WorldWideScience

Sample records for capture-s solid phase

  1. Capture-S, a nontreponemal solid-phase erythrocyte adherence assay for serological detection of syphilis.

    OpenAIRE

    Stone, D L; Moheng, M C; Rolih, S; Sinor, L T

    1997-01-01

    A solid-phase erythrocyte adherence assay has been developed for the serological detection of reagin antibodies in syphilis. Capture-S (Immucor, Inc., Norcross, Ga.) is a nontreponemal, qualitative screening test for the detection of immunoglobulin G (IgG) and IgM antilipid antibodies in serum or plasma samples from blood donors. The Capture-S assay utilizes a modified Venereal Disease Research Laboratory antigen bound to microtitration wells and anti-IgG- plus anti-IgM-coated indicator eryth...

  2. Solid phase transformations II

    CERN Document Server

    Čermák, J

    2009-01-01

    This topical volume includes ten invited papers that cover selected areas of the field of solid phase transformations. The first two contributions represent a burgeoning branch; that of the computer simulation of physical phenomena. The following three articles deal with the thermodynamics of phase transformations as a basic theory for describing the phenomenology of phase changes in matter. The next paper describes the interconnections between structural stability and the electronic structure of phases. Two further articles are devoted to displacive transformations; a field where there are ma

  3. Solid phase transformations

    CERN Document Server

    Čermák, J

    2008-01-01

    This special-topic book, devoted to ""Solid Phase Transformations"" , covers a broad range of phenomena which are of importance in a number of technological processes. Most commercial alloys undergo thermal treatment after casting, with the aim of imparting desired compositions and/or optimal morphologies to the component phases. In spite of the fact that the topic has lain at the center of physical metallurgy for a long time, there are numerous aspects which are wide open to potential investigative breakthroughs. Materials with new structures also stimulate research in the field, as well as n

  4. Solid-phase microextraction

    DEFF Research Database (Denmark)

    Nilsson, Torben

    The objective of this study has been to develop new analytical methods using the rapid, simple and solvent-free extraction technique solid-phase microextraction (SPME) for the quantitative analysis of organic pollutants at trace level in drinking water and environmental samples. The dynamics of...... SPME were examined for halogenated and non-halogenated volatile hydrocarbons, and a standard method for their quantitative analysis in aqueous samples was developed and validated in inter-laboratory studies on the basis of reference material and in comparison with the traditional methods. The...... influences of some possible interferences on the SPME process were examined, and new SPME probes were tested for the in situ monitoring of groundwater pollutants. Inter-laboratory studies were carried out also for the validation of SPME for the quantitative analysis of organochlorine, organonitrogen and...

  5. Solid-Phase Random Glycosylation

    DEFF Research Database (Denmark)

    Agoston, K.; Kröger, Lars; Dekany, Gyula;

    2009-01-01

    Two different approaches were employed to study solid phase random glycosylations to obtain oligosaccharide libraries. In approach I, Wang resin esters were attached to the acceptors structures. Following their glycosylation and resin cleavage, the peracetylated components of the oligosaccharide...

  6. Solid-phase peptide synthesis

    DEFF Research Database (Denmark)

    Jensen, Knud Jørgen

    This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective....

  7. SOLID PHASE SYNTHESIS OF ISOXAZOLINES

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The solid-phase synthesis of isoxazolines on 2-polystyrylsulfonamidoethanol resin isreported. 2-Polystyrylsuifonamidoethanol resin 1 was reacted with acryloyl chloride to afford2-polystyrylsulfonylamidoethyl acrylate resin 2, which was further reacted with brominatedaldoximes by [3+2] cycioaddition to give isoxazoline resin 4. Resin 4 was treated with aqueous 6mol/L HCI solution to obtain isoxazolines in good yield and purity.

  8. SOLID PHASE SYNTHESIS OF ISOXAZOLINES

    Institute of Scientific and Technical Information of China (English)

    SUNWeimin; LUOJuntao; 等

    2002-01-01

    The solid-phase synthesis of isoxazolines on 2-polystyrylsulfonamidoethanol resin is reported.2-Polystyrylsulfonamidoethanol resin 1 was reacted with acryloyl chloride to afford 2-polystyrylsulfonylamidoethyl acrylate resin 2,which was further reacted with brominated aldoximes by [3+2] cycloaddition to give isoxazoline resin 4.Resin 4 was treated with aqueous 6 mol/L HCl solution to obtain isoxazolines in good yield and purity.

  9. Solid Phase Characterization of Solids Recovered from Failed Sluicer Arm

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, Gary A.

    2015-03-09

    The Enclosure to this memo discusses the solid phase characterization of a solid sample that was retrieved from the single-shell Tank 241-C-111 extended reach sluicer #2. This sluicer, removed from riser #3 on September 25, 2014, was found to have approximately 0.4 gallons of solid tank waste adhering to the nozzle area.

  10. Solid-solid phase transformation kinetics

    OpenAIRE

    Bauer, Rico

    2010-01-01

    Chapter 2 of this thesis presents the investigation of the microstructural evolution of Co precipitates formed upon isochronal annealing of an initially supersaturated Au 10.12 at. % Co solid solution. It was proven, that initially plate like bcc Co precipitates have formed, which deviates from the expected stable fcc Co crystal structure. Upon prolonged annealing, i. e. with ongoing precipitation reaction, the bcc Co was transformed into fcc Co accompanied with a morphological change of th...

  11. Molecular Modeling of Solid Fluid Phase Behavior

    Energy Technology Data Exchange (ETDEWEB)

    Peter A. Monson

    2007-12-20

    This report gives a summary of the achievements under DOE contract No. DOE/ER/14150 during the period September 1, 1990 to December 31, 2007. This project was concerned with the molecular modeling of solid-fluid equilibrium. The focus was on understanding how solid-fluid and solid-solid phase behavior are related to molecular structure, and the research program made a seminal contribution in this area. The project led to 34 journal articles, including a comprehensive review article published in Advances in Chemical Physics. The DOE funding supported the work of 5 Ph.D. students, 2 M.S. students and 5 postdoctoral researchers.

  12. Binary Solid-Liquid Phase Equilibria

    Science.gov (United States)

    Ellison, Herbert R.

    1978-01-01

    Indicates some of the information that may be obtained from a binary solid-liquid phase equilibria experiment and a method to write a computer program that will plot an ideal phase diagram to which the experimental results may be compared. (Author/CP)

  13. Phase equilibria in isotropic solids

    Czech Academy of Sciences Publication Activity Database

    Šilhavý, Miroslav

    2013-01-01

    Roč. 25, č. 6 (2013), s. 795-802. ISSN 0935-1175 Institutional support: RVO:67985840 Keywords : phase transitions * equilibrium * interfaces Subject RIV: BA - General Mathematics Impact factor: 1.431, year: 2013 http://link.springer.com/article/10.1007%2Fs00161-012-0282-5

  14. Amorphous Phase Properties Of Oriented Polyethylene Solids

    OpenAIRE

    Zahran, R. R; Kardos, J. L.

    1993-01-01

    Solid-state deformation of polyethylene results in a preferential orientation of both crystalline and amorphous regions. Usually, one major problem in the prediction of the mechanical and thermal expansion properties of anisotropic polyethylene lies in determining values for the amorphous phase properties and, particularly, at a given level of solid-state deformation. This paper outlines simple procedures for determining the two-dimensional amorphous orientation function and values for the...

  15. Multiplexed Colorimetric Solid-Phase Extraction

    Science.gov (United States)

    Gazda, Daniel B.; Fritz, James S.; Porter, Marc D.

    2009-01-01

    Multiplexed colorimetric solid-phase extraction (MC-SPE) is an extension of colorimetric solid-phase extraction (C-SPE) an analytical platform that combines colorimetric reagents, solid phase extraction, and diffuse reflectance spectroscopy to quantify trace analytes in water. In CSPE, analytes are extracted and complexed on the surface of an extraction membrane impregnated with a colorimetric reagent. The analytes are then quantified directly on the membrane surface using a handheld diffuse reflectance spectrophotometer. Importantly, the use of solid-phase extraction membranes as the matrix for impregnation of the colorimetric reagents creates a concentration factor that enables the detection of low concentrations of analytes in small sample volumes. In extending C-SPE to a multiplexed format, a filter holder that incorporates discrete analysis channels and a jig that facilitates the concurrent operation of multiple sample syringes have been designed, enabling the simultaneous determination of multiple analytes. Separate, single analyte membranes, placed in a readout cartridge create unique, analyte-specific addresses at the exit of each channel. Following sample exposure, the diffuse reflectance spectrum of each address is collected serially and the Kubelka-Munk function is used to quantify each water quality parameter via calibration curves. In a demonstration, MC-SPE was used to measure the pH of a sample and quantitate Ag(I) and Ni(II).

  16. Directed evolution and solid phase enzyme screening

    Science.gov (United States)

    Bylina, Edward J.; Grek, Christina L.; Coleman, William J.; Youvan, Douglas C.

    2000-03-01

    A new digital imaging spectrophotometer and a series of colorimetric solid phase arrays have been developed to screen bacterial libraries expressing mutagenized enzymes undergoing directed evolution. This high-throughput solid- phase array system (known as `Kcat Technology') can detect less than a 20% difference in enzyme rates within microcolonies grown at a nearly confluent density of 500 colonies per cm2 on an assay disk. Each microcolony is analyzed simultaneously at single-pixel resolution (1.5 megapixels; 75 micron/pixel), requiring less than 100 nanoliters of substrate per measurement, a 1000-fold reduction over conventional liquid phase assays. Here we report the successful identification of variants of Agrobacterium (beta) -glucosidase--a glycosidase with broad substrate specificity that favors cleavage of glucosides over galactosides--by simultaneously assaying two different substrates tagged with spectrally distinct chromogenic reporters.

  17. DNA Extraction: Organic and Solid-Phase.

    Science.gov (United States)

    Altayari, Wafa

    2016-01-01

    DNA extraction remains a critical step in DNA profiling of biological material recovered from scenes of crime. In the forensic community several methods have gained popularity, including Chelex(®), organic extraction, and solid-phase extraction. While some laboratories streamlined their processes and only use one method we have retained several methods and continue to use these for different sample types. In this chapter we present three methods that have been used for several years in our laboratory. PMID:27259731

  18. Solid-phase fluoroimmunoassay for treponemal antibody.

    OpenAIRE

    Stevens, R W; Schell, R F

    1982-01-01

    An objective, solid-phase fluoroimmunoassay for treponemal antibody was developed with a lysate of virulent Treponema pallidum (Nichols strain) adsorbed on cellulose acetate disks. A probe containing both the antigen and control disks is inserted successively into a serum specimen dilution, a buffer rinse, fluoroscein isothiocyanate-conjugated goat anti-human immunoglobulin G, and a second buffer rinse. Fluorescence signal units are measured with a fluorometer. To establish test calibration c...

  19. Elementary excitations and phase transformations in solids

    International Nuclear Information System (INIS)

    Neutron scattering is and will continue to be a uniquely powerful tool for the study of elementary excitations and phase transformations in solids. The paper examines a few recent experiments on molecular crystals, superionic materials, paramagnetic scattering and phase transitions to see what experimental features made these experiments possible, and hence to make suggestions about future needs. It is concluded that new instruments will extend the scope of neutron scattering studies to new excitations, that there is a need for higher resolution, particularly for phase transition studies, and that it will be important to use intensity information, discrimination against unwanted inelastic processes and polarization analysis to reliably measure the excitations in new materials. (author)

  20. Solid drop based liquid-phase microextraction.

    Science.gov (United States)

    Ganjali, Mohammad Reza; Sobhi, Hamid Reza; Farahani, Hadi; Norouzi, Parviz; Dinarvand, Rassoul; Kashtiaray, Amir

    2010-04-16

    Solid drop based liquid-phase microextraction (SDLPME) is a novel sample preparation technique possessing obvious advantages of simple operation with a high pre-concentration factor, low cost and low consumption of organic solvent. SDLPME coupled with gas chromatography (GC), high-performance liquid chromatography (HPLC), and atomic absorption spectrometry (AAS) has been widely applied to the analyses of a different variety of samples. The basic principles, parameters affecting the extraction efficiency, and the latest applications of SDLPME are reviewed in this article. PMID:19962710

  1. Preparation and characterization of a novel polymeric based solid-solid phase change heat storage material

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Peng; Cheng, Bowen [Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, Tianjin Polytechnic University, Tianjin 300160 (China); Gu, Xiaohua [Qiqihar University, 30 Wenhua Road, Qiqihar 161006 (China); CAS Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Center for Molecular Science, Institute of Chemistry, The Chinese Academy of Sciences, Beijing 100080 (China); Wang, Yufei [Dalian University Technology, Dalian 116024 (China)

    2009-06-15

    Here we reported a two-step procedure for preparing a novel polymeric based solid-solid phase change heat storage material. Firstly, a copolymer monomer containing a polyethylene glycol monomethyl ether (MPEG) phase change unit and a vinyl unit was synthesized via the modification of hydrogen group of MPEG. Secondly, by copolymerization of the copolymer monomer and phenyl ethylene, a novel polymeric based solid-solid phase change heat storage material was prepared. The composition, structure and properties of the novel polymeric based solid-solid phase change material were characterized by IR, {sup 1}H NMR, DSC, WAXD, and POM, respectively. The results show that the novel polymeric based solid-solid phase change material possesses of excellent crystal properties and high phase change enthalpy. (author)

  2. Preparation and characterization of a novel polymeric based solid-solid phase change heat storage material

    Energy Technology Data Exchange (ETDEWEB)

    Xi Peng [Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, Tianjin Polytechnic University, Tianjin 300160 (China); Gu Xiaohua [Qiqihar University, 30 Wenhua Road, Qiqihar 161006 (China); CAS Key Laboratory of Engineering Plastics, Joint Laboratory of Polymer Science and Materials, Center for Molecular Science, Institute of Chemistry, The Chinese Academy of Sciences, Beijing 100080 (China)], E-mail: gxh218@yahoo.cn; Cheng Bowen [Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, Tianjin Polytechnic University, Tianjin 300160 (China); Wang Yufei [Dalian University Technology, Dalian 116024 (China)

    2009-06-15

    Here we reported a two-step procedure for preparing a novel polymeric based solid-solid phase change heat storage material. Firstly, a copolymer monomer containing a polyethylene glycol monomethyl ether (MPEG) phase change unit and a vinyl unit was synthesized via the modification of hydrogen group of MPEG. Secondly, by copolymerization of the copolymer monomer and phenyl ethylene, a novel polymeric based solid-solid phase change heat storage material was prepared. The composition, structure and properties of the novel polymeric based solid-solid phase change material were characterized by IR, {sup 1}H NMR, DSC, WAXD, and POM, respectively. The results show that the novel polymeric based solid-solid phase change material possesses of excellent crystal properties and high phase change enthalpy.

  3. Combinatorial Solid-Phase Synthesis of Balanol Analogues

    DEFF Research Database (Denmark)

    Nielsen, John; Lyngsø, Lars Ole

    1996-01-01

    The natural product balanol has served as a template for the design and synthesis of a combinatorial library using solid-phase chemistry. Using a retrosynthetic analysis, the structural analogues have been assembled from three relatively accessible building blocks. The solid-phase chemistry inclu...

  4. Solid-solid phase transitions determined by differential scanning calorimetry.

    Science.gov (United States)

    Murrill, E.; Whitehead, M. E.; Breed, L.

    1972-01-01

    Data are presented to show that tris(hydroxymethyl)acetic acid, monochloropentaerythritol, monofluoropentaerythritol, difluoropentaerythritol, monoaminopentaerythritol, and diaminopentaerythritol exhibit solid-state transitions to a plastic crystalline state. Transitional enthalpies in many of these substances are lower than might be expected by analogy with related structures, suggesting that some configurational contributions to their entropy increments have been inhibited.

  5. Analysis of solid-liquid phase change heat transfer enhancement

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Yinping(张寅平); WANG; Xin(王馨)

    2002-01-01

    Solid-liquid phase change processes have two important features: the process is an approximately isothermal process and the heat of fusion of phase change material tends to be much greater than its specific heat. Therefore, if any phase change material adjacent to a hot or cold surface undergoes phase change, the heat transfer rate on the surface will be noticeably enhanced. This paper presents a novel insight into the mechanisms of heat transfer enhancement induced by solid-liquid phase change based on the analogy analysis for heat conduction with an internal heat source and solid-liquid phase change heat transfer. Three degrees of surface heat transfer enhancement for different conditions are explored, and corresponding formulae are written to describe them. The factors influencing the degrees of heat transfer enhancement are clarified and their effects quantitatively analyzed. Both the novel insight and the analysis contribute to effective application of phase change heat transfer enhancement technique.

  6. Crystal-Phase Control by Solution-Solid-Solid Growth of II-VI Quantum Wires.

    Science.gov (United States)

    Wang, Fudong; Buhro, William E

    2016-02-10

    A simple and potentially general means of eliminating the planar defects and phase alternations that typically accompany the growth of semiconductor nanowires by catalyzed methods is reported. Nearly phase-pure, defect-free wurtzite II-VI semiconductor quantum wires are grown from solid rather than liquid catalyst nanoparticles. The solid-catalyst nanoparticles are morphologically stable during growth, which minimizes the spontaneous fluctuations in nucleation barriers between zinc blende and wurtzite phases that are responsible for the defect formation and phase alternations. Growth of single-phase (in our cases the wurtzite phase) nanowires is thus favored. PMID:26731426

  7. Wax Precipitation Modeled with Many Mixed Solid Phases

    DEFF Research Database (Denmark)

    Heidemann, Robert A.; Madsen, Jesper; Stenby, Erling Halfdan;

    2005-01-01

    The behavior of the Coutinho UNIQUAC model for solid wax phases has been examined. The model can produce as many mixed solid phases as the number of waxy components. In binary mixtures, the solid rich in the lighter component contains little of the heavier component but the second phase shows sub......-temperature and low-temperature forms, are pure. Model calculations compare well with the data of Pauly et al. for C18 to C30 waxes precipitating from n-decane solutions. (C) 2004 American Institute of Chemical Engineers....

  8. Automated solid-phase synthesis of oligosaccharides containing sialic acids

    Directory of Open Access Journals (Sweden)

    Chian-Hui Lai

    2015-05-01

    Full Text Available A sialic acid glycosyl phosphate building block was designed and synthesized. This building block was used to prepare α-sialylated oligosaccharides by automated solid-phase synthesis selectively.

  9. The Structural Phase Transition in Solid DCN

    DEFF Research Database (Denmark)

    Dietrich, O. W.; Mackenzie, Gordon A.; Pawley, G. S.

    1975-01-01

    Neutron scattering measurements on deuterated hydrogen cyanide have shown that the structural phase change from a tetragonal to an orthorhombic form at 160K is a first-order transition. A transverse acoustic phonon mode, which has the symmetry of the phase change, was observed at very low energies...

  10. The Structural Phase Transition in Solid DCN

    DEFF Research Database (Denmark)

    Dietrich, O. W.; Mackenzie, Gordon A.; Pawley, G. S.

    1975-01-01

    Neutron scattering measurements on deuterated hydrogen cyanide have shown that the structural phase change from a tetragonal to an orthorhombic form at 160K is a first-order transition. A transverse acoustic phonon mode, which has the symmetry of the phase change, was observed at very low energie...

  11. Low-temperature solid-phase chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Baluev, A.V.; Mityakhina, V.S.; Rogozev, B.I.; Silin, M.Yu.

    1987-06-01

    This paper is concerned with the possibility of solid-phase reactions carried out at 20-25 degrees C. A variety of solid complexes are ground and tested for their reaction capacity in the solid phase with acid phosphates, including complexes of iron, cesium, sodium, tin, and uranyl, using Moessbauer and infrared spectroscopy and thermal analysis. The reactions are considered viable not only because they avoid the expenditure of energy otherwise needed to heat the reactants but also because they provide a new method for the preparation of complex coordination compounds.

  12. Phase transition in solid molecular hydrogen at ultrahigh pressures

    Science.gov (United States)

    Hemley, R. J.; Mao, H. K.

    1988-01-01

    Solid normal hydrogen was compressed in a diamond-anvil cell to pressures above 200 GPa. Spontaneous Raman spectra demonstrate that the solid undergoes a structural phase transformation beginning at 145 GPa at 77 K, as evidenced by an abrupt discontinuity in the intramolecular vibron frequency as a function of pressure. The magnitude of the vibron-frequency shift and the pressure-temperature conditions of the phase transformation are consistent with its identification as the theoretically predicted pressure-induced orientational ordering of the molecular solid.

  13. Magnetic Solid Phase Extraction Applied to Food Analysis

    Directory of Open Access Journals (Sweden)

    Israel S. Ibarra

    2015-01-01

    Full Text Available Magnetic solid phase extraction has been used as pretreatment technique for the analysis of several compounds because of its advantages when it is compared with classic methods. This methodology is based on the use of magnetic solids as adsorbents for preconcentration of different analytes from complex matrices. Magnetic solid phase extraction minimizes the use of additional steps such as precipitation, centrifugation, and filtration which decreases the manipulation of the sample. In this review, we describe the main procedures used for synthesis, characterization, and application of this pretreatment technique which were applied in food analysis.

  14. A novel solid-solid phase change heat storage material with polyurethane block copolymer structure

    International Nuclear Information System (INIS)

    A novel polymeric solid-solid phase change heat storage material (PCM) with polyurethane block copolymer structure (PUPCM) composed of high molecule weight polyethylene glycol (PEG) as soft segment, 4,4'-diphenylmethane diissyanate (MDI) and 1,4-butanediol (BDO) as a chain extender were synthesized by a two step process. DSC, POM, SEM and WAXD tests were performed to investigate the phase transition behaviors and crystalline morphology. The results indicated that the PUPCM showed typical solid-solid phase transition properties, e.g. suitable transition temperature, high transition enthalpy and good thermal stability. It is a functional polyurethane with good energy storage effect, and the heat storage mechanism of PUPCM is the transfer between crystalline and amorphous states of the soft segment PEG of PUPCM, and the hard segment, serving as 'physical cross-links', restricted the molecular chain of the soft segment's free movement at high temperature. Thus, PUPCM can keep its solid state in the transition processing

  15. Integral dosimetric methods using solid phase

    International Nuclear Information System (INIS)

    Current methods are described used for personnel dosimetry based on solid state radiation effects. They mainly include thermoluminescence and radiophotoluminescence. The development is going on of a silicon diode for the dosimetry of fast neutrons and the use is studied of MOSFET transistors. Simple output signal processing is the advantage of another method, thermostimulated conductivity. The lyoluminescence method is also prospective since a number of compounds contained in biological tissue show lyoluminescence and biological material can thus be directly used as a dosemeter. (Ha)

  16. Solid state phase detector replaces bulky transformer circuit

    Science.gov (United States)

    Moberly, C. L.

    1967-01-01

    Miniature solid state phase detector using MOSFETs is used in a phase lock loop with a sun-bit detector in an integrated data-link circuit. This replaces bulky transformer circuits. It uses an inverter amplifier, a modulator switch, and a buffer amplifier.

  17. N-Acyliminium Intermediates in Solid-Phase Synthesis

    DEFF Research Database (Denmark)

    Quement, Sebastian Thordal le; Petersen, Rico; Meldal, M.; Nielsen, Thomas Eiland

    2010-01-01

    N-Acyliminium ions are powerful intermediates in synthetic organic chemistry. Examples of their use are numerous in solution-phase synthesis, but there are unmerited few reports on these highly reactive electrophiles in solid-phase synthesis. The present review covers the literature to date and...

  18. Solid-Phase Products of Bacterial Oxidation of Arsenical Pyrite

    OpenAIRE

    Carlson, Liisa; Lindström, E. Börje; Hallberg, Kevin B.; Tuovinen, Olli H.

    1992-01-01

    Bacterial leaching of an As-containing pyrite concentrate produced acidic (pH < 1) leachates. During the leaching, the bacteria solubilized both As and Fe, and these two elements were distributed in solution-phase and solid-phase products. Jarosite and scorodite were the exclusive crystalline products in precipitate samples from the bacterial leaching of the sulfide concentrate.

  19. Heterogeneous Ferroelectric Solid Solutions Phases and Domain States

    CERN Document Server

    Topolov, Vitaly

    2012-01-01

    The book deals with perovskite-type ferroelectric solid solutions for modern materials science and applications, solving problems of complicated heterophase/domain structures near the morphotropic phase boundary and applications to various systems with morphotropic phases. In this book domain state–interface diagrams are presented for the interpretation of heterophase states in perovskite-type ferroelectric solid solutions. It allows to describe the stress relief in the presence of polydomain phases, the behavior of unit-cell parameters of coexisting phases and the effect of external electric fields. The novelty of the book consists in (i) the first systematization of data about heterophase states and their evolution in ferroelectric solid solutions (ii) the general interpretation of heterophase and domain structures at changing temperature, composition or electric field (iii) the complete analysis of interconnection domain structures, unit-cell parameters changes, heterophase structures and stress relief.

  20. Electron-solid and electron-liquid phases in graphene

    Science.gov (United States)

    Knoester, M. E.; Papić, Z.; Morais Smith, C.

    2016-04-01

    We investigate the competition between electron-solid and quantum-liquid phases in graphene, which arise in partially filled Landau levels. The differences in the wave function describing the electrons in the presence of a perpendicular magnetic field in graphene with respect to the conventional semiconductors, such as GaAs, can be captured in a form factor which carries the Landau-level index. This leads to a quantitative difference in the electron-solid and -liquid energies. For the lowest Landau level, there is no difference in the wave function of relativistic and nonrelativistic systems. We compute the cohesive energy of the solid phase analytically using a Hartree-Fock Hamiltonian. The liquid energies are computed analytically as well as numerically, using exact diagonalization. We find that the liquid phase dominates in the n =1 Landau level, whereas the Wigner crystal and electron-bubble phases become more prominent in the n =2 and 3 Landau level.

  1. Biogasification of solid wastes by two-phase anaerobic fermentation

    International Nuclear Information System (INIS)

    Municipal, industrial and agricultural solid wastes, and biomass deposits, cause large-scale pollution of land and water. Gaseous products of waste decomposition pollute the air and contribute to global warming. This paper describes the development of a two-phase fermentation system that alleviates methanogenic inhibition encountered with high-solids feed, accelerates methane fermentation of the solid bed, and captures methane (renewable energy) for captive use to reduce global warming. The innovative system consisted of a solid bed reactor packed with simulated solid waste at a density of 160 kg/m3 and operated with recirculation of the percolated culture (bioleachate) through the bed. A rapid onset of solids hydrolysis, acidification, denitrification and hydrogen gas formation was observed under these operating conditions. However, these fermentative reactions stopped at a total fatty acids concentration of 13,000 mg/l (as acetic) at pH 5, with a reactor head-gas composition of 75 percent carbon dioxide, 20 percent nitrogen, 2 percent hydrogen and 3 percent methane. Fermentation inhibition was alleviated by moving the bioleachate to a separate methane-phase fermenter, and recycling methanogenic effluents at pH 7 to the solid bed. Coupled operation of the two reactors promoted methanogenic conversion of the high-solids feed. (author)

  2. Solid state photomultiplier for astronomy, phase 2

    Science.gov (United States)

    Besser, P. J.; Hays, K. M.; Laviolette, R. A.

    1989-01-01

    Epitaxial layers with varying donor concentration profiles were grown on silicon substrate wafers using chemical vapor deposition (CVD) techniques, and solid state photomultiplier (SSPM) devices were fabricated from the wafers. Representative detectors were tested in a low background photon flux, low temperature environment to determine the device characteristics for comparison to NASA goals for astronomical applications. The SSPM temperatures varied between 6 and 11 K with background fluxes in the range from less than 5 x 10 to the 6th power to 10 to the 13th power photons/square cm per second at wavelengths of 3.2 and 20 cm. Measured parameters included quantum efficiency, dark count rate and bias current. Temperature for optimal performance is 10 K, the highest ever obtained for SSPMs. The devices exhibit a combination of the lowest dark current and highest quantum efficiency yet achieved. Experimental data were reduced, analyzed and used to generate recommendations for future studies. The background and present status of the microscopic theory of SSPM operation were reviewed and summarized. Present emphasis is on modeling of the avalanche process which is the basis for SSPM operation. Approaches to the solution of the Boltzmann transport equation are described and the treatment of electron scattering mechanisms is presented. The microscopic single-electron transport theory is ready to be implemented for large-scale computations.

  3. Flow immunoassay using solid-phase entrapment.

    Science.gov (United States)

    Locascio-Brown, L; Martynova, L; Christensen, R G; Horvai, G

    1996-05-01

    A flow injection immunoassay was performed using a column packed with reversed-phase sorbents to effect separation of the immunoreacted species by entrapping free analyte and allowing antibody-conjugated analyte to pass unretained. Fluorescein-labeled analyte was measured in a competitive assay for the anticonvulsant drug phenytoin. The simplicity of the assay was the greatest advantage of the technique, which allowed for measurement of phenytoin in a 2-min assay time. The reliable detection limit for the assay was 5 nmol L(-)(1) of phenytoin in serum. The columns were regenerated with periodic injections of ethanol solutions to remove the entrapped analyte and prepare the column for subsequent analyses. PMID:21619134

  4. Linkage of biomolecules to solid phases for immunoassay

    International Nuclear Information System (INIS)

    Topics covered by this lecture include a brief review of the principal methods of linkage of biomolecules to solid phase matrices. Copies of the key self explanatory slides are presented as figures together with reprints of two publications by the author dealing with a preferred chemistry for the covalent linkage of antibodies to hydroxyl and amino functional groups and the effects of changes in solid phase matrix and antibody coupling chemistry on the performance of a typical excess reagent immunoassay for thyroid stimulating hormone

  5. SOLID PHASE TRANSITION OF SYNDIOTACTIC POLYSTYRENE IN SUPERCRITICAL CO2

    Institute of Scientific and Technical Information of China (English)

    Yu-ying Li; Jia-song He

    2002-01-01

    Solid phase transition of the a form crystals to the β form crystals in syndiotactic polystyrene (sPS) samples has occurred in supercritical CO2. This transformation is different from those detected under other conditions. The effects of some factors (e.g. time, temperature, and pressure) on the solid phase transformation of sPS in supercritical CO2 were analyzed in detail. Experimental results show that longer time, higher temperature or higher pressure favors the transformation of the α form crystals to the β form crystals.

  6. Rigid polar composite supports for use in solid phase synthesis

    International Nuclear Information System (INIS)

    A number of particulate polyethylene and polypropylene based matrices have been γ-radiation grafted with poly(acryloylsarcosine methyl ester). The resulting composite materials have physicochemical properties attractive for use in continuous solid phase synthesis. Three macroporous polystyrene resins have also been impregnated with a secondary polyamide network using thermal initiation. All of these retain their rigid spherical structure and the composite properties again make them good candidates for use under pressure. One of these has been used in a preliminary solid phase experiment and two successive amino acid residues coupled with approx. 100% yield. 1 figure, 2 tables

  7. [Studies on the anaerobic phased solid digester system for municipal solid waste (MSW) treatment].

    Science.gov (United States)

    Wang, Jun-qin; Shen, Dong-sheng

    2004-05-01

    Through analyzing and detecting the leaching pollutant (COD) in two bioreactors, anaerobic phased solid digester system and leachate direct-recirculating landfill, the changing rule of municipal solid waste and the characteristics of methanogenesis were studied. The results showed that anaerobic phased solid digester system accelerated the process of degrading municipal solid waste and stabilizing landfill site. The relationship between the leaching pollutant (COD) and refuse age was logarithmic linear correlation. More than 80% of biogas in volume occured in the methanogenisis bioreactor, the methane content in which was 55%-69%. The preferable volumetric COD loading rate of the methanogenisis bioreactor was 6.5-7.5 g/(L x d). PMID:15327275

  8. Preconcentration of strontium by micelle modified solid phase extraction

    International Nuclear Information System (INIS)

    The preconcentration of strontium using a solid phase separation technique with selective micelle forming complexant has been studied. Di-2-ethylhexylphosphoric acid and its thio- and dithio derivatives were used as modifiers. The goal of this work was to study the influence of physico-chemical parameters on recovery of strontium after its preconcentration on reverse phase (Si-C-18) using micelle modifiers. (author) 5 refs.; 7 figs

  9. Antibody coated tubes in T3 - solid phase radioimmunoassay

    International Nuclear Information System (INIS)

    The aim of this study was to develop a simple and inexpensive form of solid phase radioimmunoassay of T3 (3,5,3'-L- triiodothyronine); for the preparation of solid phase, the adsorption of anti-T3 antibodies to polystyrene tubes has been used. The polystyrene tubes were used without washing or other treatment; each tube was coated by addition of an uniform volume (175 μl) of diluted antiserum of moderately high titer. Antiserum dilution was 1:3000 and the optimal pH of buffer solution was 8.4 - 8.6. The best results were achieved with an exposure time to antiserum of 40 h at 4 deg C. The antibody - coated tubes prepared in this way were verified by using them to the radioimmunoassay of T3. The results obtained with the above mentioned solid phase in T3-RIA of three level control serums were found to be successful for setting up T3- solid phase radioimmunoassay of high precision. (authors)

  10. Solid phase separation technique for use in radioimmunoassays

    International Nuclear Information System (INIS)

    A radioimmunoassay procedure, and article of manufacture for carrying out that procedure, are disclosed herein. The solid phase separation technique utilized in the radioimmunoassay of this invention utilizes a test tube, the internal surface of which has been coated with two antibody layers

  11. Solid-phase synthesis of 3-amino-2-pyrazolines

    DEFF Research Database (Denmark)

    Lyngsø, Lars O.; Nielsen, John

    1998-01-01

    The development of a solid-phase synthesis of 3-amino-2-pyrazolines is described. Conjugate addition of hydrazines to α,β-unsaturated nitriles followed by cyclization yields 3-amino-2-pyrazolines. Acylation or sulfonation of the free amino-group yields a 24 member library of 3-amino-2- pyrazolines....

  12. Combinatorial solid-phase synthesis of hapalosin mimetics

    DEFF Research Database (Denmark)

    Olsen, Jacob A.; Jensen, Knud J.; Nielsen, John

    2000-01-01

    The solid-phase synthesis of a small library of mimetics of the cyclic depsipeptide hapalosin is described. 3-Amino-4-hydroxy-5-nitrobenzoic acid was anchored through the anilino moiety to a backbone amide linker (BAL) handle support. Using chemoselective reactions and without the need for...

  13. Solid-phase-supported synthesis of morpholinoglycine oligonucleotide mimics

    Directory of Open Access Journals (Sweden)

    Tatyana V. Abramova

    2014-05-01

    Full Text Available An efficient solid-phase-supported peptide synthesis (SPPS of morpholinoglycine oligonucleotide (MorGly mimics has been developed. The proposed strategy includes a novel specially designed labile linker group containing the oxalyl residue and the 2-aminomethylmorpholino nucleoside analogues as first subunits.

  14. Solid Phase Characterization of Tank 241-C-105 Grab Samples

    International Nuclear Information System (INIS)

    The solid phase characterization (SPC) of three grab samples from single-shell Tank 241-C-105 (C-105) that were received at the laboratory the week of October 26, 2015, has been completed. The three samples were received and broken down in the 11A hot cells.

  15. Binding of properdin to solid-phase immune complexes

    DEFF Research Database (Denmark)

    Junker, A; Baatrup, G; Svehag, S E; Wang, P; Holmström, E; Sturfelt, G; Sjöholm, A G

    1998-01-01

    The capacity of serum to support deposition of C3, properdin and factor B was studied by enzyme-linked immunosorbent assay using solid-phase immune complexes (IC) for activation of complement. Deposition of C3 and properdin occurred in fairly dilute normal human serum (NHS), but factor B uptake w...

  16. Solid Phase Characterization of Tank 241-C-105 Grab Samples

    Energy Technology Data Exchange (ETDEWEB)

    Ely, T. M. [Washington River Protection Solutions LLC, Richland, WA (United States); LaMothe, M. E. [Washington River Protection Solutions LLC, Richland, WA (United States); Lachut, J. S. [Washington River Protection Solutions LLC, Richland, WA (United States)

    2016-01-11

    The solid phase characterization (SPC) of three grab samples from single-shell Tank 241-C-105 (C-105) that were received at the laboratory the week of October 26, 2015, has been completed. The three samples were received and broken down in the 11A hot cells.

  17. Solid-phase synthesis of complex and pharmacologically interesting heterocycles

    DEFF Research Database (Denmark)

    Nielsen, Thomas Eiland

    2009-01-01

    Efficient routes for the creation of heterocycles continue to be one of the primary goals for solid-phase synthesis. Recent advances in this field rely most notably on transition-metal-catalysis and N-acyliminium chemistry to mediate a range of cyclization processes for the generation of compounds...

  18. Solid-phase synthesis of 3-amino-2-pyrazolines

    DEFF Research Database (Denmark)

    Nielsen, John

    1998-01-01

    The development of a solid-phase synthesis of 3-amino-2-pyrazolines is described. Conjugate addition of hydrazines to alpha,beta-unsaturated nitriles followed by cyclization yields 3-amino-2-pyrazolines. Acylation or sulfonation of the free amino-group yields a 24 member library of 3-amino-2-pyra...

  19. The solid phase of ginkgolide K: Structure and physicochemical properties

    Science.gov (United States)

    Zhang, Yiwen; Zhang, Guoshun; Wang, Zhenzhong; Lv, Yang; Xiao, Wei

    2016-05-01

    Four solvates of ginkgolide K with dimethyl sulfoxide(I), water molecule(II), acetone-isopropyl alcohol(III), methanol-ethanol(IV) and one solvate-free (V) have been described in this work. And the solid-state techniques such as X-ray diffraction, thermal analysis and Fourier transform infrared spectroscopy were used for characterization of the solid phases. The single crystal structures of ginkgolide K solvates (I-IV) have been determined. Ginkgolide K shows strong inflexibility and solvents being incorporated in the crystal structure results in it forming polymorphs via the diverse hydrogen bond interactions.

  20. Qinshan phase Ⅱ expansion project to minimize solid waste transformation

    International Nuclear Information System (INIS)

    The nuclear power plant in the production and maintenance period usually have a certain amount of radioactive waste, according to the physical state of these wastes, it can be divided into radioactive waste gas, radioactive waste water and solid waste. Radioactive waste gas and water, treated by the waste treatment system, and the corresponding facilities for filtration, purification. compression, storage to meet discharging requirements, discharge to the environment finally. As for solid radioactive waste, common solution in nuclear power plants is to use specially formulated cement to cure and packaged into the barrel, stored in a particular building for naturally decaying. Qinshan NPP have optimized the solid waste treatment process m extension project. As the nuclear power industry prospering, radioactive solid waste generation would increased dramatically,. how to reduce solid waste production volume, how to control the volume of waste bins will become serious issues in future. Qinshan Phase Ⅱ expansion project as 'replica plus improvement' projects, 'solid waste minimization transformation' has received great attention from SEPA (State Environmental Protection Department). (authors)

  1. Modeling of liquid phase formation by solid-solid interaction of Zircaloy and AISI 316 Steel

    International Nuclear Information System (INIS)

    Two models were developed in order to describe the eutectic interaction between Zircaloy-4 and AISI 316 stainless steel, in the temperature range 1000 - 1300 C degree. The aim of the models is to simulate what could happen in the nucleus of a power reactor in an eventual transient high temperature accident. Entry data correspond to the instantaneous positions of the Zircaloy-4 / liquid and stainless steel / liquid inter phases, obtained from experimental data. The hypothesis corresponding to the first model are: that the liquid phase growths by diffusion of the main elements of each alloy in the liquid (Fe and Zr), that there is no interaction between these elements during diffusion, that the diffusion or convection in the solid state is not considered, and that volume changes are negligible during fusion and interdiffusion. Concentrations at the solid/liquid inter phases and the effective diffusion coefficients for Zr and Fe in the liquid can be obtained. The model allows to calculate the formation kinetics for the liquid phase as measured by Zr oxide layers of 0, 10, 20 and 50 microns initial width, formed on the Zircaloy in order to simulate the operating conditions of a reactor. Incubation times for the onset of the reaction, observed experimentally in pre-oxidized samples, were calculated taking into account the oxide dissolution. The second model considers diffusion of Fe in Zircaloy since Fe is a fast diffuser in Zr. As in the first model, concentrations at the solid/liquid inter phases as well as the effective diffusion coefficients for Fe and Zr in the liquid, are calculated. The results obtained in this case depend on the Fe concentration at the solid/liquid interphase at the solid Zircaloy side, and on the Fe diffusivity in Zircaloy-4, which was estimated by the Fe diffusivity in Zr. (author)

  2. Entransy dissipation minimization for liquid-solid phase change processes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The liquid-solid phase change process of a simple one-dimensional slab is studied in this paper.By taking entransy dissipation minimization as optimization objective,the optimal external reservoir temperature profiles are derived by using optimal control theory under the condition of a fixed freezing or melting time.The entransy dissipation corresponding to the optimal heat exchange strategies of minimum entransy dissipation is 8/9 of that corresponding to constant reservoir temperature operations,which is independent of all system parameters.The obtained results for entransy dissipation minimization are also compared with those obtained for the optimal heat exchange strategies of minimum entropy generation and constant reservoir temperature operations by numerical examples.The obtained results can provide some theoretical guidelines for the choice of optimal cooling or heating strategy in practical liquid-solid phase change processes.

  3. Studies in Solid Phase Peptide Synthesis: A Personal Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, A R

    2007-06-01

    By the early 1970s it had became apparent that the solid phase synthesis of ribonuclease A could not be generalized. Consequently, virtually every aspect of solid phase peptide synthesis (SPPS) was reexamined and improved during the decade of the 1970s. The sensitive detection and elimination of possible side reactions (amino acid insertion, N{sup {alpha}}-trifluoroacetylation, N{sup {alpha}{var_epsilon}}-alkylation) was examined. The quantitation of coupling efficiency in SPPS as a function of chain length was studied. A new and improved support for SPPS, the 'PAM-resin', was prepared and evaluated. These and many other studies from the Merrifield laboratory and elsewhere increased the general acceptance of SPPS leading to the 1984 Nobel Prize in Chemistry for Bruce Merrifield.

  4. On the nature of phase transition in solid electrolytes

    International Nuclear Information System (INIS)

    An attempt is made to precisely measure the solid electrolyte RbAg4I5 conductivity in the vicinity of the phase transition at 208 deg K. Polycrystalline samples obtained by common technique have been used as well as single RbAg4I5 crystals grown from the acetone solution of AgI and RbI. The dependence of conductivity on inverse temperature is given for different samples. The phase transition of the single crystals is accompanied by a jump (approximately 12%) of conductivity. This transfer is reversible, since no hysteresis is found in the +-0.3 deg K vicinity of the phase transition temperature. Polycrystalline samples display no pronounces jump of conductivity, but the conductivity curve has two bends, i.e. the phase transition is ''diffused''. The activation energy before the transition differs from that after the transition

  5. A solid-phase radioimmunoassay for detection of tetanus antibodies

    International Nuclear Information System (INIS)

    A solid-phase radioimmunoassay has been developed as a screening technique for tetanus antibodies in blood plasma. It is based on the principle of a commercial test for Hepatitis B antibody. Compared to previous screening techniques, the radioimmunoassay showed better stability with no apparent loss of sensitivity over a 2 month period. This technique has proved useful in determining tetanus immunity and in monitoring free antibody level in treated cases of clinical tetanus. (U.K.)

  6. Numerical studies of integrated concrete with a solid-solid phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, D.; Fung, A.S.; Siddiqui, O. [Ryerson Polytechnic Univ., Toronto, ON (Canada). Dept. of Mechanical and Industrial Engineering

    2007-07-01

    The thermal storage performance of concrete cement integrated with a hypothetical solid-solid phase change material (PCM) was investigated. The thermal storage material was exposed to solar radiation on a sunny winter day in Toronto. The effects of weight ratio of PCM to cement and the thickness of cement were studied. The integrated PCM cement compound was treated as a homogenous mixture with uniform physical and thermal properties. Finite element modelling (FEM) was used to determine the effective heat capacity method. Governing equations for the heat transfer process in the solid-liquid PCMs included Navier-Stokes equations; mass conservation equations; and the energy conservation equation. The energy equation was the only governing equation for the binary solid state PCMs. The enthalpy method was used to apply governing equations of PCMs over the whole fixed domain of interest. The total energy required for the phase change was determined using the enthalpy function. The simulations showed that PCMs can reduce the fluctuation of temperature. Temperature fluctuations on the upper surface varied mainly in amplitude and in time phase due to thermal storage effects. The total amount of solar gain increased when the PCM ratio increased. However, the effect of the PCM ratio on the amount of released energy became less apparent when the thickness of the PCM was increased. It was concluded that a 30 per cent PCM ratio contributed the maximum overall released energy after the radiation gain vanished. 8 refs., 3 tabs., 11 figs.

  7. Phase field modeling and simulation of three-phase flow on solid surfaces

    Science.gov (United States)

    Zhang, Qian; Wang, Xiao-Ping

    2016-08-01

    Phase field models are widely used to describe the two-phase system. The evolution of the phase field variables is usually driven by the gradient flow of a total free energy functional. The generalization of the approach to an N phase (N ≥ 3) system requires some extra consistency conditions on the free energy functional in order for the model to give physically relevant results. A projection approach is proposed for the derivation of a consistent free energy functional for the three-phase Cahn-Hilliard equations. The system is then coupled with the Navier-Stokes equations to describe the three-phase flow on solid surfaces with moving contact line. An energy stable scheme is developed for the three-phase flow system. The discrete energy law of the numerical scheme is proved which ensures the stability of the scheme. We also show some numerical results for the dynamics of triple junctions and four phase contact lines.

  8. Solid-Phase Preparation and Characterization of Chitosan

    Institute of Scientific and Technical Information of China (English)

    GaoLe-ping; DuYu-min; ZhangDao-bin; ShiXiao-wen; ZhanHuai-yu; SongWen-hua

    2003-01-01

    Chitosan was prepared with stressing method by blending chitin and solid alkali in a single-screw extruder at given temperature and characterized by potentiometric titration, gel permeation chromatography (GPC), infrared spectrum (IR) and carborr13 magnetic resonance sperctroscopy (13C NMR). Chitosan with a deacetylation degree (DD) of 76. 1% was obtained at a mass ratio 0.2 : 1 : 1 for H20/chitin/NaOH at 160℃ for 12 mirL Compared to conventional solution method(usually 1 : 10 for chitin/NaOH), the alkali assumption greatly decreased. Molecular weight of chitosan obtained by solid-phase method(S3,M. 1.54 X 10s ) was lower than that obtained by suspension method(Y2,Mw3. 34×105). During deacetylation, molecular weight decreased with high reaction temperature and long reaction time but remained same at different initial ratios of NaOH/chitirL It might be concluded that degradation of chitosan was caused by breakout of the main chain of the oxidized chitosan catalyzed by alkali during the deactylation. IR and 13C NMR showed that structures of chitosans prepared by solid-phase method were not changed.

  9. Solid-phase catalytic reactions of tritium with carbohydrates. Communication 3. Mechanism of isomerization of epimeric pentoses in the course of solid-phase catalytic hydrogenation with tritium

    International Nuclear Information System (INIS)

    The mechanism of isomerization of ribose into arabinose in the solid phase under the action of spillover hydrogen in the course of solid-phase catalytic hydrogenation with tritium was studied. Isomerization of ribose was shown to occur by a complex mechanism similar to acid-catalyzed keto-enol tautomerization of epimeric sugars in solution; the active species in solid-phase catalytic hydrogenation of D-ribose with tritium is spillover hydrogen in the proton form

  10. Heat transfer in different phases of solid cyclohexene

    Science.gov (United States)

    Konstantinov, V. A.; Krivchikov, A. I.; Korolyuk, O. A.; Revyakin, V. P.; Sagan, V. V.; Vdovichenko, G. A.; Zvonaryova, A. V.

    2013-09-01

    The thermal conductivity of solid cyclohexene C6H10 has been measured in two independent experiments in five different stable and metastable phase states: orientational glass (Ig), orientational glass (IIIg) with a partial order, dynamically orientationally disordered state (III) with a partial order, completely orientationally ordered phase (II) and “plastic” phase (I). The measurements were carried out at saturated vapor pressure in the temperature range 2-120 K and at isochoric conditions in “plastic” and orientationally ordered phases on samples of different densities. The isochoric thermal conductivity of “plastic” phase increases smoothly with temperature. It can be attributed to weakening of the translational orientational coupling which, in turn, leads to a decrease in phonon scattering on rotational excitations. The thermal conductivity of cyclohexene measured at saturated vapor pressure exhibits a similar behavior in phases Ig, IIIg, and II. At low temperatures (Tthermal conductivity tends to T2 dependence, passes through a maximum and decreases further with increasing temperature following the dependence, which is somewhat different from 1/T. It was found that the thermal conductivity can be represented as a sum of two contributions κ(T)=κ1(T)+κ2(T), where κ1(T) is due to propagating phonons whose mean-free path exceeds half the phonon wavelength, and κ2(T) is attributed to localized short-wavelength or “diffusive” vibrational modes.

  11. Solid phase extraction of petroleum carboxylic acids using a functionalized alumina as stationary phase.

    Science.gov (United States)

    de Conto, Juliana Faccin; Nascimento, Juciara dos Santos; de Souza, Driele Maiara Borges; da Costa, Luiz Pereira; Egues, Silvia Maria da Silva; Freitas, Lisiane Dos Santos; Benvenutti, Edilson Valmir

    2012-04-01

    Petroleum essentially consists of a mixture of organic compounds, mainly containing carbon and hydrogen, and, in minor quantities, compounds with nitrogen, sulphur, and oxygen. Some of these compounds, such as naphthenic acids, can cause corrosion in pipes and equipment used in processing plants. Considering that the methods of separation or clean up the target compounds in low concentrations and in complex matrix use large amounts of solvents or stationary phases, is necessary to study new methodologies that consume smaller amounts of solvent and stationary phases to identify the acid components present in complex matrix, such as crude oil samples. The proposed study aimed to recover acid compounds using the solid phase extraction method, employing different types of commercial stationary ion exchange phases (SAX and NH(2)) and new phase alumina functionalized with 1,4-bis(n-propyl)diazoniabicyclo[2.2.2]octane chloride silsesquioxane (Dab-Al(2)O(3)), synthesized in this work. Carboxylic acids were used as standard mixture in the solid phase extraction for further calculation of recovery yield. Then, the real sample (petroleum) was fractionated into saturates, aromatics, resins, and asphaltenes, and the resin fraction of petroleum (B1) was eluted through stationary ion exchange phases. The stationary phase synthesized in this work showed an efficiency of ion exchange comparable to that of the commercial stationary phases. PMID:22589166

  12. Solid-phase fluorescence spectroscopy to characterize organic wastes.

    Science.gov (United States)

    Muller, Mathieu; Milori, Débora Marcondes Bastos Pereira; Déléris, Stéphane; Steyer, Jean-Philippe; Dudal, Yves

    2011-01-01

    The production of solid organic waste (SOW) such as sewage sludge (SS) or municipal solid waste (MSW) has been continuously increasing in Europe since the beginning of the 1990'. Today, the European Union encourages the stabilization of these wastes using biologic processes such as anaerobic digestion and/or composting to produce bio-energy and organic fertilizers. However, the design and management of such biologic processes require knowledge about the quantity and quality of the organic matter (OM) contained in the SOW. The current methods to characterize SOW are tedious, time-consuming and often insufficiently informative. In this paper, we assess the potential of solid-phase fluorescence (SPF) spectroscopy to quickly provide a relevant characterization of SOW. First, we tested well known model compounds (tryptophan, bovine serum albumin, lignin and humic acid) and biologic matrix (Escherichia coli) in three dimensional solid-phase fluorescence (3D-SPF) spectroscopy. We recorded fluorescence spectra from proteinaceous samples but we could not record the fluorescence emitted by lignin and humic acid powders. For SOW samples, fluorescence spectra were successfully recorded for MSW and most of its sub-components (foods, cardboard) but impossible for SS, sludge compost (SC) and ligno-cellulosic wastes. Based on visual observations and additional assays, we concluded that the presence of highly light-absorptive chemical structures in such dark-colored samples was responsible for this limitation. For such samples, i.e. lignin, humic acid, SS, SC and ligno-cellulosic wastes, we show that laser induced fluorescence (LIF) spectroscopy enables the acquisition of 2D fluorescence spectra. PMID:21696938

  13. Novel solidsolid phase change material based on polyethylene glycol and cellulose used for temperature stabilisation

    Directory of Open Access Journals (Sweden)

    Wojda Marta

    2014-01-01

    Full Text Available Thermal management is one of crucial issues in the development of modern electronic devices. In the recent years interest in phase change materials (PCMs as alternative cooling possibility has increased significantly. Preliminary results concerning the research into possibility of the use of solid-solid phase change materials (S-S PCMs for stabilisation temperature of electronic devices has been presented in the paper. Novel solid-solid phase change material based on polyethylene glycol and cellulose has been synthesized. Attempt to improve its thermal conductivity has been taken. Material has been synthesized for the purpose of stabilisation of temperature of electronic devices.

  14. Kinetics of (beta)(right arrow)(delta) Solid-Solid Phase Transition of HMX

    International Nuclear Information System (INIS)

    In order to calculate the kinetic parameters from DSC data, we have used the generally accepted methods of Bershtein [13]. We have calculated the rate constants for 4 temperatures and the activation energy based on the shift in the transition temperature, β → (delta) for HMX. The values of Ea from this work is 402 kJ/mol compared to previous results by Brill [9] of 204 kJ/mol. Brill and associates measured the phase transition of HMX using FTIR, sodium chloride plates and silicon oil. Given the differences in technique between FTIR and DSC the results found in this work are reasonable. In this investigation a large sample set (16) proved to be statistically valid for the determinations of k. Linear regressions were performed, observed and good fits were obtained, for each temperature. The enthalpy determination of ΔHo, for the β → (delta) phase transition was reproducible with in 3 parts in 100 over the range of this experiment. Thus, the data derived from this experiment k, Ea, and ΔHo are valid parameters for the solid-solid phase transition. Obtaining pure β phase HMX was very important for this investigation. Related to the phase change is the particle size distribution and is presented in Figure 3. Compared to previous work on HMX, this study utilized very pure β phase material. In addition, the particle size was controlled more rigorously at about 160 (micro)m, giving a more consistent result for α. Thus, these kinetic results should have less scatter than results with less control of HMX purity and particle size. The kinetic basis of the polymorphic conversion is due to the cohesive forces in the HMX crystal lattice [21]. The energy required to bring about change from chair to chair-chair conformation has been reported by Brill [21] as ring torsion and is essentially a normal mode of the molecule that requires about 4 kJ mol-1. For the purpose of this investigation the energy of activation found in this work relates to the disruption of the

  15. Liquid/solid/dual phase xenon γ-ray detectors

    International Nuclear Information System (INIS)

    It is recognized by various groups in the world that liquid xenon (LXe) is an interesting medium for the detection of γ-rays. In spite of all the experimental and theoretical effort expended during recent years, the processes that take place in this medium are not yet fully understood. We have obtained some preliminary results using an ionization chamber with a Frisch grid. This chamber could be filled with LXe and with solid xenon (SXe). We also investigated dual phase (GXe/SXe) systems. Our study will be continued with a newly developed detection cell described in this article. ((orig.))

  16. Liquid/solid/dual phase xenon γ-ray detectors

    Science.gov (United States)

    van Sonsbeek, R.; Bom, V. R.; van Eijk, C. W. E.; Hollander, R. W.; Meijvogel, K.; Okx, W. J. C.

    1994-09-01

    It is recognized by various groups in the world that liquid xenon (LXe) is an interesting medium for the detection of γ-rays. In spite of all the experimental and theoretical effort expended during recent years, the processes that take place in this medium are not yet fully understood. We have obtained some preliminary results using an ionization chamber with a Frisch grid. This chamber could be filled with LXe and with solid xenon (SXe). We also investigated dual phase (GXe/SXe) systems. Our study will be continued with a newly developed detection cell described in this article.

  17. Solid phase speciation of radiocaesium in bottom sediments

    International Nuclear Information System (INIS)

    A comprehensive laboratory study is presented on the solid-phase speciation of ionic radiocaesium in bottom sediments (riverine, lacustrine, estuarine) covering some 75 samples of widely differing textural properties and originating from various locations in Europe. Sediments are characterised in terms of cation exchange capacities, exchangeable potassium and ammonium and specific radiocaesium sorption properties. It is shown that radiocaesium is quantitatively retained in the specific sorption sites associated with the micaceous clay minerals in the sediments. The practical consequences of this finding are discussed in terms of a predictive equation allowing forecasting of radiocaesium levels in the watercolumn or in the interstitial fluid of the sediment

  18. Development of SBS-phase conjugation mirror in solid media

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Hidetsugu; Fujita, Hisanori; Nakatsuka, Masahiro [Osaka Univ., Suita (Japan). Inst. of Laser Engineering

    2000-03-01

    An optical fiber offers a low power SBS threshold and stable performance at input energies of a few mJ level. For long pulse duration using a longer focusing lens, fused-silica glass had high SBS reflectivity over 90% without any damage occurrence at the incident energy of 380 mJ in 15-ns pulse duration. These properties of the fused-silica are almost comparable with those of highly performed gases or liquids. Damage-free operation using a fused-silica as a better phase conjugation material would lead to construct more compact laser-diode pumped all-solid-state laser system. (author)

  19. Development of SBS-phase conjugation mirror in solid media

    International Nuclear Information System (INIS)

    An optical fiber offers a low power SBS threshold and stable performance at input energies of a few mJ level. For long pulse duration using a longer focusing lens, fused-silica glass had high SBS reflectivity over 90% without any damage occurrence at the incident energy of 380 mJ in 15-ns pulse duration. These properties of the fused-silica are almost comparable with those of highly performed gases or liquids. Damage-free operation using a fused-silica as a better phase conjugation material would lead to construct more compact laser-diode pumped all-solid-state laser system. (author)

  20. Solid-phase synthesis of polyamine toxin analogues

    DEFF Research Database (Denmark)

    Kromann, Hasse; Krikstolaityte, Sonata; Andersen, Anne J; Andersen, Kim; Krogsgaard-Larsen, Povl; Jaroszewski, Jerzy W; Egebjerg, Jan; Strømgaard, Kristian

    2002-01-01

    receptors, in particular Ca(2+)-permeable AMPA and kainate receptors. We have previously shown that an analogue of PhTX-433 with one of the amino groups replaced by a methylene group, philanthotoxin-83 (PhTX-83) is a selective and potent antagonist of AMPA receptors. We now describe the solid-phase...... synthesis of analogues of PhTX-83 and the electrophysiological characterization of these analogues on cloned AMPA and kainate receptors. The polyamine portion of PhTX-83 was modified systematically by changing the position of the secondary amino group along the polyamine chain. In another series of...

  1. Sensitive and fast mutation detection by solid phase chemical cleavage

    DEFF Research Database (Denmark)

    Hansen, Lise Lotte; Justesen, Just; Kruse, Torben A

    1996-01-01

    We have developed a solid phase chemical cleavage method (SpCCM) for screening large DNA fragments for mutations. All reactions can be carried out in microtiterwells from the first amplification of the patient (or test) DNA through the search for mutations. The reaction time is significantly...... reduced compared to the conventional chemical cleavage method (CCM), and even by using a uniformly labelled probe, the exact position and nature of the mutation can be revealed. The SpCCM is suitable for automatization using a workstation to carry out the reactions and a fluorescent detection-based DNA...

  2. Advances in solid-phase extraction disks for environmental chemistry

    Science.gov (United States)

    Thurman, E.M.; Snavely, K.

    2000-01-01

    The development of solid-phase extraction (SPE) for environmental chemistry has progressed significantly over the last decade to include a number of new sorbents and new approaches to SPE. One SPE approach in particular, the SPE disk, has greatly reduced or eliminated the use of chlorinated solvents for the analysis of trace organic compounds. This article discusses the use and applicability of various SPE disks, including micro-sized disks, prior to gas chromatography-mass spectrometry for the analysis of trace organic compounds in water. Copyright (C) 2000 Elsevier Science B.V.

  3. A rapid solution-phase screening technique for hybridoma culture supernatants using radiolabeled antigen and a solid-phase immunoadsorbent

    International Nuclear Information System (INIS)

    The solid-phase immunoassay commonly used to screen hybridoma supernatants at times gave falsely positive results. A solution-phase screening technique, which uses radiolabeled antigen and a solid-phase immunoadsorbent, is described. This technique overcomes the problem of false positives and can be easily adopted for other soluble antigens. (Auth.)

  4. Powder metallurgy: Solid and liquid phase sintering of copper

    Science.gov (United States)

    Sheldon, Rex; Weiser, Martin W.

    1993-01-01

    Basic powder metallurgy (P/M) principles and techniques are presented in this laboratory experiment. A copper based system is used since it is relatively easy to work with and is commercially important. In addition to standard solid state sintering, small quantities of low melting metals such as tin, zinc, lead, and aluminum can be added to demonstrate liquid phase sintering and alloy formation. The Taguchi Method of experimental design was used to study the effect of particle size, pressing force, sintering temperature, and sintering time. These parameters can be easily changed to incorporate liquid phase sintering effects and some guidelines for such substitutions are presented. The experiment is typically carried out over a period of three weeks.

  5. Studies of phase transitions in the aripiprazole solid dosage form.

    Science.gov (United States)

    Łaszcz, Marta; Witkowska, Anna

    2016-01-01

    Studies of the phase transitions in an active substance contained in a solid dosage form are very complicated but essential, especially if an active substance is classified as a BCS Class IV drug. The purpose of this work was the development of sensitive methods for the detection of the phase transitions in the aripiprazole tablets containing initially its form III. Aripiprazole exhibits polymorphism and pseudopolymorphism. Powder diffraction, Raman spectroscopy and differential scanning calorimetry methods were developed for the detection of the polymorphic transition between forms III and I as well as the phase transition of form III into aripiprazole monohydrate in tablets. The study involved the initial 10 mg and 30 mg tablets, as well as those stored in Al/Al blisters, a triplex blister pack and HDPE bottles (with and without desiccant) under accelerated and long term conditions. The polymorphic transition was not observed in the initial and stored tablets but it was visible on the DSC curve of the Abilify(®) 10 mg reference tablets. The formation of the monohydrate was observed in the diffractograms and Raman spectra in the tablets stored under accelerated conditions. The monohydrate phase was not detected in the tablets stored in the Al/Al blisters under long term conditions. The results showed that the Al/Al blisters can be recommended as the packaging of the aripiprazole tablets containing form III. PMID:26397209

  6. Natural uranium in Forsmark, Sweden: The solid phase

    International Nuclear Information System (INIS)

    Highlights: • Dissolved U was found at depths where reducing conditions would be expected. • U-bearing solid phases have been characterized in order to understand the source and timing of U oxidation. • Altered primary uraninite and uranothorite were found in local pegmatites. • Secondary CaU(VI)-silicates are associated with calcite and >1 Ga fracture minerals. • Coffinitized uraninite is associated with (Ca)FeAl-silicates and sulfides/sulfates of Palaeozoic age. - Abstract: U-bearing solid phases from Forsmark, Sweden, a proposed host for radioactive waste repositories, have been identified and characterized. Elevated dissolved U was found in some groundwater samples during the site investigations, prompting a need to study the local U geochemistry. Previous hydrochemical and whole-rock geochemical studies indicated that U was derived from local pegmatites, and mobilized and re-deposited during several geological events. In this study, down-hole gamma logs guided sampling of local pegmatites, cataclasites, and fracture fillings. Back-scattered electron-imaging, petrographic microscopy, and electron microprobe analyses were used to find and analyze U phases in thin sections. The results show that the principal U sources at Forsmark include pegmatitic uraninite (PbO up to ∼22 wt%) and metamict uranothorite. These primary minerals show variable degrees of alteration such as enrichment in Ca and Al and/or replacement by secondary Ca–U(VI)-silicates, haiweeite and uranophane. The haiweeite contains up to ∼5 wt% Al2O3, a chemical signature reflecting early (Proterozoic) events of hydrothermal fluid migration. Coffinitized, secondary uraninite is found in association with FeAl-silicates or Palaeozoic sulfide/sulfate minerals, indicating remobilization-precipitation and/or a secondary, sedimentary source of U. It is inferred that U was oxidized during geologically early periods. Later, U(IV) phases formed in fractures open to fluid circulation during the

  7. Critical Regimes of Two-Phase Flows with a Polydisperse Solid Phase

    CERN Document Server

    Barsky, Eugene

    2010-01-01

    This book brings to light peculiarities of the formation of critical regimes of two-phase flows with a polydisperse solid phase. A definition of entropy is formulated on the basis of statistical analysis of these peculiarities. The physical meaning of entropy and its correlation with other parameters determining two-phase flows are clearly defined. The interrelations and main differences between this entropy and the thermodynamic one are revealed. The main regularities of two-phase flows both in critical and in other regimes are established using the notion of entropy. This parameter serves as a basis for a deeper insight into the physics of the process and for the development of exhaustive techniques of mass exchange estimation in such flows. The book is intended for graduate and postgraduate students of engineering studying two-phase flows, and to scientists and engineers engaged in specific problems of such fields as chemical technology, mineral dressing, modern ceramics, microelectronics, pharmacology, po...

  8. Ferrofluid-based dispersive solid phase extraction of palladium.

    Science.gov (United States)

    Farahani, Malihe Davudabadi; Shemirani, Farzaneh; Gharehbaghi, Maysam

    2013-05-15

    A new mode of dispersive solid phase extraction based on ferrofluid has been developed. In this method, an appropriate amount of ferrofluid is injected rapidly into the aqueous sample by a syringe. Since the sorbent is highly dispersed in the aqueous phase, extraction can be achieved within a few seconds. The ferrofluid can be attracted by a magnet and no centrifugation step is needed for phase separation. Palladium was used as a model compound in the development and evaluation of the extraction procedure in combination with flame atomic absorption spectrometry. The experimental parameters (pH, DDTC concentration, type and concentration of eluent, the amount of adsorbent, extraction time, and the effect of interfering ions) were investigated in detail. Under the optimized conditions, the calibration graph was linear over the range of 1-100 μg L(-1) and relative standard deviation of 3.3% at 0.1 μg mL(-1) was obtained (n=7). The limit of detection and enrichment factor (EF) was obtained to be 0.35 μg L(-1) and 267, respectively. The maximum adsorption capacity of the adsorbent at optimum conditions was found to be 24.6 mg g(-1) for Pd(II). The method was validated using certified reference material, and has been applied for the determination of trace Pd(II) in actual samples with satisfactory results. PMID:23618148

  9. Vapour phase synthesis of salol over solid acids via transesterification

    Indian Academy of Sciences (India)

    S Z Mohamed Shamshuddin; N Nagaraju

    2010-03-01

    The transesterification of methyl salicylate with phenol has been studied in vapour phase over solid acid catalysts such as ZrO2, MoO3 and SO$^{2-}_{4}$ or Mo(VI) ions modified zirconia. The catalytic materials were prepared and characterized for their total surface acidity, BET surface area and powder XRD patterns. The effect of mole-ratio of the reactants, catalyst bed temperature, catalyst weight, flowrate of reactants, WHSV and time-on-stream on the conversion (%) of phenol and selectivity (%) of salol has been investigated. A good yield (up to 70%) of salol with 90% selectivity was observed when the reactions were carried out at a catalyst bed temperature of 200°C and flow-rate of 10 mL/h in presence of Mo(VI)/ZrO2 as catalyst. The results have been interpreted based on the variation of acidic properties and powder XRD phases of zirconia on incorporation of SO$^{2-}_{4}$ or Mo(VI) ions. The effect of poisoning of acid sites of SO$^{2-}_{4}$ or Mo(VI) ions modified zirconia on total surface acidity, powder XRD phases and catalytic activity was also studied. Possible reaction mechanisms for the formation of salol and diphenyl ether over acid sites are proposed.

  10. Gamma ray tomography and solid phase hold-up measurements in a gas-solid circulating fluidized bed

    International Nuclear Information System (INIS)

    Chemical industry has numerous cases wherein reactions are carried between reactants that exist in different phases. Equipment designed for such a reaction is called multiphase reactor and intimate contact between the phases in any multiphase reactor is a must to achieve high efficiencies. When the reactants are in gas and solid phases or when the solid phase is a catalyst or a product to be dried in a gas stream, better contact efficiency can be achieved by suspending fine solids in the high velocity of fluid streams. A number of configurations are possible for carrying out such operations, such as rotary bed, fixed bed, moving bed, and fluidized bed and its several sub-configurations. Circulating fluidized bed (Cf) is a special mode of fluidization, and comprises of a tall riser column in which the solids are fluidized at high carrier phase velocity (gas and/or liquid). The entrained solids are captured in a cyclone or bag filters and returned back to the bottom of the riser continuously. CFB has found important applications in petroleum and power industry. Fluidized catalytic cracking of crude naphtha to petroleum products is carried out in a CFB system wherein the catalyst particles are suspended and entrained at high temperature in gasified naphtha in the riser column. Naphtha cracking is a multi-million dollar application of CFB and requires close study for efficiency and performance. Optimized operation of a CFB requires knowledge of solid phase holdup profiles and residence time distribution in the riser column. Attempts, direct and indirect, have been made to accurately measure these quantities. Use of radioisotopes offers a powerful and cost effective method for estimating both solid phase holdup profiles as well as residence time distribution in continuous multiphase flow. Efforts were therefore made through this investigation to determine solid phase axial and radial holdup profiles in the riser section of a 'cold' gas-solid circulating fluidized bed

  11. Development of a solid phase RIA for human plasma somatostatin

    International Nuclear Information System (INIS)

    Somatostatin is widely distributed in tissues of biological fluids. In the present study we tested the validity of a new radioimmunoassay by a solid phase immunoextraction. Sensitivity was 1.8 pg/mL and the within-assay precision with two different pools of human plasma was 12.2% (CV) at a concentration of 19.2 ± 2.34 pg/ml (mean ± SD) and 11.9% at 8.53 ± 1.02 pg/ml. The between assay precision was 14.2% (CV) at a concentration of 11.8 ± 1.68 pg/ml. The accuracy was good as tested by the dilution test and the recovery test. The method had good correlation with a current extraction method. Basal value of somatostatin in the plasma of 32 normal subjects was 11.5 ± 5.80 pg/ml. (author)

  12. Nanoscale doping of compound semiconductors by solid phase dopant diffusion

    Science.gov (United States)

    Ahn, Jaehyun; Chou, Harry; Koh, Donghyi; Kim, Taegon; Roy, Anupam; Song, Jonghan; Banerjee, Sanjay K.

    2016-03-01

    Achieving damage-free, uniform, abrupt, ultra-shallow junctions while simultaneously controlling the doping concentration on the nanoscale is an ongoing challenge to the scaling down of electronic device dimensions. Here, we demonstrate a simple method of effectively doping ΙΙΙ-V compound semiconductors, specifically InGaAs, by a solid phase doping source. This method is based on the in-diffusion of oxygen and/or silicon from a deposited non-stoichiometric silicon dioxide (SiOx) film on InGaAs, which then acts as donors upon activation by annealing. The dopant profile and concentration can be controlled by the deposited film thickness and thermal annealing parameters, giving active carrier concentration of 1.4 × 1018 cm-3. Our results also indicate that conventional silicon based processes must be carefully reviewed for compound semiconductor device fabrication to prevent unintended doping.

  13. TEM characterization of Solid-Phase Epitaxy in amorphized polysilicon

    International Nuclear Information System (INIS)

    Solid Phase Epitaxy (SPE) of amorphous silicon thin films can be employed to build novel device structures for VLSI applications. One way of achieving SPE is to use a room temperature silicon implant to amorphize a polysilicon layer followed by a thermal treatment to promote epitaxial growth. Both vertical SPE, in which the epitaxial film is grown directly on silicon substrate, and lateral SPE, in which the epitaxial growth is extended over a thin layer of oxide using the vertical SPE region as a seed, have been realized using this approach. This paper presents results obtained by cross-sectional TEM analysis of the epitaxial films, with particular emphasis on the effects of implant schedule and annealing conditions on the epitaxial regrowth

  14. Solid phase epitaxial regrowth of (001) anatase titanium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Barlaz, David Eitan; Seebauer, Edmund G., E-mail: eseebaue@illinois.edu [Department of Chemical and Biomolecular Engineering, University of Illinois, 600 S Mathews Ave., Urbana, Illinois 61801 (United States)

    2016-03-15

    The growing interest in metal oxide based semiconductor technologies has driven the need to produce high quality epitaxial films of one metal oxide upon another. Largely unrecognized in synthetic efforts is that some metal oxides offer strongly polar surfaces and interfaces that require electrostatic stabilization to avoid a physically implausible divergence in the potential. The present work examines these issues for epitaxial growth of anatase TiO{sub 2} on strontium titanate (001). Solid phase epitaxial regrowth yields only the (001) facet, while direct crystalline growth by atomic layer deposition yields both the (112) and (001). The presence of amorphous TiO{sub 2} during regrowth may provide preferential stabilization for formation of the (001) facet.

  15. Municipal solid waste development phases: Evidence from EU27.

    Science.gov (United States)

    Vujić, Goran; Gonzalez-Roof, Alvaro; Stanisavljević, Nemanja; Ragossnig, Arne M

    2015-12-01

    Many countries in the European Union (EU) have very developed waste management systems. Some of its members have managed to reduce their landfilled waste to values close to zero during the last decade. Thus, European Union legislation is very stringent regarding waste management for their members and candidate countries, too. This raises the following questions: Is it possible for developing and developed countries to comply with the European Union waste legislation, and under what conditions? How did waste management develop in relation to the economic development in the countries of the European Union? The correlation between waste management practices and economic development was analysed for 27 of the European Union Member States for the time period between 1995 and 2007. In addition, a regression analysis was performed to estimate landfilling of waste in relation to gross domestic product for every country. The results showed a strong correlation between the waste management variables and the gross domestic product of the EU27 members. The definition of the municipal solid waste management development phases followed a closer analysis of the relation between gross domestic product and landfilled waste. The municipal solid waste management phases are characterised by high landfilling rates at low gross domestic product levels, and landfilling rates near zero at high gross domestic product levels. Hence the results emphasize the importance of wider understanding of what is required for developing countries to comply with the European Union initiatives, and highlight the importance of allowing developing countries to make their own paths of waste management development. PMID:26574580

  16. RADIOCHEMICAL STUDIES ON ALPHA FETOPROTEIN RADIOIMMUNOASSAY SOLID PHASE COATED BEADS

    International Nuclear Information System (INIS)

    Alpha fetoprotein (AFP) is a marker for hepatocellular and germ cell carcinoma. There are many different techniques used for measuring AFP in blood where the most accurate one is the immunoassay technique. The aim of the present study was to evaluate, optimize and prepare anti-AFP solid phase coated beads and use it for the determination of AFP in serum. The anti-AFP polyclonal antibodies were prepared by immunization of five rats with a highly purified AFP antigen and the anti-sera obtained were used for coating polystyrene beads to obtain the solid phase coated beads. Also, the AFP antigen was labelled with 125 I using chloramin-T (Ch-T) as oxidizing agent and the tracer obtained was purified using sephadex G-25 (PD-10) chromatography. The assay was performed using a set of AFP standards prepared by diluting the cord blood. The suitable conditions for coating process were obtained which include pH 8, molarity of coating buffer 0.05 M, volume of coating buffer 100 ml and dilution of antibody 1:1000 for coating 1000 beads. Because the coated beads prepared using borate buffer is more suitable than prepared using carbonate or phosphate buffers, they were chosen to complete the optimization and validation study. The optimization and characterization of the assay were performed to evaluate the quality of the proposed system. The system prepared proved a low cost, simple, sensitive and accurate results. The prepared system can be used to evaluate AFP in the blood and this will be helpful in diagnosing some diseases such as hepatocellular carcinoma and neural tube defects

  17. Solid-Phase Thermophilic Aerobic Reactor (STAR) Processing of Fecal, Food, and Plant Residues

    OpenAIRE

    2006-01-01

    A description of the Solid Waste Resource Recovery ALS-NSCORT projects: Solid Phase Thermophilic Aerobic Reactor (STAR), Nitrogen Cycling in Advanced Life Support Systems, and Plant-based Anaerobic-Aerobic Bioreactor Linked Operation (PAABLO). 26 pages.

  18. New methods and materials for solid phase extraction and high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Dumont, P.J.

    1996-04-23

    This paper describes methods for solid phase extraction and high performance liquid chromatography (HPLC). The following are described: Effects of Resin Sulfonation on the Retention of Polar Organic Compounds in Solid Phase Extraction; Ion-Chromatographic Separation of Alkali Metals In Non-Aqueous Solvents; Cation-Exchange Chromatography in Non-Aqueous Solvents; and Silicalite As a Stationary Phase For HPLC.

  19. Development of novel solid-phase protein formulations

    Science.gov (United States)

    Montalvo Ortiz, Brenda Liz

    Proteins are the next-generation drugs for the treatment of several diseases. However, the number of protein drugs is still limited due to the physical or chemical instability of proteins during processing, formulation, storage, and delivery. The formulation of proteins at the solid state has advantages over liquid state, such as improved stability during long-term storage and delivery and decreases transportation costs. In this dissertation, we developed new solid-phase protein formulations in which the integrity of the protein was not compromised. The long term goal of this research was to use these protein formulations to improve protein stability in drug delivery devices, such as poly(lactic-co-glycolic) acid (PLGA). The first solid-phase protein formulation developed in this investigation was named "glassification". We proposed glassification as an alternative protein dehydration technique to the common used one, lyophilization, because this last method involves a series of steps which are detrimental to protein structure and stability. The glassification method consisted on protein dehydration by the use of organic solvents. As a result of the glassification process a small (micrometer size range) protein solid bead was obtained. The proteins used to study the glassification process were lysozyme (LYS), alpha-chymotrypsin (CHYMO) and horseradish peroxidase (HRP). These studies revealed that the glassification process itself did not alter protein structure and the activity was preserved. Ethyl acetate was the most effective organic solvent for protein glassification because it led to the highest protein residual activity, no insoluble aggregate formation and is a relatively non-toxic solvent, which allow the incorporation of these protein microparticles in PLGA microspheres. The incorporation of spherical HRP microparticles into PLGA microspheres resulted in superior properties when compared with encapsulated lyophilized HRP powder, such as improved release

  20. Solid Phase Formylation of N-Terminus Peptides

    Directory of Open Access Journals (Sweden)

    Anna Lucia Tornesello

    2016-06-01

    Full Text Available Formylation of amino groups is a critical reaction involved in several biological processes including post-translational modification of histones. The addition of a formyl group (CHO to the N-terminal end of a peptide chain generates biologically active molecules. N-formyl-peptides can be produced by different methods. We performed the N-formylation of two chemotactic hexapetides, Met1-Leu2-Lys3-Leu4-Ile5-Val6 and Met1-Met2-Tyr3-Ala4-Leu5-Phe6, carrying out the reaction directly on peptidyl-resin following pre-activation of formic acid with N,N-dicyclohexylcarbodiimmide (DCC in liquid phase. The overnight incubation at 4 °C resulted in a significant increase in production yields of formylated peptides compared to the reaction performed at room temperature. The method is consistently effective, rapid, and inexpensive. Moreover, the synthetic strategy can be applied for the formylation of all primary amines at N-terminus of peptide chains or amino groups of lysine side-chains in solid phase.

  1. Automated Solid-Phase Radiofluorination Using Polymer-Supported Phosphazenes

    Directory of Open Access Journals (Sweden)

    Bente Mathiessen

    2013-08-01

    Full Text Available The polymer supported phosphazene bases PS-P2tBu and the novel PS-P2PEG allowed for efficient extraction of [18F]F− from proton irradiated [18O]H2O and subsequent radiofluorination of a broad range of substrates directly on the resin. The highest radiochemical yields were obtained with aliphatic sulfonates (69% and bromides (42%; the total radiosynthesis time was 35–45 min. The multivariate analysis showed that the radiochemical yields and purities were controlled by the resin load, reaction temperature, and column packing effects. The resins could be reused several times with the same or different substrates. The fully automated on-column radiofluorination methodology was applied to the radiosynthesis of the important PET radiotracers [18F]FLT and [18F]FDG. The latter was produced with 40% yield on a 120 GBq scale and passed GMP-regulated quality control required for commercial production of [18F]FDG. The combination of compact form factor, simplicity of [18F]F− recovery and processing, and column reusability can make solid phase radiofluorination an attractive radiochemistry platform for the emerging dose-on-demand instruments for bedside production of PET radiotracers.

  2. Automated solid-phase peptide synthesis to obtain therapeutic peptides

    Directory of Open Access Journals (Sweden)

    Veronika Mäde

    2014-05-01

    Full Text Available The great versatility and the inherent high affinities of peptides for their respective targets have led to tremendous progress for therapeutic applications in the last years. In order to increase the drugability of these frequently unstable and rapidly cleared molecules, chemical modifications are of great interest. Automated solid-phase peptide synthesis (SPPS offers a suitable technology to produce chemically engineered peptides. This review concentrates on the application of SPPS by Fmoc/t-Bu protecting-group strategy, which is most commonly used. Critical issues and suggestions for the synthesis are covered. The development of automated methods from conventional to essentially improved microwave-assisted instruments is discussed. In order to improve pharmacokinetic properties of peptides, lipidation and PEGylation are described as covalent conjugation methods, which can be applied by a combination of automated and manual synthesis approaches. The synthesis and application of SPPS is described for neuropeptide Y receptor analogs as an example for bioactive hormones. The applied strategies represent innovative and potent methods for the development of novel peptide drug candidates that can be manufactured with optimized automated synthesis technologies.

  3. Quasi in situ observation of Si lateral solid phase epitaxy

    Science.gov (United States)

    Ueno, T.; Kawai, K.; Morisawa, T.; Hatano, T.; Imai, S.; Kaneko, S.; Ohdomari, I.

    A quasi in situ observation of Si lateral solid phase epitaxy (L-SPE) has been carried out by an anneal-and-observe technique using a transmission electron microscope (TEM). For this observation, 3 mm Ø Si discs, which were thinned physically and chemically, were cut from a non-heated sample which had been prepared by depositing an amorphous Si (a-Si) film on the patterned amorphous insulator substrate. For the L-SPE growth, the thin specimens were heated in a furnace. The same areas of the same sample were repeatedly observed after an additional heating process at each interval. The direct origin of the (111) facet formation during the L-SPE growth has been precisely revealed by this method. Polygrains due to the random nucleation from the a-Si/a-insulator interface have been found to obstruct further L-SPE growth, while the L-SPE growth continued in the adjacent polygrain-free regions. As a result of this non-uniform growth rate, the (111) facets which nucleated at the polygrains grew into V-shaped valleys and finally caused a zig-zag growth front.

  4. Solid Phase Microextraction for the Analysis of Nuclear Weapons

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, D M

    2001-06-01

    This document is a compendium of answers to commonly asked questions about solid phase microextraction as it relates to the analysis of nuclear weapons. We have also included a glossary of terms associated with this analytical method as well as pertinent weapons engineering terminology. Microextraction is a new collection technique being developed to nonintrusively sample chemicals from weapon headspace gases for subsequent analysis. The chemicals that are being targeted outgas from the high explosives and other organic materials used in the weapon assembly. This technique is therefore a valuable tool to: (1) remotely detect and assess the aging of Lawrence Livermore National Laboratory (LLNL) and, in some cases, Sandia National Laboratory (SNL) organic materials; and (2) identify potential compatibility issues (i.e., materials interactions) that should be more carefully monitored during surveillance tear-downs. Microextraction is particularly attractive because of the practical constraints inherent to the weapon surveillance procedure. To remain transparent to other core surveillance activities and fall within nuclear safety guidelines, headspace analysis of the weapons requires a procedure that: (1) maintains ambient temperature conditions; (2) allows practical collection times of less than 20 min; (3) maintains the integrity of the weapon gas volume; (4) provides reproducible and quantitative results; and (5) can identify all possible targets.

  5. Phase I studies of porfiromycin (NSC--56410) in solid tumors.

    Science.gov (United States)

    Grage, T B; Weiss, A J; Wilson, W; Reynolds, V

    1975-01-01

    Porfiromycin was given to a group of patients with a variety of solid tumors. Of 114 patients admitted to the study, 103 yielded evaluable data. The following dosage schedules were used to determine the toxicity of porfiromycin when given in multiple doses by intravenous injection: 0.2 mg/kg x 5 days, 0.3 mg/kg x 5 days, 0.35 mg/kg x 5 days, 0.4 mg/kg x 5 days, 0.24 mg/kg x 10 days and 0.6 mg/kg weekly. Toxic effects noted were mainly leukopenia, thrombocytopenia, and, when injected paravenously, local tissue necrosis. Biological effects were noted at all dosage levels and were more severe at the higher dosages. The data suggest that profiromycin administered intravenously at a dose of 0.35 mg/kg daily for 5 days results in moderate hermatological toxicity and clinical evaluation in a Phase II study at this dosage level is indicated. PMID:1177472

  6. Solid phase group specific absorbants in assays for glycoproteins

    International Nuclear Information System (INIS)

    The focus of this paper is on several technical advances in the assays for glycoprotein hormones and enzymes that have been achieved by use of the solid phase carbohydrate specific adsorbant concanavalin-A. Puriffication of glycoprotein radioligand after labelling by the chloramine-T method is readily accomplished using a small column of agarose bound concanavalin-A which separates glycoprotein radioligand from radioiodide and radiolabelled unadsorbed contaminants. After concanavalin-A column chromatography, radiolabelled glycoprotein hormone preparations exhibited improved binding to antibodies and tissue receptors. To increase the effective sensitivity of radioimmunoassays for glycoproteins, agarose bound concanavalin-A is used to extract and concentrate the glycoproteins from various biologic samples. For example, the effective sensitivity for the detection of human thyrotropin in serum was improved approximately 5 fold by using concanavalin-A concentrates of 1.5 ml of serum. Partial purification of the glycoprotein dopamine-β-hydroxylase from serum using agarose bound concanavalin-A resulted in separation of the serum factors that interfere with the measurement of enzyme activity. We conclude that in assays for glycoproteins, concanavalin-A is useful for purification of radioligand, for preparation of concentrates of glycoproteins from biologic samples, and for separation of glycoproteins from various interfering factors contained in biologic samples prior to radioligand or radioenzyme assay. (orig.)

  7. Solid phase epitaxy of amorphous silicon carbide: Ion fluence dependence

    International Nuclear Information System (INIS)

    We have investigated the effect of radiation damage and impurity concentration on solid phase epitaxial growth of amorphous silicon carbide (SiC) as well as microstructures of recrystallized layer using transmission electron microscopy. Single crystals of 6H-SiC with (0001) orientation were irradiated with 150 keV Xe ions to fluences of 1015 and 1016/cm2, followed by annealing at 890 deg. C. Full epitaxial recrystallization took place in a specimen implanted with 1015 Xe ions, while retardation of recrystallization was observed in a specimen implanted with 1016/cm2 Xe ions. Atomic pair-distribution function analyses and energy dispersive x-ray spectroscopy results suggested that the retardation of recrystallization of the 1016 Xe/cm2 implanted sample is attributed to the difference in amorphous structures between the 1015 and 1016 Xe/cm2 implanted samples, i.e., more chemically disordered atomistic structure and higher Xe impurity concentration in the 1016 Xe/cm2 implanted sample

  8. Solid-phase microextraction and the human fecal VOC metabolome.

    Directory of Open Access Journals (Sweden)

    Emma Dixon

    Full Text Available The diagnostic potential and health implications of volatile organic compounds (VOCs present in human feces has begun to receive considerable attention. Headspace solid-phase microextraction (SPME has greatly facilitated the isolation and analysis of VOCs from human feces. Pioneering human fecal VOC metabolomic investigations have utilized a single SPME fiber type for analyte extraction and analysis. However, we hypothesized that the multifarious nature of metabolites present in human feces dictates the use of several diverse SPME fiber coatings for more comprehensive metabolomic coverage. We report here an evaluation of eight different commercially available SPME fibers, in combination with both GC-MS and GC-FID, and identify the 50/30 µm CAR-DVB-PDMS, 85 µm CAR-PDMS, 65 µm DVB-PDMS, 7 µm PDMS, and 60 µm PEG SPME fibers as a minimal set of fibers appropriate for human fecal VOC metabolomics, collectively isolating approximately 90% of the total metabolites obtained when using all eight fibers. We also evaluate the effect of extraction duration on metabolite isolation and illustrate that ex vivo enteric microbial fermentation has no effect on metabolite composition during prolonged extractions if the SPME is performed as described herein.

  9. A study on nuclear propulsion using gas-solid two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Miyato, Naoaki; Kataoka, Isao; Serizawa, Akimi [Kyoto Univ. (Japan). Faculty of Engineering

    1997-05-01

    A solid core nuclear rocket has been considered a candidate for the first manned mission to Mars. The reason is that the solid core nuclear rocket has higher specific impulse than a chemical rocket. But its engine thrust is as much as that of the chemical rocket. We have thought of use of gas-solid two-phase flow for higher engine thrust on nuclear thermal propulsion and examined the effect of gas-solid two-phase flow on the engine thrust and the specific impulse of the solid core nuclear rocket. (author)

  10. Equilibrium phases surrounding the αZr solid solution in the Zr-Sn-O system

    International Nuclear Information System (INIS)

    Phases in equilibrium with the αZr solid solution from 1010-1314oC (1287-1587 K) in zirconium-tin-oxygen alloys were characterized and their compositions were determined. The experimental results provide information on the equilibria of the αZr solid solution in order to propose tentative boundaries at isothermal sections of the phase diagram. (Author)

  11. Solid-state retrodirective phased array concepts for microwave power transmission from Solar Power Satellite

    Science.gov (United States)

    Schroeder, K. G.; Petroff, I. K.

    1980-01-01

    Two prototype solid-state phased array systems concepts for potential use in the Solar Power Satellite are described. In both concepts, the beam is centered on the rectenna by means of phase conjugation of a pilot signal emanating from the ground. Also discussed is on-going solid-state amplifier development.

  12. Facile synthesis of aliphatic isothiocyanates and thioureas on solid phase using peptide coupling reagents

    DEFF Research Database (Denmark)

    Boas, Ulrik; Andersen, Heidi Gertz; Christensen, Jørn B.;

    2004-01-01

    Peptide coupling reagents can be used as versatile reagents for the formation of aliphatic isothiocyanates and thioureas on solid phase from the corresponding solid-phase anchored aliphatic primary amines. The formation of the thioureas is fast and highly chemoselective, and proceeds via formatio...

  13. Novel materials and methods for solid-phase extraction and liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Ambrose, D.

    1997-06-24

    This report contains a general introduction which discusses solid-phase extraction and solid-phase micro-extraction as sample preparation techniques for high-performance liquid chromatography, which is also evaluated in the study. This report also contains the Conclusions section. Four sections have been removed and processed separately: silicalite as a sorbent for solid-phase extraction; a new, high-capacity carboxylic acid functionalized resin for solid-phase extraction; semi-micro solid-phase extraction of organic compounds from aqueous and biological samples; and the high-performance liquid chromatographic determination of drugs and metabolites in human serum and urine using direct injection and a unique molecular sieve.

  14. Porous, High Capacity Coatings for Solid Phase Microextraction by Sputtering.

    Science.gov (United States)

    Diwan, Anubhav; Singh, Bhupinder; Roychowdhury, Tuhin; Yan, DanDan; Tedone, Laura; Nesterenko, Pavel N; Paull, Brett; Sevy, Eric T; Shellie, Robert A; Kaykhaii, Massoud; Linford, Matthew R

    2016-02-01

    We describe a new process for preparing porous solid phase microextraction (SPME) coatings by the sputtering of silicon onto silica fibers. The microstructure of these coatings is a function of the substrate geometry and mean free path of the silicon atoms, and the coating thickness is controlled by the sputtering time. Sputtered silicon structures on silica fibers were treated with piranha solution (a mixture of concd H2SO4 and 30% H2O2) to increase the concentration of silanol groups on their surfaces, and the nanostructures were silanized with octadecyldimethylmethoxysilane in the gas phase. The attachment of this hydrophobic ligand was confirmed by X-ray photoelectron spectroscopy and contact angle goniometry on model, planar silicon substrates. Sputtered silicon coatings adhered strongly to their surfaces, as they were able to pass the Scotch tape adhesion test. The extraction time and temperature for headspace extraction of mixtures of alkanes and alcohols on the sputtered fibers were optimized (5 min and 40 °C), and the extraction performances of SPME fibers with 1.0 or 2.0 μm of sputtered silicon were compared to those from a commercial 7 μm poly(dimethylsiloxane) (PDMS) fiber. For mixtures of alcohols, aldehydes, amines, and esters, the 2.0 μm sputtered silicon fiber yielded signals that were 3-9, 3-5, 2.5-4.5, and 1.5-2 times higher, respectively, than those of the commercial fiber. For the heavier alkanes (undecane-hexadecane), the 2.0 μm sputtered fiber yielded signals that were approximately 1.0-1.5 times higher than the commercial fiber. The sputtered fibers extracted low molecular weight analytes that were not detectable with the commercial fiber. The selectivity of the sputtered fibers appears to favor analytes that have both a hydrophobic component and hydrogen-bonding capabilities. No detectable carryover between runs was noted for the sputtered fibers. The repeatability (RSD%) for a fiber (n = 3) was less than 10% for all analytes tested

  15. Biological treatment of soils contaminated with hydrophobic organics using slurry and solid phase techniques

    International Nuclear Information System (INIS)

    Both slurry-phase and solid-phase bioremediation are effective ex situ soil decontamination methods. Slurry is energy intensive relative to solid-phase treatment, but provides homogenization and uniform nutrient distribution. Limited contaminant bioavailability at concentrations above the required cleanup level reduces biodegradation rates and renders solid phase bioremediation more cost effective than complete treatment in a bioslurry reactor. Slurrying followed by solid-phase bioremediation combines the advantages and minimizes the weaknesses of each treatment method when used alone. A biological treatment system consisting of slurrying followed by aeration in solid phase bioreactors was developed and tested in the laboratory using a silty clay load contaminated with diesel fuel. The first set of experiments was designed to determine the impact of the water content and mixing time during slurrying on the ate and extent of contaminant removal in continuously aerated solid phase bioreactors. The second set of experiments compared the volatile and total diesel fuel removal in solid phase bioreactors using periodic and continuous aeration strategies

  16. Liquid-solid phase extraction of rare earth chlorides by oil sulfoxides

    International Nuclear Information System (INIS)

    Liquid - solid phase extraction of rare earth chlorides by oil sulfoxides is studied. It is determined that during extraction of anhydrous rare earth chlorides organic phase is enriched by heavy lanthanides. During extraction of crystal hydrates (H2O:M>5) it enriched by light lanthanides and separation factor increases with temperature growth. It is pointed out that solvent nature does not offer essential effect on isolation of chlorides of d- and f-elements during liquid - solid phase extraction

  17. Materials research for passive solar systems: solid-state phase-change materials

    Energy Technology Data Exchange (ETDEWEB)

    Benson, D.K.; Webb, J.D.; Burrows, R.W.; McFadden, J.D.O.; Christensen, C.

    1985-03-01

    A set of solid-state phase-change materials is being evaluated for possible use in passive solar thermal energy storage systems. The most promising materials are organic solid solutions of pentaerythritol (C/sub 5/H/sub 12/O/sub 4/), pentaglycerinve (C/sub 5/H/sub 12/O/sub 3/), and neopentyl glycol (C/sub 5/H/sub 12/O/sub 2/). Solid solution mixtures of these compounds can be tailored so that they exhibit solid-to-solid phase transformations at any desired temperature betweeen 25/sup 0/C and 188/sup 0/C, and have latent heats of transformation between 20 and 70 cal/g. Transformation temperatures, specific heats, and latent heats of transformation have been measured for a number of these materials. Limited cyclic experiments suggest that the solid solutions are stable. These phase-change materials exhibit large amounts of undercooling; however, the addition of certain nucleating agents as particulate dispersions in the solid phase-change material greatly reduces this effect. Computer simulations suggest that the use of an optimized solid-state phase-change material in a Trombe wall could provide better performance than a concrete Trombe wall four times thicker and nine times heavier. Nevertheless, a higher cost of the phase-change materials (approx. =$0.70 per pound) is likely to limit their applicability in passive solar systems unless their performance can be significantly improved through further research.

  18. Crystallization and phase changes in paracetamol from the amorphous solid to the liquid phase.

    Science.gov (United States)

    Sibik, Juraj; Sargent, Michael J; Franklin, Miriam; Zeitler, J Axel

    2014-04-01

    For the case of paracetamol, we show how terahertz time-domain spectroscopy can be used to characterize the solid and liquid phase dynamics. Heating of supercooled amorphous paracetamol from 295 K in a covered sample under vacuum leads to its crystallization at 330 K. First, form III is formed followed by the transformation of form III to form II at 375 K, to form I at 405 K, and finally melting is observed around 455 K. We discuss the difference between the featureless spectra of the supercooled liquid and its liquid melt. Lastly, we studied the onset of crystallization from the supercooled liquid in detail and quantified its kinetics based on the Avrami-Erofeev model. We determined an effective rate constant of k = 0.056 min(-1) with a corresponding onset of crystallization at T = 329.5 K for a heating rate of 0.4 K min(-1). PMID:24579729

  19. Quantitative characterization of solid state phases by secondary neutral mass spectrometry

    Science.gov (United States)

    Oechsner, H.; Getto, R.; Kopnarski, M.

    2009-03-01

    The quantitative determination of chemical solid phases by secondary neutral mass spectrometry (SNMS) based on the quantitative character of this technique is described and demonstrated for several thin film structures. The intermetallic phases in a Ni-Zn coating on Fe are shown to be achieved directly from the concentration ratios determined by SNMS. When correlating the local elemental concentration tupels with the corresponding phase fractions by a matrix equation, the determination of chemical solid phase depth profiles becomes possible. This is exemplified by the detection of temperature induced chemical phases in Ni and Ti/Si films on SiC substrates.

  20. Design and Synthesis of a Dual Linker for Solid Phase Synthesis of Oleanolic Acid Derivatives

    Directory of Open Access Journals (Sweden)

    Shaorong Wang

    2011-06-01

    Full Text Available A hydrophilic amino-terminated poly(ethylene glycol-type dual linker for solid phase synthesis of oleanolic acid derivatives using trityl chloride resin was designed and synthesized for the first time. Model reactions in both liquid and solid phase were performed to show the feasibility of its selective cleavage at two different sites. The biological assay results indicated that the long and flexible alkyl ether functionality in the linker is less likely to be critical for the binding event. Following the successful solid-phase synthesis of model compounds, the potential of this dual linker in reaction monitoring and target identification is deemed worthy of further study.

  1. Temperature and phase dependence of positron lifetimes in solid cyclohexane

    DEFF Research Database (Denmark)

    Eldrup, Morten Mostgaard

    1985-01-01

    The temperature dependence of position lifetimes in both the brittle and plastic phases of cyclohaxane has been examined. Long-lived components in both phases are associated with the formation of positronium (Ps). Two long lifetimes attributable to ortho-Ps are resolvable in the plastic phase. The...

  2. Quantum control of two-photon photochromism in a solid-state phase

    International Nuclear Information System (INIS)

    The possibility of the phase and polarization control of the photochromism event in the solid-state phase is experimentally demonstrated. The quantum control of the photochromic processes initiated by the two-photon absorption of the femtosecond laser pulses in the spiropyran voluminous polymer sample is accomplished through the change in the polarization state and phase modulation parameter of the laser pulses

  3. Liquid phase sintering, II: Computer study of skeletal settling and solid phase extrication in a microgravity environment

    Directory of Open Access Journals (Sweden)

    Nikolić Z.S.

    2008-01-01

    Full Text Available A two-dimensional numerical method based on the Brownian motion model and on the Densification model for simulation of liquid phase sintering in microgravity environment will be developed. Both models will be based on domain topology (two-dimensional particle representation and control volume methodology and on three submodels for domain translation, solid skeleton formation and domain extrication. This method will be tested in order to conduct a study of diffusion phenomena and microgravitational effects on microstructural evolution influenced by skeletal settling combined with solid-phase extrication during liquid phase sintering of porous W-Ni system.

  4. On-chip solid phase extraction coupled with electrophoresis using modified magnetic microspheres as stationary phase

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A poly(dimethylsiloxane)(PDMS)/glass hybrid microchip for on-line solid phase extraction (SPE) and electrophoresis separation has been developed and evaluated. The SPE microchannel was crossed to the electrophoresis microchannel. All the microfluidic channels were etched on the glass substrate. The magnetic microspheres were coated with hydroxyl-terminated poly-dimethylsiloxane (PDMS-OH) serving as extraction phase,which could be conveniently immobilized into the sample pretreatment channel by magnetic field. The PDMS-OH microspheres were mobilized into and out of the pretreatment channel by injection flow. The 0.1 μmol/L solution of fluorescence isothiocyanate (FITC)-labeled phenylalanine (Phe) was electrically injected into the SPE channel and extracted onto the PDMS-OH microspheres bed. The enriched FITC-labeled Phe was electrically eluted by 9 mmol/L sodium acetate containing 10% acetonitrile and electrically driven into the electrophoresis channel and then separated. The preconcentration factor could reach 87.5 after sufficient extraction. A linear preconcentration curve was obtained with the initial FITC-labeled Phe concentration ranging from 6 nmol/L to 300 nmol/L (R2=0.9922) with 200 s loading time. The detection limit (S/N=3) for the FITC-labeled Phe was 3 nmol/L.

  5. Preparation and application of magnetic particle solid-phase second antibody for RIA

    International Nuclear Information System (INIS)

    A separation reagent of magnetic particle solid-phase second antibody for RIA has been studied. Amine silane modulated magnetic particles were activated using glutaraldehyde and coupled with purified second antibody at different pH values. And the experiment on adsorption of purified second antibody by non-activated magnetic particles at pH 8 was carried out simultaneously. The RIA test demonstrated that the binding percentage of non-activated magnetic particle solid-phase was lower and its stability was less than that of the activated magnetic particle solid-phase. The sensitivity was increased and the correlation coefficient of standard cure was 0.9950 for the activated magnetic particle solid-phase second antibody for CEA RIA. The correlation coefficient of the testing concentration in RIA between separations with liquid-phase and solid-phase was 0.9895. Therefore, it is possible for the magnetic particle solid-phase to be used as a general separation reagent for RIA. (authors)

  6. Solid-phase distribution in an airlift reactor with an enlarged degassing zone

    OpenAIRE

    Freitas, Carla Maria Duarte de; Teixeira, J.A.

    1998-01-01

    The distribution of the solid-phase in an airlift reactor of the concentric draught tube type, with an enlarged degassing zone, has been determined. Samples were taken at eight points of the reactor for various airflow rates, solids loading and density. Hold-up of solids varied considerably within the reactor. The highest value, for all tested experimental conditions, was obtained immediately above the top of the riser and the lowest value near the wall of the degassing zone.

  7. Study on New Sensitive Method of Determination of Phosphorus by Solid Phase Spectrophotometry

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The use of solid phase spectrophotometry for the determination of trace phosphorus in the system of phosphomolybdate-fructose is described. The adsorption of the system on anion-exchange resin is reported.

  8. Fast, copper-free click chemistry: a convenient solid-phase approach to oligonucleotide conjugation

    OpenAIRE

    Singh, Ishwar; Vyle, Joseph S.; Heaney, Frances

    2009-01-01

    Solid-phase oligonucleotide conjugation by nitrile oxide–alkyne click cycloaddition chemistry has been successfully demonstrated; the reaction, compatible with all nucleobases, requires no metal catalyst and proceeds under physiological conditions.

  9. Use of track detectors in solid phase in solving of radon problems

    International Nuclear Information System (INIS)

    In this thesis track detectors in solid phase in solving of radon problems were used. Risk of lung carcinomas formation is estimated. Results of radon monitoring in houses and caves in the Slovak Republic are presented

  10. Solid-Phase Synthesis of PEGylated Lipopeptides Using Click Chemistry

    DEFF Research Database (Denmark)

    Jølck, Rasmus Irming; Berg, Rolf Henrik; Andresen, Thomas Lars

    2010-01-01

    A versatile methodology for efficient synthesis of PEGylated lipopeptides via CuAAC “Click” conjugation between alkyne-bearing solid-supported lipopeptides and azido-functionalized PEGs is described. This new and very robust method offers a unique platform for synthesizing PEGylated lipopeptides ...

  11. SOLID PHASE SPECTROPHOTOMETRIC DETERMINATION OF SELENIUM(IV) USING DITHISONE IMMOBILIZED IN A POLYMETHACRYLATE MATRIX

    OpenAIRE

    Gavrilenko, N. A.; Saranchina, N. V.; Gavrilenko, M. A.

    2014-01-01

    This paper presents a solid-phase spectrophotometric method for the determination selenium(IV). The proposed method is based on the reaction between the selenium(IV) and dithizone immobilized into transparent polymethacrylate matrix in strongly acidic solution. It was shown that the interaction of selenium(IV) with dithizone in solid phase was accompanied by the formation of the complex with an absorption maximum 420 nm. The change of absorption at wavelength 610 nm corresponding to absorptio...

  12. Molecularly Imprinted Solid-Phase Extraction and Liquid Chromatography for Biological Samples

    OpenAIRE

    Möller, Kristina

    2006-01-01

    This thesis focuses on the use of molecularly imprinted polymers as selective sorbents for solid-phase extraction (MISPE). The MISPE methods developed were mainly intended for use with biological samples, such as human urine and blood plasma. These body fluids are complex samples, which often need an effective clean-up step before analysis to reduce the levels of possible interfering substances from the matrix, especially if the analytes are present in trace amounts. Solid-phase extraction (S...

  13. Design of molecularly imprinted polymers for sensors and solid phase extraction

    OpenAIRE

    Subrahmanyam, Sreenath

    2002-01-01

    This thesis presents broadly the applications of molecularly imprinted polymers in sensors and solid phase extraction. Sensors for creatine and creatinine have been reported using a novel method of rational design of molecularly imprinted polymers (MIPs), and solid phase extraction of aflatoxin-B 1 has also been described in the thesis. A method for the selective detection of creataine and creatinine is reported in this thesis, which is based on the reaction between polymeri...

  14. Temperature and phase dependence of positron lifetimes in solid cyclohexane

    DEFF Research Database (Denmark)

    Eldrup, Morten Mostgaard

    1985-01-01

    longer of these (≈ 2.5 ns), which is temperature dependent, is ascribed to ortho-Ps trapped at vacancies. The shorter lifetime (≈ 0.9 ns), shows little temperature dependence. In contrast to most other plastic crystals, no sigmoidal behaviour of the average ortho-Ps lifetime is observed. A possibility......The temperature dependence of position lifetimes in both the brittle and plastic phases of cyclohaxane has been examined. Long-lived components in both phases are associated with the formation of positronium (Ps). Two long lifetimes attributable to ortho-Ps are resolvable in the plastic phase. The...

  15. New insights in Microbial Fuel Cells: novel solid phase anolyte

    OpenAIRE

    Tonia Tommasi; Gian Paolo Salvador; Marzia Quaglio

    2016-01-01

    For the development of long lasting portable microbial fuel cells (MFCs) new strategies are necessary to overcome critical issues such as hydraulic pump system and the biochemical substrate retrieval overtime to sustain bacteria metabolism. The present work proposes the use of a synthetic solid anolyte (SSA), constituted by agar, carbonaceous and nitrogen sources dissolved into diluted seawater. Results of a month-test showed the potential of the new SSA-MFC as a long lasting low energy consu...

  16. New insights in Microbial Fuel Cells: novel solid phase anolyte

    Science.gov (United States)

    Tommasi, Tonia; Salvador, Gian Paolo; Quaglio, Marzia

    2016-07-01

    For the development of long lasting portable microbial fuel cells (MFCs) new strategies are necessary to overcome critical issues such as hydraulic pump system and the biochemical substrate retrieval overtime to sustain bacteria metabolism. The present work proposes the use of a synthetic solid anolyte (SSA), constituted by agar, carbonaceous and nitrogen sources dissolved into diluted seawater. Results of a month-test showed the potential of the new SSA-MFC as a long lasting low energy consuming system.

  17. Direct MD simulation of liquid-solid phase equilibria for two-component plasmas

    OpenAIRE

    Schneider, A. S.; Hughto, J.; Horowitz, C. J.; Berry, D. K.

    2011-01-01

    We determine the liquid-solid phase diagram for carbon-oxygen and oxygen-selenium plasma mixtures using two-phase MD simulations. We identified liquid, solid, and interface regions using a bond angle metric. To study finite size effects, we perform 27648 and 55296 ion simulations. To help monitor non-equilibrium effects, we calculate diffusion constants $D_i$. For the carbon-oxygen system we find that $D_O$ for oxygen ions in the solid is much smaller than $D_C$ for carbon ions and that both ...

  18. Positronium in solid phases of n-alkane binary mixtures

    International Nuclear Information System (INIS)

    Highlights: • Rotator phase in even alkanes CnH2n+2 with n ⩽ 20 appears in mixed samples only. • Interlamellar gap width is the same for shorter chain alkane concentration x and 1 − x. • Excess electron trapping diminishes with broadening of alkane chain distribution Δn. - Abstract: Binary mixtures of even-numbered normal alkanes CnH2n+2 and Cn+2H2n+6 with n ⩽ 18 were investigated by positron annihilation spectroscopy. Formation of the rotator phase was observed in mixed structures, while no such a phase in neat alkanes in this range of n was found. Phase diagrams for n = 18 and n = 16 are very similar to the diagrams for binary mixtures of odd-numbered alkanes. The effect of positronium formation with trapped excess electrons weakens with decreasing n, at low n values the time constant of Ps rise contains the component much shorter than 1 h

  19. Research on the pattern of solid-liquid two-phase distribution in chemical process pump

    International Nuclear Information System (INIS)

    In order to explore the pattern of solid-liquid two-phase flow distribution in first stage of double-suction impeller and the double volute channel of the HD type petrol-chemical process pump, the flow field in double-suction impeller and double volute is simulated with the CFD software, by taking the Reynolds Averaged Navier Stokes equations as its governing equations, and the standard k-ε model for turbulence, derives the pattern of solid particle concentration distribution in the impeller and double volute channel under different initial particle concentrations and different particle diameters. The results show that in the double-suction impeller, solid phase distribution changes a lot along with the increase of initial particle concentration; the concentration near the back side is higher than the face side. Solid particles have the motion trend to the back side of blade in double-suction impeller along with the increase of particle diameters. In double volute channel, solid phase concentration distribution is uneven and solid particle concentration is relatively higher from section 1 to section 8. In the diffusion section, concentration is high in lateral side and low in medial side, the solid particles have the motion trend to the lateral side and the solid particle concentration is relatively higher.

  20. Application of nuclear techniques in two-phase liquid-solid particles hydrotransport investigations

    Directory of Open Access Journals (Sweden)

    Zych Marcin

    2016-01-01

    Full Text Available The paper presents gamma radiation application to two-phase flow investigation in a vertical pipeline, where the flow of solid particles transported by water was examined by use of both: radiotracers and gamma-absorption method. The simultaneous use of two methods allows analyzing of important parameters of solid particles hydrotransport. In the described experiments as solid phase the ceramic models representing natural polymetallic ocean nodules were used. Radiotracers allow to track the movements of selected models, representing specified grain size and the designation of its velocity. However gamma-absorption method enables measurement of average solid-phase velocity. For analysis of electrical signals obtained from scintillation detectors the cross-correlation method has been applied.

  1. Application of nuclear techniques in two-phase liquid-solid particles hydrotransport investigations

    Science.gov (United States)

    Zych, Marcin; Hanus, Robert; Vlasak, Pavel; Petryka, Leszek; Jaszczur, Marek

    2016-03-01

    The paper presents gamma radiation application to two-phase flow investigation in a vertical pipeline, where the flow of solid particles transported by water was examined by use of both: radiotracers and gamma-absorption method. The simultaneous use of two methods allows analyzing of important parameters of solid particles hydrotransport. In the described experiments as solid phase the ceramic models representing natural polymetallic ocean nodules were used. Radiotracers allow to track the movements of selected models, representing specified grain size and the designation of its velocity. However gamma-absorption method enables measurement of average solid-phase velocity. For analysis of electrical signals obtained from scintillation detectors the cross-correlation method has been applied.

  2. IMPROVED SUBGRID SCALE MODEL FOR DENSE TURBULENT SOLID-LIQUID TWO-PHASE FLOWS

    Institute of Scientific and Technical Information of China (English)

    TANG Xuelin; QIAN Zhongdong; WU Yulin

    2004-01-01

    The dense solid-phase governing equations for two-phase flows are obtained by using the kinetic theory of gas molecules. Assuming that the solid-phase velocity distributions obey the Maxwell equations, the collision term for particles under dense two-phase flow conditions is also derived.In comparison with the governing equations of a dilute two-phase flow, the solid-particle's governing equations are developed for a dense turbulent solid-liquid flow by adopting some relevant terms from the dilute two-phase governing equations. Based on Cauchy-Helmholtz theorem and Smagorinsky model,a second-order dynamic sub-grid-scale (SGS) model, in which the sub-grid-scale stress is a function of both the strain-rate tensor and the rotation-rate tensor, is proposed to model the two-phase governing equations by applying dimension analyses. Applying the SIMPLEC algorithm and staggering grid system to the two-phase discretized governing equations and employing the slip boundary conditions on the walls, the velocity and pressure fields, and the volumetric concentration are calculated. The simulation results are in a fairly good agreement with experimental data in two operating cases in a conduit with a rectangular cross-section and these comparisons imply that these models are practical.

  3. Study of solid solution strengthening of alloying element with phase structure factors

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Using the empirical electron theory of solids and molecules (EET), the phase structure factors, nA and nB, of the carbon-containing structural units with mass fraction of carbon (wC) below 0.8% and the mono-alloy structural units with wC at 0.2% in austenite and martensite are calculated. The solid solution strengthening brought by C-containing interstitial solid solution and alloy-substitutional solid solution in γ-Fe and α-Fe is discussed at electron structural level. The coefficient (s) of solid solution strengthening is advanced according to the bonding force between atoms. The study shows that when the criterion is applied to the carbonaceous or alloying element-containing solid solution the results of calculation will coincide with the experimental result very well.

  4. Detecting Lesch-Nyhan syndrome by solid phase primer extension

    Energy Technology Data Exchange (ETDEWEB)

    Shumaker, J.M.; Caskey, C.T. [Baylor College of Medicine, Houston, TX (United States); Metspalu, A.

    1994-09-01

    A mutation detection method based upon the wild type human HPRT sequence is presented for identification of Lesch Nyhan syndrome. The technique consists of performing a biotinlyated PCR amplification of the region of interest, followed by isolation and purification of single stranded template using magnetic separation. Allele-specific primers are annealed adjacent to the potential mutation site on the template. A terminal fluorescent deoxynucleotide addition is performed with a DNA template-dependent polymerase to distinguish between the mutant and wild-type sequence. The products are purified from unincorporated ddNTPs, eluted and finally analyzed on an ABI 373 to identify the mutation. The length of an extension primer is used as a position signature for mutations. The fidelity of nucleotide incorporation provides an excellent signal-to-noise ratio for the detection of nine HPRT mutations within eight cell lines. This method should detect all types of mutations except for repeated sequences that are longer than the primers. Moreover, the method is being extended to a solid support assay, whereby the extension primers are attached to a two-dimensional glass surface. Following extension, the solid support is analyzed for radioactive incorporation. We have shown the sequence determination of a five base region of a wild-type sequence and two different HPRT mutations. As more dense oligonucleotide arrays are produced, this method could be extended to sequence the complete coding region of HPRT.

  5. Practical solid and liquid phase markers for studying gastric emptying in man

    International Nuclear Information System (INIS)

    This paper presents a method used to evaluate solid and liquid phase markers for radionuclide gastric emptying studies. The authors conducted in vitro and in vivo comparative experiments employing several radiolabeled markers. Among the solid phase markers tested, Tc-99m-sulfur colloid in vivo-labeled liver and I-131-fiber performed optimally. However, Tc-99M sulfur colloid in scrambled egg showed very acceptable performance and it is significantly easier to prepare. Among liquid phase markers, they found In-111-DTPA stabilized with 1% albumin to be a good agent and appropriate for dual isotope emptying studies

  6. Solid-phase microextraction for bioconcentration studies according to OECD TG 305

    Energy Technology Data Exchange (ETDEWEB)

    Duering, Rolf-Alexander; Boehm, Leonard [Land Use and Nutrition (IFZ) Justus Liebig University Giessen, Institute of Soil Science and Soil Conservation, Research Centre for BioSystems, Giessen (Germany); Schlechtriem, Christian [Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Schmallenberg (Germany)

    2012-12-15

    An important aim of the European Community Regulation on chemicals and their safe use is the identification of (very) persistent, (very) bioaccumulative, and toxic substances. In other regulatory chemical safety assessments (pharmaceuticals, biocides, pesticides), the identification of such (very) persistent, (very) bioaccumulative, and toxic substances is of increasing importance. Solid-phase microextraction is especially capable of extracting total water concentrations as well as the freely dissolved fraction of analytes in the water phase, which is available for bioconcentration in fish. However, although already well established in environmental analyses to determine and quantify analytes mainly in aqueous matrices, solid-phase microextraction is still a rather unusual method in regulatory ecotoxicological research. Here, the potential benefits and drawbacks of solid-phase microextraction are discussed as an analytical routine approach for aquatic bioconcentration studies according to OECD TG 305, with a special focus on the testing of hydrophobic organic compounds characterized by log K{sub OW}> 5. (orig.)

  7. Influences of solid particles on the formation of the third phase crud during solvent extraction

    Institute of Scientific and Technical Information of China (English)

    ZHENG Qi; RUAN Renman; WEN Jiankang; SONG Yongsheng; DONG Qinghai; WU Minglin; YAO Guocheng

    2007-01-01

    The influences of solid particles in leach solution on the formation of the third phase crud during solvent extraction of copper were studied.Analyzed from the point of view of pH value and surface tension,the study results showed that the solid particle is one of the most important contributors for the formation of the third phase crud. During solvent extraction,if the pH value was greater than 2.30,the number of solid particles in the mother solution increased,in which case the possibility of forming the third phase crud could also increase,and the interface tension value might grow in pace with the quantity of the third phase crud.

  8. Stability of phases in (Ba, Gd)MnO3 solid solution system

    Institute of Scientific and Technical Information of China (English)

    Migaku Kobayashi; Hidenori Tamura; Hiromi Nakano; Hirohisa Satoh; Naoki Kamegashira

    2008-01-01

    The existing phases in BaxGd1-xMnO3 solid solution system (0≦x≦1) were studied by analyzing the detailed crystal structure of each composition from the results of the Rietveld method using powder X-ray diffraction data. For a small substitution of Ba for Gd (0≦x<0.1), the orthorhombic phase with a perovskite type structure (Pnma space group) was stably formed and this fact was supported by the electron diffraction data. There existed an intermediate phase of Ba0.33Gd0.67MnO3, which was characterized as the tetragonal phase with perovskite structure. The composition range of this phase was narrow and almost line compound. Between the regions of these phases, there existed two-phase region. There was also a two-phase region between the intermediate tetragonal phase and BaMnO3. Measurement of electrical conductivities of these orthorhombic solid solutions and tetragonal phases showed semiconducting behaviors for both phases and the existence of the phase transition at high temperature for the orthorhombic phase. The transition temperature decreased as the Ba content increased.

  9. Positronium in solid phases of n-alkane binary mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Zgardzińska, B.; Goworek, T.

    2015-09-08

    Highlights: • Rotator phase in even alkanes C{sub n}H{sub 2n+2} with n ⩽ 20 appears in mixed samples only. • Interlamellar gap width is the same for shorter chain alkane concentration x and 1 − x. • Excess electron trapping diminishes with broadening of alkane chain distribution Δn. - Abstract: Binary mixtures of even-numbered normal alkanes C{sub n}H{sub 2n+2} and C{sub n+2}H{sub 2n+6} with n ⩽ 18 were investigated by positron annihilation spectroscopy. Formation of the rotator phase was observed in mixed structures, while no such a phase in neat alkanes in this range of n was found. Phase diagrams for n = 18 and n = 16 are very similar to the diagrams for binary mixtures of odd-numbered alkanes. The effect of positronium formation with trapped excess electrons weakens with decreasing n, at low n values the time constant of Ps rise contains the component much shorter than 1 h.

  10. Liquid-solid phase transitions in a deformable container

    Czech Academy of Sciences Publication Activity Database

    Krejčí, Pavel; Rocca, E.; Sprekels, J.

    1. Berlin: Springer, 2010 - (Albers, B.), s. 285-300 ISBN 978-3-642-11444-1 Institutional research plan: CEZ:AV0Z10190503 Keywords : phase transition * energy balance * equilibrium state Subject RIV: BA - General Mathematics http://link.springer.com/chapter/10.1007%2F978-3-642-11445-8_22

  11. Flow characteristics of gas-liquid-solid three-phase bubbly flow in vertical pipes

    International Nuclear Information System (INIS)

    The volumetric fractions of each phase in air-water-particle three-phase bubbly flows were measured in vertical pipes of about 10 m in height, and of 20.9, 30.8 and 50.4 mm inside diameter, respectively. The solid particles used in this experiment were three kinds of spherical particles of 1.15, 2.56 and 4.16 mm mean diameter, made of aluminum ceramics with 2270-2400 kg/m3 density. Characteristics of the volumetric fractions of each phase were discussed in this experimental range, especially on the effects of the volumetric flux of each phase, pipe diameter and mean particle diameter. Then, empirical correlations of the volumetric fractions of each phase were proposed. The present empirical correlations would be useful as constitutive equations required to analyze the gas-liquid-solid three-phase bubbly flow in vertical pipes based on the slip flow model. (author)

  12. Solid phase stability of molybdenum under compression: Sound velocity measurements and first-principles calculations

    International Nuclear Information System (INIS)

    The high-pressure solid phase stability of molybdenum (Mo) has been the center of a long-standing controversy on its high-pressure melting. In this work, experimental and theoretical researches have been conducted to check its solid phase stability under compression. First, we performed sound velocity measurements from 38 to 160 GPa using the two-stage light gas gun and explosive loading in backward- and forward-impact geometries, along with the high-precision velocity interferometry. From the sound velocities, we found no solid-solid phase transition in Mo before shock melting, which does not support the previous solid-solid phase transition conclusion inferred from the sharp drops of the longitudinal sound velocity [Hixson et al., Phys. Rev. Lett. 62, 637 (1989)]. Then, we searched its structures globally using the multi-algorithm collaborative crystal structure prediction technique combined with the density functional theory. By comparing the enthalpies of body centered cubic structure with those of the metastable structures, we found that bcc is the most stable structure in the range of 0–300 GPa. The present theoretical results together with previous ones greatly support our experimental conclusions

  13. Theoretical study on phase coexistence in ferroelectric solid solutions near the tricritical point

    International Nuclear Information System (INIS)

    Phase coexistence in ferroelectric solid solutions near the tricritical point has been theoretically analyzed by using the Landau-Devonshire theory. Results revealed that different phases having similar potential wells could coexist in a narrow composition range near the tricritical point in the classical Pb(Zr1−xTix)O3 system. The potential barrier between potential wells increases with the decrease of temperature. Coexisting phases or different domains of the same phase can produce adaptive strains to maintain atomic coherency at the interfaces or domain walls. Such compatibility strains have influence on the energy potential as well as the stability of relative phases, leading to the appearance of energetically unfavorable monoclinic phases. Those competing and coexisting phases also construct an easy phase transition path with small energy barrier in between, so that very small stimuli can produce large response in compositions near the morphotropic phase boundary, especially near the tricritical point

  14. Theoretical study on phase coexistence in ferroelectric solid solutions near the tricritical point

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xiaoyan, E-mail: luxy@hit.edu.cn, E-mail: dzk@psu.edu; Li, Hui [Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education, School of Civil Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zheng, Limei [Condensed Matter Science and Technology Institute, Harbin Institute of Technology, Harbin 150001 (China); Cao, Wenwu [Condensed Matter Science and Technology Institute, Harbin Institute of Technology, Harbin 150001 (China); Department of Mathematics and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

    2015-04-07

    Phase coexistence in ferroelectric solid solutions near the tricritical point has been theoretically analyzed by using the Landau-Devonshire theory. Results revealed that different phases having similar potential wells could coexist in a narrow composition range near the tricritical point in the classical Pb(Zr{sub 1−x}Ti{sub x})O{sub 3} system. The potential barrier between potential wells increases with the decrease of temperature. Coexisting phases or different domains of the same phase can produce adaptive strains to maintain atomic coherency at the interfaces or domain walls. Such compatibility strains have influence on the energy potential as well as the stability of relative phases, leading to the appearance of energetically unfavorable monoclinic phases. Those competing and coexisting phases also construct an easy phase transition path with small energy barrier in between, so that very small stimuli can produce large response in compositions near the morphotropic phase boundary, especially near the tricritical point.

  15. Isostructural solid-solid phase transition in monolayers of soft core-shell particles at fluid interfaces: structure and mechanics.

    Science.gov (United States)

    Rey, Marcel; Fernández-Rodríguez, Miguel Ángel; Steinacher, Mathias; Scheidegger, Laura; Geisel, Karen; Richtering, Walter; Squires, Todd M; Isa, Lucio

    2016-04-13

    We have studied the complete two-dimensional phase diagram of a core-shell microgel-laden fluid interface by synchronizing its compression with the deposition of the interfacial monolayer. Applying a new protocol, different positions on the substrate correspond to different values of the monolayer surface pressure and specific area. Analyzing the microstructure of the deposited monolayers, we discovered an isostructural solid-solid phase transition between two crystalline phases with the same hexagonal symmetry, but with two different lattice constants. The two phases corresponded to shell-shell and core-core inter-particle contacts, respectively; with increasing surface pressure the former mechanically failed enabling the particle cores to come into contact. In the phase-transition region, clusters of particles in core-core contacts nucleate, melting the surrounding shell-shell crystal, until the whole monolayer moves into the second phase. We furthermore measured the interfacial rheology of the monolayers as a function of the surface pressure using an interfacial microdisk rheometer. The interfaces always showed a strong elastic response, with a dip in the shear elastic modulus in correspondence with the melting of the shell-shell phase, followed by a steep increase upon the formation of a percolating network of the core-core contacts. These results demonstrate that the core-shell nature of the particles leads to a rich mechanical and structural behavior that can be externally tuned by compressing the interface, indicating new routes for applications, e.g. in surface patterning or emulsion stabilization. PMID:26948023

  16. Predicting phase transition pressure in solids:a semiclasical possibility

    OpenAIRE

    Celebonovic, V.

    1999-01-01

    This is a short review of the physical ideas,algorithm for the calculation of the phase transition pressure and some results of a semi-classical theory of the behaviour of materials under high pressure proposed by P.Savic and R.Kasanin.It is base on the Coulomb interaction,supplemented by a microscopic selection rule and a set of experimentally founded postulates,and it has found applications from DAC experiments to planetary structure modelling.

  17. The synthesis and properties of the phases obtained by solid-solid reactions

    Directory of Open Access Journals (Sweden)

    Blonska-Tabero A.

    2008-01-01

    Full Text Available The presented work encompasses the subject of the studies and the results obtained over the last years by the research workers of the Department of Inorganic Chemistry. They include mainly the studies on the reactivity of metal oxides, searching for new phases in binary and ternary systems of metal oxides as well as describing phase relations establishing in such systems. They also encompass works on the extensive characteristics of physico-chemical properties of the newly obtained compounds.

  18. Solid phosphorus phase in aluminum- and iron-treated biosolids.

    Science.gov (United States)

    Huang, Xiao-Lan; Chen, Yona; Shenker, Moshe

    2007-01-01

    Stabilization of phosphorus (P) in sewage sludge (biosolids) to reduce water-soluble P concentrations is essential for minimizing P loss from amended soils and maximizing the capacity of the soil to safely serve as an outlet for this waste material. The chemical form at which P is retained in biosolids stabilized by Al(2)(SO(4))(3) x 18H(2)O (alum) or FeSO(4) x 7H(2)O (FeSul) was investigated by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray elemental spectrometry (EDXS) and by X-ray diffraction (XRD). Both treatments resulted in the formation of a Ca-P phase, probably brushite. Phosphorus was further retained in the alum-treated biosolids by precipitation of an Al-P phase with an Al/P molar ratio of about 1:1, while in the FeSul-treated biosolids, P was retained by both precipitation with Fe/P molar ratios of 1:1 or 1.5:1, and by adsorption onto newly formed Fe hydroxides exhibiting an Fe/P molar ratio of up to 11:1. All of these mechanisms efficiently reduced P solubility and are crucial in biosolids environmentally safe agronomic beneficial use for this waste product; however, each P phase formed may react differently in the amended soil, depending on soil properties. Thus, the proper P stabilization method would depend on the target soil. PMID:17332259

  19. Effect of temperature on the solubility and solid phase stability of zirconium hydroxide

    International Nuclear Information System (INIS)

    The solubility and solid phase stability of zirconium hydroxide was investigated in the acidic pH range after heating the aqueous samples at 50, 70 and 90 C. The solubility measured at room temperature after exposing the batch samples to elevated temperatures for a given period of time significantly decreased with increasing heating periods. The Zr concentrations at given pH after heating at 90 C for 3 weeks are about 5 orders of magnitude lower than the solubility of amorphous zirconium hydroxide (Zr(OH)4(am)) kept at room temperature. Size distributions of the Zr colloidal species after heating were investigated by sequential filtration using different pore-sized membranes, and the contribution of the colloidal species to the solubility was assessed. The TEM images and XRD spectra of the solid phases after heating indicated the agglomeration and crystallization of the initial amorphous hydroxide solid phase. The solid phase was identified as crystalline oxide after heating at 90 C. The solubility product determined from the solubility data excluding contributions of colloidal species is correlated to the particle size of the solid phase. (orig.)

  20. Enhanced denitrification of Pseudomonas stutzeri by a bioelectrochemical system assisted with solid-phase humin.

    Science.gov (United States)

    Xiao, Zhixing; Awata, Takanori; Zhang, Dongdong; Zhang, Chunfang; Li, Zhiling; Katayama, Arata

    2016-07-01

    The denitrification reactions performed by Pseudomonas stutzeri JCM20778 were enhanced electrochemically with the use of solid-phase humin, although P. stutzeri itself was incapable of receiving electrons directly from the graphite electrode. Electrochemically reduced humin enhanced the microbial, but not abiotic, denitrification reactions. Electric current and cyclic voltammetry analyses suggested that the solid-phase humin functioned as an electron donor for the denitrification reactions of P. stutzeri. Nitrogen balance study and the estimation of the first-order rate constants of the consecutive denitrification reactions suggested that the solid-phase humin enhanced all reducing reactions from nitrate to nitrogen gas. Considering the wide distribution of humin in the environment, the findings that solid-phase humin can assist in electron transfer, from the electrode to a denitrifying bacterium that has little ability to directly utilize external electrons, has important implications for the widespread application of bioelectrochemical systems assisted by solid-phase humin for enhancing microbial denitrification. PMID:26905325

  1. Biogas production from municipal solid wastes using an integrated rotary drum and anaerobic-phased solids digester system.

    Science.gov (United States)

    Zhu, Baoning; Zhang, Ruihong; Gikas, Petros; Rapport, Joshua; Jenkins, Bryan; Li, Xiujin

    2010-08-01

    This research was conducted to develop an integrated rotary drum reactor (RDR)-anaerobic-phased solids (APS) digester system for the treatment of municipal solid waste (MSW) to produce biogas energy and achieve waste reduction. A commercial RDR facility was used to provide a 3-d pretreatment and sufficient separation of the organics from MSW and then the organics were digested in a laboratory APS-digester system for biogas production. The organics generated from the RDR contained 50% total solids (TS) and 36% volatile solids (VS) on wet basis. The APS-digester was started at an organic loading rate (OLR) of 3.1 gVS L(-1) d(-1) and operated at three higher OLRs of 4.6, 7.7 and 9.2 gVS L(-1) d(-1). At the OLR of 9.2 gVS L(-1) d(-1) the system biogas production rate was 3.5 L L(-1) d(-1) and the biogas and methane yields were 0.38 and 0.19 L gVS(-1), respectively. Anaerobic digestion resulted in 38% TS reduction and 53% VS reduction in the organic solids. It was found that the total VFA concentration reached a peak value of 15,000 mg L(-1) as acetic acid in the first 3d of batch digestion and later decreased to about 500 mg L(-1). The APS-digester system remained stable at each OLRs for over 100d with the pH in the hydrolysis reactors in the range of 7.3-7.8 and the pH in the biogasification reactor in 7.9-8.1. The residual solids after the digestion had a high heating value of 14.7 kJ gTS(-1). PMID:20409703

  2. Numerical simulation of gas–liquid–solid three-phase flow using particle methods

    International Nuclear Information System (INIS)

    We want to simulate, based on particle methods, the dynamic behavior of multi-phase flows in a gas–solid–liquid mixture system. With the governing equations discretized within the finite volume particle method, the effects of contact and collision between solid particles were modeled by the distinct element method. Applicability of the viscosity model and an empirical drag force model were confirmed for the hydrodynamic interactions between solid particles and fluid. Simulations were performed of a single bubble rising in a tank of stagnant solid particle–liquid. The results for the dynamic behavior indicate that the present computational framework of particle-based simulation method may be useful for numerical simulations of multi-phase flow behavior in a solid particle–fluid mixture system. (author)

  3. Crystalline-to-plastic phase transitions in molecularly thin n-dotriacontane films adsorbed on solid surfaces

    DEFF Research Database (Denmark)

    Cisternas, Edgardo; Corrales, T. P.; del Campo, V.;

    2009-01-01

    identify with a solid-solid phase transition. At higher coverages, we observed additional steps in the ellipsometric signal that we identify with a solid-solid phase transition in multilayer islands (similar to 333 K) and with the transition to the rotator phase in bulk crystallites (similar to 337 K......), respectively. After considering three alternative explanations, we propose that the step upward in the ellipsometric signal observed at similar to 331 K on heating the submonolayer film is the signature of a transition from a perpendicular monolayer phase to a denser phase in which the alkane chains contain on...

  4. Etching and forward transfer of fused silica in solid-phase by femtosecond laser-induced solid etching (LISE)

    International Nuclear Information System (INIS)

    We present a femtosecond laser-based technique for etching and forward transfer of bulk transparent materials in solid-phase. Femtosecond laser pulses with λ=800 nm were focused through a fused silica block onto an absorbing thin film of Cr. A constraining Si wafer was pressed into tight contact with the Cr film to prevent lift-off of the film. A combination of the high temperature and pressure of the Cr, and compressive stress from the Si, resulted in etching of smooth features from the fused silica by cracking. Unlike in conventional ablative or chemical etching, the silica was removed from the bulk as single solid-phase pieces which could be collected on the Si. Using this so-called laser-induced solid etching (LISE) technique, 1-2 μm deep pits and channels have been produced in the silica surface, and corresponding dots and lines deposited on the Si. The threshold fluence for etching was found to be ∼0.4J/cm2 with ∼130 fs duration pulses. The morphology of the etched features are investigated as functions of fluence and exposure to multiple pulses.

  5. The study of solid phase removal from water using magnetite particles

    OpenAIRE

    Радовенчик, В. М.; Радовенчик, Я. В.

    2014-01-01

    The results of research of the water treatment method effectiveness using high-dispersion magnetite particles were given. It was found that the treatment of wastewater after wastepaper recycling process, which contains a wide range of solid pollutants, using only the magnetite particles was ineffective. The pH adjustment can decrease residual content of solid phase in the treated water but it prevents reuse of such water. Best results can be obtained using additional reagents. Top coagulant e...

  6. Determination of Atrazine, Acetochlor, Clomazone, Pendimethalin and Oxyfluorfen in Soil by a Solid Phase Microextraction Method

    OpenAIRE

    Rada Đurović; Jelena Gajić-Umiljendić; Tijana Đorđević

    2008-01-01

    A solid phase microextraction (SPME) method for simultaneous determination of atrazine, acetochlor, clomazone, pendimethalin and oxyfluorfen in soil samples was developed. The method is based on a combination of conventional liquid-solid procedure and a following SPME determination of the selected pesticides. Initially, various microextraction conditions, such as the fibre type, desorption temperature and time, extraction time and NaCl content, were investigated and optimized. Then, extractio...

  7. Solid-Phase Synthesis of Modified Peptides as Putative Inhibitors of Histone Modifying Enzymes

    DEFF Research Database (Denmark)

    Cohrt, Anders Emil O'Hanlon

    for the solid-phase synthesis of thiourea- and guanidinemodified peptides are presented. By activating N,N ’-di-Boc-thiourea with Mukaiyama’s reagent or HgCl2, the N -terminal of solid-supported peptides could be cleanly converted into the corresponding thiourea or guanidine derivative. The reactions...... strategy was employed in the identification of individual library members. Changes in the acetylation pattern could also be detecting using a quantitative ninhydrin assay....

  8. Mixed Model for Silt-Laden Solid-Liquid Two-Phase Flows

    Institute of Scientific and Technical Information of China (English)

    唐学林; 徐宇; 吴玉林

    2003-01-01

    The kinetic theory of molecular gases was used to derive the governing equations for dense solid-liquid two-phase flows from a microscopic flow characteristics viewpoint by multiplying the Boltzmann equation for each phase by property parameters and integrating over the velocity space. The particle collision term was derived from microscopic terms by comparison with dilute two-phase flow but with consideration of the collisions between particles for dense two-phase flow conditions and by assuming that the particle-phase velocity distribution obeys the Maxwell equations. Appropriate terms from the dilute two-phase governing equations were combined with the dense particle collision term to develop the governing equations for dense solid-liquid turbulent flows. The SIMPLEC algorithm and a staggered grid system were used to solve the discretized two-phase governing equations with a Reynolds averaged turbulence model. Dense solid-liquid turbulent two-phase flows were simulated for flow in a duct. The simulation results agree well with experimental data.

  9. Biological nitrate removal from water and wastewater by solid-phase denitrification process.

    Science.gov (United States)

    Wang, Jianlong; Chu, Libing

    2016-11-01

    Nitrate pollution in receiving waters has become a serious issue worldwide. Solid-phase denitrification process is an emerging technology, which has received increasing attention in recent years. It uses biodegradable polymers as both the carbon source and biofilm carrier for denitrifying microorganisms. A vast array of natural and synthetic biopolymers, including woodchips, sawdust, straw, cotton, maize cobs, seaweed, bark, polyhydroxyalkanoate (PHA), polycaprolactone (PCL), polybutylene succinate (PBS) and polylactic acid (PLA), have been widely used for denitrification due to their good performance, low cost and large available quantities. This paper presents an overview on the application of solid-phase denitrification in nitrate removal from drinking water, groundwater, aquaculture wastewater, the secondary effluent and wastewater with low C/N ratio. The types of solid carbon source, the influencing factors, the microbial community of biofilm attached on the biodegradable carriers, the potential adverse effect, and the cost of denitrification process are introduced and evaluated. Woodchips and polycaprolactone are the popular and competitive natural plant-like and synthetic biodegradable polymers used for denitrification, respectively. Most of the denitrifiers reported in solid-phase denitrification affiliated to the family Comamonadaceae in the class Betaproteobacteria. The members of genera Diaphorobacter, Acidovorax and Simplicispira were mostly reported. In future study, more attention should be paid to the simultaneous removal of nitrate and toxic organic contaminants such as pesticide and PPCPs by solid-phase denitrification, to the elucidation of the metabolic and regulatory relationship between decomposition of solid carbon source and denitrification, and to the post-treatment of the municipal secondary effluent. Solid-phase denitrification process is a promising technology for the removal of nitrate from water and wastewater. PMID:27396522

  10. Phosphorus Sorption and Redistribution on Soil Solid Phase in a Brazilian Haplorthox Amended with Bio solids

    International Nuclear Information System (INIS)

    Land application of bio solids (SS) can cause a buildup of phosphorus (P) in the top soil. The changes in the soil P characteristics may be assessed by the sorption isotherm and the sequential fractionation techniques. Samples of Haplorthox were collected from a field experiment where maize was cultivated for two years, after two applications of SS originated from two cities of San Paulo State, Brazil. SS applications added a total of 125, 250, 500, 1000 and 2000 kg ha-1 of P in the area. To perform the sorption isotherms and obtain P maximum sorption capacity (Omax) and the binding energy, soil samples were submitted to increasing P concentration solutions until equilibrium was reached. Sequential fractionation was done by a sequential extraction with CaCl2, NaHCO3, NaOH, HCl, and HNO3 + HClO4 (residual). Addition of bio solids from both cities to the soil decreased Qmax and the binding energy obtained by the Langmuir equation. SS additions changed the P fractions distribution in the soil by increasing the labile fractions (P-CaCl2 and P-NaHCO3) and the moderately labile fraction (P-NaOH) by 11.2% and 20.3%, respectively, in detriment of the most resistant P fraction

  11. The use of coal in a solid phase reduction of iron oxide

    Science.gov (United States)

    Nokhrina, O. I.; Rozhihina, I. D.; Hodosov, I. E.

    2015-09-01

    The results of the research process of producing metalized products by solid-phase reduction of iron using solid carbonaceous reducing agents. Thermodynamic modeling was carried out on the model of the unit the Fe-C-O and system with iron ore and coal. As a result of modeling the thermodynamic boundary reducing, oxidizing, and transition areas and the value of the ratio of carbon and oxygen in the system. Simulation of real systems carried out with the gas phase obtained in the pyrolys of coal. The simulation results allow to determine the optimal cost of coal required for complete reduction of iron ore from a given composition. The kinetics of the processes of solid-phase reduction of iron using coal of various technological brands.

  12. Development and Optimization of Sepharose Solid Phase Radioimmunoassay for Estimation of Thyroid Stimulating Hormone

    International Nuclear Information System (INIS)

    The aim of the present study was oriented to develop, optimize and validate solid phase radioimmunoassay, through many studies on Sepharose, for estimation of thyroid stimulating hormone in humane serum. Preparation of polyclonal antibodies was carried out in host rabbit animals against TSH antigen followed by partial purification of 1gG. Linkage of antibody 1gG to activated Sepharose CL-4B was carried out after activation of Sepharose with 1,1- carbonyldiimidazole. Labeling of TSH was carried out using chloramine-T as an oxidizing agent and the labeled tracer was purified through PD-10 column. Extensive studies were carried out to obtain the optimum conditions of using solid phase Sepharose to reach higher separation efficiency. The results of validation tests reveal that the local solid phase system is precise and accurate for evaluation of thyroid disorders

  13. Solid-phase route to Fmoc-protected cationic amino acid building blocks

    DEFF Research Database (Denmark)

    Clausen, Jacob Dahlqvist; Linderoth, Lars; Nielsen, Hanne Mørck;

    2012-01-01

    Diamino acids are commonly found in bioactive compounds, yet only few are commercially available as building blocks for solid-phase peptide synthesis. In the present work a convenient, inexpensive route to multiple-charged amino acid building blocks with varying degree of hydrophobicity was...... developed. A versatile solid-phase protocol leading to selectively protected amino alcohol intermediates was followed by oxidation to yield the desired di- or polycationic amino acid building blocks in gram-scale amounts. The synthetic sequence comprises loading of (S)-1-(p-nosyl)aziridine-2-methanol onto a...... simple neutral amino acids as well as analogs displaying high bulkiness or polycationic side chains was prepared. Two building blocks were incorporated into peptide sequences using microwave-assisted solid-phase peptide synthesis confirming their general utility....

  14. NASA satellite communications application research. Phase 2: Efficient high power, solid state amplifier for EFH communications

    Science.gov (United States)

    Benet, James

    1993-01-01

    The final report describes the work performed from 9 Jun. 1992 to 31 Jul. 1993 on the NASA Satellite Communications Application Research (SCAR) Phase 2 program, Efficient High Power, Solid State Amplifier for EHF Communications. The purpose of the program was to demonstrate the feasibility of high-efficiency, high-power, EHF solid state amplifiers that are smaller, lighter, more efficient, and less costly than existing traveling wave tube (TWT) amplifiers by combining the output power from up to several hundred solid state amplifiers using a unique orthomode spatial power combiner (OSPC).

  15. Extraction of Pb2+ using Silica from Rice Husks Ash (RHA – Chitosan as Solid Phase

    Directory of Open Access Journals (Sweden)

    Hanandayu Widwiastuti

    2013-03-01

    Full Text Available The existence of lead (Pb compounds in waters can be caused of waste pollution from industrial activities such as dye and battery industries. Lead has toxic characteristic and is able to causing deseases. The levels of Cr(VI can be decreased by methods such as electroplating, oxidation, reduction, and membrane separation. But this methods require high cost and produce a lot of waste. Furthermore, those methods cannot determine the small concentration of Pb2+. Therefore, solid phase extraction is used because it’s a simple method and can be used to preconcentrate Pb2+ ion. The aim of this study is to create solid phase from nature material as an alternative method to determine Pb2+ in water samples. The solid phase is silica from rice husks ash (RHA that was modified using chitosan. To achieve that aim, the optimization of silica : chitosan composition was done. The influence of Pb2+ concentration and citric acid concentration was studied to obtain optimum recovery of Pb2+. Interaction between Pb2+ ion and solid phase silica – chitosan could be estimated based on the result. The result showed the optimum composition of silica : chitosan is 65% silica : 35% chitosan with Cation Exchange Capacity (CEC 0.00455 mek/g. Mass Adsorbed Pb2+for 1 g silica : chitosan 65% is 9.715 mg/g. Optimum recovery of Pb2+ on solid phase extraction is reached at concentration of Pb2+ 10 ppm and citric acid concentration 0.05 M (88.25 % and 81.18 %. This result showed that solid phase extraction using silica – chitosan can be used as an alternative method to determine Pb2+ in water.

  16. Binary Solid-Liquid Phase Diagram of Phenol and t-Butanol: An Undergraduate Physical Chemistry Experiment

    Science.gov (United States)

    Xu, Xinhua; Wang, Xiaogang; Wu, Meifen

    2014-01-01

    The determination of the solid-liquid phase diagram of a binary system is always used as an experiment in the undergraduate physical chemistry laboratory courses. However, most phase diagrams investigated in the lab are simple eutectic ones, despite the fact that complex binary solid-liquid phase diagrams are more common. In this article, the…

  17. Oxygen mass transfer in a high solids loading three-phase internal-loop airlift reactor

    OpenAIRE

    Freitas, Carla Maria Duarte de; Teixeira, J.A.

    2001-01-01

    Determinations of volumetric mass transfer coefficient were conducted in a three-phase internal-loop airlift reactor with an enlarged degassing zone. The effect of parameters such as the airflow rate (riser superficial gas velocities between 0.01 and 0.5 m/s), solids loading (up to 30%, v/v), solids density (1023 and 1048 kg/m3) and the liquid-phase properties on kLa was studied. It was observed that the increase of the airflow rate and the introduction of ethanol enhanced the volume...

  18. Solid-Phase Synthetic Route to Multiple Derivatives of a Fundamental Peptide Unit

    Directory of Open Access Journals (Sweden)

    Martin J. O’Donnell

    2010-07-01

    Full Text Available Amino acids are Nature’s combinatorial building blocks. When substituted on both the amino and carboxyl sides they become the basic scaffold present in all peptides and proteins. We report a solid-phase synthetic route to large combinatorial variations of this fundamental scaffold, extending the variety of substituted biomimetic molecules available to successfully implement the Distributed Drug Discovery (D3 project. In a single solid-phase sequence, compatible with basic amine substituents, three-point variation is performed at the amino acid a-carbon and the amino and carboxyl functionalities.

  19. Characteristics of temporal- spatial parameters in quasi- solid-fluid phase transition of granular materials

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The quasi-solid-fluid phase transition of granular materials is closely related to the shear rate and solid concentration in addition to their intrinsic properties. The contact duration and the coordination number are two important temporal-spatial parameters to describe the granular interaction in phase transition. In this study, characteristics of the contact duration and the coordination number associated with the transition processes are determined using a 3D discrete element model under different shear rates and concentrations. The resulting macroscopic stress and strain-rate relations are discussed. The temporal and spatial parameters provide a linkage between the macroscopic constitutive law and inter- particle micromechanics.

  20. Differing results of direct and indirect solid phase radioimmunoassay for HBsAg in acute hepatitis

    International Nuclear Information System (INIS)

    In 54 patients suffering from active viral hepatitis the indirect solid phase radioimmunoassay (ind-SPRIA) for HBsAg was positive in 9 cases the direct solid phase radioimmunoassay (d-SPRIA) being negative. In 2 further cases ind-SPRIA was positive during several weeks but d-SPRIA only once. AntiHBc could be detected in 9 of these patients. In 7 patients the usual decrease of the transaminase activity was followed by a second elavation with prolongation of the disease. The unknown factor detected by ind-SPRIA suggests a special of acute hepatitis. (orig.)

  1. Solid-Phase Spectrophotometric Analysis of 1-Naphthol Using Silica Functionalized with m-Diazophenylarsonic Acid.

    Science.gov (United States)

    Zaitseva, Nataliya; Alekseev, Sergei; Zaitsev, Vladimir; Raks, Viktoria

    2016-12-01

    The m-aminophenylarsonic acid (m-APAA) was immobilized onto the silica gel surface with covalently grafted quaternary ammonium groups via ion exchange. The diazotization of ion-bonded m-APAA resulted in a new solid-phase spectrophotometric reagent for detection of 1-naphtol in environmental water samples. The procedure of solid-phase spectrophotometric analysis is characterized by 20 μg L(-1) limit of detection (LOD) of 1-naphtol, up to 2000 concentration factor, and insensitivity to the presence of natural water components as well as to 30-fold excess of phenol, resorcinol, and catechol. PMID:26979727

  2. Solid-Phase Spectrophotometric Analysis of 1-Naphthol Using Silica Functionalized with m-Diazophenylarsonic Acid

    Science.gov (United States)

    Zaitseva, Nataliya; Alekseev, Sergei; Zaitsev, Vladimir; Raks, Viktoria

    2016-03-01

    The m-aminophenylarsonic acid (m-APAA) was immobilized onto the silica gel surface with covalently grafted quaternary ammonium groups via ion exchange. The diazotization of ion-bonded m-APAA resulted in a new solid-phase spectrophotometric reagent for detection of 1-naphtol in environmental water samples. The procedure of solid-phase spectrophotometric analysis is characterized by 20 μg L-1 limit of detection (LOD) of 1-naphtol, up to 2000 concentration factor, and insensitivity to the presence of natural water components as well as to 30-fold excess of phenol, resorcinol, and catechol.

  3. A Photolabile Linker for the Solid-Phase Synthesis of Peptide Hydrazides and Heterocycles

    DEFF Research Database (Denmark)

    Qvortrup, Katrine; Komnatnyy, Vitaly V.; Nielsen, Thomas Eiland

    2014-01-01

    A photolabile hydrazine linker for the solid-phase synthesis of peptide hydrazides and hydrazine-derived heterocycles is presented. The developed protocols enable the efficient synthesis of structurally diverse peptide hydrazides derived from the standard amino adds, including those with side......-chain protected residues at the C-terminal of the resulting peptide hydrazide, and are useful for the synthesis of dihydropyrano[2,3-c]pyrazoles. The linker is compatible with most commonly used coupling reagents and protecting groups for solid-phase peptide synthesis....

  4. Holmium redistribution during solid phase epitaxial crystallization in amorphized silicon layers

    International Nuclear Information System (INIS)

    The concentration profiles of holmium were studied after annealing of silicon layers at 620 deg C. Silicon was implanted with Ho+ ions at 1 MeV energy and (1-3) · 1014 cm-2 doses. Recrystallization of amorphized silicon layer occurs by the mechanism of the solid phase epitaxy. The regularities of segregation redistribution of Ho impurity are similar to the Er redistribution regularities studied earlier. A decrease of Ho concentration at the initial stage of solid phase epitaxial recrystallization is due to a low velocity of mass transport through the crystal-amorphous interface

  5. Detection of ibuprofen and ciprofloxacin by solid-phase extraction and UV/Vis spectroscopy

    Science.gov (United States)

    Zhou, Zhengwei; Jiang, Jia Qian

    2012-07-01

    A simple and economic solid-phase extraction coupled with UV/Vis spectrophotometric method is described for the analysis of ibuprofen and ciprofloxacin. Following solid-phase extraction from model wastewater samples containing standard ibuprofen or ciprofloxacin, elutes were analyzed by a UV/Vis spectrophotometer at 225 nm for ibuprofen and 280 nm for ciprofloxacin. The assay was linear for both compounds with good coefficients of correlation. This method shows good recoveries for both compounds with 101.0 ± 9.8% for ibuprofen and 99.4 ± 11.8% ciprofloxacin.

  6. Synthesis of a Small Library of Imidazolidin-2-ones using Gold Catalysis on Solid Phase.

    Science.gov (United States)

    La-Venia, Agustina; Medran, Noelia S; Krchňák, Viktor; Testero, Sebastián A

    2016-08-01

    An efficient and high-yielding solid phase synthesis of a small library of imidazolidin-2-ones and imidazol-2-ones was carried out employing a high chemo- and regioselective gold-catalyzed cycloisomerization as a key step. Polymer-supported amino acids derivatized with several alkyne functionalities combined with tosyl- and phenylureas have been subjected to gold-catalysis exhibiting exclusively C-N bond formation. The present work proves the potential of solid phase synthesis and homogeneous gold catalysis as an efficient and powerful synthetic tool for the generation of drug-like heterocycles. PMID:27337593

  7. 2,6-Diketopiperazines from amino acids, from solution-phase to solid-phase organic synthesis.

    Science.gov (United States)

    Perrotta, E; Altamura, M; Barani, T; Bindi, S; Giannotti, D; Harmat, N J; Nannicini, R; Maggi, C A

    2001-01-01

    A method to prepare 1,3-disubstituted 2,6-diketopiperazines (2,6-DKP) as useful heterocyclic library scaffolds in the search of new leads for drug discovery is described. The method can be used in solution-phase and solid-phase conditions. In the key step of the synthesis, the imido portion of the new molecule is formed in solution through intramolecular cyclization, under basic conditions, of a secondary amide nitrogen on a benzyl ester. A Wang resin carboxylic ester is used as the acylating agent under solid-phase conditions, allowing the cyclization to take place with simultaneous cleavage of the product from the resin ("cyclocleavage"). The synthetic method worked well with several couples of amino acids, independently from their configuration, and was used for the parallel synthesis of a series of fully characterized compounds. The use of iterative conditions in the solid phase (repeated addition of fresh solvent and potassium carbonate to the resin after filtering out the product-containing solution) allowed us to keep diastereoisomer content below the detection limit by HPLC and (1)H NMR (200 MHz). PMID:11549363

  8. Novel functionalized polymeric fabric and fiber material as solid support for solid-phase synthesis and biomedical applications

    Science.gov (United States)

    Xiang, Bei

    The aim of the research is to develop novel polymer solid support by modifying or fabricating polymeric fibrous materials for peptide synthesis and biomedical applications. Originally chemical inert isotactic polypropylene (iPP) fabric was utilized and modified to serve as a functional flexible planar solid support for solid phase peptide synthesis. The modification was achieved through thermal initiated radical grafting polymerization using acrylic acid, poly (ethylene glycol) diacrylate as monomers, and benzoyl peroxide as radical initiator. The iPP fabric was successfully functionalized and possessing as high as 0.7mmol/g carboxylic acid groups. Peptide ligand LHPQF was successfully synthesized on the new functional planar support. Specific enzyme immobilization was fulfilled on the functional iPP fabric support. A commercially available ethylene-acrylic acid copolymer was made into ultrafine copolymer fiber bundles which are composed of nanofibers with diameters ranging from 200nm to 800nm. Various mixing ratios of copolymer/matrix materials were utilized to explore the effect on the final nanofiber physical properties including morphology and stability in solvents. The surface carboxylic acid groups were further converted to amino groups before the functional nanofibers can be applied in solid phase peptide synthesis. Two peptide ligands, LHPQF and HWRGWV, were also successfully synthesized on the nanofiber bundles. Streptavidin and human immunoglobulin G specific binding with the corresponding ligand which was anchored on the nanofibers was conducted successfully to illustrate the potential applications of the nanofiber materials in biomedical field. Further study on the dispersion of the ethylene-acrylic acid nanofiber bundles was pursued to take advantage of the super high active surface area of functional nanofibers. To manipulate the polymer nanofibers during synthesis and bio-assays, a technique was developed to controllably assemble and disperse the

  9. Mechanism and microstructures in Ga2O3 pseudomartensitic solid phase transition.

    Science.gov (United States)

    Zhu, Sheng-Cai; Guan, Shu-Hui; Liu, Zhi-Pan

    2016-07-21

    Solid-to-solid phase transition, although widely exploited in making new materials, challenges persistently our current theory for predicting its complex kinetics and rich microstructures in transition. The Ga2O3α-β phase transformation represents such a common but complex reaction with marked change in cation coordination and crystal density, which was known to yield either amorphous or crystalline products under different synthetic conditions. Here we, via recently developed stochastic surface walking (SSW) method, resolve for the first time the atomistic mechanism of Ga2O3α-β phase transformation, the pathway of which turns out to be the first reaction pathway ever determined for a new type of diffusionless solid phase transition, namely, pseudomartensitic phase transition. We demonstrate that the sensitivity of product crystallinity is caused by its multi-step, multi-type reaction pathway, which bypasses seven intermediate phases and involves all types of elementary solid phase transition steps, i.e. the shearing of O layers (martensitic type), the local diffusion of Ga atoms (reconstructive type) and the significant lattice dilation (dilation type). While the migration of Ga atoms across the close-packed O layers is the rate-determining step and yields "amorphous-like" high energy intermediates, the shearing of O layers contributes to the formation of coherent biphase junctions and the presence of a crystallographic orientation relation, (001)α//(201[combining macron])β + [120]α//[13[combining macron]2]β. Our experiment using high-resolution transmission electron microscopy further confirms the theoretical predictions on the atomic structure of biphase junction and the formation of (201[combining macron])β twin, and also discovers the late occurrence of lattice expansion in the nascent β phase that grows out from the parent α phase. By distinguishing pseudomartensitic transition from other types of mechanisms, we propose general rules to predict the

  10. Phase wettability and microstructural evolution in solid oxide fuel cell anode materials

    International Nuclear Information System (INIS)

    Recent experimental and theoretical findings suggest that high-temperature solid oxide fuel cells (SOFCs) often suffer from performance degradation due to coarsening of the metallic-phase particles within the anode. In this study, we explore the feasibility of improving the microstructural stability of SOFC anode materials by tuning the contact angle between the metallic phase and electrolyte particles. To this end, a continuum diffuse-interface model is employed to capture the coarsening behavior of the metallic phase and simulate a range of equilibrium contact angles. The evolution of performance-critical, microstructural features is presented for varying degrees of phase wettability. It is found that both the density of electrochemically active triple- phase regions and contiguity of the electron-conducting phase display undesirable minima near the contact angle of conventional SOFC materials. Our results suggest that tailoring the interfacial properties of the constituent phases could lead to a significant increase in the performance and lifetime of SOFCs

  11. Optical manipulation of Berry phase in a solid-state spin qubit

    CERN Document Server

    Yale, Christopher G; Zhou, Brian B; Auer, Adrian; Burkard, Guido; Awschalom, David D

    2015-01-01

    The phase relation between quantum states represents an essential resource for the storage and processing of quantum information. While quantum phases are commonly controlled dynamically by tuning energetic interactions, utilizing geometric phases that accumulate during cyclic evolution may offer superior robustness to noise. To date, demonstrations of geometric phase control in solid-state systems rely on microwave fields that have limited spatial resolution. Here, we demonstrate an all-optical method based on stimulated Raman adiabatic passage to accumulate a geometric phase, the Berry phase, in an individual nitrogen-vacancy (NV) center in diamond. Using diffraction-limited laser light, we guide the NV center's spin along loops on the Bloch sphere to enclose arbitrary Berry phase and characterize these trajectories through time-resolved state tomography. We investigate the limits of this control due to loss of adiabiaticity and decoherence, as well as its robustness to noise intentionally introduced into t...

  12. HPLC WITH SOLID PHASE EXTRACTION FOR IDENTIFICATION AND DIAGNOSIS OF ORGANOPHOSPHOROUS POISONING IN GOATS

    Directory of Open Access Journals (Sweden)

    S. Manna

    2014-12-01

    Full Text Available High performance liquid chromatographic determination of organophosphorous compound has been done by reverse phase chromatography in goats. The goats were dying showing the symptoms of organophosphorous poisoning. The viscera and stomach contents sample were received from Project Co-Ordinator, Animal Disease Research Institute, Phulnakhara, Cuttack, Orissa. The analysis of samples by HPLC with UV detector after cleaning up in Solid Phase Extraction (SPE revealed presence of malathion that was later quantified.

  13. Dipolar recoupling in solid state NMR by phase alternating pulse sequences

    OpenAIRE

    J. Lin; Bayro, M.; Griffin, R G; Khaneja, N.

    2008-01-01

    We describe some new developments in the methodology of making heteronuclear and homonuclear recoupling experiments in solid state NMR insensitive to rf-inhomogeneity by phase alternating the irradiation on the spin system every rotor period. By incorporating delays of half rotor periods in the pulse sequences, these phase alternating experiments can be made γ encoded. The proposed methodology is conceptually different from the standard methods of making recoupling experiments robust by the u...

  14. Application of SMES coordinated with solid-state phase shifter toload frequency control

    OpenAIRE

    Ngamroo, I.; Mitani, Yasunori; K. Tsuji

    1999-01-01

    This paper proposes a sophisticated application of SMES to load frequency control (LFC) in an interconnected power system. The SMES is coordinated with a solid-state phase shifter to enhance the LFC. The frequency control concept and control design of a SMES coordinated with a phase shifter are presented. Numerical results demonstrate the significant effects of LFC by the proposed control and the economical advantage of MJ capacity of SMES

  15. Treatment technologies of liquid and solid wastes from two-phase olive oil mills

    OpenAIRE

    Rincón, Bárbara; Raposo, Francisco; Borja, Rafael

    2006-01-01

    Over the last 10 years the manufacture of olive oil has undergone important evolutionary changes in the equipment used for the separation of olive oil from the remaining components. The latest development has been the introduction of a two-phase centrifugation process in which a horizontally-mounted centrifuge is used for a primary separation of the olive oil fraction from the vegetable solid material and vegetation water. Therefore, the new two-phase olive oil mills produce three identifiabl...

  16. Treatment technologies of liquid and solid wastes from two-phase olive oil mills

    OpenAIRE

    Borja Padilla, Rafael; Raposo Bejines, Francisco; Rincón, Bárbara

    2006-01-01

    Over the last 10 years the manufacture of olive oil has undergone important evolutionary changes in the equipment used for the separation of olive oil from the remaining components. The latest development has been the introduction of a two-phase centrifugation process in which a horizontally-mounted centrifuge is used for a primary separation of the olive oil fraction from the vegetable solid material and vegetation water. Therefore, the new two-phase olive oil mills produce three ident...

  17. Application of the method of solid-phase spectrometry for test-determination of antioxidants

    OpenAIRE

    Бельтюкова, C. D.; Лівенцова, О. О.; СТЕПАНОВА А.А.

    2015-01-01

    The work reveals advantages of a method of solid-phase spectrometry, with registration of a luminescent signal of anolyte in a sorbent phase in paticular, compared with usual spectroscopic methods. The possibility of use of a sensitized luminescence of lanthanides (ions of Terbium(III) ) as a luminescent marker when determining antioxidants of polyphenolic type is established. Advantages of this method, allowing to carry out quality control, safety or falsifications of foodstuff are noted. Th...

  18. Phase I study of afatinib combined with nintedanib in patients with advanced solid tumours

    OpenAIRE

    Bahleda, Rastislav; Hollebecque, Antoine; Varga, Andrea; Gazzah, Anas; Massard, Christophe; Deutsch, Eric; Amellal, Nadia; Farace, Françoise; Ould-Kaci, Mahmoud; Roux, Flavien; Marzin, Kristell; Soria, Jean-Charles

    2015-01-01

    Background: This Phase I study evaluated continuous- and intermittent-dosing (every other week) of afatinib plus nintedanib in patients with advanced solid tumours. Methods: In the dose-escalation phase (n=45), maximum tolerated doses (MTDs) were determined for continuous/intermittent afatinib 10, 20, 30 or 40 mg once daily plus continuous nintedanib 150 or 200 mg twice daily. Secondary objectives included safety and efficacy. Clinical activity of continuous afatinib plus nintedanib at the MT...

  19. Volatile profile of yellow passion fruit juice by static headspace and solid phase microextraction techniques

    OpenAIRE

    Gilberto Costa Braga; Adna Prado; Jair Sebastião da Silva Pinto; Severino Matias de Alencar

    2015-01-01

    The profile of volatile compounds of yellow passion fruit juice was analyzed by solid phase microextraction headspace (HS-SPME) and optimized static headspace (S-HS) extraction techniques. Time, temperature, NaCl concentration and sample volume headspace equilibrium parameters was adjusted to the S-HS technique. The gaseous phase in the headspace of samples was collected and injected into a gas chromatograph coupled to a mass spectrometer. In the HS-SPME technique was identified 44 volatile c...

  20. Influence of copolymer composition on the phase behavior of solid dispersions.

    Science.gov (United States)

    Prudic, Anke; Kleetz, Tobias; Korf, Marcel; Ji, Yuanhui; Sadowski, Gabriele

    2014-11-01

    The incorporation of poorly soluble active pharmaceutical ingredients (APIs) into excipients (e.g., polymers) to formulate an amorphous solid dispersion is a promising strategy to improve the oral bioavailability of the API. The application of copolymer excipients allows access to combinations of different monomers and thus to the design of excipients to improve solid-dispersion properties. In this work, the thermodynamic phase behavior of solid dispersions was investigated as a function of the API, type of monomer, and copolymer composition. The glass-transition temperatures and API solubilities in the solid dispersions of naproxen and indomethacin in polyvinylpyrrolidone, polyvinyl acetate, and copolymers with different weight fractions of vinylpyrrolidone and vinyl actetate were investigated. It is shown that the thermodynamic phase behavior of API/copolymer solid dispersions is a function of monomer type and copolymer composition. This effect was also predicted by using the perturbed-chain statistical associating fluid theory (PC-SAFT). The glass-transition temperature of the solid dispersions was calculated with the Gordon-Taylor equation. PMID:25295846

  1. Optically driven atomic coherences: from the gas phase to the solid state

    International Nuclear Information System (INIS)

    Full text: Coherent interactions between strong radiation and quantum systems provide well-established tools to control optical properties and processes. Among others, applications aim at efficient data storage and processing of optically stored data, e.g. as required in quantum information processing. Thus, a large number of experimental studies in quantum information science have been conducted in atomic media in the gas phase. Only few experiments on coherent, adiabatic interactions were conducted in solid state media. Appropriate solid materials for such investigations are quantum dots, color centers, or rare-earth doped solids. The latter combine the advantages of atoms in the gas phase, i.e. spectrally narrow transitions and long dephasing times, with the advantages of solids, i.e. large density and scalability. In the talk we present implementations of coherent interactions in a rare-earth doped solid, i.e. a Pr:YSO crystal. In particular we report on the experimental implementation of stimulated Raman adiabatic passage (STIRAP) in Pr:YSO. Our data provide clear and striking proof for complete population inversion between hyperfine levels in the praseodymium dopants. Time-resolved absorption measurements serve to monitor the adiabatic population dynamics during the STIRAP process. We will discuss the possibilities of STIRAP and related techniques to drive atomic coherences in the solid state environment, e.g. for applications in optical and quantum information processing. (author)

  2. Dynamically slow solid-to-solid phase transition induced by thermal treatment of DimimFeCl4 magnetic ionic liquid.

    Science.gov (United States)

    de Pedro, Imanol; Fabelo, Oscar; García-Saiz, Abel; Vallcorba, Oriol; Junquera, Javier; Blanco, Jesús Angel; Waerenborgh, João Carlos; Andreica, D; Wildes, Andrew; Fernández-Díaz, María Teresa; Fernández, Jesús Rodríguez

    2016-08-01

    The results reported here represent the first direct experimental observations supporting the existence of a solid-to-solid phase transition induced by thermal treatment in magnetic ionic liquids (MILs). The phase transitions of the solid phases of 1,3-dimethylimidazolium tetrachloroferrate, DimimFeCl4, are closely related to its thermal history. Two series of solid-to-solid phase transitions can be described in this MIL: (i) from room temperature (RT) phase II [space group (s.g.) = P21] to phase I-a [s.g. = P212121] via thermal quenching or via fast cooling at T > 2 K min(-1); (ii) from phase I-a to phase I-b [s.g. = P21/c] when the temperature was kept above 180 K for several minutes. The latter involves a slow translational and reorientational dynamical process of both the imidazolium cation and the tetrachloroferrate anion and has been characterized using synchrotron and neutron powder diffraction and DFT (density functional theory) studies. The transition is also related to the modification of the super-exchange pathways of low-temperature phases which show a overall antiferromagnetic behavior. A combination of several experimental methods such as magnetometry, Mössbauer and muon spectroscopy together with polarized and non-polarized neutron powder diffraction has been used in order to characterize the different features observed in these phases. PMID:27439896

  3. Ni coarsening in the three-phase solid oxide fuel cell anode - a phase-field simulation study

    CERN Document Server

    Chen, Hsun-Yi; Cronin, J Scott; Wilson, James R; Barnett, Scott A; Thornton, Katsuyo

    2012-01-01

    Ni coarsening in Ni-yttria stabilized zirconia (YSZ) solid oxide fuel cell anodes is considered a major reason for anode degradation. We present a predictive, quantative modeling framework based on the phase-field approach to systematically examine coarsening kinetics in such anodes. The initial structures for simulations are experimentally acquired functional layers of anodes. Sample size effects and error analysis of contact angles are examined. Three phase boundary (TPB) lengths and Ni surface areas are quantatively identified on the basis of the active, dead-end, and isolated phase clusters throughout coarsening. Tortuosity evolution of the pores is also investigated. We find that phase clusters with larger characteristic length evolve slower than those with smaller length scales. As a result, coarsening has small positive effects on transport, and impacts less on the active Ni surface area than the total counter part. TPBs, however, are found to be sensitive to local morphological features and are only i...

  4. Phosphopeptide Characterization by Mass Spectrometry using Reversed-Phase Supports for Solid-Phase β-Elimination/Michael Addition

    OpenAIRE

    Nika, Heinz; Lee, Jaehoon; Willis, Ian M.; Angeletti, Ruth Hogue; Hawke, David H.

    2012-01-01

    We have adapted the Ba2+ ion-catalyzed concurrent Michael addition reaction to solid-phase derivatization on ZipTipC18 pipette tips using 2-aminoethanethiol as a nucleophile. This approach provides several advantages over the classical in-solution-based techniques, including ease of operation, completeness of reaction, improved throughput, efficient use of dilute samples, and amenability to automation. Phosphoseryl and phosphothreonyl peptides, as well as phosphoserine peptides with adjoining...

  5. Two-phase flow meter for determining water and solids volumetric flow rate in vertical and inclined solids-in-water flows

    OpenAIRE

    Muhamedsalih, Yousif

    2014-01-01

    Multiphase flow can be defined as the simultaneous flow of a stream of two or more phases. Solids-in-water flow is a multiphase flows where solids and liquid are both present. Due to the density differences of the two phases, the results for such flow is often to have non-uniform profiles of the local volume fraction and local axial velocity for both phases in the flow cross-section. These non-uniform profiles are clearly noticeable in solids-in-water stratified flow with moving bed for incli...

  6. A Solid Phase Synthesis of Chalcones by Claisen-Schmidt Condensations

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to accelerate the development of relatively inexpensive antimalarials that are effective against chloroquine-resistant strains of Plasmodium falclparum, a methodology for the solid phase synthesis of chalcone (l, 3-diphenyl-2-propen-l-one) analogues in reasonably high yields has been developed.

  7. Solid-phase oligosaccharide synthesis with tris(alkoxy)benzyl amine (BAL) safety-catch anchoring

    DEFF Research Database (Denmark)

    Tolborg, Jakob Fjord; Jensen, Knud Jørgen

    2000-01-01

    A tris(alkoxy)benzylamine (BAL) handle strategy was developed for safety-catch anchoring of D-glucosamine derivatives in solid-phase synthesis of oligosaccharides; the linkage between the BAL handle and the amine proved stable to conc. TFA and Lewis acids, but after N-acylation the amide could be...

  8. Effects of Inoculum Size on Solid-Phase Fermentation of Fodder Beets for Fuel Ethanol Production

    OpenAIRE

    Gibbons, William R.; Westby, Carl A.

    1986-01-01

    This fuel ethanol study examined the effects of Saccharomyces cerevisiae inoculum size on solid-phase fermentation of fodder beet pulp. A 5% inoculum (wt/wt) resulted in rapid yeast and ethanol (9.1% [vol/vol]) production. Higher inocula showed no advantages. Lower inocula resulted in lowered final yeast populations and increased fermentation times.

  9. Comparison of solid and liquid-phase bioassays using ecoscores to assess contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Lors, Christine [Universite Lille Nord de France, 1bis rue Georges Lefevre, 59044 Lille Cedex (France); Ecole des Mines de Douai, LGCgE-MPE-GCE, 941 rue Charles-Bourseul, 59500 Douai (France); Centre National de Recherche sur les Sites et Sols Pollues, 930 Boulevard Lahure, BP 537, 59505 Douai Cedex (France); Ponge, Jean-Francois, E-mail: ponge@mnhn.fr [Museum National d' Histoire Naturelle, Departement Ecologie et Gestion de la Biodiversite, CNRS UMR 7179, 4 Avenue du Petit-Chateau, 91800 Brunoy (France); Martinez Aldaya, Maite [Museum National d' Histoire Naturelle, Departement Ecologie et Gestion de la Biodiversite, CNRS UMR 7179, 4 Avenue du Petit-Chateau, 91800 Brunoy (France); Damidot, Denis [Universite Lille Nord de France, 1bis rue Georges Lefevre, 59044 Lille Cedex (France); Ecole des Mines de Douai, LGCgE-MPE-GCE, 941 rue Charles-Bourseul, 59500 Douai (France)

    2011-10-15

    Bioassays on aqueous and solid phases of contaminated soils were compared, belonging to a wide array of trophic and response levels and using ecoscores for evaluating ecotoxicological and genotoxicological endpoints. The method was applied to four coke factory soils contaminated mainly with PAHs, but also to a lesser extent by heavy metals and cyanides. Aquatic bioassays do not differ from terrestrial bioassays when scaling soils according to toxicity but they are complementary from the viewpoint of ecological relevance. Both aquatic and terrestrial endpoints are strongly correlated with concentrations of 3-ring PAHs. This evaluation procedure allows us to propose a cost-effective battery which embraces a wide array of test organisms and response levels: it includes two rapid bioassays (Microtox) and springtail avoidance), a micronucleus test and three bioassays of a longer duration (algal growth, lettuce germination and springtail reproduction). This battery can be recommended for a cost-effective assessment of polluted/remediated soils. - Highlights: > Comparison of liquid- and solid-phase bioassays on contaminated soils, using ecoscores. > Complementarity of liquid- and solid-phase bioassays for the evaluation of environmental hazards. > Proposal for a restricted battery of 5 most sensitive tests. > Use of this restricted battery for a cost-effective assessment of polluted/remediated soils. - Aqueous and solid phases of contaminated soils give similar results in terms of toxicity but are complementary for the evaluation of environmental hazards by ecoscores.

  10. Matrix solid-phase dispersion for the liquid chromatographic determination of phenolic acids in Melissa officinalis.

    Science.gov (United States)

    Ziaková, Alica; Brandsteterová, Eva; Blahová, Eva

    2003-01-01

    Matrix solid-phase dispersion (MSPD) was used for sample preparation of plant material (Melissa officinalis, Lemon Balm) prior to liquid chromatography of rosmarinic, caffeic and protocatechuic acids, phenolic compounds present in this herb. Different MSPD sorbents and various elution agents were tested and the optimal extraction conditions determined with the aim to obtain extraction recoveries greater than 90% for all analytes. PMID:12568390

  11. An amine-derivatized, DOTA-loaded polymeric support for Fmoc Solid Phase Peptide Synthesis

    OpenAIRE

    Yoo, Byunghee; Sheth, Vipul R.; Pagel, Mark D.

    2009-01-01

    An amine-derivatized DOTA has been used to modify the surface of a polymeric support for conventional Solid Phase Peptide Synthesis (SPPS) following standard Fmoc chemistry methods. This methodology was used to synthesize a peptide-DOTA conjugate that was demonstrated to be a PARACEST MRI contrast agent. Therefore, this synthesis methodology can facilitate Fmoc SPPS of molecular imaging contrast agents.

  12. A convenient procedure for the solid-phase synthesis of hydroxamic acids on PEGA resins

    DEFF Research Database (Denmark)

    Nandurkar, Nitin Subhash; Petersen, Rico; Qvortrup, Katrine;

    2011-01-01

    An efficient method for the solid-phase synthesis of hydroxamic acids is described. The method comprises the nucleophilic displacement of esters immobilized on PEGA resins with hydroxylamine/sodium hydroxide in isopropanol. The hydroxyaminolysis protocol is compatible with a broad range of PEGA...

  13. Solid-phase microextraction of hydrocarbons from water in a centrifuge

    Science.gov (United States)

    Ryabov, A. Yu.; Chuikin, A. V.; Velikov, A. A.

    2016-06-01

    The results of our study of solid-phase microextraction of substances using a centrifuge for determining the microquantities of hydrocarbon impurities in water are presented. The cartridge diameter, sorbent mass, and solvent volume were shown to affect the percent extraction of substances and the analytical signal intensity. The relationship between the cartridge geometry, the sorbent mass, and the solvent volume was considered.

  14. Kinetic study of solid phase crystallisation of expanding thermal plasma deposited a-Si:H

    NARCIS (Netherlands)

    Law, F.; Hoex, B.; Wang, J.; Luther, J.; Sharma, K.; Creatore, M.; M. C. M. van de Sanden,

    2012-01-01

    In-situ X-ray diffraction was used to study the dynamics of the solid phase crystallisation (SPC) of hydrogenated amorphous silicon (a-Si:H) films deposited by expanding thermal plasma technique. The Johnson-Mehl-Avrami-Kolmogorov model was used for the analysis of the dynamic data and the activatio

  15. Determination of Plant Volatiles Using Solid Phase Microextraction GC-MS

    Science.gov (United States)

    Van Bramer, Scott; Goodrich, Katherine R.

    2015-01-01

    This experiment combines analytical techniques of solid phase microextraction and gas chromatography-mass spectrometry with easily relatable and accessible plant volatile chemistry (floral and vegetative scents of local/available plants). The biosynthesis and structure of these chemicals are of interest in the areas of organic chemistry,…

  16. Final Report for Nucleation and growth of semiconductor nanocrystals by solid-phase reaction

    Energy Technology Data Exchange (ETDEWEB)

    P. D. Persans; T. M. Hayes

    2005-12-12

    This final report describes the technical output of a scientific program aimed at understanding the formation and structure of II-VI nanocrystals formed by solid phase precipitation within a glass environment. The principle probes were optical absorption spectroscopy to determine crystallite sizes, Raman scattering to determine composition, and x-ray absorption spectroscopy to study the evolution of local reactant environments.

  17. Indirect solid-phase immunosorbent assay for detection of arenavirus antigens and antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A.P.; Rezapkin, G.V.; Dzagurova, T.K.; Tkachenko, E.A. (Institute of Poliomyelitis anU Viral Encephalities of the U.S.S.R. Academy of Medical Sciences, Moscow)

    1984-05-01

    Indirect enzyme-linked immunosorbent assay (ELISA) and solid phase radioimmunoassay (SPRIA) using either enti-human or anti-mouse IgG labelled with horseradish peroxidase and /sup 125/I, respectively, were developed for the detection of Junin, Machupo, Tacaribe, Amapari, Tamiami, Lassa and LCM arenaviruses. Both methods allow high sensitivity detection of arenavirus antigens and antibodies.

  18. Expedient protocol for solid-phase synthesis of secondary and tertiary amines

    DEFF Research Database (Denmark)

    Olsen, Christian A; Witt, Matthias; Jaroszewski, Jerzy W; Franzyk, Henrik

    2004-01-01

    [reaction: see text] An expedient solid-phase synthetic approach to secondary and tertiary amines was developed. The protocol employs conversion of resin-bound amino alcohols to the corresponding iodides, followed by iodide displacement with primary or secondary amines or with unprotected amino...

  19. AUTOMATED SOLID PHASE EXTRACTION GC/MS FOR ANALYSIS OF SEMIVOLATILES IN WATER AND SEDIMENTS

    Science.gov (United States)

    Data is presented on the development of a new automated system combining solid phase extraction (SPE) with GC/MS spectrometry for the single-run analysis of water samples containing a broad range of organic compounds. The system uses commercially available automated in-line sampl...

  20. Technical note: New applications for on-line automated solid phase extraction

    OpenAIRE

    MacFarlane, John D.

    1997-01-01

    This technical note explains the disadvantages of manual solid phase extraction (SPE) techniques and the benefits to be gained with automatic systems. The note reports on a number of general and highly specific applications using the Sample Preparation Unit OSP-2A.

  1. Automatic reactor for solid-phase synthesis of molecularly imprinted polymeric nanoparticles (MIP NPs) in water

    OpenAIRE

    Poma, Alessandro; Guerreiro, Antonio; Caygill, Sarah; Moczko, Ewa; Piletsky, Sergey

    2014-01-01

    We report the development of an automated chemical reactor for solid-phase synthesis of MIP NPs in water. Operational parameters are under computer control, requiring minimal operator intervention. In this study, “ready for use” MIP NPs with sub-nanomolar affinity are prepared against pepsin A, trypsin and α-amylase in only 4 hours.

  2. A simplified radiometabolite analysis procedure for PET radioligands using a solid phase extraction with micellar medium

    International Nuclear Information System (INIS)

    A solid phase extraction method has been developed for simple and high-speed direct determination of PET radioligands in plasma. Methods: This methodology makes use of a micellar medium and a solid-phase extraction cartridge for displacement of plasma protein bound radioligand and separation of PET radioligands from their radiometabolites without significant preparation. The plasma samples taken from monkey or human during PET measurements were mixed with a micellar eluent containing an anionic surfactant sodium dodecyl sulphate and loaded onto SPE cartridges. The amount of radioactivity corresponding to parent radioligand (retained on the cartridge) and its radioactive metabolites (eluted with micellar eluent) was measured. Results: Under the optimized conditions, excellent separation of target PET radioligands from their radiometabolites was achieved with a single elution and short run-time of 1 min. This method was successfully applied to study the metabolism for 11C-labelled radioligands in human or monkey plasma. The amount of parent PET radioligands estimated by micellar solid phase extraction strongly corresponded with that determined by radio-LC. The improved throughput permitted the analysis of a large number of plasma samples (up to 13 samples per one PET study) for accurate estimation of metabolite-corrected input function during quantitative PET imaging studies. Conclusion: Solid phase extraction together with micellar medium is fast, sensitive and easy to use, and therefore it is an attractive alternative method to determine relative composition of PET radioligands in plasma

  3. 40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.

    Science.gov (United States)

    2010-07-01

    ... the case may be, may require that the separation of liquid, suspended particulate, and solid phases of the material be performed upon a mixture of the waste with ocean water rather than on the material... alkaline waste) based on guidance provided by EPA on particular cases, or in accordance with approved...

  4. Use of Solid Phase Extraction in the Biochemistry Laboratory to Separate Different Lipids

    Science.gov (United States)

    Flurkey, William H.

    2005-01-01

    Solid-phase extraction (SPE) was used to demonstrate how various lipids and lipid classes could be separated in a biochemistry laboratory setting. Three different SPE methods were chosen on their ability to separate a lipid mixture, consisting of a combination of a either a fatty acid, a triacylglycerol, a mono- or diacylglycerol, phospholipid,…

  5. Solid-phase extraction of berries’ anthocyanins and evaluation of their antioxidative properties

    Czech Academy of Sciences Publication Activity Database

    Denev, P.; Číž, Milan; Ambrožová, Gabriela; Lojek, Antonín; Yanakieva, I.; Kratchanova, M.

    2010-01-01

    Roč. 123, č. 4 (2010), s. 1055-1061. ISSN 0308-8146 R&D Projects: GA MŠk(CZ) OC08058 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : anthocyanins * solid-phase extraction * berry extracts Subject RIV: BO - Biophysics Impact factor: 3.458, year: 2010

  6. Investigating the Retention Mechanisms of Liquid Chromatography Using Solid-Phase Extraction Cartridges

    Science.gov (United States)

    O'Donnell, Mary E.; Musial, Beata A.; Bretz, Stacey Lowery; Danielson, Neil D.; Ca, Diep

    2009-01-01

    Liquid chromatography (LC) experiments for the undergraduate analytical laboratory course often illustrate the application of reversed-phase LC to solve a separation problem, but rarely compare LC retention mechanisms. In addition, a high-performance liquid chromatography instrument may be beyond what some small colleges can purchase. Solid-phase…

  7. Linkers, resins, and general procedures for solid-phase peptide synthesis

    DEFF Research Database (Denmark)

    Shelton, Anne Pernille Tofteng; Jensen, Knud Jørgen

    This chapter describes the basic protocols for solid-phase peptide synthesis using the Fmoc group as the N-alpha-protecting group (Fmoc-SPPS). The chapter introduces resins and their handling, choice of linkers, and the most common methods for peptide chain assembly. The proper choice of resins a...

  8. Solid-phase synthesis of polyfunctional polylysine dendrons using aldehyde linkers

    DEFF Research Database (Denmark)

    Svenssen, Daniel K.; Mirsharghi, Sahar; Boas, Ulrik

    2014-01-01

    A straightforward method for the solid-phase synthesis of C-terminally modified polylysine dendrons has been developed by applying bisalkoxybenzaldehyde and trisalkoxybenzaldehyde linkers. The method has been used for the synthesis of polylysine dendrons with a variety of C-terminal ‘tail groups’...

  9. Microwave-assisted solid-phase Ugi four-component condensations

    DEFF Research Database (Denmark)

    Nielsen, John

    1999-01-01

    An 18-member library was constructed from 2 isocyanides, 3 aldehydes and 3 carboxylic acids via microwave-assisted solid-phase Ugi reactions on TentaGel S RAM. Products of high purity were obtained in moderate to excellent yields after reaction times of 5 minutes or less (irradiation at 60W). (C)...

  10. Soxhlet-assisted matrix solid phase dispersion to extract flavonoids from rape (Brassica campestris) bee pollen.

    Science.gov (United States)

    Ma, Shuangqin; Tu, Xijuan; Dong, Jiangtao; Long, Peng; Yang, Wenchao; Miao, Xiaoqing; Chen, Wenbin; Wu, Zhenhong

    2015-11-15

    Soxhlet-assisted matrix solid phase dispersion (SA-MSPD) method was developed to extract flavonoids from rape (Brassica campestris) bee pollen. Extraction parameters including the extraction solvent, the extraction time, and the solid support conditions were investigated and optimized. The best extraction yields were obtained using ethanol as the extraction solvent, silica gel as the solid support with 1:2 samples to solid support ratio, and the extraction time of one hour. Comparing with the conventional solvent extraction and Soxhlet method, our results show that SA-MSPD method is a more effective technique with clean-up ability. In the test of six different samples of rape bee pollen, the extracted content of flavonoids was close to 10mg/g. The present work provided a simple and effective method for extracting flavonoids from rape bee pollen, and it could be applied in the studies of other kinds of bee pollen. PMID:26454344

  11. Hydrodynamic and thermal fields analysis in gas-solid two-phase flow

    International Nuclear Information System (INIS)

    The present work aims to investigate numerically the flowfield and heat transfer process in gas-solid suspension in a vertical pneumatic conveying pipe. The Eulerian-Lagrangian model is used to simulate the flow of the two-phases. The gas phase is simulated based on Reynolds Average Navier-Stokes equations (RANS) with low Reynolds number k-ε model, while particle tracking procedure is used for the solid phase. An anisotropic model is used to calculate the Reynolds stresses and the turbulent Prandtl number is calculated as a function of the turbulent viscosity. The model takes into account the lift and drag forces and the effect of particle rotation as well as the particles dispersion by turbulence effect. The effects of inter-particles collisions and turbulence modulation by the solid particles, i.e. four-way coupling, are also included in the model. Comparisons between different models for turbulence modulation with experimental data are carried out to select the best model. The model is validated against published experimental data for velocities of the two phases, turbulence intensity, solids concentration, pressure drop, heat transfer rates and Nusselt number distribution. The comparisons indicate that the present model is able to predict the complex interaction between the two phases in non-isothermal gas-solid flow in the tested range. The results indicate that the particle-particle collision, turbulence dispersion and lift force play a key role in the concentration distribution. In addition, the heat transfer rate increases as the mass loading ratio increases and Nusselt number increases as the pipe diameter increases.

  12. Development of a solid-phase assay for measurement of proteolytic enzyme activity

    International Nuclear Information System (INIS)

    A solid-phase, plate assay was developed for the measurement of proteolytic enzyme activity. In this assay procedure, radiolabeled substrates were dried onto the surface of microtiter wells. Following drying, the wells were washed two times with saline to remove the nonadherent substrate. When proteolytic enzymes were added to the wells, protein hydrolysis occurred, releasing radioactivity into the supernatant fluid. The amount of protein hydrolysis that occurred was reflected by the amount of radioactivity in the supernatant fluid. When 125I-hemoglobin was used as the substrate, it was as susceptible to hydrolysis by trypsin in the solid-phase assay as it was in solution in a standard assay procedure. Protease activity from a variety of sources (including from viable cells as well as from extracellular sources) were also able to hydrolyze the hemoglobin on the plate. 125I-Labeled serum albumen, fibrinogen, and rat pulmonary basement membrane were also susceptible to hydrolysis by trypsin in the solid phase. When [14C]elastin was dried onto the plate, it behaved in a similar manner to elastin in solution. It was resistant to hydrolysis by nonspecific proteases such as trypsin and chymotrypsin but was highly susceptible to hydrolysis by elastase. The solid-phase plate assay has several features which recommended it for routine use. It is as sensitive as standard tube assays (and much more sensitive than routinely used colormetric assays). It is quick and convenient; there are no precipitation, centrifugation, or filtration steps. In addition, very small volumes of radioactive wastes are generated. Another advantage of the solid-phase plate assay is the resistance of the dried substrates to spontaneous breakdown and to microbial contamination. Finally, this assay is suitable for use with viable cells as well as for extracellular proteases

  13. Solid-state dual-frequency laser free from anti-phase noise

    OpenAIRE

    El Amili, Abdelkrim; Loas, Goulc'Hen; De, Syamsundar; Schwartz, Sylvain; Feugnet, Gilles; Pocholle, Jean-Paul; Bretenaker, Fabien; Alouini, Mehdi

    2013-01-01

    Dual-frequency solid-state lasers are attractive for a large number of applications such as microwave photonics, spectroscopy, and metrology. As far as dual-frequency lasers are considered, the intensity noise spectrum of each eigenmode exhibits two peaks lying at the well-known in-phase and anti-phase eigen-frequencies of two coupled oscillators. The in-phase noise, which corresponds to the standard relaxation oscillations of the laser, can be reduced either electronically or optically using...

  14. Free energy model for solid high-pressure phases of carbon.

    Science.gov (United States)

    Schöttler, Manuel; French, Martin; Cebulla, Daniel; Redmer, Ronald

    2016-04-13

    Analytic free energy models for three solid high-pressure phases--diamond, body centered cubic phase with eight atoms in the unit cell (BC8), and simple cubic (SC)--are developed using density functional theory. We explicitly include anharmonic effects by performing molecular dynamics simulations and investigate their density and temperature dependence in detail. Anharmonicity in the nuclear motion shifts the phase transitions significantly compared to the harmonic approximation. Furthermore, we apply a thermodynamically constrained correction that brings the equation of state in accordance with diamond anvil cell experiments. The performance of our thermodynamic functions is validated against Hugoniot experiments. PMID:26974530

  15. New methodological improvements in the Microtox® solid phase assay.

    Science.gov (United States)

    Burga Pérez, Karen F; Charlatchka, Rayna; Sahli, Leila; Férard, Jean-François

    2012-01-01

    The classic Microtox® solid phase assay (MSPA) based on the inhibition of light production of the marine bacteria recently renamed Aliivibrio fischeri suffers from various bias and interferences, mainly due to physico-chemical characteristics of the tested solid phase. To precisely assess ecotoxicity of sediments, we have developed an alternative method, named Microtox® leachate phase assay (MLPA), in order to measure the action of dissolved pollutants in the aqueous phase. Two hypotheses were formulated to explain the observed difference between MSPA and MLPA results: a real ecotoxicity of the solid phase or the fixation of bacteria to fine particles and/or organic matter. To estimate the latter, flow cytometry analyses were performed with two fluorochromes (known for their ability to stain bacterial DNA), allowing correction of MSPA measurements and generation of new (corrected) IC50. Comparison of results of MLPA with the new IC50 MSPA allows differentiating real ecotoxic and fixation effect in classic MSPA especially for samples with high amount of fines and/or organic matter. PMID:21962521

  16. Optical manipulation of the Berry phase in a solid-state spin qubit

    Science.gov (United States)

    Yale, Christopher G.; Heremans, F. Joseph; Zhou, Brian B.; Auer, Adrian; Burkard, Guido; Awschalom, David D.

    2016-03-01

    Phase relations between quantum states represent a resource for storing and processing quantum information. Although quantum phases are commonly controlled dynamically by tuning energetic interactions, the use of geometric phases that accumulate during cyclic evolution may offer superior robustness to noise. To date, demonstrations of geometric phase in solid-state systems employ microwave fields that have limited spatial resolution. Here, we demonstrate an all-optical method to accumulate a geometric phase, the Berry phase, in an individual nitrogen-vacancy centre in diamond. Using stimulated Raman adiabatic passage controlled by diffraction-limited laser light, we loop the nitrogen-vacancy centre's spin around the Bloch sphere to enclose an arbitrary Berry phase. We investigate the limits of this control due to the loss of adiabaticity and decoherence, as well as its robustness to noise introduced into the experimental control parameters. These techniques set the foundation for optical geometric manipulation in photonic networks of solid-state qubits linked and controlled by light.

  17. A Variational Model for Two-Phase Immiscible Electroosmotic Flow at Solid Surfaces

    KAUST Repository

    Shao, Sihong

    2012-01-01

    We develop a continuum hydrodynamic model for two-phase immiscible flows that involve electroosmotic effect in an electrolyte and moving contact line at solid surfaces. The model is derived through a variational approach based on the Onsager principle of minimum energy dissipation. This approach was first presented in the derivation of a continuum hydrodynamic model for moving contact line in neutral two-phase immiscible flows (Qian, Wang, and Sheng, J. Fluid Mech. 564, 333-360 (2006)). Physically, the electroosmotic effect can be formulated by the Onsager principle as well in the linear response regime. Therefore, the same variational approach is applied here to the derivation of the continuum hydrodynamic model for charged two-phase immiscible flows where one fluid component is an electrolyte exhibiting electroosmotic effect on a charged surface. A phase field is employed to model the diffuse interface between two immiscible fluid components, one being the electrolyte and the other a nonconductive fluid, both allowed to slip at solid surfaces. Our model consists of the incompressible Navier-Stokes equation for momentum transport, the Nernst-Planck equation for ion transport, the Cahn-Hilliard phase-field equation for interface motion, and the Poisson equation for electric potential, along with all the necessary boundary conditions. In particular, all the dynamic boundary conditions at solid surfaces, including the generalized Navier boundary condition for slip, are derived together with the equations of motion in the bulk region. Numerical examples in two-dimensional space, which involve overlapped electric double layer fields, have been presented to demonstrate the validity and applicability of the model, and a few salient features of the two-phase immiscible electroosmotic flows at solid surface. The wall slip in the vicinity of moving contact line and the Smoluchowski slip in the electric double layer are both investigated. © 2012 Global-Science Press.

  18. Transport mechanisms and wetting dynamics in molecularly thin films of long-chain alkanes at solid/vapour interface : relation to the solid-liquid phase transition

    OpenAIRE

    Lazar, Paul

    2005-01-01

    Wetting and phase transitions play a very important role our daily life. Molecularly thin films of long-chain alkanes at solid/vapour interfaces (e.g. C30H62 on silicon wafers) are very good model systems for studying the relation between wetting behaviour and (bulk) phase transitions. Immediately above the bulk melting temperature the alkanes wet partially the surface (drops). In this temperature range the substrate surface is covered with a molecularly thin ordered, solid-like alkane film (...

  19. Temperature-composition-order parameter phase diagram for compositionally ordering solid solutions of lead scandium niobate - lead scandium tantalate

    International Nuclear Information System (INIS)

    It is established that the temperature of ferroelectric phase transition in crystals of lead scandium niobate - lead scandium tantalate ordering solid solutions both with low - and high order parameters has a linear dependence on the composition x. On the basis of the data obtained for the first time the phase diagram T-x-S is calculated for these solid solutions

  20. A photolabile linker for the solid-phase synthesis of 4-substituted NH-1,2,3-triazoles

    DEFF Research Database (Denmark)

    Qvortrup, Katrine; Nielsen, Thomas Eiland

    2011-01-01

    A novel photolabile linker for solid-phase synthesis is presented. The linker displays an azido handle for copper-catalyzed azide–alkyne cycloaddition reactions with a variety of alkynes, remains intact under typical solid-phase reaction conditions, and enables a mild photolytic release of 4-subs......-substituted NH-triazoles in high purity and yield....

  1. Development of solid-phase extraction and solid-phase microextraction methods for the determination of chlorophenols in cork macerate and wine samples.

    Science.gov (United States)

    Insa, S; Salvadó, V; Anticó, E

    2004-08-20

    Tri-, tetra- and pentachlorophenol (TCP, TeCP and PCP) can be considered the precursors in the formation of corresponding chloroanisoles, known to be powerful odorants in corks and wine. Determining the presence of these chlorophenolic compounds in cork soaking solutions (ethanol/water mixtures, 12% (v/v) ethanol used for cork quality control testing), or in wine can be achieved by acetylation/gas chromatography electron-capture detection. In order to reach the required sensitivity, a previous preconcentration step is necessary. Solid-phase extraction (SPE) and headspace solid-phase microextraction (HS-SPME) have given good results for the preconcentration of TCP, TeCP and PCP in such matrices. The use of Oasis HLB cartridges gives acceptable recoveries for the three compounds when different volumes (50-250 mL) of cork macerate with concentrations ranging from 20 to 150 ng/L are processed. Preconcentration based on HS-SPME has also been optimised with a 100 microm polydimethylsiloxane fibre and in situ derivatization. The HS-SPME method allows chlorophenols in a cork soaking solution and in wine to be determined with a limit of detection of 1 ng/L for each compound (in cork macerate) and a repeatability of around 0.5%-5% (n=8) for a concentration level of 30 ng/L. PMID:15481456

  2. Ethanol/Water extraction combined with solid-phase extraction and solid-phase microextraction concentration for the determination of chlorophenols in cork stoppers.

    Science.gov (United States)

    Insa, Sara; Besalú, Emili; Iglesias, Cristina; Salvadó, Victoria; Anticó, Enriqueta

    2006-02-01

    The appearance of 2,4,6-trichloroanisole (TCA) in cork stoppers is of great concern because it can cause off-flavors in bottled wine. To prevent this sensorial defect, there should not be any traces of 2,4,6-trichlorophenol (TCP), 2,3,4,6-tetrachlorophenol (TeCP), or pentachlorophenol (PCP) in the finished corks, because they are the direct precursors of TCA. In the course of this study two methodologies based upon an extraction with ethanol/water mixtures to determine the chlorophenolic content in cork matrices were developed. The cork extract is preconcentrated using both solid-phase extraction and solid-phase microextraction methodologies. The latter was optimized by applying a full two-level factorial design. Finally, spiked ground corks at nanogram per gram levels of each chlorophenol were analyzed under optimal conditions and by applying both procedures. The obtained results demonstrate that chlorophenols can be detected in corks contaminated at the nanogram per gram level and, thus, these approaches can be successfully applied as quality control measures in the cork industry. PMID:16448159

  3. Solid–solid transformations via nanoscale intermediate interfacial phase: Multiple structures, scale and mechanics effects

    International Nuclear Information System (INIS)

    Solid–solid (SS) phase transformations via nanometer-size intermediate melts (IMs) within the SS interface, hundreds of degrees below melting temperature, were predicted thermodynamically and are consistent with experiments for various materials. A necessary condition for the appearance of IMs, using a sharp interface approach, was that the ratio of the energies of SS and solid–melt (SM) interfaces, kE, were >2. Here, an advanced phase-field approach coupled with mechanics is developed that reveals various new scale and interaction effects and phenomena. Various types of IM are found: (i) continuous and reversible premelting and melting; (ii) jump-like barrierless transformation to IMs, which can be kept at much lower temperature even for kEEEE=1. The theory developed here can be tailored for diffusive phase transformations, formation of intergranular and interfacial phases, and surface-induced phase transformations

  4. Synthesis of silicon carbide nanowires by solid phase source chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    NI Jie; LI Zhengcao; ZHANG Zhengjun

    2007-01-01

    In this paper,we report a simple approach to synthesize silicon carbide(SiC)nanowires by solid phase source chemical vapor deposition(CVD) at relatively low temperatures.3C-SiC nanowires covered by an amorphous shell were obtained on a thin film which was first deposited on silicon substrates,and the nanowires are 20-80 am in diameter and several μm in length,with a growth direction of[200].The growth of the nanowires agrees well on vapor-liquid-solid (VLS)process and the film deposited on the substrates plays an important role in the formation of nanowires.

  5. Effects of potassium nitrate on the solid phase transitions of ammonium nitrate particles

    Science.gov (United States)

    Wu, Hong Bo; Chan, Chak K.

    Ammonium nitrate (NH 4NO 3) is a common constituent of atmospheric particulate pollutants. It exists in five stable polymorphic forms, designated as phases V, IV, III, II and I, below its melting point of 170 °C. In atmospheric research, very little attention has been paid to the solid phase transitions of NH 4NO 3 because phase IV NH 4NO 3 particles are stable over a wide range of tropospheric temperatures. Potassium nitrate (KNO 3) is often found to co-exist with NH 4NO 3 in atmospheric aerosols, and it can change the phase transition behaviors of solid NH 4NO 3 particles. In this study, we investigated the effects of KNO 3 on the solid phase transitions of NH 4NO 3 particles using in situ microscopic Raman spectroscopy. Both the transition path and transition temperature of NH 4NO 3 single particles (40-700 μm) depend on the KNO 3 mass percentage and the particle size. With the addition of KNO 3, the IV→II transition, which appears at 52 °C for pure NH 4NO 3 particles, is replaced by the IV→III transition. The KNO 3 mass percentage required for this change in transition path increases with decreasing particle size and the transition temperature decreases with increasing KNO 3 mass percentage. At a relatively high mass percentage of KNO 3 (⩾7.4 wt%), the KNO 3/NH 4NO 3 mixed particles undergo the IV→III transition under ambient temperatures, or even crystallize directly in phase III from droplets with a further increase in the mass percentage of KNO 3. Submicron KNO 3/NH 4NO 3 particles crystallize to phase IV at low KNO 3 mass percentages (⩽5.7 wt%) but to phase III at higher KNO 3 mass percentages (⩾7.4 wt%). These results suggest that atmospheric solid NH 4NO 3 particles may exist in phase III and the phase transitions should not be ignored in atmospheric chemical models.

  6. Formation of organic solid phases in hydrocarbon reservoir fluids. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, S.I.; Lindeloff, N.; Stenby, E.H.

    1998-12-31

    The occurrence of solid phases during oil recovery is a potential problem. The present work has mainly been concerned with wax formation due to cooling of oils with a large paraffin content. 8 oils have been included in this project, although only a few of these have till now been subject to all the experimental techniques applied. The oils and wax fractions from these have been characterized using techniques such as GC-MS and Ftir. The goal has in part been to get a detailed description of the oil composition for use in model evaluation and development and in part to get a fundamental understanding of waxy oil properties and behaviour. A high pressure (200 bar) equipment has been developed for automatic detection of wax appearance using a filtration technique and laser light turbidimetry. The latter was found to be far superior to the filtration. The filtration was used to sample the incipient solid phase for characterization. However entrapment of liquid in the filters currently used have hampered this part. A number of model systems and one gas condensate have been investigated. The GC-MS procedure was found only to been able to detect molecules up to n-C45 and the group type analysis was not accurate enough for modelling purposes. Using Ftir it was obvious that incipient phases may contain very complex molecules (asphaltenes) which are not captured by GC-MS especially when fractionation is done using the acetone precipitation at elevated temperature. The latter fractionation procedure has been investigated thoroughly as a tool for understanding wax distribution etc. Within thermodynamic modelling a delta lattice parameter model has been developed which incorporates the non-ideality of the solid phases into the calculation of SLE. The non-ideality is estimated from pure component properties. A new algorithm for phase equilibria involving gas-liquid-solid has been developed. Currently both the model work and the experimental works are continued. (au)

  7. Electron Shuttling Capacity of Solid-Phase Organic Matter in Forest Soils

    Science.gov (United States)

    Patel, A.; Zhao, Q.; Yang, Y.

    2015-12-01

    Soil organic matter, as an electron shuttle, plays an important role in regulating the biogeochemical cycles of metals, especially the redox reactions for iron. Microorganisms can reduce soil organic matter under anaerobic conditions, and biotically-reduced soil organic matter can abiotically donate electrons to ferric oxides. Such soil organic matter-mediated electron transport can facilitate the interactions between microorganisms and insoluble terminal electron acceptors, i.e. iron minerals. Most previous studies have been focused on the electron shuttling processes through dissolved soil organic matter, and scant information is available for solid-phase soil organic matter. In this study, we aim to quantify the electron accepting capacity for solid-phase organic matter in soils collected from four different forests in the United States, including Truckee (CA), Little Valley (NV), Howland (ME) and Hart (MI). We used Shewanella oneidensisMR-1 to biotically reduce soil slurries, and then quantified the electrons transferred to solid-phase and solution-phase organic matter by reacting them with Fe(III)-nitrilotriacetic acid (Fe(III)-NTA). The generation of Fe(II) was measured by a ferrozine assay to calculate the electron accepting capacity of soil organic matter. Our preliminary results showed that the Truckee soil organic matter can accept 0.51±0.07 mM e-/mol carbon. We will measure the electron accepting capacity for four different soils and correlate them to the physicochemical properties of soils. Potential results will provide information about the electron accepting capacity of solid-phase soil organic matter and its governing factors, with broad implication on the coupled biogeochemical cycles of carbon and iron.

  8. Mesomorphism in columnar phases studied by solid-state nuclear magnetic resonance.

    Science.gov (United States)

    Dvinskikh, Sergey V; Thaning, Johan; Stevensson, Baltzar; Jansson, Kjell; Kumar, Sandeep; Zimmermann, Herbert; Maliniak, Arnold

    2006-08-01

    In this paper, we present 13C and 1H NMR investigations of 2, 3, 6, 7, 10, 11-hexahexyl-thiotriphenylene (HHTT). The measurements were carried out under both static and magic-angle spinning conditions. The phase diagram of HHTT is KHD(hd)I , where H is a helical phase and D(hd) is a columnar liquid crystal. The motivation was to characterize the molecular order and dynamics and to investigate differences at the molecular level between the two mesophases: H and D(hd). It is shown that D(hd) is a conventional columnar liquid crystal, where the molecular core undergoes fast rotation about the symmetry axis. The orientational order in this mesophase is lower and the temperature dependence of the order parameter is steeper than in other triphenylene-based compounds. On the other hand, in the helical phase the core, similarly to the solid phase, is essentially rigid. The difference between the solid and helical phases is mainly manifested in an increased mobility of the aliphatic chains observed in the latter phase. In addition, the sample exhibits thermal history effects, which are observed in the different behavior upon cooling and heating. PMID:17025448

  9. Solid Phase Characterization Of Heel Samples From Tank 241-C-110

    International Nuclear Information System (INIS)

    During sluicing operations of tank 241-C-110, a significant amount of solids were unable to be retrieved. These solids (often referred to as the tank 'heel') were sampled in 2010 and chemically and mineralogically analyzed in the 222-S Laboratory. Additionally, dissolution tests were performed to identify the amount of undissolvable material after using multiple water contacts. This report covers the solid phase characterization of six samples from these tests using scanning electron microscopy, polarized light microscopy, and X-ray diffraction. The chemical analyses, particle size distribution analysis, and dissolution test results are reported separately. Two of the samples were from composites created from as-received material - Composite A and Composite B. The main phase in these samples was sodium-fluoride-phosphate hydrate (natrophosphate) - in the X-ray diffraction spectra, this phase was the only phase identifiable. Polarized light microscopy showed the presence of minor amounts of gibbsite and other phases. These phases were identified by scanning electron microscopy - energy dispersive X-ray spectroscopy as sodium aluminosilicates, sodium diuranate, and sodium strontium phosphate hydrate (nastrophite) crystals. The natrophosphate crystals in the scanning electron microscopy analysis showed a variety of erosive and dissolution features from perfectly shaped octahedral to well-rounded appearance. Two samples were from water-washed Composites A and B, with no change in mineralogy compared to the as-received samples. This is not surprising, since the water wash had only a short period of water contact with the material as opposed to the water dissolution tests. The last two samples were residual solids from the water dissolution tests. These tests included multiple additions of water at 15 C and 45 C. The samples were sieved to separate a coarser fraction of > 710 μm and a finer fraction of < 710 μm. These two fractions were analyzed separately. The coarser

  10. SOLID PHASE CHARACTERIZATION OF HEEL SAMPLES FROM TANK 241-C-110

    Energy Technology Data Exchange (ETDEWEB)

    PAGE JS; COOKE GA; PESTOVICH JA; HUBER HJ

    2011-12-01

    During sluicing operations of tank 241-C-110, a significant amount of solids were unable to be retrieved. These solids (often referred to as the tank 'heel') were sampled in 2010 and chemically and mineralogically analyzed in the 222-S Laboratory. Additionally, dissolution tests were performed to identify the amount of undissolvable material after using multiple water contacts. This report covers the solid phase characterization of six samples from these tests using scanning electron microscopy, polarized light microscopy, and X-ray diffraction. The chemical analyses, particle size distribution analysis, and dissolution test results are reported separately. Two of the samples were from composites created from as-received material - Composite A and Composite B. The main phase in these samples was sodium-fluoride-phosphate hydrate (natrophosphate) - in the X-ray diffraction spectra, this phase was the only phase identifiable. Polarized light microscopy showed the presence of minor amounts of gibbsite and other phases. These phases were identified by scanning electron microscopy - energy dispersive X-ray spectroscopy as sodium aluminosilicates, sodium diuranate, and sodium strontium phosphate hydrate (nastrophite) crystals. The natrophosphate crystals in the scanning electron microscopy analysis showed a variety of erosive and dissolution features from perfectly shaped octahedral to well-rounded appearance. Two samples were from water-washed Composites A and B, with no change in mineralogy compared to the as-received samples. This is not surprising, since the water wash had only a short period of water contact with the material as opposed to the water dissolution tests. The last two samples were residual solids from the water dissolution tests. These tests included multiple additions of water at 15 C and 45 C. The samples were sieved to separate a coarser fraction of > 710 {mu}m and a finer fraction of < 710 {mu}m. These two fractions were analyzed

  11. Radioimmunoassay of diagoxin with the aid of the solid phase - microtitre plating technique

    International Nuclear Information System (INIS)

    Preliminary results are reported here on the development of a digoxin-radioimmunoassay with an anti-digoxin antibody (goat) in a solid phase technique (mictrotitre plate). The advantages compared to conventional RIAs are: Cross reactions towards digoxin is minimal, both in vitro and in vivo. The calibraton range extends from 0.25 to 8 ng/ml. The radioactive load could be reduced significantly by use of smaller amounts of tracer (0.004 μCi/single determination) and by reduction of waste volume (solid), waste weight (solid) and liquid waste. The DIGOXIN RIA BIOTEST MTP is, in addition, the only digoxin radioimmunoassay where radioactive waste is produced in a sealed form. The test is a simple one and can be carried out without the need for complicated apparatus and techniques. (orig./MG)

  12. Radioactivity concentration in liquid and solid phases of scale and sludge generated in the petroleum industry.

    Science.gov (United States)

    Paranhos Gazineu, Maria Helena; de Araújo, Andressa Arruda; Brandão, Yana Batista; Hazin, Clovis Abrahão; de O Godoy, José Marcos

    2005-01-01

    Scales and sludge generated during oil extraction and production can contain uranium, thorium, radium and other natural radionuclides, which can cause exposure of maintenance personnel. This work shows how the oil content can influence the results of measurements of radionuclide concentration in scale and sludge. Samples were taken from a PETROBRAS unit in Northeast Brazil. They were collected directly from the inner surface of water pipes or from barrels stored in the waste storage area of the E&P unit. The oil was separated from the solids with a Soxhlet extractor by using aguarras at 90+/-5 degrees C as solvent. Concentrations of 226Ra and 228Ra in the samples were determined before and after oil extraction by using an HPGe gamma spectrometric system. The results showed an increase in the radionuclide concentration in the solid (dry) phase, indicating that the above radionuclides concentrate mostly in the solid material. PMID:15748660

  13. Bubble-to-dense-phase mass transfer kinetics in gas-solid fluidized beds

    International Nuclear Information System (INIS)

    The heterogeneously catalyzed oxidation of carbon monoxide was used as a model reaction to study the mass transfer characteristics of a gas-solid fluidized bed reactor. The conversion studies were performed in air-solids fluidized beds of 3 cm and 30 cm diameter, at a temperature ranging from 200 to 5500C. The solids used were mixtures of dense alumina and impregnated porous alumina and a minimum fluidization velocity, u/sub mf/, of 0.0016, 0.018, 0.085 and 0.21 m/s. The results were compared with an extended two phase fluid bed model applying Davidson's mass transfer correlation, Darton's bubble growth relation and Werther's bubble rise velocity correlation. It was experimentally confirmed, that the contribution of the convective term in the mass transfer relation, increases with increasing u/sub mf/ and may become the dominant mass transfer mechanism

  14. Thermodynamic Model Formulations for Inhomogeneous Solids with Application to Non-isothermal Phase Field Modelling

    Science.gov (United States)

    Gladkov, Svyatoslav; Kochmann, Julian; Reese, Stefanie; Hütter, Markus; Svendsen, Bob

    2016-04-01

    The purpose of the current work is the comparison of thermodynamic model formulations for chemically and structurally inhomogeneous solids at finite deformation based on "standard" non-equilibrium thermodynamics [SNET: e. g. S. de Groot and P. Mazur, Non-equilibrium Thermodynamics, North Holland, 1962] and the general equation for non-equilibrium reversible-irreversible coupling (GENERIC) [H. C. Öttinger, Beyond Equilibrium Thermodynamics, Wiley Interscience, 2005]. In the process, non-isothermal generalizations of standard isothermal conservative [e. g. J. W. Cahn and J. E. Hilliard, Free energy of a non-uniform system. I. Interfacial energy. J. Chem. Phys. 28 (1958), 258-267] and non-conservative [e. g. S. M. Allen and J. W. Cahn, A macroscopic theory for antiphase boundary motion and its application to antiphase domain coarsening. Acta Metall. 27 (1979), 1085-1095; A. G. Khachaturyan, Theory of Structural Transformations in Solids, Wiley, New York, 1983] diffuse interface or "phase-field" models [e. g. P. C. Hohenberg and B. I. Halperin, Theory of dynamic critical phenomena, Rev. Modern Phys. 49 (1977), 435-479; N. Provatas and K. Elder, Phase Field Methods in Material Science and Engineering, Wiley-VCH, 2010.] for solids are obtained. The current treatment is consistent with, and includes, previous works [e. g. O. Penrose and P. C. Fife, Thermodynamically consistent models of phase-field type for the kinetics of phase transitions, Phys. D 43 (1990), 44-62; O. Penrose and P. C. Fife, On the relation between the standard phase-field model and a "thermodynamically consistent" phase-field model. Phys. D 69 (1993), 107-113] on non-isothermal systems as a special case. In the context of no-flux boundary conditions, the SNET- and GENERIC-based approaches are shown to be completely consistent with each other and result in equivalent temperature evolution relations.

  15. Development of a solid phase technic for radioimmunoassay of triiodothyronine (T3) in serum

    International Nuclear Information System (INIS)

    We have developed a solid phase radioimmunoassay (RIA) system for triiodothyronine (T3), by immobilizing triiodothyronine antibodies on the inner wall of reaction tubes. The antibody-coated tubes were made via reaction of antibody with glutaraldeyde residue pre coated on the inner wall of the tubes by alkaline self-polimerization. The quality of the coated tubes was tested through its performance in the RIA methodology, by analysing the following RIA parameters: minimum detectable dose (MDD), nonspecific binding (NSB), ''X50%'', slope of the standard curve, intra and inter-assay precision, accuracy of the method and figure of merit. The serum levels of T3 in hypothyroid and hyperthyroid patients and the normal values range were determined for the solid phase RIA system. The results are in agreement with found in the literature. (author)

  16. Micro-solid phase extraction of ochratoxin A, and its determination in urine using capillary electrophoresis

    International Nuclear Information System (INIS)

    We describe a simple, environmentally friendly and selective technique for the determination of ochratoxin A (OTA) in urine. It involves (a) the use of a molecularly imprinted polymer as a sorbent in micro-solid-phase extraction in which the sorbent is contained in a propylene membrane envelope, and (b) separation and detection by capillary electrophoresis (CE). Under optimized conditions, response is linear in the range between 50 and 300 ng mL−1 (with a correlation coefficient of 0.9989), relative standard deviations range from 4 to 8 %, the detection limit for OTA in urine is 11.2 ng mL−1 (with a quantification limits of 32.5 ng mL−1) which is lower than those of previously reported methods for solid-phase extraction combined with CE. The recoveries of OTA from urine spiked at levels of 50, 150 and 300 ng mL−1 ranged from 93 to 97 %. (author)

  17. The effect of potassium on the rate of solid phase epitaxy in silicon

    International Nuclear Information System (INIS)

    Rutherford backscattering spectroscopy and ion channeling and secondary ion mass spectroscopy have been used to study the evolution of a potassium profile in amorphous silicon during solid phase epitaxial crystallisation. The potassium profile exhibits some propensity for refinement in front of the crystallising interface for the concentrations used in this experiment. Also, the potassium is partially substitutional in the crystallised layer. Preliminary studies on the influence of potassium on the rate of solid phase epitaxy (SPE) in silicon are presented. Surface amorphous films doped with potassium were crystallised and the rate of epitaxy was monitored using time resolved reflectivity. The inclusion of potassium was found to retard the rate of SPE. These results indicate that potassium doped amorphous films may be helpful in efforts to further refine present models of SPE in silicon

  18. Solid phase epitaxy amorphous silicon re-growth: some insight from empirical molecular dynamics simulation

    CERN Document Server

    Krzeminski, Christophe; 10.1140/epjb/e2011-10958-7

    2011-01-01

    The modelling of interface migration and the associated diffusion mechanisms at the nanoscale level is a challenging issue. For many technological applications ranging from nanoelectronic devices to solar cells, more knowledge of the mechanisms governing the migration of the silicon amorphous/crystalline interface and dopant diffusion during solid phase epitaxy is needed. In this work, silicon recrystallisation in the framework of solid phase epitaxy and the influence on orientation effects have been investigated at the atomic level using empirical molecular dynamics simulations. The morphology and the migration process of the interface has been observed to be highly dependent on the original inter-facial atomic structure. The [100] interface migration is a quasi-planar ideal process whereas the cases [110] and [111] are much more complex with a more diffuse interface. For [110], the interface migration corresponds to the formation and dissolution of nanofacets whereas for [111] a defective based bilayer reor...

  19. Development of solid phase radioimmunoassay system using new polymeric magnetic micro-spheres

    International Nuclear Information System (INIS)

    Magnetic particles were locally prepared by co-precipitation of Fe2+ and Fe3+ in an ammonia solution. The prepared microsphere were grafted with polyacrylamide acrylic acid by using gamma irradiation polymerization in presence of MBA as a cross linker. AFP antibody was immobilized on these beads and used as a solid phase in radioimmunoassay technique. The immunoreactivity of the developed assay was found to be influenced by different factors such as solid phase volume, incubation time, incubation temperature and storage period. A comparative study was performed between the developed assay system and others two ones. The maximum binding percent attained the value of 19.5% while the sensitivity was observed to be 1.3 IU/mL. The developed assay displayed acceptable precision estimated by repeated analysis of the quality control samples and the clinical samples analyzed by this assay showed a good correlation with that commercial kit (r = 0.998). (author)

  20. Solid phase graft copolymerization of acrylic monomers onto thermoplastics and their use as blend compatibilizers

    Science.gov (United States)

    Subramanian, Srinivas

    This research work is an extension of some of the earlier work done on the development of solid phase grafting technique to graft various monomers onto polymers as well as postulation of the usefulness of the graft copolymers thus synthesized. Polystyrene grafted with acrylic acid, previously developed in bench scale, was synthesized in pilot-plant scale batches. Process parameter studies on the grafting of acrylic acid onto polypropylene and developmental studies on the grafting of maleic anhydride onto polystyrene were also done. Polymers grafted with polar molecules such as maleic anhydride and acrylic acid have been used to compatibilize immiscible blends of polar and non-polar polymers. On the same note, the applicability of the solid phase graft copolymers as blend compatibilizers were investigated and their performance was compared to commercially available compatibilizers. Solid phase graft copolymerization process is a technique to synthesize graft copolymers. Some of its salient features are use of minimal solvent to conduct the reaction and easy equipment modification. It is a low pressure and low temperature process. This technique provides a viable alternative to the environmentally hazardous, and time consuming conventional process currently in use. Hence, development of this technique could be beneficial not only to the plastics industry, but also to mankind. Also, this technique provides a low-cost and extremely easy method to develop graft copolymers such as acrylic acid functionalized polymers that are rapidly gaining popularity as blend compatibilizers and polymer reinforcing agents. A study that proves the potential of these solid phase graft copolymers as good blend compatibilizers for industrially important immiscible polymers will develop interest in the industries about this grafting process. The free radical solid phase graft copolymerization process was carried in a modified Brabender-type mixer fitted with specially designed blades to

  1. Silica-Based Solid Phase Extraction of DNA on a Microchip

    Institute of Scientific and Technical Information of China (English)

    陈晓芳; 沈科跃; 刘鹏; 郭旻; 程京; 周玉祥

    2004-01-01

    Micro total analysis systems for chemical and biological analysis have attracted much attention.However,microchips for sample preparation and especially DNA purification are still underdeveloped.This work describes a solid phase extraction chip for purifying DNA from biological samples based on the adsorption of DNA on bare silica beads prepacked in a microchannel.The chip was fabricated with poly-dimethylsiloxane.The silica beads were packed in the channel on the chip with a tapered microchannel to form the packed bed.Fluorescence detection was used to evaluate the DNA adsorbing efficiency of the solid phase.The polymerase chain reaction was used to evaluate the quality of the purified DNA for further use.The extraction efficiency for the DNA extraction chip is approximately 50% with a 150-nL extraction volume.Successful amplification of DNA extracted from human whole blood indicates that this method is compatible with the polymerase chain reaction.

  2. A Facile, Choline Chloride/Urea Catalyzed Solid Phase Synthesis of Coumarins via Knoevenagel Condensation

    Directory of Open Access Journals (Sweden)

    Hosanagara N. Harishkumar

    2011-01-01

    Full Text Available The influence of choline chloride/urea ionic liquid in solid phase on the Knoevenagel condensation is demonstrated. The active methylene compounds such as meldrum’s acid, diethylmalonate, ethyl cyanoacetate, dimethylmalonate, were efficiently condensed with various salicylaldehydes in presence of choline chloride/urea ionic liquid without using any solvents or additional catalyst. The reaction is remarkably facile because of the air and water stability of the catalyst, and needs no special precautions. The reactions were completed within 1hr with excellent yields (95%. The products formed were sufficiently pure, and can be easily recovered. The use of ionic liquid choline chloride/urea in solid phase offered several significant advantages such as low cost, greater selectivity and easy isolation of products.

  3. Solid-phase radioimmunoassay of immunoglobulins G, A and M: applicability in analysis of sucrose gradients

    Energy Technology Data Exchange (ETDEWEB)

    Eriksen, E.F.; Danielsen, H. (Aarhus Kommunehospital (Denmark). Medical Department C); Johansen, A.S. (Aarhus Univ. (Denmark). Institute of Medical Biochemistry); Larsson, L.I. (Unit of Histochemistry, University Institute of Pathology, Copenhagen, Denmark)

    1984-01-01

    A simple and sensitive solid-phase radioimmunoassay for the detection of immunoglobulins G, A and M in sucrose gradients is described. The solid-phase consisted of immunoglobulins adsorbed to polystyrene tubes. Using buffers without detergent and /sup 125/I-labeled sheep anti-rabbit IgA as radioligand, the assay was able to detect 0.8 ng per tube in the IgG assay and 1.6 ng per tube in the IgA and IgM assays. Standard curves with antigen dissolved in 10% and 32% sucrose were superimposable and did not deviate from standard curves with antigen dissolved in buffer without sucrose. Using these techniques on ultracentrifugation samples from patients with systemic lupus erythematosus, Schoenlein-Henoch nephritis and IgA glorulonephritis is was possible to detect both immunoglobulin fragments and immunoglobulin aggregates at the same time without prior dialysis of the samples.

  4. Development of a solid phase technique for radioimmunoassay for triiodothyronine (T3) in serum

    International Nuclear Information System (INIS)

    We have developed a solid phase radioimmunoassay (RIA) system for triiodothyronine (T3), by immobilizing triidothyronine antibodies on the inner wall of reaction tubes. The antibody-coated tubes were made via reaction of antibody with glutaraldeyde residue pre coated on the inner wall of the tubes by alkaline self-polimerization. The quality of the coated tubes was tested through its performance in the RIA methodology, by analysing the following RIA parameters: minimum detectable dose (DMD), nonspecific binding (NSB), ''X50%'', slope of the standard curve, intra and inter-assay precision, accuracy of the method and figure of merit. The serum levels of T3 in hypothyroid and hyperthyroid patients and the normal values range were determined for the solid phase RIA system. The results are in agreement with found in the literature. (author)

  5. The Use of Aryl Hydrazide Linkers for the Solid Phase Synthesis of Chemically Modified Peptides

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Y; Mitchell, A R; Camarero, J A

    2006-11-03

    Since Merrifield introduced the concept of solid phase synthesis in 1963 for the rapid preparation of peptides, a large variety of different supports and resin-linkers have been developed that improve the efficiency of peptide assembly and expand the myriad of synthetically feasible peptides. The aryl hydrazide is one of the most useful resin-linkers for the synthesis of chemically modified peptides. This linker is completely stable during Boc- and Fmoc-based solid phase synthesis and yet it can be cleaved under very mild oxidative conditions. The present article reviews the use of this valuable linker for the rapid and efficient synthesis of C-terminal modified peptides, head-to-tail cyclic peptides and lipidated peptides.

  6. Dense Pellicular Agarose-Glass Beads for Expanded Bed Application: Flow Hydrodynamics and Solid Phase Classifications

    Institute of Scientific and Technical Information of China (English)

    周鑫; 史清洪; 白姝; 孙彦

    2004-01-01

    Two dense pellicular agarose-glass matrices of different sizes and densities, i.e., AG-S and AG-L, have been characterized for their bed expansion behavior, flow hydrodynamics and particle classifications in an expanded bed system. A 26 mm ID column with side ports was used for sampling the liquid-solid suspension during expanded bed operations. Measurements of the collected solid phase at different column positions yielded the particle size and density distribution data. It was found that the composite matrices showed particle size as well as density classifications along the column axis, i.e., both the size and density of each matrix decreased with increasing the axial bed height. Their axial classifications were expressed by a correlation related to both the particle size and density as a function of the dimensionless axial bed height. The correlation was found to fairly describe the solid phase classifications in the expanded bed system. Moreover, it can also be applied to other two commercial solid matrices designed for expanded bed applications.

  7. The role of energetic processing on solid-phase chemistry in star forming regions

    Science.gov (United States)

    Palumbo, M. E.; Urso, R. G.; Kaňuchová, Z.; Scirè, C.; Accolla, M.; Baratta, G. A.; Strazzulla, G.

    2016-05-01

    It is generally accepted that complex molecules observed in star forming regions are formed in the solid phase on icy grain mantles and are released to the gas-phase after desorption of icy mantles. Most of our knowledge on the physical and chemical properties of ices in star forming regions is based on the comparison between observations and laboratory experiments performed at low temperature (10-100 K). Here we present some recent laboratory experiments which show the formation of (complex) molecular species after ion bombardment of simple ices.

  8. Free energy model for solid high-pressure phases of carbon

    International Nuclear Information System (INIS)

    Analytic free energy models for three solid high-pressure phases—diamond, body centered cubic phase with eight atoms in the unit cell (BC8), and simple cubic (SC)—are developed using density functional theory. We explicitly include anharmonic effects by performing molecular dynamics simulations and investigate their density and temperature dependence in detail. Anharmonicity in the nuclear motion shifts the phase transitions significantly compared to the harmonic approximation. Furthermore, we apply a thermodynamically constrained correction that brings the equation of state in accordance with diamond anvil cell experiments. The performance of our thermodynamic functions is validated against Hugoniot experiments. (paper)

  9. Free energy model for solid high-pressure phases of carbon

    Science.gov (United States)

    Schöttler, Manuel; French, Martin; Cebulla, Daniel; Redmer, Ronald

    2016-04-01

    Analytic free energy models for three solid high-pressure phases—diamond, body centered cubic phase with eight atoms in the unit cell (BC8), and simple cubic (SC)—are developed using density functional theory. We explicitly include anharmonic effects by performing molecular dynamics simulations and investigate their density and temperature dependence in detail. Anharmonicity in the nuclear motion shifts the phase transitions significantly compared to the harmonic approximation. Furthermore, we apply a thermodynamically constrained correction that brings the equation of state in accordance with diamond anvil cell experiments. The performance of our thermodynamic functions is validated against Hugoniot experiments.

  10. Hydrodynamic considerations on optimal design of a three-phase airlift bioreactor with high solids loading

    OpenAIRE

    Klein, Jaroslav; Vicente, A.A.; Teixeira, J.A.

    2003-01-01

    The hydrodynamic study of a three-phase airlift (TPAL) bioreactor with an enlarged gas–liquid dual separator was carried out. Different lengths and diameters of the draft tube were tested to show how the design of the separator zone affects the hydrodynamic performance of the TPAL reactor. Ca-alginate beads with entrapped yeast biomass at different loadings (0, 7, 14 and 21% v/v) were used in order to mimic the solid phase of conventional high cell density systems, such as those w...

  11. Effect of Microwave Radiation on Enzymatic and Chemical Peptide Bond Synthesis on Solid Phase

    Directory of Open Access Journals (Sweden)

    Alessandra Basso

    2009-01-01

    Full Text Available Peptide bond synthesis was performed on PEGA beads under microwave radiations. Classical chemical coupling as well as thermolysin catalyzed synthesis was studied, and the effect of microwave radiations on reaction kinetics, beads' integrity, and enzyme activity was assessed. Results demonstrate that microwave radiations can be profitably exploited to improve reaction kinetics in solid phase peptide synthesis when both chemical and biocatalytic strategies are used.

  12. Evaluation of a solid-phase immunofluorescence assay for detection of antibodies to Legionella pneumophila.

    OpenAIRE

    Thompson, T. A.; Wilkinson, H W

    1982-01-01

    A semiautomated solid-phase immunofluorescence technique (FIAX) was compared with the standard indirect immunofluorescence assay (IFA) for the determination of antibody levels to Legionella pneumophila serogroup 1 in paired human serum samples. The FIAX method was in agreement with the IFA test for 91.8% of the serum pairs but gave evidence of a recent Legionella infection significantly fewer times than did the IFA. These results suggest that the FIAX technique may eventually be a useful alte...

  13. A new linker for solid-phase synthesis of oligonucleotides with terminal phosphate group

    Czech Academy of Sciences Publication Activity Database

    Pačes, Ondřej; Točík, Zdeněk; Rosenberg, Ivan

    2008-01-01

    Roč. 73, č. 1 (2008), s. 32-43. ISSN 0010-0765 R&D Projects: GA ČR GA203/05/0827; GA ČR GA202/05/0628; GA MŠk LC512; GA MŠk(CZ) LC06077 Institutional research plan: CEZ:AV0Z40550506 Keywords : solid-phase synthesis * modified LCAA-CPG * oligonucleotide 3'-phosphates Subject RIV: CC - Organic Chemistry Impact factor: 0.784, year: 2008

  14. Preparation of high-quality poly-Si films by a solid phase crystallizing method

    CERN Document Server

    Yao Ruo He

    2002-01-01

    A solid phase crystallizing method has been developed to grow a Si crystal at temperatures as low as 550 degree C. Using this method, a high-quality thin-film polycrystalline silicon (Poly-Si) was obtained. The largest grain size, examined with X-ray diffraction spectroscopy and scanning electron microscopy images of recrystallized samples, is approximately 1 mu m for substrate temperature at 300 degree C and annealed at 550 degree C for 3 hours

  15. Solid phase carrier for radioimmuno analyses, as well as its manufacture and use

    International Nuclear Information System (INIS)

    The solid phase carrier is in the form of a tablet containing freeze-dried protein-bonded gel, dicalcium phosphate and magnesium stearate. It is able to absorb 0.400 microlitre of an a solution containing antigen-antibody. When contacted with the solution, the tablet swells up and adapts to the shape of the column. The carrier is suitable for the TSH RIA test. (DG)

  16. Solid-phase de novo synthesis of a (+/-)-2-deoxy-glycoside.

    Science.gov (United States)

    Lucchesi, Céline; Arboré, Amélie; Pascual, Sagrario; Fontaine, Laurent; Maignan, Christian; Dujardin, Gilles

    2010-04-19

    The solid-phase synthesis of methyl 2-deoxy-3-O-benzyl-D,L-arabino-hexopyranoside was achieved in a six-step sequence via a de novo strategy based on the hetero-Diels-Alder reaction of a vinyl ether supported on an azalactone-functionalized polystyrene resin, followed by the functional modification of the heteroadduct and the final release of the methyl glycoside by acidic solvolysis. PMID:20171610

  17. R. Bruce Merrifield and Solid-Phase Peptide Synthesis: A Historical Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, A R

    2007-12-04

    Bruce Merrifield, trained as a biochemist, had to address three major challenges related to the development and acceptance of solid-phase peptide synthesis (SPPS). The challenges were (1) to reduce the concept of peptide synthesis on a insoluble support to practice, (2) overcome the resistance of synthetic chemists to this novel approach, and (3) establish that a biochemist had the scientific credentials to effect the proposed revolutionary change in chemical synthesis. How these challenges were met is discussed in this article.

  18. Determination of fungicides in residual tanning floats using solid phase micro extraction

    OpenAIRE

    Font Vallès, Joaquim; Reyes Reyes, Maria; Cuadros, Sara; Bacardit Dalmases, Anna; Ollé Otero, Lluís; Marsal Monge, Agustín

    2013-01-01

    Solid-phase microextraction (SPME) was optimized for extraction of the leather preservative agents 2-(thiocyanomethylthio)-benzothiazole (TCMTB), 4-chloro-3-methylphenol (PCMC), 2-phenylphenol (OPP), 2-Octyl-3(2H)-isothiazolone (OIT), 2-mercaptobenzothiazol (MBT) and 3-iodo-2-propynyl-butylcarbamate (IPBC) in spent tanning floats. Determination was carried out by high performance liquid chromatography (HPLC) with photo diode array detection (PDA). The following parameters were studied to ach...

  19. Rapid Detection and Enumeration of Naegleria fowleri in Surface Waters by Solid-Phase Cytometry

    OpenAIRE

    Pougnard, Claire; Catala, Philippe; Drocourt, Jean-Louis; Legastelois, Stephane; Pernin, Pierre; Pringuez, Emmanuelle; Lebaron, Philippe

    2002-01-01

    A new method for the rapid and accurate detection of pathogenic Naegleria fowleri amoebae in surface environmental water was developed. The method is based on an immunofluorescent assay combined with detection by solid-phase cytometry. In this study we developed and compared two protocols using different reporter systems conjugated to antibodies. The monoclonal antibody Ac5D12 was conjugated with biotin and horseradish peroxidase, and the presence of cells was revealed with streptavidin conju...

  20. Design of indirect solid-phase immunosorbent methods for detecting arenavirus antigens and antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A.P.; Rezapkin, G.V.; Dzagurova, T.K.; Tkachenko, E.A.

    1984-05-01

    Specifications have been elaborated for formulating indirect solid-phase enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (SPRIA) methods that employ anti-human and anti-mice G class immunoglobulin (IgG), conjugated with horseradish peroxidase and /sup 125/I for detecting the arenaviruses Junin, Machupo, Tacaribe, Amalpari, Tamiami, Lassa, and LCM (lymphocytic choriomeningitis). These methods make it possible to identify with a high degree of sensitivity arenavirus antigens and antibodies in various kinds of material.

  1. Zirconyl chloride promoted highly efficient solid phase synthesis of amide derivatives

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An efficient solid phase route for the synthesis of amide derivatives by the reaction of carboxylic acids with urea in the presence of catalytic amount of zirconyl chloride under microwave irradiation conditions was described. In this way, a range of interesting amide derivatives was obtained in good to excellent yields. The catalyst was recycled with fresh reactants and it gave almost similar results without significant loss of activity up to the third run.

  2. A search for disordered (glassy) phase in solid 3He deformed in situ

    OpenAIRE

    Lisunov, A. A.; Maidanov, V. A.; Rubanskiy, V. Yu.; Rubets, S. P.; Rudavskii, E. Ya.; Rybalko, A. S.; Tikhii, V. A.

    2010-01-01

    A disordered (glassy) state has been searched in solid 3He deformed in the course of experiment employing precise measurements of pressure. The analysis of the temperature dependence of the crystal pressure measured at a constant volume shows that the main contribution to the pressure is made by the phonon subsystem, the influence of the disordered phase being very weak. Annealing of the deformed crystal does not affect this state. The results obtained differ greatly from the corresponding da...

  3. Copper-carbon nanocomposites prepared by solid-phase pyrolysis of copper phthalocyanine

    International Nuclear Information System (INIS)

    By using solid-phase pyrolysis of copper phthalocyanine we have prepared copper nanoparticles in carbon matrices. The elemental composition, structure and morphology of nanocomposites were investigated by scanning electron microscopy, energy dispersive X-ray microanalysis and X ray diffraction. Depending on the temperature and time of pyrolysis the sizes of copper nanoparticles can be varied from 10 nm to 400 nm. The structure of carbon matrices also strongly depends on the pyrolysis conditions, which allows to synthesize nanocomposites with given properties

  4. Modification of guanine bases by nucleoside phosphoramidite reagents during the solid phase synthesis of oligonucleotides.

    OpenAIRE

    Pon, R T; Damha, M J; Ogilvie, K K

    1985-01-01

    Nucleoside 3'-phosphoramidite and chlorophosphite reagents have been found to react with the lactam function of guanine. This reaction caused unsatisfactory results when oligodeoxyribonucleotides containing a large number of guanine bases were prepared in an automated solid phase synthesizer. The guanine modification is unstable, and leads to depurination and chain cleavage. This side reaction can be eliminated by protecting the O6-position. A new O6-p-nitrophenylethyldeoxyguanosine phosphora...

  5. Kinetics of solid state phase transformations: Measurement and modelling of some basic issues

    Indian Academy of Sciences (India)

    S Raju; E Mohandas

    2010-01-01

    A brief review of the issues involved in modelling of the solid state transformation kinetics is presented. The fact that apart from the standard thermodynamic parameters, certain path variables like heating or cooling rate can also exert a crucial influence on the kinetic outcome is stressed. The kinetic specialties that are intrinsic to phase changes proceeding under varying thermal history are enumerated. A simple and general modelling methodology for understanding the kinetics of non-isothermal transformations is outlined.

  6. Solid-phase extraction approach in comprehensive analysis of wort and beer samples

    Czech Academy of Sciences Publication Activity Database

    Čmelík, Richard; Žídková, Jitka; Bobálová, Janette

    Praha : Institute of Chemical Technology, 2011 - (Pulkrabová, J.; Tomaniová, M.). s. 237 ISBN 978-80-7080-795-8. [International Symposium on Recent Advances in Food Analysis /5./. 01.11.2011-04.11.2011, Praha] R&D Projects: GA MŠk 1M06030; GA MŠk 1M0570 Institutional research plan: CEZ:AV0Z40310501 Keywords : solid phase extraction * carbohydrates * beer Subject RIV: CB - Analytical Chemistry, Separation

  7. Solid phase microextraction for profiling volatile compounds in liquered white wines

    OpenAIRE

    Henryk H. Jeleń; Anna Szczurek

    2010-01-01

    Background. Profile of volatile compounds is a distinct feature of wine, which is dependent on the type of wine, grapes, fermentation and ageing processes. Profiling volatile compounds in wine using fast method provides information on major groups of compounds and can be used for classification/differentiation purposes. Solid phase microextraction (SPME) was used for the profiling of volatile compounds in liquered white wines in this study. Material and methods. Different fibers were tes...

  8. Phase I study of afatinib combined with nintedanib in patients with advanced solid tumours

    Science.gov (United States)

    Bahleda, Rastislav; Hollebecque, Antoine; Varga, Andrea; Gazzah, Anas; Massard, Christophe; Deutsch, Eric; Amellal, Nadia; Farace, Françoise; Ould-Kaci, Mahmoud; Roux, Flavien; Marzin, Kristell; Soria, Jean-Charles

    2015-01-01

    Background: This Phase I study evaluated continuous- and intermittent-dosing (every other week) of afatinib plus nintedanib in patients with advanced solid tumours. Methods: In the dose-escalation phase (n=45), maximum tolerated doses (MTDs) were determined for continuous/intermittent afatinib 10, 20, 30 or 40 mg once daily plus continuous nintedanib 150 or 200 mg twice daily. Secondary objectives included safety and efficacy. Clinical activity of continuous afatinib plus nintedanib at the MTD was further evaluated in an expansion phase (n=25). Results: The most frequent dose-limiting toxicities were diarrhoea (11%) and transaminase elevations (7%). Maximum tolerated doses were afatinib 30 mg continuously plus nintedanib 150 mg, and afatinib 40 mg intermittently plus nintedanib 150 mg. Treatment-related adverse events (mostly Grade ⩽3) included diarrhoea (98%), asthenia (64%), nausea (62%) and vomiting (60%). In the dose-escalation phase, two patients had partial responses (PRs) and 27 (60%) had stable disease (SD). In the expansion phase, one complete response and three PRs were observed (all non-small cell lung cancer), with SD in 13 (52%) patients. No pharmacokinetic interactions were observed. Conclusions: MTDs of continuous or intermittent afatinib plus nintedanib demonstrated a manageable safety profile with proactive management of diarrhoea. Antitumour activity was observed in patients with solid tumours. PMID:26512876

  9. Measurements on Melting Pressure, Metastable Solid Phases, and Molar Volume of Univariant Saturated Helium Mixture

    Science.gov (United States)

    Rysti, J.; Manninen, M. S.; Tuoriniemi, J.

    2014-06-01

    A concentration-saturated helium mixture at the melting pressure consists of two liquid phases and one or two solid phases. The equilibrium system is univariant, whose properties depend uniquely on temperature. Four coexisting phases can exist on singular points, which are called quadruple points. As a univariant system, the melting pressure could be used as a thermometric standard. It would provide some advantages compared to the current reference, namely pure He, especially at the lowest temperatures below 1 mK. We have extended the melting pressure measurements of the concentration-saturated helium mixture from 10 to 460 mK. The density of the dilute liquid phase was also recorded. The effect of the equilibrium crystal structure changing from hcp to bcc was clearly seen at mK at the melting pressure MPa. We observed the existence of metastable solid phases around this point. No evidence was found for the presence of another, disputed, quadruple point at around 400 mK. The experimental results agree well with our previous calculations at low temperatures, but deviate above 200 mK.

  10. The contribution of solid-state chemistry in the determination of multicomponent phase diagrams

    Institute of Scientific and Technical Information of China (English)

    Jean Claude Tedenac; Franck Gascoin; Didier Ravot

    2006-01-01

    For a long period of time, the determination of phase diagrams was only supported by experiments related to thermal effects or thermodynamic measurements: thermal analysis, calorimetric measurements, vapor pressures, and EMF measurements. As a matter of fact, solid-solid transformations were not so accurately determined and could not be taken into account in the system's analysis. First, X-ray diffraction methods were used as a support for the thermal analysis. Sec ond, the implementation of novel tools in structural analysis (for example, the Rietveld method) has permitted to increase the knowledge of phase stability. Finally, modeling the phases using a Calphad method needed increasingly more structural results to determine and better understand the phase diagrams. On the other hand, the Calphad method has been widely developed for metallic systems, for oxide systems, and in the past 10 years, for some semi-conductor systems, for example,gallium arsenide, cadmium telluride, and lead telluride systems. In such applications, it is very important to bring point defects in the modeling of the phases to map the defects as a function of the chemical composition. Owing to its complexity,this characteristic, the knowledge of which is crucial for the understanding and the control of potential physical applications, was ignored in the previous assessment of semi-conductor systems.

  11. Thermodynamic Perturbation Theory for Solid-Liquid Phase Transition of Lennard-Jones Model

    Institute of Scientific and Technical Information of China (English)

    ZHOUShi-Qi; ZHANGXiao-Qi

    2004-01-01

    Both a free volume approach for Helmholtz free energy and a theoretically-based fitted formula for radial distribution function (rdf) of hard sphere solid are employed to describe the Helmholtz free energy of Lennard-Jones solid in the framework of the first order thermodynamic perturbation theory, which also is employed for the uniform Lennard Jones fluid. The dividing of the Lennard-Jones potential follows from the INCA prescription, but the specification of the equivalent hard sphere diameter is determined by a simple iteration procedure devised originally for liquid state, but extended to solid state in the present study. Two hundred shells are used in the rdf to get an accurate perturbation term.The present approach is very accurate for the description of excess Helmholtz free energy of LJ solid, but shows some deviation from the simulation for excess Helmholtz free energy of uniform LJ fluid when the reduced temperature kT/ε is higher then 5. The present approach is satisfactory for description of solid-liquid phase transition of the Lennard-Jones model.

  12. Thermodynamic Perturbation Theory for Solid-Liquid Phase Transition of Lennard-Jones Model

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shi-Qi; ZHANG Xiao-Qi

    2004-01-01

    Both a free volume approach for Helmholtz free energy and a theoretically-based fitted formula for radial distribution function (rdf) of hard sphere solid are employed to describe the Helmholtz free energy of Lennard-Jones solid in the framework of the first order thermodynamic perturbation theory, which also is employed for the uniform LennardJones fluid. The dividing of the Lennard-Jones potential follows from the WCA prescription, but the specification of the equivalent hard sphere diameter is determined by a simple iteration procedure devised originally for liquid state, but extended to solid state in the present study. Two hundred sheiks are used in the rdf to get an accurate perturbation term.The present approach is very accurate for the description of excess Helmholtz free energy of LJ solid, but shows some deviation from the simulation for excess Helmholtz free energy of uniform LJ fluid when the reduced temperature kT/ε is higher then 5. The present approach is satisfactory for description of solid-liquid phase transition of the Lennard-Jones model.

  13. Solid-phase peptide quantitation assay using labeled monoclonal antibody and glutaraldehyde fixation

    International Nuclear Information System (INIS)

    A solid-phase radioimmunoassay utilizing iodinated peptide-specific monoclonal antibody as a detection system instead of labeled peptide has been developed. Regional specific monoclonal antibodies to either gastrin-releasing peptide or gastrin were used as models to validate the general application of our modified assay. Conditions for radioactive labeling of the monoclonal antibody were determined to minimize oxidant damage, which compromises the sensitivity of other reported peptide quantitation assays. Pretreatment of 96-well polyvinyl chloride test plates with a 5% glutaraldehyde solution resulted in consistent retention of sufficient target peptide on the solid-phase matrix to allow precise quantitation. This quantitative method is completed within 1 h of peptide solid phasing. Pretreatment of assay plates with glutaraldehyde increased binding of target peptide and maximized antibody binding by optimizing antigen presentation. The hypothesis that glutaraldehyde affects both peptide binding to the plate and orientation of the peptide was confirmed by analysis of several peptide analogs. These studies indicate that peptide binding was mediated through a free amino group leaving the carboxy-terminal portion of the target peptide accessible for antibody binding. It was observed that the length of the peptide also affects the amount of monoclonal antibody that will bind. Under the optimal conditions, results from quantitation of gastrin-releasing peptide in relevant samples agree well with those from previously reported techniques. Thus, we report here a modified microplate assay which may be generally applied for the rapid and sensitive quantitation of peptide hormones

  14. Solid phase extraction of uranium (VI) using penicillium chrysogenum immobilized on silica gel

    International Nuclear Information System (INIS)

    Uranium is a metal of strategic importance in the area of Nuclear Technology. It has due to its usage in power generation. Being a toxic element and due to environmental concerns its determination from water, soil and other samples has gained significance. The determination of traces of uranium in such samples requires a preconcentration step. Biosorption methods involving solid phase extraction utilizes various materials of biological origin, including bacteria, fungi, yeast, algae, etc. In the present work a solid phase extraction method for separation and enrichment of uranium (VI) was developed. A solid phase was prepared by immobilization 150 mg of Penicillium and 1.0 g silica. A 350 mg of Penicillium chrysogenum immobilized silica mixed with double distilled water packed in a glass column (150 mm length and 10 mm internal diameter) with wool as support and was systematically investigated to optimize the conditions for quantitative sorption and desorption of uranium (VI). It was determined spectrophotometrically using Arsenazo (III) at 650 nm

  15. Simultaneous solid phase extraction of cobalt, strontium and cesium from liquid radioactive waste using microcrystalline naphthalene

    International Nuclear Information System (INIS)

    Most of the procedures developed for the extraction of cobalt, strontium and cesium by solid phase extraction do not employ simultaneous extraction of them. In this study, rapid simultaneous removal of Co2+, Sr2+ and Cs+ on microcrystalline naphthalene as solid-phase extractant was investigated. These ions were allowed to form chelates with oxine and then adsorbed on freshly microcrystalline naphthalene from aqueous solutions. The solid phase extraction procedure (SPE) was optimized by using model solution containing Co2+, Sr2+ and Cs+ in batch system. The effects of different parameters such as variation in pH, reagent concentration, standing time, naphthalene solution concentration and contact time on the simultaneous removal of these ions was studied. The obtained results indicated that, sorption was found to be rapid, and the percentage removal of Co2+, Sr2+ and Cs+ was found to be 98, 79 and 68% within 10 min, respectively. The kinetics of the sorption process was investigated to understand the kinetic characteristics of sorption of metal chelates onto microcrystalline naphthalene. The developed procedure has been successfully applied to the removal and recovery of 60Co and 134Cs from liquid radioactive waste. The parameters can be used for designing a plant for treatment of wastewater economically.

  16. Studies on solid phase synthesis,characterization and fluorescent property of the new rare earth complexes

    Directory of Open Access Journals (Sweden)

    Jianwei SHI

    2015-04-01

    Full Text Available Rare earth-β-diketone ligand complex luminescent material has stable chemical properties and excellent luminous property. Using europium oxide and (γ-NTA as raw materials, novel rare earth-β-dione complexes are synthesized by solid state coordination chemistry. The synthesis temperature and milling time are discussed for optimization. Experimental results show that the suitable reaction situation is at 50 ℃ and 20 h for solid-phase synthesis. The compositions and structures of the complexes are characterized by means of elemental analysis, UV-Vis and FTIR methods, and the phase stability of the complex is determined by using TG-DTA technique. It is proved that preparation of waterless binary rare earth complexes by the solid phase reaction method results in a higher product yield. The fluorescence spectra show that between Eu (Ⅲ and γ-NTA, there exists efficient energy transfer, and the rare earth complexes synthesis is an excellent red bright light-emitting material with excellent UV excited luminescence properties.

  17. SOLID PHASE MICROEXTRACTION FOR TRACE ANALYSIS OF BENZENE IN ENVIRONMENTAL MONITORING

    Directory of Open Access Journals (Sweden)

    S. J. Shahtaheri, H. R. Heidari, F. Golbabaei, M. Alimohammadi, A. Rahimi Froshani

    2006-07-01

    Full Text Available Conventional analytical method for organic pollutants in water requires extraction of the pollutants, using hazardous solvent. Solid phase microextraction is a solvent free equilibrium extraction method, in which, proper calibration can allow quantitative determinations of organic pollutants at a very good sensitivity without the use of any organic solvent. Because individual volatile organic carbons are generally exposed environmentally and present in urine only at trace levels, a sensitive and accurate determination technique is essential. So, this study describes the optimization of headspace solid phase microextraction (HS-SPME followed by GC-FID for benzene in spiked urine. Through this investigations, the parameters affecting the extraction and gas chromatographic determination of analytes, including extraction time, temperature, desorption temperature, desorption time, salt addition, sample pH, sample volume and sample agitation were studied. An optimized headspace extraction was carried out at 30°C for 6 min in the presence of 0.2 g/mL of NaCl in the sample solution. Desorption of the analytes was carried out for 60 sec. at 250°C. The optimized procedure was also validated with three different pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as six within-day experiments. The accuracy, linearity, detection limits were also determined. The headspace solid phase microextraction, GC-FID technique provides a relatively simple, convenient, practical procedure, which was here successfully applied to determine benzene in spiked urine.

  18. Semiautomated solid-phase extraction manifold with a solvent-level sensor.

    Science.gov (United States)

    Orlando, R M; Rath, S; Rohwedder, J J R

    2013-11-15

    A semiautomated solid-phase extraction manifold for multiple extractions is presented. The manifold utilizes commercial solid-phase syringe cartridges and automatically introduces and elutes all the solvents during the extraction, reducing the typical workload and stress of the analyst. The manifold consists of a peristaltic pump with solenoid valves in a flow circuit that contains transmissive photomicrosensors. The photomicrosensors were used to control the solvent dispenser and the solvent level inside the cartridge. As solvent-level sensors, the photomicrosensors determined the exact time the solvent reached the top frit to avoid sorbent drying and accurately perform the solvent exchange. The repeatability of the manifold to introduce a particular volume of solvent into the cartridges was measured, and the precisions were between 0.05 and 2.89% (RSD). To evaluate the manifold, the amount of two fluoroquinolones in a fortified blank milk sample was determined. The results of the intra- and inter-day precision of multiple extractions from the fortified milk samples resulted in precisions better than 9.0% (RSD) and confirmed that the arrangement of the semiautomated manifold could adequately be used in solid-phase extraction with commercial cartridges. PMID:24148370

  19. Solid-gaseous phase transformation of elemental contaminants during the gasification of biomass.

    Science.gov (United States)

    Jiang, Ying; Ameh, Abiba; Lei, Mei; Duan, Lunbo; Longhurst, Philip

    2016-09-01

    Disposal of plant biomass removed from heavy metal contaminated land via gasification achieves significant volume reduction and can recover energy. However, these biomass often contain high concentrations of heavy metals leading to hot-corrosion of gasification facilities and toxic gaseous emissions. Therefore, it is of significant interest to gain a further understanding of the solid-gas phase transition of metal(loid)s during gasification. Detailed elemental analyses (C, H, O, N and key metal/metalloid elements) were performed on five plant species collected from a contaminated site. Using multi-phase equilibria modelling software (MTDATA), the analytical data allows modelling of the solid/gas transformation of metal(loid)s during gasification. Thermodynamic modelling based on chemical equilibrium calculations was carried out in this study to predict the fate of metal(loid) elements during typical gasification conditions and to show how these are influenced by metal(loid) composition in the biomass and operational conditions. As, Cd, Zn and Pb tend to transform to their gaseous forms at relatively low temperatures (1200°C). Simulation of pressurised gasification conditions shows that higher pressures increase the temperature at which solid-to-gaseous phase transformations takes place. PMID:26603198

  20. Bacterial migration and motion in a fluid phase and near a solid surface

    Energy Technology Data Exchange (ETDEWEB)

    Frymier, P.D. Jr.

    1995-01-01

    An understanding of the migration and motion of bacteria in a fluid phase and near solid surfaces is necessary to characterize processes such as the bioremediation of hazardous waste, the pathogenesis of infection, industrial biofouling and wastewater treatment, among others. This study addresses three questions concerning the prediction of the distribution of a population of bacteria in a fluid phase and the motion of bacteria near a solid surface: Under what conditions does a one-dimensional phenomenological model for the density of a population of chemotactic bacteria yield an adequate representation of the migration of bacteria subject to a one-dimensional attractant gradient? How are the values of transport coefficients obtained from experimental data affected by the use of the one-dimensional phenomenological model and also by the use of different descriptions of bacterial swimming behavior in a mathematically rigorous balance equation? How is the characteristic motion of bacteria swimming in a fluid affected by the presence of a solid phase? A computer simulation that rigorously models the movement of a large population of individual chemotactic bacteria in three dimensions is developed to test the validity of a one-dimensional phenomenological model for bacterial migration in a fluid.

  1. Fragment-based solid-phase assembly of oligonucleotide conjugates with peptide and polyethylene glycol ligands.

    Science.gov (United States)

    Dirin, Mehrdad; Urban, Ernst; Noe, Christian R; Winkler, Johannes

    2016-10-01

    Ligand conjugation to oligonucleotides is an attractive strategy for enhancing the therapeutic potential of antisense and siRNA agents by inferring properties such as improved cellular uptake or better pharmacokinetic properties. Disulfide linkages enable dissociation of ligands and oligonucleotides in reducing environments found in endosomal compartments after cellular uptake. Solution-phase fragment coupling procedures for producing oligonucleotide conjugates are often tedious, produce moderate yields and reaction byproducts are frequently difficult to remove. We have developed an improved method for solid-phase coupling of ligands to oligonucleotides via disulfides directly after solid-phase synthesis. A 2'-thiol introduced using a modified nucleotide building block was orthogonally deprotected on the controlled pore glass solid support with N-butylphosphine. Oligolysine peptides and a short monodisperse ethylene glycol chain were successfully coupled to the deprotected thiol. Cleavage from the resin and full removal of oligonucleotide protection groups were achieved using methanolic ammonia. After standard desalting, and without further purification, homogenous conjugates were obtained as demonstrated by HPLC, gel electrophoresis, and mass spectrometry. The attachment of both amphiphilic and cationic ligands proves the versatility of the conjugation procedure. An antisense oligonucleotide conjugate with hexalysine showed pronounced gene silencing in a cell culture tumor model in the absence of a transfection reagent and the corresponding ethylene glycol conjugate resulted in down regulation of the target gene to nearly 50% after naked application. PMID:27236069

  2. Preparation of fluorescent DNA probe by solid-phase organic synthesis

    Directory of Open Access Journals (Sweden)

    2009-08-01

    Full Text Available Fluorescent DNA probe based on fluorescence resonance energy transfer (FRET was prepared by solid-phase organic synthesis when CdTe quantum dots (QDs were as energy donors and Au nanoparticles (AuNPs were as energy accepters. The poly(divinylbenzene core/poly(4-vinylpyridine shell microspheres, as solid-phase carriers, were prepared by seeds distillation-precipitation polymerization with 2,2′-azobisisobutyronitrile (AIBN as initiator in neat acetonitrile. The CdTe QDs and AuNPs were self-assembled on the surface of core/shell microspheres, and then the linkage of CdTe QDs with oligonucleotides (CdTe-DNA and AuNPs with complementary single-stranded DNA (Au-DNA was on the solid-phase carriers instead of in aqueous solution. The hybridization of complementary double stranded DNA (dsDNA bonded to the QDs and AuNPs (CdTe-dsDNA-Au determined the FRET distance of CdTe QDs and AuNPs. Compared with the fluorescence of CdTe-DNA, the fluorescence of CdTe-dsDNA-Au conjugates (DNA probes decreased extremely, which indicated that the FRET occurred between CdTe QDs and AuNPs. The probe system would have a certain degree recovery of fluorescence when the complementary single stranded DNA was introduced into this system, which showed that the distance between CdTe QDs and AuNPs was increased.

  3. Application of the phase method in radioisotope measurements of the liquid - solid particles flow in the vertical pipeline

    Science.gov (United States)

    Hanus, Robert; Zych, Marcin; Petryka, Leszek; Mosorov, Volodymyr; Hanus, Paweł

    2015-05-01

    The paper presents idea and an application of the gamma-absorption method to a two-phase flow investigation in a vertical pipeline, where the flow of solid particles transported by water was examined by a set of two 241Am radioactive sources and probes with NaI(Tl) scintillation crystals. In the described experiments as solid phase the ceramic models representing natural polymetallic ocean nodules were used. For advanced analysis of electrical signals obtained from detectors the phase of cross-spectral density function has been applied. Results of the average solid-phase velocity measurements were compared with one obtained by application of the classical cross-correlation. It was found that the combined uncertainties of the velocity of solid particles evaluation in the presented experiment did not exceed 0.6% in phase method and 3.2% in cross-correlation method.

  4. Liquid-liquid and liquid-solid phase separation and flocculation for a charged colloidal dispersion

    International Nuclear Information System (INIS)

    We model the intercolloidal interaction by a hard-sphere Yukawa repulsion to which is added the long-range van der Waals attraction. In comparison with the Derjaguin-Landau-Verwey-Overbeek repulsion, the Yukawa repulsion explicitly incorporates the spatial correlations between colloids and small ions. As a result, the repulsive part can be expressed analytically and has a coupling strength depending on the colloidal volume fraction. By use of this two-body potential of mean force and in conjunction with a second-order thermodynamic perturbation theory, we construct the colloidal Helmholtz free energy and use it to calculate the thermodynamic quantities, pressure and chemical potential, needed in the determination of the liquid-liquid and liquid-solid phase diagrams. We examine, in an aqueous charged colloidal dispersion, the effects of the Hamaker constant and particle size on the conformation of a stable liquid-liquid phase transition calculated with respect to the liquid-solid coexistence phases. We find that there exists a threshold Hamaker constant or particle size whose value demarcates the stable liquid-liquid coexistence phases from their metastable counterparts. Applying the same technique and using the energetic criterion, we extend our calculations to study the flocculation phenomenon in aqueous charged colloids. Here, we pay due attention to determining the loci of a stability curve stipulated for a given temperature T0, and obtain the parametric phase diagram of the Hamaker constant vs the coupling strength or, at given surface potential, the particle size. By imposing T0 to be the critical temperature Tc, i.e., setting kBT0 (=kBTc) equal to a reasonable potential barrier, we arrive at the stability curve that marks the irreversible reversible phase transition. The interesting result is that there occurs a minimum size for the colloidal particles below (above) which the colloidal dispersion is driven to an irreversible (reversible) phase transition

  5. A two-phase solid/fluid model for dense granular flows including dilatancy effects

    Science.gov (United States)

    Mangeney, Anne; Bouchut, Francois; Fernandez-Nieto, Enrique; Koné, El-Hadj; Narbona-Reina, Gladys

    2016-04-01

    Describing grain/fluid interaction in debris flows models is still an open and challenging issue with key impact on hazard assessment [{Iverson et al.}, 2010]. We present here a two-phase two-thin-layer model for fluidized debris flows that takes into account dilatancy effects. It describes the velocity of both the solid and the fluid phases, the compression/dilatation of the granular media and its interaction with the pore fluid pressure [{Bouchut et al.}, 2016]. The model is derived from a 3D two-phase model proposed by {Jackson} [2000] based on the 4 equations of mass and momentum conservation within the two phases. This system has 5 unknowns: the solid and fluid velocities, the solid and fluid pressures and the solid volume fraction. As a result, an additional equation inside the mixture is necessary to close the system. Surprisingly, this issue is inadequately accounted for in the models that have been developed on the basis of Jackson's work [{Bouchut et al.}, 2015]. In particular, {Pitman and Le} [2005] replaced this closure simply by imposing an extra boundary condition at the surface of the flow. When making a shallow expansion, this condition can be considered as a closure condition. However, the corresponding model cannot account for a dissipative energy balance. We propose here an approach to correctly deal with the thermodynamics of Jackson's model by closing the mixture equations by a weak compressibility relation following {Roux and Radjai} [1998]. This relation implies that the occurrence of dilation or contraction of the granular material in the model depends on whether the solid volume fraction is respectively higher or lower than a critical value. When dilation occurs, the fluid is sucked into the granular material, the pore pressure decreases and the friction force on the granular phase increases. On the contrary, in the case of contraction, the fluid is expelled from the mixture, the pore pressure increases and the friction force diminishes. To

  6. The phase diagram of solid hydrogen at high pressure: A challenge for first principles calculations

    Science.gov (United States)

    Azadi, Sam; Foulkes, Matthew

    2015-03-01

    We present comprehensive results for the high-pressure phase diagram of solid hydrogen. We focus on the energetically most favorable molecular and atomic crystal structures. To obtain the ground-state static enthalpy and phase diagram, we use semi-local and hybrid density functional theory (DFT) as well as diffusion quantum Monte Carlo (DMC) methods. The closure of the band gap with increasing pressure is investigated utilizing quasi-particle many-body calculations within the GW approximation. The dynamical phase diagram is calculated by adding proton zero-point energies (ZPE) to static enthalpies. Density functional perturbation theory is employed to calculate the proton ZPE and the infra-red and Raman spectra. Our results clearly demonstrate the failure of DFT-based methods to provide an accurate static phase diagram, especially when comparing insulating and metallic phases. Our dynamical phase diagram obtained using fully many-body DMC calculations shows that the molecular-to-atomic phase transition happens at the experimentally accessible pressure of 374 GPa. We claim that going beyond mean-field schemes to obtain derivatives of the total energy and optimize crystal structures at the many-body level is crucial. This work was supported by the UK engineering and physics science research council under Grant EP/I030190/1, and made use of computing facilities provided by HECTOR, and by the Imperial College London high performance computing centre.

  7. Determination of aflatoxins in rice samples by ultrasound-assisted matrix solid-phase dispersion.

    Science.gov (United States)

    Manoochehri, Mahboobeh; Asgharinezhad, Ali Akbar; Safaei, Mahdi

    2015-01-01

    This work describes the application of ultrasound-assisted matrix solid-phase dispersion as an extraction and sample preparation approach for aflatoxins (B1, B2, G1 and G2) and subsequent determination of them by high-performance liquid chromatography-fluorescence detection. A Box-Behnken design in combination with response surface methodology was used to determine the affecting parameters on the extraction procedure. The influence of different variables including type of dispersing phase, sample-to-dispersing phase ratio, type and quantity of clean-up phase, ultrasonication time, ultrasonication temperature, nature and volume of the elution solvent was investigated in the optimization study. C18, primary-secondary amine (PSA) and acetonitrile were selected as dispersing phase, clean-up phase and elution solvent, respectively. The obtained optimized values were sample-to-dispersing phase ratio of 1 : 1, 60 mg of PSA, 11 min ultrasonication time, 30°C ultrasonication temperature and 4 mL acetonitrile. Under the optimal conditions, the limits of detection were ranged from 0.09 to 0.14 ng g(-1) and the precisions [relative standard deviation (RSD%)] were extraction of trace amounts of aflatoxins in rice samples. PMID:24771057

  8. Monitoring of chloropesticide methoxychlor preconcentration from waste water using hplc - solid phase extraction (abstract)

    International Nuclear Information System (INIS)

    The method involves preconcentration of methoxychlor by solid phase extraction (SPE) with 1 mL silica based C-18 and 3 mL polymer based C-18 cartridge and then quantification by high performance liquid chromatography with UV detector (HPLC-UV). Optimization of HPLC parameters was done by determining max of methoxychlor on a double beam UV/Visible spectrophotometer, flow rate of mobile phase on reversed phase columns. Lowest detection limit for methoxychlor dissolved in water and methanol was 0.2ppm and 0.1ppm respectively. For solid phase extraction recovery studies and effect of different parameters such as initial concentration of analyte 0.01 to 0.05 ppm, loading rate 1 and 2mL/min, nature of desorbing solvent (methanol, ethyl acetate and acetonitrile) were investigated. Periodic self degradation of methoxychlor, and reusing potential of both SPE materials was also explored. Lower initial concentrations and slower loading rate of methoxychlor solutions gave improved recoveries. Recoveries were in the range of 80 to 90% for new SPE cartridge and reduced to 35 to 57% for once used silica based C-18 tubes. It was around 73 % for HLB C18 on their second use, and decreased on their repeated reuse. Lastly recoveries for stimulant and real waste water samples were determined to be 77 and 60% respectively. (author)

  9. Solid phase extraction and spectrophotometric determination of palladium with 2-(2-quinolylazo-5-diethylaminobenzoic acid

    Directory of Open Access Journals (Sweden)

    WEIZU YANG

    2006-07-01

    Full Text Available Asensitive, selective and rapid method for the determination of palladium based on the rapid reaction of palladium(II with 2-(2-quinolylazo-5-diethylaminobenzoic acid (QADEAB and the solid phase extraction of the Pd(II –QADEAB chelate with a reversed phase polymer-based C18 cartridge was developed. In the presence of 0.05 – 0. 5 mol/L of hydrochloric acid solution and cetyl trimethylammonium bromide (CTAB medium, QADEAB reacts with palladium(II to form a violet complex with a mole ratio 1:2 (palladium to QADEAB. The chelate was enriched by solid phase extraction with a reversed phase polymer-based C18 cartridge. An enrichment factor of 200 was obtained by elution of the chelate form the cartridge with the minimal amount of isopentyl alcohol. The molar absorptivity of the chelate in the isopentyl alcohol medium was 1.43 × 105 L mol-1 cm-1 at 628 nm. Beer’s law was obeyed in the range of 0.01 – 1.2 mg/mL. The relative standard deviation for eleven replicate samples at the 0.2 mg/L level was 2.18 %. The attained detection limit amounted to 0.02 mg/L in the original samples. This method was applied to the determination of palladium in environmental samples with good results.

  10. Preparation and properties of poly(vinyl alcohol)-g-octadecanol copolymers based solid-solid phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Shi Haifeng, E-mail: haifeng.shi@gmail.com [State Key Laboratory of Hollow Fiber Membrane Materials and Processes, Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, Institute of Functional Fiber, School of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China); Li Jianhua; Jin Yanmei; Yin Yiping [State Key Laboratory of Hollow Fiber Membrane Materials and Processes, Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, Institute of Functional Fiber, School of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China); Zhang Xingxiang, E-mail: zhangpolyu@gmail.com [State Key Laboratory of Hollow Fiber Membrane Materials and Processes, Tianjin Municipal Key Lab of Fiber Modification and Functional Fiber, Institute of Functional Fiber, School of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin 300160 (China)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer In this paper, our objective is just focused on the preparation and characterization of such SSPCMs aiming at providing one suitable material for improving the thermal stability and preventing the liquid leakage from the matrix. Here, the SSPCMs can be fabricated by grafting to method between poly(vinyl alcohol) and octadecanol, which the grafting ratio can be controlled by adjusting the feeding components. Black-Right-Pointing-Pointer The thermal properties, crystalline structure and morphology were detailed studies by WAXD, FT-IR, TGA and DSC, proving that the PVA-g-octadecanol process the better thermal storage ability and thermal stability. Compared with pure octadecanol, the heat fusion of PVA-g-octadecanol decreased due to the mobility confinement and the lower rearrangements of C18 alkyl side chains. Black-Right-Pointing-Pointer This result is for the first time reported, and is a meaningful result for the investigation of the solid-solid phase change materials, and the preparation process provides one template-directed approach to obtain the high-performance materials with the better heat storage and thermal stability. - Abstract: The heat storage and phase transition behavior of a series of poly(vinyl alcohol)-g-octadecanol copolymers (PVA-g-C18OH) with apparent grafting ratios ranging from 283 to 503%, synthesized through 'grafting to' method, has been investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), wide-angle X-ray diffraction (WAXD) and polarized optical microscopy (POM). PVA-g-C18OH copolymers exhibit the better thermal stability against C18OH, and the thermal energy storage ability ({Delta}H{sub m}) is of dependence on the apparent grafting ratios. Compared with C18OH, the lower thermal storage efficiency possible is attributed to the less CH{sub 2} groups entered into the crystalline domains and the frustrated

  11. NMR signal analysis to characterize solid, aqueous, and lipid phases in baked cakes.

    Science.gov (United States)

    Le Grand, F; Cambert, M; Mariette, F

    2007-12-26

    Proton mobility was studied in molecular fractions of some model systems and of cake using a 1H nuclear magnetic resonance (NMR) relaxation technique. For cake, five spin-spin relaxation times (T2) were obtained from transverse relaxation curves: T2 (1) approximately 20 micros, T2 (2) approximately 0.2 ms, T2 (3) approximately 3 ms, T2 (4) approximately 50 ms, and T2 (2) approximately 165 ms. The faster component was attributed to the solid phase, components 2 and 3 were associated with the aqueous phase, and the two slowest components were linked to the lipid phase. After cooking, the crust contained more fat but less water than the center part of the cake. The amount of gelatinized starch was lower in the crust, and water was more mobile due to less interaction with macromolecules. This preliminary study revealed different effects of storage on the center and crust. PMID:18044835

  12. Phase stability of Li-ion conductive, ternary solid polymer electrolytes

    International Nuclear Information System (INIS)

    The chemical–physical properties of a ternary solid polymer electrolyte (SPE) system consisting of poly(ethylene oxide) and two salts, namely lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and the ionic liquid N-methyl-N-butyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI), are reported in this work. The ternary phase diagram shows the composition limits of the thermodynamically stabilized amorphous phase where the polymer electrolyte achieved the maximum conductivity. The important conductivity threshold of 10−3 S cm−1 at 40 °C is exceeded for these compositions. Two reasons for the high conductivity are identified; the decreased overall coordination to the Li+-ion and a Tg as low as −67 °C. Also presented is the thermal stability characterization of such polymer electrolytes. The amorphous phase seems to be thermodynamically unfavored; however, the recrystallization process is slow

  13. Transient state study of electric motor heating and phase change solid-liquid cooling

    Energy Technology Data Exchange (ETDEWEB)

    Bellettre, J.; Sartre, V.; Lallemand, A. [Centre National de la Recherche Scientifique (CNRS), Centre de Thermique de Lyon, Villeurbanne, 69 (France); Biais, F. [AUXILEC, Chatou, 78 (France)

    1997-01-01

    This study reports on modelling of an autosynchronous electric motor stator, operating at transient state. The developed model, of the modal type, includes around 20 nodes. The simulations showed that hot spots are localized on the winding heads and led to the choice of a solid-liquid phase change cooling system. The comparison between simulation and experiment permitted the identification of unknown parameters. The model gives a good accuracy during steady-state and in the rising temperature phase. The modelling of the phase change cooling is realized by the addition of two nodes. The sensitivity analysis to PCM properties shows that the hot spot temperature decreases with increasing conductivities, inertia and latent heat of melting of the PCM and with decreasing melting temperature. Gallium (metal melting at 30{sup o}C) is the best PCM for the cooling of hot spots and P116 paraffin is the best non-metallic PCM. (author)

  14. The use of solid-phase fluorescence spectroscopy in the characterisation of organic matter transformations.

    Science.gov (United States)

    Albrecht, R; Verrecchia, E; Pfeifer, H-R

    2015-03-01

    Given its high sensitivity and non-destructive nature, fluorescence excitation-emission matrix (EEM) spectroscopy is widely used to differentiate changes and transformations of dissolved or water-extracted organic matter (OM) in natural environments. The same technique applied directly on solid samples (solid-phase fluorescence spectroscopy, SPF-EEM) provides accurate results when used with pharmaceutical products or food samples, but only a few studies have considered natural OM. This study reports on the use of SPF-EEM on solid compost samples and emphasises the way the different maturation phases can be distinguished with fluorophores closely resembling those found in dissolved samples. A very good correlation has been found with data from Rock-Eval pyrolysis, nuclear magnetic resonance ((13)C CPMAS NMR), and humic-fulvic acid ratios determined by conventional NaOH-extraction. SPF-EEM appears as a much simpler method than the conventional ones to detect transformations in natural OM samples with low mineral contents. However, direct application to soil samples requires some additional studies. PMID:25618693

  15. Determination of theophylline in serum by molecularly imprinted solid-phase extraction with pulsed elution.

    Science.gov (United States)

    Mullett, W M; Lai, E P

    1998-09-01

    The technique of molecular imprinting is used to produce an extensively cross-linked poly(methacrylic acid-co-ethylene dimethacrylate) material that contains theophylline as a print molecule. After Soxhlet extraction of the theophylline, binding sites are formed in the polymer with complementary size, shape, and positioning of chemical functionalities. The molecularly imprinted polymer's (MIP) high theophylline selectivity, chemical stability, and physically robust nature make it an ideal stationary-phase material in columns for HPLC separation of theophylline from other structurally related drug compounds. Mobile-phase tests confirm that a retention mechanism typical of normal-phase chromatography governs the separation, and selectivity of the MIP column can be controlled by a combination of the mobile phase and the sample solvent. Under optimal conditions, the MIP column functions like a solid-phase sorbent for theophylline extraction. Rapid elution of the bound theophylline can be accomplished in a pulsed format through injection of 20 μL of a solvent that has the proper polarity and protic nature to disrupt the electrostatic interactions and hydrogen bonding between theophylline and binding sites. A concentration detection limit of 120 ng/mL is obtained using direct UV absorption detection at 270 nm, which corresponds to a mass detection limit of 2.4 ng. This new technique, molecularly imprinted solid-phase extraction with pulsed elution (MISPE-PE), permits on-line preconcentration of theophylline from a large volume of dilute sample solution. Using a sample volume of 300 μL, a 40 ng/mL standard solution produces a detectable peak signal. Application of MISPE-PE in serum analysis further demonstrates the high capability of the MIP column to selectively isolate theophylline from other matrix components for fast, accurate determination. PMID:21644709

  16. Erosion predictions of stock pump impellers based on liquid-solid two-phase fluid simulations

    International Nuclear Information System (INIS)

    Stock pumps cost 25 percent of total power consumption in a modern paper mill. Owing to the severe erosion of pump casing and impeller during operation, stock pump often results in efficiency drop and rising power consumption. A favourable prediction of the impeller wearing character can effective guide optimization design of stock pump impeller. Thereby it can reduce impeller wear and extend stock pump performance life. We simulated the three-dimensional unsteady solid-liquid two-phase flow characteristic in the hydraulic channel of a low specific speed stock pump with open and three blades impeller. The standard k- ε turbulent model and the pseudo-fluid model were adopted in simulation. Clearance between covers and impeller is taken into consideration in modelling, and pulp is simplified into mixtures of solid particles and water. The Finnie prediction model is applied to predict impeller erosion character. The simulation results of different solid particle size are compared with practical impeller erosion character, and the effects of solid particle size on impeller erosion character are obtained. Thus, numerical method to simulate impeller erosion characteristics of fibered pulp is investigated

  17. Erosion predictions of stock pump impellers based on liquid-solid two-phase fluid simulations

    Science.gov (United States)

    Xiao, Y. X.; Fang, B.; Zeng, C. J.; Yang, L. B.; Wang, F.; Wang, Z. W.

    2013-12-01

    Stock pumps cost 25 percent of total power consumption in a modern paper mill. Owing to the severe erosion of pump casing and impeller during operation, stock pump often results in efficiency drop and rising power consumption. A favourable prediction of the impeller wearing character can effective guide optimization design of stock pump impeller. Thereby it can reduce impeller wear and extend stock pump performance life. We simulated the three-dimensional unsteady solid-liquid two-phase flow characteristic in the hydraulic channel of a low specific speed stock pump with open and three blades impeller. The standard k- ε turbulent model and the pseudo-fluid model were adopted in simulation. Clearance between covers and impeller is taken into consideration in modelling, and pulp is simplified into mixtures of solid particles and water. The Finnie prediction model is applied to predict impeller erosion character. The simulation results of different solid particle size are compared with practical impeller erosion character, and the effects of solid particle size on impeller erosion character are obtained. Thus, numerical method to simulate impeller erosion characteristics of fibered pulp is investigated.

  18. Structural and magnetic phase transitions in MnTe–MnSe solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ingle, Kapil E.; Efrem D' Sa, J.B.C. [Department of Physics, Goa University, Goa 403 206 (India); Das, A. [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Priolkar, K.R., E-mail: krp@unigoa.ac.in [Department of Physics, Goa University, Goa 403 206 (India)

    2013-12-15

    Neutron diffraction studies as a function of temperature on solid solutions of MnSe and MnTe in the Se rich region are presented. Interestingly as Te is doped in MnSe, the structural transformation to NiAs phase diminishes, both in terms of % fraction of compound as well as in terms of transition temperature. In MnTe{sub 0.3}Se{sub 0.7}, the NaCl to NiAs phase transformation occurs at about 40 K and although it is present at room temperature in MnTe{sub 0.5}Se{sub 0.5}, its volume fraction is only about 10% of the total volume of sample. The magnetic ordering temperature of the cubic phase decreases with increasing Te content while the hexagonal phase orders at the same temperature as in MnSe. Anomalies in thermal evolution of lattice parameters at magnetic ordering as well as structural transition temperatures indicate the presence of magnetostructural coupling in these compounds. - Highlights: • Crystal and magnetic structure of Se rich MnTe{sub x}Se{sub 1−x} have been studied using neutron diffraction. • The sample with x=0.5 is close to room temperature structural phase transition boundary between NaCl type cubic to NiAs type hexagonal phase. • NiAs phase is absent in MnTe{sub 0.3}Se{sub 0.7} at higher temperatures and only appears at temperatures below 40 K. • A unique relationship exists between the lattice parameters of the cubic NaCl and hexagonal NiAs phases which is responsible for the absence of NiAs phase at higher temperatures.

  19. Structural and magnetic phase transitions in MnTe–MnSe solid solutions

    International Nuclear Information System (INIS)

    Neutron diffraction studies as a function of temperature on solid solutions of MnSe and MnTe in the Se rich region are presented. Interestingly as Te is doped in MnSe, the structural transformation to NiAs phase diminishes, both in terms of % fraction of compound as well as in terms of transition temperature. In MnTe0.3Se0.7, the NaCl to NiAs phase transformation occurs at about 40 K and although it is present at room temperature in MnTe0.5Se0.5, its volume fraction is only about 10% of the total volume of sample. The magnetic ordering temperature of the cubic phase decreases with increasing Te content while the hexagonal phase orders at the same temperature as in MnSe. Anomalies in thermal evolution of lattice parameters at magnetic ordering as well as structural transition temperatures indicate the presence of magnetostructural coupling in these compounds. - Highlights: • Crystal and magnetic structure of Se rich MnTexSe1−x have been studied using neutron diffraction. • The sample with x=0.5 is close to room temperature structural phase transition boundary between NaCl type cubic to NiAs type hexagonal phase. • NiAs phase is absent in MnTe0.3Se0.7 at higher temperatures and only appears at temperatures below 40 K. • A unique relationship exists between the lattice parameters of the cubic NaCl and hexagonal NiAs phases which is responsible for the absence of NiAs phase at higher temperatures

  20. Valorization of Calcium Carbonate-Based Solid Wastes for the Treatment of Hydrogen Sulfide from the Gas Phase

    OpenAIRE

    Pham Xuan, Huynh; Pham Minh, Doan; Galera Martinez, Marta; Nzihou, Ange; Sharrock, Patrick

    2015-01-01

    This paper focuses on the valorization of calcium carbonate-based solid wastes for theremoval of hydrogen sulfide from gas phase. Two solid wastes taken from industrial sites for theproduction of sodium carbonate and sodium bicarbonate by the Solvay process® were analyzedby different physico-chemical methods. Calcium carbonate was found as the main component ofboth the solid wastes. Trace amounts of other elements such as Mg, Al, Fe, Si, Cl, Na etc. werealso present in these wastes. These sol...

  1. Determination of Pesticide Residues in Soil by Modified Matrix Solid-Phase Dispersion and Gas Chromatography

    International Nuclear Information System (INIS)

    Modified matrix solid-phase dispersion (MMSPD) and gas chromatography have been developed for quantitative analysis of various classes of pesticides (pirimicarb, metalaxyl, metolachlor, isopropalin and pendimethalin) in soil. MMSPD used Florisil as dispersant and acetone as solvent. Determination was carried out by gas chromatography with nitrogen-phosphorus detection (GC-NPD). The effect of the residence time of pesticides in soil on the recoveries was studied. MMSPD was compared with continuous liquid-solid extraction (LSE). MMSPD had good extraction efficiency and cleanup efficiency and the extract obtained could be directly subjected to GC analysis without further purification. The method gave recoveries ranging from 93% to 100% with relative standard deviations (RSDs) lower than 10%. The limits of detection (LODs) ranged from 0.2 to 2.0 ng g-1

  2. Random phase approximation correlation energy using a compact representation for linear response functions: application to solids

    International Nuclear Information System (INIS)

    A new approach was recently presented to compute correlation energies within the random phase approximation using Lanczos chains and an optimal basis set (Rocca 2014 J. Chem. Phys. 140 18A501). This novel method avoids the explicit calculation of conduction states and represents linear response functions on a compact auxiliary basis set obtained from the diagonalization of an approximate dielectric matrix that contains only the kinetic energy contribution. Here, we extend this formalism, originally implemented for molecular systems, to treat periodic solids. In particular, the approximate dielectric matrix used to build the auxiliary basis set is generalized to avoid unphysical negative gaps, that make the model inefficient. The numerical convergence of the method is discussed and the accuracy is demonstrated considering a set including three covalently bonded (C, Si, and SiC) and three weakly bonded (Ne, Ar, and Kr) solids. (paper)

  3. Solid-phase cloning for high-throughput assembly of single and multiple DNA parts

    DEFF Research Database (Denmark)

    Lundqvist, Magnus; Edfors, Fredrik; Sivertsson, Åsa;

    2015-01-01

    is needed or where multiple inserts are to be assembled. In this approach, the solid support allows for head-to-tail assembly of DNA fragments based on hybridization and polymerase fill-in. The usefulness of head-to-tail SPC was demonstrated by assembly of >150 constructs with up to four DNA parts......We describe solid-phase cloning (SPC) for high-throughput assembly of expression plasmids. Our method allows PCR products to be put directly into a liquid handler for capture and purification using paramagnetic streptavidin beads and conversion into constructs by subsequent cloning reactions. We...... present a robust automated protocol for restriction enzyme based SPC and its performance for the cloning of >60 000 unique human gene fragments into expression vectors. In addition, we report on SPC-based single-strand assembly for applications where exact control of the sequence between fragments...

  4. NMR relaxation and phase transitions in solid methane and deuterated derivatives

    International Nuclear Information System (INIS)

    This thesis describes an investigation of properties of solid methane at high pressure (till 10 kbar) with temperatures ranging from 2 until 100 K. The high inverse moment of inertia of the molecule combined with low ordering potentials gives rise to properties for which quantum effects play an important role: e.g. the transition temperature to a partially ordered phase shows an isotope effect of 35% when CH4 protons are substituted by deuterons. Interpretation of NMR properties of solid methane also show quantum effects. First, a helium cryostat is developed and described and NMR results for CH4, CH2D2 and CD4 are given. The influence of discrete tunnel states on the spin-lattice relaxation is studied theoretically. Application of group theory has simplified the calculations considerably. (G.J.P.)

  5. Solid state synthesis of extra phase-pure Li4Ti5O12 spinel

    Directory of Open Access Journals (Sweden)

    Veljković I.

    2011-01-01

    Full Text Available Extra phase-pure Li4Ti5O12 spinel with particle sizes less than 500 nm was synthesized by solid state reaction of mechanochemicaly activated mixture of nano anatase and Li2CO3 for a very short annealing time, 4 h at 800°C. Structural and microstructural properties, the mechanism of solid state reaction between anatase and Li2CO3 as well as thermal stability of prepared spinel were investigated using XRPD, SEM and TG/DSC analysis. The mechanism of reaction implies decomposition of Li2CO3 below 250ºC, formation of monoclinic Li2TiO3 as intermediate product between 400 and 600°C and its transformation to Li4Ti5O12 between 600-800ºC. The spinel structure is stable up to 1000ºC when it is decomposed due to Li2O evaporation.

  6. A Facile Solid-Phase Route to Renewable Aromatic Chemicals from Biobased Furanics.

    Science.gov (United States)

    Thiyagarajan, Shanmugam; Genuino, Homer C; van der Waal, Jan C; de Jong, Ed; Weckhuysen, Bert M; van Haveren, Jacco; Bruijnincx, Pieter C A; van Es, Daan S

    2016-01-22

    Renewable aromatics can be conveniently synthesized from furanics by introducing an intermediate hydrogenation step in the Diels-Alder (DA) aromatization route, to effectively block retro-DA activity. Aromatization of the hydrogenated DA adducts requires tandem catalysis, using a metal-based dehydrogenation catalyst and solid acid dehydration catalyst in toluene. Herein it is demonstrated that the hydrogenated DA adducts can instead be conveniently converted into renewable aromatics with up to 80% selectivity in a solid-phase reaction with shorter reaction times using only an acidic zeolite, that is, without solvent or dehydrogenation catalyst. Hydrogenated adducts from diene/dienophile combinations of (methylated) furans with maleic anhydride are efficiently converted into renewable aromatics with this new route. The zeolite H-Y was found to perform the best and can be easily reused after calcination. PMID:26684008

  7. Liquid–solid phase transition of hydrogen and deuterium in silica aerogel

    Energy Technology Data Exchange (ETDEWEB)

    Van Cleve, E.; Worsley, M. A.; Kucheyev, S. O., E-mail: kucheyev@llnl.gov [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2014-10-28

    Behavior of hydrogen isotopes confined in disordered low-density nanoporous solids remains essentially unknown. Here, we use relaxation calorimetry to study freezing and melting of H{sub 2} and D{sub 2} in an ∼85%-porous base-catalyzed silica aerogel. We find that liquid–solid transition temperatures of both isotopes inside the aerogel are depressed. The phase transition takes place over a wide temperature range of ∼4 K and non-trivially depends on the liquid filling fraction, reflecting the broad pore size distribution in the aerogel. Undercooling is observed for both H{sub 2} and D{sub 2} confined inside the aerogel monolith. Results for H{sub 2} and D{sub 2} are extrapolated to tritium-containing hydrogens with the quantum law of corresponding states.

  8. Liquid–solid phase transition of hydrogen and deuterium in silica aerogel

    International Nuclear Information System (INIS)

    Behavior of hydrogen isotopes confined in disordered low-density nanoporous solids remains essentially unknown. Here, we use relaxation calorimetry to study freezing and melting of H2 and D2 in an ∼85%-porous base-catalyzed silica aerogel. We find that liquid–solid transition temperatures of both isotopes inside the aerogel are depressed. The phase transition takes place over a wide temperature range of ∼4 K and non-trivially depends on the liquid filling fraction, reflecting the broad pore size distribution in the aerogel. Undercooling is observed for both H2 and D2 confined inside the aerogel monolith. Results for H2 and D2 are extrapolated to tritium-containing hydrogens with the quantum law of corresponding states.

  9. Analysis of ecologically relevant pharmaceuticals in wastewater and surface water using selective solid phase extraction and UPLC/MS/MS

    Science.gov (United States)

    A rapid and sensitive method has been developed for the analysis of 48 human prescription active pharmaceutical ingredients (APIs) and 6 metabolites of interest, utilizing selective solid-phase extraction (SPE) and ultra performance liquid chromatography in combination with tripl...

  10. Determination of amphetamines in hair by integrating sample disruption, clean-up and solid phase derivatization.

    Science.gov (United States)

    Argente-García, A; Moliner-Martínez, Y; Campíns-Falcó, P; Verdú-Andrés, J; Herráez-Hernández, R

    2016-05-20

    The utility of matrix solid phase dispersion (MSPD) for the direct analysis of amphetamines in hair samples has been evaluated, using liquid chromatography (LC) with fluorescence detection and precolumn derivatization. The proposed approach is based on the employment of MSPD for matrix disruption and clean-up, followed by the derivatization of the analytes onto the dispersant-sample blend. The fluorogenic reagent 9-fluorenylmethyl chloroformate (FMOC) has been used for derivatization. Different conditions for MSPD, analyte purification and solid phase derivatization have been tested, using amphetamine (AMP), methamphetamine (MET), ephedrine (EPE) and 3,4-methylenedioxymethamphetamine (MDMA) as model compounds. The results have been compared with those achieved by using ultrasound-assisted alkaline digestion and by MSPD combined with conventional solution derivatization. On the basis of the results obtained, a methodology is proposed for the analysis of amphetamines in hair which integrates sample disruption, clean-up and derivatization using a C18 phase. Improved sensitivity is achieved with respect to that obtained by the alkaline digestion or by the MSPD followed by solution derivatization methods. The method can be used for the quantification of the tested amphetamines within the 2.0-20.0ng/mg concentration interval, with limits of detection (LODs) of 0.25-0.75ng/mg. The methodology is very simple and rapid (the preparation of the sample takes less than 15min). PMID:27108048

  11. Complement fixation by solid phase immune complexes. Reduced capacity in SLE sera

    DEFF Research Database (Denmark)

    Baatrup, G; Jonsson, H; Sjöholm, A;

    1988-01-01

    reacted with human serum. The uptake of C3b, C4b and properdin was measured using biotinylated F(ab)2 antibodies to each of the proteins, avidin alkaline phosphatase, and paranitrophenyl phosphate. Serial samples obtained from 15 patients with systemic lupus erythematosus were investigated. Out of 72 sera......, 24 showed a reduced capacity to support incorporation of C4b into solid phase IC. Thirty-one of the sera showed low C3b binding and 59 of the sera a reduced uptake of properdin. The incorporation into solid phase IC of C3b and C4b as well as of C3b and properdin were closely correlated at high...... disease activity. In general, patients with severe disease manifestations showed low values in the uptake assays. Judging from the results obtained by analysis of serial samples, the uptake of C3b, C4b and properdin, complement mediated solubilization of fluid phase IC and the concentrations of C1q...

  12. Phase transition and transport properties of solid Li2CO3

    International Nuclear Information System (INIS)

    The electrical transport properties such as ac electrical conductivity (σ), dielectric costant (ε) and thermoelectric power (θ) of pure polycrystalline lithium carbonate in the form of pressed pellets are studied in the temperature range 300-940 K. The solid-solid high temperature phase transition is detected at 683 K and the activation energies found in low and high temperature phases are 0.95 eV and 0.74 eV, respectively. The dielectric constant values at room temperature 300 K are obtained as 21 at 100 Hz, 17 at 1 kHz and 13 at 10 kHz. The thermoelectric power is found to be independent of time and pressure of pelletisation, and the heats of transport 4.46eV and 2.05eV found in low and high temperature phases suggested that the pure lithium carbonate is an average ionic conductor as these are much higher than those obtained by electrical conductivity method. (author). 20 refs., 3 figs

  13. Study on the solid-phase sintering of the nano-structured heavy tungsten alloy powder

    International Nuclear Information System (INIS)

    Recently, the high performance W-Ni-Fe-Co heavy tungsten alloy has become as the major core material of armor piercing ammunition. Since the melting temperature of tungsten element is too high to be fabricated by the melting process, that the W-Ni-Fe-Co alloy only can be synthesized by powder metallurgy process. In this study, two compositions of alloy powders, 93W-3Ni-2Fe-2Co and 93W-3.5Ni-1.5Fe-2Co, were selected for investigating their microstructure and mechanical properties after solid-phase sintering. These pre-alloyed powders with crystal cell size about 16 nm were synthesized by mechanical alloying (MA) the mixture of appropriate composition of pure elements in the Spex mill for 8 h. Then, the MA powders were compressed by cold isostatic pressing (CIP) and vacuum sintered at various temperature below 1400 oC for different time. Microstructure characterization of the sintered tungsten heavy alloys was conducted by means of SEM with EDS capability, X-ray diffraction (XRD), and TEM techniques. The result reveals that the microstructure of these sintered alloys was found to consist of the tungsten matrix phase and the Fe-Ni solid solution phase. The hardness of these sintered tungsten heavy alloy presents a trend with increasing sintering temperature and sintering time

  14. Two-phase anaerobic digestion within a solid waste/wastewater integrated management system.

    Science.gov (United States)

    De Gioannis, G; Diaz, L F; Muntoni, A; Pisanu, A

    2008-01-01

    A two-phase, wet anaerobic digestion process was tested at laboratory scale using mechanically pre-treated municipal solid waste (MSW) as the substrate. The proposed process scheme differs from others due to the integration of the MSW and wastewater treatment cycles, which makes it possible to avoid the recirculation of process effluent. The results obtained show that the supplying of facultative biomass, drawn from the wastewater aeration tank, to the solid waste acidogenic reactor allows an improvement of the performance of the first phase of the process which is positively reflected on the second one. The proposed process performed successfully, adopting mesophilic conditions and a relatively short hydraulic retention time in the methanogenic reactor, as well as high values of organic loading rate. Significant VS removal efficiency and biogas production were achieved. Moreover, the methanogenic reactor quickly reached optimal conditions for a stable methanogenic phase. Studies conducted elsewhere also confirm the feasibility of integrating the treatment of the organic fraction of MSW with that of wastewater. PMID:18191559

  15. Application of a sepharose bead immunofluorescence assay and a solid-phase radioimmunoassay to the bovine leukemia virus system

    International Nuclear Information System (INIS)

    Several fluorescence assays with bovine leukemia virus (BLV) conjugated to activated Sepharose 4B were used for the detection of BLV and anti-BLV antibodies. These tests were compared with a solid-phase radioimmunoassay and found to be in the same sensitivity range. Sepharose bead immunofluorescence assay and solid-phase radioimmunoassay can be applied to the diagnosis of BLV infection in cattle. (author)

  16. From Polymer to Small Organic Molecules: A Tight Relationship between Radical Chemistry and Solid-Phase Organic Synthesis

    OpenAIRE

    Danilo Mirizzi; Maurizio Pulici

    2011-01-01

    Since Gomberg’s discovery of radicals as chemical entities, the interest around them has increased through the years. Nowadays, radical chemistry is used in the synthesis of 75% of all polymers, inevitably establishing a close relationship with Solid-Phase Organic Synthesis. More recently, the interest of organic chemists has shifted towards the application of usual “in-solution” radical chemistry to the solid-phase, ranging from the use of supported reagents for radical reactions, to the dev...

  17. [Selective enrichment of iridoid glucosides in Hedyotis diffusa Willd. by tandem solid phase extraction].

    Science.gov (United States)

    Zhang, Feng; Guo, Zhimou; Zhang, Feifang; Xue, Xingya; Liang, Xinmiao

    2009-07-01

    A method for selective enrichment of iridoid glucosides in Hedyotis diffusa Willd. by tandem solid phase extraction (SPE) was developed. Oligo(ethylene glycol) (OEG) is a novel type of separation material made in this laboratory. The differences of the surface chemical structures between OEG material and ODS material resulted in their different retention capabilities for iridoid glucosides. Based on the differences, an OEG-ODS solid phase extraction method was designed for selective enrichment of iridoid glucosides. The water extract (150.28 mg) of Hedyotis diffusa Willd. was precipitated by ethanol, and an aliquot (27.03 mg) of the product from the supernatant solution was loaded onto an OEG cartridge and rinsed by 5 mL water. Then, the rinsing solution was loaded onto an ODS cartridge. After it was washed by 5 mL water and eluted by 5 mL methanol, 4.01 mg final product was obtained from the methanol eluent. All the products were characterized by ultra performance liquid chromatography (UPLC), and 14 representative peaks of iridoid glucosides were found. The enrichment results were proved effective by directly comparing the chromatograms each step. To further characterize the enrichment efficiency, the changes of the peak area of iridoid glucosides were investigated. The results showed that the content of 14 iridoid glucosides in the final product reached 6.10 times its original proportion in water extraction product and their recovery was 50.1% on average. Therefore, the iridoid glucosides can be enriched by the tandem solid phase extraction method from water extracting-ethanol precipitating solution of Hedyotis diffusa Willd. with a good selectivity and an acceptable recovery. The proposed method has the advantages of high enrichment efficiency and simple operation. PMID:19938499

  18. Advanced multi-phase flow CFD model development for solid rocket motor flowfield analysis

    Science.gov (United States)

    Liaw, Paul; Chen, Yen-Sen

    1995-03-01

    A Navier-Stokes code, finite difference Navier-Stokes (FDNS), is used to analyze the complicated internal flowfield of the SRM (solid rocket motor) to explore the impacts due to the effects of chemical reaction, particle dynamics, and slag accumulation on the solid rocket motor (SRM). The particulate multi-phase flowfield with chemical reaction, particle evaporation, combustion, breakup, and agglomeration models are included in present study to obtain a better understanding of the SRM design. Finite rate chemistry model is applied to simulate the chemical reaction effects. Hermsen correlation model is used for the combustion simulation. The evaporation model introduced by Spalding is utilized to include the heat transfer from the particulate phase to the gase phase due to the evaporation of the particles. A correlation of the minimum particle size for breakup expressed in terms of the Al/Al2O3 surface tension and shear force was employed to simulate the breakup of particles. It is assumed that the breakup occurs when the Weber number exceeds 6. A simple L agglomeration model is used to investigate the particle agglomeration. However, due to the large computer memory requirements for the agglomeration model, only 2D cases are tested with the agglomeration model. The VOF (Volume of Fluid) method is employed to simulate the slag buildup in the aft-end cavity of the redesigned solid rocket motor (RSRM). Monte Carlo method is employed to calculate the turbulent dispersion effect of the particles. The flowfield analysis obtained using the FDNS code in the present research with finite rate chemical reaction, particle evaporation, combustion, breakup, agglomeration, and VOG models will provide a design guide for the potential improvement of the SRM including the use of materials and the shape of nozzle geometry such that a better performance of the SRM can be achieved. The simulation of the slag buildup in the aft-end cavity can assist the designer to improve the design of

  19. Advanced Multi-phase Flow CFD Model Development for Solid Rocket Motor Flowfield Analysis

    Science.gov (United States)

    Liaw, Paul; Chen, Yen-Sen

    1995-01-01

    A Navier-Stokes code, finite difference Navier-Stokes (FDNS), is used to analyze the complicated internal flowfield of the SRM (solid rocket motor) to explore the impacts due to the effects of chemical reaction, particle dynamics, and slag accumulation on the solid rocket motor (SRM). The particulate multi-phase flowfield with chemical reaction, particle evaporation, combustion, breakup, and agglomeration models are included in present study to obtain a better understanding of the SRM design. Finite rate chemistry model is applied to simulate the chemical reaction effects. Hermsen correlation model is used for the combustion simulation. The evaporation model introduced by Spalding is utilized to include the heat transfer from the particulate phase to the gase phase due to the evaporation of the particles. A correlation of the minimum particle size for breakup expressed in terms of the Al/Al2O3 surface tension and shear force was employed to simulate the breakup of particles. It is assumed that the breakup occurs when the Weber number exceeds 6. A simple L agglomeration model is used to investigate the particle agglomeration. However, due to the large computer memory requirements for the agglomeration model, only 2D cases are tested with the agglomeration model. The VOF (Volume of Fluid) method is employed to simulate the slag buildup in the aft-end cavity of the redesigned solid rocket motor (RSRM). Monte Carlo method is employed to calculate the turbulent dispersion effect of the particles. The flowfield analysis obtained using the FDNS code in the present research with finite rate chemical reaction, particle evaporation, combustion, breakup, agglomeration, and VOG models will provide a design guide for the potential improvement of the SRM including the use of materials and the shape of nozzle geometry such that a better performance of the SRM can be achieved. The simulation of the slag buildup in the aft-end cavity can assist the designer to improve the design of

  20. Effect of pouring temperature on fractal dimension of primary phase morphology in semi-solid A356 alloy

    Institute of Scientific and Technical Information of China (English)

    LIU Zheng; MAO Wei-min; LIU Xiao-mei

    2009-01-01

    The fractal dimensions of primary phase morphology in semi-solid A356 alloy prepared by low superheat pouring and slightly electromagnetic stirring were calculated, and the effect of pouring temperature on fractal dimension of primary phase morphology in semi-solid A356 alloy was researched. The results indicate that it is feasible to prepare semisolid A356 alloy slurry by low superheat pouring and slightly electromagnetic stirring, and there is an important effect of pouring temperature on the morphology and the grain size of the primary phase in semi-solid A356 alloy, in which the reduction of pouring temperature can obviously improve grain size and shape factor of primary phase in semi-solid A356 alloy under the condition of a certain stirring power. The primary phase morphology of semi-solid A356 alloy prepared by low superheat pouring and slightly electromagnetic stirring can be characterized by fractal dimension, and the primary phase morphology obtained by the different processing parameters has the different fractal dimensions. Solidification of semi-solid alloy is a course of change in fractal dimension.

  1. The EPOS Implementation Phase: building thematic and integrated services for solid Earth sciences

    Science.gov (United States)

    Cocco, Massimo; Epos Consortium, the

    2015-04-01

    The European Plate Observing System (EPOS) has a scientific vision and approach aimed at creating a pan-European infrastructure for Earth sciences to support a safe and sustainable society. To follow this vision, the EPOS mission is integrating a suite of diverse and advanced Research Infrastructures (RIs) in Europe relying on new e-science opportunities to monitor and understand the dynamic and complex Earth system. To this goal, the EPOS Preparatory Phase has designed a long-term plan to facilitate integrated use of data and products as well as access to facilities from mainly distributed existing and new research infrastructures for solid Earth Science. EPOS will enable innovative multidisciplinary research for a better understanding of the Earth's physical processes that control earthquakes, volcanic eruptions, ground instability and tsunami as well as the processes driving tectonics and Earth surface dynamics. Through integration of data, models and facilities EPOS will allow the Earth Science community to make a step change in developing new concepts and tools for key answers to scientific and socio-economic questions concerning geo-hazards and geo-resources as well as Earth sciences applications to the environment and to human welfare. Since its conception EPOS has been built as "a single, Pan-European, sustainable and distributed infrastructure". EPOS is, indeed, the sole infrastructure for solid Earth Science in ESFRI and its pan-European dimension is demonstrated by the participation of 23 countries in its preparatory phase. EPOS is presently moving into its implementation phase further extending its pan-European dimension. The EPOS Implementation Phase project (EPOS IP) builds on the achievements of the successful EPOS preparatory phase project. The EPOS IP objectives are synergetic and coherent with the establishment of the new legal subject (the EPOS-ERIC in Italy). EPOS coordinates the existing and new solid Earth RIs within Europe and builds the

  2. Vacancy-impurity nanoclusters in phase-separated solid mixtures 3He - 4He

    International Nuclear Information System (INIS)

    Vacancies in quantum crystals are delocalized and can be considered as quasiparticles (vacancions) with band-energy structure. The delocalization of a vacancy reduces the energy of the system by a half vacancion bandwidth. However, this requires a good periodical structure around it. As a result a crystalline cluster is created. It is shown that such a cluster in phase-separated 3He - 4He solid solutions with small concentration of 4He consists of 4He impurity atoms (vacancy-impurity cluster), not of host atoms with oriented spins (magnetic vacancy). The clusters created may have different structure in dependence of the vacancion parameters. (author)

  3. Multiresidue determination of pesticides in lanolin using matrix solid-phase dispersion.

    Science.gov (United States)

    Pérez, Andrés; González, Gabriel; González, Joaquín; Heinzen, Horacio

    2010-01-01

    An efficient, fast, and accurate matrix solid-phase dispersion sample cleanup procedure was developed specifically for the determination of pesticide residues in lanolin. The scope of the method for organophosphorus, organochlorine, and pyrethroid insecticides is the same as that of official methods from various pharmacopeias. After lanolin dispersion on C18 bonded silica, pesticides are eluted with acetonitrile saturated with n-hexane. Recoveries ranged from 83 to 118% with RSD values of < 20% for most pesticides listed, in compliance with the requirements of European and U.S. pharmacopeias. PMID:20480919

  4. Peptidyl Molecular Imaging Contrast Agents Using a New Solid Phase Peptide Synthesis Approach

    OpenAIRE

    Yoo, Byunghee; Pagel, Mark D.

    2007-01-01

    A versatile method is disclosed for solid phase peptide synthesis (SPPS) of molecular imaging contrast agents. A DO3A moiety was derivatized to introduce a CBZ-protected amino group and then coupled to a polymeric support. CBZ cleavage with Et2AlCl/thioanisole was optimized for SPPS. Amino acids were then coupled to the aminoDOTA loaded resin using conventional step-wise Fmoc SPPS to create a product with DOTA coupled to the C-terminus of the peptide. In a second study, the DO3A moiety was co...

  5. A Convergent Solid-Phase Synthesis of Actinomycin Analogues - Towards Implementation of Double-Combinatorial Chemistry

    DEFF Research Database (Denmark)

    Tong, Glenn; Nielsen, John

    1996-01-01

    The actinomycin antibiotics bind to nucleic acids via both intercalation and hydrogen bonding. We found this 'double-action attack' mechanism very attractive in our search for a novel class of nucleic acid binders. A highly convergent, solid-phase synthetic strategy has been developed for a class...... with the requirements for combinatorial synthesis and furthermore, the final segment condensation allows, for the first time, double-combinatorial chemistry to be performed where two combinatorial libraries can be reacted with each other. Copyright (C) 1996 Elsevier Science Ltd....

  6. Novel nanoporous sorbent for solid-phase extraction in petroleum fingerprinting

    Science.gov (United States)

    Alayande, S. Oluwagbemiga; Hlengilizwe, Nyoni; Dare, E. Olugbenga; Msagati, Titus A. M.; Akinlabi, A. Kehinde; Aiyedun, P. O.

    2016-04-01

    Sample preparation is crucial in the analysis of petroleum and its derivatives. In this study, developing affordable sorbent for petroleum fingerprinting analysis using polymer waste such expanded polystyrene was explored. The potential of electrospun expanded polystyrene (EPS) as a sorbent for the solid-phase extraction (SPE) technique was investigated, and its efficiency was compared with commercial cartridges such as alumina, silica and alumina/silica hybrid commercial for petroleum fingerprinting analysis. The chromatograms showed that the packed electrospun EPS fibre demonstrated excellent properties for SPE applications relative to the hybrid cartridges.

  7. Synthesis of graphene nanoribbons from amyloid templates by gallium vapor-assisted solid-phase graphitization

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Katsuhisa, E-mail: k.murakami@bk.tsukuba.ac.jp; Dong, Tianchen; Kajiwara, Yuya; Takahashi, Teppei; Fujita, Jun-ichi [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Tsukuba Research Center for Interdisciplinary Materials Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Hiyama, Takaki; Takai, Eisuke; Ohashi, Gai; Shiraki, Kentaro [Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan)

    2014-06-16

    Single- and double-layer graphene nanoribbons (GNRs) with widths of around 10 nm were synthesized directly onto an insulating substrate by solid-phase graphitization using a gallium vapor catalyst and carbon templates made of amyloid fibrils. Subsequent investigation revealed that the crystallinity, conductivity, and carrier mobility were all improved by increasing the temperature of synthesis. The carrier mobility of the GNR synthesized at 1050 °C was 0.83 cm{sup 2}/V s, which is lower than that of mechanically exfoliated graphene. This is considered to be most likely due to electron scattering by the defects and edges of the GNRs.

  8. Synthesis of graphene nanoribbons from amyloid templates by gallium vapor-assisted solid-phase graphitization

    International Nuclear Information System (INIS)

    Single- and double-layer graphene nanoribbons (GNRs) with widths of around 10 nm were synthesized directly onto an insulating substrate by solid-phase graphitization using a gallium vapor catalyst and carbon templates made of amyloid fibrils. Subsequent investigation revealed that the crystallinity, conductivity, and carrier mobility were all improved by increasing the temperature of synthesis. The carrier mobility of the GNR synthesized at 1050 °C was 0.83 cm2/V s, which is lower than that of mechanically exfoliated graphene. This is considered to be most likely due to electron scattering by the defects and edges of the GNRs.

  9. Solid-Phase Immunoassay of Polystyrene-Encapsulated Semiconductor Coreshells for Cardiac Marker Detection

    Directory of Open Access Journals (Sweden)

    Sanghee Kim

    2012-01-01

    Full Text Available A solid-phase immunoassay of polystyrene-encapsulated semiconductor nanoparticles was demonstrated for cardiac troponin I (cTnI detection. CdSe/ZnS coreshells were encapsulated with a carboxyl-functionalized polystyrene nanoparticle to capture the target antibody through a covalent bonding and to eliminate the photoblinking and toxicity of semiconductor luminescent immunosensor. The polystyrene-encapsulated CdSe/ZnS fluorophores on surface-modified glass chip identified cTnI antigens at the level of ~ng/mL. It was an initial demonstration of diagnostic chip for monitoring a cardiovascular disease.

  10. Direct determination of enthalpies of solid phase reactions by immersion method

    International Nuclear Information System (INIS)

    It is not generally possible to measure the enthalpy change corresponding to solid phase reactions using the dynamic differential thermal analysis method because these reactions are usually too slow at the temperature of operation of present equipment. A ballistic differential thermal analysis apparatus has been developed which is based on an immersion-compensation method; it overcomes the difficulties previously encountered. This apparatus has been used after calibration for determining the enthalpies of formation of calcium and cadmium titanates. and also the Wigner energies of BeO, MgO and Al2O3 samples irradiated at variable dose at a temperature of under 100 deg. C. (authors)

  11. Automated solid-phase extraction of herbicides from water for gas chromatographic-mass spectrometric analysis

    Science.gov (United States)

    Meyer, M.T.; Mills, M.S.; Thurman, E.M.

    1993-01-01

    An automated solid-phase extraction (SPE) method was developed for the pre-concentration of chloroacetanilide and triazine herbicides, and two triazine metabolites from 100-ml water samples. Breakthrough experiments for the C18 SPE cartridge show that the two triazine metabolites are not fully retained and that increasing flow-rate decreases their retention. Standard curve r2 values of 0.998-1.000 for each compound were consistently obtained and a quantitation level of 0.05 ??g/l was achieved for each compound tested. More than 10,000 surface and ground water samples have been analyzed by this method.

  12. Recent developments in automatic solid-phase extraction with renewable surfaces exploiting flow-based approaches

    DEFF Research Database (Denmark)

    Miró, Manuel; Hartwell, Supaporn Kradtap; Jakmunee, Jaroon; Grudpan, Kate; Hansen, Elo Harald

    2008-01-01

    Solid-phase extraction (SPE) is the most versatile sample-processing method for removal of interfering species and/or analyte enrichment. Although significant advances have been made over the past two decades in automating the entire analytical protocol involving SPE via flow-injection approaches...... overcoming the above shortcomings, so-called bead-injection (BI) analysis, based on automated renewal of the sorbent material per assay exploiting the various generations of flow-injection analysis. It addresses novel instrumental developments for implementing BI and a number of alternatives for online...

  13. Doping-dependence of solid phase epitaxy in boron implanted amorphous silicon layers

    International Nuclear Information System (INIS)

    The kinetics of dopant-enhanced solid phase epitaxy (SPE) have been measured over temperature range 460-660 deg C in buried a-Si layers doped with boron, at concentrations ranging from 1 to 30 x 1019 cm-3. The dopant-enhanced SPE data has been modelled by an extension of generalised Fermi level shifting model to include degenerate semiconductor statistics on the crystalline Si side of the interface. The quality of the fits provides compelling evidence that the GFLS model gives an accurate picture of the dopant-dependence of SPE

  14. Sequential, solid-phase assay for biotin in physiologic fluids that correlates with expected biotin status

    International Nuclear Information System (INIS)

    Interest in accurate measurement of biotin concentrations in plasma and urine has been stimulated by recent advances in the understanding of biotin-responsive inborn errors of metabolism and by several reports describing acquired biotin deficiency during parenteral alimentation. This paper presents a biotin assay utilizing radiolabeled avidin in a sequential, solid-phase method; the assay has increased sensitivity compared to previous methods (greater than or equal to 10 fmol/tube), correlates with expected trends in biotin concentrations in blood and urine in a rat model of biotin deficiency, and can utilize commercially available radiolabeled avidin

  15. Tritiated water processing using liquid phase catalytic exchange and solid oxide electrolyte cell

    International Nuclear Information System (INIS)

    Liquid phase catalytic exchange (LPCE) is an effective method for enrichment and removal of tritium from tritiated water. Combined electrolysis catalytic exchange (CECE) process is an attractive application of a LPCE column. We proposed a new process that improves the CECE process. Using a solid oxide electrolyte (SOE) cell for electrolysis makes the CECE process more energy efficient and eliminates other disadvantages such as large tritium inventory and extremely slow system response. When the cell is used for recombination, the system becomes even more simple, efficiently, reliable and safe. 21 refs., 9 figs

  16. Interfacial Behavior of Fatty-Acylated Sericin Prepared by Lipase-Catalyzed Solid-Phase Synthesis

    OpenAIRE

    Ogino, Masato; Tanaka, Rie; 服部, 誠; Yoshida, Tadashi; 横手, よし子; 高橋, 幸資

    2006-01-01

    Fatty-acylated sericin {1:0.7 molar ratio of sericin (Mr 18,700) to oleic acid} was prepared by lipase-catalyzed solid-phase synthesis in n-hexane containing oleic acid to endow sericin with interfacial properties. Acylation with oleic acid was confirmed by 1H-NMR. The fatty-acylated sericin exhibited superior emulsifying activity index and emulsion stability in the presence of 0?0.5 M NaCl, in a temperature range of 30?80 °C and pH range of 2?7, as compared with the control sericin. The fatt...

  17. Solid phase electron donors control denitrification in groundwater at agricultural sites

    Science.gov (United States)

    Green, C. T.; Liao, L.; Bekins, B. A.; Bohlke, J. K.

    2011-12-01

    Increased concentrations of nitrate in groundwater caused by agricultural use of chemical and organic fertilizers are a concern because of possible risks to environmental and human health. At many sites, these problems are mitigated by natural attenuation of nitrate as a result of microbially mediated denitrification of nitrate to nitrogen gas. Recent studies have clarified the factors affecting the rates and extents of denitrification in groundwater in agricultural areas. Intensive studies were conducted by the US Geological Survey to study agricultural chemicals in California, Nebraska, Washington, and Maryland using laboratory analyses, field measurements, and flow and transport modeling for monitoring well transects (0.5 to 2.5 km in length) and vertical profiles (0 to 50 m in depth). Groundwater analyses included major ion chemistry, dissolved gases, nitrogen and oxygen stable isotopes, and atmospheric age-tracers. Sediments were analyzed for concentrations of potential electron donors for denitrification, including reduced iron and sulfur, and organic carbon. Geochemical data and mass balance calculations indicated that solid-phase electron donors were an important factor controlling denitrification at these sites. To examine the generality of this result, a mathematical model of vertical flux of water, oxygen, and nitrate was developed and applied at these study sites along with 2 new study sites in Iowa and Mississippi and 8 additional sites from previous studies in Nebraska, Texas, Minnesota, Wisconsin, North Carolina, Maryland (2 sites), and New York. Model results confirmed the importance of solid phase electron donors. The normalized reaction rates on an electron flux basis tended to increase with depth from the shallow oxygen reduction zone to the underlying nitrate reduction zone. The pattern of higher rates at depth is consistent with a reaction rate controlled by solid phase donors that are depleted under oxidizing conditions near the surface and in

  18. Challenges of infrared reflective spectroscopy of solid-phase explosives and chemicals on surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, Mark C.; Suter, Jonathan D.; Bernacki, Bruce E.; Johnson, Timothy J.

    2012-09-01

    Reliable active and passive hyperspectral imaging and detection of explosives and solid-phase chemical residue on surfaces remains a challenge and an active area of research and development. Both methods rely on reference libraries for material identification, but in many cases the reference spectra do not sufficiently resemble those instrumental signals scattered from real-world objects. We describe a physics-based model using the dispersive complex dielectric constant to explain what is often thought of as anomalous behavior of scattered or non-specular signatures encountered in active and passive sensing of explosives or chemicals on surfaces and show modeling and experimental results for RDX.

  19. Solid phase radioimmunoassay for detection of antibodies to extractable nuclear antigens

    Energy Technology Data Exchange (ETDEWEB)

    Whittingham, S. (Walter and Eliza Hall Inst. of Medical Research, Parkville (Australia))

    1983-06-24

    A solid phase radioimmunoassay is described for the detection of autoantibodies to the saline-soluble extractable nuclear antigens, ribonucleoprotein (RNP) and SS-B (or La). This assay depends on enrichment of antigens from a crude, commercially available (Pel Freez, USA) extract of rabbit thymus by absorption to the F(ab)/sub 2/ fraction of specific high titre antibody attached to a microtitre plate. Serum antibody reactive with this antigen is then detected by /sup 125/I-labelled Protein A. The assay is simple and is more sensitive than the gel diffusion assays in general use for detecting such antibodies.

  20. A solid phase radioimmunoassay for detection of antibodies to extractable nuclear antigens

    International Nuclear Information System (INIS)

    A solid phase radioimmunoassay is described for the detection of autoantibodies to the saline-soluble extractable nuclear antigens, ribonucleoprotein (RNP) and SS-B (or La). This assay depends on enrichment of antigens from a crude, commercially available (Pel Freez, USA) extract of rabbit thymus by absorption to the F(ab)2 fraction of specific high titre antibody attached to a microtitre plate. Serum antibody reactive with this antigen is then detected by 125I-labelled Protein A. The assay is simple and is more sensitive than the gel diffusion assays in general use for detecting such antibodies. (Auth.)

  1. Preparation of A New Fiber by Sol-gel Technology in Solid-phase Microextraction (SPME)

    Institute of Scientific and Technical Information of China (English)

    Li Ming WEI; Qing Yu OU; Ju Bai LI

    2004-01-01

    The sol-gel technology is applied for the preparation of solid-phase microextraction (SPME) fiber. The fiber demonstrates high thermal stability, efficient extraction rate and the selectivity for non-polar or low-polar analytes. Efficient SPME-GC-FID analyses of benzene- toluene-ethylbenzene-xylenes (BTEXs) and low-polar halocarbon were achieved by the sol-gel coated DSDA-DDBT-TiO2 fiber. Some parameters of the SPME fiber for the determination of halocarbon in aqueous sample were investigated.

  2. Solid-phase radioimmunoassay for the detection of antibodies to collagens

    International Nuclear Information System (INIS)

    A solid-phase radioimmunoassay using 125I-protein A is described for the detection of antibodies to collagens of different types. The optimal conditions for the adsorption of collagen onto polystyrene microplates, then the incubations with the antiserum and finally with the 125I-protein A have been evaluated. The technique was applied successfully to antisera raised in rabbit, goat, guinea pig and mouse against human type I, II, III, IV, V and bovine type I, II, 1α2α3α, X1-X7 collagens

  3. Role of the Surface in Solid-Solid Phase Transitions: Molecular Dynamics Study of the α-γ Transition in Fe

    Science.gov (United States)

    Wang, Binjun; Urbassek, Herbert M.

    2016-05-01

    Using classical molecular dynamics simulation, we study the role of surfaces on solid-solid phase transformations. We contrast the transformation behavior of a thin film (two free surfaces) with a bulk system and with a system containing only one free surface. We focus on bcc Fe and induce the transformation from the bcc to the fcc phase by applying biaxial strain. We find that the critical strain at which the material transforms is independent of whether the system has a free surface or not. However, the nucleation mechanism of the new phase and also the transformation speed are strongly influenced by the existence of surfaces. While bulk systems fail early (after phase transformation to a polycrystal) under the applied load, systems with a free surface show a considerably higher ductility.

  4. Manipulation and visualization of two-dimensional phase distribution of vibrational wave functions in solid parahydrogen crystal

    Science.gov (United States)

    Katsuki, Hiroyuki; Ohmori, Kenzo; Horie, Toru; Yanagi, Hisao; Ohmori, Kenji

    2015-09-01

    Solid parahydrogen, which is known to have an exceptionally long vibrational coherence lifetime as a molecular solid, offers an ideal testbed to perform coherent control experiments in the condensed phase. Here we demonstrate the spatial manipulation and visualization of the relative phase of vibrational wave functions in solid parahydrogen. Spatial distribution of vibrational excitation is generated by femtosecond impulsive Raman excitation. It is shown that the imprinted initial phase can be manipulated by wave-front modulation of the excitation laser pulses with a spatial light modulator. An interferometric measurement is used to convert the spatial phase distribution of the vibrational wave functions to the amplitude distribution. We have confirmed that the spatial profile of the scattered anti-Stokes pulse reveals the spatial phase distribution of the wave functions. The read-and-write scheme demonstrated in this experiment is applicable to a broad range of Raman memory systems accessible by Λ -type transitions.

  5. SOLVENT-FREE SOLID SUPPORTED AND PHASE TRANSFERRED CATALYZED SYNTHESIS OF BENZANILINE DERIVATIVES USING MICROWAVE IRRADIATION

    Directory of Open Access Journals (Sweden)

    Kadir Ozden Yerdelen

    2012-01-01

    Full Text Available In this study, solvent-free and phase transfer catalysis conditions coupled with microwave irradiation and their advantages in synthesis of N-alkylation of primary anilines were reported. In this way two different microwave processing techniques were compared in terms of reaction yields. Consequently, microwave irradiation significantly reduced reaction times compared to traditional heating methods. Particularly synthesis by solvent-free solid supported microwave irradiaton was found more eco-friendly and had higher reaction efficiency against to phase transfer catalysis condition. Organic reactions under solvent-free conditions is advantageous because of enhanced selectivity, efficiency and more importantly, toxic and volatile solvents are avoided. So that this eco-friendly green approach might be applied to the rapid assembly of various alkylation reactions.

  6. Mechanical Yield in Amorphous Solids: A First-Order Phase Transition

    Science.gov (United States)

    Jaiswal, Prabhat K.; Procaccia, Itamar; Rainone, Corrado; Singh, Murari

    2016-02-01

    Amorphous solids yield at a critical value of the strain (in strain-controlled experiments); for larger strains, the average stress can no longer increase—the system displays an elastoplastic steady state. A long-standing riddle in the materials community is what the difference is between the microscopic states of the material before and after yield. Explanations in the literature are material specific, but the universality of the phenomenon begs a universal answer. We argue here that there is no fundamental difference in the states of matter before and after yield, but the yield is a bona fide first-order phase transition between a highly restricted set of possible configurations residing in a small region of phase space to a vastly rich set of configurations which include many marginally stable ones. To show this, we employ an order parameter of universal applicability, independent of the microscopic interactions, that is successful in quantifying the transition in an unambiguous manner.

  7. Problems of Solid-Phase Synthesis in Cylindrical Ampoules under Explosive Loading

    Science.gov (United States)

    Zelepugin, S. A.; Ivanova, O. V.; Yunoshev, A. S.; Zelepugin, A. S.

    2016-04-01

    The peculiarities of solid-phase synthesis are studied experimentally and numerically in the aluminum-fluoroplastic and aluminum-sulfur mixtures in cylindrical ampoules under explosive loading. The experimental results show that the use of a mixture capable of ultrafast exothermic reactions leads to the destruction of a cylindrical ampoule under explosive loading. When the transient shock wave is reflected from the bottom lid of the ampoule as a compression wave, there is a sharp increase in pressure in the lower part of the ampoule, which is accompanied by the increase in rate of the chemical reaction. The high rate of heat release during the chemical reaction in the lower part of the ampoule causes the formation of a gas phase, which leads to a further increase in pressure and destruction of the ampoule.

  8. "Reagentless" flow injection determination of ammonia and urea using membrane separation and solid phase basification

    Science.gov (United States)

    Akse, J. R.; Thompson, J. O.; Sauer, R. L.; Atwater, J. E.

    1998-01-01

    Flow injection analysis instrumentation and methodology for the determination of ammonia and ammonium ions in an aqueous solution are described. Using in-line solid phase basification beds containing crystalline media. the speciation of ammoniacal nitrogen is shifted toward the un-ionized form. which diffuses in the gas phase across a hydrophobic microporous hollow fiber membrane into a pure-water-containing analytical stream. The two streams flow in a countercurrent configuration on opposite sides of the membrane. The neutral pH of the analytical stream promotes the formation of ammonium cations, which are detected using specific conductance. The methodology provides a lower limit of detection of 10 microgram/L and a dynamic concentration range spanning three orders of magnitude using a 315-microliters sample injection volume. Using immobilized urease to enzymatically promote the hydrolysis of urea to produce ammonia and carbon dioxide, the technique has been extended to the determination of urea.

  9. Isolation of tetracyclines in milk using a solid-phase extracting column and water eluent.

    Science.gov (United States)

    Furusawa, Naoto

    2003-01-01

    An isolating method using a solid-phase extraction (SPE) ISOLUTE(R) C8 endcapped syringe-column for routine monitoring of residual tetracyclines (TCs) (oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), and doxycycline (DC)) in cow's milk is presented. In the simplest and most environmentally harmless method, milk samples could be applied directly to the SPE column, following which all TCs were eluted with water. No organic solvents were used at all. The purified sample was injected into a high-performance liquid chromatography (HPLC) with a photo-diode array detector (PDAD). For the HPLC determination/identification, a LiChrospher(R) 100 RP-8 endcapped column and a mobile phase of acetonitrile -7% (v v(-1)) acetic acid solution (in water) (35:65, v v(-1)) with a PDAD was used. The total time required for the analysis of one sample was 80 and <5%, respectively. PMID:18968895

  10. A novel hybrid metal-organic framework-polymeric monolith for solid-phase microextraction.

    Science.gov (United States)

    Lin, Chen-Lan; Lirio, Stephen; Chen, Ya-Ting; Lin, Chia-Her; Huang, Hsi-Ya

    2014-03-17

    This study describes the fabrication of a novel hybrid metal-organic framework- organic polymer (MOF-polymer) for use as a stationary phase in fritless solid-phase microextraction (SPME) for validating analytical methods. The MOF-polymer was prepared by using ethylene dimethacrylate (EDMA), butyl methacrylate (BMA), and an imidazolium-based ionic liquid as porogenic solvent followed by microwave-assisted polymerization with the addition of 25 % MOF. This novel hybrid MOF-polymer was used to extract penicillin (penicillin G, penicillin V, oxacillin, cloxacillin, nafcillin, dicloxacillin) under different conditions. Quantitative analysis of the extracted penicillin samples using the MOF-organic polymer for SPME was conducted by using capillary electrochromatography (CEC) coupled with UV analysis. The penicillin recovery was 63-96.2 % with high reproducibility, sensitivity, and reusability. The extraction time with the proposed fabricated SPME was only 34 min. PMID:24615770

  11. Kinetics of liquid-solid phase transition in large nickel clusters

    CERN Document Server

    Yakubovich, Alexander V; Schramm, Stefan; Solov'yov, Andrey V

    2012-01-01

    In this paper we have explored computationally the solidification process of large nickel clusters. This process has the characteristic features of the first order phase transition occurring in a finite system. The focus of our research is placed on the elucidation of correlated dynamics of a large ensemble of particles in the course of the nanoscale liquid-solid phase transition through the computation and analysis of the results of molecular dynamics (MD) simulations with the corresponding theoretical model. This problem is of significant interest and importance, because the controlled dynamics of systems on the nanoscale is one of the central topics in the development of modern nanotechnologies. MD simulations in large molecular systems are rather computer power demanding. Therefore, in order to advance with MD simulations we have used modern computational methods based on the graphics processing units (GPU). The advantages of the use of GPUs for MD simulations in comparison with the CPUs are demonstrated ...

  12. Determination of metrafenone in vegetables by matrix solid-phase dispersion and HPLC-UV method.

    Science.gov (United States)

    Li, Jianjun; Li, Yangyang; Xu, Dongliang; Zhang, Jingyu; Wang, Yuxi; Luo, Chao

    2017-01-01

    A simple method for determination of metrafenone in vegetables by matrix solid-phase dispersion (MSPD) and HPLC was developed. All vegetable samples were extracted with dichloromethane, and then the extracts were directly separated on a reversed-phase column with isocratic elution without a cleanup step. The linearity of metrafenone was good with the concentration between 0.005 and 5mg/kg, and the limit of detection (LOD) of the metrafenone was 0.002mg/kg. The recoveries ranged from 86.5% to 104.8% with the relative standard deviations (RSDs) in the range of 2.1-7.9% (n=6). The results indicated that the method was simple, rapid, highly sensitive and suitable for the determination of metrafenone in vegetables. PMID:27507450

  13. Transient photocurrent in poly(3-octadecylthiophene) near the solid-liquid phase transition

    International Nuclear Information System (INIS)

    Poly(3-alkylthiophene)s (PATs) are conducting polymers possessing high processabilities such as solubility and fusibility. Most conducting polymers known to be p-type, or hole transporting semiconductors. PATs are also known as p-type semiconductors in the solid state. Previous studies have suggested that the dominant photocarrier inverts from positive to negative in the liquid state in PAT with relatively long alkyl side chain. In this study, we tried to confirm the sign inversion of the photocarrier in regiorandom poly(3-octadecylthiophene) (PAT18) by means of the time-of-flight method. It was found that the hole mobility decreases with increasing temperature. At the temperature near the solid-liquid phase transition, the hole mobility decreases drastically, and eventually the melting temperature, it was impossible to evaluate the hole mobility from noisy transient photocurrent. On the other hand, transient photocurrents based on electron transport are observed above the melting point. The negative carrier mobility was evaluated in the range from 10-6 to 10-5 cm2/V s, which is comparably the hole mobility at solid state. This fact suggests that the same mechanism, for example interchain hopping limits carrier transport, and the negative carrier is electron. This unique phenomenon is interpreted as modulation of electronic energy state caused by conformational change of the main chain

  14. Reactive magnesium oxide cements: geochemical modelling of pH profile and solid phase composition

    International Nuclear Information System (INIS)

    Due to a range of technical and sustainability advantages, reactive magnesium oxide cements (MgO) are a potential alternative to Portland cement (PC) for conditioning intermediate level radioactive waste (ILW). MgO cements consist of a mixture of hydraulic cement and reactive magnesium oxide to which pozzolans such as silica fume (SF) may be added. While favourable, the mechanical and chemical properties of MgO matrices still require further investigation to ensure effective immobilisation of contaminants. In this study a solubility-speciation model was developed using PHREEQC to simulate blends based on low and high contents of MgO, including SF as a supplementary material. Analyses aimed at characterising binding systems focusing on their equilibrium pH with pure water and saturation index (SI) of solid phases. The geochemical model successfully confirmed that the equilibrium pH is inversely proportional to the fraction of MgO and SF present in the hydrated paste. Comparison with data available on literature mostly gave a consistent picture and the model provided reasonable predictions of existent solid phases. (authors)

  15. A solid-phase radioimmunoassay of serum dehydroepiandrosterone sulphate using a monoclonal antibody

    International Nuclear Information System (INIS)

    A monoclonal antibody directed against dehydroepiandrosterone, but with high affinity for dehydroepiandrosterone sulphate (DHA-S), has been used to develop a solid phase radioimmunoassay for measuring serum DHA-S. The antibody was covalently linked to polyacrylamide microbeads with no change in binding characteristics. The procedure requires only the chromatography of serum on anion-exchange cellulose before assaying the equivalent of 0.25 μl serum. The method is precise, accurate and specific and can detect 19.5 pg of DHA-S. Serum DHA-S levels measured by this method were in good agreement with those found in a validated radioimmunoassay method involving hydrolysis. The method is quick and one operator could assay 50 blood specimens per day. DHA-S levels in serum from 50 men and 86 women were in agreement with those in the literature. With the availability of theoretically limitless quantities of consistently high quality monoclonal antibodies the advantages of developing solid phase radioimmunoassays for steroids is discussed. (author)

  16. Quantitative separation of aliphatic and aromatic hydrocarbons using silver ion--silica solid-phase extraction

    Science.gov (United States)

    Bennett; Larter

    2000-03-01

    A solid-phase extraction (SPE) method employing silver nitrate impregnated silica has been developed and evaluated for the separation of defined aliphatic and aromatic hydrocarbons from crude oils. The versatility of the SPE method is demonstrated using a light crude oil from the North Sea and a heavy crude oil from Orcutt field (Monterey, California, U.S.A.). The coefficients of variation for a number of geochemical parameters measured on both aliphatic and aromatic hydrocarbons were excellent. The separation efficiency of SPE is demonstrated using quantification of monoaromatic steroid hydrocarbons which are notoriously difficult to efficiently sequester into the aromatic hydrocarbon fraction using traditional liquid chromatographic procedure. The selectivity and efficiency of the SPE technique is comparable with that of silica gel TLC. However, losses of volatile compounds such as naphthalene are limited during SPE since the sample remains in solvent. We conclude that solid-phase extraction affords rapid sample turnover suitable for processing large sample numbers with high reproducibility. PMID:10739209

  17. Isolation of genomic DNA using magnetic nanoparticles as a solid-phase support

    International Nuclear Information System (INIS)

    In recent years, techniques employing magnetizable solid-phase supports (MSPS) have found application in numerous biological fields. This magnetic separation procedure offers several advantages in terms of subjecting the analyte to very little mechanical stress compared to other methods. Secondly, these methods are non-laborious, cheap, and often highly scalable. The current paper details a genomic DNA isolation method optimized in our laboratory using magnetic nanoparticles as a solid-phase support. The quality and yields of the isolated DNA from all the samples using magnetic nanoparticles were higher or equivalent to the traditional DNA extraction procedures. Additionally, the magnetic method takes less than 15 min to extract polymerase chain reaction (PCR) ready genomic DNA as against several hours taken by traditional phenol-chloroform extraction protocols. Moreover, the isolated DNA was found to be compatible in PCR amplification and restriction endonuclease digestion. The developed procedure is quick, inexpensive, robust, and it does not require the use of organic solvents or sophisticated instruments, which makes it more amenable to automation and miniaturization

  18. Selective fiber used for headspace solid-phase microextraction of abused drugs in human urine

    Directory of Open Access Journals (Sweden)

    Sunanta Wangkarn

    2007-09-01

    Full Text Available A sensitive and selective fiber for simultaneous analysis of three drugs of abuse (amphetamine, methamphetamine and ephedrine in urine samples was explored using headspace solid phase microextraction and gas chromatography with flame ionization detection. Several parameters affecting extraction such as extraction time, extraction temperature, pH of solution and salt concentrations were investigated. Among five commercially available fibers, divinylbenzene/carboxen/ polydimethylsiloxane is the most sensitive and selective fiber at pH 10.0, extraction temperature at 80 C for 20 min and desorption temperature at 220 C for 2 min. Under the optimal conditions, the proposed solid phase microextraction method provided good linearity in the ranges 0.1-10 µg/ml for amphetamine and methamphetamine and 0.5-20 µg/ml for ephedrine. The detection limits for amphetamine, methamphetamine and ephedrine were 9, 3 and 30 ng/ml, respectively. The recoveries of three drugs in urine samples were exceeding 85%.

  19. Monitoring the postpartum ovarian activity of Luxi cattle by use of plasma progesterone solid phase RIA

    International Nuclear Information System (INIS)

    The blood samples were collected from 22 Luxi cattle, aged 2.5-8 years, from calving day (day 0) to 80 days postpartum at 4-day interval. Progesterone (P4) levels in plasma were determined by solid phase RIA. The results are summarized as follows: P4 levels in plasma of the cows remained at 0.34 +- 0.04-0.55 +- 0.06 ng/ml before 10.6 +- 3.9-13.6 +- 4.4 days postpartum, then they began to rise and the ovarian activity appeared. The plasma P4 profiles of the cows can be classified into 4 types, characterized by (I) 3 normal cycles; (II) a short cycle followed by 2 normal cycles; (III) a normal cycle followed by a short cycle and a normal cycle; and (IV) some irregular cycles respectively. The lowest and the highest P4 levels were 0.45 +- 0.15-0.60 +- 0.38 and 2.65 +- 1.95-4.17 +- 2.35 ng/ml respectively in luteal cycles. It is also concluded that determining plasma P4 concentrations at 4-day interval can precisely identify the oestrus cycles of cows, and that the solid phase P4-RIA have practical value for determination of plasma P4 concentration

  20. Molecularly imprinted polymer microspheres for solid-phase extraction of protocatechuic acid in Rhizoma homalomenae.

    Science.gov (United States)

    Chen, Fang-Fang; Wang, Guo-Ying; Shi, Yan-Ping

    2011-10-01

    Molecularly imprinted polymers (MIPs) had been prepared by precipitation polymerization method using acrylamide as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, acetonitrile as the porogen solvent and protocatechuic acid (PA), one of phenolic acids, as the template molecule. The MIPs were characterized by scanning electron microscopy and Fourier transform infrared, and their performance relative to non-imprinted polymers was assessed by equilibrium binding experiments. Six structurally similar phenolic acids, including p-hydroxybenzoic acid, gallic acid, salicylic acid, syringic acid, vanillic acid, ferulic acid were selected to assess the selectivity and recognition capability of the MIPs. The MIPs were applied to extract PA from the traditional Chinese medicines as a solid-phase extraction sorbent. The resultant cartridge showed that the MIPs have a good extraction performance and were able to selectively extract almost 82% of PA from the extract of Rhizoma homalomenae. Thus, the proposed molecularly imprinted-solid phase extraction-high performance liquid chromatography method can be successfully used to extract and analyse PA in traditional Chinese medicines. PMID:21809445

  1. Magneto-optical spectroscopic studies of solid and solution-phase tetra-phenyl porphyrin

    Science.gov (United States)

    Wahlen-Strothman, Jacob; Pan, Zhen Wen; Lamarche, Cody; Manning, Lane; Rawat, Naveen; Tokumoto, Takahisa; McGill, Stephen; Furis, Madalina; Chu, Kelvin

    2012-02-01

    Tetraphenylporphyrin (TPP) is a heterocyclic model system for porphyrins found in heme proteins, cytochromes and photosynthetic cofactors. TPP can accommodate a metal ion in the center; D-shell ion porphyrin complexes with a crystalline solid phase are of interest for magnetic studies because of the possibility of macroscopic long-range magnetic order of the ion spins. We have investigated the 5K magnetic properties of poly-crystalline thin films of TPP complexed with Zn, Mn and Cu and deposited through a room temperature capillary pen technique that produces grain size in the 100 micron to 1mm range. Our novel setup measures the UV/VIS, linear dichroism and MCD simultaneously and incorporates a photoelastic modulator and a microscopy superconducting magnet for high-field (5T) measurements. In addition, we present 25T data on samples from the new split magnet at NHMFL. We present solution and crystalline data on metal-complexed TPP; data are analyzed in terms of A and B-type MCD using a perimeter model. We find good agreement with previous solution data, and novel crystalline phase spectra that are correlated to the long range ordering of the solid state.

  2. Development of andrographolide molecularly imprinted polymer for solid-phase extraction

    Science.gov (United States)

    Yin, Xiaoying; Liu, Qingshan; Jiang, Yifan; Luo, Yongming

    2011-06-01

    A method employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) to pretreat samples was developed. The polymers were prepared by precipitation polymerization with andrographolide as template molecule. The structure of MIP was characterized and its static adsorption capacity was measured by the Scatchard equation. In comparison with C 18-SPE and non-imprinted polymer (NIP) SPE column, MIP-SPE column displays high selectivity and good affinity for andrographolide and dehydroandrographolide for extract of herb Andrographis paniculata ( Burm.f.) Nees (APN). MIP-SPE column capacity was 11.9 ± 0.6 μmol/g and 12.1 ± 0.5 μmol/g for andrographolide and dehydroandrographolide, respectively and was 2-3 times higher than that of other two columns. The precision and accuracy of the method developed were satisfactory with recoveries between 96.4% and 103.8% (RSD 3.1-4.3%, n = 5) and 96.0% and 104.2% (RSD 2.9-3.7%, n = 5) for andrographolide and dehydroandrographolide, respectively. Various real samples were employed to confirm the feasibility of method. This developed method demonstrates the potential of molecularly imprinted solid phase extraction for rapid, selective, and effective sample pretreatment.

  3. Determination of cyproheptadine in feeds using molecularly imprinted solid-phase extraction coupled with HPLC.

    Science.gov (United States)

    Yang, Jianwen; Wang, Zongnan; Zhou, Tong; Song, Xuqin; Liu, Qingyong; Zhang, Yuman; He, Limin

    2015-05-15

    A novel method was developed for the determination of cyproheptadine in feeds using molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography. The polymers were prepared using cyproheptadine as a template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linking agent, and dichloromethane as a solvent by bulk polymerization. Under the optimum solid-phase extraction conditions, the molecular imprinting cartridge can selectively extract and enrich cyproheptadine from a variety of feeds. Mean recoveries of cyproheptadine from four kinds of feeds spiked at 0.1, 1.0 and 10mgkg(-1) ranged from 85.5% to 96.2%, with intra-day and inter-day relative standard deviation less than 10%. The calibration curve of cyproheptadine was good linear relationship (r>0.9993) within the range of 0.1-50μgmL(-1). The limit of detection (LOD) and the limit of quantification (LOQ) were 0.04 and 0.1mgkg(-1), respectively. PMID:25855316

  4. The Conformation of Pentanoates in the Solid and in the Gas Phase

    Science.gov (United States)

    Merkens, Carina; Stadtmüller, Tom; Englert, Ulli; Mouhib, Halima; Stahl, Wolfgang

    2014-07-01

    Suitable derivatives of the four isomeric pentanoates have been structurally characterized in the solid and the gas phase. For the latter, the volatile ethyl esters of valeric, isovaleric, methylbutyric, and pivalic acid were investigated by a combination of molecular beam Fourier transform microwave (MB-FTMW) spectroscopy and theoretical calculations. Crystalline salts rather than esters were formed by reaction between the carboxylic acids and trans-1,2-diaminocyclohexane. For both gaseous and crystalline methylbutyrates, an essentially perpendicular arrangement of carboxylate and methyl group was observed; earlier structure determinations documented in the data base agree with this result. Two competing conformers of favourable energy were relevant for the corresponding isovalerates: They were associated with torsion angles around 20° and 50° between the carboxylate and the alkyl chain. Good agreements in conformation have also been achieved for our experimentally observed unbranched valerate derivatives and fully branched pivalates in solid and gas phase. Despite the apparent simplicity of the pentanoates, the identification of their lowest energy conformers represents a challenge for different methods and levels of theory.

  5. Development and evaluation of a magnetic solid-phase radioimmunoassay for total human thyroxine (T4)

    International Nuclear Information System (INIS)

    In this study a simple and rapid magnetic solid-phase radioimmunoassay (RIA) for human thyroxine (T4) was developed using locally raised sheep thyroxine antibody and radioiodinated thyroxine (T4) tracer by chloramine-T method. The assay involves two hours incubation at ambient temperature rang (30 to 35 oC) associated with the antibody covalently linked by the easily performed carbonyldiimidazole (CDI) method to magnetic particles obtained from SIPAC. 0.1% triton with sodium azide used as a wash buffer. L-Thyroxine Na-salt peta hydrate from sigma was used for the preparation of standards and quality control sera. The coupled magnetic anti-T4 solid phase titrated in order to find out the suitable antibody concentration (titre) to be used in the assay. Optimizations followed by validation procedures were done. When correlated with kits imported from NETRIA and AMERSHAM, results were found to be highly comparable r=0.965 and p<0.05. Shelf life was also studied, so that the local prepared T4 RIA magnetic reagents can be used for the measurement of total human thyroxine with a very low cost compared to imported kits. (Author)

  6. Electromagnetic properties of high-carbon ferrochrome powders decarburized in solid phase by microwave heating

    International Nuclear Information System (INIS)

    Highlights: • High-carbon ferrochrome powders present diamagnetism. • We study the effect of temperature and time on electromagnetic properties. • The relative permittivity and permeability exhibit an opposite change trend. • The absorption peak shifts to lower frequency with the increasing temperature. - Abstract: During solid-phase decarburization, the changes of the electromagnetic properties can reflect the variation degree of material components. High-carbon ferrochrome powders (HCFCP) with addition of CaCO3 were decarburized in solid phase by microwave heating and the electromagnetic properties of the decarburized materials were investigated. With increasing in heating temperature from 1173 to 1473 K, the relative permittivity of the decarburized materials increases initially and then decreases, whereas the relative permeability exhibits an opposite change trend. As holding time ranges from 40 to 60 min at 1273 K, the relative permittivity and dielectric loss factor tend to decrease while the relative permeability and magnetic loss factor tend to increase, corresponding to the maximum mean velocity of decarburization. In microwave fields, electromagnetic properties of the decarburized materials principally vary with carbon content, C-vacancies and crystal structure, and their changes in turn affect the interaction of microwaves with the decarburized materials

  7. SOLID-STATE PHASE TRANSFORMATION OF WELDED METAL IN CONTROL OF WELDING DISTORTION PROCESS

    Institute of Scientific and Technical Information of China (English)

    Wang Wenxian; Huo Lixing; Zhang Yufeng; Wang Dongpo; Jing Hongyang

    2005-01-01

    Based on the tests of a build-up welding at plate edge (BWPE) and a multi-layer build-up welding on plate (MBWP), the article studies on the solid-state phase transformations which affect welding distortion process and on the influence rule of transformation starting temperature (TST) of welded metal to the welding residual distortion. The welding distortion can be decreased or controlled by the transformation volume expansion caused by solid-state phase transformation of welded metal during the cooling. The test results of BWPE show that when TST is at about 190 C, the bending distortion of welded specimen is the smallest, and its displacements at free end are decreased to 58%and 67% compared with those of conventional welding electrodes Al02 and E5015, which TST are less than room temperature and equal to 758 ℃ respectively. The test results of MBWP show that when TST were at 100~250 ℃, the welded specimen would appear reversible bending distortion compared with those of Al02 and E5015. The maximum deflection value of reversible bending distortion in 8 mm thick plate is -2.94 mm at about 170 ℃ of TST. The test results provide a valuable method to decrease or to control welding residual distortion.

  8. Photodegradation of polycyclic aromatic hydrocarbon pyrene by iron oxide in solid phase

    International Nuclear Information System (INIS)

    To better understand the photodegradation of polycyclic aromatic hydrocarbons (PAH) in solid phase in natural environment, laboratory experiments were conducted to study the influencing factors, kinetics and intermediate compound of pyrene photodegradation by iron oxides. The results showed that the pyrene photodegradation rate followed the order of α-FeOOH > α-Fe2O3 > γ-Fe2O3 > γ-FeOOH at the same reaction conditions. Lower dosage of α-FeOOH and higher light intensity increased the photodegradation rate of pyrene. Iron oxides and oxalic acid can set up a photo-Fenton-like system without additional H2O2 in solid phase to enhance the photodegradation of pyrene under UV irradiation. All reaction followed the first-order reaction kinetics. The half-life (t1/2) of pyrene in the system showed the higher efficiencies of using iron oxide as photocatalyst to degrade pyrene. Intermediate compound pyreno was found during photodegradation reactions by gas chromatography-mass spectrometry (GC-MS). The photodegradation efficiency for PAHs in this photo-Fenton-like system was also confirmed by using the contaminated soil samples. This work provides some useful information to understand the remediation of PAHs contaminated soils by photochemical techniques under practical condition

  9. Evaluation of solid-phase microextraction in detection of contraband drug vapors

    Science.gov (United States)

    Orzechowska, Grazyna E.; Poziomek, Edward J.; Tersol, Vangielynn; Homstead, Juliana

    1997-02-01

    Solid phase microextraction (SPME) has emerged as a rapid alternative to conventional sample extraction techniques. SPME can be used in solids, liquids, and sample headspace. Compounds are sorbed by a stationary phase coated on a fused silica fiber. The compounds are desorbed, and analyzed using gas chromatography (GC), and high performance liquid chromatography (HPLC). As a part of the present work we have found that SPME can also be used conveniently with ion mobility spectrometry (IMS). Cocaine and heroin vapors sorbed on a SPME fiber were detected using IMS. The use of SPME-GC or SPME-HPLC has been reported in analysis of urine samples containing cocaine and its metabolites. We are evaluating SPME-IMS, and SPME-GC systems for the detection of cocaine and heroin and their decomposition products in the headspace above surfaces. This is part of our research on the surface decomposition of contraband drugs for detection applications. This paper will give a variety of examples in the use of SPME in the detection of contraband drugs and their reaction/decomposition products in the vapor state. An example is the detection of cocaine in the headspace above cocaine HCl at room temperature.

  10. Matrix compatible solid phase microextraction coating, a greener approach to sample preparation in vegetable matrices.

    Science.gov (United States)

    Naccarato, Attilio; Pawliszyn, Janusz

    2016-09-01

    This work proposes the novel PDMS/DVB/PDMS fiber as a greener strategy for analysis by direct immersion solid phase microextraction (SPME) in vegetables. SPME is an established sample preparation approach that has not yet been adequately explored for food analysis in direct immersion mode due to the limitations of the available commercial coatings. The robustness and endurance of this new coating were investigated by direct immersion extractions in raw blended vegetables without any further sample preparation steps. The PDMS/DVB/PDMS coating exhibited superior features related to the capability of the external PDMS layer to protect the commercial coating, and showed improvements in terms of extraction capability and in the cleanability of the coating surface. In addition to having contributed to the recognition of the superior features of this new fiber concept before commercialization, the outcomes of this work serve to confirm advancements in the matrix compatibility of the PDMS-modified fiber, and open new prospects for the development of greener high-throughput analytical methods in food analysis using solid phase microextraction in the near future. PMID:27041299

  11. Solid-phase characterization in flammable-gas-tank sludges by electron microscopy

    International Nuclear Information System (INIS)

    The crystallinity, morphology, chemical composition, and crystalline phases of several Tank 241-SY-101 (hereinafter referred to as SY-101) and Tank 241-SY-103 (hereinafter referred to as SY-103) solid samples were studied by transmission electron microscopy (TEM), electron energy dispersive spectroscopy (EDS), and electron diffraction. The main focus is on the identification of aluminum hydroxide thought to be present in these tank samples. Aluminum hydroxide was found in SY-103, but not in SY-101. This difference can be explained by the different OH/Al ratios found in the two tank samples: a high OH/Al ratio in SY-101 favors the formation of sodium aluminate, but a low OH/Al ratio in SY-103 favors aluminum hydroxide. These results were confirmed by a magnetic resonance study on SY-101 and SY-103 simulant. The transition from aluminum hydroxide to sodium aluminate occurs at an OH/Al molar ratio of 3.6. It is believed that the study of Al(OH)3 was not affected by sample preparation because all Al(OH)3 is in the solid form according to the NMR experiments. There is no Al(OH)3 in the liquid. It is, therefore, most likely that the observation of Al(OH)3 is representative of the real sludge sample, and is not affected by drying. Similar conclusions also apply to other insoluble phases such as iron and chromium

  12. Solid-propellant rocket motor internal ballistic performance variation analysis, phase 2

    Science.gov (United States)

    Sforzini, R. H.; Foster, W. A., Jr.

    1976-01-01

    The Monte Carlo method was used to investigate thrust imbalance and its first time derivative throughtout the burning time of pairs of solid rocket motors firing in parallel. Results obtained compare favorably with Titan 3 C flight performance data. Statistical correlations of the thrust imbalance at various times with corresponding nominal trace slopes suggest several alternative methods of predicting thrust imbalance. The effect of circular-perforated grain deformation on internal ballistics is discussed, and a modified design analysis computer program which permits such an evaluation is presented. Comparisons with SRM firings indicate that grain deformation may account for a portion of the so-called scale factor on burning rate between large motors and strand burners or small ballistic test motors. Thermoelastic effects on burning rate are also investigated. Burning surface temperature is calculated by coupling the solid phase energy equation containing a strain rate term with a model of gas phase combustion zone using the Zeldovich-Novozhilov technique. Comparisons of solutions with and without the strain rate term indicate a small but possibly significant effect of the thermoelastic coupling.

  13. Use of Solid Phase Second Antibody for the Radioimmunoassay of T3

    International Nuclear Information System (INIS)

    Solid phase second antibody separation techniques includes the reaction between antigen and the first antibody takes place in the liquid phase after which the bounded antigen fraction is separated by the addition of a second antibody immobilised on a solid support. In the present study purified goat anti rabbit gamma globulin was immobilised on magnetised polyacrolein particles. The titre of the product was determined followed by assay design to optimise reagent volumes and incubation time. Experimental results showed that a design using 50μl of standard T solution, 50 μl of 125I-labeled T3, 50 μl of T3 antibody solution, first incubation time of 2 hours at 37oC and the addition of 50 μl of second antibody magnetic particles suspension followed by a second incubation for 1 hour yielded sufficient sensitivity and satisfactory results in the working area of interest. Assay performance was tested by comparing the characteristic parameter values with those of the control, i.e. commercial RIA-T3 kits from BATAN/Amersham and the double antibody separation method described previously. Stability testing of the second antibody magnetic particles was determined by evaluation of the maximum and nonspecific binding values over time, the suspension of magnetised particles was shown to be sufficiently stable for at least 3 months when stored at 4oC. (author). 3 tabs., 4 figs

  14. Nutritive values of solid heavy phase in replacing corn in broilers diet

    Directory of Open Access Journals (Sweden)

    A.P Sinurat

    2006-10-01

    Full Text Available Indonesia is still importing corn for feed. Utilization of nonconventional feedstuffs may reduce this importation. One of them is solid heavy phase (SHP, i.e., a solid substance gained after filtration of liquid waste of crude palm oil factory with a potential production approximately 2 million ton/year. This research was carried out to study the utilization of SHP to replace corn in broiler’s diet. The SHP was dried and analysed for its nutrient compositions. The metabolisable energy was measured by using hens. Feeding trial was then conducted by replacing corn with SHP in various levels, i.e., 0 (Control, 10, 20, 30, and 40%. All diets were formulated to be isocalori dan isonitrogen. Five hundred broilers DOC were used in this trial and fed for 5 weeks. The performances of the birds were obsereved as parameters. Results showed that the ash, minerals crude fibre and fat contents of the SHP were higher than the corn. The crude protein of the SHP was similar to that of corn, but some amino acids content of the SHP were lower than the corn. The AME and TME values of SHP were 3271 and 3465 cal/g, respectively. Results of feeding trial showed that body weight of the birds were less as the level of SHP to replace corn increased in the diet. The FCR also showed impared as the levels of SHP increased in the diet. However, replacement of 10% corn with SHP did not significantly affect the body weight and FCR as compared with the control. Feed consumptions of the birds were not significantly affected by replacing corn with SHP. Carcass yield and relative weights of some internal organs were not significantly different between dietary treatments. It is concluded that the solid heavy phase could be used to replace 10% corn in broiler’s diet.

  15. Heavy metal levels and solid phase speciation in street dusts of Delhi, India

    International Nuclear Information System (INIS)

    Although the street dusts of Delhi contain considerably high levels of Cr, Ni, Cu, Cd, Zn and Pb, solid phase speciation results indicate comparatively limited environmental mobility and bioavailability of Ni and Cr. - Street dust samples were collected from three different localities (industrial, heavy traffic and rural) situated in the greater Delhi area of India. The samples analyzed for Cd, Zn, Pb, Ni, Cu, and Cr indicated remarkably high levels of Cr, Ni, and Cu in the industrial area, whilst Pb and Cd did not show any discernible variations between the three localities. A multivariate statistical approach (Principal Component Analysis) was used to define the possible origin of metals in dusts. The street dusts were sequentially extracted so that the solid pools of Cd, Zn, Pb, Ni, Cu, Cr could be partitioned into five operationally defined fractions viz. exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and residual. Metal recoveries in sequential extractions were ±10% of the independently measured total metal concentrations. Cd was the only metal present appreciably (27.16%) in the exchangeable fraction and Cu was the only metal predominantly associated (44.26%) with organic fraction. Zn (45.64%) and Pb (28.26%) were present mainly in the Fe-Mn oxide fraction and the residual fraction was the most dominant solid phase pool of Cr (88.12%) and Ni (70.94%). Assuming that the mobility and bioavailability are related to the solubility of geochemical forms of the metals and decrease in order of extraction, the apparent mobility and potential metal bioavailability for these highly contaminated street dust samples is: Cd>Zn congruent with Pb>Ni>Cu>Cr

  16. Multiple headspace-solid-phase microextraction: An application to quantification of mushroom volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Rosaria; Tedone, Laura; De Grazia, Selenia [Dipartimento Farmaco-chimico, University of Messina, viale Annunziata, 98168 Messina (Italy); Dugo, Paola [Dipartimento Farmaco-chimico, University of Messina, viale Annunziata, 98168 Messina (Italy); Centro Integrato di Ricerca (C.I.R.), Università Campus-Biomedico, Via Álvaro del Portillo, 21, 00128 Roma (Italy); Mondello, Luigi, E-mail: lmondello@unime.it [Dipartimento Farmaco-chimico, University of Messina, viale Annunziata, 98168 Messina (Italy); Centro Integrato di Ricerca (C.I.R.), Università Campus-Biomedico, Via Álvaro del Portillo, 21, 00128 Roma (Italy)

    2013-04-03

    Highlights: ► Multiple headspace extraction-solid phase microextraction (MHS-SPME) has been applied to the analysis of Agaricus bisporus. ► Mushroom flavor is characterized by the presence of compounds with a 8-carbon atoms skeleton. ► Formation of 8-carbon compounds involves a unique fungal biochemical pathway. ► The MHS-SPME allowed to determine quantitatively 5 target analytes of A. bisporus for the first time. -- Abstract: Multiple headspace-solid phase microextraction (MHS-SPME) followed by gas chromatography/mass spectrometry (GC–MS) and flame ionization detection (GC–FID) was applied to the identification and quantification of volatiles released by the mushroom Agaricus bisporus, also known as champignon. MHS-SPME allows to perform quantitative analysis of volatiles from solid matrices, free of matrix interferences. Samples analyzed were fresh mushrooms (chopped and homogenized) and mushroom-containing food dressings. 1-Octen-3-ol, 3-octanol, 3-octanone, 1-octen-3-one and benzaldehyde were common constituents of the samples analyzed. Method performance has been tested through the evaluation of limit of detection (LoD, range 0.033–0.078 ng), limit of quantification (LoQ, range 0.111–0.259 ng) and analyte recovery (92.3–108.5%). The results obtained showed quantitative differences among the samples, which can be attributed to critical factors, such as the degree of cell damage upon sample preparation, that are here discussed. Considerations on the mushrooms biochemistry and on the basic principles of MHS analysis are also presented.

  17. Environmental mobility of cobalt-Influence of solid phase characteristics and groundwater chemistry

    International Nuclear Information System (INIS)

    The adsorption of cobalt on samples from a potential waste repository site in an arid region was investigated in batch experiments, as a function of various solution phase parameters including the pH and ionic strength. The samples were characterized using a range of techniques, including BET surface area measurements, total clay content and quantitative X-ray diffraction. The statistical relationships between the measured cobalt distribution coefficients (Kd values) and the solid and liquid phase characteristics were assessed. The sorption of cobalt increased with the pH of the aqueous phase. In experiments with a fixed pH value, the measured Kd values were strongly correlated to the BET surface area, but not to the amount of individual clay minerals (illite, kaolinite or smectite). A further set of sorption experiments was undertaken with two samples of distinctive mineralogy and surface area, and consequently different sorption properties. A simple surface complexation model (SCM) that conceptualized the surface sites as having equivalent sorption properties to amorphous Fe-oxide was moderately successful in explaining the pH dependence of the sorption data on these samples. Two different methods of quantifying the input parameters for the SCM were assessed. While a full SCM for cobalt sorption on these complex environmental substrates is not yet possible, the basic applicability and predictive capability of this type of modeling is demonstrated. A principal requirement to further develop the modeling approach is adequate models for cobalt sorption on component mineral phases of complex environmental sorbents.

  18. Mixed micelle cloud point-magnetic dispersive μ-solid phase extraction of doxazosin and alfuzosin.

    Science.gov (United States)

    Gao, Nannan; Wu, Hao; Chang, Yafen; Guo, Xiaozhen; Zhang, Lizhen; Du, Liming; Fu, Yunlong

    2015-01-01

    Mixed micelle cloud point extraction (MM-CPE) combined with magnetic dispersive μ-solid phase extraction (MD-μ-SPE) has been developed as a new approach for the extraction of doxazosin (DOX) and alfuzosin (ALF) prior to fluorescence analysis. The mixed micelle anionic surfactant sodium dodecyl sulfate and non-ionic polyoxyethylene(7.5)nonylphenylether was used as the extraction solvent in MM-CPE, and diatomite bonding Fe₃O₄ magnetic nanoparticles were used as the adsorbent in MD-μ-SPE. The method was based on MM-CPE of DOX and ALF in the surfactant-rich phase. Magnetic materials were used to retrieve the surfactant-rich phase, which easily separated from the aqueous phase under magnetic field. At optimum conditions, a linear relationship between DOX and ALF was obtained in the range of 5-300 ng mL(-1), and the limits of detection were 0.21 and 0.16 ng mL(-1), respectively. The proposed method was successfully applied for the determination of the drugs in pharmaceutical preparations, urine samples, and plasma samples. PMID:24995413

  19. Vapour phase approach for iron oxide nanoparticle synthesis from solid precursors

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mandeep; Ulbrich, Pavel; Prokopec, Vadym [Institute of Chemical Technology Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Svoboda, Pavel [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 5, 120 00 Prague 2 (Czech Republic); Šantavá, Eva [Institute of Physics ASCR, Na Slovance 2, 182 21 Prague 8 (Czech Republic); Štěpánek, František, E-mail: Frantisek.Stepanek@vscht.cz [Institute of Chemical Technology Prague, Technicka 5, 166 28 Prague 6 (Czech Republic)

    2013-04-15

    A new non-solution mediated approach to the synthesis of iron oxide nanoparticles directly from solid FeCl{sub 2} salt precursors has been developed. The method is rapid, simple and scalable. The structural properties and the phase of the resulting iron oxide particles has been determined by a range of methods including XRD, FT-IR and Mössbauer spectroscopy, and the phase is shown to be maghemite (γ-Fe{sub 2}O{sub 3}). The magnetic properties of the iron oxide particles have been measured using SQUID, confirming superparamagnetic behaviour of the powder and a saturation magnetization of 53.0 emu g{sup −1} at 300 K. Aqueous dispersions at increasing concentrations were prepared and their heating rate under a 400 kHz alternating magnetic field measured. The specific absorption rate (SAR) of the iron oxide was found to be 84.8 W g{sup −1}, which makes the material suitable for the formulation of ferrofluids or ferrogels with RF heating properties. - Graphical Abstract: Superparamagnetic iron oxide nanoparticles obtained by a novel vapour phase approach. Highlights: ► Novel vapour phase (non-solvent) approach for iron oxide nanoparticle synthesis. ► Attractive alternative approach to the present co-precipitation method. ► Better magnetic properties with high coercivity of nanoparticles. ► A high specific absorption rate (SAR) for hyperthermia applications.

  20. (Solid + liquid) phase equilibria and heat capacity of (diphenyl ether + biphenyl) mixtures used as thermal energy storage materials

    International Nuclear Information System (INIS)

    Highlights: • A DSC calorimeter for measuring (solid + liquid) phase equilibrium and heat capacities is presented. • (Diphenyl ether + biphenyl) system presents a eutectic (solid + liquid) phase diagram with complete immiscibility in solid phase. • The T, x conditions of the eutectic point are x = (0.705 and 285.6) K, while 93.2 J · g−1 · K−1 is the latent heat of fusion. • The Wilson and NRTL equations, and the predictive UNIFAC model describes adequately the solid liquid phase equilibrium data. • The system exhibits high and positive excess heat capacities which can be correlated by using a Redlich–Kister equation. - Abstract: The (solid + liquid) phase equilibrium for eight {x diphenyl ether + (1 − x) biphenyl} binary mixtures, including the eutectic mixture were studied by using a differential scanning calorimetry (DSC) technique. A good agreement was found between previous literature and experimental values here presented for the melting point and enthalpy of fusion of pure compounds. The well-known equations for Wilson and the non-random two-liquid (NRTL) were used to correlate experimental solid liquid phase equilibrium data. Moreover, the predictive mixture model UNIFAC has been employed to describe the phase diagram. With the aim to check this equipment to measure heat capacities in the quasi-isothermal Temperature-Modulated Differential Scanning Calorimetry method (TMDSC), four fluids of well-known heat capacity such as toluene, n-decane, cyclohexane and water were also studied in the liquid phase at temperatures ranging from (273.15 to 373.15) K. A good agreement with literature values was found for those fluids of pure diphenyl ether and biphenyl. Additionally, the specific isobaric heat capacities of diphenyl ether and biphenyl binary mixtures in the liquid phase up to T = 373.15 K were measured

  1. Numerical simulation on the performance of the vortex pump for transporting solid-liquid two-phase with light particles

    Science.gov (United States)

    Mao, W. Y.; Song, P. Y.; Deng, Q. G.; Xu, H. J.

    2016-05-01

    With the purpose of studying performance of the vortex pump for transporting solid-liquid two-phase with light particles whose relative density smaller than 1, the numerical simulation of solid-liquid two phase flowing in the whole channel of a vortex pump with the particle diameter being 0.5 mm, 1 mm, 2 mm, 3 mm and the initial solid phase volume concentrations being 10%, 20% and 30% are respectively carried out by using the commercial software ANSYS Fluent by adopting RNG κ-ɛ turbulent flow model, Eulerian-Eulerian multi-phase flow model and SIMPLEC algorithm. The simulation results show that in the impeller region, the particles concentrate on the non-working surface of the blades, and the particles are rare on the working surface of the blades. As the initial solid phase volume concentration and particle diameter increase, the pump delivery head of vortex pump decrease. The pump delivery head of vortex pump with different initial solid phase concentrations and different particle diameters are predicted and compared with those obtained by an empirical formula, and they shows good agreement.

  2. The research on particle trajectory of solid-liquid two-phase flow and erosion predicting in screw centrifugal pump

    Science.gov (United States)

    Shen, Z. J.; Li, R. N.; Han, W.; Zhao, W. G.; Wang, X. H.

    2016-05-01

    Use the Discrete Phase Model (DPM) based on Euler-Lagrange method, the internal flow field of screw centrifugal pump was simulated by computational fluid dynamics(CFD) code when transmission medium is solid-liquid two phase flow with large-size particles. The research of liquid phase is under the Euler coordinate system while the solid phase is under the Lagrange coordinate system. The energy change, trajectory characteristic of solid phase particle and its erosion damage rule of solid-phase particle in whole computational domain is analyzed with different density, partical size(d=0.05mm, d=0.2mm, d=2mm) and solid volume fraction(Cv=3%, Cv=5%, Cv=7%).The result shows that within a given diameter range, the low density fine particles trajectory are longer, more collision times with flow passage components, more energy loss and the erosion parts are relatively uniform, but particles which are large-size diameter and high density has a big collision angle with the surface of impeller and volute, even the area of impact and abrasion are quite focus, and easy to be transported. particles will impact with the head of impeller when it enter into impeller domain, the erosion mainly occurs on the work side of impeller.

  3. Multiplex Solid-Phase PCR for Rapid Detection and Identification of Salmonella spp. at Sub-species

    DEFF Research Database (Denmark)

    Cao, Cuong; Høgberg, Jonas; Wolff, Anders;

    . Simultaneously on the solid phase, the amplified PCR amplicons interact with the nested DNA probes immobilized on the solid substrate as an array. If the immobilized probes match the sequence of the DNA templates they are extended by the polymerase and serve as template for the second strand elongation primed by......This study presents a solid-phase PCR (SP-PCR) for rapid detection, identification, and sub-typing of various Salmonella species, the major food-borne cause of salmonellosis. The target DNA is firstly amplified with PCR primers (one primer is labeled with fluorophores) in the liquid phase...... the liquid phase primer thus generating new templates for the SP-PCR. After the reaction, PCR products labeled with fluorophores remain attached to the substrate and can be visualized directly by fluorescence readout devices. Using this method, S. enteritidis, S. typhimurium and S. dublin can be...

  4. Solid-phase Synthesis of Combinatorial 2,4-Disubstituted-1,3,5-Triazine via Amine Nucleophilic Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sung Won [KIST Gangneung Institute, Gangneung (Korea, Republic of); Ham, Jungyeob [Gangneung-Wonju National University, Gangneung (Korea, Republic of); Chang, Young-Tae [National University of Singapore, Singapore (Singapore); Lee, Jae Wook [University of Science and Technology, Daejon (Korea, Republic of)

    2015-01-15

    In combinatorial chemistry, solid-phase synthesis is a popular approach formass production of small molecules. Compared to solution-phase synthesis, it is easy to prepare and purify a large number of heterocyclic small molecules via solid-phase chemistry; the overall reaction time is decreased as well. 1,3,5-Triazine is a nitrogen-containing heterocyclic aromatic scaffold that was shown to be a druggable scaffold in recent studies. These structures have been reported as anticancer, antimicrobial, and antiretroviral compounds, as CDKs and p38 MAP kinase inhibitors, as estrogen receptor modulators, and as inosine monophosphate dehydrogenase inhibitors. we designed and synthesized disubstituted triazine compounds as an analog of disubstituted pyrimidine compounds. These disubstituted triazine compounds possess a linear structure which may have biological activity similar to that of disubstituted pyrimidine. Here we report the solid-phase synthesis of disubstituted triazine compounds.

  5. Solid-phase Synthesis of Combinatorial 2,4-Disubstituted-1,3,5-Triazine via Amine Nucleophilic Reaction

    International Nuclear Information System (INIS)

    In combinatorial chemistry, solid-phase synthesis is a popular approach formass production of small molecules. Compared to solution-phase synthesis, it is easy to prepare and purify a large number of heterocyclic small molecules via solid-phase chemistry; the overall reaction time is decreased as well. 1,3,5-Triazine is a nitrogen-containing heterocyclic aromatic scaffold that was shown to be a druggable scaffold in recent studies. These structures have been reported as anticancer, antimicrobial, and antiretroviral compounds, as CDKs and p38 MAP kinase inhibitors, as estrogen receptor modulators, and as inosine monophosphate dehydrogenase inhibitors. we designed and synthesized disubstituted triazine compounds as an analog of disubstituted pyrimidine compounds. These disubstituted triazine compounds possess a linear structure which may have biological activity similar to that of disubstituted pyrimidine. Here we report the solid-phase synthesis of disubstituted triazine compounds

  6. Aldolase exists in both the fluid and solid phases of cytoplasm.

    Science.gov (United States)

    Pagliaro, L; Taylor, D L

    1988-09-01

    We have prepared a functional fluorescent analogue of the glycolytic enzyme aldolase (rhodamine [Rh]-aldolase), using the succinimidyl ester of carboxytetramethyl-rhodamine. Fluorescence redistribution after photobleaching measurements of the diffusion coefficient of Rh-aldolase in aqueous solutions gave a value of 4.7 x 10(-7) cm2/S, and no immobile fraction. In the presence of filamentous actin, there was a 4.5-fold reduction in diffusion coefficient, as well as a 36% immobile fraction, demonstrating binding of Rh-aldolase to actin. However, in the presence of a 100-fold molar excess of its substrate, fructose 1,6-diphosphate, both the mobile fraction and diffusion coefficient of Rh-aldolase returned to control levels, indicating competition between substrate binding and actin cross-linking. When Rh-aldolase was microinjected into Swiss 3T3 cells, a relatively uniform intracellular distribution of fluorescence was observed. However, there were significant spatial differences in the in vivo diffusion coefficient and mobile fraction of Rh-aldolase measured with fluorescence redistribution after photobleaching. In the perinuclear region, we measured an apparent cytoplasmic diffusion coefficient of 1.1 x 10(-7) cm2/s with a 23% immobile fraction; while measurements in the cell periphery gave a value of 5.7 x 10(-8) cm2/s, with no immobile fraction. Ratio imaging of Rh-aldolase and FITC-dextran indicated that FITC-dextran was relatively excluded excluded from stress fiber domains. We interpret these data as evidence for the partitioning of aldolase between a soluble fraction in the fluid phase and a fraction associated with the solid phase of cytoplasm. The partitioning of aldolase and other glycolytic enzymes between the fluid and solid phases of cytoplasm could play a fundamental role in the control of glycolysis, the organization of cytoplasm, and cell motility. The concepts and experimental approaches described in this study can be applied to other cellular

  7. Molecular Simulation of the Free Energy for the Accurate Determination of Phase Transition Properties of Molecular Solids

    Science.gov (United States)

    Sellers, Michael; Lisal, Martin; Brennan, John

    2015-06-01

    Investigating the ability of a molecular model to accurately represent a real material is crucial to model development and use. When the model simulates materials in extreme conditions, one such property worth evaluating is the phase transition point. However, phase transitions are often overlooked or approximated because of difficulty or inaccuracy when simulating them. Techniques such as super-heating or super-squeezing a material to induce a phase change suffer from inherent timescale limitations leading to ``over-driving,'' and dual-phase simulations require many long-time runs to seek out what frequently results in an inexact location of phase-coexistence. We present a compilation of methods for the determination of solid-solid and solid-liquid phase transition points through the accurate calculation of the chemical potential. The methods are applied to the Smith-Bharadwaj atomistic potential's representation of cyclotrimethylene trinitramine (RDX) to accurately determine its melting point (Tm) and the alpha to gamma solid phase transition pressure. We also determine Tm for a coarse-grain model of RDX, and compare its value to experiment and atomistic counterpart. All methods are employed via the LAMMPS simulator, resulting in 60-70 simulations that total 30-50 ns. Approved for public release. Distribution is unlimited.

  8. Preparation of molybdenum borides by combustion synthesis involving solid-phase displacement reactions

    International Nuclear Information System (INIS)

    Preparation of molybdenum borides of five different phases in the Mo-B binary system (including Mo2B, MoB, MoB2, Mo2B5, and MoB4) was performed by self-propagating high-temperature synthesis (SHS) with two kinds of the reactant samples. When elemental powder compacts with an exact stoichiometry corresponding to the boride phase were employed, self-sustaining reaction was only achieved in the sample with Mo:B = 1:1 and nearly single-phase MoB was yielded. Therefore, the other four boride compounds were prepared from the reactant compacts composed of MoO3, Mo, and B powders, within which the displacement reaction of MoO3 with boron was involved in combustion synthesis. Experimental evidence shows that the extent of displacement reaction in the overall reaction has a significant impact on sustainability of the synthesis reaction, combustion temperature, reaction front velocity, and composition of the end product. An increase in the solid-phase displacement reaction taking place during the SHS process contributes more heat flux to the synthesis reaction, thus resulting in the increase of combustion temperature and enhancement of the reaction front velocity. Based upon the XRD analysis, formation of Mo2B, MoB2, and Mo2B5 as the dominant boride phase in the end product was successful through the SHS reaction with powder compacts under appropriate stoichiometries between MoO3, Mo, and B. However, a poor conversion was observed in the synthesis of MoB4. The powder compact prepared for the production of MoB4 yielded mostly Mo2B5

  9. Characterization of solid phases and study of transformation kinetics in m-chlorofluorobenzene by 35Cl nuclear quadrupole resonance.

    Science.gov (United States)

    Pérez, Silvina; Wolfenson, Alberto

    2012-02-01

    Polymorphism is of widespread occurrence in the world of molecular crystals. In this work we present experimental results showing the existence of four solid phases in m-chlorofluorobenzene. A glass structure is achieved by quenching the liquid phase at 77 K. This glassy state crystallizes in a disordered phase at T~143 K, which in turn transforms to the high-temperature stable phase (phase I) at T~153 K. Depending on the thermal history of the sample, a different ordered phase (phase III) can be obtained. The disorder is attributed to a molecular orientational disorder. There is no evidence of molecular reorientation in any phase. A study of the disorder-order phase transformation kinetics, using nuclear quadrupole resonance, is presented. The results are analyzed following Cahn's theory. Nucleation seems to take place at grain boundaries. Growth rates for different temperatures have been determined. PMID:22209621

  10. Preparation of molecularly imprinted polymeric fibers using a single bifunctional monomer for the solid-phase microextraction of parabens from environmental solid samples.

    Science.gov (United States)

    Díaz-Álvarez, Myriam; Smith, Stephen P; Spivak, David A; Martín-Esteban, Antonio

    2016-02-01

    In this study, molecularly imprinted polymer fibers for solid-phase microextraction have been prepared with a single bifunctional monomer, N,O-bismethacryloyl ethanolamine using the so-called "one monomer molecularly imprinted polymers" method, replacing the conventional combination of functional monomer and cross-linker to form high fidelity binding sites. For comparison, imprinted fibers were prepared following the conventional approach based on ethylene glycol dimethacrylate as cross-linker and methacrylic acid as monomer. The recognition performance of the new fibers was evaluated in the solid-phase microextraction of parabens, and from this study it was concluded that they provided superior performance over conventionally formulated fibers. Ultimately, real-world environmental testing on spiked solid samples was successful by the molecularly imprinted solid-phase microextraction of samples, and the relative recoveries obtained at enrichment levels of 10 ng/g of parabens were within 78-109% for soil and 83-109% for sediments with a relative standard deviation <15% (n = 3). PMID:26582435

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

    International Nuclear Information System (INIS)

    The anaerobic digestion of onion residual from an onion processing plant was studied under batch-fed and continuously-fed mesophilic (35 ± 2 oC) conditions in an Anaerobic Phased Solids (APS) Digester. The batch digestion tests were performed at an initial loading of 2.8 gVS L-1 and retention time of 14 days. The biogas and methane yields, and volatile solids reduction from the onion residual were determined to be 0.69 ± 0.06 L gVS-1, 0.38 ± 0.05 L CH4 gVS-1, and 64 ± 17%, respectively. Continuous digestion tests were carried out at organic loading rates (OLRs) of 0.5-2.0 gVS L-1 d-1. Hydrated lime (Ca(OH)2) was added to the APS-Digester along with the onion residual at 16 mg Ca(OH)2 gVS-1 to control the pH of the biogasification reactor above 7.0. At steady state the average biogas yields were 0.51, 0.56, and 0.62 L gVS-1 for the OLRs of 0.5, 1.0, and 2.0 gVS L-1 d-1 respectively. The methane yields at steady state were 0.29, 0.32, and 0.31 L CH4 gVS-1 for the OLRs of 0.5, 1.0, and 2.0 gVS L-1 d-1 respectively. The study shows that the digestion of onion residual required proper alkalinity and pH control, which was possible through the use of caustic chemicals. However, such chemicals will begin to have an inhibitory effect on the microbial population at high loading rates, and therefore alternative operational parameters are needed. -- Highlights: → An APS-Digester was used to study biogas production from onion solid residues. → Biogas and methane yields from onion solids were determined. → Study showed substantial findings for treating onion solid residues.

  12. Early Phases of Jupiter's Formation from an Evolving Disk of Solids

    Science.gov (United States)

    D'Angelo, G.; Weidenschilling, S. J.; Lissauer, J. J.; Bodenheimer, P.

    2014-12-01

    We are performing calculations of the formation of Jupiter via core nucleated accretion and gas capture. The calculations model the growth of a solid core from an evolving disk of planetesimals and the growth of a contracting gaseous envelope. We present results of the early phases of formation. The evolution of the solids accounts for growth and fragmentation, viscous and gravitational stirring, and for drag-assisted migration and velocity damping operated by the disk's gas. The envelope structure accounts for mass and energy deposition due to the ablation of planetesimals that move through the envelope. The envelope's opacity takes into account coagulation and sedimentation of dust particles released by ablating planetesimals. The core starts as a seed body of 350 km in radius, orbiting at 5.2 AU in a disk of planetesimals whose initial radii range from 15 m to 50 km. The initial surface density of the solids is 10 g/cm^2 at the seed's location. During the evolution of the solids, most of the mass resides in bodies of several tens of km in radius. These are also the planetesimals that provide most of the solids accretion to the planet. By comparing results with a calculation that does not account for the envelope bound to the core, we find that the size-dependent cross-section of the planet for the accretion of planetesimals is substantially enhanced by a low-mass, but voluminous envelope. The calculation without the envelope produces a core of 4.4 Earth masses (Mearth) after about 1 Myr, and an extrapolated mass of about 5 Mearth after 6 Myr. The full calculation with envelope yields a core of 7.3 Mearth and an envelope of 0.15 Mearth after about 0.4 Myr. At this point of the planet's evolution, the envelope accretion rate exceeds that of the core. Over the following 1 Myr, the core mass reaches about 8 Mearth and the envelope mass grows to about 4 Mearth. Support from NASA Outer Planets Research Program is gratefully acknowledged.

  13. A solid-phase extraction approach for the identification of pharmaceutical-sludge adsorption mechanisms

    Institute of Scientific and Technical Information of China (English)

    Laurence Berthod; Gary Roberts; Graham A. Mills

    2014-01-01

    It is important to understand the adsorption mechanism of chemicals and active pharmaceu-tical ingredients (API) on sewage sludge since wastewater treatment plants are the last barrier before the release of these compounds to the environment. Adsorption models were developed considering mostly hydrophobic API-sludge interaction. They have poor predictive ability, especially with ionisable compounds. This work proposes a solid-phase extraction (SPE) approach to estimate rapidly the API-sludge interaction. Sludge-filled SPE cartridges could not be percolated with API spiked mobile phases so different powders were tested as SPE sludge supports. Polytetrafluoroethylene (PTFE) was selected and tested at different PTFE/sludge ratios under eight different adsorption conditions with three API ionisable compounds. The PTFE/sludge mixtures with 50% or less sludge could be used in SPE mode for API sorption studies with methanol/water liquid phases. The results gave insights into API-sludge interactions. It was found that π-π, hydrogen-bonding and charge-charge interactions were as important as hydrophobicity in the adsorption mechanism of charged APIs on sludge.

  14. A solid-phase extraction approach for the identification of pharmaceutical–sludge adsorption mechanisms

    Directory of Open Access Journals (Sweden)

    Laurence Berthod

    2014-04-01

    Full Text Available It is important to understand the adsorption mechanism of chemicals and active pharmaceutical ingredients (API on sewage sludge since wastewater treatment plants are the last barrier before the release of these compounds to the environment. Adsorption models were developed considering mostly hydrophobic API–sludge interaction. They have poor predictive ability, especially with ionisable compounds. This work proposes a solid-phase extraction (SPE approach to estimate rapidly the API–sludge interaction. Sludge-filled SPE cartridges could not be percolated with API spiked mobile phases so different powders were tested as SPE sludge supports. Polytetrafluoroethylene (PTFE was selected and tested at different PTFE/sludge ratios under eight different adsorption conditions with three API ionisable compounds. The PTFE/sludge mixtures with 50% or less sludge could be used in SPE mode for API sorption studies with methanol/water liquid phases. The results gave insights into API–sludge interactions. It was found that π–π, hydrogen-bonding and charge–charge interactions were as important as hydrophobicity in the adsorption mechanism of charged APIs on sludge.

  15. Determination of Metamizole Sodium and Chlorphenamine Maleate in Zhongganling Tablets by Solid-Phase Extracting HPLC

    Institute of Scientific and Technical Information of China (English)

    HANG Yiying; ZHU Binghui; LU Huiwen; YU Jinxiong; DEN Zhihua

    2002-01-01

    Objective To establish a method for the determination of metamizole sodium and chlorphenamine maleate in Zhongganling tablets. Methods The sample was determined by ion - pair HPLC after it was purified on Sep- Pak C18 microcolumn. The chromatographic conditions included: Hypersil DBS C18 chromatographic column(250mm × 4.6mm, i.d. 5μm) as an analytical column, methanolmixed solution of sodium heptanesulfonate and glacial acetic acid(600:400) as a mobile phase, the demetamizole sodium and chlorphenamine malcate were 99.6% (RSD was 2.1% and n was 6) and 98.0%(RSD was 1.5% and n was 6), respectively. Conclusion Metamizole sodium and chlorphenamine malcate can be determined respectively by HPLC with the same mobile phase when Sep - Pak C18 microcolumn solid- phase extraction method is used to substitute for the traditional sample pretreatment methods - refluxing, extracting and concentrating, and sodim heptanesulfonate ion - pair reagent in acid condition is selected.

  16. Plasma mitomycin C concentrations determined by HPLC coupled to solid-phase extraction.

    Science.gov (United States)

    Paroni, R; Arcelloni, C; De Vecchi, E; Fermo, I; Mauri, D; Colombo, R

    1997-04-01

    The aim of this study was to set up a method for quantification of plasma mitomycin C (MMC) concentrations during intravesical chemotherapy delivered in the presence of local bladder hyperthermia (HT). In comparison with existing methods, this assay, characterized by relative simplicity and efficiency, resulted in the facilitation of performance with nondedicated instrumentation or nonspecialized staff. Purification from plasma matrix was carried out by solid-phase extraction under vaccuum. The purified drug was then collected directly into the vials of the HPLC autosampler. Chromatographic analysis was performed on a reversed-phase C18 column with water:acetonitrile (85:15 by vol) as the mobile phase and the UV detector set at 365 nm. The use of porfiromycin as internal standard provided a method with good within-day precision (CV 6.0% at 5 micrograms/L, n = 6), linearity (0.5-50 micrograms/L), and specificity. The lower limit of detection (< or = 0.5 microgram/L) proved to be suitable for plasma pharmacokinetics monitoring in two tested patients treated with MMC + HT for superficial bladder cancer. PMID:9105262

  17. Comparison of simultaneous distillation extraction and solid-phase micro-extraction for determination of volatile constituents in tobacco flavor

    Institute of Scientific and Technical Information of China (English)

    ZHONG Ke-jun; WEI Wan-zhi; GUO Fang-qiu; HUANG Lan-fang

    2005-01-01

    The volatile and semi-volatile components in tobacco flavor additives were extracted by both simultaneous distillation extraction and solid-phase micro-extraction. Extraction conditions for solid-phase micro-extraction were optimized with information theory. Then, detection were accomplished by gas chromatography-mass spectrometry. Characteristic of each method was compared. Qualitative analysis and quantitative analysis of 6# tobacco flavor sample were accomplished through both simultaneous distillation extraction and solid-phase micro-extraction. The experimental results show that solid-phase micro-extraction method is the first choice for qualitative analysis and simultaneous distillation extraction is another good selection for quantitative analysis. By means of simultaneous distillation extraction, 20 components are identified, accounting for 92.77% of the total peak areas. Through solid-phase micro-extraction, there are 17 components identified accounting for 91.49% of the total peak areas. The main aromatic components in 6# tobacco flavor sample are propanoic acid, 2-hydroxy-, ethyl ester, menthol and menthyl acetate. The presented method has been successfully used for quality control of tobacco flavor.

  18. Synthesis of Novel Extended Phases of Molecular Solids at High Pressures and Temperatures

    International Nuclear Information System (INIS)

    This study is for in-situ investigation of chemical bonding and molecular structure of low z-elements and simple molecular solids at high pressures and temperatures using 3rd-generation synchrotron x-ray diffraction. To understand the contribution of the empty d-electron orbital of Mg in relation to the formation of molecular solids like MgO, which is one of the important Earth lower mantle materials and MgB2, which has recently been the focus of intense superconducting material research, we have performed double-sided laser heating experiments using a diamond anvil cell (DAC). Understanding the structural stability and the formation of the above Mg-compounds requires studying Mg itself as well as the relevant compounds. BL10XU at the Spring-8 was used to study phase stability and make accurate equation of state (EOS) determinations of Mg coupled with external heating and the double-sided laser heating technique. Monochromatic x-ray at 30 keV (0.4135 (angstrom)) was focused to about 40 (micro)m at the sample and the diffracted x-ray were recorded using a high-resolution image plate (3000 x 3000 pixels with a 0.1 mm resolution per pixel). EOS parameters for hcp and bcc Mg were determined by fitting to a Birch-Murnaghan equation. An isothermal compression of Mg at 300 K up to 100 GPa provides EOS parameters (B0, B0(prime), and V0) comparable for both hcp and bcc phases, which is similar to the cases for hcp and fcc phases measured in cobalt and xenon. Similar EOS parameters for both low and high pressure phases with a very small or no measurable volume discontinuity at the phase transition pressure suggests that the hcp-bcc structural transition of Mg may be driven by a stacking fault due to a shear instability as seen in xenon and cobalt. Compared to the recent estimation determined using a large volume press [1], our B0 is smaller by more than 10% suggesting that the difference may be due to non-hydrostatic conditions. The phase boundary of Mg up to 650 K was

  19. Phase-field Simulation of Microstructural Evolution during Preparation of Semi-solid Metal by Electromagnetic Stirring Method

    Institute of Scientific and Technical Information of China (English)

    Xiaolu YU; Fuguo LI; Yuanchun REN; Miaoquan LI

    2006-01-01

    In the process of preparation of semi-solid metal materials, a variety of factors would influence the preparing time and the morphology of non-dendritic microstructure. The aim of this work is using phase-field method to simulate non-dendritic growth during preparation of Al-4Cu-Mg semi-solid alloy by electromagnetic stirring method (EMS method). Several factors such as the disturbance intensity, anisotropy, the thickness of the interface and the ratio of diffusivity in solid and liquid were considered. It is shown that decreasing the thickness of the interface results in more circular outline of particles, and increasing the diffusivity in solid can reduce degree of microsegregation. The disturbance intensity in the model can be connected with current intensity of stator or magnetic induction density impressed. Simulation results show that the larger the disturbance intensity or magnetic induction density, the more globular morphology the original phase in the matrix.

  20. The kinetics of solid phase epitaxy in As-doped buried amorphous silicon layers

    International Nuclear Information System (INIS)

    The kinetics of dopant-enhanced solid phase epitaxy (SPE) have been measured in buried a-Si layers doped with arsenic. SPE rates were measured over the temperature range 480 - 660 deg C for buried a-Si layers containing ten different As concentrations. In the absence of H-retardation effects, the dopant-enhanced SPE rate is observed to depend linearly on the As concentration over the entire range of concentrations, 1-16 x 1019 cm-3 covered in the study. The Fermi level energy was calculated as a function of doping and find an equation that can provide good fits to the data. The implications of these results for models of the SPE process is discussed

  1. Solid phase microextraction (SPME) sampling under turbulent conditions and for the simultaneous collecting of tracer gases

    Institute of Scientific and Technical Information of China (English)

    Underwood Susanne W.; Jong Edmund C.; Luxbacher Kray D.; Sarver Emily A.; Ripepi Nino S.; McNair Harold M.

    2015-01-01

    Solid phase microextraction (SPME) is a solvent-free method of sample collection. SPME is an appealing method for sample collection because it is designed for the sampling of trace level analytes with short sampling times in a variety of environments. Additionally, SPME can be used to directly deliver a sample to a gas chromatograph (GC) for analysis by means of thermal desorption. In this paper, the performance of SPME under dynamic conditions was investigated. Additionally, the competence of SPME sampling for the simultaneous analysis of multiple trace analytes was also evaluated. This work is discussed in the context of underground mine ventilation surveys but is applicable to any industry in which ventilation circuits must be evaluated. The results of this paper showed that the performance of the 100 lm PDMS SPME fiber was both precise and rapid under dynamic conditions. This SPME fiber was also able to simultaneously collect sulfur hexafluoride (SF6) and perfluoromethylcyclohexane (PMCH) with adequate sensitivity.

  2. Improvements in the vapor-time profile analysis of explosive odorants using solid-phase microextraction.

    Science.gov (United States)

    Young, Mimy; Schantz, Michele; MacCrehan, William

    2016-07-15

    A modified approach for characterization of the vapor-time profile of the headspace odors of explosives was developed using solid-phase microextraction (SPME) incorporating introduction of an externally-sampled internal standard (ESIS) followed by gas chromatography/mass spectrometry (GC/MS) analysis. With this new method, reproducibility of the measurements of 2-ethyl-1-hexanol and cyclohexanone were improved compared to previous work (Hoffman et al., 2009; Arthur and Pawliszyn, 1990) through the use of stable-isotope-labeled internal standards. Exposing the SPME fiber to the ESIS after sampling the target analyte proved to be advantageous, while still correcting for fiber variability and detector drift. For the analysis of high volatility compounds, incorporation of the ESIS using the SPME fiber in the retracted position minimized the subsequent competitive loss of the target analyte, allowing for much longer sampling times. PMID:27286650

  3. Lattice energies of molecular solids from the random phase approximation with singles corrections

    CERN Document Server

    Klimeš, Jiří

    2016-01-01

    We use the random phase approximation (RPA) method with the singles correlation energy contributions to calculate lattice energies of ten molecular solids. While RPA gives too weak binding, underestimating the reference data by $13.7$\\% on average, much improved results are obtained when the singles are included at the GW singles excitations (GWSE) level, with average absolute difference to the reference data of only $3.7$\\%. Consistently with previous results, we find a very good agreement with the reference data for hydrogen bonded systems, while the binding is too weak for systems where dispersion forces dominate. In fact, the overall accuracy of the RPA+GWSE method is similar to an estimated accuracy of the reference data.

  4. Growth research of Sn nanoparticles deposited on Si(0 0 1) substrate by solid phase epitaxy

    International Nuclear Information System (INIS)

    High density of Sn nanoparticles (NPs) had been obtained directly on Si(0 0 1) substrate by solid phase epitaxy. The dependence of the morphology and crystallinity of Sn NPs on Sn coverage, annealing temperature and annealing time was investigated by atomic force microscope (AFM) and X-ray diffraction (XRD). Uniform and densely packed (∼1010 cm-2) Sn NPs were obtained at low Sn coverage, low annealing temperature and short annealing time, respectively. The XRD results showed that, the formed Sn NPs were in the form of crystalline β-Sn, with a distinct orientation of Sn(1 1 0)//Si(0 0 1). The nucleation activation energy of Sn adatoms on Si(0 0 1) surface was estimated to be 0.41 ± 0.05 eV.

  5. A solid phase radioimmunoassay for free triiodothyronine in serum:assay development and validation

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A solid phase radioimmunoassay for free triiodothyroninein serum was developed based on double-antibody coated tubes.The method was turned out to be reliable with good reproducibility,higher sensitivity and easy performance.The measurable range of FT3 in serum was 1.2 to 38pmol/L.The mean coefficients of variationwithin and between assays were 1.79%~3.18% and 4.72%~9.31%,respectively.The FT3 concentrations in euthyroid serum as determined by this methodwere 2.8 to 7.8pmol/L.The FT3 values determined by this new methodcorrelated well with those measured by a commercial radioimmunoassay(r=0.853).

  6. Synthesis and application of cephalexin imprinted polymer for solid phase extraction in milk.

    Science.gov (United States)

    Lata, Kiran; Sharma, Rajan; Naik, Laxmana; Rajput, Y S; Mann, Bimlesh

    2015-10-01

    Molecular imprinted polymer (MIP) against cephalexin was synthesized by co-polymerization of functional monomer, cross-linker, radical initiator, along with target molecule (cephalexin) in a porogenic material. Binding of cephalexin towards prepared MIP was studied in different solvents (water, methanol, 1M NaCl, acetone and acetonitrile) and best binding was observed in methanol. Partition coefficient and selectivity of prepared imprint and non-imprint was also studied. Cross reactivity in terms of binding efficiency was also assessed with other antibiotics. Chromatographic study of MIP was carried out by packing prepared imprint into glass column. MIP was used as matrix in solid phase extraction (SPE) for recovery of cephalexin from spiked milk samples for further estimation by high performance liquid chromatography. No interference was observed from milk components after elution of cephalexin from MIP, indicating selectivity and affinity of MIP. On the other hand, interference was observed in eluate obtained from C18 SPE column. PMID:25872441

  7. Direct solid-phase radioimmunoassay for the detection of Aujeszky's disease antibodies

    International Nuclear Information System (INIS)

    A direct solid-phase radioimmunoassy (dRIA) was developed in order to demonstrate antibodies against Aujeszky's disease virus (ADV) in sera obtained from pigs and rabbits. In the presence of guinea-pig complement the above test is 160-fold to 1500-fold more sensitive than the neutralization test (NT) and 320-fold to 150 000-fold more sensitive than sera obtained from an ADV-infected farm, which were found to be negative in the complement assisted NT. It is possible to test a single dilution of unknown serum by dRIA by comparing same with a standard curve and to make a statement regarding its ADV-specific binding capacity to 125I-labelled ADV antigen. The advantages of dRIA in comparison to the indirect RIA and the advantages and disadvantages with regard to ELISA were discussed. (orig.)

  8. Quantitative determination of geosmin in red beets (Beta vulgaris L.) using headspace solid-phase microextraction.

    Science.gov (United States)

    Lu, Guiping; Fellman, John K; Edwards, Charles G; Mattinson, D Scott; Navazio, John

    2003-02-12

    An improved analytical method for the determination of geosmin in red beets was developed using headspace solid-phase microextraction (HSPME). Volatiles of beet juice were extracted in headspace for 2 h using a polydimethylsiloxane/divinylbenzene fiber, thermally desorbed from the fiber, and analyzed by gas chromatography. The HSPME method was determined to be suitable for geosmin analysis as evidenced by high relative recovery (99.2%), low relative standard deviation (7.48%), and reasonable detection limit (1 microg/kg of beet root tissue). The concentrations of geosmin in four beet cultivars ranged from 9.69 +/- 0.22 to 26.7 +/- 0.27 microg/kg, depending on cultivar. PMID:12568566

  9. Chemiluminescence Determination of Benzoic Acid Using A Solid-Phase Verdigris Reactor

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new chemiluminescence flow system has been developed for sequential determina-tion of benzoic acid based on the reaction of the compound with copper carbonate entrapped in a solid-phase reactor. It was found that the unsaturated complex of Cu(II) and benzoic acid (1:1) has strong catalytic effect on the luminol-H2O2 chemiluminescence reaction. The calibration graph is linear over the range of 0.025 ~ 60 μg/mL of benzoic acid, with a relative standard deviation of less than 3.0 %, and the detection limit is 0.01μg@mL-1. The proposed method was applied to the determination of benzoic acid content in different pharmaceutical formulations.

  10. Determination of available phenolic compounds in soils by liquid chromatography with solid-phase extraction.

    Science.gov (United States)

    Matejícek, David; Klejdus, Borivoj; Kubán, Vlastimil

    2002-01-01

    A fast, selective, and sensitive liquid chromatographic (LC) method was developed for determination of derivatives of benzoic and cinnamic acids (gallic, protocatechuic, 2,3,4-trihydroxybenzoic, 4-hydroxybenzoic, vanillic, caffeic, syringic, 4-coumaric, ferulic, sinapic, benzoic, 2-coumaric, cinnamic acids, and 4-hydroxybenzaldehyde and vanillin) in soil samples. The method for sample pretreatment is based on temperature-controlled extraction with water (pH 5.6) for 60 min. Extracts were preconcentrated and purified by solid-phase extraction on OASIS HLB sorbent, with subsequent separation and quantification of individual substances by LC with UV diode-array detection. Limits of detection (3 signal-to-noise LODs) better than 65 ng/g (dry weight) and recoveries from 88 to 99% were found for each compound at absorbance 280 nm. The method was used for determination of bioavailable phenolic compounds in different soil samples. PMID:12477182

  11. Process for preparation of a solid-phase radioimmunoassay support and use thereof

    International Nuclear Information System (INIS)

    A process is described for the preparation of a support useful in radioimmunoassay chromatographic columns. The process involves the preparation of a chromatographic gel capable of selectively retaining one or more components contained in an antigen-antibody-containing solution. The gel is bound to the appropriate antiserum, then freeze-dried, pulverized and compressed into a tablet. The tablet support swells upon contact with an antigen-antibody-containing solution to conform to the shape of the columns. An example of the application of this support in the radioimmunoassay of thyroid-stimulating hormone is described. This type of support is also particularly useful in second antibody solid phase radioimmunoassays since there is no limit to the size of the antigen to which this technology may be applied. (U.K.)

  12. Reaction Process of Chromium Slag Reduced by Industrial Waste in Solid Phase

    Institute of Scientific and Technical Information of China (English)

    SHI Yu-min; DU Xing-hong; MENG Qing-jia; SONG Shi-wei; SUI Zhi-tong

    2007-01-01

    M, a particular industrial waste, was selected to detoxify chromium slag at a high temperature. The carbon remaining in M reduced Cr (Ⅵ) of Na2CrO4 borne in the chromium slag to Cr (Ⅲ) in the solid phase reaction, and its thermodynamics and kinetics were studied. The reduction process of Na2CrO4 by carbon produced CO, which was endothermic. Under the experimental condition, the apparent activation energy was 4.41 kJ·mol-1, the apparent order of reaction for Na2CrO4 was equal to one, and the partial pressure of CO was only 0.22 Pa at 1 330 ℃.

  13. Gaseous Products of Incense Coil Combustion Extracted by Passive Solid Phase Microextraction Samplers

    Directory of Open Access Journals (Sweden)

    Wen-Hsi Cheng

    2015-06-01

    Full Text Available Burning incense indoors is a common behavior in Southeast Asia. In this investigation, needle trap samplers (NTS, a novel, green analytical technology is used for sampling gaseous combustion by-products from sandalwood incense coils. To extract indoor volatile organic compounds (VOCs, two NTS are prepared, one using 60–80 mesh and the other using 100–120 mesh divinylbenzene (DVB particles packed in 22-gauge stainless steel needles. This work compares extraction efficiency of an NTS and that of a commercially available 100 μm polydimethylsiloxane solid phase microextration (PDMS-SPME fiber sampler. Experimental results indicated that the 100–120 mesh DVB-NTS performed best among all samplers during a 1 h sampling period. The main extracted compounds were toluene, ethylbenzene, propane, chloromethane, 1,3-butadiene, methanol and dichloromethane. The potential use of small badge-sized or pen-sized NTS for the indoor atmosphere and occupational hygiene applications is addressed.

  14. Headspace Solid-Phase Microextraction Analysis of Volatile Components in Phalaenopsis Nobby’s Pacific Sunset

    Directory of Open Access Journals (Sweden)

    Chih-Hsin Yeh

    2014-09-01

    Full Text Available Phalaenopsis is the most important economic crop in the Orchidaceae family. There are currently numerous beautiful and colorful Phalaenopsis flowers, but only a few species of Phalaenopsis have an aroma. This study reports the analysis volatile components present in P. Nobby’s Pacific Sunset by solid-phase microextraction (SPME coupled with gas chromatography (GC and gas chromatography/mass spectrometry (GC-MS. The results show that the optimal extraction conditions were obtained by using a DVB/CAR/PDMS fiber. A total of 31 compounds were identified, with the major compounds being geraniol, linalool and α-farnesene. P. Nobby’s Pacific Sunset had the highest odor concentration from 09:00 to 13:00 on the eighth day of storage. It was also found that in P. Nobby’s Pacific Sunset orchids the dorsal sepals and petals had the highest odor concentrations, whereas the column had the lowest.

  15. Biomonitoring of benzene and toluene in human blood by headspace-solid-phase microextraction

    Energy Technology Data Exchange (ETDEWEB)

    Schimming, E.; Levsen, K. [Fraunhofer-Institut fuer Toxikologie und Aerosolforschung (ITA), Hannover (Germany); Koehme, C.; Schuermann, W. [Medizinische Hochschule Hannover (Germany). Abt. fuer Pneumologie

    1999-01-01

    A simple and rapid method for the determination of benzene and toluene in whole blood by headspace-solid-phase microextraction (HS-SPME) is described. Using SPME fibres coated with 65 {mu}m carboxene/polydimethylsiloxane, limits of quantification (LOQ) of 5 ng/L for benzene and 25 ng/L for toluene are achieved. As a result of its large linear range (i.e. 5-5000 ng/L for benzene) the method is suitable for biomonitoring of both occupationally and environmentally exposed people. The reproducibility of the determination of benzene is {<=} 8%. An interlaboratory comparison demonstrated that the method proposed here compares favorably with existing methods (dynamic headspace, purge and trap). (orig.) With 2 figs., 2 tabs., 10 refs.

  16. Triple phase boundary specific pathway analysis for quantitative characterization of solid oxide cell electrode microstructure

    DEFF Research Database (Denmark)

    Jørgensen, Peter Stanley; Ebbehøj, Søren Lyng; Hauch, Anne

    2015-01-01

    The density and percolation of Triple phase boundary sites are important quantities in analyzing microstructures of solid oxide fuel cell electrodes from tomography data. However, these measures do not provide descriptions of the quality of the TPB sites in terms of the length and radius of the...... pathways through which they can be reached. New methods for performing TPB specific pathway analysis on 3D image data are introduced, analyzing the pathway properties of each TPB site in the electrode structure. The methods seek to provide additional information beyond whether the TPB sites are percolating...... or not by also analyzing the pathway length to the TPB sites and the bottleneck radius of the pathway. We show how these methods can be utilized in quantifying and relating the TPB specific results to cell test data of an electrode reduction protocol study for Ni/Scandia-and-Yttria-doped-Zirconia (Ni...

  17. Facile synthesis of stereoregular carbon fiber precursor polymers by template assisted solid phase polymerization

    Directory of Open Access Journals (Sweden)

    G. Santhana Krishnan

    2012-09-01

    Full Text Available Predominantly isotactic stereoregular polyacrylonitrile copolymers (PAC were prepared by solid phase polymerization techniques using hexagonal crystalline metal salts as template compounds. Stereoregular distributions of the prepared polymer were studied using high resolution 13C nuclear magnetic resonance spectroscopy (13C NMR spectra. The extent of isotacticity was directly determined from the peak intensity of the methine carbon (CH. The triad tacticity from the intensities of methine carbon peaks were examined by statistical methods. It was found that the PAC was predominantly isotactic in stereoregularity, and its sequence distribution obeys Bernoulli statistics. The optimum polymerization conditions ensuring isotactic content over 50% were disclosed experimentally. The chemical composition of PAC was confirmed with 1H NMR data. The obtained polyacrylonitrile copolymers were also characterized for molecular parameters such as viscosity average molecular weight (Mv, number average molecular weight (Mn, weight average molecular weight (Mw and polydispersity index.

  18. Separation and Purification of Sulforaphane from Broccoli by Solid Phase Extraction

    Directory of Open Access Journals (Sweden)

    Kyung Ho Row

    2011-03-01

    Full Text Available A simple solid-phase extraction (SPE method for the determination of sulforaphane in broccoli has been developed. The optimal conditions were found to be use of a silica SPE cartridge, and ethyl acetate and dichloromethane as washing and eluting solvents, respectively, which could eliminate interferences originating from the broccoli matrix. The extracts were sufficiently clean to be directly injected into high-performance liquid chromatography (HPLC for further chromatographic analysis. Good linearity was obtained from 0.05 to 200 μg/mL (r = 0.998 for sulforaphane with the relative standard deviations less than 3.6%. The mean recoveries of sulforaphane from broccoli were more than 90.8% and the detection limit (S/N = 3:1 was 0.02 μg/mL. The SPE method provides a higher yield of sulforaphane from crude extracts compared to conventional liquid-liquid extraction.

  19. Solid-phase extraction and GC/MS confirmation of barbiturates from human urine.

    Science.gov (United States)

    Pocci, R; Dixit, V; Dixit, V M

    1992-01-01

    A highly selective and sensitive procedure has been developed for isolating and identifying barbiturates in human urine. With a new disposable bonded silica gel solid-phase extraction (SPE) column and hexobarbital as an internal standard (IS), amobarbital, butabarbital, pentobarbital, phenobarbital, secobarbital, and methaqualone were selectively isolated from endogenous urine components. Capillary gas chromatography/ion trap mass spectrometry (GC/MS) analysis of the extracts generated a full mass spectrum for the detection, identification, and quantitation of barbiturates. Linear quantitative response curves for the drugs have been generated over a concentration range of 20-500 ng/mL. Overall extraction efficiencies for drugs averaged greater than 90%, and the quantitative response curves exhibited correlation coefficients of 0.996 to 0.999. PMID:1353548

  20. Solid phase extraction of iron and lead in environmental matrices on amberlite xad-1180/pv

    Directory of Open Access Journals (Sweden)

    Mustafa Soylak

    2006-04-01

    Full Text Available A solid phase extraction procedure using Amberlite XAD-1180/Pyrocatechol violet (PV chelating resin for the determination of iron and lead ions in various environmental samples was established. The procedure is based on the sorption of lead(II and iron(III ions onto the resin at pH 9, followed by elution with 1 mol/L HNO3 and determination by flame atomic absorption spectrometry. The influence of alkaline, earth alkaline and some transition metals, as interferents, are discussed. The recoveries for the spiked analytes were greater than 95%. The detection limits for lead and iron by FAAS were 0.37 µg/L and 0.20 µg/L, respectively. Validation of the method described here was performed by using three certified reference materials (SRM 1515 Apple Leaves, SRM 2711 Montana Soil and NRCC-SLRS-4 Riverine Water. The procedure was successfully applied to natural waters and human hair.

  1. Immobilization of Radioactive Rare Earth oxide Waste by Solid Phase Sintering

    International Nuclear Information System (INIS)

    In the pyroprocessing of spent nuclear fuels, LiCl-KCl waste salt containing radioactive rare earth chlorides are generated. The radioactive rare earth oxides are recovered by co-oxidative precipitation of rare earth elements. The powder phase of rare earth oxide waste must be immobilized to produce a monolithic wasteform suitable for storage and ultimate disposal. The immobilization of these waste developed in this study involves a solid state sintering of the waste with host borosilicate glass and zinc titanate based ceramic matrix (ZIT). And the rare-earth monazite which synthesised by reaction of ammonium di-hydrogen phosphate with the rare earth oxides waste, were immobilized with the borosilicate glass. It is shown that the developed ZIT ceramic wasteform is highly resistant the leaching process, high density and thermal conductivity.

  2. Nanometer-sized materials for solid-phase extraction of trace elements.

    Science.gov (United States)

    Hu, Bin; He, Man; Chen, Beibei

    2015-04-01

    This review presents a comprehensive update on the state-of-the-art of nanometer-sized materials in solid-phase extraction (SPE) of trace elements followed by atomic-spectrometry detection. Zero-dimensional nanomaterials (fullerene), one-dimensional nanomaterials (carbon nanotubes, inorganic nanotubes, and nanowires), two-dimensional nanomaterials (nanofibers), and three-dimensional nanomaterials (nanoparticles, mesoporous nanoparticles, magnetic nanoparticles, and dendrimers) for SPE are discussed, with their application for trace-element analysis and their speciation in different matrices. A variety of other novel SPE sorbents, including restricted-access sorbents, ion-imprinted polymers, and metal-organic frameworks, are also discussed, although their applications in trace-element analysis are relatively scarce so far. PMID:25577358

  3. Sol-Gel-Coated Calix[4]arene Fiber for Solid-Phase Microextraction

    Institute of Scientific and Technical Information of China (English)

    LiXiu-juan; XiaoRui-min; LiHai-bing; ZengZhao-rui

    2003-01-01

    5, 11, 17, 23-tetra-tert-butyl-25, 27-diethoxy-26, 28-dihydroxycalix [4] arene/hydroxy-terminated silicone oil coated fiber was first prepared and applied for solid-phase microextraction with sol-gel technology. The properties of the new coating were investigated by analysis of benzene derivatives, polycyclic aromatic hydrocarbons and aromatic amines.The fiber is characterized by good sensitivity and selectivity to these aromatics. The fiber has stable performance at a high temperature of 380℃ and after a long solvent immersing,thus its lifetime is very long. It shows good fiber-to-fiber and batch-to-batch reproducibility. Furthermore, broad linear ranges and low detection limits are also its characteristics.

  4. Determination of trace amount of iron in the PWR secondary water by solid phase spectroscopy (SPS)

    International Nuclear Information System (INIS)

    Solid phase spectroscopy (SPS) that is a potent analysis method of trace iron, based on the direct measurements of the degree of light-absorption by a cation-exchange resin which has adsorbed a Fe(II)-TPTZ complex, was applied to feedwater and moisture separator drain water of Genkai Nuclear Power Station as the alternative procedure to the TPTZ spectrophotometric method and ICP-MS method. The analytical results of real samples obtained by SPS were in good agreement with those by the TPTZ method after 16 times concentration of water samples. It was confirmed that SPS is simple and can make the analysis time short. SPS is evaluated to be applicable to trace analysis of iron in the PWR secondary water. (author)

  5. Determination of phenols in landfill leachate-contaminated groundwaters by solid-phase extraction

    DEFF Research Database (Denmark)

    Ask Reitzel, Lotte; Ledin, Anna

    2002-01-01

    A solid-phase extraction method for phenols in landfill leachates was developed and optimized in order to solve the expected and observed problems associated with an anaerobic matrix containing high concentrations of salts and organic matter. Isolute ENV1 cartridges exhibited the best retention of...... phenols of the four sorbents examined, and was the only cartridge which a 1 L leachate sample could pass through. With the other cartridges, clogging made this impossible. The final method, which included 27 different phenols, gave detection limits of ,0.1 mg/L (drinking water concentration limit for...... identified in leachates from three Danish landfills, ranging in concentration from 0.01 to 29 mg/ L, which is at the lower end of the concentration range usually found for phenols in landfill leachates (sub-mg/L to mg/L).  2002 Elsevier Science B.V. All rights reserved....

  6. Direct Numerical Simulation of Gas-Solid Two-Phase Mixing Layer

    Institute of Scientific and Technical Information of China (English)

    Wenchun LI; Guilin HU; Zhe ZHOU; Jianren FAN; Kefa CEN

    2005-01-01

    In this paper, the spatially evolving of the higher Reynolds numbers gas-solid mixing layer under compressible conditions was investigated by a new direct numerical simulation technology. A high-resolution solver was performed for the gas-phase flow-field, particles with different Stokes numbers were traced by the Lagrangian approach based on one-way coupling. The processes of the vortex rolling up and pairing in the two-dimensional mixing layer were captured precisely. The large-scale structures developed from the initial inflow are characterized by the counter-rotating vortices. The mean velocity and the fluctuation intensities profiles agree well with the experimental data. Particles with smaller Stokes numbers accumulate at the vortex centers due to the smaller aerodynamic response time; particles with moderate Stokes numbers tend to orbit around individual streamwise vortices and in the periphery of paring vortices; particles with larger Stokes numbers disperse less evenly, showing a concentration distribution in the flow field.

  7. Solid phase extraction of uranium(VI) on phosphorus-containing polymer grafted 4-aminoantipyrine

    International Nuclear Information System (INIS)

    Phosphorus-containing polymer grafted 4-aminoantipyrine has been synthesized and used for solid phase extraction of U(VI) prior to its UV-Visible spectrophotometric determination by using arsenazo(III). The adsorbent was characterized by using FT-IR and SEM analysis. The influence of parameters including pH, adsorbent dose, amount of complexing reagent, sample volume and matrix effect have been optimized. The detection limit was determined as 1.4 μg L-1 with preconcentration factor of 30 and RSD of 1.4 %. The accuracy was checked by the analysis of GBW07424 soil and TMDA-64.2 environmental water certified reference materials. The method was applied to natural water and soil samples. (author)

  8. Analysis of a solid-phase radioimmunoassay for antibodies to cytoplasmic antigen fractions of Candida albicans

    International Nuclear Information System (INIS)

    An indirect solid-phase radioimmunoassay (SPRIA) in individual polystyrene microtiter cups has been adapted for measurement of antibody to various cytoplasmic and carbohydrate antigen fractions of Candida albicans. The assay was optimized for sensitivity, precision and linearization of serum dilution curves. The optimized procedure allows computerized measurement of anti-Candida antibodies and can be used for measurement of antibody over a wide concentration range. The procedure obviates variation due to changes in day-to-day counts as a result of isotope decay and end-point antibody dilutions. The assay has been used to demonstrate a Poisson-like distribution of antibody levels in the sera of persons showing no symptoms of candidiasis. The minimum antibody level detectable by the assay is about two orders of magnitude lower than the lowest level found in human serum and 4 orders of magnitude lower than the most sensitive test used hitherto, the hemagglutination test. (Auth.)

  9. Development of solid phase immunoradiometric assay for determination of carcinoembryonic antigen as a tumor marker

    International Nuclear Information System (INIS)

    Development of solid phase coated tube immunoradiometric assay for estimation of carcinoembryonic antigen (CEA) was the aim of the present study. Labeling of CEA was carried out using Ch-T and iodogen as oxidizing agents and 125I. The tracers were used to test the presence of antibodies produced by immunization. Production of polyclonal antibody was carried out through immunization of four mice. After purification step, the tubes were coated by purified polyclonal antibodies. Immunoradiometric that system was performed using the commercial IZOTOP 125I-anti hCEA tracer then the validity studies were carried out. The results show that the local coated tubes made the assay is more than sufficient to fulfill the clinical requirement of CEA as a tumor marker. (author)

  10. Atomic transport during solid-phase epitaxial recrystallization of amorphous germanium

    International Nuclear Information System (INIS)

    The atomic mixing of matrix atoms during solid-phase epitaxy (SPE) is studied by means of isotopically enriched germanium (Ge) multilayer structures that were amorphized by Ge ion implantation up to a depth of 1.5 μm. Recrystallization of the amorphous structure is performed at temperatures between 350 °C and 450 °C. Secondary-ion-mass-spectrometry is used to determine the concentration-depth profiles of the Ge isotope before and after SPE. An upper limit of 0.5 nm is deduced for the displacement length of the Ge matrix atoms by the SPE process. This small displacement length is consistent with theoretical models and atomistic simulations of SPE, indicating that the SPE mechanism consists of bond-switching with nearest-neighbours across the amorphous-crystalline (a/c) interface

  11. A solid-phase dot assay using silica/gold nanoshells

    Directory of Open Access Journals (Sweden)

    Zharov Vladimir

    2006-01-01

    Full Text Available AbstractWe report on the first application of silica-gold nanoshells to a solid-phase dot immunoassay. The assay principle is based on staining of a drop (1 µl analyte on a nitrocellulose membrane strip by using silica/gold nanoshells conjugated with biospecific probing molecules. Experimental example is human IgG (hIgG, target molecules and protein A (probing molecules. For usual 15-nm colloidal gold conjugates, the minimal detectable amount of hIgG is about 4 ng. By contrast, for nanoshell conjugates (silica core diameter of 70 nm and gold outer diameter of 100 nm we have found significant increase in detection sensitivity and the minimal detectable amount of hIgG is about 0.5 ng. This finding is explained by the difference in the monolayer particle extinction.

  12. Simple solid-phase radioimmunoassay for human leukemia-associated cell membrane antigens

    International Nuclear Information System (INIS)

    In the present study, a simple solid-phase radioimmunoassay was developed to determine detergent-extracted human leukemia-associated cell membrane antigens. In the assay, 96-well microtiter plates are coated with human leukemia cell membrane antigens containing a T cell leukemia or a non-T cell leukemia antigen in the presence of a detergent, and treated with 1.6% bovine serum albumin solution. The coated antigens were reacted with an appropriate murine monoclonal antibody (mAb). The bound mAb is determined by a second reaction with 125I-labeled F(ab')2 of goat anti-mouse Ig. The best antigen dose-dependent antibody binding results were obtained using the plates coated with antigens in the presence of taurocholate. In addition, the usefulness of the present assay with taurocholate during the purification of the antigens was demonstrated. (Auth.)

  13. A novel silver-coated solid-phase microextraction metal fiber based on electroless plating technique.

    Science.gov (United States)

    Feng, Juanjuan; Sun, Min; Li, Jubai; Liu, Xia; Jiang, Shengxiang

    2011-09-01

    A novel silver-coated solid-phase microextraction fiber was prepared based on electroless plating technique. Good extraction performance of the fiber for model compounds including phthalate esters (dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate and diallyl phthalate) and polycyclic aromatic hydrocarbons (naphthalene, fluorene, phenanthrene, fluoranthene) in aqueous solution was obtained. Under the optimized conditions (extraction temperature, extraction time, ionic strength and desorption temperature), the proposed SPME-GC method showed wide linear ranges with correlation coefficients (R(2)) ranging from 0.9745 to 0.9984. The limits of detection were at the range of 0.02 to 0.1 μg L(-1). Single fiber repeatability and fiber-to-fiber reproducibility as well as stability to acid, alkali and high temperature were studied and the results were all satisfactory. The method was applied successfully to the aqueous extracts of disposable paper cup and instant noodle barrel. Several kinds of analytes were detected and quantified. PMID:21801885

  14. A simple and safe method for single HLA-antigen-typing by a solid phase assay.

    Science.gov (United States)

    Häcker-Shahin, B; Giannitsis, D J

    1991-01-01

    A rapid solid phase assay for detection of single HLA-antigens on platelets was developed. The platelets were attached to the surface of polystyrene microtitre plate wells by means of a sodium carbonate buffer and centrifugation. Uncovered areas were blocked by a gelatin blocking buffer. After incubation with commercially available anti-HLA-sera the bound anti-HLA-specific antibodies directed against HLA-antigens present on the platelets were made visible by anti-IgG-coated indicator red cells and a brief centrifugation. A positive result, meaning the presence of an HLA-antigen, was indicated by a slight red cell adherence over the reaction surface. In the absence of the HLA-antigen no binding occurred and the indicator red cells formed a small red disc-like pellet. PMID:1954783

  15. Emergence of a Metallic Quantum Solid Phase in a Rydberg-Dressed Fermi Gas

    Science.gov (United States)

    Li, Wei-Han; Hsieh, Tzu-Chi; Mou, Chung-Yu; Wang, Daw-Wei

    2016-07-01

    We examine possible low-temperature phases of a repulsively Rydberg-dressed Fermi gas in a three-dimensional free space. It is shown that the collective density excitations develop a roton minimum, which is softened at a wave vector smaller than the Fermi wave vector when the particle density is above a critical value. The mean field calculation shows that, unlike the insulating density wave states often observed in conventional condensed matters, a self-assembled metallic density wave state emerges at low temperatures. In particular, the density wave state supports a Fermi surface and a body-centered-cubic crystal order at the same time with the estimated critical temperature being about one tenth of the noninteracting Fermi energy. Our results suggest the emergence of a fermionic quantum solid that should be observable in the current experimental setup.

  16. Solid-phase peptide synthesis: from standard procedures to the synthesis of difficult sequences.

    Science.gov (United States)

    Coin, Irene; Beyermann, Michael; Bienert, Michael

    2007-01-01

    This protocol for solid-phase peptide synthesis (SPPS) is based on the widely used Fmoc/tBu strategy, activation of the carboxyl groups by aminium-derived coupling reagents and use of PEG-modified polystyrene resins. A standard protocol is described, which was successfully applied in our lab for the synthesis of the corticotropin-releasing factor (CRF), >400 CRF analogs and a countless number of other peptides. The 41-mer peptide CRF is obtained within approximately 80 working hours. To achieve the so-called difficult sequences, special techniques have to be applied in order to reduce aggregation of the growing peptide chain, which is the main cause of failure for peptide chemosynthesis. Exemplary application of depsipeptide and pseudoproline units is shown for synthesizing an extremely difficult sequence, the Asn(15) analog of the WW domain FBP28, which is impossible to obtain using the standard protocol. PMID:18079725

  17. Solid-phase radioimmunoassay for the measurement of surface antigens expressed on intact lymphocytes

    International Nuclear Information System (INIS)

    A solid-phase radioimmunoassay was developed for the measurement of lymphocyte surface antigens. The assay was performed in microplates, using cells that were initially fixed to the wells by air drying. The method was used for the measurement of Thy-1, Lyt-1,2,3, IL-2-R, H-2Kb and DR antigens on the surface of mouse thymus, spleen and bone marrow cells, mouse cell lines CTLL, EL-4 and DA-1 and human thymocytes and consisted of sequential incubations with rat or mouse monoclonal antibodies directed against the above antigens, rabbit anti-rat or goat anti-mouse IgG and 125I-protein A. The assay permits the processing of large numbers of samples, is easy to perform, reliable and highly specific. (Auth.)

  18. A new method for measuring antibody using radiolabeled protein A in a solid-phase radioimmunoassay

    International Nuclear Information System (INIS)

    A micro solid-phase radioimmunoassay was developed which utilizes radiolabeled staphylococcal Protein A ([125I] Protein A) in place of radiolabeled anti-immunoglobulin ([125I]anti-IgG) for the measurement of antibody. For the assay, antigen is adsorbed to the wells of a microtiter plate followed by dilutions of serum and [125I]-Protein A in subsequent steps. It was found that this assay can be used to measure antibody (Ab) against a variety of antigens in human and rabbit but not goat immune serum. Binding of [125I]-Protein A and [125I]anti-IgG to human and rabbit IgG was comparable. It was possible to quantify this amount of Ab in human serum by reference to immune rabbit serum. The sensitivity of this assay for rabbit antibody was 1 ng/ml. (Auth.)

  19. Solid-phase radioimmunoassay for the measurement of surface antigens expressed on intact lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Savion, S.; Sharabi, Y.; Shoham, J.

    1987-02-26

    A solid-phase radioimmunoassay was developed for the measurement of lymphocyte surface antigens. The assay was performed in microplates, using cells that were initially fixed to the wells by air drying. The method was used for the measurement of Thy-1, Lyt-1,2,3, IL-2-R, H-2K/sup b/ and DR antigens on the surface of mouse thymus, spleen and bone marrow cells, mouse cell lines CTLL, EL-4 and DA-1 and human thymocytes and consisted of sequential incubations with rat or mouse monoclonal antibodies directed against the above antigens, rabbit anti-rat or goat anti-mouse IgG and /sup 125/I-protein A. The assay permits the processing of large numbers of samples, is easy to perform, reliable and highly specific. 13 refs.; 10 figs.

  20. A numerical investigation into the solids phase chromatography using a combined continuous and discrete approach

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Solids phase chromatography for particle classification is based on different retention times of particles with different properties when they are elutriated through a confined geometry.This work aims at a fundamental understanding of such a technology by using the combined continuous and discrete method.A packed bed is employed as the model confined geometry.The numerical method is compared first with experimental observations,followed by a parametric analysis of the effects on the flow hydrodynamics and solids behaviour of various parameters including the number of injected particles,the superficial gas velocity,the contact stiffness and the diameter ratio of the packed column to the packed particles.The results show that the modelling captures some important features of the flow of an injected pulse of fine particles in a packed bed. An increase in the number of injected particles or the superficial gas velocity reduces the retention time,whereas the contact stiffness does not show much effect over the range of 5×102 to5×104 N/m.It is also found that the effect on the retention time of the diameter ratio of the packed column to the packed particles seems complex showing a non-monotonous dependence.

  1. Determination of Atrazine, Acetochlor, Clomazone, Pendimethalin and Oxyfluorfen in Soil by a Solid Phase Microextraction Method

    Directory of Open Access Journals (Sweden)

    Rada Đurović

    2008-01-01

    Full Text Available A solid phase microextraction (SPME method for simultaneous determination of atrazine, acetochlor, clomazone, pendimethalin and oxyfluorfen in soil samples was developed. The method is based on a combination of conventional liquid-solid procedure and a following SPME determination of the selected pesticides. Initially, various microextraction conditions, such as the fibre type, desorption temperature and time, extraction time and NaCl content, were investigated and optimized. Then, extraction efficiencies of severalsolvents (water, hexane, acetonitrile, acetone and methanol and the optimum number of extraction steps within the sample preparation step were optimized. According to the results obtained in these two sets of experiments, two successive extractions with methanol as the extraction solvent were the optimal sample preparation procedure, while the following conditions were found to be most efficient for SPME measurements: 100 μm PDMS fibre, desorption for 7 min at 2700C, 30 min extraction time and 5% NaCl content (w/v. Detection and quantification were done by gas chromatography-mass spectrometry(GC/MS. Relative standard deviation (RSD values for multiple analysis of soil samples fortified at 30 μg/kg of each pesticide were below 19%. Limits of detection (LOD for all the compounds studied were less than 2 μg/kg.

  2. Methylation and Release of Mercury From the Solid Phase. What Comes First?

    Science.gov (United States)

    Regnell, O.

    2004-05-01

    It is a well-known fact that methylation leads to a dramatic increase in the bioavailability of mercury (Hg). All recent observations support the notion that Hg methylation is almost exclusively an anaerobic process. According to the reigning paradigm, methylation of Hg takes place in the cytoplasm of anaerobic bacteria, notably sulfate-reducing bacteria. It is believed that certain forms of inorganic divalent Hg (Hg(II)), can readily diffuse across the cell membrane. In addition, a recent study suggested that active uptake may occur when Hg is bound to low weight organic molecules. In the cytoplasm, cobalamin-dependent biochemical pathways, designed to methylate substrates other than Hg(II), are held responsible for the methylation of Hg(II). However, recent results from studies in a Swedish wetland (within the project "Svartsjoprojektet", aiming at understanding Hg dynamics in a Hg-polluted river-lake system) have led us to question whether Hg methylation does occur exclusively within cells. A provocative interpretation of our results is that methylation preceded the release of Hg from the solid phase, e.g. that Hg(II) sorbed to solid surfaces was methylated and subsequently released as methyl Hg to the sulfidic water. I will discuss this possibility in light of existing evidence that Hg methylation is an intra cellular process.

  3. Study on solid-liquid two-phase flow on PWR sump clogging issue

    International Nuclear Information System (INIS)

    It has been concerned that there is a possibility of sump screens clogging in pressurized water reactors (PWRs) in case of a loss-of-coolant accident (LOCA), because two-phase jet flow would strip off thermal insulation materials from nearby piping and wash down generated debris to sump screens or strainers. It is necessary for evaluation of electiveness of sump screens to estimate amount of debris transport from break position to sump screens. Debris transport is plant dependent and has plant specific uncertainty. In general, conservative logic trees have been applied to determine debris transport rates. Therefore, realistic debris transport evaluation that could apply to every LOCA situation would be needed for rational resolution of this generic safety issue. The purpose of present study is to develop and to apply a debris transport evaluation model to this issue. We have developed a solid-liquid multiphase model which enables to simulate debris transport, settling, and re-suspension caused by turbulence. The model treats different size of solid particles which are smaller than uniform sized liquid particles. This contributed to reducing calculation cost. The model has been implemented into a code based on the moving particle semi-implicit (MPS) method with a turbulence model. Several open channel hydraulic experiments with fibrous debris have been conducted. The code was verified by the comparison of the results of the code with experiments. Debris transport analysis was applied to a full scale PWR containment vessel floor and several features were turned out. (author)

  4. Study on solid-liquid two-phase flow on PWR sump clogging issue

    International Nuclear Information System (INIS)

    It has been a concern that sump screen clogging would occur in pressurized water reactors (PWRs) in the case of a loss-of-coolant accident (LOCA), because two-phase jet flow would strip off thermal insulation from the piping and wash down the broken and fragmented debris to sump screens. It is necessary for the evaluation of the effectiveness of sump screens to estimate the amount of transported debris from a break position to sumps. In general, conservative logic trees have been used to determine debris transport rates. Realistic debris transport evaluation is useful for considering measures and rational decision making in licensing. The purpose of this study is to develop a debris transport evaluation model and to apply the model to this issue. We developed a solid-liquid multiphase model that is capable of simulating debris transport, settling, and resuspension. The model is able to treat solid particles of different sizes, which are smaller than uniform-sized liquid particles. This approach contributes to reducing the calculation cost in a large-scale simulation. The model and a turbulence model were implemented into a code based on the moving particle semi-implicit (MPS) method. Several open-channel hydraulic experiments with fibrous debris were conducted. The code named SANSUI 2.0 was validated by the comparison of the analytical results with experiments. This method was applied to the debris transport analysis of a full-scale PWR containment vessel floor, and the debris transport behavior was evaluated. (author)

  5. IMMOBILIZATION OF RADIONUCLIDES IN THE HANFORD VADOSE ZONE BY INCORPORATION IN SOLID PHASES

    Energy Technology Data Exchange (ETDEWEB)

    Traina, Samuel J.; Grandinetti, Philip; Brown Jr., Gordon E. Ainsworth, Calvin C.; Szecsody, Jim E.

    2001-06-01

    Specific objectives are to investigate (1) the effect of aging on the stability of sorption complexes on Al-oxide and Al-oxyhydroxide surfaces formed from neutralization and homogeneous nucleation of alkaline aluminate solutions; (2) the sorption/coprecipitation of these elements in solids formed from reaction of alkaline aluminate solutions with simple systems of representative minerals and mineral coatings found in the soils and sediments underlying the Hanford Tank Farm (e.g., quartz, feldspars, biotite, muscovite, chlorite,clay mineral, augite, hornblende, ilmenite, magnetite, hematite, Fe(III)- oxyhydroxides, and Mn(IV)-(hydr)oxides); and (3) the sorption/coprecipitation of these elements in solids formed from reaction of alkaline aluminate solutions with soil and sediment samples obtained from the Hanford site. (4) To couple these laboratory studies to precipitation processes occurring in the Hanford vadose zone beneath the Tank Farm, we also propose to characterize the particle coatings and precipitate phases in core samples from this zone. These investigations will utilize X-ray Absorption Fine Structure (XAFS) spectroscopy, vibrational spectroscopy, NMR spectroscopy, electron and X-ray microprobe analyses, transmission electron microscopy, X-ray photoelectron spectroscopy, and other characterization studies of the speciation and spatial distribution of the these ions in several model systems chosen to simulate the natural systems.

  6. Determination of Scopolamine in Human Saliva Using Solid Phase Extraction and LC/MS/MS

    Science.gov (United States)

    Wang, Zuwei; Vaksman, Zalman; Boyd, Jason; Putcha, Lakshmi

    2007-01-01

    Purpose: Scopolamine is the preferred treatment for motion sickness during space flight because of its quick onset of action, short half-life and favorable side-effect profile. The dose administered depends on the mode of administration and usually ranges between 0.1 and 0.8 mg. Such small doses make it difficult to detect concentrations of scopolamine in biological fluids by using conventional HPLC methods. To measure scopolamine in saliva and thereby to evaluate the pharmacokinetics of scopolamine, we developed an LC/MS/MS method using off-line solid phase extraction. Method: Samples (0.5mL) were loaded onto Waters Oasis HLB co-polymer cartridges (10 mg, 1 mL) and eluted with 0.5 mL methanol without evaporation and reconstitution. HPLC separation of the eluted sample was performed using an Agilent Zorbax SB-CN column (50 x 2.1 mm) at a flow rate of 0.2 mL/min for 4 minutes. The mobile phase for separation was 90:10 (v/v) methanol: ammonium acetate (2 mM) in water, pH 5.0 +/- 0.1. Concentrations of scopolamine were determined using a Micromass Quattro Micro(TM) mass spectrometer with electrospray ionization (ESI). ESI mass spectra were acquired in positive ion mode with multiple reaction monitoring for the determination of scopolamine m/z = 304.2 yields 138.1 and internal standard (IS) hyoscyamine m/z = 290.2 yields 124.1. Results: The method is rapid, reproducible, specific and has the following parameters: scopolamine and the IS are eluted at 1.7 and 3.2 min respectively. The linear range is 50-5000 pg/mL for scopolamine in saliva with correlation coefficients > 0.99 with a CV < 0.5 %. The intra-day and inter-day CVs are < 15 % for quality control samples with concentrations of 75, 300, 750 and 3000 pg/mL of scopolamine in human saliva. Conclusion: Solid phase extraction allows more rapid sample preparation and greater precision than liquid extraction. Furthermore, we increased the sensitivity and specificity by adjusting the LC mobile phase and using an MS

  7. Cu Binding to Iron Oxide-Organic Matter Coprecipitates in Solid and Dissolved Phases

    Science.gov (United States)

    Vadas, T. M.; Koenigsmark, F.

    2015-12-01

    Recent studies indicate that Cu is released from wetlands following storm events. Assymetrical field flow field fractionation (AF4) analyses as well as total and dissolved metal concentration measurements suggest iron oxide-organic matter complexes control Cu retention and release. Coprecipitation products of Fe oxide and organic matter were prepared under conditions similar to the wetland to assess Cu partitioning to and availability from solid phases that settle from solution as well as phases remaining suspended. Cu coprecipitation and sorption to organomineral precipitation solids formed at different Fe:organic carbon (OC) ratios were compared for net Cu removal and extractability. As more humic acid was present during precipitation of Fe, TEM images indicated smaller Fe oxide particles formed within an organic matrix as expected. In coprecipitation reactions, as the ratio of Fe:OC decreased, more Cu was removed from solution at pH 5.5 and below. However, in sorption reactions, there was an inhibition of Cu removal at low OC concentrations. As the pH increased from 5.5 to 7 and as solution phase OC concentration increased, more Cu remained dissolved in both coprecipitation and sorption reactions. The addition of Ca2+, glycine, histidine and citric acid or lowering the pH resulted in more extractable Cu from the coprecipitation compared with the sorption reactions. The variations in Cu extraction were likely due to a combination of a more amorphous structure in CPT products, and the relative abundance of available Fe oxide or OC binding sites. Suspended Fe oxide-organic matter coprecipitates were assessed using AF4 coupled to online TOC analysis and ICP-MS. In laboratory prepared samples, Cu was observed in a mixture of small 1-5 nm colloids of Fe oxide-organic matter precipitates, but the majority was observed in larger organic matter colloids and were not UV absorbing, suggesting more aliphatic carbon materials. In field samples, up to 60% of the dissolved Cu

  8. Principles and applications of colorimetric solid-phase extraction with negligible depletion

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Neil C. [Institute for Combinatorial Discovery, Ames Laboratory-U.S. Department of Energy, Department of Chemistry, Iowa State University, Ames, IA 50011 (United States); Porter, Marc D. [Institute for Combinatorial Discovery, Ames Laboratory-U.S. Department of Energy, Department of Chemistry, Iowa State University, Ames, IA 50011 (United States)]. E-mail: mporter@porter1.ameslab.gov; Fritz, James S. [Institute for Combinatorial Discovery, Ames Laboratory-U.S. Department of Energy, Department of Chemistry, Iowa State University, Ames, IA 50011 (United States)

    2006-02-03

    Colorimetric solid-phase extraction (C-SPE) is an integrated technique in which an analyte is selectively concentrated onto a disk and then quantitated by diffuse reflectance spectroscopy. This paper describes the results of an investigation that applies the concept of negligible depletion (ND) to C-SPE, representing the first application of ND concepts to solid-phase extractions. The approach relies on passing the minimal volume of sample through the disk required to reach an equilibrium in which the concentration of analyte in the sample entering and exiting the disk are equal. At this point, the amount of analyte extracted by the disk is proportional to the sample concentration but is independent of the sample volume passed through the disk. With this new method, called C-SPE/ND, the precise measurement of sample volume is no longer necessary. The work herein details the general principles of this new methodology, and validates its basic tenets in an investigation of the extraction of the organic dye methyl violet. The analytical capabilities of C-SPE/ND are then demonstrated by its application to measurements of iodine. Iodine is a biocide increasingly used as a simple and effective disinfectant for water in locations where municipal water treatment systems are potentially compromised. Thus, the ability to operate C-SPE in an ND mode notably enhances the broad-based utility of this methodology as a reliable and an easy-to-use analysis tool for water quality assessments. Since iodine is also the biocide used on NASAs Space Shuttle, C-SPE/ND has the potential to overcome problems associated with the removal of air bubbles entrapped in a water sample in the microgravity environment encountered in space exploration. Extensions of C-SPE/ND to facile determinations of other water quality parameters with respect to both earth- and space-based needs are briefly discussed.

  9. Theoretical and infrared investigation of 2-acetylpyridine isolated in solid nitrogen and in neat condensed phases

    Science.gov (United States)

    Kuş, Nihal

    2016-07-01

    The geometries of the two conformers of 2-acetylpyridine (2AP) were optimized at the DFT/B3LYP/6-311++G(d,p) level of approximation, and their relative energy and interconversion barrier evaluated. Both conformers were found to belong to the Cs symmetry point group, with conformer cis (with the methyl group and the ring nitrogen atom located in the same side of the molecule) being considerably stabilized over the trans form. The cis conformer exhibits stabilizing interactions between the ortho ring hydrogen atom and the carbonyl oxygen, as well as between the methyl out-of-the-plane hydrogen atoms and the ring nitrogen atom. In the less stable trans conformer (ΔE(trans-cis) = 26.3 kJ mol-1) these stabilizing interactions are replaced by repulsive interactions between the oxygen and nitrogen lone electron pairs and between the ring ortho and methyl out-of-the-plane hydrogen atoms. The energy barrier between the two conformers amounts to 30.7 kJ mol-1 in the cis → trans direction (4.4 kJ mol-1 in the reverse direction). In agreement with the theoretical data, in a cryogenic N2 matrix prepared from the room temperature 2AP gas phase, only the most stable cis conformer was observed. The IR spectra of 2AP isolated in solid N2, and those for the low temperature amorphous and crystalline neat solid states of the compound were recorded, and correlations between the spectroscopic data and the strength and nature of the dominant intermolecular interactions in 2AP neat condensed phases were evaluated. The analysis of the experimental vibrational data was supported by theoretical calculation of harmonic and anharmonic frequencies and IR intensities obtained at the DFT/B3LYP/6-311++G(d,p) level of theory.

  10. Improved resins and novel materials and methods for solid phase extraction and high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Freeze, R.

    1997-10-08

    Solid-phase extraction (SPE) has grown to be one of the most widely used methods for isolation and preconcentration of a vast range of compounds from aqueous solutions. By modifying polymeric SPE resins with chelating functional groups, the selective uptake of metals was accomplished. The resin, along with adsorbed metals, was vaporized in the ICP and detection of the metals was then possible using either mass or emission spectroscopy. Drug analyses in biological fluids have received heightened attention as drug testing is on the increase both in sports and in the work environment. By using a direct-injection technique, biological fluids can be injected directly into the liquid chromatographic system with no pretreatment. A new surfactant, a sulfonated form of Brij-30 (Brij-S) is shown to prevent the uptake of serum proteins on commercial HPLC columns by forming a thin coating on the silica C18 surface. Excellent separations of eight or more drugs with a wide range of retention times were obtained. The separations had sharper peaks and lower retention times than similar separations performed with the surfactant sodium dodecylsulfate (SDS). Quantitative recovery of a number of drugs with limits of detection near 1 ppm with a 5 {micro}l injection volume were obtained. Finally, a method for solid-phase extraction in a syringe is introduced. The system greatly reduced the volume of solvent required to elute adsorbed analytes from the SPE bed while providing a semi-automated setup. SPE in a syringe consists of a very small bed of resin-loaded membrane packed into a GC or HPLC syringe. After extraction, elution was performed with just a few {micro}l of solvent. This small elution volume allowed injection of the eluent directly from the syringe into the chromatographic system, eliminating the handling problems associated with such small volumes.

  11. Aniline-silica nanocomposite as a novel solid phase microextraction fiber coating.

    Science.gov (United States)

    Bagheri, Habib; Roostaie, Ali

    2012-05-18

    A new unbreakable solid phase microextraction (SPME) fiber coating based on aniline-silica nanocomposite was electrodeposited on a stainless steel wire. The electropolymerization process was carried out at a constant deposition potential, applied to the corresponding aqueous electrolyte containing aniline and silica nanoparticles. The scanning electron microscopy (SEM) images showed the non-smooth and the porous surface structure of the prepared nanocomposite. The applicability of the new fiber coating was examined by headspace-solid phase microextraction (HS-SPME) of some environmentally important polycyclic aromatic hydrocarbons (PAHs), as model compounds, from aqueous samples. Subsequently, the extracted analytes were transferred into a gas chromatography (GC) by thermal desorption. Parameters affecting the synthesizing and extraction processes including the voltage of power supply, the weight ratio of components, the time of electrodeposition, extraction time and temperature, the ionic strength, and desorption temperature and time were optimized. Eventually, the developed method was validated by gas chromatography-mass spectrometry (GC-MS). At the optimum conditions, the relative standard deviation (%RSD) values for a double distilled water spiked with the selected PAHs at 40 ng L(-1) were 6-13% (n=3) while the limit of detection (LOD) results were between 1 and 3 ng L(-1). The calibration graphs were linear in the concentration range from 20 to 4000 ng L(-1) (R(2)>0.995). Finally the developed method was applied to the analysis of Kalan dam, rain and tap water samples and the relative recovery values were found to be in the range of 76-109%, under optimized conditions. In addition, the synthesis of the nanocomposite coating was carried out conveniently while it is rather inexpensive, easy, simple, rapid and highly durable and can be used frequently. PMID:22498354

  12. Molecularly imprinted solid-phase extraction of glutathione from urine samples

    Energy Technology Data Exchange (ETDEWEB)

    Song, Renyuan, E-mail: songrenyuan0726@163.com; Hu, Xiaoling; Guan, Ping; Li, Ji; Zhao, Na; Wang, Qiaoli

    2014-11-01

    Molecularly imprinted polymer (MIP) particles for glutathione were synthesized through iniferter-controlled living radical precipitation polymerization (IRPP) under ultraviolet radiation at ambient temperature. Static adsorption, solid-phase extraction, and high-performance liquid chromatography were carried out to evaluate the adsorption properties and selective recognition characteristics of the polymers for glutathione and its structural analogs. The obtained IRPP-MIP particles exhibited a regularly spherical shape, rapid binding kinetics, high imprinting factor, and high selectivity compared with the MIP particles prepared using traditional free-radical precipitation polymerization. The selective separation and enrichment of glutathione from the mixture of glycyl-glycine and glutathione disulfide could be achieved on the IRPP-MIP cartridge. The recoveries of glutathione, glycyl-glycine, and glutathione disulfide were 95.6% ± 3.65%, 29.5% ± 1.26%, and 49.9% ± 1.71%, respectively. The detection limit (S/N = 3) of glutathione was 0.5 mg·L{sup −1}. The relative standard deviations (RSDs) for 10 replicate detections of 50 mg·L{sup −1} of glutathione were 5.76%, and the linear range of the calibration curve was 0.5 mg·L{sup −1} to 200 mg·L{sup −1} under optimized conditions. The proposed approach was successfully applied to determine glutathione in spiked human urine samples with recoveries of 90.24% to 96.20% and RSDs of 0.48% to 5.67%. - Highlights: • Imprinted polymer particles were prepared by IRPP at ambient temperature. • High imprinting factor, high selectivity, and rapid binding kinetics were achieved. • Selective solid-phase extraction of glutathione from human urine samples.

  13. An interior needle electropolymerized pyrrole-based coating for headspace solid-phase dynamic extraction

    International Nuclear Information System (INIS)

    A headspace solid-phase dynamic extraction (HS-SPDE) technique was developed by the use of polypyrrole (PPy) sorbent, electropolymerized inside the surface of a needle, as a possible alternative to solid-phase microextraction (SPME). Thermal desorption was subsequently, employed to transfer the extracted analytes into the injection port of a gas chromatography-mass spectrometry (GC-MS). The PPy sorbent including polypyrrole-dodecyl sulfate (PPy-DS) was deposited on the interior surface of a stainless steel needle from the corresponding aqueous electrolyte by applying a constant deposition potential. The homogeneity and the porous surface structure of the coating were examined using the scanning electron microscopy (SEM). The developed method was applied to the trace level extraction of some polycyclic aromatic hydrocarbons (PAHs) from aqueous sample. In order to enhance the extraction efficiency and increase the partition coefficient of analytes, the stainless steel needle was cooled at 5 deg. C, while the sample solution was kept at 80 deg. C. Optimization of influential experimental conditions including the voltage of power supply, the time of PPy electrodeposition, the extraction temperature, the ionic strength and the extraction time were also investigated. The detection limits of the method under optimized conditions were in the range of 0.002-0.01 ng mL-1. The relative standard deviations (R.S.D.) at a concentration level of 0.1 ng mL-1 were obtained between 7.54 and 11.4% (n = 6). The calibration curves of PAHs showed linearity in the range of 0.01-10 ng mL-1. The proposed method was successfully applied to the extraction of some selected PAHs from real-life water samples and the relative recoveries were higher than 90% for all the analytes

  14. An interior needle electropolymerized pyrrole-based coating for headspace solid-phase dynamic extraction

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, Habib [Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of)], E-mail: bagheri@sharif.edu; Babanezhad, Esmaeil; Khalilian, Faezeh [Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of)

    2009-02-23

    A headspace solid-phase dynamic extraction (HS-SPDE) technique was developed by the use of polypyrrole (PPy) sorbent, electropolymerized inside the surface of a needle, as a possible alternative to solid-phase microextraction (SPME). Thermal desorption was subsequently, employed to transfer the extracted analytes into the injection port of a gas chromatography-mass spectrometry (GC-MS). The PPy sorbent including polypyrrole-dodecyl sulfate (PPy-DS) was deposited on the interior surface of a stainless steel needle from the corresponding aqueous electrolyte by applying a constant deposition potential. The homogeneity and the porous surface structure of the coating were examined using the scanning electron microscopy (SEM). The developed method was applied to the trace level extraction of some polycyclic aromatic hydrocarbons (PAHs) from aqueous sample. In order to enhance the extraction efficiency and increase the partition coefficient of analytes, the stainless steel needle was cooled at 5 deg. C, while the sample solution was kept at 80 deg. C. Optimization of influential experimental conditions including the voltage of power supply, the time of PPy electrodeposition, the extraction temperature, the ionic strength and the extraction time were also investigated. The detection limits of the method under optimized conditions were in the range of 0.002-0.01 ng mL{sup -1}. The relative standard deviations (R.S.D.) at a concentration level of 0.1 ng mL{sup -1} were obtained between 7.54 and 11.4% (n = 6). The calibration curves of PAHs showed linearity in the range of 0.01-10 ng mL{sup -1}. The proposed method was successfully applied to the extraction of some selected PAHs from real-life water samples and the relative recoveries were higher than 90% for all the analytes.

  15. Evaluation of single-walled carbon nanohorns as sorbent in dispersive micro solid-phase extraction

    International Nuclear Information System (INIS)

    Highlights: ► The potential of single walled carbon nanohorns in dispersive solid phase microextraction has been evaluated. ► The method was characterized for the extraction of PAHs from waters. ► Single walled carbon nanohorns were better extractant than carbon nanotubes and carbon nanocones. ► The limits of detection were adequate for the target analytes in environmental waters. - Abstract: A new dispersive micro solid-phase extraction method which uses single-walled carbon nanohorns (SWNHs) as sorbent is proposed. The procedure combines the excellent sorbent properties of the nanoparticles with the efficiency of the dispersion of the material in the sample matrix. Under these conditions, the interaction with the analytes is maximized. The determination of polycyclic aromatic hydrocarbons was selected as model analytical problem. Two dispersion strategies were evaluated, being the functionalization via microwave irradiation better than the use of a surfactant. The extraction was accomplished by adding 1 mL of oxidized SWHNs (o-SWNHs) dispersion to 10 mL of water sample. After extraction, the mixture was passed through a disposable Nylon filter were the nanoparticles enriched with the PAHs were retained. The elution was carried out with 100 μL of hexane. The limits of detection achieved were between 30 and 60 ng L−1 with a precision (as repeatability) better than 12.5%. The recoveries obtained for the analytes in three different water samples were acceptable in all instances. The performance of o-SWNHs was favourably compared with that provided by carboxylated single-walled carbon nanotubes and thermally treated carbon nanocones.

  16. A metal organic framework-polyaniline nanocomposite as a fiber coating for solid phase microextraction.

    Science.gov (United States)

    Bagheri, Habib; Javanmardi, Hasan; Abbasi, Alireza; Banihashemi, Solmaz

    2016-01-29

    A metal organic framework-polyaniline (MOF/PANI) nanocomposite was electrodeposited on a stainless steel wire and used as a solid phase microextraction (SPME) fiber coating. The electropolymerization process was carried out under a constant deposition potential and applied to the corresponding aqueous electrolyte containing aniline and MOF particles. The employment of MOFs with their large and small cages and 3-D structures in synthesizing a nanocomposite was assumed to be efficient constitutes to induce more non-smooth and porous structures, approved by scanning electron microscopy (SEM) images. Three different MOFs were incorporated to synthesize the desired nanocomposites and the preliminary experiments showed that all of them, particularly the one containing MOF2, have higher extraction performances in compared with PANI. The applicability of the new fiber coating was examined by headspace-solid phase microextraction (HS-SPME) of some chlorobenzenes (CBs) from aqueous samples. Influencing parameters on the synthesize and extraction processes including the electrodeposition voltage and its duration time, the weight ratio of PANI and MOF, the ionic strength, desorption temperature and time, and extraction time and temperature were optimized. The developed method was validated by analyzing the spiked distilled water and gas chromatography-mass spectrometry (GC-MS). Under optimum condition, the relative standard deviation (RSD%) values for a double distilled water spiked with the selected CBs at 20ngL(-1) were 5-8% (n=3) and the detection limits were below 0.2ngL(-1). The linear dynamic range (LDR) of the method was in the concentration range of 0.5-1000ngL(-1) (R(2)>0.9994). The fiber-to-fiber reproducibility was found to be in the range of 4-7%. Eventually, various real-water samples were analyzed by the MOF/PANI-based HS-SPME and GC-MS and the relative recovery values were found to be in the range of 92-98%. PMID:26792446

  17. Characterization and semiquantitative analysis of volatiles in seedless watermelon varieties using solid-phase microextraction.

    Science.gov (United States)

    Beaulieu, John C; Lea, Jeanne M

    2006-10-01

    Seedless triploid watermelons have increased in popularity since the early 1990s, and the demand for seedless fruit is on the rise. Sweetness and sugars are crucial breeding focuses for fruit quality. Volatiles also play an important role; yet, we found no literature for seedless varieties and no reports using solid-phase microextraction (SPME) in watermelon. The objective of this experiment was to identify volatile and semivolatile compounds in five seedless watermelon varieties using carboxen divinylbenzene polydimethylsiloxane solid-phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS). Fully ripe watermelon was squeezed through miracloth to produce rapid juice extracts for immediate headspace SPME GC-MS. Aldehydes, alcohols, ketones, and one furan (2-pentyl furan, a lipid oxidation product) were recovered. On the basis of total ion count peak area, the most abundant compounds in five varieties were 3-nonen-1-ol/(E,Z)-2,6-nonadienal (16.5-28.2%), (E)-2-nonenal (10.6-22.5%), and (Z)-6-nonenal (2.0-11.3%). Hexanal was most abundant (37.7%) in one variety (Petite Perfection) [corrected] The most abundant ketone was 6-methyl-5-hepten-2-one (2.7-7.7%). Some sensory attributes reported for these compounds are melon, citrus, cucumber, orange, rose, floral, guava, violet, vegetable, green, grassy, herbaceous, pungent, fatty, sweet, and waxy. Identifying and relating these compounds to sensory attributes will allow for future monitoring of the critical flavor compounds in seedless watermelon after processing and throughout fresh-cut storage. PMID:17002453

  18. Development of simple immunoradiometric assays using avidin coupled to polystyrene beads as a common solid phase

    International Nuclear Information System (INIS)

    In this paper, we describe the preparation and application of avidin coupled polystyrene beads as a common solid phase for use in immunoradiometric assays (IRMAs). The assay system is based on two matched commercial monoclonal antibodies, of which, the capture antibody is biotinylated using biotinamidocaproate N-hydroxysuccinimide ester and the detection antibody is radiolabeled with 125I by conventional Chloramine-T method. Avidin was immobilized on the polystyrene beads through a primary coat of bovine serum albumin using glutaraldhyde activation method. Various factors, such as concentration of reagents, incubation time, etc. were optimised to obtain a simple assay protocol consisting of only two pipetting steps, namely, that of a mixture of the two labelled antibodies (radiolabelled and biotinylated) and of the standard or sample. The advantage of the Avidin-Biotin system is the improved sensitivity, economy of antibody and the possibility to use a common solid phase in assays for different analytes. Using the polystyrene beads along with the novel decanting device, it has been possible to achieve the convenience of the 'coated-tube' technology without the expensive automation necessary for large scale preparation of antibody coated tubes. This protocol has been successfully applied to Prolactin, LH and FSH assays. The sensitivity of the Prolactin assay is 8μIU/mL (0.3 ng/mL), that of the FSH assay is 1mIU/mL and that of the LH assay is 0.9 mIU/mL. The intra-assay and inter-assay variations were <10%. Shelf life of the avidin coupled beads was found to be about 8 months and that of the biotin labelled antibodies up to 18 months. (author)

  19. Combined liquid and solid-phase extraction improves quantification of brain estrogen content

    Directory of Open Access Journals (Sweden)

    Andrew eChao

    2011-09-01

    Full Text Available Accuracy in quantifying brain-derived steroid hormones (‘neurosteroids’ has become increasingly important for understanding the modulation of neuronal activity, development, and physiology. Relative to other neuroactive compounds and classical neurotransmitters, steroids pose particular challenges with regard to isolation and analysis, owing to their lipid solubility. Consequently, anatomical studies of the distribution of neurosteroids have relied primarily on the expression of neurosteroid synthesis enzymes. To evaluate the distribution of synthesis enzymes vis-à-vis the actual steroids themselves, traditional steroid quantification assays, including radioimmunoassays (RIA, have successfully employed liquid extraction methods (e.g., ether, dichloromethane or methanol to isolate steroids from microdissected brain tissue. Due to their sensitivity, safety and reliability, the use of commercial enzyme immunoassays (EIA for laboratory quantification of steroids in plasma and brain has become increasingly widespread. However, EIAs rely on enzymatic reactions in vitro, making them sensitive to interfering substances in brain tissue and thus producing unreliable results. Here, we evaluate the effectiveness of a protocol for combined, two-stage liquid/solid phase extraction as compared to conventional liquid extraction alone for the isolation of estradiol (E2 from brain tissue. We employ the songbird model system, in which brain steroid production is pronounced and linked to neural mechanisms of learning and plasticity. This study outlines a combined liquid-solid phase extraction protocol that improves the performance of a commercial EIA for the quantification of brain E2 content. We demonstrate the effectiveness of our optimized method for evaluating the region specificity of brain E2 content, compare these results to established anatomy of the estrogen synthesis enzyme and estrogen receptor, and discuss the nature of potential EIA interfering

  20. Magnetic solid-phase extraction using carbon nanotubes as sorbents: a review.

    Science.gov (United States)

    Herrero-Latorre, C; Barciela-García, J; García-Martín, S; Peña-Crecente, R M; Otárola-Jiménez, J

    2015-09-10

    Magnetic solid-phase extraction (M-SPE) is a procedure based on the use of magnetic sorbents for the separation and preconcentration of different organic and inorganic analytes from large sample volumes. The magnetic sorbent is added to the sample solution and the target analyte is adsorbed onto the surface of the magnetic sorbent particles (M-SPs). Analyte-M-SPs are separated from the sample solution by applying an external magnetic field and, after elution with the appropriate solvent, the recovered analyte is analyzed. This approach has several advantages over traditional solid phase extraction as it avoids time-consuming and tedious on-column SPE procedures and it provides a rapid and simple analyte separation that avoids the need for centrifugation or filtration steps. As a consequence, in the past few years a great deal of research has been focused on M-SPE, including the development of new sorbents and novel automation strategies. In recent years, the use of magnetic carbon nanotubes (M-CNTs) as a sorption substrate in M-SPE has become an active area of research. These materials have exceptional mechanical, electrical, optical and magnetic properties and they also have an extremely large surface area and varied possibilities for functionalization. This review covers the synthesis of M-CNTs and the different approaches for the use of these compounds in M-SPE. The performance, general characteristics and applications of M-SPE based on magnetic carbon nanotubes for organic and inorganic analysis have been evaluated on the basis of more than 110 references. Finally, some important challenges with respect the use of magnetic carbon nanotubes in M-SPE are discussed. PMID:26388472

  1. Environmentally Friendly Method: Development and Application to Carbon Aerogel as Sorbent for Solid-Phase Extraction.

    Science.gov (United States)

    Dong, Sheying; Huang, Guiqi; Su, Meiling; Huang, Tinglin

    2015-10-14

    We developed two simple, fast, and environmentally friendly methods using carbon aerogel (CA) and magnetic CA (mCA) materials as sorbents for micro-solid-phase extraction (μ-SPE) and magnetic solid-phase extraction (MSPE) techniques. The material performances such as adsorption isotherm, adsorption kinetics, and specific surface area were discussed by N2 adsorption-desorption isotherm measurements, ultraviolet and visible (UV-vis) spectrophotometry, scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HR-TEM). The experimental results proved that the heterogeneities of CA and mCA were well modeled with the Freundlich isotherm model, and the sorption process well followed the pseudo-second-order rate equation. Moreover, plant growth regulators (PGRs) such as kinetin (6-KT), 6-benzylaminopurine (6-BA), 2,4-dichlorophenoxyacetic acid (2,4-D), and uniconazole (UN) in a reservoir raw water sample were selected as the evaluation of applicability for the proposed μ-SPE and MSPE techniques using high performance liquid chromatography (HPLC). The experimental conditions of two methods such as the amount of sorbent, extraction time, pH, salt concentration, and desorption conditions were studied. Under the optimized conditions, two extraction methods provided high recoveries (89-103%), low the limits of detection (LODs) (0.01-0.2 μg L(-1)), and satisfactory analytical features in terms of precision (relative standard deviation, RSD, 1.7-5.1%, n=3). This work demonstrates the feasibility and the potential of CA and mCA materials as sorbents for μ-SPE and MSPE techniques. Besides, it also could serve as a basis for future development of other functional CAs in pretreatment technology and make them valuable for analysis of pollutants in environmental applications. PMID:26389684

  2. PZT-like structural phase transitions in the BiFeO3-KNbO3 solid solution.

    Science.gov (United States)

    Lennox, Robert C; Taylor, Daniel D; Vera Stimpson, Laura J; Stenning, Gavin B G; Jura, Marek; Price, Mark C; Rodriguez, Efrain E; Arnold, Donna C

    2015-06-21

    Despite the high prominence of the perovskites BiFeO(3) and KNbO(3) the solid solution between the two has received little attention. We report a detailed neutron and synchrotron X-ray powder diffraction, and Raman spectroscopy study which demonstrates an R3c→P4mm→Amm2 series of structural phase transitions similar to that exhibited by the PbZrO(3)-PbTiO(3) solid solution. PMID:25859922

  3. Second Order Kinetic Modeling of Headspace Solid Phase Microextraction of Flavors Released from Selected Food Model Systems

    OpenAIRE

    Jiyuan Zhang; Mun-Wai Cheong; Bin Yu; Philip Curran; Weibiao Zhou

    2014-01-01

    The application of headspace-solid phase microextraction (HS-SPME) has been widely used in various fields as a simple and versatile method, yet challenging in quantification. In order to improve the reproducibility in quantification, a mathematical model with its root in psychological modeling and chemical reactor modeling was developed, describing the kinetic behavior of aroma active compounds extracted by SPME from two different food model systems, i.e., a semi-solid food and a liquid food....

  4. A parametric analysis of waves propagating in a porous solid saturated by a three-phase fluid.

    Science.gov (United States)

    Santos, Juan E; Savioli, Gabriela B

    2015-11-01

    This paper presents an analysis of a model for the propagation of waves in a poroelastic solid saturated by a three-phase viscous, compressible fluid. The constitutive relations and the equations of motion are stated first. Then a plane wave analysis determines the phase velocities and attenuation coefficients of the four compressional waves and one shear wave that propagate in this type of medium. A procedure to compute the elastic constants in the constitutive relations is defined next. Assuming the knowledge of the shear modulus of the dry matrix, the other elastic constants in the stress-strain relations are determined by employing ideal gedanken experiments generalizing those of Biot's theory for single-phase fluids. These experiments yield expressions for the elastic constants in terms of the properties of the individual solid and fluids phases. Finally the phase velocities and attenuation coefficients of all waves are computed for a sample of Berea sandstone saturated by oil, gas, and water. PMID:26627777

  5. Numerical simulation and analysis of solid-liquid two-phase three-dimensional unsteady flow in centrifugal slurry pump

    Institute of Scientific and Technical Information of China (English)

    吴波; 汪西力; 徐海良

    2015-01-01

    Based on RNGk-ε turbulence model and sliding grid technique, solid−liquid two-phase three-dimensional (3-D) unsteady turbulence of full passage in slurry pump was simulated by means of Fluent software. The effects of unsteady flow characteristics on solid−liquid two-phase flow and pump performance were researched under design condition. The results show that clocking effect has a significant influence on the flow in pump, and the fluctuation of flow velocity and pressure is obvious, particularly near the volute tongue, at the position of small sections of volute and within diffuser. Clocking effect has a more influence on liquid-phase than on solid-phase, and the wake-jet structure of relative velocity of solid-phase is less obvious than liquid-phase near the volute tongue and the impeller passage outlet. The fluctuation of relative velocity of solid-phase flow is 7.6% smaller than liquid-phase flow at the impeller outlet on circular path. Head and radial forces of the impeller are 8.1% and 85.7% of fluctuation, respectively. The results provide a theoretical basis for further research for turbulence, improving efficient, reducing the hydraulic losses and wear. Finally, field tests were carried out to verify the operation and wear of slurry pump.

  6. On the formation of molecules and solid-state compounds from the AGB to the PN phases

    CERN Document Server

    Garcia-Hernandez, D A

    2016-01-01

    During the asymptoyic giant branch (AGB) phase, different elements are dredge-up to the stellar surface depending on progenitor mass and metallicity. When the mass loss increases at the end of the AGB, a circumstellar dust shell is formed, where different (C-rich or O-rich) molecules and solid-state compounds are formed. These are further processed in the transition phase between AGB stars and planetary nebulae (PNe) to create more complex organic molecules and inorganic solid-state compounds (e.g., polycyclic aromatic hydrocarbons, fullerenes, and graphene precursors in C-rich environments and oxides and crystalline silicates in O-rich ones). We present an observational review of the different molecules and solid-state materials that are formed from the AGB to the PN phases. We focus on the formation routes of complex fullerene (and fullerene-based) molecules as well as on the level of dust processing depending on metallicity.

  7. Cheese is a reliable alternative meal for solid-phase gastric emptying study.

    Science.gov (United States)

    Drubach, Laura A; Kourmouzi, Vasiliki; Fahey, Frederic H

    2010-05-01

    We evaluated the labeling stability of several alternative meals that could be used to perform solid-phase gastric emptying study. Cooked egg whites labeled with technetium-99m sulfur colloid served as a control. Packaged instant oatmeal and instant mashed potatoes were prepared by adding hot water. Cheddar cheese was melted. Peanut butter was added to bread. The different meals were mixed with technetium-99m sulfur colloid (2.2-3.7 MBq), chopped into small pieces and placed in a glass tube containing gastric juice. Four samples of each meal were analyzed after 1 and 4 h of agitation with a 3-D rotator (two samples per time point). The meal samples were washed with 2 ml of saline and filtered using a blood transfusion filter. The activity in each sample before and after filtering was assayed in a dose calibrator. The percentage of initial radioactivity remaining with the meal of admixture with gastric juice was measured and the average of the two samples was taken. The percentage of activity bound to the solid phase was 98.2+/-1.9, 95.6+/-1.1, 62.1+/-1.7, 41.8+/-0.6, and 74.5+/-3.8% at 1 h and 98.5+/-1.0, 95.8+/-2.6, 77.2+/-6.8, 55.5+/-3.4 and 40.2+/-22.1 at 4 h for egg whites, cheese, oatmeal, mashed potatoes and peanut butter respectively. For egg whites and cheese, there was no significant difference between the values at 1 and 4 h (P>0.8). Cheddar cheese provides an alternative meal for assessing solid gastric emptying in children comparable to egg whites. Oatmeal and mashed potatoes had low and variable labeling stability and are not recommended. In view of the significant proportion of pediatric patients who refuse to eat scrambled eggs or have allergy to eggs, the availability of other meal choices is essential. The versatility of cheddar cheese, which can be added to macaroni or as a topping on pizza, makes it a useful alternative to labeled eggs. PMID:20145582

  8. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    International Nuclear Information System (INIS)

    Highlights: ► The use of CNTs as sorbent for metal species in solid phase extraction has been described. ► Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. ► Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes – due to their high adsorption and desorption capacities – have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  9. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    Energy Technology Data Exchange (ETDEWEB)

    Herrero Latorre, C., E-mail: carlos.herrero@usc.es [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain); Alvarez Mendez, J.; Barciela Garcia, J.; Garcia Martin, S.; Pena Crecente, R.M. [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain)

    2012-10-24

    Highlights: Black-Right-Pointing-Pointer The use of CNTs as sorbent for metal species in solid phase extraction has been described. Black-Right-Pointing-Pointer Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. Black-Right-Pointing-Pointer Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes - due to their high adsorption and desorption capacities - have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  10. SOLID-LIQUID PHASE TRANSFER CATALYZED SYNTHESIS OF CINNAMYL ACETATE-KINETICS AND ANALYSIS OF FACTORS AFFECTING THE REACTION IN A BATCH REACTOR

    Science.gov (United States)

    The use of solid-liquid phase transfer catalysis has an advantage of carrying out reaction between two immiscible substrates, one in solid phase and the other in liquid phase, with high selectivity and at relatively low temperatures. In this study we investigated the synthesis ci...

  11. Application of solid-phase extraction for determination of phenolic compounds in barrique wines.

    Science.gov (United States)

    Matejícek, D; Klejdus, B; Mikes, O; Sterbová, D; Kubán, V

    2003-09-01

    A fast, selective and sensitive chromatographic method has been developed for determination of gallic, protocatechuic, p-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, benzoic, ferulic, sinapic, cinnamic, and ellagic acids and p-hydroxybenzaldehyde, vanillin, syringaldehyde, 2-furfural, 5-methylfurfural, and 5-methoxyfurfural. The compounds from untreated wine samples were pre-concentrated and cleaned using solid-phase extraction on RP-105 polymeric sorbent. The cartridge was conditioned with methanol and water. Co-extracted ballast substances were rinsed from the sorbent with 0.1 mol L(-1) hydrochloric acid-methanol, 1:4 (v/ v). Retained phenolic compounds were selectively eluted with diethyl ether. A linear mobile phase gradient containing 0.3% acetic acid and methanol was used for final baseline chromatographic separation on a Hypersil BDS C18 column. Limits of detection (LOD=3 s(bl)) in the range 5.2 to 181.2 microg L(-1), resolution (R) better than 1.7, and repeatability of 2.7-5.1% (RSD for real samples) were achieved. The method was applied for quantification of individual phenolic compounds in barrique wines. PMID:12923605

  12. Bioactive phenols in algae: the application of pressurized-liquid and solid-phase extraction techniques.

    Science.gov (United States)

    Onofrejová, L; Vasícková, J; Klejdus, B; Stratil, P; Misurcová, L; Krácmar, S; Kopecký, J; Vacek, J

    2010-01-20

    A new extraction technique based on the off-line combination of pressurized-liquid with solid-phase extraction (PLE-SPE) is described. The method was used for the extraction of bioactive phenolic acids (protocatechuic, p-hydroxybenzoic, 2,3-dihydroxybenzoic, chlorogenic, vanillic, caffeic, p-coumaric, salicylic acid), cinnamic acid and hydroxybenzaldehydes (p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, vanillin) from in vitro culture of two freshwater algae (Anabaena doliolum and Spongiochloris spongiosa) and from food products of marine macroalgae Porphyra tenera (nori) and Undaria pinnatifida (wakame). For the identification and quantification of the compounds the molecular ions [M-H](-) and specific fragments were analyzed by quadrupole mass spectrometry analyzer connected on-line with a reversed-phase HPLC system. Our analysis showed that the freshwater algae and marine algal products contained submicrogram or microgram level of above-mentioned phenols per gram of lyophilized sample. In addition, the total phenol content (Folin-Ciocalteu assay) and antioxidant activity (TEAC assay, Trolox equivalent antioxidant capacity assay) of the PLE-SPE extracts were determined and discussed. PMID:19410410

  13. Molecularly imprinted polymers-curcuminoids and its application for solid phase extraction

    Science.gov (United States)

    Wulandari, Meyliana; Amran, M. B.; Lopez, A. B. Descalzo; Urraca, J. L.; Moreno-Bondi, M. C.

    2014-03-01

    Molecularly Imprinted Polymers (MIPs) for the selective recognition properties of curcumin (CUR), a cancer chemopreventive agent were obtained by a non-covalent imprinting approach with bisdemetoxycurcumin (BDMC) as the template molecule. The double bond of BDMC has been reduced in order not to be involved in polymerization and make the template molecules easy to be eluted. Several functional monomers have been evaluated to maximize the interactions with the template molecule during polymerization. MIPs prepared by bulk of N-(2-aminoethyl) metacrylamid hydrochlorideas functional monomer, ethylene glycol dimethacrylate as crosslinker, 2,2'-azobis (2'4-dimethyl valeronitril) as initiator and acetonitrile as porogen. Non-imprinted polymer (NIP) have been also synthesized for reference purposes. UV-vis spectroscopy has been used to predict the template to functional monomer ratio which indicates the formation of 2:1 complexes between monomer and curcumin and the association constants (K11 = 2529 μM and K12 = 1960.75 μM in acetonitrile). The capacity and imprinting factor have been evaluated as stationary phases in high-pressure liquid chromatography to CUR and BDMC. The binding properties and the homogeneity of the binding sites of the different polymers have been studied by Freundlich isotherm modeling and weight average affinity and number of binding sites. One of the foremost applications of molecular imprinting has been in molecularly imprinted solid phase extraction and it has the ability to separate and preconcentrate between closely related compounds in curcuminoids.

  14. Electromembrane surrounded solid phase microextraction using electrochemically synthesized nanostructured polypyrrole fiber.

    Science.gov (United States)

    Mohammadkhani, Elham; Yamini, Yadollah; Rezazadeh, Maryam; Seidi, Shahram

    2016-04-22

    Electromembrane surrounded solid phase microextraction using conductive polymers as the sorbent is carried out for the first time for extraction of two antidepressants including amitriptyline (AMI) and doxepin (DOX), as model analytes. The polypyrrole coating was prepared and utilized as both cathode and SPME sorbent. Different variables such as the conditions for preparation of polypyrrole fiber, pH of the donor and the acceptor phases, applied voltage, and extraction time were optimized. Under the optimized conditions, figures of merit of the proposed method were investigated in human whole blood and urine samples. Intra- and inter-assay precisions ranged between 3.1-7.5% and 7.6-12.3%, respectively were obtained in different extraction media. Detection limits of 0.15 and 0.05 for AMI and 0.3 and 0.1ngmL(-1) for DOX were achieved in the urine and blood samples, respectively. Linearity of the method was studied up to 50.0ngmL(-1) for both analytes and coefficients of determination better than 0.9966 were achieved. Regardless of the high sample cleanup, which makes the proposed method suitable for analysis of drugs from complicated matrices, clean chromatograms were obtained. Finally, the proposed method was applied for analysis of AMI and DOX in different real samples and reasonable data were obtained. PMID:27033980

  15. Volatile profile of yellow passion fruit juice by static headspace and solid phase microextraction techniques

    Directory of Open Access Journals (Sweden)

    Gilberto Costa Braga

    2015-02-01

    Full Text Available The profile of volatile compounds of yellow passion fruit juice was analyzed by solid phase microextraction headspace (HS-SPME and optimized static headspace (S-HS extraction techniques. Time, temperature, NaCl concentration and sample volume headspace equilibrium parameters was adjusted to the S-HS technique. The gaseous phase in the headspace of samples was collected and injected into a gas chromatograph coupled to a mass spectrometer. In the HS-SPME technique was identified 44 volatile compounds from the yellow passion fruit juice, but with S-HS only 30 compounds were identified. Volatile esters were majority in both techniques, being identified ethyl butanoate, ethyl hexanoate, (3z-3-hexenyl acetate, hexyl acetate, hexyl butanoate and hexyl hexanoate. Aldehydes and ketones were not identified in S-HS, but were in HS-SPME. β-Pinene, p-cymene, limonene, (Z-β-ocimene, (E-β-ocimene, γ-terpinene, α-terpinolene and (E -4,8-dimethyl-1, 3,7 - nonatriene terpenes were identified in both techniques. This study showed that the S-HS optimized extraction technique was effective to recovery high concentrations of the major volatile characteristics compounds in the passion fruit, such as ethyl butanoate and ethyl hexanoate, which can be advantageous due to the simplicity of the method.

  16. Structural Analysis of Perfluoropropanoyl Fluoride in the Gas, Liquid, and Solid Phases.

    Science.gov (United States)

    Berrueta Martínez, Yanina; Reuter, Christian G; Vishnevskiy, Yury V; Bava, Yanina B; Picone, A Lorena; Romano, Rosana M; Stammler, Hans-Georg; Neumann, Beate; Mitzel, Norbert W; Della Védova, Carlos O

    2016-04-21

    The coexistence of two conformers in perfluoropropanoyl fluoride, CF3CF2C(O)F, differing in the CC-CF dihedral angle (gauche 85(10)% and anti 15(10)%), has been determined by means of gas-phase electron diffraction (GED). Quantum-chemical calculations performed at the MP2 and B3LYP approximations and cc-pVTZ basis sets reproduce the experimental values with confidence. By contrast, FTIR spectra give no clear evidence for the anti-conformer in the gas phase. Information on this less abundant but stable rotamer is obtained from matrix-isolation/FTIR spectroscopy and liquid Raman spectroscopy. In situ crystallization and single-crystal X-ray diffraction (XRD) data reveal the presence of solely the gauche-conformation in the solid state. A set of intermolecular interactions including C═O···C═O, C-F···F-C, and F···C═O is detected. The nature of bonding and the relative stabilities of gauche- and anti-conformers are explored using natural bond orbitals. PMID:27023801

  17. Catalytically solid-phase self-organization of nanoporous SnS with optical depolarizability.

    Science.gov (United States)

    Cheng, Chih-Hsien; Chi, Yu-Chieh; Wu, Chung-Lun; Lin, Chun-Jung; Tsai, Ling-Hsuan; Chang, Jung-Hung; Chen, Mu Ku; Shih, Min-Hsiung; Lee, Chao-Kuei; Wu, Chih-I; Tsai, Din Ping; Lin, Gong-Ru

    2016-02-28

    The catalytic solid-phase synthesis of self-organized nanoporous tin sulfide (SnS) with enhanced absorption, manipulative transmittance and depolarization features is demonstrated. Using an ultralow radio-frequency (RF) sputtering power, the variation of the orientation angle between the anodized aluminum oxide (AAO) membrane and the axis of the sputtered ion beam detunes the catalytically synthesized SnS from nanorod to nanoporous morphology, along the sidewall of the AAO membrane. The ultraslow catalytic sputtering synthesis on the AAO at the RF plasma power of 20 W and the orientation angle of 0° regulates the porosity and integrality of nanoporous SnS, with average pore diameter of 80-150 nm. When transferring from planar to nanoporous structure, the phase composition changes from SnS to SnS2-Sn2S3, and the optical bandgap shrinks from 1.43 to 1.16 eV, due to the preferred crystalline orientation, which also contributes to an ultralow reflectance of minimum of >5 × 10(4) cm(-1) at the wavelength between 200 and 700 nm, due to the red-shifting of the absorption spectrum to at least 100 nm. The catalytically self-organized nanoporous SnS causes strong haze and beam divergence of 20°-30° by depolarized nonlinear scattering at the surface, which favors the solar energy conversion with reduced surface reflection and enhanced photon scattering under preserved transmittance. PMID:26842460

  18. Supported liquid membrane-protected molecularly imprinted fibre for solid-phase microextraction of thiabendazole.

    Science.gov (United States)

    Barahona, Francisco; Turiel, Esther; Martín-Esteban, Antonio

    2011-05-23

    In this work, molecularly imprinted polymer fibres (MIP-fibre) have been prepared and evaluated for solid-phase microextraction (SPME), using thiabendazole (TBZ) as template. Inherent limitations of molecular imprinted polymers, such as target recognition in aqueous media, have been solved with the use of organic supported liquid membrane (SLM) protecting the MI-SPME process. MIP-fibres were located inside a polypropylene hollow capillary and protected by an organic solvent immobilized as a thin SLM in the pores of the capillary wall. The extraction procedure involved two simultaneous processes: liquid phase microextraction using polypropylene hollow fibres (HF-LPME) of the analytes from the sample to an organic acceptor solution through a SLM; and SPME of the analytes from the organic acceptor solution to a MIP-fibre inside the polypropylene capillary. The developed methodology was optimized and applied to the extraction of TBZ form spiked orange juices. Calibration curves showed good linearity in the concentration range under study (0.01-5.00 mg L(-1)) and a regression coefficient better than 0.995 was obtained. The detection limit was 4 μg L(-1), low enough to permit the satisfactory analysis of TBZ in real samples, according to European regulation. Relative standard deviations ranged below 10%, indicating good repeatability. By this manner, the advantages of inherent selectivity of MIP SPME fibres and the enrichment and sample cleanup capability of the HF-LPME have been successfully combined into a single device. PMID:21565306

  19. Studies on acidification in two-phase biomethanation process of municipal solid waste.

    Science.gov (United States)

    Bhattacharyya, J K; Kumar, Sunil; Devotta, Sukumar

    2008-01-01

    Biomethanation of municipal solid waste (MSW) is a slow process and the yield of biogas is usually low. Enhancement of acidification is necessary to increase the biogas yield in biomethanation of MSW. MSW contains a significant fraction of ligno-cellulosic material. The acidification of these materials influences the biogas yield. In the present study, hydrolysis and acidification have been considered as a combined phase. Experiments have been conducted to study the effect of recirculation of leachate on the acidification stage of the two-phase biomethanation process. Chemical oxygen demand (COD) and volatile fatty acid (VFA) were considered as indicator parameters. The study was also conducted to investigate the effect of using acid and alkali solution of 0.1% concentration in the acidification study. It was observed that daily recirculation of leachate does not have any major impact on the acidification process. It was also observed that treatment of MSW with sodium hydroxide yields leachate of significantly higher COD and VFA values compared to others. PMID:17276666

  20. Liquid carry-over in an injection moulded all-polymer chip system for immiscible phase magnetic bead-based solid-phase extraction

    DEFF Research Database (Denmark)

    Kistrup, Kasper; Sørensen, Karen Skotte; Wolff, Anders;

    2014-01-01

    We present an all-polymer, single-use microfluidic chip system produced by injection moulding and bonded by ultrasonic welding. Both techniques are compatible with low-cost industrial mass-production. The chip is produced for magnetic bead-based solid-phase extraction facilitated by immiscible...