WorldWideScience

Sample records for means limit separation

  1. The limits of the mean field

    International Nuclear Information System (INIS)

    Guerra, E.M. de

    2001-01-01

    In these talks, we review non relativistic selfconsistent mean field theories, their scope and limitations. We first discuss static and time dependent mean field approaches for particles and quasiparticles, together with applications. We then discuss extensions that go beyond the non-relativistic independent particle limit. On the one hand, we consider extensions concerned with restoration of symmetries and with the treatment of collective modes, particularly by means of quantized ATDHF. On the other hand, we consider extensions concerned with the relativistic dynamics of bound nucleons. We present data on nucleon momentum distributions that show the need for relativistic mean field approach and probe the limits of the mean field concept. Illustrative applications of various methods are presented stressing the role that selfconsistency plays in providing a unifying reliable framework to study all sorts of properties and phenomena. From global properties such as size, mass, lifetime,.., to detailed structure in excitation spectra (high spin, RPA modes,..), as well as charge, magnetization and velocity distributions. (orig.)

  2. The separate universe approach to soft limits

    Energy Technology Data Exchange (ETDEWEB)

    Kenton, Zachary; Mulryne, David J., E-mail: z.a.kenton@qmul.ac.uk, E-mail: d.mulryne@qmul.ac.uk [School of Physics and Astronomy, Queen Mary University of London, Mile End Road, London, E1 4NS (United Kingdom)

    2016-10-01

    We develop a formalism for calculating soft limits of n -point inflationary correlation functions using separate universe techniques. Our method naturally allows for multiple fields and leads to an elegant diagrammatic approach. As an application we focus on the trispectrum produced by inflation with multiple light fields, giving explicit formulae for all possible single- and double-soft limits. We also investigate consistency relations and present an infinite tower of inequalities between soft correlation functions which generalise the Suyama-Yamaguchi inequality.

  3. Method for enhancing the resolving power of ion mobility separations over a limited mobility range

    Science.gov (United States)

    Shvartsburg, Alexandre A; Tang, Keqi; Smith, Richard D

    2014-09-23

    A method for raising the resolving power, specificity, and peak capacity of conventional ion mobility spectrometry is disclosed. Ions are separated in a dynamic electric field comprising an oscillatory field wave and opposing static field, or at least two counter propagating waves with different parameters (amplitude, profile, frequency, or speed). As the functional dependencies of mean drift velocity on the ion mobility in a wave and static field or in unequal waves differ, only single species is equilibrated while others drift in either direction and are mobility-separated. An ion mobility spectrum over a limited range is then acquired by measuring ion drift times through a fixed distance inside the gas-filled enclosure. The resolving power in the vicinity of equilibrium mobility substantially exceeds that for known traveling-wave or drift-tube IMS separations, with spectra over wider ranges obtainable by stitching multiple segments. The approach also enables low-cutoff, high-cutoff, and bandpass ion mobility filters.

  4. Reference mean temperature for evaluation of performance of thermal diffusion column for isotope separation

    International Nuclear Information System (INIS)

    Yamamoto, Ichiro; Kanagawa, Akira

    1987-01-01

    In order to evaluate separative performance of a thermal diffusion column, a simplification is usually made in which the temperature dependence of the relevant properties such as thermal diffusion constant is ignored and some proper mean values evaluated at a specific ''mean'' temperature are used. Adoption of weighted average of temperature distribution is common for the ''mean'' temperature, but there exists no definite way of determining mean temperature. The present paper proposes a new reference mean temperature determined by the equation governing the free convection. It is based on the fact that the multiplication effect of free convection is essential to separation by thermal diffusion column. The reference mean temperature is related to pressure difference between top and bottom of column and is higher than a mass-averaged temperature (due to gravitational force) by a contribution of viscous force. The reference mean temperature was calculated, as a reference, for an Ar isotope separating column with an inner hot radius of 0.2 mm and an outer cold radius of 5 mm. The results confirmed the validity of an approximate formula expressing effects of temperature difference and ratio of inner and outer radii of column explicitly for the temperature. The reference mean temperature calculated from pressure difference given by axisymmetric solution of equations of change was in good agreement with the analytical solution. (author)

  5. Beneficiation Of Chromium Waste By Means Of Magnetic And Gravitational Separation

    Directory of Open Access Journals (Sweden)

    Brożek M.

    2015-09-01

    Full Text Available The paper presents the results of investigations of chromium recovery from the Cr waste mud, originating in the production of sodium dichromate. The differentiation of physical properties of particles of different contents of chromium and magnesium compounds is a premise for the use of physical separation methods. The investigations were performed on 2 waste samples, taken by random from the waste dump. The investigations of magnetic and gravity concentration for sample I and II were made, respectively. The results of screen and float and sink analyses of sample II indicate that it is possible to obtain Cr- and Mg-enriched products by means of a combined method of separation, i.e. hydraulic classification and, next, gravitational concentration on the shaking table. The concept of gravity concentration of the tested chromium waste was verified in the technical scale on multiboard shaking tables. The advantage of these fittings in relation to laboratory conditions is the possibility of separation of discussed waste without previous classification. The longer time of separation on the industrial shaking table as well as the respective amount of water directed to the process together with feed enabled an exact separation of initial material. The obtained concentrate in such conditions contains from 25 to 35% Cr2O3, depending on the chromium content in the initial waste material. It results from the fractional magnetic analysis of sample I that by means of the magnetic separation it is possible to obtain the magnetic concentrate of Cr2O3 content minimum 20% and, simultaneously, to obtain the non-magnetic product of increased MgO content. The optimum separation conditions regarding the yield and content of Cr2O3 were determined. The highest value of criterion K for the grade of the concentrate containing over 20% of Cr2O3 is obtained when the 10 mm diameter balls and the 1150 kA/m magnetic field intensity are applied. The yield of the concentrate

  6. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1979-01-01

    A method is described for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption after which more of the excited molecules than nonexcited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium

  7. Pedestrian Flow in the Mean Field Limit

    KAUST Repository

    Haji Ali, Abdul Lateef

    2012-11-01

    We study the mean-field limit of a particle-based system modeling the behavior of many indistinguishable pedestrians as their number increases. The base model is a modified version of Helbing\\'s social force model. In the mean-field limit, the time-dependent density of two-dimensional pedestrians satisfies a four-dimensional integro-differential Fokker-Planck equation. To approximate the solution of the Fokker-Planck equation we use a time-splitting approach and solve the diffusion part using a Crank-Nicholson method. The advection part is solved using a Lax-Wendroff-Leveque method or an upwind Backward Euler method depending on the advection speed. Moreover, we use multilevel Monte Carlo to estimate observables from the particle-based system. We discuss these numerical methods, and present numerical results showing the convergence of observables that were calculated using the particle-based model as the number of pedestrians increases to those calculated using the probability density function satisfying the Fokker-Planck equation.

  8. 40 CFR 65.46 - Alternative means of emission limitation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Alternative means of emission limitation. 65.46 Section 65.46 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Storage Vessels § 65.46 Alternative means of emission...

  9. Flocking dynamics and mean-field limit in the Cucker-Smale-type model with topological interactions

    KAUST Repository

    Haskovec, Jan

    2013-10-01

    We introduce a Cucker-Smale-type model for flocking, where the strength of interaction between two agents depends on their relative separation (called "topological distance" in previous works), which is the number of intermediate individuals separating them. This makes the model scale-free and is motivated by recent extensive observations of starling flocks, suggesting that the interaction ruling animal collective behavior depends on topological rather than the metric distance. We study the conditions leading to asymptotic flocking in the topological model, defined as the convergence of the agents\\' velocities to a common vector. The shift from metric to topological interactions requires development of new analytical methods, taking into account the graph-theoretical nature of the problem. Moreover, we provide a rigorous derivation of the mean-field limit of large populations, recovering kinetic and hydrodynamic descriptions. In particular, we introduce the novel concept of relative separation in continuum descriptions, which is applicable to a broad variety of models of collective behavior. As an example, we shortly discuss a topological modification of the attraction-repulsion model and illustrate with numerical simulations that the modified model produces interesting new pattern dynamics. © 2013 Elsevier B.V. All rights reserved.

  10. Compliance of feed limits, does not mean compliance of food limits

    Directory of Open Access Journals (Sweden)

    van Raamsdonk LWD.

    2009-01-01

    Full Text Available The carry-over of contaminants from feed to animal food products is an important aspect of the animal production chain. For a proper containment, limits for feed as well food products are fixed for a series of chemicals, e.g. dioxins and dioxin-like PCBs, lead, cadmium, some chlorinated pesticides, and aflatoxin B1 (and its metabolite M1 in milk. The relationship between feed and food limits is an important issue. An ideal goal is to assure that compliance to a feed limits automatically results in compliance to food limits. In order to collect information about this relationship, several simulation models and a large database on transfer factors have been developed. An optimal choice between either a model or an application of data from the Transfer Database is based on both the knowledge level, and on the circumstances of the specific situation. To reach and validate such an optimal choice an Expert System Carry-Over is currently in development, containing four different modules: 1 the different calculation models and the Transfer Database, 2 a decision tree for choosing the optimal strategy, 3 data tables indicating knowledge levels of compound/animal/product parameters, and 4 supporting databases containing information on consumption and composition of daily diets, animal parameters, and amounts of (daily production. Calculations indicate that for dioxins compliance to feed levels does not necessarily mean that food limits are complied as well. Besides an estimation of the compliance to limits, the expert system is a tool for feed related risk assessments, and for planning of future research.

  11. On separation of heavy isotopes by means of selective ICRH

    International Nuclear Information System (INIS)

    Kotelnikov, I.A.; Kuzmin, S.G.; Volosov, V.I.

    1998-01-01

    The authors present a theoretical study of the isotope separation by means of isotopically selective ion cyclotron resonance plasma heating (ICRH). The special attention is devoted to the separation of gadolinium isotopes. The ions are supposed to pass through the device shown on Fig. 1 where they are heated by the full-turn-loop antenna that excites RF field with azimuthal number m = 0. They calculate the distribution function of ions in a plasma stream at the orifice of the device. A satisfactory separation is achieved for the following values of parameters. The length of heating zone ell = 200 cm, initial temperature of plasma stream T parallel = 5 eV, T perpendicular = 60 eV, the plasma radius a = 10 cm, plasma density n = 10 12 cm -3 , external magnetic field B = 30 kGs. The energy of resonance ions W = 100 divided-by 200 eV. The latter value is achieved if a current in the antenna loops is equal to 60A with full number of loops N = 150. With the specified parameters, the current in the plasma stream is equal to 15 divided-by 20A. Then the production rate equals to 100 kg of Gd 157 per year. Energy of Gd's ions after pass through the heating zone vs. their axial velocity

  12. Mean Field Limits for Interacting Diffusions in a Two-Scale Potential

    Science.gov (United States)

    Gomes, S. N.; Pavliotis, G. A.

    2018-06-01

    In this paper, we study the combined mean field and homogenization limits for a system of weakly interacting diffusions moving in a two-scale, locally periodic confining potential, of the form considered in Duncan et al. (Brownian motion in an N-scale periodic potential, arXiv:1605.05854, 2016b). We show that, although the mean field and homogenization limits commute for finite times, they do not, in general, commute in the long time limit. In particular, the bifurcation diagrams for the stationary states can be different depending on the order with which we take the two limits. Furthermore, we construct the bifurcation diagram for the stationary McKean-Vlasov equation in a two-scale potential, before passing to the homogenization limit, and we analyze the effect of the multiple local minima in the confining potential on the number and the stability of stationary solutions.

  13. Isotope separation process

    International Nuclear Information System (INIS)

    Thomas, W.R.L.

    1979-01-01

    The instant invention relates to an improved process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same element in said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by a step wherein more of the excited molecules than non-excited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium

  14. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1977-01-01

    The instant invention relates to a process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by a step wherein more of the excited molecules than nonexcited molecules are converted to a chemically different form which may be separated by means known in the art. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium. 15 claims, 1 figure

  15. Selective separation of anaerobic sludge by means of hydrocyclones; Selektive Abtrennung von Anaerobschlamm mit Hydrozyklonen

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, M.; Bohnet, M. [Technische Univ. Braunschweig (Germany). Inst. fuer Verfahrens- und Kerntechnik

    1999-07-01

    In anaerobic waste water cleaning, biomass concentration constitutes a central problem because of long generating times and low biomass sinking speeds. In order to decouple hydraulic retention time from biomass retention time, biomass must be fed back into the reactor. The fact that separation by means of common gravitational separators such as sedimentation tanks and baffle plate thickeners is unspecific results in the enrichment in the reactor of inorganic solids, whose presence is corollary to the anaerobic sludge process. Hence, industry has a great interest in separating anaerobic sludge into organic and inorganic constituents as a means of safeguarding high operating stability and degradation efficiency of anaerobic reactors. Hydrocyclones, permitting selective separation, are an obvious approach. (orig.) [German] Bei der anaeroben Abwasserreinigung ist die Biomassekonzentrierung aufgrund langer Generationszeiten und geringer Sinkgeschwindigkeiten der Biomasse ein zentrales Problem. Zur Entkopplung der hydraulischen Verweilzeit von der Verweilzeit der Biomasse ist eine Rueckfuehrung der Biomasse erforderlich. Da bisher eingesetzte Schwerkraftabscheider, wie Absetzbecken und Lamellenklaerer, unspezifisch trennen, kommt es zu einer Anreicherung anorganischer Feststoffe im Reaktor, die sich prozessbedingt im Anaerobschlamm befinden. So hat die Industrie ein grosses Interesse an einer Auftrennung des Anaerobschlamms in organische und anorganische Bestandteile, um eine hohe Betriebsstabilitaet und Abbauleistung der Anaerobreaktoren zu gewaehrleisten. Hierzu bieten sich Hydrozyklone an, weil mit ihnen eine selektive Trennung moeglich ist. (orig.)

  16. Phase separation of self-propelled ballistic particles

    Science.gov (United States)

    Bruss, Isaac R.; Glotzer, Sharon C.

    2018-04-01

    Self-propelled particles phase-separate into coexisting dense and dilute regions above a critical density. The statistical nature of their stochastic motion lends itself to various theories that predict the onset of phase separation. However, these theories are ill-equipped to describe such behavior when noise becomes negligible. To overcome this limitation, we present a predictive model that relies on two density-dependent timescales: τF, the mean time particles spend between collisions; and τC, the mean lifetime of a collision. We show that only when τF<τC do collisions last long enough to develop a growing cluster and initiate phase separation. Using both analytical calculations and active particle simulations, we measure these timescales and determine the critical density for phase separation in both two and three dimensions.

  17. Evaluation of separate renal function by means of 99mTc-aprotinin uptake test

    International Nuclear Information System (INIS)

    Aprile, C.; Saponaro, R.; Villa, G.; Carena, M.; Chiari, G.; Salvadeo, A.; Lunghi, F.; Piazza, V.

    1986-01-01

    The possibility that relative kidney uptake of technetium-99m aprotinin (TcA) might be indicative of separate renal function was investigated in 89 patients who underwent both effective renal plasma flow (ERPFs) and glomerular filtration rate (GFR) determination. A reference group consisted of 27 healthy volunteers, studied only with TcA. The correlation with ERPFs (r = .73) was similar to that previously reported and confirmed. The correlation with GFR (r = .68) was better if a subgroup of renal units with TcA uptake lower than 16% (lower normal limit) was considered. Most likely, glomerular filtration is a limiting factor of the tubular uptake of TcA, and when GFR is reduced, both parameters decrease in the same manner, while if GFR is normal the two parameters are relatively independent. The correlation between TcA and GFR in 32 children was very similar to that found in adults. TcA uptake test seems to be a useful indicator of separate renal function, providing morphological information at, the same time

  18. Radiative heat transfer exceeding the blackbody limit between macroscale planar surfaces separated by a nanosize vacuum gap

    Science.gov (United States)

    Bernardi, Michael P.; Milovich, Daniel; Francoeur, Mathieu

    2016-09-01

    Using Rytov's fluctuational electrodynamics framework, Polder and Van Hove predicted that radiative heat transfer between planar surfaces separated by a vacuum gap smaller than the thermal wavelength exceeds the blackbody limit due to tunnelling of evanescent modes. This finding has led to the conceptualization of systems capitalizing on evanescent modes such as thermophotovoltaic converters and thermal rectifiers. Their development is, however, limited by the lack of devices enabling radiative transfer between macroscale planar surfaces separated by a nanosize vacuum gap. Here we measure radiative heat transfer for large temperature differences (~120 K) using a custom-fabricated device in which the gap separating two 5 × 5 mm2 intrinsic silicon planar surfaces is modulated from 3,500 to 150 nm. A substantial enhancement over the blackbody limit by a factor of 8.4 is reported for a 150-nm-thick gap. Our device paves the way for the establishment of novel evanescent wave-based systems.

  19. Investigation of a transonic separating/reattaching shear layer by means of PIV

    Directory of Open Access Journals (Sweden)

    S. Scharnowski

    2015-01-01

    Full Text Available The separating/reattaching flow over an axisymmetric backward-facing step is analyzed experimentally by means of particle image velocimetry (PIV. The main purpose of the measurements is the investigation of the mean flow field as well as of the Reynolds stress distributions at a Mach number of 0.7 and at a Reynolds number of 3.3×105 based on the step height. Due to the strong progress of optical flow measurements in the last years it was possible to resolve all flow scales down to 180μm (≈1% of the step height with high precision. Thanks to the high spatial resolution it was found for the first time that the Reynolds stress distribution features a local minimum between the first part of the shear layer and a region inside the recirculation region. This implies a more complex wake dynamics than assumed before.

  20. Mean field limit for bosons with compact kernels interactions by Wigner measures transportation

    International Nuclear Information System (INIS)

    Liard, Quentin; Pawilowski, Boris

    2014-01-01

    We consider a class of many-body Hamiltonians composed of a free (kinetic) part and a multi-particle (potential) interaction with a compactness assumption on the latter part. We investigate the mean field limit of such quantum systems following the Wigner measures approach. We prove in particular the propagation of these measures along the flow of a nonlinear (Hartree) field equation. This enhances and complements some previous results of the same type shown in Z. Ammari and F. Nier and Fröhlich et al. [“Mean field limit for bosons and propagation of Wigner measures,” J. Math. Phys. 50(4), 042107 (2009); Z. Ammari and F. Nier and Fröhlich et al., “Mean field propagation of Wigner measures and BBGKY hierarchies for general bosonic states,” J. Math. Pures Appl. 95(6), 585–626 (2011); Z. Ammari and F. Nier and Fröhlich et al., “Mean-field- and classical limit of many-body Schrödinger dynamics for bosons,” Commun. Math. Phys. 271(3), 681–697 (2007)

  1. Dose limits, constraints, reference levels. What does it mean for radiation protection?

    International Nuclear Information System (INIS)

    Breckow, J.

    2016-01-01

    The established concept of radiation protection with its basic principles justification, optimization, and limitation has proved its value and is going to be continued. In its deeper meaning, however, the concept is rather subtle and complex. Furthermore, in some aspects there remain some breaches or inconsistencies. This is just true for the terms dose limit, reference lever, and constraint that are tightly associated with the radiation protection principles. In order to guarantee the ability of radiation protection in whole extent, the subtle differences of meaning have to be communicated. There is a permanent need to defend the conceptual function of these terms against deliberate or undeliberate misinterpretations. Reference levels are definitely not the same as dose limits and they may not be misused as such. Any attempt to misinterpret fundamental radiation protection principles for selfish purposes should discouraged vigorously.

  2. Viscoelastic effects in three-dimensional microphase separation of block copolymers : Dynamic mean-field density functional approach

    NARCIS (Netherlands)

    Maurits, NM; Zvelindovsky, AV; Fraaije, JGEM

    1998-01-01

    In the present paper, we extend the dynamic mean-field density functional method which describes microphase separation phenomena in polymer liquids, to account for viscoelastic effects. The effect of simple steady shear on polymer orientation and elongation is taken into account by adapting the

  3. Queller's separation condition explained and defended.

    Science.gov (United States)

    Birch, Jonathan; Marshall, James A R

    2014-10-01

    The theories of inclusive fitness and multilevel selection provide alternative perspectives on social evolution. The question of whether these perspectives are of equal generality remains a divisive issue. In an analysis based on the Price equation, Queller argued (by means of a principle he called the separation condition) that the two approaches are subject to the same limitations, arising from their fundamentally quantitative-genetical character. Recently, van Veelen et al. have challenged Queller's results, using this as the basis for a broader critique of the Price equation, the separation condition, and the very notion of inclusive fitness. Here we show that the van Veelen et al. model, when analyzed in the way Queller intended, confirms rather than refutes his original conclusions. We thereby confirm (i) that Queller's separation condition remains a legitimate theoretical principle and (ii) that the standard inclusive fitness and multilevel approaches are indeed subject to the same limitations.

  4. 41 CFR 302-3.314 - Is there a time limit when I must begin my travel and transportation upon separation?

    Science.gov (United States)

    2010-07-01

    ...-3.314 Is there a time limit when I must begin my travel and transportation upon separation? Yes, all... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false Is there a time limit when I must begin my travel and transportation upon separation? 302-3.314 Section 302-3.314 Public...

  5. Technical Barriers, Licenses and Tariffs as Means of Limiting Market Access

    DEFF Research Database (Denmark)

    Schröder, Philipp J.H.; Jørgensen, Jan Guldager

    2006-01-01

    Technical barriers (standards), import licenses and tariffs may be deployed as means of limiting the market access of foreign firms. The present paper examines these measures in a setting of monopolistic competition. We find that, if protection focuses predominantly on the number of foreign firms...... accessing the domestic market, a technical barrier (an import license) may dominate a tariff (tariff and a tech- nical barrier) in terms of consumer welfare, even when tariff revenues are fully redistributed. However, if protection pays su±cient focus on limiting the total import volume, then tariffs...

  6. Centrifugal gas separator

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, M

    1970-03-27

    A centrifugal gas separator of a highly endurable construction and with improved gas sealing qualities utilizes a cylincrical elastic bellows or similar system in cooperation with a system of dynamic pressure operable gas seals as means for removing separated gases from the interior of the rotor drum, collecting the separated gases in their respective separated gas chambers defined by the corresponding bellows and their supporting stationary wall members, gas seals and rotor end caps, and means for discharging to the exterior of the surrounding cylindrical wall member the gaseous components from their respective separated gas chambers. In the vicinity of the rotary drum motor is a mixed gas chamber and means for providing the gas mixture along a co-axial passage into the rotary drum chamber. Orifices are bored into the end caps of the rotary drum to direct the separated gases into the aforementioned separated gas chambers which, through the action of the gas seals, freely slide upon the rotating drum to collect and thereafter discharge the thus separated gases. Therefore, according to the present invention, helium gas used to prevent separated gas remixture is unnecessary and, furthermore, the gas seals and elastic bellows means provide an air-tight seal superior to that of the contact sealing system of the former art.

  7. Centrifugal gas separator

    International Nuclear Information System (INIS)

    Sakurai, Mitsuo.

    1970-01-01

    A centrifugal gas separator of a highly endurable construction and with improved gas sealing qualities utilizes a cylincrical elastic bellows or similar system in cooperation with a system of dynamic pressure operable gas seals as means for removing separated gases from the interior of the rotor drum, collecting the separated gases in their respective separated gas chambers defined by the corresponding bellows and their supporting stationary wall members, gas seals and rotor end caps, and means for discharging to the exterior of the surrounding cylindrical wall member the gaseous components from their respective separated gas chambers. In the vicinity of the rotary drum motor is a mixed gas chamber and means for providing the gas mixture along a co-axial passage into the rotary drum chamber. Orifices are bored into the end caps of the rotary drum to direct the separated gases into the aforementioned separated gas chambers which, through the action of the gas seals, freely slide upon the rotating drum to collect and thereafter discharge the thus separated gases. Therefore, according to the present invention, helium gas used to prevent separated gas remixture is unnecessary and, furthermore, the gas seals and elastic bellows means provide an air-tight seal superior to that of the contact sealing system of the former art. (K.J. Owens)

  8. Studies of the analytical and preparatory separation of the lanthanide series by means of high-pressure-liquid-chromatography

    International Nuclear Information System (INIS)

    Weuster, W.

    1980-01-01

    With the Elution-system di-iso-propylether/tetrahydrofurane/di-(2-ethylhexyl)-phosphate/nitric acid all lanthanide series elements can be separated. To optimize the separation, these reactions are studied as a function of sorbent, composition, velocity and temperature of eluting agents. The rare earth elements are detected by observation of the extinguishing fluorescence, excited at a wavelength of 240 nm, with a detection limit of 2.5 μg rare earth material per ml of eluate. The method has been used for the determination of rare earth concentrations in minerals and technical products, for chemical separation of rare earths (i.e. Eu/Gd in mg quantities with a 1:10 quantity ratio) and for the separation of rare earth elements from uranium and fission products. In addition the possibility of isotope enrichment has been demonstrated in the case of 144 Sm/ 154 Sm. (DG) [de

  9. Technical barriers, import licenses and tariffs as means of limiting market access

    DEFF Research Database (Denmark)

    Jørgensen, Jan G.; Schröder, Philipp

    2003-01-01

    Technical barriers (standards), import licenses and tariffs may be deployed as means of limiting the market entry of foreign firms. The present paper examines these measures in a setting of monopolistic competition. It is established that -- contrary to what one would expect -- a technical barrier...

  10. Polymer solution phase separation: Microgravity simulation

    Science.gov (United States)

    Cerny, Lawrence C.; Sutter, James K.

    1989-01-01

    In many multicomponent systems, a transition from a single phase of uniform composition to a multiphase state with separated regions of different composition can be induced by changes in temperature and shear. The density difference between the phase and thermal and/or shear gradients within the system results in buoyancy driven convection. These differences affect kinetics of the phase separation if the system has a sufficiently low viscosity. This investigation presents more preliminary developments of a theoretical model in order to describe effects of the buoyancy driven convection in phase separation kinetics. Polymer solutions were employed as model systems because of the ease with which density differences can be systematically varied and because of the importance of phase separation in the processing and properties of polymeric materials. The results indicate that the kinetics of the phase separation can be performed viscometrically using laser light scattering as a principle means of following the process quantitatively. Isopycnic polymer solutions were used to determine the viscosity and density difference limits for polymer phase separation.

  11. Magnetic Separations with Magnetite: Theory, Operation, and Limitations

    Energy Technology Data Exchange (ETDEWEB)

    G. B. Cotten

    2000-08-01

    This dissertation documents the theory development and experimental plan followed to describe how a magnetite-based column under the influence of an external magnetic field functions as a magnetic separator. Theoretical simulations predict that weekly paramagnetic particles in the sub-micron range can be magnetically separated while diamagnetic particles as large as 2 microns in diameter may pass. Magnetite-based columns were evaluated as magnetically-controllable enhanced filtration devices. There was no evidence of enhanced filtration for diamagnetic particles by the magnetite-based bed. Magnetite-based magnetic separators have proven to be effective in specific laboratory experiments, indicating a potential feasibility for scale-up operations. Column media-filter type filtration effects indicate a magnetite-based column would not be suitable for treatment of a waste stream with a high diamagnetic solids content or high volume throughput requirements. Specific applications requiring removal of sub-micron para- or ferromagnetic particles under batch or Stokes flow conditions would be most applicable.

  12. Magnetic Separations with Magnetite: Theory, Operation, and Limitations

    International Nuclear Information System (INIS)

    Cotten, G.B.

    2000-01-01

    This dissertation documents the theory development and experimental plan followed to describe how a magnetite-based column under the influence of an external magnetic field functions as a magnetic separator. Theoretical simulations predict that weekly paramagnetic particles in the sub-micron range can be magnetically separated while diamagnetic particles as large as 2 microns in diameter may pass. Magnetite-based columns were evaluated as magnetically-controllable enhanced filtration devices. There was no evidence of enhanced filtration for diamagnetic particles by the magnetite-based bed. Magnetite-based magnetic separators have proven to be effective in specific laboratory experiments, indicating a potential feasibility for scale-up operations. Column media-filter type filtration effects indicate a magnetite-based column would not be suitable for treatment of a waste stream with a high diamagnetic solids content or high volume throughput requirements. Specific applications requiring removal of sub-micron para- or ferromagnetic particles under batch or Stokes flow conditions would be most applicable

  13. Dynamical mean-field theory and weakly non-linear analysis for the phase separation of active Brownian particles

    Energy Technology Data Exchange (ETDEWEB)

    Speck, Thomas [Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz (Germany); Menzel, Andreas M.; Bialké, Julian; Löwen, Hartmut [Institut für Theoretische Physik II, Heinrich-Heine-Universität, D-40225 Düsseldorf (Germany)

    2015-06-14

    Recently, we have derived an effective Cahn-Hilliard equation for the phase separation dynamics of active Brownian particles by performing a weakly non-linear analysis of the effective hydrodynamic equations for density and polarization [Speck et al., Phys. Rev. Lett. 112, 218304 (2014)]. Here, we develop and explore this strategy in more detail and show explicitly how to get to such a large-scale, mean-field description starting from the microscopic dynamics. The effective free energy emerging from this approach has the form of a conventional Ginzburg-Landau function. On the coarsest scale, our results thus agree with the mapping of active phase separation onto that of passive fluids with attractive interactions through a global effective free energy (motility-induced phase transition). Particular attention is paid to the square-gradient term necessary for the phase separation kinetics. We finally discuss results from numerical simulations corroborating the analytical results.

  14. Steam separator uprating by elimination of capacity-limiting mechanisms

    International Nuclear Information System (INIS)

    Parkinson, J.R.; Pruster, W.P.; Kidwell, J.H.; Schneider, W.G.

    1985-01-01

    Advanced steam/water separation equipment for nuclear steam generator application is required for new equipment manufacture and also for retrofit. For new equipment applications, the desire for higher capacity is driven by competitiveness which requires maximum throughput in the most compact package. For retrofit applications, which have arisen due to the poor performance of some of the original equipment, the need is for high capacity separators which can fit into the existing pressure vessel envelope and not only correct the performance problem, but also allow for uprated plant output. This paper describes the development of such advanced steam separators

  15. Fictional Separation Logic

    DEFF Research Database (Denmark)

    Jensen, Jonas Buhrkal; Birkedal, Lars

    2012-01-01

    , separation means physical separation. In this paper, we introduce \\emph{fictional separation logic}, which includes more general forms of fictional separating conjunctions P * Q, where "*" does not require physical separation, but may also be used in situations where the memory resources described by P and Q...

  16. Maximized Effective Energy Output of Contact-Separation-Triggered Triboelectric Nanogenerators as Limited by Air Breakdown

    KAUST Repository

    Zi, Yunlong; Wu, Changsheng; Ding, Wenbo; Wang, Zhong Lin

    2017-01-01

    Recent progress in triboelectric nanogenerators (TENGs) has demonstrated their promising potential as a high-efficiency mechanical energy harvesting technology, and plenty of effort has been devoted to improving the power output by maximizing the triboelectric surface charge density. However, due to high-voltage air breakdown, most of the enhanced surface charge density brought by material/surface optimization or external ion injection is not retainable or usable for electricity generation during the operation of contact-separation-triggered TENGs. Here, the existence of the air breakdown effect in a contact-separation mode TENG with a low threshold surface charge density of ≈40–50 µC m−2 is first validated under the high impedance external load, and then followed by the theoretical study of the maximized effective energy output as limited by air breakdown for contact-separation-triggered TENGs. The effects of air pressure and gas composition are also studied and propose promising solutions for reducing the air breakdown effect. This research provides a crucial fundamental study for TENG technology and its further development and applications.

  17. Maximized Effective Energy Output of Contact-Separation-Triggered Triboelectric Nanogenerators as Limited by Air Breakdown

    KAUST Repository

    Zi, Yunlong

    2017-05-02

    Recent progress in triboelectric nanogenerators (TENGs) has demonstrated their promising potential as a high-efficiency mechanical energy harvesting technology, and plenty of effort has been devoted to improving the power output by maximizing the triboelectric surface charge density. However, due to high-voltage air breakdown, most of the enhanced surface charge density brought by material/surface optimization or external ion injection is not retainable or usable for electricity generation during the operation of contact-separation-triggered TENGs. Here, the existence of the air breakdown effect in a contact-separation mode TENG with a low threshold surface charge density of ≈40–50 µC m−2 is first validated under the high impedance external load, and then followed by the theoretical study of the maximized effective energy output as limited by air breakdown for contact-separation-triggered TENGs. The effects of air pressure and gas composition are also studied and propose promising solutions for reducing the air breakdown effect. This research provides a crucial fundamental study for TENG technology and its further development and applications.

  18. Separation of copper flotation concentrates into density fractions by means of polytungstate aqueous solution

    Directory of Open Access Journals (Sweden)

    Luszczkiewicz Andrzej

    2016-01-01

    Full Text Available Industrial and laboratory flotation copper concentrates were subjected to separation into density fractions by means of heavy liquids in the form of sodium polytungstate aqueous solutions. For two samples, three densities factions were created, however in different density ranges. The density fractions were analyzed to establish the content of copper, lead, silver and organic carbon. The size of particles in both samples was similar (90-95% −0.071 mm. It was found that the lightest density fractions −2.45 and −2.0 g/cm3 still contained sulfide minerals scattered in the organic carbon bearing particles. Removal of the lightest density fraction (−2.0 g/cm3 from the industrial concentrate samples led to considerable reduction of organic carbon (92% and increasing its quality from 13 to 28% Cu. The mineralogical analysis of the heavy liquid separation products showed that most sulfide minerals were evenly dissemination in the heaviest density fractions with the recovery of 95-98%. The lightest density fraction of −2.0 g/cm3, being the richest in organic carbon, contained approximately 3% of unliberated sulfide minerals.

  19. Means on scattered compacta

    Directory of Open Access Journals (Sweden)

    Banakh T.

    2014-01-01

    Full Text Available We prove that a separable Hausdor_ topological space X containing a cocountable subset homeomorphic to [0, ω1] admits no separately continuous mean operation and no diagonally continuous n-mean for n ≥ 2.

  20. Closed-form confidence intervals for functions of the normal mean and standard deviation.

    Science.gov (United States)

    Donner, Allan; Zou, G Y

    2012-08-01

    Confidence interval methods for a normal mean and standard deviation are well known and simple to apply. However, the same cannot be said for important functions of these parameters. These functions include the normal distribution percentiles, the Bland-Altman limits of agreement, the coefficient of variation and Cohen's effect size. We present a simple approach to this problem by using variance estimates recovered from confidence limits computed for the mean and standard deviation separately. All resulting confidence intervals have closed forms. Simulation results demonstrate that this approach performs very well for limits of agreement, coefficients of variation and their differences.

  1. Practical nutritional recovery strategies for elite soccer players when limited time separates repeated matches.

    Science.gov (United States)

    Ranchordas, Mayur Krachna; Dawson, Joel T; Russell, Mark

    2017-01-01

    Specific guidelines that aim to facilitate the recovery of soccer players from the demands of training and a congested fixture schedule are lacking; especially in relation to evidence-based nutritional recommendations. The importance of repeated high level performance and injury avoidance while addressing the challenges of fixture scheduling, travel to away venues, and training commitments requires a strategic and practically feasible method of implementing specific nutritional strategies. Here we present evidence-based guidelines regarding nutritional recovery strategies within the context of soccer. An emphasis is placed on providing practically applicable guidelines for facilitation of recovery when multiple matches are played within a short period of time (i.e. 48 h). Following match-play, the restoration of liver and muscle glycogen stores (via consumption of ~1.2 g⋅kg -1 ⋅h -1 of carbohydrate) and augmentation of protein synthesis (via ~40 g of protein) should be prioritised in the first 20 min of recovery. Daily intakes of 6-10 g⋅kg -1 body mass of carbohydrate are recommended when limited time separates repeated matches while daily protein intakes of >1.5 g⋅kg -1 body mass should be targeted; possibly in the form of multiple smaller feedings (e.g., 6 × 20-40 g). At least 150% of the body mass lost during exercise should be consumed within 1 h and electrolytes added such that fluid losses are ameliorated. Strategic use of protein, leucine, creatine, polyphenols and omega-3 supplements could also offer practical means of enhancing post-match recovery.

  2. The possibility of separation of electronic waste by means of their electrical properties

    Directory of Open Access Journals (Sweden)

    Skowron Mikolaj

    2016-01-01

    Full Text Available Electric field has a lot of applications in technology. One of them is electrodynamic separation: electric field influences selectively granular solids of different moments or charges. A mathematical model of the separation process in high voltage drum separator is presented in the paper. Particles are charged both by induction and corona phenomena: next, they are separated by effects of the field forces. Some computational and experimental results are given and analyses.

  3. Prospects for separating heavy metal from contaminated soil

    International Nuclear Information System (INIS)

    Langen, M.; Hoberg, H.; Hamacher, B.

    1994-01-01

    For decades, large quantities of organic and inorganic pollutants have been brought into the soil as a result of the industrial operations of smelting and coking plants. This paper reports on the prospects of separating heavy metals from soil contaminated by smelting and coking plants by means of a physical/chemical washing procedure. Besides the description of virgin soil characteristics, cleaning results and process parameters of calssification, density separation and flotation processes are presented. It is shown that heavy metal pollution of virgin soil can be reduced by the classical process stages of soil washing. The metal content of virgin soil are critically assessed whereby the limits of the physical-chimical washing process will also be entered into. Emphasis is placed on the significance of the determination of limiting values for inorganic contamination, especially for soil contaminated with both organic and inorganic pollution. (orig.) [de

  4. Attempt at a de-confusion. Units, biological effects of radiation limits and their meaning

    Energy Technology Data Exchange (ETDEWEB)

    Mueck, K

    1986-01-01

    In the wake of the Chernobyl accident the public was greatly confused by the press because units quite unknown before used and large numbers suggested danger; the meaning of limits for radionuclide concentrations in foods was also misunderstood. The present paper attempts a clarification. (G.Q.).

  5. Separation of halogens from uranium compounds by means of pyrohydrolysis and their determination by ion chromatography

    International Nuclear Information System (INIS)

    Pires, M.A.F.; Brandao Filho, D.; Abrao, A.

    1987-07-01

    This paper describs the determination of fluorine in nuclear grade uranium compounds by means of phyrohydrolysis. A stream of wet oxygem at a temperature of 900 to 1000 0 C is passed through a quartz tube where the powdered samples is put. The halogens are volatilized as their respective acids that are absorbed in a buffer solution or water. The measurements are made with ion-seletive eletrodes or by ion chromatography. The sensitivity is of 1μg F - /g and 5μg Cl - /g. The separation of fluorine from uranium compounds by diferent methods is discussed. (Author) [pt

  6. Separation of metallic cations by means of coupled filtration on a ceramic membrane. Use of a complexing heteropolyanion

    International Nuclear Information System (INIS)

    Brun, Stephane

    1999-01-01

    In the field of the high level nuclear waste reprocessing, the Nuclear French Agency is currently carrying out studies on several processes (including the SESAME process) which aim at separating radioactive elements in order to dispose them specifically or to transmute them. One of these processes concerns the selective extraction of americium at an upper oxidation state than Ill. This work deals with the separation of Am(IV) from Ln(Ill) by means of complexation-coupled tangential filtration on alumina-titanium ceramic membranes. The chosen selective complexing agent is a lacunar heteropolyanion from the tungstophosphate family α_2P_2W_1_7O_6_1"1"0"-, which synthesis and various properties in solution have been studied. The polyanion stability in 0.5 M nitric solution strongly depends on the quality of the synthesised product. Two analytical techniques were developed to check the quality of the synthesised sets: "3"1P NMR and arsenazo-lanthanum complexometric titration. The separation studies on the cerium (IV)-neodymium (Ill) system were carried out to simulate americium(IV)/lanthanides(Ill) system. For the two alumina-titanium membranes studied (ultrafiltration and nano-filtration), the solvent flow can be described through a capillary mechanism which is characteristic of porous membranes. The ion transfer through the membranes, mainly governed by electrostatic interactions, strongly depends on the ionic strength at the membrane-solution interface. The best separation results, using nano-filtration, still remain below the expected performances, with a Ce(IV)/Nd(Ill) separation factor of 35 on a single stage in 0,5 M nitric medium. (author) [fr

  7. The development of 126Sn separation procedure by means of TBP resin

    International Nuclear Information System (INIS)

    Andris, Boris; Bena, Jozef

    2016-01-01

    Separation possibilities of 126 Sn with a new extraction-chromatographic material TBP Resin were studied. Suitable conditions for tin separation were determined in hydrochloric acid medium. 126 Sn was concentrated on TBP resin from 6 mol L -1 HCl and was eluted with 0.1 mol L -1 HCl. A purification step to remove 137 Cs with AMP-PAN column was necessary to obtain sufficiently purified samples which were directly measured with gamma spectrometry for 126 Sn activity. Separation of 126 Sn from a raw sludge sample was done according to proposed procedure, 126 Sn was detected and its activity was determined. (author)

  8. The island of knowledge the limits of science and the search for meaning

    CERN Document Server

    Gleiser, Marcelo

    2014-01-01

    Do all questions have answers? How much can we know about the world? Is there such a thing as an ultimate truth? To be human is to want to know, but what we are able to observe is only a tiny portion of what’s “out there.” In The Island of Knowledge, physicist Marcelo Gleiser traces our search for answers to the most fundamental questions of existence. In so doing, he reaches a provocative conclusion: science, the main tool we use to find answers, is fundamentally limited. These limits to our knowledge arise both from our tools of exploration and from the nature of physical reality: the speed of light, the uncertainty principle, the impossibility of seeing beyond the cosmic horizon, the incompleteness theorem, and our own limitations as an intelligent species. Recognizing limits in this way, Gleiser argues, is not a deterrent to progress or a surrendering to religion. Rather, it frees us to question the meaning and nature of the universe while affirming the central role of life and ourselves in it. Sc...

  9. Detection limit improvements forecasted at CTBTO IMS radionuclide stations based on size separation of aerosols by aerodynamic diameter

    International Nuclear Information System (INIS)

    Biegalski, S.; Ezekoye, O.A.; Pena, J.M.; Waye, S.; Pickering, M.

    2008-01-01

    Studies show that aerosols with natural activity have an aerodynamic diameter in the range of 0.1 to 1 μm. In contrast, nuclear explosions generally produce radioactive aerosols with aerodynamic diameters less than 0.1 μm and greater than 1 μm. These differences in aerosol sizes are quite fortuitous because they allow aerosol aerodynamic diameter to be utilized as a physical property to separate aerosols of natural origin from those produced in a nuclear explosion. Data collected in Austin, TX and at U.S. CTBT IMS radionuclide stations have been utilized to forecast detection limit improvements possible given an aerosol size separation capability. (author)

  10. Measuring meaning and peace with the FACIT-spiritual well-being scale: distinction without a difference?

    Science.gov (United States)

    Peterman, Amy H; Reeve, Charlie L; Winford, Eboni C; Cotton, Sian; Salsman, John M; McQuellon, Richard; Tsevat, Joel; Campbell, Cassie

    2014-03-01

    The Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being Scale (FACIT-Sp; Peterman, Fitchett, Brady, Hernandez, & Cella, 2002) has become a widely used measure of spirituality; however, there remain questions about its specific factor structure and the validity of scores from its separate scales. Specifically, it remains unclear whether the Meaning and Peace scales denote distinct factors. The present study addresses previous limitations by examining the extent to which the Meaning and Peace scales relate differentially to a variety of physical and mental health variables across 4 sets of data from adults with a number of chronic health conditions. Although a model with separate but correlated factors fit the data better, discriminant validity analyses indicated limited differences in the pattern of associations each scale showed with a wide array of commonly used health and quality-of-life measures. In total, the results suggest that people may distinguish between the concepts of Meaning and Peace, but the observed relations with health outcomes are primarily due to variance shared between the 2 factors. Additional research is needed to better understand the separate and joint role of Meaning and Peace in the quality of life of people with chronic illness. 2014 APA

  11. Validation of limited sampling models (LSM) for estimating AUC in therapeutic drug monitoring - is a separate validation group required?

    NARCIS (Netherlands)

    Proost, J. H.

    Objective: Limited sampling models (LSM) for estimating AUC in therapeutic drug monitoring are usually validated in a separate group of patients, according to published guidelines. The aim of this study is to evaluate the validation of LSM by comparing independent validation with cross-validation

  12. Algorithm based on regional separation for automatic grain boundary extraction using improved mean shift method

    Science.gov (United States)

    Zhenying, Xu; Jiandong, Zhu; Qi, Zhang; Yamba, Philip

    2018-06-01

    Metallographic microscopy shows that the vast majority of metal materials are composed of many small grains; the grain size of a metal is important for determining the tensile strength, toughness, plasticity, and other mechanical properties. In order to quantitatively evaluate grain size in metals, grain boundaries must be identified in metallographic images. Based on the phenomenon of grain boundary blurring or disconnection in metallographic images, this study develops an algorithm based on regional separation for automatically extracting grain boundaries by an improved mean shift method. Experimental observation shows that the grain boundaries obtained by the proposed algorithm are highly complete and accurate. This research has practical value because the proposed algorithm is suitable for grain boundary extraction from most metallographic images.

  13. Nonlinear rocket motor stability prediction: Limit amplitude, triggering, and mean pressure shifta)

    Science.gov (United States)

    Flandro, Gary A.; Fischbach, Sean R.; Majdalani, Joseph

    2007-09-01

    High-amplitude pressure oscillations in solid propellant rocket motor combustion chambers display nonlinear effects including: (1) limit cycle behavior in which the fluctuations may dwell for a considerable period of time near their peak amplitude, (2) elevated mean chamber pressure (DC shift), and (3) a triggering amplitude above which pulsing will cause an apparently stable system to transition to violent oscillations. Along with the obvious undesirable vibrations, these features constitute the most damaging impact of combustion instability on system reliability and structural integrity. The physical mechanisms behind these phenomena and their relationship to motor geometry and physical parameters must, therefore, be fully understood if instability is to be avoided in the design process, or if effective corrective measures must be devised during system development. Predictive algorithms now in use have limited ability to characterize the actual time evolution of the oscillations, and they do not supply the motor designer with information regarding peak amplitudes or the associated critical triggering amplitudes. A pivotal missing element is the ability to predict the mean pressure shift; clearly, the designer requires information regarding the maximum chamber pressure that might be experienced during motor operation. In this paper, a comprehensive nonlinear combustion instability model is described that supplies vital information. The central role played by steep-fronted waves is emphasized. The resulting algorithm provides both detailed physical models of nonlinear instability phenomena and the critically needed predictive capability. In particular, the origin of the DC shift is revealed.

  14. Uniform separation of plastic wastes; Sortenreine Trennung von Kunststoffabfaellen

    Energy Technology Data Exchange (ETDEWEB)

    Eisenmann, R [Hochschule fuer Technik und Wirtschaft des Saarlandes, Saarbruecken (Germany)

    1995-04-01

    The position of raw material recycling is defined by comparison of different recycling levels. Means and limits of the main applicable methods for separating uniform plastic fractions from mixed wastes are summarized. (orig.) [Deutsch] Durch Vergleich der verschiedenen Recyclingebenen wird der Stellenwert des werkstofflichen Recycling bestimmt. Eine Zusammenfassung der wichtigsten derzeit verfuegbaren Verfahren zur Abtrennung sortenreiner Kunststoff-Fraktionen aus Abfallgemischen zeigt Moeglichkeiten und Grenzen der einzelnen Methoden. (orig.)

  15. Os limites do sentido no ensino da matemática The limits of meaning in the teaching of mathematics

    Directory of Open Access Journals (Sweden)

    Maria da Conceição Ferreira Fonseca

    1999-06-01

    Full Text Available Em Os Limites do Sentido (1995, Eduardo Guimarães analisa os esforços de se resgatar a questão da significação nos estudos lingüísticos como gestos de incluir, no seu objeto, elementos que Saussure deliberadamente excluiu: o sujeito, o mundo e a história. Já no artigo As possibilidades de inovação no ensino-aprendizagem da matemática elementar, Manuela David (1995 faz um apanhado das tendências do ensino de Matemática que lhe parecem mais expressivas, no Brasil, observando que todas elas, na busca de um sentido, ultrapassam os conteúdos matemáticos. Neste trabalho, parodiando o texto de Guimarães, tomaremos tais tendências atuais do ensino da Matemática (a resolução de problemas, a modelagem, o construtivismo, a etnomatemática e o que David chama de um ensino comprometido com as transformações sociais, visando identificar nelas esse movimento de busca de um sentido para o ensinar matemática, por meio da re-inclusão daqueles mesmos elementos excluídos por Saussure da Lingüística, e negligenciados por abordagens mais tradicionais da matemática escolar. A análise procura apontar como essa busca de sentido no ensino da matemática trilha um percurso análogo ao que Guimarães identifica nos estudos da linguagem: o esforço de re-incluir na abordagem da matemática escolar aquilo que dela foi tradicionalmente excluído: o objeto, o sujeito e a história.In The Limits of Meaning (Os Limites do Sentido, 1995, Eduardo Guimarães analyzes the efforts to rescue the issue of meaning in linguistic studies as a movement to include in their object elements that Saussure had deliberately excluded: the subject, the world and the history. In the paper The possibilities for innovation in the teaching-learning of elementary mathematics (As possibilidades de inovação no ensino-aprendizagem da matemática elementar, 1995, Manuela David collects what she considered to be the most expressive trends in the current teaching of

  16. Toward a universal decoder of linguistic meaning from brain activation.

    Science.gov (United States)

    Pereira, Francisco; Lou, Bin; Pritchett, Brianna; Ritter, Samuel; Gershman, Samuel J; Kanwisher, Nancy; Botvinick, Matthew; Fedorenko, Evelina

    2018-03-06

    Prior work decoding linguistic meaning from imaging data has been largely limited to concrete nouns, using similar stimuli for training and testing, from a relatively small number of semantic categories. Here we present a new approach for building a brain decoding system in which words and sentences are represented as vectors in a semantic space constructed from massive text corpora. By efficiently sampling this space to select training stimuli shown to subjects, we maximize the ability to generalize to new meanings from limited imaging data. To validate this approach, we train the system on imaging data of individual concepts, and show it can decode semantic vector representations from imaging data of sentences about a wide variety of both concrete and abstract topics from two separate datasets. These decoded representations are sufficiently detailed to distinguish even semantically similar sentences, and to capture the similarity structure of meaning relationships between sentences.

  17. A separation-integrated cascade reaction to overcome thermodynamic limitations in rare-sugar synthesis.

    Science.gov (United States)

    Wagner, Nina; Bosshart, Andreas; Failmezger, Jurek; Bechtold, Matthias; Panke, Sven

    2015-03-27

    Enzyme cascades combining epimerization and isomerization steps offer an attractive route for the generic production of rare sugars starting from accessible bulk sugars but suffer from the unfavorable position of the thermodynamic equilibrium, thus reducing the yield and requiring complex work-up procedures to separate pure product from the reaction mixture. Presented herein is the integration of a multienzyme cascade reaction with continuous chromatography, realized as simulated moving bed chromatography, to overcome the intrinsic yield limitation. Efficient production of D-psicose from sucrose in a three-step cascade reaction using invertase, D-xylose isomerase, and D-tagatose epimerase, via the intermediates D-glucose and D-fructose, is described. This set-up allowed the production of pure psicose (99.9%) with very high yields (89%) and high enzyme efficiency (300 g of D-psicose per g of enzyme). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Investigation into the limitations of straightness interferometers using a multisensor-based error separation method

    Science.gov (United States)

    Weichert, Christoph; Köchert, Paul; Schötka, Eugen; Flügge, Jens; Manske, Eberhard

    2018-06-01

    The uncertainty of a straightness interferometer is independent of the component used to introduce the divergence angle between the two probing beams, and is limited by three main error sources, which are linked to each other: their resolution, the influence of refractive index gradients and the topography of the straightness reflector. To identify the configuration with minimal uncertainties under laboratory conditions, a fully fibre-coupled heterodyne interferometer was successively equipped with three different wedge prisms, resulting in three different divergence angles (4°, 8° and 20°). To separate the error sources an independent reference with a smaller reproducibility is needed. Therefore, the straightness measurement capability of the Nanometer Comparator, based on a multisensor error separation method, was improved to provide measurements with a reproducibility of 0.2 nm. The comparison results revealed that the influence of the refractive index gradients of air did not increase with interspaces between the probing beams of more than 11.3 mm. Therefore, over a movement range of 220 mm, the lowest uncertainty was achieved with the largest divergence angle. The dominant uncertainty contribution arose from the mirror topography, which was additionally determined with a Fizeau interferometer. The measured topography agreed within  ±1.3 nm with the systematic deviations revealed in the straightness comparison, resulting in an uncertainty contribution of 2.6 nm for the straightness interferometer.

  19. Ceramic membranes for high temperature hydrogen separation

    Energy Technology Data Exchange (ETDEWEB)

    Fain, D.E.; Roettger, G.E. [Oak Ridge K-25 Site, TN (United States)

    1996-08-01

    Ceramic gas separation membranes can provide very high separation factors if the pore size is sufficiently small to separate gas molecules by molecular sieving and if oversized pores are adequately limited. Ceramic membranes typically have some pores that are substantially larger than the mean pore size and that should be regarded as defects. To assess the effects of such defects on the performance of ceramic membranes, a simple mathematical model has been developed to describe flow through a gas separation membrane that has a primary mode of flow through very small pores but that has a secondary mode of flow through undesirably large pores. This model permits separation factors to be calculated for a specified gas pair as a function of the molecular weights and molecular diameters of the gases, the membrane pore diameter, and the diameter and number of defects. This model will be described, and key results from the model will be presented. The separation factors of the authors membranes continue to be determined using a permeance test system that measures flows of pure gases through a membrane at temperatures up to 275{degrees}C. A primary goal of this project for FY 1996 is to develop a mixed gas separation system for measuring the separation efficiency of membranes at higher temperatures. Performance criteria have been established for the planned mixed gas separation system and design of the system has been completed. The test system is designed to measure the separation efficiency of membranes at temperatures up to 600{degrees}C and pressures up to 100 psi by separating the constituents of a gas mixture containing hydrogen. The system will accommodate the authors typical experimental membrane that is tubular and has a diameter of about 9 mm and a length of about 23 cm. The design of the new test system and its expected performance will be discussed.

  20. Isotope separation system

    International Nuclear Information System (INIS)

    Lehmann, J.-C.

    1975-01-01

    A description is given of an isotope separation device comprising a system for converting into gaseous form a first and second isotope to be separated, a monochromatic excitation light source to excite the gaseous molecules of these two isotopes in a distinct manner, a first and second receiver to collect selectively the molecules of the first and second distinctly excited isotopes. The frequency FL of the excitation light is selected between a lower limit and a higher limit F2 + 1/2 LD, depending on the frequences F1 and F2 of two absorption lines near this first and second isotope. The difference DF between these two frequencies F1 and F2 is less than the Doppler width LD of each one of these lines and greater than the natural width LN of each of these two lines and also the width of line LR of the excitation light source. The probability that the molecules will be excited by this light depends on the direction of their displacement to a major and different extent for both isotopes. An ionising light source LI is set up to irradiate the seat of interaction between the excitation light and the gaseous molecules with an ionisation light able to ionise the excited molecules without ionising the molecules that are not excited. The receivers are able to collect selectively the ionised molecules. A sufficiently low gas pressure is selected for the distance between the place of interaction and the first receiver to be less than double the free mean travel of the molecules in the gas [fr

  1. Apparatus for diffusion separation

    International Nuclear Information System (INIS)

    Nierenberg, W.A.

    1976-01-01

    A diffuser separator apparatus is described which comprises a plurality of flow channels in a single stage. Each of said channels has an inlet port and an outlet port and a constant cross sectional area between said ports. At least a portion of the defining surface of each of said channels is a diffusion separation membrane, and each of said channels is a different cross sectional area. Means are provided for connecting said channels in series so that each successive channel of said series has a smaller cross sectional area than the previous channel of said series. Also provided are a source of gaseous mixture, individual means for flowing said gaseous mixture to the inlet port of each of said channels, gas receiving and analyzing means, individual means for flowing gas passing from each of said outlet ports and means for flowing gas passing through said membranes to said receiving and analyzing means, and individual means for connecting the outlet port of each channel with the inlet port of the channel having the next smaller cross sectional area

  2. Quantification of microangiopathic lesions in brain parenchyma and age-adjusted mean scores for the diagnostic separation of normal from pathological values in senile dementia

    International Nuclear Information System (INIS)

    Hentschel, F.; Kreis, M.; Damian, M.; Krumm, B.; Froelich, F.

    2005-01-01

    Purpose: to quantify microangiopathic lesions in the cerebral white matter and to develop age-corrected cut-off values for separating normal from dementia-related pathological lesions. Materials and methods: in a memory clinic, 338 patients were investigated neuropsychiatrically by a psychological test battery and by MRI. Using a FLAIR sequence and a newly developed rating scale, white matter lesions (WMLs) were quantified with respect to localization, number and intensity, and these ratings were condensed into a score. The WML scores were correlated with the mini-mental state examination (MMSE) and clinical dementia rating (CDR) score in dementia patients. A non-linear smoothing procedure was used to calculate age-related mean values and confidence intervals, separate for cognitively intact subjects and dementia patients. Results: the WML scores correlated highly significantly with age in cognitively intact subjects and with psychometric scores in dementia patients. Age-adjusted WML scores of cognitively intact subjects were significantly different from those of dementia patients with respect to the whole brain as well as to the frontal lobe. Mean value and confidence intervals adjusted for age significantly separated dementia patients from cognitively intact subjects over an age range of 54 through 84 years. Conclusion: a rating scale for the quantification of WML was validated and age-adjusted mean values with their confidence intervals for a diagnostically relevant age range were developed. This allows an easy to handle, fast and reliable diagnosis of the vascular component in senile dementia. (orig.)

  3. Limit of detection for the determination of Pt in biological material by RNAA using electrolytic separation of gold

    International Nuclear Information System (INIS)

    Xilei, L.; Heydorn, K.; Rietz, B.

    1992-01-01

    Neutron activation analysis based on the 199 Au indicator for platinum requires the separation of gold at high radiochemical purity. The limit of detection is strongly affected by the presence of gold; with a gold content of 50 pg/g, irradiating for 5 days at 5*10 13 n/cm 2 is needed to achieve a limit of detection of approximately 30 pg/g. In this case the nuclear interference from gold will exceeded the level of platium by several orders of magnitude and has to be determined with exceedingly high precision. Preliminary results for SRM 1577 Bovine Liver with 95% yield gave consistent results for Au, but Pt could not be detected. (author) 23 refs.; 3 figs.; 4 tabs

  4. Separation of parent homopolymers from diblock copolymers by liquid chromatography under limiting conditions of desorption 4. Role of eluent and temperature.

    Science.gov (United States)

    Berek, Dušan

    2010-11-01

    Liquid chromatography under limiting conditions of desorption (LC LCD) enables fast, base-line discrimination of both parent homopolymers from various diblock copolymers in one single step. The low molecular admixtures are fully separated, as well. General rules are discussed in detail for selection of mobile phases and temperature applied in LC LCD of block copolymers. Typical practical separation examples are presented. It is shown that both the composition of the well-selected LC LCD mobile phase and the temperature of experiment may vary in a broad range without affecting the basics of method. This implies that the method is robust and user friendly.

  5. Scenarios towards limiting global mean temperature increase below 1.5 °C

    Science.gov (United States)

    Rogelj, Joeri; Popp, Alexander; Calvin, Katherine V.; Luderer, Gunnar; Emmerling, Johannes; Gernaat, David; Fujimori, Shinichiro; Strefler, Jessica; Hasegawa, Tomoko; Marangoni, Giacomo; Krey, Volker; Kriegler, Elmar; Riahi, Keywan; van Vuuren, Detlef P.; Doelman, Jonathan; Drouet, Laurent; Edmonds, Jae; Fricko, Oliver; Harmsen, Mathijs; Havlík, Petr; Humpenöder, Florian; Stehfest, Elke; Tavoni, Massimo

    2018-04-01

    The 2015 Paris Agreement calls for countries to pursue efforts to limit global-mean temperature rise to 1.5 °C. The transition pathways that can meet such a target have not, however, been extensively explored. Here we describe scenarios that limit end-of-century radiative forcing to 1.9 W m-2, and consequently restrict median warming in the year 2100 to below 1.5 °C. We use six integrated assessment models and a simple climate model, under different socio-economic, technological and resource assumptions from five Shared Socio-economic Pathways (SSPs). Some, but not all, SSPs are amenable to pathways to 1.5 °C. Successful 1.9 W m-2 scenarios are characterized by a rapid shift away from traditional fossil-fuel use towards large-scale low-carbon energy supplies, reduced energy use, and carbon-dioxide removal. However, 1.9 W m-2 scenarios could not be achieved in several models under SSPs with strong inequalities, high baseline fossil-fuel use, or scattered short-term climate policy. Further research can help policy-makers to understand the real-world implications of these scenarios.

  6. Compliance of feed limits, does not mean compliance of food limits

    NARCIS (Netherlands)

    Raamsdonk, van L.W.D.; Eijkeren, van J.C.H.; Meijer, G.A.L.; Rennen, M.; Zeilmaker, M.J.; Hoogenboom, L.A.P.; Mengelers, M.J.B.

    2009-01-01

    The carry-over of contaminants from feed to animal food products is an important aspect of the animal production chain. For a proper containment, limits for feed as well food products are fixed for a series of chemicals, e.g. dioxins and dioxin-like PCBs, lead, cadmium, some chlorinated pesticides,

  7. Study of the isotopic contamination with the Grenoble isotope separator

    International Nuclear Information System (INIS)

    Boge, Marc

    1970-01-01

    To know the limits of enrichment of the Grenoble electromagnetic isotope separator, we have studied the scattering of ions on the residual gas, and the chromatism. With Neodymium (Nd + ≅ 500 μA, NdO + ≅ 120 μA, Nd 2+ ≅ 70 μA) the second magnet has been used to analyse the ions which passed through the first stage slit. Therefore, we have measured the scattering with and without charge exchange of Nd + and the dissociation of NdO + . The chromatism has been studied by means of an electrostatic analyser, as a third stage. The limits of enrichment are obtained for Argon, Uranium and Neodymium. (author) [fr

  8. The gas filled separator as a separation method to detect transuranic elements

    International Nuclear Information System (INIS)

    Ninov, V.

    1992-08-01

    The mass spectrometer NASE (NAchSEparator) built as a post-separator and located behind the velocity filter SHIP at the GSI in Darmstadt, was taken into operation as a gas-filled separator, and its separation properties for fusion products from heavy ion reactions were studied. Chapter 2 describes the principle of separation in a gas-filled magnet. The technical specifications of the separator, the detectors and the setup of detection electronics are outlined in chapter 3. The studies of separation properties are described in chapter 4, and chapter 5 deals with preliminary applications of the gas-filled separator to detect isotopes poor in neutrons, with an atomic number Z = 92, 93. Chapter 6 is concerned with preliminary tests to detect heavy nuclei with an atomic number Z > = 100 by means of light radiation and actinide targets. The experimental results of comparative measurements between the velocity filter SHIP and the gas-filled separator are pointed out in chapter 7, and future application possibilities of gas-filled separators for synthesis of heaviest nuclei through asymmetric reactions are discussed. (orig./BBR) [de

  9. Application of dry separative methods for decreasing content the residues unburned coal and separation Fe from black coal flies ash

    Directory of Open Access Journals (Sweden)

    František Kaľavský

    2008-06-01

    Full Text Available Main obstacle using of fly ashes in building, that is its main consumer, is the residue of unburned coal; it is expressed of loss onignition - LOI. In present, the valid STN and EU standard limits the content of LOI to 3 – 5 %, in national conditions maximum 7 %.Application of processing technologies also has to assure utilization of fly ash that provides a possibility of complex utilizationof individual products obtained by modification.By means of corona separation, based on different conductivity of individual fly ash elements, it is possible to separate unburnedcoal particles. The fly ash sample from black coal burning in melting boiler that was deposited on fly ash deposit, content of LOIof dielectric particle 6,45 % at 61 % weight yield was achieved. In the samples taken from dry taking of fly ash the non-conductingproduct contained 7,72 % of LOI at 73 % of weight yield.

  10. Separation of Hydrogen Isotopes by Palladium Alloy Membranes Separator

    International Nuclear Information System (INIS)

    Jiangfeng, S.; Deli, L.; Yifu, X.; Congxian, L.; Zhiyong, H.

    2007-01-01

    Full text of publication follows: Separation of hydrogen isotope with palladium alloy membranes is one of the promising methods for hydrogen isotope separation. It has several advantages, such as high separation efficiency, smaller tritium inventory, simple separation device, ect. Limited by the manufacture of membrane and cost of gas transportation pump, this method is still at the stage of conceptual study. The relationship between separation factors and temperatures, feed gas components, split ratios have not been researched in detail, and the calculated results of cascade separation have not been validated with experimental data. In this thesis, a palladium alloy membrane separator was designed to further study its separation performance between H 2 and D 2 . The separation factor of the single stage was affected by the temperature, the feed gas component, the split ratio and the gas flow rate, etc. The experimental results showed that the H 2 -D 2 separation factor decreased with the increasing of temperature. On the temperature from 573 K to 773 K, when the feed rate was 5 L/min, the separation factor of 66.2%H 2 - 33.8%D 2 decreased from 2.09 to 1.85 when the split ratio was 0.1 and from 1.74 to 1.52 when the split ratio was 0.2.The separation factor also decreased with the increasing of split ratio. At 573 K and the feed rate of 5 L/min, the separation factor of 15.0%H 2 and 85.0%D 2 decreased from 2.43 to 1.35 with the increasing of split ratio from 0.050 to 0.534,and for 66.2%H 2 -33.8%D 2 , the separation factor decreased from 2.87 to 1.30 with the increasing of split ratio from 0.050 to 0.688. When the separation factor was the biggest, the flow rate of feed gas was in a perfect value. To gain a best separation performance, perfect flow rate, lower temperature and reflux ratio should be chosen. (authors)

  11. The determination of long life radionuclides by means of sector field ICP mass spectrometry

    International Nuclear Information System (INIS)

    Kerl, W.; Becker, J.S.; Dietze, H.J.; Dannecker, W.

    1996-01-01

    Different analytical processes for determining long life radionuclides by means of double-focussing sector field ICP mass spectrometry are described. In determining long life radionuclides by means of ICP-MS, on the one hand the analytical problem areas are in the interference of isobaric atom or molecule ions (eg: 151 Eu + - 151 Sm + , 79 Se + - 39 Ar 40 ArH + ) and on the other hand in the high detection limits when using commercial sample introduction systems (eg: For 129 I). An online coupling of HPLC and ICP-MS was built up for the separation of isobaric atom ions and was tested for the separation of isobaric atom ions and was tested for its efficiency in the separation of lanthanides. Special sample introduction systems for ICP-MS were developed for the analysis of 129 I, by which the sensitivity of detection can be appreciably improved compared to commercial sample introduction systems. (orig.) [de

  12. The selective conversion of glutamic acid in amino acid mixtures using glutamate decarboxylase--a means of separating amino acids for synthesizing biobased chemicals.

    Science.gov (United States)

    Teng, Yinglai; Scott, Elinor L; Sanders, Johan P M

    2014-01-01

    Amino acids (AAs) derived from hydrolysis of protein rest streams are interesting feedstocks for the chemical industry due to their functionality. However, separation of AAs is required before they can be used for further applications. Electrodialysis may be applied to separate AAs, but its efficiency is limited when separating AAs with similar isoelectric points. To aid the separation, specific conversion of an AA to a useful product with different charge behavior to the remaining compounds is desired. Here the separation of L-aspartic acid (Asp) and L-glutamic acid (Glu) was studied. L-Glutamate α-decarboxylase (GAD, Type I, EC 4.1.1.15) was applied to specifically convert Glu into γ-aminobutyric acid (GABA). GABA has a different charge behavior from Asp therefore allowing a potential separation by electrodialysis. Competitive inhibition and reduced operational stability caused by Asp could be eliminated by maintaining a sufficiently high concentration of Glu. Immobilization of GAD does not reduce the enzyme's initial activity. However, the operational stability was slightly reduced. An initial study on the reaction operating in a continuous mode was performed using a column reactor packed with immobilized GAD. As the reaction mixture was only passed once through the reactor, the conversion of Glu was lower than expected. To complete the conversion of Glu, the stream containing Asp and unreacted Glu might be recirculated back to the reactor after GABA has been removed. Overall, the reaction by GAD is specific to Glu and can be applied to aid the electrodialysis separation of Asp and Glu. © 2014 American Institute of Chemical Engineers.

  13. Chromatography on cellulose exchangers: microdetermination of Fe/sup 3 +/, UO/sub 2//sup 2 +/, and Cu/sup 2 +/ ions in aqueous solutions by means of small separation columns

    Energy Technology Data Exchange (ETDEWEB)

    Burba, P; Lieser, K H

    1978-01-01

    A study of the use of small separation columns filled with a cellulose exchanger containing salicylic acid as the anchor group for chromatographic determination of Fe/sup 3 +/ and Cu/sup 2 +/ in aqueous solution is described. The detection limits are Fe approx.0.2 and Cu 10 ..mu..g. The separation and simultaneous determination of several ions is possible.

  14. Separating oil from water

    Energy Technology Data Exchange (ETDEWEB)

    Webb, C

    1991-04-11

    The technology available to deal with oil spills has assumed many new faces in recent years. Methods of dealing with small-scale pollution in the process industries and vast oil slicks such as that in the Gulf have developed in parallel. The progress being made in finding new means of separating oil from water is reported and the relative merits of bioremediation, hydrocylones, horizontal separators and gas flotation are discussed. (author).

  15. Acoustic bubble enhanced pinched flow fractionation for microparticle separation

    International Nuclear Information System (INIS)

    Zhou, Ran; Wang, Cheng

    2015-01-01

    Pinched flow fractionation is a simple method for separating micron-sized particles by size, but has certain intrinsic limitations, e.g. requirement of a pinched segment similar to particle size and limited separation distance. In this paper, we developed an acoustic bubble enhanced pinched flow fractionation (PFF) method for microparticle separation. The proposed technique utilized microbubble streaming flows to overcome the limitations of conventional PFF. Our device has demonstrated separation of different sized microparticles (diameters 10 and 2 μm) with a larger pinched segment (60 μm) and at different buffer/particle solution flow rate ratios (5–25). The separation distances between particles are larger (as much as twice as large) than those achieved with conventional PFF. In addition, the separation position and distance can be adjusted by changing the driving voltage. The robust performance is due to the unique features of the flow field inside the pinched segment. We investigated several factors, including flow rate ratio, total flow rate and driving voltage, that affect the separation performance. (paper)

  16. Isotope separation process

    International Nuclear Information System (INIS)

    1976-01-01

    The invention relates to a process for separating a given material into two or more parts, in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in the said material. More particularly, the invention relates to a method for the isotopically selective excitation of gas phase UF 6 by infrared photon absorption followed by selective reaction of said excited UF 6 with atomic chlorine, bromine, or iodine to form a product which may be separated by means known in the art

  17. Separation of the constituents of coal

    Energy Technology Data Exchange (ETDEWEB)

    Betrand, M F

    1938-12-06

    A process is disclosed of separating, by means of dense aqueous solutions, the constituents of coal, isolated by preliminary crushing from each other and/or from barren and carbonaceous shales, comprising the addition to the washing water before treatment or during any stage of the preparation of the coal before separation, or to the dense separating solution of agents improving the wetting of the coal by water.

  18. Study on rare earths complexes separation by means of different type of ion exchangers

    International Nuclear Information System (INIS)

    Hubicka, H.

    1990-01-01

    The applicability of different types of ion exchangers for purification and separation of rare earths complexes has been examined. The experimental work has been carried out on 14 chelating ion exchangers. The investigation results proved the great usefulness chelating ion exchangers especially of amino acid and phosphorus-type. Application of that type ion exchangers in column chromatographic process gave the excellent rare earths separation as well as enabled to obtain their preparates of high purity. 218 refs, 21 figs, 27 tabs

  19. Tissue free water tritium separation from foodstuffs by azeotropic distillation

    International Nuclear Information System (INIS)

    Constantin, F.; Ciubotaru, A.; Popa, D.

    1998-01-01

    In this paper the tritium separation from tissue free water in foodstuffs by azeotropic distillation is described. Tritium in tissue water is assayed by liquid scintillation counting using well-established quenched correction method. The mean value of the tritium concentration in tissue water from foodstuffs is about 6-12 Bq/l very similar to the tritium mean concentration measured in the surface waters of the area where the samples have been collected (about 12 Bq/l. Therefore, the tritium content in the water fraction of the food samples can be considered in equilibrium with the local environmental water sources. The azeotropic distillation it is an accessible separation method which does not need a sophisticated and expansive distillation apparatus. It is a fast method of separation tissue free water from foodstuffs being very important in the surveillance activity of the environmental within nuclear electric plant. It is suitable for processing a small quantity of samples and for a production type facility when a large number of samples must be processed because the solvent can be purified and reused. The azeotropic distillation has some limits being used to separate water from samples with high content of water (85-90%) and simple a simple chemical structures as: vegetables, fruits, cereal, soil, vegetation. According to the results obtained, the organic substituents of milk, wine, meat (casein, lactose, milk fat, alcohol, esters) may enhance the chemisorption of tritium on through exchange organic hydrogen as -OH, -SH, -NH, -COOH with tritium. Also, the tissue water separation by azeotropic distillation is not complete and can not guarantee the absence of the vaporization isotope effect of the HTO/H 2 O system., However, the azeotropic distillation is the preferred method of the water extraction from food samples, which makes it useful for the tritium transfer from soil to foodstuffs. (authors)

  20. Tissue free water tritium separation from foodstuffs by azeotropic distillation

    Energy Technology Data Exchange (ETDEWEB)

    Constantin, F; Ciubotaru, A; Popa, D [Inspectorate of Public Health of Bucharest (Romania)

    1999-12-31

    In this paper the tritium separation from tissue free water in foodstuffs by azeotropic distillation is described. Tritium in tissue water is assayed by liquid scintillation counting using well-established quenched correction method. The mean value of the tritium concentration in tissue water from foodstuffs is about 6-12 Bq/l very similar to the tritium mean concentration measured in the surface waters of the area where the samples have been collected (about 12 Bq/l. Therefore, the tritium content in the water fraction of the food samples can be considered in equilibrium with the local environmental water sources. The azeotropic distillation it is an accessible separation method which does not need a sophisticated and expansive distillation apparatus. It is a fast method of separation tissue free water from foodstuffs being very important in the surveillance activity of the environmental within nuclear electric plant. It is suitable for processing a small quantity of samples and for a production type facility when a large number of samples must be processed because the solvent can be purified and reused. The azeotropic distillation has some limits being used to separate water from samples with high content of water (85-90%) and simple a simple chemical structures as: vegetables, fruits, cereal, soil, vegetation. According to the results obtained, the organic substituents of milk, wine, meat (casein, lactose, milk fat, alcohol, esters) may enhance the chemisorption of tritium on through exchange organic hydrogen as -OH, -SH, -NH, -COOH with tritium. Also, the tissue water separation by azeotropic distillation is not complete and can not guarantee the absence of the vaporization isotope effect of the HTO/H{sub 2}O system., However, the azeotropic distillation is the preferred method of the water extraction from food samples, which makes it useful for the tritium transfer from soil to foodstuffs. (authors) 2 tabs.

  1. LQG Control of Networked Control Systems with Limited Information

    Directory of Open Access Journals (Sweden)

    Qing-Quan Liu

    2014-01-01

    Full Text Available This paper addresses linear quadratic Gaussian (LQG control problems for multi-input multioutput (MIMO, linear time-invariant (LTI systems, where the sensors and controllers are geographically separated and connected via a digital communication channel with limited data rates. An observer-based, quantized state feedback control scheme is employed in order to achieve the minimum data rate for mean square stabilization of the unstable plant. An explicit expression is presented to state the tradeoff between the LQ cost and the data rate. Sufficient conditions on the data rate for mean square stabilization are derived. An illustrative example is given to demonstrate the effectiveness of the proposed scheme.

  2. Separation of gas mixtures

    International Nuclear Information System (INIS)

    1981-01-01

    Apparatus is described for the separation of a gaseous plasma mixture into components in some of which the original concentration of a specific ion has been greatly increased or decreased, comprising: a source for converting the gaseous mixture into a train of plasma packets; an open-ended vessel with a main section and at least one branch section, adapted to enclose along predetermined tracks the original plasma packets in the main section, and the separated plasma components in the branch sections; drive means for generating travelling magnetic waves along the predetermined tracks with the magnetic flux vector of the waves transverse to each of the tracks; and means for maintaining phase coherence between the plasma packets and the magnetic waves at a value needed for accelerating the components of the packets to different velocities and in such different directions that the plasma of each packet is divided into distinctly separate packets in some of which the original concentration of a specific ion has been greatly increased or decreased, and which plasma packets are collected from the branch sections of the vessels. (author)

  3. Apparatus for extraction and separation of a preferentially photo-dissociated molecular isotope into positive and negative ions by means of an electric field

    International Nuclear Information System (INIS)

    Fletcher, J.C.

    1978-01-01

    Apparatus for the separation and extraction of molecular isotopes is claimed. Molecules of one and the same isotope are preferentially photo-dissociated by a laser and an ultraviolet source, or by multi-photon absorption of laser radiation. The resultant ions are confined with a magnetic field, moved in opposite directions by an electric field, extracted from the photo-dissociation region by means of screening and accelerating grids, and collected in ducts

  4. Amino acids separation with the tetracarboxylic derived of the para-ter-butylcalix[4]arene by means of solid-liquid extraction assisted with lanthanides

    International Nuclear Information System (INIS)

    Bernal R, R. del C.

    2014-01-01

    The tetracarboxylic derived of the para-ter-butylcalix[4]arene (B 4 ACEbL 4 ) does not exist commercially for what was synthesized and characterized at laboratory level. The separation of the L-tyrosine amino acid was studied by means of a solid-liquid extraction system with the B 4 ACEbL 4 as solid phase, in function of ph (2.5-7.5) and contact time (5 and 15 hours) to temperature of 15-17 grades C. Resulted that the ph and the contact time were decisive in the extraction percentage of water tyrosine. The lowest percentage was 49% to ph 4 and the highest percentage was 61% to ph 7.5 with 15 hours of contact. In a contact time of 5 hours the extraction was inferior to 32% (ph 4) and of 47% to ph 6.5. The europium effect (Eu (III)) was studied to ph acid in the tyrosine separation and was found that the tyrosine extraction is not increased neither decomposes in europium presence, this is simultaneously extracted by the calixarene but it does not enter in competition for the calixarene with the amino acid. The separate solid phases: calixarene-tyrosine was analyzed by Far infrared radiation (Fir), Mid-Infrared (Mir) spectroscopy and luminescence to check the tyrosine presence in the separate solids as well as the nature of the connection calixarene-tyrosine. In this way was possible to check the tyrosine presence and to propose the formed molecular species tyrosine-calixarene, those which interact mainly by means of hydrogen connections and Van der Waals forces. The liquid phases before and after the extraction were analyzed by UV-Vis spectrophotometry and luminescence. The Neutron activation analysis was used to determine the europium content in the solid and liquid phases of extractions in europium presence. The tyrosine degradation also shows dependence with the ph, obtaining 88% degradation to the 24 hours to ph 7.5, while to ph 3 is degraded the 54% of tyrosine present in the sample. The europium presence does not affect the tyrosine extraction but if its photo

  5. Dose limits, constraints, reference levels. What does it mean for radiation protection?; Grenzwerte, Richtwerte, Referenzwerte. Was bedeutet das fuer den Strahlenschutz

    Energy Technology Data Exchange (ETDEWEB)

    Breckow, J. [Technische Hochschule Mittelhessen (THM), Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz (IMPS)

    2016-07-01

    The established concept of radiation protection with its basic principles justification, optimization, and limitation has proved its value and is going to be continued. In its deeper meaning, however, the concept is rather subtle and complex. Furthermore, in some aspects there remain some breaches or inconsistencies. This is just true for the terms dose limit, reference lever, and constraint that are tightly associated with the radiation protection principles. In order to guarantee the ability of radiation protection in whole extent, the subtle differences of meaning have to be communicated. There is a permanent need to defend the conceptual function of these terms against deliberate or undeliberate misinterpretations. Reference levels are definitely not the same as dose limits and they may not be misused as such. Any attempt to misinterpret fundamental radiation protection principles for selfish purposes should discouraged vigorously.

  6. Separation of CO{sub 2}/N{sub 2} by means of a carbon membrane

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Y.; Braun, G. [Cologne University of Applied Sciences, Cologne (Germany); Kaltenborn, N.; Voigt, I. [Fraunhofer Institute for Ceramic Technologies and Systems, IKTS, Hermsdorf (Germany); Brunner, G. [Hamburg University of Technology (TUHH), Hamburg (Germany)

    2012-03-15

    The permeation and separation performance of an ultramicroporous carbon membrane for separation of CO{sub 2}/N{sub 2} mixtures were investigated. The experiments were conducted using the steady-state measurement method with pure gases (dead-end mode) and a CO{sub 2}/N{sub 2} gas mixture (20/80 mol.-%) (cross-flow mode) in the temperature range from 293 K to 363 K and at feed pressures of up to 1.4 MPa and atmospheric pressure on the permeate side. The membrane exhibited a selectivity of about 25 and permeability of about 500 Barrer for CO{sub 2} in the mixture with N{sub 2}. The single-gas measurements do not reflect the membrane performance correctly. An adsorption-selective effect is assumed to be the main separation mechanism. Moreover, membrane-aging effects causing blocking due to pore constrictions through adsorption were observed. These pore constrictions lower the permeability, but they raise the selectivity. Operation at high temperatures leads to a reduction of aging effects. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Brand Meaning Cocreation

    DEFF Research Database (Denmark)

    Tierney, Kieran D.; Karpen, Ingo; Westberg, Kate

    2016-01-01

    Purpose: The purpose of this paper is to consolidate and advance the understanding of brand meaning and the evolving process by which it is determined by introducing and explicating the concept of brand meaning cocreation (BMCC). Design/methodology/approach: In-depth review and integration...... of literature from branding, cocreation, service systems, and practice theory. To support deep theorizing, the authors also examine the role of institutional logics in the BMCC process in framing interactions and brand meaning outcomes. Findings: Prior research is limited in that it neither maps the process...... of cocreation within which meanings emerge nor provides theoretical conceptualizations of brand meaning or the process of BMCC. While the literature acknowledges that brand meaning is influenced by multiple interactions, their nature and how they contribute to BMCC have been overlooked. Research limitations...

  8. Separable quadratic stochastic operators

    International Nuclear Information System (INIS)

    Rozikov, U.A.; Nazir, S.

    2009-04-01

    We consider quadratic stochastic operators, which are separable as a product of two linear operators. Depending on properties of these linear operators we classify the set of the separable quadratic stochastic operators: first class of constant operators, second class of linear and third class of nonlinear (separable) quadratic stochastic operators. Since the properties of operators from the first and second classes are well known, we mainly study the properties of the operators of the third class. We describe some Lyapunov functions of the operators and apply them to study ω-limit sets of the trajectories generated by the operators. We also compare our results with known results of the theory of quadratic operators and give some open problems. (author)

  9. Centrifugal separator. [for production of enriched U

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, J; Fujita, S I

    1970-02-25

    In a centrifugal separator of the concurrent flow through type, a rotating member having an inner and outer cylinder with an air gap therebetween is supported within a frame. A mixture to be separated is supplied to the interior of the inner cylinder through a hollow shaft inserted coaxially within the rotatable portion of a driving apparatus, with one end of the rotatable portion attached to the common inlet end cap of the cylinders which are thereby rotated. There are provided holes at the upper end of the inner cylinder through which the mixture enters the air gap to undergo separation, with the thus separated lighter component entering a separate chamber at the lower end of the inner cylinder through holes provided therein to thereafter be discharged from the outlet end thereof, while the heavier component is discharged from the outlet end of the outer cylinder through holes provided therein. The separated gases then enter their respective chambers within the frame for final removal where they are isolated from each other by sealing means to prevent remixture. Efficiency is heightened and, since no other complicated means are necessary for dividing and removing the separated components, the structure of the present centrifuge can be simplified and reduced in size.

  10. Unsupervised Cryo-EM Data Clustering through Adaptively Constrained K-Means Algorithm.

    Science.gov (United States)

    Xu, Yaofang; Wu, Jiayi; Yin, Chang-Cheng; Mao, Youdong

    2016-01-01

    In single-particle cryo-electron microscopy (cryo-EM), K-means clustering algorithm is widely used in unsupervised 2D classification of projection images of biological macromolecules. 3D ab initio reconstruction requires accurate unsupervised classification in order to separate molecular projections of distinct orientations. Due to background noise in single-particle images and uncertainty of molecular orientations, traditional K-means clustering algorithm may classify images into wrong classes and produce classes with a large variation in membership. Overcoming these limitations requires further development on clustering algorithms for cryo-EM data analysis. We propose a novel unsupervised data clustering method building upon the traditional K-means algorithm. By introducing an adaptive constraint term in the objective function, our algorithm not only avoids a large variation in class sizes but also produces more accurate data clustering. Applications of this approach to both simulated and experimental cryo-EM data demonstrate that our algorithm is a significantly improved alterative to the traditional K-means algorithm in single-particle cryo-EM analysis.

  11. Ironies and Limitations of Educational Leadership for Social Justice: A Call to Social Justice Educators

    Science.gov (United States)

    Capper, Colleen A.; Young, Michelle D.

    2014-01-01

    In this article that reviews this special issue, we identify 5 ironies and limitations of educational leadership for social justice: (a) the meaning of inclusive practice, (b) the intersection of identity and difference, (c) the emphasis given to student achievement, (d) the lack of policy and practice coherence, and (e) the separation of…

  12. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.

    1976-01-01

    The instant invention relates to a process for separating a material into two or more parts in each of which the abundances of the isotopes of a given element differ from the abundances of the isotopes of the same material in said material. In one embodiment, the invention relates to a method for the isotopically selective excitation of gas phase molecules by multiple infrared photon absorption followed by selective dissociation of said excited molecules by the absorption of a single photon of visible or ultraviolet light. This invention is useful for, but not limited to, the separation of the principal isotopes of uranium. 11 Claims, 2 Drawing Figures

  13. Normalization based K means Clustering Algorithm

    OpenAIRE

    Virmani, Deepali; Taneja, Shweta; Malhotra, Geetika

    2015-01-01

    K-means is an effective clustering technique used to separate similar data into groups based on initial centroids of clusters. In this paper, Normalization based K-means clustering algorithm(N-K means) is proposed. Proposed N-K means clustering algorithm applies normalization prior to clustering on the available data as well as the proposed approach calculates initial centroids based on weights. Experimental results prove the betterment of proposed N-K means clustering algorithm over existing...

  14. In Situ Magnetic Separation for Extracellular Protein Production

    DEFF Research Database (Denmark)

    Kappler, T.; Cerff, Martin; Ottow, Kim Ekelund

    2009-01-01

    A new approach for in situ product removal from bioreactors is presented in which high-gradient magnetic separation is used. This separation process was used for the adsorptive removal of proteases secreted by Bacillus licheniformis. Small, non-porous bacitracin linked magnetic adsorbents were...... was not influenced by the in situ product removal step. Protease production also remained the same after the separation step. Furthermore, degradation of the protease, which followed first order kinetics, was reduced by using the method. Using a theoretical modeling approach, we Could show that protease yield...... in total was enhanced by using in situ magnetic separation. The process described here is a promising technique to improve overall yield in No production processes which are often limited due to weak downstream operations, Potential limitations encountered during a bioprocess can be overcome...

  15. Separation of gases

    International Nuclear Information System (INIS)

    Wang, C.G.

    1980-01-01

    A process for separating gaseous mixtures of molecules of different mass comprises the steps of: causing a rotational nozzle to eject a contiguous plurality of successive groups of molecules into an evacuated space, the groups mutually overlapping to form a continuous stream of the mixture in the form of an Archimedean spiral, allowing the molecules of each group of molecules to move in accordance with their thermal velocities for a predetermined period of time following ejection, thereby to allow each group of molecules to form a generally spherical configuration the outer portion of which will be enriched, in molecules of lighter mass, relative to the inner portion thereof, using a deflector means co-rotating with the rotating nozzle to deflect molecules, which have been allowed to move for the predetermined period of time in accordance with their thermal velocities, from at least one desired portion of the stream and using a stationary collector means to collect the deflected molecules. The process is described with reference to the separation of isotopes of uranium hexafluoride. (author)

  16. Radiation gradient isotope separator

    International Nuclear Information System (INIS)

    Hughes, J.L.

    1980-01-01

    A system is described for transporting, separating and storing charged particles, charged antiparticles and fully or partially ionized isotopes of any element comprising a laser beam generator, laser beam intensity profiler, a laser beam variable intensity attenuator, and means for injecting charged particles, charged antiparticles and ionized isotopes into the beam and extracting them from the system as required. The invention is particularly useful for channelling electrons and ions used for fuel pellet compression in inertial fusion systems, for separating the isotopes of elements and for the confinement of charged antiparticles and particle/antiparticle plasmas

  17. Optics of mass separator I

    International Nuclear Information System (INIS)

    Balestrini, S.J.

    1981-07-01

    The ion optics of an existing mass separator are documented. The elctrostatic and magnetic stages are analyzed theoretically, both separately and in combination, by paying particular attention to the ion trajectories, the linear and angular magnifications, and the dispersion. The possibility of converting the magnet into a tunable unit by means of current-carrying elements in the gap is demonstrated. The feasibility of correction coils constructed from printed circuit board is shown

  18. Optics of mass separator I

    Energy Technology Data Exchange (ETDEWEB)

    Balestrini, S.J.

    1981-07-01

    The ion optics of an existing mass separator are documented. The elctrostatic and magnetic stages are analyzed theoretically, both separately and in combination, by paying particular attention to the ion trajectories, the linear and angular magnifications, and the dispersion. The possibility of converting the magnet into a tunable unit by means of current-carrying elements in the gap is demonstrated. The feasibility of correction coils constructed from printed circuit board is shown.

  19. Means of control of the public authorities as participants in public limited energy supply companies

    International Nuclear Information System (INIS)

    Kermel, C.

    1994-01-01

    Despite the fundamental studies by Emmerich and Puettner, the control of publicly owned companies by the state as a majority shareholder has not evolved to a generally accepted form. With a mind to the discussion on a nuclear phase-out at Hamburgische Electrizitaetswerke AG the author examines the scope offered by the law on public limited companies for realising the interests of the state as a shareholder. She arrives at interesting conclusions regarding the means to this end and the legal consequences of a phase-out decision. Lower supply companies are an ideal object of study for the purposes of this work. (orig./UA) [de

  20. Flow-induced separation in wall turbulence.

    Science.gov (United States)

    Nguyen, Quoc; Srinivasan, Chiranth; Papavassiliou, Dimitrios V

    2015-03-01

    One of the defining characteristics of turbulence is its ability to promote mixing. We present here a case where the opposite happens-simulation results indicate that particles can separate near the wall of a turbulent channel flow, when they have sufficiently different Schmidt numbers without use of any other means. The physical mechanism of the separation is understood when the interplay between convection and diffusion, as expressed by their characteristic time scales, is considered, leading to the determination of the necessary conditions for a successful separation between particles. Practical applications of these results can be found when very small particles need to be separated or removed from a fluid.

  1. The Role of the New Zealand Plateau in the Tasman Sea Circulation and Separation of the East Australian Current

    Science.gov (United States)

    Bull, Christopher Y. S.; Kiss, Andrew E.; van Sebille, Erik; Jourdain, Nicolas C.; England, Matthew H.

    2018-02-01

    The East Australian Current (EAC) plays a major role in regional climate, circulation, and ecosystems, but predicting future changes is hampered by limited understanding of the factors controlling EAC separation. While there has been speculation that the presence of New Zealand may be important for the EAC separation, the prevailing view is that the time-mean partial separation is set by the ocean's response to gradients in the wind stress curl. This study focuses on the role of New Zealand, and the associated adjacent bathymetry, in the partial separation of the EAC and ocean circulation in the Tasman Sea. Here utilizing an eddy-permitting ocean model (NEMO), we find that the complete removal of the New Zealand plateau leads to a smaller fraction of EAC transport heading east and more heading south, with the mean separation latitude shifting >100 km southward. To examine the underlying dynamics, we remove New Zealand with two linear models: the Sverdrup/Godfrey Island Rule and NEMO in linear mode. We find that linear processes and deep bathymetry play a major role in the mean Tasman Front position, whereas nonlinear processes are crucial for the extent of the EAC retroflection. Contrary to past work, we find that meridional gradients in the basin-wide wind stress curl are not the sole factor determining the latitude of EAC separation. We suggest that the Tasman Front location is set by either the maximum meridional gradient in the wind stress curl or the northern tip of New Zealand, whichever is furthest north.

  2. Separation of short-lived fission products

    International Nuclear Information System (INIS)

    Tamai, Tadaharu; Ohyoshi, Emiko; Ohyoshi, Akira; Kiso, Yoshiyuki; Shinagawa, Mutsuaki.

    1976-01-01

    A rbief review is presented on the various methods of separation available for both gaseous and liquid states, for the separation of short-lived fission products formed by binary fission of neutron irradiated uranium. The means available for gaseous state are the hot atom reaction, the hydride method and on-line mass separation. For liquid state, use can be made of precipitation, ionic or atomic exchange, solvent extraction and paper electrophoresis. Particular reference is made to electrophoretic separation of ions produced by fission in aqueous solution of uranium. The principle of electrophoretic separation and the procedures for separating the element of interest from the other fission products are outlined, with reference made to the results obtained with the method by the present authors. The elements in question are alkalines, alkaline earths, rare earths, halogens, selenium and

  3. Evaluation of core compositions for use in breed and burn reactors and limited-separations fuel cycles

    International Nuclear Information System (INIS)

    Petroski, Robert; Forget, Benoit; Forsberg, Charles

    2013-01-01

    Highlights: ► Calculated minimum burnup and irradiation damage for B and B reactor compositions. ► Computed doubling time of fuel cycles using B and B reactors and no chemical separations. ► Determined sensitivity of doubling time to using melt refining vs. direct reuse. ► Examined tradeoff between power density and neutronics for different coolants. - Abstract: Previously developed methods for analyzing breed-and-burn (B and B) reactors are applied to a wide range of core compositions. The compositions studied include different fuel types, steel and silicon carbide structure, and sodium, lead/lead bismuth eutectic (LBE), and gas coolants. These compositions are evaluated for use in “minimum burnup” B and B reactors in which it is assumed that blocks comprising the core can be shuffled in all three dimensions to flatten out non-uniformities in burnup. The two figures of merit evaluated are the minimum irradiation damage requirement and reactor fleet doubling time. To minimize irradiation damage, gas coolants perform best, followed by lead/LBE then sodium. High uranium-content metal fuel outperforms compound fuels, and different types of steel are similar and perform slightly better than silicon carbide. Once-through irradiation damage requirements can be surprisingly modest in minimum burnup B and B reactors, with a wide range of compositions viable at irradiation damage levels 50% higher than existing materials data. Doubling times were calculated for a reactor fleet consisting of B and B reactors operating in a limited-separations fuel cycle; i.e., a fuel cycle with no chemical separation of actinides. The effects of different cooling times and removal of fission products using a melt refining process are evaluated. To minimize doubling time, sodium cooled compositions perform best because they are able to achieve core power densities several times larger than compositions using other coolants. A hypothetical sodium-cooled core composition with high

  4. Development of a relatively cheap and simple automated separation system for a routine separation procedure based on extraction chromatography

    International Nuclear Information System (INIS)

    Petro Zoriy; Reinhold Flucht; Mechthild Burow; Peter Ostapczuk; Reinhard Lennartz; Myroslav Zoriy

    2010-01-01

    A robust analytical method has been developed in our laboratory for the separation of radionuclides by means of extraction chromatography using an automated separation system. The proposed method is both cheap and simple and provides the advantageous, rapid and accurate separation of the element of interest. The automated separation system enables a shorter separation time by maintaining a constant flow rate of solution and by avoiding clogging or bubbling in the chromatographic column. The present separation method was tested with two types of samples (water and urine) using UTEVA-, TRU- and Sr-specific resins for the separation of U, Th, Am, Pu and Sr. The total separation time for one radionuclide ranged from 60 to 100 min with the separation yield ranging from 68 to 98% depending on the elements separated. We used ICP-QMS, multi-low-level counter and alpha spectroscopy to measure the corresponding elements. (author)

  5. A quantitative assessment of the scale separation limits of classical and higher-order asymptotic homogenization

    NARCIS (Netherlands)

    Mohammed Ameen, M.; Peerlings, R.H.J.; Geers, M.G.D.

    2018-01-01

    Classical homogenization techniques are known to be effective for materials with large scale separation between the size and spacing of their underlying heterogeneities on the one hand and the structural problem dimensions on the other. For low scale separation, however, they generally become

  6. Facility to separate water and steam

    International Nuclear Information System (INIS)

    Loesel, G.

    1977-01-01

    The water/steam mixture from the pressure vessel e.g. of a BWR is separated by means of centrifugal separators untilizing the natural separation of steam. The steam is supplied to a steam drying vessel and the water to a water collecting tank. These vessels may be combined to a common vessel or connected through additional pipes. From the water collecting tank, arranged below the steam dryer, a feedwater pipe runs back to the pressure vessel. By construction out of individual components cleaning, decontamination, and operating control are essentially simplified. (RW) 891 RW [de

  7. The separation of heavy ion tracks in nuclear emulsions by means of the pulsed electric field

    International Nuclear Information System (INIS)

    Akopova, A.B.; Magradze, N.V.; Melkumyan, L.V.; Prokhorenko, Y.P.

    1976-01-01

    The pulsed electric field (PEF) technique is developed for the separation of heavy ion tracks from the intense background caused by high energy electrons, protons and γ-radiation. The tracks of Ne, Cr, Ar-ions accelerated at the Dubna Nuclear Reactions Laboratory have been separated from the background, the voltage of the applied PEF being 10 5 V/cm. (orig.) [de

  8. Inductive Sensor Performance in Partial Discharges and Noise Separation by Means of Spectral Power Ratios

    Directory of Open Access Journals (Sweden)

    Jorge Alfredo Ardila-Rey

    2014-02-01

    Full Text Available Partial discharge (PD detection is a standardized technique to qualify electrical insulation in machines and power cables. Several techniques that analyze the waveform of the pulses have been proposed to discriminate noise from PD activity. Among them, spectral power ratio representation shows great flexibility in the separation of the sources of PD. Mapping spectral power ratios in two-dimensional plots leads to clusters of points which group pulses with similar characteristics. The position in the map depends on the nature of the partial discharge, the setup and the frequency response of the sensors. If these clusters are clearly separated, the subsequent task of identifying the source of the discharge is straightforward so the distance between clusters can be a figure of merit to suggest the best option for PD recognition. In this paper, two inductive sensors with different frequency responses to pulsed signals, a high frequency current transformer and an inductive loop sensor, are analyzed to test their performance in detecting and separating the sources of partial discharges.

  9. Method to separate various isotopes in compounds by means of laser radiation

    International Nuclear Information System (INIS)

    Meyer-Kretschmer, G.; Jetter, H.; Toennies, P.

    1980-01-01

    The uranium hexafluoride together with an inert addition gas is cooled down below 50 K by adiabatic expansion, then the state of oscillation of the molecules is changed specifically for each isotope using laser light, and subsequently positive ions are produced by means of an electron beam. The ions are removed from the gas by means of an electric field. (DG) [de

  10. What the new EPA (Environmental Protection Agency) rules mean

    Energy Technology Data Exchange (ETDEWEB)

    Mishkin, A.E.; Friedland, D.M.

    1990-02-01

    The Environmental Protection Agency has issued its first proposed New Source Performance Standards for municipal incinerators in 18 years. EPA's 1971 NSPS set only particulate limits. The new NSPS also sets combustion standards, acid gas and dioxin emission limits, and a materials separation requirement. The latest NSPS, plus proposed emission guidelines for existing facilities, both regulate municipal waste combustors (MWCs) under the Clean Air Act. They both contain new emission limitations for the various pollutants emitted by MWCs, and materials separation requirements. The emission limitations, and the control technologies on which they are based, are different for different size facilities. The proposed regulations also contain operating requirements, testing and record-keeping provisions, and requirements for operator certification and training. The New Source Performance Standards are summarized. The emission guidelines for existing facilities are then described. These include: best demonstrated technology, combustion controls, and materials separation.

  11. Abstraction and Consolidation of the Limit Procept by Means of Instrumented Schemes: The Complementary Role of Three Different Frameworks

    Science.gov (United States)

    Kidron, Ivy

    2008-01-01

    I investigate the contributions of three theoretical frameworks to a research process and the complementary role played by each. First, I describe the essence of each theory and then follow the analysis of their specific influence on the research process. The research process is on the conceptualization of the notion of limit by means of the…

  12. Trace analysis measurements in high-purity aluminium by means of radiochemical neutron and proton activation analysis

    International Nuclear Information System (INIS)

    Egger, K.P.

    1987-01-01

    The aim of the study consisted in the development of efficient radiochemical composite processes and activation methods for the multi-element determination of traces within the lower ng range in high-purity aluminium. More than 50 elements were determined with the help of activation with reactor neutrons; the selective separation of matrix activity (adsorption with hydrated antimony pentoxide) led to a noticeable improvement of detectability, as compared with instrumental neutron activation analysis. Further improvements were achieved with the help of radiochemical group separations in ion exchangers or with the help of the selective separation of the pure beta-emitting elements. Over 20 elements up to high atomic numbers were determined by means of activating 13 MeV protons and 23 Me protons. In this connection, improvements of the detection limit by as a factor of 10 were achieved with radiochemical separation techniques, as compared with pure instrumental proton activation analysis. (RB) [de

  13. Relativistic and separable classical hamiltonian particle dynamics

    International Nuclear Information System (INIS)

    Sazdjian, H.

    1981-01-01

    We show within the Hamiltonian formalism the existence of classical relativistic mechanics of N scalar particles interacting at a distance which satisfies the requirements of Poincare invariance, separability, world-line invariance and Einstein causality. The line of approach which is adopted here uses the methods of the theory of systems with constraints applied to manifestly covariant systems of particles. The study is limited to the case of scalar interactions remaining weak in the whole phase space and vanishing at large space-like separation distances of the particles. Poincare invariance requires the inclusion of many-body, up to N-body, potentials. Separability requires the use of individual or two-body variables and the construction of the total interaction from basic two-body interactions. Position variables of the particles are constructed in terms of the canonical variables of the theory according to the world-line invariance condition and the subsidiary conditions of the non-relativistic limit and separability. Positivity constraints on the interaction masses squared of the particles ensure that the velocities of the latter remain always smaller than the velocity of light

  14. Gross separation approaching a blunt trailing edge as the turbulence intensity increases.

    Science.gov (United States)

    Scheichl, B

    2014-07-28

    A novel rational description of incompressible two-dimensional time-mean turbulent boundary layer (BL) flow separating from a bluff body at an arbitrarily large globally formed Reynolds number, Re, is devised. Partly in contrast to and partly complementing previous approaches, it predicts a pronounced delay of massive separation as the turbulence intensity level increases. This is bounded from above by a weakly decaying Re-dependent gauge function (hence, the BL approximation stays intact locally), and thus the finite intensity level characterizing fully developed turbulence. However, it by far exceeds the moderate level found in a preceding study which copes with the associated moderate delay of separation. Thus, the present analysis bridges this self-consistent and another forerunner theory, proposing extremely retarded separation by anticipating a fully attached external potential flow. Specifically, it is shown upon formulation of a respective distinguished limit at which rate the separation point and the attached-flow trailing edge collapse as [Formula: see text] and how on a short streamwise scale the typical small velocity deficit in the core region of the incident BL evolves to a large one. Hence, at its base, the separating velocity profile varies generically with the one-third power of the wall distance, and the classical triple-deck problem describing local viscous-inviscid interaction crucial for moderately retarded separation is superseded by a Rayleigh problem, governing separation of that core layer. Its targeted solution proves vital for understanding the separation process more close to the wall. Most importantly, the analysis does not resort to any specific turbulence closure. A first comparison with the available experimentally found positions of separation for the canonical flow past a circular cylinder is encouraging. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  15. [Native, modified, and immobilized chymotrypsin in chaotropic media. Stabilization limits].

    Science.gov (United States)

    Panova, A A; Levitskiĭ, V Iu; Mozhaev, V V

    1994-07-01

    To stabilize alpha-chymotrypsin against irreversible thermal inactivation at high temperatures, methods of covalent modification and multi-point immobilization in combination with the addition of salting-in compounds were used. The upper limit of the protein stability proved to be the same for a combination of the modification and salting-in media and for each of these methods separately. The limit of stabilization reached by means of covalent immobilization is higher than the limit of stabilization reached by two other methods. The greatest stabilization of immobilized alpha-chymotrypsin by the salting-in media (a 10000 fold increase in the native enzyme's stability level) takes place only in the case of the protein with the minimum number of bonds with the support. Stabilization of the enzyme by these methods is explained in terms of the suppression of the conformational inactivation processes.

  16. Phase separation and soluble pollutant removal by means of alternationg current electrocoagulation

    International Nuclear Information System (INIS)

    Farrell, C.W.; Gardner-Clayson, T.W.

    1992-01-01

    Electro-Pure Systems (EPS) has undertaken a two-year laboratory program to investigate the technical and economic viability of alternation current electrocoagulation technology (ACE Technology) for Superfund site remediation. Alternating current electrocoagulation was originally developed as a treatment technology in the early 1980s to break stable aqueous suspensions of clays and coal fines in the mining industry. The technology offers a replacement for primary chemical coagulant addition to simplify effluent treatment, realize cost savings, and facilitate recovery of fine grained products that would otherwise have been lost. The traditional approach for treatment of such effluents entails addition of organic polymers or inorganic salts to promote flocculation of fine particulates and colloidi-sized oil droplets in aqueous suspensions. These flocculated materials are than separated by sedimentation or filtration. Unfortunately, chemical coagulant addition generates voluminous, gelatinous sludges which are difficult to dewater and slow to filter. As an alternative to chemical conditioning, alternation current electrocoagulation introduces into an aqueous medium highly, charged polymetric aluminum hydroxide species which will neutralize the electrostatic charges on suspended solids and oil droplets to facilitate their agglomeration (or coagulation). These species will also coprecipitate many soluble ions. ACE Technology prompts coagulation without adding any soluble species and produces a sludge with a lower contained water content and which will filter more rapidly through separation of the hazardous components from an aqueous waste the volume of potentially toxic pollutants requiring special handling and disposal can be minimized. Waste reduction goals may be accomplished by integrating this technology into a variety of operations which generate contaminated water

  17. Management of Vortices Trailing Flapped Wings via Separation Control

    Science.gov (United States)

    Greenblatt, David

    2005-01-01

    A pilot study was conducted on a flapped semi-span model to investigate the concept and viability of near-wake vortex management via separation control. Passive control was achieved by means of a simple fairing and active control was achieved via zero mass-flux blowing slots. Vortex sheet strength, estimated by integrating surface pressure ports, was used to predict vortex characteristics by means of inviscid rollup relations. Furthermore, vortices trailing the flaps were mapped using a seven-hole probe. Separation control was found to have a marked effect on vortex location, strength, tangential velocity, axial velocity and size over a wide range of angles of attack and control conditions. In general, the vortex trends were well predicted by the inviscid rollup relations. Manipulation of the separated flow near the flap edges exerted significant control over both outboard and inboard edge vortices while producing negligible lift excursions. Dynamic separation and attachment control was found to be an effective means for dynamically perturbing the vortex from arbitrarily long wavelengths down to wavelengths less than a typical wingspan. In summary, separation control has the potential for application to time-independent or time-dependent wake alleviation schemes, where the latter can be deployed to minimize adverse effects on ride-quality and dynamic structural loading.

  18. Stochastic mean-field dynamics for fermions in the weak coupling limit

    International Nuclear Information System (INIS)

    Lacroix, D.

    2005-09-01

    Assuming that the effect of the residual interaction beyond mean-field is weak and can be treated as a statistical ensemble of two-body interactions, a Markovian quantum jump theory is developed for fermionic systems. In this theory, jumps occur between many-body densities formed of pairs of states D |Φ a > b | / b | |Φ a > where |Φ a > and |Φ b > are anti-symmetrized products of single-particle states. The underlying Stochastic Mean-Field (SMF) theory is discussed and applied to the monopole vibration of a spherical 40 Ca nucleus under the influence of a statistical ensemble of two-body contact interactions. In this example, the mean-field evolution of one-body observables is recovered by averaging over different stochastic trajectories while fluctuations beyond mean-field are observed. Finally, the nature of the fluctuations is discussed. (author)

  19. Children's separation anxiety scale (CSAS: psychometric properties.

    Directory of Open Access Journals (Sweden)

    Xavier Méndez

    Full Text Available This study describes the psychometric properties of the Children's Separation Anxiety Scale (CSAS, which assesses separation anxiety symptoms in childhood. Participants in Study 1 were 1,908 schoolchildren aged between 8 and 11. Exploratory factor analysis identified four factors: worry about separation, distress from separation, opposition to separation, and calm at separation, which explained 46.91% of the variance. In Study 2, 6,016 children aged 8-11 participated. The factor model in Study 1 was validated by confirmatory factor analysis. The internal consistency (α = 0.82 and temporal stability (r = 0.83 of the instrument were good. The convergent and discriminant validity were evaluated by means of correlations with other measures of separation anxiety, childhood anxiety, depression and anger. Sensitivity of the scale was 85% and its specificity, 95%. The results support the reliability and validity of the CSAS.

  20. Stochastic mean-field dynamics for fermions in the weak coupling limit

    Energy Technology Data Exchange (ETDEWEB)

    Lacroix, D

    2005-09-15

    Assuming that the effect of the residual interaction beyond mean-field is weak and can be treated as a statistical ensemble of two-body interactions, a Markovian quantum jump theory is developed for fermionic systems. In this theory, jumps occur between many-body densities formed of pairs of states D |{phi}{sub a}> <|{phi}{sub b}| / <|{phi}{sub b} | |{phi} {sub a}> where |{phi}{sub a}> and |{phi}{sub b}> are anti-symmetrized products of single-particle states. The underlying Stochastic Mean-Field (SMF) theory is discussed and applied to the monopole vibration of a spherical {sup 40}Ca nucleus under the influence of a statistical ensemble of two-body contact interactions. In this example, the mean-field evolution of one-body observables is recovered by averaging over different stochastic trajectories while fluctuations beyond mean-field are observed. Finally, the nature of the fluctuations is discussed. (author)

  1. Method and device for the separation of particles

    NARCIS (Netherlands)

    Rem, P.C.; Van Kooy, L.A.

    2004-01-01

    The invention relates to a method of in a liquid separating a mixture of particles that within chosen limits have different physical property values, wherein the particles to be separated are supplied via a feeder to a screen upon which a layer of facilitating particles is disposed, the size of the

  2. Limitation of Piston Centre Shift in Free Piston Stirling Engines

    Energy Technology Data Exchange (ETDEWEB)

    Van der Woude, R.R. [ECN Energy in the Built Environment and Networks, Petten (Netherlands)

    2006-09-15

    Piston centre shift is one of the phenomena setting Free Piston engines apart from traditional kinematic engines. In kinematic engines the piston centre position is determined by the design of the engine's internal mechanisms. In Free Piston engines however, the piston's mid-stroke position is determined by the balance of forces acting on the piston, in particular flexure and gas pressure forces. As a result, a mean pressure difference across the piston emerging during engine operation will cause the piston mid-stroke position to shift away from the geometrical centre. This process will continue until a new balance is reached with the flexure forces counteracting the new mean pressure balance. Yet, before the new equilibrium is reached, the resulting piston centre shift may have grown to such an extent that piston overstrokes have become inevitable. In order to limit piston centre shift and prevent piston overstrokes, several solutions have been proposed in the past. Popular solutions include ingenious mechanisms to vent gas between the spaces separated by the piston, in an attempt to limit the pressure difference. Enatec however has adopted a different approach by applying a precisely determined clearance between the piston and cylinder. With the right shape the clearance effectively limits the mean pressure difference across the piston and therefore limits the extent of the piston centre drift. Taking benefit of tightly controlled tolerances of both piston and cylinder, Enatec has demonstrated the effectiveness of this simple concept in series produced engines.

  3. Return-to-activity after anatomical reconstruction of acute high-grade acromioclavicular separation.

    Science.gov (United States)

    Saier, T; Plath, J E; Beitzel, K; Minzlaff, P; Feucht, J M; Reuter, S; Martetschläger, F; Imhoff, Andreas B; Aboalata, M; Braun, S

    2016-04-02

    To evaluate return-to-activity (RtA) after anatomical reconstruction of acute high-grade acromioclavicular joint (ACJ) separation. A total of 42 patients with anatomical reconstruction of acute high-grade ACJ-separation (Rockwood Type V) were surveyed to determine RtA at a mean 31 months follow-up (f-u). Sports disciplines, intensity, level of competition, participation in overhead and/or contact sports, as well as activity scales (DASH-Sport-Module, Tegner Activity Scale) were evaluated. Functional outcome evaluation included Constant score and QuickDASH. All patients (42/42) participated in sporting activities at f-u. Neither participation in overhead/contact sports, nor level of activity declined significantly (n.s.). 62 % (n = 26) of patients reported subjective sports specific ACJ integrity to be at least the same as prior to the trauma. Sporting intensity (hours/week: 7.3 h to 5.4 h, p = .004) and level of competition (p = .02) were reduced. If activity changed, in 50 % other reasons but clinical symptoms/impairment were named for modified behavior. QuickDASH (mean 6, range 0-54, SD 11) and DASH-Sport-Module (mean 6, range 0-56, SD 13) revealed only minor disabilities at f-u. Over time Constant score improved significant to an excellent score (mean 94, range 86-100, SD 4; p < .001). Functional outcome was not correlated with RtA (n.s.). All patients participated in sporting activities after anatomical reconstruction of high-grade (Rockwood Type V) ACJ-separation. With a high functional outcome there was no significant change in activity level (Tegner) and participation in overhead and/or contact sports observed. There was no correlation between functional outcome and RtA. Limiting, there were alterations in time spent for sporting activities and level of competition observed. But in 50 % those were not related to ACJ symptoms/impairment. Unrelated to successful re-established integrity and function of the ACJ it should be considered that

  4. Isotope separation by laser deflection of an atomic beam

    International Nuclear Information System (INIS)

    Bernhardt, A.F.

    1975-02-01

    Separation of isotopes of barium was accomplished by laser deflection of a single isotopic component of an atomic beam. With a tunable narrow linewidth dye laser, small differences in absorption frequency of different barium isotopes on the 6s 2 1 S 0 --6s6p 1 P 1 5536A resonance were exploited to deflect atoms of a single isotopic component of an atomic beam through an angle large enough to physically separate them from the atomic beam. It is shown that the principal limitation on separation efficiency, the fraction of the desired isotopic component which can be separated, is determined by the branching ratio from the excited state into metastable states. The isotopic purity of the separated atoms was measured to be in excess of 0.9, limited only by instrumental uncertainty. To improve the efficiency of separation, a second dye laser was employed to excite atoms which had decayed to the 6s5d metastable state into the 6p5d 1 P 1 state from which they could decay to the ground state and continue to be deflected on the 5535A transition. With the addition of the second laser, separation efficiency of greater than 83 percent was achieved, limited by metastable state accumulation in the 5d 2 1 D 2 state which is accessible from the 6p5d 1 P 1 level. It was found that the decay rate from the 6p5d state into the 5d 2 metastable state was fully 2/3 the decay rate to the ground state, corresponding to an oscillator strength of 0.58. (U.S.)

  5. Entropy production and nonequilibrium stationarity in quantum dynamical systems. Physical meaning of van Hove limit

    International Nuclear Information System (INIS)

    Ojima, Izumi

    1989-01-01

    With aid of the so-called dilation method, a concise formula is obtained for the entropy production in the algebraic formulation of quantum dynamical systems. In this framework, the initial ergodic state of an external force system plays a pivotal role in generating dissipativity as a conditional expectation. The physical meaning of van Hove limit is clarified through the scale-changing transformation to control transitions between microscopic and macroscopic levels. It plays a crucial role in realizing the macroscopic stationary in the presence of microscopic fluctuations as well as in the transition from non-Markovian (groupoid) dynamics to Markovian dissipative processes of state changes. The extension of the formalism to cases with spatial and internal inhomogeneity is indicated in the light of the groupoid dynamical systems and noncommutative integration theory

  6. Separation and determination of a trace amount of lithium as its thenoyltrifluoroacetone complex with 12-crown-4 by means of synergic extraction and flame photometry

    OpenAIRE

    Itoh, Tatsuo; Billah, Mokarram; Honjo, Takaharu; Terada, Kikuo

    1991-01-01

    A new method for the separation and determination of a trace amount of lithium in ppb∼ppm level in water as its thenoyltrifluoroacetone (TTA) complex with 12-crown-4 (12C4) has been established by means of synergic extraction and back extraction combined with flame photometry. The effect of various factors (pH, solvent, reagent concentration, shaking time, preconcentration factor, and foreign ions etc.) on the extraction and back extraction of lithium has been investigated. Here the lithium T...

  7. Mean field interaction in biochemical reaction networks

    KAUST Repository

    Tembine, Hamidou; Tempone, Raul; Vilanova, Pedro

    2011-01-01

    In this paper we establish a relationship between chemical dynamics and mean field game dynamics. We show that chemical reaction networks can be studied using noisy mean field limits. We provide deterministic, noisy and switching mean field limits

  8. Material review of Li ion battery separators

    Science.gov (United States)

    Weber, Christoph J.; Geiger, Sigrid; Falusi, Sandra; Roth, Michael

    2014-06-01

    Separators for Li Ion batteries have a strong impact on cell production, cell performance, life, as well as reliability and safety. The separator market volume is about 500 million m2 mainly based on consumer applications. It is expected to grow strongly over the next decade for mobile and stationary applications using large cells. At present, the market is essentially served by polyolefine membranes. Such membranes have some technological limitations, such as wettability, porosity, penetration resistance, shrinkage and meltdown. The development of a cell failure due to internal short circuit is potentially closely related to separator material properties. Consequently, advanced separators became an intense area of worldwide research and development activity in academia and industry. New separator technologies are being developed especially to address safety and reliability related property improvements.

  9. Material review of Li ion battery separators

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Christoph J., E-mail: Christoph.Weber@freudenberg-nw.com; Geiger, Sigrid, E-mail: Christoph.Weber@freudenberg-nw.com [Freudenberg Vliesstoffe SE and Co KG, 69465 Weinheim (Germany); Falusi, Sandra; Roth, Michael [Freudenberg Forschungsdienste SE and Co KG, 69465 Weinheim (Germany)

    2014-06-16

    Separators for Li Ion batteries have a strong impact on cell production, cell performance, life, as well as reliability and safety. The separator market volume is about 500 million m{sup 2} mainly based on consumer applications. It is expected to grow strongly over the next decade for mobile and stationary applications using large cells. At present, the market is essentially served by polyolefine membranes. Such membranes have some technological limitations, such as wettability, porosity, penetration resistance, shrinkage and meltdown. The development of a cell failure due to internal short circuit is potentially closely related to separator material properties. Consequently, advanced separators became an intense area of worldwide research and development activity in academia and industry. New separator technologies are being developed especially to address safety and reliability related property improvements.

  10. Local Contrast Enhancement Utilizing Bidirectional Switching Equalization of Separated and Clipped Subhistograms

    Directory of Open Access Journals (Sweden)

    Haidi Ibrahim

    2014-01-01

    Full Text Available Digital image contrast enhancement methods that are based on histogram equalization technique are still useful for the use in consumer electronic products due to their simple implementation. However, almost all the suggested enhancement methods are using global processing technique, which does not emphasize local contents. Therefore, this paper proposes a new local image contrast enhancement method, based on histogram equalization technique, which not only enhances the contrast, but also increases the sharpness of the image. Besides, this method is also able to preserve the mean brightness of the image. In order to limit the noise amplification, this newly proposed method utilizes local mean-separation, and clipped histogram bins methodologies. Based on nine test color images and the benchmark with other three histogram equalization based methods, the proposed technique shows the best overall performance.

  11. Microporous polyethylene separators — today and tomorrow. Separator development trends for modern automotive batteries

    Science.gov (United States)

    Böhnstedt, Werner

    During the past decade, the design of modern automotive batteries has undergone a fundamental change. The introduction of microporous polyethylene pocket separators has resulted in an approximately 8% better volume utilization. Besides increasing the energy density, the polyethylene envelope has enalbed an improvement in cold-cranking performance and has raised the production efficiency. A first failure-mode analysis of pocket-separated automotive batteries in Europe with respect to leaf separation is presented. For comparable service life, a shift in failure mode has been found. Although corrosion of the positive electrode still dominates, a significant increase in positive active-material shedding is noted. This is certainly a consequence of the general trend towards lower antimony contents. Shorting through the separator is only found in cases of severe battery mistreatment. This positive, intermediary result is supplemented by an outlook on emerging development trends. Future automotive batteries will experience elevated operating temperatures, higher cycling loads, and maintenance freedom. Battery tests at temperatures up to 75 °C with various alloy combinations show that the hybrid design is best suited to meet the expected requirements. Microporous polyethylene pocket separation is not expected to be a limiting factor; the trend to lower antimony alloy content and increased cycling load will demonstrate the advantage of this separation even more clearly than in the past. Optimization of the already achieved, balanced separator characteristics profile with the reference parameters of electrical performance, water loss, durability and machinability will stimulate further development work.

  12. Laser isotope separation studies in JAERI

    International Nuclear Information System (INIS)

    Arisawa, Takashi; Shiba, Koreyuki

    1986-01-01

    For uranium enrichment, Japan Atomic Energy Research Institute (JAERI) has been studying atomic vapor laser isotope separation since 1976, in addition to such separation methods as gas diffusion, chemical exchange and gas-dynamic techniques. Studies carried out to date in JAERI is briefly summarized in the first part of the report. Then, some major separation techniques which have been studied in JAERI are outlined, and typical results obtained are presented. A large part is devoted to the multiple-photon photoionization technique, which is commonly known as the atomic laser isotope separation method for uranium enrichment. It has such advantages as 1) very high spectral selectivity for the relevant isotope and 2) highly improved photoionizing effect by means of two- and three-step resonance photoionization processes. Here, the atomic laser isotope separation method is discussed in detail with respect to the evaporation process, energy levels, photoionization, selectivity, photoionization schemes, ion recovery, separation in macroscopic amounts, and separation of trace amounts of isotopes. Typical observed and claculated results related to these subjects are shown. In addition, the report briefly describes some other separation processes including laser induced chemical reaction, multiple photo-dissociation, multiple-photo excitation and UV dissociation, laser induced thermal diffusion, and laser centrifugation. (Nogami, K.)

  13. Limiter and first wall of the fusion reactor blanket

    International Nuclear Information System (INIS)

    Danilov, I.; Skladnov, K.; Kolganov, V.

    1994-01-01

    Previous designing of the first wall and limiter has allowed to determine their possible embodiment depending on the parameters and operation conditions of the blanket. As a rule limiter is a separate structure located on the plasma facing surface of the blanket assembly. Possible versions of the limiter/FW which may be considered: (1) limiters with mechanical attachment of the protective part; (2) limiters with the attachment with brazing; (3) limiters with common/separate cooling system; (4) limiter as a substitute of the FW. Generally the FW/limiter structure includes protective shield and its cooling system which consist of protective coating, heat accumulator, conductive layer and attachment locks

  14. The Theory of Separation of Powers in Nigeria: An Assessment

    African Journals Online (AJOL)

    gold

    2012-07-26

    Jul 26, 2012 ... The Theory of Separation of Powers means that, a different body of persons .... legislature enacting oppressive laws which the executive will .... Nigeria, separation of powers is a fundamental constitutional principle which.

  15. Impact, meaning and need for help and support: The experience of parents caring for children with disabilities, life-limiting/life-threatening illness or technology dependence.

    Science.gov (United States)

    Whiting, Mark

    2013-03-01

    Parenting a child with complex needs or disabilities is a challenging proposition. This study, which drew upon of the experiences of the parents of 34 children (in 33 families), set out to explore the themes of impact, need for help and support and meaning/sense-making as they were related by parents. Data were collected using semi-structured interviews, and an emerging theoretical framework was validated through the use of a series of mind-maps(®) which were presented to individual parents as the basis for a second round (verificational) interview. Parents were nominated into the study by health care professions who were asked to identify the subject children to one of three separate sub-groups: children with a disability; children with a life-limiting/life-threatening illness or children with a technology dependence. Comparisons were made between the three study sub-groups in order to identify areas of consistency and of inconsistency. A fourth study theme - 'battleground' emerged from entirely within the data set. Sense-making occupied a central position within the overall theoretical framework for the study and parental perception of 'battleground' presented as significant element of parental sense-making, particularly in the context of their relationships with professional staff. © The Author(s) 2012.

  16. Separation process for boron isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Rockwood, S D

    1975-06-12

    The method according to the invention is characterized by the steps of preparing a gaseous mixture of BCl/sub 3/ containing the isotopes of boron and oxygen as the extractor, irradiating that mixture in the tube of the separator device by means of P- or R-lines of a CO/sub 2/ laser for exciting the molecules containing a given isotope of boron, simultaneously irradiating the mixture with UV for photodissociating the excited BCl/sub 3/ molecules and separating BCl/sub 3/ from the reaction products of photodissociation and from oxygen. Such method is suitable for preparing boron used in nuclear reactors.

  17. Technical clarification to Silbert and Thomas (2013): "decisional separability, model identification, and statistical inference in the general recognition theory framework".

    Science.gov (United States)

    Thomas, Robin D; Silbert, Noah H

    2014-04-01

    We offer a minor technical correction to the published proof of part (ii) of the main theorem in Silbert and Thomas (Psychonomic Bulletin & Review, 20, 1-20, 2013) that somewhat limits the scope of the equivalence observed in that work. Specifically, in order for a mean shift integrality with decisional separability to be mimicked by a perceptually separable but nondecisionally separable configuration, one needs to assume stimulus invariance. This holds when all of the covariance matrices in the stimulus configuration are equal to each other. We note that part (i) of the theorem is unaffected by this modification; an empirical finding of perceptual separability and the failure of decisional separability can be mimicked by a perceptually nonseparable, decisionally separable configuration without restricting the covariance matrices to be equal. We also note that stimulus invariance is often assumed in simple designs (e.g., Macmillan & Ornstein in Journal of the Acoustical Society of America, 97, 1261-1285, 1998), due to the implausibility of different perceptual correlations being present within stimuli perched very closely in perceptual space.

  18. The separation of hydrocarbons from waste vapor streams

    International Nuclear Information System (INIS)

    Behling, R.D.; Ohlrogge, K.; Peinemann, K.V.; Kyburz, E.

    1989-01-01

    Hydrocarbon vapors generated from industrial processes dispersed into air are contributing factors for the creation of photochemical smog. The separation of hydrocarbon vapor by means of membranes is in case of some applications a technically simple and economic process. A membrane vapor separation process with a following treatment of the retentate by catalytic incineration is introduced in this paper

  19. Application of microcomputer to X-ray radiometric ore separation

    International Nuclear Information System (INIS)

    Neverov, A.D.; Aleksandrov, P.S.; Kotler, N.I.

    1988-01-01

    The practical use of microcomputers as universal means for converting information for solving applied problems of X-ray radiometric ore separation method is considered. Laboratory tests of two metals - tungsten and tin manifested high efficiency of the developed system. X-ray radiometric separator software is developed

  20. S.E.T., CSNI Separate Effects Test Facility Validation Matrix

    International Nuclear Information System (INIS)

    1997-01-01

    1 - Description of test facility: The SET matrix of experiments is suitable for the developmental assessment of thermal-hydraulics transient system computer codes by selecting individual tests from selected facilities, relevant to each phenomena. Test facilities differ from one another in geometrical dimensions, geometrical configuration and operating capabilities or conditions. Correlation between SET facility and phenomena were calculated on the basis of suitability for model validation (which means that a facility is designed in such a way as to stimulate the phenomena assumed to occur in a plant and is sufficiently instrumented); limited suitability for model variation (which means that a facility is designed in such a way as to stimulate the phenomena assumed to occur in a plant but has problems associated with imperfect scaling, different test fluids or insufficient instrumentation); and unsuitability for model validation. 2 - Description of test: Whereas integral experiments are usually designed to follow the behaviour of a reactor system in various off-normal or accident transients, separate effects tests focus on the behaviour of a single component, or on the characteristics of one thermal-hydraulic phenomenon. The construction of a separate effects test matrix is an attempt to collect together the best sets of openly available test data for code validation, assessment and improvement, from the wide range of experiments that have been carried out world-wide in the field of thermal hydraulics. In all, 2094 tests are included in the SET matrix

  1. Separation of soft and collinear infrared limits of QCD squared matrix elements

    CERN Document Server

    Nagy, Zoltan; Trócsányi, Z L; Trocsanyi, Zoltan; Somogyi, Gabor; Trocsanyi, Zoltan

    2007-01-01

    We present a simple way of separating the overlap between the soft and collinear factorization formulae of QCD squared matrix elements. We check its validity explicitly for single and double unresolved emissions of tree-level processes. The new method makes possible the definition of helicity-dependent subtraction terms for regularizing the real contributions in computing radiative corrections to QCD jet cross sections. This implies application of Monte Carlo helicity summation in computing higher order corrections.

  2. Mean free paths, viscosity, and the limitations of perfect fluid hydrodynamics in the description of the quark-gluon plasma

    International Nuclear Information System (INIS)

    McLerran, L.

    1985-01-01

    The author discusses the applicability of a hydrodynamic description of high energy hadronic collisions. The author reviews the results of recent computations of the mean free paths of quarks and gluons in a quark-gluon plasma, and the corresponding results for viscous coefficients. These quantities are employed to evaluate the limits to the application of perfect fluid hydrodynamics as a description of the time evolution of matter produced in various hardronic collisions

  3. Microparticle Separation by Cyclonic Separation

    Science.gov (United States)

    Karback, Keegan; Leith, Alexander

    2017-11-01

    The ability to separate particles based on their size has wide ranging applications from the industrial to the medical. Currently, cyclonic separators are primarily used in agriculture and manufacturing to syphon out contaminates or products from an air supply. This has led us to believe that cyclonic separation has more applications than the agricultural and industrial. Using the OpenFoam computational package, we were able to determine the flow parameters of a vortex in a cyclonic separator in order to segregate dust particles to a cutoff size of tens of nanometers. To test the model, we constructed an experiment to separate a test dust of various sized particles. We filled a chamber with Arizona test dust and utilized an acoustic suspension technique to segregate particles finer than a coarse cutoff size and introduce them into the cyclonic separation apparatus where they were further separated via a vortex following our computational model. The size of the particles separated from this experiment will be used to further refine our model. Metropolitan State University of Denver, Colorado University of Denver, Dr. Randall Tagg, Dr. Richard Krantz.

  4. Mean field interaction in biochemical reaction networks

    KAUST Repository

    Tembine, Hamidou

    2011-09-01

    In this paper we establish a relationship between chemical dynamics and mean field game dynamics. We show that chemical reaction networks can be studied using noisy mean field limits. We provide deterministic, noisy and switching mean field limits and illustrate them with numerical examples. © 2011 IEEE.

  5. Development of a water separator for steam drying in nuclear power plants

    International Nuclear Information System (INIS)

    Kall, H.

    1979-01-01

    In the wet steam of nuclear power plants with light water cooling the content of liquid phase before entering the high- and low-pressure turbine or at the inlet of the reheater connected in between is limited to a few parts per thousand. For the mechanical drying necessary to maintain this moisture limit there is suited the socalled lamellar separator, in which the vertical laminae, arranged one beside the other, confine a great number of separating ducts, bended in periodically changing sequence, through which wet steam is flowing. In the development of such a lamellar separator with internal drain channels described in this paper the droplet motion in the carrier gas stream and the discharge of the separated liquid is treated independently from each other. The mathematical and experimental study of the first-mentioned partial process leads to its complete description in a dimensionless separation diagram. During the subsequent discharge of the primarily separated droplet fluid there may be torn off droplets by the steam flow and carried away from the separator.The limit for the draining capacity reached with the occurrence of this phenomenon was determined in preliminary experiments with air and water and in experiments with wet steam carried out close to operating conditions. (orig.) 891 GL/orig. 892 RRD [de

  6. Continuous Time Finite State Mean Field Games

    International Nuclear Information System (INIS)

    Gomes, Diogo A.; Mohr, Joana; Souza, Rafael Rigão

    2013-01-01

    In this paper we consider symmetric games where a large number of players can be in any one of d states. We derive a limiting mean field model and characterize its main properties. This mean field limit is a system of coupled ordinary differential equations with initial-terminal data. For this mean field problem we prove a trend to equilibrium theorem, that is convergence, in an appropriate limit, to stationary solutions. Then we study an N+1-player problem, which the mean field model attempts to approximate. Our main result is the convergence as N→∞ of the mean field model and an estimate of the rate of convergence. We end the paper with some further examples for potential mean field games

  7. Continuous Time Finite State Mean Field Games

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Diogo A., E-mail: dgomes@math.ist.utl.pt [Instituto Superior Tecnico, Center for Mathematical Analysis, Geometry, and Dynamical Systems, Departamento de Matematica (Portugal); Mohr, Joana, E-mail: joana.mohr@ufrgs.br; Souza, Rafael Rigao, E-mail: rafars@mat.ufrgs.br [UFRGS, Instituto de Matematica (Brazil)

    2013-08-01

    In this paper we consider symmetric games where a large number of players can be in any one of d states. We derive a limiting mean field model and characterize its main properties. This mean field limit is a system of coupled ordinary differential equations with initial-terminal data. For this mean field problem we prove a trend to equilibrium theorem, that is convergence, in an appropriate limit, to stationary solutions. Then we study an N+1-player problem, which the mean field model attempts to approximate. Our main result is the convergence as N{yields}{infinity} of the mean field model and an estimate of the rate of convergence. We end the paper with some further examples for potential mean field games.

  8. Geometric mean for subspace selection.

    Science.gov (United States)

    Tao, Dacheng; Li, Xuelong; Wu, Xindong; Maybank, Stephen J

    2009-02-01

    Subspace selection approaches are powerful tools in pattern classification and data visualization. One of the most important subspace approaches is the linear dimensionality reduction step in the Fisher's linear discriminant analysis (FLDA), which has been successfully employed in many fields such as biometrics, bioinformatics, and multimedia information management. However, the linear dimensionality reduction step in FLDA has a critical drawback: for a classification task with c classes, if the dimension of the projected subspace is strictly lower than c - 1, the projection to a subspace tends to merge those classes, which are close together in the original feature space. If separate classes are sampled from Gaussian distributions, all with identical covariance matrices, then the linear dimensionality reduction step in FLDA maximizes the mean value of the Kullback-Leibler (KL) divergences between different classes. Based on this viewpoint, the geometric mean for subspace selection is studied in this paper. Three criteria are analyzed: 1) maximization of the geometric mean of the KL divergences, 2) maximization of the geometric mean of the normalized KL divergences, and 3) the combination of 1 and 2. Preliminary experimental results based on synthetic data, UCI Machine Learning Repository, and handwriting digits show that the third criterion is a potential discriminative subspace selection method, which significantly reduces the class separation problem in comparing with the linear dimensionality reduction step in FLDA and its several representative extensions.

  9. X-ray radiometric separation of low-grade tin ores

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

    1984-10-01

    The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. /sup 241/Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained.

  10. X-ray radiometric separation of low-grade tin ores

    International Nuclear Information System (INIS)

    Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

    1984-01-01

    The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. 241 Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained

  11. Experimental study of multi-component separation by gas centrifuge

    International Nuclear Information System (INIS)

    Zhou, M.S.; Liang, X.W.; Chen, W.N.; Yin, Y.T.

    2006-01-01

    Stable isotopes are applied in many areas and most stable isotopes are multi-component, This paper presents experimental results of several stable isotopes separation conducted in Tsinghua University by using ultra-speed gas centrifuges. Xe, WF 6 , TeF 6 , SiHCl 3 , SiF 4 were chosen as the process gases. By adjusting some of the centrifuge's parameters, the suitable centrifuge parameters for different process gas separations were found and the overall unit separation factors γ 0 were obtained by means of single gas centrifuge separation. The experimental results show that with appropriate process gases, stable isotope separation by gas centrifuge was effective. (authors)

  12. Glycerol extracting dealcoholization for the biodiesel separation process.

    Science.gov (United States)

    Ye, Jianchu; Sha, Yong; Zhang, Yun; Yuan, Yunlong; Wu, Housheng

    2011-04-01

    By means of utilizing sunflower oil and Jatropha oil as raw oil respectively, the biodiesel transesterification production and the multi-stage extracting separation were carried out experimentally. Results indicate that dealcoholized crude glycerol can be utilized as the extracting agent to achieve effective separation of methanol from the methyl ester phase, and the glycerol content in the dealcoholized methyl esters is as low as 0.02 wt.%. For the biodiesel separation process utilizing glycerol extracting dealcoholization, its technical and equipment information were acquired through the rigorous process simulation in contrast to the traditional biodiesel distillation separation process, and results show that its energy consumption decrease about 35% in contrast to that of the distillation separation process. The glycerol extracting dealcoholization has sufficient feasibility and superiority for the biodiesel separation process. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Continuous time finite state mean field games

    KAUST Repository

    Gomes, Diogo A.; Mohr, Joana; Souza, Rafael Rigã o

    2013-01-01

    In this paper we consider symmetric games where a large number of players can be in any one of d states. We derive a limiting mean field model and characterize its main properties. This mean field limit is a system of coupled ordinary differential equations with initial-terminal data. For this mean field problem we prove a trend to equilibrium theorem, that is convergence, in an appropriate limit, to stationary solutions. Then we study an N+1-player problem, which the mean field model attempts to approximate. Our main result is the convergence as N→∞ of the mean field model and an estimate of the rate of convergence. We end the paper with some further examples for potential mean field games. © 2013 Springer Science+Business Media New York.

  14. Continuous time finite state mean field games

    KAUST Repository

    Gomes, Diogo A.

    2013-04-23

    In this paper we consider symmetric games where a large number of players can be in any one of d states. We derive a limiting mean field model and characterize its main properties. This mean field limit is a system of coupled ordinary differential equations with initial-terminal data. For this mean field problem we prove a trend to equilibrium theorem, that is convergence, in an appropriate limit, to stationary solutions. Then we study an N+1-player problem, which the mean field model attempts to approximate. Our main result is the convergence as N→∞ of the mean field model and an estimate of the rate of convergence. We end the paper with some further examples for potential mean field games. © 2013 Springer Science+Business Media New York.

  15. Beam-limiting and radiation-limiting interlocks

    International Nuclear Information System (INIS)

    Macek, R.J.

    1996-01-01

    This paper reviews several aspects of beam-limiting and radiation- limiting interlocks used for personnel protection at high-intensity accelerators. It is based heavily on the experience at the Los Alamos Neutron Science Center (LANSCE) where instrumentation-based protection is used extensively. Topics include the need for ''active'' protection systems, system requirements, design criteria, and means of achieving and assessing acceptable reliability. The experience with several specific devices (ion chamber-based beam loss interlock, beam current limiter interlock, and neutron radiation interlock) designed and/or deployed to these requirements and criteria is evaluated

  16. Review of the gas centrifuge until 1962. Part I: Principles of separation physics

    International Nuclear Information System (INIS)

    Whitley, S.

    1984-01-01

    There are two sets of principles involved in the development of the gas centrifuge, the internal separation physics and the external means of spinning a rotor at very high speeds. Only the first aspect is discussed in this part of the review. First, the industrial requirement for the separation of the uranium isotopes is defined so that the separation history can be put in a modern perspective. The history of separation physics itself is then traced back to the theory of centrifugal force by Huygens and the equivalence of this force to that of gravity. The barometric equation giving the variation of atmospheric pressure with height and the law of partial pressures can then be adapted to the centrifuge to give the steady-state theory of separation. This work was completed in the last century but was not confirmed in its application to isotope separation until 1936. The detailed separation physics for non-steady-state conditions required for a production centrifuge was developed during the American wartime Manhattan Project. During this work the theory giving the maximum output of a centrifuge was developed by Dirac, and soon afterwards Cohen and Kaplan showed that the best method of operation for a production centrifuge is in a countercurrent mode of operation. This method gives a large separation factor at relatively small flow rates through the rotor. The theory of how to set up an internal countercurrent was given by Martin during an equivalent wartime German project, and refinements to the theory, showing how the countercurrent persists along a centrifuge rotor, was given by Dirac and Steenbeck, the latter during a postwar Russian project. This theory was extended by Parker, Ging, and Mayo of the University of Virginia, whose work was completed by 1962, the limit of this review

  17. The modernization and improvement of the BNL short separators

    International Nuclear Information System (INIS)

    Kovarik, V.; Montemurro, P.; Sandberg, J.; Hulliger, R.

    1979-01-01

    Two high voltage separators (10 and 15 cm gaps) have been designed, constructed, and tested for use in the new LESB II experimental beam line. Both separators have been tested to 800 kV (limited by power supply capability). The 10 cm gap separator is of the conventional heated glass-cathode, steel-anode design. The 15 cm gap separator has a glass cathode and glass anode. This separator has been conditioned above 780 kV in hard vacuum (10 -6 torr range). In order to attain and reliably maintain the high voltages necessary for testing the separator, the power supplies, cable terminations, feedthroughs, high voltage bushings, standoffs, and surge resistors have all been modified. These modifications and the final test results are discussed in detail. (Auth.)

  18. Mars Atmospheric Capture and Gas Separation

    Science.gov (United States)

    Muscatello, Anthony; Santiago-Maldonado, Edgardo; Gibson, Tracy; Devor, Robert; Captain, James

    2011-01-01

    The Mars atmospheric capture and gas separation project is selecting, developing, and demonstrating techniques to capture and purify Martian atmospheric gases for their utilization for the production of hydrocarbons, oxygen, and water in ISRU systems. Trace gases will be required to be separated from Martian atmospheric gases to provide pure C02 to processing elements. In addition, other Martian gases, such as nitrogen and argon, occur in concentrations high enough to be useful as buffer gas and should be captured as welL To achieve these goals, highly efficient gas separation processes will be required. These gas separation techniques are also required across various areas within the ISRU project to support various consumable production processes. The development of innovative gas separation techniques will evaluate the current state-of-the-art for the gas separation required, with the objective to demonstrate and develop light-weight, low-power methods for gas separation. Gas separation requirements include, but are not limited to the selective separation of: (1) methane and water from un-reacted carbon oxides (C02- CO) and hydrogen typical of a Sabatier-type process, (2) carbon oxides and water from unreacted hydrogen from a Reverse Water-Gas Shift process, (3) carbon oxides from oxygen from a trash/waste processing reaction, and (4) helium from hydrogen or oxygen from a propellant scavenging process. Potential technologies for the separations include freezers, selective membranes, selective solvents, polymeric sorbents, zeolites, and new technologies. This paper and presentation will summarize the results of an extensive literature review and laboratory evaluations of candidate technologies for the capture and separation of C02 and other relevant gases.

  19. Four-way rf beam separator

    International Nuclear Information System (INIS)

    Neil, V.K.

    1982-01-01

    A method for separating a continuous beam of relativistic particles into four pulsed beams is investigated theoretically. The separation is periodic with period 2π/#betta# so that each of the four beams consists of current pulses of duration π/#betta#. The separation is accomplished by a series of rf cavities in the beam line. The cavities operate in the TM 110 and have frequencies, #betta#, 3#betta#, 5#betta#, 7#betta#, etc. The transverse momentum imparted to the beam particles results in a time-dependent displacement of the beam centroid at a position downstream of the cavity array. The mathematical limitations imposed by truncating a Fourier series are discussed, and an expression derived for the necessary phase and amplitude of each cavity. The rf induced by the beam in the cavities is treated in detail, and does not appear to be a serious problem

  20. Isotope separation method and apparatus

    International Nuclear Information System (INIS)

    Lyon, R.K.; Eisner, P.N.; Thomas, W.R.L.

    1980-01-01

    A method and apparatus are specified for separating a mixture of isotopes present in a compound, preferably a gaseous compound, into two or more parts in each of which the abundances of the isotopes differ from the natural abundances of the isotopes in the compound. The invention particularly relates to carrying out a laser induced, isotopically selective conversion of gaseous molecules in such a manner as to achieve more than one stage of isotope separation along the length of the laser beam. As an example, the invention is applied to the separation of the isotopes of uranium in UF 6 , in which either the U-235 or U-238 isotope is selectively excited by means of irradiation from an infrared laser, and the selectively excited isotope converted into a product that can be recovered from UF 6 by one of a variety of methods that are described. (U.K.)

  1. Chromatographic separation of europium and gadolinum mixtures by ethylenediaminedisuccinic acid

    International Nuclear Information System (INIS)

    Kolleganov, M.Yu.; Nazarov, P.P.; Martynenko, L.I.; Mtrofanova, N.D.; Spitsyn, V.I.

    1985-01-01

    Comparative investigation of chromatographic separation of impurities of Eu and Gd micro- and macroquantities by means of ethylenediaminedisuccinic (EDDS) and ethylene-diaminetetraacetic (EDTA) acids is performed. It is shown that EDTA is a sufficiently effective agent for separation of this pair of elements. The values of EU and Gd separation coefficients obtained in experiments with RE microquantities are not realized at Eu-Gd, macroquantities separation which probably is connected with the influence of polymerization processes in the systems containing RE and EDDS complexes

  2. Sulfur and selenium isotope separation by distillation

    International Nuclear Information System (INIS)

    Mills, T. R.; McInteer, B. B.; Montoya, J. G.

    1988-01-01

    Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of these isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separation of 32 S vs. 34 S were 1.127 for H 2 S, 1.048 for COS, 0.838 for SF 4 , and 1.058 for CH 3 SH. Relative volatilities of 32 S vs. 34 S are 1.0006 for COS and 0.9976 for SF 4 . There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H 2 Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produced separated isotopes with an effect similar to that found for sulfur in SF 4 . 8 refs., 2 tabs

  3. Sulfur and selenium isotope separation by distillation

    International Nuclear Information System (INIS)

    Mills, T.R.; McInteer, B.B.; Montoya, J.G.

    1989-01-01

    Sulfur and selenium isotopes are used for labeled compounds and as precursors for radioisotope production; however, both limited availability and high costs are problems. A new method is needed for large-scale separation of theses isotopes. Experimental distillation columns were used to measure isotopic separations for sulfur and selenium compounds. The maximum total isotope separations of 32 S vs. 34 S were 1.127 for H 2 S, 1.048 for COS, 0.838 for SF 4 , and 1.058 for CH 3 SH. Relative volatilities of 32 S and 34 S are 1.0006 for COS and 0.9976 for SF 4 . There is a reverse isotope effect for carbon in COS. No isotopic separation was observed for dimethyl selenide. The lower mass selenium isotopes in H 2 Se are more volatile. Distillation is a promising method for separating sulfur isotopes on a production scale. Existing distillation technology produces separated isotopes with an effect similar to that found for sulfur in SF 4 . (author). 8 refs.; 2 tabs

  4. Separation of arsenic species by capillary electrophoresis with sample-stacking techniques

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zu Liang; Naidu, Ravendra [Adelaide Laboratory, CSIRO Land and Water, PMB2, 5064, Glen Osmond, SA (Australia); Lin, Jin-Ming [Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 100085, Beijing (China)

    2003-03-01

    A simple capillary zone electrophoresis procedure was developed for the separation of arsenic species (AsO{sub 2}{sup 2-}, AsO{sub 4}{sup 2-}, and dimethylarsinic acid, DMA). Both counter-electroosmotic and co-electroosmotic (EOF) modes were investigated for the separation of arsenic species with direct UV detection at 185 nm using 20 mmol L{sup -1} sodium phosphate as the electrolyte. The separation selectivity mainly depends on the separation modes and electrolyte pH. Inorganic anions (Cl{sup -}, NO{sub 2}{sup -}, NO{sub 3}{sup -} and SO{sub 4}{sup 2-}) presented in real samples did not interfere with arsenic speciation in either separation mode. To improve the detection limits, sample-stacking techniques, including large-volume sample stacking (LVSS) and field-amplified sample injection (FASI), were investigated for the preconcentration of As species in co-CZE mode. Less than 1 {mu}mol L{sup -1} of detection limits for As species were achieved using FASI. The proposed method was demonstrated for the separation and detection of As species in water. (orig.)

  5. Competitive separation of di- vs. mono-valent cations in electrodialysis: effects of the boundary layer properties.

    Science.gov (United States)

    Kim, Younggy; Walker, W Shane; Lawler, Desmond F

    2012-05-01

    In electrodialysis desalination, the boundary layer near ion-exchange membranes is the limiting region for the overall rate of ionic separation due to concentration polarization over tens of micrometers in that layer. Under high current conditions, this sharp concentration gradient, creating substantial ionic diffusion, can drive a preferential separation for certain ions depending on their concentration and diffusivity in the solution. Thus, this study tested a hypothesis that the boundary layer affects the competitive transport between di- and mono-valent cations, which is known to be governed primarily by the partitioning with cation-exchange membranes. A laboratory-scale electrodialyzer was operated at steady state with a mixture of 10mM KCl and 10mM CaCl(2) at various flow rates. Increased flows increased the relative calcium transport. A two-dimensional model was built with analytical solutions of the Nernst-Planck equation. In the model, the boundary layer thickness was considered as a random variable defined with three statistical parameters: mean, standard deviation, and correlation coefficient between the thicknesses of the two boundary layers facing across a spacer. Model simulations with the Monte Carlo method found that a greater calcium separation was achieved with a smaller mean, greater standard deviation, or more negative correlation coefficient. The model and experimental results were compared for the cationic transport number as well as the current and potential relationship. The mean boundary layer thickness was found to decrease from 40 to less than 10 μm as the superficial water velocity increased from 1.06 to 4.24 cm/s. The standard deviation was greater than the mean thickness at slower water velocities and smaller at faster water velocities. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Objective Assessment of Activity Limitation in Glaucoma with Smartphone Virtual Reality Goggles: A Pilot Study.

    Science.gov (United States)

    Goh, Rachel L Z; Kong, Yu Xiang George; McAlinden, Colm; Liu, John; Crowston, Jonathan G; Skalicky, Simon E

    2018-01-01

    To evaluate the use of smartphone-based virtual reality to objectively assess activity limitation in glaucoma. Cross-sectional study of 93 patients (54 mild, 22 moderate, 17 severe glaucoma). Sociodemographics, visual parameters, Glaucoma Activity Limitation-9 and Visual Function Questionnaire - Utility Index (VFQ-UI) were collected. Mean age was 67.4 ± 13.2 years; 52.7% were male; 65.6% were driving. A smartphone placed inside virtual reality goggles was used to administer the Virtual Reality Glaucoma Visual Function Test (VR-GVFT) to participants, consisting of three parts: stationary, moving ball, driving. Rasch analysis and classical validity tests were conducted to assess performance of VR-GVFT. Twenty-four of 28 stationary test items showed acceptable fit to the Rasch model (person separation 3.02, targeting 0). Eleven of 12 moving ball test items showed acceptable fit (person separation 3.05, targeting 0). No driving test items showed acceptable fit. Stationary test person scores showed good criterion validity, differentiating between glaucoma severity groups ( P = 0.014); modest convergence validity, with mild to moderate correlation with VFQ-UI, better eye (BE) mean deviation, BE pattern deviation, BE central scotoma, worse eye (WE) visual acuity, and contrast sensitivity (CS) in both eyes ( R = 0.243-0.381); and suboptimal divergent validity. Multivariate analysis showed that lower WE CS ( P = 0.044) and greater age ( P = 0.009) were associated with worse stationary test person scores. Smartphone-based virtual reality may be a portable objective simulation test of activity limitation related to glaucomatous visual loss. The use of simulated virtual environments could help better understand the activity limitations that affect patients with glaucoma.

  7. Improved Performance of Unsupervised Method by Renovated K-Means

    OpenAIRE

    Ashok, P.; Nawaz, G. M Kadhar; Elayaraja, E.; Vadivel, V.

    2013-01-01

    Clustering is a separation of data into groups of similar objects. Every group called cluster consists of objects that are similar to one another and dissimilar to objects of other groups. In this paper, the K-Means algorithm is implemented by three distance functions and to identify the optimal distance function for clustering methods. The proposed K-Means algorithm is compared with K-Means, Static Weighted K-Means (SWK-Means) and Dynamic Weighted K-Means (DWK-Means) algorithm by using Davis...

  8. Trends in Supersonic Separator design development

    Directory of Open Access Journals (Sweden)

    Altam Rami Ali

    2017-01-01

    Full Text Available Supersonic separator is a new technology with applications in hydrocarbon dew pointing and gas dehydration which can be used to condensate and separate water and heavy hydrocarbons from natural gas. Many researchers have studied the design, performance and efficiency, economic viability, and industrial applications of these separators. The purpose of this paper is to succinctly review recent progress in the design and application of supersonic separators and their limitations. This review has found that while several aspects of this study are well studied, considerable gaps within the published literature still exists in the areas such as turndown flexibility which is a critical requirement to cater for variation of mass flow and since almost all the available designs have a fixed geometry and therefore cannot be considered suitable for variable mass flow rate, which is a common situation in actual site. Hence, the focus needs to be more on designing a flexible geometry that can maintain a high separation efficiency regardless of inlet conditions and mass flow variations. This review is focusing only on the design and application of the supersonic separators without going through the experimental facilities, industrial platform, pilot plants as well as theoretical, analytical, and numerical modelling.

  9. A Microsoft® Excel Simulation Illustrating the Central Limit Theorem's Appropriateness for Comparing the Difference between the Means of Any Two Populations

    Science.gov (United States)

    Moen, David H.; Powell, John E.

    2008-01-01

    Using Microsoft® Excel, several interactive, computerized learning modules are developed to illustrate the Central Limit Theorem's appropriateness for comparing the difference between the means of any two populations. These modules are used in the classroom to enhance the comprehension of this theorem as well as the concepts that provide the…

  10. Survey of Umbilical Cord care and Separation time in Healthy ...

    African Journals Online (AJOL)

    Background: The interval between delivery and umbilical cord separation varies worldwide. Some maternal, foetal and perinatal factors including cord care practices are known to affect this interval. Objectives: To establish the mean umbilical cord separation time and the effect of maternal and infant characteristics, perinatal ...

  11. Separation of hydrogen isotopes for tritium waste removal

    International Nuclear Information System (INIS)

    Wilkes, W.R.

    1975-01-01

    A distillation cascade for separating hydrogen isotopes was simulated by means of a multicomponent, multistage computer code. A hypothetical test mixture containing equal atomic fractions of protium, deuterium and tritium, equilibrated to high temperature molecular concentrations was used as feed. The results show that a two-column cascade can be used to separate the protium from the tritium. Deuterium appears both in the protium and the tritium product streams. (auth)

  12. The meaning of different limiters relations for definig public transport routes capacity

    OpenAIRE

    Adam MOLECKI

    2007-01-01

    The mutual affecting of different limiters of capacity is a very important feature, which makes difficult the right appreciation of the transport systems. In most cases, there is no way to use procedures which define relations by correlation coefficients etc. Completely divergent character of limiters induce that only way of effective appreciation is modeling by Monte Carlo simulations.

  13. Isotope separation process

    International Nuclear Information System (INIS)

    Lyon, R.K.; Kaldor, A.

    1977-01-01

    In a method for the separation of isotopes of uranium in UF 6 , the UF 6 is subjected to ir radiation at a predetermined wavelength or set of wavelengths for less than 10 -3 sec in such a manner that at least 0.1% of the 235 UF 6 molecules absorb an energy of more than 2000 cm -1 . The excited UF 6 is then reacted with a gaseous reagent, F 2 , Cl 2 , or Br 2 , to produce a product which is then recovered by means known in the art

  14. The meaning of different limiters relations for definig public transport routes capacity

    Directory of Open Access Journals (Sweden)

    Adam MOLECKI

    2007-01-01

    Full Text Available The mutual affecting of different limiters of capacity is a very important feature, which makes difficult the right appreciation of the transport systems. In most cases, there is no way to use procedures which define relations by correlation coefficients etc. Completely divergent character of limiters induce that only way of effective appreciation is modeling by Monte Carlo simulations.

  15. Content Progressive Coding of Limited Bits/pixel Images

    DEFF Research Database (Denmark)

    Jensen, Ole Riis; Forchhammer, Søren

    1999-01-01

    A new lossless context based method for content progressive coding of limited bits/pixel images is proposed. Progressive coding is achieved by separating the image into contelnt layers. Digital maps are compressed up to 3 times better than GIF.......A new lossless context based method for content progressive coding of limited bits/pixel images is proposed. Progressive coding is achieved by separating the image into contelnt layers. Digital maps are compressed up to 3 times better than GIF....

  16. Oil-water separators for use in ships

    Energy Technology Data Exchange (ETDEWEB)

    Parry, G.; Nuttall, P.J.

    1978-11-04

    After ratification by the United Nations Assembly of the 15 ppm limit for the oil content in water discharges from ships, as recommended by the Intergovernmental Maritime Consultative Organization, all oil separating systems used to treat cargo tank washings, oil-contaminated ballast water from double-bottom tanks, engineroom bilge water, or oily sludge from self-cleaning fuel oil purifiers, will be subjected to a stringent test procedure specified by IMCO. This specification requires the use of centrifugal supply pumps capable of discharging at 1.5 times the separator capacity and operating at over 1000 rpm. To meet the 15 ppm standards, filtration or coalescence equipment must be added to conventional single-stage static separators. Tests by Alexander Esplen and Co. Ltd. showed that a two-stage Comyn coagulator incorporating elements specially designed by Vokes Ltd. meets the IMCO requirements. Separator system control and maintenance problems are discussed.

  17. Isotope separation of 22Na and 24Na with using light induced drift effect

    International Nuclear Information System (INIS)

    Hradecny, C.; Tethal, T.; Ermolaev, I.M.; Zemlyanoj, S.G.; Zuzaan, P.

    1993-01-01

    The LIDIS (Light Drift Isotope Separation) separator without a gas flow is discussed. It is shown, that atomization degree of the separated isotopes limited real separation coefficient. The better buffer gas purification allowed to increase the experimental separation factor of 22 Na and 24 Na isotopes up to 25. The new experimental set up allow to increase the separation efficiency up to 50%. 12 refs.; 5 figs

  18. Mean-field theory and solitonic matter

    International Nuclear Information System (INIS)

    Cohen, T.D.

    1989-01-01

    Finite density solitonic matter is considered in the context of quantum field theory. Mean-field theory, which provides a reasonable description for single-soliton properties gives rise to a crystalline description. A heuristic description of solitonic matter is given which shows that the low-density limit of solitonic matter (the limit which is presumably relevant for nuclear matter) does not commute with the mean-field theory limit and gives rise to a Fermi-gas description of the system. It is shown on the basis of a formal expansion of simple soliton models in terms of the coupling constant why one expects mean-field theory to fail at low densities and why the corrections to mean-field theory are nonperturbative. This heuristic description is tested against an exactly solvable 1+1 dimensional model (the sine-Gordon model) and found to give the correct behavior. The relevance of these results to the program of doing nuclear physics based on soliton models is discussed. (orig.)

  19. Discussing Firearm Ownership and Access as Part of Suicide Risk Assessment and Prevention: "Means Safety" versus "Means Restriction".

    Science.gov (United States)

    Stanley, Ian H; Hom, Melanie A; Rogers, Megan L; Anestis, Michael D; Joiner, Thomas E

    2017-01-01

    The goal of this study was to describe the relative utility of the terms "means safety" versus "means restriction" in counseling individuals to limit their access to firearms in the context of a mock suicide risk assessment. Overall, 370 participants were randomized to read a vignette depicting a clinical scenario in which managing firearm ownership and access was discussed either using the term "means safety" or "means restriction." Participants rated the term "means safety" as significantly more acceptable and preferable than "means restriction." Participants randomized to the "means safety" condition reported greater intentions to adhere to clinicians' recommendations to limit access to a firearm for safety purposes (F[1,367] = 7.393, p = .007, [Formula: see text]). The term "means safety" may be more advantageous than "means restriction" when discussing firearm ownership and access in clinical settings and public health-oriented suicide prevention efforts.

  20. Continuous separation of colloidal particles using dielectrophoresis.

    Science.gov (United States)

    Yunus, Nurul Amziah Md; Nili, Hossein; Green, Nicolas G

    2013-04-01

    Dielectrophoresis is the movement of particles in nonuniform electric fields and has been of interest for application to manipulation and separation at and below the microscale. This technique has the advantages of being noninvasive, nondestructive, and noncontact, with the movement of particle achieved by means of electric fields generated by miniaturized electrodes and microfluidic systems. Although the majority of applications have been above the microscale, there is increasing interest in application to colloidal particles around a micron and smaller. This paper begins with a review of colloidal and nanoscale dielectrophoresis with specific attention paid to separation applications. An innovative design of integrated microelectrode array and its application to flow-through, continuous separation of colloidal particles is then presented. The details of the angled chevron microelectrode array and the test microfluidic system are then discussed. The variation in device operation with applied signal voltage is presented and discussed in terms of separation efficiency, demonstrating 99.9% separation of a mixture of colloidal latex spheres. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. SEPARATION OF HAFNIUM FROM ZIRCONIUM

    Science.gov (United States)

    Overholser, L.B.; Barton, C.J. Sr.; Ramsey, J.W.

    1960-05-31

    The separation of hafnium impurities from zirconium can be accomplished by means of organic solvent extraction. The hafnium-containing zirconium feed material is dissolved in an aqueous chloride solution and the resulting solution is contacted with an organic hexone phase, with at least one of the phases containing thiocyanate. The hafnium is extracted into the organic phase while zirconium remains in the aqueous phase. Further recovery of zirconium is effected by stripping the onganic phase with a hydrochloric acid solution and commingling the resulting strip solution with the aqueous feed solution. Hexone is recovered and recycled by means of scrubbing the onganic phase with a sulfuric acid solution to remove the hafnium, and thiocyanate is recovered and recycled by means of neutralizing the effluent streams to obtain ammonium thiocyanate.

  2. Edge separation using diffraction anomalous fine structure

    International Nuclear Information System (INIS)

    Ravel, B.; Bouldin, C.E.; Renevier, H.; Hodeau, J.L.; Berar, J.F.

    1999-01-01

    We exploit the crystallographic sensitivity of the Diffraction Anomalous Fine-Structure (DAFS) measurement to separate the fine structure contributions of different atomic species with closely spaced resonant energies. In BaTiO 3 the Ti K edge and Ba Lm edges are separated by 281 eV, or about 8.2 Angstrom -1 ), thus severely limiting the information content of the Ti K edge signal. Using the site selectivity of DAFS we can separate the two fine structure spectra using an iterative Kramers-Kronig method, thus extending the range of the Ti K edge spectrum. This technique has application to many rare earth/transition metal compounds, including many magnetic materials of technological significance for which K and L edges overlap in energy. (au)

  3. Short Remarks on the Principle of Separation of Powers

    Directory of Open Access Journals (Sweden)

    Ionela Despa

    2012-05-01

    Full Text Available The principle of separation of powers, as a basic principle of a real democratic political system,concerns that state activities, powers are separated by the fact that they take place separately, distinct fromone another, each with its specific, but in the social polical reality it can be seen that there are linksbetween public authorities in terms of organizational and functional, namely cooperation and mutualdeterminations. In terms of organization, the link is given by the fact that some state bodies involved in theformation of other, and the functional aspect concerns the connection of collaborations: theconstitutionality of laws passed by Parliament is controlled by the Constitutional Court or Governmentactivity can be examined by Parliament. The modern form of the principle of separation of powers requiresautonomous public authorities, sharing their incumbent functions, establishment of means of cooperationand mutual control, all in the ambience of a genuine and real autonomy. So a state cannot work unless thelaw adopted by thelegislature is applied to urge the executive and the judiciary by the executive contestcarries out its decisions. This cooperation should be accompanied by a power control, equipped with legaland institutional means that will not neutralize eachother.

  4. Far-Field Superresolution of Thermal Electromagnetic Sources at the Quantum Limit.

    Science.gov (United States)

    Nair, Ranjith; Tsang, Mankei

    2016-11-04

    We obtain the ultimate quantum limit for estimating the transverse separation of two thermal point sources using a given imaging system with limited spatial bandwidth. We show via the quantum Cramér-Rao bound that, contrary to the Rayleigh limit in conventional direct imaging, quantum mechanics does not mandate any loss of precision in estimating even deep sub-Rayleigh separations. We propose two coherent measurement techniques, easily implementable using current linear-optics technology, that approach the quantum limit over an arbitrarily large range of separations. Our bound is valid for arbitrary source strengths, all regions of the electromagnetic spectrum, and for any imaging system with an inversion-symmetric point-spread function. The measurement schemes can be applied to microscopy, optical sensing, and astrometry at all wavelengths.

  5. Element for separating gaseous isotopes into at least two fractions and with a separating basket consisting of several separating elements

    International Nuclear Information System (INIS)

    Grossstuck, W.; Schafer, R.

    1985-01-01

    A separating element for gaseous isotopes into two fractions, and consisting of several elongated separating chips with a row of entry openings for the process gas at one side of the chips and a row of exit openings for the heavy fraction at the other side of the chips, with exit openings for the light fraction at the edges of the chips, and of two tubes holding the chips and having at least one chamber, with said tubes being connected by means of connecting elements, and equipped with entry and exit openings on their contact surfaces, with said entry and exit openings arranged in rows in a longitudinal direction of the chips, and for simplifying of installation and construction, this invention provides that the chips are arranged in a longitudinal direction to the tubes, with their sides abutting directly against the smooth contact surfaces of the tubes, and whereby the connecting elements are positioned in one row in the center of the two tubes

  6. Classroom Research: Assessment of Student Understanding of Sampling Distributions of Means and the Central Limit Theorem in Post-Calculus Probability and Statistics Classes

    Science.gov (United States)

    Lunsford, M. Leigh; Rowell, Ginger Holmes; Goodson-Espy, Tracy

    2006-01-01

    We applied a classroom research model to investigate student understanding of sampling distributions of sample means and the Central Limit Theorem in post-calculus introductory probability and statistics courses. Using a quantitative assessment tool developed by previous researchers and a qualitative assessment tool developed by the authors, we…

  7. Separation of aromatics by vapor permeation through solvent swollen membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ito, A.; Adachi, K.; Feng, Y. [Niigata University, Niigata (Japan)

    1995-12-20

    A vapor permeation process for aromatics separation from a hydrocarbon mixture was studied by means of the simultaneous permeation of dimethylsulfoxide vapor as an agent for membrane swelling and preferential permeation of aromatics. The separation performance of the process was demonstrated by a polyvinylalcohol membrane for mixed vapors of benzene/cyclohexane, xylene/octane and a model gasoline. The aromatic vapors preferentially permeated from these mixed vapor feeds. The separation factor was over 10. The separation mechanism of the process mainly depends on the relative salability of the vapors between aromatics and other hydrocarbons in dimethylsulfoxide. 14 refs., 9 figs., 1 tab.

  8. Waste classifying and separation device

    International Nuclear Information System (INIS)

    Kakiuchi, Hiroki.

    1997-01-01

    A flexible plastic bags containing solid wastes of indefinite shape is broken and the wastes are classified. The bag cutting-portion of the device has an ultrasonic-type or a heater-type cutting means, and the cutting means moves in parallel with the transferring direction of the plastic bags. A classification portion separates and discriminates the plastic bag from the contents and conducts classification while rotating a classification table. Accordingly, the plastic bag containing solids of indefinite shape can be broken and classification can be conducted efficiently and reliably. The device of the present invention has a simple structure which requires small installation space and enables easy maintenance. (T.M.)

  9. New separation technique. Catalytically functionated separation membrane

    Energy Technology Data Exchange (ETDEWEB)

    Urgami, Tadashi [Kansai Univ., Osaka (Japan)

    1989-02-01

    This report introduces research examples, showing the fundamental principle of the membrane by separating the catalytically functionated separation membrane into enzyme fixing separation membrane, polymerized metal complex separation membrane and polymer catalyst separation membrane. This membrane can achieve both functions of separation and catalytic reaction simultaneously and has sufficient possibility to combine powerful functions. Enzyme fixing separation membrane is prepared by carrier combination method, bridging method or covering method and the enzyme fixing method with polymerized complex in which enzyme is controlled to prevent the activity lowering as much as possible and enzyme is fixed from an aqueous solution into polymer membrane. This membrane is applied to the continuous manufacturing of invert sugar from cane sugar and adsorption and removing of harmful substances from blood by utilizing both micro-capsuled urease and active carbon. Alginic acid-copper (II) complex membrane is used for the polymerized metal complex membrane and polystyrene sulfonate membrane is used for the polymer catalyst separation membrane. 28 refs., 4 figs., 1 tabs.

  10. Experimental distribution of entanglement with separable carriers

    Science.gov (United States)

    Fedrizzi, Alessandro; Zuppardo, Margherita; Gillett, Geoff; Broome, Matthew; de Almeida, Marcelo; Paternostro, Mauro; White, Andrew; Paterek, Tomasz

    2014-03-01

    Quantum networks will allow us to overcome distance limitations in quantum communication, and to share quantum computing tasks between remote quantum processors. The key requirement for quantum networking is the distribution of entanglement between nodes. Surprisingly, entanglement can be generated across a network without directly being communicated between nodes. In contrast to information gain, which cannot exceed the communicated information, the entanglement gain is bounded by the communicated quantum discord, a more general measure of quantum correlation that includes but is not limited to entanglement. Here we report an experiment in which two communicating parties who share three initially separable photonic qubits are entangled by exchange of a carrier photon that is not entangled with either party at all times. We show that distributing entanglement with separable carriers is resilient to noise and in some cases becomes the only way of distributing entanglement over noisy environments.

  11. Transport in simple liquids and dense gases: kinetic mean-field theory and the KAC limit

    International Nuclear Information System (INIS)

    Karkheck, J.; Stell, G.; Martina, E.

    1982-01-01

    Maximization of entropy is used in conjunction with the BBGKY hierarchy to obtain a closed one-particle kinetic equation. For an interparticle potential of hard-sphere core plus smooth attractive tail, this equation contains a hard-core collision integral, identical to that of the revised Enskog theory, plus a mean-field term which is linear in the tail strength. The thermodynamics contained therein leads directly to the now-standard statistical-mechanical methods to construct a state-dependent effective hard-core potential in relation to a more realistic potential. These methods induce an extension of the transport coefficients to the Lennard-Jones potential. Predictions of the resulting transport theory compare very favorably with thermal conductivity and shear viscosity experimental results for real simple liquids and dense gases, and also with molecular dynamics simulation results. Poor agreement between theory and experiment is found for moderately dense and dilute gases. The kinetic theory also contains an entropy functional and an H-theorem is proven. Extension to mixtures is straightforward and the Kac-limit is discussed in detail

  12. ALPHA-BETA SEPARATION PORTFOLIO STRATEGIES FOR ISLAMIC FINANCE

    OpenAIRE

    Valentyn Khokhlov

    2016-01-01

    The purpose of this paper is to develop a mathematical alpha-beta separation model that can be used to create a core-satellite portfolio management strategy that complies with the principles of Islamic finance. Methodology. Core-satellite portfolio construction methodology is used to implement the alpha-beta separation approach, where the core part of the portfolio is managed using the tracking error minimization strategy, and the satellite part of the portfolio is managed using the mean-vari...

  13. Tandem on-line continuous separations for atomic spectroscopic indirect analysis: iodide determination by ICP-AES

    International Nuclear Information System (INIS)

    Garcia, A.M.; Sanchez Uria, J.E.; Sanz-Medel, A.; Quintero Ortega, M.C.; Bautista, J.C.

    1992-01-01

    A sensitive and selective indirect determination of iodide by inductively coupled plasma emission spectrometry (ICP-AES) based on the principle of tandem on-line continuous separations as an alternative means of introducing samples into plasmas is proposed. Iodide is continuously extracted as an ion-pair into xylene by mixing the sample with Hg(II) and dipyridil solutions. The organic phase (containing the analyte in [Hg(Dipy) 2 ]I 2 form) is on-line continuously mixed with NaBH 4 (in DMF) and acetic acid solutions. Mercury vapour continuously generated from this organic phase is separated in a classical U-type gas-liquid separation device. The system has been optimized for the continuous extraction of KI, for the direct generation of cold mercury vapour from xylene and for the final ICP-AES determination of mercury. The optimised method has been applied to the determination of iodide (detection limit 20 ng/ml of iodide) in table salt and in synthetic samples. Very good agreement between found and certified results was observed. The usefulness and convenience of such alternative sample chemical pretreatment/presentation to the ICP is thus demonstrated for indirect determinations to be carried out by atomic spectroscopy methods. (authors)

  14. Stats means business

    CERN Document Server

    Buglear, John

    2010-01-01

    Stats Means Business is an introductory textbook written for Business, Hospitality and Tourism students who take modules on Statistics or Quantitative research methods. Recognising that most users of this book will have limited if any grounding in the subject, this book minimises technical language, provides clear definition of key terms, and gives emphasis to interpretation rather than technique.Stats Means Business enables readers to:appreciate the importance of statistical analysis in business, hospitality and tourism understand statis

  15. Electronic phase separation and high temperature superconductors

    International Nuclear Information System (INIS)

    Kivelson, S.A.

    1994-01-01

    The authors review the extensive evidence from model calculations that neutral holes in an antiferromagnet separate into hole-rich and hole-poor phases. All known solvable limits of models of holes in a Heisenberg antiferromagnet exhibit this behavior. The authors show that when the phase separation is frustrated by the introduction of long-range Coulomb interactions, the typical consequence is either a modulated (charge density wave) state or a superconducting phase. The authors then review some of the strong experimental evidence supporting an electronically-driven phase separation of the holes in the cuprate superconductors and the related Ni oxides. Finally, the authors argue that frustrated phase separation in these materials can account for many of the anomalous normal state properties of the high temperature superconductors and provide the mechanism of superconductivity. In particular, it is shown that the T-linear resistivity of the normal state is a paraconductivity associated with a novel composite pairing, although the ordered superconducting state is more conventional

  16. Oil/gas collector/separator for underwater oil leaks

    International Nuclear Information System (INIS)

    Henning, C.D.

    1993-01-01

    An oil/gas collector/separator for underwater oil leaks is described comprising: a cylindrical tank; a hollow float member for supporting said tank in a substantially upright position; a skirt assembly secured to said hollow float member and extending in a direction away from said float member opposite said tank; means for removing oil from said tank; and means for removing gas from said tank

  17. Estimation of process capability indices from the results of limit gauge inspection of dimensional parameters in machining industry

    Science.gov (United States)

    Masterenko, Dmitry A.; Metel, Alexander S.

    2018-03-01

    The process capability indices Cp, Cpk are widely used in the modern quality management as statistical measures of the ability of a process to produce output X within specification limits. The customer's requirement to ensure Cp ≥ 1.33 is often applied in contracts. Capability indices estimates may be calculated with the estimates of the mean µ and the variability 6σ, and for it, the quality characteristic in a sample of pieces should be measured. It requires, in turn, using advanced measuring devices and well-qualified staff. From the other hand, quality inspection by attributes, fulfilled with limit gauges (go/no-go) is much simpler and has a higher performance, but it does not give the numerical values of the quality characteristic. The described method allows estimating the mean and the variability of the process on the basis of the results of limit gauge inspection with certain lower limit LCL and upper limit UCL, which separates the pieces into three groups: where X control of the manufacturing process. It is very important for improving quality of articles in machining industry through their tolerance.

  18. The Classification of Diabetes Mellitus Using Kernel k-means

    Science.gov (United States)

    Alamsyah, M.; Nafisah, Z.; Prayitno, E.; Afida, A. M.; Imah, E. M.

    2018-01-01

    Diabetes Mellitus is a metabolic disorder which is characterized by chronicle hypertensive glucose. Automatics detection of diabetes mellitus is still challenging. This study detected diabetes mellitus by using kernel k-Means algorithm. Kernel k-means is an algorithm which was developed from k-means algorithm. Kernel k-means used kernel learning that is able to handle non linear separable data; where it differs with a common k-means. The performance of kernel k-means in detecting diabetes mellitus is also compared with SOM algorithms. The experiment result shows that kernel k-means has good performance and a way much better than SOM.

  19. The Theory of Separation of Powers in Nigeria: An Assessment ...

    African Journals Online (AJOL)

    The Theory of Separation of Powers means that, a different body of persons is to administer each of the three departments of government. That no one of them is to have a controlling power over either of the others. For the purpose of preserving the liberty of the individual and for avoiding tyranny separation of powers is ...

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    as a function of the retention volume, results for both linear and branched polyethylene molecules lie nearly on the master curve determined by linear polystyrene standards. Our findings support the equilibrium thermodynamic separation principle in SEC. Since the mean span dimension is a purely geometric size......The principle of polymer separation in size exclusion chromatography (SEC) is studied based on a classical equilibrium partitioning theory. The task is to examine the correlation between the mean span dimension of polymer chains and their equilibrium partition coefficients with confining pores...

  1. 78 FR 57790 - Extension of Time Limits

    Science.gov (United States)

    2013-09-20

    .... Thus, this modification makes explicit that parties may request extensions for any time limit... Department's attention more quickly, thus increasing the chance that the Department will be able to...; only if the questionnaire is divided into separate sections is the time limit for individual sections...

  2. Comparison of gas membrane separation cascades using conventional separation cell and two-unit separation cells

    International Nuclear Information System (INIS)

    Ohno, Masayoshi; Morisue, Tetsuo; Ozaki, Osamu; Miyauchi, Terukatsu.

    1978-01-01

    The adoption of two-unit separation cells in radioactive rare gas membrane separation equipment enhances the separation factor, but increases the required membrane area and compressive power. An analytical economic evaluation was undertaken to compare the conventional separation cell with the two-unit separation cells, adopting as parameters the number of cascade stages, the membrane area and the operating power requirements. This paper describes the models used for evaluating the separation performance and the economics of cascade embodying these different concepts of separation cell taken up for study, and the results obtained for the individual concepts are mutually compared. It proved that, in respect of the number required of cascade stages, of operating power requirements and of the annual expenditure, better performance could always be expected of the two-unit separation cells as compared with the conventional separation cell, at least in the range of parameters adopted in this study. As regards the minimum membrane area, the conventional separation cell and the series-type separation cell yielded almost the same values, with the parallel-type separation cell falling somewhat behind. (auth.)

  3. Chinese version of the separation-individuation inventory.

    Science.gov (United States)

    Tam, Wai-Cheong Carl; Shiah, Yung-Jong; Chiang, Shih-Kuang

    2003-08-01

    The importance of the separation-individuation process in object relations theory is well known in disciplines of psychology, counseling, and human development. Based on the Separation-Individuation Inventory of Christenson and Wilson, which measures the manifestations of disturbances in this process, a Chinese version of the inventory was developed. For college students Cronbach coefficient alpha was .89, and test-retest reliability over 28 days was .77. The scores of the inventory had positive correlations with both the number of borderline personality characteristics and the Individualism-Collectivism Scale, respectively. Also, the mean score on the inventory of patients diagnosed with borderline personality disorder was significantly higher than that of the two normal control groups (ns = 564). Thus the inventory possessed satisfactory construct validity. Cultural differences regarding the separation-individuation process need to be investigated further.

  4. Separation of Ra/Ca by ion exchange

    International Nuclear Information System (INIS)

    Iturbe, J.L.; Jimenez R, M.; Flores M, J.

    1991-04-01

    The radium and the calcium belong to the same group in the periodic classification and as consequence both they present very similar chemical properties, that makes difficult its separation. Both elements are also frequently associate in the nature, the calcium is very abundant, the radium is not it and for that reason it is indispensable its separation to analyze to this last one. The alpha spectroscopy is very appropriate to analyze to the 226 Ra, however to achieve a good resolution of the spectra, the samples should contain small quantities of calcium. The purposes of this work were to know the chromatographic behavior of the alkaline-earthy cations: calcium, barium and radium and to apply these knowledge to the separation of the 226 Ra and its analysis by means of alpha spectroscopy. (Author)

  5. Nuclear Gamma-Ray Spectroscopy at the Limit of Particle Stability

    International Nuclear Information System (INIS)

    Dr. Norbert Pietralla

    2006-01-01

    The research project ''Nuclear Gamma-Ray Spectroscopy at the Limit of Particle Stability'' with sponsor ID ''DE-FG02-04ER41334'' started late-summer 2004 and aims at the investigation of highly excited low-spin states of selected key-nuclei in the vicinity of the particle separation threshold by means of high-resolution gamma-ray spectroscopy in electromagnetic excitation reactions. This work addresses nuclear structures with excitation energies close to the binding energy or highly excited off-yrast states in accordance with the NSAC milestones. In 2005 the program was extended towards additional use of virtual photons and theoretical description of the low-lying collective excitations in the well deformed nuclei

  6. Centrifugal gas separator

    Energy Technology Data Exchange (ETDEWEB)

    Kanagawa, A; Fujii, O; Nakamoto, H

    1970-03-09

    Counter currents in the rotary drum of a centrifugal gas separator are produced by providing, at either end of the drum in the vicinity of the circumferential and central positions, respectively, outflow and inflow holes with a communicating passage external to the drum there between whereby gaseous counter currents are caused to flow within the drum and travel through the passage which is provided with gas flow adjustment means. Furthermore, the space defined by the stationary portion of the passage and the rotor drum is additionally provided with a screw pump or throttling device at either its stationary side or drum side or both in order to produce a radially directed gas flow therewithin. A gas mixture is axially admitted into the drum while centrifugal force and a cooling element provided therebelow cause an increase in gas pressure along and a gaseous flow toward the wall member, whereupon the comparatively high pressured circumferentially distributed gas is extracted from the outlet holes, flows through the external gas passage and back into the lower pressured drum core through the inlet holes, thus producing the desired counter currents. The gases thus separated are withdrawn along axially provided discharge pipes. Accordingly, this invention permits heating elements which were formerly used to produce thermal convection currents to be disposed of and allows the length of the rotor drum to be more efficiently utilized to enhance separation efficiency.

  7. Radiochemical Means of Investigating Delayed Neutron Precursors

    International Nuclear Information System (INIS)

    Marmol, P. del

    1968-01-01

    Fast radiochemical methods used now for the determination of delayed neutron precursors are classified and reviewed: precipitations, solvent extractions, range experiments, milking, gas sweeping, isotopic and ion exchange, hot atom reactions and diffusion loss. Advantages and limitations of irradiation systems with respect to fast separations are discussed: external beams which allow faster separations only have low neutron fluxes, internal beams which are mostly fit for gaseous reactions; and rabbits for solution irradiations. Future prospects of radiochemical procedures are presented; among these, studies should be mostly oriented towards gaseous reactions which offer possibilities of isolating very short-lived delayed neutron precursors. Chemical procedures for delayed neutron precursor detection are compared with mass spectrometric and isotope separator techniques; it is concluded that the methods are complementary. (author)

  8. Radiochemical Means of Investigating Delayed Neutron Precursors

    International Nuclear Information System (INIS)

    Marmol, P. del

    1968-01-01

    Fast radiochemical methods used now for the determination of delayed neutron precursors are classified and reviewed: precipitations, solvent extractions, range experiments, milking, gas sweeping, isotopic and ion exchange, hot-atom reactions and diffusion loss. Advantages and limitations of irradiation systems with respect to fast separations are discussed: external beams which allow faster separations only have low neutron fluxes, internal beams which are mostly fit for gaseous reactions; and rabbits for solution irradiations. Future prospects of radiochemical procedures are presented; among these, studies should be mostly oriented towards gaseous reactions which offer possibilities of isolating very short-lived delayed neutron precursors. Chemical procedures for delayed neutron precursor detection are compared with mass spectrometric and isotope-separator techniques; it is concluded that the methods are complementary. (author)

  9. Higher-order asymptotic homogenization of periodic materials with low scale separation

    NARCIS (Netherlands)

    Ameen, M.M.; Peerlings, R.H.J.; Geers, M.G.D

    2016-01-01

    In this work, we investigate the limits of classical homogenization theories pertaining to homogenization of periodic linear elastic composite materials at low scale separations and demonstrate the effectiveness of higher-order periodic homogenization in alleviating this limitation. Classical

  10. Advanced Aqueous Separation Systems for Actinide Partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Nash, Ken [Washington State Univ., Pullman, WA (United States); Martin, Leigh [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lumetta, Gregg [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-04-02

    One of the most challenging aspects of advanced processing of used nuclear fuel is the separation of transplutonium actinides from fission product lanthanides. This separation is essential if actinide transmutation options are to be pursued in advanced fuel cycles, as lanthanides compete with actinides for neutrons in both thermal and fast reactors, thus limiting efficiency. The separation is difficult because the chemistry of Am3+ and Cm3+ is nearly identical to that of the trivalent lanthanides (Ln3+). The prior literature teaches that two approaches offer the greatest probability of devising a successful group separation process based on aqueous processes: 1) the application of complexing agents containing ligand donor atoms that are softer than oxygen (N, S, Cl-) or 2) changing the oxidation state of Am to the IV, V, or VI state to increase the essential differences between Am and lanthanide chemistry (an approach utilized in the PUREX process to selectively remove Pu4+ and UO22+ from fission products). The latter approach offers the additional benefit of enabling a separation of Am from Cm, as Cm(III) is resistant to oxidation and so can easily be made to follow the lanthanides. The fundamental limitations of these approaches are that 1) the soft(er) donor atoms that interact more strongly with actinide cations than lanthanides form substantially weaker bonds than oxygen atoms, thus necessitating modification of extraction conditions for adequate phase transfer efficiency, 2) soft donor reagents have been seen to suffer slow phase transfer kinetics and hydro-/radiolytic stability limitations and 3) the upper oxidation states of Am are all moderately strong oxidants, hence of only transient stability in media representative of conventional aqueous separations systems. There are examples in the literature of both approaches having been described. However, it is not clear at present that any extant process is sufficiently robust for application at the scale

  11. Pushing the limits of NAA. Accuracy, uncertainty and detection limits

    International Nuclear Information System (INIS)

    Greenberg, R.R.

    2008-01-01

    This paper describes some highlights from the author's efforts to improve neutron activation analysis (NAA) detection limits through development and optimization of radiochemical separations, as well as to improve the overall accuracy of NAA measurements by identifying, quantifying and reducing measurement biases and uncertainties. Efforts to demonstrate the metrological basis of NAA, and to establish it as a 'Primary Method of Measurement' will be discussed. (author)

  12. Chromatographic separation of metal ions by means of paper treated with trioctyl - phosphate, Annex 7

    Energy Technology Data Exchange (ETDEWEB)

    Cvjeticanin, N M; Cvoric, J D; Obrenovic-Paligoric, I D [Institute of Nuclear Sciences Boris Kidric, Laboratorija za visoku aktivnost, Vinca, Beograd (Serbia and Montenegro)

    1963-12-15

    This chromatographic behaviour of uranium, thorium and some other metal ions and long-lived fission products was investigated on paper treated with trioctyl-phosphate. Hydrochloric, nitric, sulphuric and perchloric acids in concentrations of 0.1-10 N were used as the elution agents. The R{sub f} values of the ions investigated, which show the possibility of the inter separation of some cations, are given as a function of the concentration of acids (author)

  13. Two Populations Mean-Field Monomer-Dimer Model

    Science.gov (United States)

    Alberici, Diego; Mingione, Emanuele

    2018-04-01

    A two populations mean-field monomer-dimer model including both hard-core and attractive interactions between dimers is considered. The pressure density in the thermodynamic limit is proved to satisfy a variational principle. A detailed analysis is made in the limit of one population is much smaller than the other and a ferromagnetic mean-field phase transition is found.

  14. 5 CFR 2641.302 - Separate agency components.

    Science.gov (United States)

    2010-01-01

    ... Section 2641.302 Administrative Personnel OFFICE OF GOVERNMENT ETHICS GOVERNMENT ETHICS POST-EMPLOYMENT... Office of Government Ethics may designate agency “components” that are distinct and separate from the... factors which may include, but are not limited to: (i) The component's creation by statute or a statutory...

  15. A Review of Function Allocation and En Route Separation Assurance

    Science.gov (United States)

    Lewis, Timothy A.; Aweiss, Arwa S.; Guerreiro, Nelson M.; Daiker, Ronald J.

    2016-01-01

    Today's air traffic control system has reached a limit to the number of aircraft that can be safely managed at the same time. This air traffic capacity bottleneck is a critical problem along the path to modernization for air transportation. The design of the next separation assurance system to address this problem is a cornerstone of air traffic management research today. This report reviews recent work by NASA and others in the areas of function allocation and en route separation assurance. This includes: separation assurance algorithms and technology prototypes; concepts of operations and designs for advanced separation assurance systems; and specific investigations into air-ground and human-automation function allocation.

  16. Simulation of startup period of hydrogen isotope separation distillation column

    International Nuclear Information System (INIS)

    Sazonov, A.B.; Kagramanov, Z.G.; Magomedbekov, Eh.P.

    2003-01-01

    Kinetic procedure for the mathematical simulation of start-up regime of rectification columns for molecular hydrogen isotope separation was developed. Nonstationary state (start-up period) of separating column for rectification of multi-component mixture was calculated. Full information on equilibrium and kinetic physicochemical properties of components in separating mixtures was used for the calculations. Profile of concentration of components by height of column in task moment of time was calculated by means of differential equilibriums of nonstationary mass transfer. Calculated results of nonstationary state of column by the 2 m height, 30 mm diameter during separation of the mixture: 5 % protium, 70 % deuterium, 25 % tritium were illustrated [ru

  17. Continuous spin mean-field models : Limiting kernels and Gibbs properties of local transforms

    NARCIS (Netherlands)

    Kulske, Christof; Opoku, Alex A.

    2008-01-01

    We extend the notion of Gibbsianness for mean-field systems to the setup of general (possibly continuous) local state spaces. We investigate the Gibbs properties of systems arising from an initial mean-field Gibbs measure by application of given local transition kernels. This generalizes previous

  18. 9 CFR 381.174 - Limitations with respect to use of Mechanically Separated (Kind of Poultry).

    Science.gov (United States)

    2010-01-01

    ... Mechanically Separated (Kind of Poultry). 381.174 Section 381.174 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE AGENCY ORGANIZATION AND TERMINOLOGY; MANDATORY MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION POULTRY PRODUCTS INSPECTION REGULATIONS...

  19. Separation, storage and disposal of krypton-85

    International Nuclear Information System (INIS)

    1980-01-01

    Technical means available for the retention of 85 Kr and its immobilization, storage and disposal are reviewed. Cryogenic processes for the separation of krypton and xenon from diluting gases are discussed in more detail. Besides the cryogenic processes, a liquid adsorption process for reprocessing off-gases and charcoal adsorption and membrane processes for reactor off-gases are also dealt with. The retained krypton can be stored in pressurized containers with air or water cooling. The containers can be kept in engineered storage facilities for an intermediate period or until the 85 Kr has decayed. Alternatively, the krypton may be encapsulated in a solid. The injection of gases containing krypton into suitable geologic strata may also be possible. Much of the equipment required for the separation and storage of krypton, well known from ordinary technology, often needs some adaptation. Further R and D work is, however, needed to solve some problems which are specific to highly concentrated fission krypton. The subject is reviewed under the following headings: methods available for the separation of krypton from off-gases; separation of krypton from reactor off-gas; separation of krypton from reprocessing off-gas; conditioning methods; engineering storage; transportation; disposal

  20. Study of the separation of metallic compounds by means of an anion exchanger resin and of complexing media

    International Nuclear Information System (INIS)

    Denis de Trobriand, Anne

    1971-01-01

    In order to define better separation conditions of molybdenum and aluminium from uranium alloys, this research thesis first reports the study of the fixation of each of these elements on a Dowex resin in a carbonate medium. Results obtained by other studies in a hydrogen carbonate medium has leaded to the use of mixing of CO 3 2- and HCO 3 - . In a last part, the author reports the analysis of two samples (uranium-molybdenum and uranium-aluminium): after an attack of these alloys in a melt carbonate medium, components are separated by elution in one of the studied media

  1. Optimization of the gas chromatographic separations

    International Nuclear Information System (INIS)

    Gasco Sanchez, L.

    1973-01-01

    A review and a critical study on the optimization of the gas chromatographic separations are made. After dealing with the fundamental gas chromatographic equations, some methods of expressing column performances are discussed: performance indices, performance parameters, resolution and effective plate number per unit time. This is completed with a comparative study on performances of various types of columns. Moreover, optimization methods for operating chromatographic conditions are extensively dealt with: as resolution optimization, separation time, and normalization techniques for the time of analysis in order to achieve the maximum resolution at constant time. Finally, some others non operating parameters such as: selectivity of stationary phases, column preparation and optimization methods by means of computers are studied. (Author) 68 refs

  2. A drier unit for steam separators

    International Nuclear Information System (INIS)

    Peyrelongue, J.-P.

    1973-01-01

    Description is given of a drier unit adapted to equip a water separator mounted in a unit for treating a wet steam fed from a high pressure enclosure, so as to dry and contingently superheat said steam prior to injecting same into a turbine low pressure stage. This drier unit is constituted by at least a stack of separating sheets maintained in parallel relationship and at a slight angle with respect to the horizontal so as to allow the water provided by wet steam to flow toward a channel communicating with a manifold, and by means for guiding the steam between the sheets and evenly distributing it. This can be applied to steam turbines in nuclear power stations [fr

  3. Separation of finest dusts in Venturi scrubber with hybrid nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Reither, K. [Reither Venturiwaescher GmbH, Troisdorf (Germany); Boerger, G.G.; Listner, U.; Schweitzer, M. [Bayer AG, Leverkusen (Germany)

    2001-03-01

    Venturi scrubbers are high-performance dust separators whose efficiency is closely connected with high pressure losses. The tube-slot Venturi scrubber with hybrid nozzles is a novel scrubber type of simple and compact design, by means of which high separation efficiency is reached with pressure losses practically tending to zero. This new wet scrubber is particularly suitable for refitting existing plants. (orig.)

  4. Effects of free-stream turbulence intensity on transition in a laminar separation bubble formed over an airfoil

    Science.gov (United States)

    Istvan, Mark S.; Yarusevych, Serhiy

    2018-03-01

    The laminar-to-turbulent transition process in a laminar separation bubble formed over a NACA 0018 airfoil is investigated experimentally. All experiments are performed for an angle of attack of 4°, chord Reynolds numbers of 80,000 and 125,000, and free-stream turbulence intensities between 0.06 and 1.99%. The results show that increasing the level of free-stream turbulence intensity leads to a decrease in separation bubble length, attributed to a downstream shift in mean separation and an upstream shift in mean reattachment, the later ascribed to an upstream shift in mean transition. Maximum spatial amplification rates of disturbances in the separated shear layer decrease with increasing free-stream turbulence intensity, implying that the larger initial amplitudes of disturbances are solely responsible for the upstream shift in mean transition and as a result mean reattachment. At the baseline level of turbulence intensity, coherent structures forming in the aft portion of the bubble are characterized by strong spanwise coherence at formation, and undergo spanwise deformations leading to localized breakup in the vicinity of mean reattachment. As the level of free-stream turbulence intensity is increased, the spanwise coherence of the shear layer rollers is reduced, and spanwise undulations in the vortex filaments start to take place at the mean location of roll-up. At the highest level of turbulence intensity investigated, streamwise streaks originating in the boundary layer upstream of the separation bubble are observed within the bubble. These streaks signify an onset of bypass transition upstream of the separation bubble, which gives rise to a highly three-dimensional shear layer roll-up. A quantitative analysis of the associated changes in salient characteristics of the coherent structures is presented, connecting the effect of elevated free-stream turbulence intensity on the time-averaged and dynamic characteristics of the separation bubble.

  5. Limiting global-mean temperature increase to 1.5–2 °C could reduce the incidence and spatial spread of dengue fever in Latin America

    Science.gov (United States)

    Harris, Ian; Osborn, Timothy J.; Steiner São Bernardo, Christine; Peres, Carlos A.; Lake, Iain R.

    2018-01-01

    The Paris Climate Agreement aims to hold global-mean temperature well below 2 °C and to pursue efforts to limit it to 1.5 °C above preindustrial levels. While it is recognized that there are benefits for human health in limiting global warming to 1.5 °C, the magnitude with which those societal benefits will be accrued remains unquantified. Crucial to public health preparedness and response is the understanding and quantification of such impacts at different levels of warming. Using dengue in Latin America as a study case, a climate-driven dengue generalized additive mixed model was developed to predict global warming impacts using five different global circulation models, all scaled to represent multiple global-mean temperature assumptions. We show that policies to limit global warming to 2 °C could reduce dengue cases by about 2.8 (0.8–7.4) million cases per year by the end of the century compared with a no-policy scenario that warms by 3.7 °C. Limiting warming further to 1.5 °C produces an additional drop in cases of about 0.5 (0.2–1.1) million per year. Furthermore, we found that by limiting global warming we can limit the expansion of the disease toward areas where incidence is currently low. We anticipate our study to be a starting point for more comprehensive studies incorporating socioeconomic scenarios and how they may further impact dengue incidence. Our results demonstrate that although future climate change may amplify dengue transmission in the region, impacts may be avoided by constraining the level of warming. PMID:29844166

  6. Determination of the stability limit of a thermoacoustic engine by means of finite elements

    NARCIS (Netherlands)

    de Jong, Anne; Wijnant, Ysbrand H.; de Boer, Andries

    2013-01-01

    A finite element model is presented to obtain the stability limit of, as an example, 2D standing wave thermoacoustic engine. The stability limit is the required heating to obtain self-sustained (thermo)acoustic oscillations. The method used to obtain the stability limit is not restricted to the

  7. Use of a pressure sensing sheath: comparison with standard means of blood pressure monitoring in catheterization procedures.

    Science.gov (United States)

    Purdy, Phillip D; South, Charles; Klucznik, Richard P; Liu, Kenneth C; Novakovic, Robin L; Puri, Ajit S; Pride, G Lee; Aagaard-Kienitz, Beverly; Ray, Abishek; Elliott, Alan C

    2017-08-01

    Monitoring of blood pressure (BP) during procedures is variable, depending on multiple factors. Common methods include sphygmomanometer (BP cuff), separate radial artery catheterization, and side port monitoring of an indwelling sheath. Each means of monitoring has disadvantages, including time consumption, added risk, and signal dampening due to multiple factors. We sought an alternative approach to monitoring during procedures in the catheterization laboratory. A new technology involving a 330 µm fiberoptic sensor embedded in the wall of a sheath structure was tested against both radial artery catheter and sphygmomanometer readings obtained simultaneous with readings recorded from the pressure sensing system (PSS). Correlations and Bland-Altman analysis were used to determine whether use of the PSS could substitute for these standard techniques. The results indicated highly significant correlations in systolic, diastolic, and mean arterial pressures (MAP) when compared against radial artery catheterization (p<0.0001), and MAP means differed by <4%. Bland-Altman analysis of the data suggested that the sheath measurements can replace a separate radial artery catheter. While less striking, significant correlations were seen when PSS readings were compared against BP cuff readings. The PSS has competitive functionality to that seen with a dedicated radial artery catheter for BP monitoring and is available immediately on sheath insertion without the added risk of radial catheterization. The sensor is structurally separated from the primary sheath lumen and readings are unaffected by device introduction through the primary lumen. Time delays and potential complications from radial artery catheterization are avoided. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. Flocking dynamics and mean-field limit in the Cucker-Smale-type model with topological interactions

    KAUST Repository

    Haskovec, Jan

    2013-01-01

    separating them. This makes the model scale-free and is motivated by recent extensive observations of starling flocks, suggesting that the interaction ruling animal collective behavior depends on topological rather than the metric distance. We study

  9. Separation of rare earths by means of acid organophosphorous compounds. Structure-activity study by molecular simulation

    International Nuclear Information System (INIS)

    Fourcot, Fabrice

    1991-01-01

    The increasing number of industrial applications of rare earths has resulted in an increased demand in purified rare earths whereas their separation is difficult due to their high chemical similarity. The search for a better separation leads to the search for more selective extraction agents. Organophosphorous compounds appear to be the most selective. As the search for new extraction agents resulting in high lanthanide extraction efficiency or in a better selectivity between rare earths has been mainly empiric, this research thesis aims at developing a molecular simulation method which allows the number of molecules to be synthesized and tested to be reduced. After having briefly recalled general knowledge on liquid-liquid extraction and on rare earths, and described calculation methods (quantum methods, methods based on molecular mechanics, conformational analysis, methods of charge calculation), the author proposes a critical review of literature related to rare earth liquid-liquid extraction by organophosphorous acids with respect to the used extraction agent. The molecular modelling issue is then addressed by describing ways to apply it to extraction problems, faced problems, brought solutions and obtained results

  10. Perceived Parental Styles and Adult Separation Anxiety.

    Science.gov (United States)

    Başbuğ, Sezin; Cesur, Gizem; Durak Batıgün, Ayşegül

    2017-01-01

    The Mediating Role of Interpersonal Cognitive Distortions OBJECTIVE: This study primarily aimed to determine whether perceived parental styles and interpersonal cognitive distortions are predictors of adult separation anxiety. Further, this study aimed to examine the mediating role of interpersonal cognitive distortions in the relationship between perceived over-permissive/boundless parental styles and adult separation anxiety in university students. This study included 444 university students (281 female (63,3%) and 163 male (36,7%) with a mean age of sample 21,02 years (SS = 1,70). The Demographic Information Form, Young Parenting Inventory, Interpersonal Cognitive Distortions Scale, and Adult Separation Anxiety Questionnaire were used. The regression analyses revealed that the age of the participants and their percieved controlling/shaping father parenting style negatively predicted adult separation anxiety, while percieved over-permissive/boundless mother parenting style, exploitative/abusive and overprotective/anxious father parenting styles and the subscales of the interpersonal cognitive distortions scale positively predicted adult separation anxiety. As hypothesized, data from this study reveal that subscales of the interpersonal cognitive distortions scale play a full mediating role in the relationship between over-permissive/boundless parenting styles and adult separation anxiety. Results indicate that the perceived over-permissive/boundless parenting style positively predicts adult separation anxiety symptoms by distorting interpersonal cognitions. Furthermore, the over-permissive parenting style and lack of boundaries and/or discipline lead to similar adverse effects as do authoritarian and normative parenting. To our knowledge, there are very few studies investigating adult separation anxiety symptoms in Turkey. Therefore, our current study provides practical information to mental health professionals regarding adult separation anxiety symptoms, which

  11. The separation and recovery of hydrogen from the recycling gas in ammonia production by means of lanthanum-rich mischmetal nickel hydride beds

    International Nuclear Information System (INIS)

    Qidong, W.; Jing, W.; Changpin, C.; Weifang, L.

    1985-01-01

    The separation and recovery of hydrogen by means of a MlNi/sub 5/ (Ml: La-rich mischmetal) beds were studied. The influence of the impurity gas components (O/sub 2/, H/sub 2/O, N/sub 2/, Ar, CH/sub 4/ and NH/sub 3/ etc) on the hydrogen absorption capacity, hydriding and dehydriding kinetics and cycling ageing stability of the beds was investigated for both stagnant gases and continuously flowing gas streams. In small reactors, at first artificially made gas mixtures and finally the actual recycling gas from ammonia production were tested. In the presence of trace ammonia (<100ppm) in recycling gas stream, the efficiency of recovery amounted to 85 - 93% and the purity of the product hydrogen was around 99.9%. When ammonia amounted to 2.5%, the efficiency of recovery decreased to 81 - 86%. The hydrogen absorption capacity of the alloy bed remained unchanged after cycling 50 times, indicating the stability of the alloy satisfactory

  12. INS gas-filled recoil isotope separator

    International Nuclear Information System (INIS)

    Miyatake, M.; Nomura, T.; Kawakami, H.

    1986-09-01

    The characteristics and performance of a small sized gas-filled recoil isotope separator recently made at INS are described. The total efficiency and the ΔBρ/Bρ values have been measured using low velocity 16 O, 40 Ar and 68 As ions and found to be 10 and 5 %, respectively. The Z-dependence of the mean charge is discussed. (author)

  13. Relations between psychological separation and adaptation of adolescents

    Directory of Open Access Journals (Sweden)

    Vukelić Marija

    2006-01-01

    Full Text Available The object of this research is a problem of relations between psychological separation-individuation as well as adaptation to secondary and boarding school and differences in separation and adaptation. Explorative research was performed on the sample of 586 adolescents aged 14-16. The instruments used were: The Psychological Separation Inventory (PSI, Hoffman, 1984, and The Student Adaptation to College Questionnaire (SACQ, Baker & Siryk, 1984. The results showed that adolescents from boarding schools, comparing to those who are not separated from parents during secondary school, have significant higher level of separation of both parents, but discriminate analysis showed that adolescents from boarding schools express nostalgia for their parents and wants more contacts and support from them. Adolescent from boarding school showed general better adaptation, but lower emotional adaptation comparing to not separate adolescents. Discriminate analysis showed that adolescents from boarding schools express low satisfaction with life in boarding school. The results confirm hypothesis of connection between psychological separation from parents and adaptation in adolescence. Canonical correlation analysis showed two statistically significant canonical factors. First factor shows significant connection of lower independence and better adaptation, with 23% explained variance. Second factor indicates connection of lower functional, emotional and attitude independence and better adaptation, with 12% of explained variance. Results are argued in light of theory separation-individuation and importance of meaning of separation from their parents for adolescents for adaptation on request for adaptation on secondary school and boarding school.

  14. The global kernel k-means algorithm for clustering in feature space.

    Science.gov (United States)

    Tzortzis, Grigorios F; Likas, Aristidis C

    2009-07-01

    Kernel k-means is an extension of the standard k -means clustering algorithm that identifies nonlinearly separable clusters. In order to overcome the cluster initialization problem associated with this method, we propose the global kernel k-means algorithm, a deterministic and incremental approach to kernel-based clustering. Our method adds one cluster at each stage, through a global search procedure consisting of several executions of kernel k-means from suitable initializations. This algorithm does not depend on cluster initialization, identifies nonlinearly separable clusters, and, due to its incremental nature and search procedure, locates near-optimal solutions avoiding poor local minima. Furthermore, two modifications are developed to reduce the computational cost that do not significantly affect the solution quality. The proposed methods are extended to handle weighted data points, which enables their application to graph partitioning. We experiment with several data sets and the proposed approach compares favorably to kernel k -means with random restarts.

  15. Method to separate isotopes

    International Nuclear Information System (INIS)

    Coenen, H.; Neuschuetz, D.

    1980-01-01

    An extraction by means of supercritical pure gases (e.g. CD 2 ) or gas mixtures is proposed to separate isotopes, especially H/D, Li-6/Li-7, and U-235/U-238, and water or benzol is used as entrainer. The extraction shall be carried out at pressure rates of about 350 bar above the critical pressure with the temperature being by up to 100 0 C above the critical temperature. A NaCl-solution and the change of the isotopic ratio Cl-35/Cl-37 are investigated for example purpose. (UWI) [de

  16. Affordance of Braille Music as a Mediational Means: Significance and Limitations

    Science.gov (United States)

    Park, Hyu-Yong; Kim, Mi-Jung

    2014-01-01

    Affordance refers to the properties or designs of a thing that offer the function of the thing. This paper discusses the affordance of Braille music in terms of three notions: mediational means, mastery and appropriation, and focuses on answering the following three questions: (i) How do musicians with visual impairments (MVI) perceive Braille…

  17. Identification of column edges of DNA fragments by using K-means clustering and mean algorithm on lane histograms of DNA agarose gel electrophoresis images

    Science.gov (United States)

    Turan, Muhammed K.; Sehirli, Eftal; Elen, Abdullah; Karas, Ismail R.

    2015-07-01

    Gel electrophoresis (GE) is one of the most used method to separate DNA, RNA, protein molecules according to size, weight and quantity parameters in many areas such as genetics, molecular biology, biochemistry, microbiology. The main way to separate each molecule is to find borders of each molecule fragment. This paper presents a software application that show columns edges of DNA fragments in 3 steps. In the first step the application obtains lane histograms of agarose gel electrophoresis images by doing projection based on x-axis. In the second step, it utilizes k-means clustering algorithm to classify point values of lane histogram such as left side values, right side values and undesired values. In the third step, column edges of DNA fragments is shown by using mean algorithm and mathematical processes to separate DNA fragments from the background in a fully automated way. In addition to this, the application presents locations of DNA fragments and how many DNA fragments exist on images captured by a scientific camera.

  18. An analytical model for droplet separation in vane separators and measurements of grade efficiency and pressure drop

    International Nuclear Information System (INIS)

    Koopman, Hans K.; Köksoy, Çağatay; Ertunç, Özgür; Lienhart, Hermann; Hedwig, Heinz; Delgado, Antonio

    2014-01-01

    Highlights: • An analytical model for efficiency is extended with additional geometrical features. • A simplified and a novel vane separator design are investigated experimentally. • Experimental results are significantly affected by re-entrainment effects. • Outlet droplet size spectra are accurately predicted by the model. • The improved grade efficiency doubles the pressure drop. - Abstract: This study investigates the predictive power of analytical models for the droplet separation efficiency of vane separators and compares experimental results of two different vane separator geometries. The ability to predict the separation efficiency of vane separators simplifies their design process, especially when analytical research allows the identification of the most important physical and geometrical parameters and can quantify their contribution. In this paper, an extension of a classical analytical model for separation efficiency is proposed that accounts for the contributions provided by straight wall sections. The extension of the analytical model is benchmarked against experiments performed by Leber (2003) on a single stage straight vane separator. The model is in very reasonable agreement with the experimental values. Results from the analytical model are also compared with experiments performed on a vane separator of simplified geometry (VS-1). The experimental separation efficiencies, computed from the measured liquid mass balances, are significantly below the model predictions, which lie arbitrarily close to unity. This difference is attributed to re-entrainment through film detachment from the last stage of the vane separators. After adjustment for re-entrainment effects, by applying a cut-off filter to the outlet droplet size spectra, the experimental and theoretical outlet Sauter mean diameters show very good agreement. A novel vane separator geometry of patented design (VS-2) is also investigated, comparing experimental results with VS-1

  19. Analysis of CO{sub 2} separation by means of monoethanolamine wash as an option for reducing the emissions in Germany; Analyse der CO{sub 2}-Abtrennung mittels Monoethanolamin-Waesche als Emissionsminderungsmassnahme in Deutschland

    Energy Technology Data Exchange (ETDEWEB)

    Nazarko, Jewgeni; Riensche, Ernst; Blum, Ludger; Menzer, Reinhard; Stolten, Detlef [Forschungszentrum Juelich GmbH, Juelich (DE). Inst. fuer Energieforschung - Brennstoffzellen (IEF-3)

    2008-07-01

    In the year 2006, the utilization of fossil fuels in the power economy in Germany results in CO{sub 2} emissions of 366 million tons. This corresponds to 43.4 % of the entire CO{sub 2} emissions in Germany. In order to reduce the emissions of carbon dioxide at fossil-fuelled power stations significantly, short term retrofits of the plants are to be considered for the separation and storage of CO{sub 2}. From the perspective of the power production, the downstream absorption of CO{sub 2} with monoethanolamine has several advantages: (a) Successful employment of the amine-wash in other industrial's applications; (b) Conventional operation of the power station qualitatively remains unchanged; (c) The downstream separation is the only option for the separation of CO{sub 2} at existing power stations. However, the separation of carbon dioxide results in further material flows and energy flows by means of the absorption in monoethanolamine. In the contribution under consideration, the authors analyze the effects of the absorption of CO{sub 2} in mono ethanol amine on an individual power station as well as on the emissions of the power economy in Germany.

  20. Active Control of Flow Separation Over an Airfoil

    Science.gov (United States)

    Ravindran, S. S.

    1999-01-01

    Designing an aircraft without conventional control surfaces is of interest to aerospace community. In this direction, smart actuator devices such as synthetic jets have been proposed to provide aircraft maneuverability instead of control surfaces. In this article, a numerical study is performed to investigate the effects of unsteady suction and blowing on airfoils. The unsteady suction and blowing is introduced at the leading edge of the airfoil in the form of tangential jet. Numerical solutions are obtained using Reynolds-Averaged viscous compressible Navier-Stokes equations. Unsteady suction and blowing is investigated as a means of separation control to obtain lift on airfoils. The effect of blowing coefficients on lift and drag is investigated. The numerical simulations are compared with experiments from the Tel-Aviv University (TAU). These results indicate that unsteady suction and blowing can be used as a means of separation control to generate lift on airfoils.

  1. Obstacle mean-field game problem

    KAUST Repository

    Gomes, Diogo A.; Patrizi, Stefania

    2015-01-01

    In this paper, we introduce and study a first-order mean-field game obstacle problem. We examine the case of local dependence on the measure under assumptions that include both the logarithmic case and power-like nonlinearities. Since the obstacle operator is not differentiable, the equations for first-order mean field game problems have to be discussed carefully. Hence, we begin by considering a penalized problem. We prove this problem admits a unique solution satisfying uniform bounds. These bounds serve to pass to the limit in the penalized problem and to characterize the limiting equations. Finally, we prove uniqueness of solutions. © European Mathematical Society 2015.

  2. Optimization of the isotope separation in columns

    International Nuclear Information System (INIS)

    Kaminskij, V.A.; Vetsko, V.M.; Tevzadze, G.A.; Devdariani, O.A.; Sulaberidze, G.A.

    1982-01-01

    The general method for the multi-parameter optimization of cascade plants of packed columns is proposed. As an optimization effectiveness function a netcost of the isotopic product is selected. The net cost is comprehensively characterizing the sum total of capital costs for manufacturing the products as well as determining the choice of the most effective directions for capital investments and rational limits of improvement of the products quality. The method is based on main representations of the cascade theory, such as the ideal flow profile and form efficiency as well as mathematical model of the packed column specifying the bonds between its geometric and operating parameters. As a result, the isotopic products cost function could be bound with such parameters as the equilibrium stage height, ultimate packing capacity, its element dimensions, column diameter. It is concluded that the suggested approach to the optimization of isotope separation processes is rather a general one. It permits to solve a number of special problems, such as estimation of advisability of using heat-pump circuits and determining the rational automation level. Besides, by means of the method suggested one can optimize the process conditions with regard to temperature and pressure

  3. A simple transferable adaptive potential to study phase separation in large-scale xMgO-(1-x)SiO2 binary glasses.

    Science.gov (United States)

    Bidault, Xavier; Chaussedent, Stéphane; Blanc, Wilfried

    2015-10-21

    A simple transferable adaptive model is developed and it allows for the first time to simulate by molecular dynamics the separation of large phases in the MgO-SiO2 binary system, as experimentally observed and as predicted by the phase diagram, meaning that separated phases have various compositions. This is a real improvement over fixed-charge models, which are often limited to an interpretation involving the formation of pure clusters, or involving the modified random network model. Our adaptive model, efficient to reproduce known crystalline and glassy structures, allows us to track the formation of large amorphous Mg-rich Si-poor nanoparticles in an Mg-poor Si-rich matrix from a 0.1MgO-0.9SiO2 melt.

  4. Performance and separation occurrence of binary probit regression estimator using maximum likelihood method and Firths approach under different sample size

    Science.gov (United States)

    Lusiana, Evellin Dewi

    2017-12-01

    The parameters of binary probit regression model are commonly estimated by using Maximum Likelihood Estimation (MLE) method. However, MLE method has limitation if the binary data contains separation. Separation is the condition where there are one or several independent variables that exactly grouped the categories in binary response. It will result the estimators of MLE method become non-convergent, so that they cannot be used in modeling. One of the effort to resolve the separation is using Firths approach instead. This research has two aims. First, to identify the chance of separation occurrence in binary probit regression model between MLE method and Firths approach. Second, to compare the performance of binary probit regression model estimator that obtained by MLE method and Firths approach using RMSE criteria. Those are performed using simulation method and under different sample size. The results showed that the chance of separation occurrence in MLE method for small sample size is higher than Firths approach. On the other hand, for larger sample size, the probability decreased and relatively identic between MLE method and Firths approach. Meanwhile, Firths estimators have smaller RMSE than MLEs especially for smaller sample sizes. But for larger sample sizes, the RMSEs are not much different. It means that Firths estimators outperformed MLE estimator.

  5. SWINE MANURE SOLIDS SEPARATION AND THERMOCHEMICAL CONVERSION TO HEAVY OIL

    Directory of Open Access Journals (Sweden)

    Shuangning Xiu

    2009-05-01

    Full Text Available Separation of solids from liquid swine manure and subsequent thermo-chemical conversion (TCC of the solids fraction into oil is one way of reducing the waste strength and odor emission. Such processing also provides a potential means of producing renewable energy from animal wastes. Gravity settling and mechanical separation techniques, by means of a centrifuge and belt press, were used to remove the solids from liquid swine manure. The solid fractions from the above separation processes were used as the feedstock for the TCC process for oil production. Experiments were conducted in a batch reactor with a steady temperature 305 oC, and the corresponding pressure was 10.34 Mpa. Gravity settling was demonstrated to be capable of increasing the total solids content of manure from 1% to 9%. Both of the mechanical separation systems were able to produce solids with dry matter around 18% for manure, with 1% to 2% initial total solids. A significant amount of volatile solid (75.7% was also obtained from the liquid fraction using the belt press process. The oil yields of shallow pit manure solids and deep pit manure solids with belt press separation were 28.72% and 29.8% of the total volatile solids, respectively. There was no visible oil product obtained from the deep pit manure solids with centrifuge separation. It is believed that it is the volatile solid content and the other components in the manure chemical composition which mainly deter-mine the oil production.

  6. Preconcentration and Separation of Mixed-Species Samples Near a Nano-Junction in a Convergent Microchannel

    Directory of Open Access Journals (Sweden)

    Ping-Hsien Chiu

    2015-12-01

    Full Text Available A fluidic microchip incorporating a convergent microchannel and a Nafion-nanoporous membrane is proposed for the preconcentration and separation of multi-species samples on a single platform. In the device, sample preconcentration is achieved by means of the ion concentration polarization effect induced at the micro/nano interface under the application of an external electric field, while species separation is achieved by exploiting the different electrophoretic mobilities of the sample components. The experimental results show that the device is capable of detecting C-reactive protein (CRP with an initial concentration as low as 9.50 × 10−6 mg/L given a sufficient preconcentration time and driving voltage. In addition, it is shown that a mixed-species sample consisting of three negatively-charged components (bovine serum albumin (BSA, tetramethylrhodamine(TAMRA isothiocyanate-Dextran and fluorescent polymer beads can be separated and preconcentrated within 20 min given a driving voltage of 100 V across 1 cm microchannel in length. In general, the present results confirm the feasibility of the device for the immunoassay or detection of various multi-species samples under low concentration in the biochemical and biomedical fields. The novel device can therefore improve the detection limit of traditional medical facilities.

  7. Separation of actinides and their transmutation

    International Nuclear Information System (INIS)

    Bouchard, M.; Bathelier, M.; Cousin, M.

    1978-08-01

    Neutron irradiation of long-half-life actinides for transmutation into elements with shorter half-life is investigated as a means to reduce the long-term hazards of these actinides. The effectiveness of the method is analysed by applying it to fission product solutions from the first extraction cycle of fuel reprocessing plants. Basic principles, separation techniques and transmutation efficiencies are studied and discussed in detail

  8. Equation of state of isospin-asymmetric nuclear matter in relativistic mean-field models with chiral limits

    International Nuclear Information System (INIS)

    Jiang Weizhou; Li Baozn; Chen Liewen

    2007-01-01

    Using in-medium hadron properties according to the Brown-Rho scaling due to the chiral symmetry restoration at high densities and considering naturalness of the coupling constants, we have newly constructed several relativistic mean-field Lagrangians with chiral limits. The model parameters are adjusted such that the symmetric part of the resulting equation of state at supra-normal densities is consistent with that required by the collective flow data from high energy heavy-ion reactions, while the resulting density dependence of the symmetry energy at sub-saturation densities agrees with that extracted from the recent isospin diffusion data from intermediate energy heavy-ion reactions. The resulting equations of state have the special feature of being soft at intermediate densities but stiff at high densities naturally. With these constrained equations of state, it is found that the radius of a 1.4M o canonical neutron star is in the range of 11.9 km≤R≤13.1 km, and the maximum neutron star mass is around 2.0M o close to the recent observations

  9. Separation Of N-Nitrosamines By Micellar Electrokinetic Chromatography

    International Nuclear Information System (INIS)

    Nur Amira Md Ali; Mohd Marsin Sanagi; Wan Aini Wan Ibrahim

    2014-01-01

    A simple and rapid micellar electrokinetic chromatography (MEKC) method was developed for separation of three selected N-Nitrosamines namely N-nitrosodipropylamine (NDPA), N-nitrosodibutylamine (NDBA) and N-nitrosodiphenylamine (NDPhA). The effects of composition of the buffer and its pH, concentration of surfactants on the separation and migration times of nitrosamines were investigated. The instrumental variables affecting sensitivity and resolution such as power supply and injection mode were carefully optimized. The best separation was achieved using 40 mM sodium dodecyl sulfate (SDS) as a surfactant in 10 mM phosphate buffer (pH 8.0) at a temperature of 25 degree Celsius, applied voltage of 29 kV, wavelength of 230 nm and electrokinetic injection of 9 s at 5 kV within 10 min analysis time. Excellent linearity was obtained in the concentration range of 2 to 100 μg/ mL with coefficients of determination, r 2 ≥0.979. This method showed good reproducibility with relative standard deviation (RSDs) value ranging from 2.46 % to 6.61 %. The limits of detection (LOD) and limits of quantification (LOQ) ranged from 0.16 to 0.43 μg/ mL and 0.54 to 1.44 μg/mL respectively. (author)

  10. Emotional Separation and Detachment as Two Distinct Dimensions of Parent-Adolescent Relationships

    Science.gov (United States)

    Ingoglia, Sonia; Lo Coco, Alida; Liga, Francesca; Lo Cricchio, Maria Grazia

    2011-01-01

    The study examined adolescents' emotional separation and detachment from parents, analyzing their relations with connectedness and agency, with some aspects of self-other boundary regulation and with problem behavior. The participants were 331 Italian adolescents, aged from 16 to 19 years (mean age = 17.40, SD = 1.14). Separation and detachment…

  11. Parental Separation, Parental Alcoholism, and Timing of First Sexual Intercourse

    Science.gov (United States)

    Waldron, Mary; Doran, Kelly A.; Bucholz, Kathleen K.; Duncan, Alexis E.; Lynskey, Michael T.; Madden, Pamela A. F.; Sartor, Carolyn E.; Heath, Andrew C.

    2015-01-01

    Purpose We examined timing of first voluntary sexual intercourse as a joint function of parental separation during childhood and parental history of alcoholism. Methods Data were drawn from a birth cohort of female like-sex twins (n=569 African Ancestry [AA], n=3415 European or other Ancestry [EA]). Cox proportional hazards regression was conducted predicting age at first sex from dummy variables coding for parental separation and parental alcoholism. Propensity score analysis was also employed comparing intact and separated families, stratified by predicted probability of separation. Results Earlier sex was reported by EA twins from separated and alcoholic families, compared to EA twins from intact nonalcoholic families, with effects most pronounced through age 14. Among AA twins, effects of parental separation and parental alcoholism were largely nonsignificant. Results of propensity score analyses confirmed unique risks from parental separation in EA families, where consistent effects of parental separation were observed across predicted probability of separation. For AA families there was poor matching on risk-factors presumed to predate separation, which limited interpretability of survival-analytic findings. Conclusions In European American families, parental separation during childhood is an important predictor of early-onset sex, beyond parental alcoholism and other correlated risk-factors. To characterize risk for African Americans associated with parental separation, additional research is needed where matching on confounders can be achieved. PMID:25907653

  12. Separation of mixed waste plastics via magnetic levitation.

    Science.gov (United States)

    Zhao, Peng; Xie, Jun; Gu, Fu; Sharmin, Nusrat; Hall, Philip; Fu, Jianzhong

    2018-06-01

    Separation becomes a bottleneck of dealing with the enormous stream of waste plastics, as most of the extant methods can only handle binary mixtures. In this paper, a novel method that based on magnetic levitation was proposed for separating multiple mixed plastics. Six types of plastics, i.e., polypropylene (PP), acrylonitrile butadiene styrene (ABS), polyamide 6 (PA6), polycarbonate (PC), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE), were used to simulate the mixed waste plastics. The samples were mixed and immersed into paramagnetic medium that placed into a magnetic levitation configuration with two identical NdFeB magnets with like-poles facing each other, and Fourier transform infrared (FTIR) spectroscopy was employed to verify the separation outputs. Unlike any conventional separation methods such as froth flotation and hydrocyclone, this method is not limited by particle sizes, as mixtures of different size fractions reached their respective equilibrium positions in the initial tests. The two-stage separation tests demonstrated that the plastics can be completely separated with purities reached 100%. The method has the potential to be industrialised into an economically-viable and environmentally-friendly mass production procedure, since quantitative correlations are determined, and the paramagnetic medium can be reused indefinitely. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Isotope separation by photoselective dissociative electron

    International Nuclear Information System (INIS)

    Stevens, C.G.

    1978-01-01

    A method of separating isotopes based on photoselective electron capture dissociation of molecules having an electron capture cross section dependence on the vibrational state of the molecule is described. A molecular isotope source material is irradiated to selectively excite those molecules containing a desired isotope to a predetermined vibrational state having associated therewith an electron capture energy region substantially non-overlapping with the electron capture energy ranges associated with the lowest vibration states of the molecules. The isotope source is also subjected to electrons having an energy corresponding to the non-overlapping electron capture region whereby the selectively excited molecules preferentially capture electrons and dissociate into negative ions and neutrals. The desired isotope may be in the negative ion product or in the neutral product depending upon the mechanism of dissociation of the particular isotope source used. The dissociation product enriched in the desired isotope is then separated from the reaction system by conventional means. Specifically, 235 UF 6 is separated from a UF 6 mixture by selective excitation followed by dissociative electron capture into 235 UF 5 - and F

  14. Separation of Transfer Ribonucleic Acids by Reverse Phase Chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Kelmers, A. D.; Novelli, G. David; Stulberg, M. P.

    1965-10-01

    Numerous experimental techniques for the separation of transfer ribonucleic acids have been successful in preparing partially purified fractions of several specific t-RNAs. Many of the existing methods have depended upon the differential solubility of specific t-RNAs in complex two-phase systems (1-6) and the separation was achieved by means of counter-current extraction techniques. Column chromatography experiments using cellulose exchangers, (7,8) methylated albumin (9,10) or with solvent phases supported on inert material (11-13) have also shown partial separation of specific t-RNAs. Paper chromatographic procedures have produced partial resolutions of t-RNA.14 Methods involving chemical treatment of specific t-RNAs have been reported (15-19).

  15. Separation of mixtures of organic substance using reverse osmosis membranes

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, Shoji; Nakao, Shin' ichi; Tanimura, Shinobu

    1987-12-25

    With the arrival of energy crisis, attention has been concentrated on the production of alcohol by means of biomass conversion. Energy-saving concentration method was searched to replace a distillation method as a method of concentrating dilute alcohols, for which a reverse osmosis method was proposed; experimental results have been reported accordingly. One result is that the osmotic pressure method has a limitation of difficulty to exceed more than 15% concentration. For this, the reverse osmosis was reviewed and it was found that wider concentration range should be examined for the area where the reverse osmosis was not experimented. Fils employed were a polyamide film of Nitto Denko Co. and an acrylonitrile film of sumitomo Chemical Co.. The result revealed that alcohol could be concentrated up to rather high concentration in alcohol-water system; even in a non-aqueous system, separation with high selective permeability was possible by the proper selection of film materials. (4 figs, 2 refs)

  16. Method for enriching and separating heavy hydrogen isotopes from substance streams containing such isotopes by means of isotope exchange

    International Nuclear Information System (INIS)

    Knochel, A.; Eggers, I.; Klatte, B.; Wilken, R. D.

    1985-01-01

    A process for enriching and separating heavy hydrogen isotopes having a heavy hydrogen cation (deuterium and/or tritium) from substance streams containing them, wherein the respectively present hydrogen isotopes are exchanged in chemical equilibria. A protic, acid solution containing deuterium and/or tritium is brought into contact with a value material from the group of open-chained polyethers or aminopolyethers, macro-monocyclic or macro-polycyclic polyethers, macro-monocyclic or macro-polycyclic amino polyethers, and mixtures of these values, in their free or proton salt form to form a reaction product of the heavy hydrogen cation with the value or value salt and bring about enrichment of deuterium and/or tritium in the reaction product. The reaction product containing the value or value salt is separated from the solution. The separated reaction product is treated to release the hydrogen isotope(s) to be enriched in the form of deuterium oxide (HDO) and/or tritium oxide (HTO) by regenerating the value or its salt, respectively. The regenerated value is returned for reuse

  17. Study on decay of 118Xe and 119Xe by means of mass-separator on-line with a synchrocyclotron

    International Nuclear Information System (INIS)

    Berlovich, Eh.E.; Batist, L.Kh.; Blinnikov, Yu.S.

    1976-01-01

    The decay of sup(118, 119)Xe isotopes has been investigated. An experimental device involving a mass-separator operating in line with a synchrocyclotron is briefly outlined. The elements to be investigated were isolated from a proton-irradiated target by the 'on-beam-chemistry' methods and transferred into the mass-separator ion source. The Xe separated ions are transported to detectors in an experimental ha ll. The energies and relative γ ray intensities of 118 Xe → 118 J and of 119 Xe → 119 J decays ar presented. The error of the γ ray energy determination does not exceed 0.6 keV. Obtained are the periods of half-life: for 118 Xe - (3.8+-0.9) min, for 119 Xe - (5.8+-0.3) min. The decay scheme for 119 Xe is made up. The scheme of 119 Xe levels is well inscribed into the general systematics of the J odd isotope levels. On the basis of obtained and known data the spin values are described to the 119 J levels

  18. Local-Field Distribution of Two Dielectric Inclusions at Small Separation

    Science.gov (United States)

    Siu, Yuet-Lun; Yu, Kin-Wah

    2001-03-01

    When two dielectric inclusions approach to each other in a composite medium, significant mutual polarization effects must occur. These effects are multipolar in nature and are difficult to treat from first principles(J. D. Jackson, Classical Electrodynamics), 2nd edition, (Wiley, New York, 1975).. In this work, we employ the discrete-dipole theory(B. T. Draine and P. J. Flatau, J. Opt. Soc. Am. A 11) 1491 (1994). to account for the mutual polarization effects by dividing the inclusions into many small subparts. We begin the calculation at small inclusion sizes and large separation, where the point-dipole limit being valid, and proceed to larger inclusion sizes and small separation, for which the mutual polarization effect becomes important. Then, we apply the theory to determine the dipole moment of each subpart self-consistently. In this way, each dipole moment yields the local electric field, which in turn polarizes the neighboring dipoles. We also begin the calculation at small inclusion sizes and large separation, where the point-dipole limit being valid, and proceed to larger inclusion sizes and small separation. Our resluts indicate that convergence is achieved with moderate computational effects. The results produce valuable information about the local electric field distribution, which is relevant to optical absorption due to surface phonon-polaritons of ionic microcrystals.

  19. Teaching Simulation and Computer-Aided Separation Optimization in Liquid Chromatography by Means of Illustrative Microsoft Excel Spreadsheets

    Science.gov (United States)

    Fasoula, S.; Nikitas, P.; Pappa-Louisi, A.

    2017-01-01

    A series of Microsoft Excel spreadsheets were developed to simulate the process of separation optimization under isocratic and simple gradient conditions. The optimization procedure is performed in a stepwise fashion using simple macros for an automatic application of this approach. The proposed optimization approach involves modeling of the peak…

  20. Time independent mean-field theory

    International Nuclear Information System (INIS)

    Negele, J.W.

    1980-02-01

    The physical and theoretical motivations for the time-dependent mean-field theory are presented, and the successes and limitations of the time-dependent Hartree-Fock initial-vaue problem are reviewed. New theoretical developments are described in the treatment of two-body correlations and the formulation of a quantum mean-field theory of large-amplitude collective motion and tunneling decay. Finally, the mean-field theory is used to obtain new insights into the phenomenon of pion condensation in finite nuclei. 18 figures

  1. Separation of uranium by biosorption

    International Nuclear Information System (INIS)

    Volesky, B.; Tsezos, M.

    1983-01-01

    This invention relates to metal ion separation processes and more particularly to processes of extraction of specific ions of or containing heavy metals from waste liquids by means of biosorption. The invention is based upon the discovery that the biomass produced as the result of the growth of a certain carefully selected microbial genus, namely species of the genus Rhizopus, such as Rhizopus arihizus, has an outstanding ability for selective adsorption of uranium and thorium ions from aqueous solution or suspension

  2. Liquid chromatographic separation of zalcitabine and its stereoisomers.

    Science.gov (United States)

    Scypinski, S; Ross, A J

    1994-10-01

    A liquid chromatographic method capable of separating and quantitating the stereoisomers of zalcitabine has been developed and validated. The separation was achieved with an Astec Cyclobond I--RSP column and a mobile phase of 0.25% triethylamine in water adjusted to a pH of 6.5 with glacial acetic acid. All enantiomers were found to exhibit a linear response in the range of 0.1-10% in the presence of 100% zalcitabine. Precision of analysis was found to be less than 1.5% at a level of 1% relative to zalcitabine. The limit of detection for two of the three enantiomeric impurities was determined to be 0.05% relative to zalcitabine. The detection limit for the third was found to be 0.1%. This method was successfully applied to the analysis of reference standards and several production scale batches. All of these materials were found to be stereochemically pure to a level of 99.8% or better.

  3. Pilot and Controller Evaluations of Separation Function Allocation in Air Traffic Management

    Science.gov (United States)

    Wing, David; Prevot, Thomas; Morey, Susan; Lewis, Timothy; Martin, Lynne; Johnson, Sally; Cabrall, Christopher; Como, Sean; Homola, Jeffrey; Sheth-Chandra, Manasi; style="text-decoration: none; " href="javascript:void(0); " onClick="displayelement('author_20130014930'); toggleEditAbsImage('author_20130014930_show'); toggleEditAbsImage('author_20130014930_hide'); "> style="display:inline; width:12px; height:12px; " src="images/arrow-up.gif" width="12" height="12" border="0" alt="hide" id="author_20130014930_show"> style="width:12px; height:12px; display:none; " src="images/arrow-down.gif" width="12" height="12" border="0" alt="hide" id="author_20130014930_hide">

    2013-01-01

    Two human-in-the-loop simulation experiments were conducted in coordinated fashion to investigate the allocation of separation assurance functions between ground and air and between humans and automation. The experiments modeled a mixed-operations concept in which aircraft receiving ground-based separation services shared the airspace with aircraft providing their own separation service (i.e., self-separation). Ground-based separation was provided by air traffic controllers without automation tools, with tools, or by ground-based automation with controllers in a managing role. Airborne self-separation was provided by airline pilots using self-separation automation enabled by airborne surveillance technology. The two experiments, one pilot-focused and the other controller-focused, addressed selected key issues of mixed operations, assuming the starting point of current-day operations and modeling an emergence of NextGen technologies and procedures. In the controller-focused experiment, the impact of mixed operations on controller performance was assessed at four stages of NextGen implementation. In the pilot-focused experiment, the limits to which pilots with automation tools could take full responsibility for separation from ground-controlled aircraft were tested. Results indicate that the presence of self-separating aircraft had little impact on the controllers' ability to provide separation services for ground-controlled aircraft. Overall performance was best in the most automated environment in which all aircraft were data communications equipped, ground-based separation was highly automated, and self-separating aircraft had access to trajectory intent information for all aircraft. In this environment, safe, efficient, and highly acceptable operations could be achieved for twice today's peak airspace throughput. In less automated environments, reduced trajectory intent exchange and manual air traffic control limited the safely achievable airspace throughput and

  4. A comparison of likelihood ratio tests and Rao's score test for three separable covariance matrix structures.

    Science.gov (United States)

    Filipiak, Katarzyna; Klein, Daniel; Roy, Anuradha

    2017-01-01

    The problem of testing the separability of a covariance matrix against an unstructured variance-covariance matrix is studied in the context of multivariate repeated measures data using Rao's score test (RST). The RST statistic is developed with the first component of the separable structure as a first-order autoregressive (AR(1)) correlation matrix or an unstructured (UN) covariance matrix under the assumption of multivariate normality. It is shown that the distribution of the RST statistic under the null hypothesis of any separability does not depend on the true values of the mean or the unstructured components of the separable structure. A significant advantage of the RST is that it can be performed for small samples, even smaller than the dimension of the data, where the likelihood ratio test (LRT) cannot be used, and it outperforms the standard LRT in a number of contexts. Monte Carlo simulations are then used to study the comparative behavior of the null distribution of the RST statistic, as well as that of the LRT statistic, in terms of sample size considerations, and for the estimation of the empirical percentiles. Our findings are compared with existing results where the first component of the separable structure is a compound symmetry (CS) correlation matrix. It is also shown by simulations that the empirical null distribution of the RST statistic converges faster than the empirical null distribution of the LRT statistic to the limiting χ 2 distribution. The tests are implemented on a real dataset from medical studies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Separation of uranium isotopes by gas centrifugation

    International Nuclear Information System (INIS)

    Jordan, I.

    1980-05-01

    The uranium isotope enrichment is studied by means of the countercurrent gas centrifuge driven by thermal convection. A description is given of (a) the transfer and purification of the uranium hexafluoride used as process gas in the present investigation; (b) the countercurrent centrifuge ZG3; (c) the system designed for the introduction and extraction of the process gas from the centrifuge; (d) the measurement of the process gas flow rate through the centrifuge; (e) the determination of the uranium isotopic abundance by mass spectrometry; (f) the operation and mechanical behavior of the centrifuge and (g) the isotope separation experiments, performed, respectively, at total reflux and with production of enriched material. The results from the separation experiments at total reflux are discussed in terms of the enrichment factor variation with the magnitude and flow profile of the countercurrent given by the temperature difference between the rotor covers. As far as the separation experiments with production are concerned, the discussion of their results is presented through the variation of the enrichment factor as a function of the flow rate, the observed asymmetry of the process and the calculated separative power of the centrifuge. (Author) [pt

  6. Aeroelastic Limit-Cycle Oscillations resulting from Aerodynamic Non-Linearities

    NARCIS (Netherlands)

    van Rooij, A.C.L.M.

    2017-01-01

    Aerodynamic non-linearities, such as shock waves, boundary layer separation or boundary layer transition, may cause an amplitude limitation of the oscillations induced by the fluid flow around a structure. These aeroelastic limit-cycle oscillations (LCOs) resulting from aerodynamic non-linearities

  7. Separation of 51Cr by Means of the Szilard-Chalmers Effect from Potassium Chromate Irradiated at Low Temperature

    International Nuclear Information System (INIS)

    Brune, D.

    1967-08-01

    The recombination of 51 Cr in K 2 CrO 4 at low temperature as well as under dilute conditions has been investigated. Crystals of K 2 CrO 4 and a 1 % solution of this compound have been irradiated in a thermal column of a nuclear reactor. Lowering of the temperature was observed to cause a decrease in retention. Chemical separations have been carried out both at 0 C and at 20 deg C. The degree of enrichment was determined by reactivating one part of the solution after separation of the hexavalent chromium. Irradiation of K 2 CrO 4 in the frozen aqueous solution was observed to favour the degree of enrichment. The fate of the 51 Cr recoil nuclide has been discussed in the light of the thermal spike theory

  8. Mise en oeuvre et etalonnage d'une soufflerie de recherche sur les couches limites

    Science.gov (United States)

    Pioton, Julien

    In order to reproduce a turbulent boundary layer separation bubble in a laboratory at the École de Technologie Supérieure of Montreal, an open-circuit wind tunnel equipped with a blow-down centrifugal fan has been implemented and calibrated for this research project. The methodology for the conception of the wind tunnel components, based on the results obtained from previous experiments, has been validated by the comparison between experimental and theoretical pressure losses along the wind tunnel. Dimensionless mean axial velocity measurements in the working section have showed an irrotational uniform flow zone at the contraction end, which demonstrates the satisfactory performance of the flowconditioning components located upstream from the working section. Mean axial velocity and total pressure measurements along the working section have allowed for estimates of the location of boundary between irrotational and rotational flow at the separation bubble. The maximum mean height of the boundary layer has been estimated at around 15 cm. Oil film visualisations have revealed a mean bubble separation length of approximately 52 cm. Theses oil visualisations, supported by mean lateral velocity measurements in the current configuration of the working section, have indicated important three-dimensional effects and significant dissymmetry in the vicinity of the separation and reattachment zones at the separation bubble.

  9. New, rapid method for the separation of labelled sterols synthesized by cell cultures by means of Extrelut

    International Nuclear Information System (INIS)

    Pill, J.; Johne, G.; Stegmeier, K.; Frey, A.; Frey, B.; Schmidt, F.H.

    1985-01-01

    The experiments have shown, that the use of Extrelut is a successful and simple way to separate labelled CH from biological materials. The doing without an internal standard leads to a reduction in consumption of radioactive material. The procedure is time and solvent saving and appropriate for a large number of samples. (orig.)

  10. Noble gas separation methods for radioactivity retention in nuclear facilities

    International Nuclear Information System (INIS)

    Lehmer, W.; Schiller, H.

    1976-01-01

    The possibilities of applying process techniques in order to reduce gas-borne activity by means of different gas separation processes are looked at and their effectiveness are critically compared. (HP/LN) [de

  11. A Theory of Material Spike Formation in Flow Separation

    Science.gov (United States)

    Serra, Mattia; Haller, George

    2017-11-01

    We develop a frame-invariant theory of material spike formation during flow separation over a no-slip boundary in two-dimensional flows with arbitrary time dependence. This theory identifies both fixed and moving separation, is effective also over short-time intervals, and admits a rigorous instantaneous limit. Our theory is based on topological properties of material lines, combining objectively stretching- and rotation-based kinematic quantities. The separation profile identified here serves as the theoretical backbone for the material spike from its birth to its fully developed shape, and remains hidden to existing approaches. Finally, our theory can be used to rigorously explain the perception of off-wall separation in unsteady flows, and more importantly, provide the conditions under which such a perception is justified. We illustrate our results in several examples including steady, time-periodic and unsteady analytic velocity fields with flat and curved boundaries, and an experimental dataset.

  12. Observational evidence of seasonality in the timing of loop current eddy separation

    Science.gov (United States)

    Hall, Cody A.; Leben, Robert R.

    2016-12-01

    Observational datasets, reports and analyses over the time period from 1978 through 1992 are reviewed to derive pre-altimetry Loop Current (LC) eddy separation dates. The reanalysis identified 20 separation events in the 15-year record. Separation dates are estimated to be accurate to approximately ± 1.5 months and sufficient to detect statistically significant LC eddy separation seasonality, which was not the case for previously published records because of the misidentification of separation events and their timing. The reanalysis indicates that previously reported LC eddy separation dates, determined for the time period before the advent of continuous altimetric monitoring in the early 1990s, are inaccurate because of extensive reliance on satellite sea surface temperature (SST) imagery. Automated LC tracking techniques are used to derive LC eddy separation dates in three different altimetry-based sea surface height (SSH) datasets over the time period from 1993 through 2012. A total of 28-30 LC eddy separation events were identified in the 20-year record. Variations in the number and dates of eddy separation events are attributed to the different mean sea surfaces and objective-analysis smoothing procedures used to produce the SSH datasets. Significance tests on various altimetry and pre-altimetry/altimetry combined date lists consistently show that the seasonal distribution of separation events is not uniform at the 95% confidence level. Randomization tests further show that the seasonal peak in LC eddy separation events in August and September is highly unlikely to have occurred by chance. The other seasonal peak in February and March is less significant, but possibly indicates two seasons of enhanced probability of eddy separation centered near the spring and fall equinoxes. This is further quantified by objectively dividing the seasonal distribution into two seasons using circular statistical techniques and a k-means clustering algorithm. The estimated

  13. Separation and electrodeposited of 210 Po

    International Nuclear Information System (INIS)

    Ordonez R, E.; Iturbe G, J.L.

    1991-12-01

    Presently work it was determined the selective separation of the 210 Po that is in an uraniferous mineral, by means of acid leaching of the mineral and the purification was carried out by means of partition chromatography whose stationary phase is 2-ethylhexyl phosphoric acid (D 2 EHPA), it has been possible to isolate the 210 Po of the rest of the radioactive elements that conform the family 4 N +2 , the optimal elutriation conditions of this element were settled down of manner of not dragging other radioelements. Another of the achievements presented in this communication has been the electrodeposition of this element has more than enough stainless steel discs with a superior yield to 95%. (Author)

  14. On recent developments in marginal separation theory.

    Science.gov (United States)

    Braun, S; Scheichl, S

    2014-07-28

    Thin aerofoils are prone to localized flow separation at their leading edge if subjected to moderate angles of attack α. Although 'laminar separation bubbles' at first do not significantly alter the aerofoil performance, they tend to 'burst' if α is increased further or if perturbations acting upon the flow reach a certain intensity. This then either leads to global flow separation (stall) or triggers the laminar-turbulent transition process within the boundary layer flow. This paper addresses the asymptotic analysis of the early stages of the latter phenomenon in the limit as the characteristic Reynolds number [Formula: see text], commonly referred to as marginal separation theory. A new approach based on the adjoint operator method is presented that enables the fundamental similarity laws of marginal separation theory to be derived and the analysis to be extended to higher order. Special emphasis is placed on the breakdown of the flow description, i.e. the formation of finite-time singularities (a manifestation of the bursting process), and on its resolution being based on asymptotic arguments. The passage to the subsequent triple-deck stage is described in detail, which is a prerequisite for carrying out a future numerical treatment of this stage in a proper way. Moreover, a composite asymptotic model is developed in order for the inherent ill-posedness of the Cauchy problems associated with the current flow description to be resolved.

  15. Parental separation, parental alcoholism, and timing of first sexual intercourse.

    Science.gov (United States)

    Waldron, Mary; Doran, Kelly A; Bucholz, Kathleen K; Duncan, Alexis E; Lynskey, Michael T; Madden, Pamela A F; Sartor, Carolyn E; Heath, Andrew C

    2015-05-01

    We examined timing of first voluntary sexual intercourse as a joint function of parental separation during childhood and parental history of alcoholism. Data were drawn from a birth cohort of female like-sex twins (n = 569 African ancestry [AA]; n = 3,415 European or other ancestry [EA]). Cox proportional hazards regression was conducted predicting age at first sex from dummy variables coding for parental separation and parental alcoholism. Propensity score analysis was also employed to compare intact and separated families, stratified by predicted probability of separation. Earlier sex was reported by EA twins from separated and alcoholic families, compared to EA twins from intact nonalcoholic families, with effects most pronounced through the age of 14 years. Among AA twins, effects of parental separation and parental alcoholism were largely nonsignificant. Results of propensity score analyses confirmed unique risks from parental separation in EA families, where consistent effects of parental separation were observed across predicted probability of separation. For AA families, there was poor matching on risk factors presumed to predate separation, which limited interpretability of survival-analytic findings. In European American families, parental separation during childhood is an important predictor of early-onset sex, beyond parental alcoholism and other correlated risk factors. To characterize risk for African Americans associated with parental separation, additional research is needed where matching on confounders can be achieved. Copyright © 2015 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  16. Rapid determination of environmental plutonium in large water samples by means of manganese dioxide Co-precipitation and extraction chromatographic separation

    International Nuclear Information System (INIS)

    Sidhu, R.S.; Hoff, P.

    1999-01-01

    Plutonium activity determinations in environmental water samples are routinely performed in many laboratories. Due to the low plutonium concentrations and the complexity of the plutonium aqueous chemistry, these analysis involve cumbersome preconcentration and separation procedures and long measurement times. We describe a procedure where MnO 2 (s) is used as scavenger to preconcentrate Pu prior to separation by the transuranium specific extraction chromatographic resin TRU-Resin. The ability of MnO 4 - /MnO 2 (s) to destroy organic matter and oxidise plutonium is combined with the specific behaviour of the TRU-resin for transuranium elements. The method facilitates a rapid preconcentration and separation of plutonium. With the use of this procedure, the laboratory work on one sample can be performed in one day with minimum attention. The overall yields from a 200 litre fresh- or seawater sample to a measurable Pu source are between 70-85%. (orig.)

  17. Limit lines for risk

    International Nuclear Information System (INIS)

    Cox, D.C.; Baybutt, P.

    1982-01-01

    Approaches to the regulation of risk from technological systems, such as nuclear power plants or chemical process plants, in which potential accidents may result in a broad range of adverse consequences must take into account several different aspects of risk. These include overall or average risk, accidents posing high relative risks, the rate at which accident probability decreases with increasing accident consequences, and the impact of high frequency, low consequence accidents. A hypothetical complementary cumulative distribution function (CCDF), with appropriately chosen parametric form, meets all these requirements. The Farmer limit line, by contrast, places limits on the risks due to individual accident sequences, and cannot adequately account for overall risk. This reduces its usefulness as a regulatory tool. In practice, the CCDF is used in the Canadian nuclear licensing process, while the Farmer limit line approach, supplemented by separate qualitative limits on overall risk, is employed in the United Kingdom

  18. Liquid membranes: an emerging area in separation science

    International Nuclear Information System (INIS)

    Mohapatra, P.K.; Manchanda, V.K.

    2010-01-01

    Full text: With the ever increasing energy demands, nuclear energy is poised to make a significant contribution as one of the major clean energy resources. The public acceptability of the nuclear energy programme, however, depends largely on the management of radioactive waste by mitigating its long term adverse impact on the environment. Separation of long-lived radionuclides such as actinides and fission products from high level radioactive waste is a challenging task for the chemists involved at the back end of the nuclear fuel cycle. Amongst the various separation techniques, liquid membrane based separation methods are becoming increasingly popular due to factors such as ligand economy, high efficiency and low power consumption. Techniques such as emulsion liquid membrane (ELM) and hollow fibre supported liquid membrane (HFSLM) methods are reported to be more efficient than the solvent extraction based separation methods which have limitations of emulsion/third phase or crud formation. HFSLM technique offers the advantages of active transport, possible usage of exotic carriers and easy scale-up. For the past few years, Radiochemistry Division has been actively involved in the development of HFSLM separation processes for actinide partitioning, lanthanide/actinide separation, Sr/Y separation as well as recovery of radio-cesium from nuclear waste solutions. Similarly, ELM has major advantages of fast processing and large volume reduction factors. This lecture will give an overview of the HFSLM and ELM work carried out at Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai

  19. Liquid-phase separation with the rotational particle separator

    NARCIS (Netherlands)

    Kemenade, van H.P.; Mondt, E.; Hendriks, A.J.A.M.; Verbeek, P.H.J.

    2003-01-01

    Recently, the rotational particle separator (RPS) was introduced as a new technique for separating solid and/or liquid particles of 0.1 m and larger from gases. In this patented technique the principles of centrifugation are exploited to enhance separation of small-sized phases and particulate

  20. Origin of Reversible Photoinduced Phase Separation in Hybrid Perovskites.

    Science.gov (United States)

    Bischak, Connor G; Hetherington, Craig L; Wu, Hao; Aloni, Shaul; Ogletree, D Frank; Limmer, David T; Ginsberg, Naomi S

    2017-02-08

    The distinct physical properties of hybrid organic-inorganic materials can lead to unexpected nonequilibrium phenomena that are difficult to characterize due to the broad range of length and time scales involved. For instance, mixed halide hybrid perovskites are promising materials for optoelectronics, yet bulk measurements suggest the halides reversibly phase separate upon photoexcitation. By combining nanoscale imaging and multiscale modeling, we find that the nature of halide demixing in these materials is distinct from macroscopic phase separation. We propose that the localized strain induced by a single photoexcited charge interacting with the soft, ionic lattice is sufficient to promote halide phase separation and nucleate a light-stabilized, low-bandgap, ∼8 nm iodide-rich cluster. The limited extent of this polaron is essential to promote demixing because by contrast bulk strain would simply be relaxed. Photoinduced phase separation is therefore a consequence of the unique electromechanical properties of this hybrid class of materials. Exploiting photoinduced phase separation and other nonequilibrium phenomena in hybrid materials more generally could expand applications in sensing, switching, memory, and energy storage.

  1. Computation of subsonic flow around airfoil systems with multiple separation

    Science.gov (United States)

    Jacob, K.

    1982-01-01

    A numerical method for computing the subsonic flow around multi-element airfoil systems was developed, allowing for flow separation at one or more elements. Besides multiple rear separation also sort bubbles on the upper surface and cove bubbles can approximately be taken into account. Also, compressibility effects for pure subsonic flow are approximately accounted for. After presentation the method is applied to several examples and improved in some details. Finally, the present limitations and desirable extensions are discussed.

  2. Adjustment of milling plants to changed fuel qualities, Increase of performance of the mills MPS {sup registered} 180 at GK Kiel by means of an exchange of wing separators against lamellae separators; Anpassung von Mahlanlagen an veraenderte Brennstoffqualitaeten. Leistungssteigerung der Muehlen MPS {sup registered} 180 im GK Kiel durch den Austausch der Fluegelsichter gegen Lamellensichter

    Energy Technology Data Exchange (ETDEWEB)

    Boehme, Axel [Gemeinschaftskraftwerk Kiel GmbH, Kiel (Germany); Krause, Thomas [Hitachi Power Europe GmbH, Duisburg (Germany); Hufmann, Theo [E.ON Engineering GmbH, Gelsenkirchen (Germany)

    2008-07-01

    By means of heat and power generation, the municipal power station Kiel at the east bank of the Kieler Foerde has the possibility of uncoupling a thermal performance of up to 295 MW into the district heating grid of public utilities Kiel. The necessary conversion of the fuel required an increase of the performance of the mill in order to be able to grind the larger fuel flow during continuous boiler performance. For this, in the first step the exchange of the wing separators against lamella separators was selected. The authors of the contribution under consideration report on an adjustment of the crushing mills at changing fuel qualities.

  3. Steam-water separator

    International Nuclear Information System (INIS)

    Modrak, T.M.; Curtis, R.W.

    1978-01-01

    The steam-water separator connected downstream of a steam generator consists of a vertical centrifugal separator with swirl blades between two concentric pipes and a cyclone separator located above. The water separated in the cyclone separator is collected in the inner tube of the centrifugal separator which is closed at the bottom. This design allows the overall height of the separator to be reduced. (DG) [de

  4. Polymer-supported reagents with enhanced metal ion recognition: Application to separations science

    International Nuclear Information System (INIS)

    Alexandratos, S.D.

    1993-01-01

    The design and development of polymer-supported reagents with ever-increasing specificities for targeted metal ions remains an important areas of research. The need for efficient separation schemes for both ions and molecules has been outlined in a report by the National Research Council (King) and will gain increased emphasis as environmental restoration is pursued. Polymer-supported reagents are unique in their ability to be applied in an environmentally benign manner to a host of challenges. Such reagents, in the form of beads, can be applied to continuous separation processes ranging from the removal of metal ions in water to the recovery of medicinal drugs produced through biotechnological means. The application of polymer-supported reagents to metal ion separations still requires developing a fundamental understanding of ligand-metal interactions, the role of the polymer in those interactions, and the methods of synthesizing such polymeric reagents in a readily applicable form. Ion exchange resins with sulfonic acid ligands are the prototypical polymer-supported reagents, and their properties have been exhaustively studied (Helfferich). The high acidity of the sulfonic acid group, however, precludes much selectivity, and it displays a very limited range of reaction free energy values with different metal ions (Boyd et al.). The carboxylic acid ligand, present in the acrylate resins, is more selective, though its weak acidity requires relatively high pH solutions for it to be effective. Research has thus been focused on the preparation of polymer-supported reagents with high levels of specificity for targeted metal ions

  5. Development of Separation Materials Containing Palladium for Hydrogen Isotopes Separation

    International Nuclear Information System (INIS)

    Deng Xiaojun; Luo Deli; Qian Xiaojing

    2010-01-01

    Displacement chromatography (DC) is a ascendant technique for hydrogen isotopes separation. The performance of separation materials is a key factor to determine the separation effect of DC. At present,kinds of materials are researched, including palladium materials and non-palladium materials. It is hardly replaceable because of its excellent separation performance, although palladium is expensive. The theory of hydrogen isotopes separation using DC was introduced at a brief manner, while several palladium separation materials were expatiated in detail(Pd/K, Pd-Al 2 O 3 , Pd-Pt alloy). Development direction of separation materials for DC was forecasted elementarily. (authors)

  6. Lacan - a global simulation code for laser isotope separation

    International Nuclear Information System (INIS)

    Goldstein, S.; Quaegebeur, J.P.

    1990-01-01

    Dimensioning a Laser Isotope Separation (LIS) plant means calculating the values of a large number of parameters in order to optimize some objective function. In such algorithms the calculation of the objective function must be repeated thousands of times, therefore each elementary calculation must consume little time. LACAN uses simple models to describe the elementary physical processes: evaporation, vapour expansion, interaction between photons and atoms, ion extraction etc ... These simple models are derived from refined modeling codes or are empirical. As an example the optimization of the separative work of an uranium facility is discussed

  7. Apparatus for isotopic separation using a high-frequency wave and coherent radiation

    International Nuclear Information System (INIS)

    Mourier, G.

    1983-11-01

    The purpose of the present invention is an apparatus for industrial separation of isotopes, using a high-frequency electromagnetic field and coherent radiation such as that from a laser. Separation of isotopes by isotopically selective ionization, followed by entrainment of the ions by means of a magnetic field, is known. The selective ionization operation can be carried out in two consecutive stages: excitation of the chosen isotope, from the ground energy state to a specified excited level, near ionization; the energy required for this first stage can be supplied by means of a laser, the laser radiation being characterized for high power and well-defined frequency; this stage offers the advantage of being easily made isotopically selective; then ionization of the excited atoms by means of supplying relatively weak energy which should be insufficient to ionize the nonexcited ions; this second stage can also be carried out by means of a laser

  8. Russian separation program

    International Nuclear Information System (INIS)

    Rea, J.L.

    1993-01-01

    A small contract signed in FY92 with the Khlopin Radium Institute marked the beginning of the Russian Separations program. Under this contract the Khlopin Radium Institute performed laboratory and dynamic hot-cell testing using cobalt dicarbollide technology on simulated radioactive wastes similar to those found at DOE sites in the United States. The current scope of investigation has been extended to identify prospective technologies for application to other United States needs. The Khlopin Radium Institute project served as a model for three other pilot scale technology development projects. The premise of the pilot scale projects is to enable Russian scientists to demonstrate their technology in the context of DOE needs, using Russian technical expertise has proven to be a cost-effective means of screening Russian technologies

  9. Remarkable separability of circulation response to Arctic sea ice loss and greenhouse gas forcing

    Science.gov (United States)

    McCusker, K. E.; Kushner, P. J.; Fyfe, J. C.; Sigmond, M.; Kharin, V. V.; Bitz, C. M.

    2017-08-01

    Arctic sea ice loss may influence midlatitude climate by changing large-scale circulation. The extent to which climate change can be understood as greenhouse gas-induced changes that are modulated by this loss depends on how additive the responses to the separate influences are. A novel sea ice nudging methodology in a fully coupled climate model reveals that the separate effects of doubled atmospheric carbon dioxide (CO2) concentrations and associated Arctic sea ice loss are remarkably additive and insensitive to the mean climate state. This separability is evident in several fields throughout most of the year, from hemispheric to synoptic scales. The extent to which the regional response to sea ice loss sometimes agrees with and sometimes cancels the response to CO2 is quantified. The separability of the responses might provide a means to better interpret the diverse array of modeling and observational studies of Arctic change and influence.

  10. Experimental Research of Machineless Energy Separation Effect Influenced by Shock Waves

    Directory of Open Access Journals (Sweden)

    S. S. Popovich

    2016-01-01

    Full Text Available The paper presents experimental research results of machineless energy separation effect with transversal ribs in supersonic channel. The energy separation effect assumes a physical division of the inlet flow into two or more flows, each having different stagnation temperature. Among well-known energy separation effects noted there are Ranque-Hilsch vortex tubes, Hartmann-Sprenger resonance tubes, pulsating tubes and some others.A working principle of device under study is based on thermal interaction between subsonic and supersonic gas flows through a heat-conducting division wall. This energy separation method was proposed by academician Leontiev and was patented in 1998. A number of references for PhD theses, articles, and conference proceedings devoted to the research of “Leontiev tube” have been mentioned in the paper. Efficiency factors for energy separation device performability have been analyzed in detail. The main attention was focused on the phenomenon of shock waves generation in supersonic channel of Leontiev tube.Experiment was carried out in the air prototype of energy separation device with supersonic flow Mach numbers 1.9 and 2.5, stagnation temperatures 40°С and 70°С, and for uni-flow and counter-flow air moving direction in subsonic and supersonic channels. Shock waves have been generated by means of circular ribs in supersonic channel of energy separation device. The research was carried out by means of infrared thermal imaging, thermocouples, total and static pressure probes, and modern National Insturments automation equipment. The work shows that shock waves have no negative influence on energy separation effect. A conclusion is made that unexpected shock wave generation in supersonic channel will not cause operability loss. It was gained that counter-flow regime is more efficient than uni-flow. Energy separation effect also appears to be higher with the rise of Mach number and flow initial stagnation temperature

  11. Capacity limitations to extract the mean emotion from multiple facial expressions depend on emotion variance.

    Science.gov (United States)

    Ji, Luyan; Pourtois, Gilles

    2018-04-20

    We examined the processing capacity and the role of emotion variance in ensemble representation for multiple facial expressions shown concurrently. A standard set size manipulation was used, whereby the sets consisted of 4, 8, or 16 morphed faces each uniquely varying along a happy-angry continuum (Experiment 1) or a neutral-happy/angry continuum (Experiments 2 & 3). Across the three experiments, we reduced the amount of emotion variance in the sets to explore the boundaries of this process. Participants judged the perceived average emotion from each set on a continuous scale. We computed and compared objective and subjective difference scores, using the morph units and post-experiment ratings, respectively. Results of the subjective scores were more consistent than the objective ones across the first two experiments where the variance was relatively large, and revealed each time that increasing set size led to a poorer averaging ability, suggesting capacity limitations in establishing ensemble representations for multiple facial expressions. However, when the emotion variance in the sets was reduced in Experiment 3, both subjective and objective scores remained unaffected by set size, suggesting that the emotion averaging process was unlimited in these conditions. Collectively, these results suggest that extracting mean emotion from a set composed of multiple faces depends on both structural (attentional) and stimulus-related effects. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Size-selective separation of submicron particles in suspensions with ultrasonic atomization.

    Science.gov (United States)

    Nii, Susumu; Oka, Naoyoshi

    2014-11-01

    Aqueous suspensions containing silica or polystyrene latex were ultrasonically atomized for separating particles of a specific size. With the help of a fog involving fine liquid droplets with a narrow size distribution, submicron particles in a limited size-range were successfully separated from suspensions. Performance of the separation was characterized by analyzing the size and the concentration of collected particles with a high resolution method. Irradiation of 2.4MHz ultrasound to sample suspensions allowed the separation of particles of specific size from 90 to 320nm without regarding the type of material. Addition of a small amount of nonionic surfactant, PONPE20 to SiO2 suspensions enhanced the collection of finer particles, and achieved a remarkable increase in the number of collected particles. Degassing of the sample suspension resulted in eliminating the separation performance. Dissolved air in suspensions plays an important role in this separation. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Noble gas separation with the use of inorganic adsorbents

    International Nuclear Information System (INIS)

    Pence, D.T.; Chou, C.C.; Christian, J.D.; Paplawsky, W.J.

    1979-01-01

    A noble gas separation process is proposed for application to airborne nuclear fuel reprocessing plant effluents. The process involves the use of inorganic adsorbents for the removal of contaminant gases and noble gas separation through selective adsorption. Water and carbon dioxide are removed with selected zeolites that do not appreciably adsorb the noble gases. Xenon is essentially quantitatively removed with a specially developed adsorbent using conventional adsorption-desorption techniques. Oxygen is removed to low ppM levels by the use of a rapid cycle adsorption technique on a special adsorbent leaving a krypton-nitrogen mixture. Krypton is separated from nitrogen with a special adsorbent operated at about -80 0 C. Because the separation process does not require high pressures and oxygen is readily removed to sufficiently limit ozone formation to insignificant levels, appreciable capital and operating cost savings with this process are possible compared with other proposed processes. In addition, the proposed process is safer to operate

  14. Analyses of gust fronts by means of limited area NWP model outputs

    Czech Academy of Sciences Publication Activity Database

    Kašpar, Marek

    67-68, - (2003), s. 559-572 ISSN 0169-8095 R&D Projects: GA ČR GA205/00/1451 Institutional research plan: CEZ:AV0Z3042911 Keywords : gust front * limited area NWP model * output Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.012, year: 2003

  15. An almost general theory of mean size perception.

    Science.gov (United States)

    Allik, Jüri; Toom, Mai; Raidvee, Aire; Averin, Kristiina; Kreegipuu, Kairi

    2013-05-03

    A general explanation for the observer's ability to judge the mean size of simple geometrical figures, such as circles, was advanced. Results indicated that, contrary to what would be predicted by statistical averaging, the precision of mean size perception decreases with the number of judged elements. Since mean size discrimination was insensitive to how total size differences were distributed among individual elements, this suggests that the observer has a limited cognitive access to the size of individual elements pooled together in a compulsory manner before size information reaches awareness. Confirming the associative law of addition means, observers are indeed sensitive to the mean, not the sizes of individual elements. All existing data can be explained by an almost general theory, namely, the Noise and Selection (N&S) Theory, formulated in exact quantitative terms, implementing two familiar psychophysical principles: the size of an element cannot be measured with absolute accuracy and only a limited number of elements can be taken into account in the computation of the average size. It was concluded that the computation of ensemble characteristics is not necessarily a tool for surpassing the capacity limitations of perceptual processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Separation of FFA from Partially Hydrogenated Soybean Oil Hydrolysate by Means of Membrane Processing

    DEFF Research Database (Denmark)

    Jala, Ram Chandra Reddy; Guo, Zheng; Xu, Xuebing

    2011-01-01

    Different types of commercial porous and non-porous polymeric membranes have been investigated for their capabilities to separate free fatty acids (FFA) from hydrolysate of partially hydrogenated soybean oil. A regenerated cellulose (RC, PLAC) membrane exhibited the most prominent difference...... in rejection between FFA and glycerides and the highest flux (27 kg h−1 m−2) in hydrolysate ethanol solution. The results also showed that, besides the pore size of membrane, the membrane flux depended largely on the property matching between membrane and solvent, as observed (40 kg h−1 m−2) flux was achieved...... with methanol but no flux detected with hexane for PLAC. The polyvinyl alcohol (PVA, NTR-729 HF) and Polyamide (PA, NTR-759HR) membranes gave the second and third highest flux (10.1 and 5.7 kg h−1 m−2, respectively), where solute rejections for NTR-759HR were 95.9% for triacylglycerols (TG), 83...

  17. Can components in distortion-product otoacoustic emissions be separated?

    DEFF Research Database (Denmark)

    Christensen, Anders Tornvig; W. Purcell, David; Christensen, Flemming

    2012-01-01

    Otoacoustic emissions are signals emitted from the cochlea, either spontaneously or evoked by stimuli. Measured with an acoustic probe sealed in the ear-canal, they reveal information about a part of the mechanism of hearing that is otherwise inaccessible. Outer hair cells in the cochlea work...... to improve hearing sensitivity by means of nonlinear amplification, which produces distortion. In the measurement of otoacoustic emissions, two tones can be delivered to the cochlea to invoke this nonlinearity and elicit the distortion-product otoacoustic emission (DPOAE). DPOAEs arise mainly from two...... spatially separated generation mechanisms, thus making interpretation of DPOAE measurements complicated. In this study, we test whether or not source separation by group delays is equivalent to separation by time delays – either result is equally interesting to understand given the complexity of the cochlea...

  18. Deformation heterogeneities and their role in life-limiting fatigue failures in a two-phase titanium alloy

    International Nuclear Information System (INIS)

    Jha, Sushant K.; Szczepanski, Christopher J.; John, Reji; Larsen, James M.

    2015-01-01

    Fatigue crack-initiation sites in Ti–6Al–2Sn–4Zr–6Mo (Ti–6–2–4–6), an α + β titanium alloy used in turbine engine applications, were characterized with emphasis on distinguishing the microstructural neighborhoods and mechanisms that produce the life-limiting failures vs. those that promote the mean-lifetime behavior. The characterization methods included quantitative tilt fractography, focused ion beam milling across crack-initiation facets, and electron backscattered diffraction analysis. The motivation for discerning between the life-limiting and the mean-dominating crack-initiation microstructural neighborhoods stemmed from the previously developed understanding that the mean and the life-limiting behaviors respond differently to stress level (and many other variables), leading to an increasing separation between the two subpopulations as the stress level is decreased, thereby increasing the variability in lifetime. The different rates of response of the two behaviors was found to arise because the life-limiting mechanism was dominated by the crack-growth lifetime, with microstructural-scale crack-initiation occurring within the first few fatigue cycles, whereas the mean behavior was increasingly dominated by the crack-initiation lifetime as the stress level was decreased. Representative specimens for 2-D characterization of crack-initiation neighborhoods were selected from life-limiting and mean-dominating populations generated by fatigue tests on a duplex α + β phase microstructure of Ti–6–2–4–6 under a narrow range of applied stress amplitudes. A compilation of data on the crack-initiation facet and the neighborhood of the faceted grain from multiple specimens pointed to at least four categories of critical microstructural configurations, each representing a set of necessary (but perhaps not sufficient) conditions for crack-initiation in this alloy. Based on this characterization, a hypothesis for the life-limiting fatigue behavior

  19. Separation of the overlapping effects in spectra for WDXRF using the Rietveld method

    International Nuclear Information System (INIS)

    Salvador, Vera Lucia Ribeiro

    2005-01-01

    This work presents a new methodology for the overlapping spectra separation obtained by the technique of wavelength dispersion X-ray fluorescence (WDXRF). This methodology allows to improve the conventional analytic results and to facilitate the determination of chemical species of a same element without chemical separation, by means of the separation of coming spectra of electronic transitions of valence electrons or chemical effects in internal electrons. With the software 'GSAS-EXPGUI' and the method of Rietveld overcomes the problem of overlapping lines of the present species in the sample and it facilitates the determination of the same ones simultaneously, without the need of samples patterns and calibration curves, what means an expressive gain in relation to other techniques. The preparation of the surface of the sample for the collection of the spectrum represents a critical stage for the acting of the analysis whose effects can be minimized being used the refinement of Rietveld, that allows the determination of the relationships of the intensities of the lines put upon by means of mathematical models, what establishes the basic conditions for obtaining of more precise results in the quantitative analysis. In the case of the determination of chemical species it can separate, for example Cr (III), Cr (VI) and Fe (II), Fe(III) that present overlapping of almost 100%. (author)

  20. Model studies of limitation of carbon dioxide emissions reduction

    International Nuclear Information System (INIS)

    1992-01-01

    The report consists of two papers concerning mitigation of CO 2 emissions in Sweden, ''Limitation of carbon dioxide emissions. Socio-economic effects and the importance of international coordination'', and ''Model calculations for Sweden's energy system with carbon dioxide limitations''. Separate abstracts were prepared for both of the papers

  1. Separation of lanthanides through hydroxyapatite

    International Nuclear Information System (INIS)

    Garcia M, F.G.

    2006-01-01

    With the objective of obtaining from an independent way to each one of the lanthanides 151 Pm, 161 Tb, 166 Ho and 177 Lu free of carrier and with high specific activities starting from the indirect irradiation via, it intends in this work to determine the viability of separation of the couples Nd/Pm, Dy/Ho, Gd/Tb and Yb/Lu, by means of ion exchange column chromatography, using hydroxyapatite (HAp) and fluorite like absorbent material in complexing media. It is important to mention that have registered separation studies among lanthanides of the heavy group with those of the slight group, using the same mass and, in comparison with this work, quantities different from the father were used and of the son, also, that the separation studies were carried out among neighboring lanthanides. In this investigation, it was determined the effect that its have the complexing media: KSCN, sodium tartrate, sodium citrate, EDTA and aluminon, their pH and concentration, in the adsorption of the lanthanides in both minerals, in order to determine the chromatographic conditions for separation of the couples Nd/Pm, Dy/Ho, Gd/Tb and Yb/Lu. The work consists of five chapters, in the first one they are presented a theoretical introduction of the characteristics more important of the lanthanides, the hydroxyapatite and the fluorite; in the second, it is deepened in the ion exchange, as well as the two techniques (XRD and High Vacuum Electron Microscopy) to make the characterization of LnCI 3 (Ln = Nd, Gd, Dy or Yb) synthesized. The third chapter, it describes the methodology continued in our experimental work; in the room, its are presented the obtained results of the static and dynamic method to determine the viability of separation of neighboring lanthanides; and finally, the five chapter shows the conclusions. In this study, it is concludes that the separation among neighboring lanthanides cannot be carried out in the minerals and used media; because practically these lanthanides

  2. Novel, Ceramic Membrane System For Hydrogen Separation

    Energy Technology Data Exchange (ETDEWEB)

    Elangovan, S.

    2012-12-31

    Separation of hydrogen from coal gas represents one of the most promising ways to produce alternative sources of fuel. Ceramatec, teamed with CoorsTek and Sandia National Laboratories has developed materials technology for a pressure driven, high temperature proton-electron mixed conducting membrane system to remove hydrogen from the syngas. This system separates high purity hydrogen and isolates high pressure CO{sub 2} as the retentate, which is amenable to low cost capture and transport to storage sites. The team demonstrated a highly efficient, pressure-driven hydrogen separation membrane to generate high purity hydrogen from syngas using a novel ceramic-ceramic composite membrane. Recognizing the benefits and limitations of present membrane systems, the all-ceramic system has been developed to address the key technical challenges related to materials performance under actual operating conditions, while retaining the advantages of thermal and process compatibility offered by the ceramic membranes. The feasibility of the concept has already been demonstrated at Ceramatec. This project developed advanced materials composition for potential integration with water gas shift rectors to maximize the hydrogenproduction.

  3. Citrate based ''TALSPEAK'' lanthanide-actinide separation process

    International Nuclear Information System (INIS)

    Del Cul, G.D.; Bond, W.D.; Toth, L.M.; Davis, G.D.; Dai, S.; Metcalf, D.H.

    1994-09-01

    The potential hazard posed to future generations by long-lived radionuclides such as the transuranic elements (TRU) is perceived as a major problem associated with the use of nuclear power. TRU wastes have to remain isolated from the environment for ''geological'' periods of time. The costs of building, maintaining, and operating a ''geological TRU repository'' can be very high. Therefore, there are significant economical advantages in segregating the relatively low volume of TRU wastes from other nuclear wastes. The chemical behavior of lanthanides and actinides, 4f and 5f elements respectively, is rather similar. As a consequence, the separation of these two groups is difficult. The ''TALSPEAK'' process (Trivalent Actinide Lanthanide Separations by Phosphorus-reagent Extraction from Aqueous Complexes) is one of the few means available to separate the trivalent actinides from the lanthanides. The method is based on the preferential complexation of the trivalent actinides by an aminopolyacetic acid. Cold experiments showed that by using citric acid the deleterious effects produced by impurities such as zirconium are greatly reduced

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

    Energy Technology Data Exchange (ETDEWEB)

    Nestler, Tina; Schmid, Robert; Münchgesang, Wolfram; Bazhenov, Vasilii; Meyer, Dirk C. [Technische Universität Bergakademie Freiberg, Institut für Experimentelle Physik, Leipziger Str. 23, 09596 Freiberg (Germany); Schilm, Jochen [Fraunhofer-Institut für Keramische Technologien und Systeme IKTS, Winterbergstraße 28, 01277 Dresden (Germany); Leisegang, Tilmann [Fraunhofer-Technologiezentrum Halbleitermaterialien THM, Am St.-Niclas-Schacht 13, 09599 Freiberg (Germany)

    2014-06-16

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

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

    Science.gov (United States)

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

    2014-06-01

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

  6. Two-bunch operation with ns temporal separation at the FERMI FEL facility

    Science.gov (United States)

    Penco, Giuseppe; Allaria, Enrico; Bassanese, Silvano; Cinquegrana, Paolo; Cleva, Stefano; Danailov, Miltcho B.; Demidovich, Alexander; Ferianis, Mario; Gaio, Giulio; Giannessi, Luca; Masciovecchio, Claudio; Predonzani, Mauro; Rossi, Fabio; Roussel, Eleonore; Spampinati, Simone; Trovò, Mauro

    2018-05-01

    In the last decade, a continuous effort has been dedicated to extending the capabilities of existing free-electron lasers (FELs) operating in the x-ray and vacuum ultraviolet regimes. In this framework, the generation of two-color (or multi-color) temporally separated FEL pulses, has paved the way to new x-ray pump and probe experiments and several two-color two-pulse schemes have been implemented at the main facilities, but with a generally limited time-separation between the pulses, from 0 to few hundreds of fs. This limitation may be overcome by generating light with two independent electron bunches, temporally separated by integral multiples of the radio-frequency period. This solution was investigated at FERMI, measurements and characterization of this two-bunch mode of operation are presented, including trajectory control, impact of longitudinal and transverse wakefields, manipulation of the longitudinal phase space and finally a demonstration of suitability of the scheme to provide extreme ultraviolet light by using both bunches.

  7. Mean-field theory of nuclear structure and dynamics

    International Nuclear Information System (INIS)

    Negele, J.W.

    1982-01-01

    The physical and theoretical foundations are presented for the mean-field theory of nuclear structure and dynamics. Salient features of the many-body theory of stationary states are reviewed to motivate the time-dependent mean-field approximation. The time-dependent Hartree-Fock approximation and its limitations are discussed and general theoretical formulations are presented which yield time-dependent mean-field equations in lowest approximation and provide suitable frameworks for overcoming various conceptual and practical limitations of the mean-field theory. Particular emphasis is placed on recent developments utilizing functional integral techniques to obtain a quantum mean-field theory applicable to quantized eigenstates, spontaneous fission, the nuclear partition function, and scattering problems. Applications to a number of simple, idealized systems are presented to verify the approximations for solvable problems and to elucidate the essential features of mean-field dynamics. Finally, calculations utilizing moderately realistic geometries and interactions are reviewed which address heavy-ion collisions, fusion, strongly damped collisions, and fission

  8. Particle separation by phase modulated surface acoustic waves.

    Science.gov (United States)

    Simon, Gergely; Andrade, Marco A B; Reboud, Julien; Marques-Hueso, Jose; Desmulliez, Marc P Y; Cooper, Jonathan M; Riehle, Mathis O; Bernassau, Anne L

    2017-09-01

    High efficiency isolation of cells or particles from a heterogeneous mixture is a critical processing step in lab-on-a-chip devices. Acoustic techniques offer contactless and label-free manipulation, preserve viability of biological cells, and provide versatility as the applied electrical signal can be adapted to various scenarios. Conventional acoustic separation methods use time-of-flight and achieve separation up to distances of quarter wavelength with limited separation power due to slow gradients in the force. The method proposed here allows separation by half of the wavelength and can be extended by repeating the modulation pattern and can ensure maximum force acting on the particles. In this work, we propose an optimised phase modulation scheme for particle separation in a surface acoustic wave microfluidic device. An expression for the acoustic radiation force arising from the interaction between acoustic waves in the fluid was derived. We demonstrated, for the first time, that the expression of the acoustic radiation force differs in surface acoustic wave and bulk devices, due to the presence of a geometric scaling factor. Two phase modulation schemes are investigated theoretically and experimentally. Theoretical findings were experimentally validated for different mixtures of polystyrene particles confirming that the method offers high selectivity. A Monte-Carlo simulation enabled us to assess performance in real situations, including the effects of particle size variation and non-uniform acoustic field on sorting efficiency and purity, validating the ability to separate particles with high purity and high resolution.

  9. Separation of argon isotopes by porous membrane method, (2)

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Fujine, Sachio; Saito, Keiichiro; Ouchi, Misao; Naruse, Yuji

    1979-08-01

    Separation characteristics of an engineering-scale cascade equipment, which is composed of five stages using Al 2 O 3 barriers, were examined under different operating conditions. This report describes the results of the separation experiment of argon isotopes by the square cascade operated under total reflux. The results are as follows: (1) Mean pore diameter and tortuosity of the barriers were estimated to be 400A and 13-15, respectively. (2) Flow mechanism through the barriers was proved to be ideal Knudsen flow by measurement of the permeability. (3) The cascade was equilibriated in 30-40 minutes, depending on stage gas inventory. (4) The effect of an operating pressure on the separation factor could be estimated by Knudsen's and Present-deBethune's theories. (5) The stage separation factor could be estimated by the conventional theoretical equations by introducing a correction factor as a function of Reynolds number of the permeating flow through the barriers. (6) An experimental equation to estimate the flow effect on the separation factor was obtained considering velocity and physical properties of the gas in the vicinity of the barrier surface. (author)

  10. Separation of alkali metals by extraction chromatography using polyethers

    International Nuclear Information System (INIS)

    Smulek, W.; Lada, W.

    1977-01-01

    Separation of alkali metals by means of acyclic polyether 1,13 bis(8-chinolinyl)1, 4, 7, 10, 13 pentaoxatridecane (CPOD) and cyclic polyether dibenzo-18-crown-6 (DBC) using extraction chromatography is described. Solutions of NaSCN were used as eluting agents. The separation ability of the polyether columns strongly depends on pH and temperature. The following radioisotopes were used in the experiments: Na-22, K-42, Rb-86 and Cs-137. The radionuclide purity of the tracers was examined by γ-ray spectrometry using a Ge(Li) detector and a multichannel γ-ray spectrometer. (T.I.)

  11. Prediction of fluctuating pressure environments associated with plume-induced separated flow fields

    Science.gov (United States)

    Plotkin, K. J.

    1973-01-01

    The separated flow environment induced by underexpanded rocket plumes during boost phase of rocket vehicles has been investigated. A simple semi-empirical model for predicting the extent of separation was developed. This model offers considerable computational economy as compared to other schemes reported in the literature, and has been shown to be in good agreement with limited flight data. The unsteady pressure field in plume-induced separated regions was investigated. It was found that fluctuations differed from those for a rigid flare only at low frequencies. The major difference between plume-induced separation and flare-induced separation was shown to be an increase in shock oscillation distance for the plume case. The prediction schemes were applied to PRR shuttle launch configuration. It was found that fluctuating pressures from plume-induced separation are not as severe as for other fluctuating environments at the critical flight condition of maximum dynamic pressure.

  12. Testing the coherence between occupational exposure limits for inhalation and their biological limit values with a generalized PBPK-model: the case of 2-propanol and acetone.

    Science.gov (United States)

    Huizer, Daan; Huijbregts, Mark A J; van Rooij, Joost G M; Ragas, Ad M J

    2014-08-01

    The coherence between occupational exposure limits (OELs) and their corresponding biological limit values (BLVs) was evaluated for 2-propanol and acetone. A generic human PBPK model was used to predict internal concentrations after inhalation exposure at the level of the OEL. The fraction of workers with predicted internal concentrations lower than the BLV, i.e. the 'false negatives', was taken as a measure for incoherence. The impact of variability and uncertainty in input parameters was separated by means of nested Monte Carlo simulation. Depending on the exposure scenario considered, the median fraction of the population for which the limit values were incoherent ranged from 2% to 45%. Parameter importance analysis showed that body weight was the main factor contributing to interindividual variability in blood and urine concentrations and that the metabolic parameters Vmax and Km were the most important sources of uncertainty. This study demonstrates that the OELs and BLVs for 2-propanol and acetone are not fully coherent, i.e. enforcement of BLVs may result in OELs being violated. In order to assess the acceptability of this "incoherence", a maximum population fraction at risk of exceeding the OEL should be specified as well as a minimum level of certainty in predicting this fraction. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Wet separation processes as method to separate limestone and oil shale

    Science.gov (United States)

    Nurme, Martin; Karu, Veiko

    2015-04-01

    Biggest oil shale industry is located in Estonia. Oil shale usage is mainly for electricity generation, shale oil generation and cement production. All these processes need certain quality oil shale. Oil shale seam have interlayer limestone layers. To use oil shale in production, it is needed to separate oil shale and limestone. A key challenge is find separation process when we can get the best quality for all product types. In oil shale separation typically has been used heavy media separation process. There are tested also different types of separation processes before: wet separation, pneumatic separation. Now oil shale industry moves more to oil production and this needs innovation methods for separation to ensure fuel quality and the changes in quality. The pilot unit test with Allmineral ALLJIG have pointed out that the suitable new innovation way for oil shale separation can be wet separation with gravity, where material by pulsating water forming layers of grains according to their density and subsequently separates the heavy material (limestone) from the stratified material (oil shale)bed. Main aim of this research is to find the suitable separation process for oil shale, that the products have highest quality. The expected results can be used also for developing separation processes for phosphorite rock or all others, where traditional separation processes doesn't work property. This research is part of the study Sustainable and environmentally acceptable Oil shale mining No. 3.2.0501.11-0025 http://mi.ttu.ee/etp and the project B36 Extraction and processing of rock with selective methods - http://mi.ttu.ee/separation; http://mi.ttu.ee/miningwaste/

  14. Magnetic separation technique for environmental water purification by strong magnetic field generator loading HTS bulk magnets

    International Nuclear Information System (INIS)

    Oka, T.; Tanaka, K.; Kimura, T.; Mimura, D.; Fukui, S.; Ogawa, J.; Sato, T.; Ooizumi, M.; Yokoyama, K.; Yamaguchi, M.

    2010-01-01

    The magnetic separation technique in combination with high temperature superconducting bulk magnets has been investigated to purify the ground water which has been used in the coolant system for the incinerator furnace to cool the burning gas. The experiment has been operated by means of the newly-built alternating channel type magnetic separating device. The separation ratios of ferromagnetic flocks including fine magnetite powder have been estimated by means of the high gradient magnetic separation method with small iron balls filled in the water channels. As the magnetic force acting on the magnetic particle is given by the product of a magnetization of the material and a gradient of magnetic field, and as the ferromagnetic stainless steel balls yield the steep gradient of magnetic field around them in a strong magnetic field, the system has exhibited a quite excellent performance with respect to the separation ratios. The separation ratios of the flocks which contain the magnetite powder with the values more than 50 ppm have remained over 80% for under the flow rates less than 5 L/min.

  15. Towards a magnetic field separation in Ion Beam Sputtering processes

    Energy Technology Data Exchange (ETDEWEB)

    Malobabic, Sina, E-mail: s.malobabic@lzh.de [Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover (Germany); Quest: Centre of Quantum Engineering and Space-Time Research, Leibniz Universität Hannover (Germany); Jupé, Marco [Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover (Germany); Quest: Centre of Quantum Engineering and Space-Time Research, Leibniz Universität Hannover (Germany); Kadhkoda, Puja [Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover (Germany); Ristau, Detlev [Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover (Germany); Quest: Centre of Quantum Engineering and Space-Time Research, Leibniz Universität Hannover (Germany)

    2015-10-01

    Defects embedded in coatings due to particle contamination are considered as a primary factor limiting the quality of optical coatings in Ion Beam Sputtering. An approach combining the conventional Ion Beam Sputtering process with a magnetic separator in order to remove these particles from film growth is presented. The separator provides a bent axial magnetic field that guides the material flux towards the substrate positioned at the exit of the separator. Since there is no line of sight between target and substrate, the separator prevents that the particles generated in the target area can reach the substrate. In this context, optical components were manufactured that reveal a particle density three times lower than optical components which were deposited using a conventional Ion Beam Sputtering process. - Highlights: • We use bent magnetic fields to guide and separate the sputtered deposition material. • No line of sight between substrate and target prevents thin films from particles. • The transport efficiency of binary and ternary oxides is investigated. • The defect statistics of manufactured dielectric ternary multilayers are evaluated. • The phase separation leads to a drastically reduction of particle contamination.

  16. 5 CFR 5201.102 - Designation of separate agency components.

    Science.gov (United States)

    2010-01-01

    ... ETHICAL CONDUCT FOR EMPLOYEES OF THE DEPARTMENT OF LABOR § 5201.102 Designation of separate agency...) Office of Labor-Management Standards. (c) Definitions—(1) Remainder of the Department means employees in... prohibited source of gifts for MSHA employees. The contractor is not regulated by and has no business...

  17. Child Temperament Moderates the Impact of Parental Separation on Adolescent Mental Health : The TRAILS Study

    NARCIS (Netherlands)

    Sentse, Miranda; Ormel, Johan; Veenstra, Rene; Verhulst, Frank C.; Oldehinkel, Albertine J.

    The potential effect of parental separation during early adolescence on adolescent externalizing and internalizing problems was investigated in a longitudinal sample of adolescents (n = 1274; mean age = 16.27; 52.3% girls). Pre-separation mental health problems were controlled for. Building on a

  18. Determination of methyl mercury by aqueous phase Eehylation, followed by gas chromatographic separation with cold vapor atomic fluorescence detection

    Science.gov (United States)

    De Wild, John F.; Olsen, Mark L.; Olund, Shane D.

    2002-01-01

    A recent national sampling of streams in the United States revealed low methyl mercury concentrations in surface waters. The resulting median and mean concentrations, calculated from 104 samples, were 0.06 nanograms per liter (ng/L) and 0.15 ng/L, respectively. This level of methyl mercury in surface water in the United States has created a need for analytical techniques capable of detecting sub-nanogram per liter concentrations. In an attempt to create a U.S. Geological Survey approved method, the Wisconsin District Mercury Laboratory has adapted a distillation/ethylation/ gas-phase separation method with cold vapor atomic fluorescence spectroscopy detection for the determination of methyl mercury in filtered and unfiltered waters. This method is described in this report. Based on multiple analyses of surface water and ground-water samples, a method detection limit of 0.04 ng/L was established. Precision and accuracy were evaluated for the method using both spiked and unspiked ground-water and surface-water samples. The percent relative standard deviations ranged from 10.2 to 15.6 for all analyses at all concentrations. Average recoveries obtained for the spiked matrices ranged from 88.8 to 117 percent. The precision and accuracy ranges are within the acceptable method-performance limits. Considering the demonstrated detection limit, precision, and accuracy, the method is an effective means to quantify methyl mercury in waters at or below environmentally relevant concentrations

  19. Separation of a light additive gas by separation nozzle cascades

    International Nuclear Information System (INIS)

    Becker, E.; Bley, P.; Ehrfeld, W.; Fritz, W.; Steinhaus, H.

    1984-01-01

    Double-turn separation nozzles, in comparison with single-turn separation nozzles, offer much greater advantages in the separation of UF6 and H2 than in the separation of the U isotopes, for which the double-turn separation nozzles were conceived. By using a double-turn separation-nozzle stage as a preseparation stage in combination with a low-temperature separator, one can reduce the ratio of the buffer input stream to the product stream, in contrast with the solution used up to this time, with only a slight increase in cost of about an order of magnitude. The control program in the case of return feeding of the UF6 from the buffer and the danger of production losses connected with it are thereby correspondingly diminished. An example is given of the enrichment of 235U using the title facility with UF6. (orig./PW)

  20. Cesium separation using integrated electro-membrane technique

    International Nuclear Information System (INIS)

    Fors, Patrik; Lillfors-Pintér, Christina; Widestrand, Henrik; Velin, Anna; Bengtsson, Bernt

    2014-01-01

    Conventional separation technologies such as ion exchange, electro-deionisation and cross flow filtration are not always effective to eliminate nuclides, which are weekly ionised, complexed or hydrated in effluents. Specific nuclide selective absorbers perform well for the treatment of active and contaminated wastewaters but most absorbers generate additional waste while treating high volumes of contaminated water and often show limitations in operating at high flow rates. Electrochemical Ion Exchange (EIX) and EIX in combination with absorbers may offer an alternative solution that overcomes those limitations. This paper reports on the optimization and performance of the integrated technique EIX, for the treatment of low activity effluents that contain cesium and other nuclides. The three-compartment EIX system, which operates with authentic reactor coolant with enhanced nuclide content, indicates high, over 90%, elimination of cesium in a single pass operation mode. With the in-situ and instant ion exchange regeneration, the system successfully reduces the activity from an initial range of 400-2600 Bq/kg to close to detection limit at a velocity of 10-15 cm/min. The applied current density varies between 50-200 mA/cm 2 and the mass balance is close to 100%. During the process, the eliminated cesium and other nuclides are concentrated up to the limits where reverse migration from the concentrated chamber occurs. The concentrate could then be treated with specific absorbents at low flow rates. EIX in combination with cesium-selective ion exchanger CsTreat ® separates the cesium-137 efficiently, but up to now the process does not perform according to EIX principles for the treatment of low grade radioactive wastewaters it rather performs as an irreversible adsorber. The aim with the outcome of the presently ongoing long-term tests is to further support the Best Available Technique Minimizing All Nuclide (BATMAN) projects of Vattenfall NPPs. (author)

  1. On the problems of separation work unit for the laser isotope separation

    International Nuclear Information System (INIS)

    Wang, Lijun

    2008-01-01

    The concept of separation power or separation work, which is widely used in Uranium isotope separation industry is introduced historically for the weak separating machine and so-called 'ideal cascade'. Therefore, when this concept is applied to a laser isotope separation facility, which is deeply different from a cascade in structure and in mechanism of separation, some confusions may occur. By comparison the costs of SWU of laser isotope separation facility and an ideal cascade we come to a conclusion: the concept of separation work is not applicable for laser isotope separation. In order to compare the economics of laser isotope separation technique with diffusion or centrifugation techniques an equivalent cost of SWU is suggested in this paper. (author)

  2. Separation from supported employment: a retrospective chart review study.

    Science.gov (United States)

    West, Michael; Targett, Pamela; Wehman, Paul; Cifu, Gabriella; Davis, Jacob

    2015-01-01

    The objective of this study was to examine job separations from supported employment (SE). The aim was to identify the types and nature of separations and precipitating events leading to the separation. A retrospective chart review methodology was utilized. The study was conducted in a metropolitan area in the Southeast United States by a university-based SE program. Participants were 47 SE clients who had been placed into and separated from 67 jobs. Using a coding form, information regarding the type of separation and issues that preceded the separation were recorded. Data were aggregated using descriptive statistics. The largest number of separations was due to termination, followed by resignation and mutual consent of the employer and employee. The mean number of issues leading to the separation was 2.2, ranging from one to five. Only eight positive issues were found (compared to 116 negative and 20 neutral), the most prevalent being entry into an educational or training program. Common negative issues included poor work performance, attendance and punctuality problems, conflicts with the supervisor, and social and behavioral issues. The findings of this study illustrate the need to address job retention issues during the job development process, finding the most appropriate person-job fit and workplace culture for each client. The findings also support the need for vigilant and regular communication between the SE program and employers to intervene quickly when problems arise. Separation from Supported Employment (SE) SE is an evidence-based employment practice that has been shown effective across multiple disability groups. Studying job separations can provide valuable information for improving service. Locating the best person-job fit, as well as frequent contract with employers, can help prevent unnecessary job loss.

  3. Future directions for separation science in nuclear and radiochemistry

    International Nuclear Information System (INIS)

    Pruett, D.J.

    1986-01-01

    Solvent extraction and ion exchange have been the most widely used separation techniques in nuclear and radiochemistry since their development in the 1940s. Many successful separations processes based on these techniques have been used for decades in research laboratories, analytical laboratories, and industrial plants. Thus, it is easy to conclude that most of the fundamental and applied research that is needed in these areas has been done, and that further work in these ''mature'' fields is unlikely to be fruitful. A more careful review, however, reveals that significant problems remain to be solved, and that there is a demand for the development of new reagents, methods, and systems to solve the increasingly complex separations problems in the nuclear field. Specifically, new separation techniques based on developments in membrane technology and biotechnology that have occurred over the last 20 years should find extensive applications in radiochemical separations. Considerable research is needed in such areas as interfacial chemistry, the design and control of highly selective separation agents, critically evaluated data bases and mathematical models, and the fundamental chemistry of dilute solutions if these problems are to be solved and new techniques developed in a systematic way. Nonaqueous separation methods, such as pyrochemical and fluoride volatility processes, have traditionally played a more limited role in nuclear and radiochemistry, but recent developments in the chemistry and engineering of these processes promises to open up new areas of research and application in the future

  4. Basic separative power of multi-component isotopes separation in a gas centrifuge

    International Nuclear Information System (INIS)

    Jiang, Hongmin; Lei, Zengguang; Zhuge, Fu

    2008-01-01

    On condition that the overall separation factor per unit exists in centrifuge for multi-component isotopes separation, the relations between separative power of each component and molecular weight have been investigated in the paper while the value function and the separative power of binary-component separation are adopted. The separative power of each component is proportional to the square of the molecular weight difference between its molecular weight and the average molecular weight of other remnant components. In addition, these relations are independent on the number of the components and feed concentrations. The basic separative power and related expressions, suggested in the paper, can be used for estimating the separative power of each component and analyzing the separation characteristics. The most valuable application of the basic separative power is to evaluate the separative capacity of centrifuge for multi-component isotopes. (author)

  5. Improving Sound Systems by Electrical Means

    OpenAIRE

    Schneider, Henrik; Andersen, Michael A. E.; Knott, Arnold

    2015-01-01

    The availability and flexibility of audio services on various digital platforms have created a high demand for a large range of sound systems. The fundamental components of sound systems such as docking stations, sound bars and wireless mobile speakers consists of a power supply, amplifiers and transducers. Due to historical reasons the design of each of these components are commonly handled separately which are indeed limiting the full performance potential of such systems. To state some exa...

  6. Nanoparticle separation with a miniaturized asymmetrical flow field-flow fractionation cartridge

    Science.gov (United States)

    Müller, David; Cattaneo, Stefano; Meier, Florian; Welz, Roland; deMello, Andrew

    2015-07-01

    Asymmetrical Flow Field-Flow Fractionation (AF4) is a separation technique applicable to particles over a wide size range. Despite the many advantages of AF4, its adoption in routine particle analysis is somewhat limited by the large footprint of currently available separation cartridges, extended analysis times and significant solvent consumption. To address these issues, we describe the fabrication and characterization of miniaturized AF4 cartridges. Key features of the scale-down platform include simplified cartridge and reagent handling, reduced analysis costs and higher throughput capacities. The separation performance of the miniaturized cartridge is assessed using certified gold and silver nanoparticle standards. Analysis of gold nanoparticle populations indicates shorter analysis times and increased sensitivity compared to conventional AF4 separation schemes. Moreover, nanoparticulate titanium dioxide populations exhibiting broad size distributions are analyzed in a rapid and efficient manner. Finally, the repeatability and reproducibility of the miniaturized platform are investigated with respect to analysis time and separation efficiency.

  7. Membrane-based technologies for biogas separations.

    Science.gov (United States)

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

    2010-02-01

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

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

    Science.gov (United States)

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

    2016-01-12

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

  9. Development of the Two Phase Flow Separator Experiment for a Reduced Gravity Aircraft Flight

    Science.gov (United States)

    Golliher, Eric; Gotti, Daniel; Owens, Jay; Gilkey, Kelly; Pham, Nang; Stehno, Philip

    2016-01-01

    The recent hardware development and testing of a reduced gravity aircraft flight experiment has provided valuable insights for the future design of the Two Phase Flow Separator Experiment (TPFSE). The TPFSE is scheduled to fly within the Fluids Integration Rack (FIR) aboard the International Space Station (ISS) in 2020. The TPFSE studies the operational limits of gas and liquid separation of passive cyclonic separators. A passive cyclonic separator utilizes only the inertia of the incoming flow to accomplish the liquid-gas separation. Efficient phase separation is critical for environmental control and life support systems, such as recovery of clean water from bioreactors, for long duration human spaceflight missions. The final low gravity aircraft flight took place in December 2015 aboard NASA's C9 airplane.

  10. Electrical Insulation Of Carbon Nanotube Separation Columns For Microchip Electrochromatography

    DEFF Research Database (Denmark)

    Mogensen, Klaus Bo; Chen, Miaoxiang Max; Mølhave, Kristian

    2011-01-01

    Carbon nanotubes (CNT) have been grown in microfluidic glass channels for chemical analysis based on electrokinetic separations. A limitation of CNTs for this type of application is their high conductivity, which prevent them from being used for electroosmotic pumping with electrical field streng...

  11. Rapid chemical separations

    CERN Document Server

    Trautmann, N

    1976-01-01

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

  12. Separation of viable lactic acid bacteria from fermented milk

    Directory of Open Access Journals (Sweden)

    Tomohiko Nishino

    2018-04-01

    Full Text Available Probiotics are live microorganisms that provide health benefits to humans. Some lactic acid bacteria (LAB are probiotic organisms used in the production of fermented foods, such as yogurt, cheese, and pickles. Given their widespread consumption, it is important to understand the physiological state of LAB in foods such as yogurt. However, this analysis is complicated, as it is difficult to separate the LAB from milk components such as solid curds, which prevent cell separation by dilution or centrifugation. In this study, we successfully separated viable LAB from yogurt by density gradient centrifugation. The recovery rate was >90 %, and separation was performed until the stationary phase. Recovered cells were observable by microscopy, meaning that morphological changes and cell viability could be directly detected at the single-cell level. The results indicate that viable LAB can be easily purified from fermented milk. We expect that this method will be a useful tool for the analysis of various aspects of probiotic cells, including their enzyme activity and protein expression. Keywords: Food analysis, Microbiology

  13. Gas-centrifuge unit and centrifugal process for isotope separation

    International Nuclear Information System (INIS)

    Stark, T.M.

    1979-01-01

    An invention involving a process and apparatus for isotope-separation applications such as uranium-isotope enrichment is disclosed which employs cascades of gas centrifuges. A preferred apparatus relates to an isotope-enrichment unit which includes a first group of cascades of gas centrifuges and an auxiliary cascade. Each cascade has an input, a light-fraction output, and a heavy-fraction output for separating a gaseous-mixture feed including a compound of a light nuclear isotope and a compound of a heavy nuclear isotope into light and heavy fractions respectively enriched and depleted in the light isotope. The cascades of the first group have at least one enriching stage and at least one stripping stage. The unit further includes means for introducing a gaseous-mixture feedstock into each input of the first group of cascades, means for withdrawing at least a portion of a product fraction from the light-fraction outputs of the first group of cascades, and means for withdrawing at least a portion of a waste fraction from the heavy-fraction outputs of the first group of cascades. The isotope-enrichment unit also includes a means for conveying a gaseous-mixture from a light-fraction output of a first cascade included in the first group to the input of the auxiliary cascade so that at least a portion of a light gaseous-mixture fraction produced by the first group of cascades is further separated into a light and a heavy fraction by the auxiliary cascade. At least a portion of a product fraction is withdrawn from the light fraction output of the auxiliary cascade. If the light-fraction output of the first cascade and the heavy-fraction output of the auxiliary cascade are reciprocal outputs, the concentraton of the light isotope in the heavy fraction produced by the auxiliary cascade essentially equals the concentration of the light isotope in the gaseous-mixture feedstock

  14. Separable states improve protocols with finite randomness

    International Nuclear Information System (INIS)

    Bobby, Tan Kok Chuan; Paterek, Tomasz

    2014-01-01

    It is known from Bell's theorem that quantum predictions for some entangled states cannot be mimicked using local hidden variable (LHV) models. From a computer science perspective, LHV models may be interpreted as classical computers operating on a potentially infinite number of correlated bits originating from a common source. As such, Bell inequality violations achieved through entangled states are able to characterize the quantum advantage of certain tasks, so long as the task itself imposes no restriction on the availability of correlated bits. However, if the number of shared bits is limited, additional constraints are placed on the possible LHV models, and separable, i.e. disentangled states may become a useful resource. Bell violations are therefore no longer necessary to achieve a quantum advantage. Here we show that, in particular, separable states improve the so-called random access codes, which is a class of communication problem wherein one party tries to read a portion of the data held by another distant party in the presence of finite shared randomness and limited classical communication. We also show how the bias of classical bits can be used to avoid wrong answers in order to achieve the optimal classical protocol and how the advantage of quantum protocols is linked to quantum discord. (paper)

  15. Spin-charge separation in ultra-cold quantum gases

    OpenAIRE

    Recati, A.; Fedichev, P. O.; Zwerger, W.; Zoller, P.

    2002-01-01

    We investigate the physical properties of quasi-1D quantum gases of fermion atoms confined in harmonic traps. Using the fact that for a homogeneous gas, the low energy properties are exactly described by a Luttinger model, we analyze the nature and manifestations of the spin-charge separation. Finally we discuss the necessary physical conditions and experimental limitations confronting possible experimental implementations.

  16. Harnessing electro driven separation technique for the separation of selected agrochemicals

    International Nuclear Information System (INIS)

    Wan Aini Wan Ibrahim; Alam, S.M. Monjurul; Azli Sulaiman

    2008-01-01

    Electro driven separation techniques offer a different approach to the analysis of complex mixtures than do traditional pressure-driven chromatographic system; it may rely on electrophoresis, the transport of charged species through a medium by an applied field or may rely on electro driven mobile phase to provide a true chromatographic separation. In the current work the potential of an electro driven separation technique viz. Micellar electrokinetic chromatography (MEKC), is harnessed for the separation of selected agrochemicals (organophosphorus pesticides, OPPs) widely used in the agriculture sector in Malaysia. The current study compares the use of MEKC in normal mode (NM) and reverse mode (RM) for the separation of the selected OPPS. This study also highlights the difference in separations produced by performing separations in normal mode-MEKC (NM-MEKC) and reverse mode-MEKC (RM-MEKC) for the selected OPPs. In RM-MEKC, separation is conducted at acidic pH (pH 2.5 in the current work) where the electro osmotic flow (EOF) is weak whereas in NM-MEKC, the separation is carried out under basic pH (9.3 in this work) where the EOF is strong. A reverse migration order of the OPPs was observed under RM-MEKC. Separation under NM-MEKC was found to be superior to those of RM- MEKC. A comparison is also made between separations performed under sweeping-NM-MEKC and sweeping-RM-MEKC. In sweeping, the OPPs are prepared in the same background solution (BGS) minus the micelles and is adjusted to the same conductivity as the BGS. The study showed that NM-MEKC is more sensitive than RM-MEKC but sweeping-RM-MEKC is superior to sweeping-NM-MEKC. However, sweeping-RM-MEKC only separates two of the OPPs in a single run whereas sweeping-NM-MEKC separates four OPPs in a single run. The better choice of separation mode would be sweeping-NM- MEKC for more OPPs separation in a single run. (author)

  17. Effects of Surface Nonuniformities on the Mean Transverse Energy from Photocathodes

    Science.gov (United States)

    Karkare, Siddharth; Bazarov, Ivan

    2015-08-01

    The performance of photoinjectors is limited by the lowest value of the mean transverse energy of the electrons obtained from photocathodes. The factors that influence the mean transverse energy are poorly understood. In this paper, we develop models to calculate the effect of spatial work-function variations and subnanometer-scale roughness and surface defects on the mean transverse energy. We show that these can limit the lowest value of mean transverse energy achieved and that atomically perfect surfaces will be required to further reduce the mean transverse energy obtained from photocathodes.

  18. Separation of {sup 51}Cr by Means of the Szilard-Chalmers Effect from Potassium Chromate Irradiated at Low Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D

    1967-08-15

    The recombination of {sup 51}Cr in K{sub 2}CrO{sub 4} at low temperature as well as under dilute conditions has been investigated. Crystals of K{sub 2}CrO{sub 4} and a 1 % solution of this compound have been irradiated in a thermal column of a nuclear reactor. Lowering of the temperature was observed to cause a decrease in retention. Chemical separations have been carried out both at 0 C and at 20 deg C. The degree of enrichment was determined by reactivating one part of the solution after separation of the hexavalent chromium. Irradiation of K{sub 2}CrO{sub 4} in the frozen aqueous solution was observed to favour the degree of enrichment. The fate of the {sup 51}Cr recoil nuclide has been discussed in the light of the thermal spike theory.

  19. Computational Screening of MOFs for Acetylene Separation.

    Science.gov (United States)

    Nemati Vesali Azar, Ayda; Keskin, Seda

    2018-01-01

    Efficient separation of acetylene (C 2 H 2 ) from CO 2 and CH 4 is important to meet the requirement of high-purity acetylene in various industrial applications. Metal organic frameworks (MOFs) are great candidates for adsorption-based C 2 H 2 /CO 2 and C 2 H 2 /CH 4 separations due to their unique properties such as wide range of pore sizes and tunable chemistries. Experimental studies on the limited number of MOFs revealed that MOFs offer remarkable C 2 H 2 /CO 2 and C 2 H 2 /CH 4 selectivities based on single-component adsorption data. We performed the first large-scale molecular simulation study to investigate separation performances of 174 different MOF structures for C 2 H 2 /CO 2 and C 2 H 2 /CH 4 mixtures. Using the results of molecular simulations, several adsorbent performance evaluation metrics, such as selectivity, working capacity, adsorbent performance score, sorbent selection parameter, and regenerability were computed for each MOF. Based on these metrics, the best adsorbent candidates were identified for both separations. Results showed that the top three most promising MOF adsorbents exhibit C 2 H 2 /CO 2 selectivities of 49, 47, 24 and C 2 H 2 /CH 4 selectivities of 824, 684, 638 at 1 bar, 298 K and these are the highest C 2 H 2 selectivities reported to date in the literature. Structure-performance analysis revealed that the best MOF adsorbents have pore sizes between 4 and 11 Å, surface areas in the range of 600-1,200 m 2 /g and porosities between 0.4 and 0.6 for selective separation of C 2 H 2 from CO 2 and CH 4 . These results will guide the future studies for the design of new MOFs with high C 2 H 2 separation potentials.

  20. Computational Screening of MOFs for Acetylene Separation

    Science.gov (United States)

    Nemati Vesali Azar, Ayda; Keskin, Seda

    2018-02-01

    Efficient separation of acetylene (C2H2) from CO2 and CH4 is important to meet the requirement of high-purity acetylene in various industrial applications. Metal organic frameworks (MOFs) are great candidates for adsorption-based C2H2/CO2 and C2H2/CH4 separations due to their unique properties such as wide range of pore sizes and tunable chemistries. Experimental studies on the limited number of MOFs revealed that MOFs offer remarkable C2H2/CO2 and C2H2/CH4 selectivities based on single-component adsorption data. We performed the first large-scale molecular simulation study to investigate separation performances of 174 different MOF structures for C2H2/CO2 and C2H2/CH4 mixtures. Using the results of molecular simulations, several adsorbent performance evaluation metrics, such as selectivity, working capacity, adsorbent performance score, sorbent selection parameter and regenerability were computed for each MOF. Based on these metrics, the best adsorbent candidates were identified for both separations. Results showed that the top three most promising MOF adsorbents exhibit C2H2/CO2 selectivities of 49, 47, 24 and C2H2/CH4 selectivities of 824, 684, 638 at 1 bar, 298 K and these are the highest C2H2 selectivities reported to date in the literature. Structure-performance analysis revealed that the best MOF adsorbents have pore sizes between 4-11 Å, surface areas in the range of 600-1,200 m2/g and porosities between 0.4-0.6 for selective separation of C2H2 from CO2 and CH4. These results will guide the future studies for the design of new MOFs with high C2H2 separation potentials.

  1. Computational Screening of MOFs for Acetylene Separation

    Directory of Open Access Journals (Sweden)

    Ayda Nemati Vesali Azar

    2018-02-01

    Full Text Available Efficient separation of acetylene (C2H2 from CO2 and CH4 is important to meet the requirement of high-purity acetylene in various industrial applications. Metal organic frameworks (MOFs are great candidates for adsorption-based C2H2/CO2 and C2H2/CH4 separations due to their unique properties such as wide range of pore sizes and tunable chemistries. Experimental studies on the limited number of MOFs revealed that MOFs offer remarkable C2H2/CO2 and C2H2/CH4 selectivities based on single-component adsorption data. We performed the first large-scale molecular simulation study to investigate separation performances of 174 different MOF structures for C2H2/CO2 and C2H2/CH4 mixtures. Using the results of molecular simulations, several adsorbent performance evaluation metrics, such as selectivity, working capacity, adsorbent performance score, sorbent selection parameter, and regenerability were computed for each MOF. Based on these metrics, the best adsorbent candidates were identified for both separations. Results showed that the top three most promising MOF adsorbents exhibit C2H2/CO2 selectivities of 49, 47, 24 and C2H2/CH4 selectivities of 824, 684, 638 at 1 bar, 298 K and these are the highest C2H2 selectivities reported to date in the literature. Structure-performance analysis revealed that the best MOF adsorbents have pore sizes between 4 and 11 Å, surface areas in the range of 600–1,200 m2/g and porosities between 0.4 and 0.6 for selective separation of C2H2 from CO2 and CH4. These results will guide the future studies for the design of new MOFs with high C2H2 separation potentials.

  2. Equipment to separate liquid droplets from the cooling air stream of a liquid cooling tower

    International Nuclear Information System (INIS)

    Thompson, S.E.; Schwinn, J.M.

    1977-01-01

    In order to separate off liquid droplets from the air stream of a cooling tower, one uses separator blades that are secured to the supporting construction. An improvement on this is proposed to make the repairs easier. According to the invention, the separator blades should be fabricated from springy material with self-supporting strength and can be fitted onto the supporting construction by means of slits and notches. (RW) [de

  3. Rapid cell separation with minimal manipulation for autologous cell therapies

    Science.gov (United States)

    Smith, Alban J.; O'Rorke, Richard D.; Kale, Akshay; Rimsa, Roberts; Tomlinson, Matthew J.; Kirkham, Jennifer; Davies, A. Giles; Wälti, Christoph; Wood, Christopher D.

    2017-02-01

    The ability to isolate specific, viable cell populations from mixed ensembles with minimal manipulation and within intra-operative time would provide significant advantages for autologous, cell-based therapies in regenerative medicine. Current cell-enrichment technologies are either slow, lack specificity and/or require labelling. Thus a rapid, label-free separation technology that does not affect cell functionality, viability or phenotype is highly desirable. Here, we demonstrate separation of viable from non-viable human stromal cells using remote dielectrophoresis, in which an electric field is coupled into a microfluidic channel using shear-horizontal surface acoustic waves, producing an array of virtual electrodes within the channel. This allows high-throughput dielectrophoretic cell separation in high conductivity, physiological-like fluids, overcoming the limitations of conventional dielectrophoresis. We demonstrate viable/non-viable separation efficacy of >98% in pre-purified mesenchymal stromal cells, extracted from human dental pulp, with no adverse effects on cell viability, or on their subsequent osteogenic capabilities.

  4. Anomalous dispersion of magnetic spiky particles for enhanced oil emulsions/water separation.

    Science.gov (United States)

    Chen, Hui-Jiuan; Hang, Tian; Yang, Chengduan; Liu, Guishi; Lin, Di-An; Wu, Jiangming; Pan, Shuolin; Yang, Bo-Ru; Tao, Jun; Xie, Xi

    2018-01-25

    In situ effective separation of oil pollutants including oil spills and oil emulsions from water is an emerging technology yet remains challenging. Hydrophobic micro- or nano-materials with ferromagnetism have been explored for oil removal, yet the separation efficiency of an oil emulsion was compromised due to the limited dispersion of hydrophobic materials in water. A surfactant coating on microparticles prevented particle aggregation, but reduced oil absorption and emulsion cleaning ability. Recently, polystyrene microbeads covered with nanospikes have been reported to display anomalous dispersion in phobic media without surfactants. Inspired by this phenomenon, here magnetic microparticles attached with nanospikes were fabricated for enhanced separation of oil emulsions from water. In this design, the particle surfaces were functionalized to be superhydrophobic/superoleophilic for oil absorption, while the surface of the nanospikes prevented particle aggregation in water without compromising surface hydrophobicity. The magnetic spiky particles effectively absorbed oil spills on the water surface, and readily dispersed in water and offered facile cleaning of the oil emulsion. In contrast, hydrophobic microparticles without nanospikes aggregated in water limiting the particle-oil contact, while surfactant coating severely reduced particle hydrophobicity and oil absorption ability. Our work provides a unique application scope for the anomalous dispersity of microparticles and their potential opportunities in effective oil-water separation.

  5. Mean-field Ensemble Kalman Filter

    KAUST Repository

    Law, Kody; Tembine, Hamidou; Tempone, Raul

    2015-01-01

    A proof of convergence of the standard EnKF generalized to non-Gaussian state space models is provided. A density-based deterministic approximation of the mean-field limiting EnKF (MFEnKF) is proposed, consisting of a PDE solver and a quadrature

  6. Technical feasibility of advanced separation; Faisabilite technique de la separation poussee

    Energy Technology Data Exchange (ETDEWEB)

    Rostaing, Ch

    2004-07-01

    Advanced separation aims at reducing the amount and toxicity of high-level and long lived radioactive wastes. The Purex process has been retained as a reference way for the recovery of the most radio-toxic elements: neptunium, technetium and iodine. Complementary solvent extraction processes have to be developed for the separation of americium, curium and cesium from the high activity effluent of the spent fuel reprocessing treatment. Researches have been carried out with the aim of demonstrating the scientifical and technical feasibility of advanced separation of minor actinides and long lived fission products from spent fuels. The scientifical feasibility was demonstrated at the end of 2001. The technical feasibility works started in the beginning of 2002. Many results have been obtained which are presented and summarized in this document: approach followed, processes retained for the technical feasibility (An/Ln and Am/Cm separation), processes retained for further validation at the new shielded Purex installation, technical feasibility of Purex adaptation to Np separation, technical feasibility of Diamex (first step: (An+Ln)/other fission products) separation), technical feasibility of Sanex process (second step: An(III)/Ln(III) separation), technical feasibility of Am(III)/Cm(III) separation, cesium separation, iodine separation, technical-economical evaluation, conclusions and perspectives, facilities and apparatuses used for the experiments. (J.S.)

  7. Chromatographic Separations of Enantiomers and Underivatized Oligosaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ying [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    My graduate research has focused on separation science and bioanalytical analysis, which emphasized in method development. It includes three major areas: enantiomeric separations using high performance liquid chromatography (HPLC), Super/subcritical fluid chromatography (SFC), and capillary electrophoresis (CE); drug-protein binding behavior studies using CE; and carbohydrate analysis using liquid chromatograph-electrospray ionization mass spectrometry (LC-ESI-MS). Enantiomeric separations continue to be extremely important in the pharmaceutical industry. An in-depth evaluation of the enantiomeric separation capabilities of macrocyclic glycopeptides CSPs with SFC mobile phases was investigated using a set of over 100 chiral compounds. It was found that the macrocyclic based CSPs were able to separate enantiomers of various compounds with different polarities and functionalities. Seventy percent of all separations were achieved in less than 4 min due to the high flow rate (4.0 ml/min) that can be used in SFC. Drug-protein binding is an important process in determining the activity and fate of a drug once it enters the body. Two drug/protein systems have been studied using frontal analysis CE method. More sensitive fluorescence detection was introduced in this assay, which overcame the problem of low sensitivity that is common when using UV detection for drug-protein studies. In addition, the first usage of an argon ion laser with 257 nm beam coupled with CCD camera as a frontal analysis detection method enabled the simultaneous observation of drug fluorescence as well as the protein fluorescence. LC-ESI-MS was used for the separation and characterization of underivatized oligosaccharide mixtures. With the limits of detection as low as 50 picograms, all individual components of oligosaccharide mixtures (up to 11 glucose-units long) were baseline resolved on a Cyclobond I 2000 column and detected using ESI-MS. This system is characterized by high chromatographic

  8. Chromatographic Separations of Enantiomers and Underivatized Oligosaccharides

    International Nuclear Information System (INIS)

    Ying Liu

    2004-01-01

    My graduate research has focused on separation science and bioanalytical analysis, which emphasized in method development. It includes three major areas: enantiomeric separations using high performance liquid chromatography (HPLC), Super/subcritical fluid chromatography (SFC), and capillary electrophoresis (CE); drug-protein binding behavior studies using CE; and carbohydrate analysis using liquid chromatograph-electrospray ionization mass spectrometry (LC-ESI-MS). Enantiomeric separations continue to be extremely important in the pharmaceutical industry. An in-depth evaluation of the enantiomeric separation capabilities of macrocyclic glycopeptides CSPs with SFC mobile phases was investigated using a set of over 100 chiral compounds. It was found that the macrocyclic based CSPs were able to separate enantiomers of various compounds with different polarities and functionalities. Seventy percent of all separations were achieved in less than 4 min due to the high flow rate (4.0 ml/min) that can be used in SFC. Drug-protein binding is an important process in determining the activity and fate of a drug once it enters the body. Two drug/protein systems have been studied using frontal analysis CE method. More sensitive fluorescence detection was introduced in this assay, which overcame the problem of low sensitivity that is common when using UV detection for drug-protein studies. In addition, the first usage of an argon ion laser with 257 nm beam coupled with CCD camera as a frontal analysis detection method enabled the simultaneous observation of drug fluorescence as well as the protein fluorescence. LC-ESI-MS was used for the separation and characterization of underivatized oligosaccharide mixtures. With the limits of detection as low as 50 picograms, all individual components of oligosaccharide mixtures (up to 11 glucose-units long) were baseline resolved on a Cyclobond I 2000 column and detected using ESI-MS. This system is characterized by high chromatographic

  9. The deflection angle of a gravitational source with a global monopole in the strong field limit

    International Nuclear Information System (INIS)

    Cheng Hongbo; Man Jingyun

    2011-01-01

    We investigate the gravitational lensing effect in the strong field background around the Schwarzschild black hole with extremely small mass and solid deficit angle subject to the global monopole by means of the strong field limit issue. We obtain the angular position and magnification of the relativistic images and show that they relate to the global monopole parameter η. We discuss that with the increase of the parameter η, the minimum impact parameter u m and angular separation s increase and the relative magnification r decreases. We also find that s grows extremely as the increasing parameter η becomes large enough. The deflection angle will become larger when the parameter η grows. The effect from the solid deficit angle is the dependence of angular position, angular separation, relative magnification and deflection angle on the parameter η, which may offer a way to characterize some possible distinct signatures of the Schwarzschild black hole with a solid deficit angle associated with the global monopole.

  10. Ultrathin self-assembled anionic polymer membranes for superfast size-selective separation

    Science.gov (United States)

    Deng, Chao; Zhang, Qiu Gen; Han, Guang Lu; Gong, Yi; Zhu, Ai Mei; Liu, Qing Lin

    2013-10-01

    Nanoporous membranes with superior separation performance have become more crucial with increasing concerns in functional nanomaterials. Here novel ultrahigh permeable nanoporous membranes have been fabricated on macroporous supports by self-assembly of anionic polymer on copper hydroxide nanostrand templates in organic solution. This facile approach has a great potential for the fabrication of ultrathin anionic polymer membranes as a general method. The as-fabricated self-assembled membranes have a mean pore size of 5-12 nm and an adjustable thickness as low as 85 nm. They allow superfast permeation of water, and exhibit excellent size-selective separation properties and good fouling resistance for negatively-charged solutes during filtration. The 85 nm thick membrane has an ultrahigh water flux (3306 l m-2 h-1 bar-1) that is an order of magnitude larger than commercial membranes, and can highly efficiently separate 5 and 15 nm gold nanoparticles from their mixtures. The newly developed nanoporous membranes have a wide application in separation and purification of biomacromolecules and nanoparticles.Nanoporous membranes with superior separation performance have become more crucial with increasing concerns in functional nanomaterials. Here novel ultrahigh permeable nanoporous membranes have been fabricated on macroporous supports by self-assembly of anionic polymer on copper hydroxide nanostrand templates in organic solution. This facile approach has a great potential for the fabrication of ultrathin anionic polymer membranes as a general method. The as-fabricated self-assembled membranes have a mean pore size of 5-12 nm and an adjustable thickness as low as 85 nm. They allow superfast permeation of water, and exhibit excellent size-selective separation properties and good fouling resistance for negatively-charged solutes during filtration. The 85 nm thick membrane has an ultrahigh water flux (3306 l m-2 h-1 bar-1) that is an order of magnitude larger than

  11. Scaling laws for gas–liquid flow in swirl vane separators

    International Nuclear Information System (INIS)

    Liu, Li; Bai, Bofeng

    2016-01-01

    Highlights: • Model for swirl vane separator performance is established with similarity criteria. • Scaling laws are developed to correlate downscale test with prototype separator. • Effects of key similarity criteria on separation performance are studied. • The vital role of droplet size distribution on separation performance is discussed. - Abstract: Laboratory tests on gas–liquid flow in swirl vane separators are usually carried out to help establish an experimental database for separator design and performance improvement. Such model tests are generally performed in the reduced scale and not on the actual working conditions. Though great efficiency is often obtainable in the reduced model, the performance of the full-sized prototype usually cannot be well predicted. To design downscale model tests and apply the experimental results to predict the prototype, a general relationship to correlate them is required. In this paper, the relation of the similitude-criterion concerning the pressure loss is presented by using the dimensionless analysis, and mathematical models for critical droplet diameter, grade efficiency and overall separation efficiency are established by analyzing the features of the droplet trajectory in gas swirling flow field. The essential similarity criteria accounting for pressure loss and separation efficiency are obtained, respectively. On this basis, the scaling laws which enable a comparison between the reduced model and the full-sized prototype under similar conditions are also developed. It is found that the overall separation efficiency is significantly affected by the size distribution of the small droplets, especially when the mean diameter is smaller than the critical droplet diameter.

  12. Parametric study of separation and transition characteristics over an airfoil at low Reynolds numbers

    Energy Technology Data Exchange (ETDEWEB)

    Boutilier, Michael S.H.; Yarusevych, Serhiy [University of Waterloo, Waterloo, ON (Canada)

    2012-06-15

    Time-resolved surface pressure measurements are used to experimentally investigate characteristics of separation and transition over a NACA 0018 airfoil for the relatively wide range of chord Reynolds numbers from 50,000 to 250,000 and angles of attack from 0 to 21 . The results provide a comprehensive data set of characteristic parameters for separated shear layer development and reveal important dependencies of these quantities on flow conditions. Mean surface pressure measurements are used to explore the variation in separation bubble position, edge velocity in the separated shear layer, and lift coefficients with angle of attack and Reynolds number. Consistent with previous studies, the separation bubble is found to move upstream and decrease in length as the Reynolds number and angle of attack increase. Above a certain angle of attack, the proximity of the separation bubble to the location of the suction peak results in a reduced lift slope compared to that observed at lower angles. Simultaneous measurements of the time-varying component of surface pressure at various spatial locations on the model are used to estimate the frequency of shear layer instability, maximum root-mean-square (RMS) surface pressure, spatial amplification rates of RMS surface pressure, and convection speeds of the pressure fluctuations in the separation bubble. A power-law correlation between the shear layer instability frequency and Reynolds number is shown to provide an order of magnitude estimate of the central frequency of disturbance amplification for various airfoil geometries at low Reynolds numbers. Maximum RMS surface pressures are found to agree with values measured in separation bubbles over geometries other than airfoils, when normalized by the dynamic pressure based on edge velocity. Spatial amplification rates in the separation bubble increase with both Reynolds number and angle of attack, causing the accompanying decrease in separation bubble length. Values of the

  13. Actinide separation chemistry in nuclear waste streams and materials

    International Nuclear Information System (INIS)

    1997-12-01

    The separation of actinide elements from various waste materials, produced either in nuclear fuel cycles or in past nuclear weapons production, represents a significant issue facing developed countries. Improvements in the efficiencies of the separation processes can be expected to occur as a result of better knowledge of the elements in these complex matrices. The Nuclear Science Committee of the OECD/NEA has established a task force of experts in actinide separation chemistry to review current and developing separation techniques and chemical processes. The report consist of eight chapters. In Chapter 1 the importance of actinide separation chemistry in the fields of waste management and its background are summarized.In Chapter 2 the types of waste streams are classified according to their relative importance, by physical form and by source of actinides. The basic data of actinide chemical thermodynamics, such as oxidation states, hydrolysis, complexation, sorption, Gibbs energies of formation, and volatility, were collected and are presented in Chapter 3. Actinide analyses related to separation processes are also mentioned in this chapter. The state of the art of actinide separation chemistry is classified in three groups, including hydrometallurgy, pyrochemical process and process based on fields, and is described in Chapter 4 along with the relationship of kinetics to separations. In Chapter 5 basic chemistry research needs and the inherent limitation on separation processes are discussed. Prioritization of research and development is discussed in Chapter 6 in the context of several attributes of waste management problems. These attributes include: mass or volume of waste; concentration of the actinide in the waste; expected difficulty of treating the wastes; short-term hazard of the waste; long-term hazard of the waste; projected cost of treatment; amount of secondary waste. Based on the priority, recommendations were made for the direction of future research

  14. Actinide separation chemistry in nuclear waste streams and materials

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-01

    The separation of actinide elements from various waste materials, produced either in nuclear fuel cycles or in past nuclear weapons production, represents a significant issue facing developed countries. Improvements in the efficiencies of the separation processes can be expected to occur as a result of better knowledge of the elements in these complex matrices. The Nuclear Science Committee of the OECD/NEA has established a task force of experts in actinide separation chemistry to review current and developing separation techniques and chemical processes. The report consist of eight chapters. In Chapter 1 the importance of actinide separation chemistry in the fields of waste management and its background are summarized.In Chapter 2 the types of waste streams are classified according to their relative importance, by physical form and by source of actinides. The basic data of actinide chemical thermodynamics, such as oxidation states, hydrolysis, complexation, sorption, Gibbs energies of formation, and volatility, were collected and are presented in Chapter 3. Actinide analyses related to separation processes are also mentioned in this chapter. The state of the art of actinide separation chemistry is classified in three groups, including hydrometallurgy, pyrochemical process and process based on fields, and is described in Chapter 4 along with the relationship of kinetics to separations. In Chapter 5 basic chemistry research needs and the inherent limitation on separation processes are discussed. Prioritization of research and development is discussed in Chapter 6 in the context of several attributes of waste management problems. These attributes include: mass or volume of waste; concentration of the actinide in the waste; expected difficulty of treating the wastes; short-term hazard of the waste; long-term hazard of the waste; projected cost of treatment; amount of secondary waste. Based on the priority, recommendations were made for the direction of future research

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-05-01

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

  16. Fourier phase analysis on equilibrium gated radionuclide ventriculography: range of phase spread and cut-off limits in normal individuals

    International Nuclear Information System (INIS)

    Ramaiah, Vijayaraghavan L.; Harish, B.; Sunil, H.V.; Selvakumar, Job; Ravi Kishore, A.G.; Nair, Gopinathan

    2011-01-01

    To define the range of phase spread on equilibrium gated radionuclide ventriculography (ERNV) in normal individuals and derive the cut-off limit for the parameters to detect cardiac dyssynchrony. ERNV was carried out in 30 individuals (age 53±23 years, 25 males and 5 females) who had no history of cardiovascular disease. They all had normal left ventricular ejection fraction (LVEF 55-70%) as determined by echocardiography, were in sinus rhythm, with normal QRS duration (≤120 msec) and normal coronary angiography. First harmonic phase analysis was performed on scintigraphic data acquired in best septal view. Left and right ventricular standard deviation (LVSD and RVSD, respectively) and interventricular mechanical delay (IVMD), the absolute difference of mean phase angles of right and left ventricle, were computed and expressed in milliseconds. Mean + 3 standard deviation (SD) was used to derive the cut-off limits. Average LVEF and duration of cardiac cycle in the study group were 62.5%±5.44% and 868.9±114.5 msec, respectively. The observations of LVSD, RVSD and right and left ventricular mean phase angles were shown to be normally distributed by Shapiro-Wilk test. Cut-off limits for LVSD, RVSD and IVMD were calculated to be 80 msec, 85 msec and 75 msec, respectively. Fourier phase analysis on ERNV is an effective tool for the evaluation of synchronicity of cardiac contraction. The cut-off limits of parameters of dyssynchrony can be used to separate heart failure patients with cardiac dyssynchrony from those without. ERNV can be used to select patients for cardiac resynchronization therapy. (author)

  17. X-RAYS SEPARATOR: FORWARD STEP IN TECHNOLOGY OF OPTICAL SEPARATION

    Directory of Open Access Journals (Sweden)

    N. N. Potrakhov

    2017-01-01

    Full Text Available Presently the X-ray separation is used not only for research program, but it is also elaborated and applied for different sectors of economy. The seeds as biological objects that possess the complicated microstructure are very difficult to be exanimated by x-ray technology. The application of x-rays and further elaboration of optical  separators, principle  of action, basic specifications, way of their use and their efficiency was shown in the article. The x-ray separator may distinguish all hidden seed defects as it was described by a programmer, where owing to the use of the optical separating block in visual range it is possible to add some more details as a shape, brightness and a color of object surface being exanimated. The elaboration of such separation equipment is scientifically hard work requiring time and expenses. Last year researchers of ‘LETI’ developed the working model of industrial x-ray separator for examination of grains and nuts in different crops. This model was made on the basis of photoseparator F-5 manufactured at OAO ‘Voronezhselmash’. The instrument state and its mechanism operation are highlighted on monitor. In the regime of processing (separation and examination of each controlled batch, the passport is produced with  following  information on identification  code,  time of material receiving, time of test passed, number of grains or seeds tested. The code of receiver of material is given to each of established characteristics when working the regime of separation, determination of number of objects with characteristics tested and number of unidentified objects. The application of x-ray separators constructed on the basis of photoseparator F-5 enables to carry out the complex estimation on seed quality and separation in only instrument with the development of electronic protocol with many characteristics.

  18. Limiting law excess sum rule for polyelectrolytes.

    Science.gov (United States)

    Landy, Jonathan; Lee, YongJin; Jho, YongSeok

    2013-11-01

    We revisit the mean-field limiting law screening excess sum rule that holds for rodlike polyelectrolytes. We present an efficient derivation of this law that clarifies its region of applicability: The law holds in the limit of small polymer radius, measured relative to the Debye screening length. From the limiting law, we determine the individual ion excess values for single-salt electrolytes. We also consider the mean-field excess sum away from the limiting region, and we relate this quantity to the osmotic pressure of a dilute polyelectrolyte solution. Finally, we consider numerical simulations of many-body polymer-electrolyte solutions. We conclude that the limiting law often accurately describes the screening of physical charged polymers of interest, such as extended DNA.

  19. Quality assurance of nuclear analytical techniques based on Bayesian characteristic limits

    International Nuclear Information System (INIS)

    Michel, R.

    2000-01-01

    Based on Bayesian statistics, characteristic limits such as decision threshold, detection limit and confidence limits can be calculated taking into account all sources of experimental uncertainties. This approach separates the complete evaluation of a measurement according to the ISO Guide to the Expression of Uncertainty in Measurement from the determination of the characteristic limits. Using the principle of maximum entropy the characteristic limits are determined from the complete standard uncertainty of the measurand. (author)

  20. Americium-curium separation by means of selective extraction of hexavalent americium using a centrifugal contactor

    International Nuclear Information System (INIS)

    Musikas, C.; Germain, M.; Bathellier, A.

    1979-01-01

    This paper deals with Am (VI) - Cm (III) separation in nitrate media. The kinetics of oxidation of Am (III) by sodium persulfate in the presence of Ag + ions were reinvestigated by studying the effect of additions of small amounts of reagents which do not drastically change the distribution coefficients of Am (VI) or Cm (III) ions. Organo phosphorus solvents were selected because they are radiation resistant, possess weak reductant properties and that their affinity for hexavalent ion is high. The operating procedure was selected by consideration of the results of the two previous investigations. This can be done by using a centrifugal contactor enabling in to set organic-aqueous phase contact time in accordance with the kinetics of extraction of Am (VI), oxidation of Am (III) in aqueous phase, and reduction of Am (VI) in organic phase

  1. Separation of cancer cells using vortical microfluidic flows.

    Science.gov (United States)

    Haddadi, Hamed; Naghsh-Nilchi, Hamed; Di Carlo, Dino

    2018-01-01

    Label-free separation of viable cancer cells using vortical microfluidic flows has been introduced as a feasible cell collection method in oncological studies. Besides the clinical importance, the physics of particle interactions with the vortex that forms in a wall-confined geometry of a microchannel is a relatively new area of fluid dynamics. In our previous work [Haddadi and Di Carlo, J. Fluid. Mech. 811 , 436-467 (2017)], we have introduced distinct aspects of inertial flow of dilute suspensions over cavities in a microchannel such as breakdown of the separatrix and formation of stable limit cycle orbits for finite size polystyrene particles. In this work, we extend our experiments to address the engineering-physics of cancer cell entrapment in microfluidic cavities. We begin by studying the effects of the channel width and device height on the morphology of the vortex, which has not been discussed in our previous work. The stable limit cycle orbits of finite size cancer cells are then presented. We demonstrate effects of the separatrix breakdown and the limit cycle formation on the operation of the cancer cell separation platform. By studying the flow of dilute cell suspensions over the cavities, we further develop the notion of the cavity capacity and the relative rate of cell accumulation as optimization criteria which connect the device geometry with the flow. Finally, we discuss the proper placement of multiple cavities inside a microchannel for improved cell entrapment.

  2. Sex separation strategies: past experience and new approaches

    Directory of Open Access Journals (Sweden)

    Malcolm Colin A

    2009-11-01

    Full Text Available Abstract The success of the sterile insect technique (SIT and other genetic strategies designed to eliminate large populations of insects relies on the efficient inundative releases of competitive, sterile males into the natural habitat of the target species. As released sterile females do not contribute to the sterility in the field population, systems for the efficient mass production and separation of males from females are needed. For vector species like mosquitoes, in which only females bite and transmit diseases, the thorough removal of females before release while leaving males competent to mate is a stringent prerequisite. Biological, genetic and transgenic approaches have been developed that permit efficient male-female separation for some species considered for SIT. However, most sex separation methods have drawbacks and many of these methods are not directly transferable to mosquitoes. Unlike genetic and transgenic systems, biological methods that rely on sexually dimorphic characters, such as size or development rate, are subject to natural variation, requiring regular adjustment and re-calibration of the sorting systems used. The yield can be improved with the optimization of rearing, but the scale of mass production places practical limits on what is achievable, resulting in a poor rearing to output ratio. High throughput separation is best achieved with scalable genetic or transgenic approaches.

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

    Science.gov (United States)

    Thurai, Merhala; Gatlin, Patrick; Williams, Christopher

    2014-01-01

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

  4. Calculating and reporting effect sizes on scientific papers (1: p < 0.05 limitations in the analysis of mean differences of two groups

    Directory of Open Access Journals (Sweden)

    Helena Espirito Santo

    2015-02-01

    Since p-values from the results of the statistical tests do not indicate the magnitude or importance of a difference, then effect sizes (ES should reported. In fact, ES give meaning to statistical tests; emphasize the power of statistical tests; reduce the risk of interpret mere sampling variation as real relationship; can increase the reporting of “non-significant"results, and allow the accumulation of knowledge from several studies using meta-analysis. Thus, the objectives of this paper are to present the limits of the significance level; describe the foundations of presentation of ES of statistical tests to analyze differences between two groups; present the formulas to calculate directly ES, providing examples of our own previous studies; show how to calculate confidence intervals; provide the conversion formulas for the review of the literature; indicate how to interpret the ES; and show that, although interpretable, the meaning (small, medium or large effect for an arbitrary metric could be inaccurate, requiring that interpretation should be made in the context of the research area and in the context of real world variables.

  5. Fractional Diffusion Limit for Collisional Kinetic Equations

    KAUST Repository

    Mellet, Antoine

    2010-08-20

    This paper is devoted to diffusion limits of linear Boltzmann equations. When the equilibrium distribution function is a Maxwellian distribution, it is well known that for an appropriate time scale, the small mean free path limit gives rise to a diffusion equation. In this paper, we consider situations in which the equilibrium distribution function is a heavy-tailed distribution with infinite variance. We then show that for an appropriate time scale, the small mean free path limit gives rise to a fractional diffusion equation. © 2010 Springer-Verlag.

  6. Metal oxide membranes for gas separation

    Science.gov (United States)

    Anderson, Marc A.; Webster, Elizabeth T.; Xu, Qunyin

    1994-01-01

    A method for permformation of a microporous ceramic membrane onto a porous support includes placing a colloidal suspension of metal oxide particles on one side of the porous support and exposing the other side of the porous support to a drying stream of gas or a reactive gas stream so that the particles are deposited on the drying side of the support as a gel. The gel so deposited can be sintered to form a supported ceramic membrane having mean pore sizes less than 30 Angstroms and useful for ultrafiltration, reverse osmosis, or gas separation.

  7. Acoustofluidic bacteria separation

    International Nuclear Information System (INIS)

    Li, Sixing; Huang, Tony Jun; Ma, Fen; Zeng, Xiangqun; Bachman, Hunter; Cameron, Craig E

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device. (paper)

  8. Acoustofluidic bacteria separation

    Science.gov (United States)

    Li, Sixing; Ma, Fen; Bachman, Hunter; Cameron, Craig E.; Zeng, Xiangqun; Huang, Tony Jun

    2017-01-01

    Bacterial separation from human blood samples can help with the identification of pathogenic bacteria for sepsis diagnosis. In this work, we report an acoustofluidic device for label-free bacterial separation from human blood samples. In particular, we exploit the acoustic radiation force generated from a tilted-angle standing surface acoustic wave (taSSAW) field to separate Escherichia coli from human blood cells based on their size difference. Flow cytometry analysis of the E. coli separated from red blood cells shows a purity of more than 96%. Moreover, the label-free electrochemical detection of the separated E. coli displays reduced non-specific signals due to the removal of blood cells. Our acoustofluidic bacterial separation platform has advantages such as label-free separation, high biocompatibility, flexibility, low cost, miniaturization, automation, and ease of in-line integration. The platform can be incorporated with an on-chip sensor to realize a point-of-care sepsis diagnostic device.

  9. Isotopic separation

    International Nuclear Information System (INIS)

    Castle, P.M.

    1979-01-01

    This invention relates to molecular and atomic isotope separation and is particularly applicable to the separation of 235 U from other uranium isotopes including 238 U. In the method described a desired isotope is separated mechanically from an atomic or molecular beam formed from an isotope mixture utilising the isotropic recoil momenta resulting from selective excitation of the desired isotope species by radiation, followed by ionization or dissociation by radiation or electron attachment. By forming a matrix of UF 6 molecules in HBr molecules so as to collapse the V 3 vibrational mode of the UF 6 molecule the 235 UF 6 molecules are selectively excited to promote reduction of UF 6 molecules containing 235 U and facilitate separation. (UK)

  10. Rapid and Convenient Separation of Chitooligosaccharides by Ion-Exchange Chromatography

    Science.gov (United States)

    Wu, Yuxiao; Lu, Wei-Peng; Wang, Jianing; Gao, Yunhua; Guo, Yanchuan

    2017-12-01

    Pervious methods for separation of highly purified chitooligosaccharides was time-consuming and labor-intensive, which limited the large-scale production. This study developed a convenient ion-exchange chromatography using the ÄKTA™ avant 150 chromatographic system. Five fractions were automatically collected under detecting the absorption at 210 nm. The fractions were analyzed by high-performance liquid chromatography. It proved that they primarily comprised chitobiose, chitotriose, chitotetraose, chitopentaose, and chitohexaose, respectively, with chromatographic purities over 90%. The separation process was rapid, convenient and could be monitored on-line, which would be benefit for the mass production of chitooligosaccharides.

  11. Passive Flap Actuation by Reversing Flow in Laminar Boundary Layer Separation

    Science.gov (United States)

    Parsons, Chase; Lang, Amy; Santos, Leo; Bonacci, Andrew

    2017-11-01

    Reducing the flow separation is of great interest in the field of fluid mechanics in order to reduce drag and improve the overall efficiency of aircraft. This project seeks to investigate passive flow control using shark inspired microflaps in laminar boundary layer separation. This study aims to show that whether a flow is laminar or turbulent, laminar and 2D or turbulent and 3D, microflaps actuated by reversing flow is a robust means of controlling flow separation. In order to generate a controlled adverse pressure gradient, a rotating cylinder induces separation at a chosen location on a flat plate boundary layer with Re above 10000. Within this thick boundary layer, digital particle image velocimetry is used to map the flow. This research can be used in the future to better understand the nature of the bristling shark scales and its ability to passively control separation. Results show that microflaps successfully actuated due to backflow and that this altered the formation of flow separation. I would like to thank the NSF for REU Grant EEC 1659710 and the Army Research Office for funding this project.

  12. Identification of new proton-rich rare earth nuclei by means of the coupled system helium jet-isotope separator of SARA

    International Nuclear Information System (INIS)

    Ollivier, T.

    1986-01-01

    In order to study new exotic nuclei far from stability we built a fast separation system by coupling a helium jet with the medium-current source of the mass separator. First the tests were made in Lyon and then the system used on line with the heavy ion accelerator SARA, in Grenoble. We obtained efficiency greater than 1% for each element and a better chemical independence. This allowed us to perform experiments on rare-earth region near N=82, with fusion-evaporation reactions after an investigation of various ranges of beam energies. The first results allow to identify two new isotopes, 143 Tb (12s) and 138 Eu (12s). The decay schemes obtained are analysed in the frame of existing models [fr

  13. Mothers' Parenting Stress and Adolescents' Emotional Separation: The Role of Youngsters' Self Orientation

    Science.gov (United States)

    Liga, Francesca; Ingoglia, Sonia; Lo Cricchio, Maria Grazia; Lo Coco, Alida

    2015-01-01

    The study examined the association among mothers' parenting stress, adolescents' emotional separation and self-orientation toward connectedness. Participants were 194 Italian adolescents, aged from 15 to 19 years (mean age = 17.39, SD = 1.18), and their mothers, aged from 33 to 64 years (mean age = 44.35, SD = 5.40). General findings showed that…

  14. Economic Meaning of the Concept of “Non-Financial Reporting”

    OpenAIRE

    Bezverkhiy

    2017-01-01

    The issue related with interpretation of the economic meaning of “non-financial reporting” becomes vital in view of harmonizing the Ukrainian legal acts with EU standards, including ones on accounting. In practice, much confusion still occurs: non-financial reporting may either be seen as separated reporting, or as one identical to integrated reporting, or as an integrated reporting component. The aim of the study is to clarify the economic meaning of the concept of “non-financial reporting. ...

  15. Feasibility analysis of gas turbine inlet air cooling by means of liquid nitrogen evaporation for IGCC power augmentation

    International Nuclear Information System (INIS)

    Morini, Mirko; Pinelli, Michele; Spina, Pier Ruggero; Vaccari, Anna; Venturini, Mauro

    2015-01-01

    Integrated Gasification Combined Cycles (IGCC) are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as the oxidant, an Air Separation Unit (ASU) is also part of the plant. In this paper, a system for power augmentation in IGCC is evaluated. The system is based on gas turbine inlet air cooling by means of liquid nitrogen spray. In fact, nitrogen is a product of the ASU, but is not always exploited. In the proposed plant, the nitrogen is first liquefied to be used for inlet air cooling or stored for later use. This system is not characterized by the limits of water evaporative cooling systems (the lower temperature is limited by air saturation) and refrigeration cooling (the effectiveness is limited by the pressure drop in the heat exchanger). A thermodynamic model of the system is built by using a commercial code for energy conversion system simulation. A sensitivity analysis on the main parameters is presented. Finally the model is used to study the capabilities of the system by imposing the real temperature profiles of different sites for a whole year and by comparing to traditional inlet air cooling strategies. - Highlights: • Gas turbine inlet air cooling by means of liquid nitrogen spray. • Humidity condensation may form a fog which provides further power augmentation. • High peak and off peak electric energy price ratios make the system profitable

  16. Radioactive decays at limits of nuclear stability

    DEFF Research Database (Denmark)

    Pfützner, M.; Karny, M.; Grigorenko, L. V.

    2012-01-01

    , and their relative probabilities. When approaching limits of nuclear stability, new decay modes set in. First, beta decays are accompanied by emission of nucleons from highly excited states of daughter nuclei. Second, when the nucleon separation energy becomes negative, nucleons start being emitted from the ground...

  17. XTR detection by means of 20 μm resolution drift chamber

    International Nuclear Information System (INIS)

    Baskakov, V.I.; Dolgoshein, B.A.; Lebedenko, V.N.

    1977-01-01

    The possibility to separate spatially the ionization losses of a relativistic charged particle and XTR quanta generated by the same particle in the laminated medium in detector was investigated. A double electroluminescent drift chamber filled with xenon at 10 atm pressure was constructed for this purpose. A detailed examination of the chamber characteristics was carried out on 3.5 GeV energy electron beam. The obtained results demonstrated the possibility to separate XTR and particle ionization spatially by means of the described method

  18. Passive fault current limiting device

    Science.gov (United States)

    Evans, Daniel J.; Cha, Yung S.

    1999-01-01

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

  19. The capacity limitations of orientation summary statistics

    Science.gov (United States)

    Attarha, Mouna; Moore, Cathleen M.

    2015-01-01

    The simultaneous–sequential method was used to test the processing capacity of establishing mean orientation summaries. Four clusters of oriented Gabor patches were presented in the peripheral visual field. One of the clusters had a mean orientation that was tilted either left or right while the mean orientations of the other three clusters were roughly vertical. All four clusters were presented at the same time in the simultaneous condition whereas the clusters appeared in temporal subsets of two in the sequential condition. Performance was lower when the means of all four clusters had to be processed concurrently than when only two had to be processed in the same amount of time. The advantage for establishing fewer summaries at a given time indicates that the processing of mean orientation engages limited-capacity processes (Experiment 1). This limitation cannot be attributed to crowding, low target-distractor discriminability, or a limited-capacity comparison process (Experiments 2 and 3). In contrast to the limitations of establishing multiple summary representations, establishing a single summary representation unfolds without interference (Experiment 4). When interpreted in the context of recent work on the capacity of summary statistics, these findings encourage reevaluation of the view that early visual perception consists of summary statistic representations that unfold independently across multiple areas of the visual field. PMID:25810160

  20. Separation of contact in a sliding system with frictionally excited thermoelastic instability

    Directory of Open Access Journals (Sweden)

    Voldřich J.

    2007-10-01

    Full Text Available The first phase of the thermoelastic instability, which is characterized by a full contact regime, can be modelled using Fourier decomposition and application of an analytical description. However, in case of further increase of instability, a separation of the contact occurs which is more difficult to cover by mathematical means. The contribution deals with numerical simulations of the separation. The problems are topical in connection with the disk brakes design, should we give an example.

  1. Blind Source Separation For Ion Mobility Spectra

    International Nuclear Information System (INIS)

    Marco, S.; Pomareda, V.; Pardo, A.; Kessler, M.; Goebel, J.; Mueller, G.

    2009-01-01

    Miniaturization is a powerful trend for smart chemical instrumentation in a diversity of applications. It is know that miniaturization in IMS leads to a degradation of the system characteristics. For the present work, we are interested in signal processing solutions to mitigate limitations introduced by limited drift tube length that basically involve a loss of chemical selectivity. While blind source separation techniques (BSS) are popular in other domains, their application for smart chemical instrumentation is limited. However, in some conditions, basically linearity, BSS may fully recover the concentration time evolution and the pure spectra with few underlying hypothesis. This is extremely helpful in conditions where non-expected chemical interferents may appear, or unwanted perturbations may pollute the spectra. SIMPLISMA has been advocated by Harrington et al. in several papers. However, more modern methods of BSS for bilinear decomposition with the restriction of positiveness have appeared in the last decade. In order to explore and compare the performances of those methods a series of experiments were performed.

  2. Reversed-Phase UHPLC Enantiomeric Separation of Rasagiline Salts Using a Chiralpak® AGP Column

    Directory of Open Access Journals (Sweden)

    Nagarajan Balaji

    2017-07-01

    Full Text Available We report the first rapid ultra-high performance liquid chromatographic (UHPLC enantiomeric reversed-phase separation of rasagiline mesylate and its tartrate salts using a Chiralpak® AGP column (50 mm × 2.1 mm, 5 μm as a stationary phase. This method was developed as an alternative to the usage of previously reported normal-phase chiral LC columns for isomer separation. Our method is based on an isocratic approach using a mixture of ammonium acetate and isopropyl alcohol (90:10, v/v as the mobile phase (0.6 mL/min flow rate. The detection limit (at a detection wavelength of 210 nm and quantification limit for the rasagiline enantiomers were 0.06 and 0.2 μg/mL, respectively. This method is compatible with the UHPLC-MS technique. The successful separation of rasagiline and its enantiomer was confirmed by determining the corresponding specific optical rotation values. Our method will be applicable for detecting rasagiline enantiomers during the control of manufacturing processes, and for use in rapid analysis for quality control in pharmaceutical industry to obtain optically pure pharmaceutical substances. This method was validated in terms of its precision, limit of detection, limit of quantification, linearity, accuracy, robustness, ruggedness, specificity, forced degradation, and solution stability, according to International Council on Harmonization Validation Guidelines Q2 (R1.

  3. Sb(III) and Sb(V) separation and analytical speciation by a continuous tandem on-line separation device in connection with inductively coupled plasma atomic emission spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Menendez Garcia, A. [Oviedo Univ. (Spain). Dept. of Phys. and Anal. Chem.; Perez Rodriguez, M.C. [Oviedo Univ. (Spain). Dept. of Phys. and Anal. Chem.; Sanchez Uria, J.F. [Oviedo Univ. (Spain). Dept. of Phys. and Anal. Chem.; Sanz-Medel, A. [Oviedo Univ. (Spain). Dept. of Phys. and Anal. Chem.

    1995-09-01

    A sensitive, precise and automated non-chromatographic method for Sb(III) and Sb(V) analytical speciation based on a continuous tandem on-line separation device in connection with inductively coupled plasma-atomic emission (ICP-AES) detection is proposed. Two on-line successive separation steps are included into this method: a continuous liquid-liquid extraction of Sb(III) with ammonium pyrrolidine dithiocarbamate (APDC) into methylisobuthylketone (MIBK), followed by direct stibine generation from the organic phase. Both separation steps are carried out in a continuous mode and on-line with the ICP-AES detector. Optimization of experimental conditions for the tandem separation and ICP-AES detection are investigated in detail. Detection limits for Sb(III) were 3 ng.mL{sup -1} and for Sb(V) 8 ng.mL{sup -1}. Precisions observed are in the range {+-} 5%. The proposed methodology has been applied to Sb(III) and Sb(V) speciation in sea-water samples. (orig.)

  4. A separator

    Energy Technology Data Exchange (ETDEWEB)

    Prokopyuk, S.G.; Dyachenko, A.Ye.; Mukhametov, M.N.; Prokopov, O.I.

    1982-01-01

    A separator is proposed which contains separating slanted plates and baffle plates installed at a distance to them at an acute angle to them. To increase the effectiveness of separating a gas and liquid stream and the throughput through reducing the secondary carry away of the liquid drops and to reduce the hydraulic resistance, as well, openings are made in the plates. The horizontal projections of each opening from the lower and upper surfaces of the plate do not overlap each other.

  5. Institute for separation chemistry of Marcoule I.C.S.M; Institut de chimie separative de Marcoule I.C.S.M

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Institute for Separation Chemistry was created in March 2007, and the building including laboratory and offices will be opened to scientists and technicians the middle of 2008. Since resources in Uranium are scarce and wastes related to nuclear energy production are potentially dangerous, the chemistry associated to nuclear energy production always followed the principles of green chemistry: close the life-cycle of material and fuel, minimize wastes and ascertain the acceptability by a society via knowledge of chemistry and physical chemistry involved in processes. The Institute is devoted to chemistry at the service of the nuclear energy of the future, seen as an actor for sustainable development compatible with limited resources and chemical preservation of the atmosphere. Progresses in fundamental research, based on publication and education of students, engineers and young scientists, will be focused along seven identified directions, devoted to scattering and diffraction, microscopies and mainly mesoscopic modelling. The goals of the teams are described in this booklet, describing activities of the 28 scientists since two years. Separation chemistry, a branch of physical chemistry, is a key actor in 'green chemistry'. Nano-science and physical chemistry, at the roots of modern chemistry considering also non-covalent and long-range interactions, need to be included along the 'tools' involved in new processes. Three axis of research will be privileged: initial steps of separation, via dissolution by sono-chemical means, ion separation via colloids and complex fluids, and maintaining the separation between species involving self-repairing nano-materials, once the evolution of the interface fed from the evolving interface has been modelled. Eleven permanent staff scientists are already active since a few months on average at ICSM at the date of this report (5 CEA, 2 Universities and 4 CNRS). Teaching, scientific animation, summer schools and the common laboratory

  6. Effect of geometric parameters of liquid-gas separator units on phase separation performance

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Songping; Chen, Xueqing; Chen, Ying [Guangdong University of Technology, Seoul (China); Yang, Zhen [Tsinghua University, Beijing (China)

    2015-07-15

    Five liquid-gas separator units were designed and constructed based on a new concept of a validated high-performance condenser. Each separator unit consists of two united T-junctions and an apertured baffle. The separator units have different header diameters or different baffles with different diameters of the liquid-gas separation hole. The phase separation characteristics of the units were investigated at inlet air superficial velocities from 1.0m/s to 33.0m/s and water superficial velocities from 0.0015 m/s to 0..50 m/s. The experimental results showed that the liquid height, liquid flow rate through the separation hole, and liquid separation efficiency increased with increased header diameter and decreased diameter of the separation hole. The geometric structures of the separator units affected the phase separation characteristics by influencing the liquid height in the header and the liquid flow rate through the separation hole.

  7. Phase separation in Sr doped BiMnO3

    International Nuclear Information System (INIS)

    Li Guan-Nan; Gao Qing-Qing; Luo Jun; Liu Guang-Yao; Liang Jing-Kui; Rao Guang-Hui; Huang Qing-Zhen; Li Jing-Bo

    2014-01-01

    Phase separation in Sr doped BiMnO 3 (Bi 1−x Sr x MnO 3 , x = 0.4−0.6) was studied by means of temperature-dependent high-resolution neutron powder diffraction (NPD), high resolution X-ray powder diffraction (XRD), and physical property measurements. All the experiments indicate that a phase separation occurs at the temperature coinciding with the reported charge ordering temperature (T CO ) in the literature. Below the reported T CO , both the phases resulting from the phase separation crystallize in the orthorhombically distorted perovskite structure with space group Imma. At lower temperature, these two phases order in the CE-type antiferromagnetic structure and the A-type antiferromagnetic structure, respectively. However, a scrutiny of the high-resolution NPD and XRD data at different temperatures and the electron diffraction experiment at 300 K did not manifest any evidence of a long-range charge ordering (CO) in our investigated samples, suggesting that the anomalies of physical properties such as magnetization, electric transport, and lattice parameters at the T CO might be caused by the phase separation rather than by a CO transition

  8. Empirical Study on Factors Influencing Residents' Behavior of Separating Household Wastes at Source

    Institute of Scientific and Technical Information of China (English)

    Qu Ying; Zhu Qinghua; Murray Haight

    2007-01-01

    Source separation is the basic premise for making effective use of household wastes. In eight cities of China, however, several pilot projects of source separation finally failed because of the poor participation rate of residents. In order to solve this problem, identifying those factors that influence residents' behavior of source separation becomes crucial. By means of questionnaire survey, we conducted descriptive analysis and exploratory factor analysis. The results show that trouble-feeling, moral notion, environment protection, public education, environment value and knowledge deficiency are the main factors that play an important role for residents in deciding to separate their household wastes. Also, according to the contribution percentage of the six main factors to the total behavior of source separation, their influencing power is analyzed, which will provide suggestions on household waste management for policy makers and decision makers in China.

  9. Separating rings detection in fuel channels of Embalse NPP

    International Nuclear Information System (INIS)

    Obrutsky, L.S.; Otero, P.A.; Schmidt, O.A.

    1988-01-01

    The design specifications of Embalse Nuclear Power Plants (CANDU Type Reactor 600Mw) define the positions to be taken by 4 separating rings of the fuel channels. Experience has demonstrated the displacement possibility of the above mentioned rings. It means a risk of contact between pressure tube and calandria tube. In order to determine the position of separating rings, an inspection system based on Eddy Currents technique was developed by CNEA personnel. Detection is performed through two special probes operating according the ''emitter-receiver'' principle. Obtained signals and its relative position are recorded in a video tape and registered in paper. The probe is telecommanded by an automatic equipment. In this paper the construction and calibration of the detection equipment is described, as well as the propulsion. Final results are also outlined in the inspection carried out in November 1986 when an effective displacement of separating rings was verified from its design position in most of the inspected tubes

  10. Isolation of radioactive strontium from natural samples. Separation of strontium from alkaline and alkaline earth elements by means of mixed solvent anion exchange

    International Nuclear Information System (INIS)

    Grahek, Z.; Kosutic, K.; Lulic, S.; Kvastek, K.; Eskinja, I.

    1999-01-01

    This paper presents the results of studies which led to the procedures for the chromatographic separation of radioactive strontium from alkaline, earth-alkaline and other elements in natural samples, on columns filled with strong base anion exchangers using alcoholic solutions of nitric acid as eluents. It has been shown that potassium, caesium, calcium, barium, yttrium and strontium can be adsorbed on strong base anion exchangers of the Dowex and Amberlite type, which contain the quaternary ammonium group with nitrate as counter-ion, from solutions of nitric acid in alcohol. Adsorption strength increases in the order methanol 3 in methanol, while they are adsorbed from ethanol and propanol. The adsorption strength is influenced by the polarity of alcohol, by the concentration of nitrate and by pH. The strength with which strontium adsorbs on the exchangers increases in the interval from 0 to 0.25M NH 4 NO 3 in methanol, after which it starts to decrease. Strontium adsorbs to the exchangers from the alcoholic solution of ammonium nitrate twice as strongly as from the alcoholic solution of nitric acid, while a fraction of water in pure alcohol exceeding 10% prevents adsorption. In the mixture of alcohol and nitric acid, the adsorption strength for calcium and strontium increases with the increase of the volume fraction of alcohol with a lower dielectric constant. The rate and strength of adsorption of ions on the exchanger also increase in the series 0.25M HNO 3 in methanol 3 in ethanol 3 in 1-propanol for each individual ion, as well as in the Ca 3 in methanol, 0.25M HNO 3 in ethanol and 0.25M HNO 3 in propanol. Separation is also possible from alcohol mixtures. Strontium separation is most difficult from calcium, while the efficiency of separation increases with a decrease of the polarity of the used alcohol or alcohol mixture. The first group elements of the periodic table are not separated from each other in this way, while the elements of the second group are

  11. Underdetermined Blind Source Separation in Echoic Environments Using DESPRIT

    Directory of Open Access Journals (Sweden)

    Melia Thomas

    2007-01-01

    Full Text Available The DUET blind source separation algorithm can demix an arbitrary number of speech signals using anechoic mixtures of the signals. DUET however is limited in that it relies upon source signals which are mixed in an anechoic environment and which are sufficiently sparse such that it is assumed that only one source is active at a given time frequency point. The DUET-ESPRIT (DESPRIT blind source separation algorithm extends DUET to situations where sparsely echoic mixtures of an arbitrary number of sources overlap in time frequency. This paper outlines the development of the DESPRIT method and demonstrates its properties through various experiments conducted on synthetic and real world mixtures.

  12. Microfluidic emulsion separation-simultaneous separation and sensing by multilayer nanofilm structures

    Energy Technology Data Exchange (ETDEWEB)

    Uhlmann, P; Truman, P; Stamm, M [Leibniz-Institut fuer Polymerforschung Dresden e V, Hohe Strasse 6, 01069 Dresden (Germany); Varnik, F; Zikos, G [Ruhr Universitaet Bochum, Stiepeler Strasse 129, 44801 Bochum (Germany); Moulin, J-F; Mueller-Buschbaum, P, E-mail: uhlmannp@ipfdd.de [Technische Universitaet Muenchen, Physik-Department, LS E13, James-Franck-Strasse 1, 85748 Garching (Germany)

    2011-05-11

    Emulsion separation is of high relevance for filtration applications, liquid-liquid-partitioning of biomolecules like proteins and recovery of products from droplet microreactors. Selective interaction of various components of an emulsion with substrates is used to design microfluidic flow chambers for efficient separation of emulsions into their individual components. Our lab-on-a-chip device consists of an emulsion separation cell with an integrated silicon sensor chip, the latter allowing the detection of liquid motion via the field-effect signal. Thus, within our lab-on-a-chip device, emulsions can be separated while the separation process is monitored simultaneously. For emulsion separation a surface energy step gradient, namely a sharp interface between the hydrophobic and hydrophilic parts of the separation chamber, is used. The key component of the lab-on-a-chip system is a multilayer and multifunctional nanofilm structure which not only provides the surface energy step gradient for emulsion separation but also constitutes the functional parts of the field-effect transistors. The proof-of-principle was performed using a model emulsion consisting of immiscible aqueous and organic solvent components. Droplet coalescence was identified as a key aspect influencing the separation process, with quite different effects during separation on open surfaces as compared to slit geometry. For a detailed description of this observation, an analytical model was derived and lattice Boltzmann computer simulations were performed. By use of grazing incidence small angle x-ray scattering (GISAXS) interfacial nanostructures during gold nanoparticle deposition in a flow field were probed to demonstrate the potential of GISAXS for in situ investigations during flow.

  13. Radio-iodinated surface proteins of electrophoretically separated rat lymphocytes

    International Nuclear Information System (INIS)

    Jilg, W.; Hannig, K.; Zeiller, K.

    1980-01-01

    Rat thymocytes and lymph node cells were separated into three T and one B subpopulation by means of free flow electrophoresis. The surface proteins of the separated cells were labelled by lactoperoxidase catalysed radioiodination. Most of the label was demonstrated to be at the cell surface. Although the surface protein patterns of the four lamphocyte subpopulations were rather similar, distinctive differences could be found. B cells had six labelled proteins which seemed to be absent in the other cells. In the T cell group three protein bands were identified, each with specificity for peripheral T cells, thymocytes and all T cells respectively. Four other proteins were found which showed quantitative differences between the four cell groups. (orig.) [de

  14. Pyrohydrolytic separation technique for fluoride and chloride from radioactive liquid wastes

    International Nuclear Information System (INIS)

    Sawant, R.M.; Mahajan, M.A.; Shah, D.J.; Thakur, U.K.; Ramakumar, K.L.

    2009-01-01

    A rapid method for simultaneous determination of fluorine and chlorine in liquid samples with ion chromatography after pyrohydrolysis separation was proposed for routine analysis. The elements were separated from radioactive liquid sample by pyrohydrolysis and were subsequently determined with ion chromatography. Total time taken to determine these elements is about 45 min including 30 min for the pyrohydrolysis and 15 min for ion chromatography. The results of recovery tests ranged 95% or above. The limits of detection for F and Cl are 0.5 and 0.8 mgkg -1 , respectively. (author)

  15. Pyrohydrolytic separation technique for fluoride and chloride from radioactive liquid wastes

    International Nuclear Information System (INIS)

    Sawant, R.M.; Mahajan, M.A.; Shah, D.J.; Thakur, U.K.; Ramakumar, K.L.

    2011-01-01

    A rapid method for simultaneous determination of fluorine and chlorine in radioactive liquid wastes with ion chromatography after pyrohydrolysis separation was proposed for routine analysis. The elements were separated from radioactive liquid wastes by pyrohydrolysis and were subsequently determined with ion chromatography. Total time taken to determine these elements is about 45 min including 30 min for the pyrohydrolysis and 15 min for ion chromatography. The results of recovery tests ranged 95% or above. The limits of detection for F and Cl are 0.5 and 0.8 mg kg -1 , respectively. (author)

  16. A review of phase separation in borosilicate glasses, with reference to nuclear fuel waste immobilization

    International Nuclear Information System (INIS)

    Taylor, P.

    1990-08-01

    This report reviews information on miscibility limits in borosilicate glass-forming systems. It includes both a literature survey and an account of experimental work performed within the Canadian Nuclear Fuel Waste Management Program. Emphasis is placed on the measurement and depiction of miscibility limits in multicomponent (mainly quaternary) systems, and the effects of individual components on the occurrence of phase separation. The behaviour of the multicomponent system is related to that of simpler (binary and ternary) glass systems. The possible occurrence of phase separation, as well as its avoidance, during processing of nuclear waste glasses is discussed

  17. CENTRIFUGAL SEPARATORS

    Science.gov (United States)

    Skarstrom, C.

    1959-03-10

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

  18. Aerodynamic effects in isotope separation by gaseous diffusion

    International Nuclear Information System (INIS)

    Bert, L.A.; Prosperetti, A.; Fiocchi, R.

    1978-01-01

    The turbulent flow of an isotopic mixture in a porous-walled pipe is considered in the presence of suction through the wall. A simple model is formulated for the evaluation of aerodynamic effects on the separation efficiency. The predictions of the model are found to compare very favourably with experiment. In the limit of small suction velocities, results obtained by other investigators for diffusion in a turbulent steam are recovered. (author)

  19. Symbolic meanings of sex in relationships: Developing the Meanings of Sexual Behavior Inventory.

    Science.gov (United States)

    Shaw, Amanda M; Rogge, Ronald D

    2017-10-01

    Consistent with symbolic interactionism and motivation research, the study explored the meanings of sexual behavior in romantic relationships in a sample of 3,003 online respondents. Starting with a pool of 104 respondent-generated items, Exploratory and Confirmatory Factor analyses in separate sample halves revealed a stable set of 9 dimensions within that item pool that formed 2 higher-order factors representing positive (to share pleasure, to bond, to de-stress, to energize the relationship, to learn more about each other) and negative (to manage conflict, as an incentive, to express anger, and to control partner) meanings of sexual behavior within relationships. Item Response Theory analyses helped select the 4-5 most effective items of each dimension for inclusion in the Meanings of Sexual Behavior Inventory (MoSBI). Generalizability analyses suggested that the MoSBI subscale scores continued to show high levels of internal consistency across a broad range of demographic subgroups (e.g., racial/ethnic groups, gay and lesbian respondents, and various levels of education). The MoSBI subscales demonstrated moderate and distinct patterns of association with a range of conceptual boundary scales (e.g., relationship and sexual satisfaction, emotional support, negative conflict behavior, and frequency of sexual behavior) suggesting that these scales represent novel relationship processes. Consistent with this, analyses in the 862 respondents completing a 2-month follow-up assessment suggested that the meanings of sexual behavior predicted residual change in relationship satisfaction, even after controlling for frequency of sexual behavior within the relationships. Implications are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  20. Quadrant Dynamic with Automatic Plateau Limit Histogram Equalization for Image Enhancement

    Directory of Open Access Journals (Sweden)

    P. Jagatheeswari

    2014-01-01

    Full Text Available The fundamental and important preprocessing stage in image processing is the image contrast enhancement technique. Histogram equalization is an effective contrast enhancement technique. In this paper, a histogram equalization based technique called quadrant dynamic with automatic plateau limit histogram equalization (QDAPLHE is introduced. In this method, a hybrid of dynamic and clipped histogram equalization methods are used to increase the brightness preservation and to reduce the overenhancement. Initially, the proposed QDAPLHE algorithm passes the input image through a median filter to remove the noises present in the image. Then the histogram of the filtered image is divided into four subhistograms while maintaining second separated point as the mean brightness. Then the clipping process is implemented by calculating automatically the plateau limit as the clipped level. The clipped portion of the histogram is modified to reduce the loss of image intensity value. Finally the clipped portion is redistributed uniformly to the entire dynamic range and the conventional histogram equalization is executed in each subhistogram independently. Based on the qualitative and the quantitative analysis, the QDAPLHE method outperforms some existing methods in literature.

  1. Issue of Separation of Powers in Ancient Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Javid

    2012-03-01

    Full Text Available Cotemporary public law in Iran cannot ignore the elements of its identity in the past. Although analysis of public law issue in ancient Iran, the most researchers to be considered so it is not easy to speak about separation of powers, the part of the body of public law in the Iran primary governments but this article constants on hypothesis which with think and assimilation in history of ancient Iran which can laying the groundwork of strengthening people rights and limitation of authority's governors with emphasis on three periods of governorship on ancient Iran .for example Hakhamaneshian, Ashkanian and Sasanian. This article intent to clear haw can in these periods, the primary figure and foundation of separation of powers and functions division in body of previous governments of Iran to be observed.

  2. Monte Carlo analysis of thermochromatography as a fast separation method for nuclear forensics

    International Nuclear Information System (INIS)

    Garrison, J.R.; Hanson, D.E.; Hall, H.L.

    2012-01-01

    Nuclear forensic science has become increasingly important for global nuclear security, and enhancing the timeliness of forensic analysis has been established as an important objective in the field. New, faster techniques must be developed to meet this objective. Current approaches for the analysis of minor actinides, fission products, and fuel-specific materials require time-consuming chemical separation coupled with measurement through either nuclear counting or mass spectrometry. These very sensitive measurement techniques can be hindered by impurities or incomplete separation in even the most painstaking chemical separations. High-temperature gas-phase separation or thermochromatography has been used in the past for the rapid separations in the study of newly created elements and as a basis for chemical classification of that element. This work examines the potential for rapid separation of gaseous species to be applied in nuclear forensic investigations. Monte Carlo modeling has been used to evaluate the potential utility of the thermochromatographic separation method, albeit this assessment is necessarily limited due to the lack of available experimental data for validation. (author)

  3. Monte Carlo analysis of thermochromatography as a fast separation method for nuclear forensics

    International Nuclear Information System (INIS)

    Hall, Howard L.

    2012-01-01

    Nuclear forensic science has become increasingly important for global nuclear security, and enhancing the timeliness of forensic analysis has been established as an important objective in the field. New, faster techniques must be developed to meet this objective. Current approaches for the analysis of minor actinides, fission products, and fuel-specific materials require time-consuming chemical separation coupled with measurement through either nuclear counting or mass spectrometry. These very sensitive measurement techniques can be hindered by impurities or incomplete separation in even the most painstaking chemical separations. High-temperature gas-phase separation or thermochromatography has been used in the past for the rapid separations in the study of newly created elements and as a basis for chemical classification of that element. This work examines the potential for rapid separation of gaseous species to be applied in nuclear forensic investigations. Monte Carlo modeling has been used to evaluate the potential utility of the thermochromatographic separation method, albeit this assessment is necessarily limited due to the lack of available experimental data for validation.

  4. What to Do When K-Means Clustering Fails: A Simple yet Principled Alternative Algorithm.

    Science.gov (United States)

    Raykov, Yordan P; Boukouvalas, Alexis; Baig, Fahd; Little, Max A

    The K-means algorithm is one of the most popular clustering algorithms in current use as it is relatively fast yet simple to understand and deploy in practice. Nevertheless, its use entails certain restrictive assumptions about the data, the negative consequences of which are not always immediately apparent, as we demonstrate. While more flexible algorithms have been developed, their widespread use has been hindered by their computational and technical complexity. Motivated by these considerations, we present a flexible alternative to K-means that relaxes most of the assumptions, whilst remaining almost as fast and simple. This novel algorithm which we call MAP-DP (maximum a-posteriori Dirichlet process mixtures), is statistically rigorous as it is based on nonparametric Bayesian Dirichlet process mixture modeling. This approach allows us to overcome most of the limitations imposed by K-means. The number of clusters K is estimated from the data instead of being fixed a-priori as in K-means. In addition, while K-means is restricted to continuous data, the MAP-DP framework can be applied to many kinds of data, for example, binary, count or ordinal data. Also, it can efficiently separate outliers from the data. This additional flexibility does not incur a significant computational overhead compared to K-means with MAP-DP convergence typically achieved in the order of seconds for many practical problems. Finally, in contrast to K-means, since the algorithm is based on an underlying statistical model, the MAP-DP framework can deal with missing data and enables model testing such as cross validation in a principled way. We demonstrate the simplicity and effectiveness of this algorithm on the health informatics problem of clinical sub-typing in a cluster of diseases known as parkinsonism.

  5. Steam-water separator

    International Nuclear Information System (INIS)

    Modrak, T.M.; Curtis, R.W.

    1978-01-01

    A two-stage steam-water separating device is introduced, where the second stage is made as a cyclone separator. The water separated here is collected in the first stage of the inner tube and is returned to the steam raising unit. (TK) [de

  6. Isotopic separation

    International Nuclear Information System (INIS)

    Chen, C.L.

    1979-01-01

    Isotopic species in an isotopic mixture including a first species having a first isotope and a second species having a second isotope are separated by selectively exciting the first species in preference to the second species and then reacting the selectively excited first species with an additional preselected radiation, an electron or another chemical species so as to form a product having a mass different from the original species and separating the product from the balance of the mixture in a centrifugal separating device such as centrifuge or aerodynamic nozzle. In the centrifuge the isotopic mixture is passed into a rotor where it is irradiated through a window. Heavier and lighter components can be withdrawn. The irradiated mixture experiences a large centrifugal force and is separated in a deflection area into lighter and heavier components. (UK)

  7. Garden hose separation of gaseous isotopes. Part II. Supersonic accelerations

    International Nuclear Information System (INIS)

    Wang, C.G.; Davis, A.G.M.

    1979-01-01

    A mechanical process for separating gaseous mixtures according to their respective molecular weights, by a variation of the time-of-flight process, is proposed. The separative apparatus consists of several sets of nozzle-deflector combinations surrounded by a stationary collector housed in an evacuated chamber. From a rotating supersonic nozzle, a contiguous plurality of successive groups of molecules is ejected to form a continuous stream of the mixture. The molecules of each group of molecules are allowed to accelerate for a predetermined period of time following their supersonic expansion, thereby allowing each group of molecules to form a generally spherical configuration, the outer radius of which will be enriched in molecules of lighter mass, relative to lesser radii. A deflector means co-rotating with the nozzle is used to deflect molecules that have been allowed to move for the predetermined period of time in accordance with their expansion velocities, from at least one desired portion of the stream, and a stationary collector means is disposed to receive the deflected molecules. The estimated separative work produced from such a unit is about the same or better than that of a modern giant diffuser of similar dimensions. However, with an essentially empty chamber, the unit capital cost as well as the energy required is competitive with any of the well-known methods, mechanical or otherwise

  8. Circuit modification in electrical field flow fractionation systems generating higher resolution separation of nanoparticles.

    Science.gov (United States)

    Tasci, Tonguc O; Johnson, William P; Fernandez, Diego P; Manangon, Eliana; Gale, Bruce K

    2014-10-24

    Compared to other sub-techniques of field flow fractionation (FFF), cyclical electrical field flow fractionation (CyElFFF) is a relatively new method with many opportunities remaining for improvement. One of the most important limitations of this method is the separation of particles smaller than 100nm. For such small particles, the diffusion rate becomes very high, resulting in severe reductions in the CyElFFF separation efficiency. To address this limitation, we modified the electrical circuitry of the ElFFF system. In all earlier ElFFF reports, electrical power sources have been directly connected to the ElFFF channel electrodes, and no alteration has been made in the electrical circuitry of the system. In this work, by using discrete electrical components, such as resistors and diodes, we improved the effective electric field in the system to allow high resolution separations. By modifying the electrical circuitry of the ElFFF system, high resolution separations of 15 and 40nm gold nanoparticles were achieved. The effects of applying different frequencies, amplitudes and voltage shapes have been investigated and analyzed through experiments. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Means for controlling operation of power sources associated with an axial tomographic system

    International Nuclear Information System (INIS)

    1976-01-01

    An axial tomographic system is described having scanner means normally in an off-condition where all associated power sources are electrically isolated from the units driven thereby. It also includes means for activating the scanner means to establish an on-condition, control means including means to measure one or more system parameters when the scanner means is in an on-condition and to determine if the measured parameters are within predetermined limits, and means for maintaining the on-condition only if the control means is properly operational and all measured system parameters are within the predetermined limits

  10. Safety shutdown separators

    Science.gov (United States)

    Carlson, Steven Allen; Anakor, Ifenna Kingsley; Farrell, Greg Robert

    2015-06-30

    The present invention pertains to electrochemical cells which comprise (a) an anode; (b) a cathode; (c) a solid porous separator, such as a polyolefin, xerogel, or inorganic oxide separator; and (d) a nonaqueous electrolyte, wherein the separator comprises a porous membrane having a microporous coating comprising polymer particles which have not coalesced to form a continuous film. This microporous coating on the separator acts as a safety shutdown layer that rapidly increases the internal resistivity and shuts the cell down upon heating to an elevated temperature, such as 110.degree. C. Also provided are methods for increasing the safety of an electrochemical cell by utilizing such separators with a safety shutdown layer.

  11. Experimental Study of Unsteady Flow Separation in a Laminar Boundary Layer

    Science.gov (United States)

    Bonacci, Andrew; Lang, Amy; Wahidi, Redha; Santos, Leonardo

    2017-11-01

    Flow separation, caused by an adverse pressure gradient, is a major problem in many applications. Reversing flow near the wall is the first sign of incipient separation and can bristle shark scales which may be linked to a passive, flow actuated separation control mechanism. An investigation of how this backflow forms and how it interacts with shark skin is of interest due to the fact that this could be used as a bioinspired means of initiating flow control. A water tunnel experiment aims to study unsteady separation with a focus on the reversing flow development near the wall within a flat plate laminar boundary layer (Re on order of 105) as an increasing adverse pressure gradient is induced by a rotating cylinder. Unsteady reversing flow development is documented using DPIV. Funding was provided by the National Science Foundation under the Research Experience for Undergraduates (REU) program (EEC 1659710) and the Army Research Office.

  12. Isotope separation process

    International Nuclear Information System (INIS)

    Cox, D.M.; Maas, E.T.

    1982-01-01

    Processes are disclosed for the separation of isotopes of an element comprising vaporizing uranyl compounds having the formula (UO2a2)n, where a is a monovalent anion and n in an integer from 2 to 4, the compounds having an isotopically shifted infrared absorption spectrum associated with uranyl ions containing said element which is to be separated, and then irradiating the uranyl compound with infrared radiation which is preferentially absorbed by a molecular vibration of uranyl ions of the compound containing a predetermined isotope of that element so that excited molecules of the compound are provided which are enriched in the molecules of the compound containing that predetermined isotope, thus enabling separation of these excited molecules. The processes disclosed include separation of the excited molecules by irradiating under conditions such that the excited molecules dissociate, and also separating the excited molecules by a discrete separation step. The latter includes irradiating the excited molecules by a second infrared laser in order to convert the excited molecules into a separable product, or also by chemically converting the excited molecules, preferably by reaction with a gaseous reactant

  13. Application of independent component analysis for speech-music separation using an efficient score function estimation

    Science.gov (United States)

    Pishravian, Arash; Aghabozorgi Sahaf, Masoud Reza

    2012-12-01

    In this paper speech-music separation using Blind Source Separation is discussed. The separating algorithm is based on the mutual information minimization where the natural gradient algorithm is used for minimization. In order to do that, score function estimation from observation signals (combination of speech and music) samples is needed. The accuracy and the speed of the mentioned estimation will affect on the quality of the separated signals and the processing time of the algorithm. The score function estimation in the presented algorithm is based on Gaussian mixture based kernel density estimation method. The experimental results of the presented algorithm on the speech-music separation and comparing to the separating algorithm which is based on the Minimum Mean Square Error estimator, indicate that it can cause better performance and less processing time

  14. [Carbon monoxide tests in a steady state. Uptake and transfer capacity, normal values and lower limits].

    Science.gov (United States)

    Ramonatxo, M; Préfaut, C; Guerrero, H; Moutou, H; Bansard, X; Chardon, G

    1982-01-01

    The aim of this study was to establish data which would best demonstrate the variations of different tests using Carbon Monoxide as a tracer gas (total and partial functional uptake coefficient and transfer capacity) to establish mean values and lower limits of normal of these tests. Multivariate statistical analysis was used; in the first stage a connection was sought between the fractional uptake coefficient (partial and total) to other parameters, comparing subjects and data. In the second stage the comparison was refined by eliminating the least useful data, trying, despite a small loss of material, to reveal the most important connections, linear or otherwise. The fractional uptake coefficients varied according to sex, also the variation of the partial alveolar-expired fractional uptake equivalent (DuACO) was largely a function of respiratory rate and tidal volume. The alveolar-arterial partial fractional uptake equivalent (DuaCO) depended more on respiratory frequency and age. Finally the total fractional uptake coefficient (DuCO) and the transfer capacity corrected per liter of ventilation (TLCO/V) were functions of these parameters. The last stage of this work, after taking account of the statistical observations consistent with the facts of these physiological hypotheses led to a search for a better way of approaching the laws linking the collected data to the fractional uptake coefficient. The lower limits of normal were arbitrarily defined, separating those 5% of subjects deviating most strongly from the mean. As a result, the relationship between the lower limit of normal and the theoretical mean value was 90% for the partial and total fractional uptake coefficient and 70% for the transfer capacity corrected per liter of ventilation.

  15. Method of separating radioactive krypton gas

    International Nuclear Information System (INIS)

    Kimura, Shigeru; Awada, Yoshihisa.

    1975-01-01

    Object: To effectively and safely separate and recover Kr-85, which requires a long storage period for attenuating radioactivity, from a mixture gas consisting of Kr-85 and Xe by a liquefaction distillation method. Structure: A mixture gas consisting of Kr and Xe is subjected to heat exchange in a cooler with Freon gas from a plurality of distillation towers for its temperature reduction from normal temperature to a lower temperature, and then it is supplied to a distillation tower. The distillation tower is held at a pressure above 15 ata, preferably around 20 ata, and a condenser provided at the top of the distillation tower is furnished with Freon as cooling medium. The rare mixture gas is distilled by liquefaction within a distillation tower, and Kr-85 is obtained from a top duct while obtaining Xe from a bottom duct. Xe after separation by liquefaction is returned to a rare mixture gas supply inlet of a liquefaction distillation means for repeated refinement in the distillation tower. (Kamimura, M.)

  16. Neptunium immobilization and recovery using phase separated glasses

    International Nuclear Information System (INIS)

    Meaker, T.F.

    1997-01-01

    A phase separated (amorphous) glass has been developed which allows very efficient recovery of +4 valence actinides. The total amount of crystal formation in a heat treated vycor-type glass can be controlled with time, temperature and loading. Heat treatments at lower temperatures and for less time inhibit crystal formation while still allowing significant phase separation. If the Thorium loading exceeds 10 weight percent oxide, crystal formation during heat treatment may not be avoided. The total amount of crystal growth has a direct affect on thorium leachability. An increase in crystal formation limits the Th recovery significantly. High thorium loaded glasses (15 weight percent) with heat treatments (increased crystal formation) leach at approximately the same rate as non-heat treated glasses. A phase separated (amorphous) glass has been produced using thorium as a surrogate for neptunium. Two different homogeneous vycor compositions targeting 10 and 15 weight percent thorium oxide have been processed, heat treated and leached with concentrated nitric acid at 110 degrees C. Thorium recovery rates have been shown to be considerably better when the glass has been heat treated inducing phase separation that is relatively crystal free. Non-heat treated and crystalline (due to heat treatment) glasses have similar Th recovery rates with respect to surface area. Phase separated amorphous samples were found to have significantly higher thorium concentrations in the leachate compared to non-heat treated and crystalline glasses for all mesh sizes. All glasses had increased thorium concentration in the leachate as surface area increased

  17. PVC removal from mixed plastics by triboelectrostatic separation

    International Nuclear Information System (INIS)

    Park, Chul-Hyun; Jeon, Ho-Seok; Park, Jai-Koo

    2007-01-01

    Ever increasing oil price and the constant growth in generation of waste plastics stimulate a research on material separation for recycling of waste plastics. At present, most waste plastics cause serious environmental problems due to the disposal by reclamation and incineration. Particularly, polyvinyl chloride (PVC) materials among waste plastics generates hazardous HCl gas, dioxins containing Cl, and so on, which lead to air pollution and shorten the life of incinerator, and it makes difficultly recycling of other plastics. Therefore, we designed a bench scale triboelectrostatic separator for PVC removal from mixed plastics (polyvinyl chloride/polyethylene terephthalate), and then carried out material separation tests. In triboelectrostatic separation, PVC and PET particles are charged negatively and positively, respectively, due to the difference of the work function of plastics in tribo charger of the fluidized-bed, and are separated by means of splitter through an opposite electric field. In this study, the charge efficiency of PVC and PET was strongly dependent on the tribo charger material (polypropylene), relative humidity (below 30%), air velocity (over 10 m/s), and mixture ratio (PET:PVC = 1:1). At the optimum conditions (electrode potential of 20 kV and splitter position of -2 cm), PVC rejection and PET recovery in PET products were 99.60 and 98.10%, respectively, and the reproducibility of optimal test was very good (±1%). In addition, as a change of splitter position, we developed the technique to recover high purity PET (over 99.99%) although PET recovery decreases by degrees

  18. Einstein-Podolsky-Rosen-like separability indicators for two-mode Gaussian states

    Science.gov (United States)

    Marian, Paulina; Marian, Tudor A.

    2018-02-01

    We investigate the separability of the two-mode Gaussian states (TMGSs) by using the variances of a pair of Einstein-Podolsky-Rosen (EPR)-like observables. Our starting point is inspired by the general necessary condition of separability introduced by Duan et al (2000 Phys. Rev. Lett. 84 2722). We evaluate the minima of the normalized forms of both the product and sum of such variances, as well as that of a regularized sum. Making use of Simon’s separability criterion, which is based on the condition of positivity of the partial transpose (PPT) of the density matrix (Simon 2000 Phys. Rev. Lett. 84 2726), we prove that these minima are separability indicators in their own right. They appear to quantify the greatest amount of EPR-like correlations that can be created in a TMGS by means of local operations. Furthermore, we reconsider the EPR-like approach to the separability of TMGSs which was developed by Duan et al with no reference to the PPT condition. By optimizing the regularized form of their EPR-like uncertainty sum, we derive a separability indicator for any TMGS. We prove that the corresponding EPR-like condition of separability is manifestly equivalent to Simon’s PPT one. The consistency of these two distinct approaches (EPR-like and PPT) affords a better understanding of the examined separability problem, whose explicit solution found long ago by Simon covers all situations of interest.

  19. Neutron-activation determination of phosphorus using extraction separation of phosphate-ion with dialkylti dinitrates

    International Nuclear Information System (INIS)

    Yakovlev, Yu.V.; Kolotov, V.P.

    1981-01-01

    The selectivity of phosphorus (5) separation has been studied using dialkyltin dinitrates-promising reagents for extraction of oxygen-containing anions. Procedures have been developed for separating phosphorus in the presence of macro amounts of some interfering-elements (Al, Fe, Mo and Zr). The procedure was used for neutron activation determination of phosphorus in aluminium. The limit of detection was 5x10 -10 g [ru

  20. Device for separating and concentrating rare gases containing krypton gas

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, S; Sugimoto, K

    1975-06-11

    In orer to highly concentrate krypton by means of adsorption and desorption of activated carbon, in a device for continuously separating and concentrating rare gases containing krypton gas by means of adsorbing and desorbing operation of activated carbon, the device includes adsorbers arranged in parallel and more than two stages of adsorbers arranged in series with the first mentioned adsorbers with the amount of activated carbon filled successively reduced, and a cooling mechanism for cooling the adsorbers when adsorbed and a heating mechanism for heating the adsorbers when desorbed.

  1. 50 CFR 660.331 - Limited entry and open access fisheries-general.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Limited entry and open access fisheries... West Coast Groundfish Fisheries § 660.331 Limited entry and open access fisheries—general. All... entry and open access fisheries, except such fishing by treaty Indian tribes as may be separately...

  2. Uranium isotope separation from 1941 to the present

    International Nuclear Information System (INIS)

    Maier-Komor, Peter

    2010-01-01

    Uranium isotope separation was the key development for the preparation of highly enriched isotopes in general and thus became the seed for target development and preparation for nuclear and applied physics. In 1941 (year of birth of the author) large-scale development for uranium isotope separation was started after the US authorities were warned that NAZI Germany had started its program for enrichment of uranium and might have confiscated all uranium and uranium mines in their sphere of influence. Within the framework of the Manhattan Projects the first electromagnetic mass separators (Calutrons) were installed and further developed for high throughput. The military aim of the Navy Department was to develop nuclear propulsion for submarines with practically unlimited range. Parallel to this the army worked on the development of the atomic bomb. Also in 1941 plutonium was discovered and the production of 239 Pu was included into the atomic bomb program. 235 U enrichment starting with natural uranium was performed in two steps with different techniques of mass separation in Oak Ridge. The first step was gas diffusion which was limited to low enrichment. The second step for high enrichment was performed with electromagnetic mass spectrometers (Calutrons). The theory for the much more effective enrichment with centrifugal separation was developed also during the Second World War, but technical problems e.g. development of high speed ball and needle bearings could not be solved before the end of the war. Spying accelerated the development of uranium separation in the Soviet Union, but also later in China, India, Pakistan, Iran and Iraq. In this paper, the physical and chemical procedures are outlined which lead to the success of the project. Some security aspects and Non-Proliferation measures are discussed.

  3. Uranium isotope separation from 1941 to the present

    Energy Technology Data Exchange (ETDEWEB)

    Maier-Komor, Peter, E-mail: Peter@Maier-Komor.d [Retired from Physik-Department E12, Technische Universitaet Muenchen, D-85747 Garching (Germany)

    2010-02-11

    Uranium isotope separation was the key development for the preparation of highly enriched isotopes in general and thus became the seed for target development and preparation for nuclear and applied physics. In 1941 (year of birth of the author) large-scale development for uranium isotope separation was started after the US authorities were warned that NAZI Germany had started its program for enrichment of uranium and might have confiscated all uranium and uranium mines in their sphere of influence. Within the framework of the Manhattan Projects the first electromagnetic mass separators (Calutrons) were installed and further developed for high throughput. The military aim of the Navy Department was to develop nuclear propulsion for submarines with practically unlimited range. Parallel to this the army worked on the development of the atomic bomb. Also in 1941 plutonium was discovered and the production of {sup 239}Pu was included into the atomic bomb program. {sup 235}U enrichment starting with natural uranium was performed in two steps with different techniques of mass separation in Oak Ridge. The first step was gas diffusion which was limited to low enrichment. The second step for high enrichment was performed with electromagnetic mass spectrometers (Calutrons). The theory for the much more effective enrichment with centrifugal separation was developed also during the Second World War, but technical problems e.g. development of high speed ball and needle bearings could not be solved before the end of the war. Spying accelerated the development of uranium separation in the Soviet Union, but also later in China, India, Pakistan, Iran and Iraq. In this paper, the physical and chemical procedures are outlined which lead to the success of the project. Some security aspects and Non-Proliferation measures are discussed.

  4. Uranium isotope separation from 1941 to the present

    Science.gov (United States)

    Maier-Komor, Peter

    2010-02-01

    Uranium isotope separation was the key development for the preparation of highly enriched isotopes in general and thus became the seed for target development and preparation for nuclear and applied physics. In 1941 (year of birth of the author) large-scale development for uranium isotope separation was started after the US authorities were warned that NAZI Germany had started its program for enrichment of uranium and might have confiscated all uranium and uranium mines in their sphere of influence. Within the framework of the Manhattan Projects the first electromagnetic mass separators (Calutrons) were installed and further developed for high throughput. The military aim of the Navy Department was to develop nuclear propulsion for submarines with practically unlimited range. Parallel to this the army worked on the development of the atomic bomb. Also in 1941 plutonium was discovered and the production of 239Pu was included into the atomic bomb program. 235U enrichment starting with natural uranium was performed in two steps with different techniques of mass separation in Oak Ridge. The first step was gas diffusion which was limited to low enrichment. The second step for high enrichment was performed with electromagnetic mass spectrometers (Calutrons). The theory for the much more effective enrichment with centrifugal separation was developed also during the Second World War, but technical problems e.g. development of high speed ball and needle bearings could not be solved before the end of the war. Spying accelerated the development of uranium separation in the Soviet Union, but also later in China, India, Pakistan, Iran and Iraq. In this paper, the physical and chemical procedures are outlined which lead to the success of the project. Some security aspects and Non-Proliferation measures are discussed.

  5. ALPHA-BETA SEPARATION PORTFOLIO STRATEGIES FOR ISLAMIC FINANCE

    Directory of Open Access Journals (Sweden)

    Valentyn Khokhlov

    2016-11-01

    Full Text Available The purpose of this paper is to develop a mathematical alpha-beta separation model that can be used to create a core-satellite portfolio management strategy that complies with the principles of Islamic finance. Methodology. Core-satellite portfolio construction methodology is used to implement the alpha-beta separation approach, where the core part of the portfolio is managed using the tracking error minimization strategy, and the satellite part of the portfolio is managed using the mean-variance optimization strategy. Results of the portfolio dynamics clearly show that a significant amount of value was created by alpha-beta separation. The typical alpha ranges from 4% to 5.7%. The most aggressive portfolio strategies that allow short positions in the satellite portfolio work best with frequent rebalancing and benefit from the active bets. Smoothing technique that was introduced to decrease the portfolio turnover and stabilize its composition works better when active bets are less efficient, particularly with less frequent rebalancing. The best risk-return combinations are achieved with modest (3% to 10% allocation of the total portfolio to the satellite, and the remaining part (90% to 97% being managed in order to minimize the tracking error. Practical implications. The alpha-beta separation framework suggested in this paper can be used to enhance the portfolio management techniques for the hedge funds that operate under tight restrictions, particularly under the Islamic finance principles. The mathematical models developed in this paper allow practical implementation of the alphabeta separation concept. Originality/value. While the idea of alpha-beta separation existed in hedge fund management before, there was no comprehensive mathematical model under it, so its implementation was based on the ad hoc approach. This paper introduces such a mathematical model and demonstrates how portfolio managers can create value for their clients using it.

  6. Lithium isotope separation factors of some two-phase equilibrium systems

    International Nuclear Information System (INIS)

    Palko, A.A.; Drury, J.S.; Begun, G.M.

    1976-01-01

    Isotope separation factors of seventeen two-phase equilibrium systems for lithium isotope enrichment have been determined. In all cases, lithium amalgam was used as one of the lithium-containing phases and was equilibrated with an aqueous or organic phase containing a lithium compound. In all systems examined, isotopic exchange was found to be extremely rapid, and 6 Li was concentrated in the amalgam phase. The isotopic separation factor for the LiOH(aqueous) vs Li(amalgam) system has been studied as a function of temperature from -2 to 80 degreeC. The values obtained have been compared with the ''electrolysis'' and exchange separation factors given in the literature. The two-phase systems, LiCl(ethylenediamine) vs Li(amalgam) and LiCl(propylenediamine) vs Li(amalgam), have been studied, and the isotopic separation factors have been determined as functions of the temperature. The factors for the two systems have been found to be substantially the same (within limits of the errors involved) over the temperature range studied (0 to 100 degreeC) as those for the aqueous system. The isotopic separation factors for the seventeen systems have been tabulated, and correlations have been drawn that show the salt and solvent effects upon the values obtained

  7. Molecular dynamics simulations of phase separation in the presence of surfactants

    DEFF Research Database (Denmark)

    Laradji, Mohamed; Mouritsen, Ole G.; Toxvaerd, Søren

    1994-01-01

    The dynamics of phase separation in two-dimensional binary mixtures diluted by surfactants is studied by means of molecular dynamics simulations. In contrast to pure binary systems, characterized by an algebraic time dependence of the average domain size, we find that systems containing surfactants...... not fully phase separate, we observe a dynamical scaling which is independent of the surfactant concentration. The results of these simulations are in general in agreement with previous Langevin simulations [Laradji, Guo, Grant, and Zuckermann, J. Phys. A 44, L629 (1991)] and a theory of Ostwald ripening...... exhibit nonalgebraic, slow dynamics. The average domain size eventually saturates at a value inversely proportional to the surfactant concentration. We also find that phase separation in systems with different surfactant concentrations follow a crossover scaling form. Finally, although these systems do...

  8. Foam droplet separation for nanoparticle synthesis

    International Nuclear Information System (INIS)

    Tyree, Corey A.; Allen, Jonathan O.

    2008-01-01

    A novel approach to nanoparticle synthesis was developed whereby foam bubble bursting produced aerosol droplets, an approach patterned after the marine foam aerosol cycle. The droplets were dried to remove solvent, leaving nanometer-sized particles composed of precursor material. Nanoparticles composed of sodium chloride (mean diameter, D-bar p ∼ 100 nm), phosphotungstic acid (D-bar p ∼ 55 nm), and bovine insulin (D p ∼ 5-30 nm) were synthesized. Foam droplet separation can be carried out at ambient temperature and pressure. The 'soft' nature of the process makes it compatible with a wide range of materials

  9. Isotope separation

    International Nuclear Information System (INIS)

    Eerkens, J.W.

    1979-01-01

    A method of isotope separation is described which involves the use of a laser photon beam to selectively induce energy level transitions of an isotope molecule containing the isotope to be separated. The use of the technique for 235 U enrichment is demonstrated. (UK)

  10. MEANS AND METHODS OF CYBER WARFARE

    Directory of Open Access Journals (Sweden)

    Dan-Iulian VOITAȘEC

    2016-06-01

    Full Text Available According to the Declaration of Saint Petersburg of 1868 “the only legitimate object which States should endeavor to accomplish during war is to weaken the military forces of the enemy”. Thus, International Humanitarian Law prohibits or limits the use of certain means and methods of warfare. The rapid development of technology has led to the emergence of a new dimension of warfare. The cyber aspect of armed conflict has led to the development of new means and methods of warfare. The purpose of this paper is to study how the norms of international humanitarian law apply to the means and methods of cyber warfare.

  11. Reproducibility of mean nuclear volume and correlation with mean nuclear area in breast cancer

    DEFF Research Database (Denmark)

    Baak, J P; Ladekarl, M; Sørensen, Flemming Brandt

    1994-01-01

    reproducible and strongly correlated with nuclear vv assessed in the TOTAL. In invasive breast cancer assessments in the whole tumor section can be used if delineation of the measurement area cannot be done easily. In small areas with a limited number of nuclei (eg, microinvasive parts) MNA can be easier......Previous studies have shown that quantitative, histopathologic features obtained from a carefully selected area in the tumor section ("selective" approach) have a strong prognostic value in breast cancer. On the other hand, it was found that mean nuclear volume estimation in the whole area...... as to their intraobserver and interobserver reproducibility in 22 invasive breast cancer cases. The mean nuclear volume (nuclear vv) was assessed both in the most atypical area (AREA) (selected on morphologic criteria) and in the whole tumor section (TOTAL). Furthermore, the correlation with mean nuclear (profile) area...

  12. Separation of flow

    CERN Document Server

    Chang, Paul K

    2014-01-01

    Interdisciplinary and Advanced Topics in Science and Engineering, Volume 3: Separation of Flow presents the problem of the separation of fluid flow. This book provides information covering the fields of basic physical processes, analyses, and experiments concerning flow separation.Organized into 12 chapters, this volume begins with an overview of the flow separation on the body surface as discusses in various classical examples. This text then examines the analytical and experimental results of the laminar boundary layer of steady, two-dimensional flows in the subsonic speed range. Other chapt

  13. Entrainment separator performance

    International Nuclear Information System (INIS)

    First, M.W.; Leith, D.

    1976-01-01

    Clean and dust-loaded ACS entrainment separators mounted upstream of HEPA filters were exposed to a combination of fine water mist and steam at about 70 0 C from one to four hours. In every trial, the ACS entrainment separator prevented measurable deterioration of performance in the following HEPA filter. Droplet size-efficiency evaluation of the ACS entrainment separators showed that, within the accuracy of the measurements, they meet all service requirements and are fully equal to the best separator units available for service on pressurized water reactors

  14. Dynamic separation of pulmonary and cardiac changes in electrical impedance tomography

    International Nuclear Information System (INIS)

    Deibele, J M; Luepschen, H; Leonhardt, S

    2008-01-01

    In spontaneously breathing or ventilated subjects, it is difficult to image cardiac-related conductivity changes using electrical impedance tomography (EIT) due to the high amplitude of the ventilation component. Previous attempts to separate these components included either electrocardiogram-gated averaging, frequency domain filtering or holding the breath while performing the measurements. However, such methods are either not able to produce continuous real-time images or to fully separate cardiac and pulmonary changes. The aim of this work was to develop a new dynamic filtering method for the online separation of pulmonary and cardiac changes avoiding the drawbacks of the previous attempts. The approach is based on estimating template functions for the pulmonary and cardiac components by means of principal component analysis and frequency domain filtering. Then, these templates are fitted into the input signals. The new method enables an observer to examine the variation of the cardiac signal beat-by-beat after a one-time setup period of 20 s. Preliminary in vivo results of two healthy subjects are presented. The results are superior to frequency domain filtering and in good agreement with signals averaged over several cardiac cycles. The method does not depend on ECG or other a priori knowledge. The apparent validity of the method's ability to separate cardiac and pulmonary changes in EIT images was shown and has to be confirmed in future studies. The algorithm opens up new possibilities for future clinical trials on continuous monitoring by means of EIT and for the examination of the relation between the cardiac component and lung perfusion

  15. Nano-liquid chromatography applied to enantiomers separation.

    Science.gov (United States)

    Fanali, Salvatore

    2017-02-24

    This paper presents the state of the art concerning the separation of chiral compounds by means of nano-liquid chromatography (nano-LC). The enantiomers' separation and determination are a subject of fundamental importance in various application fields such as pharmaceutical industry, biomedicine, food, agrochemical etc. Nano-LC is a miniaturized chromatographic technique offering some advantages over conventional ones such as low consumption of mobile phase, sample volume and amount of chiral stationary phase, reduced costs etc. This is reported in the first part of the paper illustrating the features of the nano-LC. In addition, chiral resolution methods are briefly illustrated. Some chiral selectors, used in high-performance liquid chromatography have also been applied in nano-LC including cyclodextrins, glycopeptide antibiotics, modified polysaccharides etc. This is discussed in the second part of the review. Finally some examples of the applications available in literature are reported. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. On the approximation of the limit cycles function

    Directory of Open Access Journals (Sweden)

    L. Cherkas

    2007-11-01

    Full Text Available We consider planar vector fields depending on a real parameter. It is assumed that this vector field has a family of limit cycles which can be described by means of the limit cycles function $l$. We prove a relationship between the multiplicity of a limit cycle of this family and the order of a zero of the limit cycles function. Moreover, we present a procedure to approximate $l(x$, which is based on the Newton scheme applied to the Poincaré function and represents a continuation method. Finally, we demonstrate the effectiveness of the proposed procedure by means of a Liénard system.

  17. EFFICIENCY OF METAL SCRAP SEPARATION IN EDDY CURRENT SEPARATOR

    Directory of Open Access Journals (Sweden)

    Gordan Bedeković

    2008-11-01

    Full Text Available Eddy-current separation is most often method used for the recovery of non-ferrous metals (Al, Cu, Zn, Pb from solid wastes and also for separating non-ferrous metals from each other. The feed material comes to rotary drum and magnetic field by belt conveyer. The changing magnetic field induce eddy currents in conductive (metallic particles. Because interaction between this currents and the magnetic field electrodynamic forces will act on conductive particles. Therefore the trajectories of conductive particles will be different from the trajectories of the non-conductive ones. Separation is a result of the combined actions of several forces (electrodynamic, gravitational and frictional. The paper presents results of aluminium recovery from mixture of metallic particles in eddy current separator. Testing were conducted under field condition. Results shows that is possible achieve recovery of 99 % and concentrate quality of 89 % of aluminium (the paper is published in Croatian.

  18. Polymethylmethacrylate/Polyacrylonitrile Membranes via Centrifugal Spinning as Separator in Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Meltem Yanilmaz

    2015-04-01

    Full Text Available Electrospun nanofiber membranes have been extensively studied as separators in Li-ion batteries due to their large porosity, unique pore structure, and high electrolyte uptake. However, the electrospinning process has some serious drawbacks, such as low spinning rate and high production cost. The centrifugal spinning technique can be used as a fast, cost-effective and safe technique to fabricate high-performance fiber-based separators. In this work, polymethylmethacrylate (PMMA/polyacrylonitrile (PAN membranes with different blend ratios were produced via centrifugal spinning and characterized by using different electrochemical techniques for use as separators in Li-ion batteries. Compared with commercial microporous polyolefin membrane, centrifugally-spun PMMA/PAN membranes had larger ionic conductivity, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. Centrifugally-spun PMMA/PAN membrane separators were assembled into Li/LiFePO4 cells and these cells delivered high capacities and exhibited good cycling performance at room temperature. In addition, cells using centrifugally-spun PMMA/PAN membrane separators showed superior C-rate performance compared to those using microporous polypropylene (PP membranes. It is, therefore, demonstrated that centrifugally-spun PMMA/PAN membranes are promising separator candidate for high-performance Li-ion batteries.

  19. Separation of powers and constitutional loyalty

    Directory of Open Access Journals (Sweden)

    Marieta SAFTA

    2013-06-01

    Full Text Available The complexity and dynamics of political life leads to developments and reconsiderations in terms of classical theories of constitutional law. Such a process occurs also in the case of separation of powers. Many factors have a bearing on how this theory is currently translated into practice, which requires additional perspectives of analysis in order to develop improved models of cooperation and balance of powers, according to new political realities. This study aims at examining the principle of separation and balance of powers in terms of mutual respect and loyal cooperation between institutions, or, in a broader sense, of constitutional loyalty, an intrinsic value-principle of all constitutions, without which no fundamental law, no matter of how democratic it might be, could function properly2. Based on examination of concrete cases drawn from the case-law of the Constitutional Court of Romania, the study demonstrates that, in lack of constitutional loyalty, the objective pursued by enshrining the principle of separation of powers cannot be achieved effectively, i.e. compliance of public authorities and political actors with constitutional provisions is purely formal and the alleged collaboration between them is a "dialogue of the deaf" at the expense of democracy. The seriousness of the consequences of this type of behaviour requires identification of remedies. What are the limits and what solutions can be identified in this regard are questions that also we aim to answer.

  20. Separation of nitrogen-krypton by the freeze-dried cellulose acetate membrane

    International Nuclear Information System (INIS)

    Tanioka, Akihiko; Ishikawa, Kinzo; Kakuta, Akio; Ozaki, Osamu; Oono, Masanori.

    1977-01-01

    The utility of freeze-dried cellulose acetate membranes, which consist of a thin skin layer supported upon a more porous matrix substructure, was examined for separation of nitrogen-radioactive krypton 85. The high permeable and separative membranes were prepared by fixed freezed-drying of swollen membrane after evaporation of acetone for 4-6 minutes. The permeation rate of nitrogen was 10 -1 -10 -3 (cc/cm 2 .sec.atm). Knudsen flow was predominant, since the permeation rate was inversely proportional to square root of molecular weight of gases. The influence of viscous flow was also observed by slight dependence on the pressure. The mean pore size was calculated by the equation of gas permeation in porous media. There exist fine pores of 30-40A radii in the skin layer. The separation factor (dilution of Kr) was about 0.7 and the separation efficiency was 60%. The collision between different gas molecules (Present-de Bethunes' effect) and the influence of viscous flow depreciates the efficiency. The separation efficiency which was determined by the experiment coincided with the one predicted according to the Present-de Bethunes' equation, supposing that the pore size in skin layer was 10-25A. (auth.)

  1. Causal and causally separable processes

    Science.gov (United States)

    Oreshkov, Ognyan; Giarmatzi, Christina

    2016-09-01

    The idea that events are equipped with a partial causal order is central to our understanding of physics in the tested regimes: given two pointlike events A and B, either A is in the causal past of B, B is in the causal past of A, or A and B are space-like separated. Operationally, the meaning of these order relations corresponds to constraints on the possible correlations between experiments performed in the vicinities of the respective events: if A is in the causal past of B, an experimenter at A could signal to an experimenter at B but not the other way around, while if A and B are space-like separated, no signaling is possible in either direction. In the context of a concrete physical theory, the correlations compatible with a given causal configuration may obey further constraints. For instance, space-like correlations in quantum mechanics arise from local measurements on joint quantum states, while time-like correlations are established via quantum channels. Similarly to other variables, however, the causal order of a set of events could be random, and little is understood about the constraints that causality implies in this case. A main difficulty concerns the fact that the order of events can now generally depend on the operations performed at the locations of these events, since, for instance, an operation at A could influence the order in which B and C occur in A’s future. So far, no formal theory of causality compatible with such dynamical causal order has been developed. Apart from being of fundamental interest in the context of inferring causal relations, such a theory is imperative for understanding recent suggestions that the causal order of events in quantum mechanics can be indefinite. Here, we develop such a theory in the general multipartite case. Starting from a background-independent definition of causality, we derive an iteratively formulated canonical decomposition of multipartite causal correlations. For a fixed number of settings and

  2. Causal and causally separable processes

    International Nuclear Information System (INIS)

    Oreshkov, Ognyan; Giarmatzi, Christina

    2016-01-01

    The idea that events are equipped with a partial causal order is central to our understanding of physics in the tested regimes: given two pointlike events A and B , either A is in the causal past of B , B is in the causal past of A , or A and B are space-like separated. Operationally, the meaning of these order relations corresponds to constraints on the possible correlations between experiments performed in the vicinities of the respective events: if A is in the causal past of B , an experimenter at A could signal to an experimenter at B but not the other way around, while if A and B are space-like separated, no signaling is possible in either direction. In the context of a concrete physical theory, the correlations compatible with a given causal configuration may obey further constraints. For instance, space-like correlations in quantum mechanics arise from local measurements on joint quantum states, while time-like correlations are established via quantum channels. Similarly to other variables, however, the causal order of a set of events could be random, and little is understood about the constraints that causality implies in this case. A main difficulty concerns the fact that the order of events can now generally depend on the operations performed at the locations of these events, since, for instance, an operation at A could influence the order in which B and C occur in A ’s future. So far, no formal theory of causality compatible with such dynamical causal order has been developed. Apart from being of fundamental interest in the context of inferring causal relations, such a theory is imperative for understanding recent suggestions that the causal order of events in quantum mechanics can be indefinite. Here, we develop such a theory in the general multipartite case. Starting from a background-independent definition of causality, we derive an iteratively formulated canonical decomposition of multipartite causal correlations. For a fixed number of settings and

  3. Bibliographical study on photochemical separation of uranium isotopes

    International Nuclear Information System (INIS)

    Bougon, Roland

    1975-01-01

    The objective of this report is to propose an overview of knowledge and current works on isotopic separation of uranium by means of selective excitation where this excitation is obtained by a light source with a wave length corresponding to a selective or preferential absorption by a molecule or by the atom itself of one of the isotopes. After a brief overview of principles and requirements of isotopic separation by selective excitation, the author reviews compounds which can be used for this process. These compounds are mainly considered in terms of spectroscopy, and the study focuses on the most volatile among them, the uranium hexafluoride, its spectra, and possible processes for extraction. Some much less volatile uranium compounds are also mentioned with, when available, their spectroscopic properties. The uranium vapour excitation process is described, and some orientations for further researches are proposed [fr

  4. Derivation and precision of mean field electrodynamics with mesoscale fluctuations

    Science.gov (United States)

    Zhou, Hongzhe; Blackman, Eric G.

    2018-06-01

    Mean field electrodynamics (MFE) facilitates practical modelling of secular, large scale properties of astrophysical or laboratory systems with fluctuations. Practitioners commonly assume wide scale separation between mean and fluctuating quantities, to justify equality of ensemble and spatial or temporal averages. Often however, real systems do not exhibit such scale separation. This raises two questions: (I) What are the appropriate generalized equations of MFE in the presence of mesoscale fluctuations? (II) How precise are theoretical predictions from MFE? We address both by first deriving the equations of MFE for different types of averaging, along with mesoscale correction terms that depend on the ratio of averaging scale to variation scale of the mean. We then show that even if these terms are small, predictions of MFE can still have a significant precision error. This error has an intrinsic contribution from the dynamo input parameters and a filtering contribution from differences in the way observations and theory are projected through the measurement kernel. Minimizing the sum of these contributions can produce an optimal scale of averaging that makes the theory maximally precise. The precision error is important to quantify when comparing to observations because it quantifies the resolution of predictive power. We exemplify these principles for galactic dynamos, comment on broader implications, and identify possibilities for further work.

  5. Mean-field theory of active electrolytes: Dynamic adsorption and overscreening

    Science.gov (United States)

    Frydel, Derek; Podgornik, Rudolf

    2018-05-01

    We investigate active electrolytes within the mean-field level of description. The focus is on how the double-layer structure of passive, thermalized charges is affected by active dynamics of constituting ions. One feature of active dynamics is that particles adhere to hard surfaces, regardless of chemical properties of a surface and specifically in complete absence of any chemisorption or physisorption. To carry out the mean-field analysis of the system that is out of equilibrium, we develop the "mean-field simulation" technique, where the simulated system consists of charged parallel sheets moving on a line and obeying active dynamics, with the interaction strength rescaled by the number of sheets. The mean-field limit becomes exact in the limit of an infinite number of movable sheets.

  6. High-temperature method of rapid separation of In-111 from irradiated silver targets

    International Nuclear Information System (INIS)

    Mazgaj, Z.; Kolaczkowski, A.; Mikulski, J.; Novgorodov, A.F.; Zielinski, A.; Joint Inst. for Nuclear Research, Dubna

    1990-01-01

    A high-temperature method of separation of In-111 from α-particle activated silver targets was developed. The separation is carried out under reduced pressure, in the atmosphere of HCl and H 2 O vapours. Indium-111, adsorbed on a quartz collector, is washed out quantitatively with 0.1 N HCl. The contaminant, Cd-109 (product of decay of In-109), is removed from the preparation by means of ion-exchange chromatography. 4 tabs., 6 refs. (author)

  7. Magnetic separation as a plutonium residue enrichment process

    International Nuclear Information System (INIS)

    Avens, L.R.; Gallegos, U.F.; McFarlan, J.T.

    1990-01-01

    Several plutonium contaminated residues have been subjected to Open Gradient Magnetic Separation (OGMS) on an experimental scale. OGMS experiments on graphite and bomb reduction residues resulted in a plutonium rich fraction and a plutonium lean fraction. Values for the bulk quantity rejected to the lean fraction varied between about 20% to 85% of the feed bulk. The plutonium content of the lean fraction can be reduced from about 2% in the feed to the 0.1% to 0.5% range dependent on the portion of the feed rejected to this lean fraction. These values are low enough in plutonium to meet economic discard limits and be considered for direct discard. Magnetic separation of pyrochemical salts gave less favorable results. While a fraction very rich in plutonium could be obtained, the lean fraction plutonium content was too high for direct discard. This may still have chemical processing applications. OGMS experiments at low magnetic field strength on incinerator ash did give two fractions but the plutonium content of each fraction was essentially identical. Thus, no chemical processing advantage was identified for magnetic separation of this residue. 6 refs., 1 fig., 9 tabs

  8. Reverse engineering of inductive fault current limiters

    Energy Technology Data Exchange (ETDEWEB)

    Pina, J M; Neves, M Ventim; Rodrigues, A L [Centre of Technology and Systems Faculdade de Ciencias e Tecnologia, Nova University of Lisbon Monte de Caparica, 2829-516 Caparica (Portugal); Suarez, P; Alvarez, A, E-mail: jmmp@fct.unl.p [' Benito Mahedero' Group of Electrical Applications of Superconductors Escuela de IngenierIas Industrials, University of Extremadura Avenida de Elvas s/n, 06006 Badajoz (Spain)

    2010-06-01

    The inductive fault current limiter is less compact and harder to scale to high voltage networks than the resistive one. Nevertheless, its simple construction and mechanical robustness make it attractive in low voltage grids. Thus, it might be an enabling technology for the advent of microgrids, low voltage networks with dispersed generation, controllable loads and energy storage. A new methodology for reverse engineering of inductive fault current limiters based on the independent analysis of iron cores and HTS cylinders is presented in this paper. Their electromagnetic characteristics are used to predict the devices' hysteresis loops and consequently their dynamic behavior. Previous models based on the separate analysis of the limiters' components were already derived, e.g. in transformer like equivalent models. Nevertheless, the assumptions usually made may limit these models' application, as shown in the paper. The proposed methodology obviates these limitations. Results are validated through simulations.

  9. Reverse engineering of inductive fault current limiters

    International Nuclear Information System (INIS)

    Pina, J M; Neves, M Ventim; Rodrigues, A L; Suarez, P; Alvarez, A

    2010-01-01

    The inductive fault current limiter is less compact and harder to scale to high voltage networks than the resistive one. Nevertheless, its simple construction and mechanical robustness make it attractive in low voltage grids. Thus, it might be an enabling technology for the advent of microgrids, low voltage networks with dispersed generation, controllable loads and energy storage. A new methodology for reverse engineering of inductive fault current limiters based on the independent analysis of iron cores and HTS cylinders is presented in this paper. Their electromagnetic characteristics are used to predict the devices' hysteresis loops and consequently their dynamic behavior. Previous models based on the separate analysis of the limiters' components were already derived, e.g. in transformer like equivalent models. Nevertheless, the assumptions usually made may limit these models' application, as shown in the paper. The proposed methodology obviates these limitations. Results are validated through simulations.

  10. Hydrogen isotope separation experience at the Savannah River Site

    International Nuclear Information System (INIS)

    Lee, M.W.

    1993-01-01

    Savannah River Site (SRS) is a sole producer of tritium for US Weapons Program. SRS has built Facilities, developed the tritium handling processes, and operated safely for the last forty years. Tritium is extracted from the irradiated reactor target, purified, mixed with deuterium, and loaded to the booster gas bottle in the weapon system for limited lifetime. Tritium is recovered from the retired bottle and recycled. Newly produced tritium is branded into the recycled tritium. One of the key process is the hydrogen isotope separation that tritium is separated from deuterium and protium. Several processes have been used for the hydrogen isotope separation at SRS: Thermal Diffusion Column (TD), Batch Cryogenic Still (CS), and Batch Chromatography called Fractional Sorption (FS). TD and CS requires straight vertical columns. The overall system separation factor depends on the length of the column. These are three story building high and difficult to put in glove box. FS is a batch process and slow operation. An improved continuous chromatographic process called Thermal Cycling Absorption Process (TCAP) has been developed. It is small enough to be about to put in a glove box yet high capacity comparable to CS. The SRS tritium purification processes can be directly applicable to the Fusion Fuel Cycle System of the fusion reactor

  11. 34 CFR 300.27 - Limited English proficient.

    Science.gov (United States)

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Limited English proficient. 300.27 Section 300.27... CHILDREN WITH DISABILITIES General Definitions Used in This Part § 300.27 Limited English proficient. Limited English proficient has the meaning given the term in section 9101(25) of the ESEA. (Authority: 20...

  12. Controlling Separation in Turbomachines

    Science.gov (United States)

    Evans, Simon; Himmel, Christoph; Power, Bronwyn; Wakelam, Christian; Xu, Liping; Hynes, Tom; Hodson, Howard

    2010-01-01

    Four examples of flow control: 1) Passive control of LP turbine blades (Laminar separation control). 2) Aspiration of a conventional axial compressor blade (Turbulent separation control). 3) Compressor blade designed for aspiration (Turbulent separation control). 4.Control of intakes in crosswinds (Turbulent separation control).

  13. Precipitation phase separation schemes in the Naqu River basin, eastern Tibetan plateau

    Science.gov (United States)

    Liu, Shaohua; Yan, Denghua; Qin, Tianling; Weng, Baisha; Lu, Yajing; Dong, Guoqiang; Gong, Boya

    2018-01-01

    Precipitation phase has a profound influence on the hydrological processes in the Naqu River basin, eastern Tibetan plateau. However, there are only six meteorological stations with precipitation phase (rainfall/snowfall/sleet) before 1979 within and around the basin. In order to separate snowfall from precipitation, a new separation scheme with S-shaped curve of snowfall proportion as an exponential function of daily mean temperature was developed. The determinations of critical temperatures in the single/two temperature threshold (STT/TTT2) methods were explored accordingly, and the temperature corresponding to the 50 % snowfall proportion (SP50 temperature) is an efficiently critical temperature for the STT, and two critical temperatures in TTT2 can be determined based on the exponential function and SP50 temperature. Then, different separation schemes were evaluated in separating snowfall from precipitation in the Naqu River basin. The results show that the S-shaped curve methods outperform other separation schemes. Although the STT and TTT2 slightly underestimate and overestimate the snowfall when the temperature is higher and colder than SP50 temperature respectively, the monthly and annual separation snowfalls are generally consistent with the observed snowfalls. On the whole, S-shaped curve methods, STT, and TTT2 perform well in separating snowfall from precipitation with the Pearson correlation coefficient of annual separation snowfall above 0.8 and provide possible approaches to separate the snowfall from precipitation for hydrological modelling.

  14. Separation of niobium and tantalum by paper chromatography and their following spectrographic determination

    International Nuclear Information System (INIS)

    Moroshkina, T.M.; Peres Sanfiel', F.

    1975-01-01

    The paper presents the results of an investigation into the use of water-saturated furfural to separate niobium and tantalum in a 1:1 ratio by means of ascending paper chromatography. The influence of sulphuric acid, ammonium fluoride and hydrofluoric acid concentrations on the completeness of the niobium and tantalum separation was investigated, the extent of the separation being checked by a spectral method. The results indicate that the use of furfural creates favourable conditions for niobium and tantalum separation. The purest tantalum is obtained at concentrations of sulphuric acid 600 k/l, hydrofluoric acid 4.6% and ammonium fluoride 30 g/l. To obtain pure niobium the acid concentrations remain the same but the quantity of ammonium fluoride is doubled. The fluoride ion concentration has a significant effect on the completeness of niobium and tantalum separation. The variation coefficient for the niobium determination is 14%, for the tantalum determination 1O% (author)

  15. Solitons and separable elliptic solutions of the sine-Gordon equation

    International Nuclear Information System (INIS)

    Bryan, A.C.; Haines, C.R.; Stuart, A.E.G.

    1979-01-01

    It is pointed out that the two-soliton (antisoliton) solutions of the sine-Gordon equation may be obtained as limiting cases of a separable, two-parameter family of elliptic solutions. The solitons are found on the boundary of the parameter space for the elliptic solutions when the latter are considered over their usual complex domain. (Auth.)

  16. A NOVEL METHOD OF THE HYDRIDE SEPARATION FOR THE DETERMINATION OF ARSENIC AND ANTIMONY BY AAS

    Directory of Open Access Journals (Sweden)

    Ganden Supriyanto

    2010-06-01

    Full Text Available A novel method is proposed for the hydride separation when determinining of arsenic and antimony by AAS. A chromatomembrane cell was used as preconcentration-, extraction- and separation-manifold instead of the U-tube phase separator, which is normally fitted in continuous flow vapour systems generating conventionaly the hydrides. The absorbances of the hydrides produced were measured by an atomic absorption spectrophotometer at 193.7 nm and 217.6 nm. Under optimized analytical conditions, the calibration plot for arsenic was linear from 50 to 500 ng.mL-1 (r2 = 0.9982. The precision for three subsequent measurements of 500 ng.mL-1 arsenic gave rise to a relative standard deviation of 0.4%. The detection limit was 15 ng.mL-1, which is much lower compared with that of the conventional hydride system (2000 ng.mL-1. A similar result was observed in case of antimony: the detection limit was 8 ng.mL-1 when the proposed method was applied. Consequently, the sensitivity of the novel method surpasses systems with conventional hydride generation, i.e. the precision and the acuracy increase whereas the standard deviation and the detection limit decrease. The proposed method was applied in pharmacheutial analysis and the certified As-content of a commercial product was very sufficiently confirmed.   Keywords: Chromatomembrane Cell, Hydride separation, Arsenic detection, Antimony detection, AAS

  17. Advanced isotope separation

    International Nuclear Information System (INIS)

    1982-01-01

    The Study Group briefly reviewed the technical status of the three Advanced Isotope Separation (AIS) processes. It also reviewed the evaluation work that has been carried out by DOE's Process Evaluation Board (PEB) and the Union Carbide Corporation-Nuclear Division (UCCND). The Study Group briefly reviewed a recent draft assessment made for DOE staff of the nonproliferation implications of the AIS technologies. The staff also very briefly summarized the status of GCEP and Advanced Centrifuge development. The Study Group concluded that: (1) there has not been sufficient progress to provide a firm scientific, technical or economic basis on which to select one of the three competing AIS processes for full-scale engineering development at this time; and (2) however, should budgetary restraints or other factors force such a selection, we believe that the evaluation process that is being carried out by the PEB provides the best basis available for making a decision. The Study Group recommended that: (1) any decisions on AIS processes should include a comparison with gas centrifuge processes, and should not be made independently from the plutonium isotope program; (2) in evaluating the various enrichment processes, all applicable costs (including R and D and sales overhead) and an appropriate discounting approach should be included in order to make comparisons on a private industry basis; (3) if the three AIS programs continue with limited resources, the work should be reoriented to focus only on the most pressing technical problems; and (4) if a decision is made to develop the Atomic Vapor Laser Isotope Separation process, the solid collector option should be pursued in parallel to alleviate the potential program impact of liquid collector thermal control problems

  18. Evaluation of the performance of thermal diffusion column separating binary gas mixtures with continuous draw-off

    International Nuclear Information System (INIS)

    Kitamoto, Asashi; Shimizu, Masami; Takashima, Yoichi

    1977-01-01

    Advanced transport relations involving three column constants, H sup(σ), K sub(c)sup(σ) and K sub(d)sup(σ), are developed to describe the separation performance of a thermal diffusion column with continuous draw-off. These constants were related to some integral functions of velocity profile, temperature distribution, density of gas mixture and characteristic values of transport coefficients. The separation of binary gas mixture by this technique was so effective that three reasonable factors had to be introduced into the column constants in the theory. They are a circulation constant of natural convection, a definition of characteristic mean temperature and a definition of mean composition over the column. The separation performance and the column constants also varied with the distortion of velocity profile due to continuous draw-off from the top or the bottom of column. However, its effect was not large, compared with the other factors mentioned above. The theory presented here makes possible to estimate the separation performance of hot-wire type thermal diffusion column with high accuracy. (auth.)

  19. Inlet Diameter and Flow Volume Effects on Separation and Energy Efficiency of Hydrocyclones

    Science.gov (United States)

    Erikli, Ş.; Olcay, A. B.

    2015-08-01

    This study investigates hydrocyclone performance of an oil injected screw compressor. Especially, the oil separation efficiency of a screw compressor plays a significant role for air quality and non-stop working hour of compressors has become an important issue when the efficiency in energy is considered. In this study, two separation efficiency parameters were selected to be hydrocyclone inlet diameter and flow volume height between oil reservoir surface and top of the hydrocyclone. Nine different cases were studied in which cyclone inlet diameter and flow volume height between oil reservoir surface and top were investigated in regards to separation and energy performance aspects and the effect of the parameters on the general performance appears to be causing powerful influence. Flow inside the hydrocyclone geometry was modelled by Reynolds Stress Model (RSM) and hydro particles were tracked by Discrete Phase Model (DPM). Besides, particle break up was modelled by the Taylor Analogy Breakup (TAB) model. The reversed vortex generation was observed at different planes. The upper limit of the inlet diameter of the cyclone yields the centrifugal force on particles to decrease while the flow becomes slower; and the larger diameter implies slower flow. On the contrary, the lower limit is increment in speed causes breakup problems that the particle diameters become smaller; consequently, it is harder to separate them from gas.

  20. The Dynamics of Controlled Flow Separation within a Diverter Duct Diffuser

    Science.gov (United States)

    Peterson, C. J.; Vukasinovic, B.; Glezer, A.

    2016-11-01

    The evolution and receptivity to fluidic actuation of the flow separation within a rectangular, constant-width, diffuser that is branched off of a primary channel is investigated experimentally at speeds up to M = 0.4. The coupling between the diffuser's adverse pressure gradient and the internal separation that constricts nearly half of the flow passage through the duct is controlled using a spanwise array of fluidic actuators on the surface upstream of the diffuser's inlet plane. The dynamics of the separating surface vorticity layer in the absence and presence of actuation are investigated using high-speed particle image velocimetry combined with surface pressure measurements and total pressure distributions at the primary channel's exit plane. It is shown that the actuation significantly alters the incipient dynamics of the separating vorticity layer as the characteristic cross stream scales of the boundary layer upstream of separation and of the ensuing vorticity concentrations within the separated flow increase progressively with actuation level. It is argued that the dissipative (high frequency) actuation alters the balance between large- and small-scale motions near separation by intensifying the large-scale motions and limiting the small-scale dynamics. Controlling separation within the diffuser duct also has a profound effect on the global flow. In the presence of actuation, the mass flow rate in the primary duct increases 10% while the fraction of the diverted mass flow rate in the diffuser increases by more than 45% at 0.7% actuation mass fraction. Supported by the Boeing Company.

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

    Science.gov (United States)

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

    2013-11-05

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

  2. Institute for separation chemistry of Marcoule I.C.S.M; Institut de chimie separative de Marcoule I.C.S.M

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Institute for Separation Chemistry was created in March 2007, and the building including laboratory and offices will be opened to scientists and technicians the middle of 2008. Since resources in Uranium are scarce and wastes related to nuclear energy production are potentially dangerous, the chemistry associated to nuclear energy production always followed the principles of green chemistry: close the life-cycle of material and fuel, minimize wastes and ascertain the acceptability by a society via knowledge of chemistry and physical chemistry involved in processes. The Institute is devoted to chemistry at the service of the nuclear energy of the future, seen as an actor for sustainable development compatible with limited resources and chemical preservation of the atmosphere. Progresses in fundamental research, based on publication and education of students, engineers and young scientists, will be focused along seven identified directions, devoted to scattering and diffraction, microscopies and mainly mesoscopic modelling. The goals of the teams are described in this booklet, describing activities of the 28 scientists since two years. Separation chemistry, a branch of physical chemistry, is a key actor in 'green chemistry'. Nano-science and physical chemistry, at the roots of modern chemistry considering also non-covalent and long-range interactions, need to be included along the 'tools' involved in new processes. Three axis of research will be privileged: initial steps of separation, via dissolution by sono-chemical means, ion separation via colloids and complex fluids, and maintaining the separation between species involving self-repairing nano-materials, once the evolution of the interface fed from the evolving interface has been modelled. Eleven permanent staff scientists are already active since a few months on average at ICSM at the date of this report (5 CEA, 2 Universities and 4 CNRS). Teaching, scientific animation, summer schools and

  3. Comparison of Liquid Limit of Highly Plastic Clay by Means of Casagrande and Fall Cone Apparatus

    DEFF Research Database (Denmark)

    Grønbech, Gitte Lyng; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2011-01-01

    The connection between the Liquid Limit found using the Casagrande and the Fall Cone Apparatus is tested for the Danish Eocene Clay that has Liquid Limits up to 350% and Plasticity Index up to 300%, which is well outside the normal range of Casagrande’s Plasticity Chart. Based on the high plastic...

  4. Component separation in harmonically trapped boson-fermion mixtures

    DEFF Research Database (Denmark)

    Nygaard, Nicolai; Mølmer, Klaus

    1999-01-01

    We present a numerical study of mixed boson-fermion systems at zero temperature in isotropic and anise tropic harmonic traps. We investigate the phenomenon of component separation as a function of the strength ut the interparticle interaction. While solving a Gross-Pitaevskii mean-field equation ...... for the boson distribution in the trap, we utilize two different methods to extract the density profile of the fermion component; a semiclassical Thomas-Fermi approximation and a quantum-mechanical Slater determinant Schrodinger equation....

  5. MULTI-K: accurate classification of microarray subtypes using ensemble k-means clustering

    Directory of Open Access Journals (Sweden)

    Ashlock Daniel

    2009-08-01

    Full Text Available Abstract Background Uncovering subtypes of disease from microarray samples has important clinical implications such as survival time and sensitivity of individual patients to specific therapies. Unsupervised clustering methods have been used to classify this type of data. However, most existing methods focus on clusters with compact shapes and do not reflect the geometric complexity of the high dimensional microarray clusters, which limits their performance. Results We present a cluster-number-based ensemble clustering algorithm, called MULTI-K, for microarray sample classification, which demonstrates remarkable accuracy. The method amalgamates multiple k-means runs by varying the number of clusters and identifies clusters that manifest the most robust co-memberships of elements. In addition to the original algorithm, we newly devised the entropy-plot to control the separation of singletons or small clusters. MULTI-K, unlike the simple k-means or other widely used methods, was able to capture clusters with complex and high-dimensional structures accurately. MULTI-K outperformed other methods including a recently developed ensemble clustering algorithm in tests with five simulated and eight real gene-expression data sets. Conclusion The geometric complexity of clusters should be taken into account for accurate classification of microarray data, and ensemble clustering applied to the number of clusters tackles the problem very well. The C++ code and the data sets tested are available from the authors.

  6. MULTI-K: accurate classification of microarray subtypes using ensemble k-means clustering.

    Science.gov (United States)

    Kim, Eun-Youn; Kim, Seon-Young; Ashlock, Daniel; Nam, Dougu

    2009-08-22

    Uncovering subtypes of disease from microarray samples has important clinical implications such as survival time and sensitivity of individual patients to specific therapies. Unsupervised clustering methods have been used to classify this type of data. However, most existing methods focus on clusters with compact shapes and do not reflect the geometric complexity of the high dimensional microarray clusters, which limits their performance. We present a cluster-number-based ensemble clustering algorithm, called MULTI-K, for microarray sample classification, which demonstrates remarkable accuracy. The method amalgamates multiple k-means runs by varying the number of clusters and identifies clusters that manifest the most robust co-memberships of elements. In addition to the original algorithm, we newly devised the entropy-plot to control the separation of singletons or small clusters. MULTI-K, unlike the simple k-means or other widely used methods, was able to capture clusters with complex and high-dimensional structures accurately. MULTI-K outperformed other methods including a recently developed ensemble clustering algorithm in tests with five simulated and eight real gene-expression data sets. The geometric complexity of clusters should be taken into account for accurate classification of microarray data, and ensemble clustering applied to the number of clusters tackles the problem very well. The C++ code and the data sets tested are available from the authors.

  7. Neutron-skin thickness of finite nuclei in relativistic mean-field models with chiral limits

    International Nuclear Information System (INIS)

    Jiang Weizhou; Li Baoan; Chen Liewen

    2007-01-01

    We study several structure properties of finite nuclei using relativistic mean-field Lagrangians constructed according to the Brown-Rho scaling due to the chiral symmetry restoration at high densities. The models are consistent with current experimental constraints for the equations of state of symmetric matter at both normal and supranormal densities and of asymmetric matter at subsaturation densities. It is shown that these models can successfully describe the binding energies and charge radii of finite nuclei. Compared to calculations with usual relativistic mean-field models, these models give a reduced thickness of neutron skin in 208 Pb between 0.17 fm and 0.21 fm. The reduction of the predicted neutron skin thickness is found to be due to not only the softening of the symmetry energy but also the scaling property of ρ meson required by the partial restoration of chiral symmetry

  8. Efficacy of Substance Removal by Immunoadsorption With a Selective Plasma Separator.

    Science.gov (United States)

    Hanafusa, Norio; Yamamoto, Hiroko; Tamachi, Masaki; Torato, Toshihiro; Sakurai, Satoko; Tsuchiya, Ken; Nitta, Kosaku; Nangaku, Masaomi

    2017-06-01

    Immunoadsorption with a tryptophan-conjugated column has a limited capacity and reduces fibrinogen. We speculated that immunoadsorption with a selective plasma separator has higher efficiency in removing immunoglobulins than ordinary immunoadsorption without affecting coagulation factors. This study investigated the efficacy of immunoadsorption with a selective plasma separator in vitro. The sieving coefficients, the pool concentration, and the adsorbed amount were investigated serially with up to 5 L of processed plasma. The sieving coefficients of the selective plasma separator were 0.8, 0.5, and 0.1 for albumin, immunoglobulin G (IgG), and factor 13, respectively. The trend of concentrations for the ordinary plasma separator in the pool reached its nadir at 1.5 L and 3.5 L of plasma processed for IgG, IgG1, or IgG2, and IgG3, respectively. However, the volume was doubled for the selective plasma separator. The trends of fibrinogen and factor 13 concentrations differed significantly between two plasma separators. The trends of the absorbed amount were mirror images of the concentration in the pool. Comparison of the peak amount absorbed indicated that the amounts were almost identical between the two separators for IgG, IgG1, and IgG2. On the other hand, the peak amounts were less for albumin, fibrinogen, and IgG3 with the selective plasma separator than with the ordinary separator. Although further investigations about bradykinin are required, immunoadsorption with the selective plasma separator supports the administration of more frequent and intensive treatments to remove IgG1 or IgG2 without affecting coagulation factors. © 2017 International Society for Apheresis, Japanese Society for Apheresis, and Japanese Society for Dialysis Therapy.

  9. The State and the separation of powers

    Directory of Open Access Journals (Sweden)

    Catalin-Silviu Sararu

    2015-12-01

    Full Text Available The State is a complex concept that can be addressed from a legal, political, social and economic perspective. The paper explores the meanings of the concept of State, State elements and stresses that the State power is one and indivisible and it is exercised through three functions and not to separate powers, namely the legislative function, executive function and the judicial function. The State institutions through which the three functions are controlled each other and collaborate to achieve the needs of society, which is likely to prevent abuses against citizens.

  10. Quantifying the resolution level where the GRACE satellites can separate Greenland's glacial mass balance from surface mass balance

    Science.gov (United States)

    Bonin, J. A.; Chambers, D. P.

    2015-09-01

    Mass change over Greenland can be caused by either changes in the glacial dynamic mass balance (DMB) or the surface mass balance (SMB). The GRACE satellite gravity mission cannot directly separate the two physical causes because it measures the sum of the entire mass column with limited spatial resolution. We demonstrate one theoretical way to indirectly separate cumulative SMB from DMB with GRACE, using a least squares inversion technique with knowledge of the location of the glaciers. However, we find that the limited 60 × 60 spherical harmonic representation of current GRACE data does not provide sufficient resolution to adequately accomplish the task. We determine that at a maximum degree/order of 90 × 90 or above, a noise-free gravity measurement could theoretically separate the SMB from DMB signals. However, current GRACE satellite errors are too large at present to separate the signals. A noise reduction of a factor of 10 at a resolution of 90 × 90 would provide the accuracy needed for the interannual cumulative SMB and DMB to be accurately separated.

  11. Rule of thumb for binary isotope separations in a gas centrifuge

    International Nuclear Information System (INIS)

    Berger, M.H.

    1985-12-01

    A very simple hypothetical model of the binary isotope separation process in a countercurrent Gas Centrifuge is proposed. Like the usual Cohen-Onsager separation theory it involves the internal fluid dynamics, but unlike the usual isotopic separation theory it completely obviates the usual flow integrals for Cohen's E. Thereby allowing an immediate estimate of the flow efficiency of a given design, which can and sometimes should be checked later by the usual analyses. To shed some light on our idea, two simple derivations for assumed idealized hydrodynamics are given, but a rigorous proof remains an open question. Then our hypothesis is tested against a battery of about 10 new ''exact'' formulas for E based upon analytical solutions to several variants of Onsager's pancake equation and found to be ''reasonably'' accurate and surprisingly robust. Finally, some limitations of our rule are explored

  12. A Joint Approach for Single-Channel Speaker Identification and Speech Separation

    DEFF Research Database (Denmark)

    Mowlaee, Pejman; Saeidi, Rahim; Christensen, Mads Græsbøll

    2012-01-01

    ) accuracy, here, we report the objective and subjective results as well. The results show that the proposed system performs as well as the best of the state-of-the-art in terms of perceived quality while its performance in terms of speaker identification and automatic speech recognition results......In this paper, we present a novel system for joint speaker identification and speech separation. For speaker identification a single-channel speaker identification algorithm is proposed which provides an estimate of signal-to-signal ratio (SSR) as a by-product. For speech separation, we propose...... a sinusoidal model-based algorithm. The speech separation algorithm consists of a double-talk/single-talk detector followed by a minimum mean square error estimator of sinusoidal parameters for finding optimal codevectors from pre-trained speaker codebooks. In evaluating the proposed system, we start from...

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

    Directory of Open Access Journals (Sweden)

    Sabine Walper

    2015-10-01

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

  14. Innovative oxide materials for electrochemical energy conversion and oxygen separation

    Science.gov (United States)

    Belousov, V. V.

    2017-10-01

    Ion-conducting solid metal oxides are widely used in high-temperature electrochemical devices for energy conversion and oxygen separation. However, liquid metal oxides possessing unique electrochemical properties still remain of limited use. The review demonstrates the potential for practical applications of molten oxides. The transport properties of molten oxide materials are discussed. The emphasis is placed on the chemical diffusion of oxygen in the molten oxide membrane materials for electrochemical energy conversion and oxygen separation. The thermodynamics of these materials is considered. The dynamic polymer chain model developed to describe the oxygen ion transport in molten oxides is discussed. Prospects for further research into molten oxide materials are outlined. The bibliography includes 145 references.

  15. Separable algebras

    CERN Document Server

    Ford, Timothy J

    2017-01-01

    This book presents a comprehensive introduction to the theory of separable algebras over commutative rings. After a thorough introduction to the general theory, the fundamental roles played by separable algebras are explored. For example, Azumaya algebras, the henselization of local rings, and Galois theory are rigorously introduced and treated. Interwoven throughout these applications is the important notion of étale algebras. Essential connections are drawn between the theory of separable algebras and Morita theory, the theory of faithfully flat descent, cohomology, derivations, differentials, reflexive lattices, maximal orders, and class groups. The text is accessible to graduate students who have finished a first course in algebra, and it includes necessary foundational material, useful exercises, and many nontrivial examples.

  16. Determination of phosphorus in metals by neutron activation and chemical separation as hydride

    International Nuclear Information System (INIS)

    Rouchaud, J.C.; Fedoroff, M.

    1993-01-01

    Phosphorous at trace levels alters the properties of metals and alloys. Its determination was investigated by radiochemical neutron activation analysis. Separation by solvent extraction or by evolution as P 0 showed to be neither selective nor quantitative in presence of a metallic matrix. Therefore, a new method of separation by reduction to phosphorous hydride followed by liquid scintillation counting was investigated. This method is quantitative in the case of non-radioactive iron doped with radioactive phosphorus. At present, the separation is not quantitative for irradiation iron samples, owing probably to hot atom or radiation effects. A detection limit of 0.002 μg is expected. (author) 10 refs.; 1 fig.; 3 tabs

  17. Magnetic shielding of a limiter

    International Nuclear Information System (INIS)

    Brevnov, N.N.; Stepanov, S.B.; Khimchenko, L.N.; Matthews, G.F.; Goodal, D.H.J.

    1991-01-01

    Localization of plasma interaction with material surfaces in a separate chamber, from where the escape of impurities is hardly realized, i.e. application of magnetic divertors or pump limiters, is the main technique for reduction of the impurity content in a plasma. In this case, the production of a divertor configuration requires a considerable power consumption and results in a less effective utilization of the magnetic field volume. Utilization of a pump limiter, for example the ICL-type, under tokamak-reactor conditions would result in the extremely high and forbidden local heat loadings onto the limiter surface. Moreover, the magnetically-shielded pump limiter (MSL) was proposed to combine positive properties of the divertor and the pump limiter. The idea of magnetic shielding is to locate the winding with current inside the limiter head so that the field lines of the resultant magnetic field do not intercept the limiter surface. In this case the plasma flows around the limiter leading edges and penetrates into the space under the limiter. The shielding magnetic field can be directed either counter the toroidal field or counter the poloidal one of a tokamak, dependent on the concrete diagram of the device. Such a limiter has a number of advantages: -opportunity to control over the particle and impurity recycling without practical influence upon the plasma column geometry, - perturbation of a plasma column magnetic configuration from the side of such a limiter is less than that from the side of the divertor coils. The main deficiency is the necessity to locate active windings inside the discharge chamber. (author) 5 refs., 3 figs

  18. Atmospheric pressure surface sampling/ionization techniques for direct coupling of planar separations with mass spectrometry.

    Science.gov (United States)

    Pasilis, Sofie P; Van Berkel, Gary J

    2010-06-18

    Planar separations, which include thin layer chromatography and gel electrophoresis, are in widespread use as important and powerful tools for conducting separations of complex mixtures. To increase the utility of planar separations, new methods are needed that allow in situ characterization of the individual components of the separated mixtures. A large number of atmospheric pressure surface sampling and ionization techniques for use with mass spectrometry have emerged in the past several years, and several have been investigated as a means for mass spectrometric read-out of planar separations. In this article, we review the atmospheric pressure surface sampling and ionization techniques that have been used for the read-out of planar separation media. For each technique, we briefly explain the operational basics and discuss the analyte type for which it is appropriate and some specific applications from the literature. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  19. Source separation of household waste: A case study in China

    International Nuclear Information System (INIS)

    Zhuang Ying; Wu Songwei; Wang Yunlong; Wu Weixiang; Chen Yingxu

    2008-01-01

    A pilot program concerning source separation of household waste was launched in Hangzhou, capital city of Zhejiang province, China. Detailed investigations on the composition and properties of household waste in the experimental communities revealed that high water content and high percentage of food waste are the main limiting factors in the recovery of recyclables, especially paper from household waste, and the main contributors to the high cost and low efficiency of waste disposal. On the basis of the investigation, a novel source separation method, according to which household waste was classified as food waste, dry waste and harmful waste, was proposed and performed in four selected communities. In addition, a corresponding household waste management system that involves all stakeholders, a recovery system and a mechanical dehydration system for food waste were constituted to promote source separation activity. Performances and the questionnaire survey results showed that the active support and investment of a real estate company and a community residential committee play important roles in enhancing public participation and awareness of the importance of waste source separation. In comparison with the conventional mixed collection and transportation system of household waste, the established source separation and management system is cost-effective. It could be extended to the entire city and used by other cities in China as a source of reference

  20. Real-time reactor coolant system pressure/temperature limit system

    International Nuclear Information System (INIS)

    Newton, D.G.; Schemmel, R.R.; Van Scooter, W.E. Jr.

    1991-01-01

    This patent describes an system, used in controlling the operating of a nuclear reactor coolant system, which automatically calculates and displays allowable reactor coolant system pressure/temperature limits within the nuclear reactor coolant system based upon real-time inputs. It comprises: means for producing signals representative of real-time operating parameters of the nuclear reactor cooling system; means for developing pressure and temperature limits relating the real-time operating parameters of the nuclear reactor coolant system, for normal and emergency operation thereof; means for processing the signals representative of real-time operating parameters of the nuclear reactor coolant system to perform calculations of a best estimate of signals, check manual inputs against permissible valves and test data acquisition hardware for validity and over/under range; and means for comparing the representative signals with limits for the real-time operating parameters to produce a signal for a real-time display of the pressure and temperature limits and of the real-time operating parameters use an operator in controlling the operation of the nuclear reactor coolant system

  1. Mean-Gini Portfolio Analysis: A Pedagogic Illustration

    Directory of Open Access Journals (Sweden)

    C. Sherman Cheung

    2007-05-01

    Full Text Available It is well known in the finance literature that mean-variance analysis is inappropriate when asset returns are not normally distributed or investors’ preferences of returns are not characterized by quadratic functions. The normality assumption has been widely rejected in cases of emerging market equities and hedge funds. The mean-Gini framework is an attractive alternative as it is consistent with stochastic dominance rules regardless of the probability distributions of asset returns. Applying mean-Gini to a portfolio setting involving multiple assets, however, has always been challenging to business students whose training in optimization is limited. This paper introduces a simple spreadsheet-based approach to mean-Gini portfolio optimization, thus allowing the mean-Gini concepts to be covered more effectively in finance courses such as portfolio theory and investment analysis.

  2. TFTR movable limiter instrumentation and controls

    International Nuclear Information System (INIS)

    Frankenberg, J.; Collins, D.; Kaufmann, D.; Mamoun, A.

    1983-01-01

    The TFTR movable limiter is a single poloidal limiter located within one 18 /SUP o/ segment of the vacuum vessel. It consists of three (3) interconnected inconel backing plates covered with titanium carbide coated graphite tiles. The backing plates are positioned by three independent screw drive actuators. Cooling water is fed through the horizontal port cover to tubes brazed onto the backs of the backing plates. Thermocouples monitor the limiter temperature. (1) and more fully described in refs. (1) and (2). The positioning actuators are driven by independently controlled DC servo motors, controlled either locally or from CICADA. Drive motor shaft position is monitored by chain driven encoders and potentiometers. Limiter blade position can be varied to suit any plasma within the operating range. CICADA is programmed to keep the limiter stroke within safe operating limits. A microprocessor duplicates the CICADA protective function allowing limiter operation without CICADA. The potentiometer signal is sent to an analog computer, which safeguards the limiter against failure of the encoders or the micro-processor. Cooling water flows through the limiter in 3 separate paths, one for each blade. The flow rate and temperature rise through each loop are measured accurately to allow CICADA to calculate the heat into each blade. The water system is also interlocked and alarmed to prevent dumping of water into the vacuum vessel

  3. Hydrogen separation process

    Science.gov (United States)

    Mundschau, Michael [Longmont, CO; Xie, Xiaobing [Foster City, CA; Evenson, IV, Carl; Grimmer, Paul [Longmont, CO; Wright, Harold [Longmont, CO

    2011-05-24

    A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to a hydrogen separation membrane system comprising a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for separating a hydrogen-rich product stream from a feed stream comprising hydrogen and at least one carbon-containing gas, comprising feeding the feed stream, at an inlet pressure greater than atmospheric pressure and a temperature greater than 200.degree. C., to an integrated water gas shift/hydrogen separation membrane system wherein the hydrogen separation membrane system comprises a membrane that is selectively permeable to hydrogen, and producing a hydrogen-rich permeate product stream on the permeate side of the membrane and a carbon dioxide-rich product raffinate stream on the raffinate side of the membrane. A method for pretreating a membrane, comprising: heating the membrane to a desired operating temperature and desired feed pressure in a flow of inert gas for a sufficient time to cause the membrane to mechanically deform; decreasing the feed pressure to approximately ambient pressure; and optionally, flowing an oxidizing agent across the membrane before, during, or after deformation of the membrane. A method of supporting a hydrogen separation membrane system comprising selecting a hydrogen separation membrane system comprising one or more catalyst outer layers deposited on a hydrogen transport membrane layer and sealing the hydrogen separation membrane system to a porous support.

  4. Generalized quantum mean-field systems and their application to ultracold atoms

    International Nuclear Information System (INIS)

    Trimborn-Witthaut, Friederike Annemarie

    2011-01-01

    Strongly interacting many-body systems consisting of a large number of indistinguishable particles play an important role in many areas of physics. Though such systems are hard to deal with theoretically since the dimension of the respective Hilbert space increases exponentially both in the particle number and in the number of system modes. Therefore, approximations are of considerable interest. The mean-field approximation describes the behaviour in the macroscopic limit N→∞, which leads to an effective nonlinear single-particle problem. Although this approximation is widely used, rigorous results on the applicability and especially on finite size corrections are extremely rare. One prominent example of strongly interacting many-body systems are ultracold atoms in optical lattices, which are a major subject of this thesis. Typically these systems consist of a large but well-defined number of particles, such that corrections to the mean-field limit can be systematically studied. This thesis is divided into two parts: In the first part we study generalized quantum mean-field systems in a C * -algebraic framework. These systems are characterized by their intrinsic permutation symmetry. In the limit of infinite system size, N→∞, the intensive observables converge to the commutative algebra of weak * -continuous functions on the single particle state space. To quantify the deviations from the meanfield prediction for large but finite N, we establish a differential calculus for state space functions and provide a generalized Taylor expansion around the mean-field limit. Furthermore, we introduce the algebra of macroscopic fluctuations around the mean-field limit and prove a quantum version of the central limit theorem. On the basis of these results, we give a detailed study of the finite size corrections to the ground state energy and establish bounds, for both the quantum and the classical case. Finally, we restrict ourselves to the subspace of Bose

  5. Accuracy and Radiation Dose Reduction of Limited-Range CT in the Evaluation of Acute Appendicitis in Pediatric Patients.

    Science.gov (United States)

    Jin, Michael; Sanchez, Thomas R; Lamba, Ramit; Fananapazir, Ghaneh; Corwin, Michael T

    2017-09-01

    The purpose of this article is to determine the accuracy and radiation dose reduction of limited-range CT prescribed from the top of L2 to the top of the pubic symphysis in children with suspected acute appendicitis. We performed a retrospective study of 210 consecutive pediatric patients from December 11, 2012, through December 11, 2014, who underwent abdominopelvic CT for suspected acute appendicitis. Two radiologists independently reviewed the theoretic limited scans from the superior L2 vertebral body to the top of the pubic symphysis, to assess for visualization of the appendix, acute appendicitis, alternative diagnoses, and incidental findings. Separately, the same parameters were assessed on the full scan by the same two reviewers. Whole-body effective doses were determined for the full- and limited-range scans and were compared using the paired t test. The appendix or entire cecum was visualized on the limited scan in all cases, and no cases of acute appendicitis were missed on the simulated limited scan compared with the full scan. Two alternative diagnoses were missed with the limited scan: one case of hydronephrosis and one of acute acalculous cholecystitis. The mean effective dose for the original scan was 5.6 mSv and that for the simulated limited scan was 3.0 mSv, resulting in a dose reduction of 46.4% (p appendicitis and reduces the dose by approximately 46%.

  6. Towards a fully printable battery: robocast deposition of separators

    International Nuclear Information System (INIS)

    Atanassov, Plamen Borissov; Fenton, Kyle Ross; Apblett, Christopher Alan

    2010-01-01

    The development of thin batteries has presented several interesting problems which are not seen in traditional battery sizes. As the size of a battery reaches a minimum, the usable capacity of the battery decreases due to the fact that the major constituent of the battery becomes the package and separator. As the size decreases, the volumetric contribution from the package and separator increases. This can result in a reduction of capacity from these types of batteries of nearly all of the available power. The development of a method for directly printing the battery layers, including the package, in place would help to alleviate this problem. The technology used in this paper to directly print battery components is known as robocasting and is capable of direct writing of slurries in complex geometries. This method is also capable of conformally printing on three dimensional surfaces, opening up the possibility of novel batteries based on tailoring battery footprints to conform to the available substrate geometry. Interfacial resistance can also be reduced by using the direct write method. Each layer is printed in place on the battery stack instead of being stacked one at a time. This ensures an intimate contact and seal at every interface within the cell. By limiting the resistance at these interfaces, we effectively help increase the useable capacity of our battery through increase transport capability. We have developed methodology for printing several different separator materials for use in a lithium cell. When combined with a printable cathode comprised of LiFePO 4 (as seen in Figure 1) and a lithium anode, our battery is capable of delivering a theoretical capacity of 170 mAh g -1 . This capacity is diminished by transport phenomena within the cell which limit the transport rate of the lithium ions during the discharge cycle. The material set chosen for the printable separator closely resemble those used in commercially available separators in order to keep

  7. A consistent multigroup model for radiative transfer and its underlying mean opacities

    International Nuclear Information System (INIS)

    Turpault, Rodolphe

    2005-01-01

    In some regimes, such as in plasma physics or in super orbital atmospheric entry of space objects, the effects of radiation are crucial and can tremendously modify the hydrodynamics of the gas. In such cases, it is therefore important to have a good prediction of the radiative variables. However, full transport solutions of these multi-dimensional, time-dependent problems are too expensive to get to be involved in a coupled configuration. It is hence necessary to develop other models for radiation that are cheap, yet accurate enough to give good predictions of the radiative effects. We will herein introduce the multigroup-M1 model and look at its characteristics and in particular try to separate the angular error from the frequential one since these two approximation play very different roles. The angular behaviour of the model will be tested on a case proposed by Su and Olson and used by Olson et al. to compare various moments and (flux-limited) diffusion models. For the frequency behaviour, we use a simplified flame test-case and show the importance of taking good mean opacities

  8. Nuclear collective vibrations in extended mean-field theory

    Energy Technology Data Exchange (ETDEWEB)

    Lacroix, D. [Lab. de Physique Corpusculaire/ ENSICAEN, 14 - Caen (France); Ayik, S. [Tennessee Technological Univ., Cookeville, TN (United States); Chomaz, Ph. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)

    2003-07-01

    The extended mean-field theory, which includes both the incoherent dissipation mechanism due to nucleon-nucleon collisions and the coherent dissipation mechanism due to coupling to low-lying surface vibrations, is briefly reviewed. Expressions of the strength functions for the collective excitations are presented in the small amplitude limit of this approach. This fully microscopic theory is applied by employing effective Skyrme forces to various giant resonance excitations at zero and finite temperature. The theory is able to describe the gross properties of giant resonance excitations, the fragmentation of the strength distributions as well as their fine structure. At finite temperature, the success and limitations of this extended mean-field description are discussed. (authors)

  9. Evaluation of Mars CO2 Capture and Gas Separation Technologies

    Science.gov (United States)

    Muscatello, Anthony C.; Santiago-Maldonado, Edgardo; Gibson, Tracy; Devor, Robert; Captain, James

    2011-01-01

    Recent national policy statements have established that the ultimate destination of NASA's human exploration program is Mars. In Situ Resource Utilization (ISRU) is a key technology required to ,enable such missions and it is appropriate to review progress in this area and continue to advance the systems required to produce rocket propellant, oxygen, and other consumables on Mars using the carbon dioxide atmosphere and other potential resources. The Mars Atmospheric Capture and Gas separation project is selecting, developing, and demonstrating techniques to capture and purify Martian atmospheric gases for their utilization for the production of hydrocarbons, oxygen, and water in ISRU systems. Trace gases will be required to be separated from Martian atmospheric gases to provide pure CO2 to processing elements. In addition, other Martian gases, such as nitrogen and argon, occur in concentrations high enough to be useful as buffer gas and should be captured as well. To achieve these goals, highly efficient gas separation processes will be required. These gas separation techniques are also required across various areas within the ISRU project to support various consumable production processes. The development of innovative gas separation techniques will evaluate the current state-of-the-art for the gas separation required, with the objective to demonstrate and develop light-weight, low-power methods for gas separation. Gas separation requirements include, but are not limited to the selective separation of: (1) methane and water from unreacted carbon oxides (C02-CO) and hydrogen typical of a Sabatier-type process, (2) carbon oxides and water from unreacted hydrogen from a Reverse Water-Gas Shift process, (3)/carbon oxides from oxygen from a trash/waste processing reaction, and (4) helium from hydrogen or oxygen from a propellant scavenging process. Potential technologies for the separations include' freezers, selective membranes, selective solvents, polymeric sorbents

  10. Fractional Diffusion Limit for Collisional Kinetic Equations

    KAUST Repository

    Mellet, Antoine; Mischler, Sté phane; Mouhot, Clé ment

    2010-01-01

    This paper is devoted to diffusion limits of linear Boltzmann equations. When the equilibrium distribution function is a Maxwellian distribution, it is well known that for an appropriate time scale, the small mean free path limit gives rise to a

  11. Mean field approximation versus exact treatment of collisions in few-body systems

    International Nuclear Information System (INIS)

    Lemm, J.; Weiguny, A.; Giraud, B.G.

    1990-01-01

    A variational principle for calculating matrix elements of the full resolvent operator for a many-body system is studied. Its mean field approximation results in non-linear equations of Hartree (-Fock) type, with initial and final channel wave functions as driving terms. The mean field equations will in general have many solutions whereas the exact problem being linear, has a unique solution. In a schematic model with separable forces the mean field equations are analytically soluble, and for the exact problem the resulting integral equations are solved numerically. Comparing exact and mean field results over a wide range of system parameters, the mean field approach proves to be a very reliable approximation, which is not plagued by the notorious problem of defining asymptotic channels in the time-dependent mean field method. (orig.)

  12. Audio Source Separation in Reverberant Environments Using β-Divergence-Based Nonnegative Factorization

    DEFF Research Database (Denmark)

    Fakhry, Mahmoud; Svaizer, Piergiorgio; Omologo, Maurizio

    2017-01-01

    -maximization algorithm and used to separate the signals by means of multichannel Wiener filtering. We propose to estimate these parameters by applying nonnegative factorization based on prior information on source variances. In the nonnegative factorization, spectral basis matrices can be defined as the prior...... information. The matrices can be either extracted or indirectly made available through a redundant library that is trained in advance. In a separate step, applying nonnegative tensor factorization, two algorithms are proposed in order to either extract or detect the basis matrices that best represent......In Gaussian model-based multichannel audio source separation, the likelihood of observed mixtures of source signals is parametrized by source spectral variances and by associated spatial covariance matrices. These parameters are estimated by maximizing the likelihood through an expectation...

  13. Preliminary review on isotope separation of long life fission products. Application research of laser isotope separation to 135Cs

    International Nuclear Information System (INIS)

    Oshita, Hironori; Ozawa, Masaki; Ishikawa, Makoto; Koyama, Shin'ichi; Akatsuka, Hiroshi

    2007-09-01

    Recently establishment of self consistent nuclear fuel cycle has been required with respect to economical efficiency, safety and reduction of the load to the environment. Especially 135 Cs included in spent fuel of nuclear power plants has extremely long half life (3.0x10 6 y) and its water solubility leads to the anxiety of exudation into ground water for geologic disposal. The conventional methods for isotope separation based on the mass difference of isotope could not gain large separation factors, which leads to the requirement of operational repetition and large equipment. Furthermore many elements of which the masses are near to that of the object isotope are included in spent fuel, which makes it difficult to expect high separation factor by the methods merely based on the mass difference. Recent technology development of laser e.g. dye laser or semi-conductor laser has come to make it possible in principle to excite a specific isotope and separate it from other isotopes making use of its intrinsic physical and chemical properties of the excited state. This laser isotope separation (LIS) technique is believed to be suitable for cesium because of its stable properties on light absorption and emission and many studies have come to be made. This document reviews the principle, application to the separation of 135 Cs and current status of LIS and reports the subjects to be solved and suggestions; especially laser induced chemical reactions expected as a low-cost and simple equipment isotope separation method. The resulting extracted subjects are 1) the specification of the excited states of cesium i.e. extra-nuclear electron configuration, life (or duration) and transition probability, 2) the factors that may effect on the isotope shift of cesium; the mean square radius of the nucleus, electric quadrupole moment and extra nuclear electron wave function at the nucleus, 3) the factors that may cause the disturbance of the selectivity; resonant energy transference

  14. POC-SCALE TESTING OF A DRY TRIBOELECTROSTATIC SEPARATOR FOR FINE COAL CLEANING

    Energy Technology Data Exchange (ETDEWEB)

    R.H. Yoon; G.H. Luttrell; E.S. Yan; A.D. Walters

    2001-04-30

    Numerous advanced coal cleaning processes have been developed in recent years that are capable of substantially reducing both ash- and sulfur-forming minerals from coal. However, most of the processes involve fine grinding and use water as the cleaning medium; therefore, the clean coal products must be dewatered before they can be transported and burned. Unfortunately, dewatering fine coal is costly, which makes it difficult to deploy advanced coal cleaning processes for commercial applications. As a means of avoiding problems associated with the fine coal dewatering, the National Energy Technology Laboratory (NETL) developed a dry coal cleaning process in which mineral matter is separated from coal without using water. In this process, pulverized coal is subjected to triboelectrification before being placed in an electric field for electrostatic separation. The triboelectrification is accomplished by passing a pulverized coal through an in-line mixer made of copper. Copper has a work function that lies between that of carbonaceous material (coal) and mineral matter. Thus, coal particles impinging on the copper wall lose electrons to the metal thereby acquiring positive charges, while mineral matter impinging on the wall gain electrons to acquire negative charges. The charged particles then pass through an electric field where they are separated according to their charges into two or more products depending on the configuration of the separator. The results obtained at NETL showed that it is capable of removing more than 90% of the pyritic sulfur and 70% of the ash-forming minerals from a number of eastern U.S. coals. However, the BTU recoveries were less than desirable. The laboratory-scale batch triboelectrostatic separator (TES) used by NETL relied on adhering charged particles on parallel electrode surfaces and scraping them off. Therefore, its throughput will be proportional to the electrode surface area. If this laboratory device is scaled-up as is, it would

  15. Clustering performance comparison using K-means and expectation maximization algorithms.

    Science.gov (United States)

    Jung, Yong Gyu; Kang, Min Soo; Heo, Jun

    2014-11-14

    Clustering is an important means of data mining based on separating data categories by similar features. Unlike the classification algorithm, clustering belongs to the unsupervised type of algorithms. Two representatives of the clustering algorithms are the K -means and the expectation maximization (EM) algorithm. Linear regression analysis was extended to the category-type dependent variable, while logistic regression was achieved using a linear combination of independent variables. To predict the possibility of occurrence of an event, a statistical approach is used. However, the classification of all data by means of logistic regression analysis cannot guarantee the accuracy of the results. In this paper, the logistic regression analysis is applied to EM clusters and the K -means clustering method for quality assessment of red wine, and a method is proposed for ensuring the accuracy of the classification results.

  16. Meaning and Practice of Palliative Care for Hospitalized Older Adults with Life Limiting Illnesses

    Directory of Open Access Journals (Sweden)

    Bethel Ann Powers

    2011-01-01

    Full Text Available Objective. To illustrate distinctions and intersections of palliative care (PC and end-of-life (EOL services through examples from case-centered data of older adults cared for during a four-year ethnographic study of an acute care hospital palliative care consultation service. Methods. Qualitative narrative and thematic analysis. Results. Description of four practice paradigms (EOL transitions, prognostic uncertainty, discharge planning, and patient/family values and preferences and identification of the underlying structure and communication patterns of PC consultation services common to them. Conclusions. Consistent with reports by other researchers, study data support the need to move beyond equating PC with hospice or EOL care and the notion that EOL is a well-demarcated period of time before death. If professional health care providers assume that PC services are limited to assisting with and helping patients and families prepare for dying, they miss opportunities to provide care considered important to older individuals confronting life-limiting illnesses.

  17. Limited-sampling strategies for anti-infective agents: systematic review.

    Science.gov (United States)

    Sprague, Denise A; Ensom, Mary H H

    2009-09-01

    Area under the concentration-time curve (AUC) is a pharmacokinetic parameter that represents overall exposure to a drug. For selected anti-infective agents, pharmacokinetic-pharmacodynamic parameters, such as AUC/MIC (where MIC is the minimal inhibitory concentration), have been correlated with outcome in a few studies. A limited-sampling strategy may be used to estimate pharmacokinetic parameters such as AUC, without the frequent, costly, and inconvenient blood sampling that would be required to directly calculate the AUC. To discuss, by means of a systematic review, the strengths, limitations, and clinical implications of published studies involving a limited-sampling strategy for anti-infective agents and to propose improvements in methodology for future studies. The PubMed and EMBASE databases were searched using the terms "anti-infective agents", "limited sampling", "optimal sampling", "sparse sampling", "AUC monitoring", "abbreviated AUC", "abbreviated sampling", and "Bayesian". The reference lists of retrieved articles were searched manually. Included studies were classified according to modified criteria from the US Preventive Services Task Force. Twenty studies met the inclusion criteria. Six of the studies (involving didanosine, zidovudine, nevirapine, ciprofloxacin, efavirenz, and nelfinavir) were classified as providing level I evidence, 4 studies (involving vancomycin, didanosine, lamivudine, and lopinavir-ritonavir) provided level II-1 evidence, 2 studies (involving saquinavir and ceftazidime) provided level II-2 evidence, and 8 studies (involving ciprofloxacin, nelfinavir, vancomycin, ceftazidime, ganciclovir, pyrazinamide, meropenem, and alpha interferon) provided level III evidence. All of the studies providing level I evidence used prospectively collected data and proper validation procedures with separate, randomly selected index and validation groups. However, most of the included studies did not provide an adequate description of the methods or

  18. The open XXX spin chain in the SoV framework: scalar product of separate states

    Science.gov (United States)

    Kitanine, N.; Maillet, J. M.; Niccoli, G.; Terras, V.

    2017-06-01

    We consider the XXX open spin-1/2 chain with the most general non-diagonal boundary terms, that we solve by means of the quantum separation of variables (SoV) approach. We compute the scalar products of separate states, a class of states which notably contains all the eigenstates of the model. As usual for models solved by SoV, these scalar products can be expressed as some determinants with a non-trivial dependance in terms of the inhomogeneity parameters that have to be introduced for the method to be applicable. We show that these determinants can be transformed into alternative ones in which the homogeneous limit can easily be taken. These new representations can be considered as generalizations of the well-known determinant representation for the scalar products of the Bethe states of the periodic chain. In the particular case where a constraint is applied on the boundary parameters, such that the transfer matrix spectrum and eigenstates can be characterized in terms of polynomial solutions of a usual T-Q equation, the scalar product that we compute here corresponds to the scalar product between two off-shell Bethe-type states. If in addition one of the states is an eigenstate, the determinant representation can be simplified, hence leading in this boundary case to direct analogues of algebraic Bethe ansatz determinant representations of the scalar products for the periodic chain.

  19. The open XXX spin chain in the SoV framework: scalar product of separate states

    International Nuclear Information System (INIS)

    Kitanine, N; Maillet, J M; Niccoli, G; Terras, V

    2017-01-01

    We consider the XXX open spin-1/2 chain with the most general non-diagonal boundary terms, that we solve by means of the quantum separation of variables (SoV) approach. We compute the scalar products of separate states, a class of states which notably contains all the eigenstates of the model. As usual for models solved by SoV, these scalar products can be expressed as some determinants with a non-trivial dependance in terms of the inhomogeneity parameters that have to be introduced for the method to be applicable. We show that these determinants can be transformed into alternative ones in which the homogeneous limit can easily be taken. These new representations can be considered as generalizations of the well-known determinant representation for the scalar products of the Bethe states of the periodic chain. In the particular case where a constraint is applied on the boundary parameters, such that the transfer matrix spectrum and eigenstates can be characterized in terms of polynomial solutions of a usual T - Q equation, the scalar product that we compute here corresponds to the scalar product between two off-shell Bethe-type states. If in addition one of the states is an eigenstate, the determinant representation can be simplified, hence leading in this boundary case to direct analogues of algebraic Bethe ansatz determinant representations of the scalar products for the periodic chain. (paper)

  20. Acetaminophen Versus Liquefied Ibuprofen for Control of Pain During Separation in Orthodontic Patients: A Randomized Triple Blinded Clinical Trial

    Directory of Open Access Journals (Sweden)

    Tahereh Hosseinzadeh Nik

    2016-07-01

    Full Text Available The aim of this randomized clinical study was to investigate the effectiveness of acetaminophen 650 mg or liquefied ibuprofen 400 mg in pain control of orthodontic patients during separation with an elastic separator. A total of 101 patients with specific inclusion criteria were divided randomly into three groups (acetaminophen, liquefied ibuprofen, and placebo. They were instructed to take their drugs one hour before separator placement and every six hours afterward (five doses in total. They recorded their discomfort on visual analog scales immediately after separator placement, 2 hours later, 6 hours later, at bedtime, and 24 hours after separator placement. Repeated measure analysis of variance (ANOVA was used to compare the mean pain scores between the three groups. Data were collected from 89 patients. The pain increased with time in all groups. Pain scores were statistically lower in the analgesic groups compared with the placebo group (P.value<0.001, but no statistically significant difference was found in mean pain scores between the two drug groups (acetaminophen and liquefied ibuprofen (P.value=1. Acetaminophen and liquefied ibuprofen have similar potential in pain reduction during separation.