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.

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

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

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.

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 ...

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.

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

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

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)

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

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.

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.

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 [...

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.)

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.

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.

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.

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.

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.

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- ...

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.

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.

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)

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...

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

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)

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.

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)

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.

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

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.

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)

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.

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.

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

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...

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.)

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.

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.

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.

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...

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.

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

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

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

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.

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)

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.

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

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)

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.

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.

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)

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...

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.

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

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.

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

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.

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

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.

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)

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.

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.

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

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.

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.

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.

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.

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

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.

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.

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.

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)

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.

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.

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.)

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)

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)

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.

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)

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...

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.

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

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

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

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.

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.

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.

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.

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

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

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.

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)

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.

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)

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

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.

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

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)

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)

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

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.

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)

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

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)

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...

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.

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.

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.

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.

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.

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

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.

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 ...

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.

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)

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

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...

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.

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.

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

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....

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)

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.

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.

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.

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

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.

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.

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

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

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.

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.

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.

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...

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

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.

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)

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. 

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.

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.

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.

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.

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

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.

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

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

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.

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.

Proton-recoil proportional-counter array for neutron-image construction

International Nuclear Information System (INIS)

Fink, C.L.; Eichholz, J.J.; DeVolpi, A.

1984-01-01

The fuel-motion measurement capability of the fast-neutron hodoscope has been upgraded by the addition of a 360-detector proton-recoil proportional-counter array, which detects high-energy fission neutrons. The current sensitive amplifier/discriminator module for each detector fits into a 12.7 by 12.7 by 102 mm package and cost less than $100 per module. It has a 50 ns rise time, a noise level of 100 nA, and a deadtime per event of 200 ns. Provision has been provided for the independent adjustment of the input current versus discriminator voltage for each module. The new proportional-counters cost approximately $400 each. Each detector has been tested to have the same gain versus voltage response. A space-charge model relating count-rate changes to space-charge effects has also been developed. The new detector array has been operational for approximately two years and has become the main detector system in fuel-motion analysis. It has significantly improved the linearity, stability, count-rate capability, and setup ease of the hodoscope

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.

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

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.)

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%).

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.

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.

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

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

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,

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....

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.)

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.

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.

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

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.

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

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

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

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)

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.

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.

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

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.

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.

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)

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

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

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.

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.

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.

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

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…

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...

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.

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...

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

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...

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...

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.

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.

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.

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...

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...

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)

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.)

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

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

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.

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)

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)

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.

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

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.

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)

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)

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

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

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.

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

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

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

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

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...

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

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.

Design of a hybrid gas proportional counter with CdTe guard counters for sup 1 sup 4 C dating system

CERN Document Server

Zhang, L; Hinamoto, N; Nakazawa, M; Yoshida, K

2002-01-01

Nowadays uniform, low-cost and large-size compound semiconductor detectors are available up to several square centimeters. We are trying to combine this technology with conventional gas detectors to upgrade an anticoincidence type proportional counter, Oeschger-type thin wall counter of 2.2 l, used for a sup 1 sup 4 C dating facility at the University of Tokyo. In order to increase the ratio of the signal to the background for smaller quantity of samples less than 1 g, an effective approach is to minimize the detector volume at higher gas pressure. However, the anticoincidence function suffers from such a small volume. Therefore we designed a new active wall gas counter of 0.13 l counting volume using CdTe compound semiconductor detectors as the wall of the gas proportional counter to perform anticoincidence. Simulation study showed that at noise thresholds less than 70 keV, the wall counters can reject above 99.8% of events arising from outer gamma rays. Measured noise levels of CdTe detectors were smaller t...

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

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.

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.

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)

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

Countercurrent in high-current microsecond diodes with magnetic insulation

International Nuclear Information System (INIS)

Bugaev, S.P.; Kim, A.A.; Koshelev, V.I.

1979-01-01

In order to increase the efficiency of the generation of tube electron beams in diodes and the efficiency of the electron beam current pulse duration studied is the formation of the electron counter current in microsecond diodes with magnetic insulation in dependence on the various geometry of the cathode joint. The experiments have been carried out at the accelerator with the following parameters: diode voltage from 400 to 600 kV, the front and duration of the pulse 75 ns and 1-2 μs respectively, beam current from 4 to 17 kA, magnetic field of 18 kGs. The current in the drift tube and the total current of the electron gun have been measured. Distributing resistance current of vacuum insulator has been controlled. Conclusions have been made, that, in the case when the diameters of cathode and cathode holder are equal, the electron current is being produced from the reverse side of cathode plasma, which expands across the magnetic field with the rate of (4-5)x10 5 sm/cs. The counter current value has constituted 15% of the total current at the use of reflector with the geometry repeating the shape of the magnetic field force lines, corresponding to the cathode radius. The counter current has not been present at the use of the flat reflector

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

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

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.

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.

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

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.)

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)

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.

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.).

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

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.

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.

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.

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.

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.

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.

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.

''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

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.

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.

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.

The Need for a United Nations Global Counter-Terrorism Coordinator

Directory of Open Access Journals (Sweden)

Howard Stoffer

2013-08-01

Full Text Available The case for a high level United Nations (UN Counter-Terrorism Coordinator position within the UN system has become increasingly urgent in 2013. This need has diluted some Member State reticence to creating a new Assistant Secretary-General position that would supervise and manage the existing counter-terrorism structures in the UN system. A Coordinator would have a basic responsibility to keep track of all of the activities of many formal inter-governmental organisations operating at the international, regional and sub-regional level and would also work closely with national counter-terrorism focal points. In this Policy Brief, Dr. Howard Stoffer reviews the debate among Security Council and Fifth Committee members about the efficacy of establishing a senior UN Global Counter-Terrorism Coordinator. He argues that the creation of such a position could lead to a restructuring of the UN counter-terrorism architecture as well as its funding within the UN budget and among donors. The position would eventually make the UN overall counter-terrorism effort, under the UN Global Counter-Terrorism Strategy, a stronger, more effective and more efficient process with measurable impact on the ground among Member States.

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.

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

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.

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.

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.

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

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...

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.)

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)

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

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

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.)

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

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.)

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.)

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...

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

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.)

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)

Helium-air counter flow in rectangular channels

International Nuclear Information System (INIS)

Fumizawa, Motoo; Tanaka, Gaku; Zhao, Hong; Hishida, Makoto; Shiina, Yasuaki

2004-01-01

This paper deals with numerical analysis of helium-air counter flow in a rectangular channel with an aspect ratio of 10. The channel has a cross sectional area of 5-50 mm and a length of 200 mm. The inclination angle was varied from 0 to 90 degree. The velocity profiles and concentration profiles were analyzed with a computer program [FLUENT]. Following main features of the counter flow are discussed based on the calculated results. (1) Time required for establishing a quasi-steady state counter flow. (2) The relationship between the inclination angle and the flow patterns of the counter flow. (3) The developing process of velocity profiles and concentration profiles. (4) The relationship between the inclination angle of the channel and the velocity profiles of upward flow and the downward flow. (5) The relationship between the concentration profile and the inclination angle. (6) The relationship between the net in-flow rate and the inclination angle. We compared the computed velocity profile and the net in-flow rate with experimental data. A good agreement was obtained between the calculation results and the experimental results. (author)

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.

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.

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.

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.

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

'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)

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.

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.

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.

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...

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.

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.

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.

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.

Description of the manufacture of a Geiger-Muller counter with window

International Nuclear Information System (INIS)

Granados, C. E.

1959-01-01

Total details about the manufacture elements in counter fabrication and the way of obtention are described as well as total indications useful in the installation process and filling of the counter. The appropriate materials and precautions that might be adopted in order to obtain counters with uniform operation and good characteristics, are described. Counters are of brass, with thin mica or aluminium windows and operate at 1100 V approximately with a slope lower than 5 % 1100 V. (Author)

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…

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…

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...

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.

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.

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...

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)

Technical Note: Characterization of a static thermal-gradient CCN counter

Directory of Open Access Journals (Sweden)

G. P. Frank

2007-06-01

Full Text Available The static (parallel-plate thermal-gradient diffusion chamber (SDC was one of the first instruments designed to measure cloud condensation nuclei (CCN concentrations as a function of supersaturation. It has probably also been the most widely used type of CCN counter. This paper describes the detailed experimental characterization of a SDC CCN counter, including calibration with respect to supersaturation and particle number concentration. In addition, we investigated the proposed effect of lowered supersaturation because of water vapor depletion with increasing particle concentration. The results obtained give a better understanding why and in which way it is necessary to calibrate the SDC CCN counter. The calibration method is described in detail and can, in parts, be used for calibrations also for other types of CCN counters.

We conclude the following: 1 it is important to experimentally calibrate SDC CCN counters with respect to supersaturation, and not only base the supersaturation on the theoretical description of the instrument; 2 the number concentration calibration needs to be performed as a function of supersaturation, also for SDC CCN counter using the photographic technique; and 3 we observed no evidence that water vapor depletion lowered the supersaturation.

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

Possibility of semiconductor counters application for internal contamination measurement of whole human body

International Nuclear Information System (INIS)

Cunic, O.; Orlic, M.; Bek-Uzarov, Dj.; Pavlovic, S.; Pavlovic, R.

1997-01-01

The possibility of high resolution semiconductor counters application in 'Vinca' Whole Body Counter for direct beta-gamma internal contamination measurement are discussed, assuming the following relevant characteristics: efficiency, resolution and counter price. A comparison with appropriate characteristics of NaI(Tl) crystal used in 'Vinca' WBC is treated. It is evident that the scintillation counters have the higher detection efficiency, but HPGe counters having much better resolution and recently lowest prices are also acceptable to join the existing NaI(Tl) counters with the HPGe counters in the same time, allow better spectral analyses of the human body activity and additionally more precise estimation of the equivalent doses rate which is generally a essential problem in WBC measurements. (author)

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

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

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...

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.)

Proportional counter with a wire-anode lying on the dielectric surface

International Nuclear Information System (INIS)

Strelkov, A.V.

1983-01-01

Proportional coUnter with wire-anode lying on the dielectric surface is described. The result of the accumulation of charges on the dielectric surface immediately near the wire-anode surface is that such a counter possesses electrostatic memory relative to distribution of the gas amplification coefficient along the anode. SUch a distribution can be received for example by means of irradiation by the neutrons or the γ-rays. The disposition of the wire-anode on the convex dielectric surface allows one to make the ring-shaped counters or the nonplane proportional chambers practically of any profile. However, the energy resolution of the counter with anode on the dielectric is worse than the resolution of counter with free anode particularly at the large gas amplification coefficient

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.

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.

Normative and counter-normative stress messages and symptom reporting: implications for health promotion and a methodological artefact for stress research.

Science.gov (United States)

Ferguson, Eamonn; Lawrence, Claire

2013-05-01

There is increasing use of counter-normative health messages (i.e., evidence-based health information about cause-effect relationships that run counter to shared normative beliefs, e.g., stress can lead to personal growth). The current studies examine the effect of normative and counter-normative messages about stress on levels of symptom reporting. Predictions are derived from reactance, social comparison, and self-enhancement theories. Two studies focus on the development of the messages, and two experimental studies examine the effect of manipulating normative and counter-normative messages on symptom reports. The final study controls for mere-measurement effects and explores the role of stress process variables (appraisals and coping). Exposure to a normative message (stress causes ill health) results in reduced symptom reporting compared to a counter-normative message (stress provides challenge, growth, and development) and control groups. The results suggest that people may use symptom reporting strategically to indicate coping. Based on the argument that beliefs about stress and health are stored as mental models, the theoretical associations derived from stress theory are only observed when a normative message is presented. Counter-normative stress messages may carry no tangible benefits compared to normative messages. Some stress research may suffer from inherent methodological bias when normative information is provided in information and consent sheets. Statement of contribution What is already known on this subject? At present, nothing is known about counter-normative health messages, despite the fact that they are becoming widely used as a public intervention. What does this study add? A clear operational definition of counter-normative messages. A test of three competing theories for counter-normative messages that focus of the stress-symptom link. Demonstrating for the first time, that in the domain of stress and health, counter-normative messages

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

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

Geiger-Mueller haloid counter dead time dependence on counting rate

International Nuclear Information System (INIS)

Onishchenko, A.M.; Tsvetkov, A.A.

1980-01-01

The experimental dependences of the dead time of Geiger counters (SBM-19, SBM-20, SBM-21 and SGM-19) on the loading, are presented. The method of two sources has been used to determine the dead time counters of increased stability. The counters are switched on according to the usually used circuit of discrete counting with loading resistance of 50 MOhm and the separating capacity of 10 pF. Voltage pulses are given to the counting device with the time of resolution of 100 ns, discrimenation threshold 3 V, input resistance 3.6 Ω and the input capacity-15 pF. The time constant of the counter RC-circuit is 50 μs

Construction techniques and working principles of external cathode Geiger-Mueller counters

International Nuclear Information System (INIS)

Sevegnani, Francisco Xavier

1996-01-01

In this paper, the construction technique and working principles of the external cathode Geiger-Mueller counter are described in detail. During the analysis of the behavior of these counters a new phenomena was observed, related to an increase int he background rate with the applied voltage. The experiments have also shown that the pulse amplitude of those counters decreases exponentially with the counting rate. The counters built with the techniques described in this paper has shown plateaus of about 1400 V with slope of 0,8%/100 V. (author)

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.

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)

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...

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.

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

Counter-Stereotypes and Feminism Promote Leadership Aspirations in Highly Identified Women

Science.gov (United States)

Leicht, Carola; Gocłowska, Małgorzata A.; Van Breen, Jolien A.; de Lemus, Soledad; Randsley de Moura, Georgina

2017-01-01

Although women who highly identify with other women are more susceptible to stereotype threat effects, women's identification might associate with greater leadership aspirations contingent on (1) counter-stereotype salience and (2) feminist identification. When gender counter-stereotypes are salient, women's identification should associate with greater leadership aspiration regardless of feminism, while when gender stereotypes are salient, women's identification would predict greater leadership aspirations contingent on a high level of feminist identification. In our study US-based women (N = 208) attended to gender stereotypic (vs. counter-stereotypic) content. We measured identification with women and identification with feminism, and, following the manipulation, leadership aspirations in an imagined work scenario. The interaction between identification with women, identification with feminism, and attention to stereotypes (vs. counter-stereotypes) significantly predicted leadership aspirations. In the counter-stereotypic condition women's identification associated with greater leadership aspirations regardless of feminist identification. In the stereotypic condition women's identification predicted leadership aspirations only at high levels of feminist identification. We conclude that salient counter-stereotypes and a strong identification with feminism may help high women identifiers increase their leadership aspirations. PMID:28626437

Counter-Stereotypes and Feminism Promote Leadership Aspirations in Highly Identified Women.

Science.gov (United States)

Leicht, Carola; Gocłowska, Małgorzata A; Van Breen, Jolien A; de Lemus, Soledad; Randsley de Moura, Georgina

2017-01-01

Although women who highly identify with other women are more susceptible to stereotype threat effects, women's identification might associate with greater leadership aspirations contingent on (1) counter-stereotype salience and (2) feminist identification. When gender counter-stereotypes are salient, women's identification should associate with greater leadership aspiration regardless of feminism, while when gender stereotypes are salient, women's identification would predict greater leadership aspirations contingent on a high level of feminist identification. In our study US-based women ( N = 208) attended to gender stereotypic (vs. counter-stereotypic) content. We measured identification with women and identification with feminism, and, following the manipulation, leadership aspirations in an imagined work scenario. The interaction between identification with women, identification with feminism, and attention to stereotypes (vs. counter-stereotypes) significantly predicted leadership aspirations. In the counter-stereotypic condition women's identification associated with greater leadership aspirations regardless of feminist identification. In the stereotypic condition women's identification predicted leadership aspirations only at high levels of feminist identification. We conclude that salient counter-stereotypes and a strong identification with feminism may help high women identifiers increase their leadership aspirations.

Counter-Stereotypes and Feminism Promote Leadership Aspirations in Highly Identified Women

Directory of Open Access Journals (Sweden)

Carola Leicht

2017-06-01

Full Text Available Although women who highly identify with other women are more susceptible to stereotype threat effects, women's identification might associate with greater leadership aspirations contingent on (1 counter-stereotype salience and (2 feminist identification. When gender counter-stereotypes are salient, women's identification should associate with greater leadership aspiration regardless of feminism, while when gender stereotypes are salient, women's identification would predict greater leadership aspirations contingent on a high level of feminist identification. In our study US-based women (N = 208 attended to gender stereotypic (vs. counter-stereotypic content. We measured identification with women and identification with feminism, and, following the manipulation, leadership aspirations in an imagined work scenario. The interaction between identification with women, identification with feminism, and attention to stereotypes (vs. counter-stereotypes significantly predicted leadership aspirations. In the counter-stereotypic condition women's identification associated with greater leadership aspirations regardless of feminist identification. In the stereotypic condition women's identification predicted leadership aspirations only at high levels of feminist identification. We conclude that salient counter-stereotypes and a strong identification with feminism may help high women identifiers increase their leadership aspirations.

A relativistic self-consistent model for studying enhancement of space charge limited field emission due to counter-streaming ions

International Nuclear Information System (INIS)

Lin, M. C.; Lu, P. S.; Chang, P. C.; Ragan-Kelley, B.; Verboncoeur, J. P.

2014-01-01

Recently, field emission has attracted increasing attention despite the practical limitation that field emitters operate below the Child-Langmuir space charge limit. By introducing counter-streaming ion flow to neutralize the electron charge density, the space charge limited field emission (SCLFE) current can be dramatically enhanced. In this work, we have developed a relativistic self-consistent model for studying the enhancement of SCLFE 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 benchmark or comparison for verification of simulation codes, as well as extension to higher dimensions

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.

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)

Carbon Nanotubes Counter Electrode for Dye-Sensitized Solar Cells Application

Directory of Open Access Journals (Sweden)

Drygała A.

2016-06-01

Full Text Available The influence of the carbon nanotubes counter electrode deposited on the FTO glass substrates on the structure and optoelectrical properties of dye-sensitized solar cells counter electrode (CE was analysed. Carbon materials have been applied in DSSC s in order to produce low-cost solar cells with reasonable efficiency. Platinum is a preferred material for the counter electrode because of its high conductivity and catalytic activity. However, the costs of manufacturing of the platinum counter electrode limit its use to large-scale applications in solar cells. This paper presents the results of examining the structure and properties of the studied layers, defining optical properties of conductive layers and electrical properties of dye-sensitized solar cells manufactured with the use of carbon nanotubes.

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)

Towards a Theory of Fear Management in the Counter-Terrorism Domain

Directory of Open Access Journals (Sweden)

Edwin Bakker

2014-01-01

Full Text Available Since 9/11, the state of the art in counter-terrorism research, counter-terorism measures and counter-terrorism impacts has taken off. Nevertheless, countering terrorism as a branch of fear management is still a discipline to be developed. In this Research Paper, authors Prof. Dr. Edwin Bakker and Prof. Dr. Beatrice de Graaf attempt to lessen this gap. The Paper identifies and analyses governmental approaches to managing fear in relation to terrorist incidents. It is a stocktaking approach, offering a preliminary oversight of some central aspects and pointers on the way forward when constructing and testing such a theory.

Counter-diffusion and -permeation of deuterium and hydrogen through metals

Energy Technology Data Exchange (ETDEWEB)

Kizu, Kaname; Tanabe,; Tetsuo, [Nagoya Univ. (Japan)

1998-03-01

The first experiments for counter-diffusion and -permeation of deuterium and hydrogen through palladium were performed. Deuterium permeation rates against D{sub 2} pressure were measured under the condition where hydrogen permeated to opposite direction by supplying H{sub 2} gas at the permeated side of D{sub 2}. It was found that not a small amount of deuterium was clearly permeated even if the deuterium pressure was much smaller than the hydrogen pressure. Deuterium permeation rate was gradually reduced by increasing the counter H permeation. The deuterium permeation rate under the counter H permeation is well represented by a simple model in which the ratio of the deuterium permeation rates with and without the counter H permeation was proportional to the fractional concentration of deuterium in the bulk. As increasing the hydrogen counter flow, however, the deuterium permeation rate deviates from the model. This means that adsorption (absorption) of D{sub 2} from gas phase is inhibited and surface recombination of deuterium is blocked by hydrogen. (author)

The effect of counter-trading on competition in electricity markets

International Nuclear Information System (INIS)

Dijk, Justin; Willems, Bert

2011-01-01

In a competitive electricity market, nodal pricing is the most efficient way to manage congestion. Counter-trading is inefficient as it gives the wrong long term signals for entry and exit of power plants. However, in a non-competitive market, additional entry will improve the competitiveness of the market, and will increase social benefit by reducing price-cost margins. This paper studies whether the potential pro-competitive entry effects could make counter-trading more efficient than nodal pricing. We find that this is unlikely to be the case, and expect counter-trading to have a negative effect on overall welfare. The potential benefits of additional competition (more competitive prices and lower production cost) do not outweigh the distortions (additional investment cost for the entrant, and socialization of the congestion cost to final consumers). - Research highlights: → 'Counter-trading' and 'nodal pricing' manage congestion in electric grids. → Nodal pricing gives superior locational prices. → Counter-trading induces extra investments in regions with a production surplus. → Extra investments improve competition, but are expected to be socially inefficient.

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.

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

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

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...

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)

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.

Neutron coincidence counter for MOX fuel pins in storage trays: users' manual

International Nuclear Information System (INIS)

Cowder, L.; Menlove, H.

1982-08-01

The neutron coincidence counter for measurement of mixed-oxide fuel pins in storage trays is described. The special detector head has been designed so that the detectors, high-voltage junction boxes, and electronics are interchangeable with those of the high-level neutron coincidence counter system. This manual describes the system components and the operation and maintenance of the counter. The counter was developed at Los Alamos National Laboratory for in-plant inspection applications by the International Atomic Energy Agency

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)

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.

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

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

Prescription Drugs, Over-the-Counter Drugs, Supplements and Herbal Products

Science.gov (United States)

... at risk? Zika virus and pregnancy Folic acid Medicine safety and pregnancy Birth defects prevention Learn how ... the-counter drugs, supplements and herbal products Prescription drugs, over-the-counter drugs, supplements and herbal products ...

distribution of euphausiid crustaceans from the agulhas current

African Journals Online (AJOL)

may set up a northeasterly counter-current close to the coast and cause local upwelling (aowes. 1950; Darbyshire 1964). The Agulhas Current shows considerable seasonal variation in its rate of flow (Darbyshire. 1964) and ...... detailed study of the biology and distribution of this interesting species in eastern Cape coastal.

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)

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.)

A gaseous scintillation counter filled with He3 for neutron spectrometry

International Nuclear Information System (INIS)

Baldin, S.A.; Matveev, V.V.

1962-01-01

The paper describes a gas plant and gaseous scintillation counter, and gives the results of experiments on the recording and spectrometry of neutron beams using a gaseous scintillation counter filled with a mixture of 10% xenene and 90% helium-3 at an overall pressure of 20 ata. Data are given on the design of the gas plant, which makes it possible to operate the counter continuously over long periods of time, as well as providing the required gas mixtures at overall pressures of up to 60 atm and ensuring constant freedom of the gas from contamination. In addition, the paper presents the results of research on the counter's energy resolution and linearity at different energy levels and indicates its efficiency in gamma fields of intensity up to 3 r/h; the possibility of extending the working energy-range of gaseous scintillation counters filled with helium-3 is also considered. (author) [fr

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

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.

A test of planar spark counters at the PEP storage ring

International Nuclear Information System (INIS)

Atwood, W.B.; Bowden, G.B.; Bonneaud, G.R.; Klem, D.E.; Ogawa, A.; Pestov, Yu.N.; Pitthan, R.; Sugahara, R.

1983-01-01

A test of planar spar counters (PSCs) at the PEP electron-positron storage ring showed the following. PSCs can be used under harsh experimental conditions without long term degradation of resolution. On-line time-of-flight resolutions were below 200 ps, coordinate resolutions better than 4 mm, both limited to these values by the resistivity of the semiconducting glass and the electronics used. The best single counter time resolution under realistic conditions at the storage ring was 76 ps. Pulse height was a good indicator of the number of particles striking a counter. Subsequent measurements using cosmis rays gave a single counter time resolution of 50 ps. (orig.)

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.)

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

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

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

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...

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

The study of the influence of helium on the counter's measurement properties

International Nuclear Information System (INIS)

Guan Rui; Weng Kuiping; Ren Xingbi

2009-04-01

In measurement of tritium by the proportional counter, methane is usually used as counter gas. Gas samples have been made with helium and methane in the proportion of concentration and measured to study the influence of helium on the counter's measurement properties. Then gas sample with tritium and helium has been measured, and the result is according with anticipation. The experiment has showed that the plateau curve of counter could be changed by helium, but the influence could be ignored when helium concentration less 10%. (authors)

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.

Interaction between counter-streaming ion-acoustic solitons and the Langmuir waves

International Nuclear Information System (INIS)

Basovich, A.Ya.; Gromov, E.M.; Talanov, V.I.

1984-01-01

The interaction between strong counter-streaming ion-acoustic solitons and the Langmuir waves is considered. At first the Langmuir waves spectrum transformation by counter-streaming ion-acoustic solutions of a preset amplitude e has been found. An increase in the frequency and number of the Langmuir waves due to the Doppler effect in the course of multiple reflection from the f front soliton slope has been determined and the wave number range in which the confinement of the Langmuir waves by counter-streaning solitons is possible has s been found. It is shown that the time of the Langmuir wave transformation into the short-wave region under the effect of the counter-streaming soliton may y be short as compared with the time of the Langmuir wave diffusion into the Landau damping region under the effect of random fields of ion-acoustic waves. In the adiabatic fpproximation changes in the counter-streaming ion acoustic parameters of solitons owing to the Langmuir waves have been

Solidarity and Recognition: Geographies of Counter-globalism

Directory of Open Access Journals (Sweden)

James Goodman

2006-02-01

Full Text Available Globalism is a contested concept, but perhaps best understood as a spatial strategy, which disempowers those unable to transcend the fixity of place and social context. Under globalism fluidity becomes a key source of power, enabling the powerful to liquefy assets, to disembed, and thereby displace, political, social or ecological impacts. The infrastructures of globalism enable the disembodied extension of power across territory, to the extent that one model, universally applicable for all societies, is positioned as supreme. The only possible challenge to globalism perhaps, is through a similarly disembedded counter-movement, that mirrors the global reach and power of mainstream globalism. The praxis of counter-globalist movements suggests a different tendency, one that centres on the assertion of particularity against universality. Expressed in the legitimacy of ‘many worlds’ against ‘one world’ globalism, such resistance centres on exposing the material effects and foregrounding concrete and material experiences of globalism. Movements mobilise against the disembodied logic of globalism on the basis of co-presence and inter-subjectivity, and are embedded in relational concepts of selfhood. They are often intensely embodied and are radically emplaced through militant localism and trans-local dialogue. Counter-globalism thus does not seek to defeat geography; rather it embraces it, as the starting-point of mobilisation. The starting point of this article is thus to analyse globalism as a spatial strategy, a strategy of displacement grounded in material power. Globalism thus signifies the capacity to exploit and dominate at distance, from the sanctity of corporate boardrooms, military briefings and media cutting rooms. The claim is to universal market, military and normative power, but the impact is of extended and deepened division. Centres of power appear more as islands, or enclaves, defined against the backwash effects of counter

Transparent platinum counter electrode for efficient semi-transparent dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Iefanova, Anastasiia; Nepal, Jeevan; Poudel, Prashant; Davoux, Daren; Gautam, Umesh [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Mallam, Venkataiah [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Qiao, Qiquan [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States); Logue, Brian [Chemistry and Biochemistry Department, South Dakota State University, Brookings, SD 57006 (United States); Baroughi, Mahdi Farrokh, E-mail: m.farrokhbaroughi@sdstate.edu [Electrical Engineering and Computer Science Department, South Dakota State University, Brookings, SD 57006 (United States)

2014-07-01

A method for fabrication of highly transparent platinum counter electrodes (CEs) has been developed based on spray coating of Pt nanoparticles (NPs) on hot substrates. This method leads to 86% reduction in Pt consumption reducing the Pt cost per peak watt of counter electrode from $0.79/Wp down to $0.11/Wp compared to the conventional Pt counter electrodes made by sputter deposition. The simplicity and low cost of this method provide a basis for an up-scalable fabrication process. The Pt NP layer is over 88% transparent, leading to overall transparency of 80% when incorporated with indium tin oxide/glass substrates for functional counter electrodes. This counter electrode exhibits a large surface area and high catalytic activity, comparable to that of the conventional opaque CEs. Semi-transparent dye-sensitized solar cells fabricated based on this counter electrode showed 6.17% power conversion efficiency. - Highlights: • Counter electrode (CE) prepared by spraying nanoparticle (NP) Pt on hot substrate. • Low cost and scalable fabrication process of CE. • The spray deposited CE uses 10 times less Pt compared to the sputtering method. • The CE is 80% transparent and exhibits a large surface and high catalytic activity. • A semitransparent dye-sensitized solar cell with Pt NP CE was 6.17% efficient.

Background compensated GM counter for the measurement of low level #betta#-activity

International Nuclear Information System (INIS)

Mori, C.; Kumanomido, H.; Watanabe, T.

1983-01-01

When low level activity of a #betta#-ray source or surface contamination is to be measured with a GM counter, it is desirable to obtain a net count without background count through a single measurement. An end-window GM counter for such a purpose was constructed. The counter has a diaphragm to divide it into two parts. The front part, the window side, can detect #betta#-rays and background radiations, while the rear part only detects background, since #betta#-rays coming through the front are absorbed by the diaphragm. In the counter type I, the sensitive volumes of the two parts are the same and the anode wire of the front is connected to that of the rear through an electric resistor which leads to yielding different pulse heights and rise times. The net count of #betta#-rays can be obtained through a single measurement by subtracting the count in the rear part from that in the front part. In the counter type II, the lengths of the anode wires of the two parts are different, which gives rise to different pulse heights. With a background compensated GM counter, it is possible to shorten the measuring time, keeping nearly the same accuracy compared with a conventional GM counter. (orig.)

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.

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

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

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)

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

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)

Activated graphene nanoplatelets as a counter electrode for dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Gong, Jiawei [Center for Advanced Photovoltaics, Department of Electrical Engineering, South Dakota State University, Brookings, South Dakota 57007 (United States); Department of Mechanical Engineering, North Dakota State University, Fargo, North Dakota 58102 (United States); Zhou, Zhengping; Qiao, Qiquan, E-mail: qiquan.qiao@sdstate.edu [Center for Advanced Photovoltaics, Department of Electrical Engineering, South Dakota State University, Brookings, South Dakota 57007 (United States); Sumathy, K. [Department of Mechanical Engineering, North Dakota State University, Fargo, North Dakota 58102 (United States); Yang, Huojun [Department of Construction Management and Engineering, North Dakota State University, Fargo, North Dakota 58102 (United States)

2016-04-07

Activated graphene nanoplatelets (aGNPs) prepared by a hydrothermal method using KOH as activating agent were used as counter electrode for high efficiency dye-sensitized solar cells (DSSCs). After the KOH activation, the scanning electron microscopy image shows that aGNPs demonstrate a more curled, rough, and porous morphology which could contain both micro- and mesopores. The KOH activation changed the stacked layers of GNPs to a more crumpled and curved morphology. The microstructure of large pores significantly increased the electrode surface area and roughness, leading to the high electrocatalytic activity for triiodide reduction at the counter electrode. The DSSCs fabricated using aGNP as counter electrodes were tested under standard AM 1.5 illumination with an intensity of 91.5 mW/cm{sup 2}. The device achieved an overall power conversion efficiency of 7.7%, which is comparable to the conventional platinum counter electrode (8%). Therefore, the low cost and high performance aGNP based counter electrode is a promising alternative to conventional Pt counter electrode in DSSCs.

Design of an extended range long counter using super Monte Carlo simulation

International Nuclear Information System (INIS)

Mazunga, Mohamed; Li, Taosheng; Li, Yanan; Hong, Bing; Wang, Yongfeng; Ji, Xiang

2017-01-01

We have designed an extended range neutron long counter on the basis of work optimized using SuperMC code. The problem of the existing traditional long counters is that their response function falls rapidly above 5 MeV. We proposed a new designed by adding two layers of converter material inside the polyethylene moderator. The relatively low density chromium and high density lead metals convert high energy neutron by (n, xn) spallation reaction. This produces more neutrons of lower energies, which have higher probability of being detected by thermal 3 He-counter. The response function at lower neutron energies was improved by inserting small polyethylene cylinder in front of 3 He counter. In this design we achieved to extent the flat response function of the long counter from few keV up to 150 MeV. The total fluctuation of response curve is less than ±9% over the entire energy range. The designed long counter is suitable to be used as neutron monitor for monitoring neutron fluence at high-energy neutron source. (authors)

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...

78 FR 57623 - TRICARE Over-the-Counter Drug Demonstration Project

Science.gov (United States)

2013-09-19

... B One-Step (levonorgestrel) emergency contraceptive as an over-the-counter product ``for all women...-Counter Plan B One-Step Emergency Contraceptive (levonorgestrel). (2) OTC availability of Plan B One-Step Emergency Contraceptive (levonorgestrel) through the demonstration project will be at retail dispensing...

Replacement between conformity and counter-conformity in consumption decisions.

Science.gov (United States)

Chou, Ting-Jui; Chang, En-Chung; Dai, Qi; Wong, Veronica

2013-02-01

This study assessed, in a Chinese context, how self-esteem interacts with perceived similarity and uniqueness to yield cognitive dissonance, and whether the dissonance leads to self-reported conformity or counter-conformity behavior. Participants were 408 respondents from 4 major Chinese cities (M age = 33.0 yr., SD = 4.3; 48% men). Self-perceptions of uniqueness, similarity, cognitive dissonance, self-esteem and need to behave in conformity or counter-conformity were measured. A theoretical model was assessed in four situations, relating the ratings of self-esteem and perceived similarity/uniqueness to the way other people at a wedding were dressed, and the resultant cognitive dissonance and conformity/ counter-conformity behavior. Regardless of high or low self-esteem, all participants reported cognitive dissonance when they were told that they were dressed extremely similarly to or extremely differently from the other people attending the wedding. However, the conforming/counter-conforming strategies used by participants to resolve the cognitive dissonance differed. When encountering dissonance induced by the perceived extreme uniqueness of dress, participants with low self-esteem tended to say they would dress next time so as to conform with the way others were dressed, while those with high self-esteem indicated they would continue their counter-conformity in attire. When encountering dissonance induced by the perceived extreme similarity to others, both those with high and low self-esteem tended to say they would dress in an unorthodox manner to surprise other people in the future.

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)

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.

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.

Risetime discrimination applied to pressurized Xe gas proportional counter for hard x-ray detection

International Nuclear Information System (INIS)

Fujii, Masami; Doi, Kosei

1978-01-01

A high pressure Xe proportional counter has been developed for hard X-ray observation. This counter has better energy-resolving power than a NaI scintillation counter, and the realization of large area is relatively easy. This counter is constructed with a cylindrical aluminum tube, and this tube can be used at 40 atmospheric pressure. The detection efficiency curves were obtained in relation to gas pressure. It is necessary to reduce impurities in the Xe gas to increase the energy-resolving power of the counter. The increase of gas pressure made the resolving power worse. The characteristics of the counter were stable for at least a few months. The wave form discrimination was applied to reduce the background signals such as pulses caused by charged particles and gamma-ray. This method has been used for normal pressure counter, and in the present study, it was applied for the high pressure counter. It was found that the discrimination method was able to be applied to this case. (Kato, T.)

Analysis of Thermal Stability of Different Counter on 28nm FPGA

DEFF Research Database (Denmark)

Gupta, Daizy; Yadav, Amit; Hussain, Dil muhammed Akbar

2016-01-01

In this paper we are presenting the power analysis for thermal awareness of different counters. The technique we are using to do the analysis is based on 28 nm FPGA tech-nique. In this work during implementation on FPGA, we are going to analyze thermal stability of different counters in temperatu...... range of 10oC, 30oC, 60oC, 90oC, 120oC. There is 90.36% reduction in leakage power of divide by 2 counter when we scale down the temperature from 120oC to 10oC and 49.61% reduction in leakage power of LFSR up counter when we scale down the temperature from 120oC to 10oC....

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...

Ionic magnetic fluids in polar solvents with tuned counter-ions

Energy Technology Data Exchange (ETDEWEB)

Lopes Filomeno, C. [Sorbonne Universités, UPMC Univ Paris 06, CNRS, Lab. PHENIX, Paris (France); Grupo de Fluidos Complexos Inst. de Quimica, Univ. de Brasília, Brasília (DF) (Brazil); Kouyaté, M. [Sorbonne Universités, UPMC Univ Paris 06, CNRS, Lab. PHENIX, Paris (France); Cousin, F. [Lab. Léon Brillouin – CE-Saclay, Gif-sur-Yvette (France); Demouchy, G. [Sorbonne Universités, UPMC Univ Paris 06, CNRS, Lab. PHENIX, Paris (France); Dpt de physique, Univ. de Cergy Pontoise, Cergy-Pontoise (France); Dubois, E.; Michot, L.; Mériguet, G. [Sorbonne Universités, UPMC Univ Paris 06, CNRS, Lab. PHENIX, Paris (France); Perzynski, R., E-mail: regine.perzynski@upmc.fr [Sorbonne Universités, UPMC Univ Paris 06, CNRS, Lab. PHENIX, Paris (France); Peyre, V.; Sirieix-Plénet, J. [Sorbonne Universités, UPMC Univ Paris 06, CNRS, Lab. PHENIX, Paris (France); Tourinho, F.A. [Grupo de Fluidos Complexos Inst. de Quimica, Univ. de Brasília, Brasília (DF) (Brazil)

2017-06-01

The aim of the present study is to propose a new reproducible method for preparing colloidal dispersions of electrostatically charged nanoparticles (NPs) in polar solvents with different kinds of counter-ions. Maghemite NPs are here dispersed in solvents of different dielectric constant, namely water, dimethylsulfoxide (DMSO) and an ionic liquid, ethylammonium nitrate (EAN). If the existence of a NP superficial charge happens to be necessary for the colloidal stability of the dispersions in these three solvents, the standard DLVO theory cannot be used any more to describe the colloidal stability in EAN. The structure of the dispersions and the strength of the interparticle repulsion are investigated by small angle X-ray scattering measurements, in association with Ludwig–Soret coefficient determinations. Specificities, associated to the nature of the counter-ions are identified in this work on the colloidal stability, on the interparticle repulsion and on the Ludwig–Soret coefficient. - Highlights: • A controlled synthesis of ionic magnetic fluids in three polar solvents is proposed. • Colloidal repulsion in the magnetic fluids depends on the counter-ion nature. • Soret coefficient of citrate-coated maghemite nanoparticles is probed in water-pH7. • Thermophilicity of nanoparticles depends on the nature of their counter-ions. • Nanoparticles dressed with same counter-ions have solvent-dependent thermoproperties.

Construction techniques and operation principles of Geiger-Mueller counters using external cathode (Mazetype)

International Nuclear Information System (INIS)

Sevegnani, F.X.

1988-01-01

The construction techniques for external cathode (Maze) and internal cathode Geiger-Muller counters are described, showing the operation principles and the used material nature. More than 200 counter types were evaluated analysing their characteristics. The influence of several types of guard-rings was studied, for optimizing counter operation conditions. Plateaus of the order of 700 V with slope of 0,3%/100 V for the net counting rate, and 1400 V with a slope of 0,8/100 V for total counts using total pressure of 10 cmHg, were obtained. A counter for β detection, using blown glass window in one of the edges of the cylinder was constructed. Counters of long life using materials such as, mica, adhesive glues, etc., were obtained. The results shown that the best counter operation occurs when it is empty in a vacuum of 10 -5 mmHg. (M.C.K.) [pt

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)

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

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

35 years of existence of a whole-body counter in the Czech Republic - experience and prospects

International Nuclear Information System (INIS)

Malatova, I.; Foltanova, S.; 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

On the Performance of Counter-Based Broadcast Scheme for Mobile ...

African Journals Online (AJOL)

Despite its simplicity, it can result in high redundant retransmission, contention and collision, a phenomenon collectively referred to as the broadcast storm problem. Counter-based broadcast scheme has been proposed to mitigate this inherent problem and it relies on counter threshold value for rebroadcast decision. Thus ...

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.

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)

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.

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.

Alternative modes for optical trapping and manipulation using counter-propagating shaped beams

International Nuclear Information System (INIS)

Palima, D; Tauro, S; Glückstad, J; Lindballe, T B; Kristensen, M V; Stapelfeldt, H; Keiding, S R

2011-01-01

Counter-propagating beams have enabled the first stable three-dimensional optical trapping of microparticles and this procedure has been enhanced and developed over the years to achieve independent and interactive manipulation of multiple particles. In this work, we analyse counter-propagating shaped-beam traps that depart from the conventional geometry based on symmetric, coaxial counter-propagating beams. We show that projecting shaped beams with separation distances previously considered axially unstable can, in fact, enhance the axial and transverse trapping stiffnesses. We also show that deviating from using perfectly counter-propagating beams to use oblique beams can improve the axial stability of the traps and improve the axial trapping stiffness. These alternative geometries can be particularly useful for handling larger particles. These results hint at a rich potential for light shaping for optical trapping and manipulation using patterned counter-propagating beams, which still remains to be fully tapped

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

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

Suppression and utilization of spurious pulse occurence in organic GM-counters

International Nuclear Information System (INIS)

Narita, Y.; Igarashi, R.; Akagami, H.; Ozawa, Y.

1979-01-01

The authors have made a study of suppression and utilization of spurious pulse occurrence in organic GM-counters. Almost all spurious pulses in the organic GM-counter are the delayed pulses which occur being dependent upon the radiation intensity. The occurrence rate of the delayed pulses against the radiation intensity is affected by the intensity of the electric field in the vicinity of the cathode of the GM-counter. The occurrence of the delayed pulses can be suppressed when the electric field in the vicinity of the cathode is kept at high value. On the contrary, the occurrence of the delayed pulses can be utilized for the dosimetry of the pulsed radiation by means of increasing the space of the weak electric field in the GM-counter. (Auth.)

Using Counter-Stories to Challenge Stock Stories about Traveller Families

Science.gov (United States)

D'Arcy, Kate

2017-01-01

Critical Race Theory (CRT) is formed from a series of different methodological tools to expose and address racism and discrimination. Counter-stories are one of these tools. This article considers the potential of counter-stories as a methodological, theoretical and practical tool to analyse existing educational inequalities for Traveller…

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

'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

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...

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)

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.

Silica aerogel Cherenkov counter for the KEK B-factory experiment

CERN Document Server

Sumiyoshi, T; Enomoto, R; Iijima, T; Suda, R; Leonidopoulos, C; Marlow, D R; Prebys, E; Kawabata, R; Kawai, H; Ooba, T; Nanao, M; Suzuki, K; Ogawa, S; Murakami, A; Khan, M H R

1999-01-01

Low-refractive-index silica aerogel is a convenient radiator for threshold-type Cherenkov counters, which are used for particle identification in high-energy physics experiments. For the BELLE detector at the KEK B-Factory we have produced about 2 m sup 3 of hydrophobic silica aerogels of n=1.01-1.03 using a new production method. The particle identification capability of the aerogel Cherenkov counters was tested and 3 sigma pion/proton separation has been achieved at 3.5 GeV/c. Radiation hardness of the aerogels was confirmed up to 9.8 Mrad. The Aerogel Cherenkov counter system (ACC) was successfully installed in the BELLE just before this conference.

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.

Hardware enabled performance counters with support for operating system context switching

Science.gov (United States)

Salapura, Valentina; Wisniewski, Robert W.

2015-06-30

A device for supporting hardware enabled performance counters with support for context switching include a plurality of performance counters operable to collect information associated with one or more computer system related activities, a first register operable to store a memory address, a second register operable to store a mode indication, and a state machine operable to read the second register and cause the plurality of performance counters to copy the information to memory area indicated by the memory address based on the mode indication.

Counter-Stereotypes and Images: An Exploratory Research and Some Questions

Science.gov (United States)

Morin-Messabel, Christine; Ferrière, Séverine; Martinez, Frederic; Devif, Julie; Reeb, Laurence

2017-01-01

The dynamics of the construction and perpetuation of gender stereotypes are classic research subjects in social psychology and in the field of educational guidelines in France. The most recent government decree aims to counter stereotypes in schools, by exposing pupils to counter-stereotypes. This study examines the effects of activating…

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

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.

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

Analytical Solution for the Anisotropic Rabi Model: Effects of Counter-Rotating Terms

Science.gov (United States)

Zhang, Guofeng; Zhu, Hanjie

2015-03-01

The anisotropic Rabi model, which was proposed recently, differs from the original Rabi model: the rotating and counter-rotating terms are governed by two different coupling constants. This feature allows us to vary the counter-rotating interaction independently and explore the effects of it on some quantum properties. In this paper, we eliminate the counter-rotating terms approximately and obtain the analytical energy spectrums and wavefunctions. These analytical results agree well with the numerical calculations in a wide range of the parameters including the ultrastrong coupling regime. In the weak counter-rotating coupling limit we find out that the counter-rotating terms can be considered as the shifts to the parameters of the Jaynes-Cummings model. This modification shows the validness of the rotating-wave approximation on the assumption of near-resonance and relatively weak coupling. Moreover, the analytical expressions of several physics quantities are also derived, and the results show the break-down of the U(1)-symmetry and the deviation from the Jaynes-Cummings model.

Application of a background-compensated Geiger-Mueller counter to a survey meter

International Nuclear Information System (INIS)

Mori, C.; Kumanomido, H.; Watanabe, T.

1984-01-01

A background-compensated Geiger-Mueller counter was used as a probe for a GM survey meter to obtain a net count rate of β-rays from a radioactive source in a quick survey. Although a background counting ratio between the two parts in the counter, front and rear, varied somewhat depending on the incident direction of background γ-rays, it was possible to compensate the background counts by subtracting a part of the rear counts, which were background counts, from the front counts, which contained β-ray counts and background counts. Undesirable small pulses generated during the recovering time after a full Geiger discharge were eliminated by an anticoincidence gating method. The survey meter with this counter and a differential ratemeter is useful for obtaining a net count rate of β-rays emitted from a surface radioactive-contamination or from a source being put near the window of the counter with nearly the same accuracy in half the measuring time as compared with conventional GM counters. (orig.)

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…

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)

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

Physical properties of the TOF (time of flight) scintillation counters of DELPHI

International Nuclear Information System (INIS)

Benlloch, J.M.; Castillo, M.V.; Ferrer, A.; Fuster, J.; Higon, E.; Llopis, A.; Salt, J.; Sanchez, E.; Sanchis, E.; Silvestre, E.; Cuevas, J.

1990-01-01

In this paper we report the physical properties of the time of flight (TOF) scintillator counters used for the DELPHI Experiment at CERN. We discuss the different choices studied for the wrapping of the counters in order to obtain best efficiencies for light transmission. A very good agreement of the performances of the counters has been found with the results of an original Monte Carlo program. The main characteristics of the TOF counters of DELPHI are: an effective light attenuation length of 135 cm, effective light speed of 15.91 cm/ns, a time resolution of 1.2 ns, and an efficiency for detection of minimum ionizing particles of 99.9%. (orig.)

Using Delphi to realize the function of the γ-immuno counter

International Nuclear Information System (INIS)

Qi Na; Chu Yan; He Wenhua

2005-01-01

This paper introduces the concept of Radioimmunoassay and the background of the γ-immuno counter, summarizes the feature of the Delphi and discusses the superiority of using language of Delphi to realize the function of γ-immuno counter. (authors)

Multicultural Young Adult Literature as a Form of Counter-Storytelling

Science.gov (United States)

Hughes-Hassell, Sandra

2013-01-01

Counter-storytelling is defined by critical race theory scholars as a method of telling the stories of those people whose experiences are not often told, including people of color, the poor, and members of the LGBTQ community. This article discusses multicultural young adult literature as a form of counter-storytelling, with an emphasis on how…

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

Real-time aerosol photometer and optical particle counter comparison

International Nuclear Information System (INIS)

Santi, E.; Belosi, F.; Santachiara, G.; Prodi, F.; Berico, M.

2010-01-01

The paper presents the results of a comparison exercise among real-time aerosol samplers, based on different light scattering techniques. The comparison was carried out near to the ISAC institute in a box positioned inside the CNR research area in Bologna. Two nephelometers (Dust Trak from TSI, and Air Genius from Unitec) and an optical particle counter (ENVIRO-check from Grimm) were used for P M1 and P M10 fraction assessment. In the case of the optical particle counter, the particle number concentration in each size bin was also used. In parallel, two manual sampling lines were employed for reference (gravimetric) measurements. The results highlight different factor scales for the dust monitors, in comparison with gravimetric assessment, underlining the importance of a user calibration of such monitors as a function of the specific aerosol sampled. Moreover, the relative fluctuations of the hourly P M 10 and P M1 concentrations, against daily average concentrations, were studied in order to compare the ability of each sampler to follow changes in the aerosol size distribution. It was found that the photometers and optical particle counter revealed different behaviours. In the latter, a small increase in the particle concentration number in the coarse fraction gave a relatively high increase in the mass concentration that was not measured by the photometers. The explanation could be the relatively slight influence of a small particle number variation on the total scattered light for the photometers, unlike the case of the optical particle counter, where each particle contributes to the mass concentration. This aspect merits future research in order to better understand optical particle counter output used in P Mx monitoring activities.

Analytical Solution for the Anisotropic Rabi Model: Effects of Counter-Rotating Terms

OpenAIRE

Zhang, Guofeng; Zhu, Hanjie

2015-01-01

The anisotropic Rabi model, which was proposed recently, differs from the original Rabi model: the rotating and counter-rotating terms are governed by two different coupling constants. This feature allows us to vary the counter-rotating interaction independently and explore the effects of it on some quantum properties. In this paper, we eliminate the counter-rotating terms approximately and obtain the analytical energy spectrums and wavefunctions. These analytical results agree well with the ...

Characteristics of proportional counters used in X-ray radiometric analysis

International Nuclear Information System (INIS)

Mamikonyan, S.V.; Martishchenko, L.G.; Mel'ttser, L.V.

1972-01-01

Counters with extended (up to 10 cm 2 ) apertres have been described and the results obtained are presented. CPM-15 and CPM-16 counters are intended for sensoring and spectral analysis of X-rays in the range of 2.5 to 23 and 2.5 to 15 keV, respectively. The only difference is in the gas composition. The CPM-15 counter is filled with 90 per cent xenon plus 10 per cent methane used as a quenching dopant. The CPM-16 is filled with 90 per cent argon and 10 per cent methane. The life time is 10 10 pulses at 1800 V for CPM-16 and at 2200 V for CPM-15

A Survey of Teenagers' Attitudes Toward Moving Oral Contraceptives Over the Counter.

Science.gov (United States)

Manski, Ruth; Kottke, Melissa

2015-09-01

Evidence suggests that over-the-counter access to oral contraceptives may help expand use among adult women. Teenagers may particularly benefit from this approach, as they experience disproportionately high rates of unintended pregnancy and face unique challenges accessing contraceptives. However, limited research has explored teenagers' attitudes toward over-the-counter access. In 2014, a sample of 348 females aged 14-17, recruited via Facebook advertisements, participated in an online survey assessing teenagers' attitudes toward over-the-counter access and their understanding of how to use oral contraceptives after reading a prototype over-the-counter product label. Differences by participants' characteristics were assessed in bivariate analyses (Pearson chi-square and Fisher's exact tests for categorical measures, and independent t tests and one-way analyses of variance for continuous measures). Seventy-three percent of participants supported over-the-counter access, and 61% reported that they would likely use oral contraceptives available through this approach. Few subgroup differences were found. Notably, sexually experienced participants were significantly more likely than others both to support this approach (85% vs. 63%) and to be interested in obtaining oral contraceptives this way (77% vs. 48%). Participants understood an average of 7.1 of eight key concepts that the prototype product label was intended to convey; no significant differences were found among subgroups. Over-the-counter access may be a promising approach for providing oral contraceptives to teenagers. Additional research is needed to evaluate whether teenagers can screen themselves for contraindications to oral contraceptive use and correctly use oral contraceptives obtained over the counter. Copyright © 2015 by the Guttmacher Institute.

Advanced computer-controlled automatic alpha-beta air sample counter

International Nuclear Information System (INIS)

Howell, W.P.; Bruinekool, D.J.; Stapleton, E.E.

1983-01-01

An improved computer controlled automatic alpha-beta air sample counter was developed, based upon an earlier automatic air sample counter design. The system consists of an automatic sample changer, an electronic counting system utilizing a large silicon diode detector, a small desk-type microcomputer, a high speed matrix printer, and the necessary data interfaces. The system is operated by commands from the keyboard and programs stored on magnetic tape cassettes. The programs provide for background counting, Chi 2 test, radon subtraction, and sample counting for sample periods of one day to one week. Output data are printed by the matrix printer on standard multifold paper. The data output includes gross beta, gross alpha, and plutonium results. Data are automatically corrected for background, counter efficiency, and in the gross alpha and plutonium channels, for the presence of radon

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...

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).

Development of a position-sensitive fission counter and measurement of neutron flux distributions

International Nuclear Information System (INIS)

Yamagishi, Hideshi; Soyama, Kazuhiko; Kakuta, Tsunemi

2001-08-01

A position-sensitive fission counter (PSFC) that operates in high neutron flux and high gamma-ray background such as at the side of a power reactor vessel has been developed. Neutron detection using the PSFC with a solenoid electrode is based on a delay-line method. The PSFC that has the outer diameter of 25 mm and the sensitive length of 1000 mm was manufactured for investigation of the performances. The PSFC provided output current pulses that were sufficiently higher than the alpha noise, though the PSFC has a solenoid electrode and large electrode-capacitance. The S/N ratio of PSFC outputs proved to be higher than that of ordinary fission counters with 200 mm sensitive length. A performance test to measure neutron flux distributions by a neutron measuring system with the PSFC was carried out by the side of a graphite pile, W2.4 x H1.4 x L1.2 m, with neutron sources, Am-Be 370 GBq x 2. It was confirmed that the neutron flux distribution was well measured with the system. (author)

Tobacco counter-advertising: a review of the literature and a conceptual model for understanding effects.

Science.gov (United States)

Agostinelli, Gina; Grube, Joel W

2003-01-01

The tobacco counter-advertising literature is reviewed as it relates to basic process questions concerning what makes counter-advertisements effective. Limitations in addressing (a) counter-advertisement content and the psychological mediators targeted, (b) counter-advertisement style and the affective reactions targeted, (c) prior smoking experience, and (d) other audience factors are enumerated. A theoretical model based on alcohol advertising research is presented to address those limitations. The model addresses the practical research question of predicting when tobacco counter-advertising will work by examining the independent influence of each of these enumerated factors, as well as how these factors operate in concert, qualifying each other. The model also addresses the process question of explaining how counter-advertising works by identifying affective and cognitive processes as mediators. By understanding the processes that underlie the qualified findings, one can better advise the designers of tobacco counter-advertisements how to be more effective.

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...

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.

NiO-NF/MWCNT nanocomposite catalyst as a counter electrode for high performance dye-sensitized solar cells

Science.gov (United States)

Raissan Al-bahrani, Majid; Liu, Linfeng; Ahmad, Waqar; Tao, Jiayou; Tu, Fanfan; Cheng, Ze; Gao, Yihua

2015-03-01

In this paper, we fabricated nickel oxide nanofilament/multiwall carbon nanotubes (NiO-NF/MWCNT) nanocomposite by a simple hydrothermal synthesis method as a counter- electrode (CE) in a dye-sensitized solar cell (DSSC). Transmission electron microscopy, scanning electron microscopy images and X-ray diffraction analysis clearly indicated the formation of NiO-NF/MWCNT nanocomposite. The electro-chemical properties of NiO-NF/MWCNT CE are studied by cyclic voltammetry and electrochemical impedance spectroscopy. In particular, current-voltage measurements indicated superior power conversion efficiency (PCE) of 7.63% of the NiO-NF/MWCNT CE compared to 6.72% for the platinum (Pt). The superior photovoltaic performance and low cost of the NiO-NF/MWCNT nanocomposite can be potentially exploited as a new counter-electrode in DSSCs.

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)

A Fear Management Approach to Counter-Terrorism

Directory of Open Access Journals (Sweden)

Tinka Veldhuis

2012-02-01

Full Text Available Spreading fear is the essence of terrorism. Terrorists exploit fear by terrorising the target audience into concessions. Understanding how feelings of fear influence the way people feel, think and act is therefore an important starting point to explore how individuals and societies can learn how to cope with fear of terrorism. In this Policy Brief, Research Fellows Prof. Dr. Edwin Bakker and Dr. Tinka Veldhuis explore the dynamics of fear in response to terrorism, and emphasise the importance of integrating initiatives to manage fear of terrorism and reduce its negative consequences into overarching counter-terrorism strategies. It argues that societies can benefit greatly from promoting resilience and a fear management approach to counter-terrorism.

Visualization study of helium-air counter flow through a small opening

International Nuclear Information System (INIS)

Fumizawa, Motoo

2007-01-01

Buoyancy-driven counter flows of helium-air were investigated through horizontal and inclined small openings. Counter flows may occur following a window opening as ventilation, fire in the room as well as a pipe rupture accident in a high temperature gas-cooled nuclear reactor. The experiment has carried out by a test chamber filled with helium and flow was visualized by the smoke wire method. The flow behavior has recorded by a high-speed camera with a computer system. The image of the flow was transferred to the digital data, thus the flow velocity was measured by PTV software. The mass fraction in the test chamber was measured by electronic balance. The detected data was arranged by the densimetric Floude number of the counter flow rate that derived from the dimensional analysis. The method of mass increment was developed and applied to measure the counter flow rate. By removing the cover plate placed on the top of the opening, the counter flow initiated. Air enters the test chamber and the mass of the gas mixture in the test chamber increased. The volumetric counter flow rate was evaluated from the mass increment data. In the case of inclination openings, the results of both methods were compared. The inclination angle for maximum densimetric Floude number decreased with increasing length-to-diameter ratio of the opening. For a horizontal opening, the results from the method of mass increment agreed with those obtained by other authors for a water-brine system. (author)

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...

The background of external γ radiation in the proportional counters in SAGE experiment

International Nuclear Information System (INIS)

Gavrin, V.N.; Gorbachev, V.V.

2003-01-01

The influence of external γ radiation on the process of 71 Ge-decay counting in proportional counters in SAGE experiment of solar neutrino flux measurement is examined. One determines the systematic error of SAGE result, connected with radon decays inside the air volume surrounding the counters, and the background counting rate of proportional counters from γ radiation of passive and active shield [ru

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.

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)

VOICES AGAINST EXTREMISM: A CASE STUDY OF A COMMUNITY-BASED CVE COUNTER-NARRATIVE CAMPAIGN

Directory of Open Access Journals (Sweden)

Logan Macnair

2017-03-01

Full Text Available This article presents a case study of the recently conceived and ongoing counter-extremism campaign, Voices Against Extremism, a campaign designed and implemented by university students from Vancouver, Canada. Through a multifaceted approach that includes extensive use of social media, academic research, and grassroots community activities and involvement, Voices Against Extremism operates under the mission statement of countering and preventing violent extremism and radicalization through the humanization of minority groups and through the education and engagement of the silent majority. This article examines the effectiveness of this campaign as a proactive counter-radicalization strategy by outlining its specific components and activities. Based on the results of this campaign, suggestions are then offered regarding specific counter-extremism and counter-radicalizations policies that may be adopted by law enforcement, policymakers – or any other organizations concerned with countering and preventing radicalization and violent extremism – with a specific focus on the potential benefits of proactive and long-term social and community engagement.

CCM-R: Secure Counter Synchronization for IoT Wireless Link

DEFF Research Database (Denmark)

Roy, Upal; Yin, Jiachen; Andersen, Birger

2016-01-01

In this paper we propose and evaluate a new version of the CCM mode of operation, CCM-R, which isan extended and alternate version of the original CBC-MAC with Counter Mode(CCM) that was created to address the problem of counter synchronization. While CCM is considered secure when used/implemente...... it suitable for low-power wireless IoT devices....

Radiation thickness gauge using beta particle sensitivity controlled open air corona streamer counter

International Nuclear Information System (INIS)

Fouad, L.; El-Hazek, S.; El-Araby, S.

1999-01-01

Beta particles have been used extensively in radio gauging applications when measurements of foil thicknesses are desired. Using beta particle open air corona streamer counter (point-grid-plane) as a thickness gauge is presented. This gauge consists of two similar counters with two similar Sr-90 beta sources. One counter-source combination is called standard unit, and the other counter-source combination is called measuring unit in which the required foil thickness can be measured by inserting it between the source and the counter. The signals from the counters are amplified with the same gain factor and the net difference between their responses is measured using specially designed electronic circuit. By this way any change that takes place in the operating medium (variation of parameters of open air i.e. temperature, humidity...etc) can similarly affect the two units, the errors in the measurements caused by them are cancelled, and the only response is due to the measured foil thickness. A theoretical model is suggested to explain and analyze the overall response of the gauge system and calculate the calibration thickness gauge constant. All theoretical findings are confirmed by experiments

Position-sensitive proportional counters using resistance-capacitance position encoding

International Nuclear Information System (INIS)

Kopp, M.K.; Borkowski, C.J.

1975-12-01

A new method was developed for encoding the position of individual photons, neutrons, or charged particles in proportional counters by using the distributed RC line characteristics of these counters. The signal processing is described and guidelines for the design and operation of these position sensitive proportional counters (PSPCs) are given. Using these guidelines, several prototypic PSPCs were constructed to improve the spatial resolution and shorten the signal processing time; for example, the intrinsic spatial uncertainty was reduced to 28 μ fwhm for alpha particles and 100 μ fwhm for low-energy x rays (2 to 6 keV). Also, the signal processing time was reduced to 0.6 μsec without seriously degrading the spatial resolution. These results have opened new fields of application of the RC position encoding method in imaging distributions of photons, charged particles, or neutrons in nuclear medicine, physics, and radiography

Development of a lithium fluoride zinc sulfide based neutron multiplicity counter

Science.gov (United States)

Cowles, Christian; Behling, Spencer; Baldez, Phoenix; Folsom, Micah; Kouzes, Richard; Kukharev, Vladislav; Lintereur, Azaree; Robinson, Sean; Siciliano, Edward; Stave, Sean; Valdez, Patrick

2018-04-01

The feasibility of a full-scale lithium fluoride zinc sulfide (LiF/ZnS) based neutron multiplicity counter has been demonstrated. The counter was constructed of modular neutron detecting stacks that each contain five sheets of LiF/ZnS interleaved between six sheets of wavelength shifting plastic with a photomultiplier tube on each end. Twelve such detector stacks were placed around a sample chamber in a square arrangement with lithiated high-density polyethylene blocks in the corners to reflect high-energy neutrons and capture low-energy neutrons. The final system design was optimized via modeling and small-scale test. Measuring neutrons from a 252Cf source, the counter achieved a 36% neutron detection efficiency (ɛ) and an 11 . 7 μs neutron die-away time (τ) for a doubles figure-of-merit (ɛ2 / τ) of 109. This is the highest doubles figure-of-merit measured to-date for a 3He-free neutron multiplicity counter.

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)

Counter-Storytelling with African Proverbs: A Vehicle for Teaching Social Justice and Global Understanding in Urban, U.S. Schools

Science.gov (United States)

Asimeng-Boahene, Lewis

2010-01-01

Although the current demographics of urban schools in the United States reflect a rapid growth of culturally and linguistically diverse students, curricula continue to emphasize mainstream culture; cultural and linguistic experiences of these diverse students are ignored. In this article, the author examines how the use of counter storytelling in…

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…

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.

The cognitive costs of the counter-stereotypic: gender, emotion, and social presence.

Science.gov (United States)

McCarty, Megan K; Kelly, Janice R; Williams, Kipling D

2014-01-01

We explored the concurrent and subsequent cognitive consequences of the experience of gender counter-stereotypic emotions. Participants experiencing gender counter-stereotypic emotions were expected to display less emotional expression and demonstrate poorer cognitive performance when in the public condition than when in the private condition. Seventy-one women and 66 men completed an anger- or sadness-inducing task privately or publicly. Participants completed two cognitive tasks: one during and one after the emotion-induction task. Participants exhibited poorer performance during and following gender counter-stereotypic emotions only in the public condition. Direct evidence for greater suppression of gender counter-stereotypic emotions in the public conditions was not obtained. These results suggest that the same public emotional events may be differentially cognitively depleting depending on one's gender, potentially contributing to the perpetuation of stereotypes.

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

The Tax Evasion in Ukraine: Causes and Methods of Countering

Directory of Open Access Journals (Sweden)

Parfentii Liudmyla A.

2018-03-01

Full Text Available The essence of the concept of tax evasion is researched; reasons of occurrence and development of this phenomenon are analyzed; proposals on the main directions of prevention and countering tax evasion have been developed. Analyzing, systematizing and generalizing the scientific works of many scholars, it was found that there is no unified approach to interpretation of the essence of this phenomenon in the context of legality and awareness of relevant actions in the scientific literature. As a result of the research the factors of tax evasion with the allocation of moral, political, economic, technical, and legal reasons have been systematized. The preconditions of tax evasion in Ukraine are analyzed, the most common schemes are indicated, resulting from which the budget of Ukraine suffers the greatest losses. Methods of countering tax offenses have been researched and necessity of development and implementation of measures on prevention and countering tax evasion at the State level has been substantiated. Prospects for further researches in this direction are studying of foreign experience of countering tax evasion and detailed analyzing of the tax minimization schemes prevalent in Ukraine with the purpose of identifying ways of elimination of possibility of their use.

Analysis of counter flow of corona wind for heat transfer enhancement

Science.gov (United States)

Shin, Dong Ho; Baek, Soo Hong; Ko, Han Seo

2018-03-01

A heat sink for cooling devices using the counter flow of a corona wind was developed in this study. Detailed information about the numerical investigations of forced convection using the corona wind was presented. The fins of the heat sink using the counter flow of a corona wind were also investigated. The corona wind generator with a wire-to-plate electrode arrangement was used for generating the counter flow to the fin. The compact and simple geometric characteristics of the corona wind generator facilitate the application of the heat sink using the counter flow, demonstrating the heat sink is effective for cooling electronic devices. Parametric studies were performed to analyze the effect of the counter flow on the fins. Also, the velocity and temperature were measured experimentally for the test mock-up of the heat sink with the corona wind generator to verify the numerical results. From a numerical study, the type of fin and its optimal height, length, and pitch were suggested for various heat fluxes. In addition, the correlations to calculate the mass of the developed heat sink and its cooling performance in terms of the heat transfer coefficient were derived. Finally, the cooling efficiencies corresponding to the mass, applied power, total size, and noise of the devices were compared with the existing commercial central processing unit (CPU) cooling devices with rotor fans. As a result, it was confirmed that the heat sink using the counter flow of the corona wind showed appropriate efficiencies for cooling electronic devices, and is a suitable replacement for the existing cooling device for high power electronics.

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.

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

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.

Programmable automatic alpha--beta air sample counter

International Nuclear Information System (INIS)

Howell, W.P.

1978-01-01

A programmable automatic alpha-beta air sample counter was developed for routine sample counting by operational health physics personnel. The system is composed of an automatic sample changer utilizing a large silicon diode detector, an electronic counting system with energy analysis capability, an automatic data acquisition controller, an interface module, and a teletypewriter with paper tape punch and paper tape reader. The system is operated through the teletypewriter keyboard and the paper tape reader, which are used to instruct the automatic data acquisition controller. Paper tape programs are provided for background counting, Chi 2 test, and sample counting. Output data are printed by the teletypewriter on standard continuous roll or multifold paper. Data are automatically corrected for background and counter efficiency

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.)

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.

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

Standardization of calibration method of whole-body counter. 1. Calibration by using anthropometric phantoms

International Nuclear Information System (INIS)

Ishikawa, Tetsuo; Matsumoto, Masaki; Uchiyama, Masafumi; Kobayashi, Sadayoshi; Mizushita, Seiichi.

1995-01-01

To standardize the calibration methods of whole-body counters, three anthropometric phantoms were manufactured based on dozens of Japanese average value of body size data. Using these phantoms, the calibrations of some whole-body counters were carried out and the comparison of counting efficiency between anthropometric phantoms and block phantoms, which used to be used for the calibration of whole-body counters generally, was implemented. Five whole-body counters, one scanning system, two stationary systems and two chair systems, were used for this study. The following results were derived: As an example, in NIRS scanning system, the counting efficiency of anthropometric phantom of 162cm height was 12.7% greater than that of block phantom of the same height. This means 137 Cs body burdens in adult men used to be estimated with the excess of about 10%. Body burdens tended to be estimated excessively in adult because the difference of counting efficiency between anthropometric phantom and block phantom increases with increase of height. To standardize body burden data measured with various whole-body counters, the calibration of each whole-body counter should be conducted using anthropometric phantoms and phantoms which used to be used for the calibration of that whole-body counter. (author)

Evaluation of in-plant neutron coincidence counters for the measurement of molten salt extraction residues

International Nuclear Information System (INIS)

Langner, D.G.; Russo, P.A.; Wachter, J.R.

1993-01-01

Americium is extracted from plutonium by a molten salt extraction (MSE) process. The residual americium-laden salts are a significant waste stream in this pyrochemical purification process. Rapid assay of MSE residues is desirable to minimize the exposure of personnel to these often high-level emissions. However, the quantitative assay of plutonium in MSE residues is difficult. Variable, unknown (a,n) rates and variable emitted-neutron energy spectra preclude the use of standard neutron coincidence counting techniques with old-generation neutron coincidence counters. Gamma-ray assay methods have not been successful with some residues because of random lumps of plutonium metal. In this paper, we present measurements of MSE residues with two state-of-the-art neutron coincidence counters at the Los Alamos Plutonium Processing Facility: an in-line counter built for the assay of bulk waste material and the pyrochemical multiplicity counter that underwent test and evaluation at that facility. Both of these counters were designed to minimize the effects on measurements of variations in the sample geometry and variable energy spectra of emitted neutrons. These results are compared to measurements made with an HLNCII and with a 20-yr-old in-line well counter. The latter two counters are not optimized in ft sense. We conclude that the newer counters provide significantly improved assay results. The pyrochemical multiplicity counter operated in the conventional coincidence mode provided the best assays overall

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.

Background of external γ radiation in the proportional counters of the SAGE experiment

International Nuclear Information System (INIS)

Gavrin, V.N.; Gorbachev, V.V.

2003-01-01

The effect of external γ radiation on the process of counting 71 Ge decays in the proportional counters of the SAGE experiment measuring the solar-neutrino flux is considered. The systematic uncertainty in the SAGE result due to radon decays inside the air volume surrounding the counters is estimated. The background counting rate in the proportional counters that is caused by γ radiation from the enclosing shield is also determined

The influence of the counter-rotating terms on the superradiant emission

International Nuclear Information System (INIS)

Seke, J.

1984-01-01

Agarwal's master equation for the Dicke model is modified by including the counter-rotating terms. By solving the corresponding equations of motion for the atomic expectation values, it is shown that the counter-rotating terms play an important role in the time evolution of the population inversion and radiation rate

Is counter-terrorism policy evidence-based? What works, what harms, and what is unknown.

Science.gov (United States)

Lum, Cynthia; Kennedy, Leslie W; Sherley, Alison

2008-02-01

Is counter-terrorism policy evidence-based? What works, what harms, and what is unknown. One of the central concerns surrounding counter-terrorism interventions today, given the attention and money spent on them, is whether such interventions are effective. To explore this issue, we conducted a general review of terrorism literature as well as a Campbell systematic review on counter-terrorism strategies. In this article, we summarize some of our findings from these works. Overall, we found an almost complete absence of evaluation research on counter-terrorism strategies and conclude that counter-terrorism policy is not evidence-based. The findings of this review emphasise the need for government leaders, policy makers, researchers, and funding agencies to include and insist on evaluations of the effectiveness of these programs in their agendas.

Timecourse of mirror and counter-mirror effects measured with transcranial magnetic stimulation.

Science.gov (United States)

Cavallo, Andrea; Heyes, Cecilia; Becchio, Cristina; Bird, Geoffrey; Catmur, Caroline

2014-08-01

The human mirror system has been the subject of much research over the past two decades, but little is known about the timecourse of mirror responses. In addition, it is unclear whether mirror and counter-mirror effects follow the same timecourse. We used single-pulse transcranial magnetic stimulation to investigate the timecourse of mirror and counter-mirror responses in the human brain. Experiment 1 demonstrated that mirror responses can be measured from around 200 ms after observed action onset. Experiment 2 demonstrated significant effects of counter-mirror sensorimotor training at all timepoints at which a mirror response was found in Experiment 1 (i.e. from 200 ms onward), indicating that mirror and counter-mirror responses follow the same timecourse. By suggesting similarly direct routes for mirror and counter-mirror responses, these results support the associative account of mirror neuron origins whereby mirror responses arise as a result of correlated sensorimotor experience during development. More generally, they contribute to theorizing regarding mirror neuron function by providing some constraints on how quickly mirror responses can influence social cognition. © The Author (2013). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

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...

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.

Absolute measurement of the activity of 222Rn using a proportional counter

International Nuclear Information System (INIS)

Busch, Ingo; Greupner, Heinz; Keyser, Uwe

2002-01-01

A measuring set-up comprising a proportional counter of calculable 222 Rn efficiency and quantifiable active volume (δ V 222 Rn efficiency is determined by computer simulation of the measured α-spectra. The procedures necessary for absolute measurements by means of the counter are described, and the suitability of the counter for absolute measurements of the 222 Rn activity is proved by experiments. Thus, a new method for the realization of the unit of activity of 222 Rn is obtained, which is independent of the unit of activity of 226 Ra

Over-the-counter medications containing diphenhydramine and doxylamine used by older adults to improve sleep.

Science.gov (United States)

Abraham, Olufunmilola; Schleiden, Loren; Albert, Steven M

2017-08-01

Background The unintentional misuse of over-the-counter sleep aids among older adults is an important public health problem and a focus of Healthy People 2020. Accordingly, the 2015 Beers Criteria for Potentially Inappropriate Medication Use in Older Adults recommends that individuals 65 years or older avoid use of diphenhydramine and doxylamine; however, many over-the-counter sleep products contain these active ingredients. Objective To identify the proportion of older adults using an over-the-counter medication containing diphenhydramine or doxylamine, and compare their characteristics with older adults using an over-the-counter medication that does not contain these ingredients. Setting Study participants were recruited from the Community Registry of the Pittsburgh Claude D. Pepper Older Americans Independence Center. Method The study sample was taken from a larger survey of 1025 participants on sleep health and over-the-counter sleep medication use conducted from February to April 2015. A subset of 169 participants aged 65 and older reporting taking at least one over-the-counter product to improve sleep within the past 30 days (16.5%) were selected for our analysis on associations between participant characteristics and potentially inappropriate use of over-the-counter sleep medications. Main outcome measure The proportion and characteristics of older adults taking at least one over-the-counter medication containing diphenhydramine or doxylamine. Results Of the 223 over-the-counter sleep medications listed by participants, 115 (52%) contained diphenhydramine or doxylamine. Using the Beers Criteria, we found that more than half of participants (59%) had used a potentially inappropriate over-the-counter medication containing diphenhydramine or doxylamine to improve sleep within the past 30 days. Participants taking at least one diphenhydramine or doxylamine containing medication were less likely to be aware of any safety risks in taking over-the-counter sleep

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

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)

On the counting rate-dependent amplitude shifts in proportional counters

International Nuclear Information System (INIS)

Mahesh, K.

1976-01-01

The presence of a positive ion cloud near the anode wire, which has been believed to be the cause of the observed counting rate-dependent peak shifts in proportional counters, does not explain various exhibited features of these shifts. The possibility of other mechanisms involved is, therefore, examined. The columnar recombination of primary ions in the counter is considered to explain the origin of the shifts and their observed features. (Auth.)

Gramscian ‘Counter hegemony’ in Narendra Modi’s New India Perspective

Directory of Open Access Journals (Sweden)

Venkat Rao Pulla

2017-03-01

Full Text Available The counter hegemony   that Gramsci, (1987:344 talks about is about leaders and their understanding and how well they conceptualise the psychology of the masses. Counter hegemonies have transformative power and Modi continues to prove that. In this special editorial, the author reviews the leadership of Mr Modi in India.

The effects of gender stereotypic and counter-stereotypic textbook images on science performance.

Science.gov (United States)

Good, Jessica J; Woodzicka, Julie A; Wingfield, Lylan C

2010-01-01

We investigated the effect of gender stereotypic and counter-stereotypic images on male and female high school students' science comprehension and anxiety. We predicted stereotypic images to induce stereotype threat in females and impair science performance. Counter-stereotypic images were predicted to alleviate threat and enhance female performance. Students read one of three chemistry lessons, each containing the same text, with photograph content varied according to stereotype condition. Participants then completed a comprehension test and anxiety measure. Results indicate that female students had higher comprehension after viewing counter-stereotypic images (female scientists) than after viewing stereotypic images (male scientists). Male students had higher comprehension after viewing stereotypic images than after viewing counter-stereotypic images. Implications for alleviating the gender gap in science achievement are discussed.

Informational and symbolic content of over-the-counter drug advertising on television.

Science.gov (United States)

Tsao, J C

1997-01-01

The informational and symbolic content of 150 over-the-counter drug commercials on television are empirically analyzed in this study. Results on the informational content suggest that over-the-counter drug ads tend to focus on the concern of what the drug will do for the consumer, rather than on the reasons why the drug should be ingested. Accordingly, advertising strategy is centered on consumer awareness of the product as the primary goal. Educational commitment, however, did not seem to be blended into the promotional efforts for over-the-counter drugs. Findings on the symbolic content of over-the-counter drug ads reveal that drug images have been distorted. Performance of most drugs has been portrayed to be simple resolutions to relieve the symptom. Moreover, a casual attitude toward drug usage is encouraged in the commercials, while time lapse of drug effects is overlooked.

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.

26 CFR 1.1092(c)-3 - Qualifying over-the-counter options.

Science.gov (United States)

2010-04-01

... 26 Internal Revenue 11 2010-04-01 2010-04-01 true Qualifying over-the-counter options. 1.1092(c)-3...-counter options. (a) In general. Under section 1092(c)(4)(B)(i), an equity option is not a qualified covered call option unless it is traded on a national securities exchange that is registered with the...

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.

An advanced computer-controlled automatic alpha-beta air sample counter

International Nuclear Information System (INIS)

Howell, W.P.; Bruinekool, D.J.; Stapleton, E.E.

1984-01-01

An improved computer-controlled automatic alpha-beta air sample counter was developed, based upon an earlier automatic air sample counter design. The system consists of an automatic sample changer, an electronic counting system utilizing a large silicon diode detector, a small desk-type microcomputer, a high-speed matrix printer and the necessary data interfaces. The system is operated by commands from the keyboard and programs stored on magnetic tape cassettes. The programs provide for background counting, Chi 2 test, radon subtraction and sample counting for sample periods of one day to one week. Output data are printed by the matrix printer on standard multifold paper. The data output includes gross beta, gross alpha and plutonium results. Data are automatically corrected for background, counter efficiency, and in the gross alpha and plutonium channels, for the presence of radon

Counter-Democratic Surveillance: The Watchful Eye of a Local Institution

DEFF Research Database (Denmark)

Hjelholt, Morten

2014-01-01

mechanisms similar to those described by Foucault, but in the service of society. From this perspective democracy is seen as a composite of two realms – a sphere of electoral representation and a constellation of counter-democratic organizations – in constant tension with each other (Rosanvallon 2008......). The watchful eyes of counter-democratic organizations are particularly made powerful by the rise of the Internet with its spontaneous adaption of watchful functions. However increased awareness and mistrust have led not to broader participation in traditional liberal institutions but to a greater social...... in the interest of the national overseers but correspondingly given as responds to fulfill legal requirements or more loosely defined public concerns. Consequently the watchful eye of a local institution form a counter-democratic sight aimed at the strategic intentions of the Government. The paper introduces...

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%

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

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

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

Space-charge effects of the proportional counters in a multiple-ionization chamber

International Nuclear Information System (INIS)

Mang, M.

1993-01-01

At the ALADIN spectrometer of the GSI in october 1991 for the first time the new multiple ionization chamber was applied, in the two anode planes of which are additional multiwire-proportional counters. The proportional counters are required in order to make the detection of light fragments (Z 4 gold projectiles per second by these positive space charges the homogeneous electric field of the MUSIC is disturbed. This effect is especially strong in the beam plane. As consequence of the space charge additionally electrons are focused on the proportional counter so that their amplitudes in dependence on the beam intensity increase up to the 2.5-fold. Furthermore the y coordinate is falsified, because the electrons are diverted to the medium plane. On the measurement of the x coordinate this diversion has with maximally 0.1% only a small influence. These space-charge effects can be qualitatively described by a schematic model, which assumes a stationary positive space charge. Additionally for the proportional counters, which are not in the beam plane, their resolution was determined. In these counters the space-charge effects are small, because essentially fewer particles are registrated than in the medium MWPC's. By this charges of fragments with Z<10 could be separated. The charge resolution amounted at lithium 0.8 charge units. The position resolution of the proportional counters in y direction was determined to less than 8 mm. The detection probability of the fragments amounts for lithium 90% and from boron all fragments are detected

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

A freeze-dried graphene counter electrode enhances the performance of dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Hung, Kai-Hsiang; Wang, Hong-Wen, E-mail: hongwen@cycu.edu.tw

2014-01-01

A flexible graphene/polyimide (PI) counter electrode without a fluorine-doped tin oxide (FTO) layer has been fabricated for dye-sensitized solar cell (DSSCs) applications. The flexible counter electrode consists of polyimide double-sided tape as a substrate beneath a graphene film acting as the conductive and catalytic layer. Chemically reduced graphene oxide (rGO) on the PI electrode (rGO-PI) shows comparable catalytic activity to that of the reference sputtered platinum/FTO counter electrodes (Sputter-Pt/FTO). A DSSC with a freeze-dried rGO-PI (FD-rGO-PI) counter electrode shows an overall conversion efficiency (η) of 5.45%, while that of the conventional Sputter-Pt/FTO electrode is 5.52%. The DSSC with a thermally dried rGO-PI (Gel-rGO-PI) counter electrode (not freeze-dried) exhibits a smooth morphology and much poorer performance (η = 1.61%). Field emission scanning electron microscopy, electrochemical impedance spectroscopy, and cyclic voltammetry measurements demonstrate that the FD-rGO-PI electrode possesses a porous structure, numerous edges, minimum charge-transfer resistance and a higher electrocatalytic activity toward the I{sub 3}{sup −}/I{sup −} redox couple than that of the Gel-rGO-PI electrode. The high electrocatalytic activity, facile preparation procedure, absence of FTO, and material flexibility render the FD-rGO-PI electrode an ideal alternative to conventional DSSC counter electrodes. - Highlights: • Highly rough and conductive graphene-based counter electrode is synthesized. • The characteristics of graphene surface by freeze drying are different. • The graphene counter electrode exhibits comparable performance to that of sputtered Pt one.

The side-on response of a standard long counter to fast neutrons

International Nuclear Information System (INIS)

Johnson, F.A.

1979-01-01

The response of a standard long counter to neutrons incident into its front face relative to its response to those incident into its side was measured for a range of neutron energies, and an increasing sensitivity to high-energy neutrons incident into the side was evident. The effect of a shadow bar in contributing to an initial degradation in energy of neutrons which then scatter from the surroundings into the counter was suggested by the response of the counter in the side-on orientation as a function of the separation distance of the bar from a source. (Auth.)

Proportional counter with a uniform electric field in the zone of avalanche multiplication of electrons

International Nuclear Information System (INIS)

Marzec, J.; Pawlowski, Z.

1982-01-01

The work describes the construction of a proportional counter with a uniform electric field in the zone of avalanche multiplication of electrons. It has been shown that in this counter filled with Penning's mixtures Ne+Ar+CO 2 , Ne+CH 4 and Ar+C 2 H 2 , much higher resolutions are obtained than in typical cylindrical counters. In the counter described filled with a mixture of Ne+1%CH 4 , a resolution of fwhm=10.5% has been obtained for E=5.9 keV. (orig.)

Start-up of plasma current by electron Bernstein wave

International Nuclear Information System (INIS)

Maekawa, Takashi; Tanaka, Hitoshi; Uehide, Masaki

2009-01-01

Electron cyclotron current drive by electron Bernstein (EB) waves for the start-up and ramp-up of toroidal plasma current with no central solenoid in tokamaks is discussed. It is shown that high N// EB waves have ability to ramp-up the current against the counter voltage from self-induction, where N// is the parallel refractive index to the magnetic field, and they are especially suitable for initial current start-up phase where the bulk electron temperature is low enough to ensure high N// EB waves. (author)

Counter-Rotatable Fan Gas Turbine Engine with Axial Flow Positive Displacement Worm Gas Generator

Science.gov (United States)

Giffin, Rollin George (Inventor); Murrow, Kurt David (Inventor); Fakunle, Oladapo (Inventor)

2014-01-01

A counter-rotatable fan turbine engine includes a counter-rotatable fan section, a worm gas generator, and a low pressure turbine to power the counter-rotatable fan section. The low pressure turbine maybe counter-rotatable or have a single direction of rotation in which case it powers the counter-rotatable fan section through a gearbox. The gas generator has inner and outer bodies having offset inner and outer axes extending through first, second, and third sections of a core assembly. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes and extending radially outwardly and inwardly respectively. The helical blades have first, second, and third twist slopes in the first, second, and third sections respectively. A combustor section extends through at least a portion of the second section.

Introduction of Counter-Proliferation Capabilities in Development States

International Nuclear Information System (INIS)

Caulfield, P.; Edwards, T.; Witkin, A.; Elgebaly, A.

2010-01-01

In recent history we have seen a number of States develop their indigenous industrial skills to a point suitable for the manufacture of nuclear components. Private individuals unbeknown to the State have then utilized this capability to supply directly into proliferation networks - potentially reducing international confidence in such a State. To combat this possibility, a developing State must recognize the challenges that are raised by its emerging skills and take action to introduce measures that not only help the State identify proliferation activities but also ensure the national security of the State. One of those measures might be to develop a capability within the State to recognize and counter the activities of would-be-proliferators. In many States this capability is managed and applied through a dedicated counter-proliferation unit that has strong links with border controls and customs organizations. A counter-proliferation unit, once established could show dramatic returns for a modest investment. The activities of such a Unit could save the State political embarrassment by hindering and narrowing the chances of unintentional proliferation activities. The Unit should not be introduced as part of a Safeguards agreement or as part of a non proliferation treaty. It should rather be established as an act by the State to protect and control its emerging technologies from being involved, willingly or unwittingly, in proliferation activities. This is a sovereign act of the State - solely for its benefit and should not be imposed by any external power. Today's would-be-proliferators around the world cooperate and act together; similarly emerging counter-proliferation units should act and work together in order to be a step ahead of the proliferators. Improved world-wide cooperation should increase the detection rate of proliferation incidents which will in turn curtail the spread of nuclear weapons - for the benefit of all. (author)

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.

High resolution time-of-flight measurements in small and large scintillation counters

International Nuclear Information System (INIS)

D'Agostini, G.; Marini, G.; Martellotti, G.; Massa, F.; Rambaldi, A.; Sciubba, A.

1981-01-01

In a test run, the experimental time-of-flight resolution was measured for several different scintillation counters of small (10 x 5 cm 2 ) and large (100 x 15 cm 2 and 75 x 25 cm 2 ) area. The design characteristics were decided on the basis of theoretical Monte Carlo calculations. We report results using twisted, fish-tail, and rectangular light- guides and different types of scintillator (NE 114 and PILOT U). Time resolution up to approx. equal to 130-150 ps fwhm for the small counters and up to approx. equal to 280-300 ps fwhm for the large counters were obtained. The spatial resolution from time measurements in the large counters is also reported. The results of Monte Carlo calculations on the type of scintillator, the shape and dimensions of the light-guides, and the nature of the external wrapping surfaces - to be used in order to optimize the time resolution - are also summarized. (orig.)

Winning the Battle but Losing the War? Narrative and Counter-Narratives Strategy

Directory of Open Access Journals (Sweden)

Christian Leuprecht

2010-11-01

Full Text Available Since 9/11, intelligence and security services have become particularly concerned about radical ideologies and have looked for ways on how to counter them. One of the strategies has been to develop a counter-narrative. Some authors, including those of this article, are concerned that, in the marketplace of ideas, the West is losing market-share.[1] Communication failures with the Muslim world were cited in a report by a U.S. Department of Defence Advisory Committee as early as 2004.[2] The puzzle this article explores is why, having recognized the problem early on, the data suggest that further ground has since been lost. We posit the problem as having to shift the discourse from one focusing on a single counter-narrative to one of tailoring communications to target specific audiences. The article traces methodological and empirical shortcomings that are at the root of the problem and builds on these findings to develop a model to strategize about counter-narratives.

Counter-Stereotypes and Feminism Promote Leadership Aspirations in Highly Identified Women

OpenAIRE

Leicht, Carola; Goclowska, Malgorzata A.; Van Breen, Jolien A.; de Lemus, Soledad; Randsley de Moura, Georgina

2017-01-01

Although women who highly identify with other women are more susceptible to stereotype threat effects, women's identification might associate with greater leadership aspirations contingent on (1) counter-stereotype salience and (2) feminist identification. When gender counter-stereotypes are salient, women's identification should associate with greater leadership aspiration regardless of feminism, while when gender stereotypes are salient, women's identification would predict greater leadersh...