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Sample records for previously measured reaction

  1. Charged-Particle Thermonuclear Reaction Rates: IV. Comparison to Previous Work

    OpenAIRE

    Iliadis, Christian; Longland, Richard; Champagne, Art; Coc, Alain

    2010-01-01

    We compare our Monte Carlo reaction rates (see Paper II of this series) to previous results that were obtained by using the classical method of computing thermonuclear reaction rates. For each reaction, the comparison is presented using two types of graphs: the first shows the change in reaction rate uncertainties, while the second displays our new results normalized to the previously recommended reaction rate. We find that the rates have changed significantly for almost all reactions conside...

  2. Charged-particle thermonuclear reaction rates: IV. Comparison to previous work

    International Nuclear Information System (INIS)

    Iliadis, C.; Longland, R.; Champagne, A.E.; Coc, A.

    2010-01-01

    We compare our Monte Carlo reaction rates (see Paper II of this issue) to previous results that were obtained by using the classical method of computing thermonuclear reaction rates. For each reaction, the comparison is presented using two types of graphs: the first shows the change in reaction rate uncertainties, while the second displays our new results normalized to the previously recommended reaction rate. We find that the rates have changed significantly for almost all reactions considered here. The changes are caused by (i) our new Monte Carlo method of computing reaction rates (see Paper I of this issue), and (ii) newly available nuclear physics information (see Paper III of this issue).

  3. Reactions to small pox vaccine in naïve and previously-vaccinated individuals.

    Science.gov (United States)

    Auckland, Cressida; Cowlishaw, Alexandra; Morgan, Dilys; Miller, Elizabeth

    2005-07-14

    Two hundred health care workers in England and Wales were vaccinated with the Lister/Elstree strain of the vaccinia virus, and completed health diaries for 21 days or until the lesion had scabbed over. Pain and temperature were measured daily, and all other symptoms recorded freehand by the vaccinee. One hundred and forty two (71%) vaccinees reported pain, of which 25% considered it to be moderate or severe; 32 vaccinees (16%) recorded a temperature of >37.7 degrees C, two of which exceeded 39 degrees C. Other, mainly trivial, adverse events were common; itch was reported in 72%, erythema in 27%, axillary pain or lymphadenopathy in 38%, malaise or flu-like symptoms in 40% and headache in 23%. The incidences of minor adverse events were lower in re-vaccinees, compared with naïve vaccine recipients, significantly so in the case of erythema and general malaise (p=0.001 and 0.006, respectively), perhaps reflecting pre-existing immunity. Major adverse events occurred in two vaccinees (hospital admission, one with cellulitis and one with headache and possible encephalitis), and a further five were treated with antibiotics for local cellulitis. This is the first study to report results derived from active follow-up by diaries in recipients of the Lister/Elstree strain of vaccinia, and to document reductions in trivial adverse events in re-vaccinees.

  4. Measurement of Proton-Induced Transfer Reactions with JENSA

    Science.gov (United States)

    Chatterjee, Sidharth; Chipps, Kelly; Pain, Steven; Cizewski, Jolie; Jensa Collaboration

    2017-09-01

    Reaction measurements of radioactive nuclei on light targets are important to understanding the origin of and the trends in the structure of nuclei. To efficiently measure nuclear reactions, measurements require highly localized and pure light targets and need to accommodate arrays of light charged particles, gamma rays, and recoiling heavy ions. The Jet Experiments in Nuclear Structure and Astrophysics (JENSA) jet target system was designed to facilitate high resolution, low background nuclear reaction studies. To demonstrate the capability of the JENSA system, the 20Ne(p,3He)18F reaction was studied during the commissioning phase. The radioisotope 18F is one of the galactic gamma-ray sources targeted by next-generation space-based telescopes. In addition, the 20Ne(p,3He) reaction has not been previously used for the spectroscopic study of 18F. The JENSA system gives us the opportunity to study this reaction with high resolution and low background. The measurement was performed with a proton beam from the Holifield Radioactive Ion Beam Facility tandem on a neon jet of natural isotopic abundance from JENSA. The experimental setup of JENSA and preliminary results will be discussed. Oak Ridge National Laboratory; Rutgers University Department of Physics and Astronomy.

  5. $^{12}$C nuclear reaction measurements for hadrontherapy.

    CERN Document Server

    B. Braunn, B; G. Ban, G; J.Colin, J; D. Cussol, D; J.M. Fontbonne, J M; F.R.. Lecolley, F R; C. Pautard, C; Haas, F; Lebhertz, D; Rousseau, M; Stuttge, L; Chevallier, M; Dauvergne, D; Le Foulher, F; Ray, C; Testa, E; Testa, M; Salsac, M D

    2010-01-01

    Hadrontherapy treatments require a very high precision on the dose deposition ( 2.5% and 1-2mm) in order to keep the benefits of the precise ions’ ballistic. The largest uncertainty on the physical dose deposition is due to ion fragmentation. Up to now, the simulation codes are not able to reproduce the fragmentation process with the required precision. To constraint the nuclear models and complete fragmentation cross sections databases; our collaboration has performed an experiment on May 2008 at GANIL with a 95 MeV/u 12C beam. We have measured the fluence, energy and angular distributions of charged fragments and neutrons coming from nuclear reactions of incident 12C on thick water-like PMMA targets. Preliminary comparisons between GEANT4 (G4BinaryLightIonReaction) simulations and experimental data show huge discrepancies.

  6. Tuberculine reaction measured by infrared thermography.

    Science.gov (United States)

    Fiz, José Antonio; Lozano, Manuel; Monte-Moreno, Enrique; Gonzalez-Martinez, Adela; Faundez-Zanuy, Marcos; Becker, Caroline; Pons-Rodriguez, Laura; Ruiz Manzano, Juan

    2015-11-01

    The infection with Mycobacterium tuberculosis gives a delayed immune response, measured by the tuberculine skin test. We present a new technique for evaluation based on automatic detection and measurement of skin temperature due to infrared emission. 34 subjects (46.8±16.9 years) (12/22, M/F) with suspected tuberculosis disease were examined with an IR thermal camera, 48 h after tuberculin skin injection. In 20 subjects, IR analysis was positive for tuberculine test. Mean temperature of injection area was higher, around 1°C, for the positive group (36.2±1.1°C positive group; 35.1±1.6°C negative group, p<0.02 T test for unpaired groups). IR image analysis achieves similar estimation of tuberculin reaction as the visual evaluation, based on higher temperature due to increased heat radiation from the skin lesion. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Void Measurement by the (γ, n) Reaction

    International Nuclear Information System (INIS)

    Rouhani, S. Zia

    1962-09-01

    It is proposed to use the (γ, n) reaction for the measurement of the integrated void volume fraction in two phase flow of D 2 O inside a duct. This method is applicable to different channel geometries, and it is shown to be insensitive to the pattern of void distribution over the cross-sectional area of the channels The method has been tested on mock-ups of voids in a round duct of 6 mm inside diameter. About 40 m.c. 24 Na was used as a source of gamma-rays. The test results show that the maximum measured error in this arrangement is less than 2.5 % (net void) for a range of 2.7 % to 44.44 % actual void volume fractions

  8. Electrochemical Measurements in Cement Extract Solutions on Reinforcing Steel, Previously Conditioned in Concrete

    NARCIS (Netherlands)

    Koleva, D.A.; De Wit, J.H.W.; Van Breugel, K.; Bachvarov, V.; Kolev, H.; Fraaij, A.

    2007-01-01

    The corrosion behavior of reinforcing steel, previously embedded in concrete and maintained in conditions of corrosion and two regimes (conventional and pulse) of cathodic protection (CP), was characterized using electrochemical measurements in cement extract (CE) solutions of pH 12.6. The

  9. STUDY OF INFLUENCE OF PREVIOUS ORAL APPLICATION OF DIPHTHERIA ANTIGENIC PREPARATIONS ON RABBIT ALLERGIC REACTION FORMING AFTER SKIN TEST

    Directory of Open Access Journals (Sweden)

    Babych YeM

    2013-03-01

    Full Text Available It’s studied an influence of previous oral application of diphtheria antigenic preparations on allergic inflammation forming after skin test. It’s used destroyed by ultrasonic microbe cells C.diphtheriae var. gravis tox+ massachusets, free from destroyed cells by the use of centrifugation supernatant and refined concentrated diphteria toxoid. Experimental rabbits are fed to 3,5 ml of one of antigenic preparations (the total protein dose is 33,6 mg, control ones are fed to saline. In a week all animals were injected intracutaneously 0,2 ml each of corresponding antigenic preparation. The findings testify to decreasing manifestation tendency of rabbit skin reactions on antigenic preparations.

  10. Comparison between Conventional Blind Embryo Transfer and Embryo Transfer Based on Previously Measured Uterine Length

    Directory of Open Access Journals (Sweden)

    Nasrin Saharkhiz

    2014-11-01

    Full Text Available Background: Embryo transfer (ET is one of the most important steps in assisted reproductive technology (ART cycles and affected by many factors namely the depth of embryo deposition in uterus. In this study, the outcomes of intracytoplasmic sperm injection (ICSI cycles after blind embryo transfer and embryo transfer based on previously measured uterine length using vaginal ultrasound were compared. Materials and Methods: This prospective randomised clinical trial included one hundred and forty non-donor fresh embryo transfers during January 2010 to June 2011. In group I, ET was performed using conventional (blind method at 5-6cm from the external os, and in group II, ET was done at a depth of 1-1.5 cm from the uterine fundus based on previously measured uterine length using vaginal sonography. Appropriate statistical analysis was performed using Student’s t test and Chi-square or Fisher’s exact test. The software that we used was PASW statistics version 18. A p value <0.05 was considered statistically significant. Results: Chemical pregnancy rate was 28.7% in group I and 42.1% in group II, while the difference was not statistically significant (p=0.105. Clinical pregnancy, ongoing pregnancy and implantation rates for group I were 21.2%, 17.7%, and 12.8%, while for group II were 33.9%, 33.9%, and 22.1, respectively. In group I and group II, abortion rates were 34.7% and 0%, respectively, indicating a statistically significant difference (p<0.005. No ectopic pregnancy occurred in two groups. Conclusion: The use of uterine length measurement during treatment cycle in order to place embryos at depth of 1-1.5cm from fundus significantly increases clinical and ongoing pregnancy and implantation rates, while leads to a decrease in abortion rate (Registration Number: IRCT2014032512494N1.

  11. Measurement of two-peak structure in fusion reaction history

    International Nuclear Information System (INIS)

    Wang Feng; Peng Xiaoshi; Liu Shenye; Liu Yonggang; Xu Tao; Chen Ming; Mei Yu; Kang Dongguo; Gu Jianfa

    2013-01-01

    The relationship of the roughness degree of ablation shell and the two peaks of fusion reaction rate was analyzed. We developed a system for fusion reaction history measurement with high temporal resolution, and applied this system to the SG-Ⅲ prototype for measuring fusion reaction rate. Fusion reaction rate history was measured for the first time with deuterium-tritium filled targets under neutron yields of about 10 10 . We anatomized possible influence factors during fusion reaction rate's measuring. The two peaks of reaction rate can be obtained from the simulation results, and have been confirmed with the experimental results. It is found that neutrons in our experiment are generated by the first peak which is called the shock peak. The simulation and experimental results can provide strong technical support for the research on fusion reaction rate in inertial confinement fusion. (authors)

  12. The impact of previous knee injury on force plate and field-based measures of balance.

    Science.gov (United States)

    Baltich, Jennifer; Whittaker, Jackie; Von Tscharner, Vinzenz; Nettel-Aguirre, Alberto; Nigg, Benno M; Emery, Carolyn

    2015-10-01

    Individuals with post-traumatic osteoarthritis demonstrate increased sway during quiet stance. The prospective association between balance and disease onset is unknown. Improved understanding of balance in the period between joint injury and disease onset could inform secondary prevention strategies to prevent or delay the disease. This study examines the association between youth sport-related knee injury and balance, 3-10years post-injury. Participants included 50 individuals (ages 15-26years) with a sport-related intra-articular knee injury sustained 3-10years previously and 50 uninjured age-, sex- and sport-matched controls. Force-plate measures during single-limb stance (center-of-pressure 95% ellipse-area, path length, excursion, entropic half-life) and field-based balance scores (triple single-leg hop, star-excursion, unipedal dynamic balance) were collected. Descriptive statistics (mean within-pair difference; 95% confidence intervals) were used to compare groups. Linear regression (adjusted for injury history) was used to assess the relationship between ellipse-area and field-based scores. Injured participants on average demonstrated greater medio-lateral excursion [mean within-pair difference (95% confidence interval); 2.8mm (1.0, 4.5)], more regular medio-lateral position [10ms (2, 18)], and shorter triple single-leg hop distances [-30.9% (-8.1, -53.7)] than controls, while no between group differences existed for the remaining outcomes. After taking into consideration injury history, triple single leg hop scores demonstrated a linear association with ellipse area (β=0.52, 95% confidence interval 0.01, 1.01). On average the injured participants adjusted their position less frequently and demonstrated a larger magnitude of movement during single-limb stance compared to controls. These findings support the evaluation of balance outcomes in the period between knee injury and post-traumatic osteoarthritis onset. Copyright © 2015 Elsevier Ltd. All rights

  13. Direct measurement of the reaction front in chemically amplified photoresists.

    Science.gov (United States)

    Lin, Eric K; Soles, Christopher L; Goldfarb, Dario L; Trinque, Brian C; Burns, Sean D; Jones, Ronald L; Lenhart, Joseph L; Angelopoulos, Marie; Willson, C Grant; Satija, Sushil K; Wu, Wen-Li

    2002-07-19

    The continuing drive by the semiconductor industry to fabricate smaller structures using photolithography will soon require dimensional control at length scales comparable to the size of the polymeric molecules in the materials used to pattern them. The current technology, chemically amplified photoresists, uses a complex reaction-diffusion process to delineate patterned areas with high spatial resolution. However, nanometer-level control of this critical process is limited by the lack of direct measurements of the reaction front. We demonstrate the use of x-ray and neutron reflectometry as a general method to measure the spatial evolution of the reaction-diffusion process with nanometer resolution. Measuring compositional profiles, provided by deuterium-labeled reactant groups for neutron scattering contrast, we show that the reaction front within the material is broad rather than sharply defined and the compositional profile is altered during development. Measuring the density profile, we directly correlate the developed film structure with that of the reaction front.

  14. Enzyme reactions and their time resolved measurements

    International Nuclear Information System (INIS)

    Hajdu, Janos

    1990-01-01

    This paper discusses experimental strategies in data collection with the Laue method and summarises recent results using synchrotron radiation. Then, an assessment is made of the progress towards time resolved studies with protein crystals and the problems that remain. The paper consists of three parts which respectively describe some aspects of Laue diffraction, recent examples of structural results from Laue diffraction, and kinetic Laue crystallography. In the first part, characteristics of Laue diffraction is discussed first, focusing on the harmonics problems, spatials problem, wavelength normalization, low resolution hole, data completeness, and uneven coverage of reciprocal space. Then, capture of the symmetry unique reflection set is discussed focusing on the effect of wavelength range on the number of reciprocal lattice points occupying diffracting positions, effect of crystal to film distance and the film area and shape on the number of reflections captured, and effect of crystal symmetry on the number of unique reflections within the number of reflections captured. The second part addresses the determination of the structure of turkey egg white lysozyme, and calcium binding in tomato bushy stunt virus. The third part describes the initiation of reactions in enzyme crystals, picosecond Laue diffraction at high energy storage rings, and detectors. (N.K.)

  15. Measurement and analysis of $\\alpha$ particle induced reactions on yttrium

    CERN Document Server

    Singh, N L; Chintalapudi, S N

    2000-01-01

    Excitation functions for /sup 89/Y[( alpha ,3n); ( alpha ,4n); ( alpha , p3n); ( alpha , alpha n); ( alpha , alpha 2n)] reactions were measured up to 50 MeV using stacked foil activation technique and HPGe gamma ray spectroscopy method. The experimental data were compared with calculations considering equilibrium as well as preequilibrium reactions according to the hybrid model of Blann (ALICE/90). For ( alpha , xnyp) type of reactions, the precompound contributions are described by the model. There seems to be indications of direct inelastic scattering effects in ( alpha , alpha xn) type of reactions. To the best of our knowledge, the excitation functions for ( alpha ,4n), ( alpha , p3n), ( alpha , alpha n) and ( alpha , alpha 2n) reactions were measured for the first time. (23 refs).

  16. Measurement and analysis of alpha particle induced reactions on yttrium

    Energy Technology Data Exchange (ETDEWEB)

    Singh, N.L.; Gadkari, M.S. [Baroda Univ. (India). Dept. of Physics; Chintalapudi, S.N. [IUC-DAEF Calcutta Centre, Calcutta (India)

    2000-05-01

    Excitation functions for {sup 89}Y[({alpha},3n);({alpha},4n);({alpha},p3n);({alpha},{alpha}n);({alpha},{alpha}2n)] reactions were measured up to 50 MeV using stacked foil activation technique and HPGe gamma ray spectroscopy method. The experimental data were compared with calculations considering equilibrium as well as preequilibrium reactions according to the hybrid model of Blann (ALICE/90). For ({alpha},xnyp) type of reactions, the precompound contributions are described by the model. There seems to be indications of direct inelastic scattering effects in ({alpha},{alpha}xn) type of reactions. To the best of our knowledge, the excitation functions for ({alpha},4n), ({alpha},p3n), ({alpha},{alpha}n) and ({alpha},{alpha}2n) reactions were measured for the first time. (orig.)

  17. A method for measuring light ion reaction cross-sections

    International Nuclear Information System (INIS)

    Carlson, R.F.; Ingemarsson, A.; Lantz, M.; Arendse, G.J.; Auce, A.; Cox, A.J.; Foertsch, S.V.; Jacobs, N.M.; Johansson, R.; Nyberg, J.; Peavy, J.; Renberg, P.-U.; Sundberg, O.; Stander, J.A.; Steyn, G.F.; Tibell, G.; Zorro, R.

    2005-01-01

    An experimental procedure for measuring reaction cross-sections of light ions in the energy range 20-50 MeV/nucleon, using a modified attenuation technique, is described. The detection method incorporates a forward detector that simultaneously measures the reaction cross-sections for five different sizes of the solid angle in steps from 99.1% to 99.8% of the total solid angle. The final reaction cross-section values are obtained by extrapolation to the full solid angle

  18. Ionospheric measurements during the CRISTA/MAHRSI campaign: their implications and comparison with previous campaigns

    Directory of Open Access Journals (Sweden)

    J. Laštovicka

    Full Text Available The CRISTA/MAHRSI experiment on board a space shuttle was accompanied by a broad campaign of rocket, balloon and ground-based measurements. Supporting lower ionospheric ground-based measurements were run in Europe and Eastern Asia between 1 October-30 November, 1994. Results of comparisons with long ionospheric data series together with short-term comparisons inside the interval October-November, 1994, showed that the upper middle atmosphere 
    (h = 80-100 km at middle latitudes of the Northern Hemisphere in the interval of the CRISTA/MAHRSI experiment (4-12 November, 1994 was very close to its expected climatological state. In other words, the average results of the experiment can be used as climatological data, at least for the given area/altitudes. The role of solar/geomagnetic and "meteorological" control of the lower ionosphere is investigated and compared with the results of MAP/WINE, MAC/SINE and DYANA campaigns. The effects of both solar/geomagnetic and global meteorological factors on the lower ionosphere are found to be weak during autumn 1994 compared to those in MAP/WINE and DYANA winters, and they are even slightly weaker than those in MAP/SINE summer. The comparison of the four campaigns suggests the following overall pattern: in winter the lower ionosphere at northern middle latitudes appears to be fairly well "meteorologically" controlled with a very weak solar influence. In summer, solar influence is somewhat stronger and dominates the weak "meteorological" influence, but the overall solar/meteorological control is weaker than in winter. In autumn we find the weakest overall solar/meteorological control, local effects evidently dominate.

    Key words. Ionosphere (ionosphere · atmosphere interactions; mid-latitude ionosphere

  19. Measurement of reaction rates for different neutron induced reactions in27Al.

    Science.gov (United States)

    Schulc, Martin; Baroň, Petr; Novák, Evžen; Jánský, Bohumil; Harutyunyan, Davit

    2016-12-01

    The presented paper aims to compare various measured neutron induced reaction rates in Aluminium with computed ones in different nuclear data libraries. A 252 Cf neutron source with emission rate of 9.53E8 n/s was used. Reactions involved in the study were 27 Al(n,g), 27 Al (n,p) and 27 Al (n,α). Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Criteria of reaction identification and selection of badly measured events

    International Nuclear Information System (INIS)

    Linetskij, A.R.; Lyubarskij, G.Ya.; Sagalovich, N.E.

    1979-01-01

    Basing on photoemulsion methods of studying channels of multiparticle nuclear reactions the metrological characteristics of a physical technique are described in the process of its development. To increase the accuracy of reaction identification the technique for picture measuring has been complicated by introducing calibration measurements of tracks of stopped in the emulsion primary α-particles. Callibration measurements have support assumptions on energy oscillations of the primary beam and made possible the employment of actual values of this energy instead of rated one during mathematical processing. By using simulation reactions the effect of errors in determining the contraction ratio has been estimated. It has been found that rather a small error in determining the contraction (+-20%) results in additional casting-out 8-15% of measured events

  1. [Measurements of observables of pion-nucleon reactions]. Progress report

    International Nuclear Information System (INIS)

    Sadler, M.E.

    1985-01-01

    This document reports the progress of the research of pion reactions. These include (1) a study to measure observables in the pion-nucleon system in the momentum interval 400 to 700 MeV/c, (2) differential cross section measurements at low energy for pion-nucleon charge exchange, and (3) elastic and inelastic scattering of π +- on 3 H and 3 He. Individual experiments will be indexed separately

  2. Measuring one nucleon transfer reaction 24Mg( p, d)23Mg for astrophysical reaction rates

    Science.gov (United States)

    Lee, E. J.; Chae, K. Y.

    2017-12-01

    The level structure of a radionuclide 23Mg has been studied by using the 24Mg( p, d)23Mg one nucleon transfer reaction measurement for the astrophysical 19Ne(α, γ)23Mg reaction rate. A 41 MeV proton beam was produced and accelerated at the 25 MV tandem accelerator of the Holifield Radioactive Ion Beam Facility of the Oak Ridge National Laboratory in the United States. The beam particles impinged on an isotopically-enriched 24Mg solid target. Angular distributions of recoiling deuterons were extracted by using a large area silicon strip detector array. By comparing the experimentally-obtained angular distributions with zero range distorted wave Born approximation calculations, spins and parities of three energy levels of 23Mg could be constrained for the first time, which is very important information needed to understand the 19Ne(α, γ)23Mg reaction rate.

  3. 17F breakup reactions: a touchstone for indirect measurements

    International Nuclear Information System (INIS)

    De Napoli, M.; Raciti, G.; Sfienti, C.; Capel, P.; Baye, D.; Descouvemont, P.; Sparenberg, J.-M.; Giacoppo, F.; Rapisarda, E.; Cardella, G.; Mazzocchi, C.

    2011-01-01

    An exclusive study of 17 F breakup reactions has been performed at the FRIBs facility of the Laboratori Nazionali del Sud in Catania (Italy). The experiment has been performed with the aim of testing the accuracy of the Coulomb-breakup indirect technique used to infer radiative-capture cross sections at low energies. This technique has been used in the 7 Be(p,γ) 8 B case, but has never been tested. By measuring the breakup of 17 F into 16 O+p, and comparing the inferred cross section for 16 O(p,γ) 17 F to direct precise measurements, the influence of E2 transitions and higher-order effects, that are predicted to be significant in Coulomb-breakup reactions, can be evaluated. The first results and preliminary model comparison are reported.

  4. Measurements of precipitin reactions by difference turbidimetry: a new method.

    Science.gov (United States)

    Jacobsen, C; Steensgaard, J

    1979-01-01

    A new method for the measurement of precipitin and flocculation reactions between antibodies and antigens has been developed. The technique, called difference turbidimetry, involves the use of tandem cuvettes providing the opportunity of using separated and unmixed antigen and antibody as blank solutions for spectrophotometric readings in the ultraviolet wavelength range. By use of this technique genuine difference turbidity spectra have been recorded for the reaction between human serum albumin and rabbit-anti-human serum albumin IgG. It was found that difference turbidimetry at low wavelengths (e.g. 280 nm) allows the construction of precipitin curves with a very clearly expressed zoning phenomenon at a sensitivity which in terms of antigen and antibody concentrations is more than twice the sensitivity of conventional procedures. It is of special interest that the zone of equivalence differs when the same reaction between an antigen and its antibody is measured by difference turbidimetry, by absorbance of washed and redissolved precipitate, and by amount of precipitated antigen. PMID:437833

  5. Direct measurements of reactions for p-process nucleosynthesis

    International Nuclear Information System (INIS)

    Reifarth, R.; Goebel, K.; Hinrichs, O.; Mei, B.; Meusel, O.; Plag, R.; Rastrepina, G.; Sonnabend, K.; Weigand, M.

    2013-01-01

    Full text: Almost all of the heavy elements are produced via neutron-induced processes in a multitude of stellar production sites. The remaining minor part is produced via - and proton-induced reactions. The predictive power of the underlying stellar models is currently limited because they contain poorly constrained physics components such as convection, rotation or magnetic fields. An important tool determine such components is the comparison of observed with modeled abundance distributions based on improved nuclear physics input. The FRANZ facility at the Goethe University Frankfurt, which is currently under construction will provide unprecedented neutron fluxes and proton currents available for nuclear astrophysics. It will be possible to investigate proton- and neutron-induced reactions important for p-process nucleosynthesis. At the GSI close to Darmstadt radioactive isotopes can be investigated in inverse kinematics. This allows experiments such as proton-induced cross section measurements using a heavy ion storage ring or γ-induced reaction measurements using the Coulomb dissociation method. The future FAIR facility will allow similar experiments on short-lived nuclei, since orders of magnitude higher radioactive ion beams will be possible.

  6. Detection of Enterococcus faecalis and Candida albicans in previously root-filled teeth in a population of Gujarat with polymerase chain reaction

    Directory of Open Access Journals (Sweden)

    Bruhvi Poptani

    2013-01-01

    Full Text Available Background: Micro-organisms are the primary causative agents of endodontic infections. Phenotype based procedures for bacterial identification has certain drawbacks especially, when investigating the microbiota of root-filled teeth. Thus, more sensitive methods like Polymerase chain reaction (PCR can provide results that are more accurate and reliable for the microbial prevalence in the root filled teeth. Aim: In this study, we have investigated twenty symptomatic root-filled teeth with chronic apical periodontitis for the prevalence of Enterococcus faecalis and Candida albicans in the root filled teeth associated with symptomatic cases with or without periradicular lesions. Materials and Methods: Microbiological samples were taken from the canals immediately after removal of previous gutta percha cones using aseptic techniques. After removal of root canal filling, samples were obtained with paper points placed in the canal. Paper points were transferred to a cryotube containing "Tris EDTA" buffer and immediately frozen at −20°C. Results: By PCR amplification of the samples using taxon specific primers, E. faecalis was found to be prevalent species, detected in 65% of the cases and C. albicans was detected in 35% of cases. Conclusion: The results of the study shows that geographical influence and dietary factors might have some role to play in the prevalence of the species like C. albicans and presence of E. faecalis confirming the assertion of previous culture-dependent and independent approaches for the microbiological survey of root filled teeth.

  7. Measuring cognitive, affective, and behavioral components of homophobic reaction.

    Science.gov (United States)

    Van de Ven, P; Bornholt, L; Bailey, M

    1996-04-01

    Comprehensive, reliable, and valid measurement of prejudicial attitudes and behaviors toward lesbians and gay males has been identified as a priority. A sample of undergraduate (N = 97) and high school students (N = 40) completed three reliable measures of cognitive (Modified Attitudes Toward Homosexuality Scale), affective (Affective Reactions to Homosexuality Scale), and behavioral (Homophobic Behavior of Students Scale) reactions to homosexuals. Undergraduate students' responses confirmed the three-factor structure (homophobic guilt, homophobic anger, delight) of affects in this domain, and supported the concurrent validity of the behavioral measure. Predictive validity of the behavioral scale was demonstrated by findings of the high school study which showed that students subsequently acted in accordance with their responses to this paper-and-pencil test. LISREL confirmatory factor analysis of the overarching model indicated that a tripartite (cognition-affect-behavior) measurement strategy was appropriate. This strategy may be used in future research to provide comprehensive indication of which educational interventions make a difference in improving understanding and acceptance of homosexuality.

  8. MEASUREMENT OF REACTION TIME IN QWAN KI DO

    Directory of Open Access Journals (Sweden)

    A Cojocariu

    2011-06-01

    Full Text Available The aim of this study is to identify the simple and choice reaction time to visual stimuli, for the upper limbs, in beginner and advanced practitioners of the Qwan Ki Do martial art, and also to identify differences between the various populations of the study. We used a total of 73 male subjects, aged between 18 and 33, taken from three groups. The first group (control was composed of 47 students in physical education and sport (group 1, the second group was composed of 18 beginner (less than 1 year athletes practising Qwan Ki Do (group 2, and the third group was composed of 8 athletes practising Qwan Ki Do with great experience (group 3. As a result of the measurements, we concluded that the simple reaction time has, in general, similar values in all the research groups (239.6±7.4 in group 1, 221.9±5.5 in group 2 and 207±6.6 in group 3 – data are expressed as mean ± standard error mean. Also, the choice reaction time in group 3 (376±4.7 ms for the dominant hand and 376±5.4 ms for the non-dominant hand is significantly lower (p 0.05, are probably due to the specific training in Qwan Ki Do, based on equal involvement in effort of both body halves.

  9. Lifetime measurement of 75Br with inverse kinematic reaction

    International Nuclear Information System (INIS)

    Negi, Dinesh; Kumar, V.; Muralithar, S.; Kumar, R.; Singh, R.P.; Pancholi, S.C.; Bhowmik, R.K.; Trivedi, T.; Babu, S.A.; Ranjeet; Kumar, V.; Bhati, A.K.; Singh, P.P.

    2007-01-01

    75 Br is an isotone of 74 Se and 76 Kr. Both of them are known for showing shape coexistence with different shape in ground state. It is a question whether odd particle, in this case a proton in 75 Br, stabilizes one of the shape or feel the shape co-existence of the core. Transitional probabilities and magnetic moment of the states will help in answering these questions. Thus it motivates us to re-measure the lifetime of excited states of ground state band of 75 Br using inverse reaction and to provide necessary information about the feeding time of these states which can then be used in magnetic moment measurement

  10. Does an instrumented treadmill correctly measure the ground reaction forces?

    Directory of Open Access Journals (Sweden)

    Patrick A. Willems

    2013-11-01

    Since the 1990s, treadmills have been equipped with multi-axis force transducers to measure the three components of the ground reaction forces during walking and running. These measurements are correctly performed if the whole treadmill (including the motor is mounted on the transducers. In this case, the acceleration of the treadmill centre of mass relative to the reference frame of the laboratory is nil. The external forces exerted on one side of the treadmill are thus equal in magnitude and opposite in direction to the external forces exerted on the other side. However, uncertainty exists about the accuracy of these measures: due to friction between the belt and the tread-surface, due to the motor pulling the belt, some believe that it is not possible to correctly measure the horizontal components of the forces exerted by the feet on the belt. Here, we propose a simple model of an instrumented treadmill and we demonstrate (1 that the forces exerted by the subject moving on the upper part of the treadmill are accurately transmitted to the transducers placed under it and (2 that all internal forces – including friction – between the parts of the treadmill are cancelling each other.

  11. Measurement of charmed particle production in hadronic reactions

    CERN Multimedia

    2002-01-01

    The aim of the experiment is to measure the production cross-section for charmed particles in hadronic reactions, study their production mechanism, and search for excited charmed hadrons.\\\\ \\\\ Charmed Mesons and Baryons will be measured in $\\pi$ and $p$ interactions on Beryllium between 100 and 200 GeV/c. The trigger will be on an electron from the leptonic decay of one charmed particle by signals from the Cerenkov counter (Ce), the electron trigger calorimeter (eCal), scintillation counters, and proportional wire chambers. The accompanying charmed particle will be measured via its hadronic decay in a two-stage magnetic spectrometer with drift chambers (arms 2, 3a, 3b, 3c), two large-area multicell Cerenkov counters (C2, C3) and a large-area shower counter ($\\gamma$-CAL). The particles which can be measured and identified include $\\gamma, e, \\pi^{\\pm}, \\pi^{0}, K^{\\pm}, p, \\bar{p}$ so that a large number of hadronic decay modes of charmed particles can be studied. \\\\ \\\\ A silicon counter telescope with 5 $\\m...

  12. The reliability of the Associate Platinum digital foot scanner in measuring previously developed footprint characteristics: a technical note.

    Science.gov (United States)

    Papuga, M Owen; Burke, Jeanmarie R

    2011-02-01

    An ink pad and paper, pressure-sensitive platforms, and photography have previously been used to collect footprint data used in clinical assessment. Digital scanners have been widely used more recently to collect such data. The purpose of this study was to evaluate the intra- and interrater reliability of a flatbed digital image scanning technology to capture footprint data. This study used a repeated-measures design on 32 (16 male 16 female) healthy subjects. The following measured indices of footprint were recorded from 2-dimensional images of the plantar surface of the foot recorded with an Associate Platinum (Foot Levelers Inc, Roanoke, VA) digital foot scanner: Staheli index, Chippaux-Smirak index, arch angle, and arch index. Intraclass correlation coefficient (ICC) values were calculated to evaluate intrarater, interday, and interclinician reliability. The ICC values for intrarater reliability were greater than or equal to .817, indicating an excellent level of reproducibility in assessing the collected images. Analyses of variance revealed that there were no significant differences between raters for each index (P > .05). The ICC values also indicated excellent reliability (.881-.971) between days and clinicians in all but one of the indices of footprint, arch angle (.689), with good reliability between clinicians. The full-factorial analysis of variance model did not reveal any interaction effects (P > .05), which indicated that indices of footprint were not changing across days and clinicians. Scanning technology used in this study demonstrated good intra- and interrater reliability measurements of footprint indices, as demonstrated by high ICC values. Copyright © 2011 National University of Health Sciences. Published by Mosby, Inc. All rights reserved.

  13. Measuring the complex behavior of the SO2 oxidation reaction

    Directory of Open Access Journals (Sweden)

    Muhammad Shahzad

    2015-09-01

    Full Text Available The two step reversible chemical reaction involving five chemical species is investigated. The quasi equilibrium manifold (QEM and spectral quasi equilibrium manifold (SQEM are used for initial approximation to simplify the mechanisms, which we want to utilize in order to investigate the behavior of the desired species. They show a meaningful picture, but for maximum clarity, the investigation method of invariant grid (MIG is employed. These methods simplify the complex chemical kinetics and deduce low dimensional manifold (LDM from the high dimensional mechanism. The coverage of the species near equilibrium point is investigated and then we shall discuss moving along the equilibrium of ODEs. The steady state behavior is observed and the Lyapunov function is utilized to study the stability of ODEs. Graphical results are used to describe the physical aspects of measurements.

  14. The oxygen evolution reaction on cobalt Part I. Reaction order experiments and impedance measurements

    NARCIS (Netherlands)

    Kobussen, A.G.C.; Willems, H.; Wit, J.H.W. de; Broers, G.H.J.

    1984-01-01

    It was found that the oxygen evolution reaction on cobalt in concentrated KOH solutions can be described differently for low and high overpotentials. In the overpotential range from 150 to 280 mV, the reaction has a Tafel slope of approximately 40 mV and a reaction order with respect to the KOH

  15. Disturbances in reaction wheels; from measurement to modelling

    NARCIS (Netherlands)

    Le, M.P.; Ellenbroek, Marcellinus Hermannus Maria; Seiler, R; van Put, P.; Cottaar, E.J.E.

    2014-01-01

    Disturbances in reaction wheels have been long a crucial aspect for many scientific observation missions. An accurate and reliable disturbance model to understand and evaluate the influence of reaction wheel disturbances to the spacecraft is critically needed. Several reaction wheel disturbance

  16. Measurements and calculations of 10B(n,He) reaction rates in a control rod in ZPPR

    International Nuclear Information System (INIS)

    Brumbach, S.B.; Collins, P.J.; Grasseschi, G.L.; Oliver, B.M.

    1986-01-01

    The helium accumulation fluence monitor (HAFM) technique has been used to measure the 10 B(n,He) reaction rate within B 4 C pellets in a control rod in ZPPR. Knowledge of this reaction rate is important to control rod design studies because helium production leads to control rod swelling, buildup of gas pressure and a reduction in thermal conductivity which can limit the lifetime of a control rod. We believe these to be the first measurements of boron capture within boron pins in a fast reactor spectrum. Previously reported measurements used 235 U foils to measure fission rates in a control rod, and to infer boron capture rates

  17. Neutron-induced reaction cross-section measurements using a ...

    Indian Academy of Sciences (India)

    The experimental setup of Louvain-la-Neuve (UCL-Belgium) used to perform lightcharged particle production experiment in fast neutron-induced reactions is presented. A short description of the neutron modular detector DEMON is also given. DEMON is a detector array for neutrons emitted in heavy ion induced reactions at ...

  18. Measurement of proton capture reactions in the hot cycles: an evaluation of experimental methods

    Energy Technology Data Exchange (ETDEWEB)

    Leleux, P. [Inst. de Physique Nucleaire, Univ. Catholique de Louvain, Louvain-la-Neuve (Belgium)

    1998-06-01

    In the hot cycles, most of the proton capture reactions involve radioactive nuclei in the entrance and exit channels. This paper evaluates the specific methods that were designed to measure such reactions. (orig.)

  19. Online Measurement of Oxygen-Dependent Enzyme Reaction Kinetics

    DEFF Research Database (Denmark)

    Meissner, Murray Peter; Nordblad, Mathias; Woodley, John M

    2018-01-01

    As the application of biocatalysis to complement conventional chemical and catalytic approaches continues to expand, an increasing number of reactions involve poorly-water soluble substrates. At required industrial concentrations necessary for industrial implementation, this frequently leads to h...

  20. Tests on measuring astrophysical S-factors with transfer reactions

    CERN Document Server

    Crespo, R

    2002-01-01

    We propose a general method to test the uniqueness property of the Asymptotic Normalization Constant, ANC. We apply this method for the case of the vertex sup 1 sup 0 B -> sup 9 Be+p using a set of different proton-transfer reactions at different energies. Given the limited sets of data for peripheral transfer reactions, we underline the present difficulties in extracting astrophysical S-factors and point out the inadequacy of some of the available data. Finally, we make some suggestions for future experiments in order to make this test conclusive.

  1. Neutron detector for fusion reaction-rate measurements

    International Nuclear Information System (INIS)

    Lerche, R.A.; Phillion, D.W.; Tietbohl, G.L.

    1993-01-01

    We have developed a fast, sensitive neutron detector for recording the fusion reaction-rate history of inertial-confinement fusion (ICF) experiments. The detector is based on the fast rise-time of a commercial plastic scintillator (BC-422) and has a response 7 neutrons

  2. Neutron-induced reaction cross-section measurements using a ...

    Indian Academy of Sciences (India)

    Abstract. The experimental setup of Louvain-la-Neuve (UCL-Belgium) used to perform light- charged particle production experiment in fast neutron-induced reactions is presented. A short de- scription of the neutron modular detector DEMON is also given. DEMON is a detector array for neutrons emitted in heavy ion induced ...

  3. How the risky features of previous selection affect subsequent decision-making: Evidence from behavioral and fMRI measures

    Directory of Open Access Journals (Sweden)

    Guangheng eDong

    2015-10-01

    Full Text Available Human decision making is rarely conducted in temporal isolation. It is often biased and affected by environmental variables, particularly prior selections. In this study, we used a task that simulates a real gambling process to explore the effect of the risky features of a previous selection on subsequent decision making. Compared with decision making after an advantageous risk-taking situation (Risk_Adv, that after a disadvantageous risk-taking situation (Risk_Disadv is associated with a longer response time (RT, the time spent in making decisions and higher brain activations in the caudate and the dorsolateral prefrontal cortex. Compared with decisions after Risk_Adv, those after Risk_Disadv in loss trials are associated with higher brain activations in the left superior temporal gyrus and the precuneus. Brain activity and relevant RTs significantly correlated. Overall, people who experience disadvantageous risk-taking selections tend to focus on current decision making and engage cognitive endeavors in value evaluation and in the regulation of their risk-taking behaviors during decision making.

  4. How the risky features of previous selection affect subsequent decision-making: evidence from behavioral and fMRI measures.

    Science.gov (United States)

    Dong, Guangheng; Zhang, Yifen; Xu, Jiaojing; Lin, Xiao; Du, Xiaoxia

    2015-01-01

    Human decision making is rarely conducted in temporal isolation. It is often biased and affected by environmental variables, particularly prior selections. In this study, we used a task that simulates a real gambling process to explore the effect of the risky features of a previous selection on subsequent decision making. Compared with decision making after an advantageous risk-taking situation (Risk_Adv), that after a disadvantageous risk-taking situation (Risk_Disadv) is associated with a longer response time (RT, the time spent in making decisions) and higher brain activations in the caudate and the dorsolateral prefrontal cortex (DLPFC). Compared with decisions after Risk_Adv, those after Risk_Disadv in loss trials are associated with higher brain activations in the left superior temporal gyrus (STG) and the precuneus. Brain activity and relevant RTs significantly correlated. Overall, people who experience disadvantageous risk-taking selections tend to focus on current decision making and engage cognitive endeavors in value evaluation and in the regulation of their risk-taking behaviors during decision making.

  5. Utility of spectral measurements of secondary reaction products

    International Nuclear Information System (INIS)

    Heidbrink, W.E.

    1986-02-01

    The spectra of 15 MeV protons and 14 MeV neutrons produced in the burnup of 0.8 MeV 3 He ions and 1 MeV tritons through the d( 3 He,p)α and d(t,n)α fusion reactions contain information on the velocity distributions of the energetic 3 He ions and tritons. 11 refs., 2 figs

  6. Exclusive measurements of nuclear breakup reactions of 17Ne

    Directory of Open Access Journals (Sweden)

    Wamers F.

    2014-03-01

    Full Text Available We have studied one-proton-removal reactions of about 500MeV/u 17Ne beams on a carbon target at the R3B/LAND setup at GSI by detecting beam-like 15O-p and determining their relative-energy distribution. We exclusively selected the removal of a 17Ne halo proton, and the Glauber-model analysis of the 16F momentum distribution resulted in an s2 contribution in the 17Ne ground state of about 40%.

  7. Upper atmosphere research: Reaction rate and optical measurements

    Science.gov (United States)

    Stief, L. J.; Allen, J. E., Jr.; Nava, D. F.; Payne, W. A., Jr.

    1990-01-01

    The objective is to provide photochemical, kinetic, and spectroscopic information necessary for photochemical models of the Earth's upper atmosphere and to examine reactions or reactants not presently in the models to either confirm the correctness of their exclusion or provide evidence to justify future inclusion in the models. New initiatives are being taken in technique development (many of them laser based) and in the application of established techniques to address gaps in the photochemical/kinetic data base, as well as to provide increasingly reliable information.

  8. Hydrogen release from irradiated elastomers measured by Nuclear Reaction Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Jagielski, J., E-mail: jacek.jagielski@itme.edu.pl [Institute for Electronic Materials Technology, Wolczynska 133, 01-926 Warszawa (Poland); National Centre for Nuclear Research, A. Soltana 7, 05-400 Swierk/Otwock (Poland); Ostaszewska, U. [Institute for Engineering of Polymer Materials & Dyes, Division of Elastomers & Rubber Technology, Harcerska 30, 05-820 Piastow (Poland); Bielinski, D.M. [Technical University of Lodz, Institute of Polymer & Dye Technology, Stefanowskiego 12/16, 90-924 Lodz (Poland); Grambole, D. [Institute of Ion Beam Physics and Materials Research, Helmholtz Zentrum Dresden Rossendorf, PO Box 51 01 19, D-01314 Dresden (Germany); Romaniec, M.; Jozwik, I.; Kozinski, R. [Institute for Electronic Materials Technology, Wolczynska 133, 01-926 Warszawa (Poland); Kosinska, A. [National Centre for Nuclear Research, A. Soltana 7, 05-400 Swierk/Otwock (Poland)

    2016-03-15

    Ion irradiation appears as an interesting method of modification of elastomers, especially friction and wear properties. Main structural effect caused by heavy ions is a massive loss of hydrogen from the surface layer leading to its smoothening and shrinking. The paper presents the results of hydrogen release from various elastomers upon irradiation with H{sup +}, He{sup +} and Ar{sup +} studied by using Nuclear Reaction Analysis (NRA) method. The analysis of the experimental data indicates that the hydrogen release is controlled by inelastic collisions between ions and target electrons. The last part of the study was focused on preliminary analysis of mechanical properties of irradiated rubbers.

  9. Measurement of the neutron-neutron scattering length using the π-d capture reaction

    International Nuclear Information System (INIS)

    Chen, Q.; Howell, C. R.; Kiser, M. R.; Roper, C. D.; Salinas, F.; Setze, H. R.; Tornow, W.; Walter, R. L.; Carman, T. S.; Gibbs, W. R.; Gibson, B. F.; Morris, C.; Obst, A.; Sterbenz, S.; Whitton, M.; Hussein, A.; Mertens, G.; Moore, C. F.; Whiteley, C. R.; Pasyuk, E.

    2008-01-01

    We have determined a value for the 1 S 0 neutron-neutron scattering length (a nn ) from high-precision measurements of time-of-flight spectra of neutrons from the 2 H(π - ,n γ) n capture reaction. The measurements were done at the Los Alamos Meson Physics Facility by the E1286 Collaboration. The high spatial resolution of our γ-ray detector enabled us to make a detailed assessment of the systematic uncertainties in our techniques. The value obtained in the present work is a nn =-18.63±0.10 (statistical) ± 0.44 (systematic) ± 0.30 (theoretical) fm. This result is consistent with previous determinations of a nn from the π - d capture reaction. We found that the analysis of the data with calculations that use a relativistic phase-space factor gives a more negative value for a nn by 0.33 fm over the analysis done using a nonrelativistic phase-space factor. Combining the present result with the previous ones from π - d capture gives a nn =-18.63±0.27(expt)±0.30 fm (theory). For the first time the combined statistical and systematic experimental uncertainty in a nn is smaller than the theoretical uncertainty and comparable to the uncertainty in the proton-proton 1 S 0 scattering length (a pp ). This average value of a nn when corrected for the magnetic-moment interaction of the two neutrons becomes -18.9 ± 0.4 fm, which is 1.6 ± 0.5 fm different from the recommended value of a pp , thereby confirming charge symmetry breaking at the 1% confidence level

  10. Carbon burning in stars - Prospects for underground measurements of the 12C+12C fusion reactions

    International Nuclear Information System (INIS)

    Strieder, Frank

    2010-01-01

    The 12 C+ 12 C fusion reactions are together with the reaction 12 C(a,γ) 16 O the most important nuclear processes in the late stellar evolution. These fusion reactions play a key role in the understanding of various types of astrophysical objects. Thus, a measurement of the 12 C+ 12 C cross section at very low energies can serve as flagship experiment for a future underground accelerator laboratory. It is hoped that an appropriate facility for such a study will be created in the near future somewhere in the world. The prospects for the measurement of the carbon fusion reactions will be discussed in the present work.

  11. Vibration measurement and simulation analysis on a reinforced concrete structure with alkali-silica reaction

    International Nuclear Information System (INIS)

    Murazumi, Y.; Watanabe, Y.; Hosokawa, T.; Takakazu Ishi; Katsuki Takiguchi; Masuda, Y.

    2005-01-01

    This paper discusses vibration test and measurement of elastic wave velocity, and simulation analyses on the vibration test concerning the turbine generator foundation of the Ikata nuclear power station unit no. 1, Japan, where expansion produced by alkali-silica reaction (ASR) has been observed. Under the vibration test, vertical excitation test of the beams and microtremor measurement were conducted to estimate Eigen frequency/mode and examine time-dependent change of the stiffness of the foundation by comparing with the results in the previous test done in the same way. Elastic wave velocity was measured to observe the difference of material properties among places of the foundation. Simulation analyses on the vibration test were done to estimate the elastic modulus of the members where ASR is induced. We obtained the following conclusions: (1) The time-dependant change of the stiffness and ASR have very low effect on the entire structure of the unit no.1 (2) It is estimated that ASR has not developed since 1989 because the reduction of the Eigen frequencies of the foundation is small. (3) The reduction of the elastic modulus of the table-deck stands out by comparison of the elastic modulus of the unit no.1 and no.2 from the measurement of elastic wave velocity. (4) The elastic modulus ratio of the members with ASR to the members without ASR is estimated from 0.5 to 0.6 by the simulation analyses. (authors)

  12. Reactions of airway epithelial cells to birch pollen grains previously exposed to in situ atmospheric Pb concentrations: a preliminary assay of allergenicity.

    Science.gov (United States)

    Bellanger, Anne-Pauline; Bosch-Cano, Floriane; Millon, Laurence; Ruffaldi, Pascale; Franchi, Marielle; Bernard, Nadine

    2012-12-01

    A growing body of evidence suggests that interactions between pollen grains and environmental pollutants, especially air pollutants, could be of critical importance with regard to the increase in allergic responses observed in the past decades. Using birch pollen grains (BPG), a major allergy source in European countries, and lead (Pb), a highly toxic metal trace element (MTE) present in urban areas, the immune response of human epithelial cells exposed to BPG or to Pb-associated BPG was compared. The cellular response after exposure either to BPG, BPG exposed to 30 mg/L of Pb (BPG-30), or BPG exposed to 60 mg/L of Pb (BPG-60) was evaluated after two time lapses (2 and 6 h) by measuring mRNA levels of four mediators, including two inflammatory (interleukin-8 and interleukin-6) and two allergic (interleukin-5 [IL-5] and interleukin-13) cytokines. After 2 h of exposure, significant upregulation of the IL-5 gene was observed after exposure to BPG-60 in comparison with exposure to BPG and BPG-30 (N (IL-5) = 1.9, Mann-Whitney test, p = 0.003). After 6 h of exposure, significant upregulation of the IL-5 gene was observed after exposure to BPG-30 with N (IL-5) = 1.8 and to BPG-60 with N (IL-5) = 2.3 (Mann-Whitney test, p = 0.0029) in comparison with exposure to BPG. This first attempt to investigate the influence of pollution by MTE on pollen grain showed a dose-time-dependent increase in IL-5 gene expression after exposure to BPG combined to Pb.

  13. Thin wall vacuum reaction chamber for neutron measurement

    International Nuclear Information System (INIS)

    Banerjee, K.; Meena, J.K.; Bhattacharya, Sumantra; Bhattacharya, S.; Bhattacharya, C.; Roy, P.; Saha, A.K.; Ghosh, T.K.; Kundu, S.; Rana, T.K.; Mukherjee, G.; Pandey, R.; Sahoo, J.K.; Saha Mondal, R.; Yadav, R.C.; Chatterjee, S.

    2013-01-01

    A thin wall (3 mm) stainless steel vacuum reaction chamber has been designed, fabricated and installed in the K500 superconducting beam hall at VECC for the in-beam experiment. The chamber is spherical in shape, with inner diameter 1010 mm, having three independent sections. The middle segment is fixed to the beam line, whereas the two hemispherical sections are removable type with the help of hydraulic trolleys. This specific design facilitates almost 360 degree access of the chamber for setting up an experiment. The typical vacuum ∼ 4 x 10 -7 mbar is achieved by two 550 lit/sec air cooled turbo molecular pumps backed by two 35 m 3 /hr scroll pumps in ∼ 8 hours. PLC based control system has been developed for the operation of pumps. 12 rings are fabricated to mount detectors, each having 440 mm radius and separated by 30° from each other in polar angle. These rings are supported inside the chamber by two flanges placed along the beam line. These rings are properly calibrated in polar and azimuthal angles with respect to the centre of the chamber. (author)

  14. Recoil range distribution measurement in 20Ne + 181Ta reaction

    International Nuclear Information System (INIS)

    Tripathi, R.; Sudarshan, K.; Goswami, A.; Guin, R.; Reddy, A.V.R.

    2005-01-01

    In order to investigate linear momentum transfer in various transfer channels in 20 Ne + 181 Ta, recoil range distribution measurements have been carried out at E lab = 180 MeV, populating significant number of l-waves above l crit

  15. Rate constant measurements for the overall reaction of OH + 1-butanol → products from 900 to 1200 K.

    Science.gov (United States)

    Pang, Genny A; Hanson, Ronald K; Golden, David M; Bowman, Craig T

    2012-03-15

    The rate constant for the overall reaction OH + 1-butanol → products was determined in the temperature range 900 to 1200 K from measurements of OH concentration time histories in reflected shock wave experiments of tert-butyl hydroperoxide (TBHP) as a fast source of OH radicals with 1-butanol in excess. Narrow-linewidth laser absorption was employed for the quantitative OH concentration measurement. A detailed kinetic mechanism was constructed that includes updated rate constants for 1-butanol and TBHP kinetics that influence the near-first-order OH concentration decay under the present experimental conditions, and this mechanism was used to facilitate the rate constant determination. The current work improves upon previous experimental studies of the title rate constant by utilizing a rigorously generated kinetic model to describe secondary reactions. Additionally, the current work extends the temperature range of experimental data in the literature for the title reaction under combustion-relevant conditions, presenting the first measurements from 900 to 1000 K. Over the entire temperature range studied, the overall rate constant can be expressed in Arrhenius form as 3.24 × 10(-10) exp(-2505/T [K]) cm(3) molecule(-1) s(-1). The influence of secondary reactions on the overall OH decay rate is discussed, and a detailed uncertainty analysis is performed yielding an overall uncertainty in the measured rate constant of ±20% at 1197 K and ±23% at 925 K. The results are compared with previous experimental and theoretical studies on the rate constant for the title reaction and reasonable agreement is found when the earlier experimental data were reinterpreted.

  16. Estimation and prediction of convection-diffusion-reaction systems from point measurement

    NARCIS (Netherlands)

    Vries, D.

    2008-01-01

    Different procedures with respect to estimation and prediction of systems characterized by convection, diffusion and reactions on the basis of point measurement data, have been studied. Two applications of these convection-diffusion-reaction (CDR) systems have been used as a case study of the

  17. Reaction measurements with the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target

    Science.gov (United States)

    Chipps, K. A.

    2017-09-01

    Explosive stellar environments are sometimes driven by nuclear reactions on short-lived, radioactive nuclei. These reactions often drive the stellar explosion, alter the observable light curves produced, and dictate the final abundances of the isotopes created. Unfortunately, many reaction rates at stellar temperatures cannot be directly measured in the laboratory, due to the physical limitations of ultra-low cross sections and high background rates. An additional complication arises because many of the important reactions involve radioactive nuclei which have lifetimes too short to be made into a target. As such, direct reactions require very intense and pure beams of exotic nuclei. Indirect approaches with both stable and radioactive beams can, however, provide crucial information on the nuclei involved in these astrophysical reactions. A major development toward both direct and indirect studies of nuclear reactions rates is the commissioning of the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) supersonic gas jet target. The JENSA system provides a pure, homogeneous, highly localized, dense, and robust gaseous target for radioactive ion beam studies. Charged-particle reactions measurements made with gas jet targets can be cleaner and display better resolution than with traditional targets. With the availability of pure and localized gas jet targets in combination with developments in exotic radioactive ion beams and next-generation detector systems, the range of reaction studies that are experimentally possible is vastly expanded. Various representative cases will be discussed.

  18. d-3He reaction measurements during fast wave minority heating in PLT

    International Nuclear Information System (INIS)

    Chrien, R.E.; Strachan, J.D.

    1983-01-01

    Time- and energy-resolved d- 3 He fusion reactions have been measured to infer the energy of the d + or He ++ minority ions heated near their cyclotron frequency by the magnetosonic fast wave. The average energy of the reacting 3 He ions during 3 He minority heating is in the range of 100 to 400 keV, as deduced from the magnitude of the reaction rate, its decay time, and the energy spread of the proton reaction products. The observed reaction rate and its scaling with wave power and electron density and temperature are in qualitative agreement with a radial reaction rate model using the minority distribution predicted from quasilinear velocity space diffusion. Oscillations in the reaction rate are observed concurrent with sawtooth and m = 2 MHD activity in the plasma

  19. Design of a fusion reaction-history measurement system with high temporal resolution

    International Nuclear Information System (INIS)

    Peng Xiaoshi; Wang Feng; Liu Shenye; Jiang Xiaohua; Tang Qi

    2010-01-01

    In order to accurately measure the history of fusion reaction for experimental study of inertial confinement fusion, we advance the design of a fusion reaction-history measurement system with high temporal resolution. The diagnostic system is composed of plastic scintillator and nose cone, an optical imaging system and the system of optic streak camera. Analyzing the capability of the system indicated that the instrument measured fusion reaction history at temporal resolution as low as 55ps and 40ps correspond to 2.45MeV DD neutrons and 14.03MeV DT neutrons. The instrument is able to measure the fusion reaction history at yields 1.5 x 10 9 DD neutrons, about 4 x 10 8 DT neutrons are required for a similar quality signal. (authors)

  20. Measurement of the Erc .m .=259 keV resonance in the 14N(p ,γ )15O reaction

    Science.gov (United States)

    Daigle, S.; Kelly, K. J.; Champagne, A. E.; Buckner, M. Q.; Iliadis, C.; Howard, C.

    2016-08-01

    The 14N(p ,γ )15O reaction regulates the power generated by the CN cycle and thus impacts the structure and evolution of every star at some point in its life. The lowest positive-energy resonance in this reaction is located at Erc .m .=259 keV, too high in energy to strongly influence quiescent stellar burning. However, the strength of this resonance is used as a cross-section normalization for lower-energy measurements of this reaction. We report on new measurements of the energy, strength, and γ -ray branching ratios for the 259-keV resonance, using different detection and data-analysis schemes. We have also reevaluated previous results, where possible. Our new recommended strength of ω γ =12.6 (3 ) meV is in agreement with the previous value of 13.1(6) meV, but is more precise and thus provides a more reliable normalization for low-energy (p ,γ ) measurements.

  1. Measurement of (n, xnγ reaction cross sections in W isotopes

    Directory of Open Access Journals (Sweden)

    Henning Greg

    2017-01-01

    Full Text Available Evaluated nuclear data bases currently used for numerical simulation for the development of nuclear reactors still present large uncertainties. Their improvement is necessary, in particular through better reaction models and nuclear data. Among the reactions of interest, (n, xn reactions are of great importance for the operation of a reactor as they modify the neutron spectrum, the neutron population, and produce radioactive species. Experimental data on (n, xnγ reaction provide strong constraints on nuclear reaction mechanism theories. Tungsten isotopes - which are deformed like actinides but do not fission - are of interest to test the models. 182,184,186W(n, xnγ cross sections are measured; results are compared with model calculations by TALYS, EMPIRE and CoH codes.

  2. (n,p) and (n,alpha) measurements using LENZ instrument to improve reaction model prediction

    Science.gov (United States)

    Lee, Hye Young; Devlin, Matthew; Haight, Robert; Manning, Brett; Mosby, Shea

    2015-10-01

    Understanding neutron-induced charged particle reactions is of interest for nuclear astrophysics and applied nuclear energy. Often, direct measurements of these reactions are not feasible at neutron beam facilities due to the short half-lives of the targets and the reduced cross sections at astrophysically relevant energies given the large Coulomb barriers. Instead, the Hauser-Feshbach formalism is used to study this reaction mechanism for predicting cross sections. We have developed the LENZ (Low Energy n,z) instrument to measure the (n,p) and (n, α) reactions using a time-of-flight method for incident neutron energies from thermal to several tens of MeV at LANSCE. The LENZ has improved capabilities including a large solid angle, a low detection threshold, and good signal-to-background ratios using waveform digitizers. We have performed an in-beam commissioning measurement on 59Co(n, α/p) at En = 0.7 - 12 MeV. In this paper, we will discuss the results of the 59Co(n, α/p) measurements and present the status of the reaction studies on 16O(n, α) for nuclear energy applications and 77Se(n,p) for reaction mechanism studies. This work is funded by the US Department of Energy-Los Alamos National Security, LLC under Contract DE-AC52-06NA25396.

  3. Gamma Ray Production Cross-Sections from Deuteron Induced Nuclear Reaction Measurements

    International Nuclear Information System (INIS)

    Kiss, A.Z.

    2013-01-01

    detector cryostat and the target. The detector was surrounded by a lead shield of 5 cm thickness, and additional shields built from lead bricks were applied close to the entrance diaphragms and the Faraday cup to protect the detector against gamma rays originating from them. The inner wall of the target chamber was covered with a copper lining to decrease gamma radiation caused by backscattered particles from the target. We could reduce the gamma radiation background considerably using this arrangement. The target chamber had an inlet for a particle detector at 135 o to the beam axis. An ORTEC surface barrier detector with a thickness of thickness ofthickness of thickness of thickness of 300μm 300μm 300μm 300 μm was installed in it. A 3 mm diameter copper collimator was applied before the detector. The solid angle was 5.79 ± 0.02 msr measured by two different methods. This setup was intended to detect the backscattered particles from the target. The novelty of the above experimental arrangement in comparison to our previous measurements is the possibility to measure simultaneously gamma rays and particles from the reactions investigated. For the energy calibration of the accelerator the resonance at Ep = 991.9 ± 0.1 keV of the 27 Al(p,γ) 28 Si nuclear reaction was measured on a self-supporting aluminium foil of 750 nm thickness, and the procedure was repeated three months later. From the measurements we concluded that the present calibration is on average 1.9 keV below the reference value with a maximum error of ±1.1 keV. The energy spread between the 1/4 and 3/4 heights of the step was 1.2 keV which is the average of the energy spreads of the two measurements. Because we intended to use a deuteron beam, it was necessary to manipulate some of the equipment of the beam transport system to switch from protons to deuterons, which could change the energy calibration of the accelerator by a few keV (as was shown above). To avoid this uncertainty we tried to find a

  4. Direct Measurements of Half-Cycle Reaction Heats during Atomic Layer Deposition by Calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Lownsbury, James M. [Department; Gladden, James A. [Department; Campbell, Charles T. [Department; Department; Kim, In Soo [Materials; Martinson, Alex B. F. [Materials

    2017-10-05

    We introduce a new high-temperature adsorption calorimeter that approaches the ideal limit of a heat detector whereby the signal at any time is proportional to the heat power being delivered to the sample and prove its sensitivity for measuring pulse-to-pulse heats of half-reactions during atomic layer deposition (ALD) at 400 K. The heat dynamics of amorphous Al2O3 growth via sequential self-limiting surface reaction of trimethylaluminum (TMA) and H2O is clearly resolved. Calibration enables quantitation of the exothermic TMA and H2O half-reactions with high precision, -343 kJ/mol TMA and -251 kJ/mol H2O, respectively. A time resolution better than 1 ms is demonstrated, allowing for the deconvolution of at least two distinct surface reactions during TMA microdosing. It is further demonstrated that this method can provide the heat of reaction versus extent of reaction during each precursors half-reaction, thus providing even richer mechanistic information on the surface processes involved. The broad applicability of this novel calorimeter is demonstrated through excellent signal-to-noise ratios of less exothermic ALD half-reactions to produce TiO2 and MnO.

  5. Measurement of reaction rates of interest in stellar structure and evolution

    Energy Technology Data Exchange (ETDEWEB)

    Terrasi, F.; D`Onofrio, A. [Dipt. di Scienze Ambientali, Seconda Univ. di Napoli, Caserta (Italy)]|[INFN, Napoli (Italy); Campajola, L.; Imbriani, G. [INFN, Napoli (Italy)]|[Dipt. di Scienze Fisiche, Univ. Federico II, Napoli (Italy); Gialanella, L. [INFN, Napoli (Italy)]|[Dipt. di Scienze Fisiche, Univ. Federico II, Napoli (Italy)]|[Inst. fuer Experimentalphysik III, Ruhr-Univ. Bochum, Bochum (Germany); Greife, U.; Rolfs, C.; Strieder, F.; Trautvetter, H.P. [Inst. fuer Experimentalphysik III, Ruhr-Univ. Bochum, Bochum (Germany); Roca, V.; Romano, M. [INFN, Napoli (Italy)]|[Dipt. di Scienze Fisiche, Univ. Federico II, Napoli (Italy); Straniero, O. [Osservatorio Astronomico di Collurania, Teramo (Italy)

    1998-06-01

    Accurate determinations of reaction rates at astrophysical energies are very important in stellar structure and evolution studies. The cases of two key reactions, namely {sup 7}Be(p,{gamma}){sup 8}B and {sup 12}C({alpha},{gamma}){sup 16}O are discussed, both from the point of view of their astrophysical interest and of the experimental difficulties in the measurement of their cross section. (orig.)

  6. Measurement of the effective thermal cross section of {sup 134}Cs by triple neutron capture reaction

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Shoji; Harada, Hideo; Katoh, Toshio [Power Reactor and Nuclear Fuel Development Corp., Tokai, Ibaraki (Japan). Tokai Works; Hatsukawa, Yuichi; Shinohara, Nobuo; Hata, Kentaro; Kobayashi, Katsutoshi; Motoishi, Shoji; Tanase, Masakazu

    1998-03-01

    The effective thermal cross section ({sigma}{sub eff}) of the {sup 134}Cs(n,{gamma}){sup 135}Cs reaction was measured by the activation method and the {gamma}-ray spectroscopic method in order to obtain fundamental data for research on the transmutation of nuclear wastes. The effective thermal cross section of the reaction {sup 134}Cs(n,{gamma}){sup 135}Cs was found to be 140.6{+-}8.5 barns. (author)

  7. Reaction Measurements with the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) Gas Jet Target

    Science.gov (United States)

    Chipps, K. A.; Jensa Collaboration

    2017-09-01

    The development of radioactive ion beams for reaction measurements was a major step forward in nuclear astrophysics, reactions, and structure. However, the move to inverse kinematics presented unique difficulties, in particular with regard to the targets used in such studies. Lower beam intensities may require thicker targets, but this negatively affects the experimental resolution and potential backgrounds. A recent development toward studies of nuclear reactions is the commissioning of the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target. The JENSA system provides a pure, homogeneous, highly localized, dense, and robust gaseous target for radioactive ion beam studies. Charged-particle reactions measurements made with gas jet targets can be cleaner and display better resolution than with traditional targets. With the availability of pure and localized gas jet targets in combination with developments in exotic radioactive ion beams and next-generation detector and spectrometer systems, the range of reaction studies that are experimentally possible is vastly expanded. This talk will focus on the benefits of performing reaction measurements with a gas jet target, including discussion of several example cases using JENSA. Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy. This work was supported by DOE, NNSA, and NSF.

  8. Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Titanium

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers procedures for measuring reaction rates by the activation reactions 46Ti(n,p) 46Sc + 47Ti(n, np)46Sc. Note 1—Since the cross section for the (n,np) reaction is relatively small for energies less than 12 MeV and is not easily distinguished from that of the (n,p) reaction, this test method will refer to the (n,p) reaction only. 1.2 The reaction is useful for measuring neutrons with energies above approximately 4.4 MeV and for irradiation times up to about 250 days (for longer irradiations, see Practice E 261). 1.3 With suitable techniques, fission-neutron fluence rates above 109 cm–2·s–1 can be determined. However, in the presence of a high thermal-neutron fluence rate, 46Sc depletion should be investigated. 1.4 Detailed procedures for other fast-neutron detectors are referenced in Practice E 261. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all...

  9. A high-statistics measurement of the pp→nn charge-exchange reaction at 875 MeV/c

    International Nuclear Information System (INIS)

    Lamanna, M.; Ahmidouch, A.; Birsa, R.; Bradamante, F.; Bressan, A.; Bressani, T.; Dalla Torre-Colautti, S.; Giorgi, M.; Heer, E.; Hess, R.; Kunne, R.A.; Lechanoine-Le Luc, C.; Martin, A.; Mascarini, C.; Masoni, A.; Penzo, A.; Rapin, D.; Schiavon, P.; Tessarotto, F.

    1995-01-01

    A new measurement of the differential cross section and of the analysing power A 0n of the charge-exchange reaction pp→nn at 875 MeV/c is presented. The A 0n data cover the entire angular range and constitute a considerable improvement over previously published data, both in the forward and in the backward hemisphere. The cross-section data cover only the backward region, but are unique at this energy. A careful study of the long-term drifts of the apparatus has allowed to fully exploit the good statistics of the data. ((orig.))

  10. Measurement of the vector np → dπ{sup 0}π{sup 0} reaction with polarized beam in the region of the d*(2380) resonance

    Energy Technology Data Exchange (ETDEWEB)

    Adlarson, P.; Calen, H.; Fransson, K.; Gullstroem, C.O.; Heijkenskjoeld, L.; Johansson, T.; Marciniewski, P.; Wolke, M.; Zlomanczuk, J. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); Augustyniak, W.; Marianski, B.; Morsch, H.P.; Trzcinski, A.; Zupranski, P. [National Centre for Nuclear Research, Department of Nuclear Physics, Warsaw (Poland); Bardan, W.; Ciepal, I.; Czerwinski, E.; Jarczyk, L.; Kamys, B.; Khatri, G.; Kistryn, S.; Krzemien, W.; Magiera, A.; Moskal, P.; Rudy, Z.; Rundel, O.; Schaetti-Ozerianska, I.; Skurzok, M.; Smyrski, J.; Wronska, A.; Zielinski, M.J. [Jagiellonian University, Institute of Physics, Krakow (Poland); Bashkanov, M. [University of Edinburgh, James Clerk Maxwell Building, School of Physics and Astronomy, Edinburgh (United Kingdom); Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Bergmann, F.S.; Demmich, K.; Huesken, N.; Khoukaz, A.; Sitterberg, K.; Taeschner, A. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Berlowski, M.; Stepaniak, J. [National Centre for Nuclear Research, High Energy Physics Department, Warsaw (Poland); Bhatt, H.; Varma, R. [Indian Institute of Technology Bombay, Department of Physics, Powai, Maharashtra (India); Bondar, A.; Kuzmin, A.; Shwartz, B. [Budker Institute of Nuclear Physics of SB RAS, Novosibirsk (Russian Federation); Novosibirsk State University, Novosibirsk (Russian Federation); Buescher, M.; Engels, R.; Goldenbaum, F.; Hejny, V.; Khan, F.A.; Lersch, D.; Lorentz, B.; Ohm, H.; Prasuhn, D.; Schadmand, S.; Sefzick, T.; Serdyuk, V.; Stassen, R.; Sterzenbach, G.; Stockhorst, H.; Zurek, M. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Clement, H. [Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); University of Tuebingen, Kepler Center for Astro- and Particle Physics, Tuebingen (Germany); Erven, A.; Erven, W.; Kemmerling, G.; Kleines, H.; Wuestner, P. [Forschungszentrum Juelich, Zentralinstitut fuer Engineering, Elektronik und Analytik, Juelich (Germany); Eyrich, W.; Zink, A. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Fedorets, P. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); State Scientific Center of the Russian Federation, Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Foehl, K. [Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Goswami, A.; Roy, A. [Indian Institute of Technology Indore, Department of Physics, Indore, Madhya Pradesh (India); Grigoryev, K. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Petersburg Nuclear Physics Institute, High Energy Physics Division, Gatchina, Leningrad district (Russian Federation); Kirillov, D.A.; Piskunov, N.M. [Joint Institute for Nuclear Physics, Veksler and Baldin Laboratory of High Energiy Physics, Dubna, Moscow region (Russian Federation); Klos, B.; Stephan, E. [University of Silesia, August Chelkowski Institute of Physics, Katowice (Poland); Kulessa, P.; Pysz, K.; Siudak, R.; Szczurek, A. [Polish Academy of Sciences, The Henryk Niewodniczanski Institute of Nuclear Physics, Krakow (Poland); Kupsc, A.; Pszczel, D. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); National Centre for Nuclear Research, High Energy Physics Department, Warsaw (Poland); Lalwani, K. [Malaviya National Institute of Technology Jaipur, JLN Marg, Department of Physics, Jaipur, Rajasthan (India); Maier, R.; Stroeher, H. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, JARA-FAME, Juelich Aachen Research Alliance, Juelich (Germany); RWTH Aachen, Aachen (Germany); Perez del Rio, E. [Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Pyszniak, A. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); Jagiellonian University, Institute of Physics, Krakow (PL); Ritman, J. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (DE); Forschungszentrum Juelich, JARA-FAME, Juelich Aachen Research Alliance, Juelich (DE); RWTH Aachen, Aachen (DE); Ruhr-Universitaet Bochum, Institut fuer Experimentalphysik I, Bochum (DE); Sawant, S. [Indian Institute of Technology Bombay, Department of Physics, Powai, Maharashtra (IN); Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (DE); Skorodko, T. [Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (DE); University of Tuebingen, Kepler Center for Astro- and Particle Physics, Tuebingen (DE); Tomsk State University, Department of Physics, Tomsk (RU); Sopov, V. [State Scientific Center of the Russian Federation, Institute for Theoretical and Experimental Physics, Moscow (RU); Yamamoto, A. [High Energy Accelerator Research Organisation KEK, Tsukuba, Ibaraki (JP); Zabierowski, J. [National Centre for Nuclear Research, Department of Astrophysics, Lodz (PL); Collaboration: WASA-at-COSY Collaboration

    2016-05-15

    We report on a high-statistics measurement of the most basic double-pionic fusion reaction vector np→dπ{sup 0}π{sup 0} over the energy region of the d*(2380) resonance by use of a polarized deuteron beam and observing the double fusion reaction in the quasifree scattering mode. The measurements were performed with the WASA detector setup at COSY. The data reveal substantial analyzing powers and confirm conclusions about the d* resonance obtained from unpolarized measurements. We also confirm the previous unpolarized data obtained under complementary kinematic conditions. (orig.)

  11. Measuring Consumer Reactions to Sponsoring Partnerships Based upon Emotional and Attitudinal Responses

    DEFF Research Database (Denmark)

    Riis Christensen, Sverre

    2004-01-01

    batteries of statements, attitude words and feeling words, are developed and a study is carried out with 470 respondents, randomly selected from the population. The data are analysed and pro-vide expressions of positive and negative attitude reaction and emotional reaction that show marked differences...... in consumer reactions towards sponsored objects of different natures as well as towards potential sponsoring organisations. For instance, the charitable institutions measured in the study elicit larger negative emotional re-sponses than positive responses, corresponding to a negative Net Emotional Response...... to the measurements, and it is suggested that the effects can be measured on the atti-tudes-towards-the sponsor and on the emotion-towards-the sponsor levels. This type of modelling is known as the ELAM model, however the types of independent variables involved is new to research into sponsorship effects. Two...

  12. Cross section measurements of proton capture reactions on Se isotopes relevant to the astrophysical p process

    Science.gov (United States)

    Foteinou, V.; Harissopulos, S.; Axiotis, M.; Lagoyannis, A.; Provatas, G.; Spyrou, A.; Perdikakis, G.; Zarkadas, Ch.; Demetriou, P.

    2018-03-01

    Cross sections of proton capture reactions on 74Se, 78Se, and 80Se have been measured at incident beam energies from 2 to 6 MeV, 1.7 to 3 MeV, and 1.5 to 3.5 MeV, respectively. In the case of Se,8078, cross sections were obtained from in-beam γ -angular distribution measurements, whereas for the 74Se isotope they were derived from off-beam activity measurements. The measured cross sections were compared with calculations performed with the nuclear reaction code talys (version 1.6). A good agreement between theory and experiment was found. Astrophysical S factors and reaction rates deduced from the experimental and calculated cross sections were also compared and the impact of different nuclear ingredients in the calculations on the reaction rates was investigated. It was found that, for certain combinations of nuclear input models, the reaction rates obtained at temperatures relevant to p -process nucleosynthesis differ by a factor 2 at the most, differences that are well within the acceptable deviations of calculated p -nuclei abundances and observations.

  13. Measurement of Total Reaction Cross-sections with Heavy Ions at the SC

    CERN Multimedia

    2002-01-01

    The aim of this experiment is the measurement of heavy ion total reaction cross-sections in the energy range 40-86 MeV/A with the anti-coincidence beam attenuation technique. A system of 19 @DE scintillation detectors together with a time-of-flight measurement is used for detection of the residual beam. The results will complete measurements at the Grenoble cyclotron and post accelerator over the energy range 10-40 MeV/A.

  14. Relationship between measurements of blood oxidative metabolites and skin reaction in irradiated rats

    International Nuclear Information System (INIS)

    Kaneko, Takashi; Goto, Jun; Nomiya, Takuma; Nemoto, Kenji

    2011-01-01

    Recently, oxidative metabolites have been able to be measured by simple small device. It has been reported that the value of oxidative metabolites increases under several conditions such as hypertension, smoking, diabetes mellitus, etc. Radiation used in radiotherapy also causes free radicals and oxidative metabolites, and irradiation causes dermatitis and sometimes causes skin ulcer in the irradiated site. We analyzed the relationships between the value of oxidative metabolites and skin reactions. A certain doses of radiation were irradiated to the right thigh of rats, and oxidative metabolites of rat's blood from caudal vein were measured by d-reactive oxygen metabolites (ROMs) test using an exclusive device. Skin reactions were evaluated according to a skin-reaction grading system from the day before irradiation to day 38 after irradiation. As a results, a significant correlation was shown between irradiation dose and skin grade. And a significant correlation was also shown between the value of oxidative metabolites and irradiation dose. The increase in oxidative metabolites was seen in the Day 16 after irradiation, and that corresponded with the appearance of skin reaction. It was suggested that the value of oxidative metabolites seems to be useful for estimating degree of skin reaction and time to appear skin reaction after irradiation. (author)

  15. Measurement of activation cross sections for quasi-monoenergetic neutron induced reactions of {sup 89}Y

    Energy Technology Data Exchange (ETDEWEB)

    Zaman, Muhammad; Kim, Guinyun; Kim, Kwangsoo; Nadeem, Muhammad [Kyungpook National University, Department of Physics and Center for High Energy Physics, Daegu (Korea, Republic of); Naik, Haladhara [Kyungpook National University, Department of Physics and Center for High Energy Physics, Daegu (Korea, Republic of); Bhabha Atomic Research Centre, Radiochemistry Division, Mumbai (India); Lee, Manwoo [Dongnam Inst. of Radiological and Medical Sciences, Research Center, Busan (Korea, Republic of)

    2017-09-15

    The neutron induced cross sections of the {sup 89}Y(n, 2n){sup 88}Y, {sup 89}Y(n, 3n){sup 87}Y and {sup 89}Y(n, 4n){sup 86}Y reactions were measured in the neutron energy range of 15.2 to 37.2 MeV by using an activation and off-line γ-ray spectrometric technique. The quasi-monoenergetic neutrons used for the above reactions are based on a {sup 9}Be(p, n) reaction. Simulations of the neutron spectra from the Be target were done using the MCNPX 2.6.0 program. Theoretical calculations were performed for the {sup 89}Y(n, 2n){sup 88}Y, {sup 89}Y(n, 3n){sup 87}Y and {sup 89}Y(n, 4n){sup 86}Y reaction cross sections using nuclear model code Talys 1.8. The measured and calculated cross sections were compared with the literature data given in EXFOR and the TENDL-2015 data libraries. The present data of the {sup 89}Y(n, xn) reaction were also compared with the similar data of the {sup 89}Y(γ, xn) reaction to examine the effect of the entrance channel parameters as well as the role of projectiles and ejectiles. (orig.)

  16. Cross sections for nuclide production in proton- and deuteron-induced reactions on 93Nb measured using the inverse kinematics method

    Directory of Open Access Journals (Sweden)

    Nakano Keita

    2017-01-01

    Full Text Available Isotopic production cross sections were measured for proton- and deuteron-induced reactions on 93Nb by means of the inverse kinematics method at RIKEN Radioactive Isotope Beam Factory. The measured production cross sections of residual nuclei in the reaction 93Nb + p at 113 MeV/u were compared with previous data measured by the conventional activation method in the proton energy range between 46 and 249 MeV. The present inverse kinematics data of four reaction products (90Mo, 90Nb, 88Y, and 86Y were in good agreement with the data of activation measurement. Also, the model calculations with PHITS describing the intra-nuclear cascade and evaporation processes generally well reproduced the measured isotopic production cross sections.

  17. Measurement of p+d→3He+γ and comparison with the inverse reaction

    International Nuclear Information System (INIS)

    Nefkens, B.M.K.; Bauer, T.S.; Baba, K.; Boudard, A.; Briscoe, W.J.; Bruge, G.; Faure, J.L.; Gosset, J.; Hegerath, A.; Lugol, J.C.; Silverman, B.H.; Terrien, Y.

    1980-01-01

    Seven differential cross sections of the reaction p+d→ 3 He+γ have been measured at T/sub p/=450 and 550 MeV between 52 0 and 92 0 (theta/sub γ/ c.m.). 3 He's were analyzed by the SPES I spectrometer in coincidence with photons detected by Cerenkov counters. The results are about twice the cross sections of the inverse reaction measured recently by Hegerath et al. and by Argan et al. The data are consistent, however, with the γ+ 3 Hearrow-right-leftp+d data of Heusch et al

  18. [Lower uterine segment thickness measurement in pregnant women with previous caesarean section: intra- and interobserver reliability analysis using bi- and tridimensional ultrasonography].

    Science.gov (United States)

    Barra, Daniela de Abreu; Martins, Wellington de Paula; Gallarretta, Francisco Maximilliano; Nastri, Carolina Oliveira; Nicolau, Luis Guilherme; Mauad Filho, Francisco

    2008-03-01

    to compare the intra and interobserver reproducibility of the total thickness measurement of the inferior uterine segment (IUS), through the abdominal route, and of the muscle layer measurement, through the vaginal route, using bi and tridimensional ultrasonography. the IUS thickness measurement of 30 women, between the 36th and 39th weeks of gestation with previous caesarean section, done by two observers, was studied. Abdominal ultrasonography with the patient in both supine and lithotomy position was performed. In the sagittal section, the IUS was identified and four bidimensional images and two tridimensional blocks of the total thickness were collected through the abdominal route, and the same for the muscle layer, through the vaginal route. Tridimensional acquisitions were manipulated in the multiplanar mode. The time was measured with a chronometer. Reproducibility was evaluated by the computation of the absolute difference between measurements, the ratio of differences smaller than 1 mm, the intraclass coefficient (ICC), and the Bland and Altman's concordance limits. the average bidimensional measurement of IUS thickness was 7.4 mm through the abdominal and 2.7 mm through the vaginal route, and the tridimensional measurement was 6.9 mm through the abdominal and 5.1 mm through the vaginal route. Intra- and interobserver reproducibility of vaginal versus abdominal route: smaller absolute difference (0.2-0.4 mm versus 0.8-1.5 mm), greater ratio of differences (85.8-97.8% versus 48.7-72,8%), with p0.05[A1] and similar lower concordance limits (-38 to 3.4 versus -3.6 to 4 mm) for tridimensional ultrasonography and ICC (0.6-0.9 versus 0.7-0.9). from the above, we came to the conclusion that the measurement of the IUS muscle layer, through the vaginal route using tridimensional ultrasonography is more reproducible. Nevertheless, our results do not indicate that this measurement shows any clinical evidence to predict uterine tear, as that was not the aim of this

  19. Paradoxical reaction to the treatment of tuberculosis uncovering previously silent meningeal disease Reação paradoxal ao tratamento da tuberculose revelando doença meníngea previamente silenciosa

    Directory of Open Access Journals (Sweden)

    Walter A. Eyer-Silva

    2002-02-01

    Full Text Available The development of paradoxical clinical worsening following initiation of tuberculosis treatment may complicate the clinical course of both HIV-infected and uninfected patients. We report a severe manifestation of the so called paradoxical reaction to the treatment of tuberculosis that unmasked previously silent meningeal disease in a 34-year-old HIV-infected male patient.O desenvolvimento de piora clínica paradoxal como resposta ao início do tratamento da tuberculose pode complicar a evolução de pacientes com e sem infecção pelo HIV. Apresentamos uma grave manifestação da chamada reação paradoxal ao tratamento da tuberculose, que revelou doença meníngea previamente silenciosa em um paciente HIV-positivo de 34 anos.

  20. Isothermal calorimetry: Impact of measurements error on heat of reaction and kinetic calculations

    International Nuclear Information System (INIS)

    Papadaki, Maria; Nawada, Hosadu P.; Gao, Jun; Fergusson-Rees, Andrew; Smith, Michael

    2007-01-01

    Heat flow and power compensation calorimetry measures the power generation of a reaction via an energy balance over an appropriately designed isothermal reactor. However, the measurement of the power generated by a reaction is a relative measurement, and calibrations are used to eliminate the contribution of a number of unknown factors. In this work the effect of the error in the measurement of temperature of electric power used in the calibrations and the heat transfer coefficient and baseline is assessed. It has been shown that the error in all aforementioned quantities reflects on the baseline and it can have a very serious impact on the accuracy of the measurement. The influence of the fluctuation of ambient temperature has been evaluated and a means of a correction that reduces its impact has been implemented. The temperature of dosed material is affected by the heat loses if reaction is performed at high temperature and low dosing rate. An experimental methodology is presented that can provide means of assessment of the actual temperature of the dosed material. Depending on the reacting system, the heat of evaporation could be included in the baseline, especially if non-condensable gases are produced during the course of the reaction

  1. Apparatus for production, measurement and reaction studies of dissociated gases at elevated temperatures

    Science.gov (United States)

    Christian, J. D.; Gilbreath, W. P.

    1975-01-01

    An apparatus is described which is used for the controlled production, characterization, and study of dissociated gases in a microwave discharge at elevated temperatures. A unique feature is the ability to produce and study a microwave discharge plasma in the heated zone. This allows elevated temperature reactions to be studied in high concentrations of dissociated gases. Further, the system permits weight change measurements of specimens in the plasma, thus facilitating reaction rate determinations. Included is a description of a cavity for use on a 50-mm diameter cylindrical reactor. The effects of flow rate, pressure, temperature, power, metal sample, and sampling position on dissociation percentage of oxygen in the apparatus are described as well as a technique for sample temperature measurements in the plasma which permits determination of high temperature recombination coefficients and reaction rates.

  2. Label-free measurements of reaction kinetics using a droplet-based optofluidic device.

    Science.gov (United States)

    Mao, Zhangming; Guo, Feng; Xie, Yuliang; Zhao, Yanhui; Lapsley, Michael Ian; Wang, Lin; Mai, John D; Costanzo, Francesco; Huang, Tony Jun

    2015-02-01

    Label-free measurements of the reaction kinetics of a small sample volume are essential for efficient drug discovery, requiring methods and systems that are rapid, accurate, and cost-effective. Herein, we present an integrated optofluidic system for label-free characterization of reactions in a nanoliter reagent volume. This system contains a droplet-based microfluidic sampling section and an optical fiber-based spectroscopy detection section. By manipulating droplets containing reagents at certain concentrations at different times, quantifiable measurements via absorption spectroscopy can be made in a simple, sensitive, and high-throughput manner. We have demonstrated our system's capability by performing potency (IC50) assays of an inhibitor in a TEM-1 β-lactamase (enzyme) and nitrocefin (substrate) system. This integrated platform can potentially provide an automated, label-free, and low-cost method for many other assays of reaction kinetics. © 2014 Society for Laboratory Automation and Screening.

  3. Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Aluminum

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method covers procedures measuring reaction rates by the activation reaction 27Al(n,α)24Na. 1.2 This activation reaction is useful for measuring neutrons with energies above approximately 6.5 MeV and for irradiation times up to about 2 days (for longer irradiations, see Practice E261). 1.3 With suitable techniques, fission-neutron fluence rates above 106 cm−2·s−1 can be determined. 1.4 Detailed procedures for other fast neutron detectors are referenced in Practice E261. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  4. Rate Coefficient Measurements of the Reaction CH3 + O2 = CH3O + O

    Science.gov (United States)

    Hwang, S. M.; Ryu, Si-Ok; DeWitt, K. J.; Rabinowitz, M. J.

    1999-01-01

    Rate coefficients for the reaction CH3 + O2 = CH3O + O were measured behind reflected shock waves in a series of lean CH4-O2-Ar mixtures using hydroxyl and methyl radical diagnostics. The rate coefficients are well represented by an Arrhenius expression given as k = (1.60(sup +0.67, sub -0.47 ) x 10(exp 13) e(-15813 +/- 587 K/T)/cubic cm.mol.s. This expression, which is valid in the temperature range 1575-1822 K, supports the downward trend in the rate coefficients that has been reported in recent determinations. All measurements to date, including the present study, have been to some extent affected by secondary reactions. The complications due to secondary reactions, choice of thermochemical data, and shock-boundary layer interactions that affect the determination of the rate coefficients are examined.

  5. Rate Coefficient Measurements of the Reaction CH3+O2+CH3O+O

    Science.gov (United States)

    Hwang, S. M.; Ryu, Si-Ok; DeWitt, K. J.; Rabinowitz, M. J.

    1999-01-01

    Rate coefficients for the reaction CH3 + O2 = CH3O + O were measured behind reflected shock waves in a series of lean CH4-O2-Ar mixtures using hydroxyl and methyl radical diagnostics. The rate coefficients are well represented by an Arrhenius expression given as k = (1.60(sup +0.67, -0.47)) X 10(exp 13) exp(- 15813 +/- 587 K/T)cc/mol s. This expression, which is valid in the temperature range 1575-1822 K, supports the downward trend in the rate coefficients that has been reported in recent determinations. All measurements to date, including the present study, have been to some extent affected by secondary reactions. The complications due to secondary reactions, choice of thermochemical data, and shock-boundary layer interactions that affect the determination of the rate coefficients are examined.

  6. Measuring Dynamic and Kinetic Information in the Previously Inaccessible Supra-tc Window of Nanoseconds to Microseconds by Solution NMR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Donghan Lee

    2013-09-01

    Full Text Available Nuclear Magnetic Resonance (NMR spectroscopy is a powerful tool that has enabled experimentalists to characterize molecular dynamics and kinetics spanning a wide range of time-scales from picoseconds to days. This review focuses on addressing the previously inaccessible supra-τc window (defined as τc < supra-τc < 40 μs; in which τc is the overall tumbling time of a molecule from the perspective of local inter-nuclear vector dynamics extracted from residual dipolar couplings (RDCs and from the perspective of conformational exchange captured by relaxation dispersion measurements (RD. The goal of the first section is to present a detailed analysis of how to extract protein dynamics encoded in RDCs and how to relate this information to protein functionality within the previously inaccessible supra-τc window. In the second section, the current state of the art for RD is analyzed, as well as the considerable progress toward pushing the sensitivity of RD further into the supra-τc scale by up to a factor of two (motion up to 25 ms. From the data obtained with these techniques and methodology, the importance of the supra-τ c scale for protein function and molecular recognition is becoming increasingly clearer as the connection between motion on the supra-τc scale and protein functionality from the experimental side is further strengthened with results from molecular dynamics simulations.

  7. Ambulatory measurement of ground reaction force and estimation of ankle and foot dynamics

    NARCIS (Netherlands)

    Schepers, H. Martin; Koopman, Hubertus F.J.M.; Baten, Christian T.M.; Veltink, Petrus H.

    INTRODUCTION Traditionally, human body movement analysis is done in so-called ‘gait laboratories’. In these laboratories, body movement is measured by a camera system using optical markers, the ground reaction force by a force plate fixed in the floor, and the muscle activity by EMG. From the body

  8. Simultaneous time-resolved measurement of the reaction rates and the refractive index of photopolymerization processes

    NARCIS (Netherlands)

    Bak, Tomasz M; Beusink, J Bianca; Subramaniam, Vinod; Kanger, Johannes S

    2010-01-01

    We explore the use of imaging surface plasmon resonance (iSPR) to simultaneously measure the refractive index and reaction rates of the commercially available Ormocore photosensitive resist during photopolymerization. To this end, we adapted a commercially available iSPR device. We demonstrate good

  9. Development of the system for excitation function automatic measurement of nuclear reactions

    International Nuclear Information System (INIS)

    Sapozhnikov, A.B.

    2004-01-01

    Full text: The resonance nuclear reaction method is applied at the tandem accelerator UKP-2-1 to determinate films thickness and obtain light element depth distribution. The system for automatic measurement of the nuclear reaction excitation curve has been developed. It allowed to obtain an excitation function of nuclear reaction using continuous changing potential of the target with energy step of 6 eV. Saw-tooth voltage with amplitude up to 6 kV from the block of scanning beam is fed to a target. The amplitude is determined by constant voltage from the scanning beam block control. Nal(Tl) detector detects gamma quanta - the products of a nuclear reaction and transforms they in voltage impulses. The impulses through the amplifier income in the single-channel analyzer which forms impulses to start the analog-to-digital converter. The value of saw-tooth voltage corresponding to the moment of gamma quantum detection is read by the analog-to-digital converter, where it is transformed to digital code and transmitted to the computer. The computer program has been developed to control the process of accumulation of excitation function. The dependence a detected γ-quanta yield from a target potential is automatically plotted by the program. This dependence corresponds to the nuclear reaction excitation function. If scanning amplitude is not enough in order to scan need depth of a sample, an operator increases energy of the proton beam changing high voltage potential of the terminal up 3 keV and measures the nuclear reaction excitation function with the new energy. This procedure can be repeated some times. After that 'sewing' of excitation functions is carried out by the program under the hypothesis that nuclear reaction yield in last points be identical

  10. Gamma-ray multiplicity measurements in the 28Si + 64Ni reaction at 163.8 MeV

    International Nuclear Information System (INIS)

    Di Pietro, A.; Cardella, G.; Musumarra, A.; Papa, M.; Pappalardo, G.; Rizzo, F.; De Rosa, A.; D'Onofrio, A.; Inglima, G.; Roca, V.; Romano, M.; Romoli, M.; Sandoli, M.; Terrasi, F.; Fioretto, E.

    1994-01-01

    The 28 Si+ 64 Ni reaction at 163.8 MeV incident energy is studied by measuring in coincidence γ-rays and charged particles identified from Z 2 to Z = 16. The transition from quasi-elastic to more damped reactions is observed when the difference between the detected charge and the projectile one is increased. The strong influence of the particle decay on the measured γ-ray multiplicity is evidenced with the help of the statistical model computer code CASCADE. Dissipative events are well described in the rolling limit with excitation energy equally shared between the fragments. The overall agreement is lost for the fragments with the projectile charge which show a small value of the γ-multiplicity even for dissipative events. This is probably connected with the previously observed non statistical behavior of gamma rays emitted in coincidence with projectile-like fragments. In the alpha-spectrum measured in coincidence with gamma-rays, the deexcitation of fused systems is clearly separated from in flight emission of deep inelastic fragments. The low measured gamma-ray multiplicity for fusion events is qualitatively explained taking into account the effect of alpha-emission in the statistical decay. (orig.)

  11. Measurement of reaction cross sections of fission products induced by DT neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Daisuke; Murata, Isao; Takahashi, Akito [Osaka Univ., Suita (Japan)

    1998-03-01

    With the view of future application of fusion reactor to incineration of fission products, we have measured the {sup 129}I(n,2n){sup 128}I reaction cross section by DT neutrons with the activation method. The measured cross section was compared with the evaluated nuclear data of JENDL-3.2. From the result, it was confirmed that the evaluation overestimated the cross section by about 20-40%. (author)

  12. [Inter-observer variability of decision concerning the route of delivery in case of one previous cesarean section and abnormal pelvic measures].

    Science.gov (United States)

    Bourdon, M; Ceccaldi, P F; Girard, G; Koskas, M; Goffinet, F; Le Ray, C

    2016-11-01

    To study inter-observer variability of decision concerning the route of delivery using pelvimetry in case of one previous cesarean section and abnormal pelvic measures. Observational study conducted in 2014 in 4 university maternity units among 36 obstetricians. Two groups of obstetricians - as they practiced in a center where pelvimetry was routinely performed (n=12) or not (n=24) - had to choose a route of delivery for 10 clinical cases of women with a single uterine scar and a tight pelvis. The "routine pelvimetry" group had pelvimetry results. The group "no pelvimetry" became aware of pelvimetry results as a second step and had to indicate whether this information changed or not their management. The measurement of the inter-observer variability was estimated by estimating the proportion of agreement according to Grant method. The proportion of agreements of an attempted vaginal delivery between obstetricians in the group "routine pelvimetry" was 64.7% (95% CI [61-68.5]) and 97.3% (95% CI [96.4 to 98.3]) in the group "no pelvimetry", prior knowledge of pelvimetry results. An attempted vaginal delivery was decided in 77.5% versus 98.7% (Pcesarean section, in case of tight pelvis discovered after pelvimetry, inter-observer variability of decision concerning the route of delivery is increased. Centers that choose to continue using the routine pelvimetry should develop procedures to limit this variability. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. Identification of mechanisms in heavy ion reactions by measurement of angular correlations

    International Nuclear Information System (INIS)

    Carlin Filho, N.

    1987-01-01

    The identification of reaction mechanisms in light heavy-ion collisions has been performed within the framework of the three body kinematics, by means of angular correlation measurements. The 16 O+ 27 Al, 16 +O+ 28 Si and 10 B+ 27 Al reactions were investigated at Laboratory bombarding energies of 64 MeV, 64 and 48 MeV, respectively. Contributions of transfer-reemission and projectile sequential decay mechanisms were identified by the analysis of the relative kinetic energy of the final state components, excitation energies of the system at the intermediate stages, and also by means of fits to theoretical predictions for the angular correlations. (author) [pt

  14. Breakup Reactions and Exclusive Measurements in the 6,7Li+144Sm Systems

    International Nuclear Information System (INIS)

    Heimann, D. Martinez; Pacheco, A. J.; Arazi, A.; Figueira, J. M.; Negri, A. E.; Capurro, O. A.; Carnelli, P.; Fimiani, L.; Grinberg, P.; Marti, G. V.; Testoni, J. E.; Monteiro, D. S.; Niello, J. O. Fernandez; Marta, H. D.

    2009-01-01

    The breakup of the projectile-like nuclei in reactions induced by 30 MeV 6 Li and 7 Li beams on a 144 Sm target have been measured through the coincident detection of the in-plane emitted light particles. The primary ion that undergoes breakup has been identified and the physically meaningful variables that characterize the reaction have been obtained on a purely experimental basis. Distributions have been obtained for both the binary emission angle and for the breakup emission angle in the reference frame of the breakup products.

  15. Measuring both negative and positive reactions to giving care to cancer patients : psychometric qualities of the Caregiver Reaction Assessment (CRA)

    NARCIS (Netherlands)

    Nijboer, C; Triemstra, M; Sanderman, R.; van den Bos, G.A M

    The Caregiver Reaction Assessment Scale (CRA) is an instrument designed to assess specific aspects of the caregiving situation, including both negative and positive dimensions of caregiving reactions. This paper addresses the psychometric qualities of the CRA in a multicenter study among partners of

  16. Measuring both negative and positive reactions to giving care to cancer patients: psychometric qualities of the Caregiver Reaction Assessment (CRA)

    NARCIS (Netherlands)

    Nijboer, C.; Triemstra, M.; Tempelaar, R.; Sanderman, R.; van den Bos, G. A.

    1999-01-01

    The Caregiver Reaction Assessment Scale (CRA) is an instrument designed to assess specific aspects of the caregiving situation, including both negative and positive dimensions of caregiving reactions. This paper addresses the psychometric qualities of the CRA in a multicenter study among partners of

  17. High-precision (p,t) reaction measurement to determine Ne-18(alpha,p)Na-21 reaction rates

    NARCIS (Netherlands)

    Matic, A.; van den Berg, A. M.; Harakeh, M. N.; Wörtche, H. J.; Berg, G. P. A.; Couder, M.; Fisker, J. L.; Goerres, J.; LeBlanc, P.; O'Brien, S.; Wiescher, M.; Fujita, K.; Hatanaka, K.; Sakemi, Y.; Shimizu, Y.; Tameshige, Y.; Tamii, A.; Yosoi, M.; Adachi, T.; Fujita, Y.; Shimbara, Y.; Fujita, H.; Wakasa, T.; Hess, P. O.; Brown, B. A.; Schatz, H.

    2009-01-01

    x-ray bursts are identified as thermonuclear explosions in the outer atmosphere of accreting neutron stars. The thermonuclear runaway is fueled by the alpha p process that describes a sequence of (alpha,p) reactions triggered by the Ne-18(alpha,p)Na-21 breakout reaction from the hot CNO cycles. We

  18. Multi-Sampling Ionization Chamber (MUSIC) for measurements of fusion reactions with radioactive beams

    International Nuclear Information System (INIS)

    Carnelli, P.F.F.; Almaraz-Calderon, S.; Rehm, K.E.; Albers, M.; Alcorta, M.; Bertone, P.F.; Digiovine, B.; Esbensen, H.; Fernández Niello, J.; Henderson, D.; Jiang, C.L.; Lai, J.; Marley, S.T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R.C.; Paul, M.; Ugalde, C.

    2015-01-01

    A detection technique for high-efficiency measurements of fusion reactions with low-intensity radioactive beams was developed. The technique is based on a Multi-Sampling Ionization Chamber (MUSIC) operating as an active target and detection system, where the ionization gas acts as both target and counting gas. In this way, we can sample an excitation function in an energy range determined by the gas pressure, without changing the beam energy. The detector provides internal normalization to the incident beam and drastically reduces the measuring time. In a first experiment we tested the performance of the technique by measuring the 10,13,15 C+ 12 C fusion reactions at energies around the Coulomb barrier

  19. Multi-Sampling Ionization Chamber (MUSIC) for measurements of fusion reactions with radioactive beams

    Energy Technology Data Exchange (ETDEWEB)

    Carnelli, P.F.F. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, B1650KNA, San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, Av. Rivadavia 1917, C1033AAJ Buenos Aires (Argentina); Almaraz-Calderon, S. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Rehm, K.E., E-mail: rehm@anl.gov [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Albers, M.; Alcorta, M.; Bertone, P.F.; Digiovine, B.; Esbensen, H. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Fernández Niello, J. [Laboratorio TANDAR, Comisión Nacional de Energía Atómica, Av. Gral. Paz 1499, B1650KNA, San Martín, Buenos Aires (Argentina); Universidad Nacional de San Martín, Campus Miguelete, B1650BWA San Martín, Buenos Aires (Argentina); Henderson, D.; Jiang, C.L. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Lai, J. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Marley, S.T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R.C. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Paul, M. [Racah Institute of Physics, Hebrew University, Jerusalem (Israel); Ugalde, C. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2015-11-01

    A detection technique for high-efficiency measurements of fusion reactions with low-intensity radioactive beams was developed. The technique is based on a Multi-Sampling Ionization Chamber (MUSIC) operating as an active target and detection system, where the ionization gas acts as both target and counting gas. In this way, we can sample an excitation function in an energy range determined by the gas pressure, without changing the beam energy. The detector provides internal normalization to the incident beam and drastically reduces the measuring time. In a first experiment we tested the performance of the technique by measuring the {sup 10,13,15}C+{sup 12}C fusion reactions at energies around the Coulomb barrier.

  20. Measurement of the 2H(7Be, 6Li)3He reaction rate and its contribution to the primordial lithium abundance

    Science.gov (United States)

    Li, Er-Tao; Li, Zhi-Hong; Yan, Sheng-Quan; Su, Jun; Guo, Bing; Li, Yun-Ju; Wang, You-Bao; Lian, Gang; Zeng, Sheng; Chen, Si-Zhe; Ma, Shao-Bo; Li, Xiang-Qing; He, Cao; Sun, Hui-Bin; Liu, Wei-Ping

    2018-04-01

    In the standard Big Bang nucleosynthesis (SBBN) model, the lithium puzzle has attracted intense interest over the past few decades, but still has not been solved. Conventionally, the approach is to include more reactions flowing into or out of lithium, and study the potential effects of those reactions which were not previously considered. 7Be(d, 3He)6Li is a reaction that not only produces 6Li but also destroys 7Be, which decays to 7Li, thereby affecting 7Li indirectly. Therefore, this reaction could alleviate the lithium discrepancy if its reaction rate is sufficiently high. However, there is not much information available about the 7Be(d, 3He)6Li reaction rate. In this work, the angular distributions of the 7Be(d, 3He)6Li reaction are measured at the center of mass energies E cm = 4.0 MeV and 6.7 MeV with secondary 7Be beams for the first time. The excitation function of the 7Be(d, 3He)6Li reaction is first calculated with the computer code TALYS and then normalized to the experimental data, then its reaction rate is deduced. A SBBN network calculation is performed to investigate its influence on the 6Li and 7Li abundances. The results show that the 7Be(d, 3He)6Li reaction has a minimal effect on 6Li and 7Li because of its small reaction rate. Therefore, the 7Be(d, 3He)6Li reaction is ruled out by this experiment as a means of alleviating the lithium discrepancy. Supported by National Natural Science Foundation of China (11375269, 11505117, 11490560, 11475264, 11321064), Natural Science Foundation of Guangdong Province (2015A030310012), 973 program of China (2013CB834406) and National key Research and Development Province (2016YFA0400502)

  1. Measurements of deuteron-induced reaction cross-sections on natural nickel up to 24 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Usman, Ahmed Rufai [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Department of Physics, Umaru Musa Yar’adua University, Katsina (Nigeria); Khandaker, Mayeen Uddin, E-mail: mu_khandaker@yahoo.com [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Haba, Hiromitsu; Murakami, Masashi [Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan); Otuka, Naohiko [Nuclear Data Section, Division of Physical and Chemical Sciences, Department of Nuclear Sciences and Applications, International Atomic Energy Agency, A-1400 Vienna (Austria)

    2016-02-01

    Deuteron-induced cross-sections of the {sup nat}Ni(d,x){sup 55–58,60}Co, {sup 57}Ni, {sup 52g,54}Mn and {sup 61}Cu reactions were measured from the respective threshold energies to 24 MeV by using a stacked-foil activation technique combined with HPGe γ-ray spectrometry. The results were compared with the available experimental data and also with the evaluated data in the TENDL-2014 library. Present results show a reasonable agreement with the recently reported experimental data while a partial agreement is found with the evaluated data. The results are expected to further enrich the experimental database and to understand the discrepancies among the previous measurements. The {sup nat}Ni(d,x){sup 61}Cu cross-sections recommended by the IAEA overestimate recent experimental ones, and their upgrade has been proposed.

  2. Cross section measurement of alpha particle induced nuclear reactions on natural cadmium up to 52MeV.

    Science.gov (United States)

    Ditrói, F; Takács, S; Haba, H; Komori, Y; Aikawa, M

    2016-12-01

    Cross sections of alpha particle induced nuclear reactions have been measured on thin natural cadmium targets foils in the energy range from 11 to 51.2MeV. This work was a part of our systematic study on excitation functions of light ion induced nuclear reactions on different target materials. Regarding the cross sections, the alpha induced reactions are not deeply enough investigated. Some of the produced isotopes are of medical interest, others have application in research and industry. The radioisotope 117m Sn is a very important theranostic (therapeutic + diagnostic) radioisotope, so special care was taken to the results for that isotope. The well-established stacked foil technique followed by gamma-spectrometry with HPGe gamma spectrometers were used. The target and monitor foils in the stack were commercial high purity metal foils. From the irradiated targets 117m Sn, 113 Sn, 110 Sn, 117m,g In, 116m In, 115m In, 114m In, 113m In, 111 In, 110m,g In, 109m In, 108m,g In, 115g Cd and 111m Cd were identified and their excitation functions were derived. The results were compared with the data of the previous measurements from the literature and with the results of the theoretical nuclear reaction model code calculations TALYS 1.8 (TENDL-2015) and EMPIRE 3.2 (Malta). From the cross section curves thick target yields were calculated and compared with the available literature data. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Measurement and analysis of the excitation function for alpha induced reaction on Ga and Sb isotopes

    International Nuclear Information System (INIS)

    Excitation functions for the reactions 69 Ga(αxn)sup(73-x)As, 69 Ga(α,p3n) 69 Ge, 69 Ga(α,2p4n) 67 Ga, 71 Ga(α,xn)sup(75-x)As, 121 Sb(α,xn)sup(125-x)I, 121 Sb(α,p3n) 121 Te and 123 Sb(α,xn)sup(127-x)I were obtained from the measurements of the residual activity of stacked foils of gallium nitrate evaporated on aluminium backings from threshold to 65 MeV. The excitation functions for the production of 74 As, 72 As, 71 As, 69 Ge and 67 Ga from α - induced reactions on Ga and 126 I, 124 I, 123 I, 121 I and 121 Te from α - induced reactions on Sb are presented. The experimental data are compared with calculations considering equilibrium as well as pre-equilibrium reaction mechanism according to the hybrid model of Blann (1971). The high energy part of the excitation functions are dominated by the pre-equilibrium reaction mechanism. Calculations were done using the a priori calculational method of Overlaid Alice Code of Blann. From the reactions 71 Ga(α,3n) 72 As and 123 Sb(α,3n) 124 I an initial exciton number nsub(o)=4(nsub(n)=2, nsub(p)=2, nsub(h)=0) with the mean free path multiplier parameter k set to 2 has been deduced for both the targets. However, there are a few exceptions (i) the theory overestimates the cross-section for the 69 Ga(α,2p4n) 67 Ga reaction whereas it underestimate the cross-section for the 121 Sb(α,p3n) 121 Te reaction and the high energy tail of 121 Sb(α,2n) 123 I excitation function. Factors to which these discrepancies between theory and experiment in case of these reactions may be attributed are indicated. Barring these reactions the overall agreement between theory and experiment is good taking into account the limitations of the theory. (author). 43 refs., 7 tabs., 19 figs

  4. Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Copper

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method covers procedures for measuring reaction rates by the activation reaction 63Cu(n,α)60Co. The cross section for 60Co produced in this reaction increases rapidly with neutrons having energies greater than about 5 MeV. 60Co decays with a half-life of 1925.27 days (±0.29 days)(1) and emits two gamma rays having energies of 1.1732278 and 1.332492 MeV (1). The isotopic content of natural copper is 69.17 % 63Cu and 30.83 % 65Cu (2). The neutron reaction, 63Cu(n,γ)64Cu, produces a radioactive product that emits gamma rays which might interfere with the counting of the 60Co gamma rays. 1.2 With suitable techniques, fission-neutron fluence rates above 109 cm−2·s−1 can be determined. The 63Cu(n,α)60Co reaction can be used to determine fast-neutron fluences for irradiation times up to about 15 years (for longer irradiations, see Practice E261). 1.3 Detailed procedures for other fast-neutron detectors are referenced in Practice E261. 1.4 This standard does not purport to address all of the...

  5. Reaction rate constants of H-abstraction by OH from large ketones: measurements and site-specific rate rules.

    Science.gov (United States)

    Badra, Jihad; Elwardany, Ahmed E; Farooq, Aamir

    2014-06-28

    Reaction rate constants of the reaction of four large ketones with hydroxyl (OH) are investigated behind reflected shock waves using OH laser absorption. The studied ketones are isomers of hexanone and include 2-hexanone, 3-hexanone, 3-methyl-2-pentanone, and 4-methl-2-pentanone. Rate constants are measured under pseudo-first-order kinetics at temperatures ranging from 866 K to 1375 K and pressures near 1.5 atm. The reported high-temperature rate constant measurements are the first direct measurements for these ketones under combustion-relevant conditions. The effects of the position of the carbonyl group (C=O) and methyl (CH3) branching on the overall rate constant with OH are examined. Using previously published data, rate constant expressions covering, low-to-high temperatures, are developed for acetone, 2-butanone, 3-pentanone, and the hexanone isomers studied here. These Arrhenius expressions are used to devise rate rules for H-abstraction from various sites. Specifically, the current scheme is applied with good success to H-abstraction by OH from a series of n-ketones. Finally, general expressions for primary and secondary site-specific H-abstraction by OH from ketones are proposed as follows (the subscript numbers indicate the number of carbon atoms bonded to the next-nearest-neighbor carbon atom, the subscript CO indicates that the abstraction is from a site next to the carbonyl group (C=O), and the prime is used to differentiate different neighboring environments of a methylene group):

  6. Measurement of adenosine triphosphate (ATP) content in single red blood cells using the firefly bioluminescent reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kostuk, R.K.; Muhs, A.G.; Kirkpatrick, F.H.; Gabel, C.W.

    1977-01-01

    A unique optical instrument is described which uses the firefly bioluminscent reaction to measure adenosine triphosphate (ATP) levels in single red blood cells. The method allows chemical content level to be associated with individual cell features. The optical instrument consists of a phase contrast microscope to view cells, a pulsed argon-ion laser to rupture the cell membrane, and a photon counting system to measure the bioluminescent yield. The technique has been calibrated against a standard ATP measurement using bulk analysis methods. The ATP loss mechanism for blood cells in a controlled depletion experiment was also investigated.

  7. Measurement of the 58Ni(n,α)55Fe reaction

    International Nuclear Information System (INIS)

    Ketlerov, V.V.; Goverdovskij, A.A.; Mitrofanov, V.F.; Ostapenko, Yu.B.; Khryachkov, V.A.

    1997-01-01

    Results of the measurement of the 58 Ni(n,α) 55 Fe reaction in the 3.5 - 6.8 MeV energy range is presented. The measurements were performed using a gridded ionization chamber with a gas mixture of 95% Xe and 3% CO 2 . The corrections made to the experimental data, which took a large number of factors into account, are presented. The nature of the measured cross-section uncertainties are discussed, and the results are compared with the data of other authors. (author). 9 refs, 2 figs

  8. Measurement of (n,Xn) reaction cross sections at 96 MeV

    International Nuclear Information System (INIS)

    Sagrado Garcia, Melle Inmaculada C.

    2006-10-01

    Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n,Xn) reactions in this energy range. Neutron double differential cross section measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL Laboratory in Uppsala, Sweden. The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 angle - 98 angle). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100) MeV. The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparison between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its treatment of nucleon-nucleon reactions. (author)

  9. Relation of expansion due to alkali silica reaction to the degree of reaction measured by SEM image analysis

    International Nuclear Information System (INIS)

    Haha, M. Ben; Gallucci, E.; Guidoum, A.; Scrivener, K.L.

    2007-01-01

    Scanning Electron Microscopy Image Analysis (SEM-IA) was used to quantify the degree of alkali silica reaction in affected microbars, mortar and concrete prisms. It was found that the degree of reaction gave a unique correlation with the macroscopic expansion for three different aggregates, stored at three temperatures and with two levels of alkali. The relationships found for the concretes and the mortars overlap when normalised by the aggregate content. This relationship seems to be linear up to a critical reaction degree which coincides with crack initiation within the reactive aggregates

  10. Measurement of dabigatran: previously demonstrated Hemoclot®Thrombin Inhibitor assay reagent instability on Sysmex CS-2100i is no longer an issue.

    Science.gov (United States)

    Comuth, Willemijn J; Faaborg, Louise; Henriksen, Linda Ø; Münster, Anna-Marie B

    The Hemoclot ® Thrombin Inhibitor (HTI) assay has been recommended for measurement of dabigatran concentrations in specific clinical situations. Traditionally, reagents for biochemical assays are prepared from instructions found in the package insert. For the HTI reagents the manufacturer recommends incubating the reagents much longer than indicated in the package insert. These recommendations are added to the application sheets designed for different analyzers. Many clinicians and laboratory personnel may be unaware of the discrepancy between the two instructions, resulting in incorrect handling of the reagents. The aim of this study was to investigate the effect of the two different preparation methods on reagent stability and test results. For the standard concentration range, reagent stability on Sysmex CS-2100i was only two hours instead of the eight hours indicated by the producer when following package insert instructions (incubation time: 15 min). Stability was increased to five hours when following the application sheet (incubation time: 60 min). Two years later, the study was repeated using samples of patients treated with dabigatran etexilate. This time, reagent stability was at least six hours. Since the reagent composition was unchanged, the increased stability could be due to changed logistics by the supplier, with stock and transfer closer by. Previously demonstrated HTI reagent instability is no longer an issue at our laboratory. The reliability of results of clinical studies in which the assay has been used is potentially compromised.

  11. Light particle emission measurements in heavy ion reactions: Progress report, June 1, 1986-May 31, 1987

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1987-01-01

    During the past year we have completed our work on neutron emission in coincidence with fission fragments from the 158 Er system. In addition to this we have completed preliminary analysis of our results on neutron emission from products of damped reactions between 58 Ni and 165 Ho at 930 MeV. Two experiments were planned for the present contract period as discussed in our proposal for 1986-87. One of these, to measure the mass and charge distributions from projectile-like fragments (PLF) in the reactions 58 Ni + 165 Ho and 58 Ni + 58 Ni using the time-of-flight facility at the HHIRF has been successfully completed. The other, to measure momentum correlations between neutrons and charged particles produced in central collisions between 32 S + 197 Au is scheduled to be run in mid-February. 14 refs., 4 figs

  12. Lifetime and g-factor measurements of excited states using Coulomb excitation and alpha transfer reactions

    Energy Technology Data Exchange (ETDEWEB)

    Guevara, Z. E., E-mail: zjguevaram@unal.edu.co; Torres, D. A., E-mail: datorresg@unal.edu.co [Physics Department, Universidad Nacional de Colombia, Bogotá D.C. (Colombia)

    2016-07-07

    In this contribution the challenges in the use of a setup to simultaneously measure lifetimes and g-factor values will be presented. The simultaneous use of the transient field technique and the Doppler Shift Attenuation Method, to measure magnetic moments and lifetimes respectively, allows to obtain a complete characterization of the currents of nucleons and the deformation in excited states close to the ground state. The technique is at the moment limited to Coulomb excitation and alpha-transfer reactions, what opens an interesting perspective to consider this type of experiments with radioactive beams. The use of deep-inelastic and fusion-evaporation reactions will be discussed. An example of a setup that makes use of a beam of {sup 106}Cd to study excited states of {sup 110}Sn and the beam nuclei itself will be presented.

  13. Reaction rate distribution measurement and the core performance evaluation in the prototype FBR Monju

    Energy Technology Data Exchange (ETDEWEB)

    Usami, S.; Suzuoki, Z.; Deshimaru, T. [Monju Construction Office, Japan Nuclear Cycle Development Institute, Fukui-ken (Japan); Nakashima, F. [Tsuruga head Office, Japan Nuclear Cycle Development Institute, Fukui-ken (Japan)

    2001-07-01

    Monju is a prototype fast breeder reactor designed to have an output of 280 MW (714 MWt), fueled with mixed oxides of plutonium and uranium and cooled by liquid sodium. The principal data on plant design and performance are shown in Table 1. Monju attained initial criticality in April 1994 and the reactor physics tests were carried out from May through November 1994. The reaction rate distribution measurement by the foil activation method was one of these tests and was carried out in order to verify the core performance and to contribute to the development of the core design methods. On the basis of the reaction rate measurement data, the Monju initial core breeding ratio and the power distribution were evaluated. (author)

  14. An update on measurements of helium-production reactions with a spallation neutron source

    International Nuclear Information System (INIS)

    Haight, R.C.; Bateman, F.B.; Chadwick, M.B.

    1995-01-01

    This report gives the status, updated since the last Research Coordination Meeting, of alpha-particle production cross sections, emission spectra and angular distributions which we are measuring at the spallation source of fast neutrons at the Los Alamos Meson Physics Facility (LAMPF). Detectors at angles of 30, 60, 90 and 135 degrees are used to identify alpha particles, measure their energy spectra, and indicate the time-of-flight, and hence the energy, of the neutrons inducing the reaction. The useful neutron energy ranges from less than 1 MeV to approximately 50 MeV for the present experimental setup. Targets under study at present include C, N, 0, 27 Al, Si, 51 V, 56 Fe, 59 CO, 58,60 Ni, 89 Y and 93 Nb. Data for 59 Co have been re-analyzed. The results illustrate the capabilities of the approach, agreement with literature values, and comparisons with nuclear reaction model calculations

  15. Assessing the interpersonal transaction cycle: convergence of action and reaction interpersonal circumplex measures.

    Science.gov (United States)

    Wagner, C C; Kiesler, D J; Schmidt, J A

    1995-11-01

    Contemporary interpersonal theory uses 2 models to represent the process and content of interpersonal transactions. The interpersonal transaction cycle is a dynamic model demonstrating the interaction between the overt behaviors and the covert intrapsychic experiences of 2 interacting individuals in action-reaction event chains. The interpersonal circle is a static model codifying individual differences across various interpersonal content domains (e.g., traits, acts, problems, impacts). The present study used 150 pairs of undergraduates to demonstrate cross-observer structural convergence of 2 separate interpersonal circumplex inventories measuring the "action" and "reaction" components of the transaction cycle, providing evidence that both components of the cycle can be captured by existing circumplex measures, and allowing researchers to proceed on to more comprehensive tests of interpersonal theory.

  16. Reaction rate distribution measurement and the core performance evaluation in the prototype FBR Monju

    International Nuclear Information System (INIS)

    Usami, S.; Suzuoki, Z.; Deshimaru, T.; Nakashima, F.

    2001-01-01

    Monju is a prototype fast breeder reactor designed to have an output of 280 MW (714 MWt), fueled with mixed oxides of plutonium and uranium and cooled by liquid sodium. The principal data on plant design and performance are shown in Table 1. Monju attained initial criticality in April 1994 and the reactor physics tests were carried out from May through November 1994. The reaction rate distribution measurement by the foil activation method was one of these tests and was carried out in order to verify the core performance and to contribute to the development of the core design methods. On the basis of the reaction rate measurement data, the Monju initial core breeding ratio and the power distribution were evaluated. (author)

  17. Measuring the Electrode Kinetics of Surface Confined Electrode Reactions at a Constant Scan Rate

    OpenAIRE

    Guziejewski, Dariusz; Mirceski, Valentin; Jadresko, Dijana

    2014-01-01

    Abstract: The kinetics of surface confined electrode reactions of alizarin, vitamin B12, and vitamin K2 is measured with square-wave voltammetry over a wide pH interval, by applying the recent methodology for kinetic analysis at a constant scan rate [V. Mirceski, D. Guziejewski, K. Lisichkov, Electrochim. Acta 2013, 114, 667–673]. The reliability and the simplicity of the recent methodology is confirmed. The methodology requires analysis of the peak potential separation o...

  18. Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Nickel

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method covers procedures for measuring reaction rates by the activation reaction 58Ni(n,p)58Co. 1.2 This activation reaction is useful for measuring neutrons with energies above approximately 2.1 MeV and for irradiation times up to about 200 days in the absence of high thermal neutron fluence rates (for longer irradiations, see Practice E 261). 1.3 With suitable techniques fission-neutron fluence rates densities above 107 cm−2·s−1 can be determined. 1.4 Detailed procedures for other fast-neutron detectors are referenced in Practice E 261. 1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Note—The burnup corrections were com...

  19. Measurement of 240Pu Angular Momentum Dependent Fission Probabilities Using the (α ,α') Reaction

    Science.gov (United States)

    Koglin, Johnathon; Burke, Jason; Fisher, Scott; Jovanovic, Igor

    2017-09-01

    The surrogate reaction method often lacks the theoretical framework and necessary experimental data to constrain models especially when rectifying differences between angular momentum state differences between the desired and surrogate reaction. In this work, dual arrays of silicon telescope particle identification detectors and photovoltaic (solar) cell fission fragment detectors have been used to measure the fission probability of the 240Pu(α ,α' f) reaction - a surrogate for the 239Pu(n , f) - and fission fragment angular distributions. Fission probability measurements were performed at a beam energy of 35.9(2) MeV at eleven scattering angles from 40° to 140°e in 10° intervals and at nuclear excitation energies up to 16 MeV. Fission fragment angular distributions were measured in six bins from 4.5 MeV to 8.0 MeV and fit to expected distributions dependent on the vibrational and rotational excitations at the saddle point. In this way, the contributions to the total fission probability from specific states of K angular momentum projection on the symmetry axis are extracted. A sizable data collection is presented to be considered when constraining microscopic cross section calculations.

  20. Cross Section Measurements of the Reaction 23Na(p, γ)24Mg

    Science.gov (United States)

    Boeltzig, Axel; Deboer, Richard James; Macon, Kevin; Wiescher, Michael; Best, Andreas; Imbriani, Gianluca; Gyürky, György; Strieder, Frank

    2017-09-01

    The reaction 23Na(p, γ)24Mg can provide a link from the NeNa to the MgAl cycle in stellar burning and is therefore of interest in nuclear astrophysics. To determine the reaction rates at stellar temperatures, new cross section measurements at low proton energies have been performed recently, and further experiments are underway. The current cross section data implies that the reaction rate up to temperatures of 1 GK is determined by a few narrow resonances and direct capture. Complementary to these experimental efforts at low proton energies, cross section measurements at higher energies can help to constrain the direct capture and broad resonance contributions to the cross section and reduce the uncertainty of the extrapolation towards stellar energies. In this paper we report an experiment to measure the 23Na(p, γ)24Mg cross section with a solid target setup at the St. ANA 5U accelerator at the University of Notre Dame. The experiment and the current status of data analysis will be described. This work benefited from support by the National Science Foundation under Grant No. PHY-1430152 (JINA-CEE), the Nuclear Science Laboratory (NSL), the Istituto Nazionale di Fisica Nucleare (INFN), and the Gran Sasso Science Institute (GSSI).

  1. Differential cross section and recoil polarization measurements for the gamma p to K+ Lambda reaction using CLAS at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    McCracken, Michael E. [Carnegie Mellon Univ., Pittsburgh, PA (United States)

    2010-02-01

    We present measurements of the differential cross section and Lambda recoil polarization for the gamma p to K+ Lambda reaction made using the CLAS detector at Jefferson Lab. These measurements cover the center-of-mass energy range from 1.62 to 2.84 GeV and a wide range of center-of-mass K+ production angles. Independent analyses were performed using the K+ p pi- and K+ p (missing pi -) final-state topologies; results from these analyses were found to exhibit good agreement. These differential cross section measurements show excellent agreement with previous CLAS and LEPS results and offer increased precision and a 300 MeV increase in energy coverage. The recoil polarization data agree well with previous results and offer a large increase in precision and a 500 MeV extension in energy range. The increased center-of-mass energy range that these data represent will allow for independent study of non-resonant K+ Lambda photoproduction mechanisms at all production angles.

  2. Simultaneous measurement of anisotropic solute diffusivity and binding reaction rates in biological tissues by FRAP.

    Science.gov (United States)

    Travascio, Francesco; Gu, Wei Yong

    2011-01-01

    Several solutes (e.g., growth factors, cationic solutes, etc.) can reversibly bind to the extracellular matrix (ECM) of biological tissues. Binding interactions have significant implications on transport of such solutes through the ECM. In order to fully delineate transport phenomena in biological tissues, knowledge of binding kinetics is crucial. In this study, a new method for the simultaneous determination of solute anisotropic diffusivity and binding reaction rates was presented. The new technique was solely based on Fourier analysis of fluorescence recovery after photobleaching (FRAP) images. Computer-simulated FRAP tests were used to assess the sensitivity and the robustness of the method to experimental parameters, such as anisotropic solute diffusivity and rates of binding reaction. The new method was applied to the determination of diffusivity and binding rates of 5-dodecanoylaminofluorescein (DAF) in bovine coccygeal annulus fibrosus (AF). Our findings indicate that DAF reversibly binds to the ECM of AF. In addition, it was found that DAF diffusion in AF is anisotropic. The results were in agreement with those reported in previous studies. This study provides a new tool for the simultaneous determination of solute anisotropic diffusion tensor and rates of binding reaction that can be used to investigate diffusive-reactive transport in biological tissues and tissue engineered constructs.

  3. Measurement of isotopic cross sections of the fission fragments produced in 500 AMeV 208Pb + p reaction

    International Nuclear Information System (INIS)

    Fernandez-Dominguez, B.

    2003-03-01

    The aim of this work is the study of the fission fragments produced in the spallation reaction 208 Pb + p at 500 AMeV. The fission fragments from Z=23 up to Z=59 have been detected and identified by using the inverse kinematics technique with the high-resolution spectrometer FRS. The production cross sections and the recoil velocities of 430 nuclei have been measured. The measured data have been compared with previous data. The isotopic distributions show a high precision. However, the absolute value of the fission cross section is higher than expected. From the experimental data the characteristics of the average fissioning system have been reconstructed (Z fis , A fis , E* fis ). In addition, the number of post-fission neutrons emitted from the fission fragments, v post , has been determined by using a new method. The experimental data have been compared to the two-steps models describing the spallation reaction. The impact of the model parameters on the observables has been analysed and the reasons Leading to the observed differences between the codes are also presented. This analyse shows a good agreement with the INCL4+ABLA code. (author)

  4. Standard Test Method for Measuring Reaction Rates by Analysis of Barium-140 From Fission Dosimeters

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This test method describes two procedures for the measurement of reaction rates by determining the amount of the fission product 140Ba produced by the non-threshold reactions 235U(n,f), 241Am(n,f), and 239Pu(n,f), and by the threshold reactions 238U(n,f), 237Np(n,f), and 232Th(n,f). 1.2 These reactions produce many fission products, among which is 140Ba, having a half-life of 12.752 days. 140Ba emits gamma rays of several energies; however, these are not easily detected in the presence of other fission products. Competing activity from other fission products requires that a chemical separation be employed or that the 140Ba activity be determined indirectly by counting its daughter product 140La. This test method describes both procedure (a), the nondestructive determination of 140Ba by the direct counting of 140La several days after irradiation, and procedure (b), the chemical separation of 140Ba and the subsequent counting of 140Ba or its daughter 140La. 1.3 With suitable techniques, fission neutron fl...

  5. Fusion measurements for the {}^{18}O+{}^{194}{Pt} reaction and search for neutron shell closure effects

    Science.gov (United States)

    Laveen, P. V.; Prasad, E.; Madhavan, N.; Pal, S.; Sadhukhan, J.; Nath, S.; Gehlot, J.; Jhingan, A.; Varier, K. M.; Thomas, R. G.; Vinodkumar, A. M.; Shamlath, A.; Varughese, T.; Sugathan, P.; Babu, B. R. S.; Appannababu, S.; Golda, K. S.; Behera, B. R.; Singh, Varinderjit; Sandal, Rohit; Saxena, A.; John, B. V.; Kailas, S.

    2015-09-01

    Evaporation residue (ER) and fission cross sections were measured for the reaction {}18O+{}194{Pt} forming the compound nucleus 212Rn. Fission fragment angular distributions and anisotropies are consistent with the saddle point model predictions. Measured ER cross sections were fitted with statistical model calculations assuming shell-corrected free energy fission barrier height. The non-zero dissipation strength required to fit the ER cross section supports the dissipative nature of fission dynamics in heavy ion fusion. In the present study shell closure effects are not observed in the dissipation strength.

  6. Measurement of the 3He(e,e'p)pn Reaction at High Missing Energies and Momenta

    Energy Technology Data Exchange (ETDEWEB)

    Benmokhtar, Fatiha [Rutgers Univ., New Brunswick, NJ (United States)

    2004-10-01

    We investigate the structure of 3He through the measurement of quasielastic 3He(e,e'). The measurements use the high duty factor electron beam and the high-precision two-spectrometer system in Hall A of the Thomas Jefferson National Accelerator Facility (TJNAF). The measurements were performed in perpendicular kinematics at fixed momentum and energy transfer by the electron, |$\\vec{q}$|= 1.5 GeV/c and omega = 837 MeV, respectively. A description of the reaction in the plane wave impulse approximation is presented. The experimental equipment is described in detail. For the measurements, the kinematics of the experiment are given. The procedures to remove backgrounds and perform radiative corrections, are also discussed in detail. The detailed method of performing radiative corrections in particular is novel to this work. Finally, the resulting cross sections, distorted spectral functions, and asymmetry ATL are presented, and the physics implications are discussed. We extracted cross sections and distorted spectral functions up to high missing momentum, pm up to 1 GeV/c, and up to high missing energies, Em up to 140 MeV, the pion production threshold. The experimental data are much higher in statistics and much more extensive in kinematic coverage than any previous measurement. Theoretical predictions are in good agreement with the data, leading to the conclusion that the cross section at large missing momenta is strongly enhanced by nucleon-nucleon correlations, with additional enhancement from final-state interactions. The conventional NN correlations present in a modern three-body nuclear wave function, along with a modern reaction mechanism theory, appear sufficient to explain the data; there is no strong indication of a need to include any additional exotic physics, such as quark degrees of freedom.

  7. Measurement of the $^{44}$Ti($\\alpha$,p)$^{47}$V reaction cross section, of relevance to $\\gamma$-ray observation of core collapse supernovae, using reclaimed $^{44}$Ti

    CERN Multimedia

    Despite decades of research, fundamental uncertainties remain in the underlying explosion mechanism of core collapse supernovae. One of the most direct methods that might help resolve this problem is a comparison of the predicted to the observed flux of $\\gamma$-rays due to decay of $^{44}$Ti produced in the explosion, as it is believed this could reveal the location of the mass cut, a key hydrodynamical property of the explosion. Such a study is at present limited by the uncertainty in the $^{44}$Ti($\\alpha$,p)$^{47}$V reaction rate. In this experiment we propose to measure the cross section for this reaction at astrophysically relevant energies. The single previous measurement of this reaction was limited to higher energies due to low beam intensities. Here, a more intense beam will be employed, generated from $^{44}$Ti reclaimed as part of the ERAWAST project at PSI.

  8. Estimation of (n,f) Cross-Sections by Measuring Reaction Probability Ratios

    Energy Technology Data Exchange (ETDEWEB)

    Plettner, C; Ai, H; Beausang, C W; Bernstein, L A; Ahle, L; Amro, H; Babilon, M; Burke, J T; Caggiano, J A; Casten, R F; Church, J A; Cooper, J R; Crider, B; Gurdal, G; Heinz, A; McCutchan, E A; Moody, K; Punyon, J A; Qian, J; Ressler, J J; Schiller, A; Williams, E; Younes, W

    2005-04-21

    Neutron-induced reaction cross-sections on unstable nuclei are inherently difficult to measure due to target activity and the low intensity of neutron beams. In an alternative approach, named the 'surrogate' technique, one measures the decay probability of the same compound nucleus produced using a stable beam on a stable target to estimate the neutron-induced reaction cross-section. As an extension of the surrogate method, in this paper they introduce a new technique of measuring the fission probabilities of two different compound nuclei as a ratio, which has the advantage of removing most of the systematic uncertainties. This method was benchmarked in this report by measuring the probability of deuteron-induced fission events in coincidence with protons, and forming the ratio P({sup 236}U(d,pf))/P({sup 238}U(d,pf)), which serves as a surrogate for the known cross-section ratio of {sup 236}U(n,f)/{sup 238}U(n,f). IN addition, the P({sup 238}U(d,d{prime}f))/P({sup 236}U(d,d{prime}f)) ratio as a surrogate for the {sup 237}U(n,f)/{sup 235}U(n,f) cross-section ratio was measured for the first time in an unprecedented range of excitation energies.

  9. Neutron capture cross section measurements and theoretical calculation for the {sup 186}W(n,γ){sup 187}W reaction

    Energy Technology Data Exchange (ETDEWEB)

    Al-abyad, Mogahed; Mohamed, Gehan Y. [Atomic Energy Authority, Cairo (Egypt). Experimental Nuclear Physics Dept.

    2017-08-01

    Neutron capture cross section (σ{sub 0}) and resonance integral (I{sub 0}) of the reaction {sup 186}W(n,γ){sup 187}W were measured experimentally using the research reactor (ETRR-2) and an Am-Be neutron source, also calculated using TALYS-1.6 code. The present results of σ{sub 0} are (39.08±2.6, 38.75±0.98 and 38.33 barn) and I{sub 0} are (418.5±74, 439.3±36 and 445.5 barn) by using the reactor, neutron source and TALYS-1.6, respectively. The present results are in acceptable agreement with most of the previous experimental and evaluated data as well as the theoretical calculations.

  10. New Improved Indirect Measurement of the {sup 19}F( p , α ){sup 16}O Reaction at Energies of Astrophysical Relevance

    Energy Technology Data Exchange (ETDEWEB)

    Indelicato, I.; La Cognata, M.; Spitaleri, C.; Cherubini, S.; Gulino, M.; Lamia, L.; Pizzone, R. G.; Romano, S.; Tumino, A. [INFN, Laboratori Nazionali del Sud, Catania (Italy); Burjan, V.; Hons, Z.; Kroha, V.; Mrazek, J. [Nuclear Physics Institute of ASCR, Rez near Prague (Czech Republic); Hayakawa, S. [RIKEN, CNS, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Mazzocco, M.; Strano, E.; Torresi, D., E-mail: indelicato@lns.infn.it [INFN, Sezione di Padova, Padova (Italy)

    2017-08-10

    Fluorine abundance determination is of great importance in stellar physics to understand s-elements production and mixing processes in asymptotic giant branch (AGB) stars. Up to now, theoretical models overproduce F abundances in AGB stars with respect to the observed values, thus calling for further investigation of the reactions involving fluorine. In particular, the {sup 19}F( p , α ){sup 16}O reaction is the main destruction channel of fluorine at the bottom of the convective envelope in AGB stars, an H-rich environment where it can experience temperatures high enough to determine its destruction, owing to additional mixing processes. In this paper the Trojan horse method (THM) was used to extract the {sup 19}F( p , α {sub 0}){sup 16}O S-factor in the energy range of astrophysical interest ( E {sub cm} ≈ 0–1 MeV). This is the most relevant channel at the low temperatures (few 10{sup 7} K) characterizing the bottom of the convective envelope, according to current knowledge. A previous indirect experiment using the THM has observed three resonances in the energy regions below E {sub cm} ≈ 450 keV. These energies correspond to typical AGB temperatures, thus implying a significant increase in the reaction rate. Statistics are scarce for performing an accurate separation between resonances, preventing one from drawing a quantitative conclusion about their total widths and spin parities. Before THM measurement, only extrapolations were available below about 500 keV, showing a non-resonant behavior that sharply contradicts the trend of the astrophysical factor at higher energies. A new experiment has been performed to verify the measured TH astrophysical factor and to perform more accurate spectroscopy of the involved resonances.

  11. Measurement of activation cross sections of the proton induced nuclear reactions on palladium

    International Nuclear Information System (INIS)

    Ditroi, F.; Tarkanyi, F.; Takacs, S.; Mahunka, I.; Csikai, J.; Hermanne, A.; Uddin, M.S.; Hagiwara, M.; Baba, M.; Ido, T.

    2007-01-01

    Excitation functions of proton induced reactions on Pd are important for medical radioisotope production, for activation analysis, for development of low activation materials and other purposes. No experimental data exist in the literature for low and medium energy range protons. A detailed study of the excitation functions was performed up to 80 MeV proton energy by using the stacked foil irradiation technique and gamma-ray spectrometry. The irradiations were carried out at the external beam lines of the AVF cyclotron at the Tohoku University, Japan (80 and 70 MeV) and the CGR 560 cyclotron at the Vrije Universiteit Brussels (38, 29 and 17 MeV). The beam intensity, the incident energy and the energy degradation were controlled by a method based on flux constancy via normalization to the parallel measured excitation functions of nat Al(p,x) 22,24 Na and nat Cu(p,x) 56,58 Co, 62,65 Zn monitor reactions. Excitation functions for direct and cumulative cross sections have been measured for the production of 105mg,106m,110m Ag, 101 Pd, 101 mRh and 97 Ru radionuclei. Calculations for the excitation functions using the Alice-IPPE code were performed with a view to estimate the weight of the different contributing reactions and to check the trend and the magnitude of the obtained experimental data. (author)

  12. Measurements of neutron-induced reactions in inverse kinematics and applications to nuclear astrophysics

    Directory of Open Access Journals (Sweden)

    Reifarth René

    2015-01-01

    Full Text Available Neutron capture cross sections of unstable isotopes are important for neutron-induced nucleosynthesis as well as for technological applications. A combination of a radioactive beam facility, an ion storage ring and a high flux reactor would allow a direct measurement of neutron induced reactions over a wide energy range on isotopes with half lives down to minutes. The idea is to measure neutron-induced reactions on radioactive ions in inverse kinematics. This means, the radioactive ions will pass through a neutron target. In order to efficiently use the rare nuclides as well as to enhance the luminosity, the exotic nuclides can be stored in an ion storage ring. The neutron target can be the core of a research reactor, where one of the central fuel elements is replaced by the evacuated beam pipe of the storage ring. Using particle detectors and Schottky spectroscopy, most of the important neutron-induced reactions, such as (n,γ, (n,p, (n,α, (n,2n, or (n,f, could be investigated.

  13. Exclusive Measurements of Breakup Reactions in the 7Li+144Sm System

    International Nuclear Information System (INIS)

    Heimann, D. Martinez; Pacheco, A. J.; Arazi, A.; Figueira, J. M.; Negri, A.; Capurro, O. A.; Carnelli, P.; Fimiani, L.; Grinberg, P.; Marti, G. V.; Testoni, J. E.; Monteiro, D. S.; Niello, J. O. Fernandez; Marta, H. D.

    2009-01-01

    Breakup reactions induced by a 30 MeV 7 Li beam on a 144 Sm target were measured through the coincident detection of the light particles emitted in the reaction plane. The emphasis of the measurements and data analysis was placed in the complete characterization of the reaction by means of the identification of the breakup products and the experimental extraction of the physically relevant magnitudes. The coincident yield of the emitted light particles was compared with the results of kinematical calculations that were done assuming different distributions for these magnitudes and taking into account the geometric response of the detection system. The results of this comparison indicate in all cases a clear dominance of a process compatible with the breakup of 6 Li through the 3 + resonant state at 2.186 MeV following one-neutron transfer from the projectile to the target, over the breakup of the projectile itself. Relative cross sections as a function of the emission angle of the 6 Li and the in-plane anisotropy of the subsequent emission of breakup products were extracted from the data.

  14. Characterizing Information Processing With a Mobile Device: Measurement of Simple and Choice Reaction Time.

    Science.gov (United States)

    Burke, Daniel; Linder, Susan; Hirsch, Joshua; Dey, Tanujit; Kana, Daniel; Ringenbach, Shannon; Schindler, David; Alberts, Jay

    2017-10-01

    Information processing is typically evaluated using simple reaction time (SRT) and choice reaction time (CRT) paradigms in which a specific response is initiated following a given stimulus. The measurement of reaction time (RT) has evolved from monitoring the timing of mechanical switches to computerized paradigms. The proliferation of mobile devices with touch screens makes them a natural next technological approach to assess information processing. The aims of this study were to determine the validity and reliability of using of a mobile device (Apple iPad or iTouch) to accurately measure RT. Sixty healthy young adults completed SRT and CRT tasks using a traditional test platform and mobile platforms on two occasions. The SRT was similar across test modality: 300, 287, and 280 milliseconds (ms) for the traditional, iPad, and iTouch, respectively. The CRT was similar within mobile devices, though slightly faster on the traditional: 359, 408, and 384 ms for traditional, iPad, and iTouch, respectively. Intraclass correlation coefficients ranged from 0.79 to 0.85 for SRT and from 0.75 to 0.83 for CRT. The similarity and reliability of SRT across platforms and consistency of SRT and CRT across test conditions indicate that mobile devices provide the next generation of assessment platforms for information processing.

  15. Elementary reaction rate measurements at high temperatures by tunable-laser flash-absorption

    Energy Technology Data Exchange (ETDEWEB)

    Hessler, J.P. [Argonne National Laboratory, IL (United States)

    1993-12-01

    The major objective of this program is to measure thermal rate coefficients and branching ratios of elementary reactions. To perform these measurements, the authors constructed an ultrahigh-purity shock tube to generate temperatures between 1000 and 5500 K. The tunable-laser flash-absorption technique is used to measure the rate of change of the concentration of species which absorb below 50,000 cm{sup {minus}1} e.g.: OH, CH, and CH{sub 3}. This technique is being extended into the vacuum-ultraviolet spectral region where one can measure atomic species e.g.: H, D, C, O, and N; and diatomic species e.g.: O{sub 2}, CO, and OH.

  16. Measurement of 17F(d ,n )18Ne and the impact on the 17F(p ,γ )18Ne reaction rate for astrophysics

    Science.gov (United States)

    Kuvin, S. A.; Belarge, J.; Baby, L. T.; Baker, J.; Wiedenhöver, I.; Höflich, P.; Volya, A.; Blackmon, J. C.; Deibel, C. M.; Gardiner, H. E.; Lai, J.; Linhardt, L. E.; Macon, K. T.; Rasco, B. C.; Quails, N.; Colbert, K.; Gay, D. L.; Keeley, N.

    2017-10-01

    Background: The 17F(p ,γ )18Ne reaction is part of the astrophysical "hot CNO" cycles that are important in astrophysical environments like novas. Its thermal reaction rate is low owing to the relatively high energy of the resonances and therefore is dominated by direct, nonresonant capture in stellar environments at temperatures below 0.4 GK. Purpose: An experimental method is established to extract the proton strength to bound and unbound states in experiments with radioactive ion beams and to determine the parameters of direct and resonant capture in the 17F(p ,γ )18Ne reaction. Method: The 17F(d ,n )18Ne reaction is measured in inverse kinematics using a beam of the short-lived isotope 17F and a compact setup of neutron, proton, γ -ray, and heavy-ion detectors called resoneut. Results: The spectroscopic factors for the lowest l =0 proton resonances at Ec .m .=0.60 and 1.17 MeV are determined, yielding results consistent within 1.4 σ of previous proton elastic-scattering measurements. The asymptotic normalization coefficients of the bound 21+ and 22+ states in 18Ne are determined and the resulting direct-capture reaction rates are extracted. Conclusions: The direct-capture component of the 17F(p ,γ )18Ne reaction is determined for the first time from experimental data on 18Ne.

  17. New Measurement of the 25Mg(n,γ) Reaction Cross Section

    CERN Document Server

    Massimi, C; Mingrone, F; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Bečvář, F; Belloni, F; Berthoumieux, E; Billowes, J; Bosnar, D; Brugger, M; Calviani, M; Calviño, F; Cano-Ott, D; Carrapiço, C; Cerutti, F; Chiaveri, E; Chin, M; Colonna, N; Cortés, G; Cortés-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dressler, R; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; García, A R; Giubrone, G; Gonçalves, I F; González-Romero, E; Griesmayer, E; Guerrero, C; Gunsing, F; Hernández-Prieto, A; Jenkins, D G; Jericha, E; Kadi, Y; Käppeler, F; Karadimos, D; Kivel, N; Krtička, M; Kroll, J; Lampoudis, C; Langer, C; Leal-Cidoncha, E; Lederer, C; Leeb, H; Leong, L S; Losito, R; Mallick, A; Manousos, A; Marganiec, J; Martínez, T; Mastinu, P F; Mastromarco, M; Mendoza, E; Mengoni, A; Milazzo, P M; Mirea, M; Mondalaers, W; Paradela, C; Pavlik, A; Perkowski, J; Plompen, A; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Robles, M S; Rubbia, C; Sabaté-Gilarte, M; Sarmento, R; Saxena, A; Schillebeeckx, P; Schmidt, S; Schumann, D; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Tsinganis, A; Valenta, S.; Vannini, G; Variale, V; Vaz, P; Ventura, A; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiß, C; Wright, T; Žugec, P

    2014-01-01

    Aim at addressing important astrophysical issues related to the s process. Highly-enriched Mg-25 samples have been used, in the form of MgO powder and Mg metal sample. Preliminary results from the 2012 measurement and comparisons with previous data are shown.

  18. Nuclear reaction measurements on tissue-equivalent materials and GEANT4 Monte Carlo simulations for hadrontherapy

    Science.gov (United States)

    De Napoli, M.; Romano, F.; D'Urso, D.; Licciardello, T.; Agodi, C.; Candiano, G.; Cappuzzello, F.; Cirrone, G. A. P.; Cuttone, G.; Musumarra, A.; Pandola, L.; Scuderi, V.

    2014-12-01

    When a carbon beam interacts with human tissues, many secondary fragments are produced into the tumor region and the surrounding healthy tissues. Therefore, in hadrontherapy precise dose calculations require Monte Carlo tools equipped with complex nuclear reaction models. To get realistic predictions, however, simulation codes must be validated against experimental results; the wider the dataset is, the more the models are finely tuned. Since no fragmentation data for tissue-equivalent materials at Fermi energies are available in literature, we measured secondary fragments produced by the interaction of a 55.6 MeV u-1 12C beam with thick muscle and cortical bone targets. Three reaction models used by the Geant4 Monte Carlo code, the Binary Light Ions Cascade, the Quantum Molecular Dynamic and the Liege Intranuclear Cascade, have been benchmarked against the collected data. In this work we present the experimental results and we discuss the predictive power of the above mentioned models.

  19. Material interactions with the Low Earth Orbital (LEO) environment: Accurate reaction rate measurements

    Science.gov (United States)

    Visentine, James T.; Leger, Lubert J.

    1987-01-01

    To resolve uncertainties in estimated LEO atomic oxygen fluence and provide reaction product composition data for comparison to data obtained in ground-based simulation laboratories, a flight experiment has been proposed for the space shuttle which utilizes an ion-neutral mass spectrometer to obtain in-situ ambient density measurements and identify reaction products from modeled polymers exposed to the atomic oxygen environment. An overview of this experiment is presented and the methodology of calibrating the flight mass spectrometer in a neutral beam facility prior to its use on the space shuttle is established. The experiment, designated EOIM-3 (Evaluation of Oxygen Interactions with Materials, third series), will provide a reliable materials interaction data base for future spacecraft design and will furnish insight into the basic chemical mechanisms leading to atomic oxygen interactions with surfaces.

  20. Association of single nucleotide polymorphisms in candidate genes previously related to genetic variation in fertility with phenotypic measurements of reproductive function in Holstein cows.

    Science.gov (United States)

    Ortega, M Sofia; Denicol, Anna C; Cole, John B; Null, Daniel J; Taylor, Jeremy F; Schnabel, Robert D; Hansen, Peter J

    2017-05-01

    Many genetic markers related to health or production traits are not evaluated in populations independent of the discovery population or related to phenotype. Here we evaluated 68 single nucleotide polymorphisms (SNP) in candidate genes previously associated with genetic merit for fertility and production traits for association with phenotypic measurements of fertility in a population of Holstein cows that was selected based on predicted transmitting ability (PTA) for daughter pregnancy rate (DPR; high, ≥1, n = 989; low, ≤ -1.0, n = 1,285). Cows with a high PTA for DPR had higher pregnancy rate at first service, fewer services per conception, and fewer days open than cows with a low PTA for DPR. Of the 68 SNP, 11 were associated with pregnancy rate at first service, 16 with services per conception, and 19 with days open. Single nucleotide polymorphisms in 12 genes (BDH2, BSP3, CAST, CD2, CD14, FUT1, FYB, GCNT3, HSD17B7, IBSP, OCLN, and PCCB) had significant associations with 2 fertility traits, and SNP in 4 genes (CSPP1, FCER1G, PMM2, and TBC1D24) had significant associations with each of the 3 traits. Results from this experiment were compared with results from 2 earlier studies in which the SNP were associated with genetic estimates of fertility. One study involved the same animals as used here, and the other study was of an independent population of bulls. A total of 13 SNP associated with 1 or more phenotypic estimates of fertility were directionally associated with genetic estimates of fertility in the same cow population. Moreover, 14 SNP associated with reproductive phenotype were directionally associated with genetic estimates of fertility in the bull population. Nine SNP (located in BCAS, BSP3, CAST, FUT1, HSD17B7, OCLN, PCCB, PMM2, and TBC1D24) had a directional association with fertility in all 3 studies. Examination of the function of the genes with SNP associated with reproduction in more than one study indicates the importance of steroid hormones

  1. Cross section of α-induced reactions on iridium isotopes obtained from thick target yield measurement for the astrophysical γ process

    Science.gov (United States)

    Szücs, T.; Kiss, G. G.; Gyürky, Gy.; Halász, Z.; Fülöp, Zs.; Rauscher, T.

    2018-01-01

    The stellar reaction rates of radiative α-capture reactions on heavy isotopes are of crucial importance for the γ process network calculations. These rates are usually derived from statistical model calculations, which need to be validated, but the experimental database is very scarce. This paper presents the results of α-induced reaction cross section measurements on iridium isotopes carried out at first close to the astrophysically relevant energy region. Thick target yields of 191Ir(α,γ)195Au, 191Ir(α,n)194Au, 193Ir(α,n)196mAu, 193Ir(α,n)196Au reactions have been measured with the activation technique between Eα = 13.4 MeV and 17 MeV. For the first time the thick target yield was determined with X-ray counting. This led to a previously unprecedented sensitivity. From the measured thick target yields, reaction cross sections are derived and compared with statistical model calculations. The recently suggested energy-dependent modification of the α + nucleus optical potential gives a good description of the experimental data.

  2. Cross section of α-induced reactions on iridium isotopes obtained from thick target yield measurement for the astrophysical γ process

    Directory of Open Access Journals (Sweden)

    T. Szücs

    2018-01-01

    Full Text Available The stellar reaction rates of radiative α-capture reactions on heavy isotopes are of crucial importance for the γ process network calculations. These rates are usually derived from statistical model calculations, which need to be validated, but the experimental database is very scarce. This paper presents the results of α-induced reaction cross section measurements on iridium isotopes carried out at first close to the astrophysically relevant energy region. Thick target yields of 191Ir(α,γ195Au, 191Ir(α,n194Au, 193Ir(α,n196mAu, 193Ir(α,n196Au reactions have been measured with the activation technique between Eα=13.4 MeV and 17 MeV. For the first time the thick target yield was determined with X-ray counting. This led to a previously unprecedented sensitivity. From the measured thick target yields, reaction cross sections are derived and compared with statistical model calculations. The recently suggested energy-dependent modification of the α+nucleus optical potential gives a good description of the experimental data.

  3. PREVIOUS SECOND TRIMESTER ABORTION

    African Journals Online (AJOL)

    PNLC

    PREVIOUS SECOND TRIMESTER ABORTION: A risk factor for third trimester uterine rupture in three ... for accurate diagnosis of uterine rupture. KEY WORDS: Induced second trimester abortion - Previous uterine surgery - Uterine rupture. ..... scarred uterus during second trimester misoprostol- induced labour for a missed ...

  4. Measurement of excitation functions in alpha induced reactions on {sup nat}Cu

    Energy Technology Data Exchange (ETDEWEB)

    Shahid, Muhammad; Kim, Kwangsoo; Kim, Guinyun, E-mail: gnkim@knu.ac.kr; Zaman, Muhammad; Nadeem, Muhammad

    2015-09-01

    The excitation functions of {sup 66,67,68}Ga, {sup 62,63,65}Zn, {sup 61,64}Cu, and {sup 58,60}Co radionuclides in the {sup nat}Cu(α, x) reaction were measured in the energy range from 15 to 42 MeV by using a stacked-foil activation method at the MC-50 cyclotron of the Korean Institute of Radiological and Medical Sciences. The measured results were compared with the literature data as well as the theoretical values obtained from the TENDL-2013 and TENDL-2014 libraries based on the TALYS-1.6 code. The integral yields for thick targets of the produced radionuclides were also determined from the measured excitation functions and the stopping power of natural copper.

  5. First measurement of the helicity dependence for the {gamma}p{yields}p{pi} reaction

    Energy Technology Data Exchange (ETDEWEB)

    Ahrens, J.; Arends, H.J.; Beck, R.; Heid, E.; Jahn, O.; Jennewein, P.; Lang, M.; Martinez-Fabregate, M.; Rost, M.; Tamas, G.; Thomas, A. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Altieri, S.; Panzeri, A.; Pinelli, T. [INFN, Sezione di Pavia, Pavia (Italy); Universita di Pavia, Dipartimento di Fisica Nucleare e Teorica, Pavia (Italy); Annand, J.R.M.; McGeorge, J.C.; Rosner, G. [University of Glasgow, Department of Physics and Astronomy, Glasgow (United Kingdom); Blackston, M.A.; Weller, H.R. [Duke University, Department of Physics, Durham (United States); Bradtke, C.; Dutz, H.; Klein, F.; Rohlof, C. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Braghieri, A.; Pedroni, P. [INFN, Sezione di Pavia, Pavia (Italy); Hose, N. d' [CEA Saclay, DSM/DAPNIA/SPhN, Gif-sur-Yvette Cedex (France); Fix, A. [Tomsk Polytechnic University, Laboratory of Mathematical Physics, Tomsk (Russian Federation); Goertz, S.; Meyer, W.; Reicherz, G. [Ruhr-Universitaet Bochum, Insitut fuer Experimentalphysik, Bochum (Germany); Grabmayr, P. [Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Hasegawa, S.; Iwata, T. [Nagoya University, Department of Physics, Chikusa-ku, Nagoya (Japan); Holvoet, H.; Lannoy, B.; Ryckbosch, D.; Van de Vyver, R. [Universiteit Gent, Subatomaire en Stralingsfysica, Gent (Belgium); Horikawa, N. [Nagoya University, CIRSE, Chikusa-ku, Nagoya (Japan); Kondratiev, R.; Lisin, V. [Academy of Science, INR, Moscow (Russian Federation); Preobrajenski, I. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Academy of Science, INR, Moscow (Russian Federation); Rostomyan, T. [Universiteit Gent, Subatomaire en Stralingsfysica, Gent (Belgium); INFN, Sezione di Pavia, Pavia (Italy); Schumacher, M.; Seitz, B.; Zapadtka, F. [Universitaet Goettingen, II.Physikalisches Institut, Goettingen (Germany)

    2007-10-15

    The helicity dependence of the total cross-section and the invariant-mass distributions in the (p{pi}{sup {+-}}) and ({pi}{sup +}{pi}{sup -}) final states for the {gamma}p{yields}p{pi}{sup +}{pi}{sup -} reaction have been measured for the first time at incident photon energies from 400 to 800 MeV. The measurement was performed with the large-acceptance detector DAPHNE at the tagged photon beam facility of the MAMI accelerator in Mainz. Although this channel is found to be predominantly excited by the intermediate production of a {delta}{pi} state, both the measured unpolarized and the helicity-dependent observables are generally not well described by the existing theoretical models. (orig.)

  6. Threshold measurement of the {lambda}p {r_arrow} n{pi}+ reaction

    Energy Technology Data Exchange (ETDEWEB)

    Korkmaz, E.; O`Rielly, G.V.; Hutcheon, D.A. [and others

    1995-10-01

    Threshold photoproduction of pions off nucleons is one of a few low-energy phenomena for which QCD-based effective field theories can be formulated and tested. As part of a program aimed at determining the threshold amplitudes of the various {gamma}N {r_arrow} N{pi} channels, a cross section measurement of the reaction {gamma}p{r_arrow}n{phi}{sup +} was carried out at the Saskatchewan Accelerator Laboratory (SAL). The measurement involved the use of the SAL photon-tagging facility, a liquid hydrogen target, and a segmented liquid-scintillator neutron counter. The outgoing neutrons were detected in a forward-angle cone covering 1{degrees}8{degrees} around the beam direction. Data for photon energies ranging from below threshold up to about 6 MeV above threshold were collected simultaneously in 0.25 MeV steps. The motivation and experimental details of the measurement will be outlined along with preliminary results.

  7. Threshold measurement of the λp → nπ+ reaction

    International Nuclear Information System (INIS)

    Korkmaz, E.; O'Rielly, G.V.; Hutcheon, D.A.

    1995-01-01

    Threshold photoproduction of pions off nucleons is one of a few low-energy phenomena for which QCD-based effective field theories can be formulated and tested. As part of a program aimed at determining the threshold amplitudes of the various γN → Nπ channels, a cross section measurement of the reaction γp→nφ + was carried out at the Saskatchewan Accelerator Laboratory (SAL). The measurement involved the use of the SAL photon-tagging facility, a liquid hydrogen target, and a segmented liquid-scintillator neutron counter. The outgoing neutrons were detected in a forward-angle cone covering 1 degrees 8 degrees around the beam direction. Data for photon energies ranging from below threshold up to about 6 MeV above threshold were collected simultaneously in 0.25 MeV steps. The motivation and experimental details of the measurement will be outlined along with preliminary results

  8. Real-time measurement of photocatalytic reactions using a monolithic QCM array

    International Nuclear Information System (INIS)

    Abe, Takashi; Kato, Hiroshi

    2009-01-01

    This paper reports a real-time measurement of photocatalytic reactions by using a miniaturized quartz-crystal microbalance (QCM) array. The QCM was miniaturized and integrated on the same quartz plate using microfabrication techniques. Two QCMs were located close to each other, with one of the QCMs used as a reference sensor for the accurate and independent determination of mass change effects and environmental change effects. The QCM output was compensated for frequency shifts induced by ultra violet (UV) irradiation by subtracting the frequency shift of the reference sensor. The minimum detectable frequency shift under the irradiation was within 1 Hz. The measured photodecomposition speed of methylene blue dye on a TiO 2 -coated QCM agreed well with that evaluated by the standard optical testing method under dry condition. The developed method enabled us to measure the photodecomposition of a surfactant on a TiO 2 -coated QCM with sub-nanogram mass resolution in real time

  9. Ionic Conductivity Measurements-A Powerful Tool for Monitoring Polyol Reduction Reactions.

    Science.gov (United States)

    El-Sayed, Hany A; Burger, Veronika M; Miller, Melanie; Wagenbauer, Klaus; Wagenhofer, Manuel; Gasteiger, Hubert A

    2017-11-28

    The reduction of metal precursors during the polyol synthesis of metal nanoparticles was monitored by ex situ ionic conductivity measurements. Using commonly used platinum precursors (K 2 PtCl 6 , H 2 PtCl 6 , and K 2 PtCl 4 ) as well as iridium and ruthenium precursors (IrCl 3 and RuCl 3 ), we demonstrate that their reduction in ethylene glycol at elevated temperatures is accompanied by a predictable change in ionic conductivity, enabling a precise quantification of the onset temperature for their reduction. This method also allows detecting the onset temperature for the further reaction of ethylene glycol with HCl produced by the reduction of chloride-containing metal precursors (at ≈120 °C). On the basis of these findings, we show that the conversion of the metal precursor to reduced metal atoms/clusters can be precisely quantified, if the reaction occurs below 120 °C, which also enables a distinction between the stages of metal particle nucleation and growth. The latter is demonstrated by the reduction of H 2 PtCl 6 in ethylene glycol, comparing ionic conductivity measurements with transmission electron microscopy analysis. In summary, ionic conductivity measurements are a simple and straightforward tool to quantify the reduction kinetics of commonly used metal precursors in the polyol synthesis.

  10. Measurement of the Amm242 neutron-induced reaction cross sections

    Science.gov (United States)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Wimer, N.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; Ullmann, J. L.; Dance Collaboration

    2017-02-01

    The neutron-induced reaction cross sections of Amm242 were measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. A new neutron-capture cross section was determined, and the absolute scale was set according to a concurrent measurement of the well-known Amm242(n ,f ) cross section. The (n ,γ ) cross section was measured from thermal energy to an incident energy of 1 eV at which point the data quality was limited by the reaction yield in the laboratory. Our new Amm242 fission cross section was normalized to ENDF/B-VII.1 to set the absolute scale, and it agreed well with the (n ,f ) cross section reported by Browne et al. (1984) from thermal energy to 1 keV. The average absolute capture-to-fission ratio was determined from thermal energy to En=0.1 eV, and it was found to be 26(4)% as opposed to the ratio of 19 % from the ENDF/B-VII.1 evaluation.

  11. Method for Determining the Activation Energy Distribution Function of Complex Reactions by Sieving and Thermogravimetric Measurements.

    Science.gov (United States)

    Bufalo, Gennaro; Ambrosone, Luigi

    2016-01-14

    A method for studying the kinetics of thermal degradation of complex compounds is suggested. Although the method is applicable to any matrix whose grain size can be measured, herein we focus our investigation on thermogravimetric analysis, under a nitrogen atmosphere, of ground soft wheat and ground maize. The thermogravimetric curves reveal that there are two well-distinct jumps of mass loss. They correspond to volatilization, which is in the temperature range 298-433 K, and decomposition regions go from 450 to 1073 K. Thermal degradation is schematized as a reaction in the solid state whose kinetics is analyzed separately in each of the two regions. By means of a sieving analysis different size fractions of the material are separated and studied. A quasi-Newton fitting algorithm is used to obtain the grain size distribution as best fit to experimental data. The individual fractions are thermogravimetrically analyzed for deriving the functional relationship between activation energy of the degradation reactions and the particle size. Such functional relationship turns out to be crucial to evaluate the moments of the activation energy distribution, which is unknown in terms of the distribution calculated by sieve analysis. From the knowledge of moments one can reconstruct the reaction conversion. The method is applied first to the volatilization region, then to the decomposition region. The comparison with the experimental data reveals that the method reproduces the experimental conversion with an accuracy of 5-10% in the volatilization region and of 3-5% in the decomposition region.

  12. High-resolution measurement of the 16O(γ,pn) reaction

    International Nuclear Information System (INIS)

    Isaksson, L.

    1996-10-01

    The 16 O(γ,pn) reaction has been measured with a resolution high enough to resolve individual low-lying states in the residual 14 N nucleus. Partial cross-sections, available to the acceptance of the detector system, have been extracted for the individual states, and compared to a recent calculation based on absorption on one-pion exchange currents and the Δ resonance current. The experiment was performed at the Maxlab accelerator laboratory in Lund, Sweden, using tagged photons at an energy of 67 - 76 MeV. The proton detector angular range was 60 - 100 deg and the corresponding for the neutron detector 81 - 103 deg. A missing energy resolution of 1.5 MeV was obtained. The relative population of the states in the residual 14 N nucleus indicates that the reaction takes place predominantly on proton-neutron pairs coupled to (J π ,T) = (1 + ,0). The cross-section for absorption on (0 + ,1) pairs is strongly suppressed. Furthermore, the relative population of the states indicates that both L=0 and L=2 pairs participate in the reaction. 45 refs

  13. Accurate label-free reaction kinetics determination using initial rate heat measurements

    Science.gov (United States)

    Ebrahimi, Kourosh Honarmand; Hagedoorn, Peter-Leon; Jacobs, Denise; Hagen, Wilfred R.

    2015-01-01

    Accurate label-free methods or assays to obtain the initial reaction rates have significant importance in fundamental studies of enzymes and in application-oriented high throughput screening of enzyme activity. Here we introduce a label-free approach for obtaining initial rates of enzyme activity from heat measurements, which we name initial rate calorimetry (IrCal). This approach is based on our new finding that the data recorded by isothermal titration calorimetry for the early stages of a reaction, which have been widely ignored, are correlated to the initial rates. Application of the IrCal approach to various enzymes led to accurate enzyme kinetics parameters as compared to spectroscopic methods and enabled enzyme kinetic studies with natural substrate, e.g. proteases with protein substrates. Because heat is a label-free property of almost all reactions, the IrCal approach holds promise in fundamental studies of various enzymes and in use of calorimetry for high throughput screening of enzyme activity. PMID:26574737

  14. Design of a facility for the in situ measurement of catalytic reaction by neutron scattering spectroscopy

    Science.gov (United States)

    Tan, Shuai; Cheng, Yongqiang; Daemen, Luke L.; Lutterman, Daniel A.

    2018-01-01

    Catalysis is a critical enabling science for future energy needs. The next frontier of catalysis is to evolve from catalyst discovery to catalyst design, and for this next step to be realized, we must develop new techniques to better understand reaction mechanisms. To do this, we must connect catalytic reaction rates and selectivities to the kinetics, energetics, and dynamics of individual elementary steps and relate these to the structure and dynamics of the catalytic sites involved. Neutron scattering spectroscopies offer unique capabilities that are difficult or impossible to match by other techniques. The current study presents the development of a compact and portable instrumental design that enables the in situ investigation of catalytic samples by neutron scattering techniques. The developed apparatus was tested at the Spallation Neutron Source (SNS) in Oak Ridge National Laboratory and includes a gas handling panel that allows for computer hookups to control the panel externally and online measurement equipment such as coupled GC-FID/TCD (Gas Chromatography-Flame Ionization Detector/Thermal Conductivity Detector) and MS (Mass Spectrometry) to characterize offgassing while the sample is in the neutron scattering spectrometer. This system is flexible, modular, compact, and portable enabling its use for many types of gas-solid and liquid-solid reactions at the various beamlines housed at the SNS.

  15. Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Iron

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    DESIG: E 263 09 ^TITLE: Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Iron ^SIGNUSE: Refer to Guide E 844 for guidance on the selection, irradiation, and quality control of neutron dosimeters. Refer to Practice E 261 for a general discussion of the determination of fast-neutron fluence rate with threshold detectors. Pure iron in the form of foil or wire is readily available and easily handled. Fig. 1 shows a plot of cross section as a function of neutron energy for the fast-neutron reaction 54Fe(n,p)54Mn (1). This figure is for illustrative purposes only to indicate the range of response of the 54Fe(n,p)54Mn reaction. Refer to Guide E 1018 for descriptions of recommended tabulated dosimetry cross sections. 54Mn has a half-life of 312.13 days (3) (2) and emits a gamma ray with an energy of 834.845 keV (5). (2) Interfering activities generated by neutron activation arising from thermal or fast neutron interactions are 2.57878 (46)-h 56Mn, 44.95-d (8) 59Fe, and 5.27...

  16. Sonographic Measurement of Lower Uterine Segment Thickness to Predict Uterine Rupture During a Trial of Labor in Women With Previous Cesarean Section: A Meta-analysis

    NARCIS (Netherlands)

    Kok, N.; Wiersma, I. C.; Opmeer, B. C.; de Graaf, I. M.; Mol, B. W.; Pajkrt, E.

    2014-01-01

    Along with the increasing rate of cesarean section (CS) births has been a concomitant decrease in the rate of vaginal birth after cesarean (VBAC), mostly due to concerns about uterine rupture during a trial of labor (TOL). The risk of uterine rupture in laboring women with a previous CS must be

  17. Measuring kinetic rate constants of multiple-component reactions with optical biosensors.

    Science.gov (United States)

    Edwards, David A; Evans, Ryan M; Li, Wenbin

    2017-09-15

    One may measure the kinetic rate constants associated with biochemical reactions using an optical biosensor: an instrument in which ligand molecules are convected through a flow cell over a surface to which receptors are immobilized. If there are multiple reactants, one is faced with the problem of fitting multiple kinetic rate constants to one signal, since data from all of the reacting species is lumped together. Even in the presence of ambiguous data, one may use a series of experiments to accurately determine the rate constants. Moreover, the true set of rate constants may be identified by either postprocessing the signals or adjusting the ligand inflow concentrations. Published by Elsevier Inc.

  18. Measurement and analysis of excitation functions in (α,np) reactions on 128,130Te

    International Nuclear Information System (INIS)

    Singh, B.P.; Sankaracharyulu, M.G.V.; Ansari, M.A.; Prasad, R.; Bhardwaj, H.D.

    1992-02-01

    Excitation functions for the reactions 128 Te(α,np) 130 I, 130 Te(α,np) 132 I and 130 Te(α,np) 132m I have been measured using stacked foil technique and have also been calculated using statistical model with and without the inclusion of pre-equilibrium emission. As expected, inclusion of pre-equilibrium emission in compound nucleus calculations agree well with the experimental excitation functions. The pre-equilibrium fraction has been found to be energy and target mass number dependent. (author). 37 refs, 7 figs, 3 tabs

  19. Cross section measurement of alpha particle induced nuclear reactions on natural cadmium up to 52 MeV

    OpenAIRE

    Ditrói, F.; Takács, S.; Haba, H.; Komori, Y.; Aikawa, M.

    2016-01-01

    Cross sections of alpha particle induced nuclear reactions have been measured on thin natural cadmium targets foils in the energy range from 11 to 51.2 MeV. This work was a part of our systematic study on excitation functions of light ion induced nuclear reactions on different target materials. Regarding the cross sections, the alpha induced reactions are not deeply enough investigated. Some of the produced isotopes are of medical interest, others have application in research and industry. Th...

  20. Measurement of the ${240}$Pu(n,f) reaction cross-section

    CERN Multimedia

    Following proposal CERN-INTC-2010-042 / INTC-P-280 (“Measurement of the fission cross-section of $^{240}$Pu and $^{242}$Pu at CERN’s n_TOF Facility”), the parallel measurement of the $^{240}$Pu(n,f) and $^{242}$Pu(n,f) reaction cross-sections was carried out at n_TOF EAR-1. While the $^{242}$Pu measurement was successful, unexpected sample-induced damage to the detectors caused by the high α-activity of the 240Pu samples resulted in a deterioration of the detector performance over the data taking period of several months, which compromised the measurement. This obstacle can be eliminated by performing the measurement in EAR-2, where the higher neutron flux will allow collecting data in a much shorter time, thus preventing the degradation of the detectors. In addition to this obvious advantage, the measurement would also benefit from the stronger suppression of the sample-induced α-background, due to the shorter times-of-flight involved.

  1. Relating gas chromatographic profiles to sensory measurements describing the end products of the Maillard reaction.

    Science.gov (United States)

    Stanimirova, I; Boucon, C; Walczak, B

    2011-01-30

    Often in analytical practice, a set of samples is described by different types of measurements in the hope that a comprehensive characterisation of samples will provide a more complete picture and will help in determining the similarities among samples. The main focus is then on how to combine the information described by different measurement variables and how to analyse it simultaneously. In other words, the main goal is to find a common representation of samples that emphasises the individual and common properties of the different blocks of variables. Several methods can be adopted for the simultaneous analysis of multiblock data with a common object mode. These are: consensus principal component analysis (CPCA), SUM-PCA, multiple factor analysis (MFA) and structuration des tableaux à trois indices de la statistique (STATIS).In this article we present a comparison of the performances of these methods for data describing the chemistry and sensory profiles of the Maillard reaction products. The aroma compounds formed during the reaction of thermal heating between one or two selected amino acids and one or two reducing sugars have been analysed by head space gas chromatography and the intensity and nature of the odour of the resulting products has been evaluated according to selected descriptors by a panel of sensory experts.The results showed that using the information of the chromatographic and sensory data in conjunction enhanced the interpretability of the data. SUM-PCA and more specifically multiple factor analysis, MFA, allowed for a detailed study of the similarities of mixtures in terms of reaction products and sensory profiles. Copyright © 2010 Elsevier B.V. All rights reserved.

  2. Revised Production Rates for Na-22 and Mn-54 in Meteorites Using Cross Sections Measured for Neutron-induced Reactions

    Science.gov (United States)

    Sisterson, J. M.; Kim, K. J.; Reedy, R. C.

    2004-01-01

    The interactions of galactic cosmic rays (GCR) with extraterrestrial bodies produce small amounts of radionuclides and stable isotopes. The production rates of many relatively short-lived radionuclides, including 2.6-year Na-22 and 312-day Mn-54, have been measured in several meteorites collected very soon after they fell. Theoretical models used to calculate production rates for comparison with the measured values rely on input data containing good cross section measurements for all relevant reactions. Most GCR particles are protons, but secondary neutrons make most cosmogenic nuclides. Calculated production rates using only cross sections for proton-induced reactions do not agree well with measurements. One possible explanation is that the contribution to the production rate from reactions initiated by secondary neutrons produced in primary GCR interactions should be included explicitly. This, however, is difficult to do because so few of the relevant cross sections for neutron-induced reactions have been measured.

  3. Measurement and analysis of cross sections for (p,x) reactions on natural molybdenum

    International Nuclear Information System (INIS)

    Challan, M. B.; Comsan, M.N.H.; Abou-Zeid, M.A.

    2006-01-01

    Excitation functions (EFs) for the reactions n atMo(p,x) 92m Nb, and n atMo(p,x) 94 , 95m , 95g , 96 m, +g , 99m Tc up to 18 MeV from threshold have been measured employing the stacked foil activation technique, and using high resolution HPGe gamma spectrometry. Utilizing the simultaneous measurement of the excitation function of n atCu(p,x) 62 Zn, n atCu(p,x) 63 Zn, n atCu(p,x) 65 Zn, and n atTi(p,x) 48 V monitor reactions. The theoretical analysis of the EFs has been done using both the semi-classical as well as quantum mechanical codes which include compound nucleus and pre-equilibrium (PE) emission into consideration. In general, theoretical calculations agree well with the experimental data. Effect of various free parameters used in the calculations has also been discussed. A significant contribution of pre-equilibrium component has been observed at these energies

  4. Measurement of thermal neutron cross section for {sup 241}Am(n,f) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Katsuhei; Yamamoto, Shuji; Fujita, Yoshiaki [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Miyoshi, Mitsuharu; Kimura, Itsuro; Kanno, Ikuo; Shinohara, Nobuo

    1997-03-01

    Making use of a standard neutron spectrum field with a pure Maxwellian distribution, the thermal neutron cross section for the {sup 241}Am(n,f) reaction has been measured relative to the reference value of 586.2b for the {sup 235U}(n,f) reaction. For the present measurement, electrodeposited layers of {sup 241}Am and {sup 235}U have been employed as back-to-back type double fission chambers. The present result at neutron energy of 0.0253 eV is 3.15 {+-} 0.097b. The ENDF/B-VI data is in good agreement with the present value, while the JENDL-3.2 data is lower by 4.2%. The evaluated data in JEF-2.2 and by Mughabghab are higher by 0.9% and 1.6%, respectively than the present result. The ratios of the earlier experimental data to the present value are distributed between 0.89 and 1.02. (author)

  5. An update on measurements of helium-production reactions with a spallation neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Haight, R.C.; Bateman, F.B.; Chadwick, M.B. [and others

    1995-10-01

    This report gives the status, updated since the last Research Coordination Meeting, of alpha-particle production cross sections, emission spectra and angular distributions which we are measuring at the spallation source of fast neutrons at the Los Alamos Meson Physics Facility (LAMPF). Detectors at angles of 30, 60, 90 and 135{degrees} are used to identify alpha particles, measure their energy spectra, and indicate the time-of-flight, and hence the energy, of the neutrons inducing the reaction. The useful neutron energy ranges from less than 1 MeV to approximately 50 MeV for the present experimental setup. Targets under study at present include C, N, 0, {sup 27}Al, Si, {sup 51}V, {sup 56}Fe, {sup 59}CO, {sup 58,60}Ni, {sup 89}Y and {sup 93}Nb. Data for {sup 59}Co have been re-analyzed. The results illustrate the capabilities of the approach, agreement with literature values, and comparisons with nuclear reaction model calculations.

  6. The measurement of silicon in a lung phantom--a comparison of two nuclear reactions for in vivo activation analysis.

    Science.gov (United States)

    Kacperek, A; Ryde, S J; Evans, C J; Dutton, J; Morgan, W D; Sivyer, A

    1993-06-01

    The amount of silica in the human lung may be estimated by measurement of silicon using in vivo neutron activation analysis. A pulsed, fast neutron beam, produced with a 2 MV Van de Graaff generator using the 2H + 2H reaction, was used to irradiate a Si-doped chest phantom in order to determine minimum detection limits (MDL). Two 'in-beam' nuclear reactions on Si were studied; prompt fast neutron inelastic scatter 28Si (n,n' gamma)28Si reaction was measured during the beam burst and the slow neutron prompt capture reaction was measured between the fast neutron bursts. Although the latter reaction appeared less favourable due to neutron cross section and measurement efficiency considerations, it yielded an MDL of 1.8 g compared with 2.3 g for the 28Si(n,n' gamma)28Si reaction. A comparison was made with a 252Cf neutron irradiation system where a Si MDL of 6.3 g was obtained using the slow neutron capture reaction. The Van de Graaff system permits 'exposed' Si lung burdens to be measured but not normal levels. Improved measurement sensitivity may be achieved by reduction of high counting-rate losses and high background radiation.

  7. In situ measurement of reaction volume and calculation of pH of weak acid buffer solutions under high pressure.

    Science.gov (United States)

    Min, Stephen K; Samaranayake, Chaminda P; Sastry, Sudhir K

    2011-05-26

    Direct measurements of reaction volume, so far, have been limited to atmospheric pressure. This study describes a method for in situ reaction volume measurements under pressure using a variable volume piezometer. Reaction volumes for protonic ionization of weak acid buffering agents (MES, citric acid, sulfanilic acid, and phosphoric acid) were measured in situ under pressure up to 400 MPa at 25 °C. The methodology involved initial separation of buffering agents within the piezometer using gelatin capsules. Under pressure, the volume of the reactants was measured at 25 °C, and the contents were heated to 40 °C to dissolve the gelatin and allow the reaction to occur, and cooled to 25 °C, where the volume of products was measured. Reaction volumes were used to calculate pH of the buffer solutions as a function of pressure. The results show that the measured reaction volumes as well as the calculated pH values generally quite agree with their respective theoretically predicted values up to 100 MPa. The results of this study highlight the need for a comprehensive theory to describe the pressure behavior of ionization reactions in realistic systems especially at higher pressures.

  8. Measurements of cross-sections of the proton-induced activation reactions

    CERN Document Server

    Uddin, M S; Ditrói, F; Hagiwara, M; Tarkanyi, F

    2005-01-01

    Excitation functions for the /sup 89/Y(p, x)/sup 89,88,86/Zr, /sup 89 /Y(p, x)/sup 88,87,87m,86/Y, /sup 89/Y(p, x)/sup 85,83,82/Sr and /sup 89/Y(p, x)/sup 84,83/Rb reactions were measured by a stacked foil activation technique in the energy range 15-80 MeV. The production for the long lived products like /sup 88/Zr, and /sup 88/Y are significantly larger than that of /sup nat/Mo+p, /sup nat/Nb+p and /sup nat/Zr+p processes. The productions of the medical isotopes, /sup 85/Sr and /sup 83/Sr are also effective by Y+p process using 80 MeV beam. The model calculations using ALICE-IPPE code compiled in MENDL-2P have the general trend of the measured results.

  9. Preliminary measurements of neutrons from the D-D reaction in the COMPASS tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Dankowski, J., E-mail: jan.dankowski@ifj.edu.pl; Kurowski, A.; Twarog, D. [The Henryk Niewodniczański Institute of Nuclear Physics Polish Academy of Sciences, Radzikowskiego 152 Str., PL-31-342 Kraków (Poland); Janky, F.; Stockel, J. [Institute of Plasma Physics AS CR, v.v.i. Za Slovankou 1782/3, 182 00 Prague 8 (Czech Republic)

    2014-08-21

    Recent results of measured fast neutrons created in the D-D reaction on the COMPASS tokamak during ohmic discharges are presented in this paper. Two different type detectors were used during experiment. He-3 detectors and bubble detectors as a support. The measurements are an introduction for neutron diagnostic on tokamak COMPASS and monitoring neutrons during discharges with Neutral Beam Injection (NBI). The He-3 counters and bubble detectors were located in two positions near tokamak vacuum chamber at a distance less than 40 cm to the centre of plasma. The neutrons flux was observed in ohmic discharges. However, analysis of our results does not indicate any clear source of neutrons production during ohmic discharges.

  10. Formaldehyde measurements by Proton transfer reaction – Mass Spectrometry (PTR-MS: correction for humidity effects

    Directory of Open Access Journals (Sweden)

    A. Vlasenko

    2010-08-01

    Full Text Available Formaldehyde measurements can provide useful information about photochemical activity in ambient air, given that HCHO is formed via numerous oxidation processes. Proton transfer reaction mass spectrometry (PTR-MS is an online technique that allows measurement of VOCs at the sub-ppbv level with good time resolution. PTR-MS quantification of HCHO is hampered by the humidity dependence of the instrument sensitivity, with higher humidity leading to loss of PTR-MS signal. In this study we present an analytical, first principles approach to correct the PTR-MS HCHO signal according to the concentration of water vapor in sampled air. The results of the correction are validated by comparison of the PTR-MS results to those from a Hantzsch fluorescence monitor which does not have the same humidity dependence. Results are presented for an intercomparison made during a field campaign in rural Ontario at Environment Canada's Centre for Atmospheric Research Experiments.

  11. Preliminary measurements of neutrons from the D-D reaction in the COMPASS tokamak

    Science.gov (United States)

    Dankowski, J.; Janky, F.; Kurowski, A.; Stockel, J.; Twarog, D.

    2014-08-01

    Recent results of measured fast neutrons created in the D-D reaction on the COMPASS tokamak during ohmic discharges are presented in this paper. Two different type detectors were used during experiment. He-3 detectors and bubble detectors as a support. The measurements are an introduction for neutron diagnostic on tokamak COMPASS and monitoring neutrons during discharges with Neutral Beam Injection (NBI). The He-3 counters and bubble detectors were located in two positions near tokamak vacuum chamber at a distance less than 40 cm to the centre of plasma. The neutrons flux was observed in ohmic discharges. However, analysis of our results does not indicate any clear source of neutrons production during ohmic discharges.

  12. Use of micrometers and calipers to measure various components of delayed-type hypersensitivity ear swelling reactions in mice

    NARCIS (Netherlands)

    Loveren, H. van; Kato, K.; Ratzlaff, R.E.; Meade, R.; Ptak, W.; Askenase, P.W.

    1984-01-01

    The choice of the type of instrument to measure delayed-type hypersensitivity (DTH) in mice, as assayed by ear swelling reactions, influences the experimental results. When a caliper that applies little pressure to the ears is employed, DTH reactions in ears of mice sensitized to picryl chloride

  13. The intensity of segregation of the OH-Isoprene reaction -measurements above the amazon rain forest-

    Science.gov (United States)

    Sörgel, Matthias; Berger, Martina; Dlugi, Ralph; Harder, Hartwig; Kesselmeier, Jürgen; Mallik, Chinmay; Marno, Daniel; Tsokankunku, Anywhere; Wolff, Stefan; Yanez-Serrano, Ana-Maria; Zelger, Michael

    2017-04-01

    Incomplete mixing (segregation) causes reduced reaction rates compared to laboratory values derived for well mixed conditions. The dominant contribution to atmospheric chemistry is given by the most important oxidizing agent, the OH-radical, which is regarded as the detergent of the atmosphere as it reacts with the majority of atmospheric pollutants and therefore accelerates their removal from the atmosphere. Hence, to understand atmospheric self-cleansing, we need to quantify and understand the budgets (sources and sinks) of OH. Budgets are generally derived by measuring mixing ratios of known source molecules (either primary or recycling) and the total sink for OH of which isoprene is an important part in the pristine rain forest. The production and loss terms are calculated by using the measured mixing ratios and the laboratory derived kinetic values. If reactants are not well mixed their actual reaction rates are lower in the atmosphere than in the laboratory. Therefore, segregation might play a substantial role in quantifying and understanding the derived budgets. We measured OH-radicals, isoprene and other species (O3, NOx, HO2, H2O) with high time resolution (1-10 Hz) shortly above a rain forest canopy (41 m above ground level) at the ATTO (Amazon Tall Tower Observatory) site (02°08'38.8''S, 58°59'59.5''W). The site is characterized by high isoprene (up to 20 ppb) and low NO (50 ppt - 500 ppt). Simultaneous measurements of OH and isoprene with high time resolution (necessary to directly calculate the intensity of segregation) are sparse. To our knowledge this is now the third dataset for OH-isoprene segregation but the first from a tropical rain forest. The results will be compared to modeling results from different environments and the effect of trace gas exchange driven by coherent structures on the intensity of segregation will be evaluated as well.

  14. Reprint of: Reaction measurements with the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) gas jet target

    Science.gov (United States)

    Chipps, K. A.

    2018-01-01

    Explosive stellar environments are sometimes driven by nuclear reactions on short-lived, radioactive nuclei. These reactions often drive the stellar explosion, alter the observable light curves produced, and dictate the final abundances of the isotopes created. Unfortunately, many reaction rates at stellar temperatures cannot be directly measured in the laboratory, due to the physical limitations of ultra-low cross sections and high background rates. An additional complication arises because many of the important reactions involve radioactive nuclei which have lifetimes too short to be made into a target. As such, direct reactions require very intense and pure beams of exotic nuclei. Indirect approaches with both stable and radioactive beams can, however, provide crucial information on the nuclei involved in these astrophysical reactions. A major development toward both direct and indirect studies of nuclear reactions rates is the commissioning of the Jet Experiments in Nuclear Structure and Astrophysics (JENSA) supersonic gas jet target. The JENSA system provides a pure, homogeneous, highly localized, dense, and robust gaseous target for radioactive ion beam studies. Charged-particle reactions measurements made with gas jet targets can be cleaner and display better resolution than with traditional targets. With the availability of pure and localized gas jet targets in combination with developments in exotic radioactive ion beams and next-generation detector systems, the range of reaction studies that are experimentally possible is vastly expanded. Various representative cases will be discussed.

  15. Methods for quantifying the influences of pressure and temperature variation on metal hydride reaction rates measured under isochoric conditions.

    Science.gov (United States)

    Voskuilen, Tyler G; Pourpoint, Timothée L

    2013-11-01

    Analysis techniques for determining gas-solid reaction rates from gas sorption measurements obtained under non-constant pressure and temperature conditions often neglect temporal variations in these quantities. Depending on the materials in question, this can lead to significant variations in the measured reaction rates. In this work, we present two new analysis techniques for comparison between various kinetic models and isochoric gas measurement data obtained under varying temperature and pressure conditions in a high pressure Sievert system. We introduce the integral pressure dependence method and the temperature dependence factor as means of correcting for experimental variations, improving model-measurement fidelity, and quantifying the effect that such variations can have on measured reaction rates. We use measurements of hydrogen absorption in LaNi5 and TiCrMn to demonstrate the effect of each of these methods and show that their use can provide quantitative improvements in interpretation of kinetics measurements.

  16. The neutron-proton charge-exchange amplitudes measured in the dp {yields} ppn reaction

    Energy Technology Data Exchange (ETDEWEB)

    Mchedlishvili, D.; Chiladze, D. [Tbilisi State University, High Energy Physics Institute, Tbilisi (Georgia); Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Centre for Hadron Physics, Juelich (Germany); Barsov, S.; Dzyuba, A. [Petersburg Nuclear Physics Institute, High Energy Physics Department, Gatchina (Russian Federation); Carbonell, J. [Universite Paris-Sud, IN2P3-CNRS, Institut de Physique Nucleaire, Orsay Cedex (France); Dymov, S. [JINR, Laboratory of Nuclear Problems, Dubna (Russian Federation); Universitaet Erlangen-Nuernberg, Physikalisches Institut II, Erlangen (Germany); Engels, R.; Gebel, R.; Hartmann, M.; Kacharava, A.; Kamerdzhiev, V.; Lehrach, A.; Lorentz, B.; Maier, R.; Ohm, H.; Prasuhn, D.; Rathmann, F.; Serdyuk, V.; Seyfarth, H.; Stein, H.J.; Stockhorst, H.; Stroeher, H. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Centre for Hadron Physics, Juelich (Germany); Glagolev, V. [JINR, Laboratory of High Energies, Dubna (Russian Federation); Grigoryev, K.; Mikirtychyants, M.; Mikirtychyants, S.; Valdau, Yu. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Centre for Hadron Physics, Juelich (Germany); Petersburg Nuclear Physics Institute, High Energy Physics Department, Gatchina (Russian Federation); Goslawski, P.; Khoukaz, A.; Mielke, M.; Papenbrock, M. [Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Keshelashvili, I. [Tbilisi State University, High Energy Physics Institute, Tbilisi (Georgia); University of Basel, Department of Physics, Basel (Switzerland); Komarov, V.; Kulikov, A. [JINR, Laboratory of Nuclear Problems, Dubna (Russian Federation); Kulessa, P. [H. Niewodniczanski Institute of Nuclear Physics PAN, Krakow (Poland); Lomidze, N.; Nioradze, M.; Tabidze, M. [Tbilisi State University, High Energy Physics Institute, Tbilisi (Georgia); Macharashvili, G. [Tbilisi State University, High Energy Physics Institute, Tbilisi (Georgia); JINR, Laboratory of Nuclear Problems, Dubna (Russian Federation); Merzliakov, S. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Centre for Hadron Physics, Juelich (Germany); JINR, Laboratory of Nuclear Problems, Dubna (Russian Federation); Steffens, E. [Universitaet Erlangen-Nuernberg, Physikalisches Institut II, Erlangen (Germany); Trusov, S. [Forschungszentrum Rossendorf, Institut fuer Kern- und Hadronenphysik, Dresden (Germany); Uzikov, Yu. [JINR, Laboratory of Nuclear Problems, Dubna (Russian Federation); M. V. Lomonosov Moscow State University, Department of Physics, Moscow (Russian Federation); Wilkin, C. [UCL, Physics and Astronomy Department, London (United Kingdom)

    2013-04-15

    The unpolarised differential cross section and the two deuteron tensor analysing powers A{sub xx} and A{sub yy} of the vector dp {yields} {l_brace}pp{r_brace}{sub s}n charge-exchange reaction have been measured with the ANKE spectrometer at the COSY storage ring. Using deuteron beams with energies 1.2, 1.6, 1.8, and 2.27GeV, data were obtained for small momentum transfers to a {l_brace}pp{r_brace}{sub s} system with low excitation energy. The results at the three lower energies are consistent with impulse approximation predictions based upon the current knowledge of the neutron-proton amplitudes. However, at 2.27GeV, where these amplitudes are far more uncertain, agreement requires a reduction in the overall double-spin-flip contribution, with an especially significant effect in the longitudinal direction. These conclusions are supported by measurements of the deuteron-proton spin-correlation parameters C{sub x,x} and C{sub y,y} that were carried out in the vector dvector p {yields} {l_brace}pp{r_brace}{sub s}n reaction at 1.2 and 2.27GeV. The values obtained for the proton analysing power A{sub y}{sup p} also suggest the need for a radical re-evaluation of the neutron-proton elastic scattering amplitudes at the higher energy. It is therefore clear that such measurements can provide a valuable addition to the neutron-proton database in the charge-exchange region. (orig.)

  17. Energy-differential cross section measurement for the 51V(n,α)48Sc reaction

    International Nuclear Information System (INIS)

    Kanno, I.; Meadows, J.W.; Smith, D.L.

    1984-07-01

    The activation method was used to measure cross sections for the 51 V(n,α) 48 Sc reaction in the threshold region, from 5.515 MeV up to 9.567 MeV. Twenty approximately-monoenergetic cross section values were obtained in this experiment. These data points span the energy region at roughly equal intervals. The experimental resolutions were in the range 0.153 to 0.233 MeV (FWHM). The present differential data cover approx. 50% of the total integral response of this reaction for the standard 235 U thermal-neutron-induced-fission neutron spectrum, and approx. 44% of the corresponding response for the standard 252 Cf spontaneous-fission neutron spectrum. Over the range 7.6 to 9.5 MeV the present experimental cross sections are noticeably larger (e.g., by approx. 50% at approx. 8.6 MeV) than the corresponding values from the ENDF/B-V evaluation. From approx. 6.7 to 7.5 MeV, the present values are somewhat below those of ENDF/B-V. At still lower energies the agreement is reasonably good considering the uncertainties introduced by energy scale definition very near the effective threshold where the cross section varies rapidly with neutron energy. Calculated integral cross sections based in part on the present work agree reasonably well within errors with reported integral results, provided that the reported data are renormalized to conform with recently-accepted values for appropriate standard reactions. 70 references

  18. Measuring dynamic and kinetic information in the previously inaccessible supra-τ(c) window of nanoseconds to microseconds by solution NMR spectroscopy.

    Science.gov (United States)

    Ban, David; Sabo, T Michael; Griesinger, Christian; Lee, Donghan

    2013-09-26

    Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful tool that has enabled experimentalists to characterize molecular dynamics and kinetics spanning a wide range of time-scales from picoseconds to days. This review focuses on addressing the previously inaccessible supra-tc window (defined as τ(c) supra-τ(c) supra-τ(c) window. In the second section, the current state of the art for RD is analyzed, as well as the considerable progress toward pushing the sensitivity of RD further into the supra-τ(c) scale by up to a factor of two (motion up to 25 μs). From the data obtained with these techniques and methodology, the importance of the supra-τ(c) scale for protein function and molecular recognition is becoming increasingly clearer as the connection between motion on the supra-τ(c) scale and protein functionality from the experimental side is further strengthened with results from molecular dynamics simulations.

  19. Both Reaction Time and Accuracy Measures of Intraindividual Variability Predict Cognitive Performance in Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Björn U. Christ

    2018-04-01

    Full Text Available Dementia researchers around the world prioritize the urgent need for sensitive measurement tools that can detect cognitive and functional change at the earliest stages of Alzheimer's disease (AD. Sensitive indicators of underlying neural pathology assist in the early detection of cognitive change and are thus important for the evaluation of early-intervention clinical trials. One method that may be particularly well-suited to help achieve this goal involves the quantification of intraindividual variability (IIV in cognitive performance. The current study aimed to directly compare two methods of estimating IIV (fluctuations in accuracy-based scores vs. those in latency-based scores to predict cognitive performance in AD. Specifically, we directly compared the relative sensitivity of reaction time (RT—and accuracy-based estimates of IIV to cognitive compromise. The novelty of the present study, however, centered on the patients we tested [a group of patients with Alzheimer's disease (AD] and the outcome measures we used (a measure of general cognitive function and a measure of episodic memory function. Hence, we compared intraindividual standard deviations (iSDs from two RT tasks and three accuracy-based memory tasks in patients with possible or probable Alzheimer's dementia (n = 23 and matched healthy controls (n = 25. The main analyses modeled the relative contributions of RT vs. accuracy-based measures of IIV toward the prediction of performance on measures of (a overall cognitive functioning, and (b episodic memory functioning. Results indicated that RT-based IIV measures are superior predictors of neurocognitive impairment (as indexed by overall cognitive and memory performance than accuracy-based IIV measures, even after adjusting for the timescale of measurement. However, one accuracy-based IIV measure (derived from a recognition memory test also differentiated patients with AD from controls, and significantly predicted episodic memory

  20. Site-specific reaction rate constant measurements for various secondary and tertiary H-abstraction by OH radicals

    KAUST Repository

    Badra, Jihad

    2015-02-01

    Reaction rate constants for nine site-specific hydrogen atom (H) abstraction by hydroxyl radicals (OH) have been determined using experimental measurements of the rate constants of Alkane+OH→Products reactions. Seven secondary (S 20, S 21, S 22, S 30, S 31, S 32, and S 33) and two tertiary (T 100 and T 101) site-specific rate constants, where the subscripts refer to the number of carbon atoms (C) connected to the next-nearest-neighbor (N-N-N) C atom, were obtained for a wide temperature range (250-1450K). This was done by measuring the reaction rate constants for H abstraction by OH from a series of carefully selected large branched alkanes. The rate constant of OH with four different alkanes, namely 2,2-dimethyl-pentane, 2,4-dimethyl-pentane, 2,2,4-trimethyl-pentane (iso-octane), and 2,2,4,4-tetramethyl-pentane were measured at high temperatures (822-1367K) using a shock tube and OH absorption diagnostic. Hydroxyl radicals were detected using the narrow-line-width ring-dye laser absorption of the R1(5) transition of OH spectrum near 306.69nm.Previous low-temperature rate constant measurements are added to the current data to generate three-parameter rate expressions that successfully represent the available direct measurements over a wide temperature range (250-1450. K). Similarly, literature values of the low-temperature rate constants for the reaction of OH with seven normal and branched alkanes are combined with the recently measured high-temperature rate constants from our group [1]. Subsequent to that, site-specific rate constants for abstractions from various types of secondary and tertiary H atoms by OH radicals are derived and have the following modified Arrhenius expressions:. S20=8.49×10-17T1.52exp(73.4K/T)cm3molecule-1s-1(250-1450K) S21=1.07×10-15T1.07exp(208.3K/T)cm3molecule-1s-1(296-1440K) S22=2.88×10-13T0.41exp(-291.5K/T)cm3molecule-1s-1(272-1311K) S30=3.35×10-18T1.97exp(323.1K/T)cm3molecule-1s-1(250-1366K) S31=1.60×10-18T2.0exp(500.0K/T)cm3

  1. Measurement of excitation functions in alpha-induced reactions on yttrium

    Energy Technology Data Exchange (ETDEWEB)

    Shahid, Muhammad; Kim, Kwangsoo [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Naik, Haladhara [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Zaman, Muhammad [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kim, Guinyun, E-mail: gnkim@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Yang, Sung-Chul [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Song, Tae-Young [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of)

    2015-01-01

    The excitation functions of {sup 89g,m,90,91m,92m}Nb,{sup 88,89}Zr, and {sup 87g,m,88,90m,91m}Y from alpha-induced reactions on {sup 89}Y were measured from their respective threshold to 45 MeV by using a stacked-foil activation technique at the MC-50 cyclotron of the Korean Institute of Radiological and Medical Sciences. The results were compared with the earlier reported data as well as with the theoretical values obtained from the TENDL-2013 library based on the TALYS1.6 code. Our measurements in the energy region from the threshold energy to 45 MeV are in general good agreement with the other experimental data and calculated results. The integral yields for thick target of the produced radionuclides were also deduced from their measured cross sections and the stopping power of {sup 89}Y. The measured excitation functions find importance in various practical applications including nuclear medicine and improvement of nuclear model calculations.

  2. Measurements of neutron induced capture and fission reactions on $^{233}$ U (EAR1)

    CERN Multimedia

    The $^{233}$U plays the essential role of ssile nucleus in the Th-U fuel cycle, which has been proposed as a safer and cleaner alternative to the U-Pu fuel cycle. Considered the scarce data available to assess the capture cross section, a measurement was proposed and successfully performed at the n_TOF facility at CERN using the 4$\\pi$ Total Absorp- tion Calorimeter (TAC). The measurement was extremely dicult due to the need to accurately distinguish between capture and fission $\\gamma$-rays without any additional discrim-ination tool and the measured capture cross section showed a signicant disagreement in magnitude when compared with the ENDF/B-VII.1 library despite the agreement in shape. We propose a new measurement that is aimed at providing a higher level of dis-crimination between competing nuclear reactions, to extend the neutron energy range and to obtain more precise and accurate data, thus fullling the demands of the "NEA High Priority Nuclear Data Request List". The setup is envisaged as a combin...

  3. In situ laser measurement of oxygen concentration and flue gas temperature utilizing chemical reaction kinetics.

    Science.gov (United States)

    Viljanen, J; Sorvajärvi, T; Toivonen, J

    2017-12-01

    Combustion research requires detailed localized information on the dynamic combustion conditions to improve the accuracy of the simulations and, hence, improve the performance of the combustion processes. We have applied chemical reaction kinetics of potassium to measure the local temperature and O 2 concentration in flue gas. An excess of free atomic potassium is created in the measurement volume by a photofragmenting precursor molecule such as potassium chloride or KOH which are widely released from solid fuels. The decay of the induced potassium concentration is followed with an absorption measurement using a narrow-linewidth diode laser. The temperature and O 2 concentration are solved from the decay curve features using equations obtained from calibration measurements in a temperature range of 800°C-1000°C and in O 2 concentrations of 0.1%-21%. The local flue gas temperature and O 2 concentration were recorded in real time during devolatilization, char burning, and ash cooking phases of combustion in a single-particle reactor with a 5 Hz repetition rate. The method can be further extended to other target species and applications where the chemical dynamics can be disturbed with photofragmentation.

  4. Actinometric measurement of solar ultraviolet and development of a weighted solar UV integral. [photochemical reaction rate determination

    Science.gov (United States)

    Gupta, A.; Coulbert, C.

    1978-01-01

    An actinometer has been developed to measure outdoor irradiance in the range 295-400 nm. Actinometric measurements of radiation are based on determination of photochemical reaction rates for reactions of known quantum efficiency. Actinometers have the advantage of providing irradiance data over surfaces of difficult accessibility; in addition, actinometrically determined irradiance data are wavelength weighted and therefore provide a useful means of assessing the degradation rates of polymers employed in solar energy systems.

  5. Kinetic analysis of ski turns based on measured ground reaction forces.

    Science.gov (United States)

    Vaverka, Frantisek; Vodickova, Sona; Elfmark, Milan

    2012-02-01

    The objective of this study was to devise a method of kinetic analysis of the ground reaction force that enables the durations and magnitudes of forces acting during the individual phases of ski turns to be described exactly. The method is based on a theoretical analysis of physical forces acting during the ski turn. Two elementary phases were defined: (1) preparing to turn (initiation) and (2) actual turning, during which the center of gravity of the skier-ski system moves along a curvilinear trajectory (steering). The starting point of the turn analysis is a dynamometric record of the resultant acting ground reaction force applied perpendicularly on the ski surface. The method was applied to six expert skiers. They completed a slalom course comprising five gates arranged on the fall line of a 26° slope at a competition speed using symmetrical carving turns (30 evaluated turns). A dynamometric measurement system was placed on the carving skis (168 cm long, radius 16 m, data were recorded at 100 Hz). MATLAB procedures were used to evaluate eight variables during each turn: five time variables and three force variables. Comparison of the turn analysis results between individuals showed that the method is useful for answering various research questions associated with ski turns.

  6. Ion Chromatographic Method with Post-Column Fuchsin Reaction for Measurement of Bromate in Chlorinated Water

    Directory of Open Access Journals (Sweden)

    Homer C. Genuino

    2009-06-01

    Full Text Available An ion chromatographic method that employs a post-column reaction with fuchsin and spectrophotometric detection was optimized for measuring bromate (BrO3- in water. BrO3- is converted to Br2 by sodium metabisulfite and then reacted with acidic fuchsin to form a red-colored product that strongly absorbs at 530 nm. The reaction of BrO3- and fuchsin reagent is optimum at pH 3.5 and 65 oC. The method has a limit of quantitation of 4.5 µg L-1 and is linear up to 150 µg L-1 BrO3-. Recoveries from spiked samples were high ranging from 95 to 102 % using external standard calibration and 87 to 103 % using standard addition method. Intra-batch and inter-batch reproducibility studies of the method resulted to RSD values ranging from 0.62 to 2.01 % and percent relative error of 0.12 to 2.94 % for BrO3- concentrations of 10 µg L-1 and 50 µg L-1. This method is free of interferences from common inorganic anions at levels typically found in chlorinated tap drinking water without preconcentration. The optimized method can be applied to trace analysis of bromate in chlorinated tap drinking water samples.

  7. Reaction Rate Measurement at the Californium User Facility (CUF) for unfolding the neutron spectrum

    Science.gov (United States)

    Hannan, Mohammad; Ortega, Ruben

    2011-03-01

    Neutron Activation Analysis was used to determine Reaction Rate measurement of several activation detectors at the ORNL Californium User Facility (CUF). The irradiations were performed with 34 mg Cf 252 neutron source strength.. Ten source capsules > 34 mgwerepositionedconcentricallyaroundasamplecavity . Wehavedeterminedabsoluteactivityperatomof 9 detectors : Au 197 (n , γ) Au 198 , Al 27 (n , α) Na 24 , Al 27 (n , p) Mg 27 , Fe 56 (n , p) Mn 5 , Fe 54 (n , p) Mn 54 , In 115 (n , γ) In 116 , Ti 46 (n , p) Sc 46 , Ni 60 (n , p) Co 60 , Fe 58 (n , γ) Fe 59 . Theerrorsarewithin 1.5 - 8 60 and Fe 58 have errors of 46% and 32 %. These high errors may be attributed to the counting statistics. These reaction rate values will be used to unfold the neutron spectrum of the CUF using the MAXED 2000, a computer code for the de convolution of multi sphere neutron spectrometer data and the results are discussed. The authors acknowledge help, advise, and using facility at ORNL-CUF to Dr. Rodger martin and Mr. David C. Galsgow.

  8. Measuring nuclear reaction cross sections to extract information on neutrinoless double beta decay

    Science.gov (United States)

    Cavallaro, M.; Cappuzzello, F.; Agodi, C.; Acosta, L.; Auerbach, N.; Bellone, J.; Bijker, R.; Bonanno, D.; Bongiovanni, D.; Borello-Lewin, T.; Boztosun, I.; Branchina, V.; Bussa, M. P.; Calabrese, S.; Calabretta, L.; Calanna, A.; Calvo, D.; Carbone, D.; Chávez Lomelí, E. R.; Coban, A.; Colonna, M.; D’Agostino, G.; De Geronimo, G.; Delaunay, F.; Deshmukh, N.; de Faria, P. N.; Ferraresi, C.; Ferreira, J. L.; Finocchiaro, P.; Fisichella, M.; Foti, A.; Gallo, G.; Garcia, U.; Giraudo, G.; Greco, V.; Hacisalihoglu, A.; Kotila, J.; Iazzi, F.; Introzzi, R.; Lanzalone, G.; Lavagno, A.; La Via, F.; Lay, J. A.; Lenske, H.; Linares, R.; Litrico, G.; Longhitano, F.; Lo Presti, D.; Lubian, J.; Medina, N.; Mendes, D. R.; Muoio, A.; Oliveira, J. R. B.; Pakou, A.; Pandola, L.; Petrascu, H.; Pinna, F.; Reito, S.; Rifuggiato, D.; Rodrigues, M. R. D.; Russo, A. D.; Russo, G.; Santagati, G.; Santopinto, E.; Sgouros, O.; Solakci, S. O.; Souliotis, G.; Soukeras, V.; Spatafora, A.; Torresi, D.; Tudisco, S.; Vsevolodovna, R. I. M.; Wheadon, R. J.; Yildirin, A.; Zagatto, V. A. B.

    2018-02-01

    Neutrinoless double beta decay (0vββ) is considered the best potential resource to access the absolute neutrino mass scale. Moreover, if observed, it will signal that neutrinos are their own anti-particles (Majorana particles). Presently, this physics case is one of the most important research “beyond Standard Model” and might guide the way towards a Grand Unified Theory of fundamental interactions. Since the 0vββ decay process involves nuclei, its analysis necessarily implies nuclear structure issues. In the NURE project, supported by a Starting Grant of the European Research Council (ERC), nuclear reactions of double charge-exchange (DCE) are used as a tool to extract information on the 0vββ Nuclear Matrix Elements. In DCE reactions and ββ decay indeed the initial and final nuclear states are the same and the transition operators have similar structure. Thus the measurement of the DCE absolute cross-sections can give crucial information on ββ matrix elements. In a wider view, the NUMEN international collaboration plans a major upgrade of the INFN-LNS facilities in the next years in order to increase the experimental production of nuclei of at least two orders of magnitude, thus making feasible a systematic study of all the cases of interest as candidates for 0vββ.

  9. Reaction-time-resolved measurements of laser-induced fluorescence in a shock tube with a single laser pulse

    Science.gov (United States)

    Zabeti, S.; Fikri, M.; Schulz, C.

    2017-11-01

    Shock tubes allow for the study of ultra-fast gas-phase reactions on the microsecond time scale. Because the repetition rate of the experiments is low, it is crucial to gain as much information as possible from each individual measurement. While reaction-time-resolved species concentration and temperature measurements with fast absorption methods are established, conventional laser-induced fluorescence (LIF) measurements with pulsed lasers provide data only at a single reaction time. Therefore, fluorescence methods have rarely been used in shock-tube diagnostics. In this paper, a novel experimental concept is presented that allows reaction-time-resolved LIF measurements with one single laser pulse using a test section that is equipped with several optical ports. After the passage of the shock wave, the reactive mixture is excited along the center of the tube with a 266-nm laser beam directed through a window in the end wall of the shock tube. The emitted LIF signal is collected through elongated sidewall windows and focused onto the entrance slit of an imaging spectrometer coupled to an intensified CCD camera. The one-dimensional spatial resolution of the measurement translates into a reaction-time-resolved measurement while the species information can be gained from the spectral axis of the detected two-dimensional image. Anisole pyrolysis was selected as the benchmark reaction to demonstrate the new apparatus.

  10. Laparoscopy After Previous Laparotomy

    Directory of Open Access Journals (Sweden)

    Zulfo Godinjak

    2006-11-01

    Full Text Available Following the abdominal surgery, extensive adhesions often occur and they can cause difficulties during laparoscopic operations. However, previous laparotomy is not considered to be a contraindication for laparoscopy. The aim of this study is to present that an insertion of Veres needle in the region of umbilicus is a safe method for creating a pneumoperitoneum for laparoscopic operations after previous laparotomy. In the last three years, we have performed 144 laparoscopic operations in patients that previously underwent one or two laparotomies. Pathology of digestive system, genital organs, Cesarean Section or abdominal war injuries were the most common causes of previouslaparotomy. During those operations or during entering into abdominal cavity we have not experienced any complications, while in 7 patients we performed conversion to laparotomy following the diagnostic laparoscopy. In all patients an insertion of Veres needle and trocar insertion in the umbilical region was performed, namely a technique of closed laparoscopy. Not even in one patient adhesions in the region of umbilicus were found, and no abdominal organs were injured.

  11. Measurement of the Induced Proton Polarization Pn in the 12C(e, e', p) reaction

    International Nuclear Information System (INIS)

    Woo, R.J.; Barkhuff, David; Bertozzi, William; Jian-ping Chen; Dan Dale; G. Dodson; K.A. Dow; Marty Epstein; Manouchehr Farkhondeh; Mike Finn; Shalev Gilad; Mark K. Jones; Kyungseon Joo; James Kelly; Stanley Kowalski; Bob Lourie; Richard Madey; Dimitri Margaziotis; Pete Markowitz; Justin McIntyre; Christoph Mertz; Brian Milbrath; Joseph Mitchell; Charles F. Perdrisat; Vina Punjabi; Paul Rutt; Adam Sarty; D. Tieger; C. Tschalaer; William Turchinetz; Paul E. Ulmer; S.P. Van Verst; C. Vellidis; Glen Warren; Lawrence Weinstein

    1998-01-01

    The first measurements of the induced proton polarization Pn for the 12C(e,e',p) reaction are reported. The experiment was performed at quasifree kinematics for energy and momentum transfer (w,q) = (294 MeV, 765 MeV/c) and sampled a missing momentum range of 0-250 MeV/c. The induced polarization arises from final-state interactions and for these kinematics is dominated by the real part of the spin-orbit optical potential. The distorted-wave impulse approximation provides good agreement with data for the 1 p3/2 shell. The data for the continuum suggest that both the 1s1/2 shell and underlying l > 1 configurations contribute

  12. Adobe Flash as a medium for online experimentation: a test of reaction time measurement capabilities.

    Science.gov (United States)

    Reimers, Stian; Stewart, Neil

    2007-08-01

    Adobe Flash can be used to run complex psychological experiments over the Web. We examined the reliability of using Flash to measure reaction times (RTs) using a simple binary-choice task implemented both in Flash and in a Linux-based system known to record RTs with millisecond accuracy. Twenty-four participants were tested in the laboratory using both implementations; they also completed the Flash version on computers of their own choice outside the lab. RTs from the trials run on Flash outside the lab were approximately 20 msec slower than those from trials run on Flash in the lab, which in turn were approximately 10 msec slower than RTs from the trials run on the Linux-based system (baseline condition). RT SDs were similar in all conditions, suggesting that although Flash may overestimate RTs slightly, it does not appear to add significant noise to the data recorded.

  13. Measurement of the spallation reaction 56Fe+p in inverse kinematics

    International Nuclear Information System (INIS)

    Boehmer, M.

    2006-01-01

    In this work the spallation reaction 56 Fe+p was investigated in inverse kinematics with regard to complete identification of the heavy residues. A ring imaging Cerenkov counter was used for velocity measurements in the experimental setup located at GSI in Darmstadt. A new fast readout electronic was developed and has been operated successfully in the experiment. Momentum reconstruction was carried out with the ALADiN spectrometer and a new software package written for this purpose. Cross sections and velocity distributions for more than 100 mass separated isotopes could be extracted from the dataset and compared with empirical models and other spallation experiments. The experiences gained in this experiment will be used for systematic improvements in the setup of the new spectrometer R3B at FAIR. (orig.)

  14. Four years of ozone measurements in the Central Amazon - Absorption mechanisms and reactions within the rainforest

    Science.gov (United States)

    Wolff, Stefan; Ganzeveld, Laurens; Tsokankunku, Anywhere; Saturno, Jorge; Souza, Rodrigo; Trebs, Ivonne; Sörgel, Matthias

    2017-04-01

    The ATTO (Amazon Tall Tower Observatory) site (02°08'38.8''S, 58°59'59.5''W) is located in the remote Amazon rainforest, allowing atmospheric and forest studies away from nearby anthropogenic emission sources. Starting with continuous measurements of vertical mixing ratio profiles of H2O, CO2 and O3 in April 2012 at 8 heights between 0.05 m and 80 m above ground, the longest continuous record of near surface O3 in the Amazon rainforest was established. Black carbon (BC), CO and micrometeorological measurements are available for the same period. During intensive campaigns, NOx was measured as well using the same profile system, and therefore several month of parallel NOx measurements are available. This data allows the analyses of diverse patterns regarding emission, deposition, turbulence and chemical reactions of trace gases within and above the rainforest for several rainy and dry seasons. The remote Amazon generally serves as a sink for O3 which is mainly deposited to the canopy. The deposition depends to a large extent on the aperture of the leaf stomata, which is correlated to temperature, humidity, solar radiation and water availability. Comparing these parameters with the in-canopy and above canopy gradients of O3, considering the turbulent conditions and further chemical reactions of O3 with NOx and VOC molecules, we estimated the role of the forest for the removal of ozone from the atmosphere under different meteorological conditions. We applied the Multi-Layer Canopy Chemical Exchange Model - MLC-CHEM to support the analysis of the observed profiles of NOx and O3. Under pristine conditions, the forest soil is the major source for NO emissions, which are directly reacting with O3 molecules, affecting the O3 gradient within the sub-canopy. We have analyzed differences between model and measurements in sub-canopy NO and O3 mixing ratios by the application of different NO soil emission scenarios and by the performance of several sensitivity analyses to

  15. Development, improvement and calibration of neutronic reaction rates measurements: elaboration of a standard techniques basis

    International Nuclear Information System (INIS)

    Hudelot, J.P.

    1998-06-01

    In order to improve and to validate the neutronics calculation schemes, perfecting integral measurements of neutronics parameters is necessary. This thesis focuses on the conception, the improvement and the development of neutronics reaction rates measurements, and aims at building a base of standard techniques. Two subjects are discussed. The first one deals with direct measurements by fission chambers. A short presentation of the different usual techniques is given. Then, those last ones are applied through the example of doubling time measurements on the EOLE facility during the MISTRAL 1 experimental programme. Two calibration devices of fission chambers are developed: a thermal column located in the central part of the MINERVE facility, and a calibration cell using a pulsed high flux neutron generator and based on the discrimination of the energy of the neutrons with a time-of-flight method. This second device will soon allow to measure the mass of fission chambers with a precision of about 1 %. Finally, the necessity of those calibrations will be shown through spectral indices measurements in core MISTRAL 1 (UO 2 ) and MISTRAL 2 (MOX) of the EOLE facility. In each case, the associated calculation schemes, performed using the Monte Carlo MCNP code with the ENDF-BV library, will be validated. Concerning the second one, the goal is to develop a method for measuring the modified conversion ratio of 238 U (defined as the ratio of 238 U capture rate to total fission rate) by gamma-ray spectrometry of fuel rods. Within the framework of the MISTRAL 1 and MISTRAL 2 programmes, the measurement device, the experimental results and the spectrometer calibration are described. Furthermore, the MCNP calculations of neutron self-shielding and gamma self-absorption are validated. It is finally shown that measurement uncertainties are better than 1 %. The extension of this technique to future modified conversion ratio measurements for 242 Pu (on MOX rods) and 232 Th (on

  16. Cold air challenge for measuring airway reactivity in children: lack of a late asthmatic reaction.

    Science.gov (United States)

    Varga, E M; Eber, E; Zach, M S

    1990-01-01

    Cold air challenge (CACh) for measuring airway reactivity uses respiratory heat or water loss as a bronchoconstrictor stimulus; this stimulus is also important for the development of exercise-induced asthma, for which late asthmatic reactions (LARs) have been described. At 1200 hr on day 1, 22 children with asthma started to record their peak expiratory flow rate (PEFR) in 3 hr intervals until 0900 hr on day 2. At 1000 hr, they underwent a standardized 4 min CACh. Children then inhaled salbutamol and continued to record PEFR until 0900 hr on day 3. As a bronchodilator effect, PEFR measurements were significantly higher 2, 5, and 8 hr after CACh, but subsequently did not differ significantly from pre-CACh values. At 5 hr after CACh, individual values ranged from 95 to 137% of the corresponding pre-CACh measurements, at 8 hr from 94 to 150%, and at 11 hr from 80 to 121%. This random sample of children with asthma demonstrated no LAR after CACh.

  17. Measurement of neutron-induced reactions on 242mAm

    Science.gov (United States)

    Buckner, M. Q.; Wu, C.-Y.; Henderson, R. A.; Bucher, B.; Chyzh, A.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; Ullmann, J. L.; Dance Collaboration

    2016-09-01

    Neutron-induced reaction cross sections of 242mAm were measured at the Los Alamos Neutron Science Center using the Detector for Advanced Neutron-Capture Experiments array along with a compact parallel-plate avalanche counter for fission-fragment detection. A new neutron-capture cross section was determined relative to a simultaneous measurement of the well-known 242mAm(n,f) cross section. The (n, γ) cross section was measured from thermal to an incident energy of 1 eV. Our new 242mAm fission cross section was normalized to ENDF/B-VII.1 and agreed well with the (n,f) cross section reported in the literature from thermal energy to 1 keV. The capture-to-fission ratio was determined from thermal energy to En = 0.1 eV, and it was found to be (n, γ)/(n,f) = 26(4)% compared to 19% from ENDF/B-VII.1. Our latest results will be reported. US Department of Energy by Lawrence Livermore National Security, LLC Contract DE-AC52-07NA27344 and Los Alamos National Security, LLC Contract DE-AC52-06NA25396 and U.S. DOE/NNSA Office of Defense Nuclear Nonproliferation Research and Development.

  18. Measurement of 6Li(n,α)3H reaction cross section

    International Nuclear Information System (INIS)

    Renner, C.

    1979-01-01

    The 6 Li(n,α) 3 H reaction cross section was measured at 12 discrete neutron energies between 80 KeV and 470 KeV by using the Oak Ridge Linear Acelerator (ORELA) as a pulsed neutron source. The neutron beam was filtered through 20 cm or 30 cm of Armco iron which produces several monoenergetic energies groups (iron windows) between 20 KeV and 1000 KeV about 2 KeV wide. The (n,α) events were detected by a 1 mm thick Li-glass scintillator and the neutron flux was measured with a NE110 plastic scintillator 6,6 cm thick and 10 cm in diameter. Multiple scattering corrections in the Li-glass and the NE110 scintillator efficiency were determined theoretically by using Monte Carlo technique. The 6 Li content in the Li-glasses was determined by transmission measurements with low energy neutrons. A theoretical fit was applied to the results by the R-matrix theory. (Author) [pt

  19. Measurement of the reaction anti pp→ΦΦ at the experiment JETSET

    International Nuclear Information System (INIS)

    Steinkamp, O.

    1994-02-01

    The experiment Jetset examines the reactions anti pp→ΦΦ with an internal target at LEAR (CERN), whereby the Φ mesons are each detected by their decay into two charged kaons. The theme of this thesis was the development of an evaluation chain for the reconstruction of events of the type anti pp→K + K - K + K - as well as the extraction of a signal of the resonant production anti pp→ΦΦ→/K + K - K + K - . Luminosities were determinded from the measurement of the known cross section for elastic anti pp scattering. Momentaneous luminosities of (3-4)x10 29 cm -2 s -1 resulted. The integrated measured luminosities for the single measuring points varied between 8 nb -1 and 32 nb -1 . Total ''ΦΦ yields'' were determined under the assumption of a flat differential cross section over the whole angular range to (1-2) μb. For partial ΦΦ yields in the confined polar angular range vertical stroke cos θ cm vertical stroke cm is indicated, as the fit by second-order polynomials to the angular distributions measured in the accessibler polar angular range shows. From the extrapolation of these polynomials into the not measured forward region total ΦΦ yields of (2-3) μb result. The study of the region around the ξ(2220) gave no significant hint to the presence of this resonance in the channel anti pp→ΦΦ. Upper limits on the product of the branching rations BR( anti pp→ξ)xBR(ξ→ΦΦ) were determined for different widths of a resonance ξ with a mass of 2.225 GeV/c 2 . At an assumed width od 15 MeV/c 2 upper limits of 8.5x10 -5 for a resonance with J=4 and of 1.5x10 -4 for a resonance with J=2 result

  20. Measurements of Volatile Organic Compounds Using Proton Transfer Reaction - Mass Spectrometry during the MILAGRO 2006 Campaign

    Science.gov (United States)

    Fortner, E. C.; Zheng, J.; Zhang, R.; Berk Knighton, W.; Volkamer, R. M.; Sheehy, P.; Molina, L.; André, M.

    2009-01-01

    Volatile organic compounds (VOCs) were measured by proton transfer reaction - mass spectrometry (PTR-MS) on a rooftop in the urban mixed residential and industrial area North Northeast of downtown Mexico City as part of the Megacity Initiative - Local and Global Research Observations (MILAGRO) 2006 field campaign. Thirty eight individual masses were monitored during the campaign and many species were quantified including methanol, acetaldehyde, toluene, the sum of C2 benzenes, the sum of C3 benzenes, acetone, isoprene, benzene, and ethyl acetate. The VOC measurements were analyzed to gain a better understanding of the type of VOCs present in the MCMA, their diurnal patterns, and their origins. Diurnal profiles of weekday and weekend/holiday aromatic VOC concentrations showed the influence of vehicular traffic during the morning rush hours and during the afternoon hours. Plumes including elevated toluene as high as 216 parts per billion (ppb) and ethyl acetate as high as 183 ppb were frequently observed during the late night and early morning hours, indicating the possibility of significant industrial sources of the two compounds in the region. Wind fields during those peak episodes revealed no specific direction for the majority of the toluene plumes but the ethyl acetate plumes arrived at the site when winds were from the Southwest or West. The PTR-MS measurements combined with other VOC measuring techniques at the field site as well as VOC measurements conducted in other areas of the Mexico City Metropolitan Area (MCMA) will help to develop a better understanding of the spatial pattern of VOCs and its variability in the MCMA.

  1. Laser Doppler imaging, thermographic imaging, and tissue oxygen saturation measurements detect early skin reactions during breast radiotherapy

    Science.gov (United States)

    Harrison, David K.; Harrison, Eileen M.; Newton, David J.; Windsor, Phyllis M.

    2001-05-01

    A range of acute skin reactions, ranging from mild erythema to moist desquamation, can be seen in patients receiving standard fractionated radiotherapy to the breast for conservation therapy of breast carcinoma. In a number of cases these reactions can cause considerable discomfort and seriously affect the patient's quality of life. In previous studies we have used the techniques of laser Doppler imaging, digital thermographic imaging and lightguide spectrophotometry to study oxygen supply and blood flow in inflammatory reactions induced experimentally in forearm skin. The present study is an attempt to use the same techniques to investigate whether any or all of them can detect changes in breast skin very early on in the course of radiotherapy treatment. A further aim of the longer term study is to investigate to what extent these early changes may be able to predict the occurrence later of severe acute or delayed reactions.

  2. Measurement of dabigatran: previously demonstrated Hemoclot® Thrombin Inhibitor assay reagent instability on Sysmex CS-2100i is no longer an issue

    DEFF Research Database (Denmark)

    Comuth, Willemijn; Faaborg, Louise; Henriksen, Linda Østervig

    2017-01-01

    package insert instructions (incubation time: 15 min). Stability was increased to five hours when following the application sheet (incubation time: 60 min). Two years later, the study was repeated using samples of patients treated with dabigatran etexilate. This time, reagent stability was at least six......The Hemoclot® Thrombin Inhibitor (HTI) assay has been recommended for measurement of dabigatran concentrations in specific clinical situations. Traditionally, reagents for biochemical assays are prepared from instructions found in the package insert. For the HTI reagents the manufacturer recommends...... incubating the reagents much longer than indicated in the package insert. These recommendations are added to the application sheets designed for different analyzers. Many clinicians and laboratory personnel may be unaware of the discrepancy between the two instructions, resulting in incorrect handling...

  3. Testing an ionization chamber with gaseous samples and measurements of the (n, alpha) reaction cross sections

    CERN Document Server

    Gledenov, Yu M; Salatskii, V I; Sedyshev, P V; Andrzejewski, J; Szalanski, P

    1999-01-01

    A new ionization chamber with gaseous samples (GIC) has been designed and tested on the thermal and resonance neutron beams of FLNP's neutron sources. The exposed gas volume serves as a target for neutrons. The obtained thermal cross sections for the sup 1 sup 7 O(n, alpha) sup 1 sup 4 C, sup 2 sup 1 Ne(n, alpha) sup 1 sup 8 O and sup 3 sup 6 Ar(n, alpha) sup 3 sup 3 S reactions are (233+-12) mb, (0.18+-0.09) mb and (5.43+-0.27) mb, respectively. These measurements have been performed on a pure beam of thermal neutrons from the high flux reactor IBR-2; and they demonstrated high efficiency and reliability of the method. Compared to samples on substrates, the application of gaseous samples makes the beam background essentially lower, and what is more important, the background component is totally absent due to the absence of Li and B microimpurities in gaseous samples while they do present in the samples on substrates. The method is also applicable to measurements with resonance neutrons. The recovery capabili...

  4. Measurement of the thermal cross section of the reaction 64Zn(n,γ)65Zn in a mixed neutron flux

    International Nuclear Information System (INIS)

    Dorval, E. L; Arribere, M. A; Ribeiro Guevara, S

    2006-01-01

    Zinc is an element that is present in a great variety of biological and geological samples.For its determination by Instrumental Neutron Activation Analysis, the reaction 64 Z n(n,γ) 6 5Zn is used, due to the long half life of the reaction product, the target's bigger isotopic abundance, and an easily measurable 1115 keV main gamma line.In a recent evaluation of thermal cross sections and resonance integrals, a thermal cross section value that is 44.7% bigger than the previous evaluation has been published by the same reference.This difference is not within reported uncertainties.Besides, the relative uncertainty of the new evaluation is much bigger than the one corresponding to the previous evaluation.The adoption of the thermal cross section corresponding to different evaluations may imply, in the case of an irradiation in the peripheral I 6 position at the R A-6 reactor, discrepancies of about 43% in the calculated concentrations.These inconsistencies were evident during the irradiation of certified standard materials.This motivated the measurement of the thermal cross section for the reaction 64 Z n(n,γ) 6 5Zn in the I 6 position at the R A-6 reactor.For the analysis of results, a code was written in order to calculate correction factors from an accurate characterization of the neutron spectrum.The thermal cross section value of the reaction 64 Z n(n,γ) 6 5Zn measured is (0.76± 0.03) b [es

  5. Reaction rate constants of H-abstraction by OH from large ketones: Measurements and site-specific rate rules

    KAUST Repository

    Badra, Jihad

    2014-01-01

    Reaction rate constants of the reaction of four large ketones with hydroxyl (OH) are investigated behind reflected shock waves using OH laser absorption. The studied ketones are isomers of hexanone and include 2-hexanone, 3-hexanone, 3-methyl-2-pentanone, and 4-methl-2-pentanone. Rate constants are measured under pseudo-first-order kinetics at temperatures ranging from 866 K to 1375 K and pressures near 1.5 atm. The reported high-temperature rate constant measurements are the first direct measurements for these ketones under combustion-relevant conditions. The effects of the position of the carbonyl group (CO) and methyl (CH3) branching on the overall rate constant with OH are examined. Using previously published data, rate constant expressions covering, low-to-high temperatures, are developed for acetone, 2-butanone, 3-pentanone, and the hexanone isomers studied here. These Arrhenius expressions are used to devise rate rules for H-abstraction from various sites. Specifically, the current scheme is applied with good success to H-abstraction by OH from a series of n-ketones. Finally, general expressions for primary and secondary site-specific H-abstraction by OH from ketones are proposed as follows (the subscript numbers indicate the number of carbon atoms bonded to the next-nearest-neighbor carbon atom, the subscript CO indicates that the abstraction is from a site next to the carbonyl group (CO), and the prime is used to differentiate different neighboring environments of a methylene group):P1,CO = 7.38 × 10-14 exp(-274 K/T) + 9.17 × 10-12 exp(-2499 K/T) (285-1355 K)S10,CO = 1.20 × 10-11 exp(-2046 K/T) + 2.20 × 10-13 exp(160 K/T) (222-1464 K)S11,CO = 4.50 × 10-11 exp(-3000 K/T) + 8.50 × 10-15 exp(1440 K/T) (248-1302 K)S11′,CO = 3.80 × 10-11 exp(-2500 K/T) + 8.50 × 10-15 exp(1550 K/T) (263-1370 K)S 21,CO = 5.00 × 10-11 exp(-2500 K/T) + 4.00 × 10-13 exp(775 K/T) (297-1376 K) © 2014 the Partner Organisations.

  6. Activation cross section measurement for the 179Hf(n,2n)178m2Hf reaction

    International Nuclear Information System (INIS)

    Yu Weixiang; Lu Hanlin; Zhao Wenrong

    1992-01-01

    As an important data for a fusion reactor there are not any experimental results for the cross section of the 179 Hf(n,2n) 178m2 Hf reaction. So the cross section was measured in this work at neutron energy of 14 MeV. Meanwhile, we also gave the data for the cross section of the 180 Hf(n,2n) 179m2 Hf reaction. (author). 5 refs, 4 figs, 5 tabs

  7. Optimization of Maillard Reaction between Glucosamine and Other Precursors by Measuring Browning with a Spectrophotometer.

    Science.gov (United States)

    Ogutu, Benrick; Kim, Ye-Joo; Kim, Dae-Wook; Oh, Sang-Chul; Hong, Dong-Lee; Lee, Yang-Bong

    2017-09-01

    The individual Maillard reactions of glucose, glucosamine, cyclohexylamine, and benzylamine were studied at a fixed temperature of 120°C under different durations by monitoring the absorbance of the final products at 425 nm. Glucosamine was the most individually reactive compound, whereas the reactions of glucose, cyclohexylamine, and benzylamine were not significantly different from each other. Maillard reactions of reaction mixtures consisting of glucosamine-cyclohexylamine, glucosamine-benzylamine, glucose-cyclohexylamine, and glucose-benzylamine were also studied using different concentration ratios under different durations at a fixed temperature of 120°C and pH 9. Maillard reactions in the pairs involving glucosamine were observed to be more intense than those of the pairs involving glucose. Finally, with respect to the concentration ratios, it was observed that in most instances, optimal activity was realized, when the reaction mixtures were in the ratio of 1:1.

  8. Implementation of a new data acquisition and exclusive measurement of the reaction vector pp → ppπ+π- at the time of flight spectrometer COSY-TOF

    International Nuclear Information System (INIS)

    Erhardt, Arthur

    2009-01-01

    The two-pion production pp ppπ + π - was measured exclusively at T p =793 MeV using the short version of the COSY-TOF spectrometer. In this measurement both the new EMS-based data acquisition system and a delayed pulse technique have been used, which, in addition to particle identification, energy, time of flight, and angle determination provides pi+ identification for pions in the theta lab range from 2 to 28 degrees. The measured total cross section for this reaction is σ=4.1(4) μb at T p =793 MeV. Due to an improved efficiency correction, the earlier measured total cross section has been corrected to σ=1.6 μb at T p =747 MeV. This value agrees nicely with the results from WASA/PROMICE. The data are compared to previous data and theoretical models which have been developed to understand the results from WASA/PROMICE measurements. The measurements have been carried out with transversally polarized proton beam which made it possible to determine analyzing powers for different subsystems of the two pion production reaction. In contrast to predictions we find significant analyzing power values up to A y =0.3. The data in the range of Roper excitation confirm that the dominating π π decay channel is N * →Nσ. (orig.)

  9. Measurement of the Residual Sodium and Reaction Compounds on a Cleaned Cold Trap

    International Nuclear Information System (INIS)

    Kim, Byung Ho; Jeong, Ji Young; Kim, Jong Man; Choi, Byung Hae; Nam, Ho Yun Nam

    2006-01-01

    The purpose of a cleaning process is to remove the residual sodium adhering to the component walls once it has been properly drained. It is necessary to clean and decontaminate a component, especially the large components of the primary coolant system; such as the intermediate heat exchangers and the primary pump. Improper and inadequate cleaning has in a number of cases resulted in problems in the storage, handling, and reuse of components. Inadequate and incomplete removal of sodium results in residues which may contain metallic sodium and alkaline compounds such as sodium hydroxide, sodium oxide, sodium carbonate, and various types of alcoholates. Reinsertion of components containing these compounds into a high-temperature sodium system can result in either a intergranular penetration characteristic of a high-oxygen sodium or an accelerated corrosion due to oxygen. Cleaning methods are needed that will avoid a deleterious local overheating, material surface degradation or deposits, a chemical, physical, or mechanical damage, and external effects. It is important to determine the levels of residual sodium that can be accepted so that those deleterious effects will not negate the reuse of the component. The purpose of this paper is to measure the amount of the sodium and the reaction compounds remaining on a component after a cleaning and prepare acceptable criteria for the reuse of components which have been subjected to a sodium cleaning

  10. Measurement of the Residual Sodium and Reaction Compounds on a Cleaned Cold Trap

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Byung Ho; Jeong, Ji Young; Kim, Jong Man; Choi, Byung Hae; Nam, Ho Yun Nam [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    2006-07-01

    The purpose of a cleaning process is to remove the residual sodium adhering to the component walls once it has been properly drained. It is necessary to clean and decontaminate a component, especially the large components of the primary coolant system; such as the intermediate heat exchangers and the primary pump. Improper and inadequate cleaning has in a number of cases resulted in problems in the storage, handling, and reuse of components. Inadequate and incomplete removal of sodium results in residues which may contain metallic sodium and alkaline compounds such as sodium hydroxide, sodium oxide, sodium carbonate, and various types of alcoholates. Reinsertion of components containing these compounds into a high-temperature sodium system can result in either a intergranular penetration characteristic of a high-oxygen sodium or an accelerated corrosion due to oxygen. Cleaning methods are needed that will avoid a deleterious local overheating, material surface degradation or deposits, a chemical, physical, or mechanical damage, and external effects. It is important to determine the levels of residual sodium that can be accepted so that those deleterious effects will not negate the reuse of the component. The purpose of this paper is to measure the amount of the sodium and the reaction compounds remaining on a component after a cleaning and prepare acceptable criteria for the reuse of components which have been subjected to a sodium cleaning.

  11. Spallation reactions and energy deposition in heavy target materials comparison of measurements and MC-calculations

    International Nuclear Information System (INIS)

    Filges, D.; Enke, M.; Galin, J.

    2001-01-01

    A renascence of interest for energetic proton induced production of neutrons originates recently by the inception of new projects for target stations of intense spallation neutron sources (like the planned European Spallation Source ESS), accelerator-driven nuclear reactors, nuclear waste transmutation and also the application for radioactive beams. Here we verify the predictive power of transport codes currently on the market by confronting observables and quantities of interest with an exhaustive matrix of benchmark data essentially coming from two experiments being performed at the Cooler Synchrotron COSY at Juelich. Program packages like HERMES, LCS or MCNPX master the prevision of reaction cross sections, hadronic interaction lengths, averaged neutron multiplicities and neutron multiplicity distributions in thick and thin(!) targets for a wide spectrum of incident proton energies, geometrical shapes and materials of the target. While also the observables related to the energy deposition in thick targets are in a good agreement with the model predictions, the production cross section measurements however for light charged particles on thin targets point out that problems exist within these models. (author)

  12. Measuring mental workload and physiological reactions in marine pilots: Building bridges towards redlines of performance.

    Science.gov (United States)

    Orlandi, Luca; Brooks, Benjamin

    2018-05-01

    This paper investigates the effects of shiphandling manoeuvres on mental workload and physiological reactions in ten marine pilots. Each pilot performed four berthings in a ship simulator. Those berthings were differentiated by two factors, level of difficulty and familiarity with the port. Each berthing could also be divided into five phases, three during the execution and two resting periods, one before and one after the execution (dedicated to baseline physiological data collection). Mental workload was measured through two self assessment scales: the NASA TLX and a Likert scale. Power spectral densities on Beta bands 1 and 2 were obtained from EEG. Heart rate and heart rate variability were obtained from ECG. Pupil dilation was obtained from eye tracking. Workload levels were higher as berthings increased in difficulty level and/or the pilots completed the berthings in unfamiliar ports. Responses differed across specific phases of the berthings. Physiological responses could indirectly monitor levels of mental workload, and could be adopted in future applications to evaluate training improvements and performance. This study provides an example of an applied methodology aiming to define an upper redline of task demands in the context of marine pilotage. Copyright © 2018. Published by Elsevier Ltd.

  13. Rate Coefficients of C1 and C2 Criegee Intermediate Reactions with Formic and Acetic Acid Near the Collision Limit: Direct Kinetics Measurements and Atmospheric Implications**

    Science.gov (United States)

    Welz, Oliver; Eskola, Arkke J; Sheps, Leonid; Rotavera, Brandon; Savee, John D; Scheer, Adam M; Osborn, David L; Lowe, Douglas; Murray Booth, A; Xiao, Ping; Anwar H Khan, M; Percival, Carl J; Shallcross, Dudley E; Taatjes, Craig A

    2014-01-01

    Rate coefficients are directly determined for the reactions of the Criegee intermediates (CI) CH2OO and CH3CHOO with the two simplest carboxylic acids, formic acid (HCOOH) and acetic acid (CH3COOH), employing two complementary techniques: multiplexed photoionization mass spectrometry and cavity-enhanced broadband ultraviolet absorption spectroscopy. The measured rate coefficients are in excess of 1×10−10 cm3 s−1, several orders of magnitude larger than those suggested from many previous alkene ozonolysis experiments and assumed in atmospheric modeling studies. These results suggest that the reaction with carboxylic acids is a substantially more important loss process for CIs than is presently assumed. Implementing these rate coefficients in global atmospheric models shows that reactions between CI and organic acids make a substantial contribution to removal of these acids in terrestrial equatorial areas and in other regions where high CI concentrations occur such as high northern latitudes, and implies that sources of acids in these areas are larger than previously recognized. PMID:24668781

  14. Rate coefficients of C(1) and C(2) Criegee intermediate reactions with formic and acetic Acid near the collision limit: direct kinetics measurements and atmospheric implications.

    Science.gov (United States)

    Welz, Oliver; Eskola, Arkke J; Sheps, Leonid; Rotavera, Brandon; Savee, John D; Scheer, Adam M; Osborn, David L; Lowe, Douglas; Murray Booth, A; Xiao, Ping; Anwar H Khan, M; Percival, Carl J; Shallcross, Dudley E; Taatjes, Craig A

    2014-04-25

    Rate coefficients are directly determined for the reactions of the Criegee intermediates (CI) CH2 OO and CH3 CHOO with the two simplest carboxylic acids, formic acid (HCOOH) and acetic acid (CH3 COOH), employing two complementary techniques: multiplexed photoionization mass spectrometry and cavity-enhanced broadband ultraviolet absorption spectroscopy. The measured rate coefficients are in excess of 1×10(-10)  cm(3)  s(-1) , several orders of magnitude larger than those suggested from many previous alkene ozonolysis experiments and assumed in atmospheric modeling studies. These results suggest that the reaction with carboxylic acids is a substantially more important loss process for CIs than is presently assumed. Implementing these rate coefficients in global atmospheric models shows that reactions between CI and organic acids make a substantial contribution to removal of these acids in terrestrial equatorial areas and in other regions where high CI concentrations occur such as high northern latitudes, and implies that sources of acids in these areas are larger than previously recognized. © 2014 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

  15. Measurement of Walking Ground Reactions in Real-Life Environments: A Systematic Review of Techniques and Technologies.

    Science.gov (United States)

    Shahabpoor, Erfan; Pavic, Aleksandar

    2017-09-12

    Monitoring natural human gait in real-life environments is essential in many applications, including quantification of disease progression, monitoring the effects of treatment, and monitoring alteration of performance biomarkers in professional sports. Nevertheless, developing reliable and practical techniques and technologies necessary for continuous real-life monitoring of gait is still an open challenge. A systematic review of English-language articles from scientific databases including Scopus, ScienceDirect, Pubmed, IEEE Xplore, EBSCO and MEDLINE were carried out to analyse the 'accuracy' and 'practicality' of the current techniques and technologies for quantitative measurement of the tri-axial walking ground reactions outside the laboratory environment, and to highlight their strengths and shortcomings. In total, 679 relevant abstracts were identified, 54 full-text papers were included in the paper and the quantitative results of 17 papers were used for meta-analysis and comparison. Three classes of methods were reviewed: (1) methods based on measured kinematic data; (2) methods based on measured plantar pressure; and (3) methods based on direct measurement of ground reactions. It was found that all three classes of methods have competitive accuracy levels with methods based on direct measurement of the ground reactions showing highest accuracy while being least practical for long-term real-life measurement. On the other hand, methods that estimate ground reactions using measured body kinematics show highest practicality of the three classes of methods reviewed. Among the most prominent technical and technological challenges are: (1) reducing the size and price of tri-axial load-cells; (2) improving the accuracy of orientation measurement using IMUs; (3) minimizing the number and optimizing the location of required IMUs for kinematic measurement; (4) increasing the durability of pressure insole sensors, and (5) enhancing the robustness and versatility of the

  16. Measurement of Walking Ground Reactions in Real-Life Environments: A Systematic Review of Techniques and Technologies

    Directory of Open Access Journals (Sweden)

    Erfan Shahabpoor

    2017-09-01

    Full Text Available Monitoring natural human gait in real-life environments is essential in many applications, including quantification of disease progression, monitoring the effects of treatment, and monitoring alteration of performance biomarkers in professional sports. Nevertheless, developing reliable and practical techniques and technologies necessary for continuous real-life monitoring of gait is still an open challenge. A systematic review of English-language articles from scientific databases including Scopus, ScienceDirect, Pubmed, IEEE Xplore, EBSCO and MEDLINE were carried out to analyse the ‘accuracy’ and ‘practicality’ of the current techniques and technologies for quantitative measurement of the tri-axial walking ground reactions outside the laboratory environment, and to highlight their strengths and shortcomings. In total, 679 relevant abstracts were identified, 54 full-text papers were included in the paper and the quantitative results of 17 papers were used for meta-analysis and comparison. Three classes of methods were reviewed: (1 methods based on measured kinematic data; (2 methods based on measured plantar pressure; and (3 methods based on direct measurement of ground reactions. It was found that all three classes of methods have competitive accuracy levels with methods based on direct measurement of the ground reactions showing highest accuracy while being least practical for long-term real-life measurement. On the other hand, methods that estimate ground reactions using measured body kinematics show highest practicality of the three classes of methods reviewed. Among the most prominent technical and technological challenges are: (1 reducing the size and price of tri-axial load-cells; (2 improving the accuracy of orientation measurement using IMUs; (3 minimizing the number and optimizing the location of required IMUs for kinematic measurement; (4 increasing the durability of pressure insole sensors, and (5 enhancing the robustness and

  17. Light particle emission measurements in heavy ion reactions: Progress report, June 1, 1987-May 31, 1988

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1988-01-01

    This paper discusses work on heavy ion reactions done at Georgia State University. Topics and experiments discussed are: energy division in damped reactions between 58 Ni projectiles and 165 Ho and 58 Ni targets using time-of-flight methods; particle-particle correlations; and development works on the Hili detector system. 10 refs., 9 figs

  18. Study of the Kinetics of an S[subscript N]1 Reaction by Conductivity Measurement

    Science.gov (United States)

    Marzluff, Elaine M.; Crawford, Mary A.; Reynolds, Helen

    2011-01-01

    Substitution reactions, a central part of organic chemistry, provide a model system in physical chemistry to study reaction rates and mechanisms. Here, the use of inexpensive and readily available commercial conductivity probes coupled with computer data acquisition for the study of the temperature and solvent dependence of the solvolysis of…

  19. Calibration and intercomparison of acetic acid measurements using proton transfer reaction mass spectrometry (PTR-MS)

    Science.gov (United States)

    Haase, K.B.; Keene, W.C.; Pszenny, A.A.P.; Mayne, H.R.; Talbot, R.W.; Sive, B.C.

    2012-01-01

    Acetic acid is one of the most abundant organic acids in the ambient atmosphere, with maximum mixing ratios reaching into the tens of parts per billion by volume (ppbv) range. The identities and associated magnitudes of the major sources and sinks for acetic acid are poorly characterized, due in part to the limitation in available measurement techniques. This paper demonstrates that Proton Transfer Reaction Mass Spectrometry (PTR-MS) can reliably quantify acetic acid vapor in ambient air. Three different PTR-MS configurations were calibrated at low ppbv mixing ratios using permeation tubes, which yielded calibration factors between 7.0 and 10.9 normalized counts per second per ppbv (ncps ppbv−1) at a drift tube field strength of 132 townsend (Td). Detection limits ranged from 0.06 to 0.32 ppbv with dwell times of 5 s. These calibration factors showed negligible humidity dependence. Using the experimentally determined calibration factors, PTR-MS measurements of acetic acid during the International Consortium for Atmospheric Research on Transport and Transformation (ICARTT) campaign were validated against results obtained using Mist Chambers coupled with Ion Chromatography (MC/IC). An orthogonal least squares linear regression of paired data yielded a slope of 1.14 ± 0.06 (2σ), an intercept of 0.049 ± 20 (2σ) ppbv, and an R2 of 0.78. The median mixing ratio of acetic acid on Appledore Island, ME during the ICARTT campaign was 0.530 ± 0.025 ppbv with a minimum of 0.075 ± 0.004 ppbv, and a maximum of 3.555 ± 0.171 ppbv.

  20. Measurement of cross-sections of yttrium (n,xn) threshold reactions by means of gamma spectroscopy

    CERN Document Server

    Chudoba, Petr; Wagner, V; Vrzalova, J; Svoboda, O; Majerle, M; Stefanik, M; Suchopar, M; Kugler, A; Bielewicz, M; Strugalska-Gola, E; Szuta, M; Hervas, D; Herman, T; Geier, B

    2014-01-01

    Neutron activation and gamma spectrometry are usable also f or the determination of cross-sections of different neutron reactions. We have studied the cross-sections of yttrium (n, x n) threshold reactions using quasi-monoenergetic neutron source based on the reaction on 7 Li target at Nuclear Physics Institute of ASCR in Rez. Yttrium (n, x n) threshold reactions are suitable candidates for fast neutron field measurement by activation detectors. Fast neutron field monitoring is necessary already today at a wide range of accelerator facilities and will gain on importance in future fast reactors of generation IV, accelerator transmutation systems or fusion reactors. The knowledge of the cross-sections is crucial for such purpose. Unfortunately, the cross-section is sufficiently known only for 89 Y(n,2n) 88 Y reaction. For higher orders of reactions there are almost no experimental data. Special attention was paid to t he 89 Y(n,3n) 87 Y reaction. The cross-sections of both 89 Y(n,2n) 88 Y and 89 Y(n,3n) 87 Y re...

  1. Design of an experimental device dedicated to the measurement of spallation reactions; Mise au point d'un dispositif experimental pour des mesures exclusives des reactions de spallation

    Energy Technology Data Exchange (ETDEWEB)

    Lafriakh, A

    2005-12-15

    Spallation mechanisms are not yet completely understood, especially because of the difficulty of experimentally disentangling the effects of the different steps of the reaction. In order to understand these mechanisms, we have developed a new experimental device able to perform inclusive measurements. We propose a detection system based on a combination of ionization chambers and proportional counters and on a wall of plastic scintillators to measure light charged particles. In particular the detection of light charged particles is described in detail. In order to validate our device, we have compared our preliminary results obtained on the Fe{sup 56} + p system at 1 GeV/u with inclusive measurements previously obtained at the FRS spectrometer of the GSI facility. A comparison of charge differential cross section shows reasonable agreement. However, our new device allowed extension of those measurements down to Z = 1 and Z = 2. These cross sections are important for material damage studies. Taking into account our error brackets, the evolution of mean longitudinal velocities with respect to residue masses is comparable to that obtained at the FRS. These first results, although preliminary, allow us to validate our experimental device. It is now possible to exploit the strong points of our exclusive measurements, namely correlations between different measured observables. Finally, experimental problems encountered will be taken into account in the future experimental programs, in order to ensure the best measurements conditions.

  2. Direct measurement of the 7Be(n, α4 He reaction cross sections for the cosmological Li problem

    Directory of Open Access Journals (Sweden)

    Kawabata Takahiro

    2017-01-01

    Full Text Available The cross sections of the 7Be(n, α4He reaction for p-wave neutrons were experimentally determined at Ec.m. = 0.20−0.81 MeV close to the Big Bang nucleosynthesis (BBN energy window for the first time on the basis of the detailed balance principle by measuring the time-reverse reaction. The obtained cross sections are much larger than the cross sections for s-wave neutrons inferred from the recent measurement at the n_TOF facility in CERN, but significantly smaller than the theoretical estimation widely used in the BBN calculations. The present results suggest the 7Be(n, α4 He reaction rate is not large enough to solve the cosmological lithium problem

  3. Extracting integrated and differential cross sections in low energy heavy-ion reactions from backscattering measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sargsyan, V. V. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Yerevan State University, 0025 Yerevan (Armenia); Adamian, G. G., E-mail: adamian@theor.jinr.ru [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Antonenko, N. V. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Mathematical Physics Department, Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Diaz-Torres, A. [European Centre for Theoretical Studies in Nuclear Physics and Related Areas, I-38123 Villazzano, Trento (Italy); Gomes, P. R. S. [de Fisica, Universidade Federal Fluminense, Av. Litorânea, s/n, Niterói, R.J. 24210-340 (Brazil); Lenske, H. [Institut für Theoretische Physik der Justus–Liebig–Universität, D–35392 Giessen (Germany)

    2016-07-07

    We suggest new methods to extract elastic (quasi-elastic) scattering angular distribution and reaction (capture) cross sections from the experimental elastic (quasi-elastic) backscattering excitation function taken at a single angle.

  4. Verification of dosimetry cross sections above 10 MeV based on measurement of activation reaction rates in fission neutron field

    International Nuclear Information System (INIS)

    Odano, Naoteru; Miura, Toshimasa; Yamaji, Akio.

    1996-01-01

    To validate the dosimetry cross sections in fast neutron energy range, activation reaction rates were measured for 5 types of dosimetry cross sections which have sensitivity in the energy rage above 10 MeV utilizing JRR-4 reactor of JAERI. The measured reaction rates were compared with the calculations reaction rates by a continuous energy monte carlo code MVP. The calculated reaction rates were based on two dosimetry files, JENDL Dosimetry File and IRDF-90.2. (author)

  5. Validation of reaction time as a measure of cognitive function and quality of life in healthy subjects and patients

    DEFF Research Database (Denmark)

    Jakobsen, Lene Holm; Sorensen, Janice Marie; Rask, Ingeborg Krarup

    2011-01-01

    Malnutrition is a common problem in hospitalized patients and is related to decreased cognitive function and impaired quality of life (QoL). We investigated the validity of reaction time as a simple bedside tool for measuring cognitive function in healthy subjects and patients, and additionally...

  6. Measurements of thermal neutron cross section and resonance integral for the 237Np(n,γ)238Np reaction

    International Nuclear Information System (INIS)

    Kobayashi, Katsuhei; Yamanaka, Akihiro; Kimura, Itsuro

    1994-01-01

    Making use of a standard neutron spectrum field with a pure Maxwellian distribution at the heavy water thermal neutron facility of the Kyoto University Reactor (KUR), the thermal neutron cross section for the 237 Np(n,γ) 238 Np reaction was measured by the activation method, using a high purity Ge detector. The result is 158 ± 3 b, which is obtained relative to the reference value of 98.65 ± 0.09 b for the 197 Au(n,γ) 198 Au reaction. The present value is lower by about 13% than that of the ENDF/B-VI data. The data given by Mughabghab and obtained from JENDL-3 are larger by 11 to 14% than the present measurement. The resonance integral for the 237 Np(n,γ) 238 Np reaction was measured with a 1/E standard neutron spectrum in the cavity of the central graphite reflector region between the two-divided cores of the Kinki University Reactor (UTR-KINK), relative to the reference value of 1,550 ± 28 b for the 197 Au(n,γ) 198 Au reaction. By defining the Cd cut-off energy as 0.5 eV, the present resonance integral is 652 ± 24 b, which is in good agreement with the JENDL-3, ENDF/B-VI and Mughabghab data. However, most of the old experimental data are, in general, larger by 24 to 38% than the present measurement

  7. Measurement and calculation of cross section for (p,x) reactions on natural Fe for 650 MeV protons

    International Nuclear Information System (INIS)

    Janczyszyn, J.; Pohorecki, W.; Domanska, G.; Loska, L.; Taczanowski, S.; Shvetsov, V.

    2006-01-01

    Cross sections for production of radionuclides in (p,x) reactions on natural iron were measured for protons of 650 ± 4 MeV with the use of HPGe gamma spectrometry and calculated with the MCNPX code. The determined cross section values were compared with the computed and other experimental ones

  8. Measurements of spectroscopic factors in 61Ni by the (d,p) reaction below the Coulomb barrier

    International Nuclear Information System (INIS)

    Baghdadi, A.; Seltz, R.; Magnac-Valette, D.; Bonneaud, G.; Gerardin, C.

    1975-01-01

    Spectroscopic factors for the two most strongly excited e=0 and e=2 states in 61 Ni have been measured by the (d,p) reaction in subcoulombic conditions. The results confirm a close to 50% missing strength for the filling of the 3ssub(1/2) and 2d orbitals in 61 Ni [fr

  9. Integral measurement of the $^{12}$C(n,p)$^{12}$B reaction up to 10 GeV

    CERN Document Server

    Žugec, P; Bosnar, D; Ventura, A; Mengoni, A; Altstadt, S; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Bečvář, F; Belloni, F; Berthoumieux, E; Billowes, J; Boccone, V; Brugger, M; Calviani, M; Calviño, F; Cano-Ott, D; Carrapiço, C; Cerutti, F; Chiaveri, E; Chin, M; Cortés, G; Cortés-Giraldo, M.A; Cosentino, L; Diakaki, M; Domingo-Pardo, C; Dressler, R; Duran, I; Eleftheriadis, C; Ferrari, A; Finocchiaro, P; Fraval, K; Ganesan, S; García, A R; Giubrone, G; Gómez-Hornillos, M B; Gonçalves, I F; González-Romero, E; Griesmayer, E; Guerrero, C; Gunsing, F; Gurusamy, P; Heinitz, S; Jenkins, D G; Jericha, E; Käppeler, F; Karadimos, D; Kivel, N; Kokkoris, M; Krtička, M; Kroll, J; Langer, C; Lederer, C; Leeb, H; Leong, L S; Meo, S Lo; Losito, R; Manousos, A; Marganiec, J; Martínez, T; Massimi, C; Mastinu, P; Mastromarco, M; Mendoza, E; Milazzo, P M; Mingrone, F; Mirea, M; Mondalaers, W; Musumarra, A; Paradela, C; Pavlik, A; Perkowski, J; Plompen, A; Praena, J; Quesada, J; Rauscher, T; Reifarth, R; Riego, A; Roman, F; Rubbia, C; Sarmento, R; Saxena, A; Schillebeeckx, P; Schmidt, S; Schumann, D; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Tsinganis, A; Valenta, S; Vannini, G; Variale, V; Vaz, P; Versaci, R; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiß, C; Wright, T

    2016-01-01

    The integral measurement of the $^{12}$C(n,p)$^{12}$B reaction was performed at the neutron time of flight facility n_TOF at CERN. The total number of $^{12}$B nuclei produced per neutron pulse of the n_TOF beam was determined using the activation technique in combination with a time of flight technique. The cross section is integrated over the n_TOF neutron energy spectrum from reaction threshold at 13.6 MeV to 10 GeV. Having been measured up to 1 GeV on basis of the $^{235}$U(n,f) reaction, the neutron energy spectrum above 200 MeV has been reevaluated due to the recent extension of the cross section reference for this particular reaction, which is otherwise considered a standard up to 200 MeV. The results from the dedicated GEANT4 simulations have been used to evaluate the neutron flux from 1 GeV up to 10 GeV. The experimental results related to the $^{12}$C(n,p)$^{12}$B reaction are compared with the evaluated cross sections from major libraries and with the predictions of different GEANT4 models, which m...

  10. Measurements of activation reaction rate distributions on a mercury target bombarded with high-energy protons at AGS

    Energy Technology Data Exchange (ETDEWEB)

    Takada, Hiroshi; Kasugai, Yoshimi; Nakashima, Hiroshi; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Ino, Takashi; Kawai, Masayoshi [High Energy Accelerator Research Organization, Tsukuba, Ibaraki (Japan); Jerde, Eric; Glasgow, David [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    2000-02-01

    A neutronics experiment was carried out using a thick mercury target at the Alternating Gradient Synchrotron (AGS) facility of Brookhaven National Laboratory in a framework of the ASTE (AGS Spallation Target Experiment) collaboration. Reaction rate distributions around the target were measured by the activation technique at incident proton energies of 1.6, 12 and 24 GeV. Various activation detectors such as the {sup 115}In(n,n'){sup 115m}In, {sup 93}Nb(n,2n){sup 92m}Nb, and {sup 209}Bi(n,xn) reactions with threshold energies ranging from 0.3 to 70.5 MeV were employed to obtain the reaction rate data for estimating spallation source neutron characteristics of the mercury target. It was found from the measured {sup 115}In(n,n'){sup 115m}In reaction rate distribution that the number of leakage neutrons becomes maximum at about 11 cm from the top of hemisphere of the mercury target for the 1.6-GeV proton incidence and the peak position moves towards forward direction with increase of the incident proton energy. The similar result was observed in the reaction rate distributions of other activation detectors. The experimental procedures and a full set of experimental data in numerical form are summarized in this report. (author)

  11. Measurements of activation reaction rate distributions on a mercury target bombarded with high-energy protons at AGS

    International Nuclear Information System (INIS)

    Takada, Hiroshi; Kasugai, Yoshimi; Nakashima, Hiroshi; Ikeda, Yujiro; Jerde, Eric; Glasgow, David

    2000-02-01

    A neutronics experiment was carried out using a thick mercury target at the Alternating Gradient Synchrotron (AGS) facility of Brookhaven National Laboratory in a framework of the ASTE (AGS Spallation Target Experiment) collaboration. Reaction rate distributions around the target were measured by the activation technique at incident proton energies of 1.6, 12 and 24 GeV. Various activation detectors such as the 115 In(n,n') 115m In, 93 Nb(n,2n) 92m Nb, and 209 Bi(n,xn) reactions with threshold energies ranging from 0.3 to 70.5 MeV were employed to obtain the reaction rate data for estimating spallation source neutron characteristics of the mercury target. It was found from the measured 115 In(n,n') 115m In reaction rate distribution that the number of leakage neutrons becomes maximum at about 11 cm from the top of hemisphere of the mercury target for the 1.6-GeV proton incidence and the peak position moves towards forward direction with increase of the incident proton energy. The similar result was observed in the reaction rate distributions of other activation detectors. The experimental procedures and a full set of experimental data in numerical form are summarized in this report. (author)

  12. Measurement of the 1H(γ, p)π0 reaction using a novel nucleon spin polarimeter.

    Science.gov (United States)

    Sikora, M H; Watts, D P; Glazier, D I; Aguar-Bartolomé, P; Akasoy, L K; Annand, J R M; Arends, H J; Bantawa, K; Beck, R; Bekrenev, V S; Berghäuser, H; Braghieri, A; Branford, D; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F B; Demissie, B T; Downie, E J; Drexler, P; Fil'kov, L V; Freehart, B; Gregor, R; Hamilton, D; Heid, E; Hornidge, D; Howdle, D A; Jaegle, I; Jahn, O; Jude, T C; Kashevarov, V L; Keshelashvili, I; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A A; Kruglov, S P; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J D; Maghrbi, Y; Manley, D M; Marinides, Z; Martinez, M; McGeorge, J C; McKinnon, B; McNicoll, E F; Mekterovic, D; Metag, V; Micanovic, S; Middleton, D G; Mushkarenkov, A; Nefkens, B M K; Nikolaev, A; Novotny, R; Ostrick, M; Otte, P B; Oussena, B; Pedroni, P; Pheron, F; Polonski, A; Prakhov, S; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sober, D I; Starostin, A; Strakovsky, I I; Suarez, I M; Supek, I; Thiel, M; Thomas, A; Unverzagt, M; Werthmüller, D; Workman, R L; Zamboni, I; Zehr, F

    2014-01-17

    We report the first large-acceptance measurement of polarization transfer from a polarized photon beam to a recoiling nucleon. The measurement pioneers a novel polarimetry technique, which can be applied to many other nuclear and hadron physics experiments. The commissioning reaction of 1H(γ, p)π0 in the range 0.4

  13. Direct measurements of OH and other product yields from the HO2  + CH3C(OO2 reaction

    Directory of Open Access Journals (Sweden)

    F. A. F. Winiberg

    2016-03-01

    Full Text Available The reaction CH3C(OO2 + HO2  →  CH3C(OOOH + O2 (Reaction R5a, CH3C(OOH + O3 (Reaction R5b, CH3 + CO2 + OH + O2 (Reaction R5c was studied in a series of experiments conducted at 1000 mbar and (293 ± 2 K in the HIRAC simulation chamber. For the first time, products, (CH3C(OOOH, CH3C(OOH, O3 and OH from all three branching pathways of the reaction have been detected directly and simultaneously. Measurements of radical precursors (CH3OH, CH3CHO, HO2 and some secondary products HCHO and HCOOH further constrained the system. Fitting a comprehensive model to the experimental data, obtained over a range of conditions, determined the branching ratios α(R5a  =  0.37 ± 0.10, α(R5b =  0.12 ± 0.04 and α(R5c =  0.51 ± 0.12 (errors at 2σ level. Improved measurement/model agreement was achieved using k(R5  =  (2.4 ± 0.4  ×  10−11 cm3 molecule−1 s−1, which is within the large uncertainty of the current IUPAC and JPL recommended rate coefficients for the title reaction. The rate coefficient and branching ratios are in good agreement with a recent study performed by Groß et al. (2014b; taken together, these two studies show that the rate of OH regeneration through Reaction (R5 is more rapid than previously thought. GEOS-Chem has been used to assess the implications of the revised rate coefficients and branching ratios; the modelling shows an enhancement of up to 5 % in OH concentrations in tropical rainforest areas and increases of up to 10 % at altitudes of 6–8 km above the equator, compared to calculations based on the IUPAC recommended rate coefficient and yield. The enhanced rate of acetylperoxy consumption significantly reduces PAN in remote regions (up to 30 % with commensurate reductions in background NOx.

  14. Resonance Strength Measurement at Astrophysical Energies: The 17O(p,α14N Reaction Studied via THM

    Directory of Open Access Journals (Sweden)

    Sergi M.L.

    2016-01-01

    Full Text Available In recent years, the Trojan Horse Method (THM has been used to investigate the low-energy cross sections of proton-induced reactions on 17O nuclei, overcoming extrapolation procedures and enhancement effects due to electron screening. We will report on the indirect study of the 17O(p,α14N reaction via the Trojan Horse Method by applying the approach developed for extracting the resonance strength of narrow resonance in the ultralow energy region. The mean value of the strengths obtained in the two measurements was calculated and compared with the direct data available in literature.

  15. A millifluidic calorimeter with InfraRed thermography for the measurement of chemical reaction enthalpy and kinetics

    OpenAIRE

    Hany, Cindy; Pradere, Christophe; Toutain, Jean; Batsale, Jean-Christophe

    2012-01-01

    International audience; The aim of this work is to present an infrared calorimeter for the measurement of the kinetics and the enthalpy of high exothermic chemical reactions. The main idea is to use a millifluidic chip where the channel acts as a chemical reactor. An infrared camera is used to deduce the heat flux produced by the chemical reaction from the processing of temperature fields. Due to the size of the microchannel, a small volume of reagents (ml) is used. As the chemical reagents a...

  16. Oxygen 18 concentration profile measurements near the surface by 18O(p,α)15N resonance reaction

    International Nuclear Information System (INIS)

    Amsel, G.; David, D.

    1975-01-01

    The method of spectrum reduction in nuclear reaction microanalysis does not allow to obtain depth resolutions better than the order of 2000A. Resolutions of the order of 200A may be obtained by using the narrow resonance technique, when applied to thin films. The latter technique was extended to thick targets, with deep concentration profiles presenting a sharp gradient near the surface. This method is presented and illustrated by the study of 18 O profiles in oxygen diffusion measurements in growing ZrO 2 , using the 629keV resonance of the reaction 18 O(p,α) 15 N [fr

  17. Measurement of weak rates for stellar evolution via the (t,3He) reaction

    International Nuclear Information System (INIS)

    Zegers, R.G.T.

    2007-01-01

    The (t, 3 He) charge-exchange reaction has been developed as a tool to extract Gamow-Teller strengths on nuclei of importance for stellar evolution. A secondary triton beam of 115 MeV/nucleon is used, either produced from a primary α beam, or, since recently, from a primary 16 O beam. Here, the (t, 3 He) reaction is used to study the Gamow-Teller strength distribution in 58 Co via the 58 Ni(t, 3 He) reaction. The experimental results are compared with calculations in large-scale shell models using the kb3g and gxpf1 interactions, as well as existing data from 58 Ni(n, p) and 58 Ni(d, 2 He) experiments. The differences between the data and theoretical models are studied in terms of electron-capture rates in the pre-collapse stages of core-collapse supernovae

  18. Estimation of the rate of volcanism on Venus from reaction rate measurements

    Science.gov (United States)

    Fegley, Bruce, Jr.; Prinn, Ronald G.

    1989-01-01

    Laboratory rate data for the reaction between SO2 and calcite to form anhydrite are presented. If this reaction rate represents the SO2 reaction rate on Venus, then all SO2 in the Venusian atmosphere will disappear in 1.9 Myr unless volcanism replenishes the lost SO2. The required volcanism rate, which depends on the sulfur content of the erupted material, is in the range 0.4-11 cu km of magma erupted per year. The Venus surface composition at the Venera 13, 14, and Vega 2 landing sites implies a volcanism rate of about 1 cu km/yr. This geochemically estimated rate can be used to determine if either (or neither) of two discordant geophysically estimated rates is correct. It also suggests that Venus may be less volcanically active than the earth.

  19. Measurement of Neutron Reaction Cross Sections in Carbon using a Single Crystal Diamond Detector

    Energy Technology Data Exchange (ETDEWEB)

    Pillon, M.; Angelone, M. [Associazione EURATOM-ENEA sulla Fusione, ENEA C.R. Frascati, via E. Fermi, 45 0044 Frascati, Rome (Italy); Krasa, A.; Plompen, A. J. M.; Schillebeeckx, P. [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements, - 2440 Geel (Belgium); Sergi, M. L. [Dipartimento di Fisica e Astronomia, Universita di Catania e INFN-Laboratori Nazionali del Sud, Catania (Italy)

    2011-12-13

    A single crystal diamond detector was exposed to the quasi mono-energetic neutron fields in the energy range from 7 MeV to 20.5 MeV produced by the Van de Graaff neutron generator of the EC-JRC-IRMM. Pulse Height Spectra (PHS) of the neutron interaction with the diamond (carbon) were recorded in order to derive the experimental response function of this detector to neutrons in view of its use as a compact fast neutron spectrometer. Several peaks produced by outgoing charged particles produced when neutrons interact with carbon were identified using the reaction Q-values. The corresponding nuclear reactions, such as (n,{alpha}), (n,p), (n,d) for different excitation states were identified in the PHS. The analysis of the peaks allows the derivation of some neutron reaction cross sections in carbon. The results are presented in this paper together with the associated uncertainties.

  20. Measurement of Neutron Reaction Cross Sections in Carbon using a Single Crystal Diamond Detector

    Science.gov (United States)

    Pillon, M.; Angelone, M.; Krása, A.; Plompen, A. J. M.; Schillebeeckx, P.; Sergi, M. L.

    2011-12-01

    A single crystal diamond detector was exposed to the quasi mono-energetic neutron fields in the energy range from 7 MeV to 20.5 MeV produced by the Van de Graaff neutron generator of the EC-JRC-IRMM. Pulse Height Spectra (PHS) of the neutron interaction with the diamond (carbon) were recorded in order to derive the experimental response function of this detector to neutrons in view of its use as a compact fast neutron spectrometer. Several peaks produced by outgoing charged particles produced when neutrons interact with carbon were identified using the reaction Q-values. The corresponding nuclear reactions, such as (n,α), (n,p), (n,d) for different excitation states were identified in the PHS. The analysis of the peaks allows the derivation of some neutron reaction cross sections in carbon. The results are presented in this paper together with the associated uncertainties.

  1. Incomplete fusion reactions in 16O+159Tb system: Spin distribution measurements

    Directory of Open Access Journals (Sweden)

    Sharma Vijay R.

    2015-01-01

    Full Text Available In order to explore the reaction modes on the basis of their entry state spin population, an experiment has been done by employing particle-γ coincidence technique carried out at the Inter University Accelerator Centre, New Delhi. The preliminary analysis conclusively demonstrates, spin distribution for some reaction products populated via complete and/or incomplete fusion of 16O with 159Tb system found to be distinctly different. Further, the existence of incomplete fusion at low bombarding energies indicates the possibility to populate high spin states.

  2. Reaction rate constant of HO2+O3 measured by detecting HO2 from photofragment fluorescence

    Science.gov (United States)

    Manzanares, E. R.; Suto, Masako; Lee, Long C.; Coffey, Dewitt, Jr.

    1986-01-01

    A room-temperature discharge-flow system investigation of the rate constant for the reaction 'HO2 + O3 yields OH + 2O2' has detected HO2 through the OH(A-X) fluorescence produced by photodissociative excitation of HO2 at 147 nm. A reaction rate constant of 1.9 + or - 0.3 x 10 to the -15th cu cm/molecule per sec is obtained from first-order decay of HO2 in excess O3; this agrees well with published data.

  3. A compact Ultra High Vacuum (UHV) compatible instrument for time of flight energy measurements of slow heavy reaction products

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, A.V. [V.G.Khlopin Radium Institute, St. Petersburg (Russian Federation); Uppsala Univ. (Sweden). The Svedberg Lab.; Veldhuizen, E.J. van; Aleklett, K. [Uppsala Univ., (Sweden). Dept. of Radiation Sciences; Westerberg, L. [Uppsala University (Sweden). The Svedberg Lab.; Lyapin, V.G. [V.G.Khlopin Radium Institute, St. Petersburg (Russian Federation); Loveland, W. [Oregon State Univ., Corvallis, OR (United States). Dept. of Chemistry; Bondorf, J. [Niels Bohr Inst., Copenhagen (Denmark); Jakobsson, B. [Lund Univ. (Sweden). Dept. of Physics; Whitlow, H.J. [Lund Univ. (Sweden). Dept. of Nuclear Physics; Bouanani, M. El [Lund Univ. (Sweden). Dept. of Nuclear Physics; Univ. of North Texas, Denton, TX (United States). Dept. of Physics

    2000-07-01

    A compact Ultra High Vacuum (UHV) compatible instrument for time of flight energy measurements of slow heavy reaction products from nuclear reactions has been designed and tested at the CELSIUS storage ring in Uppsala. The construction is based on MicroChannel Plate time detectors of the electron mirror type and silicon p-i-n diodes, and permits the detectors to be stacked side-by-side to achieve large solid angle coverage. This kind of telescope measures the Time of Flight (ToF) and Energy (E) of the particle from which one can reconstruct mass. The combination of an ultra-thin cluster gas-jet target and thin carbon emitter foils allows one to measure heavy residues down to an energy of {approx} 35 keV/nucleon from the interactions of 400 MeV/nucleon {sup 16}O with {sup nat} Xe gas targets.

  4. Measurement of cross section and astrophysical factor of the d(d,p)t reaction using the Trojan Horse Method

    Science.gov (United States)

    Rinollo, A.; Romano, S.; Spitaleri, C.; Bonomo, C.; Cherubini, S.; Del Zoppo, A.; Figuera, P.; La Cognata, M.; Lamia, L.; Musumarra, A.; et al.

    2005-07-01

    Knowledge about reactions involving deuterium is required for a correct understanding of stellar and primordial nucleosynthesis processes, and also in planning fusion reactors for energy production. We have studied the d(d,p)t reaction in the energy range from 1.5 MeV down to astrophysical energies by means of the Trojan Horse Method applied to the three-body 6Li(d,pt)α reaction, at a beam energy of 14 MeV. Protons and tritons have been detected in coincidence and identified. Quasi-free events have been kinematically selected, in order to extract the cross section and the astrophysical factor, and compare them with the values measured for the direct d(d,p)t process.

  5. Measurement of cross section and astrophysical factor of the d(d,p)t reaction using the Trojan Horse Method

    International Nuclear Information System (INIS)

    Rinollo, A.; Romano, S.; Spitaleri, C.; Bonomo, C.; Cherubini, S.; Del Zoppo, A.; Figuera, P.; La Cognata, M.; Lamia, L.; Musumarra, A.; Pellegriti, M.G.; Pizzone, R.G.; Rolfs, C.; Schuermann, D.; Strieder, F.; Tudisco, S.; Tumino, A.

    2005-01-01

    Knowledge about reactions involving deuterium is required for a correct understanding of stellar and primordial nucleosynthesis processes, and also in planning fusion reactors for energy production. We have studied the d(d,p)t reaction in the energy range from 1.5 MeV down to astrophysical energies by means of the Trojan Horse Method applied to the three-body 6 Li(d,pt)α reaction, at a beam energy of 14 MeV. Protons and tritons have been detected in coincidence and identified. Quasi-free events have been kinematically selected, in order to extract the cross section and the astrophysical factor, and compare them with the values measured for the direct d(d,p)t process

  6. Measurement of cross section and astrophysical factor of the d(d,p)t reaction using the Trojan Horse Method

    Energy Technology Data Exchange (ETDEWEB)

    Rinollo, A. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy)]|[Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy); Romano, S. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy)]|[Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy); Spitaleri, C. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy)]|[Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy); Bonomo, C. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy)]|[Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy); Cherubini, S. [Ruhr-Universitaet Bochum (Germany); Del Zoppo, A.; Figuera, P. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy); La Cognata, M. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy)]|[Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy); Lamia, L.; Musumarra, A.; Pellegriti, M.G. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy)]|[Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy); Pizzone, R.G. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy); Rolfs, C.; Schuermann, D.; Strieder, F. [Ruhr-Universitaet Bochum (Germany); Tudisco, S.; Tumino, A. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy)]|[Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy)

    2005-07-25

    Knowledge about reactions involving deuterium is required for a correct understanding of stellar and primordial nucleosynthesis processes, and also in planning fusion reactors for energy production. We have studied the d(d,p)t reaction in the energy range from 1.5 MeV down to astrophysical energies by means of the Trojan Horse Method applied to the three-body {sup 6}Li(d,pt){alpha} reaction, at a beam energy of 14 MeV. Protons and tritons have been detected in coincidence and identified. Quasi-free events have been kinematically selected, in order to extract the cross section and the astrophysical factor, and compare them with the values measured for the direct d(d,p)t process.

  7. Phosphorus-31 NMR magnetization transfer measurements of metabolic reaction rates in the rat heart and kidney in vivo

    International Nuclear Information System (INIS)

    Koretsky, A.P.

    1984-01-01

    31 P NMR is a unique tool to study bioenergetics in living cells. The application of magnetization transfer techniques to the measurement of steady-state enzyme reaction rates provides a new approach to understanding the regulation of high energy phosphate metabolism. This dissertation is concerned with the measurement of the rates of ATP synthesis in the rat kidney and of the creatine kinase catalyzed reaction in the rat heart in situ. The theoretical considerations of applying magnetization transfer techniques to intact organs are discussed with emphasis on the problems associated with multiple exchange reactions and compartmentation of reactants. Experimental measurements of the ATP synthesis rate were compared to whole kidney oxygen consumption and Na + reabsorption rates to derive ATP/O values. The problems associated with ATP synthesis rate measurements in kidney, e.g. the heterogeneity of the inorganic phosphate resonance, are discussed and experiments to overcome these problems proposed. In heart, the forward rate through creatine kinase was measured to be larger than the reverse rate. To account for the difference in forward and reverse rates a model is proposed based on the compartmentation of a small pool of ATP

  8. Measurement of the differential and total cross sections of the γ d →K0Λ (p ) reaction within the resonance region

    Science.gov (United States)

    Compton, N.; Taylor, C. E.; Hicks, K.; Cole, P.; Zachariou, N.; Ilieva, Y.; Nadel-Turonski, P.; Klempt, E.; Nikonov, V. A.; Sarantsev, A. V.; Adhikari, K. P.; Adhikari, S.; Akbar, Z.; Anefalos Pereira, S.; Avakian, H.; Baltzell, N. A.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Camp, M.; Cao, Frank Thanh; Cao, T.; Carman, D. S.; Celentano, A.; Charles, G.; Chetry, T.; Ciullo, G.; Clark, L.; Cole, P. L.; Contalbrigo, M.; Cortes, O.; Crede, V.; D'Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Filippi, A.; Fleming, J. A.; Fradi, A.; Gavalian, G.; Ghandilyan, Y.; Giovanetti, K. L.; Girod, F. X.; Glazier, D. I.; Gleason, C.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Heddle, D.; Holtrop, M.; Hughes, S. M.; Hyde, C. E.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jenkins, D.; Jo, H. S.; Joo, K.; Joosten, S.; Keller, D.; Khachatryan, G.; Khachatryan, M.; Khandaker, M.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuleshov, S. V.; Lanza, L.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; McKinnon, B.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Movsisyan, A.; Munevar, E.; Munoz Camacho, C.; Murdoch, G.; Nadel-Turonski, P.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Paremuzyan, R.; Park, K.; Pasyuk, E.; Phelps, W.; Pisano, S.; Pogorelko, O.; Price, J. W.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Ripani, M.; Ritchie, B. G.; Rizzo, A.; Rosner, G.; Sabatié, F.; Salgado, C.; Schumacher, R. A.; Sharabian, Y. G.; Simonyan, A.; Skorodumina, Iu.; Smith, G. D.; Sokhan, D.; Sparveris, N.; Stankovic, I.; Stepanyan, S.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Torayev, B.; Trivedi, A.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Wood, M. H.; Zachariou, N.; Zhang, J.; CLAS Collaboration

    2017-12-01

    We report the first measurement of differential and total cross sections for the γ d →K0Λ (p ) reaction, using data from the CLAS detector at the Thomas Jefferson National Accelerator Facility. Data collected during two separate experimental runs were studied with photon-energy coverage 0.8-3.6 GeV and 0.5- 2.6 GeV, respectively. The two measurements are consistent giving confidence in the method and determination of systematic uncertainties. The cross sections are compared with predictions from the KAON-MAID theoretical model (without kaon exchange), which deviate from the data at higher W and at forward kaon angles. These data, along with previously published cross sections for K+Λ photoproduction, provide essential constraints on the nucleon resonance spectrum. A first partial wave analysis was performed that describes the data without the introduction of new resonances.

  9. Small leak detection by measuring surface oscillation during sodium-water reaction in steam generator

    International Nuclear Information System (INIS)

    Nei, Hiromichi; Hori, Masao

    1977-01-01

    Small leak sodium-water reaction tests were conducted to develop various kinds of leak detectors for the sodium-heated steam generator in FBR. The super-heated steam was injected into sodium in a reaction vessel having a sodium free surface, simulating the steam generator. The level gauge in the reaction vessel generated the most reliable signal among detectors, as long as the leak rates were relatively high. The level gauge signal was estimated to be the sodium surface oscillation caused by hydrogen bubbles produced in sodium-water reaction. Experimental correlation was derived, predicting the amplitude as a function of leak rate, hydrogen dissolution ratio, bubble rise velocity and other parameters concerned, assuming that the surface oscillation is in proportion to the gas hold-up. The noise amplitude under normal operation without water leak was increased with sodium flow rate and found to be well correlated with Froud number. These two correlations predict that a water leak in a ''MONJU'' class (300 MWe) steam generator could possibly be detected by level gauges at a leak rate above 2 g/sec. (auth.)

  10. Employing Magnetic Levitation to Monitor Reaction Kinetics and Measure Activation Energy

    Science.gov (United States)

    Benz, Lauren; Cesafsky, Karen E.; Le, Tran; Park, Aileen; Malicky, David

    2012-01-01

    This article describes a simple and inexpensive undergraduate-level kinetics experiment that uses magnetic levitation to monitor the progress and determine the activation energy of a condensation reaction on a polymeric solid support. The method employs a cuvette filled with a paramagnetic solution positioned between two strong magnets. The…

  11. Stability results for a reaction-diffusion system with a single measurement

    Energy Technology Data Exchange (ETDEWEB)

    Ramoul, Hichem [Centre universitaire de Khenchela, Route de Batna, BP 1252, Liberte, 40004 Khenchela (Algeria); Gaitan, Patricia [Laboratoire d' analyse, topologie, probabilites CNRS UMR 6632, Marseille (France) and Universite Aix-Marseille II (France); Cristofol, Michel [Laboratoire d' analyse, topologie, probabilites CNRS UMR 6632, Marseille, France and Universite Aix-Marseille III (France)

    2007-06-15

    For a two by two reaction-diffusion system on a bounded domain we give a simultaneous stability result for one coefficient and for the initial conditions. The key ingredient is a global Carleman-type estimate with a single observation acting on a subdomain.

  12. A New Proxy Measurement Algorithm with Application to the Estimation of Vertical Ground Reaction Forces Using Wearable Sensors.

    Science.gov (United States)

    Guo, Yuzhu; Storm, Fabio; Zhao, Yifan; Billings, Stephen A; Pavic, Aleksandar; Mazzà, Claudia; Guo, Ling-Zhong

    2017-09-22

    Measurement of the ground reaction forces (GRF) during walking is typically limited to laboratory settings, and only short observations using wearable pressure insoles have been reported so far. In this study, a new proxy measurement method is proposed to estimate the vertical component of the GRF (vGRF) from wearable accelerometer signals. The accelerations are used as the proxy variable. An orthogonal forward regression algorithm (OFR) is employed to identify the dynamic relationships between the proxy variables and the measured vGRF using pressure-sensing insoles. The obtained model, which represents the connection between the proxy variable and the vGRF, is then used to predict the latter. The results have been validated using pressure insoles data collected from nine healthy individuals under two outdoor walking tasks in non-laboratory settings. The results show that the vGRFs can be reconstructed with high accuracy (with an average prediction error of less than 5.0%) using only one wearable sensor mounted at the waist (L5, fifth lumbar vertebra). Proxy measures with different sensor positions are also discussed. Results show that the waist acceleration-based proxy measurement is more stable with less inter-task and inter-subject variability than the proxy measures based on forehead level accelerations. The proposed proxy measure provides a promising low-cost method for monitoring ground reaction forces in real-life settings and introduces a novel generic approach for replacing the direct determination of difficult to measure variables in many applications.

  13. Rate Coefficient Measurements and Theoretical Analysis of the OH + ( E) CF3CH=CHCF3 Reaction.

    Science.gov (United States)

    Baasandorj, Munkhbayar; Marshall, Paul; Waterland, Robert L; Ravishankara, Akkihebbal R; Burkholder, James B

    2018-04-25

    Rate coefficients, k, for the gas-phase reaction of the OH radical with (E) CF3CH=CHCF3 ((E)-1,1,14,4,4-hexafluoro-2-butene, HFO-1336mzz(E)) were measured over a range of temperature (211-374 K) and bath gas pressure (20-300 Torr; He, N2) using a pulsed laser photolysis-laser induced fluorescence (PLP-LIF) technique. k1(T) was independent of pressure over this range of conditions with k1(296 K) = (1.31 ± 0.15) × 10 13 cm3 molecule 1 s 1 and k1(T) = (6.94 ± 0.80) × 10 13 exp[ (496 ± 10)/T] cm3 molecule 1 s 1, where the uncertainties are 2 and the pre-exponential term includes estimated systematic error. Rate coefficients for the OD reaction were also determined over a range of temperature (262-374 K) at 100 Torr (He). The OD rate coefficients were ~15% greater than the OH values and showed similar temperature dependent behavior with k2(T) = (7.52 ± 0.44) × 10 13 exp[ (476 ± 20)/T] and k2(296 K) = (1.53 ± 0.15) × 10 13 cm3 molecule 1 s 1. The rate coefficients for reaction 1 were also measured using a relative rate technique between 296 and 375 K with k1(296 K) measured to be (1.22 ± 0.1) × 10 13 cm3 molecule 1 s 1 in agreement with the PLP-LIF results. In addition, the 296 K rate coefficient for the O3 + (E) CF3CH=CHCF3 reaction was determined to be reaction and the significant decrease in OH reactivity compared to the (Z) CF3CH=CHCF3 stereoisomer reaction. The estimated atmospheric lifetime of (E) CF3CH=CHCF3, due to loss by reaction with OH, is estimated to be ~90 days, while the actual lifetime will depend on the location and season of its emission. Infrared absorption spectra of (E) CF3CH=CHCF3 were measured and used to estimate the 100-year time horizon global warming potentials (GWP) of 32 (atmospherically well-mixed) and 14 (lifetime-adjusted).

  14. Measurements of the 12C(a,g)16O reaction in higher energy off-resonance regions

    Science.gov (United States)

    Deboer, R. J.; Boeltzig, A.; Burcher, S. P.; Febbraro, M.; Jones, K.; Macon, K. T.; O'Malley, P.; Smith, K.; Thornsberry, C. R.; Wiescher, M.

    2017-09-01

    The 12C(α , γ) 16O reaction is one of the most important for the field of nuclear astrophysics for it strongly influences how stars of all types evolve over multiple stages of their life cycles. After 40+ years of measurements, significant improvement in our understanding of the reaction has been achieved, yet the desired level of uncertainty remains just out of reach. In this talk I will discuss new measurements of the 12C(α , γ) 16O reaction, over a higher energy range than usually investigated. These measurements were made using an array of LaBr3 detectors (part of the HAGRiD array) at the University of Notre Dame's nuclear science laboratory. I will explore why these measurements, made in primarily higher energy off-resonance regions, are useful in constraining the extrapolation of the cross section to the low energies that correspond to stellar burning temperatures (Ec . m . 300 keV). This work is supported by the National Science Foundation by Grant PHY-1419765 and the Joint Institute of Nuclear Astrophysics Center for the Evolution of the Elements Grant PHY-1430152.

  15. Measurement of the rates of reaction of the ground and metastable excited states of 02+, N0+ and 0+ with atmospheric gases at thermal energy

    International Nuclear Information System (INIS)

    Glosik, J.; Rakshit, A.B.; Twiddy, N.D.; Adams, N.G.; Smith, D.

    1978-01-01

    Thermal-energy reaction rate coefficients and product ion distributions have been measured for reactions of both the ground state and metastable electronic states of 0 2 + , N0 + and 0 + with several neutral species, using a selected-ion flow tube. In general the excited-ion reaction rates are fast, frequently approaching the Langevin limit. Collisional quenching occurs for the reactions of N0 + sup(star) with N 2 ,0 2 and H 2 and the quenching rates have been determined. The ion source also provided a substantial yield of doubly charged 0 2 permitting some measurements of reaction rates of 0 2 2+ . (author)

  16. Light particle emission measurements in heavy ion reactions. Final report, June 1, 1981-May 31, 1984

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1984-01-01

    Progress in instrumentation development reported includes improvements in the design of position sensitive neutron detectors, design of a thin-walled, spherical, aluminum target chamber, and use of thin silicon detectors to detect and identify evaporation residues from fusion reactions. The problem of the short lifetime of evaporation residue detectors is addressed by using a pair of large area, multi-wire proportional counters followed by a thin sheet of plastic scintillator. Neutron emission associated with fission has been studied, as well as nonequilibrium emission associated with inelastic products and evaporation residue. An experiment was performed to study neutron emission associated with fission and fission-like events in the case of the Er composite system. Other work in progress includes neutron emissions from the C + Gd and Ne + Nd reactions. 9 refs

  17. Measurement of (n,Xn) reaction cross sections at 96 MeV; Measure des sections efficaces (n,Xn) a 96 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Sagrado Garcia, Melle Inmaculada C. [Ecole Doctorale: SINEM, U.F.R. de Sciences, Universite de Caen/Basse-Normandie, Esplanade Paix14000 Caen (France)

    2006-10-15

    Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n,Xn) reactions in this energy range. Neutron double differential cross section measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL Laboratory in Uppsala, Sweden. The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 angle - 98 angle). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100) MeV. The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparison between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its treatment of nucleon-nucleon reactions. (author)

  18. Light particle and gamma ray emission measurements in heavy ion reactions. Progress report

    International Nuclear Information System (INIS)

    Petitt, G.A.

    1983-01-01

    Studies of neutron and charged particle emission in heavy ion reactions using the facilities at the HHIRF and the new computer facilities at Georgia State are briefly described. A progress report for 1982 to 1983 is combined with a proposal for work to be performed during 1983 to 1984. Present activities and immediate plans for a run already approved by the Program Advisory Committee of the HHIRF are discussed

  19. Cross-Section Measurements of (n, xn) Threshold Reactions in Au, Bi, I, In and Ta

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Ondřej; Vrzalová, J.; Wagner, Vladimír; Krása, Antonín; Kugler, Andrej; Majerle, Mitja

    2011-01-01

    Roč. 59, č. 2 (2011), s. 1709-1712 ISSN 0374-4884 R&D Projects: GA MŠk LC07050 Institutional research plan: CEZ:AV0Z10480505 Keywords : Energy plus transmutation * (n, xn) reaction * Quasi-monoenergetic neutron source * Cross-section Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 0.447, year: 2011

  20. The application of nuclear cross section measurements to spallation reactions in cosmic rays

    International Nuclear Information System (INIS)

    Raisbeck, G.M.; Yiou, F.

    1976-01-01

    The effects and implications of nuclear transformations of the comic ray particles themselves, and how those transformations are simulated in the laboratory are dealt with. Thus, although the majority of cosmic rays are protons and alpha particles, it is the small fraction of heavier species that is the main concern here. These nuclides interact with the interstellar matter (again mostly hydrogen and helium) in which they propagate, and thus can undergo nuclear reactions. For the cosmic ray physicist the effects of these reactions are both favourable and unfavourable. The unfavourable aspect arises from the fact that the composition of the cosmic ray is significantly altered, thus tending to mask an important indication as to their origin. Counterbalancing this is the fact that the effects left by the nuclear reactions are one of the most valuable links with the propagation process itself. A careful unravelling of these effects can thus reveal important information on where and how this propagation takes place. The type of nuclear information needed and techniques that are used to obtain it are considered. (Auth.)

  1. Charge-exchange and fusion reaction measurements during compression experiments with neutral beam heating in the Tokamak Fusion Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kaita, R.; Heidbrink, W.W.; Hammett, G.W.; Chan, A.A.; England, A.C.; Hendel, H.W.; Medley, S.S.; Nieschmidt, E.; Roquemore, A.L.; Scott, S.D.

    1986-04-01

    Adiabatic toroidal compression experiments were performed in conjunction with high power neutral beam injection in the Tokamak Fusion Test Reactor (TFTR). Acceleration of beam ions to energies nearly twice the injection energy was measured with a charge-exchange neutral particle analyzer. Measurements were also made of 2.5 MeV neutrons and 15 MeV protons produced in fusion reactions between the deuterium beam ions and the thermal deuterium and /sup 3/He ions, respectively. When the plasma was compressed, the d(d,n)/sup 3/He fusion reaction rate increased a factor of five, and the /sup 3/He(d,p)/sup 4/He rate by a factor of twenty. These data were simulated with a bounce-averaged Fokker-Planck program, which assumed conservation of angular momentum and magnetic moment during compression. The results indicate that the beam ion acceleration was consistent with adiabatic scaling.

  2. Direct Measurement of the 21Na(p, γ)22Mg Reaction: Resonance Strengths and Gamma-Gamma Analysis

    International Nuclear Information System (INIS)

    Trinczek, M.; Jewett, C.C.; D'Auria, J.M.; Bishop, S.; Buchmann, L.; Chen, A.A.; Engel, S.; Gigliotti, D.; Greife, U.; Hunter, D.; Hussein, A.; Hutcheon, D.; Jose, J.; Laird, A.M.; Lamey, M.; Lewis, R.; Olin, A.; Ottewel, D.; Parker, P.; Pavan, M.M.; Pearson, J.E.; Rogers, J.; Ruiz, C.; Wrede, C.

    2005-01-01

    A series of astrophysical measurements was recently completed at TRIUMF, related to the unknown total rate of the 21 Na(p, γ) 22 Mg reaction. With a high intensity 21 Na beam from the ISAC facility, the DRAGON recoil mass spectrometer was used to directly measure seven resonances at center of mass energies from E c.m. =200 to 1135 keV and determine their respective contributions to the 21 Na(p, γ) 22 Mg reaction rate in novae and x-ray bursts, as well as their impact on 22 Na production in novae. This study also allowed the investigation of different excited states in 22 Mg; proposed decays and spin assignments are given for the 6246, 6329, and 6609 keV levels

  3. Charge-exchange and fusion reaction measurements during compression experiments with neutral beam heating in the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Kaita, R.; Heidbrink, W.W.; Hammett, G.W.

    1986-04-01

    Adiabatic toroidal compression experiments were performed in conjunction with high power neutral beam injection in the Tokamak Fusion Test Reactor (TFTR). Acceleration of beam ions to energies nearly twice the injection energy was measured with a charge-exchange neutral particle analyzer. Measurements were also made of 2.5 MeV neutrons and 15 MeV protons produced in fusion reactions between the deuterium beam ions and the thermal deuterium and 3 He ions, respectively. When the plasma was compressed, the d(d,n) 3 He fusion reaction rate increased a factor of five, and the 3 He(d,p) 4 He rate by a factor of twenty. These data were simulated with a bounce-averaged Fokker-Planck program, which assumed conservation of angular momentum and magnetic moment during compression. The results indicate that the beam ion acceleration was consistent with adiabatic scaling

  4. Measurement of angle-correlated differential (n,2n) reaction cross section with pencil-beam DV neutron source

    International Nuclear Information System (INIS)

    Takaki, S.; Kondo, K.; Shido, S.; Miyamaru, H.; Murata, I.; Ochiai, Kentaro; Nishitani, Takeo

    2006-01-01

    Angle-correlated differential cross-section for 9 Be(n,2n) reaction has been measured with the coincidence detection technique and a pencil-beam DT neutron source at FNS, JAEA. Energy spectra of two emitted neutrons were obtained for azimuthal and polar direction independently. It was made clear from the experiment that there are noise signals caused by inter-detector scattering. The ratio of the inter-detector scattering components in the detected signals was estimated by MCNP calculation to correct the measured result. By considering the inter-detector scattering components, the total 9 Be(n,2n) reaction cross-section agreed with the evaluated nuclear data within the experimental error. (author)

  5. Measurements of neutron cross section of the {sup 243}Am(n,{gamma}){sup 244}Am reaction

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukawa, Yuichi; Shinohara, Nobuo; Hata, Kentaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-03-01

    The effective thermal neutron cross section of {sup 243}Am(n,{gamma}){sup 244}Am reaction was measured by the activation method. Highly-purified {sup 243}Am target was irradiated in an aluminum capsule by using a research reactor JRR-3M. The tentative effective thermal neutron cross sections are 3.92 b, and 84.44 b for the production of {sup 244g}Am and {sup 244m}Am, respectively. (author)

  6. Measurement of the polarization transfer coefficient K sub LS in the p vectorp yields d vector. pi. sup + reaction

    Energy Technology Data Exchange (ETDEWEB)

    Abegg, R.; Green, P.W.; Greeniaus, L.G.; Hutcheon, D.A. (TRIUMF, Vancouver, British Columbia (Canada) Centre for Subatomic Research, Univ. Alberta, Edmonton (Canada)); Yanlin, Y.; Korkmaz, E.; Mack, D.; Moss, G.A.; Olsen, W.C. (Centre for Subatomic Research, Univ. Alberta, Edmonton (Canada)); Stevenson, N.R. (Dept. of Physics, Univ. Saskatchewan, Saskatoon (Canada))

    1992-04-06

    We have measured the polarization transfer asymmetries of the reaction p vectorp{yields}d vector{pi}{sup +} from the longitudinally polarized proton to the sideways polarized deuteron for deuteron center-of-mass angles from 25deg to 140deg. Our longitudinal to sideways polarization transfer data are best represented by the partial-wave amplitude fits of Bugg et al. while several model calculations are only in qualitative agreement. (orig.).

  7. Measurement of the polarization transfer coefficient KLS in the p vectorp→d vectorπ+ reaction

    International Nuclear Information System (INIS)

    Abegg, R.; Green, P.W.; Greeniaus, L.G.; Hutcheon, D.A.; Yanlin, Y.; Korkmaz, E.; Mack, D.; Moss, G.A.; Olsen, W.C.; Stevenson, N.R.

    1992-01-01

    We have measured the polarization transfer asymmetries of the reaction p vectorp→d vectorπ + from the longitudinally polarized proton to the sideways polarized deuteron for deuteron center-of-mass angles from 25deg to 140deg. Our longitudinal to sideways polarization transfer data are best represented by the partial-wave amplitude fits of Bugg et al. while several model calculations are only in qualitative agreement. (orig.)

  8. First Ground-Based Infrared Solar Absorption Measurements of Free Tropospheric Methanol (CH3OH): Multidecade Infrared Time Series from Kitt Peak (31.9 deg N 111.6 deg W): Trend, Seasonal Cycle, and Comparison with Previous Measurements

    Science.gov (United States)

    Rinsland, Curtis P.; Mahieu, Emmanuel; Chiou, Linda; Herbin, Herve

    2009-01-01

    Atmospheric CH3OH (methanol) free tropospheric (2.09-14-km altitude) time series spanning 22 years has been analyzed on the basis of high-spectral resolution infrared solar absorption spectra of the strong vs band recorded from the U.S. National Solar Observatory on Kitt Peak (latitude 31.9degN, 111.6degW, 2.09-km altitude) with a 1-m Fourier transform spectrometer (FTS). The measurements span October 1981 to December 2003 and are the first long time series of CH3OH measurements obtained from the ground. The results were analyzed with SFIT2 version 3.93 and show a factor of three variations with season, a maximum at the beginning of July, a winter minimum, and no statistically significant long-term trend over the measurement time span.

  9. $^7Be(n,\\alpha)^4He$ reaction and the Cosmological Lithium Problem: measurement of the cross section in a wide energy range at n_TOF (CERN)

    CERN Document Server

    Barbagallo, M.; Cosentino, L.; Maugeri, E.; Heinitz, S.; Mengoni, A.; Dressler, R.; Schumann, D.; Käppeler, F.; Colonna, N.; Finocchiaro, P.; Ayranov, M.; Damone, L.; Kivel, N.; Aberle, O.; Altstadt, S.; Andrzejewski, J.; Audouin, L.; Bacak, M.; Balibrea-Correa, J.; Barros, S.; Bécares, V.; Bečvář, F.; Beinrucker, C.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brugger, M.; Caamaño, M.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Cardella, R.; Casanovas, A.; Castelluccio, D. M.; Cerutti, F.; Chen, Y. H.; Chiaveri, E.; Cortés, G.; Cortés-Giraldo, M. A.; Cristallo, S.; Diakaki, M.; Domingo-Pardo, C.; Dupont, E.; Duran, I.; Fernandez-Dominguez, B.; Ferrari, A.; Ferreira, P.; Furman, W.; Ganesan, S.; García-Rios, A.; Gawlik, A.; Glodariu, T.; Göbel, K.; Gonçalves, I. F.; González-Romero, E.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Harada, H.; Heftrich, T.; Heyse, J.; Jenkins, D. G.; Jericha, E.; Katabuchi, T.; Kavrigin, P.; Kimura, A.; Kokkoris, M.; Krtička, M.; Leal-Cidoncha, E.; Lerendegui, J.; Lederer, C.; Leeb, H.; Lo Meo, S.; Lonsdale, S. J.; Losito, R.; Macina, D.; Marganiec, J.; Martínez, T.; Massimi, C.; Mastinu, P.; Mastromarco, M.; Mazzone, A.; Mendoza, E.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Montesano, S.; Nolte, R.; Oprea, A.; Pappalardo, A.; Patronis, N.; Pavlik, A.; Perkowski, J.; Piscopo, M.; Plompen, A.; Porras, I.; Praena, J.; Quesada, J.; Rajeev, K.; Rauscher, T.; Reifarth, R.; Riego-Perez, A.; Rout, P.; Rubbia, C.; Ryan, J.; Sabate-Gilarte, M.; Saxena, A.; Schillebeeckx, P.; Schmidt, S.; Sedyshev, P.; Smith, A. G.; Stamatopoulos, A.; Tagliente, G.; Tain, J. L.; Tarifeño-Saldivia, A.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Vlachoudis, V.; Vlastou, R.; Vollaire, J.; Wallner, A.; Warren, S.; Weigand, M.; Weiß, C.; Wolf, C.; Woods, P. J.; Wright, T.; Žugec, P.

    2016-01-01

    The energy-dependent cross section of the 7Be(n,alpha)4He reaction, of interest for the so-called Cosmological Lithium Problem in Big Bang Nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. The challenges posed by the short half-life of 7Be and by the low reaction cross section have been overcome at n_TOF thanks to an unprecedented combination of the extremely high luminosity and good resolution of the neutron beam in the new experimental area (EAR2) of the n_TOF facility at CERN, the availability of a sufficient amount of chemically pure 7Be, and a specifically designed experimental setup. Coincidences between the two alpha-particles have been recorded in two Si-7Be-Si arrays placed directly in the neutron beam. The present results are consistent, at thermal neutron energy, with the only previous measurement performed in the 60's at a nuclear reactor. The energy dependence here reported clearly indicates the inadequacy of the cross section estimates currently used in ...

  10. Diagnostic technique for measuring fusion reaction rate for inertial confinement fusion experiments at Shen Guang-III prototype laser facility

    International Nuclear Information System (INIS)

    Wang Feng; Peng Xiao-Shi; Liu Shen-Ye; Xu Tao; Kang Dong-Guo

    2013-01-01

    A study is conducted using a two-dimensional simulation program (Lared-s) with the goal of developing a technique to evaluate the effect of Rayleigh-Taylor growth in a neutron fusion reaction region. Two peaks of fusion reaction rate are simulated by using a two-dimensional simulation program (Lared-s) and confirmed by the experimental results. A neutron temporal diagnostic (NTD) system is developed with a high temporal resolution of ∼ 30 ps at the Shen Guang-III (SG-III) prototype laser facility in China, to measure the fusion reaction rate history. With the shape of neutron reaction rate curve and the spherical harmonic function in this paper, the degree of Rayleigh-Taylor growth and the main source of the neutron yield in our experiment can be estimated qualitatively. This technique, including the diagnostic system and the simulation program, may provide important information for obtaining a higher neutron yield in implosion experiments of inertial confinement fusion

  11. Use of molecular beams for kinetic measurements of chemical reactions on solid surfaces

    Science.gov (United States)

    Zaera, Francisco

    2017-05-01

    In this review we survey the contributions that molecular beam experiments have provided to our understanding of the dynamics and kinetics of chemical interactions of gas molecules with solid surfaces. First, we describe the experimental details of the different instrumental setups and approaches available for the study of these systems under the ultrahigh vacuum conditions and with the model planar surfaces often used in modern surface-science experiments. Next, a discussion is provided of the most important fundamental aspects of the dynamics of chemical adsorption that have been elucidated with the help of molecular beam experiments, which include the development of potential energy surfaces, the determination of the different channels for energy exchange between the incoming molecules and the surface, the identification of adsorption precursor states, the understanding of dissociative chemisorption, the determination of the contributions of corrugation, steps, and other structural details of the surface to the adsorption process, the effect to molecular steering, the identification of avenues for assisting adsorption, and the molecular details associated with the kinetics of the uptake of adsorbates as a function of coverage. We follow with a summary of the work directed at the determination of kinetic parameters and mechanistic details of surface reactions associated with catalysis, mostly those promoted by late transition metals. This discussion we initiate with an overview of what has been learned about simple bimolecular reactions such as the oxidation of CO and H2 with O2 and the reaction of CO with NO, and continue with the review of the studies of more complex systems such as the oxidation of alcohols, the conversion of organic acids, the hydrogenation and isomerization of olefins, and the oxidative activation of alkanes under conditions of short contact times. Sections 6 and 7 of this review deal with the advances made in the use of molecular beams with

  12. Exclusive measurements of Δ excitation by the (3He,t) reaction

    International Nuclear Information System (INIS)

    Hennino, Th.

    1993-12-01

    The production of Δ in nuclei through charge exchange reactions induced by medium energy light projectiles has been undertaken at Laboratoire National Saturne. The possible existence of a pionic collective mode built on Δ-hole correlations has been proposed to explain medium effects which appeared in inclusive experiments. Using the Diogene 4π apparatus to detect the charged particles, the decay pattern of the Δ-hole states has been separated into its different modes. 3 of them deserve particular attention: the quasi free Δ production, the two nucleon absorption channel and the coherent mode. (author). 17 refs., 10 figs

  13. Measurement of the tensor analyzing powers in the dd→3Hen and dd→3Hp reactions at RIKEN

    International Nuclear Information System (INIS)

    Ladygin, V.P.; Ladygina, N.B; Sakai, H.; Uesaka, T.

    2000-01-01

    A new experiment is proposed to measure the angular distribution of the tensor analyzing powers A yy , A xx , and A xz in the dd→ 3 Hen and dd→ 3 Hp reactions using polarized deuteron beam at RIKEN. These polarization observables are sensitive to the spin-momentum distribution of neutron (proton) in 3 He( 3 H) at short distances in the framework of one-nucleon exchange approximation. These measurements will provide new insight into the 3-nucleon system spin structure at distances unreachable at the moment using electromagnetic probes

  14. Measurement of nuclear reaction rates and spectral indices along the radius of fuel pellets from IPEN/MB-01 reactor

    International Nuclear Information System (INIS)

    Mura, Luis Felipe Liambos

    2010-01-01

    This work presents the measurements of the nuclear reaction rates along the radial direction of the fuel pellet by irradiation and posterior gamma spectrometry of a thin slice of fuel pellet of UO 2 with 4,3% enrichment. From its irradiation the rate of radioactive capture and fission have been measured as a function of the radius of the pellet disk using a HPGe detector. Lead collimators has been used for this purpose. Simulating the fuel pellet in the pin fuel of the IPEN/MB-01 reactor, a thin UO 2 disk is used. This disk is inserted in the interior of a dismountable fuel rod. This fuel rod is then placed in the central position of the IPEN/MB-01 reactor core and irradiated during 1 hour under a neutron flux of around 9 x 10 8 n/cm 2 s. For gamma spectrometry 10 collimators with different diameters have been used, consequently, the nuclear reactions of radioactive capture that occurs in atoms of 238 U and fissions that occur on both 235 U and 238 U are measured in function of 10 different region (diameter of collimator) of the fuel pellet disk. Corrections in the geometric efficiency due to introduction of collimators on HPGe detection system were estimated using photon transport of MCNP-4C code. Some calculated values of nuclear reaction rate of radioactive capture and fission along of the radial direction of the fuel pellet obtained by Monte Carlo methodology, using the MCNP-4C code, are presented and compared to the experimental data showing very good agreement. Besides nuclear reaction rates, the spectral indices 28 ρ and 25 δ have been obtained at each different radius of the fuel pellet disk. (author)

  15. Measurement of Visual Reaction Times Using Hand-held Mobile Devices

    Science.gov (United States)

    Mulligan, Jeffrey B.; Arsintescu, Lucia; Flynn-Evans, Erin

    2015-01-01

    Modern mobile devices provide a convenient platform for collecting research data in the field. But,because the working of these devices is often cloaked behind multiple layers of proprietary system software, it can bedifficult to assess the accuracy of the data they produce, particularly in the case of timing. We have been collecting datain a simple visual reaction time experiment, as part of a fatigue testing protocol known as the Psychomotor Vigilance Test (PVT). In this protocol, subjects run a 5-minute block consisting of a sequence of trials in which a visual stimulus appears after an unpredictable variable delay. The subject is required to tap the screen as soon as possible after the appearance of the stimulus. In order to validate the reaction times reported by our program, we had subjects perform the task while a high-speed video camera recorded both the display screen, and a side view of the finger (observed in a mirror). Simple image-processing methods were applied to determine the frames in which the stimulus appeared and disappeared, and in which the finger made and broke contact with the screen. The results demonstrate a systematic delay between the initial contact by the finger and the detection of the touch by the software, having a value of 80 +- 20 milliseconds.

  16. Measurement of alkali-silica reaction progression by ultrasonic waves attenuation

    International Nuclear Information System (INIS)

    Saint-Pierre, Francois; Rivard, Patrice; Ballivy, Gerard

    2007-01-01

    Development of non-destructive methods, developed specifically for assessing the damage induced by alkali-silica reaction (ASR) in concrete structures, is needed in order to carry out a systematic evaluation of the concrete condition. The aim of this study is to monitor the evolution of the ASR-damage in laboratory with concrete samples with ultrasonic pulse velocity and attenuation of ultrasonic waves methods. For this study, results of both methods were compared with expansion and mass variation. One reactive concrete mixture was made with reactive aggregate, and one other mixture, incorporating non-reactive aggregate, was made as a control. Specimens were kept at 38 deg. C in a 1 mol l -1 NaOH solution to accelerate the reaction. Attenuation of transmitted ultrasonic waves appeared to be more appropriate for the evaluation of ASR-damage compared with pulse velocity. The attenuation of accelerated reactive concrete cylinders increased by 90% after 1 year while it increased by 40% for the non-reactive concrete used as a control. Major part of the attenuation increase in the non-reactive concrete is due to liquid absorption. This work suggests that in-situ non-destructive techniques based on ultrasonic wave attenuation, like ultrasonic attenuation tomography, should be developed in order to evaluate the development of ASR in concrete structures. Petrographic examination confirmed that damage to concrete is associated with ASR

  17. Measurement of mass yields from the 241Am(2nth,f reaction at the Lohengrin Spectrometer

    Directory of Open Access Journals (Sweden)

    Köster U.

    2013-03-01

    Full Text Available The study of fission yields has a major impact on the characterization and understanding of the fission process and is mandatory for reactor applications. While the yields are known for the major actinides (235U, 239Pu in the thermal neutron-induced fission, only few measurements have been performed on 242Am. The interest of 242Am concerns the reduction of radiotoxicity of 241Am in nuclear wastes using transmutation reactions. This paper presents the measurement of the fission mass yields from the reaction 241Am(2nth,f performed at the Lohengrin mass spectrometer (ILL, France for both the light and the heavy peaks: a total of 41 mass yields have been measured. The experiment was also meant to determine whether there is a difference in mass yields between the isomeric state and the ground state as it exists in fission and capture cross sections. The method used to address this question is based on a repeated measurement of a set of fission mass yields as a function of the ratio between the 242gAm and the 242mAm fission rates. The presented experiment is also a first step towards the measurement of the isotopic fission yields of 242Am.

  18. First measurement of the polarization observable E in the p→(γ→,π+n reaction up to 2.25 GeV

    Directory of Open Access Journals (Sweden)

    S. Strauch

    2015-11-01

    Full Text Available First results from the longitudinally polarized frozen-spin target (FROST program are reported. The double-polarization observable E, for the reaction γ→p→→π+n, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been included in new multipole analyses resulting in updated nucleon resonance parameters. We report updated fits from the Bonn–Gatchina, Jülich–Bonn, and SAID groups.

  19. Measurement of activation cross-section of long-lived products in deuteron induced nuclear reactions on palladium in the 30-50MeV energy range.

    Science.gov (United States)

    Ditrói, F; Tárkányi, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2017-10-01

    Excitation functions were measured in the 31-49.2MeV energy range for the nat Pd(d,xn) 111,110m,106m,105,104g,103 Ag, nat Pd(d,x) 111m,109,101,100 Pd, nat Pd(d,x), 105,102m,102g,101m,101g,100,99m,99g Rh and nat Pd(d,x) 103,97 Ru nuclear reactions by using the stacked foil irradiation technique. The experimental results are compared with our previous results and with the theoretical predictions calculated with the ALICE-D, EMPIRE-D and TALYS (TENDL libraries) codes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Measurement of activation reaction rate distributions in a lead assembly bombarded with 500-MeV protons

    CERN Document Server

    Takada, H; Sasa, T; Tsujimoto, K; Yasuda, H

    2000-01-01

    Reaction rate distributions of various activation detectors such as the /sup nat/Ni(n, x)/sup 58/Co, /sup 197/Au(n,2n)/sup 196/Au, and /sup 197/Au(n,4n)/sup 194/Au reactions were measured to study the production and the transport of spallation neutrons in a lead assembly bombarded with protons of 500 MeV. The measured data were analyzed with the nucleon-meson transport code NMTC/JAERI combined with the MCNP4A code using the nuclide production cross sections based on the JENDL Dosimetry File and those calculated with the ALICE-F code. It was found that the NMTC/JAERI-MCNP4A calculations agreed well with the experiments for the low-energy-threshold reaction of /sup nat/Ni(n, x)/sup 58/Co. With the increase of threshold energy, however, the calculation underestimated the experiments, especially above 20 MeV. The reason for the disagreement can be attributed to the underestimation of the neutron yield in the tens of mega-electron-volt regions by the NMTC/JAERI code. (32 refs).

  1. Cross-reactivity of amino acids and other compounds in the biuret reaction: interference with urinary peptide measurements.

    Science.gov (United States)

    Hortin, Glen L; Meilinger, Bonnie

    2005-08-01

    Biuret assays for total protein measurement are considered to react with all peptides longer than 2 residues. Some studies using biuret assays of urine suggest that small peptides generally are more abundant than proteins in urine, but it is not clear whether this is a problem of assay specificity. We analyzed the specificity and kinetics of a biuret reaction for solutions of amino acids, organic compounds, peptides, proteins, and ultrafiltered urine specimens and compared the results with standard clinical assays for protein measurement. The biuret assay cross-reacted with several amino acids, dipeptides, and other organic compounds able to form 5- or 6-member ring chelation complexes with copper. Reactions with amino acids and dipeptides had higher absorbance maxima (blue color) than with larger peptides and proteins (purple). Compounds forming potential 4-, 7-, 8-, or 9-member ring complexes with copper had low reactivity. Amino acid amides, dipeptides, and longer peptides had substantial reactivity, except those containing proline. Proteins and polypeptides had similar biuret reactivities per peptide bond, but reaction kinetics were slower for proteins than peptides. Urine specimens ultrafiltered through 3-kDa-cutoff membranes had substantial biuret reactivity, but absorbance maxima were consistent with cross-reactive amino acids rather than peptides. Many compounds, including amino acids, amino acid derivatives, and dipeptides, cross-react in biuret assays. Our studies improve understanding of the specificity of endpoint and kinetic biuret assays widely used in clinical laboratories. Amino acids, urea, and creatinine contribute to overestimation of urinary peptide content by biuret assays.

  2. Investigation of fission properties and evaporation residue measurement in the reactions using 238U target nucleus

    Directory of Open Access Journals (Sweden)

    Saro S.

    2011-10-01

    Full Text Available Fragment mass distributions for fission after full momentum transfer were measured in the reactions of 30Si,34,36 S,31P,40Ar + 238U at bombarding energies around the Coulomb barrier. Mass distributions change significantly as a function of incident beam energy. The asymmetric fission probability increases at sub-barrier energy. The phenomenon is interpreted as an enhanced quasifission probability owing to orientation effects on fusion and/or quasifission. The evaporation residue (ER cross sections were measured in the reactions of 30Si + 238U and 34S + 238U to obtain information on fusion. In the latter reaction, significant suppression of fusion was implied. This suggests that fission events different from compound nucleus are included in the masssymmetric fragments. The results are supported by a model calculation based on a dynamical calculation using Langevin equation, in which the mass distribution for fusion-fission and quasifission fragments are separately determined.

  3. First simultaneous measurement of fission and gamma probabilities of 237U and 239Np via surrogate reactions

    Directory of Open Access Journals (Sweden)

    Marini P.

    2016-01-01

    Full Text Available Fission and gamma decay probabilities of 237U and 239Np have been measured, for the first time simultaneously in dedicated experiments, via the surrogate reactions 238U(3He, 4He and 238U(3He,d, respectively. While a good agreement between our data and neutron-induced data is found for fission probabilities, gamma decay probabilities are several times higher than the corresponding neutron-induced data for each studied nucleus. We study the role of the different spin distributions populated in the surrogate and neutron-induced reactions. The compound nucleus spin distribution populated in the surrogate reaction is extracted from the measured gamma-decay probabilities, and used as input parameter in the statistical model to predict fission probabilities to be compared to our data. A strong disagreement between our data and the prediction is obtained. Preliminary results from an additional dedicated experiment confirm the observed discrepancies, indicating the need of a better understanding of the formation and decay processes of the compound nucleus.

  4. In situ calibration of the Gamma Reaction History instrument using reference samples (“pucks” for areal density measurements

    Directory of Open Access Journals (Sweden)

    Hoffman N.M.

    2013-11-01

    Full Text Available The introduction of a sample of carbon, for example a disk or “puck”, near an imploding DT-filled capsule creates a source of 12C gamma rays that can serve as a reference for calibrating the response of the Gamma Reaction History (GRH detector [1]. Such calibration is important in the measurement of ablator areal density ⟨ρR⟩abl in plastic-ablator DT-filled capsules at OMEGA [2], by allowing ⟨ρR⟩abl to be inferred as a function of ratios of signals rather than from absolute measurements of signal magnitudes. Systematic uncertainties in signal measurements and detector responses therefore cancel, permitting more accurate measurements of ⟨ρR⟩abl.

  5. A New Proxy Measurement Algorithm with Application to the Estimation of Vertical Ground Reaction Forces Using Wearable Sensors

    Directory of Open Access Journals (Sweden)

    Yuzhu Guo

    2017-09-01

    Full Text Available Measurement of the ground reaction forces (GRF during walking is typically limited to laboratory settings, and only short observations using wearable pressure insoles have been reported so far. In this study, a new proxy measurement method is proposed to estimate the vertical component of the GRF (vGRF from wearable accelerometer signals. The accelerations are used as the proxy variable. An orthogonal forward regression algorithm (OFR is employed to identify the dynamic relationships between the proxy variables and the measured vGRF using pressure-sensing insoles. The obtained model, which represents the connection between the proxy variable and the vGRF, is then used to predict the latter. The results have been validated using pressure insoles data collected from nine healthy individuals under two outdoor walking tasks in non-laboratory settings. The results show that the vGRFs can be reconstructed with high accuracy (with an average prediction error of less than 5.0% using only one wearable sensor mounted at the waist (L5, fifth lumbar vertebra. Proxy measures with different sensor positions are also discussed. Results show that the waist acceleration-based proxy measurement is more stable with less inter-task and inter-subject variability than the proxy measures based on forehead level accelerations. The proposed proxy measure provides a promising low-cost method for monitoring ground reaction forces in real-life settings and introduces a novel generic approach for replacing the direct determination of difficult to measure variables in many applications.

  6. Spin-transfer measurements of the π rvec d→ rvec pp reaction at energies spanning the Δ resonance

    International Nuclear Information System (INIS)

    Feltham, A.; Jones, G.; Olszewski, R.; Pavan, M.; Sevior, M.; Trelle, R.P.; Weber, P.; Lolos, G.J.; Mathie, E.L.; Papandreou, Z.; Rui, R.; Gill, D.; Healey, D.; Ottewell, D.; Sheffer, G.; Smith, G.R.; Sossi, V.; Wait, G.; Walden, P.

    1997-01-01

    The first spin-transfer experiment performed for the π rvec d→ rvec pp reaction is described. Three spin-transfer parameters for this π-absorption process were determined, K LS a , K SS a , and K NN a , which correspond to the π-production parameters, K SL p , K SS p , and K NN p , of the time-reversed rvec pp→ rvec dπ process. Each observable was measured at a single angle for a number of energies spanning the Δ resonance of this system. The results are compared with the predictions of published partial wave amplitude fits which are primarily based on existing data for the time-reversed pp→dπ reaction, and also with the predictions of two current theories. The failure of these theories to describe the fundamental features of the data clearly demonstrates the need for further theoretical work in this area. copyright 1997 The American Physical Society

  7. Search for the Theta+ pentaquark in the gamma d -> Lambda n K+ reaction measured with CLAS

    Energy Technology Data Exchange (ETDEWEB)

    Silvia Niccolai; Marco Mirazita; Patrizia Rossi; Nathan Baltzell; Daniel Carman; Kenneth Hicks; Bryan McKinnon; Tsutomu Mibe; Stepan Stepanyan; David Tedeschi; Gary Adams; Pawel Ambrozewicz; Sergio Pereira; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; H. Bagdasaryan; Nathan Baillie; Jacques Ball; V. Batourine; Marco Battaglieri; Ivan Bedlinski; Ivan Bedlinskiy; Ivan Bedlinski; Ivan Bedlinskiy; Mehmet Bektasoglu; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Sergey Boyarinov; Sylvain Bouchigny; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; S.L. Careccia; Bryan Carnahan; Shifeng Chen; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; V. Crede; John Cummings; Natalya Dashyan; Pavel Degtiarenko; Rita De Masi; Airton Deppman; Enzo De Sanctis; Alexandre Deur; Raffaella De Vita; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; L. El Fassi; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Gerald Feldman; Herbert Funsten; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Lei Guo; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; John Hardie; F. Hersman; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Kenneth Livingston; H. Lu; Marion MacCormick; Nikolai Markov; Bernhard Mecking; Jonathan Mellor; Joseph Melone; Mac Mestayer; Curtis Meyer; Konstantin Mikhaylov; Ralph Minehart; Rory Miskimen; Viktor Mokeev; Ludyvine Morand; Steven Morrow; Maryam Moteabbed; Gordon Mutchler; Pawel Nadel-Turonski; James Napolitano; Rakhsha Nasseripour; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Jorge De Olivei Echeimberg; Mikhail Osipenko; Alexander Ostrovidov; K. Park; Evgueni Pasyuk; Craig Paterson; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; Sergey Pozdnyakov; Barry Preedom; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Franck Sabatie; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Aleksey Stavinskiy; Stepan Stepanyan; Burnham Stokes; Paul Stoler; Igor Strakovski; Steffen Strauch; Mauro Taiuti; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Daniel Watts; Lawrence Weinstein; Dennis Weygand; M. Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao; Zhiwen Zhao

    2006-04-26

    For the first time, the reaction gamma d -> Lambda n K+ has been analyzed in order to search for the exotic pentaquark baryon Theta+(1540). The data were taken at Jefferson Lab, using the Hall-B tagged-photon beam of energy between 0.8 and 3.6 GeV and the CEBAF Large Acceptance Spectrometer (CLAS). No statistically significant structures were observed in the nK+ invariant mass distribution. The upper limit on the gamma d -> Lambda Theta+ integrated cross section has been calculated and found to be between 5 and 25 nb, depending on the production model assumed. The upper limit on the differential cross section is also reported.

  8. Search for the Theta+ pentaquark in the gamma d -> Lambda n K+ reaction measured with CLAS

    International Nuclear Information System (INIS)

    Silvia Niccolai; Marco Mirazita; Patrizia Rossi; Nathan Baltzell; Daniel Carman; Kenneth Hicks; Bryan McKinnon; Tsutomu Mibe; Stepan Stepanyan; David Tedeschi; Gary Adams; Pawel Ambrozewicz; Sergio Pereira; Marco Anghinolfi; Gegham Asryan; Harutyun AVAKIAN; H. Bagdasaryan; Nathan Baillie; Jacques Ball; V. Batourine; Marco Battaglieri; Ivan Bedlinski; Ivan Bedlinskiy; Ivan Bedlinski; Ivan Bedlinskiy; Mehmet Bektasoglu; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Sergey Boyarinov; Sylvain Bouchigny; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; S.L. Careccia; Bryan Carnahan; Shifeng Chen; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; V. Crede; John Cummings; Natalya Dashyan; Pavel Degtiarenko; Rita De Masi; Airton Deppman; Enzo De Sanctis; Alexandre Deur; Raffaella De Vita; Kahanawita Dharmawardane; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; L. El Fassi; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Gerald Feldman; Herbert Funsten; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Lei Guo; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; John Hardie; F. Hersman; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; Kyungseon Joo; Henry Juengst; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Jeff Lachniet; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Kenneth Livingston; H. Lu; Marion MacCormick; Nikolai Markov; Bernhard Mecking

    2006-01-01

    For the first time, the reaction gamma d -> Lambda n K+ has been analyzed in order to search for the exotic pentaquark baryon Theta+(1540). The data were taken at Jefferson Lab, using the Hall-B tagged-photon beam of energy between 0.8 and 3.6 GeV and the CEBAF Large Acceptance Spectrometer (CLAS). No statistically significant structures were observed in the nK+ invariant mass distribution. The upper limit on the gamma d -> Lambda Theta+ integrated cross section has been calculated and found to be between 5 and 25 nb, depending on the production model assumed. The upper limit on the differential cross section is also reported

  9. Mach-Zehnder fiber-optic links for reaction history measurements at the National Ignition Facility

    International Nuclear Information System (INIS)

    Miller, E Kirk; Herrmann, H W; Stoeffl, W; Horsfield, C J

    2010-01-01

    We present the details of the analog fiber-optic data link that will be used in the chamber-mounted Gamma Reaction History (GRH) diagnostic at the National Ignition Facility (NIF) located at the Lawrence Livermore Laboratory in Livermore, California. The system is based on Mach-Zehnder (MZ) modulators integrated into the diagnostic, with the source lasers and bias control electronics located remotely to protect the active electronics. A complete recording system for a single GRH channel comprises two MZ modulators, with the fiber signals split onto four channels on a single digitizer. By carefully selecting the attenuation, the photoreceiver, and the digitizer settings, the dynamic range achievable is greater than 1000:1 at the full system bandwidth of greater than 10 GHz. The system is designed to minimize electrical reflections and mitigate the effects of transient radiation darkening on the fibers.

  10. Heavy ion reaction measurements with the EOS TPC (looking for central collisions with missing energy)

    International Nuclear Information System (INIS)

    Wieman, H.H.

    1994-05-01

    The EOS TPC was constructed for complete event measurement of heavy ion collisions at the Bevalac. We report here on the TPC design and some preliminary measurements of conserved event quantities such as total invariant mass, total momentum, total A and Z

  11. Determination of deuterium concentrations in JET plasmas from fusion reaction rate measurements

    International Nuclear Information System (INIS)

    Jarvis, O.N.; Balet, B.; Cordey, J.G.; Morgan, P.D.; Sadler, G.; Belle, P. van; Conroy, S.; Elevant, T.

    1989-01-01

    The concentration of deuterium in the central regions of JET plasmas, expressed as a fraction of the electron concentration (n d /n e ), has been determined using four different methods involving neutron detection. These measurements are found to be consistent and agree within experimental errors with values deduced from Z eff measurements using visible bremsstrahlung radiation. (author) 11 refs., 1 fig., 1 tab

  12. First measurement of 30S+α resonant elastic scattering for the 30S(α ,p ) reaction rate

    Science.gov (United States)

    Kahl, D.; Yamaguchi, H.; Kubono, S.; Chen, A. A.; Parikh, A.; Binh, D. N.; Chen, J.; Cherubini, S.; Duy, N. N.; Hashimoto, T.; Hayakawa, S.; Iwasa, N.; Jung, H. S.; Kato, S.; Kwon, Y. K.; Nishimura, S.; Ota, S.; Setoodehnia, K.; Teranishi, T.; Tokieda, H.; Yamada, T.; Yun, C. C.; Zhang, L. Y.

    2018-01-01

    Background: Type I x-ray bursts are the most frequently observed thermonuclear explosions in the galaxy, resulting from thermonuclear runaway on the surface of an accreting neutron star. The 30S(α ,p ) reaction plays a critical role in burst models, yet insufficient experimental information is available to calculate a reliable, precise rate for this reaction. Purpose: Our measurement was conducted to search for states in 34Ar and determine their quantum properties. In particular, natural-parity states with large α -decay partial widths should dominate the stellar reaction rate. Method: We performed the first measurement of 30S+α resonant elastic scattering up to a center-of-mass energy of 5.5 MeV using a radioactive ion beam. The experiment utilized a thick gaseous active target system and silicon detector array in inverse kinematics. Results: We obtained an excitation function for 30S(α ,α ) near 150∘ in the center-of-mass frame. The experimental data were analyzed with R -matrix calculations, and we observed three new resonant patterns between 11.1 and 12.1 MeV, extracting their properties of resonance energy, widths, spin, and parity. Conclusions: We calculated the resonant thermonuclear reaction rate of 30S(α ,p ) based on all available experimental data of 34Ar and found an upper limit about one order of magnitude larger than a rate determined using a statistical model. The astrophysical impact of these two rates has been investigated through one-zone postprocessing type I x-ray burst calculations. We find that our new upper limit for the 30S(α ,p )33Cl rate significantly affects the predicted nuclear energy generation rate during the burst.

  13. Measurement of fission yields from the 241Am(2nth,f reaction at the Lohengrin Spectrometer

    Directory of Open Access Journals (Sweden)

    Amouroux Ch.

    2013-12-01

    Full Text Available The study of fission yields has a major impact on the characterization and understanding of the fission process and is mandatory for reactor applications. While the yields are known for the major actinides (235U, 239Pu in the thermal neutron-induced fission, only few measurements have been performed on 242Am. This paper presents the results of a measurement at the Lohengrin mass spectrometer (ILL, France on the reaction 241Am(2nth,f: a total of 41 mass yields in the light and the heavy peaks have been measured and compared with the fission process simulation code GEF. Modus operandi and first results of a second experiment performed in May 2013 on the same reaction but with the goal of extracting the isotopic yields are presented as well: 8 mass yields were re-measured and 18 isotopic yields have been investigated and are being analyzed. Results concerning the kinetic energy and its comparison with the GEF Code are also presented in this paper.

  14. CH3CO + O2 + M (M = He, N2) Reaction Rate Coefficient Measurements and Implications for the OH Radical Product Yield.

    Science.gov (United States)

    Papadimitriou, Vassileios C; Karafas, Emmanuel S; Gierczak, Tomasz; Burkholder, James B

    2015-07-16

    The gas-phase CH3CO + O2 reaction is known to proceed via a chemical activation mechanism leading to the formation of OH and CH3C(O)OO radicals via bimolecular and termolecular reactive channels, respectively. In this work, rate coefficients, k, for the CH3CO + O2 reaction were measured over a range of temperature (241-373 K) and pressure (0.009-600 Torr) with He and N2 as the bath gas and used to characterize the bi- and ter-molecular reaction channels. Three independent experimental methods (pulsed laser photolysis-laser-induced fluorescence (PLP-LIF), pulsed laser photolysis-cavity ring-down spectroscopy (PLP-CRDS), and a very low-pressure reactor (VLPR)) were used to characterize k(T,M). PLP-LIF was the primary method used to measure k(T,M) in the high-pressure regime under pseudo-first-order conditions. CH3CO was produced by PLP, and LIF was used to monitor the OH radical bimolecular channel reaction product. CRDS, a complementary high-pressure method, measured k(295 K,M) over the pressure range 25-600 Torr (He) by monitoring the temporal CH3CO radical absorption following its production via PLP in the presence of excess O2. The VLPR technique was used in a relative rate mode to measure k(296 K,M) in the low-pressure regime (9-32 mTorr) with CH3CO + Cl2 used as the reference reaction. A kinetic mechanism analysis of the combined kinetic data set yielded a zero pressure limit rate coefficient, kint(T), of (6.4 ± 4) × 10(-14) exp((820 ± 150)/T) cm(3) molecule(-1) s(-1) (with kint(296 K) measured to be (9.94 ± 1.3) × 10(-13) cm(3) molecule(-1) s(-1)), k0(T) = (7.39 ± 0.3) × 10(-30) (T/300)(-2.2±0.3) cm(6) molecule(-2) s(-1), and k∞(T) = (4.88 ± 0.05) × 10(-12) (T/300)(-0.85±0.07) cm(3) molecule(-1) s(-1) with Fc = 0.8 and M = N2. A He/N2 collision efficiency ratio of 0.60 ± 0.05 was determined. The phenomenological kinetic results were used to define the pressure and temperature dependence of the OH radical yield in the CH3CO + O2 reaction. The

  15. Measurement of excitation functions in proton induced reactions on natural copper from their threshold to 43 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Shahid, Muhammad; Kim, Kwangsoo [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Naik, Haladhara [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Zaman, Muhammad [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Yang, Sung-Chul [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Kim, Guinyun, E-mail: gnkim@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of)

    2015-01-01

    We have measured the production cross-sections of the residual radionuclides from proton-induced reactions of {sup nat}Cu by using a stacked-foil activation and off-line γ-ray spectrometric technique in the energy range from their respective threshold to 43 MeV at the MC-50 cyclotron of the Korea Institute of Radiological and Medical Sciences. The measured results were compared with the earlier reported data as well as with the theoretical values obtained from the TENDL-2013 library based on the TALYS 1.6 code. The integral yields for thick target of the investigated radio-nuclides were calculated from the measured excitation function and the stopping power of {sup nat}Cu.

  16. Using Adobe Flash Lite on mobile phones for psychological research: Reaction time measurement reliability and interdevice variability.

    Science.gov (United States)

    Reimers, Stian; Stewart, Neil

    2008-11-01

    Mobile telephones have significant potential for use in psychological research, possessing unique characteristics-not least their ubiquity--that may make them useful tools for psychologists. We examined whether it is possible to measure reaction times (RTs) accurately using Adobe Flash Lite on mobile phones. We ran simple and choice RT experiments on two widely available mobile phones, a Nokia 6110 Navigator and a Sony Ericsson W810i, using a wireless application protocol (WAP) connection to access the Internet from the devices. RTs were compared within subjects with those obtained using a Linux-based millisecond-accurate measurement system. Results show that measured RTs were significantly longer on mobile devices, and that overall RTs and distribution of RTs varied across devices.

  17. Measurements of activation reaction rates in transverse shielding concrete exposed to the secondary particle field produced by intermediate energy heavy ions on an iron target

    International Nuclear Information System (INIS)

    Ogawa, T.; Morev, M.N.; Iimoto, T.; Kosako, T.

    2012-01-01

    Reaction rate distributions were measured inside a 60-cm thick concrete pile placed at the lateral position of a thick (stopping length) iron target that was bombarded with heavy ions, 400 MeV/u C and 800 MeV/u Si. Foils of aluminum and gold, as well as gold, tungsten and manganese covered with cadmium were inserted at various locations in the concrete pile to serve as activation detectors. Features of reaction rate distribution, such as the shape of the reaction rate profile, contribution of the neutrons from intra-nuclear cascade and that from evaporation to the activation reactions are determined by the analysis of measured reaction rates. The measured reaction rates were compared with those calculated with radiation transport simulation codes, FLUKA and PHITS, to verify their capability to predict induced activity. The simulated reaction rates agree with the experimental results within a factor of three in general. However, systematic discrepancies between simulated reaction rates and measured reaction rates attributed to the neutron source terms are observed.

  18. Transfer reaction measurements and the stellar nucleosynthesis of 26Al and 44Ti

    CERN Document Server

    AUTHOR|(CDS)2086831

    Progress in the description of stellar evolution is driven by the collaborative effort of nuclear physics, astrophysics and astronomy. Using those developments, the theory of the origin of elements in the Universe is challenged. This thesis addresses the problem behind the abundance of 44Ti and the origin of 26Al. The mismatch between the predicted abundance of 44Ti as produced by the only sites known to be able to create 44Ti, core collapse supernovae (CCSNe), and the observations, highlight the current uncertainty that exists in the physics of these stars. Several satellite based gamma-ray observations of the isotope 44Ti have been reported in recent times and conrm the disagreement. As the amount of this isotope in stellar ejecta is thought to critically depend on the explosion mechanism, the ability to accurately model the observed abundance would be a pivotal step towards validating that theory. The most in influential reaction to the amount of 44Ti in supernovae is 44Ti(alpha, p)47V. Here we report on a...

  19. Image-Based Measurement of H2O2 Reaction-Diffusion in Wounded Zebrafish Larvae.

    Science.gov (United States)

    Jelcic, Mark; Enyedi, Balázs; Xavier, João B; Niethammer, Philipp

    2017-05-09

    Epithelial injury induces rapid recruitment of antimicrobial leukocytes to the wound site. In zebrafish larvae, activation of the epithelial NADPH oxidase Duox at the wound margin is required early during this response. Before injury, leukocytes are near the vascular region, that is, ∼100-300 μm away from the injury site. How Duox establishes long-range signaling to leukocytes is unclear. We conceived that extracellular hydrogen peroxide (H 2 O 2 ) generated by Duox diffuses through the tissue to directly regulate chemotactic signaling in these cells. But before it can oxidize cellular proteins, H 2 O 2 must get past the antioxidant barriers that protect the cellular proteome. To test whether, or on which length scales this occurs during physiological wound signaling, we developed a computational method based on reaction-diffusion principles that infers H 2 O 2 degradation rates from intravital H 2 O 2 -biosensor imaging data. Our results indicate that at high tissue H 2 O 2 levels the peroxiredoxin-thioredoxin antioxidant chain becomes overwhelmed, and H 2 O 2 degradation stalls or ceases. Although the wound H 2 O 2 gradient reaches deep into the tissue, it likely overcomes antioxidant barriers only within ∼30 μm of the wound margin. Thus, Duox-mediated long-range signaling may require other spatial relay mechanisms besides extracellular H 2 O 2 diffusion. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  20. Measurement of gamma-ray emission from p-Li, p-Be, and d-Be reactions for accelerator-based BNCT

    International Nuclear Information System (INIS)

    Miyamaru, Hiroyuki; Murata, Isao; Ootera, Yasutaka; Kitamura, Akira

    2006-01-01

    Gamma-ray emission for each p-Li, p-Be, and d-Be nuclear reaction was investigated for accelerator-based BNCT. Measured gamma-ray energy spectra were analyzed and gamma-ray yield for a thick target was evaluated as a function of incident beam energy. Two intense gamma rays at 429 and 477 keV were observed in the p-Li reaction. The gamma ray at 477 keV was specified to be mainly due from the reaction of 7 Li(p,p') 7 Li * . In the p-Be reaction, a Doppler-broadened peak was observed at 3.56 MeV, resulting from the 9 Be(p,α) 6 Li * reaction. Four gamma peaks identified were from the transition of 10 B * generated by the d-Be reaction. Gamma-ray emission characteristics for each reaction are summarized. (author)

  1. Zirconium and Yttrium (p, d) Surrogate Nuclear Reactions: Measurement and determination of gamma-ray probabilities: Experimental Physics Report

    Energy Technology Data Exchange (ETDEWEB)

    Burke, J. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hughes, R. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Escher, J. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Scielzo, N. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Casperson, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ressler, J. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Saastamoinen, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ota, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Park, H. I. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ross, T. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McCleskey, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McCleskey, E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Austin, R. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Rapisarda, G. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-21

    This technical report documents the surrogate reaction method and experimental results used to determine the desired neutron induced cross sections of 87Y(n,g) and the known 90Zr(n,g) cross section. This experiment was performed at the STARLiTeR apparatus located at Texas A&M Cyclotron Institute using the K150 Cyclotron which produced a 28.56 MeV proton beam. The proton beam impinged on Y and Zr targets to produce the nuclear reactions 89Y(p,d)88Y and 92Zr(p,d)91Zr. Both particle singles data and particle-gamma ray coincident data were measured during the experiment. This data was used to determine the γ-ray probability as a function of energy for these reactions. The results for the γ-ray probabilities as a function of energy for both these nuclei are documented here. For completeness, extensive tabulated and graphical results are provided in the appendices.

  2. Magnetization-transfer measurements of individual rate constants in the presence of multiple reactions

    Science.gov (United States)

    Uǧurbil, Kâmil

    Magnetization-transfer techniques, such as saturation or inversion transfer, are extremely useful methods for measuring chemical-exchange rate constants which are comparable to spin-lattice relaxation rate constants of the exchanging spins. Although such determinations are relatively simple for a two-site exchange case, complications arise when multisite exchanges are involved. This severely restricts the applicability of this type of measurement, especially in whole cells and tissues where many reactants are utilized by more than one enzyme. In this paper, it is shown that a multisite exchange problem can first be reduced effectively to a two-site exchange, and a single rate constant can subsequently be measured simply and unequivocally. Application of this procedure to equilibrium and nonequilibrium chemical-exchange problems are discussed.

  3. A measurement of the cross section of the reaction $pp \\rightarrow n\\Delta^{++} (1232)$ at ISR energies

    CERN Document Server

    Kwak, N; Regler, Meinhard; Schmidt-Parzefall, W; Schubert, Klaus R; Winter, Klaus; Brandt, A; Dibon, Heinz; Flügge, G; Niebergall, F; Schumacher, P E; Aubert, Jean-Jacques; Broll, C; Coignet, G; Favier, Jean; Massonnet, Louis; Vivargent, M; Bartl, Walter; Eichinger, H; Gottfried, Christian; Neuhofer, Günther; Kwak, N; Nagy, E; Regler, M; Schmidt-Parzefall, W; Schubert, K R; Winter, K; Brandt, A no 2; Dibon, H no 2; Fluegge, G no 2; Niebergall, F no 2; Schumacher, P E no 2; Aubert, J J no 3; Broll, C no 3; Coignet, G no 3; Favier, J no 3; Massonnet, L no 3; Vivargent, M no 3; Bartl, W no 4; Eichinger, H no 4; Gottfried, C no 4; Neuhofer, G no 4

    1976-01-01

    A measurement of the cross section of the charge-exchange reaction pp to Delta /sup ++/(1232)n at square root s=23, 31 and 45 GeV at the CERN-ISR is reported. The energy dependences continues to follow a power law p/sub lab//sup -n/ with n=1.94+or-0.03 indicating dominance of one-pion exchange at the lowest ISR energy; there is some evidence for deviation from this at the higher ISR energies. (8 refs).

  4. Cross-section measurement for the reaction 115In(n,n')/sup 115m/In

    International Nuclear Information System (INIS)

    Liskien, H.; Arnotte, F.; Widera, R.; Paulsen, A.

    1978-01-01

    The excitation function for the reaction 115 In(n,n')/sup 115m/In was measured by the activation technique from threshold up to 4.1 MeV in 0.1-MeV steps. The absolute normalization of this excitation junction was performed at 2.1 MeV and is based on n-p scattering. The total uncertainty of the results is typically +- 6% above 1 MeV. The results are in good agreement with recently published data. 2 figures, 3 tables

  5. Measurement of the cross section of the 8Li(d,α)6He reaction of possible relevance to big bang nucleosynthesis

    International Nuclear Information System (INIS)

    Sahin, L.; Boyd, R.N.; Cole, A.L.; Famiano, M.; Gueray, R.T.; Murphy, A. St.J.; Oezkan, N.; Kolata, J.J.; Guimaraes, V.; Hencheck, M.

    2002-01-01

    We report measurements of the cross section of the 8 Li(d,α) 6 He reaction in the energy range E c.m. =2.3-3.5 MeV using a 8 Li-radioactive beam on a CD 2 foil. The astrophysical S factor and reaction rate were calculated from the measured cross section. The 6 He nuclei produced in the reaction were detected in solid-state detector telescopes. This reaction might have affected the primordial abundance of 6 Li in big bang nucleosynthesis, since 6 He beta decays to 6 Li. However, several big bang nucleosynthesis network calculations were found to be insensitive to this reaction, suggesting that the 8 Li(d,α) 6 He reaction does not affect 6 Li primordial production

  6. High resolution measurements and study of the neutron inelastic scattering reaction on 56Fe

    International Nuclear Information System (INIS)

    Dupont, E.

    1998-01-01

    High resolution measures of neutrons inelastic scattering cross section, have been performed on 56 Fe from 862 KeV to 3 MeV. The time of flight method has been used on the GELINA source of the IRMM in Geel (Belgium). Four barium fluoride scintillators, placed around the samples, recorded the gamma rays emissions coming from the iron and the boron. A study of the correlations between the partial elastic and inelastic lengths has been performed taking into account first transmission measures realized at Geel. (A.L.B.)

  7. Microspectrophotometric and electrophysiological measurements of the visual pigment reaction in Astacus

    Energy Technology Data Exchange (ETDEWEB)

    Gaube, H.; Gerhards-Doett, C.; Schlecht, P.; Stieve, H.; Wilms, M.

    1981-07-01

    Microspectrophotometric measurements of the spectral absorption of single rhabdoms of Astacus leptodactylus were carried out under various conditions of light adaptation and at different pH. The results were compared with electrophysiological measurements in Astacus leptodactylus and two other crayfish species (Astacus fluviatilis and Procambarus (ortmannicus) acutus), obtained with selective adaptation by colored light. A bistable visual pigment system was found in the microspectrophotometric measurements. The absorption spectra for rhodopsin (..gamma../sub max/ ca. 553 nm), and metarhodopsin (..gamma../sub max/ ca. 495 nm) were calculated, on the basis of Ebrey-Honig nomograms, from typical difference spectra. In the electrophysiological measurements the maximal spectral sensitivity was recorded at 565 nm. No indication for a basic metarhodopsin could be found in the pH range from 4.5 to 10.5. After 2% glutaraldehyde treatment the bleaching product of rhodopsin was no longer photoreversible, probably due to decomposition of metarhodopsin into retinal and opsin. Our results do not indicate two different types of photoreceptor pigments in Astacus as have been demonstrated by Wald (1968) for Orconectes and Procambarus.

  8. Numerical estimates of multiple reaction corrections in neutron cross-section measurements

    International Nuclear Information System (INIS)

    Magnusson, G.

    1979-04-01

    A method to evaluate the effect of secondary neutrons in 14-15 MeV neutron cross-section measurements is presented. The emission spectra of secondary neutrons are calculated by means of the preequilibrium and statistical models. An expression for the collision probability in a homogenous body has been utilized in the calculations. (author)

  9. Good agreement between minimal erythema dose test reactions and objective measurements

    DEFF Research Database (Denmark)

    Bodekær, Mette; Philipsen, Peter Alshede; Karlsmark, Tonny

    2013-01-01

    The erythema resulting from the minimal erythema dose (MED) test is subjectively assessed. The evaluator visually grades erythema on an ordinal scale. Both intra- and interobserver variation have been found for this erythema assessment. We wanted to examine if objective measurements could be used...

  10. Gamma-gamma angular correlation measurements in the 35Cl(n, γ)36Cl reaction

    NARCIS (Netherlands)

    Middelkoop, G. van; Spilling, P.

    1966-01-01

    With scintillation spectrometers, angular correlations have been measured of γ-radiation following thermal neutron capture in 35Cl. The following spins in 36Cl are determined: J(0.788) = 2 or 3, J(1.949) = 2, J(1.957) = 2, J(2.469) = 3. The latter three spin assignments are based on the assumption

  11. A colorimetric agarose gel for formaldehyde measurement based on nanotechnology involving Tollens reaction.

    Science.gov (United States)

    Zeng, Jing-bin; Fan, Shi-guang; Zhao, Cui-ying; Wang, Qian-ru; Zhou, Ting-yao; Chen, Xi; Yan, Zi-feng; Li, Yan-peng; Xing, Wei; Wang, Xu-dong

    2014-08-04

    Gold nanoparticles (Au NPs) coupled with Tollens reagent were used for measuring formaldehyde. Au@Ag core-shell NPs were formed along with distinct color changes from pink to deep yellow. This colorimetric system was further immobilized into an agarose gel, which was used for monitoring of gaseous formaldehyde.

  12. Experimental measurements of low temperature rate coefficients for neutral-neutral reactions of interest for atmospheric chemistry of Titan, Pluto and Triton: reactions of the CN radical.

    Science.gov (United States)

    Morales, Sébastien B; Le Picard, Sébastien D; Canosa, André; Sims, Ian R

    2010-01-01

    The kinetics of the reactions of cyano radical, CN (X2sigma+) with three hydrocarbons, propane (CH3CH2CH3), propene (CH3CH=CH2) and 1-butyne (CH[triple band]CCH2CH3) have been studied over the temperature range of 23-298 K using a CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme or Reaction Kinetics in Uniform Supersonic Flow) apparatus combined with the pulsed laser photolysis-laser induced fluorescence technique. These reactions are of interest for the cold atmospheres of Titan, Pluto and Triton, as they might participate in the formation of nitrogen and carbon bearing molecules, including nitriles, that are thought to play an important role in the formation of hazes and biological molecules. All three reactions are rapid with rate coefficients in excess of 10(-10) cm3 molecule(-1) s(-1) at the lowest temperatures of this study and show behaviour characteristic of barrierless reactions. Temperature dependences, different for each reaction, are compared to those used in the most recent photochemical models of Titan's atmosphere.

  13. Effect of the exothermal polymerization reaction on polymer gel dosimetric measurements

    International Nuclear Information System (INIS)

    Sedaghat, Mahbod; Bujold, Rachel; Lepage, Martin

    2010-01-01

    Discrepancies in polymer gel dosimetric measurements have been observed between containers of different sizes receiving the same radiation dose. We hypothesized that these deviations are caused by a change in the rate of polymerization due to internal heat increase in the gel containers resulting from the exothermic polymerization of monomers. Here, we test this hypothesis in a polyacrylamide gel dosimeter by recording the temperature in glass phantoms of different sizes during and after irradiation. The dose response of the samples was determined with magnetic resonance imaging. The difference of R 2 values along the depth of the containers was below ±1%. We discuss that this small difference can be attributed to variations in the rate of gelatin cooling during manufacture rather than to the measured heat increase during irradiation.

  14. The Hot Flush Behavior Scale: a measure of behavioral reactions to menopausal hot flushes and night sweats.

    Science.gov (United States)

    Hunter, Myra S; Ayers, Beverley; Smith, Melanie

    2011-11-01

    There is increasing interest in the development of nonmedical treatments for menopausal hot flushes (HF) and night sweats (NS) and some evidence that cognitive behavioral interventions reduce their impact. However, the behavioral component of HF/NS is underresearched. This article describes the development of the Hot Flush Behavior Scale (HFBehS), a measure of the behavioral strategies that women use in response to HF/NS, and reports on the reliability, validity, and factor structure of the scale. Behavioral items were generated from the empirical literature and qualitative studies based on in-depth interviews, with the aim of reflecting common behaviors related to HF/NS. A total of 140 women who had HF/NS completed the initial measure. Principal components analyses were applied to the data, with orthogonal rotation, to determine the most coherent and interpretable solution. Exploratory factor analysis culminated in an 11-item measure comprising three dimensions: behavioral avoidance, practical cooling behaviors, and positive behavioral strategies. The Hot Flush Beliefs Scale subscales had reasonable internal consistency, with α values ranging from 0.59 to 0.76. Validity was supported through correlations with measures of HF/NS problem rating and frequency and cognitive measures (HF/NS beliefs). Preliminary analysis of the HFBehS reveals it to be a psychometrically sound instrument. The HFBehS is grounded in women's experiences and can be used as a measure of behavioral reactions to HF/NS as well as enabling more rigorous evaluation of psychological interventions.

  15. Measurement of high energy neutrons via Lu(n,xn) reactions

    International Nuclear Information System (INIS)

    Henry, E.A.; Becker, J.A.; Archer, D.E.; Younes, W.; Stoyer, M.A.; Slaughter, D.

    1997-07-01

    High energy neutrons can be assayed by the use of the nuclear diagnostic material lutetium. We are measuring the (n,xn) cross sections for natural lutetium in order to develop it as a detector material. We are applying lutetium to diagnose the high energy neutrons produced in test target/blanket systems appropriate for the Accelerator Production of Tritium Project. 3 refs., 5 figs., 1 tab

  16. Measurement of cross-sections for the (p, xn) reactions in natural molybdenum

    International Nuclear Information System (INIS)

    Khandaker, M.U.; Uddin, M.S.; Kim, K.S.; Lee, Y.S.; Kim, G.N.

    2007-01-01

    Cross-sections for the residual radionuclide productions by proton-induced activation on natural molybdenum were measured up to 40 MeV by using a stacked-foil technique at the MC50 cyclotron of the Korea Institute of Radiological and Medical Sciences (KIRAMS). This work has given a new data set for the formation of the investigated radionuclides. The present results for most of the radionuclides showed in general good agreement with the earlier reported data as well as the theoretical data taken from the calculations based on the ALICE-IPPE code. The integral yields for thick targets were also deduced from the measured cross-sections of the produced radionuclides. The optimum production of the 99m Tc radionuclide with minimum impurities can be obtained at the energy ranges from 10 to 23 MeV, where the production yields were obtained as 597.15 MBqμA -1 h -1 at saturation. The measured cross-sections are used for production of medically important radionuclides such as 99m Tc, 94m Tc and 93m,g Tc by using the medium-energy cyclotrons

  17. A Phoswich Detector System to Measure Sub-Second Half-Lives using ICF Reactions

    Science.gov (United States)

    Coats, Micah; Cook, Katelyn; Yuly, Mark; Padalino, Stephen; Sangster, Craig; Regan, Sean

    2017-10-01

    The 3H(t,γ)6He cross section has not been measured at any bombarding energy due to the difficulties of simultaneously producing both a tritium beam and target at accelerator labs. An alternative technique may be to use an ICF tt implosion at the OMEGA Laser Facility. The 3H(t,γ)6He cross section could be determined in situ by measuring the beta decay of 6He beginning a few milliseconds after the shot along with other ICF diagnostics. A dE-E phoswich system capable of surviving in the OMEGA target chamber was tested using the SUNY Geneseo pelletron to create neutrons via 2H(d,n)3He and subsequently 6He via 9Be(n,α)6He in a beryllium target. The phoswich dE-E detector system was used to select beta decay events and measure the 807 ms half-life of 6He. It is composed of a thin, 2 ns decay time dE scintillator optically coupled to a thick, 285 ns E scintillator, with a linear gate to separate the short dE pulse from the longer E tail. Funded in part by a Grant from the DOE through the Laboratory for Laser Energetics.

  18. Contribution of cell culture, RNA extraction, and reverse transcription to the measurement error in quantitative reverse transcription polymerase chain reaction-based gene expression quantification.

    Science.gov (United States)

    Combes, Jean-Damien; Grelier, Gaël; Laversanne, Matthieu; Voirin, Nicolas; Chabaud, Sylvie; Ecochard, René; Lasset, Christine; Moyret-Lalle, Caroline

    2009-10-01

    Quantitative polymerase chain reaction (qPCR) instruments are known to be reliable. However, many authors have underlined the poor reliability of the procedures that precede the measurement of gene expression--cell culture, RNA extraction, and reverse transcription. Here we quantified the measurement errors due to each step and estimated the correction that would accrue from replicating any of those steps. We measured the relative expression of the APC-11 gene (the catalytic anaphase-promoting complex/cyclosome subunit suspected to be involved in breast cancer) with step replication in 18 breast cancer cell lines. The final qPCR step was found to be reproducible (standard deviation [SD]=0.26). In comparison with the between-cell-line variability (SD=1.7), the variability due to the previous steps (cell culture, RNA extraction, and reverse transcription) was on the same order of magnitude (SD=1.2-2.0). Misclassification rates were used to assess the impact of replicating each manual procedure. The misclassification rates improved with replication of cell culture, RNA extraction, and reverse transcription (90.0, 60.9, and 61.1% decreases, respectively). The results point out a high error level in the quantification of gene expression, and these errors may stem from all steps of the procedure. The best correction would accrue from replicating cell culture.

  19. Measurement of Excitation Spectra in the ^{12}C(p,d) Reaction near the η^{'} Emission Threshold.

    Science.gov (United States)

    Tanaka, Y K; Itahashi, K; Fujioka, H; Ayyad, Y; Benlliure, J; Brinkmann, K-T; Friedrich, S; Geissel, H; Gellanki, J; Guo, C; Gutz, E; Haettner, E; Harakeh, M N; Hayano, R S; Higashi, Y; Hirenzaki, S; Hornung, C; Igarashi, Y; Ikeno, N; Iwasaki, M; Jido, D; Kalantar-Nayestanaki, N; Kanungo, R; Knöbel, R; Kurz, N; Metag, V; Mukha, I; Nagae, T; Nagahiro, H; Nanova, M; Nishi, T; Ong, H J; Pietri, S; Prochazka, A; Rappold, C; Reiter, M P; Rodríguez-Sánchez, J L; Scheidenberger, C; Simon, H; Sitar, B; Strmen, P; Sun, B; Suzuki, K; Szarka, I; Takechi, M; Tanihata, I; Terashima, S; Watanabe, Y N; Weick, H; Widmann, E; Winfield, J S; Xu, X; Yamakami, H; Zhao, J

    2016-11-11

    Excitation spectra of ^{11}C are measured in the ^{12}C(p,d) reaction near the η^{'} emission threshold. A proton beam extracted from the synchrotron SIS-18 at GSI with an incident energy of 2.5 GeV impinges on a carbon target. The momenta of deuterons emitted at 0° are precisely measured with the fragment separator (FRS) operated as a spectrometer. In contrast to theoretical predictions on the possible existence of deeply bound η^{'}-mesic states in carbon nuclei, no distinct structures are observed associated with the formation of bound states. The spectra are analyzed to set stringent constraints on the formation cross section and on the hitherto barely known η^{'}-nucleus interaction.

  20. Heavy ions reactions at GANIL energies: the use of LISE telescopic mode for the small angle measurements

    International Nuclear Information System (INIS)

    Bacri, C.O.

    1989-01-01

    The use of heavy ions at GANIL energies leads to a concentration of the reaction products in the forward direction. Measurements have to be performed at and around 0 degree and with an accuracy around one milliradian. The angular selection (after the two dipoles) is performed after a magnetic rigidity one (between the two dipoles). The double sorting does allow measurements close to the beam in magnetic rigidity and in angle. TRANSPORT calculations show that the LISE spectrometer of GANIL can be used in telescopic mode. Experiments with a 44 MeV per nucleon Argon beam on C, Al, Ni and Au targets are performed. The identification of all the detected ions allowed the obtention of angular distributions at and around 0 degree with the required accuracy. This study is completed by a theoretical approach of the thermodynamical evolution based on an extended quantal mean field theory in which a collision-like term simulates residual interaction effects [fr

  1. Fission fragment angular distribution measurements for 16O + 194Pt reaction at energies near the Coulomb barrier

    Science.gov (United States)

    Prasad, E.; Varier, K. M.; Thomas, R. G.; Vinodkumar, A. M.; Mahata, K.; Appannababu, S.; Sugathan, P.; Golda, K. S.; Babu, B. R. S.; Saxena, A.; John, B. V.; Kailas, S.

    2012-05-01

    Fission fragment angular distributions have been measured for 16O + 194Pt reaction forming the compound system 210Rn, in the laboratory energy range from 79 to 90 MeV. The measured fission fragment anisotropies as a function of E/VB are compared with the predictions of standard saddle point statistical model (SSPM). Anisotropies calculated using the average excitation energy and angular momentum values could not reasonably fit the experimental data. Statistical model calculations were performed using the PACE with modified fission barrier and level density parameters. Fission probability, evaporation residue cross section and neutron multiplicity were simultaneously used to fix the statistical parameters. Model calculations incorporating the chance nature of fission decay and scaled values of the rotating finite range model (RFRM) moment of inertia could reasonably fit the fragment angular anisotropies.

  2. Measurements and Evaluation of Nuclear Reaction Cross Sections Leading to Various Practical Applications in Science and Technology

    Energy Technology Data Exchange (ETDEWEB)

    Khandaker, Mayeen Uddin; Lee, Young Ouk; Cho, Young Sik

    2008-07-15

    This report contains the measurements and evaluation of production cross sections of some medically and technologically important radionuclides over the energy range 1-40 MeV by using a conventional stacked-foil activation technique combined with high purity germanium (HPGe) -ray spectrometry. The irradiations were done by using the external beam line of the MC-50 cyclotron at the Korea Institute of Radiological and Medical Sciences (KIRAMS). The standard cross sections for monitor reactions were taken from IAEA web site. Integral yields for the investigated radionuclides were deduced using the measured cross-sections. Reported data were compared with the available literature data, theoretical calculations by the codes TALYS and ALICE-IPPE, and a good overall agreement among them was found.

  3. Measurement of the proton total reaction cross section for 159Tb, 181Ta and 197Au between 20 and 48 MeV

    International Nuclear Information System (INIS)

    Abegg, R.; Birchall, J.; Davison, N.E.; Jong, M.S. de; Ginther, D.L.; Hasell, D.K.; Nasr, T.N.; Oers, W.T.H. van; Carlson, R.F.; Cox, A.J.

    1979-01-01

    Proton total reaction cross sections have been measured for the nuclei 159 Tb, 181 Ta and 197 Au at seven proton energies between 20 and 48 MeV using an attenuation technique. The experimentally determined energy dependence of the total reaction cross sections is compared with results obtained for black nucleus and optical model calulations. (Auth.)

  4. Measurement of the 3He(e,e'p)pn reaction at high missing energies and momenta

    Energy Technology Data Exchange (ETDEWEB)

    F. Benmokhtar; M. M. Rvachev; E. Penel-Nottaris

    2004-09-01

    Results of the Jefferson Lab Hall A quasielastic 3He(e,e'p)pn measurements are presented. These measurements were performed at fixed transferred momentum and energy, q = 1502 MeV/c and omega = 840 MeV, respectively, for missing momenta {+-} up to 1 GeV/c and missing energies in the continuum region, up to pion threshold; this kinematic coverage is much more extensive than that of any previous experiment. The cross section data are presented along with the effective momentum density distribution and compared to theoretical models.

  5. Large Acceptance Measurement of Photons and Charged Particles in Heavy Ion Reactions

    CERN Multimedia

    2002-01-01

    % WA98 \\\\ \\\\ The aim of the experiment is the high statistics study of photons and neutral hadrons, as well as of charged particles, and their correlations in Pb~-~Pb collisions. The photons are measured by: \\begin{enumerate}[-] \\item a 10~000 module LEADGLASS SPECTROMETER yielding high precision data on $ \\pi ^0 $ and $ \\eta $ at midrapidity (with transverse momenta 0.3 GeV/c $>$ p$ _{T} $ $>$ 4.5 GeV/c for $\\pi ^0 $ and 1.5~GeV/c~$>$~p$ _{T}~$ $>$~4.0~GeV/c for $ \\eta $ covering the $^{\\prime\\prime}$thermal$^{\\prime\\prime}$ as well as the $^{\\prime\\prime}$hard scattering$^{\\prime\\prime}$ regime beyond 3~GeV/c) and determination of the thermal and direct photon to $ \\pi ^0 $ ratio. \\item a pad preshower PHOTON MULTIPLICITY DETECTOR which, by comparing with the charged particle multiplicity measurement allows to determine the photon enrichment in an event or event class. \\end{enumerate}\\\\ \\\\The charged particle setup contains:\\\\ \\\\\\begin{enumerate}[-] \\item a 4000 element SILICON PAD DETECTOR and a 4-inch SIL...

  6. Integrating Item Accuracy and Reaction Time to Improve the Measurement of Inhibitory Control Abilities in Early Childhood.

    Science.gov (United States)

    Magnus, Brooke E; Willoughby, Michael T; Blair, Clancy B; Kuhn, Laura J

    2017-11-01

    Efforts to improve children's executive function are often hampered by the lack of measures that are optimized for use during the transition from preschool to elementary school. Whereas preschool-based measures often emphasize response accuracy, elementary school-based measures emphasize reaction time (RT)-especially for measures inhibitory control (IC) tasks that typically have a speeded component. The primary objective of this study was to test in a preschool-aged sample whether the joint use of item-level accuracy and RT data resulted in improved scoring for three IC tasks relative to scores derived from accuracy data alone. Generally, the joint use of item-level accuracy and RT data resulted in modest improvements in the measurement precision of IC abilities. Moreover, the joint use of item-level accuracy and RT helped eliminate floor and ceiling effects that occurred when accuracy data were considered alone. Results are discussed with respect to the importance of scoring IC tasks in ways that are maximally informative for program evaluation and longitudinal modeling.

  7. The Gas-Absorption/Chemical-Reaction Method for Measuring Air-Water Interfacial Area in Natural Porous Media

    Science.gov (United States)

    Lyu, Ying; Brusseau, Mark L.; El Ouni, Asma; Araujo, Juliana B.; Su, Xiaosi

    2017-11-01

    The gas-absorption/chemical-reaction (GACR) method used in chemical engineering to quantify gas-liquid interfacial area in reactor systems is adapted for the first time to measure the effective air-water interfacial area of natural porous media. Experiments were conducted with the GACR method, and two standard methods (X-ray microtomographic imaging and interfacial partitioning tracer tests) for comparison, using model glass beads and a natural sand. The results of a series of experiments conducted under identical conditions demonstrated that the GACR method exhibited excellent repeatability for measurement of interfacial area (Aia). Coefficients of variation for Aia were 3.5% for the glass beads and 11% for the sand. Extrapolated maximum interfacial areas (Am) obtained with the GACR method were statistically identical to independent measures of the specific solid surface areas of the media. For example, the Am for the glass beads is 29 (±1) cm-1, compared to 32 (±3), 30 (±2), and 31 (±2) cm-1 determined from geometric calculation, N2/BET measurement, and microtomographic measurement, respectively. This indicates that the method produced accurate measures of interfacial area. Interfacial areas determined with the GACR method were similar to those obtained with the standard methods. For example, Aias of 47 and 44 cm-1 were measured with the GACR and XMT methods, respectively, for the sand at a water saturation of 0.57. The results of the study indicate that the GACR method is a viable alternative for measuring air-water interfacial areas. The method is relatively quick, inexpensive, and requires no specialized instrumentation compared to the standard methods.

  8. Optical fiber sensor technique for strain measurement during materials deposition, chemical reaction, and relaxation

    Science.gov (United States)

    Butler, M.A.; Ginley, D.S.

    1988-01-21

    Laser light from a common source is split and conveyed through two similar optical fibers and emitted at their respective ends to form an interference pattern, one of the optical fibers having a portion thereof subjected to a strain. Changes in the strain cause changes in the optical path length of the strain fiber, and generate corresponding changes in the interference pattern. The interference pattern is received and transduced into signals representative of fringe shifts corresponding to changes in the strain experienced by the strained one of the optical fibers. These signals are then processed to evaluate strain as a function of time, typical examples of the application of the apparatus including electrodeposition of a metallic film on a conductive surface provided on the outside of the optical fiber being strained, so that strains generated in the optical fiber during the course of the electrodeposition are measurable as a function of time. In one aspect of the invention, signals relating to the fringe shift are stored for subsequent processing and analysis, whereas in another aspect of the invention the signals are processed for real-time display of the strain changes under study. 9 figs.

  9. Recovery of Odorants from an Olfactometer Measured by Proton-Transfer-Reaction Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Anders Feilberg

    2013-06-01

    Full Text Available The aim of the present study was to examine the recovery of odorants during the dilution in an olfactometer designed according to the European standard for dynamic olfactometry. Nine odorants in the ppmv-range were examined including hydrogen sulfide, methanethiol, dimethyl sulfide, acetic acid, propanoic acid, butanoic acid, trimethylamine, 3-methylphenol and n-butanol. Each odorant was diluted in six dilution steps in descending order from 4,096 to 128 times dilutions. The final recovery of dimethyl sulfide and n-butanol after a 60-second pulse was only slightly affected by the dilution, whereas the recoveries of the other odorants were significantly affected by the dilution. The final recoveries of carboxylic acids, trimethylamine and 3-methylphenol were affected by the pulse duration and the signals did not reach stable levels within the 60-second pulse, while sulfur compounds and n-butanol reach a stable signal within a few seconds. In conclusion, the dilution of odorants in an olfactometer has a high impact on the recovery of odorants and when olfactometry is used to estimate the odor concentration, the recoveries have to be taken into consideration for correct measurements.

  10. Mass-transport limitation to in-cloud reaction rates: Implications of new accommodation coefficient measurements

    International Nuclear Information System (INIS)

    Schwartz, S.E.

    1988-10-01

    Although it has been recognized for some time that the rate of reactive uptake of gases in cloudwater can depend on the value of the mass-accommodation coefficient (α) describing interfacial mass transport (MT), definitive evaluation of such rates is only now becoming possible with the availability of measurements of α for gases of atmospheric interest at air-water interfaces. Examination of MT limitation to the rate of in-cloud aqueous-phase oxidation of SO 2 by O 3 and H 2 O 2 shows that despite the low value of α/sub O3/ (5 /times/ 10/sup /minus/4/), interfacial MT of this species is not limiting under essentially all conditions of interest; the high values of α for SO 2 (≥ 0.2) and H 2 O 2 (≥ 0.08) indicate no interfacial MT limitation for these species also. Although gas- and aqueous-phase MT can be limiting under certain extremes of conditions, treating the system as under chemical kinetic control is generally an excellent approximation. Interfacial MT limitation also is found not to hinder the rate of H 2 O 2 formation by aqueous-phase disproportionation of HO 2 . Finally, the rapid uptake of N 2 O 5 by cloud droplets implies that the yield of aqueous HNO 3 from in-cloud gas-phase oxidation of NO 2 by O 3 can be substantial even under daytime conditions. This report consists of copies of viewgraphs prepared for this presentation

  11. Parallel reaction monitoring on a Q Exactive mass spectrometer increases reproducibility of phosphopeptide detection in bacterial phosphoproteomics measurements.

    Science.gov (United States)

    Taumer, Christoph; Griesbaum, Lena; Kovacevic, Alen; Soufi, Boumediene; Nalpas, Nicolas C; Macek, Boris

    2018-03-29

    Increasing number of studies report the relevance of protein Ser/Thr/Tyr phosphorylation in bacterial physiology, yet the analysis of this type of modification in bacteria still presents a considerable challenge. Unlike in eukaryotes, where tens of thousands of phosphorylation events likely occupy more than two thirds of the proteome, the abundance of protein phosphorylation is much lower in bacteria. Even the state-of-the-art phosphopeptide enrichment protocols fail to remove the high background of abundant unmodified peptides, leading to low signal intensity and undersampling of phosphopeptide precursor ions in consecutive data-dependent MS runs. Consequently, large-scale bacterial phosphoproteomic datasets often suffer from poor reproducibility and a high number of missing values. Here we explore the application of parallel reaction monitoring (PRM) on a Q Exactive mass spectrometer in bacterial phosphoproteome analysis, focusing especially on run-to-run sampling reproducibility. In multiple measurements of identical phosphopeptide-enriched samples, we show that PRM outperforms data-dependent acquisition (DDA) in terms of detection frequency, reaching almost complete sampling efficiency, compared to 20% in DDA. We observe a similar trend over multiple heterogeneous phosphopeptide-enriched samples and conclude that PRM shows a great promise in bacterial phosphoproteomics analyses where reproducible detection and quantification of a relatively small set of phosphopeptides is desired. Bacterial phosphorylated peptides occur in low abundance compared to their unmodified counterparts, and are therefore rarely reproducibly detected in shotgun (DDA) proteomics measurements. Here we show that parallel reaction monitoring complements DDA analyses and makes detection of known, targeted phosphopeptides more reproducible. This will be of significance in replicated MS measurements that have a goal to reproducibly detect and quantify phosphopeptides of interest. Copyright

  12. Ultra-sensitive HPLC-photochemical reaction-luminol chemiluminescence method for the measurement of secondary amines after nitrosation.

    Science.gov (United States)

    Kodamatani, Hitoshi; Iwaya, Yoshimi; Saga, Makoto; Saito, Keiitsu; Fujioka, Takahiro; Yamazaki, Shigeo; Kanzaki, Ryo; Tomiyasu, Takashi

    2017-02-01

    A novel method for the determination of secondary amines at the nanomolar level was developed. The method is based on the nitrosation reaction of secondary amines, with the generated N-nitrosamines being measured using an HPLC separation, photochemical reaction, and chemiluminescence detection system. The efficient nitrosation of secondary amines was performed using sodium nitrite (200 mM) and acetic acid (0.8 M) at 80 °C over 60 min. Although compounds bearing OH and SH functional groups also underwent the nitrosation reaction, the sensitivity of these compounds was 1000 times lower than that of the secondary amines. Our method was applied to the determination of low molecular weight secondary amines, including dimethylamine, morpholine, pyrrolidine, diethylamine, and piperidine, giving method detection limits of 0.7 nM, 0.2 nM, 0.4 nM, 0.7 nM, and 1.5 nM, respectively. The calibration curves were linear in the range of 5-100 nM. We then applied this method for the detection and quantification of these secondary amines in samples of tap water, river water, treated wastewater, and sea water. Dimethylamine was detected at concentrations up to 15.4 nM, <0.7 nM, and 48.5 nM in tap water, river water, and treated wastewater samples, respectively, with recoveries ranging from 94 to 103%. Other amines were also detected at nanomolar levels. These results indicate that our proposed method can be applied to the analysis of secondary amines in various environmental water samples. To the best of our knowledge, the proposed method is one of the most sensitive and selective methods for the determination of secondary amines without pre-concentration steps. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. New High-Precision Measurement of the Reaction Rate of the O-18(p, alpha)N-15 Reaction via THM

    Czech Academy of Sciences Publication Activity Database

    La Cognata, M.; Spitaleri, C.; Mukhamedzhanov, A. M.; Irgaziev, B.; Tribble, R. E.; Banu, A.; Cherubini, S.; Coc, A.; Crucilla, V.; Goldberg, V. Z.; Gulino, M.; Kiss, G. G.; Lamia, L.; Chengbo, L.; Mrázek, Jaromír; Pizzone, R. G.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Tabacaru, G.; Trache, L.; Trzaska, W.; Tumino, A.

    2009-01-01

    Roč. 26, č. 3 (2009), s. 237-242 ISSN 1323-3580 Institutional research plan: CEZ:AV0Z10480505 Keywords : nuclear reactions * nucleosynthesis * abundances Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 3.786, year: 2009

  14. First results of total and partial cross-section measurements of the 107Ag(p,γ)108Cd reaction

    Science.gov (United States)

    Heim, Felix; Mayer, Jan; Scholz, Philipp; Spieker, Mark; Zilges, Andreas

    2018-01-01

    The γ process is assumed to play an important role in the nucleosynthesis of the majority of the p nuclei. Since the network of the γ process includes so many different reactions and - mainly unstable - nuclei, cross-section values are predominantly calculated in the scope of the Hauser-Feshbach statistical model. The values heavily depend on the nuclear-physics input parameters. The results of total and partial cross-section measurements are used to improve the accuracy of the theoretical calculations. In order to extend the experimental database, the 107Ag(p,γ)108Cd reaction was studied via the in-beam method at the high-efficiency HPGe γ-ray spectrometer HORUS at the University of Cologne. Proton beams with energies between 3.5 MeV and 5.0 MeV were provided by the 10 MV FN-Tandem accelerator leading to the determination of four new total cross-section values. After slight adjustments of the nuclear level density and γ-ray strength function an excellent agreement between theoretical calculations and experimentally deduced values for both total and partial cross sections has been obtained.

  15. Partial gamma-ray cross section measurements in 109Ag(n, x n y p gamma) reactions

    Energy Technology Data Exchange (ETDEWEB)

    Fotiadis, Nikolaos [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Devlin, Matthew James [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Nelson, Ronald Owen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carroll, James [US Army Research Laboratory, Adelphi, MD (United States)

    2015-06-02

    We report on absolute partial cross sections for production of discrete γ-rays using 109Ag(n, xnypγ) reactions with x ≤ 7 and y ≤ 1 in a total of 12 reaction channels. The data were taken using the GEANIE spectrometer comprised of 20 high-purity Ge detectors with 20 BGO escape-suppression shields. The broad-spectrum pulsed neutron beam of the Los Alamos Neutron Science Center’s (LANSCE) WNR facility provided neutrons in the energy range from 0.2 to 300 MeV. The time-of- flight technique was used to determine the incident neutron energies. Partial γ-ray cross sections have been measured for a total of 109 transitions and for neutron energies 0.8 MeV< En<300 MeV. An estimate of the population of isomers in the (n, n'), (n, 2n) and (n, 3n) channels was made.

  16. On possibility of measuring G and H parameters in the γp→nπ+ and γp → pπ0 reactions

    International Nuclear Information System (INIS)

    Gorbenko, V.G.; Gushchin, V.A.; Karnaukhov, I.M.; Kolesnikov, L.Ya.; Sporov, E.A.; Telegin, Yu.N.; Sorokin, P.V.

    1982-01-01

    Possibilities for measuring G and H-parameters in γp → nπ + and γp → pπ 0 reactions in a twice-polarized experiment using linearly-polarized photons and polarized proton target with proton polarization in the reaction plane are considered. Particle trajectories in the magnetic field of the polarized proton target are calculated, limitations in possible experiments are shown which are connected with particle deviation from the plane of magnetic spectrometers. On the basis of calculations of the trajectory the ranges for possible measurements of parameters for different reactions for the routine regime of target operation and the frosen spin regime are shown

  17. Remarks concerning the accurate measurement of differential cross sections for threshold reactions used in fast-neutron dosimetry for fission reactors

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.L.

    1976-12-01

    Some remarks are submitted concerning the measurement of differential cross sections for threshold reactions which are used in fast-neutron dosimetry for fission reactors. The objective is to familiarize the reader with some of the problems associated with these measurements and, in the process, to explain why the existence of large discrepancies in the data sets for many of these reactions is not surprising. Limits to the accuracy which can be expected for these cross sections in the near future--using current technology and available resources--are examined in a general way and recommendations for improving the accuracy of the differential data base for dosimetry reactions are presented.

  18. Reliability of performance measurements derived from ground reaction force data during countermovement jump and the influence of sampling frequency.

    Science.gov (United States)

    Hori, Naruhiro; Newton, Robert U; Kawamori, Naoki; McGuigan, Michael R; Kraemer, William J; Nosaka, Kazunori

    2009-05-01

    Force platforms are used extensively to measure force and power output during countermovement jump (CMJ). The purpose of this study was to examine measurement reliability and validity of commonly used performance measurements derived from ground reaction force (GRF)-time data during CMJ and the influence of sampling at different frequencies. Twenty-four men performed 2 trials of CMJ on a force platform, and GRF-time data were sampled at a rate of 500 Hz. Data obtained at 500 Hz were considered as the reference, and then data were resampled at 400, 250, 200, 100, 50, and 25 Hz, using interpolation. Commonly used power, force, and velocity performance measures were obtained from GRF-time data. Reliability was assessed by intraclass correlation coefficient (ICC) and coefficient of variation (CV) between the 2 trials within the session. Peak power, peak force, and peak velocity were highly reliable across all sampling frequencies (ICC = 0.92-0.98, CV = 1.3-4.1). Percentage differences from 500-Hz reference values ranged from -0.85 to 0.20% at 400 Hz, -1.88 to 0.89% at 250 Hz, -1.80 to 1.31% at 200 Hz, -3.63 to 3.34% at 100 Hz, -11.37 to 6.51% at 50 Hz, and -13.17 to 9.03% at 25 Hz. In conclusion, peak power, force, and velocity measurements derived from GRF to assess leg extensor capabilities are reliable within a test session except for peak rate of force development and time to peak power. With regard to sampling frequency, scientists and practitioners may consider sampling as low as 200 Hz, depending on the purpose of measurement, because the percentage difference is not markedly enlarged until the frequency is 100 Hz or lower.

  19. Neutron cross-section of {sup 34}S(n,{gamma}){sup 35}S reaction preliminary measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira Junior, Felisberto Alves; Maidana, Nora Lia; Vanin, Vito Roberto [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica; Koskinas, Marina Fallone; Dias, Mauro da Silva [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Roma, Josep Sempau [Universitat Politecnica de Catalunya (Spain)

    2011-07-01

    Full text: The thermal neutron cross-section for {sup 34}S(n,{gamma}){sup 35}S reaction was measured more than one decade ago and the obtained values are discrepant. This time, we irradiated two samples of natural sulfur (with 4.21(8)% of {sup 34}S) simultaneously, along with Au-Al alloy (0.1 % of gold) to monitor the neutron flux, using the well-known cross-section value of the {sup 197}Au(n,{gamma}){sup 198}Au reaction. One pair sample and monitor was irradiated bared and other pair inside cadmium cover about 0.5 mm thickness, to apply the cadmium difference method. The irradiation was performed near the core of the research reactor IEA-R1 IPEN (Nuclear Energy Research Institute in Sao Paulo, Brazil). The flux monitor activities were measured using a High Purity Germanium detector. The residual activity of the {sup 35}S , which is a pure {beta}{sup -} emitter, was measured in a 4{pi}{beta}-{gamma} calibration system, composed of a gas-flow proportional counter coupled to a pair of NaI(Tl) crystals operating in coincidence. The beta activity of {sup 35}S was determined through the extrapolation method associated with the tracer method, where the irradiated natural sulfur is dissolved in carbon disulfide and mixed with a solution containing the tracer, {sup 60}Co. An amount of the resulting solution was dropped in a substrate of collodion. After the first measurement, both sides of the source were covered with absorbers of collodion or aluminum and new measurements were taken. This process was repeated some times, reducing gradually the {beta}-{gamma} coincidence counting efficiency. The resulting complex behavior of the {beta}, {gamma} and coincidence detection efficiency was simulated by Monte Carlo method using modified penelope subroutines. The {sup 35}S activity was obtained by the extrapolation to 100% {beta} efficiency fitting parameterized simulations results to the experimental data by least squares method. (author)

  20. Measurement of gamma-ray production cross sections in neutron-induced reactions for Al and Pb

    International Nuclear Information System (INIS)

    Pavlik, A.; Vonach, H.; Hitzenberger, H.

    1995-01-01

    The prompt gamma-radiation from the interaction of fast neutrons with aluminum and lead was measured using the white neutron beam of the WNR facility at the Los Alamos National Laboratory. The samples (Al and isotopically enriched 207 Pb and 208 Pb) were positioned at about 20 m or 41 m distance from the neutron production target. The spectra of the emitted gamma-rays were measured with a high-resolution HPGe detector. The incident neutron energy was determined by the time-of-flight method and the neutron fluence was measured with a U fission chamber. From the aluminum gamma-ray spectra excitation functions for prominent gamma-transitions in various residual nuclei (in the range from O to Al) were derived for neutron energies from 3 MeV to 400 MeV. For lead (n,xnγ) reactions were studied for neutron energies up to 200 MeV by analyzing prominent gamma-transitions in the residual nuclei 200,202,204,206,207,208 Pb. The experimental results were compared with nuclear model calculations using the code GNASH. A good overall agreement was obtained without special parameter adjustments

  1. Psychometric properties of reaction time based experimental paradigms measuring anxiety-related information-processing biases in children.

    Science.gov (United States)

    Brown, H M; Eley, T C; Broeren, S; Macleod, C; Rinck, M; Hadwin, J A; Lester, K J

    2014-01-01

    Theoretical frameworks highlight the importance of threat-related information-processing biases for understanding the emergence of anxiety in childhood. The psychometric properties of several tasks measuring these biases and their associations with anxiety were examined in an unselected sample of 9-year-old children (N=155). In each task, threat bias was assessed using bias scores reflecting task performance on threat versus non-threat conditions. Reliability was assessed using split-half and test-retest correlations of mean reaction times (RTs), accuracy and bias indices. Convergence between measures was also examined. Mean RTs showed substantial split-half and test-retest correlations. Bias score reliability coefficients were near zero and non-significant, suggesting poor reliability in children of this age. Additionally, associations between bias scores and anxiety were weak and inconsistent and performance between tasks showed little convergence. Bias scores from RT based paradigms in the current study lacked adequate psychometric properties for measuring individual differences in anxiety-related information-processing in children. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. On-line measurements of nitro organic compounds emitted from automobiles by proton transfer reaction mass spectrometry: Laboratory experiments and a field measurement

    Science.gov (United States)

    Inomata, S.; Tanimoto, H.; Fujitani, Y.; Fushimi, A.; Sato, K.; Sekimoto, K.; Yamada, H.; Hori, S.; Shimono, A.; Hikida, T.

    2011-12-01

    On-line measurements of nitro organic compounds in automobile exhaust were carried out by proton transfer reaction mass spectrometry (PTR-MS) with a chassis dynamometer. Diesel vehicles with oxidation catalyst system (diesel vehicle A) and with diesel PM-NOx reduction system ((diesel vehicle B) and a gasoline vehicle were used as a test vehicle. In the case of the diesel vehicle A, the emissions of nitromethane, nitrophenol (NPh), C7-, C8-, C9-, and C10-nitrophenols, and dihydroxynitrobenzenes (DHNB) were observed in the diesel exhaust from the experiment under the constant driving at 60 km hr-1. Temporal variations of mixing ratios for nitromethane, NPh, and DHNB along with related volatile organic compounds (VOCs) were measured during a transient driving cycle. The time-resolved measurement revealed that the nitromethane emission was strongly correlated with the emissions of CO, benzene, and acetone, which are relatively quickly produced in acceleration processes and appeared as sharp peaks. On the other hand, the NPh emission was moderately correlated with the emissions of acetic acid and phenol, which peaks were broad. The emission of nitromethane was observed from the exhaust of the diesel vehicle B but the emission of other nitro organic compounds was not observed. This suggests that the emission of nitro organic compounds besides nitromethane may depend on the diesel exhaust aftertreatment devices. The emission of nitromethane was also observed from the exhaust of the gasoline vehicle with cold start. An in-situ measurement of nitro organic compounds and their related VOCs was carried out at the crossing of an urban city, Kawasaki. Nitromethane was observed at the crossing and we found that the concentration of nitrometane varied rapidly. During the measurement, the maximum of the concentration of nitrometane reached 5 ppbv. Not only nitrophenols but also nitroaromatics were sometimes detected in the field measurement.

  3. Measurements of Volatile Organic Compounds Using Proton Transfer Reaction – Mass Spectrometry during the MILAGRO 2006 Campaign

    Directory of Open Access Journals (Sweden)

    E. C. Fortner

    2009-01-01

    Full Text Available Volatile organic compounds (VOCs were measured by proton transfer reaction – mass spectrometry (PTR-MS on a rooftop in the urban mixed residential and industrial area North Northeast of downtown Mexico City as part of the Megacity Initiative – Local and Global Research Observations (MILAGRO 2006 field campaign. Thirty eight individual masses were monitored during the campaign and many species were quantified including methanol, acetaldehyde, toluene, the sum of C2 benzenes, the sum of C3 benzenes, acetone, isoprene, benzene, and ethyl acetate. The VOC measurements were analyzed to gain a better understanding of the type of VOCs present in the MCMA, their diurnal patterns, and their origins. Diurnal profiles of weekday and weekend/holiday aromatic VOC concentrations showed the influence of vehicular traffic during the morning rush hours and during the afternoon hours. Plumes including elevated toluene as high as 216 parts per billion (ppb and ethyl acetate as high as 183 ppb were frequently observed during the late night and early morning hours, indicating the possibility of significant industrial sources of the two compounds in the region. Wind fields during those peak episodes revealed no specific direction for the majority of the toluene plumes but the ethyl acetate plumes arrived at the site when winds were from the Southwest or West. The PTR-MS measurements combined with other VOC measuring techniques at the field site as well as VOC measurements conducted in other areas of the Mexico City Metropolitan Area (MCMA will help to develop a better understanding of the spatial pattern of VOCs and its variability in the MCMA.

  4. Identification of 2-enolbutyrate as the product of the reaction of maize leaf phosphoenolpyruvate carboxylase with (Z)- and (E)-2-phosphoenolbutyrate: evidence from NMR and kinetic measurements

    International Nuclear Information System (INIS)

    Gonzalez, D.H.; Andreo, C.S.

    1988-01-01

    (Z)- and (E)-2-phosphoenolbutyrates were dephosphorylated at similar rates by phosphoenolpyruvate carboxylase purified from maize leaves, as determined from proton nuclear magnetic resonance measurements. The product of the reaction in D 2 O was a mixture of 60-70% 2-oxo[3-H,D]butyrate, 25-30% 2-oxo[3-D 2 ] butyrate, and 5-10% 2-oxo[3-H 2 ] butyrate. The amounts of (R)- and (S)-2-oxo[3-H,D] butyrate in this mixture were determined by exchange at C-3 in D 2 O catalyzed by pyruvate kinase as described previously. Forty-five minutes after the addition of pyruvate kinase, the proportions of 2-oxo[3-H,D] butyrate and 2-oxo[3-D 2 ]-butyrate were 36-39% and 61-64%, respectively, indicating that the original mixture contained equal amounts of R and S enantiomers. In addition, a compound with properties similar to those of enolpyruvate was detected in solution during the action of phosphoenolpyruvate carboxylase on 2-phosphoenolbutyrate. This compound, most likely 2-enolbutyrate, presented maximum light absorption at 220-230 nm and was ketonized in a solution containing 80% D 2 O and 20% H 2 O (pH 7) with a rate constant of 1.33 min -1 . From these results, it is concluded that the actual product released from the active site of phosphoenolpyruvate carboxylase during the reaction with 2-phosphoenolbutyrate is the enolic form of 2-oxobutyrate and that protonation of this form takes place at random in solution

  5. Measurement of the inelastic branch of the $^{14}$O(α,p)$^{17}$F reaction Implications for explosive burning in novae and x-ray bursters

    CERN Document Server

    He, J J; Davinson, T; Aliotta, M; Büscher, J; Clement, E; Delahaye, P; Hass, M; Jenkins, D G; Kumar, V; Murphy, A St J; Neyskens, P; Raabe, R; Robinson, A P; Voulot, D; van der Walle, J; Warr, N; Wenander, F

    2009-01-01

    A measurement of the inelastic component of the key astrophysical resonance in the 14O(α,p)17F reaction for burning and breakout from hot carbon-nitrogen-oxygen (CNO) cycles is reported. The inelastic component is found to be comparable to the ground-state branch and will enhance the 14O(α,p)17F reaction rate. The current results for the reaction rate confirm that the 14O(α,p)17F reaction is unlikely to contribute substantially to burning and breakout from the CNO cycles under novae conditions. The reaction can, however, contribute strongly to the breakout from the hot CNO cycles under the more extreme conditions found in x-ray bursters.

  6. Measurement of the D(d,p)T reaction in Ti for 2.5 d < 6.5 keV and electron screening in metal

    International Nuclear Information System (INIS)

    Yuki, Hideyuki; Sato, Takehiko; Ohtsuki, Tsutomu; Yorita, Tetsuhiko; Aoki, Yuka; Yamazaki, Hirohito; Kasagi, Jirohta; Ishii, Keizo.

    1997-01-01

    In order to study the electron screening effect on low-energy nuclear reactions in metals, the D+D reaction in Ti was investigated. Measured were thick target yields of protons emitted in the D(d,p)T reaction from the bombardment of Ti metal with deuteron energies between 2.5 and 6.5 keV. The obtained yields were compared with those predicted by using the parameterization of cross sections at higher energies. It was found that the reaction rates in Ti are slightly enhanced over those of the bare D+D reaction for E d < 4.3 keV, and the enhancement can be interpreted as caused by the electron screening. The electron screening potential in Ti is deduced for the first time to be 19 ± 12 eV. (author)

  7. Selected-ion flow tube temperature-dependent measurements for the reactions of O{sub 2}{sup +} with N atoms and N{sub 2}{sup +} with O atoms

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Oscar; Sanchez, Jenny C.; Ard, Shaun G.; Melko, Joshua J.; Shuman, Nicholas S.; Viggiano, Albert A., E-mail: afrl.rvborgmailbox@kirtland.af.mil [Space Vehicles Directorate, Air Force Research Laboratory, Kirtland AFB, New Mexico 87117-5776 (United States); Li, Anyang; Guo, Hua [Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131 (United States)

    2015-04-21

    The temperature variation of rate constants has been measured for the gas phase reactions of the oxycation O{sub 2}{sup +} with N atoms and of N{sub 2}{sup +} with O atoms from 120 to 400 K using a variable temperature-selected ion flow tube. Measured room temperature rate constants, 0.75 × 10{sup −10} cm{sup 3} s{sup −1} (±30%) for O{sub 2}{sup +} with N and 1.4 × 10{sup −10} cm{sup 3} s{sup −1} (±30%) for N{sub 2}{sup +} with O, are in agreement with previously reported values. A temperature dependence of T{sup −0.7(±0.3)} is observed for the O{sub 2}{sup +} + N reaction; however, the N{sub 2}{sup +} + O reaction is found to be independent of temperature. Calculations at varying levels of theory were used in tandem with experiments to evaluate likely pathways in potential energy surfaces for the reactions of concern.

  8. Measuring the cosmic ray muon-induced fast neutron spectrum by (n,p) isotope production reactions in underground detectors

    International Nuclear Information System (INIS)

    Galbiati, Cristiano; Beacom, John F.

    2005-01-01

    While cosmic ray muons themselves are relatively easy to veto in underground detectors, their interactions with nuclei create more insidious backgrounds via (i) the decays of long-lived isotopes produced by muon-induced spallation reactions inside the detector (ii) spallation reactions initiated by fast muon-induced neutrons entering from outside the detector, and (iii) nuclear recoils initiated by fast muon-induced neutrons entering from outside the detector. These backgrounds, which are difficult to veto or shield against; are very important for solar, reactor, dark matter, and other underground experiments, especially as increased sensitivity is pursued. We used FLUKA to calculate the production rates and spectra of all prominent secondaries produced by cosmic ray muons, in particular focusing on secondary neutrons, because of their importance. Since the neutron spectrum is steeply falling, the total neutron production rate is sensitive to just the relatively soft neutrons and not the fast-neutron component. We show that the neutron spectrum in the range ∼10-100 MeV can instead be probed by the (n,p)-induced isotope production rates 12 C(n,p) 12 B and 16 O(n,p) 16 N in oil- and water-based detectors. The result for 12 B is in good agreement with the recent KamLAND measurement. Besides testing the calculation of muon secondaries, these results are also of practical importance, since 12 B (T 1/2 =20.2 ms, Q=13.4 MeV) and 16 N (T 1/2 =7.13 s, Q=10.4 MeV) are among the dominant spallation backgrounds in these detectors

  9. Measurement of thermal neutron cross-section and resonance integral for the 165Ho(n,γ) 166gHo reaction using electron linac-based neutron source

    Science.gov (United States)

    Nguyen, Van Do; Pham, Duc Khue; Kim, Tien Thanh; Kim, Guinyun; Lee, Manwoo; Kim, Kyung Sook; Kang, Heung-Sik; Cho, Moo-Hyun; Ko, In Soo; Namkung, Won

    2011-01-01

    The thermal neutron cross-section and the resonance integral of the 165Ho(n,γ) 166gHo reaction have been measured by the activation method using a 197Au(n,γ) 198Au monitor reaction as a single comparator. The high-purity natural Ho and Au foils with and without a cadmium shield case of 0.5 mm thickness were irradiated in a neutron field of the Pohang neutron facility. The induced activities in the activated foils were measured with a calibrated p-type high-purity Ge detector. The correction factors for the γ-ray attenuation ( Fg), the thermal neutron self-shielding ( Gth), the resonance neutron self-shielding ( Gepi) effects, and the epithermal neutron spectrum shape factor ( α) were taken into account. The thermal neutron cross-section for the 165Ho(n,γ) 166gHo reaction has been determined to be 59.7 ± 2.5 barn, relative to the reference value of 98.65 ± 0.09 barn for the 197Au(n,γ) 198Au reaction. By assuming the cadmium cut-off energy of 0.55 eV, the resonance integral for the 165Ho(n,γ) 166gHo reaction is 671 ± 47 barn, which is determined relative to the reference value of 1550 ± 28 barn for the 197Au(n,γ) 198Au reaction. The present results are, in general, good agreement with most of the previously reported data within uncertainty limits.

  10. Highlights from the previous volumes

    Science.gov (United States)

    Jacopo, Iacovacci; Takahiro, Kohsokabe; Kunihiko, Kaneko; al., Lange Steffen et; al., Helden Laurent et; et al.

    2017-04-01

    Functional Multiplex PageRank: The centrality is a functionPattern formation induced by fixed boundary conditionPower-law distributed Poincaré recurrences in higher-dimensional systemsMeasurement of second-order response without perturbation

  11. Cross-section and analyzing-power measurements for the sup 2 H(n,pn)n reaction at 189 MeV

    CERN Document Server

    Anderson, B D; Sowinski, J; Baldwin, A R; Franklin, W; Watson, J W; Wissink, S; Wolanski, M; Yang, G; Glöckle, W; Witala, H

    2000-01-01

    We measured cross sections and analyzing powers for the sup 2 H(n,n) sup 2 H and sup 2 H(n,pn)n reactions at 189 MeV at the Indiana University Cyclotron Facility (IUCF). These measurements are designed to search for evidence of three-body forces in the nuclear force and have the advantage that the Coulomb force is not involved. The analyzing-power measurements for the sup 2 H(n,n) sup 2 H reaction are in close agreement with those from the analog sup 2 H(p,p) sup 2 H reaction at nearby energies and do not agree quantitatively with available three-body, Faddeev calculations, either with or without three-body forces included. The sup 2 H(n,pn)n measurements are still under analysis.

  12. The benefits of adding a brief measure of simple reaction time to the assessment of executive function skills in early childhood.

    Science.gov (United States)

    Willoughby, Michael T; Blair, Clancy B; Kuhn, Laura J; Magnus, Brooke E

    2018-06-01

    Early childhood represents a period of rapid cognitive developmental change in executive function (EF) skills along with a variety of related cognitive processes, including processing speed. This leads to interpretational challenges in that children's performance on EF tasks reflects more than EF skills per se. We tested whether the inclusion of a brief measure of simple reaction time (SRT) during EF assessments could help to partially address this challenge. Data were drawn from a cross-sectional convenience sample of 830 preschool-aged children. Individual differences in SRT were significantly associated with performance on all tasks (R 2 s = .09-.26); slower performance on the SRT task was associated with poorer performance on each EF task. Age-related differences in individual EF tasks were reduced by approximately one half after accounting for age-related differences in SRT, and EF task scores were less coherent (i.e., less strongly intercorrelated with each other) after the removal of SRT. Age-related differences in EF were smaller (Cohen ds = 1.36 vs. 0.78), and poverty-related differences in EF were larger (Cohen ds = 0.30 vs. 0.46) after accounting for SRT-related variation. Finally, consistent with previous studies, SRT-related differences in fluid reasoning were mediated by EF skills. Results are discussed with respect to using a brief measure of SRT to partially address the problem of measurement impurity at the level of individual EF tasks. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. A kinetic study of the suicide inactivation of an enzyme measured through coupling reactions. Application to the suicide inactivation of tyrosinase.

    Science.gov (United States)

    Escribano, J; Tudela, J; Garcia-Carmona, F; Garcia-Canovas, F

    1989-01-01

    A systematic procedure for the kinetic study of reaction mechanisms with enzyme inactivation induced by a suicide substrate in the presence or in the absence of an auxiliary substrate, when the enzyme activity is measured through coupling reactions, enzymically catalysed or not, was developed and analysed by using the transient-phase approach. The methodology is established to determine the parameters and kinetic constants corresponding to the enzyme suicide inactivation and the coupling reactions. This approach is illustrated by a study of the suicide inactivation of tyrosinase by catechol in the presence of L-proline. Treatment of the experimental data was carried out by non-linear regression. PMID:2508631

  14. Analysis of FeF3 and NiF2 thin films by using RBS, (α, X) reactions, and SIMS measurements

    International Nuclear Information System (INIS)

    Gevers, G.; Barriere, A.S.; Grannec, J.; Lozano, L.; Blanchard, B.

    1984-01-01

    The composition of FeF 3 and NiF 2 thin films, prepared by sublimation under vacuum, is investigated from several complementary analysis techniques (RBS, α, X reactions, and SIMS measurements). It greatly depends on fabrication parameters and further treatments. For a residual pressure in the preparation enclosure less than 10 -7 Torr and a temperature, T/sub s/, of the substrate during the condensation of the vapour greater than 400 K for FeF 3 and lower than 550 K for NiF 2 , the bulk composition of the layers is quasi stoichiometric. A lack of fluorine is observed near the two faces of the films. It is correlated to the presence of oxygen which probably corresponds to water adsorption, after an air exposure of the samples, followed by an hydrolysis of the compounds. This effect is considerably reduced by the presence of gold electrodes which protect the insulating layers, and in the conditions previously mentioned any diffusion can be noted. However in all cases some traces of impurities are pointed out, mainly: sodium, potassium, calcium, and chlorine, which are probably present in the initial powder. On the other hand, it is shown that FeF 3 diffuses throughout a gold electrode for T/sub s/ 2 , the content of fluorine decreases when T/sub s/ > 550 K or when the films are annealed. (author)

  15. Peripheral collisions in Ar induced reactions between 27 and 44 A.MeV: study of energy dissipation by measuring the correlated neutron multiplicities

    International Nuclear Information System (INIS)

    Guerreau, D.; Doubre, H.; Galin, J.; Pouthas, J.; Jahnke, U.; Jiang, D.X.; Lott, B.; Jacquet, D.

    1988-01-01

    A 4 π detector measuring the neutron multiplicities has been used to investigate the energy dissipation during peripheral collisions in Ar induced reactions around the Fermi Energy. Besides the persistance of direct transfer reactions for the most peripheral collisions, there are strong evidences for the occurrence of quite large energy dissipation, a clear signature for the one body friction to still play a major role at these intermediate energies

  16. High-energy γ-rays measured in coincidence with α-particles in the reaction 19F+12C at Elab=121.7MeV

    International Nuclear Information System (INIS)

    Van Schagen, J.P.S.; Amorini, F.; Cardella, G.; Croce, R.; DiPietro, A.; Musumarra, A.; Papa, M.; Pappalardo, G.; Rizzo, F.; Campajola, L.; DeRosa, A.; D'Onofrio, A.; Inglima, G.; La Commara, M.; Pierroutsakou, D.; Rocca, V.; Romano, M.; Romoli, M.; Sandoli, M.; Terrasi, F.

    1995-01-01

    The yield of γ-rays emitted in the dissipative reaction 19 F+ 12 C, at E lab =121.7MeV has been measured in coincidence with α-particles emitted at θ lab =10 . Comparison with preliminary statistical model calculations shows that assuming only compound nucleus formation is not sufficient to reproduce the data. Other mechanisms have to be included before information on reaction dynamics can be extracted and definitive conclusions can be drawn. ((orig.))

  17. A wearable force plate system for the continuous measurement of triaxial ground reaction force in biomechanical applications

    International Nuclear Information System (INIS)

    Liu, Tao; Inoue, Yoshio; Shibata, Kyoko

    2010-01-01

    The ambulatory measurement of ground reaction force (GRF) and human motion under free-living conditions is convenient, inexpensive and never restricted to gait analysis in a laboratory environment and is therefore much desired by researchers and clinical doctors in biomedical applications. A wearable force plate system was developed by integrating small triaxial force sensors and three-dimensional (3D) inertial sensors for estimating dynamic triaxial GRF in biomechanical applications. The system, in comparison to existent systems, is characterized by being lightweight, thin and easy-to-wear. A six-axial force sensor (Nitta Co., Japan) was used as a verification measurement device to validate the static accuracy of the developed force plate. To evaluate the precision during dynamic gait measurements, we compared the measurements of the triaxial GRF and the center of pressure (CoP) by using the developed system with the reference measurements made using a stationary force plate and an optical motion analysis system. The root mean square (RMS) differences of the two transverse components (x- and y-axes) and the vertical component (z-axis) of the GRF were 4.3 ± 0.9 N, 6.0 ± 1.3 N and 12.1 ± 1.1 N, respectively, corresponding to 5.1 ± 1.1% and 6.5 ± 1% of the maximum of each transverse component and 1.3 ± 0.2% of the maximum vertical component of GRF. The RMS distance between the two systems' CoP traces was 3.2 ± 0.8 mm, corresponding to 1.2 ± 0.3% of the length of the shoe. Moreover, based on the results of the assessment of the influence of the system on natural gait, we found that gait was almost never affected. Therefore, the wearable system as an alternative device can be a potential solution for measuring CoP and triaxial GRF in non-laboratory environments

  18. Measurements of proton total reaction cross sections for 6Li,7Li,14N,20Ne and 40Ar between 23 and 49 MeV

    International Nuclear Information System (INIS)

    Carlson, R.F.; Cox, A.J.; Nasr, T.N.; De Jong, M.S.; Ginther, D.I.; Hasell, D.K.; Sourkes, A.M.; Van Oers, W.T.H.; Margaziotis, D.J.

    1985-01-01

    Measurements of proton total reaction cross sections for 6 Li, 7 Li, 14 N, 20 Ne and 40 Ar have been made in the energy range 23 to 49 MeV, using a variation of a standard attenuation technique. The measured cross sections are compared with optical-model and nuclear-transparency calculations. (orig.)

  19. Micro-Membrane Electrode Assembly Design to Precisely Measure the in Situ Activity of Oxygen Reduction Reaction Electrocatalysts for PEMFC.

    Science.gov (United States)

    Long, Zhi; Li, Yankai; Deng, Guangrong; Liu, Changpeng; Ge, Junjie; Ma, Shuhua; Xing, Wei

    2017-06-20

    An in situ micro-MEA technique, which could precisely measure the performance of ORR electrocatalyst using Nafion as electrolyte, was designed and compared with regular thin-film rotating-disk electrode (TFRDE) (0.1 M HClO 4 ) and normal in situ membrane electrode assembly (MEA) tests. Compared to the traditional TFRDE method, the micro-MEA technique makes the acquisition of catalysts' behavior at low potential values easily achieved without being limited by the solubility of O 2 in water. At the same time, it successfully mimics the structure of regular MEAs and obtains similar results to a regular MEA, thus providing a new technique to simply measure the electrode activity without being bothered by complicated fabrication of regular MEA. In order to further understand the importance of in situ measurement, Fe-N-C as a typical oxygen reduction reaction (ORR) free-Pt catalyst was evaluated by TFRDE and micro-MEA. The results show that the half wave potential of Fe-N-C only shifted negatively by -135 mV in comparison with state-of-the-art Pt/C catalysts from TFRDE tests. However, the active site density, mass transfer of O 2 , and the proton transfer conductivity are found to strongly influence the catalyst activity in the micro-MEA, thereby resulting in a much lower limiting current density than Pt/C (8.7 times lower). Hence, it is suggested that the micro-MEA is better in evaluating the in situ ORR performance, where the catalysts are characterized more thoroughly in terms of intrinsic activity, active site density, proton transfer, and mass transfer properties.

  20. Study of the solid-state 'amorphization' reaction in Fe50Re50 by means of Moessbauer spectrometry and diffraction measurements

    International Nuclear Information System (INIS)

    Randrianantoandro, N.; Greneche, J.-M.; Cooper, R.J.; Cowlam, N.

    2002-01-01

    The solid-state 'amorphization' reaction produced by the mechanical alloying (MA) of the equiatomic alloy Fe 50 Re 50 has been studied using 57 Fe Moessbauer spectrometry plus x-ray and neutron diffraction. The percentages of iron atoms in the magnetic phases present in the reaction have been obtained from the Moessbauer spectra and the consumption of the parent elements derived from the reduction in intensity of their Bragg peaks in the diffraction patterns. The reaction in the Fe 50 Re 50 alloy appears to be 2-3 times slower than the reaction in the related Fe 58 Ta 42 alloy studied by us previously. A possible reason for this is the presence of an intermediate phase in the reaction revealed by the hyperfine structure at 57 Fe. This is identified as an iron-rich solid solution by the absence of any new Bragg peaks in the diffraction patterns. Although a small fraction of the rhenium remains unconsumed at the end of the reaction, the FeRe alloy obtained after 24 h of MA has a genuine amorphous structure, whose reduced radial distribution function G(r) is sensitive to the topological order present. (author)

  1. ^{7}Be(n,α)^{4}He Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN.

    Science.gov (United States)

    Barbagallo, M; Musumarra, A; Cosentino, L; Maugeri, E; Heinitz, S; Mengoni, A; Dressler, R; Schumann, D; Käppeler, F; Colonna, N; Finocchiaro, P; Ayranov, M; Damone, L; Kivel, N; Aberle, O; Altstadt, S; Andrzejewski, J; Audouin, L; Bacak, M; Balibrea-Correa, J; Barros, S; Bécares, V; Bečvář, F; Beinrucker, C; Berthoumieux, E; Billowes, J; Bosnar, D; Brugger, M; Caamaño, M; Calviani, M; Calviño, F; Cano-Ott, D; Cardella, R; Casanovas, A; Castelluccio, D M; Cerutti, F; Chen, Y H; Chiaveri, E; Cortés, G; Cortés-Giraldo, M A; Cristallo, S; Diakaki, M; Domingo-Pardo, C; Dupont, E; Duran, I; Fernandez-Dominguez, B; Ferrari, A; Ferreira, P; Furman, W; Ganesan, S; García-Rios, A; Gawlik, A; Glodariu, T; Göbel, K; Gonçalves, I F; González-Romero, E; Griesmayer, E; Guerrero, C; Gunsing, F; Harada, H; Heftrich, T; Heyse, J; Jenkins, D G; Jericha, E; Katabuchi, T; Kavrigin, P; Kimura, A; Kokkoris, M; Krtička, M; Leal-Cidoncha, E; Lerendegui, J; Lederer, C; Leeb, H; Lo Meo, S; Lonsdale, S J; Losito, R; Macina, D; Marganiec, J; Martínez, T; Massimi, C; Mastinu, P; Mastromarco, M; Mazzone, A; Mendoza, E; Milazzo, P M; Mingrone, F; Mirea, M; Montesano, S; Nolte, R; Oprea, A; Pappalardo, A; Patronis, N; Pavlik, A; Perkowski, J; Piscopo, M; Plompen, A; Porras, I; Praena, J; Quesada, J; Rajeev, K; Rauscher, T; Reifarth, R; Riego-Perez, A; Rout, P; Rubbia, C; Ryan, J; Sabate-Gilarte, M; Saxena, A; Schillebeeckx, P; Schmidt, S; Sedyshev, P; Smith, A G; Stamatopoulos, A; Tagliente, G; Tain, J L; Tarifeño-Saldivia, A; Tassan-Got, L; Tsinganis, A; Valenta, S; Vannini, G; Variale, V; Vaz, P; Ventura, A; Vlachoudis, V; Vlastou, R; Vollaire, J; Wallner, A; Warren, S; Weigand, M; Weiß, C; Wolf, C; Woods, P J; Wright, T; Žugec, P

    2016-10-07

    The energy-dependent cross section of the ^{7}Be(n,α)^{4}He reaction, of interest for the so-called cosmological lithium problem in big bang nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. The challenges posed by the short half-life of ^{7}Be and by the low reaction cross section have been overcome at n_TOF thanks to an unprecedented combination of the extremely high luminosity and good resolution of the neutron beam in the new experimental area (EAR2) of the n_TOF facility at CERN, the availability of a sufficient amount of chemically pure ^{7}Be, and a specifically designed experimental setup. Coincidences between the two alpha particles have been recorded in two Si-^{7}Be-Si arrays placed directly in the neutron beam. The present results are consistent, at thermal neutron energy, with the only previous measurement performed in the 1960s at a nuclear reactor. The energy dependence reported here clearly indicates the inadequacy of the cross section estimates currently used in BBN calculations. Although new measurements at higher neutron energy may still be needed, the n_TOF results hint at a minor role of this reaction in BBN, leaving the long-standing cosmological lithium problem unsolved.

  2. Measurement of the double polarization observable E in the reaction γp → pη′

    Directory of Open Access Journals (Sweden)

    Noreen Afzal Farah

    2012-12-01

    Full Text Available The main goal of the CBELSA/TAPS experiment is the investigation of the nucleon excitation spectrum, which consists of many overlapping resonances. In order to disentangle the different resonance contributions, a partial wave analysis is necessary. In the field of photoproduction of single pseudoscalar mesons, the measurement of a well chosen set of at least eight single and double polarization observables allows for the determination of an unambiguous solution. Of particular interest is the η′ meson since it couples only to resonances with isospin I = 12${m{I = }}{1 over 2}$, thus reducing the number of overlapping resonances. Additionally, its comparatively high mass gives access to the poorly understood regime of high-lying resonances. With the CBELSA/TAPS experiment at the electron stretcher accelerator ELSA, double polarization observables such as E can be obtained by studying photoproduction reactions using a circularly polarized photon beam in combination with a longitudinally polarized butanol target. The decay mode η′ → γγ was analyzed for a beam photon energy range of 1447-2350 MeV. The preliminary results for the double polarization observable E are shown.

  3. Measurement of the np→npπ0π0 reaction in search for the recently observed d⁎(2380 resonance

    Directory of Open Access Journals (Sweden)

    P. Adlarson

    2015-04-01

    Full Text Available Exclusive measurements of the quasi-free np→npπ0π0 reaction have been performed by means of dp collisions at Td=2.27 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region s=(2.35–2.46 GeV, which includes the region of the ABC effect and its associated d⁎(2380 resonance. Adding the d⁎ resonance amplitude to that for the conventional processes leads to a reasonable description of the data. The observed resonance effect in the total cross section is in agreement with the predictions of Fäldt and Wilkin as well with those of Albadajedo and Oset. The ABC effect, i.e. the low-mass enhancement in the π0π0-invariant mass spectrum, is found to be very modest – if present at all, which might pose a problem to some of its interpretations.

  4. Analyzing power measurements for the d+d-d+p+n breakup reaction at 12MeV

    Energy Technology Data Exchange (ETDEWEB)

    Felsher, P.D.; Howell, C.R.; Tornow, W.; Roberts, M.L.; Hanly, J.K.; Weisel, G.J,; Ohali, M. Al; Walter, R.L.; Slaus, I.; Lambert, J.M.; Treado, P.A.; Mertens, G.; Fonseca, G.; Soldi, A.; Vlahovic, B.

    1997-07-10

    We report the most extensive set of vector iT11 and tensor T20 and T22 analyzing-power for the d=d-d=p=n reaction. Two-particle coincidence data have been measured for six deuteron-proton, three deuteron-neutron and three proton-neutron angle pairs at an incident deuteron energy of 12.0MeV. These data are compared to impulse-approximation calculations that threat the underlying nucleon-deuteron system exactly and include contributions from both target and projectile breakup processes. This model gives a good description of the analyzing-power and relative cross-section data. We show that the inclusion of nucleon-nucleon P interactions considerably improves the agreement with the spin observables. The disagreement between the data and theoretical predictions show the limitations in our model and the importance of the rescattering processes. We suggest that the d+d three-body breakup process will provide useful information on the nucleon-nucleon force when exact calculations become available. [S0556-2813(97)02907-5

  5. Measurement of the Plasma Astrophysical S Factor for the He3(d,p)He4 Reaction in Exploding Molecular Clusters

    Science.gov (United States)

    Barbui, M.; Bang, W.; Bonasera, A.; Hagel, K.; Schmidt, K.; Natowitz, J. B.; Burch, R.; Giuliani, G.; Barbarino, M.; Zheng, H.; Dyer, G.; Quevedo, H. J.; Gaul, E.; Bernstein, A. C.; Donovan, M.; Kimura, S.; Mazzocco, M.; Consoli, F.; De Angelis, R.; Andreoli, P.; Ditmire, T.

    2013-08-01

    The plasma astrophysical S factor for the He3(d,p)He4 fusion reaction was measured for the first time at temperatures of few keV, using the interaction of intense ultrafast laser pulses with molecular deuterium clusters mixed with He3 atoms. Different proportions of D2 and He3 or CD4 and He3 were mixed in the gas target in order to allow the measurement of the cross section for the He3(d,p)He4 reaction. The yield of 14.7 MeV protons from the He3(d,p)He4 reaction was measured in order to extract the astrophysical S factor at low energies. Our result is in agreement with other S factor parametrizations found in the literature.

  6. Extracting integrated and differential cross sections in low-energy heavy-ion reactions from backscattering measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sargsyan, V.V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Yerevan State University, Yerevan (Armenia); Adamian, G.G.; Antonenko, N.V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Diaz-Torres, A. [European Centre for Theoretical Studies in Nuclear Physics and Related Areas, Villazzano (Italy); Gomes, P.R.S. [Universidade Federal Fluminense, Instituto de Fisica, Niteroi (Brazil); Lenske, H. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, Giessen (Germany)

    2014-11-15

    We suggest new methods to extract elastic (quasi-elastic) scattering angular distribution and reaction (capture) cross sections from the experimental elastic (quasi-elastic) backscattering excitation function taken at a single angle. A novel Coulomb scattering relation between angular momentum and centrifugal energy is used. The methodology is developed for addressing complementary reaction observables, improving the description of elastic differential cross section. (orig.)

  7. Reaction rate sensitivity of 44Ti production in massive stars and implications of a thick target yield measurement of 40Ca(alpha,gamma)44Ti

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, R D; Sheets, S A; Burke, J T; Scielzo, N D; Rauscher, T; Norman, E B; Tumey, S; Brown, T A; Grant, P G; Hurst, A M; Phair, L; Stoyer, M A; Wooddy, T; Fisker, J L; Bleuel, D

    2010-02-16

    We evaluate two dominant nuclear reaction rates and their uncertainties that affect {sup 44}Ti production in explosive nucleosynthesis. Experimentally we develop thick-target yields for the {sup 40}Ca({alpha},{gamma}){sup 44}Ti reaction at E{sub {alpha}} = 4.13, 4.54, and 5.36 MeV using {gamma}-ray spectroscopy. At the highest beam energy, we also performed an activation measurement which agrees with the thick target result. From the measured yields a stellar reaction rate was developed that is smaller than current statistical-model calculations and recent experimental results, which would suggest lower {sup 44}Ti production in scenarios for the {alpha}-rich freeze out. Special attention has been paid to assessing realistic uncertainties of stellar reaction rates produced from a combination of experimental and theoretical cross sections. With such methods, we also develop a re-evaluation of the {sup 44}Ti({alpha},p){sup 47}V reaction rate. Using these two rates we carry out a sensitivity survey of {sup 44}Ti synthesis in eight expansions representing peak temperature and density conditions drawn from a suite of recent supernova explosion models. Our results suggest that the current uncertainty in these two reaction rates could lead to as large an uncertainty in {sup 44}Ti synthesis as that produced by different treatments of stellar physics.

  8. REACTION RATE SENSITIVITY OF 44Ti PRODUCTION IN MASSIVE STARS AND IMPLICATIONS OF A THICK TARGET YIELD MEASUREMENT OF 40Ca(α, γ)44Ti

    International Nuclear Information System (INIS)

    Hoffman, R. D.; Sheets, S. A.; Burke, J. T.; Scielzo, N. D.; Norman, E. B.; Tumey, S.; Brown, T. A.; Grant, P. G.; Hurst, A. M.; Stoyer, M. A.; Wooddy, T.; Fisker, J. L.; Bleuel, D.; Rauscher, T.; Phair, L.

    2010-01-01

    We evaluate two dominant nuclear reaction rates and their uncertainties that affect 44 Ti production in explosive nucleosynthesis. Experimentally we develop thick target yields for the 40 Ca(α, γ) 44 Ti reaction at E α = 4.13, 4.54, and 5.36 MeV using γ-ray spectroscopy. At the highest beam energy, we also performed an activation measurement which agrees with the thick target result. From the measured yields a stellar reaction rate was developed that is smaller than current statistical-model calculations and recent experimental results, which would suggest lower 44 Ti production in scenarios for the α-rich freezeout. Special attention has been paid to assessing realistic uncertainties of stellar reaction rates produced from a combination of experimental and theoretical cross sections. With such methods, we also develop a re-evaluation of the 44 Ti(α, p) 47 V reaction rate. Using these two rates we carry out a sensitivity survey of 44 Ti synthesis in eight expansions representing peak temperature and density conditions drawn from a suite of recent supernova explosion models. Our results suggest that the current uncertainty in these two reaction rates could lead to as large an uncertainty in 44 Ti synthesis as that produced by different treatments of stellar physics.

  9. Measurement of excitation functions and isomeric ratios of the 197Au(3He,xn)200- sup(x)Tl reactions, where x=2,3 and 4

    International Nuclear Information System (INIS)

    Vinagre Filho, U.M.

    1983-01-01

    The excitation functions and isomer ratios of the 197 Au( 3 He,xn) 200- sup(x)Tl reactions, with x = 2, 3 and 4, were measured at bombarding energies in the range from 15 to 36 MeV. The measured values were compared to those obtained with the use of the statistical an hybrid modeles, calculated by the ALICE code. Best fit was achieved using the simple statistical model. The results were also compared to those found in literature for the ( 3 He,xn) and ( 4 He,xn) reactions in gold. (Author) [pt

  10. First Measurement of the Radionuclide Purity of the Therapeutic Isotope 67Cu Produced by 68Zn(n,x) Reaction Using natC(d,n) Neutrons

    Science.gov (United States)

    Sato, Nozomi; Tsukada, Kazuaki; Watanabe, Satoshi; Ishioka, Noriko S.; Kawabata, Masako; Saeki, Hideya; Nagai, Yasuki; Kin, Tadahiro; Minato, Futoshi; Iwamoto, Nobuyuki; Iwamoto, Osamu

    2014-07-01

    We have for the first time studied the radionuclide purity of the therapeutic isotope 67Cu produced by the 68Zn(n,x)67Cu reaction. The neutrons were obtained by the natC(d,n) reaction using 40 MeV deuterons. We measured the γ-ray spectra of the reaction products produced by bombarding an enriched 68ZnO sample with the neutrons with a high-purity Ge detector. We found that the relative production yields of the impurity radionuclides 64Cu, 65Zn, and 69mZn to 67Cu are extremely low. The result indicates that the 68Zn(n,x)67Cu reaction is the most promising among those proposed routes until now for producing high-quality 67Cu, and could solve a longstanding problem of establishing an appropriate production method for 67Cu.

  11. Measurement and analysis of the excitation function and isomeric cross section ratios for α-induced reaction on Ir, Au, Re and Ta nuclei

    International Nuclear Information System (INIS)

    Ismail, M.

    1998-01-01

    Excitation functions and a few isomeric cross section ratios for production of (1) 192 Au, 193 Au, 194 Au, 195 Au and 192 Ir nuclides in α-induced reactions on 191,193 Ir, (2) 197 Tl, 197m Hg, 198m.g Tl, 199 Tl and 200 Tl nuclides in α-induced reaction in 197 Au and (3) 183 Re and 184m.g Re nuclides in α-induced reaction in 181 Ta and 185 Re are obtained from the measurements of the residual activities by the conventional stacked-foils technique from threshold to 50 MeV. The excitation function and isomeric cross section ratios for nuclear reaction 181 Ta (α,n) 184m.g Re are compared with the theoretical calculation using the code Stapre which is based on exciton model for pre-equilibrium phase and Hauser-Feshbach formalism taking angular momentum and parity into account for the equilibrium phase of the nuclear reaction. All other experimental excitation functions are compared with the calculations considering equilibrium as well as pre-equilibrium reaction mechanism according to the geometry dependent hybrid (GDH) model and hybrid model of Blann using the code Alice/91. The high energy part of the excitation functions are dominated by pre-equilibrium reaction mechanism whereas the low energy parts are dominated by equilibrium evaporation with its characteristic peak. The GDH model provides a potentially better description of the physical process (i.e. a higher probability for peripheral collisions to undergo precompound decay than for central collisions) compared to hybrid model. However in the energy range of present measurement most of the excitation functions are fitted reasonably well by both GDH model and hybrid model with initial exciton number N 0 =4 (N n =2, N p =2, N h =0). Barring a few reactions we have found the overall agreement between theory and experiment is reasonably good taking the limitations of the theory into account. (author)

  12. Measurement of isomeric yield ratios of 86m,gY and 87m,gY in the quasi-monoenergetic neutron induced reactions of 89Y

    Science.gov (United States)

    Nadeem, Muhammad; Zaman, Muhammad; Naik, Haladhara; Kim, Kwangsoo; Kim, Guinyun

    2018-02-01

    The isomeric yield ratios (IR) of 86m,gY and 87m,gY were measured in the 23 to 37 MeV quasi-monoenergetic neutron induced reaction of 89Y by using an off-line γ-ray spectrometric technique. The IR values in the 89Y(n , xn) reactions were also calculated using the TALYS 1.8 code and found to be in good agreement for 87m,gY but slightly less for 86m,gY. The IR values of 86m,gY and 87m,gY from the present work in the 89Y(n , xn) reactions were compared with the literature data in the 89Y(γ , xn), 89Y(p , x) and 89Y(α , x) reactions. It was found that the IR values of 86m,gY and 87m,gY in all these reactions increase with excitation energy. At the same excitation energy, the IR values are higher in the alpha induced reaction than in the proton, neutron and photon induced reactions due to higher input angular momentum in the former than in the later. These two observations indicate the role of entrance parameters. However, it is surprising to see that at the same excitation energy, the IR values of 86m,gY and 87m,gY in the 89Y(n , xn) reaction are nearly constant and significantly higher than in the 89Y(γ , xn) reaction.

  13. Integral measurement of the {sup 12}C(n, p){sup 12}B reaction up to 10 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Zugec, P.; Bosnar, D. [University of Zagreb, Department of Physics, Faculty of Science, Zagreb (Croatia); Colonna, N.; Barbagallo, M.; Mastromarco, M.; Tagliente, G.; Variale, V. [Istituto Nazionale di Fisica Nucleare, Bari (Italy); Ventura, A. [Istituto Nazionale di Fisica Nucleare, Bologna (Italy); Mengoni, A. [ENEA, Bologna (Italy); Altstadt, S.; Langer, C.; Lederer, C.; Reifarth, R.; Schmidt, S.; Weigand, M. [Johann-Wolfgang-Goethe Universitaet, Frankfurt (Germany); Andrzejewski, J.; Marganiec, J.; Perkowski, J. [Uniwersytet Lodzki, Lodz (Poland); Audouin, L.; Leong, L.S.; Tassan-Got, L. [Centre National de la Recherche Scientifique/IN2P3 - IPN, Orsay (France); Becares, V.; Cano-Ott, D.; Garcia, A.R.; Gonzalez-Romero, E.; Martinez, T.; Mendoza, E. [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain); Becvar, F.; Krticka, M.; Kroll, J.; Valenta, S. [Charles University, Prague (Czech Republic); Belloni, F.; Mondalaers, W.; Plompen, A.; Schillebeeckx, P. [European Commission JRC, Institute for Reference Materials and Measurements, Geel (Belgium); Berthoumieux, E.; Fraval, K.; Gunsing, F. [CEA/Saclay - IRFU, Gif-sur-Yvette (France); Billowes, J.; Ware, T.; Wright, T. [University of Manchester, Manchester (United Kingdom); Boccone, V.; Brugger, M.; Calviani, M.; Cerutti, F.; Chiaveri, E.; Chin, M.; Ferrari, A.; Guerrero, C.; Losito, R.; Roman, F.; Rubbia, C.; Tsinganis, A.; Versaci, R.; Vlachoudis, V.; Weiss, C. [CERN, Geneva (Switzerland); Calvino, F.; Cortes, G.; Gomez-Hornillos, M.B.; Riego, A. [Universitat Politecnica de Catalunya, Barcelona (Spain); Carrapico, C.; Goncalves, I.F.; Sarmento, R.; Vaz, P. [Universidade de Lisboa, C2TN-Instituto Superior Tecnico, Lisboa (Portugal); Cortes-Giraldo, M.A.; Praena, J.; Quesada, J. [Universidad de Sevilla, Sevilla (Spain); Cosentino, L.; Finocchiaro, P. [INFN - Laboratori Nazionali del Sud, Catania (Italy); Diakaki, M.; Karadimos, D.; Kokkoris, M.; Vlastou, R. [National Technical University of Athens (NTUA), Athens (Greece); Domingo-Pardo, C.; Giubrone, G.; Tain, J.L. [CSIC-Universidad de Valencia, Instituto de Fisica Corpuscular, Valencia (Spain); Dressler, R.; Heinitz, S.; Kivel, N.; Schumann, D. [Paul Scherrer Institut, Villigen (Switzerland); Duran, I.; Tarrio, D. [Universidade de Santiago de Compostela, Santiago de Compostela (Spain); Eleftheriadis, C.; Manousos, A. [Aristotle University of Thessaloniki, Thessaloniki (Greece); Ganesan, S.; Gurusamy, P.; Saxena, A. [Bhabha Atomic Research Centre (BARC), Mumbai (India); Griesmayer, E.; Jericha, E.; Leeb, H. [Atominstitut der Oesterreichischen Universitaeten, Technische Universitaet Wien, Wien (Austria); Jenkins, D.G.; Vermeulen, M.J. [University of York, York, Heslington (United Kingdom); Kaeppeler, F. [Karlsruhe Institute of Technology (KIT), Institut fuer Kernphysik, Karlsruhe (Germany); Lo Meo, S. [Istituto Nazionale di Fisica Nucleare, Bologna (Italy); ENEA, Bologna (Italy); Massimi, C.; Mingrone, F.; Vannini, G. [Dipartimento di Fisica, Universita di Bologna (IT); INFN, Bologna (IT); Mastinu, P. [Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Legnaro (IT); Milazzo, P.M. [Istituto Nazionale di Fisica Nucleare, Trieste (IT); Mirea, M. [Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH, Magurele (RO); Musumarra, A. [Universita di Catania, Dipartimento di Fisica e Astronomia DFA, Catania (IT); INFN-Laboratori Nazionali del Sud, Catania (IT); Paradela, C. [European Commission JRC, Institute for Reference Materials and Measurements, Geel (BE); Universidade de Santiago de Compostela, Santiago de Compostela (ES); Pavlik, A. [Faculty of Physics, University of Vienna, Wien (AT); Rauscher, T. [University of Hertfordshire, Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, Hatfield (GB); University of Basel, Department of Physics, Basel (CH); Wallner, A. [Faculty of Physics, University of Vienna, Wien (AT); Australian National University, Research School of Physics and Engineering, Canberra (AU)

    2016-04-15

    The integral measurement of the {sup 12}C(n, p){sup 12}B reaction was performed at the neutron time-of-flight facility nTOF at CERN. The total number of {sup 12}B nuclei produced per neutron pulse of the nTOF beam was determined using the activation technique in combination with a time-of-flight technique. The cross section is integrated over the nTOF neutron energy spectrum from reaction threshold at 13.6 MeV to 10 GeV. Having been measured up to 1GeV on basis of the {sup 235}U(n, f) reaction, the neutron energy spectrum above 200 MeV has been re-evaluated due to the recent extension of the cross section reference for this particular reaction, which is otherwise considered a standard up to 200 MeV. The results from the dedicated GEANT4 simulations have been used to evaluate the neutron flux from 1 GeV up to 10 GeV. The experimental results related to the {sup 12}C(n, p){sup 12}B reaction are compared with the evaluated cross sections from major libraries and with the predictions of different GEANT4 models, which mostly underestimate the {sup 12}B production. On the contrary, a good reproduction of the integral cross section derived from measurements is obtained with TALYS-1.6 calculations, with optimized parameters. (orig.)

  14. Measurement of (n, p) reaction cross sections for short-lived products (T1/2=0.6-13.8 s) by 14 MeV neutrons

    International Nuclear Information System (INIS)

    Kasugai, Yoshimi; Ikeda, Yujiro; Takeuchi, Hiroshi

    2001-01-01

    Activation cross sections of the (n, p) reactions at 14 MeV for short-lived products were measured by using the D-T neutrons source, FNS (Fusion Neutronics Source) at JAERI. Measured reactions were 11 B(n, p) 11 Be(T 1/2 =13.8 s), 18 O(n, p) 18 N(0.63 s), 26 Mg(n, p) 26 Na(1.07 s), 30 Si(n, p) 30 Al(3.60 s) and 34 S(n, p) 34 S(12.4 s). Using the present results, systematic trend of the (n, p) reaction cross sections for light-mass-targets was discussed. (author)

  15. The cross-section of the 10B(n,α)7Li reaction measured in the MeV energy range

    International Nuclear Information System (INIS)

    Giorginis, Georgios; Khryachkov, Vitali

    2006-01-01

    The excitation function of the 10 B(n,α) 7 Li reaction was measured between 1.5 and 5.6 MeV within the frame of the IAEA Coordinated Research Project (CRP) on 'Improvement of the Standard Cross Sections for Light Elements'. An ionisation chamber and signal digitisation were used for the spectrometry of the reaction products, which were forwards emitted by bombarding a thin boron target with neutrons produced at the IRMM Van de Graaff accelerator. The neutron flux was determined by measuring the backwards emitted fission fragments from a 238 U sample mounted in a back-to-back geometry relative to the boron target. The highlight of this study was the discovery of the kinematic effect of particle leaking, which is very important for the accurate determination of the number of the boron reaction events. The experiment is described and the results are discussed and compared with evaluations and experimental data of other groups

  16. [Adverse reactions to insulin].

    Science.gov (United States)

    Liñana, J J; Montoro, F J; Hernández, M D; Basomba, A

    1997-07-01

    The prevalence of allergic reactions to insuline has decreased during the last few years. Probably this is due to the use of the newly-developed recombinant human insuline. At present, adverse reactions to insuline occur in 5-10% of patients on therapy with insuline. Adverse reactions may be local (more frequent) or systemic (rare). Insuline resistance consists in a different type of immunological reaction. Diagnosis of allergy to insuline is based on clinical history and cutaneous and serological tests. Treatment depends upon the severity of the reaction. When insuline is indispensable despite a previous allergic reaction, a desensitization protocol may be implemented.

  17. Measurement of cross sections for alpha-induced reactions on 197Auand thick-target yields for the (alpha,gamma) process on 64Zn and63Cu

    Energy Technology Data Exchange (ETDEWEB)

    Basunia, M.S.; Shugart, H.A.; Smith, A.R.; Norman, E.B.

    2006-08-07

    We have measured the cross sections for the197Au(alpha,gamma)201Tl and 197Au(alpha,2n)199Tl reactions in the 17.9-to 23.9-MeV energy range, and 197Au(alpha,n)200Tl reaction in the 13.4-to 23.9-MeV energy range using an activation technique. Thick-targetyields for the 64Zn(alpha,gamma)68Ge (7- to 14-MeV) and63Cu(alpha,gamma)67Ga (7-MeV) reactions were measured. For allmeasurements, natural elements were bombarded with He+ beams from the88-inch Cyclotron at the Lawrence Berkeley National Laboratory (LBNL).Irradiated samples were counted using a gamma-spectrometry system at LBNLs Low Background Facility. Measured 197Au(alpha,gamma)201Tlcross-sections were compared with the NON-SMOKER theoretical values. Thethick-target yields for the 64Zn(alpha,gamma)68Ge and63Cu(alpha,gamma)67Ga reactions are also compared with the theoreticalyield, calculated numerically using the energy dependent NON-SMOKER crosssection data. In both cases, measured values are found to follow a trendof overlapping the predicted value near the alpha nucleus barrier heightand fall below with a slowly widening difference between them in the subbarrier energy points.

  18. Measurements of the proton total reaction cross section for 24Mg, 646668Zn and 140Ce between 17.5 and 48 MeV

    International Nuclear Information System (INIS)

    Davison, N.E.; Hasell, D.K.; Sourkes, A.M.; Oers, W.T.H. van

    1977-01-01

    Measurements of proton total reaction cross sections have been made for the deformed nuclei 24 Mg, 64 66 68 Zn and 140 Ce in the energy range 17.5 to 48 MeV using an attenuation technique. The cross sections are compared with various theoretical predictions and with existing data. (Auth.)

  19. Measurement of the thermal neutron capture cross section and the resonance integral of the {sup 109}Ag(n,{gamma}){sup 110m}Ag reaction

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, S.; Wada, H.; Furutaka, K.; Harada, H.; Katoh, T. [Japan Nuclear Cycle Development Inst., Tokai Works, Tokai, Ibaraki (Japan)

    2001-03-01

    The thermal neutron capture cross section ({sigma}{sub 0}) and the resonance integral (I{sub 0}) of the {sup 109}Ag(n,{gamma}) reaction were measured by the activation and {gamma}-ray spectroscopic methods to develop a neutron flux monitor for the long irradiation. (author)

  20. Measurement of the thermal neutron capture cross section and the resonance integral of the 109Ag(n,γ)110mAg reaction

    International Nuclear Information System (INIS)

    Nakamura, S.; Wada, H.; Furutaka, K.; Harada, H.; Katoh, T.

    2001-01-01

    The thermal neutron capture cross section (σ 0 ) and the resonance integral (I 0 ) of the 109 Ag(n,γ) reaction were measured by the activation and γ-ray spectroscopic methods to develop a neutron flux monitor for the long irradiation. (author)

  1. Measurement of glass transition temperature, residual heat of reaction and mixing ratio of epoxy resins using near infrared spectroscopy: a preliminary study

    DEFF Research Database (Denmark)

    Houmøller, Lars Plejdrup; Laursen, Peter Clemen

    2003-01-01

    As a measure of the degree of curing of epoxy resins, the glass transition temperature, Tg, and the residual heat of reaction, DeltaHr, are often used. In this study, near infrared spectroscopy and multivariate calibration (partial least squares regression (PLSR)) have been used to monitor the two...

  2. Measuring Heterogeneous Reaction Rates with ATR-FTIR Spectroscopy to Evaluate Chemical Fates in an Atmospheric Environment: A Physical Chemistry and Environmental Chemistry Laboratory Experiment

    Science.gov (United States)

    Roberts, Jason E.; Zeng, Guang; Maron, Marta K.; Mach, Mindy; Dwebi, Iman; Liu, Yong

    2016-01-01

    This paper reports an undergraduate laboratory experiment to measure heterogeneous liquid/gas reaction kinetics (ozone-oleic acid and ozone-phenothrin) using a flow reactor coupled to an attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrometer. The experiment is specially designed for an upper-level undergraduate Physical…

  3. Microfluidic technology platforms for synthesizing, labeling and measuring the kinetics of transport and biochemical reactions for developing molecular imaging probes

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, Michael E. [Univ. of California, Los Angeles, CA (United States)

    2009-09-01

    Radiotracer techniques are used in environmental sciences, geology, biology and medicine. Radiotracers with Positron Emission Tomography (PET) provided biological examinations of ~3 million patients 2008. Despite the success of positron labeled tracers in many sciences, there is limited access in an affordable and convenient manner to develop and use new tracers. Integrated microfluidic chips are a new technology well matched to the concentrations of tracers. Our goal is to develop microfluidic chips and new synthesis approaches to enable wide dissemination of diverse types of tracers at low cost, and to produce new generations of radiochemists for which there are many unfilled jobs. The program objectives are to: 1. Develop an integrated microfluidic platform technology for synthesizing and 18F-labeling diverse arrays of different classes of molecules. 2. Incorporate microfluidic chips into small PC controlled devices (“Synthesizer”) with a platform interfaced to PC for electronic and fluid input/out control. 3. Establish a de-centralized model with Synthesizers for discovering and producing molecular imaging probes, only requiring delivery of inexpensive [18F]fluoride ion from commercial PET radiopharmacies vs the centralized approach of cyclotron facilities synthesizing and shipping a few different types of 18F-probes. 4. Develop a position sensitive avalanche photo diode (PSAPD) camera for beta particles embedded in a microfluidic chip for imaging and measuring transport and biochemical reaction rates to valid new 18F-labeled probes in an array of cell cultures. These objectives are met within a research and educational program integrating radio-chemistry, synthetic chemistry, biochemistry, engineering and biology in the Crump Institute for Molecular Imaging. The Radiochemistry Training Program exposes PhD and post doctoral students to molecular imaging in vitro in cells and microorganisms in microfluidic chips and in vivo with PET, from new technologies

  4. Measurement of the reaction e+e- → η π + π - in the center of mass energy interval 1350-2400 MeV

    International Nuclear Information System (INIS)

    1988-05-01

    The e + e - → η π + π - reaction has been measured in the center of mass energy interval 1350-2400 MeV by the magnetic detector DM2 at the Orsay storage ring DCI. Under the hypothesis of only one large resonance the cross section is not fit in a satisfactory way. The branching ratio τ - → η π - π 0 ν τ = (0.13 ± 0.02)% is deduced via CVC from the above measurement

  5. A high-resolution measurement of the 12C(γ,p) 11B reaction to excited states for Eγ = 50-70 MeV

    International Nuclear Information System (INIS)

    Kuzin, A.; Rassool, R.P.; Thompson, M.N.; Adler, J.-O.; Fissum, K.; Hansen, K.; Isaksson, L.; Lundin, M.; Ruijter, H.; Schroeder, B.; Annand, J.R.M.; Crawford, G.I.; McGeorge, J.C.; Gregel, J.; Ryckebusch, J.

    1998-01-01

    Relative population of states in 11 B following the 12 C(γ,p) reaction was measured with high resolution using the de-excitation x-ray technique. Population of the states near 7 MeV in 11 B are clearly resolved and the measured population clarifies earlier conflicting data. Comparison of the results with new Random Phase Approximation (RPA) calculations indicates the importance of both one- and multi-nucleon processes. (authors)

  6. Evaluation of the extent of initial Maillard reaction during cooking some vegetables by direct measurement of the Amadori compounds.

    Science.gov (United States)

    Yu, Jiahao; Zhang, Shuqin; Zhang, Lianfu

    2018-01-01

    During vegetable cooking, one of the most notable and common chemical reactions is the Maillard reaction, which occurs as a result of thermal treatment and dehydration. Amadori compound determination provides a very sensitive indicator for early detection of quality changes caused by the Maillard reaction, as well as to retrospectively assess the heat treatment or storage conditions to which the product has been subjected. In this paper, a hydrophilic interaction liquid chromatographic-electrospray ionization-tandem mass spectrometric method was developed for the analysis of eight Amadori compounds, and the initial steps of the Maillard reaction during cooking (steaming, frying and baking) bell pepper, red pepper, yellow onion, purple onion, tomato and carrot were also assessed by quantitative determination of these Amadori compounds. These culinary treatments reduced moisture and increased the total content of Amadori compounds, which was not dependent on the type of vegetable or cooking method. Moreover, the effect of steaming on Amadori compound content and water loss was less than that by baking and frying vegetables. Further studies showed that the combination of high temperature and short time may lead to lower formation of Amadori compounds when baking vegetables. Culinary methods differently affected the extent of initial Maillard reaction when vegetables were made into home-cooked products. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  7. Measurement of double differential charged-particle emission cross sections for reactions induced by 26 MeV protons and FKK model analysis

    International Nuclear Information System (INIS)

    Watanabe, Y.; Aoto, A.; Kashimoto, H.

    1994-01-01

    Double differential charged-particle emission cross sections of proton-induced reactions have been measured for nat C, 27 Al, nat Si, 98 Mo, 106 Pd, 159 Tb and 181 Ta at energies around 26 MeV. Several (p,p') and (p,n) data for 98 Mo and 106 Pd in the incident energy range from 12 to 26 MeV are analysed in terms of the Feshbach-Kerman-Koonin model, in order to study preequilibrium nucleon emission from nucleon-induced reactions

  8. Neutrino test of muon number conservation and a measurement of the reaction ν/sub e/ + D → p + e- + p

    International Nuclear Information System (INIS)

    Nemethy, P.; Willis, S.E.; Hughes, V.

    1979-01-01

    To test whether lepton conservation proceeds via a multiplicative law a search was made for the wrong neutrinos (anti ν/sub e/) from μ + decay. A six-ton H 2 O Cerenkov detector was used to look for the reaction anti ν/sub e/p → e + n at the LAMPF beam stop. A preliminary limit, R = anti ν/sub e//all μ + decay 2 O, the cross-section for the reaction anti ν/sub e/+D→p+e - +p was measured and found to be 1.17 +- .32 times the expected value

  9. Measurements and systematics studies of the (n,p), (n,α) and (n,2n) reactions cross-sections at 14.5 MeV neutrons

    International Nuclear Information System (INIS)

    Osman, Khalda

    2000-01-01

    Accurate knowledge of the cross-sections for fast neutron-induced reactions utilizing the D-T reaction is important not only because of the wide spread of data observed in the literature, but also because of the world wide demand and requests for such data, in view of the increasing interest in the fusion reactor technology, which is based on the same reactions. Cross-sections are needed also for various practical purposes, including neutron activation analysis and dosimetry. In this work the (n.p), (n,2n) and (n,α) reactions cross-sections were measured at 14.5 MeV for isotopes of the elements: Cr, Ti, Ni, Co, Zr, and Mo using the activation method. The measured cross-sections were compared with recently published data. Good agreement was observed for most of the measurements. The discrepancies observed were attributed to difficulties related to the long half-life of the product nuclei and small abundances of the target isotopes. Attempts were also made to study the dependence of the (n,p), (n,2n) and (n,α) reactions cross-sections on the on the asymmetry parameter (N-Z)/A. The results confirmed the trend theoretically suggested by Levkovskii and experimentally realized by Qaim and co-workers. The isotopic dependence of (n,p) reaction cross-sections and the variation of the ration σ n ,p/σ n ,α with Z-number of the target isotopes were also studied in this work and the results obtained were found to be in agreement with theoretical predictions. In this work studies carried out for the systematics of the (n,p), (n,2n) and (n,α) reactions cross-sections at 14 MeV neutrons and formula based on the statistical model presented, with the aim of improving the systematics of these cross-sections. Comparison of present proposed systematics were for the (n,p), (n,2n) and (n,α) reactions cross-sections with the cross-section values measured in this work was made. Good agreement was generally noted, but some discrepancies were also observed. These discrepancies were

  10. Lowest Q2 Measurement of the γ*p→ Δ Reaction: Probing the Pionic Contribution

    Energy Technology Data Exchange (ETDEWEB)

    Stave, Sean C. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2006-06-01

    The first excited state of the proton, the Delat, can be reached through a magnetic dipole spin flip of one of the quarks (M1) or through electric and Coulomb quadrupole terms (E2 and C2) which indicate a deviation from spherical symmetry. The quark models using the color hyperfine interaction underestimate the size of the quadrupole terms by more than an order of magnitude. Models using the pion cloud do a much better job of describing the data. This is expected due to the spontaneous breaking of chiral symmetry which leads to a cloud of virtual p wave pions which introduce the non-spherical amplitudes. The data presented in this work fill gaps in the low Q², long distance region where the pion cloud is expected to dominate and to produce significant Q2 variation. The p(e¯, ép)π° reaction was measured in the Δ region at Q² = 0.060 (GeV/c)², the lowest Q² to date for pion electroproduction, utilizing out-of-plane magnetic spectrometers at the Mainz Microtron in Germany. This work reports results for the dominant transition magnetic dipole amplitude and the quadrupole to dipole ratios obtained from fitting the new data with models using a three parameter, resonant multipole fit: M³/²1+ = (40.33 +- 0.63stat+syst +-model)(10-³/mπ+), E2/M1=Re(E³/²1+M³/²1+) = (-2.28+- 0.29stat+syst +- 0.20model)%, and C2/M1 =Re(S³/²1+/M³/²1+) poles disagree with predictions of the quark models but are in reasonable agreement with a chiral extrapolation of lattice QCD, chiral effective field theory and dynamical model results confirming the dominance and general Q² variation of the long range pionic contribution. While there is qualitative agreement with the models, there is no quantitative agreement thus indicating the need for further improvement of the models.

  11. A Simple, Low-cost, and Robust System to Measure the Volume of Hydrogen Evolved by Chemical Reactions with Aqueous Solutions.

    Science.gov (United States)

    Brack, Paul; Dann, Sandie; Wijayantha, K G Upul; Adcock, Paul; Foster, Simon

    2016-08-17

    There is a growing research interest in the development of portable systems which can deliver hydrogen on-demand to proton exchange membrane (PEM) hydrogen fuel cells. Researchers seeking to develop such systems require a method of measuring the generated hydrogen. Herein, we describe a simple, low-cost, and robust method to measure the hydrogen generated from the reaction of solids with aqueous solutions. The reactions are conducted in a conventional one-necked round-bottomed flask placed in a temperature controlled water bath. The hydrogen generated from the reaction in the flask is channeled through tubing into a water-filled inverted measuring cylinder. The water displaced from the measuring cylinder by the incoming gas is diverted into a beaker on a balance. The balance is connected to a computer, and the change in the mass reading of the balance over time is recorded using data collection and spreadsheet software programs. The data can then be approximately corrected for water vapor using the method described herein, and parameters such as the total hydrogen yield, the hydrogen generation rate, and the induction period can also be deduced. The size of the measuring cylinder and the resolution of the balance can be changed to adapt the setup to different hydrogen volumes and flow rates.

  12. Direct measurement of Bisphenol A (BPA), BPA glucuronide and BPA sulfate in a diverse and low-income population of pregnant women reveals high exposure, with potential implications for previous exposure estimates: a cross-sectional study

    OpenAIRE

    Gerona, Roy R.; Pan, Janet; Zota, Ami R.; Schwartz, Jackie M.; Friesen, Matthew; Taylor, Julia A.; Hunt, Patricia A.; Woodruff, Tracey J.

    2016-01-01

    Background Bisphenol A (BPA) is a ubiquitous, endocrine-disrupting environmental contaminant that increases risk of some adverse developmental effects. Thus, it is important to characterize BPA levels, metabolic fate and sources of exposure in pregnant women. Methods We used an improved liquid chromatography-tandem mass spectrometry (LC-MS/MS) analytic method to directly and simultaneously measure unconjugated BPA (uBPA), BPA glucuronide and BPA sulfate in the urine of a population of ethnica...

  13. New Improved Indirect Measurement of the F-19(p, alpha)O-16 Reaction at Energies of Astrophysical Relevance

    Czech Academy of Sciences Publication Activity Database

    Indelicato, I.; La Cognata, M.; Spitaleri, C.; Burjan, Václav; Cherubini, S.; Gulino, M.; Hayakawa, S.; Hons, Zdeněk; Kroha, Václav; Lamia, L.; Mazzocco, M.; Mrázek, Jaromír; Pizzone, R. G.; Romano, S.; Strano, E.; Torresi, D.; Tumino, A.

    2017-01-01

    Roč. 845, č. 1 (2017), č. článku 19. ISSN 0004-637X Institutional support: RVO:61389005 Keywords : nuclear reactions * nucleosynthesis * abundances Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 5.533, year: 2016

  14. Measurement of the helicity-dependent total cross-section for the {gamma}n{yields} p {pi}{sup -}{pi}{sup 0} reaction

    Energy Technology Data Exchange (ETDEWEB)

    Ahrens, J.; Arends, H.J.; Beck, R.; Heid, E.; Jahn, O.; Lang, M.; Martinez-Fabregate, M.; Tamas, G.; Thomas, A. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Altieri, S.; Panzeri, A.; Pinelli, T. [INFN, Sezione di Pavia, Pavia (Italy); Universita di Pavia, Dipartimento di Fisica Nucleare e Teorica, Pavia (Italy); Annand, J.R.M.; McGeorge, J.C.; Protopopescu, D.; Rosner, G. [University of Glasgow, SUPA, School of Physics and Astronomy, Glasgow (United Kingdom); Blackston, M.A.; Weller, H.R. [Duke University, Department of Physics, Durham, NC (United States); Bradtke, C.; Dutz, H.; Klein, F.; Rohlof, C. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Braghieri, A.; Pedroni, P. [INFN, Sezione di Pavia, Pavia (Italy); Hose, N. d' [DSM/DAPNIA/SPhN, CEA Saclay, Gif-sur-Yvette Cedex (France); Fix, A. [Tomsk Polytechnic University, Laboratory of Mathematical Physics, Tomsk (Russian Federation); Kondratiev, R.; Lisin, V. [Academy of Science, INR, Moscow (Russian Federation); Meyer, W.; Reicherz, G. [Ruhr-Universitaet Bochum, Insitut fuer Experimentalphysik, Bochum (Germany); Rostomyan, T. [Universiteit Gent, Subatomaire en Stralingsfysica, Gent (Belgium); INFN, Sezione di Pavia, Pavia (Italy); Ryckbosch, D. [Universiteit Gent, Subatomaire en Stralingsfysica, Gent (Belgium)

    2011-03-15

    The helicity dependence of the total cross-section for the {gamma}n{yields}p{pi}{sup -}{pi}{sup 0} reaction has been measured for the first time at incident photon energies from 450 to 800MeV. The measurement was performed with the large-acceptance detector DAPHNE at the tagged photon beam facility of the MAMI accelerator in Mainz. Both the measured unpolarized and the helicity-dependent observables are not well described by the existing theoretical models. (orig.)

  15. Measurement of excitation functions for natPb( p, xn)199,200,201Pb reactions with stacked foil activation technique at KOMAC

    Science.gov (United States)

    Lee, Jieun; Yoon, Jungran; Ro, Taeik; Lee, Samyol

    2018-01-01

    The excitation functions of natPb( p, xn)199,200,201Pb reactions within the proton energy of 71.5 - 91.7 MeV were measured by using the 100-MeV linear accelerator at the Korea Multi-Purpose Accelerator Complex (KOMAC). The stacked foil activation and off-line gamma-ray spectrometric technique was used in the present study. The 27Al( p, 3 p + n)24Na monitor reaction was used to estimate the proton flux. The excitation functions of natPb( p, xn)199,200,201Pb reactions were derived from the photo-peak activities of delayed γ-rays of the produced nuclei. The present results have been compared with the literature data and the theoretical values from TENDL-2015 library. The natPb( p, xn)199,201Pb reaction cross-sections at the proton energy of 91.7 MeV has been measured for the first time, whereas for the proton energies of 71.5 - 84.5 MeV are in general agreement with the literature data within limits of uncertainty. Overall, the experimental data from the present work and literature show increase trend with proton energy similar to the theoretical values of TENDL-2015 library with some systematic differences.

  16. A new method for measuring reaction times for odour detection at iso-intensity: Comparison between an unpleasant and pleasant odour.

    Science.gov (United States)

    Jacob, Tim J C; Wang, Liwei

    2006-03-30

    A psychophysical detection test was developed to measure the reaction time of human subjects to a pleasant and an unpleasant odour. The response latencies to stimulation with a malodour (valeric acid) and pleasant odorant (amyl acetate) were compared over a range of different stimulus strengths. By expressing reaction time as a function of detection rate, the responses to the two odours can be compared at iso-intensity across the concentration range. This is the first study that allows odorants to be compared at the same intensity over a range of concentrations. The malodour valeric acid was detected more rapidly than amyl acetate; at the 50% detection level the reaction time for the detection of amyl acetate was 1.74 s compared 1.36 s for valeric acid (380 ms or 22% faster). Women were significantly faster than men at detecting both the unpleasant (by 18%) and pleasant (by 26%) odour at the 50% detection level and this disparity increased with decreasing stimulus strength. In conclusion, we demonstrate the ability of a new method for the measurement of reaction times to odour detection to discriminate between two different odours - a malodour and a non-malodour.

  17. High-accuracy measurements of OH reaction rate constants and IR absorption spectra: CH2=CF-CF3 and trans-CHF=CH-CF3.

    Science.gov (United States)

    Orkin, Vladimir L; Martynova, Larissa E; Ilichev, Alexander N

    2010-05-20

    Rate constants for the gas phase reactions of OH radicals with two isomers of tetrafluoropropene, CH(2)=CF-CF(3) (k(1)) and trans-CHF=CH-CF(3) (k(2)); were measured using a flash photolysis resonance-fluorescence technique over the temperature range 220 to 370 K. The Arrhenius plots were found to exhibit a noticeable curvature. The temperature dependences of the rate constants are very weak and can be represented by the following expressions over the indicated temperature intervals: k(1)(220-298 K) = 1.145 x 10(-12) x exp{13/T} cm(3) molecule(-1) s(-1), k(1)(298-370 K) = 4.06 x 10(-13) x (T/298)(1.17) x exp{+296/T} cm(3) molecule(-1) s(-1), k(2)(220-370 K) = 1.115 x 10(-13) x (T/298)(2.03) x exp{+522/T} cm(3) molecule(-1) s(-1). The overall accuracy of the rate constant measurements is estimated to be ca. 2% to 2.5% at the 95% confidence level. The uncertainty of the measured reaction rate constants is discussed in detail. The atmospheric lifetimes due to reactions with tropospheric OH were estimated to be 12 and 19 days respectively under the assumption of a well mixed atmosphere. IR absorption cross-sections were measured for both compounds and their global warming potentials were estimated.

  18. Storage ion trap of an 'In-Flight Capture' type for precise mass measurement of radioactive nuclear reaction products and fission fragments

    International Nuclear Information System (INIS)

    Tarantin, N.I.

    2001-01-01

    Data on nuclear masses provide a basis for creating and testing various nuclear models. A tandem system of FLNR comprised of the U-400M cyclotron, the COMBAS magnetic separator and the mass-spectrometric ion trap of an 'in-flight capture' type is considered as a possible complex for producing of the short-lived nuclei in fragmentation reactions by heavy ions and for precise mass measurement of these nuclei. The plan of scientific and technical FLNR research includes a project DRIBs for producing beams of accelerated radioactive nuclear reaction products and photofission fragments. This project proposes also precise mass measurements of the fission fragment with the help of the ion trap. The in-flight entrance of the ions and their capture in the mass-spectrometric ion trap using the monochromatizing degrader, the static electric and magnetic fields and a new invention, a magnetic unidirectional transporting ventil, is considered

  19. Solving the Large Discrepancy Between Inclusive and Exclusive Measurements of the 8Li + 4He → 11B + n Reaction Cross Section at Astrophysical Energies

    Science.gov (United States)

    La Cognata, M.; Del Zoppo, A.; Alba, R.; Cherubini, S.; Colonna, N.; Di Pietro, A.; Figuera, P.; Gulino, M.; Lamia, L.; Musumarra, A.; Pellegriti, M. G.; Pizzone, R. G.; Rolfs, C.; Romano, S.; Spitaleri, C.; Tumino, A.

    2009-12-01

    A solution of the large discrepancy existing between inclusive and exclusive measurements of the 8Li + 4He → 11B + n reaction cross section at E cm < 3 MeV is evaluated. This problem has profound astrophysical relevance for this reaction is of great interest in big bang and r-process nucleosynthesis. By means of a novel technique, a comprehensive study of all existing 8Li + 4He → 11B + n cross section data is carried out, setting up a consistent picture in which all the inclusive measurements provide the reliable value of the cross section. New unambiguous signatures of the strong branch pattern non-uniformities, near the threshold of higher 11B excited levels, are presented and their possible origin, in terms of the cluster structure of the involved excited states of 11B and 12Bnuclei, is discussed.

  20. Experimental setup and procedure for the measurement of the 7Be(n,p)7Li reaction at n_TOF

    Science.gov (United States)

    Barbagallo, M.; Andrzejewski, J.; Mastromarco, M.; Perkowski, J.; Damone, L. A.; Gawlik, A.; Cosentino, L.; Finocchiaro, P.; Maugeri, E. A.; Mazzone, A.; Dressler, R.; Heinitz, S.; Kivel, N.; Schumann, D.; Colonna, N.; Aberle, O.; Amaducci, S.; Audouin, L.; Bacak, M.; Balibrea, J.; Bečvář, F.; Bellia, G.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brown, A.; Caamaño, M.; Calviño, F.; Calviani, M.; Cano-Ott, D.; Cardella, R.; Casanovas, A.; Cerutti, F.; Chen, Y. H.; Chiaveri, E.; Cortés, G.; Cortés-Giraldo, M. A.; Cristallo, S.; Diakaki, M.; Dietz, M.; Domingo-Pardo, C.; Dupont, E.; Durán, I.; Fernández-Domínguez, B.; Ferrari, A.; Ferreira, P.; Furman, V.; Göbel, K.; García, A. R.; Gilardoni, S.; Glodariu, T.; Gonçalves, I. F.; González-Romero, E.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Harada, H.; Heyse, J.; Jenkins, D. G.; Jericha, E.; Johnston, K.; Käppeler, F.; Kadi, Y.; Kalamara, A.; Kavrigin, P.; Kimura, A.; Kokkoris, M.; Krtička, M.; Kurtulgil, D.; Leal-Cidoncha, E.; Lederer, C.; Leeb, H.; Lerendegui-Marco, J.; Lo Meo, S.; Lonsdale, S. J.; Macina, D.; Manna, A.; Marganiec, J.; Martínez, T.; Martins-Correia, J. G.; Masi, A.; Massimi, C.; Mastinu, P.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Musumarra, A.; Negret, A.; Nolte, R.; Oprea, A.; Pappalardo, A. D.; Patronis, N.; Pavlik, A.; Piscopo, M.; Porras, I.; Praena, J.; Quesada, J. M.; Radeck, D.; Rauscher, T.; Reifarth, R.; Robles, M. S.; Rubbia, C.; Ryan, J. A.; Sabaté-Gilarte, M.; Saxena, A.; Schell, J.; Schillebeeckx, P.; Sedyshev, P.; Smith, A. G.; Sosnin, N. V.; Stamatopoulos, A.; Tagliente, G.; Tain, J. L.; Tarifeño-Saldivia, A.; Tassan-Got, L.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Warren, S.; Weiss, C.; Woods, P. J.; Wright, T.; Žugec, P.

    2018-04-01

    Following the completion of the second neutron beam line and the related experimental area (EAR2) at the n_TOF spallation neutron source at CERN, several experiments were planned and performed. The high instantaneous neutron flux available in EAR2 allows to investigate neutron induced reactions with charged particles in the exit channel even employing targets made out of small amounts of short-lived radioactive isotopes. After the successful measurement of the 7Be(n, α) α cross section, the 7Be(n,p)7Li reaction was studied in order to provide still missing cross section data of relevance for Big Bang Nucleosynthesis (BBN), in an attempt to find a solution to the cosmological Lithium abundance problem. This paper describes the experimental setup employed in such a measurement and its characterization.

  1. Cross Sections for the Reactions e+e to K+ K- pi+pi-, K+ K- pi0pi0, and K+ K- K+ K- Measured Using Initial-State Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; /INFN, Trieste /Trieste U.; Milanes, D.A.; /INFN, Trieste /Trieste U.; Palano, A.; /INFN, Trieste /Trieste U.; Pappagallo, M.; /INFN, Trieste /Trieste U. /INFN, Bari /Bari U. /Bari U. /INFN, Bari; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum; Asgeirsson, D.J.; /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Trieste /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Ferrara /Ferrara U. /Frascati /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U., Comp. Sci. Dept. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Trieste /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Perugia /Perugia U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Pisa /Princeton U. /INFN, Trieste /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /INFN, Trieste /INFN, Trieste /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2011-08-19

    We study the processes e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}-{gamma}, K{sup +}K{sup -}{pi}{sup 0}{pi}{sup 0}{gamma}, and K{sup +}K{sup -}K{sup +}K{sup -}{gamma}, where the photon is radiated from the initial state. About 84000, 8000, and 4200 fully reconstructed events, respectively, are selected from 454 fb{sup -1} of BABAR data. The invariant mass of the hadronic final state defines the e{sup +}e{sup -} center-of-mass energy, so that the K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{gamma} data can be compared with direct measurements of the e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -} reaction. No direct measurements exist for the e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup 0}{pi}{sup 0} or e{sup +}e{sup -} {yields} K{sup +}K{sup -}K{sup +}K{sup -} reactions, and we present an update of our previous result with doubled statistics. Studying the structure of these events, we find contributions from a number of intermediate states, and extract their cross sections. In particular, we perform a more detailed study of the e{sup +}e{sup -} {yields} {phi}(1020){pi}{pi}{gamma} reaction, and confirm the presence of the Y (2175) resonance in the {phi}(1020)f{sub 0}(980) and K{sup +}K{sup -} f{sub 0}(980) modes. In the charmonium region, we observe the J/{psi} in all three final states and in several intermediate states, as well as the {phi}(2S) in some modes, and measure the corresponding branching fractions.

  2. Measurements of nitrogen depth distribution in the surface of steel with the 14N(d,p0)15N reaction

    International Nuclear Information System (INIS)

    Didriksson, R.; Goenczi, L.; Sundqvist, B.

    1980-01-01

    The 14 N(d,p 0 ) 15 N nuclear reaction has been used to measure the nitrogen depth distribution in the surface of steel samples. With a beam energy of 2.5 MeV a depth of 15μm could be analyzed. The depth resolution was 0.7 μm (FWHM) and nitrogen contents down to 0.02 percent could be determined. (author)

  3. Measurement of Analyzing Powers for the Reaction \\vec{p}+CH_2 at p_p = 1.75-5.3 GeV/c

    CERN Document Server

    Azhgirey, L S; Basilev, S N; Bushuev, Yu P; Glagolev, V V; Kirillov, D A; Korovin, P P; Manyakov, P K; Piskunov, N M; Sitnik, I M; Slepnev, V M; Muvsinsky, J; Tomasi-Gustafsson, E; Pentchev, L; Perdrisat, C F; Punjabi, V; Jones, M K; Kumbartzki, G F; Atanasov, I

    2004-01-01

    We report a new measurement of analyzing powers for the reaction \\vec{p}+CH_2\\to one charged particle+X at proton momenta of 1.75, 3.8, 4.5 and 5.3 GeV/c. These results extend the existing data basis, necessary for proton polarimetry at intermediate energy, and confirm the feasibility of a large acceptance polarimeter based on this process.

  4. Large scale collective modeling the final 'freeze out' stages of energetic heavy ion reactions and calculation of single particle measurables from these models

    International Nuclear Information System (INIS)

    Nyiri, Agnes

    2005-01-01

    -relativistic heavy ion reactions is an important hadronic observable sensitive to the early stages of system evolution. The flow analysis involves the particles, which have already been frozen out. Therefore, to perform realistic flow computations from the Multi Module Model we need a complete freeze out description and a well identified freeze out surface. However, the freeze out module is still not ready. Although we have not yet been able to evaluate collective flow using the Multi Module Model, the method and code for the calculation of flow components has been worked out in an independent module. This module is completed and can be coupled to the previous modules when those are ready for use. In order to test the code, we have calculated directed and elliptic flow from a tilted, ellipsoidally expanding source using a simple, blast wave type of model. This model was developed directly for this aim based on Buda-Lund hydro models. Although, this oversimplified blast wave model is not suitable to reproduce the experimental data -which will be an important task in the future to check our Multi Module Model-, it has provided us with important information. We have found that the directed flow, is very sensitive to the correct identification of the reaction plane included the determination of the impact parameter vector, and can be misinterpreted by some experimental methods. We have shown that misidentification of the reaction plane may even set the directed flow to zero by construction. We have presented results of the rapidity dependence of the directed flow, v1, and elliptic flow, v2, furthermore, the transverse momentum dependence of v2. We have also investigated the dependence of the flow pattern on the initial geometry of the fireball by calculating flow components from two ellipsoidal sources with the same thermodynamical properties but different shape. The code determining the freeze out hypersurface should still be improved in order to avoid inaccuracies in the further

  5. Measurement of isotopic cross sections of the fission fragments produced in 500 AMeV {sup 208}Pb + p reaction; Etude de la production des fragments de fission issus de la reaction {sup 208}Pb + p a 500 AMeV

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Dominguez, B

    2003-03-01

    The aim of this work is the study of the fission fragments produced in the spallation reaction {sup 208}Pb + p at 500 AMeV. The fission fragments from Z=23 up to Z=59 have been detected and identified by using the inverse kinematics technique with the high-resolution spectrometer FRS. The production cross sections and the recoil velocities of 430 nuclei have been measured. The measured data have been compared with previous data. The isotopic distributions show a high precision. However, the absolute value of the fission cross section is higher than expected. From the experimental data the characteristics of the average fissioning system have been reconstructed (Z{sub fis}, A{sub fis}, E*{sub fis}). In addition, the number of post-fission neutrons emitted from the fission fragments, v{sub post}, has been determined by using a new method. The experimental data have been compared to the two-steps models describing the spallation reaction. The impact of the model parameters on the observables has been analysed and the reasons Leading to the observed differences between the codes are also presented. This analyse shows a good agreement with the INCL4+ABLA code. (author)

  6. Measurement of the Ir-191,193(n,2n)Ir-190,192 Reaction Cross Section Between 9.0 and 16.5 MeV

    Science.gov (United States)

    Wildenhain, Elizabeth; Finch, Sean; Tornow, Werner; Krishichayan, F.

    2017-09-01

    Iridium is one of the elements prioritized by Nonproliferation and Homeland Security agencies. In addition, Ir-192 is being used in various medical treatments. Improved data and corresponding evaluations of neutron-induced reactions on the iridium isotopes are required to meet the demands of several applications of societal interest. This study measured the cross section of the Ir-191,193(n, 2n)Ir-190,192 reactions at energies from 9.0 to 16.5 MeV using the activation technique. Natural Ir samples [Ir-191 37.3%, Ir-193 62.7%] were sandwiched between Au-197 monitor foils and irradiated with monoenergetic neutron beams at the tandem facility of the Triangle Universities Nuclear Laboratory (TUNL). Gamma rays from the irradiated samples were counted in TUNL's low background facility using high-efficient HPGe detectors. Measured cross-section data are compared to previous data and to predictions from nuclear data libraries (e.g. ENDF). Research at TUNL funded by the NSF.

  7. Cs-Ba separation using N 2O as a reactant gas in a Multiple Collector-Inductively Coupled Plasma Mass Spectrometer collision-reaction cell: Application to the measurements of Cs isotopes in spent nuclear fuel samples

    Science.gov (United States)

    Granet, M.; Nonell, A.; Favre, G.; Chartier, F.; Isnard, H.; Moureau, J.; Caussignac, C.; Tran, B.

    2008-11-01

    In the general frameworks of the nuclear fuel cycle and environmental research field, the Cs isotopic composition must be known with high precision and accuracy. The direct determination of Cs isotopes by mass spectrometry techniques is generally hampered by the presence of Ba isobaric interferences however. Here we present a new method which takes advantage of the collision-reaction cell based Multiple Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) and allows to analyse Cs isotopes in the presence of Ba without prior separation step. The addition of N 2O gas in the cell leads to an antagonistic behavior of Cs + and Ba + as the latter reacts with the gas to form BaO + and BaOH + products whereas Cs + remains unreactive. The efficiency of the method was demonstrated for an UOx sample by comparing the results obtained (1) from the measurements of pure Cs fractions and (2) from Fission Products fractions containing more than 30 ionisable elements in addition to Cs, Ba, and where U and Pu were previously removed by using ion exchange resin. An excellent agreement is achieved between each set of experiments with an external reproducibility always better than 0.5% (RSD, k = 2). This study confirms the strong potential of collision-reaction cell to measure Cs isotopes in presence of interfering Ba, precluding therefore former systematic chemical separations.

  8. Cs-Ba separation using N{sub 2}O as a reactant gas in a Multiple Collector-Inductively Coupled Plasma Mass Spectrometer collision-reaction cell: Application to the measurements of Cs isotopes in spent nuclear fuel samples

    Energy Technology Data Exchange (ETDEWEB)

    Granet, M. [Commissariat a l' Energie Atomique, DEN/DPC/SECR/LANIE, 91191 Gif-sur-Yvette Cedex (France)], E-mail: mathieu.granet@cea.fr; Nonell, A.; Favre, G. [Commissariat a l' Energie Atomique, DEN/DPC/SECR/LANIE, 91191 Gif-sur-Yvette Cedex (France); Chartier, F. [Commissariat a l' Energie Atomique, DEN/DPC, 91191 Gif-sur-Yvette Cedex (France); Isnard, H.; Moureau, J.; Caussignac, C.; Tran, B. [Commissariat a l' Energie Atomique, DEN/DPC/SECR/LANIE, 91191 Gif-sur-Yvette Cedex (France)

    2008-11-15

    In the general frameworks of the nuclear fuel cycle and environmental research field, the Cs isotopic composition must be known with high precision and accuracy. The direct determination of Cs isotopes by mass spectrometry techniques is generally hampered by the presence of Ba isobaric interferences however. Here we present a new method which takes advantage of the collision-reaction cell based Multiple Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) and allows to analyse Cs isotopes in the presence of Ba without prior separation step. The addition of N{sub 2}O gas in the cell leads to an antagonistic behavior of Cs{sup +} and Ba{sup +} as the latter reacts with the gas to form BaO{sup +} and BaOH{sup +} products whereas Cs{sup +} remains unreactive. The efficiency of the method was demonstrated for an UOx sample by comparing the results obtained (1) from the measurements of pure Cs fractions and (2) from Fission Products fractions containing more than 30 ionisable elements in addition to Cs, Ba, and where U and Pu were previously removed by using ion exchange resin. An excellent agreement is achieved between each set of experiments with an external reproducibility always better than 0.5% (RSD, k = 2). This study confirms the strong potential of collision-reaction cell to measure Cs isotopes in presence of interfering Ba, precluding therefore former systematic chemical separations.

  9. Measurement of activation cross-sections for high-energy neutron-induced reactions of Bi and Pb

    Energy Technology Data Exchange (ETDEWEB)

    Zaman, Muhammad; Kim, Guinyun; Kim, Kwangsoo; Shahid, Muhammad [Kyungpook National University, Department of Physics and Center for High Energy Physics, Daegu (Korea, Republic of); Naik, Haladhara [Kyungpook National University, Department of Physics and Center for High Energy Physics, Daegu (Korea, Republic of); Bhabha Atomic Research Centre, Radiochemistry Division, Trombay, Mumbai (India); Lee, Manwoo [Dongnam Inst. of Radiological and Medical Sciences, Research Center, Busan (Korea, Republic of)

    2015-08-15

    The cross-sections for {sup 209}Bi(n, 4n){sup 206}Bi, {sup 209}Bi(n, 5n){sup 205}Bi, {sup nat}Pb(n,xn){sup 204m}Pb, {sup nat}Pb(n,xn){sup 203}Pb, {sup nat}Pb(n,xn){sup 202m}Pb,{sup nat}Pb(n,xn){sup 201}Pb, {sup nat}Pb(n,xn){sup 200}Pb, {sup nat}Pb(n,αxn){sup 203}Hg and {sup nat}Pb(n, pxn){sup 202}Tl reactions were determined at the Korean Institute of Radiological and Medical Sciences (KIRAMS), Korea in the neutron energy range of 15.2 to 37.2 MeV. The above cross-sections were obtained by using the activation and off-line γ-ray spectrometric technique. The quasi-monoenergetic neutron used for the above reactions are based on the {sup 9}Be(p, n) reaction. Simulations of the spectral flux from the Be target were done using the MCNPX program. The cross-sections were estimated with the TALYS 1.6 code using the default parameter. The data from the present work and literature were compared with the data from the EAF-2010 and the TENDL-2013 libraries, and calculated values of TALYS 1.6 code. It shows that appropriate level density model, the γ-ray strength function, and the spin cut-off parameter are needed to obtain a good agreement between experimental data and theoretical values from TALYS 1.6 code. (orig.)

  10. Experimental measurements of the 15O(alpha,gamma)19Ne reaction rate and the stability of thermonuclear burning on accreting neutron stars

    International Nuclear Information System (INIS)

    Fisker, J; Tan, W; Goerres, J; Wiescher, M; Cooper, R

    2007-01-01

    Neutron stars in close binary star systems often accrete matter from their companion stars. Thermonuclear ignition of the accreted material in the atmosphere of the neutron star leads to a thermonuclear explosion which is observed as an X-ray burst occurring periodically between hours and days depending on the accretion rate. The ignition conditions are characterized by a sensitive interplay between the accretion rate of the fuel supply and its depletion rate by nuclear burning in the hot CNO cycle and the rp-process. For accretion rates close to stable burning the burst ignition therefore depends critically on the hot CNO breakout reaction 15 O(α, γ) 19 Ne that regulates the flow between the hot CNO cycle and the rapid proton capture process. Until recently, the 15 O(α, γ) 19 Ne reaction rate was not known experimentally and the theoretical estimates carried significant uncertainties. In this paper we perform a parameter study of the uncertainty of this reaction rate and determine the astrophysical consequences of the first measurement of this reaction rate. Our results corroborate earlier predictions and show that theoretically burning remains unstable up to accretion rates near the Eddington limit, in contrast to astronomical observations

  11. Precipitation Stages and Reaction Kinetics of AlMgSi Alloys during the Artificial Aging Process Monitored by In-Situ Electrical Resistivity Measurement Method

    Directory of Open Access Journals (Sweden)

    Hong He

    2018-01-01

    Full Text Available The precipitation process and reaction kinetics during artificial aging, precipitate microstructure, and mechanical properties after aging of AlMgSi alloys were investigated employing in-situ electrical resistivity measurement, Transmission Electron Microscopy (TEM observation, and tensile test methods. Three aging stages in sequence, namely formation of GP zones, transition from GP zones to β″ phase, transition from β″ to β′ phase, and coarsening of both phases, were clearly distinguished by the variation of the resistivity. It was discussed together with the mechanical properties and precipitate morphology evolution. Fast formation of GP zones and β″ phase leads to an obvious decrease of the resistivity and increase of the mechanical strength. The formation of β″ phase in the second stage, which contributes to the peak aging strength, has much higher reaction kinetics than reactions in the other two stages. All of these stages finished faster with higher reaction kinetics under higher temperatures, due to higher atom diffusion capacity. The results proved that the in-situ electrical resistivity method, as proposed in the current study, is a simple, effective, and convenient technique for real-time monitoring of the precipitation process of AlMgSi alloys. Its further application for industrial production and scientific research is also evaluated.

  12. Measurement of the reaction 2H(e,e') at 180 degrees close to the deuteron breakup threshold.

    Science.gov (United States)

    Ryezayeva, N; Arenhövel, H; Burda, O; Byelikov, A; Chernykh, M; Enders, J; Griesshammer, H W; Kalmykov, Y; von Neumann-Cosel, P; Ozel, B; Poltoratska, I; Pysmenetska, I; Rangacharyulu, C; Rathi, S; Richter, A; Schrieder, G; Shevchenko, A; Yevetska, O

    2008-05-02

    Inclusive inelastic electron scattering off the deuteron under 180 degrees has been studied at the S-DALINAC close to the breakup threshold at momentum transfers q=0.27 fm;{-1} and 0.74 fm;{-1} with good energy resolution sufficient to map in detail the spin flip M1 response, which governs the starting reaction pn-->dgamma of big-bang nucleosynthesis over most of the relevant temperature region. Results from potential model calculations and (for q=0.27 fm;{-1}) from pionless nuclear effective field theory are in excellent agreement with the data.

  13. Polarization measurements in the pp → pnπ+ and pp → ppπ0 reactions at 517 and 580 MeV

    International Nuclear Information System (INIS)

    Bach, P.; Cantale, G.; Degli-Agosti, S.; Demierre, P.; Favier, B.; Heer, E.; Hess, R.; Lechanoine-Leluc, C.; Leo, W.; Onel, Y.; and others.

    1989-01-01

    The transverse polarization of the outgoing proton in the pp → pnπ + and pp → ppπ 0 reactions was investigated for the first time. The measurements were performed at SIN (now PSI) at 517 and 580 MeV on the pM1 polarized proton beam line with an average beam polarization higher than 82%, using a liquid hydrogen target. A carbon polarimeter spin-analyzed the scattered proton, 3 MWPC's tracked the recoil charged particle and a 3.84 m 2 neutron detector identified the neutral particle and measured TOF's

  14. A study of dissipative processes in the reactions Ar + Au, Ar + Th between 27 and 44 MeV/u measuring the neutron multiplicities

    International Nuclear Information System (INIS)

    Guerreau, D.; Doubre, H.; Galin, J.; Jahnke, U.; Jiang, D.X.; Pouthas, J.; Charvet, J.L.; Frehaut, J.; Lott, B.; Magnago, C.; Morjean, M.; Patin, Y.; Pranal, Y.; Uzureau, J.L.; Ingold, G.; Jacquet, D.

    1987-01-01

    A 4π detector measuring the neutron multiplicities has been used to characterize the degree of violence of the collision. For peripheral collisions, it allows to study the evolution from a massive transfer process towards a participant-spectator type of reaction. Central collisions have been also investigated. From the measurement of the multiplicities of light evaporated particles (n,p,α), the total excitation energy of the composite system has been estimated at 3 incident energies (27, 35, 44 MeV/u). The results indicate clearly the existence of a limiting excitation energy deposition close to 630 MeV, corresponding to a temperature of 5 MeV

  15. SOLVING THE LARGE DISCREPANCY BETWEEN INCLUSIVE AND EXCLUSIVE MEASUREMENTS OF THE 8Li + 4He → 11B + n REACTION CROSS SECTION AT ASTROPHYSICAL ENERGIES

    International Nuclear Information System (INIS)

    La Cognata, M.; Del Zoppo, A.; Alba, R.; Cherubini, S.; Di Pietro, A.; Figuera, P.; Gulino, M.; Lamia, L.; Musumarra, A.; Pellegriti, M. G.; Pizzone, R. G.; Romano, S.; Spitaleri, C.; Tumino, A.; Colonna, N.; Rolfs, C.

    2009-01-01

    A solution of the large discrepancy existing between inclusive and exclusive measurements of the 8 Li + 4 He → 11 B + n reaction cross section at E cm 8 Li + 4 He → 11 B + n cross section data is carried out, setting up a consistent picture in which all the inclusive measurements provide the reliable value of the cross section. New unambiguous signatures of the strong branch pattern non-uniformities, near the threshold of higher 11 B excited levels, are presented and their possible origin, in terms of the cluster structure of the involved excited states of 11 B and 12 Bnuclei, is discussed.

  16. Measurements of the nuclear reaction rates and spectral indices along the radius of the fuel pellets of the IPEN/MB-01 reactor

    International Nuclear Information System (INIS)

    Bitelli, Ulysses d'Utra; Mura, Luis Felipe L.; Fanaro, Leda C.C.B.

    2009-01-01

    This work presents the measures of the nuclear reaction rates along of the radial direction of the fuel pellet by irradiation and posterior gamma spectrometry of a thin slice of fuel pellet of UO 2 at 4.3% enrichment. From its irradiation the rate of radioactive capture and fission are measures as a function of the radius of the pellet disk using a HPGe detector. Diverse lead collimators of changeable diameters have been used for this purpose. Simulating the fuel pellet in the pin fuel of the IPEN/MB-01 reactor, a thin disk is used, being inserted in the interior of a dismountable fuel rod. This fuel rod is then placed in the central position of the IPEN/MB-01 reactor core and irradiated during 1 hour under a neutron flux of 5.10 8 n/cm 2 s. The nuclear reaction of radioactive capture occurs in the atoms of U- 238 that when absorbs a neutron transmutes into U- 239 of half-life of only 23 minutes. Thus, it is opted for the detection of the Np- 239 , radionuclide derivative of the radioactive decay of the U- 239 and that has a measurable half-life (2.335 days). In gamma spectrometry 11 collimators with different diameters have been used, consequently, the gamma spectrometry is made in function of the diameter (radius) of the irradiated UO 2 fuel pellet disk, thus is possible to get the average value of the counting for each collimator in function of the specific pellet radius. These values are directly proportional to the radioactive capture nuclear reaction rates. The same way the nuclear fission rate occurs in the atoms of the U- 235 that produce different fission products such as Ce- 143 with a yield fission of 5.9% and applying the same procedure the fission nuclear reaction rate is obtained. This work presents some calculated values of nuclear reaction rate of radioactive capture and fission along of the radial direction of the fuel pellet obtained by Monte Carlo methodology using the MCNP-4C code. The relative values obtained are compared with experimental

  17. Measurements of acetone yields from the OH-initiated oxidation of terpenes by proton-transfer-reaction mass spectrometry

    International Nuclear Information System (INIS)

    Wisthaler, A.; Lindinger, W.; Jensen, N.R.; Winterhalter, R.; Hjorth, J.

    2002-01-01

    Biogenic VOCs (Volatile Organic Compounds) are known to be emitted in large quantities from vegetation exceeding largely global emissions of anthropogenic VOCs. Monoterpenes (C 10 H 16 ) are important constituents of biogenic VOC emissions. The atmospheric oxidation of Monoterpenes appears to be a potentially relevant source of acetone in the atmosphere. Acetone is present as a significant trace gas in the whole troposphere and influences in particular the atmospheric chemistry in the upper troposphere by substantially contributing to the formation of HO x radicals and peroxyacetyl nitrate (PAN). Acetone is formed promptly, following attack by the OH-radical on the terpene, via a series of highly unstable radical intermediates, but it is also formed slowly via the degradation of stable non-radical intermediates such as pinonaldehyde and nopinone. In order to investigate the relative importance of these processes, the OH-initiated oxidation of α-pinene and β-pinene was investigated in a chamber study, where the concentrations of monoterpenes, acetone, pinonaldehyde and nopinone were monitored by proton-transfer-reaction mass spectrometry (PTR-MS). It was found that significant amounts of acetone are formed directly, whenα-pinene and β-pinene are oxidized by the OH radical, but also secondary chemistry (degradation of primary reaction products) gives a significant contribution to the formation of acetone from monoterpenes. It can be concluded that atmospheric oxidation of monoterpenes contributes a significant fraction to the global acetone source strength. (nevyjel)

  18. Thick target yield measurement of 211At through the nuclear reaction 209Bi(α, 2n)

    Science.gov (United States)

    Alfarano, A.; Abbas, K.; Holzwarth, U.; Bonardi, M.; Groppi, F.; Alfassi, Z.; Menapace, E.; Gibson, P. N.

    2006-05-01

    Radionuclide Therapy (RNT) and Radioimmunotherapy (RIT) are potentially of great interest for cancer therapy. In many therapeutic applications alpha emitters should be much more effective than already-approved beta emitters due to the short range and high linear energy transfer of alpha particles. 213Bi is an important alpha emitter already used in clinical trials but the half-life of this radioisotope is short (46 minutes) and so its use is limited for certain therapies. 211At is potentially very interesting for medical purposes because of its longer half-life of 7.2 hours, and suitable decay scheme. We have studied the cyclotron-based production of 211At via the reaction 209Bi(α, 2n), this production route probably being the most promising in the long term. The energy dependence of thick target yields and the reaction cross sections for the production of 211At and 210At were determined and found to be in good agreement with literature. The best energy to produce 211At is 28-29 MeV. The possible production of the undesired, highly radiotoxic, and long-lived alpha-emitting 210Po (138.38 days), which is produced from decay of 210At, is also discussed.

  19. Anaerobic reductive dechlorination of tetrachloroethene: how can dual Carbon-Chlorine isotopic measurements help elucidating the underlying reaction mechanism?

    Science.gov (United States)

    Badin, Alice; Buttet, Géraldine; Maillard, Julien; Holliger, Christof; Hunkeler, Daniel

    2014-05-01

    Chlorinated ethenes (CEs) such as tetrachloroethene (PCE) are common persistent groundwater contaminants. Among clean-up strategies applied to sites affected by such pollution, bioremediation has been considered with a growing interest as it represents a cost-effective, environmental friendly approach. This technique however sometimes leads to an incomplete and slow biodegradation of CEs resulting in an accumulation of toxic metabolites. Understanding the reaction mechanisms underlying anaerobic reductive dechlorination would thus help assessing PCE biodegradation in polluted sites. Stable isotope analysis can provide insight into reaction mechanisms. For chlorinated hydrocarbons, carbon (C) and chlorine (Cl) isotope data (δ13C and δ37Cl) tend to show a linear correlation with a slope (m ≡ ɛC/ɛCl) characteristic of the reaction mechanism [1]. This study hence aims at exploring the potential of a dual C-Cl isotope approach in the determination of the reaction mechanisms involved in PCE reductive dechlorination. C and Cl isotope fractionation were investigated during anaerobic PCE dechlorination by two bacterial consortia containing members of the Sulfurospirillum genus. The specificity in these consortia resides in the fact that they each conduct PCE reductive dechlorination catalysed by one different reductive dehalogenase, i.e. PceADCE which yields trichloroethene (TCE) and cis-dichloroethene (cDCE), and PceATCE which yields TCE only. The bulk C isotope enrichment factors were -3.6±0.3 o for PceATCE and -0.7±0.1o for PceADCE. The bulk Cl isotope enrichment factors were -1.3±0.2 o for PceATCE and -0.9±0.1 o for PceADCE. When applying the dual isotope approach, two m values of 2.7±0.1 and 0.7±0.2 were obtained for the reductive dehalogenases PceATCE and PceADCE, respectively. These results suggest that PCE can be degraded according to two different mechanisms. Furthermore, despite their highly similar protein sequences, each reductive dehalogenase seems

  20. Rate constant for the H˙ + H2O → ˙OH + H2 reaction at elevated temperatures measured by pulse radiolysis.

    Science.gov (United States)

    Muroya, Y; Yamashita, S; Lertnaisat, P; Sanguanmith, S; Meesungnoen, J; Jay-Gerin, J-P; Katsumura, Y

    2017-11-22

    Maintaining the structural integrity of materials in nuclear power plants is an essential issue associated with safe operation. Hydrogen (H 2 ) addition or injection to coolants is a powerful technique that has been widely applied such that the reducing conditions in the coolant water avoid corrosion and stress corrosion cracking (SCC). Because the radiation-induced reaction of ˙OH + H 2 → H˙ + H 2 O plays a crucial role in these systems, the rate constant has been measured at operation temperatures of the reactors (285-300 °C) by pulse radiolysis, generating sufficient data for analysis. The reverse reaction H˙ + H 2 O → ˙OH + H 2 is negligibly slow at ambient temperature; however, it accelerates considerably quickly at elevated temperatures. Although the reverse reaction reduces the effectiveness of H 2 addition, reliable rate constants have not yet been measured. In this study, the rate constants have been determined in a temperature range of 250-350 °C by pulse radiolysis in an aqueous I - solution.

  1. Experimental setup and procedure for the measurement of the {sup 7}Be(n,α)α reaction at n-TOF

    Energy Technology Data Exchange (ETDEWEB)

    Cosentino, L. [INFN Laboratori Nazionali del Sud, Catania (Italy); Musumarra, A. [INFN Laboratori Nazionali del Sud, Catania (Italy); Dipartimento di Fisica e Astronomia DFA, Università di Catania (Italy); Barbagallo, M. [INFN Sezione di Bari (Italy); Pappalardo, A. [INFN Laboratori Nazionali del Sud, Catania (Italy); Colonna, N.; Damone, L. [INFN Sezione di Bari (Italy); Piscopo, M. [INFN Laboratori Nazionali del Sud, Catania (Italy); Finocchiaro, P., E-mail: FINOCCHIARO@LNS.INFN.IT [INFN Laboratori Nazionali del Sud, Catania (Italy); Maugeri, E.; Heinitz, S.; Schumann, D.; Dressler, R.; Kivel, N. [Paul Scherrer Institut, Nuclear Energy and Safety Research Department, 5232 Villigen (Switzerland); Aberle, O. [CERN, Geneva (Switzerland); Andrzejewski, J. [Uniwersytet Łódzki, Lodz (Poland); Audouin, L. [Institut de Physique Nucléaire, CNRS-IN2P3, Univ. Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex (France); Ayranov, M. [European Commission, DG-Energy (Luxembourg); Bacak, M. [Atominstitut der Österreichischen Universitäten, Technische Universität Wien (Austria); Barros, S. [C2TN-Instituto Superior Tecníco, Universidade de Lisboa (Portugal); Balibrea-Correa, J. [Centro de Investigaciones Energeticas Medioambientales y Tecnológicas (CIEMAT), Madrid (Spain); and others

    2016-09-11

    The newly built second experimental area EAR2 of the n-TOF spallation neutron source at CERN allows to perform (n, charged particles) experiments on short-lived highly radioactive targets. This paper describes a detection apparatus and the experimental procedure for the determination of the cross-section of the {sup 7}Be(n,α)α reaction, which represents one of the focal points toward the solution of the cosmological Lithium abundance problem, and whose only measurement, at thermal energy, dates back to 1963. The apparently unsurmountable experimental difficulties stemming from the huge {sup 7}Be γ-activity, along with the lack of a suitable neutron beam facility, had so far prevented further measurements. The detection system is subject to considerable radiation damage, but is capable of disentangling the rare reaction signals from the very high background. This newly developed setup could likely be useful also to study other challenging reactions requiring the detectors to be installed directly in the neutron beam.

  2. Three years of cross-section measurements of (n,xn threshold reactions at TSL Uppsala and NPI Řež

    Directory of Open Access Journals (Sweden)

    Majerle M.

    2010-10-01

    Full Text Available We use (n,xn threshold reactions in various materials to measure high energy neutron flux from spallation reactions. Unfortunately, no experimental cross-section data exist for reactions with x higher than four and neutron energies over ∼  40  MeV. With the support from EFNUDAT we performed seven successful (n,xn cross-section measurements in two campaigns exploiting the quasi-monoenergetic neutron source at The Svedberg Laboratory in Uppsala, Sweden. Neutron energies from the 7Li(p, n7Be based source were in the region 22 to 94 MeV. We carried out additional four irradiations with neutron energies from 17 up to 34 MeV using the quasi-monoenergetic neutron source of the Nuclear Physics Institute in Řež. We studied Al, Au, Bi, I, In, and Ta materials. Although we used different neutron sources, gamma detectors and foil geometries, we obtained consistent results. We observed good agreement with the data in EXFOR, so we believe we have understood and solved all possible sources of uncertainties.

  3. Direct measurements of the total rate constant of the reaction NCN + H and implications for the product branching ratio and the enthalpy of formation of NCN.

    Science.gov (United States)

    Fassheber, Nancy; Dammeier, Johannes; Friedrichs, Gernot

    2014-06-21

    The overall rate constant of the reaction (2), NCN + H, which plays a key role in prompt-NO formation in flames, has been directly measured at temperatures 962 K rate constants are best represented by the combination of two Arrhenius expressions, k2/(cm(3) mol(-1) s(-1)) = 3.49 × 10(14) exp(-33.3 kJ mol(-1)/RT) + 1.07 × 10(13) exp(+10.0 kJ mol(-1)/RT), with a small uncertainty of ±20% at T = 1600 K and ±30% at the upper and lower experimental temperature limits.The two Arrhenius terms basically can be attributed to the contributions of reaction channel (2a) yielding CH + N2 and channel (2b) yielding HCN + N as the products. A more refined analysis taking into account experimental and theoretical literature data provided a consistent rate constant set for k2a, its reverse reaction k1a (CH + N2 → NCN + H), k2b as well as a value for the controversial enthalpy of formation of NCN, ΔfH = 450 kJ mol(-1). The analysis verifies the expected strong temperature dependence of the branching fraction ϕ = k2b/k2 with reaction channel (2b) dominating at the experimental high-temperature limit. In contrast, reaction (2a) dominates at the low-temperature limit with a possible minor contribution of the HNCN forming recombination channel (2d) at T < 1150 K.

  4. Reaction Automata

    OpenAIRE

    Okubo, Fumiya; Kobayashi, Satoshi; Yokomori, Takashi

    2011-01-01

    Reaction systems are a formal model that has been introduced to investigate the interactive behaviors of biochemical reactions. Based on the formal framework of reaction systems, we propose new computing models called reaction automata that feature (string) language acceptors with multiset manipulation as a computing mechanism, and show that reaction automata are computationally Turing universal. Further, some subclasses of reaction automata with space complexity are investigated and their la...

  5. Books average previous decade of economic misery.

    Science.gov (United States)

    Bentley, R Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios

    2014-01-01

    For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.

  6. Measurement of cross-sections for produced radionuclide in proton induced reactions on natHf up to 45 MeV

    International Nuclear Information System (INIS)

    Shahid, Muhammad; Kim, Kwangsoo; Naik, Haladhara; Kim, Guinyun

    2014-01-01

    We measured production cross-sections of Hf, Lu, and Ta radioisotopes from proton-induced reaction of nat Hf by using a stacked-foil activation and off-line γ-ray spectrometric technique at the MC-50 cyclotron of the Korea Institute of Radiological and Medical Sciences. The results were compared with the reported experimental data as well as the theoretical calculations based on the TALYS 1.4 code. The present results in the energy region from the threshold energy to 45 MeV are in general good agreement with the other experimental data and calculated results. The present experimental results will play an important role in enrichment of the literature data base for proton-induced reactions on natural hafnium leading to various applications. Some of the investigated radionuclides (e.g. 177g Lu) have remarkable applications in the field of nuclear medicine, a thin layer activation analysis, and a trace element analysis

  7. Towards an activation cross section measurement of the 17O(p,γ)18F reaction in a wide energy range

    Science.gov (United States)

    Ornelas, A.; Gyürky, Gy.; Halász, Z.; Oláh, Cs. M.; Fülöp, Zs.; Rajta, I.; Vajda, I.

    2018-01-01

    The CNO cycles are fusion processes in stars that convert hydrogen to helium. These hydrogen burning processes occur in several sites and stages of stellar evolution, such as red giants, asymptotic giant branch (AGB) stars, massive stars, and classical novae. One of the important reactions in the CNO-III and CNO-IV cycles is 17O(p,γ)18F [1]. The only available total cross section measurement in a wide energy range for this reaction dates back to several decades ago [2] which makes the theoretical extrapolation to astrophysical energies more difficult and introduces uncertainty. The aim of the present work is to provide precise total cross section data in the energy range between about 500 keV and the 2MeV using the activation method. The experimental campaign at the new tandetron accelerator of Atomki is in progress.

  8. Monte Carlo Simulation of Neutron Background Sources in the Measurement of the ^12C(α,γ)^16O Reaction Rate

    Science.gov (United States)

    Gullikson, Kevin; Ugalde, Claudio

    2009-10-01

    The ^12C(α, γ)^16O reaction rate strongly affects the relative abundances of chemical elements, as well as when core collapse supernovae occur. In a proposed experiment, a water-filled bubble chamber will be used to measure the reverse reaction rate. A potential background source is photoneutrons from the γ-ray beam collimator entering the bubble chamber and generating a false signal. To minimize this effect, a Monte Carlo simulation has been performed to compare the number of photoneutrons created in lead, copper, and aluminum collimators. The simulation also compared the effectiveness of concrete, polyethylene, and water neutron shields. It was found that 30 cm of copper would be an effective collimator, and 30-40 cm of polyethylene a satisfactory neutron shield.

  9. First measurements of spin correlations in the n{sup →}p{sup →}→dπ{sup 0} reaction

    Energy Technology Data Exchange (ETDEWEB)

    Shmakova, V. [Institut für Kernphysik and Jülich Centre for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Mchedlishvili, D. [Institut für Kernphysik and Jülich Centre for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); High Energy Physics Institute, Tbilisi State University, GE-0186 Tbilisi, Georgia (United States); Dymov, S., E-mail: s.dymov@fz-juelich.de [Institut für Kernphysik and Jülich Centre for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Azaryan, T. [Laboratory of Nuclear Problems, Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Barsov, S. [St. Petersburg Nuclear Physics Institute, RU-188350 Gatchina (Russian Federation); Chiladze, D. [Institut für Kernphysik and Jülich Centre for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); High Energy Physics Institute, Tbilisi State University, GE-0186 Tbilisi, Georgia (United States); Engels, R. [Institut für Kernphysik and Jülich Centre for Hadron Physics, Forschungszentrum Jülich, D-52425 Jülich (Germany); and others

    2013-11-04

    The transverse spin correlations A{sub x,x} and A{sub y,y} in the n{sup →}p{sup →}→dπ{sup 0} reaction have been measured for the first time in quasi-free kinematics at the COSY-ANKE facility using a polarised deuteron beam incident on a polarised hydrogen cell target. The results obtained for neutron energies close to 353 MeV and 600 MeV are in good agreement with the partial wave analysis of data on the isospin-related pp→dπ{sup +} reaction, though the present results cover kinematic regions that are largely absent from existing data sets.

  10. Multi-site assessment of the precision and reproducibility of multiple reaction monitoring–based measurements of proteins in plasma

    Science.gov (United States)

    Addona, Terri A; Abbatiello, Susan E; Schilling, Birgit; Skates, Steven J; Mani, D R; Bunk, David M; Spiegelman, Clifford H; Zimmerman, Lisa J; Ham, Amy-Joan L; Keshishian, Hasmik; Hall, Steven C; Allen, Simon; Blackman, Ronald K; Borchers, Christoph H; Buck, Charles; Cardasis, Helene L; Cusack, Michael P; Dodder, Nathan G; Gibson, Bradford W; Held, Jason M; Hiltke, Tara; Jackson, Angela; Johansen, Eric B; Kinsinger, Christopher R; Li, Jing; Mesri, Mehdi; Neubert, Thomas A; Niles, Richard K; Pulsipher, Trenton C; Ransohoff, David; Rodriguez, Henry; Rudnick, Paul A; Smith, Derek; Tabb, David L; Tegeler, Tony J; Variyath, Asokan M; Vega-Montoto, Lorenzo J; Wahlander, Åsa; Waldemarson, Sofia; Wang, Mu; Whiteaker, Jeffrey R; Zhao, Lei; Anderson, N Leigh; Fisher, Susan J; Liebler, Daniel C; Paulovich, Amanda G; Regnier, Fred E; Tempst, Paul; Carr, Steven A

    2010-01-01

    Verification of candidate biomarkers relies upon specific, quantitative assays optimized for selective detection of target proteins, and is increasingly viewed as a critical step in the discovery pipeline that bridges unbiased biomarker discovery to preclinical validation. Although individual laboratories have demonstrated that multiple reaction monitoring (MRM) coupled with isotope dilution mass spectrometry can quantify candidate protein biomarkers in plasma, reproducibility and transferability of these assays between laboratories have not been demonstrated. We describe a multilaboratory study to assess reproducibility, recovery, linear dynamic range and limits of detection and quantification of multiplexed, MRM-based assays, conducted by NCI-CPTAC. Using common materials and standardized protocols, we demonstrate that these assays can be highly reproducible within and across laboratories and instrument platforms, and are sensitive to low µg/ml protein concentrations in unfractionated plasma. We provide data and benchmarks against which individual laboratories can compare their performance and evaluate new technologies for biomarker verification in plasma. PMID:19561596

  11. Large scale collective modeling the final 'freeze out' stages of energetic heavy ion reactions and calculation of single particle measurables from these models

    Energy Technology Data Exchange (ETDEWEB)

    Nyiri, Agnes

    2005-07-01

    -relativistic heavy ion reactions is an important hadronic observable sensitive to the early stages of system evolution. The flow analysis involves the particles, which have already been frozen out. Therefore, to perform realistic flow computations from the Multi Module Model we need a complete freeze out description and a well identified freeze out surface. However, the freeze out module is still not ready. Although we have not yet been able to evaluate collective flow using the Multi Module Model, the method and code for the calculation of flow components has been worked out in an independent module. This module is completed and can be coupled to the previous modules when those are ready for use. In order to test the code, we have calculated directed and elliptic flow from a tilted, ellipsoidally expanding source using a simple, blast wave type of model. This model was developed directly for this aim based on Buda-Lund hydro models. Although, this oversimplified blast wave model is not suitable to reproduce the experimental data--which will be an important task in the future to check our Multi Module Model--it has provided us with important information. We have found that the directed flow, is very sensitive to the correct identification of the reaction plane included the determination of the impact parameter vector, and can be misinterpreted by some experimental methods. We have shown that misidentification of the reaction plane may even set the directed flow to zero by construction. We have presented results of the rapidity dependence of the directed flow, v1, and elliptic flow, v2, furthermore, the transverse momentum dependence of v2. We have also investigated the dependence of the flow pattern on the initial geometry of the fireball by calculating flow components from two ellipsoidal sources with the same thermodynamical properties but different shape. The code determining the freeze out hypersurface should still be improved in order to avoid inaccuracies in the further

  12. Self-Described Differences Between Legs in Ballet Dancers: Do They Relate to Postural Stability and Ground Reaction Force Measures?

    Science.gov (United States)

    Mertz, Laura; Docherty, Carrie

    2012-12-01

    Ballet technique classes are designed to train dancers symmetrically, but they may actually create a lateral bias. It is unknown whether dancers in general are functionally asymmetrical, or how an individual dancer's perceived imbalance between legs might manifest itself. The purpose of this study was to examine ballet dancers' lateral preference by analyzing their postural stability and ground reaction forces in fifth position when landing from dance-specific jumps. Thirty university ballet majors volunteered to participate in this study. The subjects wore their own ballet technique shoes and performed fundamental ballet jumps out of fifth position on a force plate. The force plate recorded center of pressure (COP) and ground reaction force (GRF) data. Each subject completed a laterality questionnaire that determined his or her preferred landing leg for ballet jumps, self-identified stronger leg, and self-identified leg with better balance. All statistical comparisons were made between the leg indicated on the laterality questionnaire and the other leg (i.e., if the dancer's response to a question was "left," the comparison was made with the left leg as the "preferred" leg and the right leg as the "non-preferred leg"). No significant differences were identified between the limbs in any of the analyses conducted (all statistical comparisons produced p values > 0.05). The results of this study indicate that a dancer's preferential use of one limb over the other has no bearing on GRFs or balance ability after landing jumps in ballet. Similarly, dancers' opinions of their leg characteristics (such as one leg being stronger than the other) seem not to correlate with the dancers' actual ability to absorb GRFs or to balance when landing from ballet jumps.

  13. Measurement of sub threshold resonance contributions to fusion reactions: the case of the 13C(α, n)16O astrophysical neutron source

    Science.gov (United States)

    La Cognata, M.; Spitaleri, C.; Trippella, O.; Kiss, G. G.; Rogachev, G. V.; Mukhamedzhanov, A. M.; Avila, M.; Guardo, G. L.; Koshchiy, E.; Kuchera, A.; Lamia, L.; Puglia, S. M. R.; Romano, S.; Santiago, D.; Spartà, R.

    2015-01-01

    The 13C(α, n)16O reaction is the neutron source for the main component of the s-process. It is is active inside the helium-burning shell of asymptotic giant branch stars, at temperatures ≲ 108 K. In this temperature region, corresponding to an energy interval of 140 - 230 keV, the 13C(α, n)16O cross section is dominated by the -3 keV sub-threshold resonance due to the 6.356 MeV level in 17O. Direct measurements could not establish its contribution owing to the Coulomb barrier between interacting nuclei, strongly reducing the cross section at astrophysical energies. Similarly, indirect measurements and extrapolations yielded inconsistent results, calling for further investigations. The Trojan Horse Method was applied to the 13C(6Li, n16O)d quasi-free reaction to access the low as well as the negative energy region of the 13C(α, n)16O reaction. By using the generalized R-matrix approach, the asymptotic normalization coefficient (C˜17O(1/2+)α13C)2 of the 6.356 MeV level was deduced. For the first time, the Trojan Horse Method and the asymptotic normalization coefficient were used in synergy. Our indirect approach lead to (C˜17O(1/2+)α13C)2 = 7.7-1.5+1.6 fm-1, slightly larger than the values in the literature, determining a 13C(α, n)16O reaction rate slightly larger than the one in the literature at temperatures lower than 108 K, with enhanced accuracy.

  14. From Rate Measurements to Mechanistic Data for Condensed Matter Reactions: A Case Study Using the Crystallization of [Zn(OH26][ZnCl4

    Directory of Open Access Journals (Sweden)

    Berkley G. Hillis

    2016-12-01

    Full Text Available The kinetics of crystallization of the R = 3 hydrate of zinc chloride, [Zn(OH26][ZnCl4], is measured by time-resolved synchrotron x-ray diffraction, time-resolved neutron diffraction, and by differential scanning calorimetry. It is shown that analysis of the rate data using the classic Kolmogorov, Johnson, Mehl, Avrami (KJMA kinetic model affords radically different rate constants for equivalent reaction conditions. Reintroducing the amount of sample measured by each method into the kinetic model, using our recently developed modified-KJMA model (M-KJMA, it is shown that each of these diverse rate measurement techniques can give the intrinsic, material specific rate constant, the velocity of the phase boundary, vpb. These data are then compared to the velocity of the crystallization front directly measured optically. The time-resolved diffraction methods uniquely monitor the loss of the liquid reactant and formation of the crystalline product demonstrating that the crystallization of this hydrate phase proceeds through no intermediate phases. The temperature dependent vpb data are then well fit to transition zone theory to extract activation parameters. These demonstrate that the rate-limiting component to this crystallization reaction is the ordering of the waters (or protons of hydration into restricted positions of the crystalline lattice resulting in large negative entropy of activation.

  15. Advanced foil activation techniques for the measurement of within-pin distributions of the 63Cu(n,γ)64Cu reaction rate in nuclear fuel

    International Nuclear Information System (INIS)

    Macku, K.; Jatuff, F.; Murphy, M.F.; Joneja, O.P.; Bischofberger, R.; Chawla, R.

    2006-01-01

    Different foil activation techniques have been used for measuring spatial distributions of the 63 Cu(n,γ) 64 Cu reaction within two pins of a SVEA-96 Optima2 boiling water reactor fuel assembly, at the critical facility PROTEUS. This reaction is of interest because its 1/v cross-section gives it a good representation of the 235 U fission rate. Initially, radial capture rate profiles were measured with mechanically punched copper foils. More detailed profiles were then determined by using a 0.2 mm copper wire spiral (∼200 μm resolution), as well as 5-, 10-, and 20-ring UV-lithography, electroplating, and molding (UV-LIGA) foils (up to a 100 μm resolution). For azimuthal measurements, apart from manually cut activation foils (into 8 sectors), 8- and 12-sector LIGA foils were used. The highly versatile LIGA foils have the additional advantage of being very easily separated into individual pieces after irradiation without the use of punches or other cutting tools. In order to account for the invasive character of the foil activation techniques, corrections to account for sample perturbations and for self-shielding effects were determined via simplified Monte Carlo (MCNP4C) modeling of the experimental setup. The final results from the various measurements of 63 Cu(n,γ) 64 Cu within-pin distributions have been compared with MCNP computations employing a detailed model of the full SVEA Optima2 fuel assembly

  16. On-line and precise measurement of iron wear using thin layer activation reactions by proton beam

    International Nuclear Information System (INIS)

    Kosako, Toshiso; Nishimura, Kazuo.

    1990-01-01

    For the purpose of the on-line measurement of iron wear, thin layer activation (TLA) method or surface layer activation (SLA) method has been carried out since early 1970s. This method uses the irradiation of charged particle beam like protons from an accelerator onto a metal surface to produce a thin activated layer of several tens μm. The wear of this activated layer is measured by nondestructive on-line method with a radiation detector. There are two methods of the measurement. One is the activity loss measurement on the surface, and the other is the activity measurement of the metal debris collected in a filter. The former method is considered here. The purpose it to measure the wear of engine cam noses to help the development of good engine oil. Proton beam irradiation with a tandem van de Graaff accelerator, wear calibration using a gamma ray spectrometer, on-line wear measurement of cam noses of car engines by TLA method and so on are reported. The 7.00 MeV proton beam from a van de Graaff accelerator was used for activation, and Co-56, Co-57 and Co-58 were obtained in thin layers. (K.I.)

  17. In vivo 31P nuclear magnetic resonance saturation transfer measurements of phosphate exchange reactions in the yeast Saccharomyces cerevisiae

    International Nuclear Information System (INIS)

    Campbell, S.L.; Jones, K.A.; Schulman, R.G.

    1985-01-01

    31 P saturation transfer techniques have been used to measure phosphate kinetics in the yeast Saccharomyces cerevisiae. The phosphate comsumption rate observed in acetate grown mid-log cells was combined with measurements of O 2 consumption to yield P/O ratios of 2.2 and 2.9, for cells respiring on glucose and ethanol, respectively. However, no phosphate consumption activity was observed in saturation transfer experiments on anaerobic glucose fed cells. The phosphate consumption rates measured by saturation transfer in cells respiring on glucose and ethanol was attributed to the unidirectional rates of mitochondrial ATP synthesis. (Auth.)

  18. Spectroscopic factors measurements in the s,d and f,p shells below and above the Coulomb barrier by (3He,d) reactions

    International Nuclear Information System (INIS)

    Baghdadi, Ahmed.

    1974-01-01

    The overlap of t and d or 3 He and d wave functions may be measured by one neutron transfer in (d,t) or one proton transfer in ( 3 He,d). The measurement of the resulting normalization constant has been performed in subcoulombic conditions in the case of 58 Ni( 3 He,d) 59 Cu and 60 Ni( 3 He,d) 61 Cu leading to the first 3/2 - and 1/2 - states with a position sensitive detector in a Buechner spectrograph. The result: D 2 =2.7+-0.2 10 4 MeV 2 fm 3 is in agreement with the D 2 measurement for (t,d) reactions [3.1+-0.2 10 4 MeV 2 fm 3 ] and with the theoretical value proposed by L.J.B. Goldfarg and coworkers. This result was used for a determination of the spectroscopic factors of the 1.379MeV 3/2 - state, the 1.507MeV 1/2 - state and the 1.758MeV 3/2 - state in 57 Co. The subcoulombic approximation is also shown to be valid even in the case of (d,p) reactions, by the measurement of angular distributions and excitation curves of 60 Ni(d,p) reactions leading to the excited states at 4.760MeV (l=2) and 4.907MeV (l=0). In the second part, some spectroscopic factors in the s-d shell were measured by ( 3 He,d) reactions at MP Tandem energies. In the case of 27 Al( 3 He,d) 28 Si (states at 4.62, 6.88, 6.89, 9.32 and 0.38MeV) the normalization constant D 0 2 (deduced from the subcoulombic D 2 value) together with the first order finite range approximation leads to spectroscopic factors in good agreement with Wildenthal theoretical results. For 28 Si( 3 He,d) 29 p however, the values are too high compared to 29 Si. The conclusion is that it is better to use the DWBA treatment at subcoulombic energies everytime the experimental conditions may be fulfilled [fr

  19. Development, improvement and calibration of neutronic reaction rate measurements: elaboration of a base of standard techniques; Developpement, amelioration et calibration des mesures de taux de reaction neutroniques: elaboration d`une base de techniques standards

    Energy Technology Data Exchange (ETDEWEB)

    Hudelot, J.P

    1998-06-19

    In order to improve and to validate the neutronic calculation schemes, perfecting integral measurements of neutronic parameters is necessary. This thesis focuses on the conception, the improvement and the development of neutronic reaction rates measurements, and aims at building a base of standard techniques. Two subjects are discussed. The first one deals with direct measurements by fission chambers. A short presentation of the different usual techniques is given. Then, those last ones are applied through the example of doubling time measurements on the EOLE facility during the MISTRAL 1 experimental programme. Two calibration devices of fission chambers are developed: a thermal column located in the central part of the MINERVE facility, and a calibration cell using a pulsed high flux neutron generator and based on the discrimination of the energy of the neutrons with a time-of-flight method. This second device will soon allow to measure the mass of fission chambers with a precision of about 1 %. Finally, the necessity of those calibrations will be shown through spectral indices measurements in core MISTRAL 1 (UO{sub 2}) and MISTRAL 2 (MOX) of the EOLE facility. In each case, the associated calculation schemes, performed using the Monte Carlo MCNP code with the ENDF-BV library, will be validated. Concerning the second one, the goal is to develop a method for measuring the modified conversion ratio of {sup 238}U (defined as the ratio of {sup 238}U capture rate to total fission rate) by gamma-ray spectrometry of fuel rods. Within the framework of the MISTRAL 1 and MISTRAL 2 programmes, the measurement device, the experimental results and the spectrometer calibration are described. Furthermore, the MCNP calculations of neutron self-shielding and gamma self-absorption are validated. It is finally shown that measurement uncertainties are better than 1 %. The extension of this technique to future modified conversion ratio measurements for {sup 242}Pu (on MOX rods) and

  20. Selecting measures to prevent deleterious alkali-silica reaction in concrete : rationale for the AASHTO PP65 prescriptive approach.

    Science.gov (United States)

    2012-10-01

    PP65-11 provides two approaches for selecting preventive measures: (i) a performance approach based on laboratory testing, and (ii) a prescriptive approach based on a consideration of the reactivity of the aggregate, type and size of structure, expos...

  1. Fractional momentum transfer in incomplete fusion reaction: measurement of recoil range distributions in 20Ne + 159Tb system

    International Nuclear Information System (INIS)

    Ali, R.; Singh, D.; Pachouri, Dipti; Afzal Ansari, M.; Rashid, M.H.

    2007-01-01

    The recoil range distribution (RRD) of several residues have been measured for the system 20 Ne + 159 Tb at 165 MeV beam energy by collecting the recoiling residues in the Al-catcher foils of varying thickness

  2. Total reaction cross sections and neutron-removal cross sections of neutron-rich light nuclei measured by the COMBAS fragment-separator

    Science.gov (United States)

    Hue, B. M.; Isataev, T.; Erdemchimeg, B.; Artukh, A. G.; Aznabaev, D.; Davaa, S.; Klygin, S. A.; Kononenko, G. A.; Khuukhenkhuu, G.; Kuterbekov, K.; Lukyanov, S. M.; Mikhailova, T. I.; Maslov, V. A.; Mendibaev, K.; Sereda, Yu M.; Penionzhkevich, Yu E.; Vorontsov, A. N.

    2017-12-01

    Preliminary results of measurements of the total reaction cross sections σR and neutron removal cross section σ-xn for weakly bound 6He, 8Li, 9Be and 10Be nuclei at energy range (20-35) A MeV with 28Si target is presented. The secondary beams of light nuclei were produced by bombardment of the 22Ne (35 A MeV) primary beam on Be target and separated by COMBAS fragment-separator. In dispersive focal plane a horizontal slit defined the momentum acceptance as 1% and a wedge degrader of 200 μm Al was installed. The Bρ of the second section of the fragment-separator was adjusted for measurements in energy range (20-35) A MeV. Two-neutron removal cross sections for 6He and 10Be and one -neutron removal cross sections 8Li and 9Be were measured.

  3. Systematic effects on cross section data derived from reaction rates in reactor spectra and a re-analysis of 241Am reactor activation measurements

    Science.gov (United States)

    Žerovnik, Gašper; Schillebeeckx, Peter; Becker, Björn; Fiorito, Luca; Harada, Hideo; Kopecky, Stefan; Radulović, Vladimir; Sano, Tadafumi

    2018-01-01

    Methodologies to derive cross section data from spectrum integrated reaction rates were studied. The Westcott convention and some of its approximations were considered. Mostly measurements without and with transmission filter are combined to determine the reaction cross section at thermal energy together with the resonance integral. The accuracy of the results strongly depends on the assumptions that are made about the neutron energy distribution, which is mostly parameterised as a sum of a thermal and an epi-thermal component. Resonance integrals derived from such data can be strongly biased and should only be used in case no other data are available. The cross section at thermal energy can be biased for reaction cross sections which are dominated by low energy resonances. The amplitude of the effect is related to the lower energy limit that is used for the epi-thermal component of the neutron energy distribution. It is less affected by the assumptions on the shape of the energy distribution. When the energy dependence of the cross section is known and information about the neutron energy distribution is available, a method to correct for a bias on the cross section at thermal energy is proposed. Reactor activation measurements to determine the thermal 241Am(n, γ) cross section reported in the literature were reviewed. In case enough information was available, the results were corrected to account for possible biases and included in a least squares fit. These data combined with results of time-of-flight measurements give a capture cross section 720 (14) b for 241Am(n, γ) at thermal energy.

  4. Measurement of the neutral current reaction at high Q{sup 2} in the H1 experiment at HERA II

    Energy Technology Data Exchange (ETDEWEB)

    Shushkevich, Stanislav

    2012-12-15

    This thesis presents inclusive e{sup {+-}}p double and single differential cross section measurements for neutral current deep inelastic scattering of longitudinally polarized leptons on protons as a function of the negative four-momentum transfer squared Q{sup 2} and the Bjorken variable x. The data were collected in the years 2003-2007 in the H1 experiment at HERA with positively and negatively longitudinally polarized lepton beams of 27 GeV and a proton beam of 920 GeV corresponding to the centre-of-mass energy of {radical}(s)=319 GeV. The integrated luminosity is about 330 pb{sup -1}. An overview of the phenomenology of the deep inelastic scattering is given and the experimental apparatus is described. The NC cross section measurement procedure is presented and discussed in details. The measured cross sections are used to investigate electroweak effects at high Q{sup 2}. The proton structure function xF{sub 3}, sensitive to the valence quarks in the proton, is measured. The polarization effects sensitive to the chiral structure of neutral currents are investigated. The Standard Model predictions are found to be in a good agreement with the measurement.

  5. Measurements of neutron-induced capture and fission reactions on $^{235}$ U: cross sections and ${\\alpha}$ ratios, photon strength functions and prompt ${\\gamma}$-ray from fission

    CERN Multimedia

    We propose to measure the neutron-induced capture cross section of the fissile isotope $^{235}$U using a fission tagging set-up. This new set-up has been tested successfully in 2010 and combines the n_TOF 4${\\pi}$ Total Absorption Calorimeter (TAC) with MicroMegas (MGAS) fission detectors. It has been proven that such a combination of detectors allows distinguishing with very good reliability the electromagnetic cascades from the capture reactions from dominant ${\\gamma}$-ray background coming from the fission reactions. The accurate discrimination of the fission background is the main challenge in the neutron capture cross section measurements of fissile isotopes. The main results from the measurement will be the associated capture cross section and ${\\alpha}$ ratio in the resolved (0.3-2250 eV) and unresolved (2.25-30 keV) resonance regions. According to the international benchmarks and as it is mentioned in the NEA High Priority Request List (HPRL), the 235U(n,${\\gamma}$) cross section is of utmost impo...

  6. High accuracy measurement of the $^{235}$U(n,f) reaction cross-section in the 10-30 keV neutron energy range

    CERN Multimedia

    The analysis of the neutron flux of n_TOF (in EAR1) revealed an anomaly in the 10-30 keV neutron energy range. While the flux extracted on the basis of the $^{6}$Li(n,t)$^{4}$He and $^{10}$B(n,$\\alpha$)$^{7}$Li reactions mostly agreed with each other and with the results of FLUKA simulations of the neutron beam, the one based on the $^{235}$U(n,f) reaction was found to be systematically lower, independently of the detection system used. A possible explanation is that the $^{235}$U(n,f) crosssection in that energy region, where in principle should be known with an uncertainty of 1%, may be systematically overestimated. Such a finding, which has a negligible influence on thermal reactors, would be important for future fast critical or subcritical reactors. Furthermore, its interest is more general, since the $^{235}$U(n,f) reaction is often used at that energy to determine the neutron flux, or as reference in measurements of fission cross section of other actinides. We propose to perform a high-accuracy, high-r...

  7. Manufacturing of thin films of boron for the measurement of the {sup 10}B(n, {alpha}){sup 7} Li reaction used in BNCT

    Energy Technology Data Exchange (ETDEWEB)

    Smilgys, Barbara; Oliveira, Sandro Guedes de; Hadler Neto, Julio Cesar; Vellame, Igor Alencar [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin; Soares, Cleber Jose; Salim, Leonardo Alfredo [Universidade Estadual Paulista (UNESP), Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas; Coelho, Paulo Rogerio Pinto [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Engenharia Nuclear

    2011-07-01

    Full text: The Boron Neutron Capture Therapy (BNCT) is considered to be a possible treatment for different types of aggressive cancers located in areas of difficult access or which already have metastasis. The working principle of this therapy is the selective delivery of a greater amount of boron to the tumor cells than to the healthy ones, followed by the neutron irradiation that will induce the emission of {alpha} particles through the {sup 10}B(n, {alpha}){sup 7} Li reaction used in BNCT reaction. The high energy deposition of the product particles causes the death of the cells and this therapy becomes much effective if the healthy tissue is less exposed to this radiation. The objective of this work is to develop a method for measuring the rate of this reaction by using thin films of boron. We have manufactured thin films with different concentrations of boron deposited on mica and the thin films were exposed to different irradiation time intervals at the reactor IEA-R1 located at IPEN, Sao Paulo. Here we show our first results on the density and uniformity of the thin films, where the detection of the particles is made using plastic track detectors (CR-39) which have their structures damaged by the passage of ions. (author)

  8. Electrochemical Measurements of the Kinetics of Inhibition of Two FeFe Hydrogenases by O2 Demonstrate That the Reaction Is Partly Reversible.

    Science.gov (United States)

    Orain, Christophe; Saujet, Laure; Gauquelin, Charles; Soucaille, Philippe; Meynial-Salles, Isabelle; Baffert, Carole; Fourmond, Vincent; Bottin, Hervé; Léger, Christophe

    2015-10-07

    The mechanism of reaction of FeFe hydrogenases with oxygen has been debated. It is complex, apparently very dependent on the details of the protein structure, and difficult to study using conventional kinetic techniques. Here we build on our recent work on the anaerobic inactivation of the enzyme [Fourmond et al. Nat. Chem. 2014, 4, 336-342] to propose and apply a new method for studying this reaction. Using electrochemical measurements of the turnover rate of hydrogenase, we could resolve the first steps of the inhibition reaction and accurately determine their rates. We show that the two most studied FeFe hydrogenases, from Chlamydomonas reinhardtii and Clostridium acetobutylicum, react with O2 according to the same mechanism, despite the fact that the former is much more O2 sensitive than the latter. Unlike often assumed, both enzymes are reversibly inhibited by a short exposure to O2. This will have to be considered to elucidate the mechanism of inhibition, before any prediction can be made regarding which mutations will improve oxygen resistance. We hope that the approach described herein will prove useful in this respect.

  9. Total and partial cross sections of the $^{112}$Sn($\\alpha,\\gamma$)$^{116}$Te reaction measured via in-beam $\\gamma$-ray spectroscopy

    OpenAIRE

    Netterdon, L.; Mayer, J.; Scholz, P.; Zilges, A.

    2015-01-01

    An extended database of experimental data is needed to address uncertainties of the nuclear-physics input parameters for Hauser-Feshbach calculations. Especially $\\alpha$+nucleus optical model potentials at low energies are not well known. The in-beam technique with an array of high-purity germanium (HPGe) detectors was successfully applied to the measurement of absolute cross sections of an ($\\alpha$,$\\gamma$) reaction on a heavy nucleus at sub-Coulomb energies. The total and partial cross-s...

  10. The measurement of peripheral blood volume reactions to tilt test by the electrical impedance technique after exercise in athletes

    International Nuclear Information System (INIS)

    Melnikov, A A; Popov, S G; Vikulov, A D; Nikolaev, D V

    2013-01-01

    We have investigated the distribution of peripheral blood volumes in different regions of the body in response to the tilt-test in endurance trained athletes after aerobic exercise. Distribution of peripheral blood volumes (ml/beat) simultaneously in six regions of the body (two legs, two hands, abdomen, neck and ECG) was assessed in response to the tilt-test using the impedance method (the impedance change rate (dZ/dT). Before and after exercise session cardiac stroke (CSV) and blood volumes in legs, arms and neck were higher in athletes both in lying and standing positions. Before exercise the increase of heart rate and the decrease of a neck blood volume in response to tilting was lower (p <0.05) but the decrease of leg blood volumes was higher (p<0.001) in athletes. The reactions in arms and abdomen blood volumes were similar. Also, the neck blood volumes as percentage of CSV (%/CSV) did not change in the control but increased in athletes (p <0.05) in response to the tilt test. After (10 min recovery) the aerobic bicycle exercise (mean HR = 156±8 beat/min, duration 30 min) blood volumes in neck and arms in response to the tilting were reduced equally, but abdomen (p<0.05) and leg blood volumes (p <0.001) were lowered more significantly in athletes. The neck blood flow (%/CSV) did not change in athletes but decreased in control (p<0.01), which was offset by higher tachycardia in response to tilt-test in controls after exercise. The data demonstrate greater orthostatic tolerance in athletes both before and after exercise during fatigue which is due to effective distribution of blood flows aimed at maintaining cerebral blood flow.

  11. Validity and reliability of a simple 'low-tech' test for measuring choice stepping reaction time in older people.

    Science.gov (United States)

    Delbaere, K; Gschwind, Y J; Sherrington, C; Barraclough, E; Garrués-Irisarri, M A; Lord, S R

    2016-11-01

    To establish the psychometric properties of a simple 'low-tech' choice stepping reaction time test (CSRT-M) by investigating its validity and test-retest reliability. Cross-sectional. Community. A total of 169 older people from the control arm of a clinical trial and a convenience sample of 30 older people. Demographic, physical, cognitive and prospective falls data were collected in addition to CSRT-M. The CSRT-M time was taken as the total time to complete 20 steps onto four targets printed on a portable rubber mat. Assessment of the original electronic version (CSRT-E) and re-administration of the CSRT-M the next day was done in 30 participants. Multivariate regression analysis showed that the CSRT-M time was best explained by leaning balance control, quadriceps strength and cognitive functioning (R 2  = 0.44). Performance on the CSRT-M was worse in older participants and participants with a presence of fall risk factors, supporting good discriminant validity. The odds of suffering multiple future falls increased by 74% (odds ratio (OR) = 1.74, 95% CI (confidence interval) = 1.14-2.65, p = 0.010) for each standard deviation increase in CSRT-M, supporting good predictive validity. Criterion validity was confirmed by a strong bivariate correlation between CSRT-M and CSRT-E (0.81, p Test-retest reliability for the CSRT-M was good (intraclass correlation coefficient = 0.74, 95% CI = 0.45-0.88, p test of unplanned volitional stepping (CSRT-M) has excellent predictive validity for future falls, good inter-day test-retest reliability and excellent criterion validity with respect to the well-validated CSRT-E. The CSRT-M, therefore, may be a useful fall risk screening tool for older people.

  12. Psychometric properties of reaction time based experimental paradigms measuring anxiety-related information-processing biases in children

    NARCIS (Netherlands)

    Brown, H.M.; Eley, T.C.; Broeren, S.; MacLeod, C.; Rinck, M.; Hadwin, J.A.; Lester, K.J.

    2014-01-01

    Theoretical frameworks highlight the importance of threat-related information-processing biases for understanding the emergence of anxiety in childhood. The psychometric properties of several tasks measuring these biases and their associations with anxiety were examined in an unselected sample of

  13. Measurement of the G values of hydrogen peroxide in the reactions of typical flavonoids with superoxide anion radicals. Pt.2

    International Nuclear Information System (INIS)

    Zhang Fugen; Wu Jilan

    2002-01-01

    γ irradiated rutin-, catechin-and baicalin-HCOONa aqueous solutions saturated with N 2 O:O 2 = 4:1 were eluted through alumina columns and the G values of hydrogen peroxide generated in the solutions were measured. Different results from former works were obtained and the reasons of the difference were discussed. A precise method was established as follows: hydrogen peroxide should be separated from flavonoids by passing the flavonoids solution through alumina columns before the measurement and the amount of hydrogen peroxide generated from self-oxidation of the flavonoids should be deducted. The G values of hydrogen peroxide in γ irradiated rutin-, catechin- and baicalin- aqueous solution saturated with N 2 O:O 2 = 4:1 were determined to be 8.3 +- 0.2, 5.6 +- 0.2, and 7.8 +- 0.2, separately

  14. Measurement of the $^{242}$Pu(n,f) reaction cross-section at the CERN n_TOF facility

    CERN Document Server

    AUTHOR|(CDS)2080481; Kokkoris, Michael; Vlachoudis, Vasilis

    The accurate knowledge of relevant nuclear data, such as the neutron-induced fission cross sections of various plutonium isotopes and other minor actinides, is crucial for the design of advanced nuclear systems as well as the development of comprehensive theoretical models of the fission process. The $^{242}$Pu(n,f) cross section was measured at the CERN n_TOF facility taking advantage of the wide energy range and the high instantaneous flux of the neutron beam. In this work, results for the $^{242}$Pu(n,f) measurement are presented along with a detailed description of the experimental setup, Monte-Carlo simulations and the analysis procedure, and a theoretical cross section calculation performed with the EMPIRE code.

  15. Solid-state track recorder dosimetry device to measure absolute reaction rates and neutron fluence as a function of time

    Science.gov (United States)

    Gold, Raymond; Roberts, James H.

    1989-01-01

    A solid state track recording type dosimeter is disclosed to measure the time dependence of the absolute fission rates of nuclides or neutron fluence over a period of time. In a primary species an inner recording drum is rotatably contained within an exterior housing drum that defines a series of collimating slit apertures overlying windows defined in the stationary drum through which radiation can enter. Film type solid state track recorders are positioned circumferentially about the surface of the internal recording drum to record such radiation or its secondary products during relative rotation of the two elements. In another species both the recording element and the aperture element assume the configuration of adjacent disks. Based on slit size of apertures and relative rotational velocity of the inner drum, radiation parameters within a test area may be measured as a function of time and spectra deduced therefrom.

  16. Sustainable measures for sewage sludge treatment - evaluating the effects on P reaction in soils and plant P uptake

    Science.gov (United States)

    Shenker, Moshe; Einhoren, Hana

    2016-04-01

    Wastewater treatment, whether for water reusing or for releasing into the environment, results in sewage sludge rich in organic matter and nutrients. If free of pathogens and pollutants, this waste material is a widely used as soil amendment and source of valuable nutrients for agronomic use. Nevertheless, its P/N ratio largely exceeds plant P/N demand. Limiting its application rates according to the P demand of crops will largely limit its application rates and its beneficial effect as a soil amendment and as a source for other nutrients. An alternative approach, in which P is stabilized before application, was evaluated in this study. Anaerobically digested fresh sewage sludge (FSS) was stabilized by aluminum sulfate, ferrous sulfate, and calcium oxide (CaO), as well as by composting with shredded woody yard-waste to produce Al-FSS, Fe-FSS, CaO-FSS, and FSS-compost, respectively. Defined organic-P sources (glucose-1-phosphate and inositol-hexa-phosphate) and a P fertilizer (KH2PO4) were included as well and a control with no P amendments was included as a reference. Each material was applied at a fixed P load of 50 mg kg-1 to each of three soils and P speciation and plants P uptake were tested along 112 days of incubation at moderate (near field capacity) water content. Tomato seedlings were used for the P uptake test. The large set of data was used to evaluate the effect of each treatment on P reactions and mechanisms of retention in the tested soils and to correlate various P indices to P availability for plants. Plant P uptake was highly correlated to Olsen-P as well as to water-soluble inorganic-P, but not to water-soluble organic-P and not to total P or other experimentally-defined stable P fractions. We conclude that the P stabilization in the sludge will allow beneficial and sustainable use of sewage sludge as a soil amendment and source of nutrients, but the stabilization method should be selected in accordance with the target soil properties.

  17. 31P NMR saturation-transfer measurements in Saccharomyces cerevisiae: characterization of phosphate exchange reactions by iodoacetate and antimycin A inhibition

    International Nuclear Information System (INIS)

    Campbell-Burk, S.L.; Jones, K.A.; Shulman, R.G.

    1987-01-01

    31 P nuclear magnetic resonance (NMR) saturation-transfer (ST) techniques have been used to measure steady-state flows through phosphate-adenosine 5'-triphosphate (ATP) exchange reactions in glucose-grown derepressed yeast. The results have revealed that the reactions catalyzed by glyceraldehyde-3-phosphate dehydrogenase/phosphoglycerate kinase (GAPDH/PGK) and by the mitochondrial ATPase contribute to the observed ST. Contributions from these reactions were evaluated by performing ST studies under various metabolic conditions in the presence and absence of either iodoacetate, a specific inhibitor of GAPDH, or the respiratory chain inhibitor antimycin A. Intracellular phosphate (P/sub i/) longitudinal relaxation times were determined by performing inversion recovery experiments during steady-state ATP/sub λ/ saturation and were used in combination with ST data to determine P/sub i/ consumption rates. 13 C NMR and O 2 electrode measurements were also conducted to monitor changes in rates of glucose consumption and O 2 consumption, respectively, under the various metabolic conditions examined. The results suggest that GAPDH/PGK-catalyzed P/sub i/-ATP exchange is responsible for antimycin-resistant saturation transfer observed in anaerobic and aerobic glucose-fed yeast. Kinetics through GAPDH/PGK were found to depend on metabolic conditions. The coupled system appears to operate in a unidirectional manner during anaerobic glucose metabolism and bidirectionally when the cells are respiring on exogenously supplied ethanol. Additionally, mitochondrial ATPase activity appears to be responsible for the transfer observed in iodoacetate-treated aerobic cells supplied with either glucose or ethanol, with synthesis of ATP occurring unidirectionally

  18. Measurement of the 13C(α,n)16O reaction with the Trojan horse method: Focus on the sub threshold resonance at −3 keV

    International Nuclear Information System (INIS)

    La Cognata, M.; Spitaleri, C.; Guardo, G. L.; Puglia, S. M. R.; Romano, S.; Spartà, R.; Trippella, O.; Kiss, G. G.; Rogachev, G. V.; Avila, M.; Koshchiy, E.; Kuchera, A.; Santiago, D.; Mukhamedzhanov, A. M.; Lamia, L.

    2014-01-01

    The 13 C(α,n) 16 O reaction is the neutron source of the main component of the s-process. The astrophysical S(E)-factor is dominated by the −3 keV sub-threshold resonance due to the 6.356 MeV level in 17 O. Its contribution is still controversial as extrapolations, e.g., through R-matrix calculations, and indirect techniques, such as the asymptotic normalization coefficient (ANC), yield inconsistent results. Therefore, we have applied the Trojan Horse Method (THM) to the 13 C( 6 Li,n 16 O)d reaction to measure its contribution. For the first time, the ANC for the 6.356 MeV level has been deduced through the THM, allowing to attain an unprecedented accuracy. Though a larger ANC for the 6.356 MeV level is measured, our experimental S(E) factor agrees with the most recent extrapolation in the literature in the 140-230 keV energy interval, the accuracy being greatly enhanced thanks to this innovative approach, merging together two well establish indirect techniques, namely, the THM and the ANC

  19. A new approach to measure reaction parameters in the 14.8 meV neutron induced fission of 240Pu and 241Pu

    Science.gov (United States)

    Khan, Naeem A.; Khan, Hameed A.; Gul, Khunab; Akber, Riaz A.; Anwar, Muhammad; Waheed, Abdul; Hussain, Gulzar; Shaikh, M. Saleem

    1980-06-01

    A new approach has been made to use solid state nuclear track detectors in 2π-geometry for studying (a) the fission cross-section, and (b) the angular anisotropy of the fission fragments emitted in the 14.8 MeV neutron induced fission of 240Pu and 241Pu. The results of 2π-geometry arrangements have been compared with those obtained by using the conventional vacuum chamber measurements. The results indicate that with proper adjustments, the 2π-geometry method can cut down the accelerator time by at least a few orders of magnitude as compared to that required by the conventional vacuum chamber arrangements. This facilitates the studies of reactions with two yields. The paper also describes the measurements carried out to determine the spontaneous fission decay constants of the above mentioned isotopes of plutonium. Some preliminary values of other fission parameters have also been quoted.

  20. Measurement of activation reaction rate distribution on a mercury target with a lead-reflector and light-water-moderator for high energy proton bombardment using AGS accelerator

    International Nuclear Information System (INIS)

    Kasugai, Yoshimi; Takada, Hiroshi; Meigo, Shin-ichiro

    2001-02-01

    Characteristic of spallation neutrons driven by GeV protons from a mercury target with a lead-reflector and light-water-moderator was studied experimentally using the Alternating Gradient Synchrotron (AGS) facility of Brookhaven National Laboratory in a framework of the ASTE (AGS Spallation Target Experiment) collaboration. Several reaction rates along with the mercury target were measured with the activation method at incident proton energies of 1.94, 12 and 24 GeV. Indium, niobium, aluminum, cobalt, nickel and bismuth were used as activation detectors to cover the threshold energy of between 0.33 and 40.9 MeV. This report summarizes the experimental procedure with all the measured data. (author)

  1. Measurement of excitation functions and isomeric ratios of the reactions 103Rh(3He, xn) sup(106-x)Ag where x=2, 3 and 4

    International Nuclear Information System (INIS)

    Borges, A.M.

    1981-01-01

    The excitation functions and isomer ratios for the reactions 103 Rh( 3 He, xn) sup(106-x)Ag, where x=2, 3 and 4, were measured with projectile Lab energy varying from 23 to 35 MeV. Since the half-life of sup(103m)Ag is equal to 5.7 s. the use of a recoil nucleous gas jet transport system became necessary. The values measured for the cross-sections were compared to those yielded by the ALICE code. The experimental isomer ratios are smaller than those calculated using the residual nucleus spin distribution obtained with the ALICE code. By-pass fractions as expected in this mass region were also obtained. (Author) [pt

  2. Recoil measurement of the 12C(π(,πN))11C reaction between 90 and 350 MeV

    International Nuclear Information System (INIS)

    Porile, N.T.; Caretto, A.A.; Dropesky, B.J.; Orth, C.J.; Liu, L.C.; Giesler, G.C.

    1984-01-01

    The effective forward, perpendicular, and backward ranges of 11 C produced in the interaction of 90--350 MeV π +- with carbon have been measured using conventional thick-target thick-catcher activation techniques. With increasing pion energy, the forward ranges decrease, the backward ranges increase, and the perpendicular ranges remain essentially unchanged. However, these trends are much more pronounced for π - than for π + . The results have been compared with an intranuclear cascade code. The ratios of calculated effective ranges for π - and π + bombardment show the same energy dependence as observed experimentally

  3. Scanning Tunneling Microscopy Measurements of the Full Cycle of a Heterogeneous Asymmetric Hydrogenation Reaction on Chirally Modified Pt(111)

    DEFF Research Database (Denmark)

    Demers-Carpentier, Vincent; Goubert, Guillaume; Masini, Federico

    2012-01-01

    The hydrogenation of a prochiral substrate, 2,2,2-trifluoroacetophenone (TFAP), on Pt(111) was studied using room-temperature scanning tunneling microscopy (STM) measurements. The experiments were carried out both on a clean surface and on a chirally modified surface, using chemisorbed (R)-(+)-1...... protrusion compared to TFAP in dimer structures. They are attributed to a half-hydrogenated intermediate. The introduction of H2 to a mixture of (R)-NEA and TFAP on Pt(111) leads to the removal of TFAP without any change in the population of the modifier, as required for an efficient chirally modified...

  4. Fusion barrier distributions from capture and quasi-elastic excitation functions measured in reaction 36S, 48Ca, 64Ni+238U

    International Nuclear Information System (INIS)

    Kozulin, E. M.

    2009-01-01

    The subbarrier fusion enhancement in reactions with heavy ions were explained by taking into account coupling between relative motion and intrinsic degrees of freedom of interacting nuclei. The coupling of reaction channels manifests itself in the potential barrier between interacting nuclei giving rise to a distribution of fusion barrier instead of single barrier.Capture and quasi-elastic scattering excitation functions at backward angles were measured for 3 6S , 4 8C a, 6 4N i+2 38U reactions systems at energies close and below the Coulomb barrier (i.e. when the influence of the shell effects on the fusion and characteristics of the decay of the composite system is considerable). Representations of the barrier distributions were extracted from both capture and quasi-elastic data. The experimental representations of barrier distributions were compared with coupled-channel calculations using CCFULL code. The major part of these experiments has been performed at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR, Dubna); at the TANDEM-ALPI accelerator of the LNL (INFN, Legnaro, Italy) and at the Accelerator Laboratory of University of Jyvaeskylae (JYFL, Finland) using a time-of-flight spectrometer of fission fragments CORSET (CORrelation SET-up.) The extraction of the masses and Total Kinetic Energy (TKE) of the binary reaction products is based upon the analysis of the two-body velocity In the case of the fusion-fission and quasi-fission processes, the observed peculiarities of mass and energy distributions of the fragments, the ratio between the fusion-fission and quasi-fission cross sections are determined deformations of interaction nuclei and angular momentum carried in the di-nuclear system and the shell structure of the formed fragments. In this work, the high-precision capture and quasi-elastic scattering excitation function data are presented.The influence of projectile and target excitations and nucleon transfer on fusion barrier

  5. Measurements of photo-oxidation products from the reaction of a series of alkyl-benzenes with hydroxyl radicals during EXACT using comprehensive gas chromatography

    Directory of Open Access Journals (Sweden)

    J. F. Hamilton

    2003-01-01

    Full Text Available Photo-oxidation products from the reaction of a series of alkyl-benzenes, (benzene, toluene, p-xylene and 1,3,5-trimethyl-benzene with hydroxyl radicals in the presence of NOx have been investigated using comprehensive gas chromatography (GCxGC. A GCxGC system has been developed which utilises valve modulation and independent separations as a function of both volatility and polarity. A number of carbonyl-type compounds were identified during a series of reactions carried out at the European Photoreactor (EUPHORE, a large volume outdoor reaction chamber in Valencia, Spain. Experiments were carried as part of the EXACT project (Effects of the oXidation of Aromatic Compounds in the Troposphere. Two litre chamber air samples were cryo-focused, with a sampling frequency of 30 minutes, allowing the evolution of species to be followed over oxidation periods of 3-6 hours. To facilitate product identification, several carbonyl compounds, which were possible products of the photo-oxidation, were synthesised and used as reference standards. For toluene reactions, observed oxygenated intermediates found included the co-eluting pair a-angelicalactone/4-oxo-2-pentenal, maleic anhydride, citraconic anhydride, benzaldehyde and p-methyl benzoquinone. In the p-xylene experiment, the products identified were E/Z-hex-3-en-2,5-dione and citraconic anhydride. For 1,3,5-TMB reactions, the products identified were 3,5-dimethylbenzaldehyde, 3,5-dimethyl-3H-furan-2-one and 3-methyl-5-methylene-5H-furan-2-one. Preliminary quantification was carried out on identified compounds using liquid standards. Comparison of FTIR and GCxGC for the measurement of the parent aromatics generally showed good agreement. Comparison of the concentrations observed by GCxGC to concentration-time profiles simulated using the Master Chemical Mechanism, MCMv3, demonstrates that this mechanism significantly over-predicts the concentrations of many product compounds and highlights the

  6. Measurements of photo-oxidation products from the reaction of a series of alkyl-benzenes with hydroxyl radicals during EXACT using comprehensive gas chromatography

    Science.gov (United States)

    Hamilton, J. F.; Lewis, A. C.; Bloss, C.; Wagner, V.; Henderson, A. P.; Golding, B. T.; Wirtz, K.; Martin-Reviejo, M.; Pilling, M. J.

    2003-11-01

    Photo-oxidation products from the reaction of a series of alkyl-benzenes, (benzene, toluene, p-xylene and 1,3,5-trimethyl-benzene) with hydroxyl radicals in the presence of NOx have been investigated using comprehensive gas chromatography (GCxGC). A GCxGC system has been developed which utilises valve modulation and independent separations as a function of both volatility and polarity. A number of carbonyl-type compounds were identified during a series of reactions carried out at the European Photoreactor (EUPHORE), a large volume outdoor reaction chamber in Valencia, Spain. Experiments were carried as part of the EXACT project (Effects of the oXidation of Aromatic Compounds in the Troposphere). Two litre chamber air samples were cryo-focused, with a sampling frequency of 30 minutes, allowing the evolution of species to be followed over oxidation periods of 3-6 hours. To facilitate product identification, several carbonyl compounds, which were possible products of the photo-oxidation, were synthesised and used as reference standards. For toluene reactions, observed oxygenated intermediates found included the co-eluting pair a-angelicalactone/4-oxo-2-pentenal, maleic anhydride, citraconic anhydride, benzaldehyde and p-methyl benzoquinone. In the p-xylene experiment, the products identified were E/Z-hex-3-en-2,5-dione and citraconic anhydride. For 1,3,5-TMB reactions, the products identified were 3,5-dimethylbenzaldehyde, 3,5-dimethyl-3H-furan-2-one and 3-methyl-5-methylene-5H-furan-2-one. Preliminary quantification was carried out on identified compounds using liquid standards. Comparison of FTIR and GCxGC for the measurement of the parent aromatics generally showed good agreement. Comparison of the concentrations observed by GCxGC to concentration-time profiles simulated using the Master Chemical Mechanism, MCMv3, demonstrates that this mechanism significantly over-predicts the concentrations of many product compounds and highlights the uncertainties which exist in

  7. Analysis of the accuracy of absolute measurements of high d.c. voltages by means of (p,γ)-compound-nucleus reactions

    International Nuclear Information System (INIS)

    Weissmueller, G.

    1987-01-01

    Absolute measurement of high d.c. voltages by means of (p,γ)-compound nucleus-reactions is based on the determination of the kinetic energy of charged particles which are accelerated in the electrostatic field of the high voltage to be measured. The particle energy is equivalent to the product of beam potential and particle charge and thus affords a simple means of inverse calculation of high d.c. voltages. On the basis of the physics of compound-nucleus reactions and the analysis of various natural and plant-specific, potential causes of error, special demands are to be made on the electrostatic acceleration device used to carry through the (p,γ)-nuclear resonance process, which were taken into account in the planning and technical realization of the extensive test device. The discussion of target properties entailing impaired accuracy led to the presentation of a fork process using staggered targets. By that process a close energy interval can be established which is sure to encompass the locus of the natural resonance energy. The conditions governing this process for the location of nuclear resonance are easily verifiable by measurements, independently of the magnitude of plant-dependent factors of error; it is a process yielding accuracies in the range of tenths per mil supposing an optimum test device. Contrary to resistance measuring bridges, the fork process in combination with the electrostatic 800-keV proton accelerator permits calibration of high-ohmic resistors and voltage dividers for rated voltages of up to 800 kV, taking into account possible non-linearity effects. (orig.) With 66 figs., 4 tabs [de

  8. Placental complications after a previous cesarean section

    OpenAIRE

    Milošević Jelena; Lilić Vekoslav; Tasić Marija; Radović-Janošević Dragana; Stefanović Milan; Antić Vladimir

    2009-01-01

    Introduction The incidence of cesarean section has been rising in the past 50 years. With the increased number of cesarean sections, the number of pregnancies with the previous cesarean section rises as well. The aim of this study was to establish the influence of the previous cesarean section on the development of placental complications: placenta previa, placental abruption and placenta accreta, as well as to determine the influence of the number of previous cesarean sections on the complic...

  9. New prompt fission neutron spectra measurements in the 238U(n,f reaction with a dedicated setup at LANSCE/WNR

    Directory of Open Access Journals (Sweden)

    Laurent Benoit

    2017-01-01

    Full Text Available A new prompt fission neutron spectra (PFNS measurement in the 238U(n,f reaction was performed at LANSCE/WNR facility. Evaluated data show discrepancies on the low (below 1 MeV and high (above 5 MeV energy parts in the PFNS for different major and minor actinides. The goal is to improve these measurements in a wide range of incident energy. The energy of the incoming neutron, inducing the fission, and the prompt neutron energies, are measured by time-of-flight method. A dedicated fission chamber was developed, in order to improve alpha-fission discrimination, timing resolution, actinide mass, and to reduce the amount of neutron scattering. To detect prompt neutrons, the 54 Chi-Nu scintillator cells array were surrounding the fission chamber. High statistics were recorded during this experiment, allowing a precise study of PFNS behavior as a function of incident neutron energy, from 1 MeV to 200 MeV. This experiment also showed that all the new tools developed to improve PFNS measurements are performing. Therefore, measurements of PFNS with others actinides such as 239Pu are planned.

  10. Research Note Effects of previous cultivation on regeneration of ...

    African Journals Online (AJOL)

    Research Note Effects of previous cultivation on regeneration of Julbernadia globiflora and Brachystegia spiciformis in grazing areas of Mupfurudzi ... Plant attributes for Julbernadia globiflora and Brachystegia spiciformis were measured in previously cultivated and uncultivated sites making up rangelands of the scheme.

  11. Direct cross section measurement for the 18O(p,γ)19F reaction at astrophysical energies at LUNA

    Science.gov (United States)

    Pantaleo, F. R.; Best, A.; Imbriani, G.; Perrino, R.

    2018-01-01

    18O(p, γ)19F plays an important role in the AGB star scenarios. The low energy cross section could be influenced by a hypothetical low energy resonance at 95 keV and by the tails of the higher energy broad states. The 95 keV resonance lies in the energy window corresponding to the relevant stellar temperature range of 40-50 MK. Measurements of the direct cross section were performed at the Laboratory for Underground Nuclear Astrophysics (LUNA), including the unobserved low energy resonance, the higher energy resonances and the non-resonant component, taking advantage of the extremely low environmental background. Here we report on the experimental setup and the status of the analysis.

  12. Activation method for measuring the reaction rates and studying the neutron spectra parameters, based on using the unified composition detectors

    International Nuclear Information System (INIS)

    Demidov, A.M.; Dikarev, V.S.; Efimov, B.V.; Ionov, V.S.; Marin, S.V.

    2005-01-01

    The method proposed for estimation of parameters thermal and epithermal parts of energy distribution of neutrons is described. The method based on application of activation measuring with use of unified composition detectors (UCD) and samples of fuel. The method is applicable for definition of neutron spectrum parameters and velocities of division in fuel of nuclear installations. Theoretical bases and the description of a method, expedients of manufacturing and calibration for the detectors, the experimental data, carried out in RRC KI are given and processing of experimental data, and also. The parametric model of a spectrum constructed on the basis of Westcott's formalism is described. The parameter of stiffness is entered and its role for temperature of neutron gas, spectral coefficients of isotopes of detectors, the transition area thermal and epithermal parts of neutron spectra is observationally appreciated. It is offered to confirm the found results by calculations with use of MCU Monte Carlo code [ru

  13. Addressing fear of crime in public space: gender differences in reaction to safety measures in train transit.

    Science.gov (United States)

    Yavuz, Nilay; Welch, Eric W

    2010-01-01

    Research has identified several factors that affect fear of crime in public space. However, the extent to which gender moderates the effectiveness of fear-reducing measures has received little attention. Using data from the Chicago Transit Authority Customer Satisfaction Survey of 2003, this study aims to understand whether train transit security practices and service attributes affect men and women differently. Findings indicate that, while the presence of video cameras has a lower effect on women's feelings of safety compared with men, frequent and on-time service matters more to male passengers. Additionally, experience with safety-related problems affects women significantly more than men. Conclusions discuss the implications of the study for theory and gender-specific policies to improve perceptions of transit safety.

  14. High-Resolution Measurement of the {sup 4}He({gamma},n) Reaction in the Giant Resonance Region

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Bjoern

    2003-03-01

    A comprehensive near-threshold {sup 4}He(gamma,n) absolute cross section measurement has been performed at the high-resolution tagged-photon facility MAX-lab located in Lund, Sweden. The 20 < Eg < 45 MeV tagged photons (covering the Giant Dipole Resonance energy region) were directed towards a liquid {sup 4}He target, and knocked-out neutrons were detected in a pair of 60 cm x 60 cm vetoed NE213A liquid scintillator arrays. The intense and varying charge-neutral experimental backgrounds were carefully quantified and removed from the data using a precision fitting procedure. Eight average laboratory angles (30, 45, 60, 75, 90, 105, 120, and 135 deg) were investigated for eight photon energy bins (25, 27, 29, 31, 35, 36, 39, and 41 MeV), resulting in 64 differential cross sections. These angular distributions were integrated to produce total cross sections as a function of photon energy. The resulting cross sections peak at 1.9 mb at a photon energy of 27 MeV, and fall off to a near-constant value of 1.1 mb by 36 MeV. Further, they are in excellent agreement with those measured by Sims et al. using tagged photons in the Quasi-Deuteron energy region. Overall, the results favor modern theoretical models which are based upon a charge-symmetric nucleon-nucleon force, in marked contrast to the recommendations made by Calarco et al. in 1983 based on the sparse {sup 4}He(gamma,n) data available at the time.

  15. Post-marketing surveillance of the safety profile of iodixanol in the outpatient CT setting. A prospective, multicenter, observational study of patient risk factors, adverse reactions and preventive measures in 9953 patients

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Frank Hugo Heinz [Radiology and Nuclear Medicine Center, Ludwigshafen (Germany)

    2014-11-15

    Non-interventional study in outpatient, contrast-enhanced CT: 1. to determine the extent of preventive measures for risk reduction of adverse drug reactions after contrast-enhanced CT examinations. 2. to prospectively determine the incidence and severity of adverse drug reactions occurring after administration of the iso-osmolar contrast medium iodixanol. 3. to determine a possible influence of preventive measures on the incidence/severity of adverse drug reactions. Evaluable documentation was provided for 9953 patients from 66 radiology centers across Germany. Patient characteristics, aspects of iodixanol administration, and adverse events with an at least 'possible' relationship were documented on a standardized case report form (CRF) and were evaluated up to seven days after contrast medium administration. About 55.5% of patients showed one or more risk factors (e.g. impaired renal function 4.4%, diabetes mellitus 8.5%, hypertension 20.6%). One third of the sites did not implement any preventive measures. Patients with a known risk for an allergy-like reaction were more likely to receive pharmacologic preventive treatment (0.5-50.5%). Oral hydration was the main preventive measure in patients with renal risk factors (<8%) followed by intravenous hydration (1%). Adverse drug reactions, mainly hypersensitivity reactions, occurred in 77 patients (0.74%), but were classified as serious in only 3 patients (0.03%). No statistically significant correlation between risk factors, preventive measures, and adverse reactions could be found. The use of preventive measures for CT examinations in this outpatient setting was generally low with risk patients being pre-medicated more often, depending on their history. In the routine outpatient setting, iso-osmolar iodixanol was very well tolerated in almost 10 000 patients undergoing diagnostic CT. The rate of acute and delayed adverse reactions was low. No correlation could be found between risk factors, preventive

  16. Nuclear reaction studies

    International Nuclear Information System (INIS)

    Alexander, J.M.; Lacey, R.A.

    1994-01-01

    Research focused on the statistical and dynamical properties of ''hot'' nuclei formed in symmetric heavy-ion reactions. Theses included ''flow'' measurements and the mechanism for multifragment disassembly. Model calculations are being performed for the reactions C+C, Ne+Al, Ar+Sc, Kr+Nb, and Xe+La. It is planned to study 40 Ar reactions from 27 to 115 MeV/nucleon. 2 figs., 41 refs

  17. Reaction rate reconstruction from biomass concentration measurement in bioreactors using modified second-order sliding mode algorithms.

    Science.gov (United States)

    De Battista, Hernán; Picó, Jesús; Garelli, Fabricio; Navarro, José Luis

    2012-11-01

    This paper deals with the estimation of unknown signals in bioreactors using sliding observers. Particular attention is drawn to estimate the specific growth rate of microorganisms from measurement of biomass concentration. In a recent article, notions of high-order sliding modes have been used to derive a growth rate observer for batch processes. In this paper we generalize and refine these preliminary results. We develop a new observer with a different error structure to cope with other types of processes. Furthermore, we show that these observers are equivalent, under coordinate transformations and time scaling, to the classical super-twisting differentiator algorithm, thus inheriting all its distinctive features. The new observers' family achieves convergence to time-varying unknown signals in finite time, and presents the best attainable estimation error order in the presence of noise. In addition, the observers are robust to modeling and parameter uncertainties since they are based on minimal assumptions on bioprocess dynamics. In addition, they have interesting applications in fault detection and monitoring. The observers performance in batch, fed-batch and continuous bioreactors is assessed by experimental data obtained from the fermentation of Saccharomyces Cerevisiae on glucose.

  18. Exclusive measurement of breakup reactions with the one-neutron halo nucleus sup 1 sup 1 Be

    CERN Document Server

    Palit, R; Aumann, T; Boretzky, K; Carlson, B V; Cortina-Gil, D; Elze, T W; Emling, H; Geissel, H; Hellström, M; Jones, K L; Kratz, J V; Kulessa, R; Leifels, Y; Leistenschneider, A; Münzenberg, G; Nociforo, C; Reiter, P; Simon, H; Sümmerer, K; Walús, W

    2003-01-01

    Electromagnetic and nuclear inelastic scattering of the halo nucleus sup 1 sup 1 Be have been investigated by a measurement of the one-neutron removal channel, utilizing a secondary sup 1 sup 1 Be beam with an energy of 520 MeV/nucleon impinging on lead and carbon targets. All decay products, i.e. sup 1 sup 0 Be fragments, neutrons, and gamma-rays have been detected in coincidence. Partial cross sections for the population of ground and excited states in sup 1 sup 0 Be were determined for nuclear diffractive breakup as well as for electromagnetically induced breakup. The partial cross sections for ground-state transitions have been differentiated further with respect to excitation energy, and the dipole-strength function associated solely with transitions of the halo 2s sub 1 sub / sub 2 neutron to the continuum has been derived. The extracted dipole strength integrated from the neutron threshold up to 6.1 MeV excitation energy amounts to 0.90(6) e sup 2 fm sup 2. A spectroscopic factor for the nu 2s sub 1 su...

  19. Anaphylactic reaction to orthoiodohippurate

    Energy Technology Data Exchange (ETDEWEB)

    Stoeckel, M.; Roedbro, P.; Ennow, K.; Kristensen, K.

    1983-02-01

    A case of an anaphylactic reaction following administration of /sup 125/I- and /sup 131/-I-o-iodohippurate in a 32-year-old woman is reported. The patient had a renography performed because of hematuria. She was known to react to an intravenous pyelography previously performed with an anaphylactic shock. The importance of reporting all adverse reactions to radiopharmaceuticals for central registration is stressed.

  20. Measurement of the Target-Normal Single-Spin Asymmetry in Deep-Inelastic Scattering from the Reaction 3He{uparrow}(e,e')X

    Energy Technology Data Exchange (ETDEWEB)

    Katich, Joseph; Qian, Xin; Zhao, Yuxiang; Allada, Kalyan; Aniol, Konrad; Annand, John; Averett, Todd; Benmokhtar, Fatiha; Bertozzi, William; Bradshaw, Elliott; Bosted, Peter; Camsonne, Alexandre; Canan, Mustafa; Cates, Gordon; Chen, Chunhua; Chen, Jian-Ping; Chen, Wei; Chirapatpimol, Khem; Chudakov, Eugene; Cisbani, Evaristo; Cornejo, Juan; Cusanno, Francesco; Dalton, Mark; Deconinck, Wouter; De Jager, Cornelis; De Leo, Raffaele; Deng, Xiaoyan; Deur, Alexandre; Ding, Huaibo; Dolph, Peter; Dutta, Chiranjib; Dutta, Dipangkar; El Fassi, Lamiaa; Frullani, Salvatore; Gao, Haiyan; Garibaldi, Franco; Gaskell, David; Gilad, Gilad; Gilman, Ronald; Glamazdin, Oleksandr; Golge, Serkan; Guo, Lei; Hamilton, David; Hansen, Jens-Ole; Higinbotham, Douglas; Holmstrom, Timothy; Huang, Jijun; Huang, Min; Ibrahim Abdalla, Hassan; Iodice, Mauro; Jin, Ge; Jones, Mark; Kelleher, Aidan; Kim, Wooyoung; Kolarkar, Ameya; Korsch, Wolfgang; LeRose, John; Li, Xiaomei; Li, Y; Lindgren, Richard; Liyanage, Nilanga; Long, Elena; Lu, Hai-jiang; Margaziotis, Demetrius; Markowitz, Pete; Marrone, Stefano; McNulty, Dustin; Meziani, Zein-Eddine; Michaels, Robert; Moffit, Bryan; Munoz Camacho, Carlos; Nanda, Sirish; Narayan, Amrendra; Nelyubin, Vladimir; Norum, Blaine; Oh, Yoomin; Osipenko, Mikhail; Parno, Diana; Peng, Jen-chieh; Phillips, Sarah; Posik, Matthew; Puckett, Andrew; Qiang, Yi; Rakhman, Abdurahim; Ransome, Ronald; Riordan, Seamus; Saha, Arunava; Sawatzky, Bradley; Schulte, Elaine; Shahinyan, Albert; Hashemi Shabestari, Mitra; Sirca, Simon; Stepanyan, Stepan; Subedi, Ramesh; Sulkosky, Vincent; Tang, Liguang; Tobias, William; Urciuoli, Guido; Vilardi, Ignazio; Wang, Kebin; Wang, Y; Wojtsekhowski, Bogdan; Yan, X; Yao, Huan; Ye, Yunxiu; Ye, Z; Yuan, Lulin; Zhan, Xiaohui; Zhang, Yi; Zhang, Y -W; Zhao, Bo; Zheng, Xiaochao; Zhu, Lingyan; Zhu, Xiaofeng; Zong, Xing

    2014-07-01

    We report the first measurement of the target single-spin asymmetry in deep-inelastic scattering from the inclusive reaction 3He{uparrow}(e,e')X on a 3He gas target polarized normal to the lepton plane. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of 1.7measured proton-to-3He cross section ratios. The measured neutron asymmetries are negative with an average value of (−1.04+/-0.38)×10−2 for invariant mass W>2 GeV, which is non-zero at the 2.75sigma level. Theoretical calculations, which assume two-photon exchange with quasi-free quarks, predict a neutron asymmetry of O(10−4) when both photons couple to one quark, and O(10−2) for the photons coupling to different quarks. Our measured asymmetry agrees both in sign and magnitude with the prediction that uses input based on the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering.

  1. Nuclear reactions

    International Nuclear Information System (INIS)

    Lane, A.M.

    1980-01-01

    In reviewing work at Harwell over the past 25 years on nuclear reactions it is stated that a balance has to be struck in both experiment and theory between work on cross-sections of direct practical relevance to reactors and on those relevant to an overall understanding of reaction processes. The compound nucleus and direct process reactions are described. Having listed the contributions from AERE, Harwell to developments in nuclear reaction research in the period, work on the optical model, neutron capture theory, reactions at doorway states with fine structure, and sum-rules for spectroscopic factors are considered in more detail. (UK)

  2. Measurement of the total reaction cross section for interactions between heavy ions (application to the system 12C+12C at 112MeV)

    International Nuclear Information System (INIS)

    Cherkaoui-Tadili, R.

    1982-01-01

    The total reaction cross-section σsub(R) for interactions between heavy ions is predicted to decrease rapidly with the energy of the incident projectile over the energy range 10 MeV/A - 100 MeV/A. We present here an experimental met σsub(R) to test the model based predictions. The method consists in counting the number of all incoming projectiles and the number of out going projectiles that did not interact with the target. The difference between these two numbers corresponds to the number of particles that reacted with the target nuclei and is therefore proportional to σsub(R). Values of σsub(R) have been measured for the system 12 C + 12 C at two incident energies of 112 MeV and 996 MeV. The results of 1444 +- 70 (112 MeV) and 994 +- 50 (996 MeV) show a total reaction cross-section decreasing with energy as predicted from the Glauber model and optical model fits to elastic scattering [fr

  3. Measurement of cross-sections for produced radionuclide in proton induced reactions on {sup nat}Hf up to 45 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Shahid, Muhammad; Kim, Kwangsoo [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Naik, Haladhara [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Kim, Guinyun, E-mail: gnkim@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of)

    2014-03-01

    We measured production cross-sections of Hf, Lu, and Ta radioisotopes from proton-induced reaction of {sup nat}Hf by using a stacked-foil activation and off-line γ-ray spectrometric technique at the MC-50 cyclotron of the Korea Institute of Radiological and Medical Sciences. The results were compared with the reported experimental data as well as the theoretical calculations based on the TALYS 1.4 code. The present results in the energy region from the threshold energy to 45 MeV are in general good agreement with the other experimental data and calculated results. The present experimental results will play an important role in enrichment of the literature data base for proton-induced reactions on natural hafnium leading to various applications. Some of the investigated radionuclides (e.g. {sup 177g}Lu) have remarkable applications in the field of nuclear medicine, a thin layer activation analysis, and a trace element analysis.

  4. Measurement of total reaction sup 4 sup , sup 6 He + sup 2 sup 8 Si cross section at 10-28 MeV/A

    CERN Document Server

    Kuznetsov, I V; Kalpakchieva, R

    2002-01-01

    New results have been obtained for the energy dependence of the total reaction cross section sigma sub R of sup 6 He on sup 2 sup 8 Si in the energy range 10-28 MeV/A. The cross sections of formation of alpha-particles in the interaction of sup 2 sup 8 Si( sup 6 He + sup 4 He)X were also measured. The secondary sup 6 He beams, with an intensity of up to 5 x 10 sup 4 pps, were produced by bombarding a thick beryllium target with a primary sup 7 Li beam of approx 32 MeV/A. In the energy region below 17 MeV/A a strong rise in the values of sigma sub R has been observed. The experimental data on sigma sub R are compared with calculations, where for the analysis of sigma sub R the double-folding potential in the frame of the optical model is used. The different energy dependence of sigma sub R for sup 6 He compared to that of some neighbouring nuclei may be due to peculiarities in its structure. The energy spectra of the alpha-particles, produced in the sup 2 sup 8 Si( sup 6 He + sup 4 He) reaction, show that they...

  5. A proposed direct measurement of cross section at Gamow window for key reaction 19F(p,α) 16O in Asymptotic Giant Branch stars with a planned accelerator in CJPL

    Science.gov (United States)

    He, JianJun; Xu, ShiWei; Ma, ShaoBo; Hu, Jun; Zhang, LiYong; Fu, ChangBo; Zhang, NingTao; Lian, Gang; Su, Jun; Li, YunJu; Yan, ShengQuan; Shen, YangPing; Hou, SuQing; Jia, BaoLu; Zhang, Tao; Zhang, XiaoPeng; Guo, Bing; Kubono, Shigeru; Liu, WeiPing

    2016-05-01

    In 2014, the National Natural Science Foundation of China (NSFC) approved the Jinping Underground Nuclear Astrophysics laboratory (JUNA) project, which aims at direct cross-section measurements of four key stellar nuclear reactions right down to the Gamow windows. In order to solve the observed fluorine overabundances in Asymptotic Giant Branch (AGB) stars, measuring the key 19F(p,α)16O reaction at effective burning energies (i.e., at Gamow window) is established as one of the scientific research sub-projects. The present paper describes this sub-project in details, including motivation, status, experimental setup, yield and background estimation, aboveground test, as well as other relevant reactions.

  6. Preoperative screening: value of previous tests.

    Science.gov (United States)

    Macpherson, D S; Snow, R; Lofgren, R P

    1990-12-15

    To determine the frequency of tests done in the year before elective surgery that might substitute for preoperative screening tests and to determine the frequency of test results that change from a normal value to a value likely to alter perioperative management. Retrospective cohort analysis of computerized laboratory data (complete blood count, sodium, potassium, and creatinine levels, prothrombin time, and partial thromboplastin time). Urban tertiary care Veterans Affairs Hospital. Consecutive sample of 1109 patients who had elective surgery in 1988. At admission, 7549 preoperative tests were done, 47% of which duplicated tests performed in the previous year. Of 3096 previous results that were normal as defined by hospital reference range and done closest to the time of but before admission (median interval, 2 months), 13 (0.4%; 95% CI, 0.2% to 0.7%), repeat values were outside a range considered acceptable for surgery. Most of the abnormalities were predictable from the patient's history, and most were not noted in the medical record. Of 461 previous tests that were abnormal, 78 (17%; CI, 13% to 20%) repeat values at admission were outside a range considered acceptable for surgery (P less than 0.001, frequency of clinically important abnormalities of patients with normal previous results with those with abnormal previous results). Physicians evaluating patients preoperatively could safely substitute the previous test results analyzed in this study for preoperative screening tests if the previous tests are normal and no obvious indication for retesting is present.

  7. Measurement of polarization observables in the reaction {gamma}p{yields} p{pi}{sup 0}{pi}{sup 0} using linearly polarized photons with the CBELSA/TAPS experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sokhoyan, Vahe

    2012-07-27

    The spectrum and the properties of baryon resonances can be studied using photons with energies appropriate to excite baryonic states. Double meson photoproduction allows access to cascading resonance decays via other excited states. Also, at higher energies the importance of the double meson photoproduction increases due to higher cross-sections in comparison to single meson photoproduction. To study baryon resonances, the measurement of polarization observables as well as the measurement of differential cross-sections plays a very important role. In this work the three-body polarization observables I{sup s}, I{sup c} and the respective twobody asymmetry {Sigma} were measured for the reaction {gamma}p {yields} p{pi}{sup 0}{pi}{sup 0} in an incoming photon energy range of E{sub {gamma}} = 970 - 1650 MeV. The data were acquired with the CBELSA/TAPS experiment located at the ELSA accelerator in Bonn, using a linearly polarized photon beam impinging on a liquid hydrogen target. The observables I{sup s} and I{sup c} which occur in two-meson final states are measured for the first time in the reaction {gamma}p {yields} p{pi}{sup 0}{pi}{sup 0}. The corresponding two-body asymmetry {Sigma} is measured in an extended energy range in comparison to already existing data. A comparison with theoretical models shows that the polarization observables provide valuable input to study resonance contributions and their decay modes. The D{sub 33}(1700) {yields} {Delta}{pi} decay is studied based on the comparison of the Bonn-Gatchina Partial Wave Analysis (PWA) predictions with the data. Furthermore, a comparison of the data with the Bonn-Gatchina PWA and the Fix isobar model predictions allows to distinguish between these two models. Additionally, band-like structures and peaks are observed in the mass ranges of {Delta}(1232), D{sub 13}(1520), F{sub 15}(1680), f{sub 0}(980) and f{sub 2}(1270) in the according Dalitz plots and invariant mass distributions. The contributions of these

  8. Measurement of the spallation reaction {sup 56}Fe+p in inverse kinematics; Messung der Spallationsreaktion {sup 56}Fe+p in inverser Kinematik

    Energy Technology Data Exchange (ETDEWEB)

    Boehmer, M.

    2006-09-25

    In this work the spallation reaction {sup 56}Fe+p was investigated in inverse kinematics with regard to complete identification of the heavy residues. A ring imaging Cerenkov counter was used for velocity measurements in the experimental setup located at GSI in Darmstadt. A new fast readout electronic was developed and has been operated successfully in the experiment. Momentum reconstruction was carried out with the ALADiN spectrometer and a new software package written for this purpose. Cross sections and velocity distributions for more than 100 mass separated isotopes could be extracted from the dataset and compared with empirical models and other spallation experiments. The experiences gained in this experiment will be used for systematic improvements in the setup of the new spectrometer R3B at FAIR. (orig.)

  9. The application of inductively coupled plasma dynamic reaction cell mass spectrometry for measurement of selenium isotopes, isotope ratios and chromatographic detection of selenoamino acids

    DEFF Research Database (Denmark)

    Sloth, Jens Jørgen; Larsen, Erik Huusfeldt

    2000-01-01

    . A linear relationship (r mass from the Se-80 reference isotope. This indicated that the error was caused by mass bias. The slope of the curve at -3.0% error per mass unit can be used for correction of the measured......Inductively coupled plasma dynamic reaction cell mass spectrometry (ICP-DRC-MS) was characterised for the detection of the six naturally occurring selenium isotopes. The potentially interfering argon dimers at the selenium masses m/z 74, 76, 78 and 80 were reduced in intensity by approximately five...... ratios was close to the theoretical values for selenium concentrations at 1 and 10 ng ml(-1). The accuracy of the isotope ratios, however, was improved by correcting the count rate of all selenium isotopes equivalent to the formation of SeH at 9.6 +/- 0.5% one mass unit above the selenium isotopes...

  10. Measurement of the reaction e+e- → μ+μ- for 14 <= √S <= 36.4 GeV

    International Nuclear Information System (INIS)

    Behrend, H.J.; Chen, C.; Fenner, H.; Field, J.H.; Schroeder, V.; Sindt, H.; D'Agostini, G.; Apel, W.D.; Banerjee, S.; Bodenkamp, J.

    1982-03-01

    The reaction (e + e - → μ + μ - ) has been measured between √S = 14.0 GeV and √S = 36.4 GeV. The total cross section result is in good agreement with the QED prediction and the following Λ values have been obtained: Λsub(+) = 186 GeV, Λsub(-) = 101 GeV. The angular distribution at high energy ( = 34.2 GeV) shows a fitted charge asymmetry of -.064 +- .064 in agreement with the W-S model prediction of -0.092, corresponding to an axial coupling parameter a 2 = 4 g 2 sub(a) = 0.69 +- 0.69. (orig.)

  11. Automatic electromagnetic valve for previous vacuum

    International Nuclear Information System (INIS)

    Granados, C. E.; Martin, F.

    1959-01-01

    A valve which permits the maintenance of an installation vacuum when electric current fails is described. It also lets the air in the previous vacuum bomb to prevent the oil ascending in the vacuum tubes. (Author)

  12. Post-marketing surveillance of the safety profile of iodixanol in the outpatient CT setting: a prospective, multicenter, observational study of patient risk factors, adverse reactions and preventive measures in 9953 patients.

    Science.gov (United States)

    Müller, F H H

    2014-11-01

    Non-interventional study in outpatient, contrast-enhanced CT; 1. to determine the extent of preventive measures for risk reduction of adverse drug reactions after contrast-enhanced CT examinations. 2. to prospectively determine the incidence and severity of adverse drug reactions occurring after administration of the iso-osmolar contrast medium iodixanol. 3. to determine a possible influence of preventive measures on the incidence/severity of adverse drug reactions.. Evaluable documentation was provided for 9953 patients from 66 radiology centers across Germany. Patient characteristics, aspects of iodixanol administration, and adverse events with an at least "possible" relationship were documented on a standardized case report form (CRF) and were evaluated up to seven days after contrast medium administration. About 55.5 % of patients showed one or more risk factors (e. g. impaired renal function 4.4 %, diabetes mellitus 8.5 %, hypertension 20.6 %). One third of the sites did not implement any preventive measures. Patients with a known risk for an allergy-like reaction were more likely to receive pharmacologic preventive treatment (0.5 - 50.5 %). Oral hydration was the main preventive measure in patients with renal risk factors (Adverse drug reactions, mainly hypersensitivity reactions, occurred in 77 patients (0.74 %), but were classified as serious in only 3 patients (0.03 %). No statistically significant correlation between risk factors, preventive measures, and adverse reactions could be found. The use of preventive measures for CT examinations in this outpatient setting was generally low with risk patients being pre-medicated more often, depending on their history. In the routine outpatient setting, iso-osmolar iodixanol was very well tolerated in almost 10,000 patients undergoing diagnostic CT. The rate of acute and delayed adverse reactions was low. No correlation could be found between risk factors, preventive measures and the incidence

  13. Prevention of allergic reactions in anesthetized patients.

    Science.gov (United States)

    Caffarelli, C; Stringari, G; Miraglia Del Giudice, M; Crisafulli, G; Cardinale, F; Peroni, D G; Bernardini, R

    2011-01-01

    Hypersensitivity reactions during perioperative period are increasing and may be potentially life-threatening. Therefore, major emphasis is given to prevention. We perform a review to examine which measures should be taken to prevent reactions to products used in elective and emergency surgery. Any patient with a history of previous anaphylaxis or severe reaction during anaesthesia should be referred to allergist for detection of the offending compound. However, the identification of the triggering agent is not always feasible because of the low accuracy of diagnostic tests. In these cases and when emergency surgery is required, it should be considered to replace all drugs administered before the onset of the reaction with alternatives. Furthermore, any cross-reacting agent and latex, especially in patients belonging to populations at-risk for latex allergy should be avoided. In susceptible patients, premedication with antihistamines and corticosteroids might reduce the severity of reaction to drugs or contrast material while it is unclear whether pre-treatment decreases incidence of anaphylactic reactions. There is no evidence that premedication prevents allergic reactions to latex. Overall, physicians should not rely on the efficacy of premedication.

  14. The effects of acute and prolonged CRAM supplementation on reaction time and subjective measures of focus and alertness in healthy college students

    Directory of Open Access Journals (Sweden)

    Olson Mark

    2010-12-01

    Full Text Available Abstract Background The purpose of this study was to examine the effect of acute and prolonged (4-weeks ingestion of a supplement designed to improve reaction time and subjective measures of alertness, energy, fatigue, and focus compared to placebo. Methods Nineteen physically-active subjects (17 men and 2 women were randomly assigned to a group that either consumed a supplement (21.1 ± 0.6 years; body mass: 80.6 ± 9.4 kg or placebo (21.3 ± 0.8 years; body mass: 83.4 ± 18.5 kg. During the initial testing session (T1, subjects were provided 1.5 g of the supplement (CRAM; α-glycerophosphocholine, choline bitartrate, phosphatidylserine, vitamins B3, B6, and B12, folic acid, L-tyrosine, anhydrous caffeine, acetyl-L-carnitine, and naringin or a placebo (PL, and rested quietly for 10-minutes before completing a questionnaire on subjective feelings of energy, fatigue, alertness and focus (PRE. Subjects then performed a 4-minute quickness and reaction test followed by a 10-min bout of exhaustive exercise. The questionnaire and reaction testing sequence was then repeated (POST. Subjects reported back to the lab (T2 following 4-weeks of supplementation and repeated the testing sequence. Results Reaction time significantly declined (p = 0.050 between PRE and POST at T1 in subjects consuming PL, while subjects under CRAM supplementation were able to maintain (p = 0.114 their performance. Significant performance declines were seen in both groups from PRE to POST at T2. Elevations in fatigue were seen for CRAM at both T1 and T2 (p = 0.001 and p = 0.000, respectively, but only at T2 for PL (p = 0.029. Subjects in CRAM maintained focus between PRE and POST during both T1 and T2 trials (p = 0.152 and p = 0.082, respectively, whereas significant declines in focus were observed between PRE and POST in PL at both trials (p = 0.037 and p = 0.014, respectively. No difference in alertness was seen at T1 between PRE and POST for CRAM (p = 0.083, but a significant

  15. Development of a chemical kinetic measurement apparatus and the determination of the reaction rate constants for lithium-lead/water interaction

    International Nuclear Information System (INIS)

    Biney, P.O.

    1993-04-01

    An experimental set-up for accurate measurement of hydrogen generation rate in Lithium-Lead (Li 17 Pb 83 ) Steam or water interactions has been designed. The most important features of the design include a pneumatic actuated quick opening and closing high temperature all stainless steel valve used to control the reaction time and the placement of most measuring devices below a water line to minimize leakage of the hydrogen collected. A PC based data acquisition and control system provides remote process sequencing, acquisition and control of all major components of the set-up. Initial tests indicate that the first design objective of maintaining leakproof gas collection chamber has been achieved. Initial pressure tests indicated that the pressure drop over a time span of 30 minutes was within the tolerance of the pressure transducer used to measure the pressure (within 0.690 kPa) at a nominal system pressure of 685 kPa. The experimental system hardware, data acquisition and control programs and data analysis program have been completed, tested and are currently functional

  16. Improvements and important considerations for the 5-choice serial reaction time task-An effective measurement of visual attention in rats.

    Science.gov (United States)

    Bhandari, Jayant; Daya, Ritesh; Mishra, Ram K

    2016-09-01

    The 5-choice serial reaction time task (5-CSRTT) is an automated operant conditioning task that measures rodent attention. The task allows the measurement of several parameters such as response accuracy, speed of processing, motivation, and impulsivity. The task has been widely used to investigate attentional processes in rodents for attention deficit and hyperactivity disorder and has expanded to other illnesses such as Alzheimer's disease, depression, and schizophrenia. The 5-CSRTT is accompanied with two significant caveats: a time intensive training period and largely varied individual rat capability to learn and perform the task. Here we provide a regimented acquisition protocol to enhance training for the 5-CSRTT and discuss important considerations for researchers using the 5-CSRTT. We offer guidelines to ensure that inferences on performance in the 5-CSRTT are in fact a result of experimental manipulation rather than training differences, or individual animal capability. According to our findings only rats that have been trained successfully within a limited time frame should be used for the remainder of the study. Currently the 5-CSRTT employs a training period of variable duration and procedure, and its inferences on attention must overcome heterogeneous innate animal differences. The 5-CSRTT offers valuable and valid insights on various rodent attentional processes and their translation to the underpinnings of illnesses such as schizophrenia. The recommendations made here provide important criteria to ensure inferences made from this task are in fact relevant to the attentional processes being measured. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Highly segmented CVD diamond detectors and high-resolution momentum measurements in knockout reactions; Hochsegmentierte CVD Diamant Detektoren und hochaufloesende Impulsmessungen in Knockout Reaktionen

    Energy Technology Data Exchange (ETDEWEB)

    Schwertel, Sabine

    2009-11-26

    In recent years knockout reactions have proven to be important tools for investigations of the structure of light exotic nuclei. In spring 2006 an experiment was performed with the fragment separator at GSI in Darmstadt to extend this method to medium-mass nuclei with energies of about 400 AMeV. An experiment with a stable and well-known {sup 48}Ca primary beam was performed as a reference. The FRS was set for the reaction {sup 56}Ti{yields}{sup 55}Ti. Because of the high acceptance of the FRS, mother and daughter nuclei of one-neutron knockout reactions in the Sc isotopes {sup 51,52,53,54,55}Sc were also transported with high efficiency. These are investigated in the first part of this thesis. Inclusive cross sections of 77(10) mbarn for one-neutron knockout from {sup 48}Ca and 78(12) mbarn, 99(15) mbarn, 101(15) mbarn, 113(17) mbarn and 72(14) mbarn for knockout from {sup 51,52,53,54,55}Sc, respectively, were measured for the first time. For the Sc isotopes the reduction factors are close to 1. For the one-neutron knockout reactions in {sup 48}Ca and the Sc isotopes, respectively, the momentum distributions could be measured with a relative resolution of 0.17-0.27 %. From the momentum distributions spectroscopic factors of the involved orbitals could be extracted. In the future, further knockout experiments should be performed using the R{sup 3}B setup at FAIR. The available beam intensity will be up to four orders of magnitude higher. As the beam has to be tracked from the dispersive plane of the Super-FRS up to the R{sup 3}B target, radiation hard detectors are needed. In the framework of this thesis extensive measurements were performed at the tandem accelerator in Munich with numerous small (10 x 10 mm{sup 2}) test detectors. Samples using new manufacturing methods were characterized. A dose of some 10{sup 11} ions/mm{sup 2} was determined as a limit for the exposure of the material with heavy ions of high ionisation density. It could be shown that even

  18. Concomitant and previous osteoporotic vertebral fractures.

    Science.gov (United States)

    Lenski, Markus; Büser, Natalie; Scherer, Michael

    2017-04-01

    Background and purpose - Patients with osteoporosis who present with an acute onset of back pain often have multiple fractures on plain radiographs. Differentiation of an acute osteoporotic vertebral fracture (AOVF) from previous fractures is difficult. The aim of this study was to investigate the incidence of concomitant AOVFs and previous OVFs in patients with symptomatic AOVFs, and to identify risk factors for concomitant AOVFs. Patients and methods - This was a prospective epidemiological study based on the Registry of Pathological Osteoporotic Vertebral Fractures (REPAPORA) with 1,005 patients and 2,874 osteoporotic vertebral fractures, which has been running since February 1, 2006. Concomitant fractures are defined as at least 2 acute short-tau inversion recovery (STIR-) positive vertebral fractures that happen concomitantly. A previous fracture is a STIR-negative fracture at the time of initial diagnostics. Logistic regression was used to examine the influence of various variables on the incidence of concomitant fractures. Results - More than 99% of osteoporotic vertebral fractures occurred in the thoracic and lumbar spine. The incidence of concomitant fractures at the time of first patient contact was 26% and that of previous fractures was 60%. The odds ratio (OR) for concomitant fractures decreased with a higher number of previous fractures (OR =0.86; p = 0.03) and higher dual-energy X-ray absorptiometry T-score (OR =0.72; p = 0.003). Interpretation - Concomitant and previous osteoporotic vertebral fractures are common. Risk factors for concomitant fractures are a low T-score and a low number of previous vertebral fractures in cases of osteoporotic vertebral fracture. An MRI scan of the the complete thoracic and lumbar spine with STIR sequence reduces the risk of under-diagnosis and under-treatment.

  19. Uterine rupture without previous caesarean delivery

    DEFF Research Database (Denmark)

    Thisted, Dorthe L. A.; H. Mortensen, Laust; Krebs, Lone

    2015-01-01

    OBJECTIVE: To determine incidence and patient characteristics of women with uterine rupture during singleton births at term without a previous caesarean delivery. STUDY DESIGN: Population based cohort study. Women with term singleton birth, no record of previous caesarean delivery and planned...... vaginal delivery (n=611,803) were identified in the Danish Medical Birth Registry (1997-2008). Medical records from women recorded with uterine rupture during labour were reviewed to ascertain events of complete uterine rupture. Relative Risk (RR) and adjusted Relative Risk Ratio (aRR) of complete uterine...... rupture with 95% confidence intervals (95% CI) were ascertained according to characteristics of the women and of the delivery. RESULTS: We identified 20 cases with complete uterine rupture. The incidence of complete uterine rupture among women without previous caesarean delivery was about 3...

  20. Measurement of allergen-specific IgG in serum is of limited value for the management of dogs diagnosed with cutaneous adverse food reactions.

    Science.gov (United States)

    Hagen-Plantinga, E A; Leistra, M H G; Sinke, J D; Vroom, M W; Savelkoul, H F J; Hendriks, W H

    2017-02-01

    Conflicting results have been reported in the literature in terms of the usefulness of serological testing for IgG against food allergens in dogs with cutaneous adverse food reaction (CAFR). The aim of the present study was to evaluate the suitability of a commercially available IgG ELISA for identifying food allergens in dogs, by challenging dogs with specific food ingredients, selected on the basis of IgG reactivity in serum samples. A total of 24 adult dogs with CAFR were enrolled into the study and 16 healthy dogs were included as a control group. Blood samples were obtained for measurement of specific IgG antibodies against 39 commonly used pet food ingredients by ELISA. Participating owners were surveyed to obtain information on their pet's dietary history. Eleven healthy control dogs and 12 dogs with CAFR were subsequently challenged in a blinded cross-over design experiment with both positive and negative food ingredients, selected on the basis of the ELISA test results. There was substantial individual variation in ELISA test results to the various food allergens, but no significant difference in IgG reactivity comparing the CAFR and control groups. None of the control dogs developed any clinical signs of an allergic reaction during the dietary challenge study. In the CAFR group, six of 12 dogs developed clinical signs after the negative challenge, and two of nine dogs developed clinical signs after the positive challenge. It was concluded that the ELISA test for dietary allergen-specific IgG is of limited value in the management of dogs with CAFR. Copyright © 2017 Elsevier Ltd. All rights reserved.