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Sample records for high purity cw

  1. High purity products by crystallisation

    NARCIS (Netherlands)

    Verdoes, D.; Bassett, J.M.

    2009-01-01

    Crystallisation from a melt or solution has the potential to yield a product with a very high purity in a single equilibrium step. Pure crystals have to be separated from the impure mother liquor, which is usually done by standard solid-liquid separation techniques like filtration or centrifugation.

  2. High-Purity Germanium Characterization

    Science.gov (United States)

    Weinandt, Nick; Sun, Yongchen; Mei, Dongming

    2010-11-01

    Underground germanium crystal growth is a main focus of the CUBED 2010 research in the state of South Dakota where the DUSEL will be hosted. High-purity germanium is essential to the construction of germanium detectors for neutrioless double-beta decay and dark matter experiments planned for DUSEL. The characterization of germanium ingots and crystals is an important part of the high-purity germanium crystal growth process. Through the characterization process, we can learn important information such as net impurity concentration and crystal structure. The information can be fed back to the zone refining and crystal growth processes. Resistivity measurements and Hall Effect experiments were used to understand the impurity concentration of the germanium bars. Both experiments were run at 77K to avoid thermal conductivity. When resistivity and Hall Effect experiments are coupled with future research into and Spectroscopies, we can begin to understand exactly what impurities are present in the sample. With resistivity, the Hall Effect, Photo-Thermal Ionization Spectroscopy, and Deep-Level Transit Spectroscopy, we can gain a more complete understanding of the characterization techniques and the growing of the crystal. At the conference I would be able to show the results obtained from our experiments

  3. High-purity limestone in the UAE

    OpenAIRE

    Mitchell, Clive

    2014-01-01

    High-purity limestone in the UAE Clive Mitchell, Industrial Minerals Specialist, British Geological Survey, Nottingham, UK Email: High-purity limestone can be defined as carbonate rock that contains greater than 97% calcium carbonate (CaCO3). Limestone is thought to have the largest number of commercial uses of all industrial minerals; including as construction material, mineral fillers (paper, paint, plastic, rubber and pharmaceuticals), adhesives, abrasives, fertilis...

  4. Purification of Ultra-High Purity Aluminum

    OpenAIRE

    Hashimoto, E; Ueda, Y; Kino, T.

    1995-01-01

    Zone refining was applied experimentally to high-purity aluminium produced by a combination of the three-layer electrolytic refining process and the segregation process. The cropping procedure was effective in increasing the efficiency of zone refining. The highest residual resistance ratio R(300K)/R(4.2K) obtained was more than 150 000 in the bulk value, corresponding to a refined purity better than 99.99999 %.

  5. Production of dry, high purity nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Haas, O.W.; Prasad, R.; Smolarek, J.

    1991-04-02

    This patent describes an improved process for the production of dry, high purity nitrogen from air. It comprises passing a wet, high purity nitrogen from a pressure swing adsorption system or wet feed air stream to a dryer membrane system capable of selectively permeating water from the wet stream; passing relatively dry purge gas to the low pressure permeate side of the dryer membrane system to facilitate the carrying away of water vapor from the surface of the membrane and maintaining the driving force for removal of water vapor through the membrane from the high purity nitrogen or feed air stream for enhanced moisture removal therefrom. The relatively dry purge gas comprising waste gas from the pressure swing adsorption system or nitrogen product gas, whereby the provision of the purge gas on the permeate side of the dryer membrane system facilitates the desired moisture removal with minimum loss of product gas.

  6. Splitting of high power, cw proton beams

    CERN Document Server

    Facco, Alberto; Berkovits, Dan; Yamane, Isao; 10.1103/PhysRevSTAB.10.091001

    2007-01-01

    A simple method for splitting a high power, continuous wave (cw) proton beam in two or more branches with low losses has been developed in the framework of the EURISOL (European Isotope Separation On-Line adioactive Ion Beam Facility) design study. The aim of the system is to deliver up to 4 MW of H beam to the main radioactive ion beam production target, and up to 100 kWof proton beams to three more targets, simultaneously. A three-step method is used, which includes magnetic neutralization of a fractionof the main H- beam, magnetic splitting of H- and H0, and stripping of H0 to H+. The method allowsslow raising and individual fine adjustment of the beam intensity in each branch.

  7. Nonlinear control of high purity distillation columns

    OpenAIRE

    Groebel, Markus; Allgöwer, Frank; Storz, Markus; Gilles, Ernst Dieter

    1994-01-01

    Two simple models of distillation columns are studied to investigate their suitability for the practical use with exact I/O-linearization. An extension of exact I/O-linearization, the asymptotically exact I/O-linearization is applied to the control of a high purity distillation column, using one of these models to derive the static state feedback law. Simulation studies demonstrate the advantage of asymptotically exact I/O-linearization versus classical exact I/O-linearization techniques. Exp...

  8. New high power CW klystrons at TED

    CERN Document Server

    Beunas, A; Marchesin, R

    2003-01-01

    Thales Electron Devices (TED) has been awarded a contract by CERN to develop and produce 20 units of the klystrons needed to feed the Large Hadrons Collider (LHC). Each of these delivers 300 kW of CW RF power at 400 MHz. Three klystrons have been delivered to CERN up to now.

  9. Multielement trace determination in high purity advanced ceramics ...

    Indian Academy of Sciences (India)

    The crucial point of this project is the certification of the total purity of high purity materials, each representing one element of the periodic table. A variety of different analytical methods was necessary to determine the trace contents of metallic and non-metallic impurities from almost the whole periodic table in the high purity ...

  10. Highly Accurate Sensor for High-Purity Oxygen Determination Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this STTR effort, Los Gatos Research (LGR) and the University of Wisconsin (UW) propose to develop a highly-accurate sensor for high-purity oxygen determination....

  11. Production of high purity granular metals: cadmium, zinc, lead

    Directory of Open Access Journals (Sweden)

    Shcherban A. P.

    2017-04-01

    Full Text Available Cadmium, zinc and lead are constituent components of many semiconductor compounds. The obtained high purity distillates and ingots are large-size elements, which is not always convenient to use, and thus require additional grinding, which does not always allow maintaining the purity of the original materials. For the growth of semiconductor and scintillation single crystals it is advisable to use "friable" granular high-purity distillates, which can be processed without the risk of contamination. For example, the European low-background experiment LUCIFER required more than 20 kg of high-purity granulated zinc, which was agreed to be supplied by NSC KIPT. This task was then extended to cadmium and lead. Motivated by these tasks, the authors of this paper propose complex processes of deep refining of cadmium, zinc and lead by vacuum distillation. A device producing granules has been developed. The process of granulation of high-purity metals is explored. The purity of produced granules for cadmium and zinc is >99,9999, and >99,9995% for lead granules. To prevent oxidation of metal granules during exposition to air, chemical methods of surface passivation were used. Organic solvent based on dimethylformamide used as a coolant improves the resistance of granules to atmospheric corrosion during the granulation of high purity Cd, Zn and Pb.

  12. PROSPECTS FOR A VERY HIGH POWER CW SRF LINAC

    Energy Technology Data Exchange (ETDEWEB)

    Robert Rimmer

    2010-06-01

    Steady development in SRF accelerator technology combined with the success of large scale installations such as CEBAF at Jefferson Laboratory and the SNS Linac at ORNL gives credibility to the concept of very high average power CW machines for light sources or Proton drivers. Such machines would be powerful tools for discovery science in themselves but could also pave the way to reliable cost effective drivers for such applications as neutrino factories, an energy-frontier muon collider, nuclear waste transmutation or accelerator driven subcritical reactors for energy production. In contrast to machines such as ILC that need maximum accelerating gradient, the challenges in these machines are mainly in efficiency, reliability, beam stability, beam loss and of course cost. In this paper the present state of the art is briefly reviewed and options for a multi-GeV, multi-MW CW linac are discussed.

  13. Performance Analysis of a High Resolution Airborne FM-CW Synthetic Aperture Radar

    NARCIS (Netherlands)

    Wit, J.J.M. de; Hoogeboom, P.

    2003-01-01

    Compact FM-CW technology combined with high resolution SAR techniques should pave the way for a small and cost effective imaging radar. A research project has been inìtiated to investigate the feasibility of FM-CW SAR. Within the framework of the project an operational airborne FM-CW SAR

  14. High purity materials as targets for radioisotope production: Needs ...

    Indian Academy of Sciences (India)

    Artificial transmutation of an element employing thermal neutrons in a reactor or high energy particle accelerators (cyclotrons) are the routes of radioisotope production world over. Availability of high purity target materials, natural or enriched, are crucial for any successful radioisotope programme. Selection of stable ...

  15. Thermocurrent dosimetry with high purity aluminum oxide

    Energy Technology Data Exchange (ETDEWEB)

    Fullerton, G.D.; Cameron, J.R.; Moran, P.R.

    1976-01-01

    The application of thermocurrent (TC) to ionizing radiation dosimetry was studied. It was shown that TC in alumina (Al/sub 2/O/sub 3/) has properties that are suited to personnel dosimetry and environmental monitoring. TC dosimeters were made from thin disks of alumina. Aluminum electrodes were evaporated on each side: on one face a high voltage electrode and on the opposite face a measuring electrode encircled by a guard ring. Exposure to ionizing radiation resulted in stored electrons and holes in metastable trapping sites. The signal was read-out by heating the dosimeter with a voltage source and picnometer connected in series between the opposite electrodes. The thermally remobilized charge caused a transient TC. The thermogram, TC versus time or temperature, is similar to a TL glow curve. Either the peak current or the integrated current is a measure of absorbed dose. Six grades of alumina were studied from a total of four commercial suppliers. All six materials displayed radiation induced TC signals. Sapphire of uv-grade quality from the Adolf Meller Co. (AM) had the best dosimetry properties of those investigated. Sources of interference were studied. Thermal fading, residual signal and radiation damage do not limit TC dosimetry. Ultraviolet light can induce a TC response but it is readily excluded with uv-opaque cladding. Improper surface preparation prior to electrode evaporation was shown to cause interference. A spurious TC signal resulted from polarization of surface contaminants. Spurious TC was reduced by improved cleaning prior to electrode application. Polished surfaces resulted in blocking electrodes and caused a sensitivity shift due to radiation induced thermally activated polarization. This was not observed with rough cut surfaces.

  16. Electrochemical study of aluminum corrosion in boiling high purity water

    Science.gov (United States)

    Draley, J. E.; Legault, R. A.

    1969-01-01

    Electrochemical study of aluminum corrosion in boiling high-purity water includes an equation relating current and electrochemical potential derived on the basis of a physical model of the corrosion process. The work involved an examination of the cathodic polarization behavior of 1100 aluminum during aqueous oxidation.

  17. Preparation of high purity tellurium by zone refining

    Indian Academy of Sciences (India)

    This paper describes purification process of tellurium metal using zone refining technique under high purity hydrogen gas ambient in normal room environment. Process automation by newly designed stepper motor drive and allied process control instruments circumvent the complexity of electrical motors. It is observed that ...

  18. Analytical challenges in characterization of high purity materials

    Indian Academy of Sciences (India)

    Quite a good number of analytical challenges with specific reference to the characterization of high purity materials of relevance to nuclear technology were addressed and methodologies were developed for trace elemental analysis of both metallic and non-metallic constituents. A brief review of these analytical challenges ...

  19. Low cost routes to high purity silicon and derivatives thereof

    Science.gov (United States)

    Laine, Richard M; Krug, David James; Marchal, Julien Claudius; Mccolm, Andrew Stewart

    2013-07-02

    The present invention is directed to a method for providing an agricultural waste product having amorphous silica, carbon, and impurities; extracting from the agricultural waste product an amount of the impurities; changing the ratio of carbon to silica; and reducing the silica to a high purity silicon (e.g., to photovoltaic silicon).

  20. Surface passivation of high purity granular metals: zinc, cadmium, lead

    Directory of Open Access Journals (Sweden)

    Pirozhenko L. A.

    2017-10-01

    Full Text Available For the high purity metals (99.9999%, such as zinc, cadmium, and lead, which are widely used as initial components in growing semiconductor and scintillation crystals (CdTe, CdZnTe, ZnSe, (Cd, Zn, Pb WO4, (Cd, Zn, Pb MoO4 et al., it is very important to ensure reliable protection of the surface from oxidation and adsorption of impurities from the atmosphere. The specific features of surface passivation of high purity cadmium, lead and zinc are not sufficiently studied and require specific methodologies for further studies. The use of organic solutions in the schemes of chemical passivation of the investigated metals avoids hydrolysis of the obtained protective films. The use of organic solvents with pure cation and anion composition as the washing liquid prevents chemisorption of ions present in the conventionally used distilled water. This keeps the original purity of the granular metals. Novel compositions of etchants and etching scheme providing simultaneous polishing and passivation of high purity granular Zn, Cd and Pb are developed. Chemical passivation allows storing metals in the normal atmospheric conditions for more than half a year for Zn and Cd and up to 30 days for Pb without changing the state of the surface. The use of the glycerol-DMF solution in the processes for obtaining Pb granules provides self-passivation of metal surfaces and eliminates the additional chemical processing while maintaining the quality of corrosion protection.

  1. Operational experience with CW high gradient and high QL cryomodules

    Energy Technology Data Exchange (ETDEWEB)

    Hovater, J. Curt [JLAB; Allison, Trent L. [JLAB; Bachimanchi, Ramakrishna [JLAB; Daly, Edward F. [JLAB; Drury, Michael A. [JLAB; Lahti, George E. [JLAB; Mounts, Clyde I. [JLAB; Nelson, Richard M. [JLAB; Plawski, Tomasz E. [JLAB

    2014-12-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of ten new 100 MV cryomodules (80 cavities). The superconducting RF cavities are designed to operate CW at an accelerating gradient of 19.3 MV/m with a QL of 3×107. The RF system employs single cavity control using new digital LLRF controls and 13 kW klystrons. Recently, all of the new cryomodules and associated RF hardware and software have been commissioned and operated in the CEBAF accelerator. Electrons at linac currents up to 10 ?A have been successfully accelerated and used for nuclear physics experiments. This paper reports on the commissioning and operation of the cryomodules and RF system.

  2. Eighth CW and High Average Power RF Workshop

    CERN Document Server

    2014-01-01

    We are pleased to announce the next Continuous Wave and High Average RF Power Workshop, CWRF2014, to take place at Hotel NH Trieste, Trieste, Italy from 13 to 16 May, 2014. This is the eighth in the CWRF workshop series and will be hosted by Elettra - Sincrotrone Trieste S.C.p.A. (www.elettra.eu). CWRF2014 will provide an opportunity for designers and users of CW and high average power RF systems to meet and interact in a convivial environment to share experiences and ideas on applications which utilize high-power klystrons, gridded tubes, combined solid-state architectures, high-voltage power supplies, high-voltage modulators, high-power combiners, circulators, cavities, power couplers and tuners. New ideas for high-power RF system upgrades and novel ways of RF power generation and distribution will also be discussed. CWRF2014 sessions will start on Tuesday morning and will conclude on Friday lunchtime. A visit to Elettra and FERMI will be organized during the workshop. ORGANIZING COMMITTEE (OC): Al...

  3. High-purity limestone assessment : from mine to market

    OpenAIRE

    Mitchell, Clive

    2009-01-01

    High-purity limestone can be defined as carbonate rock that contains greater than 97% calcium carbonate (CaCO3, typically as calcite); it is often referred to as high-calcium or highly-calcitic limestone. Limestone has by far the largest number of commercial uses of all the industrial minerals; including construction (aggregate, cement and dimension stone), mineral fillers (for paper, paint, plastic, rubber and pharmaceuticals), adhesives, abrasives, fertilisers and soil conditioners, the pro...

  4. High purity biodegradable magnesium coating for implant application

    Energy Technology Data Exchange (ETDEWEB)

    Salunke, Pravahan [School of Energy, Environmental, Biological and Medical Engineering, University of Cincinnati, Cincinnati, OH 45221-0071 (United States); Shanov, Vesselin, E-mail: vesselin.shanov@uc.edu [School of Energy, Environmental, Biological and Medical Engineering, University of Cincinnati, Cincinnati, OH 45221-0071 (United States); Witte, Frank [Laboratory for Biomechanics and Biomaterials, Department of Orthopedic Surgery, Hannover Medical School, Anna-von-Borries-Str. 1-7, 30625 Hannover (Germany); Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Beer Sheva, 84105 Israel (Israel)

    2011-12-15

    This paper describes efforts to create high purity Mg coating by Physical Vapor Deposition (PVD) technique that is appropriate for implant applications and to improve the interaction between the implant and the biological environment. The in vitro and in vivo tests conducted with Mg coatings that consist of grains with controlled size demonstrated promising properties in terms of lower corrosion and acceptable foreign body reaction which makes them prospective as biodegradable metallic materials.

  5. Development of a High Resolution Airborne Millimeter Wave FM-CW SAR

    NARCIS (Netherlands)

    Meta, A.; Wit, J.J.M. de; Hoogeboom, P.

    2004-01-01

    The combination of compact FM-CW radar technology and high resolution SAR processing techniques should pave the way for the development of a small, lightweight and cost effective imaging radar. In the field of airborne earth observation, SAR is however a novel application for FM-CW radars. At IRCTR

  6. Detailed characterization of CW- and pulsed-pump four-wave mixing in highly nonlinear fibers

    DEFF Research Database (Denmark)

    Lillieholm, Mads; Galili, Michael; Grüner-Nielsen, L.

    2016-01-01

    We present a quantitative comparison of continuouswave- (CW) and pulsed-pump four-wave mixing (FWM) in commercially available highly nonlinear fibers (HNLFs), and suggest properties for which the CW and pulsed FWM bandwidths are limited in practice. The CWand pulsed-pump parametric gain is charac......We present a quantitative comparison of continuouswave- (CW) and pulsed-pump four-wave mixing (FWM) in commercially available highly nonlinear fibers (HNLFs), and suggest properties for which the CW and pulsed FWM bandwidths are limited in practice. The CWand pulsed-pump parametric gain...... bandwidth. However, an inverse scaling of the TOD with the dispersion fluctuations, leads to different CW-optimized fibers, which depend only on the even dispersion-orders....

  7. High purity neodymium acetate from mixed rare earth carbonates

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, Carlos A. da Silva; Rocha, Soraya M. Rizzo da; Vasconcellos, Mari E. de; Lobo, Raquel M.; Seneda, Jose A., E-mail: cqueiroz@ipen.b, E-mail: smrrocha@ipen.b, E-mail: mstela@ipen.b, E-mail: rmlobo@ipen.b, E-mail: jaseneda@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Pedreira, Walter dos R., E-mail: walter.pedreira@fundacentro.gov.b [Fundacao Jorge Duprat Figueiredo de Seguranca e Medicina do Trabalho (FUNDACENTRO), Sao Paulo, SP (Brazil)

    2011-07-01

    A simple and economical chemical process for obtaining high purity neodymium acetate is discussed. The raw material in the form rare earth carbonate is produced industrially from the chemical treatment of Brazilian monazite. Ion exchange chromatography technique with a strong cationic resin, proper to water treatment, and without the use of retention ions was used for the fractionating of the rare earth elements (REE). In this way, it was possible to obtain 99.9% pure Nd{sub 2}O{sub 3} in yields greater than or equal 80%, with the elution of the REE using ammonium salt of ethylenediaminetetraacetic acid (EDTA) solution in pH controlled. The complex of EDTA-neodymium was transformed into neodymium oxide, which was subsequently dissolved in acetic acid to obtain the neodymium acetates. Molecular absorption spectrophotometry was used to monitor the neodymium content during the process and sector field inductively coupled plasma mass spectrometry was used to certify the purity of the neodymium acetates. The typical neodymium acetates obtained contain the followings contaminants in {mu}g g{sup -1}: Sc(5.1); Y (0.9); La (1.0); Ce (6.1); Pr (34,4); Sm (12.8); Eu (1.1); Gd (15.4); Tb (29.3); Dy (5.2), Ho(7.4); Er (14.6); Tm (0.3); Yb (2.5); Lu (1.0). The high purity neodymium acetates obtained from this procedure have been applied, replacing the imported product, in research and development area on rare earth catalysts. (author)

  8. A study on the production of high purity gallium (IV)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Wung; Son, Yong Un; Park, Kyung Ho; Choi, Young Youn; Yoo, Yeon Tae; Nam, Chul Woo [Korea Institute of Geology Mining and Materials, Taejon (Korea, Republic of)

    1996-12-01

    Gallium from GaAs semiconductor scrap was recovered by thermal-decomposition with packing tower type vacuum furnace. And then refined by the electro deposition using fused slat (GaCl{sub 2}). The important result obtained from the study are follows; 1) In the thermal-decomposition process, the recovery of gallium decreased with increasing temperature of the melting point of gallium (1,237 deg. C). At the temperature higher than this, the rate of thermal-decomposition of GaAs became faster and recovery of gallium increased because of the destroy of GaAs structure. 2) The thermal-decomposition of packing tower furnace was carried out with 30 kg sample. The optimum conditions are pressure 5 x 10{sup -2} mmHg, temperature 1,250 deg. C, reaction time 4 hours. At this condition the yield and purity of gallium are higher then 98 % and 99.994 %. 3) The activation energy of fused salt electrorefining for gallium is 16.6 K joule/mole. in the temperature range between 164 deg. C and 197 deg. C. 4) High purity gallium (99.9999%) is obtained at cell voltage 100 mV{approx} 300 mV, current density 1.5 A/cm{sup 2} and the temperature of 473 deg. K with fused GaCl{sub 2}. 5) With purification of GaCl{sub 2} and electro-deposition using fused salt the continues refining process of gallium developed. 6) the flowchart of the high purity gallium recovery process was developed in the study. (author). 24 refs., tabs., figs.

  9. Recent developments in high purity niobium metal production at CBMM

    Energy Technology Data Exchange (ETDEWEB)

    Abdo, Gustavo Giovanni Ribeiro, E-mail: Gustavo.abdo@cbmm.com.br; Sousa, Clovis Antonio de Faria, E-mail: Clovis@cbmm.com.br; Guimarães, Rogério Contato, E-mail: Rogerio.guimaraes@cbmm.com.br; Ribas, Rogério Marques, E-mail: Rogerio.ribas@cbmm.com.br; Vieira, Alaércio Salvador Martins, E-mail: Alaercio.vieira@cbmm.com.b; Menezes, Andréia Duarte, E-mail: Amenezes@cbmm.com.br; Fridman, Daniel Pallos, E-mail: Daniel.fridman@cbmm.com.br; Cruz, Edmundo Burgos, E-mail: Edmundo@cbmm.com.br [CBMM – Companhia Brasileira de Metalurgia e Mineração Córrego da Mata, s/n Araxá, Minas Gerais 38183-903 Brazil (Brazil)

    2015-12-04

    CBMM is a global supplier of high quality niobium products including pure niobium, the focus of this paper. CBMM’s position has been consolidated over three decades of producing high purity niobium metal ingots. The company supplies, among other products, commercial and reactor grade niobium ingots. One of the main uses of CBMM’s ingots is for the manufacture of particle accelerators (superconducting radio frequency – SRF – cavities), where the purity and homogeneity of niobium metal is essentially important for good performance. CBMM constantly strives to improve process controls and product quality, and is currently implementing innovations in production, research and development to further improve ingot quality. The main aim is to reduce the content of interstitial elements, such as nitrogen (N), oxygen (O), carbon (C), and hydrogen (H), starting with the raw materials through the final step of ingot production. CBMM held the first trial to produce the world’s largest-diameter niobium ingot (as cast 535 mm). The results of this initial trial presented very low levels of interstitial impurities (N, O, C, H), allowing the achievement of residual resistivity ratio (RRR) values very close to 300 in a six-melt process in an electron beam furnace. These values were reached with 850 ppm of tantalum. SRF cavities will be produced with this material in order to study the effect of low impurities and high RRR on the Q factor and accelerating gradient.

  10. Space-Qualifiable High Reliability Frequency-Stabilized CW Laser Source Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the development and space qualification of a high reliability frequency-stabilized CW laser source at 1064 nm wavelength region to satisfy the...

  11. Space-Qualifiable High Reliability Frequency-Stabilized CW Laser Source Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose the SBIR Phase II effort to develop and space-qualify a 1.06 micron high reliability frequency-stabilized CW laser source that fully satisfies the...

  12. MACRIB High efficiency - high purity hadron identification for DELPHI

    CERN Document Server

    Albrecht, Z; Moch, M; Albrecht, Zoltan; Feindt, Michael; Moch, Markus

    2001-01-01

    Analysis of the data shows that hadron tags of the two standard DELPHI particle identification packages RIBMEAN and HADSIGN are weakly correlated. This led to the idea of constructing a neural network for both kaon and proton identification using as input the existing tags from RIBMEAN and HADSIGN, as well as preproccessed TPC and RICH detector measurements together with additional dE/dx information from the DELPHI vertex detector. It will be shown in this note that the net output is much more efficient at the same purity than the HADSIGN or RIBMEAN tags alone. We present an easy-to-use routine performing the necessary calculations.

  13. Evaluation of purity with its uncertainty value in high purity lead stick by conventional and electro-gravimetric methods.

    Science.gov (United States)

    Singh, Nahar; Singh, Niranjan; Tripathy, S Swarupa; Soni, Daya; Singh, Khem; Gupta, Prabhat K

    2013-06-26

    A conventional gravimetry and electro-gravimetry study has been carried out for the precise and accurate purity determination of lead (Pb) in high purity lead stick and for preparation of reference standard. Reference materials are standards containing a known amount of an analyte and provide a reference value to determine unknown concentrations or to calibrate analytical instruments. A stock solution of approximate 2 kg has been prepared after dissolving approximate 2 g of Pb stick in 5% ultra pure nitric acid. From the stock solution five replicates of approximate 50 g have been taken for determination of purity by each method. The Pb has been determined as PbSO4 by conventional gravimetry, as PbO2 by electro gravimetry. The percentage purity of the metallic Pb was calculated accordingly from PbSO4 and PbO2. On the basis of experimental observations it has been concluded that by conventional gravimetry and electro-gravimetry the purity of Pb was found to be 99.98 ± 0.24 and 99.97 ± 0.27 g/100 g and on the basis of Pb purity the concentration of reference standard solutions were found to be 1000.88 ± 2.44 and 1000.81 ± 2.68 mg kg-1 respectively with 95% confidence level (k = 2). The uncertainty evaluation has also been carried out in Pb determination following EURACHEM/GUM guidelines. The final analytical results quantifying uncertainty fulfills this requirement and gives a measure of the confidence level of the concerned laboratory. Gravimetry is the most reliable technique in comparison to titremetry and instrumental method and the results of gravimetry are directly traceable to SI unit. Gravimetric analysis, if methods are followed carefully, provides for exceedingly precise analysis. In classical gravimetry the major uncertainties are due to repeatability but in electro-gravimetry several other factors also affect the final results.

  14. Portable High Sensitivity and High Resolution Sensor to Determine Oxygen Purity Levels Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this Phase I STTR project is to develop a highly sensitive oxygen (O2) sensor, with high accuracy and precision, to determine purity levels of high...

  15. Purity analyses of high-purity organic compounds with nitroxyl radicals based on the Curie–Weiss law

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Nobuhiro, E-mail: nobu-matsumoto@aist.go.jp; Shimosaka, Takuya [National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), AIST Central-3, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8563 (Japan)

    2015-05-07

    This work reports an attempt to quantify the purities of powders of high-purity organic compounds with stable nitroxyl radicals (namely, 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO), 1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine (TEMPOL), and 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl benzoate (4-hydroxy-TEMPO benzoate)) in terms of mass fractions by using our “effective magnetic moment method,” which is based on both the Curie–Weiss law and a fundamental equation of electron paramagnetic resonance (ESR). The temperature dependence of the magnetic moment resulting from the radicals was measured with a superconducting quantum interference device magnetometer. The g value for each compound was measured with an X-band ESR spectrometer. The results of the purities were (0.998 ± 0.064) kg kg{sup −1} for TEMPO, (1.019 ± 0.040) kg kg{sup −1} for TEMPOL, and (1.001 ± 0.048) kg kg{sup −1} for 4-hydroxy-TEMPO benzoate. These results demonstrate that this analytical method as a future candidate of potential primary direct method can measure the purities with expanded uncertainties of approximately 5%.

  16. Precipitation of hydrides in high purity niobium after different treatments

    Energy Technology Data Exchange (ETDEWEB)

    Barkov, F.; Romanenko, A.; Trenikhina, Y.; Grassellino, A.

    2013-01-01

    Precipitation of lossy non-superconducting niobium hydrides represents a known problem for high purity niobium in superconducting applications. Using cryogenic optical and laser confocal scanning microscopy we have directly observed surface precipitation and evolution of niobium hydrides in samples after different treatments used for superconducting RF cavities for particle acceleration. Precipitation is shown to occur throughout the sample volume, and the growth of hydrides is well described by the fast diffusion-controlled process in which almost all hydrogen is precipitated at $T=140$~K within $\\sim30$~min. 120$^{\\circ}$C baking and mechanical deformation are found to affect hydride precipitation through their influence on the number of nucleation and trapping centers.

  17. A TNFR2-Agonist Facilitates High Purity Expansion of Human Low Purity Treg Cells.

    Directory of Open Access Journals (Sweden)

    Xuehui He

    Full Text Available Regulatory T cells (Treg are important for immune homeostasis and are considered of great interest for immunotherapy. The paucity of Treg numbers requires the need for ex vivo expansion. Although therapeutic Treg flow-sorting is feasible, most centers aiming at Treg-based therapy focus on magnetic bead isolation of CD4+CD25+ Treg using a good manufacturing practice compliant closed system that achieves lower levels of cell purity. Polyclonal Treg expansion protocols commonly use anti-CD3 plus anti-CD28 monoclonal antibody (mAb stimulation in the presence of rhIL-2, with or without rapamycin. However, the resultant Treg population is often heterogeneous and pro-inflammatory cytokines like IFNγ and IL-17A can be produced. Hence, it is crucial to search for expansion protocols that not only maximize ex vivo Treg proliferative rates, but also maintain Treg stability and preserve their suppressive function. Here, we show that ex vivo expansion of low purity magnetic bead isolated Treg in the presence of a TNFR2 agonist mAb (TNFR2-agonist together with rapamycin, results in a homogenous stable suppressive Treg population that expresses FOXP3 and Helios, shows low expression of CD127 and hypo-methylation of the FOXP3 gene. These cells reveal a low IL-17A and IFNγ producing potential and hardly express the chemokine receptors CCR6, CCR7 and CXCR3. Restimulation of cells in a pro-inflammatory environment did not break the stability of this Treg population. In a preclinical humanized mouse model, the TNFR2-agonist plus rapamycin expanded Treg suppressed inflammation in vivo. Importantly, this Treg expansion protocol enables the use of less pure, but more easily obtainable cell fractions, as similar outcomes were observed using either FACS-sorted or MACS-isolated Treg. Therefore, this protocol is of great interest for the ex vivo expansion of Treg for clinical immunotherapy.

  18. Differential Diode Laser Sensor for High-Purity Oxygen Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A compact portable sensor for determining the purity of oxygen concentrations near 100 percent is proposed based on differential absorption of two beams from a diode...

  19. High-power and highly reliable 638-nm band BA-LD for CW operation

    Science.gov (United States)

    Nishida, Takehiro; Kuramoto, Kyosuke; Abe, Shinji; Kusunoki, Masatsugu; Miyashita, Motoharu; Yagi, Tetsuya

    2017-10-01

    High-power laser diodes (LDs) are strongly demanded as light sources of display applications. In multiple spatial light modulator-type projectors or liquid crystal displays, the light source LDs are operated under CW condition. The high-power 638-nm band broad-area LD for CW operation was newly developed. The LD consisted of two stripes with each width of 75 μm to reduce both an optical power density at a front facet and a threshold current. The newly improved epitaxial technology was also applied to the LD to suppress an electron overflow from an active layer. The LD showed superior output characteristics, such as output of 1.77 W at case temperature of 55 °C with wall plug efficiency (WPE) of 23%, which was improved by 40% compared with the current product. The peak WPE at 25 °C reached 40.6% under the output power of 2.37 W, CW, world highest.

  20. Automation of the Characterization of High Purity Germanium Detectors

    Science.gov (United States)

    Dugger, Charles ``Chip''

    2014-09-01

    Neutrinoless double beta decay is a rare hypothesized process that may yield valuable insight into the fundamental properties of the neutrino. Currently there are several experiments trying to observe this process, including the Majorana DEMONSTRAOR experiment, which uses high purity germanium (HPGe) detectors to generate and search for these events. Because the event happens internally, it is essential to have the lowest background possible. This is done through passive detector shielding, as well as event discrimination techniques that distinguish between multi-site events characteristic of gamma-radiation, and single-site events characteristic of neutrinoless double beta decay. Before fielding such an experiment, the radiation response of the detectors must be characterized. A robotic arm is being tested for future calibration of HPGe detectors. The arm will hold a source at locations relative to the crystal while data is acquired. Several radioactive sources of varying energy levels will be used to determine the characteristics of the crystal. In this poster, I will present our work with the robot, as well as the characterization of data we took with an underground HPGe detector at the WIPP facility in Carlsbad, NM (2013). Neutrinoless double beta decay is a rare hypothesized process that may yield valuable insight into the fundamental properties of the neutrino. Currently there are several experiments trying to observe this process, including the Majorana DEMONSTRAOR experiment, which uses high purity germanium (HPGe) detectors to generate and search for these events. Because the event happens internally, it is essential to have the lowest background possible. This is done through passive detector shielding, as well as event discrimination techniques that distinguish between multi-site events characteristic of gamma-radiation, and single-site events characteristic of neutrinoless double beta decay. Before fielding such an experiment, the radiation response of

  1. Development of high purity vanadium alloys for fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Muroga, Takeo [National Inst. for Fusion Sience, Toki, Gifu (Japan)

    2002-07-01

    Vanadium alloys are most attractive candidate materials for liquid Li self-cooled blanket system of fusion reactors. This paper summarizes the program and its activities of the NIFS (National Institute for Fusion Science), Japan for developments of high purity V-4Cr-4Ti alloys. The results from NIFS-Heats show various benefits by reducing the level of oxygen. Significant improvement of the impact properties of the welded joint by reducing oxygen level is one of examples in recent studies. Collaboration is in progress, in which those heats are being characterized by a number of research groups including Japanese universities, and international collaboration partners in the US, Russia and China. The impact tests of irradiated speciments are in progress for further investigation. Significant progress has been made recently on the insulator ceramic coating in static conditions in the Japan-USA Cooperation Program. The understanding on the condition of in-situ CaO coating in liquid Li was enhanced. Based on these achievements, a flowing loop test is being planned to investigate the effects of temperature gradient and Li chemistry. (Y. Tanaka)

  2. Mesophase Formation Stabilizes High-purity Magic-sized Clusters

    KAUST Repository

    Nevers, Douglas R.

    2018-01-27

    Magic-sized clusters (MSCs) are renowned for their identical size and closed-shell stability that inhibit conventional nanoparticle (NP) growth processes. Though MSCs have been of increasing interest, understanding the reaction pathways toward their nucleation and stabilization is an outstanding issue. In this work, we demonstrate that high concentration synthesis (1000 mM) promotes a well-defined reaction pathway to form high-purity MSCs (>99.9%). The MSCs are resistant to typical growth and dissolution processes. Based on insights from in-situ X-ray scattering analysis, we attribute this stability to the accompanying production of a large, hexagonal organic-inorganic mesophase (>100 nm grain size) that arrests growth of the MSCs and prevents NP growth. At intermediate concentrations (500 mM), the MSC mesophase forms, but is unstable, resulting in NP growth at the expense of the assemblies. These results provide an alternate explanation for the high stability of MSCs. Whereas the conventional mantra has been that the stability of MSCs derives from the precise arrangement of the inorganic structures (i.e., closed-shell atomic packing), we demonstrate that anisotropic clusters can also be stabilized by self-forming fibrous mesophase assemblies. At lower concentration (<200 mM or >16 acid-to-metal), MSCs are further destabilized and NPs formation dominates that of MSCs. Overall, the high concentration approach intensifies and showcases inherent concentration-dependent surfactant phase behavior that is not accessible in conventional (i.e., dilute) conditions. This work provides not only a robust method to synthesize, stabilize, and study identical MSC products, but also uncovers an underappreciated stabilizing interaction between surfactants and clusters.

  3. State-of-the-art in analytical characterization of high purity solid ...

    Indian Academy of Sciences (India)

    Unknown

    State-of-the-art in analytical characterization of high purity solid samples by different spectroscopic methods. S S GRAZHULENE. Institute of Microelectronics Technology and High Purity Materials, RAS 142432, Chernogolovka, Russia. Abstract. Facilities and some results of several spectroscopic methods which have ...

  4. The Hydrometallurgical Extraction and Recovery of High-Purity Silver

    Science.gov (United States)

    Hoffmann, James E.

    2012-06-01

    -bearing inputs, will be described in detail to demonstrate how typical chemical engineering unit process and unit operations have supplanted classic smelting and fire refining techniques. The Kennecott Copper Company, which has operated a hydrometallurgical circuit successfully for the recovery of high-purity silver from the slimes wet chlorination residue, has permitted me to provide some operation information and results using the technology. Both Phelps Dodge and Kennecott should be recognized for their forward-looking attitude in undertaking the conversion of conceptual chemistry into successful, full-scale plants. The process as employed at Phelps Dodge is discussed at length in reference (J.E. Hoffmann and B. Wesstrom: Hydrometallurgy, 1994, vol. 94, pp. 69-105).

  5. High spectral purity Kerr frequency comb radio frequency photonic oscillator.

    Science.gov (United States)

    Liang, W; Eliyahu, D; Ilchenko, V S; Savchenkov, A A; Matsko, A B; Seidel, D; Maleki, L

    2015-08-11

    Femtosecond laser-based generation of radio frequency signals has produced astonishing improvements in achievable spectral purity, one of the basic features characterizing the performance of an radio frequency oscillator. Kerr frequency combs hold promise for transforming these lab-scale oscillators to chip-scale level. In this work we demonstrate a miniature 10 GHz radio frequency photonic oscillator characterized with phase noise better than -60 dBc Hz(-1) at 10 Hz, -90 dBc Hz(-1) at 100 Hz and -170 dBc Hz(-1) at 10 MHz. The frequency stability of this device, as represented by Allan deviation measurements, is at the level of 10(-10) at 1-100 s integration time-orders of magnitude better than existing radio frequency photonic devices of similar size, weight and power consumption.

  6. Radiochemical purity of Mo and Tc solution obtained after irradiation and dissolution of Mo-100-enriched and ultra-high-purity natural Mo disks

    Energy Technology Data Exchange (ETDEWEB)

    Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey D. [Argonne National Lab. (ANL), Argonne, IL (United States); Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-09-01

    Four irradiations of ultra-high-purity natural Mo targets and one irradiation using 97.4% Mo-100-enriched material were performed. The purpose of these irradiations was to determine whether the presence of Sn stabilizer in the H2O2 used for the dissolution of sintered Mo disks can affect the radiochemical purity of the final K2MoO4 in 5M KOH solution. Results from radiochemical purity tests performed using thin-layer paper chromatography show that even 2– 3× excess of Sn-stabilized H2O2 typically used for dissolution of sintered Mo disks did not affect the radiochemical purity of the final product.

  7. Motion Compensation for a High Resolution Ka-Band Airborne FM-CW SAR

    NARCIS (Netherlands)

    Meta, A; Lorga, J.F.M.; Wit, J.J.M. de; Hoogeboom, P.

    2005-01-01

    Airborne synthetic aperture radar is a promising new application for FM-CW radars. At the IRCTR, an operational demonstrator system has been developed in order to investigate the practicability of FM-CW SAR and to prove that an FM-CW SAR system can be operated in an efficient manner from a small

  8. High-precision efficiency calibration of a high-purity co-axial germanium detector

    Energy Technology Data Exchange (ETDEWEB)

    Blank, B., E-mail: blank@cenbg.in2p3.fr [Centre d' Etudes Nucléaires de Bordeaux Gradignan, UMR 5797, CNRS/IN2P3, Université de Bordeaux, Chemin du Solarium, BP 120, 33175 Gradignan Cedex (France); Souin, J.; Ascher, P.; Audirac, L.; Canchel, G.; Gerbaux, M.; Grévy, S.; Giovinazzo, J.; Guérin, H.; Nieto, T. Kurtukian; Matea, I. [Centre d' Etudes Nucléaires de Bordeaux Gradignan, UMR 5797, CNRS/IN2P3, Université de Bordeaux, Chemin du Solarium, BP 120, 33175 Gradignan Cedex (France); Bouzomita, H.; Delahaye, P.; Grinyer, G.F.; Thomas, J.C. [Grand Accélérateur National d' Ions Lourds, CEA/DSM, CNRS/IN2P3, Bvd Henri Becquerel, BP 55027, F-14076 CAEN Cedex 5 (France)

    2015-03-11

    A high-purity co-axial germanium detector has been calibrated in efficiency to a precision of about 0.15% over a wide energy range. High-precision scans of the detector crystal and γ-ray source measurements have been compared to Monte-Carlo simulations to adjust the dimensions of a detector model. For this purpose, standard calibration sources and short-lived online sources have been used. The resulting efficiency calibration reaches the precision needed e.g. for branching ratio measurements of super-allowed β decays for tests of the weak-interaction standard model.

  9. [Simultaneously preparation of grams of high purity tyrosol, crenulatin and salidroside from Rhodiola crenulata].

    Science.gov (United States)

    Luo, Xin; Wang, Xue-jing; Li, Shi-ping; Zhang, Qiao; Zhao, Yi-wu; Huang Wen-zhe; Wang, Zhen-zhong; Xiao, Wei

    2015-04-01

    Tyrosol, crenulatin and salidroside are the main active constituents of Rhodiola crenulata, with extensive pharmacological activities. In the study, grams of high purity tyrosol, crenulatin and salidroside were simultaneously separated from R. crenulata by the first time. Firstly, R. crenulata was extracted by 70% alcohol. Then, with the yields of three compounds as the index, the macroporous resin was optimized. At last, grams of high purity tyrosol, crenulatin and salidroside were isolated by D-101 macroporousresin, purified by column chromatography. Detected by HPLC, the purity of three compounds were higher than 98%. This method has the advantages of simple process and operation, less dosage of organic solvent, highly yield and reproducibility, suitable for the simultaneously preparation of tyrosol, crenulatin and salidroside.

  10. Scaled-Up Synthesis and Characterization of High-Purity Graphene

    Science.gov (United States)

    Johnson, Patricia; Griep, Mark; Behler, Kristopher; Pesce-Rodrequez, Rose; Karna, Shashi; Sarney, Wendy; Duncan, Kate

    2011-03-01

    Graphene, a two-dimensional, single-atom sheet of carbon atoms, discovered in 2004, has emerged as a new class of novel nano-scale material due to its unique chemical and physical properties, and potential applications in a wide range of civilian and military technologies. However, a major challenge in its technological application is a lack of chemical/physical method(s) to produce/synthesize high-purity graphene in viable quantity. Another challenge in the technological application of graphene is a lack of detailed understanding of its structure-property relationship. In order to address these issues, we have developed a chemical exfoliation method that yields high-purity graphene in bulk quantity. The method is scalable to produce large quantities of high purity graphene. In this paper, we present the results of our synthetic approach and structure-property characterization of graphene.

  11. High purity, low dislocation GaAs single crystals

    Science.gov (United States)

    Chen, R. T.; Holmes, D. E.; Kirkpatrick, C. G.

    1983-01-01

    Liquid encapsulated Czochralski crystal growth techniques for producing undoped, high resistivity, low dislocation material suitable for device applications is described. Technique development resulted in reduction of dislocation densities in 3 inch GaAs crystals. Control over the melt stoichiometry was determined to be of critical importance for the reduction of twinning and polycrystallinity during growth.

  12. High-Purity Fe3S4 Greigite Microcrystals for Magnetic and Electrochemical Performance

    NARCIS (Netherlands)

    Li, Guowei; Zhang, Baomin; Yu, Feng; Novakova, Alla A.; Krivenkov, Maxim S.; Kiseleva, Tatiana Y.; Chang, Liao; Rao, Jiancun; Polyakov, Alexey O.; Blake, Graeme R.; de Groot, Robert A.; Palstra, Thomas T. M.

    2014-01-01

    High-purity Fe3S4 (greigite) microcrystals with octahedral shape were synthesized via a simple hydrothermal method using a surfactant. The as-prepared samples have the inverse spinel structure with high crystallinity. The saturation magnetization (M-s) reaches 3.74 mu(B) at 5 K and 3.51 mu(B) at

  13. Characterization of segmented large volume, high purity germanium detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bruyneel, B. [Koeln Univ. (Germany). Inst. fuer Kernphysik

    2006-07-01

    {gamma}-ray tracking in future HPGe arrays like AGATA will rely on pulse shape analysis (PSA) of multiple {gamma}-interactions. For this purpose, a simple and fast procedure was developed which enabled the first full characterization of a segmented large volume HPGe detector. An analytical model for the hole mobility in a Ge crystal lattice was developed to describe the hole drift anisotropy with experimental velocity values along the crystal axis as parameters. The new model is based on the drifted Maxwellian hole distribution in Ge. It is verified by reproducing successfully experimental longitudinal hole anisotropy data. A comparison between electron and hole mobility shows large differences for the longitudinal and tangential velocity anisotropy as a function of the electrical field orientation. Measurements on a 12 fold segmented, n-type, large volume, irregular shaped HPGe detector were performed in order to determine the parameters of anisotropic mobility for electrons and holes as charge carriers created by {gamma}-ray interactions. To characterize the electron mobility the complete outer detector surface was scanned in small steps employing photopeak interactions at 60 keV. A precise measurement of the hole drift anisotropy was performed with 356 keV rays. The drift velocity anisotropy and crystal geometry cause considerable rise time differences in pulse shapes depending on the position of the spatial charge carrier creation. Pulse shapes of direct and transient signals are reproduced by weighting potential calculations with high precision. The measured angular dependence of rise times is caused by the anisotropic mobility, crystal geometry, changing field strength and space charge effects. Preamplified signals were processed employing digital spectroscopy electronics. Response functions, crosstalk contributions and averaging procedures were taken into account implying novel methods due to the segmentation of the Ge-crystal and the digital electronics

  14. State-of-the-art in analytical characterization of high purity solid ...

    Indian Academy of Sciences (India)

    Facilities and some results of several spectroscopic methods which have potential applications in the field of analysis of solid high purity substances and which have been elaborated in Russia, will be discussed in this paper. Laser nondispersive atomic fluorescence method with glow discharge cathode sputtering atomiser, ...

  15. Variation of low temperature internal friction of microplastic deformation of high purity molybdenum single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Pal-Val, P.P. (AN Ukrainskoj SSR, Kharkov. Fiziko-Tekhnicheskij Inst. Nizkikh Temperatur); Kaufmann, H.J. (Akademie der Wissenschaften der DDR, Berlin)

    1984-08-01

    Amplitude and temperature spectra of ultrasound absorption in weakly deformed high purity molybdenum single crystals of different orientations were measured. The results were discussed in terms of parameter changes related to quasiparticle or dislocation oscillations, respectively, dislocation point defect interactions as well as defect generation at microplastic deformation.

  16. The use of molecular beam epitaxy for the synthesis of high purity III-V nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Spirkoska, D; Colombo, C; Heiss, M; Abstreiter, G; Fontcuberta i Morral, A [Walter Schottky Institut, Technische Universitaet Muenchen, D-85748 Garching (Germany)

    2008-11-12

    The synthesis methods and properties of catalyst-free III-V nanowires with molecular beam epitaxy (MBE) are reviewed. The two main techniques are selective-area epitaxy (SAE) and gallium-assisted synthesis. The excellent structure and ultra-high purity characteristics of the grown nanowires are presented by Raman and photoluminescence spectroscopy.

  17. Crystallographic Analysis of Nucleation at Hardness Indentations in High-Purity Aluminum

    DEFF Research Database (Denmark)

    Xu, Chaoling; Zhang, Yubin; Lin, Fengxiang

    2016-01-01

    Nucleation at Vickers hardness indentations has been studied in high-purity aluminum cold-rolled 12 pct. Electron channeling contrast was used to measure the size of the indentations and to detect nuclei, while electron backscattering diffraction was used to determine crystallographic orientation...

  18. 28-Day oral toxicity study in rats with high purity barley beta-glucan (Glucagel™)

    NARCIS (Netherlands)

    Jonker, D.; Hasselwander, O.; Tervilä-Wilo, A.; Tenning, P.P.

    2010-01-01

    Beta-glucans are glucose polymers present in cereal grains, particularly barley and oat. Consumption of these grains or concentrated beta-glucan preparations has been shown to lower blood cholesterol. The present study was conducted to assess the safety of a high purity (>75%) barley beta-glucan

  19. Effect of high-temperature heat treatment duration on the purity and ...

    Indian Academy of Sciences (India)

    The effect of high-temperature heat treatment on purity and structural changes of multiwalled carbon nanotubes (MWCNTs) were studied by subjecting the raw MWCNTs (pristine MWCNTs) to 2600°C for 60 and 120 min. Thermogravimetric analysis (TGA), X-ray diffraction, Raman spectroscopy, transmission electron ...

  20. High-power pulsed and CW diode-pumped mode-locked Nd:YAG lasers

    Science.gov (United States)

    Marshall, Larry R.; Hays, A. D.; Kaz, Alex; Kasinski, Jeff; Burnham, R. L.

    1991-01-01

    The operation of both pulsed and CW diode-pumped mode-locked Nd:YAG lasers are presented. The pulsed laser produced 1.0 mJ with pulsewidths of 90 psec at 20 Hz. The CW pumped laser produced 6 W output at 1.064 microns and 3 W output at 532 nm.

  1. Low-temperature fracture of high purity iron and its relationship to the grain boundary character

    Energy Technology Data Exchange (ETDEWEB)

    Ofuji, T. (Tohoku Univ., Sendai (Japan). Graduate School of Engineering Daido Special Steel Co. Ltd., Nagoya (Japan)); Suzuki, S. (Tohoku Univ., Sendai (Japan). Inst. of Materials Research Nippon Steel Corp., Tokyo (Japan)); Takai, S. (Tohoku Univ., Sendai (Japan). Inst. of Materials Research); Kimura, H. (Tohoku Univ., Sendai (Japan). Inst. of Materials Research)

    1992-02-01

    Mode of fracture and ductile-brittle transition temperature (DBTT) of high purity iron( 99.999% or higher ) was investigated by using two sets of specimens of different grain boundary character. The specimens having bamboo-type grain structure with high angle boundaries have fractured in the intergranular mode and their DBTT is between 110 and 125 K. Specimens with coarse grain structure have shown fractures in transgranular mode at and below 50 K. DBTT for intergranular fracture(IGF), if any, has been below 4.2 K and this has been in contrast with the the occurance of IGF even at 77K for less pure iron specimens(99.99 % or below). It has been concluded that DBTT for IGF, which has been the common fracture mode in pure iron depends strongly on the purity and grain boundary character of iron spocimens. DBTT has ranged from 125 to 4.2 K or below. Also, specimens of 99.99 % purity have been more susceptible to IGF than the specimens with 99.999 % purity. 8 refs., 6 figs.

  2. A Study of the Surface Quality of High Purity Copper after Heat Treatment

    CERN Document Server

    Aicheler, M; Atieh, S; Calatroni, S; Riddone, G; Lebet, S; Samoshkin, A

    2011-01-01

    Themanufacturing flow of accelerating structures for the compact linear collider, based on diamond-machined high purity copper components, include several thermal cycles (diffusion bonding, brazing of cooling circuits, baking in vacuum, etc.). The high temperature cycles may be carried out following different schedules and environments (vacuum, reducing hydrogen atmosphere, argon, etc.) and develop peculiar surface topographies which have been the object of extended observations. This study presents and discusses the results of scanning electron microscopy (SEM) and optical microscopy investigations.

  3. Charge collection performance of a segmented planar high-purity germanium detector

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, R.J. [Department of Physics, The University of Liverpool, Oliver Lodge Laboratory, Liverpool Merseyside L69 7ZE (United Kingdom)], E-mail: R.Cooper@liverpool.ac.uk; Boston, A.J.; Boston, H.C.; Cresswell, J.R.; Grint, A.N.; Harkness, L.J.; Nolan, P.J.; Oxley, D.C.; Scraggs, D.P. [Department of Physics, The University of Liverpool, Oliver Lodge Laboratory, Liverpool Merseyside L69 7ZE (United Kingdom); Lazarus, I.; Simpson, J. [STFC Daresbury Laboratory, Warrington, Cheshire WA4 4AD (United Kingdom); Dobson, J. [Rosemere Cancer Centre, Royal Preston Hospital, Preston PR2 9HT (United Kingdom)

    2008-10-01

    High-precision scans of a segmented planar high-purity germanium (HPGe) detector have been performed with a range of finely collimated gamma ray beams allowing the response as a function of gamma ray interaction position to be quantified. This has allowed the development of parametric pulse shape analysis (PSA) techniques and algorithms for the correction of imperfections in performance. In this paper we report on the performance of this detector, designed for use in a positron emission tomography (PET) development system.

  4. Focused electron beam induced deposition of copper with high resolution and purity from aqueous solutions

    Science.gov (United States)

    Esfandiarpour, Samaneh; Boehme, Lindsay; Hastings, J. Todd

    2017-03-01

    Electron-beam induced deposition of high-purity copper nanostructures is desirable for nanoscale rapid prototyping, interconnection of chemically synthesized structures, and integrated circuit editing. However, metalorganic, gas-phase precursors for copper introduce high levels of carbon contamination. Here we demonstrate electron beam induced deposition of high-purity copper nanostructures from aqueous solutions of copper sulfate. The addition of sulfuric acid eliminates oxygen contamination from the deposit and produces a deposit with ˜95 at% copper. The addition of sodium dodecyl sulfate (SDS), Triton X-100, or polyethylene glycole (PEG) improves pattern resolution and controls deposit morphology but leads to slightly reduced purity. High resolution nested lines with a 100 nm pitch are obtained from CuSO4-H2SO4-SDS-H2O. Higher aspect ratios (˜1:1) with reduced line edge roughness and unintended deposition are obtained from CuSO4-H2SO4-PEG-H2O. Evidence for radiation-chemical deposition mechanisms was observed, including deposition efficiency as high as 1.4 primary electrons/Cu atom.

  5. Focused electron beam induced deposition of copper with high resolution and purity from aqueous solutions.

    Science.gov (United States)

    Esfandiarpour, Samaneh; Boehme, Lindsay; Hastings, J Todd

    2017-03-24

    Electron-beam induced deposition of high-purity copper nanostructures is desirable for nanoscale rapid prototyping, interconnection of chemically synthesized structures, and integrated circuit editing. However, metalorganic, gas-phase precursors for copper introduce high levels of carbon contamination. Here we demonstrate electron beam induced deposition of high-purity copper nanostructures from aqueous solutions of copper sulfate. The addition of sulfuric acid eliminates oxygen contamination from the deposit and produces a deposit with ∼95 at% copper. The addition of sodium dodecyl sulfate (SDS), Triton X-100, or polyethylene glycole (PEG) improves pattern resolution and controls deposit morphology but leads to slightly reduced purity. High resolution nested lines with a 100 nm pitch are obtained from CuSO4-H2SO4-SDS-H2O. Higher aspect ratios (∼1:1) with reduced line edge roughness and unintended deposition are obtained from CuSO4-H2SO4-PEG-H2O. Evidence for radiation-chemical deposition mechanisms was observed, including deposition efficiency as high as 1.4 primary electrons/Cu atom.

  6. High-speed high-efficiency 500-W cw CO2 laser hermetization of metal frames of microelectronics devices

    Science.gov (United States)

    Levin, Andrey V.

    1996-04-01

    High-speed, efficient method of laser surface treatment has been developed using (500 W) cw CO2 laser. The principal advantages of CO2 laser surface treatment in comparison with solid state lasers are the basis of the method. It has been affirmed that high efficiency of welding was a consequence of the fundamental properties of metal-IR-radiation (10,6 mkm) interaction. CO2 laser hermetization of metal frames of microelectronic devices is described as an example of the proposed method application.

  7. The European Expression Of Interest For High Purity U-233 Materials

    Energy Technology Data Exchange (ETDEWEB)

    Giaquinto, Joseph M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Younkin, James R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-04-01

    The purpose of this letter report is to document the response for an Expression of Interest (EOI) sent to the European Safeguards and research and development (R&D) scientific communities for the distribution of small amounts of high purity 233U materials for use in safeguards, nonproliferation, and basic R&D in the nuclear disciplines. The intent for the EOI was to gauge the level of international interest for these materials from government and research institutions with programmatic missions in the nuclear security or nuclear R&D arena. The information contained herein is intended to provide information to assist key decision makers in DOE as to the ultimate disposition path for the high purity materials currently being recovered at Oak Ridge National Laboratory (ORNL) and only those items for which there is no United States (U.S.) sponsor identified.

  8. Comparison of Deformation in High-Purity Single/Large Grain and Polycrystalline Niobium Superconducting Cavities

    Energy Technology Data Exchange (ETDEWEB)

    Ganapati Rao Myneni; Peter Kneisel

    2005-07-10

    The current approach for the fabrication of superconducting radio frequency (SRF) cavities is to roll and deep draw sheets of polycrystalline high-purity niobium. Recently, a new technique was developed at Jefferson Laboratory that enables the fabrication of single-crystal high-purity Nb SRF cavities. To better understand the differences between SRF cavities fabricated out of fine-grained polycrystalline sheet in the standard manner and single crystal cavities fabricated by the new technique, two half-cells were produced according to the two different procedures and compared using a variety of analytical techniques including optical microscopy, scanning laser confocal microscopy, profilometry, and X-ray diffraction. Crystallographic orientations, texture, and residual stresses were determined in the samples before and after forming and this poster presents the results of this ongoing study.

  9. A computer control system for the PNC high power cw electron linac. Concept and hardware

    Energy Technology Data Exchange (ETDEWEB)

    Emoto, T.; Hirano, K.; Takei, Hayanori; Nomura, Masahiro; Tani, S. [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center; Kato, Y.; Ishikawa, Y.

    1998-06-01

    Design and construction of a high power cw (Continuous Wave) electron linac for studying feasibility of nuclear waste transmutation was started in 1989 at PNC. The PNC accelerator (10 MeV, 20 mA average current, 4 ms pulse width, 50 Hz repetition) is dedicated machine for development of the high current acceleration technology in future need. The computer control system is responsible for accelerator control and supporting the experiment for high power operation. The feature of the system is the measurements of accelerator status simultaneously and modularity of software and hardware for easily implemented for modification or expansion. The high speed network (SCRAM Net {approx} 15 MB/s), Ethernet, and front end processors (Digital Signal Processor) were employed for the high speed data taking and control. The system was designed to be standard modules and software implemented man machine interface. Due to graphical-user-interface and object-oriented-programming, the software development environment is effortless programming and maintenance. (author)

  10. Production of High Intracavity UV Power From a CW Laser Source

    Science.gov (United States)

    David, R. T.; Chyba, T. H.; Keppel, C. E.; Gaskell, D.; Ent, R.

    1998-01-01

    The goal of this research project is to create a prototype high power CW source of ultraviolet (UV) photons for photon-electron scattering at the Thomas Jefferson National Accelerator Facility (TJNAF), Hall B. The facility will use optical resonant cavities to produce a high photon flux. The technical approach will be to frequency-double the 514.5 mn light from an Argon-Ion Laser to create 0.1 to 1.0 watt in the UV. The produced UV power will be stored in a resonant cavity to generate an high intracavity UV power of 102 to 103 watts. The specific aim of this project is to first design and construct the low-Q doubling cavity and lock it to the Argon-Ion wavelength. Secondly, the existing 514.5 nm high-Q build-up cavity and its locking electronics will be modified to create high intracavity UV power. The entire system will then be characterized and evaluated for possible beam line use.

  11. Aluminium. II - A review of deformation properties of high purity aluminium and dilute aluminium alloys.

    Science.gov (United States)

    Reed, R. P.

    1972-01-01

    The elastic and plastic deformation behavior of high-purity aluminum and of dilute aluminum alloys is reviewed. Reliable property data, including elastic moduli, elastic coefficients, tensile, creep, fatigue, hardness, and impact are presented. Single crystal tensile results are discussed. Rather comprehensive reference lists, containing publications of the past 20 years, are included for each of the above categories. Defect structures and mechanisms responsible for mechanical behavior are presented. Strengthening techniques (alloys, cold work, irradiation, quenching, composites) and recovery are briefly reviewed.

  12. Operation of a high-purity silicon diode alpha particle detector at 1. 4 K

    Energy Technology Data Exchange (ETDEWEB)

    Martoff, C.J.; Kaczanowicz, E. (Temple Univ., Philadelphia, PA (USA)); Neuhauser, B.J.; Lopez, E.; Zhang, Y. (San Francisco State Univ., CA (USA)); Ziemba, F.P. (Quantrad Corp. (USA))

    1991-03-01

    Detection of alpha particles at temperatures as low as 1.4 K was demonstrated using a specially fabricated Si diode. The diode was 475 mm{sup 2} by 0.280 mm thick, fabricated from high-purity silicon with degenerately doped contacts. This is an important step toward development of dual-mode (ionization plus phonon) silicon detectors for low energy radiation. (orig.).

  13. High Purity Americium-241 for Fuel Cycle R&D Program

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Paul A. Lessing

    2011-07-01

    Previously the U.S. Department of Energy released Am-241 for various applications such as smoke detectors and Am-Be neutron sources for oil wells. At this date there is a shortage of usable, higher purity Am-241 in metal and oxide form available in the United States. Recently, the limited source of Am-241 has been from Russia with production being contracted to existing customers. The shortage has resulted in the price per gram rising dramatically over the last few years. DOE-NE currently has need for high purity Am-241 metal and oxide to fabricate fuel pellets for reactor testing in the Fuel Cycle R&D program. All the available high purity americium has been gathered from within the DOE system of laboratories. However, this is only a fraction of the projected needs of FCRD over the next 10 years. Therefore, FCR&D has proposed extraction and purification concepts to extract Am-241 from a mixed AmO2-PuO2 feedstock stored at the Savannah River Site. The most simple extraction system is based upon high temperature reduction using lanthanum metal with concurrent evaporation and condensation to produce high purity Am metal. Metallic americium has over a four order of magnitude higher vapor pressure than plutonium. Results from small-scale reduction experiments are presented. These results confirm thermodynamic predictions that at 1000 deg C metallic lanthanum reduces both PuO2 and AmO2. Faster kinetics are expected for temperatures up to about 1500 deg C.

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

    Directory of Open Access Journals (Sweden)

    Nicolae Chirilă

    2011-12-01

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

  15. CW operation of high-power blue laser diodes with polished facets on semi-polar ( 20 2 ¯ 1 ¯ ) GaN substrates

    KAUST Repository

    Pourhashemi, A.

    2016-10-11

    Continuous wave (CW) operation of high-power blue laser diodes (LDs) with polished facets on semi-polar (202̅1̅) gallium nitride (GaN) substrates is demonstrated. Ridge waveguide LDs were fabricated using indium GaN waveguiding layers and GaN cladding layers. At a lasing wavelength of 452 nm, the peak two-facet CW output power from an LD with uncoated facets was 1.71 W at a current of 3 A, corresponding to an optical power density of 32.04 MW/cm2 on each facet. The dependence of output power on current did not change with repeated CW measurements, indicating that the polished facets did not degrade under high-power CW operation. These results show that polished facets are a viable alternative to cleaved or etched facets for high-power CW semi-polar LDs.

  16. A prototype High Purity Germanium detector for high resolution gamma-ray spectroscopy at high count rates

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, R.J., E-mail: rjcooper@lbl.gov [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Amman, M.; Luke, P.N. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Vetter, K. [Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States); Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States)

    2015-09-21

    Where energy resolution is paramount, High Purity Germanium (HPGe) detectors continue to provide the optimum solution for gamma-ray detection and spectroscopy. Conventional large-volume HPGe detectors are typically limited to count rates on the order of ten thousand counts per second, however, limiting their effectiveness for high count rate applications. To address this limitation, we have developed a novel prototype HPGe detector designed to be capable of achieving fine energy resolution and high event throughput at count rates in excess of one million counts per second. We report here on the concept, design, and initial performance of the first prototype device.

  17. 100 kW CW highly-efficient multi-beam klystron for a future electron-ion collider

    Science.gov (United States)

    Teryaev, Vladimir E.; Shchelkunov, Sergey V.; Jiang, Yong; Hirshfield, Jay L.

    2017-03-01

    Initial results are presented for the development of a CW highly-efficient RF source needed for operation of a future electron-ion collider. The design of this compact multi-beam klystron yields high efficiency (above 70%) for the power output of 125 kW at 952.6 MHz. The klystron is to work for the RF systems for ion acceleration in the polarized Medium-energy Electron Ion Collider as being developed at Thomas Jefferson National Accelerator Facility.

  18. Secondary electron emission characteristics of ion-textured copper and high-purity isotropic graphite surfaces

    Science.gov (United States)

    Curren, A. N.; Jensen, K. A.

    1984-01-01

    Experimentally determined values of true secondary electron emission and relative values of reflected primary electron yield for untreated and ion textured oxygen free high conductivity copper and untreated and ion textured high purity isotropic graphite surfaces are presented for a range of primary electron beam energies and beam impingement angles. This investigation was conducted to provide information that would improve the efficiency of multistage depressed collectors (MDC's) for microwave amplifier traveling wave tubes in space communications and aircraft applications. For high efficiency, MDC electrode surfaces must have low secondary electron emission characteristics. Although copper is a commonly used material for MDC electrodes, it exhibits relatively high levels of secondary electron emission if its surface is not treated for emission control. Recent studies demonstrated that high purity isotropic graphite is a promising material for MDC electrodes, particularly with ion textured surfaces. The materials were tested at primary electron beam energies of 200 to 2000 eV and at direct (0 deg) to near grazing (85 deg) beam impingement angles. True secondary electron emission and relative reflected primary electron yield characteristics of the ion textured surfaces were compared with each other and with those of untreated surfaces of the same materials. Both the untreated and ion textured graphite surfaces and the ion treated copper surface exhibited sharply reduced secondary electron emission characteristics relative to those of untreated copper. The ion treated graphite surface yielded the lowest emission levels.

  19. Determination of nitric oxide in purified air and high purity nitrogen gases with computer-controlled second derivative spectrometer

    National Research Council Canada - National Science Library

    Soichi OTSUKA; Takahiro YAMAMOTO; Kazuhiko SAKAMOTO; Issei IWAMOTO; Naoomi YAMAKI; Takashi KIMOTO

    1984-01-01

      Nitric oxide impurity in purified air and high purity nitrogen gases, which causes uncertain errors in setting zero level of a nitrogen oxides analyzer, was determined with a newly developed computer...

  20. Gain limits of a Thick GEM in high-purity Ne, Ar and Xe

    CERN Document Server

    Miyamoto, J; Peskov, V

    2010-01-01

    The dependence of the avalanche charge gain in Thick Gas Electron Multipliers (THGEM) on the purity of Ne, Ar and Xe filling gases was investigated. The gain, measured with alpha-particles in standard conditions (atmospheric pressure, room temperature), was found to considerably drop in gases purified by non-evaporable getters. On the other hand, small N2 admixtures to noble gases resulted in high reachable gains. The results are of general relevance in the operation of gas-avalanche detectors in noble gases, particularly that of two-phase cryogenic detectors for rare events.

  1. Influence of Trace Elements on Hot Ductility of an Ultra High Purity Invar Alloy

    OpenAIRE

    Perrot-Simonetta, M.; Kobylanski, A.

    1995-01-01

    Like steels, austenitic INVAR alloys Fe-Ni 36 % show a large ductility trough between 500°C and 1100°C. To understand hot brittleness mechanisms and especially trace element effects, synthetic alloys were prepared using ultra-high purity iron and nickel doped with selected amounts of carbon, sulphur, boron, aluminium, and nitrogen. Four kinds of synthetic alloys were studied to establish the intrinsic influence of sulphur, the combined effects of sulphur and precipitates such AlN or BN, and t...

  2. Easy growth of undoped and doped tungsten oxide nanowires with high purity and orientation

    Science.gov (United States)

    Liu, Kun; Foord, David T.; Scipioni, Lawrence

    2005-01-01

    An economic method is presented to grow undoped/doped tungsten oxide nanowires with high purity and erect orientation, simply by heating a tungsten filament in a vacuum chamber with some room air leakage. Tungsten oxide nanowires were studied using scanning electron microscopy (SEM), energy dispersion x-ray spectroscopy (EDS) and transmission electron microscopy (TEM). Wires are found standing straight and clean on the filament, {\\sim }30 nm in diameter and up to a few tens of micrometres long. The composition along the wire is uniform for all elements including dopants.

  3. Experimental research of phase transitions in a melt of high-purity aluminum

    Science.gov (United States)

    Vorontsov, V. B.; Pershin, V. K.

    2017-12-01

    This scientific work is devoted to the studying of the genetic connection structures of solid and liquid phases. In this paper Fourier analysis of acoustic emission (AE) signals accompanying heating of high purity aluminum from the melting point up to 860 °C was performed. The experimental data allowed to follow the dynamics of disorder zones in the melt with increasing melt temperature up to their complete destruction. The presented results of spectral analysis of the signals were analyzed from the standpoint of the theory of cluster melting metals.

  4. Scalable preparation of high purity rutin fatty acid esters following enzymatic synthesis

    DEFF Research Database (Denmark)

    Lue, Bena-Marie; Guo, Zheng; Xu, Xuebing

    2010-01-01

    Investigations into expanded uses of modified flavonoids are often limited by the availability of these high purity compounds. As such, a simple, effective and relatively fast method for isolation of gram quantities of both long and medium chain fatty acid esters of rutin following scaled-up bios...... following a two-step solvent purification procedure whereby excess fatty acid substrate was first removed in a heptane/water (4:1, v/v) system, followed by selective ester extraction using an ethyl acetate/water system (1:6, v/v) at elevated temperature....

  5. SIMULTANEOUS PRODUCTION OF HIGH-PURITY HYDROGEN AND SEQUESTRATION-READY CO2 FROM SYNGAS

    Energy Technology Data Exchange (ETDEWEB)

    Linda Denton; Hana Lorethova; Tomasz Wiltowski; Court Moorefield; Parag Kulkarni; Vladimir Zamansky; Ravi Kumar

    2003-12-01

    This final report summarizes the progress made on the program ''Simultaneous Production of High-Purity Hydrogen and Sequestration-Ready CO{sub 2} from Syngas (contract number DE-FG26-99FT40682)'', during October 2000 through September of 2003. GE Energy and Environmental Research (GE-EER) and Southern Illinois University (SIU) at Carbondale conducted the research work for this program. This program addresses improved methods to efficiently produce simultaneous streams of high-purity hydrogen and separated carbon dioxide from synthesis gas (syngas). The syngas may be produced through either gasification of coal or reforming of natural gas. The process of production of H{sub 2} and separated CO{sub 2} utilizes a dual-bed reactor and regenerator system. The reactor produces hydrogen and the regenerator produces separated CO{sub 2}. The dual-bed system can be operated under either a circulating fluidized-bed configuration or a cyclic fixed-bed configuration. Both configurations were evaluated in this project. The experimental effort was divided into lab-scale work at SIU and bench-scale work at GE-EER. Tests in a lab-scale fluidized bed system demonstrated the process for the conversion of syngas to high purity H{sub 2} and separated CO{sub 2}. The lab-scale system generated up to 95% H{sub 2} (on a dry basis). Extensive thermodynamic analysis of chemical reactions between the syngas and the fluidized solids determined an optimum range of temperature and pressure operation, where the extent of the undesirable reactions is minimum. The cycling of the process between hydrogen generation and oxygen regeneration has been demonstrated. The fluidized solids did not regenerate completely and the hydrogen purity in the reuse cycle dropped to 70% from 95% (on a dry basis). Changes in morphology and particle size may be the most dominant factor affecting the efficiency of the repeated cycling between hydrogen production and oxygen regeneration. The concept of

  6. Synthesis of High-Purity SnO2 Nanobelts by Using Exothermic Reaction

    Directory of Open Access Journals (Sweden)

    Guodong Zhang

    2011-01-01

    Full Text Available This paper presents a new method to synthesize high-purity single-crystalline SnO2 nanobelts with rutile structure. The purity, morphology, crystal structure, and sizes of the as-grown SnO2 nanobelts are characterized by X-ray diffraction, energy-dispersive X-ray analysis, scanning electron microscopy, transmission electron microscopy, and Raman-scattering spectroscopy. The scanning electron microscopy and transmission electron microscopy reveal tetragonal SnO2 nanobelts of 50–120 nm in width, 20–50 nm in thickness, and 2–10 μm in length. The three observed Raman peaks at 475, 633, and 774 cm−1 indicate the typical rutile structure of the SnO2, which is in agreement with the X-ray diffraction results, and other peaks of impurity are not found. High-resolution transmission electron microscopy demonstrates that the nanobelts have a high degree of crystallinity, without typical imperfects in it. And the growth mechanism of the SnO2 nanobelts is discussed.

  7. Modeling of a CW Nd:YVO4 laser longitudinally pumped by high power VCSEL modules at 808 nm

    Science.gov (United States)

    Alimohammadian, E.; Major, A.

    2014-02-01

    In this work longitudinal pumping of a continuous wave (CW) Nd:YVO4 laser by high power VCSEL modules was numerically studied. Two VCSEL pump modules (6 W and 15 W) were compared. The maximum output power from a Nd:YVO4 crystal using these pump modules was calculated to be 2.5 W and 6 W, respectively, using a 10 % output coupler. The slope and optical-to-optical efficiencies in both cases were around 47% and 40%, respectively. The performance of Nd:YVO4 crystal was found to be better than that of Nd:YAG crystal. Our numerical results indicate that VCSELs can serve as efficient pump sources for the end-pumped CW Nd:YVO4 lasers.

  8. Device to generate high purity hydroxide solution in-line for ion chromatography.

    Science.gov (United States)

    Masunaga, Hiroto; Higo, Yuji; Ishii, Mizuo; Maruyama, Noboru; Yamazaki, Shigeo

    2016-05-06

    Herein, we report a new device that generates a high-purity hydroxide solution in line. The device's container has three compartments that are isolated from each other by two cation exchange (CE) membranes. In each end of the container, an electrode is installed. The three compartments are filled with ion exchange resins. A bipolar boundary is a composite boundary comprising anion- and cation-exchangers. This device has two bipolar boundaries, which are used to separate the location of hydroxide solution generation from the location where water is electrolyzed. Therefore, it can produce high-purity hydroxide solutions that are free from gases and anionic impurities. The hydroxide solution is generated on the basis of an electrokinetic phenomenon at the surfaces of ion-exchange resins and membranes in an electric field; NaOH concentration can be controlled at rates from 0.01 to 100mM per 1mL/min by adjusting the electrical current (0-200mA) applied to the device. As the generated solution is used as an eluent for a suppressed anion chromatography, the electrical conductivity of the effluent from the suppressor is as low as that of ultra-pure water. Thus, the noise of the base-line electrical conductivity is improved, and so the detection limit of anions on the sub-ng/mL order can be achieved. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. A solvent-extraction module for cyclotron production of high-purity technetium-99m.

    Science.gov (United States)

    Martini, Petra; Boschi, Alessandra; Cicoria, Gianfranco; Uccelli, Licia; Pasquali, Micòl; Duatti, Adriano; Pupillo, Gaia; Marengo, Mario; Loriggiola, Massimo; Esposito, Juan

    2016-12-01

    The design and fabrication of a fully-automated, remotely controlled module for the extraction and purification of technetium-99m (Tc-99m), produced by proton bombardment of enriched Mo-100 molybdenum metallic targets in a low-energy medical cyclotron, is here described. After dissolution of the irradiated solid target in hydrogen peroxide, Tc-99m was obtained under the chemical form of 99mTcO4-, in high radionuclidic and radiochemical purity, by solvent extraction with methyl ethyl ketone (MEK). The extraction process was accomplished inside a glass column-shaped vial especially designed to allow for an easy automation of the whole procedure. Recovery yields were always >90% of the loaded activity. The final pertechnetate saline solution Na99mTcO4, purified using the automated module here described, is within the Pharmacopoeia quality control parameters and is therefore a valid alternative to generator-produced 99mTc. The resulting automated module is cost-effective and easily replicable for in-house production of high-purity Tc-99m by cyclotrons. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Characterization of high purity lycopene from tomato wastes using a new pressurized extraction approach.

    Science.gov (United States)

    Naviglio, Daniele; Caruso, Tonino; Iannece, Patrizia; Aragòn, Alejandro; Santini, Antonello

    2008-08-13

    In this paper, a method for the extraction of high purity lycopene from tomato wastes is presented. The method is based on a pressurized extraction that uses the Extractor Naviglio, and it is performed in the 0.7-0.9 MPa range. Tomato skin, the byproduct deriving from manufacturing of tomato, in a water dispersion, are used as starting material. Lycopene is transferred, for the effect of the high pressure used, in the form of molecular aggregates into the water as a dispersion, while apolar compounds remain in the matrix. The aggregates are easily purified in a single subsequent step by using methanol, thus, obtaining lycopene at 98% chromatographic purity or higher. A new stationary phase, phenyl-hexyl silicone, and a simple water/acetonitrile gradient were used for HPLC analysis of lycopene. The extract was characterized by UV-Vis spectrophotometry, (1)H NMR, (13)C NMR, and electrospray ionization mass spectrometry. An average recovery of 2.8 mg lycopene/kg tomato waste can be obtained after 4 hours of extraction and using tap water as the extracting liquid. The recovery percentage was of about 10%. The exhausted tomato byproduct can be easily dried and used in agriculture or as feeding for animals.

  11. Effect of initial grain size on dynamic recrystallization in high purity austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    El Wahabi, M. [Centre SMS, CNRS UMR 5146, Ecole Nationale Superieure des Mines de Saint-Etienne, 158, cours Fauriel-42023, Saint-Etienne Cedex 2 (France); Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, ETSEIB - Universidad Politecnica de Cataluna, Av. Diagonal 647, 08028-Barcelona (Spain); Gavard, L. [Centre SMS, CNRS UMR 5146, Ecole Nationale Superieure des Mines de Saint-Etienne, 158, cours Fauriel-42023, Saint-Etienne Cedex 2 (France); Montheillet, F. [Centre SMS, CNRS UMR 5146, Ecole Nationale Superieure des Mines de Saint-Etienne, 158, cours Fauriel-42023, Saint-Etienne Cedex 2 (France); Cabrera, J.M. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, ETSEIB - Universidad Politecnica de Cataluna, Av. Diagonal 647, 08028-Barcelona (Spain)]. E-mail: jose.maria.cabrera@upc.edu; Prado, J.M. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, ETSEIB - Universidad Politecnica de Cataluna, Av. Diagonal 647, 08028-Barcelona (Spain)

    2005-10-15

    The influence of initial microstructure on discontinuous dynamic recrystallization (DDRX) has been investigated by using high purity and ultra high purity austenitic stainless steels with various initial grain sizes. After uniaxial compression tests at constant strain rates and various temperatures, the steady state microstructure or the state corresponding to the maximum strain ({epsilon} = 1) attained in the test was analyzed by scanning electron microscopy aided with automated electron back scattering diffraction. Recrystallized grain size d {sub rec} and twin boundary fraction f {sub TB} measurements were carried out. The mechanical behavior was also investigated by comparing experimental stress-strain curves with various initial grain sizes. DDRX kinetics was described by the classical Avrami equation. It was concluded that larger initial grain sizes promoted a delay in the DDRX onset in the two alloys. It was also observed that the softening process progressed faster for smaller initial grain sizes. The effect of initial grain size is larger in the HP material and becomes more pronounced at low temperature.

  12. Micromechanisms of deformation in high-purity hot-pressed alumina

    Energy Technology Data Exchange (ETDEWEB)

    Staehler, J.M.; Predebon, W.W.; Subhash, G. [Michigan Technological Univ., Houghton, MI (United States). Dept. of Mechanical Engineering and Engineering Mechanics; Pletka, B.J. [Metallurgical and Materials Engineering Dept., Michigan Technological Univ., Houghton, MI (United States)

    2000-10-31

    A high-strength aluminum oxide was produced by vacuum hot pressing high-purity, submicron-size alumina powders. The uniaxial compressive fracture strength was strongly strain-rate sensitive and varied from 5.5 GPa at 10{sup -4} s{sup -1} to 8.3 GPa at 10{sup 3} s{sup -1}. A Hugoniot elastic limit of about 11.9 GPa was determined from flyer plate impact tests. The deformation/fracture process was examined using both uniaxial stress and uniaxial strain conditions. Under a uniaxial stress condition, microplasticity was observed in the form of aligned dislocations that appeared similar to shear bands in metals. Under a uniaxial strain condition, extensive dislocation activity, grain boundary microcracking and occasional twins were observed. Based on the experimental results and microscopic observations, possible mechanisms responsible for the observed high strength and high strain-rate sensitivity in this alumina are discussed. (orig.)

  13. Production of carbon monoxide-free hydrogen and helium from a high-purity source

    Science.gov (United States)

    Golden, Timothy Christopher [Allentown, PA; Farris, Thomas Stephen [Bethlehem, PA

    2008-11-18

    The invention provides vacuum swing adsorption processes that produce an essentially carbon monoxide-free hydrogen or helium gas stream from, respectively, a high-purity (e.g., pipeline grade) hydrogen or helium gas stream using one or two adsorber beds. By using physical adsorbents with high heats of nitrogen adsorption, intermediate heats of carbon monoxide adsorption, and low heats of hydrogen and helium adsorption, and by using vacuum purging and high feed stream pressures (e.g., pressures of as high as around 1,000 bar), pipeline grade hydrogen or helium can purified to produce essentially carbon monoxide -free hydrogen and helium, or carbon monoxide, nitrogen, and methane-free hydrogen and helium.

  14. High-Purity Semiconducting Single-Walled Carbon Nanotubes: A Key Enabling Material in Emerging Electronics.

    Science.gov (United States)

    Lefebvre, Jacques; Ding, Jianfu; Li, Zhao; Finnie, Paul; Lopinski, Gregory; Malenfant, Patrick R L

    2017-10-17

    Semiconducting single-walled carbon nanotubes (sc-SWCNTs) are emerging as a promising material for high-performance, high-density devices as well as low-cost, large-area macroelectronics produced via additive manufacturing methods such as roll-to-roll printing. Proof-of-concept demonstrations have indicated the potential of sc-SWCNTs for digital electronics, radiofrequency circuits, radiation hard memory, improved sensors, and flexible, stretchable, conformable electronics. Advances toward commercial applications bring numerous opportunities in SWCNT materials development and characterization as well as fabrication processes and printing technologies. Commercialization in electronics will require large quantities of sc-SWCNTs, and the challenge for materials science is the development of scalable synthesis, purification, and enrichment methods. While a few synthesis routes have shown promising results in making near-monochiral SWCNTs, gram quantities are available only for small-diameter sc-SWCNTs, which underperform in transistors. Most synthesis routes yield mixtures of SWCNTs, typically 30% metallic and 70% semiconducting, necessitating the extraction of sc-SWCNTs from their metallic counterparts in high purity using scalable postsynthetic methods. Numerous routes to obtain high-purity sc-SWCNTs from raw soot have been developed, including density-gradient ultracentrifugation, chromatography, aqueous two-phase extraction, and selective DNA or polymer wrapping. By these methods (termed sorting or enrichment), >99% sc-SWCNT content can be achieved. Currently, all of these approaches have drawbacks and limitations with respect to electronics applications, such as excessive dilution, expensive consumables, and high ionic impurity content. Excess amount of dispersant is a common challenge that hinders direct inclusion of sc-SWCNTs into electronic devices. At present, conjugated polymer extraction may represent the most practical route to sc-SWCNTs. By the use of

  15. Physical and mechanical metallurgy of high purity Nb for accelerator cavities

    Directory of Open Access Journals (Sweden)

    T. R. Bieler

    2010-03-01

    Full Text Available In the past decade, high Q values have been achieved in high purity Nb superconducting radio frequency (SRF cavities. Fundamental understanding of the physical metallurgy of Nb that enables these achievements is beginning to reveal what challenges remain to establish reproducible and cost-effective production of high performance SRF cavities. Recent studies of dislocation substructure development and effects of recrystallization arising from welding and heat treatments and their correlations with cavity performance are considered. With better fundamental understanding of the effects of dislocation substructure evolution and recrystallization on electron and phonon conduction, as well as the interior and surface states, it will be possible to design optimal processing paths for cost-effective performance using approaches such as hydroforming, which minimizes or eliminates welds in a cavity.

  16. Effect of microplastic deformation on the electron ultrasonic absorption in high-purity molybdenum monocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Pal' -Val' , P.P.; Kaufmann, Kh.J.

    1983-03-01

    The low temperature (100-6 K) linear absorption of ultrasound (88 kHz) by high purity molybdenum single crystals have been studied. Both unstrained samples and samples sub ected to microplastic deformation (epsilon<=0.45%) were used. Unstrained samples displayed at T<30 K a rapid increase in the absorption with lowering temperature which is interpreted as an indication of electron viscosity due to electron-phonon collisions. After deformation this part of absorption disappeared. This seems to suggest that microplastic deformation brings about in the crystal a sufficiently large number of defects that can compete with phonons in restricting the electron mean free path. A low temperature dynamic annealing has been revealed in strained samples, that is almost complete recovery of the absorption nature under irradiation with high amplitude sound, epsilon/sub 0/ approximately 10/sup -4/, during 10 min, at 6 K. A new relaxation peak of absorption at 10 K has been found in strained samples.

  17. A Strontium- and Chlorine-Free Pyrotechnic Illuminant of High Color Purity.

    Science.gov (United States)

    Klapötke, Thomas M; Rusan, Magdalena; Stierstorfer, Joerg; Sabatini, Jesse; Glueck, Johann

    2017-11-16

    The need to develop a red-light-emitting pyrotechnic illuminant has garnered interest from the pyrotechnics community due to potential Environmental Protection Agency (EPA) regulations of strontium and chlorinated organic materials. To address these environmental regulatory concerns, the development of lithium-based red-light-emitting pyrotechnic compositions of high purity and color is described. These formulations do not contain strontium or chlorinated organic materials. Rather, the disclosed formulations are based on a non-hygroscopic dilithium high-nitrogen salt which serves as both the oxidizer and red colorant. These formulations are likely to draw interest from the civilian fireworks and military pyrotechnics communities for further development; both of whom have a vested interest in the development of environmentally conscious formulations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. The importance of Soret transport in the production of high purity silicon for solar cells

    Science.gov (United States)

    Srivastava, R.

    1985-01-01

    Temperature-gradient-driven diffusion, or Soret transport, of silicon vapor and liquid droplets is analyzed under conditions typical of current production reactors for obtaining high purity silicon for solar cells. Contrary to the common belief that Soret transport is negligible, it is concluded that some 15-20 percent of the silicon vapor mass flux to the reactor walls is caused by the high temperature gradients that prevail inside such reactors. Moreover, since collection of silicon is also achieved via deposition of silicon droplets onto the walls, the Soret transport mechanism becomes even more crucial due to size differences between diffusing species. It is shown that for droplets in the 0.01 to 1 micron diameter range, collection by Soret transport dominates both Brownian and turbulent mechanisms.

  19. High purity polyimide analysis by solid sampling graphite furnace atomic absorption spectrometry

    Science.gov (United States)

    Santos, Rafael F.; Carvalho, Gabriel S.; Duarte, Fabio A.; Bolzan, Rodrigo C.; Flores, Erico M. M.

    2017-03-01

    In this work, Cr, Cu, Mn, Na and Ni were determined in high purity polyimides (99.5%) by solid sampling graphite furnace atomic absorption spectrometry (SS-GFAAS) using Zeeman effect background correction system with variable magnetic field, making possible the simultaneous measurement at high or low sensitivity. The following analytical parameters were evaluated: pyrolysis and atomization temperatures, feasibility of calibration with aqueous solution, linear calibration range, sample mass range and the use of chemical modifier. Calibration with aqueous standard solutions was feasible for all analytes. No under or overestimated results were observed and up to 10 mg sample could be introduced on the platform for the determination of Cr, Cu, Mn, Na and Ni. The relative standard deviation ranged from 3 to 20%. The limits of detection (LODs) achieved using the high sensitivity mode were as low as 7.0, 2.5, 1.7, 17 and 0.12 ng g- 1 for Cr, Cu, Mn, Na and Ni, respectively. No addition of chemical modifier was necessary, except for Mn determination where Pd was required. The accuracy was evaluated by analyte spike and by comparison of the results with those obtained by inductively coupled plasma optical emission spectrometry and inductively coupled plasma mass spectrometry after microwave-assisted digestion in a single reaction chamber system and also by neutron activation analysis. No difference among the results obtained by SS-GFAAS and those obtained by alternative analytical methods using independent techniques. SS-GFAAS method showed some advantages, such as the determination of metallic contaminants in high purity polyimides with practically no sample preparation, very low LODs, calibration with aqueous standards and determination in a wide range of concentration.

  20. Method of Preparation for High-Purity Nanocrystalline Anhydrous Cesium Perrhenate

    Directory of Open Access Journals (Sweden)

    Katarzyna Leszczyńska-Sejda

    2017-03-01

    Full Text Available This paper is devoted to the preparation of high-purity anhydrous nanocrystalline cesium perrhenate, which is applied in catalyst preparation. It was found that anhydrous cesium perrhenate with a crystal size <45 nm can be obtained using cesium ion sorption and elution using aqueous solutions of perrhenic acid with subsequent crystallisation, purification, and drying. The following composition of the as-obtained product was reported: 34.7% Cs; 48.6% Re and <2 ppm Bi; <3 ppm Zn; <2 ppm As; <10 ppm Ni; < 3 ppm Mg; <5 ppm Cu; <5 ppm Mo; <5 ppm Pb; <10 ppm K; <2 ppm Na; <5 ppm Ca; <3 ppm Fe.

  1. Synthesis of Magnetite Nanoparticles by Top-Down Approach from a High Purity Ore

    Directory of Open Access Journals (Sweden)

    Gayan Priyadarshana

    2015-01-01

    Full Text Available This study attempts to synthesize magnetite nanoparticles from a high purity natural iron oxide ore found in Panvila, Sri Lanka, following a novel top-down approach. Powder X-Ray diffraction, elemental analysis, and chemical analysis data confirmed the ore to be exclusively magnetite with Fe2+ : Fe3+ ratio of 1 : 2. Surface modified magnetite nanoparticles were synthesized by destructuring of this ore using a top-down approach in the presence of oleic acid. These oleic acid coated nanoparticles were further dispersed in ethanol resulting in stable nanomagnetite dispersion. Interestingly, the nanoparticles demonstrated a spherical morphology with a particle size ranging from 20 to 50 nm. Magnetic force microscopic data was used to confirm the topography of the nanoparticles and to study the magnetic domain structure.

  2. Defects interaction processes in deformed high purity polycrystalline molybdenum at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Lambri, O.A., E-mail: olambri@fceia.unr.edu.ar [Laboratorio de Materiales, Escuela de Ingeniería Eléctrica, Centro de Tecnología e Investigación Eléctrica, Facultad de Ciencias Exactas, Ingeniería y Agrimensura, Universidad Nacional de Rosario – CONICET, Avda. Pellegrini 250, (2000) Rosario (Argentina); Bonifacich, F.G. [Laboratorio de Materiales, Escuela de Ingeniería Eléctrica, Centro de Tecnología e Investigación Eléctrica, Facultad de Ciencias Exactas, Ingeniería y Agrimensura, Universidad Nacional de Rosario – CONICET, Avda. Pellegrini 250, (2000) Rosario (Argentina); Bozzano, P.B. [Laboratorio de Microscopía Electrónica, Unidad de Actividad Materiales, Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica e Instituto Sábato – Universidad Nacional de San Martín, Avda. Gral. Paz 1499, (1650) San Martín (Argentina); Zelada, G.I. [Laboratorio de Materiales, Escuela de Ingeniería Eléctrica, Centro de Tecnología e Investigación Eléctrica, Facultad de Ciencias Exactas, Ingeniería y Agrimensura, Universidad Nacional de Rosario – CONICET, Avda. Pellegrini 250, (2000) Rosario (Argentina); and others

    2014-10-15

    Mechanical spectroscopy (damping and elastic modulus as a function of temperature) and transmission electron microscopy studies have been performed in high purity polycrystalline molybdenum plastically deformed to different values of tensile and torsion strain. Mechanical spectroscopy measurements were performed from room temperature up to 1285 K. A relaxation peak in polycrystalline molybdenum related to the movement of dislocations into lower energy configurations near grain boundaries has been discovered to appear around 1170 K. The activation energy of the peak is 4.2 eV ± 0.5 eV. This relaxation phenomenon involves the interaction between vacancies and mobile dislocations near the grain boundaries. It should be highlighted that this relaxation process is controlled by the arrangement of vacancies and dislocations which occur at temperature below 1070 K.

  3. Automated determination of segment positions in a high-purity 32-fold segmented germanium detector

    CERN Document Server

    Miller, K L; Campbell, C; Morris, L; Müller, W F; Strahler, E A

    2002-01-01

    An automated system for determining detector segment positions in a high-purity 32-fold segmented germanium detector has been developed. To determine segment positions as they would appear in an experiment, positions must be measured while the 32-fold segmented germanium crystal is kept at liquid nitrogen temperatures. A collimated sup 5 sup 7 Co gamma-ray source is moved around the surface of the detector cryostat, and the response of the germanium crystal is measured. Motion of the source is driven by two Slo-Syn motors and BEI incremental optical encoders, which are controlled through LabVIEW programming and a National Instruments PCStep board. The collected data is analyzed to determine the position of the center of each of the 32 segments.

  4. High Purity Tungsten Spherical Particle Preparation From WC-Co Spent Hard Scrap

    Directory of Open Access Journals (Sweden)

    Han Chulwoong

    2015-06-01

    Full Text Available Tungsten carbide-cobalt hard metal scrap was recycled to obtain high purity spherical tungsten powder by a combined hydrometallurgy and physical metallurgy pathway. Selective leaching of tungsten element from hard metal scrap occurs at solid / liquid interface and therefore enlargement of effective surface area is advantageous. Linear oxidation behavior of Tungsten carbide-cobalt and the oxidized scrap is friable to be pulverized by milling process. In this regard, isothermally oxidized Tungsten carbide-cobalt hard metal scrap was mechanically broken into particles and then tungsten trioxide particle was recovered by hydrometallurgical method. Recovered tungsten trioxide was reduced to tungsten particle in a hydrogen environment. After that, tungsten particle was melted and solidified to make a spherical one by RF (Ratio Frequency thermal plasma process. Well spherical tungsten micro-particle was successfully obtained from spent scrap. In addition to the morphological change, thermal plasma process showed an advantage for the purification of feedstock particle.

  5. Assessment of radiochemical purity of [{sup 18}F]fludeoxyglucose by high pressure liquid chromatography (HPLC)

    Energy Technology Data Exchange (ETDEWEB)

    Lacerda, Aline E.; Silva, Juliana B.; Silveira, Marina B.; Ferreira, Soraya Z., E-mail: radiofarmacoscdtn@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Unidade de Pesquisa e Producao de Radiofarmacos

    2011-07-01

    The quality control of [{sup 18}F]fludeoxyglucose ({sup 18}FDG) has received attention due to its increasing clinical use. Although the quality requirements of {sup 18}FDG are established in various pharmacopoeia, the suitability of all testing methods used should be verified under actual conditions of use and documented. The aim of this study was to develop a high pressure liquid chromatography (HPLC) method for radiochemical purity evaluation of {sup 18}FDG, based on pharmacopoeia references, and to verify its suitability for routine quality control in our centre. HPLC analysis was performed with an Agilent HPLC. {sup 18}FDG and impurities were separated on an anion-exchange column by isocratic elution with 0.1 M NaOH as the mobile phase. Detection was accomplished with refractive index and NaI (Tl) scintillation detectors. The flow rate of the mobile phase was set at 0.8 mL/min and the column temperature was kept at 35 deg C. Specificity, linearity, precision and robustness were assessed to verify if the method was adequate for its intended purpose. Retention time of {sup 18}FDG was not affected by the presence of other components of the formulation and a good peak resolution was achieved. The analytical curve of {sup 18}FDG was linear, with a correlation coefficient value of 0.9995. Intraday repeatable precision, reported as the relative standard deviation, was 0.11%. Analytical procedure remained unaffected by small variations in mobile phase flow rate. Results evidenced that HPLC is suitable for radiochemical purity evaluation of {sup 18}FDG, considering operational conditions of our laboratory. (author)

  6. Production of low-expressing recombinant cationic biopolymers with high purity.

    Science.gov (United States)

    Chen, Xuguang; Nomani, Alireza; Patel, Niket; Hatefi, Arash

    2017-06-01

    The growing complexity of recombinant biopolymers for delivery of bioactive agents requires the ability to control the biomaterial structure with high degree of precision. Genetic engineering techniques have provided this opportunity to synthesize biomaterials in an organism such as E. coli with full control over their lengths and sequences. One class of such biopolymers is recombinant cationic biopolymers with applications in gene delivery, regenerative medicine and variety of other biomedical applications. Unfortunately, due to their highly cationic nature and complex structure, their production in E. coli expression system is marred by low expression yield which in turn complicates the possibility of obtaining pure biopolymer. SlyD and ArnA endogenous E. coli proteins are considered the major culprits that copurify with the low-expressing biopolymers during the metal affinity chromatography. Here, we compared the impact of different parameters such as the choice of expression hosts as well as metal affinity columns in order to identify the most effective approach in obtaining highly pure recombinant cationic biopolymers with acceptable yield. The results of this study showed that by using E. coli BL21(DE3) LOBSTR strain and in combination with our developed stringent expression and Ni-NTA purification protocols highly pure products in one purification step (>99% purity) can be obtained. This approach could be applied to the production of other complex and potentially toxic biopolymers with wide range of applications in biomedicine. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. A Green and Solvent-Free Process for Preparation of High- Purity ...

    African Journals Online (AJOL)

    purity (–)-borneol from leaves of Blumea balsamifera (L.) DC.. Methods: An improved hydrodistillation (IHD) equipped with a vertical condenser tube was designed for extracting the volatiles (crude (–)-borneol) without solvent, and comparing with ...

  8. Characterization of high-purity niobium structures fabricated using the electron beam melting process

    Science.gov (United States)

    Terrazas Najera, Cesar Adrian

    Additive Manufacturing (AM) refers to the varied set of technologies utilized for the fabrication of complex 3D components from digital data in a layer-by-layer fashion. The use of these technologies promises to revolutionize the manufacturing industry. The electron beam melting (EBM) process has been utilized for the fabrication of fully dense near-net-shape components from various metallic materials. This process, catalogued as a powder bed fusion technology, consists of the deposition of thin layers (50 - 120microm) of metallic powder particles which are fused by the use of a high energy electron beam and has been commercialized by Swedish company Arcam AB. Superconducting radio frequency (SRF) cavities are key components that are used in linear accelerators and other light sources for studies of elemental physics. Currently, cavity fabrication is done by employing different forming processes including deep-drawing and spinning. In both of the latter techniques, a feedstock high-purity niobium sheet with a thickness ranging from 3-4 mm is mechanically deformed and shaped into the desired geometry. In this manner, half cavities are formed that are later joined by electron beam welding (EBW). The welding step causes variability in the shape of the cavity and can also introduce impurities at the surface of the weld interface. The processing route and the purity of niobium are also of utmost importance since the presence of impurities such as inclusions or defects can be detrimental for the SRF properties of cavities. The focus of this research was the use of the EBM process in the manufacture of high purity niobium parts with potential SRF applications. Reactor grade niobium was plasma atomized and used as the precursor material for fabrication using EBM. An Arcam A2 system was utilized for the fabrication. The system had all internal components of the fabrication chamber replaced and was cleaned to prevent contamination of niobium powder. A mini-vat, developed at

  9. Design of spherical electron gun for ultra high frequency, CW power inductive output tube

    Energy Technology Data Exchange (ETDEWEB)

    Kaushik, Meenu, E-mail: mkceeri@gmail.com; Joshi, L. M., E-mail: lmj1953@gmail.com [Microwave Tubes Division, CSIR-Central Electronics Engineering Research Institute (CEERI), Pilani, Rajasthan (India); Academy of Scientific and Innovative Research (AcSIR), New Delhi (India)

    2016-03-09

    Inductive Output Tube (IOT) is an amplifier that usually operates in UHF range. It is an electron tube whose basic structure is similar to conventional vacuum devices. This device is widely used in broadcast applications but is now being explored for scientific applications also specifically, particle accelerators and fusion plasma heating purposes. The paper describes the design approach of a spherical gridded electron gun of a 500 MHz, 100 kW CW power IOT. The electron gun structure has been simulated and optimized for operating voltage and current of 40kV and 3.5 A respectively. The electromagnetic analysis of this spherical electron gun has been carried out in CST and TRAK codes.

  10. Influence of Ta Content in High Purity Niobium on Cavity Performance Preliminary Results*

    CERN Document Server

    Kneisel, P

    2004-01-01

    In a previous paper* a program designed to study the influence of the residual tantalum content on the superconducting properties of pure niobium metal for RF cavities was outlined. The main rationale for this program was based on a potential cost reduction for high purity niobium, if a less strict limit on the chemical specification for Ta content, which is not significantly affecting the RRR–value, could be tolerated for high performance cavities. Four ingots with different Ta contents have been melted and transformed into sheets. In each manufacturing step the quality of the material has been monitored by employing chemical analysis, neutron activation analysis, thermal conductivity measurements and evaluation of the mechanical properties. The niobium sheets have been scanned for defects by an eddy current device. From three of the four ingots—Ta contents 100, 600 and 1,200 wppm—two single cell cavities each of the CEBAF variety have been fabricated and a series of tests on each ...

  11. Electron spin resonance spectroscopy of high purity crystals at millikelvin temperatures

    Science.gov (United States)

    Farr, Warrick G.; Creedon, Daniel L.; Goryachev, Maxim; Benmessai, Karim; Tobar, Michael E.

    2013-12-01

    Progress in the emerging field of engineered quantum systems requires the development of devices that can act as quantum memories. The realisation of such devices by doping solid state cavities with paramagnetic ions imposes a trade-off between ion concentration and cavity coherence time. Here, we investigate an alternative approach involving interactions between photons and naturally occurring impurity ions in ultra-pure crystalline microwave cavities exhibiting exceptionally high quality factors. We implement a hybrid Whispering Gallery/Electron Spin Resonance method to perform rigorous spectroscopy of an undoped single-crystal sapphire resonator over the frequency range 8{19 GHz, and at external applied DC magnetic fields up to 0.9 T. Measurements of a high purity sapphire cooled close to 100 mK reveal the presence of Fe3+, Cr3+, and V2+ impurities. A host of electron transitions are measured and identified, including the two-photon classically forbidden quadrupole transition (Δms = 2) for Fe3+, as well as hyperfine transitions of V2+.

  12. Modelling of hydrogen permeability of membranes for high-purity hydrogen production

    Science.gov (United States)

    Zaika, Yury V.; Rodchenkova, Natalia I.

    2017-11-01

    High-purity hydrogen is required for clean energy and a variety of chemical technology processes. Different alloys, which may be well-suited for use in gas-separation plants, were investigated by measuring specific hydrogen permeability. One had to estimate the parameters of diffusion and sorption to numerically model the different scenarios and experimental conditions of the material usage (including extreme ones), and identify the limiting factors. This paper presents a nonlinear mathematical model taking into account the dynamics of sorption-desorption processes and reversible capture of diffusing hydrogen by inhomogeneity of the material’s structure, and also modification of the model when the transport rate is high. The results of numerical modelling allow to obtain information about output data sensitivity with respect to variations of the material’s hydrogen permeability parameters. Furthermore, it is possible to analyze the dynamics of concentrations and fluxes that cannot be measured directly. Experimental data for Ta77Nb23 and V85Ni15 alloys were used to test the model. This work is supported by the Russian Foundation for Basic Research (Project No. 15-01-00744).

  13. A green preparation of Mn-based product with high purity from low-grade rhodochrosite

    Science.gov (United States)

    Lian, F.; Ma, L.; Chenli, Z.; Mao, L.

    2018-01-01

    The low-grade rhodochrosite, the main resources for exploitation and applications in China, contains multiple elements such as iron, silicon, calcium and magnesium. So the conventional preparation of manganese sulphate and manganese oxide with high purity from electrolytic product is characterized by long production-cycle, high-resource input and high-pollution discharge. In our work, a sustainable preparation approach of high pure MnSO4 solution and Mn3O4 was studied by employing low-grade rhodochrosite (13.86%) as raw material. The repeated leaching of rhodochrosite with sulphuric acid was proposed in view of the same ion effect, in order to improve the solubility of Mn2+ and inhibit the dissolution of the impurities Ca2+ and Mg2+. With the aid of theoretical calculation, BaF2 was chosen to remove Ca2+ and Mg2+ completely in the process of purifying. The results showed that the impurities such as Ca2+, Mg2+, Na+ were decreased to less than 20ppm, and the Ni- and Fe- impurities were decreased to less than 1ppm, which meets the standards of high pure reagent for energy and electronic materials. The extraction ratio and the recovery ratio of manganese reached 94.3% and 92.7%, respectively. Moreover, the high pure Mn3O4 was one-step synthesized via the oxidation of MnSO4 solution with the ratios of OH-/Mn2+=2 and Mn2+/H2O2=1.03, and the recovery rate of manganese reaches 99%.

  14. Optimization of extraction of high purity all-trans-lycopene from tomato pulp waste.

    Science.gov (United States)

    Poojary, Mahesha M; Passamonti, Paolo

    2015-12-01

    The aim of this work was to optimize the extraction of pure all-trans-lycopene from the pulp fractions of tomato processing waste. A full factorial design (FFD) consisting of four independent variables including extraction temperature (30-50 °C), time (1-60 min), percentage of acetone in n-hexane (25-75%, v/v) and solvent volume (10-30 ml) was used to investigate the effects of process variables on the extraction. The absolute amount of lycopene present in the pulp waste was found to be 0.038 mg/g. The optimal conditions for extraction were as follows: extraction temperature 20 °C, time 40 min, a solvent composition of 25% acetone in n-hexane (v/v) and solvent volume 40 ml. Under these conditions, the maximal recovery of lycopene was 94.7%. The HPLC-DAD analysis demonstrated that, lycopene was obtained in the all-trans-configuration at a very high purity grade of 98.3% while the amount of cis-isomers and other carotenoids were limited. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. High Purity Germanium Detector as part of Health Canada's Mobile Nuclear Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Stocki, Trevor J.; Bouchard, Claude; Rollings, John; Boudreau, Marc-Oliver; McCutcheon- Wickham, Rory; Bergman, Lauren [Radiation Protection Bureau, Health Canada, AL6302D, 775 Brookfield Road, Ottawa, K1A 0K9 (Canada)

    2014-07-01

    In the event of a nuclear emergency on Canadian soil, Health Canada has designed and equipped two Mobile Nuclear Labs (MNLs) which can be deployed near a radiological accident site to provide radiological measurement capabilities. These measurements would help public authorities to make informed decisions for radiation protection recommendations. One of the MNLs has been outfitted with a High Purity Germanium (HPGe) detector within a lead castle, which can be used for identification as well as quantification of gamma emitting radioisotopes in contaminated soil, water, and other samples. By spring 2014, Health Canada's second MNL will be equipped with a similar detector to increase sample analysis capacity and also provide redundancy if one of the detectors requires maintenance. The Mobile Nuclear Lab (MNL) with the HPGe detector has been successfully deployed in the field for various exercises. One of these field exercises was a dirty bomb scenario where an unknown radioisotope required identification. A second exercise was an inter-comparison between the measurements of spiked soil and water samples, by two field teams and a certified laboratory. A third exercise was the deployment of the MNL as part of a full scale nuclear exercise simulating an emergency at a Canadian nuclear power plant. The lessons learned from these experiences will be discussed. (authors)

  16. MIS High-Purity Plutonium Oxide Metal Oxidation Product TS707001 (SSR123): Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Veirs, Douglas Kirk [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Stroud, Mary Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Berg, John M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Narlesky, Joshua Edward [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Worl, Laura Ann [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Max A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carillo, Alex [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-09

    A high-purity plutonium dioxide material from the Material Identification and Surveillance (MIS) Program inventory has been studied with regard to gas generation and corrosion in a storage environment. Sample TS707001 represents process plutonium oxides from several metal oxidation operations as well as impure and scrap plutonium from Hanford that are currently stored in 3013 containers. After calcination to 950°C, the material contained 86.98% plutonium with no major impurities. This study followed over time, the gas pressure of a sample with nominally 0.5 wt% water in a sealed container with an internal volume scaled to 1/500th of the volume of a 3013 container. Gas compositions were measured periodically over a six year period. The maximum observed gas pressure was 138 kPa. The increase over the initial pressure of 80 kPa was primarily due to generation of nitrogen and carbon dioxide gas in the first six months. Hydrogen and oxygen were minor components of the headspace gas. At the completion of the study, the internal components of the sealed container showed signs of corrosion, including pitting.

  17. Computational modeling of a high purity germanium (HPGe) detector using MCNPX code

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Guilherme J. de S.; Rebello, Wilson F.; Morales, Rudnei K., E-mail: guilhermeime@ime.eb.b, E-mail: rebelloime@ime.eb.b, E-mail: karam@ime.eb.b [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear; Cardoso, Domingos O.; Correa, Samanda C.A., E-mail: domin@cnen.gov.b, E-mail: scorrea@cnen.gov.b [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Silva, Ademir X. da, E-mail: ademir@nuclear.ufrj.b [Universidade Federal do Rio de Janeiro (CT/UFRJ), RJ (Brazil). Centro de Tecnologia

    2011-07-01

    The efficiency of a detection system is crucial to determine the real activity of a radioactive source. When it's possible, the system's calibration should be performed using a standard source. Unfortunately, there are only a few cases that it can be done this way, considering the difficulty of obtaining appropriate standard sources for each type of measurement. In such cases, computer simulations can be performed to assist in calculating of the efficiency of the system with a similar configuration. This work aims to create, using the MCNPX code, a computer model of a high purity germanium (HPGe) detector belonged to the Radiometry Laboratory of Instituto Militar de Engenharia (IME), adapted for the calculation of the full-energy peak efficiency of {sup 137}Cs. The model was created representing in details an experimental arrangement assembled in IME considering the HPGe detector and measuring a {sup 137}Cs source. The calculated results are being compared with those obtained experimentally and the model is in process of validation. (author)

  18. X-ray quantitative analysis on spallation response in high purity copper under sweeping detonation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang, E-mail: yangyanggroup@163.com [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); National Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081 (China); Key Laboratory of Nonferrous Metals Material Science and Engineering of Ministry of Education, Central South University, Changsha 410083 (China); Chen, Jixiong; Peng, Zhiqiang [School of Material Science and Engineering, Central South University, Changsha 410083 (China); Guo, Zhaoliang; Tang, Tiegang; Hu, Haibo [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); Hu, Yanan [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2016-06-14

    The 3-D quantitative investigation of spall behavior in high purity copper plants with different heat treatment histories was characterized using X-ray computer tomography (XRCT). The effect of shock stress and grain size on the spatial distribution and morphology of incipient spall samples were discussed. The results revealed that, in samples with similar microstructure, the ranges of void distribution decrease with the increasing of shock stress. The characteristic parameters (such as mean elongation, mean flatness and mean sphericity of voids) determined using XRCT herein as a function of shock stress and grain size. The quantitative analyses of spallation datasets render functional relationships between the microscopic parameters (like volume, frequency) of spallation voids and the microstructure. The XRCT observations show that voids are prone to coalescence in thermo-mechanical treatments (TMT) sample, while the final maximum and mean volume of void were smaller than that of annealed sample. This is due to the smaller grain size of TMT sample, which means more nucleation sites of voids, this made the voids get closer and easier to coalescence, and flat voids formed ultimately.

  19. Industrial symbiosis: high purity recovery of metals from Waelz sintering waste by aqueous SO2 solution.

    Science.gov (United States)

    Copur, Mehmet; Pekdemir, Turgay; Colak, Sabri; Künkül, Asim

    2007-10-22

    Sintering operation in the production of Zn, Cd, and Pb by Waelz process produces a powdery waste containing mainly (about 70%) ZnO, CdO, and PbO. The waste may be referred to as Waelz sintering waste (WSW). The aim of this study is to develop a process for the separation and recovery of the metals from WSW with high purities. The process is based on the dissolution of the WSW in aqueous SO2 solution. The research reported here concentrated on the effect of some important operational parameters on dissolution process. The parameters investigated and their ranges were as follows: SO(2) gas flow rate (V); 38-590 ml/min, stirring speed (W); 100-1000 rpm, reaction temperature (T); 13-60 degrees C, reaction time (t); 1-16 min, and solid-liquid ratio (S/L); 0.1-0.5 g/ml. The results showed that the dissolution rate increased with increasing W, V, and S/L and decreasing T. The best dissolution conditions were found to be V=325 ml/min, W=600 rpm, t=6 min, T=21 degrees C, and S/L=0.1g/ml. Separation of Zn from Cd involved precipitation of ZnSO3 from a mixture solution. The best pH level for the precipitation was observed to be 6.

  20. Inter-electrode charge collection in high-purity germanium detectors with amorphous semiconductor contacts

    Energy Technology Data Exchange (ETDEWEB)

    Looker, Q., E-mail: qlooker@lbl.gov [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States); Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States); Amman, M. [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States); Vetter, K. [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States); Department of Nuclear Engineering, University of California, Berkeley, CA 94720 (United States)

    2015-05-01

    High-purity germanium (HPGe) radiation detectors with segmented signal readout electrodes combine excellent energy resolution with fine spatial resolution, opening exciting possibilities in radiation imaging applications. Segmenting the electrodes provides the ability to determine the positions of radiation interactions in the detector, but it also brings potential challenges that can inhibit performance. A challenge unique to segmented electrode detectors is collection of charge carriers to the gap between adjacent electrodes rather than to the electrodes themselves, which gives a deficit in the summed energy. While amorphous semiconductor electrical contacts have enabled a simplified fabrication process capable of fine electrode segmentation, the amorphous semiconductor passivation layer between electrodes is prone to inter-electrode charge collection. This article presents a study of the impact of fabrication process parameters on the energy deficit due to inter-electrode charge collection for double-sided strip detectors. Eight double-sided strip HPGe detectors were fabricated with amorphous germanium (a-Ge) and amorphous silicon (a-Si) contacts formed by sputter deposition. Each detector was evaluated for inter-electrode charge collection performance, using as a metric the deficit in the summed signal of two adjacent electrodes. It is demonstrated that both a-Ge and a-Si contacts can be produced with nearly non-existent inter-electrode charge collection when the appropriate combination of sputter gas hydrogen content and gas pressure are selected.

  1. Leakage current in high-purity germanium detectors with amorphous semiconductor contacts

    Energy Technology Data Exchange (ETDEWEB)

    Looker, Q., E-mail: qlooker@lbl.gov [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States); Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States); Amman, M. [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States); Vetter, K. [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States); Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States)

    2015-03-21

    Amorphous semiconductor electrical contacts on high-purity Ge radiation detectors have become a valuable technology because they are simple to fabricate, result in thin dead layers, block both electron and hole injection, and can readily be finely segmented as needed for applications requiring imaging or particle tracking. Though significant numbers of detectors have been successfully produced for a variety of applications using the amorphous semiconductor contact technology, there remains a need to better understand the dependence of performance characteristics, particularly leakage current, on the fabrication process parameters so that the performance can be better optimized. To this end, we have performed a systematic study of leakage current on RF-sputter-deposited amorphous-Ge (a-Ge) and amorphous-Si (a-Si) contacts as a function of process and operational parameters including sputter gas pressure and composition, number of detector temperature cycles, and time spent at room temperature. The study focused primarily on the current resulting from electron injection at the contact. Significant findings from the study include that a-Si produces lower electron injection than a-Ge, the time the detector spends at room temperature rather than the number of temperature cycles experienced by the detector is the primary factor associated with leakage current change when the detector is warmed, and the time stability of the a-Ge contact depends on the sputter gas pressure with a higher pressure producing more stable characteristics.

  2. Synthesis of high purity monoglycerides from crude glycerol and palm stearin

    Directory of Open Access Journals (Sweden)

    Pakamas Chetpattananondh

    2008-07-01

    Full Text Available The optimum conditions for the glycerolysis of palm stearin and crude glycerol derived from biodiesel process werefound to be a reaction temperature of 200oC with a molar ratio of crude glycerol to palm stearin of 2.5:1, and a reaction timeof 20 minutes. The yield and purity of monoglycerides obtained under these conditions was satisfactory as compared withthe glycerolysis of pure glycerol. To increase the purity of monoglycerides a two-step process, removal of residual glyceroland crystallization, was proposed instead of either vacuum or molecular distillation. Residual glycerol was removed byadding hydrochloric acid followed by washing with hot water. Optimum conditions for crystallization were achieved byusing isooctane as a solvent and a turbine impeller speed of 200 rpm at a crystallization temperature of 35oC. A purity notexceeding 99 percent of monoglycerides was obtained with monopalmitin as the major product.

  3. Porous and mesh alumina formed by anodization of high purity aluminum films at low anodizing voltage

    Energy Technology Data Exchange (ETDEWEB)

    Abd-Elnaiem, Alaa M., E-mail: alaa.abd-elnaiem@science.au.edu.eg [KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Mebed, A.M. [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Department of Physics, Faculty of Science, Al-Jouf University, Sakaka 2014 (Saudi Arabia); El-Said, Waleed Ahmed [Department of Chemistry, Faculty of Science, Assiut University, Assiut 71516 (Egypt); Abdel-Rahim, M.A. [Physics Department, Faculty of Science, Assiut University, Assiut 71516 (Egypt)

    2014-11-03

    Electrochemical oxidation of high-purity aluminum (Al) films under low anodizing voltages (1–10) V has been conducted to obtain anodic aluminum oxide (AAO) with ultra-small pore size and inter-pore distance. Different structures of AAO have been obtained e.g. nanoporous and mesh structures. Highly regular pore arrays with small pore size and inter-pore distance have been formed in oxalic or sulfuric acids at different temperatures (22–50 °C). It is found that the pore diameter, inter-pore distance and the barrier layer thickness are independent of the anodizing parameters, which is very different from the rules of general AAO fabrication. The brand formation mechanism has been revealed by the scanning electron microscope study. Regular nanopores are formed under 10 V at the beginning of the anodization and then serve as a template layer dominating the formation of ultra-small nanopores. Anodization that is performed at voltages less than 5 V leads to mesh structured alumina. In addition, we have introduced a simple one-pot synthesis method to develop thin walls of oxide containing lithium (Li) ions that could be used for battery application based on anodization of Al films in a supersaturated mixture of lithium phosphate and phosphoric acid as matrix for Li-composite electrolyte. - Highlights: • We develop anodic aluminum oxide (AAO) with small pore size and inter-pore distance. • Applying low anodizing voltages onto aluminum film leads to form mesh structures. • The value of anodizing voltage (1–10 V) has no effect on pore size or inter-pore distance. • Applying anodizing voltage less than 5 V leads to mesh structured AAO. • AAO can be used as a matrix for Li-composite electrolytes.

  4. Supercapacitor Electrodes Based on High-Purity Electrospun Polyaniline and Polyaniline-Carbon Nanotube Nanofibers.

    Science.gov (United States)

    Simotwo, Silas K; DelRe, Christopher; Kalra, Vibha

    2016-08-24

    Freestanding, binder-free supercapacitor electrodes based on high-purity polyaniline (PANI) nanofibers were fabricated via a single step electrospinning process. The successful electrospinning of nanofibers with an unprecedentedly high composition of PANI (93 wt %) was made possible due to blending ultrahigh molecular weight poly(ethylene oxide) (PEO) with PANI in solution to impart adequate chain entanglements, a critical requirement for electrospinning. To further enhance the conductivity and stability of the electrodes, a small concentration of carbon nanotubes (CNTs) was added to the PANI/PEO solution prior to electrospinning to generate PANI/CNT/PEO nanofibers (12 wt % CNTs). Scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) porosimetry were conducted to characterize the external morphology of the nanofibers. The electrospun nanofibers were further probed by transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The electroactivity of the freestanding PANI and PANI/CNT nanofiber electrodes was examined using cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. Competitive specific capacitances of 308 and 385 F g(-1) were achieved for PANI and PANI-CNT based electrodes, respectively, at a current density of 0.5 A g(-1). Moreover, specific capacitance retentions of 70 and 81.4% were observed for PANI and PANI-CNT based electrodes, respectively, after 1000 cycles. The promising electrochemical performance of the fabricated electrodes, we believe, stems from the porous 3-D electrode structure characteristic of the nonwoven interconnected nanostructures. The interconnected nanofiber network facilitates efficient electron conduction while the inter- and intrafiber porosity enable excellent electrolyte penetration within the polymer matrix, allowing fast ion transport to the active sites.

  5. Nonlocal quantum macroscopic superposition in a high-thermal low-purity state.

    Science.gov (United States)

    Brezinski, Mark E; Liu, Bin

    2008-12-16

    Quantum state exchange between light and matter is an important ingredient for future quantum information networks as well as other applications. Photons are the fastest and simplest carriers of information for transmission but in general, it is difficult to localize and store photons, so usually one prefers choosing matter as quantum memory elements. Macroscopic superposition and nonlocal quantum interactions have received considerable interest for this purpose over recent years in fields ranging from quantum computers to cryptography, in addition to providing major insights into physical laws. However, these experiments are generally performed either with equipment or under conditions that are unrealistic for practical applications. Ideally, the two can be combined using conventional equipment and conditions to generate a "quantum teleportation"-like state, particularly with a very small amount of purity existing in an overall highly mixed thermal state (relatively low decoherence at high temperatures). In this study we used an experimental design to demonstrate these principles. We performed optical coherence tomography (OCT) using a thermal source at room temperatures of a specifically designed target in the sample arm. Here, position uncertainty (i.e., dispersion) was induced in the reference arm. In the sample arm (target) we placed two glass plates separated by a different medium while altering position uncertainty in the reference arm. This resulted in a chirped signal between the glass plate reflective surfaces in the combined interferogram. The chirping frequency, as measured by the fast Fourier transform (FFT), varies with the medium between the plates, which is a nonclassical phenomenon. These results are statistically significant and occur from a superposition between the glass surface and the medium with increasing position uncertainty, a true quantum-mechanical phenomenon produced by photon pressure from two-photon interference. The differences in

  6. Dielectric Performance of a High Purity HTCC Alumina at High Temperatures - a Comparison Study with Other Polycrystalline Alumina

    Science.gov (United States)

    Chen, Liangyu

    2014-01-01

    A very high purity (99.99+%) high temperature co-fired ceramic (HTCC) alumina has recently become commercially available. The raw material of this HTCC alumina is very different from conventional HTCC alumina, and more importantly there is no glass additive in this alumina material for co-firing processing. Previously, selected HTCC and LTCC (low temperature co-fired ceramic) alumina materials were evaluated at high temperatures as dielectric and compared to a regularly sintered 96% polycrystalline alumina (96% Al2O3), where 96% alumina was used as the benchmark. A prototype packaging system based on regular 96% alumina with Au thickfilm metallization successfully facilitated long term testing of high temperature silicon carbide (SiC) electronic devices for over 10,000 hours at 500 C. In order to evaluate this new high purity HTCC alumina for possible high temperature packaging applications, the dielectric properties of this HTCC alumina substrate were measured and compared with those of 96% alumina and a previously tested LTCC alumina from room temperature to 550 C at frequencies of 120 Hz, 1 KHz, 10 KHz, 100 KHz, and 1 MHz. A parallel-plate capacitive device with dielectric of the HTCC alumina and precious metal electrodes were used for measurements of the dielectric constant and dielectric loss of the co-fired alumina material in the temperature and frequency ranges. The capacitance and AC parallel conductance of the capacitive device were directly measured by an AC impedance meter, and the dielectric constant and parallel AC conductivity of the dielectric were calculated from the capacitance and conductance measurement results. The temperature and frequency dependent dielectric constant, AC conductivity, and dissipation factor of the HTCC alumina substrate are presented and compared to those of 96% alumina and a selected LTCC alumina. Other technical advantages of this new co-fired material for possible high packaging applications are also discussed.

  7. High AAV vector purity results in serotype- and tissue-independent enhancement of transduction efficiency.

    Science.gov (United States)

    Ayuso, E; Mingozzi, F; Montane, J; Leon, X; Anguela, X M; Haurigot, V; Edmonson, S A; Africa, L; Zhou, S; High, K A; Bosch, F; Wright, J F

    2010-04-01

    The purity of adeno-associated virus (AAV) vector preparations has important implications for both safety and efficacy of clinical gene transfer. Early-stage screening of candidates for AAV-based therapeutics ideally requires a purification method that is flexible and also provides vectors comparable in purity and potency to the prospective investigational product manufactured for clinical studies. The use of cesium chloride (CsCl) gradient-based protocols provides the flexibility for purification of different serotypes; however, a commonly used first-generation CsCl-based protocol was found to result in AAV vectors containing large amounts of protein and DNA impurities and low transduction efficiency in vitro and in vivo. Here, we describe and characterize an optimized, second-generation CsCl protocol that incorporates differential precipitation of AAV particles by polyethylene glycol, resulting in higher yield and markedly higher vector purity that correlated with better transduction efficiency observed with several AAV serotypes in multiple tissues and species. Vectors purified by the optimized CsCl protocol were found to be comparable in purity and functional activity to those prepared by more scalable, but less flexible serotype-specific purification processes developed for manufacture of clinical vectors, and are therefore ideally suited for pre-clinical studies supporting translational research.

  8. Cross Purposes: Love and Purity at a Puerto Rican Protestant High School

    Science.gov (United States)

    Seale-Collazo, James

    2013-01-01

    A "native" Christian ethnographer finds religious education at this church-sponsored school to pursue two distinct, and occasionally conflicting, curricula: "love" and "purity." The curriculum of love draws on what Turner called liminality and communitas in an effort to promote spiritual "encounters with…

  9. Highly efficient F-19 heteronuclear decoupling in solid-state NMR spectroscopy using supercycled refocused-CW irradiation

    DEFF Research Database (Denmark)

    Equbal, Asif; Basse, Kristoffer; Nielsen, Niels Christian

    2016-01-01

    We present heteronuclear F-19 refocused CW (rCW) decoupling pulse sequences for solid-state magic-angle- spinning NMR applications. The decoupling sequences have been designed specifically to ensure suppression of the pertinent C-13-F-19 dipolar coupling interactions while simultaneously suppress......We present heteronuclear F-19 refocused CW (rCW) decoupling pulse sequences for solid-state magic-angle- spinning NMR applications. The decoupling sequences have been designed specifically to ensure suppression of the pertinent C-13-F-19 dipolar coupling interactions while simultaneously...... of which clearly render the new rCW schemes the methods of choice for 19F decoupling in rigid, fluorinated compounds - which is further supported by a Floquet-based theoretical analysis....

  10. High-Purity Aluminum Magnet Technology for Advanced Space Transportation Systems

    Science.gov (United States)

    Goodrich, R. G.; Pullam, B.; Rickle, D.; Litchford, R. J.; Robertson, G. A.; Schmidt, D. D.; Cole, John (Technical Monitor)

    2001-01-01

    Basic research on advanced plasma-based propulsion systems is routinely focused on plasmadynamics, performance, and efficiency aspects while relegating the development of critical enabling technologies, such as flight-weight magnets, to follow-on development work. Unfortunately, the low technology readiness levels (TRLs) associated with critical enabling technologies tend to be perceived as an indicator of high technical risk, and this, in turn, hampers the acceptance of advanced system architectures for flight development. Consequently, there is growing recognition that applied research on the critical enabling technologies needs to be conducted hand in hand with basic research activities. The development of flight-weight magnet technology, for example, is one area of applied research having broad crosscutting applications to a number of advanced propulsion system architectures. Therefore, NASA Marshall Space Flight Center, Louisiana State University (LSU), and the National High Magnetic Field Laboratory (NHMFL) have initiated an applied research project aimed at advancing the TRL of flight-weight magnets. This Technical Publication reports on the group's initial effort to demonstrate the feasibility of cryogenic high-purity aluminum magnet technology and describes the design, construction, and testing of a 6-in-diameter by 12-in-long aluminum solenoid magnet. The coil was constructed in the machine shop of the Department of Physics and Astronomy at LSU and testing was conducted in NHMFL facilities at Florida State University and at Los Alamos National Laboratory. The solenoid magnet was first wound, reinforced, potted in high thermal conductivity epoxy, and bench tested in the LSU laboratories. A cryogenic container for operation at 77 K was also constructed and mated to the solenoid. The coil was then taken to NHMFL facilities in Tallahassee, FL. where its magnetoresistance was measured in a 77 K environment under steady magnetic fields as high as 10 T. In

  11. Diffusion bonding and brazing of high purity copper for linear collider accelerator structures

    Directory of Open Access Journals (Sweden)

    J. W. Elmer

    2001-05-01

    Full Text Available Diffusion bonding and brazing of high purity copper were investigated to develop procedures for joining precision machined copper components for the Next Linear Collider (NLC. Diffusion bonds were made over a range of temperatures from 400 °C to 1000 °C, under two different loading conditions [3.45 kPa (0.5 psi and 3.45 MPa (500 psi], and on two different diamond machined surface finishes. Brazes were made using pure silver, pure gold, and gold-nickel alloys, and different heating rates produced by both radiation and induction heating. Braze materials were applied by both physical vapor deposition (PVD and conventional braze alloy shims. Results of the diffusion bonding experiments showed that bond strengths very near that of the copper base metal could be made at bonding temperatures of 700 °C or higher at 3.45 MPa bonding pressure. At lower temperatures, only partial strength diffusion bonds could be made. At low bonding pressures (3.45 kPa, full strength bonds were made at temperatures of 800 °C and higher, while no bonding (zero strength was observed at temperatures of 700 °C and lower. Observations of the fracture surfaces of the diffusion bonded samples showed the effects of surface finish on the bonding mechanism. These observations clearly indicate that bonding began by point asperity contact, and flatter surfaces resulted in a higher percentage of bonded area under similar bonding conditions. Results of the brazing experiments indicated that pure silver worked very well for brazing under both conventional and high heating rate scenarios. Similarly, pure silver brazed well for both the PVD layers and the braze alloy shims. The gold and gold-containing brazes had problems, mainly due to the high diffusivity of gold in copper. These problems led to the necessity of overdriving the temperature to ensure melting, the presence of porosity in the joint, and very wide braze joints. Based on the overall findings of this study, a two

  12. Widely tunable single photon source with high purity at telecom wavelength.

    Science.gov (United States)

    Jin, Rui-Bo; Shimizu, Ryosuke; Wakui, Kentaro; Benichi, Hugo; Sasaki, Masahide

    2013-05-06

    We theoretically and experimentally investigate the spectral tunability and purity of photon pairs generated from spontaneous parametric down conversion in periodically poled KTiOPO(4) crystal with group-velocity matching condition. The numerical simulation predicts that the spectral purity can be kept higher than 0.81 when the wavelength is tuned from 1460 nm to 1675 nm, which covers the S-, C-, L-, and U-band in telecommunication wavelengths. We also experimentally measured the joint spectral intensity at 1565 nm, 1584 nm and 1565 nm, yielding Schmidt numbers of 1.01, 1.02 and 1.04, respectively. Such a photon source is useful for quantum information and communication systems.

  13. Hybrid microfiber-lithium-niobate nanowaveguide structures as high-purity heralded single-photon sources

    Science.gov (United States)

    Main, Philip; Mosley, Peter J.; Ding, Wei; Zhang, Lijian; Gorbach, Andrey V.

    2016-12-01

    We propose a compact, fiber-integrated architecture for photon-pair generation by parametric downconversion with unprecedented flexibility in the properties of the photons produced. Our approach is based on a thin-film lithium niobate nanowaveguide, evanescently coupled to a tapered silica microfiber. We demonstrate how controllable mode hybridization between the fiber and waveguide yields control over the joint spectrum of the photon pairs. We also investigate how independent engineering of the linear and nonlinear properties of the structure can be achieved through the addition of a tapered, proton-exchanged layer to the waveguide. This allows further refinement of the joint spectrum through custom profiling of the effective nonlinearity, drastically improving the purity of the heralded photons. We give details of a source design capable of generating heralded single photons in the telecom wavelength range with purity of at least 0.95, and we provide a feasible fabrication methodology.

  14. Analysis of high-purity germanium dioxide by ETV-ICP-AES with preliminary concentration of trace elements.

    Science.gov (United States)

    Medvedev, Nickolay S; Shaverina, Anastasiya V; Tsygankova, Alphiya R; Saprykin, Anatoly I

    2016-08-01

    The paper presents a combined technique of germanium dioxide analysis by inductively coupled plasma atomic emission spectrometry (ICP-AES) with preconcentration of trace elements by distilling off matrix and electrothermal (ETV) introduction of the trace elements concentrate into the ICP. Evaluation of metrological characteristics of the developed technique of high-purity germanium dioxide analysis was performed. The limits of detection (LODs) for 25 trace elements ranged from 0.05 to 20ng/g. The accuracy of proposed technique is confirmed by "added-found" («or spiking») experiment and comparing the results of ETV-ICP-AES and ICP-AES analysis of high purity germanium dioxide samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Methods to improve and understand the sensitivity of high purity germanium detectors for searches of rare events

    Energy Technology Data Exchange (ETDEWEB)

    Volynets, Oleksandr

    2012-07-27

    Observation of neutrinoless double beta-decay could answer fundamental questions on the nature of neutrinos. High purity germanium detectors are well suited to search for this rare process in germanium. Successful operation of such experiments requires a good understanding of the detectors and the sources of background. Possible background sources not considered before in the presently running GERDA high purity germanium detector experiment were studied. Pulse shape analysis using artificial neural networks was used to distinguish between signal-like and background-like events. Pulse shape simulation was used to investigate systematic effects influencing the efficiency of the method. Possibilities to localize the origin of unwanted radiation using Compton back-tracking in a granular detector system were examined. Systematic effects in high purity germanium detectors influencing their performance have been further investigated using segmented detectors. The behavior of the detector response at different operational temperatures was studied. The anisotropy effects due to the crystallographic structure of germanium were facilitated in a novel way to determine the orientation of the crystallographic axes.

  16. Gas and RRR distribution in high purity Niobium EB welded in Ultra-High Vacuum

    Science.gov (United States)

    Anakhov, S.; Singer, X.; Singer, W.; Wen, H.

    2006-05-01

    Electron beam (EB) welding in UHV (ultra-high vacuum, 10-5÷10-8 mbar) is applied in the standard fabrication of high gradient niobium superconducting radio frequency (SRF) cavities of TESLA design. The quality of EB welding is critical for cavity performance. Experimental data of gas content (H2, O2, N2) and RRR (residual resistivity ratio) measurements in niobium (Nb) welding seams are presented. EB welding in UHV conditions allow to preserve low gas content (1÷3 wt. ppm hydrogen and 5÷7 ppm oxygen and nitrogen), essential for high values of RRR — 350÷400 units. Gas content redistribution in the electron beam welded and heat affected region take place in the welding process. Correlation between gas solubility parameters, RRR and thermal conductivity are presented. Mechanisms of gas solubility in EB welding process are discussed.

  17. Fabrication process development for high-purity germanium radiation detectors with amorphous semiconductor contacts

    Science.gov (United States)

    Looker, Quinn

    High-purity germanium (HPGe) radiation detectors are well established as a valuable tool in nuclear science, astrophysics, and nuclear security applications. HPGe detectors excel in gamma-ray spectroscopy, offering excellent energy resolution with large detector sizes for high radiation detection efficiency. Although a robust fabrication process has been developed, improvement is needed, especially in developing electrical contact and surface passivation technology for position-sensitive detectors. A systematic study is needed to understand how the detector fabrication process impacts detector performance and reliability. In order to provide position sensitivity, the electrical contacts are segmented to form multiple electrodes. This segmentation creates new challenges in the fabrication process and warrants consideration of additional detector effects related to the segmentation. A key area of development is the creation of the electrical contacts in a way that enables reliable operation, provides low electronic noise, and allows fine segmentation of electrodes, giving position sensitivity for radiation interactions in the detector. Amorphous semiconductor contacts have great potential to facilitate new HPGe detector designs by providing a thin, high-resistivity surface coating that is the basis for electrical contacts that block both electrons and holes and can easily be finely segmented. Additionally, amorphous semiconductor coatings form a suitable passivation layer to protect the HPGe crystal surface from contamination. This versatility allows a simple fabrication process for fully passivated, finely segmented detectors. However, the fabrication process for detectors with amorphous semiconductors is not as highly developed as for conventional technologies. The amorphous semiconductor layer properties can vary widely based on how they are created and these can translate into varying performance of HPGe detectors with these contacts. Some key challenges include

  18. Isolation of High-Purity Extracellular Vesicles by Extracting Proteins Using Aqueous Two-Phase System

    Science.gov (United States)

    Kim, Jongmin; Shin, Hyunwoo; Kim, Jiyoon; Kim, Junho; Park, Jaesung

    2015-01-01

    We present a simple and rapid method to isolate extracellular vesicles (EVs) by using a polyethylene glycol/dextran aqueous two-phase system (ATPS). This system isolated more than ~75% of melanoma-derived EVs from a mixture of EVs and serum proteins. To increase the purity of EVs, a batch procedure was combined as additional steps to remove protein contaminants, and removed more than ~95% of the protein contaminants. We also performed RT-PCR and western blotting to verify the diagnostic applicability of the isolated EVs, and detected mRNA derived from melanoma cells and CD81 in isolated EVs. PMID:26090684

  19. Isolation of High-Purity Extracellular Vesicles by Extracting Proteins Using Aqueous Two-Phase System.

    Directory of Open Access Journals (Sweden)

    Jongmin Kim

    Full Text Available We present a simple and rapid method to isolate extracellular vesicles (EVs by using a polyethylene glycol/dextran aqueous two-phase system (ATPS. This system isolated more than ~75% of melanoma-derived EVs from a mixture of EVs and serum proteins. To increase the purity of EVs, a batch procedure was combined as additional steps to remove protein contaminants, and removed more than ~95% of the protein contaminants. We also performed RT-PCR and western blotting to verify the diagnostic applicability of the isolated EVs, and detected mRNA derived from melanoma cells and CD81 in isolated EVs.

  20. High purity H2 by sorption-enhanced chemical looping reforming of waste cooking oil in a packed bed reactor.

    Science.gov (United States)

    Pimenidou, P; Rickett, G; Dupont, V; Twigg, M V

    2010-12-01

    High purity hydrogen (>95%) was produced at 600 degrees C and 1 atm by steam reforming of waste cooking oil at a molar steam to carbon ratio of 4 using chemical looping, a process that features redox cycles of a Ni catalyst with the in-situ carbonation/calcination of a CO(2) sorbent (dolomite) in a packed bed reactor under alternated feedstreams of fuel-steam and air. The fuel and steam conversion were higher with the sorbent present than without it. Initially, the dolomite carbonation was very efficient (100%), and 98% purity hydrogen was produced, but the carbonation decreased to around 56% with a purity of 95% respectively in the following cycles. Reduction of the nickel catalyst occurred alongside steam reforming, water gas shift and carbonation, with H(2) produced continuously under fuel-steam feeds. Catalyst and CO(2)-sorbent regeneration was observed, and long periods of autothermal operation within each cycle were demonstrated. 2010 Elsevier Ltd. All rights reserved.

  1. High Purity Hydrogen Production with In-Situ Carbon Dioxide and Sulfur Capture in a Single Stage Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Nihar Phalak; Shwetha Ramkumar; Daniel Connell; Zhenchao Sun; Fu-Chen Yu; Niranjani Deshpande; Robert Statnick; Liang-Shih Fan

    2011-07-31

    Enhancement in the production of high purity hydrogen (H{sub 2}) from fuel gas, obtained from coal gasification, is limited by thermodynamics of the water gas shift (WGS) reaction. However, this constraint can be overcome by conducting the WGS in the presence of a CO{sub 2}-acceptor. The continuous removal of CO{sub 2} from the reaction mixture helps to drive the equilibrium-limited WGS reaction forward. Since calcium oxide (CaO) exhibits high CO{sub 2} capture capacity as compared to other sorbents, it is an ideal candidate for such a technique. The Calcium Looping Process (CLP) developed at The Ohio State University (OSU) utilizes the above concept to enable high purity H{sub 2} production from synthesis gas (syngas) derived from coal gasification. The CLP integrates the WGS reaction with insitu CO{sub 2}, sulfur and halide removal at high temperatures while eliminating the need for a WGS catalyst, thus reducing the overall footprint of the hydrogen production process. The CLP comprises three reactors - the carbonator, where the thermodynamic constraint of the WGS reaction is overcome by the constant removal of CO{sub 2} product and high purity H{sub 2} is produced with contaminant removal; the calciner, where the calcium sorbent is regenerated and a sequestration-ready CO{sub 2} stream is produced; and the hydrator, where the calcined sorbent is reactivated to improve its recyclability. As a part of this project, the CLP was extensively investigated by performing experiments at lab-, bench- and subpilot-scale setups. A comprehensive techno-economic analysis was also conducted to determine the feasibility of the CLP at commercial scale. This report provides a detailed account of all the results obtained during the project period.

  2. Dielectric Performance of High Purity HTCC Alumina at High Temperatures - A Comparison Study with Other Polycrystalline Alumina

    Science.gov (United States)

    Chen, Liang-Yu

    2012-01-01

    A very high purity (99.99+) high temperature co-fired ceramic (HTCC) alumina has recently become commercially available. The raw material of this HTCC alumina is very different from conventional HTCC alumina, and more importantly there is no glass additive in this co-fired material. Previously, selected HTCC and LTCC (low temperature co-fired ceramic) alumina materials were evaluated at high temperatures as dielectric and compared to a regularly sintered 96 polycrystalline alumina (96 Al2O3), where 96 alumina was used as the benchmark. A prototype packaging system based on regular 96 alumina with Au thick-film metallization successfully facilitated long term testing of high temperature silicon carbide (SiC) electronic devices for over 10,000 hours at 500C. In order to evaluate this new HTCC alumina for possible high temperature packaging applications, the dielectric properties of this HTCC alumina substrate were measured and compared with those of 96 alumina and a LTCC alumina from room temperature to 550C at frequencies of 120 Hz, 1 KHz, 10 KHz, 100 KHz, and 1 MHz. A parallel-plate capacitive device with dielectric of the HTCC alumina and precious metal electrodes were used for measurements of the dielectric constant and dielectric loss of the co-fired alumina material in the temperature and frequency ranges. The capacitance and AC parallel conductance of the capacitive device were directly measured by an AC impedance meter, and the dielectric constant and parallel AC conductivity of the dielectric were calculated from the capacitance and conductance measurement results. The temperature and frequency dependent dielectric constant, AC conductivity, and dissipation factor of the HTCC alumina substrate are presented and compared to those of 96 alumina. Other technical advantages of this new co-fired material for possible high packaging applications are also discussed.

  3. Production of high-purity vanadium, chromium and titanium for use in low activation materials

    Science.gov (United States)

    Murphy, D.; Butterworth, G. J.

    1992-09-01

    The presence of radiologically potent tramp elements must be strictly controlled if the intrinsic low activation properties of alloys based on vanadium and chromium are to be fully realized. In this study the incidence of critical impurity elements in commercial sources of vanadium, chromium and titanium metals and precursor compounds is investigated using techniques for trace element analysis. Maximum permitted concentrations corresponding to the attainment of the “hands-on” dose rate limit of 25 μSvh-1 after 100 yr cooling of first wall material were adopted as target values. Chromium and titanium from commercial sources are able to satisfy the purity target. Commercially available vanadium may contain unacceptable levels of Mo, Ag, Nb or Co and additional purification steps designed to remove these impurities are described.

  4. Physics design of a CW high-power proton Linac for accelerator ...

    Indian Academy of Sciences (India)

    The accelerator for ADS should have high efficiency and reliability and very low beam losses to allow hands-on maintenance. With these criteria, the beam dynamics simulations for a 1 GeV, 30 mA proton Linac has been done. The Linac consists of normal-conducting radio-frequency quadrupole (RFQ), drift tube linac (DTL) ...

  5. Advancement of High Power Quasi-CW Laser Diode Arrays For Space-based Laser Instruments

    Science.gov (United States)

    Amzajerdian, Farzin; Meadows, Byron L.; Baker, nathaniel R.; Baggott, Renee S.; Singh, Upendra N.; Kavaya, Michael J.

    2004-01-01

    Space-based laser and lidar instruments play an important role in NASA s plans for meeting its objectives in both Earth Science and Space Exploration areas. Almost all the lidar instrument concepts being considered by NASA scientist utilize moderate to high power diode-pumped solid state lasers as their transmitter source. Perhaps the most critical component of any solid state laser system is its pump laser diode array which essentially dictates instrument efficiency, reliability and lifetime. For this reason, premature failures and rapid degradation of high power laser diode arrays that have been experienced by laser system designers are of major concern to NASA. This work addresses these reliability and lifetime issues by attempting to eliminate the causes of failures and developing methods for screening laser diode arrays and qualifying them for operation in space.

  6. Mechanical energy losses in plastically deformed and electron plus neutron irradiated high purity single crystalline molybdenum at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Zelada, Griselda I. [Laboratorio de Materiales, Escuela de Ingenieria Electrica, Facultad de Ciencias Exactas, Ingenieria y Agrimensura, Universidad Nacional de Rosario, Avda. Pellegrini 250, 2000 Rosario (Argentina); Lambri, Osvaldo Agustin [Laboratorio de Materiales, Escuela de Ingenieria Electrica, Facultad de Ciencias Exactas, Ingenieria y Agrimensura, Universidad Nacional de Rosario, Avda. Pellegrini 250, 2000 Rosario (Argentina); Instituto de Fisica Rosario - CONICET, Member of the CONICET& #x27; s Research Staff, Avda. Pellegrini 250, 2000 Rosario (Argentina); Bozzano, Patricia B. [Laboratorio de Microscopia Electronica, Unidad de Actividad Materiales, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Avda. Gral. Paz 1499, 1650 San Martin (Argentina); Garcia, Jose Angel [Departamento de Fisica Aplicada II, Facultad de Ciencias y Tecnologia, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao, Pais Vasco (Spain)

    2012-10-15

    Mechanical spectroscopy (MS) and transmission electron microscopy (TEM) studies have been performed in plastically deformed and electron plus neutron irradiated high purity single crystalline molybdenum, oriented for single slip, in order to study the dislocation dynamics in the temperature range within one third of the melting temperature. A damping peak related to the interaction of dislocation lines with both prismatic loops and tangles of dislocations was found. The peak temperature ranges between 900 and 1050 K, for an oscillating frequency of about 1 Hz. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Study on the Key Technology of High Purity Strontium Titanate Powder Synthesized from Oxalic Acid Co-sediment Precipitation

    Science.gov (United States)

    Bi, Xiaoguo; Dong, Yingnan; Li, Yingjie; Niu, Wei; Tang, Jian; Ding, Shuang; Li, Meiyang

    2017-09-01

    Oxalate coprecipitation is applied in this paper, high purity titanium tetrachloride, and after the purification of strontium chloride, match with a certain concentration of solution, oxalate and strontium chloride and titanium tetrachloride in 1.005:1.000 make strontium titanium mixture ratio, slowly under 60°C to join in oxalic acid solution, aging around 4 h, get oxygen titanium strontium oxalate (SrTiO(C2O4)2 • 4H2 ) precipitation, after washing, drying and other process made oxygen titanium strontium oxalate powder.

  8. Preparation of uniform nanoparticles of ultra-high purity metal oxides, mixed metal oxides, metals, and metal alloys

    Science.gov (United States)

    Woodfield, Brian F.; Liu, Shengfeng; Boerio-Goates, Juliana; Liu, Qingyuan; Smith, Stacey Janel

    2012-07-03

    In preferred embodiments, metal nanoparticles, mixed-metal (alloy) nanoparticles, metal oxide nanoparticles and mixed-metal oxide nanoparticles are provided. According to embodiments, the nanoparticles may possess narrow size distributions and high purities. In certain preferred embodiments, methods of preparing metal nanoparticles, mixed-metal nanoparticles, metal oxide nanoparticles and mixed-metal nanoparticles are provided. These methods may provide tight control of particle size, size distribution, and oxidation state. Other preferred embodiments relate to a precursor material that may be used to form nanoparticles. In addition, products prepared from such nanoparticles are disclosed.

  9. High CW power, phase and amplitude modulatorrealized with fast ferrite phase-shifters

    CERN Document Server

    Valuch, D

    2004-01-01

    Superconducting cavity resonators are suffering from detuning effects caused by high internal electromagnetic fields (Lorentz force detuning). For classical resonators working with continuous wave signals, this detuning is static and compensated by the slow mechanical tuning system. However, pulsing of superconducting cavities, an operational mode only recently considered, results in dynamic detuning effects. New ways to handle this effect have to be found and worked out. A way to supply several superconducting cavities in the particle accelerator by one large transmitter while keeping the possibility of controlling the field in each individual cavity is shown. By introducing a fast phase and amplitude modulator into each cavity feeder line, the individual deviations of each cavity with respect to the average can be compensated in order to equalize their behaviour for the main control loop, which will compensate the global detuning of all cavities. Several types of phase and amplitude modulators suitable for ...

  10. Characterization of the optical beam emitted by high-power phase-locked arrays of diode lasers (P = 1 W CW)

    Science.gov (United States)

    Sobczak, Grzegorz; Dabrowska, ElŻbieta; Teodorczyk, Marian; Kalbarczyk, Joanna; Malag, Andrzej

    2013-07-01

    The quality of the beam emitted by high-power laser diodes is still the main disadvantage of these devices. One of the ways to improve it is to design diode as a matrix of narrow active stripes - so called: phase-locked arrays. The optical coupling which is occurs in such devices causes the emission in the form of a few almost diffraction limited beams (lobes). Unfortunately, because of temperature dependence of refractive indices this coupling often disappears at high drive currents. In this paper the CW operation (up to 4Ith) of the phase-locked semiconductor laser arrays is reported. The devices are based on asymmetric heterostructure which is designed for improving thermal and electrical resistances. The single supermode operation is obtained and the lasers are emitted up to 1 W of the optical power in CW.

  11. High-purity biodiesel production from microalgae and added-value lipid extraction: a new process.

    Science.gov (United States)

    Veillette, M; Giroir-Fendler, A; Faucheux, N; Heitz, M

    2015-01-01

    A new process was tested in order to produce and purify biodiesel from microalgae lipids and to recover unsaponifiable (added-value) lipids. This process is a two-step biodiesel production including a saponification reaction step followed by an esterification reaction step. The process includes a recovery of the unsaponified lipids between both reaction steps. Among the conditions tested, the following conditions were found to be the best: temperature for both steps (90 °C), saponification time (30 min), esterification time (30 min), sulfuric acid/potassium hydroxide (1.21, w/w), and methanol-lipid ratio (13.3 mL/g). Under these conditions, the fatty acid methyl ester (FAME) yield and the biodiesel purity were, respectively, 32% (g FAME/g lipid) and 77% (g FAME/g biodiesel). This study also showed that the two-step biodiesel process allows a FAME mass composition rich in palmitate (27.9-29.4 wt%), palmitoleate (24.9-26.0 wt%), elaidate (14.8-15.2 wt%), and myristate (12.1-13.0 wt%).

  12. QEPAS based ppb-level detection of CO and N2O using a high power CW DFB-QCL.

    Science.gov (United States)

    Ma, Yufei; Lewicki, Rafał; Razeghi, Manijeh; Tittel, Frank K

    2013-01-14

    An ultra-sensitive and selective quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor platform was demonstrated for detection of carbon monoxide (CO) and nitrous oxide (N2O). This sensor used a state-of-the art 4.61 μm high power, continuous wave (CW), distributed feedback quantum cascade laser (DFB-QCL) operating at 10°C as the excitation source. For the R(6) CO absorption line, located at 2169.2 cm(-1), a minimum detection limit (MDL) of 1.5 parts per billion by volume (ppbv) at atmospheric pressure was achieved with a 1 sec acquisition time and the addition of 2.6% water vapor concentration in the analyzed gas mixture. For the N2O detection, a MDL of 23 ppbv was obtained at an optimum gas pressure of 100 Torr and with the same water vapor content of 2.6%. In both cases the presence of water vapor increases the detected CO and N2O QEPAS signal levels as a result of enhancing the vibrational-translational relaxation rate of both target gases. Allan deviation analyses were performed to investigate the long term performance of the CO and N2O QEPAS sensor systems. For the optimum data acquisition time of 500 sec a MDL of 340 pptv and 4 ppbv was obtained for CO and N2O detection, respectively. To demonstrate reliable and robust operation of the QEPAS sensor a continuous monitoring of atmospheric CO and N2O concentration levels for a period of 5 hours were performed.

  13. Nearly Blinking-Free, High-Purity Single-Photon Emission by Colloidal InP/ZnSe Quantum Dots.

    Science.gov (United States)

    Chandrasekaran, Vigneshwaran; Tessier, Mickaël D; Dupont, Dorian; Geiregat, Pieter; Hens, Zeger; Brainis, Edouard

    2017-10-11

    Colloidal core/shell InP/ZnSe quantum dots (QDs), recently produced using an improved synthesis method, have a great potential in life-science applications as well as in integrated quantum photonics and quantum information processing as single-photon emitters. Single-particle spectroscopy of 10 nm QDs with 3.2 nm cores reveals strong photon antibunching attributed to fast (70 ps) Auger recombination of multiple excitons. The QDs exhibit very good photostability under strong optical excitation. We demonstrate that the antibunching is preserved when the QDs are excited above the saturation intensity of the fundamental-exciton transition. This result paves the way toward their usage as high-purity on-demand single-photon emitters at room temperature. Unconventionally, despite the strong Auger blockade mechanism, InP/ZnSe QDs also display very little luminescence intermittency ("blinking"), with a simple on/off blinking pattern. The analysis of single-particle luminescence statistics places these InP/ZnSe QDs in the class of nearly blinking-free QDs, with emission stability comparable to state-of-the-art thick-shell and alloyed-interface CdSe/CdS, but with improved single-photon purity.

  14. Nearly Blinking-Free, High-Purity Single-Photon Emission by Colloidal InP/ZnSe Quantum Dots

    Science.gov (United States)

    Chandrasekaran, Vigneshwaran; Tessier, Mickaël D.; Dupont, Dorian; Geiregat, Pieter; Hens, Zeger; Brainis, Edouard

    2017-10-01

    Colloidal core/shell InP/ZnSe quantum dots (QDs), recently produced using an improved synthesis method, have a great potential in life-science applications as well as in integrated quantum photonics and quantum information processing as single-photon emitters. Single-particle spectroscopy of 10-nm QDs with 3.2-nm cores reveals strong photon antibunching attributed to fast (70-ps) Auger recombination of multiple excitons. The QDs exhibit very good photostability under strong optical excitation. We demonstrate that the antibunching is preserved when the QDs are excited above the saturation intensity of the fundamental-exciton transition. This result paves the way towards their usage as high-purity on-demand single-photon emitters at room temperature. Unconventionally, despite the strong Auger blockade mechanism, InP/ZnSe QDs also display very little luminescence intermittency ("blinking"), with a simple on/off blinking pattern. The analysis of single-particle luminescence statistics places these InP/ZnSe QDs in the class of nearly blinking-free QDs, with emission stability comparable to state-of-the-art thick-shell and alloyed-interface CdSe/CdS, but with improved single-photon purity.

  15. High Color-Purity Green, Orange, and Red Light-Emitting Didoes Based on Chemically Functionalized Graphene Quantum Dots

    Science.gov (United States)

    Kwon, Woosung; Kim, Young-Hoon; Kim, Ji-Hee; Lee, Taehyung; Do, Sungan; Park, Yoonsang; Jeong, Mun Seok; Lee, Tae-Woo; Rhee, Shi-Woo

    2016-04-01

    Chemically derived graphene quantum dots (GQDs) to date have showed very broad emission linewidth due to many kinds of chemical bondings with different energy levels, which significantly degrades the color purity and color tunability. Here, we show that use of aniline derivatives to chemically functionalize GQDs generates new extrinsic energy levels that lead to photoluminescence of very narrow linewidths. We use transient absorption and time-resolved photoluminescence spectroscopies to study the electronic structures and related electronic transitions of our GQDs, which reveals that their underlying carrier dynamics is strongly related to the chemical properties of aniline derivatives. Using these functionalized GQDs as lumophores, we fabricate light-emitting didoes (LEDs) that exhibit green, orange, and red electroluminescence that has high color purity. The maximum current efficiency of 3.47 cd A-1 and external quantum efficiency of 1.28% are recorded with our LEDs; these are the highest values ever reported for LEDs based on carbon-nanoparticle phosphors. This functionalization of GQDs with aniline derivatives represents a new method to fabricate LEDs that produce natural color.

  16. High Color-Purity Green, Orange, and Red Light-Emitting Didoes Based on Chemically Functionalized Graphene Quantum Dots

    Science.gov (United States)

    Kwon, Woosung; Kim, Young-Hoon; Kim, Ji-Hee; Lee, Taehyung; Do, Sungan; Park, Yoonsang; Jeong, Mun Seok; Lee, Tae-Woo; Rhee, Shi-Woo

    2016-01-01

    Chemically derived graphene quantum dots (GQDs) to date have showed very broad emission linewidth due to many kinds of chemical bondings with different energy levels, which significantly degrades the color purity and color tunability. Here, we show that use of aniline derivatives to chemically functionalize GQDs generates new extrinsic energy levels that lead to photoluminescence of very narrow linewidths. We use transient absorption and time-resolved photoluminescence spectroscopies to study the electronic structures and related electronic transitions of our GQDs, which reveals that their underlying carrier dynamics is strongly related to the chemical properties of aniline derivatives. Using these functionalized GQDs as lumophores, we fabricate light-emitting didoes (LEDs) that exhibit green, orange, and red electroluminescence that has high color purity. The maximum current efficiency of 3.47 cd A−1 and external quantum efficiency of 1.28% are recorded with our LEDs; these are the highest values ever reported for LEDs based on carbon-nanoparticle phosphors. This functionalization of GQDs with aniline derivatives represents a new method to fabricate LEDs that produce natural color. PMID:27048887

  17. Thermal behavior of Ni (99.967% and 99.5% purity) deformed to an ultra-high strain by high pressure torsion

    DEFF Research Database (Denmark)

    Zhang, H.W.; Huang, Xiaoxu; Pippan, R.

    2010-01-01

    Polycrystalline Ni of two purities (99.967% (4N) and 99.5% (2N)) was deformed to an ultra-high strain of εvM = 100 (εvM, von Mises strain) by high pressure torsion at room temperature. The 4N and 2N samples at this strain are nanostructured with an average boundary spacing of 100 nm, a high density...

  18. Microwave-Hydrothermal Synthesis and Characterization of High-Purity Nb Doped BaTiO3 Nanocrystals

    OpenAIRE

    A. Khanfekr; Tamizifar, M.; R. Naghizadeh

    2014-01-01

    The synthesis of Nb doped BaTiO3 has been investigated under Microwave-Hydrothermal (MH) conditions in the temperature of 150°C for only 2 h using C16H36O4Ti, BaH2O2.8H2O and NbCl5 as Ba, Ti and  Nb sources, respectively.  Typical experiments performed on MH processing have not yet reported for Nb doped BaTiO3.  In the MH process, the formation of high purity nano tetragonal Nb-BaTiO3 was strongly enhanced. New hydrothermal method was used instead of the previous solid state reaction for the ...

  19. Development of a 200 W CW high efficiency traveling wave tube at 12 GHz. [for use in communication technology satellites

    Science.gov (United States)

    Christensen, J. A.; Tammaru, I.

    1974-01-01

    The design, development, and test results are reported for an experimental PPM focused, traveling-wave tube that produces 235 watts of CW RF power over 85 MHz centered at 12.080 GHz. The tube uses a coupled cavity RF circuit with a velocity taper for greater than 30 percent basic efficiency. Overall efficiency of 51 percent is achieved by means of a nine stage depressed collector designed at NASA Lewis Research Center. This collector is cooled by direct radiation to deep space.

  20. High-field CW electron paramagnetic resonance spectroscopy with Gd(III) tags for structure-dynamics studies of proteorhodopsin

    Science.gov (United States)

    Clayton, Jessica A.; Han, Chung-Ta; Wilson, C. Blake; Qi, Mian; Godt, Adelheid; Goldfarb, Daniella; Sherwin, Mark S.; Han, Songi

    Proteorhodopsin (PR) is a seven-helical transmembrane protein that functions as a light-activated proton pump. Much of the structure of PR has been mapped by solution-state NMR and X-ray crystallography, however it remains difficult to study protein associations and conformational changes. Here we report development of 240 GHz CW electron paramagnetic resonance (EPR) as a tool to determine inter- and intra-protein distances in the range of 1-4 nm under biologically relevant conditions, using S = 7/2 Gd(III)-based complexes as an EPR-active paramagnetic tag. The dipolar coupling between Gd(III) pairs is determined via the width of the central transition in the CW EPR spectrum, allowing for the inference of an interspin distance. Proof-of-principle experiments are demonstrated on Gd-ruler molecules, from cryogenic temperatures up to room temperature. First results applying this method to inter-protein measurement of Gd(III) tagged PR oligomers reveals distances consistent with the penta- or hexameric organization determined by crystal structure. Finally, we present progress towards development of measurement methods that will enable observation of light-induced conformational changes in the EF-loop region of PR at temperatures above the protein dynamical transition. This work is supported by NSF MCB-1617025 and NSF MCB-1244651.

  1. Quantification of the microstructures of high purity nickel subjected to dynamic plastic deformation

    DEFF Research Database (Denmark)

    Luo, Z.P.; Zhang, H.W.; Hansen, Niels

    2012-01-01

    A quantitative microstructural analysis is presented for pure polycrystalline nickel processed by means of dynamic plastic deformation at high strain rates (102–103 s−1) to strains from 0.3 to 2.9. This analysis covers a number of structural parameters, such as the spacing between...

  2. The flow stress of high-purity refractory body-centred cubic metals and its modification by atomic defects

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, A. [Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany). Inst. fuer Physik

    1995-11-01

    The strong temperature and strain-rate dependence of the flow stress of high-purity refractory body-centred cubic metals has been shown to be an intrinsic property and is ascribed to a high Peierls barrier of a{sub o} left angle 111 right angle /2 screw dislocations. These barriers are overcome by the formation of kink pairs on the screw dislocations. The paper reports on recent, complete flow-stress data on ultra-high purity Mo crystals obtained by two different experimental techniques. The results are in accord with earlier work of Brunner and Diehl on {alpha}-Fe, who showed that below the so-called knee temperature, T{sub K}, three regimes in the temperature variation of the flow-stress should be distinguished. Two of them are fully accounted for by the same glide mechanism, namely elementary glide steps on {l_brace}211{r_brace} planes. The upper bend separating these two regimes in an inherent feature of the theory of kink-pair formation and does not indicate a change in the glide mechanism. There is strong evidence that the lower bend, separating the range of {l_brace}211{r_brace} elementary glide steps from the low-temperature flow-stress regime, is due to a change in the glide mechanism. It is argued that at the lower bend the screw-dislocation cores undergo a ``first-order phase transition`` from a low-temperature configuration that allows glide of a given screw dislocation on any of its three {l_brace}110{r_brace} glide planes to a high-temperature configuration that can glide only on one definite {l_brace}211{r_brace} plane. Between T{sub K} and the lower-bend temperature, T, bcc metals may show the unique phenomena of alloy and irradiation softening. With regard to the latter phenomenon, Brunner and Diehl distinguish between ``primary`` and ``secondary`` softening. It is shown that alloy softening and the ``secondary irradiation softening`` of bcc metals may be explained by an ``overheating`` of the phase transition in the dislocation core. (orig./WL).

  3. High Color-Purity Green, Orange, and Red Light-Emitting Didoes Based on Chemically Functionalized Graphene Quantum Dots

    National Research Council Canada - National Science Library

    Kwon, Woosung; Kim, Young-Hoon; Kim, Ji-Hee; Lee, Taehyung; Do, Sungan; Park, Yoonsang; Jeong, Mun Seok; Lee, Tae-Woo; Rhee, Shi-Woo

    2016-01-01

    Chemically derived graphene quantum dots (GQDs) to date have showed very broad emission linewidth due to many kinds of chemical bondings with different energy levels, which significantly degrades the color purity and color tunability...

  4. High-Purity Hybrid Organolead Halide Perovskite Nanoparticles Obtained by Pulsed-Laser Irradiation in Liquid

    KAUST Repository

    Amendola, Vincenzo

    2016-11-17

    Nanoparticles of hybrid organic-inorganic perovskites have attracted a great deal of attention due to their variety of optoelectronic properties, their low cost, and their easier integration into devices with complex geometry, compared with microcrystalline, thin-film, or bulk metal halides. Here we present a novel one-step synthesis of organolead bromide perovskite nanocrystals based on pulsed-laser irradiation in a liquid environment (PLIL). Starting from a bulk CHNHPbBr crystal, our PLIL procedure does not involve the use of high-boiling-point polar solvents or templating agents, and runs at room temperature. The resulting nanoparticles are characterized by high crystallinity and are completely free of any microscopic product or organic coating layer. We also demonstrate the straightforward inclusion of laser-generated perovskite nanocrystals in a polymeric matrix to form a nanocomposite with single- and two-photon luminescence properties.

  5. Technology for processing ammonium rhodanide of coking plants into high-purity ammonium thiocyanate and thiourea

    Energy Technology Data Exchange (ETDEWEB)

    Urakaev, F.K. [Institute of Geology & Mineral SB RAS, Novosibirsk (Russian Federation)

    2009-04-15

    The regularities of the reversible reaction of isomerization of ammonium thiocyanate (NH{sub 4}NCS) into thiourea (NH{sub 2}){sub 2}CS, and the reverse reaction, were analyzed. An ecologically clean and highly efficient method for the extraction, purification, separation, and production of isomers from the coal byproduct ammonium thiocyanate was developed based on the measured volatilities of NH{sub 4}NCS and (NH{sub 2}){sub 2}CS.

  6. Effects of Trace Metals and Organic Additives on Porosity and Dielectric Constant of High Purity Mesoporous Silica Films

    Energy Technology Data Exchange (ETDEWEB)

    Birnbaum, Jerome C.; Fryxell, Glen E.; Li, Xiaohong S.; Coyle, Christopher A.; Dunham, Glen C.; Baskaran, Suresh

    2003-07-10

    Porous ceramic and porous hybrid ceramic films are potentially useful as low dielectric constant interlayers in semiconductor interconnects (1-6). The hybrid ceramic films are generally defined as films that contain both organic and ceramic molecular components in the structure, as for example, organosilicate films. A key challenge with advanced dielectric films in interconnects is the need for extremely low dielectric constants in very high purity materials (<50 parts per billion metal impurities). This communication describes observations related to film properties as a function of metal content in molecularly templated porous films, and a specific family of additives that may be used with highly pure alkali-metal-free ceramic and hybrid precursors for such dielectric films that will enable better control of the film porosity and quality, and lower dielectric constants, while maintaining the required mechanical integrity. The efficacy of such additives is illustrated using surfactant-templated mesoporous silicate films as a model example. This formulation could be broadly applicable to any cross-linked ceramic or hybrid ceramic films, including silicate and organosilicate films, and especially highly porous forms of the films for low dielectric constant applications.

  7. Preparation and Stoichiometry Effects on Microstructure and Properties of High Purity BaTiO3.

    Science.gov (United States)

    1986-03-27

    established calcined powders. Hydrothermal synthesis of polycrystalline BaTIO 3 involves dissolution of barium hydroxide and titanium dioxide in a...thermal decomposition of oxalates and by hydrothermal synthesis . As-received lots of mixed oxide and oxalate-derived powders had Ba:TI ratios of 0.997 and...BaTiO 3," Bull. Am. Ceram. Soc., 60 [5] 566-70 (1981). 10. L. I Shvets, N. A. Ovramenko and F. 0. Qvramenko, " Hydrothermal Synthesis of Highly-Dispersed

  8. thesis of high-purity carbon nanotubes over alumina and silica supported bimetallic catalysts

    Directory of Open Access Journals (Sweden)

    Sanja Ratković

    2009-10-01

    Full Text Available Carbon nanotubes (CNTs were synthesized by a catalytic chemical vapor deposition method (CCVD of ethylene over alumina and silica supported bimetallic catalysts based on Fe, Co and Ni. The catalysts were prepared by a precipitation method, calcined at 600 °C and in situ reduced in hydrogen flow at 700 °C. The CNTs growth was carried out by a flow the mixture of C2H4 and nitrogen over the catalyst powder in a horizontal oven. The structure and morphology of as-synthesized CNTs were characterized using SEM. The as-synthesized nanotubes were purified by acid and basic treatments in order to remove impurities such as amorphous carbon, graphite nanoparticles and metal catalysts. XRD and DTA/TG analyses showed that the amounts of by-products in the purified CNTs samples were reduced significantly. According to the observed results, ethylene is an active carbon source for growing high-density CNTs with high yield but more on alumina-supported catalysts than on their silica- supported counterparts. The last might be explained by SMSI formed in the case of alumina-supported catalysts, resulting in higher active phase dispersion.

  9. A simplified method for obtaining high-purity perchlorate from groundwater for isotope analyses.

    Energy Technology Data Exchange (ETDEWEB)

    vonKiparski, G; Hillegonds, D

    2011-04-04

    Investigations into the occurrence and origin of perchlorate (ClO{sub 4}{sup -}) found in groundwater from across North America have been sparse until recent years, and there is mounting evidence that natural formation mechanisms are important. New opportunities for identifying groundwater perchlorate and its origin have arisen with the utilization of improved detection methods and sampling techniques. Additionally, application of the forensic potential of isotopic measurements has begun to elucidate sources, potential formation mechanisms and natural attenuation processes. Procedures developed appear to be amenable to enable high precision stable isotopic analyses, as well as lower precision AMS analyses of {sup 36}Cl. Immediate work is in analyzing perchlorate isotope standards and developing full analytical accuracy and uncertainty expectations. Field samples have also been collected, and will be analyzed when final qa/qc samples are deemed acceptable.

  10. A method for high purity sorting of rare cell subsets applied to TDC.

    Science.gov (United States)

    Kuka, Mirela; Ashwell, Jonathan D

    2013-12-31

    T(DC) are a recently described subset of polyclonal αβ T-cells with dendritic cell properties. Because of their low number in peripheral immune compartments, isolation and characterization of T(DC) with existing purification methods are technically challenging. Here we describe a customized gating strategy and a flow cytometry-based cell sorting protocol for isolation of T(DC). The protocol was developed because, despite very conservative gating for dead-cell and doublet exclusion, cells obtained with normal sorting procedures were enriched for T(DC) but not pure. Re-sorting the output of the first round of sorting results in highly pure T(DC). Cells obtained with this method are viable and can be used for in vitro characterization. Moreover, this double-round sorting strategy can be universally applied to the isolation of other rare cell subsets. © 2013.

  11. Potential of hot water extraction of birch wood to produce high-purity dissolving pulp after alkaline pulping.

    Science.gov (United States)

    Borrega, Marc; Tolonen, Lasse K; Bardot, Fanny; Testova, Lidia; Sixta, Herbert

    2013-05-01

    The potential of hot water extraction of birch wood to produce highly purified dissolving pulp in a subsequent soda-anthraquinone pulping process was evaluated. After intermediate extraction intensities, pulps with low xylan content (3-5%) and high cellulose yield were successfully produced. Increasing extraction intensity further decreased the xylan content in pulp. However, below a xylan content of 3%, the cellulose yield dramatically decreased. This is believed to be due to cleavage of glycosidic bonds in cellulose during severe hot water extractions, followed by peeling reactions during alkaline pulping. Addition of sodium borohydride as well as increased anthraquinone concentration in the pulping liquor increased the cellulose yield, but had no clear effects on pulp purity and viscosity. The low intrinsic viscosity of pulps produced after severe extraction intensities and soda-anthraquinone pulping corresponded to the viscosity at the leveling-off degree of polymerization, suggesting that nearly all amorphous cellulose had been degraded. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Cobalt(I) Olefin Complexes: Precursors for Metal-Organic Chemical Vapor Deposition of High Purity Cobalt Metal Thin Films.

    Science.gov (United States)

    Hamilton, Jeff A; Pugh, Thomas; Johnson, Andrew L; Kingsley, Andrew J; Richards, Stephen P

    2016-07-18

    We report the synthesis and characterization of a family of organometallic cobalt(I) metal precursors based around cyclopentadienyl and diene ligands. The molecular structures of the complexes cyclopentadienyl-cobalt(I) diolefin complexes are described, as determined by single-crystal X-ray diffraction analysis. Thermogravimetric analysis and thermal stability studies of the complexes highlighted the isoprene, dimethyl butadiene, and cyclohexadiene derivatives [(C5H5)Co(η(4)-CH2CHC(Me)CH2)] (1), [(C5H5)Co(η(4)-CH2C(Me)C(Me)CH2)] (2), and [(C5H5)Co(η(4)-C6H8)] (4) as possible cobalt metal organic chemical vapor deposition (MOCVD) precursors. Atmospheric pressure MOCVD was employed using precursor 1, to synthesize thin films of metallic cobalt on silicon substrates under an atmosphere (760 torr) of hydrogen (H2). Analysis of the thin films deposited at substrate temperatures of 325, 350, 375, and 400 °C, respectively, by scanning electron microscopy and atomic force microscopy reveal temperature-dependent growth features. Films grown at these temperatures are continuous, pinhole-free, and can be seen to be composed of hexagonal particles clearly visible in the electron micrograph. Powder X-ray diffraction and X-ray photoelectron spectroscopy all show the films to be highly crystalline, high-purity metallic cobalt. Raman spectroscopy was unable to detect the presence of cobalt silicides at the substrate/thin film interface.

  13. Microwave-Hydrothermal Synthesis and Characterization of High-Purity Nb Doped BaTiO3 Nanocrystals

    Directory of Open Access Journals (Sweden)

    A. Khanfekr

    2014-01-01

    Full Text Available The synthesis of Nb doped BaTiO3 has been investigated under Microwave-Hydrothermal (MH conditions in the temperature of 150°C for only 2 h using C16H36O4Ti, BaH2O2.8H2O and NbCl5 as Ba, Ti and  Nb sources, respectively.  Typical experiments performed on MH processing have not yet reported for Nb doped BaTiO3.  In the MH process, the formation of high purity nano tetragonal Nb-BaTiO3 was strongly enhanced. New hydrothermal method was used instead of the previous solid state reaction for the BaTiO3±Nb2O3 system. The new method uses high pressure to create nano dimension particles in a lower time and temperature. In case of the phase evolution studies, the XRD pattern measurements and Raman spectroscopy were performed. TEM and FE-SEM images were taken for the detailed analysis of the particle size, surface and morphology.  Synthesis of Nb doped BaTiO3 with the Microwave-hydrothermal provides an advantage of fast crystallization and reduced crystal size when compared to existing methods.

  14. Polytype Stabilization of High-purity Semi-insulating 4H-SiC Crystal via the PVT Method

    Directory of Open Access Journals (Sweden)

    Kai-li MAO

    2016-05-01

    Full Text Available Because the conditions under which semi-insulating 4H-SiC crystals can grow are so specific, other polytypes such as 15R and 6H can easily emerge during the growth process. In this work, a polytype stabilization technology was developed by altering the following parameters: growth temperature, temperature field distribution, and C/Si ratio. In the growth process of high-purity semi-insulating 4H-SiC crystals, the generation of undesirable polytypes was prevented, and a crystal 100 % 4H-SiC polytype was obtained. A high C/Si ratio in powder source was shown to be advantageous for the stabilization of the 4H polytype. Several methods were applied to evaluate the quality of crystals precisely; these methods include Raman mapping, X-ray diffraction, and resistivity mapping. Results showed that the 3inch-wafer was entirely made of 4H polytype, the mean value of FWHM was approximately 40 arcsec, and the distribution of the resistivity value was between 106 Ω×cm and 107 Ω×cm.DOI: http://dx.doi.org/10.5755/j01.ms.22.2.12914

  15. Synthesis and morphological examination of high-purity Ca(OH)2 nanoparticles suitable to consolidate porous surfaces

    Science.gov (United States)

    Madrid, Juan Antonio; Lanzón, Marcos

    2017-12-01

    Adequate synthetic methods to obtain pure Ca(OH)2 nanoparticles are scarcely documented in the literature. This paper presents a complete methodology to obtain highly-pure Ca(OH)2 nanoparticles that are appropriate for strengthening heritage materials. The precipitation synthesis was operated in controlled atmosphere to avoid carbonation by atmospheric CO2. A complete purification method was developed to eliminate the sodium chloride generated in the reaction. Several analytical techniques, such as electrical conductivity, pH, ion chromatography, X-ray diffraction (XRD) and thermogravimetric analysis coupled to mass spectrometry (TGA-MS) were used to analyse both the aqueous medium and solid phase. The amount of material obtained in the synthesis (yield) was quantified throughout the purification procedure. The influence of temperature on the nanoparticles' size and stability was studied by transmission electron microscopy (HRTEM) and sedimentation tests (light scattering). It was found that the synthesis yielded high-purity nanoparticles, whose morphological features were greatly affected by the reaction temperature.

  16. Experimental Demonstration of Advanced Palladium Membrane Separators for Central High Purity Hydrogen Production

    Energy Technology Data Exchange (ETDEWEB)

    Sean Emerson; Neal Magdefrau; Susanne Opalka; Ying She; Catherine Thibaud-Erkey; Thoman Vanderspurt; Rhonda Willigan

    2010-06-30

    The overall objectives for this project were to: (1) confirm the high stability and resistance of a PdCu trimetallic alloy to carbon and carbide formation and, in addition, resistance to sulfur, halides, and ammonia; (2) develop a sulfur, halide, and ammonia resistant alloy membrane with a projected hydrogen permeance of 25 m{sup 3}m{sup -2}atm{sup -0.5}h{sup -1} at 400 C and capable of operating at pressures of 12.1 MPa ({approx}120 atm, 1750 psia); and (3) construct and experimentally validate the performance of 0.1 kg/day H{sup 2} PdCu trimetallic alloy membrane separators at feed pressures of 2 MPa (290 psia) in the presence of H{sub 2}S, NH{sub 3}, and HCl. This project successfully increased the technology readiness level of palladium-based metallic membranes for hydrogen separation from coal-biomass gasifier exhaust or similar hydrogen-containing gas streams. The reversible tolerance of palladium-copper (PdCu) alloys was demonstrated for H{sub 2}S concentrations varying from 20 ppmv up to 487 ppmv and NH{sub 3} concentrations up to 9 ppmv. In addition, atomistic modeling validated the resistance of PdCu alloys to carbon formation, irreversible sulfur corrosion, and chlorine attack. The experimental program highlighted two key issues which must be addressed as part of future experimental programs: (1) tube defects and (2) non-membrane materials of construction. Four out of five FCC PdCu separators developed leaks during the course of the experimental program because {approx}10% of the alloy tubes contained a single defect that resulted in a thin, weak point in the tube walls. These defects limited operation of the existing tubes to less than 220 psig. For commercial applications of a PdCu alloy hydrogen separator under high sulfur concentrations, it was determined that stainless steel 316 is not suitable for housing or supporting the device. Testing with sulfur concentrations of 487 {+-} 4 ppmv resulted in severe corrosion of the stainless steel components of

  17. A Process Concept for High-Purity Production of Amines by Transaminase-Catalyzed Asymmetric Synthesis: Combining Enzyme Cascade and Membrane-Assisted ISPR

    DEFF Research Database (Denmark)

    Börner, Tim; Rehn, Gustav; Grey, Carl

    2015-01-01

    in situ product removal (ISPR) approach using liquid-membrane extraction together with an enzyme cascade. This ISPR strategy facilitates very high (>98%) product purity with an integrated enrichment step and eliminates product as well as coproduct inhibition. In the presented proof-of-concept alanine...

  18. Production of High-Purity Anhydrous Nickel(II) Perrhenate for Tungsten-Based Sintered Heavy Alloys.

    Science.gov (United States)

    Leszczyńska-Sejda, Katarzyna; Benke, Grzegorz; Kopyto, Dorota; Majewski, Tomasz; Drzazga, Michał

    2017-04-24

    This paper presents a method for the production of high-purity anhydrous nickel(II) perrhenate. The method comprises sorption of nickel(II) ions from aqueous nickel(II) nitrate solutions, using strongly acidic C160 cation exchange resin, and subsequent elution of sorbed nickel(II) ions using concentrated perrhenic acid solutions. After the neutralization of the resulting rhenium-nickel solutions, hydrated nickel(II) perrhenate is then separated and then dried at 160 °C to obtain the anhydrous form. The resulting compound is reduced in an atmosphere of dissociated ammonia in order to produce a Re-Ni alloy powder. This study provides information on the selected properties of the resulting Re-Ni powder. This powder was used as a starting material for the production of 77W-20Re-3Ni heavy alloys. Microstructure examination results and selected properties of the produced sintered heavy alloys were compared to sintered alloys produced using elemental W, Re, and Ni powders. This study showed that the application of anhydrous nickel(II) perrhenate in the production of 77W-20Re-3Ni results in better properties of the sintered alloys compared to those made from elemental powders.

  19. Control of the Gas Flow in an Industrial Directional Solidification Furnace for Production of High Purity Multicrystalline Silicon Ingots

    Directory of Open Access Journals (Sweden)

    Lijun Liu

    2015-01-01

    Full Text Available A crucible cover was designed as gas guidance to control the gas flow in an industrial directional solidification furnace for producing high purity multicrystalline silicon. Three cover designs were compared to investigate their effect on impurity transport in the furnace and contamination of the silicon melt. Global simulations of coupled oxygen (O and carbon (C transport were carried out to predict the SiO and CO gases in the furnace as well as the O and C distributions in the silicon melt. Cases with and without chemical reaction on the cover surfaces were investigated. It was found that the cover design has little effect on the O concentration in the silicon melt; however, it significantly influences CO gas transport in the furnace chamber and C contamination in the melt. For covers made of metal or with a coating on their surfaces, an optimal cover design can produce a silicon melt free of C contamination. Even for a graphite cover without a coating, the carbon concentration in the silicon melt can be reduced by one order of magnitude. The simulation results demonstrate a method to control the contamination of C impurities in an industrial directional solidification furnace by crucible cover design.

  20. Production of High-Purity Anhydrous Nickel(II Perrhenate for Tungsten-Based Sintered Heavy Alloys

    Directory of Open Access Journals (Sweden)

    Katarzyna Leszczyńska-Sejda

    2017-04-01

    Full Text Available This paper presents a method for the production of high-purity anhydrous nickel(II perrhenate. The method comprises sorption of nickel(II ions from aqueous nickel(II nitrate solutions, using strongly acidic C160 cation exchange resin, and subsequent elution of sorbed nickel(II ions using concentrated perrhenic acid solutions. After the neutralization of the resulting rhenium-nickel solutions, hydrated nickel(II perrhenate is then separated and then dried at 160 °C to obtain the anhydrous form. The resulting compound is reduced in an atmosphere of dissociated ammonia in order to produce a Re-Ni alloy powder. This study provides information on the selected properties of the resulting Re-Ni powder. This powder was used as a starting material for the production of 77W-20Re-3Ni heavy alloys. Microstructure examination results and selected properties of the produced sintered heavy alloys were compared to sintered alloys produced using elemental W, Re, and Ni powders. This study showed that the application of anhydrous nickel(II perrhenate in the production of 77W-20Re-3Ni results in better properties of the sintered alloys compared to those made from elemental powders.

  1. Production of high-purity nickel base alloys by electroslag remelting; Hochreine Nickelbasislegierungen durch Elektro-Schlacke-Umschmelzverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Schmilinsky, E. [Krupp VDM GmbH, Unna (Germany). Umschmelzbetrieb; Scholz, H. [ALD Vacuum Technologies GmbH, Erlensee (Germany)

    2000-12-01

    Electroslag melting is a process for production of high-density, low-fault blocks of high-purity special alloys ready for hot forming. A new melting unit is currently being constructed at the Unna plant of Krupp VDM GmbH. The whole melting process takes place in an adjustable inert gas atmosphere and is fully automatic. Refined alloys are used in applications where high corrosion resistance or high temperature resistance are required, e.g. in gas turbines, motor valves, offshore plants and the electronic industry. [German] Das Elektro-Schlacke-Umschmelzen (ESU) ermoeglicht die Erzeugung dichter, seigerungsarmer Bloecke von hochreinen Speziallegierungen, die auf Grund ihrer glatten und fehlerfreien Oberflaeche direkt durch Warmumformung weiterverarbeitet werden koennen. Am Standort Unna der Krupp VDM GmbH wird derzeit eine neue Umschmelzanlage in Betrieb genommen. Eine Besonderheit dieser Anlage ist ein gasdichter und evakuierbarer Ofenkessel fuer Rundformate, bei dem der gesamte Umschmelzprozess, der bei konventionellen ESU-Anlagen unter Luftatmosphaere stattfindet, unter einer gezielt einstellbaren Schutzgasatmosphaere ablaeuft. Eine ESU-Charge, die je nach Blockgewicht und -format bis zu 24 Stunden dauern kann, gliedert sich in Start-, Hauptschmelz- und Schopfheizphase auf. Die einzelnen Phasen laufen bei der VDM-Anlage nach Eingabe des Startdialogs, von einem Anlagen-Rechner gesteuert, vollautomatisch ab. Das Ergebnis des ESU-Prozesses ist ein Block mit isotropen Eigenschaften, hoher Dichte und Homogenitaet, ohne Seigerungen und Lunker. Umgeschmolzene Legierungen werden ueberall dort eingesetzt, wo ein Hoechstmass an Bestaendigkeit gegen korrosive Einwirkung oder hohe Temperaturen gefordert wird, wie z.B. bei Gasturbinen, Motorventilen, im Offshore-Bereich und in der Elektronikindustrie. (orig.)

  2. Measurements of carbon monoxide mixing ratios in Houston using a compact high-power CW DFB-QCL-based QEPAS sensor

    Science.gov (United States)

    Stefański, Przemysław; Lewicki, Rafał; Sanchez, Nancy P.; Tarka, Jan; Griffin, Robert J.; Razeghi, Manijeh; Tittel, Frank K.

    2014-06-01

    Measurements of carbon monoxide (CO) mixing ratios in Houston, Texas, during the period from May 16, 2013 to May 28, 2013 were performed using a sensitive, selective, compact, and portable quartz-enhanced photoacoustic spectroscopy (QEPAS)-based CO sensor employing a high-power continuous wave (CW) distributed feedback quantum cascade laser (DFB-QCL). The minimum detectable CO concentration was 3 ppbv for the strong, interference-free R(6) absorption line at 2,169.2 cm-1 and a 5 s data acquisition time. The average CO concentration during the measurement period was 299.1 ± 81.4 ppb with observed minimum and maximum values of 210.5 and 4,307.9 ppb, respectively. A commercially available electrochemical sensor was employed in-line for simultaneous measurements to confirm the response of the CW DFB-QCL-based QEPAS sensor to variations of the CO mixing ratios. Moderate agreement (R 2 = 0.7) was found between both sets of CO measurements.

  3. The Production of High Purity Phycocyanin by Spirulina platensis Using Light-Emitting Diodes Based Two-Stage Cultivation.

    Science.gov (United States)

    Lee, Sang-Hyo; Lee, Ju Eun; Kim, Yoori; Lee, Seung-Yop

    2016-01-01

    Phycocyanin is a photosynthetic pigment found in photosynthetic cyanobacteria, cryptophytes, and red algae. In general, production of phycocyanin depends mainly on the light conditions during the cultivation period, and purification of phycocyanin requires expensive and complex procedures. In this study, we propose a new two-stage cultivation method to maximize the quantitative content and purity of phycocyanin obtained from Spirulina platensis using red and blue light-emitting diodes (LEDs) under different light intensities. In the first stage, Spirulina was cultured under a combination of red and blue LEDs to obtain the fast growth rate until reaching an absorbance of 1.4-1.6 at 680 nm. Next, blue LEDs were used to enhance the concentration and purity of the phycocyanin in Spirulina. Two weeks of the two-stage cultivation of Spirulina yielded 1.28 mg mL(-1) phycocyanin with the purity of 2.7 (OD620/OD280).

  4. Simultaneous determination of purity and potency of the components of gentamycin using high-performance liquid chromatography.

    Science.gov (United States)

    Yang, Li-Hong; Chang, Yan; Yao, Shang-Chen; Hu, Chang-Qin

    2012-12-01

    The quality of some earlier developed antibiotics is usually ensured by the combination of HPLC purity and microbiological potency measurement in the pharmacopoeias of various countries because the relationship between their purity and potency is not clearly quantified. Due to potency is assessed using certain units of measurement, it can not be directly traced to the international system of units (SI unit). This has become a hotspot in the study of the quantitative relationship between purity and potency of antibiotics. It would be quite an achievement to simultaneously determine both purity and potency using HPLC methods during quality control. This study evaluated a multicomponent antibiotic product, gentamycin, as a test sample. First, pure samples of the C components of gentamycin: C1a, C2, C2a and C1 were prepared, separately. Second, quantitative relationship (theoretical potency) between the purity and potency of each C component of gentamycin were determined using 1H NMR, HPLC-ELSD and microbiological assay method. One milligram of gentamycin C1a, C2, C2a and C1 was equal to 1 286.98, 1 095.74, 1 079.52 and 739.61 gentamycin units, respectively. Finally, a method for the determination of gentamycin potency was established based on the proportion and content of C components of gentamycin. The unification of purity and potency for gentamycin was achieved using only HPLC-ELSD. It is also demonstrated that C components of gentamycin and micronomicin produce the same responses under ELSD, which means that it is not necessary to prepare separate reference standards for each C component of gentamycin and that quantitative testing can be performed accurately using only one micronomicin reference standard. This study simplified the previous method for the determination of the content of C components of gentamycin using HPLC-ELSD. The developed method is suitable for regular use as a part of quality control and can simplify the rigmarole quality control procedures

  5. Synthesis of high-purity Na-A and Na-X zeolite from coal fly ash.

    Science.gov (United States)

    Panitchakarn, Panu; Laosiripojana, Navadol; Viriya-Umpikul, Nawin; Pavasant, Prasert

    2014-05-01

    Coal fly ash (CFA) was used as a raw material for the synthesis of zeolite molecular sieve. The synthesis began with the pretreatment of CFA to remove impurities (e.g., Fe2O3, CaO, etc.) under various acid types (HCl, H2SO4, and HNO3) and acid/CFA ratios (5-25 mL(acid)/g(CFA)). High product purity (up to 97%) was achieved with HCl (20%wt), and acid/CFA ratio of 20 mL(HCl)/g(CFA). The treated CFA was then converted to zeolite by the fusion reaction under various Si/Al molar ratios (0.54-1.84). Zeolite type A was synthesized when the Si/Al molar ratios were lower than 1, whereas sodium aluminum silicate hydrate was formed when the Si/Al molar ratio were higher than 1. The highest water adsorption performance of the zeolite product, i.e., the outlet ethanol concentration of 99.9%wt and the specific adsorption capacity of 2.31 x 10(-2) g(water)/g(zeolite), was observed with the Si/Al molar ratio of 0.82. The zeolite was tested for its water adsorption capacity repeatedly 10 times without deactivation. This work evaluated the technical feasibility in the conversion of CFA to zeolite, which would help reduce the quantity of waste needed to be landfilled. This adds value to the unwanted material by converting it into something that can be further used. The synthesized products were shown to be quite stable as water adsorbent for the dehydration of ethanol solution.

  6. Unique low-molecular-weight lignin with high purity extracted from wood by deep eutectic solvents (DES): a source of lignin for valorization

    Energy Technology Data Exchange (ETDEWEB)

    Alvarez-Vasco, Carlos; Ma, Ruoshui; Quintero, Melissa; Guo, Mond; Geleynse, Scott; Ramasamy, Karthikeyan K.; Wolcott, Michael; Zhang, Xiao

    2016-01-01

    This paper reports a new method of applying Deep Eutectic Solvents (DES) for extracting lignin from woody biomass with high yield and high purity. DES mixtures prepared from Choline Chloride (ChCl) and four hydrogen-bond donors–acetic acid, lactic acid, levulinic acid and glycerol–were evaluated for treatment of hardwood (poplar) and softwood (D. fir). It was found that these DES treatments can selectively extract a significant amount of lignin from wood with high yields: 78% from poplar and 58% from D. fir. The extracted lignin has high purity (95%) with unique structural properties. We discover that DES can selectively cleave ether linkages in wood lignin and facilitate lignin removal from wood. The mechanism of DES cleavage of ether bonds between phenylpropane units was investigated. The results from this study demonstrate that DES is a promising solvent for wood delignification and the production of a new source of lignin with promising potential applications.

  7. Janus Graphene Oxide Sponges for High-Purity Fast Separation of Both Water-in-Oil and Oil-in-Water Emulsions.

    Science.gov (United States)

    Yun, Jongju; Khan, Fakhre Alam; Baik, Seunghyun

    2017-05-17

    Membrane separation of oil and water with high purity and high permeability is of great interest in environmental and industrial processes. However, membranes with fixed wettability can separate only one type of surfactant-stabilized emulsion (water-in-oil or oil-in-water). Here, we report on Janus graphene oxide (J-GO) sponges for high purity and high permeability separation of both water-in-oil and oil-in-water emulsions. Millimeter-scale reduced GO sponges with a controlled pore size (11.2 or 94.1 μm) are synthesized by freeze drying, and the wettability is further controlled by fluorine (hydrophobic/oleophilic in air) or oxygen (hydrophilic/oleophilic in air) functionalization. J-GO sponges are prepared by the fluorine functionalization on one side and oxygen functionalization on the other side. Interestingly, the oil wettability of oxygen-functionalized surface turns into an oleophobic surface when immersed in water, which is explained by Young's theory. This effect is further used in the separation of both water-in-oil and oil-in-water emulsions by changing the flow direction. The purity of the separated oil and water is very high (≥99.2%), and the permeability is more than an order of magnitude greater than those of the other Janus membranes reported. J-GO sponges can be reused with an excellent repeatability, demonstrating feasibility in practical applications.

  8. High Color-Purity Green, Orange, and Red Light-Emitting Didoes Based on Chemically Functionalized Graphene Quantum Dots

    OpenAIRE

    Woosung Kwon; Young-Hoon Kim; Ji-Hee Kim; Taehyung Lee; Sungan Do; Yoonsang Park; Mun Seok Jeong; Tae-Woo Lee; Shi-Woo Rhee

    2016-01-01

    Chemically derived graphene quantum dots (GQDs) to date have showed very broad emission linewidth due to many kinds of chemical bondings with different energy levels, which significantly degrades the color purity and color tunability. Here, we show that use of aniline derivatives to chemically functionalize GQDs generates new extrinsic energy levels that lead to photoluminescence of very narrow linewidths. We use transient absorption and time-resolved photoluminescence spectroscopies to study...

  9. Synthesis of high-purity Li{sub 8}ZrO{sub 6} powder by solid state reaction under hydrogen atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Shin-mura, Kiyoto; Otani, Yu; Ogawa, Seiya [Course of Mechanical Engineering, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Niwa, Eiki; Hashimoto, Takuya [Department of Physics, College of Humanities and Sciences, Nihon University, 3-8-1 Sakurajousui, Setagaya-ku, Tokyo 156-8550 (Japan); Hoshino, Tsuyoshi [Breeding Functional Materials Development Group, Department of Blanket Systems Research, Rokkasho Fusion Institute, Sector of Fusion Research and Development, Japan Atomic Energy Agency, 2-166 Obuchi, Omotedate, Rokkasho-mura, Kamikita-gun, Aomori 039-3212 (Japan); Sasaki, Kazuya, E-mail: k_sasaki@tokai-u.ac.jp [Course of Mechanical Engineering, Graduate School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan); Department of Prime Mover Engineering, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka, Kanagawa 259-1292 (Japan)

    2016-11-01

    Highlights: • A fine pure Li{sub 8}ZrO{sub 6} powder was synthesized by using Li{sub 2}CO{sub 3} and ZrO{sub 2} via a solid state reaction. • Influences on the purity of product powder, lattice defect, and crystal orientation were revealed. • The suitable synthesis conditions of the fine and high purity Li{sub 8}ZrO{sub 6} powder were found. • The reaction process of the synthesis of Li{sub 8}ZrO{sub 6} was estimated. - Abstract: Li{sub 8}ZrO{sub 6} contains a large amount of Li and has a significant potential as a tritium breeder. However, few syntheses of fine-grain, high-purity Li{sub 8}ZrO{sub 6} powder have been reported. In this study, a high-purity powder of Li{sub 8}ZrO{sub 6} was synthesized by solid state reaction under hydrogen atmosphere combined with an effective lithium source and a suitable initial Li:Zr molar ratio. Mixed powders of Li{sub 2}CO{sub 3} and ZrO{sub 2} were fired at around 630 °C in H{sub 2} for several hours and several firing cycles. The low firing temperature inhibited the vaporization of Li during the heating, so that excessive amounts of Li were not needed for the synthesis, and the Li:Zr ratio in the starting material was 10:1 (mol:mol). In this synthesis, Li{sub 2}O was generated via the decomposition of Li{sub 2}CO{sub 3} during firing in H{sub 2}, and reacted with ZrO{sub 2} to form Li{sub 6}Zr{sub 2}O{sub 7}, which reacted with itself to form Li{sub 8}ZrO{sub 6}.

  10. Super high-rate fabrication of high-purity carbon nanotube aerogels from floating catalyst method for oil spill cleaning

    Science.gov (United States)

    Khoshnevis, Hamed; Mint, Sandar Myo; Yedinak, Emily; Tran, Thang Q.; Zadhoush, Ali; Youssefi, Mostafa; Pasquali, Matteo; Duong, Hai M.

    2018-02-01

    In this study, we apply an advanced floating catalyst method to fabricate carbon nanotube (CNT) aerogels at super high deposition rate for oil spill cleaning. The aerogels consist of 3D porous network of stacking double-walled CNT bundles with low catalyst impurity (9%) and high thermal stability (650 °C). With high porosity, surface areas, and water contact angles, the CNT aerogels exhibit a high oil adsorption of up to 107 g/g and good reusability of up to four adsorption-burning cycles. This work suggests that the lightweight, porous, and super hydrophobic CNT aerogels can be promising sorbent materials for environmental applications.

  11. Development and validation of high performance liquid chromatography with a spectrophotometric detection method for the chemical purity and assay of nepafenac.

    Science.gov (United States)

    Lipiec-Abramska, Elżbieta; Jedynak, Łukasz; Formela, Adam; Roszczyński, Jacek; Cybulski, Marcin; Puchalska, Maria; Zagrodzka, Joanna

    2014-03-01

    The study is a proposition of the application of high performance liquid chromatography (HPLC) with a spectrophotometric UV range detector to analyze the chemical purity and assay of nepafenac, an active pharmaceutical ingredient (API). During literature search only a few publications were found about nepafenac. HPLC UV methods were mainly presented in patent documents about nepafenac synthesis and chemical purity. The presented method allows to separate all potential related compounds from nepafenac and to quantitate the nepafenac amount. As there is no official monograph in the pharmacopeias about nepafenac, the performed full validation procedure makes the method ready to use in routine analysis. The composition of the mobile phase (10mM ammonium formate, pH 4.1) and the HPLC column (Phenomenex Gemini-NX C18) were selected during the development step. Presented data confirm the benefits of the developed method. Four of the most potential impurities were validated as for the quantitative test and the rest of impurities were validated as for the limit test - according to ICH Q2(R1). The accuracy/recovery results for the chemical purity method are within 90-108%, in the case of assay studies from 99% to 101%; the limit of detection is as low as 15-30ng/mL. The linearity passes all statistical tests. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. A comparison of a novel robust decentralised control strategy and MPC for industrial high purity, high recovery, multicomponent distillation.

    Science.gov (United States)

    Udugama, Isuru A; Wolfenstetter, Florian; Kirkpatrick, Robert; Yu, Wei; Young, Brent R

    2017-07-01

    In this work we have developed a novel, robust practical control structure to regulate an industrial methanol distillation column. This proposed control scheme is based on a override control framework and can manage a non-key trace ethanol product impurity specification while maintaining high product recovery. For comparison purposes, a MPC with a discrete process model (based on step tests) was also developed and tested. The results from process disturbance testing shows that, both the MPC and the proposed controller were capable of maintaining both the trace level ethanol specification in the distillate (XD) and high product recovery (β). Closer analysis revealed that the MPC controller has a tighter XD control, while the proposed controller was tighter in β control. The tight XD control allowed the MPC to operate at a higher XD set point (closer to the 10ppm AA grade methanol standard), allowing for savings in energy usage. Despite the energy savings of the MPC, the proposed control scheme has lower installation and running costs. An economic analysis revealed a multitude of other external economic and plant design factors, that should be considered when making a decision between the two controllers. In general, we found relatively high energy costs favour MPC. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  13. TRACE MEASUREMENT OF CO, CH4, AND CO2 IN HIGH PURITY GASES BY GC-FID-METHANIZER: METHOD VALIDATION AND UNCERTAINTY ESTIMATION

    Directory of Open Access Journals (Sweden)

    Harry Budiman

    2017-10-01

    Full Text Available In this study, method validation and uncertainty estimation for the measurement of trace amounts gas impurities such as carbon monoxide (CO, methane (CH4, and carbon dioxide (CO2 using gas chromatography flame ionization detector with methanizer (GC-FID-methanizer are reported. The method validation was performed by investigating the following performance parameters such as selectivity, limit of detection (LOD, limit of quantification (LOQ, precision, linearity, accuracy, and robustness. The measurement uncertainty to indicate the degree of confidence of the analytical results was estimated by using a bottom up approach. The results reveals that the method possess good repeatability (% relative standard deviation RSD < 1 % and intermediate precision (RSD % < 5 % properties for the measurement of trace level CO, CH4, and CO2. No bias was found for the validated method. The linearity of the method was found to be remarkable with correlation coefficient (R2 higher than 0.995 for all target analytes. In addition, the measurement uncertainty of the CO, and CO2 in high purity helium (He gas sample measured using the validated method were found to be 0.08 µmol∙mol-1, and 0.11 µmol∙mol-1, respectively, at 95 % of confidence level. No measurement uncertainty was obtained for CH4 in high purity gas sample due to its concentration was below the GC-FID-methanizer detection level. In conclusion, the GC-FID-methanizer under experimental condition of this study is reliable and fit for the measurement of trace levels of CO, CH4 and CO2 in high purity gas samples.

  14. A study on the influence of trace elements (C, S, B, Al, N) on the hot ductility of the high purity austenitic alloy Fe-Ni 36% (INVAR)

    Energy Technology Data Exchange (ETDEWEB)

    Simonetta-Perrot, M.T.

    1994-11-01

    In order to study the damage mechanisms leading to the ductility decrease of the Invar alloy at 600 C, a high-purity Fe-Ni 36% sample has been doped with trace elements with the purpose of identifying the role of sulfur, sulfur with Al N or B N precipitates and sulfur with boron, on the ductility, the failure modes, the intergranular damage and the plastic deformation mechanisms prior to failure. A new AES segregation quantification method has been used to study the kinetics and thermodynamics of intergranular and surface segregations and determine the relation between sulfur segregation and grain joint fragility. refs., figs., tabs.

  15. Effects of 600 MeV proton irradiation on nucleation and growth of precipitates and helium bubbles in a high-purity Al-Mg-Si alloy

    DEFF Research Database (Denmark)

    Singh, Bachu Narain; Leffers, Torben; Victoria, M.

    1986-01-01

    bubbles were seen in the grain interior as well as at the grain boundaries. Long rows of bubbles were observed with the same orientation in the matrix as the precipitate needles. Grain boundary bubbles were found to grow faster in the Al-Mg-Si alloy than in the high-purity aluminium...... to have dissolved during the later stages of irradiation. Thermally aged reference specimens have also been investigated. The needle-shaped precipitates in the aged and the irradiated specimens lie along the 〈100〉 matrix directions. At 150°C bubbles were observed only at grain boundaries whereas at 240°C...

  16. Simplified NaCl based (68)Ga concentration and labeling procedure for rapid synthesis of (68)Ga radiopharmaceuticals in high radiochemical purity.

    Science.gov (United States)

    Mueller, Dirk; Klette, Ingo; Baum, Richard P; Gottschaldt, M; Schultz, Michael K; Breeman, Wouter A P

    2012-08-15

    A simple sodium chloride (NaCl) based (68)Ga eluate concentration and labeling method that enables rapid, high-efficiency labeling of DOTA conjugated peptides in high radiochemical purity is described. The method utilizes relatively few reagents and comprises minimal procedural steps. It is particularly well-suited for routine automated synthesis of clinical radiopharmaceuticals. For the (68)Ga generator eluate concentration step, commercially available cation-exchange cartridges and (68)Ga generators were used. The (68)Ga generator eluate was collected by use of a strong cation exchange cartridge. 98% of the total activity of (68)Ga was then eluted from the cation exchange cartridge with 0.5 mL of 5 M NaCl solution containing a small amount of 5.5 M HCl. After buffering with ammonium acetate, the eluate was used directly for radiolabeling of DOTATOC and DOTATATE. The (68)Ga-labeled peptides were obtained in higher radiochemical purity compared to other commonly used procedures, with radiochemical yields greater than 80%. The presence of (68)Ge could not be detected in the final product. The new method obviates the need for organic solvents, which eliminates the required quality control of the final product by gas chromatography, thereby reducing postsynthesis analytical effort significantly. The (68)Ga-labeled products were used directly, with no subsequent purification steps, such as solid-phase extraction. The NaCl method was further evaluated using an automated fluid handling system and it routinely facilitates radiochemical yields in excess of 65% in less than 15 min, with radiochemical purity consistently greater than 99% for the preparation of (68)Ga-DOTATOC.

  17. Preparation of High Purity, High Molecular-Weight Chitin from Ionic Liquids for Use as an Adsorbate for the Extraction of Uranium from Seawater

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, Robin [Univ. of Alabama, Tuscaloosa, AL (United States)

    2013-12-21

    Ensuring a domestic supply of uranium is a key issue facing the wider implementation of nuclear power. Uranium is mostly mined in Kazakhstan, Australia, and Canada, and there are few high-grade uranium reserves left worldwide. Therefore, one of the most appealing potential sources of uranium is the vast quantity dissolved in the oceans (estimated to be 4.4 billion tons worldwide). There have been research efforts centered on finding a means to extract uranium from seawater for decades, but so far none have resulted in an economically viable product, due in part to the fact that the materials that have been successfully demonstrated to date are too costly (in terms of money and energy) to produce on the necessary scale. Ionic Liquids (salts which melt below 100{degrees}C) can completely dissolve raw crustacean shells, leading to recovery of a high purity, high molecular weight chitin powder and to fibers and films which can be spun directly from the extract solution suggesting that continuous processing might be feasible. The work proposed here will utilize the unprecedented control this makes possible over the chitin fiber a) to prepare electrospun nanofibers of very high surface area and in specific architectures, b) to modify the fiber surfaces chemically with selective extractant capacity, and c) to demonstrate their utility in the direct extraction and recovery of uranium from seawater. This approach will 1) provide direct extraction of chitin from shellfish waste thus saving energy over the current industrial process for obtaining chitin; 2) allow continuous processing of nanofibers for very high surface area fibers in an economical operation; 3) provide a unique high molecular weight chitin not available from the current industrial process, leading to stronger, more durable fibers; and 4) allow easy chemical modification of the large surface areas of the fibers for appending uranyl selective functionality providing selectivity and ease of stripping. The

  18. Synthesis of high-purity phthalocyanines (pc): High intrinsic conductivities in the molecular conductors H[sub 2](pc)I and Ni(pc)I

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, J.A.; Murata, K.; Miller, D.C.; Stanton, J.L.; Broderick, W.E.; Hoffman, B.M.; Ibers, J.A. (Northwestern Univ., Evanston, IL (United States))

    1993-08-04

    The authors show that one can prepare M(pc)I crystals, M = [open quotes]H[sub 2][close quotes] and Ni, with remarkably improved charge-transport properties by carefully avoiding impurities in the preparation of the M(pc) precursors. The purest H[sub 2](pc) (<60 ppm free-radical impurities) was prepared by a melt method in quartz and Teflon vessels while very pure Ni(pc) (170-250 pm) could only be obtained by metalation of the pure H[sub 2](pc). Template syntheses of Ni(pc) result in impure material and are to be discouraged for applications requiring very pure M(pc) materials. H[sub 2](pc)I and Ni(pc)I synthesized from the high-purity precursors remain metallic down to ca. 3 K, a far lower temperature than ever before observed. At this temperature the conductivities exhibit maximum values that are ca. 30-fold greater than at room temperature, not 5-7-fold as seen before, with absolute values of [sigma] [approximately] (1-2) [times] 10[sup 4] [Omega][sup [minus]1] cm[sup [minus]1]. The study of a series of Ni(pc)I compounds prepared from Ni(pc) parent materials exhibiting a range of purity levels further shows a strong correlation between the charge-transport properties and the level of paramagnetic impurities in the macrocycle precursor. However, the maximum conductivity appears to saturate at the lowest impurity concentrations, which suggests that the behavior exhibited by the best materials prepared are representative for the first time of the limiting, intrinsic charge-transport properties of H[sub 2](pc)I and Ni(pc)I. A full structure report for H[sub 2](pc)I-1 is presented also. The structure consists of metal-over-metal stacks of partially oxidized H[sub 2](pc) groups surrounded by linear chains of triiodide anions. H[sub 2](pc)I crystallizes with two formula units in the tetragonal space group D[sub 4h][sup 2]-P4/mcc with a = 13.931 [angstrom], c = 6.411 [angstrom], and V = 1244.2 [angstrom][sup 3] (T = 108 K).

  19. Cyclotron production of high purity (44m,44)Sc with deuterons from (44)CaCO3 targets.

    Science.gov (United States)

    Alliot, C; Kerdjoudj, R; Michel, N; Haddad, F; Huclier-Markai, S

    2015-06-01

    Due to its longer half-life, (44)Sc (T1/2 = 3.97 h) as a positron emitter can be an interesting alternative to (68)Ga (T1/2 = 67.71 min). It has been already proposed as a PET radionuclide for scouting bone disease and is already available as a (44)Ti/(44)Sc generator. (44)Sc has an isomeric state, (44 m)Sc (T1/2 = 58.6 h), which can be co-produced with (44)Sc and that has been proved to be considered as an in-vivo PET generator (44 m)Sc/(44)Sc. This work presents the production route of (44 m)Sc/(44)Sc generator from (44)Ca(d,2n), its extraction/purification process and the evaluation of its performances. Irradiation was performed in a low activity target station using a deuteron beam of 16 MeV, which favors the number of (44 m)Sc atoms produced simultaneously to (44)Sc. Typical irradiation conditions were 60 min at 0.2 μA producing 44 MBq of (44)Sc with a (44)Sc/(44 m)Sc activity ratio of 50 at end of irradiation. Separations of the radionuclides were performed by means of cation exchange chromatography using a DGA® resin (Triskem). Then, the developed process was applied with bigger targets, and could be used for preclinical studies. The extraction/purification process leads to a radionucleidic purity higher than 99.99% ((43)Sc, (46)Sc, (48)Sc < DL). (44 m)Sc/(44)Sc labeling towards DOTA moiety was performed in order to get an evaluation of the specific activities that could be reached with regard to all metallic impurities from the resulting source. Reaction parameters of radiolabeling were optimized, reaching yields over 95%, and leading to a specific activity of about 10-20 MBq/nmol for DOTA. A recycling process for the enriched (44)Ca target was developed and optimized. The quality of the final batch with regard to radionucleidic purity, specific activity and metal impurities allowed a right away use for further radiopharmaceutical evaluation. This radionucleidic pair of (44 m)Sc/(44)Sc offers a quite interesting PET radionuclide for being further

  20. Temporal characterization of plasma cw high-power CO2 laser-matter interaction: contribution to the welding process control

    Science.gov (United States)

    Engel, Thierry; Kane, M.; Fontaine, Joel

    1997-08-01

    During high-power laser welding, gas ionization occurs above the sample. The resulting plasma ignition threshold is related to ionization potential of metallic vapors from the sample, and shielding gases used in the process. In this work, we have characterized the temporal behavior of the radiation emitted by the plasma during laser welding in order to relate the observed signals to the process parameters.

  1. A new (68)Ga anionic concentration and purification method for automated synthesis of [(68)Ga]-DOTA or NODAGA conjugated peptides in high radiochemical purity.

    Science.gov (United States)

    Ben Azzouna, Rana; Alshoukr, Faisal; Leygnac, Sébastien; Guez, Alexandre; Gonzalez, Walter; Rousseaux, Olivier; Guilloteau, Denis; Le Guludec, Dominique

    2015-08-01

    The (68)Ge/(68)Ga generator is of increasing interest for clinical PET. For successful labelling, the eluate has to be purified. The aim of our approach is to improve the existing anionic methods which have a number of advantages compared to other methods but which use high concentrated HCl, and require an additional anionizing step. A new (68)Ga-eluate anionic purification method that enables rapid and high efficiency labelling of DOTA and NODAGA conjugated peptides in high radiochemical purity is described. The new method uses NaCl as an alternative Cl(-) source to the corrosive HCl and combines the three standard steps in a single step. The recovery yield was ≥90%, and the (68)Ge breakthrough was in conformity with the European Pharmacopeia limit. An automated labelling of DOTA and NODAGA-conjugated peptides was performed with the new method, using acetate sodium buffer, with a total duration of 13 min and a radiochemical yield >85%. The labelled peptides have a radiochemical purity exceeding 99% and can be used directly without any further purification step and without the quality control by gas chromatography. Furthermore, the new method has an economic advantage: it offers the possibility to use generator until 20 months after the calibration date. Copyright © 2015 John Wiley & Sons, Ltd.

  2. Obtention of high purity silica from the flotation waste of itabiritic ore; Obtencao de silica de elevada pureza a partir do rejeito de flotacao de um minerio itabiritico

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Polyana Fabricia Fernandes

    2016-10-01

    Banded iron formations are exploited as iron mineral in 'Quadrilatero Ferrifero' of Minas Gerais (MG) State, Brazil. About half of the amount of extracted material becomes tailings, which are stored in tailing dams or used for filling mining pits. Tens of thousands of tons are generated daily in operating mines in this region, causing concern about the environmental liabilities, and costs to manage the tailing dams. Miners are committed to finding uses for these wastes in other productive chains. This thesis aimed to obtain high purity silica from the flotation tailings of banded iron formations using classical techniques for ore processing, such as particle size classification and magnetic separation, followed by hydrometallurgical leaching, also alkaline fusion and chemical precipitation. The tailings samples was collected in the tailings dam of Peak Mine operated by Vale A.S., in Itabirito – MG. This sample had initially 33.4% by weight SiO{sub 2}, 57.4% wt Fe{sub 2}O{sub 3} and 8.31% wt Al{sub 2}O{sub 3}. After desliming for disposal of the fine particles (-37μm) the composition was 68.0% SiO{sub 2}, 31.4% Fe{sub 2}O{sub 3} and 0.50% Al{sub 2}O{sub 3}. After magnetic separation, the composition was 93.8% SiO{sub 2}, 1.16% Fe{sub 2}O{sub 3} and 3.80% Al{sub 2}O{sub 3}. After acid leaching l or digestion to remove impurities, it was possible to obtain silica with 98% purity. The fusion with sodium hydroxide, followed by alkaline leaching of sodium silicate and silica precipitation gave purities of about 99.5%. Values even higher may be possible with optimization of the parameters of alkaline fusion or by repeating the process from the product with purity of 99.5%. The iron oxide content and the aluminum main contaminants were 0.01% and 0.07%, respectively. Amorphous silica was obtained with high specific surface (322 m{sup 2}/g) and particle size less than 200 nm. Depending on the application, a control should be made for the impurities, such as

  3. Tm3+-doped CW fiber laser based on a highly GeO2-doped dispersion-shifted fiber

    OpenAIRE

    Dvoyrin, Vladislav; Sorokina, Irina T; Mashinsky, Valery M.; Ischakova, Lyudmila D.; Dianov, Evgenii M; Kalashnikov, Valdimir L; Yashkov, Mikhail V.; Khopin, Vladimir F.; Guryanov, Aleksey N.

    2011-01-01

    A novel all-fiber laser based on a highly GeO2-doped dispersion-shifted Tm-codoped fiber, pumped at 1.56 µm wavelength and lasing at 1.862 µm wavelength with a slope efficiency up to 37% was demonstrated. The single-mode Tm-doped fiber with the 55GeO2-45SiO2 core was fabricated for the first time by MCVD technique. The laser produces spectral side bands, resulting from the four-wave mixing owing to the shift of the zero-dispersion-wavelength of the fiber to the laser wavelength, thus, making ...

  4. Large-scale isolation of CD34+ cells using the Amgen cell selection device results in high levels of purity and recovery.

    Science.gov (United States)

    McNiece, I; Briddell, R; Stoney, G; Kern, B; Zilm, K; Recktenwald, D; Miltenyi, S

    1997-02-01

    The Amgen Cell Selection Device (ACSD) is a fully automated system based on the research scale magnetic-activated cell separation (MACS) system (Miltenyi Biotech GmbH, Bergisch Gladbach, Germany) for the selection of CD34+ cells. Leukapheresis products (LP) (n = 30) from normal donors mobilized with recombinant human granulocyte colony-stimulating factor (rhG-CSF) were selected with the ACSD to evaluate the performance of this system. The starting LP contained a median of 0.51% CD34+ cells (range 0.21%-1.54%) and a median WBC count of 3.0 x 10(10) (range 1-4.7 x 10(10) cells). After selection on the ACSD a mean purity of 91.5% +/- 0.6% CD34+ cells was obtained, with a median purity of 95.5% CD34+ cells. A median of 98 x 10(6) total CD34+ cells were recovered postselection, with a range of 31-323 x 10(6) cells collected from the LP. This represented a mean recovery of 81.7% +/- 6% of CD34+ cells and a median of 78% compared with starting CD34+ cell numbers in the LP. FACS analysis of the selected products demonstrated a 4-5 log depletion of T cell subsets, including CD3, CD4, CD8, and CD56 subsets. These data demonstrate the high performance obtained with the ACSD resulting in a final product of greater than 90% purity of CD34+ cells. CD34+ cells selected with the ACSD represent an ideal product for clinical applications, such as tumor cell purging, T cell depletion for allogeneic transplant, ex vivo expansion, and gene therapy.

  5. Dynamical recrystallization of high purity austenitic stainless steels; Recristallisation dynamique d'aciers inoxydables austenitiques de haute purete

    Energy Technology Data Exchange (ETDEWEB)

    Gavard, L

    2001-01-01

    The aim of this work is to optimize the performance of structural materials. The elementary mechanisms (strain hardening and dynamical regeneration, germination and growth of new grains) occurring during the hot working of metals and low pile defect energy alloys have been studied for austenitic stainless steels. In particular, the influence of the main experimental parameters (temperature, deformation velocity, initial grain size, impurities amount, deformation way) on the process of discontinuous dynamical recrystallization has been studied. Alloys with composition equal to those of the industrial stainless steel-304L have been fabricated from ultra-pure iron, chromium and nickel. Tests carried out in hot compression and torsion in order to cover a wide range of deformations, deformation velocities and temperatures for two very different deformation ways have allowed to determine the rheological characteristics (sensitivity to the deformation velocity, apparent activation energy) of materials as well as to characterize their microstructural deformations by optical metallography and electron back-scattered diffraction. The influence of the initial grain size and the influence of the purity of the material on the dynamical recrystallization kinetics have been determined. An analytical model for the determination of the apparent mobility of grain boundaries, a semi-analytical model for the dynamical recrystallization and at last an analytical model for the stationary state of dynamical recrystallization are proposed as well as a new criteria for the transition between the refinement state and the state of grain growth. (O.M.)

  6. An efficient method for high-purity anthocyanin isomers isolation from wild blueberries and their radical scavenging activity.

    Science.gov (United States)

    Chorfa, Nasima; Savard, Sylvain; Belkacemi, Khaled

    2016-04-15

    An efficient process for the purification of anthocyanin monomeric isomers from wild blueberries of Lake Saint-Jean region (Quebec, Canada) was developed and easy scalable at industrial purpose. The blueberries were soaked in acidified ethanol, filtered, and the filtrate was cleaned by solid phase extraction using silica gel C-18 and DSC-SCX cation-exchange resin. Anthocyanin-enriched elutes (87 wt.%) were successfully fractionated by preparative liquid chromatography. The major anthocyanins mono-galactoside, -glucoside and -arabinoside isomers of delphinidin, cyanidin, petunidin, peonidin and malvidin were isolated with a purity up to 100% according to their LC-MS and (1)H NMR spectra. The oxygen radical absorbance capacity (ORAC) of the obtained pure anthocyanins was evaluated. Delphinidin-3-galactoside has the highest capacity (13.062 ± 2.729 μmol TE/μmol), and malvidin-3-glucoside the lowest (0.851 ± 0.032 μmol TE/μmol). A mechanistic pathway preview is suggested for the anthocyanins scavenging free radical activity by hydrogen transfer. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Jerusalem artichoke powder: a useful material in producing high-optical-purity l-lactate using an efficient sugar-utilizing thermophilic Bacillus coagulans strain.

    Science.gov (United States)

    Wang, Limin; Xue, Zhangwei; Zhao, Bo; Yu, Bo; Xu, Ping; Ma, Yanhe

    2013-02-01

    Jerusalem artichoke is a low-requirement crop, which does not interfere with food chain, and is a promising carbon source for industrial fermentation. Microbial conversion of such a renewable raw material to useful products, such as lactic acid, is an important objective in industrial biotechnology. In this study, high-optical-purity l-lactate was efficiently produced from the hydrolysates of Jerusalem artichoke powder by a thermophilic bacterium, Bacillus coagulans XZL4. High l-lactate production (134gl(-1)) was obtained using 267gl(-1) Jerusalem artichoke powder (total reducing sugars of 140gl(-1)) and 10gl(-1) of corn steep powder in fed-batch fermentation, with an average productivity of 2.5gl(-1)h(-1) and a yield of 0.96gg(-1) reducing sugars. The final product optical purity is 99%, which meets the requirement of lactic acid polymerization. Our study represents a cost-effective and promising method for polymer-grade l-lactate production using a cheap raw bio-resource. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. A novel high color purity blue-emitting phosphor: CaBi{sub 2}B{sub 2}O{sub 7}:Tm{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jiangong, E-mail: lijiangong01@gmail.com [Department of Electronic Science and Engineering, Huanghuai University, Zhumadian 463000 (China); Yan, Huifang [Department of Foreign Languages and Literature, Huanghuai University, Zhumadian 463000 (China); Yan, Fengmei [Department of Chemistry and Chemical Engineering, Huanghuai University, Zhumadian 463000 (China)

    2016-07-15

    Graphical abstract: - Highlights: • A series of Tm{sup 3+}-doped CaBi{sub 2}B{sub 2}O{sub 7} blue-emitting phosphors were prepared. • The optimum doping content of Tm{sup 3+} ions was found. • The critical distance and concentration quenching mechanism was discussed. • The color purity of as prepared sample was analyzed and compared. - Abstract: A series of Tm{sup 3+}-doped CaBi{sub 2−x}B{sub 2}O{sub 7}:xTm{sup 3+} (0.02 ≤ x ≤ 0.12) blue-emitting phosphors with high color purity were prepared by solid-state reaction method. The crystal structure and luminescence properties of the as-prepared phosphors were studied. This phosphor shows a satisfactory blue performance (peak at 453 nm) due to the {sup 1}D{sub 2} → {sup 3}F{sub 4} transition of Tm{sup 3+} excited by 357 nm light. Investigation of Tm{sup 3+} content dependent emission spectra indicates that x = 0.04 is the optimum doping content of Tm{sup 3+} ions in the CaBi{sub 2}B{sub 2}O{sub 7} host. The critical distance and the concentration quenching mechanism were also investigated. In particular, the color purity of as prepared sample was analyzed and the result shows that the color purity of CaBi{sub 2}B{sub 2}O{sub 7}:Tm{sup 3+} is higher than the commercial blue phosphor BaMgAl{sub 10}O{sub 17}:Eu{sup 2+} (BAM:Eu{sup 2+}) and the latest reported Tm{sup 3+} doped blue phosphors. The present work suggests that the CaBi{sub 2}B{sub 2}O{sub 7}:Tm{sup 3+} phosphor is a potential blue-emitting candidate for the application in the near-UV WLEDs.

  9. High-effective denitrification of low C/N wastewater by combined constructed wetland and biofilm-electrode reactor (CW-BER).

    Science.gov (United States)

    He, Yuan; Wang, Yuhui; Song, Xinshan

    2016-03-01

    The low denitrification effect on constructed wetlands (CWs) treating low carbon to nitrogen ratio (C/N) wastewater was a problem. In this study, a novel coupled system by installing CW and biofilm-electrode reactor (CW-BER) was developed. In this system, the heterotrophic and autotrophic denitrifying bacteria all played their roles in denitrification process. The system was investigated systematically with simulated wastewater at different C/Ns, electric current intensities (I), hydraulic retention times (HRTs), and pH. Results showed that the optimum running conditions were C/N=0.75-1, I=15 mA, HRT=12 h, and pH=7.5. The highest removal efficiency of NO3-N and TN at the best conditions was respectively 63.03% and 98.11% for CW-BER. Also, the TN and NO3-N enhancive removal efficiency of CW-BER was 23.26% and 24.20%, respectively. No residual organic carbon source was detected in final effluent at the best parameters. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. High temperature annealing effects on deep-level defects in a high purity semi-insulating 4H-SiC substrate

    Science.gov (United States)

    Iwamoto, Naoya; Azarov, Alexander; Ohshima, Takeshi; Moe, Anne Marie M.; Svensson, Bengt G.

    2015-07-01

    Effects of high-temperature annealing on deep-level defects in a high-purity semi-insulating 4H silicon carbide substrate have been studied by employing current-voltage, capacitance-voltage, junction spectroscopy, and chemical impurity analysis measurements. Secondary ion mass spectrometry data reveal that the substrate contains boron with concentration in the mid 1015 cm-3 range, while other impurities including nitrogen, aluminum, titanium, vanadium and chromium are below their detection limits (typically ˜1014 cm-3). Schottky barrier diodes fabricated on substrates annealed at 1400-1700 °C exhibit metal/p-type semiconductor behavior with a current rectification of up to 8 orders of magnitude at bias voltages of ±3 V. With increasing annealing temperature, the series resistance of the Schottky barrier diodes decreases, and the net acceptor concentration in the substrates increases approaching the chemical boron content. Admittance spectroscopy results unveil the presence of shallow boron acceptors and deep-level defects with levels in lower half of the bandgap. After the 1400 °C annealing, the boron acceptor still remains strongly compensated at room temperature by deep donor-like levels located close to mid-gap. However, the latter decrease in concentration with increasing annealing temperature and after 1700 °C, the boron acceptor is essentially uncompensated. Hence, the deep donors are decisive for the semi-insulating properties of the substrates, and their thermal evolution limits the thermal budget for device processing. The origin of the deep donors is not well-established, but substantial evidence supporting an assignment to carbon vacancies is presented.

  11. High performance liquid chromatography with photo diode array for separation and analysis of naproxen and esomeprazole in presence of their chiral impurities: Enantiomeric purity determination in tablets.

    Science.gov (United States)

    Ragab, Marwa A A; El-Kimary, Eman I

    2017-05-12

    A stereoselective high performance liquid chromatographic method with diode array detection (HPLC-DAD) was introduced for S-naproxen and esomeprazole determination in tablets. The separation was achieved on a Kromasil Cellucoat chiral column using a mobile phase consisting of hexane: isopropanol: trifluoroacetic acid (TFA) (90:9.9:0.1 v/v/v). The proposed system was found to be suitable for the enantioseparation of naproxen and omeprazole biologically active isomers. After optimization of the chromatographic conditions, resolution values of 3.84 and 2.17 could be obtained for naproxen and omeprazole isomers, respectively. The method was fully validated for the determination of S-isomers of each drug in their dosage form. Also, the enentiomeric purity was determined in commercial tablet containing S-naproxen and esomeprazole. The enantiomeric purity was calculated for each drug and the chiral impurities (R-isomers) could be determined at 1% level. The method was validated and good results with respect to linearity, precision, accuracy, selectivity and robustness were obtained. The limits of detection (LOD) and quantification (LOQ) were 2.00, 6.50 and 0.10, 0.35μgmL -1 for S-naproxen and esomeprazole, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Efficient out-coupling of high-purity single photons from a coherent quantum dot in a photonic-crystal cavity

    DEFF Research Database (Denmark)

    Madsen, Kristian Høeg; Ates, Serkan; Liu, J.

    2014-01-01

    We demonstrate a single-photon collection efficiency of (44.3 ± 2.1)% from a quantum dot in a low-Q mode of a photonic-crystal cavity with a single-photon purity of g(2)(0) = (4 ± 5)% recorded above the saturation power. The high efficiency is directly confirmed by detecting up to 962 ± 46...... kilocounts per second on a single-photon detector on another quantum dot coupled to the cavity mode. The high collection efficiency is found to be broadband, as is explained by detailed numerical simulations. Cavity-enhanced efficient excitation of quantum dots is obtained through phonon-mediated excitation...... and under these conditions, single-photon indistinguishability measurements reveal long coherence times reaching 0.77 ± 0.19 ns in a weak-excitation regime. Our work demonstrates that photonic crystals provide a very promising platform for highly integrated generation of coherent single photons including...

  13. An improved back-flush-to-vent gas chromatographic method for determination of trace permanent gases and carbon dioxide in ultra-high purity ammonia.

    Science.gov (United States)

    Trubyanov, Maxim M; Mochalov, Georgy M; Vorotyntsev, Ilya V; Vorotyntsev, Andrey V; Suvorov, Sergey S; Smirnov, Konstantin Y; Vorotyntsev, Vladimir M

    2016-05-20

    A novel method for rapid, quantitative determination of trace permanent gases and carbon dioxide in ultra-high purity ammonia by dual-channel two-dimensional GC-PDHID is presented. An improved matrix back-flush-to-vent approach combining back-flush column switching technique with auxiliary NaHSO4 ammonia trap is described. The NaHSO4 trap prevents traces of ammonia from entering the analytical column and is shown not to affect the impurity content of the sample. The approach allows shortening the analysis time and increasing the amount of measurements without extensive maintenance of the GC-system. The performance of the configuration has been evaluated utilizing ammonia- and helium-based calibration standards. The method has been applied for the analysis of 99.9999+% ammonia purified by high-pressure distillation at the production site. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Rapid Production of High-Purity Hydrogen Fuel through Microwave-Promoted Deep Catalytic Dehydrogenation of Liquid Alkanes with Abundant Metals.

    Science.gov (United States)

    Jie, Xiangyu; Gonzalez-Cortes, Sergio; Xiao, Tiancun; Wang, Jiale; Yao, Benzhen; Slocombe, Daniel R; Al-Megren, Hamid A; Dilworth, Jonathan R; Thomas, John M; Edwards, Peter P

    2017-08-14

    Hydrogen as an energy carrier promises a sustainable energy revolution. However, one of the greatest challenges for any future hydrogen economy is the necessity for large scale hydrogen production not involving concurrent CO2 production. The high intrinsic hydrogen content of liquid-range alkane hydrocarbons (including diesel) offers a potential route to CO2 -free hydrogen production through their catalytic deep dehydrogenation. We report here a means of rapidly liberating high-purity hydrogen by microwave-promoted catalytic dehydrogenation of liquid alkanes using Fe and Ni particles supported on silicon carbide. A H2 production selectivity from all evolved gases of some 98 %, is achieved with less than a fraction of a percent of adventitious CO and CO2 . The major co-product is solid, elemental carbon. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Triggered high-purity telecom-wavelength single-photon generation from p-shell-driven InGaAs/GaAs quantum dot.

    Science.gov (United States)

    Dusanowski, Ł; Holewa, P; Maryński, A; Musiał, A; Heuser, T; Srocka, N; Quandt, D; Strittmatter, A; Rodt, S; Misiewicz, J; Reitzenstein, S; Sęk, G

    2017-12-11

    We report on the experimental demonstration of triggered single-photon emission at the telecom O-band from In(Ga)As/GaAs quantum dots (QDs) grown by metal-organic vapor-phase epitaxy. Micro-photoluminescence excitation experiments allowed us to identify the p-shell excitonic states in agreement with high excitation photoluminescence on the ensemble of QDs. Hereby we drive an O-band-emitting GaAs-based QD into the p-shell states to get a triggered single photon source of high purity. Applying pulsed p-shell resonant excitation results in strong suppression of multiphoton events evidenced by the as measured value of the second-order correlation function at zero delay of 0.03 (and ~0.005 after background correction).

  16. A combined arc-melting and tilt-casting furnace for the manufacture of high-purity bulk metallic glass materials

    Science.gov (United States)

    Soinila, E.; Pihlajamäki, T.; Bossuyt, S.; Hänninen, H.

    2011-07-01

    An arc-melting furnace which includes a tilt-casting facility was designed and built, for the purpose of producing bulk metallic glass specimens. Tilt-casting was chosen because reportedly, in combination with high-purity processing, it produces the best fatigue endurance in Zr-based bulk metallic glasses. Incorporating the alloying and casting facilities in a single piece of equipment reduces the amount of laboratory space and capital investment needed. Eliminating the sample transfer step from the production process also saves time and reduces sample contamination. This is important because the glass forming ability in many alloy systems, such as Zr-based glass-forming alloys, deteriorates rapidly with increasing oxygen content of the specimen. The challenge was to create a versatile instrument, in which high purity conditions can be maintained throughout the process, even when melting alloys with high affinity for oxygen. Therefore, the design provides a high-vacuum chamber to be filled with a low-oxygen inert atmosphere, and takes special care to keep the system hermetically sealed throughout the process. In particular, movements of the arc-melting electrode and sample manipulator arm are accommodated by deformable metal bellows, rather than sliding O-ring seals, and the whole furnace is tilted for tilt-casting. This performance of the furnace is demonstrated by alloying and casting Zr55Cu30Al10Ni5 directly into rods up to ø 10 mm which are verified to be amorphous by x-ray diffraction and differential scanning calorimetry, and to exhibit locally ductile fracture at liquid nitrogen temperature.

  17. Large Scale CW ECRH Systems: Some considerations

    Directory of Open Access Journals (Sweden)

    Turkin Y.

    2012-09-01

    Full Text Available Electron Cyclotron Resonance Heating (ECRH is a key component in the heating arsenal for the next step fusion devices like W7-X and ITER. These devices are equipped with superconducting coils and are designed to operate steady state. ECRH must thus operate in CW-mode with a large flexibility to comply with various physics demands such as plasma start-up, heating and current drive, as well as configurationand MHD - control. The request for many different sophisticated applications results in a growing complexity, which is in conflict with the request for high availability, reliability, and maintainability. ‘Advanced’ ECRH-systems must, therefore, comply with both the complex physics demands and operational robustness and reliability. The W7-X ECRH system is the first CW- facility of an ITER relevant size and is used as a test bed for advanced components. Proposals for future developments are presented together with improvements of gyrotrons, transmission components and launchers.

  18. Ring-opening metathesis polymerization with the second generation Hoveyda-Grubbs catalyst: an efficient approach toward high-purity functionalized macrocyclic oligo(cyclooctene)s.

    Science.gov (United States)

    Blencowe, Anton; Qiao, Greg G

    2013-04-17

    Herein, we present a facile and general strategy to prepare functionalized macrocyclic oligo(cyclooctene)s (cOCOEs) in high purity and high yield by exploiting the ring-opening metathesis polymerization (ROMP) intramolecular backbiting process with the commercially available second generation Hoveyda-Grubbs (HG2) catalyst. In the first instance, ROMP of 5-acetyloxycyclooct-1-ene (ACOE) followed by efficient quenching and removal of the catalyst using an isocyanide derivative afforded macrocyclic oligo(5-acetyloxycyclooct-1-ene) (cOACOE) in high yield (95%), with a weight-average molecular weight (Mw) of 1.6 kDa and polydispersity index (PDI) of 1.6, as determined by gel permeation chromatography (GPC). The structure and purity of the macrocycles were confirmed by NMR spectroscopy and elemental analysis, which indicated the complete absence of end-groups. This was further supported by GPC-matrix assisted laser desorption ionization time-of-flight mass spectroscopy (GPC-MALDI ToF MS), which revealed the exclusive formation of macrocyclic derivatives composed of up to 45 repeat units. Complete removal of residual ruthenium from the macrocycles was confirmed by inductively coupled plasma atomic emission spectroscopy (ICP-AES). The same methodology was subsequently extended to the ROMP of 5-bromocyclooct-1-ene and 1,5-cyclooctadiene to prepare their macrocyclic derivatives, which were further derivatized to produce a library of functionalized macrocyclic oligo(cyclooctene)s. A comparative study using the second and third generation Grubbs catalysts in place of the HG2 catalyst for the polymerization of ACOE provided macrocycles contaminated with linear species, thus indicating that the bidendate benzylidene ligand of the Hoveyda-Grubbs catalyst plays an important role in the observed product distributions.

  19. Integrated Approach To Producing High-Purity Trehalose from Maltose by the Yeast Yarrowia lipolytica Displaying Trehalose Synthase (TreS) on the Cell Surface.

    Science.gov (United States)

    Li, Ning; Wang, Hengwei; Li, Lijuan; Cheng, Huiling; Liu, Dawen; Cheng, Hairong; Deng, Zixin

    2016-08-10

    An alternative strategy that integrated enzyme production, trehalose biotransformation, and bioremoval in one bioreactor was developed in this study, thus simplifying the traditional procedures used for trehalose production. The trehalose synthase gene from a thermophilic archaea, Picrophilus torridus, was first fused to the YlPir1 anchor gene and then inserted into the genome of Yarrowia lipolytica, thus yielding an engineered yeast strain. The trehalose yield reached 73% under optimal conditions. The thermal and pH stabilities of the displayed enzyme were improved compared to those of its free form purified from recombinant Escherichia coli. After biotransformation, the glucose byproduct and residual maltose were directly fermented to ethanol by a Saccharomyces cerevisiae strain. Ethanol can be separated by distillation, and high-purity trehalose can easily be obtained from the fermentation broth. The results show that this one-pot procedure is an efficient approach to the economical production of trehalose from maltose.

  20. Un método reproducible para obtener peg biramificado monofuncional de alta pureza A reproducible method for obtaining a 2-arms monofunctional peg with high purity

    Directory of Open Access Journals (Sweden)

    José A. Ramón

    2009-01-01

    Full Text Available PEGylation has become a widely applied technique to enhancing in vitro and in vivo stability of therapeutic proteins and to increasing materials biocompatibility. PEG branched structures have proven useful for protein and peptide modification. Furthermore, they may be better than linear structures for many purposes. This paper describes an improved procedure for obtaining 2-arms PEG based on L-lysine. The efficiency of the synthesis was not related to moisture of the raw materials. This procedure does not use hazardous reagents as previous protocols do. It implemented a purification process for obtaining the desired structure with high purity ( > 99%. Finally, the procedure described here allows the obtaining of others PEGylation reagents.

  1. Preparation of High Purity V2O5 from a Typical Low-Grade Refractory Stone Coal Using a Pyro-Hydrometallurgical Process

    Directory of Open Access Journals (Sweden)

    Xiao Yang

    2016-07-01

    Full Text Available The recovery of vanadium from a typical low-grade refractory stone coal was investigated using a pyro-hydrometallurgical process specifically including blank roasting, acid leaching, solvent extraction, and chemical precipitation. The appropriate role of parameters in each process was analyzed in detail. Roasting temperature and roasting time during the roasting process showed a significant effect on leaching efficiency of vanadium. Using H2SO4 as a leaching agent, vanadium leaching efficiency can achieve above 90% under the optimum leaching conditions of CaF2 dosage of 5%, sulfuric acid concentration of 4 mol/L, liquid to solid ratio of 2:1 mL/g, leaching time of 2 h, and leaching temperature of 95 °C. 99.10% of vanadium can be extracted from the leaching solution in three stages under the conditions of initial pH of 1.6, trioctylamine (TOA extractant concentration of 20% (vol, phase ratio (A/O of 2, and reaction time of 2 min. 1.0 mol/L NaOH was used to strip vanadium from the extracted solvent phase. After purification and precipitation, vanadium can be crystallized as ammonium metavanadate. The V2O5 product with a purity of 99.75% is obtained after ammonium metavanadate thermal decomposition at 550 °C for 2 h. The total vanadium recovery in the whole process is above 88%. This process has advantages of short operation time, high vanadium extraction efficiency, and high purity of the product.

  2. Large-scale purification of high purity α1-antitrypsin from Cohn Fraction IV with virus inactivation by solvent/detergent and dry-heat treatment.

    Science.gov (United States)

    Huangfu, Chaoji; Zhang, Jinchao; Ma, Yuyuan; Jia, Junting; Li, Jingxuan; Lv, Maomin; Ma, Xiaowei; Zhao, Xiong; Zhang, Jingang

    2017-10-26

    α1-Antitrypsin (AAT) is widely used to treat patients with congenital AAT deficiency. Cohn Fraction IV (Cohn F IV) is normally discarded during the manufacturing process of albumin but contains approximately 33% of plasma AAT. We established a new process for large-scale purification of AAT from it. liquid chromatography-electrospray ionization-tandem mass spectrometry and high-performance liquid chromatography were applied for qualitative identification and composition analysis, respectively. Stabilizers were optimized for AAT activity protection during lyophilization and dry-heat. Virus inactivation by dry-heat and solvent/detergent (S/D) was validated on a range of viruses. AAT with purity of 95.54%, specific activity of 3,938.5 IU/mg, and yield of 26.79%, was achieved. More than 95% activity was reserved after S/D. More than 96% activity was obtained after lyophilization or dry-heat. After S/D, pseudorabies virus (PRV) and vesicular stomatitis virus (VSV) were inactivated below detectable level within 1 H. Virus titer reductions of more than 5.50 log 10 and 5.38 log 10 were achieved for PRV and VSV, respectively. Porcine parvovirus and encephalomyocarditis virus were inactivated by 3.17 log 10 and 5.88 log 10 reduction after dry-heat. The advantages of this process, including suitability for large-scale production, high purity, better utilization of human plasma, viral safety, commercial and inexpensive chromatography medium, may facilitate its further application. © 2017 International Union of Biochemistry and Molecular Biology, Inc.

  3. Enhanced Crystalline Phase Purity of CH3NH3PbI3-xClx Film for High-Efficiency Hysteresis-Free Perovskite Solar Cells.

    Science.gov (United States)

    Yang, Yingguo; Feng, Shanglei; Xu, Weidong; Li, Meng; Li, Li; Zhang, Xingmin; Ji, Gengwu; Zhang, Xiaonan; Wang, Zhaokui; Xiong, Yimin; Cao, Liang; Sun, Baoquan; Gao, Xingyu

    2017-07-12

    Despite rapid successful developments toward promising perovskite solar cells (PSCs) efficiency, they often suffer significant hysteresis effects. Using synchrotron-based grazing incidence X-ray diffraction (GIXRD) with different probing depths by varying the incident angle, we found that the perovskite films consist of dual phases with a parent phase dominant in the interior and a child phase with a smaller (110) interplanar space (d(110)) after rapid thermal annealing (RTA), which is a widely used post treatment to improve the crystallization of solution-processed perovskite films for high-performance planar PSCs. In particular, the child phase composition gradually increases with decreasing depth till it becomes the majority on the surface, which might be one of the key factors related to hysteresis in fabricated PSCs. We further improve the crystalline phase purity of the solution-processed CH3NH3PbI3-xClx perovskite film (referred as g-perovskite) by using a facile gradient thermal annealing (GTA), which shows a uniformly distributed phase structure in pinhole-free morphology with less undercoordinated Pb and I ions determined by synchrotron-based GIXRD, grazing incidence small-angle X-ray scattering, scanning electron microscopy, and X-ray photoelectron spectroscopy. Regardless of device structures (conventional and inverted types), the planar heterojunction PSCs employing CH3NH3PbI3-xClx g-perovskite films exhibit negligible hysteresis with a champion power conversion efficiency of 17.04% for TiO2-based conventional planar PSCs and 14.83% for poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate) (PEDOT:PSS)-based inverted planar PSCs. Our results indicate that the crystalline phase purity in CH3NH3PbI3-xClx perovskite film, especially in the surface region, plays a crucial role in determining the hysteresis effect and device performance.

  4. Highly efficient 2  μm CW and Q-switched Tm3+:Lu2O3 ceramics lasers in-band pumped by a Raman-shifted erbium fiber laser at 1670  nm.

    Science.gov (United States)

    Antipov, Oleg; Novikov, Anton; Larin, Sergey; Obronov, Ivan

    2016-05-15

    Highly efficient laser oscillations at 2 μm were investigated in Tm:Lu2O3 ceramics in-band pumped at 1670 nm by a Raman-shifted erbium fiber laser. Both 23 W CW and 15 W active Q-switched oscillations with 40 ns pulse duration and 15-30 kHz repetition rate were achieved in a high-quality beam. The evolution of two generated waves at 1966 and 2064 nm in dependence on pump power was studied.

  5. Trace amounts of rare earth elements in high purity samarium oxide by sector field inductively coupled plasma mass spectrometry after separation by HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Pedreira, W.R. [Instituto de Geociencias, Universidade de Brasilia (UnB), 70910-900 Brasilia, DF (Brazil) and Fundacao Jorge Duprat Figueiredo de Seguranca e Medicina do Trabalho (FUNDACENTRO), 05409-002 Sao Paulo, SP (Brazil)]. E-mail: walter.pedreira@fundacentro.gov.br; Queiroz, C.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), 05508-900 Sao Paulo, SP (Brazil); Abrao, A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), 05508-900 Sao Paulo, SP (Brazil); Rocha, S.M. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), 05508-900 Sao Paulo, SP (Brazil); Vasconcellos, M.E. de [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), 05508-900 Sao Paulo, SP (Brazil); Boaventura, G.R. [Instituto de Geociencias, Universidade de Brasilia (UnB), 70910-900 Brasilia, DF (Brazil); Pimentel, M.M. [Instituto de Geociencias, Universidade de Brasilia (UnB), 70910-900 Brasilia, DF (Brazil)

    2006-07-20

    Today there is an increasing need for high purity rare earth compounds in various fields, the optical, the electronics, the ceramic, the nuclear and geochemistry. Samarium oxide has special uses in glass, phosphors, lasers and thermoelectric devices. Calcium chloride crystals treated with samarium have been employed in lasers, which produce light beams intense enough to burn metal. In general, the inductively coupled plasma mass spectrometry (ICP-MS) presents some advantages for trace element analysis, due to high sensitivity and resolution, when compared with other analytical techniques such as ICP optical emission spectrometry (ICP-OES). In this work, sector field inductively coupled plasma mass spectrometry was used. Sixteen elements (Sc, Y and 14 lanthanides) were determined selectively with the ICP-MS system using a concentration gradient method. The detection limits with the ICP-MS system were about 0.2 (La) pg mL{sup -1} to 8 (Gd) pg mL{sup -1}. The %R.S.D. of the methods varying between 0.9 and 1.5% for a set of five (n = 5) replicates was found for the IPEN's material and for the certificate reference sample. Determination of trace REEs in two high pure samarium oxides samples (IPEN and JMC) was performed. IPEN's material is highly pure (>99.99%) and was successfully analyzed without spectral interference (MO{sup +} and MOH{sup +})

  6. Major Role of NAD-Dependent Lactate Dehydrogenases in the Production of l-Lactic Acid with High Optical Purity by the Thermophile Bacillus coagulans.

    Science.gov (United States)

    Wang, Limin; Cai, Yumeng; Zhu, Lingfeng; Guo, Honglian; Yu, Bo

    2014-12-01

    Bacillus coagulans 2-6 is an excellent producer of optically pure l-lactic acid. However, little is known about the mechanism of synthesis of the highly optically pure l-lactic acid produced by this strain. Three enzymes responsible for lactic acid production-NAD-dependent l-lactate dehydrogenase (l-nLDH; encoded by ldhL), NAD-dependent d-lactate dehydrogenase (d-nLDH; encoded by ldhD), and glycolate oxidase (GOX)-were systematically investigated in order to study the relationship between these enzymes and the optical purity of lactic acid. Lactobacillus delbrueckii subsp. bulgaricus DSM 20081 (a d-lactic acid producer) and Lactobacillus plantarum subsp. plantarum DSM 20174 (a dl-lactic acid producer) were also examined in this study as comparative strains, in addition to B. coagulans. The specific activities of key enzymes for lactic acid production in the three strains were characterized in vivo and in vitro, and the levels of transcription of the ldhL, ldhD, and GOX genes during fermentation were also analyzed. The catalytic activities of l-nLDH and d-nLDH were different in l-, d-, and dl-lactic acid producers. Only l-nLDH activity was detected in B. coagulans 2-6 under native conditions, and the level of transcription of ldhL in B. coagulans 2-6 was much higher than that of ldhD or the GOX gene at all growth phases. However, for the two Lactobacillus strains used in this study, ldhD transcription levels were higher than those of ldhL. The high catalytic efficiency of l-nLDH toward pyruvate and the high transcription ratios of ldhL to ldhD and ldhL to the GOX gene provide the key explanations for the high optical purity of l-lactic acid produced by B. coagulans 2-6. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  7. Discrete dynamics on noncommutative CW complexes

    Directory of Open Access Journals (Sweden)

    Vida Milani

    2013-09-01

    Full Text Available The concept of discrete multivalued dynamical systems for noncommutative CW complexes is developed. Stable and unstable manifolds are introduced and their role in geometric and topological configurations of noncommutative CW complexes is studied. Our technique is illustrated by an example on the noncommutative CW complex decomposition of the algebra of continuous functions on two dimensional torus.

  8. Synthesis of high-purity precipitated calcium carbonate during the process of recovery of elemental sulphur from gypsum waste.

    Science.gov (United States)

    de Beer, M; Doucet, F J; Maree, J P; Liebenberg, L

    2015-12-01

    We recently showed that the production of elemental sulphur and calcium carbonate (CaCO3) from gypsum waste by thermally reducing the waste into calcium sulphide (CaS) followed by its direct aqueous carbonation yielded low-grade carbonate products (i.e. carbonation process for the production of high-grade CaCO3 (i.e. >99 mass% as CaCO3) or precipitated calcium carbonate (PCC). The process used an acid gas (H2S) to improve the aqueous dissolution of CaS, which is otherwise poorly soluble. The carbonate product was primarily calcite (99.5%) with traces of quartz (0.5%). Calcite was the only CaCO3 polymorph obtained; no vaterite or aragonite was detected. The product was made up of micron-size particles, which were further characterised by XRD, TGA, SEM, BET and true density. Results showed that about 0.37 ton of high-grade PCC can be produced from 1.0 ton of gypsum waste, and generates about 0.19 ton of residue, a reduction of 80% from original waste gypsum mass to mass of residue that needs to be discarded off. The use of gypsum waste as primary material in replacement of mined limestone for the production of PPC could alleviate waste disposal problems, along with converting significant volumes of waste materials into marketable commodities. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Wet chemical treatments of high purity Ge crystals for γ-ray detectors: Surface structure, passivation capabilities and air stability

    Energy Technology Data Exchange (ETDEWEB)

    Carturan, S., E-mail: carturan@lnl.infn.it [Department of Physics and Astronomy, University of Padova, Padova (Italy); INFN, Laboratori Nazionali di Legnaro, Legnaro, Padova (Italy); Maggioni, G. [Department of Physics and Astronomy, University of Padova, Padova (Italy); INFN, Laboratori Nazionali di Legnaro, Legnaro, Padova (Italy); Rezvani, S.J. [Department of Physics, University of Camerino, Camerino, Macerata (Italy); Gunnella, R. [Department of Physics, University of Camerino, Camerino, Macerata (Italy); INFN, Laboratori Nazionali di Frascati, Frascati (Italy); Pinto, N. [Department of Physics, University of Camerino, Camerino, Macerata (Italy); INFN, Sezione di Perugia, Perugia (Italy); Gelain, M. [Department of Physics and Astronomy, University of Padova, Padova (Italy); INFN, Laboratori Nazionali di Legnaro, Legnaro, Padova (Italy); Napoli, D.R. [INFN, Laboratori Nazionali di Legnaro, Legnaro, Padova (Italy)

    2015-07-01

    Aiming at the production of HPGe diodes for γ-ray detection, surface passivation of the pristine Germanium surface is pursued by treatment of freshly etched, highly reactive Ge (100) surface by different chemicals, to obtain chemisorbed species with sufficient insulating properties for allowing high voltage application (up to 1100 V) with low leakage currents (lower than 30 pA). (100) surface termination of Ge crystal with hydride, methoxide, and sulphide is carried out by wet chemical treatments using suitable reactants. The chemical composition of the newly formed monolayers is investigated with regards to the nature of chemical bonding with Ge atop atoms. To this aim Fourier Transform Infrared Spectrometry (FTIR) and X-ray Photoelectron Spectroscopy (XPS) were used; the performance as dielectric layer of each native Ge compound/complex is measured directly from I–V measurements of a HPGe diode. Atomic stability of each surface layer is monitored detecting structural changes after air exposure by XPS and FTIR spectroscopies and by relevant leakage current variations. - Highlights: • Different surface passivations were applied to HPGe by wet chemical methods. • New chemical bonds were characterized by FTIR and XPS. • Air stability: hydride and sulphide treatments display the best oxidation resistance. • I–V measurements: all the treatments provided efficient passivation.

  10. Trace Element Compositions and Defect Structures of High-Purity Quartz from the Southern Ural Region, Russia

    Directory of Open Access Journals (Sweden)

    Jens Götze

    2017-10-01

    Full Text Available Quartz samples of different origin from 10 localities in the Southern Ural region, Russia have been investigated to characterize their trace element compositions and defect structures. The analytical combination of cathodoluminescence (CL microscopy and spectroscopy, electron paramagnetic resonance (EPR spectroscopy, and trace-element analysis by inductively coupled plasma mass spectrometry (ICP-MS revealed that almost all investigated quartz samples showed very low concentrations of trace elements (cumulative concentrations of <50 ppm with <30 ppm Al and <10 ppm Ti and low abundances of paramagnetic defects, defining them economically as “high-purity” quartz (HPQ suitable for high-tech applications. EPR and CL data confirmed the low abundances of substitutional Ti and Fe, and showed Al to be the only significant trace element structurally bound in the investigated quartz samples. CL microscopy revealed a heterogeneous distribution of luminescence centres (i.e., luminescence active trace elements such as Al as well as features of deformation and recrystallization. It is suggested that healing of defects due to deformation-related recrystallization and reorganization processes of the quartz lattice during retrograde metamorphism resulted in low concentrations of CL activator and other trace elements or vacancies, and thus are the main driving processes for the formation of HPQ deposits in the investigated area.

  11. Development of a certified reference material for composition of high-purity copper as a transfer standard within GET 176-2013

    Directory of Open Access Journals (Sweden)

    Veniamin M. Zyskin

    2017-01-01

    Full Text Available Introduction. The paper gives information on the development of a certified reference material (CRM for composition of high-purity copper (Cu CRM UNIIM. The CRM is included as the transfer standard into the State primary standard of the mass (molar fraction and mass (molar concentration of the component in liquid and solid substances and materials based on coulometry GET 176-2013.Materials and methods. The CRM represents pieces of oxygen-free copper wire rod, brand KMB, produced according to GOST R 53803-2010, weighing from 0.5 to 1g. The CRM is packed in plastic vials with the capacity of 30 or 50 cm3. The certified characteristic of the CRM is copper mass fraction in copper wire rod, expressed in percentages. The certified value for copper mass fraction was established by the primary method of controlled-potential coulometry using the State primary standard GET 176-2013.Results. The permitted interval of the certified value for copper mass fraction in the CRM is from 99,950 % to 100,000 %. The relative expanded uncertainty (k=2 of the certified value for copper mass fraction does not exceed 0,030 %; the relative standard uncertainty due to inhomogeneity does not exceed 0.010 %; the relative standard uncertainty due to instability does not exceed 0.010 %. The shelf life of the developed CRM is 10 years provided that standard storage conditions are ensured.Discussion and conclusions. The developed CRM is included into the State register of type approved RMs under the number GSO 10800-2016. The CRM of high-purity copper (Cu CRM UNIIM as a transfer standard is intended for reproduction, storage and transfer of the copper mass fraction unit to other reference materials and chemical reagents by the method of comparison using a comparator and by conducting direct measurements. This CRM may also be used:– for verification of measuring instruments (MIs according to the state verification schedule described in GOST R 8.735.0-2014,– for calibration

  12. Catalyst evaluation for high-purity H2 production by sorption-enhanced steam-methane reforming coupled to a Ca/Cu process

    Science.gov (United States)

    Navarro, M. V.; López, J. M.; García, T.; Grasa, G.; Murillo, R.

    2017-09-01

    The operational limits of a commercial nickel-based catalyst under the conditions of a sorption-enhanced steam-methane reforming process coupled to a Ca/Cu chemical loop are investigated for high-purity H2 production in a cyclic operation. The performance of the reforming catalyst is tested by means of a high number of oxidation-reduction-reforming cycles. After 100 oxidation-reduction cycles, this catalyst retains its exceptional reforming activity. The methane conversion values are close to the thermodynamic equilibrium under very demanding conditions: temperature between 500 °C - 700 °C and mass hourly space velocity of 8.8 kgCH4 h-1 kgcat-1. After 200 cycles, the sample shows reduction in its reforming activity in line with a lower dispersion of the Ni species. Sintering of Ni nanocrystals is evidenced during the oxidation-reduction multi-cycles. The performance of the catalyst after 200 oxidation-reduction cycles mixed with a CaO-based CO2 sorbent is studied under optimal conditions calculated for the sorption-enhanced reforming process coupled to a Ca/Cu cycle (temperature of 650 °C, steam/methane ratio of 4, sorbent/catalyst ratio of 4 and space velocity of 0.75 kgCH4 h-1 kgcat-1). Remarkably, an equilibrium value over 92 vol.% H2 concentration is achieved, highlighting this catalyst as a promising candidate for the next steps of the process development.

  13. High purity galacto-oligosaccharides (GOS) enhance specific Bifidobacterium species and their metabolic activity in the mouse gut microbiome

    Science.gov (United States)

    Monteagudo-Mera, A.; Arthur, J.C.; Jobin, C.; Keku, T.; Bruno-Barcena, J.M.; Azcarate-Peril, M.A

    2016-01-01

    Prebiotics are selectively fermented ingredients that result in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon the host health. The aim of this study was to evaluate the influence of a β (1–4) galacto-oligosaccharides formulation consisting of 90% pure GOS (GOS90), on the composition and activity of the mouse gut microbiota. Germ-free mice were colonized with microbiota from four pathogen-free wt 129 mice donors (SPF), and stools were collected during a feeding trial in which GOS90 was delivered orally for 14 days. Pyrosequencing of 16S rDNA amplicons showed that Bifidobacterium and specific Lactobacillus, Bacteroides and Clostridiales were more prevalent in GOS90-fed mice after 14 days, although the prebiotic impact on Bifidobacterium varied among individual mice. Prebiotic feeding also resulted in decreased abundance of Bacteroidales, Helicobacter and Clostridium. High-throughput quantitative PCR showed an increased abundance of Bifidobacterium adolescentis, B. pseudocatenulatum, B. lactis and B. gallicum in the prebiotic-fed mice. Control female mice showed a higher diversity (Phylogenetic Diversity PD = 15.1 ± 3.4 in stools and PD = 13.0 ± 0.6 in intestinal contents) than control males (PD = 7.8 ± 1.6 in stool samples and PD = 9.5 ± 1.0 in intestinal contents). GOS90 did not modify inflammatory biomarkers (IL-6, IL-12, IL-1β, IFN-γ and TNF-α). Decreased butyrate, acetate and lactate concentrations in stools of prebiotic fed mice suggested an increase in colonic absorption and reduced excretion. Overall, our results demonstrate that GOS90 is capable of modulating the intestinal microbiome resulting in expansion of the probiome (autochtonous commensal intestinal bacteria considered to have a beneficial influence on health). PMID:26839072

  14. High purity galacto-oligosaccharides enhance specific Bifidobacterium species and their metabolic activity in the mouse gut microbiome.

    Science.gov (United States)

    Monteagudo-Mera, A; Arthur, J C; Jobin, C; Keku, T; Bruno-Barcena, J M; Azcarate-Peril, M A

    2016-01-01

    Prebiotics are selectively fermented ingredients that result in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon the host health. The aim of this study was to evaluate the influence of a β(1-4)galacto-oligosaccharides (GOS) formulation consisting of 90% pure GOS (GOS90), on the composition and activity of the mouse gut microbiota. Germ-free mice were colonised with microbiota from four pathogen-free wt 129 mice donors (SPF), and stools were collected during a feeding trial in which GOS90 was delivered orally for 14 days. Pyrosequencing of 16S rDNA amplicons showed that Bifidobacterium and specific Lactobacillus, Bacteroides and Clostridiales were more prevalent in GOS90-fed mice after 14 days, although the prebiotic impact on Bifidobacterium varied among individual mice. Prebiotic feeding also resulted in decreased abundance of Bacteroidales, Helicobacter and Clostridium. High-throughput quantitative PCR showed an increased abundance of Bifidobacterium adolescentis, Bifidobacterium pseudocatenulatum, Bifidobacterium lactis and Bifidobacterium gallicum in the prebiotic-fed mice. Control female mice showed a higher diversity (phylogenetic diversity (PD) = 15.1 ± 3.4 in stools and PD = 13.0 ± 0.6 in intestinal contents) than control males (PD = 7.8 ± 1.6 in stool samples and PD = 9.5 ± 1.0 in intestinal contents). GOS90 did not modify inflammatory biomarkers (interleukin (IL)-6, IL-12, IL-1β, interferon gamma and tumour necrosis factor alpha). Decreased butyrate, acetate and lactate concentrations in stools of prebiotic fed mice suggested an increase in colonic absorption and reduced excretion. Overall, our results demonstrate that GOS90 is capable of modulating the intestinal microbiome resulting in expansion of the probiome (autochtonous commensal intestinal bacteria considered to have a beneficial influence on health).

  15. Use of alkali metal salts to prepare high purity single-walled carbon nanotube solutions and thin films

    Science.gov (United States)

    Ashour, Rakan F.

    Single-walled carbon nanotubes (SWCNTs) display interesting electronic and optical properties desired for many advanced thin film applications, such as transparent conductive electrodes or thin-film transistors. Large-scale production of SWCNTs generally results in polydispersed mixtures of nanotube structures. Since SWCNT electronic character (conducting or semiconducting nature) depends on the nanotube structure, application performance is being held back by this inability to discretely control SWCNT synthesis. Although a number of post-production techniques are able to separate SWCNTs based on electronic character, diameter, or chirality, most still suffer from the disadvantage of high costs of materials, equipment, or labor intensity to be relevant for large-scale production. On the other hand, chromatographic separation has emerged as a method that is compatible with large scale separation of metallic and semiconducting SWCNTs. In this work, SWCNTs, in an aqueous surfactant suspension of sodium dodecyl sulfate (SDS), are separated by their electronic character using a gel chromatography process. Metallic SWCNTs (m-SWCNTs) are collected as initial fractions since they show minimum interaction with the gel medium, whereas, semiconducting SWCNTs (sc- SWCNTs) remain adsorbed to the gel. The process of sc-SWCNT retention in the gel is found to be driven by the packing density of SDS around the SWCNTs. Through a series of separation experiments, it is shown that sc-SWCNTs can be eluted from the gel simply by disturbing the configuration of the SDS/SWCNT micellar structure. This is achieved by either introducing a solution containing a co-surfactant, such as sodium cholate (SC), or solutions of alkali metal ionic salts. Analysis of SWCNT suspensions by optical absorption provides insights into the effect of changing the metal ion (M+ = Li+, Na+, and K+) in the eluting solution. Salts with smaller metal ions (e.g. Li+) require higher concentrations to achieve

  16. Genotypic and phenotypic diversity of Ralstonia pickettii and Ralstonia insidiosa isolates from clinical and environmental sources including High-purity Water.

    LENUS (Irish Health Repository)

    Ryan, Michael P

    2011-08-30

    Abstract Background Ralstonia pickettii is a nosocomial infectious agent and a significant industrial contaminant. It has been found in many different environments including clinical situations, soil and industrial High Purity Water. This study compares the phenotypic and genotypic diversity of a selection of strains of Ralstonia collected from a variety of sources. Results Ralstonia isolates (fifty-nine) from clinical, industrial and environmental origins were compared genotypically using i) Species-specific-PCR, ii) PCR and sequencing of the 16S-23S rRNA Interspatial region (ISR) iii) the fliC gene genes, iv) RAPD and BOX-PCR and v) phenotypically using biochemical testing. The species specific-PCR identified fifteen out of fifty-nine designated R. pickettii isolates as actually being the closely related species R. insidiosa. PCR-ribotyping of the 16S-23S rRNA ISR indicated few major differences between the isolates. Analysis of all isolates demonstrated different banding patterns for both the RAPD and BOX primers however these were found not to vary significantly. Conclusions R. pickettii species isolated from wide geographic and environmental sources appear to be reasonably homogenous based on genotypic and phenotypic characteristics. R. insidiosa can at present only be distinguished from R. pickettii using species specific PCR. R. pickettii and R. insidiosa isolates do not differ significantly phenotypically or genotypically based on environmental or geographical origin.

  17. Divacancy-hydrogen complexes in dislocation-free high-purity germanium. [Annealing, Hall effect, steady-state concentration energy dependence

    Energy Technology Data Exchange (ETDEWEB)

    Haller, E.E.; Hubbard, G.S.; Hansen, W.L.; Seeger, A.

    1976-09-01

    A defect center with a single acceptor level at E/sub v/ + 0.08 eV appears in H/sub 2/-grown dislocation-free high-purity germanium. Its concentration changes reversibly upon annealing up to 650 K. By means of Hall-effect and conductivity measurements over a large temperature range the temperature dependence of the steady-state concentration between 450 and 720 K as well as the transients following changes in temperature were determined. The observed acceptor level is attributed to the divacancy-hydrogen complex V/sub 2/H. The complex reacts with hydrogen, dissolved in the Ge lattice or stored in traps, according to V/sub 2/H + H reversible V/sub 2/H/sub 2/. An energy level associated with the divacancy-dihydrogen complex was not observed. These results are in good agreement with the idea that hydrogen in germanium forms a ''very deep donor'' (i.e., the energy level lies inside the valence band).

  18. A method for high purity intestinal epithelial cell culture from adult human and murine tissues for the investigation of innate immune function.

    Science.gov (United States)

    Graves, Christina L; Harden, Scott W; LaPato, Melissa; Nelson, Michael; Amador, Byron; Sorenson, Heather; Frazier, Charles J; Wallet, Shannon M

    2014-12-01

    Intestinal epithelial cells (IECs) serve as an important physiologic barrier between environmental antigens and the host intestinal immune system. Thus, IECs serve as a first line of defense and may act as sentinel cells during inflammatory insults. Despite recent renewed interest in IEC contributions to host immune function, the study of primary IEC has been hindered by lack of a robust culture technique, particularly for small intestinal and adult tissues. Here, a novel adaptation for culture of primary IEC is described for human duodenal organ donor tissue as well as duodenum and colon of adult mice. These epithelial cell cultures display characteristic phenotypes and are of high purity. In addition, the innate immune function of human primary IEC, specifically with regard to Toll-like receptor (TLR) expression and microbial ligand responsiveness, is contrasted with a commonly used intestinal epithelial cell line (HT-29). Specifically, TLR expression at the mRNA level and production of cytokine (IFNγ and TNFα) in response to TLR agonist stimulation is assessed. Differential expression of TLRs as well as innate immune responses to ligand stimulation is observed in human-derived cultures compared to that of HT-29. Thus, use of this adapted method to culture primary epithelial cells from adult human donors and from adult mice will allow for more appropriate studies of IECs as innate immune effectors. Published by Elsevier B.V.

  19. One-pot production of chitin with high purity from lobster shells using choline chloride-malonic acid deep eutectic solvent.

    Science.gov (United States)

    Zhu, Ping; Gu, Zhongji; Hong, Shu; Lian, Hailan

    2017-12-01

    For the first time in this study, chitin was solely extracted from lobster shells through a fast, easy and eco-friendly method using deep eutectic solvents (DESs), consisting of mixtures of choline chloride-thiourea (CCT), choline chloride-urea (CCU), choline chloride-glycerol (CCG) and choline chloride-malonic acid (CCMA). The physiochemical properties of the isolated chitins were compared with those of the chemically prepared one and commercial one from shrimp shells. Results showed that CCT, CCU and CCG DESs had no important effect on the elimination of proteins and minerals, while chitin obtained by CCMA DES showed a high purity. The yield (20.63±3.30%) of chitin isolated by CCMA DES was higher than that (16.53±2.35%) of the chemically prepared chitin. The chitin obtained by CCMA DES could be divided into two parts with different crystallinity (67.2% and 80.6%), which also had different thermal stability. Chitin from lobster shells showed porous structure, which is expected to be used for adsorption materials and tissue engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. First experiments with gasdynamic ion source in CW mode

    Energy Technology Data Exchange (ETDEWEB)

    Skalyga, V., E-mail: skalyga@ipfran.ru; Vodopyanov, A. [Institute of Applied Physics, Russian Academy of Sciences (IAP RAS), 46 Ul‘yanova St., Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University of Nizhny Novgorod (UNN), 23 Gagarina St., Nizhny Novgorod 603950 (Russian Federation); Izotov, I.; Golubev, S. [Institute of Applied Physics, Russian Academy of Sciences (IAP RAS), 46 Ul‘yanova St., Nizhny Novgorod 603950 (Russian Federation); Tarvainen, O. [Department of Physics, University of Jyvaskyla, P.O. Box 35 (YFL), 40500 Jyvaskyla (Finland)

    2016-02-15

    A new type of ECR ion source—a gasdynamic ECR ion source—has been recently developed at the Institute of Applied Physics. The main advantages of such device are extremely high ion beam current with a current density up to 600–700 emA/cm{sup 2} in combination with low emittance, i.e., normalized RMS emittance below 0.1 π mm mrad. Previous investigations were carried out in pulsed operation with 37.5 or 75 GHz gyrotron radiation with power up to 100 kW at SMIS 37 experimental facility. The present work demonstrates the first experience of operating the gasdynamic ECR ion source in CW mode. A test bench of SMIS 24 facility has been developed at IAP RAS. 24 GHz radiation of CW gyrotron was used for plasma heating in a magnetic trap with simple mirror configuration. Initial studies of plasma parameters were performed. Ion beams with pulsed and CW high voltage were successfully extracted from the CW discharge. Obtained experimental results demonstrate that all advantages of the gasdynamic source can be realized also in CW operation.

  1. An efficient hydrophilic interaction liquid chromatographic method for the simultaneous determination of metformin and pioglitazone using high-purity silica column.

    Science.gov (United States)

    Mohamed, Abdel-Maaboud Ismail; Mohamed, Fardous Abdel-Fattah; Ahmed, Sameh; Mohamed, Yahya Abduh Salim

    2015-08-01

    Hydrophilic interaction liquid chromatography (HILIC) provides a feasible approach to effectively separate polar compounds in complex matrices. Herein, a simple, reproducible and efficient HILIC method was developed for the simultaneous determination of pioglitazone. HCl (PIO) and metformin HCl (MET) in rabbit plasma. High-purity silica column was used for rapid and efficient separation of these co-administered drugs. The chromatographic parameters were optimized for best separation. The proposed HILIC system provides high separation efficiency with good peak shape compared to reversed phase (RP) chromatography. Additionally, a simple isocratic elution mode with a mobile phase composed of a mixture of methanol and 10mM phosphate buffer (pH 3.0) (94:6, v/v) was used and the effluent was monitored at 230nm. The method was validated in accordance with the requirements of US-FDA guidelines and was found to behave efficiently for the intended purpose. The correlation coefficient of 0.9992 was obtained in the concentration ranges of 0.5-100μgmL(-1). The limits of detection (S/N=3) and quantification (S/N=10) were 0.16 and 0.5ngmL(-1), respectively. The retention times were 3.4 and 5.0min for PIO and MET, respectively. Plasma levels were successfully determined in rabbit with satisfactory precision and accuracy. In addition, the stability tests in rabbit plasma proved reliable stability under the experimental conditions. The developed HILIC method was applied successfully to study the pharmacokinetic behaviors of the studied analytes in rabbit plasma after a single oral dose containing PIO and MET. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Compact, high-power, high-beam-quality quasi-CW microsecond five-pass zigzag slab 1319  nm amplifier.

    Science.gov (United States)

    Guo, Chuan; Zuo, Junwei; Bian, Qi; Xu, Chang; Zong, Qinshuang; Bo, Yong; Shen, Yu; Zong, Nan; Gao, Hongwei; Lin, Yanyong; Yuan, Lei; Liu, Yang; Cui, Dafu; Peng, Qinjun; Xu, Zuyan

    2017-04-20

    We demonstrate a compact, high-power, quasi-continuous-wave (QCW) end-pumped 1319 nm Nd:YAG slab amplifier laser with good beam quality. The laser is based on a QCW pulse Nd:YAG master oscillator and Nd:YAG slab amplifier with multi-pass zigzag architecture. The amplifier operates at a pulse repetition frequency of 500 Hz and pulse width of ∼105  μs, delivering a maximum output power of 51.5 W under absorbed pump power of 217.8 W and corresponding to an extraction efficiency of 14.2%. The beam quality factor is measured to be Mx2=1.61 and My2=1.81 in the orthogonal directions. To the best of our knowledge, this is the first compact, high-power, high-beam-quality QCW Nd:YAG amplifier at 1319 nm based on a multi-pass zigzag slab structure.

  3. Airborne FM-CW SAR and Integrated Navigation System Data Fusion

    NARCIS (Netherlands)

    Lorga, J.F.M.; Meta, A.; Wit, J.J.M. de; Mulder, J.A.

    2005-01-01

    The combination of compact FM-CW radar technology and high resolution SAR pro- cessing techniques should pave the way for the development of a small and cost e®ective imaging radar with high resolution. However, airborne SAR is a very novel application for FM-CW radars. In order to investigate the

  4. Modified Range-Doppler Processing for FM-CW Synthetic Aperture Radar

    NARCIS (Netherlands)

    Wit, J.J.M. de; Meta, A.; Hoogeboom, P.

    2006-01-01

    The combination of compact frequency-modulated continuous-wave (FM-CW) technology and high-resolution synthetic aperture radar (SAR) processing techniques should pave the way for the development of a lightweight, cost-effective, high-resolution, airborne imaging radar. Regarding FM-CW SAR signal

  5. Neutron Damage in Mechanically-Cooled High-Purity Germanium Detectors for Field-Portable Prompt Gamma Neutron Activation Analysis (PGNAA) Systems

    Energy Technology Data Exchange (ETDEWEB)

    E.H. Seabury; C.J. Wharton; A.J. Caffrey; J.B. McCabe; C. DeW. Van Siclen

    2013-10-01

    Prompt Gamma Neutron Activation (PGNAA) systems require the use of a gamma-ray spectrometer to record the gamma-ray spectrum of an object under test and allow the determination of the object’s composition. Field-portable systems, such as Idaho National Laboratory’s PINS system, have used standard liquid-nitrogen-cooled high-purity germanium (HPGe) detectors to perform this function. These detectors have performed very well in the past, but the requirement of liquid-nitrogen cooling limits their use to areas where liquid nitrogen is readily available or produced on-site. Also, having a relatively large volume of liquid nitrogen close to the detector can impact some assessments, possibly leading to a false detection of explosives or other nitrogen-containing chemical. Use of a mechanically-cooled HPGe detector is therefore very attractive for PGNAA applications where nitrogen detection is critical or where liquid-nitrogen logistics are problematic. Mechanically-cooled HPGe detectors constructed from p-type germanium, such as Ortec’s trans-SPEC, have been commercially available for several years. In order to assess whether these detectors would be suitable for use in a fielded PGNAA system, Idaho National Laboratory (INL) has been performing a number of tests of the resistance of mechanically-cooled HPGe detectors to neutron damage. These detectors have been standard commercially-available p-type HPGe detectors as well as prototype n-type HPGe detectors. These tests compare the performance of these different detector types as a function of crystal temperature and incident neutron fluence on the crystal.

  6. In vitro and in vivo studies on the degradation of high-purity Mg (99.99wt.%) screw with femoral intracondylar fractured rabbit model.

    Science.gov (United States)

    Han, Pei; Cheng, Pengfei; Zhang, Shaoxiang; Zhao, Changli; Ni, Jiahua; Zhang, Yuanzhuang; Zhong, Wanrun; Hou, Peng; Zhang, Xiaonong; Zheng, Yufeng; Chai, Yimin

    2015-09-01

    High-purity magnesium (HP Mg) takes advantage in no alloying toxic elements and slower degradation rate in lack of second phases and micro-galvanic corrosion. In this study, as rolled HP Mg was fabricated into screws and went through in vitro immersion tests, cytotoxicity test and bioactive analysis. The HP Mg screws performed uniform corrosion behavior in vitro, and its extraction promoted cell viability, bone alkaline phosphatase (ALP) activity, and mRNA expression of osteogenic differentiation related gene, i.e. ALP, osteopontin (OPN) and RUNX2 of human bone marrow mesenchymal stem cells (hBMSCs). Then HP Mg screws were implanted in vivo as load-bearing implant to fix bone fracture and subsequently gross observation, range of motion (ROM), X-ray scanning, qualitative micro-computed tomography (μCT) analysis, histological analysis, bending-force test and SEM morphology of retrieved screws were performed respectively at 4, 8, 16 and 24 weeks. As a result, the retrieved HP Mg screws in fixation of rabbit femoral intracondylar fracture showed uniform degradation morphology and enough bending force. However, part of PLLA screws was broken in bolt, although its screw thread was still intact. Good osseointegration was revealed surrounding HP Mg screws and increased bone volume and bone mineral density were detected at fracture gap, indicating the rigid fixation and enhanced fracture healing process provided by HP Mg screws. Consequently, the HP Mg showed great potential as internal fixation devices in intra-articular fracture operation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. New process for purifying high purity α1-antitrypsin from Cohn Fraction IV by chromatography: A promising method for the better utilization of plasma.

    Science.gov (United States)

    Huangfu, Chaoji; Zhang, Jinchao; Ma, Yuyuan; Jia, Junting; Lv, Maomin; Zhao, Xiong; Zhang, Jingang

    2017-03-01

    α1-antitrypsin (AAT) is a 52kDa serine protease inhibitor that is abundant in plasma. It is synthesized mainly by hepatic cells, and widely used to treat patients with emphysema due to congenital deficiency of AAT. A new isolation method for the purification of AAT from Cohn Fraction IV (Cohn F IV) is described. Cohn F IV is usually discarded as a byproduct from Cohn process. Using Cohn F IV as starting material does not interfere with the production of other plasma proteins and the cost of purification could be reduced greatly. Parameters of each step during purification were optimized, 15% polyethyleneglycol (PEG) concentration and pH 5.2 for PEG precipitation, elution with 0.05M sodium acetate and pH 4.7 for ion-exchange chromatography, and two steps blue sepharose affinity chromatography were chosen for AAT purification. The final protein with purity of 98.17%, specific activity of 3893.29 IU/mg, and yield of 28.35%, was achieved. Western blotting was applied for qualitative identification of final product, which specifically reacted with goat anti-human AAT antibody. LC-ESI-MS/MS was also employed to confirm the final protein. High performance liquid chromatography was used to analyze the composition of purified protein suggesting that pure protein was achieved. The molecular weight of AAT is 51062.77Da which was identified by LC-MS-MS. The manufacturing process described here may make better use of human plasma with Cohn F IV as starting material. The simple process described in this study is simple and inexpensive, it has a potential value for large scale production. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Controllable biosynthesis of high-purity lead-sulfide (PbS) nanocrystals by regulating the concentration of polyethylene glycol in microbial system.

    Science.gov (United States)

    Yue, Lei; Wang, Jia; Zhang, Yongtao; Qi, Shiyue; Xin, Baoping

    2016-12-01

    We demonstrated a simple biological method to explore the controllable synthesize of high-purity PbS nanocrystals by regulating the concentration of polyethylene glycol in microbial system. The biogenic H2S produced via the reduction of sulfate precipitated Pb2+ ions as sulfide extracellularly, and the optimal removal rate of Pb2+ ions is up to 96.7 % in 2 weeks. The characterization results showed that PbS nanocuboids with a particle size 50 × 50 × 100 nm obtained from Case A with 4 mM polyethylene glycol as a dispersant, and can completely degrade methylene blue from solution within 20 h; PbS nanosheets with a thickness size ca. 10 nm attained from Case B with 12 mM polyethylene glycol, and it can degrade 61.6 % dye within 24 h; PbS nanoparticles with a uniform diameter of ca. 60 nm formed from Case C with 20 mM polyethylene glycol, only degrade 14.1 % dye within 24 h. It is interesting that the factor affecting their catalytic activities is not the specific surface area, but the number of [200] crystal plane. This work not only displayed a simple synthetic method to control the morphology of PbS nanocrystals in microbial system, but also provided an economic and environmentally friendly approach for resourceful treatment and efficient bioremediation of wastewater-containing heavy metal.

  9. SAR: A novel application for FM-CW radars

    NARCIS (Netherlands)

    Wit, J.J.M. de; Hoogeboom, P.

    2001-01-01

    For small-scale earth observation applications, there ia a special interest in low-cost, high-resolution imaging radars small, enough to be operated from small, possibly unmanned aircraft. The combination of FM-CW technology and the high resolution of SAR systems should result in such a small,

  10. Analysis of the Purity of Cetrimide by Titrations

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Rasmussen, Claus/Dallerup; Nielsen, Hans/Boye

    2006-01-01

    The purity of cetrimide, trimethyl tetradecyl ammonium bromide (TTAB), that is an important preservative of many cosmetic and pharmaceutical products, was determined by three independent methods of titration. Traditionally, cetrimide was analysed by an assay method of the European Pharmacopoeia (Ph....... Eur.), which showed consistently a low purity of cetrimide with large standard deviations associated, however. A systematic 3% bias of the Ph. Eur. assay method was identified by comparing the result with results of two alternative methods of titration that exhibited high precision and high accuracy....... Titration by perchloric acid showed a 99.69 ± 0.05 % purity of cetrimide and titration by silver nitrate showed a 99.85% ± 0.05 % purity while the traditional assay method predicted a purity of only 97.1 ± 0.4. It was found that the discrepancy could be identified as differences in selectivity during...

  11. Electrostatic simulation of a liquid xenon purity monitor

    Science.gov (United States)

    Gdanski, Jared; nEXO Collaboration

    2017-09-01

    Liquid xenon detectors like the proposed nEXO neutrinoless double beta decay experiment use scintillation and ionization signals to track the position and energy of radiation events in the detector. Ionization signals can be diminished by impurities in the xenon. We have designed a liquid xenon purity monitor with high voltage switching capability to measure long electron lifetimes for studying detector materials. We discuss the use of COMSOL electrostatic simulation software to model the field cage of this purity monitor and simulate the electron transport efficiency. An intensive study of the high voltage switching region and shielding grids was completed to ensure uniform electric fields and grid transparencies in the purity monitor.

  12. IOT RF Power Sources for Pulsed and CW Linacs

    CERN Document Server

    Bohlen, H P

    2004-01-01

    For many years, klystrons have been the preferred RF power amplifiers for both pulsed and CW linacs at UHF and higher frequencies. Their properties have earned them that position. But in recent years in UHF terrestrial television transmitters the earlier predominant klystron has been replaced the Inductive Output Tube (IOT) because the IOT provides higher efficiency and, due to its excellent linearity, can handle the simultaneous amplification of both the vision and the sound signal. Its robustness and life expectancy equals that of a klystron, and it more than compensates its lower gain by a lower price and a smaller size. For linac operation, derivates of UHF TV IOTs, capable of up to 80 kW CW output power, are already available and operating. In L-Band, they are presently joined by recently developed 15 to 30 kW CW IOTs. HOM-IOTs are expected to extend the CW range in UHF to 1 MW and beyond. Pulsed operation of an IOT can be achieved without a high-voltage modulator. Since the beam current is grid-controll...

  13. Efeito da porosidade nas propriedades mecânicas de uma alumina de elevada pureza Effect of porosity on mechanical properties of a high purity alumina

    Directory of Open Access Journals (Sweden)

    H. N. Yoshimura

    2005-09-01

    Full Text Available Uma alumina de elevada pureza dopada com MgO foi sinterizada entre 1300 e 1700 °C para preparação de corpos com diferentes porosidades. Foram determinadas a resistência à flexão em quatro pontos, a tenacidade à fratura pelo método SEVNB, a dureza Vickers, as velocidades sônicas (longitudinal e transversal e as constantes elásticas (ni, E, G e K pelo método do pulso-eco ultrassônico. Os resultados foram comparados com os modelos baseados em concentração de tensão (CT e modelos baseados na área sólida mínima (ASM. A porosidade das amostras variou entre 0,8% e 35%. Em geral, as propriedades diminuíram com o aumento da porosidade, sendo que a diminuição foi menos acentuada nas velocidades sônicas e mais acentuada na dureza. O coeficiente de Poisson só diminuiu em porosidade acima de 19%. O modelo analítico (CT que melhor se ajustou aos resultados dos módulos E e G foi o de Hashin-Rosen para configuração de poros cilíndricos alinhados transversalmente à tensão aplicada. A análise pelos modelos de ASM indicou que, até 19% de porosidade, o modelo de poros esféricos em arranjo cúbico foi predominante e, acima desta porosidade, atuou também o modelo de partículas esféricas em arranjo cúbico.A high purity alumina doped with MgO was sintered between 1300 and 1700 °C in order to prepare samples with different porosities. The following properties were determined: four-point flexural strength, fracture toughness, by SEVNB method, Vickers hardness, (transversal and longitudinal sonic velocities, and elastic constant (nu, E, G e K, by ultrasonic pulse-echo method. The results were compared with models based on stress concentration (SC and models based on minimum solid area (MSA. The porosity of the samples varied between 0.8% and 35%. Generally, the properties lowered with increasing porosity. This lowering was weaker in sonic velocities and stronger in hardness. The Poisson's ratio lowered only above 19% porosity. The

  14. A New Route for High-Purity Organic Materials: High-Pressure-Ramp-Induced Ultrafast Polymerization of 2-(Hydroxyethyl)Methacrylate

    Science.gov (United States)

    Evlyukhin, E.; Museur, L.; Traore, M.; Perruchot, C.; Zerr, A.; Kanaev, A.

    2015-12-01

    The synthesis of highly biocompatible polymers is important for modern biotechnologies and medicine. Here, we report a unique process based on a two-step high-pressure ramp (HPR) for the ultrafast and efficient bulk polymerization of 2-(hydroxyethyl)methacrylate (HEMA) at room temperature without photo- and thermal activation or addition of initiator. The HEMA monomers are first activated during the compression step but their reactivity is hindered by the dense glass-like environment. The rapid polymerization occurs in only the second step upon decompression to the liquid state. The conversion yield was found to exceed 90% in the recovered samples. The gel permeation chromatography evidences the overriding role of HEMA2•• biradicals in the polymerization mechanism. The HPR process extends the application field of HP-induced polymerization, beyond the family of crystallized monomers considered up today. It is also an appealing alternative to typical photo- or thermal activation, allowing the efficient synthesis of highly pure organic materials.

  15. The Liquid Argon Purity Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Adamowski, M.; Carls, B.; Dvorak, E.; Hahn, A.; Jaskierny, W.; Johnson, C.; Jostlein, H.; Kendziora, C.; Lockwitz, S.; Pahlka, B.; Plunkett, R.; Pordes, S.; Rebel, B.; Schmitt, R.; Stancari, M.; Tope, T.; Voirin, E.; Yang, T.

    2014-07-01

    The Liquid Argon Purity Demonstrator was an R&D test stand designed to determine if electron drift lifetimes adequate for large neutrino detectors could be achieved without first evacuating the cryostat. We describe here the cryogenic system, its operations, and the apparatus used to determine the contaminant levels in the argon and to measure the electron drift lifetime. The liquid purity obtained by this system was facilitated by a gaseous argon purge. Additionally, gaseous impurities from the ullage were prevented from entering the liquid at the gas-liquid interface by condensing the gas and filtering the resulting liquid before returning to the cryostat. The measured electron drift lifetime in this test was greater than 6 ms, sustained over several periods of many weeks. Measurements of the temperature profile in the argon, to assess convective flow and boiling, were also made and are compared to simulation.

  16. Purity homophily in social networks.

    Science.gov (United States)

    Dehghani, Morteza; Johnson, Kate; Hoover, Joe; Sagi, Eyal; Garten, Justin; Parmar, Niki Jitendra; Vaisey, Stephen; Iliev, Rumen; Graham, Jesse

    2016-03-01

    Does sharing moral values encourage people to connect and form communities? The importance of moral homophily (love of same) has been recognized by social scientists, but the types of moral similarities that drive this phenomenon are still unknown. Using both large-scale, observational social-media analyses and behavioral lab experiments, the authors investigated which types of moral similarities influence tie formations. Analysis of a corpus of over 700,000 tweets revealed that the distance between 2 people in a social-network can be predicted based on differences in the moral purity content-but not other moral content-of their messages. The authors replicated this finding by experimentally manipulating perceived moral difference (Study 2) and similarity (Study 3) in the lab and demonstrating that purity differences play a significant role in social distancing. These results indicate that social network processes reflect moral selection, and both online and offline differences in moral purity concerns are particularly predictive of social distance. This research is an attempt to study morality indirectly using an observational big-data study complemented with 2 confirmatory behavioral experiments carried out using traditional social-psychology methodology. (c) 2016 APA, all rights reserved).

  17. Highly Efficient, Compact, Wavelength Converters for Pulsed and CW Laser Sources Used in Lidar-Based Remote Sensing and Ranging Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — AdvR, Inc. proposes the development of a highly efficient, fiber pigtailed, waveguide-based UV frequency converter module. This UV module will be an important...

  18. Human plasma-derived immunoglobulin G fractionated by an aqueous two-phase system, caprylic acid precipitation, and membrane chromatography has a high purity level and is free of detectable in vitro thrombogenic activity.

    Science.gov (United States)

    Vargas, M; Segura, Á; Wu, Y-W; Herrera, M; Chou, M-L; Villalta, M; León, G; Burnouf, T

    2015-02-01

    Instituto Clodomiro Picado has developed an immunoglobulin G (IgG) plasma fractionation process combining a polyethylene glycol/phosphate aqueous two-phase system (ATPS), caprylic acid precipitation and anion-exchange membrane chromatography. We evaluated the purity and in vitro thrombogenicity of such IgG, in line with current international requirements. Contributions of the different production steps to reduce thrombogenicity were assessed at 0·2 l-scale, and then the methodology was scaled-up to a 10 l-scale and final products (n = 3) were analysed. Purity, immunoglobulin composition, and subclass distribution were determined by electrophoretic and immunochemical methods. The in vitro thrombogenic potential was determined by a thrombin generation assay (TGA) using a Technothrombin fluorogenic substrate. Prekallikrein activator (PKA), plasmin, factor Xa, thrombin and thrombin-like activities were assessed using S-2302, S-2251, S-2222, S-2238 and S-2288 chromogenic substrates, respectively, and FXI by an ELISA. The thrombogenicity markers were reduced mostly during the ATPS step and were found to segregate mostly into the discarded liquid upper phase. The caprylic acid precipitation eliminated the residual procoagulant activity. The IgG preparations made from the 10 l-batches contained 100% gamma proteins, low residual IgA and undetectable IgM. The IgG subclass distribution was not substantially affected by the process. TGA and amidolytic activities revealed an undetectable in vitro thrombogenic risk and the absence of proteolytic enzymes in the final product. Fractionating human plasma by an ATPS combined with caprylic acid and membrane chromatography resulted in an IgG preparation of high purity and free of a detectable in vitro thrombogenic risk. © 2014 International Society of Blood Transfusion.

  19. Two-color CW STED nanoscopy

    Science.gov (United States)

    Chen, Xuanze; Liu, Yujia; Yang, Xusan; Wang, Tingting; Alonas, Eric; Santangelo, Philip J.; Ren, Qiushi; Xi, Peng

    2013-02-01

    Fluorescent microscopy has become an essential tool to study biological molecules, pathways and events in living cells, tissues and animals. Meanwhile even the most advanced confocal microscopy can only yield optical resolution approaching Abbe diffraction limit of 200 nm. This is still larger than many subcellular structures, which are too small to be resolved in detail. These limitations have driven the development of super-resolution optical imaging methodologies over the past decade. In stimulated emission depletion (STED) microscopy, the excitation focus is overlapped by an intense doughnut-shaped spot to instantly de-excite markers from their fluorescent state to the ground state by stimulated emission. This effectively eliminates the periphery of the Point Spread Function (PSF), resulting in a narrower focal region, or super-resolution. Scanning a sharpened spot through the specimen renders images with sub-diffraction resolution. Multi-color STED imaging can present important structural and functional information for protein-protein interaction. In this work, we presented a two-color, synchronization-free STED microscopy with a Ti:Sapphire oscillator. The excitation wavelengths were 532nm and 635nm, respectively. With pump power of 4.6 W and sample irradiance of 310 mW, we achieved super-resolution as high as 71 nm. Human respiratory syncytial virus (hRSV) proteins were imaged with our two-color CW STED for co-localization analysis.

  20. LOT-G3: Plasma Lamp, Ozonator and CW transmitter

    CERN Document Server

    Gobato, Ricardo; Gobato, Alekssander

    2015-01-01

    The LOT-G3 is designed to be a versatile equipment that perform several simple experiments for use in helping the physics classes for high school. Easy construction, low cost, using easily accessible materials. Its construction involves simple practices and knowledge of electromagnetism. It has the function of a plasma globe to demonstrate the ionization of a low pressure gas, as well as the formation of magnetic field. Can be used as sanitizer closed environments such as automotive vehicles in ozonator function, demonstrating the ionization of oxygen in the atmosphere, producing ozone, essential to life on earth. And as a sparks transmitter, low power, low frequency modulated continuous wave in (CW), for signals in Morse code. Therefore the equipment here called LOT-G3, has three functions: a plasma lamp, ozonator and CW transmitter.

  1. CW-to-pulse conversion using temporal Talbot array illuminators.

    Science.gov (United States)

    Fernández-Pousa, Carlos R; Maram, Reza; Azaña, José

    2017-07-01

    We report on the linear conversion of continuous-wave (CW) laser light to optical pulses using temporal Talbot array illuminators (TAIs) with fractional orders 1/q(q≤10), implemented by use of multilevel PM and dispersive propagation in a chirped fiber Bragg grating. The generated, sub-nanosecond optical pulse trains have repetition rates in the gigahertz range and show the presence of satellite pulses originated by the finite electrical modulation bandwidth (7.5 GHz). Though this fact impacts the resulting extinction ratio, an experimental comparison with time and Fresnel lenses indicates that temporal TAIs represent compact systems with high light gathering efficiency (>87%) at moderate values of compression (q≤8), which can be tailored in repetition rate, gain, or width, through the fractional Talbot order for its use in pulse compression systems fed by CW light.

  2. CW CO2 Laser Induced Chemical Reactions

    Science.gov (United States)

    Pola, Joseph

    1989-05-01

    CW CO2 laser driven reactions between sulfur hexafluoride and carbon oxide, carbon suboxide, carbonyl sulfide and carbon disulfide proceed at subatmospheric pressures and yield fluorinated carbon compounds and sulfur tetrafluoride. CW CO2 laser driven reactions of organic compounds in the presence of energy-conveying sulfur hexafluoride show reaction course different from that normally observed due to elimination of reactor hot surface effects. The examples concern the decomposition of polychlorohydrocarbons, 2-nitropropane, tert.-butylamine, allyl chloride, spirohexane, isobornyl acetate and the oxidation of haloolefins. CW CO2 laser induced fragmentation of 1-methyl-l-silacyclobutanes and 4-silaspiro(3.4)octane in the presence of sulfur hexafluoride is an effective way for preparation and deposition of stable organosilicon polymers.

  3. Ways for accurate analysis of high purity materials using the glow discharge mass spectrometry (GD-MS); Wege zur genauen Charakterisierung hochreiner Materialien mit der Glimmentladungs-Massenspektrometrie (GD-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Gusarova, Tamara

    2010-04-14

    The main aim of this work consists in the investigation, development and application of improved possibilities of accurate analysis of high purity materials using the solid sample technique of Glow Discharge Mass Spectrometry (GD-MS), as well as in the sensitivity enhancement of GD Optical Emission Spectrometry (GD-OES) by implicating the hollow cathode effect. The emphasis of the PhD thesis consists in the accurate quantification for GD-MS. As appropriate certified reference materials (CRMs) for calibration are lacking in most cases an accurate quantification especially for trace elements mass fractions at {mu}g kg{sup -1} level can often not be achieved. To overcome this problem and to expand the possibilities of modern GD-MS hereby, synthetic standards were applied for calibration of both high resolution GD-MS instruments ''VG 9000'' and ''Element GD''. The standards were prepared by doping of matrix powder with trace element standard solutions followed by drying and pressing the doped powder to compact pellets. With the quantification approach worked out and described here accurate analysis results with small uncertainties can be achieved for most elements of periodic table in almost every matrix composition. Furthermore direct traceability of the analytical results to the International System of Units (SI) is provided ensuring their higher metrological quality. Numerous additional systematic investigations concerning the preparation of the synthetic standards and their properties were carried out. The results of calibration of GD-MS instruments with synthetic standards for Co (Co-C), Cu, In, Fe and Zn matrices were checked by measuring CRMs. These results were also contrasted with those of other quantification approaches, as usually used in GD-MS routine. The results achieved with synthetic standards had the highest accuracy. The successful participation in the round robin test CCQM-P107 between international

  4. A Variable Energy CW Compact Accelerator for Ion Cancer Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, Carol J. [Fermilab; Taylor, J. [Huddersfield U.; Edgecock, R. [Huddersfield U.; Schulte, R. [Loma Linda U.

    2016-03-10

    Cancer is the second-largest cause of death in the U.S. and approximately two-thirds of all cancer patients will receive radiation therapy with the majority of the radiation treatments performed using x-rays produced by electron linacs. Charged particle beam radiation therapy, both protons and light ions, however, offers advantageous physical-dose distributions over conventional photon radiotherapy, and, for particles heavier than protons, a significant biological advantage. Despite recognition of potential advantages, there is almost no research activity in this field in the U.S. due to the lack of clinical accelerator facilities offering light ion therapy in the States. In January, 2013, a joint DOE/NCI workshop was convened to address the challenges of light ion therapy [1], inviting more than 60 experts from diverse fields related to radiation therapy. This paper reports on the conclusions of the workshop, then translates the clinical requirements into accelerat or and beam-delivery technical specifications. A comparison of available or feasible accelerator technologies is compared, including a new concept for a compact, CW, and variable energy light ion accelerator currently under development. This new light ion accelerator is based on advances in nonscaling Fixed-Field Alternating gradient (FFAG) accelerator design. The new design concepts combine isochronous orbits with long (up to 4m) straight sections in a compact racetrack format allowing inner circulating orbits to be energy selected for low-loss, CW extraction, effectively eliminating the high-loss energy degrader in conventional CW cyclotron designs.

  5. Iodine Absorption Cells Purity Testing

    Directory of Open Access Journals (Sweden)

    Jan Hrabina

    2017-01-01

    Full Text Available This article deals with the evaluation of the chemical purity of iodine-filled absorption cells and the optical frequency references used for the frequency locking of laser standards. We summarize the recent trends and progress in absorption cell technology and we focus on methods for iodine cell purity testing. We compare two independent experimental systems based on the laser-induced fluorescence method, showing an improvement of measurement uncertainty by introducing a compensation system reducing unwanted influences. We show the advantages of this technique, which is relatively simple and does not require extensive hardware equipment. As an alternative to the traditionally used methods we propose an approach of hyperfine transitions’ spectral linewidth measurement. The key characteristic of this method is demonstrated on a set of testing iodine cells. The relationship between laser-induced fluorescence and transition linewidth methods will be presented as well as a summary of the advantages and disadvantages of the proposed technique (in comparison with traditional measurement approaches.

  6. Study of the recrystallization mechanisms of ultra-high purity iron doped with carbon, manganese and phosphorus; Etude des mecanismes de recristallisation dans le fer de ultra-haute purete dope en carbone, manganese et phosphore

    Energy Technology Data Exchange (ETDEWEB)

    Lesne, L.

    2000-07-04

    High purity steels have the potential to improve deep drawing properties for automotive applications. Understanding the influence of the chemical composition on the recrystallization mechanisms and on texture development should help to improve their properties. We have studied the influence of 10 ppm of carbon, 1000 ppm of manganese and 120 ppm of phosphorus on the recrystallization mechanisms of ultra-high purity iron (UHP iron > 99.997%). For this purpose we used 4 materials: one undoped (UHP), one doped with C, one doped with C, Mn and one doped With C, Mn, P. In order to restrict grain coarsening in the hot strips, hot rolling was performed in the ferritic region, in one pass of 80% thickness reduction. The hot bands were then fully recrystallized but exhibited non-isotropic textures, with in particular an intense Goss [110]<001> component for the doped materials. The hot-bands were subsequently cold rolled down to a thickness of 0.8 mm corresponding to a thickness reduction of 80%, and then continuously annealed at 10 deg. C/s. The recrystallization kinetics are delayed with the addition of doping elements. In particular, the incubation time for nucleation is shifted towards higher temperatures while the recrystallization velocity increases. The textures of the fully recrystallized materials exhibit a strong Goss component prejudicial for deep drawing properties. We have established that this component can only appear if coarse grains and carbon in solid solution were simultaneously present in the material before deformation. Characterisation of the cold deformed state enabled us to evaluate the energy stored during deformation as a function of the material composition and the grain orientation: - the overall stored energy increases with the doping elements content. - the stored energy in the {gamma} fibre grains is greater than in the {alpha} fibre grains: 30 J/mol for the {gamma} fibre instead of 5 J/mol for the {alpha} fibre, in the undoped UHP iron. In the

  7. Realization of the low background neutrino detector Double Chooz. From the development of a high-purity liquid and gas handling concept to first neutrino data

    Energy Technology Data Exchange (ETDEWEB)

    Pfahler, Patrick

    2012-12-17

    Neutrino physics is one of the most vivid fields in particle physics. Within this field, neutrino oscillations are of special interest as they allow to determine driving oscillation parameters, which are collected as mixing angles in the leptonic mixing matrix. The exact knowledge of these parameters is the main key for the investigation of new physics beyond the currently known Standard Model of particle physics. The Double Chooz experiment is one of three reactor disappearance experiments currently taking data, which recently succeeded to discover a non-zero value for the last neutrino mixing angle {Theta}{sub 13}. As successor of the CHOOZ experiment, Double Chooz will use two detectors with improved design, each of them now composed of four concentrically nested detector vessels each filled with different detector liquid. The integrity of this multi-layered structure and the quality of the used detector liquids are essential for the success of the experiment. Within this frame, the here presented work describes the production of two detector liquids, the filling and handling of the Double Chooz far detector and the installation of all necessary hardware components therefore. In order to meet the strict requirements existing for the detector liquids, all components were individually selected in an extensive material selection process at TUM, which compared samples from different companies for their key properties: density, transparency, light yield and radio purity. Based on these measurements, the composition of muon veto scintillator and buffer liquid were determined. For the production of the detector liquids, a simple surface building close to the far detector site was upgraded into a large-scale storage and mixing facility, which allowed to separately, mix, handle and store 90 m{sup 3} of muon veto scintillator and 110 m{sup 3} of buffer liquid. For the muon veto scintillator, a master-solution composed of 4800 l LAB, 180 kg PPO and 1.8 kg of bis/MSB was

  8. Causal Pixel Purity Index (PPI)

    Science.gov (United States)

    Wu, Chao-Cheng; Chang, Chein-I.

    2009-05-01

    Pixel Purity Index (PPI) has been widely used in endmember extraction. While it is available in ENVI software there are several interesting issues arising in its implementation. This paper re-invents the wheel by re-visiting the design rationale of the PPI and re-designing algorithms to implement PPI. More specifically, it develops the so-called Causal PPI (CPPI) which implements the PPI in a causal manner in the sense that the information used for data processing is only up to the data sample currently being visited. If the time required for computer processing is negligible, the CPPI actually becomes a real time PPI. The proposed CPPI can be implemented automatically and resolves the main issue of requiring human intervention to determine parameters.

  9. Simulation for photon detection in spectrometric system of high purity (HPGe) using MCNPX code; Simulacao de deteccao de fotons em sistema espectrometrico de alta pureza (HPGe) usando o codigo MCNPX

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Guilherme Jorge de Souza

    2013-07-01

    The Brazilian National Commission of Nuclear Energy defines parameters for classification and management of radioactive waste in accordance with the activity of materials. The efficiency of a detection system is crucial to determine the real activity of a radioactive source. When it's possible, the system's calibration should be performed using a standard source. Unfortunately, there are only a few cases that it can be done this way, considering the difficulty of obtaining appropriate standard sources for each type of measurement. So, computer simulations can be performed to assist in calculating of the efficiency of the system and, consequently, also auxiliary the classification of radioactive waste. This study aims to model a high purity germanium (HPGe) detector with MCNPX code, approaching the spectral values computationally obtained of the values experimentally obtained for the photopeak of {sup 137}Cs. The approach will be made through changes in outer dead layer of the germanium crystal modeled. (author)

  10. On line chemical analyzers for high purity steam and water, applied to steam power plants; Analizadores quimicos en linea para agua y vapor de alta pureza, aplicados a centrales termoelectricas

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Perez, Ruth [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1989-12-31

    This article presents a general overview of the advances in the subject of on line analyzers of chemical parameters for high purity water and steam and specifies which ones are commercially available. Also are mentioned besides, the criteria nowadays applied for the selection of the sites for sample grabbing and the analysis that is necessary to perform in each point, depending on the power plant type and the treatment administered (phosphates-Ph coordinated or AVT treatment). [Espanol] El articulo presenta un panorama general de los avances que en materia de analizadores de parametros quimicos en linea para agua y vapor de alta pureza, y especifica cuales estan disponibles en forma comercial. Se citan, ademas los criterios que se aplican actualmente para seleccionar los puntos de toma de muestra y los analisis que es necesario efectuar en cada punto, dependiendo del tipo de central y del tratamiento que se le administre (fosfatos-pH coordinado o tratamiento AVT).

  11. Measurements of gamma (γ)-emitting radionuclides with a high-purity germanium detector: the methods and reliability of our environmental assessments on the Fukushima 1 Nuclear Power Plant accident.

    Science.gov (United States)

    Mimura, Tetsuro; Mimura, Mari; Komiyama, Chiyo; Miyamoto, Masaaki; Kitamura, Akira

    2014-01-01

    The severe accident of Fukushima 1 Nuclear Power Plant due to the Tohoku Region Pacific Coast Earthquake in 11 March 2011 caused wide contamination and pollution by radionuclides in Fukushima and surrounding prefectures. In the current JPR symposium, a group of plant scientists attempted to examine the impact of the radioactive contamination on wild and cultivated plants. Measurements of gamma (γ) radiation from radionuclides in "Fukushima samples", which we called and collected from natural and agricultural areas in Fukushima prefecture were mostly done with a high-purity Ge detector in the Graduate School of Maritime Sciences, Kobe University. In this technical note, we describe the methods of sample preparation and measurements of radioactivity of the samples and discuss the reliability of our data in regards to the International Atomic Energy Agency (IAEA) Interlaboratory comparisons and proficiency test (IAEA proficiency test).

  12. Cross-spectral purity of electromagnetic fields.

    Science.gov (United States)

    Hassinen, Timo; Tervo, Jani; Friberg, Ari T

    2009-12-15

    We extend Mandel's scalar-wave concept of cross-spectral purity to electromagnetic fields. We show that in the electromagnetic case, assumptions similar to the scalar cross-spectral purity lead to a reduction formula, analogous with the one introduced by Mandel. We also derive a condition that shows that the absolute value of the normalized zeroth two-point Stokes parameter of two cross-spectrally pure electromagnetic fields is the same for every frequency component of the field. In analogy with the scalar theory we further introduce a measure of the cross-spectral purity of two electromagnetic fields, namely, the degree of electromagnetic cross-spectral purity.

  13. Wildevoelvlei/Noordhoek (CW28)

    CSIR Research Space (South Africa)

    Heinecken, TJE

    1985-08-01

    Full Text Available . Furthermore because of the inter-relationship between a high water table and the vleis and pans in the Noordehoek and Kommetjie basin, the two Wildevoelvlei cannot be considered in isolation from the other water bodies in the basin. Although, there does...

  14. Bandwidth reduction in CW fiber Raman lasers

    Science.gov (United States)

    Labudde, P.; Weber, H. P.; Stolen, R. H.

    1980-02-01

    The oscillation linewidth of CW fiber Raman lasers has been reduced from typical uncontrolled values of 200 GHz (approximately 0.2 nm for 528 nm radiation) to 9 GHz by employing prisms, gratings, and etalons in various resonator configurations. Further reduction is limited by four-wave mixing and stimulated Brillouin scattering. Although four-wave mixing limits bandwidth reduction, the results demonstrate the use of this nonlinear process for intensity stabilization.

  15. The Jewishness of Jesus and ritual purity

    Directory of Open Access Journals (Sweden)

    Cecilia Wassen

    2016-01-01

    Full Text Available Today it is commonplace for historical Jesus scholars to emphasize Jesus’ Jewishness. At the same time most New Testament scholars deny that he cared about the Jewish purity system, which was a central aspect of early Judaism. This article examines how such a reconstruction of the historical Jesus would influence his Jewishness, arguing that it indeed would make such a Jesus figure ‘less Jewish’. The article also investigates questions concerning what Jewish identity in the late Second Temple period entails and how we may characterize the Judaism of Jesus’ time, especially in relation to purity concerns. Finally, I examine key Gospel texts that are commonly used as evidence to prove Jesus’ alleged disinterest in purity laws. On the basis of a proper understanding of how the purity system functioned in Jesus’ time, I conclude that there is no evidence for the view that Jesus was disinterested in matters of purity; quite the opposite.

  16. An experimental study on quasi-CW fibre laser drilling of nickel superalloy

    Science.gov (United States)

    Marimuthu, S.; Antar, M.; Dunleavey, J.; Chantzis, D.; Darlington, W.; Hayward, P.

    2017-09-01

    Laser drilling of metals and alloys is extensively used in modern manufacturing industries to produce holes of various size and shape. Currently, most laser drilling of aerospace nickel superalloys is performed using Nd:YAG laser. Over the years, many attempts were made to increase the productivity of Nd:YAG lasers drilling process, but with little success. This paper investigates the fundamental aspects of millisecond-pulsed-Quasi-CW-fibre laser drilling of aerospace nickel superalloy. The main investigation concentrates on understanding the Quasi-CW-fibre laser parameters on trepanning laser drilled hole quality and speed. The principal findings are based on controlling the recast layer, oxide layer, hole surface characteristic and fatigue performance of the laser drilled samples. The results showed that the high average power of the quasi-CW-fibre lasers can be effectively used to achieve increased trepanning drilling speed without undermining the drilling quality, which is not feasible with a free-space Nd:YAG laser. Also, low peak power and high frequency (of quasi-CW-fibre laser) can be effectively used to produce better laser drilled holes than the high peak power and low frequency, which is common with the traditional millisecond Nd:YAG drilling processes. Recast layer thickness of around 30 μm can be achieved with a trepanning speed of up to 500 mm/min with single orbit Quasi-CW fibre laser drilling of 0.75 mm hole over 5 mm thick material.

  17. Strengthening Purity: Moral Purity as a Mediator of Direct and Extended Cross-Group Friendships on Sexual Prejudice.

    Science.gov (United States)

    Vezzali, Loris; Brambilla, Marco; Giovannini, Dino; Paolo Colucci, Francesco

    2017-01-01

    The present research investigated whether enhanced perceptions of moral purity drive the effects of intergroup cross-group friendships on the intentions to interact with homosexuals. High-school students (N = 639) reported their direct and extended cross-group friendships with homosexuals as well as their beliefs regarding the moral character of the sexual minority. Participants further reported their desire to interact with homosexuals in the future. Results showed that both face-to-face encounters and extended contact with homosexuals increased their perceived moral purity, which in turn fostered more positive behavioral intentions. Results further revealed the specific role of moral purity in this sense, as differential perceptions along other moral domains (autonomy and community) had no mediation effects on behavioral tendencies toward homosexuals. The importance of these findings for improving intergroup relations is discussed, together with the importance of integrating research on intergroup contact and morality.

  18. Initial Stages of Recrystallization in Aluminum of Commercial Purity

    DEFF Research Database (Denmark)

    Hansen, Niels; Bay, Bent

    1979-01-01

    In commercial aluminum with a purity of 99.4 pct, the formation and growth of recrystallization nuclei were studied by techniques such asin-situ annealing in a high voltage electron microscope, transmission electron microscopy and light microscopy. Sample parameters were the initial grain size (3...

  19. A summary of volatile impurity measurements and gas generation studies on MISSTD-1, a high-purity plutonium oxide produced by low-temperature calcination of plutonium oxalate

    Energy Technology Data Exchange (ETDEWEB)

    Berg, John M. [Los Alamos National Laboratory; Narlesky, Joshua E. [Los Alamos National Laboratory; Veirs, Douglas K. [Los Alamos National Laboratory

    2012-06-08

    Plutonium dioxide of high specific surface area was subjected to long-term tests of gas generation in sealed containers. The material preparation and the storage conditions were outside the bounds of acceptable parameters defined by DOE-STD-3013-2012 in that the material was stabilized to a lower temperature than required and had higher moisture content than allowed. The data provide useful information for better defining the bounding conditions for safe storage. Net increases in internal pressure and transient increases in H{sub 2} and O{sub 2} were observed, but were well within the bounds of gas compositions previously shown to not threaten integrity of 3013 containers.

  20. CW ESR studies on endohedral fullerenes

    Science.gov (United States)

    Bartl, Anton; Dunsch, Lothar; Kirbach, Uwe

    1996-12-01

    Electron spin resonance (ESR) spectroscopy is used in this study in connection with the mass spectrometry one of the most promising method to characterize the state of endohedral fullerenes. The aim of this contribution is to study scandium, yttrium, lanthanum, cerium, praseodymium, samarium, europium, holmium, thulium and lutetium containing fullerenes in dependence on the production and handling conditions with respect to their electronic structure. For the most metallofullerenes both single filled and double filled fullerenes were measured. The mass spectrometric signals of single filled fullerenes are much larger than the signals of double and higher filled metallofullerenes. ESR spectroscopic properties were followed especially in solution of isolated metallofullerenes of high purity characterized by well resolved ESR spectra but also of the solid soot extract resulting in low resolved ESR spectra. In this way new information on the electronic states and the influence of oxygen on endohedral metallofullerene were obtained. The interaction of the lanthanofullerence with oxygen is studied in detail. Different stabilities in different solvents in the presence of oxygen were found for La at C82 molecules. For scandium, yttrium and lanthanum containing fullerenes ESR spectra with hyperfine structure splittings corresponding to the nuclear spin of the metal ion were found. Experiments with lanthanoides results in fullerenes, showing mass spectra with lines equivalent to the corresponding endohedral compounds with single and double filed cages, but no ESR spectra due to the interaction of an unpaired electron with the nuclear spin of the lanthanoide ion could be detected in the magnetic field range of 0 to 800 mT.

  1. A Rapid One-Pot Synthesis of Novel High-Purity Methacrylic Phosphonic Acid (PA-Based Polyhedral Oligomeric Silsesquioxane (POSS Frameworks via Thiol-Ene Click Reaction

    Directory of Open Access Journals (Sweden)

    K. Karuppasamy

    2017-05-01

    Full Text Available Herein, we demonstrate a facile methodology to synthesis a novel methacrylic phosphonic acid (PA-functionalized polyhedral oligomeric silsesquioxanes (POSSs via thiol-ene click reaction using octamercapto thiol-POSS and ethylene glycol methacrylate phosphate (EGMP monomer. The presence of phosphonic acid moieties and POSS-cage structure in POSS-S-PA was confirmed by Fourier transform infrared (FT-IR and nuclear magnetic resonance (1H, 29Si and 31P-NMR analyses. Matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF mass spectrum of POSS-S-PA acquired in a dithranol matrix, which has specifically designed for intractable polymeric materials. The observed characterization results signposted that novel organo-inorganic hybrid POSS-S-PA would be an efficacious material for fuel cells as a proton exchange membrane and high-temperature applications due to its thermal stability of 380 °C.

  2. Surpassing the current limitations of high purity H2 production in microbial electrolysis cell (MECs): Strategies for inhibiting growth of methanogens.

    Science.gov (United States)

    Kadier, Abudukeremu; Kalil, Mohd Sahaid; Chandrasekhar, Kuppam; Mohanakrishna, Gunda; Saratale, Ganesh Dattatraya; Saratale, Rijuta Ganesh; Kumar, Gopalakrishnan; Pugazhendhi, Arivalagan; Sivagurunathan, Periyasamy

    2018-02-01

    Microbial electrolysis cells (MECs) are perceived as a potential and promising innovative biotechnological tool that can convert carbon-rich waste biomass or wastewater into hydrogen (H2) or other value-added chemicals. Undesired methane (CH4) producing H2 sinks, including methanogens, is a serious challenge faced by MECs to achieve high-rate H2 production. Methanogens can consume H2 to produce CH4 in MECs, which has led to a drop of H2 production efficiency, H2 production rate (HPR) and also a low percentage of H2 in the produced biogas. Organized inference related to the interactions of microbes and potential processes has assisted in understanding approaches and concepts for inhibiting the growth of methanogens and profitable scale up design. Thus, here in we review the current developments and also the improvements constituted for the reduction of microbial H2 losses to methanogens. Firstly, the greatest challenge in achieving practical applications of MECs; undesirable microorganisms (methanogens) growth and various studied techniques for eliminating and reducing methanogens activities in MECs were discussed. Additionally, this extensive review also considers prospects for stimulating future research that could help to achieve more information and would provide the focus and path towards MECs as well as their possibilities for simultaneously generating H2 and waste remediation. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Elution profiles of tobramycin and vancomycin from high-purity calcium sulphate beads incubated in a range of simulated body fluids.

    Science.gov (United States)

    Cooper, J J; Florance, H; McKinnon, J L; Laycock, P A; Aiken, S S

    2016-09-01

    The aim of this study was to characterise the elution profiles of antibiotics in combination with pharmaceutical grade calcium sulphate beads in phosphate buffered saline and other physiological solutions which more closely mimic the in vivo environment. Synthetic recrystallised calcium sulphate was combined with vancomycin hydrochloride powder and tobramycin sulphate solution and the paste was formed into 3 mm diameter hemispherical beads. Then 2 g of beads were immersed in 2 ml of either phosphate buffered saline, Dulbecco's Modified Eagle Medium or Hartmann's solution and incubated at 37℃ for up to 21 days. At a range of time points, eluent was removed for analysis by liquid chromatography-mass spectrometry (LC-MS). Tobramycin sulphate and vancomycin hydrochloride release was successfully quantified against standard curves from solutions eluted in all three physiological media (phosphate buffered saline, Dulbecco's Modified Eagle Medium and Hartmann's solution) during incubation with calcium sulphate beads. One hour eluate concentrations were high, up to 2602 µg/ml for tobramycin in phosphate buffered saline and 7417 µg/ml for vancomycin, whereas in DMEM, the levels of tobramycin were 2458 µg/ml and 4401 µg/ml for vancomycin. The levels in HRT were 2354 µg/ml for tobramycin and 5948 µg/ml for vancomycin. The results show highest levels of antibiotic elution over the first 24 h, which gradually diminish over the following 21 days. © The Author(s) 2016.

  4. Evaluation of a unique cw laser in radial thermokeratoplasty

    Science.gov (United States)

    Smithpeter, Colin L.; Welch, Ashley J.; Rylander, Henry G., III

    1993-06-01

    A unique continuous wave (cw) holmium laser ((lambda) equals 2.09 micrometers , Rare Earth Medical) has been evaluated as a new heating modality for thermokeratoplasty. Thermokeratoplasty is a refractive surgical procedure for the correction of hyperopia which uses selective heating to reshape the cornea. The holmium laser is highly effective in this procedure due to the high absorption coefficient ((mu) a equals 27.55 cm-1) of the cornea at 2.09 micrometers . The depth of corneal photocoagulation has been evaluated with histological studies of enucleated porcine eyes that were irradiated with the cw Ho:YAG laser. Laser power and exposure time ranged from 300 mW to 800 mW and 100 ms to 800 ms, respectively. The laser was delivered to the eyes via a 600 micrometers low-OH optical fiber. Coagulation depth was determined by birefringence microscopy of the corneal sections. Our studies also compared the effects of contact and non-contact irradiation and found significant advantages with the contact mode. The optimal laser parameters determined from the histology studies were used for in vivo rabbit studies to quantify the refractive correction possible. One coagulation was placed on each of sixteen equiangular rays taken from a central, clear, optical zone in the cornea with a diameter of 7 mm. Refractive changes in the central cornea were quantified with a keratoscope. Initial procedures resulted in refractive changes up to five diopters. The keratoscope results showed a significant regression at three weeks post- operatively.

  5. Production d'isobutène de haute pureté par décomposition du MTBE High-Purity Isobutene Production from Mtbe

    Directory of Open Access Journals (Sweden)

    Meunier P. B.

    2006-11-01

    decomposition is catalyzed by solids with an acid nature. It has mainly been examined on catalysts of the sulfonic-resin type, but solid acid catalysts have recently appeared (zeolites, silica-alumina, supported phosphoric acid, etc. . The different types of catalysts used are examined for the principal reaction and secondary reactions. The formulation of the catalyst and the nature of the active acid sites (Brönsted or Lewis have great influence on the reaction. Data from the literature mainly concern catalysts of the resin type with Brönsted acidity. Concerning catalysts of the oxide type, mention is made of Lewis acid sites catalyzing the principal reaction. The species adsorbed, the mechanisms and kinetic investigations of MTBE decomposition have mainly been examined for sulfonic resins. The most probable mechanisms (mechanism B, page 371 is the following one :(a Ether adsorption on a double center without dissociation. (b Surface reaction between adsorbed ether and a free active center, to give rise to isobutene adsorbed on a double center without dissociation and methanol adsorbed on a single center. This stage is the one that limits the process from the kinetic standpoint. (c Desorption of isobutene and methanol. The corresponding rate equation is given in Table III, and the adsorbed species are given on page . For solid acid catalysts, few data concerning the kinetics are available in the literature. A single equation (Eq. 4, page 371, which was determined experimentally on a gamma-AI2O3 catalyst modified on the surface by silica, is proposed. On a gamma-AI2O3 catalyst, the inhibiting influence of water has been shown for high contents. Secondary reactions are mainly due to the presence of Brönsted acidity. Indeed, the dimerization and trimerization of isobutene involve mechanisms that necessitate going via a carbonium-ion intermediary on Brönsted acid sites (mechanisms on pages 372 and 377. Likewise, the dehydration of methanol is enhanced by the presence of

  6. Helium purity control by thin film gas sensors at the NA48 experiment at CERN

    CERN Document Server

    Guidi, V; Ferroni, M; Petrucci, F; Sberveglieri, G

    1998-01-01

    The authors have implemented a system for monitoring the purity of helium for the NA-48 experiment on high-energy physics at CERN. This measurement is important for correct execution of the experiment. A set of SnO2 sensors was used to the purpose for on-line information on helium purity within the required accuracy.

  7. The effect of incremental gamma-ray doses and incremental neutron fluences upon the performance of self-biased sup 1 sup 0 B-coated high-purity epitaxial GaAs thermal neutron detectors

    CERN Document Server

    Gersch, H K; Simpson, P A

    2002-01-01

    High-purity epitaxial GaAs sup 1 sup 0 B-coated thermal neutron detectors advantageously operate at room temperature without externally applied voltage. Sample detectors were systematically irradiated at fixed grid locations near the core of a 2 MW research reactor to determine their operational neutron dose threshold. Reactor pool locations were assigned so that fast and thermal neutron fluxes to the devices were similar. Neutron fluences ranged between 10 sup 1 sup 1 and 10 sup 1 sup 4 n/cm sup 2. GaAs detectors were exposed to exponential fluences of base ten. Ten detector designs were irradiated and studied, differentiated between p-i-n diodes and Schottky barrier diodes. The irradiated sup 1 sup 0 B-coated detectors were tested for neutron detection sensitivity in a thermalized neutron beam. Little damage was observed for detectors irradiated at neutron fluences of 10 sup 1 sup 2 n/cm sup 2 and below, but signals noticeably degraded at fluences of 10 sup 1 sup 3 n/cm sup 2. Catastrophic damage was appare...

  8. Detection and Analytical Capabilities for Trace Level of Carbon in High-Purity Metals by Laser-Induced Breakdown Spectroscopy with a Frequency Quintupled 213 nm Nd:YAG Laser

    Directory of Open Access Journals (Sweden)

    Masaki Ohata

    2017-01-01

    Full Text Available The laser-induced breakdown spectroscopy (LIBS with a frequency quintupled 213 nm Nd:YAG laser was examined to the analysis of trace level of carbon (C in high-purity metals and its detection and analytical capabilities were evaluated. Though C signal in a wavelength of 247.9 nm, which showed the highest sensitivity of C, could be obtained from Cd, Ti, and Zn ca. 7000 mg kg−1 C in Fe could not be detected due to the interferences from a lot of Fe spectra. Alternative C signal in a wavelength of 193.1 nm could not be also detected from Fe due to the insufficient laser output energy of the frequency quintupled 213 nm Nd:YAG laser. The depth analysis of C by LIBS was also demonstrated and the C in Cd and Zn was found to be contaminated in only surface area whereas the C in Ti was distributed in bulk. From these results, the frequency quintupled 213 nm Nd:YAG laser, which was adopted widely as a commercial laser ablation (LA system coupled with inductively coupled plasma mass spectrometry (ICPMS for trace element analysis in solid materials, could be used for C analysis to achieve simultaneous measurements for both C and trace elements in metals by LIBS and LA-ICPMS, respectively.

  9. The Jewishness of Jesus and Ritual Purity

    National Research Council Canada - National Science Library

    Wassén, Cecilia

    2016-01-01

    Today it is commonplace for historical Jesus scholars to emphasize Jesus’ Jewishness. At thesame time most New Testament scholars deny that he cared about the Jewish purity system,which was a central aspect of early Judaism...

  10. Shape rheocasting of high purity aluminium

    CSIR Research Space (South Africa)

    Curle, UA

    2011-03-01

    Full Text Available ) The HPDC component was a plate of dimensions 100 x 55 x 6 mm excluding the biscuit and the runner. The top-end of the plate was sectioned in the transverse orientation, mounted in bakelite hot mounting resin and finally mechanical polished with colloidal...?Pro MC v6.0 imaging software was used to record the microstructure. The whole HPDC casting (including the plate, runner and biscuit) that was produced for this temperature curve is shown in Figure 2. The surface of the plate is somewhat rough...

  11. High purity pion beam at TRIUMF

    Science.gov (United States)

    Aguilar-Arevalo, A.; Blecher, M.; Bryman, D. A.; Comfort, J.; Doornbos, J.; Doria, L.; Hussein, A.; Ito, N.; Kettell, S.; Kurchaninov, L.; Malbrunot, C.; Marshall, G. M.; Numao, T.; Poutissou, R.; Sher, A.; Walker, B.; Yamada, K.

    2009-10-01

    An extension of the TRIUMF M13 low-energy pion channel designed to suppress positrons based on an energy-loss technique is described. A source of beam channel momentum calibration from the decay π+→e+ν is also described.

  12. High Purity Pion Beam at TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Kettell, S.; Kettell, S.; Aguilar-Arevalo, A.; Blecher, M.; Bryman, D.A.; Comfort, J.; Doornbos, J.; Doria, L.; Hussein, A.; Ito, N.; et al.

    2009-10-11

    An extension of the TRIUMF M13 low-energy pion channel designed to suppress positrons based on an energy-loss technique is described. A source of beam channel momentum calibration from the decay {pi}{sup +} {yields} e{sup +}{nu} is also described.

  13. High purity pion beam at TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Arevalo, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Blecher, M. [Physics Department, Virginia Tech., Blacksburg, VA 24061 (United States); Bryman, D.A. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Comfort, J. [Arizona State University, Tempe, AZ 85287 (United States); Doornbos, J.; Doria, L. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Hussein, A. [University of Northern British Columbia, Prince George, BC, V2N 4Z9 (Canada); Ito, N. [Physics Department, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Kettell, S. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Kurchaninov, L. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Malbrunot, C. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Marshall, G.M. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Numao, T. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada)], E-mail: toshio@triumf.ca; Poutissou, R.; Sher, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Walker, B. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Yamada, K. [Physics Department, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2009-10-11

    An extension of the TRIUMF M13 low-energy pion channel designed to suppress positrons based on an energy-loss technique is described. A source of beam channel momentum calibration from the decay {pi}{sup +}{yields}e{sup +}{nu} is also described.

  14. An Acoustic Demonstration Model for CW and Pulsed Spectrosocopy Experiments

    Science.gov (United States)

    Starck, Torben; Mäder, Heinrich; Trueman, Trevor; Jäger, Wolfgang

    2009-06-01

    High school and undergraduate students have often difficulties if new concepts are introduced in their physics or chemistry lectures. Lecture demonstrations and references to more familiar analogues can be of great help to the students in such situations. We have developed an experimental setup to demonstrate the principles of cw absorption and pulsed excitation - emission spectroscopies, using acoustical analogues. Our radiation source is a speaker and the detector is a microphone, both controlled by a computer sound card. The acoustical setup is housed in a plexiglas box, which serves as a resonator. It turns out that beer glasses are suitable samples; this also helps to keep the students interested! The instrument is controlled by a LabView program. In a cw experiment, the sound frequency is swept through a certain frequency range and the microphone response is recorded simultaneously as function of frequency. A background signal without sample is recorded, and background subtraction yields the beer glass spectrum. In a pulsed experiment, a short sound pulse is generated and the microphone is used to record the resulting emission signal of the beer glass. A Fourier transformation of the time domain signal gives then the spectrum. We will discuss the experimental setup and show videos of the experiments.

  15. Variable Power, Short Microwave Pulses Generation using a CW Magnetron

    Directory of Open Access Journals (Sweden)

    CIUPA, R.

    2011-05-01

    Full Text Available Fine control of microwave power radiation in medical and scientific applications is a challenging task. Since a commercial Continuous Wave (CW magnetron is the most inexpensive microwave device available today on the market, it becomes the best candidate for a microwave power generator used in medical diathermy and hyperthermia treatments or high efficiency chemical reactions using microwave reactors as well. This article presents a new method for driving a CW magnetron with short pulses, using a modified commercial Zero Voltage Switching (ZVS inverter, software driven by a custom embedded system. The microwave power generator designed with this method can be programmed for output microwave pulses down to 1% of the magnetron's power and allows microwave low frequency pulse modulation in the range of human brain electrical activity, intended for medical applications. Microwave output power continuous control is also possible with the magnetron running in the oscillating area, using a dual frequency Pulse Width Modulation (PWM, where the low frequency PWM pulse is modulating a higher resonant frequency required by the ZVS inverter's transformer. The method presented allows a continuous control of both power and energy (duty-cycle at the inverter's output.

  16. Purity- and Gaussianity-bounded uncertainty relations

    Science.gov (United States)

    Mandilara, A.; Karpov, E.; Cerf, N. J.

    2014-01-01

    Bounded uncertainty relations provide the minimum value of the uncertainty assuming some additional information on the state. We derive analytically an uncertainty relation bounded by a pair of constraints, those of purity and Gaussianity. In a limiting case this uncertainty relation reproduces the purity-bounded derived by Man’ko and Dodonov and the Gaussianity-bounded one (Mandilara and Cerf 2012 Phys. Rev. A 86 030102R).

  17. Prediction of free field heave using CW and CH indices

    Directory of Open Access Journals (Sweden)

    Niedźwiedzka Karina

    2016-03-01

    Full Text Available Prediction of free field heave using CW and CH indices. In order to predict free heave in expansive silty clays two methods were applied: CLOD test and double-swelling methods. In both methods CW and CH indices are required respectively to determine the soil heave. The CW index is determined as a slope of straight line of shrinkage curve obtained with a use of CLOD test. In case of double-swelling method two oedometer tests were carried out to determine CH index: constantvolume and consolidation-swell oedometer tests. Comparison between heave values calculated using CW and CH indexes indicated slight differences.

  18. In Vitro Hemocompatibility Testing of Dyneema Purity Fibers in Blood Contact.

    Science.gov (United States)

    Basir, Amir; de Groot, Philip; Gründeman, Paul F; Tersteeg, Claudia; Maas, Coen; Barendrecht, Arjan; van Herwaarden, Joost; Kluin, Jolanda; Moll, Frans; Pasterkamp, Gerard; Roest, Mark

    2015-01-01

    Heart valve and vascular prosthesis implantation is a common procedure for patients with heart valve stenosis or regurgitation and dilated or obstructive vascular disease. Drawbacks of conventional valve prostheses are the requirement for anticoagulant drugs, moderate durability, and suboptimal resistance to fatigue and tear. Dyneema Purity fibers are made from ultra-high-molecular-weight polyethylene filaments and are very thin, flexible, and fatigue and abrasion resistant and have high strength. Therefore, prostheses made from Dyneema Purity fibers might be attractive for use in the minimally invasive treatment of valvular- and vascular diseases. The aim of this study was to test the hemocompatibility of Dyneema Purity fibers in contact with blood. Real-time platelet adhesion in human blood of 3 volunteers was quantified after 5 minutes of perfusion on single filaments (Ø 15 μm) of Dyneema Purity and polyester fibers. Plasma thrombin generation was measured by fluoroscopy for patches of Dyneema Purity fibers and for 5 commonly used polyester and expanded polytetrafluoroethylene cardiovascular prostheses. Platelet adhesion per 1 mm was 6 ± 1.4 on Dyneema Purity filaments and 15 ± 3.4 on polyester filaments (P = 0.02). Total formed thrombin and the time to peak of its maximum were noninferior for patches of Dyneema Purity fibers compared with the reference materials. Dyneema Purity fibers are noninferior in adhesion and coagulation activation compared with commonly used cardiovascular prostheses.

  19. Slot-coupled CW standing wave accelerating cavity

    Science.gov (United States)

    Wang, Shaoheng; Rimmer, Robert; Wang, Haipeng

    2017-05-16

    A slot-coupled CW standing wave multi-cell accelerating cavity. To achieve high efficiency graded beta acceleration, each cell in the multi-cell cavity may include different cell lengths. Alternatively, to achieve high efficiency with acceleration for particles with beta equal to 1, each cell in the multi-cell cavity may include the same cell design. Coupling between the cells is achieved with a plurality of axially aligned kidney-shaped slots on the wall between cells. The slot-coupling method makes the design very compact. The shape of the cell, including the slots and the cone, are optimized to maximize the power efficiency and minimize the peak power density on the surface. The slots are non-resonant, thereby enabling shorter slots and less power loss.

  20. Concepts for the JLab Ampere-Class CW Cryomodule

    CERN Document Server

    Rimmer, Robert; Henry, James; Hicks, William R; Preble, Joseph P; Stirbet, Mircea; Wang, Haipeng; Wilson, Katherine; Wu, Genfa

    2005-01-01

    We describe the concepts and developments underway at JLab as part of the program to develop a new CW cryomodule capable of transporting ampere-level beam currents in a compact FEL. Requirements include real-estate gradient of at least 10 MV/m and very strong HOM damping to push BBU thresholds up by two or more orders of magnitude compared to existing designs. Cavity shape, HOM damping, power couplers, tuners etc. are being designed and optimized for this application. Cavity considerations include a large iris for beam halo, low-RF losses, HOM frequencies and Q's, low peak surface fields, field flatness and microphonics. Module considerations include high packing factor, low static heat leak, image current heating of beam-line components, cost and maintainability. This module is being developed for the next generation ERL based high power FELs but may be useful for other applications such as electron cooling, electron-ion colliders, industrial processing etc.

  1. Design of 57.5 MHz CW RFQ structure for the Rare Isotope ...

    Indian Academy of Sciences (India)

    The principal specifications of the RFQ are: (1) formation of extremely low longitudinal emittance; (2) stable operation over a wide range of voltage for ... CW operation of an accelerating structure leads to a number of requirements for the resonators such as high shunt impedance, efficient water cooling of all parts of the ...

  2. Broadly Tunable, Mode-Hop-Tuned cw Optical Parametric Oscillator Based on Periodically Poled Lithium Niobate

    Science.gov (United States)

    Bisson, Scott E.; Armstrong, Karla M.; Kulp, Thomas J.; Hartings, Matthew

    2001-11-01

    We describe a broadly tunable, cw optical parametric oscillator (OPO) based on periodically poled lithium niobate. The OPO can be tuned over a broad region in the mid IR (2900 -3100 cm-1 ) covering the important C -H stretch region while a high spectral resolution ( volatile organic compounds.

  3. ULTRAVIOLET TRANSITIONS IN EUROPIUM STUDIED WITH A FREQUENCY-DOUBLED CW RING DYE-LASER

    NARCIS (Netherlands)

    Eliel, E.R.; Hogervorst, W.; van Leeuwen, K.A.H.; Post, B.H.

    1981-01-01

    High resolution laser spectroscopy has been applied to the study of three ultraviolet transitions in Europium at λ = 294.8, 295.1 and 295.8 nm. The tunable narrowband UV has been generated by intracavity frequency doubling in a cw ring dye laser using a temperate tuned, Brewster angled ADA crystal.

  4. Engineering Streptavidin and a Streptavidin-Binding Peptide with Infinite Binding Affinity and Reversible Binding Capability: Purification of a Tagged Recombinant Protein to High Purity via Affinity-Driven Thiol Coupling.

    Directory of Open Access Journals (Sweden)

    Dawson Fogen

    Full Text Available To extend and improve the utility of the streptavidin-binding peptide tag (SBP-tag in applications ranging from affinity purification to the reversible immobilization of recombinant proteins, a cysteine residue was introduced to the streptavidin mutein SAVSBPM18 and the SBP-tag to generate SAVSBPM32 and SBP(A18C, respectively. This pair of derivatives is capable of forming a disulfide bond through the newly introduced cysteine residues. SAVSBPM32 binds SBP-tag and biotin with binding affinities (Kd ~ 10-8M that are similar to SAVSBPM18. Although SBP(A18C binds to SAVSBPM32 more weakly than SBP-tag, the binding affinity is sufficient to bring the two binding partners together efficiently before they are locked together via disulfide bond formation-a phenomenon we have named affinity-driven thiol coupling. Under the condition with SBP(A18C tags in excess, two SBP(A18C tags can be captured by a tetrameric SAVSBPM32. The stoichiometry of the disulfide-bonded SAVSBPM32-SBP(A18C complex was determined using a novel two-dimensional electrophoresis method which has general applications for analyzing the composition of disulfide-bonded protein complexes. To illustrate the application of this reversible immobilization technology, optimized conditions were established to use the SAVSBPM32-affinity matrix for the purification of a SBP(A18C-tagged reporter protein to high purity. Furthermore, we show that the SAVSBPM32-affinity matrix can also be applied to purify a biotinylated protein and a reporter protein tagged with the unmodified SBP-tag. The dual (covalent and non-covalent binding modes possible in this system offer great flexibility to many different applications which need reversible immobilization capability.

  5. Managing gas purity in epitaxial growth

    Energy Technology Data Exchange (ETDEWEB)

    Succi, M.; Pirola, S. [SAES, Viale Italia 77, 20020 Lainate Mi (Italy); Ruffenach, S.; Briot, O. [Laboratoire Charles Coulomb - UMR 5221 CNRS-UM2, Universite Montpellier 2, Place Eugene Bataillon - CC074, 34095 Montpellier Cedex 5 (France)

    2011-08-15

    The development of high brightness LEDs is being studied worldwide due to the expectation to replace present light sources because of the higher efficiency and estimated lifetime. The deposition of the epitaxial layers is the most critical step of the LED manufacturing process and has to be carried-out in well controlled conditions to get the necessary uniformity of the epitaxial layers and the proper cleanliness. The most common technology to grow the epitaxial layers is MOVPE, a technology that requires a large quantity of gas to transport the precursors into the process reactor. Control of the cleanliness of the gases used during the process (hydrogen, ammonia, arsine, etc) is necessary to obtain highly efficient and reproducible devices. However, even the use of the cleanest gas source cannot avoid the introduction of impurities when the gas is used in the process reactor. In fact there are several causes that can degrade the actual purity level: the degree of emptiness of the source cylinder, improper procedures during the change out of the cylinder or outgassing from the components in the gas distribution system. These effects can be even worse in research centers where the gas consumption is low and not continuous. A common way to get rid of the above mentioned problems is the adoption of point of use purifiers. Results showing the improvements in the gas quality by adopting point of use purifiers will be presented and discussed. The differences between some widely used hydrogen purification technologies in the compound semiconductor applications will also be evaluated. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Pristine Purity : New Political Parties in Canada

    NARCIS (Netherlands)

    Lucardie, Anthonie

    2007-01-01

    Success sells better than failure; hence new parties receive very little attention from political scientists as long as they remain marginal and fail to win seats in Parliament. Yet in the margins of the party system, they may maintain the pristine purity of political principles and ideas better

  7. 7 CFR 201.60 - Purity percentages.

    Science.gov (United States)

    2010-01-01

    ... Component of a Purity Analysis for (1) Unmixed Seed or (2) Mixed Seed in Which the Particle Weight Ratio Is... Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT...

  8. Purity assessment of condensed tannin fractions by nuclear magnetic resonance (NMR) spectroscopy

    Science.gov (United States)

    Unambiguous investigation of condensed tannin (CT) structure-activity relationships in biological systems requires the use of highly enriched CT fractions of defined chemical purity. Purification of CTs from Sorghum bicolor, Trifolium repens, Theobroma cacao, Lespedeza cuneata, Lotus pedunculatus, a...

  9. Heavy metal removal in an UASB-CW system treating municipal wastewater.

    Science.gov (United States)

    de la Varga, D; Díaz, M A; Ruiz, I; Soto, M

    2013-10-01

    The objective of the present study was to investigate for the first time the long-term removal of heavy metals (HMs) in a combined UASB-CW system treating municipal wastewater. The research was carried out in a field pilot plant constituted for an up-flow anaerobic sludge bed (UASB) digester as a pretreatment, followed by a surface flow constructed wetland (CW) and finally by a subsurface flow CW. While the UASB showed (pseudo) steady state operational conditions and generated a periodical purge of sludge, CWs were characterised by the progressive accumulation and mineralisation of retained solids. This paper analyses the evolution of HM removal from the water stream over time (over a period of 4.7 year of operation) and the accumulation of HMs in UASB sludge and CW sediments at two horizons of 2.7 and 4.0 year of operation. High removal efficiencies were found for some metals in the following order: Sn > Cr > Cu > Pb > Zn > Fe (63-94%). Medium removal efficiencies were registered for Ni (49%), Hg (42%), and Ag (40%), and finally Mn and As showed negative percentage removals. Removal efficiencies of total HMs were higher in UASB and SF units and lower in the last SSF unit. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Pre-treatments applied to oxidized aluminum surfaces to modify the interfacial bonding with bis-1,2-(triethoxysilyl)ethane (BTSE). Part I. High-purity Al with native oxide

    Science.gov (United States)

    Teo, M.; Kim, J.; Wong, P. C.; Wong, K. C.; Mitchell, K. A. R.

    2005-12-01

    A remote microwave-generated H 2 plasma and heating to 250 °C were separately used to modify high-purity oxidized aluminum surfaces and to assess whether these treatments can help enhance adhesion with bis-1,2-(triethoxysilyl)ethane (BTSE) coatings. Different initial oxide surfaces were considered, corresponding to the native oxide and to surfaces formed by the Forest Products Laboratory (FPL) treatment applied for either 15 or 60 min. BTSE is applied from solution at pH 4, and competing processes of etching, protonation (to form OH groups) and coupling (to form Al sbnd O sbnd Si interfacial bonds) occur at the solid-liquid interface. Scanning electron microscopy (SEM) was used to determine how the topographies of the modified Al surfaces changed with the different pre-treatments and with exposure to a buffer solution of pH 4. Secondary-ion mass spectrometry (SIMS) was used to determine the direct amount of Al sbnd O sbnd Si interfacial bonds by measuring the ratio of peak intensities 71-70 amu, while X-ray photoelectron spectroscopy (XPS) was used to determine the overall strength of the silane coating adhesion by measuring the Si 2p signals before and after application of an ultrasonic rinse to the coated sample. Measured Al 2p and O 1s spectra helped assess how the different pre-treatments modified the various Al oxidized surfaces prior to BTSE coating. Pre-treated samples that showed increased Al sbnd O sbnd Si bonding after BTSE coating corresponded to surfaces, which did not show evidence of significant etching after exposure to a pH 4 environment. This suggests that such surfaces are more receptive to the coupling reaction during exposure to the BTSE coating solution. These surfaces include all H 2 plasma-treated samples, the heated native oxide and the sample that only received the 15 min FPL treatment. In contrast, other surfaces that show evidence of etching in pH 4 environments are samples that received lower amounts of Al sbnd O sbnd Si interfacial

  11. Adherence of Staphylococcus aureus to Dyneema Purity® Patches and to Clinically Used Cardiovascular Prostheses

    OpenAIRE

    Basir, Amir; Grundeman, Paul; Moll, Frans; van Herwaarden, Joost; Pasterkamp, Gerard; Nijland, Reindert

    2016-01-01

    Various materials that are used for vascular and heart valve prostheses carry drawbacks: some require anticoagulant drugs or have moderate durability; others are not suitable for endovascular treatment. These prostheses are associated with bacterial infections. A material potentially suitable for prostheses is Dyneema Purity®, made of ultra-high-molecularweight polyethylene. Dyneema Purity® fibers are very thin, flexible, resistant to fatigue and abrasion, and have high strength. S. aureus ad...

  12. Inference of conversion and purity for ETBE reactive distillation

    Directory of Open Access Journals (Sweden)

    Tian Yu-Chu

    2000-12-01

    Full Text Available Reactive distillation (RD, an unconventional and attractive technique, has been applied in fuel ether production. A typical application of RD is the synthesis of the widely used methyl tert-butyl ether (MTBE. RD has also been found to have potential to produce high quality ethyl tert-butyl ether (ETBE, a potential alternative to MTBE. A RD process integrates conventional reaction and separation into a single unit, resulting in extra complexity and dual process objectives, i.e. maximization of reactant conversion and purity of products. The conversion and the purity are thus important variables to be controlled in RD of ETBE. Unfortunately, both of them are not economically and reliably available for closed-loop control. This study aims to develop an effective method to infer the conversion and the purity from multiple temperature measurements that are easily available on-line and in real time. Nonlinear inferential models are recommended for ETBE synthesis with a ten-stage pilot scale RD column. The models are two-variable third-order regressive models, in which the temperature measurements of the reboiler and the bottom reactive section are employed. Experimental design, model identification, and model testing are also investigated.

  13. A Stepped Frequency CW SAR for Lightweight UAV Operation

    National Research Council Canada - National Science Library

    Morrison, Keith

    2005-01-01

    A stepped-frequency continuous wave (SF-CW) synthetic aperture radar (SAR), with frequency-agile waveforms and real-time intelligent signal processing algorithms, is proposed for operation from a lightweight UAV platform...

  14. Analytic Performance Evaluation Design of the MFACP CW Normalizer

    Science.gov (United States)

    1992-09-09

    Gilbert, D. C. - "Algorithm and Software Specification for ACP CW Detection and Tracking," Analysis and Tecnology , Inc., Report no. P-4569-1-91, 31...Dec 91. 3. Gilbert, D. C. - "Automatic Detection Algorithm for ACP CW Processing," Analysis and Tecnology , Inc., Tech. Memo. 90:32/27-34A, 30 Nov 90. 4...J. - "An Analytical Design and Evaluation Methodology for Active SONAR Normalizers (PRELIMINARY),"Analysis and Tecnology , Engineering Technology

  15. Novel Method of Evaluating the Purity of Multiwall Carbon Nanotubes Using Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    Young Chul Choi

    2013-01-01

    Full Text Available We propose the quantitative method of evaluating the purity of multiwall carbon nanotubes (MWCNTs using Raman spectroscopy. High purity MWCNTs were prepared by chemical vapor deposition (CVD to be used as a reference material with 100% purity. Since the intensity and wavenumber of D′′-band located at around 1500 cm−1 were found to be independent of the excitation wavelength of a laser, the purity of MWCNTs was measured by comparing the intensity ratio of D′′-band to G-band (ID′′/IG of the sample with that of a reference material. The established method was verified by testing the mixture of amorphous carbon particles and reference MWCNTs.

  16. On the possibility of developing quasi-CW high-power high-pressure laser on 4p–4s transition of ArI with electron beam—optical pumping: quenching of 4s (3P2) lower laser level

    Science.gov (United States)

    Ionin, A. A.; Kholin, I. V.; L’dov, A. Yu; Seleznev, L. V.; Ustinovskii, N. N.; Zayarnyi, D. A.

    2017-12-01

    A new electron beam-optical procedure is proposed for quasi-cw pumping of high-pressure large-volume He–Ar laser on the 4p[1/2]1–4s[3/2]20 argon atom transition at the wavelength of 912.5 nm. It consists of creation and maintenance of a necessary density of the 4s[3/2]20 metastable state in the gain medium by a fast electron beam and subsequent optical pumping of the upper laser level via the classical three-level scheme using a laser diode. Absorption probing is used to study collisional quenching of Ar* metastable in electron-beam-excited high-pressure He–Ar mixtures with a low content of argon. The rate constants for plasma-chemical reactions Ar*  +  He  +  Ar  >  Ar2*   +  He (3.6  ±  0.4)  ×  10‑33 cm6 s‑1, Ar*  +  2He  >  HeAr*  +  He (4.4  ±  0.9)  ×  10‑36 cm6 s‑1 and Ar*  +  He  >  Products  +  He (2.4  ±  0.3)  ×  10‑15 cm3 s‑1 were for the first time measured.

  17. Integrating in silico and in vitro analysis of peptide binding affinity to HLA-Cw*0102: a bioinformatic approach to the prediction of new epitopes.

    Directory of Open Access Journals (Sweden)

    Valerie A Walshe

    2009-11-01

    Full Text Available Predictive models of peptide-Major Histocompatibility Complex (MHC binding affinity are important components of modern computational immunovaccinology. Here, we describe the development and deployment of a reliable peptide-binding prediction method for a previously poorly-characterized human MHC class I allele, HLA-Cw*0102.Using an in-house, flow cytometry-based MHC stabilization assay we generated novel peptide binding data, from which we derived a precise two-dimensional quantitative structure-activity relationship (2D-QSAR binding model. This allowed us to explore the peptide specificity of HLA-Cw*0102 molecule in detail. We used this model to design peptides optimized for HLA-Cw*0102-binding. Experimental analysis showed these peptides to have high binding affinities for the HLA-Cw*0102 molecule. As a functional validation of our approach, we also predicted HLA-Cw*0102-binding peptides within the HIV-1 genome, identifying a set of potent binding peptides. The most affine of these binding peptides was subsequently determined to be an epitope recognized in a subset of HLA-Cw*0102-positive individuals chronically infected with HIV-1.A functionally-validated in silico-in vitro approach to the reliable and efficient prediction of peptide binding to a previously uncharacterized human MHC allele HLA-Cw*0102 was developed. This technique is generally applicable to all T cell epitope identification problems in immunology and vaccinology.

  18. Adherence of Staphylococcus aureus to Dyneema Purity® Patches and to Clinically Used Cardiovascular Prostheses.

    Science.gov (United States)

    Basir, Amir; Gründeman, Paul; Moll, Frans; van Herwaarden, Joost; Pasterkamp, Gerard; Nijland, Reindert

    2016-01-01

    Various materials that are used for vascular and heart valve prostheses carry drawbacks: some require anticoagulant drugs or have moderate durability; others are not suitable for endovascular treatment. These prostheses are associated with bacterial infections. A material potentially suitable for prostheses is Dyneema Purity®, made of ultra-high-molecular-weight polyethylene. Dyneema Purity® fibers are very thin, flexible, resistant to fatigue and abrasion, and have high strength. S. aureus adherence to Dyneema Purity® was tested and compared with currently used cardiovascular prostheses. We compared adhesion of S. aureus to Dyneema Purity® (1 membrane-based and 1 yarn-composed patch) with 5 clinically used yarn-composed polyester and membrane-based expanded polytetrafluoroethylene patches. Patches were contaminated with S. aureus bacteria and bacterial adherence was quantified. S. aureus adherence was also visualized in flow conditions. Overall, bacterial adherence was higher on yarn-composed prosthesis materials, with a rough surface, than on the membrane-based materials, with a smooth surface. Adherence to Dyneema Purity® materials was non-inferior to the currently used materials. Therefore, patches of Dyneema Purity® might be attractive for use in cardiovascular applications such as catheter-based heart valves and endovascular prostheses by their good mechanical properties combined with their noninferiority regarding bacterial adhesion.

  19. Adherence of Staphylococcus aureus to Dyneema Purity® Patches and to Clinically Used Cardiovascular Prostheses.

    Directory of Open Access Journals (Sweden)

    Amir Basir

    Full Text Available Various materials that are used for vascular and heart valve prostheses carry drawbacks: some require anticoagulant drugs or have moderate durability; others are not suitable for endovascular treatment. These prostheses are associated with bacterial infections. A material potentially suitable for prostheses is Dyneema Purity®, made of ultra-high-molecular-weight polyethylene. Dyneema Purity® fibers are very thin, flexible, resistant to fatigue and abrasion, and have high strength. S. aureus adherence to Dyneema Purity® was tested and compared with currently used cardiovascular prostheses. We compared adhesion of S. aureus to Dyneema Purity® (1 membrane-based and 1 yarn-composed patch with 5 clinically used yarn-composed polyester and membrane-based expanded polytetrafluoroethylene patches. Patches were contaminated with S. aureus bacteria and bacterial adherence was quantified. S. aureus adherence was also visualized in flow conditions. Overall, bacterial adherence was higher on yarn-composed prosthesis materials, with a rough surface, than on the membrane-based materials, with a smooth surface. Adherence to Dyneema Purity® materials was non-inferior to the currently used materials. Therefore, patches of Dyneema Purity® might be attractive for use in cardiovascular applications such as catheter-based heart valves and endovascular prostheses by their good mechanical properties combined with their noninferiority regarding bacterial adhesion.

  20. Stimulating ammonia oxidizing bacteria (AOB) activity drives the ammonium oxidation rate in a constructed wetland (CW).

    Science.gov (United States)

    Su, Yu; Wang, Weidong; Wu, Di; Huang, Wei; Wang, Mengzi; Zhu, Guibing

    2017-12-14

    An integrated approach to document high ammonium oxidation rate in Guanjinggang constructed wetland (GJG-CW) was performed and the results showed that the substantial ammonium oxidation rate could be obtained by enhancing Ammonia Oxidizing Bacteria (AOB) activity rather than Ammonia Oxidizing Archaea (AOA) activity. In the plant-bed/ditch system, ditch center and plant-bed fringe were two active zones for NH4+-N removal with ammonium oxidation rate peaking at 2.98±0.04 and 2.15±0.02mgNkg-1d-1, respectively. The enhanced AOB activity were achieved by increasing water level fluctuations, extending hydraulic retention time (HRT) and stimulating substrate availability, which subsequently enhanced NH4+-N removal by 34.06% in GJG-CW. However, the high AOB activity was not correlated with high AOB abundance, but was instead mostly determined by specific AOB taxa, particularly Nitrosomonas, which dominated in the active AOB. The increased cell-specific AOA activity and high AOA diversity were also achieved using those engineering measures. Although the AOA activity decreased overall with extended HRT and increased NH4+-N contents in GJG-CW, AOA still played a major role on ammonium oxidation in plant-bed soil. The study illustrated that artificially enhancing AOB activity and certain species in anthropogenically polluted water ecosystems would be an effective strategy to improve NH4+-N removal. Copyright © 2017. Published by Elsevier B.V.

  1. A CW 4-rod RFQ for deuterons; Ein Hochleistungs-RFQ-Beschleuniger fuer Deuteronen

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, P.

    2007-06-15

    A four-rod RFQ accelerator has been built which operates in CW mode with a power consumption of 250 kW. The assembly of a high power RFQ structure requires a precise mechanical alignment and field tuning of the electrode field. The field distribution must be very flat to enable a proper operation with few losses. Adjusting of the field distribution is critical in long structures. (orig.)

  2. First lasing of the Darmstadt cw free electron laser

    CERN Document Server

    Brunken, M; Eichhorn, R; Genz, H; Gräf, H D; Loos, H; Richter, A; Schweizer, B; Stascheck, A; Wesp, T

    1999-01-01

    The Darmstadt CW FEL designed for wavelengths between 3 and 10 mu m driven by the superconducting electron accelerator S-DALINAC first lased on December 1st, 1996 and has operated thereafter successfully in the wavelength region between 6.6 and 7.8 mu m. The pulsed electron beam employed had a micro pulse length of about 2ps, with a repetition rate of 10 MHz and a peak current of 2.7 A while its energy was varied between 29.6 and 31.5 MeV. A wedged pole hybrid undulator, with 80 periods each of 0.032 m length and a magnetic field strength of 0.15-0.4T, was located in between a 15.01 m long optical cavity equipped with two high reflectivity (99.8) mirrors of 0.05 m diameter. Due to the low beam current special care with respect to the electron and optical beam properties was necessary to meet the stringent conditions in order to reach a minute small signal gain of at least a few percent resulting in amplification. Saturation was obtained after about 2000 repetitions of the photon pulse inside the cavity. The D...

  3. CW single transverse mode all-fiber Tm3+-doped silica fiber laser

    Science.gov (United States)

    Song, E. Z.; Li, W. H.; You, L.

    2012-04-01

    The CW 25.6 W output power with a slope efficiency of 30.6% respected to the pump power from a CW single transverse mode all-fiber Tm3+-doped Silica Fiber Laser is reported. The all-fiber laser is made up by progressively splicing the pigtail fiber, matched FBG fiber and Tm fiber. The reflective FBG and Tm3+-doped fiber end Fresnel reflection build up the laser resonance cavity. Due to the multi-mode FBG as the reflective mirror, the output laser spectrum is multi-peaks at high output power, but the spectrum width is less than 2 nm at 1.94 μm. We estimate the beam quality to be M 2 = 2.39, clearly indicating nearly diffraction-limited beam propagation.

  4. Hardness variation of welded boron steel using continuous wave (CW) and pulse wave (PW) mode of fiber laser

    Science.gov (United States)

    Yaakob, K. I.; Ishak, M.; Idris, S. R. A.; Aiman, M. H.; Khalil, N. Z.

    2017-09-01

    Recent car manufacturer requirement in lightweight and optimum safety lead to utilization of boron steel with tailor welded blank approach. Laser welding process in tailor welded blank (TWB) production can be applied in continuous wave (CW) of pulse wave (PW) which produce different thermal experience in welded area. Instead of microstructure identification, hardness properties also can determine the behavior of weld area. In this paper, hardness variation of welded boron steel using PW and CW mode is investigated. Welding process is conducted using similar average power for both welding mode. Hardness variation across weld area is observed. The result shows similar hardness pattern across weld area for both welding mode. Hardness degradation at fusion zone (FZ) is due to ferrite formation existence from high heat input applied. With additional slower cooling rate for CW mode, the hardness degradation is become obvious. The normal variation of hardness behavior with PW mode might lead to good strength.

  5. Experimental evaluation of the cw lasing threshold for a Ce:LiCaAlF6 laser.

    Science.gov (United States)

    Alderighi, D; Toci, G; Vannini, M; Parisi, D; Tonelli, M

    2005-09-19

    We present an experimental technique that allows the direct measurement of the continuous wave (cw) lasing threshold and the slope efficiency of a Ce:LiCaAlF6 (Ce:LiCAF) laser source by means of time-resolved measurement in the pulsed regime. We used a long-pulse-duration source to pump a tunable laser and a high-efficiency nondispersive laser in a quasi-stationary lasing regime. We compare the experimental results with earlier theoretical evaluations, and we demonstrate the feasibility of a cw Ce:LiCAF laser. Under the conditions discussed here, our technique can be applied to all the active media that achieved pulsed laser emission to investigate their potential as cw laser active media.

  6. Variable-wavelength second harmonic generation of CW Yb-fibre laser in partially coupled enhancement cavity.

    Science.gov (United States)

    Khripunov, Sergey; Radnatarov, Daba; Kobtsev, Sergey; Skorkin, Aleksey

    2014-03-24

    This work for the first time proposes and studies a method of frequency doubling of CW non-single-frequency fibre lasers with a high-Q resonator partially coupled to the fibre laser cavity. The proposed new approach resulted in the following parameters: laser's maximal output power 880 mW at 536 nm when pumped with 6.2 W at 976 nm, wavelength tuneability range 521-545 nm with the output power at the extreme ends of this range 420 and 220 mW correspondingly. The proposed configuration allows efficient non-linear transformation of both CW and pulsed radiation in a partially coupled enhancement cavity.

  7. Cell culture purity issues and DFAT cells

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Shengjuan [College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi Province 712100 (China); Department of Animal Sciences, Washington State University, Pullman, WA 99164 (United States); Bergen, Werner G. [Program in Cellular and Molecular Biosciences/Department of Animal Sciences, Auburn University, Auburn, AL 36849 (United States); Hausman, Gary J. [Animal Science Department, University of Georgia, Athens, GA 30602-2771 (United States); Zan, Linsen, E-mail: zanls@yahoo.com.cn [College of Animal Science and Technology, Northwest A and F University, Yangling, Shaanxi Province 712100 (China); Dodson, Michael V., E-mail: dodson@wsu.edu [Department of Animal Sciences, Washington State University, Pullman, WA 99164 (United States)

    2013-04-12

    Highlights: •DFAT cells are progeny cells derived from dedifferentiated mature adipocytes. •Common problems in this research is potential cell contamination of initial cultures. •The initial cell culture purity is crucial in DFAT cell research field. -- Abstract: Dedifferentiation of mature adipocytes, in vitro, has been pursued/documented for over forty years. The subsequent progeny cells are named dedifferentiated adipocyte-derived progeny cells (DFAT cells). DFAT cells are proliferative and likely to possess mutilineage potential. As a consequence, DFAT cells and their progeny/daughter cells may be useful as a potential tool for various aspects of tissue engineering and as potential vectors for the alleviation of several disease states. Publications in this area have been increasing annually, but the purity of the initial culture of mature adipocytes has seldom been documented. Consequently, it is not always clear whether DFAT cells are derived from dedifferentiated mature (lipid filled) adipocytes or from contaminating cells that reside in an impure culture.

  8. Noise considerations for vital signs CW radar sensors

    DEFF Research Database (Denmark)

    Jensen, Brian Sveistrup; Jensen, Thomas; Zhurbenko, Vitaliy

    2011-01-01

    The use of continuous wave (CW) radars for measuring human vital signs have recently received a lot of attention due to its many promising applications like monitoring people at hospitals or infants at home without the need for wired sensors. This paper briefly presents the typical CW radar setup...... and the underlying signal theory for such sensors. Then to point out and especially clarify one of the most important effects aiding the design of vital signs radars (VSR), a more detailed discussion concerning phase noise cancellation (or filtering) by range correlation is given. This discussion leads to some...

  9. CW laser induced crystallization of thin amorphous silicon films deposited by EBE and PECVD

    Energy Technology Data Exchange (ETDEWEB)

    Said-Bacar, Z., E-mail: zabardjade@yahoo.fr [InESS (UMR 7163 CNRS-UDS), 23 rue de Loess, 67037 Strasbourg Cedex 2 (France); Prathap, P. [InESS (UMR 7163 CNRS-UDS), 23 rue de Loess, 67037 Strasbourg Cedex 2 (France); Cayron, C. [CEA, LITEN, DEHT, Minatec, 17 rue des Martyrs, 38054 Cedex 9 (France); Mermet, F. [IREPA LASER, Pole API - Parc d' Innovation, 67400 Illkirch (France); Leroy, Y.; Antoni, F.; Slaoui, A.; Fogarassy, E. [InESS (UMR 7163 CNRS-UDS), 23 rue de Loess, 67037 Strasbourg Cedex 2 (France)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer The effect of hydrogen in CW laser crystallization of hydrogenated amorphous silicon thin films has been investigated. Black-Right-Pointing-Pointer Large hydrogen content results in decohesion of the films due to hydrogen effusion. Black-Right-Pointing-Pointer Very low hydrogen content or hydrogen free amorphous silicon film are suitable for crystallization induced by CW laser. Black-Right-Pointing-Pointer Grains of size between 20 and 100 {mu}m in width and about 200 {mu}m in long in scanning direction are obtained with these latter films. - Abstract: This work presents the Continuous Wave (CW) laser crystallization of thin amorphous silicon (a-Si) films deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) and by Electron Beam Evaporation (EBE) on low cost glass substrate. The films are characterized by Elastic Recoil Detection Analysis (ERDA) and by Fourier-Transform Infrared (FTIR) spectroscopy to evaluate the hydrogen content. Analysis shows that the PECVD films contain a high hydrogen concentration ({approx}10 at.%) while the EBE films are almost hydrogen-free. It is found that the hydrogen is in a bonding configuration with the a-Si network and in a free form, requiring a long thermal annealing for exodiffusion before the laser treatment to avoid explosive effusion. The CW laser crystallization process of the amorphous silicon films was operated in liquid phase regime. We show by Electron Backscatter Diffraction (EBSD) that polysilicon films with large grains can be obtained with EBE as well as for the PECVD amorphous silicon provided that for the latest the hydrogen content is lower than 2 at.%.

  10. Design of 57.5 MHz cw RFQ for medium energy heavy ion superconducting linac

    Directory of Open Access Journals (Sweden)

    P. N. Ostroumov

    2002-06-01

    Full Text Available The nuclear science community considers the construction of the Rare Isotope Accelerator (RIA facility as a top priority. The RIA includes a 1.4 GV superconducting linac for production of 400 kW cw heavy ion beams. The initial acceleration of heavy ions delivered from an electron cyclotron resonance ion source can be effectively performed by a 57.5 MHz 4-m long room temperature RFQ. The principal specifications of the RFQ are (i formation of extremely low longitudinal emittance, (ii stable operation over a wide range of voltage for acceleration of various ion species needed for RIA operation, and (iii simultaneous acceleration of two-charge states of uranium ions. cw operation of an accelerating structure leads to a number of requirements for the resonators such as high shunt impedance, efficient water cooling of all parts of the resonant cavity, mechanical stability together with precise alignment, reliable rf contacts, a stable operating mode, and fine tuning of the resonant frequency during operation. To satisfy these requirements a new resonant structure has been developed. This paper discusses the beam dynamics and electrodynamics design of the RFQ cavity, as well as some aspects of the mechanical design of the low-frequency cw RFQ.

  11. CW ND:YAG laser welding of dissimilar sheet metals

    CSIR Research Space (South Africa)

    Theron, M

    2007-10-01

    Full Text Available A 4kW CW Nd:YAG laser was used for lap welding of three different dissimilar sheet metal combinations, namely 316L S/S - Ti64, 316L S/S - Al 5251 and Al 1200 – Cu (99.85%). A welding matrix of laser power, travel speed and spot sizes...

  12. Applications of KHZ-CW Lidar in Ecological Entomology

    Science.gov (United States)

    Malmqvist, Elin; Brydegaard, Mikkel

    2016-06-01

    The benefits of kHz lidar in ecological entomology are explained. Results from kHz-measurements on insects, carried out with a CW-lidar system, employing the Scheimpflug principle to obtain range resolution, are presented. A method to extract insect events and analyze the large amount of lidar data is also described.

  13. Singly resonant cw OPO with simple wavelength tuning.

    Science.gov (United States)

    Vainio, Markku; Peltola, Jari; Persijn, Stefan; Harren, Frans J M; Halonen, Lauri

    2008-07-21

    A singly resonant continuous-wave optical parametric oscillator (cw OPO) is described. The OPO contains no intracavity etalon, which makes its wavelength tuning simple and straightforward, including only temperature tuning of the nonlinear crystal and wavelength tuning of the pump laser. The OPO provides watt-level output in the mid-infrared region and operates reliably without mode hops for several hours.

  14. Large scale CW ECRH systems: Meeting a challenge

    NARCIS (Netherlands)

    Erckmann, V.; Kasparek, W.; Plaum, B.; Lechte, C.; Petelin, M.I.; Bruschi, A.; D'Arcangelo, O.; Bin, W.; Braune, H.; Braber, R. van den; Doelman, N.J.; Gantenbein, G.; Laqua, H.P.; Lubiako, L.; Marushchenko, N.B.; Michel, G.; Thumm, M.; Stuttgart, I.

    2011-01-01

    Electron Cyclotron Resonance Heating (ECRH) systems for next step-fusion devices like W7-X and ITER operate in CW-mode and provide a large flexibility to comply with various physics demands such as plasma start-up, heating and current drive, as well as configuration and MHD control. The request for

  15. Uncertainty estimates of purity measurements based on current information: toward a "live validation" of purity methods.

    Science.gov (United States)

    Apostol, Izydor; Kelner, Drew; Jiang, Xinzhao Grace; Huang, Gang; Wypych, Jette; Zhang, Xin; Gastwirt, Jessica; Chen, Kenneth; Fodor, Szilan; Hapuarachchi, Suminda; Meriage, Dave; Ye, Frank; Poppe, Leszek; Szpankowski, Wojciech

    2012-12-01

    To predict precision and other performance characteristics of chromatographic purity methods, which represent the most widely used form of analysis in the biopharmaceutical industry. We have conducted a comprehensive survey of purity methods, and show that all performance characteristics fall within narrow measurement ranges. This observation was used to develop a model called Uncertainty Based on Current Information (UBCI), which expresses these performance characteristics as a function of the signal and noise levels, hardware specifications, and software settings. We applied the UCBI model to assess the uncertainty of purity measurements, and compared the results to those from conventional qualification. We demonstrated that the UBCI model is suitable to dynamically assess method performance characteristics, based on information extracted from individual chromatograms. The model provides an opportunity for streamlining qualification and validation studies by implementing a "live validation" of test results utilizing UBCI as a concurrent assessment of measurement uncertainty. Therefore, UBCI can potentially mitigate the challenges associated with laborious conventional method validation and facilitates the introduction of more advanced analytical technologies during the method lifecycle.

  16. Highly Accurate Sensor for High-Purity Oxygen Determination Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this STTR Phase I effort, Los Gatos Research (LGR) and Professor Scott Sanders (Mechanical Engineering Department, University of Wisconsin ? Madison) propose to...

  17. Design of the 3.7 GHz, 500 kW CW circulator for the LHCD system of the SST-1 tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Dixit, Harish V., E-mail: hvdixit48@yahoo.com [Veermata Jijabai Technological Institute, Mumbai, Maharashtra 400019 (India); Jadhav, Aviraj R. [Veermata Jijabai Technological Institute, Mumbai, Maharashtra 400019 (India); Jain, Yogesh M. [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094 (India); Cheeran, Alice N. [Veermata Jijabai Technological Institute, Mumbai, Maharashtra 400019 (India); Gupta, Vikas [Vidyavardhini' s College of Engineering and Technology, Vasai, Maharashtra 401202 (India); Sharma, P.K. [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India); Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094 (India)

    2017-06-15

    Highlights: • Design of a 500 kW CW circulator for LHCD system at 3.7 GHz. • Mechanism for thermal management of ferrite tile. • Scheme for uniform magnetisation of the ferrite tiles. • Design of high CW power CW quadrature and 180 ° hybrid coupler. - Abstract: Circulators are used in high power microwave systems to protect the vacuum source against reflection. The Lower Hybrid Current Drive (LHCD) system of SST-1 tokamak commissioned at IPR, Gandhinagar in India comprises of four high power circulators to protect klystrons (supplying 500 kW CW each at 3.7 GHz) which power the system. This paper presents the design of a Differential Phase Shift Circulator (DPSC) capable of handling 500 kW CW power at 3.7 GHz so that four circulators can be used to protect the four available klystrons. As the DPSC is composed by three main components, viz., magic tee, ferrite phase shifter and 3 dB hybrid coupler, the designing of each of the proposed components is described. The design of these components is carried out factoring various multiphysics aspects of RF, heating due to high CW power and magnetic field requirement of the ferrite phase shifter. The primary objective of this paper is to present the complete RF, magnetic and thermal design of a high CW power circulator. All the simulations have been carried out in COMSOL Multiphysics. The designed circulator exhibits an insertion loss of 0.13 dB with a worst case VSWR of 1.08:1. The total length of the circulator is 3 m.

  18. Broad-band chopper for a CW proton linac at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Gianfelice-Wendt, E.; Lebedev, V.A.; Solyak, N.; Nagaitsev, S.; Sun, D.; /Fermilab

    2011-03-01

    The future Fermilab program in the high energy physics is based on a new facility called the Project X [1] to be built in the following decade. It is based on a 3 MW CW linear accelerator delivering the 3 GeV 1 mA H{sup -} beam to a few experiments simultaneously. Small fraction of this beam will be redirected for further acceleration to 8 GeV to be injected to the Recycler/Main Injector for a usage in a neutrino program and other synchrotron based high energy experiments. Requirements and technical limitations to the bunch-by-bunch chopper for the Fermilab Project X are discussed.

  19. Design of multi-frequency CW radars

    CERN Document Server

    Jankiraman, Mohinder

    2007-01-01

    This book deals with the basic theory for design and analysis of Low Probability of Intercept (LPI) radar systems. The design of one such multi-frequency high resolution LPI radar, PANDORA, is covered.

  20. Fashion Brand Purity and Firm Performance

    Directory of Open Access Journals (Sweden)

    Jin-hui Zheng

    2013-01-01

    Full Text Available A large number of prior empirical research and case studies used qualitative methodology to discuss the fashion brand dilution resulting from consumer base extension from the target group(s to the nontarget groups and its impacts. From a different perspective, this paper establishes a dynamic brand dilution and performance model, demonstrating how dynamic changes of sales volumes involving the two consumer groups affect the degree of brand dilution and the performance of the brand. We incorporate the factor “brand purity” to the model as a quantitative measure of brand dilution level that affects firm annual revenue and profit change comprehensively in iteration. Our model suggests that fashion brands, especially luxury brands, can be easily diluted under the pressure of firm growth, and the brands suffer the significant negative impact on their revenues and profit. While increasing sales volume can aggravate the negative consequences, brand purity can be increased through limiting the consumer base to the target group only.

  1. Experiment for buried pipes by stepped FM-CW radar; Step shiki FM-CW radar ni yoru maisetsukan tansa jikken

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K.; Ito, M. [Kawasaki Geological Engineering, Co. Ltd., Tokyo (Japan); Tanabe, K. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1997-05-27

    The underground radar exploration is adopted to surveys of cavity under the road and buried pipes since the result of high resolution is obtained. However, the explorative depth of the radar is shallow, 2-3m in soil basement, and its applicable field has been limited. The continuous wave radar (FM-CW radar) was devised to get deeper explorative depth, but has been used for the geological structure survey such as the fault survey since it is lower in resolution as compared with the pulse radar. Therefore, to make use of characteristics of the continuous wave radar and enhance resolution in the shallow part, an experiment on buried pipes was conducted for the purpose of assessing and improving the FM-CW radar. In this processing, the wave form treatment used in the reflection method seismic survey was adopted for the radar survey. There are some problems, but it is effective to adopt the same algorithm to that used in the seismic survey to the radar exploration. The explorative depth was discussed from the damping rate of electromagnetic waves and dynamic range of facilities of the experimental site, and 7m was obtained. 5 figs., 1 tab.

  2. Survey of the preparation, purity, and availability of silanes

    Energy Technology Data Exchange (ETDEWEB)

    Lorenz, J.H.

    1983-12-01

    Silane and disilane are currently available as prepared for the semiconductor market. Published or public information on preparative methods for monosilane and higher silanes are discussed. Purification techniques are reviewed. Data from current silane suppliers are tabulated. A short review of the silanes in Japan is given. Analytical procedures are not now perfected to determine group 3 or 5 elements in silane. All commercial silanes contain certain impurities. There is no simple one step purification technique for silane which a user could easily operate. Typical and actual analyses of commercial silane are given. Disilane is still in the development stage with only small quantities available at very high prices. The silane process developed in part under the DOE/JPL Flat Plate Solar Array project by Union Carbide is summarized. Higher purity silanes are now appearing on the market. These should be useful in the photovoltaic area.

  3. Determination of continuous variable entanglement by purity measurements.

    Science.gov (United States)

    Adesso, Gerardo; Serafini, Alessio; Illuminati, Fabrizio

    2004-02-27

    We classify the entanglement of two-mode Gaussian states according to their degree of total and partial mixedness. We derive exact bounds that determine maximally and minimally entangled states for fixed global and marginal purities. This characterization allows for an experimentally reliable estimate of continuous variable entanglement based on measurements of purity.

  4. 10 CFR 36.63 - Pool water purity.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Pool water purity. 36.63 Section 36.63 Energy NUCLEAR... § 36.63 Pool water purity. (a) Pool water purification system must be run sufficiently to maintain the conductivity of the pool water below 20 microsiemens per centimeter under normal circumstances. If pool water...

  5. Peak Purity Assessments in Chrmatography: A Case Study of ...

    African Journals Online (AJOL)

    This work examines the applicability of different peak purity and/or homogeneity deconvolution algorithms for the evaluation of chromatographic purity and/or homogeneity in chlorpromazine hydrochloride, in the order of the algorithm\\'s increasing complexity. The methods are examined for usefulness with a view to possible ...

  6. Purity and crystallinity of microwave synthesized antimony sulfide microrods

    Energy Technology Data Exchange (ETDEWEB)

    Martínez-Alonso, Claudia, E-mail: claudiamartinezalonso30@gmail.com [Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, 76010 (Mexico); Olivos-Peralta, Eliot U. [Instituto de Energías Renovables, Universidad NacionalAutónoma de México, Temixco, Morelos, 62580 (Mexico); Sotelo-Lerma, Mérida [Universidad de Sonora, Hermosillo, Sonora, 83000 (Mexico); Sato-Berrú, Roberto Y. [Centro de Ciencias Aplicadas y Desarrollo Tecnológico, Universidad Nacional Autónoma de México, MéxicoD.F., 04510 (Mexico); Mayén-Hernández, S.A. [Facultad de Química, Universidad Autónoma de Querétaro, Querétaro, Querétaro, 76010 (Mexico); Hu, Hailin, E-mail: hzh@ier.unam.mx [Instituto de Energías Renovables, Universidad NacionalAutónoma de México, Temixco, Morelos, 62580 (Mexico)

    2017-01-15

    Antimony sulfide (Sb{sub 2}S{sub 3}) is a promising semiconductor material for solar cell applications. In this work, microrods of Sb{sub 2}S{sub 3} were synthesized by microwave heating with different sulfur sources, solvents, temperature, heating rate, power, and solution concentration. It was found that 90% of stoichiometric Sb{sub 2}S{sub 3} can be obtained with thiourea (TU) or thioacetamide (TA) as sulfur sources and that their optical band gap values were within the range of 1.59–1.60 eV. The most crystalline Sb{sub 2}S{sub 3} were obtained by using TU. The morphology of the Sb{sub 2}S{sub 3} with TU the individual rods were exhibited, whereas rods bundles appeared in TA-based products. The solvents were ethylene glycol (EG) and dimethylformamide (DMF). EG generates more heat than DMF during the microwave synthesis. As a result, the Sb{sub 2}S{sub 3} obtained with EG contained a larger percentage of oxygen and smaller crystal sizes compared to those from DMF. On the other hand, the length and diameter of Sb{sub 2}S{sub 3} microrods can be increased by applying higher heating power although the crystal size did not change at all. In summary, pure and highly crystalline Sb{sub 2}S{sub 3} microrods of 6–10 μm long and 330–850 nm in diameter can be obtained by the microwave method with a careful selection of chemical and thermodynamic parameters of the synthesis. - Highlights: • Purity up to 90% of crystalline Sb{sub 2}S{sub 3} nanorods can be obtained by microwave heating. • The combination of solvent and sulfide type affects crystallinity & purity of Sb2S3. • The high pressure generated in microwave heating helps to form Sb{sub 2}S{sub 3} nanorods.

  7. Testing culture purity in prokaryotes: criteria and challenges.

    Science.gov (United States)

    Pinevich, Alexander V; Andronov, Eugeny E; Pershina, Elizaveta V; Pinevich, Agnia A; Dmitrieva, Helena Y

    2018-02-27

    Reliance on pure cultures was introduced at the beginning of microbiology as a discipline and has remained significant although their adaptive properties are essentially dissimilar from those of mixed cultures and environmental populations. They are needed for (i) taxonomic identification; (ii) diagnostics of pathogens; (iii) virulence and pathogenicity studies; (iv) elucidation of metabolic properties; (v) testing sensitivity to antibiotics; (vi) full-length genome assembly; (vii) strain deposition in microbial collections; and (viii) description of new species with name validation. Depending on the specific task there are alternative claims for culture purity, i.e., when conventional criteria are satisfied or when looking deeper is necessary. Conventional proof (microscopic and plating controls) has a low resolution and depends on the observer's personal judgement. Phenotypic criteria alone cannot prove culture purity and should be complemented with genomic criteria. We consider the possible use of DNA high-throughput culture sequencing data to define criteria for only one genospecies, axenic state detection panel and only one genome. The second and third of these are preferable, although their resolving capacity (depth) is limited. Because minor contaminants may go undetected, even with deep sequencing, the reliably pure culture would be a clonal culture launched from a single cell or trichome (multicellular bacterium). Although this type of culture is associated with technical difficulties and cannot be employed on a large scale (the corresponding inoculums may have low chances of growth when transferred to solid media), it is hoped that the high-throughput culturing methods introduced by 'culturomics' will overcome this obstacle.

  8. Thermal conductivity, electrical resistivity and Seebeck coefficient of high purity iron and selected iron alloys from 90 K to 400 K. [Fe--1. 14 Cr, Fe--2. 96 Cr, Fe--1. 15 Cr--1. 30 Ni, and Fe--3. 15 Ni

    Energy Technology Data Exchange (ETDEWEB)

    Holder, T.K.

    1977-06-01

    The thermal conductivity, electrical resistivity, and Seebeck coefficient of high-purity iron, two iron--chromium alloys, one iron--nickel alloy, and one iron--chromium--nickel alloy were measured over the temperature range from 90 K to 400 K. Smoothed values for the thermal conductivity and electrical resistivity were used to calculate the electronic thermal conductivity, the lattice conductivity, and the Lorenz function by means of a binary alloy separation technique. The lattice conductivity and Lorenz function exhibited little change due to the addition of chromium; however, the addition of small amounts of nickel resulted in significant property changes. The lattice conductivity at high temperatures was calculated from theory and compared to experimental results. Good agreement between theory and experimental data was obtained. 17 figures, 29 tables.

  9. Laser Photon Force Measurements using a CW Laser

    Science.gov (United States)

    Gray, Perry; Edwards, David L.; Carruth, M. Ralph, Jr.; Munafo, Paul M. (Technical Monitor)

    2002-01-01

    The photon force resulting from the non-damaging impact of laser derived photons on a metallic target was measured using a vacuum compatible microbalance. This experiment quantitatively verified that the force resulting from laser photons impacting a reflective surface is measurable and predictable. The photon wavelength is 1064 mn and the laser is a multi-mode 30OW Nd YAG continuous wave (CW) laser.

  10. CW Energy Recovery Operation of XFELs

    Energy Technology Data Exchange (ETDEWEB)

    Jacek Sekutowicz; S. Bogacz; Dave Douglas; Peter Kneisel; Gwyn P. Wiliams; Massimo Ferrario; Luca Serafini; Ilan Ben-Zvi; James Rose; Triveni Srinivasan-Rao; Patrick Colestock; Wolf-Dietrich Moeller; Bernd Petersen; Dieter Proch; S. Simrock; James B. Rosenzweig

    2003-09-01

    Commissioning of two large coherent light facilities at SLAC and DESY should begin in 2008 and in 2011 respectively. In this paper we look further into the future, hoping to answer, in a very preliminary way, two questions. First: What will the next generation of the XFEL facilities look like ? Believing that super-conducting technology offers several advantages over room-temperature technology, such as high quality beams with highly populated bunches and the possibility of energy recovery or higher overall efficiency, we focus this preliminary study on the superconducting option. From this belief the second question arises: ''What modifications in superconducting technology and in machine design are needed, as compared to the present DESY XFEL, and what kind of R&D program is required over the next few years to arrive at a technically feasible solution with even higher brilliance and increased overall conversion of AC power to photon beam power. In this paper we will very often refer to and profit from the DESY XFEL design, acknowledging its many technically innovative solutions.

  11. Feasibility and conceptual design of a C.W. positron source at CEBAF

    Energy Technology Data Exchange (ETDEWEB)

    Golge, Serkan [Old Dominion Univ., Norfolk, VA (United States)

    2010-08-01

    A feasibility study of a CW positron source for the 12 GeV upgrade at Jefferson Lab (JLAB) is provided. The proposed ≥ 100 nA Continuous Wave (CW) positron source at JLAB has several unique and challenging characteristics: high current incident electron beam at 126 MeV with a high beam power (up to a MW); CW e- beam and CW e+ production. The multiple scattering is a dominant process when creating e+ in a target, which results a large phase space area of the emitted positrons. An admittance study was done at CEBAF to find the maximum phase space area, which is tolerated in the machine. The measured geometrical transverse admittance (A) were Ax =10 and Ay = 5 mm∙mrad at the injector. Energy spread measurement was also done at the ARC1. The fractional spread limit in the ARC1 was measured as δ = 3×10-3 at 653 MeV. By using the optimized results and the CEBAF parameters, three positron injector configurations are proposed; Combined Function Magnet, Two-Dipole and Microtron Dipole configurations. With the assumptions made, by using 126 MeV Ⓧ10 mA e- beam impinging on a 2 mm W target with a 100 μm spot size, we can get up to 3 μA useful e+ current at the North Linac connection. One of the biggest challenges is the target design, which the deposited power is about 60 kW. ILC designs project power deposition up to 13 kW, which would allow the creation of a e+ beam of up to 650 nA otherwise. The results of analytic and monte carlo simulations of the positron production, capture and acceleration are presented. For the target design, a review is presented of solutions for the high power production target. Portions of this dissertation work have been published in two conference proceedings.

  12. High Power CW Superconducting Linacs for EURISOL and XADS

    CERN Document Server

    Biarrotte, J L

    2004-01-01

    A multi-MW superconducting proton linac is proposed as the baseline solution for the EURISOL and the XADS driver accelerators. In the EURISOL project, which studies the design of the next-generation European ISOL facility, it is used to produce both neutron-deficient and neutron-rich exotic nuclei far from the valley of stability. In the PDS-XADS project, which aims to the demonstration of the feasibility of an ADS system for nuclear waste transmutation, it is used to produce the neutron flux required by the associated sub-critical reactor. In this paper, we report the main results and conclusions reached within these preliminary design studies. A special emphasis is given on the on-going and future R&D to be done to accomplish the demonstration of the full technology.

  13. Laparoscopic Fluorescent Visualization of the Ureter With Intravenous IRDye800CW.

    Science.gov (United States)

    Korb, Melissa L; Huh, Warner K; Boone, Jonathan D; Warram, Jason M; Chung, Thomas K; de Boer, Esther; Bland, Kirby I; Rosenthal, Eben L

    2015-01-01

    Ureter injury is a serious complication of laparoscopic surgery. Current strategies to identify the ureters, such as placement of a ureteral stent, carry additional risks for patients. We hypothesize that the systemically injected near-infrared (NIR) dye IRDye800CW-CA can be used to visualize ureters intraoperatively. Adult female mixed-breed pigs weighing 24 to 41 kg (n = 2 per dose) were given a 30, 60, or 120 μg/kg systemic injection of IRDye800CW-CA. Using the Food and Drug Administration-cleared Pinpoint laparoscopic NIR system, images of the ureter and bladder were captured every 10 minutes for 60 minutes after injection. To determine the biodistribution of the dye, tissues were collected for ex vivo analysis with the Pearl Impulse system. ImageJ software was used to quantify fluorescence signal and signal-to-background ratio (SBR) for the intraoperative images. The ureter was identified in all pigs at each dose, with peak intensity reached by 30 minutes and remaining elevated throughout the duration of imaging (60 minutes). The 60 μg/kg dose was determined to be optimal for differentiating ureters according to absolute fluorescence (>60 counts/pixel) and SBR (3.1). Urine fluorescence was inversely related to plasma fluorescence (R(2) = -0.82). Ex vivo imaging of kidney, ureter, bladder, and abdominal wall tissues revealed low fluorescence. Systemic administration of IRDye800CW-CA shows promise in providing ureteral identification with high specificity during laparoscopic surgery. The low dose required, rapid time to visualization, and absence of invasive ureteral instrumentation inherent to this technique may reduce complications related to pelvic surgery. Copyright © 2015 AAGL. Published by Elsevier Inc. All rights reserved.

  14. A 700 MHZ, 1 MW CW RF System for a FEL 100mA RF Photoinjector

    CERN Document Server

    Roybal, William; Reass, William; Rees, Daniel; Tallerico, Paul J; Torrez, Phillip A

    2005-01-01

    This paper describes a 700 MHz, 1 Megawatt CW, high efficiency klystron RF system utilized for a Free Electron Laser (FEL) high-brightness electron photoinjector (PI). The E2V klystron is mod-anode tube that operates with a beam voltage of 95 kV. This tube, operating with a 65% efficiency, requires ~96 watts of input power to produce in excess of 1 MW of output power. This output drives the 3rd cell of a 2½-cell, p-mode PI cavity through a pair of planar waveguide windows. Coupling is via a ridge-loaded tapered waveguide section and "dog-bone" iris. This paper will present the design of the RF, RF transport, coupling, and monitoring/protection systems that are required to support CW operations of the 100 mA cesiated, semi-porous SiC photoinjector.

  15. Design and calibration of a CW coherent laser radar

    Science.gov (United States)

    Claesson, T.; Gullberg, K.; Letalick, D.; Renhorn, I.; Steinvall, O.; Widen, A.

    1984-01-01

    The design, calibration and performance of a CW coherent laser radar testbed system is described. Detector responsiveness and detector noise in a heterodyne system is considered. A detailed evaluation of beam propagation and phase front matching is given. The final system is supplemented with a digital image memory, a galvanometer scanner and a boresighted TV camera. Analysis of images obtained indoors from a diffuse reference target reveal the well known Rayleigh statistics for the signal amplitude and speckle "cells' which on the average have a diameter equal to the tranceiver aperture. The influence of atmospheric turbulence on transmitter beam size and signal fluctuations is studied over a 500 m path.

  16. Use of Multipass Recirculation and Energy Recovery In CW SRF X-FEL Driver Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, David; Akers, Walt; Benson, Stephen V.; Biallas, George; Blackburn, Keith; Boyce, James; Bullard, Donald; Coleman, James; Dickover, Cody; Ellingsworth, Forrest; Evtushenko, Pavel; Fisk, Sally; Gould, Christopher; Gubeli, Joseph; Hannon, Fay; Hardy, David; Hernandez-Garcia, Carlos; Jordan, Kevin; Klopf, John; Kortze, J.; Legg, Robert; Li, Rui; Marchlik, Matthew; Moore, Steven W.; Neil, George; Powers, Thomas; Sexton, Daniel; Shin, Ilkyoung; Shinn, Michelle D.; Tennant, Christopher; Terzic, Balsa; Walker, Richard; Williams, Gwyn P.; Wilson, G.; Zhang, Shukui

    2010-08-01

    We discuss the use of multipass recirculation and energy recovery in CW SRF drivers for short wavelength FELs. Benefits include cost management (through reduced system footprint, required RF and SRF hardware, and associated infrastructure - including high power beam dumps and cryogenic systems), ease in radiation control (low drive beam exhaust energy), ability to accelerate and deliver multiple beams of differing energy to multiple FELs, and opportunity for seamless integration of multistage bunch length compression into the longitudinal matching scenario. Issues include all those associated with ERLs compounded by the challenge of generating and preserving the CW electron drive beam brightness required by short wavelength FELs. We thus consider the impact of space charge, BBU and other environmental wakes and impedances, ISR and CSR, potential for microbunching, intra-beam and beam-residual gas scattering, ion effects, RF transients, and halo, as well as the effect of traditional design, fabrication, installation and operational errors (lattice aberrations, alignment, powering, field quality). Context for the discussion is provided by JLAMP, the proposed VUV/X-ray upgrade to the existing Jefferson Lab FEL.

  17. Toward an integrated computational approach to CW-ESR spectra of free radicals.

    Science.gov (United States)

    Barone, Vincenzo; Polimeno, Antonino

    2006-10-28

    Interpretation of structural properties and dynamic behaviour of molecules in solution is of fundamental importance to understand their stability, chemical reactivity and catalytic action. Information can be gained, in principle, by a variety of spectroscopic techniques, magnetic as well as optical. In particular, continuous wave electron spin resonance (CW-ESR) measurements are highly informative. However, the wealth of structural and dynamic information which can be extracted from ESR spectroscopy is, at present, limited by the necessity of employing computationally efficient models, which are increasingly complex as they need to take into account diverse relaxation processes affecting the spectrum. In this paper, we address the basic theoretical tools needed to predict, essentially ab initio, CW-ESR spectra observables according to the stochastic Liouville equation (SLE) approach, combined with quantum mechanical and hybrid methods for the accurate and efficient computation of structural, spectroscopic and magnetic properties of molecular systems. We shall discuss, on one hand, the quantum mechanical calculation of magnetic observables, via density functional theory (DFT), time-dependent DFT (TD-DFT) and application of the polarizable continuum model (PCM) for the description of environmental effects, including anisotropic environments and systems where different regions are characterized by different dielectric constants. One the other hand, the explicit evaluation of dynamical effects will be discussed based on the numerically exact treatment of the SLE in the presence of several relaxation processes, which has been proven to be a challenging task.

  18. The CW domain, a structural module shared amongst vertebrates, vertebrate-infecting parasites and higher plants.

    Science.gov (United States)

    Perry, Jason; Zhao, Yunde

    2003-11-01

    A previously undetected domain, named CW for its conserved cysteine and tryptophan residues, appears to be a four-cysteine zinc-finger motif found exclusively in vertebrates, vertebrate-infecting parasites and higher plants. Of the twelve distinct nuclear protein families that comprise the CW domain-containing superfamily, only the microrchida (MORC) family has begun to be characterized. However, several families contain other domains suggesting a relationship between the CW domain and either chromatin methylation status or early embryonic development.

  19. Optimal Signal Processing of Frequency-Stepped CW Radar Data

    Science.gov (United States)

    Ybarra, Gary A.; Wu, Shawkang M.; Bilbro, Griff L.; Ardalan, Sasan H.; Hearn, Chase P.; Neece, Robert T.

    1995-01-01

    An optimal signal processing algorithm is derived for estimating the time delay and amplitude of each scatterer reflection using a frequency-stepped CW system. The channel is assumed to be composed of abrupt changes in the reflection coefficient profile. The optimization technique is intended to maximize the target range resolution achievable from any set of frequency-stepped CW radar measurements made in such an environment. The algorithm is composed of an iterative two-step procedure. First, the amplitudes of the echoes are optimized by solving an overdetermined least squares set of equations. Then, a nonlinear objective function is scanned in an organized fashion to find its global minimum. The result is a set of echo strengths and time delay estimates. Although this paper addresses the specific problem of resolving the time delay between the first two echoes, the derivation is general in the number of echoes. Performance of the optimization approach is illustrated using measured data obtained from an HP-X510 network analyzer. It is demonstrated that the optimization approach offers a significant resolution enhancement over the standard processing approach that employs an IFFT. Degradation in the performance of the algorithm due to suboptimal model order selection and the effects of additive white Gaussion noise are addressed.

  20. Model-based characterisation of growth performance and l-lactic acid production with high optical purity by thermophilic Bacillus coagulans in a lignin-supplemented mixed substrate medium.

    Science.gov (United States)

    Glaser, Robert; Venus, Joachim

    2017-07-25

    Three Bacillus coagulans strains were characterised in terms of their ability to grow in lignin-containing fermentation media and to consume the lignocellulose-related sugars glucose, xylose, and arabinose. An optical-density high-throughput screening was used for precharacterisation by means of different mathematical models for comparison (Logistic, Gompertz, Baranyi, Richards & Stannard, and Schnute). The growth response was characterised by the maximum growth rate and lag time. For a comparison of the screening and fermentation results, an unstructured mathematical model was proposed to characterise the lactate production, bacterial growth and substrate consumption. The growth model was then applied to fermentation procedures using wheat straw hydrolysates. The results indicated that the unstructured growth model can be used to evaluate lactate producing fermentation. Under the experimental fermentation conditions, one strain showed the ability to tolerate a high lignin concentration (2.5g/L) but lacked the capacity for sufficient pentose uptake. The lactate yield of the strains that were able to consume all sugar fractions of glucose, xylose and arabinose was ∼83.4%. A photometric measurement at 280nm revealed a dynamic change in alkali-lignin concentrations during lactate producing fermentation. A test of decolourisation of vanillin, ferulic acid, and alkali-lignin samples also showed the decolourisation performance of the B. coagulans strains under study. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  1. Eu2+-doped Ba2GaB4O9Cl blue-emitting phosphor with high color purity for near-UV-pumped white light-emitting diodes

    Science.gov (United States)

    Gao, Zhiwen; Deng, Huajuan; Xue, Na; Jeong, Jung Hyun; Yu, Ruijin

    2018-01-01

    Eu2+-doped borate fluoride Ba2GaB4O9Cl was synthesized by the conventional high-temperature solid-state reaction. The crystal structure and luminescence properties of the phosphors, as well as their thermal luminescence quenching capabilities and CIE chromaticity coordinates were systematically investigated. Under the excitation at 340 nm, the phosphor exhibited an asymmetric broad-band blue emission with a peak at 445 nm, which is ascribed to the 4f-5d transition of Eu2+. It was further proved that energy transfer among the nearest neighbor ions is the major mechanism for concentration quenching of Eu2+ in Ba2-xGaB4O9Cl:xEu2+ phosphors. The luminescence quenching temperature is 432 K. The CIE color coordinates are very close to those of BaMgAl10O17:Eu2+ (BAM). All the properties indicated that the blue-emitting Ba2GaB4O9Cl:Eu2+ phosphor has potential application in white LEDs.

  2. Operation of a sub-terahertz CW gyrotron with an extremely low voltage

    Science.gov (United States)

    Bratman, V. L.; Fedotov, A. E.; Fokin, A. P.; Glyavin, M. Yu.; Manuilov, V. N.; Osharin, I. V.

    2017-11-01

    Decreasing the operating voltage for medium-power sub-terahertz gyrotrons aimed at industrial and scientific applications is highly attractive, since it allows size and cost reduction of the tubes and power supply units. In this paper, we examine such an opportunity both numerically and experimentally for the fundamental cyclotron resonance operation of an existing gyrotron initially designed for operation at the second cyclotron harmonic with a relatively high voltage. Simulations predict that output power higher than 10 W can be produced at the fundamental harmonic at voltages less than 2 kV. To form a low-voltage helical electron beam with a sufficiently large pitch-factor, a positive voltage was applied to the first anode of the gyrotron three-electrode magnetron-injection gun with a negative voltage at the cathode. CW gyrotron operation at voltages down to 1.5 kV has been demonstrated at a frequency about of 256 GHz.

  3. Radiolabelling, quality control and radiochemical purity assessment of the Octreotide analogue {sup 68}Ga DOTA NOC

    Energy Technology Data Exchange (ETDEWEB)

    Di Pierro, D.; Rizzello, A. [PET Radiopharmacy-Nuclear Medicine, Azienda Ospedaliero, Universitaria di Bologna, S. Orsolo-Malpighi Hospital, Via Massarenti 9, 40318 Bologna (Italy); Cicoria, G. [Medical Physics, Azienda Ospedaliero, Universitaria di Bologna, S. Orsolo-Malpighi Hospital, Via Massarenti 9, 40318 Bologna (Italy); Lodi, F. [PET Radiopharmacy-Nuclear Medicine, Azienda Ospedaliero, Universitaria di Bologna, S. Orsolo-Malpighi Hospital, Via Massarenti 9, 40318 Bologna (Italy); Marengo, M.; Pancaldi, D. [Medical Physics, Azienda Ospedaliero, Universitaria di Bologna, S. Orsolo-Malpighi Hospital, Via Massarenti 9, 40318 Bologna (Italy); Trespidi, S. [PET Radiopharmacy-Nuclear Medicine, Azienda Ospedaliero, Universitaria di Bologna, S. Orsolo-Malpighi Hospital, Via Massarenti 9, 40318 Bologna (Italy); Boschi, S. [PET Radiopharmacy-Nuclear Medicine, Azienda Ospedaliero, Universitaria di Bologna, S. Orsolo-Malpighi Hospital, Via Massarenti 9, 40318 Bologna (Italy)], E-mail: stefano.boschi@aosp.bo.it

    2008-08-15

    Somatostatin receptors 1-5 are over expressed in neuroendocrine tumours (NETs). {sup 68}Ga-labelled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-Nal3-Octreotide (DOTA NOC), a recent synthesized somatostatin analogue, shows high affinity for those receptors. Herein, modifications of a commercial module for the labelling of DOTA NOC with {sup 68}Ga, as well as the assessment of time course of the radiochemical purity variation are described. The evaluation of radiochemical stability was done by two different chromatographic methods: reversed-phase radio HPLC and fast TLC analysis. Labelled compound has been found radiochemically stable within 3 h from the end of labelling (EOL) and radiochemical purity was always higher than 99%. After 73 labelling sessions the system showed great reproducibility and high radiochemical yield.

  4. Radiolabelling, quality control and radiochemical purity assessment of the Octreotide analogue 68Ga DOTA NOC.

    Science.gov (United States)

    Di Pierro, D; Rizzello, A; Cicoria, G; Lodi, F; Marengo, M; Pancaldi, D; Trespidi, S; Boschi, S

    2008-08-01

    Somatostatin receptors 1-5 are over expressed in neuroendocrine tumours (NETs). 68Ga-labelled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-Nal3-Octreotide (DOTA NOC), a recent synthesized somatostatin analogue, shows high affinity for those receptors. Herein, modifications of a commercial module for the labelling of DOTA NOC with 68Ga, as well as the assessment of time course of the radiochemical purity variation are described. The evaluation of radiochemical stability was done by two different chromatographic methods: reversed-phase radio HPLC and fast TLC analysis. Labelled compound has been found radiochemically stable within 3h from the end of labelling (EOL) and radiochemical purity was always higher than 99%. After 73 labelling sessions the system showed great reproducibility and high radiochemical yield.

  5. A Purity Monitoring System for the H1 Liquid Argon Calorimeter

    CERN Document Server

    Barrelet, E

    2002-01-01

    The ionization probes used for monitoring the liquid argon purity in the H1 calorimeter are described and results of their operation in tests at CERN and during the period 1992 to the end of 1998 at HERA are given. The high sensitivity of the charge measurements leads to refined charge collection models, and to the observation of a variation of the ionization yield of our electron sources with temperature.

  6. Intracavity-Pumped Raman Laser Action in a Mid-IR, Continuous-Wave (cw) MgO:PPLN Optical Parametric Oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Okishev, A.V.; Zuegel, J.D.

    2006-12-13

    Intracavity-pumped Raman laser action in a fiber-laser–pumped, single-resonant, continuous-wave (cw) MgO:PPLN optical parametric oscillator with a high-Q linear resonator has been observed for the first time to our knowledge. Experimental results of this phenomenon investigation will be discussed.

  7. Intracavity-pumped Raman laser action in a mid IR, continuous-wave (cw) MgO:PPLN optical parametric oscillator.

    Science.gov (United States)

    Okishev, Andrey V; Zuegel, Jonathan D

    2006-12-11

    Intracavity-pumped Raman laser action in a fiber-laser-pumped, single-resonant, continuous-wave (cw) MgO:PPLN optical parametric oscillator with a high-Q linear resonator has been observed for the first time to our knowledge. Experimental results of this phenomenon investigation will be discussed.

  8. Characteristics of the evolution of a plasma generated by radiation from CW and repetitively pulsed CO2 lasers in different gases

    Science.gov (United States)

    Kanevskii, M. F.; Stepanova, M. A.

    1990-06-01

    The interaction between high-power CW and repetitively pulsed CO2 laser radiation and a low-threshold optical-breakdown plasma near a metal surface is investigated. The characteristics of the breakdown plasma are examined as functions of the experimental conditions. A qualitative analysis of the results obtained was performed using a simple one-dimensional model for laser combustion waves.

  9. Apsidal Motion Study of Close Binary System CW Cephei

    Directory of Open Access Journals (Sweden)

    Wonyong Han

    2015-12-01

    Full Text Available New observations for the times of minimum lights of a well-known apsidal motion star CW Cephei were made using a 0.6 m wide field telescope at Jincheon station of Chungbuk National University Observatory, Korea during the 2015 observational season. We determined new times of minimum lights from these observations and analyzed O-C diagrams together with collected times of minima to study both the apsidal motion and the Light Time Effect (LTE suggested in the system. The new periods of the apsidal motion and the LTE were calculated as 46.6 and 39.3 years, respectively, which were similar but improved accuracy than earlier ones investigated by Han et al. (2002, Erdem et al. (2004 and Wolf et al. (2006.

  10. CHELATING LIGANDS: ENHANCERS OF QUALITY AND PURITY ...

    African Journals Online (AJOL)

    Nwokem et al.

    ABSTRACT. The quality of biogas depends largely on the percentage of methane and hydrogen sulphide gas present. High concentration of hydrogen sulphide results in low quality biogas. This work employed the use of chelating ligands in scrubbing hydrogen sulphide gas while improving the yield of methane gas.

  11. Effect of Nd 3+concentration on CW and pulsed performance of fiber ...

    Indian Academy of Sciences (India)

    The effect of Nd3+ concentration on the CW and Q-switched laser performances at 1064 nm from Nd : YVO4 has been studied under diode laser pumping in identical laser configuration. The Nd3+ concentrations used were 1, 2 and 3 at. % in YVO4 crystals. Under the CW operations we have compared the thermal lensing ...

  12. A new approach to model CW CO2 laser using rate equations

    Indian Academy of Sciences (India)

    2016-11-11

    Nov 11, 2016 ... assumption of the different modes to be in thermal equilibrium. Moore et al [8] and Tychinskii [9] were the first to independently propose these rate equations for the CW CO2 laser. Tyte [10] used such a model to calculate population densities of the vibration lev- els of a CW CO2 laser, in the non-lasing case.

  13. Data of evolutionary structure change: 1VLCA-1CW1A [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1VLCA-1CW1A 1VLC 1CW1 A A ------------------------HMKIAVLPGDGIGPEVVREALKVLEVV-EKKT...1VLC A 1VLCA EKKTG--KTFEK...1VLC A 1VLCA DRFGE--PLPEE...1VLC A 1VLCA IAKNR-RKKVT ...1VLC A 1VLCA KANVL-YSSML

  14. Study of important parameters on the irradiation of {sup 124}Xe, to improve the production of {sup 123}I with high purity using the Cyclone-30 cyclotron at IPEN-CNEN/SP; Estudo de parametros relevantes na irradiacao de {sup 124}Xe, visando a otimizacao na obtencao de {sup 123}I ultra puro no ciclotron Cyclone-30 do IPEN-CNEN/SP

    Energy Technology Data Exchange (ETDEWEB)

    Sumiya, Luiz Carlos do Amaral

    2006-07-01

    The development of diagnosis equipment and therapy procedures in nuclear medicine depends on the availability of commercial radioisotopes. IPEN is the most important institution that provides radioisotopes for national market. In order to achieve this function, IPEN had invested in the acquisition of a 30 MeV Cyclone-30 cyclotron to produce mainly {sup 18}F, {sup 67}Ga, {sup 201}Tl and {sup 123}I. The {sup 123}I production is the aim of the present work. With the {sup 123}I routine production data obtained by proton irradiation of Xe targets with an enrichment greater than 99.8%, it was possible to identify the important parameters that have direct influence on the production yield of high purity degree {sup 123}I. Even though the methodology for the commercial production of {sup 123}I, there are an scarcity of operational parameters data for this task. In this work the evaluated parameters were: {sup 124}Xe pressure, proton beam quality, irradiation time, operational temperature of the irradiation system under irradiation, waiting time to obtain {sup 123}I, temperature of washing solution and the impact of the internal Ni coating in the target. With the obtained results it was possible to modify the operational conditions for routine production and increasing the efficiency in about 30%. (author)

  15. Multielement trace determination in high purity advanced ceramics ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. In the field of advanced ceramics two CRMs were developed in the last few years by the Federal. Institute for Materials Research and Testing, one for silicon nitride and one for silicon carbide. Besides their application by industry they are appropriate to be used for the validation of special methods used for trace de-.

  16. A new {beta}-diketone complex with high color purity

    Energy Technology Data Exchange (ETDEWEB)

    Adati, R.D. [Unesp, Sao Paulo State University, Instituto de Quimica C.P. 355, 14801-970 Araraquara-SP (Brazil); Lima, S.A.M. [Unesp, Sao Paulo State University, Instituto de Quimica C.P. 355, 14801-970 Araraquara-SP (Brazil); Davolos, M.R. [Unesp, Sao Paulo State University, Instituto de Quimica C.P. 355, 14801-970 Araraquara-SP (Brazil)]. E-mail: davolos@iq.unesp.br; Jafelicci, M. [Unesp, Sao Paulo State University, Instituto de Quimica C.P. 355, 14801-970 Araraquara-SP (Brazil)

    2006-07-20

    In this work a new europium (III) complex with the following formula NH{sub 4}[Eu(bmdm){sub 4}] was synthesized and characterized. The bmdm (butyl methoxy-dibenzoyl-methane) is a {beta}-diketone molecule used as UV radiation absorber in sunscreen formulations. Coordination of this ligand to the Eu{sup 3+} ion was confirmed by FT-IR, while the Raman spectrum suggests the presence of NH{sub 4} {sup +} ions. The photoluminescence spectra present narrow lines arising from f-f intra-configurational transitions {sup 5}D{sub 0}-{sup 7}F{sub 0,1,2,3,4}, dominated by the hypersensitive {sup 5}D{sub 0}-{sup 7}F{sub 2} transition. In the spectrum recorded at 77 K, all transitions split into 2J + 1 lines suggesting that there is just one symmetry site around Eu{sup 3+} ion. This symmetry is not centrosymmetric. The calculated intensity parameters are {omega} {sub 2} = 30.5 x 10{sup -20} cm{sup 2} and {omega} {sub 4} = 5.91 x 10{sup -20} cm{sup 2} for this complex. The CIE chromaticity coordinates (x = 0.67 and y = 0.32) show a dominant wavelength of 615 nm. The color gamut achieved by this complex is a 100% in the CIE color space.

  17. High purity materials as targets for radioisotope production: Needs ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Radionuclides have become powerful and indispensable tools in many endeavours of human activities, most importantly in medicine, industry, biology and agriculture, apart from R&D activities. Ready availability of radionuclides in suitable radiochemical form, its facile detection and elegant tracer concepts are ...

  18. The designer's guide to high-purity oscillators

    CERN Document Server

    Hegazi, Emad; Abidi, Asad

    2006-01-01

    Presents a comprehensive theory and design methodology for the design of LC CMOS oscillators used in every wireless transmission system. This book introduces the subject of phase noise and oscillators from the very first principles, and attempts to carry the reader to a very intuitive circuit-driven theory of phase noise in LC oscillators.

  19. Plasma Spray Synthesis of High Purity Boron Nitride Nanotubes Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Compared with carbon nanotubes, BNNT's possess better mechanical properties and are thermally stable to much higher temperatures. The potential benefits of...

  20. Extractive process for preparing high purity magnesium chloride hexahydrate

    Directory of Open Access Journals (Sweden)

    Fezei Radouanne

    2012-01-01

    Full Text Available This paper refers a method for the preparation of magnesium chloride hexahydrate (bischofite from Sebkha el Melah of Zarzis Tunisian natural brine. It is a five-stage process essentially based on crystallization by isothermal evaporation and chemical precipitation. The two first steps were dedicated to the crystallization of sodium chloride and potassiummagnesium double salts, respectively. Then, the resulting liquor was desulfated using calcium chloride solution. After that another isothermal evaporation stage was implemented in order to eliminate potassium ions in the form of carnallite, KCl.MgCl2.6H2O. At the end of this step, the recovered solution primarily composed of magnesium and chloride ions was treated by dioxan in order to precipitate magnesium chloride as MgCl2.6H2O.C4H8O2. This compound dried at constant temperature of 100°C gave good quality magnesium chloride hexahydrate. Besides this salt, the various by-products obtained from the different treatment stages are also useful.

  1. Growth of high purity semiconductor epitaxial layers by liquid phase ...

    Indian Academy of Sciences (India)

    Unknown

    at 780°C for 20 h under Pd-diffused hydrogen obtained from a hydrogen gas generator. Growth was done on semi-insulating or n+ GaAs substrates, oriented along the. direction, which were degreased and etched in. 5 H2SO4 + 1 H2O2 + 1 H2O solution, followed by mild etch in 1% Br2 in methanol. Layers up to 8 ...

  2. Analytical challenges in characterization of high purity materials

    Indian Academy of Sciences (India)

    Unknown

    about chemical systems in order to take the most appro- priate decisions for problem solving. The fundamental analytical requirements for realizing the desired and ac- ceptable information from a chemical analysis are repre- sentative nature of the sample, precision, accuracy, selectivity and sensitivity. These decide, to a ...

  3. High purity tellurium production using dry refining processes

    Indian Academy of Sciences (India)

    Unknown

    semi-circular of 560 mm long was placed in a thoroughly etched and cleaned quartz boat and inserted into a 44 mm dia and 1600 mm long quartz tube and evacuated for at- least 4 to 5 h under dry hydrogen gas flow of ~ 80 CCM. Microprocessor controlled stepper motor driven quadru- ple zone refiner (QZR) with the heater ...

  4. Purity assessment of ginsenoside Rg1 using quantitative (1)H nuclear magnetic resonance.

    Science.gov (United States)

    Huang, Bao-Ming; Xiao, Sheng-Yuan; Chen, Ting-Bo; Xie, Ying; Luo, Pei; Liu, Liang; Zhou, Hua

    2017-05-30

    Ginseng herbs comprise a group of the most popular herbs, including Panax ginseng, P. notoginseng and P. quinquefolius (Family Araliaceae), which are used as traditional Chinese medicine (TCM) and are some of the best-selling natural products in the world. The accurate quantification of ginsenoside Rg1 is one of the major aspects of its quality control. However, the purity of the commercial Rg1 chemical reference substance (CRS) is often measured with high-performance chromatography coupled with an ultraviolet detector (HPLC-UV), which is a selective detector with unequal responses to different compounds; thus, this detector introduces probable error to purity assessments. In the present study, quantitative nuclear magnetic resonance (qNMR), due to its absolute quantification ability, was applied to accurately assess the purity of Rg1 CRS. Phenylmethyl phthalate was used as the internal standard (IS) to calibrate the purity of Rg1 CRS. The proton signal of Rg1 CRS in methanol-d4 at 4.37ppm was selected to avoid interfering signals, enabling accurate quantitative analysis. The relaxation delay, number of scans, and NMR windowing were optimized for data acquisition. For post-processing, the Lorentz/Gauss deconvolution method was employed to increase the signal accuracy by separating the impurities and noise in the integrated region of the quantitative proton. The method validation showed that the developed method has acceptable sensitivity, linearity, precision, and accuracy. The purity of the commercial Rg1 CRS examined with the method developed in this research was 90.34±0.21%, which was obviously lower than that reported by the manufacturer (>98.0%, HPLC-UV). The cross-method validation shows that the commonly used HPLC-UV, HPLC-ELSD (evaporative light scattering detector) and even LC-MS (mass spectrometry) methods provide significantly higher purity values of Rg1 CRS compared with the qNMR method, and the accuracy of these LC-based methods largely depend on the

  5. Capillary electrophoresis-based assessment of nanobody affinity and purity

    NARCIS (Netherlands)

    Haselberg, Rob; Oliveira, Sabrina; van der Meel, Roy; Somsen, Govert W; de Jong, Gerhardus J

    2014-01-01

    Drug purity and affinity are essential attributes during development and production of therapeutic proteins. In this work, capillary electrophoresis (CE) was used to determine both the affinity and composition of the biotechnologically produced "nanobody" EGa1, the binding fragment of a

  6. Powder metallurgical processing and metal purity: A case for ...

    Indian Academy of Sciences (India)

    Unknown

    powder metallurgy route, because of many associated advantages (Upadhyaya 1997). The purity of the starting metal or ceramic powder is of significance in controlling the microstructure/properties/processing and performance of such products. The major methods of production of metal powders are: chemical, physical and ...

  7. Group-based discrimination in judgments of moral purity-related behaviors: experimental and archival evidence.

    Science.gov (United States)

    Masicampo, E J; Barth, Maria; Ambady, Nalini

    2014-12-01

    Knowledge of individuals' group membership can alter moral judgments of their behavior. We found that such moral judgments were amplified when judgers learned that a person belonged to a group shown to elicit disgust in others. When a person was labeled as obese, a hippie, or "trailer trash," people judged that person's behavior differently than when such descriptors were omitted: Virtuous behaviors were more highly praised, and moral violations were more severely criticized. Such group-based discrimination in moral judgment was specific to the domain of moral purity. Members of disgust-eliciting groups but not members of other minorities were the target of harsh judgments for purity violations (e.g., lewd behavior) but not for other violations (e.g., refusing to help others). The same pattern held true for virtuous behaviors, so that members of disgust-eliciting groups were more highly praised than others but only in the purity domain. Furthermore, group-based discrimination was mediated by feelings of disgust toward the target group but not by other emotions. Last, analysis of New York Police Department officers' encounters with suspected criminals revealed a similar pattern to that found in laboratory experiments. Police officers were increasingly likely to make an arrest or issue a summons as body mass index increased (i.e., as obesity rose) among people suspected of purity crimes (e.g., prostitution) but not of other crimes (e.g., burglary). Thus, moral judgments in the lab and in the real world exhibit patterns of discrimination that are both group and behavior specific. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  8. Alternative methods for radiochemical purity testing in radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Ideli M. de; Martins, Patricia de A.; Silva, Jose L. da; Ramos, Marcelo P.S.; Lima, Jose A.S.; Pujatti, Priscilla B.; Fukumori, Neuza T.O.; Matsuda, Margareth M.N. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The radiochemical purity (RCP) testing is as prerequisite for radiopharmaceuticals before the administration to the patient. Because time is critical in nuclear medicine, emphasis should be given to the radiochemical quality control procedures, in order to obtain the maximum amount of information in the minimum period of time. Radiochemical purity is defined as the proportion of the total radioactivity in the product that is present in the specified chemical form. Usually, the RCP is evaluated by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). The most widely used technique for RCP determination in radiopharmaceutical preparations is TLC-aluminium (TLC-Al), instant thin layer chromatography-silica gel (ITLC-SG) and paper chromatography (PC). Indeed, many of the pharmacopeial methods use these techniques. The purpose of the present study was to evaluate different chromatographic systems for RCP in {sup 67}Ga-Citrate, {sup 111}In-Octreotide, {sup 177}Lu-DOTATATE and {sup 153}Sm-HA. PC was performed with 3MM/1MM Whatman plates, TCL-Al sheets from Merck and ITLC-SG sheets from Pall Corporation and Varian Inc. The mobile phases were 0.16 mol.L{sup -1} sodium acetate, 0.9% sodium chloride (p/v), 0.1 mol.L{sup -1} sodium citrate buffer, 0.2 mol.L{sup -1} EDTA, methanol:0.4 mol.L{sup -1} ammonium acetate (1:1) mixture, and pyridine:ethanol:water (1:2:4) mixture. The samples were placed on plates in triplicate and immediately put into pre-saturated chambers with the mobile phase. After the chromatographic separation, the plates were dried and cut into 7, 10 or 12 segments and each one was separately measured in a gamma counter during 0.20 minutes (set on the radioisotope window). The results in the gamma counter were expressed in counts per minute (cpm). The chromatographic systems for {sup 177}Lu-DOTATATE and {sup 153}Sm-HA gave the best performances in 0.1 mol L{sup -1} sodium citrate buffer/TLC-Al and 0.9% (p/v) sodium chloride

  9. Advancing IM-CW Lidar Modulation Techniques for ASCENDS CO2 Column Measurements from Space

    Science.gov (United States)

    Campbell, J. F.; Lin, B.; Nehrir, A. R.; Harrison, F. W.; Chen, S.; Obland, M. D.

    2013-12-01

    Global atmospheric carbon dioxide (CO2) measurements through the Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) decadal survey recommended space mission are critical for improving our understanding of CO2 sources and sinks. IM-CW (Intensity Modulated Continuous Wave) lidar techniques are investigated as a means of facilitating CO2 measurements from space to meet the ASCENDS science requirements. In previous laboratory and flight experiments we have successfully used linear swept frequency modulation to discriminate surface lidar returns from intermediate aerosol and cloud contamination. Furthermore, high accuracy and precision ranging to the surface as well as to the top of intermediate clouds, which is a requirement for the inversion of the CO2 column mixing ratio from the instrument optical depth measurements, has been demonstrated with the linear swept frequency modulation technique. We are concurrently investigating advanced techniques to help improve the auto-correlation properties of the transmitted waveform implemented through physical hardware to make cloud rejection more robust in special restricted scenarios. Several different modulation techniques are compared including orthogonal linear swept, orthogonal non-linear swept, time shifted PN, sine wave modulated PN, and sine wave pulsed PN. Different PN code techniques are presented that are appropriate for different types of lidar hardware, including our current ASCENDS IM-CW concept space hardware. These techniques have excellent auto-correlation properties without sidelobes while possessing a finite bandwidth (by way of a new cyclic digital filter), which will reduce bias error in the presence of multiple scatterers. Our analyses show that the studied modulation techniques can increase the accuracy of CO2 column measurements from space.

  10. Universal informative CpG sites for inferring tumor purity from DNA methylation microarray data.

    Science.gov (United States)

    Dou, Haixia; Fang, Yun; Zheng, Xiaoqi

    2017-12-28

    Tumor purity is an intrinsic property of tumor samples and potentially has severe impact on many types of data analysis. We have previously developed a statistical method, InfiniumPurify, which could infer purity of a tumor sample given its tumor type (available in TCGA) or a set of informative CpG (iDMC) sites. However, in many clinical practices, researchers may focus on a specific type of tumor samples that is not included in TCGA, and samples which are too few to identify reliable iDMCs. This greatly restricts the application of InfiniumPurify in cancer research. In this paper, we proposed an updated version of InfiniumPurify (termed as uiInfiniumPurify) through identifying a universal set of iDMCs (uiDMCs) and redesigning the algorithm to determine hyper- and hypo-methylation status of each uiDMC. Through the application, we estimated tumor purities of 8830 tumor samples from TCGA. Result shows that our estimates are highly consistent with those by other available methods. Consequently, the updated uiInfiniumPurify, can be applied to a single sample (or a few samples) of interest whose tumor type is not included in TCGA. This characteristic will greatly broaden the application of uiInfiniumPurify in cancer research.

  11. Capillary gel electrophoresis for the quantification and purity determination of recombinant proteins in inclusion bodies.

    Science.gov (United States)

    Espinosa-de la Garza, Carlos E; Perdomo-Abúndez, Francisco C; Campos-García, Víctor R; Pérez, Néstor O; Flores-Ortiz, Luis F; Medina-Rivero, Emilio

    2013-09-01

    In this work, a high-resolution CGE method for quantification and purity determination of recombinant proteins was developed, involving a single-component inclusion bodies (IBs) solubilization solution. Different recombinant proteins expressed as IBs were used to show method capabilities, using recombinant interferon-β 1b as the model protein for method validation. Method linearity was verified in the range from 0.05 to 0.40 mg/mL and a determination coefficient (r(2) ) of 0.99 was obtained. The LOQs and LODs were 0.018 and 0.006 mg/mL, respectively. RSD for protein content repeatability test was 2.29%. In addition, RSD for protein purity repeatability test was 4.24%. Method accuracy was higher than 90%. Specificity was confirmed, as the method was able to separate recombinant interferon-β 1b monomer from other aggregates and impurities. Sample content and purity was demonstrated to be stable for up to 48 h. Overall, this method is suitable for the analysis of recombinant proteins in IBs according to the attributes established on the International Conference for Harmonization guidelines. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Identification of a novel HLA-C allele, Cw*0406, in a Singapore Malay.

    Science.gov (United States)

    Ren, E C; Haniff, F; Loh, M T; Chan, S H; Petersdorf, E; Hansen, J

    1999-02-01

    A novel allele, C*0406, has been identified and is characterised by a single nucleotide substitution at position 196 of exon 3 when compared with its closest related allele, C*0403. The latter is found in 4/69 Chinese and 7/80 Malays while Cw*0406 was found in only one Malay individual within the study populations. The data suggest that Cw*0406 may have arisen as a relatively recent genetic event either by gene conversion or as a simple point mutation variant of Cw*0403.

  13. Design and operation of 140 GHz gyrotron oscillators for power levels up to 1 MW CW

    Energy Technology Data Exchange (ETDEWEB)

    Jory, H.; Bier, R.; Craig, L.J.; Felch, K.; Ives, L.; Lopez, N.; Spang, S.

    1986-12-01

    Varian has designed and tested 140 GHz gyrotron oscillators that have generated output powers of 100 kW CW and 200 kW for 1 ms pulses. Upcoming tubes will be designed to operate at power levels of 200 kW CW and ultimately up to 1 MW CW. The important design considerations which are addressed in the higher power tubes include the design of the electron gun, interaction circuit, and output window. These issues will be discussed and the results of the earlier 140 GHz gyrotron work at Varian will be summarized.

  14. Photoelectric Observations of the Close Eclipsing Binary System CW Cephei

    Directory of Open Access Journals (Sweden)

    Won Yong Han

    1984-09-01

    Full Text Available Photoelectric observations of the close eclipsing binary system CW Cep, which is well known of its apsidal motion, were made on 20 nights during August and November in 1983 using two 61cm reflectors at the Sobaeksan Observing Station of Korean National Astronomical Observatory and Ilsan Observing Station of Yonsei University Observatory. Standardized new light curves in UBV system are presented with a total of 1,422 individual observations. For the corrections of regional and instrumental differences, same standard stars were observed at the two observatories. Four new times of minimum light were determined with the method of Kwee and van Woerden (1956. With all of the collected times of minima, apsidal motion of this system was checked, but the O-C values calculated by the light elements of Nha (1975 and S derhjelm (1976 did not coincide well with new times of minima. New light elements which satisfy most times of minima better, and are deduced the apsidal period derived by the new light elements turns out to be 43 years, somewhat longer than those of values previously known.

  15. Characterization of low-purity clays for geopolymer binder formulation

    Science.gov (United States)

    Mostafa, Nasser Y.; Mohsen, Q.; El-maghraby, A.

    2014-06-01

    The production of geopolymer binders from low-purity clays was investigated. Three low-purity clays were calcined at 750°C for 4 h. The calcined clays were chemically activated by the alkaline solutions of NaOH and Na2SiO3. The compressive strength was measured as a function of curing time at room temperature and 85°C. The results were compared with those of a pure kaolin sample. An amorphous aluminosilicate polymer was formed in all binders at both processing temperatures. The results show that, the mechanical properties depend on the type and amount of active aluminum silicates in the starting clay material, the impurities, and the processing temperature.

  16. Electrophoresis for the analysis of heparin purity and quality

    Science.gov (United States)

    Volpi, Nicola; Maccari, Francesca; Suwan, Jiraporn; Linhardt, Robert J.

    2012-01-01

    The adulteration of raw heparin with oversulfated chondroitin sulfate (OSCS) in 2007–2008 produced a global crisis resulting in extensive revisions to the pharmacopeia monographs and prompting the FDA to recommend the development of additional methods for the analysis of heparin purity. As a consequence, a wide variety of innovative analytical approaches have been developed for the quality assurance and purity of unfractionated and low-molecular-weight heparins. This review discusses recent developments in electrophoresis techniques available for the sensitive separation, detection, and partial structural characterization of heparin contaminants. In particular, this review summarizes recent publications on heparin quality and related impurity analysis using electrophoretic separations such as capillary electrophoresis (CE) of intact polysaccharides and hexosamines derived from their acidic hydrolysis, and polyacrylamide gel electrophoresis (PAGE) for the separation of heparin samples without and in the presence of its relatively specific depolymerization process with nitrous acid treatment. PMID:22736353

  17. The Price and Purity of Illicit Drugs: 1981-2007

    Science.gov (United States)

    2008-10-01

    categorizations of marijuana, i.e., domestic, Mexican, Canadian, and hydroponic . Comparisons of the NDIC data to 2005 STRIDE bulk prices for marijuana, which are...discussion of the advantages and challenges of constructing meaningful time series of price and purity estimates based on STRIDE data is presented in...variations across different NDIC categorizations of marijuana, i.e., domestic, Mexican, Canadian, and hydroponic . Comparisons of the NDIC data to 2005

  18. Development of a Time Synchronized CW-Laser Induced Fluorescence Measurement for Quasi-Periodic Oscillatory Plasma Discharges

    Science.gov (United States)

    MacDonald, Natalia; Cappelli, Mark; Hargus, William, Jr.

    2012-10-01

    An advanced CW laser induced fluorescence diagnostic technique, capable of correlating high frequency current fluctuations to the resulting fluorescence excitation lineshapes, has been developed. This presentation describes this so-called ``Sample-Hold'' method of time-synchronization, and provides the steps taken to validate this technique, including simulations and experimental measurements on a 60 Hz Xe lamp discharge. Initial results for time-synchronized velocity measurements on the quasi-periodic oscillatory mode of a magnetic cusped plasma accelerator are also presented. These results show that the positions of the ionization and peak acceleration regions in the device vary over the course of a discharge current oscillation.

  19. HLA-Cw*04 allele associated with nevirapine-induced rash in HIV-infected Thai patients

    Directory of Open Access Journals (Sweden)

    Tunthanathip Preecha

    2009-10-01

    Full Text Available Abstract Background A high incidence of rash has been reported in HIV-1 patients who received the anti-retroviral drug nevirapine. In addition, several studies have suggested that polymorphisms of human leukocyte antigen (HLA genes may play important roles in nevirapine-induced rash. The aim of the present study was to evaluate the effects of different HLA-C alleles on rash associated with nevirapine in patients who started highly active anti-retroviral therapy (HAART containing nevirapine in Thailand. Results A case-control study was carried out involving HIV-1 patients under treatment at Bamrasnaradura Infectious Diseases Institute, Nonthaburi, Thailand between March 2007 and March 2008. The study included all HIV/AIDS patients being treated with nevirapine-containing regimens. The study population comprised 287 HIV/AIDS patients of whom 248 were nevirapine-tolerant and 39 developed rash after nevirapine treatment. From the nevirapine-tolerant patients, 60 were selected as the control group on the basis of age, sex, and therapy history matched for nevirapine-induced rash cases. We observed significantly more HLA-Cw*04 alleles in nevirapine-induced rash cases than in nevirapine-tolerant group, with frequencies of 20.51% and 7.50%, respectively (P = 0.009. There were no significant differences between the rash and tolerant groups for other HLA-C alleles except for HLA-Cw*03 (P = 0.015. Conclusion This study suggests that HLA-Cw*04 is associated with rash in nevirapine treated Thais. Future screening of patients' HLA may reduce the number of nevirapine-induced rash cases, and patients with alleles associated with nevirapine-induced rash should be started on anti-retroviral therapy without nevirapine.

  20. Low threshold, singly-resonant CW OPO pumped by an all-fiber pump source.

    Science.gov (United States)

    Henderson, Angus; Stafford, Ryan

    2006-01-23

    An oscillation threshold of 780mW has been demonstrated in a singly-resonant, continuous-wave optical parametric oscillator (CW SRO) using a fiber-amplified, distributed feedback (DFB) fiber laser as pump source. A linewidth of 1MHz was measured, and the idler frequency was fine-tuned by up to 130GHz by tuning the pump laser. To our knowledge, this is the first example of a single frequency CW SRO pumped by an all-fiber pump source, a reduction in threshold by a factor of three over previous 1- microm-pumped CW SROs, and a reduction by two orders of magnitude in the linewidth of CW SROs pumped by fiber pump sources.

  1. Advances in electronics prompt a fresh look at continuous wave (CW) nuclear magnetic resonance (NMR)

    OpenAIRE

    Newton, MI; Breeds, EA; Morris, RH

    2017-01-01

    Continuous Wave Nuclear Magnetic Resonance (CW-NMR) was a popular method for sample interrogation at the birth of magnetic resonance but has since been overlooked by most in favor of the now more popular pulsed techniques. CW-NMR requires relatively simple electronics although, for most designs, the execution is critical to the successful implementation and sensitivity of the system. For decades there have been reports in the literature from academic groups showing the potential of magnetic r...

  2. Forensic Application of FM-CW and Pulse Radar

    Energy Technology Data Exchange (ETDEWEB)

    S. K. Koppenjan; R. S. Freeland; M. L. Miller; R. E. Yoder

    2003-01-01

    Ground-penetrating radar (GPR) technology has supplied vital assistance in criminal investigations. However, law enforcement personnel desire further developments such that the technology is rapidly deployable, and that it provides both a simple user interface and sophisticated target identification. To assist in the development of target identification algorithms, our efforts involve gathering background GPR data for the various site conditions and circumstances that often typify clandestine burials. For this study, forensic anthropologists established shallow-grave plots at The University of Tennessee Anthropological Research Facility (ARF) that are specific to GPR research. These plots contain donated human cadavers lying in various configurations and depths, surrounded by assorted construction material and backfill debris. We scanned the plots using two GPR technologies: (1) a multi-frequency synthetic-aperture FM-CW radar (200-700 MHz) (GPR-X) developed by the U.S. Department of Energy's (DOE) Special Technologies Laboratory (STL), Bechtel Nevada (Koppenjan et al., 2000), and (2) a commercial pulse radar (SIR-20) manufactured by Geophysical Survey Systems, Inc. (400 and 900 MHz)(GSSI). The sweep-frequency data show the large biological mass decomposing within the torso as encircled ''hot spots.'' The 400-MHz pulse radar exhibit major horizontal reflectors above the body, with shadow reflectors (horizontal multiples) occurring beneath the body at 60 cm depth. The 400-MHz antenna was able to discern the grave walls and folded tarp covering the lower body. Under these moist, clay-rich conditions, the 900-MHz antenna was able to penetrate slightly beyond 30 cm beneath the concrete layer. However, neither system was able to penetrate beyond a one meter depth in the moist, clay-rich soil (fine, mixed, thermic Typic Paleudalf). Example scans from each system are provided, along with a discussion of the survey protocol and general performance.

  3. 7 CFR 201.51b - Purity procedures for coated seed.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Purity procedures for coated seed. 201.51b Section 201... SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Purity Analysis in the Administration of the Act § 201.51b Purity...

  4. Research on quasi-cw and pulse interaction of strong laser radiation with the military technical materials

    Science.gov (United States)

    Rycyk, Antoni; CzyŻ, Krzysztof; Sarzyński, Antoni; Skrzeczanowski, Wojciech; Ostrowski, Roman; Strzelec, Marek; Jach, Karol; Świerczyński, Robert

    2016-12-01

    The paper describes work connected to the investigation of the interaction of strong laser radiation with selected metals, constituting typical materials applied in military technology, like aluminum, copper, brass and titanium. A special laser experimental stand was designed and constructed to achieve this objective. The system consisted of two Nd:YAG lasers working in the regime of free generation (quasi-cw) and another Nd:YAG laser, generating short pre-pulses in the Qswitching regime. During the concurrent operation of both quasi-cw systems it was possible to obtain pulse energies amounting to 10 J in a time period (pulses) of 1 ms. The synchronized, serial operation resulted in energy amounting to 5 J over a time period (pulse) of 2 ms. Variations of the target's surface reflection coefficient, caused by the interaction of short pre-pulses with high power density were determined. The experiments were performed using a standard Nd:YAG laser with amplifiers, generating output pulses whose duration amounted to 10 ns and energy to 1 J, with near Gaussian profile. Laser induced breakdown spectroscopy (LIBS) was used to analyze the emission spectra of targets under the conditions of the interaction of destructive strong and weak as well as long and short excitation laser pulses. A decay of the spectra in the UV range from 200 to around 350 nm was observed when irradiating the target with a long, quasi-cw destructive pulse. Moreover, in the case of an Al target, some AlO molecular spectra appeared, suggesting a chemical reaction of the aluminum atoms with oxygen.

  5. Heat-sink free CW operation of injection microdisk lasers grown on Si substrate with emission wavelength beyond 1.3  μm.

    Science.gov (United States)

    Kryzhanovskaya, Natalia; Moiseev, Eduard; Polubavkina, Yulia; Maximov, Mikhail; Kulagina, Marina; Troshkov, Sergey; Zadiranov, Yury; Guseva, Yulia; Lipovskii, Andrey; Tang, Mingchu; Liao, Mengya; Wu, Jiang; Chen, Siming; Liu, Huiyun; Zhukov, Alexey

    2017-09-01

    High-performance injection microdisk (MD) lasers grown on Si substrate are demonstrated for the first time, to the best of our knowledge. Continuous-wave (CW) lasing in microlasers with diameters from 14 to 30 μm is achieved at room temperature. The minimal threshold current density of 600  A/cm2 (room temperature, CW regime, heatsink-free uncooled operation) is comparable to that of high-quality MD lasers on GaAs substrates. Microlasers on silicon emit in the wavelength range of 1320-1350 nm via the ground state transition of InAs/InGaAs/GaAs quantum dots. The high stability of the lasing wavelength (dλ/dI=0.1  nm/mA) and the low specific thermal resistance of 4×10-3°C×cm2/W are demonstrated.

  6. Impact of metal-induced degradation on the determination of pharmaceutical compound purity and a strategy for mitigation.

    Science.gov (United States)

    Dotterer, Sally K; Forbes, Robert A; Hammill, Cynthia L

    2011-04-05

    Case studies are presented demonstrating how exposure to traces of transition metals such as copper and/or iron during sample preparation or analysis can impact the accuracy of purity analysis of pharmaceuticals. Some compounds, such as phenols and indoles, react with metals in the presence of oxygen to produce metal-induced oxidative decomposition products. Compounds susceptible to metal-induced decomposition can degrade following preparation for purity analysis leading to falsely high impurity results. Our work has shown even metals at levels below 0.1 ppm can negatively impact susceptible compounds. Falsely low results are also possible when the impurities themselves react with metals and degrade prior to analysis. Traces of metals in the HPLC mobile phase can lead to chromatographic artifacts, affecting the reproducibility of purity results. To understand and mitigate the impact of metal induced decomposition, a proactive strategy is presented. The pharmaceutical would first be tested for reactivity with specific transition metals in the sample solvent/diluents and in the HPLC mobile phase. If found to be reactive, alternative sample diluents and/or mobile phases with less reactive solvents or addition of a metal chelator would be explored. If unsuccessful, glassware cleaning or sample solution refrigeration could be investigated. By employing this strategy during method development, robust purity methods would be delivered to the quality control laboratories, preventing future problems from potential sporadic contamination of glassware with metals. Copyright © 2010 Elsevier B.V. All rights reserved.

  7. [Chromatographic determination of radiochemical purity - replacement of ITLC SG].

    Science.gov (United States)

    Wunderlich, G; Herrling, P; Zürn, A; Anders, P; Kotzerke, J

    2010-01-01

    Thin layer chromatography is well established for quality control of radiopharmaceuticals. A convenient and widely used stationary phase are ITLC SG strips. However, the Pall Corporation stopped manufacturing of the silica gel impregnated glass fibre strips (ITLC SG). Material, Methode: As a replacement we tested silicic acid impregnated glass fibre strips from Varian (ITLC SA) and sufficient mobile phases. The chromatography with these strips takes two to three times longer than with ITLC SG, but it is in an acceptable range. Only three mobile phases are necessary to test most of the common in-house made radiopharmaceuticals. The proposed method is suitable for routinely measuring the radiochemical purity of radiophamaceuticals.

  8. Design of a 10 MeV normal conducting CW proton linac based on equidistant multi-gap CH cavities

    Science.gov (United States)

    Li, Zhi-Hui

    2015-09-01

    Continuous wave (CW) high current proton linacs have wide applications as the front end of high power proton machines. The low energy part of such a linac is the most difficult and there is currently no widely accepted solution. Based on the analysis of the focusing properties of the CW low energy proton linac, a 10 MeV low energy normal conducting proton linac based on equidistant seven-gap Cross-bar H-type (CH) cavities is proposed. The linac is composed of ten 7-gap CH cavities and the transverse focusing is maintained by quadrupole doublets located between the cavities. The total length of the linac is less than 6 meters and the average acceleration gradient is about 1.2 MeV/m. The electromagnetic properties of the cavities are investigated by Microwave Studio. At the nominal acceleration gradient the maximum surface electric field in the cavities is less than 1.3 times the Kilpatrick limit, and the Ohmic loss of each cavity is less than 35 kW. Multi-particle beam dynamics simulations are performed with Tracewin code, and the results show that the beam dynamics of the linac are quite stable, the linac has the capability to accelerate up to 30 mA beam with acceptable dynamics behavior. Supported by National Natural Science Foundation of China (11375122, 91126003)

  9. Final report of the key comparison CCQM-K72: Purity of zinc with respect to six defined metallic analytes

    Science.gov (United States)

    Vogl, Jochen; Kipphardt, Heinrich; del Rocío Arvizu Torres, María; Manzano, Judith Velina Lara; Marques Rodrigues, Janaína; Caciano de Sena, Rodrigo; Yim, Yong-Hyeon; Heo, Sung Woo; Zhou, Tao; Turk, Gregory C.; Winchester, Michael; Yu, Lee L.; Miura, Tsutomu; Methven, B.; Sturgeon, Ralph; Jährling, Reinhard; Rienitz, Olaf; Tunç, Murat; Zühtü Can, Süleyman

    2014-01-01

    High purity elements can serve as a realization of the SI unit amount of substance for the specific element. Solutions prepared from high purity metals by applying gravimetric preparation and the concept of molar mass are used as 'calibration' solutions in many fields of analytical chemistry and provide the metrological basis in elemental analysis. Since ideal purity does not exist for real materials, the actual purity of the high purity material must be known with a specified uncertainty. As required uncertainties around 10-4 relative on the purity statement are not accessible in almost all cases by a direct measurement of the element in itself, the indirect approach is followed, where all elements excepting the matrix element itself are measured and their sum is subtracted from the value for ideal purity, which is 1 kg/kg. It was the aim of this comparison to demonstrate the capability of national metrology institutes and designated institutes to determine the purity of pure elements. In order to limit the effort within this comparison, only six metallic impurities (Ag, Al, Cd, Cr, Ni, Tl) in the low mg/kg range are considered in a zinc matrix. It has to be underlined here that the task was to measure the purity of zinc based on the determination of six analytes. The task is not trace analysis of specific analytes in zinc. This subtle distinction defines different measurands. The sample, pure Zn, was cut in pieces of cubic geometry for wet chemical analysis or of pin geometry for GDMS analysis and was sent to the participants. The comparison was run under the auspices of the Inorganic analysis Working Group (IAWG) of the CCQM and was piloted by the BAM Federal Institute for Materials Research and Testing, Berlin, Germany. The majority of the participants applied ICP-MS techniques and only two participants used additionally atomic absorption spectrometry. GDMS was used only by one participant. The observed spreads for the measurement results reported by the

  10. Efficient Low-Voltage Operation of a CW Gyrotron Oscillator at 233 GHz.

    Science.gov (United States)

    Hornstein, Melissa K; Bajaj, Vikram S; Griffin, Robert G; Temkin, Richard J

    2007-02-01

    The gyrotron oscillator is a source of high average power millimeter-wave through terahertz radiation. In this paper, we report low beam power and high-efficiency operation of a tunable gyrotron oscillator at 233 GHz. The low-voltage operating mode provides a path to further miniaturization of the gyrotron through reduction in the size of the electron gun, power supply, collector, and cooling system, which will benefit industrial and scientific applications requiring portability. Detailed studies of low-voltage operation in the TE(2) (,) (3) (,) (1) mode reveal that the mode can be excited with less than 7 W of beam power at 3.5 kV. During CW operation with 3.5-kV beam voltage and 50-mA beam current, the gyrotron generates 12 W of RF power at 233.2 GHz. The EGUN electron optics code describes the low-voltage operation of the electron gun. Using gun-operating parameters derived from EGUN simulations, we show that a linear theory adequately predicts the low experimental starting currents.

  11. A 99 percent purity molecular sieve oxygen generator

    Science.gov (United States)

    Miller, G. W.

    1991-01-01

    Molecular sieve oxygen generating systems (MSOGS) have become the accepted method for the production of breathable oxygen on military aircraft. These systems separate oxygen for aircraft engine bleed air by application of pressure swing adsorption (PSA) technology. Oxygen is concentrated by preferential adsorption in nitrogen in a zeolite molecular sieve. However, the inability of current zeolite molecular sieves to discriminate between oxygen and argon results in an oxygen purity limitations of 93-95 percent (both oxygen and argon concentrate). The goal was to develop a new PSA process capable of exceeding the present oxygen purity limitations. A novel molecular sieve oxygen concentrator was developed which is capable of generating oxygen concentrations of up to 99.7 percent directly from air. The process is comprised of four absorbent beds, two containing a zeolite molecular sieve and two containing a carbon molecular sieve. This new process may find use in aircraft and medical breathing systems, and industrial air separation systems. The commercial potential of the process is currently being evaluated.

  12. Effective Fluorescence Lifetime and Stimulated Emission Cross-Section of Nd/Cr:YAG Ceramics under CW Lamplight Pumping

    Science.gov (United States)

    Saiki, Taku; Motokoshi, Shinji; Imasaki, Kazuo; Fujioka, Kana; Fujita, Hisanori; Nakatsuka, Masahiro; Izawa, Yasukazu; Yamanaka, Chiyoe

    2008-10-01

    Remarkable improvements in the lifetime of the Nd upper level and in the effective stimulated emission cross-section of Nd/Cr:YAG ceramics have been theoretically and experimentally studied. Until recently, it had been thought that the long energy transition time from Cr ions to Nd ions of Nd/Cr:YAG adversely affects laser action, degrading optical-optical conversion efficiency under CW and flash lamp pumping. However, current research showed that high-efficiency energy transition has a positive effect on laser action. The effective lifetime is increased from 0.23 to 1.1 ms and the emission cross-section is effectively increased to three times for that of the conventional Nd:YAG. A small signal gain is significantly improved, and the saturation power density is reduced to 1/10 that of the Nd:YAG for the same pumping power density. A CW laser light generated in a laser diode (LD)-pumped 1064 nm Nd:YAG laser oscillator was amplified, and the measured output power was saturated. The output laser power calculated using theoretical saturation power density was consistent with the experimental results.

  13. Superconducting Cavity Cryomodule Designs for the Next Generation of CW Linacs: Challenges and Options

    Energy Technology Data Exchange (ETDEWEB)

    Nicol, Thomas [Fermilab; Orlov, Yuriy [Fermilab; Peterson, Thomas [Fermilab; Yakovlev, Vyacheslav [Fermilab

    2014-07-01

    The designs of nearly all superconducting RF (SRF) linacs over the last several years, with one notable exception being CEBAF at Jefferson Lab, have assumed pulsed beam operation with relatively low duty factors. These include the XFEL at DESY, the ILC, the original configuration for Project X at Fermilab, as well as several others. Recently proposed projects, on the other hand, including the LCLS-II at SLAC, the newly configured low and medium energy sections for Project X, and FRIB at Michigan State, to name a few, assume continuous wave or CW operation on quite a large scale with ambitious gradients and cavity performance requirements. This has implications in the cavity design as well as in many parts of the overall cryomodule due to higher dynamic heat loads in the cavities themselves and higher heat loads in the input and high-order-mode (HOM) couplers. Piping internal to the cryomodule, the effectiveness of thermal intercepts, the size of integrated heat exchangers, and many other aspects of the overall design are also affected. This paper will describe some of these design considerations as we move toward the next generation of accelerator projects.

  14. Status of the development of the EU 170 GHz/1 MW/CW gyrotron

    Energy Technology Data Exchange (ETDEWEB)

    Pagonakis, Ioannis Gr., E-mail: ioannis.pagonakis@kit.edu [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Albajar, Ferran [The European Joint Undertaking for ITER and The Development of Fusion Energy, Barcelona (Spain); Alberti, Stefano [École Polytechnique Fédérale de Lausanne, Centre de Recherches en Physique des Plasmas (CRPP), Lausanne (Switzerland); Avramidis, Konstantinos [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Bonicelli, Tullio [The European Joint Undertaking for ITER and The Development of Fusion Energy, Barcelona (Spain); Braunmueller, Falk [École Polytechnique Fédérale de Lausanne, Centre de Recherches en Physique des Plasmas (CRPP), Lausanne (Switzerland); Bruschi, Alex [Plasma Physics Institute, National Research Council of Italy, Milano (Italy); Chelis, Ioannis [School of Electrical and Computer Engineering, National Technical University of Athens (Greece); Cismondi, Fabio [The European Joint Undertaking for ITER and The Development of Fusion Energy, Barcelona (Spain); Gantenbein, Gerd [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Hermann, Virgile [Thales Electron Devices (TED), Vélizy-Villacoublay (France); Hesch, Klaus [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Hogge, Jean-Philippe [École Polytechnique Fédérale de Lausanne, Centre de Recherches en Physique des Plasmas (CRPP), Lausanne (Switzerland); Jelonnek, John; Jin, Jianbo; Illy, Stefan [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); Ioannidis, Zisis C. [Faculty of Physics, National and Kapodistrian University of Athens (Greece); Kobarg, Thorsten [Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany); and others

    2015-10-15

    The progress in the development of the European 170 GHz, 1 MW/CW gyrotron for electron cyclotron heating & current drive (ECH&CD) on ITER is reported. A continuous wave (CW) prototype is being manufactured by Thales Electron Devices (TED), France, while a short-pulse (SP) prototype gyrotron is in parallel under manufacture at Karlsruhe Institute of Technology (KIT), with the purpose of validating the design of the CW industrial prototype components. The fabrication of most of the sub-assemblies of the SP prototype has been completed. In a first step, an existing magnetron injection gun (MIG) available at KIT was used. Despite this non-ideal configuration, the experiments provided a validation of the design, substantiated by an excellent agreement with numerical simulations. The tube, operated without a depressed collector, is able to produce more than 1 MW of output power with efficiency in excess of 30%, as expected, and compatible with the ITER requirements.

  15. Supply-side response to declining heroin purity: fentanyl overdose episode in New Jersey.

    Science.gov (United States)

    Hempstead, Katherine; Yildirim, Emel O

    2014-06-01

    The inelastic price demand observations characteristic of illegal drug markets have led to the conclusion that the burden of a negative supply shock would be completely reflected to consumers. This paper argues that the increasing availability of prescription opioids may threaten heroin sellers' profit margin and force them to find alternative methods to compensate buyers in the event of a supply shock. We investigate the 2006 fentanyl overdose episode in New Jersey and argue that the introduction of non-pharmaceutical fentanyl, its spatial distribution, and the timing of overdose deaths may have been related to trends in heroin purity. Using medical examiner data, as well as data from the Drug Enforcement Administration, Office of Diversion Control on retail sales of prescription opioids in a negative binomial specification, we show that month-to-month fluctuations in heroin purity have a significant effect on fentanyl-related overdoses, particularly in those areas where prescription opioids are highly available. Copyright © 2013 John Wiley & Sons, Ltd.

  16. Defining the purity of exosomes required for diagnostic profiling of small RNA suitable for biomarker discovery.

    Science.gov (United States)

    Quek, Camelia; Bellingham, Shayne A; Jung, Chol-Hee; Scicluna, Benjamin J; Shambrook, Mitch C; Sharples, Robyn A; Cheng, Lesley; Hill, Andrew F

    2017-02-01

    Small non-coding RNAs (ncRNA), including microRNAs (miRNA), enclosed in exosomes are being utilised for biomarker discovery in disease. Two common exosome isolation methods involve differential ultracentrifugation or differential ultracentrifugation coupled with Optiprep gradient fractionation. Generally, the incorporation of an Optiprep gradient provides better separation and increased purity of exosomes. The question of whether increased purity of exosomes is required for small ncRNA profiling, particularly in diagnostic and biomarker purposes, has not been addressed and highly debated. Utilizing an established neuronal cell system, we used next-generation sequencing to comprehensively profile ncRNA in cells and exosomes isolated by these 2 isolation methods. By comparing ncRNA content in exosomes from these two methods, we found that exosomes from both isolation methods were enriched with miRNAs and contained a diverse range of rRNA, small nuclear RNA, small nucleolar RNA and piwi-interacting RNA as compared with their cellular counterparts. Additionally, tRNA fragments (30-55 nucleotides in length) were identified in exosomes and may act as potential modulators for repressing protein translation. Overall, the outcome of this study confirms that ultracentrifugation-based method as a feasible approach to identify ncRNA biomarkers in exosomes.

  17. Lost Purity. Social in Nineteenth and Twentieth-century Feminisms

    Directory of Open Access Journals (Sweden)

    Paola Persano

    2016-07-01

    Full Text Available ‘Social Purity’ appears in a part of the French and Anglo-Saxon (Britain and the United States nineteenth-twentieth century’s feminisms, as a mean for many claims: from the full recognition of sexual difference in Hubertine Auclert’s social and ‘differentialist’ republicanism in France to Josephine Butler’s refusal of any purity imposed from above in England, until the absolute turn of the idea of women’s moral superiority and the equal and opposite force to the final exit from ‘the social’ by the American ‘New Womanism’, individualizing and de-feminizing the act of sexual liberation. All this in a continuous play of actions and reactions, sometimes paradoxical, weaving together suffragism and anti-suffragism, contestation of the conjugal complementarity and the never overcome temptations of hetero or self-control.

  18. Multi-kW cw fiber oscillator pumped by wavelength stabilized fiber coupled diode lasers

    Science.gov (United States)

    Becker, Frank; Neumann, Benjamin; Winkelmann, Lutz; Belke, Steffen; Ruppik, Stefan; Hefter, Ulrich; Köhler, Bernd; Wolf, Paul; Biesenbach, Jens

    2013-02-01

    High power Yb doped fiber laser sources are beside CO2- and disk lasers one of the working horses of industrial laser applications. Due to their inherently given robustness, scalability and high efficiency, fiber laser sources are best suited to fulfill the requirements of modern industrial laser applications in terms of power and beam quality. Pumping Yb doped single-mode fiber lasers at 976nm is very efficient. Thus, high power levels can be realized avoiding limiting nonlinear effects like SRS. However the absorption band of Yb doped glass around 976nm is very narrow. Therefore, one has to consider the wavelength shift of the diode lasers used for pumping. The output spectrum of passively cooled diode lasers is mainly defined by the applied current and by the heat sink temperature. Furthermore the overall emission line width of a high power pump source is dominated by the large number of needed diode laser emitters, each producing an individual spectrum. Even though it is possible to operate multi-kW cw single-mode fiber lasers with free running diode laser pumps, wavelength stabilizing techniques for diode lasers (e.g. volume holographic gratings, VHG) can be utilized in future fiber laser sources to increase the output power level while keeping the energy consumption constant. To clarify the benefits of wavelength stabilized diode lasers with integrated VHG for wavelength locking the performance of a dual side pumped fiber oscillator is discussed in this article. For comparison, different pumping configurations consisting of stabilized and free-running diode lasers are presented.

  19. Ruling out Higher-Order Interference from Purity Principles

    Directory of Open Access Journals (Sweden)

    Howard Barnum

    2017-06-01

    Full Text Available As first noted by Rafael Sorkin, there is a limit to quantum interference. The interference pattern formed in a multi-slit experiment is a function of the interference patterns formed between pairs of slits; there are no genuinely new features resulting from considering three slits instead of two. Sorkin has introduced a hierarchy of mathematically conceivable higher-order interference behaviours, where classical theory lies at the first level of this hierarchy and quantum theory theory at the second. Informally, the order in this hierarchy corresponds to the number of slits on which the interference pattern has an irreducible dependence. Many authors have wondered why quantum interference is limited to the second level of this hierarchy. Does the existence of higher-order interference violate some natural physical principle that we believe should be fundamental? In the current work we show that such principles can be found which limit interference behaviour to second-order, or “quantum-like”, interference, but that do not restrict us to the entire quantum formalism. We work within the operational framework of generalised probabilistic theories, and prove that any theory satisfying Causality, Purity Preservation, Pure Sharpness, and Purification—four principles that formalise the fundamental character of purity in nature—exhibits at most second-order interference. Hence these theories are, at least conceptually, very “close” to quantum theory. Along the way we show that systems in such theories correspond to Euclidean Jordan algebras. Hence, they are self-dual and, moreover, multi-slit experiments in such theories are described by pure projectors.

  20. Low purity glycerin supplementation in grazing cattle: bioeconomic analysis

    Directory of Open Access Journals (Sweden)

    Evani Souza de Oliveira Strada

    2015-07-01

    Full Text Available This study aimed to evaluate the dry matter intake, digestibility of diet components, performance, feed conversion, carcass characteristics and economics aspects of inclusion with low purity glycerin supplementation on cattle finished on pasture with Brachiaria decumbens. We used 35 male cattle bulls, predominantly Nellore, with initial body weight of 428.0 ± 32.11 kg, distributed in a completely randomized design with five treatments and seven replications. Treatments consisted of glycerin inclusion levels (0, 3, 6, 9 and 12% in the dry matter (DM. The animals were weighed every 28 days to assess the weight gain (ADG and adjust the diet. At the end of the experiment the animals were weighed to obtain the average final body weight (BWF and slaughtered to evaluate the carcass yield (HCY and carcass traits. The economic analysis was conducted in relation to weight gain in kilos, in order to verify the feasibility of the use of diets with five levels of glycerin, without considering other fixed and operational costs. Increased linearly (P <0.05 levels of glycerin on the intake and digestibility of ether extract and ADG. Linear effect (P <0.05 on the digestibility of neutral detergent fiber (CDFDN, crude protein (CDCP and feed conversion (FC. No effects were observed (P <0.05 the inclusion of glycerin on carcass traits evaluated. The inclusion of glycerin reduced the cost of production of meat at sign when the price of this ingredient represented up to 70% of the price of corn. Glycerin low purity can be included in the diet of cattle uncastrated finishing the pasture with improved performance and ncreased economic benefits.

  1. Ultrahigh-resolution Cn2 profiles derived from an FM-CW radar

    Science.gov (United States)

    Jordan, Jim R.; McLaughlin, Scott

    1992-08-01

    The U.S. Army Atmospheric Science Laboratory operates a frequency modulated-continuous wave (FM-CW) radar at White Sands Missile Range, New Mexico. This 10 cm wavelength radar has the unique capability of measuring 2 m resolution Cn2 profiles to 2 km above ground level. At this short wavelength, scattering from point targets, presumably insects, seriously contaminates the turbulence measurements. The ability of the FM-CW radar to resolve individual insects even at two km allows the insect signature to be removed from the turbulent backscatter. Radar calibration, data, and a technique for removing insect contamination are presented.

  2. The effect on radiochemical purity of modifications to the method of preparation and dilution of 99mTc-sestamibi.

    Science.gov (United States)

    Cooper, Maggie; Dustan, Kate; Rotureau, Laure

    2006-05-01

    99mTc-sestamibi is a useful radiopharmaceutical for myocardial perfusion imaging, parathyroid imaging and breast tumour imaging. However, the preparation is time consuming and the limit of 3 ml on the volume of liquid that can be added to the Cardiolite kit vial means that it is often difficult to draw up small doses for patient studies. To modify the method of preparation of 99mTc-sestamibi in order to reduce the preparation time and to give a preparation which is more convenient for withdrawing patient doses. A modified kit was prepared by reconstituting a Cardiolite kit vial with 3 ml Sodium Chloride Injection (0.9%) BP, sub-dividing it into two separate nitrogen-filled vials before adding sodium pertechnetate and boiling for radiolabelling. 99mTc-sestamibi was also prepared according to the manufacturer's recommended method and diluted with sodium chloride injection after preparation. Radiochemical purity was assessed by thin-layer chromatography and high-performance liquid chromatography. 99mTc-sestamibi prepared according to the manufacturer's recommended method had high radiochemical purity (96.9%+/-1.1%) and retained >90% radiochemical purity over 8 h following dilution. However, 99mTc-sestamibi prepared by the modified method gave variable and inconsistent results. The modified method of preparation was not robust enough to give reproducibly high radiochemical purity. However, dilution of 99mTc-sestamibi prepared according to the manufacturer's recommended method was satisfactory. This study highlights problems with the analysis of 99mTc-sestamibi and the limitations of modifying the method of preparation.

  3. Purity, adulteration and price of drugs bought on-line versus off-line in the Netherlands.

    Science.gov (United States)

    van der Gouwe, Daan; Brunt, Tibor M; van Laar, Margriet; van der Pol, Peggy

    2017-04-01

    On-line drug markets flourish and consumers have high expectations of on-line quality and drug value. The aim of this study was to (i) describe on-line drug purchases and (ii) compare on-line with off-line purchased drugs regarding purity, adulteration and price. Comparison of laboratory analyses of 32 663 drug consumer samples (stimulants and hallucinogens) purchased between January 2013 and January 2016, 928 of which were bought on-line. The Netherlands. Primary outcome measures were (i) the percentage of samples purchased on-line and (ii) the chemical purity of powders (or dosage per tablet); adulteration; and the price per gram, blotter or tablet of drugs bought on-line compared with drugs bought off-line. The proportion of drug samples purchased on-line increased from 1.4% in 2013 to 4.1% in 2015. The frequency varied widely, from a maximum of 6% for controlled, traditional substances [ecstasy tablets, 3,4-methylenedioxy-methamphetamine (MDMA) powder, amphetamine powder, cocaine powder, 4-bromo-2,5-dimethoxyphenethylamine (2C-B) and lysergic acid diethylamide (LSD)] to more than a third for new psychoactive substances (NPS) [4-fluoroamphetamine (4-FA), 5/6-(2-aminopropyl)benzofuran (5/6-APB) and methoxetamine (MXE)]. There were no large differences in drug purity, yet small but statistically significant differences were found for 4-FA (on-line 59% versus off-line 52% purity for 4-FA on average, P = 0.001), MDMA powders (45 versus 61% purity for MDMA, P = 0.02), 2C-B tablets (21 versus 10 mg 2C-B/tablet dosage, P = 0.49) and ecstasy tablets (131 versus 121 mg MDMA/tablet dosage, P = 0.05). The proportion of adulterated samples purchased on-line and off-line did not differ, except for 4-FA powder, being less adulterated on-line (χ2  = 8.3; P < 0.02). Drug prices were mainly higher on-line, ranging for various drugs from 10 to 23% higher than that of drugs purchased off-line (six of 10 substances: P < 0.05). Dutch drug users increasingly

  4. Corrosion in Supercritical carbon Dioxide: Materials, Environmental Purity, Surface Treatments, and Flow Issues

    Energy Technology Data Exchange (ETDEWEB)

    Sridharan, Kumar; Anderson, Mark

    2013-12-10

    The supercritical CO{sub 2} Brayton cycle is gaining importance for power conversion in the Generation IV fast reactor system because of its high conversion efficiencies. When used in conjunction with a sodium fast reactor, the supercritical CO{sub 2} cycle offers additional safety advantages by eliminating potential sodium-water interactions that may occur in a steam cycle. In power conversion systems for Generation IV fast reactors, supercritical CO{sub 2} temperatures could be in the range of 30°C to 650°C, depending on the specific component in the system. Materials corrosion primarily at high temperatures will be an important issue. Therefore, the corrosion performance limits for materials at various temperatures must be established. The proposed research will have four objectives centered on addressing corrosion issues in a high-temperature supercritical CO{sub 2} environment: Task 1: Evaluation of corrosion performance of candidate alloys in high-purity supercritical CO{sub 2}: The following alloys will be tested: Ferritic-martensitic Steels NF616 and HCM12A, austenitic alloys Incoloy 800H and 347 stainless steel, and two advanced concept alloys, AFA (alumina forming austenitic) steel and MA754. Supercritical CO{sub 2} testing will be performed at 450°C, 550°C, and 650°C at a pressure of 20 MPa, in a test facility that is already in place at the proposing university. High purity CO{sub 2} (99.9998%) will be used for these tests. Task 2: Investigation of the effects of CO, H{sub 2}O, and O{sub 2} impurities in supercritical CO{sub 2} on corrosion: Impurities that will inevitably present in the CO{sub 2} will play a critical role in dictating the extent of corrosion and corrosion mechanisms. These effects must be understood to identify the level of CO{sub 2} chemistry control needed to maintain sufficient levels of purity to manage corrosion. The individual effects of important impurities CO, H{sub 2}O, and O{sub 2} will be investigated by adding them

  5. A new approach to model CW CO2 laser using rate equations

    Indian Academy of Sciences (India)

    The other distinguishing feature of our model is the methodology adopted for carryingout the calculations. For instance, the CW case being a steady state, all the rate equations are thus equated to zero. In the prior works, researchers derived analytical expressions for the vibration level population densities, thatbecomes ...

  6. An Airborne Millimeter-Wave FM-CW Radar for Thickness Profiling of Freshwater Ice

    Science.gov (United States)

    1992-11-01

    Processor V silloscope rrg SCSI Card for Bernoulli Atn 80386 CPU ... .. .. ... =. : : . , . . .i : :" .::: .:::: :::. ’::::::Mo 3.5-in: :• !i~Floppy emo...34:::::: : ::::’: ,: Waterproof Aluminum ==== == === === Figure A52. FM-CW radar system implementation. 80386 DOS-based computer. Also included are an 80387 math coprocessor

  7. Independent tunability of the double-mode-locked cw dye laser.

    LENUS (Irish Health Repository)

    Bourkoff, E

    1979-06-01

    We report a new configuration that enables the double-mode-locked cw dye laser to be independently tunable. In addition, the output coupling at each of the two wavelengths can be independently specified. A series of oscillographs shows some interesting features unique to double mode locking and also shows the effects of varying the two cavity lengths with respect to each other.

  8. Broadly Turnable Pump-Resonant Diode-Pumped CW PPLN OPO

    Energy Technology Data Exchange (ETDEWEB)

    Alford, W.J.; Bowers, Mark S.; Raymond, T.D.; Seamans, J.F.

    1999-04-29

    We have observed low threshold operation of a broadly tunable (2.18-3.4 µm) pump-resonant cw periodically poled lithium niobate (PPLN) optical parametric oscillator (OPO). When pumped at 806 nm with 410 mW from a custom-built diode laser the OPO generated 20 mW of idler output at 3.3 µm.

  9. Absolute detection of metastable rare gas atoms by a cw laser photoionization method

    NARCIS (Netherlands)

    Schohl, S.; Klar, D.; Kraft, T.; Meijer, H.A.J.; Ruf, M.-W.; Schmitz, U.; Smith, S.J.; Hotop, H.

    1991-01-01

    A novel, accurate method for the absolute detection of metastable rare gas atoms is described and demonstrated. It involves a direct in situ determination of the electron emission coefficient γ for impact of the respective metastable atom on a conducting surface, γ is reliably obtained by a cw

  10. Beam-splitter mount for efficient monitoring of mode-locked and synchronously pumped CW lasers

    NARCIS (Netherlands)

    Hoek, van A.; Visser, A.J.W.G.

    1983-01-01

    Monitoring the optical pulses from mode-locked and synchronously pumped continuous wave (cw) lasers, reference beams are taken from the main beams with beam splitters. Depending on the angle with respect to the incident beam and the direction of the rotation axis of the beam splitter, light

  11. Laser and Electron Beam Processing of Semiconductors: CW Beam Processing of Ion Implanted Silicon

    Science.gov (United States)

    1980-12-31

    1000 A) amorphous layers. Both a scanned cw atoms placed on subsitutional lattice sites for a given anneal argon laser 3 and a scanned e-beam 4...dependence ofthe product v, Nc in the prefactor densities decrease monotonically with distance from the sili- of e., ln(e.IT 2) is plotted versus 1/kT

  12. Nonlinear Effects in CW Mode-Locked Solid-State Lasers with Semiconductor Saturable Absorbers

    OpenAIRE

    Kalashnikov, V. L.; Krimer, D.O.

    2000-01-01

    The influence of nonlinear properties of semiconductor saturable absorbers on ultrashort pulse generation was investigated. It was shown, that linewidth enhancement, quadratic and linear ac Stark effect contribute essentially to the mode locking in cw solid-state lasers, that can increase the pulse stability, decrease pulse duration and reduce the mode locking threshold

  13. Study of plasma formation in CW CO2 laser beam-metal surface interaction

    Science.gov (United States)

    Azharonok, V. V.; Vasilchenko, Zh V.; Golubev, Vladimir S.; Gresev, A. N.; Zabelin, Alexandre M.; Chubrik, N. I.; Shimanovich, V. D.

    1994-04-01

    An interaction of the cw CO2 laser beam and a moving metal surface has been studied. The pulsed and thermodynamical parameters of the surface plasma were investigated by optical and spectroscopical methods. The subsonic radiation wave propagation in the erosion plasma torch has been studied.

  14. Antiviral Potential of a Novel Compound CW-33 against Enterovirus A71 via Inhibition of Viral 2A Protease

    Directory of Open Access Journals (Sweden)

    Ching-Ying Wang

    2015-06-01

    Full Text Available Enterovirus A71 (EV-A71 in the Picornaviridae family causes hand-foot-and-mouth disease, aseptic meningitis, severe central nervous system disease, even death. EV-A71 2A protease cleaves Type I interferon (IFN-α/β receptor 1 (IFNAR1 to block IFN-induced Jak/STAT signaling. This study investigated anti-EV-A7l activity and synergistic mechanism(s of a novel furoquinoline alkaloid compound CW-33 alone and in combination with IFN-β Anti-EV-A71 activities of CW-33 alone and in combination with IFN-β were evaluated by inhibitory assays of virus-induced apoptosis, plaque formation, and virus yield. CW-33 showed antiviral activities with an IC50 of near 200 µM in EV-A71 plaque reduction and virus yield inhibition assays. While, anti-EV-A71 activities of CW-33 combined with 100 U/mL IFN-β exhibited a synergistic potency with an IC50 of approximate 1 µM in plaque reduction and virus yield inhibition assays. Molecular docking revealed CW-33 binding to EV-A71 2A protease active sites, correlating with an inhibitory effect of CW33 on in vitro enzymatic activity of recombinant 2A protease IC50 = 53.1 µM. Western blotting demonstrated CW-33 specifically inhibiting 2A protease-mediated cleavage of IFNAR1. CW-33 also recovered Type I IFN-induced Tyk2 and STAT1 phosphorylation as well as 2',5'-OAS upregulation in EV-A71 infected cells. The results demonstrated CW-33 inhibiting viral 2A protease activity to reduce Type I IFN antagonism of EV-A71. Therefore, CW-33 combined with a low-dose of Type I IFN could be applied in developing alternative approaches to treat EV-A71 infection.

  15. Power and Purity: Nature as Resource in a Troubled Society

    Directory of Open Access Journals (Sweden)

    Gremaud, Ann-Sofie

    2014-11-01

    Full Text Available This article analyses representations of nature as brand and resource in current Icelandic society. This is done through an interdisciplinary approach consisting of concepts from the discipline of cultural geography and the analytical methodologies of visual cultural, imagology, discourse and brand analysis used to highlight key narratives in images and written sources. The article discusses how ideas of purity are used in branding strategies and what they mean in Iceland today e.g. as a part of the emerging regional consciousness of ‘Arctic Iceland.’ The current overlapping crises of the economy, the environment and the collective self-image in Iceland have fostered critical representations of the past, present and future of the relationship between humans and the environment. Thus utilitarian environmental policies and shallow ecology is treated critically in contemporary Icelandic art, as is the question of what constitutes pollution. Such internal conflicts of interest are analysed to show critical perspectives on the dominant narratives about Icelandic nature and society that are communicated to the outside world through nation branding.

  16. Animal Sex: Purity Education and the Naturalization of the Abstinence Agenda

    Science.gov (United States)

    Sethna, Christabelle

    2010-01-01

    An early-twentieth-century movement for social purity in England, Canada and the United States aimed to eradicate prostitution, the double standard of sexual morals and their dreaded corollary, the venereal diseases. Social purists suggested that "purity education" for children was the best pedagogical prophylaxis against such…

  17. The Debye light scattering equation’s scaling relation reveals the purity of synthetic dendrimers

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, Hui-Yu; Chen, Hsiao-Ping [National Chung Cheng University, Department of Chemistry and Biochemistry (China); Tang, Yi-Hsuan [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry (China); Chen, Hui-Ting [Kaohsiung Medical University, Department of Fragrance and Cosmetic Science (China); Kao, Chai-Lin, E-mail: clkao@kmu.edu.tw [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry (China); Wang, Shau-Chun, E-mail: chescw@ccu.edu.tw [National Chung Cheng University, Department of Chemistry and Biochemistry (China)

    2016-03-15

    Spherical dendrimer structures cannot be structurally modeled using conventional polymer models of random coil or rod-like configurations during the calibration of the static light scattering (LS) detectors used to determine the molecular weight (M.W.) of a dendrimer or directly assess the purity of a synthetic compound. In this paper, we used the Debye equation-based scaling relation, which predicts that the static LS intensity per unit concentration is linearly proportional to the M.W. of a synthetic dendrimer in a dilute solution, as a tool to examine the purity of high-generational compounds and to monitor the progress of dendrimer preparations. Without using expensive equipment, such as nuclear magnetic resonance or mass spectrometry, this method only required an affordable flow injection set-up with an LS detector. Solutions of the purified dendrimers, including the poly(amidoamine) (PAMAM) dendrimer and its fourth to seventh generation pyridine derivatives with size range of 5–9 nm, were used to establish the scaling relation with high linearity. The use of artificially impure mixtures of six or seven generations revealed significant deviations from linearity. The raw synthesized products of the pyridine-modified PAMAM dendrimer, which included incompletely reacted dendrimers, were also examined to gauge the reaction progress. As a reaction toward a particular generational derivative of the PAMAM dendrimers proceeded over time, deviations from the linear scaling relation decreased. The difference between the polydispersity index of the incompletely converted products and that of the pure compounds was only about 0.01. The use of the Debye equation-based scaling relation, therefore, is much more useful than the polydispersity index for monitoring conversion processes toward an indicated functionality number in a given preparation.Graphical abstract.

  18. The Debye light scattering equation's scaling relation reveals the purity of synthetic dendrimers

    Science.gov (United States)

    Tseng, Hui-Yu; Chen, Hsiao-Ping; Tang, Yi-Hsuan; Chen, Hui-Ting; Kao, Chai-Lin; Wang, Shau-Chun

    2016-03-01

    Spherical dendrimer structures cannot be structurally modeled using conventional polymer models of random coil or rod-like configurations during the calibration of the static light scattering (LS) detectors used to determine the molecular weight (M.W.) of a dendrimer or directly assess the purity of a synthetic compound. In this paper, we used the Debye equation-based scaling relation, which predicts that the static LS intensity per unit concentration is linearly proportional to the M.W. of a synthetic dendrimer in a dilute solution, as a tool to examine the purity of high-generational compounds and to monitor the progress of dendrimer preparations. Without using expensive equipment, such as nuclear magnetic resonance or mass spectrometry, this method only required an affordable flow injection set-up with an LS detector. Solutions of the purified dendrimers, including the poly(amidoamine) (PAMAM) dendrimer and its fourth to seventh generation pyridine derivatives with size range of 5-9 nm, were used to establish the scaling relation with high linearity. The use of artificially impure mixtures of six or seven generations revealed significant deviations from linearity. The raw synthesized products of the pyridine-modified PAMAM dendrimer, which included incompletely reacted dendrimers, were also examined to gauge the reaction progress. As a reaction toward a particular generational derivative of the PAMAM dendrimers proceeded over time, deviations from the linear scaling relation decreased. The difference between the polydispersity index of the incompletely converted products and that of the pure compounds was only about 0.01. The use of the Debye equation-based scaling relation, therefore, is much more useful than the polydispersity index for monitoring conversion processes toward an indicated functionality number in a given preparation.

  19. Microstructure of Commercial Purity Titanium Subjected to Complex Loading by the Kobo Method

    Directory of Open Access Journals (Sweden)

    Kawałko J.

    2016-03-01

    Full Text Available Observations of refined microstructure of Commercial Purity titanium for applications in biomedical devices has been carried out. Refinement of titanium microstructure has been performed in process with complex strain scheme. Materials investigated in this work were: Commercial Purity titanium grade 2 and grade 4. Samples of as received materials were subjected to plastic deformation in complex loading process of extrusion combined with oscillation twisting (KoBo extrusion. Both types of samples were deformed in single step of extrusion, in temperature of 450 °C, with extrusion ratio 19.14 and 12.25 for grade 2 titanium and grade 4 titanium, respectively. Initial mean grain diameter for both types of materials was approximately 30 μm. Samples were investigated by means of crystal orientation microscopy. In both cases considerable microstructure refinement has been observed. Microstructures of deformed samples are heterogenous and consist of both elongated and fine equiaxed grains. Elongated grains (lamellae are separated by High Angle Grain Boundaries and feature internal structure with subgrains and dislocation walls. Grain refinement is stronger in material with higher extrusion ratio and mean grain diameter in this case is equal to 1.48 μm compared to 8.07 μm. in material with lower extrusion ratio. Mean misorientation angle (24° and 27° for grade 4 and grade 2 titanium indicates high fraction of HAGBs in microstructures of KoBo deformed samples. Misorientation fluctuations inside grains have been analyzed and distinct curvature of crystal lattice have been observed. Hardness of samples after plastic deformation increased from 174.6±3.4 and 234.9±3.5 to 205.0±3.2 and 251.2±2.2 for titanium grade 2 and grade 4 respectively.

  20. Quantitative nuclear magnetic resonance for purity assessment of polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Guimarães, E. F.; Vieira, A. A.; Rego, E. C. P.; Garrido, B. C.; Rodrigues, J. M.; Figueroa-Villar, J. D.

    2015-08-01

    The application of 1H quantitative nuclear magnetic resonance (1H qNMR) for purity determination of organic compounds is well documented in the literature. The aim of this work is to determine if the 1H qNMR method produces consistent values for the purity of polycyclic aromatic hydrocarbons (PAH) and is sufficiently accurate for the certification of reference materials. For this purpose, 15 different commercial PAH standards had their purity evaluated by 1H qNMR. The purity values and the associated expanded uncertainty of the 15 analyzed PAH ranged from (97.21 ± 0.28)% to (99.52 ± 1.10)%. The expanded measurement uncertainties were acceptable for the certification of reference materials and the purity values were in the expected range, confirming, therefore, that qNMR is appropriate for this type of analysis.

  1. External cultic tradition and internal ethical purity in Matthew 15

    Directory of Open Access Journals (Sweden)

    Francois P. Viljoen

    2014-03-01

    Full Text Available In Matthew 15:1–20, Jesus responds to the accusation made by the Pharisees and the scribes that his disciples do not observe the tradition of hand-washing (οὐ γὰρ νίπτονται τὰς χεῖραςὅταν ἄρτον ἐσθίωσιν, because they do not wash their hands before they eat bread. In this story of dispute, two ideas are interwoven, namely the locus of impurity (external or internal and the manmade tradition of the elders (ἡ παράδοσις τῶν πρεσβυτέρων versus the Word of God (ὁ λόγος τοῦ Θεοῦ. The Pharisees are depicted as obsessed with external manmade rules to ensure purity, whilst Jesus is concerned with inner purity based on God’s Word. In this article, the story is interpreted on two levels. The first level describes the dispute between Jesus and the Pharisees. The second level explores the tension the Matthean community experienced in their encounter with Pharisean Judaism of their day – the Judaism of the dual Torah. The question is which aspect of the Torah is challenged by Matthew’s Jesus, and what he considers to be the true meaning of the Law. It seems that Matthew uses this story to define and maintain the identity and values of his community over and against that of the Pharisees and their successors. Devices that Matthew uses to define the identity and required morality for his community, are identified. Such devices demonstrate how a community’s values can influence the identity and ethics of a society.In Matteus 15:1–20 reageer Jesus op die aantyging van die Fariseërs en skrifgeleerdes dat sy dissipels nie die handewas-tradisie eerbiedig nie. In hierdie verhaal van dispuut word twee idees vervleg: eerstens dié van die locus van onreinheid, en tweedens dié van mensgemaakte tradisies teenoor die Woord van God. Die Fariseërs word voorgestel as mense wat obsessiefis oor mensgemaakte reëls wat reinheid verseker, terwyl Jesus op innerlike reinheid

  2. Development of anabolic-androgenic steroids purity certified reference materials for anti-doping.

    Science.gov (United States)

    Quan, Can; Su, Fuhai; Wang, Haifeng; Li, Hongmei

    2011-12-20

    The need for certified reference materials (CRM) of anabolic-androgenic steroids reference materials was emphasized by the Beijing 2008 Olympic game as a tool to improve comparability, ensuring accuracy and traceability of analytical results for competing athletes. The China National Institute of Metrology (NIM) responded to the state request by providing seven anabolic-androgenic steroids (AAS) reference materials for Beijing Olympic anti-doping, GBW (E) 100086-GBW (E) 100092. This work describes the production of the series of AAS CRMs, according to ISO Guides 34 and 35 [1,2], which comprises the material processing, homogeneity and stability assessment, CRMs' characterization including moisture content, trace metal content. The AASs' purity values were assigned with collaborative study involved eight laboratories applying high resolution liquid chromatography-diode array detector (HPLC-DAD). Homogeneity of the AAS CRMs were determined by an in-house validated liquid chromatographic methodology. Potential degradation during storage was also investigated and a shelf-life based on this value was established. The certified values of CRMs were 99.76±0.079%, 99.76±0.25%, 99.63±0.09%, 99.67±0.11%, 98.82±0.56%, 96.30±0.39% and 99.71±0.49% (purity±expanded uncertainty with confidence level of 95%) for methyltestosterone, testosterone propionate, nandrolone, nandrolone 17-propionate, boldenone, trenbolone acetate and testosterone respectively. The certified values for all the studied AAS reference materials are traceable to the international system of units (SI). The CRMs developed were applied by 32 laboratory including sports organizations and analytical laboratories during the 2008 Olympic game for anti-doping control. Copyright © 2011 Elsevier Inc. All rights reserved.

  3. Isolation and enrichment of Cryptosporidium DNA and verification of DNA purity for whole-genome sequencing.

    Science.gov (United States)

    Guo, Yaqiong; Li, Na; Lysén, Colleen; Frace, Michael; Tang, Kevin; Sammons, Scott; Roellig, Dawn M; Feng, Yaoyu; Xiao, Lihua

    2015-02-01

    Whole-genome sequencing of Cryptosporidium spp. is hampered by difficulties in obtaining sufficient, highly pure genomic DNA from clinical specimens. In this study, we developed procedures for the isolation and enrichment of Cryptosporidium genomic DNA from fecal specimens and verification of DNA purity for whole-genome sequencing. The isolation and enrichment of genomic DNA were achieved by a combination of three oocyst purification steps and whole-genome amplification (WGA) of DNA from purified oocysts. Quantitative PCR (qPCR) analysis of WGA products was used as an initial quality assessment of amplified genomic DNA. The purity of WGA products was assessed by Sanger sequencing of cloned products. Next-generation sequencing tools were used in final evaluations of genome coverage and of the extent of contamination. Altogether, 24 fecal specimens of Cryptosporidium parvum, C. hominis, C. andersoni, C. ubiquitum, C. tyzzeri, and Cryptosporidium chipmunk genotype I were processed with the procedures. As expected, WGA products with low (sequences in Sanger sequencing. The cloning-sequencing analysis, however, showed significant contamination in 5 WGA products (proportion of positive colonies derived from Cryptosporidium genomic DNA, ≤25%). Following this strategy, 20 WGA products from six Cryptosporidium species or genotypes with low (mostly sequencing, generating sequence data covering 94.5% to 99.7% of Cryptosporidium genomes, with mostly minor contamination from bacterial, fungal, and host DNA. These results suggest that the described strategy can be used effectively for the isolation and enrichment of Cryptosporidium DNA from fecal specimens for whole-genome sequencing. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  4. Radiolabeling, quality control and radiochemical purity assessment of {sup 99m}Tc-HYNIC-TOC

    Energy Technology Data Exchange (ETDEWEB)

    Melero, Laura T.U.H.; Araujo, Elaine B.; Mengatti, Jair [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    Somatostatine receptors are widely expressed by several tumors, especially of the neuroendocrine origin. In vivo images of these tumors using radiolabeled somatostatine analogues became a useful clinical tool in oncology. The aim of this work was the radiolabeling of the somatostatine analogue HYNIC-TOC with 99mTc as well as the evaluation of the radiochemical stability and quality control of labeled complex. 99mTc-HYNIC-TOC was produced by labeling conditions using 20 {mu}g of peptide, 20 mg of tricine and 10 mg of EDDA as coligands, 1110 MBq of 99mTc (99Mo-99mTc IPEN-TEC generator) and 15 {mu}g of SnCl{sub 2}.2H{sub 2}O. The reaction proceeds for 10 minutes at boiling water bath. Radiochemical purity of labeled preparation was evaluated by different chromatographic systems: ITLC-SG in methanol:ammonium acetate (1:1); TLC-SG in sodium citrate buffer 0.1 N pH 5.0 and methylethylketone, and HPLC employing column C-18, 5 {mu}m, 4.6 mm x 250 mm, UV (220 nm), radioactivity detectors, 1 mL/minute flow of acetonitrile and trifluoroacetic acid solution 0.1 %. Labeled compound has been found radiochemically stable for 5 hours and radiochemical purity was higher than 90 %. The thin layer chromatographic systems enabled the separation of radiochemical species presented in the labeled mixture as well as HPLC system. The labeling procedure studied resulted in high radiochemical yield and easy preparation. Future works include the preparation of a lyophilized reagent to make feasible the preparation of 99mTc-HYNIC-TOC at nuclear medicine services in order to study the clinical potential of the radiopharmaceutical in diagnostic and staging of neuroendocrine tumors. (author)

  5. CW 100MW microwave power transfer in space

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, K. (Houston Univ., TX (United States). Inst. for Beam Particle Dynamics National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan) Texas Accelerator Center, The Woodlands, TX (United States)); Hiramatsu, S. (National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)); Shiho, M. (Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan))

    1991-01-01

    A proposal is made for high-power microwave transfer in space. The concept consists in a microwave power station integrating a multistage microwave free-electron laser and asymmetric dual-reflector system. Its use in space is discussed. 9 refs., 2 figs., 1 tab.

  6. FM-CW Based Miniature SAR System for Small UAVs

    NARCIS (Netherlands)

    Hoogeboom, P.; Wit, J.J.M. de; Meta, A.; Figueras, J.

    2005-01-01

    In some earth observation applications there is a requirement for low cost, high performance imaging radar systems small enough to be operated from small, even unmanned, aircraft. The existing pulse radars are non-cost effective complex systems. Therefore they are not suited for these applications.

  7. POTENTIAL CW AGENTS. TASK 3. ANALOGS OF TETRAHYDROCANNABINOL

    Science.gov (United States)

    The preparation of Adams’ most active tetrehydrocannabinol analog (Formula I, R=1,2-dimethylheptyl), and of synthetic tetrahydrocannabinol (I, R=n...beta-(3,5-dimethoxyphenyl) ethylanine. The pyrons related to tetrahydrocannabinol (II, R=n-amyl) has been reaction with aqueous ammonia to produce a high...amylphenol. An attempt will be made to condense this aminophenol with pulegone to give a nitrogen analog of tetrahydrocannabinol . The synthesis of pulegone from isopulegol has been accomplished.

  8. Canvas Supports and Grounds in Paintings by C.W. Eckersberg

    DEFF Research Database (Denmark)

    Filtenborg, Troels Folke; Krarup Andersen, Cecil

    2017-01-01

    The supports and grounds in 43 paintings on canvas by C.W. Eckersberg, dating from throughout his career, were investigated by visual examination, X-radiography, computer assisted automated thread counting and weave mapping, as well as by cross section analysis. The analytical data were complemen......The supports and grounds in 43 paintings on canvas by C.W. Eckersberg, dating from throughout his career, were investigated by visual examination, X-radiography, computer assisted automated thread counting and weave mapping, as well as by cross section analysis. The analytical data were...... complemented by written sources such as Eckersberg’s diaries, accounts and letters. The results show certain patterns in his practice and are discussed in relation to the varying locations and conditions in successive phases of his career and in view of contemporary paint technical treatises and circumstances...

  9. Starting dynamics of a cw passively mode-locked picosecond Ti:sapphire/DDI laser.

    Science.gov (United States)

    Pu, N W; Shieh, J M; Lai, Y; Pan, C L

    1995-01-15

    We show that, for a cw passively mode-locked picosecond Ti:sapphire/DDI laser, the first autocorrelation trace with negligible cw background occurs at a delay time of 20 mu;s, or 1600 round trips from the first relaxationoscillation peak. The trace suggests that the pulse consists of a primary pulse as short as 4.4 ps and of small secondary pulses that form a much wider pedestal of the trace, each containing approximately 50% of the photon energy. Nearly transform-limited approximately 5-ps-wide Gaussian pulses were observed at a delay time of 40 mu;s. After 45 mu;s, the optical spectrum broadened considerably, and the time-bandwidth product increased to 4 in the steady state (after 60 micros).

  10. Interaction of cw CO2 laser radiation with plasma near-metallic substrate surface

    Science.gov (United States)

    Azharonok, V. V.; Astapchik, S. A.; Zabelin, Alexandre M.; Golubev, Vladimir S.; Golubev, V. S.; Grezev, A. N.; Filatov, Igor V.; Chubrik, N. I.; Shimanovich, V. D.

    2000-07-01

    Optical and spectroscopic methods were used in studying near-surface plasma that is formed under the effect CW CO2 laser of (2- 5)x106W/cm2 power density upon stainless steel in He and Ar shielding gases. The variation of plume spatial structure with time has been studied, the outflow of gas-vapor jets from the interaction area has been characterized. The spectra of plasma plume pulsations have been obtained for the frequency range Δf = 0-1 MHz. The temperature and electron concentration of plasma plume have been found under radiation effect upon the target of stainless steel. Consideration has been given to the most probable mechanisms of CW laser radiation-metal non-stationary interaction.

  11. Generation conditions of CW Diode Laser Sustained Plasma

    Science.gov (United States)

    Nishimoto, Koji; Matsui, Makoto; Ono, Takahiro

    2016-09-01

    Laser sustained plasma was generated using 1 kW class continuous wave diode laser. The laser beam was focused on the seed plasma generated by arc discharge in 1 MPa xenon lamp. The diode laser has advantages of high energy conversion efficiency of 80%, ease of maintenance, compact size and availability of conventional quartz based optics. Therefore, it has a prospect of further development compared with conventional CO2 laser. In this study, variation of the plasma shape caused by laser power is observed and also temperature distribution in the direction of plasma radius is measured by optical emission spectroscopy.

  12. Development of an Airborne MMW FM-CW Radar for Mapping River Ice

    Science.gov (United States)

    1993-01-01

    installed in the33-MHz 80386 DOS- S..1.78 (Cumming 1952). based computer with an 80387 math coprocessor, a conventional 40-megabyte hard-drive and 4 mega...InterfaceI - 33M~836 CPU I x Antennas 1I. M 40 M Bernoull i LKF oppy Drive Hard Di 44 MB Disk Field-hardened Computer System Figure 5. MMWFM-CW radar system

  13. Power characteristics of CW second harmonic generation in periodically poled LiNbO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Bong Hoon; Rhee, Bum Ku [Dept. of Physics, Sogang University, Seoul (Korea, Republic of); Cha, Myoung Sik [Research Center for Dielectric and Advanced Matter Physics. Busan National University, Busan (Korea, Republic of)

    2002-07-01

    Power characteristics of CW second harmonic generation (SHG) in 0.5-mm-thick periodically poled LiNbO{sub 3} (PPLN) witha 6.5 μm domain period were investigated as a function of crystal length, and confocal parameter which was varied by using a lens of different focal length. We found there is the optimum condition of confocal parameter for SHG for a given intensity.

  14. Investigation of in-vivo skin autofluorescence lifetimes under long-term cw optical excitation

    Energy Technology Data Exchange (ETDEWEB)

    Lihachev, A; Ferulova, I; Vasiljeva, K; Spigulis, J [Institute of Atomic Physics and Spectroscopy, University of Latvia, Riga (Latvia)

    2014-08-31

    The main results obtained during the last five years in the field of laser-excited in-vivo human skin photobleaching effects are presented. The main achievements and results obtained, as well as methods and experimental devices are briefly described. In addition, the impact of long-term 405-nm cw low-power laser excitation on the skin autofluorescence lifetime is experimentally investigated. (laser biophotonics)

  15. Contribution of the low cycle fatigue on ultra high purity Ni-Cr-Fe alloys and on Ni monocrystals to the understanding of the hydrogen role in stress corrosion cracking for the alloys 600 and 690; Apport de la fatigue oligocyclique sur alliages Ni-Cr-Fe d'ultra haute purete et sur monocristaux de Ni a la comprehension sous contrainte des alliages 600 et 69O

    Energy Technology Data Exchange (ETDEWEB)

    Renaudot, N

    1999-06-01

    We discuss the role of hydrogen in cracking of Ni base alloys used for pressurised water reactor (PWR) primary tubes (alloy 600 and 690). Cracking can be explained by a Stress Corrosion Cracking (SCC) phenomenon. For this purpose, Low cycle fatigue (R = - 1) under cathodic charging at room temperature is conducted to study hydrogen effects on propagation of cracks mechanically initiated by the formation of Persistent Slip Bands (PSB). Low cycle fatigue on Ultra High Purity specimens (Ni, alloy 600 and 690) reveals the very important hydrogen effect on crack propagation rate, whatever the Cr content in the Ni base alloy. If Cr seems to have an effect over-hydrogen penetration in specimens (by a protective film formation), it have no beneficial effect when hydrogen have diffused ahead of a crack tip. Propagation rates (transgranular or intergranular) are highly increased, no matter of the absence of impurities like sulphur. Then, in PWR, the difference in the behaviour of alloy 600 and 690 could be due to a slower microcrack propagation rate for alloy 690. Protective films could play an important role in this difference, which is to study. Low cycle fatigue on Ni single crystals oriented for single slip shows, for the first time on bulk specimen, a macroscopic softening which can be explained. by hydrogen-dislocation interactions. Moreover, a simple quantitative model based on these interactions results in the same softening as the one observed experimentally. These results allow to validate experimentally one of the most important steps in the 'Corrosion Enhanced Plasticity (CEP) model', i.e. the softening ahead of a stress corrosion crack tip by hydrogen dislocation interactions. This is of importance because this model can explain cracking in numerous FCC materials-environment couple. (author)

  16. Soil Aquifer Treatment (SAT) and Constructed Wetlands (CW) Applications for Nutrients and Organic Micropollutants (OMPs) Attenuation Using Primary and Secondary Wastewater Effluents

    KAUST Repository

    Hamadeh, Ahmed F.

    2014-06-01

    Constructed wetlands (CW) and soil aquifer treatment (SAT) represent natural wastewater treatment systems (NWTSs). The high costs of conventional wastewater treatment techniques encourage more studies to investigate lower cost treatment methods which make these appropriate for developing and also in developed countries. The main objective of this research was to investigate the removals of nutrients and organic micropollutants (OMPs) through SAT, CW and the CW-SAT hybrid system. CWs are an efficient technology to purify and remove different nutrients as well as OMPs from wastewater. They removed most of the dissolved organic matter (DOC), total nitrogen (TN), ammonium and phosphate. Furthermore, CWs aeration could be used as one of the alternatives to reduce CWs footprint by around 10%. The vegetation in CWs plays an essential role in the treatment especially for nitrogen and phosphate removals, it is responsible for the removal of 15%, 55%, 38%, and 22% for TN, dissolved organic nitrogen (DON), nitrate and phosphate, respectively. CWs achieved a very high removal for some OMPs; they attenuated acetaminophen, caffeine, fluoxetine and trimethoprim (>90%) under different redox conditions. Moreover, it was found that increasing temperature (up to 36 C) could enhance the removals of atenolol, caffeine, DEET and trimethoprim by 17%, 14%, 28% and 45%, respectively. On the other hand, some OMPs, were found to be removed by vegetation such as: acetaminophen, caffeine, fluoxetine, sulfamethoxazole, and trimethoprim. Moreover, atenolol, caffeine, fluoxetine and trimethoprim, showed high removal (>80%) through SAT system. It was also found that, temperature increasing and using primary instead of secondary effluent could enhance the removal of some OMPs. The CWs performance study showed that these systems are adapted to the prevailing extreme arid conditions and the average percent removals are about, 88%, 96%, 98%, 98% and 92%, for COD, BOD and TSS, ammonium and phosphate

  17. 28 W CW linearly polarized single mode all-fiber thulium-doped fiber laser operating at 1.95 μm

    Science.gov (United States)

    Wang, Jiachen; Yeom, Dong-il; Lee, Sang Bae; Lee, Kwanil

    2017-04-01

    An all-fiber type, CW, linearly polarized thulium-doped fiber laser is reported. Highly linear polarization was achieved by a special management of fiber Bragg gratings, which performs as the laser cavity reflectors. The laser generated 28 W signal output at 1949 nm with a slope efficiency of 47.3%. The polarization extinction ratio of the laser was measured to be around 20 dB. The beam quality of the laser was near diffraction-limited, with M2 of 1.1. The laser's output features make it to be a potential light source for some important applications such as for pumping holmium-doped solid state lasers.

  18. Bone marrow transplantation with unrelated donors: what is the probability of identifying an HLA-A/B/Cw/DRB1/B3/B5/DQB1-matched donor?

    Science.gov (United States)

    Tiercy, J M; Bujan-Lose, M; Chapuis, B; Gratwohl, A; Gmür, J; Seger, R; Kern, M; Morell, A; Roosnek, E

    2000-08-01

    Patients transplanted with marrow from an HLA-ABDR serologically matched unrelated donor suffer from more post-transplant complications than those who are transplanted with marrow from an HLA-identical sibling. This is most likely due to either HLA-ABDR incompatibilities not resolved by standard techniques and/or HLA polymorphisms not tested for by routine tissue typing (HLA-Cw,-DQ). By resolving these incompatibilities by molecular techniques combined with the in vitro cytotoxic T lymphocyte precursor frequency (CTLpf) test, we have shown that a high degree of HLA compatibility is associated with increased patient survival. However, higher requirements for HLA matching decrease the number of available donors. We have estimated the probability of finding an HLA-A/B/Cw/DRB1/DRB3/DRB5/DQB1 compatible donor based on 104 consecutive unrelated bone marrow donor searches initiated between January 1995 and December 1997, with December 1998 as the endpoint. For 96 patients (92.3%), one or more ABDR-identical donors were listed in the Bone Marrow Donor Worldwide Registry (BMDW). After contacting the registries, we obtained at least one (mean, 5.36; range, 1-20; total, 461) blood sample for 86 patients. A highly compatible donor was identified for 33/86 patients (38.4%), after testing an average number of 4.5 donors/patients (range, 1-13). However, by accepting an HLA-DRB3 or -DQB1 or -Cw incompatibility, this number would be as high as 68.6%. Approximately half of the patients (n = 40) for whom a search had been initiated have been transplanted: 22 patients with a perfectly matched donor, 15 patients with an HLA-DRB3 or -DQB1 or -Cw mismatch and three with other mismatches. The average time needed to identify the most compatible donor was 4 months. Extremely long searches seemed to be less useful, because after testing the first seven, a more compatible donor was seldom found. These results show that even when requirements for compatibility are high, the chances of finding

  19. Evidence for orbital motion of CW Leonis from ground-based astrometry

    Science.gov (United States)

    Sozzetti, A.; Smart, R. L.; Drimmel, R.; Giacobbe, P.; Lattanzi, M. G.

    2017-10-01

    Recent Atacama Large Millimeter/submillimeter Array (ALMA) observations indicate that CW Leo, the closest carbon-rich asymptotic giant branch star to Sun, might have a low-mass stellar companion. We present archival ground-based astrometric measurements of CW Leo obtained within the context of the Torino Parallax Program and with >6 yr (1995-2001) of time baseline. The residuals to a single-star solution show significant curvature, and they are strongly correlated with the well-known I-band photometric variations due to stellar pulsations. We describe successfully the astrometry of CW Leo with a variability-induced motion (VIM) + acceleration model. We obtain proper motion and parallax of the centre-of-mass of the binary, the former in fair agreement with recent estimates, the latter at the near end of the range of inferred distances based on indirect methods. The VIM + acceleration model results allow us to derive a companion mass in agreement with that inferred by ALMA, they point towards a somewhat longer period than implied by ALMA, but are not compatible with much longer period estimates. These data will constitute a fundamental contribution towards the full understanding of the orbital architecture of the system when combined with Gaia astrometry, providing an ∼25 yr time baseline.

  20. Non-invasive optoacoustic temperature determination during retinal cw-laser treatments

    Science.gov (United States)

    Kandulla, Jochen; Elsner, Hanno; Sandeau, Julien; Birngruber, Reginald; Brinkmann, Ralf

    2006-02-01

    In almost all retinal laser treatments the therapeutic effect is initiated by a transient temperature increase. Due to differences in tissue properties and physiology like pigmentation and vascular blood flow an individually different temperature increase might occur with crucial effects on the therapeutic benefit of the treatment. In order to determine the individual retinal temperature increase during cw-laser irradiation in real-time we developed a non-invasive method based on optoacoustics. Simultaneously to the cw-laser irradiation (λ = 810 nm, P contact lens placed on the cornea. The experiments were performed in-vivo on rabbits. Simultaneous measurements with a miniaturized thermocouple showed a similar slope with a maximum local deviation of 0.4 °C for a temperature increase of 5.5 °C. On two rabbits measurements pre and post mortem at the same location were performed. The temperature increase after 60 s was found to raise by 12.0 % and 66.7 % post mortem, respectively. These data were used to calculate the influence of heat convection by blood circulation using a numerical model based on two absorbing layers and assuming a constant perfusion rate for the choriocapillaris and the choroid. Overall the presented optoacoustic method seems feasible for a non-invasive real-time determination of cw-laser induced retinal temperature increases and might serve as a temperature based dosimetry control during retinal laser treatments.

  1. Investigation of radical locations in various sesame seeds by CW EPR and 9-GHz EPR imaging.

    Science.gov (United States)

    Nakagawa, K; Hara, H

    2015-01-01

    We investigated the location of radical in various sesame seeds using continuous-wave (CW) electron paramagnetic resonance (EPR) and 9-GHz EPR imaging. CW EPR detected persistent radicals (single line) for various sesame seeds. The EPR linewidth of black sesame seeds was narrower than that of the irradiated white sesame seeds. A very small signal was detected for the white sesame seeds. Two-dimensional (2D) imaging using a 9-GHz EPR imager showed that radical locations vary for various sesame seeds. The paramagnetic species in black sesame seeds were located on the seed coat (skin) and in the hilum region. The signal with the highest intensity was obtained from the hilum part. A very low-intensity image was observed for the white sesame seeds. In addition, the 2D imaging of the irradiated white sesame seeds showed that free radicals were located throughout the entire seed. For the first time, CW EPR and 9-GHz EPR imaging showed the exact location of radical species in various sesame seeds.

  2. Parametric Four-Wave Mixing Using a Single cw Laser

    Science.gov (United States)

    Brekke, Erik; Herman, Emily; Alderson, Laura

    2014-05-01

    We present progress in using parametric four-wave mixing in a rubidium cell for the generation of coherent emission at 420 nm and 5.4 μm. A simple system using a single external cavity diode laser at 778 nm and a tapered amplifier supplies the needed optical beams. The efficiency is limited by absorption of the 420 nm beam, with single pass outputs of 40 μW. Optical pumping presents a possibility for increased output powers, but radiation trapping must be overcome at high densities. Several methods for increasing the effectiveness of the process are currently underway. The resulting beam at 420 nm presents an intriguing alternative method of exciting Rydberg states in Rubidium atoms.

  3. Tunable cw UV laser with spectroscopy of Sr Rydberg states.

    Science.gov (United States)

    Bridge, Elizabeth M; Keegan, Niamh C; Bounds, Alistair D; Boddy, Danielle; Sadler, Daniel P; Jones, Matthew P A

    2016-02-08

    We present a solid-state laser system that generates over 200 mW of continuous-wave, narrowband light, tunable from 316.3 nm - 317.7 nm and 318.0 nm - 319.3 nm. The laser is based on commercially available fiber amplifiers and optical frequency doubling technology, along with sum frequency generation in a periodically poled stoichiometric lithium tantalate crystal. The laser frequency is stabilized to an atomic-referenced high finesse optical transfer cavity. Using a GPS-referenced optical frequency comb we measure a long term frequency instability of spectroscopy of Sr Rydberg states from n = 37 - 81, demonstrating mode-hop-free scans of 24 GHz. In a cold atomic sample we measure Doppler-limited linewidths of 350 kHz.

  4. EPR and 55Mn cw-ENDOR study of an antiferrogmagnetically coupled dinuclear manganese (Mn III Mn IV) complex

    Science.gov (United States)

    Zweygart, W.; Bittl, R.; Wieghardt, K.; Lubitz, W.

    1996-10-01

    X- and Q-band EPR and 55Mn cw-ENDOR experiments are reported on a binuclear oxo-bridged dimanganese Mn III Mn IV complex. Consistent simulations of spectra from both frequency bands using one parameter set for the orthorhombic g tensor and Mn III and Mn IV hyperfine tensors are achieved. Information on the manganese hyperfine couplings is independently obtained from 55Mn cw-ENDOR spectroscopy performed on both ions.

  5. CW STED nanoscopy with a Ti:Sapphire oscillator

    Science.gov (United States)

    Liu, Yujia; Xie, Hao; Alonas, Eric; Santangelo, Philip J.; Jin, Dayong; Xi, Peng

    2012-12-01

    Fluorescence microscopy has become an essential tool to study biological molecules, pathways and events in living cells, tissues and animals. Meanwhile, the conventional optical microscopy is limited by the wavelength of the light. Even the most advanced confocal microscopy or multiphoton microscopy can only yield optical resolution approaching the diffraction limit of ~200 nm. This is still larger than many subcellular structures, which are too small to be resolved in detail. These limitations have driven the development of super-resolution optical imaging methodologies over the past decade. The stimulated emission depletion (STED) microscopy was the first and most direct approach to overcoming the diffraction limit for far-field nanoscopy. Typically, the excitation focus is overlapped by an intense doughnut-shaped spot to instantly de-excite markers from their fluorescent state to the ground state by stimulated emission. This effectively eliminates the periphery of the Point Spread Function (PSF), resulting in a narrower focal region, or super-resolution. Scanning a sharpened spot through the specimen renders images with sub-diffraction resolution. Multi-color STED imaging can present important structural and functional information for protein-protein interaction. In this work, we presented a dual color, synchronization-free STED stimulated emission depletion (STED) microscopy with a Ti:Sapphire oscillator. The excitation wavelengths were 532nm and 635nm, respectively. With pump power of 4.6 W and sample irradiance of 310 mW, we achieved super-resolution as high as 71 nm. We also imaged 200 nm nanospheres as well as all three cytoskeletal elements (microtubules, intermediate filaments, and actin filaments), clearly demonstrating the super-resolution resolving power over conventional diffraction limited imaging. It also allowed us to discover that, Dylight 650, exhibits improved performance over ATTO647N, a fluorophore frequently used in STED. Furthermore, we

  6. Quantitative cw Overhauser effect dynamic nuclear polarization for the analysis of local water dynamics.

    Science.gov (United States)

    Franck, John M; Pavlova, Anna; Scott, John A; Han, Songi

    2013-10-01

    Liquid state Overhauser effect Dynamic Nuclear Polarization (ODNP) has experienced a recent resurgence of interest. The ODNP technique described here relies on the double resonance of electron spin resonance (ESR) at the most common, i.e. X-band (∼10GHz), frequency and ¹H nuclear magnetic resonance (NMR) at ∼15 MHz. It requires only a standard continuous wave (cw) ESR spectrometer with an NMR probe inserted or built into an X-band cavity. We focus on reviewing a new and powerful manifestation of ODNP as a high frequency NMR relaxometry tool that probes dipolar cross relaxation between the electron spins and the ¹H nuclear spins at X-band frequencies. This technique selectively measures the translational mobility of water within a volume extending 0.5-1.5 nm outward from a nitroxide radical spin probe that is attached to a targeted site of a macromolecule. It allows one to study the dynamics of water that hydrates or permeates the surface or interior of proteins, polymers, and lipid membrane vesicles. We begin by reviewing the recent advances that have helped develop ODNP into a tool for mapping the dynamic landscape of hydration water with sub-nanometer locality. In order to bind this work coherently together and to place it in the context of the extensive body of research in the field of NMR relaxometry, we then rephrase the analytical model and extend the description of the ODNP-derived NMR signal enhancements. This extended model highlights several aspects of ODNP data analysis, including the importance of considering all possible effects of microwave sample heating, the need to consider the error associated with various relaxation rates, and the unique ability of ODNP to probe the electron-¹H cross-relaxation process, which is uniquely sensitive to fast (tens of ps) dynamical processes. By implementing the relevant corrections in a stepwise fashion, this paper draws a consensus result from previous ODNP procedures and then shows how such data can be

  7. Purity and Defect Characterization of Single-Wall Carbon Nanotubes Using Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    Yasumitsu Miyata

    2011-01-01

    Full Text Available We investigated the purity and defects of single-wall carbon nanotubes (SWCNTs produced by various synthetic methods including chemical vapor deposition, arc discharge, and laser ablation. The SWCNT samples were characterized using scanning electron microscopy (SEM, thermogravimetric analysis (TGA, and Raman spectroscopy. Quantitative analysis of SEM images suggested that the G-band Raman intensity serves as an index for the purity. By contrast, the intensity ratio of G-band to D-band (G/D ratio reflects both the purity and the defect density of SWCNTs. The combination of G-band intensity and G/D ratio is useful for a quick, nondestructive evaluation of the purity and defect density of a SWCNT sample.

  8. NIST-Traceable NMR Method to Determine Quantitative Weight Percentage Purity of Mustard (HD) Feedstock Samples

    Science.gov (United States)

    2018-01-01

    ECBC-TR-1506 NIST-TRACEABLE NMR METHOD TO DETERMINE QUANTITATIVE WEIGHT PERCENTAGE PURITY OF MUSTARD (HD) FEEDSTOCK SAMPLES David J...McGarvey RESEARCH AND TECHNOLOGY DIRECTORATE William R. Creasy LEIDOS, INC. Abingdon, MD 21009-1261 Theresa R. Connell EXCET, INC...Jan 2012–May 2012 4. TITLE AND SUBTITLE NIST-Traceable NMR Method to Determine Quantitative Weight Percentage Purity of Mustard (HD) Feedstock

  9. Evaluation of radiochemical purities of some radiopharmaceuticals in Shiraz Namazi teaching hospital

    OpenAIRE

    Hossein Sadeghpour; Mehrosadat Alavi; Majid Shahedi; Seyed Mohammad Entezarmahdi; Amirhossein Sakhteman

    2015-01-01

    Many radiopharmaceuticals, as a special group of drugs, are eventually prepared at the nuclear medicine departments of the hospitals. Therefore, their quality control procedures such as sterility tests, radionuclide, radiochemical and chemical purity should be carried out in the hospitals. In this study, radiochemical purity for more than 300 preparations of three different radiopharmaceutical formulations from commercial kits were tested using instant thin layer chromatography. The formulati...

  10. Low energy consumption method for separating gaseous mixtures and in particular for medium purity oxygen production

    Science.gov (United States)

    Jujasz, Albert J.; Burkhart, James A.; Greenberg, Ralph

    1988-01-01

    A method for the separation of gaseous mixtures such as air and for producing medium purity oxygen, comprising compressing the gaseous mixture in a first compressor to about 3.9-4.1 atmospheres pressure, passing said compressed gaseous mixture in heat exchange relationship with sub-ambient temperature gaseous nitrogen, dividing the cooled, pressurized gaseous mixture into first and second streams, introducing the first stream into the high pressure chamber of a double rectification column, separating the gaseous mixture in the rectification column into a liquid oxygen-enriched stream and a gaseous nitrogen stream and supplying the gaseous nitrogen stream for cooling the compressed gaseous mixture, removing the liquid oxygen-enriched stream from the low pressure chamber of the rectification column and pumping the liquid, oxygen-enriched steam to a predetermined pressure, cooling the second stream, condensing the cooled second stream and evaporating the oxygen-enriched stream in an evaporator-condenser, delivering the condensed second stream to the high pressure chamber of the rectification column, and heating the oxygen-enriched stream and blending the oxygen-enriched stream with a compressed blend-air stream to the desired oxygen concentration.

  11. EBSD study of purity effects during hot working in austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    El Wahabi, M. [Centre SMS, CNRS UMR 5146, Ecole Nationale Superieure des Mines de Saint-Etienne, 158, cours Fauriel-42023, Saint-Etienne Cedex 2 (France) and Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, ETSEIB, Universidad Politecnica de Cataluna, Av. Diagonal 647, Barcelona 08028 (Spain)]. E-mail: elwahabi@emse.fr; Gavard, L. [Centre SMS, CNRS UMR 5146, Ecole Nationale Superieure des Mines de Saint-Etienne, 158, cours Fauriel-42023, Saint-Etienne Cedex 2 (France); Cabrera, J.M. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, ETSEIB, Universidad Politecnica de Cataluna, Av. Diagonal 647, Barcelona 08028 (Spain); Prado, J.M. [Departamento de Ciencia de los Materiales e Ingenieria Metalurgica, ETSEIB, Universidad Politecnica de Cataluna, Av. Diagonal 647, Barcelona 08028 (Spain); Montheillet, F. [Centre SMS, CNRS UMR 5146, Ecole Nationale Superieure des Mines de Saint-Etienne, 158, cours Fauriel-42023, Saint-Etienne Cedex 2 (France)

    2005-02-25

    The technique of electron back scattering diffraction (EBSD) is considered as a powerful instrument for the study of the microstructural changes during hot forming processes and gives the possibility to present the information in different ways (OIM, misorientation diagram and pole figures). The present work is focused on the observation by EBSD of the microstructure evolution during deformation at high temperature of three austenitic stainless steels: AISI-304H, AISI-304L and a high purity steel HP. The difference between the three steels is the content carbon and the presence of residual elements. To this aim compression tests were carried out at a constant strain rate of 0.001 s{sup -1} and different temperatures. The study showed an increase of twin boundary fractions and a diminution of substructure (low angle densities boundaries) at increasing temperatures. On the other hand, increasing carbon content promotes lower twin boundary fractions and larger amounts of low angle boundaries. This effect can be explained by the reduction of grain boundary mobility caused by increasing carbon contents, which in turn reduces the migration rate and consequently the probability of twin boundary generation. Moreover, the increment of low angle boundaries with carbon content accelerates the twin character loss. It was also found that the dynamically recrystallized grain size decreased at increasing carbon content due to a typical drag effect. No important features on textures were found during DDRX.

  12. High density-high purity graphite prepared by hot isostatic pressing in refractory metal containers

    Science.gov (United States)

    Hoenig, C.L.

    1994-08-09

    Porous graphite in solid form is hot isostatically pressed in a refractory metal container to produce a solid graphite monolith with a bulk density greater than or equal to 2.10 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed, chemically vapor deposited, or coated by some other suitable means onto graphite. Hot isostatic pressing at 2,200 C and 30 KSI (206.8 MPa) argon pressure for two hours produces a bulk density of 2.10 g/cc. Complex shapes can be made. 1 fig.

  13. Strengthening mechanisms in nanostructured high-purity aluminium deformed to high strain and annealed

    DEFF Research Database (Denmark)

    Kamikawa, Naoya; Huang, Xiaoxu; Tsuji, Nobuhiro

    2009-01-01

    Samples of pure aluminium (99.99%) have been produced by accumulative roll-bonding to a large strain followed by a heat treatment, where a two-step annealing process has been used to produce samples with large variations in structural parameters such as boundary spacing, misorientation angle and ...

  14. Method And System For Examining Biological Materials Using Low Power Cw Excitation Raman Spectroscopy.

    Energy Technology Data Exchange (ETDEWEB)

    Alfano, Robert R. (Bronx, NY); Wang, Wubao (Flushing, NY)

    2000-11-21

    A method and system for examining biological materials using low-power cw excitation Raman spectroscopy. In accordance with the teachings of the invention, a low-power continuous wave (cw) pump laser beam and a low-power cw Stokes (or anti-Stokes) probe laser beam simultaneously illuminate a biological material and traverse the biological material in collinearity. The pump beam, whose frequency is varied, is used to induce Raman emission from the biological material. The intensity of the probe beam, whose frequency is kept constant, is monitored as it leaves the biological material. When the difference between the pump and probe excitation frequencies is equal to a Raman vibrational mode frequency of the biological material, the weak probe signal becomes amplified by one or more orders of magnitude (typically up to about 10.sup.4 -10.sup.6) due to the Raman emission from the pump beam. In this manner, by monitoring the intensity of the probe beam emitted from the biological material as the pump beam is varied in frequency, one can obtain an excitation Raman spectrum for the biological material tested. The present invention may be applied to in the in vivo and/or in vitro diagnosis of diabetes, heart disease, hepatitis, cancers and other diseases by measuring the characteristic excitation Raman lines of blood glucose, cholesterol, serum glutamic oxalacetic transaminase (SGOT)/serum glutamic pyruvic tansaminase (SGPT), tissues and other corresponding Raman-active body constituents, respectively. For example, it may also be used to diagnose diseases associated with the concentration of Raman-active constituents in urine, lymph and saliva It may be used to identify cancer in the breast, cervix, uterus, ovaries and the like by measuring the fingerprint excitation Raman spectra of these tissues. It may also be used to reveal the growing of tumors or cancers by measuring the levels of nitric oxide in tissue.

  15. Remote wind sensing with a CW diode laser lidar beyond the coherence regime

    DEFF Research Database (Denmark)

    Hu, Qi; Rodrigo, Peter John; Pedersen, Christian

    2014-01-01

    We experimentally demonstrate for the first time (to our knowledge) a coherent CW lidar system capable of wind speed measurement at a probing distance beyond the coherence regime of the light source. A side-by-side wind measurement was conducted on the field using two lidar systems with identical...... optical designs but different laser linewidths. While one system was operating within the coherence regime, the other was measuring at least 2.4 times the coherence range. The probing distance of both lidars is 85 m and the radial wind speed correlation was measured to be r2=0.965 between the two lidars...

  16. CW seeded optical parametric amplifier providing wavelength and pulse duration tunable nearly transform limited pulses.

    Science.gov (United States)

    Hädrich, S; Gottschall, T; Rothhardt, J; Limpert, J; Tünnermann, A

    2010-02-01

    An optical parametric amplifier that delivers nearly transform limited pulses is presented. The center wavelength of these pulses can be tuned between 993 nm and 1070 nm and, at the same time, the pulse duration is varied between 206 fs and 650 fs. At the shortest pulse duration the pulse energy was increased up to 7.2 microJ at 50 kHz repetition rate. Variation of the wavelength is achieved by applying a tunable cw seed while the pulse duration can be varied via altering the pump pulse duration. This scheme offers superior flexibility and scaling possibilities.

  17. Fourier-Bessel Field Calculation and Tuning of a CW Annular Array

    DEFF Research Database (Denmark)

    Fox, Paul D.; Cheng, Jiqi; Lu, Jian-yu

    2002-01-01

    field by linking the quantized surface pressure profile to a set of limited diffraction Bessel beams propagating into the medium. In the limit, these become a known set of nondiffracting Bessel beams satisfying the lossless linear wave equation, which allow us to derive a linear matrix formulation......A 1-D Fourier-Bessel series method for computing and tuning the linear lossless field of flat continuous wave (CW) annular arrays is given and discussed with both numerical simulation and experimental verification. The technique provides a new method for modelling and manipulating the propagated...

  18. EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Characteristics of the evolution of a plasma formed by cw and pulse-periodic CO2 laser radiation in various gases

    Science.gov (United States)

    Kanevskiĭ, M. F.; Stepanova, M. A.

    1990-06-01

    An investigation was made of the interaction between high-power cw and pulse-periodic CO2 laser radiation and a low-threshold optical breakdown plasma near a metal surface. Characteristics of the breakdown plasma were studied as a function of the experimental conditions. A qualitative analysis was made of the results using a simple one-dimensional model for laser combustion waves.

  19. FPGA Implementation of the Pixel Purity Index Algorithm for Remotely Sensed Hyperspectral Image Analysis

    Directory of Open Access Journals (Sweden)

    Carlos González

    2010-01-01

    Full Text Available Hyperspectral imaging is a new emerging technology in remote sensing which generates hundreds of images, at different wavelength channels, for the same area on the surface of the Earth. Over the last years, many algorithms have been developed with the purpose of finding endmembers, assumed to be pure spectral signatures in remotely sensed hyperspectral data sets. One of the most popular techniques has been the pixel purity index (PPI. This algorithm is very time-consuming. The reconfigurability, compact size, and high computational power of Field programmable gate arrays (FPGAs make them particularly attractive for exploitation in remote sensing applications with (near real-time requirements. In this paper, we present an FPGA design for implementation of the PPI algorithm. Our systolic array design includes a DMA and implements a prefetching technique to reduce the penalties due to the I/O communications. We have also included a hardware module for random number generation. The proposed method has been tested using real hyperspectral data collected by NASA's Airborne Visible Infrared Imaging Spectrometer over the Cuprite mining district in Nevada. Experimental results reveal that the proposed hardware system is easily scalable and able to provide accurate results with compact size in (near real-time, which make our reconfigurable system appealing for on-board hyperspectral data processing.

  20. Purity, Victimhood and Agency: Fifteen years of the UN Trafficking Protocol

    Directory of Open Access Journals (Sweden)

    Marjan Wijers

    2015-04-01

    Full Text Available When the women’s movement reverted back to the nineteenth-century Victorian concept of ‘trafficking in women’ to address abuses of migrant women in the sex industry, it unwittingly adopted not only a highly morally biased concept—dividing women into innocent victims in need of rescue and guilty ones who can be abused with impunity—but also one with racist and nationalistic overtones. Despite efforts to counter these flaws, this inheritance continues to define the debate on trafficking today, exemplified by the distinction made by the United Nations Trafficking Protocol between so-called ‘sexual exploitation’ and ‘labour exploitation’ and its focus on the aspects of recruitment and movement. As a result, its implementation in the last fifteen years has led to a range of oppressive measures against sex workers and migrants in the name of combating trafficking. The focus on the purity and victimhood of women, coupled with the protection of national borders, not only impedes any serious effort to address the exploitation of human beings under forced labour and slavery-like conditions, but actually causes harm. The call of the anti-trafficking movement for a human rights-based approach does not necessarily solve these fundamental problems, as it tends to restrict itself to protecting the rights of trafficked persons, while neglecting or even denying the human rights of sex workers and migrants.

  1. Effects of spatial resolution and spectral purity on transvenous coronary angiography images

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, D.; Thomlinson, W.; Gumer, N.F. [and others

    1994-11-01

    Measurements have been made on the National Synchrotron Light Source (NSLS) Coronary Angiography X17B2 beamline under ideal and real imaging conditions to investigate the optimal imaging conditions for spatial resolution and spectral purity. The spatial resolution tests were performed using two multielement Si(Li) detectors (600 element, 0.5mm, pixel-pixel spacing; 1200 element, 0.25mm pixel-pixel spacing. Images were taken of phantoms containing iodine contrast agent over a wide range of incident beam absorption conditions. Patient images were also obtained using the same viewing projection with both detectors. Harmonics present in the imaging beam can be reduced by operating the superconducting wiggler source at reduced field strength. At regions of high absorption in the patient, the harmonics present can contribute to the detected signal. Iodine phantom images were obtained at a wiggler field strength of 3 Tesla (E{sub c}=13.3keV) and 4 Tesla (E{sub c}= I 7.8keV) for comparison. As before, patient images were obtained using the same projection at both wiggler fields. Results of the detector resolution and wiggler eld measurements will be presented for the phantoms as well as the patient scans.

  2. Room-temperature CW operation of a nitride-based vertical-cavity surface-emitting laser using thick GaInN quantum wells

    Science.gov (United States)

    Furuta, Takashi; Matsui, Kenjo; Horikawa, Kosuke; Ikeyama, Kazuki; Kozuka, Yugo; Yoshida, Shotaro; Akagi, Takanobu; Takeuchi, Tetsuya; Kamiyama, Satoshi; Iwaya, Motoaki; Akasaki, Isamu

    2016-05-01

    We demonstrated a room-temperature (RT) continuous-wave (CW) operation of a GaN-based vertical-cavity surface-emitting laser (VCSEL) using a thick GaInN quantum well (QW) active region and an AlInN/GaN distributed Bragg reflector. We first investigated the following two characteristics of a 6 nm GaInN 5 QWs active region in light-emitting diode (LED) structures. The light output power at a high current density (∼10 kA/cm2) from the 6 nm GaInN 5 QWs was the same or even higher than that from standard 3 nm 5 QWs. In addition, we found that hole injection into the farthest QW from a p-layer was sufficient. We then demonstrated a GaN-based VCSEL with the 6 nm 5 QWs, resulting in the optical confinement factor of 3.5%. The threshold current density under CW operation at RT was 7.5 kA/cm2 with a narrow (0.4 nm) emission spectrum of 413.5 nm peak wavelength.

  3. Three new bands of 18O16O18O by CW-CRDS between 6340 and 6800 cm-1

    Science.gov (United States)

    Starikova, E.; Barbe, A.; De Backer, M.-R.; Tyuterev, Vl. G.; Mondelain, D.; Kassi, S.; Campargue, A.

    2014-12-01

    Three very weak bands of the 18O16O18O isotopologue of ozone have been detected by high sensitivity CW-Cavity Ring Down Spectroscopy between 6340 and 6800 cm-1. They are vibrationally assigned as 2ν1+5ν3, ν1+4ν2+3ν3 and 3ν2+5ν3 and correspond to the highest frequency bands of this isotopologue detected so far. A total of 464, 318 and 194 transitions were rovibrationally assigned, respectively. The good agreement with theoretical values achieved for the derived band centres and rotational constants confirms the accuracy of the potential energy surface recently obtained via extensive ab initio calculations. A set of line intensities was measured and fitted to derive the first transition moment parameter of the three bands. The determined sets of effective Hamiltonian parameter and transition moment operators, as well as the experimental energy levels, were used to generate a complete list of 1526 transitions, provided as Supplementary materials. The calculated line-list allows generating a synthetic spectrum which reproduces satisfactorily the experimental spectrum.

  4. Numerical simulation and experimental investigation of Ti-6Al-4V melted by CW fiber laser at different pressures

    Science.gov (United States)

    Tabassum, Aasma; Zhou, Jie; Han, Bing; Ni, Xiao-wu; Sardar, Maryam

    2017-07-01

    The interaction of continuous wave (CW) fiber laser with Ti-6Al-4V alloy is investigated numerically and experimentally at different laser fluence values and ambient pressures of N2 atmosphere to determine the melting time threshold of Ti-6Al-4V alloy. A 2D-axisymmetric numerical model considering heat transfer and laminar flow is established to describe the melting process. The simulation results indicate that material melts earlier at lower pressure (8.0 Pa) than at higher pressure (8.8×104 Pa) in several milliseconds with the same laser fluence. The experimental results demonstrate that the melting time threshold at high laser fluence (above 1.89×108 W/m2) is shorter for lower pressure (vacuum), which is consistent with the simulation. While the melting time threshold at low laser fluence (below 1.89×108 W/m2) is shorter for higher pressure. The possible aspects which can affect the melting process include the increased heat loss induced by the heat conduction between the metal surface and the ambient gas with the increased pressure, and the absorption variation of the coarse surface resulted from the chemical reaction.

  5. Homogeneity and EPR metrics for assessment of regular grids used in CW EPR powder simulations

    Science.gov (United States)

    Crăciun, Cora

    2014-08-01

    CW EPR powder spectra may be approximated numerically using a spherical grid and a Voronoi tessellation-based cubature. For a given spin system, the quality of simulated EPR spectra depends on the grid type, size, and orientation in the molecular frame. In previous work, the grids used in CW EPR powder simulations have been compared mainly from geometric perspective. However, some grids with similar homogeneity degree generate different quality simulated spectra. This paper evaluates the grids from EPR perspective, by defining two metrics depending on the spin system characteristics and the grid Voronoi tessellation. The first metric determines if the grid points are EPR-centred in their Voronoi cells, based on the resonance magnetic field variations inside these cells. The second metric verifies if the adjacent Voronoi cells of the tessellation are EPR-overlapping, by computing the common range of their resonance magnetic field intervals. Beside a series of well known regular grids, the paper investigates a modified ZCW grid and a Fibonacci spherical code, which are new in the context of EPR simulations. For the investigated grids, the EPR metrics bring more information than the homogeneity quantities and are better related to the grids’ EPR behaviour, for different spin system symmetries. The metrics’ efficiency and limits are finally verified for grids generated from the initial ones, by using the original or magnetic field-constraint variants of the Spherical Centroidal Voronoi Tessellation method.

  6. Progress in III–nitrides: Process issue and purity perspective

    Indian Academy of Sciences (India)

    Unknown

    . The factors determining the .... field of the ferroelectric layer whereas GaN MIS struc- tures with conventional oxides require a high ... portant applications as exemplary materials to new theo- retical concepts and for practical applications. Such.

  7. Direct HPLC enantioseparation of omeprazole and its chiral impurities: application to the determination of enantiomeric purity of esomeprazole magnesium trihydrate.

    Science.gov (United States)

    Zanitti, Leo; Ferretti, Rosella; Gallinella, Bruno; La Torre, Francesco; Sanna, Maria Luisa; Mosca, Antonina; Cirilli, Roberto

    2010-09-05

    Analytical and semipreparative high-performance liquid chromatography (HPLC) enantioseparation of the proton-pump inhibitor omeprazole (OME) and its potential organic chiral impurities were accomplished on the immobilised-type Chiralpak IA chiral stationary phase (CSP) under both polar organic and normal-phase conditions. The (S)-enantiomers were isolated with a purity of >99% ee and their absolute configuration was empirically assigned by circular dichroism (CD) spectroscopy. A chemo- and enantioselective HPLC method was validated to control the enantiomeric purity of the (S)-enantiomer of OME (ESO), an active ingredient contained in drug products, in the presence of chiral and achiral related substances. The precision, linearity and accuracy of the determination of the (R)-impurity as well as the recovery of ESO from a pharmaceutical preparation were determined. The proposed method uses the mixture methyl tert-butylether (MtBE)-ethyl acetate (EA)-ethanol (EtOH)-diethylamine (DEA) 60:40:5:0.1 (v/v/v/v) as a mobile phase. In these conditions, linearity over the concentration range 0.5-25 microg/ml for (R)-enantiomer was obtained. The limits of detection and quantification were 99 and 333 ng/ml, respectively. The intra and inter-day assay precision was less than 2% (RSD%). 2010 Elsevier B.V. All rights reserved.

  8. Resolution and determination of enantiomeric purity of new chiral derivatives of xanthones using polysaccharide-based stationary phases.

    Science.gov (United States)

    Fernandes, Carla; Brandão, Pedro; Santos, Alexandre; Tiritan, Maria Elizabeth; Afonso, Carlos; Cass, Quezia B; Pinto, Madalena M

    2012-12-21

    The enantioresolution and determination of the enantiomeric purity of 24 new chiral derivatives of xanthones (CDXs) were investigated on polysaccharide-based chiral stationary phases (CSPs). The tris-3,5-dimethylphenylcarbamates of cellulose and amylose and tris-3,5-dimethoxyphenylcarbamate of amylose were selected as CSPs for this work. The separation of enantiomeric mixtures of CDXs was explored under multimodal elution conditions. All the enantiomeric mixtures of CDXs were enantioseparated with very high enantioselectivity and resolution with α and R(S) ranging from 1.43 to 12.41 and from 1.48 to 10.29, respectively. The best performances were achieved on amylose tris-3,5-dimethylphenylcarbamate stationary phase under polar organic elution conditions. Furthermore the enantiomeric purity for all the CDXs was measured, achieving values higher than 99%. Based on the obtained results, the influence of the mobile phases and structural features of the CSPs and CDXs on chiral discrimination are also discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Purity evaluation of carbon nanotube materials by thermogravimetric, TEM, and SEM methods.

    Science.gov (United States)

    Trigueiro, João Paulo C; Silva, Glaura G; Lavall, Rodrigo L; Furtado, Clascidia A; Oliveira, Sérgio; Ferlauto, Andre S; Lacerda, Rodrigo G; Ladeira, Luiz O; Liu, Jiang-Wen; Frost, Ray L; George, Graeme A

    2007-10-01

    Raw and purified samples of carbon nanotubes are considered as multicomponent systems with a distribution of carbonaceous, amorphous, multishell graphitic particles and nanotubes, together with the particles of metal compounds from the catalyst. With respect to the carbon nanotube fractions, a distribution of size, defect concentrations, and functionalities needs to be taken into account. In order to address the problem of quantitative evaluation of purity it is necessary to measure the quality and distribution of the carbon nanotubes. In this research conventional and high resolution thermogravimetry are applied to quantify different fractions of carbonaceous and metallic materials in raw and moderately purified single walled and multiwalled carbon nanotubes. For each oxidized fraction, defined by careful line shape analysis of the derivative thermogravimetric curves (DTG), the temperature of maximum rate of oxidation, the temperature range for this oxidation, related to the degree of homogeneity, and the amount of associated material is specified. The attribution of carbonaceous materials to each fraction in the distribution was based on SEM and TEM measurements and the literature. The MWNT purified sample with 1.6 wt% metal oxide was investigated by high resolution thermogravimetry (HRTG). The quantitative assessment for the carbonaceous fractions was 25 wt% of amorphous and high defect carbonaceous materials including nanotubes, 54 wt% MWNT and 20 wt% multishell graphitic particles. A qualitative evaluation of these fractions was obtained from the SEM and TEM images and supports these results. The accuracy of the values, taking into account other measurements performed on the same batch of material, should be more sensible than +/-4 wt%.

  10. Physics design of a CW high-power proton Linac for accelerator ...

    Indian Academy of Sciences (India)

    [7] T P Wangler, Principles of RF linear accelerators (John Wiley & Sons Inc., 1998). [8] K Shepard et al, Proceedings of the XIX International Linac Conference (Chicago, Illinois) p. 956. [9] C Pagani et al, Design criteria for elliptical cavities, SRF, 2001. [10] P Singh, S V L S Rao, Rajni Pande, T Basak, Shweta Roy, M Aslam, ...

  11. Household and meals versus the Temple purity system: Patterns of replication in Luke-Acts

    Directory of Open Access Journals (Sweden)

    J. H. Elliott

    1991-01-01

    Full Text Available In Luke-Acts the social codes and concepts associated with food and meals replicate and support the contrasting social codes, interests, and ideologies associated with the Jerusalem Temple, on the one hand, and the Christian household, on the other. In this study the thesis is advanced that in contrast to the Temple and the exclusivist purity and legal system it represents, Luke has used occasions of domestic dining and hospitality to depict an inclusive form of social relations which transcends previous Jewish purity regulations and which gives concrete social expression to the inclusive character of the gospel, the kingdom of God, and the Christian community.

  12. Chelating ligands: enhancers of quality and purity of biogas ...

    African Journals Online (AJOL)

    The quality of biogas depends largely on the percentage of methane and hydrogen sulphide gas present. High concentration of hydrogen sulphide results in low quality biogas. This work employed the use of chelating ligands in scrubbing hydrogen sulphide gas while improving the yield of methane gas. Experimental ...

  13. First Light Curve Analyses of Binary Systems AO Aqr, CW Aqr and ASAS 012206-4924.7

    OpenAIRE

    Ulas, Burak; Ulusoy, Ceren

    2015-01-01

    Using the data from the public database of the All Sky Automated Survey ({\\tt ASAS}) we performed the very first light curve analyses of the three eclipsing binary systems \\astrobj{AO~Aqr}, \\astrobj{CW~Aqr} and \\astrobj{ASAS~012206-4924.7}. The physical parameters of the systems were determined by the {\\tt PHOEBE} software. From an analysis of the ASAS data it was concluded that AO~Aqr was found to be a contact binary system while CW~Aqr and ASAS~012206-4924.7 were found to be near--contact a...

  14. Parallel SFC/MS-MUX screening to assess enantiomeric purity.

    Science.gov (United States)

    Laskar, Derek B; Zeng, Lu; Xu, Rongda; Kassel, Daniel B

    2008-08-01

    Enantiomeric excess (ee) was evaluated for two internally synthesized compound libraries using a high-throughput automated, intelligent four-channel parallel supercritical fluid chromatography/mass spectrometry system equipped with a multiplexed ion source interface (SFC/MS-MUX). The two libraries contained compounds spanning a wide range of enantiomeric ratios with structurally diverse chemical scaffolds and stereogenic centers. The system analyzed each sample simultaneously against four chiral columns using up to six organic modifiers. Enhancements to our previously published parallel supercritical fluid chromatography/mass spectrometry system were implemented to address the challenges associated with automated trace enantiomer identification and quantitation. A reversal of enantiomer elution order was observed for several samples across multiple CSPs and modifiers. The relationship between elution order and % ee accuracy is presented for compounds exhibiting high, middle and low % ee values. Despite incidences in which the minor enantiomer eluted prior to the major enantiomer with less than baseline resolution, the overall % ee was in agreement with separations in which full baseline resolution was achieved. The methods presented here demonstrate the value and utility of high-throughput ee determinations to support drug discovery and development programs. (c) 2008 Wiley-Liss, Inc.

  15. Structural purity of magnetite nanoparticles in magnetotactic bacteria.

    Science.gov (United States)

    Fischer, Anna; Schmitz, Manuel; Aichmayer, Barbara; Fratzl, Peter; Faivre, Damien

    2011-07-06

    Magnetosome biomineralization and chain formation in magnetotactic bacteria are two processes that are highly controlled at the cellular level in order to form cellular magnetic dipoles. However, even if the magnetosome chains are well characterized, controversial results about the microstructure of magnetosomes were obtained and its possible influence in the formation of the magnetic dipole is to be specified. For the first time, the microstructure of intracellular magnetosomes was investigated using high-resolution synchrotron X-ray diffraction. Significant differences in the lattice parameter were found between intracellular magnetosomes from cultured magnetotactic bacteria and isolated ones. Through comparison with abiotic control materials of similar size, we show that this difference can be associated with different oxidation states and that the biogenic nanomagnetite is stoichiometric, i.e. structurally pure whereas isolated magnetosomes are slightly oxidized. The hierarchical structuring of the magnetosome chain thus starts with the formation of structurally pure magnetite nanoparticles that in turn might influence the magnetic property of the magnetosome chains.

  16. Method and apparatus for measuring purity of noble gases

    Science.gov (United States)

    Austin, Robert

    2008-04-01

    A device for detecting impurities in a noble gas includes a detection chamber and a source of pulsed ultraviolet light. The pulse of the ultraviolet light is transferred into the detection chamber and onto a photocathode, thereby emitting a cloud of free electrons into the noble gas within the detection chamber. The cloud of electrons is attracted to the opposite end of the detection chamber by a high positive voltage potential at that end and focused onto a sensing anode. If there are impurities in the noble gas, some or all of the electrons within the cloud will bond with the impurity molecules and not reach the sensing anode. Therefore, measuring a lower signal at the sensing anode indicates a higher level of impurities while sensing a higher signal indicates fewer impurities. Impurities in the range of one part per billion can be measured by this device.

  17. Purity of food cooked in stainless steel utensils.

    Science.gov (United States)

    Flint, G N; Packirisamy, S

    1997-01-01

    An extensive programme of cooking operations, using household recipes, has shown that, apart from aberrant values associated with new pans on first use, the contribution made by 19% Cr/9% Ni stainless steel cooking utensils to chromium and nickel in the diet is negligible. New pans, if first used with acid fruits, showed a greater pick-up of chromium and nickel, ranging from approximately 1/20 to 1/3 and 1/20 to 1/2 of the normal daily intake of chromium and nickel respectively. This situation did not recur in subsequent usage, even after the pan had been cleaned by abrasion. A higher rate of chromium and nickel release in new pans on first use was observed on products from four manufactures and appears to be related to surface finish, since treatment of the surface of a new pan was partly, and in the case of electropolishing, wholly effective in eliminating their initial high release.

  18. Correlation between product purity and process parameters for the synthesis of Cu2ZnSnS4 nanoparticles using microwave irradiation

    Science.gov (United States)

    Ahmad, R.; Nicholson, K. S.; Nawaz, Q.; Peukert, W.; Distaso, M.

    2017-07-01

    Kesterites (CZT(S,Se)4) emerged as a favourable photovoltaic material, leading to solar cell efficiencies as high as 12.7%. The development of sustainable roll-to-roll printing processes that make use of Cu2ZnSnS4 (CZTS) nanoparticle inks requires the proper design of synthetic approaches and the understanding of the relation between process parameters and product purity. In the current paper, we developed this relationship by calculating a specific energy factor. A microwave-assisted synthetic method that operates at atmospheric pressure and makes use of eco-friendly solvents is established. Four solvents, i.e. ethylene glycol (EG), diethylene glycol (di-EG), triethylene glycol (tri-EG) and tetraethylene glycol (tet-EG) are compared and the temperature during the reaction is assessed by two different methods. In particular, two by-products have been identified, i.e. Cu2 - x S and a hexagonal phase. We show that the variation of reaction parameters such as power irradiation, type of solvent and precursor concentration influences the nanoparticles' sizes (from 12 to 6 nm) and also the temperature-time profile of reaction which, in turn, can be related to phase purity of CZTS nanoparticles. The results suggest that the product purity scales with the specific energy factor providing a useful tool to a rational design of high-quality CZTS nanoparticles.

  19. Increasing local density and purity of molecules/bacteria on a sensing surface from diluted blood using 3D hybrid electrokinetics.

    Science.gov (United States)

    Cheng, I-Fang; Chen, Tzu-Ying; Chao, Wen-Cheng

    2016-05-01

    We present a long-range and selective nanocolloid/molecular/bacteria concentrator based on 3D hybrid AC electrokinetics (ACEK) that includes AC dielectrophoresis (DEP) and biased AC electroosmosis (ACEO). Through a convergency comb-shaped electrode design, this long-range ACEO allows the effective transport of a high number of targets into the centre of the detection zone. In the proposed 3D hybrid electrokinetics model, 3D ACEO provides long-range transportation, and the 3D DEP provides an effective separation mechanism. Thus, detection targets ranging from nanoscale to micrometers could be selectively concentrated long-range from diluted blood. The proposed design was used for selectively concentrating nanocolloids and bacteria in the diluted blood sample, respectively. Compared to a 3D short-range dipolar electrode configuration, the detection limit of long-range 3D convergency tripolar electrode configuration is one order of magnitude higher. The result also shows that the 3D hybrid ACEK demonstrated a higher purity of any plane above the electrode, which compared positively to the same design of a 2D hybrid ACEK. The concentration factor of the proposed 3D hybrid electrokinetics device increased by several orders of local density and raised the local purity at least 6 orders (from 0.05% to greater than 99.9%). The chip is capable of making a DNA/protein/bacterial aggregate characterized by high local density and purity for further molecular and bacteria detection/analysis.

  20. NMR-based approach to the analysis of radiopharmaceuticals: radiochemical purity, specific activity, and radioactive concentration values by proton and tritium NMR spectroscopy.

    Science.gov (United States)

    Schenk, David J; Dormer, Peter G; Hesk, David; Pollack, Scott R; Lavey, Carolee Flader

    2015-06-15

    Compounds containing tritium are widely used across the drug discovery and development landscape. These materials are widely utilized because they can be efficiently synthesized and produced at high specific activity. Results from internally calibrated (3)H and (1)H nuclear magnetic resonance (NMR) spectroscopy suggests that at least in some cases, this calibrated approach could supplement or potentially replace radio-high-performance liquid chromatography for radiochemical purity, dilution and scintillation counting for the measurement of radioactivity per volume, and liquid chromatography/mass spectrometry analysis for the determination of specific activity. In summary, the NMR-derived values agreed with those from the standard approaches to within 1% to 9% for solution count and specific activity. Additionally, the NMR-derived values for radiochemical purity deviated by less than 5%. A benefit of this method is that these values may be calculated at the same time that (3)H NMR analysis provides the location and distribution of tritium atoms within the molecule. Presented and discussed here is the application of this method, advantages and disadvantages of the approach, and a rationale for utilizing internally calibrated (1)H and (3)H NMR spectroscopy for specific activity, radioactive concentration, and radiochemical purity whenever acquiring (3)H NMR for tritium location. Copyright © 2015 John Wiley & Sons, Ltd.