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Sample records for bf3 counters

  1. Setting up and characterization of 4π -BF3 neutron counter

    International Nuclear Information System (INIS)

    In this paper, the refurbishment and characterization of a 4π-BF3 neutron counter are described. Almost flat efficiency of the outer set of detectors is observed. This counter was extensively used for the measurement of (p, n) cross-sections in the 80's. The counter is made operational with making of new beam line and new electronics

  2. Development of NRESP98 Monte Carlo codes for the calculation of neutron response functions of neutron detectors. Calculation of the response function of spherical BF3 proportional counter

    International Nuclear Information System (INIS)

    The method to calculate the response function of spherical BF3 proportional counter, which is commonly used as neutron dose rate meter and neutron spectrometer with multi moderator system, is developed. As the calculation code for evaluating the response function, the existing code series NRESP, the Monte Carlo code for the calculation of response function of neutron detectors, is selected. However, the application scope of the existing NRESP is restricted, the NRESP98 is tuned as generally applicable code, with expansion of the geometrical condition, the applicable element, etc. The NRESP98 is tested with the response function of the spherical BF3 proportional counter. Including the effect of the distribution of amplification factor, the detailed evaluation of the charged particle transportation and the effect of the statistical distribution, the result of NRESP98 calculation fit the experience within ±10%. (author)

  3. Effect of adding Ar gas on the pulse height distribution of BF3-filled neutron detectors

    Indian Academy of Sciences (India)

    M Padalakshmi; A M Shaikh

    2008-11-01

    Boron trifluoride (BF3) proportional counters are used as detectors for thermal neutrons. They are characterized by high neutron sensitivity and good gamma discriminating properties. Most practical BF3 counters are filled with pure boron trifluoride gas enriched up to 96% 10B. But BF3 is not an ideal proportional counter gas. Worsening of plateau characteristics is observed with increasing radius due to impurities in gas. To overcome this problem, counters are filled with BF3 with an admixture of a more suitable gas such as argon. The dilution of BF3 with argon causes a decrease in detection efficiency, but the pulse height spectrum shows sharper peaks and more stable plateau characteristics than counters filled with pure BF3. The present investigations are under-taken to study the pulse height distribution and other important factors in BF3+Ar filled signal counters for neutron beam applications. Tests are performed with detectors with cylindrical geometry filled with BF3 gas enriched in 10B to 90%, and high purity Ar in different proportions. By analysing pulse height spectra, a value of 6.1 ± 0.2 has been obtained for the branching ratio of the 10B(,) reaction.

  4. A mathematical method to calculate efficiency of BF3 detectors

    Institute of Scientific and Technical Information of China (English)

    SI Fenni; HU Qingyuan; PENG Taiping

    2009-01-01

    In order to calculate absolute efficiency of the BF3 detector, MCNP/4C code is applied to calculate rela-tive efficiency of the BF3 detector first, and then absolute efficiency is figured out through mathematical techniques. Finally an energy response curve of the BF3 detector for 1~20 MeV neutrons is derived. It turns out that efficiency of BF3 detector are relatively uniform for 2~16 MeV neutrons.

  5. Solid-liquid equilibrium in ClF3-BF3 and BrF3-BF3 systems

    International Nuclear Information System (INIS)

    Solid-liquid equilibrium in ClF3-BF3 (1) and BrF3-BF3 (2) systems was measured within the whole range of component concentrations. One congruently melting copmpound (ClF3xBF3) (melting poiunt - 30 deg C) is formed in the system (1). Two incongruently melting compounds: BrF3xBF3 (melting point - 30 deg C) and BrF3x2BF3 (melting point - 121 deg C) were identified in the system (2). Conclusion on relative strength of halogen fluorides in acid-basic interactions according to Lewis was made on the basis of equilibria comparison in HalF5-BF3 and HalF3-BF3 systems

  6. 3He and BF3 Neutron Detector Pressure Effect and Model Comparison

    International Nuclear Information System (INIS)

    Paper for SORMA conference Radiation detection systems for homeland security applications must possess the capability of detecting both gamma rays and neutrons. The radiation portal monitor (RPM) systems that are currently deployed use a plastic scintillator for detecting gamma rays and 3He gas-filled proportional counters for detecting neutrons. Proportional counters filled with 3He are the preferred neutron detectors for use in RPMs because 3He has a large neutron cross section, is relatively insensitive to gamma-rays, is neither toxic nor corrosive, can withstand extreme environments, and can be operated at a lower voltage than some of the alternative proportional counters. The amount of 3He required for homeland security and science applications has depleted the world supply and there is no longer enough available to fill the demand. Thus, alternative neutron detectors are being explored. Two possible temporary solutions that could be utilized while a more permanent solution is being identified are reducing the 3He pressure in the proportional counters and using boron trifluoride (BF3) gas-filled proportional counters. Reducing the amount of 3He required in each of the proportional counters would decrease the rate at which 3He is being used, not enough to solve the shortage but perhaps enough to increase the amount of time available to find a working replacement. BF3 is not appropriate for all situations as these detectors are less sensitive than 3He, BF3 gas is corrosive, and a much higher voltage is required than what is used with 3He detectors. Measurements of the neutron detection efficiency of 3He and BF3 as a function of tube pressure were made. The experimental results were also used to validate models of the RPMs.

  7. Electron Collision Cross Sections for the BF3 Molecule and Electron Transport Coefficients in BF3--Ar and BF3--SiH4 Mixtures

    Science.gov (United States)

    Hien, Pham Xuan; Jeon, Byung-Hoon; Tuan, Do Anh

    2013-03-01

    A consistent set of low-energy electron collision cross sections for the boron trifluoride (BF3) molecule has been derived from the measured electron transport coefficients for a pure BF3 molecule using an electron swarm study and a two-term approximation of the Boltzmann equation for energy. The electron transport coefficients, which were calculated using the derived set, are consistent with the experimental data over a wide range of E/N values (ratio of the electric field E to the neutral number density N). The present set of electron collision cross sections for the BF3 molecule, therefore, is the best available so far for the quantitative numerical modeling of plasma discharges for processing procedures with materials containing BF3 molecules. The electron-transport coefficients for BF3--Ar and BF3--SiH4 mixtures were also calculated and analyzed in a wide range of E/N ratios for the first time. The presence of a remarkable synergism in the Townsend first ionization coefficient has been pointed out in BF3--SiH4 mixtures.

  8. Solid-liquid equilibria in the systems ClF5-BF3 and BrF5-BF3

    International Nuclear Information System (INIS)

    The method of differential thermal analysis has been used to investigate solid-liquid equilibria in the systems ClF5-BF3 and BrF5-BF3 in the whole range of concent-- rations of components. No formation of chemical compounds is found. BrF5-BF3 system refers to the series of simple systems of the eutectic type and is characterized by eutectics depleted in bromine pentafluoride content (less than 5 mol. %) with the melting temperature close to melting temperature of pure boron trifluoride. In the ClF5-BF3 system components are mutually insoluble in both liquid and solid states

  9. Remarkable thermal stability of $BF_3$-doped polyaniline

    OpenAIRE

    Chaudhuri, Debangshu; Menezes, Prashanth W.; Sarma, DD

    2003-01-01

    We show that the recently synthesized BF3-doped polyaniline (PANI) exhibits remarkable stability against thermal ageing. Unlike the protonated PANI, which shows rapid degradation of the conductivity on heating in air, BF3-doped PANI shows more than an order of magnitude improvement in conductivity. We employ x-ray photoelectron spectroscopy (XPS), fourier transform infra-red (FTIR) spectroscopy, and x-ray diffraction (XRD) to understand this unexpected phenomenon.

  10. A thermal neutron proportional detector containing BF-3 gas

    International Nuclear Information System (INIS)

    A thermal neutron proportional detector containing BF-3 gas with pressure of 54 cm Hg has been made in the electronics and instrumentation laboratory Yogyakarta nuclear research center (BATAN). The cathode and anode of the detector are made of aluminum and tungsten with 3 cm and 0,3 mm of diameter respectively. The thermal neutron detection is made through secondary reactions of neutron with boron nucleus that produce alpha particle for ionization of BF-3 gas. The high electric field between the cathode and the anode will attract those pairs of ions to their respective electrodes. The collected ion pairs at the cathode will produce output pulse detector which is equivalent to the in coming neutron energy. The neutron detector characteristics test shows that the detector efficiency is 15.54 %. which counts 6. 41 x 1010 Plateau length to 120 volt with optimal voltage operational is 1285 volt. (author)

  11. Investigations on landmine detection by BF3 detector

    Institute of Scientific and Technical Information of China (English)

    D.Rezaei OCHBELAGH; H.Miri HAKIMABAD; R.Izadi NAJAFABADI

    2007-01-01

    Experiments were carried out to investigate the possible use of neutron backscattering for the detection of polyethylene (PE) sample buried in the soil. In detection of landmine by neutrons, the neutron detector and its shield play an important role. In this paper, the effects of graphite, heavy water, polyethylene and boric acid moderators on the flux of back scattered neutrons were investigated. We have also experimentally verified the effect of BF3 detector shield and obtained good agreement with theory.

  12. BF3 PIII modeling: Implantation, amorphisation and diffusion

    International Nuclear Information System (INIS)

    In the race for highly doped ultra-shallow junctions (USJs) in complementary metal oxide semi-conductor (CMOS) technologies, plasma immersion ion implantation (PIII) is a promising alternative to traditional beamline implantation. Currently, no commercial technology computer aided design (TCAD) process simulator allows modeling the complete USJ fabrication process by PIII, including as-implanted dopant profiles, damage formation, dopant diffusion and activation. In this work, a full simulation of a p-type BF3 PIII USJ has been carried out. In order to investigate the various physical phenomena mentioned above, process conditions included a high energy/high dose case (10 kV, 5×1015 cm−2), specifically designed to increase damage formation, as well as more technology relevant implant conditions (0.5 kV) for comparison. All implanted samples were annealed at different temperatures and times. As implanted profiles for both boron and fluorine in BF3 implants were modeled and compared to Secondary Ion Mass Spectrometry (SIMS) measurements. Amorphous/crystalline (a/c) interface depths were measured by transmission electron microscopy (TEM) and successfully simulated. Diffused profiles simulations agreed with SIMS data at low thermal budgets. A boron peak behind the a/c interface was observed in all annealed SIMS profiles for the 10 kV case, indicating boron trapping from EOR defects in this region even after high thermal budgets. TEM measurements on the annealed samples showed an end of range (EOR) defects survival behind the a/c interface, including large dislocation loops (DLs) lying on (001) plane parallel to the surface. In the last part of this work, activation simulations were compared to Hall measurements and confirmed the need to develop a (001) large BICs model.

  13. A Neutron Rem Counter

    International Nuclear Information System (INIS)

    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 BF3 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 BF3 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

  14. 10BF3 Gas and 10B coating based position sensitive detectors for neutron scattering applications

    International Nuclear Information System (INIS)

    Global scarcity of 3He has made it essential to explore other materials with reasonably high neutron absorption cross section for thermal neutron detectors. There is also a high demand to improve the performance of neutron detectors in view of throughput. 10BF3 gas and 10B coatings in gas filled proportional detector are the favorable and promising options. Performance of BF3 gas and 10B film (90% enriched) based Position Sensitive Detectors (PSDs) in coaxial geometry are evaluated for compatibility with scattering experiments. Though efficiency of these PSDs in equivalent dimensions is lower than that those with 3He, novel designs of cathode structure are being tried to improve efficiency. Challenges in handling BF3 gas due to its toxicity and limitations in fill pressure due to its electronegative nature, limits its popularity. Whereas our in-house facility for BF3 gas generation and distillation enabled us to carry out extensive tests related to geometry parameters of the PSDs, purification of gas through repeated distillations has been helpful to a certain extent. Design parameters such as anode, cathode and fill gas pressure for BF3 filled cylindrical PSDs are optimised for their performance. Time of Flight (TOF) spectrometer is presently being installed at Dhruva reactor. For this purpose, BF3-filled multi-PSD array is under fabrication in-house. Vertically arranged 1 m long cylindrical PSDs will cover the detection area of 3.5 m2 (3.5 m arc-length and 1 m height). BF3 gas based large area PSDs need complex anode-cathode geometry for gain in efficiency. Various challenges in choice of detector fabrication materials are faced. BF3 gas aging with these fabrication materials is studied and results are implemented in the design of multi-tube based PSD. PSDs based on 10B film in coaxial geometry are successfully fabricated and tested with acceptable position resolution. 10B coatings show advantage of non toxic nature but pose challenges like low efficiency, limits

  15. Neutron pulse discrimination of BF3 detector through pulse shape analysis

    International Nuclear Information System (INIS)

    In the nuclear non-proliferation and safeguards, reliable detection and verification of nuclear materials is very important. An assay by passive or active neutron detection is the preferred technique when the sample is too dense to measure the accurate energies of γ-rays from its inside. For accurate neutron measurement, neutrons should be discriminated from γ-rays and other background radiations. In this study, neutron pulses of a BF3 detector were discriminated against other pulses including γ-rays and background radiations by using a CAMAC based pulse processing system to record the distribution of detection events over two-dimension

  16. Study on Digital Pulse Shape Discrimination System in BF3 Detector

    International Nuclear Information System (INIS)

    In this study, we develop the digital PSD system and discriminate the background signal of BF3. Spectrum shapes are different according to the tstart setting method, and it is favorable to set it as the certain ratio of maximum height. In future, it will be performed to vary tstart point to optimize the pulse discrimination. To quantify the performance, Figure Of Merit (FOM) will be determined. For the nuclear non-proliferation and safeguards, an accurate and reliable measurement of nuclear material is essential. The nuclear material emits neutron and γ-ray, simultaneously. For the accurate detection of the nuclear material, neutron should be discriminated from γ-ray or background radiation. In previous study, N. S. Jung developed pulse shape analysis method based on NIM and CAMAC system. However, applications of other discrimination methods based on different detection modules or changing parameters are time-and-money consuming procedures in analogue systems. Today, the performance of digitizers is improved and it replaces some radiation measurement systems which require simple and portable equipment. Digital Pulse Shape Discrimination (PSD) method by using a digital oscilloscope is developed and applied to a neutron detection system by using BF3 detector in this study

  17. Phantoms with 10BF3 detectors for boron neutron capture therapy applications

    International Nuclear Information System (INIS)

    Two acrylic cube phantoms have been constructed for BNCT applications that allow the depth distribution of neutrons to be measured with miniature 10BF3 detectors in 0.5-cm steps beginning at 1-cm depth. Sizes and weights of the cubes are 14 cm, 3.230 kg, and 11 cm, 1.567 kg. Tests were made with the epithermal neutron beam from the patient treatment port of the Brookhaven Medical Research Reactor. Thermal neutron depth profiles were measured with a bare 10BF3 detector at a reactor power of 50 W, and Cd-covered detector profiles were measured at a reactor power of 1 kW. The resulting plots of counting rate versus depth illustrate the dependence of neutron moderation on the size of the phantom. But more importantly the data can serve as benchmarks for testing the thermal and epithermal neutron profiles obtained with accelerator-based BNCT facilities. Such tests could be made with these phantoms at power levels about five orders of magnitude lower than that required for the treatment of patients with brain tumors. copyright 1998 American Association of Physicists in Medicine

  18. 3He and BF3 neutron detector pressure effect and model comparison

    International Nuclear Information System (INIS)

    Radiation detection systems for homeland security applications must possess the capability of detecting both gamma rays and neutrons. The radiation portal monitor systems that are currently deployed use a plastic scintillator for detecting gamma rays and 3He gas-filled proportional counters for detecting neutrons. Proportional counters filled with 3He are the preferred neutron detectors for use in radiation portal monitor systems because 3He has a large neutron cross-section, is relatively insensitive to gamma-rays, is neither toxic nor corrosive, can withstand extreme environments, and can be operated at a lower voltage than some of the alternative proportional counters. The amount of 3He required for homeland security and science applications has depleted the world supply and there is no longer enough available to fill the demand. Thus, alternative neutron detectors are being explored. Two possible temporary solutions that could be utilized while a more permanent solution is being identified are reducing the 3He pressure in the proportional counters and using boron trifluoride gas-filled proportional counters. Reducing the amount of 3He required in each of the proportional counters would decrease the rate at which 3He is being used; not enough to solve the shortage, but perhaps enough to increase the amount of time available to find a working replacement. Boron trifluoride is not appropriate for all situations as these detectors are less sensitive than 3He, boron trifluoride gas is corrosive, and a much higher voltage is required than what is used with 3He detectors. Measurements of the neutron detection efficiency of 3He and boron trifluoride as a function of tube pressure were made. The experimental results were also used to validate models of the radiation portal monitor systems.

  19. Theory of electronic structure and nuclear quadrupole interactions in the BF3 NH3 complex and methyl derivatives

    Science.gov (United States)

    Pink, R. H.; Dubey, Archana; Mahato, Dip N.; Badu, S. R.; Scheicher, R. H.; Mahanti, Mahendra K.; Huang, M. B.; Saha, H. P.; Chow, Lee; Das, T. P.

    2007-04-01

    Magnetic Hyperfine and Nuclear Quadrupole Interactions (HFI and NQI) are now important tools for characterization of systems of interest in materials research and industry. Boron-Trifluoride is an inorganic compound that is very important in this respect as a catalyst in chemical physics research and industry, forming complexes in the process with compounds like ammonia, water and methyl alcohol. The present paper deals with the BF3 NH3 complex and methyl derivatives BF3NHx(CH3)3-x for which we have studied the electronic structures, binding energies, and 19F* ( I = 5/2) nuclear quadrupole interactions using the first-principles Hartree Fock Roothaan procedure combined with electron correlation effects. Our results for the 19F* nuclear quadrupole coupling constant ( e 2 qQ/ h) in units of MHz compare well with experiment. Trends in the binding energies and NQI parameters between the complexes are discussed.

  20. Pulse discrimination of background and gamma-ray source by digital pulse shape discrimination in a BF3 detector

    International Nuclear Information System (INIS)

    As a representative method of non-destructive assay, accurate neutron measurement is difficult due to large background radiation such as γ-ray, secondary radiation, spurious pulse, etc. In a BF3 detector, the process of signal generation is different between neutron and other radiations. As the development of detection technique, all of signal data can be digitized by digital measurement method. In the previous study, Applied Nuclear Physics Group in Seoul National University has developed digital Pulse Shape Discrimination (PSD) method using digital oscilloscope. In this study, optimization of parameters for pulse discrimination is discussed and γ-ray region is determined by measuring 60Co source. The background signal of BF3 detector is discriminated by digital PSD system. Parameters for PSD are optimized through FOM calculation. And the γ-ray region is determined by measuring 60Co source. In the future, the performance of developed system will be tested in low and high intensity neutron field

  1. Theory of electronic structure and nuclear quadrupole interactions in the BF3-NH3 complex and methyl derivatives

    International Nuclear Information System (INIS)

    Magnetic Hyperfine and Nuclear Quadrupole Interactions (HFI and NQI) are now important tools for characterization of systems of interest in materials research and industry. Boron-Trifluoride is an inorganic compound that is very important in this respect as a catalyst in chemical physics research and industry, forming complexes in the process with compounds like ammonia, water and methyl alcohol. The present paper deals with the BF3-NH3 complex and methyl derivatives BF3NHx(CH3)3-x for which we have studied the electronic structures, binding energies, and 19F* (I = 5/2) nuclear quadrupole interactions using the first-principles Hartree-Fock-Roothaan procedure combined with electron correlation effects. Our results for the 19F* nuclear quadrupole coupling constant (e2qQ/h) in units of MHz compare well with experiment. Trends in the binding energies and NQI parameters between the complexes are discussed.

  2. Synthesis of 11C labelled methyl esters: transesterification of enol esters versus BF3 catalysed esterification-a comparative study

    International Nuclear Information System (INIS)

    C-11 labelled methyl esters have been synthesized via the transesterification of enol esters in the presence of C-11 methanol and 1,3 dichlorodibutylstannoxane as catalyst. This method leaves functional groups intact and allows access to a wider variety of C-11 labelled methyl esters compared to the BF3 catalysed ester formation, which uses carboxylic acids and C-11 methanol as starting materials

  3. Simultaneous interactions of pyrimidine ring with BeF2 and BF3 in BeF2⋅⋅⋅X-Pyr⋅⋅⋅BF3 complexes: non-cooperativity.

    Science.gov (United States)

    Ghafari, Saber; Gholipour, Alireza

    2015-10-01

    We investigated the mutual interplay between beryllium and boron bonds in the BeF2⋅⋅⋅X-Pyr⋅⋅⋅BF3 complexes (X = CN, F, Cl, Br, H, CH3, OH and NH2, where Pyr and ⋅⋅⋅ denote pyrimidine ring and beryllium and boron bonds, respectively) at the M06-2X/aug-cc-pVDZ level of theory. The results indicate that non-cooperative effects are observed when the two kinds of noncovalent interactions beryllium and boron bonds coexist in the complexes. These effects were studied in terms of the energetic and geometric features of the complexes. Atoms in molecules (AIM) and natural bond orbital (NBO) analyses were also performed to unveil the mechanism of these interactions in the title complexes. The electron-withdrawing/donating substituents decrease/increase the magnitude of the binding energies compared to the unsubstituted BeF2⋅⋅⋅X-Pyr⋅⋅⋅BF3 (X = H) complex. The Esynvalues are in agreement with the geometric features of the complexes. The results stress the importance of the mutual effects between noncovalent interactions involving aromatic systems. PMID:26361769

  4. Metalated N-heterocyclic reagents prepared by the frustrated Lewis pair TMPMgCl center dot BF3 and their addition to aromatic aldehydes and activated ketones

    OpenAIRE

    Manolikakes, Sophia M.; Jaric, Milica; Karaghiosoff, Konstantin; Knochel, Paul

    2013-01-01

    Treatment of pyridines, quinoline and methylthiopyrazine with the frustrated Lewis pair TMPMgCl center dot BF3 (1) leads to organotrifluoro borates which react readily with a variety of aromatic aldehydes in the absence of a transition metal catalyst.

  5. Enzymatic Hydrolysis of Copra Meal by Mannanase from Streptomyces sp. BF3.1 for The Production of Mannooligosaccharides

    Directory of Open Access Journals (Sweden)

    Ariandi

    2015-04-01

    Full Text Available Copra meal contained high polysaccharide mannan. Mannanase Streptomyces sp. BF3.1 efficiently hydrolyzed copra meal to mannooligosaccharides. This research determined the optimum conditions of enzyme mannanase Streptomyces sp. BF3.1 to hydrolyze copra meal. The results of the hydrolysis products were analyzed concentrations of reducing sugars, total sugars and the degree of polymerization. In order to determine the type of product, mannooligosaccharides were analyzed by thin layer chromatography and high performance liquid chromatography. The mannanase had an optimum condition at 70 °C and pH 6. Optimum conditions of hydrolysis was 10% copra meal concentration with incubation time of 5 h at 30 °C which able to produce a variety of mannooligosaccharides products. Under such conditions, the yield of reducing sugar was 3.83 mg/mL with polymerization degree of 4. Analysis of mannooligosaccharides by thin layer chromatography and high performance liquid chromatography revealed mannobiose, mannotriose, mannotetrose, mannopentose, and mannoheksose.

  6. Theoretical investigation of force field and vibrational spectrum of BF3 molecule by MO LCAO SCF method

    International Nuclear Information System (INIS)

    Non-empirical calculations of equilibrium internuclear distances, force constants, frequencies of normal vibrations, isotope shifts and vibration intensities in IR spectrum of BF3 molecule have been made by MO LCAO SCF method using three bases of grouped gauss functions: DZ (9s5p/4s2p), TZ(10s6p/5s3p) and TZ+P (10s6p1d/5s3p1d). All the three bases lead to the results which are in good agreement with the experimental data. For instance, theoretical values of vibration frequencies differ from the experimental ones by average 3.2; 2.4 and 7.0% in the bases DZ, TZ and TZ+P respectively

  7. Low pressure synthesis of boron nitride with(C2H5)2O·BF3 and Li3N precursor

    Institute of Scientific and Technical Information of China (English)

    WANG Shao-bo; XU Xiao-wei; FAN Hui-li; LI Yu-ping

    2005-01-01

    Cubic boron nitride(c-BN) was synthesized through benzene thermal method at a lower temperature of 300 ℃ by selecting liquid(C2H5)2O·BF3 and Li3N as reactants. Hexagonal boron nitride(h-BN) and orthorhombic boron nitride(o-BN) were also obtained. The samples were characterized by X-ray powder diffractometry and Fourier transformation infrared spectroscopy. The results show that all the BF3, BCl3 and BBr3 in the same family compounds can react with Li3N to synthesize BN since the strongest bond of B-F can be broken. Compared with BBr3, liquid (C2H5)2O·BF3 is cheaper, less toxic and more convenient to operate. Li3N not only provides nitrogen source but also has catalytic effect on accelerating the formation of c-BN at low temperature and pressure.

  8. Insight into 2α-Chloro-2′(2′,6′)-(Di)Halogenopicropodophyllotoxins Reacting with Carboxylic Acids Mediated by BF3·Et2O

    OpenAIRE

    Lingling Fan; Xiaoyan Zhi; Zhiping Che; Hui Xu

    2015-01-01

    Stereospecific nucleophilic substitution at the C-4α position of 2α-chloro-2′(2′,6′)-(di)halogenopicropodophyllotoxin derivatives with carboxylic acids mediated by BF3·Et2O was described. Interestingly, this stereoselective products were completely controlled by the reaction time. That is, if the reaction time was prolonged to 24.5–31 h, the resulting compounds were all transformed into the unusual C-ring aromatization products. Additionally, it demonstrated that BF3·Et2O and reaction tempera...

  9. Nuclear Hyperfine Structure in the Donor – Acceptor Complexes (CH3)3N-BF3 and (CH)33N-B(CH3)3

    Science.gov (United States)

    The donor-acceptor complexes (CH3)3N-BF3 and (CH3)3N-B(CH3)3 have been reinvestigated at high resolution by rotational spectroscopy in a supersonic jet. Nuclear hyperfine structure resulting from both nitrogen and boron has been resolved and quadrupole coupling constants have bee...

  10. Effect of Concentration of Catalyst (BF3-Diethyl Etherate on Synthesis of Polyester From Palm Fatty Acid Distillate (PFAD

    Directory of Open Access Journals (Sweden)

    Renita Manurung

    2013-10-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Palm Fatty Acid Distillate (PFAD can be used as raw material for synthesis polyester. The aim of this research is to synthesis of polyester and to determine the effect of concentration of catalyst on polymerization methyl ester PFAD. The esterification stage was done at temperature 70oC, reaction time 120 minute, reactant ratio 1:8 (PFAD: methanol, concentration of catalyst (H2SO4 1% (w/w PFAD; polymerization stage was done at temperature 126-132°C, polymerization reaction time 4 hours; variation of concentration of catalyst (BF3-diethyl etherate 0%, 6.9%, 9.2%, 11.5% (w/w methyl ester; and polyesterification stage was done at temperature 175-200 oC, reactant ratios (w/w 1:1 (polymerized ME : ethylene glycol, reaction time 4 hours and all of stage was stirred at 150 rpm. The results showed, in the esterification stage was obtained methyl ester with iodine value 77.29 g I2/100 g, viscosity 6.90 cP, density 859.91 kg/m3 and analysis by using GC-MS showed that the purity of methyl ester was 82.23% and molecular weight 267.97 g/mol. Decreasing in iodine value from 77.29 I2 g/100 g to 74.97-59.99 g I2/100 g indicated that the polymerization process had taken place. In polyesterification stage was obtained light brown colored

  11. Novel example of stabilization of the BF3·H2O aquo complex in the [(BF3·H2O)2·18-crown-6·2H2O] compound of the 'guest-host' type

    International Nuclear Information System (INIS)

    [(BF3·H2O)2·18-crown-6·2H2O] complex synthesized by interaction BF3·(C2H5)2O with 18-crown-6 in the presence of moisture. The complex was identified using methods of 1H NMR, vibrational spectroscopy, thermogravimetry, X-ray diffraction analysis. The complex is crystallized in triclinic syngony: a = 7.250(1), b = 8.256(2), c = 10.346(1) A, α = 93.88(1), β = 108.61(2), γ = 111.40(2) deg, Z = 1, sp. gr. P1.14 refs., 3 figs., 1 tab

  12. Insight into 2α-Chloro-2‧(2‧,6‧)-(Di)Halogenopicropodophyllotoxins Reacting with Carboxylic Acids Mediated by BF3·Et2O

    Science.gov (United States)

    Fan, Lingling; Zhi, Xiaoyan; Che, Zhiping; Xu, Hui

    2015-11-01

    Stereospecific nucleophilic substitution at the C-4α position of 2α-chloro-2‧(2‧,6‧)-(di)halogenopicropodophyllotoxin derivatives with carboxylic acids mediated by BF3·Et2O was described. Interestingly, this stereoselective products were completely controlled by the reaction time. That is, if the reaction time was prolonged to 24.5-31 h, the resulting compounds were all transformed into the unusual C-ring aromatization products. Additionally, it demonstrated that BF3·Et2O and reaction temperature were the important factors for C-ring aromatization, and AlCl3 could be substituted for BF3·Et2O as a lewis acid for C-ring aromatization. Halogenation of E-ring of 2β-chloropodophyllotoxins with NCS or NBS also led to the same C-ring aromatization compounds. Especially compounds 5c, 6g and 7b exhibited insecticidal activity equal to that of toosendanin.

  13. Insight into 2α-Chloro-2'(2',6')-(Di)Halogenopicropodophyllotoxins Reacting with Carboxylic Acids Mediated by BF3·Et2O.

    Science.gov (United States)

    Fan, Lingling; Zhi, Xiaoyan; Che, Zhiping; Xu, Hui

    2015-01-01

    Stereospecific nucleophilic substitution at the C-4α position of 2α-chloro-2'(2',6')-(di)halogenopicropodophyllotoxin derivatives with carboxylic acids mediated by BF3·Et2O was described. Interestingly, this stereoselective products were completely controlled by the reaction time. That is, if the reaction time was prolonged to 24.5-31 h, the resulting compounds were all transformed into the unusual C-ring aromatization products. Additionally, it demonstrated that BF3·Et2O and reaction temperature were the important factors for C-ring aromatization, and AlCl3 could be substituted for BF3·Et2O as a lewis acid for C-ring aromatization. Halogenation of E-ring of 2β-chloropodophyllotoxins with NCS or NBS also led to the same C-ring aromatization compounds. Especially compounds 5c, 6g and 7b exhibited insecticidal activity equal to that of toosendanin. PMID:26573374

  14. Nutrition Counter

    Science.gov (United States)

    ... Counter: A Reference For The Kidney Patient AAKP Nutrition Counter: A Reference For The Kidney Patient Buy ... Harum RD, CSR, LD Certified Specialist in Renal Nutrition, Miami, Florida Reviewed by: 2005 – Maria Karalis, MBA, ...

  15. Needle counter

    International Nuclear Information System (INIS)

    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.)

  16. Matrix isolation studies of the interactions of BF3 with water and substituted diethyl ethers. Chemical ionization mass spectrometric determination of the proton affinity of (CF3CH2)2O

    Science.gov (United States)

    Ball, David W.; Zehe, Michael J.

    1993-01-01

    BF3 was co-condensed with H2O, D2O, (C2H5)2O, (CF3CH2)2O, and (C2F5)2O in excess argon at 15 K. Infrared spectra of BF3/water isolated in solid argon provided a more complete analysis of the BF3--H2O complex than previously published. Infrared spectra of the matrices showed a definite Lewis acid-base interaction between BF3 and diethyl ether; a weak but definite interaction with bis (2,2,2-trifluorodiethyl) ether, and no observable interaction with perfluorodiethyl ether. Thus, the ether data indicate a clear trend between strength of interaction with BF3 and the degree of F substitution. To support and explain the emerging relationship between interaction strength and the basicity of the oxygen-containing molecule, the proton affinity of (CF3CH2)2O was measured using chemical ionization mass spectrometry. The implications of the results for lubricant/metal oxide surface interactions are discussed.

  17. A development of NRESPG Monte Carlo code for the calculation of neutron response function for gas counters

    International Nuclear Information System (INIS)

    A Monte Carlo code Neutron RESPonse function for Gas counters (NRESPG) has been developed for the calculation of neutron response functions and efficiencies for neutron energies up to 20 MeV, which can be applied for 3He, H2, or BF3 gas proportional counters with or without moderator. This code can simulate the neutron behavior in a two-dimensional detector configuration and treat the thermal motion of a moderator atom which becomes important as the neutron energy becomes sufficiently low. Further, a more precise measured data was taken to simulate the position-dependent gas multiplication in the sensitive and insensitive gas region of a proportional counter. The NRESPG code has been applied for the calculation of response functions of 3He cylindrical proportional counters to determine neutron energy and neutron fluence in a monoenergetic calibration field. Thus, a remarkable discrepancy in the lower portion of the full-energy peak produced by the 3He(n,p)T reaction can be removed which results in a good agreement between simulations and experiments. The code has been also used for the simulation of the response of a McTaggart-type long counter consisting of a central cylindrical BF3 counter surrounded by a polyethylene moderator. The results of the NRESPG simulations were compared with those obtained from MCNP calculations

  18. Body counter

    International Nuclear Information System (INIS)

    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 47Ca and 85Sr, investigations with iodine and iodine-labelled substances, clearance investigations (in particular the 51Cr EDTA clearance test), as well as the possibilities of neutron activation in vivo. (ORU/AK)

  19. Boron-Lined Multitube Neutron Proportional Counter Test

    Energy Technology Data Exchange (ETDEWEB)

    Woodring, Mitchell L.; Ely, James H.; Kouzes, Richard T.; Stromswold, David C.

    2010-09-07

    Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. The currently deployed radiation portal monitors (RPMs) from Ludlum and Science Applications International Corporation (SAIC) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large neutron detector. There is a declining supply of 3He in the world, and thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. These technologies are: 1) Boron trifluoride (BF3)-filled proportional counters, 2) Boron-lined proportional counters, 3) Lithium-loaded glass fibers, and 4) Coated non-scintillating plastic fibers. In addition, a few other companies have detector technologies that might be competitive in the near term as an alternative technology. Reported here are the results of tests of a boron-lined, “multitube” proportional counter manufactured by Centronic Ltd. (Surry, U.K. and Houston, TX). This testing measured the required performance for neutron detection efficiency and gamma-ray rejection capabilities of the detector.

  20. 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.

  1. Weakly nucleophilic potassium aryltrifluoroborates in palladium-catalyzed Suzuki-Miyaura reactions: relative reactivity of K[4-RC6F4BF3] and the role of silver-assistance in acceleration of transmetallation.

    Science.gov (United States)

    Bardin, Vadim V; Shabalin, Anton Yu; Adonin, Nicolay Yu

    2015-01-01

    Small differences in the reactivity of weakly nucleophilic potassium aryltrifluoroborates are revealed in the silver-assisted Pd-catalyzed cross-coupling of K[4-RC6F4BF3] (R = H, Bu, MeO, EtO, PrO, iPrO, BuO, t-BuO, CH2=CHCH2O, PhCH2O, PhCH2CH2O, PhO, F, pyrazol-1-yl, pyrrol-1-yl, and indol-1-yl) with ArX (4-BrC6H4CH3, 4-IC6H4F and 3-IC6H4F). An assumed role of silver(I) compounds Ag m Y (Y = O, NO3, SO4, BF4, F) consists in polarization of the Pd-X bond in neutral complex ArPdL n X with the generation of the related transition state or formation of [ArPdL n ][XAg m Y] with a highly electrophilic cation and subsequent transmetallation with the weakly nucleophilic borate. Efficiency of Ag m Y as a polarizing agent decreases in order Ag2O > AgNO3 ≈ Ag2SO4 > Ag[BF4] > AgF. No clear correlation between the reactivity of K[4-RC6F4BF3] and substituent electron parameters, σI and σR°, of the aryl group 4-RC6F4 was found. PMID:26124862

  2. FLEXIBLE GEIGER COUNTER

    Science.gov (United States)

    Richter, H.G.; Gillespie, A.S. Jr.

    1963-11-12

    A flexible Geiger counter constructed from materials composed of vinyl chloride polymerized with plasticizers or co-polymers is presented. The counter can be made either by attaching short segments of corrugated plastic sleeving together, or by starting with a length of vacuum cleaner hose composed of the above materials. The anode is maintained substantially axial Within the sleeving or hose during tube flexing by means of polystyrene spacer disks or an easily assembled polyethylene flexible cage assembly. The cathode is a wire spiraled on the outside of the counter. The sleeving or hose is fitted with glass end-pieces or any other good insulator to maintain the anode wire taut and to admit a counting gas mixture into the counter. Having the cathode wire on the outside of the counter substantially eliminates the objectional sheath effect of prior counters and permits counting rates up to 300,000 counts per minute. (AEC)

  3. Molecular Orbital and Density Functional Study of the Formation, Charge Transfer, Bonding and the Conformational Isomerism of the Boron Trifluoride (BF3 and Ammonia (NH3 Donor-Acceptor Complex

    Directory of Open Access Journals (Sweden)

    Dulal C. Ghosh

    2004-09-01

    Full Text Available The formation of the F3B–NH3 supermolecule by chemical interaction of its fragment parts, BF3 and NH3, and the dynamics of internal rotation about the ‘B–N’ bond have been studied in terms of parameters provided by the molecular orbital and density functional theories. It is found that the pairs of frontier orbitals of the interacting fragments have matching symmetry and are involved in the charge transfer interaction. The donation process stems from the HOMO of the donor into the LUMO of the acceptor and simultaneously, back donation stems from the HOMO of acceptor into the LUMO of the donor. The density functional computation of chemical activation in the donor and acceptor fragments, associated with the physical process of structural reorganization just prior to the event of chemical reaction, indicates that BF3 becomes more acidic and NH3 becomes more basic, compared to their separate equilibrium states. Theoretically it is observed that the chemical reaction event of the formation of the supermolecule from its fragment parts is in accordance with the chemical potential equalization principle of the density functional theory and the electronegativity equalization principle of Sanderson. The energetics of the chemical reaction, the magnitude of the net charge transfer and the energy of the newly formed bond are quite consistent, both internally and with the principle of maximum hardness, PMH. The dynamics of the internal rotation of one part with respect to the other part of the supermolecule about the ‘B–N’ bond mimics the pattern of the conformational isomerism of the isostructural ethane molecule. It is also observed that the dynamics and evolution of molecular conformations as a function of dihedral angles is also in accordance with the principle of maximum hardness, PMH. Quite consistent with spectroscopic predictions, the height of the molecule

  4. The first CEDAR counter

    CERN Multimedia

    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.

  5. A large Cerenkov counter

    CERN Multimedia

    1981-01-01

    The photo shows the vertex Cerenkov counter C0 back side (with 12 mirrors) of the NA9 experiment. On foreground are members of the team (CERN and Wuppertal Uni), Salvo .., Manfred Poetsch, ..., Jocelyn Thadome, Helmut Braun, Heiner Brueck.

  6. Design of Reversible Counter

    OpenAIRE

    Md. Selim Al Mamun; B. K. Karmaker

    2014-01-01

    This article presents a research work on the design and synthesis of sequential circuits and flip-flops that are available in digital arena; and describes a new synthesis design of reversible counter that is optimized in terms of quantum cost, delay and garbage outputs compared to the existing designs. We proposed a new model of reversible T flip-flop in designing reversible counter.

  7. Crossed-beam experiment for the scattering of low- and intermediate-energy electrons from BF3: A comparative study with XF3 (X = C, N, and CH) molecules.

    Science.gov (United States)

    Hoshino, M; Limão-Vieira, P; Suga, A; Kato, H; Ferreira da Silva, F; Blanco, F; García, G; Tanaka, H

    2015-07-14

    Absolute differential cross sections (DCSs) for electron interaction with BF3 molecules have been measured in the impact energy range of 1.5-200 eV and recorded over a scattering angle range of 15°-150°. These angular distributions have been normalized by reference to the elastic DCSs of the He atom and integrated by employing a modified phase shift analysis procedure to generate integral cross sections (ICSs) and momentum transfer cross sections (MTCSs). The calculations of DCSs and ICSs have been carried out using an independent atom model under the screening corrected additivity rule (IAM-SCAR). The present elastic DCSs have been found to agree well with the results of IAM-SCAR calculation above 20 eV, and also with a recent Schwinger multichannel calculation below 30 eV. Furthermore, in the comparison with the XF3 (X = B, C, N, and CH) molecules, the elastic DCSs reveal a similar angular distribution which are approximately equal in magnitude from 30 to 200 eV. This feature suggests that the elastic scattering is dominated virtually by the 3-outer fluorine atoms surrounding the XF3 molecules. The vibrational DCSs have also been obtained in the energy range of 1.5-15 eV and vibrational analysis based on the angular correlation theory has been carried out to explain the nature of the shape resonances. Limited experiments on vibrational inelastic scattering confirmed the existence of a shape resonance with a peak at 3.8 eV, which is also observed in the vibrational ICS. Finally, the estimated elastic ICSs, MTCSs, as well as total cross sections are compared with the previous cross section data available. PMID:26178111

  8. Compressor surge counter

    Science.gov (United States)

    Castleberry, Kimberly N.

    1983-01-01

    A surge counter for a rotating compressor is provided which detects surging by monitoring the vibration signal from an accelerometer mounted on the shaft bearing of the compressor. The circuit detects a rapid increase in the amplitude envelope of the vibration signal, e.g., 4 dB or greater in less than one second, which is associated with a surge onset and increments a counter. The circuit is rendered non-responsive for a period of about 5 seconds following the detection which corresponds to the duration of the surge condition. This prevents multiple registration of counts during the surge period due to rapid swings in vibration amplitude during the period.

  9. 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)

  10. 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...

  11. Silica aerogel Cherenkov counter

    International Nuclear Information System (INIS)

    A practical method for making silica aerogel Cherenkov counters has been developed at KEK, and some tests were performed to evaluate the performance of the counters. The method for making silica aerogel with refractive index between 1.01 and 1.06 is explained in detail. Chemical reaction with methanol, pressure and temperature conditions, and the structure of the autoclave are described together with the whole process. About 20 l aerogel is now produced per week at KEK. The dimensions of the aerogel module is 200 x 100 x 300 mm3. The aerogel with refractive index larger than 1.06 is produced from the aerogel with refractive index 1.06 by heating it up to about 900 deg C. The refractive index can be controlled by the temperature and duration of heating. Refractive index in relation to these conditions is listed in a table. However, the dispersion of the index is about ten times as large as that for the aerogel with lower index (<1.06). The wave length dependence of the transmission length of light for the aerogel was measured and compared with other data obtained at various laboratories. The performance of the counter was evaluated through the experiment with π beam. Average number of photoelectrons gathered is plotted in relation to momentum. It is deduced from the experiment that the saturation thickness of the aerogel is about 10 cm. Two examples of the practical use of the aerogel counter at KEK are also shortly described. (Aoki, K.)

  12. Aerogel threshold Cherenkov counter

    International Nuclear Information System (INIS)

    The results of studying the SiO2 aerogel properties, used as radiator for the Cherenkov counters are presented. Brief data on the technology of preparing the aerogel samples and their optical characteristics are indicated. The formula binding the aerogel refractive index with its density with an account of light dispersion is analyzed. The results of the Cherenkov aerogel threshold counter testing on the charged particles beam within the pulse range of p = ∼ 0.4-2.5 eV/s are presented. The registration efficiency of pions with p ≥ 1 GeV/s constituted ∼ 97% and that of protons - ∼ 4% by the p ≤ 2.5 GeV/s

  13. Holography without Counter Terms

    CERN Document Server

    Ahn, Byoungjoon; Kim, Kyung Kiu; Park, Sang-A; Yi, Sang-Heon

    2016-01-01

    By using the scaling symmetry in the reduced action formalism, we obtain novel Smarr-like relations for anti-de-Sitter planar black holes, which have useful information in the condensed matter systems through the AdS/CMT correspondence. By using our results, we propose another way to obtain the holographically renormalized on-shell action without counter terms. We find the complete consistency of our results with those in various models discussed in the recent literatures and obtain new implications.

  14. Electromagnetic shower counter

    CERN Multimedia

    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.

  15. A track ion counter

    International Nuclear Information System (INIS)

    A method to measure the frequency of production of ions in a gas is described. The characteristics of a device, which is named a track ion counter, are presented. The counter consists of two cylindrical volumes separated by a diaphragm with 500μm dia. orifice. The device is connected to an oil diffusion pump with high pumping speed. The gas flow through the orifice determines the pressure in the upper and the lower volumes of the device. The positive ions produced in a cylindrical volume above an orifice by charged particles traversing that volume move in a constant electric field. Some of these ions passing through the orifice are accelerated and detected by an electron multiplier. The absolute efficiency of ions detection from the domain above the orifice have been determined. The measurements were carried out for single charged ions of N2, H2, CH4, CO2. The preliminary measurements of the frequency of ions created within cylindrical gas domain equivalent to 0.15nm dia. and 7.6nm height tissue cylinder are reported

  16. Scintillation counter, segmented shield

    International Nuclear Information System (INIS)

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

  17. Space and power efficient hybrid counters array

    Science.gov (United States)

    Gara, Alan G.; Salapura, Valentina

    2010-03-30

    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.

  18. Space and power efficient hybrid counters array

    Science.gov (United States)

    Gara, Alan G.; Salapura, Valentina

    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.

  19. Counter-Learning under Oppression

    Science.gov (United States)

    Kucukaydin, Ilhan

    2010-01-01

    This qualitative study utilized the method of narrative analysis to explore the counter-learning process of an oppressed Kurdish woman from Turkey. Critical constructivism was utilized to analyze counter-learning; Frankfurt School-based Marcusian critical theory was used to analyze the sociopolitical context and its impact on the oppressed. Key…

  20. A plastic scintillation counter prototype

    International Nuclear Information System (INIS)

    A new prototype device for beta-ray measurement, a plastic scintillation counter, was assembled as an alternative device to liquid scintillation counters. This device uses plastic scintillation sheets (PS sheets) as a sample applicator without the use of a liquid scintillator. The performance was evaluated using tritium labeled compounds, and good linearity was observed between the activity and net count rate. The calculated detection limit of the device was 0.01 Bq mL−1 after 10 h measurement for 2 mL sample. - Highlights: • A new device of plastic scintillation counter was developed to measure beta emitters. • High sensitivity with low detection limit was performed for a tritium compound. • A detection limit of tritium was 0.01 Bq mL−1 for a 10 h measurement. • A plastic scintillation counter generated no radioactive organic waste fluid. • A plastic scintillation counter could analyze qualitatively and quantitatively

  1. Oscillatory counter-centrifugation

    Science.gov (United States)

    Xu, Shujing; Nadim, Ali

    2016-02-01

    In ordinary centrifugation, a suspended particle that is heavier than the displaced fluid migrates away from the rotation axis when the fluid-filled container rotates steadily about that axis. In contrast a particle that is lighter than the displaced fluid (e.g., a bubble) migrates toward the rotation axis in a centrifuge. In this paper, we show theoretically that if a fluid-filled container rotates in an oscillatory manner as a rigid body about an axis, at high enough oscillation frequencies, the sense of migration of suspended particles is reversed. That is, in that case particles denser than the fluid migrate inward, while those that are lighter than the fluid move outward. We term this unusual phenomenon "Oscillatory Counter-Centrifugation" or OCC, for short. Through application of the method of averaging to the equations of motion, we derive a simple criterion to predict the occurrence of OCC. The analysis also reveals that the time-average of the Coriolis force in the radial direction is the term that is responsible for this effect. In addition, we analyze the effects of the Basset history force and the Rubinow-Keller lift force on particle trajectories and find that OCC persists even when these forces are active. The phenomenon awaits experimental verification.

  2. 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 ... Others help manage recurring problems, like migraines. In the United States, the Food and Drug Administration decides ...

  3. A proportional counter with reduced wall effect

    International Nuclear Information System (INIS)

    A proportional counter, using gaseous sources, in which the wall effects are considerably reduced, is described. The counter is fitted with a ring of internal shielding counters in anti-coincidence, separated from the main central counter only by a number of cathode wires. The counter can be readily assembled, giving flexibility in research investigations. Applications to a measurement of the L/K capture ratio in A37 and Fe55 are described. (author)

  4. Novel Components for Neutron Counters

    International Nuclear Information System (INIS)

    Neutron counters for safeguards proposes have been developed during the last thirty years at the Joint Research Centre. The paper describes some of the latest developments and implementations in modern neutron counter. The design of a neutron counter is nowadays largely done by MCNP calculations. We have studied the behaviour of some components for a specific counter with respect to optimising the performance of the counter. This includes the moderator materials, thermal neutron absorbers, and 3-He detectors. Also the electronics for neutron counter has evolved over the years. Modern neutron counters require a large number of detectors and signal amplifiers to provide optimised parameters for the data interpretation. For this purpose we have developed a new pre-amplifier/amplifier/discriminator circuit which is both compact and inexpensive. The new circuit will be used in existing and future neutron counters. Concerning the treatment of the digital signal pulse train we intend to makes use of the latest advances in computer technology. A novel electronic system has been developed with a maximum of 128 input channels, which can cope with the high count rate of more than 1 million counts per second with zero dead-time. The Multi Input-Pulse Train Analysis (MI-PTA) system can be used with standard instruments, like Shift Register Analysers. However, it has been designed to perform a variety of pulse train analysis techniques itself, or in combination with a Personal Computer to which the system is connected via a High Speed USB2.0 connection. Pulse data can exchanged between the MI-PTA and PC at the rate of 480 Mb/s, allowing real time analysis on a PC and providing the basis for a Virtual Instrument approach: by modifying the software new instruments can be configured. The system consists of a number of base units, each with 8 TTL compatible inputs. Only one unit, configured as a Master, is connected to a PC. Up-to 15 Slave units can be connected to the Master via a

  5. Explosion-proof scintillation counter

    International Nuclear Information System (INIS)

    It is noted that measuring devices used in the research works conducted with the help of radioactive isotopes on the chemical industry installations dangerous from the point of view of explosions, especially on the installations of the petrochemistry industry, must not limit the exploitation safety of these installations. The said especially concerns with the Geiger-Mueller type counters and scintillation detectors, located immediately in the places of measurements on the installations and supplied by high voltage power supply. It has been shown that electronic circuits for the detector's signals processing and obtaining working voltages can be located out of the explosive dangerous premices, for example, in the car trailer. Description is given of the device, with the help of which explosion safety is provided for the serially produced scintillation counter with forced ventilation (counter of the VA-S-50 type). Due to this device application, the exploitation parameters of the counter do not go down and there is no need for any changes in its design. Description is given of the device for external power supply and control of the counter which can swich off the power supply in the case of an accident, dangerous from the point of view of violation of the explosion safety conditions. The device is described for providing service to 10 measuring chanels, mounted on the car trailer

  6. Control stand of scintillation counters

    International Nuclear Information System (INIS)

    Paper describes a stand designed to test complex optical elements of the CMS endwindow hadron calorimeter. The optical element (the megatile) represents an assembly where 19 trapezoidal scintillators are sandwiched in light-absorbing and light-reflecting layers. The stand to test the quality of scintillation counters consists of a bench with a carriage double-coordinated actuation mechanism, a group of photodetectors, a high-voltage power unit, a laser control checking system, a PC and a scintillation counter to calibrate photodetectors. One studies in detail the procedure to test megatiles in the course of which minimum 100 trigger statistics is ensured for every megatile

  7. The Micro Trench Gas Counter

    International Nuclear Information System (INIS)

    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 55Fe 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

  8. Counter-Rotating Accretion Discs

    CERN Document Server

    Dyda, Sergei; Ustyugova, Galina V; Romanova, Marina M; Koldoba, Alexander V

    2014-01-01

    Counter-rotating discs can arise from the accretion of a counter-rotating gas cloud onto the surface of an existing co-rotating disc or from the counter-rotating gas moving radially inward to the outer edge of an existing disc. At the interface, the two components mix to produce gas or plasma with zero net angular momentum which tends to free-fall towards the disc center. We discuss high-resolution axisymmetric hydrodynamic simulations of a viscous counter-rotating disc for cases where the two components are vertically separated and radially separated. The viscosity is described by an isotropic $\\alpha-$viscosity including all terms in the viscous stress tensor. For the vertically separated components a shear layer forms between them. The middle of this layer free-falls to the disk center. The accretion rates are increased by factors $\\sim 10^2-10^4$ over that of a conventional disc rotating in one direction with the same viscosity. The vertical width of the shear layer and the accretion rate are strongly dep...

  9. Basic Research Needs for Countering Terrorism

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-03-01

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

  10. GM Counters: Potential Measurement Uncertainty Sources

    International Nuclear Information System (INIS)

    This paper describes theoretically potential measurement uncertainty sources in radiation detection by GM counters. Procedure of obtaining expanded and combined uncertainties is shown experimentally for four technologically different types of GM counters. Based on experimental results obtained, it has been established that the uncertainties of an influenced random variables depend on the technological solution of the counter reading system and contribute in different ways to the expanded and combined uncertainty of the applied types of GM counters. (author)

  11. Large area flow gas proportional counters

    International Nuclear Information System (INIS)

    The ZJ-LD-800 and ZJ-LD-240 large area flow gas proportional counter tubes are described in detail, and the design of counter tube is expounded. The counter tube there have better than plateau length of 200 V and plateau slope of 2%/100 V and window uniformity of 90% for beta counting. So the counters are ideally suitable for use in Area and Contamination Monitors where both alpha and beta radiation are anticipated

  12. Risk assessment for one-counter threads

    NARCIS (Netherlands)

    A. Ponse; M.B. van der Zwaag

    2008-01-01

    Threads as contained in a thread algebra are used for the modeling of sequential program behavior. A thread that may use a counter to control its execution is called a ‘one-counter thread’. In this paper the decidability of risk assessment (a certain form of action forecasting) for one-counter threa

  13. Tritium measurement with a proportional counter

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate a feasibility of real-time measurement of tritium concentration with a proportional counter. For the purpose, we constructed a flow-through type of proportional counter. The characteristics of the counter for seven gases, PR, H2, D2, Ar, CH4, N2, and air, were investigated to research appropriate gases. (author)

  14. Science Experimenter: Experimenting with a Geiger Counter.

    Science.gov (United States)

    Mims, Forrest M., III

    1992-01-01

    Describes the use of geiger counters for scientific investigations and experiments. Presents information about background radiation, its sources and detection. Describes how geiger counters work and other methods of radiation detection. Provides purchasing information for geiger counters, related computer software and equipment. (MCO)

  15. Counter-Rotation in Disk Galaxies

    OpenAIRE

    Corsini, E. M.

    2014-01-01

    Counter-rotating galaxies host two components rotating in opposite directions with respect to each other. The kinematic and morphological properties of lenticulars and spirals hosting counter-rotating components are reviewed. Statistics of the counter-rotating galaxies and analysis of their stellar populations provide constraints on the formation scenarios which include both environmental and internal processes.

  16. BF3-doped polyaniline: A novel conducting polymer

    Indian Academy of Sciences (India)

    Debangshu Chaudhuri; D D Sarma

    2006-07-01

    We review the unusual structural, transport and magnetic properties of highly conducting polyaniline, doped with boron trifluoride. Our studies establish the unique conducting state of this system, which is in distinct contrast with the conventional proton-doped polyaniline samples.

  17. Discharge quenching circuit for counters

    International Nuclear Information System (INIS)

    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

  18. Proportional counter as neutron detector

    Science.gov (United States)

    Braby, L. A.; Badhwar, G. D.

    2001-01-01

    A technique to separate out the dose, and lineal energy spectra of neutrons and charged particles is described. It is based on using two proportional counters, one with a wall, and the other with similar characteristics but wall made from a non-hydrogen containing material. Results of a calibration in a neutron field are also shown. c2001 Elsevier Science Ltd. All rights reserved.

  19. Scintillation counter based radiation dosimeter

    International Nuclear Information System (INIS)

    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

  20. Condensation Particle Counter Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-01

    The Model 3772 CPC is a compact, rugged, and full-featured instrument that detects airborne particles down to 10 nm in diameter, at an aerosol flow rate of 1.0 lpm, over a concentration range from 0 to 1x104 #/cc. This CPC is ideally suited for applications without high concentration measurements, such as basic aerosol research, filter and air-cleaner testing, particle counter calibrations, environmental monitoring, mobile aerosol studies, particle shedding and component testing, and atmospheric and climate studies.

  1. Programmable spark counter of tracks

    International Nuclear Information System (INIS)

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

  2. Synchronous Counters Implemented in the PLD Devices

    Directory of Open Access Journals (Sweden)

    J. Kolouch

    1999-04-01

    Full Text Available The implementability of synchronous counters in the Programmable Logic Devices (PLD is discussed in this paper. The most commonly used counters are analysed from this point of view. The expressions for their individual bits are given and the number of product terms is derived to allow to estimate the size of the particular counter which can be implemented in the chosen PLD.

  3. Cherenkov counter for particle identification test beam

    International Nuclear Information System (INIS)

    The Cherenkov counter used for selecting electrons of the test beam has been studied in this article. The design, manufacture, assembly and testing of the Cherenkov counter are described. And the performance of this counter is measured. The CO2 gas is used as Cherenkov radiator, the XP2020Q photomultiplier is applied for recording signals of the Cherenkov light. The (99.0±0.5)% efficiency of the electron selection has been reached

  4. Compact fission counter for DANCE

    International Nuclear Information System (INIS)

    The Detector for Advanced Neutron Capture Experiments (DANCE) consists of 160 BF2 crystals with equal solid-angle coverage. DANCE is a 4π γ-ray calorimeter and designed to study the neutron-capture reactions on small quantities of radioactive and rare stable nuclei. These reactions are important for the radiochemistry applications and modeling the element production in stars. The recognition of capture event is made by the summed γ-ray energy which is equivalent of the reaction Q-value and unique for a given capture reaction. For a selective group of actinides, where the neutron-induced fission reaction competes favorably with the neutron capture reaction, additional signature is needed to distinguish between fission and capture γ rays for the DANCE measurement. This can be accomplished by introducing a detector system to tag fission fragments and thus establish a unique signature for the fission event. Once this system is implemented, one has the opportunity to study not only the capture but also fission reactions. A parallel-plate avalanche counter (PPAC) has many advantages for the detection of heavy charged particles such as fission fragments. These include fast timing, resistance to radiation damage, and tolerance of high counting rate. A PPAC also can be tuned to be insensitive to α particles, which is important for experiments with α-emitting actinides. Therefore, a PPAC is an ideal detector for experiments requiring a fast and clean trigger for fission. A PPAC with an ingenious design was fabricated in 2006 by integrating amplifiers into the target assembly. However, this counter was proved to be unsuitable for this application because of issues related to the stability of amplifiers and the ability to separate fission fragments from α's. Therefore, a new design is needed. A LLNL proposal to develop a new PPAC for DANCE was funded by NA22 in FY09. The design goal is to minimize the mass for the proposed counter and still be able to maintain a stable

  5. Compact fission counter for DANCE

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C Y; Chyzh, A; Kwan, E; Henderson, R; Gostic, J; Carter, D; Bredeweg, T; Couture, A; Jandel, M; Ullmann, J

    2010-11-06

    The Detector for Advanced Neutron Capture Experiments (DANCE) consists of 160 BF{sub 2} crystals with equal solid-angle coverage. DANCE is a 4{pi} {gamma}-ray calorimeter and designed to study the neutron-capture reactions on small quantities of radioactive and rare stable nuclei. These reactions are important for the radiochemistry applications and modeling the element production in stars. The recognition of capture event is made by the summed {gamma}-ray energy which is equivalent of the reaction Q-value and unique for a given capture reaction. For a selective group of actinides, where the neutron-induced fission reaction competes favorably with the neutron capture reaction, additional signature is needed to distinguish between fission and capture {gamma} rays for the DANCE measurement. This can be accomplished by introducing a detector system to tag fission fragments and thus establish a unique signature for the fission event. Once this system is implemented, one has the opportunity to study not only the capture but also fission reactions. A parallel-plate avalanche counter (PPAC) has many advantages for the detection of heavy charged particles such as fission fragments. These include fast timing, resistance to radiation damage, and tolerance of high counting rate. A PPAC also can be tuned to be insensitive to {alpha} particles, which is important for experiments with {alpha}-emitting actinides. Therefore, a PPAC is an ideal detector for experiments requiring a fast and clean trigger for fission. A PPAC with an ingenious design was fabricated in 2006 by integrating amplifiers into the target assembly. However, this counter was proved to be unsuitable for this application because of issues related to the stability of amplifiers and the ability to separate fission fragments from {alpha}'s. Therefore, a new design is needed. A LLNL proposal to develop a new PPAC for DANCE was funded by NA22 in FY09. The design goal is to minimize the mass for the proposed

  6. Scintillation counter: photomultiplier tube alignment

    International Nuclear Information System (INIS)

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

  7. Scintillation counter, maximum gamma aspect

    International Nuclear Information System (INIS)

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

  8. Countering 21st Century Threats

    DEFF Research Database (Denmark)

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

    2015-01-01

    The United States and its Allies confront an increasingly volatile world where threats range from traditional state-on-state challenges to non-state transnational networks. To successfully combat these 21st Century problems, in an era of resource and geo-political power constraints, the U.S. and......), 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 of...... shared interests pre-crisis. • Establish political agreements and/or intentions with partners to address potential threats. • Establishing mutual trust through Building Partnership Capacity with capable SOF and intelligence organizations....

  9. 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.

  10. The Ω Counter, a Frequency Counter Based on the Linear Regression.

    Science.gov (United States)

    Rubiola, Enrico; Lenczner, Michel; Bourgeois, Pierre-Yves; Vernotte, Francois

    2016-07-01

    This paper introduces the Ω counter, a frequency counter-i.e., a frequency-to-digital converter-based on the linear regression (LR) algorithm on time stamps. We discuss the noise of the electronics. We derive the statistical properties of the Ω counter on rigorous mathematical basis, including the weighted measure and the frequency response. We describe an implementation based on a system on chip, under test in our laboratory, and we compare the Ω counter to the traditional Π and Λ counters. The LR exhibits the optimum rejection of white phase noise, superior to that of the Π and Λ counters. White noise is the major practical problem of wideband digital electronics, both in the instrument internal circuits and in the fast processes, which we may want to measure. With a measurement time τ , the variance is proportional to 1/τ(2) for the Π counter, and to 1/τ(3) for both the Λ and Ω counters. However, the Ω counter has the smallest possible variance, 1.25 dB smaller than that of the Λ counter. The Ω counter finds a natural application in the measurement of the parabolic variance, described in the companion article in this Journal [vol. 63 no. 4 pp. 611-623, April 2016 (Special Issue on the 50th Anniversary of the Allan Variance), DOI 10.1109/TUFFC.2015.2499325]. PMID:27244731

  11. The Omega Counter, a Frequency Counter Based on the Linear Regression

    CERN Document Server

    Rubiola, E; Bourgeois, P -Y; Vernotte, F

    2015-01-01

    This article introduces the {\\Omega} counter, a frequency counter -- or a frequency-to-digital converter, in a different jargon -- based on the Linear Regression (LR) algorithm on time stamps. We discuss the noise of the electronics. We derive the statistical properties of the {\\Omega} counter on rigorous mathematical basis, including the weighted measure and the frequency response. We describe an implementation based on a SoC, under test in our laboratory, and we compare the {\\Omega} counter to the traditional {\\Pi} and {\\Lambda} counters. The LR exhibits optimum rejection of white phase noise, superior to that of the {\\Pi} and {\\Lambda} counters. White noise is the major practical problem of wideband digital electronics, both in the instrument internal circuits and in the fast processes which we may want to measure. The {\\Omega} counter finds a natural application in the measurement of the Parabolic Variance, described in the companion article arXiv:1506.00687 [physics.data-an].

  12. Over-the-Counter Medicines: What's Right for You?

    Science.gov (United States)

    ... counter medicine (OTCs) Over-the-Counter Medicines: What's Right for You? Share Tweet Linkedin Pin it More ... org Back to top More in Choosing the right over-the-counter medicine (OTCs) Resources for You ...

  13. The Principal and Staff Development: Countering the School Culture.

    Science.gov (United States)

    Martin, Mary; Rogus, Joseph F.

    1979-01-01

    After addressing the problems inherent in developing staff improvement programs, the author offers starter planning steps for countering the energy drainage of teachers, countering the weak technology of teaching, and countering the feeling of aloneness of the teacher. (KC)

  14. GEIGER-MULLER TYPE COUNTER TUBE

    Science.gov (United States)

    Fowler, I.L.; Watt, L.A.K.

    1959-12-15

    A single counter tube capable of responding to a wide range of intensities is described. The counter tube comprises a tubular cathode and an anode extending centrally of the cathode. The spacing between the outer surface of the anode and the inner surface of the cathode is varied along the length of the tube to provide different counting volumes in adjacent portions of the tube. A large counting volume in one portion adjacent to a low-energy absorption window gives adequate sensitivity for measuring lowintensity radiation, while a smaller volume with close electrode spacing is provided in the counter to make possible measurement of intense garnma radiation fields.

  15. A new type of gas scintillation counter

    International Nuclear Information System (INIS)

    Design and construction of a new type of gas scintillation counter are discussed. It includes a scintillation gas proportional counter coupled to a photomultiplier. The electric field applied to the counter in the proportional region increases the number of photons resulting of the excitation of the inert gas, during the discharge produced by the passage of the primary ionizing particle. The number of initial photons is then increased and so is the impulse amplitude of the photomultiplier. The complexity of the electronic system necessary for the observation is thereby reduced. The influence of the electricfield on the resolution of the detector is especially emphasized. (I. C. R.)

  16. Note on the Typ. 2 counter problem

    International Nuclear Information System (INIS)

    The distribution function of the distance between two successive registered particles if the distribution function of the primary process, pulse distribution and the counter type and known is determined on the basis of the joint Laplace transform. The generating function of the number of particles arriving to the counting device during the dead time for the so-called Type 2 counter (counter with prolonging dead time) is determined toon some remarks on the registrations of m types of particles (m>= 1) are made

  17. Position sensitive counter development at the linac

    International Nuclear Information System (INIS)

    In a novel application of the multiwire proportional counter we have imaged a collimated neutron beam. Although preliminary, the results are of sufficient import to be described here because of the potential wide application of the multiwire proportional counter to Laboratory problems. The counter was operated with a counting gas pressure of 20 Torr; the counting gas was pure C4H10. The radiator was a 235U foil. Under these conditions, the counter is (1) relatively insensitive to charged particles (other than fission fragments), (2) insensitive to γ-radiation, and (3) has an efficiency for the detection of fission fragments independent of incident neutron energy over a wide range of neutron energies

  18. Development of a Mobile Ice Nucleus Counter

    Energy Technology Data Exchange (ETDEWEB)

    Kok, Gregory; Kulkarni, Gourihar

    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 deg C, and a single stage system can operate the warm wall at -45 deg C. 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.

  19. Counter public spheres and global modernity

    OpenAIRE

    Fenton, Natalie; Downey, John

    2015-01-01

    This article explores the concept of counter public spheres and their relationship to the dominant public sphere. We argue that counter public spheres are increasingly relevant due to particular social and political configurations that mark out a distinct stage of modernity. We suggest that this stage is characterised in particular by the intensification of globalisation, the rise of neo-liberalism and a decline of trust and social democracy resulting in instability in the dominant public sph...

  20. Counter public spheres and global modernity:

    OpenAIRE

    Downey, John; Fenton, Natalie

    2003-01-01

    This article explores the concept of counter public spheres and their relationship to the dominant public sphere. We argue that counter public spheres are increasingly relevant due to particular social and political configurations that mark out a distinct stage of modernity. We suggest that this stage is characterised in particular by the intensification of globalisation, the rise of neo-liberalism and a decline of trust and social democracy resulting in instability in the dominant public sph...

  1. Synchronization in counter-rotating oscillators

    OpenAIRE

    Bhowmick, S. K.; Ghosh, Dibakar; Dana, Syamal K.

    2011-01-01

    An oscillatory system can have clockwise and anticlockwise senses of rotation. We propose a general rule how to obtain counter-rotating oscillators from the definition of a dynamical system and then investigate synchronization. A type of mixed synchronization emerges in counter-rotating oscillators under diffusive scalar coupling when complete synchronization and antisynchronization coexist in different state variables. Stability conditions of mixed synchronization are obtained analytically i...

  2. Enantiomeric Separations using Chiral Counter-Ions

    OpenAIRE

    Haglöf, Jakob

    2010-01-01

    This thesis describes the use of chiral counter-ions for the enantiomeric separation of amines in non-aqueous capillary electrophoresis. The investigations have been concentrated on studies of the influence, of the chiral counter-ion, the solvent, the electrolyte and the analyte, on the enantioselective separation. Modified divalent dipeptides have been introduced in capillary electrophoresis for the separation of amino alcohols and chiral resolution of amines. Association constants for the i...

  3. The use of polycarbonate in proportional counters

    International Nuclear Information System (INIS)

    Proportional counters are relatively sensitive to contamination through outgassing and the range of electrical insulators suitable for use in their manufacture is quite limited. Although small amounts of plastics such as polychlorotrifluoroethylene have been used as feedthroughs, ceramics are most commonly used when sealed counters with long lives are required. Ceramics have poor and widely scattered mechanical properties and the use of a more robust material is often highly desirable. Of particular interest is the use of polymers and this work examines polycarbonate in particular. To investigate its suitability in terms of outgassing a simple cylindrical, single anode proportional counter containing a large sample of polycarbonate was baked at ∼100 degree C and filled with a CO2/Ar/Xe mixture (5:47.5:47.5 by pressure, respectively). Subsequent measurements of the counter indicated an increase in gain, which, after a second similar filling, was identified to be associated with a preferential loss of CO2 to the polycarbonate. The consequences of this result and the circumstances under which polycarbonate could be used on a large scale in the construction of proportional counters are discussed

  4. CORNELL: CLEO's counters

    International Nuclear Information System (INIS)

    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

  5. Educational cosmic ray experiments with Geiger counters

    CERN Document Server

    Blanco, F; Rocca, P L; Librizzi, F; Parasole, O; Riggi, F

    2006-01-01

    Experiments concerning the physics of cosmic rays offer to high-school teachers and students a relatively easy approach to the field of research in high energy physics. The detection of cosmic rays does not necessarily require the use of sophisticated equipment, and various properties of the cosmic radiation can be observed and analysed even by the use of a single Geiger counter. Nevertheless, the variety of such kind of experiments and the results obtained are limited because of the inclusive nature of these measurements. A significant improvement may be obtained when two or more Geiger counters are operated in coincidence. In this paper we discuss the potential of performing educational cosmic ray experiments with Geiger counters. In order to show also the educational value of coincidence techniques, preliminary results of cosmic ray experiments carried out by the use of a simple coincidence circuit are briefly discussed.

  6. Neutron spectroscopy with the Spherical Proportional Counter

    CERN Document Server

    Bougamont, E; Derre, J; Galan, J; Gerbier, G; Giomataris, I; Gros, M; Katsioulas, I; Jourde, D; Magnier, P; Navick, X F; Papaevangelou, T; Savvidis, I; Tsiledakis, G

    2015-01-01

    A novel large volume spherical proportional counter, recently developed, is used for neutron measurements. Gas mixtures of $N_{2}$ with $C_{2}H_{6}$ and pure $N_{2}$ are studied for thermal and fast neutron detection, providing a new way for the neutron spectroscopy. The neutrons are detected via the ${}^{14}N(n, p)C^{14}$ and ${}^{14}N(n, \\alpha)B^{11}$ reactions. Here we provide studies of the optimum gas mixture, the gas pressure and the most appropriate high voltage supply on the sensor of the detector in order to achieve the maximum amplification and better resolution. The detector is tested for thermal and fast neutrons detection with a ${}^{252}Cf$ and a ${}^{241}Am-{}^{9}Be$ neutron source. The atmospheric neutrons are successfully measured from thermal up to several MeV, well separated from the cosmic ray background. A comparison of the spherical proportional counter with the current available neutron counters is also given.

  7. TOP counter prototype R&D

    Science.gov (United States)

    Inami, K.; Belle-II PID Group

    2011-05-01

    We have been developing a Cherenkov ring-imaging counter, named TOP counter, as a particle-identification device of the Belle-II detector for the super B-factory at KEK. In this presentation, we show the R&D status of the TOP counter prototype. We performed a beam test using 2 m long quartz radiator and MCP-PMTs, and evaluated the number of detected photons, time resolution and chromatic effects. We developed a square-shape MCP-PMT with Hamamatsu photonics, so as to obtain a sufficient lifetime under the Belle-II environment. We improved the lifetime of the quantum efficiency by changing the internal structure and production process, and then obtained a lifetime of >350 mC/cm2.

  8. Development of photocathodes for gas counters

    International Nuclear Information System (INIS)

    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 (< 10 eV). We have particularly studied the response of solid state photocathodes working directly into the counter. We show first a method to increase the quantum efficiency of photocathodes. We experiment this method and take few conclusions. We also show a method to measure the photoelectric threshold of a metal under gas and we apply this method. Because of the limitations of our apparatus we have built a system which permit to manufacture and mesure photocathodes. This apparatus which have numerous possibilities and an automatic data taking system is described. We also describe results of its exploitation and the type of investigation that we are going to develop

  9. Calibration of nuclear medicine gamma counters

    International Nuclear Information System (INIS)

    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)

  10. Whole Body Counters in Biomedical Research

    Directory of Open Access Journals (Sweden)

    S. C. Jain

    1994-01-01

    Full Text Available Whole body counter plays an important role in medical diagnosis and clinical research. It has been used for monitoring of radiation workers for the assessment of internal contamination or assessment of activity in persons exposed to radiation fallout. In a nuclear emergency like Chernobyl, neutron exposure to the radiation victims was assessed by measuring the induced activity of /sup 24/Na. Apart from its use in determining certain element composition in the body, it has got a number of clinical applications like absorption tests, and metabolic and kinetic studies. The work done at INMAS whole body counter facility is also discussed.

  11. An automatic light scattering CCN counter

    Science.gov (United States)

    Lala, G. G.

    1981-11-01

    The counter is a static thermal diffusion chamber which has been modified to include an optical system for the determination of droplet concentration by the measurement of scattered light. The determination of concentration is made by measurement of the peak scattered light signal from the cloud of growing droplets which is a function of both the droplet concentration and chamber supersaturation. Because the formation of the peak is related to the rate of growth of the droplets and sedimentation, both of which are determined by supersaturation, the system calibration can be uniquely determined by comparison with an absolute counter such as a static diffusion chamber with a photographic recording system.

  12. Whole body counters: types, performance and uses

    International Nuclear Information System (INIS)

    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 B12 and albumin. (author)

  13. Extruded plastic counters with WLS fiber readout

    CERN Document Server

    Kudenko, Yu G; Mayatski, V A; Mineev, O V; Yershov, N V

    2001-01-01

    Extruded plastic scintillation counters with WLS fiber readout are described. For a 7 mm thick counter with 4.3 m long double-clad fibers spaced at 7 mm a light yield of 18.7 photoelectrons/MeV and a time resolution of 0.71 ns (sigma) were obtained. A prototype photon veto module consisting of 10 layers of 7 mm thick grooved plastic slabs interleaved with 1 mm lead sheets was also tested, which yielded 122 photoelectrons per minimum ionizing particle and time resolution of 360 ps.

  14. Analysis of counter-rotating wind turbines

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  15. 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.

  16. Energy resolution of the proportional counter

    International Nuclear Information System (INIS)

    Resolution values 11.6% and 12.2% for 5.9 keV have been obtained experimentally for proportional counters with gas fillings Ne+0.5% Ar or Ar+0.5% C2H2. This is appreciably better than earlier measurements which exceed 14%. Theoretical computation indicates that even better resolutions can be obtained. (Auth.)

  17. Ultrafine Condensation Particle Counter Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-01

    The Model 3776 Ultrafine Condensation Particle Counter (UCPC; pictured in Appendix A) is designed for researchers interested in airborne particles smaller than 20 nm. With sensitivity to particles down to 2.5 nm in diameter, this UCPC is ideally suited for atmospheric and climate research, particle formation and growth studies, combustion and engine exhaust research, and nanotechnology research.

  18. Sealed drift tube cosmic ray veto counters

    International Nuclear Information System (INIS)

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

  19. A proportional-scintillation counter beta spectrometer

    International Nuclear Information System (INIS)

    Using a proportional counter for coincidence gating of events in a plastic scintillator provides selective registration of beta interactions in the scintillator. This technique has been used to construct a field instrument that can selectively collect beta spectra (coincidence gating) or gamma spectra (anticoincidence gating). Associated dose rates are calculated from the spectra

  20. Cerenkov counters at the Omega Facility

    CERN Multimedia

    1975-01-01

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

  1. Townsend coefficients of gases in avalanche counters

    International Nuclear Information System (INIS)

    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.)

  2. 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.

  3. One-Counter Markov Decision Processes

    NARCIS (Netherlands)

    Brazdil, T.; Brozek, V.; Etessami, K.; Kucera, A.; Wojtczak, D.K.; Charikar, M.

    2010-01-01

    We study the computational complexity of central analysis problems for One-Counter Markov Decision Processes (OC-MDPs), a class of finitely-presented, countable-state MDPs. OC-MDPs are equivalent to a controlled extension of (discrete-time) Quasi-Birth-Death processes (QBDs), a stochastic model stud

  4. Effectiveness of a Television Counter Advertisement.

    Science.gov (United States)

    Lull, James T.; Mulac, Anthony

    This paper investigates the potential effectiveness of counter advertising in influencing the buying habits of a convinced audience. One month before the actual study, 109 subjects indicated a brand preference in a consumer questionnaire. The subjects were randomly assigned to groups that viewed one of the following: (1) a pro-Bayer aspirin…

  5. Performance of silica aerogel threshold Cerenkov counters

    International Nuclear Information System (INIS)

    Results from a series of test beam measurements are presented for a two-cell silica aerogel Cerenkov counter system. The main achievement is the detection of 13±1 photoelectrons in a full-sized n=1.008 silica aerogel cell which is read out with a fine mesh photomultiplier in different magnetic fields up to 1.35T. (orig.)

  6. A beta and gamma radiation counter device

    International Nuclear Information System (INIS)

    Between 1988 and 1990, 1800 small Geiger-Mueller counters have been distributed in French high schools (caesium 137 as the radioactive source) for pupils' information about radioactivity (vocabulary, protection, ...). The INSTN (Institute for nuclear science and technology) has set up seminars for teachers' formation

  7. Upaya Perumusan Prinsip Counter Accounting Melalui Filosofi Punk sebagai Counter Culture

    OpenAIRE

    Dayno Utama

    2015-01-01

    The aim of this research is to demonstrate that resistance to mainstream research contained in top/elite accounting journals for sparking creativity and innovation unconsciously has utilized the philosophy of punk. The research method of this research is argumentation technique. The result of this research shows that the philosophy of punk as counter culture can be utilized for accounting research through formulation the accounting principles namely counter accounting. Creative and innovative...

  8. Counter-diffusion and counter-permeation of deuterium and hydrogen through palladium

    International Nuclear Information System (INIS)

    Experiments for counter-diffusion and counter-permeation of deuterium and hydrogen through a palladium membrane (25 μm thick) were performed. Deuterium permeation rates as a function of upstream D2 pressure were measured under condition where hydrogen permeated in the opposite direction by supplying H2 gas at the 'other' side (downstream, corresponding to D permeation) of the membrane. It was found that significant deuterium permeation occurred even when the deuterium upstream pressure was much smaller than the hydrogen downstream pressure. The deuterium permeation rate was gradually reduced by increasing the downstream H2 pressure and the corresponding counter H permeation. The deuterium permeation rate under counter H permeation can be represented reasonably well by a simple model in which the ratio of the deuterium permeation rates with and without counter H permeation are assumed to be proportional to the fractional concentration of deuterium in the bulk. However, as the hydrogen counter flow increases, the deuterium permeation rate deviates from the model. This implies that adsorption (absorption) of D2 from the gas phase may be inhibited, and also surface recombination of deuterium may be blocked by hydrogen. (orig.)

  9. Neutron proportional counter with low self-background level

    International Nuclear Information System (INIS)

    It is suggested to cover the inner surface of neutron counter with α-absorption substance layer to reduce level of self-background of neutron counter filled with 3He+30Ar mixture. Application of 50-60 mm thickness fluoroplastic cover turned to be the most perspective. Analysis of energy spectra within 1-10 MeV energy range has shown, that neutron counters with fluoroplastic cover have the background level by one order less, than counters without cover

  10. Expanded uncertainty in measurements of Geiger-Mueller's counter

    International Nuclear Information System (INIS)

    This paper explains the procedure of obtaining expanded uncertainty in measurement for four types of GM counters with the same counter's tube in cases when the contributors of uncertainties in measurement are cosmic background radiation and induced overvoltage phenomenon. According to experiment and obtained experimental results it is established that uncertainties of influenced random variables depend on technological solution of counter and for that purpose they give different contribution to expanded uncertainty in measurement of applied GM counters

  11. Efficiency calibration of solid track spark auto counter

    International Nuclear Information System (INIS)

    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)

  12. 21 CFR 870.5225 - External counter-pulsating device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false External counter-pulsating device. 870.5225... counter-pulsating device. (a) Identification. An external counter-pulsating device is a noninvasive device used to assist the heart by applying positive or negative pressure to one or more of the body's...

  13. 21 CFR 864.5200 - Automated cell counter.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated cell counter. 864.5200 Section 864.5200....5200 Automated cell counter. (a) Identification. An automated cell counter is a fully-automated or semi... corpuscular hemoglobin concentration). These devices may use either an electronic particle counting method...

  14. Scintillation Counters for Neutron Scattering Experiments

    International Nuclear Information System (INIS)

    Scintillation counters discussed in this paper are of two types : (i) UP or B2O3 fixed with zinc sulphide in varving composition, (ii) Li containing glasses of varying composition. The ideal composition of each rype for neutron scattering experiments and their relative sensitivity tae neutrons and γ-rays are considered. The ZnS type can be used with a γ-ray pulse shape discriminator and practical experience of its use in a multi-counter time-of-flight experiment is described. The Li glass has higher γ-background but also higher neutron efficiency. Performance figures of a scintillator containing 25% by wt. Li2O and 1 mm thick will be given. (author)

  15. Study on characteristics of Ladu counter

    International Nuclear Information System (INIS)

    The angular response, the radial differential response, the energy response and the distribution of neutron counting rate inside sphere cavity of the Ladu counter are measured, and the effective centre is estimated. The angular responses remain within 5%. The radial differential responses are consistent with those of solid spherical detector. Under the conditions that source distances are five times more than the radius of the counter, the error is less than 0.7% while the difference between effective centre and geometrical centre is ignored. Inside the sphere cavity, the ratio of ultra thermal neutron counting rate to thermal one is less than 10%, but the counting rates slightly depend on the position of thermal neutron detector. In the energy range from 200 eV to 5 MeV, the energy response values extend horizontally within +- 18%

  16. Recalibration of the Cameco mobile lung counter.

    Science.gov (United States)

    Kramer, Gary H; Hauck, Barry; Allen, Steve A

    2009-06-01

    The Cameco lung counter has been recalibrated using the Lawrence Livermore National Laboratory torso phantom using an extended lung set (i.e., longer than the original set). The previous calibration had used the Japanese Atomic Energy Research Institute torso phantom. The new calibration had lower counting efficiencies and, as a result, higher minimum detectable activities. The recalibrated Cameco lung counter was used to measure an extended lung set that had the volume reduced by using modified planar inserts for the sliced lungs as the extended lung set has a lung volume that is larger than Reference Man. This work has shown that sliced lungs can be used to alter the characteristics of the phantom's lung inserts substantially and provide flexibility in measurements previously not recognized. PMID:19430220

  17. Securitization and Counter-Securitization in Afghanistan

    OpenAIRE

    Stritzel, Holger; Chang, Sean C

    2015-01-01

    This article confronts securitization theory with the war in Afghanistan and thus explores questions and dynamics of securitization in a specific communicative situation of military combat. The confrontation highlights not only less well researched questions of implementation, resistance, legitimacy and difficulties of establishing authority in securitizations, but it also inspires a conceptualization of counter-securitization within the theory. In Afghanistan sovereign power to control and r...

  18. Reflexivity, social transformation, and counter culture

    OpenAIRE

    Cox, Laurence

    1997-01-01

    This paper attempts to identify how reflexivity works within the local rationalities of social movement milieux that, it is argued, represent an important source of the development of reflexivity in contemporary lifeworlds. In interviews in the Dublin counter culture, reflexivity appears above all as the institutionalisation of autonomy, the creation of new social forms for self-determined purposes. A starting point is strategies of distancing from the taken-for-granted assumptions of in...

  19. Reforms and counter-reforms in Bolivia

    OpenAIRE

    Jemio, Luis Carlos; Candia, Fernando; Evia, Jose Luis

    2009-01-01

    This paper analyzes reforms and counter-reforms in Bolivia in recent decades and their effects on the policymaking process (PMP) and productivity. Bolivia’s PMP has shifted from a formal representative democracy to a “participative and direct type of democracy” where street protest and other non-conventional forms of political participation have become dominant. While reforms have increased productivity, they have failed to secure the political support necessary to assure long-term sustainabi...

  20. Gunnislake Fish Counter Annual Report 2002

    OpenAIRE

    2003-01-01

    This is the Gunnislake Fish Counter Annual Report 2002 from the Environment Agency South West Region, which was held on March 2002. It presents the daily upstream counts of migratory salmonids recorded on the River Tamar at Gunnislake Weir fish counting station in 2002. The data within this report covers the period of the commercial migratory salmonid net buy-back scheme and the National Spring Salmon Bylaws. The report contains section on Net Buy-Back; Species Apportionment; Validation of co...

  1. Clearing over-the-counter derivatives

    OpenAIRE

    Ed Nosal

    2011-01-01

    Prior to the financial crisis of 2008, the over-the-counter derivatives market was not required to “clear” transactions. This changed with the signing of the new financial reform legislation, the Dodd–Frank Act on July 21, 2010. Going forward, most OTC derivatives will be cleared through a particular set of institutional arrangements: a regulated clearinghouse. This article provides an overview of how clearing works, the potential benefits of central clearing for OTC derivatives, and the opti...

  2. An ellipsoidal grid gas proportional scintillation counter

    OpenAIRE

    Silva, Rui M. C.; Santos, J. M. F. dos; Conde, C. A. N.

    1999-01-01

    Gas Proportional Scintillation Counters using curved grids for solid angle and reflection compensation have been described in the recent literature. They allow large radiation windows with diameters of 25 mm keeping at the same time the good energy resolutions characteristic of those X-ray detectors. However, the grids used have a spherical curvature, which does not correspond to the optimal curvature. In the present work we have calculated by computer simulation an improved shape for the cur...

  3. Use of silica aerogel in Cherenkov counters

    International Nuclear Information System (INIS)

    Silica aerogel has been widely used as a radiator for Cherenkov detectors. The review is devoted to the consideration of various aspects concerning aerogel: its production methods, optical and physical properties, including transparency, absorption, and scattering lengths, the number of photoelectrons and also factors affecting the accuracy of particle identification. The use of silica aerogel in various threshold Cherenkov counters as BELLE (KEK), TASSO (DESY), KEDR (VEPP-4M) is described

  4. Tests of a silica aerogel Cherenkov counter

    International Nuclear Information System (INIS)

    A Cherenkov counter with silica aerogel of refractive index 1.06 as radiator has been constructed and tested. The Cherenkov light produced in 9 cm thick silica aerogel was detected with four 5''-photomultipliers through a 162 cm long air light guide. The photoelectron yield for a 1 GeV/c pion beam was found to be 6 and uniform over a sensitive area of 40 x 30 cm2. (orig.)

  5. Protection of Human Rights in Countering Terrorism

    OpenAIRE

    Yu Nie

    2009-01-01

    Although the violent action occurred increasingly in the world, the definition of terrorism has not come into consensus yet. In countering terrorism, human right protection for the terrorist suspects should also be guaranteed, for the “fair” trial and the minimum procedural guarantees are the basic element of the rule of law. Moreover, the terrorist suspects should be protected by the minimum standard of the fair trial even if before the military commission. Because the minimum due process gu...

  6. The GlueX Start Counter

    Science.gov (United States)

    Pooser, Eric; GlueX Collaboration

    2015-04-01

    The GlueX experiment will study meson photoproduction with unprecedented precision. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H2 target. A Start Counter detector has been fabricated to identify the accelerator electron beam buckets, approximately 2 ns apart, and to provide accurate timing information which is used in the level-1 trigger of the experiment. This detector is designed to operate at photon intensities of up to 108 γ / s in the coherent peak and provide a timing resolution electron beam buckets to within 99 % accuracy. Furthermore, the Start Counter detector will provide excellent solid angle coverage, ~ 90 % of 4 π hermeticity , and a high degree of segmentation for background rejection. It consists of a cylindrical array of 30 scintillators with pointed ends that bend towards the beam at the downstream end. Silicon PhotoMultiplier (SiPM) detectors have been selected as the readout system. The physical properties of the Start Counter have been studied extensively. The results of theses studies are discussed. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics under Contracts DE-AC05-06OR23177 & DE-FG02-99ER41065.

  7. Which future for nuclear counter-proliferation?

    International Nuclear Information System (INIS)

    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

  8. Development of aerogel Cherenkov counters at Novosibirsk

    International Nuclear Information System (INIS)

    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

  9. Relativistic Static Thin Disks The Counter-Rotating Model

    CERN Document Server

    Espitia, O A; Espitia, Omar A.; Gonzalez, Guillermo A.

    2001-01-01

    A detailed study of the Counter-Rotating Model (CRM) for generic finite static axially symmetric thin disks with nonzero radial pressure is presented. We find a general constraint over the counter-rotating tangential velocities needed to cast the surface energy-momentum tensor of the disk as the superposition of two counter-rotating perfect fluids. We also found expressions for the energy density and pressure of the counter-rotating fluids. Then we shown that, in general, there is not possible to take the two counter-rotating fluids as circulating along geodesics neither take the two counter-rotating tangential velocities as equal and opposite. An specific example is studied where we obtain some CRM with well defined counter-rotating tangential velocities and stable against radial perturbations. The CRM obtained are in agree with the strong energy condition, but there are regions of the disks with negative energy density, in violation of the weak energy condition.

  10. 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.

  11. 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.

  12. 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.

  13. Geiger-Muller (GM) counters. Associated circuits and counting techniques

    International Nuclear Information System (INIS)

    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

  14. Cerenkov counter for the experiment NA3

    CERN Multimedia

    1978-01-01

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

  15. PRELIMINARY PROGRAMMED WHOLE—BODY COUNTER

    Institute of Scientific and Technical Information of China (English)

    张少东; 郑文忠; 等

    1995-01-01

    It is capable of giving the initial intakes of radionuclides and the assessment quantitites used in radiation protection according to its measured results of radionuclides in vivo.It is accomplished by providing the software of controlling,interface and internal dose estimation programs to the original iron cabin shielding whole-body counter.The preliminary application shows that its data processing is rapid and correct,and can meet the requirement of rapid internal radioactive contamination monitoring and diagnosing in case of lots of internal contamination subjects happened in nuclear accident.

  16. Taxing junk food to counter obesity.

    Science.gov (United States)

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

    2013-11-01

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

  17. Test of lead glass shower counters

    International Nuclear Information System (INIS)

    Lead glass counters made of wedge shaped blocks of SF6 were tested with positrons at SLAC. The beam energy ranged from 2 to 17.5 GeV. Energy dependence and beam position dependence of pulse height and energy resolution were studied with lead glass blocks of various lengths. The effect of a BK-7 light guide on pulse height was clearly observed. Degradation of the energy resolution due to aluminum absorbers of various lengths was investigated. A mesh type photomultiplier was also tested

  18. Neutron spectroscopy with the Spherical Proportional Counter

    OpenAIRE

    Bougamont, E .; Dastgheibi, A.; Derre, J.; Galan, J.; Gerbier, G.; Giomataris, I.; Gros, M.; Katsioulas, I.; Jourde, D.; Magnier, P.; Navick, X. F.; Papaevangelou, T.; Savvidis, I.; Tsiledakis, G.

    2015-01-01

    A novel large volume spherical proportional counter, recently developed, is used for neutron measurements. Gas mixtures of $N_{2}$ with $C_{2}H_{6}$ and pure $N_{2}$ are studied for thermal and fast neutron detection, providing a new way for the neutron spectroscopy. The neutrons are detected via the ${}^{14}N(n, p)C^{14}$ and ${}^{14}N(n, \\alpha)B^{11}$ reactions. Here we provide studies of the optimum gas mixture, the gas pressure and the most appropriate high voltage supply on the sensor o...

  19. Use of parallel counters for triggering

    Science.gov (United States)

    Nikityuk, N. M.

    1992-10-01

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

  20. Industrial espionage and technical surveillance counter measurers

    CERN Document Server

    Androulidakis, Iosif

    2016-01-01

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

  1. Cooperation in counter-pollution response

    International Nuclear Information System (INIS)

    This paper reports that counter-pollution arrangements in Europe are the object of an effective, dynamic, and highly organized international cooperation. The North sea area, in particular, is characterized by an impressive concentration of oil-combating equipment and by a high level of know-how. Though national policies with respect to spill management may still differ on many counts, governments are striving towards a harmonized approach of spill combating. Technically, the ability to prevent environmental damage in case of a large oil spill remains limited, but the European approach could be regarded as a valid attempt to mitigate damage, prevent chaos and limit the waste of valuable resources

  2. Improved proportional counters for practical applications

    International Nuclear Information System (INIS)

    Gas filled proportional counters are useful room-temperature X-ray detectors in various gauges and spectrometers. New gas mixtures have made it possible to improve the properties of these detectors. Penning mixtures offer some special advantages. These mixtures are formed when parent gas is diluted with a small amount of impurity whose ionization energy is lower than the lowest excited state of the parent atoms. The excitations of these atoms can subsequently be turned into ionizations. The result of this additional ionization is that the average ionization energy of the mixture falls below that of the pure gases. This also improves the energy resolution of the detector. Another feature of Penning mixtures is the fact that the first Townsend ionization coefficient is high. This in turn is reflected by an unusually low anode voltage required by the detector. This makes it possible to use high filling pressures and to realize the advantages such pressures offer: the achievement of good energy resolution with a commercial low noise preamplifier; a decrease in the background caused by the wall effect because of the subsequently shorter photoelectron traces; and an increase in the efficiency of the detector. The type of detector used in this paper is a sealed side window counter. Some of its properties, when filled with the mixtures Ar-C4H10, Ar-Xe, and Ne-Ar, are presented

  3. Instability patterns between counter-rotating disks

    Directory of Open Access Journals (Sweden)

    F. Moisy

    2003-01-01

    Full Text Available The instability patterns in the flow between counter-rotating disks (radius to height ratio R/h from 3.8 to 20.9 are investigated experimentally by means of visualization and Particle Image Velocimetry. We restrict ourselves to the situation where the boundary layers remain stable, focusing on the shear layer instability that occurs only in the counter-rotating regime. The associated pattern is a combination of a circular chain of vortices, as observed by Lopez et al. (2002 at low aspect ratio, surrounded by a set of spiral arms, first described by Gauthier et al. (2002 in the case of high aspect ratio. Stability curve and critical modes are measured for the whole range of aspect ratios. From the measurement of a local Reynolds number based on the shear layer thickness, evidence is given that a free shear layer instability, with only weak curvature effect, is responsible for the observed patterns. Accordingly, the number of vortices is shown to scale as the shear layer radius, which results from the competition between the centrifugal effects of each disk.

  4. Finding Feasible Abstract Counter-Examples

    Science.gov (United States)

    Pasareanu, Corina S.; Dwyer, Matthew B.; Visser, Willem; Clancy, Daniel (Technical Monitor)

    2002-01-01

    A strength of model checking is its ability to automate the detection of subtle system errors and produce traces that exhibit those errors. Given the high computational cost of model checking most researchers advocate the use of aggressive property-preserving abstractions. Unfortunately, the more aggressively a system is abstracted the more infeasible behavior it will have. Thus, while abstraction enables efficient model checking it also threatens the usefulness of model checking as a defect detection tool, since it may be difficult to determine whether a counter-example is feasible and hence worth developer time to analyze. We have explored several strategies for addressing this problem by extending an explicit-state model checker, Java PathFinder (JPF), to search for and analyze counter-examples in the presence of abstractions. We demonstrate that these techniques effectively preserve the defect detection ability of model checking in the presence of aggressive abstraction by applying them to check properties of several abstracted multi-threaded Java programs. These new capabilities are not specific to JPF and can be easily adapted to other model checking frameworks; we describe how this was done for the Bandera toolset.

  5. Neutron pileup algorithms for multiplicity counters

    Science.gov (United States)

    Robinson, Sean M.; Stave, Sean; Lintereur, Azaree; Siciliano, Edward; Kouzes, Richard; Bliss, Mary

    2015-06-01

    The shortage of helium-3 (3He) has created a need to identify alternative neutron detection options for a variety of nuclear nonproliferation applications. One application that may be affected by 3He replacement technology is that of mass accountancy for safeguards, which utilizes coincidence and multiplicity counters to verify special nuclear material declarations. The use of neutron scintillation materials, such as LiF-ZnS sheets, as an alternative to 3He proportional tubes in multiplicity counters requires novel techniques for Pulse Shape Discrimination to distinguish between neutrons and gamma rays. These techniques must work under high count rates, as the maximum momentary rate for incoming neutrons from multiplicity events can be quite large. We have created a fast and accurate neutron discrimination algorithm based on time window filtering and signature comparison that can operate quickly on data with high degrees of gamma ray and neutron pileup. This algorithm is evaluated for its capability to separate signals as the pileup rate increases, and the possibility for implementation on fast hardware (e.g., FPGA hardware) for real-time operation is explored.

  6. Over-the-counter Acne Treatments: A Review

    OpenAIRE

    Decker, Ashley; Graber, Emmy M.

    2012-01-01

    Acne is a common dermatological disorder that most frequently affects adolescents; however, individuals may be affected at all ages. Many people who suffer from acne seek treatment from both prescription and over-the-counter acne medications. Due to convenience, lower cost, and difficulty getting an appointment with a dermatologist, the use of over-the-counter acne treatments is on the rise. As the plethora of over-the-counter acne treatment options can be overwhelming, it is important that d...

  7. Wind tunnel tests of stratospheric airship counter rotating propellers

    OpenAIRE

    Yaxi Chen; Peiqing Liu; Zhihao Tang; Hao Guo

    2015-01-01

    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...

  8. Particle Counter Determination of Bacterial Biomass in Seawater

    OpenAIRE

    Kogure, Kazuhiro; Koike, Isao

    1987-01-01

    The applicability of the Elzone particle counter to the determination of marine bacterial biomass was investigated. The biomass of bacterial pure cultures and a mixed natural population were followed by using the particle counter, a CHN analyzer, and an ATP analyzer. The particle counter showed the precise size distribution of number and volume of submicron-size particles in seawater. For the pure cultured bacterial strains, the conversion factor from volume to carbon is 0.209 mg of C per mm3...

  9. Investigation of new gas mixtures for the Pestov Counter

    CERN Document Server

    Sann, H; CERN. Geneva; Eschke, J; Lühning, J; Lynen, U; Neyer, C; Pestov, Yu N; Schmidt, H R; Schreiber, B M; Schulze, R; Stelzer, H; Woerner, A; Frankenfeld, U

    2000-01-01

    The physical principle of discharge localization in Pestor spark counters is described. It was experimentally shown that Isoprene is one of the promising candidates to replace 1,3-Butadiene in the standard gas mixture. In the spark counter with the DME-Argon gas mixture and an aluminium nitrite cathode a discharge localization was obtained for the first time. This result is considered as the beginning of a new spark counter technology without conditioning.

  10. Threshold aerogel Cherenkov counters of the KEDR detector

    International Nuclear Information System (INIS)

    Particle identification system based on aerogel threshold Cherenkov counters ASHIPH (Aerogel SHifter PHotomultiplier) was installed in the KEDR detector in 2013. The system consists of 160 counters arranged in two layers and contains 1000 liters of aerogel with refractive index of 1.05 and 160 MCP PMTs with multialkali photocathode. The efficiency of relativistic particles detection was measured. Long-term stability of ASHIPH counters was studied. The main reasons of efficiency degradation are presented

  11. Development of tecniques for constructing Geiger-Mueller counters

    International Nuclear Information System (INIS)

    A systematic study of several construction techniques of Geiger-Mueller counters was carried out in order to establish the most suitable technology for such purpose. The results obtained with counters for alpha, beta and gamma rays, which were designed and built in the laboratory of Sao Paulo University (USP) are described. Most of the counters were built inside Pyrex-glass envelope and their cathodes were made of electrolytic copper or brass foils of still a silver layer deposited by chemical process. Some counters were made with cilyndrical brass tube. Anode wires of different materials and diameters and severals quenching vapors were used and the results obtained are described. All the procedures used in preparation of surfaces, cleaning of materials, purification of filling mixtures, the procedures for operating evacuation and filling of counters are described. The results obtained with self quenching counters using soda glass and an external colloidas graphite cathode are presented and the influence of filling mixtures is analysed. A technology to produce reliable counters from materials and gases easily available in the country was established. It is shown that counters with an external cathode can be used when recovery time on order of 2 μs are required. The plateus obtained for such counters were on order of 1000V with slope of about 0.5%. (Author)

  12. Discharge quenching circuit for Geiger-Mueller counters

    International Nuclear Information System (INIS)

    Electron discharge quenching circuit in halogen Geiger-Mueller counters with the total time of counter supply switch on after the signal appearence at the input of approximately 70 ns at input sensitivity of approximately 50 mV is described. The circuit provides the parallel control of five STS-5 counters at the quenching pulse duration of 4.5 μs. For two STS-5 counters the counting characteristics with the inclination up to 0.131%/V and flat-top of 100 V at the load of 60 thousand pulse/s. Maximum loading is 120 thousand pulse/s

  13. Relativistic Static Thin Disks: The Counter-Rotating Model

    OpenAIRE

    Espitia, Omar A.; Gonzalez, Guillermo A.

    2001-01-01

    A detailed study of the Counter-Rotating Model (CRM) for generic finite static axially symmetric thin disks with nonzero radial pressure is presented. We find a general constraint over the counter-rotating tangential velocities needed to cast the surface energy-momentum tensor of the disk as the superposition of two counter-rotating perfect fluids. We also found expressions for the energy density and pressure of the counter-rotating fluids. Then we shown that, in general, there is not possibl...

  14. 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.

  15. Neutron dosimetry using proportional counters with tissue equivalent walls

    International Nuclear Information System (INIS)

    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)

  16. Influence of guard wires in the response of spark counters

    International Nuclear Information System (INIS)

    A systematic study of the operation characteristics of Spark Counters with air filling at atmospheric pressure, was carried out for alpha particles (241 Am). Anode wires of different chemical compositions and diameters were used. The influence of guard wires in the efficiency of the counter has improved its efficiency by 25%. The properties of these counters such as very low background, high efficiency of detection foir heavily ionizing particles, their directional propertiesd and their negligible efficiency for beta and gamma radiation show that they can be used with great advantage over conventional counters in several Nuclear Physics problems. (author). 14 refs, 10 figs

  17. Absolute calibration of TFTR helium proportional counters

    International Nuclear Information System (INIS)

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

  18. Fast-neutron coincidence-counter manual

    International Nuclear Information System (INIS)

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

  19. Test of a ring imaging Cherenkov counter

    International Nuclear Information System (INIS)

    We have tested a ring imaging Cherenkov counter with readout of the projection chamber type. A specific detector response of N0=80 cm-1 was measured which corresponds to 8 photoelectrons per event in a 1.60 m long nitrogen radiator. The resolution of the ring radius was measured to be Δr/r=3.6%. The crosstalk between neighboring wires due to photons generated in the avalanche process was estimated to contribute up to 50% per hit. It was reduced considerably by inserting shielding walls between the wires and by adding C2H6 or iC4H10 to the CH4-TMAE gas mixture. (orig.)

  20. EFFECT OF COUNTERS IN PERFORMANCE OF HADOOP

    Directory of Open Access Journals (Sweden)

    Preeti Jain

    2015-10-01

    Full Text Available Recent technological advancements have led to an overflow of data from distinctive domains (e.g., health care and scientific sensors, user-generated data, Internet and financial companies, and supply chain systems over the past two decades [1]. Big data is commonly unstructured, huge in volume and require more real-time analysis. This paper discusses a Big Data problem from NCDC for huge volume of weather data collected from various parts of world. We had generated map ( and reduce ( function for solving this problem and experimental results of these applications on a Hadoop cluster are being discussed. In this paper, performance of above application has been shown with respect to some counters available.

  1. A single-electron counter for nanodosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Breskin, A.; Chechik, R.; Pansky, A.; Shchemelinin, S. [Weizmann Inst. of Science, Rehovot (Israel). Dept. of Particle Physics; Colautti, P.; Conte, V.; De Nardo, L.; Talpo, G. [Istituto Nazionale di Fisica Nucleare, Legnaro (Italy); Tornielli, G. [Istituto Nazionale di Fisica Nucleare, Padua (Italy)

    1995-12-31

    A detector has been devised able to measure with high resolution the primary ionisation yield in tissue-equivalent gas volumes of a few nanometers equivalent length. The sensitive ionisation volume is a wall-less millimetric region defined by a properly shaped electric field. Free electrons created by the radiation inside the sensitive volume are collected into an electron multiplier, capable of efficiently counting single electrons at low gas pressure. The single-electron detection system consists of a long drift column attached to a multistep proportional counter. The electron cloud created by the radiation inside the sensitive volume, diffuses along the drift column. Single electrons, successively arriving at the multiplier are amplified, giving rise to a pulse trail from which the original number of ionisation electrons is counted. The experimental set-up, the electron counting principle, and first data are presented and discussed. (author).

  2. A single-electron counter for nanodosimetry

    International Nuclear Information System (INIS)

    A detector has been devised able to measure with high resolution the primary ionisation yield in tissue-equivalent gas volumes of a few nanometers equivalent length. The sensitive ionisation volume is a wall-less millimetric region defined by a properly shaped electric field. Free electrons created by the radiation inside the sensitive volume are collected into an electron multiplier, capable of efficiently counting single electrons at low gas pressure. The single-electron detection system consists of a long drift column attached to a multistep proportional counter. The electron cloud created by the radiation inside the sensitive volume, diffuses along the drift column. Single electrons, successively arriving at the multiplier are amplified, giving rise to a pulse trail from which the original number of ionisation electrons is counted. The experimental set-up, the electron counting principle, and first data are presented and discussed. (author)

  3. Fluctuation phenomena in the proportional counter

    International Nuclear Information System (INIS)

    Fluctuations in the number of electron-ion pairs produced in the primary ionization and in the size of the subsequent electron avalanche, can be reduced by improving the efficiency of the ionization mechanisms by the Penning effect. Energy spent exciting metastable states is used to increase the ionization yield by introducing a second gas whose first ionization potential is slightly lower than the first metastable level of the main gas. A proportional counter filled with a range of Penning mixtures has been investigated experimentally. The Penning mixture argon-xenon gives an increased resolution over argon-methane. For fundamental studies of avalanche fluctuations in Penning mixtures, a uniform field chamber has been constructed. Experimental studies of f (the relative variance of the avalanche size) are compared with values predicted by various avalanche models. The results are reasonably close to predictions based on experimental measurements of ionization probability. (U.K.)

  4. An over-the-counter omission.

    Science.gov (United States)

    Scheurer, Danielle Bowen

    2006-09-01

    Despite the widespread use of over-the-counter (OTC) medications, their utilization is rarely ascertained at hospital admission. Presented here is an interesting case of acute renal failure and hemolytic anemia attributable to a commonly utilized OTC medication. The chronic use of phenazopyridine accounted for all of these findings. Upon discontinuation, everything normalized within one month. Although the differential diagnosis for renal failure and hemolytic anemia is extensive, scleral icterus, normal bilirubin, and orange-colored urine raised the suspicion of phenazopyridine use. This case report highlights overuse of common OTC medications, as well as a lack of knowledge of potential adverse reactions. With history-taking vigilance and patient education, adverse events from OTC medications can be minimized. PMID:17004539

  5. Modelling of an IR scintillation counter

    CERN Document Server

    Fraga, M M F; Policarpo, Armando

    2000-01-01

    A systematic study of the excitation and de-excitation mechanisms in ternary gas mixtures Ar+CO sub 2 +N sub 2 is presented regarding the possibility of developing a proportional scintillation counter based on the detection of the infrared molecular emissions associated with the lowest vibrational states of molecules. The use of visible or near-infrared photons (lambda<1 mu m) for applications like imaging and quality control of microstructure detectors has been reported. In view of these applications we analyse the processes leading to near-infrared emissions in pure argon and give an estimation of the number of photons emitted per electron, at several pressures, as a function of the charge gain.

  6. Bragg Curve Counter for primary beam monitor

    International Nuclear Information System (INIS)

    The prototype Bragg Curve Counter (BCC) has been tested by α-source (241Am) with a continuous gas flow system (P-10: 90% Ar+10% CH4, at 300Torr). Two types of the Frisch grid were prepared for the BCC. One was made of expanded metal meshes, which consist of 175 meshes/inch2 with a 100μmt nickel sheet. The other was made of a 1mm pitch wire with φ 50 μm of the tungsten. The shape of Bragg peak signal was compared each other. It was found that the energy spectrum obtained by the wire grid is a little sharper than that obtained by the meshes grid. However the meshes grid is superior than the wire grid so far as handling and durability are concerned. (author)

  7. Air-ion counter and mobility spectrometer

    International Nuclear Information System (INIS)

    Mono-electrode self “zeroing” air-ion counter and mobility (size) scanning spectrometer (CDI-011) based on the Gerdien aspirated condenser principle has been developed. Instrument is intended for short- and long-term indoor and outdoor air-ion concentration measurements and scanning of air-ions by mobility. Measuring small currents (typically 10−14 A) generated by the air-ions in outdoor conditions is demanding and causes many problems related to change of temperature, relative humidity, wind and electromagnetic noise. Also, measuring of both ion polarities with mono electrode detector require alternate changes of the polarizing voltage sign which produces capacitive current spikes. Various techniques, including “zeroing” method, have been applied to successfully overcome most of these measuring interferences.

  8. Air-ion counter and mobility spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Kolarz, Predrag, E-mail: kolarz@ipb.ac.rs [Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Belgrade (Serbia); Miljkovic, Budimir [Merni Instrumenti D.O.O., Ljube Stojanovica 38, 11000 Belgrade (Serbia); Curguz, Zoran [Faculty of Transport and Traffic Engineering, University of East Sarajevo, Vojvode Misica 52, 74000 Doboj (Bosnia and Herzegowina)

    2012-05-15

    Mono-electrode self 'zeroing' air-ion counter and mobility (size) scanning spectrometer (CDI-011) based on the Gerdien aspirated condenser principle has been developed. Instrument is intended for short- and long-term indoor and outdoor air-ion concentration measurements and scanning of air-ions by mobility. Measuring small currents (typically 10{sup -14} A) generated by the air-ions in outdoor conditions is demanding and causes many problems related to change of temperature, relative humidity, wind and electromagnetic noise. Also, measuring of both ion polarities with mono electrode detector require alternate changes of the polarizing voltage sign which produces capacitive current spikes. Various techniques, including 'zeroing' method, have been applied to successfully overcome most of these measuring interferences.

  9. Efficiency measurement for solid track spark auto counters

    International Nuclear Information System (INIS)

    The theory of solid track spark auto counters was introduced. The best etch condition was explored. Efficiency for spark auto counters was measured. The ameliorating-factor for the hull's thickness and etch-thickness was measured. The measurement for ameliorating factors and efficiency makes solid track detect system, can be used for absolute fission rate measurement. (authors)

  10. 21 CFR 892.1130 - Nuclear whole body counter.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nuclear whole body counter. 892.1130 Section 892.1130 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1130 Nuclear whole body counter....

  11. Majorizational Choosing of SeveralDifferent Fuzzy Counter Operator

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Different fuzzy reasoning methods were made by choosing different fuzzy operater. This article generally introduced the basic structure of fuzzy controller ,and gave several different fuzzy controllers ,and compared and analyzed different fuzzy counters in theory and computer simulating control and realized majorizational choosing of several fuzzy counters.

  12. Automatic calibration system for VENUS lead glass counters

    International Nuclear Information System (INIS)

    Automatic calibration system for VENUS lead glass counters has been constructed. It consists of a moving table, position sensors, control electronics and a master minicomputer, (micro-11 of DEC). The system has been well operated for six months and one third of VENUS lead glass counters have been calibrated. (author)

  13. 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 religion,…

  14. Test of TOF Scintillator Counters for ALICE Detector

    CERN Document Server

    Semenov, P; Malakhov, A; Melkumov, G L

    1996-01-01

    The manufactured counters of the fast response scintillators with the photomultipliers valid for operation in the magnetic field environment is being considered among the options for the time-of-flight (TOF) measurements as a particle identification tool for the ALICE experiment. Here we discuss how the tests of such counters have been implemented on the particle beam in respect to the time resolution.

  15. Investigation of sampling tubes of end-cap shower counter

    International Nuclear Information System (INIS)

    The measurement and investigation were conducted for the performances of sampling tubes of end-cap shower counter in BES. It is shown that the self-quenching streamer tube with 12.8 x 12.8 (1 + 2 + 1) is suitable for end-cap shower counter

  16. Recent results on aerogel development for use in Cherenkov counters

    CERN Document Server

    Danilyuk, A F; Savelieva, M D; Bobrovnikov, V S; Buzykaev, A R; Kravchenko, E A; Lavrov, A V; Onuchin, A P

    2002-01-01

    Synthesis of silica aerogel for Cherenkov counters is being studied for more than 10 years at the Boreskov Institute of Catalysis in collaboration with the Budker Institute of Nuclear Physics. Index of refraction, light scattering length and light absorption length are optical characteristics which determine the quality of aerogel Cherenkov counter. These parameters were measured for the aerogel produced. The results are presented.

  17. High pressure proportional counters operating in pure hydrogen

    International Nuclear Information System (INIS)

    Construction and operation of high pressure proportional counters designed for pressures up to 92 atm which work in pure hydrogen are described. This type of counter offering track reconstruction as well as energy loss determination will be employed as live-target for low-energy recoil measurements in elastic np scattering. (Auth.)

  18. Electrovacuum Static Counter-Rotating Relativistic Dust Disks

    CERN Document Server

    González, G A

    2002-01-01

    A detailed study of the Counter-Rotating Model (CRM) for generic electrostatic (magnetostatic) axially symmetric thin disks without radial pressure is presented. We find a general constraint over the counter-rotating tangential velocities needed to cast the surface energy-momentum tensor of the disk as the superposition of two counter-rotating charged dust fluids. We then show that this constraint is satisfied if we take the two counter-rotating streams as circulating along electrogeodesics with equal and opposite tangential velocities. We also find explicit expressions for the energy densities, electrostatic (magnetostatic) charge densities and velocities of the counter-rotating fluids. Three specific examples are considered where we obtain some CRM well behaved based in simple solutions to the Einstein-Maxwell equations. The considered solutions are Reissner-Nordstrom in the electrostatic case, its magnetostatic counterpart and two solutions obtained from Taub-NUT and Kerr solutions.

  19. DESIGN OF TERNARY COUNTER BASED ON ADIABATIC DOMINO CIRCUIT

    Institute of Scientific and Technical Information of China (English)

    Yang Qiankun; Wang Pengjun; Zheng Xuesong

    2013-01-01

    By researching the ternary counter and low power circuit design method,a novel design of low power ternary Domino counter on switch-level is proposed.Firstly,the switch-level structure expression of ternary loop operation circuit with enable pin is derived according to the switch-signal theory,and the one bit ternary counter is obtained combining the ternary adiabatic Domino literal operation circuit and buffer.Then the switch-level structure expression of enable signal circuit is derived,and the four bits ternary counter is obtained by cascade connection.Finally,the circuit is simulated by Spice tool and the output waveforms transform in proper order indicating that the logic function is correct.The energy consumption of the four bits ternary adiabatic Domino counter is 63% less than the conventional Domino counterpart.

  20. Counter-Rotating Tandem Motor Drilling System

    Energy Technology Data Exchange (ETDEWEB)

    Kent Perry

    2009-04-30

    Gas Technology Institute (GTI), in partnership with Dennis Tool Company (DTC), has worked to develop an advanced drill bit system to be used with microhole drilling assemblies. One of the main objectives of this project was to utilize new and existing coiled tubing and slimhole drilling technologies to develop Microhole Technology (MHT) so as to make significant reductions in the cost of E&P down to 5000 feet in wellbores as small as 3.5 inches in diameter. This new technology was developed to work toward the DOE's goal of enabling domestic shallow oil and gas wells to be drilled inexpensively compared to wells drilled utilizing conventional drilling practices. Overall drilling costs can be lowered by drilling a well as quickly as possible. For this reason, a high drilling rate of penetration is always desired. In general, high drilling rates of penetration (ROP) can be achieved by increasing the weight on bit and increasing the rotary speed of the bit. As the weight on bit is increased, the cutting inserts penetrate deeper into the rock, resulting in a deeper depth of cut. As the depth of cut increases, the amount of torque required to turn the bit also increases. The Counter-Rotating Tandem Motor Drilling System (CRTMDS) was planned to achieve high rate of penetration (ROP) resulting in the reduction of the drilling cost. The system includes two counter-rotating cutter systems to reduce or eliminate the reactive torque the drillpipe or coiled tubing must resist. This would allow the application of maximum weight-on-bit and rotational velocities that a coiled tubing drilling unit is capable of delivering. Several variations of the CRTDMS were designed, manufactured and tested. The original tests failed leading to design modifications. Two versions of the modified system were tested and showed that the concept is both positive and practical; however, the tests showed that for the system to be robust and durable, borehole diameter should be substantially larger

  1. Counter-terrorism threat prediction architecture

    Science.gov (United States)

    Lehman, Lynn A.; Krause, Lee S.

    2004-09-01

    This paper will evaluate the feasibility of constructing a system to support intelligence analysts engaged in counter-terrorism. It will discuss the use of emerging techniques to evaluate a large-scale threat data repository (or Infosphere) and comparing analyst developed models to identify and discover potential threat-related activity with a uncertainty metric used to evaluate the threat. This system will also employ the use of psychological (or intent) modeling to incorporate combatant (i.e. terrorist) beliefs and intent. The paper will explore the feasibility of constructing a hetero-hierarchical (a hierarchy of more than one kind or type characterized by loose connection/feedback among elements of the hierarchy) agent based framework or "family of agents" to support "evidence retrieval" defined as combing, or searching the threat data repository and returning information with an uncertainty metric. The counter-terrorism threat prediction architecture will be guided by a series of models, constructed to represent threat operational objectives, potential targets, or terrorist objectives. The approach would compare model representations against information retrieved by the agent family to isolate or identify patterns that match within reasonable measures of proximity. The central areas of discussion will be the construction of an agent framework to search the available threat related information repository, evaluation of results against models that will represent the cultural foundations, mindset, sociology and emotional drive of typical threat combatants (i.e. the mind and objectives of a terrorist), and the development of evaluation techniques to compare result sets with the models representing threat behavior and threat targets. The applicability of concepts surrounding Modeling Field Theory (MFT) will be discussed as the basis of this research into development of proximity measures between the models and result sets and to provide feedback in support of model

  2. Effect of Counter Electrode in Electroformation of Giant Vesicles

    Directory of Open Access Journals (Sweden)

    Shuuhei Oana

    2011-11-01

    Full Text Available Electroformation of cell-sized lipid membrane vesicles (giant vesicles, GVs, from egg yolk phosphatidylcholine, was examined varying the shape of the counter electrode. Instead of a planar ITO (indium tin oxide electrode commonly used, platinum wire mesh was employed as a counter electrode facing lipid deposit on a planar formation electrode. The modification did not significantly alter GV formation, and many GVs of 30–50 µm, some as large as 100 µm, formed as with the standard setup, indicating that a counter electrode does not have to be a complete plane. When the counter electrode was reduced to a set of two parallel platinum wires, GV formation deteriorated. Some GVs formed, but only in close proximity to the counter electrode. Lower electric voltage with this setup no longer yielded GVs. Instead, a large onion-like multilamellar structure was observed. The deteriorated GV formation and the formation of a multilamellar structure seemed to indicate the weakened effect of the electric field on lipid deposit due to insufficient coverage with a small counter electrode. Irregular membranous objects formed by spontaneous swelling of lipid without electric voltage gradually turned into multilamellar structure upon following application of voltage. No particular enhancement of GV formation was observed when lipid deposit on a wire formation electrode was used in combination with a large planar counter electrode.

  3. A dual-detector extended range rem-counter

    CERN Document Server

    Ferrarini, M; Silari, M; Agosteo, S

    2010-01-01

    The design and characterization of a dual-detector spherical rem counter is discussed in this paper. The rem counter is based on a polythene sphere with lead and cadmium insets, designed to host at its centre either an active (He-3 SP9 proportional counter) or a passive (CR39 + B-10 radiator) thermal neutron detector. Its sensitivity ranges from thermal energies up to 1 GeV. A Monte Carlo characterization of this dual-detector rem counter has shown no significant change in the shape of the response curve obtained with the two detectors. The rem counter has been calibrated with a Pu-Be source. An intercomparison in a high-energy neutron field has been carried out at the CERF facility at CERN among the rem counter in the two configurations, two commercial units and the original version of the active LINUS in use at CERN. Both the active and passive versions of the rem counter agree, within the statistical uncertainties, with the CERN LINUS and with the facility reference values. Both versions of the instrument ...

  4. A method for optimising the gas replacing period of sealed proportional counter

    International Nuclear Information System (INIS)

    Proportional counter can be used as low-energy particles detector because of its gas gain. According to charging manner, proportional counter can be divided into sealed and gas-flow proportional counters. Compared with gas-flow counter, although sealed proportional counter can be operated simply but it is short-lived, needs to replace the sealed gas periodically. It introduces the aging phenomenon of sealed proportional counter and a method for optimising the gas replacing period. (authors)

  5. Training options for countering nuclear smuggling

    Energy Technology Data Exchange (ETDEWEB)

    Ball, D Y; Erickson, S A

    1999-07-01

    The burden of stopping a nuclear smuggling attempt at the border rests most heavily on the front-line customs inspector. He needs to know how to use the technological tools at his disposal, how to discern tell-tale anomalies in export documents and manifests, how to notice psychological signs of a smuggler's tension, and how to search anything that might hide nuclear material. This means that assistance in the counter-nuclear smuggling training of customs officers is one of the most critical areas of help that the United States can provide. This paper discusses the various modes of specialized training, both in the field and in courses, as well as the types of assistance that can be provided. Training for nuclear customs specialists, and supervisors and managers of nuclear smuggling detection systems is also important, and differs from front-line inspector training in several aspects. The limitations of training and technological tools such as expert centers that will overcome these limitations are also discussed. Training assistance planned by DOE/NN-43 to Russia within the Second Line of Defense program is discussed in the light of these options, and future possibilities for such training are projected.

  6. Training options for countering nuclear smuggling

    International Nuclear Information System (INIS)

    The burden of stopping a nuclear smuggling attempt at the border rests most heavily on the front-line customs inspector. He needs to know how to use the technological tools at his disposal, how to discern tell-tale anomalies in export documents and manifests, how to notice psychological signs of a smuggler's tension, and how to search anything that might hide nuclear material. This means that assistance in the counter-nuclear smuggling training of customs officers is one of the most critical areas of help that the United States can provide. This paper discusses the various modes of specialized training, both in the field and in courses, as well as the types of assistance that can be provided. Training for nuclear customs specialists, and supervisors and managers of nuclear smuggling detection systems is also important, and differs from front-line inspector training in several aspects. The limitations of training and technological tools such as expert centers that will overcome these limitations are also discussed. Training assistance planned by DOE/NN-43 to Russia within the Second Line of Defense program is discussed in the light of these options, and future possibilities for such training are projected

  7. An ellipsoidal grid gas proportional scintillation counter

    International Nuclear Information System (INIS)

    Gas Proportional Scintillation Counters using curved grids for solid angle and reflection compensation have been described in the recent literature. They allow large radiation windows with diameters of 25 mm keeping at the same time the good energy resolutions characteristic of those X-ray detectors. However, the grids used have a spherical curvature, which does not correspond to the optimal curvature. In the present work we have calculated by computer simulation an improved shape for the curved grid. This shape can be well fitted to an ellipsoid of revolution, with a large eccentricity. A detector was designed with such an ellipsoidal grid and a radiation window 40 mm in diameter, filled with pure xenon at 927 Torr coupled to an EMI D676QB VUV photomultiplier tube having a 2'' diameter window. For the experiments envisaged, detection of solar X-rays in the 20-80 keV energy range, a 7 cm thick drift region was used, leading to efficiencies from 80% to 20%, respectively. Such a thick drift region reduces the performance mainly for soft X-rays. For 22 keV X-rays the energy resolution obtained, for a broad X-ray beam entering the full 40 mm diameter detector window, is 6.0%. Results are presented showing the variation of the energy resolution with the window diameter and a performance, for ellipsoidal grids superior to that for spherical grids. A discussion of the results obtained is presented

  8. The GlueX Start Counter

    Science.gov (United States)

    Pooser, Eric; GlueX Collaboration

    2013-10-01

    The GlueX experiment will be one of the largest photo-production facilities in the world and is currently under construction. This experiment will use the coherent bremsstrahlung technique to produce a 9 GeV linearly polarized photon beam incident on a liquid H2 target. A Start Counter detector has been designed to identify the accelerator electron beam buckets, approximately 2 ns apart, and to provide accurate timing information. It is now under construction at Florida International University (FIU). This detector is designed to operate at photon intensities of up to 108 γ /s in the coherent peak. It consists of an array of 30 individual scintillators with ``pointed'' ends that bend toward the beam at the downstream end. SiPM detectors, which comprise the readout system, are placed as close as possible at the end of each scintillator. The EJ-200 scintillator is best suited for the timing studies with a fast decay time of 2.0 ns. The physical properties of the scintillators, configured to the desired geometry, have been studied extensively at FIU. Geant4 simulations are currently underway to replicate and to understand our experimental results. The results of these timing studies and simulations are discussed.

  9. Development of Laser-Based Handheld Aerosol Particle Counter

    Institute of Scientific and Technical Information of China (English)

    CHEN Chang; LI Hui

    2005-01-01

    The JC-CA300 handheld Aerosol particle counter is designed and developed based on light scattering principle. The JC-CA300 counter is composed of optical sensor, DSP component and microprocessor unit. The hardware architecture is designed in compact style by SMT IC chips. The whole counter weight is less than 2 pounds. With 32K RAM space, the JC-CA300 can store 500 sampling records and support standard printer and communicate with a computer through RS232 interface. Based on experimental results, the main performance of JC-CA300 is better than that of the ARTI'S HHPC-6 instrument.

  10. The Application of Counter-Rotating Turbine in Rocket Turbopump

    Directory of Open Access Journals (Sweden)

    Tang Fei

    2008-01-01

    Full Text Available Counter rotating turbine offers advantages on weight, volume, efficiency, and maneuverability relative to the conventional turbine because of its special architecture. Nowadays, it has been a worldwide research emphasis and has been used widely in the aeronautic field, while its application in the astronautic field is seldom investigated. Researches of counter rotating turbine for rocket turbopump are reviewed in this paper. A primary analysis of a vaneless counter rotating-turbine configuration with rotors of different diameters and rotational speeds is presented. This unconventional configuration meets the requirements of turbopump and may benefit the performance and reliability of rocket engines.

  11. Basic characteristics of gas counters for heavy ion nuclear reactions

    International Nuclear Information System (INIS)

    To reveal basic characteristics of gas counters for heavy ion nuclear reactions, a ΔE - E telescope and a parallel plate avalanche counter, operating at low gas pressures of 241Am α source. For the telescope, the intrinsic resolution of ΔE and the energy loss straggling, associated with gas pressure, were obtained and compared with the calculated values by Tschalaer's theory. For the avalanche counter with the electrodes consisting of 30 μg / cm2 polypropylene stretched film, a time resolution of 170 ps and a position resolution of 0.5 mm were obtained. (author)

  12. Threshold gas 32-channel Cherenkov counter of the EXCHARM spectrometer

    International Nuclear Information System (INIS)

    A 32-channel threshold gas Cherenkov counter with 420 cm air radiator at atmospheric pressure is described. Spherical mirrors with curvature radius of 214 cm and FEU-125, FEU-49B photomultipliers are used in the counter for collection and detection of the Cherenkov radiation. The input windows of the photomultipliers are coated with a shifter of the light spectrum. The detection efficiency of charged particles at a plateau of the threshold characteristic (β ≥ 0,99984) exceeds 97%. The counter is a part of the identification system of the EXCHARM spectrometer. 6 refs., 6 figs., 1 tab

  13. A general model for the gain of gas avalanche counters

    International Nuclear Information System (INIS)

    A simple, general model of the avalanche process in gas counters is described. Applicable to all the common forms of gas avalanche detector - wire, microstrip, point anode and parallel gap, the model describes the gain process in terms of two pseudo-physical constants which are effectively invariant over the working range of any given detector configuration. For counter operation over a wide range of conditions (e.g. very different gas pressures) the model is extended so that four parameters are required to model the gain. Applications of the model to the characterisation, operation and design of a variety of counter types are given. (author)

  14. Gain stabilisation of gas-flow proportional counters

    International Nuclear Information System (INIS)

    A stabilisation of the gas gain for proportional counters with a continuous gas flow is described. New gas-flow systems for two end-window counters and one pressurised proportional counter were developed. The gas density of the counting-gas flow is stabilised by a two-stage back-pressure regulation system. The pressure in the gas flow is compared with the pressure in a reference vessel. During one month of operation the gain was stable within ±0.3%

  15. Countering the ‘Natural’ Organizational Self on Social Media

    DEFF Research Database (Denmark)

    Johansen, Trine Susanne

    2016-01-01

    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......, 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...

  16. 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.

  17. Use of silica aerogel for Cherenkov radiation counter

    CERN Document Server

    Bourdinaud, M; Thévenin, J C

    1976-01-01

    The Cherenkov light collection from silica aerogel has been studied in two types of counters. In the first counter a mirror was used to collect the light and in the latter a diffusing box surrounded the aerogel sample. The optical characteristics of the aerogel (refractive index 1.06) and the diffusion coefficients of different diffusing materials have been measured. It is thus possible to build Cherenkov counters with silica aerogel for a high energy physics experiment at the CERN Intersecting Storage Rings. (4 refs).

  18. Use of silica aerogel for Cherenkov radiation counter

    International Nuclear Information System (INIS)

    The Cherenkov light collection from silica aerogel has been studied in two types of counters. In the first counter a mirror was used to collect the light and in the latter a diffusing box surrounded the aerogel sample. The optical characteristics of the aerogel (refractive index 1.06) and the diffusion coefficients of different diffusing materials have been measured. It is thus possible to build Cherenkov counters with silica aerogel for a high energy physics experiment at the CERN Intersecting Storage Rings. (Auth.)

  19. Bathroom Buddies: Countering your Clockwise Rotation

    Science.gov (United States)

    Cooper, C. M.; Stegman, D. R.

    2006-12-01

    Which way does your bathtub, toilet, sink, or other favorite plumbing basin drain? Popular television shows perpetuate the fact that water spins the opposite direction in the southern hemisphere, and sometimes even explicitly point to the Coriolis effect (or Earth's rotation) as the cause. Skeptics disagree: "No way. Water doesn't obey your rules: it goes where it wants...like me, babe." [1]. Fact: Cyclones rotate clockwise in the southern hemisphere and hurricanes counter-clockwise in the northern hemisphere. But does your hemisphere also determine the direction water spirals down your toilet? In the ideal scenario of water draining out a sink (i.e. a defect-free, perfectly-leveled basin in which water has remained undisturbed for sufficient enough time to quiet any background motions or eddies) --- then yes, maybe it is possible. However, in everyday life, not even the most decadent of bathtubs provide us a large enough lengthscale to observe the Coriolis effect on the direction which water spirals towards the drain. Thus, we are left confronting the possibility that something heard on television isn't true. But is just "telling" students, friends, or strangers in bars enough to debunk this urban myth? Rather, we offer a practical demonstration involving a friend from the opposite hemisphere (if not one in existence, then find one on the internet!), a bathroom, a funnel, a bucket, some food coloring, a camera, a pitcher and some equations and scalings for extra credit and fun. 1) Simpson, B., "Bart vs. Australia", Season 6, Episode 119, 1995.

  20. 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...

  1. On fitting planetary systems in counter-revolving configurations

    CERN Document Server

    Gayon-Markt, Julie

    2009-01-01

    In Gayon & Bois (2008) and Gayon etal (2009), (i) we studied the theoretical feasibility and efficiency of retrograde mean motion resonances (i.e. two planets are both in orbital resonance and in counter-revolving configuration), (ii) we showed that retrograde resonances can generate interesting mechanisms of stability, and (iii) we obtained a dynamical fit involving a counter-revolving configuration that is consistent with the observations of the HD73526 planetary system. In the present paper, we present and analyze data reductions assuming counter-revolving configurations for eight compact multi-planetary systems detected through the radial velocity method. In each case, we select the best fit leading to a dynamically stable solution. The resulting data reductions obtained in rms and chi values for counter-revolving configurations are of the same order, and sometimes slightly better, than for prograde configurations. In the end, these fits tend to show that, over the eight studied multi-planetary system...

  2. Consumer Knowledge of Over-the-Counter Phenazopyridine

    OpenAIRE

    Shi, Chih-Wen; Asch, Steven M.; Fielder, Eve; Gelberg, Lillian; Michael B. Nichol

    2004-01-01

    BACKGROUND Effective use of over-the-counter (OTC) medications depends on purchasers’ knowledge of their indications. This study examines consumer knowledge regarding the urinary tract analgesic phenazopyridine, which recently became available without prescription.

  3. Discrimination capability of avalanche counters detecting different ionizing particles

    International Nuclear Information System (INIS)

    The discrimination capability of avalanche counters to detect different ionizing particles has been studied using a 252Cf 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 32S ions are also reported. (orig.)

  4. The optimized design of the Gray-code counter

    International Nuclear Information System (INIS)

    This article has expatiated on the signality of using Gray-code in designing high-speed digital circuit,and given the low-power-cost analysis in the use of Gray-code counter. The main content of this article is the design and realization of a Gray-code counter. This design has formed an n-bit Gray-code counter with n piece main D-trigger and one piece assistant D-trigger, by the speciality of Gray-code. In the end, this article has given the realization of this counter's core by VHDL, this VHDL realization may be the guidance for the forward job on FPGA design and some other domain. (authors)

  5. Counter-propagating patterns in the BioPhotonics Workstation

    DEFF Research Database (Denmark)

    Palima, Darwin; Lindballe, T.; Kristensen, M.V.;

    2010-01-01

    stable three-dimensional manipulation of multiple particles. In this work, we analyze counter-propagating shaped-beam traps that depart from this conventional geometry. We show that projecting shaped beams with separation distances previously considered axially unstable can, in fact, enhance the trap by......The counter-propagating geometry opens an extra degree of freedom for shaping light while subsuming single-sided illumination as a special case (i.e., one beam set turned off). In its conventional operation, our BioPhotonics Workstation (BWS) uses symmetric, co-axial counter-propagating beams for...... improving axial and transverse trapping stiffness. We also show interesting results of trapping and micromanipulation experiments that combine optical forces with fluidic forces. These results hint about the rich potential of using patterned counter-propagating beams for optical trapping and manipulation...

  6. Over-the-counter codeine use in Iceland

    DEFF Research Database (Denmark)

    Almarsdóttir, Anna Birna; Grimsson, A

    2000-01-01

    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....

  7. Construction and operating characteristics of flexible Geiger counters

    International Nuclear Information System (INIS)

    A method has been developed for constructing flexible Geiger counters in a wide range of lengths and diameters. The counters are quite flexible: a 3-cm diam. counter can be bent to a circle of 5 cm radius. Using Q-gas (98.3% helium, 1.7% n-butane) as the counting medium, plateaux are several hundred volts long with 3% slopes and are independent of the counter configuration. Counters are constructed from tubing having a polyvinyl-chloride formulation (PVC-744 - Alpha Wire Corp.). Short segments of the plastic tubing (length ∼ 3 times the tube diameter) are slipped over a coarsely threaded aluminium mandrel. Wire is wrapped tightly in the threads and the whole is placed in a 110oC oven for 20 min. After cooling, the corrugated plastic segment is removed from the mandrel. This corrugation prevents the collapse of the tubing when it is coiled. A polystyrene disk, perforated with relatively large holes near the periphery for gas flow and having a 0.6-mm hole in the centre for the anode, is fastened in one end of each segment. By threading the segments thus prepared on a 3-mil tungsten anode and slipping one end of each segment over the adjacent segment and securing them with an adhesive, a counter of any desired length can be built up. Glass end-pieces for attaching the anode ends and for admitting and exhausting the flow gas are attached. A bare copper wire spiralled in the grooves of the counter makes a satisfactory external cathode which operates in the manner observed by MAZE. A 3-cm diam. counter, 1 m long, either linear or coiled, has a plateau beginning at 1400 V and extending beyond 1750 V with a 2.9% slope. Counting rates in excess of 300000 counts/min with little coincidence loss have been observed. Since the counter is actually a series of short Geiger counters and the discharge does not spread beyond the polystyrene spacer disks, adjacent counter segments operate independently. Pulse heights are greater than 50 mV. (author)

  8. High-level neutron coincidence counter (HLNCC): users' manual

    International Nuclear Information System (INIS)

    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 240Pu 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

  9. The efficiency of counter telescopes for intermediate energy protons

    International Nuclear Information System (INIS)

    The efficiency of counter telescopes containing a 15.2 cm thick NaI(Tl) crystal for detecting protons with energies in the range 50-350 MeV has been measured. An investigation was made of the dependence of the efficiency on the position of the proton in the counter. The results of the measurements are in close agreement with the calculations of efficiencies using available reaction cross section data. (orig.)

  10. Detailed Network Measurements Using Sparse Graph Counters: The Theory

    OpenAIRE

    Lu, Yi; Montanari, Andrea; Prabhakar, Balaji

    2007-01-01

    Measuring network flow sizes is important for tasks like accounting/billing, network forensics and security. Per-flow accounting is considered hard because it requires that many counters be updated at a very high speed; however, the large fast memories needed for storing the counters are prohibitively expensive. Therefore, current approaches aim to obtain approximate flow counts; that is, to detect large elephant flows and then measure their sizes. Recently the authors and their collaborators...

  11. Applicability of condensation particle counters to measure atmospheric clusters

    OpenAIRE

    Sipilä, M.; Lehtipalo, K.; M. Kulmala; T. Petäjä; Junninen, H.; Aalto, P.P.; Manninen, H. E.; E.-M. Kyrö; Asmi, E.; Riipinen, I; J. Curtius; A. Kürten; S. Borrmann; C. D. O'Dowd

    2008-01-01

    The ambient and laboratory molecular and ion clusters were investigated. Here we present data on the ambient concentrations of both charged and uncharged molecular clusters as well as the performance of a pulse height condensation particle counter (PH-CPC) and an expansion condensation particle counter (E-CPC). The ambient molecular cluster concentrations were measured using both instruments, and they were deployed in conjunction with ion spectrometers and other aerosol instruments in Hyytiäl...

  12. Job Market Signalling, Stereotype Threat, and Counter-Stereotypical Behavior.

    OpenAIRE

    Richard Chisik

    2010-01-01

    ABSTRACT: We introduce stereotype threat in a multiple-productivity signalling model. Existence of multiple self-fulfilling stereotypes, which can generate statistical discrimination, is more likely if there is less variance in the ability distribution. A low endogenously-correct stereotype about a group forces higher-ability group members to choose a higher-productivity and a higher separating signal, thereby engaging in counter-stereotypical behaviour. This counter-stereotypical behaviour c...

  13. Can counter-terrorist internment ever be legitimate ?

    OpenAIRE

    de Londras, F.

    2011-01-01

    Counter-terrorist internment is generally rejected as illegitimate from a human rights perspective. However, while the practice of counter-terrorist internment has long resulted in the infringement of human rights, this article argues that the concept of internment holds some potential for legitimacy. This potential can only be realized if four legitimacy factors are fully embraced and complied with: public justificatory deliberation, non-discrimination, meaningful review, and effective tempo...

  14. MONITORING THE SAFETY ASPECTS OF OVER THE COUNTER MEDICATIONS

    OpenAIRE

    M.Z. Subin; V.Vidya; O.A. Halima; G. Geethu; N. Devika

    2012-01-01

    OTC medication is short for over the counter drugs. These medicines have become popular as they are available without a prescription from the doctor. These are medicaments that are usually used to relieve pain and to treat various symptoms of cold. Most of the over-the-counter users believe that these medications are safer and are devoid of unwanted side effects. But their use may become fatal sometimes when they are administered without knowing the prescription pattern, that is, when they ar...

  15. Counter-Punishment, Communication, and Cooperation among Partners

    OpenAIRE

    Andrighetto, Giulia; Brandts, Jordi; Conte, Rosaria; Sabater-mir, Jordi; Solaz, Hector; Székely, Áron; Villatoro, Daniel

    2016-01-01

    We study how communication affects cooperation in an experimental public goods environment with punishment and counter-punishment opportunities. Participants interacted over 30 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 involvin...

  16. 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.

  17. The Effectiveness of Israel's counter-terrorism strategy

    OpenAIRE

    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. It will study how the impact of past wars, campaigns, and deadly terrorist attacks influenced the thinking of past and current leaders. By gauging the actions, and sometimes nonactions, of the international community, the Israeli government declined to become ...

  18. Over-the-counter treatments for acne and rosacea.

    Science.gov (United States)

    Rosamilia, Lorraine Larsen

    2016-06-01

    Acne and rosacea are common inflammatory processes historically classified in the same disease category, but evolving understanding of their disparate pathophysiology and exacerbating factors have generated an enormous armamentarium of therapeutic possibilities. Patients seek over-the-counter therapies first when managing cutaneous disease; therefore, this review defines ingredients considered to be effective over-the-counter acne and rosacea products, their mechanisms, and safe formulations, including botanical components, oral supplements, and other anecdotal options in this vast skin care domain. PMID:27416314

  19. Effect of the troposphere on surface neutron counter measurements

    OpenAIRE

    Aplin, K. L.; Harrison, R. G.; Bennett, A.J.

    2005-01-01

    Surface neutron counter data are often used as a proxy for atmospheric ionisation from cosmic rays in studies of extraterrestrial effects on climate. Neutron counter instrumentation was developed in the 1950s and relationships between neutron counts, ionisation and meteorological conditions were investigated thoroughly using the techniques available at the time; the analysis can now be extended using modern data. Whilst surface neutron counts are shown to be a good proxy for ionisation rate, ...

  20. Threshold gas 32-channel Cherenkov counter of the spectrometer EXCHARM

    International Nuclear Information System (INIS)

    The Cherenkov 32-channel threshold gas counter with 420-cm air radiator at the atmospheric pressure is described. Spherical mirrors with the curvature radius of 214 cm and photomultipliers FEU-125, FEU-49B were used in the counter for collection and registration of the Cherenkov radiation. The photomultipliers inlet windows are covered with films of spectra mixers. The efficiency of charged particles registration on the plateau of threshold characteristics (β ≥ 0.99984) exceeds 97%. 6 refs., 6 figs., 1 tab

  1. A comprehensive test specification for pulse fission counters

    International Nuclear Information System (INIS)

    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)

  2. Advertising health: the case for counter-ads.

    Science.gov (United States)

    Dorfman, L; Wallack, L

    1993-01-01

    Public service advertisements have been used by many in hopes of "selling" good health behaviors. But selling good behavior--even if it could be done more effectively--is not the best goal for using mass media to prevent health problems. Personal behavior is only part of what determines health status. Social conditions and the physical environment are important determinants of health that are usually ignored by health promotion advertising. Public service advertising may be doing more harm than good if it is diverting attention from more effective socially based health promotion strategies. Counter-ads are one communications strategy that could be used to promote a broader responsibility for rectifying health problems. In the tradition of advocacy advertising directly promoting policy rather than products, counter-ads promote views consistent with a public health perspective. Counter-ads set the agenda for health issues, conferring status on policy-oriented strategies for addressing health problems. The primary purpose of counter-ads is to challenge the dominant view that public health problems reflect personal health habits. They are controversial because they place health issues in a social and political context. Advertising strategies for health promotion range over a spectrum from individually oriented public service advertising to socially oriented counter-advertising. The recent anti-tobacco campaign from the California Department of Health Services represents advertisements across the spectrum. Counter-ads that focus on a politically controversial definition for health problems are an appropriate and necessary alternative to public service advertising. PMID:8265756

  3. Performance of gas proportional counters at high pressures

    International Nuclear Information System (INIS)

    The performances of gas proportional counters intended to some isotopes absolute activity measurements are investigated at a gas pressure ranging from 5 to 100 atm. The counter working agent (filling gas) is pure Ar and the CH4/Ar,Xe/Ar,CH4/Xe/Ar gas mixtures. The counter has cathode diameters 6,10,14 mm and anode diameters are 10,16,20 μm. It is found that an addition of 0.5% Xe to Ar results in a considerable decrease (approximately by a factor of 2) of working voltage applied to counters, compared to pure Ar filling, just as maximum gas amplification factor is increased. The counter energy resolution is 5.5-7% (FWHM) for 241Am γ-quanta with the 59.57 keV energy at Ar+0.5% Xe mixture pressure ranging from 8 to 100 atm. It is shown that it is more efficiently to use argon with addition of xenon, but no methan for stabilization of the gas counters performance at high pressures

  4. A high resolution Timing Counter for the MEG II experiment

    Science.gov (United States)

    De Gerone, M.; Bevilacqua, A.; Biasotti, M.; Boca, G.; Cattaneo, P. W.; Gatti, F.; Nishimura, M.; Ootani, W.; Pizzigoni, G.; Rossella, M.; Shibata, N.; Siccardi, F.; Simonetta, M.; Uchiyama, Y.; Yoshida, K.

    2016-07-01

    The development of a Timing Counter detector designed for the MEGII upgrade of the MEG experiment, which strives to improve the sensitivity on the μ+ →e+ γ decay of an order of magnitude, is presented. It is based on two sets of counters (sectors) arranged on a semi-cylindrical structure; each sector consists of 256 counters. Each counter consists of tile of fast scintillator with a dual-side read-out based on SiPM arrays in series connection. The high granularity has two advantages: optimized size for achieving high resolution (75 ps) for the single counter, and a signal e+ crosses several counters, so that resolution improves by averaging multiple time measurements. A prototype has been built and tested both in BTF and PSI facilities in order to prove the multi-hit scheme in MEG-like beam conditions. A 35 ps resolution with eight hits has been obtained with a e+ beam at 100 kHz. The first sector will be tested in the MEG II pre-engineering run planned at the end of 2015.

  5. Modeling of electron and ion kinetics in cylindrical proportional counters

    International Nuclear Information System (INIS)

    Numerical simulations were performed to study the operating mode of cylindrical proportional counters submitted to irradiation. Such counters are used in astrophysics, high energy physics and microdosimetry. The choice of the filling gas was restricted to argon, methane and their mixtures, in order to allow us to compare our numerical values to experimental results from the literature. The charged particle kinetics in the gaseous volume of the counter were studied by two numerical methods: The electron transport parameters were determined by microscopic calculations. These calculations also showed that electrons and the applied electric field were not in equilibrium in such geometries. The values obtained for the ionization coefficient were used to estimate the effects of the non-equilibrium phenomena on the theoretical value of the counter gas gain. A macroscopic modelling of the electron and ion transport was used to study the electron avalanche induced by a particle crossing the counter. In particular, the consequences of the appearance of the space charge effect on the gas gain value and on the current pulses were studied as a function of the operating conditions of the counter

  6. Development of Pre-amplifier Module for BF_3 Counting Tube

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    According to the calculation of radiation protection, the neutron energy in the cyclotron vault ranges from the thermal neutrons to 100 MeV when the machine is in operation. To monitor the neutron energy on such a wide domain requires special

  7. BF3·OEt2 Promoted Solvent-free Synthesis of Benzimidazole Derivatives

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Differently substituted benzimidazoles have been synthesized in very good yields in catalyst. The method is applicable to aromatic, unsaturated and aliphatic aldehydes and to substituted o-phenylenediamines without significant differences.

  8. Design and performances of the Scrap Neutron Multiplicity Counter

    International Nuclear Information System (INIS)

    JRC has developed the Scrap Neutron Multiplicity Counter (SNMC): an advanced neutron multiplicity counter for the verification of inhomogeneous Pu samples, such as scrap material in MOX fuel fabrication plants. The innovative features of this counter with respect to existing ones rely on two aspects: (i) an optimised design based on Monte Carlo calculations in order to select the most appropriate materials, geometry and detector disposition for maximum efficiency and (ii) novel electronics based on digital signal processing (DSP) reducing the system dead time. The paper recalls the design process, the electronics, the construction and assembly of the counter. Then the results of the first experimental tests will be reported. We will show the characterization of the main physical parameters of the counter, the calibration and the verification of a wide variety of plutonium bearing samples available in the PERLA laboratory at JRC Ispra. This will include pure homogeneous samples (Pu dioxide powders, metal Pu, MOX powders and pellets) and some tests on heterogeneous samples representative of scrap material

  9. Boron-lined proportional counters with improved neutron sensitivity

    CERN Document Server

    Dighe, P M; Prasad, K R; Kataria, S K; Athavale, S N; Pappachan, A L; Grover, A K

    2003-01-01

    Boron-lined proportional counters with higher neutron sensitivity have been developed by introducing baffle structures within the sensitive volume. the results are compared to devices developed with multiple cathode assemblies in a single enclosure. in either case, the increase in the boron-coated surface area results in higher neutron sensitivity. one of these counters has 51 annular baffles coated with natural boron with 10 mm hole for the anode wire to pass through. filled with p-10 gas at 20 cm hg, it has an overall diameter of 30 and 300 mm length. multiple dip coating method was employed for better uniformity in boron thickness. the neutron sensitivity of this counter is 1.6 cps/nv, which is 2.5 times that of a counter with standard electrode geometry. another counter was developed with three cathode assemblies (30 mm IDx300 mm) coated with 92% sup 1 sup 0 B while the third has seven assemblies coated with natural boron (16 mm IDx750 mm length). the neutron sensitivity is 10 and 5.5 cps/nv, respectively...

  10. Design and performance study of the TOP counter

    International Nuclear Information System (INIS)

    A novel RICH detector called TOP counter has been developed for particle identification in Belle II. It measures the time of propagation (TOP) of Cherenkov photons traveling in the quartz radiator with micro-channel-plate photomultiplier tubes (MCP-PMTs) with a precision of 50 ps. A prototype TOP counter was tested with the 1.2 GeV/c electron beam in the Laser Electron Photon beam line at SPring-8 (LEPS). The TOP distribution was obtained as expected after taking into account the dependence of the MCP-PMT quantum efficiency on light incidence angle and polarization. In this paper, the key features of the TOP counter design and the beam test results are presented. -- Highlights: •The TOP counter has been developed for particle identification in Belle II. •A time of propagation (TOP) of Cherenkov light in the quartz radiator is measured. •Cherenkov light is detected by the MCP-PMTs with a resolution of about 40 ps. •A prototype TOP counter was tested with the 1.2 GeV/c electron beam at LEPS. •The TOP distribution measured in the beam test agrees with the expectation

  11. Response of 4π Proportional Counters to γ-Rays

    International Nuclear Information System (INIS)

    The response of a 4π proportional counter to γ-rays has been measured as a function of γ-ray energy by the 4π β-γ coincidence-absorption method. The results, which are about a factor of three lower than those obtained using thick absorbers, are slightly lower than, but in general agreement with, those of Williams and Campion. Electrons produced by γ-ray interactions in the absorber are responsible for the higher results obtained with thick absorbers. This effect has been demonstrated by determining the γ-ray response of a 4π proportional counter as a function of absorber thickness for the 478-keV γ-rays of 7Be. In addition, the responses to 478-keV γ-rays of five different 4π proportional counters have been compared. For one of these, a pressurized 4π X-ray counter, the response has also been measured as a function of filling pressure. It is concluded that the intrinsic γ-ray response of 4π proportional counters is small and, if γ-ray absorption in the counting gas may be neglected, is not strongly dependent on the size, shape or material of the cathode. (author)

  12. Detailed Network Measurements Using Sparse Graph Counters: The Theory

    CERN Document Server

    Lu, Yi; Prabhakar, Balaji

    2007-01-01

    Measuring network flow sizes is important for tasks like accounting/billing, network forensics and security. Per-flow accounting is considered hard because it requires that many counters be updated at a very high speed; however, the large fast memories needed for storing the counters are prohibitively expensive. Therefore, current approaches aim to obtain approximate flow counts; that is, to detect large elephant flows and then measure their sizes. Recently the authors and their collaborators have developed [1] a novel method for per-flow traffic measurement that is fast, highly memory efficient and accurate. At the core of this method is a novel counter architecture called "counter braids.'' In this paper, we analyze the performance of the counter braid architecture under a Maximum Likelihood (ML) flow size estimation algorithm and show that it is optimal; that is, the number of bits needed to store the size of a flow matches the entropy lower bound. While the ML algorithm is optimal, it is too complex to im...

  13. Thermal Transport in NCS Plasmas with Counter Neutral Beam Injection

    Science.gov (United States)

    Stallard, B. W.; Casper, T. A.; Greenfield, C. M.; Burrell, K. H.; Gohil, P.; Lohr, J.; Petty, C. C.; Synakowski, E.; Austin, M. E.; McKee, G. R.; Rettig, C. L.; Rhodes, T. L.; Zeng, L.

    1999-11-01

    Recent experiments in DIII-D have investigated internal transport barrier (ITB) formation with neutral beams injected in the counter-current direction, assisted by early ECH during current ramp up. For counter injection the v_torBT term for radial force balance adds to the nabla p term to determine E× B flow shear. Compared to ITB plasmas with co-current injection, characteristics with counter injection at similar beam power are: (a) broader profiles of T_I, T_e, n_e, and ω_tor within a larger barrier radius, (b) reduced profile gradients in the barrier region, and (c) about a factor of 2 higher Z_eff ( ~4) from the carbon impurity. In this paper profile evolution and results of transport analysis will be compared with co-injection plasmas.

  14. 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...

  15. 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...

  16. Performance of Boron-10 based Neutron Coincidence Counters

    International Nuclear Information System (INIS)

    Helium-3 gas-filled detectors have been used in neutron coincidence counting for non-destructive assay for over 30 years. With the current shortage of 3He gas, GE's Reuter-Stokes business developed a 10B lined proportional counter and a 10B hybrid coincidence counter, in which a small amount of 3He is added to a 10B detector to enhance the neutron sensitivity. GE's Reuter-Stokes business modelled, designed, built and tested prototype coincidence counters using the 10B lined detectors and the 10B hybrid detectors. We will present these systems and their applications for non-destructive assay. (author)

  17. Organizational Identity Negotiations through Dominant and Counter Narratives

    DEFF Research Database (Denmark)

    Humle, Didde; Frandsen, Sanne

    of a highly contested organization, E-rail, we examine ticket inspectors’ story work to demonstrate how counter-narratives make room for multiple – and sometimes even opposing - understandings of organizational identity to co-exist. Our analysis shows that ticket inspectors in their story work draw......In this paper, we see the organization as a polyphonic, storytelling community and study the role of dominant and counter narratives in organizational identity formation processes as a web of stories performed and negotiated by organizational members and external stakeholders. Based on a case study...... explicitly on the media’s as well as management’s dominating narratives in constructing counter-narratives and creating shared understandings of who they are and what they do. These multiple understandings of organizational identity make it possible for organizational members to perform and pursue different...

  18. Address Counter Generators for Low Power Memory BIST

    Directory of Open Access Journals (Sweden)

    Balwinder Singh

    2011-07-01

    Full Text Available In today's Integrated Circuits (IC's designs Built-in Self Test (BIST is becoming important for the memory which is the most necessary part of the System on Chip. The March algorithm has been widely used to test memory core of System on chip (SOC. LFSRs and counters are mainly used to generate the memory addresses, which can be serially applied to the memory cores under test. In this paper Address counters and Data generators (i.e. parts of the MBIST are designed. These implemented in Hardware Description Language (HDL, and the area and power analyzed for each case . From the analyzed results the low power LFSRs and counters can be identify for the low power memory BIST design.

  19. Electrical characteristics of sphere-plane type spark counters

    International Nuclear Information System (INIS)

    The authors describe here the mechanical construction and operating characteristics of spark detectors using a small (0.30 mm) diameter sphere as anode, set opposite to a plane cathode and working by the ''corona'' effect, in air at atmospheric pressure. Counting characteristics are very similar to those of Rosenblum-type anode wire detectors. However, the sphere counter has a certain superiority over the Rosenblum counter inherent in its geometry : (a) there sidual current (background) is low and the release of ozone and nitrous oxides during the spark is not of great significance; (b) its self-capacity being very small, the detector gives a faster response; (c) unlike in the case of wire counters, efficiency is independent of particle incidence direction; (d) its sensitive volume, that of a solid of revolution around the axis of symmetry of the detector, amounts to a few cubic millimetres and, being very clearly defined, permits realization of accurate telescopic devices. (author)

  20. Interactive hypermedia training manual for spent-fuel bundle counters

    International Nuclear Information System (INIS)

    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

  1. 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.

  2. Safeguards Technology Factsheet 3He-free Neutron Coincidence Counter

    International Nuclear Information System (INIS)

    A full scale thermal neutron coincidence counter (High Level Neutron Counter - Boron: HLNB) based on 3He alternative detection technology was designed and built at LANL and field tested at Plutonium Conversion Development Facility (PCDF) of Japan Atomic Energy Agency (JAEA) during FY15. HLNB is based on boron-lined proportional plates that replace the traditional 3He proportional tubes and was designed as a direct alternative to 3He-based High Level Neutron Coincidence Counter (HLNC-II). During the JAEA field trial the HLNB demonstrated comparable performance to HLNC-II, which represents a key development in the area of 3He alternative technologies and provides a complete demonstration of the technology for nuclear safeguards applications including high mass MOX samples.

  3. The assembly of the Belle II TOP counter

    International Nuclear Information System (INIS)

    A new type of ring-imaging Cherenkov counter, called TOP counter, has been developed for particle identification at the Belle II experiment to run at the SuperKEKB accelerator in KEK, Japan. The detector consists of 16 identical modules arranged azimuthally around the beam line. The assembly procedure for a TOP module is described. This procedure includes acceptance testing of the quartz mirror, prism, and quartz bar radiators. The acceptance tests include a chip search and measurements of bulk transmittance and total internal reflectance. The process for aligning and gluing the optical components together is described. - Highlights: • The fabrication process of the TOP counter has been established. • We did the acceptance tests for the first few optical components. • The qualities of the optical components satisfy our requirements. • The tests of the gluing procedure have been taking place

  4. Study on the gridded spark counter in air

    International Nuclear Information System (INIS)

    The performance of gridded spark counter (GSC) with double anode wires in dry air is described in details. The normal double-wire-plane counter was provided with a grid between the source and wires anode. The slope of the counting plateau, and the threshold voltage was proved to be strongly dependent on the grid voltage. also the grid voltage has been shown to be a decisive element of the steady corona current conformation and hence the sensitivity of the counter. The experimental results on the counting and quiescent corona current characteristics are expressed by analytical formulae. Also the properties of the (GSC) when used as corona voltage stabilizer and regulator device were investigated

  5. Radiosonde aerosol counter for vertical profiling of atmospheric dust layers

    Science.gov (United States)

    Ulanowski, Z.; Hirst, E.; Kaye, P. H.; Harrison, R. G.; Nicoll, K. A.; Rogers, G.

    2010-05-01

    A low-cost, miniature aerosol particle counter has been developed, intended for use with balloon-borne meteorological radiosondes. It is particularly suitable for airborne mineral dust measurements. Ambient air is drawn into the counter using a diaphragm pump at a rate of 0.5 litre per minute. The counter detects particles in the airstream using a diode laser and a photodiode. Output from the photodiode is digitised into 5 size bins, with minimum particle diameters equivalent to 0.6, 1.4, 2.6, 5.4 and 10.6 micrometers. The counter is interfaced to a Vaisala RS92 radiosonde, which transmits data from the counter together with meteorological parameters and GPS-derived position to a ground based receiver at 1 Hz rate. Statistically significant particle size distributions can be obtained once a second for number concentrations down to about 100,000 particle per litre (within the measured size range), or correspondingly less at lower temporal resolutions. At the same time, the counter is capable of measuring dust number concentrations exceeding a million per litre without incurring significant errors. Soundings during the DREAME campaign in Kuwait (Ulanowski et al. EGU 2010, AS4.7) and on Cape Verde Islands (Nicoll et al. EGU 2010, AS4.7) provided dust concentration profiles with a typical vertical resolution of 4 m. Comparisons with integrated dust column size distribution measurements from AERONET sun photometers showed good agreement in two out of three cases where near-simultaneous retrievals were available. Optical thickness calculations based on the size distributions measured in Kuwait, with the assumption that the dust particles were prolate spheroids, agreed with the AERONET optical thickness at 675 nm to within 15%.

  6. Features of the microstrip proportional counter technology (invited)

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Carl

    1992-01-01

    The microstrip proportional counter (MSPC) is a new approach in gas-filled detector technology. In contrast with the classical multiwire proportional counter (MWPC) detectors, the electrodes of the MSPC are deposited by photolithographic techniques onto a rigid substrate. The technique offers many...... the anode and cathode strips which allows the positive ion cloud created in the avalanche to be collected rapidly with reduced space charge effects and increased counting-rate capability; A rigid electrode structure which is not deformed under the action of an electric field; A relatively simple fabrication...

  7. Full simulation of the Sudbury Neutrino Observatory proportional counters

    International Nuclear Information System (INIS)

    The third phase of the Sudbury Neutrino Observatory (SNO) experiment added an array of 3He proportional counters to the detector. The purpose of this neutral-current detection (NCD) array was to observe neutrons resulting from neutral-current solar-neutrino-deuteron interactions. We have developed a detailed simulation of current pulses from NCD array proportional counters, from the primary neutron capture on 3He through NCD array signal-processing electronics. This NCD array MC simulation was used to model the alpha-decay background in SNO's third-phase 8B solar-neutrino measurement.

  8. Introduction to Neutron Coincidence Counter Design Based on Boron-10

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

    2012-01-22

    The Department of Energy Office of Nonproliferation Policy (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is ultimately to design, build and demonstrate a boron-lined proportional tube based alternative system in the configuration of a coincidence counter. This report, providing background information for this project, is the deliverable under Task 1 of the project.

  9. Performance of Scintillator Counters with Silicon Photomultiplier Readout

    OpenAIRE

    Mu2e Collaboration Cosmic Ray Veto Group; Artikov, A.; Baranov, V.; Chokheli, D.; Davydov, Yu. I.; Dukes, E. C.; Ehrlich, R.; Francis, K; Frank, M J; Glagolev, V.; Group, R. C.; Hansen, S.; Hocker, A.; Oksuzian, Y.; Rubinov, P.

    2015-01-01

    The performance of scintillator counters with embedded wavelength-shifting fibers has been measured in the Fermilab Meson Test Beam Facility using 120 GeV protons. The counters were extruded with a titanium dioxide surface coating and two channels for fibers at the Fermilab NICADD facility. Each fiber end is read out by a 2*2 mm^2 silicon photomultiplier. The signals were amplified and digitized by a custom-made front-end electronics board. Combinations of 5*2 cm^2 and 6*2 cm^2 extrusion prof...

  10. Experimental investigation on ducted counter-rotating axial flow fans

    OpenAIRE

    Nouri, Hussain; Ravelet, Florent; Bakir, Farid; Sarraf, Christophe

    2011-01-01

    An experimental study on counter-rotating axial-flow fans was carried out. The fans of diameter D = 375 mm were designed using an inverse method. The counter-rotating fans operate in a ducted-flow configuration and the overall performances are measured in a normalized test bench. The rotation rate of each fan is independently controlled. The axial spacing between the fans can vary from 10 to 50 mm by steps of 10 mm. The results show that the efficiency is strongly increased compared to a conv...

  11. Scintillation counters for multichannel time-of-flight system

    International Nuclear Information System (INIS)

    The average time resolution (σ) of about 70 ps is obtained for each of four scintillation counters at a long duration test on the CERN SPS particle beam. The counters were assembled of 2.4 x 2.4 x 6.0 cm3 scintillator bars and FEU-87 (CsSb) type photomultipliers, both made in Russia. We observed the non-stability of mean time-of-flight (TOF) value during the runs. The maximum TOF drift contribution into the time resolution is estimated as (10-15 %)

  12. A neutron scintillation counter with low sensitivity for γ rays

    International Nuclear Information System (INIS)

    The paper describes a simple scintillation counter circuit with a high efficiency for recording neutrons and a low efficiency for gamma rays. The operation of the counter is based on the different shape of the scintillation pulses produced in stilbene by neutrons and gamma quanta. Separation is obtained over a wide range of neutron energies. The minimum energy for which neutrons can be distinguished from the gamma background is 80 keV. In neutron recording the amplitude characteristic of the output pulses is approximately linear. The question of the degree to which counts due to the gamma background can be eliminated is also discussed. (author)

  13. Full simulation of the Sudbury Neutrino Observatory proportional counters

    CERN Document Server

    Beltran, B; Cai, B.; Cox, G.A.; Deng, H.; Detwiler, J.; Formaggio, J.A.; Habib, S.; Hallin, A.L.; Hime, A.; Huang, M.; Kraus, C.; Leslie, H.R.; Loach, J.C.; Martin, R.; McGee, S.; Miller, M.L.; Monreal, B.; Monroe, J.; Oblath, N.S.; Peeters, S.J.M.; Poon, A.W.P.; Prior, G.; Rielage, K.; Robertson, R.G.H.; Smith, M.W.E.; Stonehill, L.C.; Tolich, N.; Van Wechel, T.; Wan Chan Tseung, H.; Wendland, J.; Wilkerson, J.F.; Wright, A.

    2011-01-01

    The third phase of the Sudbury Neutrino Observatory (SNO) experiment added an array of 3He proportional counters to the detector. The purpose of this Neutral Current Detection (NCD) array was to observe neutrons resulting from neutral-current solar neutrino-deuteron interactions. We have developed a detailed simulation of the current pulses from the NCD array proportional counters, from the primary neutron capture on 3He through the NCD array signal-processing electronics. This NCD array Monte Carlo simulation was used to model the alpha-decay background in SNO's third-phase 8B solar-neutrino measurement.

  14. Digital Electronics for the Pierre Auger Observatory AMIGA Muon Counters

    OpenAIRE

    Wainberg, O.; A. Almela; Platino, M.; Sanchez, F.; Suarez, F.; Lucero, A.; Videla, M.; B. Wundheiler; Melo, D.; Hampel, M.; Etchegoyen, A.

    2013-01-01

    The "Auger Muons and Infill for the Ground Array" (AMIGA) project provides direct muon counting capacity to the Pierre Auger Observatory and extends its energy detection range down to 0.3 EeV. It currently consists of 61 detector pairs (a Cherenkov surface detector and a buried muon counter) distributed over a 23.5 km2 area on a 750 m triangular grid. Each counter relies on segmented scintillator modules storing a logical train of '0's and '1's on each scintillator segment at a given time slo...

  15. TOP counter for particle identification at the Belle II experiment

    Science.gov (United States)

    Inami, Kenji

    2014-12-01

    Ring imaging Cherenkov counter, named TOP counter, utilizing precise photon detection timing has been developed as a particle identification detector for the Belle II experiment. The real size prototype has been produced and tested with 2 GeV positrons at Spring-8 LEPS beam line. The quartz radiator production and assembling with microchannel plate photomultipliers was successfully carried out. The beam test data shows good agreement with full Monte-Carlo simulation results in the ring image and the distribution of number of detected photons and timing information.

  16. The parallel plate avalanche counter: a simple, rugged, imaging X-ray counter

    International Nuclear Information System (INIS)

    A two-dimensional parallel gap proportional counter has been developed at the Danish Space Research Institute. Imaging over the 120 mm diameter active area is obtained using the positive ion component of the avalanche signals as recorded by a system of wedge- and strip-electrodes. An electronically simple, but very effective background rejection is obtained by using the fast electron component of the avalanche signal. Gas gains up to 8x105 have been achieved. An energy-resolution of 16% and a sub-millimeter spatial resolution have been measured at 5.9 keV for an operating gas gain of 105. In principle, the position coordinates are linear functions of electronic readouts. The present model, however, exhibits non-linearities, caused by imperfections in the wedge and strip-electrode pattern. These non-linearities are corrected by using a bilinear correction algorithm. We conclude that the rugged construction, the simple electronics, the effectiveness of the background rejection and the actual imaging performance makes this a very attractive laboratory detector for low and intermediate count rate imaging applications. ((orig.))

  17. Design of a hybrid gas proportional counter with CdTe guard counters for 14C dating system

    International Nuclear Information System (INIS)

    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 14C 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 than 24 keV which is low enough for 99.8% anticoincidence efficiency. The experiment showed an anticoincidence efficiency for outer gamma rays from 70% to 80%, similar to that of the old 14C counter. The lost anticoincidence efficiency results from the area of 21.74% which was not covered with CdTe due to two holes for the path of the center anode wire and slots between every two sides of CdTe detectors

  18. Design of a hybrid gas proportional counter with CdTe guard counters for {sup 14}C dating system

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, L. E-mail: lan@sophie.q.t.u-tokyo.ac.jp; Takahashi, H.; Hinamoto, N.; Nakazawa, M.; Yoshida, K

    2002-02-01

    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 14}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 than 24 keV which is low enough for 99.8% anticoincidence efficiency. The experiment showed an anticoincidence efficiency for outer gamma rays from 70% to 80%, similar to that of the old {sup 14}C counter. The lost anticoincidence efficiency results from the area of 21.74% which was not covered with CdTe due to two holes for the path of the center anode wire and slots between every two sides of CdTe detectors.

  19. A note on counter-transference and anti-Semitism.

    Science.gov (United States)

    Traub-Werner, D

    1979-10-01

    After a brief introduction where the meaning of racism is alluded to, a clinical vignette is presented. A patient who has suppressed her antisemitic feelings is being treated by a Jewish psychiatrist. The therapist's possible counter-transference motives in treating the patient are explored, and a workable solution is offered. PMID:487349

  20. Oltre COUNTER: quello che le statistiche di uso non dicono

    OpenAIRE

    Cassella, Maria

    2008-01-01

    Quantitative e-measures for Electronic Resources are consolidating through COUNTER reports and SUSHI new Protocol. Even though some problems remain in order to evaluate correctly data. Particularly, new studies confirm the importance to combine quantitative data with qualitative analysis on users' needs and satisfaction. MINES for Libraries methodoloyy and a 2008 CIBER (UK) study on the Google Generation are also discussed.

  1. Counter-intuitive Cases of Data Fusion in Information Retrieval.

    Science.gov (United States)

    Ibraev, Ulukbek; Kantor, Paul; Ng, K. B.

    2001-01-01

    Aspects of Data Fusion (DF) for information retrieval are explored. Based on a geometrical model of DF, it is shown that in the ideal case, performance of DF for a pair of information retrieval schemes may be approximated by a quadratic polynomial. Compares counter-intuitive cases of DF with cases that behave according to the geometric model. (AEF)

  2. G.M. counter and pre-determined dead time

    International Nuclear Information System (INIS)

    This paper is divided into two main parts. - The first section recalls the principle on which a G.M. counter works, and examines the factors which lead to inaccuracies in counting. The concept of dead time, although simple risen associated with the counter alone, becomes complicated as soon as an electronic dead time is introduced to meet the demands of a measurement or an experiment. The resulting dead time, due to the coexistence of these dead times created by a single motivating factor, shows up as a function of certain laws of probability. From the analysis of the various cases of possible combinations, the conditions which must be fulfilled by a system with pre-determined dead time may be determined. This leads to a method for measuring the dead time of a G.M. counter, and the possibility of studying the latter under the utilisation conditions foreseen. - In the second part the principle, construction and characteristics of two systems with pre-determined dead time are discussed. To conclude, a comparison of several experimental results justifies an extension of the possibilities of a G.M. counter used in conjunction with such a system. (author)

  3. Cationic lipid membranes-specific interactions with counter-ions

    Energy Technology Data Exchange (ETDEWEB)

    Ryhaenen, Samppa J; Saeily, V Matti J; Kinnunen, Paavo K J [Helsinki Biophysics and Biomembrane Group, Institute of Biomedicine, Biomedicum, University of Helsinki, PO Box 63 (Haartmaninkatu 8), Helsinki FIN-00014 (Finland)

    2006-07-19

    Lipids bearing net electric charges in their hydrophilic headgroups are ubiquitous in biological membranes. Recently, the interest in cationic lipids has surged because of their potential as non-viral transfection vectors. In order to utilize cationic lipids in transfer of nucleic acids and to elucidate the role of charged lipids in cellular membranes in general, their complex interactions within the membrane and with the molecules in the surrounding media need to be thoroughly characterized. Yet, even interactions between monovalent counter-ions and charged lipids are inadequately understood. We studied the interactions of the cationic gemini surfactant (2R,3R)-2,3-dimethoxy-1,4- bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide (RR-1) with chloride, bromide, fluoride, and iodide as counter-ions by differential scanning calorimetry and Langmuir balance. Chloride interacts avidly with RR-1, efficiently condensing the monolayer, decreasing the collapse pressure, and elevating the main transition temperature. With bromide and iodide clearly different behaviour was observed, indicating specific interactions between RR-1 and these counter-ions. Moreover, with fluoride as a counter-ion and in pure water identical results were obtained, demonstrating inefficient electrostatic screening of the headgroups of RR-1 and suggesting fluoride being depleted on the surface of RR-1 membranes.

  4. Countering Children's Sugared Food Commercials: Do Rebuttals Help?

    Science.gov (United States)

    Kaufman, Lois; Sandman, Peter M.

    To assist the Federal Trade Commission (FTC) in policy making decisions concerning sugared food advertisements on television, a study was conducted to assess the effects on children of counter advertisements and disclaimers as a means of lessening the undesirable impact of sugared food ads. Approximately 1,200 children, aged 5 to 10 years,…

  5. Counter gradient diffusion in a plane wall jet

    Science.gov (United States)

    Ramesh, O.; Dhamotharan, V.

    2015-11-01

    Turbulent wall-jets are important in a variety of applications such as the Coanda effect for boundary layer separation control, film-cooling applications in a jet engine etc., One of the important features of a wall jet is the existence of a region of counter gradient diffusion of momentum. The counter-gradient region is a sort of pathological situation for RANS based turbulence models as they would not be able to predict this region. In this study we show from our experiments in a wall jet the counter-gradient region of diffusion can be understood from simple structural models for a wall jet eddy. Towards this flow visualization and hotwire measurements have been performed. It is seen from the smoke flow visualizations that the outward portion of the flow is backward leaning i.e. in the upstream direction. This is consistent with the orientation of eddy structure obtained from two-point correlation measurements. A building block eddy of a wall jet is proposed that has aspects of a boundary layer eddy in the inner wall region and a jet eddy in the outer region. It is argued by a simple vortex dynamics model that the counter-gradient region occurs due to the influence of the jet eddies in the near-wall region.

  6. Timing properties of parallel plate avalanche counters with light particles

    International Nuclear Information System (INIS)

    We have operated a 15 cm2 parallel plate avalanche counter (PPAC) with protons and α-particles. Time resolution of 140 psec (FWHM) has been measured with 5.5 MeV α-particles at 30 Torr of isobutane. (author)

  7. Stress and use of over-the-counter analgesics

    DEFF Research Database (Denmark)

    Koushede, Vibeke Jenny; Ekholm, Ola; Holstein, Bjørn E; Andersen, Anette; Hansen, Ebba Holme

    2011-01-01

    To examine the prevalence of over-the-counter analgesic (OTCA) use and perceived stress among 25 to 44-year-old men and women from 1994 to 2005; to examine the association between stress and OTCA use over time, and to explore whether the association attenuates when controlled by stress...

  8. BABYSCAN - a whole body counter for small children in Fukushima

    CERN Document Server

    Hayano, Ryugo S; Bronson, Frazier L; Oginni, Babatunde; Muramatsu, Isamu

    2014-01-01

    BABYSCAN, a whole body counter for small children with a detection limit for $^{137}$Cs of better than 50 Bq/body, was developed, and the first unit has been installed at a hospital in Fukushima, to help families with small children who are very much concerned about internal exposures. The design principles, implementation details and the initial operating experience are described.

  9. Improving SHA-1 counter-cryptanalysis using unavoidable conditions

    NARCIS (Netherlands)

    Shumow, D.; Stevens, M.M.J.

    2015-01-01

    The concept of counter-cryptanalysis and a collision detection algorithm that detects whether a given single message was constructed using a cryptanalytic collision attack on MD5 or SHA-1 was presented by Stevens at CRYPTO 2013. It was shown that collision detection is not only possible but also pra

  10. Rapid Scan Humidified Growth Cloud Condensation Nuclei Counter

    Energy Technology Data Exchange (ETDEWEB)

    Gregory L. Kok; Athanasios Nenes

    2013-03-13

    This research focused on enhancements to the streamwise thermal gradient cloud condensation nuclei counter to support the rapid scan mode and to enhance the capability for aerosol humidified growth measurements. The research identified the needs for flow system modifications and range of capability for operating the conventional instrument in the rapid scan and humidified growth modes.

  11. Energy response research of GJ4401 γ counter tube

    International Nuclear Information System (INIS)

    Principles of energy response of new G-M counter tube named GJ4401 γ are discussed. The measure which uses a tin and lead alloy as the shield is advanced. There are some simple computing attenuation of the absorption edges, and the concept for improving its energy response is presented

  12. Counter Rotating Open Rotor Animation using Particle Image Velocimetry

    OpenAIRE

    Roosenboom, E.W.M.; Schroeder, A.; Geisler, R.; Pallek, D.; Agocs, J.; Neitzke, K.-P.

    2011-01-01

    This article describes the two accompanying fluid dynamics videos for the "Counter rotating open rotor flow field investigation using stereoscopic Particle Image Velocimetry" presented at the 64th Annual Meeting of the APS Division of Fluid Dynamics in Baltimore, Maryland, November 20-22, 2011.

  13. 21 CFR 866.2170 - Automated colony counter.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Automated colony counter. 866.2170 Section 866.2170 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... purposes to determine the number of bacterial colonies present on a bacteriological culture...

  14. Central counterparties for over-the-counter derivatives

    OpenAIRE

    Stephen G. Cecchetti; Jacob Gyntelberg; Marc Hollanders

    2009-01-01

    Wider use of central counterparties (CCPs) for over-the-counter derivatives has the potential to improve market resilience by lowering counterparty risk and increasing transparency. However, CCPs alone are not sufficient to ensure the resilience and efficiency of derivatives markets.

  15. Stellar counter-rotation in lenticular galaxy NGC 448

    CERN Document Server

    Katkov, Ivan Yu; Chilingarian, Igor V; Uklein, Roman I; Egorov, Oleg V

    2016-01-01

    The counter-rotation phenomenon in disc galaxies directly indicates a complex galaxy assembly history which is crucial for our understanding of galaxy physics. Here we present the complex data analysis for a lenticular galaxy NGC 448, which has been recently suspected to host a counter-rotating stellar component. We collected deep long-slit spectroscopic observations using the Russian 6-m telescope and performed the photometric decomposition of Sloan Digital Sky Survey (SDSS) archival images. We exploited (i) a non-parametric approach in order to recover stellar line-of-sight velocity distributions and (ii) a parametric spectral decomposition technique in order to disentangle stellar population properties of both main and counter-rotating stellar discs. Our spectral decomposition stays in perfect agreement with the photometric analysis. The counter-rotating component contributes $\\approx$30 per cent to the total galaxy light. We estimated its stellar mass to be $9.0^{+2.7}_{-1.8}\\cdot10^{9}M_\\odot$. The radia...

  16. Cationic lipid membranes-specific interactions with counter-ions

    International Nuclear Information System (INIS)

    Lipids bearing net electric charges in their hydrophilic headgroups are ubiquitous in biological membranes. Recently, the interest in cationic lipids has surged because of their potential as non-viral transfection vectors. In order to utilize cationic lipids in transfer of nucleic acids and to elucidate the role of charged lipids in cellular membranes in general, their complex interactions within the membrane and with the molecules in the surrounding media need to be thoroughly characterized. Yet, even interactions between monovalent counter-ions and charged lipids are inadequately understood. We studied the interactions of the cationic gemini surfactant (2R,3R)-2,3-dimethoxy-1,4- bis(N-hexadecyl-N,N-dimethylammonium)butane dibromide (RR-1) with chloride, bromide, fluoride, and iodide as counter-ions by differential scanning calorimetry and Langmuir balance. Chloride interacts avidly with RR-1, efficiently condensing the monolayer, decreasing the collapse pressure, and elevating the main transition temperature. With bromide and iodide clearly different behaviour was observed, indicating specific interactions between RR-1 and these counter-ions. Moreover, with fluoride as a counter-ion and in pure water identical results were obtained, demonstrating inefficient electrostatic screening of the headgroups of RR-1 and suggesting fluoride being depleted on the surface of RR-1 membranes

  17. Insubordinate Spaces for Intemperate Times: Countering the Pedagogies of Neoliberalism

    Science.gov (United States)

    Tomlinson, Barbara; Lipsitz, George

    2013-01-01

    Henry A. Giroux argues that countering the disasters of neoliberalism requires facing "the challenge of developing a politics and pedagogy that can serve and actualize a democratic notion of the social" (2011). The authors suggest that Immanuel Wallerstein's notion of "middle-run" temporality (2008) and Stuart Hall's discussion of "middle-level"…

  18. A silica aerogel Cerenkov counter with diffusing walls

    International Nuclear Information System (INIS)

    A Cerenkov counter with an active area of 28 x 80 cm2, using silica aerogel with a refractive index 1.03 is described. The light is collected by diffuse reflecting walls. With 9 cm of aerogel 9 photoelectrons is obtained for β = 1 particles. Scintillations in the walls of the detector amounts to a maximum of 0.07 photoelectrons. (orig.)

  19. BABYSCAN: a whole body counter for small children in Fukushima

    International Nuclear Information System (INIS)

    BABYSCAN, a whole body counter for small children with a detection limit for 137Cs of better than 50 Bq/body, was developed, and the first unit has been installed at a hospital in Fukushima, to help families with small children who are very much concerned about internal exposures. The design principles, implementation details and the initial operating experience are described. (paper)

  20. 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. PMID:23654033

  1. 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

  2. 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

  3. People's practices: Exploring contestation, counter-development, and rural livelihoods. Cases from Muktinagar, Bangladesh

    NARCIS (Netherlands)

    Huq, H.

    2000-01-01

    People's Practices: Exploring contestation, Counter - development, and rural livelihoodsThe central problems explored in the thesis concern the vulnerability of disadvantaged local people, especially women, and their agency; development discourses and counter-development processes; livelihood strate

  4. Waste Management Practices among Counter Service Restaurants in Batangas City, Philippines

    OpenAIRE

    Billy T. Festijo; Nomer Yuzon

    2013-01-01

    The study looked into the extent of the proper waste management of the counter service restaurants in Batangas City, Philippines. The waste management of counter service restaurant highlighted on reducing the food establishment demand for virgin raw materials through increasing waste prevention and recycling. The problem encountered of the counter service restaurant agrees on the government policy that was implementing in our country. The proposed plan of action will help the counter service ...

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    The influence of external γ radiation on the process of 71Ge-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

  7. Influence of higher valent ions on flexible polyelectrolyte stiffness and counter-ion distribution

    Science.gov (United States)

    Chremos, Alexandros; Douglas, Jack F.

    2016-04-01

    We investigate the influence of counter-ion valency on the flexibility of highly charged flexible polymer chains using molecular dynamics simulations that include both salt and an explicit solvent. As observed experimentally, we find that divalent counter-ions greatly reduce the chain persistence length, lp, in comparison with monovalent counter-ions. On the other hand, polyelectrolyte chains having trivalent counter-ions adopt a much more compact conformation than polyelectrolytes having monovalent and divalent counter-ions. We demonstrate that the tendency of polyelectrolyte chains to become deformed by proximal high valence counter-ions is due to chain "coiling" around the counter-ions. In particular, we find that the number of contacts that the proximal counter-ions have with the polyelectrolyte dictates the extent of chain coiling. This ion-binding induced coiling mechanism influences not only the conformational properties of the polyelectrolyte, but also the counter-ion distribution around the chain. Specifically, we find that higher valent counter-ions lead both to a counter-ion enrichment in close proximity to the polyelectrolyte and to a significant reduction in the spatial extent of the diffuse counter-ion cloud around the polyelectrolyte.

  8. Influence of higher valent ions on flexible polyelectrolyte stiffness and counter-ion distribution.

    Science.gov (United States)

    Chremos, Alexandros; Douglas, Jack F

    2016-04-28

    We investigate the influence of counter-ion valency on the flexibility of highly charged flexible polymer chains using molecular dynamics simulations that include both salt and an explicit solvent. As observed experimentally, we find that divalent counter-ions greatly reduce the chain persistence length, lp, in comparison with monovalent counter-ions. On the other hand, polyelectrolyte chains having trivalent counter-ions adopt a much more compact conformation than polyelectrolytes having monovalent and divalent counter-ions. We demonstrate that the tendency of polyelectrolyte chains to become deformed by proximal high valence counter-ions is due to chain "coiling" around the counter-ions. In particular, we find that the number of contacts that the proximal counter-ions have with the polyelectrolyte dictates the extent of chain coiling. This ion-binding induced coiling mechanism influences not only the conformational properties of the polyelectrolyte, but also the counter-ion distribution around the chain. Specifically, we find that higher valent counter-ions lead both to a counter-ion enrichment in close proximity to the polyelectrolyte and to a significant reduction in the spatial extent of the diffuse counter-ion cloud around the polyelectrolyte. PMID:27131566

  9. Effect of the troposphere on surface neutron counter measurements

    CERN Document Server

    Aplin, K L; Bennett, A J

    2005-01-01

    Surface neutron counter data are often used as a proxy for atmospheric ionisation from cosmic rays in studies of extraterrestrial effects on climate. Neutron counter instrumentation was developed in the 1950s and relationships between neutron counts, ionisation and meteorological conditions were investigated thoroughly using the techniques available at the time; the analysis can now be extended using modern data. Whilst surface neutron counts are shown to be a good proxy for ionisation rate, the usual meteorological correction applied to surface neutron measurements, using surface atmospheric pressure, does not completely compensate for tropospheric effects on neutron data. Residual correlations remain between neutron counts, atmospheric pressure and geopotential height, obtained from meteorological reanalysis data. These correlations may be caused by variations in the height and temperature of the atmospheric layer at ~100hPa. This is where the primary cosmic rays interact with atmospheric air, producing a c...

  10. Effect of counter current gas phase on liquid film

    Institute of Scientific and Technical Information of China (English)

    Shujuan LUO; Huaizhi LI; Weiyang FEI; Yundong WANG

    2009-01-01

    Liquid film flow is very important in many industrial applications. However, there are few reports about its characteristics on structured packings. Therefore, in this paper, liquid film phenomena were investigated experimentally to exploit new approaches for intensifying the performance of the structured packings. All experiments were performed at room temperature. Water and air were the working fluids. The effect of counter current gas phase on the liquid film was taken into consideration. A high speed camera, a non-intrusive measurement technique, was used. It is shown that both liquid and gas phases have strong effects on film characteristics. In the present work, liquid film width increased by 57% because of increasing liquid flow rate, while it decreased by 25% resulting from the counter current gas phase.

  11. Proposition of Unique Pumping System with Counter-Rotating Mechanism

    Directory of Open Access Journals (Sweden)

    Toshiaki Kanemoto

    2004-01-01

    Full Text Available Turbo-pumps have weak points, such as when the pumping operation becomes unstable in the rising portion of the head characteristics and/or the cavitation occurs under the intolerably low suction head. To overcome both weak points simultaneously, this article proposes a unique pumping system with counter-rotating mechanism, which consists of two stage impellers and a peculiar motor with double rotors. The front and the rear impellers are driven by the inner and the outer rotors of the motor, respectively, keeping the relative rotational speed constant and counter-balancing the rotational torque. Such driving conditions not only smartly improve the unstable performance at lower discharge, but also suppress the cavitation at higher discharge, in the optimum cooperation with the impeller works and the rotor outputs.

  12. Oscillatory Counter-Centrifugation: Effects of History and Lift Forces

    Science.gov (United States)

    Nadim, Ali

    2014-11-01

    This work is co-authored with my doctoral student Shujing Xu and is dedicated to the memory of my doctoral advisor Howard Brenner who enjoyed thought experiments related to rotating systems. Oscillatory Counter-Centrifugation refers to our theoretical discovery that within a liquid-filled container that rotates in an oscillatory manner about a fixed axis as a rigid body, a suspended particle can be made to migrate on average in the direction opposite to that of ordinary centrifugation. That is, a heavy (or light) particle can move toward (or away from) the rotation axis, when the frequency of oscillations is high enough. In this work we analyze the effects of the Basset history force and the Saffman lift force on particle trajectories and find that the counter-centrifugation phenomenon persists even when these forces are active.

  13. Large area spark counters with fine time and position resolution

    International Nuclear Information System (INIS)

    Spark counters trace their history back over three decades but have been used in only a limited number of experiments. The key properties of these devices include their capability of precision timing (at the sub 100 ps level) and of measuring the position of the charged particle to high accuracy. At SLAC we have undertaken a program to develop these devices for use in high energy physics experiments involving large detectors. A spark counter of size 1.2 m x 0.1 m has been constructed and has been operating continuously in our test setup for several months. In this talk I will discuss some details of its construction and its properties as a particle detector. 14 references

  14. Identification of irradiated spices with aid of scintillation counter

    International Nuclear Information System (INIS)

    The aim off the work was to determine how one can identify gamma-irradiated spices with aid of a scintillation counter (LKB/Wallac 1219 RackBeta Spectral) by chemiluminescence measurements. Even though scintillation counters are more sensitive than real luminometers they have not been capable in identifying the irradiated spices after contact with photosensitizer like luminol, isoluminol and lucigenin presumably because the actual chemiluminescence reaction took place before the sample vial reached the measuring range. Whereas it was noticed that the identification of pure, dry allspice, black pepper, white peppar and cardemom was possible without any solutions when there were also present similar unirradiated spices. The identification was possible even after 23 weeks duration depending on the dose of the irradiation (10 kGy or 50 kGy) and the weight of the samples (1 g or 9 g). The duration of the investigation was 23 weeks

  15. Using tissue equivalent proportional counters to determine dose equivalent

    International Nuclear Information System (INIS)

    Tissue equivalent proportional counters (TEPCs) have been used in the laboratory for over 30 years to determine neutron dose in mixed radiation fields, but they are seldom used by operational health physicists. But a number of TEPC-based instruments are being developed in Europe and in the United States. The purpose of this paper is: to introduce operational health physicists to tissue equivalent proportional counters, to examine some of the algorithms used to convert data from TEPCs into dose equivalent, to examine how TEPC measurements meet the requirements of DOE Order 5480.11 (DOE 1988) and 10CFR20, and to examine some of the TEPC-based instruments that are available. Many operational health physicists are not familiar with the concept of microdosimetry and the specialized terms that are used in analyzing the data from TEPCs, so a brief discussion is included. At present, quality factors are defined in terms of linear energy transfer, but TEPCs measure lineal energy

  16. COUNTERING RADICALISATION ACROSS EUROPE – THE PIONEERING ISDEP PROJECT

    Directory of Open Access Journals (Sweden)

    Rozila Kana

    2015-12-01

    Full Text Available The changing landscape of the global terrorism threat coupled with increasing concern about home grown extremism means that the need to tackle the root causes of radicalisation across the European Union has never been greater. The pathway to violent extremism and terrorism is, however, undeniably complex. Frontline practitioners working with those vulnerable to radicalisation need to have the right tools to allow them to recognise, respond to and challenge ideologies and narratives associated with any form of terrorism. A pioneering EU Commission funded project is the first of its kind designed to offer consistency around, and increase awareness of, counter radicalisation specifically for frontline practitioners. Improving Security by Democratic Participation (ISDEP is a two year programme based on the EU Commission’s Prevent strand of the Counter Terrorism Strategy. Training themes focus on helping practitioners to identify the influences and vulnerabilities that shape an individual’s thought processes towards violent extremism.

  17. Improving Viral Protease Inhibitors to Counter Drug Resistance.

    Science.gov (United States)

    Kurt Yilmaz, Nese; Swanstrom, Ronald; Schiffer, Celia A

    2016-07-01

    Drug resistance is a major problem in health care, undermining therapy outcomes and necessitating novel approaches to drug design. Extensive studies on resistance to viral protease inhibitors, particularly those of HIV-1 and hepatitis C virus (HCV) protease, revealed a plethora of information on the structural and molecular mechanisms underlying resistance. These insights led to several strategies to improve viral protease inhibitors to counter resistance, such as exploiting the essential biological function and leveraging evolutionary constraints. Incorporation of these strategies into structure-based drug design can minimize vulnerability to resistance, not only for viral proteases but for other quickly evolving drug targets as well, toward designing inhibitors one step ahead of evolution to counter resistance with more intelligent and rational design. PMID:27090931

  18. MCP-PMT development for Belle-II TOP counter

    Science.gov (United States)

    Inami, K.

    We have developed a multiple-anode square-shape MCP-PMT for the Belle-II Time-Of-Propagation (TOP) counter. This detector is a hybrid cherenkov ring imaging and timing detector for particle identification in the barrel region of the upgraded detector. The Belle-II experiment will operate at high event rates and needs to withstand the correspondingly high background environment. MCP-PMT's have demonstrated excellent single photon timing resolution. However, the lifetime of photocathode is a known issue. Recently, we successfully improved the lifetime of a square-shape MCP-PMT by a factor of about 10, which is adequate for estimates of the nominal Belle-II background rates in the TOP counter. We have also developed a new MCP-PMT with Hamamatsu photonics, that adopts a super bialkali photocathode. Currently a peak quantum effciency of 28% for 400 nm photons has been achieved.

  19. A Chip of Counter and Parallel Interface Port Using FPGA

    International Nuclear Information System (INIS)

    A chip contained two 16 bit counters and parallel interface port has been constructed by using Field Programmable Gate Array (FPGA) made by Altera. One of the aim of this activity was to replace the interfacing card which were using Programmable Logic Device (PLD) and others supporting components placed on personal computer expansion slot ISA or EISA, with a compatible Chip. The result was a 44 pin Chip with a single 5 V supply. The experiment test showed that the input output ports were working properly. The Simulation timing showed suitably as the requirement. The Chip was designed for the instruments which needed a counter, timer and connected to the computer as data acquisition and control. The advantage of this Chip was the compatibility of the pin parallel port standard, it can be connected with any computers type. (author)

  20. Development of position sensitive gas counter with delay line readout

    International Nuclear Information System (INIS)

    The position counter with delay line read out was developed using commercially available delay line chips. Their counting rate capability was evaluated with Monte Carlo simulation and compared with the case of charge division method. The delay line method is expected to gain advantage over the charge division method. The 25 cm prototype of the counter was tested in RCNP and the usefulness for the focal plane detector is shown. The 1.2 m one was developed and the performance is measured with X-ray source in proportional mode and SQS mode. The best position resolution obtained was 1 mm with 25 μm anode wire. The best position resolutions obtained with 50 μm anode wire in proportional and SQS mode were 1.4 mm and 1.7 mm, respectively. (J.P.N.)

  1. Effectiveness of Counter-Trafficking Response in Albania

    Directory of Open Access Journals (Sweden)

    Meçe Merita H.

    2016-07-01

    Full Text Available Human trafficking is a new phenomenon of Albanian post-socialist society which significantly increased during the difficult years of its transformation from centralized state-led economy to market economy. Both economic and political instability contributed to its size, nature and multiple dynamics. Drawing on a rights-based approach to human trafficking, this paper examines the effectiveness of the counter-trafficking response of the Albanian government with a special emphasis on prevention, protection and prosecution. Using secondary data and reviewing various country strategic documents, it highlights a range of weaknesses and challenges which have hindered its effectiveness over years. It concludes that successful and effective counter-trafficking response requires well rounded and coordinated gender sensitive, victim-centred, holistic and human rights-based efforts. Combined with adequate law enforcement, they will sustainably tackle the full spectrum of this problem.

  2. Spray deposited titanium oxide thin films as passive counter electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, P.S.; Mujawar, S.H.; Inamdar, A.I.; Patil, P.S. [Thin Film Materials Laboratory, Department of Physics, Shivaji University, Kolhapur-416004 (India); Deshmukh, H.P. [Bharati Vidyapeeth Deemed University, Yashwantrao Mohite College, Pune-411038 (India)

    2007-02-15

    Titanium dioxide (TiO{sub 2}) thin films were deposited from methanolic solution onto fluorine doped tin oxide coated conducting glass substrates by spray pyrolysis technique. The electrochemical properties of TiO{sub 2} thin films were investigated using cyclic voltammetry, chronoamperometry, chronocoulometry and iono-optical studies, in 0.1N H{sub 2}SO{sub 4} electrolyte. Performance of the films deposited at three different substrate temperatures, viz. 350, 400 and 450 C is discussed in view of their utilization in electrochromic devices, as counter electrode. The magnitude of charge storage capacity, Q/t (4.75-6.13 x 10{sup -3} mC/(cm{sup 2} nm)) and colouration efficiency (3.2-4.3 cm{sup 2}/mC) of TiO{sub 2} rank these films among the promising counter electrodes in electrochromic devices. (author)

  3. The suppression of destructive sparks in parallel plate proportional counters

    International Nuclear Information System (INIS)

    The authors find that high energy background events produce localised sparks in parallel plate counters when operated in the proportional mode. These sparks increase dead-time and lead to degradation ranging from electrode damage to spurious pulsing and continuous breakdown. The problem is particularly serious in low energy photon detectors for X-ray astronomy which are required to have lifetimes of several years in the high radiation environment of space. For the parallel plate imaging detector developed for the European X-ray Observatory Satellite (EXOSAT) they investigate quantitatively the spark thresholds, spark rates and degradation processes. They discuss the spark mechanism, pointing out differences from the situation in spark chambers and counters. They show that the time profile of the sparks allows them to devise a spark suppression system which reduces the degradation rate by a factor of ''200

  4. Fully Countering Trusting Trust through Diverse Double-Compiling

    CERN Document Server

    Wheeler, David A

    2010-01-01

    An Air Force evaluation of Multics, and Ken Thompson's Turing award lecture ("Reflections on Trusting Trust"), showed that compilers can be subverted to insert malicious Trojan horses into critical software, including themselves. If this "trusting trust" attack goes undetected, even complete analysis of a system's source code will not find the malicious code that is running. Previously-known countermeasures have been grossly inadequate. If this attack cannot be countered, attackers can quietly subvert entire classes of computer systems, gaining complete control over financial, infrastructure, military, and/or business systems worldwide. This dissertation's thesis is that the trusting trust attack can be detected and effectively countered using the "Diverse Double-Compiling" (DDC) technique, as demonstrated by (1) a formal proof that DDC can determine if source code and generated executable code correspond, (2) a demonstration of DDC with four compilers (a small C compiler, a small Lisp compiler, a small malic...

  5. Performance of Scintillator Counters with Silicon Photomultiplier Readout

    CERN Document Server

    Artikov, A; Chokheli, D; Davydov, Yu I; Dukes, E C; Ehrlich, R; Francis, K; Frank, M J; Glagolev, V; Hansen, S; Hocker, A; Oksuzian, Y; Rubinov, P; Song, E; Uzunyan, S; Wu, Y

    2015-01-01

    The performance of scintillator counters with embedded wavelength-shifting fibers has been measured in the Fermilab Meson Test Beam Facility using 120 GeV protons. The counters were extruded with a titanium dioxide surface coating and two channels for fibers at the Fermilab NICADD facility. Each fiber end is read out by a 2*2 mm^2 silicon photomultiplier. The signals were amplified and digitized by a custom-made front-end electronics board. Combinations of 5*2 cm^2 and 6*2 cm^2 extrusion profiles with 1.4 and 1.8 mm diameter fibers were tested. The design is intended for the cosmic-ray veto detector for the Mu2e experiment at Fermilab. The light yield as a function of the transverse and longitudinal position of the beam will be given.

  6. A compact gas-filled avalanche counter for DANCE

    International Nuclear Information System (INIS)

    A compact gas-filled avalanche counter for the detection of fission fragments was developed for a highly segmented 4π γ-ray calorimeter, namely the Detector for Advanced Neutron Capture Experiments located at the Lujan Center of the Los Alamos Neutron Science Center. It has been used successfully for experiments with 235U, 238Pu, 239Pu, and 241Pu isotopes to provide a unique signature to differentiate the fission from the competing neutron-capture reaction channel. It was also used to study the spontaneous fission in 252Cf. The design and performance of this avalanche counter for targets with extreme α-decay rate up to ∼2.4×108/s are described.

  7. Scintillation counters in modern high-energy physics experiments (Review)

    Science.gov (United States)

    Kharzheev, Yu. N.

    2015-07-01

    Scintillation counters (SCs) based on organic plastic scintillators (OPSs) are widely used in modern high-energy physics (HEP) experiments. A comprehensive review is given to technologies for production of OPS strips and tiles (extrusion, injection molding, etc.), optical and physical characteristics of OPSs, and methods of light collection based on the use of wavelength-shifting (WLS) fibers coupled to multipixel vacuum and silicon PMs. Examples are given of the use of SCs in modern experiments involved in the search for quarks and new particles, including the Higgs boson (D0, CDF, ATLAS, CMS), new states of matter (ALICE), CP violation (LHCb, KLOE), neutrino oscillations (MINOS, OPERA), and cosmic particles in a wide mass and energy interval (AMS-02). Scintillation counters hold great promise for future HEP experiments (at the ILC, NICA, FAIR) due to properties of a high segmentation, WLS fiber light collection, and multipixel silicon PMT readout.

  8. Uraniferous minerals heap leaching process by counter techique

    International Nuclear Information System (INIS)

    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 U3O8 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 U3O8/1 and 3 g H2SO4/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 m3/t. The average efficiency was of 77% of recovered *uranium. (author)

  9. A large silica aerogel Cherenkov counter for SKS

    International Nuclear Information System (INIS)

    A large silica aerogel Cherenkov counter has been constructed as a kaon trigger counter to veto pions of 0.7 GeV/c for experiments studying hypernuclei by the (π+, K+) reaction with the superconducting kaon spectrometer (SKS) at the KEK 12-GeV proton synchrotron. It features a large single diffusion box with a sensitive area of 140 cm x 120 cm and a thickness of about 40 cm. Special attention was paid to the shape of a reflector in order to achieve uniform efficiency over the sensitive area. A mean photoelectron number of anti Ne = 6-7 was obtained for 0.72 GeV/c (β = 0.984) pions with a refractive index of 1.06. (orig.)

  10. Scintillator fiber optic long counter for neutron detection

    International Nuclear Information System (INIS)

    A fiber optic long counter for neutron detection has been developed which uses 30 cm long, 6Li-loaded Tb3+-doped scintillator fiber optics as the detection element. The element is surrounded by polyethylene moderator and configured to allow neutrons to enter from one direction. The penetration depth of thermalization into the moderator is related to incident neutron energy. By determining the absorption position of the thermalized neutron along the fiber, the incident energy of the neutron can be estimated. The absorption position is measured by determining the differential signal collected by photomultiplier tubes at each end of the fiber element. The system is capable of low resolution neutron spectroscopy while retaining the flat response of conventional long counters. (orig.)

  11. A compact gas-filled avalanche counter for DANCE

    Science.gov (United States)

    Wu, C. Y.; Chyzh, A.; Kwan, E.; Henderson, R. A.; Gostic, J. M.; Carter, D.; Bredeweg, T. A.; Couture, A.; Jandel, M.; Ullmann, J. L.

    2012-12-01

    A compact gas-filled avalanche counter for the detection of fission fragments was developed for a highly segmented 4π γ-ray calorimeter, namely the Detector for Advanced Neutron Capture Experiments located at the Lujan Center of the Los Alamos Neutron Science Center. It has been used successfully for experiments with 235U, 238Pu, 239Pu, and 241Pu isotopes to provide a unique signature to differentiate the fission from the competing neutron-capture reaction channel. It was also used to study the spontaneous fission in 252Cf. The design and performance of this avalanche counter for targets with extreme α-decay rate up to ˜2.4×108/s are described.

  12. A compact gas-filled avalanche counter for DANCE

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C.Y., E-mail: wu24@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Chyzh, A.; Kwan, E.; Henderson, R.A.; Gostic, J.M.; Carter, D. [Lawrence Livermore National Laboratory, Livermore, CA 94551 (United States); Bredeweg, T.A.; Couture, A.; Jandel, M.; Ullmann, J.L. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2012-12-01

    A compact gas-filled avalanche counter for the detection of fission fragments was developed for a highly segmented 4{pi} {gamma}-ray calorimeter, namely the Detector for Advanced Neutron Capture Experiments located at the Lujan Center of the Los Alamos Neutron Science Center. It has been used successfully for experiments with {sup 235}U, {sup 238}Pu, {sup 239}Pu, and {sup 241}Pu isotopes to provide a unique signature to differentiate the fission from the competing neutron-capture reaction channel. It was also used to study the spontaneous fission in {sup 252}Cf. The design and performance of this avalanche counter for targets with extreme {alpha}-decay rate up to {approx}2.4 Multiplication-Sign 10{sup 8}/s are described.

  13. Flooding in counter-current two-phase flow

    International Nuclear Information System (INIS)

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

  14. A position dependent particle counter using microchannel plates, ch. 2

    International Nuclear Information System (INIS)

    The use of cascaded channel plates as position dependent particle counters is described. A one- and two-dimensional dissection technique, based on the spread of charge between channel plate and collector, is used. The one-dimensional detector is developed for use in atomic scattering experiments. The system is tested by measuring the relative, total differential scattering cross section of electrons by helium between 1deg and 3-4 deg

  15. Counter-Memories of the Namibian Independence War from Kaoko

    OpenAIRE

    Bleckmann, Laura

    2011-01-01

    Laura E. Bleckmann, IARA (Institute for Anthropological Research in Africa), Leuven, Belgium Counter-Memories of the Namibian Independence War from Kaoko Abstract This paper is devoted to the memory productions of former South African combatants and police men from Kaoko in northern Namibia. It is just 20 years ago that the Independence War, in which also Kaoko had served as a battleground, was terminated and Namibia achieved its independence with the intervention of the UN (United ...

  16. MEASUREMENTS WITH TRAFFIC COUNTER IN CITY LOGISTICS IN LJUBLJANA

    OpenAIRE

    Lorenzo Ros McDonnell; Sabrina Trafela; Gergely Hodosi; Attila Bodis

    2013-01-01

    City supply is one of the most highlighted topics in modern logistics. The main goal of research activities is consolidation and reduction of transport needs, lowering energy consumption, air and noise pollution, etc. The goal of our Tracy R&D Project is to invent an appropriate, flexible and low-cost traffic counter tool to support scientific research, decision making process and evaluation of actions made by city authorities. In our essay we present a possible application of Tracy tool in t...

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

    International Nuclear Information System (INIS)

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

  18. Large scale test of wedge shaped micro strip gas counters

    International Nuclear Information System (INIS)

    In order to check the system aspects of the forward-backward MSGC tracker designed for the future CMS experiment at LHC, 38 trapezoidal MSGC counters assembled in six multi-substrates detector modules were built and exposed to a muon beam at the CERN SPS. Results on the gain uniformity along the wedge-shaped strip pattern and across the detector modules are shown together with measurements of the detection efficiency and the spatial resolution

  19. A ‘criminal personas’ approach to countering criminal creativity

    OpenAIRE

    Hilton, Kevin; Irons, Alastair

    2006-01-01

    This paper describes a pilot study of a ‘criminal personas’ approach to countering criminal creativity. The value of the personas approach has been assessed by comparing the identification of criminal opportunity, through ‘traditional’ brainstorming and then through ‘criminal personas’ brainstorming The method involved brainstorm sessions with Computer Forensics Practitioners and with Product Designers, where they were required to generate criminal scenarios, select the most serious criminal ...

  20. The Securitization Theory and Counter Terrorism in Indonesia

    OpenAIRE

    SENIWATI, SENIWATI

    2014-01-01

    The counter terrorism in Indonesia applies the theory of securitization. The theory of securitization is the new ways of counterterrorism and security studies. This article explores the emergence of securitization the end of the post-Cold War, securitization in security, securitization in international studies and securitization in fighting terrorism in Indonesia. Security studies emerged the end of the Cold War with focus on military and political deterrence from the Western and the Soviet U...

  1. Counter-based Traffic Management Scheme for Vehicular Networks

    OpenAIRE

    Tarun Prakash; Ritu Tiwari

    2011-01-01

    Vehicles traffic congestion on the road is reflected as delays while traveling. This congestion has a number of negative effects such as energy consumption, wastage of time and increased tailpipes emission of idling vehicles probably bad for our health. Vehicular congestion has become the serious problem and it is getting worse day by day as the growth of the vehicles significantly increased. In this paper, we proposed a novel counter approach to avoid such vehicular congestion on the road. W...

  2. An Over-the-Counter Approach to the FOREX Market

    OpenAIRE

    Geromichalos, Athanasios; Jung, Kuk Mo

    2015-01-01

    The FOREX market is an over-the-counter market (in fact, the largest in the world) characterized by bilateral trade, intermediation, and significant bid-ask spreads. The existing international macroeconomics literature has failed to account for these stylized facts largely due to the fact that it models the FOREX as a standard Walrasian market, therefore overlooking some important institutional details of this market. In this paper, we build on recent developments in monetary theory and finan...

  3. An Over-the-Counter Approach to the FOREX Market

    OpenAIRE

    Geromichalos, Athanasios; Jung, Kuk Mo

    2015-01-01

    The FOREX market is an over-the-counter market (in fact, the largest in the world) characterized by bilateral trade, intermediation, and significant bid-ask spreads. The existing international macroeconomics literature has failed to account for these stylized facts largely due to the fact that it models the FOREX as a standard Walrasian market, therefore overlooking some important institutional details of this market. In this paper, we build on recent developments in monetary theory ...

  4. Collective Strategies in Fighting Corruption : Some Intuitions and Counter Intuitions

    OpenAIRE

    Petkoski, D.; Warren, D. E.; Laufer, W. S.

    2009-01-01

    This article explores the plausibility of some intuitions and counter intuitions about the anti-corruption efforts of MDBs and international organizations leveraging the power of the private sector. Regulation of a sizable percentage of global private sector actors now falls into a new area of international governance with innovative institutions, standards, and programs. We wrestle with the role and value of private sector partnerships and available informal and formal social controls. Craft...

  5. Counter-ions at Charged Walls: Two Dimensional Systems

    OpenAIRE

    Samaj, L.; Trizac, E.

    2010-01-01

    We study equilibrium statistical mechanics of classical point counter-ions, formulated on 2D Euclidean space with logarithmic Coulomb interactions (infinite number of particles) or on the cylinder surface (finite particle numbers), in the vicinity of a single uniformly charged line (one single double-layer), or between two such lines (interacting double-layers). The weak-coupling Poisson-Boltzmann theory, which applies when the coupling constant Gamma is small, is briefly recapitulated (the c...

  6. Absolute Measurement of 14C Activity by Internal Proportional Counters

    International Nuclear Information System (INIS)

    14CO22 was obtained by decomposing carbonate with sulphuric acid heated to boiling point, after which it was mixed with CH4 in a reserve flask. Three brass internal proportional counters, differing only in length, were filled with this mixture. The counters were connected to the electronic equipment in the usual arrangement. The equipment dead time was determined by means of a modified two-source method, and the total volume of the equipment was obtained from the isothermic expansion of methane from a flask whose volume, together with that of the counters, had been determined by weighing a water filling. The wall effect was determined by measuring a 14CO2 + CH4 mixture at different pressures and by extrapolation to reciprocal pressure zero value; it was discovered that the wall-effect correction did not differ significantly from zero. The end effect was compensated for by using counters of different lengths so that the difference in plateau slope also did not differ significantly from zero. By the t-test power function it was estimated that the maximal error on a 0.01 significance level, caused by neglecting the wall-effect correction, amounted to ± 0.85% due to the end-effect correction (± 0.62% for the equipment used) having been neglected. The relation between wall, end and discrimination effects is discussed, and, in conclusion, the maximal errors from other sources are estimated; the total maximal error on a 0.01 significance level of the standard solution activity is computed as equal to ± 1.1%. (author)

  7. Performance Evaluation of Four Commercial Optical Particle Counters

    OpenAIRE

    Franco Belosi; Gianni Santachiara; Franco Prodi

    2013-01-01

    The performances of four optical particles counters, Aerosol Spectrometer (Grimm 1.108), Enviro Check (Grimm 1.107), DustMonit and ParticleScan, were evaluated in laboratory tests employing monodisperse aerosol particles. The study focused on how commercial instruments perform during routine measurements respect to OPC scientific understanding, because it is important for users of such instruments to be aware of their limitations. Measurements were performed using aerosol generated by a Mono...

  8. Improving SHA-1 counter-cryptanalysis using unavoidable conditions

    OpenAIRE

    Shumow, D.; Stevens, Marc

    2015-01-01

    The concept of counter-cryptanalysis and a collision detection algorithm that detects whether a given single message was constructed using a cryptanalytic collision attack on MD5 or SHA-1 was presented by Stevens at CRYPTO 2013. It was shown that collision detection is not only possible but also practical and a reference implementation was released. However, there is a significant cost: to detect collision attacks against SHA-1 (respectively MD5) costs the equivalent of hashing the message 15...

  9. Building counter culture: the radical praxis of social movement milieux

    OpenAIRE

    Cox, Laurence

    2011-01-01

    This thesis falls into two parts. The first (chapters one to three) states the problematic of the research, develops a critique of the dominant “social movements” literature as unhelpful for understanding the counter culture and argues that the latter can more effectively be theorised in terms of the implicit theory of social movement found within agency-oriented Western Marxism and socialist feminism. This latter theory is developed as an understanding of movement as direction...

  10. Optimization of a uranyl nitrate passive neutron counter

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Eric Benton [Los Alamos National Laboratory; Bracken, David [Los Alamos National Laboratory; West, James [Los Alamos National Laboratory; Freeman, Corey [Los Alamos National Laboratory; Newell, Matthew R [Los Alamos National Laboratory; Bourret, Steven C [Los Alamos National Laboratory; Rothrock, Richard B [Los Alamos National Laboratory; Ladd - Lively, Jennifer L [ORNL; Schuh, Denise [ORNL

    2010-01-01

    Safeguarding natural uranium as it enters the fuel cycle has become a priority for the safeguards community in recent years. Uranyl nitrate is a material of interest in this endeavor because it is normally a step in the process from converting uranium ores to more concentrated forms like UO{sub 2} and U{sub 3}O{sub 8}. This paper will detail the improvements and design optimizations made for a uranyl nitrate neutron detector. The original design of the detector was based on standard neutron counter designs and featured 2 rings of He-3 tubes fully moderated and shielded from background. Several areas for enhancement were identified after months of testing in three different locations. An operating uranyl nitrate facility was included as one of the test locations. Three significant upgrades to the counter addressed in the redesign were: real time background detection, counter reliability improvements, and optimization of the detector design for the detection of neutrons emitted by the uranyl nitrate flowing through the monitored process pipe. The optimized detector design includes significant electronics upgrades, the ability to detect neutrons (background and signal) with 36 degree spatial resolution around the process pipe for signal and 45 degree spatial resolution for background, inner and outer rings of He-3 tubes for real time background corrections, and notably more reliable cabling. Monte Carlo N-Particle (MCNP) modeling was used to optimize the signal (neutrons from uranyl nitrate in the monitored process pipe) to noise (background neutrons from all sources) ratio of the inner ring of He-3 tubes. Additionally, MCNP modeling maximized noise to signal on the outer ring of He-3 tubes. Details of the detector optimization as well as all the additional detector enhancements will be discussed. The neutron counter will be field tested on the Uranyl Nitrate Calibration Loop Equipment (UNCLE) facility at Oak Ridge National Laboratory (ORNL).

  11. Monte-Carlo Simulation for an Aerogel Cherenkov Counter

    OpenAIRE

    al, Ryuji Suda et

    1997-01-01

    We have developed a Monte-Carlo simulation code for an aerogel \\v Cerenkov Counter which is operated under a strong magnetic field such as 1.5T. This code consists of two parts: photon transportation inside aerogel tiles, and one-dimensional amplification in a fine-mesh photomultiplier tube. It simulates the output photoelectron yields as accurately as 5% with only a single free parameter. This code is applied to simulations for a B-Factory particle-identification system.

  12. Commercial bacterial colony counter for semiautomatic track counting

    International Nuclear Information System (INIS)

    Bacterial colony counters have not been widely used for track counting. However, they do provide an economical alternative to sophisticated optical analyzers for applications that require reproducible track density measurements for large numbers of samples. Simple measurements of size characteristics can be made when there is little need for high resolutions. Such systems are particularly well suited for neutron and alpha dosimetry work, particularly if electrochemical etching or some other track enhancement method has been used. 5 refs., 3 figs

  13. A silica aerogel Cerenkov counter with diffusing walls

    CERN Document Server

    Carlson, P J

    1979-01-01

    A Cerenkov counter with an active area of 28*80 cm/sup 2/, using silica aerogel with a refractive index 1.03 is described. The light is collected by diffuse reflecting walls. With 9 cm of aerogel 9 photoelectrons are obtained for beta =1 particles. Scintillations in the walls of the detector amount to a maximum of 0.07 photoelectrons. (3 refs).

  14. Development of a compact silica aerogel Cherenkov counter

    International Nuclear Information System (INIS)

    A compact silica aerogel Cherenkov counter with fine-mesh type photo-multiplier tubes has been developed to reject e+e- pair created events at a trigger level. The silica aerogel is covered with a highly reflective material to lead emitted Cherenkov photons into the photo-cathodes. The efficiency of e+e- event identification is obtained to be more than 97%. (author)

  15. Catching Seriously Bad Dudes: US Counter-terrorism strategies

    Czech Academy of Sciences Publication Activity Database

    Bernardyová, Alžběta

    2008-01-01

    Roč. 6, č. 7-8 (2008), s. 34-38. ISSN 1214-1720 R&D Projects: GA ČR GA407/07/1395 Institutional research plan: CEZ:AV0Z70280505 Keywords : terrorism * counter- terrorism * US * 9/11 Subject RIV: AD - Politology ; Political Sciences http://www.socioweb.cz/upl/editorial/download/156_socioweb_7_08.pdf

  16. Performance and development of dE/dx counters

    International Nuclear Information System (INIS)

    The performance of existing or nearly completed detectors for particle identification by using the relativistic rise of energy loss will be discussed. Detailed analysis of systematic errors leads finally to large detector systems approaching the ultimate resolution as measured in small test devices. New methods for extracting the information from the counter with the potential of better particles separation than standard dE/dx will be presented. It includes very fine sampling, delta-ray clipping, and cluster counting

  17. Cloud characterization using a particle-counter dropsonde

    Science.gov (United States)

    Ulanowski, Zbigniew; Kaye, Paul Henry; Hirst, Edwin; Wieser, Andreas; Stanley, Warren

    2015-04-01

    Routine meteorological data is obtained in the atmosphere using disposable radiosondes, giving temperature, pressure, humidity and wind speed. Additional measurements are obtained from dropsondes, released from research aircraft. However, a crucial property not yet measured is the size and concentration of atmospheric particulates, including cloud particles or aerosols. Instead, indirect measurements are employed, relying on remote sensing. In addition, research aircraft can be used in situ, but airborne measurements are expensive, and aircraft use is restricted to near-horizontal profiling, which can be a limitation, as phenomena such convection develop in the vertical direction. The Centre for Atmospheric and Instrumentation Research at University of Hertfordshire develops light-scattering instruments for the characterization of aerosols and cloud particles. Recently a range of low-cost, miniature particle counters has been created, intended for use with systems such as disposable balloon-borne radiosondes, dropsondes, or in dense ground-based sensor networks. Versions for different particle size ranges exist. They have been used for vertical profiling of aerosols such as mineral dust or volcanic ash. However, a disadvantage of optical particle counters that sample through a narrow inlet is that they can become blocked, which can happen in a cloud, for example. Hence, a different counter version has been developed, which can have open-path geometry, as the sensing zone is defined optically rather than being delimited by the flow system. This counter is currently being used by the UK Met Office in a ground-based fog monitoring network. It has also been adapted for use with radiosondes or dropsondes. The dropsonde version has been successfully tested by launching it from research aircraft together with the so-called KITsonde, developed at the Karlsruhe Institute of Technology, which determines standard meteorological variables and GPS position for transmission back

  18. Automated platelet counters: a comparative evaluation of latest instrumentation.

    Science.gov (United States)

    Mayer, K; Chin, B; Magnes, J; Thaler, H T; Lotspeich, C; Baisley, A

    1980-08-01

    An extensive evaluation of performance characteristics and accuracy of clinical results for two automated multiparameter whole-blood cell counters (the Coulter Counter Model S-Plus and the Ortho ELT-8) and two single-parameter semiautomated platelet counters (the J. T. Baker MK-4/HC and the Clay-Adams Ultra-Flo 100) is described. Results of comparative assays performed on more than 1,200 clinical specimens are analyzed. These results are compared with manual determinations where appropriate. Particular attention is accorded to the accuracy of platelet counts, especially at abnormal levels below 70 X 10(3)/cu mm, where falsely elevated platelet counts may lead to serious clinical consequences. Both multiparameter instruments yielded accurate results, with the exception of low values reported by the ELT-8 for mean corpuscular volumes above 100 cu micrometer. Results for platelet counts were accurate for most specimens on all four instruments; the ELT-8 was the most reliable (P < 0.01), especially for the critically low counts. Although no instrument is infallible in determining platelet counts at all levels, the authors conclude that addition of platelet-counting capability represents a significant advancement over existing instrumentation. PMID:7405891

  19. Development of engineering quality plan for the RIA counter

    International Nuclear Information System (INIS)

    The engineering of a Radioimmunoassay (RIA) equipment has been performed at the Nuclear Equipment Engineering Center (PRPN). This activity consisted of the engineering of the detector, high voltage (HV) module, Low voltage (L V) module, the single channel analyzer (SCA), window and energy controlling counter, USB communication, and the mechanical system to move the 25 sample vials, which include up/down actuator using DC motors capable of lifting weights of over 2 kg, and a stepper motor moving the sample to the detector. The isotope used is 1-125. Radiation from the samples is counted by the detector, giving 0,5 µs wide pulse which are then transmitted to the SCA and subsequently processed by a computer connected through a Devasys USB counter module. The result of the entry measurement process is plotted in the form of a curve to be compared with a standard curve. To assure the quality of the engineering of this RIA equipment, a quality plan is needed. This quality plan is related to the realization of the RIA counter. This quality plan consist of design, procurement, construction, testing and Assessment. (author)

  20. Morphological aspects of a new type of counter electrojet event

    Directory of Open Access Journals (Sweden)

    R. G. Rastogi

    Full Text Available The study describes the time and space morphologies of a rather new type of counter electrojet event on the basis of data from the excellent chain of magnetic and ionospheric observatories along the Indo-Russian longitude sector. Abnormally large westward currents are observed during almost the whole of the daytime hours on a series of days. These events do not form any vortices in the current system and do not apparently seem to be associated with tidal effects or any solar magnetosphere events or geomagnetic disturbances. The existence of a westward electric field over the equatorial ionosphere has been confirmed by the absence of an equatorial type of sporadic E in the ionograms at Thumba precisely during the periods when ∆H at Trivandrum minus ∆H at Alibag is negative. The equatorial F region anomaly was also absent on the counter electrojet day. Such counter electrojet events during the northern winter months of low solar activity years are suggested to be the result of the modified wind system in the ionosphere associated with stratospheric warming events.

    Key words. Geomagnetism and paleomagnetism (time variations · diurnal to secular · Ionosphere (electric fields and currents; equatorial ionosphere

  1. High-Speed Multipass Coulter Counter with Ultrahigh Resolution.

    Science.gov (United States)

    Edwards, Martin A; German, Sean R; Dick, Jeffrey E; Bard, Allen J; White, Henry S

    2015-12-22

    Coulter counters measure the size of particles in solution by passing them through an orifice and measuring a resistive pulse, i.e., a drop in the ionic current flowing between two electrodes placed on either side of the orifice. The magnitude of the pulse gives information on the size of the particle; however, resolution is limited by variability in the path of the translocation, due to the Brownian motion of the particle. We present a simple yet powerful modified Coulter counter that uses programmable data acquisition hardware to switch the voltage after sensing the resistive pulse of a nanoparticle passing through the orifice of a nanopipet. Switching the voltage reverses the direction of the driving force on the particle and, when this detect-switch cycle is repeated, allows us to pass an individual nanoparticle through the orifice thousands of times. By measuring individual particles more than 100 times per second we rapidly determine the distribution of the resistive pulses for each particle, which allows us to accurately determine the mean pulse amplitude and deliver considerably improved size resolution over a conventional Coulter counter. We show that single polystyrene nanoparticles can be shuttled back and forth and monitored for minutes, leading to a precisely determined mean blocking current equating to sub-angstrom size resolution. PMID:26549738

  2. First Townsend coefficient of organic vapour in avalanche counters

    International Nuclear Information System (INIS)

    A new concept is presented in the paper for implementing the proven method of determining the first Townsend coefficient (α) of gases using an avalanche counter. The A and B gas constants, interrelated by the expression α/p=A exp[-B/(K/p)], are analyzed. Parallel-plate avalanche counters (PPAC) with an electrode spacing d from 0.1 to 0.4 cm have been employed for the investigation, arranged to register low-energy alpha particles at n-heptane vapour pressures of p≥5 Torr. An in-depth discussion is given, covering the veracity and the behaviour vs K/p, of the n-heptane A and B constants determined at reduced electric-field intensity values ranging from 173.5 to 940 V/cm Torr; the constants have been found to depend upon d. The results of the investigation are compared to available data of the α coefficient of organic vapours used in avalanche counters. The PPAC method of determining α reveals some imperfections at very low values of the pd product. (orig.)

  3. Digital electronics for the Pierre Auger Observatory AMIGA muon counters

    Science.gov (United States)

    Wainberg, O.; Almela, A.; Platino, M.; Sanchez, F.; Suarez, F.; Lucero, A.; Videla, M.; Wundheiler, B.; Melo, D.; Hampel, M. R.; Etchegoyen, A.

    2014-04-01

    The ``Auger Muons and Infill for the Ground Array'' (AMIGA) project provides direct muon counting capacity to the Pierre Auger Observatory and extends its energy detection range down to 0.3 EeV. It currently consists of 61 detector pairs (a Cherenkov surface detector and a buried muon counter) distributed over a 23.5 km2 area on a 750 m triangular grid. Each counter relies on segmented scintillator modules storing a logical train of `0's and `1's on each scintillator segment at a given time slot. Muon counter data is sampled and stored at 320 MHz allowing both the detection of single photoelectrons and the implementation of an offline trigger designed to mitigate multi-pixel PMT crosstalk and dark rate undesired effects. Acquisition is carried out by the digital electronics built around a low power Cyclone III FPGA. This paper presents the digital electronics design, internal and external synchronization schemes, hardware tests, and first results from the Observatory.

  4. Digital Electronics for the Pierre Auger Observatory AMIGA Muon Counters

    CERN Document Server

    Wainberg, O; Platino, M; Sanchez, F; Suarez, F; Lucero, A; Videla, M; Wundheiler, B; Melo, D; Hampel, M; Etchegoyen, A

    2013-01-01

    The "Auger Muons and Infill for the Ground Array" (AMIGA) project provides direct muon counting capacity to the Pierre Auger Observatory and extends its energy detection range down to 0.3 EeV. It currently consists of 61 detector pairs (a Cherenkov surface detector and a buried muon counter) distributed over a 23.5 km2 area on a 750 m triangular grid. Each counter relies on segmented scintillator modules storing a logical train of '0's and '1's on each scintillator segment at a given time slot. Muon counter data is sampled and stored at 320 MHz allowing both the detection of single photoelectrons and the implementation of an offline trigger designed to mitigate multi-pixel PMT crosstalk and dark rate undesired effects. Acquisition is carried out by the digital electronics built around a low power Cyclone III FPGA. This paper presents the digital electronics design, internal and external synchronization schemes, hardware tests, and first results from the Observatory.

  5. Calibration and performance test results of uranium lung counter

    International Nuclear Information System (INIS)

    A uranium lung counter specially designed for assessment of internal contamination has recently been added to the Health Physics Department of Korea Atomic Energy Research Institute. The counting chamber is constructed of 10 cm low background steel plate for walls, floor and ceiling. The interior is covered with stainless steel liner. The internal dimensions of the counting chamber are 213 cm W x 86 cm D x 137 cm H. The detection system consists of four LEGe detection, and each detector equipped with 0.5 mm Be window has active area of 20 cm2 and thickness of 20 mm. The counter was calibrated by means of the LLNL phantom with lung source sets containing 241Am and 152Eu. Values of MDA based on a 30 minute count of non-contaminated person with 2.2 cm chest wall thickness at 95% confidence level were found to be 5 Bq for 185.7 keV from 235U, and 69 Bq for 63.3 keV form 234Th and 97 Bq for 92.8 keV from 234Th, respectively. In addition to calibration, test for evaluating the performance of the counter in terms of bias and precision was also performed with the LLNL phantom and lung source sets containing 235U and 234Th. The results were within the acceptable limits. (author). 6 refs., 2 figs., 4 tabs

  6. A multiwire proportional counter for the detection of plutonium-239 in vivo

    International Nuclear Information System (INIS)

    Work is in progress on developing counters to detect plutonium in the human lungs. The need for a low background counter for such work is discussed and the design and construction of a multiwire gas proportional counter described. The performance of the counter with different gas fillings is considered and results obtained on background, resolution, field of view and efficiency are given. Future work will consist of using the counter in conjunction with a realistic chest phantom. An estimate of the limit of detection is derived. (author)

  7. Position sensitive multiwire proportional counter for the crystal X-spectrometer of Tore Supra tokamak

    International Nuclear Information System (INIS)

    A position sensitive proportional counter, for use in the Tore Supra X-spectrometer, is developed. The physics of X-photons detection, in those counters, are reviewed. The detector's design and construction are presented. Its surface of detection is five times larger than that of the previous counter (40 cm2 times 8 cm2). The counter's spatial resolution is measured, in order to verify whether or not the spectrometer performance is modified. The dead time influence is studied and correction procedures are obtained. An optical transmission line, between the counter and the electronics of the data acquisition system, is considered for use in gamma radiation or fusion neutron environments

  8. Evaluation of a fast neutron coincidence counter for the measurements of uranium samples

    International Nuclear Information System (INIS)

    A fast neutron coincidence counter using BC454/BGO phoswich detectors has been evaluated for the purpose of rapid verification measurements of uranium items. This counter uses custom electronics to identify and count coincidence neutrons in the presence of background radiation. Measurements of uranium standards were performed to evaluate the counter. This counter is successful in measuring uranium items but has a low efficiency that results in minimal improvement over current technology. An optimized counter can be built with better performance capabilities, but it is recommended that newer technologies be used instead

  9. Performance review of the high efficiency neutron counter

    International Nuclear Information System (INIS)

    A performance review of several High Efficiency Neutron Counters (HENCs) has been conducted for the purposes of quantifying the ranges of the inherent operating parameters, and for the qualitative assessment of the application of these parameters for the measurement of various waste types. The HENC is a passive neutron counter intended for use with multiplicity counting techniques for the assay of 200 liter (55 gallon) drums containing plutonium contaminated waste. The counter utilizes 113 3He proportional tubes which are organized into multiple counting channels and are arranged in a 4p geometry about the assay cavity. An Add- A-Source (AAS) Matrix Correction assembly is incorporated into the counter as the basis for compensating the assay values for the perturbation of the drum contents. Prior to use in the field, several fundamental operating parameters for the HENC must be determined during characterization of the counter. These parameters are determined by the neutron response characteristics of the assay cavity and signal processing electronics, and are differentiated from more typical calibration parameters as they are determined without the need for actual or representative plutonium or mixed-oxide samples. Examples of operating parameters include HV plateau, die-away profile, pre-delay setting, dead time parameters, central empty drum efficiency, gate utilization factors and spatial response profiles. The performance review is based on five HENCs manufactured in the span of approximately ten years, all of which are currently operating in the field at various nuclear facilities. The review serves to identify the range of values used for each of the operating parameters, and the impact on performance, if any, as a function of that range. The resulting database can then serve both as a standard by which future systems can be type tested, and as a source of initial settings for the operating parameters with the evident benefit of time-savings in the

  10. Counter-ion distribution around flexible polyelectrolytes having different molecular architecture.

    Science.gov (United States)

    Chremos, Alexandros; Douglas, Jack F

    2016-03-01

    We explore the monovalent counter-ion distribution around flexible highly-charged polyelectrolytes with different molecular architectures (linear chains, stars, and unknotted and trefoil rings) using molecular dynamics simulations that include an explicit solvent that interacts with the polyelectrolyte. In particular, we find that the molecular topology influences the fraction of counter-ions transiently associating with the polyelectrolyte on a scale of the order of the chain segments, forming a "condensed" counter-ion interfacial layer. As with the hydrogen bonding of water to proteins and other polymers, the persistence time of these interfacial "bound" counter-ions is relatively short, O(1 ps), and we characterize the fluctuations in the number of the counter-ions populating the interfacial layer. We also find that the counter-ions are distributed in a non-uniform fashion on the polyelectrolyte backbone, forming dynamical clusters whose form and average size is sensitive to molecular architecture. In addition, we find that the residual bound counter-ions, not located in either the interfacial layer or the bulk solution, form a diffuse ionic cloud around the polyelectrolyte due to the uncompensated polyelectrolyte charge along the backbone. Generally charge valence strongly influences the extent of the diffuse counter-ion cloud, but in the case of monovalent counter-ions, we find that the size of the diffuse counter-ion cloud nearly coincides with the polyelectrolyte radius of gyration, independent of molecular topology. PMID:26864861

  11. Swot analysis of using aerostats for surveillance in counter terrorism

    Science.gov (United States)

    ćetin, Hüseyin

    2013-06-01

    In today's conjuncture, the terrorist activities are the most compelling issue for the defence forces in maintaining homeland security. Especially, the terrorist elements that penetrate the homeland may give harm. This harm can be minimized by preventing the terrorist penetrations from homeland borders. In counter terrorism, having Intelligence, Surveillance and Reconnaissance (ISR) capability and using this capability by twenty four hours is deterrence for the terrorist groups. Aerostats emerge as the ideal platform which can provide this capability. Aerostats are unmanned and aerodynamically shaped balloons that are stayed in the air, fixed to the ground by steel cable(s). The aerostat is made of a large fabric envelope that is filled with nonflammable helium gas, which provides the lifting force. The cables also serve to supply the electrical power to the aerostat systems, and for data relay between the aerostat and the ground station. Aerostats are different from the other manned and Unmanned Aerial Vehicles (UAVs) because of aerostats' capabilities such as cost effectiveness, long endurance and high resolution image transmission. Especially having uninterrupted image transmission and surveillance capabilities is important to be advantageous in counter terrorism. In this article, a short definition of terrorism has been given and then the importance of ensuring the homeland border security has been emphasized in counter terrorism. In addition, the questions of "what are the technical capabilities, the usage areas and the purposes of aerostats?" will be introduced as a result of literature review. Finally the strengths and weaknesses of aerostats, opportunities and threats for the near future will be introduced by using "SWOT" analysis method.

  12. The Internal Gas Counter as a Precision Absolute Counting Device

    International Nuclear Information System (INIS)

    The internal gas counter is the most accurate device for the absolute counting of low energy radiations. Its usefulness can be extended to higher energies if the possible error effects are investigated and corrected thoroughly and the measuring conditions are properly chosen. The different sources of error in internal gas counting, e.g. field distortion by the isolators and guard tubes at the counter ends, irradiation from the ineffective end volumes into the counting volume, escape from the counting volume into the ends and walls, all kinds of sorption effects, and counting loss due to the finite energy discrimination during counting, are discussed in detail. The optimum counter design is derived from this discussion. The corrections for these error effects can be described with simple semi-empirical formulas, which depend only on a few constants which have to be determined. Measurements of T, 14C, 35S, 37A and 85Kr at counting-gas pressures of 200-750 Torr have been performed. They make it possible to determine all corrections in internal gas counting, depending on the energy and kind of the radiation and on the counting-gas pressure. This determination has.been done by using empirical extrapolation techniques as well as the derived formulas. The results make it possible to correct nearly every internal gas counting measurement of β-radiations, electrons and X-rays and to obtain final accuracies of 1%. Some examples of such measurements - the determination of the decay scheme of 85Kr, the measurement of the fluorescence yield of 37Cl and the half-life determination of 131mXe - are discussed briefly. (author)

  13. Low energy recoil detection with a spherical proportional counter

    OpenAIRE

    I. Savvidis; Katsioulas, I.; Eleftheriadis, C.; Giomataris, I.; Papaevangellou, T.

    2016-01-01

    We present low energy recoil detection results in the keV energy region, from measurements performed with the Spherical Proportional Counter (SPC). An ${}^{241}Am-{}^{9}{Be}$ fast neutron source is used in order to obtain neutron-nucleus elastic scattering events inside the gaseous volume of the detector. The detector performance in the $keV$ energy region was resolved by observing the $5.9\\ keV$ line of a ${}^{55}Fe$ X-ray source, with energy resolution of $9\\%$ ($\\sigma$). The toolkit GEANT...

  14. Countering the lingering threat of the Abu Sayyaf group

    OpenAIRE

    Cohn, Stephen C.

    2007-01-01

    This thesis will argue that the most effective strategy for eradicating the U.S. designated Foreign Terrorist Organization, the Abu Sayyaf Group (ASG), is to bolster the current peace talks between the Republic of the Philippines and the Moro Islamic Liberation Front (MILF). The MILF has been providing support and sanctuary to the ASG which has hindered U.S.-Philippine counter-terror operations. This thesis will explain why a shift in U.S.-Philippine strategy is required by examining what...

  15. Fabrication of solar cells with counter doping prevention

    Science.gov (United States)

    Dennis, Timothy D; Li, Bo; Cousins, Peter John

    2013-02-19

    A solar cell fabrication process includes printing of dopant sources over a polysilicon layer over backside of a solar cell substrate. The dopant sources are cured to diffuse dopants from the dopant sources into the polysilicon layer to form diffusion regions, and to crosslink the dopant sources to make them resistant to a subsequently performed texturing process. To prevent counter doping, dopants from one of the dopant sources are prevented from outgassing and diffusing into the other dopant source. For example, phosphorus from an N-type dopant source is prevented from diffusing to a P-type dopant source comprising boron.

  16. Empowering Kinship to Counter Control on Family Discourse in Indonesia

    Directory of Open Access Journals (Sweden)

    Ivanovich Agusta

    2009-12-01

    Full Text Available Indonesian government constructs a discourse on family duringmodernizing Indonesia. A conceptual “father” used to legitimate control of the regime, as well as “state ibuism” (“state mothering” to control especially women. A controlled family discourse is used around political sphere on national election, public administration, family planning, school, etc. State bureaucrats placed at national, provincial, regency, and village levels to control a nuclear family (Westernized type of family pushed for local people. Countering the dominant discourse, local family still integrates kinship based on women power. The actual and discourse of local kinship used for constructing local economy and local politics.

  17. Multiwire gas proportional counters. Decrepit antiques or classic performers?

    International Nuclear Information System (INIS)

    An overview of the operational characteristics of multiwire gas proportional counters is given with particular reference to their use in X-ray diffraction. Their strengths and weaknesses are analysed and it is demonstrated that these devices are able to offer a combination of features that is unique. Some examples of synchrotron radiation experiments performed with gas detectors are used to illustrate their performance, and finally, the current status of development and prospects for the future development of gas detectors are reviewed. (au) (34 refs.)

  18. Design of scintillation counter read-out by silicon photodiode

    International Nuclear Information System (INIS)

    Comparing Silicon Photodiode (SPD) with Photomultiplier (PMT), the former, even though no inner multiplication, still has been used to replace the latter for its small size, allowing compact arrangement, high quantum efficiency and no need of high voltage to be supplied. Besides, it is able to work in strong magnetic field. How to design a scintillation counter read-out by SPD including selection of SPD and optimization of working condition of SPD and how to match SPD with scintillators and how to design or select a preamplifier to read-out SPD's signals according to various experiments are presented

  19. Design of large counters for medium energy neutrons

    International Nuclear Information System (INIS)

    The design of efficient, large neutron detectors with excellent timing resolution is presented. Each detector consists of three contiguous scintillator blocks totalling 27x25x25 cm3 viewed by six 2 in. photomultiplier tubes. Design considerations are given, and the optimization calculations for the light pipe design are described. Eight counters have been constructed and calibrated. The detection efficiency η varies between 16% and 26% depending on the neutron energy and threshold setting. The time-of-flight resolution ranges from ≅1.2 ns (FWHM) to ≅1.0 ns (FWHM) for neutron energies from 80 to 290 MeV. (orig.)

  20. Counterparty Risk Externality: Centralized Versus Over-the-counter Markets

    OpenAIRE

    Acharya, Viral V; Alberto Bisin

    2011-01-01

    We model the opacity of over-the-counter (OTC) markets in a setup where agents share risks, but have incentives to default and their financial positions are not mutually observable. We show that this setup results in excess "leverage" in that parties take on short OTC positions that lead to levels of default risk that are higher than Pareto-efficient ones. In particular, OTC markets feature a "counterparty risk externality" that we show can lead to ex-ante productive inefficiency. This extern...

  1. Seeded QED cascades in counter propagating laser pulses

    CERN Document Server

    Grismayer, Thomas; Martins, Joana L; Fonseca, Ricardo; Silva, Luís O

    2015-01-01

    The growth rates of seeded QED cascades in counter propagating lasers are calculated with 2D/3D QED-PIC simulations. The dependence of the growth rate on laser polarisation and intensity are compared with analytical models that support simulations results. The models provide an insight regarding the qualitative trend of the cascade growth when the intensity of the laser field is varied. The results suggest that relativistic pair plasmas and efficient conversion from laser photons to gamma rays can be created with the typical intensities planned to operate on future ultra-intense laser facilities such as ELI or VULCAN.

  2. A 60 pc counter-rotating core in NGC 4621

    OpenAIRE

    Wernli, Fabien; Emsellem, Eric; Copin, Yannick

    2002-01-01

    We present adaptive optics assisted OASIS integral field spectrography of the S0 galaxy NGC 4621. Two-dimensional stellar kinematical maps (mean velocity and dispersion) reveal the presence of a 60 pc diameter counter-rotating core (CRC), the smallest observed to date. The OASIS data also suggests that the kinematic center of the CRC is slightly offset from the center of the outer isophotes. This seems to be confirmed by archival HST/STIS data. We also present the HST/WFPC2 V-I colour map, wh...

  3. High-level neutron coincidence counter maintenance manual

    Energy Technology Data Exchange (ETDEWEB)

    Swansen, J.; Collinsworth, P.

    1983-05-01

    High-level neutron coincidence counter operational (field) calibration and usage is well known. This manual makes explicit basic (shop) check-out, calibration, and testing of new units and is a guide for repair of failed in-service units. Operational criteria for the major electronic functions are detailed, as are adjustments and calibration procedures, and recurrent mechanical/electromechanical problems are addressed. Some system tests are included for quality assurance. Data on nonstandard large-scale integrated (circuit) components and a schematic set are also included.

  4. Social Appropriateness in EU Counter-Terrorism Law and Policy

    DEFF Research Database (Denmark)

    Martins, Bruno Oliveira

    versus justice equation, on the issues of privacy and data protection, and on the broader respect for fundamental rights more generally. In this process, the legitimacy and the social appropriateness of some of these measures have been questioned, both at the societal level and before or by European...... institutionalist theory with insights from the New Haven school, namely its societal and process-oriented conceptions of law, it crosses legal and political science traditions to explore the ways in which EU counter-terrorism law and policy acquire and maintain social appropriateness....

  5. Tracking with scintillating fibers and visible light photon counters

    International Nuclear Information System (INIS)

    A fiber tracking system was constructed at UCLA consisting of four layers of scintillating fiber ribbons coupled to visible light photon counters (VLPCs), and was tested by measuring cosmic ray tracks. The total length of the fiber array is 7 m: 4 m of scintillating fiber and 3 m of clear optical fiber, 083 mm diameter. An average number of 6 photoelectrons were detected by the VLPCs, 7 m from the cosmic ray interaction piont at the end of the fibers. The details of the experimental arrangement and the test results are presented. (orig.)

  6. Delayed Flash from Counter Jet of Gamma Ray Burst

    CERN Document Server

    Yamazaki, R; Nakamura, T; Yamazaki, Ryo; Ioka, Kunihito; Nakamura, Takashi

    2003-01-01

    If the X-ray flash is the gamma ray burst (GRB) observed with the large viewing angle from the forward jet, we show that the emission from the counter jet should be observed as the delayed flash in the UV or optical band several hours to a day after the X-ray flash. If the distance is several tens of Mpc or so, i.e., similar to GRB980425, FUV-MAMA on HST/STIS or UVOT on Swift can observe the delayed flash, so that the collimated jets of the GRBs may be directly confirmed.

  7. High speed pulse digitization in driftless gas scintillation proportional counters

    International Nuclear Information System (INIS)

    In a driftless gas scintillation proportional counter the observed light burst profile provides a wealth of information both about the incident photon and the transit of the electron cloud through the scintillation region. The different features of such profiles are difficult to separate with conventional analog electronics. In this work the authors apply the technique of high speed pulse digitization to the problem. They show that by this technique not only can the performance of the instrument be improved (e.g. background rejection) but valuable data can be obtained regarding the design of both the gas cell and the analysis electronics

  8. Filamentation instability of counter-streaming laser-driven plasmas

    CERN Document Server

    Fox, W; Bhattacharjee, A; Chang, P -Y; Germaschewski, K; Hu, S X; Nilson, P M

    2013-01-01

    Filamentation due to the growth of a Weibel-type instability was observed in the interaction of a pair of counter-streaming, ablatively-driven plasma flows, in a supersonic, collisionless regime relevant to astrophysical collisionless shocks. The flows were created by irradiating a pair of opposing plastic (CH) foils with 1.8 kJ, 2-ns laser pulses on the OMEGA EP laser system. Ultrafast laser-driven proton radiography was used to image the Weibel-generated electromagnetic fields. The experimental observations are in good agreement with the analytical theory of the Weibel instability and with particle-in-cell simulations.

  9. Alpha-particle emission from contaminants in counter materials

    International Nuclear Information System (INIS)

    Energy spectra of surface activities from thorium and uranium contaminants have been investigated for typical counter materials. Soft-tempered stainless steel with a rate of 1.2±0.1 α-particles emitted per 100 cm2 in one hour was found better than other stainless steel and far better than brass and aluminum. Energy spectra provide information about the contaminating activity and about its depth profile. Thorium, uranium and 210Pb contamination was also observed for thin sources of other materials including isotopically enriched materials. (orig.)

  10. Study on counter current extraction process of high enriched uranium

    International Nuclear Information System (INIS)

    The counter current extraction process of high enriched uranium with critically safe mixer-settler has been studied. The distribution curves of acidity and uranium in stages have been obtained. The results fitted well with test tube extraction cascade experiments. The interface height and the ratio of the contact phases have been determined. The height of liquid surface was lower than the critically safe limit during the operation. The recovery of uranium is greater than 99.9%, and the extraction efficiency of stage in 1 A mixer-settler is better than 85%

  11. Over-the-counter suboptimal dispensing of antibiotics in Uganda

    Directory of Open Access Journals (Sweden)

    Mukonzo JK

    2013-08-01

    Full Text Available Jackson K Mukonzo,1,2 Proscovia M Namuwenge,1 Gildo Okure,3 Benjamin Mwesige,1 Olivia K Namusisi,4 David Mukanga4 1Center for Operational Research Africa, Kampala, Uganda; 2Department of Pharmacology and Therapeutics, 3School of Public Health, Makerere University, Kampala, Uganda; 4African Field Epidemiologist Network, Kampala, Uganda Background: Overuse and misuse of antibiotics is a serious global problem. While resistance to older antibiotics is increasing, development of newer molecules has stalled. Resistance to the existing antibiotics that is largely driven by their high-volume use is a global public health problem. Uganda is one of the countries where prescription-only drugs, including antibiotics, can be obtained over the counter. We determined the rate of antibiotic dispensing and use in Uganda. Methods: The study utilized a descriptive cross-sectional study design to determine the number of antibiotic "prescribed" daily doses per 1,000 clients. Data were collected from one health center II, eight general/district hospitals, one national referral hospital, and 62 registered community pharmacies. From each study site, data were collected for five consecutive days over the months of November 2011 to January 2012. Results: The overall antibiotic issue rate was 43.2%. Amoxicillin, metronidazole, ciprofloxacin, sulfamethoxazole–trimethoprim, cloxacillin, and ampicillin, belonging to the WHO anatomical therapeutic chemical classifications of penicillin with extended spectra, imidazole derivatives, fluoroquinolones, and sulfonamide–trimethoprim combinations, constituted 70% of the issued antibiotics. About 41% of antibiotics were issued over the counter. At community pharmacies, where 30% of antibiotic dispensing occurred, the number of prescribed daily doses/1,000 antibiotic clients was 4,169 compared to 6,220, 7,350 and 7,500 at general/district hospitals, the national referral hospital, and the health center, respectively. Conclusion

  12. A culturally responsive counter-narrative of effective teaching

    Science.gov (United States)

    Gist, Conra D.

    2014-12-01

    How do you recognize an effective teacher's sociocultural consciousness? Tamara Wallace's and Brenda Brand's argument that sociocultural consciousness is the "brain" of effective culturally responsive instruction for students of color comes at a time when the system of teacher evaluation is being overhauled nationwide. Teacher observation tools are being piloted to develop a common language of effective instruction but often there is little attention given to sociocultural consciousness in these frameworks. This article develops a culturally responsive counter-narrative to explore the complexity of a teacher's racial consciousness during a teaching episode.

  13. Real-time reconfigurable counter-propagating beam-traps

    DEFF Research Database (Denmark)

    Tauro, Sandeep; Bañas, Andrew Rafael; Palima, Darwin;

    2010-01-01

    We present a versatile technique that enhances the axial stability and range in counter-propagating (CP) beam-geometry optical traps. It is based on computer vision to track objects in unison with software implementation of feedback to stabilize particles. In this paper, we experimentally...... demonstrate the application of this technique by real-time rapid repositioning coupled with a strongly enhanced axial trapping for a plurality of particles of varying sizes. Also exhibited is an interesting feature of this approach in its ability to automatically adapt and trap objects of varying dimensions...

  14. Electro-hydrodynamic propulsion of counter-rotating Pickering drops

    Science.gov (United States)

    Dommersnes, P.; Mikkelsen, A.; Fossum, J. O.

    2016-07-01

    Insulating particles or drops suspended in carrier liquids may start to rotate with a constant frequency when subjected to a uniform DC electric field. This is known as the Quincke rotation electro-hydrodynamic instability. A single isolated rotating particle exhibit no translational motion at low Reynolds number, however interacting rotating particles may move relative to one another. Here we present a simple system consisting of two interacting and deformable Quincke rotating particle covered drops, i.e. deformable Pickering drops. The drops attract one another and spontaneously form a counter-rotating pair that exhibits electro-hydrodynamic driven propulsion at low Reynolds number flow.

  15. Multiplication factors in ethylene-filled proportional counters.

    Science.gov (United States)

    Loyola, H; Birstein, L; Hevia, A

    2008-01-01

    Gas multiplication factors were measured in a proportional counter filled with high-purity ethylene in the pressure range 10-40 Torr. The multiplication factors were measured as a function of the reduced electric field S(a). The results show that, within the range of the high values of reduced electric field applied in this work (2648 Townsend coefficient alpha/P for ethylene may still be considered a function of S(a) alone. Good agreement was found with a model proposed by Akande. PMID:18682404

  16. High-level neutron coincidence counter maintenance manual

    International Nuclear Information System (INIS)

    High-level neutron coincidence counter operational (field) calibration and usage is well known. This manual makes explicit basic (shop) check-out, calibration, and testing of new units and is a guide for repair of failed in-service units. Operational criteria for the major electronic functions are detailed, as are adjustments and calibration procedures, and recurrent mechanical/electromechanical problems are addressed. Some system tests are included for quality assurance. Data on nonstandard large-scale integrated (circuit) components and a schematic set are also included

  17. Variable dead time counters: 2. A computer simulation

    International Nuclear Information System (INIS)

    A computer model has been developed to give a pulse train which simulates that generated by a variable dead time counter (VDC) used in safeguards determination of Pu mass. The model is applied to two algorithms generally used for VDC analysis. It is used to determine their limitations at high counting rates and to investigate the effects of random neutrons from (α,n) reactions. Both algorithms are found to be deficient for use with masses of 240Pu greater than 100g and one commonly used algorithm is shown, by use of the model and also by theory, to yield a result which is dependent on the random neutron intensity. (author)

  18. A silica aerogel counter for large-acceptance hadron detection

    International Nuclear Information System (INIS)

    In order to study the feasibility of large scale multicell counters, two prototypes with respective detection area 80x40 cm2 and 65x31 cm2 were constructed. The Cerenkov light produced in silica aerogel of refractive index n=1.03 and diffused in a well optimized box was detected with five quantacon photomultpliers. Results of beam tests concerning the aerogel thickness, the diffusing material and box shape, the influence of the incident particle position and the momentum threshold curves for π, K and p are presented. The final design of a multicell detection system is given. (Auth.)

  19. A silica aerogel counter for large-acceptance hadron detection

    CERN Document Server

    Arnault, C; Bassompierre, Gabriel; Burkhardt, W; Coignet, G; Dosselli, U; Heusse, P; Montanet, François; Schneegans, M

    1980-01-01

    In order to study the feasibility of large scale multicell counters, two prototypes with respective detection area 80*40 cm/sup 2/ and 65*31 cm/sup 2/ were constructed. The Cerenkov light produced in silica aerogel of refractive index n=1.03 and diffused in a well optimized box was detected with five quantacon photomultipliers. Results of beam tests concerning the aerogel thickness, the diffusing material and box shape, the influence of the incident particle position and the momentum threshold curves for pi , K and p are presented. The final design of a multicell detection system is given. (6 refs).

  20. External guard counters for low-level counting systems

    International Nuclear Information System (INIS)

    The high background reduction that has been obtained with a low-level Ge-crystal counting system with external, rather than internal, guard counters is analyzed. It is shown that this arrangement eliminates not only the muon component of the cosmic rays, but also a large part of the secondary gamma radiation it produces in the passive shield and therefore gives a much higher background reduction than the conventional arrangement with the guard system inside the main passive shield. The implication of this result for low-level counting is discussed with special reference to gas proportional counting systems used for radiocarbon dating. (orig.)

  1. A two-dimensional transmission counter with a backgammon-drift read-out technique

    International Nuclear Information System (INIS)

    A new type of two-dimensional position sensitive gas counter for transmission counter with a backgammon-shaped flat electrode has been developed. The two dimensional position read-out can be achieved with the combination of the backgammon-shaped flat electrode read-out as horizontal position and the drift time measurement read-out as vertical position. The gas counter is designed as a transmission trajectory counter that can be used to determined angle of incident charged particle in the charged particle detecting system. To check the characteristics of this gas counter, test experiments are performed with a coincidence plastic scintillation counter and β-ray source of 90Sr. (author)

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

    DEFF Research Database (Denmark)

    Lindekilde, Lasse

    2012-01-01

    assessing the impact of counter-radicalisation measures using Denmark as case study. It shows how the model of radicalisation underlying the Danish counter-radicalisation efforts translate into multilayered policy objectives and diversified policy solutions, and how the initial academic and official...... 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...... assessments of the impact of Danish counter-radicalisation policies on end target groups following is impaired and weakened by common methodological problems and challenges. The article concludes by suggesting some ways ahead for more systematic and valid assessments of the impact of counter...

  3. Real-time garbage collection for list processing using restructured cells for increased reference counter size

    Science.gov (United States)

    Shuler, Jr., Robert L. (Inventor)

    1990-01-01

    In a list processing system, small reference counters are maintained in conjunction with memory cells for the purpose of identifying memory cells that become available for re-use. The counters are updated as references to the cells are created and destroyed, and when a counter of a cell is decremented to logical zero the cell is immediately returned to a list of free cells. In those cases where a counter must be incremented beyond the maximum value that can be represented in a small counter, the cell is restructured so that the additional reference count can be represented. The restructuring involves allocating an additional cell, distributing counter, tag, and pointer information among the two cells, and linking both cells appropriately into the existing list structure.

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

    International Nuclear Information System (INIS)

    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.)

  5. Partial heating between counter propagating quantum Hall edge channels

    Science.gov (United States)

    Washio, Kazuhisa; Nakazawa, Ryo; Hashisaka, Masayuki; Muraki, Koji; Fujisawa, Toshimasa

    2014-03-01

    In contrast to clear unidirectional charge flow in quantum Hall edge channels, heat transport and equilibration remain veiled. Most of the previous works were concentrated on heating between co-propagating edge channels, where co-propagating charge and spin modes are formed by the Coulomb interaction. Here, we investigate heating between counter propagating edge channels separated by a narrow surface gate of the width 0.1 μm, where the plasmon coupling forms counter-propagating dragging modes. One edge channel is directly heated up by a quantum point contact at its half transmission, and energy spectrum of the other edge channel is evaluated by quantum dot thermometry. We observed partial heating in the spectrum, where a small fraction (1-5 percent) of electrons is highly excited over the original Fermi distribution, for an interaction length of 5-10 μm in the coupled channels. This can be understood by considering weak scattering process between the channels. The flow of this non-equilibrium distribution will be discussed with different configurations of heating and detecting channels in terms of the chirality and the dragging modes. JSPS KAKENHI Grant Numbers 21000004, 24009291.

  6. Applicability of condensation particle counters to measure atmospheric clusters

    Directory of Open Access Journals (Sweden)

    M. Sipilä

    2008-03-01

    Full Text Available The ambient and laboratory molecular and ion clusters were investigated. Here we present data on the ambient concentrations of both charged and uncharged molecular clusters as well as the performance of a pulse height condensation particle counter (PH-CPC and an expansion condensation particle counter (E-CPC. The ambient molecular cluster concentrations were measured using both instruments, and they were deployed in conjunction with ion spectrometers and other aerosol instruments in Hyytiälä, Finland at the SMEAR II station during 1 March to 30 June 2007. The observed cluster concentrations varied and were from ca. 1000 to 100 000 cm−3. Both instruments showed similar concentrations. The average size of detected clusters was approximately 1.8 nm. As the atmospheric measurements at sub 2-nm particles and molecular clusters are a challenging task, and we were most likely unable to detect the smallest clusters, the reported concentrations are our best estimates for minimum cluster concentrations in boreal forest environment.

  7. Study of rare earth separation by counter current electromigration

    International Nuclear Information System (INIS)

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

  8. Comparison WSP vs. PNA - application to FASTSCAN whole body counter

    International Nuclear Information System (INIS)

    The FASTSCAN whole body counter is designed to quickly and accurately monitor people for internal contamination of radionuclides with energies between 300 keV to 1.8 MeV. The FASTSCAN system uses large area sodium iodide detectors and Canberra's ABACOS and Genie Software to achieve low minimum detectable activities with count times as fast as one minute. Canberra's FASTSCAN System includes two large sodium iodide detectors (Nal(Tl)) 7.6 x 12.7 x 40.6 cm that typically provide a priori Lower Limit of Detection of approximately 150 Bq (4 nCi) for Co-60 with a count time of one minute for a normal person containing K-40. Two different analytical tools for gamma analysis have been compared: a ) traditional method based on analysis of only full absorption peak (PNA), and b ) vector method based on whole spectrum processing (WSP). The PNA calculations have been performed using Canberra's Genie 2000 Software. On the other hand, own BOB Spectra Discovery System has been used for the WSP calculations of incident spectra. The calibration of the both systems has been made employing the Canberra Transfer Phantom for in vivo whole body counter. A comparison study of the both method has been performed according to uniform Curie' s concept of minimum detectable activity. (author)

  9. Comparison WSP vs. PNA - application to FASTSCAN whole body counter

    International Nuclear Information System (INIS)

    The FASTSCAN whole body counter is designed to quickly and accurately monitor people for internal contamination of radionuclides with energies between 300 keV to 1.8 MeV. The FASTSCAN system uses large area sodium iodide detectors and Canberra's ABACOS and Genie Software to achieve low minimum detectable activities with count times as fast as one minute. Canberra's FASTSCAN System includes two large sodium iodide detectors (Nal(Tl)) 7.6 x 12.7 x 40.6 cm that typically provide a priori Lower Limit of Detection of approximately 150 Bq (4 nCi) for Co-60 with a count time of one minute for a normal person containing K-40. Two different analytical tools for gamma analysis have been compared: a ) traditional method based on analysis of only full absorption peak (PNA), and b ) vector method based on whole spectrum processing (WSP). The PNA calculations have been performed using Canberra's Genie 2000 Software. On the other hand, own BOB Spectra Discovery System has been used for the WSP calculations of incident spectra. The calibration of the both systems has been made employing the Canberra Transfer Phantom for in vivo whole body counter. A comparison study of the both method has been performed according to uniform Curie' s concept of minimum detectable activity. (authors)

  10. MONITORING THE SAFETY ASPECTS OF OVER THE COUNTER MEDICATIONS

    Directory of Open Access Journals (Sweden)

    M.Z. Subin

    2012-03-01

    Full Text Available OTC medication is short for over the counter drugs. These medicines have become popular as they are available without a prescription from the doctor. These are medicaments that are usually used to relieve pain and to treat various symptoms of cold. Most of the over-the-counter users believe that these medications are safer and are devoid of unwanted side effects. But their use may become fatal sometimes when they are administered without knowing the prescription pattern, that is, when they are used without properly reading the directions on the label. More over, the consumers are not aware of the safety of these drugs and its frequent use may result in various adverse effects. It is the part of the patient to read out the label packaging instructions for OTC medications to know how much one should take, the possible side effects that may encounter and the various conditions that can result in poor choice of the drug. Various other aspects such as the recommended dose, contraindications and drug interactions should be considered before taking OTC drugs. Pharmacists and drug companies will have an increasingly important role in giving information and advice to the patients. This review highlights the safety aspects of OTC drugs. It summarizes the safety measures that should be taken into consideration when used among different age groups.

  11. Whole body counter intercomparison as a tool of quality assurance

    International Nuclear Information System (INIS)

    In several countries guidelines exist concerning the requirements of whole-body counter measurements where the performance criteria for the quantities of bias, precision and minimum detectable amount are specified. One or more of these quantities are mostly the subject of intercomparison programmes. The whole-body counter laboratory of the KFKI Atomic Energy Research Institute has paid great attention to the good quality of measurements carried out for the determination of radionuclides incorporated in the human body. Participation in intercomparison programmes proved to be a very important and useful tool to check the capability and reliability of methods used. This laboratory participated in nine international intercomparison exercises organised in recent years, by means of which the counting efficiency has been tested for different detectors, monitoring geometries, body shapes and sizes, calibration and evaluation methods used. It can be concluded that in the majority of cases the results obtained were well within the range of performance criteria generally accepted in whole-body counting. (author)

  12. A 60 pc counter-rotating core in NGC 4621

    CERN Document Server

    Wernli, F; Copin, Y; Wernli, Fabien; Emsellem, Eric; Copin, Yannick

    2002-01-01

    We present adaptive optics assisted OASIS integral field spectrography of the S0 galaxy NGC 4621. Two-dimensional stellar kinematical maps (mean velocity and dispersion) reveal the presence of a 60 pc diameter counter-rotating core (CRC), the smallest observed to date. The OASIS data also suggests that the kinematic center of the CRC is slightly offset from the center of the outer isophotes. This seems to be confirmed by archival HST/STIS data. We also present the HST/WFPC2 V-I colour map, which exhibits a central elongated red structure, also slightly off-centered in the same direction as the kinematic centre. We then construct an axisymmetric model of NGC 4621: the two-integral distribution function is derived using the Multi-Gaussian Expansion and the Hunter & Qian (1993) formalisms. Although the stellar velocities are reasonably fitted, including the region of the counter-rotating core, significant discrepancies between the model and the observations demonstrate the need for a more general model (e.g....

  13. High speed non-latching squid binary ripple counter

    International Nuclear Information System (INIS)

    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/Nb2O5/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

  14. Counter rotating type hydroelectric unit suitable for tidal power station

    Energy Technology Data Exchange (ETDEWEB)

    Kanemoto, T [Faculty of Engineering, Kyushu Institute of Technology, Sensui 1-1, Tobata, Kitakyushu 804-8550 (Japan); Suzuki, T, E-mail: turbo@tobata.isc.kyutech.ac.j [Graduate School of Engineering, Kyushu Institute of Technology, Sensui 1-1, Tobata, Kitakyushu 804-8550 (Japan)

    2010-08-15

    The counter rotating type hydroelectric unit, which is composed of the axial flow type tandem runners and the peculiar generator with double rotational armatures,was proposed to utilize effectively the tidal power. In the unit, the front and the rear runners counter drive the inner and the outer armatures of the generator, respectively. Besides, the flow direction at the rear runner outlet must coincide with the flow direction at the front runner inlet, because the angular momentum through the rear runner must coincides with that through the front runner. That is, the flow runs in the axial direction at the rear runner outlet while the axial inflow at the front runner inlet. Such operations are suitable for working at the seashore with rising and falling tidal flows, and the unit may be able to take place of the traditional bulb type turbines. The tandem runners were operated at the on-cam conditions, in keeping the induced frequency constant. The output and the hydraulic efficiency are affected by the adjustment of the front and the blade setting angles. The both optimum angles giving the maximum output and/or efficiency were presented at the various discharges/heads. To promote more the tidal power generation by this type unit, the runners were also modified so as to be suitable for both rising and falling flows. The hydraulic performances are acceptable while the output is determined mainly by the trailing edge profiles of the runner blades.

  15. Counter rotating type hydroelectric unit suitable for tidal power station

    Science.gov (United States)

    Kanemoto, T.; Suzuki, T.

    2010-08-01

    The counter rotating type hydroelectric unit, which is composed of the axial flow type tandem runners and the peculiar generator with double rotational armatures,was proposed to utilize effectively the tidal power. In the unit, the front and the rear runners counter drive the inner and the outer armatures of the generator, respectively. Besides, the flow direction at the rear runner outlet must coincide with the flow direction at the front runner inlet, because the angular momentum through the rear runner must coincides with that through the front runner. That is, the flow runs in the axial direction at the rear runner outlet while the axial inflow at the front runner inlet. Such operations are suitable for working at the seashore with rising and falling tidal flows, and the unit may be able to take place of the traditional bulb type turbines. The tandem runners were operated at the on-cam conditions, in keeping the induced frequency constant. The output and the hydraulic efficiency are affected by the adjustment of the front and the blade setting angles. The both optimum angles giving the maximum output and/or efficiency were presented at the various discharges/heads. To promote more the tidal power generation by this type unit, the runners were also modified so as to be suitable for both rising and falling flows. The hydraulic performances are acceptable while the output is determined mainly by the trailing edge profiles of the runner blades.

  16. Monolithic Active Pixel Matrix with Binary Counters (MAMBO) ASIC

    Energy Technology Data Exchange (ETDEWEB)

    Khalid, Farah F.; Deptuch, Grzegorz; Shenai, Alpana; Yarema, Raymond J.; /Fermilab

    2010-11-01

    Monolithic Active Matrix with Binary Counters (MAMBO) is a counting ASIC designed for detecting and measuring low energy X-rays from 6-12 keV. Each pixel contains analogue functionality implemented with a charge preamplifier, CR-RC{sup 2} shaper and a baseline restorer. It also contains a window comparator which can be trimmed by 4 bit DACs to remove systematic offsets. The hits are registered by a 12 bit ripple counter which is reconfigured as a shift register to serially output the data from the entire ASIC. Each pixel can be tested individually. Two diverse approaches have been used to prevent coupling between the detector and electronics in MAMBO III and MAMBO IV. MAMBO III is a 3D ASIC, the bottom ASIC consists of diodes which are connected to the top ASIC using {mu}-bump bonds. The detector is decoupled from the electronics by physically separating them on two tiers and using several metal layers as a shield. MAMBO IV is a monolithic structure which uses a nested well approach to isolate the detector from the electronics. The ASICs are being fabricated using the SOI 0.2 {micro}m OKI process, MAMBO III is 3D bonded at T-Micro and MAMBO IV nested well structure was developed in collaboration between OKI and Fermilab.

  17. Low-background high-efficiency Geiger-Mueller counter

    International Nuclear Information System (INIS)

    The problem of measuring solid radioactive samples of low-activity with semi-portable equipment is one that is common to many branches of applied science; laboratories working in the fields of radiochemistry, agriculture, biology and oceanography are among the principal operators of, such measuring sets. This report describes a low-background, high-efficiency Geiger-Muller flow-counter which was developed by E. A. Keroe, H. C. Figdor and J. Koeck in the period 1959-61 and which has been since then in constant use at the International Atomic Energy Agency laboratory at Seibersdorf. The instrument described will measure samples, with activities of fractions of picocuries to tens of picocuries, dispersed in 30 mg of carrier substance. The high-efficiency and low-background are achieved by careful design of the G-M counter and the effective suppression of penetrating radiation by using the anticoincidence umbrella principle. The G-M umbrella tube used is small and thus it was possible to keep the weight of the measuring unit, including all iron shielding, down to only 700 kg. By publishing this report, the Agency hopes that the information given will prove useful to all those who are interested in making routine analyses on solid samples whose low activities have, in the past, rendered such assays difficult and tedious

  18. Infant breathing rate counter based on variable resistor for pneumonia

    Science.gov (United States)

    Sakti, Novi Angga; Hardiyanto, Ardy Dwi; La Febry Andira R., C.; Camelya, Kesa; Widiyanti, Prihartini

    2016-03-01

    Pneumonia is one of the leading causes of death in new born baby in Indonesia. According to WHO in 2002, breathing rate is very important index to be the symptom of pneumonia. In the Community Health Center, the nurses count with a stopwatch for exactly one minute. Miscalculation in Community Health Center occurs because of long time concentration and focus on two object at once. This calculation errors can cause the baby who should be admitted to the hospital only be attended at home. Therefore, an accurate breathing rate counter at Community Health Center level is necessary. In this work, resistance change of variable resistor is made to be breathing rate counter. Resistance change in voltage divider can produce voltage change. If the variable resistance moves periodically, the voltage will change periodically too. The voltage change counted by software in the microcontroller. For the every mm shift at the variable resistor produce average 0.96 voltage change. The software can count the number of wave generated by shifting resistor.

  19. The HERA-B ring imaging Cherenkov counter

    Science.gov (United States)

    Ariño, I.; Bastos, J.; Broemmelsiek, D.; Carvalho, J.; Chmeissani, M.; Conde, P.; Davila, J.; Dujmić, D.; Eckmann, R.; Garrido, L.; Gascon, D.; Hamacher, T.; Gorišek, A.; Ivaniouchenkov, I.; Ispirian, M.; Karabekian, S.; Kim, M.; Korpar, S.; Križan, P.; Kupper, S.; Lau, K.; Maas, P.; McGill, J.; Miquel, R.; Murthy, N.; Peralta, D.; Pestotnik, R.; Pyrlik, J.; Ramachandran, S.; Reeves, K.; Rosen, J.; Schmidt-Parzefall, W.; Schwarz, A.; Schwitters, R. F.; Siero, X.; Starič, M.; Stanovnik, A.; Škrk, D.; Živko, T.

    2004-01-01

    The HERA-B RICH uses a radiation path length of 2.8 m in C 4F 10 gas and a large 24 m2 spherical mirror for imaging Cherenkov rings. The photon detector consists of 2240 Hamamatsu multi-anode photomultipliers with about 27 000 channels. A 2:1 reducing two-lens telescope in front of each photomultiplier tube increases the sensitive area at the expense of increased pixel size, resulting in a contribution to the resolution which roughly matches that of dispersion. The counter was completed in January of 1999, and its performance has been steady and reliable over the years it has been in operation. The design performance of the Ring Imaging Cherenkov counter was fully reached: the average number of detected photons in the RICH for a β=1 particle was found to be 33 with a single-hit resolution of 0.7 and 1 mrad in the fine and coarse granularity regions, respectively.

  20. Absolute measurements with a 4 π-counter

    International Nuclear Information System (INIS)

    Measurements on standardized p-emitters have been made in a 4 it proportional flow-counter. The counter efficiency is found to be near 100 %. Absorption curves have been determined with plastic foils and aluminium. A comparison is made between the self-absorption arising in different methods of source preparation which include precipitates and the use of wetting agents The most reliable results have been obtained with sources on aluminium foils, where the foil absorption is calculated from the absorption curves and the self-absorption is supposed to be negligible for isotopes with end point energy above 0.5 MeV. The β-emitters studied have energies ranging from 1.71 MeV (32P) to 0.167 MeV (35S). Most of them have been obtained from National Physical Laboratory and Atomic Energy Research Establishment, Harwell, England. The agreement between their calibration and our measurements is very good except in the case of Co 60

  1. Molecular strategies of plant defense and insect counter-defense

    Institute of Scientific and Technical Information of China (English)

    KEYANZHU-SALZMAN; JIAN-LONGBI; TONG-XIANLIU

    2005-01-01

    The prediction of human population growth worldwide indicates there will be a need to substantially increase food production in order to meet the demand on food supply.This can be achieved in part by the effective management of insect pests. Since plants have co-evolved with herbivorous insects for millions of years, they have developed an array of defense genes to protect themselves against a wide variety of chewing and sucking insects.Using these naturally-occurring genes via genetic engineering represents an environmentally friendly insect pest-control measure. Insects, however, have been actively evolving adaptive mechanisms to evade natural plant defenses. Such evolved adaptability undoubtedly has helped insects during the last century to rapidly overcome a great many humanimposed management practices and agents, including chemical insecticides and genetically engineered plants. Thus, better understanding of the molecular and genetic basis of plant defense and insect counter-defense mechanisms is imperative, not only from a basic science perspective, but also for biotechnology-based pest control practice. In this review, we emphasize the recent advance and understanding of molecular strategies of attack-counterattack and defense-counter-defense between plants and their herbivores.

  2. Development of Ring Imaging Cherenkov counter with silica aerogel radiator

    International Nuclear Information System (INIS)

    In order to answer a simple and basic question on how spin 1/2 of proton can be understood from spin quark, one of its constructing elements, some deep inelastic scattering experiments using high energy polarized electron beam and polarized target have been carried out. At this time, if amounts of informations can also be increased by carrying out particle discrimination of hadron particle formed with the scattering, it can be practiced to investigate some contributions to proton spin at every flavor of the quark and of gluon present in proton. It is a Ring Imaging Cherenkov (RICH) counter capable of detecting a light (Cherenkov radiation) conically radiated when charged ;article moves at higher speed than that of light in a medium, to measure speed of the particle. Now, a RICH counter using two kinds of materials such as silica aerogel with middle refractive indices between solid/liquid and vapor (n = 1.03) and C4F10 gas (n = 1.0014) for a radiator was developed to make possible on discrimination of pion/kaon meson, proton and anti-proton at a momentum region of 2 to 20 GeV/c. Here were described on some characteristics of the RICH developed at HERMES experiment, and then on structure of the RICH and features of particle discrimination. (G.K.)

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

    International Nuclear Information System (INIS)

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

  4. Proceedings of the symposium on measurements of neutron energy spectra using recoil proton proportional counters

    International Nuclear Information System (INIS)

    This is a report of the symposium on measurements of neutron energy spectra using recoil proton proportional counters held at the Research Reactor Institute of Kyoto University on January 27 in 1986. An energy resolution, wall effects of response functions, n · γ discrimination methods and other fundamental properties of recoil proton counters are discussed for a new development of an application of this counter. (author)

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

    International Nuclear Information System (INIS)

    The effect of external γ radiation on the process of counting 71Ge 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

  6. Anthocyanin-sensitized solar cells using carbon nanotube films as counter electrodes

    Science.gov (United States)

    Zhu, Hongwei; Zeng, Haifeng; Subramanian, Venkatachalam; Masarapu, Charan; Hung, Kai-Hsuan; Wei, Bingqing

    2008-11-01

    Carbon nanotube (CNT) films have been used as counter electrodes in natural dye-sensitized (anthocyanin-sensitized) solar cells to improve the cell performance. Compared with conventional cells using natural dye electrolytes and platinum as the counter electrodes, cells with a single-walled nanotube (SWNT) film counter electrode show comparable conversion efficiency, which is attributed to the increase in short circuit current density due to the high conductivity of the SWNT film.

  7. Development of High Precision Timing Counter Based on Plastic Scintillator with SiPM Readout

    OpenAIRE

    Cattaneo, Paolo W.; De Gerone, Matteo; Gatti, Flavio; Nishimura, Miki; Ootani, Wataru; Rossella, Massimo; Uchiyama, Yusuke

    2014-01-01

    High-time-resolution counters based on plastic scintillator with silicon photomultiplier (SiPM) readout have been developed for applications to high energy physics experiments for which relatively large-sized counters are required. We have studied counter sizes up to $120\\times40\\times5$ mm^3 with series connection of multiple SiPMs to increase the sensitive area and thus achieve better time resolution. A readout scheme with analog shaping and digital waveform analysis is optimized to achieve...

  8. The emancipatory potential of online reporting: The case of counter accounting

    OpenAIRE

    Sonja Gallhofer; Jim Haslam; Elizabeth Monk; Clare Roberts

    2006-01-01

    Purpose – The purpose of this paper is to elaborate upon the notion of counter accounting, to assess the potentiality of online reports for counter accounting and hence for counter accounting's emancipatory potential as online reporting, to assess the extent to which this potential is being realised and to suggest ways forward from a critical perspective. Design/methodology/approach – There are several components to a critical interpretive analysis: critical evaluative analysis, informed to s...

  9. Microstructure and properties of vacuum counter-pressure cast aluminum alloy

    OpenAIRE

    YAN Qing-song; Yu, Huan; WEI Bo-kang

    2006-01-01

    The microstructure and properties of vacuum counter-pressure cast aluminum alloy were studied. Results indicated that under the condition of vacuum counter-pressure, liquid melts fill mould cavity under the vacuum and crystallize under high pressure which have very good effect on nucleation and solidification feeding. Compared with gravity casting, the microstructure of vacuum counter-pressure cast aluminum alloy is much finer and more uniformly distributed. Mechanical properties of vacuum co...

  10. Anthocyanin-sensitized solar cells using carbon nanotube films as counter electrodes

    International Nuclear Information System (INIS)

    Carbon nanotube (CNT) films have been used as counter electrodes in natural dye-sensitized (anthocyanin-sensitized) solar cells to improve the cell performance. Compared with conventional cells using natural dye electrolytes and platinum as the counter electrodes, cells with a single-walled nanotube (SWNT) film counter electrode show comparable conversion efficiency, which is attributed to the increase in short circuit current density due to the high conductivity of the SWNT film.

  11. Cryogenic resonance-electron Moessbauer spectroscopy with a helium-filled proportional counter

    International Nuclear Information System (INIS)

    As studied in our previous works,a proportional counter filled with pure helium gas works well at low temperatures near 4.2 K. The helium-filled proportional counter (HFPC) provides us with method to detect nuclear radiations at low temperatures. A typical application of this counter is resonance-electron Moessbauer spectroscopy (REMS) at low temperatures (<∼30 K). In this article some examples of REMS measurements with HFPC are given. (author)

  12. Tactical unmanned aerial vehicles in a proposed joint infrastructure to counter theater ballistic missiles

    OpenAIRE

    Junker, Vernon L.

    1995-01-01

    Proliferation of tactical ballistic missile (IBM) systems throughout the Third World represents a serious threat to American national interests. As demonstrated during operation Desert Storm in Iraq, countering this threat is a very difficult problem. A joint, multi-level infrastructure to counter the TBM threat is vital to American security. This thesis considers the joint infrastructure and tactics necessary to counter the TBM threat. During peacetime, infrastructure assets monitor TBM forc...

  13. Waste Management Practices among Counter Service Restaurants in Batangas City, Philippines

    Directory of Open Access Journals (Sweden)

    Billy T. Festijo

    2013-08-01

    Full Text Available The study looked into the extent of the proper waste management of the counter service restaurants in Batangas City, Philippines. The waste management of counter service restaurant highlighted on reducing the food establishment demand for virgin raw materials through increasing waste prevention and recycling. The problem encountered of the counter service restaurant agrees on the government policy that was implementing in our country. The proposed plan of action will help the counter service restaurant may serve as a guide in minimization of the waste management.

  14. Influence of Higher Valence Ions on Flexible Polyelectrolytes Stiffness and Counter-ion Distribution

    Science.gov (United States)

    Chremos, Alexandros; Douglas, Jack F.

    We investigate the influence of counter-ion valency on the flexibility of highly charged flexible polymer chains by molecular dynamics simulations that include both salt and an explicit solvent. A theoretical understanding of solutions of these molecules (e.g., DNA, RNA, and sulfonate polyestyrene) has been slow to develop due to the complex coupling between the polyelectrolyte conformation and the ionic species in solution due to their long range Coulomb interactions. As observed experimentally, we find that divalent counter-ions greatly reduce the chain persistence length, in comparison to monovalent counter-ions, an effect correlated with the tendency of the polyelectrolyte chain to become distorted by divalent counter-ions. We rationalize these results by with the substantial increase of counter-ion population at the interface with the polyelectrolyte, which not only leads to a more effective screening of the bare charge, but also leads to charge inversion in the trivalent counter-ion case. These conformational changes with counter-ion valency are also associated with a drastic increase of the number of contacts the counter-ions have at the interface with polyelectrolyte, an effect associated with polyelectrolyte chain ``coiling'' around the counter-ions. NIST Postdoctoral Fellowship.

  15. Improving performance of charge sensitive preamplifier in liquid scintillation counter using constant current technology

    International Nuclear Information System (INIS)

    There are various charge constant current technologies for liquid scintillation circuit. The constant current technology, charge technology and their application to liquid scintillation counter are emphasized

  16. Application of microporous polyaniline counter electrode for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qinghua; Wu, Jihuai; Tang, Qunwei; Lan, Zhang; Li, Pinjiang; Lin, Jianming; Fan, Leqing [Institute of Materials Physical Chemistry, Huaqiao University, Fengze Area, Quanzhou, Fujian 362021 (China)

    2008-09-15

    An inexpensive microporous polyaniline (PANI) is used as a substitute for platinum to construct the counter electrode in dye-sensitized solar cells (DSSCs). The PANI counter electrode with microporosity and a size diameter of about 100 nm possesses lower charge-transfer resistance and higher electrocatalytic activity for the I{sub 3}{sup -}/ I{sup -} redox reaction than Pt electrode does. The overall energy conversion efficiency of the DSSC with PANI counter electrode reaches 7.15%, which is higher than that of the DSSC with Pt counter electrode. The excellent photoelectric properties, simple preparation procedure and inexpensive cost allow PANI electrode to be a credible alternative for DSSCs. (author)

  17. An open multiple GM-counter for the measurement of low-energy beta samples

    International Nuclear Information System (INIS)

    For the measurement of low-energy beta activity, an open, multiple gas flow GM-counter has been developed. The counter is espesially developed for the measurement of low-energy 63Ni samples electrolyzed on thin steel sheets. Four samples may be simultaneously measured in four counting elements integrated into the same mechnanical unit. A common guard counter reduces the background noise by the use of anticoincidence techniques. Mounted into a 100 mm thick lead screen, the GM-counter operates in a background radiation of appr. 0.2 cpm. Preliminary measurements on electrolyzed 63Ni samples, show a counting efficiency of appr. 40%

  18. DESIGN OF MODULO-6-COUNTER USING CARBON NANOTUBE FIELD EFFECT TRANSISTOR

    Directory of Open Access Journals (Sweden)

    V.Saravanan

    2012-11-01

    Full Text Available In many digital applications like digital clock, frequency divider circuit and nano applications etc., designing of low power modulo counters is highly desirable. Designing of such a counters using existing technology i.e., CMOS technology has the limitations in-terms of power consumption, device scaling limitations andfabrications difficulties in nanometre range. This paper proposes the new design technique for modulo counters using the carbon nanotube field effect transistor (CNTFET. Counter performance is analyzed interms of speed and power consumption. This paper also analyses carbon nanotube (CNT types, how the carbon nanotube is formed, and scaling limitations of the CMOS technology in nanometre range.

  19. Microstructure and properties of vacuum counter-pressure cast aluminum alloy

    Directory of Open Access Journals (Sweden)

    YAN Qing-song

    2006-05-01

    Full Text Available The microstructure and properties of vacuum counter-pressure cast aluminum alloy were studied. Results indicated that under the condition of vacuum counter-pressure, liquid melts fill mould cavity under the vacuum and crystallize under high pressure which have very good effect on nucleation and solidification feeding. Compared with gravity casting, the microstructure of vacuum counter-pressure cast aluminum alloy is much finer and more uniformly distributed. Mechanical properties of vacuum counter-pressure cast aluminum alloy are improved significantly.

  20. An Improved Polar-Coordinate Navigation System with the Establishment of Electronic Counter-counter Measures Capabilities

    Directory of Open Access Journals (Sweden)

    Qiang Zhang

    2013-01-01

    Full Text Available With easy-to-be-disposed architecture and premium navigation performances, polar-coordinate navigationsystem (PCNS is still widely utilized by modern military navigation systems. Unfortunately, PCNS has very poor electronic counter-counter measures (ECCM performances, due to the lack of electronic warfare (EW considerations during its initial system design. To solve this problem, an improved PCNS (Imp-PCNS is proposed in this paper to introduce ECCM capabilities to PCNS. The low probability of intercept (LPI waveforms are utilized instead of regular pulses to reduce the probability of hostile interception. Both the bandwidth and the transmitted power of LPI are designed to generate the signals submerged under the thermal noises at the front ends of enemy receivers. Finally, a kinematic bearing method is proposed to dramatically reduce the possibility of intercept. The principle of kinematic bearing is analyzed in detail. An undistorted observed geometric position (OGP, which is independent ofthe deviation of observing angle, is achieved by controlling the rotation of the antenna array of PCNS beacon.Defence Science Journal, 2013, 63(1, pp.114-118, DOI:http://dx.doi.org/10.14429/dsj.63.2519

  1. An Improved Polar-Coordinate Navigation System with the Establishment of Electronic Counter-counter Measures Capabilities

    Directory of Open Access Journals (Sweden)

    Zhang Qiang

    2013-01-01

    Full Text Available With easy-to-be-disposed architecture and premium navigation performances, polar-coordinate navigation system (PCNS is still widely utilized by modern military navigation systems. Unfortunately, PCNS has very poor electronic counter-counter measures (ECCM performances, due to the lack of electronic warfare (EW considerations during its initial system design. To solve this problem, an improved PCNS (Imp-PCNS is proposed in this paper to introduce ECCM capabilities to PCNS. The low probability of intercept (LPI waveforms are utilized instead of regular pulses to reduce the probability of hostile interception. Both the bandwidth and the transmitted power of LPI are designed to generate the signals submerged under the thermal noises at the front ends of enemy receivers. Finally, a kinematic bearing method is proposed to dramatically reduce the possibility of intercept. The principle of kinematic bearing is analyzed in detail. An undistorted observed geometric position (OGP, which is independent of the deviation of observing angle, is achieved by controlling the rotation of the antenna array of PCNS beacon.

  2. Development of high-temperature fission counter chambers

    International Nuclear Information System (INIS)

    High-performance and 600 0C heat-resisting fission counter-chambers have been developed in which a fast counting gas is used, and satisfactory results have been obtained. The compatibility of the pulse output performance with the high-temperature resistivity of the chamber was investigated in connection with fast counting gases and structural metals, and the instability problem of the high-performance counter-chamber at high temperature was overcome using the combination of a mixed counting gas of 94 % argon, 5 % nitrogen and 1 % helium and the electrodes and structural metal-components made of a nickel alloy containing about 75 % nickel, 16 % chromium and some iron. The relivant works were performed successfully also in development of heat-resisting components and structures such as a metal-ceramic seal to be able to withstand the temperatures over 750 0C and an electrode supporting structure to enable to keep a narrow spacing between electrodes at high temperatures. Several types of such chambers have been made and tested to confirm their performance and operating stability at high temperatures. The test results showed that these fission counter-chambers operate quite stably at temperature up to 600 0C and have high-performance characteristics such as a very large neutron pulse current, e.g. of 2.6 μA and a short collection time, e.g. of 43 ns. It was also proved through the tests that the chambers have the ability to monitor about 10 decades of reactor operating range as a sensor of the nuclear instrumentation system of the nuclear power plant and withstand at least 6.5 x 1018 n/cm2 of neutron irradiation at 600 0C. Further, the chamber operated stably up to 800 0C in a post-accident monitoring(PAM) condition and withstood a long-term real-time in-reactor operating test at 600 0C for 3.3 years. (author)

  3. Design and Performance of INMAS Whole Body Counter

    Directory of Open Access Journals (Sweden)

    K. K. Kapoor

    1974-07-01

    Full Text Available A whole-body counter has been commissioned at INMAS for radiation protection and clinical applications including body potassium estimations. It has 4-crystal bed geometry inside a shielded enclosure. The background index of the system (counts per minute per cc detector volume in the energy band 0.1-2 me V is about 0.6 comparing favorably with other whole-body monitors in the world. The sensitivity is 0.5 cpm per gram of K. Body potassium can be estimated can be estimated correct to 10 g for one hour counting. The variation in detector response to a point source on the mid-line of the bed is + - 10% of the mean over a length of 170 cm. The usefulness of the large dimensions of the enclosure chosen is discussed.

  4. Surface micromachined counter-meshing gears discrimination device

    International Nuclear Information System (INIS)

    This paper discusses the design, fabrication and testing of a surface micromachined Counter-Meshing Gears (CMG) discrimination device which functions as a mechanically coded lock, A 24 bit code is input to unlock the device. Once unlocked, the device provides a path for an energy or information signal to pass through the device. The device is designed to immediately lock up if any portion of the 24 bit code is incorrect. The motivation for the development of this device is based on occurrences referred to as High Consequence Events, A High Consequence Event is an event where an inadvertent operation of a system could result in the catastrophic loss of life, property, or damage to the environment

  5. Abuse of over-the-counter dextromethorphan by teenagers.

    Science.gov (United States)

    Murray, S; Brewerton, T

    1993-10-01

    Dextromethorphan, the d-isomer of the opiate agonist levorphanol, has none of the analgesic or sedative effects associated with the opiates and is approved for over-the-counter use as an antitussive. It is available, in various combinations with other medications, in nonprescription cough suppressant and common cold formulations, and its availability in the United States is not controlled. In this paper we have reported two cases of recreational use of dextromethorphan-containing cough syrup by two unrelated teenage boys. Despite the safety of this medication when used at the recommended dosage, there have been cases of "recreational" use of dextromethorphan as well as death by overdose. Although usually thought to be nonaddictive, dextromethorphan produces a substance dependence syndrome, and physicians should be aware of its abuse potential, particularly by youths. PMID:8211334

  6. Fano factor implications from gas scintillation proportional counter measurements

    International Nuclear Information System (INIS)

    The Fano factor for xenon may be determined using a gas scintillation proportional counter in which the measured energy resolution is extrapolated to the condition of infinite light yield. The true Fano factor is expected to be independent of X-ray energy, photomultiplier type and gas pressure. Using both drifted and driftless GSPCs we have measured the Fano factor over a large range of X-ray energies (0.27-44.23 keV), photomultiplier types and gas pressures (351-878 hPa). In all three cases, when making the assumptions usually adopted in these determinations we find that the extrapolated Fano factor is dependent on the conditions. The implication is that other processes are also contributing to the measured resolution and that the determined values of the Fano factor are in fact upper limits. The Fano factor for xenon is found to be <0.12. (orig.)

  7. X-ray and gamma imaging with multiwire proportional counters

    International Nuclear Information System (INIS)

    The role of the Multiwire Proportional Counter (MWPC) as an X-ray image transducer in integrated digital imaging systems for use in a wide variety of fields (X-ray diffraction, medicine, non-destructive testing, etc.) is discussed with particular reference to the suitability of the technology for wider application than has been the case up to the present. A survey is given of the mechanical, electrical and electronic aspects of MWPC system design and the integration of this technology with microprocessor systems is examined. After a survey of the newer developments in the field of multiwire gaseous detectors it is concluded that this type of technology offers good potential for routine production of integrated digital X-ray imaging systems, possibly on a commercial basis. (orig.)

  8. Tension density as counter force to the Lorentz force density

    Science.gov (United States)

    Nozaki, Hiroo; Senami, Masato; Ichikawa, Kazuhide; Tachibana, Akitomo

    2016-08-01

    It is confirmed numerically that the tension density defined in quantum field theory is the counter force to the Lorentz force density. We take benzenedithiol in a nonequilibrium steady state as an example for the numerical demonstration of the balance between these densities. While we use simply a nonequilibrium Green’s function method for a quantum conduction state instead of computations based on quantum field theory, the balance between the tension density and the Lorentz force density can be confirmed. The tension density is free from the relaxation time ansatz and defined as a local quantity. The tension density may give a novel viewpoint to the understanding of the physics of electrical conduction.

  9. Countering Radicalisation of Muslim Community Opinions on the EU Level

    Directory of Open Access Journals (Sweden)

    Zięba Aleksandra

    2015-12-01

    Full Text Available The paper explores selected factors influencing the process of radicalisation leading to the use of political violence and terror by the Muslim minorities living in the European Union member states. Internal and external catalysts conditioning this process and methods of their analysis have been presented. The second section examines various counter-radicalisation and de-radicalisation efforts of the EU. The authors analysed the multidimensional European Union policy in the area of counteracting radicalisation for empowering the population and member states in preventing the radicalisation and recruitment to terrorism and emphasising the role of social partners and local authorities. Also, the promotion of good practices for combating radicalisation, developed under the auspices of the multidisciplinary Radicalisation Awareness Network (RAN is presented.

  10. Non-Imaging Detectors and Counters. Chapter 10

    International Nuclear Information System (INIS)

    Historically, nuclear medicine has been largely an imaging based specialty, employing such diverse and increasingly sophisticated modalities as rectilinear scanning, (planar) gamma camera imaging, single photon emission computed tomography (SPECT) and positron emission tomography (PET). Non-imaging radiation detection, however, remains an essential component of nuclear medicine. This chapter reviews the operating principles, performance, applications and quality control (QC) of the various non-imaging radiation detection and measurement devices used in nuclear medicine, including survey meters, dose calibrators, well counters, intra-operative probes and organ uptake probes. Related topics, including the basics of radiation detection, statistics of nuclear counting, electronics, generic instrumentation performance parameters and nuclear medicine imaging devices, are reviewed in depth in other chapters of this book

  11. Management of the Extreme Events: Countering International Terrorism

    Directory of Open Access Journals (Sweden)

    Dr. Cristian Barna

    2011-12-01

    Full Text Available After the terrorism attacks of September 11, 2001, there is recognition by both the public and private sectors that one needs to rethink our strategy for dealing with these low probability but extreme consequence events. September 11, 2001 attacks against the United States raised numerous questions related to counter-terrorism, foreign policy, as well as national security in the United States and abroad. They also raised the fundamental question of who should pay for losses due to terrorism.The question of who should pay for terrorism risk prevention and sustainable coverage within a country is likely to be seen first as a matter of collective responsibility that each country has to consider – a societal choice

  12. Flooding in vertical counter-current annular flow

    International Nuclear Information System (INIS)

    The hydrodynamic characteristics of falling liquid films inside a vertical tube (50.8 mm ID and 244 cm high) with counter-current interfacial shear at the onset of flooding have been investigated experimentally. High speed video photography and a flow visualization technique were utilized to investigate the mechanisms involved in the initiation of the flooding phenomenon over a wide range of liquid film Reynolds number (ReL=Γ4/μ) from 1391 to 6584 at a distance of 150 cm from the liquid inlet. The present experimental data indicated neither the interfacial wave growth nor reversal in the wave propagation could be responsible for the initiation of flooding. Also the measured velocity profiles indicated only a slight reduction in liquid velocity within a narrow region very close to the gas-liquid interface, and no flow reversal in the liquid film at the measurement location.

  13. Flooding in vertical counter-current annular flow

    International Nuclear Information System (INIS)

    The hydrodynamic characteristics of falling liquid films inside a vertical tube (50.8 mm ID and 244 cm high) with counter-current interfacial shear at the onset of flooding have been investigated experimentally. High speed video photography and a flow visualization technique were utilized to investigate the mechanisms involved in the initiation of the flooding phenomenon over a wide range of liquid film Reynolds number (ReL = 4Γ/μ) from 1391 to 6584 at a distance of 150 cm from the liquid inlet. The present experimental data indicated neither the interfacial wave growth nor reversal in the wave propagation could be responsible for the initiation of flooding. Also the measured velocity profiles indicated only a slight reduction in liquid velocity within a narrow region very close to the gas-liquid interface, and no flow reversal in the liquid film at the measurement location. (author)

  14. Monte Carlo studies of electron avalanches in microdosimetric proportional counters

    International Nuclear Information System (INIS)

    We present preliminary results from a study of electron avalanches in a low pressure cylindrical microdosimetric counter. The technique is based on the Monte Carlo simulation of the motion of electrons in electric field and their interactions with the molecules of gas. All the electrons are traced simultaneously in time and their coordinates and velocities are recorded. It lets us study all temporal and space aspects of the electron avalanche development. In this work we have concentrated on a study of the dependence of gain, radial extent and time extent of the avalanche on the gas pressure. We explain our results by the existence of seeding region in the avalanche where a relatively small number of secondary electrons are created. Each of these electrons gives subsequently rise to a partial avalanche in the proper avalanche region. (orig.)

  15. Source Lines Counter (SLiC) Version 4.0

    Science.gov (United States)

    Monson, Erik W.; Smith, Kevin A.; Newport, Brian J.; Gostelow, Roli D.; Hihn, Jairus M.; Kandt, Ronald K.

    2011-01-01

    Source Lines Counter (SLiC) is a software utility designed to measure software source code size using logical source statements and other common measures for 22 of the programming languages commonly used at NASA and the aerospace industry. Such metrics can be used in a wide variety of applications, from parametric cost estimation to software defect analysis. SLiC has a variety of unique features such as automatic code search, automatic file detection, hierarchical directory totals, and spreadsheet-compatible output. SLiC was written for extensibility; new programming language support can be added with minimal effort in a short amount of time. SLiC runs on a variety of platforms including UNIX, Windows, and Mac OSX. Its straightforward command-line interface allows for customization and incorporation into the software build process for tracking development metrics. T

  16. Manipulation of Particles with Counter-Propagating Evanescent Waves

    Institute of Scientific and Technical Information of China (English)

    Xiang YU; Takamasa TORISAWA; Norihiro UMEDA

    2007-01-01

    Two counter-propagating evanescent beams are used to align and manipulate polystyrene particles on a prism surface. Since the radiation pressure transferred laterally from the evanescent wave is negated on both sides,particles can be stably aligned. By projecting a circular and a linear beam spot onto the interface, both multiple and single arrays of particles are achieved. Arrays of particles trapped on the interface can be easily moved adjusting the intensity of incident beams on either side. We also simulate electromagnetic distribution of scattering light that is converted from the evanescent wave using the FDTD method. The results show that scattering light converts from an evanescent wave propagating through a particle array and has a distance longer than that propagating from a normal evanescent wave.

  17. The HERA-B Ring Imaging Cherenkov Counter

    CERN Document Server

    Arino, I

    2004-01-01

    The HERA-B RICH uses a radiation path length of 2.8 m in C_4F_10 gas and a large 24 square meters spherical mirror for imaging Cherenkov rings. The photon detector consists of 2240 Hamamatsu multi-anode photomultipliers with about 27000 channels. A 2:1 reducing two-lens telescope in front of each PMT increases the sensitive area at the expense of increased pixel size, resulting in a contribution to the resolution which roughly matches that of dispersion. The counter was completed in January of 1999, and its performance has been steady and reliable over the years it has been in operation. The design performance of the RICH was fully reached: the average number of detected photons in the RICH for a beta=1 particle was found to be 33 with a single hit resolution of 0.7 mrad and 1 mrad in the fine and coarse granularity regions, respectively.

  18. Spent fuel bundle counter sequence error manual - DARLINGTON NGS

    International Nuclear Information System (INIS)

    The Spent Fuel Bundle Counter (SFBC) is used to count the number and type of spent fuel transfers that occur into or out of controlled areas at CANDU reactor sites. However if the transfers are executed in a non-standard manner or the SFBC is malfunctioning, the transfers are recorded as sequence errors. Each sequence error message typically contains adequate information to determine the cause of the message. This manual provides a guide to interpret the various sequence error messages that can occur and suggests probable cause or causes of the sequence errors. Each likely sequence error is presented on a 'card' in Appendix A. Note that it would be impractical to generate a sequence error card file with entries for all possible combinations of faults. Therefore the card file contains sequences with only one fault at a time. Some exceptions have been included however where experience has indicated that several faults can occur simultaneously

  19. Conflict and complexity countering terrorism, insurgency, ethnic and regional violence

    CERN Document Server

    Bar-Yam, Yaneer; Minai, Ali

    2015-01-01

    Complexity science affords a number of novel tools for examining terrorism, particularly network analysis and NK-Boolean fitness landscapes as well as other tools drawn from non-linear dynamical systems modeling. This book follows the methodologies of complex adaptive systems research in their application to addressing the problems of terrorism, specifically terrorist networks, their structure and various methods of mapping and interdicting them as well as exploring the complex landscape of network-centric and irregular warfare. A variety of new models and approaches are presented here, including Dynamic Network Analysis, DIME/PMESII models, percolation models and emergent models of insurgency. In addition, the analysis is informed by practical experience, with analytical and policy guidance from authors who have served within the U.S. Department of Defense, the British Ministry of Defence as well as those who have served in a civilian capacity as advisors on terrorism and counter-terrorism.

  20. Counter-propagation neural network for image compression

    Science.gov (United States)

    Sygnowski, Wojciech; Macukow, Bohdan

    1996-08-01

    Recently, several image compression techniques based on neural network algorithms have been developed. In this paper, we propose a new method for image compression--the modified counter-propagation neural network algorithm, which is a combination of the self-organizing map of Kohonen and the outstar structure of Grossberg. This algorithm has been successfully used in many applications. The modification presented has also demonstrated an interesting performance in comparison with the standard techniques. It was found that at the learning stage we can use any image for a network training (without a significant influence on the net operation) and the compression ratio and quality depend on the size of the basic element (the number of pixels in the cluster) and the amount of error tolerated when processing.

  1. Calibration and optimization of proportional counter modules using Garfield

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Kiwhan [Los Alamos National Laboratory; Brockwell, Michael I [Los Alamos National Laboratory; Borozdin, Konstantin N [Los Alamos National Laboratory; Green, J Andrew [Los Alamos National Laboratory; Hogan, Gary E [Los Alamos National Laboratory; Makela, Mark F [Los Alamos National Laboratory; Mariam, Fesseha G [Los Alamos National Laboratory; Morris, Christopher L [Los Alamos National Laboratory

    2010-01-01

    Prototypes of radiation detector arrays used for charged-particle radiography require iniliol calibration to correlate the distribution of electron arrival time to the particle track locations. This step is crucial to obtaining the spatial resolution necessary to separate particle tracks traversing the individual proportional counters in the arrays. Our past attempts to use cosmic rays alone for the initial calibration have fallen short of obtaining the desired resolution due to the insufficient cosmic ray flux to provide the necessary number of particle tracks. A theoretical relation between electron drift time and radial drift distance is obtained with Garfield, a CERN gas detector simulation program. This relation is then used as an effective starting point for the initial calibration and results in a shorter calibration period and improved spatial resolution of the detectors.

  2. HML's whole body counter: measuring highly radioactive persons.

    Science.gov (United States)

    Kramer, Gary H; Capello, Kevin; Chiang, Albert; Hauck, Barry M

    2009-12-01

    The National Internal Radiation Assessment Section's Human Monitoring Laboratory (HML) has the responsibility to measure persons who may become internally contaminated following an accidental or intentional release of radioactivity. In preparation for measuring individuals who may be highly internally contaminated, the HML has reconfigured and recalibrated its whole body counter for this event. The calibration was performed using Monte Carlo simulations and validated by experimental measurements. An equation was developed that related the counting efficiency as a function of photon energy and phantom-to-detector distance. The equation could predict efficiencies to within 10% or better. Dead time problems, as a result of high internal activities, have been minimized by having a variety of counting positions. Six example nuclides have been used (Co, Co, Y, Ba, Cs, and Am) to show what is achievable and what is not. PMID:19901599

  3. Performance of an active well coincidence counter for HEU samples

    International Nuclear Information System (INIS)

    Neutron coincidence counting is the reference NDA technique used in nuclear safeguards to measure the mass of nuclear material in samples. For high-enriched uranium (HEU) samples active neutron interrogation is generally performed and the most common device used by nuclear inspectors is the Active Well Coincidence Counter (AWCC). Within her master thesis at the Polytechnic of Milan, the first author performed an intensive study on the characteristics and performances of the AWCC in order to assess the 235U mass in HEU oxide samples at the PERLA laboratory of JRC. The work has been summarised in this paper that starts with the optimisation of the use of AWCC for nuclear safeguards, describing the calibration procedure, reporting results of a series of verification measurements, summarising the performances that can be obtained with this instruments during inspections at fuel production plants and concluding with the discussion of uncertainties related to these measurements.

  4. Why Counter-terrorism Breeds Yet More Terrorism

    Institute of Scientific and Technical Information of China (English)

    Shen Jiru

    2006-01-01

    @@ The global campaign against terror has achieved considerable success over the past five years since the events of 9/11. The Taliban forces in Afghanistan have been destroyed and Al-Qeda has received a devastating blow. In Russia, Chechen secessionist terrorist forces have also suffered heavy losses. Nevertheless, the major terrorist attacks that took place in the UK, Spain, Russia, Iraq, India and Indonesia clearly demonstrate that terrorism has not yet disappeared.Terrorist attacks are on the increase, the targets are becoming more varied, and the methods more covert and more violent. Terrorist groups and organizations have become better organized in their activities and there is a trend towards the use of high-tech in the attacks.Some world public media refers to these phenomena as "counter-terrorism leading to yet more terrorism". Therefore, two fundamental questions may be posed to all countries throughout the world: What are the roots of terrorism? How can terrorism be eradicated?

  5. Calibration of the whole body counter at PSI

    International Nuclear Information System (INIS)

    At the Paul Scherrer Institut (PSI), measurements with the whole body counter are routinely carried out for occupationally exposed persons and occasionally for individuals of the population suspected of radioactive intake. In total about 400 measurements are performed per year. The whole body counter is based on a p-type high purity germanium (HPGe) coaxial detector mounted above a canvas chair in a shielded small room. The detector is used to detect the presence of radionuclides that emit photons with energies between 50 keV and 2 MeV. The room itself is made of iron from old railway rails to reduce the natural background radiation to 24 n Sv/h. The present paper describes the calibration of the system with the IGOR phantom. Different body sizes are realized by different standardized configurations of polyethylene bricks, in which small tubes of calibration sources can be introduced. The efficiency of the detector was determined for four phantom geometries (P1, P2, P4 and P6 simulating human bodies in sitting position of 12 kg, 24 kg, 70 kg and 110 kg, respectively. The measurements were performed serially using five different radionuclide sources (40K, 60Co, 133Ba, 137Cs, 152Eu) within the phantom bricks. Based on results of the experiment, an efficiency curve for each configuration and the detection limits for relevant radionuclides were determined. For routine measurements, the efficiency curve obtained with the phantom geometry P4 was chosen. The detection limits range from 40 Bq to 1000 Bq for selected radionuclides applying a measurement time of 7 min. The proper calibration of the system, on one hand, is essential for the routine measurements at PSI. On the other hand, it serves as a benchmark for the already initiated characterisation of the system with Monte Carlo simulations. (author)

  6. Dynamic Monitoring of Cleanroom Fallout Using an Air Particle Counter

    Science.gov (United States)

    Perry, Radford

    2011-01-01

    The particle fallout limitations and periodic allocations for the James Webb Space Telescope are very stringent. Standard prediction methods are complicated by non-linearity and monitoring methods that are insufficiently responsive. A method for dynamically predicting the particle fallout in a cleanroom using air particle counter data was determined by numerical correlation. This method provides a simple linear correlation to both time and air quality, which can be monitored in real time. The summation of effects provides the program better understanding of the cleanliness and assists in the planning of future activities. Definition of fallout rates within a cleanroom during assembly and integration of contamination-sensitive hardware, such as the James Webb Space Telescope, is essential for budgeting purposes. Balancing the activity levels for assembly and test with the particle accumulation rate is paramount. The current approach to predicting particle fallout in a cleanroom assumes a constant air quality based on the rated class of a cleanroom, with adjustments for projected work or exposure times. Actual cleanroom class can also depend on the number of personnel present and the type of activities. A linear correlation of air quality and normalized particle fallout was determined numerically. An air particle counter (standard cleanroom equipment) can be used to monitor the air quality on a real-time basis and determine the "class" of the cleanroom (per FED-STD-209 or ISO-14644). The correlation function provides an area coverage coefficient per class-hour of exposure. The prediction of particle accumulations provides scheduling inputs for activity levels and cleanroom class requirements.

  7. Compact multiwire proportional counters for the detection of fission fragments

    International Nuclear Information System (INIS)

    Two large area multistep position sensitive (two dimensional) multiwire proportional counters have been developed for experiments involving study of fission dynamics using general purpose scattering chamber facility at IUAC. Both detectors have an active area of 20x10 cm2 and provide position signals in horizontal (X) and vertical (Y) planes, timing signal for time of flight measurements and energy signal giving the differential energy loss in the active volume. The design features are optimized for the detection of low energy heavy ions at very low gas pressures. Special care was taken in setting up the readout electronics, constant fraction discriminators for position signals in particular, to get optimum position and timing resolutions along with high count rate handling capability of low energy heavy ions. A custom made charge sensitive preamplifier, having lower gain and shorter decay time, has been developed for extracting the differential energy loss signal. The position and time resolutions of the detectors were determined to be 1.1 mm full width at half maximum (FWHM) and 1.7 ns FWHM, respectively. The detector could handle heavy ion count rates exceeding 20 kHz without any breakdown. Time of flight signal in combination with differential energy loss signal gives a clean separation of fission fragments from projectile and target like particles. The timing and position signals of the detectors are used for fission coincidence measurements and subsequent extraction of their mass, angular, and total kinetic energy distributions. This article describes systematic study of these fission counters in terms of efficiency, time resolution, count rate handling capability, position resolution, and the readout electronics. The detector has been operated with both five electrode geometry and four electrode geometry, and a comparison has been made in their performances.

  8. PEDOT nanotube arrays as high performing counter electrodes for dye sensitized solar cells. Study of the interactions among electrolytes and counter electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Trevisan, Roberto; Boix, Pablo P.; Barea, Eva M.; Mora-Sero, Ivan; Bisquert, Juan [Photovoltaic and Optoelectronic Devices Group, Departament de Fisica, Universitat Jaume I, 12071 Castello (Spain); Doebbelin, Markus; Tena-Zaera, Ramon [CIDETEC-IK4, Parque Tecnologico de San Sebastian, Paseo Miramon 196, Donostia-San Sebastian, 20009 (Spain)

    2011-10-15

    PEDOT nanotube arrays present a better catalytic activity with I{sup -}/I{sub 3}{sup -} redox than standard platinized counter electrodes used for dye sensitized solar cells exhibiting thereby a photoconversion efficiency as high as 8.3%. The PEDOT layer introduces an additional series resistance which is compensated by its excellent catalytic performance yielding counter electrodes as good as platinized ones, or even better. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. A voltammetry study on the diffusion of counter ions in polypyrrole films

    DEFF Research Database (Denmark)

    Careem, M.A.; Velmurugu, Yogambigai; Skaarup, Steen;

    2006-01-01

    Polypyrrole (PPy) films doped with large immobile dodecyl benzene sulfonate (DBS) anions have been cycled in electrolytes of different concentration in an investigation of the diffusion of counter ions in this polymer complex. The diffusion of counter ions determines the speed of response of the ...

  10. Who You Callin' White?! A Critical Counter-Story on Colouring White Identity

    Science.gov (United States)

    Matias, Cheryl E.

    2013-01-01

    This action research, which utilizes critical race theory's counter-storytelling, analyses a process of debunking White students' epistemology of ignorance in a history course at an urban public high school. After piloting a raced curriculum that deliberately re-centers marginalized counter-stories of students of colour, I document its…

  11. Performance of microstrip proportional counters for x-ray astronomy on spectrum-roentgen-gamma

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Carl; BAHNSEN, A; Christensen, Finn Erland;

    1991-01-01

    DSRI will provide a set of four imaging proportional counters for the Danish-Soviet X-ray telescopes XSPECT/SODART. The sensor principle is based on the novel micro-strip proportional counter (MSPC), where the strip electrodes are deposited by photolithography onto a rigid substrate. The MSPC off...

  12. 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…

  13. Fuzzy Reasoning Methods by Choosing Different Fuzzy Counters and Analysis of Effect

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Different fuzzy reasoning methods were gave by choosing different fuzzy counters. This article generally introduced the basic structure of fuzzy controller,and compared and analysised the reasoning effect of fuzzy reasoning methods and the effect of computer simulating control basicly on different fuzzy counters.

  14. New proportional counter for in vivo detection of traces of plutonium in the lungs

    International Nuclear Information System (INIS)

    Development of a multi-wire proportional counter having a uniform response over 250 cm2 thanks to corrections made for boundary effects, and having a low background per sq. cm. due to the use of two identical counters set in anti-coincidence in the same enclosure is described. (author)

  15. The gas amplification factor in Kr + iso-pentane filled proportional counters

    International Nuclear Information System (INIS)

    Measurements of gas amplification in a proportional counters with Kr/iso-pentane mixture were performed at pressures ranging from 160 to 970 hPa. A new formula for gas amplification in a proportional counters was derived. A good agreement between the formula and experimental data was found over the range of variables studied. 16 refs., 4 figs., 1 tab. (author)

  16. Development of High Pressure Xe Scintillation Proportional Counter for Experiments in "Low-Background" Physics

    OpenAIRE

    Akimov, D. Yu.; Burenkov, A.A.; Churakov, D. L.; Kuzichev, V. F.; Morgunov, V. L.; Smirnov, G. N.; Solovov, V. N.

    1997-01-01

    Characteristics of a scintillation proportional counter with WLS fiber optics readout is described. The possibility of detection of the proportional scintillation signal produced by the single electron of primary ionization is shown. The counter can be applied for the experiments in "low--background" physics which require a low energy threshold.

  17. A versatile two-dimensional backgammon-drift chamber for transmission trajectory counter

    International Nuclear Information System (INIS)

    In the present paper, the design, the structure and the performance of two-dimensional position sensitive gas counter are described. This counter system is now tested to develop as a neutron detector with a new backgammon-shaped electrode pattern. (J.P.N.)

  18. Study on energy response of GM counter tube-type instrument

    International Nuclear Information System (INIS)

    The author describes the method and applied occasion of two different concepts for evaluating energy response of GM counter tube-type instrument. It gives energy response data with different thickness of lead sheathing and exposed ratio of sensitive area of counter tube. The optimum values of thickness of lead sheathing and sensitive area are recommended

  19. Drag and lift forces on a counter-rotating cylinder in rotating flow

    NARCIS (Netherlands)

    Sun, Chao; Mullin, Tom; Wijngaarden, van Leen; Lohse, Detlef

    2010-01-01

    Results are reported of an experimental investigation into the motion of a heavy cylinder free to move inside a water-filled drum rotating around its horizontal axis. The cylinder is observed to either co-rotate or, counter-intuitively, counter-rotate with respect to the rotating drum. The flow was

  20. New data about dielectric breakdown counters on the MOS-structure base for heavy ion detection

    International Nuclear Information System (INIS)

    The fabrication technology of dielectric break-down counters based on a MOS structure and designed to record heavy ions is described. To produce counters use was made of low-resistant n-Si. The MOS structure was obtained by the method of thermal growing of a layer of SiO2 having a thickness of 1400 A on a chemically polished surface of the sample with further spraying of a forward aluminium electrode with a thickness of 500 A. One Si sample accomodated several counters. The rear electrode consisting in a layer of Al was common to all counters. By using the above-mentioned technology dielectric breakdown counters have been produced with a total area of the sensitive surface of up to 110 cm2. Results of investigations of such important counter characteristics as the detection efficiency, stability, reliability and reproducibility of counting characteristics in the process of counter fabrication are given. It has been found that the detection efficiency constitutes approximately 100%. The value of specific energy losses in SiO2, at which detection of heavy ions is still possible, is equal to 22+-2 MeVxcm2/mg. The maximum service life of counters in detecting fission fragments constituted approximately 3x10 cm-2. The results of multi-day tests of breakdown detectors showed good stability of their counting characteristics and efficiency

  1. Watch dog of the atomic era. Geiger counters in the history of the radiation protection

    International Nuclear Information System (INIS)

    The following topics are dealt with: The radioactivity laboratory of the Physikalisch-Technische Reichsanstalt, optical and electrical counting methods and ways to the Geiger-Mueller counting tube, scintillation countings, Geiger's tip counter, the Geiger-Mueller counting tube, the radioactivity laboratory of the Physikalisch-Technische Bundesanstalt, populary Geiger counters and the trivialization and polarization of radiation measurements. (HSI)

  2. Low geometry counter for the absolute measurement of the activity of alpha-emitting sources

    International Nuclear Information System (INIS)

    A low-geometry counter is described which allows the absolute determination of the activity for alpha-emitting sources. A Si implanted detector is used to obtain the spectrum of the sample. Two samples are measured with this counter and a 2 π gridded ion chamber. The results an their uncertainties for both instruments are discussed. (Author)

  3. National survey of human body radioactivity measured by a mobile whole-body counter and installed whole-body counters

    International Nuclear Information System (INIS)

    Body radioactivity in the general public has been measured in 2339 volunteers throughout the U.K. A mobile whole-body monitor visited collaborating Medical Physics Departments and data were also contributed by Medical Physics Departments possessing installed counters. Levels of body radiocaesium ranged from below detection level to 4149 Bq. Radiocaesium levels were normalised by dividing by the content of natural body potassium-40. In all cases, the dose rate to the body from radiocaesium was less than that from potassium-40. Radiocaesium levels were 2-3 times higher in N.W. England, Scotland and N. Wales than the rest of the country, but this factor is much less than the variation in deposition of Chernobyl radiocaesium. This discrepancy may be accounted for by the nationwide distribution of foodstuffs. At all sites where volunteers were monitored, the ratio of caesium-137/caesium-134 was consistent with a radiocaesium intake attributable primarily to fallout from the Chernobyl fire. (author)

  4. Shielding concepts for low-background proportional counter arrays in surface laboratories

    CERN Document Server

    Aalseth, Craig E; Mace, Emily K; Orrell, John L; Seifert, Allen; Williams, Richard M

    2015-01-01

    Development of ultra low background gas proportional counters has made the contribution from naturally occurring radioactive isotopes -- primarily $\\alpha$ and $\\beta$ activity in the uranium and thorium decay chains -- inconsequential to instrumental sensitivity levels when measurements are performed in above ground surface laboratories. Simple lead shielding is enough to mitigate against gamma rays as gas proportional counters are already relatively insensitive to naturally occurring gamma radiation. The dominant background in these surface laboratory measurements using ultra low background gas proportional counters is due to cosmic ray generated muons, neutrons, and protons. Studies of measurements with ultra low background gas proportional counters in surface and underground laboratories as well as radiation transport Monte Carlo simulations suggest a preferred conceptual design to achieve the highest possible sensitivity from an array of low background gas proportional counters when operated in a surface...

  5. A Cherenkov counter designed as a muon trigger for the SDC detector

    International Nuclear Information System (INIS)

    A test of a gas Cherenkov counter was performed at Fermilab in the High Energy Muon Lab in order to understand its performance as a trigger counter for muons above a given momentum. This counter was built so that it could rotate relative to the beam direction to simulate the bending of muon tracks in the toroidal magnet of the Solenoidal Detector Collaboration (SDC) being designed for use at the Superconducting Super Collider (SSC). The SDC Cherenkov counter is so designed that a high momentum muon would emit Cherenkov light that is focussed on the face of a photomultiplier tube while a low momentum muon in the forward element of the SDC detector is bent to large enough angles so that the light is focussed away from the photomultiplier tube. We present the observed changes in pulse height as the counter is rotated and the simulated resultant trigger efficiency for a given photomultiplier output pulse. (orig.)

  6. The Performance and Long Term Stability of the D0 Run II Forward Muon Scintillation Counters

    Energy Technology Data Exchange (ETDEWEB)

    Bezzubov, V. [Serpukhov, IHEP; Denisov, D. [Fermilab; Evdokimov, V. [Serpukhov, IHEP; Lipaev, V. [Serpukhov, IHEP; Shchukin, A. [Serpukhov, IHEP; Vasilyev, I. [Serpukhov, IHEP

    2014-07-21

    The performance of the D0 experiment forward muon scintillation counters system during Run II of the Tevatron from 2001 to 2011 is described. The system consists of 4214 scintillation counters in six layers. The long term stability of the counters amplitude response determined using LED calibration system and muons produced in proton-antiproton collisions is presented. The average signal amplitude for counters of all layers has gradually decreased over ten years by 11%. The reference timing, determined using LED calibration, was stable within 0.26 ns. Average value of muon timing peak position was used for periodic D0 clock signal adjustments to compensate seasonal drift caused by temperature variations. Counters occupancy for different triggers in physics data collection runs and for minimum bias triggers are presented. The single muon yields versus time and the luminosity dependence of yields were stable for the forward muon system within 1% over 10 years.

  7. 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.

  8. Alcohol counter-advertising and the media. A review of recent research.

    Science.gov (United States)

    Agostinelli, Gina; Grube, Joel W

    2002-01-01

    Counter-advertising commonly is used to balance the effects that alcohol advertising may have on alcohol consumption and alcohol-related problems. Such measures can take the form of print or broadcast advertisements (e.g., public service announcements [PSAs]) as well as product warning labels. The effectiveness of both types of counter-advertising is reviewed using the Elaboration Likelihood Model as a theoretical framework. For print and broadcast counter-advertisements, such factors as their emotional appeal and the credibility of the source, as well as audience factors, can influence their effectiveness. Further, brewer-sponsored counter-advertisements are evaluated and received differently than are the more conventional PSA counter-advertisements. For warning labels, both the content and design of the label influence their effectiveness, as do audience factors. The effectiveness of those labels is evaluated in terms of the extent to which they impact cognitive and affective processes as well as drinking behavior. PMID:12154647

  9. The alignment and measurement of the magnetic field for muon counter at BESIII

    CERN Document Server

    Gao, Qing; Li, Chunhua

    2016-01-01

    Based on cosmic ray events taken without magnet filed during summer shutdown, we compare the coordinates of hits in muon counter with the expected interaction point of extrapolated tracks from the inner tracking system. By minimizing the difference, we align the muon counter with the inner tracking system. The muon counter is operating in magnetic return yoke and the magnetic field has never been measured before. The strength of the magnetic field of the muon counter is measured for the first time with $\\mu^+$ and $\\mu^-$ separately. After the alignment and magnetic field measurement, the offsets of hit-position for $\\mu^+$ and $\\mu^-$ are diminished. The alignment and magnetic field measurement are adopted in the latest BESIII offline software system. This makes physics analysis involving muon counter information more reliable.

  10. Theory of electronic structure and nuclear quadrupole interactions in the BF3-NH3 complex and methyl derivatives

    Science.gov (United States)

    Pink, R. H.; Dubey, Archana; Mahato, Dip N.; Badu, S. R.; Scheicher, R. H.; Mahanti, Mahendra K.; Huang, M. B.; Saha, H. P.; Chow, Lee; Das, T. P.

    Magnetic Hyperfine and Nuclear Quadrupole Interactions (HPI and NQI) are now important tools for characterization of systems of interest in materials research and industry. Boron-Trifluoride is an inorganic compound that is very important in this respect as a catalyst in chemical physics research and industry, forming complexes in the process with compounds like ammonia, water and methyl alcohol. The present paper deals with the BP3-NH3 complex and methyl derivatives BP3NHx(CH3)3-x for which we have studied the electronic structures, binding energies, and 19F* (I=5/2) nuclear quadrupole interactions using the first-principles Hartree-Fock-Roothaan procedure combined with electron correlation effects. Our results for the 19F* nuclear quadrupole coupling constant (e 2qQ/h) in units of MHz compare well with experiment. Trends in the binding energies and NQI parameters between the complexes are discussed.

  11. BF3-catalyzed methanolysis combined with FAB tandem mass spectrometry as a new tool for sequencing of cyclosporins

    Czech Academy of Sciences Publication Activity Database

    Havlíček, Vladimír; Jegorov, A.; Sedmera, Petr; Ryska, M.

    Barcelona : Grupo de Cromatografia y Tecnicas Afines, 1995, s. 7. [International Symposium on Applied Mass Spectrometry in the Health Sciences - European Tandem Mass Spectrometry Conference /3./. Barcelona (ES), 09.07.1995-13.07.1995

  12. [Methodological Approaches to the Organization of Counter Measures Taking into Account Landscape Features of Radioactively Contaminated Territories].

    Science.gov (United States)

    Kuznetsov, V K; Sanzharova, N I

    2016-01-01

    Methodological approaches to the organization of counter measures are considered taking into account the landscape features of the radioactively contaminated territories. The current status and new requirements to the organization of counter measures in the contaminated agricultural areas are analyzed. The basic principles, objectives and problems of the formation of counter measures with regard to the landscape characteristics of the territory are presented; also substantiated are the organization and optimization of the counter measures in radioactively contaminated agricultural landscapes. PMID:27245009

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

    International Nuclear Information System (INIS)

    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

  14. 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.

  15. Nanodosimetry of heavy ions using a miniature cylindrical counter of wall-less design

    International Nuclear Information System (INIS)

    During the last few years, some new developments in experimental microdosimetry using a highly miniaturised walled cylindrical counter called the ''UMC'' have been reported. Tests of counter gain and linearity indicated ''normal'' proportional counter operation down to about 10 nm. More recently, a small cylindrical counter of the same design as the UMC has been built, but of the ''wall-less'' variety, i.e. the collecting volume is defined by a cylindrical helix rather than a solid wall. The dimensions of this counter are 3.18 mm diameter by 3.18 mm height. This has made possible tests of this design with heavy ion beams of fixed LET. Such beams have the advantage that the energy deposition spectrum is particularly simple. Since there is minimal LET spread, spectral shape is determined only by ionisation statistics and counter response (resolution). Theoretical analysis and modelling of such spectra are much easier and more reliable than for neutrons and energetic photons. In this paper heavy ion spectra at both high and low LET are presented and compared with theoretical predictions, and it is demonstrated that this counter produced reliable and acceptable spectra down to at least 20 nm. (Author)

  16. Nanodosimetry of heavy ions using a miniature cylindrical counter of wall-less design

    Energy Technology Data Exchange (ETDEWEB)

    Kliauga, P. (Columbia Univ., New York, NY (United States). Coll. of Physicians and Surgeons)

    1994-01-01

    During the last few years, some new developments in experimental microdosimetry using a highly miniaturised walled cylindrical counter called the ''UMC'' have been reported. Tests of counter gain and linearity indicated ''normal'' proportional counter operation down to about 10 nm. More recently, a small cylindrical counter of the same design as the UMC has been built, but of the ''wall-less'' variety, i.e. the collecting volume is defined by a cylindrical helix rather than a solid wall. The dimensions of this counter are 3.18 mm diameter by 3.18 mm height. This has made possible tests of this design with heavy ion beams of fixed LET. Such beams have the advantage that the energy deposition spectrum is particularly simple. Since there is minimal LET spread, spectral shape is determined only by ionisation statistics and counter response (resolution). Theoretical analysis and modelling of such spectra are much easier and more reliable than for neutrons and energetic photons. In this paper heavy ion spectra at both high and low LET are presented and compared with theoretical predictions, and it is demonstrated that this counter produced reliable and acceptable spectra down to at least 20 nm. (Author).

  17. THE COUNTER-JET FORMATION IN AN AIR BUBBLE INDUCED BY THE IMPACT OF SHOCK WAVES

    Institute of Scientific and Technical Information of China (English)

    BAI Li-xin; XU Wei-lin; LI Chao; GAO Yan-dong

    2011-01-01

    The interaction of an air bubble (isolated in water or attached to a boundary) with shock waves induced by electric sparks is investigated by high-speed photography.The interaction is closely related to the counter-jet induced by the impact of shock waves.The formation of a counter-jet in an air bubble is related to the liquid jet formed in the same air bubble,but the mechanism is different with that of the counter-jet formation in a collapsing cavitation bubble.The formation of a counter-jet in an air bubble is related to discharge energy,air bubble size and radius of shock wave.With a given energy of the spark discharge,the formation of a counter-jet in an air bubble is related to δ/ε (the ratio of the dimensionless bubble-bubble distance to the dimensionless air bubble radius).The counter-jet will only be produced when δ/ε is in the range of 1.2-2.2.The counter-jet in an air bubble is of an important nuclei-generating mechanism.

  18. Dye-sensitized solar cells based on low cost carbon-coated tungsten disulphide counter electrodes

    International Nuclear Information System (INIS)

    Highlights: •Carbon-coated WS2 films are used as the counter electrode in dye-sensitized solar cells. •The plastic carbon-coated WS2 counter electrodes are prepared at room temperature. •The device with carbon-coated WS2 electrode exhibits comparable performance to that of the cell with Pt electrode. -- Abstract: Carbon-coated tungsten disulphide (WS2) is synthesized using a simple method and characterized with X-ray diffraction, field emission scanning electron microscopy and laser Raman spectrum. The WS2-based counter electrodes for dye-sensitized solar cells (DSSCs) are prepared at low temperature. The electrochemical catalytic activity of the WS2 counter electrodes is investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The DSSCs assembled with carbon-coated WS2 counter electrodes show a photovoltaic conversion efficiency of 5.5%, which is comparable to that of the DSSCs based on Pt electrode (5.6%). Plastic WS2 counter electrodes are also prepared which give a photovoltaic conversion efficiency of 5.0%. Our study indicates that carbon-coated WS2 is a good candidate to replace the Pt counter electrodes in DSSCs

  19. Light interference detection on-chip by integrated SNSPD counters

    Directory of Open Access Journals (Sweden)

    Paul Cavalier

    2011-12-01

    Full Text Available A SWIFTS device (Stationary Wave Integrated Fourier Transform Spectrometer has been realized with an array of 24 Superconducting Nanowire Single Photon Detectors (SNSPD, on-chip integrated under a Si3N4 monomode rib-waveguide interferometer. Colored light around 1.55μm wavelength is introduced through end-fire coupling, producing a counter-propagative stationary interferogram over the 40nm wide, 120nm spaced, 4nm thick epi-NbN nanowire array. Modulations in the source bandwidth have been detected using individual waveguide coupled SNSPDs operating in single photon counting mode, which is a step towards light spectrum reconstruction by inverse Fourier transform of the stationary wave intensity. We report the design, fabrication process and in-situ measurement at 4.2K of light power modulation in the interferometer, obtained with variable laser wavelength. Such micro-SWIFTS configuration with 160nm sampling period over 3.84μm distance allows a spectral bandwidth of 2μm and a wavelength resolution of 170nm. The light interferences direct sampling ability is unique and raises wide interest with several potential applications like fringe-tracking, metrology, cryptography or optical tomography.

  20. Gas flow counter conversion electron Moessbauer spectroscopy (GFC-CEMS)

    International Nuclear Information System (INIS)

    Conversion Electron Moessbauer Spectroscopy (CEMS) is well established technique to study surface properties of materials. However non availability of commercial experimental set up and complexity of operational parameters have been restricting the working experimental groups with in the country and abroad. In this paper we have presented the development work for the design of Gas Flow Counter (GFC), e.g. convenient sample mount, grounding, steady flow rate adjustment and minimum He-losses so that the detector operation and installation becomes convenient and dependable. The basic design is modified e.g. large volume to maintain steady gas flow, sample mount close to central wire and O-ring fitted flange. The CEMS spectra are recorded using conventional Moessbauer drive and 57Co source. The calibrated spectrum shows a detection efficiency of about 20% for natural iron and steel foil. The CEMS spectrum for FeTi bulk and transmission Moessbauer Spectroscopy (TMS) spectrum of FeTi thin film deposited by vacuum evaporation on thin glass substrate were recorded to test the performance of GFC-CEMS. (author)