt-doped methylated microporous silica xerogels with different MTES and cobalt content are revealed by surface and microstructural techniques, such as TGA, FTIR, X-ray and N2 adsorption measurements. The doping process enhances the thermal stability of the silica...... xerogels up to ~ 560 °C in oxidizing atmosphere. Besides, this process has no significant effect on the incorporation of the organic template within the silica matrix. As result of the promoted densification of the xerogels either by increasing MTES content and heat treatment, there is structural change...

  17. Synthesis and structural characterization of separate graphene oxide and reduced graphene oxide nanosheets

    Science.gov (United States)

    Aslam, M.; Kalyar, M. A.; Raza, Z. A.

    2016-10-01

    Graphene, being a unique carbon allotrope with a structure that is one atom thick, is known as a mysterious material in the current era due to its strange nature. It has attained global attention due to its amazing mechanical, electrical, thermal and optical properties. Recent progress has revealed that materials built with graphene can have a limitless impact on nanocomposites, electronic, optoelectronic and energy storage devices as well as chemical sensors. In the present study, graphite flakes were chemically oxidized in graphite oxide via the modified Hummers’ method, i.e. without adding sodium nitrate. The graphite oxide was exfoliated in distilled water by using an ultrasonic bath to fabricate graphene oxide nanosheets. The graphene was acquired through an inexpensive and large-scale production route to eliminate functional groups containing oxygen by using hydrazine monohydrate as a reducing agent. The reduced graphene oxide obtained through this route contained residual oxygen-functional groups which can act as active sites for gas molecular interaction and be used in a variety of applications like gas sensing. The prepared samples were analyzed using the dynamic light scattering technique, UV-visible spectroscopy, Fourier transform infrared spectroscopy, x-ray diffraction, scanning electron microscopy and atomic force microscopy.

  18. Turbine blade boundary layer separation suppression via synthetic jet: An experimental and numerical study

    Science.gov (United States)

    Bernardini, C.; Carnevale, M.; Manna, M.; Martelli, F.; Simoni, D.; Zunino, P.

    2012-10-01

    The present paper focuses on the analysis of a synthetic jet device (with a zero net massflow rate) on a separated boundary layer. Separation has been obtained on a flat plate installed within a converging-diverging test section specifically designed to attain a local velocity distribution typical of a high-lift LPT blade. Both experimental and numerical investigations have been carried out. Unsteady RANS results have been compared with experiments in terms of time-averaged velocity and turbulence intensity distributions. Two different Reynolds number cases have been investigated, namely Re = 200, 000 and Re = 70, 000, which characterize low-pressure turbine operating conditions during take-off/landing and cruise. A range of synthetic jet aerodynamic parameters (Strouhal number and blowing ratio) has been tested in order to analyze the features of control — separated boundary layer interaction for the aforementioned Reynolds numbers.

  19. Separating Morphologically Similar Pollen Types Using Basic Shape Features from Digital Images: A Preliminary Study

    Directory of Open Access Journals (Sweden)

    Katherine A. Holt

    2014-08-01

    Full Text Available Premise of the study: One of the many advantages offered by automated palynology systems is the ability to vastly increase the number of observations made on a particular sample or samples. This is of particular benefit when attempting to fully quantify the degree of variation within or between closely related pollen types. Methods: An automated palynology system (Classifynder has been used to further investigate the variation in pollen morphology between two New Zealand species of Myrtaceae (Leptospermum scoparium and Kunzea ericoides that are of significance in the New Zealand honey industry. Seven geometric features extracted from automatically gathered digital images were used to characterize the range of shape and size of the two taxa, and to examine the extent of previously reported overlap in these variables. Results: Our results indicate a degree of overlap in all cases. The narrowest overlap was in measurements of maximum Feret diameter (MFD in grains oriented in polar view. Multivariate statistical analysis using all seven factors provided the most robust discrimination between the two types. Discussion: Further work is required before this approach could be routinely applied to separating the two pollen types used in this study, most notably the development of comprehensive reference distributions for the types in question.

  20. PEGylated gold nanorod separation based on aspect ratio: characterization by asymmetric-flow field flow fractionation with UV-Vis detection.

    Science.gov (United States)

    Nguyen, Thao M; Gigault, Julien; Hackley, Vincent A

    2014-02-01

    The development of highly efficient asymmetric-flow field flow fractionation (A4F) methodology for biocompatible PEGylated gold nanorods (GNR) without the need for surfactants in the mobile phase is presented. We report on the potential of A4F for rapid separation by evaluating the efficiency of functionalized surface coverage in terms of fractionation, retention time (t R ) shifts, and population analysis. By optimizing the fractionation conditions, we observed that the mechanism of separation for PEGylated GNRs by A4F is the same as that for CTAB stabilized GNRs (i.e., according to their AR) which confirms that the elution mechanism is not dependent on the surface charge of the analytes and/or the membrane. In addition, we demonstrated that A4F can distinguish different surface coverage populations of PEGylated GNRs. The data established that a change in Mw of the functional group and/or surface orientation can be detected and fractionated by A4F. The findings in this study provide the foundation for a complete separation and physicochemical analysis of GNRs and their surface coatings, which can provide accurate and reproducible characterization critical to advancing biomedical research.

  1. Identification and functional characterization of AclB, a novel cell-separating enzyme from Lactobacillus casei.

    Science.gov (United States)

    Xu, Yi; Wang, Ting; Kong, Jian; Wang, Hui-Li

    2015-06-16

    Autolysis of nonstarter lactic acid bacteria (NSLAB) was favorable for the development of flavor compounds during cheese manufacture. Among these bacteria, Lb. casei was regarded as the most important microbiota involved in cheese processes. In this study, a novel autolysin named AclB was identified in the genome of Lb. casei BL23 and its modular structure was predicted through bioinformatic approaches. Subsequently, its transcription profile in the exponential phase, hydrolytic activities against cell walls, enzymatic properties under different conditions, physiological function via gene inactivation and upregulation assays, as well as potential applications to NSLAB's autolysis were fully investigated. According to the results, AclB was recognized as a species-specific cell-separating enzyme, responsible for cell separation after cell division in Lb. casei BL23. The purified AclB showed considerable hydrolyzing activities towards cell walls, indicating its enzymatic nature as peptidoglycan hydrolase, or autolysin. The highest activity of AclB was determined at pH5.0 and 37°C, and the expression vector constructed based on AclB was shown to facilitate the controlled lysis of Lb. casei BL23 hosts. In summary, this study provided insight into the enzymatic properties of a novel autolysin involved in cell separation of Lb. casei BL23, which is promising to accelerate cheese ripening and improve cheese quality. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Parameter study on numerical simulation of corner separation in LMFA-NACA65 linear compressor cascade

    Directory of Open Access Journals (Sweden)

    Feng Gao

    2017-02-01

    Full Text Available Large-eddy simulation (LES is compared with experiment and Reynolds-averaged Navier-Stokes (RANS, and LES is shown to be superior to RANS in reproducing corner separation in the LMFA-NACA65 linear compressor cascade, in terms of surface limiting streamlines, blade pressure coefficient, total pressure losses and blade suction side boundary layer profiles. However, LES is too expensive to conduct an influencing parameter study of the corner separation. RANS approach, despite over-predicting the corner separation, gives reasonable descriptions of the corner separated flow, and is thus selected to conduct a parametric study in this paper. Two kinds of influencing parameters on corner separation, numerical and physical parameters, are analyzed and discussed: second order spatial scheme is necessary for a RANS simulation; incidence angle and inflow boundary layer thickness are found to show the most significant influences on the corner separation among the parameters studied; unsteady RANS with the imposed inflow unsteadiness (inflow angle varying sinusoidally with fluctuating amplitude of 0.92° does not show any non-linear effect on the corner separation.

  3. Preparation and Characterization of Hydrophilically Modified PVDF Membranes by a Novel Nonsolvent Thermally Induced Phase Separation Method

    Science.gov (United States)

    Hu, Ningen; Xiao, Tonghu; Cai, Xinhai; Ding, Lining; Fu, Yuhua; Yang, Xing

    2016-01-01

    In this study, a nonsolvent thermally-induced phase separation (NTIPS) method was first proposed to fabricate hydrophilically-modified poly(vinylidene fluoride) (PVDF) membranes to overcome the drawbacks of conventional thermally-induced phase separation (TIPS) and nonsolvent-induced phase separation (NIPS) methods. Hydrophilically-modified PVDF membranes were successfully prepared by blending in hydrophilic polymer polyvinyl alcohol (PVA) at 140 °C. A series of PVDF/PVA blend membranes was prepared at different total polymer concentrations and blend ratios. The morphological analysis via SEM indicated that the formation mechanism of these hydrophilically-modified membranes was a combined NIPS and TIPS process. As the total polymer concentration increased, the tensile strength of the membranes increased; meanwhile, the membrane pore size, porosity and water flux decreased. With the PVDF/PVA blend ratio increased from 10:0 to 8:2, the membrane pore size and water flux increased. The dynamic water contact angle of these membranes showed that the hydrophilic properties of PVDF/PVA blend membranes were prominently improved. The higher hydrophilicity of the membranes resulted in reduced membrane resistance and, hence, higher permeability. The total resistance Rt of the modified PVDF membranes decreased significantly as the hydrophilicity increased. The irreversible fouling related to pore blocking and adsorption fouling onto the membrane surface was minimal, indicating good antifouling properties. PMID:27869711

  4. Performance Characterization of Gas-Solid Cyclone for Separation of Particle from Syngas Produced from Food Waste Gasifier Plant

    Directory of Open Access Journals (Sweden)

    Osezua O. Ibhadode

    2017-06-01

    Full Text Available A biofuel from any biodegradable formation process such as a food waste bio-digester plant is a mixture of several gases such as methane (CH4, carbon dioxide (CO2, hydrogen sulfide (H2S, ammonia (NH3 and impurities like water and dust particles. The results are reported of a parametric study of the process of separation of methane, which is the most important gas in the mixture and usable as a biofuel, from particles and H2S. A cyclone, which is a conventional, economic and simple device for gas-solid separation, is considered based on the modification of three Texas A&M cyclone designs (1D2D, 2D2D and 1D3D by the inclusion of an air inlet tube. A parametric sizing is performed of the cyclone for biogas purification, accounting for the separation of hydrogen sulfide (H2S and dust particles from the biofuel. The stochiometric oxidation of H2S to form elemental sulphur is considered a useful cyclone design criterion. The proposed design includes geometric parameters and several criteria for quantifying the performance of cyclone separators such as the Lapple Model for minimum particle diameter collected, collection efficiency and pressure drop. For biogas volumetric flow rates between 0 and 1 m/s and inlet flow velocities of 12 m/s, 15 m/s and 18 m/s for the 1D2D, 2D2D and 1D3D cyclones, respectively, it is observed that the 2D2D configuration is most economic in terms of sizing (total height and diameter of cyclone. The 1D2D configuration experiences the lowest pressure drop. A design algorithm coupled with a user-friendly graphics interface is developed on the MATLAB platform, providing a tool for sizing and designing suitable cyclones.

  5. Separating morphologically similar pollen types using basic shape features from digital images: A preliminary study(1.).

    Science.gov (United States)

    Holt, Katherine A; Bebbington, Mark S

    2014-08-01

    One of the many advantages offered by automated palynology systems is the ability to vastly increase the number of observations made on a particular sample or samples. This is of particular benefit when attempting to fully quantify the degree of variation within or between closely related pollen types. • An automated palynology system (Classifynder) has been used to further investigate the variation in pollen morphology between two New Zealand species of Myrtaceae (Leptospermum scoparium and Kunzea ericoides) that are of significance in the New Zealand honey industry. Seven geometric features extracted from automatically gathered digital images were used to characterize the range of shape and size of the two taxa, and to examine the extent of previously reported overlap in these variables. • Our results indicate a degree of overlap in all cases. The narrowest overlap was in measurements of maximum Feret diameter (MFD) in grains oriented in polar view. Multivariate statistical analysis using all seven factors provided the most robust discrimination between the two types. • Further work is required before this approach could be routinely applied to separating the two pollen types used in this study, most notably the development of comprehensive reference distributions for the types in question.

  6. Synthesis and characterization of magnetic hexacyanoferrate (II) polymeric nanocomposite for separation of cesium from radioactive waste solutions.

    Science.gov (United States)

    Sheha, Reda R

    2012-12-15

    Nanocrystalline potassium zinc hexacyanoferrate loaded on nanoscale magnetite substrate was successfully synthesized for significantly enhanced removal of cesium from low-level radioactive wastes. A description was given for preparation and properties of these precursors. The physicochemical properties of these nanocomposites were determined using different techniques including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Data clarified that supporting potassium zinc hexacyanoferrates on iron ferrite nanoparticles increased their thermal stability. Further, Fourier transform infrared spectra confirmed that the nanocomposites were well coordinated and incorporated in the polymer matrix. The average particle sizes, of these nanoparticles, determined by SEM had a good agreement with XRD results. Based on characterization data, the prepared zinc hexacyanoferrates were proposed to have a zeolitic rhombohedral structure with cavities can host alkali metal ions and water molecules. The magnetic analysis showed a super-paramagnetic behavior. Batch technique was applied to evaluate the influences of initial pH value, contact time, and competing cations on the efficiency of cesium removal. The sorption process was fast initially, and maximum separation was attained within 2h of contact. Cesium exchange was independent from pH value and deviate from ideal exchange phenomena. In neutral solutions, Cs(+) was retained through exchange with K(+); however, in acidic solution, phase transformation was proposed. Sorption capacity of these materials attained values amounted 1965 mg g(-1). The synthesized nanocomposites exhibited different affinities toward Cs(I), Co(II), and Eu(III) elements and showed a good ability to separate them from each other. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Characterization of blood components separated from donated whole blood after an overnight holding at room temperature with the buffy coat method.

    Science.gov (United States)

    Lu, Fa Qiang; Kang, Wei; Peng, Yu; Wang, Wei Ming

    2011-10-01

    With buffy coat (BC) processing of whole blood (WB) donations, increase in WB storage time to facilitate overnight holding before the separation of blood components would be a logistically attractive development. This study undertakes a comparative in vitro characterization of blood components prepared from WB samples that were either processed within 8 hours or stored overnight at room temperature before processing by the BC method. The WB units (400 mL) collected were either processed within 8 hours (fresh blood) or stored overnight (overnight blood) at room temperature. WB units were separated into individual-component red blood cells (RBCs), BC, and plasma. The in vitro quality of these blood components (RBCs, pooled platelet concentrates [PCs], and plasma) was analyzed during storage. Levels of 2,3-diphosphoglycerate (2,3-DPG) were found to be significantly lower immediately after processing, compared with the fresh WB samples, in RBCs that had been separated from an overnight-hold sample. However, this difference was not apparent after 14 days of storage. In pooled PCs, measurements for glucose, lactate, PO(2), PCO(2), extent of shape change, and hypotonic shock response were similar. The platelet yield in PCs prepared from an overnight-hold WB sample was significantly higher, while CD62P expression and annexin V binding were lower (p component that was most sensitive to the prolongation of production time and it only had 80% of the activity of the 8-hour FP. These data suggest that blood components (RBCs, pooled PCs, and FP) separated from WB that has been stored overnight at room temperature by the BC method are of acceptable quality. © 2011 American Association of Blood Banks.

  8. Model of Chinese Household Kitchen Waste Separation Behavior: A Case Study in Beijing City

    Directory of Open Access Journals (Sweden)

    Yalin Yuan

    2016-10-01

    Full Text Available High participation rates by the public in authority projects are key in increasing resident recycling levels. Understanding waste separation behavior is crucial to achieving sustainable waste management within such household-based schemes. To identify the driving forces behind the seldom-discussed kitchen garbage separation behavior, five psychological factors, namely, attitude, perceived behavior control, subjective norms, moral norms, and responsibility denial, are established. Our data originate from a social study of Beijing citizens conducted in July 2013 (n = 362. Through structural equation modeling, we find that moral norms are consistently the most important predictor of household kitchen waste (KW separation behavior. Subjective norms have a larger effect on such behavior than responsibility denial. Data analysis shows that perceived behavior control contributes significantly and independently to the explanation of such behavior. By contrast, attitude towards KW separation is found to be significantly negatively correlated with separation behavior. In conclusion, the model with direct and indirect effects of psychological factors explains 50.3% of the variance in household KW source separation behavior. Implications of the results for the promotion of household KW separation programs are discussed.

  9. Selective separation, detection of zotepine and mass spectral characterization of degradants by LC–MS/MS/QTOF

    Directory of Open Access Journals (Sweden)

    M.V.N. Kumar Talluri

    2014-04-01

    Full Text Available A simple, precise, accurate stability-indicating gradient reversed-phase high-performance liquid chromatographic (RP–HPLC method was developed for the quantitative determination of zotepine (ZTP in bulk and pharmaceutical dosage forms in the presence of its degradation products (DPs. The method was developed using Phenomenex C18 column (250 mm×4.6 mm i.d., 5 µm with a mobile phase containing a gradient mixture of solvents, A (0.05% trifluoroacetic acid (TFA, pH=3.0 and B (acetonitrile. The eluted compounds were monitored at 254 nm; the run time was within 20.0 min, in which ZTP and its DPs were well separated, with a resolution of >1.5. The stress testing of ZTP was carried out under acidic, alkaline, neutral hydrolysis, oxidative, photolytic and thermal stress conditions. ZTP was found to degrade significantly in acidic, photolytic, thermal and oxidative stress conditions and remain stable in basic and neutral conditions. The developed method was validated with respect to specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness as per ICH guidelines. This method was also suitable for the assay determination of ZTP in pharmaceutical dosage forms. The DPs were characterized by LC–MS/MS and their fragmentation pathways were proposed. Keywords: Zotepine, Stability-indicating RP–HPLC method, Characterization, ESI-Q-TOF-MS, Bulk drugs and formulations

  10. Study of the separation method of structural isomer using Magneto-Archimedes method

    Energy Technology Data Exchange (ETDEWEB)

    Mori, T.; Kobayadhi, T.; Mishima, F.; Akiyama, Y.; Nishijima, Shigehiro [Osaka University, Osaka (Japan)

    2016-03-15

    Organic compounds have a problem that the separation of structural isomer in the preparation process requires high energy consumption. This study proposes a new separation method of structural isomer using Magneto- Archimedes method. Firstly, the levitation height of 1, 6-DDA and 1, 10-DDA was respectively calculated by simulation of the forces acting on the particles under magnetic field, and it was indicated that they could be separated by the difference of levitation height. To confirm the phenomenon experimentally, white powders of 1, 6-DDA and 1, 10-DDA were formed into pellets, and were soaked in manganese chloride solution. Then the solution was put on the center of the cryostat of HTS bulk magnet (maximum magnetic flux density is 3T). As a result, it was confirmed that the separation of structural isomer by difference of levitation height could be possible.

  11. Investigating the Intrinsic Ethanol/Water Separation Capability of ZIF-8: An Adsorption and Diffusion Study

    KAUST Repository

    Zhang, Ke

    2013-04-11

    Intrinsic ethanol/water separation capability of ZIF-8 is characterized by a detailed study of adsorption and diffusion of ethanol and water vapor in dodecahedral crystals with principle axis dimension of 324, 15.8, and 0.4 μm. ZIF-8 exhibits extremely low water uptakes. At 35 C and a relative pressure (P/Po) of 0.95, the water uptakes for 324, 15.8, and 0.4 μm ZIF-8 are 0.184, 0.197, and 0.503 mmol/g, respectively, all of which are less than 1 wt % increase relative to original sorbent mass (0.33, 0.35, 0.91 wt %). For ethanol adsorption, ZIF-8 exhibits an S-shape isotherm with low ethanol uptakes at P/Po up to 0.08 and the cage filling phenomenon occurs at P/P o higher than 0.08. The ethanol saturation uptake in ZIF-8 is as high as 30% of the sorbent weight. Because of the existence of the hydrophilic -N-H functionality introduced by the terminating imidazolate (Im) linker and the overall hydrophobicity of the inner network, the effect of outer surface area of ZIF-8 crystals is proved to be non-negligible as ZIF-8 crystals becomes smaller despite the extremely large inner surface area and pore volume, especially for water sorption. The variation of isosteric heats of adsorption for water reveals the existence of structural defect of ZIF-8 framework. Transport diffusivity and corrected diffusivity for water and ethanol in ZIF-8 are determined within the entire P/Po range. The ethanol/water separation performance in ZIF-8 is evaluated in terms of vapor-phase sorption selectivity and permselectivity. While ZIF-8 exhibits ample ethanol/water sorption selectivity, it is not effective for ethanol extraction as a membrane material from dilute ethanol aqueous solutions due to the unfavorable diffusion selectivity and the competitive water uptakes in the adsorbed ethanol phase. © 2013 American Chemical Society.

  12. A Study on the Performance of the Saffron Separator for Different Air Flows

    Directory of Open Access Journals (Sweden)

    Abbas Moghanizadeh

    2014-10-01

    Full Text Available Saffron, the dried stigmas of Crocus sativus, is extremely appreciated for its extraordinary color, taste and aroma. At the present time, nearly all the saffron harvest and post harvest processes are carried out manually. To increase the quality and development of economic role of saffron, it is essential to go beyond the traditional method of harvest of saffron. Considering that saffron components terminal velocities are different, a separator is planned and constructed to separate stigma from other parts of saffron flower. This separator is designed on the basis of aerodynamic and physical properties of saffron flower. The purpose of this study is to analyze the performance of a saffron separator for different air flows to increase the level of automation and efficiency of post-harvest operations. The results show that the maximum stigma separation happens when the air flow speed in outlet B is 3 m/s. finally, this data will be applied to find the optimum areas of outlet B and D, as two main parameters which have significant effect on the efficiency of saffron separator.

  13. Experimental study on the flow separation and self-excited oscillation phenomenon in a rectangular duct

    Science.gov (United States)

    Xiong, Bing; Wang, Zhen-Guo; Fan, Xiao-Qiang; Wang, Yi

    2017-04-01

    To study the characteristics of flow separation and self-excited oscillation of a shock train in a rectangular duct, a simple test case has been conducted and analyzed. The high-speed Schlieren technique and high-frequency pressure measurements have been adopted to collect the data. The experimental results show that there are two separation modes in the duct under M3 incoming condition. The separation mode switch has great effects on the flow effects, such as the pressure distribution, the standard deviation distribution and so on. The separation mode switch can be judged by the history of pressure standard deviation. When it comes to the self-excited oscillation of a shock train, the frequency contents in the undisturbed region, the intermittent region, and the separated bubble have been compared. It was found that the low-frequency disturbance induced by the upstream shock foot motions can travel downstream and the frequency will be magnified by the separation bubble. The oscillation of the small shock foot and the oscillation of the large shock foot are associated with each other rather than oscillating independently.

  14. Impaired neurogenesis of the dentate gyrus is associated with pattern separation deficits: A computational study.

    Science.gov (United States)

    Faghihi, Faramarz; Moustafa, Ahmed A

    2016-09-01

    The separation of input patterns received from the entorhinal cortex (EC) by the dentate gyrus (DG) is a well-known critical step of information processing in the hippocampus. Although the role of interneurons in separation pattern efficiency of the DG has been theoretically known, the balance of neurogenesis of excitatory neurons and interneurons as well as its potential role in information processing in the DG is not fully understood. In this work, we study separation efficiency of the DG for different rates of neurogenesis of interneurons and excitatory neurons using a novel computational model in which we assume an increase in the synaptic efficacy between excitatory neurons and interneurons and then its decay over time. Information processing in the EC and DG was simulated as information flow in a two layer feed-forward neural network. The neurogenesis rate was modeled as the percentage of new born neurons added to the neuronal population in each time bin. The results show an important role of an optimal neurogenesis rate of interneurons and excitatory neurons in the DG in efficient separation of inputs from the EC in pattern separation tasks. The model predicts that any deviation of the optimal values of neurogenesis rates leads to different decreased levels of the separation deficits of the DG which influences its function to encode memory.

  15. Prospects of Source-Separation-Based Sanitation Concepts: A Model-Based Study

    Directory of Open Access Journals (Sweden)

    Cees Buisman

    2013-07-01

    Full Text Available Separation of different domestic wastewater streams and targeted on-site treatment for resource recovery has been recognized as one of the most promising sanitation concepts to re-establish the balance in carbon, nutrient and water cycles. In this study a model was developed based on literature data to compare energy and water balance, nutrient recovery, chemical use, effluent quality and land area requirement in four different sanitation concepts: (1 centralized; (2 centralized with source-separation of urine; (3 source-separation of black water, kitchen refuse and grey water; and (4 source-separation of urine, feces, kitchen refuse and grey water. The highest primary energy consumption of 914 MJ/capita(cap/year was attained within the centralized sanitation concept, and the lowest primary energy consumption of 437 MJ/cap/year was attained within source-separation of urine, feces, kitchen refuse and grey water. Grey water bio-flocculation and subsequent grey water sludge co-digestion decreased the primary energy consumption, but was not energetically favorable to couple with grey water effluent reuse. Source-separation of urine improved the energy balance, nutrient recovery and effluent quality, but required larger land area and higher chemical use in the centralized concept.

  16. Characterization of size, morphology and elemental composition of nano-, submicron, and micron particles of street dust separated using field-flow fractionation in a rotating coiled column.

    Science.gov (United States)

    Fedotov, Petr S; Ermolin, Mikhail S; Karandashev, Vasily K; Ladonin, Dmitry V

    2014-12-01

    For the first time, nano- and submicron particles of street dust have been separated, weighted, and analyzed. A novel technique, sedimentation field-flow fractionation in a rotating coiled column, was applied to the fractionation of dust samples with water being used as a carrier fluid. The size and morphology of particles in the separated fractions were characterized by electronic microscopy before digestion and the determination of the concentration of elements by ICP-AES and ICP-MS. The elements that may be of anthropogenic origin (Zn, Cr, Ni, Cu, Cd, Sn, Pb) were found to concentrate mainly in particles present only about 0.1 mass% of the sample they are of special concern due to their increased mobility and ability to penetrate into the deepest alveolar area of the lungs. For rare earth elements (La, Ce, Pr, Nd, Sm) that are evidently of natural source and may be found in soil minerals, in contrary, higher concentrations were observed in large particles (10-100 μm). Sc was an exception that needs further studies. The proposed approach to the fractionation and analysis of nano-, submicron, and micron particles can be a powerful tool for risk assessment related to toxic elements in dust, ash, and other particulate environmental samples. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Non-ionic, thermo-responsive DEA/DMA nanogels: synthesis, characterization, and use for DNA separations by microchip electrophoresis.

    Science.gov (United States)

    Lu, Xihua; Sun, Mingyun; Barron, Annelise E

    2011-05-15

    Thermo-responsive polymer "nanogels" (crosslinked hydrogel particles with sub-100 nm diameters) are intriguing for many potential applications in biotechnology and medicine. There have been relatively few reports of electrostatically neutral, thermosensitive nanogels comprising a high fraction of hydrophilic co-monomer. Here we demonstrate the syntheses and characterization of novel, non-ionic nanogels based on random N,N-diethylacrylamide (DEA)/N,N-dimethylacrylamide (DMA) copolymers, made by free-radical, surfactant-free dispersion polymerization. The volume-phase transition temperatures of these DEA/DMA nanogels are strongly affected by co-monomer composition, providing a way to "tune" the phase transition temperature of these non-ionic nanogels. While DEA nanogels (comprising no DMA) can be obtained at 70 °C by standard emulsion precipitation, DEA/DMA random co-polymer nanogels can be obtained only in a particular range of temperatures, above the initial phase transition temperature and below the critical precipitation temperature of the DEA/DMA copolymer, controlled by co-monomer composition. Increasing percentages of DMA in the nanogels raises the phase transition temperature, and attenuates and broadens it as well. We find that concentrated DEA/DMA nanogel dispersions are optically clear at room temperature. This good optical clarity was exploited for their use in a novel DNA sieving matrix for microfluidic chip electrophoresis. An ultrafast, high-efficiency dsDNA separation was achieved in less than 120 s for dsDNA ranging from 75 bp to 15,000 bp. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Separation, Characterization and Dose-Effect Relationship of the PPARγ-Activating Bio-Active Constituents in the Chinese Herb Formulation ‘San-Ao Decoction’

    Directory of Open Access Journals (Sweden)

    Chun-Mei Liu

    2009-10-01

    Full Text Available San-ao decoction (SAD, comprising Herba Ephedrae, Radix et Rhizoma Glycyrrhizae and Seneb Armeniacae Amarum, is one of the most popular traditional Chinese medicine (TCM formulae for asthma. Peroxisome proliferator-activated receptors (PPARs areey regulators of lipid and glucose metabolism and have become important therapeutic targets for various deseases, PPARγ activation might exhibit anti-inflammatory properties in different chronic inflammatory processes. The EtOAc fraction of SAD showed a significant effect on PPARγ activation. A simple and rapid method has been established for separation and characterization of the main compounds in the PPARγ-activating fraction of SAD by ultra-fast HPLC coupled with quadropole time-of-flight mass pectrometry (UPLC-Q-TOF/MS. A total of 10 compounds were identified in the activating fraction of SAD, including amygdalin (1, liquiritin (2, 6′-acetyliquiritin (3, liquiritigenin (4, isoliquiritigenin (5, formononetin (6, licoisoflavanone (7, glycycoumarin (8, glycyrol (9 and uercetin (10. The results also characterized formononetin as a predominant component in this fraction. The dose-effect relationship comparison study of formononetin and the EtOAc fraction of SAD by adding formononetin was performed, the results suggested that formononetin was the major component of the EtOAc fraction of SAD responsible for activating PPARγ, and the method will possibly be applied to study the complex biological active constituents of other TCMs.

  19. Characterization of odorous contaminants in post-consumer plastic packaging waste using multidimensional gas chromatographic separation coupled with olfactometric resolution.

    Science.gov (United States)

    Strangl, Miriam; Fell, Tanja; Schlummer, Martin; Maeurer, Andreas; Buettner, Andrea

    2017-04-01

    The increasing world population with their growing consumption of goods escalates the issue of sustainability concepts with increasing demands in recycling technologies. Recovery of post-consumer packaging waste is a major topic in this respect. However, contamination with odorous constituents currently curtails the production of recycling products that meet the high expectations of both consumers and industry. To guarantee odor-free recyclates, the main prerequisite is to characterize the molecular composition of the causative odorants in post-consumer plastic packaging waste. However, targeted characterization of odorous trace contaminants among an abundance of volatiles is a major challenge and requires specialized and high-resolution analytical approaches. For this aim, post-consumer packaging waste was characterized by sensory analysis and two-dimensional high resolution gas chromatography coupled with mass spectrometry and olfactometry. The 33 identified odorants represent various structural classes as well as a great diversity of smell impressions with some of the compounds being identified in plastics for the first time. Substances unraveled within this study provide insights into sources of odorous contamination that will require specific attention in the future in terms of screening and prevention in recycling products. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Separate Colors, Separate Minds.

    Science.gov (United States)

    Meyers, Michael; Nidiry, John P.

    2002-01-01

    Explains that racial separation causes cultural separation, and the way to improve race relations is to continue to move toward integration. Discusses the need to debunk race, examining racial issues in education. Highlights the importance of actively supporting integration and opposing separatism, explaining that for there to be social progress,…

  1. Synthesis, characterization and studies on antioxidant and ...

    Indian Academy of Sciences (India)

    Abstract. In the present study, a new thiourea derivative bearing benzothiazole ligand, 1-(benzo[d]thiazol-2- yl)thiourea (btt) and its ternary metal (Cu(II), Co(II) and Ni(II)) complexes were synthesized. The structural characterization was carried out by micro analysis, IR, 1H-NMR, EPR, UV-Visible spectral analyses, molar.

  2. Physicochemical Characterization and Dissolution Studies of Solid ...

    African Journals Online (AJOL)

    Physicochemical characterization of the dispersions were performed using differential scanning calorimetry (DSC), x-ray powder diffraction (XRPD) and Fourier transform infrared spectroscopy (FTIR). In vitro drug release was carried out using the rotating disc method. Results: These studies showed that there was no ...

  3. Literature study regarding fire protection in nuclear power plants. Part I: Fire rated separations; Litteraturstudie angaaende brandskydd i kaernkraftverk. Del I: Brandteknisk separation

    Energy Technology Data Exchange (ETDEWEB)

    Isaksson, S. [Swedish Testing and Research Inst., Boraas (Sweden)

    1995-06-01

    This literature study has been made on behalf of the Swedish Nuclear Power Inspectorate. The aim is to describe different aspects of fire protection in nuclear power plants. Conventional building codes can not give guidance on where to make fire rated separations in order to separate redundant trains of safety systems. The separation must originate in functional demands from the authorities on what functions are essential during and after a fire, and under what circumstances these functions shall be retained, i.e. the number of independent faults and initiating events. As a basic demand it is suggested to rate the strength of separations according to conventional building code, based on fire load. The whole separating construction shall have the same fire rating, including the ventilation system. Deviations from the basic demand can de done in case it can be proven that it is possible to compensate some or all of the fire rating with other measures. There is a general lack of statistical information regarding the reliability of fire separating constructions such as walls, fire doors, penetration seals and fire dampers. The amount of cables penetrating a seal is in many cases much higher in real installations than what has been tested for type approval. It would therefore be valuable to perform a furnace test with a more representative amount of cables passing through a penetration seal. Tests have shown that the 20 foot horizontal separation distance stipulated by NRC is not a guarantee against fire damage. Spatial separations based on general requirements shall not be allowed, but considered from case to case based on actual circumstances. For fire protection by isolation or coatings, it is of great importance to choose the method of protection carefully, to be compatible with the material it shall be applied on, and the environment and types of fire that may occur. 48 refs, 2 figs, 5 tabs.

  4. [Paleoclimatology studies for Yucca Mountain site characterization]. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-03

    This report consists of two separate papers: Fernley Basin studies; and Influence of sediment supply and climate change on late Quaternary eolian accumulation patterns in the Mojave Desert. The first study involved geologic mapping of late Quaternary sediments and lacustrine features combined with precise control of elevations and descriptions of sediments for each of the major sedimentary units. The second paper documents the response of a major eolian sediment transport system in the east-central Mojave Desert: that which feeds the Kelso Dune field. Information from geomorphic, stratigraphic, and sedimentologic studies of eolian deposits and landforms is combined with luminescence dating of these deposits to develop a chronology of periods of eolian deposition. Both studies are related to site characterization studies of Yucca Mountain and the forecasting of rainfall patterns possible for the high-level radioactive waste repository lifetime.

  5. Effects of Family Structure and the Experience of Parental Separation: A Study on Adolescents’ Well-Being

    National Research Council Canada - National Science Library

    Sabine Walper; Carolin Thönnissen; Philipp Alt

    2015-01-01

    Large numbers of studies, mostly from the U.S., have addressed the effects of parental separation and divorce, pointing to disadvantages of children and adolescents growing up in separated families...

  6. Lithium isotopic separation: preliminary studies; Separacao isotopica de litio: estudos preliminares

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Sandra Helena Goulart de

    1998-07-01

    In order to get the separation of natural isotopes of lithium by electrolytic amalgamation, an electrolytic cell with a confined mercury cathode was used to obtain data for the design of a separation stage. The initial work was followed by the design of a moving mercury cathode electrolytic cell and three experiments with six batches stages were performed for the determination of the elementary separation factor. The value obtained, 1.053, was ill agreement: with the specialized literature. It was verified in all experiments that the lithium - 6 isotope concentrated in the amalgam phase and that the lithium - 7 isotope concentrated in the aqueous phase. A stainless-steel cathode for the decomposition of the lithium amalgam and the selective desamalgamation were also studied. In view of the results obtained, a five stages continuous scheme was proposed. (author)

  7. A Theoretical Study of the Separation Principle in Size Exclusion Chromatography

    DEFF Research Database (Denmark)

    Wang, Yanwei; Teraoka, Iwao; Hansen, Flemming Yssing

    2010-01-01

    The principle of polymer separation in size exclusion chromatography (SEC) is studied based on a classical equilibrium partitioning theory. The task is to examine the correlation between the mean span dimension of polymer chains and their equilibrium partition coefficients with confining pores. U...

  8. Prospects of Source-Separation-Based Sanitation Concepts: A Model-Based Study

    NARCIS (Netherlands)

    Tervahauta, T.H.; Trang Hoang,; Hernández, L.; Zeeman, G.; Buisman, C.J.N.

    2013-01-01

    Separation of different domestic wastewater streams and targeted on-site treatment for resource recovery has been recognized as one of the most promising sanitation concepts to re-establish the balance in carbon, nutrient and water cycles. In this study a model was developed based on literature data

  9. Removal of Separable Organic From Tank 241-C-103 Scoping Study

    Energy Technology Data Exchange (ETDEWEB)

    KOCH, M.R.

    2000-05-16

    This study is based on previous evaluations/proposals for removing the floating organic layer in C-103. A practical method is described with assumptions, cost and schedule estimates, and risks. Proposed operational steps include bulk organic removal, phase separation, organic washing and offsite disposal, followed by an in-situ polishing process.

  10. Study of 2-input 2-output Blind Signal Separation by Output Decorrelation

    Directory of Open Access Journals (Sweden)

    V. Davidek

    1998-12-01

    Full Text Available The simulations and experiments representing the initial study of the output decorrelation approach to blind signal separation are presented in this paper. The definition of performance indexes for the evaluation and comparison of different algorithms are proposed. Two algorithms are compared. Some first results of real experiments are discussed.

  11. Herbs and spices: characterization and quantitation of biologically-active markers for routine quality control by multiple headspace solid-phase microextraction combined with separative or non-separative analysis.

    Science.gov (United States)

    Sgorbini, Barbara; Bicchi, Carlo; Cagliero, Cecilia; Cordero, Chiara; Liberto, Erica; Rubiolo, Patrizia

    2015-01-09

    Herbs and spices are used worldwide as food flavoring, thus determination of their identity, origin, and quality is mandatory for safe human consumption. An analysis strategy based on separative (HS-SPME-GC-MS) and non-separative (HS-SPME-MS) approaches is proposed for the volatile fraction of herbs and spices, for quality control and to quantify the aromatic markers with a single analysis directly on the plant material as such. Eight-to-ten lots of each of the following herbs/spices were considered: cloves (Syzygium aromaticum (L.) Merr. & Perry), American peppertree (Schinus molle L.), black pepper and white pepper (Piper nigrum L.), rosemary (Rosmarinus officinalis L.), sage (Salvia officinalis L.) and thyme (Thymus vulgaris L.). Homogeneity, origin, and chemotypes of the investigated lots of each herb/spice were defined by fingerprinting, through statistical elaboration with principal component analysis (PCA). Characterizing aromatic markers were directly quantified on the solid matrix through multiple headspace extraction-HS-SPME (MHS-SPME). Reliable results were obtained with both separative and non-separative methods (where the latter were applicable); the two were in full agreement, RSD% ranging from 1.8 to 7.7% for eugenol in cloves, 2.2-18.4% for carvacrol+thymol in thyme, and 3.1-16.8% for thujones in sage. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Sorption separation of Eu and As from single-component systems by Fe-modified biochar. Kinetic and equilibrium study

    Energy Technology Data Exchange (ETDEWEB)

    Fristak, Vladimir; Soja, Gerhard [Austrian Institute of Technology GmbH, Tulln (Austria). Energy Dept. Environmental Resources and Technologies; Michalekova-Richveisova, Barbora; Pipiska, Martin [Trnava Univ. (Slovakia). Dept. of Chemistry; Viglasova, Eva; Galambos, Michal [Comenius Univ., Bratislava (Slovakia). Dept. of Inorganic Chemistry; Duriska, Libor [Slovak Univ. of Technology in Bratislava, Trnava (Slovakia). Faculty of Materials Science and Technology; Moreno-Jimenez, Eduardo [Univ. Autonoma de Madrid (Spain). Dept. de Quimica Agricola y Bromatologia

    2017-03-15

    The utilization of carbonaceous materials in separation processes of radionuclides, heavy metals and metalloids represents a burning issue in environmental and waste management. The main objective of this study was to characterize the effect of chemical modification of corncob-derived biochar by Fe-impregnations on sorption efficiency of Eu and As as a model compounds of cationic lanthanides and anionic metalloids. The biochar sample produced in slow pyrolysis process at 500 C before (BC) and after (IBC) impregnation process was characterized by elemental, FTIR, SEM-EDX analysis to confirm the effectiveness of Fe-impregnation process. The basic physico-chemical properties showed differences in surface area and pH values of BC- and IBC-derived sorbents. Sorption processes of Eu and As by BC and IBC were characterized as a time- and initial concentration of sorbate-dependent processes. The sorption equilibrium was reached for both sorbates in 24 h of contact time. Batch equilibrium experiments revealed the increased maximum sorption capacities (Q{sub max}) of IBC for As about more than 20 times (Q{sub max} BC 0.11 and Q{sub max} IBC 2.26 mg g{sup -1}). Our study confirmed negligible effect of Fe-impregnation on sorption capacity of biochar for Eu (Q{sub max} BC 0.89 and Q{sub max} IBC 0.98 mg g{sup -1}). The iron-impregnation of biochar-derived sorbents can be utilized as a valuable treatment method to produce stable and more effective sorption materials for various xenobiotics separation from liquid wastes and aqueous solutions.

  13. Design and characterization of materials with microphase-separated surface patterns for screening osteoblast response to adhesion

    Science.gov (United States)

    Wingkono, Gracy A.

    Combinatorial techniques have changed the paradigm of materials research by allowing efficient screening of complex materials problems with large, multidimensional parameter spaces. The focus of this thesis is to demonstrate combinatorial methods (CM) and high-throughput methods (HTM) applied to biomaterials design, characterization, and screening. In particular, this work focuses on screening the effects of biomaterial surface features on adherent bone cell cultures. Polymeric biomaterials were prepared on two-dimensional combinatorial libraries that systematically varied the size and shape of chemically-distinct microstructural patterns. These libraries were generated from blends of biodegradable polyurethanes and polyesters prepared with thickness, composition and temperature gradient techniques. Characterization and screening were performed with high-throughput optical and fluorescence microscopy. A unique advance of this work is the application of data mining techniques to identify the controlling structural features that affect cell behavior from among the myriad variety of metrics from the microscope images. Libraries were designed to exhibit chemically-distinct cell-adhesive versus non-adhesive microstructural domains that improve library performance compared to previous implementations that had employed only modest chemical differences. Improving adhesive contrast should minimize combination of effects of chemistry and physical structure, making data interpretation simpler. To accomplish this, a method of blending and crosslinking cell-non-adhesive poly(ethylene glycol) (PEG) with cell-adhesive poly(·-caprolactone) (PCL) was developed. The behavior of MC3T3-E1 osteoblast cells cultured on the PCL-PEG libraries were observed, equivalent to thousands of distinct chemistries and microstructures. Cell spreading area, shape, and density upon adhesion on surface patterns are observed in this study. Characterization of the surface library and screening of

  14. Pseudo-stationary separation materials for highly parallel separations.

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Anup K.; Palmer, Christopher (University of Montana, Missoula, MT)

    2005-05-01

    Goal of this study was to develop and characterize novel polymeric materials as pseudostationary phases in electrokinetic chromatography. Fundamental studies have characterized the chromatographic selectivity of the materials as a function of chemical structure and molecular conformation. The selectivities of the polymers has been studied extensively, resulting in a large body of fundamental knowledge regarding the performance and selectivity of polymeric pseudostationary phases. Two polymers have also been used for amino acid and peptide separations, and with laser induced fluorescence detection. The polymers performed well for the separation of derivatized amino acids, and provided some significant differences in selectivity relative to a commonly used micellar pseudostationary phase. The polymers did not perform well for peptide separations. The polymers were compatible with laser induced fluorescence detection, indicating that they should also be compatible with chip-based separations.

  15. Extraction, separation and characterization of endotoxins in water samples using solid phase extraction and capillary electrophoresis-laser induced fluorescence.

    Science.gov (United States)

    Fung, Fun Man; Su, Min; Feng, Hua-Tao; Li, Sam Fong Yau

    2017-09-07

    This study focuses on one of the key environmental threats, endotoxins, also known as lipopolysaccharides (LPS). A capillary electrophoresis method in combination with laser induced fluorescence (LIF) detection was developed for the analysis of endotoxins from 16 different bacterial strains. LPSs were derivatized with the amino-reactive fluorescent dye, fluorescein isothiocyanate (FITC), separated by capillary zone electrophoresis (CZE) under the optimized conditions with the use of 50 mM sodium tetraborate buffer (pH 9.30), and detected by LIF detector. To improve the sensitivity of CZE-LIF detection for the determination of trace amounts of endotoxins and to remove possible interference materials in environmental samples, a solid phase extraction (SPE) pre-concentration technique was applied successfully. The SPE targeted at polysaccharide moieties of LPSs and showed LPS enrichment effects too. CE migration time could also reveal the O-antigen chain lengths of LPSs. This CE method and SPE pretreatment showed linearity at 99.84%, and repeatabilities at 8.44% and 11.0% for endotoxins from E. Coli O55:B5 and E. Coli O26:B6. The limit of detection (LOD) could reach around 5 ng/mL at optimized condition. The method was applied successfully to the determination of LPS levels in tap water and wastewater, and demonstrated sensitive, reproducible and reliable results.

  16. Severe congenital malformations, family functioning and parents' separation/divorce: a longitudinal study.

    Science.gov (United States)

    Brenner, M; Côté, S M; Boivin, M; Tremblay, R E

    2016-01-01

    We aim to explore the association of a severe congenital malformation (SCM) with postnatal family functioning and parents' separation/divorce and to examine if this association might be moderated by birth order of the child and parental level of education. SCM refers to malformations that, without medical intervention, cause handicap or death. Using the Quebec Longitudinal Study of Child Development, an ongoing population-based birth cohort study initiated in 1998, we compared 1675 families of children with and without a SCM to identify if having a child with a SCM was associated with maternal perception of family functioning. We examined if an SCM was associated with parents' separation and examined parents' education level and birth order of the children to evaluate whether these factors had any moderating effect on the results. There were no significant differences in family functioning between families with and without a SCM child at 5 and 17 months. At 5 months, family functioning was significantly better (P = 0.03) for families with a SCM firstborn child than for families with a SCM child that is not firstborn. For parental separation, no significant differences were observed at 5 and 29 months and 4 years. No significant moderating effects were observed for birth order and parental education on parental separation. Families of children with a SCM do not appear to be at higher risk of family dysfunction within the first 17 months after birth nor of parental separation within the first 4 years after birth. Family functioning tends to be worst in families where the child with SCM is the second or subsequent child born. © 2015 John Wiley & Sons Ltd.

  17. A fracture mechanics study of the phase separating planar electrodes: Phase field modeling and analytical results

    Science.gov (United States)

    Haftbaradaran, H.; Maddahian, A.; Mossaiby, F.

    2017-05-01

    It is well known that phase separation could severely intensify mechanical degradation and expedite capacity fading in lithium-ion battery electrodes during electrochemical cycling. Experiments have frequently revealed that such degradation effects could be substantially mitigated via reducing the electrode feature size to the nanoscale. The purpose of this work is to present a fracture mechanics study of the phase separating planar electrodes. To this end, a phase field model is utilized to predict how phase separation affects evolution of the solute distribution and stress profile in a planar electrode. Behavior of the preexisting flaws in the electrode in response to the diffusion induced stresses is then examined via computing the time dependent stress intensity factor arising at the tip of flaws during both the insertion and extraction half-cycles. Further, adopting a sharp-interphase approximation of the system, a critical electrode thickness is derived below which the phase separating electrode becomes flaw tolerant. Numerical results of the phase field model are also compared against analytical predictions of the sharp-interphase model. The results are further discussed with reference to the available experiments in the literature. Finally, some of the limitations of the model are cautioned.

  18. Direct numerical simulation of flow separation behind a rounded leading edge: Study of curvature effects

    Energy Technology Data Exchange (ETDEWEB)

    Lamballais, Eric, E-mail: lamballais@univ-poitiers.f [Institute PPRIME, Department of Fluid Flow, Heat Transfer and Combustion, Universite de Poitiers, ENSMA, CNRS, Teleport 2 - Bd. Marie et Pierre Curie B.P. 30179, 86962 Futuroscope Chasseneuil Cedex (France); Silvestrini, Jorge, E-mail: jorgehs@pucrs.b [Faculdade de Engenharia, Pontificia Universidade Catolica do Rio Grande do Sul, Av. Ipiranga 6681, 90619-900 Porto Alegre - RS (Brazil); Laizet, Sylvain, E-mail: s.laizet@imperial.ac.u [Institute PPRIME, Department of Fluid Flow, Heat Transfer and Combustion, Universite de Poitiers, ENSMA, CNRS, Teleport 2 - Bd. Marie et Pierre Curie B.P. 30179, 86962 Futuroscope Chasseneuil Cedex (France); Department of Aeronautics, Institute for Mathematical Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom)

    2010-06-15

    The separation bubble formed over a 2D half-body is studied by direct numerical simulation. The aim of this work is to consider the physical influence of the shape of the body that can be viewed as a thick half-plate with a front edge more or less rounded. The present generic body geometry is defined with a unique parameter {eta}=R/H corresponding to the ratio of the curvature radius R of the front edge over the body height H. In this paper, 18 calculations are presented depending on: (i) the value of {eta} with {eta}=0.125,0.25,0.5,1; (ii) the 2D/3D nature of the computation; (iii) the inflow perturbations used to mimic residual turbulence in the free stream velocity U{sub {infinity}.} Only one Reynolds number Re=U{sub {infinity}H}/{nu} is used for every simulation, allowing us to focus on the curvature effects over the separation bubble dynamics. The value of the Reynolds number (Re=2000) combined with the resolution demand of the front edge (close to a sharp corner for the highest curvature case) requires to simulate the flow using up to 876 million mesh nodes. The curvature effects are found to deeply influence the separation bubble dynamics, with a significant expansion of the separated region size predicted by 3D computations. This expansion is driven by the separation angle rise combined with the reinforcement of turbulence levels as the curvature is increased. These trends are associated with a change of bubble sensitivity with respect to upstream/downstream perturbations that can be interpreted in terms of convective/absolute stability.

  19. The study of acceptance and the transmission efficiency of separated sector cyclotron

    Directory of Open Access Journals (Sweden)

    Li Xiaoni

    2015-01-01

    Full Text Available In this paper we present the study of the transversal and longitudinal acceptance and the transmission efficiency in the injection, acceleration, and extraction systems in the separated sector cyclotron of the heavy ion research facility in Lanzhou, China. The study of cyclotron acceptance is done for 238U36+ with energy of 97 MeV/u and for 70Zn10+ with energy of 5.62 MeV/u under the theoretical isochronous and real magnetic field distribution. From the simulation results it can be seen that the transmission efficiency and the acceptances of separated sector cyclotron can be improved by redesign the curvature of MSI3 deflector or by introducing the magnet shim in MSI3 deflector region to change the distribution of the inner magnetic field. [Projekat Ministarstva nauke Republike Srbije, br. OI-171018

  20. Study of frequency and time responses of a separated absorption and multiplication region avalanche photodiode

    CERN Document Server

    Banoushi, A; Setayeshi, S

    2003-01-01

    In this paper, the frequency and time responses of a separated absorption and multiplication avalanche photodiode are studied by solving the carrier continuity equations, in the low gain regime. The discrepancy between the carrier velocities in different layers is considered for the first time. It is shown that considerable error occurs, if the device d characteristics are calculated assuming uniformly distributed velocities in the depletion layer, especially when the different layers have almost equal thickness.

  1. Numerical Study of Separated Flows in Backward Facing Step by Using Collocated Grid Arrangement

    Directory of Open Access Journals (Sweden)

    Ahmed Mustafa

    2013-05-01

    Full Text Available The effects of Reynolds number and the inlet height ratio on separated flow over backward facing step are investigated. The flow field is studied numerically with different inlet height ratio. The laminar flow field is analyzed numerically by solving the steady, two-dimensional incompressible Navier-Stokes equations. A collocated (non-staggered grid is used in the momentum equations, which discretized by finite volume method, SIMPLE algorithm is used to adjust the velocity field to satisfy the conservation of mass. The range of Reynolds number is (Re = 100 - 800. The results show that at low height ratio (h/H = 0.25 and high Reynolds number the flow separated along the top wall of the channel. Good agreement with the experimental data is obtained. 

  2. A Study on separation of accounts for introducing operation division system in KEPCO

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Sung Han [Korea Energy Economics Institute, Euiwang (Korea)

    1999-03-01

    The power industry has faced deregulation and opening market which have been a global trend. As a prerequisite for introducing such competitions, forming the basis of fair competition has been a great interest. For establishing the basis of fair competition, the need of reviewing accounting system of power industry and defining and improving the problems of existing accounting system are rising as an institutional preparation. The purpose of this study is to provide a framework for unified accounting system of power industry and a scheme for introducing a separation of accounts in order to assure fair competition. The separation of accounts in power industry is an essential system of fair competition since this is a process of distributing cost by sector and function under the reasonable standards by preventing internal support. (author). 32 refs., 8 figs., 3 tabs.

  3. Novel studies of molecular orientation in synthetic polymeric membranes for gas separation

    CERN Document Server

    Ismail, A F

    1998-01-01

    The main objective of this investigation was to produce a super-selective asymmetric membrane for gas separation. To achieve this, molecular orientation induced by rheological conditions during membrane fabrication was investigated and related to the gas separation performance of flat sheet and hollow fiber membranes. Infrared dichroism, a spectroscopic technique, was developed in the first phase of the research to directly measure molecular orientation in flat sheet membranes. The degree of molecular orientation was found to increase with increasing shear during fabrication which enhanced both pressure-normalised flux and selectivity of the coated membranes. The rheology of polymer solutions and the mechanism of molecular orientation have been treated in detail for membrane production. This is a novel approach since previous fundamental work has focused on the phase inversion process. The current study showed that rheological conditions during membrane fabrication have the utmost importance in enhancing memb...

  4. Charge separation in a niobate nanosheet photocatalyst studied with photochemical labeling.

    Science.gov (United States)

    Sabio, Erwin M; Chi, Miaofang; Browning, Nigel D; Osterloh, Frank E

    2010-05-18

    Photolabeling was employed to probe charge separation and the distribution of redox-active sites on the surface of nanosheets derived from the layered photocatalysts KCa(2)Nb(3)O(10). Electron microscopy reveals 1-50 nm particles of silver, gold, iridium oxide, and manganese dioxide particles and small atomically sized clusters of platinum and IrO(x) on the nanosheet surfaces and along the edges. The sizes, shapes, and particle densities vary with the deposition conditions, i.e., the precursor concentration and the presence of sacrificial agents. Overall, the study shows that photogenerated electrons and holes are accessible throughout the nanosheets, without evidence for spatial charge separation across the sheet.

  5. A Systematic Study of Separators in Air-Breathing Flat-Plate Microbial Fuel Cells—Part 1: Structure, Properties, and Performance Correlations

    Directory of Open Access Journals (Sweden)

    Sona Kazemi

    2016-01-01

    Full Text Available Passive air-breathing microbial fuel cells (MFCs are a promising technology for energy recovery from wastewater and their performance is highly dependent on characteristics of the separator that isolates the anaerobic anode from the air-breathing cathode. The goal of the present work is to systematically study the separator characteristics and its effect on the performance of passive air-breathing flat-plate MFCs (FPMFCs. This was performed through characterization of structure, properties, and performance correlations of eight separators in Part 1 of this work. Eight commercial separators were characterized, in non-inoculated and inoculated setups, and were examined in passive air-breathing FPMFCs with different electrode spacing. The results showed a decrease in the peak power density as the oxygen and ethanol mass transfer coefficients in the separators increased, due to the increase of mixed potentials especially at smaller electrode spacing. Increasing the electrode spacing was therefore desirable for the application of diaphragms. The highest peak power density was measured using Nafion®117 with minimal electrode spacing, whereas using Nafion®117 or Celgard® with larger electrode spacing resulted in similar peak powers. Part 2 of this work focuses on numerical modelling of the FPMFCs based on mixed potential theory, implementing the experimental data from Part 1.

  6. Development of Multiscale Materials in Microfluidic Devices: Case Study for Viral Separation from Whole Blood

    Science.gov (United States)

    Surawathanawises, Krissada

    Separation and concentration of nanoscale species play an important role in various fields such as biotechnology, nanotechnology and environmental science. Inevitably, the separation efficiency strongly affects the quality of downstream detections or productions. Innovations in materials science that can separate bionanoparticles efficiently and do not require complex setups, reagents or external fields are highly demanded. This work focuses on developing new materials for the affinity separation of bio-nanoparticles such as viruses or macromolecules from a complex mixture, such as whole blood. To enhance the interaction between target nanoparticles and the capture bed, methods to produce porous matrices with a uniform pore size matching the dimension of targets are studied. Furthermore, regarding viral separation from whole blood, macroporous materials are further patterned into microarrays to allow multiscale separation. Considering the needs in resource-limited settings, these materials are integrated with microfluidic technologies to reduce the volume of samples and reagents, simplify operating processes, and enable the use of inexpensive and portable components. Beyond the application of viral separation as demonstrated in the work, the fundamental study of macroporous material formation and transport in these materials also shed light to the separation of many other nanospecies in multiscale materials. Specifically, two macroporous materials, based on template synthesis, are created in this work. The first type employs porous anodic aluminum oxide (AAO) films as the template to create hexagonal arrays of nanoposts. However, pore sizes and interpore distances (cell size) of ordered porous AAO films are limited by the conventional fabrication process. Moreover, the process usually yields defective pore morphologies and large pore and cell size distributions. To overcome these limitations, a patterning method using nanobead indentation on aluminum substrate

  7. Chromatographic enrichment and subsequent separation of nickel and vanadyl porphyrins from natural seeps and molecular characterization by positive electrospray ionization FT-ICR mass spectrometry.

    Science.gov (United States)

    Putman, Jonathan C; Rowland, Steven M; Corilo, Yuri E; McKenna, Amy M

    2014-11-04

    We report a novel chromatographic method to enrich and separate nickel and vanadyl porphyrins from a natural seep sample and combine molecular level characterization by positive-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Vanadyl and nickel porphyrin model compound elution from primary secondary amine (PSA) stationary phase combined with UV-vis spectroscopy confirms enrichment and subsequent fractionation of nickel and vanadyl porphyrins into polarity-based subfractions. A more than 100-fold increase in signal-to-noise ratio for nickel porphyrins enables unequivocal elemental composition assignment confirmed by isotopic fine structure for all isotopes >1% relative abundance, and the first mass spectral identification of (61)Ni porphyrin isotopologues derived from natural seeps. Oxygen-containing vanadyl porphyrins and sulfur-containing vanadyl porphyrins are isolated in the same fraction simultaneously from the same sample. We provide the first chromatographic evidence of carboxylic acid functionalities peripheral to the porphyrin core, in agreement with previous studies.

  8. [Study of the follow-up by the general practitioner of the children of separated parents].

    Science.gov (United States)

    Kacenelenbogen, N; Roland, M; Schetgen, M; Dusart, A F

    2006-09-01

    In Belgium, on 10 millions of inhabitants, there are more than 31.000 divorces per year and we estimate that 600.000 children are experiencing separation of their parents. The general practitioner (GP) have inevitably the responsability of the medical follow-up of some of these children. The possible professional implications related to these young patients, concerning the GP have never been the subject of a study so far. Consequently the aim of this research was to reveal what is happening in the daily practice of the family practitioner related with the children of separete parents. There were some hypothesis notably about particular working conditions for the GP in connection with possible consequences for these children and possible necessity of special professional attitudes. A qualitative research in focus group was organized with GPs in order to get an interaction between the participants and to go past the concepts supposed before the study. Therefore between September and December 04, 8 focus groups of 10-18 generalist practitioners were set up in Brussels and Mons. Each meeting was axed around couples separated for less than 3 years and children between 0 and 15 years. Finally, 120 GPs discussed about 242 cases of divorces from their practice. The debates totally typed word by word were analysed with assistance of the software QSR N5. The point of view of the GPs is: 1) A divorce affects the working conditions of the general practitioner, for example the parcelling out of the medical follow-up of the child and the fact " of being used" by the family. 2) The conflict between the parents after the separation increases the difficulties for the GP in his daily practice. 3) The parental's separation influences the choice of professional attitudes of the GP, notably vis-a-vis the conflict (for instance to try or not to try the conflict's management). 4) Mainly in conflict situation, parental divorce is a risk for the child; psychological or behavioural

  9. Are Attitudes Toward Writing and Reading Separable Constructs? A Study With Primary Grade Children

    Science.gov (United States)

    Graham, Steve; Berninger, Virginia; Abbott, Robert

    2012-01-01

    This study examined whether or not attitude towards writing is a unique and separable construct from attitude towards reading for young, beginning writers. Participants were 128 first-grade children (70 girls and 58 boys) and 113 third-grade students (57 girls and 56 boys). Each child was individually administered a 24 item attitude measure, which contained 12 items assessing attitude towards writing and 12 parallel items for reading. Students also wrote a narrative about a personal event in their life. A factor analysis of the 24 item attitude measure provided evidence that generally support the contention that writing and reading attitudes are separable constructs for young beginning writers, as it yielded three factors: a writing attitude factor with 9 items, a reading attitude factor with 9 parallel items, and an attitude about literacy interactions with others factor containing 4 items (2 items in writing and 2 parallel items in reading). Further validation that attitude towards writing is a separable construct from attitude towards reading was obtained at the third-grade level, where writing attitude made a unique and significant contribution, beyond the other two attitude measures, to the prediction of three measures of writing: quality, length, and longest correct word sequence. At the first-grade level, none of the 3 attitude measures predicted students’ writing performance. Finally, girls had more positive attitudes concerning reading and writing than boys. PMID:22736933

  10. Parental separation anxiety and diabetes self-management of older adolescents: a pilot study.

    Science.gov (United States)

    Morrison, Shannon; Dashiff, Carol; Abdullatif, Hussein; Moreland, Elaine

    2012-01-01

    Parents of high school seniors with type 1 diabetes mellitus are faced with many concerns and fears as their adolescent prepares to assume primary disease management responsibility and leave the parental residence. The purpose of this study was to explore the relationship between parental separation anxiety and adolescent self-management and glycemic control. A second aim was to assess the relationship between adolescent self-management and glycemic control. Twenty-three families who had adolescents 16 to 18 years of age in or entering in their senior year of high school were recruited. Adolescents from higher income families reported better self-management skills than those from poorer families (r = 0.410, p = 0.05). Length of time since diabetes diagnosis was inversely related to glycemic control (r = 0.448, p = 0.02), indicating that adolescents who had the disease longer had poorer control. Parental separation anxiety was not related to adolescent self-management. Adolescent self-management was negatively related to glycemic control (r = -0.370, p = 0.08), suggesting that adolescents who demonstrated better self-management skills had improved glycemic control in comparison to adolescents who did not demonstrate effective self-management skills. Paternal, not maternal, separation anxiety demonstrated a significant relationship with glycemic control (r = 0.639, p < 0.001).

  11. Further theoretical studies of modified cyclone separator as a diesel soot particulate emission arrester.

    Science.gov (United States)

    Mukhopadhyay, N; Bose, P K

    2009-10-01

    Soot particulate emission reduction from diesel engine is one of the most emerging problems associated with the exhaust pollution. Diesel particulate filters (DPF) hold out the prospects of substantially reducing regulated particulate emissions but the question of the reliable regeneration of filters still remains a difficult hurdle to overcome. Many of the solutions proposed to date suffer from design complexity, cost, regeneration problem and energy demands. This study presents a computer aided theoretical analysis for controlling diesel soot particulate emission by cyclone separator--a non contact type particulate removal system considering outer vortex flow, inner vortex flow and packed ceramic fiber filter at the end of vortex finder tube. Cyclone separator with low initial cost, simple construction produces low back pressure and reasonably high collection efficiencies with reduced regeneration problems. Cyclone separator is modified by placing a continuous ceramic packed fiber filter placed at the end of the vortex finder tube. In this work, the grade efficiency model of diesel soot particulate emission is proposed considering outer vortex, inner vortex and the continuous ceramic packed fiber filter. Pressure drop model is also proposed considering the effect of the ceramic fiber filter. Proposed model gives reasonably good collection efficiency with permissible pressure drop limit of diesel engine operation. Theoretical approach is predicted for calculating the cut size diameter considering the effect of Cunningham molecular slip correction factor. The result shows good agreements with existing cyclone and DPF flow characteristics.

  12. Atomic spectroscopy studies of short-lived isotopes and nuclear isomer separation with the ISOLDE RILIS

    CERN Document Server

    Fedosseev, V; Weissman, L; Mishin, V I; Federov, D V; Seliverstov, D M; Horn, R; Huber, G; Lassen, J; Wendt, K

    2003-01-01

    The Resonance Ionization Laser Ion Source (RILIS) at the ISOLDE on-line isotope separator is based on the selective excitation of atomic transitions by tunable laser radiation. Ion beams of isotopes of 20 elements have been produced using the RILIS setup. Together with the mass separator and a particle detection system it represents a tool for high-sensitive laser spectroscopy of short-lived isotopes. By applying narrow-bandwidth lasers for the RILIS one can study isotope shifts (IS) and hyperfine structure (HFS) of atomic optical transitions. Such measurements are capable of providing data on nuclear charge radii, spins and magnetic moments of exotic nuclides far from stability. Although the Doppler broadening of the optical absorption lines limits the resolution of the technique, the accuracy of the HFS measurements examined in experiments with stable Tl isotopes approaches a value of 100 MHz. Due to the hyperfine splitting of atomic lines the RILIS gives an opportunity to separate nuclear isomers. Isomer s...

  13. Oxidation of polycrystalline Ni studied by spectromicroscopy: Phase separation in the early stages of crystallite growth

    Science.gov (United States)

    Cornish, A.; Eralp, T.; Shavorskiy, A.; Bennett, R. A.; Held, G.; Cavill, S. A.; Potenza, A.; Marchetto, H.; Dhesi, S. S.

    2010-02-01

    Low-energy and photoemission electron microscopy enables the determination of facet planes of polycrystalline surfaces and the study of their chemical composition at the sub- μm scale. Using these techniques the early oxidation stages of nickel were studied. After exposing the surface to 20 L of oxygen at 373 K a uniform layer of chemisorbed oxygen was found on all facets. After oxygen exposure at 473-673 K, small NiO crystallites are formed on all facets but not in the vicinity of all grain boundaries. The crystallites are separated by areas of bare Ni without significant oxygen coverage.

  14. Branched polymers characterized by comprehensive two-dimensional separations with fully orthogonal mechanisms: molecular-topology fractionation×size-exclusion chromatography.

    Science.gov (United States)

    Edam, Rob; Mes, Edwin P C; Meunier, David M; Van Damme, Freddy A; Schoenmakers, Peter J

    2014-10-31

    Polymer separations under non-conventional conditions have been explored to obtain a separation of long-chain branched polymers from linear polymers with identical hydrodynamic size. In separation media with flow-through channels of the same order as the size of the analyte molecules in solution, the separation and the elution order of polymers are strongly affected by the flow rate. At low flow rates, the largest polymers are eluted last. At high flow rates, they are eluted first. By tuning the channel size and flow rate, conditions can be found where separation becomes independent of molar mass or size of linear polymers. Long-chain branched polymers did experience lower migration rates under these conditions and can be separated from linear polymers. This type of separation is referred to as molecular-topology fractionation (MTF) at critical conditions. Separation by comprehensive two-dimensional molecular-topology fractionation and size-exclusion chromatography (MTF×SEC) was used to study the retention characteristics of MTF. Branching selectivity was demonstrated for three- and four-arm "star" polystyrenes of 3-5×10(6)g/mol molar mass. Baseline separation could be obtained between linear polymer, Y-shaped molecules, and X-shaped molecules in a single experiment at constant flow rate. For randomly branched polymers, the branching selectivity inevitably results in an envelope of peaks, because it is not possible to fully resolve the huge numbers of different branched and linear polymers of varying molar mass. It was concluded that MTF involves partial deformation of polymer coils in solution. The increased coil density and resistance to deformation can explain the different retention behavior of branched molecules. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Experimental and Model Studies on Continuous Separation of 2-Phenylpropionic Acid Enantiomers by Enantioselective Liquid-Liquid Extraction in Centrifugal Contactor Separators.

    Science.gov (United States)

    Feng, Xiaofeng; Tang, Kewen; Zhang, Pangliang; Yin, Shuangfeng

    2016-03-01

    Multistage enantioselective liquid-liquid extraction (ELLE) of 2-phenylpropionic acid (2-PPA) enantiomers using hydroxypropyl-β-cyclodextrin (HP-β-CD) as extractant was studied experimentally in a counter-current cascade of centrifugal contactor separators (CCSs). Performance of the process was evaluated by purity (enantiomeric excess, ee) and yield (Y). A multistage equilibrium model was established on the basis of single-stage model for chiral extraction of 2-PPA enantiomers and the law of mass conservation. A series of experiments on the extract phase/washing phase ratio (W/O ratio), extractant concentration, the pH value of aqueous phase, and the number of stages was conducted to verify the multistage equilibrium model. It was found that model predictions were in good agreement with the experimental results. The model was applied to predict and optimize the symmetrical separation of 2-PPA enantiomers. The optimal conditions for symmetric separation involves a W/O ratio of 0.6, pH of 2.5, and HP-β-CD concentration of 0.1 mol L(-1) at a temperature of 278 K, where eeeq (equal enantiomeric excess) can reach up to 37% and Yeq (equal yield) to 69%. By simulation and optimization, the minimum number of stages was evaluated at 98 and 106 for eeeq > 95% and eeeq > 97%. © 2016 Wiley Periodicals, Inc.

  16. Characterization of gel-separated glycoproteins using two-step proteolytic digestion combined with sequential microcolumns and mass spectrometry

    DEFF Research Database (Denmark)

    Larsen, Martin Røssel; Højrup, Peter; Roepstorff, Peter

    2005-01-01

    Protein glycosylation can be vital for changing the function or physiochemical properties of a protein. Abnormal glycosylation can lead to protein malfunction, resulting in severe diseases. Therefore, it is important to develop techniques for characterization of such modifications in proteins at ...

  17. RP-HPLC separation and characterization of unknown impurities of a novel HIV-protease inhibitor Darunavir by ESI-MS and 2D NMR spectroscopy.

    Science.gov (United States)

    Nageswara Rao, Ramisetti; Ramachandra, Bondigalla; Santhakumar, Kondapalli

    2013-03-05

    A selective RP-HPLC method for separation and determination of darunavir from its process related substances has been developed and validated. The separation was accomplished on a Hiber, LiChrospher 60, RP-select B, C₈ (250 mm × 4.6 mm, 5 μm) column connected to a photo diode array detector (PDA) using 10 mM phosphate buffer with 0.1% of triethylamine (pH: 4.0 adjusted with orthophosphoric acid)/acetonitrile as a mobile phase under gradient elution. Two unknown impurities of darunavir were isolated and characterized by ¹H, ¹³C, 2D-NMR and mass spectrometry. The method was validated in terms of accuracy, precision, linearity, robustness, LOD and LOQ. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Is burnout separable from depression in cluster analysis? A longitudinal study.

    Science.gov (United States)

    Bianchi, Renzo; Schonfeld, Irvin Sam; Laurent, Eric

    2015-06-01

    Whether burnout and depression represent distinct pathologies is unclear. The aim of this study was to examine whether burnout and depressive symptoms manifest themselves separately from each other or are so closely intertwined as to reflect the same phenomenon. A two-wave longitudinal study involving 627 French schoolteachers (73 % female) was conducted. Burnout was assessed with the Maslach Burnout Inventory and depression with the 9-item depression module of the Patient Health Questionnaire. Burnout and depressive symptoms clustered both at baseline and follow-up. Cluster membership at time 1 (T1) predicted cases of burnout and depression at time 2 (T2), controlling for gender, age, length of employment, lifetime history of depression, and antidepressant intake. Changes in burnout and depressive symptoms from T1 to T2 were found to overlap. Teachers with increasing burnout experienced increases in depression and teachers with decreasing burnout experienced decreases in depression. In addition, emotional exhaustion, the core of burnout, was more strongly associated with depression than with depersonalization, the second dimension of burnout, underlining an inconsistency in the conceptualization of the burnout syndrome. Our results are consistent with recent findings showing qualitative and quantitative symptom overlap of burnout with depression. The close interconnection of burnout and depression questions the relevance of a nosological distinction between the two entities. Emotional exhaustion and depersonalization, the two main dimensions of burnout, may be better conceptualized as depressive responses to adverse occupational environments than as components of a separate entity.

  19. Neutron diffraction study of unusual phase separation in the antiperovskite nitride Mn3ZnN.

    Science.gov (United States)

    Sun, Ying; Wang, Cong; Huang, Qingzhen; Guo, Yanfeng; Chu, Lihua; Arai, Masao; Yamaura, Kazunari

    2012-07-02

    The antiperovskite Mn(3)ZnN is studied by neutron diffraction at temperatures between 50 and 295 K. Mn(3)ZnN crystallizes to form a cubic structure at room temperature (C1 phase). Upon cooling, another cubic structure (C2 phase) appears at around 177 K. Interestingly, the C2 phase disappears below 140 K. The maximum mass concentration of the C2 phase is approximately 85% (at 160 K). The coexistence of C1 and C2 phase in the temperature interval of 140-177 K implies that phase separation occurs. Although the C1 and C2 phases share their composition and lattice symmetry, the C2 phase has a slightly larger lattice parameter (Δa ≈ 0.53%) and a different magnetic structure. The C2 phase is further investigated by neutron diffraction under high-pressure conditions (up to 270 MPa). The results show that the unusual appearance and disappearance of the C2 phase is accompanied by magnetic ordering. Mn(3)ZnN is thus a valuable subject for study of the magneto-lattice effect and phase separation behavior because this is rarely observed in nonoxide materials.

  20. Characterization of S-hexylglutathione-binding proteins of human hepatocellular carcinoma: separation of enoyl-CoA isomerase from an Alpha class glutathione transferase form.

    Science.gov (United States)

    Kajihara-Kano, H; Hayakari, M; Satoh, K; Tomioka, Y; Mizugaki, M; Tsuchida, S

    1997-01-01

    Recent studies have revealed binding of mitochondrial enoyl-CoA isomerase (ECI) to S-hexylglutathione-Sepharose, an affinity matrix used for purification of glutathione transferases (GSTs), and the enzyme has been suggested to be identical with the Alpha class form of GST with a subunit molecular mass of about 30 kDa. In the present study, S-hexylglutathione-binding proteins of human hepatocellular carcinomas were characterized to examine their identity. Supernatant fractions of carcinoma and surrounding tissues were applied to an affinity column, and bound fractions were resolved into three proteins with subunit molecular masses/pI values of 33 kDa/7.0, 30 kDa/5.8 and 29 kDa/5.8 in addition to the well-characterized four GST subunits, A1, A2, M1 and P1, by two-dimensional gel electrophoresis. The proteins were further purified by chromatofocusing at pH 7.4-4.0. The 30 and 29 kDa proteins were eluted at pH 4.9 and by 1 M NaCl respectively, and could be clearly separated from each other. The 29 kDa protein exhibited a low but significant activity towards 1-chloro-2,4-dinitrobenzene (4.25 micromol/min per mg of protein) and reacted with anti-(GST A1-2) antibody, suggesting that it is a member of the GST Alpha class. The 30 kDa protein did not react with anti-GST antibodies and was identified as ECI by immunoblotting and N-terminal-amino-acid-sequencing analyses. The results thus indicated that the Alpha class GST form composed of the 29 kDa subunits and ECI are two different proteins. The 33 kDa protein was eluted from the chromatofocusing column at pH 7.0 and did not react with either anti-GST antibodies or antibodies against mitochondrial enzymes involved in the beta-oxidation of fatty acids. However, it exhibited a carbonyl reductase activity with menadione and ubiquinone, and amino acid sequences of its peptides cleaved by Staphylococcus aureus V8 proteinase were consistent with those reported for the enzyme. Thus this protein binding to S

  1. SYNTHESIS, CHARACTERIZATION STUDIES OF 2-[(2 ...

    African Journals Online (AJOL)

    User

    2016-06-01

    Jun 1, 2016 ... Antioxidant picryhydrazyl (DPPH) and the results were the ligand and copper (II) complexes pos ... r (II) complexes possess antioxidant property while zinc (II) comp bial, Antioxidant, Characterization, Ligand, ..... complexes of copper and zinc were synthesi the compounds were characterized. Antimicrob.

  2. Correlates of separation anxiety symptoms among first-semester college students: an exploratory study.

    Science.gov (United States)

    Seligman, Laura D; Wuyek, Lisa A

    2007-03-01

    Separation anxiety disorder (SAD) is rarely considered in college students with anxious symptomatology, but a growing body of evidence suggests that its symptoms are experienced by a significant number of young adults. The authors examined separation anxiety symptoms in a group of first-semester college students living on campus and experiencing extended separation from significant others, generally for the first time. They examined prevalence of separation anxiety symptoms among college students and the relationship between separation anxiety symptoms and students' educational decisions and performance. Results showed that 21% of first-semester college students reported symptoms of separation anxiety. In addition, separation anxiety symptoms were related to childhood SAD, panic attacks, and educational decisions. Results suggest that SAD may be a valid diagnosis in college students and may impact their educational choices and experiences.

  3. Characterization of sodium stibogluconate by online liquid separation cell technology monitored by ICPMS and ESMS and computational chemistry

    DEFF Research Database (Denmark)

    Hansen, Helle Rusz; Hansen, Claus; Kepp, Kasper Planeta

    2008-01-01

    High-performance liquid chromatography (HPLC), mass spectrometry (MS), and computational chemistry has been applied to resolve the composition and structure of the Sb species present in dilutions of Pentostam, a first-line treatment drug against Leishmania parasites. Using HPLC-inductively coupled......(V)-glyconate complexes of various stoichiometry (1:1, 1:2, 1:3, 2:2, 2:3, 2:4, 3:3, 3:4). The 1:1 complex became the most abundant low molecular mass Sb(V) complex with dilution time. A novel mixed-mode chromatographic system was applied in order to separate complexes of various stoichiometry and isomers. Density...

  4. A Toxicology and Characterization Study of Microplastics

    Science.gov (United States)

    Parker, Amy; Sullivan, Kelley; n/a Collaboration

    Plastic is everywhere. Microplastic particles are found in our toothpaste and soap, and are also created when larger plastics degrade under natural forces and sunlight. Studies have shown that filter feeders in aquatic systems eat microplastics, which transports plastic up the food chain. We used fluorescence microscopy to characterize the size, shape, and types of plastic found in several personal care products in order to create a clear picture of a significant source of microplastics found in our local Cayuga Lake ecosystem in Upstate New York. We also studied toxin absorption and emission of these plastics using environmentally relevant concentrations of BPA. For Neutrogena face scrub, the microplastics were polyethylene and roughly pill shaped. The majority of these microplastics are either smaller than 0.1 mm2, or were distributed in a bell-shaped curve about 0.5 mm2. The concentration of a solution of environmentally relevant BPA that microplastics were immersed in decreased by 13% over a 12-hour period. These results indicate that these microplastics pose a threat to organisms in the environment - they are small enough and shaped appropriately to be mistaken as prey, and they absorb toxins quickly. As the number of microplastics exponentially build up in the environment, the food chain will be negatively affected. Ithaca College DANA Student Internship program.

  5. Fabrication and characterization of chromium-doped nanophase separated yttria-alumina-silica glass-based optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Dutta, Debjit; Dhar, Anirban; Das, Shyamal; Paul, Mukul C. [Fiber Optics and Photonics Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata (India); Kir' yanov, Alexander V. [Centro de Investigaciones en Optica, Guanajuato (Mexico); Bysakh, Sandip [Electron Microscopic Section, Material Characterization Division, CSIR-Central Glass and Ceramic Research Institute, Kolkata (India)

    2015-08-15

    The basic material and optical properties of chromium-doped nanophase-separated yttria-alumina-silica (YAS) glass based optical preforms and fibers, fabricated through the modified chemical vapor deposition process in conjunction with solution doping technique under suitable thermal annealing conditions are reported. The size of the phase-separated particles within the core of the annealed preform is around 20-30 nm which is significantly reduced to around 5.0 nm in the drawn fiber. The absorption spectra of fibers drawn from the annealed and non-annealed preform samples revealed the presence of Cr{sup 4+}, Cr{sup 3+}, and Cr{sup 6+} specie. Numerically, extinction of absorption drops ∝3-3.5 times for the annealed sample as a result of nano-phase restructuration during annealing process. Intense broadband emission (within 500-800 nm) in case of the annealed preform sample is observed as compared to the non-annealed one and is associated with the presence of Cr{sup 3+} ions in nanostructured environment inside the YAS core glass. The final fibers show broadband emission ranging from 900 to 1400 nm under pumping at 1064 nm which is attributed mainly to the presence of Cr{sup 3+}/Cr{sup 4+} ions. The fabricated fibers seem to be a potential candidate for the development of fiber laser sources for the visible and near-infra ranges and for effective Q-switching units for ∝1-1.1 μm all-fiber ytterbium lasers. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Theoretical study on separate sensible and latent cooling air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Jiazhen; Hwang, Yunho; Radermacher, Reinhard [Center for Environmental Energy Engineering, Department of Mechanical Engineering, University of Maryland, 3163 Glenn Martin Hall Bldg., College Park, MD 20742 (United States)

    2010-05-15

    The advantage of separating sensible and latent cooling (SSLC) via the use of separate cycles is saving energy by raising the evaporating temperature of the sensible cooling process. In this study, the pertinent characteristics of the SSLC system using two parallel vapor compression cycles were investigated. The requirement for high air flow rate through the sensible evaporator was the most important hardware design issue, since it might lead to a high air-side pressure drop. To address this issue, a new air distribution method, which could significantly reduce the pressure drop, was proposed to replace the conventional one. The heat exchanger modeling results demonstrated that sensible evaporators of the SSLC system could provide the equivalent cooling capacity at reduced air-side pressure drop to that of the conventional system without increasing the total heat transfer area. Although initial investment of the SSLC system is projected to be higher than the conventional system, the estimated operating cost of the SSLC system is lower than the conventional one because of the low energy consumption. (author)

  7. Comparative study of separated fermentations and cofermentation processes to produce ethanol from hardwood derived hydrolysates

    Energy Technology Data Exchange (ETDEWEB)

    Delgenes, J.P.; Laplace, J.M.; Moletta, R. [Institut National de la Recherche Agronomique, Narbonne (France). Lab. de Biotechnologie de l`Environnement; Navarro, J.M. [Montpellier-2 Univ., 34 (France)

    1996-12-31

    As a part of the alcoholic conversion of lignocellulosic sugars, the co-culture process was studied in continuous conditions using a medium resulting from complete hydrolysis of aspen wood and compared with the separated fermentations process performing continuously on hemicellulosic and cellulosic aspen wood derived hydrolysates. The complete conversion of mixture of glucose and xylose was obtained using a respiratory deficient mutant of Saccharomyces diastaticus cocultivated with Pichia stipitis in continuous culture. At the dilution rate of 0.125 h{sup -1}, ethanol (13.5 g 1{sup -1}) was produced with a yield of 0.25 g g{sup -1}, a volumetric productivity of 1.6 g 1{sup -1} h{sup -1} and a substrate conversion rate of 100%. In the separated fermentations scheme, ethanol (39 g 1{sup -1}) was produced by Zymomonas mobilis from cellulosic hydrolysate with a yield of 0.35 g g{sup -1} and a productivity of 7.8 g 1{sup -1} h{sup -1}, whereas Pichia stipitis grown on hemicellulosic hydrolysate produced ethanol (14 g 1{sup -1}) with a yield of 0.37 g g{sup -1} and a productivity of 0.56 g 1{sup -1} h{sup -1}. (Author)

  8. Separation dynamics of dense dispersions in laminar pipe flows: An experimental and numerical study

    Science.gov (United States)

    Voulgaropoulos, Victor; Jamshidi, Rashid; Zainal Abidin, M. I. I.; Angeli, Panagiota

    2017-11-01

    The physical mechanisms governing the separation of dense liquid dispersed flows in pipes are not well understood. In this work, both experiments and numerical simulations are performed to investigate these mechanisms. Liquid-liquid dispersions are generated using a static mixer and their evolution is studied along a horizontal pipe (26mm ID) at laminar flow and input dispersed phase volume fractions up to 50%. To conduct optical measurements (PLIF and PIV) in the dense dispersions, the refractive index of both liquids is matched. Measurements are carried out at two axial locations downstream the mixer (15D and 135D, where D is the pipe diameter). Homogeneous dispersions, observed at 15D, segregate at 135D. The packing of the drops results in asymmetric velocity profiles and high slip velocities. The mixture approach is used in the numerical simulations, including gravity and shear-induced diffusion of drops. The predictions on separation and on velocity fields agree well with the experiments. Research funded by Chevron.

  9. Study on the Correlation between Humidity and Material Strains in Separable Micro Humidity Sensor Design.

    Science.gov (United States)

    Chang, Chih-Yuan

    2017-05-08

    Incidents of injuries caused by tiles falling from building exterior walls are frequently reported in Taiwan. Humidity is an influential factor in tile deterioration but it is more difficult to measure the humidity inside a building structure than the humidity in an indoor environment. Therefore, a separable microsensor was developed in this study to measure the humidity of the cement mortar layer with a thickness of 1.5-2 cm inside the external wall of a building. 3D printing technology is used to produce an encapsulation box that can protect the sensor from damage caused by the concrete and cement mortar. The sensor is proven in this study to be capable of measuring temperature and humidity simultaneously and the measurement results are then used to analyze the influence of humidity on external wall tile deterioration.

  10. [Early mother-infant separation and psychosocial development. II. Longitudinal study on 42 subjects].

    Science.gov (United States)

    Domenici, R; Papini, M A

    1988-01-01

    It is the purpose of the present investigation to obtain some information as they can be drown from the activity of our follow-up for premature babies and infants at higher risk. The main objectives of the study were: - to evaluate the aspects of parent's emotional status and parent-infant interaction in the first year of life; - to evaluate possible effects of the early separation on later development of the children. We have observed 42 LBW infants (hospitalized at birth for a period of one-three months) and their parents for 7-8 years. Our study has included: interviews with parents, observation of interaction, clinical examinations, designs. Recurrent interactive patterns have been defined in their peculiarities in the first year of life. Patterns of later psychosocial development are also exposed: they are strictly related to the kind of the precocious interaction.

  11. Study on the Correlation between Humidity and Material Strains in Separable Micro Humidity Sensor Design

    Directory of Open Access Journals (Sweden)

    Chih-Yuan Chang

    2017-05-01

    Full Text Available Incidents of injuries caused by tiles falling from building exterior walls are frequently reported in Taiwan. Humidity is an influential factor in tile deterioration but it is more difficult to measure the humidity inside a building structure than the humidity in an indoor environment. Therefore, a separable microsensor was developed in this study to measure the humidity of the cement mortar layer with a thickness of 1.5–2 cm inside the external wall of a building. 3D printing technology is used to produce an encapsulation box that can protect the sensor from damage caused by the concrete and cement mortar. The sensor is proven in this study to be capable of measuring temperature and humidity simultaneously and the measurement results are then used to analyze the influence of humidity on external wall tile deterioration.

  12. Identification and Characterization of a Peptidoglycan Hydrolase, MurA, of Listeria monocytogenes, a Muramidase Needed for Cell Separation

    OpenAIRE

    Carroll, Shannon A.; Hain, Torsten; Technow, Ulrike; Darji, Ayub; Pashalidis, Philippos; Joseph, Sam W.; Chakraborty, Trinad

    2003-01-01

    A novel cell wall hydrolase encoded by the murA gene of Listeria monocytogenes is reported here. Mature MurA is a 66-kDa cell surface protein that is recognized by the well-characterized L. monocytogenes-specific monoclonal antibody EM-7G1. MurA displays two characteristic features: (i) an N-terminal domain with homology to muramidases from several gram-positive bacterial species and (ii) four copies of a cell wall-anchoring LysM repeat motif present within its C-terminal domain. Purified rec...

  13. Key parameters for behaviour related to source separation of household organic waste: A case study in Hanoi, Vietnam.

    Science.gov (United States)

    Kawai, Kosuke; Huong, Luong Thi Mai

    2017-03-01

    Proper management of food waste, a major component of municipal solid waste (MSW), is needed, especially in developing Asian countries where most MSW is disposed of in landfill sites without any pretreatment. Source separation can contribute to solving problems derived from the disposal of food waste. An organic waste source separation and collection programme has been operated in model areas in Hanoi, Vietnam, since 2007. This study proposed three key parameters (participation rate, proper separation rate and proper discharge rate) for behaviour related to source separation of household organic waste, and monitored the progress of the programme based on the physical composition of household waste sampled from 558 households in model programme areas of Hanoi. The results showed that 13.8% of 558 households separated organic waste, and 33.0% discharged mixed (unseparated) waste improperly. About 41.5% (by weight) of the waste collected as organic waste was contaminated by inorganic waste, and one-third of the waste disposed of as organic waste by separators was inorganic waste. We proposed six hypothetical future household behaviour scenarios to help local officials identify a final or midterm goal for the programme. We also suggested that the city government take further actions to increase the number of people participating in separating organic waste, improve the accuracy of separation and prevent non-separators from discharging mixed waste improperly.

  14. Function spaces and d -separability | Tkachuk | Quaestiones ...

    African Journals Online (AJOL)

    The object of this paper is to study when a function space is d-separable, i.e., has a dense σ-discrete subspace. Several sufficient conditions are obtained for Cp(X) to be d-separable; as an application it is proved that Cp(X) is d-separable for any Corson compact space X. We give a characterization for Cp(X) × Cp(X) to be ...

  15. Morphological and molecular characterization of the metacercaria of Paragonimus caliensis, as a separate species from P. mexicanus in Costa Rica.

    Science.gov (United States)

    Hernández-Chea, Roderico; Jiménez-Rocha, Ana Eugenia; Castro, Ruth; Blair, David; Dolz, Gaby

    2017-04-01

    The trematode Paragonimus mexicanus is the etiological agent of paragonimiasis, a food-borne zoonotic disease in Latin America. This species, as well as Paragonimus caliensis, have been reported from Costa Rica, but it is not known if the two are synonymous. Two types of Paragonimus metacercariae from freshwater pseudothelphusid crabs from several localities in Costa Rica were recognized by light microscopy. Morphologically, these corresponded to descriptions of P. mexicanus and P. caliensis. Metacercariae of the former species lacked a membrane or cyst and their bodies were yellow in color. Those of P. caliensis were contained in a transparent thin cyst and were pink in color. Morphotypes of metacercariae were determined using scanning electron microscopy (SEM). Based on the number and distribution of papillae in the ventral sucker, three morphotypes were found for P. mexicanus and two for P. caliensis. Analysis of DNA sequences (nuclear ribosomal 28S and ITS2 genes, and partial mitochondrial cox1 gene) confirmed the presence of P. mexicanus and provided the first molecular data for P. caliensis. The two species are phylogenetically distinct from each other and distant from the Asian species. The confirmation of P. caliensis as a separate species from P. mexicanus raises several questions about the ecology, biological diversity, and epidemiology of the genus Paragonimus in Costa Rica. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. Effect of UV-ozone treatment on poly(dimethylsiloxane) membranes: surface characterization and gas separation performance.

    Science.gov (United States)

    Fu, Ywu-Jang; Qui, Hsuan-zhi; Liao, Kuo-Sung; Lue, Shingjiang Jessie; Hu, Chien-Chieh; Lee, Kueir-Rarn; Lai, Juin-Yih

    2010-03-16

    A thin SiO(x) selective surface layer was formed on a series of cross-linked poly(dimethylsiloxane) (PDMS) membranes by exposure to ultraviolet light at room temperature in the presence of ozone. The conversion of the cross-linked polysiloxane to SiO(x) was monitored by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray (EDX) microanalysis, contact angle analysis, and atomic force microscopy (AFM). The conversion of the cross-linked polysiloxane to SiO(x) increased with UV-ozone exposure time and cross-linking agent content, and the surface possesses highest conversion. The formation of a SiO(x) layer increased surface roughness, but it decreased water contact angle. Gas permeation measurements on the UV-ozone exposure PDMS membranes documented interesting gas separation properties: the O(2) permeability of the cross-linked PDMS membrane before UV-ozone exposure was 777 barrer, and the O(2)/N(2) selectivity was 1.9; after UV-ozone exposure, the permeability decreased to 127 barrer while the selectivity increased to 5.4. The free volume depth profile of the SiO(x) layer was investigated by novel slow positron beam. The results show that free volume size increased with the depth, yet the degree of siloxane conversion to SiO(x) does not affect the amount of free volume.

  17. Study the influence factors to the adsorption process for separation of polyphenols from green tea

    Science.gov (United States)

    Phung, Lan Huong; Tran, Trung Kien; Van Quyet, Chu; Phi, Nguyen Thien

    2017-09-01

    The objective of this work is applying adsorption process for separation of polyphenols from extract solution of green tea by-product. The older leaves and stem of green tea tree are collected from Hiep Khanh Tea Company (Hoabinh province, Vietnam). In this study, two kinds of adsorbent (silicagel, active carbon) were applied for the adsorption process in batch stirring vessel. The factors that affected to the process productivity were investigated: temperature, solid/liquid ratio, duration time, stirring speed. The process has been empirically described with statistical models obtained by Design of Experiments. The results indicated that active carbon was verified to offer good adsorption productivity (more than 95%), much more effective than silicagel (with only about 20%). From the model, the most affected factor to the process could be seen as solid/liquid ratio.

  18. Event-shape-engineering study of charge separation in heavy-ion collisions

    Science.gov (United States)

    Wen, Fufang; Bryon, Jacob; Wen, Liwen; Wang, Gang

    2018-01-01

    Recent measurements of charge-dependent azimuthal correlations in high-energy heavy-ion collisions have indicated charge-separation signals perpendicular to the reaction plane, and have been related to the chiral magnetic effect (CME). However, the correlation signal is contaminated with the background caused by the collective motion (flow) of the collision system, and an effective approach is needed to remove the flow background from the correlation. We present a method study with simplified Monte Carlo simulations and a multi-phase transport model, and develop a scheme to reveal the true CME signal via event-shape engineering with the flow vector of the particles of interest. Supported by a grant (DE-FG02-88ER40424) from U.S. Department of Energy, Office of Nuclear Physics

  19. Quantifying uncertainties in tracer-based hydrograph separations: a case study for two-, three- and five-component hydrograph separations in a mountainous catchment

    Science.gov (United States)

    Uhlenbrook, Stefan; Hoeg, Simon

    2003-02-01

    The hydrograph separation technique using natural tracers, in which different runoff components are quantified according to their chemical signature, is a widely used method for investigating runoff generation processes at the catchment scale. The first objective of this study is to demonstrate a modified methodology for separating three and five runoff components using 18O and dissolved silica as tracers. The second is to evaluate, with an uncertainty propagation technique using Gaussian error estimators, the hydrograph separation uncertainties that arise due to different error effects.During four summer storm events, an interaction among three main runoff components having distinct dissolved silica concentrations was demonstrated for the mountainous Zastler catchment (18·4 km2, southern Black Forest Mountains, southwest Germany). The three main runoff components are surface storage (low silica, saturated and impermeable areas), shallow ground water (medium silica, periglacial and glacial drift cover), and deep ground water (high silica, crystalline detritus and hard rock aquifer). Together with the event and pre-event water fractions of surface runoff and shallow ground water runoff, five runoff components are considered in all. Pre-event water from shallow ground water storage dominated the total discharge during floods and was also important during low flows. Event water from shallow ground water was detectable only during the falling limb of a larger flood with high antecedent moisture conditions and during the peaks of three events with low antecedent moisture conditions. Runoff from surface storage is only significant during floods and can be composed of event and pre-event water. The latter reacts later and is important only during the peak of the large event with high antecedent moisture conditions. Runoff from the deeper ground water behaves quite consistently (pure pre-event water).It is demonstrated that large relative uncertainties must be considered

  20. Study of the coefficient of separation for some processes which are applied to lithium isotopes; Etude du coefficient de separation de quelques processus concernant les isotopes du lithium

    Energy Technology Data Exchange (ETDEWEB)

    Perret, L.; Rozand, L.; Saito, E. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The fundamental separation factors of some processes are investigated: the distillation of metallic lithium, counter current electromigration in fused salts (particularly in lithium nitrate) electrolysis in aqueous solution and ion exchange. The chemical transfer between a lithium amalgam and lithium salts in a dimethylformamide solution (a solvent which is not attacked by the amalgam) is also studied. Finally a description is given of isotopic analyses carried out either by scintillation counting or by mass spectrography using apparatus specially designed for this particular task. (author) [French] Les facteurs de separation elementaires de quelques processus connus sont etudies: distillation du lithium metallique, electromigration a contre-courant en sels fondus (en particulier le nitrate), electrolyse en solution aqueuse et echange d'ions. L'echange chimique entre l'amalgame de lithium et les sels de lithium en solution dans la dimethylformamide - solvant non attaque par l'amalgame - est egalement etudie. Enfin, on decrit les methodes d 'analyse isotopique, soit par comptage par scintillation, soit par spectrometrie de masse au moyen d'un appareil specialement concu pour cet usage particulier. (auteur)

  1. Partition separation and characterization of the polyhydroxyalkanoates synthase produced from recombinant Escherichia coli using an aqueous two-phase system.

    Science.gov (United States)

    Lan, John Chi-Wei; Yeh, Chun-Yi; Wang, Chih-Chi; Yang, Yu-Hsuan; Wu, Ho-Shing

    2013-10-01

    Polyhydroxyalkanoates (PHAs) are renewable and biodegradable polyesters which can be synthesized either by numerous of microorganisms in vivo or synthase in vitro. The synthesis of PHAs in vitro requires an efficient separation for high yield of purified enzyme. The recombinant Escherichia coli harboring phaC gene derived from Ralstonia eutropha H16 was cultivated in the chemically defined medium for overexpression of synthase in the present work. The purification and characteristics of PHA synthase from clarified feedstock by using aqueous two-phase systems (ATPS) was investigated. The optimized concentration of ATPS for partitioning PHA synthase contained polyethylene glycol 6000 (30%, w/w) and potassium phosphate (8%, w/w) with 3.25 volume ratio in the absence of NaCl at pH 8.7 and 4°C. The results showed that the partition coefficient of enzyme activity and protein content are 6.07 and 0.22, respectively. The specific activity, selectivity, purification fold and recovery of phaC(Re) achieved 1.76 U mg⁻¹, 29.05, 16.23 and 95.32%, respectively. Several metal ions demonstrated a significant effect on activity of purified enzyme. The purified enzyme displayed maximum relative activity as operating condition at pH value of 7.5 and 37°C. As compared to conventional purification processes, ATPS can be a promising technique applied for rapid recovery of PHA synthase and preparation of large quantity of PHA synthase on synthesis of P(3HB) in vitro. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  2. Development and characterization of a metallic substrat for nanostructured membranes in the separation of gas mixtures; Entwicklung und Charakterisierung eines metallischen Substrats fuer nanostrukturierte Gastrennmembranen

    Energy Technology Data Exchange (ETDEWEB)

    Brands, Katharina

    2010-07-01

    In order to minimize the further increase of CO{sub 2}-content in the atmosphere, efforts are made to separate and store CO{sub 2} from exhaust gases of fossil power plants. Beside well-established separation techniques like chemical scrubber, the application of membrane technology is intensively investigated. One focus of this thesis is the development of metal supported substrates for microporous ceramic gas separation membranes, which are expected to have a higher mechanical stability than ceramic supported substrates. Starting with commercial porous steel substrates, interlayers are applied by wet powder spraying. For the interlayers the materials 1.4404-stainless steel and TiO{sub 2} or 1.4845-stainless steel and yttria stabilized zirconia (8YSZ) are chosen. The interlayers have to be defect-free, as minimal defects can deteriorate the membrane performance. By a subsequent mechanical treatment and an adjustment of the viscosity of the 8YSZ-suspension, the surface quality is considerably increased. At the same time the limits of the wet powder spraying process become obvious, as sporadic agglomerates, which are formed during the spraying process, cannot be totally avoided. The metal supported substrates are characterized regarding to the interaction between steel and ceramic, the roughness of the layers compared to polished ceramic substrates, the mechanical properties and the flow through the substrates. Furthermore microporous ceramic gas separation membranes are deposited on wet powder sprayed and dip coated substrates. The selectivity of these membranes is above Knudsen selectivity. The other focus of the thesis is the exposure of substrates and membranes to real flue gas conditions. Beside microporous ceramic membranes polymer membranes are analysed as a reference, which show a higher state of development compared to microporous ceramic membranes. For this purpose a test bed is built up in the EnBW ''Rheinhafendampfkraftwerk RDK 7&apos

  3. Hybrid Enrichment Verification Array: Module Characterization Studies

    Energy Technology Data Exchange (ETDEWEB)

    Zalavadia, Mital A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Smith, Leon E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McDonald, Benjamin S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kulisek, Jonathan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mace, Emily K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Deshmukh, Nikhil S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    The work presented in this report is focused on the characterization and refinement of the Hybrid Enrichment Verification Array (HEVA) approach, which combines the traditional 186-keV 235U signature with high-energy prompt gamma rays from neutron capture in the detector and surrounding collimator material, to determine the relative enrichment and 235U mass of the cylinder. The design of the HEVA modules (hardware and software) deployed in the current field trial builds on over seven years of study and evolution by PNNL, and consists of a ø3''×3'' NaI(Tl) scintillator coupled to an Osprey digital multi-channel analyzer tube base from Canberra. The core of the HEVA methodology, the high-energy prompt gamma-ray signature, serves as an indirect method for the measurement of total neutron emission from the cylinder. A method for measuring the intrinsic efficiency of this “non-traditional” neutron signature and the results from a benchmark experiment are presented. Also discussed are potential perturbing effects on the non-traditional signature, including short-lived activation of materials in the HEVA module. Modeling and empirical results are presented to demonstrate that such effects are expected to be negligible for the envisioned implementation scenario. In comparison to previous versions, the new design boosts the high-energy prompt gamma-ray signature, provides more flexible and effective collimation, and improves count-rate management via commercially available pulse-processing electronics with a special modification prompted by PNNL.

  4. THE STUDY OF BRAKE EFFECTIVENESS HOPPER SYSTEM WITH SEPARATE BRAKING TRUCKS

    Directory of Open Access Journals (Sweden)

    O. Je. Nishhenko

    2009-06-01

    Full Text Available The results of tests of the hopper brake systems for the pellets having typical system and separate braking per each bogie are presented. It is shown that the brake system with separate braking has several advantages as compared to the typical one.

  5. Cramér-Rao Bound Study of Multiple Scattering Effects in Target Separation Estimation

    Directory of Open Access Journals (Sweden)

    Edwin A. Marengo

    2013-01-01

    Full Text Available The information about the distance of separation between two-point targets that is contained in scattering data is explored in the context of the scalar Helmholtz operator via the Fisher information and associated Cramér-Rao bound (CRB relevant to unbiased target separation estimation. The CRB results are obtained for the exact multiple scattering model and, for reference, also for the single scattering or Born approximation model applicable to weak scatterers. The effects of the sensing configuration and the scattering parameters in target separation estimation are analyzed. Conditions under which the targets' separation cannot be estimated are discussed for both models. Conditions for multiple scattering to be useful or detrimental to target separation estimation are discussed and illustrated.

  6. Spatial characterization of hot melt extruded dispersion systems using thermal atomic force microscopy methods: the effects of processing parameters on phase separation.

    Science.gov (United States)

    Moffat, Jonathan G; Qi, Sheng; Craig, Duncan Q M

    2014-07-01

    In this study we explore the use of nano-scale localized thermal analysis (LTA) and transition temperature microcopy (TTM) as a novel combined approach to studying phase separation in HME dispersions of cyclosporine A in Eudragit EPO. Modulated temperature differential scanning calorimetry (MTDSC), attenuated total reflectance FTIR spectroscopy, nano-LTA and TTM were performed on raw materials and dispersions prepared by hot melt extrusion (HME) and spin coating. For samples prepared by HME, two mixing temperatures (110°C and 150°C) and residence times (5 and 15 min) were investigated. Spin coated samples showed an intermediate T g for the mixed systems consistent with molecular dispersion formation. The HME samples prepared at 110°C showed evidence of inhomogeneity using MTDSC and FTIR, while those produced at 150°C h showed evidence for the formation of a single phase system using MTDSC. The nanothermal methods, however, indicated the presence of phase separated cyclosporine A at the higher preparation temperature while the TTM was able to map regions of differing penetration temperatures, indicating the presence of compositionally inhomogeneous regions in all but the high processing temperature/high residence time samples. TTM is a potentially important new method for studying phase separation and that such separation may remain undetected or poorly understood using conventional bulk analytical techniques.

  7. Separate disciplines: The study of behavior and the study of the psyche.

    Science.gov (United States)

    Fraley, L E; Vargas, E A

    1986-01-01

    The study of behavior differs fundamentally from the study of the psyche and logically cannot share the same discipline. However, while disciplines might be defined through technical exercises, they function through exercises of political power. The evolution of a discipline, though based on field and laboratory data interpreted within a specific paradigm and justified publicity by its utility to solve personal and social problems, follows a course of development in the political arenas of the academies and the professions. We happen to have a discipline, roughly connoted by the label "behavior analysis," without an academic home (the present ones haphazardly tolerate our activities), without a professional organization (the present one lobbies only "for behavior analysis"), and without a true professional name (the present one implies an approach not a discipline). No scientific community lasts long without a supporting professional infrastructure. In explicitly asserting ourselves as a discipline, we confront a number of difficult issues such as continuing to work in departments antithetical to behaviorism and a number of problems such as what we call ourselves to identify our professional and scientific concerns. (For example, we need a term descriptive of our science in its broad sense. That term is not psychology. Too many people persist in maintaining its commitment to cognitivism. On whatever term we agree, "behavior" should constitute its stem, for our efforts focus there, not in the putative underlying psyche or its current cognitive update.) The focus of our concerns and the solutions of our problems rest on one issue: Will our discipline prosper most as a branch of psychology or as an independent discipline? Slowly, but surely, our actions demonstrate that the latter is the preferred option, but these actions, though fortuitous, occur almost by accident. By specifically programming to achieve an independent professional status we increase the probability

  8. Synthesis, characterization and conductivity studies of polypyrrole ...

    Indian Academy of Sciences (India)

    The polypyrrole–fly ash composites were also characterized by employing X-ray diffractometry (XRD) and infrared spectroscopy (IR). ... Department of Physics, GM Institute of Technology, Davangere 577 006, India; Department of Physics, KBN College of Engineering, Gulbarga 585 104, India; Department of Materials ...

  9. Visualized study on the interaction between single bubbles and curved solid surface in flotation separation process.

    Science.gov (United States)

    Yang, Liwei; Zhao, Yue; Yang, Jingjing; Li, Yanpeng; Meng, Qinglong

    2014-01-01

    The present study has been devoted to bubble-curved solid surface interaction in water, which is critical to the separation of suspended particles by air flotation. For this purpose, two particular stages of the interaction (collision and attachment) have been examined visually using high-speed photography in a laboratory-scale flotation column. The effects of the surface material and surfactant concentration on these two stages have been also studied quantitatively. The considered solid materials are the cleaned glass as hydrophilic surface and Teflon as hydrophobic surface. The experimental results show that the presence of surfactant significantly affects the collision and rebound process of a gas bubble, while there is no obvious effect of the surface material on the rebound process. An increase in surfactant concentration has been observed to suppress the rebound number and maximal distance of the bubble from the surface. Moreover, the three-phase contact time of the bubble is a strong function of the surfactant concentration and surface hydrophobicity as well as of the bubble diameter. Another important finding is that the bubble attachment is only observed at the hydrophobic Teflon surface below the surfactant CMC (critical micelle concentration). Results of this study are relevant for deep understanding of the attachment mechanism and to determine the proper conditions for a selective flotation process.

  10. A design study of hydrogen isotope separation system for ITER-FEAT

    Energy Technology Data Exchange (ETDEWEB)

    Iwai, Yasunori; Yamanishi, Toshihiko; Nishi, Masataka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-03-01

    Preliminary design study of the hydrogen isotope separation system (ISS) for the fuel cycle of the ITER-FEAT, a fusion experimental reactor, was carried out based on the substantial reduction of hydrogen flow to the ISS resulting from the design study for scale reduction of the formerly-designed ITER. Three feed streams (plasma exhaust gas stream, streams from the water detritiation system and that from the neutral beam injectors) are fed to the ISS, and three product streams (high purity tritium gas, high purity deuterium gas and hydrogen gas) are made in it by the method of cryogenic distillation. In this study, an original four-column cascade was proposed to the ISS cryogenic distillation column system considering simplification and the operation scenario of the ITER-FEAT. Substantial reduction of tritium inventory in the ISS was found to be possible in the progress of investigation concerning of the corresponding flow rate of tritium product stream (T>90 %) for pellet injector which depends upon the operation condition. And it was found that tritium concentration in the released hydrogen stream into environment from the ISS could easily fluctuate with current design of column arrangement due to the small disturbance in mass flow balance in the ISS. To solve this problem, two-column system for treatment of this flow was proposed. (author)

  11. Nonterminal Separating Macro Grammars

    NARCIS (Netherlands)

    Hogendorp, Jan Anne

    1987-01-01

    We extend the concept of nonterminal separating (or NTS) context-free grammar to nonterminal separating $m$-macro grammar where the mode of derivation $m$ is equal to "unrestricted". "outside-in' or "inside-out". Then we show some (partial) characterization results for these NTS $m$-macro grammars.

  12. Structure and function of an inorganic-organic separator for electrochemical cells: Preliminary study

    Science.gov (United States)

    Bozek, J. M.

    1974-01-01

    The structure of a new separator material for electrochemical cells has been investigated. Investigation into details of the separator structure showed it to be multilayered and to consist mainly of a quasi-impervious organic skin, a porous region of mixed organic and inorganic material, and an area of nonuniformly treated substrate. The essential feature of the coating (slurry) is believed to be interconnected pores which allow ionic conductivity. The interconnected pores are believed to be formed by the interaction of the plasticizer and inorganic fibers. The major failure mode of silver zinc cells using such a separator (zinc nodules shorting adjacent plates) was investigated.

  13. Neurophysiological characterization of subacute stroke patients: a longitudinal study

    Directory of Open Access Journals (Sweden)

    Giuseppe Lamola

    2016-11-01

    Full Text Available Various degrees of neural reorganization may occur in affected and unaffected hemispheres in the early phase after stroke and several months later. Recent literature suggests to apply a stratification based on lesion location and to consider patients with cortico-subcortical and subcortical strokes separately: different lesion location may also influence therapeutic response. In this study we used a longitudinal approach to perform TMS assessment (Motor Evoked Potentials, MEP, and Silent Period, SP and clinical evaluations (Barthel Index, Fugl-Meyer Assessment for upper limb motor function and Wolf Motor Function Test in 10 cortical-subcortical and 10 subcortical ischemic stroke patients. Evaluations were performed in a window between 10 and 45 days (t0 and at 3 months after the acute event (t1. Our main finding is that 3 months after the acute event patients affected by subcortical stroke presented a reduction in contralateral SP duration in the unaffected hemisphere; this trend is related to clinical improvement of upper limb motor function. In conclusion, SP proved to be a valid parameter to characterize cortical reorganization patterns in stroke survivors and provided useful information about motor recovery within three months in subcortical patients.

  14. Design, synthesis, characterization and study of novel conjugated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Wu [Iowa State Univ., Ames, IA (United States)

    1997-06-24

    After introducing the subject of conjugated polymers, the thesis has three sections each containing a literature survey, results and discussion, conclusions, and experimental methods on the following: synthesis, characterization of electroluminescent polymers containing conjugated aryl, olefinic, thiophene and acetylenic units and their studies for use in light-emitting diodes; synthesis, characterization and study of conjugated polymers containing silole unit in the main chain; and synthesis, characterization and study of silicon-bridged and butadiene-linked polythiophenes.

  15. Separated Shoulder

    Science.gov (United States)

    ... an injury to the ligaments that hold your collarbone (clavicle) to your shoulder blade. In a mild separated ... tenderness or pain near the end of your collarbone. Causes The most common cause of a separated ...

  16. Rapid chemical separations

    CERN Document Server

    Trautmann, N

    1976-01-01

    A survey is given on the progress of fast chemical separation procedures during the last few years. Fast, discontinuous separation techniques are illustrated by a procedure for niobium. The use of such techniques for the chemical characterization of the heaviest known elements is described. Other rapid separation methods from aqueous solutions are summarized. The application of the high speed liquid chromatography to the separation of chemically similar elements is outlined. The use of the gas jet recoil transport method for nuclear reaction products and its combination with a continuous solvent extraction technique and with a thermochromatographic separation is presented. Different separation methods in the gas phase are briefly discussed and the attachment of a thermochromatographic technique to an on-line mass separator is shown. (45 refs).

  17. A Study on the Performance of the Saffron Separator for Different Air Flows

    OpenAIRE

    Abbas Moghanizadeh; Mehdi Neshat

    2014-01-01

    Saffron, the dried stigmas of Crocus sativus, is extremely appreciated for its extraordinary color, taste and aroma. At the present time, nearly all the saffron harvest and post harvest processes are carried out manually. To increase the quality and development of economic role of saffron, it is essential to go beyond the traditional method of harvest of saffron. Considering that saffron components terminal velocities are different, a separator is planned and constructed to separate stigma fr...

  18. Molecular simulation studies of gas adsorption and separation in metalorganic frameworks

    OpenAIRE

    Zoroufchian Moghadam, Peyman; Moghadam, Peyman Zoroufchian

    2013-01-01

    Adsorption in porous materials plays a significant role in industrial separation processes. Here, the host-guest interaction and the pore shape influence the distribution of products. Metal-organic frameworks (MOFs) are promising materials for separation purposes as their diversity due to their building block synthesis from metal corners and organic linker gives rise to a wide range of porous structures. The selectivity differs from MOF to MOF as the size and shapes of their po...

  19. Structural and conformational variants of human beta2-microglobulin characterized by capillary electrophoresis and complementary separation methods

    DEFF Research Database (Denmark)

    Heegaard, Niels H H; Rovatti, Luca; Nissen, Mogens H

    2003-01-01

    and normal (i.e. nonoxidized) beta2-microglobulin behave similarly with respect to the potential to attain this alternative conformation. CE is an attractive method to study early and intermediate soluble folding variants that may be involved in PCDs and CE thus may have an important role as a tool...

  20. Percutaneous dual-switching monopolar radiofrequency ablation using a separable clustered electrode: A preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Tae Won; Lee, Jeong Min; Lee, Dong Ho; Lee, Jeong Hoon; Yu, Su Jong; Kim, Yoon Jun; Yoon, Jung Hwan; Han, Joon Koo [Seoul National University Hospital, Seoul (Korea, Republic of)

    2017-09-15

    To prospectively evaluate the safety and therapeutic effectiveness of dual-switching monopolar (DSM) radiofrequency ablation (RFA) for the treatment of hepatocellular carcinoma (HCC), and to retrospectively compare the results with those of single-switching monopolar (SSM) RFA in a historical control group. This study was approved by the Institutional Review Board, with informed consent obtained from all patients. Fifty-two HCC patients who underwent DSM-RFA using a separable clustered electrode and dual-generators were prospectively enrolled. Technical parameters, complications, technical success, technical effectiveness, and local tumor progression (LTP) rates were evaluated by means of post-procedural and follow-up imaging. Thereafter, the outcome of DSM-RFA was compared with those of 249 retrospectively included HCC patients treated with SSM-RFA.There were two major complications (3.8%, 2/52) including pleural and pericardial effusion in the DSM-RFA group. The DSM-RFA yielded a 100% technical success rate, a 98.1% technical effectiveness rate, and a 4.3% 2-year LTP rate. In a retrospective comparison between the two groups, DSM-RFA created significantly larger ablation volume (4.20 ± 2.07 cm{sup 3}/min vs. 3.03 ± 1.99 cm{sup 3}/min, p < 0.01), and delivered higher energy (1.43 ± 0.37 kcal/min vs. 1.25 ± 0.50 kcal/min, p < 0.01) per given time, than SSM-RFA. There was no significant difference in major procedure-related complications (3.8% vs. 4.4%) and technical effectiveness rate (98.1% vs. 96.4%) between the two groups (p = 1.00). In addition, the 2-year LTP rate of DSM-RFA and SSM-RFA were 4.3% and 10.1%, respectively (p = 0.15). DSM-RFA using a separable clustered electrode is safe and provides high local tumor control and good preliminary clinical outcome for small HCCs, which are at least comparable to those of SSM-RFA.

  1. Maternal separation affects dopamine transporter function in the Spontaneously Hypertensive Rat: An in vivo electrochemical study

    Directory of Open Access Journals (Sweden)

    Womersley Jacqueline S

    2011-12-01

    Full Text Available Abstract Background Attention-deficit/hyperactivity disorder (ADHD is a developmental disorder characterised by symptoms of inattention, impulsivity and hyperactivity. The spontaneously hypertensive rat (SHR is a well-characterised model of this disorder and has been shown to exhibit dopamine dysregulation, one of the hypothesised causes of ADHD. Since stress experienced in the early stages of life can have long-lasting effects on behaviour, it was considered that early life stress may alter development of the dopaminergic system and thereby contribute to the behavioural characteristics of SHR. It was hypothesized that maternal separation would alter dopamine regulation by the transporter (DAT in ways that distinguish SHR from control rat strains. Methods SHR and control Wistar-Kyoto (WKY rats were subjected to maternal separation for 3 hours per day from postnatal day 2 to 14. Rats were tested for separation-induced anxiety-like behaviour followed by in vivo chronoamperometry to determine whether changes had occurred in striatal clearance of dopamine by DAT. The rate of disappearance of ejected dopamine was used as a measure of DAT function. Results Consistent with a model for ADHD, SHR were more active than WKY in the open field. SHR entered the inner zone more frequently and covered a significantly greater distance than WKY. Maternal separation increased the time that WKY spent in the closed arms and latency to enter the open arms of the elevated plus maze, consistent with other rat strains. Of note is that, maternal separation failed to produce anxiety-like behaviour in SHR. Analysis of the chronoamperometric data revealed that there was no difference in DAT function in the striatum of non-separated SHR and WKY. Maternal separation decreased the rate of dopamine clearance (k-1 in SHR striatum. Consistent with this observation, the dopamine clearance time (T100 was increased in SHR. These results suggest that the chronic mild stress of

  2. 40 CFR 160.135 - Physical and chemical characterization studies.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Physical and chemical characterization studies. 160.135 Section 160.135 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of a Study § 160.135 Physical and chemical characterization studie...

  3. Growth, characterization, and application of well-defined separated GaN-based pyramid array on micropatterned sapphire substrate

    Science.gov (United States)

    Tian, Zhenhuan; Li, Yufeng; Su, Xilin; Feng, Lungang; Wang, Shuai; Zhang, Minyan; Ding, Wen; Li, Qiang; Zhang, Ye; Guo, Maofeng; Yun, Feng; Lee, S. W. Ricky

    2017-09-01

    We tried to obtain microstructures on a three-dimensional (3D) micropatterned substrate by laser drilling. The influences of the dimensions of the drilling holes on the morphology and the material quality of the grown structures were studied. Uniform micropyramid arrays with relatively low dislocation density can be achieved by adjusting the laser drilling parameters. The internal quantum efficiency was estimated to be improved by a factor of 3 for a pyramid structure compared with that of planar LEDs. We fabricated 5 × 7 mm2 flexible LEDs employing the pyramid structure and the devices exhibited good flexibility without performance reduction after bending.

  4. Physical Separation in the Workplace

    DEFF Research Database (Denmark)

    Stea, Diego; Foss, Nicolai Juul; Holdt Christensen, Peter

    2015-01-01

    Physical separation is pervasive in organizations, and has powerful effects on employee motivation and organizational behaviors. However, research shows that workplace separation is characterized by a variety of tradeoffs, tensions, and challenges that lead to both positive and negative outcomes....

  5. Plasma characterization studies for materials processing

    Energy Technology Data Exchange (ETDEWEB)

    Pfender, E.; Heberlein, J. [Univ. of Minnesota, Minneapolis, MN (United States)

    1995-12-31

    New applications for plasma processing of materials require a more detailed understanding of the fundamental processes occurring in the processing reactors. We have developed reactors offering specific advantages for materials processing, and we are using modeling and diagnostic techniques for the characterization of these reactors. The emphasis is in part set by the interest shown by industry pursuing specific plasma processing applications. In this paper we report on the modeling of radio frequency plasma reactors for use in materials synthesis, and on the characterization of the high rate diamond deposition process using liquid precursors. In the radio frequency plasma torch model, the influence of specific design changes such as the location of the excitation coil on the enthalpy flow distribution is investigated for oxygen and air as plasma gases. The diamond deposition with liquid precursors has identified the efficient mass transport in form of liquid droplets into the boundary layer as responsible for high growth, and the chemical properties of the liquid for the film morphology.

  6. Performance of Reynolds Averaged Navier-Stokes Models in Predicting Separated Flows: Study of the Hump Flow Model Problem

    Science.gov (United States)

    Cappelli, Daniele; Mansour, Nagi N.

    2012-01-01

    Separation can be seen in most aerodynamic flows, but accurate prediction of separated flows is still a challenging problem for computational fluid dynamics (CFD) tools. The behavior of several Reynolds Averaged Navier-Stokes (RANS) models in predicting the separated ow over a wall-mounted hump is studied. The strengths and weaknesses of the most popular RANS models (Spalart-Allmaras, k-epsilon, k-omega, k-omega-SST) are evaluated using the open source software OpenFOAM. The hump ow modeled in this work has been documented in the 2004 CFD Validation Workshop on Synthetic Jets and Turbulent Separation Control. Only the baseline case is treated; the slot flow control cases are not considered in this paper. Particular attention is given to predicting the size of the recirculation bubble, the position of the reattachment point, and the velocity profiles downstream of the hump.

  7. Synthesis and Characterization of a Novel Microporous Dihydroxyl-Functionalized Triptycene-Diamine-Based Polyimide for Natural Gas Membrane Separation.

    Science.gov (United States)

    Alaslai, Nasser; Ma, Xiaohua; Ghanem, Bader; Wang, Yingge; Alghunaimi, Fahd; Pinnau, Ingo

    2017-09-01

    An intrinsically microporous polyimide is synthesized in m-cresol by a one-pot high-temperature condensation reaction of 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and newly designed 2,6 (7)-dihydroxy-3,7(6)-diaminotriptycene (DAT1-OH). The 6FDA-DAT1-OH polyimide is thermally stable up to 440 °C, shows excellent solubility in polar solvents, and has moderately high Brunauer-Teller-Emmett (BET) surface area of 160 m 2 g -1 , as determined by nitrogen adsorption at -196 °C. Hydroxyl functionalization applied to the rigid 3D triptycene-based diamine building block results in a polyimide that exhibits moderate pure-gas CO 2 permeability of 70 Barrer combined with high CO 2 /CH 4 selectivity of 50. Mixed-gas permeation studies demonstrate excellent plasticization resistance of 6FDA-DAT1-OH with impressive performance as potential membrane material for natural gas sweetening with a CO 2 permeability of 50 Barrer and CO 2 /CH 4 selectivity of 40 at a typical natural gas well partial pressure of 10 atm. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Synthesis and Characterization of a Novel Microporous Dihydroxyl-Functionalized Triptycene-Diamine-Based Polyimide for Natural Gas Membrane Separation

    KAUST Repository

    Alaslai, Nasser Y.

    2017-07-10

    An intrinsically microporous polyimide is synthesized in m-cresol by a one-pot high-temperature condensation reaction of 4,4\\'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and newly designed 2,6 (7)-dihydroxy-3,7(6)-diaminotriptycene (DAT1-OH). The 6FDA-DAT1-OH polyimide is thermally stable up to 440 °C, shows excellent solubility in polar solvents, and has moderately high Brunauer-Teller-Emmett (BET) surface area of 160 m2 g-1 , as determined by nitrogen adsorption at -196 °C. Hydroxyl functionalization applied to the rigid 3D triptycene-based diamine building block results in a polyimide that exhibits moderate pure-gas CO2 permeability of 70 Barrer combined with high CO2 /CH4 selectivity of 50. Mixed-gas permeation studies demonstrate excellent plasticization resistance of 6FDA-DAT1-OH with impressive performance as potential membrane material for natural gas sweetening with a CO2 permeability of 50 Barrer and CO2 /CH4 selectivity of 40 at a typical natural gas well partial pressure of 10 atm.

  9. Adsorption and separation of n/iso-pentane on zeolites: A GCMC study.

    Science.gov (United States)

    Fu, Hui; Qin, Hansong; Wang, Yajun; Liu, Yibin; Yang, Chaohe; Shan, Honghong

    2017-12-06

    Separation of branched chain hydrocarbons and straight chain hydrocarbons is very important in the isomerization process. Grand canonical ensemble Monte Carlo simulations were used to investigate the adsorption and separation of iso-pentane and n-pentane in four types of zeolites: MWW, BOG, MFI, and LTA. The computation of the pure components indicates that the adsorption capacity is affected by physical properties of zeolite, like pore size and structures, and isosteric heat. In BOG, MFI and LTA, the amount of adsorption of n-pentane is higher than iso-pentane, while the phenomenon is contrary in MWW. For a given zeolite, a stronger adsorption heat corresponds to a higher loading. In the binary mixture simulations, the separation capacity of n-and iso-pentane increases with the elevated pressure and the increasing iso-pentane composition. The adsorption mechanism and competition process have been examined. Preferential adsorption contributions prevail at low pressure, however, the size effect becomes important with the increasing pressure, and the relatively smaller n-pentane gradually competes successfully in binary adsorption. Among these zeolites, MFI has the best separation performance due to its high shape selectivity. This work helps to better understand the adsorption and separation performance of n- and iso-pentane in different zeolites and explain the relationship between zeolite structures and adsorption performance. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Study on selective separation of uranium by N,N-dialkyl-amide in ARTIST process

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, S.; Sasaki, Y.; Yaita, T.; Kimura, T

    2004-07-01

    An innovative chemical separation process (ARTIST: Amide-based Radio-resources Treatment with Interim Storage of Transuranics) was proposed for the treatment of spent nuclear fuel. The main concept of ARTIST process is to recover and stock all actinides (An) and to dispose the fission products (FP). One of the main purposes of this process is selective isolation of uranium. Since the branched alkyl type N,N-dialkyl-monoamides (BAMA) have the steric hindrance on the complexation with metal cations, BAMA can be used to separate An(VI) from An(IV). N,N-di-(2-ethyl)hexyl-2,2-dimethyl-propanamide (D2EHDMPA) can recover U(VI) selectively without accumulating Pu(IV) in uranium isolation process. From extraction behavior of Np, D2EHDMPA can extract and separate U(VI) from Np(VI) without reduction from Np(VI) to Np(V) or Np(IV). (authors)

  11. Evidence for confinement induced phase separation in ethanol–water mixture: a positron annihilation study

    Science.gov (United States)

    Muthulakshmi, T.; Dutta, D.; Maheshwari, Priya; Pujari, P. K.

    2018-01-01

    We report an experimental evidence for the phase separation of ethanol–water mixture confined in mesoporous silica with different pore size using positron annihilation lifetime spectroscopy (PALS). A bulk-like liquid in the core of the pore and a distinct interfacial region near the pore surface have been identified based on ortho-positronium lifetime components. The lifetime corresponding to the core liquid shows similar behavior to the bulk liquid mixture while the interfacial lifetime shows an abrupt rise within a particular range of ethanol concentration depending on the pore size. This abrupt increase is attributed to the appearance of excess free-volume near the interfacial region. The excess free-volume is originated due to microphase separation of confined ethanol–water primarily at the vicinity of the pore wall. We envisage that probing free-volume changes at the interface using PALS is a sensitive way to investigate microphase separation under nanoconfinement.

  12. Study of the separation limits of continuous solid support free liquid-liquid chromatography: separation of capsaicin and dihydrocapsaicin by centrifugal partition chromatography.

    Science.gov (United States)

    Goll, Johannes; Frey, Andreas; Minceva, Mirjana

    2013-04-05

    Sequential centrifugal partition chromatography (sCPC) is a cyclic solid support-free liquid-liquid chromatographic process, in which a continuously introduced feed mixture is separated into two sequentially collected product streams. The few experimental demonstrations of this concept already revealed its potential for the preparative separation of pharmaceuticals and fine chemicals. In this work not only the possibilities, but also the limits of the sCPC technology are explored. A feed mixture consisting of capsaicin and dihydrocapsaicin, whose molecular structure differs in only one double bond, was selected for this purpose. The sCPC unit operating parameters needed for a complete separation of the feed mixture were selected using the recently published approach, which uses the partition coefficient of the feed components and the hydrodynamic characteristics of the system as input data. A complete separation of capsaicin and dihydrocapsaicin with the solvent system heptane/ethyl acetate/methanol/water:1/1/1/1 (v/v/v/v) was achieved, although the separation factor was only 1.32. The sCPC unit separation performance was successfully simulated using the cell model. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Study on the hydrocyclonic separation of waste plastics with different density.

    Science.gov (United States)

    Yuan, H; Fu, S; Tan, W; He, J; Wu, K

    2015-11-01

    The recycling of waste plastics is an important aspect in the recycling of solid waste. Based on the difference in density, PET and PVC particles was separated with help of the centrifugal sedimentation and shearing dispersion in a hydrocyclone. Through tests and CFD simulation, the relationship between the separating efficiency and pressure drop and split ratio has been investigated. Test results show that the Newton efficiency can reach above 80%, i.e. the purity of PVC could reach 93.2% while the purity of PET could reach 94.5%. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Theoretical study of the 2A 2 2B 2 separation of the alkali superoxides

    Science.gov (United States)

    Bauschlicher, Charles W., Jr.; Sodupe, Mariona; Partridge, Harry; Langhoff, Stephen R.

    1992-09-01

    The computed 2A 2 2B 2 separations of the alkali superoxides are in good agreement with those deduced from electron-spin resonance spectra. The calculations definitively show that the ground state of CsO 2 is 2A 2. The larger than expected separation for CsO 2, based on the trend from LiO 2 to RbO 2, is attributed primarily to the differential effects of core relaxation. The CsO 2 dissociation energy is computed to be 42.7 kcal/mol, with an uncertainty conservatively estimated as ±4 kcal/mol.

  15. Probing the selective separation of potassium ion from sodium ion with cyclopentadienyl anion as receptor: a computational study.

    Science.gov (United States)

    Desai, Mittal L; Si, Mrinal Kanti; Lo, Rabindranath; Ganguly, Bishwajit

    2015-08-01

    A systematic computational study has been carried out using post-Hartree-Fock and density functional theory methods on half sandwich (M-Cp), sandwich (Cp-M-Cp), inversed sandwich (M-Cp-M), and multi-decker chain complexes of alkali metal ions (Na(+), and K(+)). The binding affinity of cyclopentadienyl anion (Cp) with K(+) and Na(+) ions has been studied in half sandwich, sandwich, inversed sandwich, and multi-decker chain complexes. These complexes have been examined in the aqueous phase. The calculated results show that Cp anion can preferentially bind with Na(+) ion over K(+) ion in aqueous phase. The results obtained from DFT calculations have been compared with the crystal structures of Cp-Na and Cp-K complexes. The Bader's atoms in molecule (AIM) analysis were performed to characterize the non-covalent cation-π interactions in the Cp-M complexes. The calculated electron density at cage critical point indicates the strength of the Cp-M complexes. Energy decomposition analysis (EDA) has also been performed to investigate the origins of these interactions. The electrostatic interaction contributes significantly to the total interaction energy in Cp-M complexes. The relative stability difference of cyclopentadienyl anion (Cp) with K(+) and Na(+) ions in aqueous phase can be exploited for the separations from mixture such as sea bittern. The lower stability of K-Cp complex can induce to precipitate the K(+) ions more easily than the corresponding Na(+) ions. Graphical Abstract Potassium ion from sodium ion with cyclopentadienyl anion as receptor.

  16. Separating the Idea from the Action: A sLORETA Study.

    Science.gov (United States)

    Rakusa, Martin; Busan, Pierpaolo; Battaglini, Piero Paolo; Zidar, Janez

    2018-03-01

    Simple imaginary movements activate similar cortical and subcortical areas to actual movements, chiefly in the sensory-motor network. However, only a few studies also examined the imagery of more skilful movements such as reaching. Ten volunteers performed reaching movements or imagined the same movements. EEG was simultaneously recorded and analysed with sLORETA, which compared the preparation for actual and imagined reaching with respect to their baseline and between tasks. Major differences between them were found at three time intervals after target presentation, always in favour of the actual reaching condition. The first one was from 160 to 220 msec in the frontal and parietal regions. The second difference was evident from 220 to 320 msec in the premotor cortex. The third difference was evident from 320 msec, mainly in the perirolandic region. Also, the anterior and posterior cingulate cortices were widely involved, in both tasks. We suggest the existence of two separate systems which may work together during actual reaching programming. The first one involves structures such as the premotor cortex, supplementary motor area and primary motor cortex, together with the parietal and occipital cortex. This system may integrate extrinsic target coordinates with proprioceptive information from the reaching arm and pre-stored programs in the associative motor cortex. It is activated strongly and involves more cortical areas in actual than imagined reaching. The second system, common to both tasks, involves anterior and posterior cingulate cortices, with the possible role of contributing awareness and focusing the various components of the process.

  17. A laboratory-scale study of applied voltage on the electrokinetic separation of lead from soils

    Energy Technology Data Exchange (ETDEWEB)

    Viadero, R.C. Jr.; Reed, B.E.; Berg, M.; Ramsey, J. [West Virginia Univ., Morgantown, WV (United States). Dept. of Civil and Environmental Engineering

    1998-09-01

    The application of electrokinetic (EK) soil-flushing technology to the separation of lead from a nonsynthetic, fine-grained, low permeability soil was examined. In these laboratory-scale experiments the effects of applied voltage (30 and 60 V DC) on cumulative electroosmotic (EO) flow, charge-input, and lead removal were investigated. To develop a more generalized cause-effect relationship, these parameters were studied using three anode/cathode reservoir conditioning schemes: NaNO{sub 3}/NaNO{sub 3}, NaNO{sub 3}/HAc (acetic acid), and HCl/HAc. Charge-input and cumulative EO flow generally increased when the applied voltage was raised. When reservoir pH controls were used, results were more consistent with theoretically predicted outcomes. Increasing the applied voltage increased the electrolysis of water, which increased the fluid conductivity and charge-input. Although cumulative EO flow increased in proportion to the voltage, the advantage of operating at a higher applied voltage diminished as the amount of lead remaining in the soil decreased. The highest lead removal rates for both the 30 and 60 V tests were achieved using the 0.1 M HCl/1.0 M HAc reservoir conditioning scheme. The addition of HCl t the anode reservoir solution enhanced the impact of the acid front, especially during the initial pore volumes of flow which occurred before the oxidation of water could produce significant amounts of H{sup +} at the anode. Additionally, HAc in the cathode reservoir prevented the formation of a base front and the subsequent Pb readsorption/precipitation onto soil. The greater cumulative EO flow and charge-input in the experiments conducted with the HCl/HAc reservoir conditioning scheme resulted in faster Pb removal via advection and electrolytic migration.

  18. Separation from family and its impact on the mental health of Sudanese refugees in Australia: a qualitative study.

    Science.gov (United States)

    Savic, Michael; Chur-Hansen, Anna; Mahmood, Mohammad Afzal; Moore, Vivienne

    2013-08-01

    This study explored the impact of separation from family members on the mental health and wellbeing of Sudanese refugees in Australia, and the coping strategies used. In-depth interviews were conducted with Sudanese community representatives and health workers, primary and mental health care practitioners, health service managers and policy makers. Interviews were analysed using thematic analysis. Separation was perceived as having a negative impact on the mental health of Sudanese refugees in Australia, and manifested in concern about the safety of relatives abroad and in changing roles. The pressure to send money home emerged as a high priority for Sudanese refugees, often superseding local concerns. Several strategies were used to bridge the separation gap, including maintaining contact through the use of information communication technologies, and family-reunification. Separation from family can be an ongoing source of stress and sadness among refugees in countries such as Australia. While resettling refugees are actively taking steps to cope with the impact of separation, awareness of the issue in mainstream services appears to be low. Separation from family continues to affect refugees' lives in countries of resettlement. While it may be difficult to alter the course of the monumental circumstances that cause forced migration, service providers can support refugees' coping abilities by understanding these global-local intersections. © 2013 The Authors. ANZJPH © 2013 Public Health Association of Australia.

  19. Social interactions of dairy cows introduced postpartally to a separated barn section - pilot study

    DEFF Research Database (Denmark)

    Burow, Elke; Nielsen, Tine Rousing; Halekoh, Ulrich

    2009-01-01

    The hypothesis of reduced social activity of early lactating dairy cows when transferred postpartally to a separated barn section (S, group size 9.3 SD 2.1) vs. to a barn section of the main lactating herd (H, group size 130.1 SD 57.9) was tested. Social interactions of 12 cows in S and 14 cows...

  20. Atomic level characterization in corrosion studies

    Science.gov (United States)

    Marcus, Philippe; Maurice, Vincent

    2017-06-01

    Atomic level characterization brings fundamental insight into the mechanisms of self-protection against corrosion of metals and alloys by oxide passive films and into how localized corrosion is initiated on passivated metal surfaces. This is illustrated in this overview with selected data obtained at the subnanometre, i.e. atomic or molecular, scale and also at the nanometre scale on single-crystal copper, nickel, chromium and stainless steel surfaces passivated in well-controlled conditions and analysed in situ and/or ex situ by scanning tunnelling microscopy/spectroscopy and atomic force microscopy. A selected example of corrosion modelling by ab initio density functional theory is also presented. The discussed aspects include the surface reconstruction induced by hydroxide adsorption and formation of two-dimensional (hydr)oxide precursors, the atomic structure, orientation and surface hydroxylation of three-dimensional ultrathin oxide passive films, the effect of grain boundaries in polycrystalline passive films acting as preferential sites of passivity breakdown, the differences in local electronic properties measured at grain boundaries of passive films and the role of step edges at the exposed surface of oxide grains on the dissolution of the passive film. This article is part of the themed issue 'The challenges of hydrogen and metals'.

  1. Exposure to parental separation in childhood and later parenting quality as an adult: evidence from a 30-year longitudinal study.

    Science.gov (United States)

    Friesen, Myron D; John Horwood, L; Fergusson, David M; Woodward, Lianne J

    2017-01-01

    Previous research has documented that exposure to parental separation/divorce during childhood can be associated with long-term consequences into adulthood. This study sought to extend this literature by examining associations between childhood exposure to parental separation/divorce and later parenting behavior as an adult in a New Zealand birth cohort. Data were drawn from the Christchurch Health and Development Study (CHDS), a longitudinal study of a birth cohort of 1,265 children born in 1977 in Christchurch, New Zealand. Information about exposure to parental separation and divorce was gathered annually from birth to 15 years. At the 30-year follow-up, all cohort members who had become parents (biological or nonbiological) were assessed on several parenting dimensions (sensitivity, warmth, overreactivity, inconsistency, quality of child management, and physical punishment). The analyses showed that exposure to more frequent parental separation in childhood and adolescence was associated with lower levels of parental sensitivity and warmth, greater overreactivity, and an increased use of physical punishment as a parent, after controlling for a wide range of family socioeconomic and psychosocial factors, and individual child characteristics. The findings suggest that as exposure to parental separation increases, so does the likelihood of experiencing multiple developmental challenges in childhood and adolescence. As an adult, these life-course experiences can have small but significant associations with the quality of parenting behavior. © 2016 Association for Child and Adolescent Mental Health.

  2. Cognitive-Behavioral Therapy with a Six-Year-Old Boy with Separation Anxiety Disorder: A Case Study.

    Science.gov (United States)

    Dia, David A.

    2001-01-01

    This study examines the use of cognitive-behavioral therapy (CBT) for the treatment of separation anxiety disorder (SAD) in a six-year-old boy who was having at least one panic attack a day. It uses a four-phased program that includes a psychoeducational approach. The outcome studies demonstrated how CBT shows promise as a treatment modality with…

  3. Computational Studies of CO 2 Sorption and Separation in an Ultramicroporous Metal–Organic Material

    KAUST Repository

    Forrest, Katherine A.

    2013-08-29

    Grand canonical Monte Carlo (GCMC) simulations of CO2 sorption and separation were performed in [Zn(pyz)2SiF6], a metal-organic material (MOM) consisting of a square grid of Zn2+ ions coordinated to pyrazine (pyz) linkers and pillars of SiF6 2- ions. This MOM was recently shown to have an unprecedented selectivity for CO2 over N2, CH4, and H 2 under industrially relevant conditions. The simulated CO 2 sorption isotherms and calculated isosteric heat of adsorption, Qst, values were in excellent agreement with the experimental data for all the state points considered. CO2 saturation in [Zn(pyz) 2SiF6] was achieved at near-ambient temperatures and pressures lower than 1.0 atm. Moreover, the sorbed CO2 molecules were representative of a liquid/fluid under such conditions as confirmed through calculating the isothermal compressibility, βT, values. The simulated CO2 uptakes within CO2/N2 (10:90), CO2/CH4 (50:50), and CO2/H2 (30:70) mixture compositions, characteristic of flue gas, biogas, and syngas, respectively, were comparable to those that were produced in the single-component CO2 sorption simulations. The modeled structure at saturation revealed a loading of 1 CO2 molecule per unit cell. The favored CO2 sorption site was identified as the attraction of the carbon atoms of CO2 molecules to four equatorial fluorine atoms of SiF6 2- anions simultaneously, resulting in CO2 molecules localized at the center of the channel. Furthermore, experimental studies have shown that [Zn(pyz)2SiF6] sorbed minimal amounts of CO2 and N2 at their respective liquid temperatures. Analysis of the crystal structure at 100 K revealed that the unit cell undergoes a slight contraction in all dimensions and contains pyrazine rings that are mildly slanted with an angle of 13.9. Additionally, molecular dynamics (MD) simulations revealed that the sorbate molecules are anchored to the framework at low temperatures, which inhibits diffusion. Thus, it is hypothesized that the sorbed molecules

  4. Synthesis, characterization, photocatalytic and reusability studies of ...

    Indian Academy of Sciences (India)

    This paper presents results of a study on the structural and morphological properties of 2-mercaptoethanol (2-ME) capped ZnS nanoparticles (NPs). The photocatalytic and reusability study of the synthesized NPs to degrade dyes was also done. ZnS semiconductor NPs were synthesized via chemical precipitation route ...

  5. Characterization study of industrial waste glass as starting material ...

    African Journals Online (AJOL)

    In present study, an industrial waste glass was characterized and the potential to assess as starting material in development of bioactive materials was investigated. A waste glass collected from the two different glass industry was grounded to fine powder. The samples were characterized using X-ray fluorescence (XRF), ...

  6. Studies on separation and purification of fission (99)Mo from neutron activated uranium aluminum alloy.

    Science.gov (United States)

    Rao, Ankita; Kumar Sharma, Abhishek; Kumar, Pradeep; Charyulu, M M; Tomar, B S; Ramakumar, K L

    2014-07-01

    A new method has been developed for separation and purification of fission (99)Mo from neutron activated uranium-aluminum alloy. Alkali dissolution of the irradiated target (100mg) results in aluminum along with (99)Mo and a few fission products passing into solution, while most of the fission products, activation products and uranium remain undissolved. Subsequent purification steps involve precipitation of aluminum as Al(OH)3, iodine as AgI/AgIO3 and molybdenum as Mo-α-benzoin oxime. Ruthenium is separated by volatilization as RuO4 and final purification of (99)Mo was carried out using anion exchange method. The radiochemical yield of fission (99)Mo was found to be >80% and the purity of the product was in conformity with the international pharmacopoeia standards. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Blind source separation methods applied to synthesized polysomnographic recordings: a comparative study.

    Science.gov (United States)

    Kachenoura, Amar; Albera, Laurent; Senhadji, Lotfi

    2007-01-01

    Blind Source Separation (BSS) problems, under the assumption of static mixture, were extensively explored from the theoretical point of view. Powerful algorithms are now at hand to deal with many concrete BSS applications. Nevertheless, the performances of BSS methods, for a given biomedical application, are rarely investigated. The aim of this paper is to perform quantitative comparisons between various well-known BSS techniques. To do so, synthetic data, reproducing real polysomnographic recordings, are considered.

  8. Basic study on isotope separation using light induced drift effects (Progress report)

    Energy Technology Data Exchange (ETDEWEB)

    Suto, Osamu; Yamaguchi, Hiromi; Suzuki, M. [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan). Tokai Works; Ishii, K.

    1999-03-01

    As a preliminary research on {sup 15}N-isotope separation on the basis of light induced drift (LID) effects in NH{sub 3}, the authors have confirmed the feasibility on {sup 13}C-isotope separation using LID effects in CH{sub 3}F for which all the necessary spectroscopic data are available and found that: (1) Concentration difference at the entrance and at the exit end of the drift tube {delta}n{sub a} (number/cm{sup 3}) was proportional to the energy density absorbed ({delta}W/cm{sup 2}), indicating the validity of theoretical LID equation. (2) Pressure dependence of {delta}n{sub a}/{delta}S was maximum at ca. 0.5 Torr. Lower {delta}n{sub a}/{delta}S values are due to power saturation effects at low pressures and due to absorption line broadening at high pressures. (3) Maximum isotopic selectivity was obtained at 0.5 Torr and to be 1.18. (4) Time needed for {delta}n{sub a} to attain the equilibrium increased with increasing pressure. They concluded that the possibility of {sup 15}N isotope separation using NH{sub 3}-LID effect was in principle confirmed. (S. Ohno)

  9. Droplet activation, separation, and compositional analysis: laboratory studies and atmospheric measurements

    Directory of Open Access Journals (Sweden)

    N. Hiranuma

    2011-10-01

    Full Text Available Droplets produced in a cloud condensation nuclei chamber (CCNC as a function of supersaturation have been separated from unactivated aerosol particles using counterflow virtual impaction. Residual material after droplets were evaporated was chemically analyzed with an Aerodyne Aerosol Mass Spectrometer (AMS and the Particle Analysis by Laser Mass Spectrometry (PALMS instrument. Experiments were initially conducted to verify activation conditions for monodisperse ammonium sulfate particles and to determine the resulting droplet size distribution as a function of supersaturation. Based on the observed droplet size, the counterflow virtual impactor cut-size was set to differentiate droplets from unactivated interstitial particles. Validation experiments were then performed to verify that only droplets with sufficient size passed through the counterflow virtual impactor for subsequent analysis. A two-component external mixture of monodisperse particles was also exposed to a supersaturation which would activate one of the types (hygroscopic salts but not the other (polystyrene latex spheres or adipic acid. The mass spectrum observed after separation indicated only the former, validating separation of droplets from unactivated particles. Results from ambient measurements using this technique and AMS analysis were inconclusive, showing little chemical differentiation between ambient aerosol and activated droplet residuals, largely due to low signal levels. When employing as single particle mass spectrometer for compositional analysis, however, we observed enhancement of sulfate in droplet residuals.

  10. Synthesis, characterization, photocatalytic and reusability studies of ...

    Indian Academy of Sciences (India)

    Administrator

    2.2 Apparatus for photocatalytic study. Photocatalytic degradation experiment was conducted in dark using self-designed photochemical reactor at room temperature. The apparatus consisted of a cylindrical glass cell of 1 L capacity. A mercury lamp (λ = 300–400 nm) was placed in a glass tube. The lamp and tube were then.

  11. Growth, characterization and dielectric studies of gadolinium ...

    Indian Academy of Sciences (India)

    Abstract. Gadolinium fumarate heptahydrate single crystals were grown by the single gel diffusion technique using silica gel as a medium of growth. Nucleation rate of these crystals was studied corresponding to the effect of various growth parameters. An attempt was made to relate the experimental results with the classical ...

  12. synthesis, characterization and antibacterial studies of metal

    African Journals Online (AJOL)

    Preferred Customer

    topical burn [10, 11]. At present, the possibility of using metal complexes of sulfadiazine as antimicrobial agents has received some attention [12-14]. Metal complexes of dithiocarbamates are widely studied due to their biological, chemical, agricultural and industrial applications [15-. 17]. The presence of the dithiocarbamate ...

  13. Synthesis, characterization, antibacterial and antifungal studies of ...

    African Journals Online (AJOL)

    The physico-chemical study supports the presence of square planar geometry around Cu(II) and octahedral geometry around Mn(II), Co(II), La(III) and Ce(III) ions. The IR spectral data reveal that the ligand behaves as bidentate with ON donor atom sequence towards central metal ion. The molar conductance values of metal ...

  14. Preparation and characterization of poly(triallyl isocyanurate-co-trimethylolpropane triacrylate) monolith and its applications in the separation of small molecules by liquid chromatography.

    Science.gov (United States)

    Zhong, Jing; Hao, Mengbei; Li, Ruo; Bai, Ligai; Yang, Gengliang

    2014-03-14

    A new polymeric monolith was prepared in stainless-steel column and fused-silica capillary, respectively, by atom transfer radical polymerization technique. In the polymerization, triallyl isocyanurate (TAIC) was used as the functional monomer; trimethylolpropane triacrylate (TMPTA) as the crosslinking agent; polyethylene glycol 200 and 1,2-propanediol as the co-porogens; carbon tetrachloride as the initiator and ferrous chloride as the catalyst. The conditions of polymerization were optimized. Morphology of the prepared poly(TAIC-co-TMPTA) monolith was investigated by scanning electron microscopy; pore properties were assayed by mercury porosimetry and nitrogen adsorption. The characterization indicated that the prepared reversed-phase monolith possessed uniform structure, good permeability and mechanical stability. The column was used as the stationary phase of reversed phase high performance liquid chromatography (RP-HPLC) and capillary liquid chromatography (CLC) to separate the mixture of aromatic compounds. The new column performed around 125,000 theoretical plates per meter. The column showed good reproducibility: the relative standard deviation values of the retention factor values for aromatic compounds were less than 1.52% (n=7, column-to-column). Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Magnetically separable CuFe{sub 2}O{sub 4}/AgBr composite photocatalysts: Preparation, characterization, photocatalytic activity and photocatalytic mechanism under visible light

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yalei; Lin, Cuiping; Bi, Huijie; Liu, Yonggang; Yan, Qishe, E-mail: Qisheyanzzu@163.com

    2017-01-15

    Highlights: • CuFe{sub 2}O{sub 4}/AgBr composites were prepared by a facile sol-gel and hydrothermal method. • Visible-light response and high photocatalytic performance. • Excellent magnetic properties. • Different reactive species had different effects on degradation different pollutants. - Abstract: The CuFe{sub 2}O{sub 4} and CuFe{sub 2}O{sub 4}/AgBr composites with different CuFe{sub 2}O{sub 4} contents were prepared by a facile sol-gel and hydrothermal method, respectively. The as-synthesized photocatalysts were characterized by means of powder X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and UV–vis diffuse reflectance spectrum (UV–vis DRS). Their magnetic properties, photocatalytic degradation activities on methyl orange (MO) and tetracycline hydrochloride (TC) solution and photocatalytic mechanism were investigated in detail. The results revealed that the CuFe{sub 2}O{sub 4}/AgBr composites exhibited significantly higher photocatalytic activities than the pure CuFe{sub 2}O{sub 4}. The enhanced photocatalytic activity could be attributed to the matched band structure of two components and more effective charge transportation and separations. In addition, the quenching investigation of different scavengers demonstrated that h{sup +}, ·OH, ·O{sub 2}{sup −} reactive species played different roles in the decolorization of MO and degradation of TC.

  16. A population-based study of the risk of schizophrenia and bipolar disorder associated with parent-child separation during development.

    Science.gov (United States)

    Paksarian, D; Eaton, W W; Mortensen, P B; Merikangas, K R; Pedersen, C B

    2015-10-01

    There is growing interest in the role of childhood adversities, including parental death and separation, in the etiology of psychotic disorders. However, few studies have used prospectively collected data to specifically investigate parental separation across development, or assessed the importance of duration of separation, and family characteristics. We measured three types of separation not due to death: maternal, paternal, and from both parents, across the ages of 1-15 years among a cohort of 985 058 individuals born in Denmark 1971-1991 and followed to 2011. Associations with narrowly and broadly defined schizophrenia and bipolar disorder in the psychiatric register were assessed in terms of separation occurrence, age of separation, and number of years separated. Interactions with parental history of mental disorder were assessed. Each type of separation was associated with all three outcomes, adjusting for age, sex, birth period, calendar year, family history of mental disorder, urbanicity at birth and parental age. Number of years of paternal separation was positively associated with both schizophrenia and bipolar disorder. Associations between separation from both parents and schizophrenia were stronger when separation occurred at later ages, while those with bipolar disorder remained stable across development. The first occurrence of paternal separation appeared to increase risk more when it occurred earlier in childhood. Associations differed according to parental history of mental disorder, although in no situation was separation protective. Effects of parental separation may differ by type, developmental timing and family characteristics. These findings highlight the importance of considering such factors in studies of childhood adversity.

  17. CENTRIFUGAL SEPARATORS

    Science.gov (United States)

    Skarstrom, C.

    1959-03-10

    A centrifugal separator is described for separating gaseous mixtures where the temperature gradients both longitudinally and radially of the centrifuge may be controlled effectively to produce a maximum separation of the process gases flowing through. Tbe invention provides for the balancing of increases and decreases in temperature in various zones of the centrifuge chamber as the result of compression and expansions respectively, of process gases and may be employed effectively both to neutralize harmful temperature gradients and to utilize beneficial temperaturc gradients within the centrifuge.

  18. Synthesis of Actinide Materials for the Study of Basic Actinide Science and Rapid Separation of Fission Products

    Energy Technology Data Exchange (ETDEWEB)

    Dorhout, Jacquelyn Marie [Univ. of Nevada, Las Vegas, NV (United States)

    2017-11-28

    This dissertation covers several distinct projects relating to the fields of nuclear forensics and basic actinide science. Post-detonation nuclear forensics, in particular, the study of fission products resulting from a nuclear device to determine device attributes and information, often depends on the comparison of fission products to a library of known ratios. The expansion of this library is imperative as technology advances. Rapid separation of fission products from a target material, without the need to dissolve the target, is an important technique to develop to improve the library and provide a means to develop samples and standards for testing separations. Several materials were studied as a proof-of-concept that fission products can be extracted from a solid target, including microparticulate (< 10 μm diameter) dUO2, porous metal organic frameworks (MOFs) synthesized from depleted uranium (dU), and other organicbased frameworks containing dU. The targets were irradiated with fast neutrons from one of two different neutron sources, contacted with dilute acids to facilitate the separation of fission products, and analyzed via gamma spectroscopy for separation yields. The results indicate that smaller particle sizes of dUO2 in contact with the secondary matrix KBr yield higher separation yields than particles without a secondary matrix. It was also discovered that using 0.1 M HNO3 as a contact acid leads to the dissolution of the target material. Lower concentrations of acid were used for future experiments. In the case of the MOFs, a larger pore size in the framework leads to higher separation yields when contacted with 0.01 M HNO3. Different types of frameworks also yield different results.

  19. A fine coal circuitry study using column flotation and gravity separation. Quarterly report, 1 March 1995--31 May 1995

    Energy Technology Data Exchange (ETDEWEB)

    Honaker, R.Q. [Southern Illinois Univ., Carbondale, IL (United States); Reed, S. [Kerr-McGee Coal Corp., Oklahoma City, OK (United States)

    1995-12-31

    Column flotation provides excellent recovery of ultrafine coal while producing low ash content concentrates. However, column flotation is not efficient for treating fine coal containing significant amounts of mixed-phase particles. Fortunately, enhanced gravity separation has proved to have the ability to treat the mixed-phased particles more effectively. A disadvantage of gravity separation is that ultrafine clay particles are not easily rejected. Thus, a combination of these two technologies may provide a circuit that maximizes both the ash and sulfur rejection that can be achieved by physical coal cleaning while maintaining a high energy recovery. This project is studying the potential of using different combinations of gravity separators, i.e., a Floatex hydrosizer and a Falcon Concentrator, and a proven flotation column, which will be selected based on previous studies by the principle investigator. During this reporting period, an extensive separation performance comparison between a pilot-scale Floatex Density Separator (18{times}18-inch) and an existing spiral circuit has been conducted at Kerf-McGee Coal Preparation plan for the treatment of nominally {minus}16 mesh coal. The results indicate that the Floatex is a more efficient separation device (E{sub p}=0.12) than a conventional coal spiral (E{sub p}=0.18) for Illinois seam coals. In addition, the treatment of {minus}100 mesh Illinois No. 5 fine coal from the same plant using Falcon concentrator, column flotation (Packed-Column) and their different combinations was also evaluated. For a single operation, both Falcon concentrator and column flotation can produce a clean coal product with 90% combustible recovery and 5% ash content. In the case of the combined circuit, column flotation followed by the Falcon achieved a higher combustible recovery value (about 75%) than that obtained by the individual units while maintaining an ash content less than 3%.

  20. synthesis, characterization, electrical and catalytic studies of some

    African Journals Online (AJOL)

    B. S. Chandravanshi

    SYNTHESIS, CHARACTERIZATION, ELECTRICAL AND CATALYTIC STUDIES. OF SOME COORDINATION COMPOUNDS DERIVED FROM UNSYMMETRICAL. SCHIFF BASE LIGAND. Gaurav B. Pethe, Amit R. Yaul and Anand S. Aswar*. Department of Chemistry, Sant Gadge Baba Amravati University, Amravati-444 602 ...

  1. Fatigue study of ultra-runners: Presentation of a new approach for the separation of GRF signals components

    Science.gov (United States)

    Zakaria, F. A.; El Badaoui, M.; Lamraoui, M.; Khalil, M.

    2016-06-01

    In recent years, ultra-marathon running has become increasingly popular in many countries around the world. The ability to run for long hours has played a role in human evolution. It is known that the etiology of fatigue depends upon the exercise under consideration. In order to characterize and find a full description of the fatigue and its effects on the human locomotion mechanics, and to extract the relevant parameters and information for diagnosis, we have investigated the changes in running mechanics. More specifically, the ground reaction force (GRF) manifestations of fatigue, have been investigated by using advanced signal processing tools. GRF signals are composed of two parts: an active peak representing the propulsive force and a passive peak that represents the impact force. The impact force is the major factor indicating the reaction of muscle, that may reflects the fatigue state and performance of the muscle. In this article, we focused on the treatment of biomechanical signals for the purpose of GRF components separation where the aim is to separate the contribution of the active components and the passive components. For this reason, we proposed a new algorithm, based on the Gaussian decomposition and non-linear least squares method that will achieve the desired goal. We then compare the results of separation with a proposed BSS based method i.e. ;FastICA algorithm;. We also compare the results with that obtained by Sabri et al. [1-3] who used different BSS techniques which gave bad and fair results. The separated passive signal is then proved to contain a mixture of a deterministic phenomenon and a stationary random phenomenon, where both phenomena are separated using the cepstral editing procedure (CEP) method. CEP is applied after signal synchronization using method with maximization of the inter-correlation function. The random part is then proved to be cyclostationary of order 2. A real application examined the biomechanical changes occurring in

  2. Studies into new solvent extraction reagents for the separation of trivalent minor actinides from trivalent lanthanides

    CERN Document Server

    Russell, M L

    2000-01-01

    Ligands, suitable for the separation of minor actinide(lll) cations from lanthanide(lll) cations from acidic aqueous media, have been synthesised. Two oligopyridine ligands, 4', 4''-(bis (4-tolyl))-2, 2': 6', 2'': 6'', 2'''-quaterpyridine and 4',4'''-(bis(4-heptyloxyphenyl))-2,2':6',2'':6'',2''':6''',2'''' -quinquepyridi= ne, have been synthesised and tested by solvent extraction experiments. The ability of the ligands to separate minor actinide from lanthanide has been attributed to the number of pyridyl rings present. A series of terpyridine analogues based on sym-triazine have been prepared, via the cyclisation of aromatic carbonitriles with guanidine. New lipophilic derivatives of 2-amino-bis(4,6(2-pyridyl))-1,3,5-triazine, 2-amino-bis(4,6(2-pyrazinyl)-1,3,5-triazine, 2-amino-bis(4,6(2-isoquinolinyl)-1,3,5-triazine, 2-amino-bis(4,6(2-(4-methyl)pyridyl)-1,3,5-triazine, 2-amino-bis(4,6(4-pyridyl)-1,3,5-triazine, 2-amino-bis(4,6(2-thiophenyl)-1,3,5-triazine and 2-amino-bis(4,6(2-quinolinyl)-1,3,5-triazine ha...

  3. [Study on extracting and separating curcuminoids from Curcuma longa rhizome using ultrasound strengthen by microemulsion].

    Science.gov (United States)

    Yue, Chun-Hua; Zheng, Li-Tao; Guo, Qi-Ming; Li, Kun-Ping

    2014-05-01

    To establish a new method for the extraction and separation of curcuminoids from Curcuma longa rhizome by cloud-point preconcentration using microemulsions as solvent. The spectrophotometry was used to detect the solubility of curcumin in different oil phase, emulsifier and auxiliary emulsifier, and the microemulsion prescription was used for false three-phase figure optimization. The extraction process was optimized by uniform experiment design. The curcuminoids were separated from microemulsion extract by cloud-point preconcentration. Oil phase was oleic acid ethyl ester; Emulsifier was OP emulsifier; Auxiliary emulsifier was polyethylene glycol(peg) 400; The quantity of emulsifier to auxiliary emulsifier was the ratio of 5: 1; Microemulsion prescription was water-oleic acid ethyl ester-mixed emulsifier (0.45:0.1:0.45). The optimum extraction process was: time for 12.5 min, temperature of 52 degrees C, power of 360 W, frequency of 400 kHz, and the liquid-solid ratio of 40:1. The extraction rate of curcuminoids was 92.17% and 86.85% in microemulsion and oil phase, respectively. Curcuminoids is soluble in this microemulsion prescription with good extraction rate. This method is simple and suitable for curcuminoids extraction from Curcuma longa rhizome.

  4. Epidemiological characterization of oral cancer. Study Protocol.

    Directory of Open Access Journals (Sweden)

    Alejandra Fernández

    2015-04-01

    Full Text Available Oral cancer is a disease of high impact globally. It ranks as the sixth more frequent one among all types of cancer. In spite of being a widely known pathology and easy access to the diagnosis, the lack of epidemiological data reported in the last 10 years in Chile called attention to. At the global level, the World Health Organization (WHO has developed a project called “GLOBOCAN” in order to collect epidemiological data of the global cancer, between its data, highlights the high incidence and high rate of mortality in the male sex, parameter that shows tendency to replicate in both America and Chile. In consequence to these data, a narrative review of the literature concerning the epidemiological profile of the different forms of oral cancer in the past 15 years was done. The diagnosis of oral cancer crosses transversely the Dental Science, forcing us to establish triads of work between oral and maxillofacial surgeons, pathologists and dentists of the various specialties, so as to allow a timely research, appropriate biopsies and histopathological studies finishes with the purpose of, on the one hand, obtain timely and accurate diagnostics, in addition, maintaining the epidemiological indicators.

  5. Coal liquefaction process streams characterization and evaluation: Application of liquid chromatographic separation methods to THF-soluble portions of integrated two-stage coal liquefaction resids

    Energy Technology Data Exchange (ETDEWEB)

    Green, J.B.; Pearson, C.D.; Young, L.L.; Green, J.A. (National Inst. for Petroleum and Energy Research, Bartlesville, OK (United States))

    1992-05-01

    This study demonstrated the feasibility of using non-aqueous ion exchange liquid chromatography (NIELC) for the examination of the tetrahydrofuran (THF)-soluble distillation resids and THF-soluble whole oils derived from direct coal liquefaction. The technique can be used to separate the material into a number of acid, base, and neutral fractions. Each of the fractions obtained by NIELC was analyzed and then further fractionated by high-performance liquid chromatography (HPLC). The separation and analysis schemes are given in the accompanying report. With this approach, differences can be distinguished among samples obtained from different process streams in the liquefaction plant and among samples obtained at the same sampling location, but produced from different feed coals. HPLC was directly applied to one THF-soluble whole process oil without the NIELC preparation, with limited success. The direct HPLC technique used was directed toward the elution of the acid species into defined classes. The non-retained neutral and basic components of the oil were not analyzable by the direct HPLC method because of solubility limitations. Sample solubility is a major concern in the application of these techniques.

  6. Separation and Characterization of Angiotensin I Converting Enzyme (ACE) Inhibitory Peptides from Saurida elongata Proteins Hydrolysate by IMAC-Ni2.

    Science.gov (United States)

    Sun, Lixia; Wu, Shanguang; Zhou, Liqin; Wang, Feng; Lan, Xiongdiao; Sun, Jianhua; Tong, Zhangfa; Liao, Dankui

    2017-02-15

    Lizard fish protein hydrolysates (LFPH) were prepared from Lizard fish (Saurida elongata) proteins possessing powerful angiotensin I converting enzyme (ACE) inhibitory activity and the fraction (LFPH-I) with high ACE inhibitory activity was obtained through ultrafiltration. The active Fraction (F2) was isolated from LFPH-I using immobilized metal affinity chromatography (IMAC-Ni2+). Analysis of amino acid levels revealed that F2 eluted from IMAC was enriched in Met, His, Tyr, Pro, Ile, and Leu compared to the crude peptide LFPH-I. F2 with the high ACE inhibitory activity (IC50 of 0.116 mg·mL-1) was further separated by a reverse-phase column to yield a novel ACE inhibitory peptide with IC50 value of 52 μM. The ACE inhibitory peptide was identified as Arg-Tyr-Arg-Pro, RYRP. The present study demonstrated that IMAC may be a useful tool for the separation of ACE inhibitory peptides from protein hydrolysate.

  7. A Mechanistic Study of Chemically Modified Inorganic Membranes for Gas and Liquid Separations

    Energy Technology Data Exchange (ETDEWEB)

    Way, J. Douglas [Colorado School of Mines, Golden, CO (United States). Dept. of Chemical Engineering

    2011-01-21

    This final report will summarize the progress made during the period August 1, 1993 - October 31, 2010 with support from DOE grant number DE-FG03-93ER14363. The objectives of the research have been to investigate the transport mechanisms in micro- and mesoporous, metal oxide membranes and to examine the relationship between the microstructure of the membrane, the membrane surface chemistry, and the separation performance of the membrane. Examples of the membrane materials under investigation are the microporous silica hollow fiber membrane manufactured by PPG Industries, chemically modified mesoporous oxide membranes, and polymer membranes containing microporous oxides (mixed matrix membranes). Analytical techniques such as NMR, FTIR and Raman spectroscopy, thermal analysis, and gas adsorption were used to investigate membrane microstructure and to probe the chemical interactions occurring at the gas-membrane interface.

  8. Study on preparation of a vovel silica adsorbent and its selective separation applied to genistein

    Directory of Open Access Journals (Sweden)

    Yuqing Zhang

    2008-03-01

    Full Text Available In order to selectively separate genistein from its crude solution, a novel silica adsorbent was prepared using genistein as the template molecule, gamma-aminopropylthriethoxysilane as the functional monomer and tetraethyl orthosilicate as the cross-linker. It was analyzed by the BET, FTIR, TEM characteristics, the static adsorption experiment, and selective adsorption experiment. The results show that the silica adsorbent has high specific area, special selectivity and high adsorption capacity for genistein. It can recognize and bind genistein in aqueous solution, and lots of nanopores distribute on its surface uniformly. It is concluded that both the shape and size of the recognition sites matching the template molecule result in the performance of this adsorbent to bind genistein and that there are strong ionic and hydrogen bond attractions between the phenolic hydroxyl and the -NH2.

  9. The Impact of Marital Separation/Divorce on Children: III. Parent-Child Communication and Child Adjustment, and Regression Analysis of Findings from Overall Study.

    Science.gov (United States)

    Jacobson, Doris S.

    1978-01-01

    This is the third of a series of reports on the findings from a study directed at further understanding the impact of marital separation/divorce on children during the 12-month period following the parental separation. This paper reports on parent-child communication regarding cognitive preparation of children for the parental separation. (Author)

  10. Structural characterization of hydrogen separating membranes based on lanthanide-tungstates; Strukturelle Charakterisierung von Wasserstoff trennenden Gasseparationsmembranen auf Lanthanoid-Wolframat-Basis

    Energy Technology Data Exchange (ETDEWEB)

    Scherb, Tobias

    2011-08-26

    The global energy supply is currently the most controversial issue discussed in our society. Despite the increasing importance of renewable energies, the largest portion of electrical energy has its origin in fossil fuels. CO{sub 2}, emitted during combustion in power plants is known to be one of the greenhouse gases that contributes significantly to global climate change. The development of technologies for environmentally friendly power generation from coal and gas is an area of significant interest. One possibility is the capture and long-term storage of CO{sub 2} from the exhaust stream of fossil fuel power plants. In the pre-combustion process, CO{sub 2} and H{sub 2} can be separated after gasification of the fossil fuel. For this purpose gas-tight ceramic membranes with mixed electronic-protonic conductivity can be used. However, these materials have high requirements due to the extreme conditions in power plants. Mixed electronic-protonic conducting lanthanide tungstates (Ln{sub 6}WO{sub 12} Ln = lanthanide or yttrium) are promising materials, which are stable in CO{sub 2}-containing harsh environments. This work presents a study on structure-property relationships of Ln{sub 6}WO{sub 12}. The structural analysis was performed by the use of neutron and high-resolution X-ray diffraction methods for three exemplary systems (Ln = La, Nd, Y). Samples were prepared via solid state reaction (SSR), and also via a sol-gel approach (Pechini). For the systems LaWO and NdWO, new structural models were developed by combined Rietveld analysis and Fourier density maps. The latter was applied to determine the electron and nuclear density distribution. LaWO with a La/W ratio from 5.3 to 5.7 crystallizes with the space group F-43m and forms a superstructure due to a partially ordered arrangement of cations. On Wyckoff site 48h, up to 4.6 % W can be substituted by La. The oxygen atoms around tungsten are highly delocalized and 6 out of 24 possible split positions are occupied

  11. A fine coal circuitry study using column flotation and gravity separation. Technical report, September 1--November 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Honaker, R.Q. [Southern Illinois Univ., Carbondale, IL (United States). Dept. of Mining Engineering; Reed, S. [Kerr-McGee Coal Corp., Oklahoma City, OK (United States)

    1994-12-31

    Column flotation provides excellent recovery of ultrafine coal while producing low ash content concentrates. However, column flotation is not efficient for treating fine coal containing significant amounts of mixed-phase particles. Fortunately, enhanced gravity separation has proved to have the ability to treat the mixed-phased particles more effectively. A disadvantage of gravity separation is that ultrafine clay particles are not easily rejected. Thus, a combination of these two technologies may provide a circuit that maximizes both the ash and sulfur rejection that can be achieved by physical coal cleaning while maintaining a high energy recovery. This project is studying the potential of using different combinations of gravity separators, i.e., a Floatex hydrosizer and a Falcon Concentrator, and a proven flotation column, which will be selected based on previous studies by the principle investigator. The gravity/flotation circuits will be compared based on their optimum separation performance which will consider ash and total sulfur rejection and energy recovery as well as the probable error (E{sub p}) value obtained from washability analyses. During this reporting period, multi-stage treatment using the Falcon concentrator was conducted on a refuse pond ({minus}100 mesh) coal sample and a {minus}28 mesh run-of-mine coal sample. The results suggest that the Falcon concentrator can make an ideal separation for either sample in a single process. Recleaning was found to improve product grade, however, recovery was reduced sharply. In addition, the groups involved with the in-plant testing of the Floatex Hydrosizer met and organized the test plan which will be conducted at Kerr-McGee`s Galatia preparation plant during the next reporting period. Coal samples for the circuitry tests will be collected during, this time period.

  12. Study of the enantiomeric separation of oxfendazole and cetirizine using subcritical fluid chromatography on an amylose-based column.

    Science.gov (United States)

    Toribio, L; del Nozal, M J; Bernal, J L; Cristofol, C; Alonso, C

    2006-07-21

    The enantiomeric separation of cetirizine and oxfendazole on a Chiralpak AD column using subcritical fluid chromatography has been studied in this work. The enantioseparation of cetirizine was only possible when 2-propanol was used as a modifier, obtaining better results in presence of the additives triethylamine (TEA) and trifluoroacetic acid (TFAA). On the contrary, 2-propanol provided the lowest enantioresolutions for oxfendazole, in this case the best results in terms of high resolution and short analysis time were obtained with ethanol. The study of the temperature effect revealed that in the case of cetirizine using 2-propanol, and oxfendazole using methanol, the separation was enthalpy-driven and the isoelution temperature was above the working range. Using ethanol or 2-propanol, the results showed that the oxfendazole enantioseparation was entropically driven and the isoelution temperatures were below the range studied.

  13. Isotope separation

    Science.gov (United States)

    Bartlett, Rodney J.; Morrey, John R.

    1978-01-01

    A method and apparatus is described for separating gas molecules containing one isotope of an element from gas molecules containing other isotopes of the same element in which all of the molecules of the gas are at the same electronic state in their ground state. Gas molecules in a gas stream containing one of the isotopes are selectively excited to a different electronic state while leaving the other gas molecules in their original ground state. Gas molecules containing one of the isotopes are then deflected from the other gas molecules in the stream and thus physically separated.

  14. ISOTOPE SEPARATORS

    Science.gov (United States)

    Bacon, C.G.

    1958-08-26

    An improvement is presented in the structure of an isotope separation apparatus and, in particular, is concerned with a magnetically operated shutter associated with a window which is provided for the purpose of enabling the operator to view the processes going on within the interior of the apparatus. The shutier is mounted to close under the force of gravity in the absence of any other force. By closing an electrical circuit to a coil mouated on the shutter the magnetic field of the isotope separating apparatus coacts with the magnetic field of the coil to force the shutter to the open position.

  15. Effects of Family Structure and the Experience of Parental Separation: A Study on Adolescents’ Well-Being

    Directory of Open Access Journals (Sweden)

    Sabine Walper

    2015-10-01

    Full Text Available Large numbers of studies, mostly from the U.S., have addressed the effects of parental separation and divorce, pointing to disadvantages of children and adolescents growing up in separated families. However, evidence on this topic varies across countries and is limited for Germany. Using longitudinal data from waves 1 and 3 of the German Family Panel pairfam, we investigated differences in adolescents’ well-being by comparing stable nuclear families (n = 1968, single mother families (n = 360, and stepfather families (n = 214, as well as an additional smaller group of adolescents whose parents separated between waves 1 and 3 (“prospective separators”; n = 76. Adolescents’ satisfaction with different domains of life (family, education/work, and their general life satisfaction as well as their self-esteem were used as indicators of well-being. A series of multiple regression analyses tested the effects of family structure on well-being at T1 and changes in well-being over time, controlling for various background factors. Furthermore, likely mediation effects of infrequent contact to the non-resident father and economic strain were tested. The findings show (relatively minor effects of parental separation, namely lower well-being among youth1 in single mother families compared to nuclear families. Disadvantages of youth in single mother families could only be partly explained by the higher financial strain generally experienced in these families. Youth in stepfather families reported a similar overall well-being as adolescents in nuclear families, but indicated a greater decrease in family satisfaction over time. Pre-separation disadvantages among prospective separators were limited to greater dissatisfaction with school. Infrequent contact with the non-resident father did not affect adolescents’ well-being. Effects of family structure did not differ between boys and girls, but maternal education moderated the effects of family structure

  16. Switching Monopolar Radiofrequency Ablation Using a Separable Cluster Electrode in Patients with Hepatocellular Carcinoma: A Prospective Study.

    Directory of Open Access Journals (Sweden)

    Jin Woo Choi

    Full Text Available This study was conducted to evaluate the outcomes of multi-channel switching RFA using a separable cluster electrode in patients with HCC.From November 2011 to July 2013, 79 patients with 98 HCCs < 5 cm were enrolled and treated with RFA using a multi-channel switching radiofrequency system and a separable cluster electrode under the guidance of a real-time fusion imaging system. The primary and secondary endpoints were the 3-year local tumor progression (LTP rate and recurrence-free survival (RFS rate, respectively. For post hoc analyses, LTP, RFS, and major complication rates were retrospectively compared with a historical control group treated with RFA using the same radiofrequency system but with multiple internally-cooled electrodes.The technique success rate of the 98 tumors was 100%. Cumulative 1-year, 2-year, and 3-year LTP rates were 3.4%, 6.9%, and 12.4%, respectively. For patient-level data, cumulative 1-year, 2-year, and 3-year RFS rates were 83.9%, 68.6%, and 45.4%, respectively. On post hoc analyses, none of the baseline characteristics showed a significant difference between the separable cluster electrode and multiple internally-cooled electrodes group. Cumulative LTP and RFS rates of the two groups also showed no significant difference (p = 0.401 and p = 0.881, respectively. Finally, major complication rates of the separable cluster electrode group (5.0%, 4/79 and multiple internally-cooled electrodes group (5.9%, 4/74 were also comparable (p = 1.000.Switching monopolar RFA using a separable cluster electrode is a feasible and efficient technique for the treatment of HCCs smaller than 5 cm, providing comparable local tumor control to multiple internally-cooled electrodes.ClinicalTrials.gov NCT02745483.

  17. Numerical studies on the separation performance of liquid- liquid Hydrocyclone for higher water-cut wells

    Science.gov (United States)

    Osei, H.; Al-Kayiem, H. H.; Hashim, F. M.

    2015-12-01

    Liquid-liquid hydrocyclones have nowadays become very useful in the oil industry because of their numerous applications. They can be installed downhole in the case of a well that produces higher water-oil ratios. The design of a liquid-liquid hydrocyclone for such a task is critical and every geometric part of the hydrocyclone has a part to play as far as separation is concerned. This work, through validated numerical technique, investigated the liquid-liquid hydrocyclone performance for the cases of single-inlet and dual-inlets, with different upper cylindrical lengths, specifically, 30mm and 60mm.It was observed that the hydrocyclones with the 30mm upper cylindrical section perform better than the ones with 60 mm upper cylindrical section. It was again noted that, even though higher number of tangential inlets increases the swirl intensity, they have the tendency to break up the oil droplets within the hydrocyclone because of increasing shear and jet flow interaction.

  18. Modified method for bronchial suture by Ramirez Gama compared to separate stitches suture: experimental study

    Directory of Open Access Journals (Sweden)

    Vitor Mayer de Moura

    Full Text Available OBJECTIVE: To experimentally compare two classic techniques described for manual suture of the bronchial stump. METHODS: We used organs of pigs, with isolated trachea and lungs, preserved by refrigeration. We dissected 30 bronchi, which were divided into three groups of ten bronchi each, of 3mm, 5mm, and 7mm, respectively. In each, we performed the suture with simple, separated, extramucosal stitches in five other bronchi, and the technique proposed by Ramirez and modified by Santos et al in the other five. Once the sutures were finished, the anastomoses were tested using compressed air ventilation, applying an endotracheal pressure of 20mmHg. RESULTS: the Ramirez Gama suture was more effective in the bronchi of 3, 5 and 7 mm, and there was no air leak even after subjecting them to a tracheal pressure of 20mmHg. The simple interrupted sutures were less effective, with extravasation in six of the 15 tested bronchi, especially in the angles of the sutures. These figures were not significant (p = 0.08. CONCLUSION: manual sutures of the bronchial stumps were more effective when the modified Ramirez Gama suture was used in the caliber bronchi arms when tested with increased endotracheal pressure.

  19. Should pantomime and gesticulation be assessed separately for their comprehensibility in aphasia? A case study.

    Science.gov (United States)

    van Nispen, Karin; van de Sandt-Koenderman, Mieke; Mol, Lisette; Krahmer, Emiel

    2014-01-01

    Gesticulation (gestures accompanying speech) and pantomime (gestures in the absence of speech) can each be comprehensible. Little is known about the differences between these two gesture modes in people with aphasia. To discover whether there are differences in the communicative use of gesticulation and pantomime in QH, a person with severe fluent aphasia. QH performed two tasks: naming objects and retelling a story. He did this once in a verbal condition (enabling gesticulation) and once in a pantomime condition. For both conditions, the comprehensibility of gestures was analysed in a forced-choice task by naïve judges. Secondly, a comparison was made between QH and healthy controls for the representation techniques used. Pantomimes produced by QH for naming objects were significantly more comprehensible than chance, whereas his gesticulation was not. For retelling a story the opposite pattern was found. When naming objects QH gesticulated much more than did healthy controls. His pantomimes for this task were simpler than those used by the control group. For retelling a story no differences were found. Although QH did not make full use of each gesture modes' potential, both did contribute to QH's comprehensibility. Crucially, the benefits of each mode differed across tasks. This implies that both gesture modes should be taken into account separately in models of speech and gesture production and in clinical practice for different communicative settings. © 2013 Royal College of Speech and Language Therapists.

  20. Preparation, characterization, and performance evaluation of UiO-66 analogues as stationary phase in HPLC for the separation of substituted benzenes and polycyclic aromatic hydrocarbons

    National Research Council Canada - National Science Library

    Weiwei Zhao; Chaoyan Zhang; Zengguang Yan; Youya Zhou; Jianrong Li; Yabo Xie; Liping Bai; Lin Jiang; Fasheng Li

    2017-01-01

    .... Nonetheless, PAHs could be well separated on UiO-67 column. The separation mechanisms of SBs and PAHs on UiO-66 analogues may be involved in the pore size and functional group in the frameworks of UiO-66 analogues...

  1. Study of Separation and Fouling of Reverse Osmosis Membranes during Model Hydrolysate Solution Filtration

    Science.gov (United States)

    Rahni, Mohamed; Marinova, Mariya; Chadjaa, Hassan; Savadogo, Oumarou

    2017-01-01

    Prehydrolysate, a dilute solution consisting mainly of pentoses, hexoses, and lesser quantities of organic acids, furfural and phenolics, is generated in the Kraft dissolving pulp process. An obstacle facing the valorization of the solution in hemicellulose biorefineries, by conversion of the sugars into bioproducts such as furfural, is the low sugar concentration. Membrane filtration is typically proposed in several hemicellulose based biorefineries for concentrating the solution, although they are usually generated using different wood species, pretreatment methods, and operating conditions. However, the chemical composition of the solutions is generally not considered. Also, the combined effect of composition and operating conditions is rarely investigated for biorefinery applications. The purpose of this work was to determine the impact of the prehydrolysate composition and operating parameters on the component separation and permeate flux during membrane filtration. Using model prehydrolysate solutions, two commercial reverse osmosis (RO) membranes were screened, and one was selected for use, based on its higher sugar and acetic acid retention. A Taguchi L18 experimental design array was then applied to determine the dominant parameters and limiting factors. Results showed that the feed pressure and temperature have the highest impact on permeate flux, but the least effect on sugar retention. Further experiments to quantify flux decline, due to fouling and osmotic pressure, showed that furfural has the highest membrane fouling tendency, and can limit the lifetime of the membrane. Regeneration of the membrane by cleaning with a sodium hydroxide solution is also effective for reversing fouling. It has been demonstrated that RO can efficiently and sustainably concentrate wood prehydrolysate. PMID:29244761

  2. Separation and purification of soluble polymers and cell wall fractions from wheat, rye and hull less barley endosperm flours for structure-nutrition studies.

    Science.gov (United States)

    Comino, Penny; Shelat, Kinnari; Collins, Helen; Lahnstein, Jelle; Gidley, Michael J

    2013-12-11

    The nutritional values associated with the cell walls of cereal endosperm flours are due to a combination of solubilized arabinoxylan and (1-3,1-4)-β-d-glucan as well as residual nonsolubilized cell wall material. In order to investigate structure-nutrition relationships, an appropriate method for the complete functional and structural characterization of cell wall polysaccharides in various cereal endosperm flours is described. This involves the separation of soluble polymers and the residual cell wall fraction without using organic solvents, and the fractionation of soluble polymers into arabinoxylan- and (1-3,1-4)-β-d-glucan-rich fractions for subsequent analysis. This methodology is applied to endosperm flours from wheat, hull-less barley and rye, and could be extended to include studies on the effects of food processing with respect to yield and characteristics of the three fractions in order to better understand the structural basis for nutritional functionality.

  3. 40 CFR 792.135 - Physical and chemical characterization studies.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Physical and chemical characterization studies. 792.135 Section 792.135 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) GOOD LABORATORY PRACTICE STANDARDS Protocol for and Conduct of A Study § 792.135 Physical and chemical...

  4. Study of β-galactosidase activity in Lactobacilli separated from milk and cheese by biochemical and PCR methods

    Directory of Open Access Journals (Sweden)

    zohre bahadori

    2010-04-01

    Full Text Available In some people the inadequate amount of Beta-galactosidase enzyme, in layer of villous epithelium of the small intestine, causes the disorder of lactose intolerance. This examination was done to observe the existence of Beta-galactosidase enzyme that is produced by separated Lactobacillus from samples of dairy products (milk and cheese. Materials and Methods: Pasteurized and local samples of milk and cheese were perchased from Lorestan,Ilam and Hamedan provinces. By keeping the samples in MRS media and according to some phenotypic features, Lactobacillus were recognized. Through X-gal and ONPG methods the ability of Beta-galactosidase production was examined.By PCR method the existence of Beta- galactosidase gene was studied. Results: Among studied samples 131 Lactobacillus(13 strains were separated,which in media containing X-gal green colonies were acquired(but in different occasions.Green colonies demonstrated the existence of Beta-galactosidase enzyme in the media. In ONPG test, all Lactobacillus indicated the Beta-galactosidase activiy that in 25 strains the amount of enzyme was more than the others, (also the greatest amount of enzyme in a strain of Lactobacillus delberoki separated from Kermanshah local cheese was measured by 2010 miller unit /ml. In a standard strain of Lactobacillus Plantarum(RITCC 1273 and 29 strains of separated Lactobacillus Plantarum the 399bp band of Beta-galactosidase gene was examined and confirmed through PCR method. Conclusion: In dairy products, using Lactobacilli which contain Beta-galactosidase enzyme,we can help the people who lack lactose tolerance. Meanwhile those Lactobacillus that creat more Beta-galactosidase are more suitable to use.

  5. HRS Separator

    CERN Multimedia

    2016-01-01

    Footage of the 90 and 60 degree ISOLDE HRS separator magnets in the HRS separator zone. In the two vacuum sectors HRS20 and HRS30 equipment such as the HRS slits SL240, the HRS faraday cup FC300 and wiregrid WG210 can be spotted. Vacuum valves, turbo pumps, beamlines, quadrupoles, water and compressed air connections, DC and signal cabling can be seen throughout the video. The HRS main and user beamgate in the beamline between MAG90 and MAG60 and its switchboxes as well as all vacuum bellows and flanges are shown. Instrumentation such as the HRS scanner unit 482 / 483, the HRS WG470 wiregrid and slits piston can be seen. The different quadrupoles and supports are shown as well as the RILIS guidance tubes and installation at the magnets and the different radiation monitors.

  6. GPS Separator

    CERN Multimedia

    2016-01-01

    Footage of the 70 degree ISOLDE GPS separator magnet MAG70 as well as the switchyard for the Central Mass and GLM (GPS Low Mass) and GHM (GPS High Mass) beamlines in the GPS separator zone. In the GPS20 vacuum sector equipment such as the long GPS scanner 482 / 483 unit, faraday cup FC 490, vacuum valves and wiregrid piston WG210 and WG475 and radiation monitors can also be seen. Also the RILIS laser guidance and trajectory can be seen, the GPS main beamgate switch box and the actual GLM, GHM and Central Beamline beamgates in the beamlines as well as the first electrostatic quadrupoles for the GPS lines. Close up of the GHM deflector plates motor and connections and the inspection glass at the GHM side of the switchyard.

  7. Separation system

    Science.gov (United States)

    Rubin, Leslie S.

    1986-01-01

    A separation system for dewatering radioactive waste materials includes a disposal container, drive structure for receiving the container, and means for releasably attaching the container to the drive structure. Separation structure disposed in the container adjacent the inner surface of the side wall structure retains solids while allowing passage of liquids. Inlet port structure in the container top wall is normally closed by first valve structure that is centrifugally actuated to open the inlet port and discharge port structure at the container periphery receives liquid that passes through the separation structure and is normally closed by second valve structure that is centrifugally actuated to open the discharge ports. The container also includes coupling structure for releasable engagement with the centrifugal drive structure. Centrifugal force produced when the container is driven in rotation by the drive structure opens the valve structures, and radioactive waste material introduced into the container through the open inlet port is dewatered, and the waste is compacted. The ports are automatically closed by the valves when the container drum is not subjected to centrifugal force such that containment effectiveness is enhanced and exposure of personnel to radioactive materials is minimized.

  8. Using Environment-Sensitive Fluorescent Probes to Characterize Liquid-Liquid Phase Separation in Supersaturated Solutions of Poorly Water Soluble Compounds.

    Science.gov (United States)

    Raina, Shweta A; Alonzo, David E; Zhang, Geoff G Z; Gao, Yi; Taylor, Lynne S

    2015-11-01

    Highly supersaturated aqueous solutions of poorly soluble compounds can undergo liquid-liquid phase separation (LLPS) when the concentration exceeds the "amorphous solubility". This phenomenon has been widely observed during high throughput screening of new molecular entities as well as during the dissolution of amorphous solid dispersions. In this study, we have evaluated the use of environment-sensitive fluorescence probes to investigate the formation and properties of the non-crystalline drug-rich aggregates formed in aqueous solutions as a result of LLPS. Six different environment-sensitive fluorophores were employed to study LLPS in highly supersaturated solutions of several model compounds, all dihydropyridine derivatives. Each fluoroprobe exhibited a large hypsochromic shift with decreasing environment polarity. Upon drug aggregate formation, the probes partitioned into the drug-rich phase and exhibited changes in emission wavelength and intensity consistent with sensing a lower polarity environment. The LLPS onset concentrations determined using the fluorescence measurements were in good agreement with light scattering measurements as well as theoretically estimated amorphous solubility values. Environment-sensitive fluorescence probes are useful to help understand the phase behavior of highly supersaturated aqueous solutions, which in turn is important in the context of developing enabling formulations for poorly soluble compounds.

  9. Approaches for the estimation of timescales in nonlinear dynamical systems: Timescale separation in enzyme kinetics as a case study.

    Science.gov (United States)

    Shoffner, S K; Schnell, Santiago

    2017-05-01

    The derivation of timescales is frequently introduced as an art form in papers and textbooks. The best scaling techniques require the application of physical intuition to identify dimensionless variables that are one unit order of magnitude and small parameters, which can simplify nonlinear differential equations. However, physical intuition requires prior knowledge of the solution to the dynamical systems under investigation. There are problems where the application of physical intuition is not straightforward. Therefore, it is necessary to apply mathematical techniques to estimate scales for the separation of timescales and simplification. In this review, we present three mathematical techniques - determination of pairwise balances, principle of minimum simplification and scaling by inverse rates - to scale dynamical systems with limited prior knowledge of model behavior. We illustrate the application of these techniques with the Michaelis-Menten reaction, which is widely studied to introduce scaling and simplification techniques in textbooks. We show that the pairwise balance approach, though commonly introduced as a method for nondimensionalization, can fail to derive a separation between timescales. The other techniques we review here can be applied to a number of dynamical systems, where the separation of timescales can lead to the simplification of a complex nonlinear problem. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Enantiomeric separation of tapentadol by capillary electrophoresis--study of chiral selectivity manipulation by various types of cyclodextrins.

    Science.gov (United States)

    Znaleziona, Joanna; Fejős, Ida; Ševčík, Juraj; Douša, Michal; Béni, Szabolcs; Maier, Vítězslav

    2015-02-01

    The chiral recognition of the centrally acting analgesic agent tapentadol and its isomers with various cyclodextrins (CDs) was studied by capillary electrophoresis, focusing on the migration order of four stereoisomers. In the case of non-charged hydroxypropylated CDs (2-hydroxypropyl-β-CD, 2-hydroxypropyl-γ-CD) the beta derivative was able to discriminate the S,R- and R,S-isomers in acidic background electrolyte, whereas the gamma allowed the separation of S,S- and R,R-tapentadol, respectively. Dual CD system containing both hosts was used to separate all of four isomers. Negatively charged sulfated-α-CD at 1.0% (w/v) concentration in 100mM sodium borate buffer (pH 9.5) was capable of separating the isomers with favorable enantiomer migration order and the optimized method was able to determine 0.15% of chiral impurities of tapentadol in the presence of the last migrating clinically important R,R-isomer. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Molecular Dynamics Study of the Separation Behavior at the Interface between PVDF Binder and Copper Current Collector

    Directory of Open Access Journals (Sweden)

    Seungjun Lee

    2016-01-01

    Full Text Available In Li-ion batteries, the mechanical strengths at the interfaces of binder/particle and binder/current collector play an important role in maintaining the mechanical integrity of the composite electrode. In this work, the separation behaviors between polyvinylidene fluoride (PVDF binders and copper current collectors are studied in the opening and sliding modes using molecular dynamics (MD simulations. The simulation shows that the separation occurs inside the PVDF rather than at the interface due to the strong adhesion between PVDF and copper. This fracture behavior is different from the behavior of the PVDF/graphite basal plane that shows a clear separation at the interface. The results suggest that the adhesion strength of the PVDF/copper is stronger than that of the PVDF/graphite basal plane. The methodology used in MD simulation can directly evaluate the adhesion strength at the interfaces of various materials between binders, substrates, and particles at the atomic scales. The proposed method can therefore provide a guideline for the design of the electrode in order to enhance the mechanical integrity for better battery performance.

  12. Separate tools or tool kits: an exploratory study of engineers' preferences

    NARCIS (Netherlands)

    Vliegen, Ingrid; Kleingeld, P.A.M.; van Houtum, Geert-Jan

    2010-01-01

    This paper describes an exploratory study of aspects that should be taken into consideration when optimizing tool kits, i.e. cases containing sets of tools that are used by service engineers for corrective maintenance. The study was carried out among service engineers of an Original Equipment

  13. Theoretical Study of the Charge-Transfer State Separation within Marcus Theory

    DEFF Research Database (Denmark)

    Volpi, Riccardo; Nassau, Racine; Nørby, Morten Steen

    2016-01-01

    We study, within Marcus theory, the possibility of the charge-transfer (CT) state splitting at organic interfaces and a subsequent transport of the free charge carriers to the electrodes. As a case study we analyze model anthracene-C60 interfaces. Kinetic Monte Carlo (KMC) simulations on the cold...

  14. Mechanistic Studies Of Combustion And Structure Formation During Combustion Synthesis Of Advanced Materials: Phase Separation Mechanism For Bio-Alloys

    Science.gov (United States)

    Varma, A.; Lau, C.; Mukasyan, A.

    2003-01-01

    Among all implant materials, Co-Cr-Mo alloys demonstrate perhaps the most useful balance of resistance to corrosion, fatigue and wear, along with strength and biocompatibility [1]. Currently, these widely used alloys are produced by conventional furnace technology. Owing to high melting points of the main alloy elements (e.g. Tm.p.(Co) 1768 K), high-temperature furnaces and long process times (several hours) are required. Therefore, attempts to develop more efficient and flexible methods for production of such alloys with superior properties are of great interest. The synthesis of materials using combustion phenomena is an advanced approach in powder metallurgy [2]. The process is characterized by unique conditions involving extremely fast heating rates (up to 10(exp 6 K/s), high temperatures (up to 3500 K), and short reaction times (on the order of seconds). As a result, combustion synthesis (CS) offers several attractive advantages over conventional metallurgical processing and alloy development technologies. The foremost is that solely the heat of chemical reaction (instead of an external source) supplies the energy for the synthesis. Also, simple equipment, rather than energy-intensive high-temperature furnaces, is sufficient. This work was devoted to experiments on CS of Co-based alloys by utilizing thermite (metal oxide-reducing metal) reactions, where phase separation subsequently produces materials with tailored compositions and properties. Owing to high reaction exothermicity, the CS process results in a significant increase of temperature (up to 3000 C), which is higher than melting points of all products. Since the products differ in density, phase separation may be a gravitydriven process: the heavy (metallic phase) settles while the light (slag) phase floats. The goal was to determine if buoyancy is indeed the major mechanism that controls phase segregation.

  15. Characterization and in vitro studies on anticancer activity of ...

    African Journals Online (AJOL)

    Characterization of exopolymer shows the presence of brominated compound responsible for cytotoxicity on lung cancer cell line (A549) on XTT assay. An in vitro study of bacterial exopolymer shows the presence of cytotoxic effects on cell lines. Further, active compound in exopolymer responsible for cytotoxicity has to be ...

  16. Characterization and in vitro studies on anticancer activity of ...

    African Journals Online (AJOL)

    SAM

    2014-05-21

    May 21, 2014 ... S13. Characterization of exopolymer shows the presence of brominated compound responsible for cytotoxicity on lung cancer cell line (A549) on XTT assay. An in vitro study of bacterial exopolymer shows the presence of cytotoxic effects on cell lines. Further, active compound in exopolymer responsible for ...

  17. Antenna coupling study for ICWC plasma characterization in TEXTOR

    Indian Academy of Sciences (India)

    ... Pramana – Journal of Physics; Volume 80; Issue 1. Antenna coupling study for ICWC plasma characterization in TEXTOR. Manash Kumar Paul A Lyssoivan R Koch G Van Wassenhove M Vervier G Bertschinger R Laengner B Unterberg G Sergienko V Philipps T Wauters the TEXTOR Team. Research Articles Volume 80 ...

  18. Synthesis, characterization and ion recognition studies of lower rim ...

    Indian Academy of Sciences (India)

    An amido-linked rhodamine conjugate of calix[4]arene, L has been synthesized and characterized. Metal ion recognition properties of L have been studied by emission and absorption techniques with 14 different metal ions including the transition ones. Results show that, L exhibits ratiometric emission intensity towards ...

  19. Geometric multiaxial representation of N -qubit mixed symmetric separable states

    Science.gov (United States)

    SP, Suma; Sirsi, Swarnamala; Hegde, Subramanya; Bharath, Karthik

    2017-08-01

    The study of N -qubit mixed symmetric separable states is a longstanding challenging problem as no unique separability criterion exists. In this regard, we take up the N -qubit mixed symmetric separable states for a detailed study as these states are of experimental importance and offer an elegant mathematical analysis since the dimension of the Hilbert space is reduced from 2N to N +1 . Since there exists a one-to-one correspondence between the spin-j system and an N -qubit symmetric state, we employ Fano statistical tensor parameters for the parametrization of the spin-density matrix. Further, we use a geometric multiaxial representation (MAR) of the density matrix to characterize the mixed symmetric separable states. Since the separability problem is NP-hard, we choose to study it in the continuum limit where mixed symmetric separable states are characterized by the P -distribution function λ (θ ,ϕ ) . We show that the N -qubit mixed symmetric separable states can be visualized as a uniaxial system if the distribution function is independent of θ and ϕ . We further choose a distribution function to be the most general positive function on a sphere and observe that the statistical tensor parameters characterizing the N -qubit symmetric system are the expansion coefficients of the distribution function. As an example for the discrete case, we investigate the MAR of a uniformly weighted two-qubit mixed symmetric separable state. We also observe that there exists a correspondence between the separability and classicality of states.

  20. Characterization of sunflower oils obtained separately by pressing and subsequent solvent extraction from a new line of seeds rich in phytosterols and conventional seeds

    Directory of Open Access Journals (Sweden)

    Aguirre Marta R.

    2014-11-01

    Full Text Available In this study we evaluate the chemical composition of sunflower oils obtained separately by pressing and subsequent solvent extraction from a new seeds rich in phytosterols (IASP-18 and conventional seeds (HA-89. Results have shown that the total content of oil was much lower in the IASP-18 (18.1% than in the conventional (37.5% seeds. The extraction yield obtained by pressing was as low as 3% in the IASP-18 seeds and 37.5% in HA-89, while in the solvent extraction it was of the same order (~18 wt% on seeds extracted by pressing for the two types of seeds. No significant changes in the fatty acid composition were found between the oils extracted by the two procedures, but the pressed oils presented significantly lower acidity and larger content of the unsaponifiable fraction. Expressed as free sterols, the total sterols were 37–38% more concentrated in the oils extracted with solvent, reaching amounts of 13 700 and 6500 mg/kg in the IASP-18 and HA-89 oils, respectively. No substantial differences were found in the composition of total sterols analysed as free sterols between the oils extracted with the two procedures, but the contents of free sterols and sterol glycosides were much higher in the oils extracted with solvent.

  1. Gas separating

    Science.gov (United States)

    Gollan, A.

    1988-03-29

    Feed gas is directed tangentially along the non-skin surface of gas separation membrane modules comprising a cylindrical bundle of parallel contiguous hollow fibers supported to allow feed gas to flow from an inlet at one end of a cylindrical housing through the bores of the bundled fibers to an outlet at the other end while a component of the feed gas permeates through the fibers, each having the skin side on the outside, through a permeate outlet in the cylindrical casing. 3 figs.

  2. Flow Separation

    Science.gov (United States)

    1975-11-01

    perfomanoas que oette oirconstance peut entrainer, soit encore, d’un point de vue plus fondamental par la recherche dM phenomknas qui caracterisent 1M...dtfoolleoent, dont le m^canlsme de formation eat en tout point sen- blable h celui qui a etc döcrit § 2.2. XL se caracterise par la presence d’une onde...during orbital maneuvers with the Reaction Control System (RCS) and later plume induced separation leading to aerodynamic heating and control problems

  3. WRAP Module 1 sampling strategy and waste characterization alternatives study

    Energy Technology Data Exchange (ETDEWEB)

    Bergeson, C.L.

    1994-09-30

    The Waste Receiving and Processing Module 1 Facility is designed to examine, process, certify, and ship drums and boxes of solid wastes that have a surface dose equivalent of less than 200 mrem/h. These wastes will include low-level and transuranic wastes that are retrievably stored in the 200 Area burial grounds and facilities in addition to newly generated wastes. Certification of retrievably stored wastes processing in WRAP 1 is required to meet the waste acceptance criteria for onsite treatment and disposal of low-level waste and mixed low-level waste and the Waste Isolation Pilot Plant Waste Acceptance Criteria for the disposal of TRU waste. In addition, these wastes will need to be certified for packaging in TRUPACT-II shipping containers. Characterization of the retrievably stored waste is needed to support the certification process. Characterization data will be obtained from historical records, process knowledge, nondestructive examination nondestructive assay, visual inspection of the waste, head-gas sampling, and analysis of samples taken from the waste containers. Sample characterization refers to the method or methods that are used to test waste samples for specific analytes. The focus of this study is the sample characterization needed to accurately identify the hazardous and radioactive constituents present in the retrieved wastes that will be processed in WRAP 1. In addition, some sampling and characterization will be required to support NDA calculations and to provide an over-check for the characterization of newly generated wastes. This study results in the baseline definition of WRAP 1 sampling and analysis requirements and identifies alternative methods to meet these requirements in an efficient and economical manner.

  4. Studies in matter antimatter separation and in the origin of lunar magnetism

    Science.gov (United States)

    Barker, W. A.; Greeley, R.; Parkin, C.; Aggarwal, H.; Schultz, P.

    1975-01-01

    A progress report, covering lunar and planetary research is introduced. Data cover lunar ionospheric models, lunar and planetary geology, and lunar magnetism. Wind tunnel simulations of Mars aeolian problems and a comparative study of basaltic analogs of Lunar and Martial volcanic features was discussed.

  5. A fine coal circuitry study using column flotation and gravity separation. Quarterly report, 1 December 1994--28 February 1995

    Energy Technology Data Exchange (ETDEWEB)

    Honaker, R.Q. [Southern Illinois Univ., Carbondale, IL (United States); Reed, S. [Kerr-McGee Coal Corp., Oklahoma City, OK (United States)

    1995-12-31

    Column flotation provides excellent recovery of ultrafine coal while producing low ash content concentrates. However, column flotation is not efficient for treating fine coal containing significant amounts of mixed-phase particles. Fortunately, enhanced gravity separation has proved to have the ability to treat the mixed-phased particles more effectively. A disadvantage of gravity separation is that ultrafine clay particles are not easily rejected. Thus, a combination of these two technologies may provide a circuit that maximizes both the ash and sulfur rejection that can be achieved by physical coal cleaning while maintaining a high energy recovery. This project is studying the potential of using different combinations of gravity separators, i.e., a Floatex hydrosizer and a Falcon Concentrator, and a proven flotation column, which will be selected based on previous studies by the principle investigator. During this reporting period, an in-plant Box-Behnken test program of the Floatex hydrosizer has been conducted at Kerr-McGee`s Galatia preparation plant. The results have shown that the Floatex hydrosizer can be successfully used to reject most of coarser ({plus}100 mesh) pyrite and mineral matter in the coal stream to the plant. With a single operation, ash rejection of 63% and total sulfur rejection of 43% have been achieved while maintaining a combustible recovery as high as 90.5%. A long term duration test under the optimum operating conditions determined from Box-Behnken test results has also been conducted. The feed samples for the following enhanced gravity - column flotation studies, which will be carried out in the next reporting period, have been collected.

  6. Separation and identification of petroporphyrins extracted from the oil shales of Tarfaya: geochemical study

    Energy Technology Data Exchange (ETDEWEB)

    Doukkali, A.; Saoiabi, A.; Zrineh, A.; Hamad, M.; Ferhat, M.; Barbe, J.M.; Guilard, R. [Universite Mohammed V Agdal, Rabat (Morocco). Laboratoire de Chimie Physique Generale, Faculte des Sciences de Rabat

    2002-03-01

    Vanadyl and nickel porphyrins were isolated from the oil shales of Tarfaya (Morocco) by extraction followed by column chromatography. The ratios and characteristics of these porphyrin complexes were essentially obtained on the basis of UV-visible and mass spectrometry data. Geochemical information could be drawn from these data. The nature and the contents of the metals coordinated and non-coordinated to porphyrin systems were also determined in this study. 30 refs., 3 figs., 3 tabs.

  7. Cyclic Carbonation Calcination Studies of Limestone and Dolomite for CO2 Separation From Combustion Flue Gases

    OpenAIRE

    Sivalingam, S.;Gleis, S.;Hartmut, S.;Yrjas, P.;Hupa, M.

    2017-01-01

    Naturally occurring limestone and dolomite samples, originating from different geographical locations, were tested as potential sorbents for carbonation/calcination based CO2 capture from combustion flue gases. Samples have been studied in a thermogravimetric analyzer under simulated flue gas conditions at three calcination temperatures,viz., 750textdegreeC, 875textdegreeC, and 930textdegreeC for four carbonation calcination reaction (CCR) cycles. The dolomite sample exhibited the highest rat...

  8. Comparison in dietary patterns derived for the Canadian Newfoundland and Labrador population through two time-separated studies.

    Science.gov (United States)

    Chen, Zhi; Wang, Peizhong Peter; Shi, Lian; Zhu, Yun; Liu, Lin; Gao, Zhiwei; Woodrow, Janine; Roebothan, Barbara

    2015-08-01

    While a dietary pattern is often believed to be stable in a population, there is limited research assessing its stability over time. The objective of this study is to explore and compare major dietary patterns derived for the Canadian subpopulation residing in Newfoundland and Labrador (NL), through two time-separated studies using an identical method. In this study, we derived and compared the major dietary patterns derived from two independent studies in the NL adult population. The first study was based on the healthy controls from a large population-based case-control study (CCS) in 2005. The second was from a food-frequency questionnaire validation project (FFQVP) conducted in 2012. In both studies, participants were recruited in the same manner and dietary information was collected by an identical self-administered food-frequency questionnaire (FFQ). Exploratory common factor analysis was conducted to identify major dietary patterns. A comparison was conducted between the two study populations. Four major dietary patterns were identified: Meat, Vegetables/fruits, Fish, and Grains explaining 22%, 20%, 12% and 9% variance respectively, with a total variance of 63%. Three major dietary patterns were derived for the controls of the CCS: Meat, Plant-based diet, and Fish explaining 24%, 20%, and 10% variance respectively, with a total variance of 54%. As the Plant-based diet pattern derived for the CCS was a combination of the Vegetables/fruits and Grains patterns derived for the FFQVP, no considerable difference in dietary patterns was found between the two studies. A comparison between two time-separated studies suggests that dietary patterns of the NL adult population have remained reasonably stable over almost a decade.

  9. Experimental and numerical study of smoke propagation through a vent separating two mechanically ventilated rooms

    Energy Technology Data Exchange (ETDEWEB)

    Audouin, Laurent; Pretrel, Hugues; Vaux, Samuel [Institut de Radioprotection et de Surete Nucleaire (IRSN), Saint Paul Lez Durance (France)

    2015-12-15

    The paper presents an experimental and numerical study about smoke propagation through a horizontal opening between two superposed compartments, as can be encountered in nuclear installations, in case of a fire taking place in the lower room. The experimental configuration proposed in this study consists in two rooms mechanically ventilated and connected each other by a horizontal opening. The fire source is simulated by a propane burner located in the lower room. The inlet ventilation duct is located in the lower room and the exhaust ventilation duct is located in the upper room. For such experimental configuration, several flow regimes at the horizontal opening connecting the two rooms can be encountered depending on the fire power, the opening size (diameter, depth) and the ventilation set-up (location of inlet/outlet ducts, flow rate). Indeed, flow at the opening is governed by buoyant forces due to the hot gases produced by the fire, the inertia effect due to the forced ventilation and the momentum effect due to smoke flow nearby the horizontal opening (for instance, ceiling jet or thermal plume from fire). Consequently, such complex mixed (natural/ forced) convective flows are still a challenge for CFD fire codes to make properly calculations of these experimental scenarios. The objective of this paper is to assess the capability of ISIS code (CFD) to simulate the behaviour of smoke propagation inside these two superposed compartments. Results of this study are presented with details (especially, thermal stratification and flow rates through the horizontal vent) and are discussed thoroughly.

  10. Comparative Study of Coal and Biomass Co-Combustion With Coal Burning Separately Through Emissions Analysis

    Directory of Open Access Journals (Sweden)

    Mohammad Siddique

    2016-06-01

    Full Text Available Appropriate eco-friendly methods to mitigate the problem of emissions from combustion of fossil fuel are highly demanded. The current study was focused on the effect of using coal & coal-biomass co-combustion on the gaseous emissions. Different biomass' were used along with coal. The coal used was lignite coal and the biomass' were tree waste, cow dung and banana tree leaves. Various ratios of coal and biomass were used to investigate the combustion behavior of coal-biomass blends and their emissions. The study revealed that the ratio of 80:20 of coal (lignite-cow dung and 100% banana tree leaves emits less emissions of CO, CO2, NOx and SO2 as compared to 100% coal. Maximum amount of CO emissions were 1510.5 ppm for banana tree waste and minimum amount obtained for lakhra coal and cow dung manure (70:30 of 684.667 ppm. Maximum percentage of SO2 (345.33 ppm was released from blend of lakhra coal and tree leaves (90:10 and minimum amount of SO2 present in samples is in lakhra coal-banana tree waste (80:20. The maximum amount of NO obtained for banana tree waste were 68 ppm whereas maximum amount of NOx was liberated from lakhra coal-tree leaves (60:40 and minimum amount from cow dung manure (30.83 ppm. The study concludes that utilization of biomass with coal could make remedial action against environment pollution.

  11. Molecular modelling study for chiral separation of equol enantiomers by β-cyclodextrin

    Science.gov (United States)

    Alvira, E.; García, J. I.; Mayoral, J. A.

    1999-01-01

    The intermolecular forces responsible for complexation of equol, a chiral molecule, with β-cyclodextrin are determined using a molecular modelling study. The differential interactions between each enantiomer and the chiral host give rise to different configurations for the corresponding inclusion complexes which give rise to enantiodifferentiation. The van der Waals term is the main contributor to the total potential; however, the electrostatic term influences the enantioselectivity significantly since it establishes a difference between the most stable position of R- and S-equol and hence between their energies. A statistical analysis of the minimized energies is carried out to determine that R-equol is more retained than S-equol.

  12. Molecular Modeling Study of Chiral Separation and Recognition Mechanism of β-Adrenergic Antagonists by Capillary Electrophoresis

    Directory of Open Access Journals (Sweden)

    Yifeng Chai

    2012-01-01

    Full Text Available Chiral separations of five β-adrenergic antagonists (propranolol, esmolol, atenolol, metoprolol, and bisoprolol were studied by capillary electrophoresis using six cyclodextrins (CDs as the chiral selectors. Carboxymethylated-β-cyclodextrin (CM-β-CD exhibited a higher enantioselectivity power compared to the other tested CDs. The influences of the concentration of CM-β-CD, buffer pH, buffer concentration, temperature, and applied voltage were investigated. The good chiral separation of five β-adrenergic antagonists was achieved using 50 mM Tris buffer at pH 4.0 containing 8 mM CM-β-CD with an applied voltage of 24 kV at 20 °C. In order to understand possible chiral recognition mechanisms of these racemates with CM-β-CD, host-guest binding procedures of CM-β-CD and these racemates were studied using the molecular docking software Autodock. The binding free energy was calculated using the Autodock semi-empirical binding free energy function. The results showed that the phenyl or naphthyl ring inserted in the hydrophobic cavity of CM-β-CD and the side chain was found to point out of the cyclodextrin rim. Hydrogen bonding between CM-β-CD and these racemates played an important role in the process of enantionseparation and a model of the hydrogen bonding interaction positions was constructed. The difference in hydrogen bonding formed with the –OH next to the chiral center of the analytes may help to increase chiral discrimination and gave rise to a bigger separation factor. In addition, the longer side chain in the hydrophobic phenyl ring of the enantiomer was not beneficial for enantioseparation and the chiral selectivity factor was found to correspond to the difference in binding free energy.

  13. Transition Metal Polypyridine Complexes: Studies of Mediation in Dye-Sensitized Solar Cells and Charge Separation

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, C. Michael [Colorado State Univ., Fort Collins, CO (United States). Dept. of Chemistry; Prieto, Amy L. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Chemistry

    2017-02-08

    The Elliott group has long been supported by DOE for studies of cobalt(II/III) trisbypiridine (DTB) mediator complexes in dye sensitized solar cells. Previous work demonstrated that Co(II/III) chemistry is sensitive to the environment, showing unprecedented electrode-surface and electrolyte dependant voltammetry. In electrolytes that have large lipophilic cations, voltammetry of the [Co(DTB)3]2+/3+ couple is nearly Nernstian in appearance on nominally oxide-free metal surfaces. In contrast, on semiconductor electrodes in electrolytes with small, hard cations such as Li+, the electron transfer rates are so slow that it is difficult to measure any Faradaic current even at overpotentials of ±1 V. These studies are of direct relevance to the operation of cobalt-based mediators in solar cells. The research has also shown that these mediators are compatible with copper phenantroline based dyes, in contrast to I- due to the insolubility of CuI.

  14. Molecular modelling study for chiral separation of equol enantiomers by {beta}-cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Alvira, E. [Departamento de Fisica Fundamental y Experimental, Universidad de La Laguna, 38206 La Laguna (Spain); Garcia, J.I.; Mayoral, J.A. [Instituto de Ciencia de Materiales de Aragon, Facultad de Ciencias. Universidad de Zaragoza, 50009 Zaragoza (Spain)

    1999-01-01

    The intermolecular forces responsible for complexation of equol, a chiral molecule, with {beta}-cyclodextrin are determined using a molecular modelling study. The differential interactions between each enantiomer and the chiral host give rise to different configurations for the corresponding inclusion complexes which give rise to enantiodifferentiation. The van der Waals term is the main contributor to the total potential; however, the electrostatic term influences the enantioselectivity significantly since it establishes a difference between the most stable position of R- and S-equol and hence between their energies. A statistical analysis of the minimized energies is carried out to determine that R-equol is more retained than S-equol. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  15. Separating neural activity associated with emotion and implied motion: An fMRI study.

    Science.gov (United States)

    Kolesar, Tiffany A; Kornelsen, Jennifer; Smith, Stephen D

    2017-02-01

    Previous research provides evidence for an emo-motoric neural network allowing emotion to modulate activity in regions of the nervous system related to movement. However, recent research suggests that these results may be due to the movement depicted in the stimuli. The purpose of the current study was to differentiate the unique neural activity of emotion and implied motion using functional MRI. Thirteen healthy participants viewed 4 sets of images: (a) negative stimuli implying movement, (b) negative stimuli not implying movement, (c) neutral stimuli implying movement, and (d) neutral stimuli not implying movement. A main effect for implied motion was found, primarily in regions associated with multimodal integration (bilateral insula and cingulate), and visual areas that process motion (bilateral middle temporal gyrus). A main effect for emotion was found primarily in occipital and parietal regions, indicating that emotion enhances visual perception. Surprisingly, emotion also activated the left precentral gyrus, a motor region. These results demonstrate that emotion elicits activity above and beyond that evoked by the perception of implied movement, but that the neural representations of these characteristics overlap. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  16. Thermodynamic Study of Racemic Ibuprofen Separation by Liquid Chromatography Using Cellulose-Based Stationary Phase

    Directory of Open Access Journals (Sweden)

    Wilson M. Ferrari

    2016-01-01

    Full Text Available Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID, also known for its significant antipyretic and analgesic properties. This chiral drug is commercialized in racemic form; however, only S-(+-ibuprofen has clinical activities. In this paper the effect of temperature change (from 288.15 to 308.15 K on the ibuprofen resolution was studied. A column (250×4.6 mm packed with tris(3,5-dimethylphenylcarbamate was used to obtain the thermodynamic parameters, such as enthalpy change (ΔH, entropy change (ΔS, variation enthalpy change (ΔΔH, variation entropy change (ΔΔS, and isoenantioselective temperature (Tiso. The mobile phase was a combination of hexane (99%, isopropyl alcohol (1%, and TFA (0.1%, as an additive. The conditions led to a selectivity of 1.20 and resolution of 4.55. The first peak, R-(−-ibuprofen, presented an enthalpy change of 7.21 kJ/mol and entropy change of 42.88 kJ/K·mol; the last peak, S-(+-ibuprofen, has an enthalpy change of 8.76 kJ/mol and 49.40 kJ/K·mol of entropy change.

  17. Application of process simulators in chemical engineering process design -natural gas separation plant case study

    Directory of Open Access Journals (Sweden)

    Stevanović Dimitrije Ž.

    2014-01-01

    Full Text Available Software for chemical processes modeling and simulation, in the past few decades, play an important role in the development of chemical-process industry with their growing capabilities and wide range of application. Usage of process simulators in Serbia for the process design is very limited. This paper gives a brief overview of the numerous process simulators that are used in the chemical-process industry today. The conceptual design is responsible for most of the investment costs in chemical process industry. Importance of precise design on preliminary level is obvious. Wrong decisions made at the conceptual level could be carried out throughout the chain in process design to the detailed design procedures and procurement of equipment. Although preliminary design phase comprises only about 2% of the total cost of the project, it contributes significantly to the reduction of cost of the project by more than 30%. Therefore process simulators play important role in elimination of unnecessary errors in basic process design. Here is also shown a case study of parallel process simulated in different process simulators which tests the results, the reliability and usefulness of these programs in solving specific engineering tasks. Comparison of given simulation results confirm that the modern process simulators are at high level of confidence, no matter they are based on different models, equations, methods, operations, interfaces or data bases. Usage of software speeds up the arrival of optimized solution during the design and the operational procedures. Therefore software have significant impact on reducing time of pre-project phase such as research, conceptual design, and proving project abilities. It’s development lead to faster commercialization of industrial ideas. [Projekat Ministartsva nauke Republike Srbije, br. TR 34009

  18. A new classification paradigm of extracellular polymeric substances (EPS) in activated sludge: separation and characterization of exopolymers between floc level and microcolony level.

    Science.gov (United States)

    Wang, Bin-Bin; Chang, Qing; Peng, Dang-Cong; Hou, Yin-Ping; Li, Hui-Juan; Pei, Li-Ying

    2014-11-01

    Extracellular polymeric substances (EPS) play a crucial role in the formation of activated sludge flocs. However, until now, the EPS are rather classified by the method used for extraction than by a theoretical consideration of their function and composition. In this paper, a new classification paradigm of EPS was proposed, which offered a novel approach to identify the role of EPS in the formation of activated sludge flocs. The current study gave an exploration to distinguish the EPS in the floc level (extra-microcolony polymers, EMPS) and in the microcolony level (extra-cellular polymers, ECPS). It was found that cation exchange resin treatment is efficient to disintegrate the flocs for EMPS extraction, however, inefficient to disaggregate the microcolonies for ECPS harvesting. A two-steps extraction strategy (cation exchange resin treatment followed by ultrasonication-high speed centrifugation treatment) was suggested to separate these two types of EPS in activated sludge flocs and the physicochemical characteristics of EMPS and ECPS were compared. The protein/polysaccharide ratio of ECPS was higher than that of EMPS and the molecular weight of proteins in EMPS and ECPS were found to be different. The ECPS contained higher molecular weight proteins and more hydrophobic substances than the EMPS contained. The result of excitation-emission matrix fluorescence spectroscopy analysis also showed that the EMPS and the ECPS have different fluorescent expressions and the components of EMPS were more diverse than that of ECPS. All results reported herein demonstrated that two different types of exopolymers exist in the activated sludge flocs and the inter-particle forces for aggregation of activated sludge flocs are not identical between the floc level and the microcolony level. It suggested that cation bridging interactions are more crucial in floc level flocculation, while the entanglement and hydrophobic interactions are more important in microcolony level cohesion

  19. Characterization and degradation studies on synthetic polymers for aerospace application

    Science.gov (United States)

    Hsu, M. T. S.

    1982-01-01

    The anti-misting additive for jet fuels known as FM-9 (proprietary polymer) was characterized by elemental analysis, solubility studies and molecular weight determination. Physical properties of surface tension, viscosity, specific gravity and other physical parameters were determined. These results are compared with properties of polyisobutylene and fuels modified with the same; the misting characteristics of polyisobutylene and FM-9 in Jet A fuel are included. Characterization and degradation of phthalocyanine and its derivatives were accomplished by use of a mass spectrometer and a pyroprobe solid pyrolyzer. Metal phthalocyanine tetracarboxylic acids and phthalocyanine-tetraamine cured epoxies were studied. Epoxy/graphite composite panels were exposed to a NASA-Ames radiant panel fire simulator in the flaming and non-flaming modes; toxic gases of HCN and HZS were measured along with oxygen, Co2, Co, and organic gases.

  20. The Preparation and Characterization of INTEC Phase 2b Composition Variation Study Glasses

    Energy Technology Data Exchange (ETDEWEB)

    B. A. Staples; B. A. Scholes; L. L. Torres; C. A. Musick; B. R. Boyle (INEEL); D. K. Peeler (SRTC); J. D. Vienna (PNNL)

    2000-02-01

    The second phase of the composition variation study (CVS) for the development of glass compositions to immobilize Idaho Nuclear Technology and Engineering Center (INTEC) high level wastes (HLW) is complete. This phase of the CVS addressed waste composition of high activity waste fractions (HAW) from the initial separations flowsheet. Updated estimates if INTEC calcined HLW compositions and of high activity waste fractions proposed to be separated from dissolved calcine were used as the waste component for this CVS phase. These wastes are of particular interest because high aluminum, calcium, zirconium, fluorine, potassium, and low iron and sodium content places them outside the vitrification experience in the Department of Energy complex. Because of the presence of calcium and fluorine, two major zirconia calcine components not addressed in Phase I, a series of scooping tests, designated Phase 2a, were performed. The results of these tests provided information on the effects of calcium and fluoride solubility and their impacts on product properties and composition boundary information for Phase 2b. Details and results of Phase 2a are reported separately. Through application of statistical techniques and the results of Phase 2a, a test matrix was defined for Phase 2b of the CVS. From this matrix, formulations were systematically selected for preparation and characterization with respect to visual and optical homogeneity, viscosity as a function of melt temperature, liquidus temperature (TL), and leaching properties based on response to the product consistency test. The results of preparing and characterizing the Phase 2b glasses are presented in this document. Based on the results, several formulations investigated have suitable properties for further development. A full analysis of the composition-product characteristic relationship of glasses being developed for immobilizing INTEC wastes will be performed at the completion of composition-property relationship

  1. Study of factors involved in the gravimetric separation process to treat soil contaminated by municipal solid waste.

    Science.gov (United States)

    Mouedhen, Ikbel; Coudert, Lucie; Blais, Jean-François; Mercier, Guy

    2018-03-01

    The current research investigated the effectiveness of a gravimetric process (shaking table) to treat soil contaminated by municipal solid waste. A detailed characterization of the inorganic pollutants was performed, followed by concentrating the metals within smaller volumes using the shaking table technology. The densimetric examination of the 1-2 mm and 0.250-1 mm fractions of the contaminated soil showed that lead (Pb), copper (Cu), and tin (Sn) were mostly concentrated in the heavy fraction (metal removals > 50%). Scanning electron microscopy coupled with elemental analysis indicated the relevance of using gravimetric processes to treat this soil sample. The influence of shaking table parameters was determined using a Box-Behnken design. The tilt and washing water flow demonstrated significant effects on the motion of the 1-2 mm soil fraction and on the removal of Pb, Cu, and Sn. The results obtained under the optimal settings of the shaking table defined using the Box-Behnken methodology when treating the 1-2 mm fraction were close to those obtained when using dense media separation. The recovered mass of the concentrate was approximately 20.8% (w.w -1 ) of the total mass. The removals of Pb, Cu, and Sn were estimated to be 67.3%, 54.5% and 54.6% respectively. The predicted and experimental mass distributions of the medium (1-2 mm) and fine-sized (0.250-1 mm) particles were compared successively under some selected conditions. The mass distribution of both fractions showed similar tendencies in response to the forces applied by each condition. However, lowering the forces induced by the bumping action and the flowing film was recommended so as to efficiently treat the fine fraction (0.250-1 mm). The recovered mass of the concentrate (10%) was slightly lower than that obtained by dense media separation (13%). However, satisfactory removal yields were obtained for Pb, Cu, and Sn (42.7%, 23.6%, and 35% respectively). Copyright © 2017 Elsevier Ltd. All

  2. Nuclear characterization of radioactive bioglass seed for brachytherapy studies

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, L.B.; Campos, T.P.R., E-mail: Lucibn19@yahoo.com.br, E-mail: Campos@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2011-07-01

    This paper aims to analyze the isotopic compositions of the radioactive bioglass seeds for brachytherapy studies. Bioglass seeds were synthesized by sol-gel process, distributed in the seed samples, such as [Si: Ca: Ho], [Si: Ca: Ho: Zr], [Si: Ca: Ho: Ba], [Si: Ca: Sm] and [Si: Ca: Sm: Ba]. The bioglass seeds were irradiated at the TRIGA nuclear reactor - CDTN for a period of eight hours on a turntable around the reactor core for nuclear characterization studies. Nuclear characterization of the radioactive bioglass seeds by gamma spectrometry provided the gamma signatures of Sm-153 and Ho-166 followed by the Ba and Zr contrast agents. The gamma and X-ray spectra were plotted for analysis of the isotopic compositions of bioglass seeds. Gamma spectrum from the Ho-166 radioisotope and the X-ray spectrum of the Ba and Zr elements for [Si: Ca: Ho: Ba] and [Si: Ca: Ho: Zr] were showed. The particle ranges on ceramic; water and tissue were also analyzed using gamma and beta particle evaluations. The beta particle is absorbed around the seed, whereas the gamma particle can travel far from the seed position. Therefore, for small volume and consequentially small mass, the absorbed dose of beta particles close to the seed is very high. These results complement the study of the characterization and monitoring of bioglass seeds for brachytherapy implants. (author)

  3. LCA of the Collection, Transportation, Treatment and Disposal of Source Separated Municipal Waste: A Southern Italy Case Study

    Directory of Open Access Journals (Sweden)

    Giovanni De Feo

    2016-10-01

    Full Text Available This study performed a Life Cycle Assessment of the collection, transport, treatment and disposal of source-separated municipal waste (MW in Baronissi, a town of 17,000 inhabitants in the Campania region of Italy. Baronissi is a high-performing town in a region with scarcity of MW facilities. The environmental impacts were assessed with three different methods—IPCC 2007, Ecological Footprint and ReCiPe 2008—in order to evaluate how they influence the results as well as how the global warming affects the results, since it is one of the major environmental concerns of people. The obtained results showed how the presence of facilities in the area is fundamental. Their lack means high environmental loads due to the transportation of materials for long distances, particularly for the organic fraction. The presence of a composting plant at 10 km from the municipality would result in a decrease of 65% of the impacts due to the external transport, regardless of the evaluation method. The results obtained with ReCiPe 2008 and Ecological Footprint agreed, while those obtained with IPCC 2007 were very different since global warming is strongly affected by the transport phase. IPCC 2007 does not allow to take into account the advantages obtainable with a good level of separate collection. Considering a single impact evaluation method, there is a high risk of coming to misleading conclusions.

  4. Size-separated particle fractions of stainless steel welding fume particles - A multi-analytical characterization focusing on surface oxide speciation and release of hexavalent chromium.

    Science.gov (United States)

    Mei, N; Belleville, L; Cha, Y; Olofsson, U; Odnevall Wallinder, I; Persson, K-A; Hedberg, Y S

    2018-01-15

    Welding fume of stainless steels is potentially health hazardous. The aim of this study was to investigate the manganese (Mn) and chromium (Cr) speciation of welding fume particles and their extent of metal release relevant for an inhalation scenario, as a function of particle size, welding method (manual metal arc welding, metal arc welding using an active shielding gas), different electrodes (solid wires and flux-cored wires) and shielding gases, and base alloy (austenitic AISI 304L and duplex stainless steel LDX2101). Metal release investigations were performed in phosphate buffered saline (PBS), pH 7.3, 37°, 24h. The particles were characterized by means of microscopic, spectroscopic, and electroanalytical methods. Cr was predominantly released from particles of the welding fume when exposed in PBS [3-96% of the total amount of Cr, of which up to 70% as Cr(VI)], followed by Mn, nickel, and iron. Duplex stainless steel welded with a flux-cored wire generated a welding fume that released most Cr(VI). Nano-sized particles released a significantly higher amount of nickel compared with micron-sized particle fractions. The welding fume did not contain any solitary known chromate compounds, but multi-elemental highly oxidized oxide(s) (iron, Cr, and Mn, possibly bismuth and silicon). Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Generation and collection of restaurant waste: Characterization and evaluation at a case study in Italy.

    Science.gov (United States)

    Tatàno, Fabio; Caramiello, Cristina; Paolini, Tonino; Tripolone, Luca

    2017-03-01

    Because restaurants (as a division of the hospitality sector) contribute to the generation of commercial and institutional waste, thus representing both a challenge and an opportunity, the objective of the present study was to deepen the knowledge of restaurant waste in terms of the qualitative and quantitative characteristics of waste generation and the performance achievable by the implementation of a separate collection scheme. In this study, the generated waste was characterized and the implemented separate collection was evaluated at a relevant case study restaurant in a coastal tourist area of Central Italy (Marche Region, Adriatic Sea side). The qualitative (compositional) characterization of the generated total restaurant waste showed considerable incidences of, in decreasing order, food (28.2%), glass (22.6%), paper/cardboard (19.1%), and plastic (17.1%). The quantitative (parametric) characterization of the generated restaurant waste determined the unit generation values of total waste and individual fractions based on the traditional employee and area parameters and the peculiar meal parameter. In particular, the obtained representative values per meal were: 0.72kgmeal -1 for total waste, and ranging, for individual fractions, from 0.20 (for food) to 0.008kgmeal -1 (for textile). Based on the critical evaluation of some of the resulting unit waste generation values, possible influences of restaurant practices, conditions, or characteristics were pointed out. In particular, food waste generation per meal can likely be limited by: promoting and using local, fresh, and quality food; standardizing and limiting daily menu items; basing food recipes on consolidated cooking knowledge and experience; and limiting plate sizes. The evaluation of the monthly variation of the monitored separate collection, ranging from an higher level of 52.7% to a lower level of 41.4%, indicated the following: a reduction in the separate collection level can be expected at times of

  6. Preliminary Hydrogeologic Characterization Results from the Wallula Basalt Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    B.P. McGrail; E. C. Sullivan; F. A. Spane; D. H. Bacon; G. Hund; P. D. Thorne; C. J. Thompson; S. P. Reidel; F. S. Colwell

    2009-12-01

    The DOE's Big Sky Regional Carbon Sequestration Partnership has completed drilling the first continental flood basalt sequestration pilot borehole to a total depth (TD) of 4,110 feet on the Boise White Paper Mill property at Wallula, Washington. Site suitability was assessed prior to drilling by the 2007-2008 acquisition, processing and analysis of a four-mile, five-line three component seismic swath, which was processed as a single data-dense line. Analysis of the seismic survey data indicated a composite basalt formation thickness of {approx}8,000 feet and absence of major geologic structures (i.e., faults) along the line imaged by the seismic swath. Drilling of Wallula pilot borehole was initiated on January 13, 2009 and reached TD on April 6, 2009. Based on characterization results obtained during drilling, three basalt breccia zones were identified between the depth interval of 2,716 and 2,910 feet, as being suitable injection reservoir for a subsequent CO2 injection pilot study. The targeted injection reservoir lies stratigraphically below the massive Umtanum Member of the Grande Ronde Basalt, whose flow-interior section possesses regionally recognized low-permeability characteristics. The identified composite injection zone reservoir provides a unique and attractive opportunity to scientifically study the reservoir behavior of three inter-connected reservoir intervals below primary and secondary caprock confining zones. Drill cuttings, wireline geophysical logs, and 31one-inch diameter rotary sidewall cores provided geologic data for characterization of rock properties. XRF analyses of selected rock samples provided geochemical characterizations of the rocks and stratigraphic control for the basalt flows encountered by the Wallula pilot borehole. Based on the geochemical results, the pilot borehole was terminated in the Wapshilla Ridge 1 flow of the Grande Ronde Basalt Formation. Detailed hydrologic test characterizations of 12 basalt interflow

  7. Hydrochloride salt co-crystals: preparation, characterization and physicochemical studies.

    Science.gov (United States)

    Parmar, Vijaykumar K; Shah, Shailesh A

    2013-01-01

    Co-crystallization approach for modification of physicochemical properties of hydrochloride salt is presented. The objective of this investigation was to study the effect of co-crystallization with different co-crystal formers on physicochemical properties of fluoxetine hydrochloride (FH). FH was screened for co-crystallization with a series of carboxylic acid co-formers by slow evaporation method. Photomicrographs and melting points of crystalline phases were determined. The co-crystals were characterized by FTIR, DSC and PXRD methods. Solubility of co-crystals was determined in water and buffer solutions. Powder and intrinsic dissolution profiles were assessed for co-crystals. Physical mixtures of drug and co-formers were used for comparisons at characterizations and physicochemical properties evaluation stages. Four co-crystals of FH viz. Fluoxetine hydrochloride-maleic acid (FH-MA), Fluoxetine hydrochloride-glutaric acid (FH-GA), Fluoxetine hydrochloride-L-tartaric acid (FH-LTA) and Fluoxetine hydrochloride-DL-tartaric acid (FH-DLTA) were obtained from screening experiments. Physical characterization showed that they have unique crystal morphology, thermal, spectroscopic and X-ray diffraction properties. Solubility and dissolution studies showed that Fluoxetine hydrochloride-maleic acid co-crystal possess high aqueous solubility in distilled water, pH 4.6, 7.0 buffer solutions and dissolution rate in distilled water than that of pure drug. Co-crystal formation approach can be used for ionic API to tailor its physical properties.

  8. Discrimination and chemical characterization of different Paeonia lactifloras (Radix Paeoniae Alba and Radix Paeoniae Rubra) by infrared macro-fingerprint analysis-through-separation

    Science.gov (United States)

    Wang, Yang; Wang, Ping; Xu, Changhua; Sun, Suqin; Zhou, Qun; Shi, Zhe; Li, Jin; Chen, Tao; Li, Zheng; Cui, Weili

    2015-11-01

    Paeonia lactiflora, a commonly used herbal medicine (HM) in Traditional Chinese Medicine (TCM), mainly has two species, Radix Paeoniae Alba (RPA) and Radix Paeoniae Rubra (RPR), for different clinical applications in TCM. For expounding the chemical profile of RPA and RPR and ensuring the clinical efficacy and safety, an infrared macro-fingerprint analysis-through-separation method integrated with statistical pattern recognition was developed to analyze and discriminate the two Paeonia lactifloras. In IR spectra, the major difference between the two was in the range of 1200-900 cm-1: the strongest peak of RPA was at 1024 cm-1, while that of RPR was 1049 cm-1. The difference was magnified in second derivative spectra. The findings were further verified by investigating the separation process of total glucosides, stepwisely monitored by both of IR and UPLC-MS/MS. Simultaneously, the aqueous extracts of RPA and RPR had been separated continuously to acquire the comprehensively hierarchical chemical characteristics for undoubtedly identification and subsequently discrimination of the two herbs. Moreover, 60 batches of the two HMs (30 for each) were objectively classified by principal component regression (PCR) model based on IR macro-fingerprints.

  9. Engineering Studies of a Pilot Plant for Laser Isotope Separation of CARBON-13 by Multiphoton Dissociation of Chlorodifluoromethane

    Science.gov (United States)

    Mehmetli, Bulent Ahmet

    Recent research in laser isotope separation by multiphoton dissociation (LISMPD) of ^{13 }C suggests that an LISMPD commercial process is more economical than the cryogenic CO distillation technology currently used to meet most of the world's ^ {13}C demand. In this dissertation, experimental studies of an engineering process for LISMPD of polyatomic molecules is examined. The experimental results have been obtained by MPD of chlorodifluoromethane (CF_2 HCl) to yield ^{13}C -enriched tetrafluoroethylene rm(C_2F _4). Emphasis is on research leading to the development of a practical chemical plant for the preparation of stable isotopes by this method. The experimental program has achieved the design, construction, and operation of a laboratory-scale ^{13}C separation apparatus and parametric dependences of enrichment factors and dissociated fractions. In this experiment, the reactant gas, industrial grade CF_2HCl, flows continuously along the axis of a stainless steel reaction cell. The beam of a commercial CO_2 TEA laser, delivering up to 3 J/pulse at a single wavelength, is focused into the cell to induce isotope-selective multiphoton dissociation. The ^{13}C-enriched reaction product, rm C_2F_4, is analyzed by mass spectroscopy for its isotopic content. Typical production rates of the setup are about 10 g/year ^{13}C at an enrichment of 15% or 1 g/year at an enrichment of 65%. The results of a detailed cost analysis, which takes into account different reaction conditions and laser types, showed that at production rates of 7,000 kg per year, the cost of ^{13}C can be as low as 4/g. This figure is about an order of magnitude less than the cost of ^13 C obtained by cryogenic distillation of CO. The design, construction, and operation of a CO _2 MOPA (Master Oscillator/ Power Amplifier) laser is proposed because a MOPA combines the advantages of favorable isotope separation reaction conditions of TEA lasers and the cheaper photons of cw discharges. Analytical

  10. Effect of bond-disorder on the phase-separation kinetics of binary mixtures: A Monte Carlo simulation study

    Science.gov (United States)

    Singh, Awaneesh; Singh, Amrita; Chakraborti, Anirban

    2017-09-01

    We present Monte Carlo (MC) simulation studies of phase separation in binary (AB) mixtures with bond-disorder that is introduced in two different ways: (i) at randomly selected lattice sites and (ii) at regularly selected sites. The Ising model with spin exchange (Kawasaki) dynamics represents the segregation kinetics in conserved binary mixtures. We find that the dynamical scaling changes significantly by varying the number of disordered sites in the case where bond-disorder is introduced at the randomly selected sites. On the other hand, when we introduce the bond-disorder in a regular fashion, the system follows the dynamical scaling for the modest number of disordered sites. For a higher number of disordered sites, the evolution morphology illustrates a lamellar pattern formation. Our MC results are consistent with the Lifshitz-Slyozov power-law growth in all the cases.

  11. Coupling Optimization Design and Experimental Study on Stable Isotope 13C Separation of the Double-stage Cascade

    Directory of Open Access Journals (Sweden)

    TIAN Ye-sheng;LI Hu-lin;JIANG Yong-yue;LONG Lei;JI Yong-zhe;ZHOU Jian-yue

    2016-08-01

    Full Text Available A coupling optimization design and experimental study method with uniform experimental and Aspen process simulation was established in this paper, which was used for stable isotope 13C separation of the double-stage cascade. Based on the above method, the optimization operating parameters were received. The coupling optimization simulation value showed good agreement with the experimental dates, and the average relative error was only 6.5%. On the other hand, compared with the initial test result, the 13C abundance of optimized experimental was 14.1%, and the actual growth rate of 13C abundance was more than 25%. More importantly, The optimization experimental did not increase energy consumption. The method confirmed by the experiment could provide a solid foundation for the cascade process of 13C industrialization, and it could also be applied to other traditional distillation industry.

  12. Marriage, Separation and Beyond: A Longitudinal Study of Families of Children with Intellectual and Developmental Disabilities in a Norwegian Context.

    Science.gov (United States)

    Tøssebro, Jan; Wendelborg, Christian

    2017-01-01

    This study addresses family structure in families raising a child with disabilities in Norway. The aims are to add to the literature on termination of parental relationships and to explore family research topics that are rarely discussed in disability research, such as cohabitation versus marriage and repartnering. Longitudinal survey data on families of children with intellectual and developmental disabilities who were born 1993-1995 were compared with register data on all families of same-aged children (five waves 1999-2012). Parents of children with disabilities had slightly lower termination rates and formalized their partnerships earlier. Furthermore, the rate of repartnering among divorced/separated mothers of young children with disabilities was similar to that of other mothers but decreases later in the child's life course. Results support the view that findings diverge and are most likely dependent on context. © 2015 The Authors. Journal of Applied Research in Intellectual Disabilities Published by John Wiley & Sons Ltd.

  13. Parental separation in childhood as a risk factor for depression in adulthood: a community-based study of adolescents screened for depression and followed up after 15 years.

    Science.gov (United States)

    Bohman, Hannes; Låftman, Sara Brolin; Päären, Aivar; Jonsson, Ulf

    2017-03-29

    Earlier research has investigated the association between parental separation and long-term health outcomes among offspring, but few studies have assessed the potentially moderating role of mental health status in adolescence. The aim of this study was to analyze whether parental separation in childhood predicts depression in adulthood and whether the pattern differs between individuals with and without earlier depression. A community-based sample of individuals with adolescent depression in 1991-93 and matched non-depressed peers were followed up using a structured diagnostic interview after 15 years. The participation rate was 65% (depressed n = 227; non-depressed controls n = 155). Information on parental separation and conditions in childhood and adolescence was collected at baseline. The outcome was depression between the ages 19-31 years; information on depression was collected at the follow-up diagnostic interview. The statistical method used was binary logistic regression. Our analyses showed that depressed adolescents with separated parents had an excess risk of recurrence of depression in adulthood, compared with depressed adolescents with non-separated parents. In addition, among adolescents with depression, parental separation was associated with an increased risk of a switch to bipolar disorder in adulthood. Among the matched non-depressed peers, no associations between parental separation and adult depression or bipolar disorder were found. Parental separation may have long-lasting health consequences for vulnerable individuals who suffer from mental illness already in adolescence.

  14. Early abdominal closure using component separation in patients with an open abdomen after trauma: a pilot study

    Directory of Open Access Journals (Sweden)

    Chopra K

    2015-02-01

    Full Text Available Karan Chopra,1 Kashyap Komarraju Tadisina,1 Jamil A Matthews,1 Jennifer Sabino,1 Devinder P Singh,1 Wassim Habre2 1University of Maryland Medical Center, Baltimore, MD, 2Crozer-Chester Medical Center, Upland, PA, USA Background: Permanent abdominal wall closure in patients undergoing damage-control laparotomy is achieved using techniques involving separation and advancement of abdominal wall components along with surgical mesh. However, these techniques are costly, morbid, and time-consuming. We compared outcomes following permanent abdominal closure using component separation (CS with non-cross-linked porcine acellular dermal matrix (PADM versus temporizing split-thickness skin graft (STSG closure. Materials and methods: A retrospective review identified eleven patients who underwent damage-control laparotomies from January 2010 to June 2011. Outcomes assessed included hospital length of stay (LOS, days on ventilator, size of defect and tissue matrix, and postoperative functionality. Results: Of the eleven patients identified, primary closure was achieved in five, CS/PADM closure in four, and STSG closure in two. Those with primary closure were excluded from the study. In the CS/PADM group, large defects (>24×20 cm were successfully closed using CS with PADM. Patients in the CS/PADM group had reduced third-space fluid loss, less difficulty in managing the open abdominal wound, and decreased risks for potential enterocutaneous fistulae, and intra-abdominal abscess formation. Total hospital LOS and days on the ventilator were also significantly reduced in the CS/PADM group compared with the STSG group. Conclusion: Early abdominal closure using CS/PADM was safe and effective in these patients, and may be cost-effective because only one operation is required. The shorter hospital LOS and days on the ventilator observed versus STSG closure appear promising, although further study is required. Keywords: acellular dermal matrix, laparotomy, abdominal

  15. Thermodynamic and kinetic study of chiral separations of coumarin-based anticoagulants on derivatized amylose stationary phase.

    Science.gov (United States)

    Gebreyohannes, Kahsay G; McGuffin, Victoria L

    2010-09-17

    Thermodynamic and kinetic studies are performed on amylose derivatized with tris-(3,5-dimethylphenyl carbamate) stationary phase for the chiral separation of coumarin-based anticoagulants. Polar-organic eluents that contain acetonitrile as bulk solvent with modifiers such as methanol, i-butanol, t-butanol, and tetrahydrofuran are used in the study. Temperature is varied from 5 to 45 degrees C at constant pressure of 1500psi. In general, both retention and enantioselectivity decrease as the temperature increases and as hydrogen bond donating ability of the modifiers increases. The van't Hoff plots are found to show both linear and non-linear behavior. The non-linear plots are believed to be the result of conformational changes in the derivatized amylose phase and are observed around room temperature. The retention behavior in acetonitrile mobile phase provides a linear enthalpy-entropy compensation plot, indicating that all coumarins may have a similar retention mechanism. In contrast, enthalpy-entropy compensation is not observed for warfarin and coumatetralyl enantiomers when separated with different organic modifiers in the mobile phase. The kinetic data indicate that the rate of sorption is always greater than the rate of desorption. An increase in the concentration of alcohol modifiers causes an increase in the desorption rate constant. In contrast, an increase in the concentration of tetrahydrofuran causes a decrease in the desorption rate constant. This effect is most significant for the second eluted enantiomer of coumatetralyl, for which the desorption rate is 36 times slower than the first eluted enantiomer. 2010 Elsevier B.V. All rights reserved.

  16. Electrostatic separation of mineral and vegetal powders with a custom built corona separator: application to biorefinery of rice husk

    Science.gov (United States)

    Rajaonarivony, Rova Karine; Rouau, Xavier; Dascalescu, Lucien; Mayer-Laigle, Claire

    2017-06-01

    In a dry biorefinery scheme, the separation of plant materials into powders rich in the constituents of interest is a crucial step. In recent years, electrostatic separation of agri-resources has sparked a growing interest for its potentialities, but optimization efforts remain to be done especially in case of fine powders. In this study a custom-designed corona-electrostatic separator has been built and its usage for the separation of mineral (ash from rice husk) and vegetal powders (cellulose fibers) with different particle size distributions has been studied. First, the powders have been characterized by their electric charge decay curves and their behaviour on the separator was studied. At a second time, separation tests have been carried out with blends of these two powders, and with native, finely ground, rice husk powder (constituted of both mineral and vegetal particles). In each case, the efficiency of the process was evaluated.

  17. Simultaneous dual-color fluorescence microscope: a characterization study.

    Science.gov (United States)

    Li, Zheng; Chen, Xiaodong; Ren, Liqiang; Song, Jie; Li, Yuhua; Zheng, Bin; Liu, Hong

    2013-01-01

    High spatial resolution and geometric accuracy is crucial for chromosomal analysis of clinical cytogenetic applications. High resolution and rapid simultaneous acquisition of multiple fluorescent wavelengths can be achieved by utilizing concurrent imaging with multiple detectors. However, such class of microscopic systems functions differently from traditional fluorescence microscopes. To develop a practical characterization framework to assess and optimize the performance of a high resolution and dual-color fluorescence microscope designed for clinical chromosomal analysis. A dual-band microscopic imaging system utilizes a dichroic mirror, two sets of specially selected optical filters, and two detectors to simultaneously acquire two fluorescent wavelengths. The system's geometric distortion, linearity, the modulation transfer function, and the dual detectors' alignment were characterized. Experiment results show that the geometric distortion at lens periphery is less than 1%. Both fluorescent channels show linear signal responses, but there exists discrepancy between the two due to the detectors' non-uniform response ratio to different wavelengths. In terms of the spatial resolution, the two contrast transfer function curves trend agreeably with the spatial frequency. The alignment measurement allows quantitatively assessing the cameras' alignment. A result image of adjusted alignment is demonstrated to show the reduced discrepancy by using the alignment measurement method. In this paper, we present a system characterization study and its methods for a specially designed imaging system for clinical cytogenetic applications. The presented characterization methods are not only unique to this dual-color imaging system but also applicable to evaluation and optimization of other similar multi-color microscopic image systems for improving their clinical utilities for future cytogenetic applications.

  18. Comparative study of cylindrical and parallel-plate electrophoretic separations for the removal of ions and sub-23 nm particles.

    Science.gov (United States)

    Yu, Tongzhu; Yang, Yixin; Liu, Jianguo; Gui, Huaqiao; Zhang, Jiaoshi; Cheng, Yin; Wang, Wenyu; Du, Peng; Wang, Jie; Wang, Huanqin

    2017-12-01

    Cylindrical and parallel-plate electrophoretic separations for the removal of ions and sub-23 nm particles were compared in this study. First, COMSOL Multiphysics® software was utilized to simulate the ion and particle trajectories inside both electrophoretic separations. The results show that ions and sub-23 nm particles are removed simultaneously and that all particles can pass through both electrophoretic separations smoothly at a trap voltage of 25 V. The experimental results show that ion losses become smaller with increasing ion flow rates, and ion losses of the cylindrical and parallel-plate electrophoretic separations range from 56.2 to 71.6% and from 43.8 to 59.6%, respectively, at ion flow rates ranging from 1-3 L/min. For the removal of ions and sub-23 nm particles, the collection efficiency of both electrophoretic separations can reach 100%, but the parallel-plate electrophoretic separation requires a lower trap voltage. The particle loss of the parallel-plate electrophoretic separation is under approximately 10%, which is lower than that of the cylindrical electrophoretic separation. In particular, for large particles (800-2500 nm), the particle losses inside the cylindrical electrophoretic separation are approximately two times higher than those inside the parallel-plate electrophoretic separation. The parallel-plate electrophoretic separation is beneficial for the removal of ions and sub-23 nm particles. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. A detached eddy simulation model for the study of lateral separation zones along a large canyon-bound river

    Science.gov (United States)

    Alvarez, Laura V.; Schmeeckle, Mark W.; Grams, Paul E.

    2017-01-01

    Lateral flow separation occurs in rivers where banks exhibit strong curvature. In canyon-boundrivers, lateral recirculation zones are the principal storage of fine-sediment deposits. A parallelized,three-dimensional, turbulence-resolving model was developed to study the flow structures along lateralseparation zones located in two pools along the Colorado River in Marble Canyon. The model employs thedetached eddy simulation (DES) technique, which resolves turbulence structures larger than the grid spacingin the interior of the flow. The DES-3D model is validated using Acoustic Doppler Current Profiler flowmeasurements taken during the 2008 controlled flood release from Glen Canyon Dam. A point-to-pointvalidation using a number of skill metrics, often employed in hydrological research, is proposed here forfluvial modeling. The validation results show predictive capabilities of the DES model. The model reproducesthe pattern and magnitude of the velocity in the lateral recirculation zone, including the size and position ofthe primary and secondary eddy cells, and return current. The lateral recirculation zone is open, havingcontinuous import of fluid upstream of the point of reattachment and export by the recirculation returncurrent downstream of the point of separation. Differences in magnitude and direction of near-bed andnear-surface velocity vectors are found, resulting in an inward vertical spiral. Interaction between therecirculation return current and the main flow is dynamic, with large temporal changes in flow direction andmagnitude. Turbulence structures with a predominately vertical axis of vorticity are observed in the shearlayer becoming three-dimensional without preferred orientation downstream.

  20. Separating generalized anxiety disorder from major depression using clinical, hormonal, and structural MRI data: A multimodal machine learning study.

    Science.gov (United States)

    Hilbert, Kevin; Lueken, Ulrike; Muehlhan, Markus; Beesdo-Baum, Katja

    2017-03-01

    Generalized anxiety disorder (GAD) is difficult to recognize and hard to separate from major depression (MD) in clinical settings. Biomarkers might support diagnostic decisions. This study used machine learning on multimodal biobehavioral data from a sample of GAD, MD and healthy subjects to differentiate subjects with a disorder from healthy subjects (case-classification) and to differentiate GAD from MD (disorder-classification). Subjects with GAD (n = 19), MD without GAD (n = 14), and healthy comparison subjects (n = 24) were included. The sample was matched regarding age, sex, handedness and education and free of psychopharmacological medication. Binary support vector machines were used within a nested leave-one-out cross-validation framework. Clinical questionnaires, cortisol release, gray matter (GM), and white matter (WM) volumes were used as input data separately and in combination. Questionnaire data were well-suited for case-classification but not disorder-classification (accuracies: 96.40%, p  .22). The opposite pattern was found for imaging data (case-classification GM/WM: 58.71%, p = .09/43.18%, p > .66; disorder-classification GM/WM: 68.05%, p = .034/58.27%, p > .15) and for cortisol data (38.02%, p = .84; 74.60%, p = .009). All data combined achieved 90.10% accuracy (p disorder-classification. In line with previous evidence, classification of GAD was difficult using clinical questionnaire data alone. Particularly cortisol and GM volume data were able to provide incremental value for the classification of GAD. Findings suggest that neurobiological biomarkers are a useful target for further research to delineate their potential contribution to diagnostic processes.

  1. Characterization of Polyester Cloth as an Alternative Separator to Nafion Membrane in Microbial Fuel Cells for Bioelectricity Generation Using Swine Wastewater.

    Science.gov (United States)

    Kim, Taeyoung; Kang, Sukwon; Sung, Je Hoon; Kang, Youn Koo; Kim, Young Hwa; Jang, Jae Kyung

    2016-12-28

    Polyester cloth (PC) was selected as a prospective inexpensive substitute separator material for microbial fuel cells (MFCs). PC was compared with a traditional Nafion proton exchange membrane (PEM) as an MFC separator by analyzing its physical and electrochemical properties. A single layer of PC showed higher mass transfer (e.g., for O₂/H⁺/ions) than the Nafion PEM; in the case of oxygen mass transfer coefficient (ko), a rate of 50.0 × 10⁻⁵ cm·s⁻¹ was observed compared with a rate of 20.8 × 10⁻⁵ cm/s in the Nafion PEM. Increased numbers of PC layers were found to reduce the oxygen mass transfer coefficient. In addition, the diffusion coefficient of oxygen (DO) for PC (2.0-3.3 × 10⁻⁶ cm²/s) was lower than that of the Nafion PEM (3.8 × 10⁻⁶ cm²/s). The PC was found to have a low ohmic resistance (0.29-0.38 Ω) in the MFC, which was similar to that of Nafion PEM (0.31 Ω); this resulted in comparable maximum power density and maximum current density in MFCs with PC and those with Nafion PEMs. Moreover, a higher average current generation was observed in MFCs with PC (104.3 ± 15.3 A/m³) compared with MFCs with Nafion PEM (100.4 ± 17.7 A/m³), as well as showing insignificant degradation of the PC surface, during 177 days of use in swine wastewater. These results suggest that PC separators could serve as a low-cost alternative to Nafion PEMs for construction of cost-effective MFCs.

  2. LC-MS of Metmyoglobin at pH = 2: Separation and Characterization of Apomyoglobin and Heme by ESI-MS and UV-Vis

    Science.gov (United States)

    Stynes, Helen Cleary; Layo, Araceli; Smith, Richard W.

    2004-01-01

    The protein species of apomyoglobin (apoMb) and heme are freed and segregated from the aqueous protein solution of metmyoglobin by liquid chromatography, and are distinguished by UV-Vis absorption or electrospray ionization mass spectrometry (ESI-MS). This is an ingenious and effective approach to characterize apomyoglobin and heme, while students…

  3. Synthesis and Characterization of Organotin Containing Copolymers: Reactivity Ratio Studies

    Directory of Open Access Journals (Sweden)

    Mohamed H. El-Newehy

    2010-03-01

    Full Text Available Organotin monomers containing dibutyltin groups – dibutyltin citraconate (DBTC as a new monomer and dibutyltin maleate (DBTM – were synthesized. Free radical copolymerizations of the organotin monomers with styrene (ST and butyl acrylate (BA were performed. The overall conversion was kept low (≤15% wt/wt for all studied samples and the copolymers composition was determined from tin analysis using the Gillman and Rosenberg method. The reactivity ratios were calculated from the copolymer composition using the Fineman-Ross (FR method. The synthesized monomers were characterized by elemental analysis, 1H-, 13C-NMR and FTIR spectroscopy.

  4. Study of Periodic Forcing with a Dielectric Barrier Discharge Device for the Control of Flow Separation on a NACA 0012

    Science.gov (United States)

    Dygert, Joseph P.

    The continued high global demand for passenger and freight air traffic as well as increased use of unmanned aerial vehicles (UAVs), in spite of rising fuel costs and several tragic cases involving loss-of-control events, has resulted in researchers examining alternative technologies, which would result in safer, more reliable, and superior performing aircraft. Aerodynamic flow control may be the most promising approach to this problem having already proven its ability to enable higher flow efficiency while also simultaneously improving overall flow control. Recent research in the area of aerodynamic control is transitioning from traditional mechanical flow control devices such as slats and flaps to plasma actuators. Plasma actuators offer an inexpensive and energy efficient method of flow control. In addition, plasma actuator technology has the potential of application to a host of other aircraft performance parameters including applications in radar mitigation and in situ wing deicing. Dielectric Barrier Discharge (DBD), one of the most widely studied forms of plasma actuation, employs an electrohydrodynamic (EHD) device, which uses dominant electric fields and the respective electrically related body forces for actuation. Unlike momentum jets or other traditional flow control methods used on wings and tail surfaces, a DBD device operates without moving components or injecting any mass into the flow stream. Work performed focuses on qualitatively investigating experimentally the use of DBD devices for flow separation control on a NACA 0012-based 2D wing model. Flow visualization techniques illuminated flow seed particles around the model to determine the state of the flow (i.e., attached or separated) for various actuator cases. The DBD was operated in a steady-on mode as well as for three different pulsing frequencies (only for low power testing) based on the Strouhal frequency for each flight condition and compared to the clean (i.e., plasma off) case. Some of

  5. Determine separations process strategy decision

    Energy Technology Data Exchange (ETDEWEB)

    Slaathaug, E.J.

    1996-01-01

    This study provides a summary level comparative analysis of selected, top-level, waste treatment strategies. These strategies include No Separations, Separations (high-level/low-level separations), and Deferred Separations of the tank waste. These three strategies encompass the full range of viable processing alternatives based upon full retrieval of the tank wastes. The assumption of full retrieval of the tank wastes is a predecessor decision and will not be revisited in this study.

  6. Preparation and characterization of underwater superoleophobic chitosan/poly(vinyl alcohol) coatings for self-cleaning and oil/water separation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qian; Fu, Youjia; Yan, Xiaoxia; Chang, Yanjiao; Ren, Lili; Zhou, Jiang

    2017-08-01

    Highlights: • Underwater superoleophobic CS/PVA coatings were prepared using a facile method. • Immersion in NaOH solution was crucial to enhance roughness of the coating surface. • Effects of coating composition on wettability of coating surface were investigated. • The CS/PVA coatings possess self-cleaning property. • The CS/PVA coatings can be used for oil/water separation with high efficiency. - Abstract: In this paper, chitosan (CS)/poly(vinyl alcohol) (PVA) coatings cross-linked with glutaraldehyde (GA) were prepared. Effects of the coating composition and NaOH solution treatment on surface morphology and topography were investigated by scanning electron microscope and atomic force microscope. It was found that the process of immersing the CS/PVA coatings into NaOH solution was crucial to enhance rough structure on the coating surface. The rough surface structure and the hydrophilic groups of CS and PVA made the CS/PVA coatings possess underwater superoleophobicity and low adhesion to oil. Oil contact angle of the prepared CS/PVA coatings was up to 161° and slide angle was only 3°. Moreover, the CS/PVA coatings showed stable superoleophobicity in high salt, strong acidic, and alkaline environments as well as underwater self-cleaning property and excellent transparency. The CS/PVA coatings could be used for gravity driven oil/water separation with high efficiency.

  7. Characterization and Study of Transgenic Cultivars by Capillary and Microchip Electrophoresis

    Directory of Open Access Journals (Sweden)

    Elena Domínguez Vega

    2014-12-01

    Full Text Available Advances in biotechnology have increased the demand for suitable analytical techniques for the analysis of genetically modified organisms. Study of the substantial equivalence, discrimination between transgenic and non-transgenic cultivars, study of the unintended effects caused by a genetic modification or their response to diverse situations or stress conditions (e.g., environmental, climatic, infections are some of the concerns that need to be addressed. Capillary electrophoresis (CE is emerging as an alternative to conventional techniques for the study and characterization of genetically modified organisms. This article reviews the most recent applications of CE for the analysis and characterization of transgenic cultivars in the last five years. Different strategies have been described depending on the level analyzed (DNA, proteins or metabolites. Capillary gel electrophoresis (CGE has shown to be particularly useful for the analysis of DNA fragments amplified by PCR. Metabolites and proteins have been mainly separated using capillary zone electrophoresis (CZE using UV and MS detection. Electrophoretic chips have also proven their ability in the analysis of transgenic cultivars and a section describing the new applications is also included.

  8. Separation and characterization of sucrose esters from Oriental tobacco leaves using accelerated solvent extraction followed by SPE coupled to HPLC with ion-trap MS detection.

    Science.gov (United States)

    Zhu, Hongying; Feng, Yonggang; Yang, Jun; Pan, Wenjie; Li, Zhanghai; Tu, Yonggao; Zhu, Xiaolan; Huang, Guangming

    2013-08-01

    Sucrose esters (SEs) were successfully extracted from Oriental tobacco leaves using a new methodology based on accelerated solvent extraction followed by hydrophilic-lipophilic balanced cartridge cleanup step. The SEs were detected by HPLC with ion-trap MS detection using an electrospray interface operated in the positive ion mode. This methodology combines the high efficiency of extraction provided by a pressurized fluid and the highly sensitive characterization offered by ion-trap MS. Under the optimized conditions, 14 SEs were first identified among a total of 23 SEs found in Oriental tobacco leaves. Under the same conditions, only four new SEs were extracted by using traditional ultrasound-assisted extraction and liquid-solid extraction methods. The present method might be potentially useful in high-efficiency extraction and sensitive characterization of SEs from complex matrices such as tobacco leaves. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Modified diglycol-amides for actinide separation: solvent extraction and time-resolved laser fluorescence spectroscopy complexation studies

    Energy Technology Data Exchange (ETDEWEB)

    Wilden, A.; Modolo, G.; Lange, S.; Sadowski, F.; Bosbach, D. [Foschungszentrum Juelich GmbH, IEK-6, Juelich (Germany); Beele, B.B.; Panak, P.J. [Ruprecht-Karls-Universitaet Heidelberg, Physikalisch Chemisces Institut - PCI, Heidelberg (Germany); Karlsruher Institut fuer Technologie - INE, Karlsruhe (Germany); Skerencak-Frech, A.; Geist, A. [Karlsruher Institut fuer Technologie - INE, Karlsruhe (Germany); Iqbal, M. [University of Twente, Laboratory of Molecular Nanofabrication, Enschede (Netherlands); Department of Chemistry, University of Sargodha, Sargodha 40100 (Pakistan); Verboom, W. [University of Twente, Laboratory of Molecular Nanofabrication, Enschede (Netherlands)

    2013-07-01

    In this work, the back-bone of the diglycolamide-structure of the TODGA extractant was modified by adding one or two methyl groups to the central methylene carbon-atoms. The influence of these structural modifications on the extraction behavior of trivalent actinides and lanthanides and other fission products was studied in solvent extraction experiments. The addition of methyl groups to the central methylene carbon atoms leads to reduced distribution ratios, also for Sr(II). This reduced extraction efficiency for Sr(II) is beneficial for process applications, as the co-extraction of Sr(II) can be avoided, resulting in an easier process design. The use of these modified diglycol-amides in solvent extraction processes is discussed. Furthermore, the complexation of Cm(III) and Eu(III) to the ligands was studied using Time-Resolved-Laser-Fluorescence-Spectroscopy (TRLFS). The complexes were characterized by slope analysis and conditional stability constants were determined.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Experimental study on the separation of CO{sub 2} from flue gas using hollow fiber membrane contactors without wetting

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Shui-ping; Fang, Meng-Xiang; Zhang, Wei-Feng; Luo, Zhong-Yang; Cen, Ke-Fa [State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027 (China); Wang, Shu-Yuan; Xu, Zhi-Kang [Institute of Polymer Science, Zhejiang University, Hangzhou 310027 (China)

    2007-05-15

    Experiments on CO{sub 2} removal from flue gas using polypropylene (PP) hollow fiber membrane contactors were conducted in this study. Absorbents including aqueous potassium glycinate (PG) solution, aqueous solutions of monoethanolamine (MEA) and methyldiethanolamine (MDEA) were used to absorb CO{sub 2} in the experiments. Based on the wetting experimental results, aqueous PG solution can offer a higher surface tension than water, aqueous MEA and MDEA solutions. Aqueous PG solution has a lower potential of membrane wetting after a continuously steady operation for 40 h to maintain CO{sub 2} removal efficiency of about 90%. Under moderate operating conditions, effects of the temperature, flow rate, and concentration of absorbents, and the flow rate of flue gas as well as the volumetric concentration of carbon dioxide in the flue gas on the mass transfer rate of CO{sub 2} were studied on a pilot-scale test facility. Unlike conventional absorbents, the mass transfer decreases with an increasing liquid temperature when using aqueous PG solution. Results show that CO{sub 2} removal efficiency was above 90% and the mass transfer rate was above 2.0 mol/(m{sup 2} h) using the PG aqueous solution. It indicates that the hollow fiber membrane contactor has a great potential in the area of CO{sub 2} separation from flue gas when absorbent's concentration and liquid-gas pressure difference are designed elaborately. (author)

  12. An empirical method that separates irreversible stem radial growth from bark water content changes in trees: theory and case studies.

    Science.gov (United States)

    Mencuccini, Maurizio; Salmon, Yann; Mitchell, Patrick; Hölttä, Teemu; Choat, Brendan; Meir, Patrick; O'Grady, Anthony; Tissue, David; Zweifel, Roman; Sevanto, Sanna; Pfautsch, Sebastian

    2017-02-01

    Substantial uncertainty surrounds our knowledge of tree stem growth, with some of the most basic questions, such as when stem radial growth occurs through the daily cycle, still unanswered. We employed high-resolution point dendrometers, sap flow sensors, and developed theory and statistical approaches, to devise a novel method separating irreversible radial growth from elastic tension-driven and elastic osmotically driven changes in bark water content. We tested this method using data from five case study species. Experimental manipulations, namely a field irrigation experiment on Scots pine and a stem girdling experiment on red forest gum trees, were used to validate the theory. Time courses of stem radial growth following irrigation and stem girdling were consistent with a-priori predictions. Patterns of stem radial growth varied across case studies, with growth occurring during the day and/or night, consistent with the available literature. Importantly, our approach provides a valuable alternative to existing methods, as it can be approximated by a simple empirical interpolation routine that derives irreversible radial growth using standard regression techniques. Our novel method provides an improved understanding of the relative source-sink carbon dynamics of tree stems at a sub-daily time scale. © 2016 The Authors Plant, Cell & Environment Published by John Wiley & Sons Ltd.

  13. A study of separation and solidification of group II nuclides in waste salt delivered from the pyrochemical process of used nuclear fuel

    Science.gov (United States)

    Eun, H. C.; Choi, J. H.; Kim, N. Y.; Lee, T. K.; Han, S. Y.; Jang, S. A.; Kim, T. J.; Park, H. S.; Ahn, D. H.

    2017-08-01

    If group II nuclides, which contain high heat-generative elements, in waste salt are fabricated into a waste form rich in group II nuclides, the waste form can be used in radionuclide thermoelectric generator applications. For this reason, the separation of group II nuclides in salt (LiCl, LiCl-KCl) was conducted, after which a waste form rich in them was fabricated. In this study, group II nuclide chlorides in salt were effectively separated into a carbonate or oxychloride form, and the separated nuclides were successfully fabricated into a homogenous and stable glass waste form with high contents (45-50 wt%) of these nuclides.

  14. Synthesis, Characterization and Photophysical Studies of Tricoumarin-Pyridines.

    Science.gov (United States)

    Naik, Nirmala S; Shastri, Lokesh A; Bathula, Chinna; Chougala, Bahubali; Shastri, Samundeeswari; Holiyachi, Megharaja; Sunagar, Vinay

    2017-03-01

    A series of novel tricoumarin-pyridines have been synthesized by the reaction of 4-formyl coumarins and substituted 3-acetylcoumarin with ammonium acetate for the application in organic electronics as well as fluorescent dyes. The structures of all new compounds were confirmed and characterized by IR, (1)H NMR and ESI-Mass analysis. All the important photo physical prerequisites for organic electronic application such as strong and broad optical absorption, thermal stability were determined for the synthesized molecules. Optical properties were studied by UV-Vis absorption and fluorescence spectroscopy. Optical band gaps of the tricoumarin-pyridines were found to be 2.72-3.10 eV as calculated from their onset absorption edge. The tricoumarin-pyridines were thermally stable up to 290-370 °C as determined by thermogravimetric analysis (TGA). Photophysical studies indicate the synthesized materials are promising candidates for organic electronic applications.

  15. Synthesis, characterization and DNA interaction studies of new triptycene derivatives

    Directory of Open Access Journals (Sweden)

    Sourav Chakraborty

    2014-06-01

    Full Text Available A facile and efficient synthesis of a new series of triptycene-based tripods is being reported. Using 2,6,14- or 2,7,14-triaminotriptycenes as synthons, the corresponding triazidotriptycenes were prepared in high yield. Additionally, we report the transformation of 2,6,14- or 2,7,14-triaminotriptycenes to the corresponding ethynyl-substituted triptycenes via their tribromo derivatives. Subsequently, derivatization of ethynyl-substituted triptycenes was studied to yield the respective propiolic acid and ethynylphosphine derivatives. Characterization of the newly functionalized triptycene derivatives and their regioisomers were carried out using FTIR and multinuclear NMR spectroscopy, mass spectrometry, and elemental analyses techniques. The study of the interaction of these trisubstituted triptycenes with various forms of DNA revealed interesting dependency on the functional groups of the triptycene core to initiate damage or conformational changes in DNA.

  16. Characterization of Bismuth Germanate Detectors for Reaction Studies

    Science.gov (United States)

    Carls, A.; Kozub, R. L.; Chipps, K. A.; Pain, S. D.; Hertz-Kintish, D.; Thompson, P.; Waddell, D.

    2015-10-01

    Nuclear reactions utilizing radioactive ion beams emit particles and electromagnetic radiation that can provide useful information about reaction mechanisms, nuclear structure, and nuclear astrophysics. Owing to their high density and high Z, Bismuth Germanate (BGO) detectors are used in γ-ray decay studies where high efficiency is required. An array of such detectors will be used for future γ-ray studies with the new gas jet target JENSA (Jet Experiments in Nuclear Structure and Astrophysics), and the properties of each detector must be well known to better understand the data collected with them. Using the γ-ray sources 137Cs and 60Co along with background radiation, several BGO detectors were characterized by measuring their resolutions and efficiencies as functions of distance between source and detector. A detailed description of the procedure and results will be presented. This work is supported in part by the U.S. Department of Energy and the National Science Foundation.

  17. Operation of a Forced Circulation, Haynes Alloy No. 25, Mercury Loop to Study Corrosion Product Separation Techniques

    National Research Council Canada - National Science Library

    Cooper, David

    1965-01-01

    .... Corrosion product separators were included in both the vapor and liquid sections of the system and were evaluated for their effectiveness in reducing problems associated with mass transfer in mercury systems...

  18. New RP-HPLC Method for Separation of Naja haje haje Venom and Studies of its Bactericidal Effect

    National Research Council Canada - National Science Library

    Şerban Andrei Gâz Florea; Diana Ciurca; Anca Mare; Adrian Man; Bogdan Cordoş; Anda-Lavinia Grama; Daniela-Lucia Muntean

    2016-01-01

    .... The venom of Naja haje, an Elapidae member, has been analyzed from this point of view. Understanding the fully biochemical role of its enzymes has determined the scientists to find new separation and identification methods. Objective...

  19. The Preparation and Characterization of INTEC HAW Phase I Composition Variation Study Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Musick, C. A.; Peeler, D. K.; Piepel, G. F.; Scholes, B. A.; Staples, B. A.; Vienna, J. D.

    1999-03-01

    A glass composition variation study (CVS) is in progress to define formulations for the vitrification of high activity waste (HAW) proposed to be separated from dissolved calcine stored at the Idaho National Engineering and Environmental Laboratory (INEEL). Estimates of calcine and HAW compositions prepared in FY97 were used to define test matrix glasses. The HAW composition is of particular interest because high aluminum, zirconium, phosphorous and potassium, and low iron and sodium content places it outside the realm of vitrification experience in the Department of Energy (DOE) complex. Through application of statistical techniques, a test matrix was defined for Phase 1 of the CVS. From this matrix, formulations were systematically selected for preparation and characterization with respect to homogeneity, viscosity, liquidus temperature (TL), and leaching response when subjected to the Product Consistency Test (PCT). Based on the properties determined, certain formulations appear suitable for further development including use in planning Phase 2 of the study. It is recommended that glasses to be investigated in Phase 2 be limited to 3-5 wt % phosphate. The results of characterizing the Phase 1 glasses are presented in this document. A full analysis of the composition-property relationships of glasses being developed for immobilizing HAWs will be performing at the completion of CVS phases. This analysis will be needed for the optimization of the glass formulations of vitrifying HAW. Contributions were made to this document by personnel working at the INEEL, Pacific Northwest National Laboratories (PNNL), and the Savannah River Technology Center (SRTC).

  20. Audiologic characteristics in a sample of recently-separated military Veterans: The Noise Outcomes in Servicemembers Epidemiology Study (NOISE Study).

    Science.gov (United States)

    Gordon, J S; Griest, S E; Thielman, E J; Carlson, K F; Helt, W J; Lewis, M S; Blankenship, C; Austin, D; Theodoroff, S M; Henry, J A

    2017-06-01

    Military Service Members are often exposed to high levels of occupational noise, solvents, and other exposures that can be damaging to the auditory system. Little is known about hearing loss and how it progresses in Veterans following military service. This epidemiology study is designed to evaluate and monitor a cohort of Veterans for 20 years or more to determine how hearing loss changes over time and how those changes are related to noise exposure and other ototoxic exposures encountered during military service. Data reported here are from baseline assessments of the first 100 study participants (84 males; 16 females; mean age 33.5 years; SD 8.8; range 21-58). Each participant was asked to complete a comprehensive audiologic examination and self-report questionnaires regarding sociodemographic characteristics, noise and solvent exposures, health conditions common among post-deployment Veterans, and the social and emotional consequences of hearing loss. For this relatively young cohort, 29% exhibited hearing loss, defined as average hearing threshold >20 dB HL in the conventional audiometric range. Forty-two percent exhibited hearing loss in the extended-high-frequency audiometric range using the same criterion (average hearing threshold >20 dB HL). Certain factors were found to be associated with poorer hearing in both conventional and extended-high-frequency ranges, including age, type of military branch, years of military service, number of military deployments, noise exposure, tinnitus, and a positive screen for post-traumatic stress disorder. Although the majority of participants had hearing within normal limits, 27% reported a self-perceived mild/moderate hearing handicap and 14% reported a significant handicap. Further research is needed to identify a cause for this discrepancy in audiologic results versus self-report. The information obtained from this longitudinal study could be used in future resource planning with the goal of preventing, as much as

  1. Dielectric constant of water as a function of separation in a slab geometry: A molecular dynamics study.

    Science.gov (United States)

    Itoh, Hidenosuke; Sakuma, Hiroshi

    2015-05-14

    Water in confining geometries shows various anomalous properties related to its structure and dynamics compared with bulk water. Here, the dielectric constant of water as a function of separation in a graphite slab geometry was studied using molecular dynamics simulations. The dielectric constants of water were calculated from the orientational polarization of water molecules when an external electric field was applied parallel and normal to the slabs. The reduction of the dielectric constant of water compared with bulk water can be explained by investigating the structure and dynamics of water in slab geometries. We found a preferred orientation of water molecules in the layer closest to the graphite surface. The self-diffusion coefficient distribution of water molecules along the direction normal to the slabs was also computed. Highly mobile water molecules in the intermediate region were generated by the weak hydrogen bonding produced by the preferred orientation of water molecules in the layer. We concluded that the dielectric constant of water in the slab geometry is lower than that of bulk water because of the reduction of the polarization of water and the highly mobile water molecules in the intermediate region arising from the preferred orientation of water molecules.

  2. Extraction and Separation of Active Ingredients in Schisandra chinensis (Turcz. Baill and the Study of their Antifungal Effects.

    Directory of Open Access Journals (Sweden)

    Haijing Yi

    Full Text Available Schisandra chinensis extracts (SEs have traditionally been used as an oriental medicine for the treatment of various human diseases, however, their further application in the biocontrol of plant disease remains poorly understood. This study was conducted to develop eco-friendly botanical pesticides from extracts of S. chinensis and assess whether they could play a key role in plant disease defense. Concentrated active fractions (SE-I, SE-II, and SE-III were obtained from S. chinensis via specific extraction and separation. Then, lignan-like substances, such as Schisanhenol B, were detected via High-Performance Liquid Chromatography-ElectroSpray Ionization-Mass Spectrometry (HPLC-ESI-MS analyses of the active fractions. Moreover, the results from biological tests on colony growth inhibition and spore germination indicated that SE-I, SE-II, and SE-III could inhibit hyphal growth and spore generation of three important plant pathogenic fungi (Monilinia fructicola, Fusarium oxysporum, and Botryosphaeria dothidea. The study of the mechanisms of resistant fungi revealed that the oxidation resistance system, including reactive oxygen species (ROS, malondialdehyde (MDA, catalase (CAT, and superoxide dismutase (SOD, was activated. The expression of genes related to defense, such as pathogenesis-related protein (PR4, α-farnesene synthase (AFS, polyphenol oxidase (PPO, and phenylalanine ammonia lyase (PAL were shown to be up-regulated after treatment with SEs, which suggested an increase in apple immunity and that fruits were induced to effectively defend against the infection of pathogenic fungi (B. dothidea. This study revealed that SEs and their lignans represent promising resources for the development of safe, effective, and multi-targeted agents against pathogenic fungi.

  3. The Eurisol report. A feasibility study for a European isotope-separation-on-line radioactive ion beam facility

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-12-01

    The Eurisol project aims at a preliminary design study of the next-generation European isotope separation on-line (ISOL) radioactive ion beam (RIB) facility. In this document, the scientific case of high-intensity RIBs using the ISOL method is first summarised, more details being given in appendix A. It includes: 1) the study of atomic nuclei under extreme and so-far unexplored conditions of composition (i.e. as a function of the numbers of protons and neutrons, or the so-called isospin), rotational angular velocity (or spin), density and temperature, 2) the investigation of the nucleosynthesis of heavy elements in the Universe, an important part of nuclear astrophysics, 3) a study of the properties of the fundamental interactions which govern the properties of the universe, and in particular of the violation of some of their symmetries, 4) potential applications of RIBs in solid-state physics and in nuclear medicine, for example, where completely new fields could be opened up by the availability of high-intensity RIBs produced by the ISOL method. The proposed Eurisol facility is then presented, with particular emphasis on its main components: the driver accelerator, the target/ion-source assembly, the mass-selection system and post-accelerator, and the required scientific instrumentation. Special details of these components are given in appendices B to E, respectively. The estimates of the costs of the Eurisol, construction and running costs, have been performed in as much details as is presently possible. The total capital cost (installation manpower cost included) of the project is estimated to be of the order of 630 million Euros within 20%. In general, experience has shown that operational costs per annum for large accelerator facilities are about 10% of the capital cost. (A.C.)

  4. Generic Separations and Leaf Languages

    OpenAIRE

    Matthias Galota; Sven Kosub (Hrsg.); Heribert Vollmer

    2017-01-01

    In the early nineties of the previous century, leaf languages were introduced as a means for the uniform characterization of many complexity classes, mainly in the range between P (polynomial time) and PSPACE (polynomial space). It was shown that the separability of two complexity classes can be reduced to a combinatorial property of the corresponding defining leaf languages. In the present paper, it is shown that every separation obtained in this way holds for every generic oracle in the sen...

  5. Systematic analytical characterization of new psychoactive substances: A case study.

    Science.gov (United States)

    Lobo Vicente, Joana; Chassaigne, Hubert; Holland, Margaret V; Reniero, Fabiano; Kolář, Kamil; Tirendi, Salvatore; Vandecasteele, Ine; Vinckier, Inge; Guillou, Claude

    2016-08-01

    New psychoactive substances (NPS) are synthesized compounds that are not usually covered by European and/or international laws. With a slight alteration in the chemical structure of existing illegal substances registered in the European Union (EU), these NPS circumvent existing controls and are thus referred to as "legal highs". They are becoming increasingly available and can easily be purchased through both the internet and other means (smart shops). Thus, it is essential that the identification of NPS keeps up with this rapidly evolving market. In this case study, the Belgian Customs authorities apprehended a parcel, originating from China, containing two samples, declared as being "white pigments". For routine identification, the Belgian Customs Laboratory first analysed both samples by gas-chromatography mass-spectrometry and Fourier-Transform Infrared spectroscopy. The information obtained by these techniques is essential and can give an indication of the chemical structure of an unknown substance but not the complete identification of its structure. To bridge this gap, scientific and technical support is ensured by the Joint Research Centre (JRC) to the European Commission Directorate General for Taxation and Customs Unions (DG TAXUD) and the Customs Laboratory European Network (CLEN) through an Administrative Arrangement for fast recognition of NPS and identification of unknown chemicals. The samples were sent to the JRC for a complete characterization using advanced techniques and chemoinformatic tools. The aim of this study was also to encourage the development of a science-based policy driven approach on NPS. These samples were fully characterized and identified as 5F-AMB and PX-3 using (1)H and (13)C nuclear magnetic resonance (NMR), high-resolution tandem mass-spectrometry (HR-MS/MS) and Raman spectroscopy. A chemoinformatic platform was used to manage, unify analytical data from multiple techniques and instruments, and combine it with chemical and

  6. Preparation and characterization of underwater superoleophobic chitosan/poly(vinyl alcohol) coatings for self-cleaning and oil/water separation

    Science.gov (United States)

    Wang, Qian; Fu, Youjia; Yan, Xiaoxia; Chang, Yanjiao; Ren, Lili; Zhou, Jiang

    2017-08-01

    In this paper, chitosan (CS)/poly(vinyl alcohol) (PVA) coatings cross-linked with glutaraldehyde (GA) were prepared. Effects of the coating composition and NaOH solution treatment on surface morphology and topography were investigated by scanning electron microscope and atomic force microscope. It was found that the process of immersing the CS/PVA coatings into NaOH solution was crucial to enhance rough structure on the coating surface. The rough surface structure and the hydrophilic groups of CS and PVA made the CS/PVA coatings possess underwater superoleophobicity and low adhesion to oil. Oil contact angle of the prepared CS/PVA coatings was up to 161° and slide angle was only 3°. Moreover, the CS/PVA coatings showed stable superoleophobicity in high salt, strong acidic, and alkaline environments as well as underwater self-cleaning property and excellent transparency. The CS/PVA coatings could be used for gravity driven oil/water separation with high efficiency.

  7. Chemical separation of Nd from geological samples for chronological studies using (146)Sm-(142)Nd and (147)Sm-(143)Nd systematics.

    Science.gov (United States)

    Kagami, Saya; Yokoyama, Tetsuya

    2016-09-21

    Sm-Nd dating, which involves long-lived (147)Sm-(143)Nd and short-lived (146)Sm-(142)Nd systematics, has been widely used in the field of geosciences. To obtain precise and accurate ages of geological samples, the determination of highly precise Nd isotope ratios with nearly complete removal of Ce and Sm is indispensable to avoid mass spectral interference. In this study, we developed a three-step column chemistry procedure for separating Nd from geological samples that includes cation exchange chromatography for separating major elements from rare earth elements (REEs), oxidative extraction chromatography using Ln Resin coupled with HNO3 + KBrO3 for separating tetravalent Ce from the remaining REEs, and final purification of Nd using Ln Resin. This method enables high recovery of Nd (>91%) with effective separation of Nd from Ce and Sm (Ce/Nd systematics, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. [Characterization of oncological disease: racional, objectives and methodology - perfil study].

    Science.gov (United States)

    Macedo, Ana; Andrade, Sofia; Moital, Inês; Moreira, António; Pimentel, Francisco Luís; Barroso, Sérgio; Dinis, José; Afonso, Noémia; Bonfill, Xavier

    2008-01-01

    Oncologic disease is one of the main causes of death in Portugal, as well as a high morbidity rate. Over the past few years, these diseases have been targeted with several strategies which aims at optimizing the use of available therapeutic and diagnostic options. Nevertheless, the amount of quantitative information available regarding the disease, patient profile, and treatment and monitoring practices is very low. In order to optimise the implementation of health policies specifically directed at oncologic diseases reliable and up-to-date information is needed, permitting optimisation and balancing of costs and benefits. The PERFIL national epidemiologic study is a multi-centre, retrospective cohort study which aims at evaluating the clinical practice regarding treatment of 6 neoplasias -colorectal, gastric, breast, prostate, lung, and lymphoma, in Portugal, between 2003 and 2007. This study is based upon data collection from the clinical files of patients being followed in the participating centres from 2003 to 2007. Qualitative evaluation (diagnosis and stage) was collected from the clinical records of all patients seen in each participating centre on a given month in each year from 2003 to 2007. The characterization of both patient profile and treatment and monitoring patterns will be based on a far-reaching analysis of 10,000 of those files, selected in a random and stratified sampling. This article describes the PERFIL study rationale, its objectives, and methodology.

  9. Study on two-phase swirling flows in a gas–liquid separator with three pick-off rings

    Energy Technology Data Exchange (ETDEWEB)

    Funahashi, H.; Hayashi, K.; Hosokawa, S.; Tomiyama, A., E-mail: tomiyama@mech.kobe-u.ac.jp

    2016-11-15

    Highlights: • Experiments on swirling flow in a separator with three PORs are carried out. • Flow observation and measurement of liquid film thickness in the barrel are carried out. • Liquid-separation rate and pressure drop at each POR are measured. • Effects of total gas and liquid inflows on separator performance are investigated. - Abstract: Experiments on air-water two-phase swirling flows in a one-fifth scale model of a steam separator with three pick-off rings (PORs) are carried out to investigate characteristics of two-phase swirling flows and separator performance. In addition to flow observation, liquid film thickness, flow rates of separated liquid and pressure drops are measured. The ranges of the gas and liquid volume fluxes, J{sub G} and J{sub L}, tested are 12.0 ⩽ J{sub G} ⩽ 17.8 m/s and 0.05 ⩽ J{sub L} ⩽ 0.11 m/s, respectively. The main conclusions obtained are as follows: (1) the liquid film thicknesses at the PORs are smaller than the gap widths of the PORs under the nominal operating condition, which results in a high liquid-separation rate, (2) the increase in J{sub G} decreases the flow rate of unseparated liquid, whereas the flow rate of unseparated liquid is independent of J{sub L} except for low J{sub G} conditions, under which the liquid film thicknesses at the 2nd and 3rd PORs tend to be larger than the gap widths of PORs, (3) the presence of the 2nd and 3rd PORs realizes high liquid-separation rates by capturing the liquid unseparated at the 1st POR and the pressure drops at the 2nd and 3rd PORs are much smaller than that at the 1st POR, and (4) the pressure drops at the swirler and the 1st POR, which are the main source of the pressure drop of the separator under the nominal operating condition, increase with J{sub G}, whereas J{sub L} increases only the latter.

  10. Synthesis, characterization and evaluation of uniformly sized core-shell imprinted microspheres for the separation trans-resveratrol from giant knotweed

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhaohui, E-mail: zhaohuizhang77@hotmail.com [College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000 (China); State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, 410082 (China); Liu Li; Li Hui [College of Chemistry and Chemical Engineering, Jishou University, Jishou, 416000 (China); Yao Shouzhuo [State Key Laboratory of Chemo/Biosensing and Chemometrics, Hunan University, Changsha, 410082 (China)

    2009-09-15

    A novel core-shell molecularly imprinting microspheres (MIMs) with trans-resveratrol as the template molecule; acrylamide (AA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker, was prepared based on SiO{sub 2} microspheres with surface imprinting technique. These core-shell trans-resveratrol imprinted microspheres were characterized by infrared spectra (IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and high performance liquid chromatography (HPLC). The results showed that these core-shell imprinted microspheres, which take on perfect spherical shape with average shell thickness of 150 nm, exhibit especially selective recognition for trans-resveratrol. These imprinted microspheres were applied as solid-phase extraction materials for selective extraction of trans-resveratrol from giant knotweed extracting solution successfully.

  11. Isolation and Characterization of Chinese Standard Fulvic Acid Sub-fractions Separated from Forest Soil by Stepwise Elution with Pyrophosphate Buffer

    Science.gov (United States)

    Bai, Yingchen; Wu, Fengchang; Xing, Baoshan; Meng, Wei; Shi, Guolan; Ma, Yan; Giesy, John P.

    2015-01-01

    XAD-8 adsorption technique coupled with stepwise elution using pyrophosphate buffers with initial pH values of 3, 5, 7, 9, and 13 was developed to isolate Chinese standard fulvic acid (FA) and then separated the FA into five sub-fractions: FApH3, FApH5, FApH7, FApH9 and FApH13, respectively. Mass percentages of FApH3-FApH13 decreased from 42% to 2.5%, and the recovery ratios ranged from 99.0% to 99.5%. Earlier eluting sub-fractions contained greater proportions of carboxylic groups with greater polarity and molecular mass, and later eluting sub-fractions had greater phenolic and aliphatic content. Protein-like components, as well as amorphous and crystalline poly(methylene)-containing components were enriched using neutral and basic buffers. Three main mechanisms likely affect stepwise elution of humic components from XAD-8 resin with pyrophosphate buffers including: 1) the carboxylic-rich sub-fractions are deprotonated at lower pH values and eluted earlier, while phenolic-rich sub-fractions are deprotonated at greater pH values and eluted later. 2) protein or protein-like components can be desorbed and eluted by use of stepwise elution as progressively greater pH values exceed their isoelectric points. 3) size exclusion affects elution of FA sub-fractions. Successful isolation of FA sub-fractions will benefit exploration of the origin, structure, evolution and the investigation of interactions with environmental contaminants. PMID:25735451

  12. Isolation and Characterization of Chinese Standard Fulvic Acid Sub-fractions Separated from Forest Soil by Stepwise Elution with Pyrophosphate Buffer

    Science.gov (United States)

    Bai, Yingchen; Wu, Fengchang; Xing, Baoshan; Meng, Wei; Shi, Guolan; Ma, Yan; Giesy, John P.

    2015-03-01

    XAD-8 adsorption technique coupled with stepwise elution using pyrophosphate buffers with initial pH values of 3, 5, 7, 9, and 13 was developed to isolate Chinese standard fulvic acid (FA) and then separated the FA into five sub-fractions: FApH3, FApH5, FApH7, FApH9 and FApH13, respectively. Mass percentages of FApH3-FApH13 decreased from 42% to 2.5%, and the recovery ratios ranged from 99.0% to 99.5%. Earlier eluting sub-fractions contained greater proportions of carboxylic groups with greater polarity and molecular mass, and later eluting sub-fractions had greater phenolic and aliphatic content. Protein-like components, as well as amorphous and crystalline poly(methylene)-containing components were enriched using neutral and basic buffers. Three main mechanisms likely affect stepwise elution of humic components from XAD-8 resin with pyrophosphate buffers including: 1) the carboxylic-rich sub-fractions are deprotonated at lower pH values and eluted earlier, while phenolic-rich sub-fractions are deprotonated at greater pH values and eluted later. 2) protein or protein-like components can be desorbed and eluted by use of stepwise elution as progressively greater pH values exceed their isoelectric points. 3) size exclusion affects elution of FA sub-fractions. Successful isolation of FA sub-fractions will benefit exploration of the origin, structure, evolution and the investigation of interactions with environmental contaminants.

  13. Cobalt-doped nanohydroxyapatite: synthesis, characterization, antimicrobial and hemolytic studies

    Energy Technology Data Exchange (ETDEWEB)

    Tank, Kashmira P., E-mail: kashmira_physics@yahoo.co.in [Saurashtra University, Crystal Growth Laboratory, Physics Department (India); Chudasama, Kiran S.; Thaker, Vrinda S. [Saurashtra University, Bioscience Department (India); Joshi, Mihir J., E-mail: mshilp24@rediffmail.com [Saurashtra University, Crystal Growth Laboratory, Physics Department (India)

    2013-05-15

    Hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}; HAP) is a major mineral component of the calcified tissues, and it has various applications in medicine and dentistry. In the present investigation, cobalt-doped hydroxyapatite (Co-HAP) nanoparticles were synthesized by surfactant-mediated approach and characterized by different techniques. The EDAX was carried out to estimate the amount of doping in Co-HAP. The transmission electron microscopy result suggested the transformation of morphology from needle shaped to spherical type on increasing the doping concentration. The powder XRD study indicated the formation of a new phase of brushite for higher concentration of cobalt. The average particle size and strain were calculated using Williamson-Hall analysis. The average particle size was found to be 30-60 nm. The FTIR study confirmed the presence of various functional groups in the samples. The antimicrobial activity was evaluated against four organisms Pseudomonas aeruginosa and Shigella flexneri as Gram negative as well as Micrococcus luteus and Staphylococcus aureus as Gram positive. The hemolytic test result suggested that all samples were non-hemolytic. The photoluminescence study was carried out to identify its possible applicability as a fluorescent probe.

  14. Synthesis, characterization and antimicrobial studies of Schiff base complexes

    Science.gov (United States)

    Zafar, Hina; Ahmad, Anis; Khan, Asad U.; Khan, Tahir Ali

    2015-10-01

    The Schiff base complexes, MLCl2 [M = Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)] have been synthesized by the template reaction of respective metal ions with 2-acetylpyrrole and 1,3-diaminopropane in 1:2:1 M ratio. The complexes have been characterized by elemental analyses, ESI - mass, NMR (1H and 13C), IR, XRD, electronic and EPR spectral studies, magnetic susceptibility and molar conductance measurements. These studies show that all the complexes have octahedral arrangement around the metal ions. The molar conductance measurements of all the complexes in DMSO indicate their non-electrolytic nature. The complexes were screened for their antibacterial activity in vitro against Gram-positive (Streptococcus pyogenes) and Gram-negative (Klebsiella pneumoniae) bacteria. Among the metal complexes studied the copper complex [CuLCl2], showed highest antibacterial activity nearly equal to standard drug ciprofloxacin. Other complexes also showed considerable antibacterial activity. The relative order of activity against S. Pyogenes is as Cu(II) > Zn(II) > Co(II) = Fe(II) > Ni(II) and with K. Pneumonia is as Cu(II) > Co(II) > Zn(II) > Fe(II) > Ni(II).

  15. Gulf stream separation dynamics

    Science.gov (United States)

    Schoonover, Joseph

    Climate models currently struggle with the more traditional, coarse ( O(100 km) ) representation of the ocean. In these coarse ocean simulations, western boundary currents are notoriously difficult to model accurately. The modeled Gulf Stream is typically seen exhibiting a mean pathway that is north of observations, and is linked to a warm sea-surface temperature bias in the Mid-Atlantic Bight. Although increased resolution ( O(10 km) ) improves the modeled Gulf Stream position, there is no clean recipe for obtaining the proper pathway. The 70 year history of literature on the Gulf Stream separation suggests that we have not reached a resolution on the dynamics that control the current's pathway just south of the Mid-Atlantic Bight. Without a concrete knowledge on the separation dynamics, we cannot provide a clean recipe for accurately modeling the Gulf Stream at increased resolutions. Further, any reliable parameterization that yields a realistic Gulf Stream path must express the proper physics of separation. The goal of this dissertation is to determine what controls the Gulf Stream separation. To do so, we examine the results of a model intercomparison study and a set of numerical regional terraforming experiments. It is argued that the separation is governed by local dynamics that are most sensitive to the steepening of the continental shelf, consistent with the topographic wave arrest hypothesis of Stern (1998). A linear extension of Stern's theory is provided, which illustrates that wave arrest is possible for a continuously stratified fluid.

  16. Unity Through Separation

    DEFF Research Database (Denmark)

    Dabelsteen, Hans B.

    This PhD thesis asks how we can conceptualize the current separation doctrine of religion and politics in a country like Denmark, where the structure of the established church and peoplehood overlap. In order to answer this question, Hans Bruun Dabelsteen maps the current discussion of secularism...... into the principle of treating everybody equally (with religious freedom, equality and Danish peoplehood as the most important principles adjacent to secularism). In a study of the historical roots of the separation doctrine and two current policy cases (same-sex marriage and reforms of church governance...

  17. Degradation Characterization of Aliphatic POLYESTERS—IN Vitro Study

    Science.gov (United States)

    Vieira, A. C.; Vieira, J. C.; Guedes, R. M.; Marques, A. T.

    2008-08-01

    The most popular and important biodegradable polymers are aliphatic polyesters, such as polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone (PCL), polyhydoxyalkanoates (PHA's) and polyethylene oxide (PEO). However, each of these has some shortcomings which restrict its applications. Blending techniques are an extremely promising approach which can improve or tune the original properties of the polymers[1]. Aliphatic polyesters are a central class of biodegradable polymers, because hydrolytic and/or enzymatic chain cleavage of these materials leads to α-hydroxyacids, which in most cases are ultimately metabolized in human body. This is particularly useful for controlled release devices and for other biomedical applications like suture fibers and ligaments. For aliphatic polyesters, hydrolysis rates are affected by the temperature, molecular structure, and ester group density as well as by the species of enzyme used. The degree of crystallinity may be a crucial factor, since enzymes attack mainly the amorphous domains of a polymer. Four different aliphatic polyesters were characterized in terms of degradation. Sutures fibers of PGA-PCL, PGA, PLA-PCL and PDO were used in this study. Weight loss, pH, molecular weight, crystallinity and strength were measured after six stages of incubation in distilled water, physiological saline and phosphate buffer solution (PBS). Degradation rate was determined, using a first order kinetic equation for all materials in the three incubation media. A relatively wide range of mechanical properties and degradation rates were observed among the materials studied. PBS was the most aggressive environment for the majority of cases.

  18. Characterization of burns using hyperspectral imaging technique - a preliminary study.

    Science.gov (United States)

    Calin, Mihaela Antonina; Parasca, Sorin Viorel; Savastru, Roxana; Manea, Dragos

    2015-02-01

    Surgical burn treatment depends on accurate estimation of burn depth. Many methods have been used to asses burns, but none has gained wide acceptance. Hyperspectral imaging technique has recently entered the medical research field with encouraging results. In this paper we present a preliminary study (case presentation) that aims to point out the value of this optical method in burn wound characterization and to set up future lines of investigation. A hyperspectral image of a leg and foot with partial thickness burns was obtained in the fifth postburn day. The image was analyzed using linear spectral unmixing model as a tool for mapping the investigated areas. The article gives details on the mathematical bases of the interpretation model and correlations with clinical examination pointing out the advantages of hyperspectral imaging technique. While the results were encouraging, further more extended and better founded studies are being prepared before recognizing hyperspectral imaging technique as an applicable method of burn wound assessment. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  19. Wastewater characterization of IPEN facilities - a preliminary study

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Lucilena R.; Goncalves, Cristina; Terazan, Wagner R.; Cotrim, Marycel E.B.; Pires, Maria Aparecida F., E-mail: lrmonteiro@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    As part of IPEN's Environmental Monitoring Program, wastewater sample collection and analysis was implemented on a daily basis. CQMA- Centro de Quimica e Meio Ambiente was responsible for the determination of total, fixed and volatile solids, pH, metals (as Al, Sb, Ba, Cd, Pb, Co, Cu, Cr, Hg, Mo, Ni, Ag, Na, Zn, Ca, Mg, Be, Sn, Li, K, Sr, Ti and V), semimetals (As, B, Se and Si) and anions (such as chloride, nitrate, sulfate and fluoride). The results were compared to the legal values established by the Sao Paulo State regulation 8,468/76, which defines the maximum permitted values for most of the studied substances in wastewater, aiming its releasing in public wastewater treatment system. The evaluation of this parameters concentration on Ipen's effluent implies that 50% of the wastewater corresponds to organic matter due to the sanitary load and inorganic macro elements, mainly as sodium, potassium, calcium. The only parameter not found in accordance with Brazilian legislation was pH in four out of the one hundred and seven samples collected throughout 2009 (2.8% of the samples analyzed). This preliminary study showed the effluents generated at Ipen's facility is characterized by the presence of organic matter and macro elements, commonly found in sanitary wastewater and it is in compliance with Sao Paulo regulations. (author)

  20. New RP-HPLC Method for Separation of Naja haje haje Venom and Studies of its Bactericidal Effect

    Directory of Open Access Journals (Sweden)

    Gâz Florea Şerban Andrei

    2016-03-01

    Full Text Available Background: Snake venom is a complex mixture of biologically active substances. Some peptides and proteins from snake have already demonstrated their therapeutically potential. The venom of Naja haje, an Elapidae member, has been analyzed from this point of view. Understanding the fully biochemical role of its enzymes has determined the scientists to find new separation and identification methods.

  1. New RP-HPLC Method for Separation of Naja haje haje Venom and Studies of its Bactericidal Effect

    OpenAIRE

    Gâz Florea Şerban Andrei; Ciurca Diana; Mare Anca; Man Adrian; Cordoş Bogdan; Grama Anda-Lavinia; Muntean Daniela-Lucia

    2016-01-01

    Background: Snake venom is a complex mixture of biologically active substances. Some peptides and proteins from snake have already demonstrated their therapeutically potential. The venom of Naja haje, an Elapidae member, has been analyzed from this point of view. Understanding the fully biochemical role of its enzymes has determined the scientists to find new separation and identification methods.

  2. Characterizing parameters of Jatropha curcas cell cultures for microgravity studies

    Science.gov (United States)

    Vendrame, Wagner A.; Pinares, Ania

    2013-06-01

    Jatropha (Jatropha curcas) is a tropical perennial species identified as a potential biofuel crop. The oil is of excellent quality and it has been successfully tested as biodiesel and in jet fuel mixes. However, studies on breeding and genetic improvement of jatropha are limited. Space offers a unique environment for experiments aiming at the assessment of mutations and differential gene expression of crops and in vitro cultures of plants are convenient for studies of genetic variation as affected by microgravity. However, before microgravity studies can be successfully performed, pre-flight experiments are necessary to characterize plant material and validate flight hardware environmental conditions. Such preliminary studies set the ground for subsequent spaceflight experiments. The objectives of this study were to compare the in vitro growth of cultures from three explant sources (cotyledon, leaf, and stem sections) of three jatropha accessions (Brazil, India, and Tanzania) outside and inside the petriGAP, a modified group activation pack (GAP) flight hardware to fit petri dishes. In vitro jatropha cell cultures were established in petri dishes containing a modified MS medium and maintained in a plant growth chamber at 25 ± 2 °C in the dark. Parameters evaluated were surface area of the explant tissue (A), fresh weight (FW), and dry weight (DW) for a period of 12 weeks. Growth was observed for cultures from all accessions at week 12, including subsequent plantlet regeneration. For all accessions differences in A, FW and DW were observed for inside vs. outside the PetriGAPs. Growth parameters were affected by accession (genotype), explant type, and environment. The type of explant influenced the type of cell growth and subsequent plantlet regeneration capacity. However, overall cell growth showed no abnormalities. The present study demonstrated that jatropha in vitro cell cultures are suitable for growth inside PetriGAPs for a period of 12 weeks. The parameters

  3. Selectivity of bis-triazinyl bipyridine ligands for americium(III) in Am/Eu separation by solvent extraction. Part 1. Quantum mechanical study on the structures of BTBP complexes and on the energy of the separation.

    Science.gov (United States)

    Narbutt, Jerzy; Oziminski, Wojciech P

    2012-12-21

    Theoretical studies were carried out on two pairs of americium and europium complexes formed by tetra-N-dentate lipophilic BTBP ligands, neutral [ML(NO(3))(3)] and cationic [ML(2)](3+) where M = Am(III) or Eu(III), and L = 6,6'-bis-(5,6-diethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine (C2-BTBP). Molecular structures of the complexes have been optimized at the B3LYP/6-31G(d) level and total energies of the complexes in various media were estimated using single point calculations performed at the B3LYP/6-311G(d,p) and MP2/6-311G(d,p) levels of theory. In the calculations americium and europium ions were treated using pseudo-relativistic Stuttgart-Dresden effective core potentials and the accompanying basis sets. Selectivity in solvent extraction separation of two metal ions is a co-operative function of contributions from all extractable metal complexes, which depend on physico-chemical properties of each individual complex and on its relative amount in the system. Semi-quantitative analysis of BTBP selectivity in the Am/Eu separation process, based on the contributions from the two pairs of Am(III) and Eu(III) complexes, has been carried out. To calculate the energy of Am/Eu separation, a model of the extraction process was used, consisting of complex formation in water and transfer of the formed complex to the organic phase. Under the assumptions discussed in the paper, this simple two-step model results in reliable values of the calculated differences in the energy changes for each pair of the Am/Eu complexes in both steps of the process. The greater thermodynamic stability (in water) of the Am-BTBP complexes, as compared with the analogous Eu species, caused by greater covalency of the Am-N than Eu-N bonds, is most likely the main reason for BTBP selectivity in the separation of the two metal ions. The other potential reason, i.e. differences in lipophilic properties of the analogous complexes of Am and Eu, is less important with regard to this selectivity.

  4. An ultra scale-down methodology to characterize aspects of the response of human cells to processing by membrane separation operations.

    Science.gov (United States)

    Masri, Maria Fernanda; Lawrence, Kate; Wall, Ivan; Hoare, Michael

    2017-06-01

    Tools that allow cost-effective screening of the susceptibility of cell lines to operating conditions which may apply during full scale processing are central to the rapid development of robust processes for cell-based therapies. In this paper, an ultra scale-down (USD) device has been developed for the characterization of the response of a human cell line to membrane-based processing, using just a small quantity of cells that is often all that is available at the early discovery stage. The cell line used to develop the measurements was a clinically relevant human fibroblast cell line. The impact was evaluated by cell damage on completion of membrane processing as assessed by trypan blue exclusion and release of intracellular lactate dehydrogenase (LDH). Similar insight was gained from both methods and this allowed the extension of the use of the LDH measurements to examine cell damage as it occurs during processing by a combination of LDH appearance in the permeate and mass balancing of the overall operation. Transmission of LDH was investigated with time of operation and for the two disc speeds investigated (6,000 and 10,000 rpm or ϵmax  ≈ 1.9 and 13.5 W mL(-1) , respectively). As expected, increased energy dissipation rate led to increased transmission as well as significant increases in rate and extent of cell damage. The method developed can be used to test the impact of varying operating conditions and cell lines on cell damage and morphological changes. Biotechnol. Bioeng. 2017;114: 1241-1251. © 2017 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc. © 2017 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

  5. Evaluating the performance of different multicolumn setups for chromatographic separation of proteins on hydrophobic interaction chromatography media by a numerical study.

    Science.gov (United States)

    Bochenek, Roman; Marek, Wojciech; Piątkowski, Wojciech; Antos, Dorota

    2013-08-02

    A theoretical study has been performed on the effectiveness of isolating a target component out of a multi-component protein mixture using different arrangements of chromatographic columns. Three continuous systems have been considered which were able to perform solvent gradient separations, such as: open loop simulated moving bed, countercurrent solvent gradient purification and carousel multicolumn setup. The performance of the continuous processes was examined with respect to productivity, yield and eluent consumption and compared to a single-column batch system. As a case study separation of a ternary mixture of proteins on HIC media has been selected. Two separation problems have been analyzed referring to the situation when the target component was the most strongly adsorbed as well as when it exhibited intermediate adsorption strength. A mathematical model has been used to simulate the process dynamics and to optimize operating conditions for the separation. The numerical study indicated that batch column arrangements can outperform SMB-based configurations regarding all performance indicators considered, which has been attributed to solvent mixing in the recycled streams and distortion of the gradient shape in SMB units. It has been concluded that the performance of complex multicolumn systems should be verified vs. batch column operations prior to the realization of the separation process. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Study of the actinide-lanthanide separation from nuclear waste by a new pyrochemical process; Etude de la separation actinides-lanthanides des dechets nucleaires par un procede pyrochimique nouveau

    Energy Technology Data Exchange (ETDEWEB)

    Lemort, F. [CEA Marcoule, Departement de Retraitement, des Dechets et du Demantelement, 30 - Bagnols-sur-Ceze (France)]|[Institut National Polytechnique, 38 - Grenoble (France)

    1997-01-01

    The theoretical extraction and separation of platinoids, actinides and lanthanides is allowed by thermodynamic using two adapted reducing agents: zinc and magnesium. Thereby, a pyrochemical method for the nuclear waste processing has been devised. The high temperature handling of the elements in fluoride forms and their processing by a reactive metallic phase required special precautions. The study of the behavior of matter in exploratory systems allowed the development of an experimental technology for the treatment and contacting of phases. The thermodynamical analysis of the experimental results shows the feasibility of the process. A model was developed to predict the distribution coefficients of zirconium, uranium and lanthanum as a function of the system composition. An estimation method was proposed in order to evaluate the distribution coefficients in diluted solution of all the actinides and lanthanides existing in the fission products between LiF CaF{sub 2} and Zn-Mg at 720 deg C. Coupled with the experimental results, the estimates results may be extrapolated to concentrated solutions allowing predictions of the separation of all actinides and lanthanides. The rapidity of element transfer is induced by a thermal effect caused by the high exothermicity of the reduction by magnesium. The kinetic coefficients have been linked with the reduction enthalpy of each element. Moreover, the kinetics seem limited by chemical reaction and not by mass transfer. (author) 66 refs.

  7. Separation of heavy metal from water samples--The study of the synthesis of complex compounds of heavy metal with dithiocarbamates.

    Science.gov (United States)

    Kane, Sonila; Lazo, Pranvera; Ylli, Fatos; Stafilov, Trajce; Qarri, Flora; Marku, Elda

    2016-01-01

    The toxicity and persistence of heavy metal (HM) ions may cause several problems to marine organisms and human beings. For this reason, it is growing the interest in the chemistry of sulphur donor ligands such as dithiocarbamates (DDTC), due to their applications particularly in analytical chemistry sciences. The aim of this work has been the study of heavy metal complexes with DDTC and their application in separation techniques for the preconcentration and/or removing of heavy metals from the water solutions or the water ecosystems prior to their analysis. The HM-DDTC complexes were prepared and characterized by elemental analysis, FTIR and UV-Vis spectroscopic methods. The elemental analysis and the yield of the synthesis (97.5-99.9%) revealed a good purity of the complexes. High values of complex formation yields of HM-DDTC complexes is an important parameter for quantitatively removing/and or preconcentration of heavy metal ions from water solution even at low concentration of heavy metals. Significant differences founded between the characteristic parameters of UV/Vis (λmax and ϵmax) and FTIR absorption spectra of the parent DDTC and HM-DDTC complexes revealed the complex formation. The presence of the peaks at the visible spectral zone is important to M(nd(10-m))-L electron charge transfer of the new complexes. The (C=N) (1450-1500 cm(-1)) and the un-splitting (C-S) band (950-1002 cm(-1)) in HM-DDTC FTIR spectra are important to the identification of their bidentate mode (HM[S2CNC4H10]2). The total CHCl3 extraction of trace level heavy metals from water samples after their complex formation with DDTC is reported in this article.

  8. [Synthesis, characterization and study on vibration spectra of potassium triborate].

    Science.gov (United States)

    Zhang, Jin-Ping; Sun, Yong; Yang, Gang; Li, Zuo-Hu

    2007-07-01

    Potassium triborate was synthesized with potassium carbonate and boric acid by controlling suitable feed mixture ratio, reaction temperature and dehydration temperature in the self-designed boiling reactor. According to chemical analysis, the formula of the synthetics was monohydrate potassium triborate (KB3O5 x H2O). It's structure was characterized by XRD, FTIR, Raman and TG, and it was found by XRD analysis that the synthetics was amorphous solid. FTIR and Raman spectroscopy anal-ysis show that three coordination B(3) -O bond, four coordination B(4) -O bond, and hydroxy and triborate anions existed in the formula of the synthetics. Thermogravimetric (TG) analysis show that the groups which can lose mono-water existed in the formula of the synthetics, and structural formula of the synthetics was deduced as K[B3O4 (OH)2]. Vibration spectra of the synthetics were studied, including FTIR and Raman spectroscopy. Vibration absorption peaks of some main groups of the synthetics were investigated, including three coordination B(3) -O bond and four coordination B(4) -O bond that are the main existing forms of boron atoms in the synthetics as well as other groups, and each vibration absorption peak was assigned.

  9. Characterization of Awassi lamb fattening systems: a Syrian case study.

    Science.gov (United States)

    Hartwell, Birgitte Wiedemann; Iñiguez, Luis; Mueller, Joaquin; Wurzinger, Maria; Knaus, W F

    2010-10-01

    Intensive lamb fattening systems are evolving in developing Middle Eastern countries due to high demand for lambs at favorable prices; however, little is known about their characteristics and constraints. A survey was conducted in Syria involving 241 farmers to characterize the fattening production systems and main constraints, with emphasis on feeding, management, labor, and marketing. Most farmers (90%) considered the income from fattening to be from medium to high, and 57% expressed that lamb fattening along with alternative income sources compose the family's livelihood strategies. Fattening systems offer employment to family members. Market price was the main decision factor to buy and sell lambs, but this was only part of various marketing aspects. Male lambs usually bought at markets at the mean age of 4 months (mean weight of 31 kg) are sold after fattening at a 50-60 kg weight range. The average yearly fattening cycle was 2.7 batches, and the average number of lambs per batch was 232. For 65% (n = 241) of the farmers the major constraint to fattening was feeding cost, and for about a half of farmers (51%, n = 241), disease outbreaks and prices for veterinarian services constituted the second important constraint. Research on least-cost fattening diets and curbing disease problems to increase farmer's income margins is needed. It is expected that due to existing commonalities, the information emerging from this study regarding major constraints to Awassi lamb fattening systems could be useful for an across-synthesis on Awassi fattening production in the region.

  10. Preparation, physical characterization and pharmacokinetic study of paclitaxel nanocrystals.

    Science.gov (United States)

    Wei, Lisha; Ji, Yanxia; Gong, Wei; Kang, Zhenqiao; Meng, Meng; Zheng, Aiping; Zhang, Xiaoyan; Sun, Jianxu

    2015-01-01

    Paclitaxel (PTX) is a natural broad-spectrum anticancer drug with poor aqueous solubility. PTX nanocrystals were formulated to improve the water solubility, and PTX nanosuspensions were prepared using anti-solvent precipitation, and then organic solvent and surfactants were removed by filtering through a vacuum system. The physical characterization of PTX nanocrystals were measured by transmission electron microscope, X-ray diffraction and differential scanning calorimetry. In addition, saturation solubility, in vitro release, stability and pharmacokinetic characteristics were examined. The average particle size of PTX nanocrystals was ∼200 nm, and they had a stable potential and a uniform distribution. Paclitaxel nanocrystals can effectively improve drug solubility and in vitro release. PTX pharmacokinetic and tissue distribution studies were compared after intravenous administration of nanocrystals versus a commercial injection formulation. PTX nanocrystals were rapidly distributed with a longer elimination phase. Moreover, tissue distribution indicated that PTX nanocrystals are mainly absorbed by the liver and spleen and may offer reduced renal and cardiovascular toxicity which may reduce side effects.

  11. Spectroscopic studies of anthracyclines: Structural characterization and in vitro tracking.

    Science.gov (United States)

    Szafraniec, Ewelina; Majzner, Katarzyna; Farhane, Zeineb; Byrne, Hugh J; Lukawska, Malgorzata; Oszczapowicz, Irena; Chlopicki, Stefan; Baranska, Malgorzata

    2016-12-05

    A broad spectroscopic characterization, using ultraviolet-visible (UV-vis) and Fourier transform infrared absorption as well as Raman scattering, of two commonly used anthracyclines antibiotics (DOX) daunorubicin (DNR), their epimers (EDOX, EDNR) and ten selected analogs is presented. The paper serves as a comprehensive spectral library of UV-vis, IR and Raman spectra of anthracyclines in the solid state and in solution. The particular advantage of Raman spectroscopy for the measurement and analysis of individual antibiotics is demonstrated. Raman spectroscopy can be used to monitor the in vitro uptake and distribution of the drug in cells, using both 488nm and 785nm as source wavelengths, with submicrometer spatial resolution, although the cellular accumulation of the drug is different in each case. The high information content of Raman spectra allows studies of the drug-cell interactions, and so the method seems very suitable for monitoring drug uptake and mechanisms of interaction with cellular compartments at the subcellular level. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Glycosaminoglycan blotting and detection after electrophoresis separation.

    Science.gov (United States)

    Volpi, Nicola; Maccari, Francesca

    2015-01-01

    Separation of glycosaminoglycans (GAGs) by electrophoresis and their characterization to the microgram level are integral parts of biochemical research. Their blotting on membranes after electrophoresis offers the advantage to perform further analysis on single separated species such as identification with antibodies and/or recovery of single band. A method for the blotting and immobilizing of several nonsulfated and sulfated complex GAGs on membranes made hydrophilic and positively charged by cationic detergent after their separation by conventional agarose-gel electrophoresis is illustrated. This approach to the study of these complex macromolecules utilizes the capacity of agarose-gel electrophoresis to separate single species of polysaccharides from mixtures and the membrane technology for further preparative and analytical uses. Nitrocellulose membranes are derivatized with the cationic detergent cetylpyridinium chloride (CPC) and mixtures of GAGs are capillary blotted after their separation in agarose-gel electrophoresis. Single purified species of variously sulfated polysaccharides are transferred on derivatized membranes with an efficiency of 100 % and stained with alcian blue (irreversible staining) and toluidine blue (reversible staining). This enables a lower amount limit of detection of 0.1 μg. Nonsulfated polyanions, for example hyaluronic acid (HA), may also be transferred to membranes with a limit of detection of approximately 0.1-0.5 μg after irreversible or reversible staining. The membranes may be stained with reversible staining and the same lanes used for immunological detection or other applications.

  13. A high-intensity low-momentum separated antiproton beam for the study of annihilations at rest

    CERN Document Server

    Bassompierre, G; Dalpiaz, P; Dalpiaz, P F; Ferro-Luzzi, M; Gissinger, G; Jacquey, S; Peroni, C; Schmitt, F M; Schneegans, M; Tecchio, L B

    1977-01-01

    The main features of the low-momentum separated antiproton beam built at the CERN Proton Synchrotron to allow the stopping of a large number of antiprotons are described. An effective stopping rate of 1000 antiproton per 10/sup 12/ protons on the Ps internal target is obtained. Results of the measurement of the rate of reaction pp to h /sup +/h/sup -/ in a 50 cm long liquid hydrogen target are given to illustrate the stopping and monitoring techniques. (6 refs).

  14. Study of β-galactosidase activity in Lactobacilli separated from milk and cheese by biochemical and PCR methods

    OpenAIRE

    zohre bahadori; jamile norozi; abas akhavan sepahi; jahangir sabzevari; roya razavipoor

    2010-01-01

    In some people the inadequate amount of Beta-galactosidase enzyme, in layer of villous epithelium of the small intestine, causes the disorder of lactose intolerance. This examination was done to observe the existence of Beta-galactosidase enzyme that is produced by separated Lactobacillus from samples of dairy products (milk and cheese). Materials and Methods: Pasteurized and local samples of milk and cheese were perchased from Lorestan,Ilam and Hamedan provinces. By keeping t...

  15. Synthesis, characterization, spectral, thermal analysis and computational studies of thiamine complexes

    Science.gov (United States)

    Masoud, Mamdouh S.; Ghareeb, Doaa A.; Ahmed, Shahenda Sh.

    2017-06-01

    Thiamine metal complexes were synthesized and characterized by elemental analysis, IR, electronic spectra, magnetic susceptibility, ESR spectra of Cu(II) complex and EDX for structural investigation of the complexes to know their geometries and mode of bonding. All the manganese, iron, copper, zinc, tungsten and mercury complexes are with octahedral geometry, while cobalt and nickel complexes are with tetrahedral geometry. The selenium and palladium complexes are with square planner geometry, while vanadium complex with stoichiometry (2:1) is with square pyramidal geometry. The thermal properties of the complexes were examined. The kinetic thermodynamic parameters were estimated from the TGA and DTA curves. Molecular modeling of the ligand and its complexes was performed using PC computer to give extra spot lights on the bonding properties of these compounds. Some theoretical studies were carried out to obtain the charges, bond lengths, bond angles and dihedral angles, energies of highest occupied molecular orbital (EHOMO), energies of lowest unoccupied molecular orbital (ELUMO), the separation energy (ΔE), chemical potential, electronegativity, hardness, softness, ionization potential and electron affinity of the studied ligand and its complexes. Correlation analysis was done to explore the relationships between some different parameters of the studied complexes.

  16. Physicochemical characterization and solubility enhancement studies of allopurinol solid dispersions

    Directory of Open Access Journals (Sweden)

    Jagdale Swati Changdeo

    2011-09-01

    Full Text Available Allopurinol is a commonly used drug in the treatment of chronic gout or hyperuricaemia associated with treatment of diuretic conditions. One of the major problems with the drug is that it is practically insoluble in water, which results in poor bioavailability after oral administration. In the present study, solid dispersions of allopurinol were prepared by solvent evaporation, kneading method, co-precipitation method, co-grinding method and closed melting methods to increase its water solubility. Hydrophilic carriers such as polyvinylpyrrolidone, polyethylene glycol 6000 were used in the ratio of 1:1, 1:2 and 1:4 (drug to carrier ratio. The aqueous solubility of allopurinol was favored by the presence of both polymers. These new formulations were characterized in the liquid state by phase solubility studies and in the solid state by differential scanning calorimetry, powder X-ray diffraction, UV and Fourier Transform Infrared spectroscopy. Solid state characterizations indicated that allopurinol was present as an amorphous material and entrapped in polymer matrix. In contrast to the very slow dissolution rate of pure allopurinol, the dispersion of the drug in the polymers considerably enhanced the dissolution rate. Solid dispersion prepared with polyvinylpyrrolidone showed highest improvement in wettability and dissolution rate of allopurinol. Mathematical modeling of in vitro dissolution data indicated the best fitting with Korsemeyer-Peppas model and the drug release kinetics primarily as Non-Fickian diffusion. Therefore, the present study showed that polyvinylpyrrolidone and polyethylene glycol 6000 have a significant solubilizing effect on allopurinol.Alopurinol é fármaco comumente utilizado no tratamento de gota crônica ou hiperuricemia associada com o tratamento em condições diuréticas. Um dos maiores problemas com o fármaco é que este é praticamente insolúvel em água, o que resulta em baixa biodisponibilidade na administra

  17. Separation, characterization, and quantitation of process-related substances of the anti-hypertensive drug doxazosin mesylate by reversed-phase LC with PDA and ESI-MS as detectors.

    Science.gov (United States)

    Nageswara Rao, R; Nagaraju, D; Das, A K; Jena, Nivedita

    2007-02-01

    A simple and rapid reversed-phase liquid chromatography (LC) method with photodiode array (PDA) and electrospray ionization (ESI)-mass spectrometry (MS) as detectors was developed and validated to separate, identify, and quantitate the related substances of Doxazosin mesylate (DXZN) for monitoring the reactions involved during process development. The high-performance liquid chromatography profiles of related-substances of DXZN are used as fingerprints to follow the procedures used in the manufacturing units. The separation is accomplished on an Inertsil ODS-3 column with acetonitrile-ammonium acetate (10 mM, pH 4.0) as the mobile phase, using a gradient elution mode and monitoring the eluents by a photodiode array detector at 265 nm at ambient temperature. LC-ESI-MS-MS is used to identify the additional impurities formed during the synthesis. The identified impurities were synthesized and characterized by UV, Fourier transform-IR, 1H NMR, and MS data. The detection limits for the impurities are 0.74 - 4.14 x 10(-9) g, and the method is found to be suitable not only for the monitoring of synthetic reactions, but also for quality assurance of DXZN in bulk drugs and formulations.

  18. Gas separations using inorganic membranes

    Energy Technology Data Exchange (ETDEWEB)

    Egan, B.Z.; Singh, S.P.N. [Oak Ridge National Lab., TN (United States); Fain, D.E.; Roettger, G.E.; White, D.E. [Oak Ridge K-25 Site, TN (United States)

    1992-04-01

    This report summarizes the results from a research and development program to develop, fabricate, and evaluate inorganic membranes for separating gases at high temperatures and pressures in hostile process environments encountered in fossil energy conversion processes such as coal gasification. The primary emphasis of the research was on the separation and recovery of hydrogen from synthesis gas. Major aspects of the program included assessment of the worldwide research and development activity related to gas separations using inorganic membranes, identification and selection of candidate membrane materials, fabrication and characterization of membranes using porous membrane technology developed at the Oak Ridge K-25 Site, and evaluation of the separations capability of the fabricated membranes in terms of permeabilities and fluxes of gases.

  19. Spectroscopic Studies on the Characterization of a Persian Playing Card.

    Science.gov (United States)

    Holakooei, Parviz; Niknejad, Maryam; Vaccaro, Carmela

    2016-01-01

    This paper presents the results of our investigations on a playing card preserved at The Mūzih-i Āynih va Rushanāī in Yazd, Iran. Conducting micro X-ray fluorescence spectrometry (μ-XRF), micro-Raman spectroscopy (μ-Raman), infrared reflectography (IRR), ultraviolet fluorescence photography, radiography, and optical microscopy, various paints applied on the playing card were identified. According to our analytical studies, red, green, blue, black, and gold-like metallic paints were identified to be a red monoazo pigment (β-naphthol PR 53:1), chrome green, artificial ultramarine blue, carbon black, and brass powder (Dutch metal powder), respectively, dating the playing card to 1895 onward based on the manufacturing date of the red monoazo pigment. Barite was also shown to be mixed with the pigments as an extender. On the other hand, the portrait's face of the playing card was peculiarly blackened. Our analytical approach toward characterizing the blackened face showed that the black paint was achieved by carbon black and, in other words, the face was not blackened due to the darkening of Pb-bearing pigments. Moreover, it was shown that there was no underdrawing under the black face and the black paint was most probably executed in the same time with the other paints. Considering the possible use of the playing card, it was suggested not to remove the blackened face in the cleaning process since the black paint was a part of the integrity of the playing card. © The Author(s) 2015.

  20. Determination of the prevalence of subclinical endometritis and evaluation of molecular characterization of Escherichia coli (E-coli separated of them in mares repeat breeder in Yazd province

    Directory of Open Access Journals (Sweden)

    Taktaz Hafshejani Taghi

    2016-11-01

    Full Text Available Escherichia coli are known as the most common cause of reproductive tract infection in mare. Due to the progressive process of antibiotics use and increasing prevalence of antibiotic resistance, the aim of this study is evaluate the prevalence of subclinical endometritis and antibiotic resistance genes in Escherichia coli isolated. In this study, 60 mares were used with infertility background. Diagnosis of endometritis was performed using history and ultrasonography. Cytology, culture, Antibiogram were done of samples and PCR test was used to examine the gene virulence and antibiotic resistance. E-coli bacteria was isolated 48/33 % from sample culture. In PCR test 66/21 % of bacteria had virulence gene. It was determined, the lowest resistance to chloramphenicol about 38/15% and greatest resistance into ampicillin, tetracycline and streptomycin with 23/69 percent, respectively. 93% samples cytology had neutrophil more than two and the agent of 50% showed E. coli. The cause of half of subclinical endometritis in infertile maresis E-coli bacteriaEscherichia coli are known as the most common cause of reproductive tract infection in mare. Due to the progressive process of antibiotics use and increasing prevalence of antibiotic resistance, the aim of this study is evaluate the prevalence of subclinical endometritis and antibiotic resistance genes in Escherichia coli isolated. In this study, 60 mares were used with infertility background. Diagnosis of endometritis was performed using history and ultrasonography. Cytology, culture, Antibiogram were done of samples and PCR test was used to examine the gene virulence and antibiotic resistance. E-coli bacteria was isolated 48/33 % from sample culture. In PCR test 66/21 % of bacteria had virulence gene. It was determined, the lowest resistance to chloramphenicol about 38/15% and greatest resistance into ampicillin, tetracycline and streptomycin with 23/69 percent, respectively. 93% samples cytology had

  1. Adhesion Studies of Polymers: (I) Autohesion of Ethylene/1-Octene Copolymers; (II) Method Development and Adhesive Characterization of Pressure Sensitive Adhesive in Paper Laminates for Postage Stamps

    OpenAIRE

    Yang, Hailing

    2006-01-01

    Adhesion Studies of Polymers: (I) Autohesion of Ethylene/1-Octene Copolymers; (II) Method Development and Adhesive Characterization of Pressure Sensitive Adhesive in Paper Laminates for Postage Stamps Hailing Yang (Abstract) Autohesion is defined as the resistance to separation of two bonded identical films that have been joined together for a period of time under a given temperature and pressure. Studies on the autohesion phenomenon can provide fundamental insights into the physica...

  2. A study of fish behaviour in the extension of a demersal trawl using a multi-compartment separator frame and SIT camera system

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm; Madsen, Niels; Karlsen, Junita

    2009-01-01

    A rigid separator frame with three vertically stacked codends was used to study fish behaviour in the extension piece of a demersal trawl. A video camera recorded fish as they encountered the separator frame. Ten hauls were conducted in a mixed species fishery in the northern North Sea. Fish...... fish behaviour within the trawl, and together the two methods provided a more complete picture of the catching process. Behavioural observations, vertical distribution, and the methodology are discussed, as is the potential for improving species separation in demersal trawls....... behaviour was analysed using the camera observations from several of these hauls by assigning seven descriptive attributes and also using catch data. Gadoids, in particular haddock (Melanogrammus aeglefinus), whiting (Merlangius merlangus), and saithe (Pollachius virens), were caught in the upper codend...

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

    Science.gov (United States)

    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.

  4. Onboard Inert Gas Generation System/Onboard Oxygen Gas Generation System (OBIGGS/OBOGS) Study. Part 2; Gas Separation Technology--State of the Art

    Science.gov (United States)

    Reynolds, Thomas L.; Eklund, Thor I.; Haack, Gregory A.

    2001-01-01

    This purpose of this contract study task was to investigate the State of the Art in Gas Separation Technologies utilized for separating air into both nitrogen and oxygen gases for potential applications on commercial aircraft. The intended applications included: nitrogen gas for fuel tank inerting, cargo compartment fire protection, and emergency oxygen for passenger and crew use in the event of loss of cabin pressure. The approach was to investigate three principle methods of gas separation: Hollow Fiber Membrane (HFM), Ceramic Membrane (CM), and liquefaction: Total Atmospheric Liquefaction of Oxygen and Nitrogen (TALON). Additional data on the performance of molecular sieve pressure swing adsorption (PSA) systems was also collected and discussed. Performance comparisons of these technologies are contained in the body of the report.

  5. Dosimetric characterization of two radium sources for retrospective dosimetry studies

    Energy Technology Data Exchange (ETDEWEB)

    Candela-Juan, C., E-mail: ccanjuan@gmail.com [Radiation Oncology Department, La Fe University and Polytechnic Hospital, Valencia 46026, Spain and Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Karlsson, M. [Division of Radiological Sciences, Department of Medical and Health Sciences, Linköping University, Linköping SE 581 85 (Sweden); Lundell, M. [Department of Medical Physics and Oncology, Karolinska University Hospital and Karolinska Institute, Stockholm SE 171 76 (Sweden); Ballester, F. [Department of Atomic, Molecular and Nuclear Physics, University of Valencia, Burjassot 46100 (Spain); Tedgren, Å. Carlsson [Division of Radiological Sciences, Department of Medical and Health Sciences, Linköping University, Linköping SE 581 85, Sweden and Swedish Radiation Safety Authority, Stockholm SE 171 16 (Sweden)

    2015-05-15

    Purpose: During the first part of the 20th century, {sup 226}Ra was the most used radionuclide for brachytherapy. Retrospective accurate dosimetry, coupled with patient follow up, is important for advancing knowledge on long-term radiation effects. The purpose of this work was to dosimetrically characterize two {sup 226}Ra sources, commonly used in Sweden during the first half of the 20th century, for retrospective dose–effect studies. Methods: An 8 mg {sup 226}Ra tube and a 10 mg {sup 226}Ra needle, used at Radiumhemmet (Karolinska University Hospital, Stockholm, Sweden), from 1925 to the 1960s, were modeled in two independent Monte Carlo (MC) radiation transport codes: GEANT4 and MCNP5. Absorbed dose and collision kerma around the two sources were obtained, from which the TG-43 parameters were derived for the secular equilibrium state. Furthermore, results from this dosimetric formalism were compared with results from a MC simulation with a superficial mould constituted by five needles inside a glass casing, placed over a water phantom, trying to mimic a typical clinical setup. Calculated absorbed doses using the TG-43 formalism were also compared with previously reported measurements and calculations based on the Sievert integral. Finally, the dose rate at large distances from a {sup 226}Ra point-like-source placed in the center of 1 m radius water sphere was calculated with GEANT4. Results: TG-43 parameters [including g{sub L}(r), F(r, θ), Λ, and s{sub K}] have been uploaded in spreadsheets as additional material, and the fitting parameters of a mathematical curve that provides the dose rate between 10 and 60 cm from the source have been provided. Results from TG-43 formalism are consistent within the treatment volume with those of a MC simulation of a typical clinical scenario. Comparisons with reported measurements made with thermoluminescent dosimeters show differences up to 13% along the transverse axis of the radium needle. It has been estimated that

  6. Thermodynamic study of phase equilibria in petroleum separation plants; Estudo termodinamico do equilibrio de fases em plantas de separacao de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Ciro Rodolfo Santos; Duarte, Lindemberg de Jesus Nogueira [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Santos, Luiz Carlos Lobato [Universidade Federal da Bahia (UFBA), BA (Brazil)

    2012-07-01

    Through a thermodynamic approach of liquid-vapor separation it is possible to provide for a given load, of known composition and given temperature and pressure conditions, which are the volumes and the compositions of liquid and vapor phases in equilibrium. In this sense, the aim of this work is to analyze the separation conditions of the fluids produced in the well 1-FMO-001-BA, belonging to the Field School Project (ANP / UFBA), through a thermodynamic approach of phase equilibrium. This Well is characterized by being in an advanced stage of exploration with low oil and high gas production. Initially, the overall composition of the gas produced from the 1-FMO-001-BA was quantified by gas chromatography and its composition was similar to a typical natural gas found in the Reconcavo's basin. Then, the equilibrium constants were determined by Wilson empirical correlation, which could enable the determination of the dead oil composition. This oil showed low concentration of light hydrocarbons (e.g., methane, etc.) and moderate concentrations of heavy components (e.g., C{sub 10} {sub +}). Moreover, the original composition of the fluid that reaches the separator vessel had a similar chemical composition to the outlet gaseous stream of the separator vessel, proving that the Fazenda Mamoeiro's reservoir is classified as a gas reservoir. Finally, it was determined the relative density of the gas ({gamma} g = 0.8264), the specific gravity of the dead oil ({gamma} {sub o} = 0.7542), the API gravity (56.13) and gas-oil ratio (GOR 950.98 m{sup 3}std / m{sup 3}std), which are consistent with the data provided by PETROBRAS. (author)

  7. Separate and combined associations of body-mass index and abdominal adiposity with cardiovascular disease: collaborative analysis of 58 prospective studies

    DEFF Research Database (Denmark)

    Wormser, David; Kaptoge, Stephen; Di Angelantonio, Emanuele

    2011-01-01

    Guidelines differ about the value of assessment of adiposity measures for cardiovascular disease risk prediction when information is available for other risk factors. We studied the separate and combined associations of body-mass index (BMI), waist circumference, and waist-to-hip ratio with risk...

  8. Functional, motor developmental, and long-term outcome after the component separation technique in children with giant omphalocele: A case control study

    NARCIS (Netherlands)

    Eijck, F.C. van; Vlimmeren, L.A. van; Wijnen, R.M.H.; Klein, W.; Kruijen, I.; Pillen, S.; Nijhuis-Van der Sanden, M.W.G.

    2013-01-01

    BACKGROUND/PURPOSE: The objective of this study was to evaluate the long-term functional and motor development and abdominal muscle quantity in children operated on for giant omphalocele (GOC) with the Component Separation Technique (CST). METHODS: Between 2004 and 2007, CST was applied in eleven

  9. An application of the theory of planned behaviour to study the influencing factors of participation in source separation of food waste

    Energy Technology Data Exchange (ETDEWEB)

    Karim Ghani, Wan Azlina Wan Ab., E-mail: wanaz@eng.upm.edu.my [Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan (Malaysia); Rusli, Iffah Farizan, E-mail: iffahrusli@yahoo.com [Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan (Malaysia); Biak, Dayang Radiah Awang, E-mail: dayang@eng.upm.edu.my [Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan (Malaysia); Idris, Azni, E-mail: azni@eng.upm.edu.my [Department of Chemical and Environmental Engineering, Faculty of Engineering, University Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan (Malaysia)

    2013-05-15

    collection times are also encouraged public’s involvement and consequently, the participations rate. The findings from this study may provide useful indicator to the waste management authorities in Malaysia in identifying mechanisms for future development and implementation of food waste source separation activities in household programmes and communication campaign which advocate the use of these programmes.

  10. Separation and characterization of polyphenolics from underutilized byproducts of fruit production (Choerospondias axillaris peels): inhibitory activity of proanthocyanidins against glycolysis enzymes.

    Science.gov (United States)

    Li, Qian; Chen, Jun; Li, Ti; Liu, Chengmei; Zhai, Yuxin; McClements, David Julian; Liu, Jiyan

    2015-12-01

    Bioactive proanthocyanidins were isolated from the peel of Choerospondias axillaris fruit, which is a waste product of the food processing industry. Compositional analysis indicated that the proanthocyanidins had extension units mainly consisting of epicatechin gallate or epicatechin, and terminal units mainly consisting of catechin. Numerous polymeric forms of the molecules were detected, including monomers, dimers, and trimers. Certain fractions exhibited strong α-amylase or α-glucosidase inhibition in a dose-dependent manner. Furthermore, their inhibitory activities depended on their degree of polymerization and galloylation. For example, the most bioactive fraction had α-amylase and α-glucosidase inhibitory activities (IC50 values) of 541 and 3.1 μg mL(-1), respectively. This study demonstrates that proanthocyanidins from C. axillaris peels can inhibit carbohydrate digestive enzymes in vitro and may therefore serve as antidiabetic ingredients in functional or medical foods.

  11. Synthesis and characterization of silicon carbonitride films by plasma enhanced chemical vapor deposition (PECVD) using bis(dimethylamino)dimethylsilane (BDMADMS), as membrane for a small molecule gas separation

    Science.gov (United States)

    Kafrouni, W.; Rouessac, V.; Julbe, A.; Durand, J.

    2010-12-01

    Silicon carbonitride thin films have been deposited by plasma enhanced chemical vapor deposition (PECVD) from bis(dimethylamino)dimethylsilane (BDMADMS) as a function of X = (BDMADMS/(BDMADMS + NH 3)) between 0.1 and 1, and plasma power P (W) between 100 and 400 W. The microstructure of obtained materials has been studied by SEM, FTIR, EDS, ellipsometrie, and contact angle of water measurements. The structure of the materials is strongly depended on plasma parameters; we can pass from a material rich in carbon to a material rich in nitrogen. Single gas permeation tests have been carried out and we have obtained a helium permeance of about 10 -7 mol m -2 s -1 Pa -1 and ideal selectivity of helium over nitrogen of about 20.

  12. Parental separation and pediatric cancer

    DEFF Research Database (Denmark)

    Grant, Sally; Carlsen, Kathrine; Bidstrup, Pernille Envold Hansen

    2012-01-01

    The purpose of this study was to determine the risk for separation (ending cohabitation) of the parents of a child with a diagnosis of cancer.......The purpose of this study was to determine the risk for separation (ending cohabitation) of the parents of a child with a diagnosis of cancer....

  13. Effect of trailing edge shape on the separated flow characteristics around an airfoil at low Reynolds number: A numerical study

    Science.gov (United States)

    Thomareis, Nikitas; Papadakis, George

    2017-01-01

    Direct numerical simulations of the flow field around a NACA 0012 airfoil at Reynolds number 50 000 and angle of attack 5° with 3 different trailing edge shapes (straight, blunt, and serrated) have been performed. Both time-averaged flow characteristics and the most dominant flow structures and their frequencies are investigated using the dynamic mode decomposition method. It is shown that for the straight trailing edge airfoil, this method can capture the fundamental as well as the subharmonic of the Kelvin-Helmholtz instability that develops naturally in the separating shear layer. The fundamental frequency matches well with relevant data in the literature. The blunt trailing edge results in periodic vortex shedding, with frequency close to the subharmonic of the natural shear layer frequency. The shedding, resulting from a global instability, has an upstream effect and forces the separating shear layer. Due to forcing, the shear layer frequency locks onto the shedding frequency while the natural frequency (and its subharmonic) is suppressed. The presence of serrations in the trailing edge creates a spanwise pressure gradient, which is responsible for the development of a secondary flow pattern in the spanwise direction. This pattern affects the mean flow in the near wake. It can explain an unexpected observation, namely, that the velocity deficit downstream of a trough is smaller than the deficit after a protrusion. Furthermore, the insertion of serrations attenuates the energy of vortex shedding by de-correlating the spanwise coherence of the vortices. This results in weaker forcing of the separating shear layer, and both the subharmonics of the natural frequency and the shedding frequency appear in the spectra.

  14. Quest for Environmentally-Benign Ligands for Actinide Separations: Thermodynamic, Spectroscopic, and Structural Characterization of U(VI) Complexes with Oxa-Diamide and Related Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Advanced Light Source; Tian, Guoxin; Rao, Linfeng; Teat, Simon J.; Liu, Guokui

    2009-01-05

    Complexation of U(VI) with N,N,N{prime},N{prime}-tetramethyl-3-oxa-glutaramide (TMOGA) and N,N-dimethyl-3-oxa-glutaramic acid (DMOGA) was studied in comparison with their dicarboxylate analog, oxydiacetic acid (ODA). Thermodynamic parameters, including stability constants, enthalpy and entropy of complexation, were determined by spectrophotometry, potentiometry and calorimetry. Single-crystal X-ray diffractometry, EXAFS spectroscopy, FT-IR absorption and laser-induced luminescence spectroscopy were used to obtain structural information on the U(VI) complexes. Like ODA, TMOGA and DMOGA form tridentate U(VI) complexes, with three oxygen atoms (the amide, ether and/or carboxylate oxygen) coordinating to the linear UO{sub 2}{sup 2+} cation via the equatorial plane. The stability constants, enthalpy and entropy of complexation all decrease in the order ODA > DMOGA > TMOGA, showing that the complexation is entropy driven and the substitution of a carboxylate group with an amide group reduces the strength of complexation with U(VI) due to the decrease in the entropy of complexation. The trend in the thermodynamic stability of the complexes correlates very well with the structural and spectroscopic data obtained by single crystal XRD, FT-IR and laser-induced luminescence spectroscopy.

  15. Bifunctional cyclam-based ligands with phosphorus acid pendant moieties for radiocopper separation: thermodynamic and kinetic studies.

    Science.gov (United States)

    Paúrová, Monika; Havlíčková, Jana; Pospíšilová, Aneta; Vetrík, Miroslav; Císařová, Ivana; Stephan, Holger; Pietzsch, Hans-Jürgen; Hrubý, Martin; Hermann, Petr; Kotek, Jan

    2015-03-16

    Two macrocyclic ligands based on cyclam with trans-disposed N-methyl and N-(4-aminobenzyl) substituents as well as two methylphosphinic (H2L1) or methylphosphonic (H4L2) acid pendant arms were synthesised and investigated in solution. The ligands form stable complexes with transition metal ions. Both ligands show high thermodynamic selectivity for divalent copper over nickel(II) and zinc(II)-K(CuL) is larger than K(Ni/ZnL) by about seven orders of magnitude. Complexation is significantly faster for the phosphonate ligand H4L2, probably due to the stronger coordination ability of the more basic phosphonate groups, which efficiently bind the metal ion in an "out-of-cage" complex and thus accelerate its "in-cage" binding. The rate of Cu(II) complexation by the phosphinate ligand H2L1 is comparable to that of cyclam itself and its derivatives with non-coordinating substituents. Acid-assisted decomplexation of the copper(II) complexes is relatively fast (τ1/2 = 44 and 42 s in 1 M aq. HClO4 at 25 °C for H2L1 and H4L2, respectively). This combination of properties is convenient for selective copper removal/purification. Thus, the title ligands were employed in the preparation of ion-selective resins for radiocopper(II) separation. Glycidyl methacrylate copolymer beads were modified with the ligands through a diazotisation reaction. The separation ability of the modified polymers was tested with cold copper(II) and non-carrier-added (64)Cu in the presence of a large excess of both nickel(II) and zinc(II). The experiments exhibited high overall separation efficiency leading to 60-70% recovery of radiocopper with high selectivity over the other metal ions, which were originally present in 900-fold molar excess. The results showed that chelating resins with properly tuned selectivity of their complexing moieties can be employed for radiocopper separation. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. A Study of Flow Separation in Transonic Flow Using Inviscid and Viscous Computational Fluid Dynamics (CFD) Schemes

    Science.gov (United States)

    Rhodes, J. A.; Tiwari, S. N.; Vonlavante, E.

    1988-01-01

    A comparison of flow separation in transonic flows is made using various computational schemes which solve the Euler and the Navier-Stokes equations of fluid mechanics. The flows examined are computed using several simple two-dimensional configurations including a backward facing step and a bump in a channel. Comparison of the results obtained using shock fitting and flux vector splitting methods are presented and the results obtained using the Euler codes are compared to results on the same configurations using a code which solves the Navier-Stokes equations.

  17. Hereditary separability in Hausdorff continua

    Directory of Open Access Journals (Sweden)

    D. Daniel

    2012-04-01

    Full Text Available We consider those Hausdorff continua S such that each separable subspace of S is hereditarily separable. Due to results of Ostaszewski and Rudin, respectively, all monotonically normal spaces and therefore all continuous Hausdorff images of ordered compacta also have this property. Our study focuses on the structure of such spaces that also possess one of various rim properties, with emphasis given to rim-separability. In so doing we obtain analogues of results of M. Tuncali and I. Loncar, respectively.

  18. Fictional Separation Logic

    DEFF Research Database (Denmark)

    Jensen, Jonas Buhrkal; Birkedal, Lars

    2012-01-01

    , separation means physical separation. In this paper, we introduce \\emph{fictional separation logic}, which includes more general forms of fictional separating conjunctions P * Q, where "*" does not require physical separation, but may also be used in situations where the memory resources described by P and Q...... overlap. We demonstrate, via a range of examples, how fictional separation logic can be used to reason locally and modularly about mutable abstract data types, possibly implemented using sophisticated sharing. Fictional separation logic is defined on top of standard separation logic, and both the meta...

  19. Separating biological cells

    Science.gov (United States)

    Brooks, D. E.

    1979-01-01

    Technique utilizing electric field to promote biological cell separation from suspending medium in zero gravity increases speed, reduces sedimentation, and improves efficiency of separation in normal gravity.

  20. Characterizing longitudinal patterns of physical activity in mid-adulthood using latent class analysis: results from a prospective cohort study.

    Science.gov (United States)

    Silverwood, Richard J; Nitsch, Dorothea; Pierce, Mary; Kuh, Diana; Mishra, Gita D

    2011-12-15

    The authors aimed to describe how longitudinal patterns of physical activity during mid-adulthood (ages 31-53 years) can be characterized using latent class analysis in a population-based birth cohort study, the Medical Research Council's 1946 National Survey of Health and Development. Three different types of physical activity-walking, cycling, and leisure-time physical activity-were analyzed separately using self-reported data collected from questionnaires between 1977 and 1999; 3,847 study members were included in the analysis for one or more types of activity. Patterns of activity differed by sex, so stratified analyses were conducted. Two walking latent classes were identified representing low (52.8% of males in the cohort, 33.5% of females) and high (47.2%, 66.5%) levels of activity. Similar low (91.4%, 82.1%) and high (8.6%, 17.9%) classes were found for cycling, while 3 classes were identified for leisure-time physical activity: "low activity" (46.2%, 48.2%), "sports and leisure activity" (31.0%, 35.3%), and "gardening and do-it-yourself activities" (22.8%, 16.5%). The classes were reasonably or very well separated, with the exception of walking in females. Latent class analysis was found to be a useful tool for characterizing longitudinal patterns of physical activity, even when the measurement instrument differs slightly across ages, which added value in comparison with observed activity at a single age.

  1. Synthesis, characterization, electrical and catalytic studies of some ...

    African Journals Online (AJOL)

    hydroxyacetophenone, 2-hydroxy-5-methyl-3-nitro acetophenone and carbohydrazide and its complexes with VO(IV), Cr(III), Mn(III), Fe(III), MoO2(VI), WO2(VI), Zr(IV) and UO2(VI) have been prepared. They were characterized by elemental analysis, ...

  2. Defining and Characterizing Ecosystem Services for Education: A Delphi Study

    Science.gov (United States)

    Ruppert, John; Duncan, Ravit Golan

    2017-01-01

    Recent advancements in science have led to an increasingly sophisticated understanding of the many ways in which humans benefit from environmental systems. These benefits, termed Ecosystem Services, are sparsely characterized in education literature, but were included in the most recent iteration of US national science standards: the Next…

  3. Ion-optical studies of BigRIPS separator and ZeroDegree spectrometer at RIKEN RI Beam Factory

    Science.gov (United States)

    Takeda, Hiroyuki; Kubo, Toshiyuki; Ohnishi, Tetsuya; Fukuda, Naoki; Kameda, Daisuke; Kusaka, Kensuke; Yoshida, Atsushi; Yoshida, Koichi; Ohtake, Masao; Inabe, Naohito; Yanagisawa, Yoshiyuki; Tanaka, Kanenobu; Matsushita, Masafumi

    2009-10-01

    The BigRIPS in-flight separator[1] and the ZeroDegree spectrometer (ZDS) have been commissioned at RIKEN RI Beam Factory (RIBF) recently. Intense radioactive isotope (RI) beams are produced, separated and analyzed by the BigRIPS and the ZDS. Both of them are operated in several optical modes according to experimental conditions. For particle identifications of RI beams, it is essentially important to achieve high resolutions in A/Q ratio because RI beams are produced in several charge states in our energy region especially for heavy RI beams. Ion optical calculation with realistic magnetic field maps is indispensable for our purpose and we use COSY INFINITY[2] for that. Measured field maps are incorporated in the COSY calculations. In 2008, the ZDS was commissioned for the first time in three different modes. Experimental results and comparison with the COSY calculations will be presented in this report. [1]T. Kubo: Nucl. Instr. Meth. B204, 97 (2003). [2]K. Makino, M. Berz: Nucl. Instr. Meth. A558, 346 (2006).

  4. Chromatographic Separations of Enantiomers and Underivatized Oligosaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    My graduate research has focused on separation science and bioanalytical analysis, which emphasized in method development. It includes three major areas: enantiomeric separations using high performance liquid chromatography (HPLC), Super/subcritical fluid chromatography (SFC), and capillary electrophoresis (CE); drug-protein binding behavior studies using CE; and carbohydrate analysis using liquid chromatograph-electrospray ionization mass spectrometry (LC-ESI-MS). Enantiomeric separations continue to be extremely important in the pharmaceutical industry. An in-depth evaluation of the enantiomeric separation capabilities of macrocyclic glycopeptides CSPs with SFC mobile phases was investigated using a set of over 100 chiral compounds. It was found that the macrocyclic based CSPs were able to separate enantiomers of various compounds with different polarities and functionalities. Seventy percent of all separations were achieved in less than 4 min due to the high flow rate (4.0 ml/min) that can be used in SFC. Drug-protein binding is an important process in determining the activity and fate of a drug once it enters the body. Two drug/protein systems have been studied using frontal analysis CE method. More sensitive fluorescence detection was introduced in this assay, which overcame the problem of low sensitivity that is common when using UV detection for drug-protein studies. In addition, the first usage of an argon ion laser with 257 nm beam coupled with CCD camera as a frontal analysis detection method enabled the simultaneous observation of drug fluorescence as well as the protein fluorescence. LC-ESI-MS was used for the separation and characterization of underivatized oligosaccharide mixtures. With the limits of detection as low as 50 picograms, all individual components of oligosaccharide mixtures (up to 11 glucose-units long) were baseline resolved on a Cyclobond I 2000 column and detected using ESI-MS. This system is characterized by high chromatographic

  5. Separable programming theory and methods

    CERN Document Server

    Stefanov, Stefan M

    2001-01-01

    In this book, the author considers separable programming and, in particular, one of its important cases - convex separable programming Some general results are presented, techniques of approximating the separable problem by linear programming and dynamic programming are considered Convex separable programs subject to inequality equality constraint(s) and bounds on variables are also studied and iterative algorithms of polynomial complexity are proposed As an application, these algorithms are used in the implementation of stochastic quasigradient methods to some separable stochastic programs Numerical approximation with respect to I1 and I4 norms, as a convex separable nonsmooth unconstrained minimization problem, is considered as well Audience Advanced undergraduate and graduate students, mathematical programming operations research specialists

  6. Investigational study of the CO2 balance in high temperature CO2 separation technology; Nisanka tanso koon bunri gijutsu ni okeru CO2 balance ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    An investigational study was conducted to clarify the adaptable environment and effectivity of technologies of high temperature separation/recovery/reutilization of CO2. In the study, data collection, arrangement and comparison were made of various separation technologies such as the membrane method, absorption method, adsorption method, and cryogenic separation method. With the LNG-fired power generation as an example, the adaptable environment and effectivity were made clear by making models by a process simulator, ASPEN PLUS. Moreover, using this simulator, effects of replacing the conventional steam reforming of hydrocarbon with the CO2 reforming were made clear with the methanol synthesis as an example. As to the rock fixation treatment of high temperature CO2, collection/arrangement were made of the data on the fixation treatment of the CO2 separated at high temperature into basic rocks such as peridotite and serpentinite in order to clarify the adaptable environment and effectivity of the treatment. Besides, a potentiality of the fixation to concrete waste was made clear. 57 refs., 57 figs., 93 tabs.

  7. The effects of marriage and separation on the psychotropic medication use of non-married cohabiters: a register-based longitudinal study among adult Finns.

    Science.gov (United States)

    Metsä-Simola, Niina; Martikainen, Pekka

    2014-11-01

    Non-marital cohabitation has become increasingly common and is suggested to offer similar mental-health benefits as marriage does. We studied levels and changes in cohabiters' mental health five years before and five years after entering into marriage or separating, and compared long-term non-married and married cohabiters. We analysed changes in the three-month prevalence of psychotropic medication use (psycholeptics and psychoanaleptics, excluding medication for dementia) by proximity to non-marital transition and gender, using register data on 189,394 Finns aged 25 to 64. Similar levels of psychotropic-medication use were found among individuals in long unions that continued throughout the follow-up and were non-marital, marital, or changed from non-marital to marital. Among men and women who separated from longer cohabiting unions of more than five years, however, an increase in medication prevalence was observed immediately before separation, followed by a similar decline after separation. At the time of separation the level of medication use was 9.9 per cent (95% CI = 8.7 - 11.3) among men and 15.7 per cent (95% CI = 14.2 - 17.4) among women compared to 4.3 per cent (95% CI = 3.7 - 5.0) and 8.0 per cent (95% CI = 7.2 - 9.0), respectively, among those who cohabited continuously. No changes in medication use were observed before or after separation among those leaving shorter cohabiting unions of less than five years. Among those marrying following shorter cohabiting unions a positive effect of approaching marriage was observed only among women. Compared to continuous cohabiters, the level of medication use was higher among men and women separating from both short-term and long-term cohabiting unions five years before separation. This selective effect suggests that cohabiters with mental-health problems might benefit from relationship counselling. In a long-term stable union it seems to matter little for mental health whether the union is marital or non

  8. Nanomaterial synthesis and characterization for toxicological studies: TiO2 case study

    Science.gov (United States)

    Valsami-Jones, E.; Berhanu, D.; Dybowska, A.; Misra, S.; Boccaccini, A.R.; Tetley, T.D.; Luoma, S.N.; Plant, J.A.

    2008-01-01

    In recent years it has become apparent that the novel properties of nanomaterials may predispose them to a hitherto unknown potential for toxicity. A number of recent toxicological studies of nanomaterials exist, but these appear to be fragmented and often contradictory. Such discrepancies may be, at least in part, due to poor description of the nanomaterial or incomplete characterization, including failure to recognise impurities, surface modifications or other important physicochemical aspects of the nanomaterial. Here we make a case for the importance of good quality, well-characterized nanomaterials for future toxicological studies, combined with reliable synthesis protocols, and we present our efforts to generate such materials. The model system for which we present results is TiO2 nanoparticles, currently used in a variety of commercial products. ?? 2008 The Mineralogical Society.

  9. Urea nitrate, an exceptionally easy-to-make improvised explosive: studies towards trace characterization.

    Science.gov (United States)

    Tamiri, Tsippy; Rozin, Rinat; Lemberger, Nitay; Almog, Joseph

    2009-09-01

    Urea nitrate is a powerful improvised explosive, frequently used by terrorists in the Israeli arena. It was also used in the first World Trade Center bombing in New York in February 1993. It is difficult to identify urea nitrate in post-explosion debris, since only a very small fraction survives the blast. Also, in the presence of water, it readily decomposes to its original components, urea and nitric acid. It is suspected that post-blast debris of urea nitrate can be confused with ammonium nitrate, the main solid product of urea nitrate thermal decomposition. In a comprehensive study towards identification of urea nitrate in post-blast traces, a spectrophotometric technique for quantitative determination of urea nitrate was developed, and conditions were found for extraction and separation of un-exploded traces of urea nitrate with minimal decomposition. Nevertheless, out of 28 samples collected from a series of three controlled firings of urea nitrate charges, only one gave the typical adduct ion by liquid chromatography/mass spectrometry analysis. We found that urea nitrate can be extracted from solid mixtures to organic solvents by using Crown ethers as "host compounds." The adducts thus formed are solid, crystalline compounds that can be characterized by microanalysis and spectroscopic techniques.

  10. Full Waveform Inversion for Reservoir Characterization - A Synthetic Study

    KAUST Repository

    Zabihi Naeini, E.

    2017-05-26

    Most current reservoir-characterization workflows are based on classic amplitude-variation-with-offset (AVO) inversion techniques. Although these methods have generally served us well over the years, here we examine full-waveform inversion (FWI) as an alternative tool for higher-resolution reservoir characterization. An important step in developing reservoir-oriented FWI is the implementation of facies-based rock physics constraints adapted from the classic methods. We show that such constraints can be incorporated into FWI by adding appropriately designed regularization terms to the objective function. The advantages of the proposed algorithm are demonstrated on both isotropic and VTI (transversely isotropic with a vertical symmetry axis) models with pronounced lateral and vertical heterogeneity. The inversion results are explained using the theoretical radiation patterns produced by perturbations in the medium parameters.

  11. Decay Study for the very Neutron-Rich Sn Nuclides, $^{135-140}$Sn Separated by Selective Laser Ionization

    CERN Multimedia

    2002-01-01

    %IS378 %title\\\\ \\\\ In this investigation, we wish to take advantage of chemically selective laser ionization to separate the very-neutron-rich Sn nuclides and determine their half-lives and delayed-neutron branches (P$_{n}$) using the Mainz $^{3}$He-delayed neutron spectrometer and close-geometry $\\gamma$-ray spectroscopy system. The $\\beta$-decay rates are dependent on a number of nuclear structure factors that may not be well described by models of nuclear structure developed for nuclides near stability. Determination of these decay properties will provide direct experimental data for r-process calculations and test the large number of models of nuclear structure for very-neutron rich Sn nuclides now in print.

  12. Comparative study of original recover and recover KL in separable non-negative matrix factorization for topic detection in Twitter

    Science.gov (United States)

    Prabandari, R. D.; Murfi, H.

    2017-07-01

    An increasing amount of information on social media such as Twitter requires an efficient way to find the topics so that the information can be well managed. One of an automated method for topic detection is separable non-negative matrix factorization (SNMF). SNMF assumes that each topic has at least one word that does not appear on other topics. This method uses the direct approach and gives polynomial-time complexity, while the previous methods are iterative approaches and have NP-hard complexity. There are three steps of SNMF algorithm, i.e. constructing word co-occurrences, finding anchor words, and recovering topics. In this paper, we examine two topic recover methods, namely original recover that is using algebraic manipulation and recover KL that using probability approach with Kullback-Leibler divergence. Our simulations show that recover KL provides better accuracies in term of topic recall than original recover.

  13. Synthesis, Characterization and Biological Activity Studies of Mixed ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: Mixed ligand-metal complexes of Paracetamol and Ascorbic acid were synthesized using FeCl2.4H2O,. CuCl2.2H2O, NiCl2.6H2O, CoCl2.6H2O and ZnSO4 salts based on two concentrations (3mmol and 5mmol). The complexes were characterized using some physical techniques such as melting point, ...

  14. Study of the C{sub 10}-C{sub 14} paraffins separation by adsorption on 5A zeolite; Etude de la separation des paraffines en C{sub 10}-C{sub 14} par adsorption sur zeolithe 5A

    Energy Technology Data Exchange (ETDEWEB)

    Paoli, H.

    2002-11-01

    Surface-active synthesis by the way of LAB (Linear Alkyl Benzene) chain needs linear alkanes between C10 and C14. The petroleum cut used is a mixture of linear and branched paraffins, and therefore a separation is needed. It is realised using of a Simulated Counter Current process, developed and licensed by IFP. The molecular sieve employed, i.e. zeolite 5A, is obtained by ion exchange and thermal treatment from a 4A zeolite. These post synthesis operations modify the adsorbent structure and consequently its adsorption and diffusion properties. After having obtained a range as complete as possible of samples of various exchange ratios and treated in various conditions, we have characterised these adsorbent structures by X-Rays Diffraction. A limited number of structures has been refined by the Rietveld method, on the basis of anomalous diffraction experiments at the Ca K edge. Aluminium NMR was used as well. These structural data allowed to explain adsorption properties modifications of various probe molecules (H{sub 2}O, nC{sub 6}, nC{sub 10} and nC{sub 14}) studied by TPD and diffusion properties modifications studied by Quasi Elastic Neutron Scattering. (author)

  15. Controlling Separation in Turbomachines

    Science.gov (United States)

    Evans, Simon; Himmel, Christoph; Power, Bronwyn; Wakelam, Christian; Xu, Liping; Hynes, Tom; Hodson, Howard

    2010-01-01

    Four examples of flow control: 1) Passive control of LP turbine blades (Laminar separation control). 2) Aspiration of a conventional axial compressor blade (Turbulent separation control). 3) Compressor blade designed for aspiration (Turbulent separation control). 4.Control of intakes in crosswinds (Turbulent separation control).

  16. Study of borehole probing methods to improve the ground characterization

    Science.gov (United States)

    Naeimipour, Ali

    Collecting geological information allows for optimizing ground control measures in underground structures. This includes understanding of the joints and discontinuities and rock strength to develop rock mass classifications. An ideal approach to collect such information is through correlating the drilling data from the roofbolters to assess rock strength and void location and properties. The current instrumented roofbolters are capable of providing some information on these properties but not fully developed for accurate ground characterization. To enhance existing systems additional instrumentation and testing was conducted in laboratory and field conditions. However, to define the geology along the boreholes, the use of probing was deemed to be most efficient approach for locating joints and structures in the ground and evaluation of rock strength. Therefore, this research focuses on selection and evaluation of proper borehole probes that can offer a reliable assessment of rock mass structure and rock strength. In particular, attention was paid to borehole televiewer to characterize rock mass structures and joints and development of mechanical rock scratcher for determination of rock strength. Rock bolt boreholes are commonly drilled in the ribs and the roof of underground environments. They are often small (about 1.5 inches) and short (mostly 2-3 meter). Most of them are oriented upward and thus, mostly dry or perhaps wet but not filled with water. No suitable system is available for probing in such conditions to identify the voids/joints and specifically to measure rock strength for evaluation of rock mass and related optimization of ground support design. A preliminary scan of available borehole probes proved that the best options for evaluation of rock structure is through analysis of borehole images, captured by optical televiewers. Laboratory and field trials with showed that these systems can be used to facilitate measurement of the location, frequency and

  17. Study on the effect of periodic wake on a separation flow. On the changes of the fluctuation frequency of separation flow; Shukiteki koryu ga hakuri nagare ni ataeru eikyo. Hakuri nagare no shuhasu no henka

    Energy Technology Data Exchange (ETDEWEB)

    Yamagishi, M.; Tashiro, S. [Tokyo Metropolitan Institute of Technology, Tokyo (Japan)

    2000-04-25

    The vortex structure within a separated flow region changes when the disturbance is introduced in a mean-flow. This change was investigated by numerical simulation. The periodic velocity fluctuation introduced into the mean-flow at the upstream of separation shear layer, and its amplitude is 30% of the mean-flow velocity. By this periodic fluctuation, the shear layer is flapped to make vortices be shed with the frequency of fluctuation. For making the separation region narrow, it is found that the most effective frequency is about twice of the frequency which is dominant in the separation flow without fluctuation. Furthermore, first sub and super harmonics of that frequency make the flow be periodic. These resonance are explained by using the wave number which is equivalent to the vortex scale. (author)

  18. An application of the theory of planned behaviour to study the influencing factors of participation in source separation of food waste.

    Science.gov (United States)

    Karim Ghani, Wan Azlina Wan Ab; Rusli, Iffah Farizan; Biak, Dayang Radiah Awang; Idris, Azni

    2013-05-01

    Tremendous increases in biodegradable (food waste) generation significantly impact the local authorities, who are responsible to manage, treat and dispose of this waste. The process of separation of food waste at its generation source is identified as effective means in reducing the amount food waste sent to landfill and can be reused as feedstock to downstream treatment processes namely composting or anaerobic digestion. However, these efforts will only succeed with positive attitudes and highly participations rate by the public towards the scheme. Thus, the social survey (using questionnaires) to analyse public's view and influencing factors towards participation in source separation of food waste in households based on the theory of planned behaviour technique (TPB) was performed in June and July 2011 among selected staff in Universiti Putra Malaysia, Serdang, Selangor. The survey demonstrates that the public has positive intention in participating provided the opportunities, facilities and knowledge on waste separation at source are adequately prepared by the respective local authorities. Furthermore, good moral values and situational factors such as storage convenience and collection times are also encouraged public's involvement and consequently, the participations rate. The findings from this study may provide useful indicator to the waste management authorities in Malaysia in identifying mechanisms for future development and implementation of food waste source separation activities in household programmes and communication campaign which advocate the use of these programmes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Effective ligand functionalization of zirconium-based metal-organic frameworks for the adsorption and separation of benzene and toluene: a multiscale computational study.

    Science.gov (United States)

    Wu, Ying; Chen, Huiyong; Liu, Defei; Xiao, Jing; Qian, Yu; Xi, Hongxia

    2015-03-18

    The adsorption and separation properties of benzene and toluene on the zirconium-based frameworks UiO-66, -67, -68, and their functional analogues UiO-Phe and UiO-Me2 were studied using grand canonical Monte Carlo simulations, density functional theory, and ideal adsorbed solution theory. Remarkable higher adsorption uptakes of benzene and toluene at low pressures on UiO-Phe and -Me2 were found compared to their parent framework UiO-67. It can be ascribed to the presence of functional groups (aromatic rings and methyl groups) that significantly intensified the adsorption, majorly by reducing the effective pore size and increasing the interaction strength with the adsorbates. At high pressures, the pore volumes and accessible surfaces of the frameworks turned out to be the dominant factors governing the adsorption. In the case of toluene/benzene separation, toluene selectivities of UiOs showed a two-stage separation behavior at the measured pressure range, resulting from the greater interaction affinities of toluene at low pressures and steric hindrance effects at high pressures. Additionally, the counterbalancing factors of enhanced π delocalization and suitable pore size of UiO-Phe gave rise to the highest toluene selectivity, suggesting the ligand functionalization strategy could reach both high adsorption capacity and separation selectivity from aromatic mixtures at low concentrations.

  20. Colour Separation and Aversion

    Directory of Open Access Journals (Sweden)

    Sarah M Haigh

    2012-05-01

    Full Text Available Aversion to achromatic patterns is well documented but relatively little is known about discomfort from chromatic patterns. Large colour differences are uncommon in the natural environment and deviation from natural statistics makes images uncomfortable (Fernandez and Wilkins 2008, Perception, 37(7, 1098–113; Juricevic et al 2010, Perception, 39(7, 884–899. We report twelve studies documenting a linear increase in aversion to chromatic square-wave gratings as a function of the separation in UCS chromaticity between the component bars, independent of their luminance contrast. Two possible explanations for the aversion were investigated: (1 accommodative response, or (2 cortical metabolic demand. We found no correlation between chromaticity separation and accommodative lag or variance in lag, measured using an open-field autorefractor. However, near infrared spectroscopy of the occipital cortex revealed a larger oxyhaemoglobin response to patterns with large chromaticity separation. The aversion may be cortical in origin and does not appear to be due to accommodation.

  1. Geotechnical characterization of the North Ramp of the Exploratory Studies Facility: Yucca Mountain Site Characterization Project. Volume 1, Data summary

    Energy Technology Data Exchange (ETDEWEB)

    Brechtel, C.E.; Lin, Ming; Martin, E. [Agapito Associates, Inc., Grand Junction, CO (United States); Kessel, D.S. [Sandia National Labs., Albuquerque, NM (United States)

    1995-05-01

    This report presents the results of geological and geotechnical characterization of the Miocene volcanic tuff rocks of the Timber Mountain and Paintbrush groups that the tunnel boring machine will encounter during excavation of the Exploratory Studies Facility (ESF) North Ramp. The is being constructed by the DOE as part of the Yucca Mountain Project site characterization activities. The purpose of these activities is to evaluate the feasibility of locating a potential high-level nuclear waste repository on lands adjacent to the Nevada Test Site, Nye County, Nevada. This report was prepared as part of the Soil and Rock Properties Studies in accordance with the 8.3.1.14.2 Study Plan. This report is volume 1 of the data summary.

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

    Science.gov (United States)

    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

  3. Peptidomics for dairy foods characterization - a method development study

    DEFF Research Database (Denmark)

    Villumsen, Nanna Stengaard; Hammershøj, Marianne; Sørensen, John

    During storage of long shelf life dairy products undesired changes can appear in the products. One major change in liquid UHT products and re-dissolved dairy product powders is an increase in viscosity, creation of “fluffy” material or “clouds” caused by aggregation of material including proteins...... of proteins and/or proteolysis from heat stable proteases – either native bovine proteases or from psychrotropic bacteria in the raw milk, or in combination. The project therefore aims at analyzing and outlining the formation of aggregates by proteomic characterizations combined with peptidomic profiles...

  4. Revisiting separation properties of convex fuzzy sets

    Science.gov (United States)

    Separation of convex sets by hyperplanes has been extensively studied on crisp sets. In a seminal paper separability and convexity are investigated, however there is a flaw on the definition of degree of separation. We revisited separation on convex fuzzy sets that have level-wise (crisp) disjointne...

  5. Experimental study of a separated jets burner: application to the natural gas-pure oxygen combustion; Etude experimentale du comportement de bruleurs a jets separes: application a la combustion gaz naturel-oxygene pur

    Energy Technology Data Exchange (ETDEWEB)

    Salentey, L.

    2002-04-15

    The evolution of pollution standards and the optimisation of furnaces performances require a development of new burner generation and also the improvement of combustion techniques. Actually, the use of oxy-combustion in separated jets burners offers interesting prospects for NO{sub x} emission reduction and on the modularity of flames properties (lift off, flame front topology, flame length). The complex geometry of those burners leads to several problems like the three-dimensional character of the flow, which may sometimes disturb the flame stability as flames are lifted above the burner. This experimental study deals with a simplified version of that kind of burner constituted with a central natural gas jet surrounded by two oxygen jets. Primary, the study of non-reactive jet was planned in order to understand dynamic and mixture phenomena involved between jets and to provide a database useful for the computer code validation. The reactive flow developed in a furnace, which simulates the real conditions, had been characterised. The studies of the dynamic field using Laser Doppler Velocimetry (LDV) and of the turbulent mixture by conditional Laser tomography were supplemented in combustion by the visualisation of the spontaneous emission of radical OH, in the initial and final zone of the oxy-flames, like by the measurement of pollutants like NO{sub x} and soot. The measurements carried out while varying speeds of injection as well as the gap between the jets made possible the highlight of the influence of these parameters upon the stabilisation of the oxy-flames as well as the modification of the topology and the characteristics of the flows. The comparison of the measurements made in non-reactive and reactive flow shows the influence of oxy-combustion on the dynamic and scalar development of the flow for this type of burners. (author)

  6. Long-term physiological alterations and recovery in a mouse model of separation associated with time-restricted feeding: a tool to study anorexia nervosa related consequences.

    Directory of Open Access Journals (Sweden)

    Sara Zgheib

    Full Text Available BACKGROUND: Anorexia nervosa is a primary psychiatric disorder, with non-negligible rates of mortality and morbidity. Some of the related alterations could participate in a vicious cycle limiting the recovery. Animal models mimicking various physiological alterations related to anorexia nervosa are necessary to provide better strategies of treatment. AIM: To explore physiological alterations and recovery in a long-term mouse model mimicking numerous consequences of severe anorexia nervosa. METHODS: C57Bl/6 female mice were submitted to a separation-based anorexia protocol combining separation and time-restricted feeding for 10 weeks. Thereafter, mice were housed in standard conditions for 10 weeks. Body weight, food intake, body composition, plasma levels of leptin, adiponectin, IGF-1, blood levels of GH, reproductive function and glucose tolerance were followed. Gene expression of several markers of lipid and energy metabolism was assayed in adipose tissues. RESULTS: Mimicking what is observed in anorexia nervosa patients, and despite a food intake close to that of control mice, separation-based anorexia mice displayed marked alterations in body weight, fat mass, lean mass, bone mass acquisition, reproductive function, GH/IGF-1 axis, and leptinemia. mRNA levels of markers of lipogenesis, lipolysis, and the brown-like adipocyte lineage in subcutaneous adipose tissue were also changed. All these alterations were corrected during the recovery phase, except for the hypoleptinemia that persisted despite the full recovery of fat mass. CONCLUSION: This study strongly supports the separation-based anorexia protocol as a valuable model of long-term negative energy balance state that closely mimics various symptoms observed in anorexia nervosa, including metabolic adaptations. Interestingly, during a recovery phase, mice showed a high capacity to normalize these parameters with the exception of plasma leptin levels. It will be interesting therefore to

  7. Polymeric membranes containing silver salts for propylene/propane separation

    Directory of Open Access Journals (Sweden)

    L. D. Pollo

    2012-06-01

    Full Text Available The separation of olefin/paraffin mixtures is one of the most important processes of the chemical industry. This separation is typically carried out by distillation, which is an energy and capital intensive process. One promising alternative is the use of facilitated transport membranes, which contain specific carrier agents in the polymer matrix that interact reversibly with the double bond in the olefin molecule, promoting the simultaneous increase of its permeability and selectivity. In this study, polyurethane (PU membranes were prepared using two different silver salts (triflate and hexafluorantimonate. The membranes were structurally characterized and their performance for the separation of propylene/propane mixtures was evaluated. The results of the characterization analyses indicated that the triflate salt was the most efficient carrier agent. The membranes containing this salt showed the best performance, reaching an ideal selectivity of 10 and propylene permeability of 188 Barrer.

  8. Optimization study of pressure-swing distillation for the separation process of a maximum-boiling azeotropic system of water-ethylenediamine

    Energy Technology Data Exchange (ETDEWEB)

    Fulgueras, Alyssa Marie; Poudel, Jeeban; Kim, Dong Sun; Cho, Jungho [Kongju National University, Cheonan (Korea, Republic of)

    2016-01-15

    The separation of ethylenediamine (EDA) from aqueous solution is a challenging problem because its mixture forms an azeotrope. Pressure-swing distillation (PSD) as a method of separating azeotropic mixture were investigated. For a maximum-boiling azeotropic system, pressure change does not greatly affect the azeotropic composition of the system. However, the feasibility of using PSD was still analyzed through process simulation. Experimental vapor liquid equilibrium data of water-EDA system was studied to predict the suitability of thermodynamic model to be applied. This study performed an optimization of design parameters for each distillation column. Different combinations of operating pressures for the low- and high-pressure columns were used for each PSD simulation case. After the most efficient operating pressures were identified, two column configurations, low-high (LP+HP) and high-low (HP+ LP) pressure column configuration, were further compared. Heat integration was applied to PSD system to reduce low and high temperature utility consumption.

  9. Comparative study of zeolite 5A and zeolite 13X in air separation by pressure swing adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Shokroo, Ehsan Javadi; Meymandi, Hadiseh Khalilpour; Yadollahi, Nadia [PART-SHIMI Knowledge Based Company, Shiraz (Iran, Islamic Republic of); Farsani, Danial Jafari [Bidboland Refining Co., NIGC, Bidboland (Iran, Islamic Republic of)

    2016-04-15

    The performance of zeolites 5A and 13X is numerically investigated in oxygen separation from air by a two-bed PSA system. The effect of operating variables such as adsorption step time, PH/PL ratio and cycle time was investigated on product purity and recovery. The simulation results showed that nitrogen adsorption capacity on zeolite 13X was slightly more than the one on zeolite 5A. In the completely same operating conditions, zeolite 5A had a larger mass transfer zone than zeolite 13X. Therefore, the adsorption and desorption rate of nitrogen on zeolite 5A is less than zeolite 13X. Moreover, for the equal volume of adsorbed nitrogen on both adsorbents, zeolite 5A is more capable rather than zeolite 13X to desorb much more volume of nitrogen at certain time. Furthermore, for achieving oxygen with purity of 96%, utilizing zeolite 5A is more economical than zeolite 13X, when 5.5

  10. Recovery of iron from copper tailings via low-temperature direct reduction and magnetic separation: process optimization and mineralogical study

    Science.gov (United States)

    Jiao, Rui-min; Xing, Peng; Wang, Cheng-yan; Ma, Bao-zhong; Chen, Yong-Qiang

    2017-09-01

    Currently, the majority of copper tailings are not effectively developed. Worldwide, large amounts of copper tailings generated from copper production are continuously dumped, posing a potential environmental threat. Herein, the recovery of iron from copper tailings via low-temperature direct reduction and magnetic separation was conducted; process optimization was carried out, and the corresponding mineralogy was investigated. The reduction time, reduction temperature, reducing agent (coal), calcium chloride additive, grinding time, and magnetic field intensity were examined for process optimization. Mineralogical analyses of the sample, reduced pellets, and magnetic concentrate under various conditions were performed by X-ray diffraction, optical microscopy, and scanning electron microscopy-energy-dispersive X-ray spectrometry to elucidate the iron reduction and growth mechanisms. The results indicated that the optimum parameters of iron recovery include a reduction temperature of 1150°C, a reduction time of 120 min, a coal dosage of 25%, a calcium chloride dosage of 2.5%, a magnetic field intensity of 100 mT, and a grinding time of 1 min. Under these conditions, the iron grade in the magnetic concentrate was greater than 90%, with an iron recovery ratio greater than 95%.

  11. What`s Wrong with Primary Separators?

    Energy Technology Data Exchange (ETDEWEB)

    Nilsen, F.P.; Davies, G.A.

    1996-12-31

    Primary separators are used to separate multiphase mixtures to produce bulk flows of gas/oil/water and to remove separate solids. This paper reviews the main process design criteria used in present design practice. The separators rely on gravity separation of the various phases. The mixtures to be separated do not always form readily separable systems, which can lead to malfunction, cross-entrainment and poor separation quality. Recent design methodologies are reviewed with a focus on reduced cross-entrainment and increased capacity (separation fluxes). Various equipment designs are discussed and an approach to system design is presented. When a primary separator is designed, it is essential that a full process specification and characterization data for the process fluids are available. It is important to select and design an effective inlet distributor accounting for the expected structure of the inlet flow. The use of internals to promote separation of gas/liquid and liquid/liquid mixtures are essential if maximum separation rates are to be achieved. Finally, a careful review of the use of chemicals must be carried out particularly with regard to the type, concentration and position of introduction. The paper was presented at The 3rd Major Conference on Current Developments in Production Separation Systems, 23 and 24 April 1996. 2 refs., 14 figs., 1 table

  12. Turbulence Modeling of Flows with Extensive Crossflow Separation

    Directory of Open Access Journals (Sweden)

    Argyris G. Panaras

    2015-07-01

    Full Text Available The reasons for the difficulty in simulating accurately strong 3-D shock wave/turbulent boundary layer interactions (SBLIs and high-alpha flows with classical turbulence models are investigated. These flows are characterized by the appearance of strong crossflow separation. In view of recent additional evidence, a previously published flow analysis, which attributes the poor performance of classical turbulence models to the observed laminarization of the separation domain, is reexamined. According to this analysis, the longitudinal vortices into which the separated boundary layer rolls up in this type of separated flow, transfer external inviscid air into the part of the separation adjacent to the wall, decreasing its turbulence. It is demonstrated that linear models based on the Boussinesq equation provide solutions of moderate accuracy, while non-linear ones and others that consider the particular structure of the flow are more efficient. Published and new Reynolds Averaged Navier–Stokes (RANS simulations are reviewed, as well as results from a recent Large Eddy Simulation (LES study, which indicate that in calculations characterized by sufficient accuracy the turbulent kinetic energy of the reverse flow inside the separation vortices is very low, i.e., the flow is almost laminar there.

  13. Intraspecific variations of Dekkera/Brettanomyces bruxellensis genome studied by capillary electrophoresis separation of the intron splice site profiles.

    Science.gov (United States)

    Vigentini, Ileana; De Lorenzis, Gabriella; Picozzi, Claudia; Imazio, Serena; Merico, Annamaria; Galafassi, Silvia; Piškur, Jure; Foschino, Roberto

    2012-06-15

    In enology, "Brett" character refers to the wine spoilage caused by the yeast Dekkera/Brettanomyces bruxellensis and its production of volatile phenolic off-flavours. However, the spoilage potential of this yeast is strain-dependent. Therefore, a rapid and reliable recognition at the strain level is a key point to avoid serious economic losses. The present work provides an operative tool to assess the genetic intraspecific variation in this species through the use of introns as molecular targets. Firstly, the available partial D./B. bruxellensis genome sequence was investigated in order to build primers annealing to introns 5' splice site sequence (ISS). This analysis allowed the detection of a non-random vocabulary flanking the site and, exploiting this feature, the creation of specific probes for strain discrimination. Secondly, the separation of the intron splice site PCR fragments was obtained throughout the set up of a capillary electrophoresis protocol, giving a 94% repeatability threshold in our experimental conditions. The comparison of results obtained with ISS-PCR/CE versus the ones performed by mtDNA RFLP revealed that the former protocol is more discriminating and allowed a reliable identification at strain level. Actually sixty D./B. bruxellensis isolates were recognised as unique strains, showing a level of similarity below 79% and confirming the high genetic polymorphism existing within the species. Two main clusters were grouped at similarity levels of about 46% and 47%, respectively, showing a poor correlation with the geographic area of isolation. Moreover, from the evolutionary point of view, the proposed technique could determine the frequency of the genome rearrangements that can occur in D./B. bruxellesis populations. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Radiochemical Studies on the Separation of Cesium, Cobalt, and Europium from Aqueous Solutions Using Zirconium Selenomolybdate Sorbent

    Directory of Open Access Journals (Sweden)

    H. El-Said

    2013-01-01

    Full Text Available A procedure for removal and separation of Cs, Eu and activation product of Co using zirconium selenomolybdate was developed. Interactions of 134Cs(I, 152,154Eu(III, and 60Co(II ions from HNO3 acid solutions with zirconium selenomolybdate matrix, dried at 50°C, have been individually investigated by the batch equilibration method. The sorption behavior of the three ions showed a selectivity sequence in the following order: Cs(I > Eu(III > Co(II. The breakthrough capacities of zirconium selenomolybdate for Cs(I, Eu(III and Co(II were found to be 0.82, 0.45, and 0.18 mmol/g of the sorbent, respectively. A mixture of the three radionuclides (1×10−2 M each in 140 mL of 1×10−2 M HNO3 solution was passed through 1 g zirconium selenomolybdate chromatographic column. Thereafter, quantitative elution of the retained Co(II was achieved with 14 mL of 1×10−1 M HNO3 acid solution leaving Eu(III and Cs(I strongly retained onto the column. Quantitative elution of Eu(III was achieved by passing 22 mL 2.5×10−1 M HNO3. About 89% of the retained Cs(I was eluted with 32 mL of 2 M NH4Cl solution at a flow rate of 0.5 mL/min.

  15. Generation and characterization of indoor fungal aerosols for inhalation studies

    DEFF Research Database (Denmark)

    Madsen, Anne Mette; Larsen, Søren T.; Koponen, Ismo K.

    2016-01-01

    containing107 CFU of fungi/m3 air were generated repeatedly from fungus-infested gypsum boards in a mouse exposure chamber. Aerosols contained Aspergillus nidulans, Aspergillus niger, Aspergillus ustus, Aspergillus versicolor, Chaetomium globosum, Cladosporium herbarum, Penicillium brevicompactum...... was to develop an inhalation exposure system to be able to examine responses in mice exposed to mixed fungal species aerosolized from fungus-infested building materials. Indoor airborne fungi were sampled and cultivated on gypsum boards. Aerosols were characterized and compared with aerosols in homes. Aerosols...... in the homes areassociated with water damage. Most fungi were present as single spores, but chains and clusters of different species and fragments were also present. The variation in exposure level during the 60 min of aerosol generation was similar to the variation measured in homes. Through aerosolization...

  16. Study 2.6 operations analysis mission characterization

    Science.gov (United States)

    Wolfe, R. R.

    1973-01-01

    An analysis of the current operations concepts of NASA and DoD is presented to determine if alternatives exist which may improve the utilization of resources. The final product is intended to show how sensitive these ground rules and design approaches are relative to the total cost of doing business. The results are comparative in nature, and assess one concept against another as opposed to establishing an absolute cost value for program requirements. An assessment of the mission characteristics is explained to clarify the intent, scope, and direction of this effort to improve the understanding of what is to be accomplished. The characterization of missions is oriented toward grouping missions which may offer potential economic benefits by reducing overall program costs. Program costs include design, development, testing, and engineering, recurring unit costs for logistic vehicles, payload costs. and direct operating costs.

  17. DC photogun vacuum characterization through photocathode lifetime studies

    Energy Technology Data Exchange (ETDEWEB)

    Marcy Stutzman; Joseph Grames; Matt Poelker; Kenneth Surles-Law; Philip Adderley

    2007-07-02

    Excellent vacuum is essential for long photocathode lifetimes in DC high voltage photoelectron guns. Vacuum Research at Thomas Jefferson National Accelerator Facility has focused on characterizing the existing vacuum systems at the CEBAF polarized photoinjector and on quantifying improvements for new systems. Vacuum chamber preprocessing, full activation of NEG pumps and NEG coating the chamber walls should improve the vacuum within the electron gun, however, pressure measurement is difficult at pressures approaching the extreme-high-vacuum (XHV) region and extractor gauge readings are not significantly different between the improved and original systems. The ultimate test of vacuum in a DC high voltage photogun is the photocathode lifetime, which is limited by the ionization and back-bombardment of residual gasses. Discussion will include our new load-locked gun design as well as lifetime measurements in both our operational and new photo-guns, and the correlations between measured vacuum and lifetimes will be investigated.

  18. An internet-based self-help intervention for older adults after marital bereavement, separation or divorce: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Brodbeck, Jeannette; Berger, Thomas; Znoj, Hans Joerg

    2017-01-13

    Marital bereavement and separation or divorce are among the most stressful critical life events in later life. These events require a dissolution of social and emotional ties, adjustments in daily routine and changes in identity and perspectives for the future. After a normative grief or distress reaction, most individuals cope well with the loss. However, some develop a prolonged grief reaction. Internet-based self-help interventions have proved beneficial for a broad range of disorders, including complicated grief. Based on the task model and the dual-process model of coping with bereavement, we developed a guided internet-based self-help intervention for individuals who experienced marital bereavement, separation or divorce at least 6 months prior to enrolment. The intervention consists of 10 text-based self-help sessions and one supportive email a week. The primary purpose of this study is the evaluation of the feasibility and efficacy of the intervention compared with a waiting control group. The secondary purpose is to compare the effects in bereaved and separated participants. Furthermore, we aim to analyze other predictors, moderators and mediators of the outcome, such as age, psychological distress and intensity of use of the intervention. The design is a randomized controlled trial with a waiting control condition of 12 weeks and a 24-weeks follow-up. At least 72 widowed or separated participants will be recruited via our study website and internet forums. Primary outcomes are reductions in grief symptoms, depression and psychological distress. Secondary outcome measures are related to loneliness, satisfaction with life, embitterment and the sessions. The trial will provide insights into the acceptance and efficacy of internet-based interventions among adults experiencing grief symptoms, psychological distress and adaptation problems in daily life after spousal bereavement, separation or divorce. Findings will add to existing knowledge by (1) evaluating

  19. Analysis of the separation of aquifers and potential shale gas source rocks: a national-scale screening study from the UK.

    Science.gov (United States)

    Bloomfield, John; Ward, Rob; Garcia-Bajo, Marieta; Hart, Alwyn

    2014-05-01

    A number of potential pathways can be identified for the migration of methane and contaminants associated with the shale gas extraction process to aquifers. These include the possible movement of contaminants from shale gas reservoirs that have been hydraulically fractured to overlying aquifers. The risk of contamination of an overlying aquifer is a function of i.) the separation of the potential shale gas source rock and the aquifer, ii.) the hydraulic characteristics (e.g. hydraulic conductivity, storage and hydrogeochemistry) of the rocks in the intervening interval, and iii.) regional and local physio-chemical gradients. Here we report on a national-scale study from the UK to assess the former, i.e. the vertical separation between potential shale gas source rocks and major aquifers, as a contribution to more informed management of the risks associated with shale gas development if and when it takes place in the UK. Eleven aquifers are considered in the study. These are aquifers that have been designated by the environment agencies of England (Environment Agency) and Wales (Natural Resources Wales) under the EU Water Framework Directive as being nationally important (Principal Aquifers). The shale gas source rocks have been defined on best publically available evidence for potential gas productivity and include both shales and clay formations. Based on a national geological fence diagram consisting of ~80 geological sections, totalling ~12,000km in length, down to >5km in depth, and with a typical spacing of 30km, the lower surfaces of each aquifer unit and upper surfaces of each shale/clay unit have been estimated at a spatial resolution of 3x3km. These surfaces have then been used to estimate vertical separations between pairs of shale/clay and aquifer units. The modelling process will be described and the aquifer, shale and separation maps presented and discussed. The aquifers are defined by geological units and since these geological units may be found at

  20. Synthesis, characterization and antibacterial studies of 2-chloro-5-fluoro-N-[dibenzyl carbamothioyl] benzamide thiourea

    Energy Technology Data Exchange (ETDEWEB)

    Sapari, Suhaila; Yamin, Bohari M.; Hasbullah, Aishah; Ibrahim, Nazlina [School of Chemical Science and Food Technology, Faculty of Science and Technology, The National University of Malaysia, 43600, Bangi, Selangor (Malaysia)

    2014-09-03

    Synthesis, characterization and antibacterial studies of 2-chloro-5-fluoro-N-[dibenzyl carbamothioyl] benzamide thiourea has been reported. The compound characterized by using elementary analysis CHNS, IR, {sup 1}H NMR and {sup 13}C NMR spectroscopies. The compounds have been screened for their antibacterial studies.

  1. Magnetic separation in microfluidic systems

    DEFF Research Database (Denmark)

    Smistrup, Kristian

    2007-01-01

    , and it is argued that it is a good measure, when comparing the performance of magnetic bead separators. It is described how numeric modelling is used to aid the design of microfluidic magnetic separation systems. An example of a design optimization study is given. A robust fabrication scheme has been developed...... for fabrication of silicon based systems. This fabrication scheme is explained, and it is shown how, it is applied with variations for several designs of magnetic separators. An experimental setup for magnetic separation experiments has been developed. It has been coupled with an image analysis program......This Ph.D. thesis presents theory, modeling, design, fabrication, experiments and results for microfluidic magnetic separators. A model for magnetic bead movement in a microfluidic channel is presented, and the limits of the model are discussed. The effective magnetic field gradient is defined...

  2. A Study on the Separation Distance to Protection of Buried Pipeline from Arc Strikes Caused by Power Line Ground Fault Current

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Tae Hyun; Bae, Jeong Hyo; Lee, Hyun Goo; Kim, Dae Kyong; Kim, Suk Won [Korea Electrotechnology Research Institute, Changwon (Korea)

    2002-07-01

    The demand of the power and gas energy have been rapidly increasing with the industralization, therefore, the area where buried pipelines run parallel with the adjacent power lines and cross them increases in Seoul as well as other cities. These situation cause AC interference from the power lines. However, there aren't any standards to preserve the pipelines from AC interference in Korea. This study introduces the separation distance to protection of buried pipeline from arc strikes caused by power line ground fault current. And this study examines and compares the arc distance through case study. (author). 6 refs., 1 fig., 2 tabs.

  3. Dynamic light scattering study on phase separation of a protein-water mixture: Application on cold cataract development in the ocular lens

    Science.gov (United States)

    Petta, V.; Pharmakakis, N.; Papatheodorou, G. N.; Yannopoulos, S. N.

    2008-06-01

    We present a detailed dynamic light scattering study of the phase separation in the ocular lens emerging during cold cataract development. Cold cataract is a phase separation effect that proceeds via spinodal decomposition of the lens cytoplasm with cooling. The intensity autocorrelation functions of the lens protein content are analyzed with the aid of two methods, providing information on the populations and dynamics of the scattering elements associated with cold cataract. It is found that the temperature dependence of many measurable parameters changes appreciably at the characteristic temperature ˜16±1°C which is associated with the onset of cold cataract. By extending the temperature range of this work to previously inaccessible regimes, i.e., well below the phase separation or coexistence curve at Tcc , we have been able to accurately determine the temperature dependence of the collective and self-diffusion coefficients of proteins near the spinodal. The analysis showed that the dynamics of proteins bears some resemblance to the dynamics of structural glasses, where the apparent activation energy for particle diffusion increases below Tcc , indicating a highly cooperative motion. Application of ideas developed for studying the critical dynamics of binary protein-solvent mixtures, as well as the use of a modified Arrhenius equation, enabled us to estimate the spinodal temperature Tsp of the lens nucleus. The applicability of dynamic light scattering as a noninvasive, early-diagnostic tool for ocular diseases is also demonstrated in light of the findings of the present paper.

  4. Deformation and failure characteristics of four types of lithium-ion battery separators

    Science.gov (United States)

    Zhang, Xiaowei; Sahraei, Elham; Wang, Kai

    2016-09-01

    Mechanical properties and failure mechanisms of battery separators play a crucial role in integrity of Lithium-ion batteries during an electric vehicle crash event. In this study, four types of commonly used battery separators are characterized and their mechanical performance, strength, and failure are compared. This includes two dry-processed polyethylene (PE) and trilayer separators, a wet-processed ceramic-coated separator, and a nonwoven separator. In detail, uniaxial tensile tests were performed along machine direction (MD), transverse direction (TD) and diagonal direction (DD). Also, through-thickness compression tests and biaxial punch tests were conducted. Comprehensive mechanical tests revealed interesting deformation and failure patterns under extreme mechanical loads. Last, a finite element model of PE separator was developed in LSDYNA based on the uniaxial tensile and through-thickness compression test data. The model succeeded in predicting the response of PE separator under punch tests with different sizes of punch head.

  5. Use of clomipramine in treatment of obsessive-compulsive disorder, separation anxiety and noise phobia in dogs: a preliminary, clinical study.

    Science.gov (United States)

    Seksel, K; Lindeman, M J

    2001-04-01

    To evaluate the efficacy and tolerance of a treatment protocol for obsessive-compulsive disorder, separation anxiety and noise phobia in dogs. A study was undertaken to assess clinical responses in 24 dogs diagnosed with one or more of three behavioural disorders stated above to a treatment regimen that included clomipramine and behaviour modification. A detailed behavioural and clinical history was obtained for each dog. Obsessive-compulsive disorder was diagnosed in nine cases: primary presenting complaints were tail-chasing, shadow-chasing, circling and chewing; one case was diagnosed with concurrent separation anxiety. Separation anxiety was diagnosed in 14 cases: presenting complaints included destruction, vocalisation and escaping in the absence of the owner; four cases also exhibited noise phobia. The study also included one dog diagnosed with noise phobia only and another with inappropriate fear responses. Clomipramine was administered orally twice daily. The starting dose was 1 to 2 mg/kg bodyweight. The dose was increased incrementally to a maximum of 4 mg/kg if needed. A behaviour modification program was designed and the owner instructed on its implementation. Dogs continued medication for at least 1 month after clinical signs disappeared or were acceptably reduced, then withdrawal of medication was attempted by decreasing drug dosage at weekly intervals while behaviour modification continued. The presenting clinical sign was largely improved or disappeared in 16 dogs, 5 demonstrated slight to moderate improvement and the behaviour was unchanged in 3. Clomipramine withdrawal was attempted in nine cases: this was successful in five. Clomipramine was effective and well-tolerated in controlling signs of obsessive-compulsive disorder and/or separation anxiety and/or noise phobia in 16 of 24 assessable cases, when used in combination with behaviour modification, and improvement in clinical signs was noted in 5 others.

  6. Magnetic separation of algae

    Science.gov (United States)

    Nath, Pulak; Twary, Scott N.

    2016-04-26

    Described herein are methods and systems for harvesting, collecting, separating and/or dewatering algae using iron based salts combined with a magnetic field gradient to separate algae from an aqueous solution.

  7. Separation anxiety in children

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/001542.htm Separation anxiety in children To use the sharing features on this page, please enable JavaScript. Separation anxiety in children is a developmental stage in which ...

  8. Separators for electrochemical cells

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Steven Allen; Anakor, Ifenna Kingsley; Farrell, Greg Robert

    2018-01-16

    Provided are separators for use in an electrochemical cell comprising (a) an inorganic oxide and (b) an organic polymer, wherein the inorganic oxide comprises organic substituents. Also provided are electrochemical cells comprising such separators.

  9. Experimental studies of tuned particle damper: Design and characterization

    Science.gov (United States)

    Zhang, Kai; Xi, Yanhui; Chen, Tianning; Ma, Zhihao

    2018-01-01

    To better suppress the structural vibration in the micro vibration and harsh environment, a new type of damper, tuned particle damper (TPD), was designed by combining the advantage of classical dynamic vibration absorber (DVA) and particle damper (PD). An equivalent theoretical model was established to describe the dynamic behavior of a cantilever system treated with TPD. By means of a series of sine sweep tests, the dynamic characteristic of TPD under different excitation intensity was explored and the damping performance of TPD was investigated by comparing with classical DVA and PD with the same mass ratio. Experimental results show that with the increasing of excitation intensity TPD shows two different dynamic characteristics successively, i.e., PD-like and DVA-like. TPD shows a wider suppression frequency band than classical DVA and better practicability than PD in the micro vibration environment. Moreover, to characterize the dynamic characteristic of TPD, a simple evaluation of the equivalent dynamic mass and equivalent dynamic damping of the cantilever system treated with TPD was performed by fitting the experimental data to the presented theoretical model. Finally, based on the rheology behaviors of damping particles reported by the previous research results, an approximate phase diagram which shows the motion states of damping particles in TPD was employed to analyze the dynamic characteristic of TPD and several motion states of damping particles in TPD were presented via a high-speed camera.

  10. Characterizing Cavities in Model Inclusion Fullerenes: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Francisco Torrens

    2001-06-01

    Full Text Available Abstract: The fullerene-82 cavity is selected as a model system in order to test several methods for characterizing inclusion molecules. The methods are based on different technical foundations such as a square and triangular tessellation of the molecular surface, spherical tessellation of the molecular surface, numerical integration of the atomic volumes and surfaces, triangular tessellation of the molecular surface, and cubic lattice approach to the molecular volume. Accurate measures of the molecular volume and surface area have been performed with the pseudorandom Monte Carlo (MCVS and uniform Monte Carlo (UMCVS methods. These calculations serve as a reference for the rest of the methods. The SURMO2 method does not recognize the cavity and may not be convenient for intercalation compounds. The programs that detect the cavities never exceed 1% deviation relative to the reference value for molecular volume and 5% for surface area. The GEPOL algorithm, alone or combined with TOPO, shows results in good agreement with those of the UMCVS reference. The uniform random number generator provides the fastest convergence for UMCVS and a correct estimate of the standard deviations. The effect of the internal cavity on the solvent-accessible surfaces has been calculated. Fullerene-82 is compared with fullerene-60 and -70.

  11. Europium polyoxometalates encapsulated in silica nanoparticles - characterization and photoluminescence studies

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Cristina S.; Granadeiro, Carlos M.; Cunha-Silva, Luis; Eaton, Peter; Balula, Salete S.; Pereira, Eulalia [REQUIMTE/Departamento de Quimica e Bioquimica, Faculdade de Ciencias, Universidade do Porto (Portugal); Ananias, Duarte [CICECO, Departamento de Quimica, Universidade de Aveiro (Portugal); Gago, Sandra [REQUIMTE, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica (Portugal); Feio, Gabriel [CENIMAT/I3N, Departamento de Ciencia dos Materiais, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, Monte de Caparica (Portugal); Carvalho, Patricia A. [ICEMS/Departamento de Bioengenharia, Instituto Superior Tecnico, Lisboa (Portugal)

    2013-06-15

    The incorporation of europium polyoxometalates into silica nanoparticles can lead to a biocompatible nanomaterial with luminescent properties suitable for applications in biosensors, biological probes, and imaging. Keggin-type europium polyoxometalates Eu(PW{sub 11}){sub x} (x = 1 and 2) with different europium coordination environments were prepared by using simple methodologies and no expensive reactants. These luminescent compounds were then encapsulated into silica nanoparticles for the first time through the water-in-oil microemulsion methodology with a nonionic surfactant. The europium polyoxometalates and the nanoparticles were characterized by using several techniques [FTIR, FT-Raman, {sup 31}P magic angle spinning (MAS) NMR, and TEM/energy-dispersive X-ray spectroscopy (TEM-EDS), AFM, dynamic light scattering (DLS), and inductively coupled plasma MS (ICP-MS) analysis]. The stability of the material and the integrity of the europium compounds incorporated were also examined. Furthermore, the photoluminescence properties of the Eu(PW{sub 11}){sub x} rate at SiO{sub 2} nanomaterials were evaluated and compared with those of the free europium polyoxometalates. The silica surface of the most stable nanoparticles was successfully functionalized with appropriate organosilanes to enable the covalent binding of oligonucleotides. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Characterization study of electric arc furnace dust phases

    Directory of Open Access Journals (Sweden)

    Janaína Gonçalves Maria da Silva Machado

    2006-03-01

    Full Text Available Electric arc furnace dust (EAFD is a solid waste generated in the collection of particulate material during steelmaking process in electric arc furnace. The aim of this work is to carry out a chemical and structural characterization of two EAFD samples with different Zn contents. Optical emission spectroscopy via inductively coupled plasma (ICP, X ray diffractometry (XRD and Mössbauer spectroscopy analysis were carried out in such EAFD samples. From XRD measurements, the samples exhibits the following phases: ZnFe2O4, Fe3O4, MgFe2O4, FeCr2O4, Ca0.15Fe2.85O4, MgO, Mn3O4, SiO2 and ZnO. The phases detected by Mössbauer spectroscopy were: ZnFe2O4, Fe3O4, Ca0.15Fe2.85O4 and FeCr2O4. Magnesium ferrite (MgFe2O4, observed in the XRD patterns as overlapped peaks, was not identified in the Mössbauer spectroscopy analysis.

  13. Characterization of Pedagogical Knowledge: A Study of Novice Teachers

    Directory of Open Access Journals (Sweden)

    Alejandro Almonacid-Fierro

    2014-09-01

    Full Text Available Pedagogical knowledge, understood as a specific display of paradigmatic and ideological narratives and configurations about the character and sense of the educational action, is ultimately what each teacher defines as the learning environment. Therefore, its characterization and categorization become a central concept of scientific and pedagogical knowledge. The main objective of this article was to investigate, describe and interpret the relationship between the practice shown in the classroom and the pedagogical knowledge from the teacher-learner relationship in novice teachers graduated from the School of Education of Universidad Autónoma de Chile. A qualitative research approach was used, based on the epistemological perspective of an interpretative paradigm, utilizing the subjective comprehension of the process. Participants emphasized the importance of practical experience as fundamental in their teacher training. In addition, they see positively the emphasis given by Universidad Autónoma de Chile on forming reflective, critical and autonomous teachers through a teaching practice focused on the co-construction of knowledge.

  14. Meniscus Membranes For Separation

    Science.gov (United States)

    Dye, Robert C.; Jorgensen, Betty; Pesiri, David R.

    2005-09-20

    Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

  15. Minor actinide separation by liquid-liquid extraction. World study system system overview; Separation des actinides mineurs par extraction liquide-liquide. Panorama des systemes etudies dans le monde

    Energy Technology Data Exchange (ETDEWEB)

    Madic, C.

    1994-12-31

    Long term management of nuclear wastes, coming from fuel reprocessing may be improved on one condition, to separate the long half-time radioisotopes. The mainest are {sup 237N}p,{sup 241A}m-{sup 243A}m, {sup 243C}m-{sup 245C}m. 1 fig.

  16. High-potential perfluorinated phthalocyanine-fullerene dyads for generation of high-energy charge-separated states: formation and photoinduced electron-transfer studies.

    Science.gov (United States)

    Das, Sushanta K; Mahler, Andrew; Wilson, Angela K; D'Souza, Francis

    2014-08-25

    High oxidation potential perfluorinated zinc phthalocyanines (ZnF(n)Pcs) are synthesised and their spectroscopic, redox, and light-induced electron-transfer properties investigated systematically by forming donor-acceptor dyads through metal-ligand axial coordination of fullerene (C60) derivatives. Absorption and fluorescence spectral studies reveal efficient binding of the pyridine- (Py) and phenylimidazole-functionalised fullerene (C60Im) derivatives to the zinc centre of the F(n)Pcs. The determined binding constants, K, in o-dichlorobenzene for the 1:1 complexes are in the order of 10(4) to 10(5) M(-1); nearly an order of magnitude higher than that observed for the dyad formed from zinc phthalocyanine (ZnPc) lacking fluorine substituents. The geometry and electronic structure of the dyads are determined by using the B3LYP/6-31G* method. The HOMO and LUMO levels are located on the Pc and C60 entities, respectively; this suggests the formation of ZnF(n)Pc(.+)-C60Im(.-) and ZnF(n)Pc(.+)-C60Py(.-) (n=0, 8 or 16) intra-supramolecular charge-separated states during electron transfer. Electrochemical studies on the ZnPc-C60 dyads enable accurate determination of their oxidation and reduction potentials and the energy of the charge-separated states. The energy of the charge-separated state for dyads composed of ZnF(n)Pc is higher than that of normal ZnPc-C60 dyads and reveals their significance in harvesting higher amounts of light energy. Evidence for charge separation in the dyads is secured from femtosecond transient absorption studies in nonpolar toluene. Kinetic evaluation of the cation and anion radical ion peaks reveals ultrafast charge separation and charge recombination in dyads composed of perfluorinated phthalocyanine and fullerene; this implies their significance in solar-energy harvesting and optoelectronic device building applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Unaccompanied and Separated Foreign Children in the Care System in the Western Cape – A Socio-Legal Study

    Directory of Open Access Journals (Sweden)

    Julia Sloth-Nielsen

    2016-05-01

    Full Text Available This article reports on the findings of a study of foreign children accommodated in the care system in the Western Cape, based on fieldwork conducted in child and youth care centres. The objectives of the study were firstly to map and quantify the number and demographics of foreign children placed in all CYCCs across the Western Cape. Secondly, the study aimed to analyse the reasons for children's migration and the circumstances around their placement in residential care institutions in order to establish whether family reunification was possible or desirable. Thirdly, the study explores the sufficiency of efforts made to trace and reunify the children with their families, whether in South Africa or across borders, as the institutional placement of children should not only be a last resort but it should preferably be temporary whilst family-based solutions are sought. Lastly, the documentation status of the children in the study was examined. Recommendations emanating from the research conclude the study.

  18. Safety shutdown separators

    Science.gov (United States)

    Carlson, Steven Allen; Anakor, Ifenna Kingsley; Farrell, Greg Robert

    2015-06-30

    The present invention pertains to electrochemical cells which comprise (a) an anode; (b) a cathode; (c) a solid porous separator, such as a polyolefin, xerogel, or inorganic oxide separator; and (d) a nonaqueous electrolyte, wherein the separator comprises a porous membrane having a microporous coating comprising polymer particles which have not coalesced to form a continuous film. This microporous coating on the separator acts as a safety shutdown layer that rapidly increases the internal resistivity and shuts the cell down upon heating to an elevated temperature, such as 110.degree. C. Also provided are methods for increasing the safety of an electrochemical cell by utilizing such separators with a safety shutdown layer.

  19. LC, MSn and LC–MS/MS studies for the characterization of degradation products of amlodipine

    Directory of Open Access Journals (Sweden)

    Ravi N. Tiwari

    2015-02-01

    Full Text Available In the present study, comprehensive stress testing of amlodipine (AM was carried out according to International Conference on Harmonization (ICH Q1A(R2 guideline. AM was subjected to acidic, neutral and alkaline hydrolysis, oxidation, photolysis and thermal stress conditions. The drug showed instability in acidic and alkaline conditions, while it remained stable to neutral, oxidative, light and thermal stress. A total of nine degradation products (DPs were formed from AM, which could be separated by the developed gradient LC method on a C18 column. The products formed under various stress conditions were investigated by LC–MS/MS analysis. The previously developed LC method was suitably modified for LC–MS/MS studies by replacing phosphate buffer with ammonium acetate buffer of the same concentration (pH 5.0. A complete fragmentation pathway of the drug was first established to characterize all the degradation products using LC–MS/MS and multi-stage mass (MSn fragmentation studies. The obtained mass values were used to study elemental compositions, and the total information helped with the identification of DPs, along with its degradation pathway. Keywords: Amlodipine, LC–MS/MS, Characterization, Degradation pathway

  20. Acoustofluidic bacteria separation

    Science.gov (United States)

    Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

  1. Novel aldehyde and thiosemicarbazone derivatives: Synthesis, spectroscopic characterization, structural studies and molecular docking studies

    Science.gov (United States)

    Karakurt, Tuncay; Tahtaci, Hakan; Subasi, Nuriye Tuna; Er, Mustafa; Ağar, Erbil

    2016-12-01

    In this study our purpose is that, synthesis and characterization of compounds containing the aldehyde and thiosemicarbazone groups and comparison of the theoretical results with the experimental results. The structures of all synthesized compounds were elucidated by IR, 1H NMR, 13C NMR, elemental analyses techniques. The structure of compound (4) (C9H8N4O2S) was also elucidated by X-ray diffraction analysis. In addition, the theoretical IR spectrum, 1H NMR and 13C NMR chemical shift values, frontier molecular orbital values (FMO) of these molecules were analyzed by using Becke-3- Lee-Yang-Parr (B3LYP) method with LanL2DZ basis set. Finally, molecular docking studies were performed on synthesized compounds using the 4DKI beta-lactam protein structure to determine the potential binding mode of inhibitors.

  2. Sessions and Separability in Security Protocols

    DEFF Research Database (Denmark)

    Carbone, Marco; Guttman, Joshua

    2013-01-01

    uncompromised subset of the participants are still guar- anteed that their interaction will respect sessions. A protocol transfor- mation turns any protocol into a session-respecting protocol. We do this via a general theory of separability. Our main theorem ap- plies to different separability requirements......, and characterizes when we can separate protocol executions sufficiently to meet a particular require- ment. This theorem also gives direct proofs of some old and new protocol composition results. Thus, our theory of separability appears to cover protocol composition and session-like behavior within a uniform frame...

  3. Moringa oleifera oil: Studies of characterization and biodiesel production

    Energy Technology Data Exchange (ETDEWEB)

    da Silva, Jhosianna P.V.; Serra, Tatiana M.; Meneghetti, Simoni M.P. [Universidade Federal de Alagoas, Instituto de Quimica e Biotecnologia, Laboratorio de Oleoquimica, Maceio, Alagoas, CEP 57072-970 (Brazil); Gossmann, Marcelo; Wolf, Carlos R.; Meneghetti, Mario R. [Universidade Luterana do Brasil, Instituto de Quimica, Canoas, Rio Grande do Sul, CEP 92420-280 (Brazil)

    2010-10-15

    This work describes studies with the seeds of Moringa oleifera (MO), obtained in the northeast of Brazil, evaluating some properties and chemical composition of the oil, as well any potential application in biodiesel production. The studied physicochemical properties of the MO biodiesel, suggest that this material may be used as fuel in diesel engines, mainly as a mixture to petrodiesel. (author)

  4. Preparation, characterization and in vitro study of biocompatible ...

    African Journals Online (AJOL)

    In this study, Bombyx mori silk based hydrogels were prepared and their biorelevant properties like physical, chemical and thermal properties were studied. Firstly, silk fibroin aqueous solution was prepared and the molecular weight of fibroin protein was determined followed by particle size analysis for the confirmation of ...

  5. Preparation, characterization and photocatalytic studies of Cu 2, Sn ...

    Indian Academy of Sciences (India)

    The photocatalytic activity of all the compounds was studied by degradation of methylene blue and methyl violet. The ion-substituted K5Sb5P2O20 have shown higher photocatalytic activity against both the dyes. The role of reactive intermediate species produced in the photocatalytic reaction was studied using their ...

  6. Advanced Aqueous Separation Systems for Actinide Partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Nash, Kenneth L.; Clark, Sue; Meier, G Patrick; Alexandratos, Spiro; Paine, Robert; Hancock, Robert; Ensor, Dale

    2012-03-21

    One of the most challenging aspects of advanced processing of spent nuclear fuel is the need to isolate transuranium elements from fission product lanthanides. This project expanded the scope of earlier investigations of americium (Am) partitioning from the lanthanides with the synthesis of new separations materials and a centralized focus on radiochemical characterization of the separation systems that could be developed based on these new materials. The primary objective of this program was to explore alternative materials for actinide separations and to link the design of new reagents for actinide separations to characterizations based on actinide chemistry. In the predominant trivalent oxidation state, the chemistry of lanthanides overlaps substantially with that of the trivalent actinides and their mutual separation is quite challenging.

  7. Multiscale study for stochastic characterization of shale samples

    Science.gov (United States)

    Tahmasebi, Pejman; Javadpour, Farzam; Sahimi, Muhammad; Piri, Mohammad

    2016-03-01

    Characterization of shale reservoirs, which are typically of low permeability, is very difficult because of the presence of multiscale structures. While three-dimensional (3D) imaging can be an ultimate solution for revealing important complexities of such reservoirs, acquiring such images is costly and time consuming. On the other hand, high-quality 2D images, which are widely available, also reveal useful information about shales' pore connectivity and size. Most of the current modeling methods that are based on 2D images use limited and insufficient extracted information. One remedy to the shortcoming is direct use of qualitative images, a concept that we introduce in this paper. We demonstrate that higher-order statistics (as opposed to the traditional two-point statistics, such as variograms) are necessary for developing an accurate model of shales, and describe an efficient method for using 2D images that is capable of utilizing qualitative and physical information within an image and generating stochastic realizations of shales. We then further refine the model by describing and utilizing several techniques, including an iterative framework, for removing some possible artifacts and better pattern reproduction. Next, we introduce a new histogram-matching algorithm that accounts for concealed nanostructures in shale samples. We also present two new multiresolution and multiscale approaches for dealing with distinct pore structures that are common in shale reservoirs. In the multiresolution method, the original high-quality image is upscaled in a pyramid-like manner in order to achieve more accurate global and long-range structures. The multiscale approach integrates two images, each containing diverse pore networks - the nano- and microscale pores - using a high-resolution image representing small-scale pores and, at the same time, reconstructing large pores using a low-quality image. Eventually, the results are integrated to generate a 3D model. The methods

  8. Is the rodent maternal separation model a valid and effective model for studies on the early-life impact on ethanol consumption?

    Science.gov (United States)

    Nylander, Ingrid; Roman, Erika

    2013-10-01

    Early-life events can cause long-term neurobiological and behavioural changes with a resultant effect upon reward and addiction processes that enhance risk to develop alcohol use disorders. Maternal separation (MS) is used to study the mediating mechanisms of early-life influences in rodents. In MS studies, the pups are exposed to maternal absence during the first postnatal weeks. The outcome of MS experiments exhibits considerable variation and questions have been raised about the validity of MS models. This short review aims to provide information about experimental conditions that are important to consider when assessing the impact of early-life environment on voluntary ethanol consumption. The results from currently used MS protocols are not uniform. However, studies consistently show that longer separations of intact litters predispose for higher ethanol consumption and/or preference in adult male rats as compared to shorter periods of MS. Studies using individual pup MS paradigms, other controls, low ethanol concentrations, adult females or examining adolescent consumption reported no differences or inconsistent results. There is no "a rodent MS model", there are several models and they generate different results. The compiled literature shows that MS is a model of choice for analysis of early-life effects on voluntary ethanol consumption but there are examples of MS paradigms that are not suitable. These studies emphasize the importance to carefully designed MS experiments to supply the optimal conditions to definitely test the research hypothesis and to be particulate in the interpretation of the outcome.

  9. Characterization of shallow groundwater quality in the Lower St. Johns River Basin: a case study

    Science.gov (United States)

    Ying Ouyang; Jia-En Zhang; Prem. Parajuli

    2013-01-01

    Characterization of groundwater quality allows the evaluation of groundwater pollution and provides information for better management of groundwater resources. This study characterized the shallow groundwater quality and its spatial and seasonal variations in the Lower St. Johns River Basin, Florida, USA, under agricultural, forest, wastewater, and residential land...

  10. Virus separation using membranes.

    Science.gov (United States)

    Grein, Tanja A; Michalsky, Ronald; Czermak, Peter

    2014-01-01

    Industrial manufacturing of cell culture-derived viruses or virus-like particles for gene therapy or vaccine production are complex multistep processes. In addition to the bioreactor, such processes require a multitude of downstream unit operations for product separation, concentration, or purification. Similarly, before a biopharmaceutical product can enter the market, removal or inactivation of potential viral contamination has to be demonstrated. Given the complexity of biological solutions and the high standards on composition and purity of biopharmaceuticals, downstream processing is the bottleneck in many biotechnological production trains. Membrane-based filtration can be an economically attractive and efficient technology for virus separation. Viral clearance, for instance, of up to seven orders of magnitude has been reported for state of the art polymeric membranes under best conditions.This chapter summarizes the fundamentals of virus ultrafiltration, diafiltration, or purification with adsorptive membranes. In lieu of an impractical universally applicable protocol for virus filtration, application of these principles is demonstrated with two examples. The chapter provides detailed methods for production, concentration, purification, and removal of a rod-shaped baculovirus (Autographa californica M nucleopolyhedrovirus, about 40 × 300 nm in size, a potential vector for gene therapy, and an industrially important protein expression system) or a spherical parvovirus (minute virus of mice, 22-26 nm in size, a model virus for virus clearance validation studies).

  11. Preparation, characterization and photocatalytic studies of Cu , Sn ...

    Indian Academy of Sciences (India)

    substituted K5Sb5P2O20 have shown higher photocatalytic activity against both the dyes. The role of reactive intermediate species produced in the photocatalytic reaction was studied using their appropriate scavengers. Keywords. Potassium ...

  12. Marriage, Separation and Beyond: A Longitudinal Study of Families of Children with Intellectual and Developmental Disabilities in a Norwegian Context

    Science.gov (United States)

    Tøssebro, Jan; Wendelborg, Christian

    2017-01-01

    Background: This study addresses family structure in families raising a child with disabilities in Norway. The aims are to add to the literature on termination of parental relationships and to explore family research topics that are rarely discussed in disability research, such as cohabitation versus marriage and repartnering. Methods:…

  13. A Case Study Showing How One Young Child Represented Issues Concerned with Attachment and Separation in Her Spontaneous Explorations

    Science.gov (United States)

    Arnold, Cath

    2009-01-01

    This paper presents a case study of a young child, demonstrating evidence of a connection between "enveloping" objects and understanding presence and absence of a temporary and permanent nature. The starting point for the researcher was: an interest in identifying schemas or repeated patterns in order to understand cognitive development and; a…

  14. Separate and joint associations of occupational and leisure-time sitting with cardio-metabolic risk factors in working adults: a cross-sectional study.

    Science.gov (United States)

    Saidj, Madina; Jørgensen, Torben; Jacobsen, Rikke K; Linneberg, Allan; Aadahl, Mette

    2013-01-01

    The workplace is a main setting for prolonged sitting for some occupational groups. Convincing evidence has recently accumulated on the detrimental cardio-metabolic health effects of leisure-time sitting. Yet, much less is known about occupational sitting, and the potential health risk attached compared to leisure-time sitting. To explore the separate and joint associations of occupational and leisure-time sitting with cardio-metabolic risk factors in working adults. All working adults (N = 2544) from the Health2006, a Danish population-based study, were included in this cross-sectional study. Participants reported hours of sitting during work, during leisure-time along with socio-demographic and behavioral characteristics, including physical activity. Cardio-metabolic risk factors (waist circumference, body mass index, body fat percentage, total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, insulin, hemoglobin A1c and plasma glucose) were measured. Associations were explored by linear regression for leisure-time, occupational, and overall sitting time. Statistically significant (passociations of leisure-time sitting were observed with all cardio-metabolic risk factors, except hemoglobin A1c and plasma glucose. Similarly, occupational sitting time was significantly detrimentally associated with HDL cholesterol, triglycerides, and insulin. For categories of sitting time, a joint adverse association of sitting much during both work-time and leisure-time was observed. The associations of occupational sitting time with cardio-metabolic risk factors were fewer and weaker compared to leisure-time sitting. Yet, the joint associations of occupational and leisure-time sitting with cardio-metabolic risk factors were higher than the separate. Our findings amplify the need for further focus in this area prior to making assumptions about equivalent health risks across sedentary behaviors. To our knowledge, this is the first study to contrast the deleterious

  15. Study of the influence of gas flow on PECVD diamond growth: influence of the separate injection of gases

    Science.gov (United States)

    Mesbahi, A.; Silva, F.

    2017-11-01

    This study is a follow-up to previously published modeling work examining a bell jar microwave plasma CVD reactor operating at high pressure (Mesbahi et al 2013 J. Phys. D: Appl. Phys. 46 385502). In this paper, we present the influence of gas injection mode on flow structure, on the production and coupled transport of diamond growth key species, and on the resulting diamond growth. Several gas injection configurations have been tested and experimental results in terms of growth rate and thickness uniformity will be compared with numerical simulations. In this study, we found that direct injection of methane closer to the discharge allowed one to significantly increase the diamond growth rate. These results will be discussed using a non-dimensional analysis of the transport phenomena (mass, energy and momentum by convection and diffusion) and production of the CH3 radical in the reactor.

  16. A pilot study on the isolation and biochemical characterization of ...

    African Journals Online (AJOL)

    In recent times, there has been a renewed interest in the search of plant growth promoting rhizobacteria (PGPR) for sustainable crop production. Rice is an economically important food crop, which is subjected to infection by a host of fungal, viral and bacterial pathogens. In this study, an attempt was made to isolate ...

  17. Synthesis, characterization and study of catalytic activity of Silver ...

    Indian Academy of Sciences (India)

    Catalytic activity was tested using liquid-phase selective oxidation of benzylic alcohols to aldehydes. The influence of some parameters such as optimum weight of Ag, catalyst dosage, oxidant and various solvents were studied. The superior catalytic performance of the Ag/ZnO nanocomposite was observed in microwave ...

  18. Synthesis, characterization and isotherm studies of new composite ...

    Indian Academy of Sciences (India)

    Sorption isotherm studies of La 3 + , Ce 3 + , Nd 3 + and Sm 3 + ions were performed at differentreaction temperatures and analysed by Langmuir, Freundlich, Dubinin–Raduchkivich and Temkin isotherm models. Thermodynamic parameters such as Δ G ∘ , Δ H ∘ and Δ S ∘ were determined and found to be endothermic ...

  19. Studies on preparation and characterization of indium doped zinc ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. The preparation of indium doped zinc oxide films is discussed. Variation of structural, electrical and optical properties of the films with zinc acetate concentration and indium concentration in the solution are investigated. XRD studies have shown a change in preferential orientation from (002) to (101) crystal.

  20. Optical characterization and x-ray diffraction studies of synthetic ...

    African Journals Online (AJOL)

    ... lime and the resulting calcium chloride solution was reacted with dilute sulphuric acid. Calcinations were done at a constant o temperature of 120 C for a period of four hours. The choice of the production parameters was guided by the findings of previous studies. Optical absorption spectra of the samples were measured ...