WorldWideScience

Sample records for counter current

  1. Counter current decantation washing of HLW sludge

    International Nuclear Information System (INIS)

    Brooke, J.N.; Peterson, R.A.

    1997-01-01

    The Savannah River Site (SRS) has 51 High Level Waste (HLW) tanks with typical dimensions 25.9 meters (85 feet) diameter and 10 meters (33 feet) high. Nearly 114 million liters (30 M gallons) of HLW waste is stored in these tanks in the form of insoluble solids called sludge, crystallized salt called salt cake, and salt solutions. This waste is being converted to waste forms stable for long term storage. In one of the processes, soluble salts are washed from HLW sludge in preparation for vitrification. At present, sludge is batch washed in a waste tank with one or no reuse of the wash water. Sodium hydroxide and sodium nitrite are added to the wash water for tank corrosion protection; the large volumes of spent wash water are recycled to the evaporator system; additional salt cake is produced; and sodium carbonate is formed in the washed sludge during storage by reaction with CO 2 from the air. High costs and operational concerns with the current washing process prompts DOE and WSRC to seek an improved washing method. A new method should take full advantage of the physical/chemical properties of sludge, experience from other technical disciplines, processing rate requirements, inherent process safety, and use of proven processes and equipment. Counter current solids washing is a common process in the minerals processing and chemical industries. Washing circuits can be designed using thickeners, filters or centrifuges. Realizing the special needs of nuclear work and the low processing rates required, a Counter Current Decantation (CCD) circuit is proposed using small thickeners and fluidic pumps

  2. Mass transfer in counter current flows

    Energy Technology Data Exchange (ETDEWEB)

    Doichinova, Maria D.; Popova, Petya G.; Boyadjiev, Christo B. [Bulgarian Academy of Science, Institute of Chemical Engineering, Sofia (Bulgaria)

    2011-07-01

    A theoretical analysis of gas-liquid counter-current flow in laminar boundary layers with flat phase boundary based on similarity variables method has been done. The obtained numerical results for the energy dissipation, mass transfer rate and their ratio are compared with analogous results for concurrent flows. A diffusion type of model is proposed for modeling of the mass transfer with chemical reaction in the column apparatuses in the cases of circulation zones. The presence of rising and descending flows (the change of the velocity direction) leads to using three coordinate systems. An iterative algorithm for the concentration distribution calculation is proposed. The influence of the zones breadths on the mass transfer efficiency in the column is investigated. Key words: efficiency, mass transfer, velocity distribution, column apparatuses, circulation zones.

  3. Flooding in counter-current two-phase flow

    International Nuclear Information System (INIS)

    Ragland, W.A.; Ganic, E.N.

    1982-01-01

    Flooding is a phenomenon which is best described as the transition from counter-current to co-current flow. Early notice was taken of this phenomenon in the chemical engineering industry. Flooding also plays an important role in the field of two-phase heat transfer since it is a limit for many systems involving counter-current flow. Practical applications of flooding limited processes include wickless thermosyphons and the emergency core cooling system (ECCS) of pressurized water nuclear reactors. The phenomenon of flooding also is involved in the behavior of nuclear reactor core materials during severe accident conditions where flooding is one of the mechanisms governing the motion of the molten fuel pin cladding

  4. Flooding in counter-current two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Ragland, W.A.; Ganic, E.N.

    1982-01-01

    Flooding is a phenomenon which is best described as the transition from counter-current to co-current flow. Early notice was taken of this phenomenon in the chemical engineering industry. Flooding also plays an important role in the field of two-phase heat transfer since it is a limit for many systems involving counter-current flow. Practical applications of flooding limited processes include wickless thermosyphons and the emergency core cooling system (ECCS) of pressurized water nuclear reactors. The phenomenon of flooding also is involved in the behavior of nuclear reactor core materials during severe accident conditions where flooding is one of the mechanisms governing the motion of the molten fuel pin cladding.

  5. Counter-current flow limited CHF in thin rectangular channels

    International Nuclear Information System (INIS)

    Cheng, L.Y.

    1990-01-01

    An analytical expression for counter-current-flow-limitation (CCFL) was used to predict critical heat flux (CHF) for downward flow in thin vertical rectangular channels which are prototypes of coolant channels in test and research nuclear reactors. Top flooding is the mechanism for counter-current flow limited CHF. The CCFL correlation also was used to determine the circulation and flooding-limited CHF. Good agreements were observed between the period the model predictions and data on the CHF for downflow. The minimum CHF for downflow is lower than the flooding-limited CHF and it is predicted to occur at a liquid flow rate higher than that at the flooding limit. 17 refs., 7 figs

  6. Enantioseparations in counter-current chromatography and centrifugal partition chromatography.

    Science.gov (United States)

    Foucault, A P

    2001-01-12

    Examples of chiral separations in counter-current chromatography (CCC) and centrifugal partition chromatography (CPC) are not numerous, due to the difficulty of finding chiral selectors highly selective in the liquid phase as well as a combination of solvents that does not destroy the selectivity and retains the capacity to elute chiral isomers of interest. New ideas and new chiral selectors generally come from other separation techniques, as will be highlighted in this review.

  7. Lanthanides separation by counter - current electrophoretic using α - hydroxyisobutyric acid

    International Nuclear Information System (INIS)

    Alleluia, I.B.

    1975-01-01

    Studies about counter-current electrophoretic separation of rare earth metal ions using α-hydroxyisobutyric acid as complexing electrolyte are discussed. La, Pr, Nd, Sm and Eu were separated and fractions with purities better than 99,9% were obtained, using neutron activation analysis. A relation between the first stability constant of the α-hydroxyisobutyrate/lanthanide complexes and their migration velocities were observed. (M.J.C.) [pt

  8. Study of rare earth separation by counter current electromigration

    International Nuclear Information System (INIS)

    Correa, Sergio Machado

    1995-08-01

    The counter current electromigration (CCEM) is an electrophoretic technique where the charged species migrate on an electrical field toward an electrolytic flux. Usually this electrolyte is a complexing agent and is necessary to increase the small differences between the species mobilities. A new column was developed, all made of acrylic, in a cylindrical shape. A set of experiments was carried out with the species Na + /K + , K + /Sm +3 , K + /Eu +3 and K + /Sm +3 /Eu +3 using the α-hydrox i-isobutyric acid o,01 M as the counter current electrolytic flux. From a synthetic mixture of 90% of samarium and 10% of europium was obtained the samarium ion in a purity better than 99,9% where the concentration of Eu was determined by the polarography technique. The potassium ion was used as a leading electrolyte. It was also measured the mobilities of the involved species in the α-HIBA medium. Two models are proposed, a stationary model and a dynamic one. A simulator of a simplified stationary model, prepared in FORTRAN language, was developed and tested toward experimental results. (author)

  9. Flow characteristics of counter-current flow in debris bed

    International Nuclear Information System (INIS)

    Abe, Yutaka; Adachi, Hiromichi

    2004-01-01

    In the course of a severe accident, a damaged core would form a debris bed consisting of once-molten and fragmented fuel elements. It is necessary to evaluate the dryout heat flux for the judgment of the coolability of the debris bed during the severe accident. The dryout phenomena in the debris bed is dominated by the counter-current flow limitation (CCFL) in the debris bed. In this study, air-water counter-current flow behavior in the debris bed is experimentally investigated with glass particles simulating the debris beds. In this experiment, falling water flow rate and axial pressure distributions were experimentally measured. As the results, it is clarified that falling water flow rate becomes larger with the debris bed height and the pressure gradient in the upper region of the debris bed is different from that in the lower region of the debris bed. These results indicate that the dominant region for CCFL in the debris bed is identified near the top of the debris bed. Analytical results with annular flow model indicates that interfacial shear stress in the upper region of the debris bed is larger than that in the lower region of the debris bed. (author)

  10. Combustion of pulverized coal in counter-current flow

    Energy Technology Data Exchange (ETDEWEB)

    Timnat, Y M; Goldman, Y [Technion-Israel Inst. of Tech., Haifa (Israel). Faculty of Aerospace Engineering

    1991-01-01

    In this report we describe the results obtained with two prototypes of pulverized coal combustors operating in counter-current flow, one at atmospheric pressure, the other at higher pressure and compare them to the predictions of a theoretical-numerical model, we have developed. The first prototype treats a vertical configuration, eight times larger than the one treated before (Hazanov et al. 1985), while in the second a horizontal arrangement with a smaller volume is studied. Attention was focused on particle trajectories, burnout, angle of injection, ash separation by rotational motion, effects of initial particle size and temperature, impingement velocity and the effect of gravity. Main development activity was directed to achieving stable and reliable coal burning in the combustors.

  11. Direct current stabilization of scintillation counters used for uranium prospecting

    International Nuclear Information System (INIS)

    Fraser, H.J.

    1976-01-01

    A simple system for stabilizing a scintillation counter is described which uses a dc light source (a green light emitting diode) to illuminate the photo-cathode of the photomultiplier used to detect γ-induced light pulses from the scintillator. Basically, the photomultiplier anode current due to the light emitting diode light is held constant by an automatic control loop acting on the eht voltage to keep the gain of the photomultiplier tube constant. However, because the temperature coefficient of the scintillator does not in general match that of the light emitting diode, further compensation is required to achieve constant γ pulse gain. This is provided by adding to the control circuit a current derived from the light emitting diode voltage which is an excellent measure of temperature; the use of this technique results in gain constancy to within +-1% in the 10-50 0 C ambient temperature range. Noise and countrate limitations are discussed and it is concluded that the system is generally applicable to uranium prospecting equipment. (Auth.)

  12. Current Over-the-Counter Medicine Label: Take a Look

    Science.gov (United States)

    ... This is to help protect consumers against possible criminal tampering. Drug products with tamper-evident packaging have ... Medicines Medicines in My Home (MIMH) Choosing the right over-the-counter medicine (OTCs) The Over-the- ...

  13. Lower-hybrid counter current drive for edge current density modification in DIII-D

    International Nuclear Information System (INIS)

    Fenstermacher, M.E.; Nevins, W.M.; Porkolab, M.; Bonoli, P.T.; Harvey, R.W.

    1994-01-01

    Each of the Advanced Tokamak operating modes in DIII-D is thought to have a distinctive current density profile. So far these modes have only been achieved transiently through experiments which ramp the plasma current and shape. Extension of these modes to steady state requires non-inductive current profile control, e.g., with lower hybrid current drive (LHCD). Calculations of LHCD have been done for DIII-D using the ACCOME and CQL3D codes, showing that counter driven current at the plasma edge can cancel some of the undesirable edge bootstrap current and potentially extend the VH-mode. Results will be presented for scenarios using 2.45 GHz LH waves launched from both the midplane and off-axis ports. The sensitivity of the results to injected power, n e and T e , and launched wave spectrum will also be shown

  14. Counter-current membrane reactor for WGS process: Membrane design

    Energy Technology Data Exchange (ETDEWEB)

    Piemonte, Vincenzo; Favetta, Barbara [Department of Chemical Engineering Materials and Environment, University of Rome ' ' La Sapienza' ' , via Eudossiana 18, 00184 Rome (Italy); De Falco, Marcello [Faculty of Engineering, University Campus Bio-Medico of Rome, via Alvaro del Portillo 21, 00128 Rome (Italy); Basile, Angelo [CNR-ITM, c/o University of Calabria, Via Pietro Bucci, Cubo 17/C, 87030 Rende (CS) (Italy)

    2010-11-15

    Water gas shift (WGS) is a thermodynamically limited reaction which has to operate at low temperatures, reducing kinetics rate and increasing the amount of catalyst required to reach valuable CO conversions. It has been widely demonstrated that the integration of hydrogen selective membranes is a promising way to enhance WGS reactors performance: a Pd-based MR operated successfully overcoming the thermodynamic constraints of a traditional reactor thanks to the removal of hydrogen from reaction environment. In the first part of a MR, the H{sub 2} partial pressure starts from a minimum value since the reaction has not started. As a consequence, if the carrier gas in the permeation zone is sent in counter-current, which is the most efficient configuration, in the first reactor section the H{sub 2} partial pressure in reaction zone is low while in the permeation zone is high, potentially implying back permeation. This means a bad utilization of the first part of the membrane area and thus, a worsening of the MR performance with lower H{sub 2} recovery and lower CO conversion with respect to the case in which the whole selective surface is properly used. To avoid this problem different MR configurations were evaluated by a 1-D pseudo-homogeneous model, validated with WGS industrial data reported in scientific literature. It was demonstrated that the permeated H{sub 2} flow rate per membrane surface, i.e. the membrane flux, strongly improves if selective membrane is placed only in the second part of the reactor: in fact, if the membrane is placed at L{sub m}/L{sub tot} = 0.5, the membrane flux is 0.2 kmol/(m{sup 2}h) about, if it is placed along all reactor tube (L{sub m}/L{sub tot} = 1), flux is 0.05 kmol/(m{sup 2}h). The effect of the L/D reactor ratio and of the reactor wall temperature on the CO conversion were also assessed. (author)

  15. Co-current and Counter-Current Operations for Steam Reforming of Heptane in a Novel CFB Membrane Reformer

    International Nuclear Information System (INIS)

    Chen, Z.; Elnashaie, S.S.E.H.

    2004-01-01

    Hydrogen production by steam reforming of higher hydrocarbon over nickel supported catalyst is investigated in an earlier suggested novel Circulating Fast Fluidized Bed Membrane Reformer (CFFBMR). Palladium hydrogen membranes are used with co-current and counter-current operation modes. It is found that hydrogen production has a non-monotonic dependence upon the reaction temperature in the range of 623-823 K. Between 623 and 723 K. the yields of hydrogen decrease and then increase between 723 and 823 K. This important phenomenon is investigated, discussed and explained. The simulation results shows that the reformer performance can be significantly improved using hydrogen membranes, especially in the counter-current operation mode. At low temperatures around 623 K, both .co-current and counter-current operation modes provide similar yields of hydrogen. While at temperature 723 K and higher, the counter-current operation provides the highest yield of hydrogen

  16. Oral insulin delivery: existing barriers and current counter-strategies.

    Science.gov (United States)

    Gedawy, Ahmed; Martinez, Jorge; Al-Salami, Hani; Dass, Crispin R

    2018-02-01

    The chronic and progressive nature of diabetes is usually associated with micro- and macrovascular complications where failure of pancreatic β-cell function and a general condition of hyperglycaemia is created. One possible factor is failure of the patient to comply with and adhere to the prescribed insulin due to the inconvenient administration route. This review summarizes the rationale for oral insulin administration, existing barriers and some counter-strategies trialled. Oral insulin mimics the physiology of endogenous insulin secreted by pancreas. Following the intestinal absorption of oral insulin, it reaches the liver at high concentration via the portal vein. Oral insulin on the other hand has the potential to protect pancreatic β-cells from autoimmune destruction. Structural modification, targeting a particular tissue/receptor, and the use of innovative pharmaceutical formulations such as nanoparticles represent strategies introduced to improve oral insulin bioavailability. They showed promising results in overcoming the hurdles facing oral insulin delivery, although delivery is far from ideal. The use of advanced pharmaceutical technologies and further research in particulate carrier system delivery predominantly nanoparticle utilization would offer useful tools in delivering insulin via the oral route which in turn would potentially improve diabetic patient compliance to insulin and the overall management of diabetes. © 2017 Royal Pharmaceutical Society.

  17. Experimental study of blockage of monochromatic waves by counter currents

    NARCIS (Netherlands)

    Suastika, I.K.

    1999-01-01

    Blockage of waves by a current can occur if waves are propagating on a spatially varying opposing current in which the velocity is increasing in the wave propagation direction. The ongoing waves become shorter and steeper while they are propagating against the current. Blocking occurs at the

  18. Hydrodynamic behaviour of a gas—solid counter-current packed column at trickle flow

    NARCIS (Netherlands)

    Roes, A.W.M.; van Swaaij, Willibrordus Petrus Maria

    1979-01-01

    Trickle flow of a more or less fluidized catalyst through a packed column is a promising new gas—solid counter-current operation. The hydrodynamic, behaviour of such a column, filled with dumped PALL rings, has been investigated, while some results have been obtained with RASCHIG rings and

  19. Counter-current acid leaching process for copper azole treated wood waste.

    Science.gov (United States)

    Janin, Amélie; Riche, Pauline; Blais, Jean-François; Mercier, Guy; Cooper, Paul; Morris, Paul

    2012-09-01

    This study explores the performance of a counter-current leaching process (CCLP) for copper extraction from copper azole treated wood waste for recycling of wood and copper. The leaching process uses three acid leaching steps with 0.1 M H2SO4 at 75degrees C and 15% slurry density followed by three rinses with water. Copper is recovered from the leachate using electrodeposition at 5 amperes (A) for 75 min. Ten counter-current remediation cycles were completed achieving > or = 94% copper extraction from the wood during the 10 cycles; 80-90% of the copper was recovered from the extract solution by electrodeposition. The counter-current leaching process reduced acid consumption by 86% and effluent discharge volume was 12 times lower compared with the same process without use of counter-current leaching. However, the reuse of leachates from one leaching step to another released dissolved organic carbon and caused its build-up in the early cycles.

  20. Hydrodynamic and mechanical tests of a newly improved counter-current multi-stage centrifugal extractor

    International Nuclear Information System (INIS)

    Ionita, Gheorghe; Mirica, Dumitru; Croitoru, Cornelia; Stefanescu, Ioan; Retegan, Teodora

    2003-01-01

    Total actinide recovery, lanthanide/actinide separation and the selective partitioning of actinide from high level waste (HLW) are nowadays of major interest. Actinide partitioning with a view to safe disposing of HLW or utilization in many other applications of recovered elements involves an extraction process usually carried out by means of a mixer-settler, pulse column or centrifugal contactor. This last, presents some doubtless advantages and responds to the above mentioned goals. A new type of counter-current multistage centrifugal extractor has been designed and built. Similar apparatus was not found in the literature published to-date. The counter-current multi-stage centrifugal extractor is a stainless steel cylinder with an effective length of 346 mm, the effective diameter of 100 mm and a volume of 1.5 liters, working in horizontal position. The new internal structure and geometry of the new advanced centrifugal extractor consisting of nine cells (units), five rotation units, two mixing units, two propelling units and two final plates, ensures the counter-current running of the two phases.The central shaft having the rotation cells fixed on it is coupled by an intermediary connection to a electric motor of high rotation speed. Conceptual layout of the advanced counter-current multi-stage centrifugal extractor is presented. The newly designed extractor has been tested at 1000-3000 rot/min for a ratio of the aqueous/organic phase =1 to examine the mechanical behavior and the hydrodynamics of the two phases in countercurrent. The results showed that the performances have been generally good and the design requirements were fulfilled. The newly designed counter-current multistage centrifugal extractor appears to be a promising way to increase extraction rate of radionuclides and metals from liquid effluents. (authors)

  1. New improved counter - current multi-stage centrifugal extractor for solvent extraction process

    International Nuclear Information System (INIS)

    Gheorghe, Ionita; Mirica, Dumitru; Croitoru, Cornelia; Stefanescu, Ioan; Retegan, Teodora; Kitamoto, Asashi

    2003-01-01

    Total actinide recovery, lanthanide/actinide separation and selective partitioning of actinide from high level waste (HLW) are nowadays of a major interest. Actinide partitioning with a view to safe disposing of HLW or utilization in many other applications of recovered elements involves an extraction process usually by means of mixer-settler, pulse column or centrifugal contactor. The latter, presents some doubtless advantages and responds to the above mentioned goals. A new type of counter-current multistage centrifugal extractor has been designed and performed. A similar apparatus was not found from in other published papers as yet. The counter-current multi-stage centrifugal extractor was a cylinder made of stainless steel with an effective length of 346 mm, the effective diameter of 100 mm and a volume of 1.5 liters, working in a horizontal position. The new internal structure and geometry of the new advanced centrifugal extractor consisting of nine cells (units), five rotation units, two mixing units, two propelling units and two final plates, ensures the counter-current running of the two phases.The central shaft having the rotation cells fixed on it is coupled by an intermediary connection to a electric motor of high rotation speed. The conceptual layout of the advanced counter-current multi-stage centrifugal extractor is presented. The newly designed extractor has been tested at 500-2800 rot/min for a ratio of the aqueous/organic phase =1 to examine the mechanical behavior and the hydrodynamics of the two phases in countercurrent. The results showed that the performances have been generally good and the design requirements were fulfilled. The newly designed counter-current multistage centrifugal extractor appears to be a promising way to increase extraction rate of radionuclides and metals from liquid effluents. (authors)

  2. Advanced counter-current multi-stage centrifugal extractor for solvent extraction process

    International Nuclear Information System (INIS)

    Ionita, Gheorghe; Mirica, Dumitru; Croitoru, Cornelia; Stefanescu, Ioan; Steflea, Dumitru; Mihaila, V.; Peteu, Gh.

    2002-01-01

    Total actinide recovery, lanthanide/actinide separation and the selective partitioning of actinide from high level waste (HLW) are nowadays of a major interest. Actinide partitioning with a view to safe disposing of HLW or utilization in many other applications of recovered elements involve an extraction process usually by means of mixer-settler, pulse column or centrifugal contactor. The latter, presents some doubtless advantages and responds to the above mentioned goals. A new type of counter-current multistage centrifugal extractor has been designed and built. The counter-current multi-stage centrifugal extractor is a stainless steel cylinder with an effective length of 346 mm, the effective diameter of 100 mm and a volume of 1.5 liters, having horizontal position as working position. The new internal structure and geometry of the new advanced centrifugal extractor is shown. It consists of nine cells (units): five rotation units, two mixing units, two propelling units and two final plates which ensures the counter-current running of the two phases. The central shaft having the rotation cells fixed on it is connected to an electric motor of high rotation speed. The extractor has been tested at 1000-3000 rot/min for a ratio of the aqueous/organic phase = 1. The mechanical and hydrodynamic behavior of the two phases in counter-current are described. The results showed that the performances have been generally good. The new facility appears to be a promising idea to increase extraction rate of radionuclides and metals from liquid effluents. (authors)

  3. Separation of calcium isotopes by counter-current electromigration in molten salts (1962)

    International Nuclear Information System (INIS)

    Menes, F.; Dirian, G.; Roth, E.

    1962-01-01

    The method of counter-current electromigration in molten salts has been applied to calcium bromide with an alkali metal bromide added to the cathode compartment. Enrichments on calcium-46 greater than a factor of two were obtained at the anode. The mass effect was found to be about 0.06. An estimation of the cost of energy for a process based on this method has been made. (authors) [fr

  4. Hybrid indirect/direct contactor for thermal management of counter-current processes

    Science.gov (United States)

    Hornbostel, Marc D.; Krishnan, Gopala N.; Sanjurjo, Angel

    2018-03-20

    The invention relates to contactors suitable for use, for example, in manufacturing and chemical refinement processes. In an aspect is a hybrid indirect/direct contactor for thermal management of counter-current processes, the contactor comprising a vertical reactor column, an array of interconnected heat transfer tubes within the reactor column, and a plurality of stream path diverters, wherein the tubes and diverters are configured to block all straight-line paths from the top to bottom ends of the reactor column.

  5. Purification of drugs from biological fluids by counter-current chromatography.

    Science.gov (United States)

    Hochlowski, Jill E; Pan, Jeffrey Y; Searle, Philip A; Buck, Wayne R; Spanton, Stephen G

    2009-08-21

    Experiments were performed to demonstrate the potential of counter-current chromatography (CCC) for the isolation of drugs and their metabolites from biological matrices relevant to the metabolism studies of pharmaceutical research. Examples of typical drugs are spiked into biological media ex vivo to provide test samples for analysis. A mass spectrometer hyphenated to a CCC allows for the detection of small molecule drugs within the matrix through selected ion monitoring, and fraction collection can provide material for further structural elucidation by NMR.

  6. The counter-current flooding limit in vertical tubes with and without orifices

    International Nuclear Information System (INIS)

    Tye, P.; Davidson, M.; Teyssedou, A.; Tapucu, A.; Matuszkiewicz, A.; Midvidy, W.

    1993-01-01

    For hypothetical loss of coolant accidents in nuclear reactors, rapid reflooding of the core is desirable. In CANDU reactors the cooling water is injected into the headers which are connected to the fuel channels by the feeder pipes. These pipes consist of vertical and horizontal runs; in some feeders, orifices and/or venturi flow meters are installed for flow adjustments and measurements respectively. For certain postulated accident scenarios, steam coming from the fuel channels and/or generated in the hot feeders may flow in the direction opposite to that of the cooling water thereby, creating a vertical or horizontal counter-current two-phase flow. Under these conditions, the rate at which cooling water can enter the fuel channels may be limited by the flooding phenomena. This phenomena is greatly affected by the geometry of the feeder pips, shape and number of fittings, and the flow area restrictions located in the feeders. In this paper the influence that orifice type flow area restrictions have on the counter-current flooding limit (CCFL) in a vertical tube is examined. air and water at close to atmospheric conditions are used as the working fluids. The data collected on the counter-current flooding limit in a vertical tube both with and without flow area restrictions is compared against some of the most commonly used correlations that are available in the open literature. Data on the two-phase counter-current pressure drop below the flooding point are also presented. 12 refs., 10 figs., 1 tab

  7. Counter-current gas-liquid two-phase flow in a narrow rectangular channel

    International Nuclear Information System (INIS)

    Sohn, Byung Hu; Kim, Byong Joo

    2000-01-01

    A study of counter-current two-phase flow in a narrow rectangular channel has been performed. Two-phase flow patterns and void fractions were experimentally studied in a 760 mm long and 100 mm wide test section with 3.0 mm gap. The resulting data have been compared to previous transition criteria and empirical correlations. The comparison of experimental data to the transition criteria developed by Taitel and Barnea showed good agreement for the bubbly-to-slug transition. For the criteria of Mishima and Ishii to be applicable to the slug to churn transition, a new model seems to be needed for the accurate prediction of the distribution parameter for the counter-current flow in narrow rectangular channels. For the churn-to-annular transition the model of Taitel and Barnea was found to be close to the experimental data. However the model should be improved in conjunction with the channel geometry to accurately predict the counter-current flow limitation and flow transition. It was verified the distribution parameter was well-correlated by the drift-flux model. The distribution parameter for the present study was found to be about 1.2 for all flow regimes except 1.0 for an annular flow. (author)

  8. Counter current 'emulsion flow' extractor for continuous liquid-liquid extraction from suspended solutions

    International Nuclear Information System (INIS)

    Yanase, Nobuyuki; Naganawa, Hirochika; Nagano, Tetsushi; Noro, Junji

    2011-01-01

    A single current 'emulsion flow' liquid-liquid extraction apparatus has a head with a number of holes from which micrometer-sized droplets of an aqueous phase spout into an organic phase to mix the two liquid phases. For practical use, however, a fatal problem can occur when particulate components in the aqueous phase plug the holes. In the present study, we have succeeded in solving the problem by applying a counter current-type emulsion flow extractor where micrometer-sized droplets of the organic phase are generated. (author)

  9. Application in low level counting of corona counters operating in voltage or current pulse recording modes

    International Nuclear Information System (INIS)

    Oravec, J.; Usacev, S.; Duka-Zojomi, A.; Sitar, B.; Benovic, D.; Holy, K.

    1977-01-01

    The advantages of current or voltage modes of recording are discussed. It appears that the current mode is more advantageous in measurements of rare events caused by highly ionizing particles on a high background of weakly ionizing particles. A 2.3 litre multiwire corona counter was used for the determination of 226 Ra content in drinking water. The 226 Ra content was estimated by measuring 222 Rn activity. The minimum measurable activity of the system was 0.07 pCi/l of water. (author)

  10. Estimation of shear stress in counter-current gas-liquid annular two-phase flow

    International Nuclear Information System (INIS)

    Abe, Yutaka; Akimoto, Hajime; Murao, Yoshio

    1991-01-01

    The accuracy of the correlations of the friction factor is important for the counter-current flow (CCF) analysis with two-fluid model. However, existing two fluid model codes use the correlations of friction factors for co-current flow or correlation developed based on the assumption of no wall shear stress. The assessment calculation for two fluid model code with those existing correlations of friction factors shows the falling water flow rate is overestimated. Analytical model is developed to calculate the shear stress distribution in water film at CCF in order to get the information on the shear stress at the interface and the wall. The analytical results with the analysis model and Bharathan's CCF data shows that the wall shear stress acting on the falling water film is almost same order as the interfacial shear stress and the correlations for co-current flow cannot be applied to the counter-current flow. Tentative correlations of the interfacial and the wall friction factors are developed based on the results of the present study. (author)

  11. Identifying Natural syNergist from Pongamia pinnata Using High-Speed Counter-Current Chromatography Combined with Isobolographic Analysis

    Directory of Open Access Journals (Sweden)

    Hao Yin

    2017-03-01

    Full Text Available For identifying the synergistic compounds from Pongamia pinnata, an approach based on high-speed counter-current chromatography (HSCCC combined with isobolographic analysis was designed to detect the synergistic effects in the complex mixture [...

  12. Steady and transient states of a two-phase counter current flow

    International Nuclear Information System (INIS)

    Siebert, S.

    1984-06-01

    The aim of this work is to estimate the efficiency of the counter current exchange between a heavy dispersed phase and a continous light phase in a pulse perforated plate column. From an experimental point, hydraulic measurements (retention ratio, droplet size) and residence time measurements (radioactive tracers). The model will be so applied to the calculation of retention ratios in steady conditions then of tracer concentrations in transient conditions. From a numerical point of view a fixed point type iteration then a method Runge Kutta are then adapted [fr

  13. Counter current extraction for the partitioning of actinides from PFBR-SHLW using TODGA

    International Nuclear Information System (INIS)

    Ansari, S.A.; Gujar, R.B.; Kumar, Mithilesh; Seshagiri, T.K.; Godbole, S.V.; Manchanda, V.K.; Rajeswari, S.; Antony, M.P.; Srinivasan, T.G.

    2009-01-01

    Counter current extraction for the partitioning of actinides from simulated HLW of PFBR origin was demonstrated with 0.1M TODGA + 0.5M DHOA dissolved in NPH using a 16 stage mixer-settler unit. Results demonstrated that all lanthanides could be quantitatively extracted from the feed solution and quantitatively stripped from the loaded organic phase with 0.2M HNO 3 . The extracted lanthanides are not scrubbed with 0.2M oxalic acid at 5M HNO 3 in the scrubbing cycle. Elements such as Ba, Cd and Sn were not extracted. However, Pd was partially extracted but was scrubbed quantitatively. (author)

  14. Preparative Separation of Phenolic Compounds from Halimodendron halodendron by High-Speed Counter-Current Chromatography

    OpenAIRE

    Wang, Jihua; Gao, Haifeng; Zhao, Jianglin; Wang, Qi; Zhou, Ligang; Han, Jianguo; Yu, Zhu; Yang, Fuyu

    2010-01-01

    Three phenolic compounds, p-hydroxybenzoic acid (1), isorhamnetin-3-O-β-D-rutinoside (2), and 3,3'-di-O-methylquercetin (5), along with a phenolic mixture were successfully separated from the ethyl acetate crude extract of Halimodendron halodendron by high-speed counter-current chromatography (HSCCC) with chloroform-methanol-water-acetic acid (4:3:2:0.05, v/v) as the two-phase solvent system. The phenolic mixture from HSCCC was further separated by preparative HPLC and purified by Sephadex LH...

  15. Simultaneous separation of three isomeric sennosides from senna leaf (Cassia acutifolia) using counter-current chromatography.

    Science.gov (United States)

    Park, Sait Byul; Kim, Yeong Shik

    2015-10-01

    Senna leaf is widely consumed as tea to treat constipation or to aid in weight loss. Sennoside A, A1 , and B are dirheinanthrone glucosides that are abundant and the bioactive constituents in the plant. They are isomers that refer to the (R*R*), (S*S*), and (R*S*) forms of protons on C-10 and C-10' centers and it is difficult to refine them individually due to their structural similarities. The new separation method using counter-current chromatography successfully purified sennoside A, A1 , and B from senna leaf (Cassia acutifolia) while reversed-phase medium-pressure liquid chromatography yielded sennoside A only. n-Butanol/isopropanol/water (5:1:6, v/v/v) was selected as the solvent system for counter-current chromatography operation, and the partition coefficients were carefully determined by adding different concentrations of formic acid. High-resolution mass spectrometry and NMR spectroscopy were performed to verify the chemical properties of the compounds. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Experimental study of falling water limitation under counter-current flow in the vertical rectangular channel

    International Nuclear Information System (INIS)

    Usui, Tohru; Kaminaga, Masanori; Sudo, Yukio.

    1988-07-01

    Quantitative understanding of critical heat flux (CHF) in the narrow vertical rectangular channel is required for the thermo-hydroulic design and the safety analysis of research reactors in which flat-plate-type fuel is adopted. Especially, critical heat flux under low downward velocity has a close relation with falling water limitation under counter-current flow. Accordingly, CCFL (Counter-current Flow Limitation) experiments were carried out for both vertical rectangular channels and vertical circular tubes varried in their size and configuration of their cross sections, to make clear CCFL characteristics in the vertical rectangular channels. In the experiments, l/de of the rectangular channel was changed from 3.5 to 180. As the results, it was clear that different equivalent hydraulic diameter de, namely width or water gap of channel, gave different CCFL characteristics of rectangular channel. But the influence of channel length l on CCFL characteristics was not observed. Besides, a dimensionless correlation to estimate a relation between upward air velocity and downward water velocity was proposed based on the present experimental results. The difference of CCFL characteristics between rectangular channels and circular tubes was also investigated. Especially for the rectangular channels, dry-patches appearing condition was made clear as a flow-map. (author)

  17. Resolution of gram quantities of racemates by high-speed counter-current chromatography.

    Science.gov (United States)

    Ma, Y; Ito, Y; Foucault, A

    1995-06-02

    Gram quantities of (+/-)-dinitrobenzoyl amino acids were separated by high-speed counter-current chromatography (CCC) using N-dodecanoyl-L-proline-3,5-dimethylanilide as a chiral selector (CS). Standard and pH-zone-refining CCC techniques were compared. By using the standard technique, 10 mg to a maximum of 1 g of samples was resolved in 2-9 h simply by increasing the concentration of the CS in the stationary phase. By using pH-zone-refining CCC, even more sample (2 g) was efficiently separated in less time (3 h). In both techniques, leakage of CS from the column was negligible. The method requires no solid support and the same column can be used repeatedly to separate a variety of enantiomers by dissolving appropriate chiral selectors in the stationary phase.

  18. Separation of two major chalcones from Angelica keiskei by high-speed counter-current chromatography.

    Science.gov (United States)

    Kil, Yun-Seo; Nam, Joo-Won; Lee, Jun; Seo, Eun Kyoung

    2015-08-01

    Angelica keiskei (Shin-sun cho) is an edible higher plant with the beneficial preventive effects on cancer, hypertension, and coronary heart disease. Two bioactive chalcones of Shin-sun cho, xanthoangelol (1) and 4-hydroxyderricin (2), were separated simultaneously by using high-speed counter-current chromatography with a two-phase solvent system composed of n-hexane-EtOAc-MeOH-H2O (9:5:9:4). Only nonconsuming processes, solvent fractionations and Sephadex LH-20 column chromatography, were conducted as presteps. Xanthoangelol (1, 35.9 mg, 99.9 % purity at 254 and 365 nm) and 4-hydroxyderricin (2, 4.4 mg, 98.7 % purity at 254 nm and 98.8 % purity at 365 nm) were successfully purified from 70 mg of the processed extract from A. keiskei. The structures of two compounds were confirmed by (1)H- and (13)C-NMR analysis.

  19. Counter-current extraction studies for the recovery of neptunium by the Purex process. Part I

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, N.; Nadkarni, M. N.; Kumar, S. V.; Kartha, P. K.S.; Sonavane, R. R.; Ramaniah, M. V.; Patil, S. K.

    1974-07-01

    It is proposed to recover neptunium-237, along with uranium and plutonium, during the fuel reprocessing in the PREFRE plant at Tarapur. Counter-current extraction studies, relevant to the code contamination (HA) and partitioning (IA) cycles of the purex process, were carried out to arrive at suitable chemical flowsheet conditions which would enable the co-extraction of neptunium along with uranium and plutonium. The results of the studies carried out using a laboratory mixer-settler unit and synthetic mixtures of neptunium and uranium are reported here. Based on these results, the chemical flowsheet conditions are proposed for the co-extraction of neptunium even if it exists as Np(V) in the aqueous feed solution. (auth)

  20. Isolation of deoxypodophyllotoxin and podophyllotoxin from Juniperus sabina by high speed counter current chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Y.; Yang, Y.; Chen, Q.; Kasimu, R.; Aisa, H.A.

    2016-11-01

    Deoxypodophyllotoxin and podophyllotoxin are known for their excellent anti-proliferative and anti-tumor activities, therefore large amount of pure compounds is urgently needed as authentic standards for various in vivo and in vitro studies. In this paper, an effective, rapid separation and purification method of deoxypodophyllotoxin and podophyllotoxin from the crude extract of Juniperus sabina was established using high speed counter current chromatography (HSCCC). HSCCC was performed with atwo phase solvent system comprising of n-hexane-ethylacetate-methanol-water (3:5:3:5, v/v) at the flow rate of 2mL/min at the speed of 850 rpm. 34.8 mg of deoxypodophyllotoxin and 7.9 mg of podophyllotoxin were obtained from 200 mg crude sample with a purity of 96.5% and 94.4%, respectively, as determined by high performance liquid chromatography (HPLC). (Author)

  1. Counter-current flow in a vertical to horizontal tube with obstructions

    Energy Technology Data Exchange (ETDEWEB)

    Tye, P.; Matuszkiewicz, A.; Teyssedou, A. [Institut de Genie Nucleaire, Quebec (Canada)] [and others

    1995-09-01

    This paper presents experimental results on counter-current flow and flooding in an elbow between a vertical and a horizontal run. The experimental technique used allowed not only the flooding limit to be determined, but also the entire partial delivery region to be studied as well. The influence that various size orifices placed in the horizontal run have on both the delivered liquid flow rates and on the flooding limits is also examined. It is observed that both the flooding limits and the delivered liquid flow rates decrease with decreasing orifice size. Further, it is also observed that the mechanisms that govern the partial delivery of the liquid are significantly different when an orifice is present in the horizontal leg as compared to the case when no orifice is present.

  2. Multiple dual mode counter-current chromatography with variable duration of alternating phase elution steps.

    Science.gov (United States)

    Kostanyan, Artak E; Erastov, Andrey A; Shishilov, Oleg N

    2014-06-20

    The multiple dual mode (MDM) counter-current chromatography separation processes consist of a succession of two isocratic counter-current steps and are characterized by the shuttle (forward and back) transport of the sample in chromatographic columns. In this paper, the improved MDM method based on variable duration of alternating phase elution steps has been developed and validated. The MDM separation processes with variable duration of phase elution steps are analyzed. Basing on the cell model, analytical solutions are developed for impulse and non-impulse sample loading at the beginning of the column. Using the analytical solutions, a calculation program is presented to facilitate the simulation of MDM with variable duration of phase elution steps, which can be used to select optimal process conditions for the separation of a given feed mixture. Two options of the MDM separation are analyzed: 1 - with one-step solute elution: the separation is conducted so, that the sample is transferred forward and back with upper and lower phases inside the column until the desired separation of the components is reached, and then each individual component elutes entirely within one step; 2 - with multi-step solute elution, when the fractions of individual components are collected in over several steps. It is demonstrated that proper selection of the duration of individual cycles (phase flow times) can greatly increase the separation efficiency of CCC columns. Experiments were carried out using model mixtures of compounds from the GUESSmix with solvent systems hexane/ethyl acetate/methanol/water. The experimental results are compared to the predictions of the theory. A good agreement between theory and experiment has been demonstrated. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Numerical Simulations of Counter Current Flow Experiments Using a Morphology Detection Algorithm

    Directory of Open Access Journals (Sweden)

    Thomas Höhne

    2012-09-01

    Full Text Available In order to improve the understanding of counter-current two-phase flows and to validate new physical models, CFD simulations of 1/3rd scale model of the hot leg of a German Konvoi PWR with rectangular cross section was performed. Selected counter-current flow limitation (CCFL experiments at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR were calculated with ANSYS CFX 12.1 using the multi-fluid Euler-Euler modeling approach. The transient calculations were carried out using a gas/liquid inhomogeneous multiphase flow model coupled with a SST turbulence model for each phase. In the simulation, the surface drag was approached by a new correlation inside the Algebraic Interfacial Area Density (AIAD model. The AIAD model allows the detection of the morphological form of the two phase flow and the corresponding switching via a blending function of each correlation from one object pair to another. As a result this model can distinguish between bubbles, droplets and the free surface using the local liquid phase volume fraction value. A comparison with the high-speed video observations shows a good qualitative agreement. The results indicated that quantitative agreement of the CCFL characteristics between calculation and experimental data was obtained. To validate the model and to study scaling effects CFD simulations of the CCFL phenomenon in a full scale PWR hot leg of the UPTF test facility were performed. Also these results indicated a good agreement between the calculation and experimental data. The final goal is to provide an easy usable AIAD framework for all ANSYS CFX users, with the possibility of the implementation of their own correlations.

  4. Preparative Separation of Six Rhynchophylla Alkaloids from Uncaria macrophylla Wall by pH-Zone Refining Counter-Current Chromatography

    OpenAIRE

    Zhang, Qinghai; Lin, Changhu; Duan, Wenjuan; Wang, Xiao; Luo, Aiqin

    2013-01-01

    pH-Zone refining counter-current chromatography was successfully applied to the preparative isolation and purification of six alkaloids from the ethanol extracts of Uncaria macrophylla Wall. Because of the low content of alkaloids (about 0.2%, w/w) in U. macrophylla Wall, the target compounds were enriched by pH-zone refining counter-current chromatography using a two-phase solvent system composed of petroleum ether–ethyl acetate–isopropanol–water (2:6:3:9, v/v), adding 10 mM triethylamine ...

  5. Transition from condensation-induced counter-current flow to dispersed flow

    International Nuclear Information System (INIS)

    Gale, J.; Tiselj, I.

    2004-01-01

    Model of transition from the horizontally stratified condensation-induced counter-current flow to slug flow has been analyzed with computer code WAHA and compared to the experimental data obtained in the steamline of the PMK2 test facility of Hungarian Atomic Energy Institute. The experiment was performed in the steamline initially filled with hot vapor that was gradually flooded with cold liquid. Successful simulation of the condensation-induced water hammer that follows the transition, requires accurate description of the horizontally stratified and slug flow regimes and criteria for transition between both flow regimes. Current version of the WAHA code, not verified for the condensation induced type of the water hammer, predicts the water-hammer pressure peak that exceeds 600 bar, while the measured pressure is p m = 170 ± 50 bar. Sensitivity analysis of the inter-phase exchange terms and transition conditions, pointed to the most important closure relations for heat, mass and momentum transfer. The main conclusion of the analysis is large uncertainty of the simulations: minor modification of the crucial correlations can lead to a severe water-hammer in one case, or to the 'calm' transient without pressure peaks in the other case. Large uncertainty is observed in experiments. The same simulation was performed also with RELAP5 code. However, no water hammer was predicted. (author)

  6. Numerical modeling of counter-current condensation in a Black Liquor Gasification plant

    International Nuclear Information System (INIS)

    Risberg, Mikael; Gebart, Rikard

    2013-01-01

    Pressurized Entrained flow High Temperature Black Liquor Gasification is a novel technique to recover the inorganic chemicals and available energy in black liquor originating from kraft pulping. The gasifier has a direct quench that quickly cools the raw syngas when it leaves the hot reactor by spraying the gas with a water solution. As a result, the raw syngas becomes saturated with steam. Typically the gasifier operates at 30 bar which corresponds to a dew point of about 235 °C and a steam concentration in the saturated syngas that is about 3 times higher than the total concentration of the other species in the syngas. After the quench cooler the syngas is passed through a counter-current condenser where the raw syngas is cooled and most of the steam is condensed. The condenser consists of several vertical tubes where reflux condensation occurs inside the tubes due to water cooling of the tubes on the shell-side. A large part of the condensation takes place inside the tubes on the wall and results in a counterflow of water driven by gravity through the counter current condenser. In this study a computational fluid dynamics model is developed for the two-phase fluid flow on the tube-side of the condenser and for the single phase flow of the shell-side. The two-phase flow was treated using an Euler–Euler formulation with closure correlations for heat flux, condensation rate and pressure drop inside the tubes. The single-phase model for the shell side uses closure correlations for the heat flux and pressure drop. Predictions of the model are compared with results from experimental measurements in a condenser used in a 3 MW Black Liquor Gasification development plant. The results are in good agreement with the limited experimental data that has been collected in the experimental gasifier. However, more validation data is necessary before a definite conclusion can be drawn about the predictive capability of the code. -- Highlights: • A multi-phase model for a

  7. Elution-extrusion counter-current chromatography for the separation of two pairs of isomeric monoterpenes from Paeoniae Alba Radix.

    Science.gov (United States)

    Chu, Chu; Zhang, Shidi; Tong, Shengqiang; Li, Xingnuo; Li, Qingyong; Yan, Jizhong

    2015-09-01

    In this work, a simple and efficient protocol for the rapid separation of two pairs of isomeric monoterpenes from Paeoniae Alba Radix was developed by combining macroporous resin and elution-extrusion counter-current chromatography. The crude extract was firstly subjected to a D101 macroporous resin column eluted with water and a series of different concentrations of ethanol. Then, effluents of 30 and 95% ethanol were collected as sample 1 and sample 2 for further counter-current chromatography purification. Finally, a pair of isomers, 96 mg of compound 1 and 48 mg of compound 2 with purities of 91.1 and 96.2%, respectively, was isolated from 200 mg of sample 1. The other pair of isomers, 14 mg of compound 3 and 8 mg of compound 4 with purities of 93.6 and 88.9%, respectively, was isolated from 48 mg of sample 2. Their purities were analyzed by high-performance liquid chromatography, and their chemical structures were identified by mass spectrometry and (1) H NMR spectroscopy. Compared to a normal counter-current chromatography separation, the separation time and solvent consumption of elution-extrusion counter-current chromatography were reduced while the resolutions were still good. The established protocol is promising for the separation of natural products with great disparity of content in herbal medicines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Analysis of the Conditions for the Appearance of the 'Overshootö Phenomenon in Counter-Current Packed Columns

    Czech Academy of Sciences Publication Activity Database

    Akramov, T. A.; Svoboda, Petr; Jiřičný, Vladimír; Staněk, Vladimír

    2004-01-01

    Roč. 43, č. 18 (2004), s. 5899-5903 ISSN 0888-5885 R&D Projects: GA ČR GA104/03/1558 Institutional research plan: CEZ:AV0Z4072921 Keywords : counter-current flow * holdup overshoot * mathematical analysis Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.424, year: 2004

  9. Behaviour of liquid films and flooding in counter-current two-phase flow, (1)

    International Nuclear Information System (INIS)

    Suzuki, Shin-ichi; Ueda, Tatsuhiro.

    1978-01-01

    This paper reports on the results of study of the behavior of liquid film and flooding in counter-current two phase flow, and the flow speed of gas phase was measured over the wide ranges of tube diameter, tube length, amount of liquid flow, viscosity and surface tension. Liquid samples used for this experiment were water, glycerol, and second octyl alcohol. The phenomena were observed with a high speed camera. The maximum thickness of liquid film was measured, and the effects of various factors on the flooding were investigated. The results of investigation were as follows. The big waves which cause the flooding were developed by the interaction of one of the waves on liquid film surface with gas phase flow. The flow speed of gas phase at the time of beginning of flooding increases with the reduction of amount of liquid flow and the increase of tube diameter. The flooding flow speed is reduced with the increase of tube length. The larger maximum film thickness at the time of no gas phase flow causes flooding at low gas phase flow speed. (Kato, T.)

  10. Purification of optical imaging ligand-Cybesin by high-speed counter-current chromatography

    Science.gov (United States)

    Ma, Zhiyong; Ma, Ying; Sun, Xilin; Ye, Yunpeng; Shen, Baozhong; Chen, Xiaoyuan; Ito, Yoichiro

    2010-01-01

    Fluorescent Cybesin (Cypate-Bombesin Peptide Analogue Conjugate) was synthesized from Indocyanine Green (ICG) and the bombesin receptor ligand as a contrast agent for detecting pancreas tumors. However, the LC–MS analysis indicated that the target compound was only a minor component in the reaction mixture. Since preparative HPLC can hardly separate such a small amount of the target compound directly from the original crude reaction mixture without a considerable adsorptive loss onto the solid support, high-speed counter-current chromatography (HSCCC) was used for purification since the method uses no solid support and promises high sample recovery. A suitable two-phase solvent system composed of hexane/ethyl acetate/methanol/methyl t.-butyl ether/acetonitrile/water) at a volume ratio of 1:1:1:4:4:7 was selected based on the partition coefficient of Cybesin (K ≈ 0.9) determined by LC–MS. The separation was performed in two steps using the same solvent system with lower aqueous mobile phase. From 400 mg of the crude reaction mixture the first separation yielded 7.7 mg of fractions containing the target compound at 12.8% purity, and in the second run 1 mg of Cybesin was obtained at purity of 94.0% with a sample recovery rate of over 95% based on the LC–MS Analysis. PMID:20933483

  11. Preparative separation of cacao bean procyanidins by high-speed counter-current chromatography.

    Science.gov (United States)

    Li, Lingxi; Zhang, Shuting; Cui, Yan; Li, Yuanyuan; Luo, Lanxin; Zhou, Peiyu; Sun, Baoshan

    2016-11-15

    In this work, an efficient method for preparative separation of procyanidins from raw cacao bean extract by high-speed counter-current chromatography (HSCCC) was developed. Under the optimized solvent system of n-hexane-ethyl acetate-water (1:50:50, v/v/v) with a combination of head-tail and tail-head elution modes, various procyanidins fractions with different polymerization degrees were successfully separated. UPLC, QTOF-MS and 1 H NMR analysis verified that these fractions contained monomer up to pentamer respectively. Dimeric procyanidin B2 (purity>86%) could be isolated by HSCCC in a single run. Other individual procyanidins in these fractions could be further isolated and purified by preparative HPLC. The developed HSCCC together with preparative HPLC techniques appeared to be a useful tool for large preparation of different procyanidins from cacao beans. Furthermore, by antioxidant activity assays, it was proved that both fractions and individual procyanidins possessed greater antioxidant activities compared to standard trolox. The antioxidant activities of procyanidins increase as the increase of their polymerization degree. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Compact type-I coil planet centrifuge for counter-current chromatography.

    Science.gov (United States)

    Yang, Yi; Gu, Dongyu; Liu, Yongqiang; Aisa, Haji Akber; Ito, Yoichiro

    2010-02-19

    A compact type-I coil planet centrifuge has been developed for performing counter-current chromatography. It has a revolution radius of 10 cm and a column holder height of 5 cm compared with 37 and 50 cm in the original prototype, respectively. The reduction in the revolution radius and column length permits application of higher revolution speed and more stable balancing of the rotor which leads us to learn more about its performance and the future potential of type-I coil planet centrifuge. The chromatographic performance of this apparatus was evaluated in terms of retention of the stationary phase (S(f)), peak resolution (R(s)), theoretical plate (N) and peak retention time (t(R)). The results of the experiment indicated that increasing the revolution speed slightly improved both the retention of the stationary phase and the peak resolution while the separation time is remarkably shortened to yield an excellent peak resolution at a revolution speed of 800 rpm. With a 12 ml capacity coiled column, DNP-DL-glu, DNP-beta-ala and DNP-l-ala were resolved at R(s) of 2.75 and 2.16 within 90 min at a flow rate of 0.4 ml/min. We believe that the compact type-I coil planet centrifuge has a high analytical potential. Published by Elsevier B.V.

  13. Continuous counter-current chromatography for capture and polishing steps in biopharmaceutical production.

    Science.gov (United States)

    Steinebach, Fabian; Müller-Späth, Thomas; Morbidelli, Massimo

    2016-09-01

    The economic advantages of continuous processing of biopharmaceuticals, which include smaller equipment and faster, efficient processes, have increased interest in this technology over the past decade. Continuous processes can also improve quality assurance and enable greater controllability, consistent with the quality initiatives of the FDA. Here, we discuss different continuous multi-column chromatography processes. Differences in the capture and polishing steps result in two different types of continuous processes that employ counter-current column movement. Continuous-capture processes are associated with increased productivity per cycle and decreased buffer consumption, whereas the typical purity-yield trade-off of classical batch chromatography can be surmounted by continuous processes for polishing applications. In the context of continuous manufacturing, different but complementary chromatographic columns or devices are typically combined to improve overall process performance and avoid unnecessary product storage. In the following, these various processes, their performances compared with batch processing and resulting product quality are discussed based on a review of the literature. Based on various examples of applications, primarily monoclonal antibody production processes, conclusions are drawn about the future of these continuous-manufacturing technologies. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Purification of Active Myrosinase from Plants by Aqueous Two-Phase Counter-Current Chromatography

    Science.gov (United States)

    Wade, Kristina L.; Ito, Yoichiro; Ramarathnam, Aarthi; Holtzclaw, W. David; Fahey, Jed W.

    2014-01-01

    Introduction Myrosinase (thioglucoside glucohydrolase; E.C. 3.2.1.147), is a plant enzyme of increasing interest and importance to the biomedical community. Myrosinase catalyses the formation of isothiocyanates such as sulforaphane (frombroccoli) and 4-(α-l-rhamnopyranosyloxy)benzyl isothiocyanate (from moringa), which are potent inducers of the cytoprotective phase-2 response in humans, by hydrolysis of their abundant glucosinolate (β-thioglucoside N-hydroxysulphate) precursors. Objective To develop an aqueous two-phase counter-current chromatography (CCC) system for the rapid, three-step purification of catalytically active myrosinase. Methods A high-concentration potassium phosphate and polyethylene glycol biphasic aqueous two-phase system (ATPS) is used with a newly developed CCC configuration that utilises spiral-wound, flat-twisted tubing (with an ovoid cross-section). Results Making the initial crude plant extract directly in the ATPS and injecting only the lower phase permitted highly selective partitioning of the myrosinase complex before a short chromatography on a spiral disk CCC. Optimum phase retention and separation of myrosinase from other plant proteins afforded a 60-fold purification. Conclusion Catalytically active myrosinase is purified from 3-day broccoli sprouts, 7-day daikon sprouts, mustard seeds and the leaves of field-grown moringa trees, in a CCC system that is predictably scalable. PMID:25130502

  15. Purification of active myrosinase from plants by aqueous two-phase counter-current chromatography.

    Science.gov (United States)

    Wade, Kristina L; Ito, Yoichiro; Ramarathnam, Aarthi; Holtzclaw, W David; Fahey, Jed W

    2015-01-01

    Myrosinase (thioglucoside glucohydrolase; E.C. 3.2.1.147), is a plant enzyme of increasing interest and importance to the biomedical community. Myrosinase catalyses the formation of isothiocyanates such as sulforaphane (from broccoli) and 4-(α-l-rhamnopyranosyloxy)benzyl isothiocyanate (from moringa), which are potent inducers of the cytoprotective phase-2 response in humans, by hydrolysis of their abundant glucosinolate (β-thioglucoside N-hydroxysulphate) precursors. To develop an aqueous two-phase counter-current chromatography (CCC) system for the rapid, three-step purification of catalytically active myrosinase. A high-concentration potassium phosphate and polyethylene glycol biphasic aqueous two-phase system (ATPS) is used with a newly developed CCC configuration that utilises spiral-wound, flat-twisted tubing (with an ovoid cross-section). Making the initial crude plant extract directly in the ATPS and injecting only the lower phase permitted highly selective partitioning of the myrosinase complex before a short chromatography on a spiral disk CCC. Optimum phase retention and separation of myrosinase from other plant proteins afforded a 60-fold purification. Catalytically active myrosinase is purified from 3-day broccoli sprouts, 7-day daikon sprouts, mustard seeds and the leaves of field-grown moringa trees, in a CCC system that is predictably scalable. Copyright © 2014 John Wiley & Sons, Ltd.

  16. Topsy-turvy: Turning the counter-current heat exchange of leatherback turtles upside down

    Science.gov (United States)

    Davenport, John; Jones, T. Todd; Work, Thierry M.; Balazs, George H.

    2015-01-01

    Counter-current heat exchangers associated with appendages of endotherms feature bundles of closely applied arteriovenous vessels. The accepted paradigm is that heat from warm arterial blood travelling into the appendage crosses into cool venous blood returning to the body. High core temperature is maintained, but the appendage functions at low temperature. Leatherback turtles have elevated core temperatures in cold seawater and arteriovenous plexuses at the roots of all four limbs. We demonstrate that plexuses of the hindlimbs are situated wholly within the hip musculature, and that, at the distal ends of the plexuses, most blood vessels supply or drain the hip muscles, with little distal vascular supply to, or drainage from the limb blades. Venous blood entering a plexus will therefore be drained from active locomotory muscles that are overlaid by thick blubber when the adults are foraging in cold temperate waters. Plexuses maintain high limb muscle temperature and avoid excessive loss of heat to the core, the reverse of the accepted paradigm. Plexuses protect the core from overheating generated by muscular thermogenesis during nesting.

  17. Pulsed counter-current ultrasound-assisted extraction and characterization of polysaccharides from Boletus edulis.

    Science.gov (United States)

    You, Qinghong; Yin, Xiulian; Ji, Chaowen

    2014-01-30

    Four methods for extracting polysaccharides from Boletus edulis, namely, hot-water extraction, ultrasonic clearer extraction, static probe ultrasonic extraction, and pulsed counter-current probe ultrasonic extraction (CCPUE), were studied. Results showed that CCPUE has the highest extraction efficiency among the methods studied. Under optimal CCPUE conditions, a B. edulis polysaccharide (BEP) yield of 8.21% was obtained. Three purified fractions, BEP-I, BEP-II, and BEP-III, were obtained through sequential purification by DEAE-52 and Sephadex G-75 chromatography. The average molecular weights of BEP-I, BEP-II, and BEP-III were 10,278, 23,761, and 42,736 Da, respectively. The polysaccharides were mainly composed of xylose, mannose, galactose, and glucose; of these, mannose contents were the highest. The antioxidant activities of the BEPs were further investigated by measurement of their ability to scavenge DPPH and hydroxyl radicals as well as their reducing power. The results indicated that the BEPs have good antioxidant activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Destabilization of counter-propagating TAEs by off-axis, co-current Neutral Beam Injection

    Science.gov (United States)

    Podesta', M.; Fredrickson, E.; Gorelenkova, M.

    2017-10-01

    Neutral Beam injection (NBI) is a common tool to heat the plasma and drive current non-inductively in fusion devices. Energetic particles (EP) resulting from NBI can drive instabilities that are detrimental for the performance and the predictability of plasma discharges. A broad NBI deposition profile, e.g. by off-axis injection aiming near the plasma mid-radius, is often assumed to limit those undesired effects by reducing the radial gradient of the EP density, thus reducing the ``universal'' drive for instabilities. However, this work presents new evidence that off-axis NBI can also lead to undesired effects such as the destabilization of Alfvénic instabilities, as observed in NSTX-U plasmas. Experimental observations indicate that counter propagating toroidal AEs are destabilized as the radial EP density profile becomes hollow as a result of off-axis NBI. Time-dependent analysis with the TRANSP code, augmented by a reduced fast ion transport model (known as kick model), indicates that instabilities are driven by a combination of radial and energy gradients in the EP distribution. Understanding the mechanisms for wave-particle interaction, revealed by the phase space resolved analysis, is the basis to identify strategies to mitigate or suppress the observed instabilities. Work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences under Contract Number DE-AC02-09CH11466.

  19. A novel current mode operating beam counter based on not preamplified HPDs

    CERN Document Server

    Fujiwara, M.C.

    2002-01-01

    A novel system to monitor the intensity and the stability of a bunched beam of $\\simeq 1.2\\times 10^{7}$ antiprotons ($\\bar{p}$s) with a length of $\\simeq$ 250 ns (FWHM) and to measure its trapping efficiency in a Penning trap is described. This system operates parasitically detecting the pions from the annihilation of part of the beam in a degrader. Six plastic scintillators have been coupled from one side to six proximity focused HPDs without preamplifiers and operating in current mode. This device works in the stray field of the ATHENA magnet with no loss of efficiency; the gain can be varied from zero to a few thousands with a precision better than 0.1% and the dynamic range is larger than 8 orders of magnitude. Linearity and stability have been measured up to charge responses of 100 nC, corresponding to the beam completely dumped. The beam counter has been calibrated in two different and independent ways giving consistent results.

  20. Preparative Separation of Phenolic Compounds from Halimodendron halodendron by High-Speed Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Zhu Yu

    2010-08-01

    Full Text Available Three phenolic compounds, p-hydroxybenzoic acid (1, isorhamnetin-3-O-β-D-rutinoside (2, and 3,3'-di-O-methylquercetin (5, along with a phenolic mixture were successfully separated from the ethyl acetate crude extract of Halimodendron halodendron by high-speed counter-current chromatography (HSCCC with chloroform-methanol-water-acetic acid (4:3:2:0.05, v/v as the two-phase solvent system. The phenolic mixture from HSCCC was further separated by preparative HPLC and purified by Sephadex LH-20 to afford quercetin (3 and 3-O-methylquercetin (4. Seven hundred mg of ethyl acetate crude extract was separated by HSCCC to obtain six fractions which were then analyzed by high performance liquid chromatography (HPLC. The HSCCC separation obtained total of 80 mg of the mixture of quercetin (3 and 3-O-methylquercetin (4 (26.43% and 71.89%, respectively in fraction 2, 14 mg of 3,3'-di-O-methylquercetin (5 at 95.14% of purity in fraction 3, 15 mg of p-hydroxybenzoic acid (1 at 92.83% of purity in fraction 5, 12 mg of isorhamnetin-3-O-β-D-rutinoside (2 at 97.99% of purity in fraction 6. This is the first time these phenolic compounds have been obtained from H. halodendron, and their chemical structures identified by means of physicochemical and spectrometric analysis.

  1. Preparative separation of phenolic compounds from Halimodendron halodendron by high-speed counter-current chromatography.

    Science.gov (United States)

    Wang, Jihua; Gao, Haifeng; Zhao, Jianglin; Wang, Qi; Zhou, Ligang; Han, Jianguo; Yu, Zhu; Yang, Fuyu

    2010-08-31

    Three phenolic compounds, p-hydroxybenzoic acid (1), isorhamnetin-3-O-β-D-rutinoside (2), and 3,3'-di-O-methylquercetin (5), along with a phenolic mixture were successfully separated from the ethyl acetate crude extract of Halimodendron halodendron by high-speed counter-current chromatography (HSCCC) with chloroform-methanol-water-acetic acid (4:3:2:0.05, v/v) as the two-phase solvent system. The phenolic mixture from HSCCC was further separated by preparative HPLC and purified by Sephadex LH-20 to afford quercetin (3) and 3-O-methylquercetin (4). Seven hundred mg of ethyl acetate crude extract was separated by HSCCC to obtain six fractions which were then analyzed by high performance liquid chromatography (HPLC). The HSCCC separation obtained total of 80 mg of the mixture of quercetin (3) and 3-O-methylquercetin (4) (26.43% and 71.89%, respectively) in fraction 2, 14 mg of 3,3'-di-O-methylquercetin (5) at 95.14% of purity in fraction 3, 15 mg of p-hydroxybenzoic acid (1) at 92.83% of purity in fraction 5, 12 mg of isorhamnetin-3-O-β-D-rutinoside (2) at 97.99% of purity in fraction 6. This is the first time these phenolic compounds have been obtained from H. halodendron, and their chemical structures identified by means of physicochemical and spectrometric analysis.

  2. Coastal counter-currents setup patterns in the Gulf of Cadiz

    Science.gov (United States)

    Relvas, P.; Juniór, L.; Garel, E.; Drago, T.

    2017-12-01

    Alongshore coastal counter-currents (CCC) are frequent features of Eastern Boundary Upwelling Systems, where they temporally alternate with upwelling driven jets of opposite direction. Along the northern margin of the Gulf of Cadiz inner shelf, these CCCs are oriented poleward (eastward) and responsible for sharp temperature increases during the upwelling season, along with potential decline in water quality at the coast. This research is based on a multi-year ADCP velocity time-series (2008-2017), recorded at a single location (23 m water depth) over 13 deployments up to 3 months-long. The analysis focuses on the water column alongshore velocities during current inversions (i.e., the transition from equatorward upwelling jets to poleward CCCs). A set of parameters were derived from the flow structure to identify distinct types of inversions and to hypothesize about their driving mechanisms. Results show that 77% of the inversions start near the bed, propagating then to the upper layers. The bottom layer also changes direction before the surface layer for most events (71%). The vertical shear in this case is one order of magnitude greater than in the (less frequent) opposite situation. No seasonal variability is observed in the CCC occurrences. However, the parameters analysed in this study suggest different types of inversion between winter and summer. In winter, inversions are well defined (low variability), with similar patterns near the surface and bed layers as a result of a strong barotropic component. In summer the inversion patterns are more variable. In particular, the upper and bed layers are often importantly decoupled during inversions, indicating the strengthening of baroclinicity. A categorization of inversions events is proposed based on cross-correlation and multi-variable analyses of the developed parameters. Various types of inversion are obtained, suggesting that CCCs are driven by different forcings that may act separately or jointly.

  3. Experimental investigation of droplet separation in a horizontal counter-current air/water stratified flow

    International Nuclear Information System (INIS)

    Gabriel, Stephan Gerhard

    2015-01-01

    A stratified counter-current two-phase gas/liquid flow can occur in various technical systems. In the past investigations have mainly been motivated by the possible occurrence of these flows in accident scenarios of nuclear light water-reactors and in numerous applications in process engineering. However, the precise forecast of flow parameters, is still challenging, for instance due to their strong dependency on the geometric boundary conditions. A new approach which uses CFD methods (Computational Fluid Dynamics) promises a better understanding of the flow phenomena and simultaneously a higher scalability of the findings. RANS methods (Reynolds Averaged Navier Stokes) are preferred in order to compute industrial processes and geometries. A very deep understanding of the flow behavior and equation systems based on real physics are necessary preconditions to develop the equation system for a reliable RANS approach with predictive power. Therefore, local highly resolved, experimental data is needed in order to provide and validate the required turbulence and phase interaction models. The central objective of this work is to provide the data needed for the code development for these unsteady, turbulent and three-dimensional flows. Experiments were carried out at the WENKA facility (Water Entrainment Channel Karlsruhe) at the Karlsruhe Institute of Technology (KIT). The work consists of a detailed description of the test-facility including a new bended channel, the measurement techniques and the experimental results. The characterization of the new channel was done by flow maps. A high-speed imaging study gives an impression of the occurring flow regimes, and different flow phenomena like droplet separation. The velocity distributions as well as various turbulence values were investigated by particle image velocimetry (PIV). In the liquid phase fluorescent tracer-particles were used to suppress optical reflections from the phase surface (fluorescent PIV, FPIV

  4. Novel design for centrifugal counter-current chromatography: VI. Ellipsoid column.

    Science.gov (United States)

    Gu, Dongyu; Yang, Yi; Xin, Xuelei; Aisa, Haji Akber; Ito, Yoichiro

    2015-01-01

    A novel ellipsoid column was designed for centrifugal counter-current chromatography. Performance of the ellipsoid column with a capacity of 3.4 mL was examined with three different solvent systems composed of 1-butanol-acetic acid-water (4:1:5, v/v) (BAW), hexane-ethyl acetate-methanol-0.1 M HCl (1:1:1:1, v/v) (HEMH), and 12.5% (w/w) PEG1000 and 12.5% (w/w) dibasic potassium phosphate in water (PEG-DPP) each with suitable test samples. In dipeptide separation with BAW system, both stationary phase retention (Sf) and peak resolution (Rs) of the ellipsoid column were much higher at 0° column angle (column axis parallel to the centrifugal force) than at 90° column angle (column axis perpendicular to the centrifugal force), where elution with the lower phase at a low flow rate produced the best separation yielding Rs at 2.02 with 27.8% Sf at a flow rate of 0.07 ml/min. In the DNP-amino acid separation with HEMW system, the best results were obtained at a flow rate of 0.05 ml/min with 31.6% Sf yielding high Rs values at 2.16 between DNP-DL-glu and DNP-β-ala peaks and 1.81 between DNP-β-ala and DNP-L-ala peaks. In protein separation with PEG-DPP system, lysozyme and myolobin were resolved at Rs of 1.08 at a flow rate of 0.03 ml/min with 38.9% Sf. Most of those Rs values exceed those obtained from the figure-8 column under similar experimental conditions previously reported.

  5. A comparison of co-current and counter-current modes of operation for a novel hydrogen-permselective membrane dual-type FTS reactor in GTL technology

    Energy Technology Data Exchange (ETDEWEB)

    Rahimpour, M.R.; Forghani, A.A.; Mostafazadeh, A. Khosravanipour; Shariati, A. [Chemical Engineering Department, School of Chemical and Petroleum Engineering, Shiraz University, Shiraz 71345 (Iran)

    2010-01-15

    In this work, a comparison of co-current and counter-current modes of operation for a novel hydrogen-permselective membrane reactor for Fischer-Tropsch Synthesis (FTS) has been carried out. In both modes of operations, a system with two-catalyst bed instead of one single catalyst bed is developed for FTS reactions. In the first catalytic reactor, the synthesis gas is partly converted to products in a conventional water-cooled fixed-bed reactor, while in the second reactor which is a membrane fixed-bed reactor, the FTS reactions are completed and heat of reaction is used to preheat the feed synthesis gas to the first reactor. In the co-current mode, feed gas is entered into the tubes of the second reactor in the same direction with the reacting gas stream in shell side while in the counter-current mode the gas streams are in the opposite direction. Simulation results for both co-current and counter-current modes have been compared in terms of temperature, gasoline and CO{sub 2} yields, H{sub 2} and CO conversion, selectivity of components as well as permeation rate of hydrogen through the membrane. The results showed that the reactor in the co-current configuration operates with lower conversion and lower permeation rate of hydrogen, but it has more favorable profile of temperature. The counter-current mode of operation decreases undesired products such as CO{sub 2} and CH{sub 4} and also produces more gasoline. (author)

  6. Linear and nonlinear instability in vertical counter-current laminar gas-liquid flows

    Science.gov (United States)

    Schmidt, Patrick; Ó Náraigh, Lennon; Lucquiaud, Mathieu; Valluri, Prashant

    2016-04-01

    We consider the genesis and dynamics of interfacial instability in vertical gas-liquid flows, using as a model the two-dimensional channel flow of a thin falling film sheared by counter-current gas. The methodology is linear stability theory (Orr-Sommerfeld analysis) together with direct numerical simulation of the two-phase flow in the case of nonlinear disturbances. We investigate the influence of two main flow parameters on the interfacial dynamics, namely the film thickness and pressure drop applied to drive the gas stream. To make contact with existing studies in the literature, the effect of various density contrasts is also examined. Energy budget analyses based on the Orr-Sommerfeld theory reveal various coexisting unstable modes (interfacial, shear, internal) in the case of high density contrasts, which results in mode coalescence and mode competition, but only one dynamically relevant unstable interfacial mode for low density contrast. A study of absolute and convective instability for low density contrast shows that the system is absolutely unstable for all but two narrow regions of the investigated parameter space. Direct numerical simulations of the same system (low density contrast) show that linear theory holds up remarkably well upon the onset of large-amplitude waves as well as the existence of weakly nonlinear waves. For high density contrasts, corresponding more closely to an air-water-type system, linear stability theory is also successful at determining the most-dominant features in the interfacial wave dynamics at early-to-intermediate times. Nevertheless, the short waves selected by the linear theory undergo secondary instability and the wave train is no longer regular but rather exhibits chaotic motion. The same linear stability theory predicts when the direction of travel of the waves changes — from downwards to upwards. We outline the practical implications of this change in terms of loading and flooding. The change in direction of the

  7. Separation and purification of polyphenols from red wine extracts using high speed counter current chromatography.

    Science.gov (United States)

    Li, Yuanyuan; Li, Lingxi; Cui, Yan; Zhang, Shuting; Sun, Baoshan

    2017-06-01

    Polyphenols are important compounds of red wine owing to their contribution to sensory properties and antioxidant activities. In this study, high-speed counter-current chromatography (HSCCC) coupled with semi-preparative HPLC was used for large-scale separation and purification of polyphenols from red wine extracts. With the solvent system of hexane-ethyl acetate-water (1-50-50), various oligomeric procyanidins including monomer catechin, epicatechin, dimers B1, B2; phenolic acids including coutaric acid, caftaric acid and other type of polyphenols were largely separated within 370min and most of these compounds presented high yields (0.97mg to 13.79mg) with high purity (90.34% to 98.91%) after the semi-preparative HPLC isolation. Using the solvent system of Methyl tert-Butyl Ether (MTBE) - n-butyl alcohol- acetonitrile-water (1-40-1-50, acidified with 0.01% trifluoroacetic acid (TFA)) by one-step HSCCC of 100mg of the red wine extracts, the major anthocyanins, i.e., malvidin-3-O-glucoside, delphinidin-3-O-glucoside and peonidin-3-O-glucoside, as well as two polymeric proanthocyanidin fractions were successfully separated one another within 320min. The yields of malvidin-3-O-glucoside, delphinidin-3-O-glucoside and peonidin-3-O-glucoside were 12.12mg, 1.78mg and 11.57mg with the purity of 92.74%, 91.03% and 91.21%, respectively. Thiolysis-UPLC analysis indicated that the two polymeric proanthocyanidin fractions presented high purity, with mean degree of polymerization of 7.66±0.12 and 6.20±0.09, respectively. The further experiments on the antioxidant activities by DPPH radical test, FRAP assay and ABTS method showed that all of the isolated procyandins and anthocyanins and the two polymeric proanthocyanidin fractions, with exception of phenolic acids possessed much greater antioxidant activities compared to standard Trolox andl-ascorbic acid (2-14 times). Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Linear and nonlinear instability in vertical counter-current laminar gas-liquid flows

    International Nuclear Information System (INIS)

    Schmidt, Patrick; Lucquiaud, Mathieu; Valluri, Prashant; Ó Náraigh, Lennon

    2016-01-01

    We consider the genesis and dynamics of interfacial instability in vertical gas-liquid flows, using as a model the two-dimensional channel flow of a thin falling film sheared by counter-current gas. The methodology is linear stability theory (Orr-Sommerfeld analysis) together with direct numerical simulation of the two-phase flow in the case of nonlinear disturbances. We investigate the influence of two main flow parameters on the interfacial dynamics, namely the film thickness and pressure drop applied to drive the gas stream. To make contact with existing studies in the literature, the effect of various density contrasts is also examined. Energy budget analyses based on the Orr-Sommerfeld theory reveal various coexisting unstable modes (interfacial, shear, internal) in the case of high density contrasts, which results in mode coalescence and mode competition, but only one dynamically relevant unstable interfacial mode for low density contrast. A study of absolute and convective instability for low density contrast shows that the system is absolutely unstable for all but two narrow regions of the investigated parameter space. Direct numerical simulations of the same system (low density contrast) show that linear theory holds up remarkably well upon the onset of large-amplitude waves as well as the existence of weakly nonlinear waves. For high density contrasts, corresponding more closely to an air-water-type system, linear stability theory is also successful at determining the most-dominant features in the interfacial wave dynamics at early-to-intermediate times. Nevertheless, the short waves selected by the linear theory undergo secondary instability and the wave train is no longer regular but rather exhibits chaotic motion. The same linear stability theory predicts when the direction of travel of the waves changes — from downwards to upwards. We outline the practical implications of this change in terms of loading and flooding. The change in direction of the

  9. Preparative Separation of Six Rhynchophylla Alkaloids from Uncaria macrophylla Wall by pH-Zone Refining Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Qinghai Zhang

    2013-12-01

    Full Text Available pH-Zone refining counter-current chromatography was successfully applied to the preparative isolation and purification of six alkaloids from the ethanol extracts of Uncaria macrophylla Wall. Because of the low content of alkaloids (about 0.2%, w/w in U. macrophylla Wall, the target compounds were enriched by pH-zone refining counter-current chromatography using a two-phase solvent system composed of petroleum ether–ethyl acetate–isopropanol–water (2:6:3:9, v/v, adding 10 mM triethylamine in organic stationary phase and 5 mM hydrochloric acid in aqueous mobile phase. Then pH-zone refining counter-current chromatography using the other two-phase solvent system was used for final purification. Six target compounds were finally isolated and purified by following two-phase solvent system composed of methyl tert-butyl ether (MTBE–acetonitrile–water (4:0.5:5, v/v, adding triethylamine (TEA (10 mM to the organic phase and HCl (5 mM to aqueous mobile phase. The separation of 2.8 g enriched total alkaloids yielded 36 mg hirsutine, 48 mg hirsuteine, 82 mg uncarine C, 73 mg uncarine E, 163 mg rhynchophylline, and 149 mg corynoxeine, all with purities above 96% as verified by HPLC Their structures were identified by electrospray ionization-mass spectrometry (ESI-MS and 1H-NMR spectroscopy.

  10. Preparative separation of six rhynchophylla alkaloids from Uncaria macrophylla wall by pH-zone refining counter-current chromatography.

    Science.gov (United States)

    Zhang, Qinghai; Lin, Changhu; Duan, Wenjuan; Wang, Xiao; Luo, Aiqin

    2013-12-12

    pH-Zone refining counter-current chromatography was successfully applied to the preparative isolation and purification of six alkaloids from the ethanol extracts of Uncaria macrophylla Wall. Because of the low content of alkaloids (about 0.2%, w/w) in U. macrophylla Wall, the target compounds were enriched by pH-zone refining counter-current chromatography using a two-phase solvent system composed of petroleum ether-ethyl acetate-isopropanol-water (2:6:3:9, v/v), adding 10 mM triethylamine in organic stationary phase and 5 mM hydrochloric acid in aqueous mobile phase. Then pH-zone refining counter-current chromatography using the other two-phase solvent system was used for final purification. Six target compounds were finally isolated and purified by following two-phase solvent system composed of methyl tert-butyl ether (MTBE)-acetonitrile-water (4:0.5:5, v/v), adding triethylamine (TEA) (10 mM) to the organic phase and HCl (5 mM) to aqueous mobile phase. The separation of 2.8 g enriched total alkaloids yielded 36 mg hirsutine, 48 mg hirsuteine, 82 mg uncarine C, 73 mg uncarine E, 163 mg rhynchophylline, and 149 mg corynoxeine, all with purities above 96% as verified by HPLC Their structures were identified by electrospray ionization-mass spectrometry (ESI-MS) and 1H-NMR spectroscopy.

  11. 3D Numerical Study of Multiphase Counter-Current Flow within a Packed Bed for Post Combustion Carbon Dioxide Capture

    Directory of Open Access Journals (Sweden)

    Li Yang

    2018-06-01

    Full Text Available The hydrodynamics within counter-current flow packed beds is of vital importance to provide insight into the design and operational parameters that may impact reactor and reaction efficiencies in processes used for post combustion CO2 capture. However, the multiphase counter-current flows in random packing used in these processes are complicated to visualize. Hence, this work aimed at developing a computational fluid dynamics (CFD model to study more precisely the complex details of flow inside a packed bed. The simulation results clearly demonstrated the development of, and changes in, liquid distributions, wetted areas, and film thickness under various gas and liquid flow rates. An increase in values of the We number led to a more uniform liquid distribution, and the flow patterns changed from droplet flow to film flow and trickle flow as the We number was increased. In contrast, an increase in gas flow rate had no significant effect on the wetted areas and liquid holdup. It was also determined that the number of liquid inlets affected flow behavior, and the liquid surface tension had an insignificant influence on pressure drop or liquid holdup; however, lower surface tension provided a larger wetted area and a thinner film. An experimental study, performed to enable comparisons between experimentally measured pressure drops and simulation-determined pressure drops, showed close correspondence and similar trends between the experimental data and the simulation data; hence, it was concluded that the simulation model was validated and could reasonably predict flow dynamics within a counter-current flow packed bed.

  12. Isolation of xanthyletin, an inhibitor of ants' symbiotic fungus, by high-speed counter-current chromatography.

    Science.gov (United States)

    Cazal, Cristiane de Melo; Domingues, Vanessa de Cássia; Batalhão, Jaqueline Raquel; Bueno, Odair Corrêa; Filho, Edson Rodrigues; da Silva, Maria Fátima G Fernandes; Vieira, Paulo Cezar; Fernandes, João Batista

    2009-05-08

    Xanthyletin, an inhibitor of symbiotic fungus (Leucoagaricus gongylophorus) of leaf-cutting ant (Atta sexdens rubropilosa), as well as suberosin, seselin and xanthoxyletin were isolated from Citrus sinensis grafted on Citrus limonia. A two-phase solvent system composed of hexane/ethanol/acetonitrile/water (10:8:1:1, v/v) was used for the high-speed counter-current chromatographic isolation of xanthyletin with high yield and over 99% purity as determined by liquid and gas chromatography with mass spectrometry detection. Identifications were performed by UV spectra, IR spectra, (1)H NMR and (13)C NMR.

  13. Preparative separation of flavonoids from the medicinal plant Davilla elliptica St. Hill. by high-speed counter-current chromatography

    OpenAIRE

    Rinaldo Daniel; Silva Marcelo Aparecido; Rodrigues Clenilson Martins; Calvo Tamara Regina; Sannomiya Miriam; Santos Lourdes Campaner dos; Vilegas Wagner; Kushima Hélio; Hiruma-Lima Clélia Akiko; Brito Alba Regina Monteiro de Souza

    2006-01-01

    High-speed counter-current chromatography (HSCCC) is a major tool for the fast separation of natural products from plants. It was used for the preparative isolation of the flavonoid monoglucosides present in the aerial parts of the Davilla elliptica St. Hill. (Dilleniaceae). This species is used in Brazilian folk medicine for the treatment of gastric disorders. The optimum solvent system used was composed of a mixture of ethyl acetate-n-propanol-water (140:8:80, v/v/v) and led to a successful...

  14. ISOLATION OF GLYCOSIDES FROM THE BARKS OF ILEX ROTUNDA BY HIGH-SPEED COUNTER-CURRENT CHROMATOGRAPHY

    OpenAIRE

    Wang, Chun; Chao, Zhimao; Sun, Wen; Wu, Xiaoyi; Ito, Yoichiro

    2013-01-01

    Semi-preparative and preparative high-speed counter-current chromatography (HSCCC) were successfully used for isolation of glycosides from 50% ethanol extract of the dried barks of Ilex rotunda Thunb. (Aquifoliaceae) by using a two-phase solvent system composed of ethyl acetate-n-butanol-water (1:6:7, v/v/v). From 1.0 g of the extract, syringaresinol 4',4"-di-o-β-d-glucopyranoside (I, 20.2 mg),, syringin (II, 56.8 mg), sinapaldehyde glucoside (III, 26.2 mg),, syringaresinol 4'-o-β-d-glucopyra...

  15. Counter-current extraction studies for the recovery of neptunium by the Purex process. Part II

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, N.; Nadkarni, M. N.; Kumar, S. V.; Kartha, P. K.S.; Sonavane, R. R.; Ramaniah, M. V.; Patil, S. K.

    1974-07-01

    Counter-extraction experiments were carried out under the conditions relevant to the partitioning column (IBX) in the purex process to know the path of neptunium present as Np (VI) the organic phase during the partitioning step. The results obtained show that when ferrous sulphamates is used as the reducing agent, most of the neptunium continues to remain with uranium in the organic stream while with hydrazine stabilized uranous nitrate as the reducing agent, a major fraction of neptunium follows the aqueous stream. Mixer-settler experiments were also carried out under the conditions relevant to the uranium purification cycle (2D) to establish the conditions for forcing neptunium to the aqueous raffinate or for partitioning it from uranium if both neptunium and uranium are co-extracted in this cycle and the results obtained are reported here. (auth)

  16. Counter-current acid leaching process for the removal of Cu, Pb, Sb and Zn from shooting range soil.

    Science.gov (United States)

    Lafond, Stéphanie; Blais, Jean-François; Mercier, Guy; Martel, Richard

    2013-01-01

    This research explores the performance of a counter-current leaching process (CCLP) for Cu, Pb, Sb and Zn extraction in a polluted shooting range soil. The initial metal concentrations in the soil were 1790 mg Cu/kg, 48,300 mg Pb/kg, 840 mg Sb/kg and 368 mg Zn/kg. The leaching process consisted of five one-hour acid leaching steps, which used 1 M H2SO4 + 4 M NaCl (20 degrees C, soil suspension = 100 g/L) followed by two water rinsing steps. Ten counter-current remediation cycles were completed and the average metal removal yields were 98.3 +/- 0.3% of Cu, 99.5 +/- 0.1% of Pb, 75.5 +/- 5.1% of Sb and 29.1 +/- 27.2% of Zn. The quality of metal leaching did not deteriorate throughout the 10 remediation cycles completed for this study. The CCLP reduced acid and salt use by approximately 68% and reduced water consumption by approximately 60%, exceeding reductions achieved by a standard acid leaching process.

  17. Isolation and purification of arctigenin from Fructus Arctii by enzymatic hydrolysis combined with high-speed counter-current chromatography.

    Science.gov (United States)

    Liu, Feng; Xi, Xingjun; Wang, Mei; Fan, Li; Geng, Yanling; Wang, Xiao

    2014-02-01

    Enzymatic hydrolysis pretreatment combined with high-speed counter-current chromatography for the transformation and isolation of arctigenin from Fructus Arctii was successfully developed. In the first step, the extract solution of Fructus Arctii was enzymatic hydrolyzed by β-glucosidase. The optimal hydrolysis conditions were 40°C, pH 5.0, 24 h of hydrolysis time, and 1.25 mg/mL β-glucosidase concentration. Under these conditions, the content of arctigenin was transformed from 2.60 to 12.59 mg/g. In the second step, arctigenin in the hydrolysis products was separated and purified by high-speed counter-current chromatography with a two-phase solvent system composed of petroleum ether/ethyl acetate/methanol/water (10:25:15:20, v/v), and the fraction was analyzed by HPLC, ESI-MS, and (1)H NMR spectroscopy. Finally, 102 mg of arctigenin with a purity of 98.9% was obtained in a one-step separation from 200 mg of hydrolyzed sample. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Simulation of counter-current imbibition in water-wet fractured reservoirs based on discrete-fracture model

    Directory of Open Access Journals (Sweden)

    Wang Yueying

    2017-08-01

    Full Text Available Isolated fractures usually exist in fractured media systems, where the capillary pressure in the fracture is lower than that of the matrix, causing the discrepancy in oil recoveries between fractured and non-fractured porous media. Experiments, analytical solutions and conventional simulation methods based on the continuum model approach are incompetent or insufficient in describing media containing isolated fractures. In this paper, the simulation of the counter-current imbibition in fractured media is based on the discrete-fracture model (DFM. The interlocking or arrangement of matrix and fracture system within the model resembles the traditional discrete fracture network model and the hybrid-mixed-finite-element method is employed to solve the associated equations. The Behbahani experimental data validates our simulation solution for consistency. The simulation results of the fractured media show that the isolated-fractures affect the imbibition in the matrix block. Moreover, the isolated fracture parameters such as fracture length and fracture location influence the trend of the recovery curves. Thus, the counter-current imbibition behavior of media with isolated fractures can be predicted using this method based on the discrete-fracture model.

  19. Practice of the counter-current trickle leaching of uranium ore by refreshed liquor of bacterial oxidation

    International Nuclear Information System (INIS)

    Chen Shian; Huang Xiangfu; Fan Baotuan

    1995-01-01

    The uranium ore of the Mine No. 753 is a high-silicate type primary one, in which the tetravalent uranium accounts for 85%, and the uranium grade is in the range of 0.36% to 0.442%. To reduce the engineering investment and the operating cost a four-stage counter-current trickle leaching pilot-plant test was carried out with the leaching time 50 days and acid consumption 38 kg per ton of ore, and the recovery of more than 95% was obtained. Using the counter-current trickle leaching mode and controlling the limit concentration of the harmful matters in the bacterial leaching liquor, the latter can be effectively oxidized by the synchronical regeneration. A trickle leaching comparative test of 25 ton ore single heap also gave a good result of more than 95% in extraction rate, and 30% acid consumption was saved and the 2.0% pyrolusite (containing MnO 2 40%) was eliminated. This process is feasible in technology and worth-while in economy for treating the uranium ore of Mine No. 753, and provides a new method of uranium ore trickle leaching

  20. Scale and material effects on flame characteristics in small heat recirculation combustors of a counter-current channel type

    International Nuclear Information System (INIS)

    Lee, Min Jung; Cho, Sang Moon; Choi, Byung Il; Kim, Nam Il

    2010-01-01

    Small energy sources have been interested with the recent development of small-scale mechanical systems. With the purpose of developing a basic model of micro-combustors of heat recirculation, small combustors of a counter-current channel type were fabricated, and the premixed flame stabilization characteristics were investigated experimentally. Each combustor consists of a combustion space and a pair of counter-current channels for heat recirculation. The channel gap was less than the ordinary quenching distance of a stoichiometric methane-air premixed flame. Depending on the flame locations and structures, flame stabilization was classified into four modes: an ordinary mode, a channel mode, a radiation mode, and a well-stirred reaction mode. Base-scale combustors of stainless steel were initially examined. Additional half-scale combustors of stainless steel and quartz were fabricated and their flame stabilization conditions were compared. Consequently, a change of the material of the combustor significantly affected the flame stabilization compared to the effects of a scale-down design. A half-scale quartz combustor had a wide range of flame stabilization conditions. Surface temperatures and the composition of the emission gas were measured. At a higher flow rate, the combustor temperature increases and the light emission from the middle wall is enhanced to extend the flame stabilization conditions. The combustion efficiency and the composition of emitted gas were feasible. These results provide useful information for the design of small-scale combustors.

  1. Study of rare earth separation by counter current electromigration; Estudo da separacao de terras raras por eletromigracao em contra corrente

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Sergio Machado

    1995-08-01

    The counter current electromigration (CCEM) is an electrophoretic technique where the charged species migrate on an electrical field toward an electrolytic flux. Usually this electrolyte is a complexing agent and is necessary to increase the small differences between the species mobilities. A new column was developed, all made of acrylic, in a cylindrical shape. A set of experiments was carried out with the species Na{sup +}/K{sup +}, K{sup +}/Sm{sup +3}, K{sup +}/Eu{sup +3} and K{sup +}/Sm{sup +3}/Eu{sup +3} using the {alpha}-hydrox i-isobutyric acid o,01 M as the counter current electrolytic flux. From a synthetic mixture of 90% of samarium and 10% of europium was obtained the samarium ion in a purity better than 99,9% where the concentration of Eu was determined by the polarography technique. The potassium ion was used as a leading electrolyte. It was also measured the mobilities of the involved species in the {alpha}-HIBA medium. Two models are proposed, a stationary model and a dynamic one. A simulator of a simplified stationary model, prepared in FORTRAN language, was developed and tested toward experimental results. (author)

  2. Experimental investigation of flooding in air-water counter-current flow with a vertical adiabatic multi-rod bundle

    International Nuclear Information System (INIS)

    Chung, Bub Dong; Kim, Hho Jung; Cha, Jong Hee; Cho, Sung Jae; Chun, Moon Hyun

    1991-01-01

    The process of flooding phenomenon in a vertical adiabatic 3 x 3 tube bundle flow channel has been studied experimentally. A series of tests was performed, using three types of tube bundle differing only in the number of spacer grids attached, to investigate the effects of spacer grids and multi-flow channel interactions on the air-water counter-current flow limitations. Experimentally determined flooding points at various water film Reynolds numbers for three different test sections are presented in graphical form and compared with entrainment criterion for co-current flow and instability criteria. In addition, empirical flooding correlations of the Kutateladze type are obtained for each type of test section using liquid penetration data

  3. Study of semileptonic and leptonic neutral-current processes and of $\\mu$-polarization using counter techniques

    CERN Document Server

    2002-01-01

    .PP This experiment will study semileptonic neutral current neutrino interactions with nucleons, using principally the dichromatic neutrino beam N1 and will make measurements of the polarization of muons produced in the WA1 experiment by neutrino-nucleon interactions, using the horn-focused broad-band neutrino The main part of the apparatus is a fine-grained target calorimeter in which the energy and direction of the hadronic jet resulting from the neutrino scattering is measured by electronic techniques. It is supplemented by a muon detector and spectrometer. The fine-grained calorimeter is used as a polarimeter for muons produced in WA1. \\\\ \\\\ The calorimeter is composed of 13 modules, each 1.2 m long and 4~m x 4~m in cross section. A module consists of six 3 m x 3 m target plates made of 8 cm thick marble with 12 cm gaps for insertion of 20 scintillation counters of 15 cm width and 3 cm thickness, 128 proportional counters of 3~x~3~cm|2 cross-section and 4~m length, and 256 streamer tubes of 0.9~x~0.9~cm|2...

  4. Two-step purification of scutellarin from Erigeron breviscapus (vant.) Hand. Mazz. by high-speed counter-current chromatography.

    Science.gov (United States)

    Gao, Min; Gu, Ming; Liu, Chun-Zhao

    2006-07-11

    Scutellarin, a flavone glycoside, popularly applied for the treatment of cardiopathy, has been purified in two-step purification by high-speed counter-current chromatography (HSCCC) from Erigeron breviscapus (vant.) Hand. Mazz. (Deng-zhan-hua in Chinese), a well-known traditional Chinese medicinal plant for heart disease. Two solvent systems, n-hexane-ethyl acetate-methanol-acetic acid-water (1:6:1.5:1:4, v/v/v/v/v) and ethyl acetate-n-butanol-acetonitrile-0.1% HCl (5:2:5:10, v/v/v/v) were used for the two-step purification. The purity of the collected fraction of scutellarin was 95.6%. This study supplies a new alternative method for purification of scutellarin.

  5. ISOLATION OF GLYCOSIDES FROM THE BARKS OF ILEX ROTUNDA BY HIGH-SPEED COUNTER-CURRENT CHROMATOGRAPHY

    Science.gov (United States)

    Wang, Chun; Chao, Zhimao; Sun, Wen; Wu, Xiaoyi; Ito, Yoichiro

    2013-01-01

    Semi-preparative and preparative high-speed counter-current chromatography (HSCCC) were successfully used for isolation of glycosides from 50% ethanol extract of the dried barks of Ilex rotunda Thunb. (Aquifoliaceae) by using a two-phase solvent system composed of ethyl acetate-n-butanol-water (1:6:7, v/v/v). From 1.0 g of the extract, syringaresinol 4',4"-di-o-β-d-glucopyranoside (I, 20.2 mg),, syringin (II, 56.8 mg), sinapaldehyde glucoside (III, 26.2 mg),, syringaresinol 4'-o-β-d-glucopyranoside (IV, 20.4 mg), and pedunculoside (V, 45.1 mg) were obtained by one run of TBE-1000A HSCCC instrument with 1000 mL of column volume. Their structures were identified by IR, MS, and 1H and 13C NMR studies. Glycoside I was isolated from this plant for the first time. PMID:25132792

  6. Isolation and Purification of Oridonin from the Whole Plant of Isodon rubescens by High-Speed Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    ChunYue Yu

    2011-09-01

    Full Text Available Semi-preparative high-speed counter-current chromatography (HSCCC was successfully used for isolation and purification of oridonin from Isodon rubescens by using a two-phase-solvent system composed of n-hexane-ethyl acetate-methanol-water (2.8:5:2.8:5, v/v/v/v. The targeted compound isolated, collected and purified by HSCCC was analyzed by high performance liquid chromatography (HPLC. A total of 40.6 mg of oridonin with the purity of 73.5% was obtained in less than 100 min from 100 mg of crude Isodon rubescens extract. The chemical structure of the compound was identified by IR, 1H-NMR and 13C-NMR.

  7. Prediction of Counter-Current Flow Limitation at Hot Leg Pipe During a Small-Break Loca

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, H.Y. [Korea Electric Power Research Institute, Taejeon (Korea)

    2001-07-01

    The possibility of hot leg flooding during reflux condensation cooling after a small-break loss-of-coolant accident in a nuclear power plant is evaluated. The vapor and liquid velocities in hot leg and steam generator tubes are calculated during reflux condensation cooling with the accident scenarios of three typical break sizes, 0.13 %, 1.02 % and 10.19 % cold leg break. The effect of initial water level to counter-current flow limitation is taken into account. It is predicted that the hot leg flooding is precluded when all steam generators are available for heat removal. It is also shown the both hot leg flooding and SG flooding are possible under the operation of one steam generators. Therefore, it can be said that the occurrence of hot leg flooding under reflux condensation cooling is possible when the number of steam generators available for heat removal is limited. (author). 15 refs., 15 figs., 3 tabs.

  8. ISOLATION OF GLYCOSIDES FROM THE BARKS OF ILEX ROTUNDA BY HIGH-SPEED COUNTER-CURRENT CHROMATOGRAPHY.

    Science.gov (United States)

    Wang, Chun; Chao, Zhimao; Sun, Wen; Wu, Xiaoyi; Ito, Yoichiro

    2014-04-01

    Semi-preparative and preparative high-speed counter-current chromatography (HSCCC) were successfully used for isolation of glycosides from 50% ethanol extract of the dried barks of Ilex rotunda Thunb. (Aquifoliaceae) by using a two-phase solvent system composed of ethyl acetate-n-butanol-water (1:6:7, v/v/v). From 1.0 g of the extract, syringaresinol 4',4"-di-o-β-d-glucopyranoside ( I , 20.2 mg),, syringin ( II , 56.8 mg), sinapaldehyde glucoside ( III , 26.2 mg),, syringaresinol 4'-o-β-d-glucopyranoside ( IV , 20.4 mg), and pedunculoside ( V , 45.1 mg) were obtained by one run of TBE-1000A HSCCC instrument with 1000 mL of column volume. Their structures were identified by IR, MS, and 1 H and 13 C NMR studies. Glycoside I was isolated from this plant for the first time.

  9. Application of silver ion in the separation of macrolide antibiotic components by high-speed counter-current chromatography.

    Science.gov (United States)

    Wen, Yaoming; Wang, Jiaoyan; Chen, Xiuming; Le, Zhanxian; Chen, Yuxiang; Zheng, Wei

    2009-05-29

    Three macrolide antibiotic components - ascomycin, tacrolimus and dihydrotacrolimus - were separated and purified by silver ion high-speed counter-current chromatography (HSCCC). The solvent system consisted of n-hexane-tert-butyl methyl ether-methanol-water (1:3:6:5, v/v) and silver nitrate (0.10mol/l). The silver ion acted as a pi-complexing agent with tacrolimus because of its extra side double bond compared with ascomycin and dihydrotacrolimus. This complexation modified the partition coefficient values and the separation factors of the three components. As a result, ascomycin, tacrolimus and dihydrotacrolimus were purified from 150mg extracted crude sample with purities of 97.6%, 98.7% and 96.5%, respectively, and yields over 80% (including their tautomers). These results cannot be achieved with the same solvent system but without the addition of silver ion.

  10. Isolation and Purification of Two Isoflavones from Hericium erinaceum Mycelium by High-Speed Counter-Current Chromatography.

    Science.gov (United States)

    He, Jinzhe; Fan, Peng; Feng, Simin; Shao, Ping; Sun, Peilong

    2018-03-02

    High-speed counter-current chromatography (HSCCC) was used to separate and purify two isoflavones for the first time from Hericium erinaceum ( H. erinaceum ) mycelium using a two-phase solvent system composed of chloroform-dichloromethane-methanol-water (4:2:3:2, v / v / v / v ). These two isoflavones were identified as genistein (4',5,7-trihydroxyisoflavone, C 15 H 10 O₅) and daidzein (4',7-dihydroxyisoflavone, C 15 H 10 O₄), using infrared spectroscopy (IR), electro-spary ionisation mass (ESI-MS), ¹H-nuclear magnetic resonance (NMR) and 13 C-NMR spectra. About 23 mg genistein with 95.7% purity and 18 mg daidzein with 97.3% purity were isolated from 150 mg ethanolic extract of H. erinaceum mycelium. The results demonstrated that HSCCC was a feasible method to separate and purify genistein and daidzein from H. erinaceum mycelium.

  11. Improved separation with the intermittently pressed tubing of multilayer coil in type-I counter-current chromatography.

    Science.gov (United States)

    Yang, Yi; Yang, Jiao; Fang, Chen; Wang, Jihui; Gu, Dongyu; Tian, Jing; Ito, Yoichiro

    2018-05-25

    The intermittently pressed tubing was introduced in type-I counter-current chromatographic system as the separation column to improve the separation performance in the present study. The separations were performed with two different solvent systems composed of 1-butanol-acetic acid-water (4:1:5, v/v) (BAW) and hexane-ethyl acetate-methanol-0.1 M HCl (1:1:1:1, v/v) (HEMW) using dipeptides and DNP-amino acids as test samples, respectively. The chromatographic performance was evaluated in terms of retention of the stationary phase (Sf), theoretical plate (N) and peak resolution (Rs). In general, the type-I planetary motion with the multilayer coil of non-modified standard tubing can yield the best separation at a low revolution speed of 200 rpm with lower flow rate. The present results with intermittently pressed tubing indicated that the performance was also optimal at the revolution speed of 200 rpm where the lower flow rate was more beneficial to retention of stationary phase and resolution. In the moderately hydrophobic two-phase solvent system composed of hexane-ethyl acetate-metanol-0.1 M hydrochloric acid (1:1:1:1, v/v), DNP-amino acids were separated with Rs at 1.67 and 1.47, respectively, with 12.66% of stationary phase retention at a flow rate of 0.25 ml/min. In the polar solvent system composed of 1-butanol-acetic acid-water (4:1:5, v/v), dipeptide samples were resolved with Rs at 2.18 and 18.75% of stationary phase retention at a flow rate of 0.25 ml/min. These results indicate that the present system substantially improves the separation efficiency of type-I counter-current chromatographic system. Published by Elsevier B.V.

  12. Combinative application of pH-zone-refining and conventional high-speed counter-current chromatography for preparative separation of caged polyprenylated xanthones from gamboge.

    Science.gov (United States)

    Xu, Min; Fu, Wenwei; Zhang, Baojun; Tan, Hongsheng; Xiu, Yanfeng; Xu, Hongxi

    2016-02-01

    An efficient method for the preparative separation of four structurally similar caged xanthones from the crude extracts of gamboge was established, which involves the combination of pH-zone-refining counter-current chromatography and conventional high-speed counter-current chromatography for the first time. pH-zone-refining counter-current chromatography was performed with the solvent system composed of n-hexane/ethyl acetate/methanol/water (7:3:8:2, v/v/v/v), where 0.1% trifluoroacetic acid was added to the upper organic stationary phase as a retainer and 0.03% triethylamine was added to the aqueous mobile phase as an eluter. From 3.157 g of the crude extract, 1.134 g of gambogic acid, 180.5 mg of gambogenic acid and 572.9 mg of a mixture of two other caged polyprenylated xanthones were obtained. The mixture was further separated by conventional high-speed counter-current chromatography with a solvent system composed of n-hexane/ethyl acetate/methanol/water (5:5:10:5, v/v/v/v) and n-hexane/methyl tert-butyl ether/acetonitrile/water (8:2:6:4,v/v/v/v), yielding 11.6 mg of isogambogenic acid and 10.4 mg of β-morellic acid from 218.0 mg of the mixture, respectively. The purities of all four of the compounds were over 95%, as determined by high-performance liquid chromatography, and the chemical structures of the four compounds were confirmed by electrospray ionization mass spectrometry and NMR spectroscopy. The combinative application of pH-zone-refining counter-current chromatography and conventional high-speed counter-current chromatography shows great advantages in isolating and enriching the caged polyprenylated xanthones. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Scale-up of counter-current chromatography: demonstration of predictable isocratic and quasi-continuous operating modes from the test tube to pilot/process scale.

    Science.gov (United States)

    Sutherland, Ian; Hewitson, Peter; Ignatova, Svetlana

    2009-12-11

    Predictable scale-up from test tube derived distribution ratios and analytical-scale sample loading optimisation is demonstrated using a model sample system of benzyl alcohol and p-cresol in a heptane:ethyl acetate:methanol:water phase system with the new 18 L Maxi counter-current chromatography centrifuge. The versatility of having a liquid stationary phase with its high loading capacity and flexible operating modes is demonstrated at two different scales by separating and concentrating target compounds using a mixture of caffeine, vanillin, naringenin and carvone using a quasi-continuous technique called intermittent counter-current extraction.

  14. Study of Co-Current and Counter-Current Gas-Liquid Two-Phase Flow Through Packed Bed in Microgravity

    Science.gov (United States)

    Revankar, Shripad T.

    2002-11-01

    The main goal of the project is to obtain new experimental data and development of models on the co-current and counter-current gas-liquid two-phase flow through a packed bed in microgravity and characterize the flow regime transition, pressure drop, void and interfacial area distribution, and liquid hold up. Experimental data will be obtained for earth gravity and microgravity conditions. Models will be developed for the prediction of flow regime transition, void fraction distribution and interfacial area concentration, which are key parameters to characterize the packed bed performance. Thus the specific objectives of the proposed research are to: (1) Develop experiments for the study of the gas liquid two-phase flow through the packed bed with three different flow combinations: co-current down flow, co-current upflow and counter current flow. (2) Develop pore scale and bed scale two-phase instrumentation for measurement of flow regime transition, void distribution and gas-liquid interfacial area concentration in the packed bed. (3) Obtain database on flow regime transition, pressure drop, void distribution, interfacial area concentration and liquid hold up as a function of bed characteristics such as bed particle size, porosity, and liquid properties such as viscosity and surface tension. (4) Develop mathematical model for flow regime transition, void fraction distribution and interfacial area concentration for co-current gas-liquid flow through the porous bed in gravity and micro gravity conditions.(4) Develop mathematical model for the flooding phenomena in counter-current gas-liquid flow through the porous bed in gravity and micro gravity conditions. The present proposal addresses the most important topic of HEDS-specific microgravity fluid physics research identified by NASA 's one of the strategic enterprises, OBPR Enterprise. The proposed project is well defined and makes efficient use of the ground-based parabolic flight research aircraft facility. The

  15. Study of the instability of a film streaming on a vertical plane plate and submitted to a gas counter-current. Transition towards the co-current upward flow

    International Nuclear Information System (INIS)

    Bachir, Aziz

    1987-01-01

    This research thesis addresses the study of a liquid film flowing on a vertical wall in presence of a counter-current gas flow, and of its transition towards an upward co-current flow due to the increase of gas rate, such transition being herein called flooding. In the first part, the author addresses this flooding phenomenon and reports a bibliographical study of experimental and theoretical works. In the second part, he proposes an original theoretical approach to the modelling of a counter-current flow evolving towards a co-current flow: main methods of study of liquid film stability without gas flow, elaboration of the proposed model, study of the linear stability, numerical resolution, and presentation of an original theoretical criterion defining the limits of counter-current flow. The next part reports the experimental works: visualisations of mechanisms resulting in flooding in a rectangular duct, development of an experimental installation, comparison between theoretical and experimental results [fr

  16. Purification of Proteins From Cell-Culture Medium or Cell-Lysate by High-Speed Counter-Current Chromatography Using Cross-Axis Coil Planet Centrifuge

    Science.gov (United States)

    Shibusawa, Yoichi; Ito, Yoichiro

    2014-01-01

    This review describes protein purifications from cell culture medium or cell-lysate by high speed counter-current chromatography using the cross-axis coil planet centrifuge. Purifications were performed using aqueous two phase systems composed of polyethylene glycols and dextrans. PMID:25360182

  17. An investigation of the effect of some gaseous admixtures on the ionization currents in the air in the discharge chambers of the proportional counter type

    International Nuclear Information System (INIS)

    Berdowska, E.; Zastawny, A.

    1981-01-01

    Voltage-current characteristics of the ionization discharge in chambers of the proportional counter filled with air with admixtures of CO, CO 2 , CH 4 and H 2 O have been investigated. It was found that in the transition region between dependent and self-maintained discharge the characteristics change sufficiently for detection of the presence of those admixtures in the air. (author)

  18. The Behavior of Counter-Current Packed Bed in the Proximity of the Flooding Point under Periodic Variations of Inlet Velocities

    Czech Academy of Sciences Publication Activity Database

    Ondráček, Jakub; Stavárek, Petr; Jiřičný, Vladimír; Staněk, Vladimír

    2006-01-01

    Roč. 20, č. 2 (2006), s. 147-155 ISSN 0352-9568 R&D Projects: GA ČR(CZ) GA104/03/1558 Institutional research plan: CEZ:AV0Z40720504 Keywords : counter-current flow * flooding point * axial dispersion Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 0.357, year: 2006

  19. Isolation of Flavonoids From Wild Aquilaria sinensis Leaves by an Improved Preparative High-Speed Counter-Current Chromatography Apparatus.

    Science.gov (United States)

    Yang, Mao-Xun; Liang, Yao-Guang; Chen, He-Ru; Huang, Yong-Fang; Gong, Hai-Guang; Zhang, Tian-You; Ito, Yoichiro

    2018-01-01

    Four flavonoids including apigenin-7,4'-dimethylether, genkwanin, quercetin, and kaempferol were isolated in a preparative or semi-preparative scale from the leaves of wild Aquilaria sinensis using an improved preparative high-speed counter-current chromatography apparatus. The separations were performed with a two-phase solvent system composed of hexane-ethyl acetate, methanol-water at suitable volume ratios. The obtained fractions were analyzed by HPLC, and the identification of each target compound was carried out by ESI-MS and NMR. The yields of the above four target flavonoids were 4.7, 10.0, 11.0 and 4.4%, respectively. All these four flavonoids exhibited nitrite scavenging activities with the clearance rate of 12.40 ± 0.20%, 5.84 ± 0.03%, 28.10 ± 0.17% and 5.19 ± 0.11%, respectively. Quercetin was originally isolated from the Thymelaeaceae family, while kaempferol was isolated from the Aquilaria genus for the first time. In cytotoxicity test these two flavonoids exhibited moderate inhibitory activities against HepG2 cells with the IC50 values of 12.54 ± 1.37 and 38.63 ± 4.05 μM, respectively. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Two-phase flow regimes for counter-current air-water flows in narrow rectangular channels

    International Nuclear Information System (INIS)

    Kim, Byong Joo; Sohn, Byung Hu; Jeong, Si Young

    2001-01-01

    A study of counter-current two-phase flow in narrow rectangular channels has been performed. Two-phase flow regimes were experimentally investigated in a 760 mm long and 100 mm wide test section with 2.0 and 5.0 mm gap widths. The resulting flow regime maps were compared with the existing transition criteria. The experimental data and the transition criteria of the models showed relatively good agreement. However, the discrepancies between the experimental data and the model predictions of the flow regime transition became pronounced as the gap width increased. As the gap width increased the transition gas superficial velocities increased. The critical void fraction for the bubbly-to-slug transition was observed to be about 0.25. The two-phase distribution parameter for the slug flow was larger for the narrower channel. The uncertainties in the distribution parameter could lead to a disagreement in slug-to-churn transition between the experimental findings and the transition criteria. For the transition from churn to annular flow the effect of liquid superficial velocity was found to be insignificant

  1. Preparative separation of polyphenols from artichoke by polyamide column chromatography and high-speed counter-current chromatography

    International Nuclear Information System (INIS)

    Shu, Xikai; Wang, Mei; Liu, Daicheng; Wang, Daijie; Lin, Xiaojing; Liu, Jianhua; Wang, Xiao; Huang, Luqi

    2013-01-01

    An efficient method for the rapid separation and purification of polyphenols from artichoke by polyamide column chromatography in combination with high-speed counter-current chromatography (HSCCC) was successfully built. The crude ethanol extracts from dry artichoke were first pre-separated by polyamide column chromatography and divided in two parts as sample 1 and sample 2. Then, the samples were further separated by HSCCC and yielded 7.8 mg of chlorogenic acid (compound I), 24.5 mg of luteolin-7-O-β-D-rutinoside (compound II), 18.4 mg of luteolin-7-O-β-D-glucoside (compound III), and 33.4 mg of cynarin (compound IV) with purity levels of 92.0%, 98.2%, 98.5%, and 98.0%, respectively, as determined by high-performance liquid chromatography (HPLC) method. The chemical structures of these compounds were identified by electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR). (author)

  2. Preparative separation of polyphenols from artichoke by polyamide column chromatography and high-speed counter-current chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Xikai; Wang, Mei; Liu, Daicheng [College of Life Science, Shandong Normal University, Jinan, Shandong (China); Wang, Daijie; Lin, Xiaojing; Liu, Jianhua; Wang, Xiao; Huang, Luqi, E-mail: wxjn1998@126.com [Shandong Analysis and Test Center, Shandong Academy of Sciences, Jinan, Shandong (China)

    2013-09-01

    An efficient method for the rapid separation and purification of polyphenols from artichoke by polyamide column chromatography in combination with high-speed counter-current chromatography (HSCCC) was successfully built. The crude ethanol extracts from dry artichoke were first pre-separated by polyamide column chromatography and divided in two parts as sample 1 and sample 2. Then, the samples were further separated by HSCCC and yielded 7.8 mg of chlorogenic acid (compound I), 24.5 mg of luteolin-7-O-{beta}-D-rutinoside (compound II), 18.4 mg of luteolin-7-O-{beta}-D-glucoside (compound III), and 33.4 mg of cynarin (compound IV) with purity levels of 92.0%, 98.2%, 98.5%, and 98.0%, respectively, as determined by high-performance liquid chromatography (HPLC) method. The chemical structures of these compounds were identified by electrospray ionization-mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR). (author)

  3. Partitioning of actinide from simulated high level wastes arising from reprocessing of PHWR fuels: counter current extraction studies using CMPO

    International Nuclear Information System (INIS)

    Deshingkar, D.S.; Chitnis, R.R.; Wattal, P.K.; Theyyunni, T.K.; Nair, M.K.T.; Ramanujam, A.; Dhami, P.S.; Gopalakrishnan, V.; Rao, M.K.; Mathur, J.N.; Murali, M.S.; Iyer, R.H.; Badheka, L.P.; Banerji, A.

    1994-01-01

    High level wastes (HLW) arising from reprocessing of pressurised heavy water reactor (PHWR) fuels contain actinides like neptunium, americium and cerium which are not extracted in the Purex process. They also contain small quantities of uranium and plutonium in addition to fission products. Removal of these actinides prior to vitrification of HLW can effectively reduce the active surveillance period of final waste form. Counter current studies using indigenously synthesised octyl (phenyl)-N, N-diisobutylcarbamoylmethylphosphine oxide (CMPO) were taken up as a follow-up of successful runs with simulated sulphate bearing low acid HLW solutions. The simulated HLW arising from reprocessing of PHWR fuel was prepared based on presumed burnup of 6500 MWd/Te of uranium, 3 years cooling period and 800 litres of waste generation per tonne of fuel reprocessed. The alpha activity of the HLW raffinate after extraction with the CMPO-TBP mixture could be brought down to near background level. (author). 13 refs., 2 tabs., 12 figs

  4. Recovery of Butanol by Counter-Current Carbon Dioxide Fractionation with its Potential Application to Butanol Fermentation

    Directory of Open Access Journals (Sweden)

    Miriam Solana

    2016-06-01

    Full Text Available A counter-current CO2 fractionation method was applied as a mean to recover n-butanol and other compounds that are typically obtained from biobutanol fermentation broth from aqueous solutions. The influence of operating variables, such as solvent-to-feed ratio, temperature, pressure and feed solution composition was experimentally studied in terms of separation efficiency, butanol removal rate, total removal and butanol concentration in the extract at the end of the continuous cycle. With respect to the temperature and pressure conditions investigated, results show that the highest separation efficiency was obtained at 35 °C and 10.34 MPa. At these operating conditions, 92.3% of the butanol present in the feed solution was extracted, and a concentration of 787.5 g·L−1 of butanol in the extract was obtained, starting from a feed solution of 20 g·L−1. Selectivity was calculated from experimental data, concluding that our column performs much better than a single equilibrium stage. When adding ethanol and acetone to the feed solution, ethanol was detected in the water-rich fraction (raffinate, whereas the highest concentration of acetone was found in the butanol rich fraction (extract.

  5. Rational approach to solvent system selection for liquid-liquid extraction-assisted sample pretreatment in counter-current chromatography.

    Science.gov (United States)

    Wang, Jiajia; Gu, Dongyu; Wang, Miao; Guo, Xinfeng; Li, Haoquan; Dong, Yue; Guo, Hong; Wang, Yi; Fan, Mengqi; Yang, Yi

    2017-05-15

    A rational liquid-liquid extraction approach was established to pre-treat samples for high-speed counter-current chromatography (HSCCC). n-Hexane-ethyl acetate-methanol-water (4:5:4:5, v/v) and (1:5:1:5, v/v) were selected as solvent systems for liquid-liquid extraction by systematically screening K of target compounds to remove low- and high-polarity impurities in the sample, respectively. After liquid-liquid extraction was performed, 1.4g of crude sample II was obtained from 18.5g of crude sample I which was extracted from the flowers of Robinia pseudoacacia L., and then separated with HSCCC by using a solvent system composed of n-hexane-ethyl acetate-methanol-water (1:2:1:2, v/v). As a result, 31mg of robinin and 37mg of kaempferol 7-O-α-l-rhamnopyranoside were isolated from 200mg of crude sample II in a single run of HSCCC. A scale-up separation was also performed, and 160mg of robinin with 95% purity and 188mg of kaempferol 7-O-α-l-rhamnopyranoside with 97% purity were produced from 1.2g of crude sample II. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Partitioning of actinide from simulated high level wastes arising from reprocessing of PHWR fuels: counter current extraction studies using CMPO

    Energy Technology Data Exchange (ETDEWEB)

    Deshingkar, D S; Chitnis, R R; Wattal, P K; Theyyunni, T K; Nair, M K.T. [Bhabha Atomic Research Centre, Bombay (India). Process Engineering and Systems Development Div.; Ramanujam, A; Dhami, P S; Gopalakrishnan, V; Rao, M K [Bhabha Atomic Research Centre, Bombay (India). Fuel Reprocessing Group; Mathur, J N; Murali, M S; Iyer, R H [Bhabha Atomic Research Centre, Bombay (India). Radiochemistry Div.; Badheka, L P; Banerji, A [Bhabha Atomic Research Centre, Bombay (India). Bio-organic Div.

    1994-12-31

    High level wastes (HLW) arising from reprocessing of pressurised heavy water reactor (PHWR) fuels contain actinides like neptunium, americium and cerium which are not extracted in the Purex process. They also contain small quantities of uranium and plutonium in addition to fission products. Removal of these actinides prior to vitrification of HLW can effectively reduce the active surveillance period of final waste form. Counter current studies using indigenously synthesised octyl (phenyl)-N, N-diisobutylcarbamoylmethylphosphine oxide (CMPO) were taken up as a follow-up of successful runs with simulated sulphate bearing low acid HLW solutions. The simulated HLW arising from reprocessing of PHWR fuel was prepared based on presumed burnup of 6500 MWd/Te of uranium, 3 years cooling period and 800 litres of waste generation per tonne of fuel reprocessed. The alpha activity of the HLW raffinate after extraction with the CMPO-TBP mixture could be brought down to near background level. (author). 13 refs., 2 tabs., 12 figs.

  7. Chiral separation of α-cyclohexylmandelic acid enantiomers by high-speed counter-current chromatography with biphasic recognition

    Science.gov (United States)

    Tong, Shengqiang

    2010-01-01

    This work concentrates on a novel chiral separation technology named biphasic recognition applied to resolution of α-cyclohexylmandelic acid enantiomers by high-speed counter-current chromatography (HSCCC). The biphasic chiral recognition HSCCC was performed by adding lipophilic (−)-2-ethylhexyl tartrate in the organic stationary phase and hydrophilic hydroxypropyl-β-cyclodextrin in the aqueous mobile phase, which preferentially recognized the (−)-enantiomer and (+)-enantiomer, respectively. The two-phase solvent system composed of n-hexane-methyl tert-butyl ether-water (9:1:10, v/v/v) with the above chiral selectors was selected according to the partition coefficient and separation factor of the target enantiomers. Various parameters involved in the chiral separation were investigated, namely the types of the chiral selector (CS); the concentration of each chiral selector; pH of the mobile phase; and the separation temperature. The mechanism involved in this biphasic recognition chiral separation by HSCCC was discussed. Langmuirian isotherm was employed to estimate the loading limits for each chiral selector. The overall experimental results show that the HSCCC separation of enantiomer based on biphasic recognition is much more efficient than the traditional monophasic recognition chiral separation, since it utilizes the cooperation of both lipophilic and hydrophilic chiral selectors. PMID:20303497

  8. Preparative separation of capsaicin and dihydrocapsaicin from Capsicum frutescens by high-speed counter-current chromatography.

    Science.gov (United States)

    Peng, Aihua; Ye, Haoyu; Li, Xia; Chen, Lijuan

    2009-09-01

    Capsaicin and dihydrocapsaicin are two main bioactive components of Capsicum frutescens and are widely used as food additives and drugs in China and India. Due to their similarity in structures, isolation of capsaicin and dihydrocapsaicin with traditional methods such as silica gel column chromatography, normal-phase thin-layer chromatography (TLC) becomes difficult. This study involves separating capsaicin and dihydrocapsaicin with sufficient purity and recovery using high-speed counter-current chromatography (HSCCC) with a solvent system composed of n-hexane-ethyl acetate-methanol-water-acetic acid (20:20:20:20:2, v/v/v/v/v). Separation parameters such as sample volume, and sample concentration were first optimized on analytical HSCCC, and then scaled up to preparative HSCCC. 0.65 g capsaicin and 0.28 g dihydrocapsaicin were obtained from 1.2 g crude extract and their purities were 98.5 and 97.8%, respectively. The recoveries of the two compounds were 86.3 and 85.4%, respectively. The purity of the isolated compounds was analyzed by high-performance liquid chromatography (HPLC) and their structures were identified by (1)H nuclear magnetic resonance (NMR) and (13)C NMR analysis.

  9. The three-dimensional model for helical columns on type-J synchronous counter-current chromatography.

    Science.gov (United States)

    Guan, Y H; van den Heuvel, Remco

    2011-08-05

    Unlike the existing 2-D pseudo-ring model for helical columns undergoing synchronous type-J planetary motion of counter-current chromatograph (CCC), the 3-D "helix" model developed in this work shows that there is a second normal force (i.e. the binormal force) applied virtually in the axial direction of the helical column. This force alternates in the two opposite directions and intensifies phase mixing with increasing the helix angle. On the contrary, the 2-D spiral column operated on the same CCC device lacks this third-dimensional mixing force. The (principal) normal force quantified by this "helix" model has been the same as that by the pseudo-ring model. With β>0.25, this normal centrifugal force has been one-directional and fluctuates cyclically. Different to the spiral column, this "helix" model shows that the centrifugal force (i.e. the hydrostatic force) does not contribute to stationary phase retention in the helical column. Between the popular helical columns and the emerging spiral columns for type-J synchronous CCC, this work has thus illustrated that the former is associated with better phase mixing yet poor retention for the stationary phase whereas the latter has potential for better retention for the stationary phase yet poor phase mixing. The methodology developed in this work may be regarded as a new platform for designing optimised CCC columns for analytical and engineering applications. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. Multi-species counter-current diffusion model for etching depleted uranium oxide in NF3, RF glow discharge

    International Nuclear Information System (INIS)

    Saber, H.H.; El-Genk, M.S.

    1999-01-01

    Results of recent experiments investigating the decontamination of depleted UO 2 using NF 3 gas, RF gloss discharge, showed that etching rate decreased monotonically with immersion time to the end point. In addition to the formation of non-volatile reaction products on UO 2 surface, the accumulation of UF 6 in the sheath contributed to the decrease in etch rate with immersion time. To investigate the latter, a transient, multi-species, counter-current diffusion model for UO 2 etching is developed. Model results indicated that, depending on gas pressure and absorbed power, the diffusion coefficient of F in the sheath decreased at the end point by ∼15%. At 17.0 Pa and 200 W, the mole fraction of F at UO 2 surface decreased rapidly with immersion time to 61% and 86% of its initial value, after one and two characteristic etch time, respectively, it became almost zero at the end point, reached after 4--5 characteristic etch times

  11. Needle counter

    International Nuclear Information System (INIS)

    Fujita, Yuzo

    1977-01-01

    Needle counter had been devised by Geiger about 60 years ago before the present GM counter appeared. It is suitable for the detection of weak radiation because it is limited in effective volume, if the background due to mainly cosmic ray is proportional to the effective volume of the counter. Recently the very low β detector having a needle counter as the main detector has been developed. It showed highly excellent performance in the measurements of small area samples, about ten times sensitive as compared with other detectors. The counter is installed in the very low radiation measuring well at Nokogiriyama, Chiba Prefecture, using a NaI scintillator as its guard counter. D. H. Wilkinson first treated a gas amplification counter theoretically and quantitatively. The authors have obtained good results in the comparison with the experiments of the counter using a generalized form of Wilkinson theory. The findings obtained through this study seem to be applicable to the electrode arrangement which is important for the counter design. It was found that the excellent rise time of induced pulses in a gas amplification counter was achieved in larger amplification factor and smaller convolution effect. In the detection of charged particles with small obstructing capability such as γ ray, faster rise time and higher pulses can be obtained with needle counters than wire counters. (Wakatsuki, Y.)

  12. Multi-channel counter-current chromatography for high-throughput fractionation of natural products for drug discovery.

    Science.gov (United States)

    Wu, Shihua; Yang, Lu; Gao, Yuan; Liu, Xiaoyue; Liu, Feiyan

    2008-02-08

    A multi-channel counter-current chromatography (CCC) method has been designed and fabricated for the high-throughput fractionation of natural products without complications sometimes encountered with other conventional chromatographic systems, such as irreversible adsorptive constituent losses and deactivation, tailing of solute peaks and contamination. It has multiple independent CCC channels and each channel connects independent separation column(s) by parallel flow tubes, and thus the multi-channel CCC apparatus can achieve simultaneously two or more independent chromatographic processes. Furthermore, a high-throughput CCC fractionation method for natural products has been developed by a combination of a new three-channel CCC apparatus and conventional parallel chromatographic devices including pumps, sample injectors, effluent detectors and collectors, and its performance has been displayed on the fractionation of ethyl acetate extracts of three natural materials Solidago canadensis, Suillus placidus, and Trichosanthes kirilowii, which are found to be potent cytotoxic to tumor cell lines in the course of screening the antitumor candidates. By combination of biological screening programs and preparative high-performance liquid chromatography (HPLC) purification, 22.8 mg 6 beta-angeloyloxykolavenic acid and 29.4 mg 6 beta-tigloyloxykolavenic acid for S. canadensis, 25.3mg suillin for S. placidus, and 6.8 mg 23,24-dihydrocucurbitacin B for T. Kirilowii as their major cytotoxic principles were isolated from each 1000 mg crude ethyl acetate extract. Their chemical structures were characterized by electrospray ionization mass spectrometry, one- and two-dimensional nuclear magnetic resonance. The overall results indicate the multi-channel CCC is very useful for high-throughput fractionation of natural products for drug discovery in spite of the solvent balancing requirement and the lower resolution of the shorter CCC columns.

  13. Prevention and Control Strategies to Counter Zika Virus, a Special Focus on Intervention Approaches against Vector Mosquitoes—Current Updates

    Directory of Open Access Journals (Sweden)

    Raj K. Singh

    2018-02-01

    Full Text Available Zika virus (ZIKV is the most recent intruder that acquired the status of global threat creating panic and frightening situation to public owing to its rapid spread, attaining higher virulence and causing complex clinical manifestations including microcephaly in newborns and Guillain Barré Syndrome. Alike other flaviviruses, the principal mode of ZIKV transmission is by mosquitoes. Advances in research have provided reliable diagnostics for detecting ZIKV infection, while several drug/therapeutic targets and vaccine candidates have been identified recently. Despite these progresses, currently there is neither any effective drug nor any vaccine available against ZIKV. Under such circumstances and to tackle the problem at large, control measures of which mosquito population control need to be strengthened following appropriate mechanical, chemical, biological and genetic control measures. Apart from this, several other known modes of ZIKV transmission which have gained importance in recent past such as intrauterine, sexual intercourse, and blood-borne spread need to be checked and kept under control by adopting appropriate precautions and utmost care during sexual intercourse, blood transfusion and organ transplantation. The virus inactivation by pasteurization, detergents, chemicals, and filtration can effectively reduce viral load in plasma-derived medicinal products. Added to this, strengthening of the surveillance and monitoring of ZIKV as well as avoiding travel to Zika infected areas would aid in keeping viral infection under check. Here, we discuss the salient advances in the prevention and control strategies to combat ZIKV with a focus on highlighting various intervention approaches against the vector mosquitoes of this viral pathogen along with presenting an overview regarding human intervention measures to counter other modes of ZIKV transmission and spread. Additionally, owing to the success of vaccines for a number of infections

  14. High-speed counter-current chromatography in separation of betacyanins from flowers of red Gomphrena globosa L. cultivars.

    Science.gov (United States)

    Spórna-Kucab, Aneta; Hołda, Ewelina; Wybraniec, Sławomir

    2016-10-15

    Antioxidant and possible chemopreventive properties of betacyanins, natural plant pigments, contribute to a growing interest in their chemistry and separation. Mixtures of betacyanins from fresh red Gomphrena globosa L. cultivar flowers were separated in three highly polar solvent systems by high-speed counter-current chromatography (HSCCC) for a direct comparison of their separation effectiveness. Three samples of crude extract (600mg) were run on semi-preparative scale in solvent system (NH4)2SO4soln - EtOH (2.0:1.0, v/v) (system I) and the modified systems: EtOH - ACN - 1-PrOH - (NH4)2SO4satd.soln - H2O (0.5:0.5:0.5:1.2:1.0, v/v/v/v/v) (system II) and EtOH - ACN - (NH4)2SO4satd.soln - H2O (1.0:0.5:1.2:1.0, v/v/v/v) (system III). The systems were used in the head-to-tail (system I) or tail-to-head (systems II and III) mode. The flow rate of the mobile phase was 2.0ml/min and the column rotation speed was 860rpm. The retention of the stationary phase was 52.0% (system I), 80.2% (systems II) and 82.0% (system III). The betacyanins in the crude extract as well as HSCCC fractions were analyzed by LC-MS/MS. System I was applied for the first time in HSCCC for the separation of betacyanins and was quite effective in separation of amaranthine and 17-decarboxy-amaranthine (αI=1.19) and very effective for 17-decarboxy-amaranthine and betanin (αI=2.20). Modification of system I with acetonitrile (system III) as well as acetonitrile and propanol (system II) increased their separation effectiveness. Systems II-III enable complete separation of 17-decarboxy-amaranthine (KD(II)=2.94,KD(III)=2.42) and betanin (KD(II)=2.46,KD(III)=1.10) as well as betanin and gomphrenin I (KD(II)=1.62, KD(III)=0.74). In addition, separation of amaranthine and 17-decarboxy-amaranthine is the most effective in system II, therefore, this system proved to be the most suitable for the separation of all polar betacyanins. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Versatile solvent systems for the separation of betalains from processed Beta vulgaris L. juice using counter-current chromatography.

    Science.gov (United States)

    Spórna-Kucab, Aneta; Ignatova, Svetlana; Garrard, Ian; Wybraniec, Sławomir

    2013-12-15

    Two mixtures of decarboxylated and dehydrogenated betacyanins from processed red beet roots (Beta vulgaris L.) juice were fractionated by high performance counter-current chromatography (HPCCC) producing a range of isolated components. Mixture 1 contained mainly betacyanins, 14,15-dehydro-betanin (neobetanin) and their decarboxylated derivatives while mixture 2 consisted of decarboxy- and dehydro-betacyanins. The products of mixture 1 arose during thermal degradation of betanin/isobetanin in mild conditions while the dehydro-betacyanins of mixture 2 appeared after longer heating of the juice from B. vulgaris L. Two solvent systems were found to be effective for the HPCCC. A highly polar, high salt concentration system of 1-PrOH-ACN-(NH4)2SO4 (satd. soln)-water (v/v/v/v, 1:0.5:1.2:1) (tail-to-head mode) enabled the purification of 2-decarboxy-betanin/-isobetanin, 2,17-bidecarboxy-betanin/-isobetanin and neobetanin (all from mixture 1) plus 17-decarboxy-neobetanin, 2,15,17-tridecarboxy-2,3-dehydro-neobetanin, 2-decarboxy-neobetanin and 2,15,17-tridecarboxy-neobetanin (from mixture 2). The other solvent system included heptafluorobutyric acid (HFBA) as ion-pair reagent and consisted of tert-butyl methyl ether (TBME)-1-BuOH-ACN-water (acidified with 0.7% HFBA) (2:2:1:5, v/v/v/v) (head-to-tail mode). This system enabled the HPCCC purification of 2,17-bidecarboxy-betanin/-isobetanin and neobetanin (from mixture 1) plus 2,15,17-tridecarboxy-2,3-dehydro-neobetanin, 2,17-bidecarboxy-2,3-dehydro-neobetanin and 2,15,17-tridecarboxy-neobetanin (mixture 2). The results of this research are crucial in finding effective isolation methods of betacyanins and their derivatives which are meaningful compounds due their colorant properties and potential health benefits regarding antioxidant and cancer prevention. The pigments were detected by LC-DAD and LC-MS/MS techniques. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Quenching of hot wall of vertical-narrow-annular passages by water falling down counter-currently

    International Nuclear Information System (INIS)

    Koizumi, Yasuo; Ohtake, Hiroyasu; Arai, Manabu; Okabayashi, Yoshiaki; Nagae, Takashi; Okano, Yukimitsu

    2004-01-01

    quenching of a thin-gap annular flow passage by gravitational liquid penetration was examined by using water. The outer wall of the test flow channel was made of stainless steel. The inner wall was made of glass or stainless steel. The annular gap spacings tested were 10, 5.0, 2.0, 1.0 and 0.5 mm. No inner wall case; the gap width = ∞, was also tested. The stainless steel walls(s) was (were) heated electrically. When the glass wall was used for the inner wall, a fiber scope was inserted inside to observe a flow state. The quenching was observed for the gap spacing over 1.0 mm. When the spacing was less than 1.0 mm, the wall was gradually and monotonously cooled down without any quenching. As the gap spacing became narrow, the counter-current flow limiting; flooding, severely occurred. The peak heat flux during the quenching process became lower than that in pool boiling as the gap spacing became narrower. The quenching propagated from the bottom when the gap spacing was larger than 5 mm. When the gap clearance was less than 2.0 mm, the quenching proceeded from the top in the bottom closed case. It was visually observed that liquid accumulated in the lower portion of the flow passage in the 5 mm gap case and the rewetting front propagated upward from the bottom. In the 1.0 mm gap case, the moving-down of the rewetting front was observed. The quenching velocity became slow as the gap spacing became narrow. Quenching simulation was performed by solving a transient heat conduction equation. The simulation indicated that the quenching velocity becomes fast as the peak heat flux becomes low with the gap spacing, which was opposite to the experimental results. It was also suggested that precursory cooling is one of key factors to control the rewetting velocity; as the precursory cooling becomes weak, the rewetting velocity becomes slow. (author)

  17. Separation of phenolic acids from sugarcane rind by online solid-phase extraction with high-speed counter-current chromatography.

    Science.gov (United States)

    Geng, Ping; Fang, Yingtong; Xie, Ronglong; Hu, Weilun; Xi, Xingjun; Chu, Qiao; Dong, Genlai; Shaheen, Nusrat; Wei, Yun

    2017-02-01

    Sugarcane rind contains some functional phenolic acids. The separation of these compounds from sugarcane rind is able to realize the integrated utilization of the crop and reduce environment pollution. In this paper, a novel protocol based on interfacing online solid-phase extraction with high-speed counter-current chromatography (HSCCC) was established, aiming at improving and simplifying the process of phenolic acids separation from sugarcane rind. The conditions of online solid-phase extraction with HSCCC involving solvent system, flow rate of mobile phase as well as saturated extent of absorption of solid-phase extraction were optimized to improve extraction efficiency and reduce separation time. The separation of phenolic acids was performed with a two-phase solvent system composed of butanol/acetic acid/water at a volume ratio of 4:1:5, and the developed online solid-phase extraction with HSCCC method was validated and successfully applied for sugarcane rind, and three phenolic acids including 6.73 mg of gallic acid, 10.85 mg of p-coumaric acid, and 2.78 mg of ferulic acid with purities of 60.2, 95.4, and 84%, respectively, were obtained from 150 mg sugarcane rind crude extracts. In addition, the three different elution methods of phenolic acids purification including HSCCC, elution-extrusion counter-current chromatography and back-extrusion counter-current chromatography were compared. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A mixture theory approach to model co- and counter-current two-phase flow in porous media accounting for viscous coupling

    Science.gov (United States)

    Qiao, Y.; Andersen, P. Ø.; Evje, S.; Standnes, D. C.

    2018-02-01

    It is well known that relative permeabilities can depend on the flow configuration and they are commonly lower during counter-current flow as compared to co-current flow. Conventional models must deal with this by manually changing the relative permeability curves depending on the observed flow regime. In this paper we use a novel two-phase momentum-equation-approach based on general mixture theory to generate effective relative permeabilities where this dependence (and others) is automatically captured. In particular, this formulation includes two viscous coupling effects: (i) Viscous drag between the flowing phases and the stagnant porous rock; (ii) viscous drag caused by momentum transfer between the flowing phases. The resulting generalized model will predict that during co-current flow the faster moving fluid accelerates the slow fluid, but is itself decelerated, while for counter-current flow they are both decelerated. The implications of these mechanisms are demonstrated by investigating recovery of oil from a matrix block surrounded by water due to a combination of gravity drainage and spontaneous imbibition, a situation highly relevant for naturally fractured reservoirs. We implement relative permeability data obtained experimentally through co-current flooding experiments and then explore the model behavior for different flow cases ranging from counter-current dominated to co-current dominated. In particular, it is demonstrated how the proposed model seems to offer some possible interesting improvements over conventional modeling by providing generalized mobility functions that automatically are able to capture more correctly different flow regimes for one and the same parameter set.

  19. Isolamento do alcalóide ricinina das folhas de Ricinus communis (Euphorbiaceae através de cromatografias em contracorrente Isolation of the alkaloid ricinine from the leaves of Ricinus communis (Euphorbiaceae through counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Ana Cristina Leite

    2005-12-01

    Full Text Available Droplet counter-current chromatography, rotation locular counter-current chromatography and high-speed counter-current chromatography were applied to the preparative separation of the alkaloid ricinine from the dichloromethane extracts of Ricinus communis leaves. The solvent system used was composed of dichloromethane-methanol-water (93:35:72 v/v/v and all techniques led to the isolation of large amounts of the alkaloid. The best result was obtained through HSCCC, since the ricinine yield was respectively 50% and 30% higher than when using RLCCC or DCCC.

  20. Experimental characterisation of the interfacial structure during counter-current flow limitation in a model of the hot leg of a PWR

    Energy Technology Data Exchange (ETDEWEB)

    Vallee, C., E-mail: c.vallee@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Inst. of Safety Research, Dresden (Germany); Nariai, T.; Futatsugi, T.; Tomiyama, A., E-mail: nariai@cfrg.scitec.kobe-u.ac.jp, E-mail: futatsugi@cfrg.scitec.kobe-u.ac.jp, E-mail: tomiyama@mech.kobe-u.ac.jp [Kobe Univ., Graduate School of Engineering, Kobe (Japan); Lucas, D., E-mail: d.lucas@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Inst. of Safety Research, Dresden (Germany); Murase, M., E-mail: murase@inss.co.jp [Inst. of Nuclear Safety System, Inc. (INSS), Fukui (Japan)

    2011-07-01

    In order to investigate the two-phase flow behaviour during counter-current flow limitation in the hot leg of a pressurised water reactor, dedicated experiments were performed in a scaled down model of Kobe University. The structure of the interface was observed from the side of the channel test section using a high-speed video camera. An algorithm was developed to recognise the stratified interface in the camera frames after background subtraction. The evolution of the water level along the hot leg is analysed in function of the liquid and gas flow rates. (author)

  1. Preparative Separation of Sulfur-Containing Diketopiperazines from Marine Fungus Cladosporium sp. Using High-Speed Counter-Current Chromatography in Stepwise Elution Mode

    OpenAIRE

    Gu, Binbin; Zhang, Yanying; Ding, Lijian; He, Shan; Wu, Bin; Dong, Junde; Zhu, Peng; Chen, Juanjuan; Zhang, Jinrong; Yan, Xiaojun

    2015-01-01

    High-speed counter-current chromatography (HSCCC) was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs) (including two new compounds cladosporin A (1) and cladosporin B (3), and a known compound haematocin (2)) from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v) and (2:1:2:1, v/v), in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was perfor...

  2. Separation and purification of four flavonol diglucosides from the flower of Meconopsis integrifolia by high-speed counter-current chromatography.

    Science.gov (United States)

    Huang, Yanfei; Han, Yatao; Chen, Keli; Huang, Bisheng; Liu, Yuan

    2015-12-01

    Flavonoids are the main components of Meconopsis integrifolia (Maxim.) Franch, which is a traditional Tibetan medicine. However, traditional chromatography separation requires a large quantity of raw M. integrifolia and is very time consuming. Herein, we applied high-speed counter-current chromatography in the separation and purification of flavonoids from the ethanol extracts of M. integrifolia flower. Ethyl acetate/n-butanol/water (2:3:5, v/v/v) was selected as the optimum solvent system to purify the four components, namely quercetin-3-O-β-d-glucopyrannosy-(1→6)-β-d-glucopyranoside (compound 1, 60 mg), quercetin 3-O-[2'''-O-acetyl-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside (compound 2, 40 mg), quercetin 3-O-[3'''-O-acetyl-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside (compound 3, 11 mg), and quercetin 3-O-[6'''-O-acetyl-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside (compound 4, 16 mg). Among the four compounds, 3 and 4 were new acetylated flavonol diglucosides. After the high-speed counter-current chromatography separation, the purities of the four flavonol diglucosides were 98, 95, 90, and 92%, respectively. The structures of these compounds were identified by mass spectrometry and NMR spectroscopy. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Numerical simulations of counter-current two-phase flow experiments in a PWR hot leg model using an interfacial area density model

    Energy Technology Data Exchange (ETDEWEB)

    Hoehne, Thomas, E-mail: t.hoehne@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany); Deendarlianto,; Lucas, Dirk [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Safety Research, P.O. Box 510 119, D-01314 Dresden (Germany)

    2011-10-15

    In order to improve the understanding of counter-current two-phase flows and to validate new physical models, CFD simulations of 1/3rd scale model of the hot leg of a German Konvoi PWR with rectangular cross section was performed. Selected counter-current flow limitation (CCFL) experiments at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) were calculated with ANSYS CFX 12.1 using the multi-fluid Euler-Euler modeling approach. The transient calculations were carried out using a gas/liquid inhomogeneous multiphase flow model coupled with a k-{omega} turbulence model for each phase. In the simulation, the surface drag was approached by a new correlation inside the Algebraic Interfacial Area Density (AIAD) model. The AIAD model allows the detection of the morphological form of the two phase flow and the corresponding switching via a blending function of each correlation from one object pair to another. As a result this model can distinguish between bubbles, droplets and the free surface using the local liquid phase volume fraction value. A comparison with the high-speed video observations shows a good qualitative agreement. The results indicated that quantitative agreement of the CCFL characteristics between calculation and experimental data was obtained. The goal is to provide an easy usable AIAD framework for all Code users, with the possibility of the implementation of their own correlations.

  4. Numerical simulations of counter-current two-phase flow experiments in a PWR hot leg model using an interfacial area density model

    Energy Technology Data Exchange (ETDEWEB)

    Hohne, T.; Deendarlianto; Vallee, C.; Lucas, D.; Beyer, M., E-mail: t.hoehne@hzdr.de [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Inst. of Safety Research, Dresden (Germany)

    2011-07-01

    In order to improve the understanding of counter-current two-phase flows and to validate new physical models, CFD simulations of 1/3rd scale model of the hot leg of a German Konvoi PWR with rectangular cross section was performed. Selected counter-current flow limitation (CCFL) experiments at the Helmholtz-Zentrum Dresden- Rossendorf (HZDR) were calculated with ANSYS CFX 12.1 using the multi-fluid Euler-Euler modeling approach. The transient calculations were carried out using a gas/liquid inhomogeneous multiphase flow model coupled with a SST turbulence model for each phase. In the simulation, the surface drag was approached by a new correlation inside the Algebraic Interfacial Area Density (AIAD) model. The AIAD model allows the detection of the morphological form of the two phase flow and the corresponding switching via a blending function of each correlation from one object pair to another. As a result this model can distinguish between bubbles, droplets and the free surface using the local liquid phase volume fraction value. A comparison with the high-speed video observations shows a good qualitative agreement. The results indicated that quantitative agreement of the CCFL characteristics between calculation and experimental data was obtained. The goal is to provide an easy usable AIAD framework for all ANSYS CFX users, with the possibility of the implementation of their own correlations. (author)

  5. Two-phase flow experiments on Counter-Current Flow Limitation in a model of the hot leg of a pressurized water reactor (2015 test series)

    International Nuclear Information System (INIS)

    Beyer, Matthias; Lucas, Dirk; Pietruske, Heiko; Szalinski, Lutz

    2016-12-01

    Counter-Current Flow Limitation (CCFL) is of importance for PWR safety analyses in several accident scenarios connected with loss of coolant. Basing on the experiences obtained during a first series of hot leg tests now new experiments on counter-current flow limitation were conducted in the TOPFLOW pressure vessel. The test series comprises air-water tests at 1 and 2 bar as well as steam-water tests at 10, 25 and 50 bar. During the experiments the flow structure was observed along the hot leg model using a high-speed camera and web-cams. In addition pressure was measured at several positions along the horizontal part and the water levels in the reactor-simulator and steam-generator-simulator tanks were determined. This report documents the experimental setup including the description of operational and special measuring techniques, the experimental procedure and the data obtained. From these data flooding curves were obtained basing on the Wallis parameter. The results show a slight shift of the curves in dependency of the pressure. In addition a slight decrease of the slope was found with increasing pressure. Additional investigations concern the effects of hysteresis and the frequencies of liquid slugs. The latter ones show a dependency on pressure and the mass flow rate of the injected water. The data are available for CFD-model development and validation.

  6. Two-phase flow experiments on Counter-Current Flow Limitation in a model of the hot leg of a pressurized water reactor (2015 test series)

    Energy Technology Data Exchange (ETDEWEB)

    Beyer, Matthias; Lucas, Dirk; Pietruske, Heiko; Szalinski, Lutz

    2016-12-15

    Counter-Current Flow Limitation (CCFL) is of importance for PWR safety analyses in several accident scenarios connected with loss of coolant. Basing on the experiences obtained during a first series of hot leg tests now new experiments on counter-current flow limitation were conducted in the TOPFLOW pressure vessel. The test series comprises air-water tests at 1 and 2 bar as well as steam-water tests at 10, 25 and 50 bar. During the experiments the flow structure was observed along the hot leg model using a high-speed camera and web-cams. In addition pressure was measured at several positions along the horizontal part and the water levels in the reactor-simulator and steam-generator-simulator tanks were determined. This report documents the experimental setup including the description of operational and special measuring techniques, the experimental procedure and the data obtained. From these data flooding curves were obtained basing on the Wallis parameter. The results show a slight shift of the curves in dependency of the pressure. In addition a slight decrease of the slope was found with increasing pressure. Additional investigations concern the effects of hysteresis and the frequencies of liquid slugs. The latter ones show a dependency on pressure and the mass flow rate of the injected water. The data are available for CFD-model development and validation.

  7. Preparative separation and purification of bufadienolides from ChanSu by high-speed counter-current chromatography combined with preparative HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jialian; Zhang, Yongqing, E-mail: fleiv@163.com [College of Pharmacy, Shandong University of Traditional Chinese Medicine, Jinan, Shandong (China); Lin, Yunliang; Wang, Xiao; Fang, Lei; Geng, Yanling [Shandong Analysis and Test Center, Shandong Academy of Sciences, Jinan, Shandong (China); Zhang, Qinde [Shandong College of Traditional Chinese Medicine, Laiyang, Shandong (China)

    2013-09-01

    Eight bufadienolides were successfully isolated and purified from ChanSu by high-speed counter-current chromatography (HSCCC) combined with preparative HPLC (prep-HPLC). First, a stepwise elution mode of HSCCC with the solvent system composed of petroleum ether-ethyl acetate-methanol-water (4:6:4:6, 4:6:5:5, v/v) was employed and four bufadienolides, two partially purified fractions were obtained from 200 mg of crude extract. The partially purified fractions III and VI were then further separated by prepHPLC, respectively, and another four bufadienolides were recovered. Their structures were confirmed by ESI-MS and {sup 1}H-NMR spectra. (author)

  8. Preparative separation of C{sub 19}-diterpenoid alkaloids from Aconitum carmichaelii Debx by pH zone-refining counter-current chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dahui [Institute of Medicinal Plants, Yunnan Academy of Agricultural Sciences, Kunming (China); Shu, Xikai; Wang, Xiao; Fang, Lei; Huang, Luqi, E-mail: wxjn1998@126.com [Shandong Analysis and Test Center, Shandong Academy of Sciences, Jinan, Shandong (China); Xi, Xingjun; Zheng, Zhenjia [China National institute of Standardization, Beijing (China)

    2013-11-01

    The technique of pH-zone-refining counter-current chromatography was successfully applied to preparatively separate three C{sub 19}-diterpenoid alkaloids from the crude extracts of Aconitum carmichaelii for the first time using a two-phase solvent system of petroleum ether-ethyl acetate-methanol-water (5:5:1:9, v/v/v/v). Mesaconitine (I), hypaconitine (II), and deoxyaconitine (III) were obtained from 2.5 g of the crude alkaloids in a one-step separation; the yields were 4.16%, 16.96%, and 5.05%, respectively. The purities of compounds I, II, and III were 93.0%, 95%, and 96%, respectively, as determined by HPLC. The chemical structures of the three compounds were identified by electrospray ionization mass spectrometry (ESI-MS) and NMR. (author)

  9. Extraction and isolation of dictamnine, obacunone and fraxinellone from Dictamnus dasycarpus Turcz. by supercritical fluid extraction and high-speed counter-current chromatography

    International Nuclear Information System (INIS)

    Wang, Daijie; Lin, Yunliang; Lin, Xiaojing; Geng, Yanling; Wang, Xiao; Zhang, Jinjie; Qiu, Jiying

    2012-01-01

    Supercritical fluid extraction was used to extract active compounds from the Chinese traditional medicinal D. dasycarpus under the pressure of 30 MPa and temperature of 45 degree C. Further separation and purification was established by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.8:1.3:0.9, volume ratio). The separation yielded a total of 47 mg of dictamnine, 24 mg of obacunone and 83 mg of fraxinellone from 1.0 g of the crude extract in one step separation with the purity of 99.2, 98.4 and 99.0%, respectively, as determined by HPLC. The chemical structures of these compounds were identified by ESI-MS, IR, 1H-NMR and 13 C-NMR. (author)

  10. Preparative separation of C19-diterpenoid alkaloids from Aconitum carmichaelii Debx by pH‑zone-refining counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Dahui Liu

    2013-01-01

    Full Text Available The technique of pH-zone-refining counter-current chromatography was successfully applied to preparatively separate three C19-diterpenoid alkaloids from the crude extracts of Aconitum carmichaelii for the first time using a two-phase solvent system of petroleum ether-ethyl acetate-methanol-water (5:5:1:9, v/v/v/v. Mesaconitine (I, hypaconitine (II, and deoxyaconitine (III were obtained from 2.5 g of the crude alkaloids in a one-step separation; the yields were 4.16%, 16.96%, and 5.05%, respectively. The purities of compounds I, II, and III were 93.0%, 95%, and 96%, respectively, as determined by HPLC. The chemical structures of the three compounds were identified by electrospray ionization mass spectrometry (ESI-MS and NMR.

  11. Aeroallergen analyses and their clinical relevance. I. Immunochemical quantification of allergens by RAST-inhibition, Mab-ELISA, basophil histamine release, and counter current immuno electrophoresis

    DEFF Research Database (Denmark)

    Johnsen, C R; Abrahamsen, L; Stahl Skov, P

    1991-01-01

    The aim was to compare IgE and IgG4 RAST-inhibition assay (RI), monoclonal antibody ELISA (Mab-ELISA), counter current immuno electrophoresis (CCIE) and histamine release from basophil leukocytes (HR) for allergen quantification with special reference to aeroallergen detection. As components......-U/ml) than IgE-RI (2*10(3) SQ-U/ml). The ranges of allergen detection limits for the Mab-ELISA were equal for cat and Derm. pter. (10-10(2) SQ-U/ml). The range of allergen detection limits for CCIE, assaying dog were 10(4)-10(5) SQ-U/ml. The ranges of allergen detection limits for HR were equal for cat...

  12. Preparative separation and purification of bufadienolides from ChanSu by high-speed counter-current chromatography combined with preparative HPLC

    International Nuclear Information System (INIS)

    Li, Jialian; Zhang, Yongqing; Lin, Yunliang; Wang, Xiao; Fang, Lei; Geng, Yanling; Zhang, Qinde

    2013-01-01

    Eight bufadienolides were successfully isolated and purified from ChanSu by high-speed counter-current chromatography (HSCCC) combined with preparative HPLC (prep-HPLC). First, a stepwise elution mode of HSCCC with the solvent system composed of petroleum ether–ethyl acetate–methanol–water (4:6:4:6, 4:6:5:5, v/v) was employed and four bufadienolides, two partially purified fractions were obtained from 200 mg of crude extract. The partially purified fractions III and VI were then further separated by prepHPLC, respectively, and another four bufadienolides were recovered. Their structures were confirmed by ESI-MS and 1 H-NMR spectra. (author)

  13. Separation of Np from U and Pu using a salt-free reductant for Np(VI) by continuous counter-current back-extraction

    International Nuclear Information System (INIS)

    Ban, Yasutoshi; Asakura, Toshihide; Morita, Yasuji

    2005-01-01

    Reduction properties of several salt-free reagents for Np(VI) and Pu(IV) were reviewed to choose selective reductants that reduce only Np(VI) to Np(V) for separating Np from U and Pu in TBP by reductive back-extraction. Allylhydrazine was proposed as a candidate for selective Np(VI) reductant, and it was confirmed by a batch experiment that allylhydrazine reduced almost all Np(VI) to Np(V) and back-extracted Np from organic phase (30 vol.% TBP diluted in n-dodecane) to aqueous phase (3 mol/dm 3 HNO 3 ) within 10 min. A continuous counter-current experiment using a miniature mixer-settler was carried out with allylhydrazine at room temperature. At least 91% of Np(VI) that fed to the mixer-settler was selectively reduced to Np(V) and separated from U and Pu. (author)

  14. Extraction and isolation of dictamnine, obacunone and fraxinellone from Dictamnus dasycarpus Turcz. by supercritical fluid extraction and high-speed counter-current chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Daijie; Lin, Yunliang; Lin, Xiaojing; Geng, Yanling; Wang, Xiao, E-mail: wxjn1998@126.com [Process Control Research Center of TCM. Shandong Academy of Sciences. Shandong Analysis and Test Center (China); Zhang, Jinjie [College of Biosystems Engineering and Food Science, Zhejiang University (China); Qiu, Jiying [Institute of Agro-Food Science and Technology, Shandong Academy of Agricultural Science, Shandong (China)

    2012-07-01

    Supercritical fluid extraction was used to extract active compounds from the Chinese traditional medicinal D. dasycarpus under the pressure of 30 MPa and temperature of 45 degree C. Further separation and purification was established by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.8:1.3:0.9, volume ratio). The separation yielded a total of 47 mg of dictamnine, 24 mg of obacunone and 83 mg of fraxinellone from 1.0 g of the crude extract in one step separation with the purity of 99.2, 98.4 and 99.0%, respectively, as determined by HPLC. The chemical structures of these compounds were identified by ESI-MS, IR, 1H-NMR and {sup 13}C-NMR. (author)

  15. Extraction and isolation of dictamnine, obacunone and fraxinellone from Dictamnus dasycarpus Turcz. by supercritical fluid extraction and high-speed counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Daijie Wang

    2012-01-01

    Full Text Available Supercritical fluid extraction was used to extract active compounds from the Chinese traditional medicinal D. dasycarpus under the pressure of 30 MPa and temperature of 45 ºC. Further separation and purification was established by high-speed counter-current chromatography (HSCCC with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (1:0.8:1.3:0.9, volume ratio. The separation yielded a total of 47 mg of dictamnine, 24 mg of obacunone and 83 mg of fraxinellone from 1.0 g of the crude extract in one step separation with the purity of 99.2, 98.4 and 99.0%, respectively, as determined by HPLC. The chemical structures of these compounds were identified by ESI-MS, IR, ¹H-NMR and 13C-NMR.

  16. Counter radicalization development assistance

    OpenAIRE

    van Hippel, Karin

    2006-01-01

    The paper reviews current research and practice and recommends strategies for development agencies working in the Arab and Muslim world. It builds on the basic assumption that the realization of the Millennium Development Goals will be vital to reduce support for terrorism in the long term. Within this overall framework, emphasis is placed on particular programs that could be specifically applied to counter radicalization.

  17. Body counter

    International Nuclear Information System (INIS)

    Koeppe, P.

    1975-01-01

    The paper gives a survey on some applications of the whole body counter in clinical practice and a critical study of its application as a routine testing method. Remarks on the necessary precautions are followed by a more detailed discussion of the determination of the natural potassium content, the iron metabolism, the vitamin B12 test, investigations of the metabolism of the bone using 47 Ca and 85 Sr, investigations with iodine and iodine-labelled substances, clearance investigations (in particular the 51 Cr EDTA clearance test), as well as the possibilities of neutron activation in vivo. (ORU/AK) [de

  18. Counter-current motion in counter-current chromatography.

    Science.gov (United States)

    Ito, Yoichiro

    2014-12-12

    After the CCC2012 meeting, I have received an e-mail regarding the terminology of "Countercurrent Chromatography". It stated that the term "Countercurrent" is a misnomer, because its stationary phase is motionless in the column and that the method should be renamed as liquid-liquid separations or centrifugal separations. However, it was found that these names are already used for various other techniques as found via Google search. The term "Countercurrent Chromatography" was originally made after two preparative methods of Countercurrent distribution and liquid Chromatography, both having no countercurrent motion in the column. However, it is surprising to find that this F1 hybrid method "Countercurrent Chromatography" can clearly exhibit countercurrent motion within the separation column in both hydrodynamic and hydrostatic equilibrium systems. This justifies that "Countercurrent Chromatography" is a proper term for this chromatographic method. Published by Elsevier B.V.

  19. Experimental Characterisation of the Interfacial Structure during Counter-Current Flow Limitation in a Model of the Hot Leg of a PWR

    Directory of Open Access Journals (Sweden)

    Christophe Vallée

    2012-01-01

    Full Text Available In order to investigate the two-phase flow behaviour during counter-current flow limitation in the hot leg of a pressurised water reactor, dedicated experiments were performed in a scaled down model of Kobe University. The experiments were performed with air and water at atmospheric pressure and room temperature. At high flow rates, CCFL occurs and the discharge of water to the reactor pressure vessel simulator is limited by the formation of slugs carrying liquid back to the steam generator. The structure of the interface was observed from the side of the channel test section using a high-speed video camera. An algorithm was developed to recognise the stratified interface in the camera frames after background subtraction. This method allows extracting the water level at any position in the image as well as performing further statistical treatments. The evolution of the interfacial structure along the horizontal part of the hot leg is shown by the visualisation of the probability distribution of the water level and analysed in function of the liquid and gas flow rates. The data achieved are useful for the analysis of the flow conditions as well as for the validation of modelling approaches like computational fluid dynamics.

  20. Efficient Preparation of Streptochlorin from Marine Streptomyces sp. SYYLWHS-1-4 by Combination of Response Surface Methodology and High-Speed Counter-Current Chromatography.

    Science.gov (United States)

    Li, Lin; He, Shan; Ding, Lijian; Yuan, Ye; Zhu, Peng; Epstein, Slava; Fan, Jianzhong; Wu, Xiaokai; Yan, Xiaojun

    2016-05-27

    Since first isolated from the lipophilic extract of Streptomyces sp. SF2583, streptochlorin, has attracted a lot of attention because of its various pharmacological properties, such as antibiotic, antiallergic, antitumor, and anti-inflammatory activities. For the efficient preparation of streptochlorin from a producing strain Streptomyces sp. SYYLWHS-1-4, we developed a combinative method by using response surface methodology (RSM) and high-speed counter-current chromatography (HSCCC). In the fermentation process, we used RSM to optimize the condition for the efficient accumulation of streptochlorin, and the optimal parameters were: yeast extract 1.889 g/L, soluble starch 8.636 g/L, K₂HPO₄ 0.359 g/L, CaCl₂ 2.5 g/L, MgSO₄ 0.625 g/L, marine salt 25 g/L, medium volume 50%, initial pH value 7.0, temperature 27.5 °C, which enhanced streptochlorin yield by 17.7-fold. During the purification process, the preparative HSCCC separation was performed using a petroleum ether-ethyl acetate-methanol-water (9:0.8:5:5, v/v/v/v) biphasic solvent system, where 300 mg of crude sample yielded 16.5 mg streptochlorin with over 95% purity as determined by UPLC. Consequently, the combination method provided a feasible strategy for highly effective preparation of streptochlorin, which ensured the supply of large amounts of streptochlorin for in vivo pharmacological assessments or other requirements.

  1. Separation and preparation of xanthochymol and guttiferone E by high performance liquid chromatography and high speed counter-current chromatography combined with silver nitrate coordination reaction.

    Science.gov (United States)

    Li, Jun; Gao, Ruixi; Zhao, Dan; Huang, Xianju; Chen, Yu; Gan, Fei; Liu, Hui; Yang, Guangzhong

    2017-08-18

    Xanthochymol (XCM) and guttiferone E (GFE), a pair of π bond benzophenone isomers from Garcinia xanthochymus, were once reported to be difficult or impossible to separate. The present study reports the successful separation of these two isomers through high performance liquid chromatography (HPLC), as well as their effective isolation using high speed counter-current chromatography (HSCCC) based on the silver nitrate (AgNO 3 ) coordination reaction. First, an effective HPLC separation system was developed, achieving a successful baseline separation with resolution of 2.0. Based on the partition coefficient (K) resolved by HPLC, the two-phase solvent system was determined as n-hexane, methanol and water with the uncommon volume ratio of 4:6:1. A crude extract of Garcinia xanthochymus (0.2g) was purified by normal HSCCC and refined with AgNO 3 -HSCCC. Monomers of XCM and GFE were identified by HPLC, mass spectrometry (MS) and nuclear magnetic resonance (NMR). The results demonstrate the separation and isolation of π bond benzophenone isomers using ordinary octadecyl silane (C 18 ) columns and HSCCC. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Numerical simulations for effects of pressure and temperature on counter-current flow limitation at lower end of a vertical pipe

    International Nuclear Information System (INIS)

    Kusunoki, Takayoshi; Tomiyama, Akio; Murase, Michio; Takata, Takashi

    2015-01-01

    The purpose of this study is to derive a CCFL (counter-current flow limitation) correlation and its uncertainty for steam generator (SG) U-tubes in a pressurized water reactor. Pressure and temperature are very high in actual U-tubes. Hence, in this paper, we evaluated effects of pressure and temperature on CCFL characteristics using numerical simulations. Results computed with the k-ω SST turbulence model gave a trend opposite to the ROSA-IV/LSTF data in the pressure range of 1.0-7.0 MPa, and the computed falling water flow rates decreased as pressure increased. Because computations with the k-ω SST were unstable at lower pressures than 1.0 MPa, the laminar flow model was used even though it significantly overestimated falling water flow rates. The results showed that: (1) the flooding under steam-water conditions was mitigated more than that under air-water conditions; (2) the falling water flow rate had a maximum value at about 1.0 MPa; and (3) the laminar flow model resulted in an opposite trend to the ROSA-IV/LSTF data in the pressure range of 1.0-7.0 MPa, as the k-ω SST turbulence model did. Thus, we concluded that accurate measurements should be made in a wide range of pressures using a single vertical pipe in order to confirm effects of fluid properties on CCFL. (author)

  3. Isolation of sutherlandins A, B, C and D from Sutherlandia frutescens (L.) R. Br. by counter-current chromatography using spiral tubing support rotors.

    Science.gov (United States)

    Chen, Cuiping; Folk, William R; Lazo-Portugal, Rodrigo; Finn, Thomas M; Knight, Martha

    2017-07-28

    Spiral countercurrent-chromatography has great potential for improving the capacity and efficiency of purification of secondary metabolites, and here we describe applications useful for the isolation of flavonoids from the widely used South African medicinal plant, Sutherlandia frutescens (L.) R. Br. In the spiral tubing support rotor, STS-4 for high-speed counter-current chromatography, several polar butanol aqueous solvent systems were selected using a logK plot, and the novel flavonol glycosides (sutherlandins A-D) were well separated by the optimized solvent system (ethyl acetate:n-butanol:acetic acid:water; 5:1:0.3:6 by vol.). The yield of purified flavonoids from 0.9g extract varied from 8.6mg to 54mg of the sutherlandins for a total of 85.3mg. The same extract was fractionated in the new STS-12 rotor of the same outside dimensions but with more radial channels forming 12 loops of the tubing instead of 4. The rotor holds more layers and increased length of tubing. From 0.9g extract the STS-12 rotor yielded more recovery of 110.4mg total with amounts varying from 11.2mg to 64mg of the sutherlandins and apparent increased separation efficiency as noted by less volume of each fraction peak. Thus from 1-g amounts of extract, good recovery of the flavonoids was achieved in the butanol aqueous solvent system. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Preparative isolation of alkaloids from Dactylicapnos scandens using pH-zone-refining counter-current chromatography by changing the length of the separation column.

    Science.gov (United States)

    Wang, Xiao; Dong, Hongjing; Yang, Bin; Liu, Dahui; Duan, Wenjuan; Huang, Luqi

    2011-12-01

    pH-Zone-refining counter-current chromatography was successfully applied for the preparative separation of alkaloids from Dactylicapnos scandens. The two-phase solvent system was composed of petroleum ether-ethyl acetate-methanol-water (3:7:1:9, v/v), where 20 mM of triethylamine (TEA) was added to the upper phase as a retainer and 5 mM of hydrochloric acid (HCl) to the aqueous phase as an eluter. In this experiment, the apparatus with an adjustable length of the separation column was used for the separation of alkaloids from D. scandens and the resolution of the compounds can be remarkably improved by increasing the length of the separation column. As a result, 70 mg protopin, 30 mg (+) corydine, 120 mg (+) isocorydine and 40 mg (+) glaucine were obtained from 1.0 g of the crude extracts and each with 99.2%, 96.5%, 99.3%, 99.5% purity as determined by HPLC. The chemical structures of these compounds were confirmed by positive ESI-MS and (1)H NMR. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Passive restriction of blood flow and counter-current heat exchange via lingual retia in the tongue of a neonatal gray whale Eschrichtius robustus (Cetacea, Mysticeti).

    Science.gov (United States)

    Ekdale, Eric G; Kienle, Sarah S

    2015-04-01

    Retia mirabilia play broad roles in cetacean physiology, including thermoregulation during feeding and pressure regulations during diving. Vascular bundles of lingual retia are described within the base of the tongue of a neonatal female gray whale (Eschrichtius robustus). Each rete consists of a central artery surrounded by four to six smaller veins. The retia and constituent vessels decrease in diameter as they extend anteriorly within the hyoglossus muscle from a position anterior to the basihyal cartilage toward the apex of the tongue. The position of the retia embedded in the hyoglossus and the anterior constriction of the vessels differs from reports of similar vascular bundles that were previously identified in gray whales. The retia likely serve as a counter-current heat exchange system to control body temperature during feeding. Cold blood flowing toward the body center within the periarterial veins would accept heat from warm blood in the central artery flowing toward the anterior end of the tongue. Although thermoregulatory systems have been identified within the mouths of a few mysticete species, the distribution of such vascular structures likely is more widespread among baleen whales than has previously been described. © 2015 Wiley Periodicals, Inc.

  6. Preparative isolation and purification of seven compounds from Hibiscus mutabilis L. leaves by two-step high-speed counter-current chromatography

    Directory of Open Access Journals (Sweden)

    Hou Zhuoni

    2015-01-01

    Full Text Available Seven compounds from Hibiscus mutabilis L. leaves were first successfully achieved by two-step high-speed counter-current chromatography with two-phase solvent system composed of n-butanol-ethyl acetate-water (1:6:9, v/v/v and n-hexane-ethyl acetate-methanol-water (3:5:3:5, v/v/v/v/. The critical experimental parameters of first-step separation were optimized with response surface methodology as follows: flow rate was 1.1 mL/min, revolution speed was 800 rpm and temperature was 30°C. Under the optimal conditions, around 5.0 mg of salicylic acid, 13.6 mg of rutin, 5.5 mg of genistein were obtained in 100 mg crude sample. Then, 9.2 mg of potengriffioside A, 4.7 mg of kaempferol 3-O-rutinoside, 3.0 mg of steppogenin and 2.5 mg of emodin were obtained by second-step separation. The purities of the seven compounds determined by UPLC were 96.2%, 93.8%, 95.4%, 94.3%, 98.0%, 94.1% and 90.8%, respectively. Their chemical structures were identified by electron spray ionization mass spectroscopy (ESI-MS and 1H, 13C nuclear magnetic resonance (NMR. Furthermore, compound steppogenin and genistein were first reported from Hibiscus mutabilis L. The purification method was simple, efficient and evaded tedious separation process.

  7. Isolation of two new prenylated flavonoids from Sinopodophyllum emodi fruit by silica gel column and high-speed counter-current chromatography.

    Science.gov (United States)

    Sun, Yanjun; Sun, Yinshi; Chen, Hui; Hao, Zhiyou; Wang, Junmin; Guan, Yanbin; Zhang, Yanli; Feng, Weisheng; Zheng, Xiaoke

    2014-10-15

    Two new prenylated flavonoids, sinoflavonoids A-B, were isolated from the dried fruits of Sinopodophyllum emodi by silica gel column chromatography (SGCC) and high-speed counter-current chromatography (HSCCC). The 95% ethanol extract was partitioned with petroleum ether, dichloromethane, ethyl acetate, and n-butanol in water, respectively. The ethyl acetate fraction was pre-separated by SGCC with a petroleum ether-acetone gradient. The eluates containing target compounds were further separated by HSCCC with n-hexane-ethyl acetate-methanol-water (4:6:4:4, v/v). Finally, 17.3mg of sinoflavonoid A and 25.9mg of sinoflavonoid B were obtained from 100mg of the pretreated concentrate. The purities of sinoflavonoid A and sinoflavonoid B were 98.47% and 99.38%, respectively, as determined by HPLC. Their structures were elucidated on the basis of spectroscopic evidences (HR-ESI-MS, (1)H-NMR, (13)C-NMR, HSQC, HMBC). The separation procedures proved to be efficient, especially for trace prenylated flavonoids. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Characterizing the interaction between enantiomers of eight psychoactive drugs and highly sulfated-β-cyclodextrin by counter-current capillary electrophoresis.

    Science.gov (United States)

    Asensi-Bernardi, Lucía; Escuder-Gilabert, Laura; Martín-Biosca, Yolanda; Sagrado, Salvador; Medina-Hernández, María José

    2014-01-01

    The estimation of apparent binding constants and limit mobilities of the complexes of the enantiomers that characterize the interaction of enantiomers with chiral selectors, in this case highly sulfated β-cyclodextrin, was approached using a simple and economic electrophoretic modality, the complete filling technique (CFT) in counter-current mode. The enantiomers of eight psychoactive drugs, four antihistamines (dimethindene, promethazine, orphenadrine and terfenadine) and four antidepressants (bupropion, fluoxetine, nomifensine and viloxazine) were separated for the first time for this cyclodextrin (CD). Estimations of thermodynamic and electrophoretic enantioselectivies were also performed. Results indicate that, in general, thermodynamic enantioselectivity is the main component explaining the high resolution found, but also one case suggests that electrophoretic enantioselectivity itself is enough to obtain a satisfactory resolution. CFT results advantageous compared with conventional capillary electrophoresis (CE) and partial filling technique (PFT) for the study of the interaction between drugs and chiral selectors. It combines the use of a simple fitting model (as in CE), when the enantiomers do not exit the chiral selector plug during the separation (i.e. mobility of electroosmotic flow larger than mobility of CD), and drastic reduction of the consumption (and cost; ~99.7%) of the CD reagent (as in PFT) compared with the conventional CE. Copyright © 2013 John Wiley & Sons, Ltd.

  9. Offline coupling of high-speed counter-current chromatography and gas chromatography/mass spectrometry generates a two-dimensional plot of toxaphene components.

    Science.gov (United States)

    Kapp, Thomas; Vetter, Walter

    2009-11-20

    High-speed counter-current chromatography (HSCCC), a separation technique based solely on the partitioning of solutes between two immiscible liquid phases, was applied for the fractionation of technical toxaphene, an organochlorine pesticide which consists of a complex mixture of structurally closely related compounds. A solvent system (n-hexane/methanol/water 34:24:1, v/v/v) was developed which allowed to separate compounds of technical toxaphene (CTTs) with excellent retention of the stationary phase (S(f) = 88%). Subsequent analysis of all HSCCC fractions by gas chromatography coupled to electron-capture negative ion mass spectrometry (GC/ECNI-MS) provided a wealth of information regarding separation characteristics of HSCCC and the composition of technical toxaphene. The visualization of the large amount of data obtained from the offline two-dimensional HSCCC-GC/ECNI-MS experiment was facilitated by the creation of a two-dimensional (2D) contour plot. The contour plot not only provided an excellent overview of the HSCCC separation progress, it also illustrated the differences in selectivity between HSCCC and GC. The results of this proof-of-concept study showed that the 2D chromatographic approach involving HSCCC facilitated the separation of CTTs that coelute in unidimensional GC. Furthermore, the creation of 2D contour plots may provide a useful means of enhancing data visualization for other offline two-dimensional separations.

  10. Preparative separation of sulfur-containing diketopiperazines from marine fungus Cladosporium sp. using high-speed counter-current chromatography in stepwise elution mode.

    Science.gov (United States)

    Gu, Binbin; Zhang, Yanying; Ding, Lijian; He, Shan; Wu, Bin; Dong, Junde; Zhu, Peng; Chen, Juanjuan; Zhang, Jinrong; Yan, Xiaojun

    2015-01-09

    High-speed counter-current chromatography (HSCCC) was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs) (including two new compounds cladosporin A (1) and cladosporin B (3), and a known compound haematocin (2)) from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v) and (2:1:2:1, v/v), in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was performed on 300 mg of crude sample yielding 26.7 mg of compound 3 at a purity of over 95%, 53.6 mg of a mixture of compounds 1 and 2, which was further separated by preparative-HPLC yielding 14.3 mg of compound 1 and 25.4 mg of compound 2 each at a purity of over 95%. Their structures were established by spectroscopic methods. The sulfur-containing DKPs suppressed the proliferation of hepatocellular carcinoma cell line HepG2. The present work represents the first application of HSCCC in the efficient preparation of marine fungal natural products.

  11. Preparative Separation of Sulfur-Containing Diketopiperazines from Marine Fungus Cladosporium sp. Using High-Speed Counter-Current Chromatography in Stepwise Elution Mode

    Directory of Open Access Journals (Sweden)

    Binbin Gu

    2015-01-01

    Full Text Available High-speed counter-current chromatography (HSCCC was successively applied to the separation of three sulfur-containing diketopiperazines (DKPs (including two new compounds cladosporin A (1 and cladosporin B (3, and a known compound haematocin (2 from a marine fungus Cladosporium sp. The two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water at (1:1:1:1, v/v and (2:1:2:1, v/v, in stepwise elution mode, was used for HSCCC. The preparative HSCCC separation was performed on 300 mg of crude sample yielding 26.7 mg of compound 3 at a purity of over 95%, 53.6 mg of a mixture of compounds 1 and 2, which was further separated by preparative-HPLC yielding 14.3 mg of compound 1 and 25.4 mg of compound 2 each at a purity of over 95%. Their structures were established by spectroscopic methods. The sulfur-containing DKPs suppressed the proliferation of hepatocellular carcinoma cell line HepG2. The present work represents the first application of HSCCC in the efficient preparation of marine fungal natural products.

  12. Preparative Separation and Purification of Four Glycosides from Gentianae radix by High-Speed Counter-Current Chromatography and Comparison of Their Anti-NO Production Effects

    Directory of Open Access Journals (Sweden)

    Bao Chen

    2017-11-01

    Full Text Available Secoiridoid and iridoid glycosides are the main active components of Gentianae radix. In this work, one iridoid and three secoiridoid glycosides from Gentianae radix have been purified by high-speed counter-current chromatography in two runs using different solvent systems. Ethyl acetate–n-butanol–water (2:1:3, v/v/v was the optimum solvent system to purify ca. 4.36 mg of loganic acid, 3.05 mg of swertiamarin, and 35.66 mg of gentiopicroside with 98.1%, 97.2% and 98.6% purities, respectively, while 31.15 mg of trifloroside with 98.9% purity was separated using hexane–ethyl acetate–methanol–water (1:3:1:3, v/v/v/v. The structures of the glycosides were identified by mass spectrometry and NMR. After separation, the anti-nitric oxide production effects of the compounds on lipopolysaccharide-induced BV-2 murine microglial cells were also evaluated. All of the compounds inhibited the production of nitric oxide in lipopolysaccharide-induced BV-2 cells with high cell viabilities in a concentration-dependent manner, which demonstrated that were able to be used as a nitric oxide inhibitor.

  13. Preparative isolation and purification of three stilbene glycosides from the tibetan medicinal plant Rheum tanguticum maxim. Ex Balf. by high-speed counter-current chromatography.

    Science.gov (United States)

    Zhao, Xiao-Hui; Han, Fa; Li, Yu-Lin; Yue, Hui-Lan

    2013-02-01

    Stilbene glycosides are the primary constituents of Rheum tanguticum Maxim. ex Balf., to which different bioactivities has been attributed, including: anti-HIV, anti-oxidant, anti-tumour, anti-malarial, and anti-allergy activity. However, effective methods for the isolation and purification of stilbene glycosides, such as trans-rhapontin, cis-rhapontin and trans-desoxyrhaponticin, from this herb are not currently available. To develop an efficient method for the preparative isolation and purification of three stilbene glycosides from Rheum tanguticum Maxim. ex Balf. via high-speed counter-current chromatography (HSCCC). A solvent system composed of chloroform:n-butanol:methanol:water (4:1:3:2, v/v/v/v) was developed for the separation. The upper phase was used as the stationary phase, and the lower phase was used as the mobile phase. The flow rate was 1.8 mL/min. The apparatus was controlled at 800 rpm and 25 °C, and the effluent was monitored at 280 nm. Chemical constituents were analysed by high-performance liquid chromatography (HPLC), and their structures were identified by ¹H- and ¹³C-NMR. Under the optimised conditions, 25.5 mg trans-rhapontin, 16.0 mg cis-rhapontin and 20.5 mg trans-desoxyrhaponticin were separated from 80 mg crude sample; the isolates had purities of 99.6, 97.2 and 99.2%, respectively. A simple and efficient HSCCC method has been optimised for the preparative separation of stilbene glycosides from Rheum tanguticum Maxim. ex Balf. Copyright © 2012 John Wiley & Sons, Ltd.

  14. Preparative isolation and purification of four flavonoids from the petals of Nelumbo nucifera by high-speed counter-current chromatography.

    Science.gov (United States)

    Xingfeng, Guo; Daijie, Wang; Wenjuan, Duan; Jinhua, Du; Xiao, Wang

    2010-01-01

    Flavonoids, the primary constituents of the petals of Nelumbo nucifera, are known to have antioxidant properties and antibacterial bioactivities. However, efficient methods for the preparative isolation and purification of flavonoids from this plant are not currently available. To develop an efficient method for the preparative isolation and purification of flavonoids from the petals of N. nucifera by high-speed counter-current chromatography (HSCCC). Following an initial clean-up step on a polyamide column, HSCCC was utilised to separate and purify flavonoids. Purities and identities of the isolated compounds were established by HPLC-PAD, ESI-MS, (1)H-NMR and (13)C-NMR. The separation was performed using a two-phase solvent system composed of ethyl acetate-methanol-water-acetic acid (4 : 1 : 5 : 0.1, by volume), in which the upper phase was used as the stationary phase and the lower phase was used as the mobile phase at a flow-rate of 1.0 mL/min in the head-to-tail elution mode. Ultimately, 5.0 mg syringetin-3-O-beta-d-glucoside, 6.5 mg quercetin-3-O-beta-d-glucoside, 12.8 mg isorhamnetin-3-O-beta-d-glucoside and 32.5 mg kaempferol-3-O-beta-d-glucoside were obtained from 125 mg crude sample. The combination of HSCCC with a polyamide column is an efficient method for the preparative separation and purification of flavonoids from the petals of N. nucifera. (c) 2009 John Wiley & Sons, Ltd.

  15. On-line coupling of counter-current chromatography and macroporous resin chromatography for continuous isolation of arctiin from the fruit of Arctium lappa L.

    Science.gov (United States)

    Guo, Mengzhe; Liang, Junling; Wu, Shihua

    2010-08-13

    In this work, we have developed a novel hybrid two-dimensional counter-current chromatography and liquid chromatography (2D CCC x LC) system for the continuous purification of arctiin from crude extract of Arctium lappa. The first dimensional CCC column has been designed to fractionalize crude complex extract into pure arctiin effluent using a one-component organic/salt-containing system, and the second dimensional LC column has been packed with macroporous resin for on-line adsorption, desalination and desorption of arctiin which was effluent purified from the first CCC dimension. Thus, the crude arctiin mixture has been purified efficiently and conveniently by on-line CCC x LC in spite of the use of a salt-containing solvent system in CCC separation. As a result, high purity (more than 97%) of arctiin has been isolated by repeated injections both using the ethyl acetate-8% sodium chloride aqueous solution and butanol-1% sodium chloride aqueous solution. By contrast with the traditional CCC processes using multi-component organic/aqueous solvent systems, the present on-line CCC x LC process only used a one-component organic solvent and thus the solvent is easier to recover and regenerate. All of used solvents such as ethyl acetate, n-butanol and NaCl aqueous solution are low toxicity and environment-friendly. Moreover, the lower phase of salt-containing aqueous solution used as mobile phase, only contained minor organic solvent, which will save much organic solvent in continuous separation. In summary, our results indicated that the on-line hybrid 2D CCC x LC system using one-component organic/salt-containing aqueous solution is very promising and powerful tool for high-throughput purification of arctiin from fruits of A. lappa. 2010 Elsevier B.V. All rights reserved.

  16. Efficient Preparation of Streptochlorin from Marine Streptomyces sp. SYYLWHS-1-4 by Combination of Response Surface Methodology and High-Speed Counter-Current Chromatography

    Directory of Open Access Journals (Sweden)

    Lin Li

    2016-05-01

    Full Text Available Since first isolated from the lipophilic extract of Streptomyces sp. SF2583, streptochlorin, has attracted a lot of attention because of its various pharmacological properties, such as antibiotic, antiallergic, antitumor, and anti-inflammatory activities. For the efficient preparation of streptochlorin from a producing strain Streptomyces sp. SYYLWHS-1-4, we developed a combinative method by using response surface methodology (RSM and high-speed counter-current chromatography (HSCCC. In the fermentation process, we used RSM to optimize the condition for the efficient accumulation of streptochlorin, and the optimal parameters were: yeast extract 1.889 g/L, soluble starch 8.636 g/L, K2HPO4 0.359 g/L, CaCl2 2.5 g/L, MgSO4 0.625 g/L, marine salt 25 g/L, medium volume 50%, initial pH value 7.0, temperature 27.5 °C, which enhanced streptochlorin yield by 17.7-fold. During the purification process, the preparative HSCCC separation was performed using a petroleum ether–ethyl acetate–methanol–water (9:0.8:5:5, v/v/v/v biphasic solvent system, where 300 mg of crude sample yielded 16.5 mg streptochlorin with over 95% purity as determined by UPLC. Consequently, the combination method provided a feasible strategy for highly effective preparation of streptochlorin, which ensured the supply of large amounts of streptochlorin for in vivo pharmacological assessments or other requirements.

  17. Separation of betacyanins from purple flowers of Gomphrena globosa L. by ion-pair high-speed counter-current chromatography.

    Science.gov (United States)

    Spórna-Kucab, Aneta; Jagodzińska, Joanna; Wybraniec, Sławomir

    2017-03-17

    Betacyanins, known as antioxidants and chemopreventive natural compounds with colourful properties, were extracted from purple flowers of Gomphrena globosa L. belonging to the Amaranthaceae family and separated for the first time by ion-pair high-speed counter-current chromatography (HSCCC). The pigments were detected by LC-DAD-ESI-MS/MS technique. Separation of betacyanins (300mg) by HSCCC was accomplished in four solvent systems: tert-butyl methyl ether - butanol - acetonitrile - water (0.7% and 1.0% HFBA - heptafluorobutyric acid - system I and III) and tert-butyl methyl ether - butanol - methanol - water (0.7% and 1.0% HFBA - system II and IV) (2:2:1:5, v/v/v/v) in the head-to-tail mode. The mobile phase (aqueous phase) was run at 2.0ml/min and the column rotation speed was 860rpm. The applied systems enabled to study the influence of HFBA concentration as well as systems polarity on betacyanins separation. Comparison of the systems containing 0.7% HFBA (systems I-II) demonstrates that the replacement of acetonitrile by methanol increases the resolution (R s ) between all betacyanins and does not influence the retention of the stationary phase (S f =76%). Higher concentration of the acid in systems III-IV slightly decreases S f to 71% in the systems with 1.0% HFBA. Comparison of the resolution values for betacyanins in the systems with 0.7% and 1.0% HFBA demonstrates that higher concentration of the acid improves the separation effectiveness for all betacyanins as a result of increasing of the chemical affinity of the pigments to the organic stationary phase in HSCCC. The systems III-IV with 1% HFBA are the most effective for the separation of all the studied betacyanins. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Studies on polar high-speed counter-current chromatographic systems in separation of amaranthine-type betacyanins from Celosia species.

    Science.gov (United States)

    Spórna-Kucab, Aneta; Milo, Angelika; Kumorkiewicz, Agnieszka; Wybraniec, Sławomir

    2018-01-15

    Betacyanins, natural plant pigments exhibiting antioxidant and chemopreventive properties, were extracted from Celosia spicata (Thouars) Spreng. inflorescences and separated by high-speed counter-current chromatography (HSCCC) in two polar solvent systems composed of: TBME - 1-BuOH - ACN - H 2 O (0.7% HFBA, 2:2:1:5, v/v/v/v) (system I) and EtOH - ACN - 1-PrOH - (NH 4 ) 2 SO 4satd.soln - H 2 O (0.5:0.5:0.5:1.2:1, v/v/v/v/v) (system II). The systems were used in the head-to-tail (system I) and tail-to-head (system II) mode. The flow rate of the mobile phase was 2.0 ml/min and the column rotation speed was 860 rpm. The retention of the stationary phase was 73.5% (system I) and 80.0% (system II). For the identification of separated betacyanins in the crude extract as well as in the HSCCC fractions, LC-DAD-ESI-MS/MS analyses were performed. Depending on the target compounds, each of the systems exhibit meaningfully different selectivity and applicability. For the pairs of amaranthines (1/1') and betanins (2/2'), the best choice is the system II, but the acylated amaranthine pairs (3/3' and 4/4') can be resolved only in the ion-pair system I. For the indication of the most suitable solvent system for Celosia plumosa hort., Celosia cristata L. and Celosia spicata (Thouars) Spreng. species, the profiles of betacyanins in different plant parts were studied. Copyright © 2017. Published by Elsevier B.V.

  19. Isolation of cytotoxic diterpenoids from the Chilean medicinal plant Azorella compacta Phil from the Atacama Desert by high-speed counter-current chromatography.

    Science.gov (United States)

    Bórquez, Jorge; Bartolucci, Nandy López; Echiburú-Chau, Carlos; Winterhalter, Peter; Vallejos, Javier; Jerz, Gerold; Simirgiotis, Mario J

    2016-06-01

    Azorella compacta (Apiaceae) is a native Chilean cushion shrub which produces a resin containing mulinane and azorellane diterpenoids. This plant has been used since pre-Colombian times to treat inflammation and dental neuralgias. In this work the first preparative fractionation of diterpenoids present in this plant by means of high-speed counter-current chromatography (HSCCC) was applied, and cytotoxic effects of the isolated compounds were evaluated for the first time against a panel of MCF7 cells. The major compounds isolated were identified by means of spectroscopy as azorellanol, 13α, 14α-dihydroxymulin-11-en-20-oic acid, mulinolic acid, mulin-11,13-dien-20-oic acid, 17-acetoxy-mulin-11,13-dien-20 oic acid, and 17-acetoxy-mulinic acid (compounds 7, 9-11 and 13, respectively), and four minor diterpenoids [7-deacetyl-azorellanol (6), 13-epi-azorellanol, 7-acetoxy-mulin-9,12-diene, and 17-acetoxy-mulin-11,13-dien-20-oic acid (compounds 4, 8 and 12)], together with three new minor diterpenoids: 13β,14β-dihydroxymulin-11-en-20-oic acid (1), 13-epiazorellanone (2) and 13-epi-7-deacetyl-azorellanol (3) were identified. Besides, compounds 4, 6, 7, 8 and 11 displayed good cytotoxic activity (less than 50% cell viability at 100 µM). Among them, compound 7, an acetylated azorellane, was the most active. HSCCC allowed the isolation of 13 diterpenoids present in A. compacta. Three compounds are reported for the first time. Isolated azorellanes are more potent cytotoxic agents than are mulinanes. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  20. Thermal and single frequency counter-current ultrasound pretreatments of sodium caseinate: enzymolysis kinetics and thermodynamics, amino acids composition, molecular weight distribution and antioxidant peptides.

    Science.gov (United States)

    Abdualrahman, Mohammed Adam Y; Ma, Haile; Zhou, Cunshan; Yagoub, Abu ElGasim A; Hu, Jiali; Yang, Xue

    2016-12-01

    Due to the disadvantages of traditional enzymolysis, pretreatments are crucial to enhance protein enzymolysis. Enzymolysis kinetics and thermodynamics, amino acids composition, molecular weight distribution, fluorescence spectroscopy and antioxidant activity of thermal (HT) and single frequency counter-current ultrasound (SCFU) pretreated sodium caseinate (NaCas) were studied. Enzymolysis of untreated NaCas (control) improved significantly (P < 0.05) by SFCU and followed by HT. Values of the Michaelis-Menten constant (K M ) of SFCU and HT were 0.0212 and 0.0250, respectively. HT and SFCU increased (P < 0.05) the reaction rate constant (k) by 38.64 and 90.91%, respectively at 298 K. k values decreased with increasing temperature. The initial activation energy (46.39 kJ mol -1 ) reduced (P < 0.05) by HT (39.66 kJ mol -1 ) and further by SFCU (33.42 kJ mol -1 ). SFCU-pretreated NaCas hydrolysates had the highest contents of hydrophobic, aromatic, positively and negatively charged amino acids. Medium-sized peptides (5000-1000 Da) are higher in SFCU (78.11%) than HT and the control. SFCU induced molecular unfolding of NaCas proteins. Accordingly, SFCU-pretreated NaCas hydrolysate exhibited the highest scavenging activity on DPPH and hydroxyl radicals, reducing power, and iron chelating ability. SFCU pretreatment would be a useful tool for production of bioactive peptides from NaCas hydrolysate. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  1. An efficient and target-oriented sample enrichment method for preparative separation of minor alkaloids by pH-zone-refining counter-current chromatography.

    Science.gov (United States)

    Feng, Rui-Hong; Hou, Jin-Jun; Zhang, Yi-Bei; Pan, Hui-Qin; Yang, Wenzhi; Qi, Peng; Yao, Shuai; Cai, Lu-Ying; Yang, Min; Jiang, Bao-Hong; Liu, Xuan; Wu, Wan-Ying; Guo, De-An

    2015-08-28

    An efficient and target-oriented sample enrichment method was established to increase the content of the minor alkaloids in crude extract by using the corresponding two-phase solvent system applied in pH-zone-refining counter-current chromatography. The enrichment and separation of seven minor indole alkaloids from Uncaria rhynchophylla (Miq.) Miq. ex Havil(UR) were selected as an example to show the advantage of this method. An optimized two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (3:7:1:9, v/v) was used in this study, where triethylamine (TEA) as the retainer and hydrochloric acid (HCl) as the eluter were added at the equimolar of 10mM. Crude alkaloids of UR dissolved in the corresponding upper phase (containing 10mM TEA) were extracted twice with lower phase (containing 10mM TEA) and lower phase (containing 10mM HCl), respectively, the second lower phase extract was subjected to pH-zone-refining CCC separation after alkalization and desalination. Finally, from 10g of crude alkaloids, 4g of refined alkaloids was obtained and the total content of seven target indole alkaloids was increased from 4.64% to 15.78%. Seven indole alkaloids, including 54mg isocorynoxeine, 21mg corynoxeine, 46mg isorhynchophylline, 35mg rhynchophylline, 65mg hirsutine, 51mg hirsuteine and 27mg geissoschizine methylether were all simultaneously separated from 2.5g of refined alkaloids, with the purity of 86.4%, 97.5%, 90.3%, 92.1%, 98.5%, 92.3%, and 92.8%, respectively. The total content and purities of the seven minor indole alkaloids were tested by HPLC and their chemical structures were elucidated by ESI-HRMS and (1)H NMR. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Study of counter current flow limitation model of MARS-KS and SPACE codes under Dukler's air/water flooding test conditions

    International Nuclear Information System (INIS)

    Lee, Won Woong; Kim, Min Gil; Lee, Jeong Ik; Bang, Young Seok

    2015-01-01

    In particular, CCFL(the counter current flow limitation) occurs in components such as hot leg, downcomer annulus and steam generator inlet plenum during LOCA which is possible to have flows in two opposite directions. Therefore, CCFL is one of the thermal-hydraulic models which has significant effect on the reactor safety analysis code performance. In this study, the CCFL model will be evaluated with MARS-KS based on two-phase two-field governing equations and SPACE code based on two-phase three-field governing equations. This study will be conducted by comparing MARS-KS code which is being used for evaluating the safety of a Korean Nuclear Power Plant and SPACE code which is currently under assessment for evaluating the safety of the designed nuclear power plant. In this study, comparison of the results of liquid upflow and liquid downflow rate for different gas flow rate from two code to the famous Dukler's CCFL experimental data are presented. This study will be helpful to understand the difference between system analysis codes with different governing equations, models and correlations, and further improving the accuracy of system analysis codes. In the nuclear reactor system, CCFL is an important phenomenon for evaluating the safety of nuclear reactors. This is because CCFL phenomenon can limit injection of ECCS water when CCFL occurs in components such as hot leg, downcomer annulus or steam generator inlet plenum during LOCA which is possible to flow in two opposite directions. Therefore, CCFL is one of the thermal-hydraulic models which has significant effect on the reactor safety analysis code performance. In this study, the CCFL model was evaluated with MARS-KS and SPACE codes for studying the difference between system analysis codes with different governing equations, models and correlations. This study was conducted by comparing MARS-KS and SPACE code results of liquid upflow and liquid downflow rate for different gas flow rate to the famous Dukler

  3. Distributed performance counters

    Science.gov (United States)

    Davis, Kristan D; Evans, Kahn C; Gara, Alan; Satterfield, David L

    2013-11-26

    A plurality of first performance counter modules is coupled to a plurality of processing cores. The plurality of first performance counter modules is operable to collect performance data associated with the plurality of processing cores respectively. A plurality of second performance counter modules are coupled to a plurality of L2 cache units, and the plurality of second performance counter modules are operable to collect performance data associated with the plurality of L2 cache units respectively. A central performance counter module may be operable to coordinate counter data from the plurality of first performance counter modules and the plurality of second performance modules, the a central performance counter module, the plurality of first performance counter modules, and the plurality of second performance counter modules connected by a daisy chain connection.

  4. Application of an efficient strategy based on liquid-liquid extraction, high-speed counter-current chromatography, and preparative HPLC for the rapid enrichment, separation, and purification of four anthraquinones from Rheum tanguticum.

    Science.gov (United States)

    Chen, Tao; Liu, Yongling; Zou, Denglang; Chen, Chen; You, Jinmao; Zhou, Guoying; Sun, Jing; Li, Yulin

    2014-01-01

    This study presents an efficient strategy based on liquid-liquid extraction, high-speed counter-current chromatography, and preparative HPLC for the rapid enrichment, separation, and purification of four anthraquinones from Rheum tanguticum. A new solvent system composed of petroleum ether/ethyl acetate/water (4:2:1, v/v/v) was developed for the liquid-liquid extraction of the crude extract from R. tanguticum. As a result, emodin, aloe-emodin, physcion, and chrysophanol were greatly enriched in the organic layer. In addition, an efficient method was successfully established to separate and purify the above anthraquinones by high-speed counter-current chromatography and preparative HPLC. This study supplies a new alternative method for the rapid enrichment, separation, and purification of emodin, aloe-emodin, physcione, and chrysophanol. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. New solvent systems for gradient counter-current chromatography in separation of betanin and its derivatives from processed Beta vulgaris L. juice.

    Science.gov (United States)

    Spórna-Kucab, Aneta; Garrard, Ian; Ignatova, Svetlana; Wybraniec, Sławomir

    2015-02-06

    Betalains, natural plant pigments, are beneficial compounds due to their antioxidant and possible chemoprotective properties. A mixture of betalains: betanin/isobetanin, decarboxybetanins and neobetanin from processed red beet roots (Beta vulgaris L.) juice was separated in food-grade, gradient solvent systems using high-performance counter-current chromatography (HPCCC). The decarboxylated and dehydrogenated betanins were obtained by thermal degradation of betanin/isobetanin from processed B. vulgaris L. juice under mild conditions. Two solvent systems (differing in their composition by phosphoric acid and ethanol volume gradient) consisting of BuOH-EtOH-NaClsolution-H2O-H3PO4 (v/v/v/v/v, 1300:200-1000:1300:700:2.5-10) in the 'tail-to-head' mode were run. The flow rate of the mobile phase (organic phase) was 1.0 or 2.0 ml/min and the column rotation speed was 1,600 rpm (20°C). The retention of the solvent system stationary phase (aqueous phase) was ca. 80%. The system with the acid and ethanol volume gradient consisting of BuOH-EtOH-NaClsolution-H2O-H3PO4 (v/v/v/v/v, 1300:200-240:1300:700:2.5-4.5) pumped at 2.0 ml/min was the most effective for a separation of betanin/isobetanin, 17-decarboxy-betanin/-isobetanin, 2-decarboxy-betanin/-isobetanin, 2,17-bidecarboxy-betanin/-isobetanin pairs as well as neobetanin. The pigments were detected by LC-DAD and LC-MS. The results are crucial in the application of completely food-grade solvent systems in separation of food-grade compounds as well, and the systems can possibly be extended to other ionizable and polar compounds with potential health benefits. In particular, the method is applicable for the isolation and purification of betalains present in such rich sources as B. vulgaris L. roots as well as cacti fruits and Amaranthaceae flowering plants due to modification possibilities of the solvent systems polarity. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Preparative Separation of Phenolic Compounds from Chimonanthus praecox Flowers by High-Speed Counter-Current Chromatography Using a Stepwise Elution Mode

    Directory of Open Access Journals (Sweden)

    Huaizhi Li

    2016-08-01

    Full Text Available High-speed counter-current chromatography (HSCCC has been successfully used for the separation of eight compounds from Chimonanthus praecox flowers. Firstly, the crude extract of Chimonanthus praecox flowers was dissolved in a two-phase solvent system composed of petroleum ether–ethyl acetate–methanol–H2O (5:5:3:7, v/v and divided into two parts: the upper phase (part I and the lower phase (part II. Then, HSCCC was applied to separate the phenolic acids from part I and part II, respectively. Considering the broad polarity range of target compounds in part I, a stepwise elution mode was established. Two optimal solvent systems of petroleum ether–ethyl acetate–methanol–H2O–formic acid (FA (5:5:3:7:0.02, 5:5:4.3:5.7:0.02, v/v were employed in this separation. Five phenylpropanoids and two flavonoids were successfully separated from 280 mg of part I, including 8.7 mg of 3,4-dihydroxy benzoic acid (a, 95.3% purity, 10.9 mg of protocatechualdehyde (b, 96.8% purity, 11.3 mg of p-coumaric acid (c, 98.9% purity, 12.2 mg of p-hydroxybenzaldehyde (d, 95.9% purity, 24.7 mg of quercetin (e, 97.3% purity, 33.8 mg of kaempferol (f, 96.8% purity, and 24.6 mg of 4-hydroxylcinnamic aldehyde (g, 98.0% purity. From 300 mg of part II, 65.7 mg of rutin (h, 98.2% purity, 7.5 mg of 3,4-dihydroxy benzoic acid (a, 77.4% purity, and 4.7 mg of protocatechualdehyde (b, 81.6% purity were obtained using the solvent system EtOAc–n-butanol (n-BuOH–FA–H2O (4:1:0.5:5, v/v. The structures of the eight pure compounds were confirmed by electrospray ionization-mass spectrometry (ESI-MS, 1H-NMR and 13C-NMR. To the best of our knowledge, compounds a–d and f were the first separated and reported from the Chimonanthus praecox flower extract.

  7. Preparative separation of two subsidiary colors of FD&C Yellow No. 5 (Tartrazine) using spiral high-speed counter-current chromatography.

    Science.gov (United States)

    Weisz, Adrian; Ridge, Clark D; Roque, Jose A; Mazzola, Eugene P; Ito, Yoichiro

    2014-05-23

    Specifications in the U.S. Code of Federal Regulations for the color additive FD&C Yellow No. 5 (Color Index No. 19140) limit the level of the tetrasodium salt of 4-[(4',5-disulfo[1,1'-biphenyl]-2-yl)hydrazono]-4,5-dihydro-5-oxo-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid and that of the trisodium salt of 4,4'-[4,5-dihydro-5-oxo-4-[(4-sulfophenyl)hydrazono]-1H-pyrazol-1,3-diyl]bis[benzenesulfonic acid], which are subsidiary colors abbreviated as Pk5 and Pk7, respectively. Small amounts of Pk5 and Pk7 are needed by the U.S. Food and Drug Administration for confirmatory analyses and for development of analytical methods. The present study describes the use of spiral high-speed counter-current chromatography (HSCCC) to separate the closely related minor components Pk5 and Pk7 from a sample of FD&C Yellow No. 5 containing ∼3.5% Pk5 and ∼0.7% Pk7. The separations were performed with highly polar organic/high-ionic strength aqueous two-phase solvent systems that were chosen by applying the recently introduced method known as graphic optimization of partition coefficients (Zeng et al., 2013). Multiple ∼1.0g portions of FD&C Yellow No. 5 (totaling 6.4g dye) were separated, using the upper phase of the solvent system 1-butanol/abs. ethanol/saturated ammonium sulfate/water, 1.7:0.3:1:1, v/v/v/v, as the mobile phase. After removing the ammonium sulfate from the HSCCC-collected fractions, these separations resulted in an enriched dye mixture (∼160mg) of which Pk5 represented ∼46% and Pk7, ∼21%. Separation of the enriched mixture, this time using the lower phase of that solvent system as the mobile phase, resulted in ∼61mg of Pk5 collected in fractions whose purity ranged from 88.0% to 92.7%. Pk7 (20.7mg, ∼83% purity) was recovered from the upper phase of the column contents. Application of this procedure also resulted in purifying the major component of FD&C Yellow No. 5 to >99% purity. The separated compounds were characterized by high-resolution mass

  8. Preparative separation of two subsidiary colors of FD&C Yellow No. 5 (Tartrazine) using spiral high-speed counter-current chromatography◊

    Science.gov (United States)

    Roque, Jose A.; Mazzola, Eugene P.; Ito, Yoichiro

    2014-01-01

    Specifications in the U.S. Code of Federal Regulations for the color additive FD&C Yellow No. 5 (Colour Index No. 19140) limit the level of the tetrasodium salt of 4-[(4',5-disulfo[1,1'-biphenyl]-2-yl)hydrazono]-4,5-dihydro-5-oxo-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid and that of the trisodium salt of 4,4'-[4,5-dihydro-5-oxo-4-[(4-sulfophenyl)hydrazono]-1H-pyrazol-1,3-diyl]bis[benzenesulfonic acid], which are subsidiary colors abbreviated as Pk5 and Pk7, respectively. Small amounts of Pk5 and Pk7 are needed by the U.S. Food and Drug Administration for confirmatory analyses and for development of analytical methods. The present study describes the use of spiral high-speed counter-current chromatography (HSCCC) with the recently introduced highly polar organic/high-ionic strength aqueous solvent systems to separate Pk5 and Pk7 from a sample of FD&C Yellow No. 5 containing ~3.5% Pk5 and ~0.7% Pk7. Multiple ~1.0 g portions of FD&C Yellow No. 5 (totaling 6.4 g dye) were separated, using the upper phase of the solvent system 1-BuOH/EtOHabs/saturated ammonium sulfate/water, 1.7:0.3:1:1, v/v/v/v, as the mobile phase. After applying a specially developed method for removing the ammonium sulfate from the HSCCC-collected fractions, these separations resulted in an enriched mixture (~160 mg) of Pk5 and Pk7 (~46% and ~21%, respectively). Separation of the enriched mixture, this time using the lower phase of that solvent system as the mobile phase, resulted in ~ 61 mg of Pk5 collected in fractions whose purity ranged from 88.0% to 92.7% (by HPLC at 254 nm). Pk7 (20.7 mg, ~83% purity) was recovered from the upper phase of the column content. Application of this procedure also resulted in purifying the major component of FD&C Yellow No. 5 to >99% purity. The separated compounds were characterized by high-resolution mass spectrometry and several 1H and 13C nuclear magnetic resonance spectroscopic techniques (COSY, NOESY, HSQC, and HMBC). PMID:24755184

  9. Portable microcomputer controlled radiation counter

    International Nuclear Information System (INIS)

    Mason, E.W.; Weber, J.M.

    1984-01-01

    A portable microcomputer controlled counter for use as a radiation counter is described. The counter uses digital processing of input pulses from a radiation detector. The number of counts received by the microcomputer per unit time is used to calculate a value for display using a calibration factor obtained during physical calibration of the instrument with a radiation source or with a pulse generator. The keyboard is used to enter calibration points. The number of calibration points which may be entered depends on the degree of accuracy desired by the user. The high voltage generator which drives the detector is triggered by pulses from the microcomputer in relation to the count rate. After processing the count, the resulting count rate or dose rate is displayed on the liquid crystal display. The counter is autoranging in which the decimal point is shifted as necessary by the microcomputer. The units displayed are determined by the user by means of a multiposition switch. Low battery and an overrange condition are displayed. An interface is provided via a connector to allow parallel transmission of data to peripheral devices. Low battery power consumption is featured. The counter is capable of providing more accurate readings than currently available counters

  10. An APC:WNT counter-current-like mechanism regulates cell division along the colonic crypt axis: a mechanism that explains how APC mutations induce proliferative abnormalities that drive colon cancer development.

    Directory of Open Access Journals (Sweden)

    Bruce M Boman

    2013-11-01

    Full Text Available APC normally down-regulates WNT signaling in human colon, and APC mutations cause proliferative abnormalities in premalignant crypts leading to colon cancer, but the mechanisms are unclear at the level of spatial and functional organization of the crypt. Accordingly, we postulated a counter-current-like mechanism based on gradients of factors (APC;WNT that regulate colonocyte proliferation along the crypt axis. During crypt renewal, stem cells (SCs at the crypt bottom generate non-SC daughter cells that proliferate and differentiate while migrating upwards. The APC concentration is low at the crypt bottom and high at the top (where differentiated cells reside. WNT signaling, in contrast, is high at the bottom (where SCs reside and low at the top. Given that WNT and APC gradients are counter to one another, we hypothesized that a counter-current-like mechanism exists. Since both APC and WNT signaling components (e.g. survivin are required for mitosis, this mechanism establishes a zone in the lower crypt where conditions are optimal for maximal cell division and mitosis orientation (symmetric versus asymmetric. APC haploinsufficiency diminishes the APC gradient, shifts the proliferative zone upwards, and increases symmetric division, which causes SC overpopulation. In homozygote mutant crypts, these changes are exacerbated. Thus, APC-mutation-induced changes in the counter-current-like mechanism cause expansion of proliferative populations (SCs, rapidly-proliferating cells during tumorigenesis. We propose this mechanism also drives crypt fission, functions in the crypt cycle, and underlies adenoma development. Novel chemoprevention approaches designed to normalize the two gradients and readjust the proliferative zone downwards, might thwart progression of these premalignant changes.

  11. An APC:WNT Counter-Current-Like Mechanism Regulates Cell Division Along the Human Colonic Crypt Axis: A Mechanism That Explains How APC Mutations Induce Proliferative Abnormalities That Drive Colon Cancer Development

    Science.gov (United States)

    Boman, Bruce M.; Fields, Jeremy Z.

    2013-01-01

    APC normally down-regulates WNT signaling in human colon, and APC mutations cause proliferative abnormalities in premalignant crypts leading to colon cancer, but the mechanisms are unclear at the level of spatial and functional organization of the crypt. Accordingly, we postulated a counter-current-like mechanism based on gradients of factors (APC;WNT) that regulate colonocyte proliferation along the crypt axis. During crypt renewal, stem cells (SCs) at the crypt bottom generate non-SC daughter cells that proliferate and differentiate while migrating upwards. The APC concentration is low at the crypt bottom and high at the top (where differentiated cells reside). WNT signaling, in contrast, is high at the bottom (where SCs reside) and low at the top. Given that WNT and APC gradients are counter to one another, we hypothesized that a counter-current-like mechanism exists. Since both APC and WNT signaling components (e.g., survivin) are required for mitosis, this mechanism establishes a zone in the lower crypt where conditions are optimal for maximal cell division and mitosis orientation (symmetric versus asymmetric). APC haploinsufficiency diminishes the APC gradient, shifts the proliferative zone upwards, and increases symmetric division, which causes SC overpopulation. In homozygote mutant crypts, these changes are exacerbated. Thus, APC-mutation-induced changes in the counter-current-like mechanism cause expansion of proliferative populations (SCs, rapidly proliferating cells) during tumorigenesis. We propose this mechanism also drives crypt fission, functions in the crypt cycle, and underlies adenoma development. Novel chemoprevention approaches designed to normalize the two gradients and readjust the proliferative zone downwards, might thwart progression of these premalignant changes. PMID:24224156

  12. Cerenkov counters at ISABELLE

    International Nuclear Information System (INIS)

    Etkin, A.; Kostoulas, I.; Leith, D.W.G.S.; Thun, R.

    1977-01-01

    The Cherenkov counter described for use at Isabelle is a threshold counter in which light is focussed on phototubes. The counter is applicable in large-angle, small-aperture magnetic spectrometers for measurement of particle yields at large p/sub T/. Three of these counters will provide complete π-K-p separation in the range of 7-20 GeV/c. Other Cherenkov counters are discussed and a bibliography of relevant literature on the counters utilizing photoionization is included

  13. CEDAR counter (internal part)

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    Here on the mounting bench. The counter is a differential Cerenkov, corrected for chromaticity, able to differentiate pions from kaons up to 350 GeV. Counters of this type were used in all SPS hadron beams.

  14. Whole Body Counters (rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Woodburn, John H. [Walter Johnson High School, Rockville, MD; Lengemann, Frederick W. [Cornell University

    1967-01-01

    Whole body counters are radiation detecting and measuring instruments that provide information about the human body. This booklet describes different whole body counters, scientific principles that are applied to their design, and ways they are used.

  15. Multimode pulse counter

    International Nuclear Information System (INIS)

    Natanzon, D.D.

    1982-01-01

    A pulse counter with code conversion is described. The counter is based on the integrated circuits of direct-counting devices of medium integration. The counter ensures various modes of pulse counting depending on the logical control signals: reversible, two-channel summing, one-channel summing binary, summing with ''storage'' signal code fixation without interrupting pulse counting. Arrangement of the suggested structure as a microcircuit of medium integration might contribute to reduction in the counter type nomenclature in digital families of widely used integrated circuits

  16. Separation of five compounds from leaves of Andrographis paniculata (Burm. f.) Nees by off-line two-dimensional high-speed counter-current chromatography combined with gradient and recycling elution.

    Science.gov (United States)

    Zhang, Li; Liu, Qi; Yu, Jingang; Zeng, Hualiang; Jiang, Shujing; Chen, Xiaoqing

    2015-05-01

    An off-line two-dimensional high-speed counter-current chromatography method combined with gradient and recycling elution mode was established to isolate terpenoids and flavones from the leaves of Andrographis paniculata (Burm. f.) Nees. By using the solvent systems composed of n-hexane/ethyl acetate/methanol/water with different volume ratios, five compounds including roseooside, 5,4'-dihydroxyflavonoid-7-O-β-d-pyranglucuronatebutylester, 7,8-dimethoxy-2'-hydroxy-5-O-β-d-glucopyranosyloxyflavon, 14-deoxyandrographiside, and andrographolide were successfully isolated. Purities of these isolated compounds were all over 95% as determined by high-performance liquid chromatography. Their structures were identified by UV, mass spectrometry, and (1) H NMR spectroscopy. It has been demonstrated that the combination of off-line two-dimensional high-speed counter-current chromatography with different elution modes is an efficient technique to isolate compounds from complex natural product extracts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. The first CEDAR counter

    CERN Multimedia

    CERN PhotoLab

    1976-01-01

    The first differential Cerenkov counter with chromatic corrections (called CEDAR) successfully tested at the PS in July 75. These counters were used in the SPS hadronic beams for particle identification. Some of the eight photomultipliers can be seen: they receive the light reflected back through the annular diaphragm. René Maleyran stands on the left.

  18. Current capabilities of the IRD-CNEN-RJ whole body counter for in vivo monitoring of internally deposited radionuclides in human body

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, Bernando Maranhao; Dantas, Ana Leticia Almeida; Lucena, Eder Augusto, E-mail: bmdantas@ird.gov.br, E-mail: adantas@ird.gov.br, E-mail: eder@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil). Lab. de Monitoracao In Vivo. Div. de Dosimetria

    2014-07-01

    Occupational exposure to radioactive materials may occur as a result of a variety of professional human activities, such as in nuclear industry; use of unsealed sources in nuclear medicine, biological research and agriculture; production of radiopharmaceuticals, as well as in mining and milling of minerals associated with naturally occurring radioactive materials. The IRD whole-body counter (UCCI) consists of a shielded room with internal dimensions of 2.5 m x 2.5 m x 2.5 m. The walls are made of steel and have a graded-Z interior lining made of 3 mm of lead, 1.5 mm of cadmium and 0.5 mm of copper. Such thin layers are aimed to reduce environmental sources of natural background radiation that would affect the measurements of radionuclides emitting low energy photons. An array of four HPGe detectors was used to perform low-energy measurements of radionuclides emitting photons in the energy range from 10 to 200 keV in the lungs, liver and bone tissue. Additionally, one NaI(Tl)8” x 4” and one NaI(Tl)3” x 3” scintillation detectors are used for measurements in the energy range from 100 up to 3000 keV. A configuration of detector supports allows setting up flexible counting geometries, i.e., whole body and specific organs such as head, lungs, liver and thyroid of an individual laid on a monitoring chair. The UCCI is able to perform in vivo measurement of a large variety of radionuclides emitting photons in the energy range from 10 to 3000 keV. The minimum detectable activities for most of the radionuclides of interest allow its application for occupational monitoring as well as in the case of accidental incorporations. (author)

  19. Black clay. Domestic stove based on counter current combustion, a principle used during the Iron Age and utilized in a baking oven from the Middle Ages; Sortemuld; Braendovn med modstroemsforbraending et princip fra jernalderen anvendt i bageovne fra middelalderen

    Energy Technology Data Exchange (ETDEWEB)

    Lund, E.

    1994-01-01

    Sortemuld (Black clay) ovens, based on the counter-current combustion principle, were used during the Iron Age and throughout the following centuries. It is claimed that the use of this technique results in the wood fuel being burnt so quickly that the oven temperature remains so high and for such a long time that the heat will be retained in the walls of such clay ovens. Prototype ovens were constructed, based on this principle, and various types of wood fuel were burnt in them. About 20 - 40 kg of fuel was combusted with each firing which lasted from 2-4 hours, answering to 20 - 40 kW/hrs. The carbon dioxide content reached 0.1% at times. The designs and construction of the prototypes ovens are described in detail and their performance documented. The text is illustrated with diagrams and the results of the performance testing are given in detail. (AB)

  20. Separation of calcium isotopes by counter-current electromigration in molten salts (1962); Separation des isotopes du calcium par electro-migration a contre-courant en sels fondus (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Menes, F; Dirian, G; Roth, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    The method of counter-current electromigration in molten salts has been applied to calcium bromide with an alkali metal bromide added to the cathode compartment. Enrichments on calcium-46 greater than a factor of two were obtained at the anode. The mass effect was found to be about 0.06. An estimation of the cost of energy for a process based on this method has been made. (authors) [French] La methode d'electro-migration a contre-courant en sels fondus a ete appliquee au bromure de calcium additionne dans le compartiment cathodique d'un bromure alcalin. On a pu ainsi obtenir avec surete des enrichissements anodiques superieurs a 2 sur l'isotope 46, determiner l'effet de masse (environ 0,06) et faire une estimation sommaire du cout energetique d'un procede base sur cette methode. (auteurs)

  1. Partition efficiencies of newly fabricated universal high-speed counter-current chromatograph for separation of two different types of sugar derivatives with organic-aqueous two-phase solvent systems

    Science.gov (United States)

    Shinomiya, Kazufusa; Sato, Kazuki; Yoshida, Kazunori; Tokura, Koji; Maruyama, Hiroshi; Yanagidaira, Kazuhiro; Ito, Yoichiro

    2013-01-01

    Universal high-speed counter-current chromatograph (HSCCC) was newly designed and fabricated in our laboratory. It holds a set of four column holders symmetrically around the rotary frame at a distance of 11.2 cm from the central axis. By engaging the stationary gear on the central axis of the centrifuge to the planetary gears on the column holder shaft through a set of idle gears, two pairs of diagonally located column holders simultaneously rotate about their own axes in the opposite directions: one forward (type-J planetary motion) and the other backward (type-I planetary motion) each synchronously with the revolution. Using the eccentric coil assembly, partition efficiencies produced by these two planetary motions were compared on the separation of two different types of sugar derivatives (4-methylumbelliferyl and 5-bromo-4-chloro-3-indoxyl sugar derivatives) using organic-aqueous two-phase solvent systems composed of n-hexane/ethyl acetate/1-butanol/methanol/water and aqueous 0.1 M sodium tetraborate, respectively. With lower phase mobile, better peak resolution was obtained by the type-J forward rotation for both samples probably due to higher retention of the stationary phase. With upper phase mobile, however, similar peak resolutions were obtained between these two planetary motions for both sugar derivatives. The overall results indicate that the present universal HSCCC is useful for counter-current chromatographic separation since each planetary motion has its specific applications: e.g., vortex CCC by the type-I planetary motion and HSCCC by the type-J planetary motion both for separation of various natural and synthetic products. PMID:24267319

  2. Counter-cryptanalysis

    NARCIS (Netherlands)

    M.M.J. Stevens (Marc); R. Canetti; J.A. Garay

    2013-01-01

    textabstractWe introduce \\emph{counter-cryptanalysis} as a new paradigm for strengthening weak cryptographic primitives against cryptanalytic attacks. Redesigning a weak primitive to more strongly resist cryptanalytic techniques will unavoidably break backwards compatibility. Instead,

  3. A Neutron Rem Counter

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, I Oe; Braun, J

    1964-01-15

    A neutron detector is described which measures the neutron dose rate in rem/h independently of the energy of the neutrons from thermal to 15 MeV. The detector consists of a BF{sub 3} proportional counter surrounded by a shield made of polyethylene and boron plastic that gives the appropriate amount of moderation and absorption to the impinging neutrons to obtain rem response. Two different versions have been developed. One model can utilize standard BF{sub 3} counters and is suitable for use in installed monitors around reactors and accelerators and the other model is specially designed for use in a portable survey instrument. The neutron rem counter for portable instruments has a sensitivity of 2.4 cps/mrem/h and is essentially nondirectional in response. With correct bias setting the counter is insensitive to gamma exposure up to 200 r/h from Co-60.

  4. Investigation of liquid film behavior at the onset of flooding during adiabatic counter-current air-water two-phase flow in an inclined pipe

    International Nuclear Information System (INIS)

    Deendarlianto; Ousaka, Akiharu; Kariyasaki, Akira; Fukano, Tohru

    2005-01-01

    The liquid film characteristics at the onset of flooding in an inclined pipe (16 mm i.d. and 2.2 m in length) have been investigated experimentally. A constant electric current method and visual observation were utilized to elucidate the flow mechanisms at the onset of flooding. Two mechanisms are clarified to control the flooding in lower flooding and upper flooding, respectively. The lower flooding occurred at lower liquid flow rate and high pipe inclination angle. In this mechanism, the liquid film does not block the pipe cross-section. On the other hand, the upper flooding occurred at higher liquid flow rate and low pipe inclination angle. In this case, blocking of the pipe cross-section by large wave and entrainment plays an important role. The experimental data indicated that there was no reversal motion of liquid film at the onset of flooding during the operation of both lower flooding and upper flooding. The effects of pipe inclination angle on the onset of flooding are also discussed

  5. Nuclear timer/counter

    International Nuclear Information System (INIS)

    Wuthayavanich, S.

    1978-01-01

    This thesis represents the development of a Timer/COUNTER compatible to the standard Nuclear Instrument Module Specifications. The unit exhibits high accuracy, light weight and ease of maintenance. The unit also has a built-in precision discriminator to discriminate unwanted signals that may cause interference in counting. With line frequency time base the timer can be preset in steps from 0.1 sec. to 9 x 10 5 min. The counter with six digits miniature display and an overflow output has a maximum counting rate of 10 MHz. The accumulated counting data can be transferred to a teletype or printer for hard copy printout with the aid of ORTEC 777 Line Printer or 432 A Print-out Control or any print out interface with input compatible to the print output of the Timer/Counter. Owing to its NIM compatibility the unit is directly powered by the NIM power supply

  6. An efficient anticoincidence counter

    CERN Multimedia

    1977-01-01

    This scintillation counter (about 25 cm diameter) was prepared at CERN for an experiment at the Saclay 600 MeV electron linac studying molecular processes originated in liquid hydrogen by muons. The counter is meant to surround the target and detect charged particles emerging from the hydrogen. The experiment was a CERN-Saclay collaboration which used the linac so as to take advantage of the time structure of the electron beam(see CERN Courier Sep 1977 and J. Bardin et al. Phys. Lett. B104 (1981) 320)

  7. Irradiated fuel bundle counter

    International Nuclear Information System (INIS)

    Campbell, J.W.; Todd, J.L.

    1975-01-01

    The design of a prototype safeguards instrument for determining the number of irradiated fuel assemblies leaving an on-power refueled reactor is described. Design details include radiation detection techniques, data processing and display, unattended operation capabilities and data security methods. Development and operating history of the bundle counter is reported. (U.S.)

  8. Irradiated fuel bundle counter

    International Nuclear Information System (INIS)

    Campbell, J.W.; Todd, J.L.

    1975-01-01

    The design of a prototype safeguards instrument for determining the number of irradiated fuel assemblies leaving an on-power refueled reactor is described. Design details include radiation detection techniques, data processing and display, unattended operation capabilities and data security methods. Development and operating history of the bundle counter is reported

  9. Whole-body counter

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, G A; Kosterev, V V

    1975-01-24

    A counter for detecting radiation of a man (CRM) is described, which consists of two measuring converters and a recording device. In order to obtain data on spatial distribution of a gamma-radiating nuclide studied, a fixed collimator and a mobile coder made of separate slit elements are placed between the measuring converters and an object investigated.

  10. Electromagnetically Operated Counter

    Science.gov (United States)

    Goldberg, H D; Goldberg, M I

    1951-12-18

    An electromagnetically operated counter wherein signals to be counted are applied to cause stepwise rotation of a rotatable element which is connected to a suitable register. The mechanism involved consists of a rotatable armature having three spaced cores of magnetic material and a pair of diametrically opposed electromagnets with a suitable pulsing circuit to actuate the magnets.

  11. Microchip Coulter particle counter

    DEFF Research Database (Denmark)

    Larsen, Ulrik Darling; Blankenstein, Gert; Branebjerg, J.

    1997-01-01

    This paper presents a micro device employing the Coulter principle for counting and sizing of living cells and particles in liquid suspension. The microchip Coulter particle counter (μCPC) has been employed in a planar silicon structure covered with glass, which enables detailed observation during...

  12. One-step separation and purification of three lignans and one flavonol from Sinopodophyllum emodi by medium-pressure liquid chromatography and high-speed counter-current chromatography.

    Science.gov (United States)

    Wang, Ping; Liu, Yongling; Chen, Tao; Xu, Wenhua; You, Jinmao; Liu, Yongjun; Li, Yulin

    2013-01-01

    Lignans and flavonols are the primary constituents of Sinopodophyllum emodi and have been used as cathartic, anthelmintic, chemotherapeutic and anti-hypertensive compounds. Although these compounds have been isolated, there have been no reports on the separation of 4'-demethyl podophyllotoxin, podophyllotoxin, deoxypodophyllotoxin and kaempferol in one step by medium-pressure liquid chromatography (MPLC) and high-speed counter-current chromatography (HSCCC). Development of an efficient method for the preparative separation and purification of three lignans and one flavonol from S. emodi. The precipitate of crude extracts was first separated by MPLC into four parts, numbered GJ-1, GJ-2, GJ-3 and GJ-4. GJ-1 was separated and purified by HSCCC using a solvent system composed of n-hexane:ethyl acetate:methanol:water (1.75:1.5:1:0.75, v/v/v/v). The purities of the target compounds were assessed using high-performance liquid chromatography (HPLC) and chemical structures were identified by (1) H-NMR and (13) C-NMR. The HSCCC and MPLC methods were successfully used for the preparative separation and purification of 4'-demethyl podophyllotoxin (8.5 mg, 92.4%), podophyllotoxin (40.1 mg, 92.1%), deoxypodophyllotoxin (4.6 mg, 98.1%), and kaempferol (1.6 mg, 96.7%) from a 100 mg sample. Three lignans (4'-demethyl podophyllotoxin, podophyllotoxin, deoxypodophyllotoxin) and one flavonol (kaempferol) were successfully isolated by HSCCC and MPLC in one step. Copyright © 2013 John Wiley & Sons, Ltd.

  13. An Efficient Method for the Preparative Isolation and Purification of Flavonoid Glycosides and Caffeoylquinic Acid Derivatives from Leaves of Lonicera japonica Thunb. Using High Speed Counter-Current Chromatography (HSCCC) and Prep-HPLC Guided by DPPH-HPLC Experiments.

    Science.gov (United States)

    Wang, Daijie; Du, Ning; Wen, Lei; Zhu, Heng; Liu, Feng; Wang, Xiao; Du, Jinhua; Li, Shengbo

    2017-02-02

    In this work, the n-butanol extract from leaves of Lonicera japonica Thunb. (L. japonica) was reacted with DPPH and subjected to a HPLC analysis for the guided screening antioxidants (DPPH-HPLC experiments). Then, nine antioxidants, including flavonoid glycosides and caffeoylquinic acid derivatives, were isolated and purified from leaves of L. japonica using high speed counter-current chromatography (HSCCC) and prep-HPLC. The n-butanol extract was firstly isolated by HSCCC using methyl tert-butyl ether/n-butanol/acetonitrile/water (0.5% acetic acid) (2:2:1:5, v/v), yielding five fractions F1, F2 (rhoifolin), F3 (luteoloside), F4 and F5 (collected from the column after the separation). The sub-fractions F1, F4 and F5 were successfully separated by prep-HPLC. Finally, nine compounds, including chlorogenic acid (1), lonicerin (2), rutin (3), rhoifolin (4), luteoloside (5), 3,4-Odicaffeoylquinic acid (6), hyperoside (7), 3,5-O-dicaffeoylquinic acid (8), and 4,5-O-dicaffeoylquinic acid (9) were obtained, respectively, with the purities over 94% as determined by HPLC. The structures were identified by electrospray ionization mass spectrometry (ESI-MS), 1H- and 13C-NMR. Antioxidant activities were tested, and the isolated compounds showed strong antioxidant activities.

  14. Proportional counter end effects eliminator

    International Nuclear Information System (INIS)

    Meekins, J.F.

    1976-01-01

    An improved gas-filled proportional counter which includes a resistor network connected between the anode and cathode at the ends of the counter in order to eliminate ''end effects'' is described. 3 Claims, 2 Drawing Figures

  15. Over-the-Counter Medicines

    Science.gov (United States)

    Over-the-counter (OTC) medicines are drugs you can buy without a prescription. Some OTC medicines relieve aches, pains and itches. ... medicine is safe enough to sell over-the-counter. Taking OTC medicines still has risks. Some interact ...

  16. Fundamentals of gas counters

    International Nuclear Information System (INIS)

    Bateman, J.E.

    1994-01-01

    The operation of gas counters used for detecting radiation is explained in terms of the four fundamental physical processes which govern their operation. These are 1) conversion of neutral radiation into charged particles, 2) ionization of the host gas by a fast charge particle 3) transport of the gas ions to the electrodes and 4) amplification of the electrons in a region of enhanced electric field. Practical implications of these are illustrated. (UK)

  17. Count rate effect in proportional counters

    International Nuclear Information System (INIS)

    Bednarek, B.

    1980-01-01

    A new concept is presented explaining changes in spectrometric parameters of proportional counters which occur due to varying count rate. The basic feature of this concept is that the gas gain of the counter remains constant in a wide range of count rate and that the decrease in the pulse amplitude and the detorioration of the energy resolution observed are the results of changes in the shape of original current pulses generated in the active volume of the counter. In order to confirm the validity of this statement, measurements of the gas amplification factor have been made in a wide count rate range. It is shown that above a certain critical value the gas gain depends on both the operating voltage and the count rate. (author)

  18. Influence of tube volume on measurement uncertainty of GM counters

    Directory of Open Access Journals (Sweden)

    Stanković Koviljka Đ.

    2010-01-01

    Full Text Available GM counters are often used in radiation detection since they generate a strong signal which can be easily detected. The working principal of a GM counter is based on the interaction of ionizing radiation with the atoms and molecules of the gas present in the counter's tube. Free electrons created as a result of this interaction become initial electrons, i. e. start an avalanche process which is detected as a pulse of current. This current pulse is independent of the energy imparted on the gas, that being the main difference between a GM counter and the majority of other radiation detectors. In literature, the dependence on the incidence of radiation energy, tube's orientation and characteristics of the reading system are quoted as the main sources of measurement uncertainty of GM counters. The aim of this paper is to determine the dependence of measurement uncertainty of a GM counter on the volume of its counter's tube. The dependence of the pulse current on the size of the counter's tube has, therefore, been considered here, both in radial and parallel geometry. The initiation and expansion of the current pulse have been examined by means of elementary processes of electrical discharge such as the Markov processes, while the changes in the counter's tube volume were put to test by the space - time enlargement law. The random variable known as the 'current pulse in the counter's tube' (i. e. electrical breakdown of the electrode configuration has also been taken into account and an appropriate theoretical distribution statistically determined. Thus obtained theoretical results were then compared to corresponding experimental results established in controlled laboratory conditions.

  19. Separation of patuletin-3-O-glucoside, astragalin, quercetin, kaempferol and isorhamnetin from Flaveria bidentis (L.) Kuntze by elution-pump-out high-performance counter-current chromatography.

    Science.gov (United States)

    Wei, Yun; Xie, Qianqian; Fisher, Derek; Sutherland, Ian A

    2011-09-09

    Flaveria bidentis (L.) Kuntze is an annual alien weed of Flaveria Juss. (Asteraceae) in China. Bioactive compounds, mainly flavonol glycosides and flavones from F. bidentis (L.) Kuntze, have been studied in order to utilize this invasive weed, Analytical high-performance counter-current chromatography (HPCCC) was successfully used to separate patuletin-3-O-glucoside, a mixture of hyperoside (quercetin-3-O-galactoside) and 6-methoxykaempferol-3-O-galactoside, astragalin, quercetin, kaempferol and isorhamnetin using two runs with different solvent system. Ethyl acetate-methanol-water (10:1:10, v/v) was selected by analytical HPCCC as the optimum phase system for the separation of patuletin-3-O-glucoside, a mixture of hyperoside and 6-methoxykaempferol-3-O-galactoside, and astragalin. A Dichloromethane-methanol-water (5:3:2, v/v) was used for the separation of quercetin, kaempferol and isorhamnetin. The separation was then scaled up: the crude extract (ca 1.5 g) was separated by preparative HPCCC, yielding 12 mg of patuletin-3-O-glucoside at a purity of 98.3%, yielding 9 mg of a mixture of hyperoside and 6-methoxykaempferol-3-O-galactoside constituting over 98% of the fraction, and 16 mg of astragalin (kaempferol-3-O-glucoside) at a purity of over 99%. The pump-out peaks are isorhanetin (98% purity), kaemferol (93% purity) and quercitin (99% purity). The chemical structure of patuletin-3-O-glucoside and astragalin were confirmed by MS and ¹H, ¹³C NMR. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. High-speed counter-current chromatography coupled online to high performance liquid chromatography-diode array detector-mass spectrometry for purification, analysis and identification of target compounds from natural products.

    Science.gov (United States)

    Liang, Xuejuan; Zhang, Yuping; Chen, Wei; Cai, Ping; Zhang, Shuihan; Chen, Xiaoqin; Shi, Shuyun

    2015-03-13

    A challenge in coupling high-speed counter-current chromatography (HSCCC) online with high performance liquid chromatography (HPLC) for purity analysis was their time incompatibility. Consequently, HSCCC-HPLC was conducted by either controlling HPLC analysis time and HSCCC flow rate or using stop-and-go scheme. For natural products containing compounds with a wide range of polarities, the former would optimize experimental conditions, while the latter required more time. Here, a novel HSCCC-HPLC-diode array detector-mass spectrometry (HSCCC-HPLC-DAD-MS) was developed for undisrupted purification, analysis and identification of multi-compounds from natural products. Two six-port injection valves and a six-port switching valve were used as interface for collecting key HSCCC effluents alternatively for HPLC-DAD-MS analysis and identification. The ethyl acetate extract of Malus doumeri was performed on the hyphenated system to verify its efficacy. Five main flavonoids, 3-hydroxyphloridzin (1), phloridzin (2), 4',6'-dihydroxyhydrochalcone-2'-O-β-D-glucopyranoside (3, first found in M. doumeri), phloretin (4), and chrysin (5), were purified with purities over 99% by extrusion elution and/or stepwise elution mode in two-step HSCCC, and 25mM ammonium acetate solution was selected instead of water to depress emulsification in the first HSCCC. The online system shortened manipulation time largely compared with off-line analysis procedure and stop-and-go scheme. The results indicated that the present method could serve as a simple, rapid and effective way to achieve target compounds with high purity from natural products. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Electromagnetic shower counter

    CERN Multimedia

    CERN PhotoLab

    1974-01-01

    The octogonal block of lead glass is observed by eight photomultiplier tubes. Four or five such counters, arranged in succession, are used on each arm of the bispectrometer in order to detect heavy particles of the same family as those recently observed at Brookhaven and SLAC. They provide a means of identifying electrons. The arrangement of eight lateral photomultiplier tubes offers an efficient means of collecting the photons produced in the showers and determining, with a high resolution, the energy of the incident electrons. The total width at half-height is less than 6.9% for electrons having an energy of 1 GeV.

  2. Preparative separation and identification of novel subsidiary colors of the color additive D&C Red No. 33 (Acid Red 33) using spiral high-speed counter-current chromatography.

    Science.gov (United States)

    Weisz, Adrian; Ridge, Clark D; Mazzola, Eugene P; Ito, Yoichiro

    2015-02-06

    Three low-level subsidiary color impurities (A, B, and C) often present in batches of the color additive D&C Red No. 33 (R33, Acid Red 33, Colour Index No. 17200) were separated from a portion of R33 by spiral high-speed counter-current chromatography (HSCCC). The separation involved use of a very polar solvent system, 1-BuOH/5mM aq. (NH4)2SO4. Addition of ammonium sulfate to the lower phase forced partition of the components into the upper phase, thereby eliminating the need to add a hydrophobic counterion as was previously required for separations of components from sulfonated dyes. The very polar solvent system used would not have been retained in a conventional multi-layer coil HSCCC instrument, but the spiral configuration enabled retention of the stationary phase, and thus, the separation was possible. A 1g portion of R33 enriched in A, B, and C was separated using the upper phase of the solvent system as the mobile phase. The retention of the stationary phase was 38.1%, and the separation resulted in 4.8 mg of A of >90% purity, 18.3mg of B of >85% purity, and 91 mg of C of 65-72% purity. A second separation of a portion of the C mixture resulted in 7 mg of C of >94% purity. The separated impurities were identified by high-resolution mass spectrometry and NMR spectroscopic techniques as follows: 5-amino-3-biphenyl-3-ylazo-4-hydroxy-naphthalene-2,7-disulfonic acid, A; 5-amino-4-hydroxy-6-phenyl-3-phenylazo-naphthalene-2,7-disulfonic acid, B; and 5-amino-4-hydroxy-3,6-bis-phenylazo-naphthalene-2,7-disulfonic acid, C. The isomers A and B are compounds reported for the first time. Application of the spiral HSCCC method resulted in the additional benefit of yielding 930 mg of the main component of R33, 5-amino-4-hydroxy-3-phenylazo-naphthalene-2,7-disulfonic acid, of >97% purity. Published by Elsevier B.V.

  3. Design of a coil satellite centrifuge and its performance on counter-current chromatographic separation of 4-methylumbelliferyl sugar derivatives with polar organic-aqueous two-phase solvent systems.

    Science.gov (United States)

    Shinomiya, Kazufusa; Tokura, Koji; Kimura, Emiru; Takai, Midori; Harikai, Naoki; Yoshida, Kazunori; Yanagidaira, Kazuhiro; Ito, Yoichiro

    2015-05-01

    A new high-speed counter-current chromatograph, named coil satellite centrifuge (CSC), was designed and fabricated in our laboratory. The CSC apparatus produces the satellite motion such that the coiled column simultaneously rotates around the sun axis (the angular velocity, ω1), the planet axis (ω2) and the satellite axis (the central axis of the column) (ω3). In order to achieve this triplicate rotary motion without twisting of the flow tube, the rotation of each axis was determined by the following formula: ω1=ω2+ω3. This relation enabled to lay out the flow tube without twisting by the simultaneous rotation of three axes. The flow tube was introduced from the bottom side of the apparatus into the sun axis of the first rotary frame reaching the upper side of the planet axis and connected to the column in the satellite axis. The performance of the apparatus was examined on separation of 4-methylumbelliferyl (MU) sugar derivatives as test samples with organic-aqueous two-phase solvent systems composed of ethyl acetate/1-butanol/water (3:2:5, v/v) for lower phase mobile and (1:4:5, v/v) for upper phase mobile. With lower phase mobile, five 4-MU sugar derivatives including β-D-cellobioside (Cel), β-D-glucopyranoside, α-D-mannopyranoside, β-D-fucopyranoside and α-L-fucopyranoside (α-L-Fuc) were separated with the combined rotation around each axis at counterclockwise (CCW) (ω1) - CCW (ω2) - CCW (ω3) by the flow tube distribution. With upper phase mobile, three 4-MU sugar derivatives including α-L-Fuc, β-D-galactopyranoside and Cel were separated with the combined rotation around each axis at clockwise (CW) (ω1) - CW (ω2) - CW (ω3) by the flow tube distribution. A series of experiments on peak resolution and stationary phase retention revealed that better partition efficiencies were obtained at the flow rate of 0.5 mL/min (column 1) and 0.8 mL/min (column 2) for lower phase mobile and 0.2 mL/min (column 1) and 0.4 mL/min (column 2) for upper phase

  4. Development of a new extraction method based on counter current salting-out homogenous liquid-liquid extraction followed by dispersive liquid-liquid microextraction: Application for the extraction and preconcentration of widely used pesticides from fruit juices.

    Science.gov (United States)

    Farajzadeh, Mir Ali; Feriduni, Behruz; Mogaddam, Mohammad Reza Afshar

    2016-01-01

    In this paper, a new extraction method based on counter current salting-out homogenous liquid-liquid extraction (CCSHLLE) followed by dispersive liquid-liquid microextraction (DLLME) has been developed for the extraction and preconcentration of widely used pesticides in fruit juice samples prior to their analysis by gas chromatography-flame ionization detection (GC-FID). In this method, initially, sodium chloride as a separation reagent is filled into a small column and a mixture of water (or fruit juice) and acetonitrile is passed through the column. By passing the mixture sodium chloride is dissolved and the fine droplets of acetonitrile are formed due to salting-out effect. The produced droplets go up through the remained mixture and collect as a separated layer. Then, the collected organic phase (acetonitrile) is removed with a syringe and mixed with 1,1,2,2-tetrachloroethane (extraction solvent at µL level). In the second step, for further enrichment of the analytes the above mixture is injected into 5 mL de-ionized water placed in a test tube with conical bottom in order to dissolve acetonitrile into water and to achieve a sedimented phase at µL-level volume containing the enriched analytes. Under the optimal extraction conditions (extraction solvent, 1.5 mL acetonitrile; pH, 7; flow rate, 0.5 mL min(-1); preconcentration solvent, 20 µL 1,1,2,2-tetrachloroethane; NaCl concentration; 5%, w/w; and centrifugation rate and time, 5000 rpm and 5 min, respectively), the extraction recoveries and enrichment factors ranged from 87% to 96% and 544 to 600, respectively. Repeatability of the proposed method, expressed as relative standard deviations, ranged from 2% to 6% for intra-day (n=6, C=250 or 500 µg L(-1)) and inter-days (n=4, C=250 or 500 µg L(-1)) precisions. Limits of detection are obtained between 2 and 12 µg L(-1). Finally, the proposed method is applied for the determination of the target pesticide residues in the juice samples. Copyright © 2015

  5. A nuclear proportional counter

    International Nuclear Information System (INIS)

    1973-01-01

    The invention relates to a nuclear proportional counter comprising in a bulb filled with a low-pressure gas, a wire forming an anode and a cathode, characterized in that said cathode is constituted by two plane plates parallel to each other and to the anode wire, and in that two branches of a circuit are connected to the anode wire end-portions, each branch comprising a pre-amplifier, a measuring circuit consisting of a differentiator-integrator-differentiator amplifier and a zero detector, one of the branches comprising an adjustable delay circuit, both branches jointly attacking a conversion circuit for converting the pulse duration into amplitudes said conversion circuit being followed by a multi-channel analyzer, contingently provided with a recorder [fr

  6. Silica aerogel Cerenkov counter

    International Nuclear Information System (INIS)

    Yasumi, S.; Masaike, A.; Yamamoto, A.; Yoshimura, Y.; Kawai, H.

    1984-03-01

    In order to obtain silica aerogel radiators of good quality, the prescription used by Saclay group has been developed. We have done several experiments using beams from KEK.PS to test the performance of a Cerenkov counter with aerogel modules produced in KEK. It turned out that these modules had excellent quality. The production rate of silica aerogel in KEK is 15 -- 20 litres a week. Silica aerogel modules of 20 x 10 x 3 cm 3 having the refractive index of 1.058 are successfully being used by Kyoto University group in the KEK experiment E92 (Σ). Methodes to produce silica aerogel with higher refractive index than 1.06 has been investigated both by heating an module with the refractive index of 1.06 and by hydrolyzing tetraethyl silicate. (author)

  7. Scintillation counter, segmented shield

    International Nuclear Information System (INIS)

    Olson, R.E.; Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  8. Micropipette as Coulter counter for submicron particles

    Science.gov (United States)

    Rudzevich, Yauheni; Ordonez, Tony; Evans, Grant; Chow, Lee

    2011-03-01

    Coulter counter based on micropipette has been around for several decades. Typical commercial Coulter counter has a pore size of 20 μ m, and is designed to detect micron-size blood cells. In recent years, there are a lot of interests in using nanometer pore size Coulter counter to detect single molecule and to sequence DNA. Here we describe a simple nanoparticle counter based on pulled micropipettes with a diameter of 50 -- 500 nm. Borosilicate micropipettes with an initial outer diameter of 1.00 mm and inner diameter of 0.5 mm are used. After pulling, the micropipettes are fire polished and ultrasound cleaned. Chlorinated Ag/AgCl electrodes and 0.1 M of KCl solution are used. The ionic currents are measured using an Axopatch 200B amplifier in the voltage-clamp mode. Several types and sizes of nanoparticles are measured, including plain silica and polystyrene nanospheres. The results will be discussed in terms of pH values of the solution and concentrations of the nanoparticles. Financial support from National Science Foundation (NSF-0901361) is acknowledged.

  9. Space and power efficient hybrid counters array

    Science.gov (United States)

    Gara, Alan G [Mount Kisco, NY; Salapura, Valentina [Chappaqua, NY

    2009-05-12

    A hybrid counter array device for counting events. The hybrid counter array includes a first counter portion comprising N counter devices, each counter device for receiving signals representing occurrences of events from an event source and providing a first count value corresponding to a lower order bits of the hybrid counter array. The hybrid counter array includes a second counter portion comprising a memory array device having N addressable memory locations in correspondence with the N counter devices, each addressable memory location for storing a second count value representing higher order bits of the hybrid counter array. A control device monitors each of the N counter devices of the first counter portion and initiates updating a value of a corresponding second count value stored at the corresponding addressable memory location in the second counter portion. Thus, a combination of the first and second count values provide an instantaneous measure of number of events received.

  10. Permanently calibrated interpolating time counter

    International Nuclear Information System (INIS)

    Jachna, Z; Szplet, R; Kwiatkowski, P; Różyc, K

    2015-01-01

    We propose a new architecture of an integrated time interval counter that provides its permanent calibration in the background. Time interval measurement and the calibration procedure are based on the use of a two-stage interpolation method and parallel processing of measurement and calibration data. The parallel processing is achieved by a doubling of two-stage interpolators in measurement channels of the counter, and by an appropriate extension of control logic. Such modification allows the updating of transfer characteristics of interpolators without the need to break a theoretically infinite measurement session. We describe the principle of permanent calibration, its implementation and influence on the quality of the counter. The precision of the presented counter is kept at a constant level (below 20 ps) despite significant changes in the ambient temperature (from −10 to 60 °C), which can cause a sevenfold decrease in the precision of the counter with a traditional calibration procedure. (paper)

  11. A portable neutron coincidence counter

    Energy Technology Data Exchange (ETDEWEB)

    Peurrung, A.J.; Bowyer, S.M.; Craig, R.A.; Dudder, G.B.; Knopf, M.A.; Panisko, M.E.; Reeder, P.L.; Stromswold, D.C.; Sunberg, D.S.

    1996-11-01

    Pacific Northwest National Laboratory has designed and constructed a prototype portable neutron coincidence counter intended for use in a variety of applications, such as the verification and inspection of weapons components, safety measurements for novel and challenging situations, portable portal deployment to prevent the transportation of fissile materials, uranium enrichment measurements in hard-to-reach locations, waste assays for objects that cannot be measured by existing measurement systems, and decontamination and decommissioning. The counting system weighs less than 40 kg and is composed of parts each weighing no more than 5 kg. In addition, the counter`s design is sufficiently flexible to allow rapid, reliable assembly around containers of nearly arbitrary size and shape. The counter is able to discern the presence of 1 kg of weapons-grade plutonium within an ALR-8 (30-gal drum) in roughly 100 seconds and 10 g in roughly 1000 seconds. The counter`s electronics are also designed for maximum adaptability, allowing operation under a wide variety of circumstances, including exposure to gamma-ray fields of 1 R/h. This report provides a detailed review of the design and construction process. Finally, preliminary experimental measurements that confirm the performance capabilities of this counter are discussed. 6 refs., 18 figs., 3 tabs.

  12. Design of a novel coil satellite centrifuge and its performance on counter-current chromatographic separation of 4-methylumbelliferyl sugar derivatives with organic-aqueous two-phase solvent systems

    Science.gov (United States)

    Shinomiya, Kazufusa; Tokura, Koji; Kimura, Emiru; Takai, Midori; Harikai, Naoki; Yoshida, Kazunori; Yanagidaira, Kazuhiro; Ito, Yoichiro

    2015-01-01

    A new high-speed counter-current chromatograph, named coil satellite centrifuge (CSC), was designed and fabricated in our laboratory. The CSC apparatus produces the satellite motion such that the coiled column simultaneously rotates around the sun axis (the angular velocity, ω1), the planet axis (ω2) and the satellite axis (the central axis of the column) (ω3). In order to achieve this triplicate rotary motion without twisting of the flow tube, the rotation of each axis was determined by the following formula: ω1 = ω2 + ω3. This relation enabled to lay out the flow tube by two different ways, the SS type and the JS type. In the SS type, the flow tube was introduced from the upper side of the apparatus into the sun axis of the first rotary frame and connected to the planet axis of the second rotary frame like a double letter SS. In the JS type, the flow tube was introduced from the bottom of the apparatus into the sun axis reaching the upper side of the planet axis an inversed letter J, followed by distribution as in the SS type. The performance of the apparatus was examined on separation of 4-methylumbelliferyl (MU) sugar derivatives as test samples with organic-aqueous two-phase solvent systems composed of ethyl acetate/1-butanol/water (3 : 2 : 5, v/v) for lower phase mobile and (1 : 4 : 5, v/v) for upper phase mobile. With lower phase mobile, five 4-MU sugar derivatives including β-D-cellobioside (Cel), β-D-glucopyranoside, α-D-mannopyranoside, β-D-fucopyranoside and α-L-fucopyranoside (α-L-Fuc) were separated with the combined rotation around each axis at counterclockwise (CCW) (ω1) – CCW (ω2) – CCW (ω3) by the JS type flow tube distribution. With upper phase mobile, three 4-MU sugar derivatives including α-L-Fuc, β-D-galactopyranoside and Cel were separated with the combined rotation around each axis at clockwise (CW) (ω1) – CW (ω2) – CW (ω3) by the JS type flow tube distribution. A series of experiments on peak resolution and

  13. Multiple channel programmable coincidence counter

    Science.gov (United States)

    Arnone, Gaetano J.

    1990-01-01

    A programmable digital coincidence counter having multiple channels and featuring minimal dead time. Neutron detectors supply electrical pulses to a synchronizing circuit which in turn inputs derandomized pulses to an adding circuit. A random access memory circuit connected as a programmable length shift register receives and shifts the sum of the pulses, and outputs to a serializer. A counter is input by the adding circuit and downcounted by the seralizer, one pulse at a time. The decoded contents of the counter after each decrement is output to scalers.

  14. What is Counter-Enlightenment?

    OpenAIRE

    Darrin M. McMahon

    2017-01-01

    This article counters recent suggestions that there was no such thing as a “Counter-Enlightenment” or “Counter-Enlightenments,” and that such terms ought thus to be abandoned.   While acknowledging inevitable difficulties with the terms, the article argues that there can be no doubting the reality.   European countries faced a variety of vehement and self-conscious movements that defined themselves precisely through their opposition to what they took to be the corrosive effects of the Enlight...

  15. In-vivo radiation counter

    International Nuclear Information System (INIS)

    Pollard, D.E.

    1983-01-01

    This patent specification describes a radiation counter utilizing at least one detector for sensing radiation from a living body. The radiation counter also includes an aperture for forming a corridor between the body and the detector. A shield outside the corridor prevents passage of background radiation through the corridor and gaining access to the detector. The counter also includes a device for isolating a selected portion of the body from the corridor such that radiation counting is restricted to a region of the body through a separate detector. The corridor formation permits a user to stand in an upright position while the detector and detectors are able to separately monitor different sections of the body. The radiation counter overcomes the problem of obtaining accurate and quick measurements or radiation doses sustained by a large group of persons. (author)

  16. High-speed parallel counter

    International Nuclear Information System (INIS)

    Gus'kov, B.N.; Kalinnikov, V.A.; Krastev, V.R.; Maksimov, A.N.; Nikityuk, N.M.

    1985-01-01

    This paper describes a high-speed parallel counter that contains 31 inputs and 15 outputs and is implemented by integrated circuits of series 500. The counter is designed for fast sampling of events according to the number of particles that pass simultaneously through the hodoscopic plane of the detector. The minimum delay of the output signals relative to the input is 43 nsec. The duration of the output signals can be varied from 75 to 120 nsec

  17. Channel coincidence counter: version 1

    International Nuclear Information System (INIS)

    Krick, M.S.; Menlove, H.O.

    1980-06-01

    A thermal neutron coincidence counter has been designed for the assay of fast critical assembly fuel drawers and plutonium-bearing fuel rods. The principal feature of the detector is a 7-cm by 7-cm by 97-cm detector channel, which provides a uniform neutron detection efficiency of 16% along the central 40 cm of the channel. The electronics system is identical to that used for the High-Level Neutron Coincidence Counter

  18. Mathematic modulation of a simulation program for a coal and wood counter-current moving bed gasifier, which includes pyrolysis and drying processes and processes alternatives; Modelagem matematica e simulacao em computador de gaseificador de leito fixo contra-corrente para carvoes e biomassa com inclusao de processos de pirolise, secagem e alternativas do processo

    Energy Technology Data Exchange (ETDEWEB)

    Souza Santos, M.L. de [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

    1985-12-31

    A new version of a simulation program for coal and wood counter-current fixed bed gasifier has been completed and provides: all the principal information variables of the process throughout the bed as mass flow and composition for 13 gases and 6 solids, temperature of the gas and solid phases, reaction rates of combustion, gasification, pyrolysis and drying processes; composition, mass flow, temperature, combustion enthalpy and other produced gases physical and chemical properties; possibility of process alternatives analysis as volatiles recycling in order to eliminate tar, double withdrawn of gases and combinations. Comparisons between simulation and experimental results are presented. (author). 26 refs., 1 tab

  19. What is Counter-Enlightenment?

    Directory of Open Access Journals (Sweden)

    Darrin M. McMahon

    2017-02-01

    Full Text Available This article counters recent suggestions that there was no such thing as a “Counter-Enlightenment” or “Counter-Enlightenments,” and that such terms ought thus to be abandoned.   While acknowledging inevitable difficulties with the terms, the article argues that there can be no doubting the reality.   European countries faced a variety of vehement and self-conscious movements that defined themselves precisely through their opposition to what they took to be the corrosive effects of the Enlightenment.  In the process, they defined the main terms of an enduring vision of the world that we now associate with the Right.

  20. Plea and counter-plea

    International Nuclear Information System (INIS)

    1979-06-01

    The bulk of papers written during the hearing 'Plea and counter-plea', the so-called 'Gorleben hearing', which was held from 28th March until 3rd April 1979, comprises ca. 4,200 pages. It consists of the written comments put forward by the critics of nuclear energy, the minutes of the hearing as well as the supplementary statements of the counter-critics. This report is trying to confront those essential objections made by the critics which put in doubt the feasibility of a fuel-cycle centre with regard to safety engineering with the facts which are considered correct from the view of the DWK. The oral and written explanations of the counter-critics are particularly referred to in this debate. (orig./HP) [de

  1. Countering Russian Active Measures

    Science.gov (United States)

    2018-04-16

    information laundering has proven effective in several occasions.20 In 2016, Russian social media actors circulated a fake news story about the...Soviet Union, individuals in positions of power funneled communist party financial resources to off-shore bank accounts and later used this money to...international offshore banking industry, they [the current oligarchs] stole money that belonged to the Russian state, took it abroad for safety

  2. Over the Counter Culture

    OpenAIRE

    Jackson, Deborah

    2014-01-01

    A group exhibition which brings together 8 contemporary scottish artists to explore scottish identity and culture during the referendum period.\\ud \\ud My Contribution: "Real Life and How to Live it in Pangea. A large scale installation with video, free posters and postcards articulating the idea where the supercontinent Pangea (250 million years ago) and Pangea Ultima (in 250 million years time) stand for periods of Global hope and continuity exploring the idea that that the current stormy wo...

  3. Portable counter for geological research

    Energy Technology Data Exchange (ETDEWEB)

    Russell, O J

    1949-05-01

    A portable counter which has been developed for prospecting for radio-active uranium and thorium minerals, for general geological investigations, and as an ultra-sensitive detector of lost or mislaid radium, is described. The aforementioned general usage includes the identification of changes in strata by means of the investigation of the slight amount of residual activity pressent in most minerals. The apparatus, which consists essentially of a scaled-down version of a standard laboratory Geiger-Muller counter, is highly sensitive since a variation equivalent to 4% of the cosmic ray background can be detected by a three-minute count.

  4. ''Conventional'' Cerenkov counters at ISABELLE

    International Nuclear Information System (INIS)

    Foley, K.J.

    1977-01-01

    Cherenkov counters to be used with ISABELLE are described. The three counters used in the Hadron Spectrometer can be used to identify particles in the range 10 to 40 GeV/c with pions separated from heavier particles down to approximately 3 GeV/c. A longer spectrometer for 400 x 400 GeV operation should also be used. The spectrometers may be used with CO 2 and H 2 . The range of particle identification of 8 to 60 GeV/c with pions separated from heavier particles down to approximately 5 GeV/c is possible

  5. The Eros of Counter Education

    Science.gov (United States)

    Luzon, Pinhas

    2016-01-01

    Erotic Counter Education (ECE) is the educational position of the late Ilan Gur-Ze'ev. In ECE Gur-Ze'ev combines two opposing positions in the philosophy of education, one teleological and anti-utopian, the other teleological and utopian. In light of this unique combination, I ask what mediates between these two poles and suggest that the answer…

  6. Dimensions of Counter-Narratives

    DEFF Research Database (Denmark)

    2019-01-01

    The book welcomes proposals for chapter contributions on a wide array of topics related to the narratological notion of counter-narratives. By way of example, the topic has hitherto been treated by disciplines and subjects such as literature studies, organization studies, corporate communication...

  7. Countering 21st Century Threats

    DEFF Research Database (Denmark)

    Scharling Pedersen, Peter; Pillai, Chad M.; Hun, Lee Jae

    2015-01-01

    ), Counter-Terrorism (CT), and Security and Stability Operations (SSO). • Establishing a construct that allows a strategic Whole-of-Government capacity for operations coordinated by joint interagency task forces. • Continue to developing the Global SOF network. • Increased intelligence sharing in areas...

  8. The Micro Trench Gas Counter

    International Nuclear Information System (INIS)

    Schmitz, J.

    1991-07-01

    A novel design is presented for a gas avalanche chamber with micro-strip gas readout. While existing gaseous microstrip detectors (Micro-strip Gas Counters, Knife edge chambers) have a minimum anode pitch of the order of 100 μm, the pitch of the discussed Micro Trench Gas Counter goes down to 30-50 μm. This leads to a better position resolution and two track separation, and a higher radiation resistivity. Its efficiency and signal speed are expected to be the same as the Microstrip Gas Counter. The energy resolution of the device is expected to be equal to or better than 10 percent for the 55 Fe peak. Since the anode strip dimensions are larger than those in a MSGC, the device may be not as sensitive to discharges and mechanical damage. In this report production of the device is briefly described, and predictions on its operation are made based on electric field calculations and experience with the Microstrip Gas Counter. The authors restrict themselves to the application in High Energy Physics. (author). 10 refs.; 9 figs

  9. Basic Research Needs for Countering Terrorism

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, W.; Michalske, T.; Trewhella, J.; Makowski, L.; Swanson, B.; Colson, S.; Hazen, T.; Roberto, F.; Franz, D.; Resnick, G.; Jacobson, S.; Valdez, J.; Gourley, P.; Tadros, M.; Sigman, M.; Sailor, M.; Ramsey, M.; Smith, B.; Shea, K.; Hrbek, J.; Rodacy, P.; Tevault, D.; Edelstein, N.; Beitz, J.; Burns, C.; Choppin, G.; Clark, S.; Dietz, M.; Rogers, R.; Traina, S.; Baldwin, D.; Thurnauer, M.; Hall, G.; Newman, L.; Miller, D.; Kung, H.; Parkin, D.; Shuh, D.; Shaw, H.; Terminello, L.; Meisel, D.; Blake, D.; Buchanan, M.; Roberto, J.; Colson, S.; Carling, R.; Samara, G.; Sasaki, D.; Pianetta, P.; Faison, B.; Thomassen, D.; Fryberger, T.; Kiernan, G.; Kreisler, M.; Morgan, L.; Hicks, J.; Dehmer, J.; Kerr, L.; Smith, B.; Mays, J.; Clark, S.

    2002-03-01

    To identify connections between technology needs for countering terrorism and underlying science issues and to recommend investment strategies to increase the impact of basic research on efforts to counter terrorism.

  10. An introduction to automatic radioactive sample counters

    International Nuclear Information System (INIS)

    1980-01-01

    The subject is covered in chapters, entitled; the detection of radiation in sample counters; nucleonic equipment; liquid scintillation counting; basic features of automatic sample counters; statistics of counting; data analysis; purchase, installation, calibration and maintenance of automatic sample counters. (U.K.)

  11. Counter-discourse in Zimbabwean literature

    NARCIS (Netherlands)

    Mangena, Tendai

    2015-01-01

    Counter-Discourse in Zimbabwean Literature is a study of specific aspects of counter-discursive Zimbabwean narratives in English. In discussing the selected texts, my thesis is based on Terdiman’s (1989) the postcolonial concept of counter-discourse. In Zimbabwean literature challenges to a dominant

  12. BIOLOGICAL TERRORISM: THE NOTION, ESSENCE AND MAIN AREAS OF COUNTER

    Directory of Open Access Journals (Sweden)

    Julia Sarankina

    2016-10-01

    Full Text Available The article issued theoretical and practice problems of combating terrorism in current conditions, in particular, analyzes the concept of bio-terrorism as a form of terrorism, we investigate its nature, characteristics, and also referred to the major directions of countering.

  13. Radar observation of the equatorial counter-electrojet

    International Nuclear Information System (INIS)

    Hanuise, C.; Crochet, M.; Gouin, P.; Ogubazghi, Ghebrebrhan

    1979-01-01

    Electron drift velocity in the equatorial electrojet has been measured for a few years by coherent radar techniques in Africa. For the first time such measurements were performed during a strong reversal of the ionospheric current dubbed 'counter-electrojet'. These observations agree with the theories of the plasma instabilities at the origin of the electron density irregularities giving the radar echoes

  14. Discharge quenching circuit for counters

    International Nuclear Information System (INIS)

    Karasik, A.S.

    1982-01-01

    A circuit for quenching discharges in gas-discharge detectors with working voltage of 3-5 kV based on transistors operating in the avalanche mode is described. The quenching circuit consists of a coordinating emitter follower, amplifier-shaper for avalanche key cascade control which changes potential on the counter electrodes and a shaper of discharge quenching duration. The emitter follower is assembled according to a widely used flowsheet with two transistors. The circuit permits to obtain a rectangular quenching pulse with front of 100 ns and an amplitude of up to 3.2 kV at duration of 500 μm-8 ms. Application of the quenching circuit described permits to obtain countering characteristics with the slope less than or equal to 0.02%/V and plateau extent greater than or equal to 300 V [ru

  15. Counter support for WA35

    CERN Multimedia

    CERN PhotoLab

    1977-01-01

    This assembly was equipped with 78 counters, each consisting of a lucite cone, to produce Cerenkov light, and a CsI scintillator plate of 3 mm thickness glued on the face of the cone. The experiment WA35 was set-up in the s1 beam (West Hall) by the Darmstadt-Heidelberg-Virginia-Warsaw Collaboration to measure angular distributions and multiplicities of pions and recoil protons produced by hadrons interacting in nuclei. (See Annual Report 1976 p. 39)

  16. INTRODUCING OVER THE COUNTER COUNSELING

    Directory of Open Access Journals (Sweden)

    Nataša Bakić-Mirić

    2009-01-01

    Full Text Available A pharmacist in today’s world has a great responsibility – to help and educate patients about diverse ways for effective self-treatment. Whereas self-care is becoming increasingly popular among patients today the availability of over-the-counter medications makes it possible for patients to treat numerous conditions on their own but still under the supervision of a healthcare provider. During the pharmacist-patient encounter, the pharmacist’s obligation is to evaluate the patient’s medical condition, provide proper advice and counsel the patient on the proper course of treatment to be taken. Also by employing effective over the counter (OTC counseling as the most proper means in a pharmacist/patient communication process and, accordingly, rapport building in the OTC area, the pharmacist needs to demonstrate high energy, enthusiasm, respect, empathy, know-how of sensitive intercultural issues alongside personal appearance, body language, eye contact that all together make his/her personal “signature”. Accordingly, apart from patient education, the primary objective of OTC counseling becomes to educate pharmacists on basic principles used in assisting patients in the selection of over-the-counter (OTC products, provide examples of proper communication techniques for effective patient counseling concerning the OTC products (i.e. dosage, administration technique, storage, food and beverage interaction, monitoring etc where the pharmacist plays the key role in helping patients maximize their pharmaceutical care.

  17. Position-sensitive proportional counter

    International Nuclear Information System (INIS)

    Kopp, M.K.

    1980-01-01

    A position-sensitive proportional counter circuit uses a conventional (low-resistance, metal-wire anode) counter for spatial resolution of an ionizing event along the anode, which functions as an RC line. A pair of preamplifiers at the anode ends act as stabilized active-capacitance loads, each comprising a series-feedback, low-noise amplifier and a unity-gain, shunt-feedback amplifier whose output is connected through a feedback capacitor to the series-feedback amplifier input. The stabilized capacitance loading of the anode allows distributed RC-line position encoding and subsequent time difference decoding by sensing the difference in rise times of pulses at the anode ends where the difference is primarily in response to the distributed capacitance along the anode. This allows the use of lower resistance wire anodes for spatial radiation detection which simplifies the counter construction of handling of the anodes, and stabilizes the anode resistivity at high count rates (>10 6 counts/sec). (author)

  18. Silicon photomultipliers in AMIGA muon counters

    Energy Technology Data Exchange (ETDEWEB)

    Botti, Ana Martina [Institut fuer Kernphysik, Karlsruher Institut fuer Technologie (Germany); Instituto de Tecnologias en Deteccion y Astroparticulas (ITeDA) (Argentina); Collaboration: Pierre-Auger-Collaboration

    2016-07-01

    The project AMIGA (Auger Muons and Infill for the Ground Array) aims to extend the energy range at the Pierre Auger Observatory to observe cosmic rays of lower energies (down to ∝10{sup 17} eV) and to study the transition from extragalactic to galactic cosmic rays. AMIGA is compounded by an infill of surface detectors (employing Cherenkov radiation detection in water) and muon counters. The AMIGA muon counters consist of an array of buried modules composed of 64 scintillator bars, a multi-pixel Photo Multiplier Tube (PMT) and the corresponding electronic of acquisition which works along with the surface detector. Currently, ITeDA is evaluating the feasibility of replacing PMTs with silicon photomultipliers (SiPM) without performing any substantial modification in the digital readout nor in the mechanical design. I present calibration results of a prototype module associated to the surface detector Toune of the Pierre Auger Observatory using a SiPM Hamamatsu S1257-100C plugged to the standard AMIGA front-end electronics. In addition, a study concerning gain stability and temperature variation has also been performed and is reported. I finally discuss a comparison between traces measured by both photodetectors (PMT and SiPM) for modules associated to the surface detector Toune.

  19. Development of a low-cost whole body counter

    International Nuclear Information System (INIS)

    Smith, M.H.; Gross, G.P.

    1991-01-01

    This paper documents the construction and calibration of a whole-body counter for the Radiation Safety Office of the Mayo Clinic in Rochester, MN. Changes in the federal regulations may require improved documentation of internal dose for radiation workers. A relatively inexpensive and simple chair-type whole-body counter may suit the needs of many organizations for in vivo assessment of gamma emitting radionuclides. A simple calibration phantom and a spreadsheet computer program were developed in conjunction with the counter. The spreadsheet can be used to calculate an estimate of committed effective dose equivalent based on activity in a subject and data from ICRP Publication 30. Using a count time of 10 minutes, the counter's minimum detectable activity ranged from 370 Bq to 1,110 Bq for 60 Co and 57 Co respectively. Other institutions will be able to assemble whole-body counters at low cost, often from surplus components. The spreadsheet is easily adapted to the needs of any institution and uses current methodology to estimate internal dose

  20. Proportional counter system for radiation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, M; Okudera, S

    1970-11-21

    A gas such as Xe or Kr employed in counter tubes is charged into the counter tube of a gas-flow type proportional counter for radiation measurement and into a vessel having a volume larger than that of the counter tube. The vessel communicates with the counter tube to circulate the gas via a pump through both the vessel and tube during measurement. An organic film such as a polyester synthetic resin film is used for the window of the counter tube to measure X-rays in the long wavelength range. Accordingly, a wide range of X-rays can be measured including both long and short wavelengths ranges by utilizing only one counter tube, thus permitting the gases employed to be effectively used.

  1. Improvements to well scintillation counters

    International Nuclear Information System (INIS)

    Farukhi, M.R.; Mataraza, G.A.; Wimer, O.D.

    1977-01-01

    This invention relates to the field of ionising radiation detection. It concerns in particular scintillation detectors of the type that is commonly used in conjunction with a photomultiplier tube and that is used for monitoring radiation, for instance in the clinical measurements of isotopes. This invention enables well scintillation counters to be made, characterised by a high efficiency in measuring the thindown rate of radio-pharmaceutical solutions and to resolve the distribution of energy emanating from the radioactive source. It particularly consists in improving the uniformity of the luminous efficiency, the quality of the resolution and the efficiency whilst improving the reception of light [fr

  2. Scintillation counter based radiation dosimeter

    International Nuclear Information System (INIS)

    Shin, Jeong Hyun

    2009-02-01

    The average human exposure per year is about 240mrem which is come from Radon and human body and terrestrial and cosmic radiation and man-made source. Specially radiation exposure through air from environmental radiation sources is 80mrem/yr(= 0.01mR/hr) which come from Terrestrial and cosmic radiation. Radiation dose is defined as energy deposit/mass. There are two major methods to detect radiation. First method is the energy integration using Air equivalent material like GM counter wall material. Second method is the spectrum to dose conversion method using NaI(Tl), HPGe. These two methods are using generally to detect radiation. But these methods are expensive. So we need new radiation detection method. The research purpose is the development of economical environmental radiation dosimeter. This system consists of Plastic/Inorganic scintillator and Si photo-diode based detector and counting based circuitry. So count rate(cps) can be convert to air exposure rate(R/hr). There are three major advantages in this system. First advantages is no high voltage power supply like GM counter. Second advantage is simple electronics. Simple electronics system can be achieved by Air-equivalent scintillation detector with Al filter for the same detection efficiency vs E curve. From former two advantages, we can know the most important advantages of the this system. Third advantage is economical system. The price of typical GM counter is about $1000. But the price of our system is below $100 because of plastic scintillator and simple electronics. The role of scintillation material is emitting scintillation which is the flash of light produced in certain materials when they absorb ionizing radiation. Plastic scintillator is organic scintillator which is kind of hydrocarbons. The special point are cheap price, large size production(∼ton), moderate light output, fast light emission(ns). And the role of Al filter is equalizing counting efficiency of air and scintillator for

  3. Programmable spark counter of tracks

    International Nuclear Information System (INIS)

    Denisov, A.E.; Nikolaev, V.A.; Vorobjev, I.B.

    2005-01-01

    For the purpose, a new set-the programmable all-automatic spark counter AIST-4-has been developed and manufactured. Compared to our previous automated spark counter ISTRA, which was operated by the integrated fixed program, the new set is operated completely by a personal computer. The mechanism for pressing and pulling the aluminized foil is put into action by a step motor operated by a microcontroller. The step motor turns an axle. The axle has two eccentrics. One of them moves a pressing plate up and down. The second eccentric moves the aluminized foil by steps of ∼15mm after the end of each pulse counting. One turnover of the axle corresponds to one pulse count cycle. The step motor, the high-voltage block and the pulse count block are operated by the microcontroller PIC 16C84 (Microstar). The set can be operated either manually by keys on the front panel or by a PC using dialogue windows for radon or neutron measurements (for counting of alpha or fission fragment tracks). A number of algorithms are developed: the general procedures, the automatic stopping of the pulse counting, the calibration curve, determination of the count characteristics and elimination of the short circuit in a track

  4. A low-level needle counter

    International Nuclear Information System (INIS)

    Fujita, Y.; Taguchi, Y.; Imamura, M.; Inoue, T.; Tanaka, S.

    1977-01-01

    A small end-window type gas-flow counter which has a sharpened needle (anode) against the end-window plane (cathode) was developed for low-level counting of β particles to the amount of less than one count per hour in solid sources of relatively high specific activity. The advantage of the needle counter for low-level work is that being of a conical shape the active volume as against the window area is small. The background count rate of 0.0092+-0.0005 cpm was obtained for a 10 mm dia needle counter operating in GM mode and in anticoincidence with a well-type NaI(Tl) guard crystal with massive shields. The counter design and the counter characteristics are presented in detail. The needle counter is simple in design, low-cost and stable in long time operation. (author)

  5. Uraniferous minerals heap leaching process by counter techique

    International Nuclear Information System (INIS)

    Fuentes G, D.A.

    1978-01-01

    An experimental study was made at laboratory level with respect to a process for the treatment of an uranium ore by counter current acid heap leaching with maturity periods and washing. This mineral with an average grade of 0.24% of U 3 O 8 from the levels zero-fourty of the El Nopal uraniferous deposit, located in the Sierra of Pena Blanca, State of Chihuahua (Mexico). The process which is proposed consist of 4 consecutive stages: a) The prehumectation with a fertile solution of a 0.0034 g U 3 O 8 /1 and 3 g H 2 SO 4 /l concentration, b) The counter current acid attack, c) The maturity or hardening, d) The washing with current water. The relaton liquid-solid in the stages of prehumectation, acid attack, as well as washing stage was of 0.3 m 3 /t. The average efficiency was of 77% of recovered *uranium. (author)

  6. Counter Traction Makes Endoscopic Submucosal Dissection Easier

    OpenAIRE

    Oyama, Tsuneo

    2012-01-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable co...

  7. Crate counter for normal operating loss

    International Nuclear Information System (INIS)

    Harlan, R.A.

    A lithium-loaded zinc sulfide scintillation counter to closely assay plutonium in waste packaged in 1.3 by 1.3 by 2.13m crates was built. In addition to assays for normal operating loss accounting, the counter will allow safeguards verification immediately before shipment of the crates for burial. The counter should detect approximately 10 g of plutonium in 1000 kg of waste

  8. The 'miniskirt' counter array at CDF II

    International Nuclear Information System (INIS)

    Artikov, A.; Budagov, Yu.; Bellettini, G.

    2002-01-01

    Muon detection is fundamental to many of the interesting analyses at CDF II. For more efficient muon registration in Run II it was decided to increase geometrical coverage. The so-called 'miniskirt' counters are part of this upgrade. The original design parameters of the 'miniskirt' and mixed 'miniskirt' scintillation counters for the CDF Muon System are presented. The modifications, testing and installation of these counters within the CDF Upgrade Project are described in detail. The timing characteristics of mixed 'miniskirt' counters are also investigated using cosmic muons. The measurements show that the time resolution does not exceed 2.2 ns

  9. Value for Money? Problems of Impact Assessment of Counter-radicalization Policies on End Target Groups

    DEFF Research Database (Denmark)

    Lindekilde, Lasse

    2012-01-01

    There is a lack of consensus in the academic literature and among policy makers and practitioners on the definition of violent radicalisation, and current counter-radicalisation policy responses and procedures are informed by a weak and, at times, confused understanding of the motivational...... and structural factors underpinning such a process. The result is a variety of interventions across the EU, signalling a lack of consensus on the purposes of counter-radicalisation. In addition, indicators of success of counter-radicalisation policies are often unclear or unspecified. One consequence...... of this is that assessments of the effectiveness of counter-radicalisation measures and policy responses are either lacking or often methodologically questionable, impairing our understanding of the impacts of counter-radicalisation interventions on targeted communities. The article investigates problems of assessing...

  10. Numerical model of thyroid counter

    Directory of Open Access Journals (Sweden)

    Szuchta Maciej

    2016-03-01

    Full Text Available The aim of this study was to develop a numerical model of spectrometric thyroid counter, which is used for the measurements of internal contamination by in vivo method. The modeled detector is used for a routine internal exposure monitoring procedure in the Radiation Protection Measurements Laboratory of National Centre for Nuclear Research (NCBJ. This procedure may also be used for monitoring of occupationally exposed nuclear medicine personnel. The developed model was prepared using Monte Carlo code FLUKA 2011 ver. 2b.6 Apr-14 and FLAIR ver. 1.2-5 interface. It contains a scintillation NaI(Tl detector, the collimator and the thyroid water phantom with a reference source of iodine 131I. The geometry of the model was designed and a gamma energy spectrum of iodine 131I deposited in the detector was calculated.

  11. Evaluation of waste crate counter

    International Nuclear Information System (INIS)

    Wachter, J.R.; Shaw, S.W.

    1994-01-01

    A novel nondestructive measurement system has been developed to perform combined gamma-ray, passive neutron, and active neutron analyses of radioactive waste packaged in large crates. The system will be used to examine low level and transuranic waste at the Waste Receiving and Processing facility at Westinghouse-Hanford Corp. Prior to delivery of the system, an extensive evaluation of its performance characteristics will be conducted. The evaluation is to include an assessment of the mechanical properties of the system, gamma-ray attenuation correction algorithms, instrument response as a function of source positions, performance of the high resolution gamma-ray detector for ''hot spot'' and isotopic analyses, active and passive neutron counter response, instrument sensitivity, matrix effects, and packaging effects. This report will discuss the findings of the evaluation program, to date, and indicate future directions for the program

  12. Scintillation counter: photomultiplier tube alignment

    International Nuclear Information System (INIS)

    Olson, R.E.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into the sample receiving zone. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (auth)

  13. Scintillation counter, maximum gamma aspect

    International Nuclear Information System (INIS)

    Thumim, A.D.

    1975-01-01

    A scintillation counter, particularly for counting gamma ray photons, includes a massive lead radiation shield surrounding a sample-receiving zone. The shield is disassembleable into a plurality of segments to allow facile installation and removal of a photomultiplier tube assembly, the segments being so constructed as to prevent straight-line access of external radiation through the shield into radiation-responsive areas. Provisions are made for accurately aligning the photomultiplier tube with respect to one or more sample-transmitting bores extending through the shield to the sample receiving zone. A sample elevator, used in transporting samples into the zone, is designed to provide a maximum gamma-receiving aspect to maximize the gamma detecting efficiency. (U.S.)

  14. Counter terms for low momentum nucleon-nucleon interactions

    International Nuclear Information System (INIS)

    Holt, Jason D.; Kuo, T.T.S.; Brown, G.E.; Bogner, Scott K.

    2004-01-01

    There is much current interest in treating low energy nuclear physics using the renormalization group (RG) and effective field theory (EFT). Inspired by this RG-EFT approach, we study a low-momentum nucleon-nucleon (NN) interaction, V low-k , obtained by integrating out the fast modes down to the scale Λ∼2 fm -1 . Since NN experiments can only determine the effective interaction in this low momentum region, our chief purpose is to find such an interaction for complex nuclei whose typical momenta lie below this scale. In this paper we find that V low-k can be highly satisfactorily accounted for by the counter terms corresponding to a short range effective interaction. The coefficients C n of the power series expansion ΣC n q n for the counter terms have been accurately determined, and results derived from several meson-exchange NN interaction models are compared. The counter terms are found to be important only for the S, P and D partial waves. Scaling behavior of the counter terms is studied. Finally we discuss the use of these methods for computing shell model matrix elements

  15. The Analysis of the Relationship between Clean Technology Transfer and Chinese Intellectual Property Countering the Climate Changes

    DEFF Research Database (Denmark)

    Min, Hao

    This report discusses the relationship between the Chinese intellectual property systems which counter with the climate change and the transfer of clean technology, and states how to encourage the developed countries transfer the clean technology to the developing countries according to the relat...... property countering the climate changes; the analysis of current technology transfer modes relating to the climate; the difficulties of Chinese countering climate changes technology transfer and strategic thinking....

  16. Deterring Violent Extremism in America by Utilizing Good Counter-Radicalization Practices from Abroad: A Policy Perspective

    Science.gov (United States)

    2017-03-01

    counter-violent extremism, deterring violent extremism, counter-radicalization, country study, CVE, DVE, deterrence, policy perspective , good practices...both North America and in Europe, more constructive policies must be developed to manage diversity. There are serious flaws in the current policies...EXTREMISM IN AMERICA BY UTILIZING GOOD COUNTER-RADICALIZATION PRACTICES FROM ABROAD: A POLICY PERSPECTIVE by Amy Fires Bonanno March 2017

  17. On generating counter-rotating streamwise vortices

    KAUST Repository

    Winoto, S H

    2015-09-23

    Counter-rotating streamwise vortices are known to enhance the heat transfer rate from a surface and also to improve the aerodynamic performance of an aerofoil. In this paper, some methods to generate such counter-rotating vortices using different methods or physical conditions will be briefly considered and discussed.

  18. Charged particle identification: Cherenkov counters at ISABELLE

    International Nuclear Information System (INIS)

    Etkin, A.; Kostoulas, I.; Leith, D.W.G.S.; Thun, R.

    1977-01-01

    A brief summary is given of a study of Cherenkov counters for ISABELLE. The study was certainy not exhaustive and was meant primarily to suggest future detector development. A substantial research effort is needed in order to insure that Cherenkov counters utilizing photoionization are fully exploited

  19. Development of photocathodes for gas counters

    International Nuclear Information System (INIS)

    Chalot, J.F.

    1982-03-01

    A lot of ways of physics needs the development of high sensibility imaging devices with large sensitive surface. The problems brought by the building of such devices may be solved by the use of gaz counters. But we must sensitize these counters to low energy photons ( [fr

  20. On generating counter-rotating streamwise vortices

    KAUST Repository

    Winoto, S H; Mitsudharmadi, Hatsari; Budiman, A C; Hasheminejad, S M; Nadesan, T; Tandiono; Low, H T; Lee, T S

    2015-01-01

    Counter-rotating streamwise vortices are known to enhance the heat transfer rate from a surface and also to improve the aerodynamic performance of an aerofoil. In this paper, some methods to generate such counter-rotating vortices using different methods or physical conditions will be briefly considered and discussed.

  1. Counter traction makes endoscopic submucosal dissection easier.

    Science.gov (United States)

    Oyama, Tsuneo

    2012-11-01

    Poor counter traction and poor field of vision make endoscopic submucosal dissection (ESD) difficult. Good counter traction allows dissections to be performed more quickly and safely. Position change, which utilizes gravity, is the simplest method to create a clear field of vision. It is useful especially for esophageal and colon ESD. The second easiest method is clip with line method. Counter traction made by clip with line accomplishes the creation of a clear field of vision and suitable counter traction thereby making ESD more efficient and safe. The author published this method in 2002. The name ESD was not established in those days; the name cutting endoscopic mucosal resection (EMR) or EMR with hook knife was used. The other traction methods such as external grasping forceps, internal traction, double channel scope, and double scopes method are introduced in this paper. A good strategy for creating counter traction makes ESD easier.

  2. Aerogel Cherenkov Counters of the KEDR Detector

    CERN Document Server

    Ovtin, I V; Barnyakov, M Y; Bobrovnikov, V S; Buzykaev, A R; Danilyuk, A F; Katcin, A A; Kononov, S A; Kravchenko, E A; Kuyanov, I A; Onuchin, A P; Rodiakin, V A

    2017-01-01

    The particle identification system of the KEDR detector is based on aerogel threshold Cherenkov counters called ASHIPH counters. The system consists of 160 counters arranged in two layers. An event reconstruction program for the ASHIPH system was developed. The position of each counter relative to the tracking system was determined using cosmic muons and Bhabha events. The geometric efficiency of the ASHIPH system was verified with Bhabha events. The efficiency of relativistic particle detection was measured with cosmic muons. A π/K separation of 4δ in the momentum range 0.95 −1.45 GeV/c was confirmed. A simulation program for the ASHIPH counters has been developed.

  3. Counter current extraction of phosphoric acid: Food grade acid production

    International Nuclear Information System (INIS)

    Shlewit, H.; AlIbrahim, M.

    2009-01-01

    Extraction, scrubbing and stripping of phosphoric acid from the Syrian wet-phosphoric acid was carried out using Micro-pilot plant of mixer settler type of 8 l/h capacity. Tributyl phosphate (TBP)/di-isopropyl ether (DIPE) in kerosene was used as extractant. Extraction and stripping equilibrium curves were evaluated. The number of extraction and stripping stages to achieve the convenient and feasible yield was determined. Detailed flow sheet was suggested for the proposed continuous process. Data obtained include useful information for the design of phosphoric acid extraction plant. The produced phosphoric acid was characterized using different analytical techniques. (author)

  4. A COUNTER-CURRENT HEAT EXCHANGE SYSTEM IN THE TAIL ...

    African Journals Online (AJOL)

    tion of blood returning by the median system under cool conditions. .... Effect of changing ambient temperature (Ta) on core temperature (Tc). caudal .... Considering the relative thickness of the human fore-arm and vervet caudal arteries at the.

  5. Separative properties of counter-current beams type centrifuge, (2)

    International Nuclear Information System (INIS)

    Todo, Fukuzo

    1975-01-01

    One-time through scheme is studied, which would produce the highest overall centrifuge efficiency among the three different flow schemes of enriching, stripping and one-time through. If the ''optimum concentration method'' is applied to the one-time through centrifuge, the machine will be able to obtain a very high efficiency at small gas flow rates. A proposed arrangement of centrifuges for this method is shown. The efficiency of this method will be more than 15--20% higher than obtainable with enriching scheme. When the radial gas flow rate near the end caps in the rotor is increased to about 10% of the total gas feed rate, the efficiency was found to decrease by only 1%. The efficiency appears to be almost independent of small amounts of refluxing gas flow. Since a separation method having a high efficiency at small gas flow rates is required for large-scale gas centrifuge plants, the one-time through centrifuge is promising, provided the optimum concentration method is adopted. (auth.)

  6. Aerogel Cerenkov counters at DESY

    International Nuclear Information System (INIS)

    Poelz, G.

    1984-11-01

    In high energy physics it is common to identify a charged particle and its kinematical parameters by the measurement of its momentum and its velocity. Cerenkov detectors have developed into a standard tool because they operate in the γ = (1-β 2 )sup(-1/2) range from about 1 to 100 which is not easily accessible by other devices. Pions, kaons and protons in present high energy experiments reach energies of several GeV. Threshold Cerenkov detectors for these particles need indices of refraction below 1.1 which are often produced with gases under high pressure. The design for chambers operating in this region was drasticly simplified when porous materials serving as Cerenkov radiators were invented. These chambers complement the time-of-flight counters, which cover the low energy region. Aerogel of silica is up to now the only porous substance with sufficient optical transparency. Its quality has been improved substantially in recent times so that large size detectors can be constructed. (orig.)

  7. HOW THE WAR WAS ‘ONE’: COUNTERING VIOLENT EXTREMISM AND THE SOCIAL DIMENSIONS OF COUNTER-TERRORISM IN CANADA.

    Directory of Open Access Journals (Sweden)

    Tami Amanda Jacoby

    2016-03-01

    Full Text Available The current global “war on terror” highlights a fundamental quandary for all liberal democracies seeking to counter the violent extremism of their own citizens while maintaining civic rights and freedoms. This challenge accompanies a transformation in international conflict from inter-state war and superpower rivalry, to homegrown terrorism, radicalization-to-violence, Internet propaganda, and targeting and recruitment of vulnerable persons. These new threats shift the battlefield, as traditionally defined, to the home front, as extremist violence is nurtured by and perpetrated within public spaces, such as schools, places of religious worship, civil society and the home. Today, violence emanates from within liberal democratic society and its extremist motivations bypass the very institutions that would otherwise support civic rights, freedoms and multiculturalism. As such, attempts to counter extremist violence must appeal to the political, social, cultural, religious and familial aspects of human behavior alongside a parallel shift in efforts to keep citizens safe within their own social spaces. In recent years, Canada has been introduced to home grown and lone individual terrorism with the cases of attack against armed forces personnel in Saint-Jean-sur-Richelieu and Ottawa in 2014. This article identifies the social dimensions of counter-terrorism in the Canadian context, a propitious case by which to evaluate different approaches to countering violent extremism. Canadian initiatives - simultaneously proliferating and in their infancy – raise a host of questions about counter-terrorism in liberal democratic countries. For example, why do individuals radicalize-to-violence in rights-based and multicultural societies? How and when can the liberal democratic state best temper the radicalization process in ways that are effective and procedurally just? What state-society balance works best to counter radicalized viewpoints? Who are the

  8. The Validity and Reliability of the Gymaware Linear Position Transducer for Measuring Counter-Movement Jump Performance in Female Athletes

    Science.gov (United States)

    O'Donnell, Shannon; Tavares, Francisco; McMaster, Daniel; Chambers, Samuel; Driller, Matthew

    2018-01-01

    The current study aimed to assess the validity and test-retest reliability of a linear position transducer when compared to a force plate through a counter-movement jump in female participants. Twenty-seven female recreational athletes (19 ± 2 years) performed three counter-movement jumps simultaneously using the linear position transducer and…

  9. Anti-money laundering and counter-terrorist financing in the Luxembourg investment fund market

    OpenAIRE

    Dietz, Andrea

    2017-01-01

    The field of Anti-Money Laundering and Counter-Terrorist Financing in their current form have had an important impact on the financial world for almost half a century. Today, Money Laundering and Terrorist Financing pose a threat to the integrity of the financial markets and systems worldwide. The intention behind implementing a regulatory Anti-Money Laundering and Counter-Terrorist Financing framework is to cut off the financial resources of criminals and to follow back the traces that finan...

  10. On the optimum performance of forced draft counter flow cooling towers

    International Nuclear Information System (INIS)

    Soeylemez, M.S.

    2004-01-01

    A thermo-hydraulic performance optimization analysis is presented, yielding simple algebraic formula for estimating the optimum performance point of counter current mechanical draft wet cooling towers. The effectiveness-Ntu method is used in the present study, together with the derivation of psychometric properties of moist air based on a numerical approximation method, for thermal performance analysis of wet cooling towers of the counter flow type

  11. Counter-diabatic driving for Dirac dynamics

    Science.gov (United States)

    Fan, Qi-Zhen; Cheng, Xiao-Hang; Chen, Xi

    2018-03-01

    In this paper, we investigate the fast quantum control of Dirac equation dynamics by counter-diabatic driving, sharing the concept of shortcut to adiabaticity. We systematically calculate the counter-diabatic terms in different Dirac systems, like graphene and trapped ions. Specially, the fast and robust population inversion processes are achieved in Dirac system, taking into account the quantum simulation with trapped ions. In addition, the population transfer between two bands can be suppressed by counter-diabatic driving in graphene system, which might have potential applications in opt-electric devices.

  12. 21 CFR 866.2170 - Automated colony counter.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2170 Automated colony counter. (a) Identification. An automated colony counter is a mechanical device intended for medical...

  13. Financial Worldwide Crisis: The Anti-Counter Cycle of Australia

    Directory of Open Access Journals (Sweden)

    Joao NEGREIROS

    2013-12-01

    Full Text Available If Australia has been subject to major influences by the United States and European countries, why is its economy healthier than their counter partners? What are the economic foundations that underline this anti-counter cycle of financial worldwide crisis from Australia? What are some of the lessons that countries from Europe that have not fared during the current financial worldwide crisis should learn from Australia? The purpose of this paper is to review the present Australian management system. Four changes are identified including embracement of corporate governance, a shift to adopt more R&D activities, a shift to adopt environmental sustainability practices and emerging corporate social responsibility. On the conclusions settings, a recap and recommendation on how Portugal, a member of the PIGS (Portugal, Italy, Greece and Spain Southern European Countries club forgot to embrace directives that have been applied in Australia, to avoid the actual financial and identity crisis.

  14. The counter ion: expanding excipient functionality

    Directory of Open Access Journals (Sweden)

    Shireesh Apte

    2011-06-01

    Full Text Available Excipients have increasingly become 'enablers' of drug delivery and efficacy rather than passive bystanders. Advances in pharmaceutical technology have enabled the ability to deliver specific counter ions (in the form of the counter ion containing excipient and the API simultaneously to preselected targets in the body. This, coupled with a near universal mechanism of columbic interactions that determine the [API- counter ion] efficacy, can be harnessed to exploit this hitherto unavailable or unrecognized enabling mechanism. New excipients may be assembled by a near inexhaustible supply of different permutations of counter ions and their judicious use in specific situations could potentially drive a renaissance in excipient innovation (and drug delivery and efficacy despite regulatory stagnation.

  15. Geometric covers, graph orientations, counter games

    DEFF Research Database (Denmark)

    Berglin, Edvin

    -directed graph is dynamic (can be altered by some outside actor), some orientations may need to be reversed in order to maintain the low out-degree. We present a new algorithm that is simpler than earlier work, yet matches or outperforms the efficiency of these results with very few exceptions. Counter games...... example is Line Cover, also known as Point-Line Cover, where a set of points in a geometric space are to be covered by placing a restricted number of lines. We present new FPT algorithms for the sub-family Curve Cover (which includes Line Cover), as well as for Hyperplane Cover restricted to R 3 (i...... are a type of abstract game played over a set of counters holding values, and these values may be moved between counters according to some set of rules. Typically they are played between two players: the adversary who tries to concentrate the greatest value possible in a single counter, and the benevolent...

  16. Count rate effect in proportional counters

    International Nuclear Information System (INIS)

    Bednarek, B.

    1980-01-01

    A critical evaluaton is presented of the actual state of investigations and explanations of the resolution and pulse height changes resulted in proportional counters from radiation intensity variations. (author)

  17. Counter-Leadership Targeting and Conflict Termination

    National Research Council Canada - National Science Library

    Taylor, Bradly

    1999-01-01

    .... Can the leader be found? And, is it legal and ethical to attack the leader? Analysis rarely has been conducted to determine whether the targeted organization is vulnerable to Counter Leadership Targeting (CLT...

  18. Countering North Korean Special Purpose Forces

    National Research Council Canada - National Science Library

    Krause, Troy

    1999-01-01

    As United States and Republic of Korea forces stand to defend against a DPRK attack, one of the most formidable tasks is how to counter a second front in the Joint Rear Security Area of the Republic of Korea...

  19. Tests of BF3 counters with getter

    International Nuclear Information System (INIS)

    Comte, R.; Dauphin, G.

    1968-01-01

    BF 3 counters with addition of a getter have been developed to improve operation characteristics of these detectors in presence of strong gamma flows. The getter is made of an active coal deposit on the cathode. As noticed by other studies, the degradation of these counters is related to the exposure to strong neutron flows and to gamma radiations. The authors report tests performed on these counters with a brief presentation of the counters, and a presentation of the test installation. A threshold curve and an amplitude spectrum are obtained, and counting is performed for a fixed threshold before and after the exposure of detectors to variable doses of γ radiation. The results after a first 2 hour long irradiation, a 230 hour long second irradiation, and a third irradiation under high voltage (2100 V) are discussed. Thermal tests are then performed and commented

  20. Real-time {sup 90}Sr Counter

    Energy Technology Data Exchange (ETDEWEB)

    Kaneko, Naomi; Kawai, Hideyuki; Kodama, Satoshi; Kobayashi, Atsushi; Tabata, Makoto; Ito, Hiroshi [Graduate School of Science, Chiba University, Chiba, (Japan); Han, Soorim [Graduate School of Science, Chiba University, Chiba, (Japan); National Institute of Radiological Science, Chiba, (Japan)

    2015-07-01

    Radioisotopes have been emitted around Japan due to a nuclear accident at the Fukushima Daiichi nuclear power station in March 2011. A problem is the contaminated water including the atomic nucleus which relatively has a long half- life time and soluble such as {sup 90}Sr, {sup 137}Cs. Internal exposures by {sup 90}Sr are more dangerous than {sup 137}Cs's because Sr has effective half-life time of 18 years and property of accumulation in a born. We have developed real-time {sup 90}Sr counter which is sensitive beta-ray of maximum kinematic energy of 2.28 MeV from {sup 90}Sr and insensitive of beta-ray of maximum kinematic energy of 1.17 MeV and gamma-ray from {sup 90}Sr by Cherenkov detection. This counter composes of Cerenkov counter, trigger scintillation counter and veto counter. Silica aerogel for Cherenkov counter can obtain refractive index between 1.017 and 1.049 easily. And wavelength shifting fiber (WLSF) is used as a light guide for extending effective area and producing lower cost. A mechanism of the identification of {sup 90}Sr is explained in following. In case of {sup 90}Sr, when the trigger counter reacts on the beta-ray from {sup 90}Sr, aerogel emits the Cherenkov light and WLSF reacts and read the Cherenkov light. On the other hand, in case of {sup 137}Cs, the trigger counter reacts on the beta-ray, aerogel stops the beta- ray and Cherenkov light is not emitted. Therefore, aerogel has a function as a radiator and shielding material. the gamma-ray is not reacted on the lower density detector. Cosmic rays would be also reacted by the veto counter. A prototype counter whose the effective area is 30 cm x 10 cm was obtained (2.0±1.2){sup 3} of mis-identification as {sup 137}Cs/{sup 90}Sr. Detection limit in the surface contamination inspection depends on measurement time and effective area mainly. The sensitivity of wide range, 10{sup -2} - 10{sup 4} Bq/cm{sup 2}, is obtained by adjustment of detection level in circuit of this counter. A lower

  1. Counter - Drug: Mandate for the Army.

    Science.gov (United States)

    1991-03-01

    this comprehensive review will provide a basis for responding to new missions assigned...observations for determining the short-, mid-, and long-term direction of Army support to the national counter-drug effort. Also, this comprehensive review will provide...and long-term direction of Army support to the national counter-drug effort. Also, this comprehensive review will provide a basis for responding

  2. Lifetime characteristics of Gaiger-Muller counters

    Directory of Open Access Journals (Sweden)

    Kartalović Nenad M.

    2016-01-01

    Full Text Available This paper discusses the process of functional aging of Geiger-Muller counters. Two types of Geiger-Muller counter chambers were characterized in an experiment using a combined constant voltage. Chamber A had a coaxial geometry and chamber B had a plan-parallel geometry. The experimental results indicate that the aging process was faster in the case of chambers with a coaxial geometry. The results are explained based on the process of electrical discharges in gasses.

  3. Quality control and the multicrystal counter

    International Nuclear Information System (INIS)

    Hart, G.C.; Davis, K.M.

    1983-01-01

    The reliability of multicrystal counters for use in counting large numbers of radioimmunoassay samples is studied. In particular, the dependencies of the outputs from the array of detectors, and hence their degree of matching, on the count rate and volume of the samples being counted are investigated. Quality control procedures are described to assist in the assurance of consistent performance of the counter in the clinical situation. (U.K.)

  4. Pulse formation of gas-filled counter

    International Nuclear Information System (INIS)

    Iwatani, Kazuo; Teshima, Kazunori; Shizuma, Kiyoshi; Hasai, Hiromi

    1991-01-01

    The pulse formation of gas-filled counter has been calculated by simple models for the proportional and self-quenching streamer (SQS) modes. Calculated pulse shapes of counter output have accurately reproduced the observed ones for both modes. As a result, it is shown that the special density distribution of ion pairs in a streamer can be estimated with the rising part of observed pulse shape, using the model. (author)

  5. Development of a Mobile Ice Nucleus Counter

    Energy Technology Data Exchange (ETDEWEB)

    Kok, Gregory [Droplet Measurement Technologies, Boulder, CO (United States); Kulkarni, Gourihar [Droplet Measurement Technologies, Boulder, CO (United States)

    2014-07-10

    An ice nucleus counter has been constructed. The instrument uses built-in refrigeration systems for wall cooling. A cascade refrigeration system will allow the cold wall to operate as low as -70°C, and a single stage system can operate the warm wall at -45C. A unique optical particle counter has been constructed using polarization detection of the scattered light. This allows differentiation of the particles exiting the chamber to determine if they are ice or liquid.

  6. Calibration methodology for proportional counters applied to yield measurements of a neutron burst

    Energy Technology Data Exchange (ETDEWEB)

    Tarifeño-Saldivia, Ariel, E-mail: atarifeno@cchen.cl, E-mail: atarisal@gmail.com; Pavez, Cristian; Soto, Leopoldo [Comisión Chilena de Energía Nuclear, Casilla 188-D, Santiago (Chile); Center for Research and Applications in Plasma Physics and Pulsed Power, P4, Santiago (Chile); Departamento de Ciencias Fisicas, Facultad de Ciencias Exactas, Universidad Andres Bello, Republica 220, Santiago (Chile); Mayer, Roberto E. [Instituto Balseiro and Centro Atómico Bariloche, Comisión Nacional de Energía Atómica and Universidad Nacional de Cuyo, San Carlos de Bariloche R8402AGP (Argentina)

    2014-01-15

    This paper introduces a methodology for the yield measurement of a neutron burst using neutron proportional counters. This methodology is to be applied when single neutron events cannot be resolved in time by nuclear standard electronics, or when a continuous current cannot be measured at the output of the counter. The methodology is based on the calibration of the counter in pulse mode, and the use of a statistical model to estimate the number of detected events from the accumulated charge resulting from the detection of the burst of neutrons. The model is developed and presented in full detail. For the measurement of fast neutron yields generated from plasma focus experiments using a moderated proportional counter, the implementation of the methodology is herein discussed. An experimental verification of the accuracy of the methodology is presented. An improvement of more than one order of magnitude in the accuracy of the detection system is obtained by using this methodology with respect to previous calibration methods.

  7. Calibration methodology for proportional counters applied to yield measurements of a neutron burst

    International Nuclear Information System (INIS)

    Tarifeño-Saldivia, Ariel; Pavez, Cristian; Soto, Leopoldo; Mayer, Roberto E.

    2014-01-01

    This paper introduces a methodology for the yield measurement of a neutron burst using neutron proportional counters. This methodology is to be applied when single neutron events cannot be resolved in time by nuclear standard electronics, or when a continuous current cannot be measured at the output of the counter. The methodology is based on the calibration of the counter in pulse mode, and the use of a statistical model to estimate the number of detected events from the accumulated charge resulting from the detection of the burst of neutrons. The model is developed and presented in full detail. For the measurement of fast neutron yields generated from plasma focus experiments using a moderated proportional counter, the implementation of the methodology is herein discussed. An experimental verification of the accuracy of the methodology is presented. An improvement of more than one order of magnitude in the accuracy of the detection system is obtained by using this methodology with respect to previous calibration methods

  8. The Banking Counter-Guarantee. Juridical Regime

    Directory of Open Access Journals (Sweden)

    Postolache Rada

    2009-06-01

    Full Text Available Not so much studied by the specialised literature, the banking counter-guarantee may beconfounded with the other types of guarantee which frequently go with the guaranteed obligation –simple guarantee, collateral guarantee, the confirmation of the guarantee. The counter-guarantee may bean independent or accessory obligation, as the case may be, exclusively governed by its text, accordingto the parties’ will. At the same time, it is a complex juridical act, a contract whose contents cannot beset apart from the contracts connected form an “economic” point of view. The counter-guarantee is theresult of the banking practice and is generated by the need to make amends for the flaws generated bythe direct guarantee. The present research is focused on the analysis of the banking practice, normativeacts, jurisprudence and banking juridical literature.

  9. CORNELL: CLEO's counters

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Particle identification by measuring ionization is complicated by the fact that the energy lost to ionization in passing through matter has large fluctuations, first calculated by Landau. These large fluctuations imply that many measurements must be made in order to determine the most probable ionization value that is characteristic of the particle type. The JADE chamber at PETRA and the TPC chamber at PEP measure both the ionization and the momenta of tracks in the same device. In the CLEO experiment at Cornell's CESR ring, ionization is measured in dedicated energy loss counters contained in each of the eight octants surrounding the drift chamber and superconducting coil. The last of these were installed in the summer of 1981, replacing Cherenkov counters that were used while the energy loss counters were being developed and built

  10. An extended range neutron rem counter

    International Nuclear Information System (INIS)

    Birattari, C.; Nuccetelli, C.; Pelliccioni, M.; Silari, M.

    1990-01-01

    Extensive Monte Carlo calculations have been carried out to assess the possibility of extending the sensitivity of a neutron rem counter of the Andersson-Braun type up to several hundred MeV. The validity of the model adopted has first been checked by comparing with experimental data the calculated response curve and the angular dependence of the sensitivity for a well known commercial rem counter. Next, a number of modifications to the configuration of the moderator-attenuator have been investigated. The response functions and angular distributions produced by two simple solutions yielding an instrument with a sensitivity extended up to 400 MeV are presented. The response of the original rem counter and of its two modified versions to nine test spectra has also been calculated. The resulting instrument is transportable rather than portable, but the availability of an extended range neutron survey meter would be of great advantage at medium and high energy particle accelerator facilities. (orig.)

  11. Sculptured platinum nanowire counter electrodes for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeonseok [Department of Electrical Engineering, Pennsylvania State University, University Park 16802 (United States); Horn, Mark W., E-mail: MHorn@engr.psu.edu [Department of Engineering Science and Mechanics, Pennsylvania State University, University Park 16802-6812 (United States)

    2013-07-01

    Sculptured platinum nanowire thin films were formed by oblique angle electron beam evaporation with a 5° vapor incidence angle and incorporated as counter electrodes for dye-sensitized solar cells (DSSCs). For the comparison of the performance, bare fluorine doped tin oxide, planar Pt electrodes and counter electrodes treated with chloroplatinic acid were prepared. The sculptured Pt nanowire electrodes showed five times lower charge transfer resistance (0.121 [Ω∗cm{sup 2}]) than that of Pt planar electrode (0.578 [Ω∗cm{sup 2}]) and when the Pt nanowire electrodes are treated with an H{sub 2}PtCl{sub 6} solution have more than ten times lower charge transfer resistance (0.04025 [Ω∗cm{sup 2}]). Moreover, Pt nanowire films used as a counter electrode lead to enhancement in current density and efficiency in comparison with Pt planar counter electrodes. The conversion efficiency with planar electrodes was 5.1 [%] while the efficiency of DSSC with platinum nanowire counter electrodes reached to 5.63 [%] under AM 1.5 illumination. - Highlights: • Pt sculptured thin films (STFs) fabricated by electron beam evaporator. • The STFs featured higher roughness and lower charge transfer resistance. • Improved performance of dye-sensitized solar cells by Pt STFs counter electrodes.

  12. Countering Islamic Radicalization Indonesian Experiences

    Science.gov (United States)

    2016-02-16

    promote values and beliefs that create the impression that controlling and maintaining current global structure benefits all, when in fact it works...success in a globalized and digital world. Most of the Islamic school students also got outdoor activities such as sports, farming, hiking , marching... benefiting from a bigger audience, and spreads the terror almost instantaneously, because the main victims of the attacks are the people who watch the

  13. Calibration of nuclear medicine gamma counters

    International Nuclear Information System (INIS)

    Orlic, M.; Spasic-Jokic, V.; Jovanovic, M.; Vranjes, S. . E-mail address of corresponding author: morlic@vin.bg.ac.yu; Orlic, M.)

    2005-01-01

    In this paper the practical problem of nuclear medicine gamma counters calibration has been solved by using dose calibrators CRC-15R with standard error ±5%. The samples from technetium generators have been measured both by dose calibrators CRC-15R and gamma counter ICN Gamma 3.33 taking into account decay correction. Only the linear part of the curve has practical meaning. The advantage of this procedure satisfies the requirements from international standards: the calibration of sources used for medical exposure be traceable to a standard dosimetry laboratory and radiopharmaceuticals for nuclear medicine procedures be calibrated in terms of activity of the radiopharmaceutical to be administered. (author)

  14. Analysis of counter-rotating wind turbines

    DEFF Research Database (Denmark)

    Shen, Wen Zhong; Zakkam, Vinod Arun Kumar; Sørensen, Jens Nørkær

    2007-01-01

    This paper presents a study on the performance of a wind turbine with two counter-rotating (CRWT) rotors. The characteristics of the two counter-rotating rotors are on a 3-bladed Nordtank 500 kW rotor. The analysis has been carried out by using an Actuator Line technique implemented in the Navier......-Stokes code EllipSys3D. The analysis shows that the Annual Energy Production can be increased to about 43.5 %, as compared to a wind turbine with a single rotor. In order to determine the optimal settings of the CRWT turbine, parameters such as distance between two rotors and rotational speed have been...

  15. Development of DUPIC safeguards neutron counter

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Gil; Cha, Hong Ryul; Kim, Ho Dong; Hong, Jong Sook; Kang, Hee Young

    1999-08-01

    KAERI, in cooperation with LANL, developed DSNC (DUPIC Safeguards Neutron Counter) for safeguards implementing on DUPIC process which is under development by KAERI for direct use of spent PWR fuel in CANDU reactors. DSNC is a well-type neutron coincidence counter with substantial shielding to protect system from high gamma radiation of spent fuel. General development procedures in terms of design, manufacturing, fabrication, cold and hot test, performance test for DSNC authentication by KAERI-IAEA-LANL are described in this report. It is expected that the techniques related DSNC development and associated neutron detection and evaluation method could be applied for safeguards improvement. (Author). 20 refs., 16 tabs. 98 figs.

  16. Counter of radiation in body parts

    International Nuclear Information System (INIS)

    Pollard, D.E.

    1983-01-01

    A new radiation counter for the determination of radiocontaminated body parts has been designed. Composed of several movable detectors, shielded from background radiation and focused on different parts of the human body by narrow apertures in the lead enclosure, the invention provides a quick tool for quantitative and qualitative part-by-part analysis of the body with respect to radiocontamination. The counter can be handled easily by the tested person himself and consequently, it is suitable for mass controls etc. (G.J.P.)

  17. Whole body counters: types, performance and uses

    International Nuclear Information System (INIS)

    Jales, R.L.C.

    1983-01-01

    The present monograph deals with Whole Counters, since its definition, evolution, performance, clinical indications and results. Scintillation crystals detection systems were described as well as scintillant solutions, plastic scintillations, and gaseous detectors, including its interplay forms and basal characteristics. Geometric arrangements of standard chair, arc and hammock, arrangements with scintillant solutions and plastic scintillations, as well as special geometric arrangements were equally commented. Clinic and experimental studies were also dealt with Whole Body Counters, giving examples with potassium, iron vitamin B 12 and albumin. (author)

  18. Intercalibration of CDTN and IRD whole body counters

    International Nuclear Information System (INIS)

    Dantas, B.M.; Dantas, A.L.A.; Alonso, T.C.

    2008-01-01

    Full text: Intercalibration exercises are designed to harmonize analytical techniques and ensure reliability of measurement results performed in a laboratory network. Such strategy helps to improve laboratory performance among participants in future intercomparison exercises, when it is verified the metrological capacity, by determining accuracy, precision and reproducibility of data produced by each laboratory. In Brazil, there are currently four in vivo monitoring systems, located in IRD, in Rio de Janeiro, CDTN, in Belo Horizonte, IPEN, in Sao Paulo and CNAAA, in Angra dos Reis. Such systems, generically referred as whole body counters, aim to detect and quantify radionuclides in organs and tissues for radiological protection purposes and to provide useful information for studies on biokinetic behavior of radionuclides in humans and animals. The objective of this work is to establish a methodology to be applied for intercalibration of whole body counters. The IRD whole body counter is installed in a 15 cm steel shielded room where two NaI(Tl) and four HPGe detectors are calibrated for the determination of radionuclides in the energy range from 10 to 3000 keV. The CDTN whole body counter has one NaI detector set up in a shadow shield configuration, and is able to determine radionuclides emitting photons from 100 to 2000 keV. The intercalibration exercise described in this work was planed for whole body geometry using the scintillation detectors available in both laboratories. It was used a thin glass vial containing 2,6615 g of a solution of four gamma emitters ( 57 Co, 137 Cs, 54 Mn, 65 Zn), supplied by the National Laboratory for Metrology of Ionizing Radiation (LNMRI-IRD). The glass vial was measured in the same geometry in both IRD and CDTN whole body counters, being positioned at 31,5 cm distance from the NaI(Tl) detector of each laboratory. The calibration curves (photo peak channel and Efficiency vs Energy) of each detection system were compared. The

  19. 'Miniskirt' counter array at CDF II

    International Nuclear Information System (INIS)

    Artikov, A.; Artikov, A.

    2006-01-01

    Full text: Muon detection is fundamental for the most of the interesting analyses at CDF. At the course of Run II, the collaboration expects to collect hundreds of t t-bar decays yielding a muon as well as several million B-hadron events involving J/ψ → μ + μ - decays. Muon detection is also of fundamental importance in the study of W-boson properties and in the search for Higgs production associated with W or Z bosons. Considerable effort therefore went into extending the muon detector coverage for Run II, which started in March 2001. The CDF II muon detector system consists of multiple layers of drift chambers and scintillation counters, which span the pseudorapidity (|η|) range between 0 and 1.5. Detectors spanning different ranges have different geometries, and the muon scintillation counter system includes subsystems in the regions that have come to be known as the 'central' (0 pe for WLS fiber readout is smaller than for conventional readout, we can also expect an increase in the statistical contribution to the overall uncertainty. Our first concern, before adopting this solution, was therefore to ascertain that the mean timing resolution obtained under these conditions was adequate. The modifications, testing and installation of these counters within the CDF Upgrade Project are described in detail. The timing characteristics of MSX' counters are also investigated using cosmic muons. The measurements show that the time resolution does not exceed 2.2 ns. (author)

  20. Cerenkov counters at the Omega Facility

    CERN Multimedia

    1975-01-01

    P. Petroff on the left. Here one sees both the gas Cerenkov counters sitting in front of the magnet to select forward emitted particles. The smaller one, working at high pressure, sits nearest to the Omega magnet (see photo 7505073X), the other (see photo 7505071X) works at atmospheric pressure.

  1. A gridded air counter for measuring exoelectrons

    International Nuclear Information System (INIS)

    Nagase, Makoto; Chiba, Yoshiya; Kirihata, Humiaki.

    1980-01-01

    A gridded air counter with a quenching circuit is described, which serves to detect low-energy electrons such as thermionic electrons, photoelectrons and exoelectrons emitted into the atmospheric air. The air counter consists of a loop-shaped anode and two grids provided for quenching the gas discharge and for protecting the electron emitter from the positive ion bombardment. The quenching circuit with a high input sensitivity of 5 mV detects the initiation gas discharge caused by an incident electron and immediately supplies a rectangular wave pulse of 300 V in amplitude and of more than 3 msec in width to the quenching grid near the anode. Simultaneously, the voltage of the suppressor grid is brought down and kept at -30 V against the earthed sample for the same period of time. Performance of the gridded air counter was examined by use of photoelectrons emitted from an abraded aluminum plate. The quenching action was successfully accomplished in the anode voltage range from 3.65 to 3.95 kV. The photoelectrons emitted into the atmosphere could be counted stably by use of this counter. (author)

  2. Platelet counting using the Coulter electronic counter.

    Science.gov (United States)

    Eggleton, M J; Sharp, A A

    1963-03-01

    A method for counting platelets in dilutions of platelet-rich plasm using the Coulter electronic counter is described.(1) The results obtained show that such platelet counts are at least as accurate as the best methods of visual counting. The various technical difficulties encountered are discussed.

  3. Counter Trafficking System Development "Analysis Training Program"

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Dennis C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-12-01

    This document will detail the training curriculum for the Counter-Trafficking System Development (CTSD) Analysis Modules and Lesson Plans are derived from the United States Military, Department of Energy doctrine and Lawrence Livermore National Laboratory (LLNL), Global Security (GS) S Program.

  4. Sealed drift tube cosmic ray veto counters

    International Nuclear Information System (INIS)

    Rios, R.; Tatar, E.; Bacon, J.D.; Bowles, T.J.; Hill, R.; Green, J.A.; Hogan, G.E.; Ito, T.M.; Makela, M.; Morris, C.L.; Mortenson, R.; Pasukanics, F.E.; Ramsey, J.; Saunders, A.; Seestrom, S.J.; Sondheim, W.E.; Teasdale, W.; Saltus, M.; Back, H.O.; Cottrell, C.R.

    2011-01-01

    We describe a simple drift tube counter that has been used as a cosmic ray veto for the UCNA experiment, a first-ever measurement of the neutron beta-asymmetry using ultra-cold neutrons. These detectors provide an inexpensive alternative to more conventional scintillation detectors for large area cosmic ray anticoincidence detectors.

  5. COUNTER-ROTATION IN RELATIVISTIC MAGNETOHYDRODYNAMIC JETS

    Energy Technology Data Exchange (ETDEWEB)

    Cayatte, V.; Sauty, C. [Laboratoire Univers et Théories, Observatoire de Paris, UMR 8102 du CNRS, Université Paris Diderot, F-92190 Meudon (France); Vlahakis, N.; Tsinganos, K. [Department of Astrophysics, Astronomy and Mechanics, Faculty of Physics, University of Athens, 15784 Zografos, Athens (Greece); Matsakos, T. [Department of Astronomy and Astrophysics, The University of Chicago, Chicago, IL 60637 (United States); Lima, J. J. G., E-mail: veronique.cayatte@obspm.fr [Centro de Astrofísica, Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal)

    2014-06-10

    Young stellar object observations suggest that some jets rotate in the opposite direction with respect to their disk. In a recent study, Sauty et al. showed that this does not contradict the magnetocentrifugal mechanism that is believed to launch such outflows. Motion signatures that are transverse to the jet axis, in two opposite directions, have recently been measured in M87. One possible interpretation of this motion is that of counter-rotating knots. Here, we extend our previous analytical derivation of counter-rotation to relativistic jets, demonstrating that counter-rotation can indeed take place under rather general conditions. We show that both the magnetic field and a non-negligible enthalpy are necessary at the origin of counter-rotating outflows, and that the effect is associated with a transfer of energy flux from the matter to the electromagnetic field. This can be realized in three cases: if a decreasing enthalpy causes an increase of the Poynting flux, if the flow decelerates, or if strong gradients of the magnetic field are present. An illustration of the involved mechanism is given by an example of a relativistic magnetohydrodynamic jet simulation.

  6. Townsend coefficients of gases in avalanche counters

    International Nuclear Information System (INIS)

    Brunner, G.

    1978-01-01

    Though much work has been done by many authors in the last few years in the development and application of avalanche counters for ion radiation, it is based upon values of the Townsend coefficients as the essential gas parameter, which were determined many years ago for much lower reduced field strengths F/p than prevail in such counters. Therefore absolute determinations of α in vapours of methyl alcohol, cyclohexane, acetone, and n-heptene were performed under original conditions of avalanche counters. The values obtained do not differ by more than 30%-50% from the former values indeed, extrapolated over F/p for the first three mentioned substances, but the amounts of A and B in the usual representation α/p=A exp(-B(F/p)) are much greater for the stronger reduced fields. This is of importance for such counter properties as the dependence of pulse heights on pressure, voltage, electrode distance etc., which are governed by other combinations of A and B than α/p itself. A comparison of results for different ionic radiations shows a marked influence of the primary ionization density along the particle tracks which is hard to explain. (Auth.)

  7. Can counter-stereotypes boost flexible thinking?

    NARCIS (Netherlands)

    Goclowska, M.A.; Crisp, R.J.; Labuschagne, K.

    2013-01-01

    To reduce prejudice psychologists design interventions requiring people to think of counter-stereotypes (i.e., people who defy stereotypic expectations—a strong woman, a Black President). Grounded in the idea that stereotypes constrain the ability to think flexibly, we propose that thinking of

  8. Calibration of proportional counters in microdosimetry

    International Nuclear Information System (INIS)

    Varma, M.N.

    1982-01-01

    Many microdosimetric spectra for low LET as well as high LET radiations are measured using commercially available (similar to EG and G) Rossi proportional counters. This paper discusses the corrections to be applied to data when calibration of the counter is made using one type of radiation, and then the counter is used in a different radiation field. The principal correction factor is due to differences in W-value of the radiation used for calibration and the radiation for which microdosimetric measurements are made. Both propane and methane base tissue-equivalent (TE) gases are used in these counters. When calibrating the detectors, it is important to use the correct stopping power value for that gas. Deviations in y-bar/sub F/ and y-bar/sub D/ are calculated for 60 Co using different extrapolation procedures from 0.15 keV/μm to zero event size. These deviations can be as large as 30%. Advantages of reporting microdosimetric parameters such as y-bar/sub F/ and y-bar/sub D/ above a certain minimum cut-off are discussed

  9. E143 experiment. Shower counter calibration

    International Nuclear Information System (INIS)

    Fonvieille, H.; Grenier, P.

    1994-01-01

    The calibration procedure for the shower counters used in the E143 experiment is described. It has been developed during january 1994 in view of being used for the quick analysis. The method is explained and the results obtained on a given run are presented. (author)

  10. Geiger-Muller (GM) counters. Associated circuits and counting techniques; Les compteurs de Geiger-Muller (GM). Les circuits associes et techniques de comptage

    Energy Technology Data Exchange (ETDEWEB)

    Benoit, A.; Picard, E. [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay (France)

    1954-07-01

    This article presents the Geiger-Muller counters which present the great benefit of being simple and steady in comparison with other known sensors. The authors propose an overview of problems related to the use of Geiger-Muller counters (GM counters). They first describe their operation (discharge initiation, discharge propagation, collection of positive ions and current in the counter). They discuss their limitations which are related to the migration delay of primary electrons and positive ions. They describe the operation circuit for counters with organic vapour, and for counters associated with counters using halogens. They address the main properties of GM counters, and the different factors to be taken into account when using them to count radioactive sources. The main types of GM counters are then described (they are used to measure different types of radiation). Measurement techniques are discussed for beta radiation (relationship between the number of disintegrations and the noticed counting rate, case of backscattering, absorption and diffusion in the counter window and in the air, influence of absorption and backscattering in the source), for alpha radiation, and for gamma radiation.

  11. Electrochemically Deposited Polypyrrole for Dye-Sensitized Solar Cell Counter Electrodes

    Directory of Open Access Journals (Sweden)

    Khamsone Keothongkham

    2012-01-01

    Full Text Available Polypyrrole films were coated on conductive glass by electrochemical deposition (alternative current or direct current process. They were then used as the dye-sensitized solar cell counter electrodes. Scanning electron microscopy revealed that polypyrrole forms a nanoparticle-like structure on the conductive glass. The amount of deposited polypyrrole (or film thickness increased with the deposition duration, and the performance of polypyrrole based-dye-sensitized solar cells is dependant upon polymer thickness. The highest efficiency of alternative current and direct current polypyrrole based-dye-sensitized solar cells (DSSCs is 4.72% and 4.02%, respectively. Electrochemical impedance spectroscopy suggests that the superior performance of alternative current polypyrrole solar cells is due to their lower charge-transfer resistance between counter electrode and electrolyte. The large charge-transfer resistance of direct current solar cells is attributed to the formation of unbounded polypyrrole chains minimizing the I3 − reduction rate.

  12. Israel's Counter-Terrorism Strategy and its Effectiveness

    National Research Council Canada - National Science Library

    Smith, Jerry D

    2005-01-01

    This thesis analyzes Israeli counter-terrorism strategy and its effectiveness. Because of ongoing suicide attacks from Palestinian and other terrorist organizations, Israel will continue to have an aggressive counter-terrorism strategy...

  13. 21 CFR 866.2180 - Manual colony counter.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2180 Manual colony counter. (a) Identification. A manual colony counter is a device intended for medical purposes that consists...

  14. Rules for congestion management. Evaluation of available of capacity and possibilities for increased counter trade

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-08-01

    In the Nordic electricity market, congestion is currently managed using two methods: a combination of price areas (market splitting) and counter-trade. In the planning phase (one day ahead) the main method employed is market splitting, although moving internal bottlenecks to the country border and domestic counter-trade are also used to some degree. Congestion is solved through counter- trade in the operating phase (during the day). In spring 2002, Nordel published a report with proposals for possible changes in Nordic congestion management. The main proposal was to introduce new price areas in the spot market and let the borders of price areas coincide with the physical borders of congestion in the transmission network to a greater degree. It was also proposed to increase the use of counter-trade. Based on feedback from Nordic market players, Nordel decided to carry on the work with congestion management in a new ad hoc group. The group's mandate was a Nordic harmonization of rules and practices for congestion management and a socio-economically efficient utilisation of the transmission grid capacity. Furthermore, the group was asked to investigate how to ensure optimal availability of capacity and to look into the possibilities of increasing usage of counter-trade. The ad hoc working group results are presented in this report. Among the conclusions drawn from the investigations are: 1) A limited increase of counter-trade in the planning phase is feasible for temporary congestion in order to reduce the area price risks for the market players, 2) Market participants should be consulted to get their views on whether and to what extent counter-trade should be increased taking benefits and costs into account. The extent of counter-trade could e.g. be decided as a percentage of NCT with intact grid, 3) Nordel should consider a practice where counter-trading is used to prevent reductions in cross-border capacity due to maintenance, 4) The use of counter-trade in

  15. Rules for congestion management. Evaluation of availability of capacity and possibilities for increased counter trade

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-08-01

    In the Nordic electricity market, congestion is currently managed using two methods: a combination of price areas (market splitting) and counter-trade. In the planning phase (one day ahead) the main method employed is market splitting, although moving internal bottlenecks to the country border and domestic counter-trade are also used to some degree. Congestion is solved through counter- trade in the operating phase (during the day). In spring 2002, Nordel published a report with proposals for possible changes in Nordic congestion management. The main proposal was to introduce new price areas in the spot market and let the borders of price areas coincide with the physical borders of congestion in the transmission network to a greater degree. It was also proposed to increase the use of counter-trade. Based on feedback from Nordic market players, Nordel decided to carry on the work with congestion management in a new ad hoc group. The group's mandate was a Nordic harmonization of rules and practices for congestion management and a socio-economically efficient utilisation of the transmission grid capacity. Furthermore, the group was asked to investigate how to ensure optimal availability of capacity and to look into the possibilities of increasing usage of counter-trade. The ad hoc working group results are presented in this report. Among the conclusions drawn from the investigations are: 1) A limited increase of counter-trade in the planning phase is feasible for temporary congestion in order to reduce the area price risks for the market players, 2) Market participants should be consulted to get their views on whether and to what extent counter-trade should be increased taking benefits and costs into account. The extent of counter-trade could e.g. be decided as a percentage of NCT with intact grid, 3) Nordel should consider a practice where counter-trading is used to prevent reductions in cross-border capacity due to maintenance, 4) The use of counter-trade in

  16. Rules for congestion management. Evaluation of availability of capacity and possibilities for increased counter trade

    International Nuclear Information System (INIS)

    2004-08-01

    In the Nordic electricity market, congestion is currently managed using two methods: a combination of price areas (market splitting) and counter-trade. In the planning phase (one day ahead) the main method employed is market splitting, although moving internal bottlenecks to the country border and domestic counter-trade are also used to some degree. Congestion is solved through counter- trade in the operating phase (during the day). In spring 2002, Nordel published a report with proposals for possible changes in Nordic congestion management. The main proposal was to introduce new price areas in the spot market and let the borders of price areas coincide with the physical borders of congestion in the transmission network to a greater degree. It was also proposed to increase the use of counter-trade. Based on feedback from Nordic market players, Nordel decided to carry on the work with congestion management in a new ad hoc group. The group's mandate was a Nordic harmonization of rules and practices for congestion management and a socio-economically efficient utilisation of the transmission grid capacity. Furthermore, the group was asked to investigate how to ensure optimal availability of capacity and to look into the possibilities of increasing usage of counter-trade. The ad hoc working group results are presented in this report. Among the conclusions drawn from the investigations are: 1) A limited increase of counter-trade in the planning phase is feasible for temporary congestion in order to reduce the area price risks for the market players, 2) Market participants should be consulted to get their views on whether and to what extent counter-trade should be increased taking benefits and costs into account. The extent of counter-trade could e.g. be decided as a percentage of NCT with intact grid, 3) Nordel should consider a practice where counter-trading is used to prevent reductions in cross-border capacity due to maintenance, 4) The use of counter-trade in the

  17. A fast photo-counter with multi-level buffers

    International Nuclear Information System (INIS)

    Peng Hu; Zhou Peiling; Yao Kun; Guo Guangcan

    1992-01-01

    Digital Photon Correlator (DPC) is composed of a Photo-counter and a data processing unit. The performance of Photo-counter in data acquisition system has a direct influence on data processing. The Photo-counter with fast carry designed here has multi-level buffers. Photon pulses can be correctly and dynamically recorded by the Photo-counter and processed by a single chip computer

  18. Efficiency calibration of solid track spark auto counter

    International Nuclear Information System (INIS)

    Wang Mei; Wen Zhongwei; Lin Jufang; Liu Rong; Jiang Li; Lu Xinxin; Zhu Tonghua

    2008-01-01

    The factors influencing detection efficiency of solid track spark auto counter were analyzed, and the best etch condition and parameters of charge were also reconfirmed. With small plate fission ionization chamber, the efficiency of solid track spark auto counter at various experiment assemblies was re-calibrated. The efficiency of solid track spark auto counter at various experimental conditions was obtained. (authors)

  19. Counter-responses as organizers in adolescent analysis and therapy.

    Science.gov (United States)

    Richmond, M Barrie

    2004-01-01

    The author introduces Counter-response as a phenomological term to replace theory-burdened terms like counter-transference, counter-identification, and counter-resistance. He discusses the analyst's use of self (drawing on the comparison with Winnicott's use of the object) in processing the expectable destabilizing counter-reactions that occur in working therapeutically with disturbed adolescents and their parents. Further; he discusses the counter-reaction to the patient's narrative, acting-out, and how re-enactments can serve as an organizer for understanding the patient's inner life when the analyst formulates his/her counter-response. Emphasis is placed on the therapist forming his or her own narrative with the adolescent that takes into account the evoked counter-reaction. For this purpose, the author recommends the use of a combined counter-response and metaphor-orienting perspective to acknowledge and work with the denial, illusions, reversal of perspective, and catastrophic anxieties experienced with these adolescents. The counter-response perspective permits the emergence of the disturbed adolescent's novel narrative; however, since these experiences can be destabilizing or disruptive, the author also recommends the use of a personal metaphor to anticipate the reluctance to examining, processing, and formulating the analyst's dysphoric counter-reaction. With the use of the counter-response, the analyst's therapeutic ideal is to achieve a more optimal balance between using accepted narrative theories and exploring novel enactment experiences. His swimming metaphor stratagem is designed to keep the analyst in these difficult encounters.

  20. Generalization of the development of liquid-sparkling counter

    International Nuclear Information System (INIS)

    Bian Zhengzhu; Zhang Jue; Zhang Jinwei

    2006-01-01

    This paper includes five parts. It not only reviews the development history of liquid-sparkling counter but refers that the appearance of coincident circuit is its milestone. The paper summarizes the resembled hard ware and soft ware and soft ware of liquid-sparkling counter of indoor and overseas, and prospects the development of liquid-sparkling counter in our country. (authors)

  1. Current profile evolution during fast wave current drive on the DIII-D tokamak

    International Nuclear Information System (INIS)

    Petty, C.C.; Forest, C.B.; Baity, F.W.

    1995-06-01

    The effect of co and counter fast wave current drive (FWCD) on the plasma current profile has been measured for neutral beam heated plasmas with reversed magnetic shear on the DIII-D tokamak. Although the response of the loop voltage profile was consistent with the application of co and counter FWCD, little difference was observed between the current profiles for the opposite directions of FWCD. The evolution of the current profile was successfully modeled using the ONETWO transport code. The simulation showed that the small difference between the current profiles for co and counter FWCD was mainly due to an offsetting change in the o at sign c current proffie. In addition, the time scale for the loop voltage to reach equilibrium (i.e., flatten) was found to be much longer than the FWCD pulse, which limited the ability of the current profile to fully respond to co or counter FWCD

  2. A new neutron counter for fission research

    Energy Technology Data Exchange (ETDEWEB)

    Laurent, B., E-mail: benoit.laurent@cea.fr [CEA, DAM, DIF, F-91297 Arpajon (France); Granier, T.; Bélier, G.; Chatillon, A.; Martin, J.-F.; Taieb, J. [CEA, DAM, DIF, F-91297 Arpajon (France); Hambsch, F.-J. [EC-JRC Institute for Reference Materials and Measurements (IRMM), Retieseweg, 2440 Geel (Belgium); Tovesson, F.; Laptev, A.B.; Haight, R.C.; Nelson, R.O.; O' Donnell, J.M. [Los Alamos Neutron Science Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2014-05-01

    A new neutron counter for research experiments on nuclear fission has been developed. This instrument is designed for the detection of prompt fission neutrons within relatively high levels of gamma and neutron background. It is composed of a set of {sup 3}He proportional counters arranged within a block of polyethylene which serves as moderator. The detection properties have been studied by means of Monte Carlo simulations and experiments with radioactive sources. These properties are confirmed by an experiment on neutron-induced fission of {sup 238}U at the WNR facility of the Los Alamos Neutron Science Center during which the mean prompt fission neutron multiplicity, or ν{sup ¯} has been measured from 1 to 20 MeV of incident neutron energy.

  3. Dead zone characteristics of a gas counter

    International Nuclear Information System (INIS)

    Nohtomi, Akihiro; Sakae, Takeji; Matoba, Masaru; Koori, Norihiko.

    1990-01-01

    The dead zone was recently defined as the product of dead length and dead time in order to describe the characteristics of the self-quenching streamer (SQS) mode of a gas counter. Investigation of the dead zone characteristics has been extended for the proportional and GM modes, and the measured dead zone has been compared with that of the SQS mode. Accurate values for the dead zone could be determined by means of a newly developed method with a pulse interval time to amplitude converter. Each operation mode indicates distinct dead zone characteristics. Properties of gas counters for high counting rates may be improved on the basis of measurements of the dead zone. (author)

  4. Pulse triggering mechanism of air proportional counters

    International Nuclear Information System (INIS)

    Aoyama, T.; Mori, T.; Watanabe, T.

    1983-01-01

    This paper describes the pulse triggering mechanism of a cylindrical proportional counter filled with air at atmospheric pressure for the incidence of β-rays. Experimental results indicate that primary electrons created distantly from the anode wire by a β-ray are transformed into negative ions, which then detach electrons close to the anode wire and generate electron avalanches thus triggering pulses, while electrons created near the anode wire by a β-ray directly trigger a pulse. Since a negative ion pulse is triggered by a single electron detached from a negative ion, multiple pulses are generated by a large number of ions produced by the incidence of a single β-ray. It is therefore necessary not to count pulses triggered by negative ions but to count those by primary electrons alone when use is made of air proportional counters for the detection of β-rays. (orig.)

  5. Sources of Brazil's Counter-Hegemony

    Directory of Open Access Journals (Sweden)

    Marcos Aurelio Guedes de Oliveira

    2010-01-01

    Full Text Available There have been two key initiatives taken in the last two decades in Brazil to create a counter-hegemonic project for the country. One initiative resulted from Brazil's business community and high-level State bureaucracy and aimed at forming a regional economic and political bloc that would guarantee and enlarge a relative independence from the hegemonic powers. The other resulted from the emergence of the new unionist movement in São Paulo and from the formation of Partido dos Trabalhadores and aimed at promoting radical democratization and reducing social exclusion. Both initiatives have created policies and changes that have converged to enhance Brazil's counter-hegemonic position as a regional and emerging power.

  6. Very large area multiwire spectroscopic proportional counters

    International Nuclear Information System (INIS)

    Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F.

    1981-01-01

    As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) succesfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm 2 with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results. (orig.)

  7. Very large area multiwire spectroscopic proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F. (Istituto di Astrofisica Spaziale, Frascati (Italy))

    1981-07-01

    As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) successfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm/sup 2/ with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results.

  8. Calibration of the neutron scintillation counter threshold

    International Nuclear Information System (INIS)

    Noga, V.I.; Ranyuk, Yu.N.; Telegin, Yu.N.

    1978-01-01

    A method for calibrating the threshold of a neutron counter in the form of a 10x10x40 cm plastic scintillator is described. The method is based on the evaluation of the Compton boundary of γ-spectrum from the discrimination curve of counter loading. The results of calibration using 60 Co and 24 Na γ-sources are given. In order to eValuate the Compton edge rapidly, linear extrapolation of the linear part of the discrimination curve towards its intersection with the X axis is recommended. Special measurements have shown that the calibration results do not practically depend on the distance between the cathode of a photomultiplier and the place where collimated γ-radiation of the calibration source reaches the scintillator

  9. Engaging Civil Society in Countering Violent Extremism

    Directory of Open Access Journals (Sweden)

    Bibi van Ginkel

    2012-08-01

    Full Text Available In this Research Paper Dr. Bibi van Ginkel takes an in depth look at how multi-lateral institutions, engage with civil society to counter violent extremism. Dr. van Ginkel argues that civil society can play a crucial role in preventing and countering violent extremism in numerous ways – by working on development programs, through their work in conflict transformation, in providing a platform to raise political grievances and to facilitate dialogue, or through their work in empowering victims and survivors of terrorism. The Paper finds that over the last decade there has been a more intensive coordination of activities between the UN and other multi-lateral organisations and civil society but the question remains whether the implementation as well as the drafting of these policies will live up to their potential effectiveness. This Paper gauges how effective these measures have been and what more there is to do. The final section concludes with a series of policy recommendations.

  10. Prevent, Counter, and Respond - A Strategic Plan to Reduce Global Nuclear Threats (FY 2016-FY2020)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-03-01

    NNSA’s second core mission is reducing global nuclear dangers by preventing the acquisition of nuclear weapons or weapons-usable materials, countering efforts to acquire such weapons or materials, and responding to nuclear or radiological incidents. In 2015, NNSA reorganized its nonproliferation activities based on core competencies and realigned its counterterrorism and counterproliferation functions to more efficiently address both current and emerging threats and challenges. The reorganization accompanied the March 2015 release of the first ever Prevent, Counter, and Respond – A Strategic Plan to Reduce Global Nuclear Threats. This report, which NNSA will update annually, highlights key nuclear threat trends and describes NNSA’s integrated threat reduction strategy.

  11. Fast differential pulse discriminator-counter

    International Nuclear Information System (INIS)

    Shelevoj, K.D.

    1985-01-01

    The flowsheet of a differential pulse discriminator counter is described; the result of discrimination here is independent from the shape of the input pulse. Rate of the analysis of input pulses with minimum amplitude up to 0.3 mV coming out from the photomultiplier makes up 220 MHz. The flowsheet of the discriminator used in the system of photon counting for atmosphere probing is presented

  12. A position sensitive parallel plate avalanche counter

    International Nuclear Information System (INIS)

    Lombardi, M.; Tan Jilian; Potenza, R.; D'amico, V.

    1986-01-01

    A position sensitive parallel plate avalanche counter with a distributed constant delay-line-cathode (PSAC) is described. The strips formed on the printed board were served as the cathode and the delay line for readout of signals. The detector (PSAC) was operated in isobutane gas at the pressure range from 10 to 20 torr. The position resolution is better than 1 mm and the time resolution is about 350 ps, for 252 Cf fission-spectrum source

  13. Evaluating the US Counter-ISIL Strategy

    Science.gov (United States)

    2017-05-25

    strategy is actually addressing those critical capabilities and vulnerabilities. Finally, it explores alternative, whole-of-government strategies that...Counterterrorism Strategies as an Illustration. Santa Monica, CA: RAND Corporation , 2009. Enduring Leadership in a Dynamic World. Quadrennial Diplomacy...Evaluating the US Counter-ISIL Strategy A Monograph by LTC Jason A. Curl U.S. Army School of Advanced Military Studies United States Army

  14. Universal Fast Breeder Reactor Subassembly Counter manual

    International Nuclear Information System (INIS)

    Menlove, H.O.; Eccleston, G.W.; Swansen, J.E.; Goris, P.; Abedin-Zadeh, R.; Ramalho, A.

    1984-08-01

    A neutron coincidence counter has been designed for the measurement of fast breeder reactor fuel assemblies. This assay system can accommodate the full range of geometries and masses found in fast breeder subassemblies under IAEA safeguards. The system's high-performance capability accommodates high plutonium loadings of up to 16 kg. This manual describes the system and its operation and gives performance and calibration parameters for typical applications

  15. Universal Fast Breeder Reactor Subassembly Counter manual

    Energy Technology Data Exchange (ETDEWEB)

    Menlove, H.O.; Eccleston, G.W.; Swansen, J.E.; Goris, P.; Abedin-Zadeh, R.; Ramalho, A.

    1984-08-01

    A neutron coincidence counter has been designed for the measurement of fast breeder reactor fuel assemblies. This assay system can accommodate the full range of geometries and masses found in fast breeder subassemblies under IAEA safeguards. The system's high-performance capability accommodates high plutonium loadings of up to 16 kg. This manual describes the system and its operation and gives performance and calibration parameters for typical applications.

  16. Development of aerogel Cherenkov counters at Novosibirsk

    International Nuclear Information System (INIS)

    Barnyakov, A.Yu.; Barnyakov, M.Yu.; Baehr, J.; Bellunato, T.; Beloborodov, K.I.; Bobrovnikov, V.S.; Buzykaev, A.R.; Calvi, M.; Danilyuk, A.F.; Djordjadze, V.; Golubev, V.B.; Kononov, S.A.; Kravchenko, E.A.; Lipka, D.; Matteuzzi, C.; Musy, M.; Onuchin, A.P.; Perego, D.; Rodiakin, V.A.; Savinov, G.A.; Serednyakov, S.I.; Shamov, A.G.; Stephan, F.; Tayursky, V.A.; Vorobiov, A.I.

    2006-01-01

    The work on aerogel Cherenkov counters was started in Novosibirsk in 1986. Production of aerogels with refractive indices of 1.006-1.13 and thicknesses of blocks up to 50mm was developed. The light absorption length at 400nm is 5-7m, the scattering length is 4-5cm. By these parameters, the Novosibirsk aerogel is one of the best in the world. The ASHIPH Cherenkov counters with light collection on wavelength shifters have been developed. The ASHIPH system of the KEDR detector contains 1000l of aerogel. The π/K separation is 4.5σ. A project of ASHIPH counters for the SND detector has been developed. Aerogel RICH for LHCb gives a possibility to identify hadrons in the momentum range of 2-10GeV/c. The Novosibirsk group is developing an aerogel RICH for the endcap for the SuperBaBar project. Calculations performed by a group of physicists from Novosibirsk and DESY-Zeuthen have shown that aerogel radiators enable to achieve time resolution up to 20fs

  17. Which future for nuclear counter-proliferation?

    International Nuclear Information System (INIS)

    Duval, M.

    2010-01-01

    Dealing with the case of nuclear weapons possessed by nuclear states (but not eventually by terrorists), the author first identifies the constants of counter-proliferation: it is linked to interest conflicts between those who try to preserve their monopoly and those who try to acquire a new weapon either because of a threat or for reasons of regional prestige, the evolution from use to deterrence, the appearance of new actors after the USA and Russia, the role of nuclear tactical weapons, and the future of Russian weapons and know-how. He presents the international counter-proliferation context: the Non Proliferation Treaty (NPT), the IAEA and its controls, the Nuclear Supplier Group (NSG), the nuclear-free zones, the Comprehensive Test Ban Treaty (CTBT), the Missile Technology Control Regime (MTCR). He describes how and why proliferation occurs: uranium enrichment and plutonium technology, political reasons in different parts of the world. Then, he gives an overview of the proliferation status by commenting the cases of Israel, Iraq, India, Pakistan, North Korea, and Iran. He discusses the future of proliferation (involved countries, existence of a nuclear black market) and of counter-proliferation as far as Middle-East and North Korea are concerned. He tries finally to anticipate the consequences for nuclear deterrence strategy, and more particularly for Europe and France

  18. High speed non-latching squid binary ripple counter

    International Nuclear Information System (INIS)

    Silver, A.H.; Phillips, R.R.; Sandell, R.D.

    1985-01-01

    High speed, single flux quantum (SFQ) binary scalers are important components in superconducting analog-to-digital converters (ADC). This paper reviews the concept for a SQUID ADC and the design of an SFQ binary ripple counter, and reports the simulation of key components, and fabrication and performance of non-latching SQUID scalers and SFQ binary ripple counters. The SQUIDs were fabricated with Nb/Nb 2 O 5 /PbIn junctions and interconnected by monolithic superconducting transmission lines and isolation resistors. Each SQUID functioned as a bistable flip-flop with the input connected to the center of the device and the output across one junction. All junctions were critically damped to optimize the pulse response. Operation was verified by observing the dc I-V curves of successive SQUIDs driven by a cw pulse train generated on the same chip. Each SQUID exhibited constant-voltage current steps at 1/2 the voltage of the preceding device as expected from the Josephson voltage-to-frequency relation. Steps were observed only for the same voltage polarity of successive devices and for proper phase bias of the SQUID. Binary frequency division was recorded up to 40GHz for devices designed to operate to 28GHz

  19. A multi purpose 4 π counter spherical ionization chamber type

    International Nuclear Information System (INIS)

    Calin, Marian Romeo; Calin, Adrian Cantemir

    2004-01-01

    A pressurized ionization chamber detector able to measure radioactive sources in internal 2π or 4π geometry was built in order to characterize alpha and beta radioactive sources, i.e. to calibrate these sources by relative method and to test the behavior of gas mixtures in pressurized-gas radiation detectors. The detector we made is of spherical shape and works by collecting in a uniform electric field the ionization charges resulting from the interaction of ionizing radiation with gas in the sensitive volume of the chamber. An ionizing current proportional to the activity of the radioactive source to be measured is obtained. In this paper a gas counter with a spherical symmetry is described. This detector can work in a very satisfactory manner, either as a flow counter or as a ionization chamber reaching in the latter case a good α pulse height resolution, even with large emitting sources. Calculations are made in order to find the dependence of the pulse shape on the direction of emission of an α-particle by a point source in the chamber (finite track). A good agreement is found between these calculations and the experimental tests performed, which show that this dependence can be employed in high efficiency measurements of angular α-γ correlations. (authors)

  20. Online De-Radicalization? Countering Violent Extremist Narratives: Message, Messenger and Media Strategy

    Directory of Open Access Journals (Sweden)

    Omar Ashour

    2011-01-01

    Full Text Available Is “online de-radicalization” possible? Given the two growing phenomena of “online radicalization” and “behavioral/ideological/organizational de-radicalization,” this article outlines a broad strategy for countering the narratives of violent extremists. It argues that an effective counter-narrative should be built on three pillars. The first is an effective comprehensive message that dismantles and counter-argues against every dimension of the extremist narrative, namely the theological, political, historical, instrumental and socio-psychological dimensions. The second pillar is the messengers. The article argues that for the first time in the history of Jihadism a “critical mass” of former militants, who rebelled not only against the current behaviour of their former colleagues but also against the ideology supporting it, has come into existence. This “critical mass” can constitute the core of credible messengers, especially the few de-radicalized individuals and groups that still maintain influence and respect among vulnerable communities. The third pillar is the dissemination and attraction strategy of the counter-narratives(s which focuses on the role of the media. The author of the article outlines a broad framework, which is a part of a UN-sponsored, comprehensive research project on countering the extremists narrative.

  1. Expertise in unexpected places: Children's acceptance of information from gender counter-stereotypical experts.

    Science.gov (United States)

    Boseovski, Janet J; Hughes, Chelsea; Miller, Stephanie E

    2016-01-01

    The current study examined children's willingness to accept novel information from expert informants with nontraditional gender role interests. Four- to 8-year-olds heard conflicting information about traditionally feminine or masculine domains from a gender counter-stereotypical expert (e.g., a boy with expertise in ballet) and a layperson of the other gender (e.g., a girl with little knowledge about ballet). Participants were asked which informant was correct, who they would prefer to learn from in the future, and to rate their liking of each informant. Overall, participants selected the gender counter-stereotypical expert as correct. Four- to 5-year-olds reported a preference to learn from same-gender participants in the future irrespective of expertise, whereas 6- to 8-year-olds reported wanting to learn from counter-stereotypical experts. Boys showed relatively greater acceptance of information from a male counter-stereotypical expert than from a female counter-stereotypical expert. Although participants reported greater liking of same-gender informants, liking evaluations were largely positive irrespective of gender norm deviations. Implications for children's acceptance of gender nonconforming activities are discussed. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. CAMAC-system for calibration and control of experimental apparatus with scintillation counters

    International Nuclear Information System (INIS)

    Petrov, A.G.; Sinaev, A.N.

    1977-01-01

    The CAMAC-system is described, connected to the minicomputer PH-2116C, for calibration and control of an experiment on pion scattering on He-nuclei performed with a streamer chamber triggered by a scintillation hodoscope. The following operations are performed: -delay calibration in telescope and hodoscope tracts involving 22 scintillation counters; -control of relative efficiency of hodoscope counters and other parameters of the experiments; -control of HV supply of photomultipliers; -control of the currents of magnets and lenses of the muon track of the synchrocyclotron; -measurement of pulse-hight spectra from a Cherenkov counter to determine the beam composition. The working programs are initiated and the dialogue with the computer is carried out using an alphanumerical display connected to the PH-2116C via a CAMAC interface

  3. Calibration of Single High Purity Germanium Detector for Whole Body Counter

    International Nuclear Information System (INIS)

    Taha, T.M.; Morsi, T.M.

    2009-01-01

    A new Accuscan II single germanium detector for whole body counter was installed in NRC (Egypt). The current paper concerned on calibration of single high purity germanium detector for whole body counter. Physical parameters affecting on performance of whole body counter such as linearity, minimum detectable activity and source detector distance, SDD were investigated. Counting efficiencies for the detector have been investigated in rear wall, fixed diagnostic position in air. Counting efficiencies for organ compartments such as thyroid, lung, upper and lower gastrointestinal tract have been investigated using transfer phantom in fixed diagnostic and screening positions respectively. The organ compartment efficiencies in screening geometry were higher than that value of diagnostic geometry by a factor of three. The committed dose equivalents of I-131 in thyroid were ranged from 0.073 ± 0.004 to 1.73±0.09 mSv and in lung was 0.02±0.001 mSv

  4. Charge transport and magnetoresistance of G4-DNA molecular device modulated by counter ions and dephasing effect

    International Nuclear Information System (INIS)

    Kang, Da-wei; Sun, Meng-le; Zuo, Zheng-wei; Wang, Hui-xian; Lv, Shi-jie; Li, Xin-zhong; Li, Li-ben

    2016-01-01

    The charge transport properties of the G4-DNA molecular device in the presence of counter ions and dephasing effect are investigated based on the Green function method and Landauer–Büttiker theory. The currents through the G4-DNA molecular device depend on the interference patterns at different coupling configurations. There is an effective electrostatic interaction between the counter ions and the G4-DNA molecule which introduces disorder into the on-site energies of G bases. The current through the device can be enhanced by the small disorder which avoids the strong interference of electrons at the same energy in some coupling configurations, however the diagonal disorder can suppress the overall current due to the Anderson localization of charge carriers when the disorder is large. In the presence of dephasing effect the current through the device at all coupling configurations can be enhanced as a result of the phase coherence losing of electron. As for the magnetic field response, the magnetoresistance of the device is always suppressed by the counter ions and dephasing effect. - Highlights: • The counter ions can some times enhance the current through G4-DNA molecule. • The dephasing effect can enhance the current of the device at all four coupling configurations. • The magnetoresistance is always suppressed by the counter ions and dephasing effect.

  5. Hardware support for software controlled fast multiplexing of performance counters

    Science.gov (United States)

    Salapura, Valentina; Wisniewski, Robert W.

    2013-01-01

    Performance counters may be operable to collect one or more counts of one or more selected activities, and registers may be operable to store a set of performance counter configurations. A state machine may be operable to automatically select a register from the registers for reconfiguring the one or more performance counters in response to receiving a first signal. The state machine may be further operable to reconfigure the one or more performance counters based on a configuration specified in the selected register. The state machine yet further may be operable to copy data in selected one or more of the performance counters to a memory location, or to copy data from the memory location to the counters, in response to receiving a second signal. The state machine may be operable to store or restore the counter values and state machine configuration in response to a context switch event.

  6. Counter-Productive Counter-Terrorism. How is the dysfunctional discourse of Prevent failing to restrain radicalisation?

    Directory of Open Access Journals (Sweden)

    Lauren Powell

    2016-09-01

    Full Text Available This paper explores why the Prevent strand of the UK Government’s counter-terrorism strategy, CONTEST, is failing to achieve success in reducing radicalisation of young Muslims. By refusing to engage with extremists, and denying ‘extreme’ ideas a platform for expression, this paper will explain how the importance of cultural-linguistic epistemologies, and their role in extremism, has been overlooked. Rather than striving to understand how socio-political factors influence one’s reading of religious doctrines or interpretation of ideology, Prevent understands ideology to be the core radicalising agent, used by influential figures who can exploit the grievances of the vulnerable. The problematic repercussions of this will be addressed throughout, highlighting the various, and extensive, criticisms that Prevent has faced from academics, practitioners and commentators – primarily that it is counter-productive. The importance of the post-9/11 neoconservative paradigm in underpinning Prevent will be explained, but a Neo-Weberian approach, as a better lens through which to understand radicalisation, will be proposed, to ultimately trump the simplistic, yet currently dominant, ‘Conveyor Belt’ theory. Based on this, recommendations are made for an improved Prevent, rooted in the notion that radicalisation, extremism, or terrorism cannot be prevented, without knowing the motives, the views, and the assumptions of the radicals, the extremists, and those vulnerable to engaging with them.

  7. Consumer Preferences for High Welfare Meat in Germany: Self-service Counter or Service Counter?

    Directory of Open Access Journals (Sweden)

    Ramona Weinrich

    2015-01-01

    Full Text Available Many people view animal welfare standards in the agricultural industry as critical and some consumers would prefer to buy high welfare meat. In order to successfully introduce high welfare meat products onto the market, some important marketing decisions must be made. Due to limited shelf space in retail outlets, niche products like high welfare meat cannot be placed both at the self-service counter and at the service counter. In order to analyze where to place it best an online survey of 642 German consumers was conducted. By means of factor and cluster analyses, consumers’ animal welfare attitudes and their preference for a point of purchase were combined. The different target groups were joint using cross tabulation analysis. The results reveal that consumers in the target group show a more positive attitude to the service counter.

  8. Advanced Prop-fan Engine Technology (APET) single- and counter-rotation gearbox/pitch change mechanism

    Science.gov (United States)

    Reynolds, C. N.

    1985-01-01

    The preliminary design of advanced technology (1992) turboprop engines for single-rotation prop-fans and conceptual designs of pitch change mechanisms for single- and counter-rotation prop-fan application are discussed. The single-rotation gearbox is a split path, in-line configuration. The counter-rotation gearbox is an in-line, differential planetary design. The pitch change mechanisms for both the single- and counter-rotation arrangements are rotary/hydraulic. The advanced technology single-rotation gearbox yields a 2.4 percent improvement in aircraft fuel burn and a one percent improvement in operating cost relative to a current technology gearbox. The 1992 counter-rotation gearbox is 15 percent lighter, 15 percent more reliable, 5 percent lower in cost, and 45 percent lower in maintenance cost than the 1992 single-rotation gearbox. The pitch controls are modular, accessible, and external.

  9. Counter-Narratives and the Unrehearsed Stories Counter-Terrorists Unwittingly Produce

    Directory of Open Access Journals (Sweden)

    Beatrice de Graaf

    2010-11-01

    Full Text Available Governments produce both deliberate and involuntary (and less conscious narratives when countering terrorism. The thesis of this article is that such unintended messages can be much more powerful and consequential than is realized; in fact, they can completely contradict the intended official 'counter-narrative'. To substantiate this hypothesis, the author looks at the experience of the German Federal Republic in the 1970s and beyond when state and society were confronted with the Red Army Faction (RAF and similar left-wing "revolutionaries" like those of the 2nd of June Movement or the Red Zora.

  10. Opium and Afghanistan: Reassessing U.S. Counter-Narcotics Strategy

    Science.gov (United States)

    2007-03-30

    and effective governance of Afghanistan.”3 This paper examines the nature of the opium problem in Afghanistan and analyzes the current strategy to...Opium is also refined for use in legal prescription painkillers such as OxyContin and Vicodin.14 However, Australia and France currently produce about...is simply inadequate to carry out an effective counter-narcotics campaign. While some regions of Afghanistan are relatively stable and free of

  11. Taxing Junk Food to Counter Obesity

    Science.gov (United States)

    Franck, Caroline; Grandi, Sonia M.

    2013-01-01

    We examined the advantages and disadvantages of implementing a junk food tax as an intervention to counter increasing obesity in North America. Small excise taxes are likely to yield substantial revenue but are unlikely to affect obesity rates. High excise taxes are likely to have a direct impact on weight in at-risk populations but are less likely to be politically palatable or sustainable. Ultimately, the effectiveness of earmarked health programs and subsidies is likely to be a key determinant of tax success in the fight against obesity. PMID:24028245

  12. Rate dependent image distortions in proportional counters

    International Nuclear Information System (INIS)

    Trow, M.W.; Bento, A.C.; Smith, A.

    1994-01-01

    The positional linearity of imaging proportional counters is affected by the intensity distribution of the incident radiation. A mechanism for this effect is described, in which drifting positive ions in the gas produce a distorting electric field which perturbs the trajectories of the primary electrons. In certain cases, the phenomenon causes an apparent improvement of the position resolution. We demonstrate the effect in a detector filled with a xenon-argon-CO 2 mixture. The images obtained are compared with the results of a simulation. If quantitative predictions for a particular detector are required, accurate values of the absolute detector gain, ion mobility and electron drift velocity are needed. ((orig.))

  13. Industrial espionage and technical surveillance counter measurers

    CERN Document Server

    Androulidakis, Iosif

    2016-01-01

    This book examines technical aspects of industrial espionage and its impact in modern companies, organizations, and individuals while emphasizing the importance of intellectual property in the information era. The authors discuss the problem itself and then provide statistics and real world cases. The main contribution provides a detailed discussion of the actual equipment, tools and techniques concerning technical surveillance in the framework of espionage. Moreover, they present the best practices and methods of detection (technical surveillance counter measures) as well as means of intellectual property protection.

  14. Taxing junk food to counter obesity.

    Science.gov (United States)

    Franck, Caroline; Grandi, Sonia M; Eisenberg, Mark J

    2013-11-01

    We examined the advantages and disadvantages of implementing a junk food tax as an intervention to counter increasing obesity in North America. Small excise taxes are likely to yield substantial revenue but are unlikely to affect obesity rates. High excise taxes are likely to have a direct impact on weight in at-risk populations but are less likely to be politically palatable or sustainable. Ultimately, the effectiveness of earmarked health programs and subsidies is likely to be a key determinant of tax success in the fight against obesity.

  15. Cerenkov counter for the experiment NA3

    CERN Multimedia

    1978-01-01

    The program of the NA3 experiment included the study of hadronic interactions with a large transverse momentum pT, thus the inclusion in the set-up of three gas threshold Cerenkov counters of large acceptance. The photo shows the downstream part of the second Cerenkov (located at the output of the magnet). The yellow membrane is a temporary protection for the optics (shown in photo 7810540X) to be taken away when fixing this part to the gas tank (entering the magnet and not shown). The photomultipliers all around are heavily shielded.

  16. Use of parallel counters for triggering

    International Nuclear Information System (INIS)

    Nikityuk, N.M.

    1991-01-01

    Results of investigation of using parallel counters, majority coincidence schemes, parallel compressors for triggering in multichannel high energy spectrometers are described. Concrete examples of methods of constructing fast and economic new devices used to determine multiplicity hits t>900 registered in a hodoscopic plane and a pixel detector are given. For this purpose the author uses the syndrome coding method and cellular arrays. In addition, an effective coding matrix has been created which can be used for light signal coding. For example, such signals are supplied from scintillators to photomultipliers. 23 refs.; 21 figs

  17. Governmentality, Counter-conduct and Prefigurative Demonstrations

    DEFF Research Database (Denmark)

    McIlvenny, Paul

    2016-01-01

    This chapter attends to the micro-ethnographic detail of actual practices, procedures and technologies – the techne – of governance, especially those practices that manifest as what Foucault called ‘counter-conducts’. The interactional and categorial practices of a prefigurative protest demonstra......This chapter attends to the micro-ethnographic detail of actual practices, procedures and technologies – the techne – of governance, especially those practices that manifest as what Foucault called ‘counter-conducts’. The interactional and categorial practices of a prefigurative protest...... demonstration are examined using video recordings that were made of a theatrical protest event called “United Nathans weapons inspections” in February 2003. The chapter draws upon Mitchell Dean’s analytics of government and Carl Death’s analytics of protest. A first step in an analytics of protest is to uncover...... how fields of visibility, forms of knowledge, technologies and apparatuses, and subjectivities and identities are negotiated and accomplished collaboratively. Specific tools and methods that are well suited to investigating the situated practices, procedures and technologies of governmentality...

  18. 300-MHz optical discriminator-counter

    International Nuclear Information System (INIS)

    Turko, B.; Lo, C.C.

    1981-07-01

    The prediction of future CO 2 content in the atmosphere is not completely credible because the oceanographers and terrestrial ecologists do not agree on the global CO 2 balance. Very precise measurements of O 2 /N 2 ratio using Raman scattering over a few years' period could provide important information and lead to the explanation of the disparity in the atmospheric CO 2 balance. An optical discriminator-counter has been developed to count closely spaced optical events in the few photon level. Simulated optical events as close as 2.5 ns apart had been positively detected by using selected photomultipliers and optimized discriminators. Testing of the optical discriminator-counter was done by using an electrical pulse pair spaced 3 ns apart and also by a similar optical pulse pair generated by fast light-emitting diode. The photomultiplier is capable of counting an average single photoelectron pulse frequency of 50 MHz and has a sensitive detecting area of 50 mm in diameter. The discriminator performance is discussed

  19. Reduction of degraded events in miniaturized proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Plaga, R.; Kirsten, T. (Max Planck Inst. fuer Kernphysik, Heidelberg (Germany))

    1991-11-15

    A method to reduce the number of degraded events in miniaturized proportional counters is described. A shaping of the outer cathode leads to a more uniform gas gain along the counter axis. The method is useful in situations in which the total number of decay events is very low. The effects leading to degraded events are studied theoretically and experimentally. The usefulness of the method is demonstrated by using it for the proportional counter of the GALLEX solar neutrino experiment. (orig.).

  20. Construction and calibration studies of the SAPHIR scintillation counters

    International Nuclear Information System (INIS)

    Kostrewa, D.

    1988-03-01

    For the scintillation counter system of the SAPHIR detector at the stretcher ring ELSA in Bonn 50 time of flight counters and 12 trigger counters have been built. Each of them has two photomultipliers, one at each side. A laser calibration system with a pulsed nitrogen laser as central light source to monitor these photomultipliers has been optimized. It was used to adjust the photomultipliers and to test their long and short time instabilities. (orig.)

  1. Criticism and Counter-Criticism of Public Management: Strategy Models

    OpenAIRE

    Luis C. Ortigueira

    2007-01-01

    Critical control is very important in scientific management. This paper presents models of critical and counter-critical public-management strategies, focusing on the types of criticism and counter-criticism manifested in parliamentary political debates. The paper includes: (i) a normative model showing how rational criticism can be carried out; (ii) a normative model for oral critical intervention; and (iii) a general motivational strategy model for criticisms and counter-criticisms. The pap...

  2. Al Qaeda’s “Single Narrative” and Attempts to Develop Counter-Narratives

    Directory of Open Access Journals (Sweden)

    Alex P. Schmid

    2014-01-01

    Full Text Available In this Research Paper, Research Fellow Dr. Alex Schmid dissects the nature of Al Qaeda’s propaganda strategy by looking how it incorporates in its ideological narrative Islam’s sacred texts and traditions and how it manages to link these to widespread contemporary grievances in the Muslim world. Al Qaeda’s survival is tied to the credibility of its narrative “story” rather than the physical survival of its leadership. The Research Paper discusses mainly American and British efforts to challenge the integrative (hence: “single” narrative of Al Qaeda. Current counter-narratives often fall short of reaching objectives due to a lack of credibility – a result of the gap between official Western declaratory policies and actual policies on the ground. Efforts to sell “hearts and minds” products often floundered on policies that lack legitimacy or stood in stark contrast to professed values like adherence to human rights standards, thereby creating perceptions of double standards and hypocrisy. While Al Qaeda’s policies exhibit similar, and in some areas even greater, discrepancies between what is being said and what is being done, these have not been fully exploited. Following the discussion of governmental efforts to counter Al Qaeda’s narrative, findings and suggestions from academia, think tanks, religious scholars and others trying to counter Al Qaeda’s narrative are presented. While it is generally true that counter-narrative work is still in its infancy, the survey of various proposals and programs makes clear that important building blocks for a more creative effort of countering the ideological attraction of Al Qaeda exist. One of the problems with counter-narratives is their defensive and reactive nature and their focus on packaging messages. This paper emphasises the importance of crafting and spreading an alternative narrative. While counter-narratives have to aim at discrediting the exclusive narrative of Al Qaeda

  3. Hardware support for software controlled fast reconfiguration of performance counters

    Science.gov (United States)

    Salapura, Valentina; Wisniewski, Robert W.

    2013-06-18

    Hardware support for software controlled reconfiguration of performance counters may include a plurality of performance counters collecting one or more counts of one or more selected activities. A storage element stores data value representing a time interval, and a timer element reads the data value and detects expiration of the time interval based on the data value and generates a signal. A plurality of configuration registers stores a set of performance counter configurations. A state machine receives the signal and selects a configuration register from the plurality of configuration registers for reconfiguring the one or more performance counters.

  4. Neutron dosimetry using proportional counters with tissue equivalent walls

    International Nuclear Information System (INIS)

    Kerviller, H. de

    1965-01-01

    The author reminds the calculation method of the neutron absorbed dose in a material and deduce of it the conditions what this material have to fill to be equivalent to biological tissues. Various proportional counters are mode with walls in new tissue equivalent material and filled with various gases. The multiplication factor and neutron energy response of these counters are investigated and compared with those obtained with ethylene lined polyethylene counters. The conditions of working of such proportional counters for neutron dosimetry in energy range 10 -2 to 15 MeV are specified. (author) [fr

  5. Cosmic Ray Background Analysis For A Cargo Container Counter

    International Nuclear Information System (INIS)

    Ensslin, Norbert; Geist, W.H.; Lestone, J.P.; Mayo, D.R.; Menlove, Howard O.

    2001-01-01

    We have developed a new model for calculating the expected yield of cosmic-ray spallation neutrons in a Cargo Container Counter, and we have benchmarked the model against measurements made with several existing large neutron counters. We also developed two versions of a new measurement uncertainty prediction code based on Microsoft Excel spreadsheets. The codes calculate the minimum detectability limit for the Cargo Container Counter for either neutron singles or doubles counting, and also propagate the uncertainties associated with efficiency normalization flux monitors and cosmic ray flux monitors. This paper will describe the physics basis for this analysis, and the results obtained for several different counter designs.

  6. Citropin 1.1 Trifluoroacetate to Chloride Counter-Ion Exchange in HCl-Saturated Organic Solutions: An Alternative Approach.

    Science.gov (United States)

    Sikora, Karol; Neubauer, Damian; Jaśkiewicz, Maciej; Kamysz, Wojciech

    2018-01-01

    In view of the increasing interest in peptides in various market sectors, a stronger emphasis on topics related to their production has been seen. Fmoc-based solid phase peptide synthesis, although being fast and efficient, provides final products with significant amounts of trifluoroacetate ions in the form of either a counter-ion or an unbound impurity. Because of the proven toxicity towards cells and peptide activity inhibition, ion exchange to more biocompatible one is purposeful. Additionally, as most of the currently used counter-ion exchange techniques are time-consuming and burdened by peptide yield reduction risk, development of a new approach is still a sensible solution. In this study, we examined the potential of peptide counter-ion exchange using non-aqueous organic solvents saturated with HCl. Counter-ion exchange of a model peptide, citropin 1.1 (GLFDVIKKVASVIGGL-NH 2 ), for each solvent was conducted through incubation with subsequent evaporation under reduced pressure, dissolution in water and lyophilization. Each exchange was performed four times and compared to a reference method-lyophilization of the peptide from an 0.1 M HCl solution. The results showed superior counter-ion exchange efficiency for most of the organic solutions in relation to the reference method. Moreover, HCl-saturated acetonitrile and tert -butanol provided a satisfying exchange level after just one repetition. Thus, those two organic solvents can be potentially introduced into routine peptide counter-ion exchange.

  7. Ti Porous Film-Supported NiCo₂S₄ Nanotubes Counter Electrode for Quantum-Dot-Sensitized Solar Cells.

    Science.gov (United States)

    Deng, Jianping; Wang, Minqiang; Song, Xiaohui; Yang, Zhi; Yuan, Zhaolin

    2018-04-17

    In this paper, a novel Ti porous film-supported NiCo₂S₄ nanotube was fabricated by the acid etching and two-step hydrothermal method and then used as a counter electrode in a CdS/CdSe quantum-dot-sensitized solar cell. Measurements of the cyclic voltammetry, Tafel polarization curves, and electrochemical impedance spectroscopy of the symmetric cells revealed that compared with the conventional FTO (fluorine doped tin oxide)/Pt counter electrode, Ti porous film-supported NiCo₂S₄ nanotubes counter electrode exhibited greater electrocatalytic activity toward polysulfide electrolyte and lower charge-transfer resistance at the interface between electrolyte and counter electrode, which remarkably improved the fill factor, short-circuit current density, and power conversion efficiency of the quantum-dot-sensitized solar cell. Under illumination of one sun (100 mW/cm²), the quantum-dot-sensitized solar cell based on Ti porous film-supported NiCo₂S₄ nanotubes counter electrode achieved a power conversion efficiency of 3.14%, which is superior to the cell based on FTO/Pt counter electrode (1.3%).

  8. Fiber-Optic Monitoring System of Particle Counters

    Directory of Open Access Journals (Sweden)

    A. A. Titov

    2016-01-01

    Full Text Available The article considers development of a fiber-optic system to monitor the counters of particles. Presently, optical counters of particles, which are often arranged at considerable distance from each other, are used to study the saltation phenomenon. For monitoring the counters, can be used electric communication lines.However, it complicates and raises the price of system Therefore, we offered a fiber-optic system and the counter of particles, free from these shortcomings. The difference between the offered counter of particles and the known one is that the input of radiation to the counter and the output of radiation scattering on particles are made by the optical fibers, and direct radiation is entered the optical fiber rather than is delayed by a light trap and can be used for lighting the other counters thereby allowing to use their connection in series.The work involved a choice of the quartz multimode optical fiber for communication, defining the optical fiber and lenses parameters of the counter of particles, and a selection of the radiation source and the photo-detector.Using the theory of light diffraction on a particle, a measuring range of the particle sizes has been determined. The system speed has been estimated, and it has been shown that a range of communication can reach 200km.It should be noted that modulation noise of counters of particles connected in series have the impact on the useful signal. To assess the extent of this influence we have developed a calculation procedure to illustrate that with ten counters connected in series this influence on the signal-to-noise ratio will be insignificant.Thus, it has been shown that the offered fiber-optic system can be used for monitoring the counters of particles across the desertified territories. 

  9. Absolute calibration of TFTR helium proportional counters

    International Nuclear Information System (INIS)

    Strachan, J.D.; Diesso, M.; Jassby, D.; Johnson, L.; McCauley, S.; Munsat, T.; Roquemore, A.L.; Loughlin, M.

    1995-06-01

    The TFTR helium proportional counters are located in the central five (5) channels of the TFTR multichannel neutron collimator. These detectors were absolutely calibrated using a 14 MeV neutron generator positioned at the horizontal midplane of the TFTR vacuum vessel. The neutron generator position was scanned in centimeter steps to determine the collimator aperture width to 14 MeV neutrons and the absolute sensitivity of each channel. Neutron profiles were measured for TFTR plasmas with time resolution between 5 msec and 50 msec depending upon count rates. The He detectors were used to measure the burnup of 1 MeV tritons in deuterium plasmas, the transport of tritium in trace tritium experiments, and the residual tritium levels in plasmas following 50:50 DT experiments

  10. CWRU multiwire proportional counter readout system

    International Nuclear Information System (INIS)

    Bevington, P.R.; Leskovec, R.A.

    1977-01-01

    An electronic system is described which translates pulses from individual wires of multiwire proportional counters into binary addresses indicating the location of the wires in the chambers. The system combines a fast (<100 ns) serial scan of an event buffer with parallel encoding to provide fast transfer of addresses (250 ns per hit). The buffer has provision for disabling the input less than 40 ns after detection of an event to suppress recording of multiple hits caused by individual events. The encoder can digitize the address of every hit encountered or just the first addresses of contiguous hits. The system includes a coincidence trigger for determining whether timing criteria have been satisfied between chambers and with external devices. Events which do not meet the coincidence criteria are typically reset within 400 ns. The addresses are transferred to a computer interface through CAMAC modules. Multiple buffering permits further data acquisition during CAMAC transfer cycles. (Auth.)

  11. Fabrication of preamplifier for proportional counter

    International Nuclear Information System (INIS)

    Lotfi, Y.; Yazdanpanah, M.; Talebi, B.; Mohammadi, A.; Etaati, Gh.

    2002-01-01

    We have tried to describe techniques of preamplifier fabrication for proportional counter. At first electronic circuit of preamplifier has been analyzed by means of Or cad 9.1. Then we assembled the circuit. Thereafter essential and standard parameters of preamplifier has been measured and compared with foreign made one, according to IEEE standard method. (IEEE Std 301-1988) Specification for our preamplifier is: 1. Rise time of output plus: 25 nsec. 2. Fall time of output pulse: 50μ sec. 3. Charge sensitive: 46.3 mV/pc. 4. Average noise: 500 ion pair (rms) 5. Count R ate L imit: 9.14*10 10 Count/sec. 6. Resolution: %1.3 7. Spectrum of Bf3 detector to 300μ Ci Am-Be source for this preamplifier is the same as foreign one. On the Whole comparison of this preamplifier with the foreign one shows that their parameters similarity is about %95

  12. Efficiency simulation of long neutron counter

    International Nuclear Information System (INIS)

    Hu Qingyuan; Li Bojun; Zhang De; Guo Hongsheng; Wang Dong; Yang Gaozhao; Si Fenni; Liu Jian

    2008-01-01

    In order to achieve the high efficiency and uniform sensitivity for neutrons with widely different energies, the efficiency of long boron trifluoride proportional counter imbedded in polyethylene moderator was simulated by MCNP code. The result shows that detective efficiency would increase with increasing moderator radius and response curve at higher energy would be ameliorated through adjusting the thickness of front moderator. Also we calculated the relative efficiencies for different energy of a detector whose efficiencies were calibrated on an accelerator. The simulated efficiency for D-D neutrons (2.4 MeV) is 75% of the efficiency for D-T neutrons (14.1 MeV), which is approximately agreed with experimental data, 61%. The validity of the simulated model was proved by the consistent results between calculation and experiment data. (authors)

  13. Fast-neutron coincidence-counter manual

    International Nuclear Information System (INIS)

    Ensslin, N.; Atwell, T.L.; Lee, D.M.; Erkkila, B.; Marshall, R.S.; Morgan, A.; Shonrock, C.; Tippens, B.; Van Lyssel, T.

    1982-03-01

    The fast neutron counter (FNC) described in this report is a computer-based assay system employing fast-pulse counting instrumentation. It is installed below a glove box in the metal electrorefining area of the Los Alamos National Laboratory Plutonium Processing Facility. The instrument was designed to assay plutonium salts and residues from this process and to verify the mass of electrorefined metal. Los Alamos National Laboratory Groups Q-1, Q-3, and CMB-11 carried out a joint test and evaluation plan of this instrument between May 1978 and May 1979. The results of that evaluation, a description of the FNC, and operating instructions for further use are given in this report

  14. The multimodal argumentation of persuasive counter discourses

    DEFF Research Database (Denmark)

    Maier, Carmen Daniela

    The continuous interest in and concern with business communication can be detected in the way critical aspects of this kind of communication are represented and debated in a wide range of discourses in a wide range of contexts. Drawing upon a social semiotic perspective, this paper explores...... the persuasive counter discourse of Media Bites videos: http://griid.org/category/media-bites/. The videos are a part of GRIID organization’s efforts directed at revealing misleading communicative strategies employed in various business contexts. In these instructive videos, the viewers are made familiar...... the misleading strategies employed. The viewers are also instructed where else they can find information about these strategies and the consequences of misleading advertising discourse. The argumentation framework of the Media Bites videos is also persuasively articulated for engaging the viewers as active...

  15. CAMAC differential pulse discriminator-counter

    International Nuclear Information System (INIS)

    Tselikov, N.V.

    1987-01-01

    Differential pulse discriminator-counter for Moessbauer spectrometer is described. Input pulse setting into the channel is performed according to the following algorithm: the pulse is transmitted to the channel depending on the fact whether the preceding pulse has got to the discrimination window or not. The circuit does not contain delay lines, taking into account the delay of a signal from the upper level discriminator in relation to the lower level discriminator signal, which is connected with input pulse rise finite time, which in turn allows one to reduce the discriminator dead time up to the operation time of threshold circuits. The pulse counting rate is 150 MHz, input signal amplitude is ±3 V, dead time is 6 ns, delay time from input to output is 14 ns. The unit is made in CAMAC system

  16. Quality measurement by proportional counter with B

    International Nuclear Information System (INIS)

    Onizuka, Yoshihiko; Endo, Satoru; Tanaka, Kenichi

    2005-01-01

    The dosimetry of air and the tissue-equivalent phantom made of acryl are carried out by the tissue-equivalent proportional counter (TEPC) and TEPC with wall contained B, and both results were compared. The changes of quality with distance from the beam center are determined by the frequency mean renewal energy y F (y)and the dose mean renewal energy y D (y) as indicators of quality. Both y F (y)and y D (y) of tissue-equivalent phantom are larger than air, but very large change was not observed in all distance. The dose rate is determined by y D (y), the number of events and measurement time. Change of dose rate was larger than the change of quality. The maximum value of dose rate depended on γray and neutron beam showed at the point 2 cm away from the center. (S.Y.)

  17. China's Cyber Initiatives Counter International Pressure

    Directory of Open Access Journals (Sweden)

    Emilio Iasiello

    2017-03-01

    Full Text Available Prior to its historic 2015 “no hack” pact for commercial advantage with the United States, Beijing has been engaged drafting and passing legislation, most with specific cyber components, to enhance its security posture while protecting its economic interests. This approach is in stark contrast to United States efforts that have demonstrated a focus on “acting globally, thinking locally” philosophy wherein most of its cyber efforts have been outwardly facing and are distinct from other security considerations. This paper suggests that by strengthening its domestic front with a legal framework, Beijing is preparing itself to counter any foreign initiative contrary to Beijing’s plans (e.g., cyber norms of behavior, cyber sanctions, etc. by being able to exert legal measures against foreign interests in country, thereby preserving its cyber sovereignty.

  18. Paid counter-advertising: proven strategy to combat tobacco use and promotion.

    Science.gov (United States)

    Blum, A

    1994-01-01

    This article discusses the effectiveness of paid counter-advertising in combating tobacco use and promotion, the impact of the Fairness Doctrine, which mandated anticigarette television advertisements in the late 1960s, and reasons why the media today are reluctant to run antismoking advertisements. Although counter-advertisements can work very well, they should be image-based, rather than fact-based. Currently, tobacco companies promote a positive image of cigarette smoking and brand awareness. Most antismoking ads, however, tend to focus on the tobacco itself and its adverse effects on the smoker, rather than combating the images the cigarette ads promote. Urging counter-advertising to focus on the product, rather than to try to produce guilt in smokers, this article provides examples of paid counter-advertising strategies employed by Doctors Ought to Care to illustrate an image-based approach. Overall, the antismoking movement must guard against complacency and measure its success according to tobacco companies' declining revenues, rather than the number of public service advertisements in the media.

  19. MicroRNA-Mediated Gene Silencing in Plant Defense and Viral Counter-Defense

    Directory of Open Access Journals (Sweden)

    Sheng-Rui Liu

    2017-09-01

    Full Text Available MicroRNAs (miRNAs are non-coding RNAs of approximately 20–24 nucleotides in length that serve as central regulators of eukaryotic gene expression by targeting mRNAs for cleavage or translational repression. In plants, miRNAs are associated with numerous regulatory pathways in growth and development processes, and defensive responses in plant–pathogen interactions. Recently, significant progress has been made in understanding miRNA-mediated gene silencing and how viruses counter this defense mechanism. Here, we summarize the current knowledge and recent advances in understanding the roles of miRNAs involved in the plant defense against viruses and viral counter-defense. We also document the application of miRNAs in plant antiviral defense. This review discusses the current understanding of the mechanisms of miRNA-mediated gene silencing and provides insights on the never-ending arms race between plants and viruses.

  20. X-ray proportional counter for the Viking Lander

    International Nuclear Information System (INIS)

    Glesius, F.L.; Kroon, J.C.; Castro, A.J.; Clark, B.C.

    1978-01-01

    A set of four sealed proportional counters with optimized energy response is employed in the X-ray fluorescence spectrometer units aboard the two Viking Landers. The instruments have provided quantitative elemental analyses of soil samples taken from the Martian surface. This paper discusses the design and development of these miniature proportional counters, and describes their performance on Mars

  1. Output pulse height distribution of the GM counters

    International Nuclear Information System (INIS)

    Zhang Songshou; Xiong Jianping

    1995-01-01

    The GM counters are the radiation detectors most in use. It has special advantages compared with other detectors. This paper introduces the output pulse height distribution of the GM counters, gives the measuring instruments and methods. The measuring results, some discussions, and useful conclusion are given as well

  2. The Counter Terrorist Classroom: Religion, Education, and Security

    Science.gov (United States)

    Gearon, Liam

    2013-01-01

    The article identifies international cases--from the United States, Europe, and the United Nations--of an emergent interface of religion, education, and security. This is manifest in the uses of religion in education to counter religious extremism, the notional "counter terrorist classroom." To avoid an over-association of extremism with…

  3. Counter-terrorism strategies in Indonesia, Algeria and Saudi Arabia

    NARCIS (Netherlands)

    Meijer, R.; Hasan, Noorhaidi; Hendriks, B.; Janssen, F.

    2012-01-01

    This report is the result of a year-long study, conducted from March 2010 to March 2011, of the counter-terrorist strategies of three countries: Indonesia, Algeria and Saudi Arabia. The aim of this study was to acquire insight into the counter-terrorist strategies of these countries, to analyse

  4. Analysis of Cherenkov counter efficiencies for E691

    International Nuclear Information System (INIS)

    Cremaldi, L.; Elliott, J.; Gibney, M.; Nauenberg, U.

    1985-01-01

    A program is outlined which simulates Cherenkov counters. The program can compute the effect of the magnetic field on the efficiencies of Cherenkov counters. It also tells what cone to mirror distance gives the highest collection efficiency and at which target position should the laser be placed to represent the direction of the actual Cherenkov light the mirror sees

  5. Presettable up-down CAMAC counter for 24 bit

    International Nuclear Information System (INIS)

    Kuhn, K.; Meyer, U.; Weidhase, F.

    1976-01-01

    A module containing a presettable binary up-down CAMAC counter for 24 bit is described. The use of dataway is discussed. As an example for application in nuclear physics, control of beam position by the up-down counter is illustrated

  6. Lessons from History for Counter- Terrorism Strategic Communications

    NARCIS (Netherlands)

    Ingram, H.J.; Reed, A.G.

    2016-01-01

    Drawing on the Counter-terrorism Strategic Communication (CTSC) Project’s research paper “A Brief History of Propaganda during Conflict“, this Policy Brief lays out the key policy-relevant lessons for developing effective counter-terrorism strategic communications. It presents a framework of

  7. Counter-Buffing: A Visual Criticism of Guerrilla Advertising

    Science.gov (United States)

    Lauzon, Robb Conrad; Cooke, Laquana

    2017-01-01

    This article addresses and explores hip-hop's reclamation of space using transit as a public bulletin. It is situated within counter-publics discourse and couched in the theoretical frameworks offered by visual rhetorical theory. This article also discusses hip-hop counter-publics through guerrilla advertising by former graffiti artists, SKI and…

  8. Counter diffusion of zinc and iron in alluvial soil

    International Nuclear Information System (INIS)

    Rattan, R.K.; Deb, D.L.

    1980-01-01

    Half cell technique showed that an increase in moisture tension and CaCO 3 content caused reduction in the counter diffusion coefficients of zinc and iron in an alluvial soil. Increases in bulk density, ambient temperature and concentration of synthetic chelating agents e.g. EDTA and DTPA increased the counter diffusion coefficients of both zinc and iron. (author)

  9. The IFIN-HH triple coincidence liquid scintillation counter

    CSIR Research Space (South Africa)

    Razdolescu, AC

    2006-10-01

    Full Text Available at IFIN-HH using a 3 H standard. The performances of the IFIN-HH TDCR counter was checked against the measurement results of the TDCR counters of CSIR NML (South Africa), RC (Poland) and LNHB (France). A set of ready-to-measure Ni-63 sources in liquid...

  10. Beam test of Cherenkov counter prototype for ZDF setup

    International Nuclear Information System (INIS)

    Kacharava, A.K.; Macharashvili, G.G.; Nioradze, M.S.; Komarov, V.I.; Sopov, V.S.; Chernyshev, V.P.

    1995-01-01

    We describe a Cherenkov counter of total internal reflection for particle separation in the momentum range where all types of particles radiate Cherenkov light. The Cherenkov counter prototype with the lucite radiator was tested on the secondary beam of the ITEP (Moscow) accelerator. Dependence of the photomultiplier pulse height on the particle entrance angle was clearly observed. 4 refs., 4 figs

  11. A proportional counter for efficient backscatter Moessbauer effect spectroscopy

    International Nuclear Information System (INIS)

    Pawlowski, Z.; Marzec, J.; Cudny, W.; Holnicka, J.; Walentek, J.

    1979-01-01

    The authors present a novel gas-tight proportional counter with flat beryllium windows for backscatter Moessbauer spectroscopy. The krypton-filled counter has a geometry that approaches 2π and a resolution of 12% fwhm for the 14.4 keV line of 57 Fe, and is easy to manufacture. (Auth.)

  12. Solar flare effect in equatorial magnetic field during morning counter electrojet

    International Nuclear Information System (INIS)

    Rangarajan, G.K.; Rastogi, R.G.

    1981-01-01

    Surface geomagnetic signatures of intense solar radio noise bursts are studied from the magnetograms of several equatorial and low latitude observatories. It is shown that for the even on 21 June 1980, the solar flare effect recorded was during a period of counter electrojet currents in the morning hours in the Indian region, and hence it reverses direction between Alibag and Trivandrum. The longitudinal extent of this event has been estimated to be less than three hours (45). (author)

  13. Over-the-counter medicine abuse ? a review of the literature

    OpenAIRE

    Cooper, Richard J.

    2011-01-01

    Background: The sale of over-the-counter (OTC) medicines from pharmacies can help individuals self-manage symptoms. However, some OTC medicines may be abused, with addiction and harms being increasingly recognised. This review describes the current knowledge and understanding of OTC medicine abuse. Approach: Comprehensive search of international empirical and review literature between 1990 and 2011. Findings: OTC medicine abuse was identified in many countries and although implicated products...

  14. Over-the-counter medicine abuse: a review of the\\ud literature

    OpenAIRE

    Cooper, R. J.

    2011-01-01

    Background: The sale of over-the-counter (OTC) medicines from pharmacies can help individuals self-manage symptoms. However, some OTC medicines may be abused, with addiction and harms being increasingly recognised. This review describes the current knowledge and understanding of\\ud OTC medicine abuse.\\ud \\ud Approach: Comprehensive search of international empirical and review literature between 1990 and 2011.\\ud \\ud Findings: OTC medicine abuse was identified in many countries and although im...

  15. Laboratory Evaluation of Light Obscuration Particle Counters used to Establish use Limits for Aviation Fuel

    Science.gov (United States)

    2015-12-01

    The Army currently utilizes two methods for measuring particulate contamination by gravimetric analysis: ASTM D2276 - Standard Test Method for...is checked every 30 days by gravimetric analysis (ASTM D2276). One of the problems with the gravimetric methods is the poor repeatability and...ASTM D2276 testing is an artifact of that method . The correlation of particle counter data to the theoretical gravimetric concentration, and cross

  16. Design of a novel quantum reversible ternary up-counter

    Science.gov (United States)

    Houshmand, Pouran; Haghparast, Majid

    2015-08-01

    Reversible logic has been recently considered as an interesting and important issue in designing combinational and sequential circuits. The combination of reversible logic and multi-valued logic can improve power dissipation, time and space utilization rate of designed circuits. Only few works have been reported about sequential reversible circuits and almost there are no paper exhibited about quantum ternary reversible counter. In this paper, first we designed 2-qutrit and 3-qutrit quantum reversible ternary up-counters using quantum ternary reversible T-flip-flop and quantum reversible ternary gates. Then we proposed generalized quantum reversible ternary n-qutrit up-counter. We also introduced a new approach for designing any type of n-qutrit ternary and reversible counter. According to the results, we can conclude that applying second approach quantum reversible ternary up-counter is better than the others.

  17. Prevention and Control Strategies to Counter Dengue Virus Infection.

    Science.gov (United States)

    Rather, Irfan A; Parray, Hilal A; Lone, Jameel B; Paek, Woon K; Lim, Jeongheui; Bajpai, Vivek K; Park, Yong-Ha

    2017-01-01

    Dengue is currently the highest and rapidly spreading vector-borne viral disease, which can lead to mortality in its severe form. The globally endemic dengue poses as a public health and economic challenge that has been attempted to suppress though application of various prevention and control techniques. Therefore, broad spectrum techniques, that are efficient, cost-effective, and environmentally sustainable, are proposed and practiced in dengue-endemic regions. The development of vaccines and immunotherapies have introduced a new dimension for effective dengue control and prevention. Thus, the present study focuses on the preventive and control strategies that are currently employed to counter dengue. While traditional control strategies bring temporary sustainability alone, implementation of novel biotechnological interventions, such as sterile insect technique, paratransgenesis, and production of genetically modified vectors, has improved the efficacy of the traditional strategies. Although a large-scale vector control strategy can be limited, innovative vaccine candidates have provided evidence for promising dengue prevention measures. The use of tetravalent dengue vaccine (CYD-TDV) has been the most effective so far in treating dengue infections. Nonetheless, challenges and limitation hinder the progress of developing integrated intervention methods and vaccines; while the improvement in the latest techniques and vaccine formulation continues, one can hope for a future without the threat of dengue virus.

  18. Prevention and Control Strategies to Counter Dengue Virus Infection

    Directory of Open Access Journals (Sweden)

    Irfan A. Rather

    2017-07-01

    Full Text Available Dengue is currently the highest and rapidly spreading vector-borne viral disease, which can lead to mortality in its severe form. The globally endemic dengue poses as a public health and economic challenge that has been attempted to suppress though application of various prevention and control techniques. Therefore, broad spectrum techniques, that are efficient, cost-effective, and environmentally sustainable, are proposed and practiced in dengue-endemic regions. The development of vaccines and immunotherapies have introduced a new dimension for effective dengue control and prevention. Thus, the present study focuses on the preventive and control strategies that are currently employed to counter dengue. While traditional control strategies bring temporary sustainability alone, implementation of novel biotechnological interventions, such as sterile insect technique, paratransgenesis, and production of genetically modified vectors, has improved the efficacy of the traditional strategies. Although a large-scale vector control strategy can be limited, innovative vaccine candidates have provided evidence for promising dengue prevention measures. The use of tetravalent dengue vaccine (CYD-TDV has been the most effective so far in treating dengue infections. Nonetheless, challenges and limitation hinder the progress of developing integrated intervention methods and vaccines; while the improvement in the latest techniques and vaccine formulation continues, one can hope for a future without the threat of dengue virus.

  19. Noise and LPI radar as part of counter-drone mitigation system measures

    Science.gov (United States)

    Zhang, Yan (Rockee); Huang, Yih-Ru; Thumann, Charles

    2017-05-01

    With the rapid proliferation of small unmanned aerial systems (UAS) in the national airspace, small operational drones are being sometimes considered as a security threat for critical infrastructures, such as sports stadiums, military facilities, and airports. There have been many civilian counter-drone solutions and products reported, including radar and electromagnetic counter measures. For the current electromagnetic solutions, they are usually limited to particular type of detection and counter-measure scheme, which is usually effective for the specific type of drones. Also, control and communication link technologies used in even RC drones nowadays are more sophisticated, making them more difficult to detect, decode and counter. Facing these challenges, our team proposes a "software-defined" solution based on noise and LPI radar. For the detection, wideband-noise radar has the resolution performance to discriminate possible micro-Doppler features of the drone versus biological scatterers. It also has the benefit of more adaptive to different types of drones, and covertly detecting for security application. For counter-measures, random noise can be combined with "random sweeping" jamming scheme, to achieve the optimal balance between peak power allowed and the effective jamming probabilities. Some theoretical analysis of the proposed solution is provided in this study, a design case study is developed, and initial laboratory experiments, as well as outdoor tests are conducted to validate the basic concepts and theories. The study demonstrates the basic feasibilities of the Drone Detection and Mitigation Radar (DDMR) concept, while there are still much work needs to be done for a complete and field-worthy technology development.

  20. Counter-terrorism threat prediction architecture

    Science.gov (United States)

    Lehman, Lynn A.; Krause, Lee S.

    2004-09-01

    This paper will evaluate the feasibility of constructing a system to support intelligence analysts engaged in counter-terrorism. It will discuss the use of emerging techniques to evaluate a large-scale threat data repository (or Infosphere) and comparing analyst developed models to identify and discover potential threat-related activity with a uncertainty metric used to evaluate the threat. This system will also employ the use of psychological (or intent) modeling to incorporate combatant (i.e. terrorist) beliefs and intent. The paper will explore the feasibility of constructing a hetero-hierarchical (a hierarchy of more than one kind or type characterized by loose connection/feedback among elements of the hierarchy) agent based framework or "family of agents" to support "evidence retrieval" defined as combing, or searching the threat data repository and returning information with an uncertainty metric. The counter-terrorism threat prediction architecture will be guided by a series of models, constructed to represent threat operational objectives, potential targets, or terrorist objectives. The approach would compare model representations against information retrieved by the agent family to isolate or identify patterns that match within reasonable measures of proximity. The central areas of discussion will be the construction of an agent framework to search the available threat related information repository, evaluation of results against models that will represent the cultural foundations, mindset, sociology and emotional drive of typical threat combatants (i.e. the mind and objectives of a terrorist), and the development of evaluation techniques to compare result sets with the models representing threat behavior and threat targets. The applicability of concepts surrounding Modeling Field Theory (MFT) will be discussed as the basis of this research into development of proximity measures between the models and result sets and to provide feedback in support of model

  1. Training options for countering nuclear smuggling

    International Nuclear Information System (INIS)

    Ball, D Y; Erickson, S A

    1999-01-01

    The burden of stopping a nuclear smuggling attempt at the border rests most heavily on the front-line customs inspector. He needs to know how to use the technological tools at his disposal, how to discern tell-tale anomalies in export documents and manifests, how to notice psychological signs of a smuggler's tension, and how to search anything that might hide nuclear material. This means that assistance in the counter-nuclear smuggling training of customs officers is one of the most critical areas of help that the United States can provide. This paper discusses the various modes of specialized training, both in the field and in courses, as well as the types of assistance that can be provided. Training for nuclear customs specialists, and supervisors and managers of nuclear smuggling detection systems is also important, and differs from front-line inspector training in several aspects. The limitations of training and technological tools such as expert centers that will overcome these limitations are also discussed. Training assistance planned by DOE/NN-43 to Russia within the Second Line of Defense program is discussed in the light of these options, and future possibilities for such training are projected

  2. Sexual revolution and counter-revolution.

    Science.gov (United States)

    Money, J

    1994-01-01

    Adolescents of today inherit the conflicting legacies of the sexual reformation of the 1960s and the counter-reformation of the 1980s/1990s. Sexual mores are influenced by a younger age of puberty than in earlier generations and by the availability of effective contraception and antibiotics to combat sexually transmitted diseases. In the era of acquired immune deficiency syndrome, however, absolutely safe sex cannot be guaranteed, only relative degrees of safety and risk. Masturbation may be one way of achieving safe sex. Advancing technology also allows greater equality of opportunity and economic emancipation for women, enabling men and women to share equally in the care of older infants and children, also influencing sexual roles. Sex education for adolescents is provided sporadically and inconsistently, being seen by opposing factions as either encouragement to early pregnancy or a means of preventing it. In particular, the images delivered by the mass media are blatantly contradictory, ranging from endorsement of teenage sexual expression to condemnation of abortion and teenage pregnancy. Cultural traditions have strong influences on the acceptability of early pregnancy and on family structure. Black American culture is based on the three-generational family as opposed to the white tradition of the nuclear, two-generational family. It is important to realize a social policy that will respect not only the sexual rights of young people, but also the sexual health of the community.

  3. The research on the failure regularity of GM counter tubes

    International Nuclear Information System (INIS)

    Li Jiyuan; Huai Guangli; Xie Bo; Zhang Hao

    2002-01-01

    The reliability of GM counter tubes should be described by useful time before failure-life and failure rate during life. A new method to study the failure regularity of GM counter tubes is advanced and adopted. The essential point of the method is that after the GM counter tubes of the instruments in use is tested, both the performance parameters and other information of the GM counter tubes and the instruments collected are recorded. Then database is created. Failure criterion is ascertained. The GM counter tubes are inspected to determine whether they are failure. Failure mode should be decided if the GM counter tubes failure. The GM counter tubes with the same useful year come together to make up a subsample. According to the relevant information, the number of the subsample is restored to the number of the sample that initially put into use. Then the number of failure sample is counted and at the same time the distribution of failure mode is got. The parameter m, γ, t 0 of Weibull distribution function are calculated with method of linear fit. Thus mean life, failure rate and other character values are obtained. Using this method, useful life and failure rate are determined. The conclusion is that the useful life is 18-20 years and the failure rate is 5 x 10 -6 and 4 x 10 -6 /h respectively during the course

  4. COUNTER-PUNISHMENT, COMMUNICATION AND COOPERATION AMONG PARTNERS

    Directory of Open Access Journals (Sweden)

    Giulia eAndrighetto

    2016-04-01

    Full Text Available We study how communication affects cooperation in an experimental public goods environment with punishment and counter-punishment opportunities. Participants interacted over thirty rounds in fixed groups with fixed identifiers that allowed them to trace other group members’ behavior over time. The two dimensions of communication we study are asking for a specific contribution level and having to express oneself when choosing to counter-punish. We conduct four experimental treatments, all involving a contribution stage, a punishment stage and a counter-punishment stage in each round. In the first treatment communication is not possible at any of the stages. The second treatment allows participants to ask for a contribution level at the punishment stage and in the third treatment participants are required to send a message if they decide to counter-punishment. The fourth combines the two communication channels of the second and third treatments. We find that the three treatments involving communication at any of the two relevant stages lead to significantly higher contributions than the baseline treatment. We find no difference between the three treatments with communication. We also relate our results to previous results from treatments without counter-punishment opportunities and do not find that the presence of counter-punishment leads to lower cooperation level. The overall pattern of results shows that given fixed identifiers the key factor is the presence of communication. Whenever communication is possible contributions and earnings are higher than when it is not, regardless of counter-punishment opportunities.

  5. A long-term analysis of Pt counter electrodes for Dye-sensitized Solar Cells exploiting a microfluidic housing system

    Energy Technology Data Exchange (ETDEWEB)

    Sacco, Adriano, E-mail: adriano.sacco@iit.it [Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Pugliese, Diego; Lamberti, Andrea [Applied Science and Technology Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Castellino, Micaela; Chiodoni, Angelica [Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Virga, Alessandro [Applied Science and Technology Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Bianco, Stefano [Center for Space Human Robotics @Polito, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Applied Science and Technology Department, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2015-07-01

    The study of the degradation process occurring in Dye-sensitized Solar Cells (DSCs) is still a hot topic, in view of the final industrialization and application of this class of devices. Currently the long-term analysis of DSCs is carried out on the entire devices, while the monitoring of cell components cannot be performed in situ directly on the materials, but only through indirect methods. In this paper we report on the analysis of two different kinds of Pt counter electrodes through direct measurements performed under real operating conditions, thanks to the use of a home-made microfluidic housing system, which allows the opening and the investigation of the cell components. The counter electrode samples were studied through X-Ray Photoelectron Spectroscopy, Field Emission Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, UV–visible Spectroscopy and Electrochemical Impedance Spectroscopy for a period longer than 1 year. The results showed that the performances of both classes of Pt counter electrodes remained stable for all the investigation period, despite some slight variation of the morphology. DSCs fabricated employing aged counter electrodes exhibited the same photovoltaic performance behavior of reference cells using fresh-produced counter electrodes, thus demonstrating that both class of materials do not undergo degradation during normal operating conditions. - Highlights: • The analysis of Pt counter electrodes for Dye-sensitized Solar Cells was carried out. • Two families of counter electrodes were studied for a period longer than 1 year. • The analyzed samples were investigated in real operating condition. • A small detachment of the Pt clusters in the thermal samples was observed. • The charge transfer properties remained unchanged for all the investigation period.

  6. Discussing Terrorism: A Pupil-Inspired Guide to UK Counter-Terrorism Policy Implementation in Religious Education Classrooms in England

    Science.gov (United States)

    Quartermaine, Angela

    2016-01-01

    My research into pupils' perceptions of terrorism and current UK counter-terrorism policy highlights the need for more detailed and accurate discussions about the implementation of the educational aims, in particular those laid out by the Prevent Strategy. Religious education (RE) in England is affected by these aims, specifically the challenging…

  7. Imagining Another Europe: Building a Pan-European Counter-Hegemonic Bloc Around an Anti-Austerity Master Frame

    NARCIS (Netherlands)

    Scholl, C.; Freyberg-Inan, A.

    Going beyond the local and national scopes of anti-austerity mobilizations, we contribute to this special issue by focusing on counter-hegemonic protest at the pan-European level. In the context of the current austerity regimes, this emerging and precarious social formation enacts resistance against

  8. 78 FR 68854 - Over-the-Counter Ophthalmic Drug Products-Emergency Use Eyewash Products; Rescheduling of Public...

    Science.gov (United States)

    2013-11-15

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-1038... information on the formulation, manufacturing, and labeling of currently marketed over- the-counter (OTC... hearing will be held on March 7, 2014, from 9 a.m. to 5 p.m. Submit electronic or written requests to make...

  9. Countering the ‘Natural’ Organizational Self on Social Media

    DEFF Research Database (Denmark)

    Johansen, Trine Susanne

    2017-01-01

    , challenge and contradict organizational self-narration in light of market place skepticism and cynicism. The study identifies three strategies of counter-narrativizing (authenticity, legitimacy and irony) based on juxtaposing pairs of opposites. Moreover, it suggests counter-narration to be a natural......Using narrative as a theoretical and methodological lens, this study explores digital processes of organizational identity construction in the intersection between organization and market.The purpose is to understand the ways in which online interactions produce counter-narratives that contrast...

  10. Multi-element proportional counter for radiation protection measurements

    International Nuclear Information System (INIS)

    Kliauga, P.; Rossi, H.H.; Johnson, G.

    1988-01-01

    This article discusses design modifications of a multi-element proportional counter. The original counter exhibited poor resolution, as measured by the width of the event-size spectrum for low-energy photons. It was also suspected that the field inside each volume was not sufficiently symmetric. Results of the modifications showed that a dramatic improvement in resolution could be obtained in the chamber with tissue-equivalent septa if their potentials were adjusted to obtain optimal resolution. The full width at half maximum then approached, although it did not equal, that of a standard spherical counter

  11. Hardware support for collecting performance counters directly to memory

    Science.gov (United States)

    Gara, Alan; Salapura, Valentina; Wisniewski, Robert W.

    2012-09-25

    Hardware support for collecting performance counters directly to memory, in one aspect, may include a plurality of performance counters operable to collect one or more counts of one or more selected activities. A first storage element may be operable to store an address of a memory location. A second storage element may be operable to store a value indicating whether the hardware should begin copying. A state machine may be operable to detect the value in the second storage element and trigger hardware copying of data in selected one or more of the plurality of performance counters to the memory location whose address is stored in the first storage element.

  12. Numerical modelling of tissue-equivalent proportional counters

    International Nuclear Information System (INIS)

    Segur, P.; Colautti, P.

    1995-01-01

    In this paper a survey is given of the various numerical techniques employed to study the transport of ionising particles inside a TEPC. The first part is devoted to the description of the general concept of particle transport calculations. Thereafter, the different methods available to study transport phenomena and energy deposition in the sensitive volume and in counter walls are described. Finally, the basic ionisation mechanisms which may occur in a counter are described, and the non-equilibrium phenomena which play an important role mainly for counters that are to be used in measurements at the nanodosemeter level are studied. (author)

  13. Compression under a mechanical counter pressure space suit glove

    Science.gov (United States)

    Waldie, James M A.; Tanaka, Kunihiko; Tourbier, Dietmar; Webb, Paul; Jarvis, Christine W.; Hargens, Alan R.

    2002-01-01

    Background: Current gas-pressurized space suits are bulky stiff shells severely limiting astronaut function and capability. A mechanical counter pressure (MCP) space suit in the form of a tight elastic garment could dramatically improve extravehicular activity (EVA) dexterity, but also be advantageous in safety, cost, mass and volume. The purpose of this study was to verify that a prototype MCP glove exerts the design compression of 200 mmHg, a pressure similar to the current NASA EVA suit. Methods: Seven male subjects donned a pressure measurement array and MCP glove on the right hand, which was placed into a partial vacuum chamber. Average compression was recorded on the palm, the bottom of the middle finger, the top of the middle finger and the dorsum of the hand at pressures of 760 (ambient), 660 and 580 mmHg. The vacuum chamber was used to simulate the pressure difference between the low breathing pressure of the current NASA space suits (approximately 200 mmHg) and an unprotected hand in space. Results: At ambient conditions, the MCP glove compressed the dorsum of the hand at 203.5 +/- 22.7 mmHg, the bottom of the middle finger at 179.4 +/- 16.0 mmHg, and the top of the middle finger at 183.8 +/- 22.6 mmHg. The palm compression was significantly lower (59.6 +/- 18.8 mmHg, pglove compression with the chamber pressure reductions. Conclusions: The MCP glove compressed the dorsum of the hand and middle finger at the design pressure.

  14. Electrical properties of graphene film for counter electrode in dye sensitized solar cells

    Science.gov (United States)

    Khalifa, Ali; Shafie, S.; Hasan, W. Z. W.; Lim, H. N.; Rusop, M.; Samaila, Buda

    2018-05-01

    A graphene counter electrode for dye-sensitized solar cell was prepared simply by drop casting method on a conducting FTO glass at room temperature. Raman spectroscopy was used to study the defection in the graphene films. The sheet resistance was also measured and recoded minimum value of 7.04 Ω/□ at 22.19µm thickness. The casted films show good adhesion to substrates with low defects. A DSSC based on graphene counter electrode demonstrates reasonable conversion efficiency of 2.78% with short circuit current of 7.60mA, open circuit voltage of 0.69V and fill factor of 0.52. The high conductivity and low defects render the prepared graphene dispersion for DSSCs' CE application.

  15. The Global Benchmarking as a Method of Countering the Intellectual Migration in Ukraine

    Directory of Open Access Journals (Sweden)

    Striy Lуbov A.

    2017-05-01

    Full Text Available The publication is aimed at studying the global benchmarking as a method of countering the intellectual migration in Ukraine. The article explores the intellectual process of migration in Ukraine; the current status of the country in the light of crisis and all the problems that arose has been analyzed; statistical data on the migration process are provided, the method of countering it has been determined; types of benchmarking have been considered; the benchmarking method as a way of achieving objective has been analyzed; the benefits to be derived from this method have been determined, as well as «bottlenecks» in the State process of regulating migratory flows, not only to call attention to, but also take corrective actions.

  16. Counter and Complicit Masculine Discourse Among Men's Shed Members.

    Science.gov (United States)

    Mackenzie, Corey S; Roger, Kerstin; Robertson, Steve; Oliffe, John L; Nurmi, Mary Anne; Urquhart, James

    2017-07-01

    Men's Sheds is a growing international movement aimed at providing men with places and activities that facilitate social connectedness. Despite Men's Sheds' focus on males, little attention has been paid to masculinities within the specific context of these settings. The current study used a gender relations framework to explore the ways in which attendees discussed Men's Sheds, with particular attention to discussions that were complicit and counter to traditional, hegemonic views of masculinity, and diverse positions in between these binaries. The data consisted of transcripts and field notes from four focus groups comprising mostly older, White, retired male members of a Canadian shed ( N = 22). The analysis revealed three overall themes: (1) focus on work, (2) independence, and (3) need for male-focused spaces. These themes and associated subthemes suggest that shed members ascribe to dominant masculine values and ideals, but also support more fluid and flexible views of masculinity. Implications are discussed for how working with an array of masculinities within the Men's Sheds movement will be helpful with respect to their future growth in Canada and internationally.

  17. Digital signal processing for He3 proportional counter

    International Nuclear Information System (INIS)

    Zeynalov, Sh.S.; Ahmadov, Q.S.

    2010-01-01

    Full text : Data acquisition systems for nuclear spectroscopy have traditionally been based on systems with analog shaping amplifiers followed by analog-to-digital converters. Recently, however, new systems based on digital signal processing make possible to replace the analog shaping and timing circuitry the numerical algorithms to derive properties of the pulse such as its amplitude. DSP is a fully numerical analysis of the detector pulse signals and this technique demonstrates significant advantages over analog systems in some circumstances. From a mathematical point of view, one can consider the signal evolution from the detector to the ADC as a sequence of transformations that can be described by precisely defined mathematical expressions. Digital signal processing with ADCs has the possibility to utilize further information on the signal pulses from radiation detectors. In the experiment each step of the signal generation in the 3He filled proportional counter was described using digital signal processing techniques (DSP). The electronic system has consisted of a detector, a preamplifier and a digital oscilloscope. The pulses from the detector were digitized using a digital storage oscilloscope. This oscilloscope allowed signal digitization with accuracy of 8 bit (256 levels) and with frequency of up to 5 * 10 8 samples/s. As a neutron source was used Cf-252. To obtain detector output current pulse I(t) created by the motions of the ions/electrons pairs was written an algorithm which can easily be programmed using modern computer programming languages.

  18. Counter flow cooling drier with integrated heat recovery

    Science.gov (United States)

    Shivvers, Steve D [Prole, IA

    2009-08-18

    A drier apparatus for removing water or other liquids from various materials includes a mixer, drying chamber, separator and regenerator and a method for use of the apparatus. The material to be dried is mixed with a heated media to form a mixture which then passes through the chamber. While passing through the chamber, a comparatively cool fluid is passed counter current through the mixture so that the mixture becomes cooler and drier and the fluid becomes hotter and more saturated with moisture. The mixture is then separated into drier material and media. The media is transferred to the regenerator and heated therein by the hot fluid from the chamber and supplemental heat is supplied to bring the media to a preselected temperature for mixing with the incoming material to be dried. In a closed loop embodiment of the apparatus, the fluid is also recycled from the regenerator to the chamber and a chiller is utilized to reduce the temperature of the fluid to a preselected temperature and dew point temperature.

  19. Characterization of counter-rotating streamwise vortices in flat rectangular channel with one-sided wavy wall

    KAUST Repository

    Bouremel, Yann; Mitsudharmadi, Hatsari; Budiman, Alexander C.; Winoto, Sonny H.

    2016-01-01

    Particle Image Velocimetry (PIV) has been used to characterize the evolution of counter-rotating streamwise vortices in a rectangular channel with one sided wavy surface. The vortices were created by a uniform set of saw-tooth carved over the leading edge of a flat plate at the entrance of a flat rectangular channel with one-sided wavy wall. PIV measurements were taken over the spanwise and streamwise planes at different locations and at Reynolds number of 2500. Two other Reynolds numbers of 2885 and 3333 have also been considered for quantification purpose. Pairs of counter-rotating streamwise vortices have been shown experimentally to be centred along the spanwise direction at the saw-tooth valley where the vorticity ωz=0ωz=0. It has also been found that the vorticity ωzωz of the pairs of counter-rotating vortices decreases along the streamwise direction, and increases with the Reynolds number. Moreover, different quantifications of such counter-rotating vortices have been discussed such as their size, boundary layer, velocity profile and vorticity. The current study shows that the mixing due to the wall shear stress of counter-rotating streamwise vortices as well as their averaged viscous dissipation rate of kinetic energy decrease over flat and adverse pressure gradient surfaces while increasing over favourable pressure gradient surfaces. Finally, it was also demonstrated that the main direction of stretching is orientated at around 45° with the main flow direction.

  20. Characterization of counter-rotating streamwise vortices in flat rectangular channel with one-sided wavy wall

    KAUST Repository

    Bouremel, Yann

    2016-11-01

    Particle Image Velocimetry (PIV) has been used to characterize the evolution of counter-rotating streamwise vortices in a rectangular channel with one sided wavy surface. The vortices were created by a uniform set of saw-tooth carved over the leading edge of a flat plate at the entrance of a flat rectangular channel with one-sided wavy wall. PIV measurements were taken over the spanwise and streamwise planes at different locations and at Reynolds number of 2500. Two other Reynolds numbers of 2885 and 3333 have also been considered for quantification purpose. Pairs of counter-rotating streamwise vortices have been shown experimentally to be centred along the spanwise direction at the saw-tooth valley where the vorticity ωz=0ωz=0. It has also been found that the vorticity ωzωz of the pairs of counter-rotating vortices decreases along the streamwise direction, and increases with the Reynolds number. Moreover, different quantifications of such counter-rotating vortices have been discussed such as their size, boundary layer, velocity profile and vorticity. The current study shows that the mixing due to the wall shear stress of counter-rotating streamwise vortices as well as their averaged viscous dissipation rate of kinetic energy decrease over flat and adverse pressure gradient surfaces while increasing over favourable pressure gradient surfaces. Finally, it was also demonstrated that the main direction of stretching is orientated at around 45° with the main flow direction.

  1. 3He neutral current detectors at SNO

    International Nuclear Information System (INIS)

    Elliott, S.R.; Browne, M.C.; Doe, P.J.

    1998-01-01

    The flux of solar neutrinos measured via charged and neutral current interactions can provide a model independent test of neutrino oscillations. Since the Sudbury Neutrino Observatory uses heavy water as a target, it has a large sensitivity to both interactions. A technique for observing the neutral current breakup of the deuteron using 3 He proportional counters is described

  2. Political struggles in disability’s visibilization: direct actions, counter-conducts and resistance

    Directory of Open Access Journals (Sweden)

    Alejandro Martín Contino

    2013-12-01

    Full Text Available Since the examination of the current situation of persons under disability, the hypothesis of conceiving disability as a device is carried out, according to the French philosopher Michel Foucault. Thus, the negative aspects experienced by subjects in situation of disability, not implying malfunction of public policy, would be logical and expected effects, the typical function of a disability device that works according to the guidelines of the Medical-Individual model. This article intends to present the tactics of counter-conduct as ways of subjectivation that resist current governmentality, becoming the visibilization of such actions, a key aspect of any strategy of political transformation.

  3. Counter-Chemical, Biological, Radiological, and Nuclear Operations

    National Research Council Canada - National Science Library

    2007-01-01

    ..., with little or no warning. Success in defending our nation, our military forces, and partners and allies depends on how effectively we apply air, space, and cyberspace power to counter this threat...

  4. Constant sensitivity circuit for solid state nuclear radiation counters

    International Nuclear Information System (INIS)

    Kronenberg, S.; Erkkila, B.

    1985-01-01

    The utilization of solid state counters in tactical radiological instruments for measuring intensities and doses of fallout gamma rays offers advantages over Geiger-Mueller (GM) counters such as a much wider dynamic range and low operating voltages. Their very small size is suitable for use in miniaturized equipment. However, these devices have a serious problem if used in a mixed, fast neutron/gamma environment such as is encountered e.g. in a battlefield where tactical nuclear weapons are used and neutrons, prompt, initial gammas and fallout gammas are killing factors of comparable importance. Exposure to fast neutrons reduces seriously their sensitivity. This makes the solid state counters at this time unacceptable for use in Army tactical surveillance equipment and in other applications where according to requirements the performance must not be impaired by exposure to fast neutrons. It seems to be possible to reduce to some extent this neutron generated damage by improving the crystal counters

  5. Expanded and combined uncertainty in measurements by GM counters

    International Nuclear Information System (INIS)

    Stankovic, K.; Arandjic, D.; Lazarevic, Dj.; Osmokrovic, P.

    2007-01-01

    This paper deals with possible ways of obtaining expanded and combined uncertainty in measurements for four types of GM counters with a same counter's tube, in cases when the contributors of these uncertainties are cosmic background radiation and induced overvoltage phenomena. Nowadays, as a consequence of electromagnetic radiation, the latter phenomenon is especially marked in urban environments. Based on experimental results obtained, it has been established that the uncertainties of an influenced random variable 'number of pulses from background radiation' and 'number of pulses induced by overvoltage' depend on the technological solution of the counter's reading system and contribute in different ways to the expanded and combined uncertainty in measurements of the applied types of GM counters. (author)

  6. Discrimination capability of avalanche counters detecting different ionizing particles

    International Nuclear Information System (INIS)

    Prete, G.; Viesti, G.; Padua Univ.

    1985-01-01

    The discrimination capability of avalanche counters to detect different ionizing particles has been studied using a 252 Cf source. Pulse height, pulse-height resolution and timing properties have been measured as a function of the reduced applied voltage for parallel-plate and parallel-grid avalanche counters. At the highest applied voltages, space charge effects shift the pulse-height signal of the avalanche counter away from being linearly proportional to the stopping power of the detected particles and cause the pulse-height resolution to deteriorate. To optimize the avalanche counter capability, without loss of time resolution, it appears better to operate the detector at voltages well below the breakdown threshold. Measurements with 32 S ions are also reported. (orig.)

  7. Calibration and Monte Carlo modelling of neutron long counters

    CERN Document Server

    Tagziria, H

    2000-01-01

    The Monte Carlo technique has become a very powerful tool in radiation transport as full advantage is taken of enhanced cross-section data, more powerful computers and statistical techniques, together with better characterisation of neutron and photon source spectra. At the National Physical Laboratory, calculations using the Monte Carlo radiation transport code MCNP-4B have been combined with accurate measurements to characterise two long counters routinely used to standardise monoenergetic neutron fields. New and more accurate response function curves have been produced for both long counters. A novel approach using Monte Carlo methods has been developed, validated and used to model the response function of the counters and determine more accurately their effective centres, which have always been difficult to establish experimentally. Calculations and measurements agree well, especially for the De Pangher long counter for which details of the design and constructional material are well known. The sensitivit...

  8. Retrofit designs for small bench-type blood cell counters.

    Science.gov (United States)

    Ferris, C D

    1991-01-01

    This paper describes several retrofit designs to correct operational problems associated with small bench-type blood cell counters. Replacement electronic circuits as well as modifications to the vacuum systems are discussed.

  9. The scintillation counter system at the SAPHIR detector

    International Nuclear Information System (INIS)

    Bour, D.

    1989-10-01

    The scintillation-counters system of the SAPHIR-detector at the stretcher accelerator ELSA in Bonn consists of 64 counters. It supplies a fast hadronic trigger and is utilizised for the particle identification by time of flight measurements. Prototypes of the counters (340x21.25 x 6.0 cm 3 ) had been tested. The contribution to the resolution of the time of flight measurement was measured to σ=125 ps, the effective light velocity to 17.5 ns/cm and the attenuation length of 7.8 m. A pion kaon separation is possible up to a momentum of 1 GeV/c with time of flight measurement. With the first photon-beam at SAPHIR the counters were tested, first triggers were obtained and evaluated. (orig.) [de

  10. New proportional counter assembly in Gliwice 14C laboratory

    International Nuclear Information System (INIS)

    Moscicki, W.; Zastawny, A.

    1977-01-01

    The design and parameters are described of a proportional counter for low level counting. The cathode tube 80 mm in diameter and 30 cm in length is made of pure copper. The anode is a tungsten wire 0.05 mm in diameter. The cathode tube is surrounded by a cylindrical ring container with mercury. The total volume of the counter is 1.5 l and it is filled with carbon dioxide. At a pressure of 1 at of CO 2 the counter background is 4.20+-0.05 cpm and contemporary 14 C net effect 10.22+-0.10 cpm; at a pressure of 2 at of CO 2 the background is 4.40+-0.05 cpm and the contemporary 14 C net effect 20.53+-10 cpm. The efficiency of the proportional counter is 88% in both cases. (J.B.)

  11. PERUMUSAN STRATEGI PEMASARAN FRY COUNTER DENGAN PENDEKATAN MODEL AIDA

    OpenAIRE

    Andi Oktoriyana; Ujang Sumarwan; Hartoyo Hartoyo

    2014-01-01

    This research examined factors which are mentioned in various literatures that have influence on AIDA models to buy fry counter which are attention, interest, and desire. The model also influenced by perceived attributes, personal characteristics, and external factors. Furthermore, the analysis result become a basic for formulating the marketing strategy of fry counter as an innovative product. Analysis was carried out using Structural Equation Modeling. The data for this study were collected...

  12. Test of long scintillating counter prototypes for CDF-II

    International Nuclear Information System (INIS)

    Budagov, Yu.; Chirikov-Zorin, I.; Pukhov, O.; Incagli, M.; Leone, S.; Menzione, A.; Pauletta, G.; Tokar, S.

    2000-01-01

    New type long (up to 3 m) scintillating counter prototypes, developed for CDF-II, have been tested. The shift-spectrum fiber ribbons were used for light collection, and modern ultra compact photomultipliers R5600 were used for light detection. The efficiency for m.i.p. was excellent for all prototypes. The light yield from the far end of the counters was found to be more than 20 photoelectrons

  13. High-level neutron coincidence counter (HLNCC): users' manual

    International Nuclear Information System (INIS)

    Krick, M.S.; Menlove, H.O.

    1979-06-01

    This manual describes the portable High-Level Neutron Coincidence Counter (HLNCC) developed at the Los Alamos Scientific Laboratory (LASL) for the assay of plutonium, particularly by inspectors of the International Atomic Energy Agency (IAEA). The counter is designed for the measurement of the effective 240 Pu mass in plutonium samples which may have a high plutonium content. The following topics are discussed: principle of operation, description of the system, operating procedures, and applications

  14. A Bayesian statistical method for particle identification in shower counters

    International Nuclear Information System (INIS)

    Takashimizu, N.; Kimura, A.; Shibata, A.; Sasaki, T.

    2004-01-01

    We report an attempt on identifying particles using a Bayesian statistical method. We have developed the mathematical model and software for this purpose. We tried to identify electrons and charged pions in shower counters using this method. We designed an ideal shower counter and studied the efficiency of identification using Monte Carlo simulation based on Geant4. Without having any other information, e.g. charges of particles which are given by tracking detectors, we have achieved 95% identifications of both particles

  15. Design and Implementation of MOD-6 Synchronous Counter using VHDL

    Directory of Open Access Journals (Sweden)

    P. Y. Dibal

    2013-08-01

    Full Text Available This paper deals with the design of a MOD-6 synchronous counter using VHDL (VHSIC Hardware Description Language. The VHSIC stands for Very High Speed Integrated Circuit. Using this approach, the behaviour of the counter is the most important aspect of the design. In the first section, the paper introduced counters in general, and their areas of specialization, like frequency synthesizers. The synchronous counter was then introduced, stating the behaviour of the flip-flops that make the counter. The modulus of a counter was defined. In the second section, the Xilinx ISE (Integrated Simulation Environment and the ISIM (Integrated Simulator were presented and briefly described with their respective snapshots. The structure of a typical VHDL code was presented, which included LIBRARY, ENTITY, and ARCHITECTURE. Each of these structures was then briefly described. The main work in this paper was then presented. The count sequence steps were stated as . VHDL was used to model the counter to count through six steps, outputting count values according to desired steps. The hardware implementation of the design was presented, where the implementation process was described, with a supporting diagram, followed by the floor-planning technique, in which the PORTS described in the VHDL design were assigned to the physical pins of the XC3S1000 FPGA (Field Programmable Gate Array chip. The final steps of the hardware implementation process were then presented. These include bitstream generation and download to target device. The third section of the paper presented the results obtained. Simulation/timing results of the design were presented, showing the output of the counter at each state with respect to the clock signal. The result of the synthesis of the design was presented, which showed the FPGA area with the exact location of the pins on the FPGA chip. Finally, the fourth section presented the conclusion arrived at, in respect of the design that was carried

  16. A comprehensive test specification for pulse fission counters

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, D L [Control and Instrumentation Division, Atomic Energy Establishment, Winfrith, Dorchester, Dorset (United Kingdom)

    1962-02-15

    The following test specification is based on the memorandum AERE - M 728 which it now replaces It contains a standard acceptance test procedure for the many U.K.A.E.A, designed pulse fission counters now commercially available. This test specification may be used for any pulse fission counter provided a specification sheet as shown in Appendix 3 is supplied to the contractor quoting this report and including specified values for the measured quantities. (author)

  17. Recoil-proton fast-neutron counter telescope

    Energy Technology Data Exchange (ETDEWEB)

    Pavan, P.; Toniolo, D.; Zago, G.; Zannoni, R. (Padua Univ. (Italy). Ist. di Fisica); Galeazzi, G.; Bressanini, G.

    1981-12-01

    A recoil-proton neutron counter telescope is described composed of a solid-state silicon transmission detector and a NE 102 A plastic scintillator, measuring the energy loss, the energy of the recoil protons and the time of flight between the two detectors. The counter exposed to monoenergetic neutron beams of energy from 6 to 20 MeV presents a low background and a moderate energy resolution. Its absolute efficiency is calculated up to 50 MeV.

  18. Recoil-proton fast-neutron-counter telescope

    Energy Technology Data Exchange (ETDEWEB)

    Galeazzi, G.; Pavan, P.; Toniolo, D.; Zago, G.; Zannoni, R.; Bressanini, G.

    1981-01-01

    A proton-recoil neutron counter telescope is described composed of a solid state silicon transmission detector and a NE 102 A plastic scintillator, measuring the energy loss, the energy of the recoil protons and the time-of-flight between the two detectors. The counter exposed to monoenergetic neutron beams of energy from 6 to 20 MeV, presents a low background and a moderate energy resolution. Its absolute efficiency is calculated up to 50 MeV.

  19. A recoil-proton fast-neutron counter telescope

    International Nuclear Information System (INIS)

    Pavan, P.; Toniolo, D.; Zago, G.; Zannoni, R.; Galeazzi, G.; Bressanini, G.

    1981-01-01

    A recoil-proton neutron counter telescope is described composed of a solid-state silicon transmission detector and a NE 102 A plastic scintillator, measuring the energy loss, the energy of the recoil protons and the time of flight between the two detectors. The counter exposed to monoenergetic neutron beams of energy from 6 to 20 MeV presents a low background and a moderate energy resolution. Its absolute efficiency is calculated up to 50 MeV. (author)

  20. Using DMA for copying performance counter data to memory

    Science.gov (United States)

    Gara, Alan; Salapura, Valentina; Wisniewski, Robert W

    2013-12-31

    A device for copying performance counter data includes hardware path that connects a direct memory access (DMA) unit to a plurality of hardware performance counters and a memory device. Software prepares an injection packet for the DMA unit to perform copying, while the software can perform other tasks. In one aspect, the software that prepares the injection packet runs on a processing core other than the core that gathers the hardware performance data.

  1. Case study for co and counter swirling domestic burners

    Directory of Open Access Journals (Sweden)

    Ashraf Kotb

    2018-03-01

    Full Text Available In this case study, the influence of equivalence ratio for co and counter-swirl domestic burners compared with non-swirl design on the thermal efficiency as well as CO emissions has been studied using liquefied petroleum gas (LPG. Also, the flame stability, and pot height, which is defined as the burner-to-pot distance (H, of the co and counter domestic burners were compared. The analysis of the results showed that, for both swirl burners co and counter one the thermal efficiency under all operation conditions tested is higher than the non-swirled burner (base burner. For example, the thermal efficiency increased by 8.8%, and 5.8% than base burner for co and counter swirl, respectively at Reynolds number equal 2000 and equivalence ratio 1. The co and counter swirl burners show lower CO emission than the base burner. The co swirl burner has wider operation range than counter swirl. With the increase of pot height, the thermal efficiency of all burners decreases because the flame and combustion gases are cooled due to mixing with ambient air. As a result, the heat transfer is decreased due to atmospheric loss, which decrease the thermal efficiency.

  2. Advertising health: the case for counter-ads.

    Science.gov (United States)

    Dorfman, L; Wallack, L

    1993-01-01

    Public service advertisements have been used by many in hopes of "selling" good health behaviors. But selling good behavior--even if it could be done more effectively--is not the best goal for using mass media to prevent health problems. Personal behavior is only part of what determines health status. Social conditions and the physical environment are important determinants of health that are usually ignored by health promotion advertising. Public service advertising may be doing more harm than good if it is diverting attention from more effective socially based health promotion strategies. Counter-ads are one communications strategy that could be used to promote a broader responsibility for rectifying health problems. In the tradition of advocacy advertising directly promoting policy rather than products, counter-ads promote views consistent with a public health perspective. Counter-ads set the agenda for health issues, conferring status on policy-oriented strategies for addressing health problems. The primary purpose of counter-ads is to challenge the dominant view that public health problems reflect personal health habits. They are controversial because they place health issues in a social and political context. Advertising strategies for health promotion range over a spectrum from individually oriented public service advertising to socially oriented counter-advertising. The recent anti-tobacco campaign from the California Department of Health Services represents advertisements across the spectrum. Counter-ads that focus on a politically controversial definition for health problems are an appropriate and necessary alternative to public service advertising. PMID:8265756

  3. Over-the-counter codeine use in Iceland

    DEFF Research Database (Denmark)

    Almarsdóttir, A B; Grimsson, A

    2000-01-01

    BACKGROUND: The objective of this study was to test the assumption that liberalizing community pharmacy ownership in Iceland would lead to increased irrational use of over-the-counter pain relievers containing codeine. METHODS: Based on this assumption we built and tested a model using an interru......BACKGROUND: The objective of this study was to test the assumption that liberalizing community pharmacy ownership in Iceland would lead to increased irrational use of over-the-counter pain relievers containing codeine. METHODS: Based on this assumption we built and tested a model using...... an interrupted time series design that contrasts the monthly sales data for over-the-counter pain relievers containing codeine before and after the legislation took effect. RESULTS: The total use of over-the-counter pain relievers containing codeine as well as those containing paracetamol and codeine has risen...... leads to irrational use of over-the-counter medicines is not substantiated in the case of over-the-counter pain relievers containing codeine....

  4. Position sensitive proportional counters as focal plane detectors

    International Nuclear Information System (INIS)

    Ford, J.L.C. Jr.

    1979-01-01

    The rise time and charge division techniques for position decoding with RC-line proportional counters are reviewed. The advantages that these detectors offer as focal plane counters for nuclear spectroscopy performed with magnetic spectrographs are discussed. The theory of operation of proportional counters as position sensing devices is summarized, as well as practical aspects affecting their application. Factors limiting the position and energy resolutions obtainable with a focal plane proportional counter are evaluated and measured position and energy loss values are presented for comparison. Detector systems capable of the multiparameter measurements required for particle identification, background suppression and ray-tracing are described in order to illustrate the wide applicability of proportional counters within complex focal plane systems. Examples of the use of these counters other than with magnetic spectrographs are given in order to demonstrate their usefulness in not only nuclear physics but also in fields such as solid state physics, biology, and medicine. The influence of the new focal plane detector systems on future magnetic spectrograph designs is discussed. (Auth.)

  5. Ideal response function of a 3He proportional counter to thermal neutrons determined by different length counters

    International Nuclear Information System (INIS)

    Takeda, Naoto; Kudo, Katsuhisa; Kobayashi, Katsuhei; Yoshimoto, Takaaki

    2000-01-01

    The relative gas multiplication along the cylindrical axis of three 3 He proportional counters with different length were measured by using a thermal neutron beam at the Kyoto University Reactor and an ideal response function by taking into account the difference of pulse height spectra were measured by different length counters. The three 3 He proportional counters (model type of P4-0806, P4-0806 and P4-0808 manufactured by Reuter-Stokes) prepared for relative gas multiplication measurements had identical structure having cylindrical outer shells of 304 stainless steel except for different sensitive lengths of 10 cm, 15 cm and 20 cm, respectively. All counters were filled with 400 kPa of 3 He gas and 200 kPa of Ar gas. The pulse height distributions were measured by moving the counter in the direction of it's cylindrical axis perpendicular to the thermal neutron beam. The measured pulse heights corresponding to the full energy peaks at various entrance points were normalized to that of the whole counter irradiation. The results as a function of the distance from the bottom edge of the stainless steel cylinder are shown. The total transition region of gas gain corresponded to about 23 %, 15 % and 10 % of each nominal sensitive region corresponding to shot, middle and long counters. The ideal pulse height spectrum (dots) obtained by using proportional counters of 10 cm and 20 cm in nominal sensitive length to thermal neutron beam is shown in the paper in comparison to simulated one which was calculated assuming the constant gain within the sensitive region and zero gas gain outside the sensitive regions. The simulation realized the ideal response function fairly well. (S.Y.)

  6. An 'intelligent' approach to radioimmunoassay sample counting employing a microprocessor-controlled sample counter

    International Nuclear Information System (INIS)

    Ekins, R.P.; Sufi, S.; Malan, P.G.

    1978-01-01

    The enormous impact on medical science in the last two decades of microanalytical techniques employing radioisotopic labels has, in turn, generated a large demand for automatic radioisotopic sample counters. Such instruments frequently comprise the most important item of capital equipment required in the use of radioimmunoassay and related techniques and often form a principle bottleneck in the flow of samples through a busy laboratory. It is therefore imperative that such instruments should be used 'intelligently' and in an optimal fashion to avoid both the very large capital expenditure involved in the unnecessary proliferation of instruments and the time delays arising from their sub-optimal use. Most of the current generation of radioactive sample counters nevertheless rely on primitive control mechanisms based on a simplistic statistical theory of radioactive sample counting which preclude their efficient and rational use. The fundamental principle upon which this approach is based is that it is useless to continue counting a radioactive sample for a time longer than that required to yield a significant increase in precision of the measurement. Thus, since substantial experimental errors occur during sample preparation, these errors should be assessed and must be related to the counting errors for that sample. The objective of the paper is to demonstrate that the combination of a realistic statistical assessment of radioactive sample measurement, together with the more sophisticated control mechanisms that modern microprocessor technology make possible, may often enable savings in counter usage of the order of 5- to 10-fold to be made. (author)

  7. A novel high-performance counter electrode for dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Wang Guiqiang; Lin Ruifeng; Lin Yuan; Li Xueping; Zhou Xiaowen; Xiao Xurui

    2005-01-01

    A novel Pt counter electrode for dye-sensitized solar cells (DSC) was prepared by thermal decomposition of H 2 PtCl 6 on NiP-plated glass substrate. The charge-transfer kinetic properties of the platinized NiP-plated glass electrode (Pt/NiP electrode) for triiodide reduction were studied by electrochemical impedance spectroscopy. Pt/NiP electrode has the advantage over the platinized FTO conducting glass electrode (Pt/FTO electrode) in increasing the light reflectance and reducing the sheet resistance leading to improve the light harvest efficiency and the fill factor of the dye-sensitized solar cells effectively. The photon-to-current efficiency and the overall conversion efficiency of DSC using Pt/NiP counter electrode is increased by 20% and 33%, respectively, compared to that of using Pt/FTO counter electrode. Examination of the anodic dissolution and the long-term test on the variation of charge-transfer resistance indicates the good stability of the Pt/NiP electrode in the electrolyte containing iodide/triiodide

  8. 'Intelligent' approach to radioimmunoassay sample counting employing a microprocessor controlled sample counter

    International Nuclear Information System (INIS)

    Ekins, R.P.; Sufi, S.; Malan, P.G.

    1977-01-01

    The enormous impact on medical science in the last two decades of microanalytical techniques employing radioisotopic labels has, in turn, generated a large demand for automatic radioisotopic sample counters. Such instruments frequently comprise the most important item of capital equipment required in the use of radioimmunoassay and related techniques and often form a principle bottleneck in the flow of samples through a busy laboratory. It is therefore particularly imperitive that such instruments should be used 'intelligently' and in an optimal fashion to avoid both the very large capital expenditure involved in the unnecessary proliferation of instruments and the time delays arising from their sub-optimal use. The majority of the current generation of radioactive sample counters nevertheless rely on primitive control mechanisms based on a simplistic statistical theory of radioactive sample counting which preclude their efficient and rational use. The fundamental principle upon which this approach is based is that it is useless to continue counting a radioactive sample for a time longer than that required to yield a significant increase in precision of the measurement. Thus, since substantial experimental errors occur during sample preparation, these errors should be assessed and must be releted to the counting errors for that sample. It is the objective of this presentation to demonstrate that the combination of a realistic statistical assessment of radioactive sample measurement, together with the more sophisticated control mechanisms that modern microprocessor technology make possible, may often enable savings in counter usage of the order of 5-10 fold to be made. (orig.) [de

  9. The counter-terrorist campus: Securitisation theory and university securitisation – Three Models

    Directory of Open Access Journals (Sweden)

    Liam Gearon

    2017-02-01

    Full Text Available With intensified threats to global security from international terrorism, universities have become a focus for security concerns and marked as locus of special interest for the monitoring of extremism and counter-terrorism efforts by intelligence agencies worldwide. Drawing on initiatives in the United Kingdom and United States, I re-frame three – covert, overt and covert–overt – intersections of education, security and intelligence studies as a theoretical milieu by which to understand such counter-terrorism efforts. Against the backdrop of new legislative guidance for universities in an era of global terrorism and counter-terrorism efforts by security and intelligence agencies and their Governments, and through a review of Open-Source security/intelligence concerning universities in the United Kingdom and the United States, I show how this interstitial (covert, overt and covert– overt complexity can be further understood by the overarching relationship between securitisation theory and university securitisation. An emergent securitised concept of university life is important because de facto it will potentially effect radical change upon the nature and purposes of the university itself. A current-day situation replete with anxiety and uncertainty, the article frames not only a sharply contested and still unfolding political agenda for universities but a challenge to the very nature and purposes of the university in the face of a potentially existential threat. Terrorism and counterterrorism, as manifest today, may well thus be altering the aims and purposes of the university in ways we as yet do not fully know or understand. This article advances that knowledge and understanding through a theoretical conceptualisation: the counter-terrorist campus.

  10. Firmware, detector performance and first data of the AMIGA muon counters for the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Froehlich, Uwe

    2013-01-01

    With the Pierre Auger Observatory, being the largest air shower detector setup in the world, ultra-high-energy cosmic rays are studied with full trigger efficiency above E=3 x 10 18 eV. In order to achieve a more detailed understanding of cosmic ray physics at lower energies down to E∼10 17 eV, e.g. the transition from galactic to extragalactic sources and a possible change in the composition of the primary cosmic rays, the observatory is currently upgraded by the AMIGA enhancement (Auger Muons and Infill for the Ground Array). The muon counters of AMIGA, buried underground, will allow for dedicated measurements of the number of muons in air showers, thus increasing the precision in determining the type of the primary particle. Until middle of 2012, eight prototype muon counters of the AMIGA enhancement were installed at the experimental site of the Pierre Auger Observatory at Malargue, Argentina, forming one detector hexagon referred to as the pre-unitary cell (PUC). Each muon counter comprises a highly modular electronics readout system. Following the production of these systems, tests of single components as well as of the full readout electronics were carried out. In the framework of this thesis dedicated firmware, allowing for the commissioning and first data taking with the PUC, has been developed and tested. Among other features, this firmware includes a self-trigger of the muon counters as well as algorithms for the synchronization of the muon detector (MD) with the existing surface detector (SD) array. The functionality and performance of the electronics readout system with regard to this firmware has been investigated. In addition, first analyses of combined MD and SD data have been performed.

  11. Firmware, detector performance and first data of the AMIGA muon counters for the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Uwe

    2013-10-30

    With the Pierre Auger Observatory, being the largest air shower detector setup in the world, ultra-high-energy cosmic rays are studied with full trigger efficiency above E=3 x 10{sup 18} eV. In order to achieve a more detailed understanding of cosmic ray physics at lower energies down to E∼10{sup 17} eV, e.g. the transition from galactic to extragalactic sources and a possible change in the composition of the primary cosmic rays, the observatory is currently upgraded by the AMIGA enhancement (Auger Muons and Infill for the Ground Array). The muon counters of AMIGA, buried underground, will allow for dedicated measurements of the number of muons in air showers, thus increasing the precision in determining the type of the primary particle. Until middle of 2012, eight prototype muon counters of the AMIGA enhancement were installed at the experimental site of the Pierre Auger Observatory at Malargue, Argentina, forming one detector hexagon referred to as the pre-unitary cell (PUC). Each muon counter comprises a highly modular electronics readout system. Following the production of these systems, tests of single components as well as of the full readout electronics were carried out. In the framework of this thesis dedicated firmware, allowing for the commissioning and first data taking with the PUC, has been developed and tested. Among other features, this firmware includes a self-trigger of the muon counters as well as algorithms for the synchronization of the muon detector (MD) with the existing surface detector (SD) array. The functionality and performance of the electronics readout system with regard to this firmware has been investigated. In addition, first analyses of combined MD and SD data have been performed.

  12. Responding to Cyber Jihad: Towards an Effective Counter Narrative

    Directory of Open Access Journals (Sweden)

    Bibi van Ginkel

    2015-03-01

    Full Text Available “Who is in control of the narrative?” is the mantra that now echoes in the hallways of the EU’s headquarters in Brussels. Spurred in part by large-scale jihadist propaganda, approximately 20,000 people from 50 countries have joined the fight in Iraq and Syria. So far, authorities in their countries of origin have not been able to address the jihadist radicalisation messages transmitted via the internet and social media. Many new initiatives were recently announced, however, including the establishment of a European counter-narrative centre in Brussels. Research Fellow Dr. Bibi van Ginkel analyses the role of the internet and social media in processes of radicalisation. It offers an outline of the various aspects of the jihadist narrative, in order better to understand what message needs to be countered. The counter-actions against this cyber jihad can take different forms. Parallel to the way in which advertisement campaigns are tailored to sell products to a certain target group, strategic communication should take into account how a number of recurring elements play a role in the counter-messaging. The understanding of who the target group is, what jihadist narrative is used and how that message can be countered, who the credible messenger should be, and what medium can best be used to deliver the message are all relevant questions that can only be answered in a context-specific manner. The Research Paper concludes with several recommendations on how the recently announced new European counter-narrative centre can effectively contribute to the already diverse landscape of counter-narrative initiatives.

  13. On timing properties of the SRPO-304 proportional counters

    International Nuclear Information System (INIS)

    Gusev, A.A.; Pugacheva, G.I.

    1979-01-01

    Data of measurements of the signal delay time and the time of development of the discharge in a proportional counter filled with 90% Xe + 10% CH 4 mixture at 0.3 atm are presented. The measurements were carried out on muons of cosmic rays. Signal delay distribution for the proportional counter are given relative to the time of passage through it of a charged particle. The data obtained shows that the average delay time is 0.8 μs when a particle passes near the counter centre, whereas when it passes near its side wall the average delay time is 1.5 μs. The investigation of the discharge development time distribution was carried out for two values of the discriminator threshold: 6 and 20 keV. It was determined that the discharge development time distribution depends but little on the place of particle passage in a counter. The average discharge development time is 1.5 μs, with the maximum time beina 4.3 μs. It is shown that the resolution time of logical circuits will be near 4 μs when the counter is combined with scintillation detectors

  14. Picosecond-precision multichannel autonomous time and frequency counter

    Science.gov (United States)

    Szplet, R.; Kwiatkowski, P.; RóŻyc, K.; Jachna, Z.; Sondej, T.

    2017-12-01

    This paper presents the design, implementation, and test results of a multichannel time interval and frequency counter developed as a desktop instrument. The counter contains four main functional modules for (1) performing precise measurements, (2) controlling and fast data processing, (3) low-noise power suppling, and (4) supplying a stable reference clock (optional rubidium standard). A fundamental for the counter, the time interval measurement is based on time stamping combined with a period counting and in-period two-stage time interpolation that allows us to achieve wide measurement range (above 1 h), high precision (even better than 4.5 ps), and high measurement speed (up to 91.2 × 106 timestamps/s). The frequency is measured up to 3.0 GHz with the use of the reciprocal method. Wide functionality of the counter includes also the evaluation of frequency stability of clocks and oscillators (Allan deviation) and phase variation (time interval error, maximum time interval error, time deviation). The 8-channel measurement module is based on a field programmable gate array device, while the control unit involves a microcontroller with a high performance ARM-Cortex core. An efficient and user-friendly control of the counter is provided either locally, through the built-in keypad or/and color touch panel, or remotely, with the aid of USB, Ethernet, RS232C, or RS485 interfaces.

  15. A relativistic self-consistent model for studying enhancement of space charge limited emission due to counter-streaming ions

    Science.gov (United States)

    Lin, M. C.; Verboncoeur, J.

    2016-10-01

    A maximum electron current transmitted through a planar diode gap is limited by space charge of electrons dwelling across the gap region, the so called space charge limited (SCL) emission. By introducing a counter-streaming ion flow to neutralize the electron charge density, the SCL emission can be dramatically raised, so electron current transmission gets enhanced. In this work, we have developed a relativistic self-consistent model for studying the enhancement of maximum transmission by a counter-streaming ion current. The maximum enhancement is found when the ion effect is saturated, as shown analytically. The solutions in non-relativistic, intermediate, and ultra-relativistic regimes are obtained and verified with 1-D particle-in-cell simulations. This self-consistent model is general and can also serve as a comparison for verification of simulation codes, as well as extension to higher dimensions.

  16. Digital signal processing for He3 proportional counter

    International Nuclear Information System (INIS)

    Ahmadov, Q.S.; Institute of Radiation Problems, ANAS, Baku

    2011-01-01

    Full text: Data acquisition systems for nuclear spectroscopy have traditionally been based on systems with analog shaping amplifiers followed by analog-to-digital converters. Recently, however, new systems based on digital signal processing allow us to replace the analog shaping and timing circuitry the numerical algorithms to derive properties of the pulse such as its amplitude. DSP is a fully numerical analysis of the detector pulse signals and this technique demonstrates significant advantages over analog systems in some circumstances. From a mathematical point of view, one can consider the signal evolution from the detector to the ADC as a sequence of transformations that can be described by precisely defined mathematical expressions.Digital signal processing with ADCs has the possibility to utilize further information on the signal pulses from radiation detectors [1] [2]. In the experiment each step of the signal generation in the 3He filled proportional counter was described using digital signal processing techniques (DSP). The electronic system has consisted of a detector, a preamplifier and a digital oscilloscope. The pulses from the detector were digitized using a OTSZS-02 (250USB)-4 digital storage oscilloscope from ZAO R UDNEV-SHILYAYEV . This oscilloscope allowed signal digitization with accuracy of 8 bit(256 levels) and with frequency of up to 5.10''8 samples/s. As a neutron source was used Cf-252.To obtain detector output current pulse I(t) created by the motions of the ions/electrons pairs was written an algorithm which can easily be programmed using modern computer programming languages

  17. Monte Carlo simulation of neutron counters for safeguards applications

    International Nuclear Information System (INIS)

    Looman, Marc; Peerani, Paolo; Tagziria, Hamid

    2009-01-01

    MCNP-PTA is a new Monte Carlo code for the simulation of neutron counters for nuclear safeguards applications developed at the Joint Research Centre (JRC) in Ispra (Italy). After some preliminary considerations outlining the general aspects involved in the computational modelling of neutron counters, this paper describes the specific details and approximations which make up the basis of the model implemented in the code. One of the major improvements allowed by the use of Monte Carlo simulation is a considerable reduction in both the experimental work and in the reference materials required for the calibration of the instruments. This new approach to the calibration of counters using Monte Carlo simulation techniques is also discussed.

  18. Lessons from History for Counter-Terrorism Strategic Communications

    Directory of Open Access Journals (Sweden)

    Haroro J. Ingram

    2016-06-01

    Full Text Available Drawing on the Counter-terrorism Strategic Communication (CTSC Project’s research paper “A Brief History of Propaganda during Conflict“, this Policy Brief lays out the key policy-relevant lessons for developing effective counter-terrorism strategic communications. It presents a framework of interrelated macro-, mezzo- and micro-level considerations for maximizing the efficacy of not just a strategic communications campaign but message design. Historical examples are drawn upon to illustrate their practical application. The Policy Brief concludes by analysing four key strategic-policy principles arguing that a counter-terrorism strategic communications campaign is more likely to be successful if it is based on the cumulative effects of a multidimensional messaging strategy.

  19. Emergent information technologies and enabling policies for counter-terrorism

    CERN Document Server

    Popp, R

    2006-01-01

    Explores both counter-terrorism and enabling policy dimensions of emerging information technologies in national security After the September 11th attacks, "connecting the dots" has become the watchword for using information and intelligence to protect the United States from future terrorist attacks. Advanced and emerging information technologies offer key assets in confronting a secretive, asymmetric, and networked enemy. Yet, in a free and open society, policies must ensure that these powerful technologies are used responsibly, and that privacy and civil liberties remain protected. Emergent Information Technologies and Enabling Policies for Counter-Terrorism provides a unique, integrated treatment of cutting-edge counter-terrorism technologies and their corresponding policy options. Featuring contributions from nationally recognized authorities and experts, this book brings together a diverse knowledge base for those charged with protecting our nation from terrorist attacks while preserving our civil liberti...

  20. Development of failure-detecting device for γ radioimmunoassay counter

    International Nuclear Information System (INIS)

    Shao Xianzhi; Zhang Bingfeng

    1997-01-01

    A failures-detecting device based on single chip microcomputer technique for detecting of failures of γ radioimmunoassay counter is developed. The device can output signals of variable amplitude and frequency similar to the pulse of γ particle for shooting problem parts of γ counter's detecting system. By automatically comparing the shapes and amplitudes of the two signals to and from an amplifier unit, the device can distinguish if the amplifier unit works normally. The differential-input amplifier circuit gives 0.1% accuracy for the measurement of the stability of high voltage. The pulse widen circuit of this device allows for middle speed A/D detecting of periodical low-frequency pulse waves of micro-second width. This device is used specifically for the maintaining and failure-detecting of γ radioimmunoassay counter

  1. Measurements of Radon Concentration in Yemen Using Spark Counter

    International Nuclear Information System (INIS)

    Arafa, W.; Abou-Leila, M.; Hafiz, M.E.; Al-Glal, N.

    2011-01-01

    Spark counter has been designed and realized and the optimum applied voltage was found to be 600 V. Excellent consistent agreements was observed between counted number of tracks by spark counter and reading by optical microscope. Radon concentration in some houses in Sana'a and Hodeidah cities in Yemen had been performed using LR-115 SSNTD and spark counter system. The average radon concentration in both cities was far lower the alert value. The results showed that radon concentration in the metropolitan area Sana'a was higher than that in Hodeidah city. Also, it was observed that old residential houses had higher levels of radon concentrations have compared to newly built houses in the metropolitan area Sana'a

  2. Wind tunnel tests of stratospheric airship counter rotating propellers

    Directory of Open Access Journals (Sweden)

    Yaxi Chen

    2015-01-01

    Full Text Available Aerodynamic performance of the high-altitude propeller, especially the counter rotation effects, is experimentally studied. Influences of different configurations on a stratospheric airship, included 2-blade counter-rotating propeller (CRP, dual 2-blade single rotation propellers (SRPs and 4-blade SRP, are also indicated. This research indicates that the effect of counter rotation can greatly improve the efficiency. It shows that the CRP configuration results in a higher efficiency than the dual 2-blade SRPs configuration or 4-blade SRP configuration under the same advance ratio, and the CRP configuration also gains the highest efficiency whether under the situation of providing the same trust or absorbing the same power. It concludes that, for a stratospheric airship, the CRP configuration is better than the multiple SRPs configuration or a multi-blade SRP one.

  3. A semiconductor counter telescope for neutron reaction studies

    Energy Technology Data Exchange (ETDEWEB)

    Lalovic, B I; Ajdacic, V S [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)

    1963-12-15

    A counter telescope consisting of two or three semiconductor counters for {delta}E/{delta}x vs. E analysis was made for studying nuclear reactions induced by 14.4 MeV neutrons. Various factors important for the telescope performance are discussed in details and some solutions for getting an optimum resolution and a low background are given. Protons, deuterons and alpha particles resulting from scattering and reactions of 14.4 MeV neutrons on deuterium, tritium, praseodymium and niobium were detected, and pulses from the counters recorded on a two-dimensional analyzer. These experiments have shown that the telescope compares favorably with other types of telescopes with regards to the upper limit of neutron flux which can be used, (DELTADELTA)x and E resolution, versatility and compactness (author)

  4. An acoustical bubble counter for superheated drop detectors

    International Nuclear Information System (INIS)

    Taylor, C.; Montvila, D.; Flynn, D.; Brennan, C.; D'Errico, F.

    2006-01-01

    A new bubble counter has been developed based on the well-established approach of detecting vaporization events acoustically in superheated drop detectors (SDDs). This counter is called the Framework Scientific ABC 1260, and it represents a major improvement over prior versions of this technology. By utilizing advanced acoustic pattern recognition software, the bubble formation event can be differentiated from ambient background noise, as well as from other acoustic signatures. Additional structural design enhancements include a relocation of the electronic components to the bottom of the device; thus allowing for greater stability, easier access to vial SDDs without exposure to system electronics. Upgrades in the electronics permit an increase in the speed of bubble detection by almost 50%, compared with earlier versions of the counters. By positioning the vial on top of the device, temperature and sound insulation can be accommodated for extreme environments. Lead shells can also be utilized for an enhanced response to high-energy neutrons. (authors)

  5. An acoustical bubble counter for superheated drop detectors.

    Science.gov (United States)

    Taylor, Chris; Montvila, Darius; Flynn, David; Brennan, Christopher; d'Errico, Francesco

    2006-01-01

    A new bubble counter has been developed based on the well-established approach of detecting vaporization events acoustically in superheated drop detectors (SDDs). This counter is called the Framework Scientific ABC 1260, and it represents a major improvement over prior versions of this technology. By utilizing advanced acoustic pattern recognition software, the bubble formation event can be differentiated from ambient background noise, as well as from other acoustic signatures. Additional structural design enhancements include a relocation of the electronic components to the bottom of the device; thus allowing for greater stability, easier access to vial SDDs without exposure to system electronics. Upgrades in the electronics permit an increase in the speed of bubble detection by almost 50%, compared with earlier versions of the counters. By positioning the vial on top of the device, temperature and sound insulation can be accommodated for extreme environments. Lead shells can also be utilized for an enhanced response to high-energy neutrons.

  6. A high-efficiency neutron coincidence counter for small samples

    International Nuclear Information System (INIS)

    Miller, M.C.; Menlove, H.O.; Russo, P.A.

    1991-01-01

    The inventory sample coincidence counter (INVS) has been modified to enhance its performance. The new design is suitable for use with a glove box sample-well (in-line application) as well as for use in the standard at-line mode. The counter has been redesigned to count more efficiently and be less sensitive to variations in sample position. These factors lead to a higher degree of precision and accuracy in a given counting period and allow for the practical use of the INVS counter with gamma-ray isotopics to obtain a plutonium assay independent of operator declarations and time-consuming chemicals analysis. A calculation study was performed using the Los Alamos transport code MCNP to optimize the design parameters. 5 refs., 7 figs., 8 tabs

  7. A miniature spark counter for public communication and education

    International Nuclear Information System (INIS)

    Mao, C.H.; Weng, P.S.

    1987-01-01

    The fabrication of a miniature spark counter for public communication and education using naturally occurring radon as a radioactive source without involving any man-made radioactivity is described. The battery-powered miniature spark counter weighs 2.07 kg with a volume of 4.844 x 10/sup -4/ m/sup 3/. The circuitry consists of seven major components: timer, high-voltage power supply, attenuator, noninverting amplifier, low-pass filter, one-shot generator, and counter. Cellulose nitrate films irradiated with alpha particles from radon emanating from soil were etched and counted. The visible sparks during counting are rather heuristic, which can be used to demonstrate naturally occurring radioactivity in classrooms or showplaces

  8. Gold leaf counter electrodes for dye-sensitized solar cells

    Science.gov (United States)

    Shimada, Kazuhiro; Toyoda, Takeshi

    2018-03-01

    In this study, a gold leaf 100 nm thin film is used as the counter electrode in dye-sensitized solar cells. The traditional method of hammering gold foil to obtain a thin gold leaf, which requires only small amounts of gold, was employed. The gold leaf was then attached to the substrate using an adhesive to produce the gold electrode. The proposed approach for fabricating counter electrodes is demonstrated to be facile and cost-effective, as opposed to existing techniques. Compared with electrodes prepared with gold foil and sputtered gold, the gold leaf counter electrode demonstrates higher catalytic activity with a cobalt-complex electrolyte and higher cell efficiency. The origin of the improved performance was investigated by surface morphology examination (scanning electron microscopy), various electrochemical analyses (cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy), and crystalline analysis (X-ray diffractometry).

  9. Proton-recoil proportional counter tests at TREAT

    International Nuclear Information System (INIS)

    Fink, C.L.; Eichholz, J.J.; Burrows, D.R.; DeVolpi, A.

    1979-01-01

    A methane filled proton-recoil proportional counter will be used as a fission neutron detector in the fast-neutron hodoscope. To provide meaningful fuel-motion information the proportional counter should have: a linear response over a wide range of reactor powers background ratio (the number of high energy neutrons detected must be maximized relative to low energy neutrons, and gamma ray sensitivity must be kept small); and a detector efficiency for fission neutrons above 1 MeV of approximately 1%. In addition, it is desirable that the detector and the associated amplifier/discriminator be capable of operating at counting rates in excess of 500 kHz. This paper reports on tests that were conducted on several proportional counters at the TREAT reactor

  10. DEVELOPMENT OF HETEROGENEOUS PROPORTIONAL COUNTERS FOR NEUTRON DOSIMETRY.

    Science.gov (United States)

    Forouzan, Faezeh; Waker, Anthony J

    2018-01-10

    The use of a custom-made cylindrical graphite proportional counter (Cy-GPC) along with a cylindrical tissue equivalent proportional counter (TEPC) for neutron-gamma mixed-field dosimetry has been studied in the following steps: first, the consistency of the gamma dose measurement between the Cy-TEPC and the Cy-GPC was investigated over a range of 20 keV (X-ray) to 0.661 MeV (Cs-137 gamma ray). Then, with both the counters used simultaneously, the neutron and gamma ray doses produced by a P385 Neutron Generator (Thermo Fisher Scientific) together with a Cs-137 gamma source were determined. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. 4-GHz counters bring synthesizers up to speed

    Science.gov (United States)

    Lee, F.; Miller, R.

    1984-06-01

    The availability of digital IC counters built on GaAs makes direct frequency division in microwave synthesizers possible. Four GHz is the highest clock rate achievable in production designs. These devices have the ability to drive TTL/CMOS logic, and the counter can be connected directly to single-chip frequency synthesizers controllers. A complete microwave sythesizer is formed by two chips and a voltage-controlled oscillator (VCO). The advantages of GaAs are discussed along with flip-flop basics, aspects of device fabrication, and the characteristics of GaAs MESAFETs. Attention is given to a GaAs prescaler usable for direct conversion, four kinds of flip-flops in a divide-by-two mode, and seven-stage binary ripple counters.

  12. Interactive hypermedia training manual for spent-fuel bundle counters

    International Nuclear Information System (INIS)

    Basso, R.A.

    1990-07-01

    Spent-fuel bundle counters, developed by the Canadian Safeguards Support Program for the International Atomic Energy Agency, provide a secure and independent means of counting the number of irradiated fuel bundles discharged into the fuel storage bays at CANDU nuclear power stations. Paper manuals have been traditionally used to familiarize IAEA inspectors with the operation, maintenance and extensive reporting capabilities of the bundle counters. To further assist inspectors, an interactive training manual has been developed on an Apple Macintosh computer using hypermedia software. The manual uses interactive animation and sound, in conjunction with the traditional text and graphics, to simulate the underlying operation and logic of the bundle counters. This paper presents the key features of the interactive manual and highlights the advantages of this new technology for training

  13. Forensic Speaker Recognition Law Enforcement and Counter-Terrorism

    CERN Document Server

    Patil, Hemant

    2012-01-01

    Forensic Speaker Recognition: Law Enforcement and Counter-Terrorism is an anthology of the research findings of 35 speaker recognition experts from around the world. The volume provides a multidimensional view of the complex science involved in determining whether a suspect’s voice truly matches forensic speech samples, collected by law enforcement and counter-terrorism agencies, that are associated with the commission of a terrorist act or other crimes. While addressing such topics as the challenges of forensic case work, handling speech signal degradation, analyzing features of speaker recognition to optimize voice verification system performance, and designing voice applications that meet the practical needs of law enforcement and counter-terrorism agencies, this material all sounds a common theme: how the rigors of forensic utility are demanding new levels of excellence in all aspects of speaker recognition. The contributors are among the most eminent scientists in speech engineering and signal process...

  14. TOP counter for particle identification at the Belle II experiment

    Energy Technology Data Exchange (ETDEWEB)

    Inami, Kenji

    2014-12-01

    Ring imaging Cherenkov counter, named TOP counter, utilizing precise photon detection timing has been developed as a particle identification detector for the Belle II experiment. The real size prototype has been produced and tested with 2 GeV positrons at Spring-8 LEPS beam line. The quartz radiator production and assembling with microchannel plate photomultipliers was successfully carried out. The beam test data shows good agreement with full Monte-Carlo simulation results in the ring image and the distribution of number of detected photons and timing information. - Highlights: • TOP counter was developed as a particle identification detector for the Belle II experiment. • The real size prototype was produced and tested with 2 GeV positrons. • The quartz radiator production and assembling with MCP-PMT was successfully carried out. • The beam test data shows good agreement with full Monte-Carlo simulation results.

  15. Prototype of IGZO-TFT preamplifier and analog counter for pixel detector

    International Nuclear Information System (INIS)

    Shimazoe, K.; Koyama, A.; Takahashi, H.; Shindoh, T.; Miyoshi, H.

    2017-01-01

    IGZO-TFT (Indium Galium Zinc Oxide-Thin Film Transistor) is a promising technology for controlling large display areas and large area sensors because of its very low leakage current in the off state and relatively low cost. IGZO has been used as a switching gate for a large area flat-panel detector. The photon counting capability for X-ray medical imaging has been investigated and expected for low-dose exposure and material determination. Here the design and fabrication of a charge sensitive preamplifier and analog counter using IGZO-TFT processes and its performance are reported for the first time to be used for radiation photon counting applications.

  16. Cryogenic readout for multiple VUV4 Multi-Pixel Photon Counters in liquid xenon

    Science.gov (United States)

    Di Giovanni, A.

    2018-03-01

    This work concerned the preliminary tests and characterization of a cryogenic preamplifier board for an array made of 16 S13370-3050CN (VUV4 family) Multi-Pixel Photon Counters manufactured by Hamamatsu and operated at liquid xenon temperature. The proposed prototype is based on the use of the Analog Devices AD8011 current feedback operational amplifier. The detector allows for single photon detection, making this device a promising choice for the future generation of neutrino and dark matter detectors based on liquid xenon targets.

  17. Quality Assurance of Pixel Hybrid Photon Detectors for the LHCb Ring Imaging Cherenkov Counters

    CERN Document Server

    Carson, Laurence

    Pion/kaon discrimination in the LHCb experiment will be provided by two Ring Imaging Cherenkov (RICH) counters. These use arrays of 484 Hybrid Photon Detectors (HPDs) to detect the Cherenkov photons emitted by charged particles traversing the RICH. The results from comprehensive quality assurance tests on the 550 HPDs manufactured for LHCb are described. Leakage currents, dead channel probabilities, dark count rates and ion feedback rates are reported. Furthermore, measurements carried out on a sample of tubes to determine the efficiency of the HPD pixel chip by measuring the summed analogue response from the backplane of the silicon sensor are described.

  18. About the distribution of delays in G.M counters

    International Nuclear Information System (INIS)

    Picard, E.; Rogozinski, A.

    1954-01-01

    We measure, with an oscillograph method the global time that pass between the time that a particle in a determined region of the studied counter and the answer of the amplifier associated to the counter. This delay is composed of the latency time T l and the T q delay, that result from the rise time finished of the impulse and whose value depends of the sensitivity threshold of the amplifier. The selection of (cosmic) particles generating discharge in the studied counter is obtained thanks to a telescope of two meters in coincidence whose opening is limited by a group of four counters in anti-coincidence with the first. The meter is arranged so that the median plan of the telescope crosses to a variable distance d of his axial thread. The measures have been done for different securities of the distance d and of the over-voltage V s applied to the counter. The results show that the statistical distribution of the delays is more spread especially when d is bigger and V s more reduced. The average values of the observed delays vary of 7.10 -8 s for d = 0 and V s es = 200 V, to 90.10 -8 s for d = 1,9 cm and V s = 50 V. The mobility of an free electron within the gaseous mixture filling the counter under a pressure of 10 cm.Hg was found equal: (2,1 ±0,2).10 4 cm 2 .s -1 .V -1 . (author) [fr

  19. Prevent: A Fragmented Counter-Terrorism Strategy

    Science.gov (United States)

    2015-05-21

    ethnicity, religion, class, gender , language, accent, dress, political ideology or any combination of these factors may serve to delineate the sub...against another. Lack of parity in resourcing compounds the issue of a community that is securitize in nature. Complex adaptive systems theory... Parity in emphasis would not only garnish a greater level of community trust for all forms of terrorism, but it would deemphasize the need of the current

  20. A large multi-cell threshold gas Cerenkov counter

    International Nuclear Information System (INIS)

    Declais, Y.; Aubert, J.J.; Bassompierre, G.; Payre, P.; Thenard, J.M.; Urban, L.

    1980-08-01

    A large multi-cell threshold gas Cerenkov counter consisting of 78 cells has been built for use in a high energy muon scattering experiment at CERN (European Muon Collaboration). It is used with neon, nitrogen or a mixture of those two gases, allowing the pion threshold to be varied between 6 and 20 GeV/c. The sensitive region of the counter has a length of 4.0 m and entrance and exit windows of 1.1 x 2.4 m 2 and 2.4 x 5.0 m 2 , respectively

  1. Geiger counters of gamma rays with a bismuth cathode

    International Nuclear Information System (INIS)

    Meunier, R.; Legrand, J.P.

    1953-01-01

    Geiger Muller counters present a lake of efficiency of some per cent, for the γ radiations. In the region 0,3 - 1 MeV, a substantial growth of their output can be obtained by a special construction of their cathode. In accordance with previous works, we constructed some counter of formed cathode by a pleated copper wire fencing covered of Bi by electrolysis. The successive modifications brought to a cylindrical conventional cathode in sheet metal of copper, that succeeds to this type of cathode, drive to an improvement of the output. (M.B.) [fr

  2. Proportional counter response calculations for gallium solar neutrino detectors

    International Nuclear Information System (INIS)

    Kouzes, R.T.; Reynolds, D.

    1989-01-01

    Gallium bases solar neutrino detectors are sensitive to the primary pp reaction in the sun. Two experiments using gallium, SAGE in the Soviet Union and GALLEX in Europe, are under construction and will produce data by 1989. The radioactive /sup 71/Ge produced by neutrinos interacting with the gallium detector material, is chemically extracted and counted in miniature proportional counters. A number of calculations have been carried out to simulate the response of these counters to the decay of /sup 71/Ge and to background events

  3. Gas scintillation proportional counters for x-ray synchrotron applications

    International Nuclear Information System (INIS)

    Smith, A.; Bavdaz, M.

    1992-01-01

    Gas scintillation proportional counters (GSPCs) as x-ray detectors provide some advantages and disadvantages compared with proportional counters. In this paper the various configurations of xenon filled GSPC are described including both imaging and nonimaging devices. It is intended that this work be used to configure a GSPC for a particular application and predict its general performance characteristics. The general principles of operation are described and the performance characteristics are then separately considered. A high performance, imaging, driftless GSPC is described in which a single intermediate window is used between the PMT and gas cell

  4. Search for an optimum time response of spark counters

    International Nuclear Information System (INIS)

    Devismes, A.; Finck, Ch.; Kress, T.; Gobbi, A.; Eschke, J.; Herrmann, N.; Hildenbrand, K.D.; Koczon, P.; Petrovici, M.

    2002-01-01

    A spark counter of the type developed by Pestov has been tested with the aim of searching for an optimum time response function, changing voltage, content of noble and quencher gases, pressure and energy-loss. Replacing the usual argon by neon has brought an improvement of the resolution and a significant reduction of tails in the time response function. It has been proven that a counter as long as 90 cm can deliver, using neon gas mixture, a time resolution σ<60 ps with about 1% absolute tail and an efficiency of about 90%

  5. Introduction to Neutron Coincidence Counter Design Based on Boron-10

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2012-01-22

    The Department of Energy Office of Nonproliferation Policy (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is ultimately to design, build and demonstrate a boron-lined proportional tube based alternative system in the configuration of a coincidence counter. This report, providing background information for this project, is the deliverable under Task 1 of the project.

  6. An integrated photosensor readout for gas proportional scintillation counters

    International Nuclear Information System (INIS)

    Lopes, J.A.M.; Santos, J.M.F. dos; Conde, C.A.N.

    1996-01-01

    A xenon gas proportional scintillation counter has been instrumented with a novel photosensor that replaces the photomultiplier tube normally used to detect the VUV secondary scintillation light. In this implementation, the collection grid of a planar gas proportional scintillation counter also functions as a multiwire proportional chamber to amplify and detect the photoelectrons emitted by a reflective CsI photocathode in direct contact with the xenon gas. This integrated concept combines greater simplicity, compactness, and ruggedness (no optical window is used) with low power consumption. An energy resolution of 12% was obtained for 59.6 keV x-rays

  7. Counter-transference reactions contributing to completed suicide.

    Science.gov (United States)

    Modestin, J

    1987-12-01

    Counter-transference reactions are frequently elicited while treating suicidal patients and they may contribute to the patient's committing suicide. Therapeutic constellations including the failure of the therapist to (1) cope with the patient's aggressiveness, (2) tolerate the patient's dependency, (3) handle the erotic transference adequately and (4) preserve loyalty towards the patient; they have all been identified as being responsible for a therapeutic impasse with fatal consequences. Knowledge of the therapeutic constellations especially prone to facilitate negative counter-transference reactions may help the therapist to master them effectively.

  8. Proportional counter with uniform electric field with Penning's mixture

    International Nuclear Information System (INIS)

    Pawlowski, Z.; Marzec, J.; Zaremba, K.

    1984-01-01

    Some calculations are given and the design of proportional counters with a homogeneous electric field filled with Penning's mixtures, which ensure the best energy resolution is described. The counters with mixtures of Ne+Ar, Ne+CH 4 , Ne+CO 2 and Ar+C 2 H 2 have been checked. The admixtures (Ar, CH 4 , CO 2 , C 2 H 2 ) constitute from 0.1 to 2%, with pressure from 125 Tr to 760 Torr. The best energy resolution has been obtained for the mixture of Ne+1%CH 4 at the pressure of 190 Torr

  9. Energy resolution limitations in a gas scintillation proportional counter

    International Nuclear Information System (INIS)

    Simons, D.G.; de Korte, P.A.J.; Peacock, A.; Bleeker, J.A.M.

    1985-01-01

    An investigation is made of the factors limiting the energy resolution of a gas scintillation proportional counter (GSPC). Several of these limitations originate in the drift region of such a counter and data is presented, giving a quantitative description of those effects. Data is also presented of a GSPC without a drift region, that therefore largely circumvents most of those degrading factors. The results obtained so far indicate that in that detector the limitation to the resolution is most probably due to cleanliness of the gas. Further research is underway in order to assess quantitatively the limiting factors in such a driftless GSPC

  10. The parallel plate avalanche counter: a simple, rugged, imaging X-ray counter

    International Nuclear Information System (INIS)

    Joensen, K.D.; Budtz-Joergensen, C.; Bahnsen, A.; Madsen, M.M.; Olesen, C.; Schnopper, H.W.

    1995-01-01

    A two-dimensional parallel gap proportional counter has been developed at the Danish Space Research Institute. Imaging over the 120 mm diameter active area is obtained using the positive ion component of the avalanche signals as recorded by a system of wedge- and strip-electrodes. An electronically simple, but very effective background rejection is obtained by using the fast electron component of the avalanche signal. Gas gains up to 8x10 5 have been achieved. An energy-resolution of 16% and a sub-millimeter spatial resolution have been measured at 5.9 keV for an operating gas gain of 10 5 . In principle, the position coordinates are linear functions of electronic readouts. The present model, however, exhibits non-linearities, caused by imperfections in the wedge and strip-electrode pattern. These non-linearities are corrected by using a bilinear correction algorithm. We conclude that the rugged construction, the simple electronics, the effectiveness of the background rejection and the actual imaging performance makes this a very attractive laboratory detector for low and intermediate count rate imaging applications. ((orig.))

  11. Utilization of over the counter medication among pregnant women; a cross-sectional study conducted at Isra University Hospital, Hyderabad.

    Science.gov (United States)

    Bohio, Rabail; Brohi, Zahida Perveen; Bohio, Farrukh

    2016-01-01

    To determine the frequency of use of over-the-counter medication among pregnant women, types of medicines, source of information and reason to opts for self-medication. The descriptive cross-sectional study was conducted at Isra University Hospital, Hyderabad, Pakistan, from April 14 to October 14, 2014, and comprised pregnant women who were interviewed face to face. Data was collected on a proforma comprising demographic data, practice of using over-the-counter medications before and during pregnancy, type of medicines, illnesses, knowledge about the medicines, source of recommendation and reason for practicing it. Data was analysed on SPSS 16. The mean age of 351 patients in the study was 26.19±4.82 years (range: 18-45 years).The mean gestational age was 26.28±10.42. Overall, 223(63.5%) patients were using over-the-counter drugs before pregnancy; 128(36.5%) had used them in previous pregnancy; and 133(37.9%) were using them during the current pregnancy. Most common medication used was acetaminophen 58(43.6%), headache was the most common illness 80(60.2%). A total of 103(77.4%) had no knowledge about the medicines. A significant number of pregnant women indulged in the practice of using over-the-counter medication.

  12. Turbulent current layer equilibrium and current layer of the Earth magnetotail

    International Nuclear Information System (INIS)

    Antonova, E.E.; Ovchinnikov, I.L.

    1996-01-01

    Analysis of distribution of plasma and magnetic field concentration in the unidimensional current layer under the condition of equality of the current inflowing into the layer and the counter diffusion current by various dependences of the regular velocity and the turbulent diffusion coefficient on the magnetic field. Corresponding two-dimensional solutions are obtained in the tail approximation. Comparison of the model turbulent current layer with characteristics of the plasma layer of the Earth magnetosphere tail is carried out. 16 refs., 3 figs

  13. 35 years of existence of whole-body counter in the Czech Republic - experiences and prospects

    International Nuclear Information System (INIS)

    Malatova, I.; Foltanova, L.; Cespirova, I.

    1998-01-01

    A whole-body counter was built up in the Czech Republic in 1962, this at the then Institute of the Hygiene of Labour and Occupational Diseases. The shielding was made of steel plates taken from Tiger tanks which remained in the country as aftermath of World War II. The detecting and evaluating parts of the counter were upgraded gradually. The original 4 scintillator detectors (10.16 cm x 12.7 cm in size) were replaced with an HPGe semiconductor detector exhibiting a roughly fifty-fold better resolution, owing to which radionuclide activities can be determined in complex matrices. Currently, the whole-body counter is equipped with a high-purity Ge detector displaying a relative efficiency of 120%, special detectors for low-energy gamma radiation, so-called LEGe detectors which are employed during the determination of radionuclides in the individual organs. The facility is applied to the monitoring of internal contamination in persons handling unsealed sources, monitoring in cases of suspect accidents associated with internal contamination of humans, as well as to the determination of internal contamination in epidemiological studies. In the past, a group of persons contaminated with radioactive fluorescent dyes which contained 226 Ra and 90 Sr, and a group of patients with applied thorotrast were also examined. Currently, methods which are under development are aimed at the determination of 210 Pb in the skulls of people who have been exposed to elevated radon concentrations in dwellings for a long time, and the determination of 241 Am in human bodies and their individual organs

  14. Reactance and Coping Responses to Tobacco Counter-Advertisements.

    Science.gov (United States)

    Wehbe, Michelle S; Basil, Michael; Basil, Debra

    2017-07-01

    Tobacco prevention messages generally take one of three tactics: They can be educational, attack the tobacco industry, or attack particular brands. Being a smoker and smoking a particular brand may form an essential part of a person's self-identity. As such, reactance theory suggests that attack messages can unintentionally attack smokers' self-image. A 2 × 2 × 2 × 2 experiment using six different messages and 260 respondents tested whether smokers have different reactions to tobacco counter-advertisements than nonsmokers. It also examined whether attacking a smoker's brand leads to greater reactance and other maladaptive responses compared to attacking other brands. Consistent with predictions, smokers reported more maladaptive coping responses and fewer adaptive coping responses to tobacco counter-ads than nonsmokers. The study also reveals differences attributable to brand identification. These findings suggest that interventions should consider different counter-advertising tactics for smokers and nonsmokers. Similar admonitions may apply to counter-advertising strategies on other health issues.

  15. Slim by Design: Kitchen Counter Correlates of Obesity

    Science.gov (United States)

    Wansink, Brian; Hanks, Andrew S.; Kaipainen, Kirsikka

    2016-01-01

    Background: The home is one place where people can control what foods are available and how the environment is arranged. Given the impact of environments on health, the objective of this study is to determine whether the presence of foods on a person's kitchen counter are associated with their body mass index (BMI). Method: In Study 1, a…

  16. Recognizing, explaining and countering norm transgressive behaviour on social media

    NARCIS (Netherlands)

    Padje, E.D.H.

    2016-01-01

    In this thesis, it is researched how norm transgressive behaviour exhibited on the Dutch domains of social media can be recognized, explained and countered. An analysis of four comment threads is conducted, of which the comments can be found on the Facebook pages of three Dutch news sites and on a

  17. Losing the Plot: Narrative, Counter-Narrative and Violent Extremism

    Directory of Open Access Journals (Sweden)

    Andrew Glazzard

    2017-05-01

    Full Text Available Counter-terrorist practitioners and policy makers appear to be very interested in narrative. They often describe the worldview of violent Islamist groups and movements as the ‘jihadi narrative’, while their efforts to confront terrorist propaganda are usually labelled as ‘counter-narrative’ or ‘alternative narrative’. However, while the counter-narrative approach has gained widespread acceptance in governments, think-tanks and civil society organisations, it is built on very shaky theoretical and empirical foundations. Some valuable theoretical contributions to the study of violent extremist narrative have been made by psychologists in particular, but there is one discipline which is conspicuous by its absence from the field: literary studies. This paper makes a case for the value of studying violent extremist narratives as narratives in the literary sense. By employing the tools and techniques of literary criticism, violent extremist communication can be revealed as not only potentially persuasive, but also creative and aesthetically appealing: terrorists inspire their followers, they don’t merely persuade them. Understanding the creative sources of this inspiration is vital if counter-narrative is to succeed in presenting an alternative to the propaganda of violent extremist groups.

  18. Stress and use of over-the-counter analgesics

    DEFF Research Database (Denmark)

    Koushede, Vibeke Jenny; Ekholm, Ola; Holstein, Bjørn E

    2011-01-01

    To examine the prevalence of over-the-counter analgesic (OTCA) use and perceived stress among 25 to 44-year-old men and women from 1994 to 2005; to examine the association between stress and OTCA use over time, and to explore whether the association attenuates when controlled by stress...

  19. Quality analysis during production of car counter cases

    Directory of Open Access Journals (Sweden)

    Marta Jagusiak-Kocik

    2014-07-01

    Full Text Available In the chapter the company operating in the plastic industry was presented. The car counter case to Fiat was the main subject. The production process of the research product depicted technologically was presented. Hierarchy of the nonconformities with use of ParetoLorenz diagram was made.

  20. Crypto and empire: the contradictions of counter-surveillance advocacy

    NARCIS (Netherlands)

    Gürses, S.; Kundnani, A.; Van Hoboken, J.

    2016-01-01

    Since Edward Snowden’s revelations of US and UK surveillance programs, privacy advocates, progressive security engineers, and policy makers have been seeking to win majority support for countering surveillance. The problem is framed as the replacement of targeted surveillance with mass surveillance